Hd For Fully Enclosed Projection Systems - Barco UDM Series Installation Manual

1.5 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 1–4
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", 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", 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 modifying optics", page
HD = 25% (HD – PD)
reflection
The light emitted from the screen within the observation shall never exceed the RG2 exposure limit,
determined at 10 cm. The HD
cd/m² or 15000 LUX.
Image 1– 4 two areas should be considered: the restricted enclosed
RA
RZ
PR
); also taking into account a 1 meter lateral separation.
reflection
18.
can be neglected if the measured light at the screen surface is below 5000
diffuse
TH
HD
DIFFUSE
PD
HD
REFLECTION
RZ Restriction Zone.
PD Projection Distance.
SW Separation Width. Must be minimum 1 meter.
15, relevant for intrabeam
15, it is mandatory to create a
Safety information
R5911438 /08 UDM 17