MediaLas Spooky blue Bedienungsanleitung Seite 19

c) This criteria requires for a pulse repetition that the exposure of a single impulse has to be reduces by a
-0.25
factor of N .
For N= 32,5 within the exposure duration T ( T= 0,25s, "eyelid reflex") the exposure becomes:
=
H H
pulse repetition single impulse
The irradiance relates to the exposure through the impulse duration. Hence, the irradiance of the pulse
repetition is calculated to:
H
pulse repetiton
=
E
pulse repetition
t
impulse
Taking the circular laser-emitting area into account, the maximal permissible laser power for this third
criterion is expressed in:
= ⋅ =
P E A 136,06
laser Laser
Result c): P = 10,68 mW
laser, max
Hence, the limiting decisive factor is the exposure of a pulse repetition. The maximum permissible
exposure is limited to 10,68mW Laser power, being emitted from the laser projector.
Taking into account that some effects of the laser projector are in continuous motion, the impulse duration
has to be decreased by a factor depending on the speed of the movement. In any case the results for the MPE
is increased, as the impulse duration always increases with effect movement. All calculations are therefore
considered worst theoretical case.
The minimum distance for visitor exposure is calculated at 4m. The divergence of the beam, combined with
an additional light exposure through ambient light makes sure, that an exposure to the eye at a retina diameter
of 7mm is unlikely.
The use of smoke machines is considered to reduce the irradiance by a high amount and the visual
effectiveness of the display with smoke is greatly increased. Also, hazing machines are recommended for an
effective operation.
Spooky Blue
J
− −
0,25 3
⋅ = ⋅ ⋅
N 5 10 32,5
2
m
J
−
⋅ 3
2,094 10
2
m
= =
136,06
−
6
⋅
15,39 10 s
W
−
6 2
⋅ ⋅ =
78,53 10 m 10,68
2
m
J
− −
0,25 3
= ⋅
2,094 10
2
m
W
2
m
mW
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