SUPPORT CENTER GLOSSARY
ACTIVE MATRIX Computers and projectors have differing abilities to "refresh" the images produced. Active Matrix technology refreshes the images so rapidly that a crisp, uniform image, free from "ghosting" is possible. This is especially noticeable in cursor movements and video images.
ACW See "Advanced Color Wheel"
ADVANCED COLOR WHEEL PLUS's uniquie ACW preserves brightness while allowing for superlatively enhanced color reproduction and astoundingly clear picture quality.
AMBIENT LIGHT All light in a viewing room produced by sources other than the screen.
ANSI LUMENS (Measure of Brightness) This measure of light output of a projected image is one of the faster evolving characteristics in today's projectors. How do you know what's right for you? Consider the room size and ambient light characteristics: Normal-sized meeting rooms (holding 10 or fewer people) in normal working light: 800 Lumens For medium-sized boardrooms (10-20 people) in normal light: 1000-1300 Lumens For big halls and auditoriums in normal light: 1300+ Lumens.
AMORPHOUS TECHNOLOGY This older LCD technology produces a higher contrast but less bright image. The good news is that it's generally the least expensive of the prevailing technologies in final product, and is a simple, reliable system.
ASPECT RATIO The numeric relationship between a screen's height and width. This ratio is often defined by the selected projection medium. Hence, NTSC Video (U.S. television) has an aspect ratio of 3:4.
COLOR We often hear references to 8 bit, 16 bit or 24 bit color. These measurements refer to how many unique colors are used to display the image. The more colors used, the smoother the color gradations will appear. Projector/computer combinations that can support 16 bit displays (65,500+color) will create smoother background gradients and more pleasing photographic or video images than 8-bit (256 color) technology.
COMPONENT VIDEO This is where you have three cables, just for video alone. One for blue, one for red, and one for green. Component Video is a method of delivering better quality video (RGB) in a format that contains all the components of the original image. These components are referred to as luma and chroma and are defined as Y'Pb'Pr' for analog component and Y'Cb'Cr' for digital component. Component video is available on some DVD players and projectors.
COMPOSITE VIDEO This is the standard RCA jack for video. A familiar yellow plug providing an analog video signal. The combined picture signal, including vertical and horizontal blanking and synchronizing signals.
CONTRAST Contrast is what often provides the "snap" we see in projected images. The added sharpness created from greater variations in adjoining pixels can mean the difference between a flat looking image and a crisp one. Compare the contrast ratios between products. The higher the ratio, the greater the contrast.
CRT Cathode Ray Tube. Same technology used in TV and computer monitors.
DLP TECHNOLOGY This light producing projector technology utilizes thousands of micro mirrors on a small chip inside the projector to reflect the different image colors. The image is then sent through a single lens to create the final projected image. Single-chip DLPs and the required color wheel may cause some color-flickering or color break-up. This is more of a problem for television images than for (static) computer presentations.
DUAL COLOR MODE Vivid Mode for color reproduction optimized for digital and moving pictures; Dynamic Mode for optimized brightness. Switch between them easily with one touch of the DCM button on top of the projector or remote.
DVI Digital Visual Interface. DVI is a standard that defines the digital interface between digital devices such as projectors and personal computers. For devices that support DVI, a digital to digital connection can be made that eliminates the conversion to analog and thereby delivers an unblemished image. Specifications on DVI are available at www.ddwg.org.
FOOT LAMBERT A unit of luminance equivalent to 1 lumen per square foot.
IMAGE OFFSET With many of our projectors, the lens is designed to project the image at a slight elevation. This allows you to project onto a vertical surface without having to tilt the projector backwards. If you drew a straight horizontal line from your projector's lens to your wall, the distance between that point and the lowermost point of your image is your offset calculation. Please be sure to take this into consideration when positioning your screen.
HALOGEN BULBS These types of light bulbs produce a warmer image on screen. This bulb technology has been around for some time and is found in many different types of audio-visual projectors. When these bulbs burn out, they go immediately. Have some back-ups ready to go: Lightware Series Halogen projectors come with a spare in the projector. Cost of a halogen lamp is very low: $10 to $20 versus other lamp modules that typically retail for $350!
