Liquid crystal display device

• US 20070024797A1
• Filed: 10/03/2006
• Published: 02/01/2007
• Est. Priority Date: 12/08/2000
• Status: Active Grant

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Shimizu, Hiromasa, Hamamoto, Tatsuo
• Granted Patent: US 7,456,926 B2
• Time in Patent Office: Days
• US Class Current: 349/155
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence

Abstract

In order to prevent irreversible deformation of column-shaped spacers which retain the gap between a pair of substrates between which the liquid crystal layer of a liquid crystal display device is interposed, spacers which assist in preventing such irreversible deformation are newly provided. According to the invention, two or more kinds of spacers which differ in height from a reference surface are disposed on one of the pair of substrates. In addition, a step pattern with which the spacers are to come into contact is formed in advance on the other of the pair of substrates so that the heights of the spacers can be made different.

Claims

1. A liquid crystal display device comprising:

a first substrate;

a liquid crystal layer;

a second substrate;

a plurality of pixel regions formed above the second substrate, and each having a pixel electrode; and

first spacers and second spacers both formed on a main surface of the first substrate and arranged between said pixel electrode of neighboring pixel regions and in the liquid crystal layer,

wherein when the first spacers are not subjected to an external force and not elastically deformed, each of the second spacers is spaced from a stacked structure formed on the second substrate to accommodate potions of the liquid crystal layer therebetween, and each of the first spacers contacts directly with the stacked structure formed on the second substrate,

wherein first portions of the stacked structure contacting with the first spacers are thicker than second portions of the stacked structure corresponding to the second spacers with the portions of the liquid crystal layer interposed therebetween,

a distance between said first portions of the stacked structure and the first spacers is longer than a distance between said second portions of the stacked structure and the second spacers, and

each of the first spacers and the second spacers has a depression.

2. A liquid crystal display device according to claim 1, wherein each of the second spacers contacts with the uppermost of a corresponding one of said second portions of the stacked structure formed on the second substrate, when the first spacers are subjected to an external force and elastically deformed.

3. A liquid crystal display device according to claim 1, wherein

each of the first spacers contacts with a corresponding one of said first portions of the stacked structure at an overlappingly intersecting position of one of first signal lines and one of second signal lines, and

each of the second spacers contacts with a corresponding one of said second portions of the stacked structure which includes one of the first signal lines but not any one of the second signal lines.

4. A liquid crystal display device according to claim 1, further comprising a black mask and color filters, wherein the black mask and the color filters are covered by a protective film which buries steps formed by the black mask and the color filters, and the first spacers and the second spacers are formed on respective parts of the protective film covering the black mask.

5. A liquid crystal display device, according to claim 1, wherein the second substrate has a plurality of pixels arranged on the main surface thereof, and each of the plurality of pixels has a switching element controlled by one of first signal lines and a pixel electrode receiving a signal from one of second signal lines through the switching element.

6. A liquid crystal display device comprising:

a first substrate including color filters;

a liquid crystal layer;

a second substrate disposed opposite to the first substrate across the liquid crystal layer;

a plurality of first signal lines formed above the second substrate, a plurality of second signal lines intersecting the first signal lines over an insulating film therebetween;

a plurality of pixel regions each formed as being surrounded by respective neighboring first signal lines and second signal lines, and having a pixel electrode;

a base pattern formed between pixel electrodes of neighboring pixel regions;

a plurality of first spacers each formed above a main surface of the first substrate and arranged above a first portion thereof between said pixel electrodes of neighboring pixel regions and overlapping with the base pattern in a plan view; and

a plurality of second spacers each formed above the main surface of the first substrate and arranged above a second portion thereof between said pixel electrodes of neighboring pixel regions and not overlapping with the base pattern in a plan view,

wherein when the first spacers are not subjected to an external force and not elastically deformed, each of the second spacers is spaced from a stacked structure formed on the second substrate to accommodate portions of the liquid crystal layer therebetween, and each of the first spacers formed above the base pattern contacts directly with the stacked structure formed on the second substrate,

said first portion includes the base pattern, said second portion does not include the base pattern, and said first portion is disposed apart from said second portion across the pixel region, and

each of the first spacers and the second spacers has a depression.

7. A liquid crystal display device, according to claim 6, wherein each of the second spacers contacts with the uppermost of said second portion of the stacked structure formed on the second substrate, when the first spacers are subjected to an external force and elastically deformed.

8. A liquid crystal display device, according to claim 6, wherein the base pattern is covered by a protective film formed between the base pattern and the first spacers.