Mitsubishi Denki Kabushiki Kaisha

Japan Metals & Chemicals Co., Ltd.

Nippon Steel Welding Products and Engineering Co., Ltd.

Atsuo Onoda

Keiichi Nishikawa

Yukio Izumi

Hidetada Nagaoka

Yuuji Oomura

Masao Sato

Akira Hashimoto

Yasutaka Mizutani

Kazuo Hasegawa

Masayoshi Kamo

Yoichi Muratomi

Hiroshi Ito

Kazuya Oda

Satoru Akutsu

Shin Isozaki

Masao Kamada

Yuji Ohmura

Katsumi Kurita

Tadanobu Ohke

Mitinaga Suzuki

Kiyotaka Hoshi

Koichi Aoki

Hitoshi Nishimura

Kuniteru Suzuki

Shunji Kikuchi

Hideto Nishimura

Koichi Okubo

An apparatus and formatting method formats a disk without using an index pulse generated by hardware for every disk rotation. A last data block gap and a track gap which are longer than a standard track gap length are first written. Even if there is a fluctuation in rotation cycle time during formatting, a last sector of each track is written over a beginning of the track gap. When writing to a last sector is complete, formatting of a track is complete. When a head is stably positioned at a track to be formatted, formatting of the track is started.

Formatting apparatus and a flexible disk

A head assembly moving along a long side of a magnetic card, more than one magnetic head rotating in the head assembly for reading/writing data, a rotary transformer and a carriage with a card holding mechanism for keeping a card at a predefined position are provided in a card reader of the present invention. A rotating part of the rotary transformer in the head assembly receives and sends a signal to the magnetic head and a fixing part of the rotary transformer is connected to a reading/writing circuit. On the card of the present invention, which is usually rectangular, there are tracks defined by plural arcs. The arcs are on plural same-size circles whose centers are aligned on one line along the long side of the card. A magnetic card or an optical card can be used for the present invention.

Card drive apparatus and card

An object of the present invention is to provide an iron base Si--Mn alloy or an iron base Si--Mn--Ni alloy which can be easily crushed and can be manufactured in large quantity, and alloy powder thereof. An iron base Si--Mn--Ni alloy having good crushability and alloy powder thereof, comprising:

Iron base Si--Mn alloy or iron base Si--Mn--Ni alloy having good

A flexible disk drive unit including a spindle motor for driving to rotate a magnetic disk; magnetic heads opposing the magnetic disk; a carriage attached to a frame and movable in a radius direction of the magnetic disk; wherein the frame and a motor base constitute a common member and the spindle motor is of a sensorless drive system and is directly attached to the frame; and wherein the frame is provided with an attaching hole for erecting a bearing of the spindle motor of the sensorless drive system on the frame.

Frame for flexible disk drive unit having distortion prevention hole and

A brushless motor driving circuit is provided for obtaining a reliable starting and stable rotation driving irrespective of the load condition of the motor. The brushless motor driving circuit has a terminal voltage detector located at each phase of the armature windings of the motor, a terminal voltage compensator for adding or subtracting a compensation value to/from the terminal voltage of the armature windings detected at respective phases during actual driving periods, and a comparator for comparing respective terminal voltages to obtain a rotor location signal after compensation has been performed. The compensation value is determined by a resistor of the armature winding and a winding current. The armature windings are driven by the rotor location signal detected at the comparator.

Drive circuit for brushless motor

Growing community of inventors

Tokyo, Japan

Atsuo Onoda