Testing device of display module, testing system including the same, and testing method using the same

Patent metadata

Field	Value
Publication number	US-11409395-B2
Application number	US-201916667335-A
Country	US
Kind code	B2
Filing date	Oct 29, 2019
Priority date	Dec 13, 2018
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

A testing device for testing a display module may include touch test pads electrically connected to touch pads of a display module, a first power test pad and a second power test pad electrically connected to a first power pad and a second power pad of the display module, a voltage generator providing a first test power voltage and a second power test voltage to the first power test pad and second power test pad, and a capacitance measurement circuit measuring capacitance between the first power test pad and second power test pad.

First claim

What is claimed is:

1. A testing device, comprising:
touch test pads configured to be electrically connected to touch pads in electrical communication with touch signal lines of a touch-sensing unit of a display module;
a first power test pad and a second power test pad configured to be electrically connected to a first power pad and a second power pad of the display module;
a voltage generator configured to provide a first test power voltage and a second power test voltage to the first power test pad and second power test pad;
a capacitance measurement circuit configured to measure capacitance between the first power test pad and second power test pad; and
a touch testing circuit configured to output touch test signals for testing the touch-sensing unit to the touch test pads.

2. The testing device of claim 1 , wherein the voltage generator changes a voltage level of at least one of the first test power voltage and the second test power voltage, in response to a voltage control signal.

3. The testing device of claim 2 , further comprising:
a connector electrically connecting the touch pads to the touch test pads and electrically connecting the first and second power pads to the first and second power test pads; and
an interface configured to output the voltage control signal in response to a test control signal received from an outside.

4. The testing device of claim 1 , wherein the capacitance measurement circuit is configured to output a capacitance sensing signal corresponding to the measured capacitance.

5. The testing device of claim 1 , wherein an operation of the touch testing circuit outputting the touch test signals and an operation of the voltage generator outputting the first test power voltage and the second power test voltage are executed in parallel.

6. The testing device of claim 5 , wherein the touch test pads, the first and second power test pads, the voltage generator, and the capacitance measurement circuit are provided as a single integrated circuit.

7. The testing device of claim 1 , further comprising a panel testing circuit outputting panel test signals to signal pads of the display module.

8. The testing device of claim 7 , wherein the panel testing circuit comprises:
touch test pads electrically connected to the signal pads of the display module; and
a test signal generator configured to output the panel test signals to the touch test pads.

9. A testing system, comprising:
a display module; and
a testing device,
wherein the display module comprises:
a display panel including a display region and a non-display region adjacent to the display region; and
a touch-sensing unit disposed on the display panel and configured to sense an external input applied to a sensing region overlapped with the display region,
wherein the display panel comprises:
touch pads disposed on the non-display region and electrically connected to the touch-sensing unit; and
a first power pad and a second power pad disposed on the non-display region and electrically connected to the display panel, and
wherein the testing device comprises:
touch test pads electrically connected to the touch pads;
a first power test pad and a second power test pad electrically connected to the first power pad and the second power pad;
a voltage generator configured to provide a first test power voltage and a second power test voltage to the first power test pad and second power test pad;
a capacitance measurement circuit configured to measure capacitance between the first power test pad and second power test pad; and
a touch testing circuit configured to output touch test signals for testing the touch-sensing unit to the touch test pads.

10. The testing system of claim 9 , wherein the voltage generator is configured to change a voltage level of at least one of the first test power voltage and the second test power voltage in response to a voltage control signal.

11. The testing system of claim 10 , further comprising:
a connector electrically connecting the touch pads to the touch test pads and electrically connecting the first and second power pads of the display panel to the first and second power test pads; and
an interface configured to output the voltage control signal in response to a test control signal received from an outside.

12. The testing system of claim 10 , wherein the capacitance measurement circuit is configured to output a capacitance sensing signal corresponding to the measured capacitance.

13. The testing system of claim 10 , wherein the display panel comprises a plurality of pixels, which are arranged in the display region and are connected to a plurality of data lines and a plurality of scan lines, and at least one of the plurality of pixels comprises:
a light-emitting diode including an anode and a cathode;
a first transistor including a first electrode configured to receive a first power voltage, a second electrode electrically connected to the anode of the light-emitting diode, and a gate electrode;
a capacitor including a first electrode connected to the first electrode of the first transistor and a second electrode connected to the gate electrode of the first transistor; and
a second transistor including a first electrode connected to a corresponding one of the plurality of data lines, a second electrode connected to the second electrode of the capacitor, and a gate electrode configured to receive a first scan signal.

14. The testing system of claim 13 , wherein the first electrode of the first transistor is electrically connected to the first power pad, and
the cathode of the light-emitting diode is electrically connected to the second power pad.

15. The testing system of claim 14 , wherein the capacitance measurement circuit is configured to output a capacitance sensing signal corresponding to capacitance between the first electrode of the first transistor and the cathode of the light-emitting diode.

16. A testing method using a testing device including touch test pads electrically connected to touch pads of a touch-sensing unit and a first power test pad and a second power test pad electrically connected to a first power pad and a second power pad of a display panel, the testing method comprising:
providing a first test power voltage and a second power test voltage to the first power test pad and the second power test pad;
measuring capacitance between the first power test pad and second power test pad; and
outputting touch test signals for testing the touch-sensing unit to the touch test pads.

17. The method of claim 16 , further comprising outputting a capacitance sensing signal corresponding to the measured capacitance.

Assignees

• Samsung Display Co Ltd

Inventors

• Lee Il Ho
• Kwon Sanghyuk
• Kim Yeongbin
• Noh Chansik
• Shin Eunchul
• Choi Sangmin

Classifications

• G06F3/0446

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G01R27/2605 Primary

  Measuring capacitance (capacitive sensors G01D5/24) · 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

• G01R31/2825

  in household appliances or professional audio/video equipment (testing LAN's H04L43/50; testing TV systems H04N17/00; testing loudspeakers H04R29/00) · CPC title

• G06F3/044

  by capacitive means · CPC title