3D Time-of-flight distance measurement with custom - Universität ...

IMAGING TOF RANGE CAMERAS 151
6. Imaging TOF range cameras
Now we introduce the time-of-flight range cameras that we realized with our 1-Tap
lock-in pixel arrays. As mentioned before, we have implemented the demodulation
pixel as a line sensor, carrying 108 pixels and, in a second fabrication run, as a
TOF-imager with 64 by 25 pixels. With these sensors we realized both a 2D TOF
line camera and a 3D TOF imager. Both range cameras are controlled by a fast,
flexible and compact digital sequencer. The sensor chip itself is plugged into a
specially designed driver board, also a very flexible realization that allows the
connection of nine DC levels and 24 AC signals (generated by the sequencer) of
variable amplitude, variable rise and fall time and variable pulse width to any of the
sensor’s pins. The architectural setup of these camera PCBs is roughly described
below. Also we introduce the LEDs that we use for the modulated light source as
well as the corresponding driving electronics.
In the second and third section of this chapter we then present both range camera
realizations, which mainly differ in the LED arrangement of the illumination unit, the
demodulation detector itself and the control-firmware loaded into the sequencer.
Each of these sections starts with an overview of the sensor architecture, then
describes the overall camera system architecture and finally introduces typical
range measurements of non-cooperative scenes that we performed with the
cameras.