Capacitive sensing for washroom fixture

• US 9,328,490 B2
• Filed: 02/21/2013
• Issued: 05/03/2016
• Est. Priority Date: 10/24/2006
• Status: Active Grant

• Current Assignee: Bradley Fixtures Corporation (Bradley Corporation)
• Original Assignee: Bradley Fixtures Corporation (Bradley Corporation)
• Inventors: Bayley, Graeme S., Kreitzer, Kenny, Kogler, Nathaniel J., Reckamp, Steven R., Guzzardo, Nick B.
• Primary Examiner(s): Hall, Arthur O
• Assistant Examiner(s): Lee, Chee-Chong
• Application Number:
  US13/773,260
• Publication Number:
  US 20130219614A1
• Time in Patent Office: 1,167 Days
• Field of Search: 462/3, 4DI/G 3, 431/3, 430/2, 430/4, 430/5, 324/663, 324/358, 324/444, 324/448, 324/347, 324/367, 324/519, 324/686, 324/671, 251/129.03, 251/129.04, 251/129.06, 137/801, 335/229
• US Class Current: 1/1
• CPC Class Codes: E03C 1/057 touchless, i.e. using sensors

Abstract

A capacitive sensing system and method for a hand washing lavatory system is disclosed. The lavatory system comprises a receptacle defining a hand washing area, a fixture configured to deliver water to the receptacle, and a capacitive sensing system configured to detect the presence of a user and actuate the fixture. The capacitive sensing system comprises a first sense electrode coupled to the receptacle and configured to measure a first capacitive value, a second sense electrode coupled to the receptacle spaced apart from the first sense electrode and configured to measure a second capacitive value, and a circuit configured to control operation of the fixture in response to a change in the first capacitive value relative to the second capacitive value.

Claims

1. A hand-washing lavatory system comprising:

a receptacle defining a hand washing area;

a fixture that delivers water to the hand washing area;

a first sense electrode coupled to the receptacle that measures a first capacitive value;

a second sense electrode coupled to the receptacle spaced apart from the first sense electrode that measures a second capacitive value; and

a circuit that;

calculates one or more difference values based on a difference between the first capacitive value and the second capacitive value;

compares the calculated one or more difference values to one or more previously recorded difference values; and

activates the fixture in response to determining

one or more rates of change of the calculated one or more difference values from at least one of the one or more previously recorded difference values matches a pattern of changes in the calculated one or more difference values.

2. The hand-washing lavatory system of claim 1 wherein the circuit comprises a sensing control and detection circuit configured to control the sensing and detection operation and provide an output signal that actuates the fixture.

3. The hand-washing lavatory system of claim 2 further comprising a power management and valve actuation circuit configured to manage the power supply and to actuate a valve between an open position and a closed position.

4. The hand-washing lavatory system of claim 3 further comprising photovoltaic cells configured to provide at least a portion of the power used to operate the circuits and valve.

5. The hand-washing lavatory system of claim 1 wherein the first sensor electrode is located below the wash area.

6. The hand-washing lavatory system of claim 5 wherein the second sensor electrode is located below the wash area.

7. The hand-washing lavatory system of claim 1 wherein the first sensor electrode is U-shaped.

8. The hand-washing lavatory system of claim 7 wherein the second sensor electrode is located at least partially within the U-shape.

9. The hand-washing lavatory system of claim 1 wherein the first sensor electrode is L-shaped and the second sensor electrode is located at least partially within the L-shape.

10. The hand-washing lavatory system of claim 1 wherein the first sensor electrode is located above the hand washing area and the second electrode is located below the hand washing area.

11. The hand-washing lavatory system of claim 1 wherein the first sensor electrode and the second sensor electrode are both located above the hand washing area.

12. The hand-washing lavatory system of claim 1 wherein at least one of the first sensor electrode and the second sensor electrode are integrated with at least one of the fixture, a drain, or combinations thereof.

13. The hand-washing lavatory system of claim 1 wherein the first sensor electrode and the second sensor electrode are at least partially encapsulated with the receptacle.

14. A hand-washing lavatory station comprising:

a deck having one or more receptacles providing one or more hand washing areas, and a sink line defining the top of the one or more receptacles;

at least one fixture located at least partially above the sink line that delivers water to one or more of the hand washing areas;

a first sense electrode integrated with the deck and located below the sink line, the first sense electrode measuring a first capacitive value in a first hand washing area of the one or more hand washing areas;

a second sense electrode integrated with the deck and located adjacent to the first electrode and below the sink line, the second sense electrode measuring a second capacitive value in the first hand washing area;

a valve movable between an open position wherein water is permitted to flow through the fixture and a closed position wherein water is prevented from flowing through the fixture;

a circuit coupled to the first sense electrode, the second sense electrode, and the valve, that moves the valve between the open position and the closed position, wherein the circuit;

calculates one or more difference values based on a difference between the first capacitive value and the second capacitive value;

compares the one or more calculated difference values to one or more previously recorded difference values; and

activates the fixture by moving the valve between the open position and the closed position in response to determining

one or more rates of change of the calculated one or more difference values from at least one of the one or more previously recorded difference values matches a pattern of changes in the calculated one or more difference values.

15. The hand-washing lavatory system of claim 14 wherein the first sense electrode at least partially surrounds the second sense electrode.

16. The hand-washing lavatory system of claim 15 wherein the first sense electrode and the second sense electrode are integrally formed as part of a circuit board containing the circuit.

17. The hand-washing lavatory system of claim 16 wherein the first sense electrode is a first conductive area on the circuit board and the second sense electrode is a second conductive area on the circuit board spaced apart from the conductive area of the first sense electrode.