|Publication number||US3911215 A|
|Publication date||Oct 7, 1975|
|Filing date||Mar 18, 1974|
|Priority date||Mar 18, 1974|
|Publication number||US 3911215 A, US 3911215A, US-A-3911215, US3911215 A, US3911215A|
|Inventors||Colwell Jr William C, Hurst George S|
|Original Assignee||Elographics Inc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (4), Referenced by (182), Classifications (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent Hurst et al.
DISCRIMINATING CONTACT SENSOR lnventors: George S. Hurst; William C.
Colwell, Jr., both of Oak Ridge, Tenn.
Assignee: Elographics, Inc., Oak Ridge, Tenn.
Filed: Mar. 18, 1974 Appl. No.: 452,784
US. Cl. 178/18; 200/86 R lnt. Cl. H01H 43/08; H04N 1/00 Field of Search 200/86 R, 153 M, 46, 159;
 References Cited UNITED STATES PATENTS 3,617,666 11/1971 Braue 200/86 R 3,632,874 1/1972 Malavard et al.. 3,668,337 6/1972 Sinclair 200/86 R 3,722,086 3/1973 Wikkerink et al. 200/86 R Primary ExaminerThomas A. Robinson Attorney, Agent, or FirmMartin J. Skinner 5 7 ABSTRACT A sensor construction is described for normally maintaining two juxtaposed electrical potential carrying sheets, at least one being flexible, separated from each other but permitting contact therebetween when an object of specified radius of curvature is pressed against the flexible sheet. The separation of the sheets is accomplished by producing discrete small buttons of insulation, preferably on the flexible sheet, with the spacing and the height of the buttons determining the largest radius of curvature to which the sensor will respond. This construction is specifically applied to a telescriber sensor or the like whereby contact is made only by depression of the flexible sheet with a writing instrument and not by any portion of a writers hand.
6 Claims, 5 Drawing Figures US. Patent 0a. 7,1975
VOLTAGE SOURCE SAMPLE AND HOLD X-ANALOG Sheet 1 0m 3,911,215
VOLTAGE 19 7 SOURCE OSCILLATOR SAMPLE AND HOLD Y-ANALOG F|G.1
(Prior Arr) US. Patent 0a. 7,1975 Sheet 2 of2 3,911,215
m x m m x x m FlG.4
DISCRINHNATING CONTACT SENSOR BACKGROUND OF THE INVENTION Our invention relates generally to the insulation of one electrical potential carrying sheet from a second such sheet except when contact therebetween is purposely desired, and more specifically to insulation means whereby the sheets are brought into contact only by an object having a radius of curvature less than a specific value, the value being established by the arrangement of the insulation. The invention is illustrated as applied to writing sensors useful for the electrographic determination of coordinates of a point or for the telemetry of drawings, signatures and the like.
Typical of the prior art in this field is found in US. Pat. No. 3,632,874 issued to L. C. Malavard et al. In that patent, and specifically FIG. 9, a conductive sheet of flexible material is separated only by an air space from a second surface or sheet to which is applied orthogonal electrical fields. A writing instrument is used to bring the sheets together and thereby generate xand y-related signals as the writing instrument is moved. However, it may be seen that finger tips, knuckles, the edge of the hand, or other objects could deform the flexible sheet and give rise to erroneous output signals.
In copending application Ser. No. 244,629, now US. Pat. No. 3,798,370, issued to G. S. Hurst on Mar. 19, 1974, a sensor is described in which a deformable insulation is utilized between a flexible conductive grounding sheet and a resistive sheet having the orthogonal electric fields. In one embodiment a gel separates the layers. Although the gel provides the necessary insulation between the sheets, it is not a practical solution for production units because of the care required to produce a reproducible characteristic. A second embodiment, in the form of a nylon net or the like, is amenable to the production of sensors and is satisfactory for many applications of the sensor. However, when handwriting is performed on the sensors fabricated using the net, the nonuniform thickness (the threads versus the knots) of even the finest available net material may be felt during the writing. Also, movement of the net between the layers gives rise to gradual deterioration of the materials in contact therewith.
SUMMARY OF THE INVENTION Our invention in its simplest form utilizes a distribution of small discrete insulating buttons of uniform height to normally separate two electrical potential carrying sheets where at least one of the sheets is flexible. The buttons may be either uniformly or randomly distributed and are preferably affixed to the flexible sheet. The spacing and height of the insulating buttons are chosen, assuming a fixed diameter, so as to prevent contact of the layers by an object having a radius of curvature greater than a selected value and thereby discriminate between objects of different radii of curvature. Specifically, the dimensions are chosen to permit contact between the layers upon deformation by a conventlonal writing instrument but prevent contact by anv part of a hand holding the writing instrument. In this structure we eliminate any physical or psychological deterrents to normal handwriting.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a simplified circuit, substantially as found in above-referenced copending application (now US. Pat. No. 3,798,370), for the purpose of permitting a description herein of one application of our invention;
FIG. 2 is an enlarged cross sectional drawing illustrating the most general form of the subject matter of our invention;
FIG. 3 is an enlarged cross sectional view of our invention when contacted by an object of less than a specified radius of curvature for a given set of parameters for the insulation;
FIG. 4 is an enlarged cross sectional view of our invention when contacted by an object of greater than a specified radius of curvature; and
FIG. 5 is an enlarged cross section drawing of an electrographic sensor embodying our invention for point coordinate determination, written telemetry and the like.
