Broad gamut color display apparatus using an electromechanical grating device

• US 20040075817A1
• Filed: 10/16/2002
• Published: 04/22/2004
• Est. Priority Date: 10/16/2002
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Agostinelli, John A., Kowarz, Marek W., Horvath, Louis S.
• Granted Patent: US 6,802,613 B2
• Time in Patent Office: Days
• US Class Current: 353/34
• CPC Class Codes: H04N 9/3132 using one-dimensional electronic spatial light modulators

Abstract

An improved imaging apparatus having an expanded color gamut defined by more than three vertex colors for forming a color image on a display surface, that includes: a light source including at least one dichroic combiner for transmitting a first vertex color and reflecting a second vertex color toward a color combining element that directs, along an illumination axis, a colored illumination beam having, at any one time, any one of at least four different vertex colors; a linear array of electromechanical grating devices for receiving the colored illumination beam along the illumination axis; an obstructing element for blocking a zeroth order light beam reflected from the linear array of electromechanical grating devices from reaching the display surface; a projection lens cooperating with a scanning element, and a logic control processor.

Claims

1. An imaging apparatus having an expanded color gamut defined by more than three vertex colors for forming a color image on a display surface, comprising:

(a) a light source including at least one dichroic combiner for transmitting a first vertex color and reflecting a second vertex color toward a color combining element that directs, along an illumination axis, a colored illumination beam having, at any one time, any one of at least four different vertex colors;

(b) a linear array of electromechanical grating devices for receiving the colored illumination beam along the illumination axis;

(c) an obstructing element for blocking a zeroth order light beam reflected from the linear array of electromechanical grating devices from reaching the display surface;

(d) a projection lens cooperating with a scanning element for directing at least one diffracted light beam from the linear array of electromechanical grating devices toward the display surface, thereby forming a line image of the linear array on the display surface; and

(e) a logic control processor for controlling timing of the light source and for providing image data to the linear array of electromechanical grating devices.

2. The imaging apparatus having an expanded color gamut according to claim 1 wherein the linear array of electromechanical grating devices is taken from the group consisting of GLV and conformal GEMS devices.

3. The imaging apparatus having an expanded color gamut according to claim 1 wherein the display surface is selected from the group consisting of front projection screen and rear projection surface.

4. The imaging apparatus having an expanded color gamut according to claim 1 wherein the light source comprises a laser.

5. The imaging apparatus according to claim 1 further comprising a cross-order filter for blocking a plurality of diffracted cross-order light beams from reaching the display surface.

6. The imaging apparatus according to claim 1 wherein the obstructing element is also used for directing the colored illumination beam toward the linear array of electromechanical grating devices.

7. The imaging apparatus according to claim 1 wherein the color combining element is taken from the group consisting of X-cube and Philips prism.

8. The imaging apparatus according to claim 1 wherein the light source further comprises a second dichroic combiner for transmitting a third vertex color and reflecting a fourth vertex color toward the color combining element for forming the colored illumination beam.

9. The imaging apparatus according to claim 1 wherein the light source comprises color combining means for forming the illumination beam having any of the at least four different vetex colors.

10. The imaging apparatus according to claim 1 wherein the colored illumination beam is substantially monochromatic.

11. An imaging apparatus having a color gamut defined by more than three vertex colors for forming a color image on a display surface, comprising:

(a) a two-color modulation system for providing a first color modulated beam, the system comprising;

(a1) a first vertex color light source and a second vertex color light source;

(a2) a combiner for directing light from the first vertex color light source and the second vertex color light source along a common illumination axis to provide a color illumination beam;

(a3) a first linear array of electromechanical grating devices for diffracting, according to image data, the color illumination beam received along the common illumination axis, thereby forming the first color modulated beam;

(a4) an obstructing element for blocking a zeroth order light beam reflected, from the first color modulated beam, from reaching the display surface;

(b) control means for selectively energizing, at any one time, either the first vertex color light source or the second vertex color light source and providing, to the first linear array of electromechanical grating devices, the image data corresponding to the energized first or second color light source;

(c) a third vertex color light source directed toward a second linear array of electromechanical grating devices for diffracting light from the third vertex color light source to provide a second color modulated beam according to image data from the control means;

(d) a fourth vertex color light source directed toward a third linear array of electromechanical grating devices for diffracting light from the fourth vertex color light source to provide a third color modulated beam according to image data from the control means;

(e) a combiner for combining, along a single projection axis, the first, second, and third color modulated beams to form a multicolor modulated beam; and

(f) a projection lens cooperating with a scanning element for directing at least one diffracted light beam from the multicolor modulated beam toward the display surface, thereby forming a line image on the display surface.

