Image data correction for VCOM error

Patent metadata

Field	Value
Publication number	US-9472158-B2
Application number	US-201514660355-A
Country	US
Kind code	B2
Filing date	Mar 17, 2015
Priority date	Mar 17, 2015
Publication date	Oct 18, 2016
Grant date	Oct 18, 2016

Abstract

Systems and methods are provided for adjusting and displaying image data to account for variable common voltage error across separate common electrode sub-plates. The image data may be adjusted based on a common mode common voltage error on a common voltage line coupled to more than one different common electrode sub-plate. Each common electrode sub-plate may carry a common voltage that varies depending on values of the image data programmed to pixels associated with that common electrode sub-plate.

First claim

What is claimed is:

1. An electronic display comprising:
a first common electrode sub-plate associated with a first group of pixels;
a second common electrode sub-plate associated with a second group of pixels, wherein the second common electrode sub-plate is at least partially separate from the first common electrode sub-plate; and
driver circuitry configured to:
provide a target common voltage to a common voltage line to the first common electrode sub-plate and the second common electrode sub-plate;
sense a common mode common voltage on the common voltage line, wherein the common mode common voltage differs from the target common voltage based at least partly on electrical characteristics of the first common electrode sub-plate and the second common electrode sub-plate;
receive first image data signals for a first row of the first group of pixels and the second group of pixels;
adjust the first image data signals based at least in part on the common mode common voltage and a total data voltage difference between a sum of all of the first image data signals and a sum of second image data signals previously programmed into a second row of the first group of pixels and the second group of pixels; and
program the adjusted first image data signals into the first row of pixels of the first group of pixels and the second group of pixels.

2. The electronic display of claim 1 , wherein the driver circuitry is configured to determine an actual first common voltage on the first common electrode sub-plate and determine an actual second common voltage on the second common electrode sub-plate based at least in part on the common mode common voltage, and wherein the first image data signals are adjusted the first image data signals based at least in part on the actual first common voltage and the actual second common voltage.

3. The electronic display of claim 1 , wherein the second row of the first group of pixels and the second group of pixels is immediately adjacent to the first row of the first group of pixels and the second group of pixels.

4. The electronic display of claim 1 , wherein the driver circuitry is configured to determine an error coefficient based on the common mode common voltage and the total data voltage difference, wherein the first image data signals are adjusted based at least in part on the error coefficient.

5. The electronic display of claim 4 , wherein the driver circuitry is configured to determine the error coefficient as a proportional constant relating the total data voltage difference to the common mode common voltage.

6. The electronic display of claim 4 , wherein the driver circuitry is configured to determine the error coefficient according to the following relationship:
V ERROR _ VCOM =K*ΔV,
where V ERROR _ VCOM represents the common mode common voltage, ΔV represents the total data voltage difference, and K represents the error coefficient.

7. The electronic display of claim 4 , wherein the driver circuitry is configured to determine an actual first common voltage on the first common electrode sub-plate based on the error coefficient and a sum of a difference between a first portion of the first image data signals that correspond to pixels associated with the first common electrode sub-plate and a corresponding first portion of the second image data signals, wherein the current first portion of the first image data signals is adjusted based at least in part on the actual first common voltage.

8. The electronic display of claim 7 , wherein the driver circuitry is configured to determine the actual first common voltage on the first common electrode sub-plate according to the following relationship:
Actual V COM (common electrode sub-plate)= K*ΣD v
where Actual V COM (common electrode sub-plate) represents the actual first common voltage on the first common electrode sub-plate, ΣD v represents the sum of the difference between a first portion of the first image data signals that correspond to pixels associated with the first common electrode sub-plate and a corresponding first portion of the second image data signals, and K represents the error coefficient.

9. A method comprising:
supplying a target common voltage to a common voltage line coupled to a first common electrode sub-plate of an electronic display and a second common electrode sub-plate of the display, wherein the second common electrode sub-plate is at least partially separate from the first common electrode sub-plate;
sensing a common mode common voltage error on the common voltage line with regard to the target common voltage as first image data signals are being supplied to a first row of pixels, wherein a first group of pixels of the first row of pixels pertains to the first common electrode sub-plate and a second group of pixels of the first row of pixels pertains to the second common electrode sub-plate;
determining a total data voltage difference between a sum of all of the first image data signals and a sum of second image data signals previously programmed into a second row adjacent to the first row of pixels; and
adjusting the first image data signals based at least in part on the total data voltage difference and the common mode common voltage error.

10. The method of claim 9 , wherein supplying the target common voltage to the common voltage line comprises providing a static voltage that is not increased or decreased based on feedback.

11. The method of claim 9 , comprising:
determining an error coefficient that relates the total data voltage difference to the common mode common voltage; and
using the error coefficient to determine an actual first common voltage on the first common electrode sub-plate and an actual second common voltage on the second common electrode sub-plate;
wherein the first image data signals are adjusted to account for the actual first common voltage and the actual second common voltage.

12. The method of claim 11 , comprising determining a first portion of the total data voltage difference corresponding to pixels associated with the first common electrode sub-plate, wherein using the error coefficient to determine the actual first common voltage comprises multiplying the first portion by the error coefficient.

13. An electronic device comprising:
a processor configured to determine image data; and
an electronic display configured to display the image data after adjusting the image data based on a total data voltage difference and a common mode common voltage error on a common voltage line coupled to a plurality of different common electrode sub-plates, each common electrode sub-plate carrying a common voltage that varies depending on the common mode common voltage error and values of the image data programmed to pixels associated with that common electrode sub-plate;
wherein the total data voltage difference comprises a difference between a sum of first image data signals at a first time and a sum of second image data signals at a second time prior to the first time;
wherein the common mode common voltage error comprises a difference between a target voltage and a detected voltage on the common voltage line.

14. The electronic device of claim 13 , wherein the electronic display is configured to display the image data after adjusting the image data without varying a target voltage attempted to be supplied to the common voltage line coupled to the different common electrode sub-plates.

15. The electronic device of claim 13 , wherein the electronic display is configured to display the image data after adjusting the image data without providing any f

Assignees

• Apple Inc

Inventors

• Lin Hung Sheng
• Wang Chaohao
• Lee Szu-Hsien
• Yao Weijun
• Li Yingxuan
• Choi Wonjae

Classifications

• G09G2330/08

  Fault-tolerant or redundant circuits, or circuits in which repair of defects is prepared · CPC title

• G09G2310/0289

  Details of voltage level shifters arranged for use in a driving circuit · CPC title

• G09G3/3648

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title

• G09G2320/029

  by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel · CPC title

• G09G2330/06

  Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation · CPC title