APPARATUS AND METHOD FOR SENSING DISPLAY PANEL

• US 20180068618A1
• Filed: 09/08/2016
• Published: 03/08/2018
• Est. Priority Date: 09/08/2016
• Status: Active Grant

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Lin, Chun-Chieh, Liu, Shang-I, Chang, Hua-Gang
• Granted Patent: US 10,068,528 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/043 Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2310/0286 Details of a shift registers arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/043 Preventing or counteracting the effects of ageing
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: G09G 3/3266 Details of drivers for scan electrodes
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes

Abstract

An apparatus and a method for sensing a display panel are provided. The apparatus includes a gate driving circuit and a sensing circuit. The gate driving circuit may scan the scan-lines during a plurality of scan-line periods within a frame period. The sensing circuit is coupled to a plurality of pixel circuits. A corresponding scan-line period of the scan-line periods is divided into a test data period and a display data period. In the test data period, the sensing circuit controls a corresponding pixel circuit to receive the test data, and the sensing circuit senses the electrical characteristic of the corresponding pixel circuit. In the display data period, the sensing circuit controls the corresponding pixel circuit to receive the display data from a corresponding data line, and the sensing circuit does not sense the corresponding pixel circuit.

Claims

1. An apparatus for sensing a display panel, wherein the display panel comprises a plurality of scan lines, a plurality of data lines and a plurality of pixel circuits, a data input terminal and a gate terminal of a corresponding pixel circuit of the pixel circuits are coupled to a corresponding data line of the data lines and a corresponding scan line of the scan lines respectively, and the apparatus comprising:

a gate driving circuit coupled to the scan lines, and configured to define a plurality of scan-line periods in a frame period to scan the scan lines, wherein a corresponding scan-line period within the scan-line periods corresponds to the corresponding scan line; and

a sensing circuit coupled to the pixel circuits;

wherein in a test data period within the corresponding scan-line period, the sensing circuit controls the corresponding pixel circuit to receive test data, and the sensing circuit senses an electrical characteristic of the corresponding pixel circuit; and

wherein in a display data period within the same corresponding scan-line period, the sensing circuit controls the corresponding pixel circuit to receive display data from the corresponding data line, and the sensing circuit does not sense the corresponding pixel circuit.

2. The apparatus as claimed in claim 1, wherein the gate driving circuit comprises:

a plurality of shift registers series-connected to one another, wherein a plurality of output terminals of the shift registers are one-on-one coupled to the scan lines.

3. The apparatus as claimed in claim 1, wherein the corresponding pixel circuit comprises:

a first switch, wherein a control terminal of the first switch is coupled to the corresponding scan line;

a switch circuit, wherein an output terminal of the switch circuit is coupled to a first terminal of the first switch, the test data of a first input terminal of the switch circuit is transmitted to the first terminal of the first switch in the test data period, and the display data of a second input terminal of the switch circuit is transmitted to the first terminal of the first switch in the display data period;

a transistor, wherein a control terminal of the transistor is coupled to a second terminal of the first switch, and a first terminal of the transistor is coupled to a first voltage;

an organic light emitting diode (OLED), wherein a first terminal of the OLED is coupled to a second terminal of the transistor, and a second terminal of the OLED is coupled to a second voltage; and

a second switch, wherein a first terminal of the second switch is coupled to the second terminal of the transistor and the first terminal of the OLED, and a second terminal of the second switch is coupled to the sensing circuit.

4. The apparatus as claimed in claim 3, wherein the switch circuit comprises:

a third switch, wherein a control terminal of the third switch is controlled by a correction signal, a first terminal of the third switch receives the test data, and a second terminal of the third switch is coupled to the first terminal of the first switch; and

a fourth switch, wherein a control terminal of the fourth switch is controlled by the correction signal, a first terminal of the fourth switch is coupled to the corresponding data line to receive the display data, and a second terminal of the fourth switch is coupled to the first terminal of the first switch;

wherein the third switch is turned on and the fourth switch is turned off in the test data period, and the third switch is turned off and the fourth switch is turned on in the display data period.

5. The apparatus as claimed in claim 3, wherein the control terminal of the first switch and the control terminal of the second switch are coupled to the corresponding scan line, wherein the first switch and the second switch are turned on in the test data period and the display data period.

6. The apparatus as claimed in claim 3, wherein the first switch and the second switch are turned on in the test data period, and the first switch is turned on and the second switch is turned off in the display data period.

7. The apparatus as claimed in claim 3, wherein the gate driving circuit comprises:

a plurality of shift registers series-connected to one another, wherein a plurality of output terminals of the shift registers are one-on-one coupled to the scan lines; and

a plurality of AND gates, wherein a plurality of first input terminals of the AND gates receive a correction signal, a plurality of second input terminals of the AND gates are one-to-one coupled to the output terminals of the shift registers, and an output terminal of a corresponding AND gate of the AND gates is coupled to a control terminal of the second switch of the corresponding pixel circuit.

8. The apparatus as claimed in claim 3, wherein the first switch and the second switch are turned on in a first sub-period of the test data period, the first switch is turned off and the second switch is turned on in a second sub-period of the test data period, and the first switch is turned on and the second switch is turned off in the display data period.

9. The apparatus as claimed in claim 3, wherein the gate driving circuit comprises:

a plurality of first shift registers series-connected to one another;

a plurality of first AND gates, wherein a plurality of first input terminals of the first AND gates receive a first correction signal, a plurality of second input terminals of the first AND gates are one-to-one coupled to a plurality of output terminals of the first shift registers, and a plurality of output terminals of the first AND gates are one-on-one coupled to the scan lines;

a plurality of second shift registers series-connected to one another; and

a plurality of second AND gates, wherein a plurality of first input terminals of the second AND gates receive a second correction signal, a plurality of second input terminals of the second AND gates are one-to-one coupled to a plurality of output terminals of the second shift registers, and an output terminal of a corresponding second AND gate of the second AND gates is coupled to a control terminal of the second switch of the corresponding pixel circuit.

10. A method for sensing a display panel, wherein the display panel comprises a plurality of scan lines, a plurality of data lines and a plurality of pixel circuits, a data input terminal and a gate terminal of a corresponding pixel circuit of the pixel circuits are coupled to a corresponding data line of the data lines and a corresponding scan line of the scan lines respectively, and the method comprising:

defining a plurality of scan-line periods in a frame period;

scanning the scan lines in the scan-line periods by a gate driving circuit, wherein a corresponding scan-line period within the scan-line periods corresponds to the corresponding scan line;

controlling the corresponding pixel circuit to receive test data and sensing an electrical characteristic of the corresponding pixel circuit in a test data period within the corresponding scan-line period; and

controlling the corresponding pixel circuit to receive display data from the corresponding data line without sensing the corresponding pixel circuit in a display data period within the same corresponding scan-line period.