Display device

Patent metadata

Field	Value
Publication number	US-2018024386-A1
Application number	US-201715655169-A
Country	US
Kind code	A1
Filing date	Jul 20, 2017
Priority date	Jul 20, 2016
Publication date	Jan 25, 2018
Grant date	—

Abstract

A display device includes: a display panel; a driving frequency converter circuit configured to convert a driving frequency according to an input image data. A common voltage controller outputs a common voltage data corresponding to the driving frequency; and a common voltage generator receives the common voltage data to generate a common voltage and outputs the common voltage to the display panel. The common voltage has an inclined waveform within an integer multiple of a frame period.

First claim

What is claimed is:

1 . A display device comprising:
a display panel; a driving frequency converter circuit configured to convert a driving frequency according to an input image data; a common voltage controller configured to control output of a common voltage data corresponding to the driving frequency; and a common voltage generator configured to receive the common voltage data and generate a common voltage and output the common voltage to the display panel, wherein the generated common voltage has an inclined waveform within an integer multiple of a frame period.

2 . The display device according to claim 1 , wherein the display panel includes:
a plurality of gate lines; a plurality of data lines insulated from and intersecting the plurality of gate lines; a plurality of pixels electrically connected to the plurality of gate lines and the plurality of data lines; wherein the display panel displays an image comprised of an output of each pixel according to a gate signal applied through the plurality of gate lines, and a data voltage applied through the plurality of data lines, and wherein a value of the common voltage decreases at a substantially similar rate during the integer multiple of the frame period.

3 . The display device according to claim 1 , wherein a value of the common voltage gradually decreases within the integer multiple of the frame period.

4 . The display device according to claim 1 , wherein a value of the common voltage gradually increases within the integer multiple of the frame period.

5 . The display device according to claim 1 , wherein the integer multiple of the frame period increases as the driving frequency decreases.

6 . The display device according to claim 1 , wherein the display panel is driven by a first frequency when the input image data is a moving image data, and driven by a second frequency when the input image data is a still image data.

7 . The display device according to claim 6 , wherein the first frequency is greater than the second frequency.

8 . The display device according to claim 6 , wherein a difference between a maximum value and a minimum value of the common voltage increases as the second frequency decreases.

9 . The display device according to claim 1 , further comprising a lookup table having the driving frequency and the common voltage data as variables.

10 . The display device according to claim 1 , further comprising a lookup table having the driving frequency, a gray scale and the common voltage data as variables.

11 . The display device according to claim 1 , further comprising:
a power management circuit unit configured to output a driving voltage and a gamma voltage; a timing controller configured to output an image data signal and a driving control signal; a data driver configured to convert the image data signal into a data voltage signal based on the driving voltage, the gamma voltage and the driving control signal; and a gate driver configured to output a gate signal based on the driving voltage and the driving control signal.

12 . The display device according to claim 11 , wherein the data voltage signal has a different polarity at every integer multiple of the frame period.

13 . The display device according to claim 11 , wherein the data voltage signal and the common voltage are refreshed at every integer multiple of the frame period.

14 . A display device comprising:
a display panel including a plurality of gate lines, and a plurality of data lines insulated from and intersecting the plurality of gate lines, and a plurality of pixels electrically connected to the plurality of gate lines and the plurality of data lines; a timing controller circuit configured to receive a digital image data and identify whether the digital image data comprises a still image data or a moving image data; a data driver circuit configured to convert a digital image data signal into analog image data signals applied to the plurality of data lines; a gate driver circuit configured to generate gate signals in response output to the plurality of gate lines; a power management integrated circuit (PMIC) configured to: output a driving voltage and a gamma voltage to the data driver circuit, output the gate driving voltages to the gate driver circuit, and output a common voltage to the display panel; wherein the common voltage has an inclined waveform within an integer multiple of a frame period.

15 . The display device according to claim 14 , further comprising:
a common voltage generator that generates a common voltage data having the inclined waveform; and wherein the timing controller circuit is configured to receive the digital image data from an external source, and generate a common voltage data that is output to the common voltage generator; and the timing controller circuit includes a still image determinator circuit that identifies whether the digital image data comprises a still image or a moving image, and a common voltage controller that receives a frequency information and outputs the common voltage data corresponding to the frequency information to the common voltage generator.

16 . The display device according to claim 15 , further comprising a memory, and wherein a common voltage controller retrieves from the memory a particular common voltage data corresponding to a particular driving frequency from among a plurality of driving frequencies based on the frequency information.

17 . The display device according to claim 16 , wherein the memory comprises a lookup table including at least the frequency information, gray scale information and the common voltage data as variables.

18 . The display device according to claim 16 , wherein the common voltage data comprises different inclined waveforms according to a corresponding driving frequency identified in the frequency information, respectively.

19 . The display device according to claim 18 , wherein the display panel is driven by a first frequency when the digital image data is a moving image data and driven by a second frequency when the digital image data is a still image data, and a difference between a maximum value and a minimum value of the common voltage increases as the second frequency decreases.

20 . A non-transitory machine readable medium having stored thereon executable instructions to cause a display device to perform operations comprising:
converting, by a driving frequency converter circuit, a driving frequency according to whether input image data is a still image; providing, by a common voltage controller, output data and gate control signals to data drivers and gate drivers including the driving frequency; providing a common voltage to a display panel in which the common voltage corresponds to the driving frequency, wherein the common voltage has an inclined waveform within an integer multiple of a frame period of an image displayed by the display panel.

Assignees

• Samsung Display Co Ltd

Inventors

• Kim Dongin
• Park Jinkyu
• Lee Yohan
• Choi Kihoon
• Hong Hyunseok

Classifications

• G02F1/1335

  Structural association of cells with optical devices, e.g. polarisers or reflectors · CPC title

• H01L51/50

  Electricity · mapped topic

• G02F1/0123 Primary

  Circuits for the control or stabilisation of the bias voltage, e.g. automatic bias control [ABC] feedback loops · CPC title

• G02B6/0011

  the light guides being planar or of plate-like form · CPC title

• G09G3/2092 Primary

  Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto (suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165) · CPC title