公开(公告)号：EP0159668A3

公开(公告)日：1987-05-13

申请号：EP85104695

申请日：1985-04-18

Applicant: HITACHI, LTD.

Inventor： Seki, Gen ,  Hayashi, Seiichi

IPC: G11B05/48 ,  G11B05/54 ,  G11B05/55 ,  G11B05/58

CPC classification number: G11B5/58 ,  G11B5/4833 ,  G11B5/54

Abstract: A magnetic head positioning apparatus includes a chassis, a driving device provided on the chassis, a guide member provided on the chassis, a carrier movably provided on the guide member, a first metallic head support mounted on the carrier and adapted to support a first magnetic head, and a second metallic head support mounted on the carrier and adapted to support a second magnetic head which is disposed to oppose the first magnetic head. A coupling member is formed on the first head support and directly connected to the driving device. By moving the coupling member by the operation of the driving device, the carrier is moved along the guide member through the first head support. Thus, it is possible for the magnetic head positioning apparatus to possess excellent resistance to environmental changes and to effect highly accurate positioning of the magnetic heads.

公开(公告)号：EP0121590A3

公开(公告)日：1985-09-18

申请号：EP83108525

申请日：1983-08-30

Applicant: VERBATIM CORPORATION

Inventor： Bond, Charles R.

IPC: G11B05/58 ,  G11B05/56 ,  G11B19/28 ,  G11B05/016 ,  G11B27/36

CPC classification number: G11B27/36 ,  G11B5/5543

Abstract: An alignment testing device comprising a magnetic media with data tracks in nonstandard locations with bidirectionally progressive degrees of misalignment for testing the alignment of the transducer head in a magnetic storage device such as a floppy disk drive. The alignment testing device allows the user to determine the boundaries of track alignments that the transducer head can read, and thereby determine any discrepency between the heads actual alignment and correct alignment.

公开(公告)号：EP0093200A3

公开(公告)日：1985-08-14

申请号：EP82111445

申请日：1982-12-10

Applicant: International Business Machines Corporation

Inventor： Klaassen, Klaas B.

IPC: G11B05/09 ,  G11B05/58 ,  G11B05/47

CPC classification number: G11B5/5965 ,  G11B5/02 ,  G11B5/03

Abstract: A method for recording high frequency signals representing data with simultaneous readout of low frequency information, such as servo information prerecorded on a magnetic disk (22), comprises the step of modulating (12) with the data (14) a carrier signal (10) having a repetition frequency displaced significantly from the baseband of the data. The nonlinearity of the recording channel shifts the modulated signal spectrum into the low frequency baseband so that the data is magnetically recorded while the low frequency prerecorded information is read out.

公开(公告)号：EP0100546A3

公开(公告)日：1985-05-15

申请号：EP83107555

申请日：1983-08-01

Applicant: HITACHI, LTD.

Inventor： Furuhata, Takashi ,  Satoh, Kenji ,  Azuma, Yoshiyuki

IPC: G11B15/18 ,  G11B15/46 ,  G11B05/58 ,  H04N05/783

CPC classification number: G11B15/4678

Abstract: A magnetic tape transport controller for a magnetic recording and reproducing apparatus in which a pilot signal for tracking control having four different frequencies is recorded on a magnetic tape (1) by a rotary magnetic head (21, 22) and the magnetic tape is transported in a playback mode at a different tape speed than that in a recording mode. The tape transport controller has means (32, 33, 34, 40) for detecting an amplitude change of a specific one of signals derived by frequency-converting a reproduced pilot signal and controlling the tape speed such that the frequency of the amplitude change is maintained at a predetermined frequency. It also has a phase control loop (36, 37, 38, 42, 43) to control the tape speed such that a phase of the specific signal coincides with a phase of a reference signal. In the playback mode in which the tape is transported at the different speed than that in the recording mode, frequencies of a local pilot signal used to frequency-convert the reproduced pilot signal are switched in the opposite order to that of the switching of the frequencies in the recording mode. A detection circuit which detects a difference between two frequencies converted signals of different frequencies and amplifies the difference inverts a polarity of an output signal for each track switching in a standard speed playback mode and does not invert the polarity in a variable speed playback mode.

公开(公告)号：EP0047666A3

公开(公告)日：1983-03-30

申请号：EP81304100

申请日：1981-09-08

Applicant: SONY CORPORATION

Inventor： Kaminaga, Kozo ,  Suzuki, Yoshinori ,  Wakisaka, Yoshiaki

IPC: H04N09/491 ,  H04N05/783 ,  G11B05/58

CPC classification number: H04N9/873

Abstract: In a video signal reproducing system which employs therein a head tracking control system in which a reproducing head is moved in the direction substantially perpendicular to its scanning direction usually along each recorded track on a tape to cause a predetermined track skip so as to scan a selected one of the recorded tracks and is provided with a detecting circuit device for detecting the phase of color signal component, for example, the R-Y component of a video signal reproduced from the recorded tracks, an additional circuit (10, 11) is provided for preventing the detection of the phase of color signal component by the detecting circuit device from being in error following a track skip where the number of tracks skipped is such that the phase sequence between successive scanned tracks is incorrect. This is achieved by controlling the detecting circuit device with information about the track skip which is obtained in the head tracking control system.