DETAILED DESCRIPTION The underlying principle of our invention may be explained through the use of FIG. 2 which shows the essential components of the sensor in an enlarged cross sectional view. Two substantially planar and parallel sheets 23, 24 are assumed to have an electrical potential applied thereto by any conventional means such as described hereinafter. Sheet 23 is flexible, so as to be deformable toward the second sheet 24 which may be rigid. Typical of the flexible material is Velostat, a conductive plastic distributed by Customs Materials, Inc., of Chelmsford, Mass, or Mylar (E. I. DuPont) with an aluminized surface as manufactured by numerous companies. The second sheet may be a conductive metal plate or, alternatively, a resistive paper supported on an appropriate backing. If a resistive sheet is utilized, a typical material is resistance paper Type L, manufactured by Knowlton Bros, Watertown, N. Y., having a resistance of 1000 to 2000 ohms per square.
Separating the sheets 23 and 24 are a plurality of distributed insulation buttons 25 preferably attached, as shown, to the flexible sheet for most applications. These buttons are of substantially equal diameter, D, and height, H, and may be randomly or uniformly distributed with a spacing, S, being either an average spacing (if random) or the actual center-to-center spacing (if uniform). The diameter, D, is very much smaller than the spacing, S. In general, a small diameter is desirable, and the height and spacing are chosen for a particular application of the layered structure. The insulating buttons 25 may be applied to sheet 23 using one of several standard techniques again depending upon the dimensions. Typical application methods are air-jet spraying, electrostatic spraying, rollers and silk screen techniques. The material utilized to form the buttons may be, for example, insulating printers ink, epoxy paint or varnish.
With the construction shown in FIG. 2, we have determined that the height and spacing (with a small fixed diameter) will affect the manner of deforming sheet 23 so as to contact sheet 24. We have developed a quantitative relationship for the condition that the two sheets can be brought into contact by pressing the flexible sheet with an object. This relationship can be expressed in terms of the radius of curvature, R, of the pressing 3 object using the equation R S /SH. An object having a radius of curvature smaller than the value of S /8H will bring about contact of the layers, as shown in FIG. 3. In contrast, an object of radius of curvature greater than S /SH will not bring about contact, as illustrated in FIG. 4.
This characteristic of discrimination by the structure as to the radius of curvature may be used, for example, to determine the number of particles of a given size range that impinge against the flexible layer 23. Thus, the structure would be used as a switch in a conventional electrical counting system. The use of several sensors each having a discrimination corresponding to different values of R would provide an electrical counting system capable of counting the number of impinging particles having various radii of curvature.
Our invention, however, is of particular value in telemetry sensors and coordinate determining sensors. Typical of such sensors is that described in the aforementioned copending patent application of G. S. Hurst. This may be understood by referring to FIG. 1 which is a schematic circuit diagram of that patent application, and to FIG. which is an enlarged cross section of a sensor embodying our present invention for use with the circuit of FIG. 1. Referring first to FIG. 1, a uniform highly resistive sheet 10 is suitably mounted by any conventional means to a support (not shown) so as to form a plane. In each comer of sheet 10 are spot electrodes 11 as at points A, B, C, and D. Spacedbetween the corner spot electrodes, in a row-like manner, are edge spot electrodes 12 along each edge of sheet 10. Three edge electrodes are shown along each edge for illustration; an actual sensor may have more or less for a particular size and application.
Connected between adjacent spopt electrodes 11 and 12 are individual discrete high precision (e.g., 0.1 to 1.0%) resistors 13. These resistors 13, in series along each edge, form four resistor networks joined to electrodes 11 at points A, B, C and D. It will be recognized that this structure, using discrete resistors, permits the choice of preferred precision resistive elements to assist in the establishment of uniform electrical gradients in the resistive paper 10.
The ends of each resistor network are connected, in an appropriate sequence, to a voltage source 18 or 19 by appropriate switches such as 14a, 14b, etc., in order to achieve orthogonal electric fields. Although a single switch across each network would function in the same manner, solid state switches required for rapid operation (e.g., 10 -10 Hz) often exhibit ohmic resistance in the closed position. However, the resistance of each of the contacts of a chip of four switches is substantially equal and thus the circuit as shown overcomes the effect of differing internal resistance. Operation of the switches l4l7 is governed by the output signals of oscillator 20.
Further details of the electrical circuit may be found in the cited copending application (now US. Pat. No. 3,798,370). The operation of the circuit results in uniform orthogonal electric fields being generated in resistive sheet 10 during mutually exclusive time periods. Accordingly, when any specific electrical potential (such as an electrical ground) is applied at a point on the resistive sheet, as by bringing sheet 23 into contact with sheet 10, output signals are produced that are related to the xand y-coordinates of the point. The coordinates are sampled at the rate of the oscillator; thus,
the coordinates of a moving point may be followed from the signals generated at the output of conventional sample-and-hold circuits 21, 22. These sampleand-hold circuits maintain the signal due to one coordinate while the other coordinate signal is being measured and then update the signal with new values.
In practice, the resistive sheet 10 is made a portion of a sensor unit such as illustrated in FIG. 5. This shows the sheet 10 and an electrode 12 mounted within a case 26. Spaced above resistive sheet 10, and parallel thereto, is the flexible conductive sheet 23 such as formed from aluminzed Mylar or the like. The flexible layer 23 is normally separated by the insulator buttons 25 from the resistive sheet 10 as described hereinabove. Placed upon the flexible sheet 23 is a protective cover sheet 27. Any conventional writing instrument 28, such as a ball-point pen or pencil, may be moved over the surface of the cover sheet 27, or another sheet (not shown) laid thereon, so as to depress the flexible sheet 23 to bring about contact with the resistive sheet 10 thus initiating electrical signals corresponding to the coordinates of the contact point.
