Matsushita Electric Industrial Co., Ltd.

Hitachi Global Storage Technologies Netherlands B.v.

Satoshi Noguchi

Hiroshi Matsuda

Kenji Kuroki

Mutsuro Ohta

Hiroki Kitahori

Keishi Takahashi

Hitoshi Tamura

Takaya Kitao

A magnetic circuit is provided in an enclosure that can efficiently generate magnetic flux from the enclosure, configuring a magnetic disk, to a magnetic disk. Thus, by providing such a magnetic circuit, a magnetic field different from that in other enclosure parts, that is, a local magnetic field, is generated from the magnetic circuit in case the disk device is set in an external magnetic field. Hence, this local magnetic field can effectively erase data in the magnetic disk. In particular, since the local magnetic field is generated even if the external magnetic field is weak, it is possible to not only suppress the demagnetization of permanent magnets used in the spindle motor at minimum, but also effectively erase data in the magnetic disk.

Disk device and data-erasing method

A time sound generating device which generates a time announcement sound by detecting a change of time from a portion of a display element driving signal supplied to a time display element of a digital electronic clock and by driving an audio sound signal source by the detected time signal.

Time sound generating device

Provided in a video amplifier circuit in accordance with the present invention is a first switching element which receives input video signals and makes a switching action, a second switching element which receives input dual intensity signals for shifting the intensity level of selected parts of the images, and a video signal amplifying stage. Also provided is a variable voltage feeding circuit, a power supply terminal, a transistor connected by its collector substantially to said power supply terminal and by its emitter to an output terminal of said first switching element and to an input terminal of said video signal amplifier stage, a diode connected between a variable voltage output terminal of said variable voltage feeding circuit and the base of said transistor in the direction backward to that of the base current of said transistor and a base resistor connected to said base to feed the base current of said transistor whereby the display intensity of the accentuated brighter characters is made free from adjustment setting of the display intensity of the non-accentuated characters and the highest display intensity of the non-accentuated characters is made the same as that of the accentuated characters.

Cathode-ray tube display apparatus

Growing community of inventors

Fujisawa, Japan

Satoshi Noguchi