A Compact Disc player (often written as compact disc player), or CD player, is an electronic device which plays audio Compact Discs. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is Super Audio CD ( SACD) is a read-only optical audio disc format that can provide higher fidelity digital audio reproduction than the Red A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio CD players are often installed into home stereo systems, car audio systems, and personal computers. Stereophonic sound, commonly called stereo, is the reproduction of Sound, using two or more independent audio channels through a Symmetrical Car audio/video (car AV is a term used to describe the sound or video system fitted in an Automobile. A personal computer ( PC) is any Computer whose original sales price size and capabilities make it useful for individuals and which is intended to be operated They are also manufactured as portable devices. Modern units support other formats in addition to CDs; such as DVDs, CD-ROMs with audio files and video CDs. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is CD-ROM (an initialism of "Compact Disc Read-Only Memory " is a pre-pressed Compact Disc that contains data accessible to but not writable DJs often use players with adjustable playback sampling rate to alter the pitch of the music programme. A disc jockey (also known as DJ or deejay) is a person who selects and plays recorded music for an audience Pitch represents the perceived Fundamental frequency of a sound Many modern CD players also include the capability to play MP3 CDs. An MP3 CD is a Compact disc (usually a CD-R or CD-RW) that contains Digital audio in the MP3 File format. CD playback functionality is also available on all modern CD-ROM/DVD-ROM drive equipped computers as well as on DVD players and CD-ROM/DVD-ROM based game consoles.
Contents |
Physical description
Many CD players are contained in a plastic and steel casing which also houses the electrical system and the user interface. The user interface (or Human Computer Interface) is the aggregate of means by which people&mdash the users '&mdash interact with the System
The housing of a portable CD player also contains ports used to connect the player to a powered or unpowered speaker, headphones and/or a power system (see electrical wiring in the United States or in the UK). In Electronics, a jack is generally a Socket (female connector but because the related term Jack plug is often abbreviated to just jack confusion can Powered speakers (or active speakers) are speakers that have built-in Amplifiers They can be connected directly to a Mixing console or Sound Powered speakers (or active speakers) are speakers that have built-in Amplifiers They can be connected directly to a Mixing console or Sound Headphones (also known as earphones, earbuds, stereophones, headsets) are a pair of small Loudspeakers or less commonly a single Electrical wiring in general refers to conductors used to carry Electricity and their accessories The modern UK standards and regulations for electrical wiring no longer differ substantially from those in other European countries. A portable CD player generally contains an internal power source in the form of batteries. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy
The housing of a stand-alone CD player contains speakers and perhaps a radio and/or tape deck. Radio is the transmission of signals by Modulation of electromagnetic waves with frequencies below those of visible Light. This article deals mainly with analog tape recorders for audio applications information on digital recording, recording of video signals, and CD players used in component audio systems contain a power source, the user interface, and numerous ports to connect the player to the various parts of an audio system.
Tray Design Evolution
Tray Loading
Sony released the world's first CD Player called the CDP-101[1] in 1982 utilising a slide-out tray design for the CD. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with As it was easy to use and manufacture, most CD player tray designs had followed this style of tray ever since. However there have been some notable exceptions.
Vertical Loading
During the launch of the first prototype CD player 'Goronta'[2] by Sony at the Japanese Audio Fair in 1982, Sony showcased the vertical loading design of the CD player. is a multinational conglomerate corporation headquartered in Minato Tokyo, Japan, and one of the world's largest Media conglomerates with Although the prototype's design was never really put into actual production, it 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. Luxman is a Brand name of Japanese, a company that produces a variety of audio electronic products ( is a multinational conglomerate manufacturing company headquartered in Tokyo, Japan. For the early vertical loading players, Alpine sourced their AD-7100 player designs for Luxman[3], 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 website. [4]
Top Loading
In 1983 at the launch of the CD format, Philips with their FD-3000 CD player (sold as Magnavox in the US), showcased the first top loading CD tray designs. Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc. Magnavox ( Latin for "great voice" is an American Electronics company founded by Edwin Pridham and Peter L 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. Apart from having no motors accessing a movable tray, thus interfering with the player's sound quality, as the disc was clamped right down within the player, it implied better sound quality. This was one of the primary reasons manufacturer Meridian created their MCD CD player,[5] whose chassis design was derived from Philips FD-1000. Boothroyd Stuart Meridian is a British manufacturer of high-performance High-fidelity audio and video components and systems Koninklijke Philips Electronics NV ( Royal Philips Electronics Inc.