In order that the writing instrument 28, if moved continuously on the sheet 27, will not be above an insulating button25 more than about 1% of the time, a maximum button size (diameter) of less than 0.005 in. (0.125 mm) is preferred. With this condition, the time of interruption of electrical contact between sheets 10 and 23 during continuous writing will be much less than 1%. The spacing between buttons 25 should be much greater than the diameter of the buttons and for this application may be in a range of about 0.025 to 0.075 in. (0.635 1.9 mm). The height of the buttons, if less than about 0.005 in. (0.125 mm) cannot be felt as writing occurs. In order to provide reasonable discrimination between pressure of a writing instrument and portions of a writers hand, the above-cited equation, R z 5 8H, may be used to determine the value of R for various values of separation, S, and height, H. For example, if S 0.030 in. (0.66 mm) and H 0.001 in. (0.025 mm) then R equals about 0.1 in. (2.54 mm). With S 0.050 and H= 0.002 in. (1.27 and 0.05 mm, respectively), R becomes 0.15 in. (3.8 mm). Either of these values are sufficiently small such that the portions of a writers hand will not cause contact between the flexible sheet 23 and the resistive sheet 10. However, an instrument like a ball-point pen with a radius of curvature of about 0.025 in. (0.635 mm) will readily cause contact as it moves across the surface except when over a button 1% or less of the surface). Accordingly, continuous writing may be performed with output signals being derived continuously that are proportional to the writing instrument position.
The output signals of the circuit may be utilized in many ways. For example, if the sensor is utilized for signature verification, the signals may be transmitted to a remote stationwhere a duplicate of the signature may be produced using conventional equipment (e.g., an oscilloscope). Alternatively, the signals may be compared with signals held in storage in a computer for verification of the identity.
In another utilization, data points on graphs and the like may be digitized, displayed, reproduced and/or stored. This would apply also to storage of information related to sketches of proposed design of an apparatus part, etc., until a final design is completed. Furthermore, output signals derived from data may be processed by a programmed calculator to compute desired information.
Having described several applications for our invention, it will become apparent to those versed in the art that the basic sensor has many applications. We mean, by the term basic sensor, a composite of a pair of sheets, each being capable of carrying an electrical potential and at least one being flexible, separated by small discrete buttons of insulating medium. The preferred dimensions of the insulating buttons will vary according to the utilization of our discriminating sensor. For most applications, one of the layers will be a resistive sheet in which may be established orthogonal electric fields. Although we prefer applying the present invention to the sensor of the cited copending application (now U.S. Pat. No. 3,798,370), it may be applied to sensors such as those described in US. Pat. Nos. 3,632,874, 3,449,516, 3,670,103, etc.
1. A discriminating contact sensor which will respond only toa contacting object having a radius of curvature less than a specific value, which comprises: a first sheet of a flexible material capable of being energized to establish an electrical potential thereon, a second sheet capable of being energized to establish an electrical potential thereon in juxtaposition with the first sheet, and a plurality of substantially uniform discrete insulating buttons electrically separating the first and second sheets throughout the sensor, the buttons having a height and an average spacing whereby the maximum radius of curvature of the object to which the sensor will respond is approximately equal to the square of the average spacing between the buttons divided by eight times the height of the buttons.
2. The sensor of claim 1 wherein the insulating buttons are substantially circular in a section parallel to the first and second sheets and have a diameter from about 0.001 to about 0.015 in., an average spacing between adjacent buttons of from about 0.025 to about 0.075 in. and a height in a direction perpendicular to the first and second sheets of from about 0.0005 to about 0.015 in.
3. An improved electrographic sensor for writing thereon of the type wherein a uniform resistive sheet having electrodes attached thereto for the application of orthogonal electrical potentials is overlaid with a flexible conductive sheet and spaced therefrom so as to normally prevent contact therebetween but permit contact when the flexible sheet is deformed by an object having a radius of curvature less than a specific value, wherein the improvement comprises: discrete insulator buttons of substantially uniform size electrically separating the sheets throughout the sens0r, the buttons having a height and an average spacing whereby the maximum radius of curvature of the object to which the sensor will respond is approximately equal to the square of the average spacing between the buttons divided by eight times the height of the buttons.
4. The sensor of claim 3 wherein the insulating buttons are attached to the surface of the conductive sheet.
5. The sensor of claim 3 wherein the buttons have a diameter from about 0.001 to about 0.015 in., the height thereof is from about 0.0005 to about 0.015 in., and the average spacing between the buttons is from about 0.025 to about 0.075 in.
