In-plane switching transflective liquid crystal display device with the pixel electrode elecrically coupled to the active element in a portion defining a clearance between the first electrodes for the transmission and reflective sections

• US 7,826,015 B2
• Filed: 04/05/2007
• Issued: 11/02/2010
• Est. Priority Date: 04/12/2006
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Ochiai, Takahiro, Miyazawa, Toshio, Sasaki, Tohru, Nakao, Takayuki, Maki, Masahiro
• Primary Examiner(s): Schechter, Andrew
• Assistant Examiner(s): Kim, Dennis Y
• Application Number:
  US11/783,071
• Publication Number:
  US 20070241332A1
• Time in Patent Office: 1,307 Days
• Field of Search: 349/114, 349/141
• US Class Current: 349/114
• CPC Class Codes: G02F 1/133555 Transflectors
• 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 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 2201/40 Arrangements for improving the aperture ratio
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body

Abstract

A liquid crystal display device having a liquid crystal display panel includes a first substrate, a second substrate, and liquid crystal interposed between the first and second substrates. The first substrate includes an active element, a first insulating film formed on the active element, a plurality of first electrodes disposed on the first insulating film, a second insulating film disposed on the first electrodes, and a pixel electrode disposed on the second insulating film. The pixel electrode is electrically coupled to the active element via a portion defining a contact hole formed in a portion defining a clearance between the plurality of first electrodes.

Claims

1. A liquid crystal display device including a liquid crystal display panel, comprising:

a first substrate, the first substrate including;

an active element;

a first insulating film formed on the active element;

a plurality of first electrodes disposed on the first insulating film;

a second insulating film disposed on the first electrodes; and

a pixel electrode disposed on the second insulating film;

a second substrate; and

liquid crystal interposed between the first and second substrates,

wherein the liquid crystal display panel has a plurality of subpixels;

each of the plurality of subpixels has a transmission section and a reflection section;

the pixel electrode is shared by the transmission section and the reflection section in each of the subpixels;

the first electrodes are divided into a first electrode for the transmission section in the transmission section and a first electrode for the reflection section in the reflection section;

the first electrode for the transmission section and the first electrode for the reflection section being insulated from each other;

a voltage different from the first electrode for the reflection section is applied to the first electrode for the transmission section;

the pixel electrode is electrically coupled to the active element via a portion defining a contact hole formed in a portion defining a clearance between the first electrode for the transmission section and the first electrode for the reflection section in each of the subpixels.

2. The liquid crystal display device according to claim 1,

wherein the first insulating film has a portion defining a first contact hole formed in a portion defining a clearance between the first electrode for the transmission section and the first electrode for the reflection section;

the second insulating film is formed between the first electrode and the pixel electrode and inside the portion defining a first contact hole;

a portion defining a second contact hole is formed in the second insulating film inside the portion defining a first contact hole; and

the pixel electrode is electrically coupled to the active element via the portion defining a second contact hole.

3. The liquid crystal display device according to claim 1,

wherein the pixel electrode includes:

a connection; and

a comb-shaped electrode for the transmission section and a comb-shaped electrode for the reflection section, the comb-shaped electrodes being formed on both sides of the connection;

the portion defining a contact hole is formed in a region of the connection; and

the connection is electrically coupled to the active element via the portion defining a contact hole.

4. The liquid crystal display device according to claim 3,

wherein the first substrate further includes a video line disposed below the first insulating film and electrically coupled to the active element;

the video line is formed so that a portion of the video line in which the connection of the pixel electrode is formed is wider; and

if the video line and the pixel electrode are projected on the first substrate from a direction orthogonal to the liquid crystal display panel, the wider portion of the video line and an edge of the connection of the pixel electrode overlap each other.

5. The liquid crystal display device according to claim 1,

wherein portions of edges of the first electrodes in which the portion defining a clearance is formed and in which the portion defining a contact hole is formed each have a recess.

6. The liquid crystal display device according to claim 1,

wherein the pixel electrode, the first electrode, and the second insulating film form a holding capacitance.

7. The liquid crystal display device according to claim 1,

wherein the pixel electrode is a transparent electrode.

8. The liquid crystal display device according to claim 1,

wherein the first electrodes include a transparent electrode.

9. The liquid crystal display device according to claim 1,

wherein the first electrodes include a reflection electrode.

10. The liquid crystal display device according to claim 1,

wherein the first electrodes include a transparent electrode and a reflection electrode.

11. The liquid crystal display device according to claim 1,

wherein the first electrodes are counter electrodes;

and

the liquid crystal is driven by an electric field generated by the first electrodes and the pixel electrode.