公开(公告)号：EP0030469A3

公开(公告)日：1981-12-16

申请号：EP80304413

申请日：1980-12-05

Applicant: Matsushita Electric Industrial Co., Ltd.

Inventor： Isaka, Takenobu ,  Kobayashi Masaaki

IPC: G11B05/58

CPC classification number: G11B5/588

Abstract: A video tape recorder performs tracking corrections by moving video heads using an electric-mechanical transducer vertically with respect to the scanning direction of video tracks. The video tape recorder measures cycles of synchronizing signals included in reproduced video signals, so that the electric-mechanical transducer shifts the video heads to get regular measuring, thereby allowing the video heads to accurately scan the video tracks.

公开(公告)号：EP0031500A3

公开(公告)日：1981-09-16

申请号：EP80107634

申请日：1980-12-04

Applicant: International Business Machines Corporation

Inventor： Cunningham, Earl Albert

IPC: G11B05/58

CPC classification number: G11B5/59655 ,  G11B5/5965

Abstract: A servo system is disclosed for centering a transducer over a path defined by the boundary between adjacent servo tracks on a magnetic disk in which the servo tracks are each formed by alternate long and short magnetic segments, with the short segments in one track being centred with the long segments of adjacent tracks. The servo system includes a frequency doubler circuit (18) for producing a uniform frequency square wave signal of double the fundamental frequency of the analog signal picked up by the transducer from the servo encoding, a filter (77) connected with the transducer for producing an analog double frequency signal based on the analog signal from the transducer, a synchronous detector (80) functioning as a multiplier for multiplying the double frequency square wave signal with the analog double frequency signal from the transducer, and a filter (82) for averaging the resultant pulsating position error signal to provide a steady state position error signal for any particular position of the transducer over a pair of adjacent servo tracks. The steady state position error signal is applied to a servo control and servo actuator for moving the transducer until the steady state position error signal reaches zero which corresponds with the desired centred position of the transducer over the boundary between a pair of adjacent servo tracks.

公开(公告)号：EP0257713A3

公开(公告)日：1988-05-11

申请号：EP87201577

申请日：1987-08-20

Applicant: POLAROID CORPORATION

Inventor： Ford, Vernon E. ,  Jones, Jeremy K. ,  Mader, John J. ,  Plummer, William T.

IPC: G11B05/58

CPC classification number: G11B5/59677 ,  G11B5/82

Abstract: Magnetic recording media, and magnetic recording systems using such media, are disclosed which incorporate a light-transmitting optical grating at least substantially coextensive with the magnetic recording area. A second light-transmitting optical grating is associated with the magnetic transducer or read/write head. A moire pattern is produced by light transmitted through both optical gratings, and changes in the moire pattern resulting from changes in the alignment of the optical gratings resulting from movement of the read/write head relative to the media are utilized to provide servo information to keep the magnetic transducer aligned with the magnetic track. Higher magnetic recording capacities may be obtained using such media and systems, since none of the magnetic recording area is used for servo information.

公开(公告)号：EP0180718A3

公开(公告)日：1988-05-11

申请号：EP85109033

申请日：1985-07-19

Applicant: GRUNDIG E.M.V. Elektro-Mechanische Versuchsanstalt Max Grundig holländ. Stiftung & Co. KG.

Inventor： Opelt, Christian

IPC: G11B21/10 ,  G11B05/592 ,  G11B05/588 ,  G11B05/584 ,  G11B05/58

CPC classification number: G11B5/55 ,  G11B5/58 ,  G11B5/592

公开(公告)号：EP0208605A3

公开(公告)日：1987-09-30

申请号：EP86401438

申请日：1986-06-27

Applicant: SONY CORPORATION

Inventor： Yamanouchi Hiroshi c/o Sony Corporation

IPC: G11B05/48 ,  G11B05/58 ,  G11B05/54

CPC classification number: G11B5/4833 ,  G11B5/54 ,  G11B5/58 ,  G11B21/02

Abstract: In a magnetic recording device wherein a magnetic head (15.8) is maintained in elastic contact with a recording medium, an improved magnetic head supporting device in- tegretes a hinge (31), a swingably supported arm (32) and a magrtetic head holding member (33) into a unitary flat spring member (30). Further, an elongate oil retaining bearing sleeve (41) is provided to guide the magnetic head cartridge (41) is provided to guide the magnetic head cartridge (40) in the horizontal or radial direction relative to the recording medium.