Electro-optical device

• US 5,666,173 A
• Filed: 04/28/1994
• Issued: 09/09/1997
• Est. Priority Date: 01/17/1991
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Mase, Akira, Yamazaki, Shunpei
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Dudek, James A.
• Application Number:
  US08/233,983
• Time in Patent Office: 1,230 Days
• Field of Search: 359/53, 359/48, 359/84, 359/85, 345/102, 345/88, 345/89, 349/61, 349/68, 349/69, 349/70, 349/71
• US Class Current: 349/61
• CPC Class Codes: G02F 1/1347 Arrangement of liquid crystal layers or cells in which the final condition of one light beam is achieved by the addition of the effects of two or more layers or cells
• CPC Class Codes: G02F 2203/30 Gray scale
• CPC Class Codes: G09G 2300/0823 used to establish symmetry in driving, e.g. with polarity inversion
• CPC Class Codes: G09G 2310/0235 Field-sequential colour display
• CPC Class Codes: G09G 2310/06 Details of flat display driving waveforms
• CPC Class Codes: G09G 2320/0633 by amplitude modulation of the brightness of the illumination source
• CPC Class Codes: G09G 3/002 to project the image of a two-dimensional display, such as an array of light emitting or modulating elements or a CRT
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2025 the sub-frames having all the same time duration
• CPC Class Codes: G09G 3/2074 using sub-pixels
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/364 with use of subpixels
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3651 using multistable liquid crystals, e.g. ferroelectric liquid crystals
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• 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
• CPC Class Codes: H04N 9/3126 for spatial light modulators in series

Abstract

An electro-optical apparatus comprising a pair of first and second devices, which are provided in an optical path extending from a light source and a screen for outputting a picture image thereon, the first and second devices each including a pair of first and second substrates each having electrodes and leads formed thereon, which sandwich therebetween an electro-optical modulating layer (comprising for example a liquid crystal composition) and a means for orienting the liquid crystal composition at least in an initial stage. The light transmission factor of the second device changes with time rotationally in the ratios of approximately 2⁰ to 2¹ to 2² to . . . to 2ⁿ (n is an arbitrary natural number). Thus, it is possible to realize tonal display, reduce the overall weight of the apparatus and improve the yield.

Claims

1. An electro-optical device comprising:

a light source for emitting a light having a constant intensity,

a panel comprising an electro-optical modulating layer for modulating an intensity of the light emitted into said panel from said light source by applying an electric field to said electro-optical modulating layer; and

means for varying an intensity of the light transmitted by said panel in a repeating cycle,

wherein said intensity of the light transmitted by said panel can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² ;

. . . ;

2ⁿ where n is a natural number, and

wherein said panel comprises a pair of substrates sandwiching said electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

2. A device of claim 1 wherein said electro-optical modulating layer comprises a liquid crystal.

3. The device of claim 1 wherein said electro-optical modulating layer comprises a liquid crystal and a resin.

4. The device of claim 3 wherein said resin comprises a photo-setting acrylic resin.

5. An electro-optical device comprising:

a panel comprising an electro-optical modulating layer for modulating an intensity of the light emitted into said panel by applying an electric field to said electro-optical modulating layer; and

means for varying an intensity of the light reflected by said panel in a repeating cycle,

wherein said intensity of the light reflected by said panel can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² ;

. . . ;

2ⁿ where n is a natural number, and

wherein said panel comprises a pair of substrates sandwiching said electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

6. The device of claim 5 wherein said electro-optical modulating layer comprises a liquid crystal.

7. The device of claim 5 wherein said electro-optical modulating layer comprises a liquid crystal and a resin.

8. The device of claim 7 wherein said resin comprises a photo-setting acrylic resin.

9. An electro-optical device comprising:

a light source for emitting a light having a constant intensity;

a first panel comprising a first electro-optical modulating layer for modulating an intensity of the light emitted into said first panel from said light source by applying an electric field to said first electro-optical modulating layer;

a second panel comprising a second electro-optical modulating layer for modulating an intensity of the light emitted into said second panel from said light source by applying an electric field to said second electro-optical modulating layer;

a third panel comprising a third electro-optical modulating layer for modulating an intensity of the light emitted into said third panel from said light source by applying an electric field to said third electro-optical modulating layer; and

means for varying an intensity of the light transmitted in parallel by said first, second and third panels in a repeating cycle,

wherein said intensity of the light transmitted by said first, second and third panels can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² ;

. . . ;

2ⁿ in each of said first, second and third panels where n is a natural number, and

wherein each of said first, second and third panels comprises a pair of substrates sandwiching the corresponding electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

10. The device of claim 9 wherein each of said first, second and third electro-optical modulating layers comprises a liquid crystal.