6. The sensor of claim 3 wherein the electrodes attached to the resistive sheet are a plurality of spot electrodes equally spaced along each edge of the resistive sheet; and further comprising a plurality of discrete resistors each of which are connected between adjacent of the spot electrodes whereby a series resistor network is formed along each edge of the resistive sheet.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US3617666 *||Apr 30, 1970||Nov 2, 1971||Data Appliance Corp||Pressure-operated layered electrical switch and switch array|
|US3632874 *||Dec 29, 1969||Jan 4, 1972||Anvar||Graphic data transcription system|
|US3668337 *||Jan 18, 1971||Jun 6, 1972||Thomas & Betts Corp||Matrix switch with improved flexible insulative spacer arrangement|
|US3722086 *||Aug 21, 1970||Mar 27, 1973||Lanson Ind Inc||Process for making floor mat switches|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4035768 *||May 3, 1976||Jul 12, 1977||Veripen, Inc.||Personal identification apparatus|
|US4220815 *||Dec 4, 1978||Sep 2, 1980||Elographics, Inc.||Nonplanar transparent electrographic sensor|
|US4442317 *||Sep 14, 1981||Apr 10, 1984||Sun-Flex Company, Inc.||Coordinate sensing device|
|US4444998 *||Oct 27, 1981||Apr 24, 1984||Spectra-Symbol Corporation||Touch controlled membrane for multi axis voltage selection|
|US4456787 *||Jul 6, 1982||Jun 26, 1984||Scriptel Corporation||Electrographic system and method|
|US4463232 *||Jun 10, 1982||Jul 31, 1984||Toho- Polymer Kabushiki Kaisha||Membrane switch having spacer posts|
|US4484026 *||Mar 15, 1983||Nov 20, 1984||Koala Technologies Corporation||Touch tablet data device|
|US4493104 *||Dec 11, 1981||Jan 8, 1985||Moore Business Forms, Inc.||Character recognition device|
|US4523654 *||Sep 14, 1983||Jun 18, 1985||Scriptel Corporation||Electrographic system|
|US4529959 *||Jan 31, 1984||Jul 16, 1985||Alps Electric Co., Ltd.||Input device|
|US4550250 *||Nov 14, 1983||Oct 29, 1985||Hei, Inc.||Cordless digital graphics input device|
|US4581483 *||Mar 30, 1984||Apr 8, 1986||Koala Technologies Corporation||Interface circuitry for interconnecting touch tablet with a computer interface|
|US4600807 *||Oct 26, 1984||Jul 15, 1986||Scriptel Corporation||Electrographic apparatus|
|US4620062 *||Oct 10, 1984||Oct 28, 1986||Rdi Limited Partnership||Device for forming signals which are characteristic of the position of a point determined on a surface|
|US4631355 *||Dec 18, 1984||Dec 23, 1986||At&T Bell Laboratories||Telautograph system|
|US4636582 *||Aug 29, 1984||Jan 13, 1987||Toppan Moore Co., Ltd.||Signal input sheet having a conductive shield layer|
|US4650926 *||Jun 7, 1985||Mar 17, 1987||Scriptel Corporation||Electrographic system and method|
|US4677417 *||Dec 6, 1985||Jun 30, 1987||Alps Electric Co., Ltd.||Tablet type input device|
|US4678869 *||May 27, 1986||Jul 7, 1987||Scriptel Corporation||Position responsive apparatus, system and method having electrographic application|
|US4707570 *||Feb 12, 1986||Nov 17, 1987||Ricoh Company, Ltd.||Manual information input device|
|US4801767 *||Jun 1, 1987||Jan 31, 1989||Omron Tateisi Electronics Co.||Coordinate inputting sheet with auxiliary electrodes promoting accuracy of positional detection|
|US4801771 *||Oct 13, 1987||Jan 31, 1989||Yamaha Corporation||Force sensitive device|
|US4806709 *||May 26, 1987||Feb 21, 1989||Microtouch Systems, Inc.||Method of and apparatus for sensing the location, such as coordinates, of designated points on an electrically sensitive touch-screen surface|
|US4821029 *||Apr 26, 1984||Apr 11, 1989||Microtouch Systems, Inc.||Touch screen computer-operated video display process and apparatus|
|US4897511 *||Jun 16, 1988||Jan 30, 1990||Gunze Limited||Method of detection of the contacting position in touch panel sensor|
|US4914624 *||May 6, 1988||Apr 3, 1990||Dunthorn David I||Virtual button for touch screen|
|US4958148 *||Jan 22, 1988||Sep 18, 1990||Elmwood Sensors, Inc.||Contrast enhancing transparent touch panel device|
|US4963417 *||Jul 1, 1988||Oct 16, 1990||Toray Industries, Inc.||Pressure-sensitive tablet|
|US4990900 *||Jun 9, 1988||Feb 5, 1991||Alps Electric Co., Ltd.||Touch panel|
|US5087825 *||Feb 15, 1990||Feb 11, 1992||Nartron Corporation||Capacity responsive keyboard|
|US5153572 *||Jun 8, 1990||Oct 6, 1992||Donnelly Corporation||Touch-sensitive control circuit|
|US5157273 *||Jun 8, 1990||Oct 20, 1992||Donnelly Corporation||Modular power outlet strip|
|US5189417 *||Oct 16, 1990||Feb 23, 1993||Donnelly Corporation||Detection circuit for matrix touch pad|
|US5220136 *||Nov 26, 1991||Jun 15, 1993||Elographics, Inc.||Contact touchscreen with an improved insulated spacer arrangement|
|US5228562 *||Sep 9, 1991||Jul 20, 1993||Gm Nameplate, Inc.||Membrane switch and fabrication method|
