ISO IEC 10090:1992 pdf free download.Information technology 90 mm optical disk cartridges, rewritable and read only, for data interchange.
1 Scope
ISO IEC 10090 specifies
– the conditions for conformance testing and the Reference Drive:
– the mechanical and physical characteristics 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;
• 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.
2 Conformance
A 90 mm optical disk cartridge is in conformance with ISO IEC 10090 if it meets all mandatory requirements specified herein.
Annex R specifies the zones of the disk in which the requirements for the signal characteristics given in the body of ISO IEC 10090 Shall be met, and the zones in which a relaxation of these requirements is permitted.
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 ZEROs and ONEs.
– Numbers in binary notation and bit combinations are shown with the most significant bit to the left.
– 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 to their output.
5.2 Names
The names of entities, e.g. specific trks, fields, etc., are given with a capital initial.
The optical disk is recordable on one side. Data can be written onto the disk as marks in the form of magnetic domains in the recording layer and can be erased from it with a focussed optical beam, using the thermo-magnetic effect. The data can be read with a focussed optical beam, using the magneto-optical effect. The beam accesses the recording layer through the transparent substrate of the disk.
Part of the disk or the entire disk may contain read-only data in the form of pits embossed by the manufacturer. This data can be read using the diffraction of the optical beam by the embossed pits.
8 General requirements
81 Environments
8.1.1 Testing 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
Relative humidity : 45 % to 55 %
Atmospheric pressure :60 kPa to 106 kPa
Mmospheric pressure :60 kPa to 106 kPa
Air cleanliness : Class 100 000 (see annex M)
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 optical disk shall 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
ISO IEC 10090 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 has the following properties:
Temperature :5°C to 50 °C
Relative humidity : 3 % to 85 %
Absolute humidity : I g/m3 to 30 g/m3
The cartridge shall satisfy the safety requirements of IEC 950, when used in the intended manner or in any foreseeable use in an information processing system.
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 950.
Reference Drive
The Reference Drive is a drive several critical components of which have well defined properties and which is 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.
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 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.
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 detectcw K1 equal to that of detector K2. 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 25° phase retardation between (he neutral polarization and the polarization perpendicular to it. This position of the retarder is called the neutral position.
The phase retarder can be used for the measurement of the narrow-band signal-to-noise ratio (see 26.2). The beam splitter J shall have a p-s intensity reflectance ratio of at least 100.
The beam splitter E shall have an intensity reflectance from F to H of nominally 0,30 for the neutral polarization direction. The reflectance R1 for the polarization perpendicular to the neutral direction shall be nominally 0,95. The actual value of R1 shall not be smaller than 0,90.
The imbalance of the magneto-optical signal is specified for a beam splitter with nominal reflectances. If the measurement is made on a drive with reflectances R’ and R for beam splitter E. then the measured imbalance shall be multiplied by 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 ± I dB from 100kHz to 11,6MHz.
9.4 Tracking
The Tracking channel 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.
The requirements for the accuracy with which the focus of the optical beam must follow the tracks is specified in 20.2.4.
9.5 Rotation of thedisk
The spindle shall position the disk as specified in 12.4. Ii shall rotate the disk at 30,0 Hz ± 0,3 Hz. The direction of rotation shall be counter-clockwise when viewed from the objective lens.