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

• US 8,130,439 B2
• Filed: 10/31/2007
• Issued: 03/06/2012
• Est. Priority Date: 12/22/1994
• Status: Expired due to Fees

• Current Assignee: Citizen Finetech Miyota Company Limited (Citizen Electronics Company Limited)
• Original Assignee: Micron Technology, Inc.
• Inventors: Chase, Holden, Handschy, Mark A, Meadows, Michael R
• Primary Examiner(s): Martinez, Joseph P
• Application Number:
  US11/932,447
• Publication Number:
  US 20080062351A1
• Time in Patent Office: 1,588 Days
• Field of Search: 359/290, 349/129, 349/123, 349/124, 349/130
• US Class Current: 359/290
• 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 lights 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 display system, comprising:

an LED illuminator that provides light of at least three colors; and

an array of pixels that are illuminated by the LED illuminator, the pixels being switchable between optical states, in approximately 2 milliseconds or less;

wherein the array of pixels and the LED illuminator are controlled to sequentially display first an image of one of the at least three colors, followed by an image of a second one of the at least three colors, followed by an image of a third one of the at least three colors, in order to form a color gray-scale image.

2. A display system as defined in claim 1, wherein the array of pixels are part of a microdisplay.

3. A display system as defined in claim 2, wherein the microdisplay is a reflective microdisplay.

4. A display system as defined in claim 2, wherein the microdisplay is a liquid-crystal microdisplay.

5. A display system as defined in claim 2, wherein the microdisplay is a ferroelectric liquid-crystal microdisplay.

6. A display system as defined in claim 1, wherein the LED illuminator includes 3 LEDs.

7. A display system as defined in claim 6, wherein the LED illuminator includes a red LED, a green LED, and a blue LED.

8. A display system as defined in claim 1, further including an optical element to focus the light from the pixels.

9. A display system as defined in claim 1, further including an optical element to create a magnified image of the pixel array.

11. A display system as defined in claim 1, further including optical elements that create a real image of at least a portion of the LED illuminator from the light provided by the illuminator.

12. A display system as defined in claim 11, wherein the real image is created from light that has passed through or been reflected by the array of pixels.

13. A display system as defined in claim 3, wherein the microdisplay is a liquid-crystal microdisplay.

14. A display system as defined in claim 13, wherein the microdisplay is a ferroelectric liquid-crystal microdisplay.

15. A display system as defined in claim 3, wherein the array of pixels is embodied on a semiconductor substrate.

16. A display system as defined in claim 1, wherein the array of pixels change their optical state without mechanical motion.

17. A display system as defined in claim 1, wherein voltages applied to the pixels in the array of pixels to control the optical state thereof are 5 volts or less.

18. A display system as defined in claim 1, wherein the array of pixels includes rows of pixels and wherein the rows have a pitch of 10 μ

m or less.

19. A display system as defined in claim 1, wherein at least a portion of the time that the optical state of the pixels is changed, the change is made while the illuminator is illuminating the pixels.

20. A display system as defined in claim 1, wherein the controlling is performed in such a way that at least some of the pixels switch between optical states while illuminated.

21. A display system as defined in claim 1, wherein the pixels are switchable between electrical states and wherein the optical state of each pixel is determined solely by its present electrical state.

22. A display system as defined in claim 21, wherein each pixel is switchable between only two electrical states.

10. A display system, comprising:

an LED illuminator that provides light of at least three colors;

an array of pixels that are illuminated by the LED illuminator, the pixels being switchable between optical states, in approximately 2 milliseconds or less; and

an optical element to create a magnified image of the pixel array;

wherein the array of pixels and the LED illuminator are controlled to sequentially display color gray-scale images;

wherein the optical element includes an eyepiece lens.

23. A display system, comprising:

an LED illuminator that provides light of at least three colors; and

an array of pixels that are illuminated by the LED illuminator at least approximately 50 percent of the time that the display system is operating;

wherein the array of pixels and the LED illuminator are controlled to sequentially display first an image of one of the at least three colors, followed by an image of a second one of the at least three colors, followed by an image of a third one of the at least three colors, in order to form a color gray-scale image.