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![Panasonic SL-S250C with Philips LC0305 20110106](https://upload.wikimedia.org/wikipedia/commons/9/9a/Panasonic_SL-S250C_with_Philips_LC0305_20110106.jpg)
A CD player is an electronic device that plays audio
compact disc
The compact disc (CD) is a Digital media, digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then rele ...
s, which are a
digital optical disc
In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...
data storage
Data storage is the recording (storing) of information (data) in a storage medium. Handwriting, phonographic recording, magnetic tape, and optical discs are all examples of storage media. Biological molecules such as RNA and DNA are conside ...
format. CD players were first sold to consumers in 1982. CDs typically contain recordings of audio material such as music or
audiobook
An audiobook (or a talking book) is a recording of a book or other work being read out loud. A reading of the complete text is described as "unabridged", while readings of shorter versions are abridgements.
Spoken audio has been available in sc ...
s. CD players may be part of home
stereo
Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration ...
systems,
car audio
Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants. Until the 1950s it consisted of a simple AM radio. Additions since then have included FM radio (1952), 8 ...
systems,
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...
s, or
portable CD player
A portable CD player is a portable audio player used to play compact discs. The first audio player released was the Discman D-50 by Sony.Lungu, R"History of the Portable Audio Player." 2008-11-27.
Features
The basic features of a portable CD ...
s such as CD
boombox
A boombox is a transistorized portable music player featuring one or two cassette tape recorder/players and AM/FM radio, generally with a carrying handle. Beginning in the mid 1980s, a CD player was often included. Sound is delivered through ...
es. Most CD players produce an output signal via a
headphone
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an au ...
jack or
RCA jack
The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug an ...
s. To use a CD player in a home stereo system, the user connects an RCA cable from the RCA jacks to a
hi-fi (or other
amplifier
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It may increase the power significantly, or its main effect may be to boost the v ...
) and
loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or " ...
s for listening to music. To listen to music using a CD player with a headphone output jack, the user plugs headphones or earphones into the headphone jack.
Modern units can play audio formats other than the original CD
PCM audio coding, such as
MP3
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
,
AAC and
WMA.
DJs playing
dance music
Dance music is music composed specifically to facilitate or accompany dancing. It can be either a whole musical piece or part of a larger musical arrangement. In terms of performance, the major categories are live dance music and recorded danc ...
at clubs often use specialized players with an adjustable playback speed to alter the
pitch and tempo of the music.
Audio engineer
An audio engineer (also known as a sound engineer or recording engineer) helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, ...
s using CD players to play music for an event through a
sound reinforcement system
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds ...
use professional audio-grade CD players. CD playback functionality is also available on
CD-ROM/DVD-ROM drive equipped computers as well as on
DVD player
A DVD player is a device that plays DVDs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. Some DVD players will also play audio CDs. DVD players are connected to a television to wa ...
s and most optical disc-based
home video game console
A home video game console is a video game console that is designed to be connected to a display device, such as a television, and an external power source as to play video games. Home consoles are generally less powerful and customizable than ...
s.
History
![JVC CD player](https://upload.wikimedia.org/wikipedia/commons/8/84/JVC_CD_player.JPG)
American inventor
James T. Russell is known for inventing the first system to record digital information on an optical
transparent
Transparency, transparence or transparent most often refer to:
* Transparency (optics), the physical property of allowing the transmission of light through a material
They may also refer to:
Literal uses
* Transparency (photography), a still, ...
foil
Foil may refer to:
Materials
* Foil (metal), a quite thin sheet of metal, usually manufactured with a rolling mill machine
* Metal leaf, a very thin sheet of decorative metal
* Aluminium foil, a type of wrapping for food
* Tin foil, metal foil ...
that is lit from behind by a high-power halogen lamp. Russell's patent application was first filed in 1966, and he was granted a patent in 1970. Following litigation, Sony and Philips licensed Russell's patents (then held by a Canadian company, Optical Recording Corp.) in the 1980s.
The Compact Disc is an evolution of
LaserDisc
The LaserDisc (LD) is a home video format and the first commercial optical disc storage medium, initially licensed, sold and marketed as DiscoVision, MCA DiscoVision (also known simply as "DiscoVision") in the United States in 1978. Its diam ...
technology, where a focused
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
beam
is used that enables the high information density required for high-quality digital audio signals.
Prototypes were developed by
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
and
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
independently in the late 1970s. In 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. After a year of experimentation and discussion, the ''
Red Book''
CD-DA
Compact Disc Digital Audio (CDDA or CD-DA), also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the ''Red Book'', one of a series of Rainbow Books (named ...
standard was published in 1980. After their commercial release in 1982, compact discs and their players were extremely popular. Despite costing up to $1,000, over 400,000 CD players were sold in the United States between 1983 and 1984. The success of the compact disc has been credited to the cooperation between
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
and
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
, who came together to agree upon and develop compatible hardware. The unified design of the compact disc allowed consumers to purchase any disc or player from any company, and allowed the CD to dominate the at-home music market unchallenged.
The
Sony CDP-101
The Sony CDP-101 is the world's first commercially released compact disc player. The system was launched in Japan on October 1, 1982 at a list price of 168,000 yen (approx US$730).
The Japan-only launch was partially because Philips, Sony's pa ...
, released in 1982, was the world's first commercially released compact disc player.
Unlike early
LaserDisc
The LaserDisc (LD) is a home video format and the first commercial optical disc storage medium, initially licensed, sold and marketed as DiscoVision, MCA DiscoVision (also known simply as "DiscoVision") in the United States in 1978. Its diam ...
players, first CD players already used
laser diode
file:Laser diode chip.jpg, The laser diode chip removed and placed on the eye of a needle for scale
A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a di ...
s instead of larger
helium-neon lasers.
Digital audio laser-disc prototypes
In 1974, Lou Ottens, director of the audio division of
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
, started a small group with the aim to develop an analog
optical audio disc with a diameter of and a sound quality superior to that of the vinyl record. However, due to the unsatisfactory performance of the analog format, two Philips research engineers recommended a digital format in March 1974.
In 1977, Philips then established a laboratory with the mission of creating a digital audio disc. The diameter of Philips's prototype compact disc was set at , the diagonal of an audio cassette.
Heitaro Nakajima
was a Japanese digital audio pioneer, who led Sony's Compact Disc project in the 1970s.
Born in Kurume, Fukuoka Prefecture, Nakajima graduated from the Tokyo Institute of Technology with a bachelor's degree in electrical engineering in 1944, an ...
, who developed an early digital audio recorder within Japan's national public broadcasting organization
NHK
, also known as NHK, is a Japanese public broadcaster. NHK, which has always been known by this romanized initialism in Japanese, is a statutory corporation funded by viewers' payments of a television license fee.
