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Publication numberUS3697687 A
Publication typeGrant
Publication dateOct 10, 1972
Filing dateDec 16, 1970
Priority dateDec 16, 1970
Publication numberUS 3697687 A, US 3697687A, US-A-3697687, US3697687 A, US3697687A
InventorsLarson Harry T, Loewe Richard T
Original AssigneeLarson Harry T, Loewe Richard T
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Encoding device
US 3697687 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Larson et al.

[451 Oct. 10,1972

I54] ENCODING DEVICE [22] Filed: Dec. 16, 1970 [21] Appl. No.: 98,551

[52] US. Cl ..l78/l8 [51] int. Cl. ..H04n 1/00 [58] Field of Search ..l78/l8, i9, 20, 26 A; 340/324 A, 166 EL, 365

[56] References Cited UNITED STATES PATENTS 3,466,646 9/ l 969 Lewin ..178/l8 3,522,664 8/ I970 Lambright et al. 1 78/18 3,423,528 l/l969 Bradshaw et al. ..178/l9 OTHER PUBLICATIONS Montedonico, IBM Technical Disclosure Bulletin, Vol. 1 I, No. 12, May i969, Self-Adjusting Swivel Tip for Light Pen.

Primary Examiner-Kathleen H. Clafi'y Assistant Examiner-Horst F. Brauner Attorney-Fowler, Knobbe & Martens ABSTRACT A device for digitally encoding the position of a selected point location, the device comprising a foundation member having at each of a plurality of point locations a unique combination of conductive members, not necessarily exposed representing a code combination of the elements of a code system, such as a binary code. At least one probe in the form of an electrode is arranged to be brought into registry and proximity but not into actual contact with the conductive members at an assigned one or any of a plurality of the point locations of the combination of members. All of the conductive members that pertain to the same element level of the code are connected together and to a register or other utilization device. Following the positioning of the probe it is energized to impress an electrostatic charge on those of the conductive members with which it is in registry. The utilization devices respond to these charges, and thus a discrete code combination is generated.

35 Chins, 11 Drawing Figures OUTPUT P'ATENTEnum 10 m2 SHEET 2 UF 5 OUTPUT 0N (00E L/NES INVENTORS.

BY19/0 1 /4190 7.' L 05/4 11 Fan 451?, 44/0555 5 MAP TENS ATTOP/VEJ J'.

ENCODING DEVICE BACKGROUND OF THE INVENTION The most commonly used encoding devices are and have for many years been keyboard mechanisms used in such devices as keypunch devices and teletypewriters. Such devices are most useful when operated by skilled persons employing so-called touch keyboard techniques. They are, however, slow and inefficient devices in the hands of unskilled personnel.

For entering words, phrases, paragraphs, groups of numerical digits, or groups of any symbols, operators using keyboards require a separate keystroke for each character or symbol, and are error-prone, slow and inefficient. Similar difficulties are encountered when entering by means of a keyboard data basically represented in scalar form, two-dimensional graphical form or in three-dimensional form.

Devices that are more convenient than keyboards are those having a single encoding element to be moved from place to place relative to a surface, for generating codes representing data. The approach to manually positioned, single encoding elements probably began with the use of light guns in connection with displays on cathode ray tubes. From this, there evolved light buttons to provide more flexibility than an array of push buttons.

Another approach to encoding came in the form of the variable function keyboard. These keyboards introduced the concept of keyboard overlays, to change the designators identifying the functions of push button sets.

Both the light gun concept and the variable function keyboard concept have deficiencies. The light gun requires substantial quantities of complex equipment. The variable function keyboards have a limited number of keys and very little space for displaying interchangeable sets of key designators.

The Rand tablet, in which a probe or stylus derives signals at points of intersection of conductive lines extending in X and Y coordinate directions, and other devices employing inverse plotter techniques, have also been used in variable function data generating applications. The problems with inverse plotter techniques are equipment complexity and the X, Y coordinate output. The X, Y coordinate output complicates the computer programs by requiring an extra translation from X, Y to the code used in the program.

The expanding field of computer applications and time sharing systems has generated a great need for a simple, inexpensive computer input device that is easy for even unskilled operators to use. The existing devices and techniques have not met the needs because of cost and complexity, limited numbers of keys in the case of keyboards, and programming complexities.

BRIEF DESCRIPTION OF THE INVENTION In accordance with the present invention, the encoding of data directly into binary codes is accomplished by means of a free probe that is hand-held in generally the same manner as a writing instrument and may be moved directly from point to point on a display sheet carrying visible indicia of the intelligence that may be encoded, and visible markers showing the points at which the probe is to be presented to effect the encoding of the intelligence.

Briefly, the encoding device comprises, in addition to the probe, a panel on which there are a plurality of conductor members of segments arranged so that the conductors that appear in various point locations define code combinations of a binary code. An exemplifying pattern of conductors used herein for illustrating a panel comprises one or more columns of combinations of conductor segments so arranged that the column comprises a plurality of transverse combinations of conductor segments respectively small encoding areas at specified point locations in accordance with a binary code. Each column may contain as a maximum a full complement of the code combinations of a particular multi-element code, for example, a five element code which afi'ords a maximum of 32 unique code combinations. More generally a code of n elements affords a maximum of 2" unique binary code combinations. The presence of a conductor in an encoding area may represent a "l" and the absence of a conductor may represent a 0" or vice versa. Half of the occurrences of code elements in a binary code system are 1's and the other half are Os, when a full complement of code combinations is used. Thus for each element of the code, 2'12 of the encoding areas will have conductors present and 2"/2 of the encoding areas will lack conductors representing that code element. The probe has a conductive tip dimensioned so that it may span the conductive segments at an encoding point location and register with any one of the unique combinations of conductor segments without overlapping adjacent code combinations in the column. The panel may be provided with several groups or columns of the conductor segments which may be alike insofar as the basic encoding system for the point locations in the column is concerned. The columns in turn may be distinguished from one another in the encoding process by the addition thereto of one or more conductors which become common to all of the code combinations in any column, but which are unique as between columns in the same way that the encoding code combinations for the point locations in a column are unique relative to one another. In this way, in addition to the intelligence identifying code combinations for the encoding point locations in the column, the column identifying code combinations are added to the encoding areas, so that each encoding point location on the panel is identified by a unique binary code.

