Proximity sensor with adaptive threshold
First Claim
1. A data input device, comprising:
- a first proximity detector located at a first position on the device;
a second proximity detector located at a second position on the device; and
a processor in communication with the first and second proximity detectors, and configured to recognize an object-near condition only if both the first detector and the second detector detect an object in close proximity.
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Accused Products
Abstract
A proximity sensor measures receptor output with an energy source deactivated. The sensor then measures receptor output with the energy source activated. The measurements with the energy source activated are compared to the measurements with the energy source deactivated to compensate for the effect of ambient conditions. A near condition is recognized if the change between the two groups of measurements exceeds a designated value. To compensate for receptor output that may decrease after reaching a peak value during approach of an object, a near condition can be maintained until the change between the two groups of measurements no longer exceeds a different designated value. Multiple sensors can be used to avoid false near conditions caused by, e.g., placing a device equipped with the sensors next to a stationary object. In one embodiment, a sensor comprises an infrared light emitting diode and a phototransistor.
102 Citations
14 Claims
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1. A data input device, comprising:
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a first proximity detector located at a first position on the device;
a second proximity detector located at a second position on the device; and
a processor in communication with the first and second proximity detectors, and configured to recognize an object-near condition only if both the first detector and the second detector detect an object in close proximity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification