N40/N45 / N30/N35 Rev.2 / N31/N36/N41/N46

Exposure Time Limitations

The camera comes with diffuse and structured light sources operating at 850nm wave length (-IR models) or 465nm wave length (-BL models). All four LED chips are powered by a constant 2A current during exposure, backed by capacitors.

The LED specification allows a maximum duty cycle of 10% (e.g. 10ms at 10Hz, 5ms at 20Hz, etc.). The maximum duration of a single flash pulse is 10ms. 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 degrees celsius.

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.