Display device capable of gray scale expansion

Patent metadata

Field	Value
Publication number	US-10789900-B2
Application number	US-201816059335-A
Country	US
Kind code	B2
Filing date	Aug 9, 2018
Priority date	Dec 11, 2017
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

A display device includes: a data driver for driving a plurality of data lines; a voltage generator for generating at least one driving voltage to be provided to the data driver; and a driving controller for providing a second image signal and a reference gamma selection signal to the data driver in response to a first image signal and a control signal received from the outside, wherein the driving controller outputs a voltage control signal for changing a voltage level of the at least one driving voltage, and the reference gamma selection signal, based on metadata included in the first image signal, and the data driver receives the reference gamma selection signal and the at least one driving voltage to provide, to the plurality of data lines, data voltage signals corresponding to the second image signal.

First claim

What is claimed is:

1. A display device comprising:
a display panel comprising a plurality of pixels respectively connected to a plurality of gate lines and a plurality of data lines;
a gate driver to drive the plurality of gate lines;
a data driver to drive the plurality of data lines;
a voltage generator to generate at least one driving voltage to be provided to the data driver; and
a driving controller to provide a second image signal and a reference gamma selection signal to the data driver, and to control the gate driver, in response to a first image signal and a control signal,
wherein the driving controller is configured to output a voltage control signal for changing a voltage level of the at least one driving voltage, and to output the reference gamma selection signal, based on metadata included in the first image signal, and
the data driver is configured to receive the reference gamma selection signal and the at least one driving voltage to provide data voltage signals corresponding to the second image signal to the plurality of data lines,
wherein the driving controller comprises:
a metadata analysis circuit to analyze the metadata to obtain a maximum luminance signal and a minimum luminance signal;
a bit expansion circuit to convert the first image signal into an expanded image signal between a maximum gray level corresponding to the maximum luminance signal and a minimum gray level corresponding to the minimum luminance signal; and
a gamma correction circuit to convert the expanded image signal into the second image signal,
wherein the gamma correction circuit is configured to output the voltage control signal and the reference gamma selection signal in response to the maximum luminance signal and the minimum luminance signal,
wherein the voltage generator is configured to generate a first driving voltage and a second driving voltage in response to the voltage control signal, and
wherein the data driver comprises:
a resistor string to generate a plurality of gamma voltages between the first driving voltage and the second driving voltage;
a reference voltage selection circuit to select some of the plurality of gamma voltages in response to the reference gamma selection signal, and to output the selected gamma voltages as a plurality of reference gamma voltages;
a second voltage generator to generate a plurality of voltages based on the plurality of reference gamma voltages; and
a decoder to output voltages, of the plurality of voltages, corresponding to the second image signal as gray scale voltages,
wherein the gray scale voltages are respectively provided to the plurality of data lines as the data voltage signals.

2. The display device of claim 1 , wherein the second driving voltage has a lower voltage level than the first driving voltage.

3. The display device of claim 1 , wherein a voltage level of the first driving voltage is determined depending on the maximum luminance signal, and a voltage level of the second driving voltage is determined depending on the minimum luminance signal.

4. The display device of claim 1 , wherein the reference voltage selection circuit comprises a plurality of selectors each of which is configured to receive the plurality of gamma voltages, and to output one of the plurality of gamma voltages as a reference gamma voltage in response to the reference gamma selection signal.

5. The display device of claim 1 , wherein the resistor string comprises a plurality of resistors sequentially connected in series between the first driving voltage and the second driving voltage, and configured to output voltages of connecting nodes between the plurality of resistors as the plurality of gamma voltages.

6. The display device of claim 1 , wherein the metadata is included in a vertical blanking interval of the first image signal.

7. A display device comprising:
a display panel comprising a plurality of pixels respectively connected to a plurality of gate lines and a plurality of data lines;
a gate driver to drive the plurality of gate lines;
a data driver to drive the plurality of data lines;
a voltage generator to generate at least one driving voltage and a plurality of reference gamma voltages to be provided to the data driver; and
a driving controller to provide a second image signal to the data driver, and to control the gate driver, in response to a first image signal, a control signal and metadata, wherein:
the driving controller is configured to output a voltage control signal for changing voltage levels of the at least one driving voltage and the plurality of reference gamma voltages based on luminance information included in the metadata in the first image signal, and
the data driver is configured to receive the plurality of reference gamma voltages and the at least one driving voltage to provide data voltage signals corresponding to the second image signal to the plurality of data lines,
wherein the voltage generator is configured to generate a first driving voltage and a second driving voltage in response to the voltage control signal,
wherein the data driver comprises:
a resistor string to generate a plurality of voltages between the first driving voltage and the second driving voltage based on the plurality of reference gamma voltages; and
a decoder to output voltages, of the plurality of voltages, corresponding to the second image signal as gray scale voltages,
wherein the gray scale voltages are respectively provided to the plurality of data lines as the data voltage signals.

8. The display device of claim 7 , wherein
the second driving voltage has a lower voltage level than the first driving voltage, and
the plurality of reference gamma voltages has voltage levels different from each other between the first driving voltage and the second driving voltage.

9. The display device of claim 7 , wherein the resistor string comprises a plurality of resistors sequentially connected in series between the first driving voltage and the second driving voltage, and configured to output voltages of connecting nodes between the plurality of resistors as the plurality of voltages.

10. The display device of claim 7 , wherein the metadata is included in a vertical blanking interval of the first image signal.

Assignees

• Samsung Display Co Ltd

Inventors

• Kim Kang-Min
• Choi Nam-Gon
• Kim Namheon
• Park Joohwan
• Lee Jang-Mi
• Yi Junghwan

Classifications

• G09G2320/0276

  for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction · CPC title

• G09G2310/0286

  Details of a shift registers arranged for use in a driving circuit · CPC title

• G09G2320/0242

  Compensation of deficiencies in the appearance of colours · CPC title

• G09G3/3648

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title

• G09G3/3233

  with pixel circuitry controlling the current through the light-emitting element · CPC title