Method and apparatus for driving liquid crystal display
AssigneeLG Display Co., Ltd.
InventorKi Duk Kim
Life of this patent
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Abstract
A driving method and apparatus for a liquid crystal display is disclosed in which the contrast ratio of data to be displayed is expanded and brightness of a back light is selectively changed in correspondence with the data. Whether the data is that of an initial color field is determined. The data is converted into brightness components and arranged into a histogram for each frame. Data having an expanded contrast is generated by the histogram. A control value is extracted from the histogram. The brightness of the back light is generated in correspondence with the control value if an initial color field is not displayed. However, if an initial color field is displayed, a predetermined brightness is supplied irrespective of the extracted control value.
Claims49
A method of driving a display, comprising:
- determining whether data to be displayed is that of an initial color field by receiving red, green and blue data for each frame;
- changing a corresponding counted value when only one of the red, green and blue data has a gray level at least a preset amount while the remaining red, green and blue data has a gray level of less than the preset amount;
- determining that one of the red, green and blue data to be the initial color field when the corresponding counted value exceeds a predetermined critical value in which the corresponding counted value has been changed;
- and
- controlling a back light such that a corresponding predetermined brightness is supplied when the frame data is that of the initial color field.
A method of driving a frame of a display, comprising:
- (A) determining whether first data to be displayed for each frame is that of an initial color field;
- (B) converting the first data into brightness components and arranging the brightness components into a histogram;
- (C) generating second data having an expanded contrast using the histogram;
- (D) extracting a control value from the histogram;
- and
- (E) controlling brightness of a back light in correspondence with the control value if it is determined that the first data is not that of the initial color field, and controlling the back light to emit a predetermined brightness irrespective of the control value if it is determined that the first data is that of the initial color field.
A driving apparatus for a display, comprising:
- an initial color determiner that determines whether first data received at an input for each frame is an initial color field;
- an image signal modulator that extracts brightness components from the first data, converts the brightness components into a histogram for each frame, and generates second data having an expanded contrast in correspondence with a result extracted from the histogram;
- a back light that emits light;
- and
- a back light controller that controls brightness of the back light under control of the initial color determiner or the image signal modulator dependent on whether the first data is the initial color field.
A method of driving a display, the method comprising:
- determining whether an image to be displayed on the display for each frame is substantially a single color;
- determining a control value from a brightness of the image;
- expanding a contrast of the image using the control value;
- controlling a back light to emit light of a brightness independent of the control value if the image is substantially the single color and using the control value if the image is not substantially the single color;
- and
- displaying the image of expanded contrast using light from the back light.
Dependencies are inferred from the claim text.