Abstract: A liquid crystal display device is provided which improves quality of images made up of moving images and images having moving images and still images in a mixed manner. Each frame of an input video signal having a specified frame frequency (60 Hz) is divided into four sub-frames each having a frequency being four times as large as the specified frame frequency and, after an overdriving operation is performed in the first sub-frame on each pixel region of a liquid crystal display panel, a normal driving operation is performed in the second sub-frame and thereafter, and in which a backlight flashes two times at a frequency being two times as large as a frame frequency (120 Hz) of the first frame frequency during one frame period in specified time intervals.

Abstract: There is provided a light emission control circuit being capable of simplifying a power source circuit reducing costs and power consumption. A constant current circuit is serially connected to a specified light emitting device group out of a plurality of light emitting device groups and a power source circuit supplies power to each light emitting device group and a current detecting unit detects a current flowing through a specified light emitting device group and a power control unit controls a power source circuit based on a pre-set current value and on a detected value.

Abstract: There is provided a method of driving a backlight of a liquid crystal display device capable of eliminating leakage of light from adjacently-placed light emitting blocks. A gray level and maximum gray level of an input video signal are inputted for every light-emitting block. An output average gray level is calculated and a lighting control signal corresponding to converted luminance is outputted. The drivers responding to the lighting control signal makes LEDs (Light Emitting Diodes) emit light. An average gray level from an output from sensors is calculated. An average gray level, based on an average gray level and a light leakage rate, by taking light leakage into consideration. A gray level correcting signal is outputted in the light-emitting block based on the above output average gray level. An output average gray level is corrected in response to a gray level correcting signal.

Abstract: There is provided a method of driving a backlight of a liquid crystal display device capable of eliminating leakage of light from adjacently-placed light emitting blocks. A gray level and maximum gray level of an input video signal are inputted for every light-emitting block. An output average gray level is calculated and a lighting control signal corresponding to converted luminance is outputted. The drivers responding to the lighting control signal makes LEDs (Light Emitting Diodes) emit light. An average gray level from an output from sensors is calculated. An average gray level, based on an average gray level and a light leakage rate, by taking light leakage into consideration. A gray level correcting signal is outputted in the light-emitting block based on the above output average gray level. An output average gray level is corrected in response to a gray level correcting signal.

Abstract: There is provided a method of driving a backlight of a liquid crystal display device capable of eliminating leakage of light from adjacently-placed light emitting blocks. A gray level and maximum gray level of an input video signal are inputted for every light-emitting block. An output average gray level is calculated and a lighting control signal corresponding to converted luminance is outputted. The drivers responding to the lighting control signal makes LEDs (Light Emitting Diodes) emit light. An average gray level from an output from sensors is calculated. An average gray level, based on an average gray level and a light leakage rate, by taking light leakage into consideration. A gray level correcting signal is outputted in the light-emitting block based on the above output average gray level. An output average gray level is corrected in response to a gray level correcting signal.

Abstract: An active-matrix bistable display panel is provided in which a pixel electrode is formed at each intersection of each of a plurality of scanning lines in a row direction and each of a plurality of signal lines in a column direction and a display state is made to occur depending on a voltage of each of the pixel electrodes, a signal-line driving unit is provided in which the plurality of signal lines is connected to a plurality of terminals and image inputs are sequentially divided into a plurality of image inputs and a plurality of image signals are supplied sequentially to the plurality of terminals in a time-division manner, and a scanning-line driving unit is provided in which each scanning line making up the plurality of groups is sequentially driven for each of the groups, wherein each of TFTs (Thin Film Transistors) is made active so as to supply an image voltage to each of pixel electrodes.

Abstract: An active-matrix bistable display panel is provided in which a pixel electrode is formed at each intersection of each of a plurality of scanning lines in a row direction and each of a plurality of signal lines in a column direction and a display state is made to occur depending on a voltage of each of the pixel electrodes, a signal-line driving unit is provided in which the plurality of signal lines is connected to a plurality of terminals and image inputs are sequentially divided into a plurality of image inputs and a plurality of image signals are supplied sequentially to the plurality of terminals in a time-division manner, and a scanning-line driving unit is provided in which each scanning line making up the plurality of groups is sequentially driven for each of the groups, wherein each of TFTs (Thin Film Transistors) is made active so as to supply an image voltage to each of pixel electrodes.

Abstract: An active-matrix bistable display panel is provided in which a pixel electrode is formed at each intersection of each of a plurality of scanning lines in a row direction and each of a plurality of signal lines in a column direction and a display state is made to occur depending on a voltage of each of the pixel electrodes, a signal-line driving unit is provided in which the plurality of signal lines is connected to a plurality of terminals and image inputs are sequentially divided into a plurality of image inputs and a plurality of image signals are supplied sequentially to the plurality of terminals in a time-division manner, and a scanning-line driving unit is provided in which each scanning line making up the plurality of groups is sequentially driven for each of the groups, wherein each of TFTs (Thin Film Transistors) is made active so as to supply an image voltage to each of pixel electrodes.

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.

Abstract: A liquid crystal display device is provided which is capable of preventing flicker or fringes in a display screen occurring even when changes in frequencies of a vertical sync signal and horizontal sync signal contained in a video signal input to the liquid crystal display device occur. A frequency detecting circuit sets a frequency of a driving pulse voltage at a value in the vicinity of “positive integer+½” times of the frequency of the horizontal sync signal and a pulse frequency for PWM (Pulse Width Modulation) light control at a value in the vicinity of a positive integral multiple or “positive integer+½” times of the vertical sync signal and a resonant frequency at a value in the vicinity of the frequency of the driving pulse voltage by adjusting capacitance value of a resonant capacitor.

