RESONANTLY DRIVEN POWER TOOTHBRUSH HAVING A PRESSURE-SENSING CAPABILITY USING A HALL EFFECT SENSOR

• US 20150230898A1
• Filed: 08/30/2013
• Published: 08/20/2015
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Miller, Kevin Arnold
• Granted Patent: US 10,441,393 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A46B 13/02 power-driven carriers
• CPC Class Codes: A46B 13/023 with means for inducing vibration to the bristles
• CPC Class Codes: A46B 15/0002 Arrangements for enhancing monitoring or controlling the brushing process
• CPC Class Codes: A46B 15/0004 with a controlling means
• CPC Class Codes: A46B 15/0012 with a pressure controlling device
• CPC Class Codes: A46B 15/0038 with signalling means
• CPC Class Codes: A61C 17/22 with brushes, cushions, cups, or the like brush bodies, e.g. arrangements of the bristles A46B
• CPC Class Codes: A61C 17/221 Control arrangements therefor
• CPC Class Codes: A61C 17/32 reciprocating or oscillating
• CPC Class Codes: A61C 17/34 driven by electric motor
• CPC Class Codes: A61C 17/3409 characterized by the movement of the brush body
• CPC Class Codes: A61C 17/3481 Vibrating brush body, e.g. by using eccentric weights

Abstract

The toothbrush includes a handle portion which includes a power drive system (14) and further includes a brushhead assembly (20), which includes a brushhead arm having a brush element (21) at a distal end thereof A drive train assembly (12) is responsive to a drive signal from the power assembly for converting the action of the power assembly to a motion of the brushhead assembly. A magnet (30) is secured to the rear of the drive train, with a Hall effect sensor (32) mounted within the magnetic field produced by the magnet as the toothbrush moves in operation. Pressure on the brush element produces a phase shift of the Hall sensor output. A processor (15) determines the value of the phase shift of the Hall sensor signal as pressure is applied to the brush member and produces a signal indicative of the pressure applied by using stored information (71) which relates phase shift to pressure for the particular appliance.

Claims

1. A power toothbrush, comprising:

a handle portion containing a power system;

a brushhead assembly, including a brush member having a bristle field at a distal end thereof;

a drive train assembly responsive to a drive signal of the power system for producing a motion of the brushhead assembly;

a magnet positioned so that it moves in conjunction with the brushhead assembly motion, the magnet producing a magnetic field;

a Hall effect sensor mounted within the magnetic field, wherein the Hall effect sensor detects a change in phase between the drive signal of the power system and the motion of the brushhead assembly as pressure on the bristle field changes; and

responds with a phase shift in a Hall effect sensor output signal relative to the phase of the drive signal; and

a microprocessor control for determining the phase shift of the Hall effect sensor output due to pressure on the bristle field during brushing operations and for producing a feedback signal indicative of said pressure, in accordance with stored information in the power toothbrush relating values of phase shift to pressure.

2. The power toothbrush of claim 1, wherein the processor is calibrated such that the Hall effect sensor output signal is coincident in phase with the drive signal under no-load conditions.

3. The power toothbrush of claim 1, including a zero crossing circuit for determining the phase shift.

5. The power toothbrush of claim 1, wherein the microprocessor control includes the capability of averaging the signal output of the Hall effect sensor over several cycles and for filtering noise from the Hall effect sensor signal output.

6. The power toothbrush of claim 1, wherein the microprocessor control uses the stored information to correlate the output of the Hall effect sensor with a first pre-established threshold and to provide feedback information to the user when pressure on the brush member exceeds the first threshold value.

7. The power toothbrush of claim 6, wherein the first threshold value represents a maximum pressure value.

8. The power toothbrush of claim 6, including a second pre-established threshold representing a minimum pressure value.

9. The power toothbrush of claim 1, wherein the output signal from the Hall effect sensor is continuous and the feedback signal from the microprocessor is also continuous, representing a continuous indication of pressure on the brush member.

10. The power toothbrush of claim 1, wherein the feedback information is in a form recognizable by the user.

4. (canceled)