|US5243162 *||Sep 4, 1991||Sep 7, 1993||Alps Electric Co., Ltd.||Transparent touch switch|
|US5251123 *||Aug 13, 1991||Oct 5, 1993||I C Operating, Inc.||High resolution system for sensing spatial coordinates|
|US5426732 *||Oct 5, 1994||Jun 20, 1995||International Business Machines Corporation||Method and apparatus for user control by deriving next states of a process from a current state and by providing a visual presentation of the derived next states|
|US5451724 *||Jul 30, 1993||Sep 19, 1995||Fujitsu Limited||Touch panel for detecting a coordinate of an arbitrary position where pressure is applied|
|US5530209 *||Oct 18, 1994||Jun 25, 1996||Alps Electric Co., Ltd.||Coordinate input device and method for manufacturing same|
|US5541370 *||Dec 28, 1992||Jul 30, 1996||Catalysts & Chemicals Industries Co., Ltd.||Pressure-sensitive pad and production thereof|
|US5550339 *||Oct 31, 1994||Aug 27, 1996||Cts Corporation||Variable speed tactile switch|
|US5633660 *||Apr 28, 1995||May 27, 1997||Trinitech Systems Inc.||Integrated touch screen input device|
|US5686705 *||Feb 15, 1996||Nov 11, 1997||Explore Technologies, Inc.||Surface position location system and method|
|US5711672 *||Jun 30, 1995||Jan 27, 1998||Tv Interactive Data Corporation||Method for automatically starting execution and ending execution of a process in a host device based on insertion and removal of a storage media into the host device|
|US5749735 *||Nov 3, 1995||May 12, 1998||Tv Interactive Data Corporation||Interactive book, magazine and audio/video compact disk box|
|US5757304 *||Sep 13, 1996||May 26, 1998||Tv Interactive Data Corporation||Remote control including an integrated circuit die supported by a printed publication and method for forming the remote control|
|US5788507 *||Nov 2, 1995||Aug 4, 1998||Tv Interactive Data Corporation||Method for remotely controlling a display of information from a storage media|
|US5795156 *||Nov 1, 1995||Aug 18, 1998||Tv Interactive Data Corporation||Host device equipped with means for starting a process in response to detecting insertion of a storage media|
|US5796183 *||Jan 31, 1996||Aug 18, 1998||Nartron Corporation||Capacitive responsive electronic switching circuit|
|US5815141 *||Apr 12, 1996||Sep 29, 1998||Elo Touch Systems, Inc.||Resistive touchscreen having multiple selectable regions for pressure discrimination|
|US5818430 *||Jan 24, 1997||Oct 6, 1998||C.A.M. Graphics Co., Inc.||Touch screen|
|US5839905 *||Oct 31, 1995||Nov 24, 1998||Tv Interactive Data Corporation||Remote control for indicating specific information to be displayed by a host device|
|US5877458 *||Nov 21, 1996||Mar 2, 1999||Kke/Explore Acquisition Corp.||Surface position location system and method|
|US5911582 *||Feb 5, 1996||Jun 15, 1999||Tv Interactive Data Corporation||Interactive system including a host device for displaying information remotely controlled by a remote control|
|US5957695 *||Feb 15, 1996||Sep 28, 1999||Tv Interactive Corporation||Structure and method for displaying commercials and sending purchase orders by computer|
|US6175773||Nov 23, 1998||Jan 16, 2001||Lg Electronics, Inc.||High resolution system for sensing spatial coordinates|
|US6249863||May 3, 1999||Jun 19, 2001||Tv Interactive Data Corporation||Host device equipped with means for starting a process in response to detecting insertion of a storage media|
|US6305073||Dec 29, 1999||Oct 23, 2001||Gm Nameplate, Inc.||One-sided electrode arrangement on an intermediate spacer for a touchscreen|
|US6333736||May 20, 1999||Dec 25, 2001||Electrotextiles Company Limited||Detector constructed from fabric|
|US6344623||Apr 21, 1999||Feb 5, 2002||Sumitomo Electric Industries, Ltd.||Membrane switch and production method thereof|
|US6369804||Apr 23, 1999||Apr 9, 2002||Eleksen Limited||Detector constructed from fabric having non-uniform conductivity|
|US6437258||Jul 19, 2001||Aug 20, 2002||Eleksen Limited||Detector constructed from fabric having planes with differing conductance|
|US6452479||May 4, 2000||Sep 17, 2002||Eleksen Limited||Detector contructed from fabric|
|US6477274 *||Oct 22, 1999||Nov 5, 2002||Ericsson Inc.||Handwritten character recognition devices and electronic devices incorporating same|
|US6483498||Mar 17, 1999||Nov 19, 2002||International Business Machines Corporation||Liquid crystal display with integrated resistive touch sensor|
|US6492980||Jul 19, 2001||Dec 10, 2002||Eleksen Limited||Multiplexing detector constructed from fabric|
|US6501465||Jul 19, 2001||Dec 31, 2002||Eleksen Limited||Detector constructed from fabric using measured current to determine pressure|
|US6504531||May 4, 2000||Jan 7, 2003||Eleksen Limited||Detecting mechanical interactions|
|US6639162||Mar 30, 2001||Oct 28, 2003||Electrotextiles Company Limited||Input device|