NHK operates two terrestr ...
in 1970, became general manager of
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
's audio department in 1971. His team developed a digital
PCM adaptor
A PCM adaptor is a device that encodes digital audio as video for recording on a videocassette recorder. The adapter also has the ability to decode a video signal back to digital audio for playback. This digital audio system was used for mast ...
audio tape recorder using a
Betamax
Betamax (also known as Beta, as in its logo) is a consumer-level analog recording and cassette format of magnetic tape for video, commonly known as a video cassette recorder. It was developed by Sony and was released in Japan on May 10, 1975, ...
video recorder in 1973. After this, in 1974 the leap to storing digital audio on an optical disc was easily made.
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
first publicly demonstrated an optical digital audio disc in September 1976. A year later, in September 1977, Sony showed the press a disc that could play 60 minutes of digital audio (44,100 Hz sampling rate and 16-bit resolution) using
MFM modulation.
In September 1978, the company demonstrated an optical digital audio disc with a 150-minute playing time, 44,056 Hz sampling rate, 16-bit linear resolution, and
cross-interleaved error correction
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communica ...
code—specifications similar to those later settled upon for the standard Compact Disc format in 1980. Technical details of Sony's digital audio disc were presented during the 62nd
AES Convention, held on 13–16 March 1979, in
Brussels
Brussels (french: Bruxelles or ; nl, Brussel ), officially the Brussels-Capital Region (All text and all but one graphic show the English name as Brussels-Capital Region.) (french: link=no, Région de Bruxelles-Capitale; nl, link=no, Bruss ...
.
Sony's AES technical paper was published on 1 March 1979. A week later, on 8 March, Philips publicly demonstrated a prototype of an optical digital audio disc at a press conference called "Philips Introduce Compact Disc"
in
Eindhoven
Eindhoven () is a city and municipality in the Netherlands, located in the southern province of North Brabant of which it is its largest. With a population of 238,326 on 1 January 2022,[Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...]
.
Collaboration and standardization
![Time destroyed CD](https://upload.wikimedia.org/wikipedia/commons/3/3c/Time_destroyed_CD.JPG)
Sony executive
Norio Ohga
, otherwise spelled ''Norio Oga'' (January 29, 1930 – April 23, 2011), was the former president and chairman of Sony Corporation, credited with spurring the development of the compact disc as a commercially viable audio format.
Biography
Early ...
, later CEO and chairman of Sony, and
Heitaro Nakajima
was a Japanese digital audio pioneer, who led Sony's Compact Disc project in the 1970s.
Born in Kurume, Fukuoka Prefecture, Nakajima graduated from the Tokyo Institute of Technology with a bachelor's degree in electrical engineering in 1944, an ...
were convinced of the format's commercial potential and pushed further development despite widespread skepticism.
As a result, in 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. Led by engineers
Kees Schouhamer Immink and
Toshitada Doi
is a Japanese electrical engineer, who played a significant role in the digital audio revolution. He received a degree in electrical engineering from the Tokyo Institute of Technology in 1964, and a PhD from Tohoku University in 1972.
He joined ...
, the research pushed forward
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
and
optical disc
In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...
technology.
After a year of experimentation and discussion, the task force produced the ''
Red Book''
CD-DA
Compact Disc Digital Audio (CDDA or CD-DA), also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the ''Red Book'', one of a series of Rainbow Books (named ...
standard. First published in 1980, the standard was formally adopted by the
IEC
The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...
as an international standard in 1987, with various amendments becoming part of the standard in 1996.
Philips coined the term ''compact disc'' in line with another audio product, the
Compact Cassette
The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens ...
,
and contributed the general
manufacturing
Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to a r ...
process
A process is a series or set of activities that interact to produce a result; it may occur once-only or be recurrent or periodic.
Things called a process include:
Business and management
*Business process, activities that produce a specific se ...
, based on video LaserDisc technology. Philips also contributed
eight-to-fourteen modulation
Eight-to-fourteen modulation (EFM) is a data encoding technique – formally, a ''line code'' – used by compact discs (CD), laserdiscs (LD) and pre- Hi-MD MiniDiscs. EFMPlus is a related code, used in DVDs and Super Audio CDs (SACDs).
EFM and ...
(EFM), which offers a certain resilience to defects such as scratches and fingerprints, while Sony contributed the
error-correction
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communica ...
method,
CIRC
Circ or CIRC may refer to:
* Čirč, a village and municipality in northern Slovakia
* Circ (company), a German scooter-sharing company acquired by Bird
* Circ (duo), an American music duo
* China Insurance Regulatory Commission
* Climate Impact ...
. The ''Compact Disc Story'',
told by a former member of the task force, gives background information on the many technical decisions made, including the choice of the sampling frequency, playing time, and disc diameter. The task force consisted of around four to eight persons,
though according to Philips, the Compact Disc was "invented collectively by a large group of people working as a team."
First ''Red Book'' CDs and players
“Red Book” was the first standard in the
Rainbow Books
The Rainbow Books are a collection of CD format specifications.
''Red Book'' (1980)
*CD-DA (''Digital Audio'') – standardized as IEC 60908
**CD-Text—a 1996 extension to CD-DA
** CD-MIDI—part of the original red-book standard
**CD+G (' ...
series of standards.
Philips established the Polydor Pressing Operations plant in
Langenhagen near
Hannover
Hanover (; german: Hannover ; nds, Hannober) is the capital and largest city of the German States of Germany, state of Lower Saxony. Its 535,932 (2021) inhabitants make it the List of cities in Germany by population, 13th-largest city in Germa ...
,
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
, and quickly passed a series of milestones.
* The first ''test pressing'' was of a recording of
Richard Strauss
Richard Georg Strauss (; 11 June 1864 – 8 September 1949) was a German composer, conductor, pianist, and violinist. Considered a leading composer of the late Romantic and early modern eras, he has been described as a successor of Richard Wag ...
's ''
Eine Alpensinfonie
''An Alpine Symphony'' (''Eine Alpensinfonie''), Op. 64, is a tone poem for large orchestra written by German composer Richard Strauss in 1915. It is one of Strauss's largest non-operatic works; the score calls for about 125 players and a t ...
'' (''An Alpine Symphony'') played by the
Berlin Philharmonic
The Berlin Philharmonic (german: Berliner Philharmoniker, links=no, italic=no) is a German orchestra based in Berlin. It is one of the most popular, acclaimed and well-respected orchestras in the world.
