Optical disc and optical disc device

• US 7,907,493 B2
• Filed: 10/30/2007
• Issued: 03/15/2011
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Ogawa, Masaharu, Takeshita, Nobuo, Nakahara, Hironori
• Primary Examiner(s): Feild; Joseph H
• Assistant Examiner(s): Heyi; Henok G
• Application Number:
  US11/978,641
• Publication Number:
  US 20080068969A1
• Time in Patent Office: 1,232 Days
• Field of Search: None
• US Class Current: 369/100
• CPC Class Codes: G11B 19/122 involving the detection of an identification or authentication mark record carriers indicating unauthorised or prior use G11B23/28
• CPC Class Codes: G11B 20/1217 on discs
• CPC Class Codes: G11B 2007/0006 adapted for scanning different types of carrier, e.g. CD & DVD
• CPC Class Codes: G11B 2007/0013 for carriers having multiple discrete layers
• CPC Class Codes: G11B 2220/235 Multilayer discs, i.e. multiple recording layers accessed from the same side
• CPC Class Codes: G11B 27/105 of operating discs
• CPC Class Codes: G11B 27/329 on a disc [VTOC]
• CPC Class Codes: G11B 7/00736 Auxiliary data, e.g. lead-in, lead-out, Power Calibration Area [PCA], Burst Cutting Area [BCA], control information sector headers or adresses in prepits G11B7/00745; address data in track wobble G11B7/24082
• CPC Class Codes: G11B 7/0079 Zoned data area, e.g. having different data structures or formats for the user data within data layer, Zone Constant Linear Velocity [ZCLV], Zone Constant Angular Velocity [ZCAV], carriers with RAM and ROM areas
• CPC Class Codes: G11B 7/0945 Methods for initialising servos, start-up sequences
• CPC Class Codes: G11B 7/1275 Two or more lasers having different wavelengths
• CPC Class Codes: G11B 7/24038 Multiple laminated recording layers

Abstract

In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.

Claims

1. An optical data storage system comprising:

a laser light source for producing a laser beam;

a medium receptor for receiving an optical data storage medium containing a plurality of recording layers each of which is read by a different laser beam, one of said recording layers having a management area which stores information representing medium type of another recording layer in said medium, wherein said management area is provided on a recording layer read by a laser beam of which wavelength is shorter than another laser beam used to read said another recording layer;

a focusing device for focusing said laser beam on a recording layer in said medium; and

a photo detector for detecting a return laser beam from said medium and generating a data signal responsive thereto;

wherein said focusing device focuses said laser beam onto said management area to read information stored therein.

2. An optical data storage system comprising:

a laser light source for producing a laser beam;

an optical data storage medium containing a plurality of recording layers each of which is read by a different laser beam, one of said recording layers having a management area which stores information representing medium type of another recording layer in said medium, wherein said management area is provided on a recording layer read by a laser beam of which wavelength is shorter than another laser beam used to read said another recording layer;

a focusing device for focusing said laser beam on a recording layer in said medium; and

a photo detector for detecting a return laser beam from said medium and generating a data signal responsive thereto;

wherein said focusing device focuses said laser beam onto said management area to read information stored therein.