Device for scanning an optically readable record carrier

Details Device for scanning an optically readable record carrier Device for scanning an optically readable record carrier

1996-12-13

1998-12-22

Edun, Muhammad N.

Dynamic information storage or retrieval

With servo positioning of transducer assembly over track...

Optical servo system

369 4412, 369 4441, 369112, G11B 709

Patent

active

058525920

ABSTRACT:
A device for optically scanning an information layer by means of a focused radiation beam. Radiation reflected from the information layer is made astigmatic by an oblique plane parallel plate and subsequently detected by a detection system. An electronic circuit derives two focus error signals, each representing the distance between the focal point of the radiation beam and the information plane. The first focus error signal is formed from the high-frequency components in the electrical detector signals, and the second focus error signal is formed from the low-frequency components in the same detector signals. A second electronic circuit combines the two focus error signals into a combined focus error signal to control a focus servo loop. The circuit changes the control gradually from one focus error signal to the other.

REFERENCES:
patent: 5436876 (1995-07-01), Yokoyama et al.
patent: 5602383 (1997-02-01), Takekoshi et al.
patent: 5610883 (1997-03-01), Yanagawa
patent: 5633846 (1997-05-01), Okuyama et al.

Affiliated with

Also associated with

Rating

Device for scanning an optically readable record carrier does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Device for scanning an optically readable record carrier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for scanning an optically readable record carrier will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2053134