OLED pixel driving circuit, electrostatic discharge protection circuit and detection method

Patent metadata

Field	Value
Publication number	US-9640097-B2
Application number	US-201414538773-A
Country	US
Kind code	B2
Filing date	Nov 11, 2014
Priority date	Jun 30, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

An OLED pixel driving circuit is disclosed. The pixel driving circuit includes a plurality of interlaced scanning and data lines, and a first defect detection unit electrically connected to a first endpoint of at least one of the scanning lines, and the data lines. The first endpoint is located at one end of the at least one scanning line or data line.

First claim

What is claimed is:

1. An organic light-emitting diode (OLED) pixel driving circuit, comprising:
a plurality of interlaced scanning and data lines; and
a first defect detection unit electrically connected to a first endpoint of at least one of:
a) the scanning lines, and
b) the data lines,
wherein the first endpoint is located at one end of the at least one scanning line or data line,
the first defect detection unit comprises an organic light-emitting diode for detecting a defect in the at least one scanning line or data line, and
the organic light-emitting diode comprises an anode disposed in the same layer as the data line or the scanning line and disposed on a substrate; an organic light-emitting layer covering the anode; and a cathode covering the organic light-emitting layer, wherein the cathode of the organic light-emitting diode is connected to a common ground terminal.

2. The pixel driving circuit according to claim 1 , wherein each data line is electrically connected to the first defect detection unit.

3. The pixel driving circuit according to claim 1 , wherein each scanning line is electrically connected to the first defect detection unit.

4. The pixel driving circuit according to claim 1 , further comprising:
an electrostatic discharge protection circuit disposed at the first endpoint of the data line or the scanning line; and
a second defect detection unit disposed in the electrostatic discharge protection circuit.

5. The pixel driving circuit according to claim 4 , wherein the electrostatic discharge protection circuit further comprises:
an electrostatic discharge unit configured to receive a voltage from the data line or the scanning line of the pixel driving circuit and to provide an electrostatic protection,
a power supply line, and
a switch transistor,
wherein the second defect detection unit is connected to a gate of the switch transistor through the power supply line, wherein the second defect detection unit is connected to a first electrode of the switch transistor, and wherein a second electrode of the switch transistor is connected to the data line or the scanning line of the pixel driving circuit.

6. The pixel driving circuit according to claim 5 , wherein the second defect detection unit is an organic light-emitting diode having an anode connected to the gate of the switch transistor and a cathode connected to the first electrode of the switch transistor.

7. A display panel, comprising:
a scanning driver connected to a plurality of scanning lines at second endpoints of the scanning lines and configured to provide a scanning signal to the scanning lines;
a data driver connected to a plurality of data lines at second endpoints of the data lines and configured to provide a data signal to the data lines; and
a plurality of pixel driving circuits arranged in a matrix, wherein the second endpoint of each data line or scanning line is located at one end of the data line or the scanning line,
wherein the pixel driving circuits each comprises a first defect detection unit electrically connected to a first endpoint of at least one of:
a) the scanning lines, and
b) the data lines, and
wherein the first endpoint is located at another end of the at least one scanning line or data line,
the first defect detection unit comprises an organic light-emitting diode for detecting a defect in the at least one scanning line or data line, and
the organic light-emitting diode comprises an anode disposed in the same layer as the data line or the scanning line and disposed on a substrate; an organic light-emitting layer covering the anode; and a cathode covering the organic light-emitting layer, wherein the cathode of the organic light-emitting diode is connected to a common ground terminal.

8. The display panel according to claim 7 , wherein each data line is electrically connected to the first defect detection unit.

9. The display panel according to claim 7 , wherein each scanning line is electrically connected to the first defect detection unit.

10. A method of detecting a defect a display panel, the display panel comprising a scanning driver connected to a plurality of scanning lines at second endpoints of the scanning lines and configured to provide a scanning signal to the scanning lines, a data driver connected to a plurality of data lines at second endpoints of the data lines and configured to provide a data signal to the data lines, and a plurality of pixel driving circuits arranged in a matrix, wherein the second endpoint of each data line or scanning line is located at one end of the data line or the scanning line, wherein the pixel driving circuits each comprises a first defect detection unit electrically connected to a first endpoint of at least one of the scanning lines, and the data lines, and the first endpoint is located at another end of the at least one scanning line or data line, wherein the first defect detection unit comprises an organic light-emitting diode for detecting a defect in the at least one scanning line or data line, and the organic light-emitting diode comprises an anode disposed in the same layer as the data line or the scanning line and disposed on a substrate; an organic light-emitting layer covering the anode; and a cathode covering the organic light-emitting layer, and wherein the cathode of the organic light-emitting diode is connected to a common ground terminal, the method comprising:
providing an optical detection device;
at least one of:
a) sending, by a scanning line, a detection signal to a defect detection unit corresponding to rows, and
b) sending, by a data line, a detection signal to a defect detection unit corresponding to columns, wherein the defect detection unit comprises an organic light-emitting diode;
detecting, by the optical detection device, whether luminous intensity of the organic light-emitting diode corresponding to the data line and/or the scanning line of a pixel driving circuit reaches a valid predetermined value; and
determining that the data line or the scanning line corresponding to the organic light-emitting diode has a defect in response to the organic light-emitting diode having a luminous intensity less than the predetermined value.

11. The defect detection method according to claim 10 , wherein detection time lasts no more than 60 seconds after the detection begins.

12. The defect detection method according to claim 10 , wherein a predetermined value of the luminous intensity is set as approximately 4000 candelas.

Assignees

• Shanghai Tianma Am-Oled Co Ltd
• Tianma Microelectronics Co Ltd
• Shanghai Tianma Am-Oled Co Ltd

Inventors

• Cai Tao

Classifications

• G09G2330/10

  Dealing with defective pixels · CPC title

• G09G3/3233

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G2330/08

  Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared · CPC title

• G09G2330/12

  Test circuits or failure detection circuits included in a display system, as permanent part thereof · CPC title

• G09G3/006 Primary

  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 title