Optical head

Details Optical head Optical head

1997-07-10

2001-05-22

Young, W. R. (Department: 2753)

Dynamic information storage or retrieval

With servo positioning of transducer assembly over track...

Optical servo system

C369S094000, C369S275300, C369S286000

Reissue Patent

active

RE037185

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates generally to an optical head of an optical disc recording-reproducing apparatus for recording and reproducing information to an optical disc, and more particularly to a convertible optical head which is applicable to both the standard optical disc and a nonstandard optical disc.
DESCRIPTION OF THE RELATED ART
A rewritable optical disc such as a magneto-optical disc is standardized by the “Draft Proposal DP10090 of ISO Standard”. According to the standard of the Draft Proposal, the rewritable optical disc is 86 mm in diameter and has a recording area on one surface of a transparent polycarbonate substrate of 1.2 mm thick. Moreover, a protection layer of 0.2 mm thick at the most is placed on the recording area, and thus entire thickness is 1.4 mm at the most. In a magneto-optical disc according to the standard, a magnetic device is arranged to generate a magnetic field in immediate proximity to the recording area. A recording capacity of the above-mentioned standard optical disc is 128 MB, for example. The rewritable optical disc in the prior art mentioned above has the recording area on only one side of the optical disc, and hence significant increase of the recording capacity has been impossible. In order to significantly increase the recording capacity, an optical disc having the recording area on both sides of a substrate is devised, and hence a convertible optical head must be developed to be applicable to both the standard optical disc and the optical disc having the recording area on both the sides of the substrate.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide an optical head of an optical disc recording-reproducing apparatus which can use an optical disc having a recording area on one side of a substrate in accordance with the draft proposal DP10090 of ISO standard or an optical disc having recording areas on both sides of a substrate in order to increase recording capacity.
The optical head in accordance with the present invention comprises:
laser light emitting means for emitting laser light,
collimating means for collimating the laser light emitted by the laser light emitting means,
focusing means for focusing the laser light collimated by the collimating means on a recording area of an optical disc,
a beam splitter for separating laser light reflected from the recording area of the optical disc,
laser light sensing means for detecting laser light separated by the beam splitter,
at least one optical plate for correcting aberration of the focusing means, and
actuator means for positioning the optical plate between the optical disc and the focusing means or for removing the optical plate therefrom.
While the novel features of the invention are set forth particularly in the appended claims, the invention, both as to organization and content, will be better understood and appreciated, along with other objects and features there, from the following detailed description taken in conjunction with the drawings.


REFERENCES:
patent: 4230939 (1980-10-01), de Bont et al.
patent: 4353767 (1982-10-01), Wilkinson
patent: 4432002 (1984-02-01), Ando
patent: 4450452 (1984-05-01), Ando et al.
patent: 4561086 (1985-12-01), Geyer
patent: 4712207 (1987-12-01), Reno
patent: 4800112 (1989-01-01), Kano et al.
patent: 4837758 (1989-06-01), Motoyama et al.
patent: 4892606 (1990-01-01), Miyazaki et al.
patent: 4959824 (1990-09-01), Ueda et al.
patent: 4977019 (1990-12-01), Schaefer
patent: 5533001 (1996-07-01), Watanabe et al.
patent: 3203599 (1982-08-01), None
patent: 0128960 (1984-12-01), None
patent: 0144436 (1985-06-01), None
patent: 245953 (1987-11-01), None
patent: 0268352 (1988-05-01), None
patent: 0288570 (1988-11-01), None
patent: 339368 (1989-11-01), None
patent: 0439100 (1991-07-01), None
patent: 0473785 (1992-03-01), None
patent: 56-148749 (1981-11-01), None
patent: 57-172544 (1982-10-01), None
patent: 59-15913 (1984-01-01), None
patent: 60-243834 (1985-12-01), None
patent: 62-66433 (1987-03-01), None
patent: 62-167636 (1987-07-01), None
patent: 62-264456 (1987-11-01), None
patent: 63-96745 (1988-04-01), None
patent: 63-268145 (1988-11-01), None
patent: 1-224941 (1989-09-01), None
patent: 1-251376 (1989-10-01), None
patent: 1-267856 (1989-10-01), None
patent: 2-05245 (1990-01-01), None
patent: 88/06337 (1988-08-01), None
“Optical Disc Technology,”pp. 60-65, Feb. 10, 1989.

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