Kabushiki Kaisha Suwa Seikosha

Seiko Epson Kabushiki Kaisha

Shin Shibata

Kikuo Oguchi

Akihiro Gomi

Misuo Oguchi

Akira Aoyama

Sumio Gomi

Tetsuya Mino

A floppy disk drive system for double-sided recording and playback having first and second heads positioned to hold a disk therebetween is provided. The first and second heads each have a read/write gap and each have a contacting plane for contacting the disk. Each such contacting plane has an inner edge position toward the center of the disk and an outer edge positioned toward the outer circumference of the disk. The gap of the first head is closer to the outer circumference of the disk than the gap of the second head when the heads are assembled in facing relation. The distance between the center of the inner edge of the contacting plane of the first head and the center of the read/write gap of the second head is about 0.6 mm or less. The contacting plane of the second head may be larger than that of the first head, said enlargement being in the direction of the inner circumference of the disk. At least one of the heads may have the two inner corners thereof chamfered by about C 0.5 or more and the corresponding corners of the contacting plane may be smoothly rounded. The contacting plane of the first head may be larger than that of the second head, said enlargement being in the direction of the outer circumference of the disk.

Floppy disk drive system with improved record/playback heads

A magnetic head for perpendicular magnetization recording especially suitable for operation from only one side of a magnetic tape includes a central magnetic pole surrounded in spaced relationship by a peripheral magnetic pole. An exciting coil is wound around the central magnetic pole for maintaining the central and peripheral magnetic pole at different magnetic potentials. Both magnetic poles are located on the same side of a multi-layer magnetic recording medium to be magnetized by the recording head.

Magnetic head for perpendicular magnetization recording

A flexural mode tuning fork quartz crystal vibrator having two vibrator tines including first and second opposed substantially planar surfaces, the thickness of the plate between said opposed surfaces being no greater than 0.2 mm is provided. Both surfaces of each tine have three electrodes on at least the lengthwise peripheral sides of the respective surfaces of the tines and a third electrode intermediate and not in contact with the two peripherally disposed electrodes with each intermediate electrode being short-circuited to the peripheral electrode on the other tine. A fourth electrode is disposed on at least one lengthwise side edge of both of the respective tines, the fourth electrode electrically coupling the peripherally disposed electrode on the lengthwise peripheral sides of the respective surfaces of the tine.

Quartz crystal vibrator

A flexural mode tuning fork quartz crystal vibrator having two vibrator tines including first and second opposed substantially planar surfaces, the thickness of the plate between said opposed surfaces being no greater than 0.2 mm is provided. Both surfaces of each tine have three electrodes photo-etched on at least the lengthwise peripheral sides of the respective surfaces of the tines and a third electrode photo-etched intermediate and not in contact with the two peripherally disposed electrodes with each intermediate electrode being short-circuited to the peripheral electrode on the other tine. A fourth electrode is disposed on at least one lengthwise side edge of both of the respective tines, the fourth electrode electrically coupling the peripherally disposed electrode on the lengthwise peripheral sides of the respective surfaces of the tine.

Quartz crystal tuning fork with three electrodes on each major tine face

A mounting adapted to support and provide a two-terminal connection to a flexural mode quartz crystal vibrator having two opposed surfaces with two electrodes disposed on at least one of the opposed surfaces is provided. The mounting includes a non-conductive member having first and second spaced apart conductive surfaces, the non-conductive member having a lesser thermal coefficient of expansion than the quartz crystal vibrator. At least one metallic plate is disposed between one of the conductive surfaces and the quartz crystal vibrator for coupling an electrode to a conductive surface, the metallic plate having a thermal coefficient of expansion less than the quartz crystal vibrator and the mounting member.

Growing community of inventors

Suwa, Japan

Shin Shibata