Short wavelength visible light-emitting toothbrush with an electronic signal interlock control

Abstract

A short wavelength visible light-emitting toothbrush with an electronic interlock control device preventing operation when the toothbrush is removed from the user's mouth. The electronic interlock control over operation is necessary to prevent accidental eye exposure to the high intensity light source with a wavelength in the range of 400 nm to 500 nm. The light-emitting toothbrush activates upon entering the user's mouth but deactivates immediately when removed, thus protecting the user's eyes from direct exposure to the high power light source contained in the brush head.

What is claimed is: 
     
         1 . A toothbrush having a light source comprising:
 a brush including a battery, a source of light with a wavelength in the range of about 400 nm to about 500 nm, electronics coupled to the battery and source of light to supply electricity from the battery to the source at current and voltage that causes the source to emit light, the brush including a handle and a distal end;   the distal end including bristles mounted on the distal end and the source of light;   at least a portion of the handle and at least a portion of the distal end being equipped with a sensor to determine whenever the distal end is outside the environment of the mouth and permits activation of the source of light only when the source of light is inside the mouth of the user, the sensor selected from the group consisting of: a capacitive sensor which detects current flowing through the body of a user when the brush head or bristles are in contact with the mouth and the handle is in contact with the hand; a capacitive displacement sensor that senses change of position of any conductive target such as the human body; an inductive sensor that uses an inductance loop to measure the proximity of conductors such as the human body; a passive thermal infrared that detects the warmth of the human mouth; a photoelectric sensor that detects reflected IR light emitted and absorbed by the sensor itself; a light sensor that is triggered by darkness inside the mouth; a light sensor that detects the reflection of light from a second light source on the brush when the brush is activated; an ultrasonic and active sonar sensors that uses echo location to detect the confines of the mouth; a magnetic detector that detects the proximity of metals such as the hemoglobin present in blood; a pressure sensor under the brush head that detects movement and pressure of the brush head being pressed against the teeth; a pressure sensor in the neck that detects torque and tension in the neck of the brush due to brushing action; a moisture sensor to detect a highly moist environment such as the mouth; and a combination of two or more of these sensor types;   a fingerprint sensor mounted on the handle to verify if the user is authorized; and   an alarm adapted to warn the user of the power status of the source of light.   
     
     
         2 . The toothbrush as claimed in  claim 1  wherein the alarm is a light emitter adapted to alert the user that the source of light is about to operate at full power through a gradual increase in the power from about 5% of full power, up to 100% of full power, for a period of between 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         3 . The toothbrush as claimed in  claim 2  wherein the light emitter operates by providing a short burst of low frequency light pulses or flashes, using a rectangular, saw-tooth, pulsed, sinusoidal or other types of common periodic waveforms, in the range of about 2 Hertz to about 10 Hertz at partial or full power, for a period of between about 0.5 seconds to about 2 seconds before the source of light reaches full power. 
     
     
         4 . The toothbrush as claimed in  claim 1  wherein the alarm is a vibrator coupled with a light emitter to warn the user of the power status of the source of light. 
     
     
         5 . The toothbrush as claimed in  claim 4  wherein the vibrator operates by providing a series of pulsed vibration for a period of between about 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         6 . The toothbrush as claimed in  claim 4  wherein the vibrator is a motor used to drive the bristles on the distal end of the brush. 
     
     
         7 . The toothbrush as claimed in  claim 1  wherein the alarm is an auditory device emitting a sound to warn the user of the power status of the source of light. 
     
     
         8 . The toothbrush as claimed in  claim 7  wherein the auditory device provides a pulsating beep for a period of between about 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         9 . A toothbrush as claimed in  claim 1  wherein the sensor includes a pressure sensor selected from the group consisting of piezoelectric, capacitive, potentiometric, optical or electromagnetic and combinations thereof. 
     
     
         10 . A toothbrush as claimed in  claim 1  wherein the sensor includes a moisture sensor that is a capacitive sensor, a chilled mirror dew point sensor, or combination thereof. 
     
     
         11 . A toothbrush having a light source comprising:
 a brush including a battery, a source of light with a wavelength in the range of about 400 nm to about 500 nm, electronics coupled to the battery and source of light to supply electricity from the battery to the source at current and voltage that causes the source to emit light, the brush including a handle and a distal end;   the distal end including bristles mounted on the distal end and the source of light;   a fingerprint sensor mounted on the handle to verify if a user is authorized;   an alarm mounted on the handle adapted to warn the user of the power status of the source of light; and   at least a portion of the handle and at least a portion of the distal end each having an electrically conductive exterior surface electrically connected to the electronics within the brush, the conductive surfaces separated from one another by a non-conductive region of one of the handle or distal end to create an open circuit, wherein the electronics has a control circuit to couple the battery and the source of light and the open circuit, which can be closed to sense when current from the battery is to be applied to the source of light;   whereby the user who uses the toothbrush to brush his or her teeth by grasping the handle and inserting the bristles into his or her mouth closes the open circuit to complete a signal loop that is sensed by the electronics to turn on the source of light, and removal of the distal end from the mouth opens the circuit to break the signal loop, turning off the source of light.   
     
