Electro-optical device substrate, active matrix substrate and method for inspecting electro-optical device substrate

• US 6,670,953 B1
• Filed: 05/24/2000
• Issued: 12/30/2003
• Est. Priority Date: 10/16/1998
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Ozawa, Tokuro
• Primary Examiner(s): Shankar, Vijay
• Assistant Examiner(s): Dharia, Prabodh M.
• Application Number:
  US09/555,053
• Time in Patent Office: 1,315 Days
• Field of Search: 345/87, 345/89, 345/90, 345/91, 345/92, 345/93, 345/94, 345/95, 345/96, 345/97, 345/98, 345/99, 345/100, 345/211, 349/54, 324/50, 324/770, 438/54
• US Class Current: 345/211
• CPC Class Codes: G02F 1/1309 Repairing; Testing
• CPC Class Codes: G09G 2300/08 Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
• CPC Class Codes: G09G 2310/0267 Details of drivers for scan electrodes, other than drivers for liquid crystal, plasma or OLED displays
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• CPC Class Codes: G09G 2330/08 Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared
• CPC Class Codes: G09G 2330/12 Test circuits or failure detection circuits included in a display system, as permanent part thereof
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

The invention provides a first gate-line breakage inspection process in which a signal for switching on each thin-film transistor is supplied to each gate of a first left-side transistor sequence, and a current value of a current flowing through two gate lines conducted by each thin-film transistor is measured. In a second gate-line breakage inspection process, a signal for switching on each thin-film transistor is supplied to each gate of a second left-side transistor sequence, and a current value of a current flowing through two gate lines conducted by each thin-film transistor is measured. Subsequently, it is determined whether any gate line is defective based on the inspection results of the first gate-line breakage inspection process and the second gate-line breakage inspection process.

Claims

1. An electro-optical device substrate, comprising:

a plurality of wires;

a plurality of switching devices interposed between each parallel pair of the wires, wherein the each pair of the wires comprise adjacent two wires, and each of the switching devices belongs to one of a first group and a second group, and one of the adjacent switching devices interposed between a first wire and adjacent one wire and another one of the adjacent switching devices interposed between the first wire and adjacent another wire belongs to different groups, and the switching devices belonging to the groups are switched on/off in units of each group; and

a shift register that serially shifts data supplied to the each pair of the wires,

the electro-optical device substrate allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another.

2. An electro-optical device substrate, comprising:

a plurality of wires, each wire including a first end and a second end;

a plurality of first switching devices interposed near the first end between each of the adjacent parallel wires, each of the first switching devices belonging to one of a first group and a second group, the adjacent switching devices belonging to different groups, and the switching devices belonging to the groups being switched on/off in units of each group;

a plurality of second switching devices interposed near the second end between each of the adjacent wires, each of the switching devices belonging to one of a third group and a fourth group, the adjacent switching devices belonging to different groups, and the switching devices belonging to the groups being switched on/off in units of each group;

a first power-supply that allows a current to pass through pairs of wires connected in series via the first switching devices or that applies a voltage to the pairs of wires; and

a second power-supply that allows a current to pass through pairs of wires connected in series via the second switching devices or that applies a voltage to the pairs of wires.

3. The electro-optical device substrate as set forth in claim 2, each of the first power-supply and the second power-supply being a circuit operable as a driving device for the a plurality of wires.

4. The electro-optical device substrate as set forth in claim 3, each of the first power-supply and the second power-supply comprising a shift register for serially shifting data commanding each wire to be driven, and 3-state buffers each corresponding to each stage of the shift register, an output terminal of each 3-state buffer being connected to the end of each wire.

