Patent ID: 6977588

Claim:
A dispenser apparatus for automatically dispensing sheet material without contact between a person and the dispenser, of the type including drive and tension rollers which are rotatably mounted with respect to the dispenser and which form a nip therebetween through which the sheet material is fed, motor drive apparatus in power transmission relationship with the drive roller and power supply apparatus providing electrical current to the motor drive and dispenser electrical components, the improvement comprising: a sensor secured with respect to the dispenser, said sensor having first and second conductors configured to have a capacitance and positioned such that the capacitance is changed by the presence of a user within a detection zone projecting outwardly from the dispenser; a signal detection circuit operatively connected to the sensor for detecting the capacitance change, such circuit having (1) an oscillator having a frequency which is affected by the sensor capacitance, and (2) a differential frequency discriminator which detects changes in the oscillator frequency; and a control circuit which receives the detected frequency change and actuates the motor drive apparatus to dispense the sheet material.