Display device and method of driving the same

Patent metadata

Field	Value
Publication number	US-10902818-B2
Application number	US-201916503850-A
Country	US
Kind code	B2
Filing date	Jul 5, 2019
Priority date	Jul 12, 2018
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A display device and a method of driving the same are provided. The display device includes a control signal generator that generates a control signal, a first demultiplexer that time-divides a data voltage from a first channel of a data driver and distributes the data voltage from the first channel to two or more data lines, in response to the control signal, a signal delay part that delays the control signal, and a second demultiplexer that time-divides a data voltage from a second channel of the data driver and distributes the data voltage from the second channel to other two or more data lines, in response to the control signal delayed by the signal delay part.

First claim

What is claimed is:

1. A display device comprising:
a control signal generator that generates a control signal;
a first demultiplexer configured to time-divide a data voltage from a first channel of a data driver and distribute the data voltage from the first channel to two or more data lines, in response to the control signal;
a signal delay part configured to delay the control signal;
a second demultiplexer configured to time-divide a data voltage from a second channel of the data driver and distribute the data voltage from the second channel to other two or more data lines, in response to the control signal delayed by the signal delay part; and
a control signal transmission line configured to be connected to the control signal generator, the signal delay unit, the first demultiplexer, and the second demultiplexer,
wherein the control signal transmission line includes:
a first closed-loop line configured to supply the control signal to a control node of the first demultiplexer; and
a second closed-loop line configured to supply the control signal delayed by the signal delay part to a control node of the second demultiplexer.

2. The display device of claim 1 , wherein the first demultiplexer sequentially connects the first channel of the data driver to first and second data lines by using first and second switching elements, and the second demultiplexer sequentially connects the second channel of the data driver to third and fourth data lines by using third and fourth switching elements,
wherein the control signal comprises:
a first switch control signal that controls the first and third switching elements; and
a second switch control signal that controls the second and fourth switching elements.

3. The display device of claim 2 , wherein the control signal transmission line further includes:
a (1-1)th control signal line that supplies the first switch control signal to a control node of the first switching element;
a (1-2)th control signal line connected to a control node of the third switching element;
a (2-1)th control signal line that supplies the second switch control signal to a control node of the second switching element; and
a (2-2)th control signal line connected to a control node of the fourth switching element,
wherein the signal delay part comprises:
a first signal delay part configured to be connected between the (1-1)th control signal line and the (1-2)th control signal line, and delay the first switch control signal and supply a delayed first switch control signal to the (1-2)th control signal line; and
a second signal delay part configured to be connected between the (2-1)th control signal line and the (2-2)th control signal line, and delay the second switch control signal and supply a delayed second switch control signal to the (2-2)th control signal line.

4. The display device of claim 3 , wherein the data driver comprises a plurality of driver ICs including a first driver IC and a second driver IC,
wherein the first channel is one of channels in the first driver IC, and the second channel is one of channels in the second driver IC.

5. The display device of claim 3 , wherein the data lines and the demultiplexers are arranged on a substrate of a display panel comprising a pixel array, and the control signal lines and the signal delay parts are arranged on a printed circuit board electrically connected to the display panel.

6. The display device of claim 3 , where in the first closed-loop line includes:
a (1-1)th bypass line that connects the (1-1)th control signal line to the control node of the first switching element; and
a (2-1)th bypass line that connects the (2-1)th control signal line to the control node of the second switching element,
the second closed-loop line including:
a (1-2)th bypass line that connects the (1-2)th control signal line to the control node of the third switching element;
a (2-2)th bypass line that connects the (2-2)th control signal line to the control node of the fourth switching element.

7. The display device of claim 3 , wherein the data lines are connected to pixels to which pixel data is written during a display period, the first and second switching elements are alternately turned on and off in every horizontal period, and the third and fourth switching elements are alternately turned on and off in every horizontal period.

8. The display device of claim 3 , further comprising:
a display panel comprising sensor lines that are connected to touch sensors, along with the data lines; and
a touch sensor driver configured to supply a signal to the sensor lines to drive the touch sensors.

9. The display device of claim 8 , wherein one frame period is time-divided into one or more display periods and one or more touch sensing periods,
wherein the data driver outputs a data voltage during the display period, and the touch sensor driver drives the touch sensors during the touch sensing period to amplify and integrate a signal from the touch sensors and convert the integrated value to digital data.

10. The display device of claim 9 , wherein the first and second switching elements are alternately turned on and off in every horizontal period during the display period to distribute a data voltage received through the first channel to the first and second data lines, and then are kept in the on state after a stabilization time of the touch sensing period, and
the third and fourth switching elements are alternately turned on and off in every horizontal period during the display period to distribute a data voltage received through the second channel to the third and fourth data lines, and then are kept in the on state after the stabilization time.

11. The display device of claim 10 , wherein the touch sensor driver starts operating after the stabilization time.

12. The display device of claim 11 , wherein a falling edge timing of the last switch control signal is within the stabilization time.

13. The display device of claim 9 , further comprising:
a first bypass line configured to selectively connect the (1-1)th control signal line and the (1-2)th control signal line by using a first bypass switching element; and
a second bypass line configured to selectively connect the (2-1)th control signal line and the (2-2)th control signal line by using a second bypass switching element.

14. The display device of claim 13 , wherein the first bypass switching element is turned on during the touch sensing period under control of the control signal generator to connect the (1-1)th control signal line and the (1-2)th control signal line, and the second bypass switching element is turned on during the touch sensing period under control of the control signal generator to connect the (2-1)th control signal line and the (2-2)th control signal line.

15. The display device of claim 3 , wherein the first closed-loop line includes:
a (1-1)th closed-loop line configured to connect the (1-1)th control signal line to the control node of the first switching element; and
a (2-1)th closed-loop line configured to connect the (2-1)th control signal line to the control node of the second switching element,
wherein the second closed-loop line including:
a (1-2)th closed-loop line configured to connect the (1-2)th control signal line to the control node of the third switching element; and
a (1-2)th closed-loop line configured to connect the (2-2)th control signal line connected to the control node of the fourth switching element.

16. The display device of claim 15 , wherein the first switch control signal is supplied to the control node of the

Assignees

• Lg Display Co Ltd

Inventors

• Kim Dongju
• Cho Soondong
• Jang Hoon
• Kim Jongwoo
• Hur Juno

Classifications

• G09G2310/0297

  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 title

• G09G2310/0272

  Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current · CPC title

• G09G2230/00

  Details of flat display driving waveforms · CPC title

• G09G5/001 Primary

  Arbitration of resources in a display system, e.g. control of access to frame buffer by video controller and/or main processor · CPC title

• H03K17/962

  Capacitive touch switches · CPC title