Apart from being adopted on various stereo equipment designs such as mini components, over the years only a handful of hi-fi quality top loading tray CD players had been made. The most notable were Luxman's D-500 and D-500X series[6] players, and Denon's DP-S1,[7] both launched in 1993. Luxman is a Brand name of Japanese, a company that produces a variety of audio electronic products is a Japanese Electronics company that originated Digital Audio technology while specializing in manufacturing of High-fidelity professional and consumer
Tray Load with Sliding Mechanism
Meridians 200 and 203 players were the first players to adopt tray loading with sliding play mechanism. Boothroyd Stuart Meridian is a British manufacturer of high-performance High-fidelity audio and video components and systems Basically as the tray came out to collect the CD, the entire player's transport system also came out as one unit. The players were also the first to utilise the CD Transport design whereby the audio electronics were separate from the CD drive mechanism itself to reduce jitter and distortion. Jitter is an unwanted variation of one or more characteristics of a periodic signal in Electronics and Telecommunications. A distortion is the alteration of the original shape (or other characteristic of an object image sound waveform or other form of information or representation
Tray Load with Dampers
A few companies produced CD players with dampened trays. The dampers were rubber grommets built into the tray to reduce distortion. Yamaha's CDX-1000 CD player was a good example of this design.
Slot Loading
Slot loading is the preferred loading mechanism for car audio head units, the Apple MacBook, amongst other audio players. The MacBook is a Macintosh Notebook computer by Apple Inc that replaced the iBook G4 series There is no tray that pops out, and a motor is used to assist disc insertion and removal. Mini-CDs and non-circular CDs may have troubles with insertion and/or ejection.
Function
A CD player has three major components: a drive motor, a lens system, and a tracking mechanism. A lens is an optical device with perfect or approximate Axial symmetry which transmits and refracts Light, converging or diverging The drive motor rotates the disc between 200 and 500 revolutions per minute. The tracking mechanism moves the lens system along the spiral tracks in which information is encoded, and the lens reads the information using a laser beam. A laser is a device that emits Light ( Electromagnetic radiation) through a process called Stimulated emission. The laser reads information by focusing a beam on the CD, which is reflected back to a sensor. The sensor detects changes in the beam, and interprets these changes to read the data. This data is output as sound using a digital-to-analog converter (DAC). Sound' is Vibration transmitted through a Solid, Liquid, or Gas; particularly sound means those vibrations composed of Frequencies In Electronics, a digital-to-analog converter ( DAC or D-to-A) is a device for converting a digital (usually binary code to an Analog signal
A subcode in an audio CD contains information on the total number of audio tracks, the running time on the CD, running time of each track, and other information. Besides digital audio a Compact disc contains digital data called subcode or subchannel data, which is multiplexed with the digital audio This information allows the drive motor to speed up or slow down as needed to read data at a constant rate.
Interface
The interface of a CD player does not vary widely from manufacturer to manufacturer. It is usually composed of a few buttons and a display device. A push-button (often simply " button " or " pushbutton " is a simple Switch mechanism for controlling some aspect of a Machine A display device is an Output device for presentation of Information for Visual or Tactile reception acquired stored or transmitted Common buttons include play, pause, stop, advance/fast forward, back/rewind and, in the case of a multiple-CD player, disk selection. The display may provide information such as track number, track time, disk number in the case of multiple-CD changers and CD-Text. CD-Text is an extension of the Red Book Compact Disc specifications standard for Audio CDs It allows for storage of additional information (e
CD changer
A CD changer holds multiple Compact Discs, usually in a cartridge, and allows the user to access (or play) any of them, one at a time. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio CD changers are commonly found in home cinema systems, cars, and less often in computer equipment. Home cinema, also called home theater, are entertainment systems that seek to reproduce cinema quality video and audio in a private home A computer is a Machine that manipulates data according to a list of instructions.
Prior art
Prior to real CD changers being introduced, an attempt was made to copy the double cassette players found in many audio systems. The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a Magnetic tape sound As a result, devices with two separate, fully functional CD players were made. Very few cassette changers were produced, mainly because a double-cassette deck could copy from one cassette to another. Double-CD decks, on the other hand, did not have this copy functionality since recordable CDs were not commercially available. Therefore, the shift to changers was swift, removing the need for double CD players.
Main types of CD changers
External cartridge
External cartridge CD changers have one or more cartridges that the user loads with up to 12 different CDs (depending on manufacturer) and then inserts into the CD changer. In various types of electronic equipment a cartridge can refer one method of adding different functionality or content (e The CD changer can then remove one CD at a time for playing. This type of player is commonly found in vehicles because the user can switch easily between large amounts of media contained in different cartridges.
Internal cartridge
Internal cartridge CD changers work on the same basic principle as external cartridge players, except the cartridge never leaves the CD player. This type of CD player accepts multiple CDs through a single slot and stores them internally.