|US6650319||Mar 5, 1999||Nov 18, 2003||Elo Touchsystems, Inc.||Touch screen based topological mapping with resistance framing design|
|US6650867||Nov 16, 2001||Nov 18, 2003||Smartpaper Networks Corporation||Remote control apparatus and method of transmitting data to a host device|
|US6661405||May 19, 2000||Dec 9, 2003||Leapfrog Enterprises, Inc.||Electrographic position location apparatus and method|
|US6668156||Feb 5, 2001||Dec 23, 2003||Leapfrog Enterprises, Inc.||Print media receiving unit including platform and print media|
|US6714117||Jul 24, 2002||Mar 30, 2004||Eleksen Limited||Detector constructed from fabric|
|US6861961||Mar 30, 2001||Mar 1, 2005||Electrotextiles Company Limited||Foldable alpha numeric keyboard|
|US6926106 *||May 5, 2003||Aug 9, 2005||Invacare Corporation||Wheelchair having speed and direction control touchpad|
|US6947031||Mar 30, 2001||Sep 20, 2005||Electrotextiles Company Limited||Data processing apparatus with replacement keyboard|
|US6968151||Oct 16, 2003||Nov 22, 2005||Smartpaper Networks Corporation||Remote control|
|US6985139||Jan 5, 2004||Jan 10, 2006||Leapfrog Enterprises, Inc.||Interactive apparatus using print media|
|US7006786||Jun 4, 2003||Feb 28, 2006||Tinkers & Chance||Computer software and portable memory for an electronic educational toy|
|US7018213||Dec 29, 2003||Mar 28, 2006||Tinkers & Chance||Electronic educational toy teaching letters words, numbers and pictures|
|US7029283||Dec 29, 2003||Apr 18, 2006||Tinkers & Chance||Electronic educational toy|
|US7039355||Mar 11, 2003||May 2, 2006||Leapfrog Enterprises, Inc.||Print media receiving unit including platform and print media|
|US7040898||Dec 29, 2003||May 9, 2006||Tinkers & Chance||Computer software and portable memory for an electronic educational toy|
|US7068262||Jun 9, 2003||Jun 27, 2006||Leapfrog Enterprises, Inc.||Writing stylus for electrographic position location apparatus|
|US7102614||May 30, 2001||Sep 5, 2006||Eleksen Limited||Manual input apparatus for a handheld device|
|US7120386||Mar 11, 2003||Oct 10, 2006||Leapfrog Enterprises, Inc.||Print media receiving unit including platform and print media|
|US7139523||Mar 11, 2003||Nov 21, 2006||Leapfrog Enterprises, Inc.||Print media receiving unit including platform and print media|
|US7161084||Mar 30, 2001||Jan 9, 2007||Electrotextiles Company Limited||Detector constructed from electrically conducting fabric|
|US7203455||May 30, 2003||Apr 10, 2007||Mattel, Inc.||Interactive multi-sensory reading system electronic teaching/learning device|
|US7214066||Jan 12, 2004||May 8, 2007||Tinkers & Chance||Computer software and portable memory for an electronic educational toy having a contact sensitive display screen|
|US7217135||Jan 12, 2004||May 15, 2007||Tinkers & Chance||Electronic educational toy having a contact-sensitive display screen|
|US7265686||Jul 15, 2003||Sep 4, 2007||Tyco Electronics Corporation||Touch sensor with non-uniform resistive band|
|US7289111 *||Mar 25, 2004||Oct 30, 2007||International Business Machines Corporation||Resistive touch pad with multiple regions of sensitivity|
|US7299971||Apr 22, 2004||Nov 27, 2007||Leapfrog Enterprises, Inc.||Print media information systems and methods|
|US7365031||Apr 2, 2001||Apr 29, 2008||Intelligent Textiles Limited||Conductive pressure sensitive textile|
|US7402042||May 30, 2003||Jul 22, 2008||Mattel, Inc.||Electronic learning device for an interactive multi-sensory reading system|
|US7499036||Sep 12, 2003||Mar 3, 2009||Leapfrog Enterprises, Inc.||Electrographic position location apparatus and method|
|US7557939||Apr 22, 2004||Jul 7, 2009||Leapfrog Enterprises, Inc.||Print media information systems and methods|
|US7567242||May 23, 2007||Jul 28, 2009||Leapfrog Enterprises, Inc.||Writing stylus|
|US7800589||Dec 6, 2000||Sep 21, 2010||Tyco Electronics Corporation||Touch screen with relatively conductive grid|
|US7831933||Jan 12, 2005||Nov 9, 2010||Leapfrog Enterprises, Inc.||Method and system for implementing a user interface for a device employing written graphical elements|
|US7853193||Nov 1, 2005||Dec 14, 2010||Leapfrog Enterprises, Inc.||Method and device for audibly instructing a user to interact with a function|
|US7883420||Sep 11, 2006||Feb 8, 2011||Mattel, Inc.||Video game systems|
|US7916124||May 3, 2006||Mar 29, 2011||Leapfrog Enterprises, Inc.||Interactive apparatus using print media|
|US7922099||Dec 30, 2005||Apr 12, 2011||Leapfrog Enterprises, Inc.||System and method for associating content with an image bearing surface|
|US7936339||Nov 1, 2005||May 3, 2011||Leapfrog Enterprises, Inc.||Method and system for invoking computer functionality by interaction with dynamically generated interface regions of a writing surface|
