Information technology — Data interchange on 300 mm optical disk cartridges of type WORM (Write Once Read Many) using irreversible effects — Capacity: 30 Gbytes per cartridge

This International Standard specifies the characteristics of a 300 mm optical disk cartridge (ODC) of Type WORM (Write Once Read Many) using irreversible effects, with a capacity of 30 Gbytes. This WORM ODC's uses writing effects that are inherently irreversible. Written marks cannot be erased and attempted modifications of the written marks are detectable. 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 cartridge, so as to provide mechanical interchange ability between data processing systems; − the format of the information on the disk, both pre-written and user-written, including the physical disposition of the tracks and sectors, the error correction codes, the modulation methods used; − the characteristics of the prerecorded information on the disk; − the recording 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. This International Standard 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.

Technologies de l'information — Échange de données sur cartouches de disque optique de 300 mm de type WORM (écriture unique et lectures multiples) avec effets irréversibles — Capacité: 30 Gbytes par cartouche

General Information

Status
Withdrawn
Publication Date
05-Dec-2001
Withdrawal Date
05-Dec-2001
Current Stage
9599 - Withdrawal of International Standard
Completion Date
17-Nov-2021
Ref Project

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ISO/IEC 20162:2001 - Information technology -- Data interchange on 300 mm optical disk cartridges of type WORM (Write Once Read Many) using irreversible effects -- Capacity: 30 Gbytes per cartridge
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INTERNATIONAL ISO/IEC
STANDARD 20162
First edition
2001-12-01

Information technology — Data interchange
on 300 mm optical disk cartridges of type
WORM (Write Once Read Many) using
irreversible effects — Capacity: 30 Gbytes
per cartridge
Technologies de l'information — Échange de données sur cartouches de
disque optique de 300 mm de type WORM (écriture unique et lectures
multiples) avec effets irréversibles — Capacité: 30 Gbytes par cartouche




Reference number
ISO/IEC 20162:2001(E)
©
ISO/IEC 2001

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ISO/IEC 20162:2001(E)
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©  ISO/IEC 2001
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body
in the country of the requester.
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ii © ISO/IEC 2001 – All rights reserved