History
The Berlin Philharmonic was fo ...
and conducted by
Herbert von Karajan
Herbert von Karajan (; born Heribert Ritter von Karajan; 5 April 1908 – 16 July 1989) was an Austrian conductor. He was principal conductor of the Berlin Philharmonic for 34 years. During the Nazi era, he debuted at the Salzburg Festival, wit ...
, who had been enlisted as an ambassador for the format in 1979.
* The first ''public demonstration'' was on the
BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
...
television program ''
Tomorrow's World
''Tomorrow's World'' is a former British television series about contemporary developments in science and technology. First transmitted on 7 July 1965 on BBC1, it ran for 38 years until it was cancelled at the beginning of 2003. The ''Tomorro ...
'' in 1981, when the
Bee Gees
The Bee Gees
were a musical group formed in 1958 by brothers Barry, Robin, and Maurice Gibb. The trio were especially successful in popular music in the late 1960s and early 1970s, and later as prominent performers in the disco music era in ...
' album ''
Living Eyes'' (1981) was played.
* The first ''commercial'' compact disc was produced on 17 August 1982. It was a recording from 1979 of
Claudio Arrau
Claudio Arrau León (; February 6, 1903June 9, 1991) was a Chilean pianist known for his interpretations of a vast repertoire spanning the baroque to 20th-century composers, especially Bach, Beethoven, Schubert, Chopin, Schumann, Liszt and Bra ...
performing Chopin waltzes (Philips 400 025-2). Arrau was invited to the Langenhagen plant to press the start button.
* The first ''popular music'' CD produced at the new factory was ''
The Visitors'' (1981) by
ABBA
ABBA ( , , formerly named Björn & Benny, Agnetha & Anni-Frid or Björn & Benny, Agnetha & Frida) are a Swedish supergroup formed in Stockholm in 1972 by Agnetha Fältskog, Björn Ulvaeus, Benny Andersson, and Anni-Frid Lyngstad. The group's ...
.
* The first 50 titles were ''released'' in Japan on 1 October 1982, with the first-cataloged CD in this wave being a reissue of
Billy Joel
William Martin Joel (born May 9, 1949) is an American singer, pianist and songwriter. Commonly nicknamed the "Piano Man (song), Piano Man" after his album and signature song of the same name, he has led a commercially successful career as a solo ...
's ''
52nd Street
52nd Street is a -long one-way street traveling west to east across Midtown Manhattan, New York City. A short section of it was known as the city's center of jazz performance from the 1930s to the 1950s.
Jazz center
Following the repeal of ...
''.
The Japanese launch was followed in March 1983 by the introduction of CD players and discs to Europe and North America (where CBS Records released sixteen titles).
This event is often seen as the "Big Bang" of the digital audio revolution. The new audio disc was enthusiastically received, especially in the early-adopting
classical music
Classical music generally refers to the art music of the Western world, considered to be distinct from Western folk music or popular music traditions. It is sometimes distinguished as Western classical music, as the term "classical music" also ...
and
audiophile
An audiophile is a person who is enthusiastic about high-fidelity sound reproduction. An audiophile seeks to reproduce the sound of a piece of recorded music or a live musical performance, typically inside closed headphones, In-ear monitors, open ...
communities, and its handling quality received particular praise. As the price of players gradually came down, and with the introduction of the portable
Walkman
Walkman, stylised as , is a brand of portable audio players manufactured and marketed by Japanese technology company Sony since 1979. The original Walkman was a portable cassette player and its popularity made "walkman" an unofficial term for ...
, the CD began to gain popularity in the larger popular and rock music markets. The first artist to sell a million copies on CD was
Dire Straits
Dire Straits were a British rock band formed in London in 1977 by Mark Knopfler (lead vocals and lead guitar), David Knopfler (rhythm guitar and backing vocals), John Illsley (bass guitar and backing vocals) and Pick Withers (drums and percuss ...
, with their 1985 album ''
Brothers in Arms''.
['']Maxim
Maxim or Maksim may refer to:
Entertainment
* ''Maxim'' (magazine), an international men's magazine
** ''Maxim'' (Australia), the Australian edition
** ''Maxim'' (India), the Indian edition
*Maxim Radio, ''Maxim'' magazine's radio channel on Sir ...
'', 2004 The first major artist to have his entire catalogue converted to CD was
David Bowie
David Robert Jones (8 January 194710 January 2016), known professionally as David Bowie ( ), was an English singer-songwriter and actor. A leading figure in the music industry, he is regarded as one of the most influential musicians of the ...
, whose 15 studio albums were made available by
RCA Records
RCA Records is an American record label currently owned by Sony Music Entertainment, a subsidiary of Sony Corporation of America. It is one of Sony Music's four flagship labels, alongside RCA's former long-time rival Columbia Records; also A ...
in February 1985, along with four greatest hits albums.
[The New Schwann Record & Tape Guide Volume 37 No. 2 February 1985] In 1988, 400 million CDs were manufactured by 50 pressing plants around the world.
[MAC Audio News. No. 178, November 1989. pp 19-21 Glenn Baddeley. ''November 1989 News Update''. Melbourne Audio Club Inc.]
Further development and decline
The CD was planned to be the successor of the
gramophone record
A phonograph record (also known as a gramophone record, especially in British English), or simply a record, is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts nea ...
for playing music, rather than primarily as a data storage medium, but from its origins as a format for music, its use has grown to encompass other applications. In 1983, following the CD's introduction,
Immink and
Braat presented the first experiments with erasable compact discs during the 73rd
AES Convention. In June 1985, the computer-readable
CD-ROM
A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both comput ...
(read-only memory) was introduced and, in 1990, the
CD-R
CD-R (Compact disc-recordable) is a digital optical disc storage format. A CD-R disc is a compact disc that can be written once and read arbitrarily many times.
CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the i ...
ecordable, also developed by both Sony and Philips.
[The world's first CD-R was made by the Japanese firm ]Taiyo Yuden
is a Japanese materials and electronics company, situated in Kyobashi, Chuo, Tokyo, that helped pioneer recordable CD technology (CD-R) along with Sony and Philips in 1988. Founded 70 years ago, Taiyo Yuden currently operates factories in Japa ...
Co., Ltd. in 1988 as part of the joint Philips-Sony development effort. Recordable CDs were a new alternative to tape for recording music and copying music albums without the defects introduced in the compression used in other digital recording methods. Other newer video formats such as
DVD
The DVD (common abbreviation for Digital Video Disc or Digital Versatile Disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kind ...
and
Blu-ray
The Blu-ray Disc (BD), often known simply as Blu-ray, is a digital optical disc data storage format. It was invented and developed in 2005 and released on June 20, 2006 worldwide. It is designed to supersede the DVD format, and capable of sto ...
use the same physical geometry as CD, and most DVD and Blu-ray players are
backward compatible
Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially in ...
with audio CD.
