A compact disc player or CD player is an electronic device that plays audio CDs. CD player uses optical systems with a high precision laser to read the data. A CD player uses a laser beam to determine the lengths of a series of ridges inside a compact disc. Infrared light from a solid-state laser is sent through several lenses, a polarizing beam splitter, and a special polarizing device called a quarter-wave plate. It's then focused through the clear plastic surface of the compact disc and onto the shiny aluminum layer inside the disc. The compact disc player as a sound reproduction device fulfills the loop begun in the recording studio, returning the audio signal back to its original analog form. The compact disc player contains two main subsystems: the audio data processing system and the servo/control system. The servo, control, and display system orchestrate the mechanical operation of the player and include such items as the spindle motor, auto-tracking, lens focus, and the user interface. The audio data processing section covers all other player processes. The main advantage of CDs over record players is that no mechanical component, such as a stylus, ever touches the surface of the disk, so the pattern remains intact. There is no wear on the disk and no degradation in the sound after repeated playing. Computer processing can be used to detect and remove imperfections and noise. Even though you can't record directly onto a CD, the duplication of the music is exact from one reproduction to the next. Since the introduction of the compact disc player in 1982, the market has seen three generations of players. First generation players were characterized by multi-bit DAC's used with brickwall reconstruction filters. Second generation players used the same multi-bit DAC's but took advantage of digital oversampling filters placed upstream of the DAC along with a gentle analog reconstruction filter. Finally, current players make use of low-bit DAC's along with oversampling filters and the gentle analog output filter. CD players read CD-DA music tracks, but may also decode MP3 files and other compressed audio formats. CD players can be found in home stereo systems, car audio systems and personal computers, and are also available as portable devices.
References: Wikipedia article "Compact disc player", Adrian Birka "How a CD Player Works", MSU Science Theatre, Louis Bloomfield "How Things Work - Compact Disc Players", Grant Erickson "A Fundamental Introduction to the Compact Disc Player"
Listings on Audio electronics : CD players and recorders : CD players
Manufacturer of CD and DVD players, DA converters, tuners, and power and integrated amplifiers. Germany.
- Coby Electronics Corp.
Manufacturer of MP3 players, CD players, DVD players, portable TF DVD Player, cassette players, headphones, earphones, mini-speakers, telephones, clock radios and recorders, radio cassette players, and accessories. USA.
- Cyrus Electronics
Manufacturer of high-end audio and visual equipment including loudspeakers, CD and DVD players, AV systems, amplifiers, power supplies, and accessories. UK.
- Maxsome Corp Ltd.
Manufacturer and exporter of audio/video products such as clock radios, shower radios, portable cassette recorders, MP3 players, CD players, microphones, CD+G and DVD karaoke systems. Hong Kong, China.
- Shenzhen Wenxing Technology Co., Ltd.
Manufactures and exports electronic products such as telephones, alarm clock radio, CD sound system, portable DVD, mp3, and boomboxes. China.