Display device including touch screen compensation and touch sensing method thereof

Patent metadata

Field	Value
Publication number	US-9329725-B2
Application number	US-201514742414-A
Country	US
Kind code	B2
Filing date	Jun 17, 2015
Priority date	Dec 19, 2012
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A display device comprises a timing controller and a touch sensing unit. The timing controller drives a display panel such that a display mode for displaying an image in the display panel and a touch mode for sensing a user' s touch are alternately driven. The touch sensing unit differentially applies DTX (display touch crosstalk) compensation values by compensation area to sense the user' s touch in the touch mode, each of touch sensing block being a sensing unit for a user' s touch. Each compensation area is set based on a distance between a data driver and the compensation area. Each DTX compensation value is a value for compensating for an error of touch data caused by changes in respective grayscale values applied to pixels corresponding to a specific touch sensing block. The touch sensing blocks are divided in a column direction depending on arrangement of multiplexers in the data driver.

First claim

What is claimed is:

1. A display device, comprising:
a timing controller temporally dividing one frame period and driving a display panel such that a display mode for displaying an image in the display panel and a touch mode for sensing a user's touch are alternately driven;
a data driver receiving digital image data from the timing controller and outputting display data to data lines of the display panel; and
a touch sensing unit setting a plurality of compensation areas comprising at least one or more touch sensing blocks, and differentially applying DTX (display touch crosstalk) compensation values by compensation area to sense the user's touch in the touch mode, each of the touch sensing blocks being a sensing unit for a user's touch, wherein,
each of the compensation areas is set to a predetermined width in a row direction based on a distance between the data driver and the compensation area,
each of the DTX compensation values is a value for compensating for an error of touch data caused by changes in respective grayscale values applied to pixels corresponding to a specific touch sensing block, and
the touch sensing blocks are set to a predetermined width in a column direction based on the data line connections to a multiplexor comprised in the data driver.

2. The display device of claim 1 , wherein the touch sensing unit comprises a lookup table storage unit calculating, when maximum grayscale values are applied to a plurality of pixels corresponding to a specific touch sensing block, a lookup table obtained by measuring DTX amplitudes that are changes in touch data generated from the touch sensing block.

3. The display device of claim 1 , wherein the touch sensing unit comprises a compensation value calculating unit differentially setting the DTX compensation values in proportion to an average value of DTX amplitudes appearing in the touch sensing blocks.

4. The display device of claim 1 , wherein the touch sensing unit comprises a compensation value calculating unit multiplying an average value of DTX amplitudes, appearing in a specific touch sensing block comprised in the display panel, by a DTX weight based on a position of a corresponding compensation area to calculate a DTX compensation value for the compensation area.

5. The display device of claim 1 , wherein the touch sensing unit comprises a touch calculation unit subtracting a DTX compensation value from the user's touch data measured from a specific touch sensing block to compensate for the touch data, and comparing the touch data and a touch threshold value to calculate whether there is the user's touch.

6. A touch sensing method of a display device,
which temporally divides one frame period and drives a display panel such that a display mode for displaying an image in the display panel and a touch mode for sensing a user's touch are alternately driven, the touch sensing method comprising:
setting a plurality of compensation areas, comprising at least one or more touch sensing blocks, based on a distance separated from a data driver in the touch mode, each of the touch sensing blocks being a sensing unit for a user's touch; and
differentially applying DTX (display touch crosstalk) compensation values by compensation area to sense the user's touch,
wherein each of the DTX compensation values is a value for compensating for an error of touch data caused by changes in respective grayscale values applied to pixels corresponding to a specific touch sensing block, and
wherein the setting of a plurality of compensation areas comprises dividing the compensation areas in a row direction based on a distance from the data driver, and dividing the compensation areas in a column direction based on the data line connections to a multiplexer comprised in the data driver.

7. The touch sensing method of claim 6 , wherein the sensing of the user's touch comprises multiplying an average value of DTX amplitudes, appearing in the touch sensing blocks comprised in the display panel, by DTX weights based on positions of the compensation areas to calculate different DTX compensation values for the compensation areas.

Assignees

• Lg Display Co Ltd

Inventors

• Pyo Seung Eun
• Kim Sung Chul

Classifications

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title

• G06F3/044

  by capacitive means · CPC title

• G06F3/0418 Primary

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G3/3666

  with the matrix divided into sections · CPC title