WO1992002008A1 - Infrared touch screen device for a video monitor - Google Patents

Infrared touch screen device for a video monitor Download PDF

Info

Publication number
WO1992002008A1
WO1992002008A1 PCT/US1991/005158 US9105158W WO9202008A1 WO 1992002008 A1 WO1992002008 A1 WO 1992002008A1 US 9105158 W US9105158 W US 9105158W WO 9202008 A1 WO9202008 A1 WO 9202008A1
Authority
WO
WIPO (PCT)
Prior art keywords
bezel
emitters
sensors
infrared
monitor
Prior art date
Application number
PCT/US1991/005158
Other languages
French (fr)
Inventor
Mario Moreno
Original Assignee
Akzo, N.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Akzo, N.V. filed Critical Akzo, N.V.
Publication of WO1992002008A1 publication Critical patent/WO1992002008A1/en

Links

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/042—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means
    • G06F3/0421—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by opto-electronic means by interrupting or reflecting a light beam, e.g. optical touch-screen

Definitions

  • the present invention relates to an input device for a computer, and more particularly to an infrared (IR) touch screen for a video monitor that serves as a computer input device.
  • IR infrared
  • Infrared touch screens which utilize vertical and horizontal arrays of IR emitters and sensors disposed about the rim of the screen of a video monitor to form a grid of IR beams superposed in a plane over the screen 10 of the monitor.
  • the emitters are sequentially activated and opposing sensors are likewise scanned for sensing the presence or absence of an IR beams from the respective opposing emitters.
  • a pointed object or finger is placed near the screen of the monitor, thereby blocking vertical and horizontal IR beams, the position of the object in the grid is detected by the output of the X-Y sensors that are optically aligned with the blocked beams.
  • IR touch screens In known IR touch screens, the IR emitters and sensors and the hardware associated therewith for driving the emitters and scanning the sensors are built into the video monitor or retrofitted internally into the monitor. This requires either specially manufacturing a touch screen monitor, which is obviously expensive for both the manufac- turer and consumer, or opening up a monitor to retrofit the touch screen optoelectronics which poses the danger of damaging internal components of the monitor, again an undesirable consequence for the consumer/user. It therefore would be desireable to have a relatively inexpensive IR touch screen device that could be externally adapted to a wide variety of video monitors for serving as an input device to a computer by simply plugging the device into the serial input port of the computer, similar to known mouse or joy stick input devices. Such an externally adaptable touch screen 10 device could be massed produced relatively inexpensively and selectively applied to a user's monitor without risking damage to internal components of the monitor.
  • IR touch screens that have been developed so far suffer from a relatively low resolution and slow response time.
  • overall resolution of an IR touch screen is limited by the physical size of the of the IR emitter-sensor pair devices.
  • the smallest known devices of this type force a limit to the grid dimension on the order of 0.25 inches.
  • Even if smaller emitter-sensor pairs were available to reduce the grid dimensions and thereby increase the resolution of the touch screen the required overall scanning time would be undesirably increased due to the increased number of sensing elements that would need to be scanned and due to the fact that the scanning time is fixed for each element. It would therefore be advantageous if the resolution of an IR touch screen could be increased without decreasing the scanning speed, and if possible to, to increase the resolution simultaneously with an increase in scanning speed.
  • a further problem with known IR touch screens has to do with signal to noise ratio of the IR sensors which are sensitive to broad band light.
  • the signal to noise ratio can be degraded by the variable ambient light conditions in which the touch screens may be operated.
  • a related problem concerns the fact that the infrared emitters emit infrared light which is projected over a relatively wide angle so that the infrared light actually illuminates a number of oppositely disposed infrared sensors.
  • the infrared sensors have a relatively wide viewing angle and thus can sense the infrared light projected by a number of oppositely disposed infrared emitters. The output of a sensor is thus unintentionally raised by infrared light from emitters on either side of the optically aligned emitter which, combined with a low signal to noise ratio could, result in an erroneous output.
  • an infrared touch screen device that is externally adaptable to a video monitor for serving as an input device to a computer connected to the monitor, including: a bezel adapted to be releasably secured over a viewing end of a video monitor, the bezel defining an opening through which a screen of a monitor to which the bezel is attached can be viewed; a planar transparent screen secured to the bezel and covering the opening; infrared beam generating means mounted on the bezel for generating a grid of infrared beams adjacent the planar transparent screen on a side of the planar transparent screen remote from a screen of a video monitor to which the bezel is to be attached; sensing means mounted on the bezel for sensing the presence and absence of respective beams in the grid and producing output signals corresponding to the presence and absence, respectively, of the infrared beams; and communication means for
  • an infrared touch screen device that is externally adaptable to a video monitor for serving as an input device to a computer connected to the monitor, including: a bezel adapted to be to be releasably secured over a viewing end of a video monitor, the bezel defining an interior space through which a screen of a monitor to which the bezel is attached can be viewed; a plurality of infrared emitters disposed along the bezel to form a grid of vertical and horizontal infrared beams in the interior space when the emitters are activated; a plurality of infrared sensors disposed along the bezel, each sensor being optically aligned with an oppositely disposed one of the emitters; activating means mounted on the bezel for sequentially activating, in a predetermined sequence, respective ones of the emitters; scanning means mounted on the bezel for sequentially scanning the sensors in a sequence corresponding to the predetermined sequence, the sensors each producing output signals corresponding to the presence and absence, respectively, of in
  • the IR touch screen device is an externally adaptable module that requires no internal modification to an already manufactured video monitor.
  • a planar transparent screen is disposed in the interior space of the bezel thereby eliminating the parallax error previously discussed.
  • an infrared passband filter is disposed on the inner edge of the bezel so that the emitted IR beams pass through the filter prior to entering the interior space of the bezel and pass through the filter again upon exiting the interior space prior to being sensed by a sensor, thereby minimizing the effect of ambient light conditions and increasing the signal to noise ratio of the sensor output.
  • the signal to noise ratio is further increase according to another aspect of the invention which employs a unique activating and scanning sequence whereby the viewing angle of a sensor that is being scanned is outside of the projection angle of the next emitter in the sequence that is simultaneously turned on. Therefore each sensor senses only the IR light from its optically aligned emitter, further increasing the signal to noise ratio of the sensor output.
  • the resolution of the IR touch screen is increased by effectively doubling the number of IR beams, without increasing the number of emitter/sensor pairs. This is accomplished by a processing technique that adds virtual beams to the IR beam grid. By determining the midpoint between two blocked IR beams and converting the midpoint to a coordinate, a virtual IR beam is created between every two real beams, thus doubling the resolution.
  • an infrared touch screen for a video monitor for serving as an input device to a computer connected to the monitor, the monitor having a viewing screen and a bezel surrounding the screen and defining an interior space through which the screen can be viewed, including: a plurality of infrared emitters disposed along the bezel to form a grid of vertical and horizontal infrared beams in the interior space when the emitters are activated by an activating current; a plurality of infrared sensors disposed along the bezel, each sensor being optically aligned with an oppositely disposed one of the emitters; activating means for sequentially activating, in a predetermined sequence, respective ones of the emitters, the activating means including means for passing an activating current through respective ones of the emitters in the predetermined sequence; scanning means for sequentially scanning the sensors in a sequence corresponding to the predetermined sequence, the sensors each producing output signals corresponding to the presence and absence, respectively, of an infrared beam emitted by an oppositely disposed
  • the IR touch screen device takes advantage of the fact that the infrared emitters, when activated by an activating current, emit infrared light which builds, essentially exponentially, in intensity to a maximum and when turned off (that is the activating current is interrupted) , the intensity of the light dies down, also essentially in an exponential manner.
  • a fast response time i.e. fast scanning
  • the next IR emitter is turning on, the IR beam from the previously activated IR emitter is being sensed by its optically aligned sensor.
  • the IR emitter turnon time is thereby effectively eliminated from the scanning time, since it is not necessary to have a time delay built into the scanning sequence to accommodate the turn-on time of each emitter.
  • the scanning sequence of the sensors lags behind the activating sequence of the emitters by one IR beam.
  • the touch screen apparatus according to the invention thus significantly increases resolution, has an unparalleled fast response time, is unaffected by ambient light, and advantageously can be totally external to the video monitor that is used.
  • Figure 1 is a block circuit diagram showing a system employing an externally adaptable touch screen device according to the invention.
  • Figure 2 is a front elevational view of an externally adaptable touch screen device in accordance with the invention.
  • Figure 3 is a cross sectional view of Figure 1 along section line A-A as shown.
  • Figure 4 is a schematic showing a plan view of the printed circuit board of Figure 3 illustrating the arrange ⁇ ment of IR emitters, IR sensors and other associated electronic circuitry, a ⁇ well as the grid of IR beams formed thereby.
  • Figures 5A and 5B are diagrams illustrating parallax error and how it is overcome by the principles of the present invention.
  • Figure 6 is a block circuit diagram of an embodiment showing the electronics of a touch screen device in accordance with the principles of the invention.
  • Figures 7A, 7B and 7C are circuit schematics of the electronics shown in the block circuit diagram of Figure 6.
  • Figure 8 is a schematic showing the projection angle of an IR emitter and viewing angle of an IR sensor which is used in explaining the activation and scanning sequences according to the invention.
  • Figure 9 is a timing diagram showing an IR emitter activation sequence and IR sensor scanning sequence employed according to a preferred embodiment of the invention.
  • Figures 10A1-10A7, 10B1-10B2, and 10C1-10C5 are flow charts for a computer program for operating the microcontroller shown in Figure 7 according to a preferred embodiment of the invention.
  • a computer 100 connected to a monitor 101, such as a VGA monitor, and to several input devices, including a keyboard 102, a mouse 103 and a touch screen device 104, the latter being the subject of the present invention.
  • Touch screen devices are generally known. Basically, it is an interactive computer input device which allows the user to input a command to the computer by placing an object, such as a pointer or the user's finger on or near the screen of the monitor to select e04command graphically displayed on the monitor.
  • Previously known touch screen devices were built into the monitor itself during manufacture or internally retrofitted into the monitor.
  • FIG. 2 is a front view of the touch screen 104 of the invention which includes a bezel 106 having top and bottom rim portions 108 and 110, respectively, and side rim portions 112, 114. Rim portions 108, 110, 112 and 114 are shaped to fit over the existing bezel (not shown) of a video monitor.
  • Bottom rim portion 110 is shown having a recess 116 to accommodate a pin connection (not shown) for a cable 105 (Figure 1) to connect a printed circuit board 118 ( Figure 3) mounted in the back side of bezel 106 to an input port of a computer.
  • Bezel 106 has an inner edge 120 surrounding an interior opening 122 which is covered with a planar transparent screen 124 sealed around its periphery with respect to inner edge 120 against the ingress of dust, humidity and liquid to protect the screen of a monitor with which touch screen 104 is used.
  • screen 124 is made of a polycarbonate VUEGUARD 901AG-CLR having anti-scratch and anti-reflective coatings, as is known in the art.
  • Figure 2 also shows the edge of an optical 126 having an infrared passband fastened to inner edge 120 around the inner periphery of bezel 106.
  • circuit board 118 is suitably mounted in an interior recess 128 formed within rim portions 108, 110, 112 and 114. Only the top and bottom portions of circuit board 118 are visible in the cross section of Figure 3.
  • Circuit board 118 mounts a plurality of IR emitters Dl to D64 (see Figure 4) adjacent filter 126 at the bottom and one side of bezel 106 and a plurality of IR sensors SI to S64 (see Figure 4) at the top and other side of bezel 106.
  • Each IR emitter is paired with an oppositely disposed, optically aligned IR sensor, only one such pair DX, SX being visible in the cross section of Figure 3.
  • Circuit board 118 additionally mounts circuit components as shown in Figure 4 for sequentially activating and scanning the IR emitters and sensors as will be described below.
  • IR emitters Dl to D64 are sequentially activated according to a predetermined sequence described hereinafter to form an X-Y grid 142 of IR beams immediately in front of planar transparent screen 124.
  • bezel 106 is provided with detents 134 and 136 on the interior of the top and bottom walls 138 and 140, respectively, which cooperate with suitable openings provided in the bezel of the monitor to which bezel 104 is attached for securing bezel 104 to the monitor.
  • Other suitable mechanisms for securing bezel 104 to a monitor will be apparent to those skilled in the art.
  • Figures 5A and 5B illustrate the problem of parallax error and its correction according to one aspect of the invention.
  • Figure 5A depicts a prior art arrangement in which parallax error is present.
  • a curved screen 144 of a video monitor (not shown) displays a number of soft keys 146 which when touched, for example by a finger 148, are intended to send a command to a computer operatively connected to the monitor. This is accomplished by interrupting or blocking intersecting IR beams in the IR beam grid 142 in an active IR area 151 in front of a selected soft key 146 as will be understood by those skilled in the art.
  • the coordinates of the blocked beams are not associated with any command recognized by the operating software in the computer) .
  • parallax error occurs more frequently towards the edge of the screen of the monitor where the curvature is greatest relative to the line of sight of the user.
  • Figure 5B shows how parallax error is minimized by the principles of the present invention.