For use with the panel an overlay is provided in the form of a sheet on which appear, preferably in printed form, the items of intelligence that may be encoded, and markers corresponding to the encoding positions of the point locations on the columns. Proper registration of the markers on the overlay with the conductive components on the panel may be effected by providing the panel with locating pins and the overlay with perforations, or by providing any functionally equivalent means for registration. Either the overlay or a protective dielectric coating may serve the purpose of precluding physical contact between the probe tip and the conductor segments.

In any column all of the conductor segments pertaining to one of the elements of the code are connected together and to an output conductor with which is associated a register device such as a flip-flop. Corresponding code element output conductors of the several columns are connected together and to the same register device. The conductors designating the columns are connected in unique combinational patterns to other output conductors, and a register device is associated with each of these output conductors. If m output conductors represent code elements identifying the columns and if up to m column identifying conduc tors appear in every encoding area in a column then up to 2" columns can be distinguished by the resulting codes. Similarly if a maximum of ml column identifying conductors appear in each encoding area in a column then a maximum of 2"l columns can be distinguished from one another since, in a code of binary code combinations, only one of those code combinations has the value l or the value in all positions. Furthennore, if there are n code elements representing the different encoding areas within a column, and m code elements representing the different columns of encoding areas, then a maximum of 2"" different encoding areas may be distinguished from one another by the encoding device. Additionally, there is provided an electrical pulsing or signal generating device that is electrically associated with the probe. Also associated with the probe is a switch device which when operated, following the presentation of the probe to a selected marker point on the overlay, activates the pulsing device to cause the probe to be pulsed. Because the probe is held out of contact with the conductive elements of the panel by the protective coating or the overlay or both, an electrostatic charge is impressed by the tip of the probe upon those of the conductor segments with which it is in registry, and the resulting code combination will appear at the corresponding combina' tion of the register devices and may be utilized in any data system, in a bit parallel or bit sequential manner.

Instead of employing an overlay, the panel that supports the conductor segments and the conductor segments themselves may be transparent and the information displayed as previously described on the overlay may appear behind or beneath the panel, and may be viewed through the panel. The overlay or underlay may be a diagram, a chart or a map, alphanumerics, words, phrases, or paragraphs. It may even be an image projected on an opposite face of the panel from the face to which the probe is to be applied.

DESCRIPTION OF THE DRAWINGS For a more complete understanding of the invention, reference may be had to the following detailed description, to be interpreted in the light of the accompanying drawings wherein:

FIG. I is a plan view in schematic but not-to-scale format showing an encoding panel in accordance with the present invention;

FIG. 2 is a horizontally expanded schematic view showing in detail a typical arrangement of encoding conductor segments for any one of the several encoding columns of FIG. 1;

FIG. 3 is a greatly enlarged cross-sectional view taken on the line 3-3 of FIG. I at a point corresponding to the binary code value 27 as shown in FIG. 2, and including a fragment of the probe tip approaching presentation;

FIG. 4 is a schematic view showing in cross-section an energy transferring probe to be used with the panel shown in FIG. I;

FIG. 5 is a schematic view showing electrical components that may cooperate with the panel and probe, and the circuit relationships;

FIG. 6 is an exploded view showing the encoding panel and an overlay which carries indicia representing intelligence to be encoded;

FIG. 7 is a view similar to FIG. 6 showing an embodiment in which the information can'ied by the overlay in FIG. 4 is displayed beneath a transparent panel for viewing through the panel;

FIG. 8 is a schematic view showing an encoding panel associated with the face ofa cathode ray tube;

FIG. 9 is a fragmentary showing of a keyboard encoding device employing encoding components comparable with the panel and hand-held probe;

FIG. 10 is an enlarged plan view ofa fragrnental portion of an encoding panel in magnified form showing, to the same scale, encoding conductor segment and output conductor spacing, encoded point location size and overlay indicia size; and

FIG. II is a further enlarged plan view of a fragmental portion of an encoding panel showing in greater magnified form and to scale relatively the size of encoded point locations, the size of conductor segments and termini thereof relative to encoded point locations, the probe tip size and range of positioning thereof, and overlay indicia.

DETAILED DESCRIPTION Referring to the drawings and particularly to FIG. 2, the reference numeral II designates in common a plurality of conductor segments. The segments are grouped into a columnar form as shown at the left of FIG. 2 and are of various lengths and patterns of discontinuities in accordance with a multi-element binary code. They may be considered as being comprised of seven sets positioned side-by-side and together forming a column, each set, whether broken or unbroken, being one electrical entity, and in the case of discontinuities, the segments representing any one code element or level are arranged to be connected together and to output conductors. The sets are identified by designations 0, I, 2,3, 4, 5, and 6, and by reference numerals II-0, lI-I, 11-2, "-3, "-4, "-5 and 11-6, and the sets which together make up a binary code may be considered as forming a group.

