CAPACITIVE SWITCH REFERENCE METHOD
First Claim
1. An apparatus, the apparatus being a capacitive switch comprising:
- a capacitive switch sensor, providing a capacitive switch signal;
a capacitive reference sensor, providing a capacitive reference signal; and
an electronic circuit, receiving the capacitive switch signal and the capacitive reference signal,the electronic circuit detecting switch activation by comparing the capacitive switch signal to a threshold signal level,the threshold signal level being adjusted as a function of the capacitive reference signal.
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Accused Products
Abstract
An example capacitive switch apparatus comprises a capacitive switch sensor providing a capacitive switch signal, a capacitive reference sensor providing a capacitive reference signal, and an electronic circuit, receiving the switch and reference signals and detecting switch activation by comparing the switch signal level with a threshold level. The threshold level is adjusted as a function of the reference signal level. The reference signal is obtained, for example during periods of operator proximity to the reference sensor. For a finger-operated switch, the reference signal is obtained when a finger is proximate the reference sensor.
61 Citations
18 Claims
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1. An apparatus, the apparatus being a capacitive switch comprising:
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a capacitive switch sensor, providing a capacitive switch signal; a capacitive reference sensor, providing a capacitive reference signal; and an electronic circuit, receiving the capacitive switch signal and the capacitive reference signal, the electronic circuit detecting switch activation by comparing the capacitive switch signal to a threshold signal level, the threshold signal level being adjusted as a function of the capacitive reference signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A capacitive switch apparatus for a vehicle, comprising:
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a capacitive switch sensor, operable to provide a capacitive switch signal; a capacitive reference sensor, operable to provide a capacitive reference signal; and an electronic circuit, receiving the capacitive switch signal and the capacitive reference signal, the electronic circuit detecting switch activation by comparing the capacitive switch signal with a threshold signal level, the threshold signal level being adjusted as a function of a signal level of the capacitive reference signal, the capacitive reference signal being obtained during periods of vehicle operator hand proximity to the capacitive reference sensor. - View Dependent Claims (13, 14, 15, 16)
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17. A method of detecting an activation of a capacitive switch within a vehicle, the vehicle having a vehicle operator, the method comprising:
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obtaining a reference signal from a capacitive reference sensor when a hand of the vehicle operator is proximate the capacitive reference sensor; using the reference signal to determine a threshold level for switch activation; obtaining a capacitive switch signal from a capacitive switch sensor; comparing the capacitive switch signal with the threshold level to detect activation of the capacitive switch. - View Dependent Claims (18)
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Specification