DTV Express Learning Center:
Home Entertainment Defined

All the HDTV and Home Theater Terms You Need

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1080i: High definition signal with 1080 scanning lines and interlaced ("i") scanning. This contains up to six times the detail of conventional TV pictures.

16:9 Aspect ratio screen: This is 33% wider than the standard 4:3 aspect ratio screen. It's closer to the proportions of widescreen movies and perfect for Digital TV broadcasting, anamorphic DVD-Video titles and other state-of-the-art 16:9 programming sources.

2-Tuner Picture-in-Picture: Simultaneously displays two shows, with both TV pictures generated by internal tuners.

3-2 pull-down: A feature of most Digital Television (DTV) displays that preserves the integrity of movie film frames for smoother, more consistent pictures in 480-line progressive scanning (480p). In televisions, it works with all film-originated content, including broadcast TV, cable TV, satellite TV and DVD. (see Progressive Scanning.)

32-Bit surround sound decoding: Far more accurate, for higher fidelity than the conventional, 24-bit decoding.

3D digital comb filter: A circuit that processes composite video signals, stripping the color signal (chrominance) apart from the black-and-white signal (luminance). To maintain picture quality, this filter compares each horizontal scanning line with the lines above and below—and with the corresponding lines on the previous and subsequent video frames. You get higher horizontal resolution, higher vertical resolution and reduced video noise.

4:3 Aspect Ratio: The proportions of a conventional television screen. The 4:3 aspect ratio is squarish compared to the widescreen, 16:9 aspect ratio.

480i: The conventional, Standard Definition television signal. This contains 480 active scanning lines (of a total 525 lines) displayed at 30 frames per second. Interlaced ("i") scanning divides each frame into two fields of 240 lines. Each field lasts for 1/60 second.

480p: Enhanced definition TV signal with 480 active scanning lines, progressive ("p") scanning and a rate of 60 frames per second. Used in both digital television broadcasting and progressive scan DVD players.

5.1-Channel Inputs: For receivers, enables you to connect a multi-channel source, such as a Super Audio Compact Disc player. So you can enjoy high-resolution surround sound for music that's a giant step closer to the original performance. The inputs allow for flexibility now and in the future.

6.1-Channel Inputs: Accommodate the latest sources with 6.1-channel surround sound. The sixth channel drives a Surround-Back speaker.

720p: High Definition TV signal with 720 active scanning lines and progressive ("p") scanning. Used in digital television broadcasting.

A

Ambient Light: Any light in the viewing room created by a source other than the projector or screen.

Analog Television: Today's TV system using magnetic waves to transmit and display pictures and sound.

Anamorphic: A type of lens that "squeezes" a 16:9 widescreen picture into a standard 4:3 image. For proper playback, the image needs to be "unsqueezed" by display on a 16:9 screen or by letterbox presentation (with black bars at the top and bottom) of a 4:3 screen.

Artifact: An unwanted distortion of the video signal, visible on the screen.

Aspect ratio: The proportion of TV screen width to height. Conventional television has an aspect ratio of 4:3. Modern, widescreen television has an aspect ratio of 16:9.

ATSC: Stands for the Advanced Television Standards Committee. An advisory group that produced the table of 18 recommended transmission formats for Digital Television (DTV) broadcasting in the United States.

B

BNC: Used with coaxial cables, this connector receives all R, G, B, H-Sync and V-Sync information, and composite video.

C

Cathode Ray Tube (CRT): The oldest and most common television display technology, the CRT is a sealed glass envelope in which the inside front surface is coated by phosphors. The phosphors glow when excited by an electron beam—the "cathode ray." CRTs are used for both direct-view and projection television.

Center channel: A speaker channel in surround sound systems. The Center channel is crucially important because it creates the illusion that the dialog is coming from the actors on the screen, even for off-center listeners.

Chrominance: The color component of a video signal, abbreviated C. Chrominance is combined with the black-and-white signal (luminance) in composite video connections, but kept apart in S-Video and component connections. For higher quality, the single chrominance signal can also be divided into B-Y and R-Y components in Y/Pb/Pr component connections, or into the primary colors of Red, Green and Blue for R/G/B component connections.

Coaxial digital output: A method of connecting high-quality digital audio from a source component to an A/V receiver.

Color Temperature: A method of measuring the "whiteness" of a light source. Metal halide lamps produce higher temperatures than halogen or incandescent lights.

Component Video connections (Y/Pb/Pr): Component video is the best method for connecting analog video signals. Y/Pb/Pr is ideal for DVD players and compatible satellite receivers. Uses separate connections for luminance (Y), blue color difference (Pb) and red color difference (Pr).

