ISO/IEC 13481:1993
(Main)Information technology — Data interchange on 130 mm optical disk cartridges — Capacity: 1 gigabyte per cartridge
Information technology — Data interchange on 130 mm optical disk cartridges — Capacity: 1 gigabyte per cartridge
Specifies two implementations: Type R/W (data to be written, read and erased many times) and type WO (having write once, read multiple functionality). Specifies the conditions for conformance testing and the reference drive; the environments in which the cartridges are to be operated and stored; the mechanical, physical and dimensional characteristics of the case and of the cartridge; the format of the information on the disk; the characteristics of the embossed information on the disk; the magneto-optical characteristics of the disk; the minimum quality of user-written data on the disk.
Technologies de l'information — Échange de données sur cartouches de disque optique de diamètre 130 mm — Capacité: 1 gigabyte par cartouche
General Information
Standards Content (Sample)
INTERNATIONAL
ISO/IEC
STANDARD
13481
First edition
1993-12-15
Information technology - Data
interchange on 130 mm Optical disk
cartridges - Capacity: 1 gigabyte per
cartridge
Technologies de I’informa tion - khange de donnees sur cartouches de
disque optique de diametre 130 mm - Capacitk 1 gigabyte par
cartouche
Reference number
ISO/IEC 13481:1993(E)
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ISOIIEC 13481: 1993 (E)
Contents
Page
1
Section 1 - General
scope
1
2 Conformance
21 . Optical Disk Cartridges
22 . Generating System
23 . Receiving System
2
Normative references
3
2
Defmitions
4
2
case
41 .
2
42 Cyclic Redundancy Check (CRC)
.
2
embossed mark
43 .
2
entrance surface
4.4
2
45 . E~or Correction Code (ECC)
2
46 . field
2
47 . formst
2
48 . groove
2
49 . interleaving
2
4.10 Kerr rotation
2
4.11 land and groove
2
4.12 mark
2
4.13 optical disk
2
4.14 Optical disk cartridge (ODC)
2
polarization
4.15
2
recording layer
4.16
@ ISO/IEC 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form or
by any means, electronie or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher
ISO/IEC Copyright Office l Case Postale 56 l CH- 12 11 Geneve 20 * Switzerland
Printed in Switzerland
ii
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ISo/rEc 13481:1993 (E)
Ree&Solomon code
4.17
rewitable optical disk
4.18
4.19 sector
4.20 Substrate
4.21 track
write-once functionality
4.22
zone
4.23
Conventions and notations
5
3
51 . Representation of numbers
3
52 . Names
3
6 List of acronyms
4
General description of the Optical disk cartridge
7
4
General requirements
8
4
81 . Environments
4
8.1.1 Testing environment
Operating environment
8.1.2
Storage environment
8.l.i
Transportation
8.1.4
82 . Temperature shock
83 . Safety requirements
84 . Flammability
9 Reference drive
5
91 . Optical System
7
92 . Optical beam
7
Read channels
93 .
7
Tracking
94 .
7
. Rotation of the disk
95
Section 2 - Mechanical and physical characteristics
10 Dimensions and mechanical characteristics of the case
8
General
10.1
8
10.2 Case drawings
8
Sides, reference axes and reference planes
10.3
8
Relationship of Sides A and B
10.3.1
8
10.3.2 Reference axes and case reference planes
. . .
111
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ISOAEC P3481:1993 (E)
8
Materials
10.4
9
10.5 MUS
9
Overall dimensions
10.6
9
10.7 Location hole
10
10.8 Alignment hole
10
10.9 Surfaces on reference planes P
11
10.10 Insertion slots and detent features
11
10.11 Gripper slots
12
10.12 Write-inhibit holes
12
10.13 Media Sensor holes
13
10.14 Head and motor window
13
10.15 Shutter
13
10.16 Slot for shutter opener
14
10.17 Shutter sensor notch
14
User label areas
10.18
15
11 Dimensional and physical characteristics of the disk
15
11.1 Dimensions of the disk
15
11.1.1 Outer diameter
15
11.1.2 Thickness
15
11.13 Clamping zone
15
11.1.4 Clearance zone
15
MasS
11.2
15
Moment of inertia
11.3
15
11.4 Imbahce
15
Axial deflec tion
11.5
15
11.6 Axial acceleration
15
11.7 Dynamit radial runout
16
11.8 Radial acceleration
.
