Basics of CD-R Technology
conventional CD players follow the Sony-Philips Red Book standard,
CD-R conforms to the Orange Book part II standard. Once recorded,
a CD-R disc meets the Red Book standard.
recordable CD is the same size as a standard compact disc, but
is more colourful. On top is a layer of gold (or silver); on the
bottom is a recording layer made of blue cyanine dye. The Orange
Book was written based on the original cyanine dye discs from
Taiyo Yuden. Because of the gold layer behind it, the blue layer
usually appears green.
CD-R discs use a yellow (gold like colour) dye of phthalocyanine.
by the manufacturer, yellow dye lasts a little longer in accelerated
aging tests, and it may work better with high speed CD-R drives.
Still, most CD-R writers are optimized for cyanine dye, which
can handle a wider range of laser power and wavelength. Cyanine
dye is the de facto standard. Most CD-Recorders are optimized
for cyanine dye.
are CD-Rs available on the market that look entirely silver or
gold. They are made with the diamond disc dye from Nissei Sangyo.
The diamond disc dye is crystal clear. Once applied, the reflective
layer of the CD-R simply appears the colour of the CD. Apart from
being clear, the properties of the diamond disc dye are claimed
to be almost identical to pthalocyanine dyes.
blank CD-R is made of four layers:
dye fills a spiral groove which is etched in the bottom clear-plastic
layer. This groove guides the laser. To record data on disc, the
laser melts holes in the dye layer. The plastic layer flows into
the holes to form pits. During playback, the same laser reads
the disc at lower power. At each pit, laser light reflects off
the gold layer. The reflected light enters the laser reader, which
detects the varying reflectance as the pits go by.
contrast with a standard CD, a CD-R disc has two more data areas: