A recording head is the physical
interface
Interface or interfacing may refer to:
Academic journals
* ''Interface'' (journal), by the Electrochemical Society
* '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics''
* '' Int ...
between a
recording
A record, recording or records may refer to:
An item or collection of data Computing
* Record (computer science), a data structure
** Record, or row (database), a set of fields in a database related to one entity
** Boot sector or boot record, ...
apparatus and a moving
recording medium
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 consid ...
. Recording heads are generally classified according to the
physical
Physical may refer to:
*Physical examination
In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally co ...
principle that allows them to impress their
data
In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted ...
upon their medium. A recording head is often mechanically paired with a
playback head
A tape head is a type of transducer used in tape recorders to convert electrical signals to magnetism, magnetic fluctuations and vice versa. They can also be used to read Credit card, credit/Debit card, debit/Gift card, gift cards because the stri ...
, which, though proximal to, is often discrete from the record head.
Types
The two most common forms of recording head are:
* Magnetic - Magnetic recording heads use the principles of
electromagnetism
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of a ...
to
coerce
Coercion () is compelling a party to act in an involuntary manner by the use of threats, including threats to use force against a party. It involves a set of forceful actions which violate the free will of an individual in order to induce a desi ...
a
paramagnetic
Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, d ...
recording medium, such as
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
oxides
An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the E ...
, to orient in a readable manner such as
magnetic tape
Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magne ...
. Record heads are constructed of laminated
permalloy
Permalloy is a nickel–iron magnetic alloy, with about 80% nickel and 20% iron content. Invented in 1914 by physicist Gustav Elmen at Bell Telephone Laboratories, it is notable for its very high magnetic permeability, which makes it useful as a ...
,
ferrite, or
sendust
Sendust is a magnetic metal powder that was invented by Hakaru Masumoto at Tohoku Imperial University in Sendai, Japan circa 1936 as an alternative to permalloy in inductor applications for telephone networks. Sendust composition is typically 85% ...
. As of 2006, this is the most dominant type of head in use.
* Optical - Optical recording heads use the principles of
optics
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviole ...
and
light
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 tera ...
to impart
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...
on a recording medium, which accepts the
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of heat a ...
in a readable manner, e.g. by
melting
Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which inc ...
or
photography
Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed ...
.
Note that
Magneto-optical
A magneto-optical drive is a kind of optical disc drive capable of writing and rewriting data upon a magneto-optical disc. Both 130 mm (5.25 in) and 90 mm (3.5 in) form factors exist. In 1983, just a year after the introduc ...
recording, though using optics and
heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is al ...
, should properly be considered a magnetic process, since the data stored on magneto-optical media is stored magnetically.
Earlier systems, such as
phonograph
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 ...
records, used mechanical heads known as
styli
A stylus (plural styli or styluses) is a writing utensil or a small tool for some other form of marking or shaping, for example, in pottery. It can also be a computer accessory that is used to assist in navigating or providing more precision w ...
to physically cut grooves in the recording medium, in a configuration (of size, width, depth and position) recoverable as
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 ...
.
Photo gallery
Image:D6-VTR-Scanner.jpg , D6 HDTV VTR
D6 HDTV VTR is SMPTE videocassette standard. A D6 VTR can record and playback HDTV video uncompressed. The only D6 VTR product is the Philips, now Thomson's Grass Valley's Media Recorder, model DCR 6024, also called the D6 Voodoo VTR. The VT ...
Scanner and video head, removed
Image:D6-VTR-Tape Deck-inside.jpg , Inside a D6 HDTV VTR Tape Deck, VTR Scanner and video head in place.
Image:Bcn-scanner-head.jpg, Type B videotape
1–inch type B VTR (designated Type B by SMPTE) is a reel-to-reel analog recording video tape format developed by the Bosch Fernseh division of Bosch in Germany in 1976. The magnetic tape format became the broadcasting standard in continen ...
video Scanner Head
Image:BCN-20-VTR-CLOSEUP.jpg, Type B VTR, BCN 20 Tape Desk and video Scanner
Image:Ampex-quad-video-head.jpg, Quadruplex videotape
2-inch quadruplex videotape (also called 2″ quad video tape or quadraplex) was the first practical and commercially successful analog recording video tape format. It was developed and released for the broadcast television industry in 1956 by A ...
Ampex AVR-2 Video Head
Image:Sony U-Matic VO-5850 Video head - slip-ring flying head pickup with dust cover.JPG , 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 ...
U-Matic Video head
Image:Ampex recorder internals.jpg , Ampex
Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff as a spin-off of Dalmo-Victor. The name AMPEX is a portmanteau, created by its founder, which stands for Alexander M. Poniatoff Excellence.AbramsoThe History ...
audio recorder
Image:VHS diagram.svg , VHS heads
Image:NAGRA--TYPE3---PL-GR.jpg , Nagra
Nagra is a brand of portable audio recorders produced from 1951 in Switzerland. Beginning in 1997 a range of high-end equipment aimed at the audiophile community was introduced, and Nagra expanded the company’s product lines into new markets. ...
audio heads: erase, record and play
Image:SONY_UVW-1400P_Betacam_SP_video_heads_01.jpg, Exposed head gap due to excessive head-wear. 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 ...
UVW Betacam SP video heads
See also
*
Analog recording
Analog recording is a technique used for the recording of analog signals which, among many possibilities, allows analog audio for later playback.
Analog audio recording began with mechanical systems such as the phonautograph and phonograph. ...
*
Cassette demagnetizer
A cassette demagnetizer is a device that removes the magnetism, magnetic field that accumulates during the use of Compact audio cassette, audio cassettes in cassette decks.
The passage of magnetically charged tape over the metallic parts of 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 ...
*
Digital recording
In digital recording, an audio or video signal is converted into a stream of discrete numbers representing the changes over time in air pressure for audio, or chroma and luminance values for video. This number stream is saved to a storage de ...
*
Sound recording and reproduction
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording te ...
*
VCR
A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other source on a removable, magnetic tape videocassette, and can play back the recording. ...
*
Videotape
Videotape is magnetic tape used for storing video and usually sound in addition. Information stored can be in the form of either an analog or digital signal. Videotape is used in both video tape recorders (VTRs) and, more commonly, videocassett ...
*
Video head cleaner
A tape head cleaner is a substance or device used for cleaning the Recording head, record and playback heads of a magnetic tape drive found in Video tape, video or Audio tape, audio tape machines such as Compact_Cassette#Cassette_players_and_recor ...
*
VTR
A video tape recorder (VTR) is a tape recorder designed to record and playback video and audio material from magnetic tape. The early VTRs were open-reel devices that record on individual reels of 2-inch-wide (5.08 cm) tape. They were us ...
External links
Diagrams and explanationsof recording heads and the tape recording process.
deconstructed.
showing the head assemblies.
Photoof an early recording head as part of a wire recorder.
Recording
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