Hardware info

Hardware Information

• Laser illuminator

The illuminator uses an 830nm laser diode. There is no modulation - output level is constant. Output power measured at the illuminator output is around 60mW (Using Coherent Lasercheck). The laser is temperature stabilised with a small peltier element mounted between the illuminator and the aluminium mounting plate. This element can both heat and cool the laser to maintain a constant temperature, presumably in order to stabilise the laser's output wavelength. on the sample tested, at room temperature, the laser is being slightly heated.

The depth sensing appears somewhat sensitive to the relative position of the illuminator and sensor. Even a gentle bend of the aluminium plate causes significant disturbance of the depth image.

There is a non-resettable thermal cutout (around 100 deg.C from memory) attatched to the outside of the sensor - this is connected in series with the main 12V supply to the kinect. This positioning suggests that it may be to detect fault conditions causing the laser to heat its enclosure, e.g. if the front window is damaged. The raw laser power is definitely eye-hazardous if not spread out by the pattern-generating optics. Apart from the laser diode, the illuminator is likely to contain a temperature sensor and a photodiode for laser power feeedback - the latter may be integrated in the laser diode can.

• Depth Image sensor

The depth sensor uses a monochrome image sensor. Looking at the signals from the sensor, resolution appears to be 1200x960 pixels at a framerate of 30Hz. The camera's I2C control interface perfoms a one byte transaction every frame - this could be somethng like gain setting or avarage level sensing. The camera has an IR-pass filter at the laser wavelength - tests with various light sources show minimal sensitivity to visible and 950nm sources.