COMPENSATION METHOD, DEVICE, CIRCUIT FOR DISPLAY PANEL, DISPLAY PANEL AND DISPLAY DEVICE

• US 20200388219A1
• Filed: 08/31/2018
• Published: 12/10/2020
• Est. Priority Date: 12/07/2017
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: MENG, Song, WU, Zhongyuan, SONG, Danna
• Granted Patent: US 11,011,114 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0295 by monitoring each display pixel
• 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 3/2007 Display of intermediate tones
• 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

Abstract

The present disclosure provides a compensation method, device, circuit for a display panel, a display panel and a display device. The display panel includes a plurality of pixel circuits, each of which comprises a driving transistor. The compensation method includes: obtaining a first compensation grayscale value GL₁ and a second compensation grayscale value GL₂ of a pixel circuit to be compensated; obtaining a first compensation luminance L₁, a first gate-source voltage V_gs1 of the driving transistor, a second compensation luminance L₂, and a second gate-source voltage V_gs2 of the driving transistor, wherein L₁ and V_gs1 correspond to GL₁, and L₂ and V_gs2 correspond to GL₂; obtaining a theoretical luminance L corresponding to an input grayscale value GL; calculating the compensation gate-source voltage V′_gs by using L, L₁, V_gs1, L₂, and V_gs2; and obtaining an output compensation grayscale value GL′ according to V′_gss.

Claims

1. A compensation method for a display panel, the display panel comprising a plurality of pixel circuits, each of the pixel circuits comprising a driving transistor, the compensation method comprising:

obtaining a first compensation grayscale value GL₁ and a second compensation grayscale value GL₂ of a pixel circuit to be compensated;

obtaining a first compensation luminance L₁, a first gate-source voltage V_gs1 of the driving transistor, a second compensation luminance L₂, and a second gate-source voltage V_gs2 of the driving transistor, which are of the pixel circuit to be compensated, wherein the first compensation luminance L₁ and the first gate-source voltage V_gs1 correspond to the first compensation grayscale value GL₁, and the second compensation luminance L₂ and the second gate-source voltage Vgs2 correspond to the second compensation grayscale value GL₂;

obtaining a theoretical luminance L corresponding to an input grayscale value GL;

calculating a compensation gate-source voltage V′

_gs according to the theoretical luminance L, the first compensation luminance L₁, the first gate-source voltage V_gs1, the second compensation luminance L₂, and the second gate-source voltage V_gs2; and

obtaining an output compensation grayscale value GL′

according to the compensation gate-source voltage V′

_gs.

2. The compensation method according to claim 1, wherein

3. The compensation method according to claim 2, wherein the first compensation luminance L₁ is a maximum luminance L_max, the second compensation luminance L₂ is

4. The compensation method according to claim 3, wherein the maximum luminance L_max is a normalized luminance value,

5. The compensation method according to claim 3, wherein the exponential parameter “

a”

is obtained by the following steps;

lighting up a region of the display panel such that the a luminance of the region reaches the maximum luminance L_max, and measuring a first gate-source voltage V^′

_gs1 of a driving transistor of a pixel circuit in the region corresponding to the maximum luminance L_max;

measuring a threshold voltage V_t of the driving transistor in the region;

calculating a second gate-source voltage V^′

_gs2 of the driving transistor in the region according to the first gate-source voltage V′

_gs1 and the threshold voltage V_t of the region, wherein

6. The compensation method according to claim 5, wherein the pixel circuit further comprises a first switching transistor, a second switching transistor, a light emitting diode, and a capacitor;

a gate electrode of the first switching transistor is electrically connected to a first gate line, a first electrode of the first switching transistor is electrically connected to a data line, a second electrode of the first switching transistor is electrically connected to a gate electrode of the driving transistor;

the gate electrode of the driving transistor is electrically connected to a first terminal of the capacitor, a drain electrode of the driving transistor is electrically connected to a power supply voltage terminal, a source electrode of the driving transistor is electrically connected to an anode terminal of the light emitting diode;

a second terminal of the capacitor is electrically connected to the anode terminal of the light emitting diode, and a cathode terminal of the light emitting diode is electrically connected to a ground terminal;

a gate electrode of the second switching transistor is electrically connected to a second gate line, and a first electrode of the second switching transistor is electrically connected to the source electrode of the driving transistor, and a second electrode of the second switching transistor is electrically connected to a sensing voltage line.

7. The compensation method according to claim 6, wherein the step of obtaining the first gate-source voltage V_gs1 of the driving transistor of the pixel circuit to be compensated comprises the following steps:

inputting a first gate-source voltage of the region into a pixel circuit in the region through a data line, and continuously charging a sensing voltage line electrically connected to the pixel circuit in the region for a first predetermined time to obtain a first target voltage V_target1;

in a field blanking stage, inputting a first input voltage to a data line electrically connected to the pixel circuit to be compensated, continuously charging a sensing voltage line electrically connected to the pixel circuit to be compensated for the first predetermined time, and measuring a charge voltage of the sensing voltage line;

adjusting the first input voltage based on a determination that the measured charge voltage is not equal to the first target voltage V_target1, continuously recharging the sensing voltage line electrically connected to the pixel circuit to be compensated for the first predetermined time and measuring the charge voltage in a next field blanking stage;

repeating the adjusting, charging and measuring until the measured charge voltage is equal to the first target voltage V_target1; and

obtaining the first gate-source voltage of the pixel circuit to be compensated according to a corresponding first input voltage input to the data line based on a determination that the measured charge voltage is equal to the first target voltage V_target1.

8. The compensation method according to claim 6, wherein the step of obtaining the second gate-source voltage V_gs2of the driving transistor of the pixel circuit to be compensated comprises the following steps:

inputting a second gate-source voltage of the region into a pixel circuit in the region through a data line, and continuously charging a sensing voltage line electrically connected to the pixel circuit in the region for a second predetermined time to obtain a second target voltage V_target2;

in a field blanking stage, inputting a second input voltage to a data line electrically connected to the pixel circuit to be compensated, continuously charging a sensing voltage line electrically connected to the pixel circuit to be compensated for the second predetermined time, and measuring a charge voltage of the sensing voltage line;

adjusting the second input voltage based on a determination that the measured charge voltage is not equal to the second target voltage V_target2, continuously recharging the sensing voltage line electrically connected to the pixel circuit to be compensated for the second predetermined time and measuring the charge voltage in a next field blanking stage;

repeating the adjusting, charging and measuring until the measured charge voltage is equal to the second target voltage V_target2; and

obtaining the second gate-source voltage of the pixel circuit to be compensated according to a corresponding second input voltage input to the data line based on a determination that the measured charge voltage is equal to the second target voltage V_target2.

9. The compensation method according to claim 7, wherein, the step of continuously charging the sensing voltage line for the first predetermined time comprises the following steps:

turning on the first switching transistor and the second switching transistor, and inputting the first input voltage to the data line, with the first input voltage being stored at the first terminal of the capacitor and the driving transistor being turned on by the first input voltage stored at the first terminal; and

turning off the first switching transistor and turning on the second switching transistor, so that the sensing voltage line is charged for the first predetermined time by the power supply voltage terminal through the driving transistor and the second switching transistor;

wherein, based on a determination that the measured charge voltage is equal to the first target voltage V_target1, the corresponding first input voltage input to the data line is the first gate-source voltage of the pixel circuit to be compensated.

10. The compensation method according to claim 7, wherein, the step of continuously charging the sensing voltage line for the first predetermined time comprises the following steps:

turning on the first switching transistor and the second switching transistor, and inputting the first input voltage to the data line to turn on the driving transistor, so that the sensing voltage line is charged for the first predetermined time by the power supply voltage terminal through the driving transistor and the second switching transistor;

wherein, based on a determination that the measured charge voltage is equal to the first target voltage V_target1, a difference between the corresponding first input voltage input to the data line and the measured charge voltage is the first gate-source voltage of the pixel circuit to be compensated.

11. The compensation method according to claim 8, wherein, the step of continuously charging the sensing voltage line for the second predetermined time comprises the following steps:

turning on the first switching transistor and the second switching transistor, and inputting the second input voltage to the data line, with the second input voltage being stored at the first terminal of the capacitor and the driving transistor being turned on by the second input voltage stored at the first terminal; and

turning off the first switching transistor and turning on the second switching transistor, so that the sensing voltage line is charged for the second predetermined time by the power supply voltage terminal through the driving transistor and the second switching transistor;

wherein, based on a determination that the measured charge voltage is equal to the second target voltage V_target2, the corresponding second input voltage input to the data line is the second gate-source voltage of the pixel circuit to be compensated.

12. The compensation method according to claim 8, wherein, the step of continuously charging the sensing voltage line for the second predetermined time comprises the following steps:

turning on the first switching transistor and the second switching transistor, and inputting the second input voltage to the data line to turn on the driving transistor, so that the sensing voltage line is charged for the second predetermined time by the power supply voltage terminal through the driving transistor and the second switching transistor;

wherein, based on a determination that the measured charge voltage is equal to the second target voltage V_target2, a difference between the corresponding second input voltage input to the data line and the measured charge voltage is the second gate-source voltage of the pixel circuit to be compensated.

13. The compensation method according to claim 1, wherein the step of obtaining the theoretical luminance L corresponding to the input grayscale value GL comprises:

obtaining a corresponding theoretical luminance L according to the input grayscale value GL and a curve of a luminance versus a grayscale value.

14. The compensation method according to claim 1, wherein the step of obtaining the output compensation grayscale value GL′

according to the compensation gate-source voltage V′

_gs comprises the following steps;

obtaining a compensation gate voltage V′

_g according to the compensation gate-source voltage V′

_gs; and

obtaining the output compensation grayscale value GL′

according to the compensation gate voltage V′

_g and a correspondence relationship between a grayscale value and a gate voltage.

15. A compensation device for a display panel, comprising:

a memory; and

a processor coupled to the memory, the processor configured to execute the method according to claim 1 based on instructions stored in the memory.

16. A circuit for a display panel, comprising:

a compensation device configured to receive an input grayscale value GL, and obtain an output compensation grayscale value GL′

according to the compensation method of claim 1;

a conversion circuit configured to convert the output compensation grayscale value GL′

to a compensation data voltage V_data according to a correspondence relationship between a grayscale value and a voltage after receiving the output compensation grayscale value GL′

from the compensation device; and

a pixel circuit configured to emit light according to the compensation data voltage V_data.

17. A display panel, comprising:

the circuit for the display panel according to claim 16.

18. A display device, comprising:

the display panel according to claim 17.

19. A computer-readable storage medium on which computer program instructions are stored, wherein the computer program instructions when executed by a processor implement the steps of the method according to claim 1.