ISO/IEC 15041:1997 情報技術— 90 mm光ディスクカートリッジでのデータ交換—容量：カートリッジあたり640Mバイト | ページ 6

4.1

band

Part of the Data Zone comprising a fixed number of consecutive physical tracks.

4.2

case

The housing for an optical disk, that protects the disk and facilitates disk interchange.

4.3

Channel bit

The smallest element for the representation of data on a disk. It is recorded as either a space or a mark. Twelve channel bits are used to represent eight input bits.

4.4

clamping zone

The annular part of the disk within which the clamping force is applied by the clamping device.

4.5

control track

A track containing the information on media parameters and format necessary for writing, reading and erasing the remaining tracks on the optical disk.

4.6

Cyclic Redundancy Check

CRC

A method for detecting errors in data.

4.7

defect management

A method for handling the defective areas on the disk.

4.8

DOW disk

A Magneto-Optical disk in which the new data can be written directly over old data by modulating the laser-intensity without reversing the magnetic field direction.

4.9

disk reference plane

A plane defined by the perfectly flat annular surface of an ideal spindle onto which the clamping zone of the disk is clamped, and which is normal to the axis of rotation.

4.10

embossed mark

A mark so formed as to be unalterable by magneto-optical means.

4.11

entrance surface

The surface of the disk on to which the optical beam first impinges.

4.12

Error Correction Code

ECC

An error-detecting code designed to correct certain kinds of errors in data.

4.13

field

A subdivision of a sector.

4.14

format

The arrangement or layout of information on the disk.

4.15

fully embossed disk

An optical disk in which all data fields in the Data Zone are embossed.

4.16

fully rewritable disk

An optical disk in which the data in specified areas can be rewritten by an optical beam.

4.17

groove

4.18

hub

The central feature on the disk which interacts with the spindle of the disk drive to provide radial centring and the clamping force.

4.19

interleaving

The process of allocating the physical sequence of units of data so as to render the data more immune to burst errors.

4.20

Kerrrotation

The rotation of the plane of polarization of an optical beam upon reflection from the recording layer, as caused by the magneto-optical effect.

4.21

land and groove

A trench-like feature of the disk, applied before the recording of any information, and used to define the track location. The groove is located nearer to the entrance surface than the land with which it is paired to form a track.

4.22

logical track

Either 25 consecutive sectors for disks with 512-byte sectors or 17 consecutive sectors for disks with 2 048-byte sectors in one or more physical tracks. The first sector of each logical track is assigned sector number 0.

4.23

logical ZCAV

A disk format requiring Zoned Constant Angular Velocity operation and with tracks n in the Data Zone all being logical tracks.

4.24

mark

A feature of the recording layer which may take the form of a magnetic domain, a pit, or any other type or form that can be sensed by the optical system. The pattern of marks represents the data on the disk.

Note 1 to entry: Subdivisions of a sector which are named 'mark' are not marks in the sense of this definition.

4.25

optical disk

A disk that will accept and retain information in the form of marks in a recording layer, that can be read with an optical beam.

4.26

optical disk cartridge

ODC

A device consisting of a case containing an optical disk.

4.27

partially embossed disk

An optical disk which contains both rewritable and embossed data fields in the Data Zone.

4.28

physical track

The path which is followed by the focus of the optical beam during one revolution of the disk.

4.29

physical track group

A fixed number of consecutive physical tracks in the Data Zone.

4.30

pitch

The distance between adjacent physical track centrelines, measured in a radial direction.

4.31

polarization

The direction of polarization of an optical beam is the direction of the electric vector of the beam.

Note 1 to entry: The plane of polarization is the plane containing the electric vector and the direction of propagation of the beam. The polarization is right-handed when to an observer looking in the direction of propagation of the beam, the end-point of the electric vector would appear to describe an ellipse in the clockwise sense.

4.32

read power

The optical power, incident at the entrance surface of the disk, used when reading.

Note 1 to entry: It is specified as a maximum power that may be used without damage to the written data. Lower power may be used provided that the signal-to-noise ratio and other requirements of this International Standard are met.

4.33

recording layer

A layer of the disk on, or in, which data is written during manufacture and/or use.

4.34

Reed-Solomon code

An error detection and/or correction code which is particularly suited to the correction of errors which occur in bursts or are strongly correlated.

4.35

sector

The smallest addressable part of a track in the Information Zone of a disk that can be accessed independently of other addressable parts of the zone.

4.36

space

The area between marks along the track.

4.37

spindle

The part of the disk drive which contacts the disk and/or hub.

4.38

substrate

A transparent layer of the disk, provided for mechanical support of the recording layer, through which the optical beam accesses the recording layer.

4.39

zone

An annular area of the disk.