Focus error detecting device

Details Focus error detecting device Focus error detecting device

1993-08-19

1995-09-26

Young, W. R.

Dynamic information storage or retrieval

With servo positioning of transducer assembly over track...

Optical servo system

369 4442, 369112, 369120, G11B 709

Patent

active

054539625

ABSTRACT:
A focus error detecting device includes a reflected beam splitter and at least two two-division photodetectors. The reflected beam splitter includes a diffraction grating part and a non-diffraction grating part separated by a line dividing a reflected beam. The dividing line projects to a line orthogonal to a guide groove on the information recording medium. The diffraction grating part produces a first split beam, and non-diffraction grating part produces a second split beam. Each two-division photodetector receives one of the first and second split beams incident and their light receiving sections, and produces a signal for effecting focus control.

REFERENCES:
patent: Re33548 (1991-03-01), Kime
patent: 4079248 (1978-03-01), Lehureau et al.
patent: 5161139 (1992-11-01), Inoue et al.
patent: 5173890 (1992-12-01), Miyake et al.
patent: 5270996 (1993-12-01), Ono
Bouwhuis, "Principles of Optical Disk System", Adam Hilger (1985), pp. 77-79.
Irie, "Focus Sensing Characteristics of the Pupil Obscuration Method for Continuously Grooved Disks", Proc. Int. Symp. on Optical Memory, 1987, Japanese Journal of Applied Physics, vol. 26 (1987), Supplement 26-4, pp. 183-186.

Affiliated with

Also associated with

Rating

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1556195