Coded disc for an optoelectronic displacement or angle measuring device

A vehicle steering angle sensor for determining the rotational angle of a steering wheel, the sensor comprising:

• an encoder disk having a coding including a digital code and an analog coded track, the digital code including a plurality of tracks, the analog coded track being a continuous serrated line void of a saltus and defined by a plurality of code segments of non-uniform width arranged in a series one after the other, the encoder disk connected to the steering wheel to move as the steering wheel rotates;
• a sensor arranged in a fixed position relative to the encoder disk, the sensor having a plurality of photoelectric transducers arranged next to one another in a direction transverse to the longitudinal extent of the coding of the encoder disk;
• and
• an illuminator for optically imaging the coding of the encoder disk onto the sensor, wherein the sensor determines the width of the analog coded track at a given position of the encoder disk relative to the sensor as a function of the number of transducers upon which the analog coded track is optically imaged onto at the given position;
• wherein the analog coded track is part of a continuous reference code track which has central symmetry in which the code segments have a code length corresponding to at least the smallest resolution step of the digital coding, wherein the layout of each code segment and the number of transducers of the sensor, onto which such code segment is imaged, are matched to each other such that a movement of the encoder disk along the code length of a code segment is resolved by the sensor into at least two defined steps.

An optoelectronic position measuring device comprising:

• a movable encoder disk having a coding including a digital code and an analog coded track, the digital code including a plurality of tracks, the analog coded track having a plurality of alternate diagonally disposed code segments which are arranged in a series one after the other around the encoder disk;
• a sensor arranged in a fixed position relative to the encoder disk, the sensor having a plurality of photoelectric transducers arranged next to one another in a direction transverse to the longitudinal extent of the coding of the encoder disk;
• and
• an illuminator for optically imaging the coding of the encoder disk onto the sensor, wherein the sensor determines the width of the analog coded track at a given position of the encoder disk relative to the sensor as a function of the number of transducers upon which the analog coded track is optically imaged Onto at the given position.