Abstract: 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.

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: 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: 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: 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.

Abstract: 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.

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 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.

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 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.

Abstract: 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.

Abstract: 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.

Abstract: An elevator door system including a landing door, a car door provided on a car, a latch device for locking the landing door when the landing door is closed. The elevator door system also includes a door locking device provided on the landing door composed of a coupling plate for coupling with the car door, an unlocking plate provided in parallel with the coupling plate, and a link for moving the unlocking plate toward the coupling plate. The elevator door system further includes a first linking mechanism for linking the door locking device with the latch device, and a coupling device provided on the car door composed of a pair of coupling rollers for coupling the car door with the landing door. One of the coupling rollers pushes the unlocking plate toward the coupling plate when the car lands the landing floor. A displacement of the unlocking plate caused by being pushed toward the coupling plate by the link is applied to the latch device.

Abstract: 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.

Abstract: 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.

Abstract: Double line sequential scanning is performed on a display apparatus which displays, for example, a television signal and a character and graphics signal. When only a television signal is to be displayed, priority is given to the resolution of the image. When a character an graphics signal is to be displayed superimposed on the television signal, double line sequential non-interlace scanning is performed by force. In this manner, the problem of sticking or ghosting of the character and graphic images is reduced.

Abstract: In parallel to a first current source for discharging (or charging) a capacitive load in a complementary way with respect to a voltage output circuit, a second current source for compensating a voltage change caused by leak resistance is provided. Since the voltage change of the capacitive load caused by the leak resistance is not so large, the amount of a current let flow by the second current source provided for compensating the voltage change of the capacitive load caused by the leak resistance may be made smaller than the amount of a current let flow by the first current source. By providing the second current source, therefore, it becomes possible to compensate the voltage change of the capacitive load caused by leak resistance while limiting an increase in dissipated power to a very small value.

Abstract: A brightness control circuit for a color display tube comprises voltage regulating means for varying a voltage between an input terminal and an output terminal thereof in dependence on an externally supplied voltage control signal are provided between cathodes of a color display tube corresponding to primary color signals and an output end of the color display tube drive circuit for supplying drive currents to the individual cathodes of the color display tube, and voltage control signal generating means connected to the voltage regulating means for supplying the voltage control or adjusting signals to the voltage regulating means. The voltage control signal generating means include two regulating means, i.e. first regulating means for changing simultaneously all the voltage control signals supplied to the voltage regulating means corresponding to the primary color signals and second regulating means for varying individually the voltage control signals for each of the color signals.