|US7941090||Jan 16, 2004||May 10, 2011||Shoot The Moon Products Ii, Llc||Interactive book reading system using RF scanning circuit|
|US8261967||Jul 19, 2006||Sep 11, 2012||Leapfrog Enterprises, Inc.||Techniques for interactively coupling electronic content with printed media|
|US8298968||Feb 25, 2005||Oct 30, 2012||Intelligent Textiles Limited||Electrical components and circuits constructed as textiles|
|US8535153||Dec 27, 2010||Sep 17, 2013||Jonathan Bradbury||Video game system and methods of operating a video game|
|US8599143||Feb 6, 2006||Dec 3, 2013||Leapfrog Enterprises, Inc.||Switch configuration for detecting writing pressure in a writing device|
|US8669195||Sep 27, 2012||Mar 11, 2014||Intelligent Textiles Limited||Electrical components and circuits constructed as textiles|
|US8830179||Jul 13, 2007||Sep 9, 2014||Toshiba Global Commerce Solutions Holdings Corporation||Resistive touch pad with multiple regions of sensitivity|
|US8952887||Feb 27, 2009||Feb 10, 2015||Leapfrog Enterprises, Inc.||Interactive references to related application|
|US9652122||Feb 20, 2015||May 16, 2017||Qualcomm Incorporated||Technique for enabling multiple actions to be performed on an active data item|
|US9652123||Feb 20, 2015||May 16, 2017||Qualcomm Incorporated||Technique for enabling multiple actions to be performed on an active data item|
|US9703395||Mar 24, 2015||Jul 11, 2017||Korea Advanced Institute Of Science & Technology (Kaist)||System and method for detecting interpersonal touch using electrical properties of skin|
|US9731208||Jan 9, 2009||Aug 15, 2017||Mattel, Inc.||Methods of playing video games|
|US20020134116 *||Mar 30, 2001||Sep 26, 2002||Sandbach David Lee||Detector constructed from electrically conducting fabric|
|US20020135457 *||May 30, 2001||Sep 26, 2002||Sandbach David Lee||Foldable alpha numeric keyboard|
|US20030011576 *||Mar 30, 2001||Jan 16, 2003||Sandbach David Lee||Data processing apparatus with replacement keyboard|
|US20030119391 *||Apr 2, 2001||Jun 26, 2003||Swallow Staley Shigezo||Conductive pressure sensitive textile|
|US20030146902 *||May 30, 2001||Aug 7, 2003||Sandbach David Lee||Manual input apparatus and processor|
|US20030192728 *||May 5, 2003||Oct 16, 2003||Richey Joseph B.||Wheelchair having speed and direction control touchpad|
|US20030198928 *||Mar 11, 2003||Oct 23, 2003||Leapfrog Enterprises, Inc.||Print media receiving unit including platform and print media|
|US20040043365 *||May 30, 2003||Mar 4, 2004||Mattel, Inc.||Electronic learning device for an interactive multi-sensory reading system|
|US20040043371 *||May 30, 2003||Mar 4, 2004||Ernst Stephen M.||Interactive multi-sensory reading system electronic teaching/learning device|
|US20040063078 *||Jun 4, 2003||Apr 1, 2004||Marcus Brian I.||Electronic educational toy appliance|
|US20040070192 *||May 30, 2003||Apr 15, 2004||Miriam Kelley||Book/clipped container combination|
|US20040076935 *||May 30, 2003||Apr 22, 2004||Mattel, Inc.||Method for teaching linguistics|
|US20040086840 *||Oct 16, 2003||May 6, 2004||Redford Peter M.||Method of detachably attaching an insert to a remote control base and the resulting remot control|
|US20040104890 *||Sep 3, 2003||Jun 3, 2004||Leapfrog Enterprises, Inc.||Compact book and apparatus using print media|
|US20040140966 *||Jan 5, 2004||Jul 22, 2004||Leapfrog Enterprises, Inc.||Interactive apparatus using print media|
|US20040142308 *||Dec 29, 2003||Jul 22, 2004||Marcus Brian I.||Electronic educational toy appliance having a touch sensitive surface|
|US20040142309 *||Dec 29, 2003||Jul 22, 2004||Marcus Brian I.||Computer software and portable memory for an electronic educational toy having a touch sensitive surface|
|US20040142310 *||Dec 29, 2003||Jul 22, 2004||Marcus Brian I.||Electronic educational toy appliance having a touch sensitive surface teaching letters words and numbers|
|US20040142311 *||Jan 12, 2004||Jul 22, 2004||Marcus Brian I.||Computer software and portable memory for an electronic educational toy having a contact sensitive display screen|
|US20040146843 *||Jan 12, 2004||Jul 29, 2004||Marcus Brian I.||Electronic educational toy having a contact-sensitive display screen|
|US20040146844 *||Jan 12, 2004||Jul 29, 2004||Marcus Brian I.||Electronic educational toy having a contact-sensitive display screen|
|US20040213140 *||Jan 29, 2004||Oct 28, 2004||Taylor John W.||Interactive electronic device with optical page identification system|
|US20040219495 *||Jun 7, 2004||Nov 4, 2004||Marcus Brian I.||Method and apparatus for promoting alphabetic and mathematic learning using a computerized educational toy appliance|
|US20040219501 *||Jan 16, 2004||Nov 4, 2004||Shoot The Moon Products Ii, Llc Et Al.||Interactive book reading system using RF scanning circuit|
