System and method for solid state illumination for DMD devices

• US 5,151,718 A
• Filed: 12/31/1990
• Issued: 09/29/1992
• Est. Priority Date: 12/31/1990
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Nelson, William E.
• Primary Examiner(s): Moses, R. L.
• Application Number:
  US07/636,651
• Time in Patent Office: 638 Days
• Field of Search: 346/160, 346/153.1, 355/229, 101/DIG. 37, 340/782, 340/783
• US Class Current: 347/130
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: B41J 2/465 using masks, e.g. light-switching masks
• CPC Class Codes: G06K 15/1238 simultaneously exposing more than one point

Abstract

There is disclosed an optic system for illuminating a DMD array in a xerographic printing process consisting of an array of LED emitters constructed to efficiently replace the conventional tungsten source used in prior art. The array can be geometrically configured or electrically operated by strobing or varying the brightness of individual pixels to compensate for other system optical deficiencies and results in improved printing process. By exposure strobing the LED source correction for fuzzy line edges can be achieved.

Claims

1. A spatial light modulator array comprising:

a spatial light modulator device operable to modulate light impacting a surface of said device, wherein said device includes a plurality of individually controlled cells;

a plurality of individual solid state light emitting elements arranged in a unitary structure and focused on said spatial light modulator device; and

a receptor for receiving light from selected ones of said individually controlled cells.

2. The array set forth in claim 1 wherein said unitary structure includes a plurality of individual lenses mated with each said light emitting element.

3. The array set forth in claim 2 wherein at least some of said lenses are anamorphic.

4. The array set forth in claim 1 further comprising:

a system for adjusting the relative position of certain ones of said elements with respect to said DMD so as to effect the optical light transfer between said structure and said DMD array.

5. The array set forth in claim 2 wherein said unitary structure is flexible.

6. The array set forth in claim 2 wherein at least some of said elements have different light emitting capability from other such elements.

7. The array set forth in claim 1 wherein light emitted from said elements is uniform as viewed from a plane offset from the plane of said structure along an optical axis.

8. The array set forth in claim 1 further comprising:

a system for selectively enabling any of said elements.

9. The array set forth in claim 8 further comprising:

a system for varying the on/off time of any of said elements independent from each other.

10. The array set forth in claim 1 further comprising:

a system for strobing said elements.

11. The array set forth in claim 1 wherein said array is used in a xerographic process wherein said receptor is moving and wherein said array includes:

a system for strobing said elements to create sharp pixel images with respect to said moving receptor.

12. The array set forth in claim 11 further comprising:

a system for adjusting said strobe to the movement said receptor.

13. A xerographic printer comprising:

a spatial light modulator device operable to modulate light impacting a surface of said device wherein said device includes a plurality of individually controlled cells;

a plurality of individual solid state light emitting elements arranged in a unitary structure and focused on said spatial light modulator device; and

a receptor for receiving light from selected ones of said individually controlled cells.

14. The printer set forth in claim 13 wherein said unitary structure includes a plurality of individual lenses mated with each said light emitting element.

15. The printer set forth in claim 14 wherein at least some of said lenses are anamorphic.

16. The printer set forth in claim 13 further comprising:

a mechanism for adjusting the relative position of certain ones of said elements with respect to said DMD so as to effect the optical light transfer between said structure and said DMD array.

17. The printer set forth in claim 14 wherein said unitary structure is flexible.

18. The printer set forth in claim 14 wherein at least some of said elements have different light emitting capability from other such elements.

19. The printer set forth in claim 13 wherein light emitted from said elements is uniform as viewed from a plane offset from the plane of said structure along an optical axis.

20. The printer set forth in claim 13 further comprising:

a system for selectively enabling any of said elements.

21. The printer set forth in claim 13 further comprising:

a system for varying the on/off time of any of said elements independent from each other.

22. The printer set forth in claim 13 further comprising:

a system for strobing said elements.

23. The printer set forth in claim 13 wherein receptor is rotating and wherein said array includes:

a system for strobing said elements to create sharp pixel images with respect to said rotating receptor.

24. The printer set forth in claim 23 further comprising:

a system for adjusting said strobe to the movement of said receptor.

25. A method of establishing a xerographic printer comprising the steps of:

positioning a spatial light modulator device operable to modulate light impacting a surface of said device, wherein said device includes a plurality of individually controlled cells;

arranging a plurality of individual solid state light emitting elements in a unitary structure and focused on said spatial light modulator device; and

a receptor for receiving light from selected ones of said individually controlled cells.

26. The method set forth in claim 25 further comprising the step of:

mating a plurality of individual lenses with each said light emitting element.

27. The method set forth in claim 26 wherein at least some of said lenses are anamorphic.

28. The method set forth in claim 25 further comprising the step of:

adjusting the relative position of certain ones of said elements with respect to said DMD so as to effect the optical light transfer between said structure and said DMD array.

29. The method set forth in claim 26 wherein said unitary structure is flexible.

30. The method of operating a spatial light modulator array comprising the steps of:

arranging a plurality of individual solid state light emitting elements in a unitary structure; and

focusing light from said elements onto a spatial light modulator device operable to modulate said light impacting a surface of said device, wherein said device includes a plurality of individually controlled cells.

31. The method set forth in claim 30 wherein said unitary structure includes a plurality of individual lenses mated with each said light emitting element.

32. The method set forth in claim 31 wherein at least some of said lenses are anamorphic.

33. The method set forth in claim 30 further comprising the step of:

adjusting the relative position of certain ones of said elements with respect to said DMD so as to effect the optical light transfer between said structure and said DMD array.

34. The method set forth in claim 31 wherein said unitary structure is flexible.

35. The method set forth in claim 31 further including the step of:

generating different light levels from various of said elements.

36. The method set forth in claim 35 wherein light emitted from said elements is uniform as viewed from a plane offset from the plane of said structure along an optical axis.

37. The method set forth in claim 30 further comprising the step of:

selectively enabling any of said elements.

38. The method set forth in claim 30 further comprising the step of:

varying the on/off time of any of said elements independent from each other.

39. The method set forth in claim 30 further comprising the step of:

strobing said elements.

40. The method set forth in claim 30 wherein said array is used in a xerographic process wherein said receptor is moving and wherein said method includes the step of:

strobing said elements to create sharp pixel images with respect to said moving receptor.

41. The method set forth in claim 40 further comprising the step of:

adjusting said strobe to the movement of said receptor.