GRAY SCALE DISPLAY DEVICE

• US 20110128263A1
• Filed: 07/28/2008
• Published: 06/02/2011
• Est. Priority Date: 07/28/2008
• Status: Abandoned Application

• Current Assignee: NEC Display Solutions, Ltd. (NEC Corporation)
• Original Assignee: NEC Display Solutions, Ltd. (NEC Corporation)
• Inventors: Abe, Masatoshi
• Application Number:
  US12/737,535
• Publication Number:
  US 20110128263A1
• Time in Patent Office: Days
• US Class Current: 345/207
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 21/42202 environmental sensors, e.g. for detecting temperature, luminosity, pressure, earthquakes
• CPC Class Codes: H04N 21/4318 by altering the content in the rendering process, e.g. blanking, blurring or masking an image region image enhancement or restoration in general G06T5/00
• CPC Class Codes: H04N 5/202 Gamma control circuits for controlling camera response irrespective of the scene brightness H04N23/82
• CPC Class Codes: H04N 5/58 in dependence upon ambient light

Abstract

Video signals are subjected to necessary signal processing by a video signal processing unit 1, subjected to conversion by an LUT unit 2 achieving a DICOM gamma characteristic, and output to a display unit 6. At this time, a CPU 3 refers to a memory 4 so as to read a decrement of luminance of a backlight 7 commensurate with an increment of screen luminance based on the output of an illumination sensor 5, thus instructing a backlight drive unit 8 to decrease the luminance of the backlight 7. This makes it possible to decrease the luminance of the backlight 7 by an increment of screen luminance owing to the brightness of the surrounding light. The CPU 3 corrects the black luminance reflecting a decrement of luminance of the backlight 7, thus updating the content of the LUT unit 2 achieving the DICOM gamma characteristic. Thus, it is possible to achieve good gray scale reproducibility irrespective of the influence of the surrounding light.

Claims

1. A gray scale display device comprising:

a conversion unit which inputs a video level of a video signal so as to convert and output it based on a table establishing a correlation between an input luminance value and a luminance value according to a DICOM gamma characteristic;

a display unit which displays the video signal converted by the conversion unit;

an illumination detection unit which detects the brightness of the surrounding light on a front face of the display unit; and

an update unit which updates the content of the table in response to the varying brightness of the surrounding light detected by the illumination detection unit.

2. The gray scale display device according to claim 1 further comprising a screen luminance control unit which varies a screen luminance of the display unit in response to the brightness of the surrounding light detected by the illumination detection unit.

3. A gray scale display method comprising the steps of:

inputting a luminance of a video signal and converting it based on a table establishing a correlation between an input luminance value and a luminance value according to a DICOM gamma characteristic;

displaying the converted video signal on a display unit;

detecting the brightness of the surrounding light on a front face of the display unit; and

updating the content of the table in response to the varying brightness of the detected surrounding light.

4. The gray scale display method according to claim 3 further comprising the step of varying a screen luminance of the display unit in response to the brightness of the detected surrounding light.