Teac Corporation

Fumio Nagase

Hiroshi Tsuyuguchi

Shinichi Aikawa

Yoshiaki Sakai

Hidetoshi Kabasawa

Tohru Miura

Katsuya Enami

Jiro Ueki

Kazuhiko Inoue

Kiyoshi Fukuchi

Toru Tanabe

Miya Enami

Sinobu Kawamura

Toshihiro Ogawa

Naoki Sugeta

Shinichiro Tanaka

Takashi Numata

An optical disk drive unit performing write power calibration which performs recording on a given test area of an optical disk by changing a write power and sets an optimum write power based on characteristic values obtained from reproduced signals from the given test area includes average calculation means for dividing the given test area into a plurality of areas, performing recording on the areas by changing the write power equally, and calculating averages of characteristic values obtained from reproduced signals from the areas, and optimum write power setting means for setting the optimum write power based on the averages of the characteristic values calculated by the average calculation means. Thereby, with the averages of the characteristic values obtained from the areas of the optical disk which areas are in angularly different positions, the effects of the periodic variation of the optical disk can be reduced and the optimum write power can be set with good accuracy.

Optical disk drive unit

A miniaturized magnetic head which can reduce running torque of a disk driving motor while head-touch and penetration margin of the magnetic head remain effective. The magnetic head comprises a slider which slides on a flexible magnetic disk, a head core, integrally formed with the slider, to perform recording/reproducing of information on/from the flexible magnetic disk, and a groove, having a width of less than 0.4 mm, formed on a sliding surface of the slider, the groove extending in a tangential direction of the rotation of the flexible magnetic disk and reaching from one end of the slider to the other end of the slider.

Magnetic head

A magnetic head unit has a pair of spaced apart mounting legs bonded to a flexure seat thereby to be resiliently supported. Being made from sheet steel or the like, the flexure seat is more thermally expansible than the head unit. Should the pair of mounting legs be thermally spread apart from each other, the head unit would be strained to such an extent as to fail to make proper data transfer contact with the rotating magnetic disk. In order to avoid this danger, the flexure seat is configured to include a frame portion defining an opening, and a pair of spaced apart insular portions disposed in the opening in the frame portion and independently joined thereto via slender bridge portions. The head unit is mounted to this flexure seat by having the pair of mounting legs thereof bonded one to each insular portion.

Thermally stable magnetic head assembly with magnetic head legs bonded

A flexure seat for gimbaling a magnetic head is fabricated from sheet steel, comprising a central portion to which the head is to be mounted, an intermediate portion of annular shape around the central portion, and an outer portion of semiannular shape around the intermediate portion. The central portion is joined to the intermediate portion via a first pair of bridge portions in a first direction, and the intermediate portion to the outer portion via a second pair of bridge portions aligned in a second direction at right angles with the first direction. In order to suppress the unwanted oscillation, and prevent the resonance, of the central portion, a pair of dampers, as of silicone elastomer, are formed across the spacing between the central and intermediate portions, in positions on both sides of the central portion and in alignment with the second pair of bridge portions. The damper material is applied in fluid form and solidified by exposure to light. Any excessive spreading of the damper material before solidification is prevented by providing a pair of tapering tongues projecting from at least either of the central portion and the intermediate portion toward, and terminating short of, the other.

Magnetic head gimbal seat damped against unwanted oscillation and

A head supporting device includes an arm on which an upper magnetic head of a magnetic disk system is mounted, the arm having an adhesion surface to which a first adhesive agent and a second adhesive agent are applied, a carriage on which a lower magnetic head of the system is mounted, the carriage having an adhesion surface to which the first and second adhesive agents are applied, a first gimbal for connecting the upper magnetic head to an internal circuit of the system, the first gimbal having a first adhesion surface so that the first gimbal along with the upper magnetic head attached thereto is fixed to the arm by the first and second adhesive agents, and a second gimbal for connecting the lower magnetic head to the internal circuit, the second gimbal having a second adhesion surface so that the second gimbal along with the lower magnetic head attached thereto is fixed to the carriage by the first and second adhesive agents. In this head supporting device, the adhesion surface of the arm and the first adhesion surface include diagonally cut grooves so that the first adhesive agent flows in the grooves so as to evenly spread over the adhesion surface of the arm and the first adhesion surface, and the adhesion surface of the carriage and the second adhesion surface include diagonally cut grooves so that the first adhesive agent flows in the grooves so as to evenly spread over the adhesion surface of the carriage and the second adhesion surface.

Head supporting device of magnetic disk system

A disk drive has a pair of transducers mounted to respective planar flexure seats and electrically connected to respective flexible printed circuit boards for data transfer with the opposite sides of a rotating flexible magnetic disk. One of the transducers, mounted to a pivoted load arm on a carriage, is moved away from the other transducer when the disk is being loaded in and unloaded from the disk drive. In order to prevent the conductive pattern on the circuit board for this one transducer from contacting the metal made top wall of the disk drive casing, the circuit board is shaped to include a major portion disposed on the back side of the flexure seat, opposite to the front side on which the transducer is mounted. The circuit board is further provided with a first pair of flaps which extend in opposite directions from the major portion and which are folded onto the front side of the flexure seat, and a second pair of flaps which extend right angularly from the first pair of flaps and which are folded, after having been folded together with the first pair of flaps onto the first side of the flexure seat, back onto the second side thereof so as to cover parts of the conductive pattern on the major portion. The transducer has its leads soldered to the conductive pattern on the first pair of flaps.