  • planar transparent screen 124 in front of monitor screen 144, and creating IR beam grid 142 directly in front of planar screen 124, the user's finger 148 or other pointer only passes a short distance through the IR grid before being stopped by planar screen 124, thus minimizing the possibility of unintentionally blocking IR beams outside of the active IR area in front of the desired soft key.
  • FIG. 6 there is shown a block circuit diagram of the electronics integrated into the externally adaptable bezel according to one embodiment of the invention.
  • an infrared matrix array 12 of infrared emitters Dl to D64 is disposed along the bottom and left-hand side of the bezel and a sequential sensor array 14 of infrared sensors SI to S64 is disposed at the top and right-hand side of the bezel as previously shown and discussed.
  • the infrared emitter array 12 is activated by x-axis and y-axis drivers 16 and 18, respectively, which are in turn controlled by drive-ahead logic 20 to be described.
  • Sequential sensor array 14 is connected to a multiplexer 26 which is controlled by look-behind logic 28 to be described.
  • Look-behind logic 28 and drive-ahead logic 20 communicate with an 8-bit microcontroller 30 by way of I/O control 32, peripheral decoder 34, and system bus 36.
  • Multiplexer 26 additionally has a feedback to microcontroller 30.
  • Microcontroller 30 includes a program memory 38 and data memory 40, whic for purposes of illustration are separately shown.
  • the c _put of the touch screen device is communicated by microcontr ⁇ oller 30 as an input to a host computer (not shown in Figure 6) by way of a serial communication channel 42 and a suitable interface 44.
  • Figures 7A, 7B and 7C show a circuit schematic im ⁇ plementing the block circuit diagram of Figure 6.
  • an 8-bit microcontroller 50 such as an Intel P8048H, forms the heart of the system for controlling the activation and scanning of the IR emitters and sensors.
  • the program memory of the Intel P8048H is a non-volatile memory cell array, having a total size of one thousand twenty four bytes, which is adequate for accommodating an average instruction length of two bytes.
  • Data memory residing in the Intel P8048H has a total memory length of 64 bytes. Sixteen locations are used for working registers (RO to R7 and RO' to R7') . Sixteen other locations are used for the eight level stack. Therefore, the total user data memory is limited to 32 bytes.
  • Microcontroller 50 in Figure 7A corresponds to 8-bit microcontroller 30, system bus 36, program memory 38 and data memory 40 of Figure 6. Other commercially available 8-bit microcontrollers may be employed for implementing the invention as will be apparent to those skilled in the art.
  • a resistor Rl and a capacitor C9 are connected to the reset input of microcontroller 50 to form a time delay to insure the proper hardware start-up for the microcontroller after power-up.
  • Bidirectional pin TO of microcontroller 50 is programmed as an output to be used as a clock generator for a serial communications device 52, which may be imple ⁇ mented, for example, by an Intel P8251A.
  • Software in micro-controller 50 programs one third (1.2288 MHz) of the internal clock (3.6864 MHz) to pin TO.
  • the resulting digital clock output is connected to the clock input of serial communications device 52 and to a binary counter 53 used as a frequency divider to generate the 76.8 KHz needed for the communications baud rate that is finally connected to the transmitter clock input (TXC) and receiver clock input (RXC) of communications device 52.
  • TXC transmitter clock input
  • RXC receiver clock input
  • the microcontroller program will set the transmitting and receiving clock rates to 1/16 of this frequency, resulting in a baud rate of 4800 (equivalent to a communications speed of 480 bytes per second) .
  • Devices 52 and 53 in Figure 7A correspond to serial communications channel 42 in Figure 6.
  • Microcontroller 50 controls, reads and writes to communications device 52 via the system bus and the lower three bits (P2.0 to P2.2) of parallel port P2.
  • Communica- tions device 52 sends, receives and controls the handshake through its pins TXD, RXD, RTS and CTS.
  • a character arrives at communications device 52 it raises the output control pin RXRDY that is connected to a silicon NPN transistor (type 2N3904) G17 used to invert the polarity of this signal and finally generate an interrupt to microcontroller 50 via the INT pin.
  • a level converter device 54 such as a Maxim 233, is used to provide the corresponding RS-232 standard communication levels.
  • the output of this converter is finally wired to a 9 pin, DB-type, female connector 56 whose pin arrangement matches the standard IBMPC configuration.
  • Converter device 54 and connector 56 correspond to interface 44 shown in Figure 6.
  • the PI.7 output of microcontroller 50 is connected to a low power transistor (2N2905A) G18 used to drive a built-in beeper Bl used as an audio transducer.
  • the infrared matrix array 12 of Figure 6 is schematically shown in Figure 7B as comprising the sixty-four infrared emitters Dl to D64 arranged electrically in an 8 X 8 matrix.
  • the emitters are preferably gallium-aluminumarsenide semiconductor light emitting diodes, such as a General Electric F5D1, which has a peak emission of 6 milliwatts at a wavelength of 880 nanometers.
  • a General Electric F5D1 General Electric
  • an X-Y matrix of sixteen semiconductor drivers is employed.
  • the eight NPN (2N2222) transistors (Gl, G3, G5, G7, G9, Gil, G13 and G15) are connected on the Y-axis so that each NPN transistor is connected to a respective one of the eight cathodes of the emitters in the respective rows as shown and the eight PNP (2N2905) transistors (G2, G4, G6, G8, G10, G12, G14 and G16) are connected on the X-axis so that each PNP transistor is connected to a respective one of the eight anodes of the emitters in the respective columns as shown.
  • Emitters Dl to D64 are activated in numerical sequence by selectively turning on the appropriate row and column transistors.
  • emitters Dl to D64 Although for purposes of illustration and ease of explanation of the electrical connection of emitters Dl to D64 they are shown arranged in a matrix, the actual placement of emitters Dl to D64 around the bezel is as illustrated in Figure 4. Thus, although the emitters are activated in numerical sequence, the sequence in which the IR beams are formed in grid 142 shown in Figure 4 depends on the actual placement of the emitters around the bezel which is an important feature of the invention as will become apparent from subsequent description.
  • the semiconductor drivers Gl to G16 are energized by way of decoding logic implemented by semiconductor chips 58A, 58B and 58C, which preferably comprise integrated circuit types 74LS138, 74LS240 and 74LS138, respectively, as controlled by microprocessor 50.
  • the lower seven bits, Pi.O to PI.6, of parallel port PI of microprocessor 50 are used to generate the control signals for the decoding logic.
  • pins PI.O to PI.2 and PI.6 are connected to chip 58C to control the X-axis semiconductor drivers G2, G4, G6, G8, G10, G12, G14 and G16 and pins PI.3 to PI.5 are routed to chip 58A whose outputs YO to Y7 are routed to chip 58C for controlling the Y-axis semiconductor drivers Gl, G3, G5, G7, G9, Gil, G13 and G15.
  • the sequence by which emitters Dl to D64 are activated is referred to as drive-ahead logic because the energized emitter is always one beam ahead of the sensor that is being scanned as will be further explained below.
  • sensors SI to S64 arranged in four columns 60A, 60B, 60C and 60D, respectively.
  • sensors SI to S64 each comprise a phototransistor connected in an emitter follower configuration.
  • the phototransistor is preferably type SPDT manufactured by Silicon Sensors, Inc. which is a full-visible band silicon phototransistor with enhanced response in the infrared region (790 to 1200 nanometers) , thus matching the infrared emission of the emitters.
  • Eight multiplexers are provided for scanning the sensors.
  • a first pair of the multiplexers 62A, 62B is connected to sensors in column 60A, with sensors SI to S8 being connected to multiplexer 62A and sensors S9 to S16 being connected to multiplexer 62B.
  • a second pair of multiplexers 64A, 64B is connected to sensors in column 60B, with sensors S17 to S24 being connected to multiplexer 64A and sensors S25 to S32 being connected to multiplexer 64B.
  • a third pair of multiplexers 66A, 66B is connected to sensors in column 60C, with sensors S33 to S40 being connected to multiplexer 66A and sensors S41 to S48 being connected to multiplexer 66B.
  • a fourth pair of multiplexers 68A, 68B is connected to the sensors in the fourth column 60C, with sensors S49 to S56 being connected to multiplexer 68A and sensors S57 to S64 being connected to multiplexer 68B.
  • the multiplexers are each comprised of an integrated circuit type 74HC251.
  • the multiplexers are connected to the output lines of chip 58A as shown for selectively scanning the sensors in a mutually exclusive manner in a sequence corresponding to the sequence for activating the emitters with the exception that the sensor scanning sequence is always one beam behind the activated emitter.
  • the output pin W of each multiplexer is connected to the bidirectional pin TO of microcontroller 50 for reading the output of the respectively scanned sensors.
  • Look-behind logic 28, I/O control 32, peripheral decoder 34 and drive-ahead logic 20 of Figure 6 are implemented by microchips circuits 58A, 58B and 58C as shown in Figure 7A to 7C.
  • Sequential sensor array 14 of Figure 6 is implemented by the columns of transistors 60A, 60B, 60C and 60D, and the pairs of multiplexers 62A-62B, 64A-64B, 66A66B, and 68A-68B constitute exclusive sensor multiplexer 26.
  • Figure 8 is a diagram showing the projection angle of an activated IR emitter on the left-hand side of the figure and the viewing angle of an optically aligned IR sensor being scanned on the right-hand side of the figure.
  • the viewing angle of each sensor has the shape of a cone with an aperture angle of about 60'.
  • the situation illustrated in Figure 8 can present a problem in that there is a turn-on period during which the intensity of IR light from an activated emitter builds up to a maximum intensity and a turn-off period after discontinuance of activating current during which the intensity of IR light from the emitter dies down.
  • its optically aligned sensor may still sense IR light from another oppositely disposed emitter which is just turning on or just turning off and whose projection angle causes IR light to fall on that sensor.
  • the scanned sensor is thus reading the light from the previously activated emitter whose IR light intensity is decreasing from its activated maximum intensity.
  • Figure 9 shows a timing diagram for activating the emitters and scanning the sensors according to an embodiment of the invention, wherein the emitters and sensors are position around the bezel as illustrated in Figure 4.
  • the numbers across the top of the diagram indicate the activated emitters and the numbers down the left-hand side of the diagram indicate the previously activated emitter that is being scanned by a sensor.
  • the numerical counter programmed into microcontroller is reset to 64 and decremented each activation and scan cycle.
  • the sensor opposite the previously activated emitter Dl that sensor being S40
  • a look-up table stored in the software of microcontroller 50 identifies electronic addresses for each decrement of the counter from 64 down to 1 which when decoded by the look-ahead logic identifies the appropriate emitters to be activated and when decoded by the look-behind logic identifies the appropriate sensors to be scanned in accordance with the predetermined sequence illustrated by the timing diagram in Figure 9 and the location of the emitters shown in Figure 4.
  • the activation and scanning sequences ensures that a currently scanned sensor is completely outside of the projection angle of a currently activated emitter and thus can receive IR light only from its optically aligned, previously activated emitter whose IR beam is at that point in time decreasing from its activated maximum intensity.
  • FIGS. 10 series of drawings are flow charts for the computer software operating microcontroller 50 for achieving the activating and scanning sequences discussed above.
  • the microcontroller starts executing code at location 0, where the program forces a branch to the INIT routine (see Figures 10A-2 and 10B-2) , which sets all hardware and data start-up conditions, calls a self-test subprogram, checks the result of the self-test, will report the result of the self-test to the host computer, and branch to execute the MAINL program after enabling the microcontroller for recognition of external interrupts (caused by communications with the host computer) .
  • MAINL shown in Figure lOC-1, as the name suggests, is the main loop (the core of all program operations) . During its execution, it will continuously monitor system variables and current command status. Based on its findings it will force the execution of other subprograms or tasks.
  • SCAN shown in Figure 10C-3, is the subprogram that deals with the actual scanning of the infrared arrays, the one that finds the user's finger, generates the corresponding set of coordinates, converts those into the proper character set, and sends the result to the host computer. Examining the flow-chart, it will be easy to find that as soon as the "activate current IR beam” takes place, the program is reading the "previous beam” (no settling time delay between activation and sensing) . If a beam is found to be blocked, then, a time delay is inserted, on purpose, to verify for the user's positive action and avoid unwanted spurious signals.
  • CONVR shown in Figure lOA-1, is the "blocked beams" to "real coordinates" conversion subprogram. It has embedded a number of intelligent subroutines to verify the integrity of the scan results, to generate the high-resolution virtual beams by finding the center of a large area beam-blockage and averaging the coordinates of the blocked beams, and return the result to the MAINL.
  • the averaging technique in effect creates virtual beams between the real beams, doubling the resolution of the touch screen.
  • TST shown in Figure 10A-3, is the subprogram that executes the self-test at power-up (without human intervention) and the host computer requested continuous test.
  • INT shown in Figure 10C-2, is the subprogram that analyzes and processes the commands received from the host computer.
  • DEL10 shown in Figure 10A-6, is a small time delay subroutine, used by the SCAN subprogram only when a beam is not found and also used by other time delay subroutines as a base delay.
  • DEL100 shown in Figure 10A-7, is a long time delay subroutine, used only by the beeper control subroutines, shown in Figures 10A-4 and 10A-5, (user audio feedback) BEEP1, BEEP2, and BEEP3.
  • SENDCUR (see Figures lOB-1, lOC-l and 10C-2) is a subroutine used in different subprograms to transmit the result of the current scan process to the host computer.
  • SENDER shown in Figure 10C-5, is a general purpose subroutine used in different subprograms to transmit any found error in communications, during the scan process, and/or while executing a test.
  • CHERR (see Figures lOC-l and 10C-3) is a general purpose subroutine that flags a "command-error" type.
  • TXRDY (see Figure 10C-5) is a general purpose subroutine used by any of the serial transmitting tasks, to assure that the communications controller is free to transmit a new data character when needed.
  • the system will use a VGA video monitor display that is capable of 43 lines by 80 columns in text mode, or 640 by 480 graphic pixels.
  • VGA video monitor display that is capable of 43 lines by 80 columns in text mode, or 640 by 480 graphic pixels.
  • the touch-screen developed has a total resolution of 79x47 real and virtual beams that cover all possible needs, the virtual beams being created by averaging the coordinates of multiple blocked beams.
  • the system will provide 3840 touch points on the video screen (matrix of 79 by 47) , enabling the addressing of every character on the screen in VGA mode or even use of graphic capabilities in high resolution video mode.

Abstract

An infrared touch screen device (104) that is externally adaptable to a video monitor (101) for serving as an input device to a computer (100) connected to the monitor (101). A bezel (106) is adapted to be releasably secured over a viewing end of a video monitor (101). A plurality of infrared emitters (D1 to D64, 12) are disposed along the bezel (106) to form a grid of vertical and horizontal infrared beams in the interior space of the bezel (106) when the emitters (D1 to D64, 12) are activated. A plurality of infrared sensors are disposed along the bezel (106). Each sensor (14, S1 to S64) is optically aligned with an oppositely disposed one of the emitters (12, D1 to D64). An activating circuit (118) is mounted on the bezel (106) for sequentially activating, in a predetermined sequence, respective ones of the emitters (D1 to D64, 12).

Description

- ! _
INFRARED TOUCH SCREEN DEVICE FOR A VIDEO MONITOR
BACKGROUND OF THE INVENTION
The present invention relates to an input device for a computer, and more particularly to an infrared (IR) touch screen for a video monitor that serves as a computer input device.
Infrared touch screens are known which utilize vertical and horizontal arrays of IR emitters and sensors disposed about the rim of the screen of a video monitor to form a grid of IR beams superposed in a plane over the screen 10 of the monitor. The emitters are sequentially activated and opposing sensors are likewise scanned for sensing the presence or absence of an IR beams from the respective opposing emitters. When a pointed object or finger is placed near the screen of the monitor, thereby blocking vertical and horizontal IR beams, the position of the object in the grid is detected by the output of the X-Y sensors that are optically aligned with the blocked beams.
In known IR touch screens, the IR emitters and sensors and the hardware associated therewith for driving the emitters and scanning the sensors are built into the video monitor or retrofitted internally into the monitor. This requires either specially manufacturing a touch screen monitor, which is obviously expensive for both the manufac- turer and consumer, or opening up a monitor to retrofit the touch screen optoelectronics which poses the danger of damaging internal components of the monitor, again an undesirable consequence for the consumer/user. It therefore would be desireable to have a relatively inexpensive IR touch screen device that could be externally adapted to a wide variety of video monitors for serving as an input device to a computer by simply plugging the device into the serial input port of the computer, similar to known mouse or joy stick input devices. Such an externally adaptable touch screen 10 device could be massed produced relatively inexpensively and selectively applied to a user's monitor without risking damage to internal components of the monitor.
Further, IR touch screens that have been developed so far suffer from a relatively low resolution and slow response time. Generally speaking, overall resolution of an IR touch screen is limited by the physical size of the of the IR emitter-sensor pair devices. The smallest known devices of this type force a limit to the grid dimension on the order of 0.25 inches. Even if smaller emitter-sensor pairs were available to reduce the grid dimensions and thereby increase the resolution of the touch screen, the required overall scanning time would be undesirably increased due to the increased number of sensing elements that would need to be scanned and due to the fact that the scanning time is fixed for each element. It would therefore be advantageous if the resolution of an IR touch screen could be increased without decreasing the scanning speed, and if possible to, to increase the resolution simultaneously with an increase in scanning speed. Additionally, in known IR touch screens, there exists an aberrational error known as parallax due to the curvature of the screen and the normal human arm and finger mechanics, causing IR beams to the side or above or below the intended pointing location to be blocked, thereby designating an incorrect location on the screen. This problem is more pronounced at the corners of the touch screen. It would be desireable to devise a touch screen to minimize the parallax problem.
A further problem with known IR touch screens has to do with signal to noise ratio of the IR sensors which are sensitive to broad band light. The signal to noise ratio can be degraded by the variable ambient light conditions in which the touch screens may be operated. A related problem concerns the fact that the infrared emitters emit infrared light which is projected over a relatively wide angle so that the infrared light actually illuminates a number of oppositely disposed infrared sensors. Similarly, the infrared sensors have a relatively wide viewing angle and thus can sense the infrared light projected by a number of oppositely disposed infrared emitters. The output of a sensor is thus unintentionally raised by infrared light from emitters on either side of the optically aligned emitter which, combined with a low signal to noise ratio could, result in an erroneous output.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a touch screen device which is externally adaptable to a wide variety of computer monitors for use as a computer input device.
It is a further object of the present invention to provide a high resolution, fast response time touch screen for use as a computer input device.
It is yet another object of the invention to provide a touch screen device that minimizes the problems discussed above. The above and other objects are accomplished according to the invention by the provision of an infrared touch screen device that is externally adaptable to a video monitor for serving as an input device to a computer connected to the monitor, including: a bezel adapted to be releasably secured over a viewing end of a video monitor, the bezel defining an opening through which a screen of a monitor to which the bezel is attached can be viewed; a planar transparent screen secured to the bezel and covering the opening; infrared beam generating means mounted on the bezel for generating a grid of infrared beams adjacent the planar transparent screen on a side of the planar transparent screen remote from a screen of a video monitor to which the bezel is to be attached; sensing means mounted on the bezel for sensing the presence and absence of respective beams in the grid and producing output signals corresponding to the presence and absence, respectively, of the infrared beams; and communication means for communicating the output signals of the sensing means to a computer connected to the monitor to which the bezel is attached. According to another embodiment of the invention there is provided an infrared touch screen device that is externally adaptable to a video monitor for serving as an input device to a computer connected to the monitor, including: a bezel adapted to be to be releasably secured over a viewing end of a video monitor, the bezel defining an interior space through which a screen of a monitor to which the bezel is attached can be viewed; a plurality of infrared emitters disposed along the bezel to form a grid of vertical and horizontal infrared beams in the interior space when the emitters are activated; a plurality of infrared sensors disposed along the bezel, each sensor being optically aligned with an oppositely disposed one of the emitters; activating means mounted on the bezel for sequentially activating, in a predetermined sequence, respective ones of the emitters; scanning means mounted on the bezel for sequentially scanning the sensors in a sequence corresponding to the predetermined sequence, the sensors each producing output signals corresponding to the presence and absence, respectively, of infrared light emitted by an oppositely disposed infrared emitter; and communication means for coupling the output signals of the sensors to an input port of a computer connected to the monitor.
Thus, the IR touch screen device according to the invention is an externally adaptable module that requires no internal modification to an already manufactured video monitor. Further, according to one aspect of the invention a planar transparent screen is disposed in the interior space of the bezel thereby eliminating the parallax error previously discussed. According to yet another aspect of the invention an infrared passband filter is disposed on the inner edge of the bezel so that the emitted IR beams pass through the filter prior to entering the interior space of the bezel and pass through the filter again upon exiting the interior space prior to being sensed by a sensor, thereby minimizing the effect of ambient light conditions and increasing the signal to noise ratio of the sensor output. The signal to noise ratio is further increase according to another aspect of the invention which employs a unique activating and scanning sequence whereby the viewing angle of a sensor that is being scanned is outside of the projection angle of the next emitter in the sequence that is simultaneously turned on. Therefore each sensor senses only the IR light from its optically aligned emitter, further increasing the signal to noise ratio of the sensor output. In yet another aspect of the invention the resolution of the IR touch screen is increased by effectively doubling the number of IR beams, without increasing the number of emitter/sensor pairs. This is accomplished by a processing technique that adds virtual beams to the IR beam grid. By determining the midpoint between two blocked IR beams and converting the midpoint to a coordinate, a virtual IR beam is created between every two real beams, thus doubling the resolution.
According to another embodiment of the invention there is provided an infrared touch screen for a video monitor for serving as an input device to a computer connected to the monitor, the monitor having a viewing screen and a bezel surrounding the screen and defining an interior space through which the screen can be viewed, including: a plurality of infrared emitters disposed along the bezel to form a grid of vertical and horizontal infrared beams in the interior space when the emitters are activated by an activating current; a plurality of infrared sensors disposed along the bezel, each sensor being optically aligned with an oppositely disposed one of the emitters; activating means for sequentially activating, in a predetermined sequence, respective ones of the emitters, the activating means including means for passing an activating current through respective ones of the emitters in the predetermined sequence; scanning means for sequentially scanning the sensors in a sequence corresponding to the predetermined sequence, the sensors each producing output signals corresponding to the presence and absence, respectively, of an infrared beam emitted by an oppositely disposed infrared emitter, the corresponding sequence by which the scanning means scans the oppositely disposed sensors lagging the predetermined sequence by a predetermined time delay; and communication means for coupling the output signals of the sensors to an input of a computer connected to the monitor.
The IR touch screen device according to this embodiment of the invention takes advantage of the fact that the infrared emitters, when activated by an activating current, emit infrared light which builds, essentially exponentially, in intensity to a maximum and when turned off (that is the activating current is interrupted) , the intensity of the light dies down, also essentially in an exponential manner. A fast response time (i.e. fast scanning) is obtained by scanning each IR sensor just after the light from its oppositely disposed IR emitter is turned off, while simultaneously the next IR emitter in the sequence is activated. Thus, while the next IR emitter is turning on, the IR beam from the previously activated IR emitter is being sensed by its optically aligned sensor. The IR emitter turnon time is thereby effectively eliminated from the scanning time, since it is not necessary to have a time delay built into the scanning sequence to accommodate the turn-on time of each emitter. In effect, the scanning sequence of the sensors lags behind the activating sequence of the emitters by one IR beam.
The touch screen apparatus according to the invention thus significantly increases resolution, has an unparalleled fast response time, is unaffected by ambient light, and advantageously can be totally external to the video monitor that is used.
Other features and advantages will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.
BRIEF DESCRIPTION F THE DRAWINGS
