Cd Recorder

A CD / DVD recorder is a compact disc drive that can be used to produce discs readable in other CD / DVD-ROM drives.

A DVD recorder similarly produces DVD discs playable in stand-alone video players or DVD-ROM drives. They are generally used for small-scale archival or data exchange, being slower and more materially expensive than the moulding process used to mass-manufacture pressed discs.

The recorder encodes (or burns) data onto a recordable CD-R, DVD-R or DVD+R disc (called a blank) by selectively heating parts of an organic dye layer in the disc with a laser in its write head. This changes the reflectivity of the dye, thereby creating marks that can be read as with the "pits" and "lands" on pressed discs. The process is permanent and hence the media can be written to only once.

CD and DVD writable Media

For rewriteable CD-RW, DVD-RW and DVD+RW media, the laser is used to melt a crystalline metal alloy in the recording layer of the disc. Depending on the amount of power applied, the substance may be allowed to melt back into crystalline form or left in an amorphous form, enabling marks of varying reflectivity to be created. Most rewriteable media is rated by manufacturers at up to 1000 write/erase cycles.

The competing DVD+R and DVD-R disc formats differ mainly in the way timing hints for the write head are laid out on the disc surface. This is also the case with DVD+RW and DVD-RW.

Internal CD recorders for personal computers, server systems and workstations are designed to fit in a standard drive bay and connect to their hosts via an ATA or SCSI bus. Most external CD recorders have USB, Firewire or SCSI interfaces. Some portable versions for laptop use power themselves off batteries or off their interface bus.

CD, DVD, and Blu-Ray

CD recorders have been replaced by DVD recorders, which include the capability to records CDs as well as DVDs. Newer on the market are Blu-Ray recorders, which can manage CD, DVD, and Blu-Ray discs. Some Blu-Ray recorders have the capability to record up to 128GB of data on quadruple-layer discs.

This article is adapted from: wikiPedia.com.