Image display control apparatus and image display control method

• US 7,202,850 B2
• Filed: 11/25/2003
• Issued: 04/10/2007
• Est. Priority Date: 11/26/2002
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Kitagawa, Daisaku
• Primary Examiner(s): Awad; Amr A.
• Assistant Examiner(s): Sherman; Stephen G
• Application Number:
  US10/720,082
• Publication Number:
  US 20040104877A1
• Time in Patent Office: 1,232 Days
• Field of Search: 345/102, 345/87, 345/204, 345/214, 349/61
• US Class Current: 345/102
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 2320/0646 Modulation of illumination source brightness and image signal correlated to each other
• CPC Class Codes: G09G 2340/0428 Gradation resolution change
• CPC Class Codes: G09G 2360/16 Calculation or use of calculated indices related to luminance levels in display data
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

An image display control apparatus having a small-size circuit includes: an image state detection unit for detecting a state of an image based on an image signal using a resource subunit in a resource unit; an image signal transformation unit for transforming the image signal, using the resource subunit in the resource unit, based on the state of the image detected by the image state detection unit; and a resource control unit for assigning the resource subunit in the resource unit to each of the image state detection unit and the image signal transformation unit according to a count number of cycles of an operation clock outputted from a clock unit.

Claims

1. An image display control apparatus that controls light transmittance of liquid crystals of a liquid crystal display screen for displaying an image based on an inputted image signal and controls, according to the light transmittance of the liquid crystals, an amount of light emitted by a backlight unit for illuminating a back of the liquid crystal display screen based on the image signal, the image display control apparatus comprising:

an image state detection unit operable to detect a state of the image based on the image signal;

an image signal transformation unit operable to transform the image signal by performing predetermined signal processing on said image signal based on the state of the image detected by the image state detection unit, and control the light transmittance of the liquid crystals based on the transformed image signal; and

a resource control unit operable to;

assign an arithmetic operation resource, which performs an arithmetic operation, to the image state detection unit, instead of to the image signal transformation unit, at a predetermined time when the image state detection unit is to use the arithmetic operation resource; and

assign the arithmetic operation resource to the image signal transformation unit, instead of to the image state detection unit, at a predetermined time when the image signal transformation unit is to use the arithmetic operation resource, which is different than the predetermined time when the image state detection unit is to use the arithmetic operation resource,

wherein the image state detection unit detects the state of the image using the assigned arithmetic operation resource, and

the image signal transformation unit transforms the image signal using the assigned arithmetic operation resource.

2. The image display control apparatus according to claim 1, further comprising a color space transformation unit operable to transform a color component signal including R, G and B component signals in the image signal into a color information signal including at least a brightness signal and a chroma signal, and output said color information signal to the image signal transformation unit,

wherein the resource control unit assigns the arithmetic operation resource exclusively to the color space transformation unit at a predetermined timing, and

the color space transformation unit transforms the color component signal into the color information signal using the assigned arithmetic operation resource.

3. The image display control apparatus according to claim 2, further comprising a second color space transformation unit operable to transform the color information signal including at least the brightness signal and the chroma signal into the color component signal the R, G and B component signals and output said transformed color component signal, said color information signal being the image signal transformed by the image signal transformation unit,

wherein the resource control unit assigns the arithmetic operation resource exclusively to the second color space transformation unit at a predetermined timing, and

the second color space transformation unit transforms the color information signal into the color component signal using the assigned arithmetic operation resource.

4. The image display control apparatus according to claim 3,

wherein the image signal transformation unit includes:

a brightness transformation unit operable to transform the brightness signal outputted from the color space transformation unit, based on the state of the image detected by the image state detection unit; and

a chroma transformation unit operable to transform the chroma signal outputted from the color space transformation unit, based on the state of the image detected by the image state detection unit,

the resource control unit assigns the arithmetic operation resource exclusively to the brightness transformation unit at a predetermined timing, and assigns the arithmetic operation resource exclusively to the chroma transformation unit at a predetermined timing,

the brightness transformation unit transforms the brightness signal using the assigned arithmetic operation resource, and

the chroma transformation unit transforms the chroma signal using the assigned arithmetic operation resource.

5. The image display control apparatus according to claim 4, further comprising a clock signal generation unit operable to generate a clock signal,

wherein the resource control unit counts cycles of the clock signal generated by the clock signal generation unit and assigns the arithmetic operation resource according to a count number.

6. The image display control apparatus according to claim 5,

wherein each of the image state detection unit, the image signal transformation unit, the color space transformation unit and the second color space transformation unit performs predetermined processing on each pixel in the image signal, and

a time interval between inputs of said each pixel in the image signal is longer than the cycle of the clock signal generated by the clock signal generation unit.