16
11.9 Tilt
16
12 Drop test
16
13 Interface between disk and drive
16
13.1 Clamping technique
16
13.2 Dimensions of the hub
16
13.2.1 Outer diameter of the hub
16
Height of the hub
13.2.2
16
Diameter of the centre hole
13.2.3
16
13.2.4 Height of the top of the centre hole at diameter D,
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lso/lEc 13481:1993 (E)
16
13.2.5 Centring length at diameter D,
17
13.2.6 Chamfer at diameter D,
17
13.2.7 Chamfer at diameter D,
17
13.2.8 Outer diameter of the magnetizable ring
17
13.2.9 Inner diameter of the magnetizable ring
17
13.2.10 Thickness of the magnetizable material
17
13.2.11 Position of the top of the magnetizable ring relative to the disk reference plane
17
Magnetizable material
13.3
17
Clamping forte
13.4
17
13.5 Capture cylinder for the hub
18
13.6 Disk position in the operating condition
33
14 Characteristics of the Substrate
33
14.1 Index of refraction
33
Thickness
14.2
33
Section 3 - Format of information
33
15 Track geometry
33
15.1 Track shape
33
15.2 Direction of rotation
33
Track pitch
15.3
33
15.4 Track number
33
Track format
16
33
16.1 Formatted Zone
36
16.2 Control tracks
37
Control Track PEP Zone
16.3
37
Recording in the PEP Zone
16.3.1
37
Cross-track loss
16.3.2
38
16.3.3 Format of the tracks of the PEP Zone
41
16.4 Control Track SFP Zones
41
16.4.1 Duplicate of the PEP information
42
16.5 Media information
48
16.6 System Information
49
16.7 Unspecified content
49
Requirements for interchange of a user-recorded cartridge
16.8
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ISODEC 13481:1993 (E)
49
16.8.1 Requirements for reading
49
Requirements for writing and erasing
16.8.2
49
Seetor formst
17
51
17.1 Seetor Mark (SM)
52
17.2 VFO areas
52
17.3 Address Mark (AM)
52
17.4 ID and CRC
53
Postamble (PA)
17.5
53
Offset Detection Flag (ODF)
17.6
53
17.7
GaP
53
17.8
fm3
53
17.9 Auto Laser Power Control (ALPC)
53
17.10
SYN
53
17.11 Data field
53
17.11.1 Userbytes
53
17.11.2 CRC and ECC
54
17.11.3 Bytes for control information
54
17.11.4 Last bytes of the Data field of the 512.byte sector formst
54
17.11.5 Resync
54
17.12 Buffer
54
Recording code
18
54
19 Defect management
55
Media initialization
19.1
55
Media initialization with certification
19.1.1
55
19.1.2 Media initialization without certification
55
Write and read procedure
19.2
56
Layout of the User Zone
19.3
57
19.3.1 Disk Definition Structure (DDS)
58
19.3.2 Primary Defect List (PDL)
59
19.3.3 Secondary Defect List (SDL)
60
19.3.4 Zone Structure Table (ZST)
62
Section 4 - Characteristics of embossed information
62
20 ZCAV format
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ISo/IEc 1348lr1993 (E)
20.1 Tracking 62
20.2 Characteristics of pre-recorded information 62
62
20.2.1 Groove-related Signals
63
20.2.2 Properties of pre-recorded marks
the read characteristics 64
20.2.3 Parameters of
65
Section 5 - Characteristics of the recording layer
21 Characteristics of the recording layer 65
21.1 Test conditions 65
65
21.1.1 General
65
21.1.2 Read conditions
65
21.1.3 Write conditions
21.1.4 Erase conditions 66
21.2 Baseline reflectance 67
67
21.2.1 General
67
21.2.2 Actuai value
67
21.2.3 Requirement
67
21.3 Magneto-Optical recording in the User Zone
21.3.1 Resolution 67
21.3.2 Imbalance of magneto-Optical Signal 68
68
21.3.3 Figure of merit for magneto-Optical Signal
68
21.3.4 Narrow-band signal-to-noise ratio
21.3,5 Cross-t& ratio 69
69
21.3.6 Esse of erasure
Annexes
70
A - Definition of write and erase pulse width
71
B - Measurement of figure of merit
72
C - Values to be implemented in future standards
