Liquid crystal display apparatus and program used for the same

• US 8,823,617 B2
• Filed: 03/20/2012
• Issued: 09/02/2014
• Est. Priority Date: 03/24/2011
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Kurosawa, Teppei
• Primary Examiner(s): Sasinowski, Andrew
• Application Number:
  US13/424,469
• Publication Number:
  US 20120242717A1
• Time in Patent Office: 896 Days
• Field of Search: 345 88- 89, 345/690
• US Class Current: 345/88
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 2320/0271 Adjustment of the gradation levels within the range of the gradation scale, e.g. by redistribution or clipping
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/001 using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background slide projectors per se G03B23/00 = 42 HP
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 5/20 Circuitry for controlling amplitude response
• CPC Class Codes: H04N 9/3182 Colour adjustment, e.g. white balance, shading or gamut white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607

Abstract

A liquid crystal display apparatus includes a feature amount generator configured to generate a feature amount based on the number of pixel pairs that satisfy a correspondence relationship between a gradation value of a target pixel and a gradation value of a surrounding pixel around the target pixel for a image represented by an input image signal, a processor configured to provide processing so as to set a correction value that reduces a dynamic range of a gradation value of the input image signal when the feature amount is larger than a first threshold, and so as not to set the correction value when the feature amount is equal to or smaller than the first threshold, and a liquid crystal driver configured to drive a liquid crystal display element based on the input image signal that has been corrected by the correction value.

Claims

1. A liquid crystal display apparatus configured to display an input image signal using a liquid crystal display element, the liquid crystal display apparatus comprising:

a feature amount generator configured to generate a feature amount of an entire area that includes a plurality of pixels, by sequentially setting a target pixel to each of the plurality of pixels, by obtaining information of the number of pixel pairs that satisfy a correspondence relationship between a gradation value of the target pixel and a gradation value of a surrounding pixel around the target pixel at each position of the target pixel, and by superimposing the number of pixel pairs, for an image represented by the input image signal;

a processor configured to provide processing for the entire image so as to set a correction value that reduces a dynamic range of a gradation value of the input image signal when the feature amount is larger than a first threshold, and so as not to set the correction value when the feature amount is equal to or smaller than the first threshold; and

a liquid crystal driver configured to drive the liquid crystal display element based on the input image signal that has been corrected by the correction value.

2. The liquid crystal display apparatus according to claim 1, wherein the feature amount generator sequentially sets the target pixel to each of all pixels in the image, and generates a feature amount of an overall image, and

wherein the processor sets the correction value for the overall image.

3. The liquid crystal display apparatus according to claim 1, wherein the image includes a plurality of rectangular area, each of which includes 100 pixels or more in one side,

wherein the feature amount generator generates a feature amount for each area by sequentially setting the target pixel for each of all pixels in each area, and

wherein the processor sets the correction value for each area.

4. The liquid crystal display apparatus according to claim 1, wherein the image includes a plurality of rectangular area, each of which includes 100 pixels or more on one side,

wherein the feature amount generator generates a feature amount for each area by sequentially setting the target pixel for each of all pixels in each area, and

wherein the processor sets the correction amount corresponding to the feature amount of each area for a central coordinate of each area, and sets a correction amount at a coordinate other than the central coordinate of each area through an interpolation and the correction amount of the central coordinate of each area.

5. The liquid crystal display apparatus according to claim 4, wherein the processor modifies at least one of a maximum value and a minimum value of the correction values of the central coordinates so that the a difference between the maximum value and the minimum value of the correction values of the central coordinates in the image can be smaller than a second threshold, and

wherein the processor sets the correction amount of the coordinate other than the central coordinate using the interpolation and a modified correction amount of the central coordinate.

6. The liquid crystal display apparatus according to claim 1, wherein the feature amount generator generates a plurality of feature amounts in accordance with a plurality of gradation value ranges of the target pixel and a plurality of gradation value ranges of the surrounding pixel, and

wherein the processor modifies the first threshold in accordance with the gradation value ranges of the surrounding pixel.

7. A non-transitory computer-readable storage medium storing a program that enables a computer to execute a method for displaying an input image signal on a display apparatus using a liquid crystal display element, the method comprising:

a feature amount generating step of generating a feature amount of an entire area that includes a plurality of pixels, by sequentially setting a target pixel to each of the plurality of pixels, by obtaining information of the number of pixel pairs that satisfy a correspondence relationship between a gradation value of the target pixel and a gradation value of a surrounding pixel around the target pixel at each position of the target pixel, and by superimposing the number of pixel pairs, for an image represented by the input image signal;

a processing step of providing processing for the entire image so as to set a correction value that reduces a dynamic range of a gradation value of the input image signal when the feature amount is larger than a first threshold, and so as not to set the correction value when the feature amount is equal to or smaller than the first threshold; and

a liquid crystal driving step of driving the liquid crystal display element based on the input image signal that has been corrected by the correction value.