By the early 2000s, the CD player had largely replaced the
audio cassette
The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Otten ...
player as standard equipment in new automobiles, with 2010 being the final model year for any car in the US to have a factory-equipped cassette player.
Currently, with the increasing popularity of portable digital audio players, such as mobile phones, and solid state music storage, CD players are being phased out of automobiles in favor of minijack auxiliary inputs and connections to USB devices.
Some CD players incorporate disc changers. Commonly these can hold 3 or 5 discs at once and change from one disc to the next without user intervention. Disc changers capable of holding up to 400 discs at once were available. Also, the user can manually choose the disc to be played, making it similar to a
jukebox
A jukebox is a partially automated music-playing device, usually a coin-operated machine, that will play a patron's selection from self-contained media. The classic jukebox has buttons, with letters and numbers on them, which are used to selec ...
. They were often built into car audio and home stereo systems, although a 7 disc CD changer was once made by NEC for PCs. Some could also play DVD and Blu-ray discs.
Meanwhile, with the advent and popularity of
Internet-based distribution of files in
lossily-compressed audio format
An audio format is a medium for sound recording and reproduction. The term is applied to both the physical recording media and the recording formats of the audio content—in computer science it is often limited to the audio file format, but its w ...
s such as
MP3
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
, sales of CDs began to decline in the 2000s. For example, between 2000 and 2008, despite overall growth in music sales and one anomalous year of increase, major-label CD sales declined overall by 20%
– although independent and DIY music sales may be tracking better (according to figures released 30 March 2009), and CDs still continue to sell greatly.
As of 2012, CDs and DVDs made up only 34 percent of music sales in the United States. In Japan, however, over 80 percent of music was bought on CDs and other physical formats as of 2015. As of 2020, compact cassettes, vinyl records, and CDs are still being released by some musicians, primarily as merchandise, to allow fans to provide financial support while receiving something tangible in return.
Inner workings
The process of playing an audio CD, touted as a digital audio storage medium, starts with the plastic polycarbonate compact disc, a medium that contains the digitally encoded data. The disc is placed in a tray which either opens up (as with portable CD players) or slides out (the norm with in-home CD players, computer disc drives and game consoles). In some systems, the user slides the disc into a slot (e.g., car stereo CD players). Once the disc is loaded into the tray, the data is read out by a mechanism that scans the spiral data track using a
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
beam. An electric motor spins the disc. The tracking control is done by analogue servoamplifiers and then the high frequency analogue signal read from the disc is digitized, processed and decoded into analogue audio and digital control data which is used by the player to position the playback mechanism on the correct track, do the skip and seek functions and display track, time, index and, on newer players in the 2010s, display title and artist information on a display placed in the front panel.
Analogue signal recovery from the disc
![BenQ DW1640 - laser unit - lens with coils-0612](https://upload.wikimedia.org/wikipedia/commons/2/2d/BenQ_DW1640_-_laser_unit_-_lens_with_coils-0612.jpg)
To read the data from the disc, a laser beam shines on the surface of the disc. Surface differences between discs being played, and tiny position differences once loaded, are handled by using a movable lens with a very close focal length to focus the light on the disc. A low mass lens coupled to an electromagnetic coil is in charge of keeping focused the beam on the 600
nm wide data track.
When the player tries to read from a stop, it first does a focus seek program that moves the lens up and down from the surface of the disc until a reflection is detected; when there is a reflection, the servo electronics lock in place keeping the lens in perfect focus while the disc rotates and changes its relative height from the optical block.
Different brands and models of optical assemblies use different methods of focus detection. On most players, the focus position detection is made using the difference in the current output of a block of four photodiodes. The photodiode block and the optics are arranged in such a way that a perfect focus projects a circular pattern on the block while a far or near focus projects an ellipse differing in the position of the long edge in north–south or west-southwest. That difference is the information that the servoamplifier uses to keep the lens at the proper reading distance during the playback operation, even if the disc is warped.
Another servo mechanism in the player is in charge of keeping the focused beam centered on the data track.
Two optical pick-up designs exists, the original CDM series from Philips use a magnetic actuator mounted on a swing-arm to do coarse and fine tracking. Using only one laser beam and the 4 photodiode block, the servo knows if the track is centred by measuring side-by-side movement of the light of beam hitting on the block and corrects to keep the light on the centre.
The other design by Sony uses a diffraction grating to part the laser light into one main beam and two sub-beams. When focused, the two peripheral beams cover the border of the adjacent tracks a few
micrometer Micrometer can mean:
* Micrometer (device), used for accurate measurements by means of a calibrated screw
* American spelling of micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; ...
s apart from the main beam and reflect back on two photodiodes separated from the main block of four. The servo detects the RF signal being received on the peripheral receivers and the difference in output between these two diodes conform the tracking error signal that the system uses to keep the optics in the proper track. The tracking signal is fed to two systems, one integrated in the focus lens assembly can do fine tracking correction and the other system can move the entire optical assembly side by side to do coarse track jumps.
The sum of the output from the four photodiodes makes the RF or high frequency signal which is an electronic mirror of the pits and lands recorded on the disc. The RF signal, when observed on an oscilloscope, has a characteristic "fish-eye" pattern and its usefulness in servicing the machine is paramount for detecting and diagnosing problems, and calibrating CD players for operation.
Digital signal processing
The first stage in the processing chain for the analog RF signal (from the photoreceptor device) is digitizing it. Using various circuits like a simple comparator or a data slicer, the analog signal becomes a chain of two binary digital values, 1 and 0. This signal carries all the information in a CD and is modulated using a system called
EFM (Eight-to-fourteen modulation). The second stage is demodulating the EFM signal into a data frame that contains the audio samples, error correction parity bits, according with the
CIRC
Circ or CIRC may refer to:
* Čirč, a village and municipality in northern Slovakia
* Circ (company), a German scooter-sharing company acquired by Bird
* Circ (duo), an American music duo
* China Insurance Regulatory Commission
* Climate Impact ...
error correction code, and control data for the player display and micro-computer.
The EFM demodulator also decodes part of the CD signal and routes it to the proper circuits, separating audio, parity and control (subcode) data.
After demodulating, a CIRC error corrector takes each audio data frame, stores it in a
SRAM memory and verifies that it has been read correctly, if it is not, it takes the parity and correction bits and fixes the data, then it moves it out to a
DAC to be converted to an analog audio signal. If the data missing is enough to make recovery impossible, the correction is made by interpolating the data from subsequent frames so the missing part is not noticed. Each player has a different interpolation ability. If too many data frames are missing or unrecoverable, the audio signal may be impossible to fix by interpolation, so an audio mute flag is raised to mute the DAC to avoid invalid data to be played back.
