Hd For Fully Enclosed Projection Systems - Barco F80 User Manual

Install one or more readily accessible controls to immediately terminate LIP projection light. The power input at
the projector side is considered as a reliable disconnect device. When required to switch off the projector,
disconnect the power cord at the projector side. In case the power input at the projector side is not accessible
(e. g. truss mount), the socket outlet supplying the projector shall be installed nearby the projector and be
easily accessible, or a readily accessible general disconnect device shall be incorporated in the fixed wiring.

1.4.3 HD for fully enclosed projection systems

HD
Hazard Distance (HD) is the distance measured from the projection lens at which the intensity or the
energy per surface unit becomes lower than the applicable exposure limit on the cornea or on the
skin. The light beam is considered (to be) unsafe for exposure if the distance from a person to the
light source is less than the HD.
Restriction Zone (RZ) based on the HD
The projector is also suitable for rear projection applications; projecting a beam onto a defuse coated
projection screen. As displayed in
projection area (RA) and the observation area (TH).
RESTRICTED
AREA
Image 1–3
RA Restricted Access location (enclosed projection area).
PR Projector.
TH Theater (observation area).
For this type of setup 3 different HD shall be considered:
• HD as discussed in "High Brightness precautions: Hazard Distance (HD)", page
exposure.
• HD : the distance that has to be kept restrictive related to the reflected light from the rear projection
reflection
screen.
• HD : the relevant distance to be considered while observing the diffuse surface of the rear projection
diffuse
screen.
As described in "High Brightness precautions: Hazard Distance (HD)", page
restricted zone within the beam areas closer than any HD. In the enclosed projection area the combination of
two restricted zones are relevant: The restricted zone of the projected beam toward the screen; taking into
account 1 meter Separation Width (SW) from the beam onward. Combined with the restricted zone related to
the rear reflection from the screen (HD
The HD distance equals 25% of the difference between the determined HD distance and the projection
reflection
distance to the rear projection screen. To determine the HD distance for the used lens and projector model see
chapter "HD in function of the lens Throw Ratio (TR)", page
HD = 25% (HD – PD)
reflection
Image 1– 3 two areas should be considered: the restricted enclosed
RA
RZ
PR
); also taking into account a 1 meter lateral separation.
reflection
TH
HD
DIFFUSE
PD
HD
REFLECTION
RZ Restriction Zone.
PD Projection Distance.
SW Separation Width. Must be minimum 1 meter.
17, it is mandatory to create a
20.
Safety
17, relevant for intrabeam
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