At the right of FIG. 2 is a table of the various code combinations of the binary values 0 and l ofa five-element binary code in which the least significant bit of each code combination is designated as position 0, the next most significant bit is designated I and the remaining bit positions are designated 2, 3 and 4 and these correspond to the designations supplementary to the reference numeral II, of the sets of conductor segments. It will be noted that there is a conductor segment lhO opposite each code combination that has the binary value I in the least significant or 0 position. Similarly, there is a conductor segment ll-l opposite each position that has a binary value I in the next code position of the code, designated I. Each of the conductor segments and intervening discontinuities of a set may be considered as comprised of one or more equal subdivisional units of length, in which a subdivisional unit of length is the extent of that fractional portion ofa conductor segment or discontinuity that is a part of any code combination of conductor segments and discontinuities. The foregoing generally describes the spacial relationships appearing in FIG. 2 but a different set of spacial relationships is shown in FIG. 11, as will be described hereinafter. A five-element binary code atfords a maximum of 32 unique combinations of elements and 30 of these are shown in FIG. 2. The combinations not shown and which are sometimes employed for special purposes, are the combination having the binary value 0 in all five positions and the combination having the binary value l in all five positions. In the encoding panel embodiment shown and described herein, the function of the additional conductor segments 11-5 and 11-6 is to identify columns, as will be described hereinafter. The particular code arrangement of conductor segments in this embodiment was selected to minimize the number of wire crossings. If the panel is made by printed circuit techniques, as will be more fully set forth hereinafter, this constraint is easily eliminated by the use of plating-through techniques in printed wiring, to provide the wire crossings on the opposite side of the substrate from the encoding conductor segments.

In FIG. 2 a broken lined rectangle 12 has been shown enclosing the point location encoding conductor segments 11 and the output leads and interconnection paths that parallel the segments 11 are outside this rectangle, the connections to all of the conductor segments except 11-4, 11-5 and 11-6 being brought out laterally from the area enclosed in the rectangle 12. With the arrangement of conductor segments inside the rectangle 12 in FIG. 2 a conductive probe tip having a transverse dimension matching the horizontal expansion of the column in FIG. 2, and placed upon the pattern at various encoding points, in alignment with the binary values listed at the right of FIG. 2, will register with one or more encoding conductor segments in ac cordance with the patterns of the occurrence of the binary value l in the listing of the code combinations. The portions of the output conductors outside the rectangle l2 are sufficiently remote from the encoding conductor segments that the probe tip, when positioned to span the conductor segments at the encoding points, cannot overlie any output conductor portion. The connections extending laterally outwardly from the conductor segments within the rectangle 12 to the output conductors have been brought out in such locations that if the probe tip is actually in registration with the rectangle I2 and such a connection, it is also in registration with the segment with which the connection is associated, and errors in encoding cannot result.

FIG. shows in enlarged form, by comparison with the actual dimensions of one embodiment of the invention, parts of two columns of conductor segments in realistic relation of lateral spacing between the conductor segments of a column and between some of the conductor segments and their output conductors. In order to relate FIG. 10 to FIG. 2 the binary code values of various encoding point locations have been shown. In addition, squares 52 have been superimposed upon the columns of conductor segments to indicate the encoding point locations. It will be noted that the dimension of the squares is slightly greater than the distance across the column from the outermost conductor segment on one side to the outermost conductor segment on the other side. Thus each square establishes a location containing the conductor segments for encoding that point location. This shows that a probe tip spanning one point location is adequately separated from the neighboring point locations in the column so that errors in encoding cannot result. It also indicates the wide separation of the paralleling output conductors from the encoded point locations. It will be understood that a structure embodying encoding conductor segments may or may not display squares 52, but if it does not it will probably be desirable that some type of visible markers, such as the dashes 14, be provided for showing the encoding point locations. The markers 14 have been shown in FIG. 10 as dashes, but they might be dots or any other desired configuration. The informative material appearing in dotted line form opposite the encoding point locations is representative of information which might appear on an overlay to be associated with columns of encoding conductor segments as will be described hereinafter.

FIG. 11 shows in still greater magnification than FIG. 10 the encoding conductor segments of a part of one of the columns of FIG. 10, together with the squares S2 locating encoding points and, in dotted form, represem tations of the associated information. The encoding conductor segments, the squares and the letters included in the information display are shown in substantially the same scale which, it is repeated, is greatly enlarged. In accordance with one embodiment of the invention it is contemplated that the conductor segments shall have a width of about 0.004 inch and the spacing between adjacent segments laterally is about 0.003 inch. Thus the width of a column is approximately 0.050 inch and the point locations are considered to be squares 0.050 X 0.050 of an inch. As indicated in FIG. 11 the terminations of encoding conductor segments substantially coincide with the edges of the squares representing encoding point locations, so that all conductor segments that enter an encoding point location square extend at least fully across that square.

It is contemplated that the spacing of successive encoding points in a column may conveniently be onesixth inch which is the standard line spacing on a typewriter. This will permit overlays or master copies thereof to be prepared on a typewriter. The decimal equivalent of one-sixth inch is 0.166 inch, which is more than three times the width of the column of conductor segments. Ease of manipulation of the probe can be enhanced by making the dimension of the probe tip, both vertically and laterally of the column, of the order of 0.125 inch. Moreover, ease of manipulation will further be enhanced by making the probe tip face circular, thereby eliminating restrictions as to orientation of the probe tip relative to the column of conductor segments. In FIG. 11 the dot-dash lined circles 53 represent several of the many possible positions that a circular probe of the above mentioned dimension may occupy, in exact registration with an encoding point location 52 and in misalignments relative to the location, which will produce a proper encoding and at the same time will not encroach on neighboring locations. The squares in FIGS. 10 and 11 may be considered as representing the target point locations for the probe, and as squares or in some other fonn would be printed on the overlay.

Referring now to FIG. I, the reference numeral 16 designates a panel which carries a plurality of sets or columns of conductor segments, each occurrence comparable although not necessarily identical in pattern with the showing in FIG. 2, and the area allocated to each column of segments and its interconnecting and output conductors is represented by a rectangle 13. Seven such columns have been indicated. The output conductors of the seven columns of conductor segments carried by the panel 16 are connected to corresponding common output conductors designated 111-0, 111-1, 111-2, Ill-3 and 111-4 for the conductor segments "-0, 11-1, 11-2, "-3 and 11-4 respectively, and Ill-A, Ill-B and 111C for the two conductor segments "-5 and 11-6 which are connected to identify the seven columns, as will be described hereinafter.

