Luminance control unit and display device including the same

Patent metadata

Field	Value
Publication number	US-2020302861-A1
Application number	US-202016821658-A
Country	US
Kind code	A1
Filing date	Mar 17, 2020
Priority date	Mar 20, 2019
Publication date	Sep 24, 2020
Grant date	—

Abstract

A luminance control unit includes: a driving power voltage setting unit configured to determine a driving power voltage to be provided to a display panel, the driving power voltage corresponding to a target brightness, based on a plurality of driving power voltages respectively corresponding to a plurality of reference brightnesses of the display panel; and a gamma voltage setting unit configured to determine a target luminance corresponding to the target brightness, based on a plurality of target luminances respectively corresponding to the plurality of reference brightnesses, and to set gamma voltages for implementing the target luminance, wherein the driving power voltage and the gamma voltages are differently set with respect to the same reference brightness according to an ambient illumination intensity of the display panel.

First claim

What is claimed is:

1 . A luminance control unit comprising:
a driving power voltage setting unit configured to determine a driving power voltage to be provided to a display panel, the driving power voltage corresponding to a target brightness, based on a plurality of driving power voltages respectively corresponding to a plurality of reference brightnesses of the display panel; and a gamma voltage setting unit configured to determine a target luminance corresponding to the target brightness, based on a plurality of target luminances respectively corresponding to the plurality of reference brightnesses, and to set gamma voltages for implementing the target luminance, wherein the driving power voltage and the gamma voltages are differently set with respect to a same reference brightness according to an ambient illumination intensity of the display panel.

2 . The luminance control unit of claim 1 , wherein, when the ambient illumination intensity is less than an illumination intensity threshold value, a maximum value of the reference brightnesses is set smaller than a maximum reference brightness of the display panel.

3 . The luminance control unit of claim 2 , wherein the driving power voltage setting unit is configured to equally set the driving power voltage as a threshold driving power voltage, corresponding to reference brightnesses greater than a first threshold brightness, in response to the ambient illumination intensity being less than the illumination intensity threshold value.

4 . The luminance control unit of claim 3 , wherein the first threshold brightness is a minimum value of reference brightnesses with which an abnormal output is not viewed on the display panel when the display panel is driven by the threshold driving power voltage.

5 . The luminance control unit of claim 3 , further comprising a luminance modulator configured to correct the gamma voltages in response to an Average Pixel Level (APL) of input image data being greater than or equal to an APL threshold value.

6 . The luminance control unit of claim 5 , wherein the luminance modulator is configured to determine a correction luminance with respect to the target luminance, based on the target brightness, and to correct the gamma voltages to implement the correction luminance.

7 . The luminance control unit of claim 6 , wherein the luminance modulator is configured to equally set the correction luminance, corresponding to reference brightnesses greater than the first threshold brightness, in response to the ambient illumination intensity being less than the illumination intensity threshold value.

8 . The luminance control unit of claim 7 , wherein the luminance modulator is configured to set the correction luminance such that a difference between the correction luminance and the target luminance with respect to the maximum value of the reference brightnesses corresponds to a threshold correction offset, in response to the ambient illumination intensity being less than the illumination intensity threshold value.

9 . A display device comprising:
a display panel including a plurality of pixels; a luminance control unit configured to determine a driving power voltage, based on a target brightness of the display panel, and to set gamma voltages for implementing a target luminance corresponding to the target brightness; a display panel driver configured to drive the display panel, based on the gamma voltages; and a power provider configured to provide the determined driving power voltage to the display panel, wherein the driving power voltage and the gamma voltages are differently set with respect to a same reference brightness according to an ambient illumination intensity of the display panel.

10 . The display device of claim 9 , wherein the luminance control unit includes:
a driving power voltage setting unit configured to include a plurality of driving power voltages respectively corresponding to a plurality of reference brightnesses, and to determine the driving power voltage to be provided to the display panel, based on the target brightness; and a gamma voltage setting unit configured to include a plurality of target luminances respectively corresponding to the plurality of reference brightnesses, and to set the target luminance and the gamma voltages for implementing the target luminance, based on the target brightness.

11 . The display device of claim 10 , wherein a maximum value of the reference brightnesses is set smaller than a maximum reference brightness of the display panel in response to the ambient illumination intensity being less than an illumination intensity threshold value.

12 . The display device of claim 11 , wherein the driving power voltage setting unit is configured to equally set the driving power voltage as a threshold driving power voltage, corresponding to reference brightnesses greater than a first threshold brightness, in response to the ambient illumination intensity is less than the illumination intensity threshold value.

13 . The display device of claim 12 , wherein the luminance control unit further includes a luminance modulator configured to correct the gamma voltages, in response to an Average Pixel Level (APL) of input image data being greater than or equal to an APL threshold value.

14 . The display device of claim 13 , wherein the luminance modulator is configured to determine a correction luminance with respect to the target luminance, based on the target brightness, and to correct the gamma voltages to implement the correction luminance.

15 . The display device of claim 14 , wherein the luminance modulator equally sets the correction luminance, corresponding to reference brightnesses greater than the first threshold brightness, in response to the ambient illumination intensity being less than the illumination intensity threshold value.

16 . The display device of claim 15 , wherein the luminance modulator is configured to set the correction luminance such that a difference between the correction luminance and the target luminance with respect to the maximum value of the reference brightnesses corresponds to a threshold correction offset, in response to the ambient illumination intensity being less than the illumination intensity threshold value.

Assignees

• Samsung Display Co Ltd

Inventors

• Pyo Si Beak
• Kim Sung Kook

Classifications

• G09G2320/0673

  for control of gamma adjustment, e.g. selecting another gamma curve · CPC title

• G09G2360/144

  the light being ambient light · CPC title

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G2320/0626

  for control of overall brightness · CPC title

• G09G2330/021

  Power management, e.g. power saving · CPC title