초록 ▼

An electronically controlled automatic faucet has a pulsed infrared beam intersecting the water stream discharged by the faucet. Infrared signals reflected from the water stream are thus detected in addition to any signals reflected from a user\s hand(s). A reasonable approximation of the signal rec

An electronically controlled automatic faucet has a pulsed infrared beam intersecting the water stream discharged by the faucet. Infrared signals reflected from the water stream are thus detected in addition to any signals reflected from a user\s hand(s). A reasonable approximation of the signal received from the water stream alone is subtracted from the sum of all detected signals whenever water is flowing in order to provide a compensated proximity signal. This compensation method, which may be implemented in hardware or software, prevents a shift in the sensor\s sensitivity during periods when water is flowing, and eliminates the possibility that water flow might “lock-on”once initiated. Compensating for water flow improves sensor performance by allowing the infrared detection field to encompass a larger volume of space where a user\s hands might be found. In addition, the same, or similar, hardware can be used to detect a user\s hand motion. The disclosed motion detection method can be used alone, or it can be used as an adjunct to the water stream compensation method, in which case it prevents extended intervals of water flow that could otherwise occur when foreign objects are left in view of the sensor.

대표청구항 ▼

A method of operating a faucet controller comprising an emitter of optical radiation, a detector of optical radiation having as an output an electrical signal corresponding to the intensity of said radiation received, a computer having computer memory associated therewith, and an electrically actuat

A method of operating a faucet controller comprising an emitter of optical radiation, a detector of optical radiation having as an output an electrical signal corresponding to the intensity of said radiation received, a computer having computer memory associated therewith, and an electrically actuated valve controlled by said computer, said method comprising the steps of a) storing, in a first location in said computer memory, a water-offset value equal to said signal corresponding to radiation reflected only from a stream of water from said faucet, b) storing, in a second location in said computer memory, a threshold value, c) forming a first algebraic difference by subtracting said threshold value from said signal output at a first time and opening said valve if said first difference is greater than zero, d) forming a second algebraic difference by subtracting the sum of said threshold value and said water-offset value from said signal at a second time subsequent to said first time, and e) closing said valve if said second difference is less than zero.