Back Laserskyf Afrikaans Compact Disc ALS ሲዲ Amharic Disco compacto AN قرص مضغوط Arabic ܩܘܪܨܐ ܚܠܝܨܐ ARC Discu compautu AST CD Azerbaijani سیدی AZB Compact Disc BAR
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 The readable surface of a compact disc includes a spiral track wound tightly enough to cause light to diffract into a full visible spectrum. | |
| Media type | Optical disc |
|---|---|
| Encoding | Various |
| Capacity | Typically up to 700 MiB (up to 80 minutes audio), 800 MiB (also up to 90 minutes audio), 870 MiB (and up to 99 minutes audio) |
| Read mechanism | 780 nm wavelength, 800 nm wavelength, 870 nm wavelength (infrared and red edge) semiconductor laser (early players used helium–neon lasers),[1] 1,200 Kbit/s (1×) |
| Write mechanism | 780 nm wavelength, 800 nm wavelength, 870 nm wavelength (infrared and red edge) semiconductor laser in recordable formats CD-R and CD-RW, pressed mold (stamper) in read only formats |
| Standard | Rainbow Books |
| Developed by | Philips, Sony |
| Dimensions | Diameter: 120 mm (4.7 in) Thickness: 1.2 mm (0.047 in) |
| Usage | Audio and data storage |
| Extended from | LaserDisc |
| Extended to | |
| Released |
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| Optical discs |
|---|
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The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. The first compact disc was manufactured in August 1982, and was first released in Japan in October 1982 as Compact Disc Digital Audio. The CD was more compact than the LaserDisc (LD) developed in the 1970s. The CD gained rapid popularity in the 1990s. It quickly outsold all other audio formats in the United States by 1991, ending the market dominance of the phonograph record and the cassette tape. By 2000, the CD accounted for 92.3% of the entire market share in regard to music sales.[3] The CD is considered the last dominant audio format of the album era, as the rise of MP3, iTunes, cellular ringtones, and other downloadable music formats in the mid-2000s ended the decade-long dominance of the CD.[4]
The Digital Audio format was later adapted (as CD-ROM) for general-purpose data storage. Several other formats were further derived, including write-once audio and data storage (CD-R), rewritable media (CD-RW), Video CD (VCD), Super Video CD (SVCD), Photo CD, Picture CD, Compact Disc-Interactive (CD-i), Enhanced Music CD, and Super Audio CD (SACD) which may have a CD-DA layer.
Standard CDs have a diameter of 120 millimetres (4.7 in) and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MiB (681,574,400 bytes) of data. Capacity is routinely extended to 80 minutes and 700 MiB (734,003,200 bytes) by arranging data more closely on the same-sized disc. The Mini CD has various diameters ranging from 60 to 80 millimetres (2.4 to 3.1 in); they are sometimes used for CD singles, storing up to 24 minutes of audio, or delivering device drivers.
At the time of the technology's introduction in 1982, a CD could store much more data than a personal computer hard disk drive, which would typically hold 10 MiB. By 2010, hard drives commonly offered as much storage space as a thousand CDs, while their prices had plummeted to commodity levels. In 2004, worldwide sales of audio CDs, CD-ROMs, and CD-Rs reached about 30 billion discs. By 2007, 200 billion CDs had been sold worldwide.[5]
- ^ Träger, Frank (5 May 2012). Springer Handbook of Lasers and Optics. Springer. ISBN 9783642194092.
- ^ "The Compact Disc (CD) is Developed". historyofinformation.com. Retrieved 9 February 2023.
- ^ "U.S. Music Revenue Database". RIAA. Retrieved 17 March 2024.
- ^ Lynskey, Dorian (28 May 2015). "How the compact disc lost its shine". The Guardian. ISSN 0261-3077. Retrieved 17 March 2024.
- ^ Cite error: The named reference
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