Patent ID: 7278624

Claim:
An automatic water supply system, comprising: an emitter configured to emit light having a first polarization toward an object; 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; 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; 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; wherein the polarizer includes a polarizing beam splitter; wherein the detector includes a beam detector; wherein the polarizing beam splitter has opposing first and second end walls; wherein the polarizing beam splitter has opposing first and second sidewalls; wherein 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; wherein the beam generator faces the first end wall; wherein the beam detector faces the second sidewall; and an opaque member covering the first sidewall.