In-plane field type liquid crystal display device comprising a structure which is prevented from charging electricity

• US 6,034,757 A
• Filed: 02/08/1999
• Issued: 03/07/2000
• Est. Priority Date: 10/12/1995
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Yanagawa, Kazuhiko, Ohta, Masuyuki, Ashizawa, Keiichiro, Matsuyama, Shigeru, Mishima, Yasuyuki, Konishi, Nobutake, Ogawa, Kazuhiro, Yanai, Masahiro, Kinugawa, Kiyoshige
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US09/245,898
• Time in Patent Office: 393 Days
• Field of Search: 349/141, 349/96, 349/59, 349/110
• US Class Current: 349/141
• CPC Class Codes: G02F 1/133331 Cover glasses
• CPC Class Codes: G02F 1/133334 Electromagnetic shields
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• 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 1/136204 Arrangements to prevent high voltage or static electricity failures

Abstract

Even when a high potential such as of static electricity is applied from the outside of the liquid crystal display panel, the display image is prevented from becoming abnormal. When a black matrix of a resin composition having a large resistivity is used, the positions of the polarizer plates, black matrix, sealing portion and open region of the housing are defined to prevent the light from leaking through the periphery of the effective pixel region. The leakage of backlight that cannot be prevented by the black matrix only is prevented by the polarizer plates and the housing, a transparent electrically conductive film having a sheet resistivity of not larger than 2×10⁴ Ω/□ is formed over, under, or inside the polarizer plate, and the electrically conductive film is electrically connected to the electrically conductive housing.

Claims

1. A liquid crystal display comprising:

a pair of substrates having opposed surfaces with a space therebetween;

a liquid crystal layer facing toward the opposed surfaces of the pair of substrates and sealed in the space;

at least one first electrode disposed in the space and forming a part of a pixel;

a plurality of second electrodes disposed in the space with respect to the at least one first electrode so as to generate an electric field having a major component substantially in parallel with one of the pair of the substrates in a region of the pixel; and

an electrically conductive layer disposed on a surface of at least one of the pair of the substrates which is opposite to the opposed surfaces thereof and faces away from the liquid crystal layer which is sealed in the space.

2. The liquid crystal display device according to claim 1, wherein a plurality of first electrodes form the pixel, and a number of the plurality of second electrodes is greater than a number of the plurality of first electrodes.

3. The liquid crystal display device according to claim 1, wherein the electrically conductive layer has a sheet resistivity no greater than 2×

10¹⁴ Ω

/□

.

4. The liquid crystal display device according to claim 1, wherein the electrically conductive layer has a sheet resistivity no greater than 1×

10⁸ Ω

/□

.

5. The liquid crystal display device according to claim 1, wherein the electrically conductive layer has a light-transmission factor of not smaller than 34%.

6. The liquid crystal display device according to claim 1, wherein one of the pair of substrates is transparent and the electrically conductive layer is disposed on the surface of the one substrate which is transparent.