Tradition and Innovation
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OCTOPUS 300 Service Manual
Figure 5-4:
Stimulus LED pulse-width modulation
5.3
Background Intensity Control
The light source for the background illumination consists of a number of white LED’s. During initialization of the perimeter the
background brightness is measured by a photo sensor and controlled by a DAC value. Pulse-width modulation is not used for
background illumination.
5.4
Reference Point
During initialization of the perimeter the stimulus projection unit is centered to the optical system (position x/y = 0/0). The photo
sensor for background illumination calibration is used as reference point.
