Display device and data driving circuit thereof

Patent metadata

Field	Value
Publication number	US-9245490-B1
Application number	US-201514733643-A
Country	US
Kind code	B1
Filing date	Jun 8, 2015
Priority date	Dec 24, 2014
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

A touch display device includes a timing controller to generate a sync signal for controlling timing of a touch sensor driving period and a display driving period, where the display driving period comprises a first phase to drive odd signal lines according to a first polarity and to drive even signal lines according to a second polarity, a second phase to drive the odd signal lines according to the second polarity and to drive the even signal lines according to the first polarity, and a charge share period between the first phase and the second phase. A set of charge sharing switches couple the odd and even signal lines together during the charge share period and couple the odd and even signal lines together during the touch sensor driving period.

First claim

What is claimed is:

1. A touch display device, comprising:
a timing controller to generate a sync signal for controlling timing of a touch sensor driving period and a display driving period in each of a plurality of frames, the touch sensor driving period and the display driving period alternating with each other;
a display panel comprising a plurality of display pixels having a common electrode segmented into a plurality of touch sensors, the plurality of display pixels to display pixel data in response to data voltages during the display driving period;
a touch sensor driving circuit to supply a touch sensor driving signal to the plurality of touch sensors during the touch sensor driving period and to detect if a touch occurred based on a change in charge on the touch sensors;
a plurality of positive polarity output buffers to output positive polarity data voltages to the display pixels during the display driving period;
a plurality of negative polarity output buffers to output negative polarity data voltages to the display pixels during the display driving period;
a first set of switches to couple the plurality of positive polarity output buffers to respective odd signal lines and to couple the plurality of negative polarity output buffers to respective even signal lines during a first phase of the display driving period;
a second set of switches to couple the plurality of positive polarity output buffers to respective even signal lines during a second phase of the display driving period;
a third set of switches to couple the plurality of negative polarity output buffers to respective odd signal lines during the second phase of the display driving period;
a fourth set of switches to couple the signals lines to each other during a charge share period between the first phase of the display driving period and the second phase of the display driving period, and to couple the signals lines to each other during the touch sensor driving period; and
a fifth switch to couple the signal lines to an oscillating input voltage during the touch sensor driving period, the oscillating input voltage having an approximately same phase as the touch sensor driving signal.

2. The touch display device of claim 1 , wherein for a given odd signal line, a first one of the first set of switches couples the given odd signal line to one of the positive polarity output buffers during the first phase of the display driving period, and one of the third set of switches couples the given odd signal line to one of the negative polarity output buffers during the second phase of the display driving period.

3. The touch display device of claim 2 , wherein for a given even signal line, a second one of the first set of switches couples the given even signal line to the one of the negative polarity output buffers during the first phase of the display driving period, one of the second set of switches couples the given even signal line to the one of the positive polarity output buffers during the second phase of the display driving period.

4. A touch display device, comprising:
a timing controller to generate a sync signal for controlling timing of a touch sensor driving period and a display driving period in each of a plurality of frames, the touch sensor driving period and the display driving period alternating with each other, the display driving period comprising a first phase to drive odd signal lines according to a first polarity and to drive even signal lines according to a second polarity, a second phase to drive the odd signal lines according to the second polarity and to drive the even signal lines according to the first polarity, and a charge share period between the first phase and the second phase;
a display panel comprising a plurality of display pixels having a common electrode segmented into a plurality of touch sensors, the plurality of display pixels to display pixel data in response to data voltages during the display driving period;
a touch sensor driving circuit to supply a touch sensor driving signal to the plurality of touch sensors during the touch sensor driving period and to detect if a touch occurred based on a change in charge on the touch sensors;
a set of charge sharing switches to couple the odd and even signal lines together during the charge share period and to couple the odd and even signal lines together during the touch sensor driving period; and
a timing switch to couple the odd and even signal lines to receive an oscillating signal during the touch period and to decouple the odd and even signal lines from the oscillating signal during the display driving period.

5. The touch display device of claim 4 , further comprising:
a plurality of positive polarity output buffers to output data voltages having the first polarity;
a plurality of negative polarity output buffers to output data voltages having the second polarity;
a first set of switches to couple the plurality of positive polarity output buffers to the odd signal lines and to couple the plurality of negative polarity output buffers to the even signal lines during the first phase of the display driving period; and
a second set of switches to couple the plurality of positive polarity output buffers to the even signal lines during the second phase of the display driving period.

6. The touch display device of claim 5 , further comprising:
a third set of switches to couple the plurality of negative polarity output buffers to the odd signal lines during the second phase of the display driving period.

7. The touch display device of claim 6 , wherein for a given odd signal line, a first one of the first set of switches couples the given odd signal line to a first one of the positive polarity output buffers during the first phase of the display driving period, and one of the third set of switches couples the given odd signal line to one of the negative polarity output buffers during the second phase of the display driving period.

8. The touch display device of claim 7 , wherein for a given even signal line, a second one of the first set of switches couples the given even signal line to the one of the negative polarity output buffers during the first phase of the display driving period, and one of the second set of switches couples the given even signal line to the one of the positive polarity output buffers during the second phase of the display driving period.

9. The touch display device of claim 4 , wherein the oscillating signal has an approximately same phase as the touch sensor driving signal during the touch sensor driving period.

10. A method for operating a touch display device, the method comprising:
generating, by a timing controller, a sync signal for controlling timing of a touch sensor driving period and a display driving period in each of a plurality of frames, the touch sensor driving period and the display driving period alternating with each other, the display driving period comprising a first phase, a second phase, and a charge share period between the first and second phases;
driving odd signal lines of a display panel according to a first polarity and even signal lines according to a second polarity during the first phase of the display driving period;
driving the odd signal lines of the display panel according to the second polarity and the even signal lines according to the first polarity during the second phase of the display driving period;
displaying, by the display panel, pixel data in response to data voltages driven onto the odd and even signal lines during the display driving period, the display panel comprising a plurality of display pixels having a common electrode segmented into a plurality of touch sensors;
controlling a s

Assignees

• Lg Display Co Ltd

Inventors

• Cho Soondong
• Jang Hoon
• Kim Hoonbae

Classifications

• G09G3/3688

  suitable for active matrices only · CPC title

• G09G3/3655 Primary

  Details of drivers for counter electrodes, e.g. common electrodes for pixel capacitors or supplementary storage capacitors · CPC title

• G06F3/044

  by capacitive means · CPC title

• G06F3/0412 Primary

  Digitisers structurally integrated in a display · CPC title

• G06F3/0418

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