Elektroonika Alused
CD-ketas on 120mm läbimõõduga polükarbonaadist ketas. Keskel on 15mm läbimõõduga mulk. Kõige sisem
osa peale andmeid ei salvestata. Andmete hoidmiseks mõeldud ala algab 23mm kaugusel ja lõpeb 58.5 mm
kaugusel keskpunktist. The 46-50 mm range is the lead in area and the 116-117 range is the lead out area.
Info kirjutatakse kettale spiraalina seest väljapoole (see vähendab tootmisel tekkivaid vigu ja võimaldab ketta
suurust muuta).
A CD disk contains a long string of pits written helically on the disk. The edges of the pits correspond to bina
"1"s.
Iga pit on umbes 0.5 mikron Each pit is approximately 0.5 microns wide and 0.83 microns to 3.56 microns lon
(Remember that the wavelength of green light is approximately 0.5 micron) Each track is separated from the
next track by 1.6 microns.
The area between the pits is termed "land". So, a highly magnified section of track might look something like:
Pits are formed in the polycarbonate disk by an injection molding process
annaabi.ee 
