Digitizer with illuminable working surface

• US 5,028,744 A
• Filed: 01/11/1990
• Issued: 07/02/1991
• Est. Priority Date: 01/11/1990
• Status: Expired due to Fees

• Current Assignee: Calcomp Technology, Inc. (GTCO Calcomp, Incoporated)
• Original Assignee: Summagraphics Corp.
• Inventors: Siefer, David A., Purcell, Alexander M.
• Primary Examiner(s): Schreyer, Stafford D.
• Application Number:
  US07/463,612
• Time in Patent Office: 537 Days
• Field of Search: 178/18, 178/19, 178/20, 340/712, 340/716, 362/33, 362/97
• US Class Current: 178/18.11
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means

Abstract

Digitizer tablet and digitizer tablet structure having an illuminable working surface are disclosed. A space between a top translucent layer having the working surface and a source of light is provided so as to eliminate or minimize undesirable lighting effects at the working surface. In the preferred embodiments, the space is an air gap (e.g. 0.060-0.250 inch) immediately adjacent the top translucent layer. The air gap is formed by transparent optical fibers or solid glass or acrylic rods. Back-lighted, translucent, back-lightable (without light source) and surface lighted digitizer tablet embodiments are described.

Claims

1. A digitizer tablet structure having a working surface which may be illuminated, comprising:

a light-transmitting layer one surface of which is said working surface;

a position determining structure disposed generally coextensive with said working surface and which cooperates with an object movable on or adjacent said working surface when at least one of said position determining structure and said movable object is energized to generate signals representative of the position of said movable object with respect to said working surface;

a substantial space between said position determining structure and said light-transmitting layer; and

spacer means in said space between said position determining structure and said light-transmitting layer for spacing said light transmitting layer from at least said position determining structure, said spacer means being light transmitting and occupying only a small volume of said space;

said digitizer structure being configured to project light from a source to said light-transmitting layer through said space to illuminate said working surface.

2. The digitizer tablet structure of claim 1 wherein said light-transmitting layer is immediately adjacent said space.

3. The digitizer tablet structure of claim 1 wherein said spacer means maintains a uniform space height of between about 0.030 inch and about 1.0 inch.

4. The digitizer tablet structure of claim 1 wherein said spacer means comprises at least one elongated element extending for a substantial distance in said space generally parallel to said light-transmitting layer.

5. The digitizer tablet structure of claim 4 wherein said at least one elongated element has a cylindrical outer surface of a diameter substantially equal to said height of said space.

6. The digitizer tablet structure of claim 5 wherein said at least one elongated element is an optical fiber.

7. The digitizer tablet structure of claim 5 wherein said at least one elongated element is a solid cylindrical rod.

8. The digitizer tablet structure of claim 1 wherein said position determining structure is substantially light transmitting, and said digitizer tablet structure is configured to project light to said light-transmitting element from said source through said position determining structure.

9. The digitizer tablet structure of claim 8 including said light source which is disposed on a side of said position-determining structure opposite said space.

10. The digitizer tablet structure of claim 1 wherein said digitizer structure is configured to project light from said source to said space without passing through said position determining structure.

11. The digitizer tablet structure of claim 10 wherein said light source has a light-projecting portion, said digitizer tablet structure including said light-projecting portion disposed between said position-determining structure and said space.

12. The digitizer tablet structure of claim 11 wherein said light-projecting portion of said light source comprises a thin panel.

13. The digitizer tablet structure of claim 12 wherein said panel is a fiber optic panel.

14. The digitizer tablet structure of claim 12 wherein said panel is an electroluminescent panel.

15. The digitizer tablet structure of claim 1 wherein said space is an air space.

38. The digitizer tablet structure of claim 11 including means for joining said light-transmitting layer, said spacer means and said light-projecting portion into a first unit, and means for forming a second unit comprising said position determining structure, said first unit being structured to fit over and be usable with said second unit such that said working surface of said first unit functions as a working surface for position determination thereon in cooperation with said second unit.

39. The digitizer tablet structure of claim 11 including means for joining said light-transmitting layer, said spacer means, said light-projecting portion and said position determining structure into a single unit.

16. A translucent digitizer tablet structure having a working surface which may be illuminated, comprising:

a light-transmitting layer one surface of which is said working surface;

a substantially light-transmitting position determining structure generally coextensive with said working surface and which cooperates with an object movable on or adjacent said working surface when at least one of said position determining surface and said movable object is energized to generate signals representative of the position of said movable object with respect to said working surface;

a substantial space between said position determining structure and said light-transmitting layer; and

spacer means in said space between said position determining structure and said light-transmitting layer for spacing said light transmitting layer at least from said position determining structure, said spacer means being light transmitting and occupying only a small volume of said space;

said digitizer tablet passing light projected from a side of said position-determining structure opposite said space to said working surface through said space to illuminate said working surface.

17. The digitizer tablet structure of claim 16 wherein said light-transmitting layer is immediately adjacent said space.

18. The digitizer tablet structure of claim 17 wherein said spacer means maintains a uniform space height of between about 0.030 inch and about 1.0 inch.

19. The digitizer tablet structure of claim 16 including said light source which is disposed on a side of said position-determining structure opposite said space.

20. The digitizer tablet structure of claim 16 wherein said spacer means comprises at least one elongated element having a cylindrical outer surface of a diameter substantially equal to said height of said space, said elongated element extending for a substantial distance in said space substantially parallel to said light-transmitting layer.

21. The digitizer tablet structure of claim 20 wherein said at least one elongated element is an optical fiber.

22. The digitizer table structure of claim 20 wherein said at least one elongated element is a solid cylindrical rod.

23. The digitizer tablet of structure of claim 16 wherein said space is an air space.

40. The digitizer tablet structure of claim 16 including means for joining said light-transmitting layer, said spacer means and said position determining structure into a single unit.

41. The digitizer tablet structure of claim 19 including means for joining said light-transmitting layer, said spacer means, said position determining structure and said light source into a single unit.

24. A digitizer tablet structure having a working surface which may be illuminated, comprising:

a light-transmitting layer one surface of which is said working surface;

a position determining structure generally coextensive with said working surface and which cooperates with an object movable on or adjacent said working surface when at least one of said position determining structure and said movable object is energized to generate signals representative of the position of said movable object with respect to said working surface;

a substantial space between said position determining structure and said light-transmitting layer; and

said digitizer structure being configured to project light from a source through said space to said light-transmitting layer without passing through said position determining structure to illuminate said working surface.

25. The digitizer tablet structure of claim 24 wherein said light-transmitting layer is immediately adjacent said space.

26. The digitizer tablet structure of claim 24 wherein said light source has a light-projecting portion, said digitizer tablet structure including said light projecting portion disposed between said position determining structure and said space.

27. The digitizer tablet structure of claim 26 wherein said light-projecting portion of said light source comprises a thin panel.

28. The digitizer tablet structure of claim 27 wherein said panel is a fiber optic panel.

29. The digitizer tablet structure of claim 27 wherein said panel is an electroluminescent panel.

30. The digitizer tablet structure of claim 24 wherein said space has a height of between about 0.030 inch and about 1.0 inch.

31. The digitizer tablet structure of claim 24 including spacer means in said space for maintaining a given space height, said spacer means being light-transmitting and occupying only a small volume of said space.

32. The digitizer tablet structure of claim 31 wherein said spacer means comprises at least one elongated member having a cylindrical outer surface of a diameter substantially equal to said height of said space, said elongated member extending for a substantial distance in said space substantially parallel to said first light-transmitting layer.

33. The digitizer tablet structure of claim 32 wherein said at least one elongated element is an optical fiber.

34. The digitizer tablet structure of claim 32 wherein said at least one elongated element is a solid cylindrical rod.

35. The digitizer tablet structure of claim 24 wherein said space is an air space.

36. The digitizer tablet structure of claim 26 including means for joining said light-transmitting layer and said light-projecting portion into a first unit, and means for forming a second unit comprising said position determining structure, said first unit being structured to fit over and be usable with said second unit such that said working surface of said first unit functions as a working surface for position determination thereon in cooperation with said second unit.

37. The digitizer tablet structure of claim 26 including means for joining said light-transmitting layer, said light-projecting portion and said position determining structure into a single unit.

42. A digitizer tablet structure having a working surface which may be illuminated, comprising:

a light-transmitting layer one surface of which is said working surface;

a position determining structure generally coextensive with said working surface and which cooperates with an object movable on or adjacent said working surface when at least one of said position determining structure and said movable object is energized to generate signals representative of the position of said movable object with respect to said working surface;

a substantial space between said position determining structure and said light-transmitting layer;

means for illuminating said working surface comprising means disposed between said position-determining structure and said space for projecting light through said space to said light-transmitting layer to illuminate said working surface; and

means for joining said light-transmitting layer, said thin panel and said position determining structure into a single unit.

43. The digitizer tablet structure of claim 42 wherein said means for projecting light comprises a thin panel.

44. The digitizer tablet structure of claim 43 wherein said panel is a fiber optic panel.

45. The digitizer tablet structure of claim 43 wherein said panel is an electroluminescent panel.

46. A tablet-type structure having a first outer generally flat surface which may function as a working surface and which may be illuminated and a second opposed outer surface, comprising:

a light-transmitting layer one surface of which is said first outer surface;

a substantial space adjacent a side of said light-transmitting layer opposite said first surface;

a thin panel disposed adjacent said space for projecting light through space and through said light-transmitting layer to illuminate said first outer surface; and

means for joining said first light-transmitting layer and said panel into a unit having said first and second opposed outer surfaces.

47. The digitizer tablet structure of claim 46 wherein said panel is a fiber optic panel.

48. The digitizer tablet structure of claim 46 wherein said panel is an electroluminescent panel.