Optics arrangements including light source arrangements for an active matrix liquid crystal image generator

• US 6,038,005 A
• Filed: 03/24/1998
• Issued: 03/14/2000
• Est. Priority Date: 12/22/1994
• Status: Expired due to Term

• Current Assignee: Citizen Finetech Miyota Company Limited (Citizen Electronics Company Limited)
• Original Assignee: DT FLCO, Inc. (Micron Technology, Inc.)
• Inventors: Handschy, Mark A., Meadows, Michael R., Chase, Holden
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): BURKE, MARGARET A
• Application Number:
  US09/046,898
• Time in Patent Office: 721 Days
• Field of Search: 359/619, 349/57, 349/58, 349/61, 349/68, 362/227, 362/230, 362/231, 362/236, 362/237, 362/240, 362/246, 362/800
• US Class Current: 349/61
• CPC Class Codes: G02B 27/1033 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1053 having a single light modulator for all colour channels
• CPC Class Codes: G02B 27/1086 operating by diffraction only
• CPC Class Codes: G02B 27/123 The splitting element being a lens or a system of lenses, including arrays and surfaces with refractive power
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 6/0033 Means for improving the coupling-out of light from the light guide
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02F 1/133526 Lenses, e.g. microlenses or Fresnel lenses
• CPC Class Codes: G02F 1/1336 Illuminating devices
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/133616 Front illuminating devices
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A system for producing modulated light is disclosed. The system comprises a spatial light modulator including a light modulating medium switchable between different states so as to act on light in ways which form overall patterns of modulated light. The system also includes an arrangement for switching the modulating medium between the different states in a controlled way and an illumination arrangement for producing a source of light. The system further includes an optics arrangement for directing light from the source of light into the spatial light modulator and for directing light from the spatial light modulator through a predetermined source imaging area. The optics arrangement cooperates with the illumination arrangement and the spatial light modulator so as to produce a real image of the source of light within the source imaging area such that an individual is able to view a virtual image of the overall patterns of modulated light from the source imaging area. A variety of novel optics arrangements are disclosed including specific combinations of different light sources, diffusing plates, polarizers, beam splitters, analyzers, lenses, mirrors, and holographic optical elements which allow the overall optical arrangement to be miniaturized to the same degree and in coordination with the spatial light modulator. The different light sources include using a plurality of light sources, such as LEDs, to form an array of light sources, each of the light sources providing light to a corresponding portion of the spatial light modulator.

Claims

1. A light source arrangement for use in a color field sequentially operated assembly for producing color sequential modulated light, said arrangement comprising a single dielectric substrate having on one surface thereof a pattern of electrically conductive leads adapted for connection to a source of electric power and a plurality of LED die of different colors individually attached to said substrate and electrically connected with said pattern of leads, said pattern of leads being adapted to allow said LED die of each of the different colors to be sequentially connected to the source of power.

2. A light source arrangement according to claim 1 including an equal plurality of collimating lenses, each of which is connected to said substrate and disposed optically over an associated one of said LED die.

3. A light source arrangement comprising a single LED wafer having a pattern of electrically conductive leads formed on one surface of said LED wafer, said leads dividing said LED wafer into a plurality of LED wafer regions, said leads being adapted for connection to a source of electric power in such a way that when said leads are connected to said source of electrical power, the leads distribute electrical power over the LED wafer to each of said LED wafer regions.

4. A light source arrangement according to claim 3 wherein said electrically conductive leads are opaque thereby dividing said wafer into a plurality of individual LED light sources.

5. A light source arrangement according to claim 4 including an equal plurality of collimating lenses, each of which is connected to said LED wafer and disposed optically over an associated one of said LEDs.

6. A light source arrangement according to claim 5 including a single substrate which is attached to said LED wafer and which is integrally formed to define all of said collimating lenses.

7. A light source arrangement for use in a field sequentially controlled assembly for producing modulated light, said arrangement comprising a single LED wafer having a pattern of opaque, transverse electrically conductive leads formed on one surface of said LED wafer, said leads being adapted for connection to a source of electric power, and said pattern of leads dividing said wafer into a plurality of individual LED light sources.

8. A light source arrangement according to claim 7 including an equal plurality of collimating lenses, each of which is connected to said LED wafer and disposed optically over an associated one of said LEDs.

