Optical disc and optical disc device

• US 8,837,266 B2
• Filed: 10/25/2013
• Issued: 09/16/2014
• Est. Priority Date: 02/16/2005
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Nakahara, Hironori, Takeshita, Nobuo, Ogawa, Masaharu
• Primary Examiner(s): TRAN, THANG V
• Application Number:
  US14/063,776
• Publication Number:
  US 20140050060A1
• Time in Patent Office: 326 Days
• Field of Search: None
• US Class Current: 369/53.2
• CPC Class Codes: G11B 20/1217 on discs
• CPC Class Codes: G11B 20/1262 with more than one format/standard, e.g. conversion from CD-audio format to R-DAT format
• CPC Class Codes: G11B 2007/0013 for carriers having multiple discrete layers
• CPC Class Codes: G11B 2020/1227 one layer of multilayer disc
• CPC Class Codes: G11B 7/007 Arrangement of the information on the record carrier, e.g. form of tracks , actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
• 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 7/013 for discrete information, i.e. where each information unit is stored in a distinct discrete location , e.g. digital information formats within a data block or sector
• CPC Class Codes: G11B 7/08511 with focus pull-in only
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: G11B 7/13 Optical detectors therefor
• CPC Class Codes: G11B 7/135 Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
• CPC Class Codes: G11B 7/1392 Means for controlling the beam wavefront, e.g. for correction of aberration optical systems for aberration correction per se G02B27/00
• CPC Class Codes: G11B 7/2403 Layers; Shape, structure or physical properties thereof
• CPC Class Codes: G11B 7/24038 Multiple laminated recording layers
• CPC Class Codes: G11B 7/24041 with different recording characteristics

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 medium comprising:

at least one recording layer, satisfying BD optical standard, having a track upon which a laser beam is focused during use; and

a management area provided on said at least one recording layer satisfying BD optical disc standard, said management area having recorded data representing if another type of recording layer is present in said medium,

wherein said recorded data represents if said another type of recording layer is present at a predefined depth of said medium, and said recorded data represents a depth at which said another type of recording layer should be present, and in case that said another type of recording layer is not present in said medium said recorded data indicates that said another type of recording layer is not present at said predefined depth,

said recorded data is provided only on the management area of the layer satisfying BD optical disc standard,

said recorded data represents absence of a recording layer by bit values of 00.

2. An optical data storage system comprising:

a laser light source for producing a laser beam;

an optical data storage medium according to claim 1;

a focusing device for focusing said laser beam on the layer satisfying the BD optical disc standard of 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.