Figure 1 is a block circuit diagram showing a system employing an externally adaptable touch screen device according to the invention.
Figure 2 is a front elevational view of an externally adaptable touch screen device in accordance with the invention.
Figure 3 is a cross sectional view of Figure 1 along section line A-A as shown.
Figure 4 is a schematic showing a plan view of the printed circuit board of Figure 3 illustrating the arrange¬ ment of IR emitters, IR sensors and other associated electronic circuitry, aε well as the grid of IR beams formed thereby.
Figures 5A and 5B are diagrams illustrating parallax error and how it is overcome by the principles of the present invention.
Figure 6 is a block circuit diagram of an embodiment showing the electronics of a touch screen device in accordance with the principles of the invention. Figures 7A, 7B and 7C are circuit schematics of the electronics shown in the block circuit diagram of Figure 6. Figure 8 is a schematic showing the projection angle of an IR emitter and viewing angle of an IR sensor which is used in explaining the activation and scanning sequences according to the invention. Figure 9 is a timing diagram showing an IR emitter activation sequence and IR sensor scanning sequence employed according to a preferred embodiment of the invention.
Figures 10A1-10A7, 10B1-10B2, and 10C1-10C5 are flow charts for a computer program for operating the microcontroller shown in Figure 7 according to a preferred embodiment of the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to Figure 1, there is shown a computer 100 connected to a monitor 101, such as a VGA monitor, and to several input devices, including a keyboard 102, a mouse 103 and a touch screen device 104, the latter being the subject of the present invention. Touch screen devices are generally known. Basically, it is an interactive computer input device which allows the user to input a command to the computer by placing an object, such as a pointer or the user's finger on or near the screen of the monitor to select e04command graphically displayed on the monitor. Previously known touch screen devices were built into the monitor itself during manufacture or internally retrofitted into the monitor. The present invention involves, in one embodiment, an externally adaptable touch screen device which can be used with a wide variety of monitors as will become clear from the following description. Additionally, certain principles of operation of the touch screen device according to the invention can be incorporated into a touch screen device built internally into a monitor for achieving greater resolution and higher scanning speeds as will further become clear from the following description. Figure 2 is a front view of the touch screen 104 of the invention which includes a bezel 106 having top and bottom rim portions 108 and 110, respectively, and side rim portions 112, 114. Rim portions 108, 110, 112 and 114 are shaped to fit over the existing bezel (not shown) of a video monitor. Bottom rim portion 110 is shown having a recess 116 to accommodate a pin connection (not shown) for a cable 105 (Figure 1) to connect a printed circuit board 118 (Figure 3) mounted in the back side of bezel 106 to an input port of a computer. Bezel 106 has an inner edge 120 surrounding an interior opening 122 which is covered with a planar transparent screen 124 sealed around its periphery with respect to inner edge 120 against the ingress of dust, humidity and liquid to protect the screen of a monitor with which touch screen 104 is used. Desirably, , screen 124 is made of a polycarbonate VUEGUARD 901AG-CLR having anti-scratch and anti-reflective coatings, as is known in the art. Figure 2 also shows the edge of an optical 126 having an infrared passband fastened to inner edge 120 around the inner periphery of bezel 106.
As shown in the cross sectional view of Figure 3, circuit board 118 is suitably mounted in an interior recess 128 formed within rim portions 108, 110, 112 and 114. Only the top and bottom portions of circuit board 118 are visible in the cross section of Figure 3. Circuit board 118 mounts a plurality of IR emitters Dl to D64 (see Figure 4) adjacent filter 126 at the bottom and one side of bezel 106 and a plurality of IR sensors SI to S64 (see Figure 4) at the top and other side of bezel 106. Each IR emitter is paired with an oppositely disposed, optically aligned IR sensor, only one such pair DX, SX being visible in the cross section of Figure 3. Circuit board 118 additionally mounts circuit components as shown in Figure 4 for sequentially activating and scanning the IR emitters and sensors as will be described below. IR emitters Dl to D64 are sequentially activated according to a predetermined sequence described hereinafter to form an X-Y grid 142 of IR beams immediately in front of planar transparent screen 124. As further shown in Figure 3, bezel 106 is provided with detents 134 and 136 on the interior of the top and bottom walls 138 and 140, respectively, which cooperate with suitable openings provided in the bezel of the monitor to which bezel 104 is attached for securing bezel 104 to the monitor. Other suitable mechanisms for securing bezel 104 to a monitor will be apparent to those skilled in the art.
Figures 5A and 5B illustrate the problem of parallax error and its correction according to one aspect of the invention. Figure 5A depicts a prior art arrangement in which parallax error is present. As can be seen from this figure, a curved screen 144 of a video monitor (not shown) displays a number of soft keys 146 which when touched, for example by a finger 148, are intended to send a command to a computer operatively connected to the monitor. This is accomplished by interrupting or blocking intersecting IR beams in the IR beam grid 142 in an active IR area 151 in front of a selected soft key 146 as will be understood by those skilled in the art. However, because screen 144 of the monitor is curved and grid 142 is separated a finite distance in front of screen 144, and further due to the fact that the user's line of sight is not always head-on to the desired touch point, the finger 148 or other pointer of the user may cross the IR grid 142 in a location not directly in front of the desired touch point, thus unintentionally blocking IR beams outside of the desired soft key area in an inactive area 153 and/or an adjacent active area 151 in front of an adjacent soft key. This could have the effect of sending an undesired command from an adjacent soft key to the computer or possibly no command if the blocked IR beams are in an inactive area (i.e. the coordinates of the blocked beams are not associated with any command recognized by the operating software in the computer) . As may be appreciated, parallax error occurs more frequently towards the edge of the screen of the monitor where the curvature is greatest relative to the line of sight of the user.
Figure 5B shows how parallax error is minimized by the principles of the present invention. As can be seen from this figure, by placing planar transparent screen 124 in front of monitor screen 144, and creating IR beam grid 142 directly in front of planar screen 124, the user's finger 148 or other pointer only passes a short distance through the IR grid before being stopped by planar screen 124, thus minimizing the possibility of unintentionally blocking IR beams outside of the active IR area in front of the desired soft key.
Referring to Figure 6, there is shown a block circuit diagram of the electronics integrated into the externally adaptable bezel according to one embodiment of the invention. As shown in this figure, an infrared matrix array 12 of infrared emitters Dl to D64 is disposed along the bottom and left-hand side of the bezel and a sequential sensor array 14 of infrared sensors SI to S64 is disposed at the top and right-hand side of the bezel as previously shown and discussed. The infrared emitter array 12 is activated by x-axis and y-axis drivers 16 and 18, respectively, which are in turn controlled by drive-ahead logic 20 to be described. Sequential sensor array 14 is connected to a multiplexer 26 which is controlled by look-behind logic 28 to be described. Look-behind logic 28 and drive-ahead logic 20 communicate with an 8-bit microcontroller 30 by way of I/O control 32, peripheral decoder 34, and system bus 36. Multiplexer 26 additionally has a feedback to microcontroller 30. Microcontroller 30 includes a program memory 38 and data memory 40, whic for purposes of illustration are separately shown. The c _put of the touch screen device is communicated by microcontr¬ oller 30 as an input to a host computer (not shown in Figure 6) by way of a serial communication channel 42 and a suitable interface 44. Figures 7A, 7B and 7C show a circuit schematic im¬ plementing the block circuit diagram of Figure 6. Referring first to Figure 7A, an 8-bit microcontroller 50, such as an Intel P8048H, forms the heart of the system for controlling the activation and scanning of the IR emitters and sensors. The low cost of the Intel P8048H microcontroller and its characteristics including a built-in program memory, data memory, two parallel ports (PI and P2) , a timer-counter, a system bus (address, data and bus control) , a system clock generator, one interrupt input, two programmable bidirectional bits (TO and TI) , and one hardware reset input, make this device particularly suitable for running the system according to the invention. The program memory of the Intel P8048H is a non-volatile memory cell array, having a total size of one thousand twenty four bytes, which is adequate for accommodating an average instruction length of two bytes. Data memory residing in the Intel P8048H has a total memory length of 64 bytes. Sixteen locations are used for working registers (RO to R7 and RO' to R7') . Sixteen other locations are used for the eight level stack. Therefore, the total user data memory is limited to 32 bytes. Microcontroller 50 in Figure 7A corresponds to 8-bit microcontroller 30, system bus 36, program memory 38 and data memory 40 of Figure 6. Other commercially available 8-bit microcontrollers may be employed for implementing the invention as will be apparent to those skilled in the art.
A resistor Rl and a capacitor C9 are connected to the reset input of microcontroller 50 to form a time delay to insure the proper hardware start-up for the microcontroller after power-up. Bidirectional pin TO of microcontroller 50 is programmed as an output to be used as a clock generator for a serial communications device 52, which may be imple¬ mented, for example, by an Intel P8251A. Software in micro-controller 50 programs one third (1.2288 MHz) of the internal clock (3.6864 MHz) to pin TO. The resulting digital clock output is connected to the clock input of serial communications device 52 and to a binary counter 53 used as a frequency divider to generate the 76.8 KHz needed for the communications baud rate that is finally connected to the transmitter clock input (TXC) and receiver clock input (RXC) of communications device 52. During initialization the microcontroller program will set the transmitting and receiving clock rates to 1/16 of this frequency, resulting in a baud rate of 4800 (equivalent to a communications speed of 480 bytes per second) . Devices 52 and 53 in Figure 7A correspond to serial communications channel 42 in Figure 6.
Microcontroller 50 controls, reads and writes to communications device 52 via the system bus and the lower three bits (P2.0 to P2.2) of parallel port P2. Communica- tions device 52 sends, receives and controls the handshake through its pins TXD, RXD, RTS and CTS. When a character arrives at communications device 52 it raises the output control pin RXRDY that is connected to a silicon NPN transistor (type 2N3904) G17 used to invert the polarity of this signal and finally generate an interrupt to microcontroller 50 via the INT pin. A level converter device 54, such as a Maxim 233, is used to provide the corresponding RS-232 standard communication levels. The output of this converter is finally wired to a 9 pin, DB-type, female connector 56 whose pin arrangement matches the standard IBMPC configuration. Converter device 54 and connector 56 correspond to interface 44 shown in Figure 6. The PI.7 output of microcontroller 50 is connected to a low power transistor (2N2905A) G18 used to drive a built-in beeper Bl used as an audio transducer.
