are DVDs Made for use in Copiers???
CD/DVD copiers are becoming more available to the
community and as time progresses, having a CD/DVD
copier in your business will be a common place occurrence.
With copiers, a business can now take control of their
own production goals and schedules and produce finished
product that rivals any replicated media.
DVD (Digital Versatile Disc) quickly emerged as the
next step in optical disc technology. DVD-Video has
established itself as the format for delivering high-quality
digital video. Its also evolved into a complete
software storage and distribution solution for enhanced
computer applications. DVD-Video and DVD-ROM, the
first DVDs to hit the consumer market, are pre-recorded
versions that are ideal for full-length feature films
and computer games with highly advanced graphics.
CD-ROM was developed most people never imagined that
they would require anything beyond its 650MB capacity.
The digital revolution has pushed the compact disc
technology to its limit. Developers and content owners
began to realize the need for a medium capable of
processing todays advanced applications.
September of 1995, two major groups (Sony/Philips and
Toshiba/Time Warner), each developing their own format,
agreed to a single standard for a high-density optical
disc, a best practices approach. Sony/Philips
stressed the importance of EFM+ modulation and backward
compatibility with the CD format; DVD desktop machines
play Audio CDs and DVD-ROM drives play most CD formats.
The standard also adopted Toshiba/Time Warners
format of bonding two 0.6mm substrates for a double-sided
disc with 1-4 data layers.
DVD is analogous to a quad-density compact disc because
it has approximately 4 times as many pits as a CD in
the same size area. In the mastering process the laser
creates smaller pits along a tighter spiral.
result is an optical disc that can hold up to 26 times
the data of a CD. DVDs can store from 4.7GB (single-sided,
single layer) to 17.0GB (double sided, dual layer) with
up to 133 minutes of full motion MPEG-2 video on each
layer. With its superior audio and video quality, increased
data capacity, interactive potential and Internet compatibility,
DVD is a medium for the next millennium.
(single side, single layer) DVD-9 (single side, dual
layer) DVD-10 (double side, single layer) DVD-14 (DVD-5
single-layer bonded to a DVD-9 dual-layer) DVD-18 (two
bonded DVD-9 dual-layer substrates)
all discs are the standard 1.2mm thickness)
are similar in nature to CDs. Data is recorded in a
spiral track of pits, and the 4.75-inch diameter-discs
are both read with a laser beam. As with CD manufacturing,
there are five production stages: Mastering, Electroforming,
Replication, Printing and Packaging. But key manufacturing
and internal design differences make DVD a superior
requires extensive post-production work at a Compression
and Authoring House before the assets are delivered
to the replication facility. After a movie has been
transferred from film to videotape, it must be specifically
formatted for DVD. Technicians scan the tape for screen
changes, insert pan-and-scan codes, and enter closed-caption
digital video has numerous elements that are the same,
most of the data that represents the video can be removed
through encoding. The video is compressed into the MPEG-2
format using variable bit rate encoding. After the audio
is compressed into the Dolby AC3 Surround Sound format,
the compressed audio and video are merged to create
a single data stream. Then the data assets are manipulated
on powerful PC workstations with DVD authoring software
in order to create a DLT (digital linear tape) from
the various data and compressed video/audio.
DLT is sent directly to the manufacturing facility.
It is a well-established SCSI tape medium, which has
become the de facto mastering standard. DLT is a robust
format with data capacity of up to 20.0GB - slightly
larger than 8mm tapes, but smaller than VHS tapes.
the DLT is sent to mastering, a Premastered Media Format
Verification (PMFV) is performed. The DDP (disc description
protocol), essentially the table of contents, is checked
to confirm security scrambling status, regional coding,
video title sets and end sector necessaries. It is also
at this point that the copy protection (MacrovisionTM
and/or Content Scramble System) is reviewed and verified.