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ISO/IEC 20162:2001(E)
Contents Page
Section 1 — General 1
1 Scope 1
2 Conformance 1
2.1 Optical Disk Cartridge (ODC) 1
2.2 Generating System 1
2.3 Receiving System 1
2.4 Compatibility statement 1
3 Normative references 1
4 Terms and definitions 1
4.1 case 1
4.2 Clamping Reference Area 1
4.3 Clamping Zone 2
4.4 Cyclic Redundancy Check (CRC) 2
4.5 Data Zone 2
4.6 defect management 2
4.7 Disk Reference Plane 2
4.8 entrance surface 2
4.9 Error Correction Code (ECC) 2
4.10 format 2
4.11 hub 2
4.12 interleaving 2
4.13 Logical Sector 2
4.14 Logical Block Address 2
4.15 mark 2
4.16 mark edge 2
4.17 mark edge recording 2
4.18 optical disk 2
4.19 optical disk cartridge (ODC) 2
4.20 polarization 2
4.21 prerecorded mark 2
4.22 read power 2
4.23 recording layer 2
4.24 Reed-Solomon code 2
4.25 space 2
4.26 spindle 2
4.27 substrate 2
4.28 track 2
4.29 track pitch 2
4.30 write-inhibit hole 2
5 Conventions and notations 2
5.1 Representation of numbers 2
5.2 Names 3
6 List of acronyms 3
7 General description of the optical disk cartridge 3
8 General requirements 3
8.1 Environments 3
8.1.1 Test environment 3
8.1.2 Operating environment 4
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ISO/IEC 20162:2001(E)
8.1.3 Storage environment 4
8.1.4 Transportation 4
8.2 Temperature shock 4
8.3 Safety requirements 4
8.4 Flammability 5
9 Reference Drive 5
9.1 Optical system 5
9.2 Optical beam 5
9.3 Read Channel 5
9.4 Tracking 5
9.5 Rotation of the disk 5
Section 2 — Mechanical and physical characteristics 7
10 Dimensional and physical characteristics of the case 7
10.1 General description of the case 7
10.2 Relationship of Sides A and B 7
10.3 Reference axes of the case 7
10.4 Case drawings 7
10.5 Dimensions of the case 7
10.5.1 Overall dimensions 7
10.5.2 Locator slots 8
10.5.3 Side A / B indicator holes 8
10.5.4 Side A / B indicator labels 9
10.5.5 Insertion slots and detent features 9
10.5.6 Gripper slots and gripper notches 10
10.5.7 Write-inhibit hole 11
10.5.8 Hub aperture and head window 11
10.5.9 Shutters 11
10.5.10 Shutter opener features 11
10.5.11 User label areas 12
10.5.12 Bar code area 12
10.6 Mechanical characteristics 12
10.6.1 Materials 12
10.6.2 Mass 12
10.6.3 Edge distortion 12
10.6.4 Compliance 12
10.6.5 Shutter opening force 12
10.7 Drop test 12
11 Dimensional, mechanical and physical characteristics of the disk 13
11.1 General description of the disk 13
11.2 Reference axis and plane of the disk 13
11.3 Dimensions of the disk 13
11.3.1 Hub dimension 13
11.4 Mechanical characteristics 15
11.4.1 Material 15
11.4.2 Mass 15
11.4.3 Moment of inertia 15
11.4.4 Imbalance 15
11.4.5 Axial deflection 15
11.4.6 Axial acceleration 15
11.4.7 Radial runout 15
11.4.8 Radial acceleration 16
11.4.9 Tilt 16
11.5 Optical characteristics 16
11.5.1 Index of refraction 16
11.5.2 Thickness 16
11.5.3 Birefringence 16
11.5.4 Reflectance 16
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ISO/IEC 20162:2001(E)
12 Interface between cartridge and drive 17
12.1 Clamping method 17
12.2 Clamping force 17
12.3 Capture cylinder 17
12.4 Disk position in the operating condition 17
Section 3 — Format of information 32
13 General description 32
14 Track format 32
14.1 Track definition 32
14.2 Direction of track spiral 32
14.3 Track pitch 32
14.4 Track numbering 32
14.5 Track layout 32
14.6 Segment format 32
14.7 Servo Field format 32
14.8 Address format 34
14.9 Recordable Field format 34
15 Zone organization 35
15.1 Logical Sector format 35
15.2 CRC and ECC bytes 36
15.3 User Area - Format of Data Zones 36
15.3.1 Detailed format of Data Zones 37
16 Recording code 37
16.1 Termination Field 37
16.2 Data recording method for the RLL(1,7) Code 38
17 Defect Management 38
17.1 Defective Sectors recorded in the SDI 38
17.2 Reading and writing Procedure 38
17.3 Format of the Relocation Area 38
17.4 Format of the Dynamic Relocation Maps Sectors 38
18 Prerecorded Information 39
18.1 Prerecorded Information definition 39
18.2 Reserved regions 39
18.3 Specific Disk Information (SDI) 39
18.3.1 SDI Sector allocation 39
18.3.2 SDI content 40
18.4 Read Focus Optimization (RFO) Tracks 40
Section 4 — Characteristics of Prerecorded Information 41
19 Method of testing 41
19.1 Environment 41
19.2 Use of the Reference Drive 41
19.2.1 Optics and mechanics 41
19.2.2 Read power 41
19.2.3 Read channel 41
19.2.4 Tracking 42
19.3 Definition of signals 42
20 Prerecorded Information signal requirements 43
20.1 Modulation Depth of preformatted marks 43
20.2 Ratio of minimum and maximum Clock Mark signal amplitude with open tracking loop 43
20.3 Clock Mark jitter 43
20.4 Relative tangential displacement of preformatted marks 43
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ISO/IEC 20162:2001(E)
20.5 Variation of QWT Marks signal amplitude 43
20.6 Track pitch 43
20.7 Radial runout 43
20.8 Radial accelerations 43
20.9 Tracking Gain 43
Section 5 — Characteristics of the recording layer 44
21 Method of testing 44
21.1 Test Regions 44
21.2 Environment 44
21.3 Use of the Reference Drive 44
21.3.1 Optics and mechanics 44
21.3.2 Read power 44
21.3.3 Read Channel 44
21.3.4 Tracking 44
21.4 Write conditions 44
21.4.1 Write pulse 44
21.4.2 Nominal Write Power P 45
w nom
21.4.3 Nominal Write Power P determination 45
w nom
21.4.4 Writing Power boosts and droops 45
21.4.5 Write Media Profile 45
22 Write characteristics 45
22.1 Signal modulation 45
22.2 Signal Resolution 45
22.3 Write power margin 45
Section 6 — Characteristics of user data 46
23 Method of testing 46
23.1 Environment 46
23.2 Use of the Reference Drive 46
23.2.1 Optics and mechanics 46
23.2.2 Read power 46
23.2.3 Read channel 46
23.2.4 Error correction 46
23.2.5 Tracking 46
24 Minimum quality of a Sector 46
24.1 Servo Fields 46
24.2 User-written data 47
24.3 Pre-written data 47
25 Data interchange requirements 47
25.1 Tracking 47
25.2 User-written and pre-written data 47
25.3 Quality of disk 47
Annexes
A - Air cleanliness class 100 000 48
B - Edge distortion test 49
C - Compliance test 51
D - Test method for measuring the adsorbent force of the hub 54
E - Creeping One of Four Code (COF) 56
F - PBA, LBA formats 57
G - Interleave, CRC, ECC 59
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ISO/IEC 20162:2001(E)
H - Content of SDI Sectors 61
J - SISIC (Selective Inter Symbol Interference Cancellation) data detection 64
K - Requirements for interchange 66
L - Shape and sequence of write pulses for testing 68
M - Office environment 69
N - Derivation of the operating climatic environment 70
P - Transportation 75
Q - Track deviation measurement 76