Space saving configuration of a printed cirucit board for a magnetic

A dual head type magnetic disk recording/reproducing apparatus, in which a magnetic disk is inserted and/or from which the magnetic disk is ejected, the magnetic disk having a first surface and a second surface each of which is segmented into a plurality of tracks, each track having a corresponding track number, the dual head type magnetic disk recording/reproducing apparatus includes a first magnetic head which reproduces an information signal from a first track on the first surface, a second magnetic head which reproduces an information signal from a second track on the second surface, a track number of the second track corresponding to that of the first track, and a predetermined number of tracks being between the first track and a radial location of the second track, a low pass filter, coupled to the first and second magnetic heads, to which the information signals reproduced by the first and second magnetic heads are supplied, and control means, coupled to the low pass filter, for adjusting a cut-off frequency of the low pass filter so that a resolution of the information signal reproduced at the first track and that of the information signal reproduced at the second track can be approximately equal to each other.

Dual head type magnetic disc recording/reproducing apparatus

A disk drive has a pair of transducers mounted to respective planar flexure seats for data transfer with the opposite sides of a rotating flexible magnetic disk. The transducers have their leads electrically connected to flexible printed circuit boards generally disposed on the back sides of the flexure seats, opposite to the front sides on which the transducers are mounted. Since the soldering of the transducer leads to the circuit boards on the back sides of the flexure seats, which has been the case heretofore, makes it difficult to reduce the thickness of the disk drive to an absolute minimum, each circuit board is shaped to include a pair of end portions extending through openings in one associated flexure seat and disposed on the front side of the flexure seat. The transducer leads are soldered to the end portions of the circuit boards on the front sides of the flexure seats.

Connection of transducer leads to a printed circuit board in rotating

A data transfer system of the type including a disk drive for selective use with flexible magnetic disk cartridges of first and second storage capacities (e.g. 1 MB and 4 MB), the first storage capacity being less than the second storage capacity, a host computer, and a controller for controlling the operation of the disk drive under the direction of the host computer. The controller is factory preprogrammed to discriminate between unformatted disk cartridges of the two different storage capacities as either of the two types of disk cartridges is loaded in the disk drive. The program is such that, in response to the first of a series of formatting commands at the first storage capacity from the host computer, the controller causes the disk drive to write track format for the second storage capacity on a preassigned track (e.g. inmost track) on the disk and then immediately to read the track format. If the retrieved track format contains errors, it follows that the loaded disk cartridge is of the first storage capacity. Accordingly, the controller proceeds to format the disk cartridge at the first storage capacity. If the retrieved track format does not contain errors, on the other hand, then the loaded disk cartridge is of the second storage capacity. Thereupon the controller signals the host computer to that effect.

Method and apparatus for discriminating between unformatted magnetic

The miniature magnetic head according to the present invention has a bulk type magnetic head core, one side surface of which is fixed on a slider and the other side of which is exposed. The magnetic head can be made smaller than the conventional magnetic head in which both sides of the magnetic head core are respectively fixed on two sliders.

A disk storage in which a first dimension in which a disk is inserted/ejected a disk is approximately orthogonal to a second dimension in which a head seeks. A housing which accommodates a disk has an opening portion via which a head seeks a desired track on the disk. The opening portion is aligned in the second dimension. Since the head moves in the second dimension, it is not necessary to provide a space in the first dimension for moving the head. Therefore, the disk storage according to the present invention can be made thinner in the first dimension than the conventional disk storage in which the head moves through the opening portion in the first dimension.

Disk storage in which direction of inserting disk is approximately

A dual head type magnetic disk according/reproducing apparatus, in which a magnetic disk is inserted and/or from which the magnetic disk is ejected, the magnetic disk having a first surface and a second surface each of which is segmented into a plurality of tracks, each track having a corresponding track number, the dual head type magnetic disk recording/reproducing apparatus includes a first magnetic head which reproduces an information signal from a first track on the first surface, a second magnetic head which reproduces an information signal from a second track on the second surface, a track number of the second track corresponding to that of the first track, and a predetermined number of tracks being between the first track and a radial location of the second track, a low pass filter, coupled to the first and second magnetic heads, to which the information signals reproduced by the first and second magnetic heads are supplied, and control means, coupled to the low pass filter, for adjusting a cut-off frequency of the low pass filter so that a resolution of the information signal reproduced at the first track and that of the information signal reproduced at the second track can be approximately equal to each other.

Dual head type magnetic disk recording/reproducing apparatus

An assembling position-adjusting mechanism of a magnetic disk apparatus able to adjust the azimuth, radial alignment, and index of a magnetic head by adjusting a position thereof during the assembling process of a spindle motor. A positioning head movable in a direction perpendicular to a top surface of a table is provided. A plurality of positioning pins are provided on the bottom of the positioning head. Moving mechanisms are provided in the positioning head so that the bottom surface of the positioning head is movable and rotatable parallel to the top surface of the table. Each positioning pin of the positioning head is inserted into a respective positioning hole of a motor assembly so as to move the motor assembly with a movement of the positioning head so that the spindle motor of the motor assembly is at an appropriate position relative to the magnetic head of the main body of the magnetic disk apparatus.

Assembling position adjusting mechanism of a spindle motor for a

Magnetic head carriage

A magnetic disk drive is disclosed which has a tunnel erase head assembly comprising a read/write head for writing and reading data on a magnetic disk, and a pair of tunnel erase heads for trimming a pair of opposite marginal edges of the record track being formed by the read/write head, with the consequent formation of spaces intervening between the record tracks. The spaces created on the same disk by different disk drives may be of one polarity of magnetization or the other, with the possibility of noise production due to an abrupt change in the polarity of magnetization as the read/write head scans any of the spaces as a result of mistracking. For the reduction of such noise the coil of the tunnel erase heads is connected to an erase current source via a circuit whereby the erase current is made to have a staircase or ramp rise and fall.

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Tama, Japan

Fumio Nagase