Error signal detecting apparatus of optical pickup adopting holo

Dynamic information storage or retrieval – With servo positioning of transducer assembly over track... – Optical servo system

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

369 4437, 369103, G11B 700

Patent

active

061670049

ABSTRACT:
An error signal detecting apparatus for an optical pickup employing a hologram grating, including a sensing lens for focusing light reflected from a recording medium, a hologram grating having first through fourth pattern regions arranged clockwise in a 2.times.2 matrix arrangement, for diffracting light incident from the sensing lens in different directions, wherein the first through fourth pattern regions a, b, c and d are formed such that a first focus of the +1st-order diffracted beams diffracted by the first and third pattern regions is relatively farther from the sensing lens than a second focus of the +1st-order diffracted beams diffracted by the second and fourth pattern regions, a photodetector disposed between the first and second focuses and having first through fourth light receiving units, for receiving the beams diffracted by the first through fourth pattern regions and independently photoelectrically converting the same, and a signal operation unit for detecting a focus error signal and/or a track error signal from detection signals of the light receiving parts. The error signal detecting apparatus can suppress generation of an offset of a focus error signal due to a change in the wavelength of a light source and an offsets of the focus error signal and track offset signal due to deviations of the photodetector.

REFERENCES:
patent: 5717675 (1998-02-01), Yamamoto
patent: 5737296 (1998-04-01), Komma et al.
patent: 5748599 (1998-05-01), Yamamoto et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Error signal detecting apparatus of optical pickup adopting holo does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Error signal detecting apparatus of optical pickup adopting holo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Error signal detecting apparatus of optical pickup adopting holo will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1002682

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.