Automatic faucet with polarization sensor

• US 20060237674A1
• Filed: 04/25/2005
• Published: 10/26/2006
• Est. Priority Date: 04/25/2005
• Status: Active Grant

• Current Assignee: Masco Corporation
• Original Assignee: Masco Corporation
• Inventors: Iott, Jeffrey, Cohen, Donald K., Disser, James R.
• Granted Patent: US 7,278,624 B2
• Time in Patent Office: Days
• US Class Current: 251/129.40
• CPC Class Codes: E03C 1/057 touchless, i.e. using sensors

Abstract

An automatic faucet system includes a sensor and a controller. The sensor includes an emitter constructed and arranged to emit light having a first polarization toward an object. The sensor further includes a detector configured to detect light reflected from the object having a second polarization that is different from the first polarization. The controller is operatively coupled to the detector. The controller is configured to supply water to a faucet, or other water supply, upon sensing by the detector the light having the second polarization. By sensing in such a manner, the level of false positive readings in the system is reduced. The detector is further configured to determine the location of the object so that the faucet is only activated when the object is in close proximity to the faucet.

Claims

1. An automatic water supply system, comprising:

an emitter configured to emit light having a first polarization toward an object, and

a detector configured to detect reflected light from the object having a second polarization that is different from the first polarization, wherein the detector is configured to sense position of the object; and

a controller operatively coupled to the detector, the controller being constructed and arranged to supply water upon sensing with the detector that the reflected light has the second polarization above a threshold level and that the position of the object is within range.

2. The system of claim 1, wherein the emitter is operable to emit visible light for indicating whether the object is properly positioned.

3. The system of claim 1, wherein the first polarization is oriented perpendicular to the second polarization.

4. The system of claim 1, wherein the emitter includes:

a beam generator operable to generate unpolarized light; and

a polarizer positioned proximal to the beam generator to polarize the unpolarized light to have the first polarization.

5. The system of claim 4, wherein the polarizer includes a polarizing beam splitter.

6. The system of claim 5, wherein the detector includes a beam detector.

7. The system of claim 6, wherein:

the polarizing beam splitter has opposing first and second end walls;

the polarizing beam splitter has opposing first and second sidewalls;

the polarizing beam splitter has a beam splitting surface that separates the first end wall and the first sidewall from the second end wall and the second sidewall;

the beam generator faces the first end wall; and

the beam detector faces the second sidewall.

8. The system of claim 7, further comprising an opaque member covering the first sidewall.

9. The system of claim 7, further comprising a half-wave plate facing the second sidewall.

10. The system of claim 9, further comprising a mirror facing the half-wave plate to reflect light towards the object.

11. The system of claim 9, further comprising a folding prism facing the half-wave plate to reflect light towards the object.

12. The system of claim 6, wherein the beam detector includes a positive-intrinsic photo-diode.

13. The system of claim 4, wherein the detector includes:

a detector polarizer to filter out the light having the first polarization; and

a beam detector positioned proximal to the detector polarizer constructed and arranged to detect the light at the second polarization.

14. The system of claim 13, further comprising an opaque barrier positioned between the emitter and the detector for isolating the emitter from the detector.

15. The system of claim 1, wherein the detector includes:

a polarizer to filter out the light having the first polarization; and

a beam detector positioned proximal to the polarizer constructed and arranged to detect the light at the second polarization.

16. The system of claim 1, wherein the detector includes a position sensing detector to sense the position of the object.

17. The system of claim 16, further comprising:

wherein the emitter includes

a light emitting diode to emit the light,

a lens to focus the light, and

a polarizing film configured to polarize the light to the first polarization;

wherein the detector includes

a polarizing film configured to polarize the reflected light to the second polarization, and

a lens to focus the reflected light onto the position sensing detector;

a valve operatively coupled to the controller for controlling flow of the water.

18. The system of claim 1, further comprising a faucet from which the water is supplied.

19. An automatic water supply system, comprising:

means for detecting a light scattering object;

means for sensing location of the light scattering object; and

means for activating a water supply upon detection that the light scattering object is located in close proximity to the system.

20. The system of claim 19, wherein:

said means for detecting the light scattering object includes a position sensing detector and a polarizer disposed between the position sensing detector and the object;

said means for sensing the location of the light scattering object includes the position sensing detector; and

said means for activating the water supply includes a controller.

21. A method, comprising:

transmitting light having a first polarization toward an object;

detecting reflected light from the object has a second polarization that is different from the first polarization;

determining that the object is located within range based on the reflected light; and

supplying water in response to said detecting the reflected light has the second polarization and said determining that the object is located within the range.

22. The method of claim 21, wherein the first polarization is oriented perpendicular to the second polarization.