Raster - A group of closely-spaced lines whose brightness changes so as to appear to be an image.
CRT - An analog vacuum tube technology that has been the mainstay of conventional TV displays for many years, writing the picture on a phosphor coated screen with an electron beam. It can produce bright pictures of excellent resolution but the size and weight of a unit suitable for the large, wide-screen displays needed for HDTV may be, for some, a disadvantage.
CDTV - Canadian Digital Television, a not-for-profit, government-approved body, with members from all sectors of the TV industry. CDTV is mandated to advise its members, Industry Canada and the CRTC on the roll out of DTV in Canada.
Downconvert - The process which reduces the number of pixels in the scanning format used to represent an image, so that it may be reproduced on a display of lower resolution, such as a conventional television. For example, an HDTV image may be downconverted to an SDTV or NTSC image, but in the conversion significant detail information may be lost.
8-VSB - Acronym for the transmission method used for over-the-air DTV broadcasting in Canada and the USA. Eight discreet amplitude level, "vestigial side-band" broadcast transmission technology. VSB is an analog modulation technique used to reduce the amount of spectrum needed to transmit information through cable TV, or terrestrial broadcasting.
Convergence - An adjustment that must be made occasionally to CRT sets. This adjustment makes the three colors coincide perfectly.
RGB - 1. red-green-blue - 2. a 3-wire standard
DTS - Digital Theatre Sound System. A Dolby proprietary discrete 5.1 channel surround system similar to, but not the same as Dolby Digital AC-3, the DTV standard. DTS is used in cinema presentations and in DVD's.
Interactive Television - TV programming with interactive content and enhancements, blending traditional TV viewing with the interactivity of a personal computer.
Over-the-air Broadcast (OTA) - Also called Terrestrial Broadcast. The delivery of TV and radio signals, using UHF/VHF frequencies, directly to consumer devices. Broadcasts may be either analog or digital.
C-band / Ku-band. - 1. a range of RF spectrum. C-band is app. 4 GHz. Ku-band is app. 12 GHz. 2. Geo-stationary satellites the networks use to acquire and distribute programming to affiliates and cable TV companies. These satellites use C-band and Ku-band frequencies. 3. a consumer service that uses the satellites the networks originally set up for themselves. An 8-foot steerable dish is required. Some channels are free. Others are available by subscription. The digital channel subscription service is called 4DTV.
Convergence - An adjustment that must be made occasionally to CRT sets. This adjustment makes the three colors coincide perfectly.
Fire-wire - (see IEEE 1394)
HD-Ready TV - An HDTV monitor or TV that lacks a digital tuner.
LCOS - (Liquid Crystal On Silicon) - This is another contender to replace CRTs in projection TVs.
MTS - (Multi-channel Television Sound) - This refers to an analog NTSC TV equipped with stereo and SAP (separate audio program) features.
Resolution - The level of resolution directly affects picture quality. The higher the resolution, the more picture detail there is. Many things affect picture quality, including number of bits, pixel count, format, receiver quality, cameras, lenses and lighting used for live or taped programming. Resolution is measured by the number of pixels displayed. One of the high-definition picture formats is composed of 1080 active lines, and each line is composed of 1920 active pixels. Therefore, each frame has over 2 million (1080x1920=2,073,600) color pixels creating the image. By way of contrast, today's typical analog television is roughly equivalent to 480 active lines, with each line holding about 440 pixels. So, each frame has a little over 200,000 color pixels in use creating the image.
Set-top Converter Box - This unit sits on top of the viewer's analog TV, receives the Digital TV signal, converts it to an analog signal, and then sends that signal on to the analog TV.
