Hitachi, Ltd.

Hitachi Media Electronics Co., Ltd.

Kazuyoshi Takizawa

Kiyoshi Watanuki

Kazuo Kato

Takashi Sase

Hideyuki Mochida

Tomohiko Douken

Kikuo Tomita

Yoshihiko Sugawara

Shuzo Oshima

Muneo Chiba

A display monitor which comprises a flyback transformer for supplying a high voltage to a display and an opposite-phase pulse inducing transformer. The flyback transformer includes a core, a primary-side low-voltage coil wound on the core, a secondary-side high-voltage coil wound on the core and divided into high-voltage coil pieces, rectifier diodes connected in series with respective output sides of the high-voltage coil pieces of the secondary-side high-voltage coil so as to form a series circuit, and a high-voltage capacitor connected to a cathode of one of the high-voltage rectifier diodes in a final stage of the series circuit. The opposite-phase pulse inducing transformer is constituted by a core different from the core of the flyback transformer, an opposite-phase pulse inducing coil wound on the different core for inducing a pulse which is opposite in phase to a deflecting yoke driving horizontal pulse, and a different-core high-voltage output line provided on the different core, the opposite-phase pulse inducing transformer being arranged so that the pulse opposite in phase to the deflecting yoke driving horizontal pulse is superimposed on the different-core high-voltage output line.

Display monitor

An electrostrictive revolution type ultrasonic motor includes a piezoelectric ceramic disk shaped stator and a rotor. The piezoelectric ceramic disk shaped stator has an eccentric movement via excitation by two phase pulse like voltage. The rotor is fitted around the circumference of the stator and is transmitted by a rotating torque due to the eccentric movement via frictional contact therebetween. The rotor is formed of a plastic material by injection molding to achieve a reduction of a size variation of the rotor and a stable contact with the stator. A high and stable rotating torque is thereby obtained with a reduced production cost. Further, a driving device for the ultrasonic motor which varies the frequency of a voltage applied to the ultrasonic motor in a stepped manner discriminates the magnitude of the corresponding motor currents and drives the ultrasonic motor with the frequency which causes the maximum motor current. In this manner, a simple structured and low cost driving device which operates at a high speed and at a high resolution with a high efficiency is achieved.

Ultrasonic motor and driving for the ultrasonic motor

A stacked or laminated-layer type of flyback transformer includes a plurality of high voltage windings wound in regular order in a direction of the winding axis and arranged on the same core cylinder. The high voltage windings in the respective layers are connected in series with each other by diodes and so that a voltage is generated with a direction of stacking of these windings. A winding start position of the first layer high voltage winding nearest a primary winding is lagged with respect to the winding start positions of the second layer winding and subsequent layer winding. The winding start position of the first layer winding is selected to be the position of, for example, 0 to 25% when the winding width on the core cylinder is 100%.

Display device including flyback transformer constructed to control

In a high voltage generator comprising a flyback transformer having a primary winding and a secondary winding, a horizontal deflection circuit connected to the primary winding of the flyback transformer, and a rectifier diode connected to the secondary winding of the flyback transformer, a resonance circuit including a saturable transformer and a capacitor is inserted between the primary winding of the flyback transformer and a power source, and a signal corresponding to the value of a high voltage load current is applied to a control winding of the saturable transformer. When the value of the high voltage load current is very small, the resonance circuit resonates with a higher harmonic of a flyback pulse to remove this higher harmonic component. As the value of the high voltage load current increases, the inductance value of the secondary winding of the saturable transformer changes to change the resonance frequency of the resonance circuit. As a result, the proportion of removal of the higher harmonic component decreases to increase the peak value of the high voltage thereby suppressing a voltage drop of the high voltage.

High voltage generator

Growing community of inventors

Hiratsuka, Japan

Kazuyoshi Takizawa