9. A light source arrangement according to claim 8 including a single substrate which is attached to said LED wafer and which is integrally formed to define all of said collimating lenses.

10. A light source arrangement for use in a field sequentially controlled assembly for producing modulated light, said arrangement comprising:

(a) a single LED wafer having on one surface thereof a pattern of electrically conductive leads adapted for connection to a source of electric power, said leads dividing said LED wafer into a plurality of LED wafer regions in such a way that when said leads are connected to said source of electrical power, the leads distribute electrical power over the LED wafer to each of said LED wafer regions; and

(b) an equal plurality of collimating lenses, each of which is connected to said LED wafer and disposed optically over a predetermined segment thereof between the wafer and said field sequentially controlled assembly in a way which divides said wafer up into a plurality of LEDs.

11. A light source arrangement according to claim 10 including a single substrate which is attached to said LED wafer and which is integrally formed to define all of said collimating lenses.

12. A light source arrangement for use in a field sequentially operated assembly for producing modulated light, said arrangement comprising:

(a) a housing;

(b) a cluster of adjacently spaced light sources including light sources of different colors, all of which are sufficiently small so as to serve as point sources and each of which is spaced apart from any immediately adjacent light source a distance d, each of said light sources emitting light outwardly at a maximum angle A and being supported within said housing;

(c) a collimating lens located in front of said cluster of light sources and defining an outlet to said housing; and

(d) a diffusing plate disposed within said housing between said cluster of light sources and said collimating lens and located a distance L from the light sources where L is at least approximately equal to d/A.

13. A light source arrangement according to claim 12 wherein said light sources are red, green and blue LEDs.

14. A light source arrangement according to claim 13 wherein said light sources consist of two red, three green and two blue LEDs.

15. A light source arrangement according to claim 12 wherein said single collimating lens is a Fresnel lens.

16. A light source arrangement comprising:

(a) a housing;

(b) a cluster of adjacently spaced light sources including light sources of different colors, all of which are sufficiently small so as to serve as point sources and each of which is spaced apart from any immediately adjacent light source a distance d, each of said light sources emitting light outwardly at a maximum angle A and being supported within said housing;

(c) a collimating lens located in front of said cluster of light sources and defining an outlet to said housing; and

(d) a diffusing plate disposed within said housing between said cluster of light sources and said collimating lens and located a distance L from the light sources where L is at least approximately equal to d/A.

17. A light source arrangement according to claim 16 wherein said light sources are red, green and blue LEDs.

18. A light source arrangement according to claim 17 wherein said light sources consist of two red, three green and two blue LEDs.

19. A light source arrangement according to claim 16 wherein said single collimating lens is a Fresnel lens.

20. A light source arrangement comprising:

(a) a housing;

(b) a cluster of adjacently spaced light sources including light sources of different colors, each of said light sources emitting light outwardly from the light source within a given spread angle; and

(c) a diffusing plate positioned within said housing between said cluster of light sources and said collimating lens, the light sources being positioned a certain distance from the diffusing plate such that the light emitted from each of said light sources at said given spread angle illuminates a certain portion of said diffusing plate and such that each of the illuminated portions of said diffusing plate for each light source substantially overlaps the illuminated portions of the diffusing plate for the other light sources.

21. A light source according to claim 20 wherein the light source further includes a collimating lens located in front of said cluster of light sources and defining an outlet to said housing.

22. A light source arrangement according to claim 20 wherein said light sources are red, green and blue LEDs.

23. A light source arrangement according to claim 21 wherein said light sources consist of two red, three green and two blue LEDs.

24. A light source arrangement according to claim 20 wherein said single collimating lens is a Fresnel lens.

25. A light source arrangement for use in a color field sequentially operated assembly for producing color sequential modulated light, said arrangement comprising:

a single dielectric substrate having on one surface thereof a pattern of electrically conductive leads adapted for connection to a source of electric power;

a plurality of LEDs of different colors individually attached to said substrate and electrically connected with said pattern of leads in such a way to allow said LED die of each of the different colors to be sequentially connected to the source of power; and

an equal plurality of collimating lenses, each of which is connected to said substrate and disposed optically over an associated one of said LEDs.