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ISO/IEC 20162:2001(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, governmental and non-governmental, 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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
The main task of the joint technical committee is to prepare International Standards. 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.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights.
ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 20162 was prepared by ECMA (as ECMA-317) 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 to L form a normative part of this International Standard. Annexes M to Q are for information only.

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INTERNATIONAL STANDARD ISO/IEC 20162:2001(E)

Information technology — Data interchange on 300 mm optical disk cartridges of
type WORM (Write Once Read Many) using irreversible effects —
Capacity: 30 Gbytes per cartridge
Section 1 — General
1 Scope
This International Standard specifies the characteristics of a 300 mm optical disk cartridge (ODC) of Type WORM (Write
Once Read Many) using irreversible effects, with a capacity of 30 Gbytes. This WORM ODC's uses writing effects that are
inherently irreversible. Written marks cannot be erased and attempted modifications of the written marks are detectable.
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 cartridge, so as to provide mechanical interchange ability
between data processing systems;
− the format of the information on the disk, both pre-written and user-written, including the physical disposition of the tracks
and sectors, the error correction codes, the modulation methods used;
− the characteristics of the prerecorded information on the disk;
− the recording 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.
This International Standard 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.
2 Conformance
2.1 Optical Disk Cartridge (ODC)
An Optical Disk Cartridge shall be in conformance with this International Standard if it meets the mandatory requirements
specified herein.
2.2 Generating System
A generating system shall be in conformance with this International Standard if the ODC it generates is in accordance with 2.1.
2.3 Receiving System
A receiving system shall be in conformance with this International Standard if it is able to handle an ODC according to 2.1.
2.4 Compatibility statement
A claim of conformance by a generating or receiving system with this International Standard shall include a statement listing
any other ECMA or International Optical Disk Cartridge standard(s) supported by the system for which conformance is
claimed. This statement shall specify the number of the standard(s), including, where appropriate, the ODC Type(s), or the
Types of side, and whether support includes reading only or both reading and writing.
3 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this
International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not
apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the
normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO/IEC 646:1991 Information technology — ISO 7-bit coded character set for information interchange
IEC 60950-1:2001 Information technology equipment — Safety — Part 1: General requirements
4 Terms and definitions
For the purpose of this International Standard, the following terms and definitions apply.
4.1 case: The housing for an optical disk, that protects the disk and facilitates disk interchange.
4.2 Clamping Reference Area: The area of the Clamping Zone used to define the Disk Reference Plane.
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ISO/IEC 20162:2001(E)
4.3 Clamping Zone: The area of the disk within which the clamping force is applied by the clamping device.
4.4 Cyclic Redundancy Check (CRC): A method for detecting errors in data.
4.5 Data Zone: An annular area within the user zone on the disk having a constant data clock frequency.
4.6 defect management: A method for handling defective areas on the disk.
4.7 Disk Reference Plane: A plane defined by the perfectly flat annular surface of an ideal spindle onto which the
Clamping Reference Area of the disk is clamped, and which is normal to the axis of rotation.
4.8 entrance surface: The surface of the disk on to which the optical beam first impinges.
4.9 Error Correction Code (ECC): An error-detecting code designed to correct certain kinds of errors in data.
4.10 format: The arrangement or layout of information on the disk.
4.11 hub: The central feature on the disk which interacts with the spindle of the disk drive to provide radial centring and
the clamping force.
4.12 interleaving: The process of allocating the physical sequence of units of data so as to render the data more immune
to burst errors.
4.13 Logical Sector: The minimum addressable user data block.
4.14 Logical Block Address: The address of a block of data.
