Hitachi, Ltd.

Hitachi Video and Information Systems, Inc.

Makoto Kitamura

Toshimitsu Watanabe

Takeshi Mochizuki

Masahisa Tsukahara

Takaaki Matono

Toshihiko Matsuzawa

Koichi Sudo

Yasuhiro Kasahara

Yasuhiro Tomita

Kouichi Sugimoto

Fumiyoshi Akiyama

Takayuki Tanaka

A raster distortion correction and deflection circuit arrangement includes a deflection coil adapted to be mounted on a cathode ray tube, a horizontal deflection coil driving circuit for passing a current of saw-tooth waveform of a horizontal deflection period through a horizontal deflection coil constituting the deflection coil, a flyback transformer the primary winding of which is connected between a power supply and an output terminal of the horizontal deflection coil driving circuit, an S-correction capacitor connected in series with the horizontal deflection coil, and an anode voltage detection circuit for detecting variations in an anode voltage of the cathode ray tube which is a secondary winding output of the flyback transformer. A raster distortion correction current based on an output voltage of the anode voltage detection circuit is injected into a connection point of the horizontal deflection coil and the S-correction capacitor. A signal from a signal detection circuit for ABL connected to the flyback transformer can be employed together with an output of the anode voltage detection circuit or in substitution for it for generating the raster distortion correction current.

Raster distortion correction and deflection circuit arrangement

A display device for suppressing focus dislocation due to high voltage fluctuation and realizing a dynamic focus circuit with large output at low power consumption and low cost, in which a circuit for detecting high voltage fluctuation is provided, and the dynamic focus waveform is clamped, and the waveform of horizontal cycle is clipped during the retrace time, and a boot strap circuit including an emitter follower, DC feedback circuit, and capacitor is provided as an output circuit.

Display device with dynamic focus circuit

The present invention aims at providing an image display apparatus capable of displaying both a television signal and an image signal supplied from a personal computer with a high picture quality on a high definition display unit having 1024 by 768 pixels. In order to achieve this object, an image display apparatus according to the present invention includes an NTSC-VGA conversion circuit for converting a television signal to a signal having 640 by 480 pixels and corresponding to the non-interlacing VGA standard, a switch unit for selecting and outputting either the signal outputted from the NTSC-VGA conversion circuit and an inputted image signal from a personal computer, and a VGA-XGA conversion circuit for converting a number of pixels of a signal outputted from the switch unit to a number of pixels 1024 by 768 substantially equivalent to the number of the display unit.

Image display apparatus capable of displaying personal computer signals

A projection display apparatus having three projection tubes for the projection of images of different primary colors wherein the images from the projection tubes are projected on an enlarged scale onto a screen through projection lenses. The display apparatus includes a first deflection unit having at least a first deflection coil mounted on a neck portion of a first projection tube, a second deflection unit having at least a second deflection coil mounted on a neck portion of a second projection tube and a third deflection unit having at least a third deflection coil mounted on a neck portion of a third projection tube. According to a feature of the display apparatus, a first linearity correction coil is coupled in series with a parallel connection of the second deflection unit and only one of the first and third deflection units.

Projection display apparatus

Growing community of inventors

Yokohama, Japan

Makoto Kitamura