Teac Corporation

Shinichi Aikawa

Fumio Nagase

Yoshiaki Sakai

Hiroshi Tsuyuguchi

Katsuya Enami

Sinobu Kawamura

Hiroshi Matsunaga

Jun Makabe

Hiroshi Shibuya

Akira Nishimoto

Tohru Hayashi

Hideya Kato

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

A compatible disk drive is disclosed which is capable of writing and reading data on either of first, second and third interchangeable flexible magnetic disk cartridges of different storage capacities at first, second and third prescribed data transfer rates, respectively. The first and second disk cartridges have a first and a second capacity discriminate window, respectively, formed in different prescribed positions in their housings by way of contradistinction from each other and from the third disk cartridge which has no capacity discriminate window. The disk drive customarily employs two disk sensors for discriminating among the first, second and third disk cartridges. The invention ultilizes the binary outputs from the two disk sensors for the detection of the loading of any of the three types of disk cartridges, thereby dispensing with an additional sensor heretofore employed for that purpose.

Compatible data storage apparatus for use with disk assemblies of two or

A magnetic head assembly comprises a base defined with a flat slide surface on which a magnetic disk is contacted and a magnetic core embedded on the base surface so as to form a flush surface on the slide surface. The slide surface extends in a direction of rotation of the magnetic disk for a length B and has a width A in which the ration B/A is chosen equal to or larger than 4. The length B is set so as to satisfy a relation 0.35 m.ltoreq.B.ltoreq.0.55 m, where m is the length of an access opening in the housing for the disk in the rotational direction of the disk. At the same time, the slide surface is finished with such a precision that the slide surface shows a specular gloss. With such a magnetic head, the vibration of magnetic head assembly associated with rotation of the magnetic disk is successfully suppressed.

Magnetic head assembly

A magnetic disc apparatus comprises a single write/read magnetic head for carrying out write/read with respect to either one of a low-density magnetic disc and a high-density magnetic disc, and a cosine equalizer supplied with a read signal from the write/read magnetic head. The write/read magnetic head has a core gap length which is between 0.60 and 1.20 times a minimum field conversion length for high-density write by a write/read signal.

Magnetic disc apparatus with a cosine equalizer and specific gap length

A magnetic recording and/or reproducing apparatus comprises a first magnetic head mounted on a carriage and a second magnetic head mounted on an arm which swings to and from the carriage, for engagement with a first and second side respectively of a flexible magnetic disc. The first and second magnetic heads are mounted on the carriage and the arm respectively via first and second gimbal plates. The elastic modules of the first gimbal plate is chosen such that the resonance of the first and second magnetic heads due to external vibration is avoided.

Magnetic recording and/or reproducing apparatus having a head support

A disk drive capable of data transfer with a magnetic disk at, say, 192 tracks per inch (tpi) is made compatible with a 96 tpi disk drive. The 192 tpi disk drive comprises a magnetic head assembly having both a read/write head and a pair of tunnel erase heads. During writing at 192 tpi the tunnel erase heads are held out of operation, making it possible for the read/write head to form data tracks at the high density required. The tunnel erase heads are automatically switched on and held in operation during writing at 96 tpi, for erasing the edge portions of each data track being created by the read/write head. Thus, even if the disk on which data is to be written at 96 tpi bears old data tracks that have been prerecorded by a 96 tpi disk drive, such old data tracks will be completely erased by the pair of tunnel erase heads as the 192 tpi disk drive rewrites thereon at 96 tpi. So rewritten, the disk can be read by either the 192 or 96 pti disk drive.

Magnetic disk apparatus capable of writing at two different track

An apparatus having a pair of magnetic transducer head assemblies for data transfer with both sides of a recording medium such as a flexible magnetic disk. One of the head assemblies is mounted via a planar flexure seat on a carriage movable radially of the medium, whereas the other head assembly is mounted via another planar flexure seat on a load arm which is hingedly mounted on the carriage for pivotal motion toward and away from the medium. At least one, preferably both, of the head assemblies has a data transfer coil such as a read/write coil at least partly, preferably wholly, disposed on that side of the flexure seat which is directed toward the recording medium. An erase coil, if any, of each head assembly may also be disposed on the same side of the flexure seat. This coil arrangement affords a significant reduction in the thickness of the apparatus.

Magnetic data transfer apparatus having improved transducer coil

An apparatus having a pair of magnetic transducer head assemblies for data transfer contact with the opposite faces of a flexible magnetic disk. One of the head assemblies has its disk engaging surface disposed at an angle to the normal plane of the magnetic disk in order to hold the disk engaging surfaces of both head assemblies in proper data transfer contact with the magnetic disk in spite of its wobbling movements during rotation. The disk engaging surface of that one head assembly slants away from the normal disk plane in a direction that can be anywhere between a radially inward direction of the magnetic disk and a tangential direction of a notional circle drawn concentrically on the magnetic disk, the tangential direction being upstream of the magnetic disk with respect to its predetermined direction of rotation. As the other head assembly is gimbaled and sprung against the slanting head assembly via the intervening magnetic disk, both head assemblies can be held in proper data transfer engagement with the disk despite its undulations in both radial and tangential directions.

Head assemblies mounted for optimum contact with a flexible magnetic disk

A flexible magnetic disk drive is disclosed which has a transducer head requiring little or no positional or angular readjustment for proper data transfer contact with a flexible magnetic disk in the face of possible dimensional or mounting errors. The transducer head has a rounded contact surface for data transfer contact with the flexible magnetic disk, in which surface is defined a transducing gap, typically a read/write gap. The transducing gap is offset toward the axis of the magnetic disc from a notional line right angularly crossing, at the apex of the contact surface, another notional line connecting the apex of the contact surface and the center of the magnetic disk. So positioned on the contact surface, the transducing gap is practically free from the wobbling motion of that part of the rotating magnetic disk which is radially outward of its points of contact with the transducer head and with a pressure pad. The transducing gap can be arranged on the contact surface as above merely by mounting a transducer head of standard construction in a slanting attitude on a carriage which transports both the head and the pressure pad radially of the magnetic disk.

Growing community of inventors

Mitaka, Japan

Shinichi Aikawa