Most items of the technology described on this website are covered by patents of my own. You will not find an overview over the patent situation for capacitive sensors here.
The shield between sensor and machine is not covered by one of my patents. The patent for this invention has expired many years ago.
The sensors described on this website feature both an economically interesting safety concept and a long range that is yet unheard of.
The first patent covers the safety concept of periodically connecting and disconnecting a test capacity.
One main goal was to develop a sensor that detects a human hand in 40 to 50 centimeters (16 to 20 inches) distance. In electrical terms that means to detect a capacity of well below one picofarad. Covered by further patents are the amplifier designed for this purpose with its negligible input capacity and measures to compensate for changing temperatures as well as decreasing the amplification factor above a certain amplitude. (Patent 2)
The exceptionally far range of these sensors created difficulties one would not find with sensors of a standard range. To cover these issues a method to synchronize multiple sensors was invented and patented. (Patent 3)
Another patent (number 4) is described in A Robot in its Surroundings. This patent has been granted and published June 1st 2017 only one year and five days after the application for it.
My patents complement each other in a way that capacitive sensors built on this technology have a far reach and grant safe protection at higher working speeds of the machine to persons coming close to the machine.