LIQUID CRYSTAL DISPLAY DEVICE, DRIVING CONTROL CIRCUIT AND DRIVING METHOD USED IN SAME DEVICE
First Claim
1. A liquid crystal display device comprising:
- a liquid crystal display panel;
a backlight; and
a driving control unit;
wherein said liquid crystal display panel displays images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage;
wherein said backlight illuminates the liquid crystal display panel from its rear side; and
wherein said driving control unit turns off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region and turns on said backlight at a point of time when the liquid crystal has shown a response and detects a brightest gray level for each of the R, G, and B of said input video signal in every frame period and converts a gray level of said input video signal so that the detected brightest gray level and a corresponding upper limit gray level become at a same level and, during a lighting period of said backlight, makes said backlight flash at a duty corresponding to a rate of said brightest gray level to the corresponding upper limit gray level.
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Accused Products
Abstract
A liquid crystal display device capable of improving quality of moving images is provided. Each LED (Light Emitting Diode) block is turned ON according to a response of a liquid crystal corresponding to a light emitting region and the brightest gray level is detected for each of red (R), green (G) and blue (B) of an input video signal in every frame period and an input video signal is converted into a value obtained by being multiplied by an upper limit gray level and then by being divided by the brightest gray level and a gray level voltage corresponding to the converted value is applied to each data electrode and, during a lighting period of LED blocks, each LED block is made to flash at a duty corresponding to a rate of the brightest gray level to the upper limit gray level.
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Citations
25 Claims
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1. A liquid crystal display device comprising:
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a liquid crystal display panel; a backlight; and a driving control unit; wherein said liquid crystal display panel displays images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage; wherein said backlight illuminates the liquid crystal display panel from its rear side; and wherein said driving control unit turns off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region and turns on said backlight at a point of time when the liquid crystal has shown a response and detects a brightest gray level for each of the R, G, and B of said input video signal in every frame period and converts a gray level of said input video signal so that the detected brightest gray level and a corresponding upper limit gray level become at a same level and, during a lighting period of said backlight, makes said backlight flash at a duty corresponding to a rate of said brightest gray level to the corresponding upper limit gray level. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A liquid crystal display device comprising:
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a liquid crystal display panel; a backlight; and a driving control unit; wherein said liquid crystal display panel displays images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage; wherein said backlight illuminates the liquid crystal display panel from its rear side; and wherein said driving control unit turns off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region and turns on said backlight at a point of time when the liquid crystal has shown a response and detects an average value of gray levels within a specified range including the brightest gray level for each of the R, G, and B of said input video signal in every frame period in a manner to correspond to each of the light source blocks and converts a gray level of said input video signal so that the detected average value of gray levels and a corresponding upper limit gray level become at a same level and, during a lighting period of said backlight, makes said backlight flash at a duty corresponding to a rate of said average value to the corresponding upper limit gray level. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
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16. A driving control circuit to be used in a liquid crystal display device comprising a liquid crystal display panel to display images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage and a backlight to illuminate the liquid crystal display panel from its rear side, said driving control circuit comprising:
components to turn off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region and to turn on said backlight at a point of time when the liquid crystal has shown a response and to detect a brightest gray level for each of the R, G, and B of said input video signal in the frame period and to convert a gray level of said input video signal so that the detected brightest gray level and a corresponding upper limit gray level become at a same level and, during a lighting period of said backlight, to make said backlight flash at a duty corresponding to a rate of said brightest gray level to the corresponding upper limit gray level. - View Dependent Claims (17, 18)
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19. A driving control circuit to be used in a liquid crystal display device comprising a liquid crystal display panel to display images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage and a backlight to illuminate the liquid crystal display panel from its rear side, said driving control circuit comprising:
components to turn off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region and to turn on said backlight at a point of time when the liquid crystal has shown a response and to detect an average value of gray levels within a specified range including a brightest gray level for each of the R, G, and B of said input video signal in each frame period in a manner to correspond to each of said light source blocks and to convert a gray level of said input video signal so that the detected average value of gray levels and a corresponding upper limit gray levels become at a same level and, during a lighting period of said backlight, to make said backlight flash at a duty corresponding to a rate of said average value to the corresponding upper limit gray level. - View Dependent Claims (20, 21)
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22. A driving method to be used to be used in a liquid crystal display device comprising a liquid crystal display panel to display images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage and a backlight to illuminate the liquid crystal display panel from its rear side, said driving method comprising:
turning off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region, turning on said backlight at a point of time when the liquid crystal has shown a response, detecting a brightest gray level for each of the R, G, and B of said input video signal in the frame period, converting a gray level of said input video signal so that the detected brightest gray level and a corresponding upper limit gray level become at a same level and, during a lighting period of said backlight, making said backlight flash at a duty corresponding to a rate of said brightest gray level to the corresponding upper limit gray level. - View Dependent Claims (23)
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24. A driving method to be used in a liquid crystal display device comprising a liquid crystal display panel to display images corresponding to an input video signal by a driving operation of each of scanning electrodes and each of data electrodes by which a specified gray level voltage is applied to a corresponding pixel region and a response of a liquid crystal is controlled in the pixel region according to the applied gray level voltage and a backlight to illuminate the liquid crystal display panel from its rear side, said driving method comprising:
turning off said backlight during a frame period of said input video signal in which an upper limit gray level for each of red (R), green (G), and blue (B) is set until the liquid crystal shows a response to the application of said specified gray level voltage in said pixel region, turning on said backlight at a point of time when the liquid crystal has shown a response, detecting an average value of gray levels within a specified range including a brightest gray level for each of the R, G, and B of said input video signal in every frame period in a manner to correspond to each of said light source blocks, converting a gray level of said input video signal so that the detected average value of gray levels and a corresponding upper limit gray levels become at a same level and, during a lighting period of said backlight, and making said backlight flash at a duty corresponding to a rate of said average value to the corresponding upper limit gray level. - View Dependent Claims (25)
Specification