HDTV Acronym for High Definition Television.
KEYSTONING As an image is projected onto a screen or wall, the angle created can make your projected image appear to be narrower on the bottom than at the top. A few (not most) projectors today have an automatic keystone correction feature to create a uniform image top to bottom. Some projectors can manually adjust this characteristic while others provide only a fixed correction with no further flexibility.
LENTICULAR Screen surface comprised of a geometric embossing pattern. The shape of the pattern affects view\angle performance and reflection of ambient light.
LUMINANCE The measured brightness of a screen, expressed in foot-lamberts.
METAL HALIDE BULBS These types of light bulbs produce a characteristically cooler image on screen. As these bulbs age, they tend to fade slowly over time. When the image on the wall doesn't seem to be as bright as it use to be, it's probably time for a new bulb.
NTSC The most widely accepted video standard that conforms to United States domestic video quality and resolution. This designation in a projector specification indicates that your projector is capable of projecting those images produced from your VHS video tape machine, provided you live in the US.
OPT The "Optimum Projection Technology" designation identifies special products that have been produced with a specific set of user-friendly set-up and usage parameters. It represents an advanced optics design that improves image quality while reducing the projector's size and weight.
POLYSILICON TECHNOLOGY This projector technology typically utilizes 3 independent LCD panels which take light that has been split into primary colors, passes on the colors appropriate to the projected image and reassembles the colors as they're finally projected to the screen. This technology tends to produce a very bright image with richer, more saturated colors. It's typically found in many mid-range projectors and also especially prevalent in high-end products.
PROJECTION AXIS The direction of an imaginary line extending from the center of the projection lens through the screen's center.
RESOLUTION Resolution refers to the number of pixels on the LCD, and describes the clarity of the viewed image. The higher the number of pixels of a projected image, the more visible detail and smoother edges appear on objects like fonts or scanned images. Choosing the right computer or projector resolution will depend on the types of applications you use and the types of images you might project. (See descriptions for VGA, SVGA, XGA, SXGA below)
SVGA Super Video Graphic Array. This 800x600 pixel dimension has 800 horizontal pixels and 600 vertical pixels that define the image on screen. This higher resolution specification for computer and projector displays means that text appears less 'jagged' and more detail is possible in images like spreadsheets and small text and graphics as well as scanned photos.
SXGA Super Extended Graphics Array. A 1280x1024 pixel dimension has 1280 horizontal pixels and 1024 vertical pixels that define the image on screen. This extremely high-resolution specification for computer and projector displays is most frequently required in intricate workstation-design setting where maximum detail is essential.
S-VIDEO is a higher resolution video format supported by many projectors but not widely used by the general public. Your VCR or DVD must support S-Video for you to use this feature, most VCRs do not. PAL and SECAM are video standards generally found in European countries and other places around the world.
VGA Video Graphic Array. 640x480 pixel count means there are 640 horizontal pixels and 480 vertical pixels that define the image on screen. This older specification generally means that text will appear more "jaggy" and bitmap images like photos less uniform.
VIEWING ANGLE The angle from a specified viewing position to the center of the screen. It is usually measured on the horizontal or on the vertical axis. Specified in this guide as optimum screen brightness from screen center to either side.
WEIGHT This may not seem like a consideration until you find yourself with 15 minutes to make a connection from one terminal to another at O'Hare. Then the difference between an 18-lb and a 5-lb LCD Projector can be worth your right arm...sometimes literally! The Ultra-portable designation usually refers to projectors under 10 pounds.XGA Extended Graphics Array. 1024x768 pixels has 1024 horizontal pixels and 768 vertical pixels that define the image on screen. This very high resolution specification for computer and projector displays has eliminated jaggy text and made it possible to read even the smallest detail in spreadsheets and projected software screens.
LENS Some electronic projectors come with zoom
lenses. This feature allows the user to place the projector in a fixed
location and alter the projected image size by simply turning the zoom
lens and then focusing the final image. Small ultra-portable projectors
may not have this feature, as it adds weight and expense. You will need
to determine if physically moving the projector closer or farther from
the screen (for a non-zoom lens product) is a challenge to how you set-up
your presentations and purchase accordingly.