The customer supplied DLT is now ready for mastering.
requires an entirely different premastering setup. The
customers data can be submitted on various input
medium types, including hard drives, tape backups, multiple
CD-Rs, DVD-Rs, etc. The data is collected, merged and
placed in a single environment per the customers
expectations and directory structure guidelines.
image creation process begins and the content is formatted
according to the customers request, options include
Micro UDF (Universal Disc Format compatible with
ISO 9660), strict ISO (for DOS), Joliet naming, file
placement, transition and layer breakage (only for DVD-9,
certain files on a certain layer), etc. The formatted
content is output to a DLT in DDP 2.0 specification,
and then its ready for mastering. Micro UDF was
initially combined with ISO 9660, todays PC standard.
UDF is now the standard DVD file format and has already
begun to extend and modify what is currently possible
rest of the manufacturing process is the same for DVD-Video
and ROM. Before accessing the content on the DLT, we
begin with the preparation of 240mm (9.5 inch), 6mm
thick glass master. Its chemically cleaned with
nitric acid and solvents and washed using de-ionized
water. After its carefully dried, the clean glass
master is coated with photo resist (a light sensitive
chemical) 130 nanometers thick. The coated glass master
is baked for 20 minutes to remove the carrier solvent.
a binary code, a computer translates the data from the
DLT in a series of on and off pulses (pits
and lands). A Laser Beam Recorder (LBR) exposes the
photo resist with each on pulse from the
laser. The UV laser has a finer focus (than the blue
laser) and burns a smaller writing spot,
which is necessary for the shorter, narrower DVD pits.
The laser records onto the glass in a spiral track from
the center to the outside.
a full 4.7 GB single layer DVD takes over 90 minutes.
This time will decrease with advances in encoding. A
complete DVD could contain up to four mastered layers;
each layer requires its own mastering cut. A DVD
project is more expensive to manufacture than CDs, but
the benefits are tremendous.
recording, the glass master is developed with an alkaline.
The photoresist is washed away at each exposed on
pulse creating a tiny pit of information on the
surface of the glass master. The glass master is then
placed into a vacuum chamber and the surface is covered
with a small amount of nickel. This process, sputtering,
produces a metalized glass that conducts electricity
during the next stage, electroforming. Compact discs
are sometimes coated with silver, but nickel encourages
a cleaner pit definition, which is important for DVD
begins when the metalized glass master is placed into
a bath of Nickel Sulphamate solution. An electric current
is sent through the bath and the positively charged
Nickel ions in the solution give up their charge at
the surface of the glass master, which acts as the cathode.
Nickel balls are placed at the anode which corrode from
Nickel atoms into Nickel ions replenishing the solution.
Subsequently, a layer of Nickel grows on the surface
of the glass. When the glass is removed from the tank,
the Nickel is separated from the glass. This sheet of
Nickel, a reverse image of the data, is called the father
or metal master.
DVDs have smaller pits and require a reading laser with
a finer focus, they require optimum pit replication.
Nickel sputtering produces a high-resolution image of
the photoresist layer. The closer you can emulate the
glass master, the more accurate the final product is
likely to be. The de-silvering procedure (removing the
thin evaporated layer of silver from the nickel father)
can change the pit volume.
the metal master has been separated from the glass,
it is actually possible to use it for replicating discs.
Instead the father is put back into the Nickel Sulphamate
and two successive layers are grown. First the mother
(a positive data image), and then the stamper, which
is grown directly from the mother. The stamper has negative
pit impressions just like the father. After punching
out the center hole and outer edge and polishing its
backside, the stamper is ready to be loaded into an
injection-molding machine. The father and mother are
saved to grow more stampers for future replication runs,
thus saving the manufacturer production time.
stamper is then loaded into an injection-molding machine
for disc replication (literally making a replica of
the image on the stamper). Two machines are required
to make one DVD and each mold produces a 0.6mm disc.
Polycarbonate is heated to a molten state and fed into
the mold, which contains the stamper. Under several
tons of pressure the plastic is compressed against the
stamper and the pits are pressed into the plastic. The
clear plastic disc, with the data intact, is chilled
and removed from the mold.
a DVD disc takes approximately 5 seconds. After
they are pressed, one or both (depending on the format)
0.6mm substrates are sputtered with an aluminum or gold
layer, and then theyre bonded with lacquer and
UV light (it is important to note that the bonding process
will differ extensively for both DVD-14 and DVD-18).
