A shaft monitoring system includes a rotatable shaft having a target element coupled thereto that rotates along with the shaft. A proximity sensor is located adjacent to the target element. The proximity sensor measures an inductance of the target element based on one or both of a volume of the target element and a distance between the target element and the proximity sensor, and generates a proximity sensor output signal based on the measured inductance. A signal processing system determines at least one of a position of the shaft, a rotational speed of the shaft, and a rotational direction of the shaft based on the proximity sensor output signal.

The invention relates to an apparatus for ascertaining a velocity component of an object that moves relative to the apparatus in a detection region at a measurement distance and that reflects light originating from a light source, the object generating reflected light that emanates from the detection region. To this end, the apparatus comprises an objective, a modulator, a reception optical unit and a light detector, wherein the objective detects the reflected light generated by the object in the detection region and elimages said light on the modulator, wherein the modulator modulates the reflected light into a sequence of light signals, wherein the reception optical unit images the sequence of light signals generated by the modulator on the light detector and wherein the light detector converts the sequence of light signals into a sequence of electronic signals. Further, the apparatus comprises an interface which transmits the sequence of electronic signals generated by the light detector to an evaluation unit.

The invention relates to a system having a coder with a magnetic track that exhibits an alternation of North and South magnetic poles separated by i Archimedean spiral transitions. The invention also includes a rotation sensor able to detect the periodic magnetic field emitted by the coder using several sensitive elements, the sensitive elements being distributed angularly along the magnetic track while forming between at least two sensitive elements an angle α which is designed so that the signals delivered by the elements are in quadrature.

A rotation angle detection device that is capable of detecting an absolute rotation position with a high accuracy without an error. A rotation detection target rotates together an operatable rotation member and has an outer scale and an inner scale. Two rotation detection elements are arranged at opposite positions across the rotation axis in the radial direction so as to respectively irradiate the outer and the inner scales with light beams and output signals corresponding to reflected components. A control unit calculates a rotation angle of the rotation detection target using the signals. The outer and inner scales are so formed that a signal output from one of the two rotation detection elements increases and the signal output from the other decreases when the rotation member is rotated.

A rotary encoder may include a magnetic encoder disc having a plurality of magnetic features added to the disc by additive manufacturing distributed over a surface of the encoder disc, wherein the disc is configured for attachment to the end of a rotatable shaft, or a cylindrical metallic encoding feature having a plurality of magnetic features added to the cylindrical encoder by additive manufacturing distributed over the surface of the cylindrical encoding feature, wherein the encoding feature is capable of attachment to an outer diameter of the rotatable shaft. The encoder additionally includes a magnetic sensor positioned adjacent to the end of the rotatable shaft to detect magnetic signals from the magnetic features on the disc and/or positioned over the surface of the rotatable shaft to detect magnetic signals from the magnetic features on the encoding feature.

A drug delivery device comprising: a housing; a cylindrical member rotatably supported within the housing; and a plurality of sensors; wherein: the outer surface of the cylindrical member is provided with a single track, the track forming an encoder and having a plurality of first track segments and a plurality of second track segments arranged along the length of the track which are respectively capable of inducing first and second responses in the sensors; and in each rotational position of the cylindrical member relative to the housing at least one different first track segment is capable of inducing a first response in at least one said sensor, thereby enabling the rotational position of the cylindrical member relative to the housing to be determined.

A drug delivery device comprising: a housing; a cylindrical member rotatably supported within the housing; and a plurality of sensors; wherein: the outer surface of the cylindrical member is provided with a single track, the track forming an encoder and having a plurality of first track segments and a plurality of second track segments arranged along the length of the track which are respectively capable of inducing first and second responses in the sensors; and in each rotational position of the cylindrical member relative to the housing at least one different first track segment is capable of inducing a first response in at least one said sensor, thereby enabling the rotational position of the cylindrical member relative to the housing to be determined.

A magnetic field sensor includes a back bias magnet to generate a DC magnetic field. First and second magnetic field sensing elements of the magnetic field sensor are disposed proximate to at least one ferromagnetic surface of a ferromagnetic target object. The first and second magnetic field sensing elements generate first and second electronic signals, respectively, in response to first and second sensed magnetic fields corresponding to the DC magnetic field but influenced by the at least one ferromagnetic surface. The magnetic field sensor generates a difference signal that is a difference of amplitudes of the first and second electronic signals. The difference signal is indicative of a rotation measurement of an absolute relative rotation of the ferromagnetic target object and the magnetic field sensor about a rotation axis.

This inductive position sensor is designed to measure the angular position of a shaft or the like and includes a support on which are realized, on the one hand, a primary winding, and on the other hand, at least two secondary windings in phase opposition with respect to each other. Each secondary winding is defined by a set of at least two loops in phase with each other. The secondary windings are connected in series and each arranged symmetrically with respect to a middle line so as to form each time a pattern on either side of this middle line, the two patterns having a separation between them in the area of said middle line. An assembly including such a sensor and a target with two oppositely directed helices.

An inductive position sensor designed to measure the angular position of a shaft or the like and includes a support on which are realized, on the one hand, a primary winding, and on the other hand, at least two secondary windings in phase opposition with respect to each other. Each secondary winding is defined by a set of at least two loops in phase with each other. The secondary windings are connected in series and each arranged symmetrically with respect to a middle line so as to form each time a pattern on either side of this middle line, the two patterns having a separation between them in the area of said middle line. An assembly including such a sensor and a target with two oppositely directed helices.