Additional application of voltage during a write sequence

• US 9,183,799 B2
• Filed: 05/24/2011
• Issued: 11/10/2015
• Est. Priority Date: 05/24/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steven Porter, Yousefpor, Marduke, Bae, Hopil
• Primary Examiner(s): HOFFNER, LINH NGUYEN
• Application Number:
  US13/143,184
• Publication Number:
  US 20120299971A1
• Time in Patent Office: 1,631 Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2310/027 Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• 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 2320/0233 Improving the luminance or brightness uniformity across the screen
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3233 with pixel circuitry controlling the current through the light-emitting element
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3614 Control of polarity reversal in general
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3659 the addressing of the pixel involving the control of two or more scan electrodes or two or more data electrodes, e.g. pixel voltage dependant on signal of two data electrodes
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

With respect to liquid crystal display inversion schemes, a large change in voltage on a data line can affect the voltages on adjacent data lines due to capacitive coupling between data lines. The resulting change in voltage on these adjacent data lines can give rise to visual artifacts in the data lines'"'"' corresponding sub-pixels. Various embodiments of the present disclosure serve to prevent or reduce these visual artifacts by applying voltage to a data line more than once during the write sequence. Doing so can allow erroneous brightening or darkening caused by large voltage swings to be overwritten without causing additional large voltage swings on the data line.

Claims

1. A method of scanning a display during a first update, the method comprising:

applying a first voltage to a first sub-pixel;

applying a second voltage to a second sub-pixel;

applying a third voltage to a third sub-pixel, the third sub-pixel being adjacent to the first sub-pixel and second sub-pixel, wherein a magnitude of the third voltage is a target voltage reached by overdriving the third sub-pixel to an overdrive voltage and stopping the overdriving when the magnitude of the third voltage is approximately equal to a magnitude of the target voltage for the third sub-pixel, a magnitude of the overdrive voltage being greater than the magnitude of the target voltage for the third sub-pixel;

applying a fourth voltage to the first sub-pixel after the application of the third voltage, the fourth voltage having a same polarity as the first voltage; and

applying a fifth voltage to the second sub-pixel after the application of the third voltage, the fifth voltage having a same polarity as the second voltage.

2. The method of claim 1, wherein the fourth voltage is applied after the application of the fifth voltage.

3. The method of claim 1, wherein the third voltage is a target voltage for the third sub-pixel, the fourth voltage is a target voltage for the first sub-pixel, and the fifth voltage is a target voltage for the second sub-pixel.

4. The method of claim 1 further comprising:

applying a sixth voltage to the third sub-pixel after the application of the fourth voltage and the fifth voltage, the sixth voltage having an opposite polarity as the third voltage.

5. The method of claim 1, wherein the fifth voltage is applied after the application of the fourth voltage.

6. The method of claim 1, wherein the write sequence includes a first write sequence and a second write sequence, the first write sequence is a red-green-blue-green-red write sequence, and the second write sequence is a green-blue-red-green-blue write sequence.

7. The method of claim 1, wherein a magnitude of the first voltage includes one of zero volts, a mid-level gray voltage, a magnitude that is the same as a magnitude of the fourth voltage, and a magnitude that is greater than the magnitude of the fourth voltage.

8. The method of claim 1, the method further comprising performing the method of scanning for some of the rows but not all of the rows of the display panel.

9. A non-transitory computer-readable storage medium storing computer-readable program instructions executable to perform a method for scanning a display during a first update, the method comprising:

applying a first voltage to a first sub-pixel;

applying a second voltage to a second sub-pixel;

applying a third voltage to a third sub-pixel, the third sub-pixel being adjacent to the first sub-pixel and the second sub-pixel, wherein a magnitude of the third voltage is a target voltage reached by overdriving the third sub-pixel to an overdrive voltage and stopping the overdriving when the magnitude of the third voltage is approximately equal to a magnitude of the target voltage for the third sub-pixel, the magnitude of the overdrive voltage being greater than the magnitude of the target voltage for the third sub-pixel;

applying a fourth voltage to the first sub-pixel after the application of the third voltage, the fourth voltage having a same polarity as the first voltage; and

applying a fifth voltage to the second sub-pixel after the application of the fourth voltage, the fifth voltage having a same polarity as the second voltage.

10. The non-transitory computer-readable storage medium of claim 9, wherein the fourth voltage is applied after the application of the fifth voltage.

11. The non-transitory computer-readable storage medium of claim 9, wherein the third voltage is a target voltage for the third sub-pixel, the fourth voltage is a target voltage for the first sub-pixel, and the fifth voltage is a target voltage for the second sub-pixel.

12. The non-transitory computer-readable storage medium of claim 9, the method further comprising:

applying a sixth voltage to the third sub-pixel after the application of the fourth voltage and the fifth voltage, the sixth voltage having an opposite polarity as the third voltage.

13. The non-transitory computer-readable storage medium of claim 9, wherein a magnitude of the first voltage includes one of zero volts, a mid-level gray voltage, a magnitude that is the same as a magnitude of the fourth voltage, and a magnitude that is greater than the magnitude of the fourth voltage.

14. The non-transitory computer-readable storage medium of claim 9, the method further comprising performing the method of scanning for some of the rows but not all of the rows of the display panel.

15. A display apparatus comprising:

an array of display sub-pixels, each display sub-pixel associated with one of a plurality of scan lines and one of a plurality of data lines, a common electrode, and an individually addressable pixel electrode, the common electrode being electrically connected to a voltage source; and

a module connected to the array of pixels, the module configured to

electrically connect the plurality of data lines to the array of display sub-pixels and during a first update,

apply a first voltage to a first data line coupled to a first display sub-pixel,

apply a second voltage a second data line coupled to a second display sub-pixel,

apply a third voltage to a third data line coupled to a third display sub-pixel, the third sub-pixel being adjacent to the first sub-pixel and the second sub-pixel, wherein a magnitude of the third voltage is a target voltage reached by overdriving the third data line to an overdrive voltage and stopping the overdriving when the magnitude of the third voltage is approximately equal to a magnitude of the target voltage for the third data line, a magnitude of the overdrive voltage being greater than the magnitude of the target voltage for the third data line,

apply a fourth voltage to the first data line coupled to the first display sub-pixel after the application of the third voltage, the fourth voltage having a same polarity as the first voltage, and

apply a fifth voltage to the second data line coupled to the second display sub-pixel after the application of the third voltage, the fifth voltage having a same polarity as the second voltage.

16. The display apparatus of claim 15, wherein the fourth voltage is applied after the application of the fifth voltage.

17. The display apparatus of claim 15, wherein the third voltage is a target voltage for the third data line, the fourth voltage is a target voltage for the first data line, and the fifth voltage is a target voltage for the second data line.

18. The display apparatus of claim 15, the module further configured to

apply a sixth voltage to the third data line after the application of the fourth voltage, the sixth voltage having an opposite polarity as the third voltage.

19. The display apparatus of claim 15, wherein a magnitude of the first voltage includes one of zero volts, a mid-level gray voltage, a magnitude that is the same as the magnitude of the fourth voltage, and a magnitude that is greater than the magnitude of the fourth voltage.

20. The display apparatus of claim 15, the module further configured to perform the method of scanning for some of the rows but not all of the rows of the display panel.

21. The display apparatus of claim 15, wherein the module is disposed within a liquid crystal display driver module.

22. The display apparatus of claim 15, wherein the module is disposed within a host video driver.