Mobile index detection and continuous marking system - uses detector which moves parallel to index and scans same space

摘要

A method is used for the detection and continuous masking of a mobile index in e.g. measurement apparatus. The detection system employed moves parallel to the index and scans the same space as the index. It is driven by a motor. The displacement of the detection element is controlled from the time when the index has started to move. The stationary position reached by the index is masked when the detection element is stabilised on the equivalent position. Associated apparatus is described in which the control element of the motor driving the detection element is the index itself.