Display device and television receiver

• US 9,230,487 B2
• Filed: 02/25/2013
• Issued: 01/05/2016
• Est. Priority Date: 03/05/2012
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Gotoh, Toshiyuki
• Primary Examiner(s): HSIA, SHERRIE Y
• Application Number:
  US14/382,652
• Publication Number:
  US 20150055025A1
• Time in Patent Office: 1,044 Days
• Field of Search: 348/790, 348/566, 348/671, 348/687, 348/674, 348/675, 345/629, 345/690, 345/77, 345/617, 345/89, 345/694
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G09G 2320/0276 for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction
• CPC Class Codes: G09G 2320/062 Adjustment of illumination source parameters
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2320/0686 with two or more screen areas displaying information with different brightness or colours
• CPC Class Codes: G09G 2380/08 Biomedical applications
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: H04N 5/20 Circuitry for controlling amplitude response
• CPC Class Codes: H04N 5/202 Gamma control circuits for controlling camera response irrespective of the scene brightness H04N23/82
• CPC Class Codes: H04N 5/7408 Direct viewing projectors, e.g. an image displayed on a video CRT or LCD display being projected on a screen

Abstract

A display device that can adjust brightness of each of a plurality of regions of an image by performing local dimming executes local dimming in a case of displaying a multi-color image (color image), and does not execute local dimming in a case of displaying a grayscale image. Moreover, in a case of displaying a mixed image of a multi-color image and a grayscale image, the display device does not execute local dimming in regions including a grayscale image among a plurality of regions of an image. Displaying a multi-color image at high contrast and displaying a grayscale image at high tone reproduction are both achieved.

Claims

1. A display device capable of displaying a color image and a grayscale image, comprising:

an adjusting unit configured to adjust brightness of each of a plurality of regions of an image by performing local dimming; and

a first determining unit configured to determine whether an image to be displayed is a color image or a grayscale image,

wherein the adjusting unit adjusts brightness of the image by performing local dimming in a case where the first determining unit determines that the image to be displayed is a color image, and does not adjust brightness of the image by performing local dimming in a case where the first determining unit determines that the image to be displayed is a grayscale image.

2. The display device according to claim 1, further comprising:

a second determining unit configured to determine whether or not the image to be displayed is a mixed image of a color image and a grayscale image; and

a first specifying unit configured to specify a region including the grayscale image among the plurality of regions in a case where the second determining unit determines that the image to be displayed is the mixed image,

wherein the adjusting unit does not adjust brightness of the region specified by the first specifying unit by performing local dimming.

3. The display device according to claim 2, further comprising

a second specifying unit configured to specify, among regions not including the grayscale image, a region located within a predetermined range from the region including the grayscale image,

wherein the adjusting unit does not adjust brightness of the region specified by the second specifying unit by performing local dimming.

4. The display device according to claim 3, further comprising:

a first gamma correction unit configured to perform gamma correction on the color image with a predetermined gamma characteristic for a color image; and

a second gamma correction unit configured to perform gamma correction on the grayscale image with a gamma characteristic that conforms to the Grayscale Standard Display Function defined in the DICOM standards.

5. The display device according to claim 3, further comprising

a third gamma correction unit configured to perform gamma correction on color pixels included in the mixed image with a predetermined gamma characteristic for a color image, and to perform gamma correction on monochrome pixels included in the mixed image with a gamma characteristic that conforms to the Grayscale Standard Display Function defined in the DICOM standards.

6. The display device according to claim 2, further comprising:

a first gamma correction unit configured to perform gamma correction on the color image with a predetermined gamma characteristic for a color image; and

a second gamma correction unit configured to perform gamma correction on the grayscale image with a gamma characteristic that conforms to the Grayscale Standard Display Function defined in the DICOM standards.

7. The display device according to claim 2, further comprising

a third gamma correction unit configured to perform gamma correction on color pixels included in the mixed image with a predetermined gamma characteristic for a color image, and to perform gamma correction on monochrome pixels included in the mixed image with a gamma characteristic that conforms to the Grayscale Standard Display Function defined in the DICOM standards.

8. The display device according to claim 1, further comprising:

a first gamma correction unit configured to perform gamma correction on the color image with a predetermined gamma characteristic for a color image; and

a second gamma correction unit configured to perform gamma correction on the grayscale image with a gamma characteristic that conforms to the Grayscale Standard Display Function defined in the DICOM standards.

9. A television receiver, comprising:

the display device according to claim 1; and

a tuner receiving a television broadcast,

wherein the display device displays an image based on the television broadcast received by the tuner.