FIG. 3 shows a cross-section of the panel 16 at one of its columns of conductor segments. In accordance with the preferred embodiment of the invention, the panel is comprised ofa dielectric substrate 18 on which the encoding conductor segments 11 in the desired patterns are carried, typically produced by printed wiring board techniques. In FIG. 3 the cross-sectional appearances of the conductor segments correspond with the pattern of segments opposite the binary code value 27 in FIGS. 2, l0 and 11.

For reasons which will be set forth hereinafter the probe tip that cooperates with the conductor segments preferably does not actually contact them, and such contact may be prevented by a protective wear coating l9 which may cover the conductor segments, or by an overlay 41, the function of which will also be described hereinafter, or both. There is further associated with the dielectric substrate [8 an electrically conductive ground plane 21 which will become a part of the electric circuit and accordingly is substantially coextensive with the area of the panel 16.

Ifa protective wear coating is provided there may be printed, on its surface, markers identifying the encoded point locations. These may be imprinted by silk screen process or other printing techniques such as those typically employed in printed circuit board fabrication for identifying components, locations and like legends. Such imprinting would be superimposed on the areas delineated by the squares 52in FIGS. and 11.

A probe for generating binary code combinations in cooperation with the panel 16 is shown in FIG. 4 and is designated by the reference numeral 26. It resembles in shape and dimensions a stylus or other writing instrument that may be comfortably held in the hand of the user. The probe 26 is comprised of a barrel 25 which may include a metallic shield to prevent stray radiation and a metallic tip 27 preferably pivotally associated with the barrel as by means ofa ball and socket connec tion 28. With this articulation of the conductive tip 27 to the barrel 25, the tip 27 may be presented flat against the surface of the panel l6, as represented by the protective coating l9, irrespective of the angle of presentation of the hand-held barrel, within certain limits. The probe 26 includes a switch 29 for activating a circuit, represented in the probe by conductors 31 and 32. The switch 29 may be provided with an operating button 33 projecting from the barrel ofthc probe in a position such that it may be pressed by a finger of the user to effect the operation of the switch. Alternatively, it can be associated mechanically with a yielding support for the tip 27 whereby the exertion of pressure following the presentation of the electrode 27 to the panel 16 will result in operation of the switch 29. Altematively, the equivalent switch action may be achieved by actuation remotely from the probe, such as by a foot switch, or by actuators associated with the panel. The tip 27 also has connected to it a conductor 34 by which it may be made a part of the electrical circuitry of the encoding device.

FIG. 5 shows schematically the electrical circuitry by means of which the generation of binary codes through the cooperation of the probe 26 with the conductor segments is accomplished. The conductor 34 connects the tip 27 of the probe to a pulse or signal generator 36. The nature of the signals will be described hereinafter. Conductors 31 and 32 are also connected to the signal generator 36 and serve to activate the generator, upon the activation of the switch 29 to cause the pulsing of the tip 27. The conductors 31, 32 and 34 may be included in a flexible cable 35 (FIGS. 6 and 7). The pulse generator may be embodied within the probe 26, or be associated with the probe by some other means to supply the necessary electrostatic energy to the probe tip 27. The output conductors that are common to all of the encoding conductor segments on the panel 16 are shown in FIG. 5 as having individual resistive connections 40 to ground and also as being connected individually to the input terminals of amplifiers 37 represented in the conventional manner. The output of each amplifier 37 is connected to a storage register 38. Preferably the registers 38 are two state storage devices which may have either one or two stable states, depending upon the preferred mode of operation of the system. If they are bi-stable devices, such as flip-flops, it is necessary to provide a reset control to be operated by the operator or other instrumentality before the next encoding operation of the device. The register devices may instead be monostable devices which are selfresetting after an interval determined by circuit parameters, and the self-resetting would be arranged to occur after the utilization of the conditions stored in the registers, in whatever manner is desired. The register 38 may also take the form of other temporary storage devices, such as capacitors.

No specific arrangement for utilizing the codes has been shown in the drawings. It will be understood that they may operate a code storing device such as a magnetic tape recorder or a paper tape punch, they may be applied as inputs to a digital computer or any data processing device, or they may be impressed upon a communication channel in bit-sequential mode by means of a serializer, such as a shift register arranged for parallel input and sequential output.

If verification by an operator becomes important, a lamp display board having a decoding matrix or fan driven by the registers 38 may be provided for lighting lamps individual to the code combinations. The am plifiers 37 or registers 38 may be employed to drive any suitable means to verify that an input has taken place.

lfdesired, a lamp 39 may be associated with each re gister 38 to light when the register is in the activated condition and display to the operator the code combination that has been generated by means of the probe. Operators can check the accuracy of their actions by observing lamps that represent the code bits. If the operator does not know the code assignments, the lighting of at least one lamp indicates that a code has been stored.

As indicated in FIG. 2, the conductor segments 11-5 and 11-6 are coextensive with all of the other conductor segments 11 and have no interruptions. Thus, either or both, if connected by an output conductor to a register device 38, will add one or two code elements having the binary value 1 to each of the five level code combinations available in a column of conductor segments. Each column of the seven shown in FIG. 1 duplicates, in the conductor segments 1 1-0, 11-1, 11-2, 11-3 and 11-4, the five-level code combinations that are available in all other columns, whether or not the code combinations are in the same sequential order from top to bottom. By connecting the two continuous conductor segments 11-5 and 11-6 in permutational combinations to three output conductors 111A, 111B and 111C which control three register devices 38, seven of the eight possible permutational combinations afforded by a three-element code become available. This is accomplished by leaving the two continuous conductor segments 11-5 and 11-6 of one column unconnected, connecting one only of the two conductors of three of the columns to a different one of the three output conductors, and connecting the two conductors in the three remaining columns to different combinations of two of the three output conductors. This leaves unavailable the code combination in which three elements would have the binary value I. The provision of a third continuous conductor segment in any column is thus avoided and all may be identically provided with two continuous conductors used in the manner hereinbefore defined.