D - Pointer Felds 73
74
E - CRC for ID fields
F - Interleave, CRC, ECC, Resync for the Data field 75
81
G - Seetor retirement guidelines
82
H - Office environment
83
J - Transportation
Vii
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ISOIIEC 13481:1993 (E)
K - Requirements for interchange 84
86
L - SCSI Logical Block to Physical Seetor Mapping
89
M - Derivation of the operating climatic environment
N - Air cleanliness class 100 000 93
P - Guidelines for using ODCs of Type W/O 95
. . .
Vll1
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ISO/IEC 13481: 1993 (E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the
specialized System for worldwide standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal with
particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other
international organizations, govemmental and non-govemmental, in liaison with ISO and IEC, also take part in the work.
In the field of information technology, ISO and IEC have established a joint technical committee ISO/IEC JTC 1. Draft
International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
International Standard ISO/IEC 13481 was prepared by the European Computer Manufacturers Association (as Standard
ECMA-183) and was adopted, under a special “fast-track procedure”, by Joint Technical Committee ISO/IEC JTC 1,
Information technology, in parallel with its approval by national bodies of ISO and IEC.
Annexes A, B, D, E, F, K, L and N form an integral part. of this International Standard. Annexes C, G, H, J, M and P are for
information only.
Patents
During the preparation of the ECMA Standard, information was gathered on Patents upon which application of the Standard
might depend. Relevant Patents were identified as belonging to the MAXOPTIX Corporation. However, neither ECMA nor
ISO/IEC tan give authoritative or comprehensive information about evidente, validity or scope of patent and like rights. The
patent holders have stated that licences will be granted under reasonable and non-discriminatory terms. Communications on
this subject should be addressed to
MAXOPTIX CORPORATION
2520 Junction Avenue
SAN JOSE -CA 95 134
USA
ix
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ISOIIEC 13481:1993 (E)
Introduction
This International Standxd specifies the characteristics of 130 mm Optical Disk Cartridges (ODC) with a capacity of 1 Gbyte
per cartridge. This International Standard specifies two related but different implernentations of such cartridges, viz.
Type R/W Provides for data to be written, read, and erased many times over the whole of both recording surfaces of the
disk using the thermo-magnetic and magneto-Optical effects.
Type WO Provides write once, read multiple functionality on the whole of both disk surfaces using the thermo-magnetic
and magneto-Optical effects.
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INTERNATIONAL STANDARD ISO/IEC 13481:1993 (E)
Data interchange on 130 mm Optical disk cartridges -
Information technology -
Capacity: 1 gigabyte per cartridge
Section 1 - General
1 scope
This International Standard specifies the characteristics of 130 mm Optical disk cartridges (ODCs) with a capacity of
1 Gigabyte per cartridge. It specifies two related, but different implernentations of such cartridges:
Type R/W Provides for data to be written, read and erased many times over the whole of both recording surfaces of the
disk using the thermo-magnetic and magneto-Optical effects.
Provides write once, read multiple functionality on both disk surfaces using the thermo-magnetic and magneto-
Type WO
Optical effects.
