LED / Laser driver – TOF ECO System

LED / Laser driver

Illumination power decrease at the beginning of an illumination cycle
Illumination power decrease at the beginning of an illumination cycle
Illumination power varies over all four DCSs
Illumination power varies over all four DCSs

A stable illumination is key for good measurement accuracy and low distance noise. The figures show unstable illumination power conditions. It’s obvious that no reliable distance measurements are possible. For example, if the illumination power varies during a DCS burst and from DCS burst to DCS burst, the distance measurement gets wrong. In addition it’s more temperature dependent, more object reflectivity dependent, and noisier. Thus, make sure, all four DCS are acquired with exactly the same intensity and modulation duty cycle.

Rules of thumb:

  • Make sure, the supply voltage for the illumination is stable during the acquisition
  • Make sure, the power dissipation is under control
  • Make sure, the rise and fall time is not temperature dependent