The Redbook standard dictates that, if there is invalid, erroneous or missing audio data, it cannot be output to the speakers as digital noise, it has to be muted.
Player control
The Audio CD format requires every player to have enough processing power to decode the CD data; this is normally made by application-specific integrated circuits (ASICs). ASICs do not work by themselves, however; they require a main microcomputer or
microcontroller
A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable i ...
to orchestrate the entire machine. The
firmware
In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide h ...
of basic CD players typically is a
real-time operating system
A real-time operating system (RTOS) is an operating system (OS) for real-time applications that processes data and events that have critically defined time constraints. An RTOS is distinct from a time-sharing operating system, such as Unix, which m ...
.
Some early optical computer drives are equipped with an audio connector and buttons for standalone CD playback functionality.
Tray design types
Tray loading
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
released its
CDP-101 CD player in 1982 with a slide-out tray design for the CD. As it was easy to manufacture and to use, most CD player manufacturers stayed with the tray style ever since. The tray mechanism is also used in many modern
desktop computer
A desktop computer (often abbreviated desktop) is a personal computer designed for regular use at a single location on or near a desk due to its size and power requirements. The most common configuration has a case that houses the power supply ...
cases, as well as the
Philips CD-i
The Compact Disc-Interactive (CD-I, later CD-i) is a digital optical disc data storage format that was mostly developed and marketed by Dutch company Philips. It was created as an extension of CDDA and CD-ROM and specified in the '' Green B ...
,
PlayStation 2
The PlayStation 2 (PS2) is a home video game console developed and marketed by Sony Computer Entertainment. It was first released in Japan on 4 March 2000, in North America on 26 October 2000, in Europe on 24 November 2000, and in Australia on 3 ...
,
Xbox
Xbox is a video gaming brand created and owned by Microsoft. The brand consists of five video game consoles, as well as applications (games), streaming services, an online service by the name of Xbox network, and the development arm by the na ...
and
Xbox 360
The Xbox 360 is a home video game console developed by Microsoft. As the successor to the original Xbox, it is the second console in the Xbox series. It competed with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation ...
. However, there have been some notable exceptions to this common CD tray design.
Vertical loading
During the launch of the first prototype "Goronta" CD player by
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
at the Japanese Audio Fair in 1982, Sony showcased the vertical loading design. Although the Sony prototype design was never put into volume production, the concept was for a time adopted for production by a number of early Japanese CD player manufacturers, including
Alpine/Luxman,
Matsushita under the
Technics brand,
Kenwood and
Toshiba/Aurex. For the early vertical loading players, Alpine sourced their AD-7100 player designs for Luxman, Kenwood and Toshiba (using their Aurex brand). Kenwood added their "Sigma Drive" outputs to this design as a modification. A picture of this early design can be seen on the Panasonic Web site. The vertical loading is similar the one common in
cassette deck
A cassette deck is a type of tape machine for playing and recording audio cassettes that does not have a built-in power amplifier or speakers, and serves primarily as a transport. It can be a part of an automotive entertainment system, a part of a ...
s, where the holder opens, and disc is dropped to it. The holder is closed manually, by motor after pressing a button, or completely automatically. Some CD players combine vertical loading with slot loading due to the disc being drawn further into the disc holder as it closes.
Top loading
![Philips CD 100](https://upload.wikimedia.org/wikipedia/commons/7/74/Philips_CD_100.jpg)
In 1983
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
, at the US and European launch of the CD format, showcased the first top loading CD tray designs with their CD100 CD player. (Philips audio products were sold as
Magnavox
Magnavox (Latin for "great voice", stylized as MAGNAVOX) is an American electronics company that since 1974 has been a subsidiary of the Dutch electronics corporation Philips.
The predecessor to Magnavox was founded in 1911 by Edwin Pridham and ...
in the US at the time.) The design had a clamp on the lid which meant the user had to close this over the CD when it was placed inside the machine. Later,
Meridian
Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to
Science
* Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon
* ...
introduced their MCD "high end" CD player, with Meridian electronics in the Philips CD100 chassis.
Top-loading was adopted on various equipment designs such as mini systems and portable CD players, but among stereo component CD players, only a handful of top-loading models have been made. Examples include
Luxman's D-500 and D-500X series players and
Denon's DP-S1, both launched in 1993.
Top-loading is also common in players intended for broadcast and live sound "DJ" use, such as Technics' SL-P50 (1984–1985) and Technics SL-P1200 (1986–1992). They more closely mimic the physical arrangement and ergonomics of record turntables used in those applications.
The top-loading disc tray design is also used in most
fifth-generation video game
Video games, also known as computer games, are electronic games that involves interaction with a user interface or input device such as a joystick, controller, keyboard, or motion sensing device to generate visual feedback. This fee ...
console
Console may refer to:
Computing and video games
* System console, a physical device to operate a computer
** Virtual console, a user interface for multiple computer consoles on one device
** Command-line interface, a method of interacting with ...
s (the
PlayStation
is a video gaming brand that consists of five home video game consoles, two handhelds, a media center, and a smartphone, as well as an online service and multiple magazines. The brand is produced by Sony Interactive Entertainment, a divisi ...
, the
Sega Saturn
The is a home video game console developed by Sega and released on November 22, 1994, in Japan, May 11, 1995, in North America, and July 8, 1995, in Europe. Part of the fifth generation of video game consoles, it was the successor to the succ ...
and the
3DO Interactive Multiplayer
The 3DO Interactive Multiplayer, also referred to as simply 3DO, is a home video game console developed by The 3DO Company. Conceived by entrepreneur and Electronic Arts founder Trip Hawkins, the 3DO was not a console manufactured by the company ...
), as well as the
Sega Dreamcast
The is a home video game console released by Sega on November 27, 1998, in Japan; September 9, 1999, in North America; and October 14, 1999, in Europe. It was the first sixth-generation video game console, preceding Sony's PlayStation 2, Nint ...
, the
Nintendo GameCube
The is a home video game console developed and released by Nintendo in Japan on September 14, 2001, in North America on November 18, 2001, and in PAL territories in 2002. It is the successor to the Nintendo 64 (1996), and predecessor of the Wii ...
and the
Wii Mini
The Wii ( ) is a home video game console developed and marketed by Nintendo. It was released on November 19, 2006, in North America and in December 2006 for most other regions of the world. It is Nintendo's fifth major home game console, f ...
.