Component Video connections (R/G/B): Component video is the best method for connecting analog video signals. R/G/B is ideal for HDTV receivers and computer signals. Uses separate connections for Red (R), Green (G) and Blue (B). Some RGB Component connections employ 5 cables, known as R/G/B/H/V connections.

Composite Video: A single video signal that combines three video subsignals (luminance, chrominance, and sync). Until the development of S-video and component-video outputs, all video connections in consumer products were composite video. Since picture quality is lost when chrominance and luminance are stripped apart for display, S-Video or Component Video connections produce much higher quality, and are recommended over COmposite Video.

Contrast Ratio: The ratio between white and black. The larger the contrast ratio the greater the ability of a projector or display to show subtle color details and tolerate extraneous room light. There are various methods used to measure contrast; contrast ratio figures should best be used as a guide only.

D

Digital-to-Analog Converter: AKA D/A Converter, DAC. An electronic circuit that converts a series of binary codes (Zeroes and Ones) into a continuous analog voltage.

Digital Signal Processing (DSP): Circuits that shape and enhance a signal when it's still in the digital domain. Audio DSP circuits can perform surround sound decoding, create acoustic environments, adjust the bass and treble with incredible precision and even adjust the volume.

Digital Television (DTV): Television delivered and displayed using computer code (digital technology).

Digital Light Processing (DLP): Developed by Texas Instruments, DLP is a light processing system that utilized hundreds of thousands of tiny spinning mirrors to reflect images. Many feel it offers the most accurate reproduction of color available today.

Dithering: Making digital images appear smoother by adding color or random noise during the digitization process.

Dolby Digital: AKA Dolby Digital 5.1. The Dolby Labs format for digital surround sound providing up to 5.1 channels; used in DVDs, the digital TV (DTV) system, and some laserdiscs; formerly called AC-3 (for Audio Code 3). Dolby Digital produces 5.1 discrete channels of sound for Left, Right, Center, Surround-Left, Surround-Right and Low Frequency Effects (LFE) for a Subwoofer.

Dolby Digital EX: A Dolby surround sound system that includes a "center rear" channel to the 5.1 playback format. This additional rear surround channel provides increased spatiality and realism for audio effects that pan from front to back as well as enhanced localization of surround channels that originate from directly behind the listener. (see Dolby Digital)

Dolby Pro Logic: An audio decoding system that processes stereo audio signals into 4-channel (Pro Logic) or 5.1-channel (Pro Logic II) surround sound. (see Dolby Digital)

Dot Pitch: The distance between pixels on a display device. The closer together the dots are create a higher resolution of a displayed image.

dts (Digital Theater System) decoder: Enables multi-channel digital surround sound that is dynamic, spacious and realistic. Generates 5.1 discrete channels of sound for Left, Right, Center, Surround-Left, Surround-Right and Low Frequency Effects (LFE) for a Subwoofer.

DTV receiver: See HDTV receiver.

Dual Voltage: A dual voltage power supply is designed to operate at both 110-Volt and 220-Volt AC.

DVD-Video: Immensely popular video playback system, for which over 10,000 titles have already been published. Some say that DVD stands for "Digital Versatile Disc." Some say "Digital Video Disc." In fact, the format's inventors could not agree. Officially, DVD doesn't stand for anything.

DVI: DVI, launched in 1999, is a purely digital interface that transmits visual data from a source device to a plasma television, LCD TV, DLP Projection TV, or Projector. The connection is also secured by HDCP (High Definition Copy Protection) technology to protect the signal from piracy. (see HDCP Copy Protection)

E

EGA: AKA Enhanced Graphics Array, EGA is an image which displays 640 pixels by 350 lines with 16 colors from a palette of 64 colors.

Enhanced Definition TV (EDTV): Better digital television transmission with at least 480p, in a 16 x 9 or 4 x 3 display and Dolby digital surround sound.

F

Focal Length: Focal length is the distance between the lens and its focal point. A smaller focal length indicates a wider-angle lens.

G

Ghosting: A shadow or weak secondary image as seen on a monitor or display which is created by multiple path broadcast transmission errors.

H

H Sync: AKA Horizontal synchronization. A marker, which indicates to a computer or video signal that it is the beginning of a line.

HD component video connection: Component video (Y/Pb/Pr) connectors that can carry High Definition video sources and DVD 480p progressive scan output.

HDCP Copy Protection: HDCP (High Definition Content Protection) is a standard that is encoded into the video signal to prevent it from being pirated. If a source device is HDCP coded and is connected to a HDTV display or projector without the proper HDCP decoding mechanism, the picture is relegated to "snow" or in some cases, very low (480P) resolutions of the images. In order to see HDTV with HDCP compliance, both the source and display devices must be equipped with HDCP-enabled connections. (see DVI, HDMI)

High-Definition Television (HDTV): The best digital television, widescreen (16 x 9) display with at least 720 progressive (p) scanning lines or 1080 interlaced (i) lines and Dolby digital surround sound.

HDMI: HDMI (High-Definition Multimedia Interface) is the first industry-supported, uncompressed, all-digital audio/video interface. HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel digital audio. HDMI signals are protected by HDCP copy protection. (see HDCP Copy Protection

"HDTV Ready" TV: Term used by some advertising to indicate an analog TV with the display capability and inputs to be transformed into an HDTV with the addition of an HTDV tuner.

HDTV Monitor: Any monitor (display) with the inputs and capability to become an HDTV with the addition of an HDTV tuner.

HDTV Tuner (also decoder, receiver, set-top box): A standalone device capable of receiving and outputting HDTV signals.

Home Theater: Media and home electronics that deliver the movie theater experience at home. Minimum requirements are a DVD player, a television with a screen of 27 inches diagonal or more and an audio system that features Dolby Digital decoding and 5.1-channel surround sound speakers.

Horizontal Frequency: AKA kHz, the total number of horizontal lines scanned per second in a displayed image.

I

Interlaced Scanning: The opposite of Progressive Scanning. The technology behind the conventional television signal, which shows half of a frame's scanning lines in each 1/60 second. First the odd numbered lines are displayed, then the even-numbered lines.

J

JPEG: AKA Joint Photographic Experts Group. An international group, which is working, on a proposed universal standard for the digital compression and decompression of still images used in computer systems. The JPEG idea reduces image size as much as 65:1 and still maintains image integrity by getting rid of subtle color differences the human eye can not see.

K

Keystone Correction: a projector's ability to correct the distortion (usually of a wide-top, narrow-bottom effect) of a projected image caused by improper projector to screen angle.

L

Letterbox: One technique for accommodating widescreen programming on a standard 4:3 screen. Letterboxing presents the widescreen picture with black bars across the top and bottom. Cinema purists love letterboxing because it preserves the director's original vision. Others are disturbed by a picture that does not fill their 4:3 screen.

Liquid Crystal Display (LCD): A television display type that uses a viscous liquid and a mesh of transistors to turn pixels on and off. LCDs are used in both direct-view and projection television. In both cases, LCDs require a light to generate brightness.

Long Throw Lens: A lens designed for projection from the back of a room. Long throw lenses would be used a projection booth in the back of a theater, or from the back of a large classroom. A long throw lens would have to be 50 to 100 FT back to project a 10FT diagonal image.

Low Frequency Effects (LFE) channel: The "0.1" bass channel of surround sound systems, commonly fed to a subwoofer.

Luminance: The black-and-white component of a video signal, abbreviated Y. Luminance is combined with the color signal (chrominance) in composite video connections, but kept apart in S-Video and component connections.

M

Multi-Channel Super Audio CD playback: The benefits of surround sound come to music. Super Audio CD supports up to 5.1 channels of full-quality sound.

N

Noise: Random, unwanted interference with the signal to which you're trying to watch or listen. In audio, noise takes the form of hiss or static. In video, noise is picture "snow," random flecks or specks of unwanted color.

NTSC: The U.S. standard for color TV broadcasting, adopted in the 1950s. NTSC is now used to refer to other aspects of conventional broadcasting, including the frame rate of 29.97 interlaced frames per second and the television raster of 525 gross scanning lines per frame and 480 active scanning lines. NTSC officially stands for National Television Standards Committee.

O

Optical digital output: A method of connecting high-quality digital audio from a source component to an A/V receiver. Optical outputs use a fiber optic transceiver to convert pulses of electrical voltage into flashes of laser light. At the far end, the light is converted back into voltage pulses.

P

PAL: AKA Phase Alternation by Line. The standard color system used throughout Western Europe, except in France.

Pan & Scan: One technique for accommodating widescreen programming on a standard 4:3 screen. The system selects out a 4:3 portion of the larger picture and presents only that portion. To follow the action in the larger picture, a technician must sometimes shift the point of view left or right, "panning" the frame. Cinema purists hate Pan & Scan because it disrupts the director's original vision. Others appreciate a picture that fills their 4:3 screen.

Pixel: Short for picture element. The smallest element in a displayed image. A color pixel is a combination of red, green and blue sub-pixels. Total pixels are usually expressed in horizontal x vertical dimensions (e.g. 1024 x 768).

