| A | B |
|---|
| 3-D graphics | Video technology that attempts to create images with the same depths and texture as objects seen in the real world. |
| Accelerated Graphics Port (AGP) | 32/64-bit expansion slot designed by Intel specifically for video that runs at 66 MHz and yields a throughput of at least 254 Mbps. Later version (2x, 4x, 8x) give substantially higher throughput. |
| active matrix | Type of liquid crystal display that replaced the passive matrix technology used in more portable computer displays. |
| anti-aliasing | In computer imaging, blending effect that smoothes sharp contrasts between two regions—e.g., jagged lines or different colors. Reduces jagged edges of text or objects. In voice signal processing, process of removing or smoothing out spurious frequencies from waveforms produced by converting digital signals back to analog. |
| application programming interface (API) | Software definition that describes operating system calls for application software; conventions defining how a service is invoked. |
| aspect ratio | Ratio of width to height of an object. Standard television has a 4:3 aspect ratio. |
| backlight | One of three main components used in LCDs to illuminate an image. |
| bandwidth | Piece of the spectrum occupied by some form of signal, such as television, voice, fax data. Signals require a certain size and location of bandwidth to be transmitted. The higher the bandwidth, the faster the signal transmission, allowing for a more complex signal such as audio or video. Because bandwidth is a limited space, when one user is occupying it, others must wait their turn. Bandwidth is also the capacity of a network to transmit a given amount of data during a given period. |
| cathode ray tube (CRT) | Tube of a monitor in which rays of electrons are beamed onto a phosphorescent screen to produce images. Also a shorthand way to describe a monitor that uses CRT rather than LCD technology. |
| cold cathode fluorescent lamp (CCFL) | Light technology used in LCDs and flatbed scanners. CCFLs use relatively little power for the amount of light they provide. |
| color depth | Term to define a scanner’s ability to produce color, hue, and shade. |
| convergence | Measure of how sharply a single pixel appears on a CRT; a monitor with poor convergence produces images that are not sharply defined. |
| degauss | Procedure used to break up the electromagnetic fields that can build up on the cathode ray tube of a monitor; involves running a current through a wire loop. Most monitors feature a manual degaussing tool. |
| digital visual interface (DVI) | Special video connector designed for digital-to-digital connections; most commonly seen on PC video cards and LCD monitors. Some versions also support analog signals with a special adapter. |
| DirectX | Set of SPIs enabling programs to control multimedia, such as sound, video, and graphics. Used in Windows Vista to draw the Aero desktop. |
| display adapter | Handles all the communication between the CPU and the monitor. Also known as a video card. |
| Display applet | Tool in Windows 2000 and Windows XP used to adjust display stings, including resolution, refresh rate, driver information, and color depth. |
| display power management signaling (DPMS) | Specification that can reduce CRT power consumption by 75 percent by reducing/eliminating video signals during idle periods. |
| dot pitch | Value relating to CRTs, showing the diagonal distance between phosphors measured in millimeters. |
| dual-scan passive matrix | Manufacturing technique for increasing display updates by refreshing two lines at a time. |
| DualView | Microsoft feature enabling Windows to use two or more monitors simultaneously. |
| front-view projector | Shoots the image out the front and counts on you to put a screen in front at the proper distance. |
| graphics processing unit (GPU) | Specialized processor that helps CPU by taking over all of the 3-D rendering duties. |
| high-voltage anode | Component in a CRT monitor that has very high voltages of electricity flowing through it. |
| horizontal refresh rate (HRR) | Amount of time it takes for a CRT to draw one horizontal line of pixels on a display. |
| inverter | Device used to convert DC current into AC. Commonly used with CCFLs in laptops and flatbed scanners. |
| liquid crystal display (LCD) | Type of display commonly used on portable PCs. Also have mostly replaced CRTs as the display of choice for most desktop computer users, due in large part to rapidly falling prices and increasing quality. LCDs use liquid crystals and electricity to produce images on the screen. |