|US20040246211 *||Jun 9, 2003||Dec 9, 2004||Leapfrog Enterprises, Inc.||Writing stylus for electrographic position location apparatus|
|US20050012644 *||Jul 15, 2003||Jan 20, 2005||Hurst G. Samuel||Touch sensor with non-uniform resistive band|
|US20050082359 *||Apr 22, 2004||Apr 21, 2005||James Marggraff||Print media information systems and methods|
|US20050212773 *||Mar 25, 2004||Sep 29, 2005||Asbill Roger L||Resistive touch pad with multiple regions of sensitivity|
|US20050219591 *||Apr 22, 2004||Oct 6, 2005||James Marggraff||Print media information systems and methods|
|US20050255435 *||Jul 25, 2005||Nov 17, 2005||Redford Peter M||Insert for use with a remote control base|
|US20050259083 *||Sep 12, 2003||Nov 24, 2005||Mark Flowers||Electrographic position location apparatus and method|
|US20050260338 *||May 19, 2004||Nov 24, 2005||Trendon Touch Technology Corp.||Method of manufacturing circuit layout on touch panel by utilizing metal plating technology|
|US20060080609 *||Nov 1, 2005||Apr 13, 2006||James Marggraff||Method and device for audibly instructing a user to interact with a function|
|US20070009866 *||Jun 13, 2006||Jan 11, 2007||Tinkers & Chance||Interactive activity system having a first display screen and a second contact sensitive display screen and portable memory therefor|
|US20070097100 *||Nov 1, 2005||May 3, 2007||James Marggraff||Method and system for invoking computer functionality by interaction with dynamically generated interface regions of a writing surface|
|US20070190511 *||Apr 9, 2007||Aug 16, 2007||Mattel, Inc.||Interactive Multi-Sensory Reading System Electronic Teaching/Learning Device|
|US20080007537 *||Jul 13, 2007||Jan 10, 2008||Asbill Roger L||Resistive touch pad with multiple regions of sensitivity|
|US20080043001 *||May 23, 2007||Feb 21, 2008||Michael Perkins||Writing stylus|
|US20080088601 *||Dec 14, 2007||Apr 17, 2008||Tpk Touch Solutions Inc.||Circuit layout on a touch panel|
|US20080233822 *||Feb 25, 2005||Sep 25, 2008||Stanley Shigezo Swallow||Electrical Components and Circuits Constructed as Textiles|
|US20090091488 *||Sep 29, 2008||Apr 9, 2009||Shigeru Shibutani||Input device and remote-control transmitter using the same|
|US20140346936 *||Apr 8, 2014||Nov 27, 2014||Samsung Electronics Co., Ltd.||Protection cover|
|US20150125829 *||Dec 29, 2014||May 7, 2015||Sydney Hyman||Image making medium compositions and images|
|USRE38286||Feb 28, 2001||Oct 28, 2003||Leapfrog Enterprises, Inc.||Surface position location system and method|
|USRE39881||Sep 18, 2003||Oct 16, 2007||Leapfrog Enterprises, Inc.||Surface position location system and method|
|EP0054406A1 *||Dec 9, 1981||Jun 23, 1982||Moore Business Forms, Inc.||Writing pad for a character recognition device|
|EP0145651A2 *||Oct 9, 1984||Jun 19, 1985||Battelle Memorial Institute||Device for forming signals characteristic of the position of a predetermined point on a surface|
|EP0145651A3 *||Oct 9, 1984||Jul 10, 1985||Battelle Memorial Institute||Device for forming signals characteristic of the position of a predetermined point on a surface|
|EP0194861A2 *||Mar 11, 1986||Sep 17, 1986||Elographics, Inc.||Electrographic touch sensor with z-axis capability|
|EP0194861A3 *||Mar 11, 1986||Sep 21, 1988||Elographics, Inc.||Electrographic touch sensor with z-axis capability|
|EP0210063A2 *||Jul 18, 1986||Jan 28, 1987||Elographics, Inc.||Fabric touch sensor & method of manufacture|
|EP0210063A3 *||Jul 18, 1986||Nov 17, 1988||Elographics, Inc.||Fabric touch sensor & method of manufacture|
|EP0301842A2 *||Jul 27, 1988||Feb 1, 1989||Toppan Moore Company, Ltd.||Information input sheet|
|EP0301842A3 *||Jul 27, 1988||May 2, 1990||Toppan Moore Company, Ltd.||Information input sheet information input sheet|
|EP0419145A1 *||Sep 14, 1990||Mar 27, 1991||Psion Plc||Input device|
|EP0625789A1 *||Dec 28, 1992||Nov 23, 1994||CATALYSTS & CHEMICALS INDUSTRIES CO., LTD.||Writing pad and production thereof|
|EP0625789A4 *||Dec 28, 1992||Aug 6, 1997||Catalysts & Chem Ind Co||Writing pad and production thereof.|
|WO1989000442A1 *||Jul 4, 1988||Jan 26, 1989||Wolfgang Hentschel||Electric monitoring of surfaces, in particular the boundary surfaces of sports grounds|
|WO1994018664A1 *||Feb 14, 1994||Aug 18, 1994||Trinitech Systems Inc.||An integrated touch screen input device|
|WO1997030429A1 *||Feb 11, 1997||Aug 21, 1997||Explore Technologies Inc.||Surface position location system and method|
|WO2000002217A1 *||Apr 21, 1999||Jan 13, 2000||Sumitomo Electric Industries, Ltd.||Membrane switch and production method thereof|
|WO2005010804A1 *||Jun 25, 2004||Feb 3, 2005||Elo Touchsystems, Inc.||Touch sensor with non-uniform resistive band|
|U.S. Classification||178/18.5, 200/86.00R|
|International Classification||G06F3/045, G06F3/033, G06F3/041|