This work concentrates on the development of compact and economical real time distance measurement cameras based on the time-offlight method. Sensors based on so-called demodulation pixels are used for distance measurement from a few centimeters to several meters. Existing time-of-flight camera systems are restricted in operation due to limited distance resolution and a significant susceptibility to interference in relation to high signal dynamics in the scene, strong background light intensity or interference from other camera signals. There thus emerges four important areas of development, for which solutions are presented in this work:
- Enabling multi-camera operation
- Extension of pixel intelligence for capturing highly dynamic scenes
— Active background light suppression at pixel level
- Pixel concepts for measurements with high distance resolution
This elaboration makes a substantial contribution to the extension of the range of applications of real time 3D time-of-flight technology: cameras with pseudo-noise optical modulation can be used in an environment with an almost arbitrary number of cameras running simultaneously. The extension of the dynamic range makes the deployment of the technology possible in demanding environments with objects having strongly varying distance and reflection characteristics, so that outdoor applications become feasible. Drift field pixel structures permit 3D measurements in real time with sub-millimeter resolution. Examples of typical 3D applications are found in the fields of automotive, biometrics, security, surveillance, machine vision, gaming and many more.