# US 2018/0022374 A1 · Steering wheel grip detection device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0022374 A1 - Document ID: US20180022374A1 - Status: Published application - Kind: A1 - Application number: 15/548,998 - Filed: 2016-02-25 - Published: 2018-01-25 - Earliest claimed: 2015-03-13 - Assignees: Panasonic Intellectual Property Management Co., Ltd. - Applicants: Panasonic Intellectual Property Management Co., Ltd. - Inventors: SHINJI FUJIKAWA; YUTA OKAZAKI; HIROSHI NAITOU; TSUYOSHI NISHIO; NOBUHARU KATSUKI - Web page: https://patentgrep.com/patent/US20180022374A1 ## CPC - B62D 1/065: {Steering wheels with heating and ventilating means (heating and ventilation of steering wheel when connected to vehicle HVAC B60H1/00292)} - B60R 16/037: for occupant comfort {, e.g. for automatic adjustment of appliances according to personal settings, e.g. seats, mirrors, steering wheel} - B62D 1/046: {Adaptations on rotatable parts of the steering wheel for accommodation of switches} - H03K 17/962: {Capacitive touch switches} - G01V 3/08: operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices (with electromagnetic waves G01V3/12) - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract A steering wheel grip detection device includes a series circuit including an inductance element, a thermostat incorporated into a steering wheel, and a heater incorporated into the steering wheel; an electrostatic sensor circuit that detects a grip of the steering wheel by means of an electric or electromagnetic field; and a voltage detecting circuit that detects an open/closed state of the thermostat. ## Claims ### Claim 1 A steering wheel grip detection device comprising: a series circuit electrically connected to between a positive electrode and a negative electrode of a power supply and including a first inductance element, a thermostat incorporated into a steering wheel, and a heater incorporated into the steering wheel; and an electrostatic sensor circuit electrically connected to an end of the heater to which the first inductance element is electrically connected, or to a middle of a wiring path of the heater, the electrostatic sensor circuit detecting a contact with the steering wheel by means of an electric or electromagnetic field, wherein the steering wheel grip detection device includes a voltage detecting circuit electrically connected: to between a wiring path of the positive electrode and any one of connecting points between the first inductance element, the thermostat, and the heater; to between a wiring path of the negative electrode and any one of connecting points between the first inductance element, the thermostat, and the heater; to two ends of the first inductance element; to two ends of the heater; or to two ends of the thermostat, wherein output of the voltage detecting circuit is electrically connected to the electrostatic sensor circuit, and wherein the electrostatic sensor circuit corrects output of the electrostatic sensor circuit based on an open or closed state of the thermostat obtained from output of the voltage detecting circuit. ### Claim 2 (depends on 1) The steering wheel grip detection device of claim 1, further comprising a second inductance element electrically connected to an end of the heater opposite to the end to which the first inductance element is connected, wherein the voltage detecting circuit is connected to two ends of one of circuit components including the first inductance element, the thermostat, the heater, and the second inductance element, to two ends of any two of the circuit components directly series-connected, or to two ends of any three of the circuit components directly series-connected. ### Claim 3 (depends on 1) The steering wheel grip detection device of claim 1, wherein a first switch is electrically connected in parallel with the first inductance element. ### Claim 4 (depends on 2) The steering wheel grip detection device of claim 2, wherein a second switch is electrically connected in parallel with the second inductance element. ### Claim 5 (depends on 1) The steering wheel grip detection device of claim 1, further comprising a second switch electrically connected to an end of the heater opposite to the end to which the first inductance element is connected, ### Claim 6 (depends on 1) The steering wheel grip detection device of claim 1, wherein the electrostatic sensor circuit updates a reference value which is output of the electrostatic sensor circuit when a hand is not in contact with the steering wheel. ### Claim 7 (depends on 1) The steering wheel grip detection device of claim 1, wherein the electrostatic sensor circuit corrects output of the electrostatic sensor circuit based on an open or closed state of the thermostat obtained from output of the voltage detecting circuit wherein the electrostatic sensor circuit retains an offset value at a sensor value detected by electrostatic sensor circuit, based on an open/closed state of the thermostat obtained from output of the voltage detecting circuit, and adds the offset value to the sensor value or subtracts the offset value from the sensor value, in response to change of the open/closed state. ### Claim 8 (depends on 1) The steering wheel grip detection device of claim 1, further comprising a current detecting circuit electrically series-connected to a wiring path of the series circuit. ### Claim 9 (depends on 8) The steering wheel grip detection device of claim 8, wherein output of the voltage detecting circuit and output of the current detecting circuit are electrically connected to the electrostatic sensor circuit, and wherein the electrostatic sensor circuit updates a reference value based on an open/closed state of the thermostat obtained from output of the voltage detecting circuit and output of the current detecting circuit, the reference value being output of the electrostatic sensor circuit when a hand is not in contact with the steering wheel. ### Claim 10 (depends on 8) The steering wheel grip detection device of claim 8, wherein output of the voltage detecting circuit and output of the current detecting circuit are electrically connected to the electrostatic sensor circuit, and wherein the electrostatic sensor circuit retains an offset value at a sensor value detected by the electrostatic sensor circuit, based on an open/closed state of the thermostat obtained from output of the voltage detecting circuit and output of the current detecting circuit, and adds the offset value to the sensor value or subtracts the offset value from the sensor value, in response to change of the open/closed state. ### Claim 11 A steering wheel grip detection device comprising: a series circuit electrically connected to between a positive electrode and a negative electrode of a power supply and including a first inductance element, a thermostat incorporated into a steering wheel, and a heater incorporated into the steering wheel; and an electrostatic sensor circuit electrically connected to an end of the heater to which the first inductance element is electrically connected, or to a middle of a wiring path of the heater, the electrostatic sensor circuit detecting a contact with the steering wheel by means of an electric or electromagnetic field, wherein the steering wheel grip detection device includes a current detecting circuit electrically series-connected to a wiring path of the series circuit, wherein output of the current detecting circuit is electrically connected to the electrostatic sensor circuit, and wherein the electrostatic sensor circuit corrects output of the electrostatic sensor circuit based on an open/closed state of the thermostat obtained from output of the current detecting circuit. ### Claim 12 (depends on 11) The steering wheel grip detection device of claim 11, wherein the electrostatic sensor circuit updates a reference value which is output of the electrostatic sensor circuit when a hand is not in contact with the steering wheel. ### Claim 13 (depends on 11) The steering wheel grip detection device of claim 11, wherein the electrostatic sensor circuit corrects output of the electrostatic sensor circuit based on an open or closed state of the thermostat obtained from output of the voltage detecting circuit wherein the electrostatic sensor circuit retains an offset value at a sensor value detected by the electrostatic sensor circuit, based on an open/closed state of the thermostat obtained from output of the current detecting circuit, and adds the offset value to the sensor value or subtracts the offset value from the sensor value, in response to change of the open/closed state. ### Claim 14 (depends on 7) The steering wheel grip detection device of claim 7, wherein the offset value is determined based on an actual measured value of the offset value generated by change of the sensor value due to previous opening and closing of the thermostat. ### Claim 15 (depends on 10) The steering wheel grip detection device of claim 10, wherein the offset value is determined based on an actual measured value of the offset value generated by change of the sensor value due to previous opening and closing of the thermostat. ### Claim 16 (depends on 13) The steering wheel grip detection device of claim 13, wherein the offset value is determined based on an actual measured value of the offset value generated by change of the sensor value due to previous opening and closing of the thermostat.