A recording head is the physical interface between a recording 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 c ...

. Recording heads are generally classified according to the

physical Physical may refer to: * Physical examination, a regular overall check-up with a doctor * ''Physical'' (Olivia Newton-John album), 1981 ** "Physical" (Olivia Newton-John song) * ''Physical'' (Gabe Gurnsey album) * "Physical" (Alcazar song) (2004) * ...

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 interpret ...

upon their medium. A recording head is often mechanically paired with a playback head, 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 o ...

to coerce a paramagnetic 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 ...

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 magnet ...

. 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 ...

, ferrite, or sendust. 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, ultrav ...

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 t ...

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 ...

on a recording medium, which accepts the

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 in ...

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 emplo ...

. Note that Magneto-optical 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 ...

, 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 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 ...

Photo gallery

Image:D6-VTR-Scanner.jpg , D6 HDTV VTR 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 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 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.

UVW Betacam SP video heads

External links

Diagrams and explanations
of recording heads and the tape recording process.

deconstructed.

showing the head assemblies.
Photo
of an early recording head as part of a wire recorder. Recording {{engineering-stub

Types

Photo gallery

See also

External links