From the foregoing, it will be apparent that there is added to any five-bit combination listed at the right of FIG. 2, which may be more generally designated as an n-bit code, a three-bit code combination, which may be more generally designated an an m-bit code designating the particular column in which the five-bit code is being generated. With the seven columns on a panel each providing for the generation of thirty code combinations of a five-element binary code a total of 210 different point locations may be encoded in an eight level code using a panel of the type shown in FIG. 1. The general premise is that each encoding point on a panel shall be represented by a code combination of a sufi'lcient but optimum number of bits to assure its recognition distinguishably from the code combinations representing all other encoding point locations on the panel. It is convenient but not essential that the code combinations of conductor segments for encoding point locations in a column have uniformity of columndesignating conductor segments. In the case of panels having irregular patterns of encoding point locations the assignment of code combinations is more likely to be in accord with the general premise than to exhibit patterns of uniformity of certain bits in the code combinations relative to the physical positions of their encoding point locations.

In order to identify the items of intelligence that are to be represented by the many encoding positions on panel 16, an overlay sheet 41, shown in FIG. 6 is provided. With each column of encoding conductor segment sets occupying a space of the order of 0.050 inch wide plus such additional space as it may be necessary to allot to output conductor connections, the seven columns may be readily arranged to fit into the area of a standard 8 A X 11 inches sheet of paper, and if the columns parallel the narrow dimension of the sheet and are spaced apart across the wide dimension, there will be space available on the overlay sheet at each encoding position for identifying intelligence in the form of words, numbers, abbreviations, phrases, paragraphs, scalar locations, graphical locations, two-dimensional locations or spatial locations. As previously stated, the spacing of adjacent code generating positions in a column may be one-sixth inch, which is a standard line spacing distance on typewriters. Thus, the length of a column of 30 encoding positions will be 5 inches, and the lesser dimension of the overlay sheet and the corresponding dimension on the panel 16 will accommodate a column of encoding conductor segments with space to spare at both ends of the column. Manifestly, the location and spacing of columns of encoding conductor segments on a panel 16 is purely a matter of Table I exemplifies the kinds of items of information that may appear on an overlay each item having an associated marker indicating the location of the encoding point. In Table l the symbol appears as encoding point markers, and this, or any other appropriate symbol would serve as a guide for centering the probe tip on the marker, whether the tip were slightly larger or slightly smaller than the marker.

It will be noted that the items of intelligence that the code combinations will represent may be alpha-numerics, words, phrases, geographic locations, symbols, pictures, diagrams or any other kinds of data. Phrases may be abbreviated or, if the encoding panel affords more encoding points than are needed for a particular overlay, the words of the phrase may be displayed across other columns or on successive lines of a column, omitting encoding point markers from all but one word of the phrase, as indicated in the column headed MODEL. Also, encoding point markers on the overlay may be omitted for other purposes, such as the provision of spaces and other data group headings, as exemplified by the word TIME in the last column.

Overlay sheets or masters from which copies may be made may be prepared on a typewriter and such preparation may be facilitated by having the spacing of the columns of conductive segments on the panel match a whole number of character spacings on the typewriter. Printed forms may of course be employed instead of typewritten overlays. Also, printed forms carrying only the encoding point location registration markers may be provided, and the data represented by the point locations may be handwritten or typewritten opposite the encoding point markers on such forms.

Returning to FIG. 11, it will be noted that the relative size of the encoded point locations 52 and the probe tip area 53 permit some mist-registration of the overlay and the encoded point locations. Should the encoding point marker on the overlay (the symbol or any other marker symbol that may be used) be somewhat out of registration with the encoded point location on the panel, the relatively larger probe tip area 53 may still adequately span the encoded point location on the panel even if the probe tip is not exactly centered on the marker on the overlay.

Preferably, cooperating locating means for accurately positioning the overlay sheet 41 on the panel 16 are provided, such as, for example, the locating pins 42 carried by the panel 16 to cooperate with accurately located perforations 43 in the overlay sheet 41 (FIG. 6). This or any other effective positioning means will aid in registering the code spot markers on the overlay sheet 41 with the areas of the encoding conductor segments represented by the squares S2 in H08. and 11.

Since the overlay sheets are interchangeable a plu rality of assignments of different items ofintelligence to the code combinations may be employed. if desired, one of the code combinations on each of the different overlay sheets may be assigned to identify the overlay sheet. Alternatively, a special area on each overlay may be assigned to provide point locations employed solely for entering overlay identification. Overlays may be identified by successively pointing to a sequence of digits or other symbols which uniquely identify the overlay.

Because of the use of the overlay sheet 41 and further because of the protective covering 19 for the encoding conductor segments the tip 27 on the probe 26 does not make actual electrically conductive contact with the conductor segments. Instead, when the probe is energized by the signal generator the energiza tion occurs between the conductor 34 and ground, and an electrostatic field is produced between the probe tip 27 and the ground plane 21. The electrostatic field has two components in series, one existing between the tip 27 and those of the encoding conductor segments that the tip 27 spans, and the other existing between those encoding conductor segments and the ground plane 21. it is this latter component of the electrostatic field that appears on the output conductors ill and across the resistors 40 and accordingly is amplified by the am plificrs 37 and impressed upon the register devices 38. Because the areas of the encoding conductor segments that are subjected to the pulse are very small the fraction of the pulse that usefully appears on the output conductors lll may also be very small compared with the pulse applied between the probe tip 27 and the ground plane II. No problems are encountered in am plifying this component to an extent that will enable the operation of the register devices. The serially related capacitors across which the pulse is applied have been symbolized in FIG. 3 and identified as Cl and C2. in an embodiment of the invention having the encoding conductor segments dimensioned and spaced as hereinbefore set forth, no problems involving stray fields or intolerable leakage or crosstalk were encountered. Should such problems arise, they may be overcome by the provision of shielding between conductor segments of different sets in a column.

