Liquid crystal display device

• US 8,054,422 B2
• Filed: 09/25/2007
• Issued: 11/08/2011
• Est. Priority Date: 03/27/2006
• Status: Active Grant

• Current Assignee: NLT Technologies, Ltd.
• Original Assignee: NEC LCD Technologies Limited (NEC Corporation)
• Inventors: Sumiyoshi, Ken, Uehara, Shinichi, Matsushima, Jin
• Primary Examiner(s): NGUYEN, THANH NHAN P
• Application Number:
  US11/860,875
• Publication Number:
  US 20080018840A1
• Time in Patent Office: 1,505 Days
• Field of Search: 349/114, 349/141
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133541 Circular polarisers
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133634 the refractive index Nz perpendicular to the element surface being different from in-plane refractive indices Nx and Ny, e.g. biaxial or with normal optical axis
• CPC Class Codes: G02F 1/133636 with twisted orientation, e.g. comprising helically oriented LC-molecules or a plurality of twisted birefringent sublayers
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 2413/13 Positive birefingence
• CPC Class Codes: G02F 2413/14 Negative birefingence

Abstract

To improve a patterning accuracy of pixel electrodes and common electrodes. The liquid crystal display device includes a reflective display area and a transmissive display area within a pixel that is configured with a pair of opposing substrates and a liquid crystal layer provided between the substrates. The reflective display area achieves display by reflection of light, and the transmissive display area achieves display by transmission of light. A laminated body including a reflective plate, an insulating layer, and a metal electrode for rotating liquid crystal molecules of the liquid crystal layer within a surface thereof is provided within the reflective display area.

Claims

1. A liquid crystal display device comprising:

a pair of opposing substrates;

a liquid crystal layer provided between the pair of opposing substrates; and

a plurality of pixels provided in one of the pair of substrates, each one of the plurality of pixels having a reflective display area and a transmissive display area therein, the reflective display area achieving display by reflection of light, and the transmissive display area achieving display by transmission of light,

wherein a laminated body including a reflective plate, an insulating layer, and an opaque metal electrode for rotating liquid crystal molecules of the liquid crystal layer within a surface thereof is provided within the reflective display area,

the opaque metal electrode within the reflective display area is a common electrode or a pixel electrode,

the reflective display area has the reflective plate provided between a substrate on which the reflective plate is formed and the metal electrode,

opaque metal electrodes for rotating the liquid crystal molecules of the liquid crystal layer within a surface thereof are provided within the transmissive display area,

the opaque metal electrodes within the transmissive display area include a common electrode and a pixel electrode, and

the pixel electrode and the common electrode in the transmissive display area are respectively formed in a comb-like shape, and the electrodes are disposed alternately in a same layer.

2. The liquid crystal display device as claimed in claim 1, wherein the metal electrode is formed with a same layer as one of metal layers which configure a gate electrode, a drain electrode, or a source electrode of a thin film transistor that is formed in the transmissive display area within the pixel.

3. The liquid crystal display device as claimed in claim 1, wherein a thickness of the liquid crystal layer varies in the reflective display area and in the transmissive display area.

4. The liquid crystal display device as claimed in claim 1, wherein a thickness of the liquid crystal layer is identical in the reflective display area and in the transmissive display area.

5. The liquid crystal display device as claimed in claim 1, wherein intensity of an electric field for driving the liquid crystal layer varies in the reflective display area and in the transmissive display area.

6. The liquid crystal display device as claimed in claim 1, wherein intensity of an electric field for driving the liquid crystal layer is weaker in the reflective display area than in the transmissive display area.

7. The liquid crystal display device as claimed in claim 1, wherein a pitch between electrodes for generating an electric field in the reflective display area is wider than a pitch between electrodes for generating an electric field in the transmissive display area.

8. The liquid crystal display device as claimed in claim 1, wherein the reflective plate has a rough surface that diffusely reflects incident light.

9. A liquid crystal display device comprising:

a pair of opposing substrates;

a liquid crystal layer provided between the pair of opposing substrates; and

a plurality of pixels provided in one of the pair of substrates, each one of the plurality of pixels having a reflective display area and a transmissive display area therein, the reflective display area achieving display by reflection of light, and the transmissive display area achieving display by transmission of light,

wherein a laminated body including a reflective plate, an insulating layer, and an opaque metal electrode for rotating liquid crystal molecules of the liquid crystal layer within a surface thereof is provided within the reflective display area,

the reflective plate within the reflective display area is a common electrode or a pixel electrode,

the reflective display area has the reflective plate provided between a substrate on which the reflective plate is formed and the metal electrode,

opaque metal electrodes for rotating the liquid crystal molecules of the liquid crystal layer within a surface thereof are provided within the transmissive display area,

the opaque metal electrodes within the transmissive display area include a common electrode and a pixel electrode, and

the pixel electrode and the common electrode in the transmissive display area are formed in a comb-like shape alternately in a same layer.

10. A liquid crystal display device comprising:

a pair of opposing substrates;

a liquid crystal layer provided between the pair of opposing substrates; and

a plurality of pixels provided in one of the pair of substrates, each one of the plurality of pixels having a reflective display area and a transmissive display area therein, the reflective display area achieving display by reflection of light, and the transmissive display area achieving display by transmission of light,

wherein a laminated body including a reflective plate, an insulating layer, and an opaque metal electrode for rotating liquid crystal molecules of the liquid crystal layer within a surface thereof is provided within the reflective display area,

the opaque metal electrode within the reflective display area includes a common electrode and a pixel electrode,

the reflective display area has the reflective plate provided between a substrate on which the reflective plate is formed and the metal electrode,

opaque metal electrodes for rotating the liquid crystal molecules of the liquid crystal layer within a surface thereof are provided in the transmissive display area,

the opaque metal electrodes within the transmissive display area include a common electrode and a pixel electrode, and

the pixel electrode and the common electrode in the transmissive display area are formed in a comb-like shape, and the electrodes are disposed alternately in a same layer.

11. A liquid crystal display device comprising:

a pair of opposing substrates;

a liquid crystal layer provided between the pair of opposing substrates; and

a plurality of pixels provided in one of the pair of substrates, each one of the plurality of pixels having a reflective display area and a transmissive display area therein, the reflective display area achieving display by reflection of light, and the transmissive display area achieving display by transmission of light,

wherein a laminated body including a reflective plate, an insulating layer, and an opaque metal electrode for rotating liquid crystal molecules of the liquid crystal layer within a surface thereof is provided within the reflective display area,

the opaque metal electrode within the reflective display area includes a common electrode and a pixel electrode,

the reflective plate is a rough-surface reflective plate,

the reflective display area has the reflective plate provided between a substrate on which the reflective plate is formed and the metal electrode,

opaque metal electrodes for rotating the liquid crystal molecules of the liquid crystal layer within a surface thereof are provided in the transmissive display area,

the opaque metal electrodes within the transmissive display area include a common electrode and a pixel electrode, and

the pixel electrode and the common electrode in the transmissive display area are formed in a comb-like shape, and the electrodes are disposed alternately in a same layer.