Display panel and projection display system with use of display panel

• US 6,005,651 A
• Filed: 01/16/1996
• Issued: 12/21/1999
• Est. Priority Date: 08/04/1992
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takahara, Hiroshi, Mochizuki, Hideaki, Ohmae, Hideki
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Ngo, Julie
• Application Number:
  US08/586,418
• Time in Patent Office: 1,435 Days
• Field of Search: 359/52, 359/66, 359/98, 359/96, 359/40, 359/41, 359/67, 359/68, 359/51, 359/71, 359/74, 359/59, 359/87, 349/7, 349/8, 349/10, 349/35, 349/41, 349/42, 349/44, 349/86, 349/106, 349/110, 349/138, 349/139, 349/162, 349/137
• US Class Current: 349/137
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 1/133502 Antiglare, refractive index matching layers
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605

Abstract

In a display panel, a first substrate is opposed to a second substrate and interposing a liquid crystal/resin composite layer. If the display panel is a transmission type display, a film for absorbing light is formed on a black matrix and between pixel electrodes. If the display panel is a reflection type display, a film for absorbing light is formed between reflection electrodes. Further, a counterelectrode is made from a multi-layer film of dielectric films and a transparent electrically conductive film for preventing reflection. The film for absorbing light includes pigments which can absorb light modulated by the liquid crystal/resin composite layer. By using the display panel, a projection display system of high contrast and high brightness can be constructed.

Claims

1. A liquid crystal display panel comprising:

a first substrate on which pixel electrodes arranged as a matrix and signal lines for applying signals to the pixel electrodes are formed;

a second substrate on which a counter electrode is formed;

an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state thereof; and

a light absorbing member formed on said signal lines, said light-absorbing member comprising a resin material capable of absorbing light scattered in said optical modulation layer.

2. The liquid crystal panel according to claim 1, wherein said optical modulation layer comprises a liquid crystal/resin composite including a liquid crystal component and a resin component, said optical modulation layer has a thickness between 5 and 25 μ

m, a ratio of the liquid crystal component in the composite is set to be between 50 and 85 wt %, the resin component of the composite comprises a photosetting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal.

3. A liquid crystal panel comprising:

first and second electrode substrates, at least one of the first and second electrode substrates being made of a transparent material;

an optical modulation layer interposed between said first and second electrode substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state;

a first light-absorbing member formed on at least one of said first and second electrode substrates on a plane in contact with said optical modulation layer, said light-absorbing member being capable of absorbing light scattered in said optical modulation layer;

a transparent plate;

an optical coupling layer coupling optically said transparent plate to said at least one of said first and second electrode substrates; and

a second light-absorbing member formed in an area of said transparent plate in which light effective for displaying an image does not propagate.

4. The liquid crystal panel according to claim 3, wherein said transparent plate comprises a concave lens.

5. The liquid crystal panel according to claim 3, wherein said optical modulation layer comprises a liquid crystal/resin composite including a liquid crystal component and a resin component, said optical modulation layer has a thickness between 5 and 25 μ

m, a ratio of the liquid crystal component in the composite is set to be between 50 and 85 wt %, the resin component of the composite comprises a photosetting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal.

6. The liquid crystal display panel according to claim 3, wherein parameters of the panel are such that a following relation:

##EQU5## holds where "n" denotes an index of refraction of said transparent plate, "t" denotes a total thickness of said transparent plate in units of millimeters and said at least one of said first and second electrode substrates at a center thereof, and "d" denotes a diagonal length of an effective display area of the liquid crystal panel in units of millemeters.

7. A liquid crystal display panel comprising:

a first substrate above which reflection electrodes arranged as a matrix are formed, switching elements connected to the reflection electrodes being formed between the reflection electrodes and said first substrate;

a second substrate on which a counter electrode and a dielectric film made of an inorganic material so as to have an anti-reflection function are formed;

a liquid crystal layer interposed between said first and second substrates; and

a light-shielding film formed between the reflection electrodes capable of preventing light from entering from said liquid crystal layer to the switching elements.

8. The liquid crystal panel according to claim 7, wherein said reflection electrodes are made of a metallic material, said reflection electrodes are formed on electrically insulating films formed on the switching elements, said liquid crystal layer comprises a liquid crystal/resin composite including a liquid crystal component and a resin component, said liquid crystal layer has a thickness between 5 and 25 μ

m, a ratio of the liquid crystal component in the composite is set between 50 and 85 wt %, the resin component of the composite comprises a photo setting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal.