Tray loading with sliding mechanism
The Philips CD303 of 1983-1984 was the first player to adopt tray loading with a sliding play mechanism. Basically as the tray came out to collect the CD, the entire player's transport system also came out as one unit. The
Meridian
Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to
Science
* Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon
* ...
s 200 and 203 players were of this type. They were also the first to use a design in which the audio electronics were in a separate enclosure from the CD drive and pickup mechanism. A similar mechanism is used in slim optical disc drives (also known as slim internal DVD drive, optical drive or DVD burner), which were once commonly used in laptop computers.
Slot loading
Slot loading is the preferred loading mechanism for car audio players. There is no tray that pops out, and a motor is used to assist disc insertion and removal. Some slot-loading mechanisms and changers can load and play back
Mini-CDs without the need of an adapter (such as the original
Wii
The Wii ( ) is a home video game console developed and marketed by Nintendo. It was released on November 19, 2006, in North America and in December 2006 for most other Regional lockout, regions of the world. It is Nintendo's fifth major ho ...
model's standard-sized disc slot being capable of accepting smaller
GameCube Game Disc
Nintendo optical discs are physical media used to distribute video games on three of Nintendo's consoles that followed the Nintendo 64. These are the GameCube Game Disc, Wii Optical Disc, and Wii U Optical Disc. The physical size of a GameCube ...
s) but they may work with limited functionality (a disc changer with a Mini CD inserted will refuse to operate until such disc is removed, for example).
Non-circular CDs cannot be used on such loaders because they cannot handle non-circular discs. When inserted, such discs may become stuck and damage the mechanism. It is also used on some laptop computers, the
original and slim PlayStation 3
The PlayStation 3 (PS3) is a home video game console developed by Sony Interactive Entertainment, Sony Computer Entertainment. The successor to the PlayStation 2, it is part of the PlayStation brand of consoles. It was first released on Novemb ...
, the Wii's original model and its Family Edition and most
eighth-generation video game consoles (the
Wii U
The Wii U ( ) is a home video game console developed by Nintendo as the successor to the Wii. Released in late 2012, it is the first eighth-generation video game console and competed with Microsoft's Xbox One and Sony's PlayStation 4.
The W ...
,
PlayStation 4
The PlayStation 4 (PS4) is a home video game console developed by Sony Interactive Entertainment. Announced as the successor to the PlayStation 3 in February 2013, it was launched on November 15, 2013, in North America, November 29, 2013 in ...
and
Xbox One
The Xbox One is a home video game console developed by Microsoft. Announced in May 2013, it is the successor to Xbox 360 and the third base console in the Xbox series of video game consoles. It was first released in North America, parts of ...
), as well as the
ninth-generation PlayStation 5
The PlayStation 5 (PS5) is a home video game console developed by Sony Interactive Entertainment. Announced as the successor to the PlayStation 4 in April 2019, it was launched on November 12, 2020, in Australia, Japan, New Zealand, North Ame ...
and
Xbox Series X
The Xbox Series X/S are home video game consoles developed by Microsoft. They were both released on November 10, 2020, as the fourth generation Xbox, succeeding the Xbox One. Along with Sony's PlayStation 5, also released in November 2020, t ...
.
Pickup mechanisms
![CD Player Photodetector Chip](https://upload.wikimedia.org/wikipedia/commons/7/7d/CD_Player_Photodetector_Chip.jpg)
Two types of optical tracking mechanisms exist:
* The swing-arm mechanism, originally designed by Philips – the lens moves at the end of an arm, in a manner similar to the tone arm assembly of a
record player
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
. Used in earliest Philips CD players and later replaced with cheaper radial mechanisms.
* The radial mechanism, designed by Sony, which is the one used in most CD players in the 2000s – the lens moves on a radial rail being driven by a rotating gear from a motor or a linear magnetic assembly. The motor or linear magnetic assembly consists of a solenoid mounted to the moving laser assembly, wound over a permanent magnetic field attached to the base of the mechanism. It is also known as three-beam linear tracking.
![Philips 1 beam tracking Laser Optical Assembly](https://upload.wikimedia.org/wikipedia/commons/5/51/Philips_1_beam_tracking_Laser_Optical_Assembly.jpg)
The swing-arm mechanism has a distinctive advantage over the other in that it does not "skip" when the rail becomes dirty. The swing arm mechanisms tend to have a much longer life than their radial counterparts. The main difference between the two mechanisms is the way they read the data from the disc. The swing-arm mechanism uses a magnetic coil wound over a permanent magnet to provide the tracking movement to the laser assembly in a similar way a
hard drive
A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...
moves its head across the data tracks. It also uses another magnetic movement mechanism attached to the focusing lens to focus the laser beam on the disc surface. By operating the tracking or the focus actuators, the laser beam can be positioned on any part of the disc.
This mechanism employs a single laser beam and a set of four photodiodes to read, focus and keep track of the data coming from the disc.
![CD Player focusing lens assembly](https://upload.wikimedia.org/wikipedia/commons/1/1f/CD_Player_focusing_lens_assembly.jpg)
The linear tracking mechanism uses a motor and reduction gears to move the laser assembly radially across the tracks of the disc and it also has a set of six coils mounted in the focusing lens over a permanent magnetic field. One set of two coils moves the lens closer to the disc surface, providing the focusing motion, and the other set of coils moves the lens radially, providing a finer tracking motion. This mechanism uses the three-beam tracking method in which a main laser beam is used to read and focus the data track of the disc using three or four photodiodes, depending on the focus method, and two smaller beams read the adjacent tracks at each side to help the servo keep the tracking using two more "helper"
photodiode
A photodiode is a light-sensitive semiconductor diode. It produces current when it absorbs photons.
The package of a photodiode allows light (or infrared or ultraviolet radiation, or X-rays) to reach the sensitive part of the device. The packag ...
s.
Mechanical components
![Dismantled Philips EXP2582 portable CD player](https://upload.wikimedia.org/wikipedia/commons/a/aa/Dismantled_Philips_EXP2582_portable_CD_player.jpg)
A CD player has three major mechanical components : a drive motor, a
lens
A lens is a transmissive optical device which focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses (''elements''), ...
system or pickup head, and a tracking mechanism.
The drive motor (also called spindle) spins the disc to a scanning velocity of 1.2–1.4 m/s (
constant linear velocity
In optical storage, constant linear velocity (CLV) is a qualifier for the rated speed of an optical disc drive, and may also be applied to the writing speed of recordable discs. CLV implies that the angular velocity (i.e. rpm) varies during an ...
) – equivalent to approximately 500 RPM at the inside of the disc, and approximately 200 RPM at the outside edge. (A disc played from beginning to end slows its rotation rate during playback.) The tracking mechanism moves the lens system along the spiral tracks in which information is encoded, and the lens assembly reads the information using a
laser beam
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
produced by a
laser diode
file:Laser diode chip.jpg, The laser diode chip removed and placed on the eye of a needle for scale
A laser diode (LD, also injection laser diode or ILD, or diode laser) is a semiconductor device similar to a light-emitting diode in which a di ...