The pulse source 36 may be arranged to generate a single pulse for each operation of the switch 29. The amplitude of the pulse must be sufficient that the component applied to the output conductors Ill produces an output from the amplifiers 37 that rises above the operating threshold of the register devices 38. Alternatively the signal source may be arranged to generate a train of pulses continuing while the switch 29 remains actuated. The train of pulses will be long enough to assure a satisfactory output signal. The pulsing amplitude may be less than that required for a single pulse, with a repetition rate in relation to the time constants of the system such that by incremental build-up an operative level is reached and a better signal-to-noise ratio is achieved. Sine waves may be generated by the signal generator and used, in conjunction with tuned circuits, to enhance signal-to-noise ratios. it will be understood that the repetitive pulses may be peaked pulses, squared pulses, sine waves or other wave shapes selected to maximize the encoded signals and minimize the signals on non-selected conductors. It will also be understood that the hereinbefore identified resistive connections 40 are not necessarily resistors but are to be considered as impedances of appropriate type, and that appropriate impedances or filters may be connected serially in output conductors ill, all for the purpose of obtaining from the pulse source employed the optimum signal-to-noise ratio.

For the implementation of the invention exemplified in FIGS. 1, 3 and 4 the encoding conductor segments It may be comprised of conventional metallic conductive material such as copper. For other applications, ex emplified in FIGS. 7 and B, transparent conductive su bstances may be required. Referring now to FIG. 7 it is indicated that the probe 26 is to be applied directly to the protected surface of the panel 16 and that the sheet 41 is to be positioned as an underlay, beneath the panel [6. This requires that the substrate 18 and the protec tive coating 19 of the panel [6 shall be transparent and the ground plane 2] and preferably the encoding con ductor segments shall also be transparent. Clear glass or acrylic resins may be the substances of which the substrate 18 and the protective coating [9 are made. For the degree of electrical conductivity that is required, tin oxide, in a transparent form, may be used for the ground plane 21 and for the encoding conductor segments.

With the dimensions of the encoding conductor segments hereinbefore suggested the segments might not obstruct a view ofintelligence appearing on the underlay even if they should be opaque. However, by using tin oxide, which is an example of a transparent electrically conductive material, the segments would not be visible, and the information on the underlay would be readily visible.

With the arrangement shown in FIG. 7 other ways of displaying the intelligence to be encoded become possi ble. A projector device may be substituted for the underlay 41 and properly positioned to project on the underside of the panel 16 an image of intelligence that could be encoded, including markers for the encoding points. Since the image is to be viewed from the side opposite of the panel 16 the substrate may be a rear projection screen.

Still another embodiment of the invention is indicated in FIG. 8. In this embodiment the panel 16 containing the columns of encoding conductor segments is mounted on or embodied in the viewing face of a cathode ray tube 46. The same principles of construction of the panel would be applicable to this embodiment as in the case of the panel in FIG. 7. With this arrangement an image of the layout of data that might be encoded may be displayed on the phosphor coating on the inside of the face of the tube, by control of the electron beam therein in the conventional manner, and the encoding accomplished by the use of the probe 26, viewing the image through the panel 16.

Still another embodiment of the invention is shown in FIG. 9. In this figure the panel 16 which carries the encoding conductor segments is part of the structure of a keyboard controlled encoding device such as those employed as the transmitting instrumentality of teletypewriters sets. The columns of encoding conductor segments extend along and below the rows of key tops 51 and each key top has associated with it either directly or upon a movable element, such as a key lever which supports the key top, an individual electrode comparable with the tip 27 of the probe 26. Thus each code combination generated by the operation of one of the key tops would cause the energization of register devices such as those shown in FIG. and the code combinations thus registered would be available for utilization either in parallel or serial form. As is wellknown, keyboard mechanisms arranged to encode data are customarily provided with a universal member that is operated by or incident to the operation of each key top for effectuating the generation of the code combination. Such a universal member can be utilized in the keyboard shown in FIG. 9 for activating the pulse source.

The embodiments described above are examples only of patterns or geometries of conductors or uses of the encoding device. Encoding areas can be located in any patterns on any shapes or sizes of base panels. Limitations will be based on the state of the art in printed circuit techniques rather than conceptual arrangements. The use of plating-through techniques and multi-layer techniques wherein the encoding conductor segments are confined to one layer and portions of the connecting output conductors may appear in a different layer can minimize restrictions on patterns due to conductor crossing requirements. The primary requirement on patterns of conductors is that in each encoding area, the conductor segments representing desired code elements, and only those conductor segments, are present. The conductor segments or interconnecting conductors can be routed anywhere else on the panel, providing they do not come close to encoding areas where they do not belong, or come in electrical contact with other conductors.

Patterns of encoding areas can be provided to satisfy requirements of various applications. For example, code areas can be arranged to correspond with map locations of cities or other map features where a map is used as the overlay carrying information to be encoded. in such a configuration the columns" of encoding conductor segments on the panel may follow irregular paths, or the encoding positions may be scattered without discernible columnar relationships, to conform to the needs of the map. Alternatively, the encoding positions may represent points on a chart. The information to be encoded may, in any such case, be carried by an underlay as well as by an overlay, or may be a pro- I 5 jected image of the map or chart.

