公开(公告)号：US3691317A

公开(公告)日：1972-09-12

申请号：US3691317D

申请日：1971-05-11

申请人： TED BILDPLATTEN

发明人： DICKOPP GERHARD

IPC分类号： G11B3/44 ,  G11B9/00 ,  H04R17/04

CPC分类号： G11B3/445 ,  G11B9/00

摘要： A playback head for use with a record disc containing grooves whose walls undulate to constitute a spatial representation of the time variation of a signal to be reproduced, the head carrying a stylus which engages in the groove and elastically deforms the groove walls to a substantial degree, the playback head being arranged to produce an output proportional to the reaction force exerted on the stylus by the elastically deformed groove walls, the stylus being formed to have a shallow leading edge which extends in the direction of the groove axis to contact the groove walls for a distance equal to a plurality of wavelengths of the recorded signal and a steep trailing edge which contacts the groove walls for a distance no greater than one half of a wavelength of the recorded signal, the leading and trailing edges meeting at the lowermost point of the stylus, and a lowpass filter being connected to the head output for attenuating frequencies greater than twice the lowest recorded frequency.