. The laser reads information by focusing a beam on the CD, which is reflected off the disc's mirrored surface back to a
photodiode
A photodiode is a light-sensitive semiconductor diode. It produces current when it absorbs photons.
The package of a photodiode allows light (or infrared or ultraviolet radiation, or X-rays) to reach the sensitive part of the device. The packag ...
array sensor. The sensor detects changes in the beam, and a digital processing chain interprets these changes as binary data. The data are processed, and eventually converted to
sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the ...
using a
digital-to-analog converter
In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function.
There are several DAC architec ...
(DAC).
A TOC or Table of Contents is located after the "lead-in" area of the disc, which is located in an inner ring of the disc, and contains roughly five kilobytes of available space. It is the first information that the player reads when the disc is loaded in the player and contains information on the total number of audio tracks, the running time on the CD, the running time of each track, and other information such as ISRC and the format structure of the disc. The TOC is of such vital importance for the disc that if it is not read correctly by the player, the CD could not be played back. That is why it is repeated 3 times before the first music program starts. The "lead out" area in the end (the outer peripheral) of the disc tells the player that disc has come to an end.
CD player features
CD players can employ a number of ways to improve performance, or reduce component count or price. Features such as oversampling, one-bit DACs, dual DACs, interpolation (error correction), anti-skip buffering, digital and optical outputs are, or were, likely to be found. Other features improve functionality, such as track programming, random play and repeat, or direct track access. Yet others are related to the CD player's intended target, such as anti-skip for car and portable CD players, pitch control and queuing for a DJ's CD player, remote and system integration for household players. Description of some features follows:
*''
Oversampling
In signal processing, oversampling is the process of sampling a signal at a sampling frequency significantly higher than the Nyquist rate. Theoretically, a bandwidth-limited signal can be perfectly reconstructed if sampled at the Nyquist rate o ...
'' is a way to improve the performance of the low pass filter present at the output of most CD players. By using a higher sampling frequency, a multiple of the 44.1 kHz used by CD encoding, it can employ a filter with much lower requirements.
*''
One-bit DACs'' were less expensive than other types of DACs, while providing similar performance.
*''Dual DACs'' were sometimes advertised as a feature because some of the early CD players used a single DAC, and switched it between channels. This required additional supporting circuits, possibly degrading sound quality.
*''Anti-skip or Antishock'', is a way for the CD player to avoid interrupting the audio output when mechanical shock is experienced by the disc playback mechanism. It consists of an additional data processor and a
RAM chip installed on the player that reads the disc at double speed and stores various frames of audio data in a RAM
memory buffer
In computer science, a data buffer (or just buffer) is a region of a memory used to temporarily store data while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device (such a ...
for later decoding. Some players may compress the audio data prior to buffering to use lower capacity (and less expensive) RAM chips. Typical players can store about 44 seconds of audio data on a 16 mbit RAM chip.
Portable CD players
Small portable players
![Discman D121](https://upload.wikimedia.org/wikipedia/commons/d/d5/Discman_D121.jpg)
A
portable CD player
A portable CD player is a portable audio player used to play compact discs. The first audio player released was the Discman D-50 by Sony.Lungu, R"History of the Portable Audio Player." 2008-11-27.
Features
The basic features of a portable CD ...
is a
portable audio player
A portable audio player is a personal mobile device that allows the user to listen to recorded audio while mobile. Sometimes a distinction is made between a ''portable'' player, battery-powered and with one or more small loudspeakers, and a ''pers ...
used to play
compact disc
The compact disc (CD) is a Digital media, digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then rele ...
s. Portable CD players are powered by batteries and they have a 1/8" headphone jack into which the user plugs a pair of
headphone
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an au ...
s. The first portable CD player released was the
D-50 by
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
.
[Lungu, R]
"History of the Portable Audio Player."
2008-11-27. The D-50 was made available on the market in 1984, and adopted for Sony's entire portable
CD player line.
In 1998, portable
MP3 player
A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. The data is typically stored o ...
s began to compete with portable CD players. After
Apple Computer
Apple Inc. is an American multinational technology company headquartered in Cupertino, California, United States. Apple is the largest technology company by revenue (totaling in 2021) and, as of June 2022, is the world's biggest company b ...
entered the music player market with its
iPod
The iPod is a discontinued series of portable media players and multi-purpose mobile devices designed and marketed by Apple Inc. The first version was released on October 23, 2001, about months after the Macintosh version of iTunes ...
line, within ten years it became the dominant seller of portable
digital audio
Digital audio is a representation of sound recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical samples in a continuous sequence. For example, in CD audio, sa ...
players, "...while former giant
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
(maker of the
ortableWalkman
Walkman, stylised as , is a brand of portable audio players manufactured and marketed by Japanese technology company Sony since 1979. The original Walkman was a portable cassette player and its popularity made "walkman" an unofficial term for ...
and
DDiscman
Discman was Sony's brand name for portable CD players. The first Discman, the Sony D-50 or D-5 (depending on region), was launched in 1984. The brand name changed to CD Walkman, initially for Japanese lineups launched between October 1997 and Ma ...
asstruggling." This market shift was initiated when the first portable digital audio player, the
Rio digital music player
Rio was the brand name of a line of digital audio players and related audio products. It was a pioneer of the DAP ("MP3 player") industry when it released "Diamond Rio" player in 1998 that was the impetus for an infamous lawsuit. Various music p ...
, was introduced. The 64 MB Rio MP3 player enabled users to store about 20 songs.
One of the benefits of the Rio over portable CD players was that since the Rio had no moving parts, it offered skip-free playback.
Since 1998, the price of portable digital audio players has dropped and the storage capacity has increased significantly. In the 2000s, users can "carry
heir
Inheritance is the practice of receiving private property, titles, debts, entitlements, privileges, rights, and obligations upon the death of an individual. The rules of inheritance differ among societies and have changed over time. Officiall ...
entire music collection in a
igital audioplayer the size of a cigarette package."
The 4 GB iPod, for example, holds over 1,000 songs.
