Matsushita Electric Industrial Co., Ltd.

Tomoko Morita

Mitsuhiro Kasahara

Yuichi Ishikawa

Hideaki Kawamura

Tomoaki Daigi

Hideto Nakahigashi

Toshio Wakahara

Naoji Okumura

Takao Wakitani

Yuji Sekiguchi

Masahiro Tani

Makoto Kawachi

Yasuaki Muto

Tadayuki Masumori

Akio Niwa

Takuma Higashi

Akira Yawata

A first video signal generation circuit newly generates pixels between pixels in a first progressive video field signal outputted by a first progressive video generation circuit, and outputs a third progressive video field signal. A second video signal generation circuit newly generates pixels between pixels in a second progressive video field signal outputted by a second progressive video generation circuit, and outputs a fourth progressive video field signal. A comparison circuit compares the third progressive video field signal and the fourth progressive video field signal, and outputs the result of the comparison as motion amount information. An output circuit synthesizes an intra-field interpolation signal and a frame interfiled interpolation signal on the basis of the motion amount information, and outputs a composite signal as a progressive video signal.

Image conversion device and image conversion method

A plurality of interlaced video signals respectively corresponding to a plurality of continuous fields are generated by first, second, and third one-field delay circuits on the basis of an inputted interlaced video signal. A first progressive video field signal is generated by a first progressive video generation circuit on the basis of the plurality of interlaced video signals. A second progressive video field signal is generated by a second progressive video generation circuit on the basis of the plurality of interlaced video signals. Motion amount information in the vertical direction of a picture is calculated by a comparison circuit on the basis of the first progressive video field signal and the second progressive video field signal.

A temperature difference estimated value is found from a video signal using a temperature estimated value representing the temperature of the panel outer periphery of a display screen of a PDP and a reference value representing the temperature of the panel outer periphery of the PDP which is outputted from a panel periphery temperature setter by a temperature difference estimator, and the luminance of an image displayed on a display is controlled depending on the temperature difference estimated value by a controller and a brightness controller.

Display device and luminance control method therefor

Display device and method of controlling its brightness

A gray level conversion/diffusion circuit diffuses the difference between a non-display gray level and a display gray level by error diffusion processing when a video signal is a video signal of the non-display gray level, a video signal-sub-field corresponder converts a video signal of one field after diffusion to a video signal every sub-field, and a sub-field processor, a scanning and sustain driving circuits and a data driving circuit make a discharge cell of a plasma display panel emit light or emit no light every sub-field in response to the video signal every sub-field.

Display device, and display method

The invention provides an apparatus and a method applied to a plasma display panel or other display panel, achieving a gray scale display by using a plurality of weighted subfields. The apparatus comprises a gray scale limiting/difference diffusion circuit () for converting gray scale levels in a supplied image signal to specific gray scale levels that do not easily create pseudo contours in moving picture areas and to intermediate gray scale levels between the specific gray scale levels, and diffusing the difference between the converted gray scale level and the original gray scale level to adjacent pixels, and a dither circuit () for generating a video signal to display the converted gray scale level from the circuit () alternately in even and odd fields. The dither circuit () generates the video signal in which the gray scale levels offset the dither level above and below the dithered gray scale are alternately presented when the converted gray scale level is a dithered gray scale.

Apparatus and method for making a gray scale display with subframes

Video data of a field necessary for I/P conversion and scanning line conversion is stored in a field memory part (), vertical frequency conversion is performed by a memory control processing part (), I/P conversion is performed by an I/P conversion processing part (), scanning line conversion is performed by a scanning line conversion part () and horizontal pixel conversion is performed by a horizontal pixel conversion processing part () with the data stored in the field memory part, and a synchronous processing part () supplies a prescribed clock, a horizontal synchronizing signal and a vertical synchronizing signal to each block. A single system performs vertical frequency conversion, I/P conversion, scanning line conversion and horizontal pixel conversion.

Video signal conversion device and video signal conversion method

A pseudo-contour noise detecting device for detecting pseudo-contour noise is provided. The pseudo-contour noise is embodied as contour lines appearing spuriously in a motion picture displayed such that a gradation display is performed by using a plurality of weighted subfields into which one field of an input image, including a plurality of pixels, is divided. The device includes a pseudo-contour noise calculating unit in which, a logic operation is performed, for each subfield, on each pixel of at least a portion of the input image using a value of the each pixel and values of at least one of the pixels surrounding the each pixel. Further, a value corresponding to an amount of pseudo-contour noise is calculated according to a number of subfields in which a difference is detected between the value of the each pixel and the values of the at least one of the pixels surrounding the each pixel.

Detector for detecting pseudo-contour noise and display apparatus using the detector

A display apparatus creates, for each image, a number of subfields Z from a first subfield to a Zth subfield in accordance with a Z bit representation of each pixel, a weighing value for each subfield, and a number of gradation display points. The display apparatus detects a peak image brightness level and an average image brightness level. A weighing multiple including a positive integer part and a fractional part is determined based on the peak image brightness level and the average image brightness level. The weighing multiple is multiplied by the weighing value of each subfield to obtain a product capable of having a positive integer part and a fractional part. An integer value near the product is defined as a number of drive pulses for each subfield. The weighing multiple is increased as the average image brightness level decreases and as the peak image brightness level increases.

PDP display drive pulse controller

The display device of the present invention is provided with a means (8) for setting the writing pulse width of the attentional light-emitting sub-field wider than the normal writing pulse width at all the gray scale levels in the case where at least two continuous non-light-emitting sub-fields possibly exist before the attentional light-emitting sub-field at a certain gray scale level among all the gray scale levels specified on the basis of the number Z of sub-fields and the weighting of the sub-fields. According to the display device of the present invention, the discharge for writing can be stably executed without reducing the number of sub-fields in one field.

Plasma panel display device

A drive pulse controller creates a driving signal for a display device that produces a gradation display. Each field of an input image signal is divided into a plurality of Z weighted subfields. The drive pulse controller determines a number of subfields Z for each field of the input image signal, changes the input image signal into a Z-bit brightness signal, specifies a number of sustain pulses for each subfield within a field, creates a driving signal for each field based on the Z-bit brightness signal and the number of sustain pulses, selects one of light emission time data stored in a time data source based on the determined Z, and calculates a delay time based on the selected light emission time data, such that the most-weighted subfields of consecutive fields having different numbers of subfields Z are positioned substantially at the same time.

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Hirakata, Japan

Tomoko Morita