PROJECTION
SYSTEMS
SYSTEMS
LGP projection systems utilize closed loop scanning galvos.
Have you ever used an older (analog) electric meter? The kind
that have the needle that moves when you connect a battery? Galvos work just the same except instead of moving a needle they
move a small mirror. The change in the angle of the mirror depends on the amount of voltage applied.
Galvos are devices
that move a small mirror to deflect and scan a laser beam. A laser show projector will typically include two of these galvos.
One galvo will deflect the laser beam up and down (Y-galvo). The second galvo will deflect the laser beam left and right (X-galvo).
The ability to deflect the laser beam up, down, left and right enables the laser show projector to move the beam anywhere on the screen.
Sophisticated
electronics send varied voltage signals to these galvos which then deflect the beam to make complex abstract patterns as well as pictures,
animations and text.
The speed of a closed loop galvo is important to the complexity and quality of the laser imagery that is
projected. In the laser show industry, scanning speed is expressed in "points per second" or "pps."
Scanning speeds
have been standardized by the ILDA (International Laser Display Association). This standardization enables everyone within the
light show industry to properly tune the speed of their projector to match the rest of the industry.
Although faster speeds have
been accomplished, 24 or 30kpps (thousand points per second) is the standard scan speed used within most laser show displays.
When creating a laser show and scanning at the 30kpps standard, the displayed laser show should look exactly the same on other
laser show projectors that scan at the 30kpps standard.
LGP projectors all operate within these scanning standards.