12. The imaging apparatus according to claim 11 wherein the first, second, and third linear array of electromechanical grating devices are taken from the group consisting of GLV and conformal GEMS devices.

13. The imaging apparatus according to claim 11 wherein the display surface is selected from the group consisting of front projection screen and rear projection surface.

14. The imaging apparatus according to claim 11 wherein the first vertex color light source comprises a laser.

15. The imaging apparatus according to claim 11 further comprising a cross-order filter for blocking a plurality of diffracted cross-order light beams from reaching the display surface.

16. The imaging apparatus according to claim 11 wherein the obstructing element is also used for directing the colored illumination beam toward the first, second, or third linear array of electromechanical grating devices.

17. The imaging apparatus according to claim 11 wherein the first vertex color light source is substantially monochromatic.

18. An imaging apparatus having an expanded color gamut defined by more than three vertex colors for forming a color image as a series of lines on a display surface, comprising:

(a) a first two-color modulation system for providing a first alternate color modulated beam, the first two-color modulation system comprising;

(a1) a first vertex color light source and a second vertex color light source;

(a2) a first combiner for directing light from the first vertex color light source and the second vertex color light source along a first common illumination axis to provide a first illumination beam;

(a3) a first linear array of electromechanical grating devices for diffracting the first illumination beam received along the first common illumination axis according to image data;

(a4) a first obstructing element for blocking a first zeroth order light beam reflected from the first linear array of electromechanical grating devices from reaching the display surface;

 

control logic means selecting, at any one time, either the first vertex color light source or the second vertex color light source and for providing the image data corresponding to the first or the second vertex color light source;

(b) a second two-color modulation system for providing a second alternate color modulated beam, the second two-color modulation system comprising;

(b1) a third vertex color light source and a fourth vertex color light source;

(b2) a second combiner for directing light from the third vertex color light source and the fourth vertex color light source along a second common illumination axis to provide a second illumination beam;

(b3) a second linear array of electromechanical grating devices for diffracting the second illumination beam received along the second common illumination axis according to image data;

(b4) a second obstructing element for blocking a second zeroth order light beam reflected from the second linear array of electromechanical grating devices from reaching the display surface;

the control logic means enabling, at any one time, either the third vertex color light source or the fourth vertex color light source and for providing the image data corresponding to the third or the fourth vertex color light source;

(c) an imaging beam combiner for combining, as a final output color beam along a single projection axis, the first and second alternate color modulated beams; and

,

(d) a projection lens cooperating with a scanning element for directing at least one diffracted light beam from the final output color beam toward the display surface, thereby forming a line image on the display surface.

19. The imaging apparatus having an expanded color gamut according to claim 18 wherein the first linear array of electromechanical grating devices is taken from the group consisting of GLV and conformal GEMS devices.

20. The imaging apparatus having an expanded color gamut according to claim 18 wherein the display surface is selected from the group consisting of front projection screen and rear projection surface.

21. The imaging apparatus having an expanded color gamut according to claim 18 wherein the first vertex color light source comprises a laser.

22. The imaging apparatus having an expanded color gamut according to claim 18 wherein the first obstructing element is also used for directing the first illumination beam toward the first linear array of electromechanical grating devices.

23. The imaging apparatus having an expanded color gamut according to claim 18 wherein the imaging beam combiner is selected from the group consisting of X-cube and Philips prism.

24. The imaging apparatus having an expanded color gamut according to claim 18 wherein the first vertex color light source is substantially monochromatic.

25. An imaging apparatus having an expanded color gamut defined by more than three vertex colors for forming a color image as a series of lines scanned onto a display surface, comprising:

(a) a first vertex color light source directed toward a first linear array of electromechanical grating devices for diffracting light to provide a first color modulated beam;

(b) a second vertex color light source directed toward a second linear array of electromechanical grating devices for diffracting light to provide a second color modulated beam;

(c) a third vertex color light source directed toward a third linear array of electromechanical grating devices for diffracting light to provide a third color modulated beam;

(d) a fourth vertex color light source directed toward a fourth linear array of electromechanical grating devices for diffracting light to provide a fourth color modulated beam;

(e) a first combiner for combining the first and second color modulated beams to form a dual-color modulated beam;

(f) a second combiner for combining the dual-color modulated beam, the third color modulated beam and the fourth color modulated beams to form a multicolor modulated beam;

(g) a projection lens cooperating with a scanning element for directing at least one diffracted light beam from the multicolor modulated beam toward the display surface, thereby forming a line image on the display surface; and

(h) control means for providing image data to the first, second, third, and fourth linear arrays of electromechanical grating devices.

