Pressing of the Most Popular Types of DVD Discs (outer diameter of 120 mm and 80mm / 3 inch).
- DVD 5 and 8 cm / 3 inch DVD (mini) 1,34 GB: only one layer is metallized, using aluminium
- DVD 9 and 8 cm / 3 inch DVD (mini) 2,41 GB: inner layer – metallized, using aluminium outer layer – metallized, using silicon (semi-transparent)
- DVD 10 and 8 cm / 3 inch DVD (mini) 2,68 GB: both layers metallized, using alluminium
Quality of each DVD is checked in the production process using a multistage checking procedure:
- Checking the extent of metallizing
- Checking the “bonding” (whether the adhesive is spread evenly)
- Checking the mouldings (both Layer 0 and Layer 1)
Furthermore, all analogue and digital parameters of the DVD are measured and checked.
All DVD types listed comprise two substrates that have to be bonded together:
|DVD TYPE||CAPACITY||RECORDING LAYER||READING||DISK TYPE|
|DVD 5||4,7 GB||outer layer||from one side||single-sided, single-layer|
|DVD 9||8,5 GB||both layer||from one side||single-sided, dual-layer|
|DVD 10||9,4 GB||both layer||from both sides||single-sided, single-layer|
8 cm (3 inch) mini DVD types
|DVD TYPE||CAPACITY||RECORDING LAYER||READING||DISKU TYPE|
|8cm DVD5||1,34 GB||outer layer||from one side||single-sided, single-layer|
|8cm DVD9||2,41 GB||both layer||from one side||single-sided, dual-layer|
|8cm DVD10||2,68 GB
(1,34 GB + 1,34 GB)
|both layer||from both sides||single-sided, single-layer|
At first glance, DVD disc looks the same as CD. It has the same diameter and thickness and uses the same non-contact method of reading data by laser beam. DVD recording capacity is several times higher than the CD’s 0.65 GB.
There are several DVD formats:
DVD – Video
MPEG-2 video, up to 8 audio language versions and up to 32 subtitle versions plus 9 various camera angles available. DVD -Video disc also features a navigation system for easy access to the particular information stored on the disc and to other functions.
DVD – ROM
uses the popular UDF/ISO (Universal Data Format /Industrial Standard Organisation) format readable under all PC operating systems that support UDF.
DVD – Audio
In addition to the large capacity provided by the DVD format, DVD – Audio’s benefits include the possibility of storing a digital sound recording with a higher sampling frequency (48 kHz, 96 kHz or 192 kHz) and a greater data resolution (up to 24 bits for DVD – Audio instead of Audio CD’s 16 bits).
is a combination of two or more formats.
The main benefits of the DVD technology are
- Superior image available in broadcast quality plus surround sound
- Large capacity of the disc, allowing to store more than two hours of video on a DVD 5 disc
- Interactivity, providing perfect (fast and easy) navigation within DVD title’s structure, i.e. accurate access to any specific sequence of this huge volume of information stored on the disc or to a specified section of the video programme within one-second accuracy, as well as the availability of the repeat mode and the forward/reverse and fast/slow step motion
- Disc’s capability of holding up to 8 language versions, which can be arbitrarily switched between while viewing the title
- Making use of up to more 32 text layers for subtitles in various languages, which the user can also change arbitrarily
- A choice of up to 9 viewing angles accessible while watching the title
- Up to 8-level security preventing access to selected information
- Support for widescreen picture and the 16:9 aspect ratio (e.g. one side of a double-sided DVD 10 disc may contain the 4:3 presentation while the 16:9 presentation may be stored on the other side)
- Discs indestructible by being played, resistant to magnetic field and easy to store
- DVD format’s versatility plus features encouraging its use for a wide range of human activities