7. The image display control apparatus according to claim 6, comprising a plurality of resource units equipped with the arithmetic operation resources respectively,

wherein the resource control unit assigns one or plural number of the resource units to each of the image state detection unit, the image signal transformation unit, the color space transformation unit and the second color space transformation unit, said number of the resource units to be assigned being determined according to the processing performed respectively by each of the image state detection unit, the image signal transformation unit, the color space transformation unit and the second color space transformation unit.

8. The image display control apparatus according to claim 7,

wherein the arithmetic operation resource is a multiplication unit.

9. The image display control apparatus according to claim 8,

wherein the image state detection unit detects the state of the image of each frame based on the image signal, and

the image signal transformation unit transforms an image signal of a frame which is to be inputted subsequently to said each frame based on the state of the image of said each frame detected by the image state detection unit.

10. An image display control method executed by an image display control apparatus that controls light transmittance of liquid crystals of a liquid crystal display screen for displaying an image based on an inputted image signal and controls, according to the light transmittance of the liquid crystals, an amount of light emitted by a backlight unit for illuminating a back of the liquid crystal display screen based on the image signal, the image display control method comprising:

an image state detection step of detecting a state of the image based on the image signal;

an image signal transformation step of transforming the image signal by performing predetermined signal processing on said image signal based on the state of the image detected in the image state detection step, and controlling the light transmittance of the liquid crystals based on the transformed image signal; and

a resource control step of;

assigning an arithmetic operation resource, which performs an arithmetic operation, to an image state detection unit operable to execute the image state detection step, instead of to an image signal transformation unit operable to execute the image signal transformation step, at a predetermined time when the image state detection unit is to use the arithmetic operation resource; and

assigning the arithmetic operation resource to the image signal transformation unit, instead of to the image state detection unit, at a predetermined time when the image signal transformation unit is to use the arithmetic operation resource, which is different than the predetermined time when the image state detection unit is to use the arithmetic operation resource,

wherein in the image state detection step, the image state detection unit detects the state of the image using the assigned arithmetic operation resource, and

in the image signal transformation step, the image signal transformation unit transforms the image signal using the assigned arithmetic operation resource.

11. The image display control method according to claim 10,

wherein in the resource control step, cycles of a clock signal generated by a clock signal generation unit are counted, and the arithmetic operation resource is assigned according to a count number.

12. A program, embodied on a computer-readable medium, executed by an image display control apparatus that controls light transmittance of liquid crystals of a liquid crystal display screen for displaying an image based on an inputted image signal and controls, according to the light transmittance of the liquid crystals, an amount of light emitted by a backlight unit for illuminating a back of the liquid crystal display screen based on the image signal, the program causing the image display control apparatus to execute:

an image state detection step of detecting a state of the image based on the image signal;

an image signal transformation step of transforming the image signal by performing predetermined signal processing on said image signal based on the state of the image detected in the image state detection step, and controlling the light transmittance of the liquid crystals based on the transformed image signal; and

a resource control step of;

assigning an arithmetic operation resource, which performs an arithmetic operation, to an image state detection unit operable to execute the image state detection step, instead of to an image signal transformation unit operable to execute the image signal transformation step, at a predetermined time when the image state detection unit is to use the arithmetic operation resource; and

assigning the arithmetic operation resource to the image signal transformation unit, instead of to the image state detection unit, at a predetermined time when the image signal transformation unit is to use the arithmetic operation resource, which is different than the predetermined time when the image state detection unit is to use the arithmetic operation resource,

wherein in the image state detection step, the image state detection unit detects the state of the image using the assigned arithmetic operation resource, and

in the image signal transformation step, the image signal transformation unit transforms the image signal using the assigned arithmetic operation resource.

13. An image display apparatus comprising:

a liquid crystal display screen operable to display an image;

a backlight unit operable to illuminate a back of the liquid crystal display screen;

an image display control apparatus that controls light transmittance of liquid crystals of the liquid crystal display screen based on an inputted image signal and controls, according to the light transmittance of the liquid crystals, an amount of light emitted by the backlight unit based on the image signal,

wherein the image display control apparatus includes;

an image state detection unit operable to detect a state of the image based on the image signal;

an image signal transformation unit operable to transform the image signal by performing predetermined signal processing on said image signal based on the state of the image detected by the image state detection unit, and control the light transmittance of the liquid crystals based on the transformed image signal; and

a resource control unit operable to;

assign an arithmetic operation resource, which performs an arithmetic operation, to the image state detection unit, instead of to the image signal transformation unit, at a predetermined time when the image state detection unit is to use the arithmetic operation resource; and

assign the arithmetic operation resource to the image signal transformation unit, instead of to the image state detection unit, at a predetermined time when the image signal transformation unit is to use the arithmetic operation resource, which is different than the predetermined time when the image state detection unit is to use the arithmetic operation resource,

wherein the image state detection unit detects the state of the image using the assigned arithmetic operation resource, and

the image signal transformation unit transforms the image signal using the assigned arithmetic operation resource.