Optical pickup device

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

C369S112020

Reexamination Certificate

active

07738342

ABSTRACT:
An optical pickup device enables prevention of an increase of spherical aberration during tracking without needing any finite optical system. The diameters of parallel light beams (A, B, C) for the next-generation DVDs, DVDs, and CDs are limited to diameters of a, b, c (a>b>c) in accordance with the NA for each type by a light beam limiting element, the diameter of light beam B is limited to the diameter ranges of b to c and d (=0.85×c) to e (d>e>0), the diameter of the light beam C is limited to the diameter ranges of c to d and less than e. They are passed through a phase correcting element (13B) and focused on the corresponding optical recording medium signal planes by means of a common objective lens. The objective lens is so optimized that the wave front aberration to the light beam A is minimum on the signal plane of the next generation DVD. The phase correcting element (13B) has a phase correcting zones (Z1to Z4) of diffraction optical structure exhibiting a pseudo-kinoform shape of a step constitution. The spherical aberration to the light beam B is corrected in the zones (Z1, Z3). The spherical aberration to the light beam C is corrected in the zones (Z2, Z4). The light beam A is passed through all the zones of the light beam diameter a without changing the parallel light beam state by optimizing the step heights of the zones (Z1to Z4).

REFERENCES:
patent: 5930214 (1999-07-01), Kasahara et al.
patent: 6166854 (2000-12-01), Katsuma
patent: 6363037 (2002-03-01), Yamazaki
patent: 7345967 (2008-03-01), Hirai
patent: 2005/0002313 (2005-01-01), Hayashi
patent: 0 936 604 (1999-08-01), None
patent: 0 962 921 (1999-12-01), None
patent: 1 341 166 (2003-09-01), None
patent: 07-302437 (1995-11-01), None
patent: 09-145995 (1997-06-01), None
patent: 2000-056216 (2000-02-01), None
patent: 2005-011466 (2005-01-01), None
patent: 2005-085340 (2005-03-01), None
International Preliminary Examination Report (Application No. PCT/JP2006/308682) dated Nov. 1, 2007.
Supplementary European Search Report (Application No. 06732338.6) Dated Nov. 5, 2008.
Yamada, M. et al., “DVD/CD/CD-R Compatible Pick-Up With Two-Wavelength Two-Beam Laser,” IEEE Transactions on Consumer Electronics, vol. 44, No. 3, Aug. 1988, pp. 591-600.
International Search Report (Application No. PCT/JP2006/308682).

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

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

Rate now

     

Profile ID: LFUS-PAI-O-4208467

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