Liquid crystal display device and liquid crystal display apparatus

• US 5,748,275 A
• Filed: 12/01/1995
• Issued: 05/05/1998
• Est. Priority Date: 12/01/1994
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hisatake, Yuzo, Watanabe, Ryoichi, Hatoh, Hitoshi, Sato, Makiko
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): DUDEK, JAMES A
• Application Number:
  US08/566,038
• Time in Patent Office: 886 Days
• Field of Search: 349/143, 349/144, 349/180, 349/136
• US Class Current: 349/144
• CPC Class Codes: G02F 1/134336 Matrix
• CPC Class Codes: G02F 2201/124 interdigital

Abstract

A liquid crystal display device including a first substrate supporting a plurality of pixels, each having an electrode, a second substrate having an electrode and arranged such that the electrode of the first substrate opposes the electrode of the second substrate, a nematic liquid crystal composition layer held between the first and second substrates, and aligning films for aligning liquid crystal molecules of the nematic liquid crystal composition in one direction on surfaces of the first and second substrates, wherein the electrode of the first substrate in each pixel includes a plurality of conductive layers each having a width of 50 μm or less, and a distance between the conductive layers being 50 μm or less, and at least two of the plurality of conductive layers being electrically connected in at least part of an area in the pixel, the electrode of the second substrate consists of a continuous conductive film, and a distance RS between the conductive layers and a distance D between the electrode of the first substrate and the electrode of the second substrate satisfy the following inequality.

tan (π/9)≦RS/2D≦tan (7π/18)

Claims

1. A liquid crystal display device comprising:

a first substrate supporting a plurality of pixels, each having an electrode;

a second substrate having an electrode and arranged such that said electrode of said first substrate opposes said electrode of said second substrate;

a nematic liquid crystal composition layer held between said first and second substrates; and

means for aligning liquid crystal molecules of the nematic liquid crystal composition in one direction on surfaces of said first and second substrates,

wherein said electrode of the first substrate in each pixel includes a plurality of stripe-shaped conductive layers each having a width not more than 50 μ

m, a distance between said conductive layers being not more than 50 μ

m, and at least two of said conductive layers being electrically connected in at least part of an area in said pixel,

said electrode of the second substrate consists of a continuous conductive film, and

a distance RS between said conductive layers and a distance D between said electrode of said first substrate and said electrode of second substrate satisfy the following inequality;

space="preserve" listing-type="equation">tan (π

/9)≦

RS/2D≦

tan (7π

/18).

2.

2. A device according to claim 1, wherein the distance RS and the distance D satisfy the following inequality:

space="preserve" listing-type="equation">tan (π

/4)≦

RS/2D≦

tan (π

/18).

3. A device according to claim 1, wherein a width EE of said conductive layer and the distance D satisfy the following inequality:

space="preserve" listing-type="equation">D/2≦

EE≦

3D.

4. A device according to claim 1, wherein, when the liquid crystal composition has a negative dielectric anisotropy, a width EE of said conductive layer and the distance RS satisfy an inequality RS/3≦

EE≦

1.1×

RS, and when the liquid crystal composition has a positive dielectric anisotropy, the width EE of said conductive layer and the distance RS satisfy an inequality 0≦

EE≦

RS.

5. A device according to claim 1, wherein a width EE of said conductive layer and the distance RS satisfy the following inequality:

space="preserve" listing-type="equation">2.5 μ

m≦

EE+RS≦

36 μ

m.

6. A device according to claim 1, wherein a liquid crystal molecular alignment of the liquid crystal composition is one of a homogeneous alignment in which a longitudinal liquid crystal molecular axis is set parallel to a direction of a stripe of said stripe-shaped conductive layers and a vertical alignment in which the longitudinal liquid crystal molecular axis is vertically set between said first and second substrates.

7. A device according to claim 6, wherein incident light consists of a visible range, and a product of an index anisotropy Δ

n of the liquid crystal composition and a thickness d of a liquid crystal layer satisfy the following relation;

space="preserve" listing-type="equation">350 nm≦

Δ

nd≦

1050 nm.

8. A device according to claim 6, wherein incident light is monochromatic light having a band width not more than 100 nm, and a product of an index anisotropy Δ

n of the liquid crystal composition and a thickness d of a liquid crystal layer satisfy the following relation;

space="preserve" listing-type="equation">(λ

-50)/2 nm≦

Δ

nd≦

2(λ

+50)nm

where λ

is the center wavelength of the monochromatic light.

9. A liquid crystal display apparatus comprising:

said liquid crystal display device according to claim 1;

means for causing light to have an angle less than 10 deg with respect to a normal direction of an element plane and to be incident on said liquid crystal display device;

means for controlling the incident light by said liquid crystal display device; and

an optical system for projecting light in a same direction of propagation as directions of the controlled light.

10. An apparatus according to claim 9, wherein a plurality of liquid crystal devices are used as said liquid crystal display device, and said means for causing the light to have an angle less than 10 deg with respect to the normal direction of said element plane and to be incident is means for causing light beams obtained as spectral components excluding at least one of red, blue, and green wavelengths to be incident on said plurality of liquid crystal display devices, respectively.

11. An apparatus according to claim 9, further comprising a layer having the same optical function as that of a convex lens and arranged on a substrate on an outer rear surface on the incident light side of said liquid crystal display device in correspondence with each pixel of said liquid crystal display device.

12. An apparatus according to claim 11, further comprising a layer having the same optical function as that of a convex lens or a concave lens arranged between an electrode of said substrate on the incident light side of said liquid crystal display device and said layer having the same optical function as that of a convex lens, and wherein a light beam transmitted through said layer having the same optical function as that of a convex lens and said layer having the same optical function as that of a convex lens or a concave lens has an angle with respect to the normal direction of a plane of said liquid crystal display device plane, which angle is 0.9 to 1.1 times that of the incident light with respect to the normal direction of said plane of said liquid crystal display device.

