Abstract: It is possible to better correct dynamic false contours in gradation display made by dividing each field into plural subfields. A motion vector detection section detects a motion vector extending between pixels mutually corresponding between two mutually neighboring fields. A pixel position changing section calculates a pixel position vector indicating from where to acquire data for use in rearranging emission data by multiplying a motion vector ending at a pixel to be rearranged by a predetermined function. Furthermore, when a brightness difference between the pixel from which data is to be acquired and the pixel to be rearranged is larger than a threshold value, the pixel position changing section corrects the calculated pixel position vector to change the pixel indicated thereby to one closer to the pixel to be rearranged until the brightness difference is equal to or smaller than the threshold value.

Abstract: An image display apparatus, which converts a video signal in a first video signal format into a video signal in a second video signal format causing an increase in dynamic range, and displays the video signal in the second video format, includes a video signal conversion circuit configured to receive the video signal in the first video signal format and to produce the video signal in the second video signal format, a drive circuit configured to drive an image display panel according to the video signal in the second video signal format, and a signal processing module including signal processing circuits configured to perform signal processing necessary to drive the drive circuit, wherein the video signal conversion circuit is situated inside the signal processing module.

Abstract: 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.

Abstract: A display apparatus displaying gray scale by using a subfield method has a gain control circuit, a sub gain control circuit, and an error diffusion circuit. The gain control circuit has the number of gray scale levels of an input signal and outputting a first intermediate image signal with a first number of gray scale levels, and the sub gain control circuit receives the first intermediate image signal, compresses the number of gray scale levels of the first intermediate image signal, and outputs a second intermediate image signal with a second number of gray scale levels. The error diffusion circuit receives the second intermediate image signal and increase the number of gray scale levels by simulating additional gray scale levels through error diffusion.

Abstract: A multi-grayscale display device to appropriately control brightness of a display (screen) and power according to the content of a picture while preventing deterioration of image quality of a picture, so that both of these performances are improved. In a multi-grayscale processing unit of the display device (PDP device), in a subfield (SF) driving control, the number of pixels of low grayscales in an image of an input picture signal is detected and determined by an image number detection unit, and accordingly, a selection signal to switch one from outputs of a plural types of SF conversions of an SF conversion unit is determined and outputted by a switching unit. In the control, an SF conversion in which the number of rest SF becomes large as the number of pixels of low grayscales becomes small selected.

Abstract: A technology capable of reducing false contours and others in accordance with inclinations of various gradations and capable of improving image quality when moving images are displayed in a multiple tone display system is provided. In this display system, in addition to a movement amount (MV) and a digit change signal (RK) and the like, an edge amount (GR) which expresses a size of inclination of gradation is detected in a multiple tone processing unit. Then, in accordance with them, an appropriate process is selected and executed in a false contour processing unit from plural kinds of processes for reducing the false contours in moving images including a multiple tone process.

Abstract: A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.

Abstract: An image display apparatus divides one field into plural weighted subfields and combines the plural subfields to perform a multi-gray-scale image display on a display panel. The image display apparatus includes a motion amount detecting circuit 50, a diffusion amount calculating circuit 52, and a diffusion circuit 53. The motion amount detecting circuit 50 detects a motion amount from a current field and a field before the current field based on an input image signal. The diffusion amount calculating circuit 52 calculates a diffusion amount to diffuse false contour noise to the surrounding, based on a gray scale of the input image signal and the detected motion amount. The diffusion circuit 53 performs a diffuse process in the calculated diffusion amount. With this arrangement, it is possible to improve the image quality of a moving-image display, by decreasing a false contour, without generating additional noise and without increasing the circuit scale.

Abstract: An image display apparatus includes a displayed-subfield selecting circuit configured to select a lit-up pattern table from a plurality of lit-up pattern tables in response to an input image signal, a gain-characteristic generating circuit configured to select, from a plurality of gain characteristics, a gain characteristic corresponding to the selected lit-up pattern table, and a gain control circuit configured to produce a gain-limited image signal made by limiting a maximum level of the input image signal in response to the selected gain characteristic, wherein the on/off state of subfields is controlled in response to a level of the gain-limited image signal in accordance with the selected lit-up pattern table, thereby displaying a multi-level image on a display panel.

Abstract: A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.

Abstract: 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.

Abstract: In a display method of a PDP apparatus or the like, there is provided a technique for reducing or eliminating dynamic false contours in a display video image by determining and detecting an occurrence region of dynamic false contours in display data with good accuracy for coping. In a false-contour detection unit in a PDP apparatus, a carry detection unit detects, as a dynamic-false-contour occurrence region, a pixel region corresponding to carry in an SF on-cell pattern of adjacent pixels based on a video image signal in view of a predetermined condition. In a width control unit, a detection region is expanded according to a motion amount. A detection region is expanded according to a motion amount in a width control unit. A diffusion processing (actual gray-scale number restriction processing) based on dither or error diffusion is performed to the detection region.

Abstract: 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.

Abstract: An image display apparatus, which displays an image in multiple grayscales on a display panel by combining a plurality of weighted subfields into which one field has been divided, has an SF usage rate detection circuit, a display SF selection circuit, an SF conversion circuit, and a driving control circuit. The SF conversion circuit selects one of a plurality of prestored light emission pattern tables and outputs an encoded subfield data by encoding an input image signal in accordance with a selected light emission pattern table. The driving control circuit receives an output of the SF conversion circuit, and drives the display panel in accordance with a prescribed driving sequence.

Abstract: A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.

Abstract: 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 for detecting the amount of movement from the change in primary color signal between the current field and the preceding field, a level detection circuit for detecting the level indicating the tendency for a moving image false contour to occur, 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 cont

Abstract: A display apparatus displaying gray scale by using a subfield method has a gain control circuit, a sub gain control circuit, and an error diffusion circuit. The gain control circuit has the number of gray scale levels of an input signal and outputting a first intermediate image signal with a first number of gray scale levels, and the sub gain control circuit receives the first intermediate image signal, compresses the number of gray scale levels of the first intermediate image signal, and outputs a second intermediate image signal with a second number of gray scale levels. The error diffusion circuit receives the second intermediate image signal and increase the number of gray scale levels by simulating additional gray scale levels through error diffusion.

Abstract: An optical film of an optical filter portion as a component of a gas discharge display device has an absorption region for selectively absorbing a light between 550 nm of wavelength and 620 nm of wavelength. A transmittance of an absorption peak within the absorption region is within a range of 20% to 60% of an average transmittance in a visible light region.

Abstract: A display apparatus enables analog clock display with, for example, twelve numbers 1 to 12 and a pair of long and short hands. In the display apparatus, a control circuit produces instruction data for controlling an on-screen display circuit which generates color signals for displaying an analog clock image. The instruction data causes the on-screen display circuit to change the colors of the two numbers to which the long and short hands point in the analog clock image so that these two numbers are displayed in a different color from those of other ten numbers.