26. The imaging apparatus according to claim 25 wherein the first combiner is a polarizing beamsplitter.

27. The imaging apparatus according to claim 25 wherein the first combiner is a dichroic combiner.

28. The imaging apparatus according to claim 25 wherein the first vertex color light source comprises:

(a) a first laser having a first wavelength;

(b) a second laser having a second wavelength; and

(c) a dichroic mirror for reflecting light from the first laser and transmitting light from the second laser;

whereby both the first laser and the second laser contribute to the first vertex color light source.

29. The imaging apparatus according to claim 25 wherein the fourth vertex color light source comprises:

(a) a first laser having a first wavelength;

(b) a second laser having a second wavelength; and

(c) a dichroic mirror for reflecting light from the first laser and transmitting light from the second laser;

whereby both the first laser and the second laser contribute to the fourth vertex color light source.

30. The imaging apparatus according to claim 25 further comprising a compensator element for compensating for an optical path length difference.

31. The imaging apparatus having an expanded color gamut according to claim 25 wherein the second combiner is selected from the group consisting of X-cube and Philips prism.

32. A display apparatus having at least three colors, comprising:

(a) a first color light source that includes;

(i) a first laser having a first wavelength;

(ii) a second laser having a second wavelength; and

,

(iii) a dichroic mirror for reflecting light from the first laser and transmitting light from the second laser;

(b) control means that selectively energizes either;

(i) the first laser to provide a first vertex color at the first wavelength;

or,

(ii) the second laser to provide the first vertex color at the second wavelength;

or,

(iii) both the first and the second lasers to provide the first vertex color with increased brightness;

(c) a first modulator for modulating the first vertex color to provide a first color modulated beam;

(d) combining means for combining the first color modulated beam with one or more additional color modulated beams to form a multicolor modulated beam; and

,

(e) a projection lens for projecting the multicolor modulated beam toward a display surface.

33. The display apparatus according to claim 32 wherein the first modulator is a linear array of electromechanical grating devices.

34. The display apparatus according to claim 33 wherein the projection lens cooperates with a scanning element for directing the multicolor modulated beam toward the display surface, thereby forming a line image on the display surface.

35. An imaging apparatus for forming a color image on a display surface as an array of pixels, wherein each pixel can be formed using a combination of P colors or of P+1 colors, where P is an integer, the apparatus comprising:

(a) P+1 color light sources for providing source illumination;

(b) a control logic processor for obtaining image data for each pixel and, based on the image data, providing a control signal for enabling each of either P or P+1 color light sources; and

(c) one or more light modulators for modulating the source illumination from either the P or the P+1 color light sources to provide the color image.

36. The imaging apparatus for forming a color image according to claim 35 wherein P equals three.

37. The imaging apparatus for forming a color image according to claim 35 wherein the one or more light modulators are spatial light modulators.

38. The imaging apparatus for forming a color image according to claim 35 wherein the one or more light modulators are electromechanical grating light modulators.

39. A method for providing an expanded color gamut defined by more than three substantially monochromatic vertex colors for an imaging apparatus that forms a color image on a display surface, comprising:

(a) providing, along an illumination axis, a colored illumination beam having, at any one time, any of at least four different vertex colors;

(b) positioning a linear array of electromechanical grating devices for receiving the colored illumination beam along the illumination axis;

(c) blocking a zeroth order of a light beam reflected from the linear array of electromechanical grating devices from reaching the display surface;

(d) projecting a plurality of diffracted orders of the light beam toward a scanning element for directing the plurality of diffracted orders of the light beam toward the display surface; and

,

(e) controlling timing of the colored illumination beam and image data provided to the linear array of electromechanical grating devices.

40. A method for providing an imaging apparatus having an expanded color gamut defined by more than three substantially monochromatic vertex colors for forming a color image on a display surface, comprising:

(a) providing a two-color modulation system for forming a first color modulated beam along a single illumination axis, by;

(a1) providing a first vertex color light source and a second vertex color light source;

(a2) alternately directing light from the first vertex color light source and the second vertex color light source along a common illumination axis to provide a color illumination beam;

(a3) positioning a first linear array of electromechanical grating devices for diffracting the color illumination beam received along the common illumination axis, according to image data; and

(a4) blocking a zeroth order light beam reflected from the first linear array of electromechanical grating devices from reaching the display surface;

(b) providing a second color modulated beam by directing light from a third vertex color light source toward a second linear array of electromechanical grating devices for modulation according to the image data;

(c) providing a third color modulated beam by directing light from a fourth vertex color light source toward a third linear array of electromechanical grating devices for modulation according to the image data;

(d) combining, along a single projection axis, the first color modulated beam, the second color modulated beam, and the third color modulated beam to form a multicolor modulated beam; and

,

(e) projecting the multicolor modulated beam toward a scanning element to form successive lines of the color image on the display surface.

