Electronic Towel Dispenser With Additional Power Saving Mode

Abstract

A hands-free towel dispenser includes a housing having an internal volume that may contain at least one roll of towel material. Within the dispenser a dispensing mechanism is in communication with a sensor system which scans for the presence of a user at a first pulse rate and initiates a dispense cycle upon sensing a user. The sensor system is in electrical communication with a control circuit which determines the time that has elapsed from the last dispense cycle and compare the elapsed time with a preset value. If the elapsed time is greater than the preset value, the control circuit configures the sensor system to scan for the presence of a user at a second pulse rate. Upon detecting a user, the control circuit initiates a dispense cycle and sets the sensor system to scan for the presence of a user at the first pulse rate.

What is claimed is: 
     
         1 . A hands-free towel dispenser for dispensing a measured sheet from a roll of web material, the dispenser comprising:
 a housing having an internal volume so as to retain at least one roll of web material therein;   an electronically powered dispensing mechanism contained within the housing for dispensing a measured sheet from the roll of web material in a dispense cycle upon actuation of the dispensing mechanism; and   a sensor system in communication with the dispensing mechanism, the sensor system adapted to scan for the presence of a user at a first pulse rate and to initiate a dispense cycle upon sensing the presence of a user, the sensor system having at least one sensor in electrical communication with a control circuit, wherein the control circuit is configured to determine the time that has elapsed from the last dispense cycle and compare such elapsed time with a preset value, wherein if the elapsed time is greater than the preset value, the control circuit is configured to scan for the presence of a user at a second pulse rate and, upon detecting the presence of a user, the control circuit initiates a dispense cycle and sets the sensor system to scan for the presence of a user at the first pulse rate.   
     
     
         2 . The dispenser of  claim 1 , wherein the sensor system includes an infrared emitter and detector which is capable of emitting at a first pulse rate and a second pulse rate. 
     
     
         3 . The dispenser of  claim 1  wherein the first pulse rate is higher than the second pulse rate. 
     
     
         4 . The dispenser of  claim 1 , wherein the first pulse rate is lower than the second pulse rate. 
     
     
         5 . The dispenser of  claim 1 , wherein the first pulse rate is six times per second. 
     
     
         6 . The dispenser of  claim 1 , wherein the second pulse rate is three times per second. 
     
     
         7 . The dispenser of  claim 1 , wherein the preset value is one hour. 
     
     
         8 . A method of operation for an electronic hands-free paper towel dispenser to dispense a sheet of web material, comprising
 initiating a dispense cycle upon detection of a user and scanning for the presence of a user with a sensor at a first pulse rate;   determining the time that has elapsed from the last dispense cycle and comparing the elapsed time with a preset value; and   setting the sensor to scan at a second pulse rate if the elapsed time is greater than the preset value.   
     
     
         9 . The method of  claim 8  wherein the sensor is an infrared sensor having an emitter and detector. 
     
     
         10 . The method of  claim 8  wherein the preset value is one hour. 
     
     
         11 . The method of  claim 8  wherein the first pulse rate is higher than the second pulse rate. 
     
     
         12 . The method of  claim 8 , wherein the first pulse rate is six times per second. 
     
     
         13 . The method of  claim 8 , wherein the second pulse rate is three times per second.