Liquid crystal display with TFT and capacitor electrodes with redundant connection

• US 5,517,341 A
• Filed: 06/01/1993
• Issued: 05/14/1996
• Est. Priority Date: 06/01/1992
• Status: Expired due to Term

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Woon-yong, Kim, Dong-gyu, Kim, Sang-soo, Song, Jun-ho, Jang, In-sik
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US08/070,717
• Time in Patent Office: 1,078 Days
• Field of Search: 359/87, 359/59, 359/58, 359/60, 359/67, 359/68
• US Class Current: 349/42
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136263 Line defects
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors

Abstract

An active matrix-type liquid crystal display is described having, for each pixel, a first electrode for of a storage capacitor that is connected to a scanning signal line. The liquid crystal display can be repaired for disconnections and short inferiorities occurring in a crossing portion of scanning signal line. A redundancy correcting line connects the capacitor electrodes of adjacent pixels. Also described is a double scanning signal line. The embodiments using the redundant connecting line and double scanning signal line are both repairable using laser if imperfections exist. Thus, the disconnections and shorts in the crossing portion of wirings can be minimized.

Claims

1. A portion of a liquid crystal display device comprising:

a transparent substrate;

a plurality of scanning signal lines and display signal lines in a matrix configuration disposed on the surface of said transparent substrate, thereby defining a matrix of pixel regions, each pixel region containing a liquid crystal display area;

a pixel electrode disposed in each pixel region and covering said liquid crystal display area;

a thin film transistor disposed in each pixel region having a gate electrode connected to one of said scanning signal lines, a source electrode connected to one of said display signal lines, and a drain electrode connected to said pixel electrode;

a first electrode of storage capacitor disposed in each pixel region that partially overlaps said pixel electrode, said first electrode being connected to one of said scanning signal lines; and

a redundant connecting conductor electrically connecting adjacent first electrodes.

2. A portion of a liquid crystal display according to claim 1, wherein said first electrodes, said scanning signal lines and said redundancy connecting conductors are made of a same type material.

3. A portion of a liquid crystal display according to claim 2, wherein said same type material includes at least one of aluminum, chromium, molybdenum and tantalum.

4. A portion of a liquid crystal display according to claim 3, wherein said same type material has a stacked structure comprised of at least two metals.

5. A portion of a liquid crystal display according to claim 1, wherein said redundancy connecting conductors connect adjacent first electrodes disposed in a row and cross said display signal lines with an insulating layer disposed in between said crossing portions.

6. A portion of a liquid crystal display according to claim 1, wherein said thin film transistor is an inversely staggered type transistor formed substantially at a crossing points of said scanning signal lines with said display signal lines.

7. A portion of a liquid crystal display according to claim 1, wherein each of said first electrodes partially overlaps one of said pixel electrodes along a periphery of said one pixel electrode.

8. A portion of a liquid crystal display according to claim 7, wherein said partial overlap has a width sufficient to substantially prevent leak light.

9. A liquid crystal display comprising:

a front glass substrate having inner and outer surfaces;

a rear glass substrate having inner and outer surfaces, disposed parallel to said front glass substrate and separated therefrom by a predetermined distance, said inner surfaces of each of said front and rear glass substrates facing each other;

a plurality of scanning signal lines and display signal lines in a matrix configuration disposed on the surface of said rear glass substrate, thereby defining a matrix of pixel regions, each pixel region containing an liquid crystal display area;

a pixel electrode disposed in each pixel region and covering said liquid crystal display area;

a thin film transistor disposed in each pixel region having a gate electrode connected to one of said scanning signal lines, a source electrode connected to one of said display signal lines, and a drain electrode connected to said pixel electrode;

a first electrode of a storage capacitor disposed in each pixel region that partially overlaps said pixel electrode, said first electrode being connected to one of said scanning signal lines;

redundancy connecting conductors electrically connecting two adjacent first electrodes;

a light-shielding layer matrix disposed on said inner surface of said front glass substrate for defining a light-transmitting aperture area;

a color filter layer disposed on said inner surface of said front glass substrate, including said light transmitting area;

a transparent electrode formed on said color filter layer; and

a liquid crystal layer injected between said front and rear glass substrates.

10. A liquid crystal display according to claim 9, wherein a border of said light transmitting aperture is substantially in vertical alignment with an inner periphery of said first electrode so that said first electrode functions as a secondary light shielding layer.