Liquid crystal display element with comb electrodes having reflective projections and producing method thereof

• US 6,583,840 B1
• Filed: 05/26/2000
• Issued: 06/24/2003
• Est. Priority Date: 05/26/1999
• Status: Expired due to Fees

• Current Assignee: Godo Kaisha IP Bridge 1 (IP Bridge, Inc.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yamakita, Hiroyuki, Inoue, Kazuo, Kimura, Masanori, Kumagawa, Katsuhiko, Shiota, Akinori
• Primary Examiner(s): Kim, Robert H.
• Assistant Examiner(s): Rude, Timothy L.
• Application Number:
  US09/580,171
• Time in Patent Office: 1,124 Days
• Field of Search: 349/139, 349/152, 349/141
• US Class Current: 349/141
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

A liquid crystal display element comprising a liquid crystal panel which comprises a pair of substrates and liquid crystal material sealed between the pair of substrates and in which pixel electrode parts of pixel electrodes and common electrode parts of common electrodes are alternately formed on a plane of one of the pair of substrates to change alignment of liquid crystal molecules by generating a horizontal (X) electric field in the plane, wherein at least one of the pixel electrode parts and the common electrode parts has a tapered section with respect to a horizontal (X) electric field direction and are transparent. The horizontal (X) electric field causes improved display characteristics, aperture ratio and response speed.

Claims

1. A liquid crystal display element comprising liquid crystal material sandwiched between at least a pair of substrates, and pixel electrodes having a plurality of pixel electrode parts and common electrodes having a plurality of common electrode parts formed on at least one of said substrates, said pixel electrode parts and common electrode parts for changing alignment of liquid crystal molecules by applying a voltage across said pixel electrodes and said common electrodes,

wherein at least one electrode part of said pixel electrodes and/or said common electrodes comprises a plurality of separate projections and an electrode layer formed thereon and comprising light reflecting material, said projections being formed into a shape that diffusely reflects incident rays of light.

2. A liquid crystal display element according to claim 1, wherein at least one of said projections has a form of two or more protuberances of different height being combined together.

3. A liquid crystal display element according to claim 1, wherein at least two of said projections are each different in cone angle.

4. A liquid crystal display element comprising a liquid crystal panel which comprises first and second substrates and liquid crystal material sealed between said first and second substrates, and a plane of one of said first and second substrates for generating a horizontal (X) electric field for changing alignment of said liquid crystals, wherein

said plane additionally comprises a plurality of striped projections and depressions thereon,

pixel electrode parts of pixel electrodes and common electrode parts of common electrodes are on alternate side faces of striped projection portions of said striped projections and depressions, and

a distance between two adjoining electrode parts at a top of each striped projection part is not more than 6 μ

m and at least one of said pixel electrode parts and said common electrode parts is transparent.

5. A liquid crystal display element comprising a liquid crystal panel which comprises a pair of substrates and liquid crystal material sealed between said pair of substrates and in which a plane of one of said pair of substrates has alternating pixel electrode parts of pixel electrodes and common electrode parts of common electrodes for changing alignment of liquid crystal molecules by generating a horizontal (X) electric field in said plane, wherein

at least one of said pixel electrode parts and said common electrode parts has a tapered section with respect to a horizontal (X) electric field direction and is transparent, and

a distance between said alternating pixel electrode parts and common electrode parts is limited to not more than 6 μ

m.

6. A liquid crystal display element comprising a liquid crystal panel which comprises a pair of substrates and liquid crystal material sealed in between said pair of substrates and in which pixel electrode parts of pixel electrodes and common electrode parts of common electrodes are located alternately on a plane of one of said pair of substrates for changing alignment of liquid crystal molecules by generating a horizontal (X) electric field in said plane, wherein

at least one of said pixel electrode parts and said common electrode parts is located on a transparent insulation layer having a tapered section with respect to a horizontal (X) electric field direction and is made of a transparent conductive film;

and

wherein a distance between said alternating pixel electrode parts and common electrode parts is limited to not more than 6 μ

m.

7. A liquid crystal display element comprising liquid crystal material sandwiched between at least a pair of substrates, and pixel electrodes comprising a plurality of pixel electrode parts and common electrodes comprising a plurality of common electrode parts, said pixel electrodes and said common electrodes located on at least one of said substrates and for changing alignment of liquid crystal molecules by a voltage applied across said pixel electrodes and said common electrodes, wherein

at least one electrode part of said pixel electrodes and/or said common electrodes comprises two or more separate projections, and

sizes of said projections are different depending upon the distance between each such projection and a center of a pixel.

8. A liquid crystal display element according to claim 7, wherein

on one of said common electrodes and said pixel electrodes said projections increase in size depending upon their distance from a center of said pixel,

and on the other of said common electrodes and said pixel electrodes said projections decrease in size depending upon their distance from a center of said pixel.

9. A liquid crystal display element according to claim 7, wherein said two or more separate projections are of differing heights.