User Guide

Extron • VS 200 SL • User’s ManualExtron • VS 200 SL • User’s Manual
Description and Features
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Features
• Metal enclosure that is half the width of a rack, and 1U high.
• Auto-switchable 100-240 VAC, 50/60 Hz power supply.
• Input capability of RGBS or RGBHV signals.
• Outputs RGBS or RGBHV to the connected projector.
• Digital sync processing, making the movement imperceptible.
• Includes ShiftLock.
VideoShift
VideoShift movement is to the
right, and then down, to the left,
and then up, etc. This is
illustrated to the right. The
distance of the shift or
movement depends upon the
range setting.
The vertical shift is in number of
lines, while the horizontal shift is
in units of time. Approximate
settings are:
Minimum setting:
Vertical shift = 8 scan lines
(4 up and 4 down from center)
Horizontal shift = 0.1 µsec.
Mid-range setting:
Vertical shift = 16 scan lines
Horizontal shift = 0.68 µsec.
Maximum setting:
Vertical shift = 32 scan lines
Horizontal shift = 1.28 µsec.
The actual horizontal distance
depends on the video format.
__ Here are two examples at
maximum range:
SGI – 128 pixels
VGA3 (640 x 480, 31.5 kHz)
– 64 pixels
Specifications
Video input
Number/type .............................. 1 RGBHV, RGBS, RGsB
Connectors ................................ 5 BNC female
Nominal level(s) ......................... Analog ....... 0.3V to 1.25V p-p
Impedance ................................. 75 ohms (all inputs are terminated at 75 ohms)
Horizontal frequency ................. 15 kHz to 150 kHz
Vertical frequency ...................... 40 Hz to 140 Hz
Return loss ................................ -30dB @ 5 MHz
Description of VideoShift
VideoShift
TM
is a video image movement system designed to
extend the life of projection CRTs in large screen projectors and
data monitors. The VideoShift system moves, or shifts, the video
image clockwise around the display screen area. This movement
is so gradual that it takes several minutes for each rotation, and it
is not noticeable by viewers. Shifting the image limits the time
during which bright video information remains in one spot on the
CRT phosphor. Moving the image allows the phosphor to cool
down and recover, thus extending its life.
Screen Savers vs VideoShift
Ordinarily, the life of a CRT or monitor is shortened by allowing
intense or bright information to be displayed in the same location
of the CRT screen for an extended period of time. Images “burn”
into the screen, causing discoloration of the phosphor. Burned
phosphor also has less brightness. This is why computers use
screen saver programs. However, there are applications where a
screen saver would not be practical because the information must
remain on the screen. One example where this is necessary is on
the flight schedule monitors at an airport. The information is
usually stationary white text on a black background. Because
much of the information does not often change, the intense white
text will burn or discolor the display. When the display is turned
off, or the information changes, evidence of old information can
still be seen – usually a dull, brown image.
Applications
A VideoShift system gets the best results when graphic images
are made up of text or lines, because the bright areas are small or
narrow. However, graphic images that have large, bright areas are
less successful because the images are too large to move to a
new area (i.e., when a large, bright area is shifted, it may overlap
the area it previously occupied). However, the VideoShift system
can limit the amount of phosphor burn by distributing the intensity
over a larger area, making it less noticeable.
_ We could think of the phosphor on a screen as being like a field of
grass. Walking across the field occasionally, or in a random
pattern, allows the grass to recover and there is no noticeable path.
However, walking frequently across the same area will wear a path
because the grass can't grow back.
Extron's VideoShift Products
This manual covers the VS 200 SL, one of Extron’s products that
uses VideoShift to prevent burn-in by moving the displayed image
around on the screen. The VS 200 SL model also uses Extron's
ShiftLock™ feature, which allows several ShiftLock devices to be
digitally locked in a master/slave VideoShift system. The master
unit supplies the VideoShift sequence for each slave.
Description and Features
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