Patent ID: 7795584

Claim:
A dispenser for automatically dispensing a product stored in a product supply of said dispenser, said dispenser comprising an electric power supply and an active IR sensing system, said IR sensor system including at least one IR emitter and at least one IR receiver, wherein said IR sensing system is arranged to scan for the presence of a possible user at least at a first scanning rate, and wherein a sensor control system is provided such that said active IR emitter is supplied with a first current which is substantially constant during one or more single scans but which can be altered to a different, second substantially constant current for further scanning, said first and second currents being determined on the basis of a signal strength of the average received IR which is received by said at least one IR receiver during a predetermined number of previous single scans, wherein said dispenser is a paper towel dispenser, and the sensor control system is arranged to detect a maximum threshold value of average received IR, upon which said sensor control system switches a dispensing mode of said dispenser from a user sensing mode to a hanging towel mode.