Nec Display Solutions, Ltd.

Nec Viewtechnology, Ltd.

Reiichi Kobayashi

Michio Kobayashi

Hiroaki Ikeda

Shigenobu Jyou

Takeshi Morimoto

Eifu Nezu

The present invention is aimed at appropriately suppressing display failure such as a tailing phenomenon and the like in a normally white type liquid crystal panel. A driver () supplies a drive voltage in conformity with an image signal received by an image signal processing circuit (), to a liquid crystal panel (). A histogram detector () detects a histogram representing the relationship between the signal level of the image signal received by the image signal processing circuit () and the number of pixels. A CPU () calculates, based on the histogram detected by the histogram detector (), a first proportion of the number of pixels (on the white side) whose signal level is equal to or greater than a first defined value, to the total number of pixels of the histogram and a second proportion of the number of pixels (on the black side) whose signal level is equal to or smaller than a second defined value that is smaller than the first defined value, to the total number of pixels of the histogram. An amplifier () corrects the lower limit of the drive voltage that the driver () supplies to the liquid crystal panel () in accordance with the first proportion of white side pixels and second proportion of black side pixels calculated by CPU ().

Image display apparatus and image correction method

An image display apparatus includes: a panel () that includes a plurality of picture elements that change transmittance of light according to picture levels; a detection unit () that detects, in one-image portions of the panel (), picture levels for each of the plurality of picture elements from picture signals that indicate the picture levels of each picture element; and a processor () that, based on the picture levels of one-image portions that were detected by the detection unit (), adjusts the transmittance of light of the plurality of picture elements such that the image realized by the picture signal is brighter when a value that corresponds to brightness is greater than a predetermined threshold value.

Image display apparatus, picture signal processing method, and program

A method of improving an image quality of a video signal, which is supplied on a frame-by-frame basis, includes extracting low frequency components from a video signal of an n-th frame, where n is a natural number excluding zero, subtracting the extracted low frequency components from a video signal of an (n+m)th frame to produce high frequency components, where no is a natural number excluding zero, and adding the produced high frequency components to the video signal of the (n+m)th frame. The extracted low frequency components include a horizontal component and a vertical component.

Method and apparatus for improving image quality

An object of the present invention is to realize a transmission distortion correction system for allowing an image signal including a plurality of picture signals to be corrected, and to realize an image signal transmitter and an image display unit. The image display unit of the present invention includes: a second reference signal generation means for generating a second reference signal similar to a first reference signal regarding the image signal in which the first reference signal is inserted into each of the plurality of picture signals by the image signal transmitter; a plurality of waveform equalizers provided that correspond to the plurality of picture signals and that include a filter circuit capable of setting a characteristic thereto; and a control portion for inputting the plurality of picture signals, analyzing a characteristic of a transmission path between the image signal transmitter and the image display unit upon detecting the first reference signal in the input picture signals by comparing the first reference signal with the second reference signal, and setting a characteristic inverse to the analyzed transmission path characteristic to a filter circuit of the waveform equalizers that correspond to the input picture signals.

Image display system, image signal transmitter and image display unit

A liquid crystal display device includes a liquid crystal panel including a plurality of liquid crystal cells, a common voltage generation circuit that supplies a common voltage to the liquid crystal panel, a liquid crystal drive circuit that implements control for supplying the plurality of liquid crystal cells with voltage that accords with a video signal to display an image on the liquid crystal panel, and for reversing a polarity of the voltage supplied to the plurality of liquid crystal cells, and an adjustment module that stores characteristics data for correcting fluctuations in brightness and, based on the characteristics data, adjusts the brightness of the image displayed on the liquid crystal panel.

Liquid crystal display device and liquid crystal panel drive method

An average value signal of the G two-phase input signal is generated by means of an average value calculation circuit. This average value signal is regarded as a signal in which a one-dimensional low-pass filter process, in which the number of taps is 2 and the filter coefficient for each tap is 0.5, has been carried out for a single-phase signal and the number of items of data then thinned to one half. A two-dimensional LPF circuit next subjects this average value signal to a low-pass filter process to eliminate the high-frequency component (edge component). The average value signal that has undergone the low-pass filter process is then subtracted from the input signal of each phase to extract the edge component of the input signal of each phase. An amplification circuit then multiplies the edge component of the input signal of each phase by a prescribed factor, and an addition circuit next adds this multiplied edge component to the input signal of each phase. The above-described processes emphasize the edges of a video picture that is realized by a two-phase signal and thus realize flare correction.

Picture quality improvement device and picture quality improvement method

A picture quality improving apparatus which is low in cost and small in circuit scale has a vertical low-pass filter (LPF) for extracting a vertical low-frequency component from an input luminance signal, a horizontal LPF for extracting a horizontal low-frequency component from the output signal from the vertical LPF, a subtractor for subtracting the output signal from the horizontal LPF from the luminance signal which has been compensated for the delay, a gain adjusting circuit for adjusting the gain of an edge signal produced by the subtractor, and an adder for adding the edge signal whose gain has been adjusted to the delay-compensated luminance signal. Each of the vertical LPF and the horizontal LPF comprises an FIR (finite impulse response) filter and an IIR (infinite impulse response) filter which are connected in cascade or parallel to each other.

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Tokyo, Japan

Reiichi Kobayashi