| ANSI
lumens |
Brightness is measured in ANSI
(American National Standards Institute) lumens: the brighter
the projector, the higher the ANSI lumen rating. |
| Aspect
Ratio |
Aspect ratio is the ratio of
the width of an image to its height. The most popular aspect
ratios are 4:3 (4 by 3) and 16:9 (widescreen). |
| Component
Video |
Component Video is a method of
delivering 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 analogue
component and Y'Cb'Cr' for digital component. |
| Composite
Video Signal |
The combined picture signal,
including vertical and horizontal blanking and synchronizing
signals. |
| Contrast
Ratio |
The ratio between white and black.
The larger the contrast ratio the greater the ability of a projector
to show subtle colour details and tolerate room light. |
| Digital
Light Processing (DLP) |
A commercial term from Texas
Instruments (TI) otherwise referred to as DMD. It works by the
alignment of thousands of tiny mirrors, lined up in 800 rows
of 600 mirrors each. Each micro mirror is hinged and motorised
with electrostatic energy allowing them to be tilted at incredible
speeds, modulating the light from a lamp so it can be sent through
a lens, on to the screen. |
| DVI |
Digital Visual Interface between
digital devices such as projectors, flat screens, video conferencing
systems and PCs. |
| DVI-I |
A connector that has the capability
of carrying either digital or analog video signals. This connector
can be converted to the common 15-pin VGA connector with a DVI-I
to VGA adapter making the input compatible with standard VGA
cables. |
| DVI-D |
A connector that has the capability
of carrying digital video signals. This connector is very similar
in appearance to the DVI-I connector but lacks the ability to
carry analog video signals. |
| Eco
Mode |
An option that increases lamp
life by lowering lamp power. When this feature is engaged, the
projector's brightness level will be reduced by approximately
20%. |
| Focal
Length |
The distance from the surface
of a lens to its focal point. |
| Keystone
Correction |
This takes a trapezium-shaped
image caused by mounting a projector at an angle, and makes
it into rectangular one for alignment with screen. |
| LCD |
Liquid Crystal Display technology.
It is used in flats screens and projectors to present a digital
image for viewing. |
| Native
Resolution |
Native Resolution refers to the
number of physical pixels in a display device. For example,
an SVGA projector has 800 physical pixels of resolution horizontally
and 600 pixels vertically or 480,000 total pixels. This is the
native resolution of the projector. Projectors are capable of
projecting greater or smaller resolution images into the same
physical resolution through scaling. |
| NTSC |
The United States broadcast standard
for video and broadcasting. Lower resolution than PAL systems
used in most of the world. |
| PC-Less
Presentation |
Projector accepts a standard
PCMCIA memory card and can play back a saved PowerPoint®
presentation without a computer. |
| Progressive
Scan |
A type of display in which all
the horizontal lines of an image are displayed at one time in
a single frame, unlike an Interlaced Scan in which a frame consists
of two separate fields with the first field consisting of odd
horizontal lines and the second field even horizontal lines. |
| Rear
Screen Projection |
Using an opaque screen, the projector
is placed behind the screen, invisible to the audience. It projects
onto the screen and the audience sees it on the other side eliminating
shadows from the presenter. Ideally a projector with a short
throw lens is used to minimise wasted space behind the screen. |
| Resolution |
The amount of pixels that make
up an image - e.g. 640 x 480 means 640 pixel groups across the
image by 480 pixel groups down. The larger the number of pixels
the higher the resolution and the sharper and more detailed
the image is. Common resolutions are VGA, SVGA, XGA, SXGA, UXGA
these represent increasing levels of resolution. The 'W' prefix
(eg. WXGA) refers to the resolution appropriate to displaying
in wide-screen aspect ratio. |
| RGB |
Red, Green, Blue; the normal
type of monitor used with computers. Example of usage: RGB input
or output often referred to as Computer input or output. |
| S-Video |
A video transmission standard
that uses a 4 pin mini-DIN connector to send video information
on two signal wires called luminance (brightness,Y) and chrominance
(colour, C). S-Video is sometimes referred to as Y/C. Unlike
a composite signal found on a phono/RCA connection where the
Y and C information is combined into one signal, S-Video has
its luminance and chrominance separated meaning that a comb
filter (which can reduce the sharpness of the image) is not
needed inside the projector. |
| SVGA |
800 horizontal pixels by 600
vertical pixels giving a total of 480,000 individual pixels
on screen. |
| SXGA |
1,280 horizontal pixels by 1,024
vertical pixels giving a total display resolution of 1,310,720
pixels. |
| Throw
Ratio |
A ratio between projection distance
and width of image. For example, a throw ratio of 1.8:1 means
that the projector must be 18' away from the screen to result
in a 10' wide image. |
| UXGA |
1,600 horizontal pixels by 1,200
vertical pixels giving a total display resolution of 1,920,000
pixels. |
| VGA |
640 horizontal pixels by 480
vertical pixels giving a total display resolution of 307,200
pixels. |
| WiFi |
Wireless Fidelity and is based
on the IEEE 802.11 specifications for wireless local area networks
(WLAN). There are four specifications in the family: 802.11,
802.11a, 802.11b, and 802.11g. All four use the Ethernet protocol. |
| Zoom
Range |
The ratio between the smallest
and largest image size by adjusting only the projector's zoom
lens. |
