Liquid crystal display apparatus of a lateral direction electric field drive type

• US 6,917,392 B2
• Filed: 12/15/2000
• Issued: 07/12/2005
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: NLT Technologies, Ltd. (Tianma Microelectronics Company Limited)
• Original Assignee: NEC LCD Technologies Limited (Tianma Microelectronics Company Limited)
• Inventors: Miura, Satoshi, Takahashi, Ryuji, Nishida, Shinichi, Ihida, Satoshi, Hannuki, Takahisa, Kuroha, Shouichi
• Primary Examiner(s): Chowdhury, Tarifur R.
• Assistant Examiner(s): Akkapeddi, Prasad
• Application Number:
  US09/738,530
• Publication Number:
  US 20010040646A1
• Time in Patent Office: 1,670 Days
• Field of Search: 349/43, 257/59, 257/72
• US Class Current: 349/43
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]

Abstract

The present invention provides a liquid crystal display apparatus of a lateral direction electric field drive type comprising an array substrate including a plurality of TFTs each having a gate electrode, a gate insulation film, a semiconductor layer, and a source electrode/drain electrode formed on a transparent substrate and an opposing substrate arrange so as to oppose to the array substrate, wherein the semiconductor layer has a width in the gate length direction identical to the gate length.

Claims

1. A liquid crystal display apparatus of a lateral direction electric field drive type comprising:

an array substrate including a plurality of TFTs each having a gate electrode, a gate insulation film, a semiconductor layer, and a source electrode/drain electrode formed on a transparent substrate; and

an opposing substrate arranged so as to oppose to the array substrate;

wherein a boundary of the semiconductor layer includes;

both a portion formed inside an area where the gate electrode and the source electrode or the drain electrode of the TFT overlap, and a portion formed outside the gate electrode and wherein a portion of an edge of the semiconductor layer is formed inside the area where the gate electrode and the source electrode or the drain electrode of the TFT overlap.

2. The liquid crystal display apparatus as claimed in claim 1, wherein the boundary of the semiconductor layer of the TFT is so formed that a portion situated inside the gate electrode is formed on a center part of an overlapping area of the gate electrode and the source electrode or the drain electrode, and portions situated outside the gate electrode are formed on parts corresponding to both ends of the overlapping area.

3. A liquid crystal display apparatus of a lateral direction electric field drive type comprising:

an array substrate including a plurality of TFTs each having a gate electrode, a gate insulation film, a semiconductor layer, and a source electrode/drain electrode formed on a transparent substrate; and

an opposing substrate arranged so as to oppose to the array substrate;

wherein a boundary of the semiconductor layer includes;

both a portion formed inside an area where the gate electrode and the source electrode or the drain electrode of the TFT overlap, and a portion formed outside the gate electrode and wherein the semiconductor layer of the TFT is shaped as a concavity by removing a portion of a side which does not overlap the source electrode or the drain electrode.

7. The liquid crystal display apparatus as claimed in claim 3, wherein the boundary of the semiconductor layer of the TFT is so formed that a portion situated inside the gate electrode is formed on a center part of an overlapping area of the gate electrode and the source electrode or the drain electrode, and portions situated outside the gate electrode are formed on parts corresponding to both ends of the overlapping area.

4. A liquid crystal display apparatus comprising:

an array substrate including a plurality of TFTs each having a gate electrode, a gate insulation film, a semiconductor layer, and a source electrode/drain electrode formed on a transparent substrate;

an opposing substrate arranged so as to oppose to the array substrate; and

a common electrode arranged on a side of the opposing substrate;

wherein a boundary of the semiconductor layer includes;

both a portion formed inside an area where the gate electrode and the source electrode or the drain electrode of the TFT overlap, and a portion formed outside the gate electrode and wherein a portion of an edge of the semiconductor layer is formed inside the area where the gate electrode and the source electrode or the drain electrode of the TFT overlap.

5. The liquid crystal display apparatus as claimed in claim 4, wherein the boundary of the semiconductor layer of the TFT is so formed that a portion situated inside the gate electrode is formed on a center part of an overlapping area of the gate electrode and the source electrode, and portions situated outside the gate electrode are formed on parts corresponding to both ends of the overlapping area.

6. A liquid crystal display apparatus comprising:

an array substrate including a plurality of TFTs each having a gate electrode, a gate insulation film, a semiconductor layer, and a source electrode/drain electrode formed on a transparent substrate;

an opposing substrate arranged so as to oppose to the array substrate; and

a common electrode arranged on a side of the opposing substrate;

wherein a boundary of the semiconductor layer includes;

both a portion formed inside an area where the gate electrode and the source electrode or the drain electrode of the TFT overlap, and a potion formed outside the gate electrode and wherein the semiconductor layer of the TFT is shaped as a concavity by removing a portion of a side which does not overlap the source electrode or the drain electrode.

8. The liquid crystal display apparatus as claimed in claim 6, wherein the boundary of the semiconductor layer of the TFT is so formed that a portion situated inside the gate electrode is formed on a center part of an overlapping area of the gate electrode and the source electrode, and portions situated outside the gate electrode are formed on parts corresponding to both ends of the overlapping area.