This International Standard specifies:
-
the conditions for conformance testing and the reference drive;
-
the environments in which the cartridges are to be operated and stored;
-
the mechanical, physical and dimensional characteristics of the case and of the cartridge, so as to provide mechanical
interchangeability between data processing Systems;
-
the format of the information on the disk, both embossed and user-written, including the physid disposition of the
tracks and sectors, the error correction Codes, and the modulation method used;
-
the characteristics of the embossed information on the disk;
- the magneto-Optical characteristics of the disk, enabling processing Systems to write data onto the disk;
-
the minimum quality of user-written data on the disk, enabling data processing Systems to read data from the disk.
It also provides for interchange between Optical disk drives. Together with a Standard for volume and file structure, it
provides for full data interchange between data processing Systems. Interchange involves the ability to write, read and erase
data without introducing any error.
2 Conformance
21 Optical disk cartridges
.
An ODC claiming conformance with this International Standard shall specify its Type. It shall conform to this International
Standard if it meets all mandatory requirements specified herein for that Type.
2.2
Generating System
A Claim of conformance with this International Standard shall specify which Type(s) is (are) supported. A System generathg
an ODC for interchange shall be entitled to Claim conformance with this Standard if it meets all mandatory requirements of
this Standard for the Type(s) specified.
23 . Receiving System
A Claim of conformance with this International Standard shall specify which Type(s) is (are) supported.
A System receiving an ODC for interchange shall be entitled to Claim conformance with this International Standard if it is
able to handle any recording made on the cartridge according to 2.1 on the Type(s) specified.
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ISODEC WM:1993 (E)
3 Normative references
The following Standards contain provisions which, through reference in this text, constitute provisions of this International
Standard. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and Parties to
agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent
editions of the Standards listed below. Members of EC and ISO maintain registers of currently vaIid International Standards.
ISO 683-13:1986, Heat treatable steels, alloy steels andfree-cutting steels - Part 13: Wrought stainless steels.
IEC 950: 1991, Safety of information technology equipment, including electrical business equipment.
Definitions
4
For the purposes of this International Standard the following definitions apply.
4.1 case: The housing for an Optical disk, that protects the disk and facilitates disk interchange.
4.2 Cyclic Reduodancy Check (CRC): A method for detecting errors in data.
4.3 embossed markt A mark so formed as to be unalterable by magneto-Optical means.
4.4 entrance surface: The surface of the disk on to which the Optical beam frst impinges.
4.5 Error Correction Code (ECC): An error-detecting Code designed to correct certain kinds of errors in data.
4.6 field: A subdivision of a sector.
4.7 format: The arrangement or layout of information on the disk.
4.8 groove: See 4.11.
4.9 interleaving: The process of allocating the physical sequence of units of data so as to render the data more immune to
burst errors.
the plane of polarization ofan Optical reflection from the recording as
4.10 Kerr rotation: The rotation of lqfer,
upon
caused by the magneto-Optical effect.
any information, and used to defme
4.11 land and groove: A trench-like feature of the disk, applied before the recording of
which it is paired to form a track.
the track location. The groove is located nearer to the entrance surface than the land with
4.12 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 tan be sensed by the Optical System. The Pattern of marks represents the data on the disk.
NOTE - Subdivisions of a sector which arc named “maric” w not marks in the sense of this defmition.
4.13 Optical disk: A disk that will accept and retain information in the form of marks in a recording hyer, that tan be read
with an Optical beam.
4.14 Optical disk cartridge (ODC): A device consisting of a case containing an optical disk.
4.15 polarization: The direction of polarization of an Optical beam is the direction of the electric vector of the beam.
NOTE - Tbc 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 eilipse in the clockwise sense.
4.16 recording layer: A layer of the disk on, or in, which data is written during manufacture and/or use.
An error detection and/or correction Code which 1s particularly suited to the correction of errors
4.17 Reed-Solomon
strongly correlated.
which occur in bursts or are
disk in which the data in specified areas tan be written, erased and rewritten by an
4.18 rewritable Optical disk: An Optical
optical beam.
independently
4.19 sector: The smallest addressable part of a track in the i nformation zone of a disk that tan be accessed of
other addressable parts of the Zone.
