Diffraction grating and optical pickup device
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Sep 24, 2013
Grant Date -
Sep 6, 2007
app pub date -
Aug 17, 2006
filing date -
Mar 3, 2006
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
Disclosed are a module to detect a tracking error signal that is easy to be assembled and robust against variation in a track angle, a diffraction grating, an optical pickup, and an optical disc apparatus that enable the module to be realized, wherein a diffraction grating divided into at least three areas, first, second, and third areas, is used; the second area is an area that do not diffract light; and focusing positions of light diffracted by the first and third areas sandwiching the second area therebetween on an optical disc are arranged with a spacing of (2n−1)×t/2 in an optical disc radial direction, respectively, where n is a nonnegative integer and t is a spacing of guide grooves of the optical disc.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully