Optical pickup

Details Optical pickup Optical pickup

2011-04-26

2011-04-26

Hindi, Nabil Z (Department: 2627)

Dynamic information storage or retrieval

Specific detail of information handling portion of system

Radiation beam modification of or by storage medium

C369S112030

Reexamination Certificate

active

07933188

ABSTRACT:
To reduce a bad influence on a tracking control signal and a data signal by reflected light from an adjacent layer on a multi-layer disc as stray light, the following device is made in the invention. Reflected light from the multi-layer optical disc including stray light from another layer is once converged by a reflected light condenser lens and is reflected on a reflector. A grating which prevents zero-order light from being generated by setting groove depth to λ/4 and which is set to pitch to prevent positive and negative first- or higher-order diffracted lights from returning to the reflected light condenser lens is arranged between the lens and the reflector including an optical axis with the grating apart from the reflector. Hereby, as reflected light from another layer is cut off though reflected light from a corresponding layer is transmitted to a detector, a detected control signal and a detected data signal are not influenced by reflected light from another layer.

REFERENCES:
patent: 6956807 (2005-10-01), De Vries et al.
patent: 2009/0168628 (2009-07-01), Nishimoto et al.
patent: 2002-367211 (2002-12-01), None
patent: 2005-302084 (2005-10-01), None
patent: 2007-233283 (2007-09-01), None
H. Richter, et al., “System Aspects of Dual-Layer Phase-Change Recording with high Numerical Aperture Optics and Blue Laser”, Jpn. J. Appl. Phys. vol. 42 (Feb. 2003) pp. 956 to 960.

Affiliated with

Also associated with

Rating

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2702777