Electromechanical grating display system with segmented waveplate

• US 6,476,848 B2
• Filed: 12/21/2000
• Issued: 11/05/2002
• Est. Priority Date: 12/21/2000
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Kowarz, Marek W., Phalen, James G., Brazas, John C. Jr.
• Primary Examiner(s): PHAM, HAI CHI
• Application Number:
  US09/746,399
• Publication Number:
  US 20020113860A1
• Time in Patent Office: 684 Days
• Field of Search: 347/237, 347/239, 347/241, 347/247, 347/255, 347/256, 353/20, 359/130, 359/132, 359/133, 359/242, 359/245, 359/246, 359/301, 359/563, 359/566
• US Class Current: 347/255
• CPC Class Codes: B41J 2/47 using the combination of scanning and modulation of light
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements

Abstract

A display system, including: a light source providing illumination; a linear array of electromechanical grating devices of at least two individually operable devices receiving the illumination wherein a grating period is oriented at a predetermined angle with respect to an axis of the linear array wherein the angle is large enough to separate diffracted light beams prior to a projection lens system for projecting light onto a screen; a polarization sensitive element that passes diffracted light beams according to their polarization state; a segmented waveplate for altering the polarization state of a discrete number of selected diffracted light beams wherein the segmented waveplate is located between the linear array and the polarization sensitive element, a scanning element for moving the selectively passed diffracted light beams on the screen; and a controller for providing a data stream to the individually operable devices.

Claims

1. A display system, comprising:

a light source providing illumination;

a linear array of electromechanical grating devices of at least two individually operable devices receiving the illumination wherein a grating period is oriented at a predetermined angle with respect to an axis of the linear array wherein the angle is large enough to separate diffracted light beams prior to a projection lens system for projecting light onto a screen;

a polarization sensitive element that passes diffracted light beams according to their polarization state;

a segmented waveplate for altering the polarization state of a discrete number of selected diffracted light beams wherein the segmented waveplate is located between the linear array and the polarization sensitive element;

a scanning element for moving the selectively passed diffracted light beams on the screen; and

a controller for providing a data stream to the individually operable devices.

2. The display system of claim 1, wherein the linear array is constructed of electromechanical conformal grating devices.

3. The display system of claim 1, wherein the linear array is constructed of electromechanical grating light valves.

4. The display system of claim 1, wherein the predetermined angle is defined to be perpendicular to the axis of the linear array.

5. The display system of claim 1, wherein the linear array receives linearly polarized illumination.

6. The display system of claim 5, wherein the polarization sensitive element is a polarization beamsplitter and delivers the linearly polarized illumination to the linear array.

7. The display system of claim 5, wherein the segmented waveplate rotates the polarization state of the discrete number of selected diffracted light beams by ninety degrees with respect to the linearly polarized illumination while leaving the polarization state of other diffracted light beams unmodified.

8. The display system of claim 1, wherein the light source is of a single color.

9. The display system of claim 1, wherein the light source produces a plurality of colors that are sequential in time and the controller is synchronized with the light source.

10. The display system of claim 1, wherein the light source produces a plurality of colors at the same time and the display system includes a corresponding number of linear arrays of electromechanical grating devices.

11. The display system of claim 10, wherein the segmented waveplate further includes corresponding segmented regions for altering the polarization state of the selected diffracted light beams for each of the plurality of colors.

12. The display system of claim 1 comprising at least three light sources and includes a corresponding number of linear arrays of electromechanical grating devices.

13. The display system of claim 1, wherein the segmented waveplate selects first order diffracted light beams for projection onto the screen.

14. The display system of claim 1, wherein the segmented waveplate selects a zeroth order diffracted light beam for projection onto the screen.

15. The display system of claim 1, wherein the scanning element is placed at a Fourier plane of the projection lens system.

16. The display system of claim 1, wherein the polarization sensitive element is simultaneously used for delivery of light from the light source to the linear array and for passing the discrete number of selected diffracted light beams.

17. The display system of claim 1, wherein the projection lens system includes an intermediate image plane after the scanning element wherein a two-dimensional image is formed and is relayed to the screen.

18. An optical subsystem, comprising:

an electromechanical grating device that receives illumination from a light source;

a polarization sensitive element for passing diffracted light beams dependent on their polarization state; and

a segmented waveplate that alters the polarization state of a discrete number of selected diffracted light beams wherein the segmented waveplate is located between the electromechanical grating device and the polarization sensitive element.

19. The optical subsystem of claim 18, wherein the electromechanical grating device is a conformal grating device.

20. The optical subsystem of claim 18, wherein the electromechanical grating device is a grating light valve.

21. The optical subsystem of claim 18, wherein the electromechanical grating device receives linearly polarized illumination.

22. The optical subsystem of claim 21, wherein the segmented waveplate rotates the polarization state of the discrete number of selected diffracted light beams by ninety degrees with respect to the linearly polarized illumination while leaving the polarization state of other diffracted light beams unmodified.

23. The optical subsystem of claim 18, wherein the polarization sensitive element is a polarization beamsplitter that delivers illumination to the electromechanical grating device.

24. A printing system for printing on a light sensitive medium, comprising:

a light source providing illumination;

a linear array of electromechanical grating devices of at least two individually operable devices receiving the illumination wherein a grating period is oriented at a predetermined angle with respect to an axis of the linear array wherein the angle is large enough to separate diffracted light beams prior to a projection lens system that creates an image;

a polarization sensitive element that passes diffracted light beams dependent on their polarization state;

a segmented waveplate that alters the polarization state of a discrete number of selected diffracted light beams wherein the segmented waveplate is located between the linear array and the polarization sensitive element; and

a controller for providing a data stream to the individually operable devices.

25. The printing system of claim 24, wherein the linear array is constructed of electromechanical conformal grating devices.

26. The printing system of claim 24, wherein the linear array is constructed of electromechanical grating light valves.

27. The printing system of claim 24, wherein the predetermined angle is defined to be perpendicular to the axis of the linear array.

28. The printing system of claim 24, wherein the linear array receives linearly polarized illumination.

29. The printing system of claim 28, wherein the polarization sensitive element is a polarization beamsplitter that delivers the linearly polarized illumination to the linear array.

30. The printing system of claim 28, wherein the segmented waveplate rotates the polarization state of the discrete number of selected diffracted light beams by ninety degrees with respect to the linearly polarized illumination while leaving the polarization state of other diffracted light beams unmodified.

31. The printing system of claim 24, wherein the light source is of a single color.

32. The printing system of claim 24, wherein the light source produces a plurality of colors that are sequential in time and the controller is synchronized with the light source.

33. The printing system of claim 24, wherein the light source produces a plurality of colors at the same time and the printing system includes a corresponding number of linear arrays of electromechanical grating devices.

34. The printing system of claim 24, wherein the segmented waveplate further includes corresponding segmented regions that alter the polarization state of the selected diffracted light beams for each of the plurality of colors.

35. The printing system of claim 24 comprising at least three light sources and includes a corresponding number of linear arrays of electromechanical grating devices.

36. The printing system of claim 24, wherein the segmented waveplate selects first order diffracted light beams for printing on the light sensitive medium.

37. The printing system of claim 24, wherein the segmented waveplate selects a zeroth order diffracted light beam for printing on the light sensitive medium.

38. The printing system of claim 24, wherein the polarization sensitive element simultaneously delivers light from the light source to the linear array and passes the discrete number of selected diffracted light beams.