5. An active matrix substrate, comprising:

a plurality of selection lines;

a plurality of signal lines;

a switching device connected to each of the selection lines and the signal lines;

a pixel electrode connected to each switching device;

a shift register that serially shifts signal setting on/off of data supply to the plurality of signal lines;

a plurality of switching devices interposed between each pair of the signal lines, wherein the each pair of the signal lines comprise adjacent two signal lines, and each of the switching devices belongs to one of a first group and a second group, and one of the adjacent switching devices interposed between a first signal line and adjacent one signal line and another one of the adjacent switching devices interposed between the first signal line and adjacent another signal line belongs to different groups, and the switching devices belonging to the groups are switched on/off in units of each group, and the plurality of switching devices interposed between one pair of the signal lines including a signal line in which the shift register supply the data to the signal line being switched on, and the plurality of switching devices interposed between another pair of the signal lines including the signal line being switched off; and

a signal line driving circuit operable for driving each signal line, the signal line driving circuit allowing a current to pass through the each pair of the signal lines connected in series via the switching devices switched on or applying a voltage to the each pair of the signal lines, and allowing a current to pass through the each pair of the signal lines connected in series via the switching devices switched on or applying a voltage to the each pair of the signal lines based on the signal which is shifted serially by the shift register one after another.

6. An active matrix substrate, comprising:

a plurality of selection lines, each selection line having a first end and a second end;

a plurality of signal lines;

a switching device connected to each of the selection lines and the signal lines;

a pixel electrode connected to an end of each switching device;

a plurality of first switching devices interposed near the first end between each of the adjacent selection lines, each of the first switching devices belonging to one of a first group and a second group, the adjacent switching devices belonging to different groups, and the switching devices belonging to the groups being switched on/off in units of each group;

a plurality of second switching devices interposed near the second end between each of the adjacent selection lines, each of the switching devices belonging to one of a third group and a fourth group, the adjacent switching devices belonging to different groups, and the switching devices belonging to the groups being switched on/off in units of each group;

a first selection line driving circuit that drives each of the selection lines, the first selection line driving circuit allowing a current to pass through pairs of selection lines connected in series via the first switching devices or applying a voltage to the pairs of wires; and

a second selection line driving circuit driving each of the selection lines, the second selection line driving circuit allowing a current to pass through pairs of selection lines connected in series via the second switching devices or applying a voltage to the pairs of wires.

7. An electro-optical device substrate, comprising:

a plurality of wires formed by alternately arranging individual first wires and individual second wires which are parallel to the first wires;

a plurality of switching devices interposed between each of the first wires and each of the second wires which are adjacent to each of the first wires at one side; and

a power-supply that allows a current to pass through pairs of wires connected in series via each of the switching devices or that applies a voltage to the pairs of wires.

8. A method for inspecting an electro-optical device substrate including a plurality of wires and a plurality of switching devices interposed between each pair of the adjacent parallel wires, and a shift register for serially shifting data supplied to the each pair of the wires, and dividing the switching devices into a first group and a second group to be one of switching devices interposed between a first wire and adjacent one wire and another one of the adjacent switching devices interposed between the first wire and adjacent another wire belongs to different groups, the method comprising:

a first wire inspection step of switching on the switching devices belonging to the first group and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another, thus determining the presence of a defect in the each pair of the wires;

a second wire inspection step of switching on the switching devices belonging to the second group and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another, thus determining the presence of a defect in the each pair of the wires; and

a defect determining step of determining a defective wire based on the determination result of the first wire inspection step and the determination result of the second wire inspection step.

9. A method for inspecting an electro-optical device substrate including a plurality of wires, each wire having a first end and a second end, a plurality of first switching devices interposed near the first end between each of the adjacent parallel wires, a plurality of second switching devices interposed near the second end between each of the adjacent wires, a first power-supply connected to the first ends of the plurality of wires, and a second power-supply connected to the second ends of the plurality of wires, the method comprising:

dividing the plurality of first switching devices into a first group and a second group so that the adjacent first switching devices belong to different groups;

dividing the plurality of second switching devices into a third group and a fourth group so that the adjacent second switching devices belong to different groups;

performing one a first step and a second step, the first step including inspecting a first wire by switching on the switching devices belonging to the first group and allowing a current to pass through pairs of wires connected in series via the switching devices or by applying a voltage to the pairs of wires using the second power-supply, thus determining the presence of a defect in the pairs of wires, and a inspecting a second wire by switching on the switching devices belonging to the second group and allowing a current to pass through pairs of wires connected in series via the switching devices or by applying a voltage to the pairs of wires using the second power-supply, thus determining the presence of a defect in the pairs of wires;

the second step including inspecting a first wire by switching on the switching devices belonging to the third group and allowing a current to pass through pairs of wires connected in series via the switching devices or by applying a voltage to the pairs of wires using the first power-supply, thus determining the presence of a defect in the pairs of wires, and inspecting a second wire by switching on the switching devices belonging to the fourth group and allowing a current to pass through pairs of wires connected in series via the switching devices or by applying a voltage to the pairs of wires using the first power-supply, thus determining the presence of a defect in the pairs of wires; and

determining a defective wire based on the determination result of the first wire inspection step and the determination result of the second wire inspection step.

