公开(公告)号：US3599989A

公开(公告)日：1971-08-17

申请号：US3599989D

申请日：1969-11-17

Applicant: IBM

Inventor： KRUSPE HENRY R ,  PERKINS NORWOOD KENNETH

IPC: G11B21/02 ,  G11B19/20 ,  G11B19/24 ,  G11B19/28 ,  G11B21/04 ,  G11B21/10 ,  G11B25/04

CPC classification number: G11B19/20 ,  G11B19/24 ,  G11B21/106 ,  G11B25/043

Abstract: The invention concerns dictation apparatus making use of disctype record media for the recording and reproducing of audio signals and particularly concerns mechanisms for effecting a desired standard amount of review of previously dictated material irrespective of the relative location of a sound transducer with respect to the disc. Customarily, in a disc-type apparatus, means are provided for relatively moving a transducer with respect to the disc media to trace a spiral sound track from the outer portion of the disc toward the inner portion. This may result in a variance in the amount of material that is reviewed during each operation of an associated review or backspace mechanism, and the present invention concerns itself with establishing a standardized increment of review in such apparatus.

公开(公告)号：US3559999A

公开(公告)日：1971-02-02

申请号：US3559999D

申请日：1968-12-13

Applicant: IBM

Inventor： PERKINS NORWOOD KENNETH

IPC: G11B5/54 ,  G11B15/18 ,  G11B5/52 ,  G11B21/04

CPC classification number: G11B15/1808 ,  G11B5/54

Abstract: A magnetic head, which has an erase gap and a record-playback gap, is movable in opposite directions across a recording medium and always has its erase gap positioned in advance of the recordplayback gap irrespective of the direction of movement of the head.