The infrared matrix array 12 of Figure 6 is schematically shown in Figure 7B as comprising the sixty-four infrared emitters Dl to D64 arranged electrically in an 8 X 8 matrix. The emitters are preferably gallium-aluminumarsenide semiconductor light emitting diodes, such as a General Electric F5D1, which has a peak emission of 6 milliwatts at a wavelength of 880 nanometers. To sequentially energize emitters Dl to D64, an X-Y matrix of sixteen semiconductor drivers is employed. The eight NPN (2N2222) transistors (Gl, G3, G5, G7, G9, Gil, G13 and G15) are connected on the Y-axis so that each NPN transistor is connected to a respective one of the eight cathodes of the emitters in the respective rows as shown and the eight PNP (2N2905) transistors (G2, G4, G6, G8, G10, G12, G14 and G16) are connected on the X-axis so that each PNP transistor is connected to a respective one of the eight anodes of the emitters in the respective columns as shown. Emitters Dl to D64 are activated in numerical sequence by selectively turning on the appropriate row and column transistors.
Although for purposes of illustration and ease of explanation of the electrical connection of emitters Dl to D64 they are shown arranged in a matrix, the actual placement of emitters Dl to D64 around the bezel is as illustrated in Figure 4. Thus, although the emitters are activated in numerical sequence, the sequence in which the IR beams are formed in grid 142 shown in Figure 4 depends on the actual placement of the emitters around the bezel which is an important feature of the invention as will become apparent from subsequent description.
The semiconductor drivers Gl to G16 are energized by way of decoding logic implemented by semiconductor chips 58A, 58B and 58C, which preferably comprise integrated circuit types 74LS138, 74LS240 and 74LS138, respectively, as controlled by microprocessor 50. The lower seven bits, Pi.O to PI.6, of parallel port PI of microprocessor 50 are used to generate the control signals for the decoding logic. Referring additionally to Figure 7C, it can be seen that pins PI.O to PI.2 and PI.6 are connected to chip 58C to control the X-axis semiconductor drivers G2, G4, G6, G8, G10, G12, G14 and G16 and pins PI.3 to PI.5 are routed to chip 58A whose outputs YO to Y7 are routed to chip 58C for controlling the Y-axis semiconductor drivers Gl, G3, G5, G7, G9, Gil, G13 and G15. The sequence by which emitters Dl to D64 are activated is referred to as drive-ahead logic because the energized emitter is always one beam ahead of the sensor that is being scanned as will be further explained below. Referring to Figure 7C, there is shown 64 IR sensors SI to S64 arranged in four columns 60A, 60B, 60C and 60D, respectively. In a preferred embodiment sensors SI to S64 each comprise a phototransistor connected in an emitter follower configuration. The phototransistor is preferably type SPDT manufactured by Silicon Sensors, Inc. which is a full-visible band silicon phototransistor with enhanced response in the infrared region (790 to 1200 nanometers) , thus matching the infrared emission of the emitters. Eight multiplexers are provided for scanning the sensors. A first pair of the multiplexers 62A, 62B is connected to sensors in column 60A, with sensors SI to S8 being connected to multiplexer 62A and sensors S9 to S16 being connected to multiplexer 62B. A second pair of multiplexers 64A, 64B is connected to sensors in column 60B, with sensors S17 to S24 being connected to multiplexer 64A and sensors S25 to S32 being connected to multiplexer 64B. A third pair of multiplexers 66A, 66B is connected to sensors in column 60C, with sensors S33 to S40 being connected to multiplexer 66A and sensors S41 to S48 being connected to multiplexer 66B. A fourth pair of multiplexers 68A, 68B is connected to the sensors in the fourth column 60C, with sensors S49 to S56 being connected to multiplexer 68A and sensors S57 to S64 being connected to multiplexer 68B. In a preferred embodiment the multiplexers are each comprised of an integrated circuit type 74HC251.
The multiplexers are connected to the output lines of chip 58A as shown for selectively scanning the sensors in a mutually exclusive manner in a sequence corresponding to the sequence for activating the emitters with the exception that the sensor scanning sequence is always one beam behind the activated emitter. The output pin W of each multiplexer is connected to the bidirectional pin TO of microcontroller 50 for reading the output of the respectively scanned sensors.
Look-behind logic 28, I/O control 32, peripheral decoder 34 and drive-ahead logic 20 of Figure 6 are implemented by microchips circuits 58A, 58B and 58C as shown in Figure 7A to 7C. Sequential sensor array 14 of Figure 6 is implemented by the columns of transistors 60A, 60B, 60C and 60D, and the pairs of multiplexers 62A-62B, 64A-64B, 66A66B, and 68A-68B constitute exclusive sensor multiplexer 26.
Figure 8 is a diagram showing the projection angle of an activated IR emitter on the left-hand side of the figure and the viewing angle of an optically aligned IR sensor being scanned on the right-hand side of the figure. As can be seen, due to the dispersion of the IR beam a number of oppositely disposed sensors on either side of the optically aligned sensor are bathed with IR light. Concomitantly, the viewing angle of each sensor has the shape of a cone with an aperture angle of about 60'. The situation illustrated in Figure 8 can present a problem in that there is a turn-on period during which the intensity of IR light from an activated emitter builds up to a maximum intensity and a turn-off period after discontinuance of activating current during which the intensity of IR light from the emitter dies down. As a result, if the IR beam of an emitter is blocked, its optically aligned sensor may still sense IR light from another oppositely disposed emitter which is just turning on or just turning off and whose projection angle causes IR light to fall on that sensor. To avoid this problem, it is a feature of the present invention to scan the sensors one beam behind the activated emitters and to position the sensors relative to the emitters so that a currently scanned sensor is outside of the projection angle of a currently activated emitter. The scanned sensor is thus reading the light from the previously activated emitter whose IR light intensity is decreasing from its activated maximum intensity. This activating and scanning sequence has the added benefit of increasing the scanning rate since it is not necessary to build in a delay in the scanning sequence to separately accommodate the turn-on period of each emitter.
Figure 9 shows a timing diagram for activating the emitters and scanning the sensors according to an embodiment of the invention, wherein the emitters and sensors are position around the bezel as illustrated in Figure 4. In Figure 9, the numbers across the top of the diagram indicate the activated emitters and the numbers down the left-hand side of the diagram indicate the previously activated emitter that is being scanned by a sensor. It should also be borne in mind that the numerical counter programmed into microcontroller is reset to 64 and decremented each activation and scan cycle. Thus, when emitter D64 is activated by its corresponding drivers G6 and G15 (see Figure 7B) , the sensor opposite the previously activated emitter Dl (that sensor being S40) is scanned. When the next emitter D63 is activated by its corresponding drivers G4 and G15, the sensor opposite the previously activated emitter D64 (that sensor being S39) is scanned. When the next emitter D62 is activated by its corresponding drivers, the sensor opposite the previously activated emitter D63 (that sensor being S38) is scanned, and so on. A look-up table stored in the software of microcontroller 50 identifies electronic addresses for each decrement of the counter from 64 down to 1 which when decoded by the look-ahead logic identifies the appropriate emitters to be activated and when decoded by the look-behind logic identifies the appropriate sensors to be scanned in accordance with the predetermined sequence illustrated by the timing diagram in Figure 9 and the location of the emitters shown in Figure 4. The activation and scanning sequences ensures that a currently scanned sensor is completely outside of the projection angle of a currently activated emitter and thus can receive IR light only from its optically aligned, previously activated emitter whose IR beam is at that point in time decreasing from its activated maximum intensity.
The Figure 10 series of drawings are flow charts for the computer software operating microcontroller 50 for achieving the activating and scanning sequences discussed above. At power-up, the microcontroller starts executing code at location 0, where the program forces a branch to the INIT routine (see Figures 10A-2 and 10B-2) , which sets all hardware and data start-up conditions, calls a self-test subprogram, checks the result of the self-test, will report the result of the self-test to the host computer, and branch to execute the MAINL program after enabling the microcontroller for recognition of external interrupts (caused by communications with the host computer) .
MAINL, shown in Figure lOC-1, as the name suggests, is the main loop (the core of all program operations) . During its execution, it will continuously monitor system variables and current command status. Based on its findings it will force the execution of other subprograms or tasks.
SCAN, shown in Figure 10C-3, is the subprogram that deals with the actual scanning of the infrared arrays, the one that finds the user's finger, generates the corresponding set of coordinates, converts those into the proper character set, and sends the result to the host computer. Examining the flow-chart, it will be easy to find that as soon as the "activate current IR beam" takes place, the program is reading the "previous beam" (no settling time delay between activation and sensing) . If a beam is found to be blocked, then, a time delay is inserted, on purpose, to verify for the user's positive action and avoid unwanted spurious signals. CONVR, shown in Figure lOA-1, is the "blocked beams" to "real coordinates" conversion subprogram. It has embedded a number of intelligent subroutines to verify the integrity of the scan results, to generate the high-resolution virtual beams by finding the center of a large area beam-blockage and averaging the coordinates of the blocked beams, and return the result to the MAINL. The averaging technique in effect creates virtual beams between the real beams, doubling the resolution of the touch screen.
TST, shown in Figure 10A-3, is the subprogram that executes the self-test at power-up (without human intervention) and the host computer requested continuous test.
INT, shown in Figure 10C-2, is the subprogram that analyzes and processes the commands received from the host computer. DEL10, shown in Figure 10A-6, is a small time delay subroutine, used by the SCAN subprogram only when a beam is not found and also used by other time delay subroutines as a base delay.
DEL100, shown in Figure 10A-7, is a long time delay subroutine, used only by the beeper control subroutines, shown in Figures 10A-4 and 10A-5, (user audio feedback) BEEP1, BEEP2, and BEEP3.
SENDCUR (see Figures lOB-1, lOC-l and 10C-2) is a subroutine used in different subprograms to transmit the result of the current scan process to the host computer. SENDER, shown in Figure 10C-5, is a general purpose subroutine used in different subprograms to transmit any found error in communications, during the scan process, and/or while executing a test. CHERR (see Figures lOC-l and 10C-3) is a general purpose subroutine that flags a "command-error" type.
TXRDY (see Figure 10C-5) is a general purpose subroutine used by any of the serial transmitting tasks, to assure that the communications controller is free to transmit a new data character when needed.
In a preferred embodiment, the system will use a VGA video monitor display that is capable of 43 lines by 80 columns in text mode, or 640 by 480 graphic pixels. A quick overlook at the number of tasks that may be necessary to implement, using the touch-screen, shows that the user may need to be able to select single words that may appear at any position on the screen. From the graphics point of view, it is very important, that the IR-grid resolution must be an integer factor of the number of pixels in the CRT (8x10 pixels per grid) .
For these reasons, the touch-screen developed has a total resolution of 79x47 real and virtual beams that cover all possible needs, the virtual beams being created by averaging the coordinates of multiple blocked beams.
According to this embodiment, the system will provide 3840 touch points on the video screen (matrix of 79 by 47) , enabling the addressing of every character on the screen in VGA mode or even use of graphic capabilities in high resolution video mode.
Obviously, numerous and additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically claimed.

