Three dimensional projection display reflecting divided polarized light on to reflective liquid crystal display elements

• US 5,552,840 A
• Filed: 03/11/1993
• Issued: 09/03/1996
• Est. Priority Date: 03/13/1992
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Ishii, Yutaka, Yamamoto, Yoshitaka
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): Cohen, Cheryl
• Application Number:
  US08/031,175
• Time in Patent Office: 1,272 Days
• Field of Search: 348/58, 348/742, 348/743, 348/70, 348/751, 348/752, 348/790, 348/53, 348/42, 348/51, 348/58
• US Class Current: 348/751
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: H04N 13/189 Recording image signals; Reproducing recorded image signals
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/324 Colour aspects
• CPC Class Codes: H04N 13/337 using polarisation multiplexing
• CPC Class Codes: H04N 13/363 using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 13/398 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10

Abstract

The present invention relates to a projection type liquid crystal display. In a preferred aspect, the projection type liquid crystal display of the invention includes an optical source for generating light, a light dividing unit which divides the light into a first light having a first polarization direction and a second polarization direction and allows the first and second lights to come out in different directions from each other, a pair of reflective liquid crystal display elements formed of a first reflective liquid crystal display element and a second reflective liquid crystal display element with synchronization, a light synthesizing unit for receiving the first light which comes out of the first reflective liquid crystal display element and the second light which comes out of the second reflective liquid crystal display element and synthesizing the first and second lights into image light, and a screen.

Claims

1. A projection type liquid crystal display comprising:

an optical source for generating light;

a light dividing means which divides the light into a first light having a first polarization direction and a second light having a second polarization direction, and allows the first and second lights to come out in different directions from each other;

a pair of reflective liquid crystal display elements formed of a first reflective liquid crystal display element and a second reflective liquid crystal display element, each of the pair of reflective liquid crystal display elements including a pair of substrates facing each other and liquid crystal sealed between the pair of substrates, the first reflective liquid crystal display element changing the first polarization direction of the first light by the liquid crystal sealed therein to allow the first light to come out thereof, and the second reflective liquid crystal display element changing the second polarization direction of the second light by the liquid crystal sealed therein to allow the second light to come out thereof;

a driving means for driving the first reflective liquid crystal display element and the second reflective liquid crystal display element with synchronization;

a light synthesizing means for receiving the first light which comes out of the first reflective liquid crystal display element and the second light which comes out of the second reflective liquid crystal display element, and synthesizing the first and second lights into image light; and

a screen on which the image light is displayed.

2. A projection type liquid crystal display according to claim 1, wherein the light synthesizing means also functions as the light dividing means.

3. A projection type liquid crystal display according to claim 1, wherein the light dividing means is a beam splitter.

4. A projection type liquid crystal display according to claim 1, further comprising a light selection means for converting the light from the optical source into either one of a red light, a green light, and a blue light.

5. A projection type liquid crystal display according to claim 4, wherein the light selection means is formed of a cyan filter, a magenta filter, and a yellow filter.

6. A projection type liquid crystal display according to claim 5, wherein the cyan filter, the magenta filter, and the yellow filter have a pair of transparent substrates facing each other and liquid crystal sealed between the pair of transparent substrates, respectively.

7. A projection type liquid crystal display according to claim 4, wherein the light selection means is a mechanical R.G.B. rotary filter.

8. A projection type liquid crystal display according to claim 1, wherein the first liquid crystal display element and the second liquid crystal display element have a plurality of pixels and color filters formed on each pixel, respectively.

9. A projection type liquid crystal display according to claim 1, wherein at least one of the pair of substrates is a transparent substrate, and the first light or the second light are incident upon the transparent substrate.

10. A projection type liquid crystal display according to claim 9, wherein the pair of reflective liquid crystal display elements further have a reflection means and a non-reflection means, the reflection means is formed facing the transparent substrate and reflects the first light or the second light, and the non-reflection means is formed on the side of the transparent substrate upon which the first light or the second light is incident.

11. A projection type liquid crystal display according to claim 1, wherein one substrate of the pair of substrates is a silicon substrate, and the driving means is formed on the silicon substrate.

12. A projection type liquid crystal display according to claim 11, wherein the pair of reflective liquid crystal display elements have a plurality of pixels, respectively, and the driving means is formed on a back face of the plurality of pixels.

13. A projection type liquid crystal display according to claim 11, wherein the pair of reflective liquid crystal display elements have a display portion formed of the plurality of pixels and the driving means is formed in the periphery of the display portion.

14. A projection type liquid crystal display according to claim 1, wherein an angle formed by the first polarization direction and the second polarization direction is in the range of 45°

to 135°

.

15. A projection type liquid crystal display according to claim 1, wherein the first light having the first polarization direction is an S-polarized light, the second light having the second polarization direction is a P-polarized light, and the liquid crystal converts the S-polarized light into light having a P-polarized component and the P-polarized light into light having an S-polarized component.

16. A projection type liquid crystal display according to claim 4, wherein the light selection means is driven to selectively convert the light from the optical source into ones of the red light, the green light, and the blue light in a time divisional manner.

17. A projection type liquid crystal display according to claim 5, wherein the cyan filter, the magenta filter and the yellow filter are selectively driven to convert the light from the optical source into selected ones of the red light, the green light, and the blue light in a time divisional manner.

18. A projection type liquid crystal display according to claim 1, wherein the display can perform a non-three-dimensional display.

19. A projection type liquid crystal display according to claim 15, wherein the display can perform a non-three-dimensional display using both the P-polarized component and the S-polarized component.

20. A projection type liquid crystal display according to claim 1, wherein the display does not include a cathode ray tube in addition to the optical source.