Liquid crystal display device with stacked insulating film of different layers

• US 6,710,835 B2
• Filed: 01/04/2002
• Issued: 03/23/2004
• Est. Priority Date: 01/29/2001
• Status: Expired due to Term

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakayoshi, Yoshiaki, Ishii, Masahiro, Kurahashi, Nagatoshi
• Primary Examiner(s): CHOWDHURY, TARIFUR RASHID
• Application Number:
  US10/035,146
• Publication Number:
  US 20020101555A1
• Time in Patent Office: 809 Days
• Field of Search: 349/42, 349/43, 349/138, 349/141
• US Class Current: 349/141
• 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 2201/121 common or background

Abstract

A liquid crystal display device that is capable of restraining image retention includes, a counter electrode formed in a layer overlying the pixel electrode with a stacked insulating film interposed therebetween. The counter electrode is made of a plurality of stripe-shaped counter electrodes which are disposed so as to extend in one direction and to be juxtaposed in a direction transverse to the one direction, and the pixel electrode is made of a transparent plane-shaped electrode, which is formed in a large part of the pixel area.

Claims

1. A liquid crystal display device comprising, in each pixel area on a liquid-crystal-side surface of one of substrates disposed in opposition to each other with a liquid crystal interposed therebetween:

a thin film transistor to be driven by supply of a scanning signal from a gate signal line;

a pixel electrode to be supplied with a video signal from a drain signal line via the thin film transistor; and

a counter electrode which causes an electric field to be generated between the counter electrode and the pixel electrode,

the counter electrode being formed in a layer overlying the pixel electrode with a stacked insulating film interposed between the counter electrode and the pixel electrode,

the stacked insulating film being made of a stacked structure in which an insulating film including a part of a gate insulating film of the thin film transistor, an inorganic material layer and an organic material layer are stacked in that order,

the counter electrode being made of a plurality of stripe-shaped counter electrodes which are disposed to be extended in one direction and to be juxtaposed in a direction transverse to the one direction, and

the pixel electrode being made of a transparent plane-shaped electrode which is formed in a large part of the pixel area.

2. A liquid crystal display device according to claim 1, wherein a counter voltage signal line is formed in the same layer as the pixel electrode and is connected to the counter electrode through a through-hole formed in the stacked insulating film.

3. A liquid crystal display device according to claim 1, wherein the pixel electrode is connected to a source electrode of the thin film transistor through a through-hole formed in the stacked insulating film formed in the layer overlying the pixel electrode and a through-hole formed in a protective film formed in a layer overlying the source electrode of the thin film transistor.

4. A liquid crystal display device according to claim 1, wherein the plurality of counter electrodes are formed to extend approximately in parallel with the drain signal line and include a counter electrode which is superposed on the drain signal line and which has a central axis approximately coincident with a central axis of the drain signal line and is wider than the drain signal line.

5. A liquid crystal display device comprising, in each pixel area on a liquid-crystal-side surface of one of substrates disposed in opposition to each other with a liquid crystal interposed therebetween:

a thin film transistor to be driven by supply of a scanning signal from a gate signal line;

a pixel electrode to be supplied with a video signal from a drain signal line via the thin film transistor; and

a counter electrode which causes an electric held to be generated between the counter electrode and the pixel electrode,

the counter electrode being formed in a layer overlying pixel electrode with an interposed film interposed between at least a portion of counter electrode and at least a portion of the pixel electrode,

the interposed film including at least an organic material layer,

the counter electrode being made of a plurality of stripe-shaped counter electrodes which are disposed to be extended in one direction and to be juxtaposed in a direction transverse to the one direction, and

the pixel electrode being made of a transparent plane-shaped electrode which is formed in a large Dart of the pixel area;

wherein the pixel electrode is formed on an insulating film including a part of a gate insulating film of the thin film transistor, and a counter voltage signal line is formed in a layer underlying the insulating film, the counter voltage signal line being connected to the counter voltage through a through-hole extended through the interposed film and the insulating film.

