.: Definitions :.
These definitions include information taken from several CD Glossaries found on the Internet. They are the words that cause the most confusion in the CD Duplicating industry. The IDDA offer these suggested definitions as a guide to further discussion, so that worldwide standards can be agreed and then encouraged. Suggested definitions may be followed by technical information to assist in further discussion. Please email any comments to info@discdupe.org, while IDDA members can post comments directly to the Discussion page.
Business Card CDs and Mini CDs
BusinessCard CDs are CDs the size of a Credit card or Business card; which play in any normal CD player; and weigh only around 10gms. They are big in impact in a small package, and they are today's message on tomorrow's media. Mini CDs, called CD singles, 8cm discs, baby discs etc. are 8 cm discs instead of the standard 12 cm.
There are 2 basic shapes of Business card CDs:
- CDs that are oblong with pins or molded rings that hold the disc in position by running within the inner 8cm tray of the CD player, called eCards, Business Card discs, and
- CDs that are rounded to an 8cm diameter that fit into the inner 8 cm tray, sometimes called hockey rink shaped card discs or rounded card discs.
Comments:
Unfortunately Business Card CDs and Mini CDs and DVDs have lost a bit of their novelty value, and distribution of the product has been threatened by a patent application in the USA, which has been challenged by duplicators and replicators.
CD-R is an acronym Compact Disc-Recordable. This term is used to
describe the technology of recordable CD as well as the equipment;
software; media and technology, which is used to make recordable discs.
The reduction of prices for this hardware and software and their ease
of use have helped the growth of CD-ROM production in-house and by disc
duplicating services.
CD-R [Disc] is a type of media used in recordable CD systems, that
allows you to record digital information using a special recorder (CD
Recorder) together with premastering software with a computer or even a
stand-alone recording system that includes these elements in one unit.
CD-Recordable technology allows production of CD-ROMs on the desktop
('one-offs'). It usually requires a PC, (there are also stand-alone
systems) a CD-R recorder or drive, appropriate software, and
'recordable' media. The 'one-off' disc is very different from the mass
reproduced or 'hot-pressed' CDs. It is sold pre-grooved in 63, 74, 80,
90 and 100-minute capacities of 120mm diameter, as well as in different
shapes, with a sensitive chemical recording layer; of aluminum or gold
reflective material. Once recorded the CD-R disc (one-off) performs in
the same way as the mass-reproduced CDs.
These discs are made of a polycarbonate substrate, a layer of organic
dye, a metalized reflective layer and a protective lacquer coating.
Some discs also have an additional protective coating over the
metalized layer; and some discs have a printable surface silk-screened
on them.
Comments:
CD-R or CDR - CD-R is the correct abbreviation as it is taken from CD-Recordable. The use of “CDR” should be discouraged.
CD-R Technical Description
The
blank disc is made of a bottom layer of polycarbonate with a preformed
track spiral, which the recording laser follows when inscribing
information onto the disc. A translucent layer of recordable material
is laid on top of the polycarbonate; then a reflective layer - gold or
silver colored. Mitsubishi were probably the first to introduce the
silver disc. On top, there is a thin layer of lacquer and sometimes a
printed label.
In manufacturing CD-R media; instead of pits and
lands; a continuous spiral is pressed into the substrate by injection
molding from a stamper as a guide to the recorder's laser. So
all Compact Discs are created by injection molding by replication,
while stamped discs have the digital information molded into the disc
during manufacture, and CD-R are like blank pages ready to have the
digital information added by recorder. Kodak also has a 'hybrid' disc
that contains both stamped data and a recordable track.
The data
layer of CD-R discs is made from either cyanine or phthalocyanine dye,
which is melted during the recording process. Where the dye is melted;
it becomes opaque or refractive, scattering the reading laser beam so
it is not reflected back into the reader's sensors. The difference
between reflected and non-reflected light is interpreted by the player
as a binary signal.