13. A projection-type display apparatus comprising:

a display panel consisting of said liquid crystal display device according to claim 1 and having an optical modulation layer for controlling a light transmittance;

a light source optical system for guiding a source light beam from a light source to said display panel; and

a projection optical system for projecting a modulated light beam optically modulated by said display panel onto a screen.

14. A liquid crystal display device comprising:

a first substrate supporting a plurality of pixels, each having an electrode;

a second substrate having an electrode and arranged such that said electrode of said first substrate opposes said electrode of said second substrate;

a nematic liquid crystal composition layer held between said first and second substrates; and

means for aligning liquid crystal molecules of the nematic liquid crystal composition in one direction on surfaces of said first and second substrates,

wherein said electrode of the first substrate in each pixel includes a plurality of first stripe-shaped conductive layers each having a width not more than 50 μ

m, a distance between said first conductive layers being not more than 50 μ

m, and at least two of said conductive layers are electrically connected in at least part of an area in said pixel,

said electrode of said second substrate in each pixel includes a plurality of second conductive layers each having a width not more than 50 μ

m, a distance between said conductive layers being not more than 50 μ

m, said second conductive layers extending in the same direction as that of said first conductive layers, and at least two of said plurality of second conductive portions being electrically connected in at least part of an area in said pixel,

said first conductive layers and said second conductive layers are staggered from each other in a direction of width without opposing each other,

said liquid crystal composition layer includes a layer portion FE sandwiched between each first conductive layer and part of a corresponding portion between said second conductive layers, a layer portion SS adjacent to said layer portion FE and sandwiched between part of a portion between said first conductive layers and part of a corresponding portion between said second conductive layers, and a layer portion RE adjacent to said layer portion SS and sandwiched between part of a portion between said first conductive layers and a corresponding one of said second conductive layers are periodically repeated in an order of FE, SS, RE, FE, SS, RE, . . . , and

the width SS of said layer portion SS and a distance D between said electrode of said first substrate and said electrode of second substrate satisfy the following inequality;

space="preserve" listing-type="equation">tan (π

/9)≦

SS/D-tan (7π

/18).

15. A device according to claim 14, wherein the width RE of said layer portion RE, the width FE of said layer portion FE, and the distance D satisfy the following inequalities:

space="preserve" listing-type="equation">D/2≦

RE≦

3D,

and

space="preserve" listing-type="equation">D/2≦

FE≦

3D.

16. A device according to claim 14, wherein the width RE of said layer portion RE, the width SS of said layer portion SS, and the width FE of said layer portion FE satisfy the following inequalities:

space="preserve" listing-type="equation">0.9×

SS≦

RE≦

1.1×

SS,

and

space="preserve" listing-type="equation">0.9×

SS≦

FE≦

1.1×

SS.

17. A devices according to claims 14, wherein the width RE of said layer portion RE, the width SS of said layer portion SS, and the width FE of said layer portion FE satisfy the following inequalities:

space="preserve" listing-type="equation">2.5 μ

m≦

RE+SS≦

36 μ

m,

and

space="preserve" listing-type="equation">2.5 μ

m≦

FE+SS≦

36 μ

m.

18. A device according to claim 14, wherein a liquid crystal molecular alignment of the liquid crystal composition is one of a homogeneous alignment in which a longitudinal liquid crystal molecular axis is set parallel to a direction of a stripe of said conductive layers and a vertical alignment in which the longitudinal liquid crystal molecular axis is vertically set between said first and second substrates.

19. A device according to claim 14, wherein incident light consists of a visible range, and a product of an index anisotropy Δ

n of the liquid crystal composition and a thickness d of a liquid crystal layer satisfy the following relation;

space="preserve" listing-type="equation">350 nm≦

-Δ

nd≦

1050 nm.

20. A device according to claim 18, wherein incident light is monochromatic light having a band width not more than 100 nm, and a product of an index anisotropy Δ

n of the liquid crystal composition and a thickness d of a liquid crystal layer satisfy the following relation;

space="preserve" listing-type="equation">(λ

-50)/2 nm-Δ

nd≦

2(λ

+50)nm

where λ

is the center wavelength of the monochromatic light.

21. A liquid crystal display apparatus comprising:

said liquid crystal display device according to claim 14;

means for causing light to have an angle less than 10 deg with respect to a normal direction of an element plane and to be incident on said liquid crystal display device;

means for controlling the incident light by said liquid crystal display device; and

an optical system for projecting light in a same direction of propagation as directions of the controlled light.

22. An apparatus according to claim 21, wherein a plurality of liquid crystal devices are used as said liquid crystal display device, and said means for causing the light to have an angle less than 10 deg with respect to the normal direction of said device plane and to be incident is means for causing light beams obtained as spectral components excluding at least one of red, blue, and green wavelengths to be incident on said plurality of liquid crystal display devices, respectively.

23. An apparatus according to claim 21, further comprising a layer having the same optical function as that of a convex lens and arranged on a substrate on an outer rear surface on the incident light side of said liquid crystal display device in correspondence with each pixel of said liquid crystal display device.

24. An apparatus according to claim 23, further comprising a layer having the same optical function as that of a convex lens or a concave lens arranged between an electrode of said substrate on the incident light side of said liquid crystal display device and said layer having the same optical function as that of a convex lens, and wherein a light beam transmitted through said layer having the same optical function as that of a convex lens and said layer having the same optical function as that of a convex lens or a concave lens has an angle with respect to the normal direction of a plane of said liquid crystal display device plane, which angle is 0.9 to 1.1 times that of the incident light with respect to the normal direction of said plane of said liquid crystal display device.