Display device and touch sensing method thereof

• US 9,275,611 B2
• Filed: 12/23/2013
• Issued: 03/01/2016
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, Sung Chul
• Primary Examiner(s): Siddiqui, Md Saiful A
• Application Number:
  US14/139,279
• Publication Number:
  US 20140240246A1
• Time in Patent Office: 799 Days
• Field of Search: 345/102, 345173-179, 349 65- 68, 362/97.1, 362/155, 362/611
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 5/18 Timing circuits for raster scan displays specially adapted for television H04N ; synchronisation between the display unit and other display units, videodisc player G09G5/12

Abstract

Disclosed is a display device capable of improving touch sensitivity by removing noise from a user'"'"'s touch signal through compensation of display touch crosstalk, and a touch sensing method thereof, wherein the display device may include a timing controller for driving one frame by a time division method to alternately perform a displaying driving mode and a touch sensing mode; and a touch sensor for determining a DTX compensation block including at least one touch sensing block corresponding to a unit for sensing a user'"'"'s touch; calculating a compensation representative value and a sensing block average value; and sensing a user'"'"'s touch by compensating for touch data in accordance with a difference between the compensation representative value and the sensing block average value.

Claims

1. A display device comprising:

a timing controller for driving one frame by a time division method so as to alternately perform a displaying driving mode for displaying an image on a display panel and a touch sensing mode for sensing a user'"'"'s touch; and

a touch sensor for determining a display touch crosstalk (DTX) compensation block including at least one touch sensing block corresponding to a unit for sensing the user'"'"'s touch, calculating a compensation representative value which is a DTX value corresponding to a first average of grayscale values applied to a plurality of pixels overlapped with the DTX compensation block,

calculating a sensing block average value which is the DTX value corresponding to a second average of grayscale values applied to a plurality of pixels overlapped with the touch sensing block,

calculating a DTX compensation value which is a difference between the compensation representative value and the sensing block average value, compensating a user'"'"'s touch raw data measured in the touch sensing block by adding the DTX compensation value to the user'"'"'s touch raw data, and sensing the user'"'"'s touch using the compensated user'"'"'s touch raw data;

wherein the touch sensor includes a compensation block determining part which determines the DTX compensation block so as to make one DTX compensation block include the touch sensing block selected by input of a same multiplexer in accordance with a predetermined order.

2. The display device of claim 1, wherein the touch sensor divides the display panel into at least one DTX compensation block, and compensates for the touch data with reference to the compensation representative value generated by each DTX compensation block.

3. The display device of claim 1, wherein the touch sensor includes a representative value calculating part which calculates the first average of the grayscale values received from a data driver and applied to the plurality of pixels included in a region overlapped with the DTX compensation block, and calculates the compensation representative value.

4. The display device of claim 1, wherein the touch sensor includes a Look-up Table storing part which calculates a Look-up Table by measuring a maximum DTX value obtained in the touch sensing block when a maximum grayscale value is applied to the plurality of pixels included in the touch sensing block.

5. The display device of claim 1, wherein the touch sensor includes a compensation value calculating part which calculates the DTX compensation value by subtracting the compensation representative value from the sensing block average value.

6. The display device of claim 1, wherein the touch sensor includes a touch sensing part which adds the DTX compensation value to the user'"'"'s touch raw data measured in the touch sensing block so as to compensate for the user'"'"'s touch raw data, and calculates whether or not there is the user'"'"'s touch by comparing the compensated user'"'"'s touch raw data with a touch threshold.

7. A touch sensing method of a display device for driving one frame by a time division method so as to alternately perform a displaying driving mode for displaying an image on a display panel and a touch sensing mode for sensing a user'"'"'s touch, comprising:

determining a display touch crosstalk (DTX) compensation block including at least one touch sensing block corresponding to a unit for sensing the user'"'"'s touch;

in the touch sensing mode, calculating a compensation representative value which is a DTX value corresponding to a first average of grayscale values applied to a plurality of pixels overlapped with the DTX compensation block, and calculating a sensing block average value which is a DTX value corresponding to a second average of grayscale values applied to a plurality of pixels overlapped with the touch sensing block;

in the touch sensing mode, calculating a DTX compensation value in accordance with a difference between the compensation representative value and the sensing block average value;

in the touch sensing mode, compensating a user'"'"'s touch raw data measured in the touch sensing block by adding the DTX compensation value to the user'"'"'s touch raw data;

calculating whether or not there is the user'"'"'s touch by comparing the compensated user'"'"'s touch raw data, with a touch threshold; and

calculating a Look-up Table by measuring a maximum DTX value obtained in the touch sensing block when a maximum grayscale value is applied to the plurality of pixels included in the touch sensing block.