4.20 Substrate: A transparent layer of the d .isk, provided for the mechanical support of the recording layer, through which
the optical beam accesses the recordin g layer.
2
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ISODEC 13481:1993 (E)
4.21 track: The path which is to be followed by the focus of the Optical beam during one revolution of the disk.
4.22 write-once functionality: A disk with write-once functionality tan be initialized and written once in specified areas
and read many times by an Optical beam. Erasing of data in these specified areas is not permitted.
4.23 zoae: An annular area of the disk.
5 Conventions and notations
51 Representation of numbers
.
-
A measured value is rounded off to the least significant digit of the corresponding specified value. It implies that a
specified value of 126 with a positive tolerante of +O,Ol, and a negative tolerante of -0,02 allows a range of measured
values from 1,235 to 1,275.
- Letters and digits in parentheses represent numbers in the hexadecimal notation.
-
The setting of a bit is denoted by ZERO or ONE.
-
Numbers in binary notation and bit combinations are represented by strings of ZEROS and ONEs.
-
Numbers in binary notation and bit combinations are shown with the most significant bit to the left.
- Bit combinations are shown with the most significant bit to the left.
- Negative values of numbers in binary notation are expressed in TWO’s complement notation.
- In each field the data is recorded so that the most significant byte (byte 0) is recorded fust. Within each byte the least
significant bit is numbered 0 and is recorded last, the most significant bit (numbered 7 in an 8-bit byte) is recorded first.
This Order of recording applies also to the data input of the Error Detection and Correction circuits and to their output.
52 . N2UTW-S
The names of entities, e.g. specific tracks, fields, etc., are given with a capital initial.
6 List of acronyms
Address Mark
ces Continuous Composite Servo (tracking method)
CRC Cyclic Redundancy Code
DDS Disk Definition S tructure
DMA Defect Management Area
DMP Defect Management Pointers
Error Correction Code
ECC
ID Identifier
Logical Block Address
LBA
LDC Lang Distance Code
LSB Least Significant Byte
MSB Most Significant Byte
ODC Optical Disk Cartridge
ODF Offset Detection Flag
PA Postamble
PDL Primar-y Defect List
PEP Phase Encoded Part of the Control Tracks
Run Length Limited (Code)
~W7)
R-S Reed-Solomon
SCSI SmaIl Computer Systems Interface
SDL Secondary Defect List
SFP Standard Formatted Part of the Control Tracks
SM Seetor Mark
VFO Variable Frequency Oscillator
ZCAV Zoned Constant Angular Velocity
---------------------- Page: 13 ----------------------
ISOIIEC 13481: 1993 (E)
ZST Zone Structure Table
7 General description of the Optical disk cartridge
The Optical disk cartridge whichis the subject of this International Standard consists of a case containing an Optical disk.
The case is a protective enclosure for the disk. It has access windows covered The windows are automatically
bY a
the drive when the cartridge is inserted i nto it.
uncovered by
The Optical disk is recordable on both sides. Data tan be written onto the disk as mark in the form of magnetic domains in the
recording layer and tan be erased from it with a focussed Optical beam, using the thermo-magnetic effect. The data tan be
read with a focussed Optical beam, using the magneto-Optical Kerr effect. The beam accesses the recording layer through the
transparent Substrate of the disk.
from one side only. To gain access side of a disk, the
The disk is intended for use in a drive with Optical access
must be reversed before insertion into the drive.
cartridge
8 General requirements
81 . Environments
8.1.1 Testing environment
is the environment where the air immediately surrounding the Optical disk cartridge shall have the
The test environment
following properties
:23"Czt2"C
temperature
relative humidity (RH) : 45 % to 55 %
:6OkPato106Wa
atmospheric pressure
air cleanliness : Class 100 000 (see annex N)
No condensation on or in the ODC shall occur. Before testing, the Optical disc cartridge shall be conditionecl in this
environment for 48h min. It is recommended that, before testing, the entrance surface of the Optical disk be cleaned according
to the instructions of the manufacturer of the disk.
