# US 2017/0287418 A1 · Method of driving a display panel and a display apparatus for performing the same

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- Number: US 2017/0287418 A1
- Document ID: US20170287418A1
- Status: Published application
- Kind: A1
- Application number: 15/403,584
- Filed: 2017-01-11
- Published: 2017-10-05
- Earliest claimed: 2016-04-04
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: HYUN SIK HWANG; Daecheol Kim; Yoongu Kim; Bongim Park; Ik Hyun Ahn; Woojoo Lee; Tae-Jong Jun
- Web page: https://patentgrep.com/patent/US20170287418A1

## CPC

- 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)}
- G09G 3/20: for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters}
- G09G 3/3614: {Control of polarity reversal in general}
- G09G 3/3648: {using an active matrix (G09G3/367 - G09G3/3696 take precedence)}
- G09G 5/06: using colour palettes, e.g. look-up tables
- G09G 2300/0426: Layout of electrodes and connections
- G09G 2310/068: Application of pulses of alternating polarity prior to the drive pulse in electrophoretic displays
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/0252: Improving the response speed
- G09G 2320/0285: using tables for spatial correction of display data
- G09G 2340/16: Determination of a pixel data signal depending on the signal applied in the previous frame
- G09G 2360/18: Use of a frame buffer in a display terminal, inclusive of the display panel
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

A method of driving a display panel includes determining a present polarity of a pixel data signal of a present frame, generating a first compensated grayscale of the pixel data signal of the present frame using a pixel data signal of a previous frame, the pixel data signal of the present frame, and the present polarity, and displaying an image using the first compensated grayscale. The first compensated grayscale varies according to the present polarity.

## Claims

### Claim 1

A method of driving a display panel, the method comprising:
determining a present polarity of a pixel data signal of a present frame;
generating a first compensated grayscale of the pixel data signal of the present frame using a pixel data signal of a previous frame, the pixel data signal of the present frame, and the present polarity, wherein the first compensated grayscale varies according to the present polarity; and
displaying an image using the first compensated grayscale.

### Claim 2 (depends on 1)

The method of claim 1, wherein a compensated grayscale for a negative subpixel when the present polarity is negative is less than a compensated grayscale for a positive subpixel when the present polarity is positive.

### Claim 3 (depends on 2)

The method of claim 2, wherein the first compensated grayscale is generated using a first lookup table storing the compensated grayscale for the negative subpixel and a second lookup table storing the compensated grayscale for the positive subpixel.

### Claim 4 (depends on 1)

The method of claim 1, wherein the present polarity is determined using a pixel map that represents a structure of pixel data of the present frame, a line count and a pixel count that represent a location in the pixel map, and a polarity signal that represents polarities of all the pixel data of the present frame.

### Claim 5 (depends on 1)

The method of claim 1, further comprising determining a previous polarity of the pixel data signal of the previous frame,
wherein the first compensated grayscale is further generated using the previous polarity, and
the first compensated grayscale varies according to the previous polarity and the present polarity.

### Claim 6 (depends on 5)

The method of claim 5, wherein the previous polarity is determined using a pixel map that represents a structure of pixel data of the present frame, a line count and a pixel count that represent a location in the pixel map, a polarity signal that represents polarities of all the pixel data of the present frame, and an inverting mode signal that represents an inverting mode of all the pixel data of the present frame.

### Claim 7 (depends on 5)

The method of claim 5, wherein a compensated grayscale for a negative subpixel when the present polarity is negative is less than a compensated grayscale for a positive subpixel when the present polarity is positive.

### Claim 8 (depends on 7)

The method of claim 7, wherein
a negative to negative compensated grayscale is generated when the previous polarity is negative and the present polarity is negative,
a positive to negative compensated grayscale is generated when the previous polarity is positive and the present polarity is negative, and
the negative to negative compensated grayscale is less than the positive to negative compensated grayscale.

### Claim 9 (depends on 8)

The method of claim 8, wherein
a negative to positive compensated grayscale is generated when the previous polarity is negative and the present polarity is positive,
a positive to positive compensated grayscale is generated when the previous polarity is positive and the present polarity is positive, and
the negative to positive compensated grayscale is greater than the positive to positive compensated grayscale.

