Method and device for detecting defect of display panel

• US 9,978,296 B2
• Filed: 06/19/2015
• Issued: 05/22/2018
• Est. Priority Date: 10/30/2014
• Status: Expired due to Fees

• Current Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Original Assignee: Beijing BOE Optoelectronics Technology Co Ltd. (BOE Technology Group Co., Ltd.), BOE Technology Group Co., Ltd.
• Inventors: Zhang, Zhengxin, Xu, Shuai, Ma, Jingshan
• Primary Examiner(s): Tang, Minh N
• Application Number:
  US14/744,434
• Publication Number:
  US 20160125776A1
• Time in Patent Office: 1,068 Days
• CPC Class Codes: G01R 1/0416 Connectors, terminals G01R1/0425 and G01R1/0433 take precedence; with measurement function for battery poles G01R31/364
• CPC Class Codes: G09G 2330/10 Dealing with defective pixels
• 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

Abstract

A method and device for detecting a defect of a display panel, the method comprises steps of: connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal; providing a preset voltage between the first detecting terminal and the second detecting terminal; and, detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within a predetermined time are less than a preset current threshold, and if not, then determining there is a defect on the display panel. The present disclosure can implement effective detection and interception of a progressive defect or badness in the display panel.

Claims

1. A method for detecting a defect of a display panel, it comprises steps of:

connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal;

providing a preset voltage between the first detecting terminal and the second detecting terminal by a voltage providing unit; and

detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within a predetermined time are less than a preset current threshold by a detecting unit, and if not, then determining there is a defect on the display panel.

2. The method according to claim 1, wherein, providing the preset voltage between the first detecting terminal and the second detecting terminal by a voltage providing unit comprises:

electrically connecting the first detecting terminal to a first terminal of a predetermined resistor, and electrically connecting the second detecting terminal to a second terminal of a predetermined constant voltage source, a second terminal of the predetermined resistor being connected with a first terminal of the predetermined constant voltage source.

3. The method according to claim 2, wherein, detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within the predetermined time are less than the preset current threshold by a detecting unit, and if not, then determining there is a defect on the display panel comprises:

measuring voltage across the predetermined resistor, determining whether a magnitude of the voltage within a predetermined time is less than a product of the current threshold and a resistance value of the predetermined resistor, and if not, then determining there is a defect on the display panel.

4. The method according to claim 3, wherein, connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal comprises:

controlling on or off of a switching element located between each electrical test pad and the first detecting terminal or the second detecting terminal, so as to connect at least one electrical test pad on the display panel to the first detecting terminal, and connect another at least one electrical test pad on the display panel to the second detecting terminal.

5. The method according to claim 2, wherein, detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within the predetermined time are less than the preset current threshold by a detecting unit, and if not, then determining there is a defect on the display panel comprises:

electrically connecting the first detecting terminal to an input terminal of a latch, which is configured to maintain an output of a high level after the voltage at the input terminal is greater than or equal to the product of the current threshold and the resistance value of the predetermined resistor; and

determining whether the output of the latch within a predetermined time is kept at a low level, and if not, then determining there is a defect on the display panel.

6. The method according to claim 5, wherein, connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal comprises:

controlling on or off of a switching element located between each electrical test pad and the first detecting terminal or the second detecting terminal, so as to connect at least one electrical test pad on the display panel to the first detecting terminal, and connect another at least one electrical test pad on the display panel to the second detecting terminal.

7. The method according to claim 1, wherein, connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal comprises:

controlling on or off of a switching element located between each electrical test pad and the first detecting terminal or the second detecting terminal, so as to connect at least one electrical test pad on the display panel to the first detecting terminal, and connect another at least one electrical test pad on the display panel to the second detecting terminal.

8. A device for detecting a defect of a display panel, comprising:

a first detecting terminal and a second detecting terminal for being electrically connected with electrical test pads on the display panel, wherein after the electrical test pads are electrically connected with the first detecting terminal or the second detecting terminal, both the first detecting terminal and the second detecting terminal are electrically connected with at least one electrical test pad;

a voltage providing unit configured to provide a preset voltage between the first detecting terminal and the second detecting terminal after the electrical test pads are electrically connected with the first detecting terminal or the second detecting terminal;

a detecting unit configured to, after the voltage providing unit provides the preset voltage between the first detecting terminal and the second detecting terminal, detect whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within a predetermined time are less than a preset current threshold, and if not, then determining there is a defect on the display panel.

