Compact disc
device · 1982 · Digital age
Digital sound recording on an optical disc.
Inventors: Sony Group, Koninklijke Philips NV, Kees Schouhamer Immink, James Russell.
What it is made of
- Clear polycarbonate disc — has part. A transparent disc with a track of pits.
- Reflective metal layer — has part. An aluminium coating reflects the laser.
- Protective lacquer layer — has part. A coating over the reflective layer.
Principles and materials it uses
- Binary number system — uses. Sound is recorded as numbers.
- Plastic — is made of. The disc is polycarbonate.
- Aluminium — is made of. The reflective layer is aluminium.
History: what it evolved from and what it influenced
- Vinyl record — evolved from. A digital replacement for the record.
What it is a kind of
- Optical disc (CD/DVD) — is a kind of. An optical disc.