Method for darkening pixel

• US 20020063844A1
• Filed: 11/27/2001
• Published: 05/30/2002
• Est. Priority Date: 11/28/2000
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsuura, Yoshiaki, Tokunaga, Masahiko, Segawa, Yasuo
• Granted Patent: US 6,778,233 B2
• Time in Patent Office: Days
• US Class Current: 349/187
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G02F 1/136268 Switch defects

Abstract

Peripheries of a contact 26 for connecting a polycrystalline silicon layer 20 to a pixel electrode 28 are cut by a laser to form a cut area 50. By this cut area 50, the polycrystalline silicon layer 20 around the contact 26 is also cut. In consequence, a TFT 24 is separated from the pixel electrode 28 and a supplemental capacitor electrode 32 to reliably accomplish darkening.

Claims

1. A method for darkening a pixel by darkening a defective pixel on a display for controlling the application of a voltage to a corresponding pixel electrode by a thin film transistor disposed for each pixel, wherein:

a part of the pixel electrode is cut by a laser in the vicinity of the contact connecting an electrode of the thin film transistor to the pixel electrode to separate the contact from the pixel electrode and to thereby darken the corresponding pixel.

2. The method for darkening the pixel according to claim 1, wherein the electrode of the thin film transistor in the vicinity of the contact is further cut by the laser to separate the contact from the thin film transistor.

3. The method for darkening the pixel according to claim 1, wherein the display device is a liquid crystal display of a normally black type.

4. The method for darkening the pixel according to claim 1, wherein the pixel electrode on the contact is an island-like conductive portion separated from an ambience.

5. A display device for controlling, by the thin film transistor disposed for each pixel, the application of a voltage to a corresponding pixel electrode, wherein:

a part of the pixel electrode is cut by a laser in the vicinity of the contact connecting an electrode of the thin film transistor to the pixel electrode to separate the contact from the pixel electrode and to thereby darken the corresponding pixel.

6. The display device according to claim 5, wherein the electrode of the thin film transistor in the vicinity of the contact is further cut by the laser to separate the contact from the thin film transistor.

7. The display device according to claim 5, wherein the display device is a liquid crystal display of a normally black type.

8. The display device according to claim 5, wherein the pixel electrode on the contact is an island-like conductive portion separated from an ambience.