Carousel
A carousel type CD changer consists of a circular platter that holds three or more CDs. Traditional carousel CD players hold three, five, or seven discs on a flat carousel tray. The carousel ejects to allow access to the CDs. Once back inside, the CD changer can rotate the carousel to access all of the CDs. Such carousel CD changers often allow the user to rotate the carousel while open, and change all CDs if no CDs are currently playing, or to eject the carousel while one CD is playing to change any CDs accessible from that position. Another type of carousel CD player is the mega-disc or "jukebox" CD players as they are also known. They usually hold anywhere from 50 to 300 discs. The mega-disc CD player holds its discs in a vertical position in slots that located 360 degrees around the carousel. When a disc is selected to be played, the carousel rotates so that the disc can be picked up by a pickup mechanism and placed in CD playback unit. Mega-disc CD players generally have a means of entering in titles of the CDs stored inside them, such as telephone style letter input system found on the remote control, a full letter keypad on the unit, or by use of an external keyboard attached to the unit. Many units can also automatically obtain the title of a CDs if it contains CD-Text info stored on it. CD-Text is an extension of the Red Book Compact Disc specifications standard for Audio CDs It allows for storage of additional information (e
Evolution
Digital audio players have surpassed the concept of CD changers. A digital audio player, more commonly referred to as an MP3 player, is a Consumer electronics device that stores organizes and plays audio files Some For example, the first generation iPod can hold an equivalent of 50 discs (1000 songs)[8] with a 128k bit rate for each song; thereby, the iPod is 1/10 the size of a CD changer cartridge, and about 1/20 the size of a carousel changer. iPod is a popular brand of Portable media players designed and marketed by Apple Inc Solid state flash-based digital audio players have rendered compact discs and thus CD changers obsolete for some purposes. Solid-state Electronic components devices and systems are based entirely on the Semiconductor, such as Transistors Microprocessor chips and While digital audio players often use a lossy compression scheme, they usually can accept lossless formats such as WAV (PCM) as well, matching the quality of CD audio. A lossy compression method is one where compressing data and then decompressing it retrieves data that may well be different from the original but is close enough to be useful WAV (or WAVE) short for Waveform Audio format, is a Microsoft and IBM Audio file format standard for storing an audio bitstream on
Computer-based changers
CD-ROM changers existed in the early 1990s as an expensive external drive, often connecting through the SCSI interface. The changer concept is seen on the computer as one drive letter for each corresponding disc number. The computer references the disc by its drive letter, and the changer machine loads the disc transparently.
Changers are often used by enterprises hosting software (i. e. Encarta Encyclopedia, library software) on a server, at a time when the mean hard drive capacity was measured in hundreds of megabytes. The changer has been supplanted by exponential growth of hard drive storage densities, enabling several CD's worth of data to be stored on the drive and replacing the changer for such purposes.
Today (2007) the CD changer is still an available automobile accessory capable of reading up to 12 audio CDs, CD-Rs, DVDs, or VCDs per magazine. A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio A CD-R ( C ompact D isc- R ecordable is a variation of the Compact Disc invented by Philips and Sony. DVD (also known as " Digital Versatile Disc " or " Digital Video Disc " - see Etymology)is
See also
- Compact Cassette
- Compact Disc
- Hi-Fi
- High-end audio
- Jukebox
- MP3 CD
- Optical disc drive
- Radio cassette
- Radio receiver, includes information about Radio CD. The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a Magnetic tape sound A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio High fidelity or hi-fi reproduction is a term used by home stereo listeners and home audio enthusiasts ( Audiophiles to refer to high-quality reproduction High-end audio is a term used to describe higher priced and/or higher quality audio equipment jukebox is a partially automated music-playing device usually a Coin -operated machine that can play specially selected songs from self-contained media An MP3 CD is a Compact disc (usually a CD-R or CD-RW) that contains Digital audio in the MP3 File format. In Computing, an optical disc drive ( ODD) is a Disk drive that uses Laser light or electromagnetic waves near the Light spectrum The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a Magnetic tape sound This article is about a radio receiver for other uses see Radio (disambiguation.
- Record changer
- Transport (recording)
Notes
- ^ CDP-101 The first Compact Disc Audio CD Player from 1982 (2007). A record changer or autochanger is a device that plays multiple Gramophone records in sequence without user intervention 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 Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.
- ^ Sony History (2007). Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.
- ^ Luxman DX-104 CD Player (2007). Retrieved on 2007-02-17. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1500 - Battle of Hemmingstedt. 1600 - Philosopher Giordano Bruno is burned alive at Campo de' Fiori
- ^ Panasonic History - Innovative Products - 1982 - CD Player (2007). Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.
- ^ :0 Meridian CD History (2007). Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.
- ^ Luxman D-500X (in Japanese) (2007). Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.
- ^ Denon Museum - Model History - 1993 - DP-S1 (in Japanese) (2007). Retrieved on 2007-02-05. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1576 - Henry of Navarre converts to Roman Catholicism in order to ensure his right to the throne of France.
- ^ Apple Presents iPod
References
- The Audio Circuit A complete list of all brands who've developed CD-players
- "How CDs Work" at Howstuffworks.com
- Technical Information about CD players
- Info on mega-disc CD players
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic