Thin film transistor, method of repairing the thin film transistor and display apparatus having the thin film transistor

• US 4,902,638 A
• Filed: 04/24/1989
• Issued: 02/20/1990
• Est. Priority Date: 04/23/1985
• Status: Expired due to Fees

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Muto, Ryujiro
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): NGUYEN, TUAN H
• Application Number:
  US07/342,355
• Time in Patent Office: 302 Days
• Field of Search: 437/51, 437/923, 437/8, 350/332, 350/333, 350/334, 350/336, 357/4, 357/23.7, 357/32, 357/45, 357/41
• US Class Current: 438/4
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/136259 Repairing; Defects
• CPC Class Codes: G02F 1/136268 Switch defects
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 27/13 combined with thin-film or thick-film passive components

Abstract

A thin film transistor is connected to a picture element displaying electrode formed on an insulating base plate so that a voltage is applied to the electrode. The thin film transistor comprises a gate electrode, one or more drain electrodes connected to the picture element displaying electrode and a source bus line which applies a voltage to one or more source electrodes connected thereto, the source bus line functioning by itself as a source electrode, wherein the one drain electrode is formed between the source bus line and one of the one source electrode connected to the source bus line, or between the source electrodes adjacent to each other.

Claims

1. A method of repairing a thin film transistor connected to a picture element displaying electrode formed on an insulating base plate so that a voltage is applied to said electrode, wherein said thin film transistor comprising a gate electrode, at least two drain electrodes, at least one of which is connected to said picture element displaying electrode, a source bus line, a plurality of source electrodes, at least one of said source electrodes adjacent to said one or more drain electrodes connected to said picture element displaying electrode being connected to said source bus line which applies a voltage to said source electrodes, wherein said drain electrodes are formed between said source bus line which functions by itself as a source electrode and one of said source electrodes or between said source electrodes adjacent to each other, each of which is other than said source bus line functioning as a source electrode, characterized in that a faulty portion of any electrode is separated from said source bus line or said picture element displaying electrode, and another set of said drain electrode and said source electrodes are connected to said source bus line and said picture element displaying electrode, if necessary.

2. A method of repairing a thin film transistor according to claim 1, wherein two or more drain electrodes and source electrodes are provided so that said drain electrodes are interposed between said source bus line and one of said source electrodes or between said source electrodes adjacent to each other;

all said drain electrodes are connected to said picture element displaying electrode, and all said source electrodes are connected to said source bus line and wherein any faulty drain electrode of said thin film transistor is separated from said picture element displaying electrode or any faulty source electrode is separated from said source bus line.

3. A method of repairing thin film transistor according to claim 1, wherein two or more drain electrodes and source electrodes are provided so that said drain electrodes are interposed between said source bus line and one of said source electrodes and/or between said source electrodes adjacent to each other;

either of said drain electrodes is connected to said picture element displaying electrode;

other source electrodes other than said source bus line adjacent to said one drain electrode connected to said picture element displaying electrode is connected to said source bus line and wherein any faulty drain electrode of said thin film transistor is separated from said picture element displaying electrode or any faulty source electrode is separated from said source bus line;

another drain electrode without connection with said picture element displaying electrode is connected to the picture element displaying electrode, and source electrodes placed at both sides of said drain electrode are connected to said source bus line.