4.15 mark: A feature of the recording layer, which may take the form of 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.
4.16 mark edge: The transition between a region with a mark and one without a mark or vice versa, along the track.
4.17 mark edge recording: A recording method that uses a mark edge to represent a Channel bit.
4.18 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.
4.19 optical disk cartridge (ODC): A device consisting of a case containing an optical disk.
4.20 polarization: The direction of polarization of an optical beam is the direction of the electric vector of the beam.
4.21 prerecorded mark: A mark written on the recording layer during manufacturing of the disk.
4.22 read power: The read power is the optical power, incident at the entrance surface of the disk, used when reading.
4.23 recording layer: A layer of the disk on, or in, which data is written during manufacture and/or use.
4.24 Reed-Solomon code: An error detection and/or correction code that is particularly suited to the correction of errors
that occur in bursts or are strongly correlated.
4.25 space: The area between marks along the track.
4.26 spindle: The part of the disk drive which contacts the disk and/or hub.
4.27 substrate: A transparent layer of the disk, provided for mechanical support of the recording layer, through which the
optical beam accesses the recording layer.
4.28 track: The path which is followed by the focus of the optical beam during one revolution of the disk.
4.29 track pitch: The distance between the centrelines of adjacent tracks, measured in a radial direction.
4.30 write-inhibit hole: A hole in the case which, when detected by the drive to be open, inhibits write operation.
5 Conventions and notations
5.1 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 1,26 with a positive tolerance of +0,01, and a negative tolerance of -0,02 allows a range of measured
values from 1,235 to 1,275.
− Letters and digits in parentheses represent numbers in 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 digits 0 and 1.
− Numbers in binary notation and bit combinations are shown with the most significant bit to the left.
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ISO/IEC 20162:2001(E)
− Negative values of numbers in binary notation are given in TWO's complement.
− In each field the data is recorded so that the most significant byte (byte 0) is recorded first. 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 their output.
5.2 Names
The names of entities, e.g. specific tracks, fields, etc., are given with a capital initial.
6 List of acronyms
COF Creeping One of Four (code)
CRC Cyclic Redundancy Code
DCb Data Channel bit
ECC Error Correction Code
EDAC Error Detection And Correction
FWHM Full Width Half Maximum
IR Internal Radius
QWT Quadrature Wobble Tracking (mark)
LBA Logical Block Address
lsb least significant bit
LSB Least Significant Byte
MR Middle Radius
msb most significant bit
MSB Most Significant Byte
NSB Next Significant Byte
ODC Optical Disk Cartridge
OR Outside Radius
PBA Physical Block Address
PLL Phase–Locked Loop
RFO Read Focus Optimization
RLL Run Length Limited (code)
R-S Reed-Solomon (code)
SCb Servo Channel bit
SDI Specific Disk Information
SISIC Selective Inter Symbol Interference Cancellation
WORM Write Once Read Multiple
7 General description of the optical disk cartridge
The optical disk cartridge which is 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 by shutters. The windows are automatically
uncovered by the drive when the cartridge is inserted into it.
The optical disk consists of two sides assembled together with their recording layers on the inside.
The optical disk is recordable on both sides. Data is written onto the disk with a focused optical beam as marks in the recording
layer using irreversible effects, such that the marks cannot be erased or transformed back into an unrecorded state. The marks
can be formed by either a phase transformation process, an alloy mode, or any other irreversible process yielding the recording
characteristics specified in section 5. The data are read by detecting the intensity modulation of the reflected beam caused by
the difference of reflectivity and diffraction of the recorded marks and the unrecorded regions. The beam accesses the
recording layer through the transparent substrate of the disk.
The optical disk cartridge is designed to allow for use in a drive with optical access from both sides simultaneously.
8 General requirements
8.1 Environments
8.1.1 Test environment
The test environment is the environment where the air immediately surrounding the optical disk cartridge has the following
properties:
temperature:  23 °C ± 2 °C
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ISO/IEC 20162:2001(E)
relative humidity:  45 % to 55 %
atmospheric pressure: 60 kPa to 106 kPa
air cleanliness:  Class 100 000 (see annex A)
No condensation on or in the optical disk cartridge shall occur. Before testing, the optical disk cartridge shall be conditioned in