### Claim 10 (depends on 9)

The method of claim 9, wherein the first compensated grayscale is generated using a first lookup table storing the negative to negative compensated grayscale, a second lookup table storing the positive to negative compensated grayscale, a third lookup table storing the negative to positive compensated grayscale, and a fourth lookup table storing the positive to positive compensated grayscale.

### Claim 11 (depends on 1)

The method of claim 1, further comprising:
merging the present polarity with the pixel data signal of the present frame to generate a merged signal of the present frame; and
extracting the present polarity from the merged signal of the present frame.

### Claim 12

A display apparatus comprising:
a pixel polarity determining part configured to determine a present polarity of a pixel data signal of a present frame;
a grayscale compensating part configured to generate a first compensated grayscale of the pixel data signal of the present frame by using a pixel data signal of a previous frame, the pixel data signal of the present frame, and the present polarity, wherein the first compensated grayscale varies according to the present polarity; and
a display panel configured to display an image using the first compensated grayscale.

### Claim 13 (depends on 12)

The display apparatus of claim 12, further comprising:
a data buffer configure to buffer the pixel data signal of the present frame and to output the pixel data signal of the present frame; and
a memory configured to delay the pixel data signal of the present frame to generate the pixel data signal of the previous frame and to output the pixel data signal of the previous frame to the grayscale compensating part.

### Claim 14 (depends on 12)

The display apparatus of claim 12, wherein
the grayscale compensating part is configured to generate a compensated grayscale for a negative subpixel when the present polarity is negative and a compensated grayscale for a positive subpixel when the present polarity is positive, and
the compensated grayscale for the negative subpixel is less than the compensated grayscale for the positive subpixel.

### Claim 15 (depends on 14)

The display apparatus of claim 14, wherein the grayscale compensating part comprises:
a first lookup table storing the compensated grayscale for the negative subpixel; and
a second lookup table storing the compensated grayscale for the positive subpixel.

### Claim 16 (depends on 12)

The display apparatus of claim 12, wherein the pixel polarity determining part is configured to determine the present polarity using a pixel map that represents a structure of pixel data of the present frame, a line count and a pixel count that represent a location in the pixel map, and a polarity signal that represents polarities of all the pixel data of the present frame.

### Claim 17 (depends on 12)

The display apparatus of claim 12, wherein the pixel polarity determining part is configured to determine a previous polarity of the pixel data signal of the previous frame,
the grayscale compensating part is further configured to generate the first compensated grayscale using the previous polarity, and
the first compensated grayscale varies according to the previous polarity and the present polarity.

### Claim 18 (depends on 17)

The display apparatus of claim 17, wherein
the grayscale compensating part is configured to generate a compensated grayscale for a negative subpixel when the present polarity is negative and a compensated grayscale for a positive subpixel when the present polarity is positive,
the compensated grayscale for the negative subpixel is less than the compensated grayscale for the positive subpixel,
the grayscale compensating part is configured to generate a negative to negative compensated grayscale when the previous polarity is negative and the present polarity is negative and a positive to negative compensated grayscale when the previous polarity is positive and the present polarity is negative,
the negative to negative compensated grayscale is less than the positive to negative compensated grayscale,
the grayscale compensating part is configured to generate a negative to positive compensated grayscale when the previous polarity is negative and the present polarity is positive and a positive to positive compensated grayscale when the previous polarity is positive and the present polarity is positive, and
the negative to positive compensated grayscale is greater than the positive to positive compensated grayscale.

### Claim 19 (depends on 12)

The display apparatus of claim 12, wherein
the pixel polarity determining part is configured to output the present polarity to a data buffer,
the data buffer is configured to merge the present polarity with the pixel data signal of the present frame to generate a merged signal of the present frame; and
the grayscale compensating part is configured to extract the present polarity from the merged signal of the present frame.

### Claim 20

A method of driving a display panel, the method comprising:
determining a present polarity of a pixel data signal of a present frame;
merging the present polarity with the pixel data signal of the present frame to generate a first merged signal of the present frame;
delaying the first merged signal to generate a second merged signal of a previous frame;
extracting the present polarity from the first merged signal;
extracting a previous polarity of a pixel data signal of the previous frame from the second merged signal; and
generating a compensated grayscale using the pixel data signal of the previous frame, the pixel data signal of the present frame, the previous polarity, and the present polarity,
wherein the compensated grayscale varies according to the previous polarity and the present polarity.