In a "pressed" or mass-replicated CD, the bumps and grooves that
represent the binary data on a disc's substrate are pressed into it
during manufacture. CD-R discs do not have true pits and lands; but the
unmelted; clear areas and melted; opaque places in the dye layer
fulfill the same function as pits and lands on a pressed disc.
The standard recordable disc CD-R is "write-once"- data written to it
cannot be erased, although it is possible to add data in a later
session as Multisession. For erasable/rewritable discs see CD-RW.
The Orange Book
Recordable Compact Disc Standard was developed by Philips and Sony, was
published by Philips in 1990, reportedly in a binder with Orange
Covers. The Orange Book defined two new 12cm CD products: the
Magneto-Optical and the Write-Once. Part 2; Write-Once (CD-WO); defines
tracks that can be written to; but not erased and rewritten - in the
tradition of WORM (write-once read-many) discs. A Write-Once drive
records appropriate 12cm CDs - which involve special recording layers;
pregrooved tracks and; generally a gold reflective layer. The initial
tracks include a Program Calibration Area; are followed by a Lead-In
area (where the Table of Contents will be written); and by the Program
Area - for the user data. The recording session is finished with the
Lead Out. A CD-WO 'Hybrid' disc involves an area where Read-Only files
can be placed; and the rest of the disc is the W-O area. Later; Part 3
was released; which covers Rewritable (Phase Change) products. Part 1;
Magneto-Optical (CD-MO); defines tracks that can be erased and
rewritten - reason why this format is more appropriately known as
Rewritable. M-O drives implement magneto- optical recording technology
on 12cm CDs that are rated to allow millions of rewrites. These drives
are however slower than other optical drives; because they use two
heads - one to erase and the other to write; in a double-pass process.
Some CD-MO products include a small premastered Read-Only area that
usually contains system and other information - but which can also be
read by a regular CD-ROM drive. The remainder space is the Recordable
User Area; and the user can reuse this area at will. Part 3 defines
Rewritable (CD-RW). Some brands designate it as Rewritable PD (for
Phase Change). Developed by Philips and Sony (Oct 96); these
specifications implement Phase Change technology and the Universal Disc
Format (UDF) promoted by OSTA; to produce a CD that can be rewritten in
one pass. Currently CD-RW cannot be read by most CD-ROM and CD-R drives
because CD-RW media has much lower coefficients of reflectivity (15-25
compared to 65- 70%). But; while drives with multiple heads are
considered one solution; the industry is working towards a 'single-head
multiread drive.' Nevertheless; CD-RW phase change drives has almost
replaced the CD-MO drives; and the optical 5.25in products as well.
CD-ROM - The Compact Disc-Read Only Memory is a standard for compact
disc to be used as a digital memory medium for personal computers, a
version of the compact disc for computer data, multimedia and games
applications, instead of digital audio, is the standard 12cm CD
formatted according to ISO 9660. Although the physical characteristics
and track structure of a CD-ROM are the same as that of CD-Audio, a
CD-ROM is used to store computer data, text and graphics. It also
involves additional error detection and correction as specified in the
Yellow Book. The logical volume and file structure of CD-ROM; specified
in the ISO 9660 allows it to be used in the computer arena. Therefore,
a CD with computer data that is not structured according to the ISO
9660 such as a 80 minute discs is not a standard CD-ROM. The music CD
player cannot play CD-ROM discs; but CD-ROM drive can play music discs.
CD-ROMs can contain up to 650MB of data and although the specification
does not include them, most CD-R discs are now 700MB, (though they
often contain a lot less). CD-ROMs have become a favorite medium for
installing programs; the term CD-ROM refers to the technology or the
discs, but not to the hardware that plays the discs, which is a CD-ROM
drive.
Comments:
Is a CD-ROM only for data and multimedia, or can we use CD-ROM to mean a stamped disc as against a duplicated disc? Many organizations have adopted CD-ROM to mean a replicated disc.
CD/DVD Duplication and CD/DVD Replication
Duplication -The reproduction of media. Generally refers to
producing discs in smaller quantities, as opposed to large-scale
replication.
As the cost of media has dropped, as patents expired as production
techniques improved, and as demand increased, blank CD and DVD media
has become cheap enough to compete with replicated media cost for
longer runs.
Replication - The reproduction of media such as optical discs by stamping (contrast with duplication).
Injection Molding - This is a common industrial process to produce plastic products of all shapes.
A manufacturing method where molten material is forced into a mold;
usually under high pressure; and then cooled so the material takes on
the shape of the mirror image of the mold. The injection molding
machines, fitted with appropriates tampers; stamp or press the mold.
A process for replication of CDs wherein molten plastic is
injected into the cavity of a mold under pressure; cooled and removed
as a solid; clear plastic disc. The data information is transferred to
the plastic in this process from the "stamper."
The mastering and replication plants require costly equipment and highly clean environments.
Manufacturing - The process of creating the physical discs
from a master; consisting of creating the glass master; making
stampers; molding the polycarbonate discs; electroplating the discs;
printing the labels; and packaging the discs for the customer.
Quality - There is currently no proven or known difference in the
quality and longevity of Duplicated media as compared to Replicated
media. There are good and bad qualities in both technologies.
Originally some early CD players and early DVD players would not play
duplicated media, but most of these early machines would have been
replaced by 2005.
Comments:
Several
replicators use the word "duplication" to describe the replication
process. The pocket Oxford dictionary defines duplicate as a double,
exactly like the thing existing, or to make exact copy of, while
duplicator is an apparatus for making multiple copies of typed or
handwritten documents. Replicate itself does not appear, but a replica
is a duplicate made by original artist, an exact copy, and facsimile.
It therefore would appear that replicate is a word created by the
industry to mean stamped discs, while a duplicate is descended from the
duplication of documents.
On this premise the use of the word duplicate to include pressed discs is incorrect.
Mastering - In CD-ROM; the final recording of the desired
CD-ROM image to be used as a source for mastering; this may be on tape;
magnetic disc; optical disc (M-O or W-O); etc.
Technically mastering this refers to the process of
creating a glass master from which compact discs is reproduced in
quantity, or the process of replicating optical discs by injecting
liquid plastic into a mold containing a master. Often used inaccurately
to refer to premastering.
The process of encoding input data; created during premastering to
the compact disc standards and recording this information as a series
of pits in a light-sensitive layer on a glass substrate.
Mastering is the process of creating a stamper or set of stampers
to be used in the injection molding stage of manufacturing compact
discs. During this process a digital signal from a computer is used to
guide a laser beam which etches a pattern of "pits and lands" (in the
case of CDs) or a continuous groove (for CD-Rs) onto a highly polished
glass disc coated with photoresist. This "glass master" is then cured
(developed) with ultraviolet light and rinsed off; and a metal (nickel
or silver) mold is electroformed on top of it. This mold is removed and
then electroplated with a nickel alloy to create one or more stampers
to be used in the injection molding machine to press the data into the
polycarbonate substrate of CDs; or the guiding groove into the
substrate of CD-Rs. media or "blanks".
In desktop recordable CD systems; mastering is done together with
premastering by the desktop CD recorder; and the term is generally used
to mean "recording."
Comments:
How do we differentiate the Mastering that is just "making a master" from the Mastering that refers to the Equalization, Compression and other manipulation of audio mixes?
Under the Orange Book standard for recordable CD; hybrid means a
recordable disc on which one or more sessions are already recorded; but
the disc is not closed, leaving space open for future recording.
However; the term "hybrid" often refer to a disc containing both
DOS/Windows and Macintosh software; which on a DOS/Windows platform is
seen as a normal ISO9660 disc; while on a Mac it appears as an HFS
disc.
"Hybrid" is also used to describe a disc that supplements a web site.
Customization in the CD industry usually means each disc is different, either in data content or labeling. To some it means any short run duplication, but we suggest that this is not a recommended definition.