Dvd

23

45

Digital Versatile DiscPhilips, Sony, Toshiba and Panasonic

(1995)

Offers high storage capacity

Disk Diameter - 120mm

Uses MPEG-2 file and compression standards

1

23

45

Disc Thickness 1.2mm (0.6mm x 2)

Recording Technology Phase Change

Recording LASER Wavelength 650nm

Single Sided: 4.7 gigabyte storage capacity

Double sided: up to 17 gigabytes

1

Formats ( Physical Formats)

Formats

• DVD+R

recordable DVD format similar to CD-R

can record data only once and then the data becomes permanent on the disc.

Formats

• DVD+RW

re-recordable format similar to CD-RW

The data can be erased and recorded over numerous times without

damaging the medium.

Formats

Philips, Sony, Hewlett-Packard, Dell, Ricoh, Yamaha

and others.

Formats

• DVD-R

recordable format similar to CD-R and DVD+R

Can record data only once

2 Standards for DVD-R

• DVD-RA for authoring 635 nm laser

available in limited form

• DVD-RA for general use 650 nm laser

more widely used

Formats

• DVD-RW

re-recordable format similar to CD-RW and DVD+RW

Formats

• DVD-RAM

Typically housed in a cartridge

Can be recorded and erased repeatedly

Compatible only with devices manufactured by the companiesThat support the DVD-RAM format

Formats

Panasonic, Toshiba, Apple Computer,

Hitachi, NEC, Pioneer, Samsung and Sharp

Formats

• DVD-ROM

1st DVD standard to hit the market

Read only format

Video or game content is burned once

For DVD-ROM equipped device only

Formats

• DVD+R DL and DVD-R DL

• Use dual layer technology(double layer)

• Employs second physical layer within the disc itself

• The dual layered discs (DVD+R9 and DVD-R9) can hold 8.5GB and double sided dual layer (called dvd-18) can hold 15.9GB.

LAYER

Storing and reading the DATA

Encoding Digital data are encoded by means of pits on the

recording layer of the disc.

MPEG-2compresses it into a very

small amount of space

Lasers are extremely precise, which allows them to read divots as tiny as the

ones on the DVD