Hitachi, Ltd.

Fujitsu Hitachi Plasma Display Limited

Hitachi Maxell, Limited

Hitachi Automotive Engineering Co., Ltd.

Hitachi Video and Information System, Inc.

Hitachi Plasma Patent Licensing Co., Ltd.

Hitachi Plasma Display Limited

Yuichiro Kimura

Yasuji Noguchi

Ken Kumakura

Hideaki Ohki

Takayuki Ooe

Takashi Sasaki

Kuninori Matsumi

Nobuaki Kabuto

Michitaka Ohsawa

Masaji Ishigaki

Satoru Nishimura

Shunji Ohta

Akira Yamamoto

Keizo Suzuki

Yasunobu Hashimoto

Yuji Sano

Masaya Tajima

Satoru Takashimizu

Masanori Takeuchi

Kazuhiro Watanabe

Kenichi Yamamoto

Michitaka Osawa

Nobuo Azuma

Kazuhiro Kaizaki

Hiroshi Ohtaka

Ryuuichi Someya

Sadao Kubota

Mitsuo Okimoto

Yutaka Chiaki

Yoshinori Miyazaki

Hiroyuki Miyajima

Chiharu Ishino

Katsuhiro Masujima

Kenicji Matsumoto

Akito Takemoto

Tadayoshi Oikawa

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.

A high quality, three-electrode type plasma display apparatus, of which the display of low-luminance gradations has been improved by reducing the minimum luminance of the subfield, has been disclosed. In the plasma display apparatus, a subfield of even lower luminance is provided by: providing at least one subfield made up of only a reset period and an address period, without a sustain period, in one frame, and causing an address discharge to occur only between Y (second) electrodes and address (third) electrodes; or providing at least two second subfields made up of only a reset period and an address period in one frame, and making the intensity of an address discharge differ between the two second subfields.

Method of driving plasma display device

A AC type plasma display apparatus has been disclosed, which satisfies various requirements such as the number of gradations that can be displayed, the display luminance, and the upper limit of power and, further, the efficiency of light emission and the luminance can be increased as much as possible and the display quality of which is not deteriorated. In the plasma display apparatus, a frame is composed of plural subfields, an image is displayed by causing a sustain discharge to occur in each subfield, the sustain discharge can be caused to occur by at least a first sustain waveform and a second sustain waveform different from the first sustain waveform, and the ratio of the first sustain waveform to the second sustain waveform changes, both waveforms being used to cause the sustain discharge to occur in each subfield.

Plasma display apparatus

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

In a conventional image display apparatus, since display load ratios for respective lines are different, voltage drop amounts are also different and a difference in brightness occurs in spite of giving the same inputted luminance signal, so that image quality of display image is degraded. In the case where signals at the same luminance level are inputted and displayed, for a pixel on a display panel, an ON pattern of a subfield in one field is changed when a line load ratio of a line including the pixel is changed. That is, an image display apparatus using a display panel having a plurality of pixels is configured so as to include, for each of the plurality of pixels connected to one driving electrode, a load calculating means that calculates the load ratio and a luminance correcting means that calculates a drop amount in luminance level of an inputted video signal for correction.

Image display apparatus and driving method thereof

A signal processor for multiple gradations for carrying out coding by replacing an input image signal with a plurality of subfields, comprising a main path for generating a primary color signal having a first number of gradations, a sub-path for generating a primary color signal having a second number of gradations, which is smaller than the first number of gradations, a switch, a movement detection circuit, a level detection circuit, a path switching control circuit for switching the switch based on the amount of movement and the level, plural subfield coding circuits for carrying out subfield coding different from each another, a superposing circuit for selecting one of the outputs of the plural subfield coding circuits, and a superposing control circuit, and thus preventing a moving false contour.

Signal processor for multiple gradations

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 plasma display device is capable of controlling the brightness of the entire image on a screen over a wide range without impairing a predetermined number of display gradations determined by the dynamic range of an A/D converter, an analogue input circuit and the like. For this purpose, the plasma display device is provided with means for changing the discharge condition (number of discharge pulses, discharge voltage, discharge voltage waveform and the like) during priming discharging, which is effected for initialization, in accordance with the brightness control to control the brightness of light emission during image display.

Plasma display device and driving method

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

An image correction device includes a memory (70) for storing correction data, an address generator (15,31) for supplying addresses to the memory, a regulation pattern generator (40), a DA converter (71) for converting an output of the memory into an analog signal, convergence yoke (CY) coils (74), CY drive amplifiers (73) for converting the analog signal into current for driving the CY coils, a CPU (20) for controlling operation of the image correction device, deflection current detection circuits (10,11) for reading vertical and horizontal deflection currents in the CPU and a memory (60) for storing correction data and deflection currents.

Digital image correction device

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Kawasaki, Japan

Yuichiro Kimura