PRE-COMPENSATION FOR PRE-TOGGLING-INDUCED ARTIFACTS IN ELECTRONIC DISPLAYS

• US 20190325816A1
• Filed: 04/03/2019
• Published: 10/24/2019
• Est. Priority Date: 04/18/2018
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Lin, Hung Sheng, Gao, Shengkui, Tang, Yingying, Chang, Sean C., Vahid Far, Mohammad B., Omid-Zohoor, Kasra M., Zhao, Chumin, Huang, Jingyu, Jangda, Mohammad Ali, Nho, Hyunwoo, Wang, Chaohao, DeVincentis, Marc J., Albrecht, Marc, Rieutort-Louis, Warren S.
• Granted Patent: US 10,665,157 B2
• Time in Patent Office: Days
• CPC Class Codes: G09G 2300/0819 used for counteracting undesired variations, e.g. feedback or autozeroing
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 2300/0861 with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
• CPC Class Codes: G09G 2310/0251 Precharge or discharge of pixel before applying new pixel voltage
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0257 Reduction of after-image effects
• CPC Class Codes: G09G 2320/045 Compensation of drifts in the characteristics of light emitting or modulating elements
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/2051 with use of a spatial dither pattern
• CPC Class Codes: G09G 3/2055 the pattern being varied in time
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3275 Details of drivers for data electrodes

Abstract

Systems and methods reduce likelihood of hysteresis that reduces perceived image quality of a subsequent image frame by toggling the display pixels to relax the display pixels by overwriting previous image frame data. During non-emission periods of the pixels, the pixels may be pre-toggled or exercised to improve response time and accuracy of the pixel. Data for pixels being programmed may also be used to pre-toggle other pixels reducing overhead but increasing cross-talk. Since the amount of cross-talk is related to content of the pixels being pre-toggled, a line buffer may be used to store image data for the pixels being pre-toggled. This stored image data may be used to determine how much pre-compensation is to be applied to data for the pixels being programmed. In other words, an amount of compensation applied is based at least in part on the content (e.g., greyscale levels) of the image data.

Claims

1. An electronic display, comprising:

a display panel comprising a plurality of rows of pixels; and

pre-toggling circuitry configured to use image data corresponding to a row of pixels of the plurality of rows of pixels to toggle switching circuitry of other rows of pixels of the plurality between emission periods of the other rows of pixels, wherein the pre-toggling circuitry comprises pre-toggling compensation circuitry configured to pre-compensate the image data for predicted cross-talk in the image data between the plurality of rows of pixels due to supplying the image data to each of the plurality of rows of pixels, and the pre-compensation is performed before application of the image data to pre-toggle the other rows of pixels and application of the image data to program the row of pixels.

2. The electronic display of claim 1, wherein the pre-toggling compensation circuitry is configured to pre-compensate the image data based at least in part on content of the other rows of pixels.

3. The electronic display of claim 2, wherein the pre-toggling compensation circuitry comprises a line buffer configured to store previous image data from the other rows of pixels that were programmed prior to programming the row of pixels.

4. The electronic display of claim 3, wherein the pre-toggling compensation circuitry is configured to store the image data in the line buffer for use in determining pre-toggling compensation for subsequent rows of pixels programmed after the row of pixels, wherein the image data is stored in the line buffer before the pre-compensation of the image data is performed.

5. The electronic display of claim 1, wherein the pre-toggling compensation circuitry is configured to apply the pre-compensated image data to the row of pixels and the other rows of pixels at the same time.

6. The electronic display of claim 1, wherein the pre-toggling compensation circuitry comprises a look-up table (LUT) used to apply the pre-compensation of the image data to the image data.

7. The electronic display of claim 6, wherein the LUT is used to determine a compensation level for the pre-compensation of the image data based at least in part on contents of the other rows of pixels.

8. The electronic display of claim 7, wherein the compensation level is based at least in part on a digital brightness value (DBV) that corresponds to a global brightness setting for the display panel.

9. The electronic display of claim 1, wherein the pre-toggling compensation circuitry comprises a model used to determine a compensation level for the pre-compensation of the image data based at least in part on contents of the other rows of pixels.

