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

• US 6,195,136 B1
• Filed: 10/21/1999
• Issued: 02/27/2001
• 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): Parker, Kenneth
• Application Number:
  US09/422,815
• Time in Patent Office: 495 Days
• Field of Search: 349/9, 349/5, 349/11, 359/631, 359/639, 359/363, 359/629, 359/630, 359/487, 359/495, 359/638, 359/640, 359/534, 353/33, 353/81, 353/30
• US Class Current: 349/5
• 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 display system for producing modulated light which may be viewed by a viewer, the display system comprising:

(a) 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;

(b) means for switching said modulating medium between said different states in a controlled way;

(c) illumination means for producing a source of light; and

(d) optics means for directing light from said source of light into said spatial light modulator and for directing light from said spatial light modulator through a predetermined source imaging area, said optics means cooperating with said illumination means and said spatial light modulator so as to produce a real image of said source of light within said source imaging area such that a virtual image of only said overall patterns of modulated light produced by said spatial light modulator is directly visible by said viewer from said source imaging area, said optics means including a curved surface beam splitter for directing at least a portion of the light from the source of light into the spatial light modulator.

2. A system according to claim 1 wherein the spatial light modulator is a reflective type spatial light modulator and wherein said optics means cooperates with said illumination means and said spatial light modulator such that some of the light directed from said illumination means to said spatial light modulator overlaps with some of the light passing from said spatial light modulator to said source imaging area.

3. A system according to claim 1 wherein said spatial light modulator is a reflective type spatial light modulator.

4. A system according to claim 3 wherein said curved surface beam splitter is optically disposed between both said source of light and said spatial light modulator and between said spatial light modulator and said source imaging area so as to direct light from said source of light to said spatial light modulator and from said spatial light modulator to said source imaging location.

5. A system according to claim 4 wherein said optics means further includes a polarizer positioned optically between said source of light and said spatial light modulator and an analyzer positioned optically between said spatial light modulator and said source imaging area.

6. A system according to claim 4 wherein said curved surface beam splitter is a curved surface polarizing beam splitter.

7. A system according to claim 6 wherein said optics means further includes an auxiliary polarizer optically disposed between said source of light and said curved surface polarizing beam splitter.

8. A system according to claim 7 wherein said optics means further includes an auxiliary analyzer optically disposed between said curved surface polarizing beam splitter and said source imaging location.