Proximity sensor
First Claim
1. An immersion sensor assembly comprising:
- a cushion or mattress having an adjustable depth of immersion;
a sensor comprising a conductive material;
a ground comprising a second conductive material electrically isolated from the sensor and surrounding the sensor;
a circuit comprising a reference capacitor, the circuit adapted to send short bursts of electrical current to the sensor and the reference capacitor, the circuit adapted to measure the length of time the burst of current takes to charge the reference capacitor and the circuit adapted to calculate the proximity of a person based upon the time taken to charge the reference capacitor; and
wherein the circuit is adapted to provide an indication when the person is too deeply immersed within the cushion or mattress.
1 Assignment
0 Petitions
Accused Products
Abstract
An immersion sensor for use with a cushion or mattress for determining the relative immersion of a person within the cushion or mattress including a sensor, a ground and a circuit for measuring capacitance. The sensor includes a sheet of conductive material, and the ground includes a second sheet of conductive material. The circuit is adapted to send short bursts of electrical current to the sensor and a capacitor. The circuit is further adapted to measure the length of time the burst of current takes to charge the capacitor. Based upon the measured time, the circuit calculates the proximity of the object based upon the time taken to charge the capacitor. A method that may be implemented with the immersion sensor is also disclosed.
-
Citations
46 Claims
-
1. An immersion sensor assembly comprising:
-
a cushion or mattress having an adjustable depth of immersion; a sensor comprising a conductive material; a ground comprising a second conductive material electrically isolated from the sensor and surrounding the sensor; a circuit comprising a reference capacitor, the circuit adapted to send short bursts of electrical current to the sensor and the reference capacitor, the circuit adapted to measure the length of time the burst of current takes to charge the reference capacitor and the circuit adapted to calculate the proximity of a person based upon the time taken to charge the reference capacitor; and wherein the circuit is adapted to provide an indication when the person is too deeply immersed within the cushion or mattress. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. An immersion sensor for use with a cushion or mattress for measuring the depth of immersion of a person within the cushion or mattress comprising:
-
a sensor layer comprising a conductive material; a ground layer comprising a second conductive material electrically isolated from the sensor and at least partially surrounding the sensor, the ground layer electrically connected to and maintained at a ground electrical potential; a circuit comprising a reference capacitor, the circuit adapted to send short bursts of electrical current to the sensor layer and the reference capacitor, the circuit adapted to measure the length of time the burst of current takes to charge the reference capacitor and the circuit adapted to calculate the proximity of the person based upon the time taken to charge the reference capacitor; and wherein the sensor layer and the ground layer, when the immersion sensor is laid flat, are nominally coplanar.
-
-
16. An immersion sensor assembly comprising:
-
a cushion or mattress having an adjustable depth of immersion; a sensor comprising a sheet of conductive material; a ground layer surrounding the sensor layer; a shield comprising a second sheet of conductive material located adjacent to and having generally the same shape and area as the sensor; a circuit for detecting the capacitive effect of a person upon on the cushion or mattress and providing a relative output for a microcontroller; and wherein the circuit is adapted to provide an indication when the person is too deeply immersed within the cushion or mattress. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25)
-
-
26. A method of determining the proper immersion of a person within a cushion or mattress comprising the steps of:
-
providing a sensor layer below the cushion or mattress comprising a sheet of conductive material; providing a ground layer that is nominally coplanar to the sensor layer and is held at a constant ground potential; using the sensor layer to sense the proximity of the person to the sensor layer to determine the person'"'"'s immersion within the cushion or mattress; and generating a signal when the person is either overimmersed or underimmersed within the cushion or mattress.
-
-
27. A method of determining the proper immersion of a person within a cushion or mattress comprising the steps of:
-
providing a first sensor below the cushion or mattress comprising a sheet of conductive material; providing a ground layer comprising a sheet of conductive material that is nominally coplanar and maintained at a ground potential below the cushion or mattress; sending short bursts of electrical current to the sensor and a capacitor; measuring the length of time the burst of current takes to charge the capacitor; calculating the proximity of the person based upon the time taken to charge the capacitor; and providing an indication when the person is either overimmersed or underimmersed within the cushion or mattress. - View Dependent Claims (28, 29, 30)
-
-
31. A method of determining the proper immersion of a person within a cushion or mattress comprising the steps of:
-
providing a sensor comprising a sheet of conductive material positioned below the cushion or mattress; providing a ground comprising a second sheet of conductive material that surrounds the sensor; sending short bursts of electrical current to the sensor and a capacitor; measuring the length of time the burst of current takes to charge the capacitor; calculating the proximity of the person based upon the time taken to charge the capacitor; and providing an indication when the person is either overimmersed or underimmersed within the cushion or mattress. - View Dependent Claims (32, 33)
-
-
34. An immersion sensor assembly comprising:
-
a cushion or mattress having an adjustable depth of immersion; a sensor comprising a sheet of conductive material; a grounding plane being in the area around the sensor and allowing a capacitance measurement to be made relative to the distance between a person and the sensor; a shield comprising a second sheet of conductive material located adjacent to and having generally the same shape and area as the sensor; a circuit comprising a reference capacitor, the circuit adapted to send short bursts of electrical current to the sensor and the reference capacitor, measure the length of time the burst of current takes to charge the reference capacitor and the circuit adapted to calculate the relative proximity of the person based upon the time taken to charge the reference capacitor, drive the shield to electrically isolate the shield from external capacitance or electromagnetic interference, and provide an indication when the person is too deeply immersed within the cushion or mattress. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43)
-
-
44. An immersion sensor for use with a cushion or mattress for measuring the depth of immersion of a person within the cushion or mattress comprising:
-
a sensor comprising a sheet of conductive material; a ground layer comprising a second sheet of conductive material, the ground layer held at a constant ground electrical potential; a shield comprising a second sheet of conductive material located adjacent to and having generally the same shape and area as the sensor; a circuit for detecting the capacitance effect of an adjacent body and providing a relative output for a microcontroller; and wherein the sensor and the shield, when the immersion sensor is laid flat, are nominally coplanar.
-
-
45. An immersion sensor assembly comprising:
-
an air mattress having an adjustable depth of immersion; a sensor comprising a conductive material; a ground comprising a second conductive material electrically isolated from the sensor and surrounding the sensor; a circuit comprising a reference capacitor, the circuit adapted to send short bursts of electrical current to the sensor and the reference capacitor, the circuit adapted to measure the length of time the burst of current takes to charge the reference capacitor and the circuit adapted to calculate the proximity of a person based upon the time taken to charge the reference capacitor; and wherein the circuit is adapted to provide an indication when the person is too deeply immersed within the air mattress.
-
-
46. A method of determining the proper immersion of a person within a cushion or mattress comprising the steps of:
-
providing a sensor layer below the cushion or mattress comprising a sheet of conductive material; providing a ground layer that surrounds the sensor layer; using the sensor to sense the proximity of the person to the sensor to determine the person'"'"'s immersion within the cushion or mattress; and generating a signal when the person is either overimmersed or underimmersed within the cushion or mattress.
-
Specification