Liquid crystal display device

• US 8,284,339 B2
• Filed: 02/19/2009
• Issued: 10/09/2012
• Est. Priority Date: 02/26/2008
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated), Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Inventors: Ochiai, Takahiro, Sasaki, Tohru, Nagata, Tetsuya
• Primary Examiner(s): Glick, Edward
• Assistant Examiner(s): NGUYEN, SANG V
• Application Number:
  US12/379,363
• Publication Number:
  US 20090213290A1
• Time in Patent Office: 1,328 Days
• Field of Search: 348/46, 348/47, 348/48, 348/155, 257/52, 257/57, 257/59
• US Class Current: 349/46
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/13415 Drop filling process
• 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 1/13606 having means for reducing parasitic capacitance
• 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 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence

Abstract

A column for defining the interval between a TFT substrate and an opposed substrate is formed at a crossing point between a drain line and a scanning line. At the crossing point where the column is formed, the drain line is formed to have a wider width to prevent light leakage. Further, at the crossing point where the column is formed, the scanning line is formed to have a narrower width to prevent increase of capacitance between the drain line and the scanning line. The column is formed at a crossing point corresponding to a specific color, e.g., a blue pixel B, so that a difference in transmittance and in characteristic of thin film transistors due to formation of the column is initially compensated.

Claims

1. A liquid crystal display device comprising:

scanning lines;

drain lines;

a TFT substrate;

an opposed substrate placed with a predetermined interval with respect to the TFT substrate; and

liquid crystal enclosed between the TFT substrate and the opposed substrate; and

wherein

a width of one of the drain lines at a crossing point between the drain line and one of the scanning lines is wider than at other portions of the drain line,

a width of the one of the scanning lines at the crossing point between the scanning line and the one of the drain lines is narrower than at other portions of the scanning line,

the TFT substrate includes pixels having TFTs and pixel electrodes, the TFTs including;

a first TFT formed at the crossing point between the one of the drain lines and the one of the scanning lines, and

a second TFT formed at a position adjacent to the crossing point between the one of the drain lines and the one of the scanning line, wherein

the first TFT and the second TFT are electrically connected to each other and electrically connected to the one of the scanning lines, and

a gate width of the first TFT is narrower than a gate width of the second TFT.

2. The liquid crystal display device according to claim 1, wherein the liquid crystal display device is an In Plane Switching type.

3. A liquid crystal display device comprising:

scanning lines;

drain lines;

a TFT substrate;

an opposed substrate placed with a predetermined interval with respect to the TFT substrate;

liquid crystal enclosed between the TFT substrate and the opposed substrate; and

wherein

a width of one of the drain lines at a crossing point between the drain line and one of the scanning lines is narrower than at other portions of the drain line,

a width of one of the scanning lines extending through a crossing point between the scanning line and one of the drain lines is wider than at other portions of the scanning line,

the TFT substrate includes pixels having TFTs and pixel electrodes, the TFTs including;

a first TFT formed at the crossing point between the one of the drain lines and the one of the scanning lines, and

a second TFT formed at a position adjacent to the crossing point between the one of the drain lines and the one of the scanning line, wherein

the first TFT and the second TFT are electrically connected to each other and electrically connected to the one of the scanning lines, and

a gate width of the first TFT is wider than a gate width of the second TFT.

4. The liquid crystal display device according to claim 3, wherein the liquid crystal display device is an In Plane Switching type.