RGB Video
The video output (analog or digital) of most computers. Analog RGB video can have 3, 4,
or 5 wires - one each for red, green, and blue, and either none, one or two for sync. For
three-wire RGB, the green wire usually provides sync. (See TTL Video).
RS-232
A common asynchronous data transmission standard recommended by the Electronics
Industries Association (EIA). Also called serial communication.
RS-422
A less common asynchronous data transmission standard in which balanced differential
voltage is specified. RS-422 is especially suited to long distances.
S-Video
The output from certain video tape players and video equipment. S-Video separates sync
and luminance from color information, typically producing a higher quality display than
composite video.
Scan Frequency
The horizontal or vertical frequency at which images are generated.
Scan Line
One horizontal line on the display.
SECAM
A video output format of some video tape and disc players (used primarily in France).
SECAM (Sequential Couleur á Mémoire) signals are similar in resolution and frequency
to PAL signals. The primary difference between the two standards is in the way color
information is encoded.
Slidebar
A slidebar is a graphical display of an adjustable setting. The numerical setting often rep-
resents a percentage but can be a specific unit such as degrees Kelvin.
Source
The device, such as a computer or VCR, connected to the projector for display. A source
is identified at the projector as , , , or , or as other user-defined num-
bers. A source may have numerous corresponding channels defined and recognized by the
projector. See
Input
.
Source Setup
See
Channel
.
Spot Size
The diameter of the smallest dot that can be generated by a CRT projector. This projector
has a fixed spot (pixel) size.
Sync
This term refers to the part of the video signal that is used to stabilize the picture. Sync
can occur in three forms:
1)
"Composite sync": the horizontal and vertical components are together on
one cable.
2)
"Sync-on-green": the sync is part of the green video.
3)
"Separate sync" or "H.SYNC and V.SYNC": the horizontal and vertical
components of the sync are on two separate cables.
Sync Width
The duration of each sync pulse generated by a computer. The sync width is part of the
blanking time.
TTL Video
A type of RGB video with digital characteristics.
Terminated
A wire connecting a single video source to a display device, such as a projector, must be
terminated by a resistance (usually 75
Ω
for video).
Input1
Input2
Input3
Input4
A-5
GLOSSARY