Position sensing toothbrush

Abstract

The toothbrush includes a handle portion ( 12 or 55 ) and a brushhead portion ( 14 or 57 ) with a bristle set ( 20 or 53 ) at one end of the brushhead. At least one sensor ( 16 or 56 is located either on the handle of the toothbrush or on the bristle set back plate ( 54 ) of the toothbrush. When the sensor is located on the handle of the toothbrush, the position of the brushhead is determined by a processor ( 44 or 58 ) relative to the inside or outside surfaces of the teeth on the basis of the temperature detected by the sensor, either the outside environmental temperature or the skin temperature of the user. When the sensor is located on the bristle set back plate, the determination is made on the basis of the position of the bristle set relative to the cheek of the user.

1 . A toothbrush capable of sensing the position of a bristle set portion thereof relative to the teeth, comprising:
 a toothbrush which includes a handle portion and a brushhead portion with a bristle set at one end thereof for cleaning the teeth of a user;   at least one sensor located on the toothbrush at such a location that it is outside the mouth when the bristle set is in position to brush the teeth, the sensor being responsive to temperature, or other skin characteristic, wherein the sensor is oriented such that it detects the temperature of the skin when the bristle set is in a position adjacent one of either the outside or inside surfaces of the teeth, and detects the environmental temperature outside the mouth or the absence of said other skin characteristic when the bristle set is in a position adjacent the other of the outside or inside surfaces of the teeth;   a processor within the toothbrush responsive to the temperature information or information of the other skin characteristic from the sensor for determining whether the bristle set is in position to brush the outside surfaces or inside surfaces of the teeth; and   an indication system responsive to the processor for indicating to the user the position of the bristle set relative to the teeth.   
     
     
         2 . The toothbrush of  claim 1 , including two sensors approximately 180° apart on the handle, each responsive to temperature and oriented such that when one sensor is measuring the skin temperature, the other is measuring the temperature outside of the mouth and vice versa. 
     
     
         3 . The toothbrush of  claim 1 , including an accelerometer or inclinometer, wherein information from the accelerometer or inclinometer is provided to the processor which determines which side of the mouth the bristle set is located. 
     
     
         4 . The toothbrush of  claim 1 , wherein the sensors are IR (infrared) sensors. 
     
     
         5 . The toothbrush of  claim 1 , wherein the sensors are located on the handle of the toothbrush. 
     
     
         6 . The toothbrush of  claim 1 , including two additional sensors for detecting the toothbrush being present relative to the teeth in the upper or lower jaws. 
     
     
         7 . The toothbrush of  claim 1 , wherein the toothbrush is a power toothbrush. 
     
     
         8 . The toothbrush of  claim 1 , wherein the indicator system is a visual display separate from the toothbrush. 
     
     
         9 . A toothbrush capable of sensing the position of a bristle set portion thereof relative to the teeth, comprising:
 a toothbrush which includes a handle portion and a brushhead portion, with a bristle set at one end thereof for cleaning the teeth of a user;   at least one sensor located on a back member for the bristle set for providing orienting information of the sensor relative to the cheek of the user;   a processor responsive to the orienting information to provide an output indicating whether the bristle set is positioned adjacent the outside surfaces of the teeth or the inside surfaces of the teeth; and   an indicator system responsive to the processor for indicating to the user whether the bristle set is in position to brush the outside surfaces of the teeth or the inside surfaces of the teeth.   
     
     
         10 . The toothbrush of  claim 9 , wherein the sensor is located on a back surface of the bristle set. 
     
     
         11 . The toothbrush of  claim 9 , wherein the sensor is an IR temperature sensor to distinguish between the cheek and the interior of the mouth. 
     
     
         12 . The toothbrush of  claim 9 , wherein the sensor is an optical fiber assembly which differentiates between the interior of the mouth and the cheek by the intensity of light present at a receiver end of the optical fiber from an LED source at a transmittal end thereof. 
     
     
         13 . The toothbrush of  claim 9 , wherein the sensor includes a capacitive element and a system for sensing the capacitance thereof, wherein the capacitance of the capacitive element increases when the bristle set is close to the cheek of the user as opposed to away from the cheek. 
     
     
         14 . The toothbrush of  claim 9 , wherein the sensor is an infrared LED and an infrared detector, wherein light intensity detected by the detector will decrease as the bristle set back member comes into contact with the cheek. 
     
     
         15 . The toothbrush of  claim 14 , including additional infrared LEDs and infrared detectors positioned on the back member for determination of additional bristle set positions relative to the teeth of the user. 
     
     
         16 . The toothbrush of  claim 9 , wherein the sensor is a switch, which is activated when the bristle set back member contacts the cheek of the user. 
     
     
         17 . A toothbrush capable of sensing how far a toothbrush penetrates into the mouth, comprising:
 a toothbrush, which includes a handle portion, a neck portion and a bristle set portion at a distal end of the neck portion for cleaning teeth of a user;   a plurality of sensor members positioned in sequence along the neck portion of the toothbrush, the sensor members oriented such that the relative number of sensor members within the mouth and outside of the mouth is indicative of the portion of the toothbrush which is in the mouth; and   a receiver for receiving information from uncovered sensor members outside of the mouth, wherein the receiver includes a system for indicating to the user how far the toothbrush has penetrated into the mouth from the sensor information.   
     
     
         18 . The toothbrush of  claim 17 , wherein the sensor members are light sources, and the receiver is adapted to receive light from uncovered light sources, wherein the light sources are differentiated from one another by a selected characteristic 
     
     
         19 . The toothbrush of  claim 17 , wherein the selected characteristic is frequency, such that the light sources emit different colored light. 
     
     
         20 . The toothbrush of  claim 19 , wherein the light sources are infrared LEDs, each having a different emitting frequency. 
     
     
         21 . The toothbrush of  claim 17 , wherein the sensor members are temperature sensors.