41. The method for providing an imaging apparatus having an expanded color gamut according to claim 40 wherein the step of alternately directing light from the first vertex color light source and from the second vertex color light source further comprises the step of periodically adjusting an alternating timing sequence.

42. A method for providing an imaging apparatus having an expanded color gamut defined by more than three substantially monochromatic vertex colors for forming a color image as a series of lines on a display surface, the method comprising:

(a) providing a first alternate color modulated beam by the steps of;

(a1) providing a first illumination beam by alternately directing light from a first vertex color light source and a second vertex color light source along a first common illumination axis;

(a2) providing color image data, according to the color of the first illumination beam, to a first linear array of electromechanical grating devices for diffracting the first illumination beam received along the first common illumination axis; and

(a3) blocking the zeroth order light beam reflected from the first linear array of electromechanical grating devices from reaching the display surface;

(b) providing a second alternate color modulated beam by the steps of;

(b1) providing a second illumination beam by alternately directing light from a third vertex color light source and a fourth vertex color light source along a second common illumination axis;

(b2) providing color image data, according to the color of the second illumination beam, to a second linear array of electromechanical grating devices for diffracting the second illumination beam received along the second common illumination axis; and

(b3) blocking the zeroth order light beam reflected from the second linear array of electromechanical grating devices from reaching the display surface;

(c) combining, as a final output color beam along a single projection axis, the first and second alternate color modulated beams; and

,

(d) projecting at least one diffracted light beam from the final output color beam toward a scanning element to direct the final output color beam toward the display surface as a line of image pixels.

43. The method for providing an imaging apparatus having an expanded color gamut according to claim 42 wherein the step of providing a first illumination beam further comprises the step of periodically adjusting an alternating timing sequence.

44. A method for providing an imaging apparatus having an expanded color gamut defined by more than three vertex colors for forming a color image as a series of lines on a display surface, the method comprising:

(a) forming a first color modulated beam by directing a first vertex color light source toward a first linear array of electromechanical grating devices for diffraction according to first color image data;

(b) forming a second color modulated beam by directing a second vertex color light source toward a second linear array of electromechanical grating devices for diffraction according to second color image data;

(c) forming a third color modulated beam by directing a third vertex color light source toward a third linear array of electromechanical grating devices for diffraction according to third color image data;

(d) forming a fourth color modulated beam by directing a fourth vertex color light source toward a fourth linear array of electromechanical grating devices for diffraction according to fourth color image data;

(e) combining the first and second color modulated beams to form a dual-color modulated beam;

(f) combining the dual-color modulated beam, the third color modulated beam and the fourth color modulated beams to form a multicolor modulated beam; and

,

(g) projecting at least one diffracted light beam from the multicolor modulated beam toward a scanning element to direct the at least one diffracted light beam toward the display surface as a line of image pixels.

45. A method for selectively forming a color pixel either using P vertex color light sources or P+1 vertex color light sources, the method comprising the steps of:

(a) providing a control signal for enabling each of either P or P+1 vertex color light sources as source illumination, based on an image data value for the color pixel; and

(b) providing image modulation data to one or more light modulators for modulating the source illumination from either the P or the P+1 vertex color light sources to provide a color image.

46. A method for selecting a color gamut including a first, a second, and a third vertex color, comprising the steps of:

(a) selecting the first vertex color from a first color light source;

(b) selecting the second vertex color from a second color light source; and

(c) selecting the third vertex color from a third color light source and a fourth color light source.

47. The method according to claim 46 wherein the third vertex color contains light simultaneously emitted from both the third and the fourth color light sources.

48. The method according to claim 46 wherein the third vertex color contains light emitted either from the third color light source or from the fourth color light source.

49. A method for increasing the brightness of a vertex color in an imaging apparatus, the method comprising:

(a) providing a first laser having a first wavelength;

(b) providing a second laser having a second wavelength; and

(c) providing a dichroic surface for reflecting light having the first wavelength and transmitting light having the second wavelength, whereby light from the first laser is combined with light from the second laser to form the vertex color.

50. In a display apparatus using at least three vertex colors, a method for providing a first vertex color comprising:

(a) providing a first laser having a first wavelength;

(b) providing a second laser having a second wavelength;

(c) providing a dichroic surface for reflecting light having the first wavelength and transmitting light having the second wavelength; and

(d) in response to a control command, either;

(i) energizing the first laser to use the first wavelength as a first vertex color;

or,

(ii) energizing the second laser to use the second wavelength as the first vertex color;

or,

(iii) energizing the first and the second lasers to provide the first vertex color having increased brightness.