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US 7,733,358 B2Granted
Liquid crystal display and driving method thereof
AssigneeChi Mei Optoelectronics Corp.
InventorYing-Hao Hsu
Life of this patent
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Abstract
In a display device having a light source and a storage for storing at least one reference frame of image data, a driving method includes receiving a current frame of image data; comparing grey levels between pixels of the current frame of image data and the corresponding pixels of the reference frame of image data; determining a pixel quantity of pixels having different grey levels in the current frame of image data and the reference frame of image data; and based on the determined pixel quantity, calculating and outputting a signal controlling a light emitting duty ratio and an amplitude of the light source while displaying the current frame. The display device further has a comparing unit and light source control unit for performing the driving method.
Claims20
A driving method for driving a display device comprising a light source and a storage for storing at least one reference frame of image data, the driving method comprising:
- receiving a current frame of image data;
- comparing grey levels between pixels of the current frame of image data and the corresponding pixels of the at least one reference frame of image data;
- determining a pixel quantity of pixels having different grey levels in the current frame of image data and the reference frame of image data;
- and based on the determined pixel quantity, calculating and outputting a signal controlling a light emitting duty ratio and an amplitude of the light source while displaying the current frame;
- wherein the display device further comprises an array S of 1×R, and after the step of determining the pixel quantity N(M) associated with the current frame of image data which is a Mth frame, the driving method further comprises, saving the determined pixel quantity N(M) in the array S, wherein the array S has a format of S=[N(M), N(M−1), N(M−2) . . . , N(M−(R−1))], and R represents the quantity of the at least one reference frame;
- and wherein the pixel quantity N(M) associated with the current frame of image data, which is a Mth frame having I×J pixels, is determined as
- N
-
- (
- M
- )
- =
- ∑
- i
- =
- 1
- I
-
- ∑
- j
- =
- 1
- J
-
- {
- Z
-
- (
- M
- )
-
- (
- i
- ,
- j
- )
- }
- ,
- where, when a difference between a pixel (i,j) of the Mth frame of image data and the corresponding pixel (i,j) of the reference frame of image data is equal to or greater than a threshold grey level difference, then Z(M)(i,j)=1, and when the difference between the pixel (i,j) of the M frame of image data and the corresponding pixel (i,j) of the reference frame of image data is less than said threshold grey level difference, then Z(M)(i,j)=0.
36 more elements
A driving method for driving a display device comprising a light source and a storage for storing at least one reference frame of image data, the driving method comprising:
- receiving a current frame of image data;
- comparing grey levels between pixels of the current frame of image data and the corresponding pixels of the at least one reference frame of image data;
- determining a pixel quantity of pixels having different grey levels in the current frame of image data and the reference frame of image data;
- and based on the determined pixel quantity, calculating and outputting a signal controlling a light emitting duty ratio and an amplitude of the light source while displaying the current frame;
- wherein the display device further comprises an array S of 1×R, and after the step of determining the pixel quantity N(M) associated with the current frame of image data which is a Mth frame, the driving method further comprises, saving the determined pixel quantity N(M) in the array S, wherein the array S has a format of S=[N(M), N(M−1), N(M−2) . . . N(M−(R−1))], and R represents the quantity of the at least one reference frame;
- wherein the light emitting duty ratio D is a function, D[N(M)], of the pixel quantity N(M), and the amplitude A of the light source is a function. A[N(M)], of the pixel quantity N(M);
- and wherein the light emitting duty ratio D is defined as:
- D
-
- [
- N
-
- (
- M
- )
- ]
- =
- [
- 1
- -
- N
-
- (
- M
- )
- N
- max
-
- (
- 1
- -
- D
- limit
- )
- ]
- ,
- wherein, Dlimit represents a threshold light emitting duty ratio of the light source, and Nmax represents a threshold pixel quantity.
34 more elements
A flat panel display, comprising:
- a display panel;
- a backlight source, disposed behind the display panel;
- and
- a data control circuit electrically connected to the display panel and the backlight source, the data control circuit comprising:
- an input for receiving image data to be displayed on the display panel, said image data comprising a current frame and a previous frame preceding the current frame;
- a comparing unit electrically connected to the input for receiving the current frame and for comparing the current frame of the image data with the previous frame of the image data;
- a frame image data storing unit electrically connected to the input for receiving and storing the previous frame, and electrically connected to the comparing unit for outputting the previous frame of the image data stored in the frame image data storing unit to the comparing unit;
- and
- a light source control unit electrically connected to the backlight source and said comparing unit for controlling, based on a comparison result received from said comparing unit, at least a driving parameter of the backlight source to provide controlled backlight to the display panel for displaying the current frame on the display panel;
- wherein the light source control unit further comprises a backlight source duty ratio controller and a backlight source amplitude controller, wherein a light emitting duty ratio of the backlight source is controlled by the backlight source duty ratio controller, and a light emitting amplitude of the backlight source is controlled by the backlight source amplitude controller, wherein the light emitting duty ratio D is a function, D[N(M)], of the pixel quantity N(M), and the amplitude A of the light source is a function, A[N(M)], of the pixel quantity N(M), wherein the light emitting duty ratio D is defined as:
- D
-
- [
- N
-
- (
- M
- )
- ]
- =
- [
- 1
- -
- N
-
- (
- M
- )
- N
- max
-
- (
- 1
- -
- D
- limit
- )
- ]
- ,
- and wherein, Dlimit represents a threshold light emitting duty ratio of the light source, and Nmax represents a threshold pixel quantity.
37 more elements
A driving method for driving a display device comprising a light source and a storage for storing at least one reference frame of image data, the driving method comprising:
- receiving a current frame of image data;
- comparing grey levels between pixels of the current frame of image data and the corresponding pixels of the at least one reference frame of image data;
- determining a pixel quantity of pixels having different grey levels in the current frame of image data and the reference frame of image data;
- and
- based on the determined pixel quantity, calculating and outputting a signal controlling a light emitting duty ratio and an amplitude of the light source while displaying the current frame;
- wherein the light emitting duty ratio D is a function, D[N(M)], of the pixel quantity N(M), and the amplitude A of the light source is a function, A[N(M)], of the pixel quantity N(M), wherein the light emitting duty ratio D is defined as:
- D
-
- [
- N
-
- (
- M
- )
- ]
- =
- [
- 1
- -
- N
-
- (
- M
- )
- N
- max
-
- (
- 1
- -
- D
- limit
- )
- ]
- ,
- and wherein, Dlimit represents a threshold light emitting duty ratio of the light source, and Nmax represents a threshold pixel quantity.
33 more elements
Dependencies are inferred from the claim text.