Method for evaluating the signals of an optoelectronic displacement or angle measuring device and implementation of said method

A method for evaluating a code signal generated by a position measuring system having an encoder with at least one code track and a reference track in which the encoder is interposed between a light source and a light sensor and moves relative to the light source and the light sensor such that the at least one code track and the reference track transmit light from the light source onto the light sensor when the encoder is in a given position relative to the light source, wherein the light sensor generates the code signal as a function of the light transmitted by the at least one code track which is received by transducers of the light sensor, the method comprising the steps of:

• (A) capturing the amplitude of a reference signal generated as a function of the light transmitted by the reference track which is received by transducers of the light sensor;
• (B) evaluating the amplitude of the reference signal;
• (C) adapting at least one measurement parameter that is relevant for evaluating the amplitude of the code signal on the basis of the evaluation of the amplitude of the reference signal in order to compensate the evaluation of the code signal to changing measurement conditions;
• (D) determining brightness of a code track signal generated by light sensor transducers assigned to a code track of the encoder;
• (E) determining brightness of a non-code track signal generated by light sensor transducers assigned to a non-code track section of the encoder;
• (F) determining relative brightness between the code and non-code track signals;
• and
• (G) determining whether the light sensor transducers assigned to the code track of the encoder are exposed to the light source as a function of the relative brightness.