Patent ID: 7786963
Filing Date: 2010-08-31
Classification: G09G

Abstract:
1. An apparatus for driving a display device, comprising: a histogram calculator to calculate a histogram of pixel data for an input image; a data stretching curve generator, which divides the histogram into n gray level areas, generates a data stretching curve for each gray level area having a gradient proportional to a total number of pixel data accumulated for each of the gray level areas, connects each data stretching curve by connecting a end point of a data stretching curve in the preceding gray level area to a starting point of a data stretching curve in the following gray level area, and modulates the pixel data of the input image by mapping the pixel data of the input image to the connected data stretching curves; a backlight unit irradiating a light to the display device; and a backlight controller controlling the backlight unit response to a control signal from the data stretching curve generator, wherein the backlight controller controls the output of the backlight unit in response to the control signal to supply to the backlight the driving dimming signal for increasing the brightness of the backlight for a bright image and decreasing the brightness of the backlight for a relatively dark image, wherein the data stretching curve generator generates the control signal corresponding to the calculated data from the histogram calculator, wherein the data stretching curve generator selects a data stretching curve of a pre-set minimum gradient in an area where the pixel data number is smaller than a minimum critical value in the histogram and a data stretching curve of a pre-set maximum gradient in an area where the pixel data number is greater than a maximum critical value, wherein n is a positive integer above 2, and wherein each gradient has a different value in proportion to the total number of pixel data for each gray level area and is defined as: wherein the gradient of the data stretching curve is determined between the pre-set maximum gradient and the pre-set minimum gradient.