Teac Corporation

Shozo Toma

Hiroshi Tsuyuguchi

Tsutomu Morita

Makoto Shoji

Kazuhiro Hiraki

Yoshiaki Sakai

A data transfer apparatus for use with a replaceable disklike record medium such as a flexible magnetic disk having data storage tracks thereon, comprising a disk drive motor for imparting rotation to the record medium, and a head transport motor for transporting a transducer head or heads radially of the record medium so as to enable the transducer head or heads to access the individual data storage tracks on the record medium for data transfer therewith. Also included is a control and drive circuit for controllably energizing the head transport motor. When the record medium is not loaded in the apparatus, the control and drive circuit holds the supply voltage of the head transport motor zero, or lwoer than its normal operating voltage for head transportation, for saving power. Then, as the record medium is loaded into the apparatus, the control and drive circuit applies the normal operating voltage to the head transport motor preparatory to the commencement of data transfer, thereby automatically recorrecting the head position on the record medium.

Circuit arrangement and method for saving power in magnetic disk

A data transfer apparatus for use with a replaceable disklike record medium such as a flexible magnetic disk having data storage tracks thereon, comprising a disk drive motor for imparting rotation to the record medium, and a head transport motor for transporting a transducer head or heads radially of the record medium so as to enable the transducer head or heads to access the individual data storage tracks on the record medium for data transfer therewith. Also included is a control and drive circuit for controllably energizing the head transport motor. When the disk drive motor is out of rotation, the control and drive circuit holds the supply voltage of the head transport motor zero, or lower than its normal operating voltage for head transportation, for saving power. Then, as the disk drive motor is set into rotation, the control and drive circuit applies the normal operating voltage to the head transport motor preparatory to the commencement of data transfer, thereby automatically recorrecting the head position on the record medium.

Data transfer apparatus with a disklike record medium and a method of

A flexible magnetic disk drive is disclosed which has a disk drive motor for imparting rotation to the magnetic disk under the control of a 'motor on' signal, and a stepping motor capable of stepwise rotation in response to stepping pulses for transporting a transducer head or heads radially of the magnetic disk for track to track accessing. Connected to the transducer heads for processing data transferred between them and the magnetic disk, a read/write circuit is connected to a supply terminal via a switching transistor. This switching transistor has connected to its base a switch control circuit for holding the switching transistor nonconductive when the disk drive motor is out of rotation and when the stepping motor is in rotation, and for holding the transistor conductive at least during the progress of data transfer between the transducer heads and the magnetic disk. Preferably, the switch control circuit is further adapted to hold the power control switch open from the moment the disk drive motor is set into rotation to the moment the speed of rotation of the disk drive motor builds up to a prescribed percentage of a normal speed at which data transfer is effected between the transducer heads and the record medium.

Power-saving data transfer apparatus with a flexible magnetic disk or

An apparatus for data transfer with a magnetic disk having a metal made hub attached centrally thereto, with the hub having a first opening defined centrally therein and a second opening defined eccentrically therein. The apparatus includes a turntable mounted on a drive spindle which is engageable in the first opening in the hub of the magnetic disk loaded on the turntable. A retractable drive pin is mounted eccentrically on the turntable so as to be sprung into engagement in the second opening in the disk hub upon register therewith. In order to assure engagement of the drive pin in the second opening in the disk hub immediately upon loading of the magnetic disk on the turntable, a disk drive motor for driving the turntable via the drive spindle is connected to a supply terminal via a power control switch. When the magnetic disk is loaded on the turntable while power is being supplied from the supply terminal, a switch control circuit closes the power control switch, for causing the rotation of the turntable relative to the magnetic disk, for a preassigned length of time sufficient for the drive pin to become engaged in the second opening in the disk hub. The magnetic disk can therefore be set into rotation for immediate commencement of data transfer upon delivery of a 'motor on' signal from host equipment to the power control switch.

Data transfer apparatus with a disklike record medium

A data transfer apparatus is disclosed as typified by a floppy disk drive which, together with one or more like devices, is daisy chained to a central processor unit via a controller. Each disk drive comprises a disk motor for driving a record disk under the control of a disk motor drive circuit, a head motor for incrementally moving a transducer head radially of the record disk under the control of a head motor drive circuit, and a read/write circuit for processing data read from, or to be written on, the record disk via the transducer head. Also included in each disk drive is a sensor control circuit associated with an optical sensor assembly for producing a DISK PRESENCE signal representative of the presence or absence of the record disk in the disk drive. In order to avoid waste of power, at least one, preferably all, of the disk motor drive circuit, head motor drive circuit, and read/write circuit is connected to an external power line via a power control switch which is closed in response to the DISK PRESENCE signal only when the record disk is loaded in the disk drive. Additional embodiments are disclosed wherein the power control switch responds not only to the DISK PRESENCE signal but also to a standard MOTOR ON signal or DRIVE SELECT signals, or to both, which are supplied from the host equipment.

Data transfer apparatus for use with a flexible magnetic disk or the like

A magnetic disk drive is disclosed which has a write circuit for alternately exciting the a pair of coils of a read/write head in response to a two level write data signal when a write gate signal is in a prescribed state, thereby causing the coils to create magnetic fluxes in the opposite directions in the core. The write circuit excites a different one of the coils of the read/write head each time the write data signal changes in level from a predetermined one to the other. A final excitation circuit is provided for delaying, for example, the write gate signal for a preassigned length of time in order to cause the write circuit to excite a preselected one of the coils of the read/write head in a prescribed direction upon completion of the writing of the write data signal. Consequently, the residual magnetism of the read/write head is of one and the same orientation upon completion of writing, making possible the accurate detection of the peaks of the reproduced waveform at the time of subsequent reading.

Magnetic data transfer apparatus having a combined read/write head

A data transfer apparatus is disclosed as exemplified by a floppy disk drive which has photoelectric sensors such as a TRACK ZERO sensor for sensing whether a transducer head or heads are in the 'track zero' position on the floppy disk, and a FILE PROTECT sensor for sensing whether the disk is protected against erasure of any prerecorded data. In order to avoid waste of power, at least the TRACK ZERO sensor, preferably the FILE PROTECT sensor as well, has its light source such as an LED connected to a power supply via a power saving switch herein shown as a switching transistor. Connected to the base of the power saving transistor is a switch control circuit which causes conduction through the transistor, and hence the energization of the sensor light source, only when the operation of the sensor is required, as for a preassigned length of time immediately after the apparatus is electrically turned on.

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Kokubunji, Japan

Shozo Toma