this environment for 48 h minimum. It is recommended that, before testing, the entrance surface of the 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 test environment.
8.1.2 Operating environment
This International Standard requires that an optical disk cartridge which meets all requirements of this Standard in the specified
test environment provides data interchange over the specified ranges of environmental parameters in the operating
environment. (See also annex M).
The operating environment is the environment where the air immediately surrounding the optical disk cartridge has the
following properties:
temperature:  5 °C to 55 °C
relative humidity:  3 % to 85 %
3 3
absolute humidity: 1 g/m to 30 g/m
atmospheric pressure: 60 kPa to 106 kPa
temperature gradient: 10 °C/h max.
relative humidity gradient: 10 %/h max.
air cleanliness:  office environment (see M.1)
No condensation on or in the optical disk cartridge shall 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 least 2 h before use.
(See also annex N).
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 has the following properties:
temperature: -10 °C to 55 °C
relative humidity:  3 % to 90 %
3 3
absolute humidity: 1 g/m to 30 g/m
atmospheric pressure: 60 kPa to 106 kPa
temperature gradient: 15 °C/h max.
relative humidity gradient: 10 %/h max.
air cleanliness:  office environment (see M.1)
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.
8.2 Temperature shock
The optical disk cartridge shall withstand a temperature shock of up to 20 °C when inserted into, or removed from, the drive.
8.3 Safety requirements
The cartridge shall satisfy the safety requirements of IEC 60950-1, when used in the intended manner or in any foreseeable use
in an information processing system.
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ISO/IEC 20162:2001(E)
8.4 Flammability
The cartridge and its components shall be made from materials that comply with the flammability class for HB materials, or
better, as specified in IEC 60950-1.
9 Reference Drive
The Reference Drive is a drive several critical components of which have well defined properties and which is used to test the
write and read 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 are specified in those
clauses.
9.1 Optical system
The basic set-up of the optical system of the Reference Drive used for measuring the write and read parameters is shown in
figure 1. Different components and locations of components are permitted, provided that the performance 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.
9.2 Optical beam
The focused optical beam used for writing and reading data shall have the following properties:
+8 nm
a) Wavelength ( λ )   685 nm
-8 nm
b) Wavelength ( λ ) divided by the numerical
aperture of the objective lens (NA)  1,181 µm ± 0,013 µm
c) Filling D/W of the aperture of the objective lens
in both tangential and radial direction  1,22 ± 0,15
d) Variance of the wavefront of the optical
beam near the recording layer after passing
2
through an ideal substrate  0 to λ /180
(thickness: 1,205, index of refraction: 1,51)
e) Polarization   Circular
f) The optical power and pulse width for writing and reading shall be as specified in later clauses.
2
D is the diameter of the lens aperture and W is the beam diameter of the Gaussian beam where the intensity is 1/e of the
maximum intensity.
9.3 Read Channel
A Read Channel, Channel 1, shall be provided to generate a read-out signal S from the pre-written and user-written marks in
the recording layer, using the change in reflectivity and diffraction of the marks.
Signal S which measures the total amount of light reflected by the disk in the exit pupil of the objective lens, is the sum of the
currents J , J , J , J of the four-quadrant photodiodes. This signal is not equalized before detection. It shall be low-pass
1 2 3 4
filtered with a 3-pole Butterworth filter with a cut-off frequency of one half the Channel clock frequency.
9.4 Tracking
Tracking error signals are generated to control the servos for the axial and radial tracking of the focus of the optical beam.
The axial tracking error signal Sa is derived in Channel 2 from the measurement of amplitudes of the four-quadrant photodiode
currents when the light spot scans a dedicated area of the disk, as specified in 19.2.4.1.
The radial tracking error signal Sr is derived from the measurement of amplitudes of the read out signal S in Channel 1 at the
centres of the tracking marks, as specified in 19.2.4.2.
The requirement for the accuracy with which the focus of the optical beam must follow the tracks is specified in 19.2.4.3.
9.5 Rotation of the disk
The spindle shall position the disk as specified in 12.4. It shall rotate the disk at 16,67 Hz ± 0,20 Hz. The direction of rotation
shall be clockwise on side A and counterclockwise on side B, when viewed from the disk entrance surface of the disk of this
side.
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ISO/IEC 20162:2001(E)

