HADª (Hole Accumulated Diode): A CCD sensor developed by Sony with improved performance in spectral response, vertical smear, and sensitivity. The HAD sensor also introduced electronic shuttering capability to IT type sensors.
HD-MAC: High definition multiplexed-analog component: A defunct proposed European standard for HD transmission to the home.
HDSL: High-bit rate digital subscriber line
HDTV: High definition television
Headend: The electronic equipment located at the start of a cable television system, usually including antennas, earth stations, preamplifiers, frequency converters, demodulators, modulators, and related equipment.
Headstack: An assembly of stationary tape heads.
Helical Recording: The process of moving a magnetic tape around a counter-rotating head drum or scanner to effectively create high writing speeds, recording the signal at an angle on the tape.
Hertz (Hz): Electronic measures of cycles per second: the number of times an electrical event is repeated in a second.
Hetrodyne Recording: The process of reducing the size of the signal's color information to limit the bandwidth requirements. (See color-under).
Hi-Band: The latest standard recording format for Mavica¨ still video that captures resolutions of up to 500 horizontal TV lines. Using new recording heads and process circuitry, the Hi-band format has improved recording resolution from 360 lines in the original ÒstandardÓ format.
High Definition Television: A high-quality television system that has a wider aspect ratio (16:9) and increased number of scanning lines (1100) providing video images of a cinematic quality.
HiPPI: High performance parallel interface.
Horizontal Blanking: The act of cutting off the electron beam at the end of each scanned line for the retrace interval.
Horizontal Blanking Interval: Part of the video signal that contains the pulses that control the transition from the end of one horizontal scan line to the beginning of the next.
Horizontal Resolution: In a television scanning system, the specification of resolution in the horizontal direction, meaning the ability of the system to reproduce closely spaced alternating black-and-white vertical lines of detail across the screen. The number of alternating black -and-white lines is divided by the aspect ratio (usually 3/4) to make comparison between horizontal and vertical resolution easier. This number is usually expressed as TV lines per picture height.
Horizontal Scan Rate: The speed at which the electron beam scans across the screen of a CRT. Horizontal scan rate is measured in kilohertz and is typically between 15 KHz and 40 Khz.
Hue: The shade of a color. (See Wavelength).
Huffman Coding: A specific method of entropy coding used in digital compression of video.
Hygroscopic: The property of magnetic tape that prevents water absorption.
Hyper HADª: A derivative of the HAD sensor that incorporates On Chip Lensing (OCL) and the use of microscopic lenses mounted over each sensing pixel. Hyper HAD sensors with OCL have no perceptible smear and nearly doubled sensitivity.