Capacitive dome switch
First Claim
1. A dome switch comprising:
- a circuit comprising at least one terminal, wherein the at least one terminal is electrically conductive, and wherein no external surface of the at least one terminal is exposed;
a first capacitor;
a second capacitor;
a dome positioned adjacent to the circuit, wherein the dome is associated with each one of the first capacitor and the second capacitor, and wherein a portion of the dome is operative to deflect to decrease a distance between the portion of the dome and the at least one terminal;
a controller electrically connected to the at least one terminal, wherein the controller is operative to measure a first change in capacitance of the first capacitor and a second change in capacitance of the second capacitor, when the portion of the dome deflects.
1 Assignment
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Accused Products
Abstract
This is directed to a dome switch that includes a capacitive sensor. A dome switch can include a dome operative to deform to provide tactile feedback to a user. To provide an electrical instruction to the device, the region underneath the dome can define a free space separating conductive regions forming a capacitor. For example, a tip of the dome, a button placed between the dome and a circuit board, or a user'"'"'s finger can form a first conductor of a capacitor, and a support structure for the dome can include a terminal forming a second conductor completing the capacitor. When the dome deflects, the distance between the conductors can change and provide a measurable capacitance variation, which the device can detect. To protect the dome switch from damage due to contaminants, the terminal can be integrated within a volume of the circuit board such that it is not exposed to the environment of the dome switch. In one implementation, the terminal may not be exposed to air.
64 Citations
20 Claims
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1. A dome switch comprising:
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a circuit comprising at least one terminal, wherein the at least one terminal is electrically conductive, and wherein no external surface of the at least one terminal is exposed; a first capacitor; a second capacitor; a dome positioned adjacent to the circuit, wherein the dome is associated with each one of the first capacitor and the second capacitor, and wherein a portion of the dome is operative to deflect to decrease a distance between the portion of the dome and the at least one terminal; a controller electrically connected to the at least one terminal, wherein the controller is operative to measure a first change in capacitance of the first capacitor and a second change in capacitance of the second capacitor, when the portion of the dome deflects. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for constructing a capacitive dome switch, comprising:
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defining a terminal that is not exposed to an environment of the dome switch; placing a dome over the terminal, wherein the dome is; associated with a first capacitor and a second capacitor of the dome switch; and operative to deflect to change a distance between a tip of the dome and the terminal; and connecting a controller to the terminal, wherein the controller is operative to detect a first change in capacitance of the first capacitor and a second change in capacitance value of the second capacitor, when the dome deflects. - View Dependent Claims (10, 11, 12, 13, 14)
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15. An electronic device, comprising:
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a support structure; at least one conductive terminal, wherein the at least one conductive terminal is coupled to the support structure such that no air external to the support structure comes into contact with the at least one conductive terminal; a first capacitor; a second capacitor; a controller electrically coupled to the at least one conductive terminal a dome placed adjacent to the support structure, wherein the dome is; associated with each one of the first capacitor and the second capacitor; and operative to be at least partially inverted; and a housing enclosing the support structure, the at least one conductive terminal, the controller, and the dome, wherein a tip of the dome is in contact with the housing such that a force applied to the housing is operative to cause the dome to be at least partially inverted, and wherein the controller is operative to detect a first change in capacitance value of the first capacitor and a second change in capacitance value of the second capacitor, when the dome is at least partially inverted. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification