Are you confused about flat-panel TV terms?
Displays : Glossary
This glossary of common terms related to displa...(WhatIs.com)
Who wouldn’t be, with so many technologies and so many terms to describe them. What’s the difference between LED, LCD and OLED, for example? What does 120hz mean? What’s the soap opera effect? We’ll walk you through in our printable glossary, from 120hz all the way to widescreen.
Are you shopping for a flat-panel TV? See our Flat-panel TV guide for a list of features to look for and a comparison of the various types available.
Flat-panel TV glossary:
60hz – originally, the standard refresh rate for high-definition displays. The refresh rate indicates the number of times a display is repainted per second, in hertz; a 60hz refresh rate indicates that a display is repainted 60 times per second.
120hz – quickly becoming the new standard. A higher refresh rate means a smoother picture and less motion blur.
600hz – a refresh rate sometimes seen specified for plasma displays. It doesn’t identify the refresh rate in the same way that 60hz or 120hz do. Plasma displays sample the incoming signal almost continuously and make any necessary adjustments immediately. A 600hz TV samples the incoming signal 600 times a second.
3-D TV -- a television display technology that enables a three-dimensional effect, so that viewers perceive that an image has depth as well as height and width, similarly to objects in the real world. The 3-D effect is formally known as stereopsis. Typically, specialized glasses are required for the 3-D effect. However, some manufacturers have released auto 3-D (formally known as autostereoscopic) TVs with screen-based technologies that don’t require users to wear 3-D glasses.
3:2 pulldown – another name for telecine or cinema 3:2 pulldown.
ATSC (Advanced Television Systems Committee) is a standards organization that developed standards for digital television (DTV) that specify technologies for the transport, format, compression, and transmission of DTV in the U.S. ATSC standards include HDTV and SDTV.
Aspect ratio – essentially, the ratio of the display’s width to its height. Most flat panel TVs have an aspect ratio of 16:9 for widescreen content, such as movies and high-definition transmissions.
Auto 3-D -- a screen-based 3-D display technology that enables a 3-D effect without requiring viewers to wear special 3-D glasses.
Autostereoscopic display – the formal name for auto 3-D.
Black level – the depth of black shades that a television can display. Deeper black shades improve contrast.
Blu-ray – the standard optical disc format used for 3-D content, such as movies. Blu-ray discs are designed to display high definition video and store large amounts of data. A Blu-ray disc can store 25 gigabytes (GB) per layer. Typically, a disc has two layers but it’s possible for discs to have more.
Burn-in – a phenomenon in which faint, permanent "ghosts" appear on video displays that have displayed fixed images for long periods of time. Burn-in has historically been a problem for plasma displays.
Contrast ratio -- the ratio of the luminance of the brightest white to the darkest black that the display is capable of. A higher contrast ratio means a sharper picture. A ratio of 500:1 is the bare minimum -- the higher the better.
Digital television (DTV) -- the transmission of television signals using digital rather than conventional analog methods. Among other things, DTV enables interactive TV and compatibility with computers and the Internet.
Dot pitch – in effect, the amount of space between adjacent pixels of the same color. The closer pixels of the same color are, the sharper the picture will be. For both plasma and LCD TVs, dot pitch should be approximately 0.25 mm to 0.30 mm.
Frame – a single image in a sequence of images.
Frame rate – the number of frames or images that are displayed per second.
Full HDTV -- a TV display technology with better video quality and sharpness than originally specified for technology, providing an image resolution of 1920 by 1080 pixels. Full HDTV is sometimes referred to as ultra-HD, true HDTV or 1080p.
HD-DVD – a high-capacity optical disc format that competed unsuccessfully with Blu-ray to become the standard disc for high-definition content. HD-DVD was promoted by Toshiba and NEC.
HDTV (high-definition television) – a TV technology that enables picture quality similar to 35 mm. movies and CD-level audio.
Hertz (hz) – a unit of frequency per second. One hertz, for example, is a single cycle per second. Refresh rates are expressed in hertz.
Interactive TV – technology that allows interactivity beyond simply controlling the channel and the volume and so on. Examples include selecting content to view from an onscreen list, playing games, voting, searching for content, scheduling recordings, and shopping from home. Digital TV, which makes interactivity possible, may be built into a television or added through a set-top box.
Internet TV – a delivery model in which content is typically distributed through a website. Competes with IPTV.
IPTV -- the delivery of programming by video stream encoded as a series of IP packets. IPTV is distributed by a service provider and can be free or fee-based and can also deliver either live TV or stored video. Content remains on the service provider's network and only the program the customer selects is sent to the home. When a viewer changes the channel, a new stream is transmitted from the provider's server directly to the viewer.
Judder – a television display artefact that occurs when content recorded on film is shown on a television with a 60Hz refresh rate. Because alternating frames are not repeated in a consistent manner, the picture on the television screen is actually a little jittery.
LED TV -- a type of LCD television that uses LED backlighting instead of the cold cathode fluorescent lights (CCFLs) used in other LCD televisions. The correct name for LED TV is LED-backlight LCD television.
motion interpolation -- a technique used in high definition televisions to display content at a higher refresh rate than that of the source.
OLED TV – a TV display technology based on the characteristics of organic light-emitting diodes (OLED), which enable the best picture quality, in thinnest of all displays. OLED TV is a different technology than LED TV.
Pixel -- the basic unit of programmable color on a TV or computer display. The size of a pixel varies according to the resolution of the display.
Plasma TV – a television display technology in which each pixel on the screen is illuminated by a tiny bit of plasma (charged gas) and the whole encased between two thin sheets of glass. Plasma displays are generally considered higher quality than LCD but the gap is narrowing, in particular between plasma and high-end LED TV.
Refresh rate – the number of times that a display is repainted per second, expressed in hertz (hz). A higher refresh rate means a smoother display, although rates over 120hz have not yielded improvements as great as that of 120hz over 60hz.
Resolution -- the number of pixels contained on a display. Resolution is traditionally expressed as the number of pixels on the horizontal axis and the number on the vertical axis. However, in a flat-panel TV context, a 16:9 aspect ratio is often assumed and only the vertical element expressed, as in 1080p, which identifies 1080 lines of vertical pixels in a progressively scanned (rather than interlaced) display.
Scan converter -- a device that converts video signals into a format that is compatible with a particular type of display, for example translating digital computer video signals so the content can be viewed on an analog television set.
SDTV -- (standard definition television) -- a digital television (DTV) format that provides a picture quality similar to digital versatile disk (DVD). HDTV offers better quality but SDTV requires less bandwidth.
Soap opera effect – a consumer term for a visual effect caused by motion interpolation, a technique used in high definition televisions to display content at a higher refresh rate than that of the source.
Telecine – another name for cinema 3:2 pulldown.
Tru2way -- a software platform that enables set-top box functionality to be integrated into TVs and other viewing devices.
WiFi – local area network (LAN) technology that allows you to connect your TV and other devices to your home network.
Viewing angle – the range within which a display is viewable, typically measured from the center of the screen. 180 degrees is the maximum possible.
Widescreen – describes a display with an aspect ratio of 16:9 (width:height), which is the standard for flat-panel TVs. A 16:9 aspect ratio is optimal for watching movies and HDTV content.
See our Flat-panel TV guide for more information about the various technologies and features to look for in a TV.