How is the information physically stored?
CD-Rs employ a polycarbonate substrate, a reflective layer, and a protective top layer. Sandwiched between the substrate and reflective layer, however, is a recording layer composed of an organic dye. A pre-grooved spiral track is used to guide the recording laser along the spiral track. This greatly simplifies the design of the recorded hardware and ensures disc compatibility. A laser in the CD recorder creates a series of holes in the disc’s dye layer called ‘pits’. The spaces between the pits are called ‘lands’. The pattern of pits and lands on the disc encodes the information and allows it to be retrieved on an audio or computer CD player.
(2000/04/18) From _The Compact Disc Handbook, 2nd edition_ by Ken Pohlmann, 1992 (ISBN 0-89579-300-8): “Write-once media is manufactured similarly to conventional playback-only discs. As with regular CDs, they employ a polycarbonate substrate, a reflective layer, and a protective top layer. Sandwiched between the substrate and reflective layer, however, is a recording layer composed of an organic dye. …. Unlike regular CDs, a pre-grooved spiral track is used to guide the recording laser along the spiral track; this greatly simplifies recorder hardware design and ensures disc compatibility.” Your basic CD-R is layered like this, from top to bottom: [optional] label [optional] scratch-resistant and/or printable coating UV-cured lacquer Reflective layer (24K gold or a silver-colored alloy) Organic polymer dye Polycarbonate substrate (the clear plastic part) Yes, it’s real gold in “green” and “gold” CDs, but if you hold a CD-R up to a light source you’ll notice that it’s thin enough to s
From _The Compact Disc Handbook, 2nd edition_ by Ken Pohlmann, 1992 (ISBN 0-89579-300-8): “Write-once media is manufactured similarly to conventional playback-only discs. As with regular CDs, they employ a polycarbonate substrate, a reflective layer, and a protective top layer. Sandwiched between the substrate and reflective layer, however, is a recording layer composed of an organic dye. …. Unlike regular CDs, a pre-grooved spiral track is used to guide the recording laser along the spiral track; this greatly simplifies recorder hardware design and ensures disc compatibility.” Your basic CD-R is layered like this, from top to bottom: [optional] label [optional] scratch-resistant and/or printable coating UV-cured lacquer Reflective layer (24K gold or a silver alloy) Organic polymer dye Polycarbonate substrate (the clear plastic part) Yes, it’s real gold in “green” and “gold” CDs, but if you hold a CD-R up to a light source you’ll notice that it’s thin enough to see through (the gold
(2004/02/20) From _The Compact Disc Handbook, 2nd edition_ by Ken Pohlmann, 1992 (ISBN 0-89579-300-8): “Write-once media is manufactured similarly to conventional playback-only discs. As with regular CDs, they employ a polycarbonate substrate, a reflective layer, and a protective top layer. Sandwiched between the substrate and reflective layer, however, is a recording layer composed of an organic dye. …. Unlike regular CDs, a pre-grooved spiral track is used to guide the recording laser along the spiral track; this greatly simplifies recorder hardware design and ensures disc compatibility.” Your basic CD-R is layered like this, from top to bottom: [optional] label [optional] scratch-resistant and/or printable coating UV-cured lacquer Reflective layer (24K gold or a silver alloy) Organic polymer dye Polycarbonate substrate (the clear plastic part) Yes, it’s real gold in “green” and “gold” CDs, but if you hold a CD-R up to a light source you’ll notice that it’s thin enough to see throu
From _The Compact Disc Handbook, 2nd edition_ by Ken Pohlmann, 1992 (ISBN 0-89579-300-8): “Write-once media is manufactured similarly to conventional playback-only discs. As with regular CDs, they employ a polycarbonate substrate, a reflective layer, and a protective top layer. Sandwiched between the substrate and reflective layer, however, is a recording layer composed of an organic dye. …. Unlike regular CDs, a pre-grooved spiral track is used to guide the recording laser along the spiral track; this greatly simplifies recorder hardware design and ensures disc compatibility.” Your basic CD-R is layered like this, from top to bottom: [optional] label [optional] scratch-resistant and/or printable coating UV-cured lacquer Reflective layer (24K gold or a silver-colored alloy) Organic polymer dye Polycarbonate substrate (the clear plastic part) Yes, it’s real gold in “green” and “gold” CDs, but if you hold a CD-R up to a light source you’ll notice that it’s thin enough to see through (t
