1. Safety
PR
RESTRICTED
AREA
RESTRICTED
AREA
Image 1-2
1.4.3 HD for fully enclosed projection systems
HD
Hazard Distance (HD) is the distance mea sured f rom the projection lens at wh ich the intensity or the energy per surface
unit becom es lower than the applicable exposure limit on th e 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 re ar pro jection applications; projecting a beam onto a defuse coated projection screen. As displayed
in image 1-3 two areas should be considered: the restricted enclosed pr ojection area (RA) and the observation are a ( TH ).
RA TH
sw
PD
HDDIFFUSE
sw
RZ
sw
sw
PR
HD
REFLECTION
RESTRICTED
AREA
RESTRICTED
AREA
Image 1-3
RA Restricted Access location (enclosed projection area).
PR Projector.
TH Theater (observation area).
RZ Restriction Zone.
PD Projection Distance.
SW S eparation W idth. Must be minimum 1 meter.
For this type of setup 3 different HD shall be considered:
• HD as discussed in "High Brightness precautions: Haz ard Distance (HD)", page 8 , relevant for intrabeam exposure.
•HD
reflection
: the distance that has to be k ept restrictive related to the reflected light from the re ar projection screen.
•HD
diffuse
: the relevant distance to be considered while obs erving the diffuse surface of the rear pr ojection s creen.
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R5906852 F80 SERIES 21/09/2017