Claims

WHAT IS CLAIMED IS:
1. An infrared touch screen device that is externally adaptable to a video monitor for serving as an input device to an electronic device connected to the monitor, comprising: a bezel adapted to be releasably secured over a viewing end of a video monitor, said bezel defining an interior space through which a screen of a monitor to which said bezel is attached can be viewed; a plurality of infrared emitters disposed along said bezel to form a grid of vertical and horizontal infrared beams in said interior space when said emitters are activated; a plurality of infrared sensors disposed along said bezel, each said sensor being optically aligned with an oppositely disposed one of said emitters; activating means mounted on said bezel for activating said emitters in a predetermined sequence; scanning means mounted on said bezel for scanning said sensors in a sequence corresponding to said predetermined sequence, said sensors each producing output signals corresponding to the presence and absence, respectively, of infrared light emitted by an oppositely disposed infrared emitter; and communication means for coupling the output signals of said sensors to an input port of an electronic device connected to the monitor.
2. A device as defined in claim 1, further comprising a planar transparent screen disposed in said interior space and fastened to said bezel.
3. A device as defined in claim 2, wherein said emitters and said sensors are disposed on said bezel so that the grid of infrared beams is formed on the side of said planar transparent screen remote from the screen of a monitor to which said bezel is attached.
4. A device as defined in claim 2, wherein said planar transparent screen is sealed relative to said bezel to seal against dust, humidity and liquid.
5. A device as defined in claim 2, wherein said planar transparent screen is comprised of a polycarbonate material.
6. A device as defined in claim 5, wherein said planar transparent screen is scratch resistant.
7. A device as defined in claim 5, wherein said planar transparent screen has anti-reflective characteristics.
8. A device as defined in claim 5, wherein said planar transparent screen has anti-static characteristics.
9. A device as defined in claim 1, wherein said bezel has an inner edge surrounding said interior space and further comprising an optical filter having an infrared passband fastened to said inner edge, said emitters and said sensors each being disposed on a side of said optical filter remote from said interior space so that infrared beams emitted by respective ones of said emitters pass through said optical filter a first time prior to entering said interior space and pass through said optical filter a second time upon exiting said interior space before being received by respective ones of said sensors.
10. A device as defined in claim 1, wherein said emitters are semiconductor devices which emit infrared light when an activating current is passed therethrough, said activating means includes means for passing an activating current through respective ones of said emitters in said predetermined sequence, and the corresponding sequence by which said scanning means scans the oppositely disposed sensors lags said predetermined sequence by a predetermined time delay.
11. A device as defined in claim 10, wherein said predetermined time delay is such that when a given emitter is activated by an activating current, a sensor oppositely disposed to the emitter activated immediately preceding the given emitter is concurrently scanned.
12. A device as defined in claim 11, wherein said emitters each emit infrared light over a predetermined projection angle, and said scanning means scans said sensors so that a currently scanned sensor is outside of the projection angle of a concurrently activated emitter.
13. A device as defined in claim 1, wherein said scanning means includes processing means for converting output signals corresponding to the absence of beams to coordinates identifying the location of an object which is blocking beams in said grid.
14. A device as defined in claim 12, wherein said processing means includes averaging means for determining a coordinate at a midpoint between two adjacent blocked beams in said grid.
15. A device as defined in claim 1, further comprising storage means for storing a look-up table containing electronic addresses of said emitters and said sensors; counting means connected to said storage means for sequentially accessing said electronic addresses; first decoder means connected to said storage means for decoding the accessed electronic addresses for activating said emitters in the predetermined sequence; and second decoder means for decoding the accessed electronic addresses for scanning the sensors in the sequence corresponding to said predetermined sequence.
16. A device as defined in claim 15, wherein said activating means comprises an X-Y matrix of semiconductor drivers connected to said first decoder means, with each emitter being selectively activated according to said predetermined sequence by a unique pair of X and Y drivers.
17. A device as defined in claim 15, wherein said scanning means includes multiplexing means connected to said second decoder means for selectively reading the sensors in a mutually exclusive manner according to the sequence corresponding to the predetermined sequence.
18. An infrared touch screen for a video monitor for serving as an input device to an electronic device connected to the monitor, the monitor having a viewing screen and a bezel surrounding the screen, comprising: a plurality of infrared emitters disposed along said bezel to form a grid of vertical and horizontal infrared beams in front of the screen of the monitor when said emitters are activated by an activating current; a plurality of infrared sensors disposed along said bezel, each said sensor being optically aligned with an oppositely disposed one of said emitters; activating means for activating said emitters in a predetermined sequence, said activating means including means for passing an activating current through said emitters in said predetermined sequence; scanning means for scanning said sensors in a sequence corresponding to said predetermined sequence, said sensors each producing output signals corresponding to the presence and absence, respectively of an infrared beam emitted by an oppositely disposed infrared emitter, the corresponding sequence by which said scanning means scans the oppositely disposed sensors lagging said predetermined sequence by a predetermined time delay; and communication means for coupling the output signals of said sensors to an input of an electronic device connected to the monitor.
19. A device as defined in claim 18, wherein said predetermined time delay is such that when a given emitter is activated by an activating current, a sensor oppositely disposed to the emitter activated immediately preceding the given emitter is concurrently scanned.
20. A device as defined in claim 19, wherein said emitters each emit infrared light over a predetermined projection angle, said scanning means scans said sensors so that a currently scanned sensor is outside of the projection angle of a concurrently activated emitter.
21. A device as defined in claim 18, wherein said scanning means includes processing means for converting output signals corresponding to the absence of beams to coordinates identifying the location of an object which is blocking beams in said grid.
22. A device as defined in claim 19, wherein said processing means includes averaging means for determining a coordinate at a midpoint between two adjacent blocked beams in said grid.
23. A device as defined in claim 18, further comprising storage means for storing a look-up table containing electronic addresses of said emitters and said sensors; counting means connected to said storage means for sequentially accessing said electronic addresses; first decoder means connected to said storage means for decoding the accessed electronic addresses for activating said emitters in the predetermined sequence; and second decoder means for decoding the accessed electronic addresses for scanning the sensors in the sequence corresponding to said predetermined sequence.
24. A device as defined in claim 23, wherein said activating means comprises an X-Y matrix of semiconductor drivers connected to said first decoder means, with each emitter being selectively activated according to said predetermined sequence by a unique pair of X and Y drivers.
25. A device as defined in claim 23, wherein said scanning means includes multiplexing means connected to said second decoder means for selectively reading the sensors according to the sequence corresponding to the predetermined sequence.
26. An infrared touch screen device that is externally adaptable to a video monitor for serving as an input device to an electronic device connected to the monitor, comprising: a bezel adapted to be releasably secured over a viewing end of a video monitor, said bezel defining an opening through which a screen of a monitor to which said bezel is attached can be viewed; a planar transparent screen secured to said bezel and covering said opening; infrared beam generating means mounted on said bezel for generating a grid of infrared beams adjacent said planar transparent screen on a side of said planar transparent screen remote from a screen of a video monitor to which said bezel is to be attached; sensing means mounted on said bezel for sensing the presence and absence of respective beams in said grid and producing output signals corresponding to the presence and absence, respectively, of the infrared beams; and communication means for communicating the output signals of said sensing means to a computer connected to the monitor to which said bezel is attached.
27. The device as defined in claim 24, further comprising filter means having an infrared passband disposed in front of said sensing means for passing substantially only infrared light to said sensing means.
28. The device as defined in claim 24, wherein said infrared beam generating means comprises infrared emitters disposed along an inner edge of said bezel and said sensing means comprises infrared sensors disposed along said inner edge, each said sensor being optically aligned with a respective one of said emitters.
29. The device as defined in claim 26, wherein said infrared beam generating means includes activating means for activating said emitters in a predetermined sequence and said sensing means includes scanning means for scanning said sensors in a sequence corresponding to said predetermined sequence which lags behind said predetermined sequence so that a currently scanned sensor scans a previously activated emitter.
30. The device as defined in claim 27, wherein said emitters and said sensors are positioned on said bezel so that a currently scanned sensor receives substantially no infrared light from a currently activated emitter.
PCT/US1991/005158 1990-07-23 1991-07-22 Infrared touch screen device for a video monitor WO1992002008A1 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US55609890A 1990-07-23 1990-07-23
US556,098 1990-07-23
US07/627,229 US5162783A (en) 1990-07-23 1990-12-14 Infrared touch screen device for a video monitor
US627,229 1990-12-14

