Focus error detector

Details Focus error detector Focus error detector

1994-12-28

1996-07-16

Epps, Georgia Y.

Dynamic information storage or retrieval

Specific detail of information handling portion of system

Radiation beam modification of or by storage medium

369 4423, 369 54, 369 58, 369110, 369112, 369120, G11B 700

Patent

active

055373844

ABSTRACT:
A focus error detector for detecting a focus error of an objective lens with respect to an optical disk. The focus error detector includes a beam splitter for splitting light reflected from the optical disk. Two critical angle prisms having critical angle reflecting surfaces are included for respectively reflecting the light rays from the beam splitter at the respective critical angles onto two bisectional photo-detectors. The bisectional photo-detector generates detecting signals responsive to the amount of light received. The detecting signals are differentiated and added in a direction offsetting a shift or tilt of the reflected light. Accordingly, only the focus error signal is detected, irrespective of the tilt and shift of the optical axis of the reflected light. Thus, malfunction of an optical pickup is prevented, thereby providing for the uncorrupted recording and reproduction of data.

REFERENCES:
patent: 5189655 (1993-02-01), Ogata et al.
patent: 5383173 (1995-01-01), Kim et al.
patent: 5400314 (1995-03-01), Lee
patent: 5406532 (1995-04-01), Nishikawa
patent: 5488599 (1996-01-01), Akiyama et al.

Affiliated with

Also associated with

Rating

Focus error detector does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Focus error detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Focus error detector will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1790101