Mitsumi Electric Company Ltd.

Yoshihiro Okuyama

Hisateru Komatsu

Koichi Seno

Hisamichi Sekine

Masahiro Ishikawa

Osamu Kojima

A laser diode driver for driving laser light sources of a N-wavelength optical pickup capable of recording on and playing N types of optical discs by using N laser beams having different wavelengths, the N-wavelength optical pickup including first to N-th laser diodes for emitting first to N-th laser beams as the laser light sources and one front monitor for monitoring intensity of the first to N-th laser beams, the laser diode driver comprising a current/voltage conversion amplifier for converting a monitor current monitored by the front monitor into a monitor voltage and outputting the monitor voltage as a monitor output signal, wherein N is an integer which is two or more.

Laser diode driver and N-wavelength optical pickup including the same

A flexible printed wiring board (29-1) is brought into contact with an insulating tape (31-1) attached onto an internal wall of an upper case (30) with the movement of a head carriage (25). The flexible printed wiring board (29-1) is coated with an antistatic agent (50) to prevent occurrence of static electricity resulting from frictional contact between the flexible printed wiring board (29-1) and the insulating tape (31-1).

Magnetic disk driver capable of preventing occurrence of a data error

A control circuit adapted to control a motor includes a first circuit part for generating an excitation current to be supplied to the motor and having a predetermined period that is dependent on a predetermined rotation period of the motor, and a second circuit part for superimposing on the excitation current pulses having a period that is small compared to the predetermined period of the excitation current.

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Yamagata, Japan

Yoshihiro Okuyama