Abstract: There is provided a method of driving a backlight of a liquid crystal display device capable of eliminating leakage of light from adjacently-placed light emitting blocks. A gray level and maximum gray level of an input video signal are inputted for every light-emitting block. An output average gray level is calculated and a lighting control signal corresponding to converted luminance is outputted. The drivers responding to the lighting control signal makes LEDs (Light Emitting Diodes) emit light. An average gray level from an output from sensors is calculated. An average gray level, based on an average gray level and a light leakage rate, by taking light leakage into consideration. A gray level correcting signal is outputted in the light-emitting block based on the above output average gray level. An output average gray level is corrected in response to a gray level correcting signal.

Abstract: There is provided a light emission control circuit being capable of simplifying a power source circuit reducing costs and power consumption. A constant current circuit is serially connected to a specified light emitting device group out of a plurality of light emitting device groups and a power source circuit supplies power to each light emitting device group and a current detecting unit detects a current flowing through a specified light emitting device group and a power control unit controls a power source circuit based on a pre-set current value and on a detected value.

Abstract: A cold cathode tube lighting device is provided which is capable of achieving stable luminance when driven by applying driving pulses to input terminals on both sides of each of two or more cold cathode tubes. Each of currents flowing through coils in each of coil units on both sides of each of two or more cold cathode tubes is detected by voltage detecting sections and a tube current flowing through each of the cold cathode tubes based on a value obtained by adding each of the currents using an adder and a duty ratio of each of driving pulses is controlled so that the tube current becomes a specified current value to keep the luminance of the cold cathode tubes constant.

Abstract: A video display method can lower visibility of flicker in video display and maintain constant display luminance, wherein a display period and a non-display period for a video signal being displayed are provided in one frame period. The method includes frame period controlling by varying the frame period in terms of a single frame or multiple frames as a unit, and display period controlling by varying only the display period or both the display period and the non-display period in the above one frame period depending on variations in the frame period (FIG. 1).

Abstract: A cold cathode tube lighting device is provided which is capable of obtaining stable luminance when a cold cathode tube is driven by applying voltages to input terminals on both ends of the cold cathode tube. A first current flowing through each of transformer secondary sides of transformers is detected by a tube current detecting circuit from a low-voltage side of each of the transformer secondary sides and a second current flowing through each of resonance capacitors is detected by the tube current detecting circuit and a difference between the first current and the second current is calculated for every separately-excited inverter and, based on the difference, a tube current of the cold cathode tube is obtained and frequencies of driving pulse voltages are changed by a voltage controlling oscillator for setting so that the tube current maintains a predetermined value.

Abstract: A separately-excited inverter circuit includes: an oscillator which generates a high-frequency voltage pulse by mixing a high-frequency voltage pulse of a first frequency and a high-frequency voltage pulse of a second frequency different from the first frequency; and a transformer drive part which buffers an output signal of this oscillator, and inputs the signal to a primary side of a transformer. The inverter circuit includes a capacitor which is connected in parallel with an output of a secondary side of the transformer. When used for lighting the backlight of a liquid crystal display, the present invention can improve the lighting characteristics of the backlight with a long cold-cathode tube.

Abstract: A liquid crystal display device is provided which improves quality of images made up of moving images and images having moving images and still images in a mixed manner. Each frame of an input video signal having a specified frame frequency (60 Hz) is divided into four sub-frames each having a frequency being four times as large as the specified frame frequency and, after an overdriving operation is performed in the first sub-frame on each pixel region of a liquid crystal display panel, a normal driving operation is performed in the second sub-frame and thereafter, and in which a backlight flashes two times at a frequency being two times as large as a frame frequency (120 Hz) of the first frame frequency during one frame period in specified time intervals.

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.

Abstract: A liquid crystal display is provided which is capable of improving a quality of a displayed image made up of a moving image and a static image in a mixed manner. By arranging backlights and by dividing one frame of a video input signal into four frame blocks and by getting a moving image detecting circuit to judge whether an image for each of the frame blocks is a moving image or a static image and having a lighting timing duty control section get the backlight corresponding to an image for the frame block having been judged to be a moving image to flash and also get the backlight corresponding to an image for the frame block having been judged to be a static image to be turned ON all the time, occurrence in an image retention phenomenon or a blur of an edge is reduced when a moving image is to be displayed and occurrence of a flicker is eliminated when a static image is to be displayed, which enables improvements in a quality of a displayed image.

Abstract: A flat lighting source is provided which is capable of applying illuminating light to an entire display region of a display panel. A current or voltage is supplied from each LED (Light Emitting Diode) driving/correcting circuit to each LED. Part of light emitted from each of the LEDs is converted into electrical signals and a resistance value of each photodiode decreases in proportion to luminance. If luminance of light emitted from each of the LEDs increases, a resistance value of each of the photodiodes decreases while the luminance of light emitted from each of the LEDs decreases. The resistance value is fed back to each of the LED driving/correcting circuits which changes a driving current or a driving voltage so that luminance of light emitted from each of the LEDs corresponds to a luminance setting voltage. The photodiode is mounted in a one-to-one relationship for every LED.