A sensor device includes a conductive layer. The conductive layer is interposed between a first principal surface of an IC chip and a sensor element and faces the sensor element via a resin-based adhesive layer. The sensor element includes: a moving part including a moving electrode; a fixed part including a fixed electrode forming capacitance between the moving electrode and itself; a first terminal connected to the moving electrode; and a second terminal connected to the fixed electrode. The IC chip includes: a signal processor that processes a detection signal from the second terminal; a first voltage generator that generates a first voltage as an operating voltage for the processor; and a second voltage generator that generates a second voltage corresponding to the sensor element's reference potential applied to the first terminal. The conductive layer is electrically connected to the first terminal.

A motor having a rotor, the rotor including a first metal plate having a first size and a second metal plate having a second size arranged on a first surface associated with the rotor. The first metal plate and the second metal plate are arranged adjacent to each other at a predetermined distance from an axis of rotation of the rotor. The first surface rotates perpendicularly about the axis in response to the rotor being rotated about the axis. A stator includes a third metal plate arranged on a second surface associated with the stator. The third metal plate is arranged on the second surface at the predetermined distance from the axis. The second surface is parallel to the first surface and faces the first surface.

A motor having a rotor, the rotor including a first metal plate having a first size and a second metal plate having a second size arranged on a first surface associated with the rotor. The first metal plate and the second metal plate are arranged adjacent to each other at a predetermined distance from an axis of rotation of the rotor. The first surface rotates perpendicularly about the axis in response to the rotor being rotated about the axis. A stator includes a third metal plate arranged on a second surface associated with the stator. The third metal plate is arranged on the second surface at the predetermined distance from the axis. The second surface is parallel to the first surface and faces the first surface.

Sensor arrangement for measuring a rotation speed of a salient member of a rotatable body comprising a first electrode arrangement providing a first input, a second electrode arrangement providing a second input different from the first input, the first and second electrode arrangements configured so noise in the first and second inputs is substantially the same, and wherein variations in the first and second inputs are caused by rotation of the rotatable body and the salient member past the first and second electrode arrangements, an output arrangement for receiving the first and second inputs, and for providing an output proportional to a difference between the first and second inputs, and a retaining member for retaining one or more of the first and second electrode arrangements and output arrangement, the speed of rotation of the salient member measurable from a variation in the output caused by rotation of that salient member.

Sensor arrangement for measuring a rotation speed of a salient member of a rotatable body comprising a first electrode arrangement providing a first input, a second electrode arrangement providing a second input different from the first input, the first and second electrode arrangements configured so noise in the first and second inputs is substantially the same, and wherein variations in the first and second inputs are caused by rotation of the rotatable body and the salient member past the first and second electrode arrangements, an output arrangement for receiving the first and second inputs, and for providing an output proportional to a difference between the first and second inputs, and a retaining member for retaining one or more of the first and second electrode arrangements and output arrangement, the speed of rotation of the salient member measurable from a variation in the output caused by rotation of that salient member.

A configuration and a method for capacitive sensing of the rotatory motion of a rotary member are described. The configuration has four electrodes located in one plane, an analysis unit connected to the electrodes and an electrically conducting coupling surface, which is located at the rotary member opposite to the electrodes. The electrodes comprise a central excitation electrode, surrounded by the other electrodes. The coupling surface is opposite to the surface of the excitation electrode in each rotary position and covers a part of the surface formed by the remaining electrodes and passes over the surface formed by the remaining electrodes during a rotation of the rotary member. The remaining electrodes are formed by two sensor electrodes and a joint reference electrode, whereby at least the joint reference electrode is designed different than the sensor electrodes.

A configuration and a method for capacitive sensing of the rotatory motion of a rotary member are described. The configuration has four electrodes located in one plane, an analysis unit connected to the electrodes and an electrically conducting coupling surface, which is located at the rotary member opposite to the electrodes. The electrodes comprise a central excitation electrode, surrounded by the other electrodes. The coupling surface is opposite to the surface of the excitation electrode in each rotary position and covers a part of the surface formed by the remaining electrodes and passes over the surface formed by the remaining electrodes during a rotation of the rotary member. The remaining electrodes are formed by two sensor electrodes and a joint reference electrode, whereby at least the joint reference electrode is designed different than the sensor electrodes.

A speed sensor for use in measuring the speed of rotation of a rotationally salient rotating member. The speed sensor comprises an electrode and a sensor circuit. The sensor circuit comprises a constant voltage source for supplying a voltage to the electrode to generate an electric field in a dielectric medium. A current detector detects current flow between the constant voltage source and the electrode due to perturbation of the electric field by passage of at least one salient feature of the rotating member through the electric field as the rotating member rotates. The current detector outputs a first signal modulated at a frequency corresponding to the frequency of perturbation of the electric field. The first signal is amplified to produce an amplified signal modulated at a frequency corresponding to the frequency of perturbation of the electric field.

A speed sensor for use in measuring the speed of rotation of a rotationally salient rotating member. The speed sensor comprises an electrode and a sensor circuit. The sensor circuit comprises a constant voltage source for supplying a voltage to the electrode to generate an electric field in a dielectric medium. A current detector detects current flow between the constant voltage source and the electrode due to perturbation of the electric field by passage of at least one salient feature of the rotating member through the electric field as the rotating member rotates. The current detector outputs a first signal modulated at a frequency corresponding to the frequency of perturbation of the electric field. The first signal is amplified to produce an amplified signal modulated at a frequency corresponding to the frequency of perturbation of the electric field.

In an inertial sensor, an acceleration sensor element section includes a first movable section configured to respond to acceleration applied thereto and a diagnosis electrode configured to displace the first movable section with an electrostatic force according to voltage application from a control circuit section. An angular velocity sensor element section includes a second movable section configured to respond to an angular velocity applied thereto and a driving electrode configured to displace the second movable section with an electrostatic force according to voltage application from the control circuit section. A voltage signal input to the driving electrode and a voltage signal input to the diagnosis electrode are the same voltage signal. The voltage signal input to the diagnosis electrode is a signal for detecting a mechanical failure. Carrier signal for detecting displacement of the first movable section has frequency higher than frequency of signal applied to the diagnosis electrode.