A system for measuring the relative movement between two elements, such as the scale and slide of a hand-held measuring instrument includes the provision of a number of groups of supply electrodes on the slide, each of the electrodes in each group being supplied from a respective one of a multiple number...http://www.google.com.au/patents/US4420754?utm_source=gb-gplus-sharePatent US4420754 - Measuring device for capacitive determination of the relative position of two with respect to one another moveable parts
