Hitachi, Ltd.

Fujitsu Hitachi Plasma Display Limited

Hitachi Maxell, Limited

Yasuji Noguchi

Yuichiro Kimura

Hideaki Ohki

Ken Kumakura

Takayuki Ooe

Kuninori Matsumi

Michitaka Ohsawa

Makoto Onozawa

Masaji Ishigaki

Masanori Takeuchi

Ayahito Kojima

Kazuhiro Kaizaki

Hiroshi Ohtaka

Sadao Kubota

Mitsuo Okimoto

Yutaka Chiaki

Shunji Oota

Chiharu Ishino

Kenicji Matsumoto

Akito Takemoto

A display method of a plasma display apparatus to which primary color video signals are inputted and which carries out color display by letting phosphors for primary colors emit light is provided. The display method displays the primary color video signals by changing a gray level of an output primary color video signal in accordance with a gray level of an input primary color video signal. When each gray level of the inputted primary color video signals changes from a first value to a second value which is larger than the first value, a gray level of a primary color video signal for a phosphor having the largest influence of luminance saturation properties among the phosphors is increased relative to a gray level of the other primary color video signal.

Display method of plasma display apparatus and plasma display apparatus

White balance correction circuit and correction method for display apparatus that displays color image by controlling number of emissions or intensity thereof in accordance with plurality of primary color video signals

A display apparatus, which displays a color image by controlling the number of emissions or the intensity thereof in accordance with primary color video signals input thereto, has a detection portion and a white balance correction portion. The detection portion is used to detect the number of emissions or the intensity, and the white balance correction portion is used to correct white balance by adjusting the amplitudes of the primary color video signals in accordance with the detected number of emissions or the detected intensity. Therefore, correct white balance can be maintained regardless of the number of emissions or the intensity of emission.

White balance correction circuit and correction method for display apparatus that display color image by controlling number of emissions or intensity thereof in accordance with plurality of primary color video signals

A plasma display apparatus, in which the display quality of a dark image is improved and which uses a subfield method, has been disclosed. The plasma display apparatus comprises a plasma display panel, a sustain pulse cycle changing means for detecting the display load ratio of each subfield and changing the sustain pulse cycle of each subfield according to the display load ratio, and an adaptive subfield number changing means for calculating a vacant time in a display frame generated by changing the sustain pulse cycle, judging whether a subfield can be added according to the vacant time, and determining the number of subfields in the display frame.

Plasma display apparatus

A display device that can prevent the thermal destruction and screen burn-in caused by display patterns has been disclosed. In this device, the display luminance is determined by the number of light emissions, and there are provided a sustain frequency control section that controls the sustain frequency, a load ratio calculation section that calculates the load ratio for each frame of display data, plural counters, a load ratio counter control section that controls so as to increase the counts of the counters corresponding to the load ratio level calculated by the load ratio calculation section, and a first judgment section that outputs a first control signal when any of the counts exceeds a first reference value, wherein the sustain frequency control section decreases the sustain frequency according to the first control signal.

Display device

A display apparatus and display method are provided for a display panel having pixels arranged in a matrix form for displaying an image on a effective display area. Horizontal electrodes and vertical electrodes in the display panel are scanned for selectively illuminating said pixels by using a time sharing drive method in which one field period is divided into plural sub-fields weighted according to a sustaining period. As a result, an effective display area is divided into plural areas, no scanning for selecting a light emitting pixel is executed in a non-display area, and the number of sub-fields is increased in an area in which display in multiple gradations is required in a display area to obtain sufficient gradation. Instead of increasing the number of the sub-fields, the total sustaining period per one field is increased to obtain sufficient brightness. According to a feature of the invention, another area is provided in which the number of sub-fields is limited to the required minimum in which display in multiple gradations is not required. According to other feature of the invention, another area having few sub-fields is prepared instead of providing the non-display area.

Display apparatus and display method thereof

A plurality of photo detectors are arranged outside the display screen of a projection display apparatus having a built-in digital convergence correction system and a function for adjusting data in the frame memory so as to coincide the photoelectric devices of the photo detectors with the adjustment patterns is provided. The adjusted data when the convergence on the entire screen of the display is adjusted and the adjusted data when the convergence is adjusted by the adjustment function before misconvergence is generated are memorized beforehand. When misconvergence is generated, the convergence is adjusted by the adjustment function again, and a corresponding correction value is obtained on the photo detector by calculating the adjusted data at this time and the prememorized adjusted data, and a correction value on the entire screen is obtained by executing an interpolation calculation from this correction value, and the misconvergence on the entire screen is corrected.

Convergence correction system with recovery function and display

A digital convergence correction system and a method of preparing a convergence correction data used for an image display unit, including at least one cathode ray tube, are disclosed. Correction data at correction points at predetermined between adjusting points providing representative correction points are determined by interpolation. A whole section subjected to correction is segmented into a plurality of sub-sections. An interpolating function for each sub-section is an independent low-order function. The values of the interpolating functions for adjacent sub-sections sandwiching a boundary, i.e., an adjusting point, the values of the first order derivatives and the values of the second order derivatives, respectively, are rendered to be equal to each other at such adjusting point.

Digital convergence correction system and method for preparing

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Kawasaki, Japan

Yasuji Noguchi