Capacitive proximity sensors
First Claim
1. A capacitive controller the operation of a telephone handset in accordance with the distance from a portion of such handset to the head of a user, said handset including a transmitter and receiver, which comprises:
- a sensing electrode,an insulating layer,a guard electrode spaced away from said sensing by electrode by said insulating layer and shaped to shield said sensing electrode, said sensing electrode, said insulating layer and said guard electrode being incorporated in said handset,means for applying RF signals in unison to said sensing electrode and said guard electrode,means for generating a control signal from changes in the current flowing through said sensing electrode resulting from proximity of handset to the user'"'"'s head, andmeans responsive to said control signal for controlling the operation of said handset.
1 Assignment
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Accused Products
Abstract
Capacitive proximity sensors are disclosed that can be fabricated in different shapes, sizes and materials used in a wide variety of applications. Each such sensor includes a sensing electrode and a guard electrode. The sensor electrode and guard electrode can be parallel conductors separated by an insulating layer, such as a double-sided circuit board shaped to suit the application. One such sensor is transparent for use in conjunction with an optical bar-code scanner. Another sensor is annular in shape for use in conjunction with a telephone transmitter. The sensing electrode and the guard electrode are driven in unison by an RF signal. The proximity of an object to the sensor is observed by detecting changes in the RF current flowing through the sensing electrode caused by the proximity of an object to the sensing electrode.
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Citations
8 Claims
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1. A capacitive controller the operation of a telephone handset in accordance with the distance from a portion of such handset to the head of a user, said handset including a transmitter and receiver, which comprises:
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a sensing electrode, an insulating layer, a guard electrode spaced away from said sensing by electrode by said insulating layer and shaped to shield said sensing electrode, said sensing electrode, said insulating layer and said guard electrode being incorporated in said handset, means for applying RF signals in unison to said sensing electrode and said guard electrode, means for generating a control signal from changes in the current flowing through said sensing electrode resulting from proximity of handset to the user'"'"'s head, and means responsive to said control signal for controlling the operation of said handset. - View Dependent Claims (2, 3, 4, 8)
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5. A capacitive controller for detecting when an object to be scanned is within the range of an optical scanner, said optical scanner having a light source, which comprises:
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a sensing electrode, an insulating layer, a guard electrode spaced away from said sensing electrode by said insulating layer and shaped to shield said sensing electrode, means for applying RF signals in unison to said sensing electrode and said guard electrode means for generating a control signal from changes in the current flowing through said sensing electrode resulting from proximity of an object to said sensing electrode and means responsive to said control signal for energizing said light source when said object is within range of said scanner. - View Dependent Claims (6, 7)
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Specification