Apparatus for recording and reading an optical disk, having redu

Details Apparatus for recording and reading an optical disk, having redu Apparatus for recording and reading an optical disk, having redu

1987-12-03

1989-08-08

Richardson, Robert L.

Dynamic information storage or retrieval

Control of storage or retrieval operation by a control...

Mechanism control by the control signal

369 44, G11B 700

Patent

active

048559830

ABSTRACT:
A push-pull type tracking error signal produced by reflected light from pits on an ID area of an optical disk is averaged and sampled during a period while a light spot is scanned over the ID areas. An averaged value of a signal representative of the reflected light is stored for each sector of the disk, this value being a first sampled tracking error signal. The tracking error signal is also sampled while the light spot is scanned over a vacant zone having no pits in a data area, storing a second sampled tracking error signal. This vacant zone to be sampled is located either before or after a sequence of data bits in each sector. The first sampled tracking error signal is smaller than the second sampled tracking error signal because of the AC component produced by the pits. Thus, when an offset of the tracking exists, though the tracking error signal is kept almost zero by the servo control, the first sampled tracking error signal is not zero. Therefore, differences between the two tracking error signals indicates the amount of the offset. This offset signal may be visually monitored for adjusting the offset of the apparatus, or may be fed back for the tracking servo. The invention can be applied to a disk format having no mirror mark. The circuit of the invention is simple and inexpensive, because no high frequency need be output.

REFERENCES:
patent: 4663751 (1987-05-01), Kaku et al.
patent: 4730294 (1988-03-01), Funada
patent: 4748609 (1988-05-01), Yonczawa et al.

Affiliated with

Also associated with

Rating

Apparatus for recording and reading an optical disk, having redu does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus for recording and reading an optical disk, having redu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for recording and reading an optical disk, having redu will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-911359