Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
1999-02-17
2001-03-13
Huber, Paul W. (Department: 2651)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S053220, C369S053370, C369S112240, C369S112230
Reexamination Certificate
active
06201777
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for discriminating a plurality of types of optical disks having different substrate thicknesses from each other and reproducing information therefrom, and more particularly, it relates to an apparatus for identifying each optical disk by a reproducing signal for the optical disk.
2. Description of the Background Art
There is provided an optical disk, such as a CD-ROM, having a thickness of about 1.2 mm for reading information with a semiconductor laser. In this type of optical disk, focus servo control and tracking servo control are performed on a pickup objective lens thereby irradiating a pit train of a signal recording surface with a laser beam and reproducing signals. In recent years, high densification progresses for recording dynamic images for a long time.
For example, an SD standard for recording information of about 5 Gbytes on a single side of an optical disk having the same diameter of 12 cm as a CD-ROM has been proposed. A single SD which is prepared by bonding two SDs each having a thickness of about 0.6 mm to each other can record information of about 10 Gbytes.
Japanese Patent Laying-Open No. 5-303766 (1993) proposes an apparatus for enabling reproduction of information from a high density optical disk provided with a thin substrate having a thickness of 0.6 mm and from a standard density optical disk provided with a substrate having a standard thickness of 1.2 mm with a single optical pickup.
This apparatus employs an objective lens having a numerical aperture of 0.6, which is designed to reproduce information from a high-density disk with a shorter-wavelength laser beam. An aperture for shielding an aberration corrector from an outer peripheral side of the laser beam thereby reducing the effective numerical aperture in case of reproducing information from an optical disk having a standard thickness and a standard density is inserted in a light source side of the objective lens.
In order to reproduce information from an SD as well as from a CD with a single pickup, it is important to identify the type of each optical disk which is set on a reproducing apparatus. Japanese Patent Laying-Open No. 6-259804 (1994) discloses a method related to this type of technique. This method is adapted to irradiate optical disks with light through an optical pickup, for discriminating the optical disks from each other by detecting differences between positions of reflected light from the optical disks.
In the technique disclosed in Japanese Patent Laying-Open No. 6-259804, each optical disk is irradiated with a beam emitted from a semiconductor laser unit which is stored in the optical pickup through an objective lens so that the optical disk is identified by the detected position of the reflected light. Thus, the operation for identifying each optical disk is required before starting an operation of reproducing information from the optical disk. Thus, the optical disk cannot be quickly identified. Further, a deflected optical disk cannot be correctly identified due to an influence of the deflection, since the position of the reflected light is detected.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an apparatus for discriminating optical disks from each other and reproducing information therefrom, which can quickly and correctly identify each optical disk for thereafter reproducing information from the same.
Another object of the present invention is to provide an apparatus for discriminating optical disks from each other and reproducing information therefrom, which can identify each optical disk for thereafter reproducing information from the same in a simple structure.
Still another object of the present invention is to provide a method of quickly and correctly identifying each optical disk.
A further object of the present invention is to provide a method of quickly and correctly identifying each optical disk through the characteristics of a reproducing signal for the optical disk.
The aforementioned objects can be attained by an apparatus for discriminating optical disks from each other including the following elements:
The inventive apparatus for discriminating optical recording media from each other and reproducing information therefrom includes an optical pickup for picking up control signals necessary for reproduction from optical recording media having different thicknesses, a discriminator for discriminating the types of the optical recording media on the basis of the picked-up control signals, and a reproducer for reproducing information from the optical recording media with the pickup.
The optical pickup picks up the control signals necessary for reproduction from the optical recording media having different thicknesses for discriminating the optical recording media on the basis of the signals and reproducing information therefrom, whereby an apparatus for discriminating optical recording media from each other and reproducing information therefrom which can quickly and correctly discriminate various types of optical disks from each other and thereafter reproduce information therefrom can be provided.
Preferably, the optical pickup includes a first optical pickup including an objective lens having a first numerical aperture and a second optical pickup including an objective lens having a second numerical aperture which is different from the first numerical aperture.
In another aspect of the present invention, a method of discriminating the types of a plurality of optical recording media and reproducing information therefrom includes the steps of preparing a pickup which can pick up control signals necessary for reproduction from the optical recording media having different thicknesses, discriminating the types of the optical recording media on the basis of the picked-up signals, and reproducing information from the optical recording media with the pickup on the basis of the results of the discrimination.
The control signals necessary for reproduction are picked up from the optical recording media having different thicknesses and the types of the optical recording media are discriminated on the basis of the picked-up control signals so that information is reproduced from the optical recording media on the basis of the results of the discrimination, whereby a method which can quickly and correctly discriminate optical recording media having different thicknesses from each other and reproduce information therefrom can be provided.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
REFERENCES:
patent: 5003521 (1991-03-01), Yoshida et al.
patent: 5235581 (1993-08-01), Miyagawa et al.
patent: 5396698 (1995-03-01), Orthmann et al.
patent: 5408243 (1995-04-01), D'Hont
patent: 5729510 (1998-03-01), Kasahara et al.
patent: 0 302 355 (1989-02-01), None
patent: 4094502 (1992-03-01), None
patent: 5-303766 (1993-11-01), None
patent: 6-259804 (1994-09-01), None
Copy of European Patent Office Communication for European Patent Office Application No. 96113479.8 dated Jan. 6, 1997, including European Search Report.
Copy of European Patent Office Notification of European Publication and Information on Application for European Patent Office Application No. 96113479..8 dated Jan. 31, 1997.
Copy of European Patent Office Communication for European Patent Office Application No. 96113479.8 dated Jul. 3, 1997.
Antennenbuch, Franchkh-Kosmos Verlags-GmbH & Co., Stuttgart 1991, p. 389.
Harada Toshio
Ichiura Shuichi
Kajiyama Seiji
Kanou Yasuyuki
Shimizu Masami
Armstrong, Westerman Hattori, McLeland & Naughton
Huber Paul W.
Sanyo Electric Co,. Ltd.
LandOfFree
Apparatus for discriminating optical recording media of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for discriminating optical recording media of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for discriminating optical recording media of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2464698