# US 9,520,875 B2 · Pliable proximity switch assembly and activation method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,520,875 B2 - Document ID: US9520875B2 - Status: Granted - Kind: B2 - Application number: 14/284,659 - Filed: 2014-05-22 - Published: 2014-09-11 - Granted: 2016-12-13 - Earliest claimed: 2012-04-11 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Mahendra Somasara Dassanayake; Stuart C. Salter; Jeffrey Singer; Michael Istok; Pietro Buttolo - Web page: https://patentgrep.com/patent/US9520875B2 ## CPC - H03K 17/955: using a capacitive detector - H03K 2217/94052: with evaluation of actuation pattern or sequence, e.g. tapping - H03K 2217/960705: Safety of capacitive touch and proximity switches, e.g. increasing reliability, fail-safe - 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) ## Abstract A proximity switch assembly and method for detecting activation of a proximity switch assembly is provided. The assembly includes a plurality of proximity switches each having a proximity sensor providing a sense activation field and control circuitry processing the activation field of each proximity switch to sense activation. A pliable material overlays the proximity sensors. The control circuitry monitors the activation field and determines an activation of a proximity switch based on a signal generated by the sensor in relation to a threshold when a user's finger depresses the pliable material. The pliable material may further include an elevated portion and an air gap between the elevated portion and the sensor. ## Claims ### Claim 1 A proximity switch assembly comprising: a proximity sensor comprising first and second fixed electrodes for generating an activation field; a pliable material overlaying the proximity sensor; and control circuitry monitoring the activation field and determining an activation of a proximity switch based on a signal generated by the sensor in relation to a threshold when a user's finger depresses the pliable material, wherein the control circuitry determines a first stable amplitude of the signal for a time period due to user interaction, determines a subsequent second stable amplitude of the signal for a second time period, and generates an activation output for the proximity switch when the second stable signal exceeds the first stable signal by a known amount. ### Claim 2 (depends on 1) The proximity switch assembly of claim 1 further comprising a substrate, wherein the first and second fixed electrodes of the proximity sensor located on the substrate, and the pliable material overlays the substrate. ### Claim 3 (depends on 1) The proximity switch assembly of claim 1, wherein the pliable material comprises rubber. ### Claim 4 (depends on 1) The proximity switch assembly of claim 1 further comprising an air gap disposed between the pliable material and the proximity sensor, wherein the air gap allows further movement of a user's finger toward the proximity sensor during a depressed motion. ### Claim 5 (depends on 4) The proximity switch assembly of claim 4 further comprising a raised touch surface provided in the pliable material above the air gap. ### Claim 6 (depends on 1) The proximity switch assembly of claim 1, wherein the control circuitry determines a stable amplitude of a signal generated by the sensor for a period time and generates a switch activation output when the stable output exceeds a threshold value. ### Claim 7 (depends on 1) The proximity switch assembly of claim 1, wherein a plurality of proximity switches are installed on a vehicle for use by a passenger in the vehicle. ### Claim 8 (depends on 1) The proximity switch assembly of claim 1, wherein the proximity switch comprises a capacitive switch comprising one or more capacitive sensors. ### Claim 9 (depends on 1) The proximity switch assembly of claim 1, wherein the control circuitry determines the signal as the largest of a plurality of monitored signals associated with a plurality of proximity switches. ### Claim 10 A method of activating a proximity switch comprising: generating an activation field associated with a proximity sensor comprising first and second fixed electrodes; monitoring a signal indicative of the activation field; determining a first stable amplitude when the signal is stable for a minimum time period due to user interaction; determining a subsequent second stable amplitude of the signal for a second time period; and generating an activation output when the second stable amplitude exceeds a first stable amplitude by a known amount indicative of a user depressing on a pliable material overlaying the proximity sensor. ### Claim 11 (depends on 10) The method of claim 10 further comprising the step of determining the signal as the largest of a plurality of monitored signals associated with a plurality of proximity switches. ### Claim 12 (depends on 10) The method of claim 10, wherein the first and second fixed electrodes of the proximity sensor are located on a substrate, and the pliable material overlays the substrate. ### Claim 13 (depends on 10) The method of claim 10, wherein the pliable material comprises rubber. ### Claim 14 (depends on 10) The method of claim 10 further comprising an air gap disposed between the pliable material and the proximity sensor, wherein the air gap allows further movement of a user's finger toward the proximity sensor during a depressed motion. ### Claim 15 (depends on 10) The method of claim 10, wherein a raised touch surface provided in the pliable material above the air gap. ### Claim 16 A proximity switch assembly comprising: a proximity sensor comprising first and second fixed electrodes for generating an activation field; a non-conductive pliable material overlaying the proximity sensor; and control circuitry monitoring the activation field and determining an activation of a proximity switch based on a signal generated by the sensor in relation to a threshold when a user's finger compresses the non-conductive pliable material and moves towards the proximity sensor. ### Claim 17 (depends on 16) The proximity switch assembly of claim 16, wherein the control circuitry determines a first stable amplitude of the signal for a time period due to a user touch interaction, determines a subsequent second stable amplitude of the signal for a second time period during the same user touch interaction, and generates an activation output for a proximity switch when the second stable signal exceeds the first stable signal by a known amount.