Unless otherwise stated, all tests and measurements shall be made in this testing environment.
8.1.2 Operating environment
This International Standard requires that an Optical disk cartridge which meets all requirements of this International
Standard in the specified test environment provides data interchange over the specified ranges of environmental Parameters
in the operating environment.
The operating environment is the environment where the air immediately surrounding the Optical disk cartridge shall have
the following properties
temperature : 5 OC to 55 OC
relative humidity : 3 % to 85 %
absolute humidity : 1 g/m3 to 30 g/m3
atmospheric pressure :6OkPatoMkPa
temperature gradient : 0 OC /h max.
relative humidity gradient : 10 % /h max.
air cleanliness : Office environment (sec annex H)
magnetic field strength at the recording layer
for any condition under which a beam is in focus : 32 000 A/m max.
magnetic field strength at the recording layer
during any other condition. : 48 000 A/m max.
No condensation on or in the Optical disk cartridge shall be allowed to occur. If an Optical disk cartridge has been exposed to
conditions outside those specified in this clause, it shall be acclimatized in an allowed operating environment for at lmt 2 h
before use (see also annex M).
4
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ISO/IEC 13481: 1993 (E)
8.1.3 Storage environment
The Optical disk cartridge without any protective enclosure shall not be stored in an environment outside the range allowed
for storage. The storage environment is defined as an environment where the air immediately surrounding the optical disk
cartridge shall have the following properties
temperature : -10 OC to 55 OC
relative humidity : 3 % to 90 %
absolute humidity : 1 g/m3 to 30 g/m3
atmospheric pressure AOkPato106kPa
temperature gradient : 15OC/hmax.
relative humidity gradient : lO%/hmax.
air cleanliness : Office environment (see annex H)
magnetic field strength at the recording layer :48OOOA/mmax.
No condensation on or in the Optical disk cartridge shall occur.
8.1.4 Transportation
This International Standard does not specify requirements for transportation; guidance is given in annex P.
82 . Temperature shock
The Optical disk cartridge shall withstand a temperature shock of up to 20°C when inserted into, or removed from, the drive.
Safety requirements
83 .
The cartridge shall satisfy the safety requirements of IEC 950, when used in its intended manner or in any foreseeable use in
an information processing System.
84 . Flammability
The cartridge and its components shall be made from materials that comply with the flammability class for HB materials, or
as specified in IEC 950.
9 Reference Drive
The Reference Drive is a collection of several critical components which have well defined properties and which are used to
test write, read and erase Parameters of the disk for conformance to this International Standard. The critical components vary
from test to test. This clause gives an outline of all components; components critical for tests in specific clauses only are
specified in these clauses.
91 . Optical System
The basic set-up of the Optical System of the Reference Drive used for measuring the write, read and erase Parameters is
shown in figure 1. Different components and locations of components are permitted, provided that the performante remains
the same as that of the set-up in figure 1. The Optical System shall be such that the detected light reflected from the entrance
surface of the disk is minimized so as not to influence the accuracy of the measurements.
---------------------- Page: 15 ----------------------
ISOIIEC 13481: 1993 (E)
1
1
6
K
3
t
t
:
1
t
I
t
I
M
t
I
t
t
1
l
t
t
1
1
:
I
t
04
A Laser diode
G Optical disk
B Collimator lens H
Optical half-wave plate
C Optical shaping prism 1
Optical Phase retarder
Ch.1 Channel 1 J
Polarizing beam Splitter
Ch.2 Charme1 2
Photodiode for Channels 1 and 2
Kl 7K2
D Polarizing Beam splitter Split Photodiode for focus and tracking servo
K3
E Leaky beam Splitter d.c.-coupled amplifier
Ll ,L2
F Objective lens M Tracking Channel
Figure 1 - Optical System of the Reference Drive
In the absence of polarization changes in the disk, the polarizing beam Splitter J shall be aligned to make the Signal of
detector Kl equal to that of detector Kz. The direction of polarization in this case is called the neutral direction. The Phase
retarder I shall be adjusted such that the Optical System does not have more than 2,5O Phase retardation between the neutral
polarization and the polarization perpendicular to it. This position of the retarder is called the neutral Position.
