Marked plate for a rotational angle sensor element, an angular sensor element for rotating structural parts, and a process for determining a reference value

An angle sensor element for rotating structural parts, including a marked plate that can be coupled to the rotating structural part and that has many angle marks provided oriented radially to the rotational axis and arranged in the form of a collar arranged concentrically to the rotational axis and with at least one reference mark, a fixed sensor unit for the angle marks, including at least one transmitter of electromagnetic radiation and at least one receiver for the radiation modulated by the marked plate, as well as mechanisms for connection to an evaluation unit, wherein the marked plate has only one track of angle marks, the reference mark is formed by an angle mark that deviates in its modulating properties from remaining angle marks, and only one transmitting and/or receiving window at a time is provided directed at the track of angle marks.

A process for determining a reference value from an analog signal, which is obtained by the modulation of a transmitter signal through many angle marks and at least one reference mark that deviates in the quality of the modulation relative to the angle marks, whereby the modulated signal is received by a receiver and supplied to an evaluation unit and digitalized further if need be, wherein for each angle and reference mark, from an analog peak value of the preceding angle marks, an peak value continuing the trend of peak values is determined and is used in the evaluation unit, changed by a defined value, as a threshold for the presence of the reference value that deviates in its modulation.