公开(公告)号：DE3669088D1

公开(公告)日：1990-03-29

申请号：DE3669088

申请日：1986-11-04

Applicant: IBM

Inventor： DOST MARTIN HANS-ULRICH ,  HOPNER EMIL ,  MELAS CONSTANTIN MICHAEL ,  PROVAZEK LIONEL DANIEL

IPC: G11B5/035 ,  G11B5/09 ,  G11B20/10 ,  G11B20/22 ,  H04B3/04 ,  H04L25/03

Abstract: A pulse signal conditioner filters and equalizes signal pulses representing digital data whether or not obtained from a magnetic recording device. Modified low pass filters filter (23, 25) the pulse signals and also derive and feed forward the second time derivative of the filtered pulse signals. The filtered pulse and the second time (234, 254) derivative thereof are combined to (230, 250) slim the pulse. Further slimming is provided by delay line equalizers (27, 29) having three paths. A first path (271) for attenuating the pulse signals, a second path (272) for delaying the pulse signals for a first delay, and a third path (273-274) for delaying the pulse signals for a second delay and attenuation. Pulse signals from the three paths are combined (270) to further slim the pulse.

公开(公告)号：DE3374729D1

公开(公告)日：1988-01-07

申请号：DE3374729

申请日：1983-09-20

Applicant: IBM

Inventor： DOST MARTIN HANS-ULRICH ,  LIU CHUNG CHUAN ,  MUELLER FRANCIS EDWARD

IPC: G05D3/12 ,  G11B5/596 ,  G11B21/10 ,  G11B5/58

Abstract: A track-seeking and track-following servo encodement and detection system employs a servo pattern using a reference signal and control signals, the control signals having an orthogonal phase relationship to each other by cyclically revolving in phase by 90 DEG , 180 DEG , 270 DEG , and repeating this pattern every four tracks.