9. The liquid crystal panel according to claim 7, wherein said dielectric layer is made of one of aluminum oxide (Al₂ O₃), yttrium oxide (Y₂ O₃) and silicon oxide (SiO).

12. The display according to claim 9, wherein said optical modulation layer comprises a liquid crystal/resin composite including a liquid crystal component and a resin component, said optical modulation layer has a thickness between 5 and 25 μ

m, a ratio of the liquid crystal component in the composite is set to be between 50 and 85 wt %, the resin component of the composite comprises a photosetting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal.

14. The display according to claim 12, wherein said reflection electrodes are made of a metallic material, said reflection electrodes are formed on electrically insulating films formed on the switching elements, said liquid crystal layer comprises a liquid crystal/resin composite including a liquid crystal component and a resin component, said optical modulation layer has a thickness between 5 and 25 μ

m, a ratio of the liquid crystal component in the composite is set to be between 50 and 85 wt %, the resin component of the composite comprises a photosetting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal.

10. A projection type liquid crystal display comprising:

a display panel comprising;

a first substrate on which pixel electrodes arranged as a matrix are formed, a second substrate on which a counter electrode is formed, an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state, and a light-absorbing film formed on a light-shielding layer formed on said counter electrode and being in contact with said optical modulation layer;

a light source for generating a light beam;

an optical system for guiding the light beam generated by said light source to said display panel; and

a projection device for projecting light modulated by said display panel.

11. The display according to claim 10, wherein said light-absorbing member comprises a film made of a resin including pigments capable of absorbing light modulated by said optical modulation layer.

13. A projection type liquid crystal display comprising:

a display panel comprising;

a first substrate above which reflection electrodes arranged as a matrix are formed, switching elements connected to the reflection electrodes being formed between the reflection electrodes and said first substrate, a second substrate on which a counter electrode and a dielectric film made of an inorganic material so as to have an anti-reflection function are formed, a liquid crystal layer interposed between said first and second substrates, and a light-shielding film formed between the reflection electrodes capable of preventing light from entering from said liquid crystal layer to the switching elements;

a light source for generating a light beam;

an optical system for guiding the light beam generated by said light source to said display panel; and

a projection device for projecting light modulated by said display panel.

15. A projection type liquid crystal display comprising:

a plurality of optically addressed display panels, each of the display panels comprising;

a first substrate on which an electrically conducting layer is formed, a second substrate on which a transparent counter electrode and at least one dielectric layer are formed so as to form an anti-reflection layer, an optical modulation layer capable of forming an optical image due to a change of an optical scattering state interposed between said first and second substrates, and a light absorbing member formed on at least one of said first and second substrates on a plane in contact with said optical modulation layer, the light-absorbing member being capable of absorbing light scattered by said optical modulation layer;

a light source for generating a light beam;

an optical system for guiding the light beam generated by said light source to said display panels; and

a projection device for projecting light modulated by said display panels.

16. A projection type liquid crystal display comprising:

a plurality of display panels, each of said display panels comprising;

a first substrate having thereon pixel electrodes arranged as a matrix and signal lines for applying signals to the pixel electrodes, a second substrate on which a counter electrode is formed, an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of optical scattering state, and a light-absorbing member formed on said signal lines;

wherein said plurality of display panels comprise a first display panel for modulating red, a second display panel for modulating green and a third display panel for modulating yellow;

wherein said optical modulation layer of each of said plurality of display panels comprises a liquid crystal component and a resin component;

wherein said optical modulation layer of said first display panel has a condition selected from the group consisting of

     1) a droplet size of the liquid crystal component being larger than the droplet size of the liquid crystal component of said second and third display panels, and

     2) a pore size of the resin component being larger than the pore size of the resin component of said second and third display panels;

a light source for generating a light beam;

an optical system for guiding the light beam generated by said light source to said display panels; and

a projection device for projecting a light modulated by said display panels.

17. A liquid crystal display panel comprising:

a first substrate on which pixel electrodes are arranged as a matrix;

a second substrate on which a counter electrode is formed;

an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state; and

a light absorbing member for absorbing light scattered in said optical modulation layer, said light absorbing member being formed on said counter electrode to have an anti-reflection function.

18. A liquid crystal display panel comprising:

a first substrate on which pixel electrodes arranged as a matrix are formed;

a second substrates on which a counter electrode and a black matrix are formed;

an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state; and

a light-absorbing member formed on said black matrix, said light-absorbing member comprising a resin material capable of absorbing light scattered in said optical modulation layer.

