US 9,319,620 B2Granted

Video display device and television receiving device including luminance stretching

AssigneeSharp Kabushiki Kaisha

InventorsToshiyuki Fujine, Yoji Shiraya

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Abstract

A light emission portion of a video signal is detected, and the display intensity of the light emission portion is enhanced for emphasis display. At this moment, the intensity stretch amount is controlled in accordance with a status of video black display, thereby increasing the feeling of brightness and hence improving the video quality. An area-active-control/luminance-stretching portion stretches and increases the intensity of a backlight portion on the basis of an index related to a brightness calculated, on the basis of a predetermined condition, from the input video signal, and lowers the video signal intensity of the non-light emission part excluding the light emission part. At this moment, the area-active-control/luminance-stretching portion changes, in accordance with a black display amount detected by a black detection portion, a control curve that defines the relationship between the index related to the brightness and the stretch amount.

Claims6

Dependent claims

A television receiving device including a video display device, the video display device comprising:

a display portion for displaying an input video signal;
a light source for illuminating the display portion;
and a control portion for controlling the display portion and the light source, wherein
the control portion stretches and increases luminance of the light source based on control curves that define a relation between an index associated with brightness calculated based on a predetermined condition from the input video signal and a luminance stretch quantity for stretching the luminance of the light source, and
detects a light emitting part that is regarded as a video emitting light based on a predetermined feature quantity of the input video signal and reducing luminance of a video signal of a non-light emitting part excluding the light emitting part, to thereby enhance display luminance of the light emitting part, wherein
the video display device has a black detection portion detecting a quantity of black display based on a predetermined condition for black detection from the input video signal, and
the control portion switches the control curves according to the quantity of black display detected by the black detection portion,
wherein
the control portion divides an image by the input video signal into a plurality of areas, and changes a corresponding lighting rate of the light source for each of the areas based on a tone value of a video signal of the divided area,
the control curve is a control curve that defines a relation between an average lighting rate obtained by averaging the lighting rates corresponding to all areas and a luminance stretch quantity shown by possible maximum luminance on a screen of the display portion, and
the control portion uses the average lighting rate as the index associated with the brightness to stretch the luminance of the light source based on the maximum luminance defined in accordance with the average lighting rate.

8 more elements

A television receiving device including a video display device, the video display device comprising:

a display portion for displaying an input video signal;
a light source for illuminating the display portion;
and a control portion for controlling the display portion and the light source, wherein
the control portion stretches and increases luminance of the light source based on control curves that define a relation between an index associated with brightness calculated based on a predetermined condition from the input video signal and a luminance stretch quantity for stretching the luminance of the light source, and
detects a light emitting part that is regarded as a video emitting light based on a predetermined feature quantity of the input video signal and reducing luminance of a video signal of a non-light emitting part excluding the light emitting part, to thereby enhance display luminance of the light emitting part, wherein
the video display device has a black detection portion for detecting a quantity of black display based on a predetermined condition for black detection from the input video signal, and
the control portion switches the control curves according to the quantity of black display detected by the black detection portion,
wherein
the control curve is a control curve that defines a relation between a score obtained by counting the number of pixels by weighting brightness of each pixel and the luminance stretch quantity with respect to a video in a predetermined range including an area of the detected light emitting part, and
the control portion uses the score as the index associated with the brightness to stretch the luminance of the light source based on the score that is calculated from the input video signal.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/375,048Filed 10 Jul 2012
Priority: JP 2012-03038115 Feb 2012
Published: US 2015/0009411 A18 Jan 2015
Granted: 19 Apr 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

H04N 5/57
Receiver circuitry for the reception of television signals according to analogue transmission standards: control of contrast or brightness
G09G 3/3426
Using several illumination sources separately controlled corresponding to different display panel areas, e.g. along one dimension such as lines:…
H04N 5/66
Details of television systems: transforming electric information into light information
H04N 9/12
Details of colour television systems: picture reproducers