The Phase retarder tan be used for the measurement of the narrow-band signal-to-noise ratio.
The beam Splitter J shall have a p-s intensity reflectance ratio of at least 100.
The intensity reflectance R, of the beam Splitter E from F to H for the neutral polarization direction shall be nominally 0,lO.
The reflectance R, for the polarization perpendicular to the neutral direction shall be nominally 0,99. The actual value of R,
shall not be smaller than 0,95.
The imbalance of the magneto-Optical Signal is specified for the beam Splitter with nominal reflectances. If the measurement
is made on a drive with reflectances R,’ and R,’ for the beam Splitter E, then the measured imbalance shall be multiplied by
Rs R’p
Rp R’s
d
to make it correspond to the nominal beam Splitter E.
6
---------------------- Page: 16 ----------------------
ISO/IEC 13481:1993 (E)
The output of Channel 1 is the sum of the cunrents through photo-diodes Kl and KZ, and is used for reading embossed marks.
The output of Charme1 2 is the differente between photo-diode cunrents, and is used for reading user-wr&en marks with the.
magneto-optical effect.
92 . Optical beam
The focussed Optical beam used for writing, reading and erasing data shall have the following properties
: Test environment
Environment
+ 15
: 780 nm- 10 1~n
Wavelength (h)
Wavelength (h) divided by the numerical
aperture (NA) of the objective lens : iYNA = 1,423 Fm & 0,023 um
Filling of the lens aperture (D/W) where D is
the diameter of the lens aperture and W is
: 1,0 max.
the l/e2 beam diameter of the Gaussian beam
Variante of the wave front of the Optical
beam at the recording layer : h2/180 max.
Polarization : Parallel to the track
. Read Channels
93
Two read Channels shall be provided to generate Signals from the marks in the recording layer. Channel 1 shall be used for
reading the embossed marks, using the diffraction of the Optical beam by the marks. Channel 2 shall be used for reading the
user-written marks, using the rotation of the polarization of the Optical beam due to the magneto-Optical effect of the marks.
The read amplifiers after the photo-detectors in Channel 1 and Channel 2 shall have a flat response within & 1 dB from
100 kHz to 11,6 MHz.
94 . Tracking
The Tracking Charme1 of the drive provides the tracking error Signals to control the servos for the axial and radial tracking of
the Optical beam. The method of generating the axial tracking error is not specified for the Reference Drive. The radial
tracking error is generated by a Split Photodiode detector in the Tracking Channel. The division of the diode runs parallel to
the image of the tracks on the diode.
9s . Rotation of the disk
The spindle shall position the disk as specified in 13.6. It shall rotate the disk at 30,O Hz i: 0,3 Hz. The direction shall be
counter-clockwise when viewed from the objective iens.
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Iso/rEc 13481:1993 (E)
Section 2 - Mechanical and physical characteristics
10 Dimensions and mechanid characteristics of the case
10.1 General
The case shall be a rigid, protective enclosure of rectangular shape and include a shutter which uncovers access windows
upon insertion into the drive, and automatically covefs them upon removal from the drive. The case shall have means for
positioning and identifying the cartridge, and write-inhibit holes.
The dimensions of the inside of the case are not specified in this International Standard, but are determined by the movement
of the disk inside the case allowed by 13.5 and 13.6.
10.2 Case drawings
The case is represented schematically by the following drawings.
- Figure 2 Shows the hub dimensions.
drawing of Side A of the case in isometric ferm, with the identifie
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