9. The device according to claim 8, wherein, the voltage providing unit comprises a predetermined resistor and a predetermined constant voltage source, a second terminal of the predetermined resistor is connected with a first terminal of the predetermined constant voltage source;

and

the first detecting terminal is connected with a first terminal of the predetermined resistor, and the second detecting terminal is connected with a second terminal of the predetermined constant voltage source.

10. The device according to claim 9, wherein, the detecting unit comprises:

a means for measuring voltage across the predetermined resistor; and

a means for determining whether a magnitude of the voltage within a predetermined time is less than a product of the current threshold and a resistance value of the predetermined resistor, and if not, and then determining there is a defect on the display panel.

11. The device according to claim 9, wherein, the detecting unit comprises:

a latch whose input terminal is connected with the first detecting terminal, configured to maintain an output of a high level after a voltage at the input terminal is greater than or equal to the product of the current threshold and the resistance value of the predetermined resistor; and

a means for determining whether the output of the latch is kept at a low level within a predetermined time, and if not, and then determining there is a defect on the display panel.

12. The device according to claim 9, wherein, there is included a switching circuit between the first detecting terminal and the electrical test pad and between the second detecting terminal and the electrical test pad, the switching circuit comprising:

a switching element provided between the electrical test pad and the first detecting terminal or the second detecting terminal.

13. The device according to claim 9, the device further comprises a probe connected with the electrical test pad, wherein the first detecting terminal and the second detecting terminal are used for being connected with the electrical test pad on the display panel through the probe.

14. The device according to claim 8, wherein, there is included a switching circuit between the first detecting terminal and the electrical test pad and between the second detecting terminal and the electrical test pad, the switching circuit comprising:

a switching element provided between the electrical test pad and the first detecting terminal or the second detecting terminal.

15. The device according to claim 8, the device further comprises a probe connected with the electrical test pad, wherein the first detecting terminal and the second detecting terminal are used for being connected with the electrical test pad on the display panel through the probe.

16. A non-transitory computer-readable recording medium having embodied thereon a computer program to execute the following steps:

connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal;

providing a preset voltage between the first detecting terminal and the second detecting terminal by a voltage providing unit; and

detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within a predetermined time are less than a preset current threshold by a detecting unit, and if not, then determining there is a defect on the display panel.

17. The non-transitory computer-readable recording medium according to claim 16, wherein, providing the preset voltage between the first detecting terminal and the second detecting terminal by a voltage providing unit comprises:

electrically connecting the first detecting terminal to a first terminal of a predetermined resistor, and electrically connecting the second detecting terminal to a second terminal of a predetermined constant voltage source, a second terminal of the predetermined resistor being connected with a first terminal of the predetermined constant voltage source.

18. The non-transitory computer-readable recording medium according to claim 17, wherein, detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within the predetermined time are less than the preset current threshold by a detecting unit, and if not, then determining there is a defect on the display panel comprises:

measuring voltage across the predetermined resistor, determining whether a magnitude of the voltage within a predetermined time is less than a product of the current threshold and a resistance value of the predetermined resistor, and if not, then determining there is a defect on the display panel.

19. The non-transitory computer-readable recording medium according to claim 17, wherein, detecting whether magnitudes of currents passing through the first detecting terminal and the second detecting terminal within the predetermined time are less than the preset current threshold by a detecting unit, and if not, then determining there is a defect on the display panel comprises:

electrically connecting the first detecting terminal to an input terminal of a latch, which is configured to maintain an output of a high level after the voltage at the input terminal is greater than or equal to the product of the current threshold and the resistance value of the predetermined resistor; and

determining whether the output of the latch within a predetermined time is kept at a low level, and if not, then determining there is a defect on the display panel.

20. The non-transitory computer-readable recording medium according to claim 16, wherein, connecting at least one electrical test pad on the display panel to a first detecting terminal, and connecting another at least one electrical test pad on the display panel to a second detecting terminal comprises:

controlling on or off of a switching element located between each electrical test pad and the first detecting terminal or the second detecting terminal, so as to connect at least one electrical test pad on the display panel to the first detecting terminal, and connect another at least one electrical test pad on the display panel to the second detecting terminal.