Optical disc apparatus and focusing method for the same

Details Optical disc apparatus and focusing method for the same Optical disc apparatus and focusing method for the same

2007-04-12

2010-11-30

Tran, Thang V (Department: 2627)

Dynamic information storage or retrieval

With servo positioning of transducer assembly over track...

Optical servo system

C369S044290, C369S044340

Reexamination Certificate

active

07843775

ABSTRACT:
An optical disc apparatus and a focusing method for the same prevent a focusing start error of an optical pickup when using a ring-shaped lens to handle multiple wavelengths, and allow the optical pickup to start focusing at the correct starting time. To write and/or read data to and/or from an optical disc, an optical pickup in the optical disc apparatus emits a laser beam to the disc through an objective lens, and reads a reflected beam to output a read signal. The optical pickup outputs a signal based on the read reflected beam. An actuator controls the position of the objective lens so that the laser beam is focused on a surface of the disc. A focusing controller performs focusing operations on the actuator using a focus error signal generated from the signal outputted from the optical pickup. A focusing start time detector processes the read signal used to generate the focus error signal and detects when to start the focusing control of the focusing controller.

REFERENCES:
patent: 4542491 (1985-09-01), Takasago et al.
patent: 5060215 (1991-10-01), Kawamura et al.
patent: 5086420 (1992-02-01), Doi
patent: 5363357 (1994-11-01), Niwayama
patent: 5675569 (1997-10-01), Yamaguchi et al.
patent: 5757745 (1998-05-01), Takeya
patent: 5903530 (1999-05-01), Tateishi et al.
patent: 6240054 (2001-05-01), Takeya et al.
patent: 6487153 (2002-11-01), Kamiyama et al.
patent: 6628580 (2003-09-01), Kishimoto et al.
patent: 2003-051127 (2003-02-01), None

Affiliated with

Also associated with

Rating

Optical disc apparatus and focusing method for the same 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 disc apparatus and focusing method for the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical disc apparatus and focusing method for the same will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4248280