11. The device of claim 9 wherein each of said first, second and third electro-optical modulating layers comprises a liquid crystal and a resin.

12. The device of claim 11 wherein said resin comprises a photo-setting acrylic resin.

13. An electro-optical device comprising:

a light source for emitting a light having a constant intensity;

a first panel comprising a first electro-optical modulating layer for modulating an intensity of the light emitted into said first panel from said light source by applying an electric field to said first electro-optical modulating layer;

a second panel comprising a second electro-optical modulating layer for modulating an intensity of the light emitted into said second panel from said light source by applying an electric field to said second electro-optical modulating layer;

a third panel comprising a third electro-optical modulating layer for modulating an intensity of the light emitted into said third panel from said light source by applying an electric field to said third electro-optical modulating layer; and

means for varying an intensity of the light reflected in parallel by said first, second and third panels in a repeating cycle,

wherein said intensity of the light reflected by said first, second, and third panels can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² ;

. . . ;

2ⁿ in each of said first, second and third panels where n is a natural number, and

wherein each of said first, second and third panels comprises a pair of substrates sandwiching the corresponding electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

14. The device of claim 13 wherein each of said first, second and third electro-optical modulating layers comprises a liquid crystal.

15. The device of claim 13 wherein each of said first, second and third electro-optical modulating layers comprises a liquid crystal and a resin.

16. The device of claim 15 wherein said resin comprises a photo-setting acrylic resin.

17. An electro-optical device comprising:

a panel comprising an electro-optical modulating layer and means for applying an electric field to said electro-optical modulating layer; and

means for varying an intensity of light transmitted by said panel by controlling light transmission characteristics of the panel in a repeating cycle,

where said intensity can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² . . . 2ⁿ where n is a natural number, and

wherein said panel comprises a pair of substrates sandwiching said electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

18. An electro-optical device comprising:

a panel comprising an electro-optical modulating layer and means for applying an electric field to said electro-optical modulating layer; and

means for varying an intensity of light reflected by said panel by controlling light transmission characteristics of the panel in a repeating cycle,

wherein said intensity can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² . . . 2ⁿ where n is a natural number, and

wherein said panel comprises a pair of substrates sandwiching said electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

19. An electro-optical device comprising:

a first panel comprising a first electro-optical modulating layer and means for applying an electric field to said first electro-optical modulating layer;

a second panel comprising a second electro-optical modulating layer and means for applying an electric field to said second electro-optical modulating layer;

a third panel comprising a third electro-optical modulating layer and means for applying an electric field to said third electro-optical modulating layer; and

means for varying an intensity of light transmitted in parallel by said first, second, and third panels in a repeating cycle by controlling light transmission characteristic of the first, second, and third panels

wherein said intensity can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² . . . 2ⁿ in each of said first, second, and third panels where n is a natural number, and

wherein each of said first, second and third panels comprises a pair of substrates sandwiching the corresponding electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.

20. An electro-optical device comprising:

a first panel comprising a first electro-optical modulating layer and means for applying an electric field to said first electro-optical modulating layer;

a second panel comprising a second electro-optical modulating layer and means for applying an electric field to said second electro-optical modulating layer;

a third panel comprising a third electro-optical modulating layer and means for applying an electric field to said third electro-optical modulating layer; and

means for varying an intensity of light reflected in parallel by said first, second, and third panels by controlling light transmission characteristics of the first, second, and third panels in a repeating cycle,

wherein said intensity can be varied with time rotationally at a ratio of 2⁰ ;

2¹ ;

2² . . . 2ⁿ in each of said first, second, and third panels where n is a natural number, and

wherein each of said first, second and third panels comprises a pair of substrates sandwiching the corresponding electro-optical modulating layer therebetween, and one of said substrates has a single electrode provided thereon, and the other of said substrates has a parallel electrode part comprising at least two parallel electrodes provided on the other of said substrates.