     
         12 . The toothbrush as claimed in  claim 11  wherein the alarm is a light emitter alerts the user that the source of light is about to operate at full power through a gradual increase in the power from about 5% of full power, up to 100% of full power, for a period of between about 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         13 . The toothbrush as claimed in  claim 12  wherein the light emitter operates by providing a short burst of low frequency light pulses or flashes, using a rectangular, saw-tooth, pulsed, sinusoidal or other types of common periodic waveforms, in the range of about 2 Hertz to about 10 Hertz at partial or full power, for a period of between about 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         14 . The toothbrush as claimed in  claim 11  wherein the alarm is a vibrator coupled with a light emitter to warn the user of the power status of the source of light. 
     
     
         15 . The toothbrush as claimed in  claim 14  wherein the vibrator operates by providing a series of pulsed vibration for a period of between about 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         16 . The toothbrush as claimed in  claim 14  wherein the vibrator is a motor used to drive the bristles on the distal end of the brush. 
     
     
         17 . The toothbrush as claimed in  claim 11  wherein the alarm is an auditory device emitting a sound to warn the user of the power status of the source of light. 
     
     
         18 . A toothbrush having a light source comprising:
 a brush having a handle and a distal end, the brush including
 a battery, 
 a source of light with a wavelength in the range of 400 nm to 500 nm, 
 a fingerprint sensor mounted on the handle; 
 at least one status indicator mounted on the handle adapted to warn the user of the power status of the source of light; 
 electronics coupled to the battery, the fingerprint sensor, the status indicator and the source of light to supply electricity from the battery to the source of light at current and voltage that causes the source to emit a light, the fingerprint sensor coupled to the electronics to indicate whether the user is authorized, the electronics coupled to the status indicator to supply electricity from the battery to the status indicator; 
   a plurality of bristles and the source of light mounted on the distal end;   at least a portion of the handle and at least a portion of the distal end each being equipped with an electrical contact accessible on an exterior surface of the toothbrush, the electrical contacts completing a signal loop when both are in contact with a conductor;   wherein the electrical contacts act as sensors to determine whenever the distal end is outside the environment of the mouth and permits activation of the source of light only when the source of light is inside the mouth of the user and a signal loop is completed through the electrical contacts.   
     
     
         19 . The toothbrush as claimed in  claim 18  wherein the status indicator is selected from the group consisting of: a light emitter, a vibrational motor, and an auditory device. 
     
     
         20 . The toothbrush as claimed in  claim 19  wherein the status indicator operates by providing a series of pulsed feedback for a period of between about 0.5 seconds to about 5 seconds before the source of light reaches full power. 
     
     
         21 . A toothbrush having a light source comprising:
 a brush including a battery, a source of light with a wavelength in the range of about 400 nm to about 500 nm, electronics coupled to the battery and source of light to supply electricity from the battery to the source at current and voltage that causes the source to emit light, the brush including a handle and a distal end;   the distal end including bristles mounted on the distal end and the source of light; and   at least a portion of the handle and at least a portion of the distal end each having an electrically conductive exterior surface electrically connected to the electronics within the brush, the conductive surfaces separated from one another by a non-conductive region of one of the handle or distal end to create an open circuit, wherein the electronics has a control circuit to couple the battery and the source of light and the open circuit, which can be closed to sense when current from the battery is to be applied to the source of light, the control circuit continuing to supply power to the source of light if the closed circuit becomes open for a duration of between about 0.1 seconds to about 0.5 seconds;   whereby the user who uses the toothbrush to brush his or her teeth by grasping the handle and inserting the bristles into his or her mouth closes the open circuit to complete a signal loop that is sensed by the electronics to turn on the source of light, and removal of the distal end from the mouth opens the circuit to break the signal loop, turning off the source of light after the duration of between about 0.1 seconds to about 0.5 seconds.   
     
     
         22 . The toothbrush as claimed in  claim 21  wherein the control circuit supplies power to the source of light at less than 100% for the duration of between about 0.1 seconds to about 0.5 seconds when the closed circuit becomes open.