19. The liquid crystal display panel according to claim 18, wherein said optical modulation layer comprises a liquid crystal/resin composite including a liquid crystal component and a resin component, said optical modulation layer has a thickness between 5 and 25 μ

m, the liquid crystal component of the composite is set to be between 50 and 85 wt %, the resin component of the composite comprises a photosetting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal.

20. A liquid crystal display panel comprising:

a first substrate on which transparent pixel electrodes arranged as a matrix are formed;

a second substrate on which a counter electrode made of a transparent conductive material and at least one dielectric layer are layered so as to form an anti-reflection film;

an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state; and

a light-absorbing member formed between the pixel electrodes for absorbing light scattered in said optical modulation layer.

21. The liquid crystal panel according to claim 20, wherein said light-absorbing member comprises a film made of a resin comprising pigments for absorbing light modulated by said optical modulation layer.

22. The liquid crystal panel according to claim 20 wherein:

said at least one dielectric film is made of an inorganic material of Al₂ O₃, Y₂ O₃ or SiO so as to form an anti-reflection layer;

said optical modulation layer has a thickness between 5 and 25 μ

m, and the liquid crystal component of the composite is set to be between 50 and 85 wt %; and

the at least one dielectric film has an optical thickness of about λ

/4, and said transparent, electrically conducting material has an optical thickness selected from the group consisting of about λ

/2 and about λ

/4, where λ

denotes a main wavelength of incident light.

23. An optically addressed liquid crystal display panel comprising,

a first substrate having electrically conductive layers formed thereon;

a second substrate having thereon a transparent counter electrode and at least one dielectric layer layered so as to form an anti-reflection film;

an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state; and

a light-absorbing member formed on at least one of said first and second substrates on a plane in contact with said optical modulation layer, said light-absorbing member being capable of absorbing light scattered in said optical modulation layer.

24. The panel according to claim 23, wherein said light-absorbing member is formed in stripe patterns.

25. A projection type liquid crystal display comprising:

a plurality of a display panels each comprising;

a first substrate having reflection electrodes arranged thereon as a matrix, a second substrate having a counter electrode and at least one dielectric layer made of an inorganic material and layered thereon so as to form an anti-reflection film, an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state, and a light absorbing member formed on at least one of said first and second substrates on a plane in contact with said optical modulation layer for absorbing light scattered in said optical modulation layer;

a light source for generating a light beam;

an optical system for guiding the light beam generated by said light source to said display panel; and

a projection device for projecting light modulated by said display panel.

26. The display according to claim 25, wherein said light-absorbing member comprises a film made of a resin including pigments capable of absorbing light modulated by said optical modulation layer.

27. A projection type liquid crystal display comprising:

a plurality of optically addressed display panels, each of said display panels comprising;

a first substrates having reflection electrodes arranged thereon as a matrix and signal lines thereon for applying signals to the reflection electrodes, a second substrate having a counter electrode and at least one dielectric layer thereon so an to form an anti-reflection layer, an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state, and a light-absorbing member formed between said reflection electrodes, said light-absorbing member being capable of absorbing light scattered in said optical modulation layer;

a light source for generating a light beam;

an optical system for separating the light beam generated by said light source into a plurality of optical paths so as to guide the light beam to said display panels and for synthesizing light modulated by said display panels into a single optical path; and

a projection device for projecting light synthesized by said optical system.

28. A projection type liquid crystal display comprising:

a plurality of display panels, each of said display panels comprising;

a first substrate having pixel electrodes arranged as a matrix and signal lines for applying signals to the pixel electrodes formed thereon and a light-absorbing member made of resin and formed on the signal lines, a second substrate having a counter electrode, and an optical modulation layer interposed between said first and second substrates, said optical modulation layer being capable of forming an optical image due to a change of an optical scattering state;

a light source for generating a light beam;

an optical system for separating the light beam generated by said light source into a plurality of optical paths and guiding the light beam to said display panels; and

a plurality of projection devices for projecting the light modulated by said plurality of display panels.

29. The display according to claim 28, wherein said optical modulation layer comprises a liquid crystal/resin composite including a liquid component and a resin component, said optical modulation layer has a thickness between 5 and 25 μ

m, the liquid crystal component in the composite is set to be between 50 and 85 wt %, the resin component of the composite comprises a photosetting acrylic resin, and the liquid crystal component of the composite comprises a nematic liquid crystal; and

the at least one dielectric film is made of Al₂ O₃, Y₂ O₃ or SiO and has an optical thickness of about λ

/4, and said counter electrode further comprises a transparent, electrically conducting film that has an optical thickness of about λ

/2 and λ

/4, where λ

denotes a rain wavelength of incident light.