6. A liquid crystal display device comprising, in each pixel area on a liquid-crystal-side surface of one of substrates disposed in opposition to each other with a liquid crystal interposed therebetween:

a thin film transistor to be driven by supply of a scanning signal from a gate signal line;

a pixel electrode to be supplied with a video signal from a drain signal line via the thin film transistor; and

a counter electrode which causes an electric field to be generated between the counter electrode and the pixel electrode,

the counter electrode being formed in a layer overlying pixel electrode with an interposed film interposed between at least a portion of counter electrode and at least a portion of the pixel electrode,

the interposed film including at least an organic material layer,

the counter electrode being made of a plurality of stripe-shaped counter electrodes which are disposed to be extended in one direction and to be juxtaposed in a direction transverse to the one direction, and

the pixel electrode being made of a transparent plane-shaped electrode which is formed in a large part of the pixel area;

wherein the plurality of counter electrodes are formed to extend approximately in parallel with the drain signal line and include a counter electrode which is superposed on the drain signal line and which has a central axis approximately coincident with a central axis of the drain signal line and is wider than the drain signal line.

7. A liquid crystal display device comprising, in each pixel area on a liquid-crystal-side surface of one of substrates disposed in opposition to each other with a liquid crystal interposed therebetween:

a thin film transistor to be driven by supply of a scanning signal from a gate signal line;

a pixel electrode to be supplied with a video signal from a drain signal line via the thin film transistor; and

a counter electrode which causes an electric field to be generated between the counter electrode and the pixel electrode,

the pixel electrode being made of a transparent plane-shaped electrode which is formed in a large part of the pixel area on a first protective film made of an inorganic material layer formed to cover the thin film transistor and is connected to a source electrode of the thin film transistor through a contact hole formed in the first protective film,

the counter electrode being made of a plurality of electrodes which are formed on a second protective film made of an organic material layer formed to cover the pixel electrode on the first protective film and which are disposed to be extended in one direction and to be juxtaposed in a direction transverse to the one direction.

8. A liquid crystal display device according to claim 7, wherein the counter electrode is made of a transparent conductive material.

9. A liquid crystal display device according to claim 7, where the plurality of electrodes include a counter electrode which has approximately the same center line as the drain signal line and is superposed thereon, the counter electrode being formed to be greater in width than the drain signal line.

10. A liquid crystal display device comprising, in each pixel area on a liquid-crystal-side surface of one of substrates disposed in opposition to each other with a liquid crystal interposed therebetween:

a thin film transistor to be driven by supply of a scanning signal from a gate signal line;

a pixel electrode to be supplied with a video signal from a drain signal line via the thin film transistor; and

a counter electrode which causes an electric field to be generated between the counter electrode and the pixel electrode,

the counter electrode being formed in a layer overlying pixel electrode with an interposed film interposed between at least a portion of counter electrode and at least a portion of the Pixel electrode,

the interposed film including at least an organic material layer,

the counter electrode being made of a plurality of stride-shaped counter electrodes which are disposed to be extended in one direction and to be Juxtaposed in a direction transverse to the one direction, and

the pixel electrode being made of a transparent plane-shaped electrode which is formed in a large Dart of the pixel area,

wherein the interposed film is at least one of a protective film and an insulating film; and

wherein the interposed film include a stacked structure in which an inorganic material layer and the organic material layer are stacked in that order.

11. A liquid crystal display device according to claim 10, wherein the interposed film is a protective film.

12. A liquid crystal display device according to claim 10, wherein the interposed film made of the stacked structure further includes an insulating film including a part of a gate insulating film of the thin film transistor, the inorganic material layer and the organic material layer stacked in that order.

13. A liquid crystal display device comprising, in each pixel area on a liquid-crystal-side surface of one of substrates disposed in opposition to each other with a liquid crystal interposed therebetween:

a thin film transistor to be driven by supply of a scanning signal from a gate signal line;

a pixel electrode to be supplied with a video signal from a drain signal line via the thin film transistor; and

a counter electrode which causes an electric field to be generated between the counter electrode and the pixel electrode,

the counter electrode being formed in a layer overlying pixel electrode with an interposed film interposed between at least a portion of counter electrode and at least a portion of the pixel electrode,

the interposed film including at least an organic material layer,

the counter electrode being made of a plurality of stripe-shaped counter electrodes which are disposed to be extended in one direction and to be juxtaposed in a direction transverse to the one direction, and

the pixel electrode being made of a transparent plane-shaped electrode which is formed in a large Dart of the pixel area,

wherein the interposed film is at least one of a protective film and an insulating film; and

wherein the interposed film includes a first protective film made of an inorganic material layer formed to cover the thin film transistor, and a second protective film made of the organic material layer formed to cover the pixel electrode on the first protective film.