Information processing

• US 5,113,041 A
• Filed: 12/28/1990
• Issued: 05/12/1992
• Est. Priority Date: 12/28/1990
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph (AT&T, Inc.)
• Sponsoring Entity: American Telephone & Telegraph (AT&T, Inc.)
• Inventors: Blonder, Greg E., Boie, Robert A.
• Primary Examiner(s): SCHREYER, STAFFORD
• Time in USPTO: 501 Days
• Field of Search: 178/18, 178/19
• US Class Current: 345/173
• CPC Class Codes: G06F 3/044 : by capacitive means

Abstract

Information processing, for example by means of a computer, is served by a tablet in combination with an inputting implement such as stylus or human finger. Such a tablet-implement combination may serve in lieu of or ancillary to other inputting means such as a keyboard. Implement positional information, e.g., as contacting the tablet, depends upon interpolation as between segmenting lines in the tablet. Cost advantage commensurate with resolution/noise desiderata is ascribable to use of analog information (without digitization) in interpolation.

Claims

1. Apparatus for information processing comprising an inputting implement, together with a tablet which includes a free surface inputting region accessible to the implement, an initial signal generator including said implement or said region, an initial signal detector including the other of said implement or said region, in which positioning of the implement within the inputting region is determinative of at least part of the information to be processed, together with provision for generation of a final signal including such positioning information, said region being electrically segmented into at least five segments in at least one direction within the said region, each such segment being at least ten times coarser than the resolution of positioning information included in the final signal, together with means for interpolating position of the inputting element within a segment thereby resulting in positioning information of such resolution, further including means for electrical pulsing of the said initial signal generator for producing a corresponding time-dependent initial signal in the said initial signal detector, whereby the said final signal is yielded and is transmitted to an associated unit of the said information processing apparatus

characterized in that the said initial signal comprises time-dependent, undigitized, analog initial positioning information, and in that the said initial signal detector includes a time domain, centroid-finding filter for interpolating position to yield positioning information of such resolution for inclusion in the final signal.

2. Apparatus of claim 1 in which the tablet and inputting element are capacitively coupled so that the signal produced by the said initial signal generator is received by the said initial signal detector through circuitry including capacitive coupling, and in which the said region is segmented in two directions within the said region, whereby both initial and final positioning information contains information pertaining to both directions.

3. Apparatus of claim 2 in which the said two directions are essentially orthogonal, whereby positioning information contains x and y information.

4. Apparatus of claim 3 in which said inputting element comprises a stylus having a tip which contacts the free surface of said region in the course of inputting, said stylus including an element serving as one of the two capacitor plates involved in the said capacitive coupling, and in which electrical segmentation of the said tablet is by electrically conductive segmenting lines.

5. Apparatus of claim 4 in which the initial signal generator includes the said tablet and said apparatus includes means for sequentially pulsing such segmenting lines in cyclical fashion.

6. Apparatus of claim 4 together with force-sensitive element for sensing the force with which the stylus engages the said region so that the initial signal includes such force information.

7. Apparatus of claim 6 in which the said force-sensitive element is physically associated with the stylus and comprises a capacitor.

8. Apparatus of claim 6 in which the force-sensitive element is physically associated with the stylus and comprises a strain guage.

9. Apparatus of claim 4 including an associated display device to produce a display incorporating final positioning information.

10. Apparatus of claim 9 in which the associated display underlies the said tablet at the inputting region, in which the display device provides a display incorporating essentially real time positioning information so as to appear to be responsive to the stylus, and in which at least the said inputting region is of sufficient transparency as to permit viewing the display therethrough.

11. Apparatus of claim 4 including a display device underlying the tablet for producing a visible display of a pattern introduced by the said inputting implement.

12. Apparatus of claim 11 in which the said display is a liquid crystal display device.

31. Apparatus of claim 1 in which said inputting implement comprises at least two styli for simultaneously coupling with said tablet.

32. Apparatus of claim 31 in which said inputting implement comprises three styli.

13. Method for information processing comprising introducing information by capacitive interaction of an inputting implement and an inputting region of an electrically segmented tablet, electrically pulsing the implement or tablet so as to yield an initial time-dependent signal containing initial position data for said implement relative to the said region, interpolating such initial position data so as to yield a final signal containing final position data which establishes position at a resolution which is better than that of electrical segmentation,

characterized in that initial position data is in analog form and is input to a time domain, centroid-finding filter, thereby yielding said final position data.

14. Method of claim 13 in which the said inputting implement is a stylus having a point in contact with the said inputting region during at least a part of the time of introduction of information to be processed, and in which the said time-dependent signal varies in accordance with the force with which the point engages the inputting region.

15. Method of claim 14 in which the initial signal comprises information comprising movement of the implement during a time period of uninterrupted contact with the inputting region so that said initial signal contains position data which varies correspondently.

16. Method of claim 15 in which information to be processed includes cursive writing.

17. Method of claim 15 in which information to be processed includes signature verification.

18. Method of claim 15 in which said initial signal contains information dependent on velocity of the implement during such movement.

