PASS: Professional Audience Safety System
The most beautiful and unique laser show
effect is audience scanning. To be inside the light, to have
colors and shapes wash over you in time to music - there is no
other experience like it.
Audience scanning made
regulators justifiably want to know that, when audience scanning
shows are performed, the light levels are safe. To accomplish
this, Pangolin developed the Professional Audience Safety System
PASS is a
unique system based almost entirely on analog components. When
used with the proper integration and show production techniques,
PASS can assist in maintaining the safety of
Audience Scanning laser shows.
How to ensure audience
PASS continually monitors the laser power, scanner signals, and
other projector-related parameters. If everything is working safely and correctly, then PASS will
never need to interrupt the light output from the projector.
However, if there is a minor problem with the show programming
such that the beam is traveling too slowly, the beam is scanning
an area that is too small, or the beam stops
scanning altogether, PASS will momentarily interrupt the light
coming from the projector, by manipulating the color and blanking
Once the show
resumes safe operation with the laser beam moving sufficiently
fast so as to not present a hazard, PASS will allow the light to
resume coming out of the projector.
hardware and software does this in a very intelligent way so as to
not destroy the intended visual effect. It is only in the event of
a major problem detected within the projector (or within PASS
itself) that PASS will take drastic action. PASS aggressively and
vigorously protects the audience from system failures.
technology that goes beyond scan-fail
significantly more advanced than simple "scan-fail"
products. It went through ten years of R&D, and two years of U.S.
government scrutiny to determine that it provides true safety.
PASS was also reviewed by ILDA judges in 2007 and received the
first place Fenning Award for Technical Achievement. Then, finally
in July 2010, PASS was granted a US Patent.
All of the
systems within PASS were designed such that there is redundancy.
That is, there are always at least two circuits monitoring any
condition (power supply, light output, scanner dynamics, and
system logic). For maximum
reliability, each of these circuits are implemented
in different ways, thus, making it extraordinarily unlikely that
they would fail in exactly the same way at exactly the
same time. And the output of these circuits are polled, such that
all circuits must agree that there is a safe condition, in order
for PASS to allow light to emanate from the projector.
Due to its
redundant approach, there is no single point of failure that
permits hazardous light levels to reach an audience.
If any parameter is unsafe, or if a monitoring circuit within PASS
fails, it will go into a safe mode where laser light ceases. In
fact, PASS will maintain safety even in the face of five
simultaneous system failures!
Not just for U.S. shows
PASS is not just for the U.S. It is for anyone who needs to prove
to a client, an insurance company, or a government inspector that
an audience scanning show will not exceed user-set safety limits.
undergone intense scrutiny by the laser safety community, and
being the safety system within the first projector to receive a CDRH Variance for
European-style Audience Scanning, thus
allowing Audience Scanning laser shows to be performed in the
United States, we believe that PASS is currently the only credible solution to
ensure the continued success of the laser entertainment industry.
Before PASS is installed
After PASS is installed
Easy to install in any
of two components inside your projector: a credit-card-size
circuit board which inserts into the ILDA signal path, and a light
sensor just before the scanners. A few additional connections are
then made to the scanner position signals and the system power
five trimpot adjustments to customize its response:
at the show location, simply adjust the horizon and beam power
parameters. That's it! PASS works automatically to protect the
property, and additional information regarding use in the United
When performing audience-scanning in the United
States, the responsibility to be in compliance with all CDRH and
FDA regulations falls on the purchaser and or integrator of the
PASS system as well as the person performing the actual laser
Please note, that PASS is just one of the elements needed to
perform audience-scanning legally in the United States. The mere
act of putting PASS inside a laser projector will not instantly
and automatically allow it to be used within the United States for
audience scanning. For that to occur, both the projector and the
show will need a variance, in exactly the same way that both the
projector and show would need a variance if it were not used for
audience scanning. However, of course obtaining a variance for an
audience-scanning projector and even an audience-scanning show
takes quite a bit of time and skill on the part of the variance
An audience-scanning variance application must
describe what PASS does, along with the other projector features
(for example, no doubt
including a lens installed either inside or outside the laser
projector to increase divergence) to help ensure audience
safety. Finally, the audience-scanning variance must include
documentation on how the projector is setup, how measurements are
performed and verified, and how the projector is used at each
event in ways that ensure audience safety. For the most part, an
audience-scanning variance application covers the same things that
a more ordinary variance application covers, but it covers them in
a more rigorous way.
While drafting variances for audience scanning,
and for general knowledge of what PASS does and how it works, some
people have found it handy to refer to the Patents on PASS. The
issued US patent can be found on the USPTO web site, or on Google
Patents. It is called "Laser projector safety monitoring system"
and is covered by US Patent number: 7,756,174. In Europe, the
patent application can be found at the World Intellectual Property
Organization web site. It is called "Laser projector for audience
scanning" and is covered by number: EP20060733773. In Australia,
the issued patent can be on the IP Australia web site. It is
called Laser projector for audience scanning and is covered by
Australia Patent number 2006206400.