Furthermore, although some applications may use replaceable overlays, other applications may use replaceable base panels. Such replaceable panels could plug in and out of a basic unit or frame. Still other applications will use only one panel and one overlay, permitting fixed overlay information on the panel. Multiple pages of encoding areas can be provided on a flexible base panel which can be unrolled to expose the desired page of encoding areas. These may be used with multiple overlay pages. The substrate that carries the encoding conductor segments may be rigid, flat or non-flat, or it may be sufficiently flexible to permit it to be wrapped around and supported by a curved surface.

What is claimed is:

l. A device for digitally encoding selected separated locations comprising:

a support panel;

a plurality of conductive members carried by said support panel and capable of co-planar positioning thereon, said conductive members representing the elements of a code system and appearing in encoding areas separated from one another by distances substantially greater than the extent of the conductive members in the confines of any encoding area with each encoding area containing a unique combination of presence and absence of conductive members designative of that encoding area and its location on the panel;

a conductive probe member selectively presentable in proximity with said conductive members in any of the encoding areas; and

means for generating electrical signals and applying the signals through said probe member to impress upon the conductive members electrostatic charges that provide output signals representing elements of the code system and identifying the encoding area electrostatically influenced by the probe member.

2. Apparatus in accordance with claim I having:

output means common to the conductive members representing each of the elements of said code system and responsive to the charges impressed on the conductive members to produce one form of output signal in the case of a conductor receiving a charge reaching a predetermined threshold and a different form of output signal in the case of a conductor failing to receive a charge reaching that threshold.

3. Apparatus in accordance with claim 1 having in association therewith visible markers to identify the locations of the encoding areas of unique code combinations of the conductive members on said support member.

4. Apparatus in accordance with claim 3 having in association with said visible markers visible symbols conveying the intelligence represented by the code combinations of conductive members.

5. Apparatus in accordance with claim 4 in which the support panel is optically transparent and the conductive members are comprised of an optically transparent electro-conductive substance, and thereby afford a view through the panel and the conductive members of visible markers and visible symbols of intelligence displayed beneath the supporting panel.

6. Apparatus in accordance with claim 1 having:

encoding areas.

7. Apparatus in accordance with claim 6 including a keyboard assembly of keytops having one of the probe members individual to each keytop.

8. Apparatus in accordance with claim 1 having repetitive appearances of the code system of conductive members;

additional conductive members associated with each of the appearances of the code system of conductive members and common to all of the encoding areas of the code system of conductive members with which they are associated to receive electrostatic charges along with the other conductive members at any encoding area and thereby to represent the elements of a code system supplementing the first mentioned code system of conductive members; and

output means associated with said additional conductive members in unique combinations from one to another of the several repetitive appearances of the code system of conductive members to identify the particular appearance of the code system of conductive members in which an encoding area has received electrostatic charges from the probe member.

9. Apparatus in accordance with claim 8 in which the number of additional conductive members is the same for all appearances of the code system of conductive members.

l0. Apparatus in accordance with claim 8 in which the output means for the additional conductive members provide code combinations of elements that additively supplement the first mentioned code combinations of elements.

ll. Apparatus in accordance with claim I including:

means for activating the electrical signal generating means solely responsive to presentation of the probe element in proximity with an encoding area.

12. An encoding device in accordance with claim l including means operably associated with the probe element for causing activation of the signal generating means.

13. An encoding device in accordance with claim l2 wherein the signal generating means is arranged to emit a single pulse for each activation thereof.

14. An encoding device in accordance with claim l2 wherein:

said signal generating means is arranged to emit a train of pulses at a frequency producing incremental build-up of the electrostatic charge while the means for causing activation of the signal generating means remains operated.

I that provides a maximum of 2" 15. An encoding device in accordance with claim 12 wherein:

the signal generating means is arranged to emit a continuous series of sine waves while the means for causing activation of the signal generating means remains operated.

16. An encoding device in accordance with claim 2 encoding areas each containing a unique combination of presence and absence of conductive members in which n is the number of output means for said conductive members.

l7. An encoding device in accordance with claim I wherein:

the separation of the encoding areas, the size of an encoding area and the size of the probe member are so interrelated that the probe member cannot register simultaneously with two encoding areas and registration of the probe member to any extent with all of the conductive members in an encoding area will result in the generation of the code combination represented by that encoding area, whereby unambiguous code combinations are invariably generated.

18. An encoding device in accordance with claim I wherein:

the encoding areas are scattered over the area of the support panel in any desired pattern that provides separation between any two adjacent encoding areas sufficient to preclude concurrent registration of the probe member with portions of any two encoding areas.

19. An encoding device in accordance with claim I wherein:

The support panel exposes a non-planar surface to which the probe member is to be presented; and

the conductive members are located on the nonplanar surface of the support panel.

20. Apparatus in accordance with claim 1 having:

a conductive sheet associated with a surface of the support panel opposite the surface having the encoding areas for presentation of the probe member, said conductive sheet serving as a ground plane.

2|. Apparatus in accordance with claim I having:

interconnecting conductors connected to and serving in common all encoding conductive members representing the same element of the code, at least one of said interconnecting conductors being disposed in a plane other than the plane occupied by any of the encoding members.