19. Apparatus for information processing comprising an inputting implement, together with a tablet, which includes a free surface inputting region accessible to the implement, an initial signal generator including said implement or said region, an initial signal detector including the other of said implement or said region, in which positioning of the implement within the inputting region is determinative of at least part of the information to be processed, together with provision for generation of a final signal including such positioning information, said region being electrically segmented into at least five segments in at least one direction within the said region, each such segment being at least ten times coarser than the resolution of positioning information included in the final signal, together with means for interpolating position of the inputting element within a segment thereby resulting in positioning information of such resolution, further including means for electrical pulsing of the said initial signal generator for producing a corresponding time-dependent initial signal in the said initial signal detector, whereby the said final signal is yielded and is transmitted to an associated unit of the said information processing apparatus

characterized in that the said inputting implement comprises a stylus provided with a force-sensitive element for sensing the force with which the stylus engages the said region and in which such force-sensitive element depends upon a capacitor having a first plate which moves relative to a second capacitor plate responsive to such force so as to result in a force-dependent change in capacitance.

20. The apparatus of claim 19 in which the force-dependent change in capacitance is a consequence of movement of the said first plate.

21. Apparatus of claim 19 in which movement of the said first plate is a maximum of 0.5 mm for a force of 200 grams.

22. Apparatus of claim 19 in which the said capacitor is part of circuitry responsible for positioning so that a force-dependent change in capacitance changes the amplitude of such positioning information as contained within the final signal.

23. Apparatus of claim 19 further

characterized in that the said initial signal comprises time-dependent, undigitized, analog initial positioning information, and in that the said initial signal detector includes a time domain, centroid-finding filter for interpolating position to yield positioning information of such resolution for inclusion in the final signal.

24. Apparatus for information processing comprising an inputting implement, together with a tablet, which includes a free surface inputting region accessible to the implement, an initial signal generator including said implement or said region, an initial signal detector including the other of said implement or said region, in which positioning of the implement within the inputting region is determinative of at least part of the information to be processed, together with provision for generation of a final signal including such positioning information, said region being electrically segmented into at least five segments in at least one direction within the said region, each such segment being at least ten times coarser than the resolution of positioning information included in the final signal, together with means for interpolating position of the inputting element within a segment thereby resulting in positioning information of such resolution, further including means for electrical pulsing of the said initial signal generator for producing a corresponding time-dependent initial signal in the said initial signal detector, whereby the said final signal is yielded and is transmitted to an associated unit of the said information processing apparatus said apparatus further including a display device underlying the tablet for producing a visible display of a pattern introduced by the said inputting implement

characterized in that the said tablet and inputting element are capacitively coupled whereby positioning information is capacitance dependent, in which segmentation of the said tablet is by electrically conductive segmenting lines with each such segment being defined by ganged segmenting lines, electrically connected in parallel, in which each line contained in a gang is of insufficient thickness as to significantly interfere with transparency, sufficiency of capacitive coupling being assured by multiplicity of lines within the gang.

25. Apparatus of claim 24 in which each ganged segmenting line within the said region is of a maximum thickness of 10 μ

m as viewed through the said free surface.

26. Apparatus of claim 24 in which parallel electrical connection of ganged segmenting lines comprises buses within the said region.

27. Apparatus of claim 24

characterized in that the said initial signal comprises time-dependent, undigitized, analog initial positioning information, and in that the said initial signal detector includes a time domain, centroid-finding filter for interpolating position to yield positioning information of such resolution for inclusion in the final signal.

28. Apparatus for information processing comprising an inputting implement, together with a tablet, which includes a free surface inputting region accessible to the implement, an initial signal generator including said implement or said region, an initial signal detector including the other of said implement or said region, in which positioning of the implement within the inputting region is determinative of at least part of the information to be processed, together with provision for generation of a final signal including such positioning information, said region being electrically segmented into at least five segments in at least one direction within the said region, each such segment being at least ten times coarser than the resolution of positioning information included in the final signal, together with means for interpolating position of the inputting element within a segment thereby resulting in positioning information of such resolution, further including means for electrical pulsing of the said initial signal generator for producing a corresponding time-dependent initial signal in the said initial signal detector, whereby the said final signal is yielded and is transmitted to an associated unit of the said information processing apparatus

characterized in that the said inputting implement is a stylus having a point in contact with the said inputting region during at least a part of the time of introduction to be processed, in which electrical segmentation is by electrically conductive segmenting lines and in which provision is made for electrically spacing such lines relative to the portion of the tablet-contacting stylus determinative of positioning information, such spacing being within the range of from 0.25×

to 4×

segment dimension, with a view to obtaining appropriate interpolation accuracy commensurate with signal-to-noise ratio.

29. Apparatus of claim 28 in which the said spacing comprises a spreading layer of conductivity sufficiently small as to permit functioning, a surface of such layer corresponding with the free surface of the said region.

30. Apparatus of claim 28

characterized in that the said initial signal comprises time-dependent, undigitized, analog initial positioning information, and in that the said initial signal detector includes a time domain, centroid-finding filter for interpolating position to yield positioning information of such resolution for inclusion in the final signal.