Hitachi, Ltd.

Hitachi Metals, Ltd.

Yasuji Kamata

Kazuo Kato

Kenkichi Yamashita

Hideo Sato

Jushi Ide

Ryushi Shimokawa

Seiichi Ueda

Akira Ikegami

Hiroshi Kuwahara

Koji Takahashi

Hideo Arima

Hiroshi Kuwabara

Hiromi Tosaki

Masahiko Fukui

Kazuo Katou

Herein disclosed are an amplifier and a display which uses the former. The amplifier includes a current amplifying circuit for sending out an amplified output current varying according to an input signal, and a current-voltage converting circuit for converting the output current of the current amplifying circuit into a voltage thereby to generate a high output voltage in response to the input signal. The supply voltage V.sub.cc1 of the current amplifying means and the supply voltage V.sub.cc2 of the current-voltage converting means are set separately of each other to have a relationship of V.sub.cc1 &lt;V.sub.cc2. Thus, a high output voltage can be obtained from the current-voltage converting circuit without the need for the current amplifying means to have high breakdown voltage elements.

Amplifier and display using the former

Herein disclosed is a variable gain amplifying circuit which comprises a heating element, a heat-sensitive resistance coupled thermally to the heating element, an amplifier including the heat-sensitive resistance, and means for controlling the heat of the heat element. This heat of the heating element is controlled so as to control the value of the heat-sensitive resistance. As a result that the value of the heat-sensitive resistance is controlled, the gain of that amplifier is controlled.

Variable-gain amplifying circuit

A CRT picture display apparatus of the raster scan type comprises a cathode ray tube for raster scanning, a horizontal deflection circuit for supplying a horizontal deflection current to a horizontal deflection coil of the CRT, a vertical deflection circuit for supplying a vertical deflection current to a vertical deflection coil of the CRT, and a display data generator for supplying data to be displayed to the CRT. The horizontal deflection circuit produces as the horizontal deflection current a triangular current having one period which is twice a horizontal scanning period, and the triangular current has a first portion which increases in response to a horizontal sync signal at a predetermined inclination and a second portion which decreases in response to the next horizontal sync signal at the predetermined inclination and continues until the further next horizontal sync signal, whereby the period for a scanning line to proceed from lefthand end to righthand end of a raster on a screen of the CRT is made substantially equal to the period for the next scanning line to proceed from righthand end to lefthand end, and data is displayed during both the periods.

CRT picture display apparatus

Disclosed herein is a critical temperature sensitive resistor material which comprises 60 to 90% by weight of VO.sub.2 and 40 to 10% by weight of RuO.sub.2. This material exhibits hysteresis of resistance that decreases remarkably over a temperature range in which the resistance varies greatly, and is hence used for measuring the temperature maintaining a high precision.

Critical temperature sensitive resistor material

An improved apparatus for driving a cathode-ray tube (CRT) with minimized power consumption is disclosed. In the apparatus, a voltage regulator element (a Zener diode) supplying a regulated voltage substantially equal to that voltage of the associated cathode providing a maximum image luminance is connected in series with the cathode between the driving circuit and the cathode, thereby reducing the driving voltage of the driving power source and reducing the power consumption of the CRT driving apparatus.

Cathode-ray tube driving apparatus

In a convergence distortion correction method and apparatus for raster-scanned color CRT having a dynamic convergence magnet assembly, the CRT display screen is divided into a plurality of zones. A digital memory is provided with a data storage field and a flag bit field at each address. Addresses of the zones are generated by means of a sync signal regenerated from an input video signal. First, the addresses of zones to be subjected to the adjustment of convergence distortion are selected to set flags in the flag bit fields of the digital memory at its addresses specified by the selected zone addresses. Then, by referring to the flags, guide patterns are displayed on the selected zones and are used to adjust the convergence distortions in those zones. Preferably, one of the displayed guide patterns is flickered. Correction data based on the results of the adjustment are stored in the data storage fields of the digital memory at the corresponding addresses. Correction data for zones other than the selected zones may be interpolated from the correction data for the selected zones.

Convergence distortion correction method and apparatus for color

An inductor having a coil member commonly wound on a couple of closed magnetic circuits made of a soft magnetic material. A magnetic gap is provided at a part of the soft magnetic material of at least one of the two closed magnetic circuits, and a permanent magnet providing a magnetic bias is inserted in the magnetic gap. This inductor is used in series between a DC power source providing a superimposed current of a DC current and an AC current and a load. The inductance of the inductor is very large with respect to a small DC current, while it reduces sharply when the applied DC current increases to be a certain value to show a substantially constant low value with respect to a DC current value beyond the certain value.

Inductor

A DC-to-DC converter for providing a DC output voltage proportional to a DC voltage applied to the primary winding of a transformer by turning on and off the applied DC voltage by means of a switching element connected in series with the primary winding. The voltage developed across the secondary winding of the transformer upon the turning on and off of the applied DC voltage is rectified and smoothed by means of a circuit including a rectifying diode, a choke coil and a capacitor. The transformer has a core which exhibits a rectangular hysteresis characteristic. When the switching element is turned off, the current flowing through the choke coil when the switching element is conductive is caused to flow as a reset current through a part of the secondary winding of the transformer so that the level of the magnetic flux of the core of the transformer may be restored to its initial value.

DC-to-DC converter

A DC amplifier circuit with transformer coupled isolation comprises a DC amplifier, an electronic switching element connected to the output terminal of the DC amplifier, a pulse generator for driving the electronic switching element, a small pulse transformer having a primary winding and secondary winding. To the primary winding of the small transformer pulsating signals from the electronic switching element are applied, and two substantially identical circuits each having a diode and a condenser in series are connected respectively across the primary winding and the secondary winding of the small pulse transformer. Means for feeding back the smoothed signals from the circuit across the primary winding of the small pulse transformer is connected to a negative input terminal of the DC amplifier.

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Hitachi, Japan

Yasuji Kamata