22. An encoding device comprising:

a dielectric panel;

a group of n alignments of conductor segments supported in one plane by said panel and providing a maximum of 2" subdivisional units of conductor segments and discontinuities in each alignment such that each alignment includes a maximum of 2"[2 subdivisional units of conductor segments and a maximum of 2'l2 subdivisional units of dielectric portion so disposed as to provide encoding areas at predetermined points along the overall extent of the alignments comprising different combinations of conductor segments of the n alignments up to a total of 2" combinations;

a probe element presentable in registry with the combination of the conductor segments at any of the .7 encoding areas and comprising a conductive body provided with a probing surface having one of its dimensions at least as great as the distance across the alignments of conductor segments and its dimension in a direction normal to that of the first mentioned dimension not greater than the dimension of the encoding area in that direction plus the distance to the next encoding area in the same group of alignments of conductor segments; means for precluding surface contact between the presented probe and the conductor segments;

means for electrically interconnecting as a set all of the conductor segments in each of the alignments of conductor segments;

an output conductor for each set of interconnected conductor segments; and

means for generating electrical signals and applying them through the probe element to impress upon the conductor segments with which it is in registry an electrostatic charge.

23. An encoding device in accordance with claim 22 having electroresponsive means associated with each of the output conductors for registering the occurrence of an electrostatic charge on its related alignment of conductor segments and thereby registering a code combination generated by the probe element.

24. An encoding device in accordance with claim 22 including:

at least one additional group of n alignments of conductor segments supported in one plane by the dielectric panel and having output conductors connecting them to the aforementioned output conductors;

at least one unbroken conductor of a maximum ofm such conductors associated with at least all but one of the groups of alignments of conductor segments and of sufficient length to traverse all of the encoding areas in the group of alignments of conductor segments so as to be electrostatically charged by the probe at any of its positions of registry with the combinations of conductor segments in the group of alignments of conductor segments;

a maximum of m output conductors for said unbroken conductors; and

interconnections between said unbroken conductors and the last mentioned output conductors in patterns uniquely different for the groups of n alignments of conductor segments to identify on said last mentioned output conductors a maximum of 2" groups of alignments of conductor segments.

25. An encoding device in accordance with claim 24 including:

visible indicia of intelligence represented by the combinations of conductor segments up to a maximum 2""" different items ofintelligence; and

a visible marker associated with each item of intelligence for indicating positions for presentation of the probe element.

26. An encoding device in accordance with claim 25 including:

an overlay sheet for the panel carrying at least the visible indicia ofintelligence.

27. An encoding device in accordance with claim 25 including:

an overlay sheet for the panel carrying at least the visible markers;and locating means cooperatively lnterassoclatlng the overlay sheet and the panel to bring the visible markers into registry with the combinations of conductor segments on the panel.

28. An encoding device in accordance with claim 27 wherein the overlay sheet is provided with a minimum of two perforations and the panel is provided with a like number of protruding members adapted to receive the perforations in the overlay sheet and thereby establish registry.

29. An encoding device in accordance with claim 22 in which the means for precluding surface contact between the probe element and the conductor segments is a protective covering overlying the conductor segments on the panel.

30. An encoding device in accordance with claim 22 including:

means operably associated with the probe element for causing activation of the signal generating means.

31. An encoding device in accordance with claim 30 wherein:

upon each activation thereof.

32. An encoding device in accordance with claim 30 wherein:

said signal generating means is arranged to emit, while the means for causing activation of said signal generating means remain operated, a train of pulses at a frequency producing incremental build-up of the electrostatic charge to a predetermined level.

33. An encoding device in accordance with claim 30 wherein said signal generating means is arranged to emit a sine wave while the means for causing activation of the signal generating means remains operated.

34. An encoding device in accordance with claim 23 in which the electro-responsive devices are binary elements.

35. An encoding device in accordance with claim 23 including:

a sheet of conductive material associated with the panel in relatively uniformly spaced relation to the conductive segments and electrically connected to one of two output terminals of the signal generating means and in common to one of two input terminals of all of the electro-responsive devices, the probe element being connected to the other output terminal of the signal generating means and the conductive segments being connected to the other input terminal of their respective electroresponsive devices, whereby the electrostatic charge produced by applying electrical signals through the probe element is comprised of two components, one component occurring between the probe element and the conductor segments and the other occurring between the conductor segments and the sheet of conductive material and consequently appearing across the inputs to the electro-responsive devices.

t l O t 93 UNITED STA'IES PATENT OFFICE CERTIFICATE G33 CORRECTION mm1 0. 3,69v,681 Dated October 10, I972 LWCNOIU) Harry 'I. Larson and Richard T. Loewe 1t is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 3 "of" should read -or- Col. 2, line 10 after "respectively" insert --defining- Col. 2, line 27 begin new paragraph with "The probe has" Col. 3, line 21 begin new paragraph with "Additionally" Col. 9, line 39 after "bit insert -code- Col. 9, line 42 "an" (first occurrence) should read -as- Col. 10, line 30 "174" should read -l/4- Col. 10, line 35 "E2" should read +E2- Col. l5, line 15 before "encoding areas" insert a probe member individual to each of the-- Col. 18, line 26 before "upon each activation thereof." insert -said signal generating means is arranged to emit a single pulse-- Signed and sealed this 6th day of March 1973.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3828128 *Apr 18, 1972Aug 6, 1974De Beauclair WManual input device for data-processing system and the like
US4525032 *Jul 27, 1982Jun 25, 1985The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern IrelandLiquid crystal reusable signature comparison
US4568798 *Nov 10, 1983Feb 4, 1986Preh Elektrofeinmechanische Werke Jakob Preh Nachf. Gmbh & Co.Resistive layer containing point electrodes; comprising carbon-coated silica carrier and a binder
US6259043Nov 12, 1996Jul 10, 2001International Business Machines CorporationMethods, systems and products pertaining to a digitizer for use in paper based record systems
US20110304548 *Nov 16, 2009Dec 15, 2011Kenji YoshidaMouse provided with a dot pattern reading function
WO2011143594A2 *May 13, 2011Nov 17, 2011Tyco Electronic CorporationSystem and method for detecting locations of touches on a touch sensor
U.S. Classification178/18.1
International ClassificationG06F3/041, G06F3/033, G06F3/044
Cooperative ClassificationG06F3/044
European ClassificationG06F3/044