Capacitive angular position sensor
First Claim
1. A sensor assembly for sensing angular position of one object relative to another object, said sensor assembly comprising:
- a transmitter capacitor plate defining a transmitter surface area, said transmitter surface area comprising at least one transmitter electrode;
a receiver capacitor plate disposed in stationary, juxtaposed relation to said transmitter capacitor plate, said receiver capacitor plate defining a receiver surface area facing said transmitter surface area, said receiver surface area generally corresponding in size to said transmitter surface area, said receiver surface area comprising at least two receiver electrodes forming at least one receiver electrode pair;
a rotor composed of a dielectric material disposed within an air gap between the transmitter and receiver surface areas, said rotor comprising three wedge shaped segments having a common rotor center, wherein a first segment subtends substantially 67.5 degrees about said rotor center, a second segment subtends substantially 67.5 degrees about said rotor center and a third segment subtends substantially 45 degrees about said rotor center, and wherein the first segment is separated from the second segment by a vacancy subtending substantially 45 degrees about said rotor center and wherein the third segment is disposed, relative to said rotor center, diametrically opposite said vacancy in substantially equidistant disposition between to said first and second segments, wherein rotation of said rotor relative to said transmitter and receiver capacitor plates varies capacitance between said at least one transmitter electrode and said at least two receiver electrodes; and
means for measuring net charge induced on said at least one receiver electrode pair, wherein the charges indicate the angular position of said rotor relative to said transmitter and receiver capacitor plates.
1 Assignment
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Accused Products
Abstract
A sensor assembly for sensing angular position of one object relative to another object. A capacitor is formed between a transmitter capacitor plate having a pair of transmitter electrodes and a receiver capacitor plate having preferably eight receiver electrodes forming four receiver electrode pairs. A dielectric rotor rotates between the plates, the rotor having first and second segments each subtending 67.5 which are mutually separated by a vacancy subtending 45 degrees, and further having a third segment subtending 45 degrees disposed between the first and second segments diametrically opposite the vacancy. An electrical circuit measures net charge induced on each of the receiver electrode pairs, wherein the charges indicate the angular position of said rotor relative to said transmitter and receiver capacitor plates.
21 Citations
14 Claims
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1. A sensor assembly for sensing angular position of one object relative to another object, said sensor assembly comprising:
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a transmitter capacitor plate defining a transmitter surface area, said transmitter surface area comprising at least one transmitter electrode;
a receiver capacitor plate disposed in stationary, juxtaposed relation to said transmitter capacitor plate, said receiver capacitor plate defining a receiver surface area facing said transmitter surface area, said receiver surface area generally corresponding in size to said transmitter surface area, said receiver surface area comprising at least two receiver electrodes forming at least one receiver electrode pair;
a rotor composed of a dielectric material disposed within an air gap between the transmitter and receiver surface areas, said rotor comprising three wedge shaped segments having a common rotor center, wherein a first segment subtends substantially 67.5 degrees about said rotor center, a second segment subtends substantially 67.5 degrees about said rotor center and a third segment subtends substantially 45 degrees about said rotor center, and wherein the first segment is separated from the second segment by a vacancy subtending substantially 45 degrees about said rotor center and wherein the third segment is disposed, relative to said rotor center, diametrically opposite said vacancy in substantially equidistant disposition between to said first and second segments, wherein rotation of said rotor relative to said transmitter and receiver capacitor plates varies capacitance between said at least one transmitter electrode and said at least two receiver electrodes; and
means for measuring net charge induced on said at least one receiver electrode pair, wherein the charges indicate the angular position of said rotor relative to said transmitter and receiver capacitor plates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A sensor assembly for sensing angular position of one object relative to another object, said sensor assembly comprising:
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a transmitter capacitor plate defining a transmitter surface area, said transmitter surface area comprising a semi-circularly shaped first transmitter electrode and a semi-circularly shaped second transmitter electrode disposed diametrically opposite, with respect to said transmitter plate center, said first transmitter electrode;
a receiver capacitor plate disposed in stationary, juxtaposed relation to said transmitter capacitor plate, said receiver capacitor plate defining a receiver surface area facing said transmitter surface area, said receiver surface area generally corresponding in size to said transmitter surface area, said receiver surface area comprising eight wedge-shaped receiver electrodes, each receiver electrode being connected to a respectively counterpart receiver electrode disposed diametrically opposite thereto with respect to said receiver plate center so as to respectively provide a receiver electrode pairs, whereby said receiver electrodes provide four receiver electrode pairs;
a rotor composed of a dielectric material disposed within an air gap between the transmitter and receiver surface areas, said rotor comprising three wedge shaped segments having a common rotor center, wherein a first segment subtends substantially 67.5 degrees about said rotor center, a second segment subtends substantially 67.5 degrees about said rotor center and a third segment subtends substantially 45 degrees about said rotor center, and wherein the first segment is separated from the second segment by a vacancy subtending substantially 45 degrees about said rotor center and wherein the third segment is disposed, relative to said rotor center, diametrically opposite said vacancy in substantially equidistant disposition between to said first and second segments, wherein rotation of said rotor relative to said transmitter and receiver capacitor plates varies capacitance between said first and second transmitter electrodes and said receiver electrodes; and
means for measuring net charge induced on each said receiver electrode pair, wherein the charges indicate the angular position of said rotor relative to said transmitter and receiver capacitor plates. - View Dependent Claims (11, 12, 13, 14)
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Specification