Tape pack

The structure formed by and comprised solely of tape wound on a hub or spindle; a tape reel consists of a tape pack, the metal, plastic, or glass hub, and flanges. [AMIA]

Tape transport

The mechanics used to guide and move the tape through the recording system and past the magnetic heads of the recorder. The tape transport consists of the tape guides, capstan, rollers, tension controllers, etc. [AMIA]


Abbreviation for Time Base Corrector.

Technology preservation

A digital preservation strategy that involves preserving the complete technical environment, such as software, drivers, operating systems, fonts, passwords, and settings, necessary to facilitate access to archived data as well as its functionality, appearance, and behavior. An alternative approach is emulation. [Getty]


An electro-mechanical machine that converts film image to a video signal. [ScreenSound Australia]


Force, or force per tape width. The force on a tape as it is transported through a recorder. A tape wound on a reel with high tension results in a tape pack with a high interwinding stress. [AMIA]

TFT (Thin Film Transistor)

A technology used to make Active Matrix LCD panels wherein each pixel has its own transistor switch. [Projector People]


An effect related to changes in temperature. The thermal expansion coefficient of a tape refers to its change in length upon a change in the ambient temperature. [AMIA]

Throw distance

Length of the projection beam required for a projector to produce an image of a desired size. [Projector People]

Time base error

A variation in the synchronizing signals on a videotape. When time based errors are large enough, they may cause skewing or flagging distortion of the video picture. [BAVC]

Time code

Electronic indexing method used for editing and timing video programs. Time code denotes hours, minutes, seconds and frames elapsed on videotape. Time code permits very time efficient and accurate editing, and is displayed in a "window dub" tape for logging time code. [BAVC]

Time-base corrector

Electronic device used to correct video signal instability during playback of videotape material. [Abbreviated as TBC]. [ScreenSound Australia]

Track angle

The angle that the track of a helical scan recording makes to the edge of the tape. This corresponds with the scan angle of the helical recorder--the angle that the tape makes to the equatorial plane of the rotating drum head. If the track angle and scan angle do not correspond, mistracking will occur. [AMIA]


The angle and speed at which the tape passes the video heads. Loss of tracking is evidenced by picture breakup or loss of video in segments of the picture. [BAVC]


A device that converts one form of encoded video to another, e.g. to convert NTSC video to PAL. [BAVC]


See migrate.

Trapezoidal error

A change in the angle of a recorded helical scan track. Can result in mistracking. [BAVC]

TSTN (Triple Super Twist Neumatic)

A technology used to make Active Matrix LCD panels wherein each pixel has its own transistor switch. [Projector People]


U-matic, Sony's name for the format, became one of the most successful formats of all time. The cassette mechanism enabled it eventually to be easily used for news acquisition, which until that time had primarily been gathered on 16mm film. As the name suggests, U-type video recorders thread the tape in a 'U' pattern around the head drum. It plays at a tape-transport speed of 3.75 ips and initially had a 240-line resolution but increased as more development was undertaken. [Often referred to as '3/4-inch', there were several variations].[Vidipax]

Universal Preservation Format (UPF)

The Universal Preservation Format initiative advocates a format for the long-term storage of electronically generated media... Working with representatives from standards organizations, hardware and software companies, museums, academic institutions, archives and libraries, this project will produce and publish a document called a Recommended Practice. This document will be submitted to SMPTE, suggesting guidelines for engineers when designing computer applications that involve or interact with digital storage. [UPF]

USB (Universal Serial Bus)

USB provides a serial bus standard for connecting many devices, usually to a computer, but also with other devices such as set-top boxes, game consoles and PDAs. [EAI]


Resolution of a computer generated image. A UXGA projector will be able to display a 1600x1200 image from a computer running in a UXGA video mode. If the computer is not running in a UXGA video mode, typically the projector will resize the image to 1600 x 1200. [Projector People]