10. The electronic display of claim 9, wherein the model is used to determine a compensation level for the pre-compensation of the image data based at least in part on contents of the other rows of pixels.

11. A method comprising:

receiving image data at pre-toggle compensation circuitry that pre-compensates the image data for cross-talk between a plurality of rows of pixels of an electronic display, wherein the image data indicates greyscale levels for the plurality of rows of pixels;

storing the image data in a line buffer;

pre-compensating, using at least a portion of the stored image data, a programming portion of the image data as pre-compensated data to compensate for the cross-talk between the plurality of rows of pixels of the electronic display when pre-toggling a first subset of the plurality of rows of pixels corresponding to the at least a portion of the stored image data;

programming a second subset of the plurality of rows of pixels using the pre-compensated data; and

pre-toggling the first subset of the plurality of rows of pixels using the pre-compensated data, wherein pre-toggling each row of the first subset of the plurality of rows of pixels occurs between emission periods of the respective row.

12. The method of claim 11 comprising generating a compensation level based at least in part on greyscale levels of the at least a portion of the stored image data, wherein pre-compensating the programming portion of the image data as pre-compensated data comprises combining the compensation level with the programming portion as the pre-compensated data.

13. The method of claim 12, wherein generating the compensation level is based at least in part on a look-up table or model.

14. The method of claim 12, wherein generating the compensation level is based at least in part on a digital brightness value (DBV) that corresponds to a global brightness level for the electronic display.

15. The method of claim 11 comprising:

scaling the programming portion before pre-compensating the programming portion; and

de-scaling the pre-compensated data.

16. The method of claim 11 comprising dithering greyscale levels of one or more pixels in the pre-compensated data to enable increases luminance precision by averaging luminance values to provide fractional levels of the greyscale levels.

17. The method of claim 16, wherein dithering the greyscale levels comprises spatial dithering averaging pixels of the one or more pixels.

18. The method of claim 16, wherein dithering the greyscale levels comprises temporal dithering averaging greyscale levels over time.

19. An electronic device comprising:

an input configured to receive image data for a plurality of pixels of a display of the electronic device;

a line buffer configured to store the image data;

brightness adaption circuitry configured to pre-compensate a to-be-programmed portion of the image data using previously programmed portions of the image data stored in the line buffer, wherein the pre-compensation is configured to compensate for cross-talk between the plurality of pixels induced by pre-toggling a first subset of the plurality of pixels corresponding to the previously programmed portions of the image data while driving a second subset of the plurality of pixels; and

an output configured to;

output the pre-compensated to-be programmed portion to the first subset of the plurality of pixels to pre-toggle the first subset of the plurality of pixels; and

output the pre-compensated to-be programmed portion to the second subset of the plurality of pixels to program the second subset of the plurality of pixels.

20. The electronic device of claim 19, wherein the brightness adaption circuitry is configured to select alternating rows in the line buffer as the previously programmed portions of the image data.

21. The electronic device of claim 20, wherein the brightness adaption circuitry comprises a lookup table or a model to generate a compensation level to be combined with the to-be-programmed portion to create a pre-compensated programming portion based at least in part on greyscale levels of the previously programmed portions of the image data.

22. A method comprising:

receiving first image data for a row of pixels of an electronic display;

fetching second image data for previously programmed rows of pixels of the electronic display;

pre-compensating the first image data for predicted cross-talk between the row of pixels and the previously programmed rows of pixels when applying the first image data to program the row of pixels and to pre-toggle the previously programmed rows of pixels, wherein pre-compensating the first image data is based at least in part on the second image data;

programming the row of pixels using the pre-compensated first image data; and

pre-toggling the previously programmed rows of pixels using the pre-compensated first image data.

23. The method of claim 22, wherein the pre-compensated first image data is applied to the row of pixels and the previously programmed rows of pixels at the same time.

24. The method of claim 22, wherein pre-compensating the first image data comprises predicting the cross-talk based at least in part on greyscale levels in the second image data.

25. The method of claim 24, wherein pre-compensating the first image data comprises predicting the cross-talk based at least in part on a digital brightness value (DBV) that corresponds to a global brightness level for the electronic display.