Publications (1)

Publication Number Publication Date
WO1992002008A1 true WO1992002008A1 (en) 1992-02-06

Family

ID=27071073

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1991/005158 WO1992002008A1 (en) 1990-07-23 1991-07-22 Infrared touch screen device for a video monitor

Country Status (3)

Country Link
US (1) US5162783A (en)
AU (1) AU8296991A (en)
WO (1) WO1992002008A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001057635A1 (en) * 2000-02-02 2001-08-09 Fujitsu Limited Optical position detector
CN102360255A (en) * 2011-09-22 2012-02-22 尹作恒 Infrared touch screen parallel scanning system and method for increasing infrared scanning speed without increasing peak current
US9104270B2 (en) 2006-05-22 2015-08-11 Thomson Licensing Video system having a touch screen
US9690368B2 (en) 2011-12-30 2017-06-27 Adidas Ag Customization based on physiological data
US10402879B2 (en) 2011-12-30 2019-09-03 Adidas Ag Offering a customized collection of products

Families Citing this family (102)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5497176A (en) * 1991-07-23 1996-03-05 Kabushiki Kaisha Wacom Method of transferring detailed data by tablet driver
JPH07244337A (en) * 1994-03-04 1995-09-19 Semiconductor Energy Lab Co Ltd Information input/output device
US5539201A (en) * 1994-03-14 1996-07-23 Pro-Optical Technologies, Inc. Multiple channel driver for fiber optic coupled sensors and switches
KR0170326B1 (en) * 1994-07-27 1999-03-30 김광호 Remote control method and apparatus
KR960024839A (en) * 1994-12-29 1996-07-20 김광호 Portable information terminal and information input method using soft keyboard
US5729250A (en) * 1995-05-08 1998-03-17 International Business Machines Corporation Front cover assembly for a touch sensitive device
US5768386A (en) * 1996-05-31 1998-06-16 Transaction Technology, Inc. Method and system for encrypting input from a touch screen
US5914709A (en) 1997-03-14 1999-06-22 Poa Sana, Llc User input device for a computer system
US6281880B1 (en) * 1998-06-15 2001-08-28 Vlsi Technology, Inc. Combining input/output paths for infra-red remote device inputs
US6333735B1 (en) * 1999-03-16 2001-12-25 International Business Machines Corporation Method and apparatus for mouse positioning device based on infrared light sources and detectors
JP2000348560A (en) * 1999-06-07 2000-12-15 Tokai Rika Co Ltd Determining method for touch operation position
US6396523B1 (en) 1999-07-29 2002-05-28 Interlink Electronics, Inc. Home entertainment device remote control
US6495832B1 (en) 2000-03-15 2002-12-17 Touch Controls, Inc. Photoelectric sensing array apparatus and method of using same
US6765557B1 (en) 2000-04-10 2004-07-20 Interlink Electronics, Inc. Remote control having touch pad to screen mapping
US6864882B2 (en) 2000-05-24 2005-03-08 Next Holdings Limited Protected touch panel display system
US7426695B1 (en) * 2000-06-15 2008-09-16 Hewlett-Packard Development Company, L.P. Method and apparatus for coordinating display elements with the structure of a computer system
US6690363B2 (en) 2000-06-19 2004-02-10 Next Holdings Limited Touch panel display system
US6803906B1 (en) 2000-07-05 2004-10-12 Smart Technologies, Inc. Passive touch system and method of detecting user input
WO2002009001A1 (en) 2000-07-20 2002-01-31 Citicorp Development Center, Inc. Method and system for performing a cash transaction with a self-service financial transaction terminal
CN100442207C (en) * 2000-07-24 2008-12-10 北京汇冠新技术有限公司 Infrared touch screen performance improving structure and method
US6587097B1 (en) 2000-11-28 2003-07-01 3M Innovative Properties Co. Display system
US8339379B2 (en) * 2004-04-29 2012-12-25 Neonode Inc. Light-based touch screen
US9052777B2 (en) 2001-11-02 2015-06-09 Neonode Inc. Optical elements with alternating reflective lens facets
US9778794B2 (en) * 2001-11-02 2017-10-03 Neonode Inc. Light-based touch screen
US9471170B2 (en) * 2002-11-04 2016-10-18 Neonode Inc. Light-based touch screen with shift-aligned emitter and receiver lenses
US8674966B2 (en) * 2001-11-02 2014-03-18 Neonode Inc. ASIC controller for light-based touch screen
US9052771B2 (en) * 2002-11-04 2015-06-09 Neonode Inc. Touch screen calibration and update methods
US6949297B2 (en) * 2001-11-02 2005-09-27 3M Innovative Properties Company Hybrid adhesives, articles, and methods
SE0103835L (en) * 2001-11-02 2003-05-03 Neonode Ab Touch screen realized by display unit with light transmitting and light receiving units
US6977646B1 (en) * 2001-11-30 2005-12-20 3M Innovative Properties Co. Touch screen calibration system and method
US8416217B1 (en) 2002-11-04 2013-04-09 Neonode Inc. Light-based finger gesture user interface
US8587562B2 (en) * 2002-11-04 2013-11-19 Neonode Inc. Light-based touch screen using elliptical and parabolic reflectors
US8896575B2 (en) * 2002-11-04 2014-11-25 Neonode Inc. Pressure-sensitive touch screen
US6954197B2 (en) 2002-11-15 2005-10-11 Smart Technologies Inc. Size/scale and orientation determination of a pointer in a camera-based touch system
US8403203B2 (en) * 2002-12-10 2013-03-26 Neonoda Inc. Component bonding using a capillary effect
US8902196B2 (en) * 2002-12-10 2014-12-02 Neonode Inc. Methods for determining a touch location on a touch screen
US9195344B2 (en) * 2002-12-10 2015-11-24 Neonode Inc. Optical surface using a reflected image for determining three-dimensional position information
US9389730B2 (en) * 2002-12-10 2016-07-12 Neonode Inc. Light-based touch screen using elongated light guides
US7362313B2 (en) * 2003-01-17 2008-04-22 3M Innovative Properties Company Touch simulation system and method
US6961051B2 (en) 2003-01-29 2005-11-01 Visteon Global Technologies, Inc. Cross-point matrix for infrared touchscreen
US8456447B2 (en) 2003-02-14 2013-06-04 Next Holdings Limited Touch screen signal processing
US8508508B2 (en) 2003-02-14 2013-08-13 Next Holdings Limited Touch screen signal processing with single-point calibration
US7629967B2 (en) 2003-02-14 2009-12-08 Next Holdings Limited Touch screen signal processing
US7532206B2 (en) 2003-03-11 2009-05-12 Smart Technologies Ulc System and method for differentiating between pointers used to contact touch surface
US7236161B2 (en) * 2003-03-21 2007-06-26 3M Innovative Properties Company Remote touch simulation systems and methods
US7411575B2 (en) 2003-09-16 2008-08-12 Smart Technologies Ulc Gesture recognition method and touch system incorporating the same
US7274356B2 (en) 2003-10-09 2007-09-25 Smart Technologies Inc. Apparatus for determining the location of a pointer within a region of interest
US7355593B2 (en) 2004-01-02 2008-04-08 Smart Technologies, Inc. Pointer tracking across multiple overlapping coordinate input sub-regions defining a generally contiguous input region
US7460110B2 (en) 2004-04-29 2008-12-02 Smart Technologies Ulc Dual mode touch system
US7538759B2 (en) 2004-05-07 2009-05-26 Next Holdings Limited Touch panel display system with illumination and detection provided from a single edge
US8120596B2 (en) 2004-05-21 2012-02-21 Smart Technologies Ulc Tiled touch system
US20060001654A1 (en) * 2004-06-30 2006-01-05 National Semiconductor Corporation Apparatus and method for performing data entry with light based touch screen displays
US8599140B2 (en) * 2004-11-17 2013-12-03 International Business Machines Corporation Providing a frustrated total internal reflection touch interface
US20060114245A1 (en) * 2004-12-01 2006-06-01 Masters Timothy E Touch screen cover
JP2008523424A (en) * 2004-12-09 2008-07-03 アールピーオー プロプライエタリー リミテッド Optical power distribution device
US20060285727A1 (en) * 2005-06-21 2006-12-21 International Business Machines Corporation Infrared signature capture device
US8552986B2 (en) * 2005-08-31 2013-10-08 Avago Technologies General Ip (Singapore) Pte. Ltd. Scalable controller for a computer input area
KR101160837B1 (en) * 2005-10-26 2012-06-29 삼성전자주식회사 Touch sensible display device
US20070211037A1 (en) * 2006-03-09 2007-09-13 Sun Brian Y Photoelectric sensing array apparatus
US8441467B2 (en) * 2006-08-03 2013-05-14 Perceptive Pixel Inc. Multi-touch sensing display through frustrated total internal reflection
KR20080023832A (en) * 2006-09-12 2008-03-17 삼성전자주식회사 Touch screen for mobile terminal and power saving method thereof
US20080093536A1 (en) * 2006-10-24 2008-04-24 David Campbell Brower Reduction of solar interference in an infrared touch system
US9442607B2 (en) 2006-12-04 2016-09-13 Smart Technologies Inc. Interactive input system and method
US20080136780A1 (en) * 2006-12-07 2008-06-12 Yuan-Jung Chang Method for generating a laser light detecting signal of an optical mouse