Plasma: A flat panel television display type in which plasma gas pixels glow when excited by electrodes.

Poly-Silicon LCD: AKA Poly-Si LCD. A popular LCD technology for the top of the line LCD projectors, which results in increased color saturation, with contrast ratios above 200:1.

Power Zoom: A zoom lens with the zoom in and out controlled by a motor, usually adjusted from the control panel or a remote control. This is as compared to Digital zoom, which does this same function Digitally.

Progressive Scanning: The opposite of Interlaced scanning. Shows each scanning line in sequence, for a more seamless, more film-like image. (see 3-2 pull-down.)

Projection: A display system that projects the image as light onto a screen. Front projectors are located out among the audience and project on a reflective, white screen. Rear projectors are self-contained boxes that project onto a translucent screen.

Q

Quantum Mechanics There just aren't many words in English that start with "Q".

R

RCA connector: The connector used with VCRs and stereos for composite video signals and audio.

Rear Projection: Projecting an image through a translucent screen material for viewing from the opposite side. Used in both Rear Projection TVs and DLP TVs

Resolution: Number of pixels per unit of area, expressed as number of pixels wide by number of pixels high that can be displayed on the screen or monitor. More pixels per unit of area produce a higher resolution.

RF connector: Accommodates a local TV broadcast antenna or cable.

S

Satellite Speaker: A compact speaker that reproduces all of an audio signal except for the deepest octaves of bass. Many home theater speaker systems use satellite speakers for the full-range channels and subwoofers to handle the bass.

SECAM: The French broadcast standard (used in some other international markets) for video and broadcasting. Like PAL, SECAM is also a higher resolution than that of the US, until 2002.

Standard Definition TV (SDTV): Basic digital television transmission that may be displayed with fewer than 480p lines in 16 x 9 or 4 x 3 format.

Stereo Broadcast Reception: Decodes MTS stereo TV broadcasts. Can include dbx noise reduction for better sound.

Subwoofer: A specialized loudspeaker that handles only bass frequencies (typically 200 Hz and below). The subwoofer is ideally suited to reproducing the "0.1" Low Frequency Effects channel of modern surround sound systems. Most subwoofers are also "active," meaning that they include their own power amplifier.

Super Audio CD playback: High-resolution audio that enables you to rediscover your love of music. The highest quality sound source available today, Super Audio CD supports both stereo and multi-channel music reproduction.

Super Fine Pitch™ CRT: Refinement of the Sony FD Trinitron CRT that enables even higher resolution.

S-Video connection: Enables you to connect video equipment to your A/V receiver at high signal quality. S-Video keeps the black-and-white signal (luminance) apart from the color signal (chrominance) to maintain picture quality.

SVGA: AKA Super VGA. Refers to a computer signal that is higher than the standard VGA resolution of 640 pixels by 480 lines with 16 or 256 colors. SVGA graphics cards may output resolutions such as 1024 x 768, 1280 x 1024, 1600 x 1200 pixels or higher, with 16.7 million colors displayed.

T

TFT: AKA Thin Film Transistor. A technology used to make Active Matrix LCD panels wherein each pixel has its own transistor switch.

Throw Distance: Length of the projection beam required for a projector to produce and image of a desired size.

U

Universal Power Supply: See Dual Voltage.

Universal remote control: Simplifies operation by also controlling many brands of TVs, VCRs, DVD players and A/V receivers. (May not be compatible with all brands and models.)

V

V-Sync: AKA Vertical synchronization. A marker in a video signal for the beginning of a frame.

Vertical Resolution: The total number of horizontal lines that can be perceived in the vertical direction of the screen.

VGA: AKA Video Graphics Array. This is the standard interface for the IBM PS/2. It is the only analog graphics card IBM has used (other cards handle digital information) 720 x 400 in the text mode, graphics mode 640 x 480 resolution.

W

Widescreen: Programming and video systems that incorporate an aspect ratio wider than the conventional 4:3 television screen. In video, widescreen means 16:9, which equals a ratio of picture width to height of 1.778:1. Movies can use several widescreen formats, including a ratio of 2.35:1.

X

XGA: Acronym for Extended Graphics Adapter. A standard introduced by IBM that includes VGA as well as resolutions up to 1024 pixels by 768 interlaced lines.

Z

Zoom Lens: A projcetor lens with a variable focal length providing the ability to adjust the size of the image on a screen by adjusting the zoom lens, instead of having to move the projector closer or further. Zoom lens ratio Is the ratio between the smallest and largest image a lens can projector from a fixed distance, e.g. 1.2:1.