Boomboxes
![Sony Boombox circa 2005](https://upload.wikimedia.org/wikipedia/commons/8/80/Sony_Boombox_circa_2005.JPG)
A
boombox
A boombox is a transistorized portable music player featuring one or two cassette tape recorder/players and AM/FM radio, generally with a carrying handle. Beginning in the mid 1980s, a CD player was often included. Sound is delivered through ...
is a common term for a portable
cassette
Cassette may refer to:
Technology
* Cassette tape (or ''musicassette'', ''audio cassette'', ''cassette tape'', or ''tape''), a worldwide standard for analog audio recording and playback
** Cassette single (or "Cassingle"), a music single in th ...
and AM/FM radio that consists of an amplifier, two or more
loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or " ...
s and a carrying handle. Beginning in the 1990s, boomboxes typically included a CD player. The boombox CD player is the only type of CD player which produces sound audible by the listener independently, without the need for
headphones
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an au ...
or an additional amplifier or speaker system. Designed for portability, boomboxes can be powered by
batteries as well as by line current. The boombox was introduced to the American market during the mid-1970s. The desire for louder and heavier bass led to bigger and heavier boxes; by the 1980s, some boomboxes had reached the size of a
suitcase
A suitcase is a form of luggage. It is a rectangular container with a handle typically used to carry one's clothes and other belongings while traveling. The first suitcases appeared in the late 19th century due to the increased popularity of ma ...
. Most boomboxes were battery-operated, leading to extremely heavy, bulky boxes.
Most boomboxes from the 2010s typically include a CD player compatible with
CD-R
CD-R (Compact disc-recordable) is a digital optical disc storage format. A CD-R disc is a compact disc that can be written once and read arbitrarily many times.
CD-R discs (CD-Rs) are readable by most CD readers manufactured prior to the i ...
and
CD-RW
CD-RW (Compact Disc-Rewritable) is a digital media, digital optical disc data storage device, storage format introduced in 1997. A CD-RW compact disc (CD-RWs) can be written, read, erased, and re-written.
CD-RWs, as opposed to CDs, require ...
, which allows the user to carry their own music compilations on a higher fidelity medium. Many also permit iPod and similar devices to be plugged into them through one or more auxiliary input jacks. Some also support formats such as
MP3
MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
and
WMA. Another modern variant is a DVD player/boombox with a top-loading CD/
DVD
The DVD (common abbreviation for Digital Video Disc or Digital Versatile Disc) is a digital optical disc data storage format. It was invented and developed in 1995 and first released on November 1, 1996, in Japan. The medium can store any kind ...
drive and an
LCD video screen in the position once occupied by a cassette deck. Many models of this type of boombox include inputs for external video (such as
television
Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertisin ...
broadcasts) and outputs to connect the DVD player to a full-sized television.
DJ equipment
Disc jockey
A disc jockey, more commonly abbreviated as DJ, is a person who plays recorded music for an audience. Types of DJs include Radio personality, radio DJs (who host programs on music radio stations), club DJs (who work at a nightclub or music f ...
s (DJs) who are playing a mix of
song
A song is a musical composition intended to be performed by the human voice. This is often done at distinct and fixed pitches (melodies) using patterns of sound and silence. Songs contain various forms, such as those including the repetitio ...
s at a
dance club
Dance is a performing art form consisting of sequences of movement, either improvised or purposefully selected. This movement has aesthetic and often symbolic value. Dance can be categorized and described by its choreography, by its repertoire ...
,
rave
A rave (from the verb: '' to rave'') is a dance party at a warehouse, club, or other public or private venue, typically featuring performances by DJs playing electronic dance music. The style is most associated with the early 1990s dance mus ...
, or
nightclub
A nightclub (music club, discothèque, disco club, or simply club) is an entertainment venue during nighttime comprising a dance floor, lightshow, and a stage for live music or a disc jockey (DJ) who plays recorded music.
Nightclubs gener ...
create their dance mixes by having songs playing on two or more sound sources and using a
DJ mixer
A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the mixer to make seamless transitions from one song to another when they are playing records at a dance clu ...
to transition seamlessly between songs. In the 1970s
disco
Disco is a genre of dance music and a subculture that emerged in the 1970s from the United States' urban nightlife scene. Its sound is typified by four-on-the-floor beats, syncopated basslines, string sections, brass and horns, electric pia ...
era, DJs typically used two
record players
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
. From the 1980s to the 1990s, two
compact cassette
The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens ...
players became a popular sound source for DJs.
In subsequent decades, DJs shifted to CDs and then to
digital audio player
A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. The data is typically stored o ...
s. DJs who use CDs and CD players typically use specialized DJ CD players that have features not available on regular CD players.
DJs who are performing "
scratching
Scratching, sometimes referred to as scrubbing, is a DJ and turntablist technique of moving a vinyl record back and forth on a turntable to produce percussive or rhythmic sounds. A crossfader on a DJ mixer may be used to fade between two record ...
"–the creation of rhythmic sounds and sound effects from sound recordings–traditionally used
vinyl record
A phonograph record (also known as a gramophone record, especially in British English), or simply a record, is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts nea ...
s and
turntables
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
. In the 2010s, some specialized DJ CD players can be used to create the same "scratching" effects using songs on CDs.
See also
*
Compact Cassette
The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens ...
*
Compact Disc
The compact disc (CD) is a Digital media, digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then rele ...
*
Hi-Fi
*
High-end audio
High-end audio is a class of consumer home audio equipment marketed to audiophiles on the basis of high price or quality, and esoteric or novel sound reproduction technologies. The term can refer simply to the price, to the build quality of the ...
*
Jukebox
A jukebox is a partially automated music-playing device, usually a coin-operated machine, that will play a patron's selection from self-contained media. The classic jukebox has buttons, with letters and numbers on them, which are used to selec ...
*
List of compact disc player manufacturers
*
MP3 CD
*
Optical disc drive
In computing, an optical disc drive is a disc drive that uses laser light or electromagnetic waves within or near the visible light spectrum as part of the process of reading or writing data to or from optical discs. Some drives can only r ...
*
Radio cassette
*
Radio receiver
In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. Th ...
, includes information about Radio CD/DVD.
*
Record changer
A record changer or autochanger is a device that plays several phonograph records in sequence without user intervention. Record changers first appeared in the late 1920s, and were common until the 1980s.
History
The record changer with a stepped ...
*
Transport (recording)
A transport is a device that handles a particular physical storage medium (such as magnetic tape, audio CD, CD-R, or other type of recordable media) itself, and extracts or records the information to and from the medium, to (and from) an outboard ...
References
External links
The Inner Workings of CD/DVD DrivesWeCanFigureThisOut.org
The Audio Circuitnbsp;— a complete list of CD-player brands
{{Compact disc navbox
Player
Player may refer to:
Role or adjective
* Player (game), a participant in a game or sport
** Gamer, a player in video and tabletop games
** Athlete, a player in sports
** Player character, a character in a video game or role playing game who ...
Audio players
Consumer electronics
Products introduced in 1982
Digital audio
Japanese inventions