A DVD-5 only has content on one side; the other half
is a dummy substrate. The content side must be aluminized,
but commonly both sides are sputtered (if pit-art is
used for customer artwork, then the second layer must
be aluminized, too). Since a DVD-10 has content on both
sides, both substrates are sputtered with aluminum before
includes a dual-layer feature, which allows both data
layers to be accessed from one side. The bottom substrate
is coated with a semi-reflective gold layer, while the
top half gets aluminum. This allows the laser to read
content from the bottom substrate (layer 0) and when
necessary refocus and read through the gold layer in
order to get data from the second layer (layer 1).
sputtering the substrates, they are ready to be bonded.
A lacquer coating is applied to the top of one side
and it is spun evenly via centrifugal force. The lacquer
acts as a bonding agent as the discs are squeezed together
and placed under a UV light. The UV light cures, hardens
and seals the bond. The bonding adds an additional step
(over CD) to the manufacturing process. Applying the
lacquer coating has been integrated in-line with the
injection-molding machines and is usually used for all
standard magazine-quality offset and silkscreen printing
are available for DVD. The different formats have their
own disparate printing options. In addition to offset
and silkscreen, DVD-5 also offers pit-art (laser graphics)
in lieu of data on the dummy substrate. The customers
artwork is printed on photographic paper as a template,
which is used on mastering lathes to make a pit-art
master stamper. The image is transferred to a stamper
and the molded clear disc contains the pit-art image.
It is the most cost-effective DVD decoration and identification
technique. The graphic image is a long series of off
pulses that defract light to create the customers
a DVD-10 must be flipped to read data from each side,
printing is only available within the inner band, a
4mm area around the center of the disc. DVD-9 silkscreen
printing options are reduced by the adverse effect of
the UV light on disc flatness. The UV light dries the
ink; certain inks harden to a point where it will slightly
bend the disc. Because of the tighter spec, DVDs must
be mechanically and physically more precise than CDs.
This is especially true for DVD-9 with its semi-reflective
layer. Offset printing is a perfectly viable option
for DVD-9 artwork. DVD-14 and DVD-18 will probably be
limited to the same inner band option as DVD-10.
disc flatness or tilt becomes the biggest
production challenge. The disc thickness must be more
uniform with reduced eccentricity from the outside track
to the center hole. An integrated bonding technology
during replication became crucial to producing the flattest
possible discs. The disc itself is a more critical component
due to the tighter pit focus (reduced jitter). Mechanical
parity between the pre-bonded half discs is a necessity.
All of this leads to an expanded step for DVD production
more extensive quality control.
the manufacturing process several different quality
assurance tests are performed. The basic tests include
a Data Verification System (DVS) test and signal verification
tests. DVS ensures that the finished product is identical
to the original image through a bit-for-bit comparison
between the customers input data and the replicated
disc. Signal verification tests confirm that the disc
playback parameters are within required DVD specifications.
tests, including a storage test and a heat cycle test,
ensure that DVDs remain playable and exhibit the same
longevity as CDs. In addition, there is also an in-line
test for flatness and a Differential Phase Detection
(DPD) tracking test. DVD-9 has its own space-layer,
semi-reflective layer testing. It is also important
to check the disc in different manufacturers DVD
players to confirm hardware compatibility.
this extensive testing, the disc is ready to be packaged
and shipped. Packaging has been entirely driven by market
and content providers. The VSDA recommended that DVD-Video
adopt a package similar in size to the VHS box, therefore
retailers wouldnt have to change their shelving
configurations. The most widely accepted options are
the Amaray Box, the AlphaPakTM and the SuperJewel Box.
For DVD-ROM, the standard jewel-box is a cost effective
and durable solution; various other options are also
available. Nevertheless, it is important that the package
is robust and protects the disc from damage during shipping.
Now, the DVD is indeed ready to ship