aa’’
JJ KK
11
11
bb’’
JJ
CChh11
22
II
JJ KK
33
22
CChh22
JJ
44
aa
bb
II
HH
CC DD EE FF GG
BB
AA
0000--00001166--AA


A Laser diode H Astigmatic lens
B Collimator lens I Four-quadrant photodiode
C Optional shaping prism J , J , J , J Currents of four-quadrant photodiode
1 2 3 4
D Polarizing beam splitter K , K D.C.-coupled amplifiers
1 2
E Optional quarter-wave plate Ch1 Channel 1: Read out channel
F Objective lens Ch2 Channel 2: Axial tracking error channel
G Optical disk aa', bb' Astigmatic focus line directions



Figure 1 — Optical system of the Reference Drive
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ISO/IEC 20162:2001(E)
Section 2 — Mechanical and physical characteristics
10 Dimensional and physical characteristics of the case
10.1 General description of the case
The case (see figure 2) is a rigid protective container of rectangular shape. It allows the spindle of the drive to clamp the disk
by its hub and have a head window on both sides.
Shutters uncover the windows upon insertion into the drive, and automatically cover them upon removal from the drive. The
case has write-inhibit, Side A / B detection features, and gripper slots and notches for an autochanger.
10.2 Relationship of Sides A and B
The features essential for physical interchangeability are represented in figure 2. When Side A of the cartridge faces upwards,
Side B of the disk faces downwards. Sides A and B of the case are identical as far as a group of features are concerned. For this
group, the description is given for one side only (references to Sides A and B can be changed to
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