| 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. |
