Mitsubishi Denki Kabushiki Kaisha

Nitto-denko Corporation

Mitsubishi Denki Kaisha Kaisha

Hidenori Takita

Tatsuhiro Hirakawa

Seiichi Takaoka

Takashi Inoue

Shinji Nohara

Masatoshi Ochiai

Yoshikazu Terasaki

Akira Kawabata

A color cathode ray tube display device has a cathode ray tube 1, a convergence purity assembly 10 mounted on a neck portion 29 of the tube 1 at a position behind a deflection yoke 8, a two pole coil unit 12 near the convergence purity assembly 10 to form a two pole magnetic field, a purity coil 13 wound around a cathode ray tube panel 3, and current supplying circuits 15 for supplying currents each being in synchronism with a vertical or horizontal deflection current. It further has a distributing device which detects portions of mislanding on the picture plane by the aid of another device and analyzes a result of the detection, and current control circuits 16 for controlling the currents to the two pole coil unit 12 and the purity coil 13 in accordance with an instruction from the distributing device. Mislanding can be corrected by adjusting the currents to the two pole coil unit 12 and the purity coil 13 in addition to adjustment of a ring 103 of the convergence purity assembly 10 and adjustment of a mounted position of the deflection yoke 8. Quantities to be adjusted are indicated by the distributing device, and therefore, an adjusting work for ITC can be easy.

Color cathode ray tube display device and method of adjusting color

A cathode-ray tube includes an envelope in which a panel portion, a funnel portion, and a neck portion are integrally formed, and a conductor film and a deflecting yoke mounted on an outer surface of the funnel portion. A strip-type electric field reducing piece has a coated portion coated with an insulator, and an exposed conductive material portion. The coated portion is disposed between the funnel portion and the deflecting yoke, and the conductive material portion is connected to the conductor film.

Cathode-ray tube and display unit using the cathode-ray tube

A CRT display for producing picture images on a cathode ray tube comprising a bipolar electromagnet located at a neck portion of a cathode ray tube and having field coils to produce a bipolar magnetic field for imparting a corrective horizontal or vertical deflection to an electron beam being deflected by the deflection yoke, upon receiving, from a current supply circuit, a sawtooth current with positive and negative alternations in synchronism with the deflection current of the cathode ray tube. The bipolar electromagnet is adopted to produce a bipolar magnetic field on the basis of an alternating sawtooth current which is supplied to its field coils in synchronism with the deflection current.

CRT display

A color CRT display apparatus in which the polarity and the strength of the external magnetic field in the tube direction of a CRT are detected by a magnet detecting element, and a current corresponding to the strength of the external magnetic field is supplied to a compensating coil which is wound around a funnel portion between a display panel and a deflection yoke and at a place where a purity rotation and a raster rotation by said external magnetic field in said tube direction are simultaneously compensated, thereby both the purity rotation and the raster rotation can be automatically compensated in an optimum state.

Color CRT display apparatus

A magnetic cancelling apparatus for a color cathode-ray tube which is to cancel external magnetic fields acting on the color cathode-ray tube, can prevent deterioration of the screen color purity. The apparatus includes a magnetic sensor for detecting a magnetic field in a predetermined direction acting on the cathode-ray tube. The output of the magnetic sensor is amplified and then fed to a cancelling coil, thereby permitting the screen purity to be kept in best condition even under change in direction of the external magnetic field such as the geomagnetism.

Magnetic cancelling apparatus for color cathode-ray tube

A deflection yoke for a cathode ray tube comprises a generally tubular core, a first deflection coil assembly including a pair of first deflection coils wound on the core and arranged in symmetrical relationship with each other about the longitudinal axis of the core and operable to deflect electron beams, traveling from an electron gun assembly towards a phosphor-coated screen region, in a horizontal direction, and a second deflection coil assembly generally toroidally wound on the core and operable to deflect the electron beams in a vertical direction. A pair of magnetic members are mounted on the core in opposition to each other and positioned on the imaginary horizontal axis perpendicular to the longitudinal axis of the core while spaced 180.degree. from each other about the longitudinal axis of the core. Each of the magnetic members is constituted by a generally elongated body having a pair of legs protruding from the elongated body which legs are spaced from each other in a vertical direction. A magnetizing member for each magnetic member is also provided for developing predetermined poles in the legs of each of the magnetic members.

Growing community of inventors

Nagasaki, Japan

Hidenori Takita