Illumination
(N4x-Series)¶
Risk Group¶
All N4x-series camera models are classified according to DIN EN 62471:2008 and belong to the Exempt Group (no risk). Thus the device is safe for the human eye and does not need any safety labeling.
Exposure Time Limitations¶
The camera comes with diffuse and structured light sources operating at 850 nm wave length (-IR models) or 465 nm wave length (-BL models). All four LED chips are powered by a constant 2 A current during exposure, backed by capacitors.
The LED specification allows a maximum duty cycle of 10 % (e.g. 10 ms at 10 Hz, 5 ms at 20 Hz, etc.). The maximum duration of a single flash pulse is 10 ms. The projector electronics actively monitors the LED stress level and ensures that the LED stays in these limits, cutting off the LED current if necessary.
Note
The internal LED and driver temperature are continuously monitored and the allowable duty cycle will be gradually reduced for LED driver temperatures above 75 °C.
Note
The Capture command will wait until the current LED is ready again for a flash pulse of the currently specified exposure. Thus, software triggering of images might be delayed in order to have constant LED power over the entire exposure time!
Hardware triggering will immediately start the exposure and the LED flash, regardless of the LED stress level. If the LED leaves its safe operating limits during exposure it will be switched off before the end of the exposure time.