Teac Corporation

Tsutomu Morita

Hiroshi Tsuyuguchi

Makoto Shoji

Shozo Toma

Kazuhiro Hiraki

Kenji Shimozawa

Yasushi Noda

Yoshiaki Sakai

Hiroyuki Onda

Masasi Tanaka

Katsumi Aoyama

Makoto Shouji

Makoto Syoji

An optical disk apparatus includes a disk servo unit which generates a servo signal based on a data signal read from an optical disk. The servo signal is supplied to a disk motor to control a rotation of the motor so that a linear velocity of the disk is kept constant when data is read from or written onto the disk. The disk servo unit is connected to the motor when the data is read from or written onto the disk, so that the servo signal is supplied to the motor, and the disk servo unit is disconnected from the motor when a pickup jumps from a present track of the disk to a destination track thereof so that the supply of the servo signal to the motor is inhibited. A velocity change signal which enables the motor to increase or decrease a rotating speed of the motor is generated depending on which one of two directions of the track jump is specified by a direction signal. A time signal which defines an estimated time of the track jump required to change an angular velocity at the present track to an angular velocity at the destination track is generated. The optical disk apparatus supplies the velocity change signal to the motor during the estimated time.

Constant linear velocity optical disk apparatus having improved

An optical recording/reproducing apparatus records an information signal on a rotary optical disk by irradiating an optical beam having an optical power such that an energy sufficient to cause recording of the information signal is incident to a unit area of the optical disk in a unit time while revolting to optical disk at a first predetermined speed, and plays back the information signal from the optical disk by irradiating the optical beam while revolving the optical disk with a second predetermined speed such that the energy incident to a unit area of the optical beam in a unit time at the time of playback does not cause recording on the optical disk.

Optical recording/reproducing apparatus

A tracking servo apparatus for performing a control so that a light beam is irradiated onto a predetermined track of an information recording surface of a disc shaped recording medium comprising an optical system for focusing the light beam on the information recording surface of the disc shaped recording medium, a holder for holding the optical system, tracking error detection circuit for detecting a tracking error of the light beam irradiated on the information recording surface with respect to the predetermined track by receiving a reflected light of the irradiated light beam that has been reflected from the information recording surface, and outputs an error signal in accordance with the tracking error, and a piezoelectric device which is connected to the holding means, and is deformed when supplied with an amplified voltage of the error signal so as to deflect the holder and thus moves the optical system so that the light beam is irradiated on to the predetermined track of the information recording surface.

Optical tracking servo apparatus

An optical recording/reproducing module comprises a housing defined with a depression, a focusing actuator provided on one side of the housing for carrying an objective lens such that the lens is movable in a direction perpendicular to the aforementioned one side, an optical system accommodated in the depression, the optical system includes an optical source for producing a first optical beam to be directed to the objective lens, an optical detector for detecting a second optical beam received by the objective lens and incident to the optical detector, the optical detector further produces an electrical output signal responsive to the second optical beam, and an array of optical elements for guiding the first optical beam produced by the optical source to the objective lens and for guiding the second optical beam received by the objective lens to the optical detector, a cover lid adapted to be mounted on the one side of the housing, the cover lid has a shape adapted to close the depression, and an electrical system provided on the cover lid for driving the optical source and for amplifying the electrical output signal from said optical detector.

Optical recording/reproducing module having reduced size

An optical head apparatus applicable to an optical disc apparatus comprises, a case body having an open surface and a window through which an opto-electronic component can be positioned and housing optical components inside it, a lid being attachable and detachable with respect to the open surface of the case body, and a flexible printed circuit board having a base portion which is adhered to the lid and on which electronic components are mounted and a protruding portion protruding from the base portion and having an opto-electronic component fixed to the distal end portion of it, the opto-electronic component being electrically connected with an electronic circuit which is formed by the electronic components, the distal end portion of the protruding portion of the flexible printed circuit board being fixed to the case body so that the opto-electronic component is position to the window.

Optical head apparatus applicable to optical disc apparatus

An optical recording and reproducing apparatus includes a controlling circuit for controlling a light intensity of a laser beam emitted by a laser diode. The controlling circuit sets the light intensity in a verifying mode at a level lower than those in data read and write modes. The verifying mode is a mode for verifying whether or not the recording or reproducing apparatus can operate correctly. The apparatus also comprises a verifying circuit for comparing the reproduced information signal obtained in the verifying mode with a reference information signal which corresponds to the information signal written into the optical disc.

Optical recording and reproducing apparatus for verifying correct

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 floppy disk drive which, together with one or more like devices, is daisy chained to host equipment comprising a central processor unit and an associated controller. Each disk drive comprises a disk motor for rotating 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. The host equipment produces, among other control signals, a MOTOR ON signal for the on/off control of the disk motor via the disk motor drive circuit. In order to avoid waste of electric power, not only the disk motor drive circuit but also at least one, preferably both, of the head motor drive circuit and the read/write circuit is connected to a common power line via a power control switch which is closed only when the MOTOR ON signal is in a prescribed state to cause rotation of the disk motor.

Power saving circuit arrangement for an apparatus for data transfer with

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 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.

Growing community of inventors

Musashino, Japan

Tsutomu Morita