Liquid crystal display and method of manufacturing the same

• US 8,044,907 B2
• Filed: 12/06/2010
• Issued: 10/25/2011
• Est. Priority Date: 03/18/2003
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tashiro, Kunihiro, Tsuda, Hideaki, Sasabayashi, Takashi, Ueda, Kazuya, Takeda, Arihiro, Tasaka, Yasutoshi, Inoue, Hiroyasu, Yoshida, Hidefumi, Koike, Yoshio, Kamada, Tsuyoshi, Nakamura, Kimiaki
• Primary Examiner(s): Wang; Quan-Zhen
• Assistant Examiner(s): Nguyen; Jennifer T
• Application Number:
  US12/961,009
• Publication Number:
  US 20110075060A1
• Time in Patent Office: 323 Days
• Field of Search: 345 87-100, 345/204, 345211-213, 345/690, 349/42, 349/43, 349/144
• US Class Current: 345/92
• CPC Class Codes: G02F 1/133371 Cells with varying thickness of the liquid crystal layer
• 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 1/133757 with different alignment orientations
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: G02F 1/134345 Subdivided pixels, e.g. for grey scale or redundancy
• CPC Class Codes: G02F 1/1393 the birefringence of the liquid crystal being electrically controlled, e.g. ECB-, DAP-, HAN-, PI-LC cells G02F1/1396, G02F1/141 take precedence

Abstract

A liquid crystal display including two substrates, gate bus lines, liquid crystal molecules, and a polymer that determines directions in which the liquid crystal molecules tilt. A plurality of divisional areas are arranged on one of the substrates. The pixels are aligned in a column between drain bus lines. A pixel electrode is formed at each of the divisional areas. A first thin film transistor drives a first divisional area, and a second thin film transistor drives a second divisional area of the same column. The first and second thin film transistors are electrically connected to the same gate bus line. Either the pixel electrodes formed at each of the divisional areas are electrically insulated from each other, or they are connected to each other through a high resistance. A first threshold voltage within the first divisional area is different from a second threshold voltage of the second divisional area.

Claims

1. A liquid crystal display comprising:

a pair of substrates provided opposite to each other;

a plurality of divisional areas which are a plurality of divisions of each pixel arranged on one of the pair of substrates, wherein a plurality of the pixels are aligned in a column between adjacent drain bus lines, and further wherein the liquid crystal display includes a plurality of said columns;

a plurality of gate bus lines provided on said one of the substrates;

a pixel electrode formed at each of the divisional areas;

a first thin film transistor driving a first of the divisional areas and a second thin film transistor driving a second of the divisional areas, wherein said first and second thin film transistors are both electrically connected to the same gate bus line, and further wherein both said first divisional area and said second divisional area are located in the same one of said columns;

liquid crystal molecules sealed between the pair of substrates; and

a polymer, formed between said substrates, wherein said polymer determines directions in which the liquid crystal molecules tilt,

wherein the pixel electrodes formed at each of the divisional areas are electrically insulated from each other or the pixel electrodes formed at each of the divisional areas are connected to each other through a high resistance, and

wherein a first threshold voltage of liquid crystal molecules within said first divisional area is different from a second threshold voltage of liquid crystal molecules within said second divisional area.

2. The liquid crystal display according to claim 1, wherein a first pre-tilt angle is the only pre-tilt angle defined within said first divisional area and a second pre-tilt angle is the only pre-tilt angle defined within said second divisional area.

3. The liquid crystal display according to claim 1, wherein a first pre-tilt angle is obtained by radiating UV light while applying a first voltage to the liquid crystal molecules of the first divisional area and a second pre-tilt angle is obtained by radiating UV light while applying a second voltage to the liquid crystal molecules of the second divisional area, and further wherein the first voltage is different from the second voltage.

4. The liquid crystal display according to claim 1, further comprising:

a first storage capacitor bus line forming a first storage capacitor (Cs1) with the pixel electrode of said first divisional area; and

a second storage capacitor bus line forming a second storage capacitor (Cs2) with the pixel electrode of said second divisional area,

wherein the following is satisfied;

Cs1/(Cs1+Clc1)≠

Cs2/(Cs2+Clc2), wherein Clc1 is the liquid crystal capacitance of the first divisional area and Clc2 is the liquid crystal capacitance of the second divisional area.

5. The liquid crystal display according to claim 1, wherein each pixel is defined by an area bordered by a pair of adjacent ones of said gate bus lines and a pair of adjacent ones of said drain bus lines.

6. The liquid crystal display according to claim 1, wherein a threshold voltage difference between the first and the second divisional areas is 0.3 V or more.

7. The liquid crystal display according to claim 1, wherein a threshold voltage difference between the first and the second divisional areas is 0.5 V or more.

8. The liquid crystal display according to claim 1, wherein a threshold voltage difference between the first and the second divisional areas is 0.7 V or more.