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: A picture tube drive apparatus for driving a color picture tube. The picture tube drive apparatus comprises a video output circuit which receives video signals, amplifies them and outputs the amplified video signals, a picture tube drive circuit which receives the video signals amplified by the video output circuit for driving said color picture tube based on video signals, the picture tube drive circuit having a detector for detecting a beam current corresponding to the brightness of each color flowing through the picture tube, a picture tube connected with the picture tube drive circuit for displaying the video signals, a white balance control circuit into which a detection value of a beam current detected by the picture tube drive circuit is inputted and for outputting video signal level compensation signals for adjusting the white balance of the video image displayed on the picture tube to the picture tube drive circuit.

Abstract: A system for generating magnetic fields to converge a plurality of electron beams in a cathode-ray tube including at least one convergence yoke having a core with a ring-shaped outer periphery and a plurality of magnetic poles on an inner periphery thereof extending toward a neck part of the cathode-ray tube for forming magnetic paths therewith.

Abstract: A convergence system for a cathode-ray tube having three detection magnetic pole pieces are disposed opposing to each other on both sides of a center beam for forming magnetic paths inside the neck part of a cathode-ray tube. A first convergence yoke is disposed outside the neck part of the cathode-ray tube for forming magnetic paths together with the magnetic pole pieces. A first coil is wound on a first convergence yoke to generate a magnetic field for correcting horizontal misconvergence between the center beam and a side beam on a side of the center beam. A second coil is wound on the first convergence yoke to generate a magnetic field for correcting horizontal misconvergence between the center beam and a side beam on the other side of the center beam. A third coil is wound on the first convergence yoke to generate a magnetic field for correcting vertical misconvergence between the center beam and both side beams.

Abstract: A ring magnetic sub-core having a plurality of protrusions inside is disposed adjacent to an electron gun side of a main magnetic core on which a horizontal deflection coil and a vertical deflection coil are wound, and an auxiliary vertical deflection coil connected with said vertical deflection coil is wound around said magnetic sub-core, thereby making it possible to have both improvement of convergence performance and reduction of barrel distortion be consistent with each other. Further, a convergence coil is wound around said magnetic sub-core so as to correct a transverse raster or a longitudinal raster.

Abstract: The digital convergence correction device is used for a projection-type television receiver having a Braun tube with an aspherical surface fluorescent screen and a projection lens system with an aspherical surface plastic lens attached to the display screen of th Braun tube. In the digital convergence correction device, a digital memory stores digital correction data corresponding to correction values at the convergence adjustment points on the display screen that is divided in the horizontal and vertical directions. A multiplexer reads the digital correction data out of the digital memory, and implements the time division multiplexing for the data. A D/A converter receives the multiplexed data from the multiplexer, and converts it into an analog signal. The device is provided with sample-holding circuits for making coincident timing for the outputs of the time division multiplexing process, so that no phase shift arises at the time division process and multi-channel time division process is made possible.

Abstract: At least two pairs of auxiliary coils are disposed externally on a deflection yoke at positions which are symmetric with respect to the central axis of a horizontal direction of said deflection yoke and which are separated from each other in the direction of the axis of a cathode ray tube. At least two pairs of auxiliary coils are respectively disposed in front of and at the back of the longitudinal center of a magnetic core. The auxiliary coils have a horizontal length which is longer than its another length. A horizontal deflecting current is supplied to the first pair of auxiliary coils in the direction in which unnecessary radiant magnetic fields generated in front of and at the back of the deflection yoke are suppressed, and a horizontal deflecting current is supplied to the second pair of auxiliary coils in the direction in which an unnecessary radiant magnetic field generated at the back of the deflection yoke is intensified.

Abstract: Disclosed is a display apparatus in which peculiar synchronizing signals fed while being accompanied by a video signal to be displayed are recognized, control signals for instructing picture scene size (display size) and picture display position optimum to the recognized synchronizing signals are generated by a digital automatic tracking circuit or the like, and horizontal and vertical deflection circuits are operated by the thus generated control signals so that a picture scene having optimum picture scene size and optimum display position is displayed on a display screen.

Abstract: A horizontal deflection circuit comprising a horizontal output transistor, and a drive circuit is connected between the base and the emitter of the horizontal output transistor to supply a base drive voltage to the horizontal output transistor in order to control the conduction between the collector and the emitter of the horizonal output transistor, wherein first and second switching means are provided in parallel between the base of the horizontal output transistor and the drive circuit (or between the emitter of the horizontal output transistor and the drive circuit), the first switching means permitting only the current to flow from the base of the horizontal output transistor to the drive circuit (or from the drive circuit to the emitter of the horizontal outut transistor) and the second switching means being conductive only during the conductive period of the horizontal output transistor.

Abstract: A digital convergence correcting device effecting convergence correction by using convergence correcting data stored in a memory which includes an address fixing device which, in the case where convergence correcting data are insufficient, reads out in succession the correcting data corresponding to the last horizontal scanning line for the portion lacking in the data so that the correcting data are used repeatedly, and which, in the case where convergence correcting data are excessive, only necessary convergence correcting data are used.

Abstract: A convergence correcting apparatus is used in a projection television receiver including a CRT having an aspherical fluorescent screen and a projection lens apparatus which is attached to the display screen of the CRT and has aspherical plastic lenses. In the digital convergence correcting apparatus, a digital memory stores digital correction data corresponding to correction values of convergence adjustments points indicative of a plurality of points on the display screens divided in the horizontal and vertical directions. A multiplexer reads out predetermined digital correction data from the digital memory and time sharingly multiplexes. At least one digital/analog converter receives the time sharingly multiplexed data from the multiplexer and generates an analog signal. Sample and hold circuits extract a predetermined correction signal from the analog output of the digital/analog converter and sample and hold them.

Abstract: A driving circuit uses an output transistor and a driving transformer with a secondary coil being connected to the base of the output transistor. In order to get a high speed switching circuit without thermal runaway, the storage period of the output transistor is detected. A signal supplied to a primary coil of the driving transformer, for example, a driving pulse, is controlled in response to the detected value of the storage period. By minimizing the value of the storage period, it becomes possible to minimize a fall time of the output transistor, so that a stability of the driving circuit can be maintained.

Abstract: A high-voltage stabilizing circuit for stabilizing high voltages such as those generated by the fly-back transformer of a television. The stabilizer includes a common-emitter type PNP transistor and an inverse current-absorbing capacitor with a small capacitance in order to provide a high-speed response. The collector of the transistor is connected with the primary coil of the fly-back transformer and the capacitor. The emitter of the transistor is connected with a power source. With this arrangement, even though parabolic wave voltages are generated at the capacitor due to the small capacitance, the PNP transistor hardly cuts off at all and can therefore supply adequate current to the fly-back transformer.