Objective lens, optical head apparatus, optical information...

Dynamic information storage or retrieval – Specific detail of information handling portion of system – Radiation beam modification of or by storage medium

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C369S112080

Reexamination Certificate

active

10473934

ABSTRACT:
An objective lens for converging a light beam emitted from a first light source on a recording surface (17a) of a first optical information recording medium covered with a transparent substrate (7a) and converging a light beam emitted from a second light source on a recording surface (17b) of a second optical information recording medium covered with a transparent substrate (7b) having a thickness greater than the transparent substrate (7a). On an incident plane for the light beam, there are formed a center region (A1), an intermediate region (A2) surrounding the center region (A1), and a peripheral region (A3) surrounding the intermediate region (A2). A diffraction grating (11) is provided on the lens surface of the intermediate region (A2). Between the intermediate region (A2) and the center region (A1), and also between the intermediate region (A2) and the peripheral region (A3), stepped portions (12) are provided for causing an advance or a delay of a phase of a light beam passing through the intermediate region (A2) with respect to the phases of the light beams passing through the center region (A1) and the peripheral region (A3). The stepped portions (12) are formed so that a value of a tertiary spherical aberration on the recording surface (17b) of the second optical information recording medium becomes a value that makes a jitter value of a reproduction signal from the second optical information recording medium not more than 15%.

REFERENCES:
patent: 6091691 (2000-07-01), Yoo et al.
patent: 6285646 (2001-09-01), Yoo et al.
patent: 6370103 (2002-04-01), Yamazaki et al.
patent: 6671247 (2003-12-01), Arai et al.
patent: 6687209 (2004-02-01), Ota et al.
patent: 6717906 (2004-04-01), Shimano
patent: 2002/0003767 (2002-01-01), Ota et al.
patent: 10-143905 (1998-05-01), None
patent: 11-344666 (1999-12-01), None
patent: 2000-28917 (2000-01-01), None
patent: 2000028917 (2000-01-01), None
patent: WO 0126104 (2001-04-01), None
Official translation of WO 01/26104.
English abstract and machine translation of JP 2000-028917 A.

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

Objective lens, optical head apparatus, optical information... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Objective lens, optical head apparatus, optical information..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Objective lens, optical head apparatus, optical information... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3885533

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