US20100026666A1 (en) * 2007-02-02 2010-02-04 Fineir Technology (Far East) Co, Infrared transmitting or receiving circuit board unit and infrared touch screen using the same
WO2008128096A2 (en) 2007-04-11 2008-10-23 Next Holdings, Inc. Touch screen system with hover and click input methods
EP2165248A4 (en) * 2007-07-06 2011-11-23 Neonode Inc Scanning of a touch screen
US8094137B2 (en) 2007-07-23 2012-01-10 Smart Technologies Ulc System and method of detecting contact on a display
EP2195726A1 (en) 2007-08-30 2010-06-16 Next Holdings, Inc. Low profile touch panel systems
AU2008280953A1 (en) 2007-08-30 2009-03-19 Next Holdings Ltd Optical touchscreen with improved illumination
US20090160823A1 (en) * 2007-12-19 2009-06-25 Shu-Fen Li Optical Contact Controlled Medium Display
US8405636B2 (en) 2008-01-07 2013-03-26 Next Holdings Limited Optical position sensing system and optical position sensor assembly
US20090213067A1 (en) * 2008-02-21 2009-08-27 International Business Machines Corporation Interacting with a computer via interaction with a projected image
US8902193B2 (en) 2008-05-09 2014-12-02 Smart Technologies Ulc Interactive input system and bezel therefor
US8676007B2 (en) 2008-06-19 2014-03-18 Neonode Inc. Light-based touch surface with curved borders and sloping bezel
KR101529916B1 (en) * 2008-09-02 2015-06-18 엘지전자 주식회사 Portable terminal
WO2010050945A1 (en) * 2008-10-30 2010-05-06 Hewlett-Packard Development Company, L.P. Object locating system with cameras attached to frame
US8339378B2 (en) 2008-11-05 2012-12-25 Smart Technologies Ulc Interactive input system with multi-angle reflector
TWM361062U (en) * 2009-01-09 2009-07-11 Quanta Comp Inc Touch screen
US8775023B2 (en) 2009-02-15 2014-07-08 Neanode Inc. Light-based touch controls on a steering wheel and dashboard
US9063614B2 (en) 2009-02-15 2015-06-23 Neonode Inc. Optical touch screens
TWI524238B (en) 2009-03-31 2016-03-01 萬國商業機器公司 Multi-touch optical touch panel
US8462276B2 (en) * 2009-07-27 2013-06-11 VIZIO Inc. System, method and apparatus for illuminating a bezel
TWI428906B (en) 2009-09-30 2014-03-01 Toshiba Global Commerce Solutions Holdings Corp Method of automatically adjusting a brightness of an optical touch panel and apparatus thereof
TWI424339B (en) * 2009-11-04 2014-01-21 Coretronic Corp Optical touch apparatus and driving mothod
US8330736B2 (en) * 2009-11-19 2012-12-11 Garmin International, Inc. Optical overlay for an electronic display
BR112012012521A2 (en) 2009-12-18 2016-04-26 Honda Motor Co Ltd methods for controlling vehicle feature control devices and their feature settings control system
CN102129327A (en) * 2010-01-20 2011-07-20 鸿友科技股份有限公司 High-efficiency infrared touch panel device
US20120105379A1 (en) * 2010-11-03 2012-05-03 Toshiba Tec Kabushiki Kaisha Coordinate recognition apparatus and coordinate recognition method
TW201303672A (en) * 2011-07-01 2013-01-16 Uc Logic Technology Corp Touch point locating method for optical touch panel and optical touch panel
CN102902422A (en) * 2012-08-30 2013-01-30 深圳市印天印象科技有限公司 Multi-point touch system and method
US10585530B2 (en) 2014-09-23 2020-03-10 Neonode Inc. Optical proximity sensor
US10282034B2 (en) 2012-10-14 2019-05-07 Neonode Inc. Touch sensitive curved and flexible displays
US9921661B2 (en) 2012-10-14 2018-03-20 Neonode Inc. Optical proximity sensor and associated user interface
US9207800B1 (en) 2014-09-23 2015-12-08 Neonode Inc. Integrated light guide and touch screen frame and multi-touch determination method
US10324565B2 (en) 2013-05-30 2019-06-18 Neonode Inc. Optical proximity sensor
US9164625B2 (en) 2012-10-14 2015-10-20 Neonode Inc. Proximity sensor for determining two-dimensional coordinates of a proximal object
US9092093B2 (en) 2012-11-27 2015-07-28 Neonode Inc. Steering wheel user interface
EP3887192B1 (en) 2018-11-28 2023-06-07 Neonode Inc. Motorist user interface sensor
WO2021138516A1 (en) 2019-12-31 2021-07-08 Neonode Inc. Contactless touch input system
CN115039063A (en) 2020-02-10 2022-09-09 平蛙实验室股份公司 Improved touch sensing device
JP2023544332A (en) 2020-09-30 2023-10-23 ネオノード インコーポレイテッド optical touch sensor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4413314A (en) * 1980-06-16 1983-11-01 Forney Engineering Company Industrial process control system
US4672558A (en) * 1984-09-25 1987-06-09 Aquila Technologies Group, Inc. Touch-sensitive data input device
US4695827A (en) * 1984-11-20 1987-09-22 Hughes Aircraft Company Electromagnetic energy interference seal for light beam touch panels
US4737631A (en) * 1985-05-17 1988-04-12 Alps Electric Co., Ltd. Filter of photoelectric touch panel with integral spherical protrusion lens
US4812830A (en) * 1986-12-08 1989-03-14 Digital Electronics Corporation Touch panel display assembly

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2567043B1 (en) * 1984-07-04 1988-05-20 Inst Francais Du Petrole PROCESS AND DEVICE FOR USE IN PARTICULAR FOR WASHING AND DESORTING SOLID PRODUCTS CONTAINING HYDROCARBONS
JPS62163138A (en) * 1986-01-13 1987-07-18 Nippon Denso Co Ltd Display switch signal generator for picture display system
US4893120A (en) * 1986-11-26 1990-01-09 Digital Electronics Corporation Touch panel using modulated light
JPS6465624A (en) * 1987-09-07 1989-03-10 Alps Electric Co Ltd Optical type coordinate input device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4413314A (en) * 1980-06-16 1983-11-01 Forney Engineering Company Industrial process control system
US4672558A (en) * 1984-09-25 1987-06-09 Aquila Technologies Group, Inc. Touch-sensitive data input device
US4695827A (en) * 1984-11-20 1987-09-22 Hughes Aircraft Company Electromagnetic energy interference seal for light beam touch panels
US4737631A (en) * 1985-05-17 1988-04-12 Alps Electric Co., Ltd. Filter of photoelectric touch panel with integral spherical protrusion lens
US4812830A (en) * 1986-12-08 1989-03-14 Digital Electronics Corporation Touch panel display assembly

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001057635A1 (en) * 2000-02-02 2001-08-09 Fujitsu Limited Optical position detector
US6627871B2 (en) 2000-02-02 2003-09-30 Fujitsu Limited Optical position detecting device having mounting member for retroreflector and optical transceiver
US9104270B2 (en) 2006-05-22 2015-08-11 Thomson Licensing Video system having a touch screen
CN102360255A (en) * 2011-09-22 2012-02-22 尹作恒 Infrared touch screen parallel scanning system and method for increasing infrared scanning speed without increasing peak current
US9690368B2 (en) 2011-12-30 2017-06-27 Adidas Ag Customization based on physiological data
US10402879B2 (en) 2011-12-30 2019-09-03 Adidas Ag Offering a customized collection of products

Also Published As

Publication number Publication date
US5162783A (en) 1992-11-10
AU8296991A (en) 1992-02-18

Similar Documents

Publication Publication Date Title
US5162783A (en) Infrared touch screen device for a video monitor
US4821030A (en) Touchscreen feedback system
US5909211A (en) Touch pad overlay driven computer system
EP0271276B1 (en) Touchscreen input validation system
KR0160801B1 (en) Computer system with touchpad support in operating system
US5550562A (en) Data processing device that enables mouse-operated application programs to be operated from an operation pad, and an operation pad for use with the same
EP0284692B1 (en) Oscilloscope with waveform selection by touch-screen
US5515079A (en) Computer input system and method of using same
US4888479A (en) Touch panel apparatus
CA2043752C (en) Method and apparatus for displaying simulated keyboards on touch-sensitive displays
US4761637A (en) Touch input device
US5148015A (en) Touch switch input device for computer system
US4672364A (en) Touch input device having power profiling
US5802544A (en) Addressing multiple removable memory modules by remapping slot addresses
US6756965B2 (en) Input device having two joysticks and touchpad with default template
EP0398055A2 (en) Flat touch screen workpad for a data processing system
US5119077A (en) Interactive ballistic tracking apparatus
US4998014A (en) Optical coordinate-input system
JP4335468B2 (en) Information input / output system, information control method, program, and recording medium
JPH096534A (en) Computer system and input device
JP3263205B2 (en) Programmable keyboard
JPS58158731A (en) Key input device
JP2001092574A (en) Screen operation system
JP6240303B2 (en) Image display device, display control program, and display control method
JPH08137599A (en) Data input device

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU CA FI JP KR US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LU NL SE

NENP Non-entry into the national phase

Ref country code: CA