10. The method for inspecting an electro-optical device substrate as set forth in claim 9, further comprising:

a determining step, prior to the inspection steps, of determining whether the first power-supply and the second power-supply function correctly.

11. The method for inspecting an electro-optical device substrate as set forth in claim 10, the first step being performed when it is determined by the determining step that the first power-supply is defective, the second step being performed when it is determined by the determining step that the second power-supply is defective.

12. The method for inspecting an electro-optical device substrate as set forth in claim 11, neither of the first step nor the second step being performed when it is determined by the determining step that both the first power-supply and the second power-supply are defective.

13. A method for inspecting an electro-optical device substrate including a plurality of wires formed by alternately arranging individual first wires and individual second wires and a plurality of switching devices interposed between each of the first wires and each of the second wires which are adjacent to each of the first wires at one side, the method comprising:

inspecting the wires by switching on the plurality of switching devices and allowing a current to pass through pairs of wires connected in series via the switching devices or by applying a voltage to the pairs of wires, thus determining the presence of a defect in the pairs of wires.

14. An electro-optical device substrate, comprising:

a plurality of wires formed by alternately arranging individual first wires and individual second wires which are parallel to the first wires; and

a shift register for serially shifting data supplied to the each pair of the wires,

a plurality of switching devices interposed between each of the first wires and each of the second wires adjacent to each of the first wires at one side, and a plurality of switching devices not interposed between each of the first wires and each of the second wires adjacent to each of the first wires at another side, and

the electro-optical device substrate allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another.

15. An electro-optical device substrate comprising:

a plurality of wires;

a plurality of switching devices interposed between each parallel pair of the wires, wherein the each pair of the wires comprising adjacent two wires, and one of the adjacent switching devices interposed between a first wire and adjacent one wire and another one of the adjacent switching devices interposed between the first wire and adjacent another wire; and

a shift register for serially shifting data supplied to the each pair of the wires,

the electro-optical device substrate switching on the switching devices interposed between one pair of the wires including a wire in which the shift register supply the data to the wire, and switching off the switching devices interposed between another pair of the wires including the wire, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another.

16. A method for inspecting an electro-optical device substrate including a plurality of wires formed by alternately arranging individual first wires and individual second wires which are parallel to the first wires and a shift register for serially shifting data supplied to the each pair of the wires and a plurality of switching devices interposed between each of the first wires and each of the second wires which are adjacent to each of the first wires at one side, and a plurality of switching devices not interposed between each of the first wires and each of the second wires which are adjacent to each of the first wires at another side, said method comprising:

a switching step of switching on the switching devices; and

a wire inspection step of allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another, thus determining the presence of a defect in the each pair of the wires.

17. A method for inspecting an electro-optical device substrate including a plurality of wires and a plurality of switching devices interposed between each parallel pair of the wires, wherein the each pair of the wires comprising adjacent two wires, and one of the adjacent switching devices interposed between a first wire and adjacent one wire and another one of the adjacent switching devices interposed between the first wire and adjacent another wire and a shift register for serially shifting data supplied to the each pair of the wires, said method comprising:

a switching step of switching on the switching devices interposed between one pair of the wires including a wire in which the shift register supply the data to the wire, and switching off the switching devices interposed between another pair of the wires including the wire; and

a wire inspection step of allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires, and allowing a current to pass through the each pair of the wires connected in series via the switching devices switched on or applying a voltage to the first wire of the each pair of the wires based on the data which is shifted for serially by the shift register one after another, thus determining the presence of a defect in the each pair of the wires.