Position detection system for detecting position of cage with respect to part of lift system, has sensor, where patterns/symbols are selected and arranged on segments of coding, so that sensor detects patterns or symbols

摘要

The system has a measuring rod on which a coding (a) with coded lines (s1) is applied, and a sensor for contact-less detection of the coding. The coding has a sequence of segments (sg) of same length with different patterns (M) i.e. colors, or symbols or surface characteristics. The coding provides absolute position information about a position along the rod by symbol or pattern combination of the adjacent segments. The patterns/symbols are selected and arranged on the segments, so that the sensor detects the patterns or symbols on the segments in positions of a movable part along the rod.