| lumen | Unit of measure for amount of brightness on a projector or other light source. |
| mode | Any single combination of resolution and color depth set for a system. |
| monitor | Screen that displays data from a PC. Can used either a cathode ray tube (CRT) or a liquid crystal display (LCD) to display images. |
| native resolution | Resolution on an LCD monitor that matches the physical pixels and therefore do not have a native resolution. |
| nit | Value used to measure the brightness of an LCD displays. A typical LCD display has a brightness of between 100 and 400 nits. |
| OpenGL | One of two popular APIs used today for video cards. Originally written for UNIX systems but now ported to Windows and Apple systems. |
| passive matrix | Technology for producing colors in LCD monitors by varying voltages across wire matrices to produce red, green, or blue dots. |
| PCI Express (PCIe) | Serialized successor to PCI and AGP, which uses the concept of individual data paths called lanes. May use any number of lanes, although single lanes (x1) and 16 lanes (x16) are the most common on motherboards. |
| persistence | Phosphors used in CRT screens continuing to glow after being struck by electrons, long enough for the human eye to register the glowing effect. Glowing too long makes the images smeary, and too little makes them flicker. |
| Personalization applet | Windows Vista/7 applet with which users can change display settings such as resolution, refresh rate, color depth, and desktop features. |
| phosphors | Electro-fluorescent material that coats the inside face of a cathode ray tube (CRT). After being hit with an electron, it glows for a fraction of a second. |
| pixel | picture element. In computer graphics, smallest element of a display space that can be independently assigned color or intensity |
| polygons | Multi-sided shapes used in 3-D rendering of objects. In computers, video cards draw large numbers of triangles and connect them to form polygons. |
| projector | Device for projecting video images from PCs or other video sources, usually for audience presentations. Available in front and rear view displays. |
| random access memory digital-to-analog converter (RAMDAC) | Circuitry used on video cards that support analog monitors to convert the digital video data to analog. |
| raster line | Horizontal pattern of lines that form an image on the monitor screen. |
| rear-view projector | Projector that shoots an image onto a screen form the rear. Rear-view projectors are usually self-enclosed and very popular for TVs, but are virtually unheard of in the PC world. |
| resolution | Measurement for CRTs and printers expressed in horizontal and vertical dots or pixels. Higher resolutions provide sharper details and thus display better-looking images. |
| response rate | Time it takes for all the sub-pixels on the panel to go from pure black to pure white and back again. |
| shadow mask | CRT screen that allows only the proper electron gun to light the proper phosphors. |
| sidebanding | Second data bus for AGP video cards; enables the video card to send more commands to the Northbridge while receiving other commands at the same time. |
| sprite | Bitmapped graphic such as a BMP file used by early 3-D games to create the 3-D world. |
| sub-pixel | Tiny liquid crystal molecules arranged in rows and columns between polarizing filters used in LCDs. |
| texture | Small picture that is tiled over and over again on walls, floors, and other surfaces to create the 3-D world. |
| thin film transistor (TFT) | Type of LCD screen. |
| throw | Size of the image a projector display at a certain distance from the screen. |
| triad | Group of three phosphors—red, greens, blue—in a CRT. |
| vertical refresh rate (VRR) | The amount of time it takes for a CRT to draw a complete screen. This value is measure in hertz, or cycles per second. Most modern CRTs have a VRR of 60 Hz or better. |
| vertices | Used in the second generation of 3-D rendering, vertices have a defined X, Y, and Z position in a 3-D world. |
| video display | another word for monitor. |
| video graphics array (VGA) | Standard for the video graphics adapter that was built into IBM’s PS/2 computer. It supports 16 colors in a 640 x 480 pixel video display and quickly replaced the older CGA (Color Graphics Adapter) and EGA (Extended Graphics Adapter) standards. |
| viewable image size (VIS) | Measurement of the viewable image that is displayed by a CRT rather than a measurement of the CRT itself. |
