U.S. patent application number 12/206199 was filed with the patent office on 2009-10-01 for power toothbrush with adjustable operation.
This patent application is currently assigned to KONINKLIJKE PHILIPS ELECTRONICS N.V.. Invention is credited to DANIEL BAYEH, SCOTT E. HALL, RON LILLEY.
Application Number | 20090241276 12/206199 |
Document ID | / |
Family ID | 34971879 |
Filed Date | 2009-10-01 |
United States Patent
Application |
20090241276 |
Kind Code |
A1 |
HALL; SCOTT E. ; et
al. |
October 1, 2009 |
POWER TOOTHBRUSH WITH ADJUSTABLE OPERATION
Abstract
The system changes frequency of the toothbrush to adjust the
amplitude of motion of the brush portion of the toothbrush. The
change in frequency occurs either manually or automatically. In the
manual embodiment, the user, via a switch and internal circuitry,
can adjust the operating frequency of the toothbrush which results
in a change of amplitude to a value which is most comfortable to
the user. In the automatic mode, the resonant frequency of the
toothbrush is determined upon initiation of the operation of the
toothbrush. The resonant frequency value is then offset by a
selected amount, usually higher than the resonant frequency; this
offset frequency is the operating frequency of the toothbrush.
Inventors: |
HALL; SCOTT E.; (ISSAQUAH,
WA) ; BAYEH; DANIEL; (SEATTLE, WA) ; LILLEY;
RON; (FEDERAL WAY, WA) |
Correspondence
Address: |
PHILIPS INTELLECTUAL PROPERTY & STANDARDS
P.O. BOX 3001
BRIARCLIFF MANOR
NY
10510
US
|
Assignee: |
KONINKLIJKE PHILIPS ELECTRONICS
N.V.
Eindhoven
NL
|
Family ID: |
34971879 |
Appl. No.: |
12/206199 |
Filed: |
September 8, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11814196 |
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PCT/IB2005/052141 |
Jun 28, 2005 |
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12206199 |
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60584760 |
Jun 30, 2004 |
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Current U.S.
Class: |
15/22.1 |
Current CPC
Class: |
A61C 17/221 20130101;
A61C 17/32 20130101 |
Class at
Publication: |
15/22.1 |
International
Class: |
A46B 13/00 20060101
A46B013/00 |
Claims
1. A manual system for changing the amplitude of motion of a brush
portion of a power toothbrush, comprising: a drive system for a
power toothbrush which operates at a selected frequency to move the
brush portion at a resulting amplitude; and a frequency adjustment
system, including a member operable by a user, for changing the
frequency of the drive system and hence the amplitude of motion of
the brush portion.
2. The system of claim 1, wherein the operable member is a
mechanical switch located on the handle of the toothbrush.
3. The system of claim 2, wherein the frequency adjustment system
includes a microprocessor which in turn includes a counter
responsive to the switch for changing the frequency output of a
timer by a selected amount wherein the frequency output controls
the frequency of the drive system.
4. The system of claim 1, wherein the frequency adjustment system
is operable any time that the toothbrush is on.
5. An automatic system for changing the amplitude of motion of a
brush portion of a power toothbrush, comprising: a drive system for
a power toothbrush for operating the toothbrush at a particular
frequency to produce a resulting amplitude; a system for
determining the resonant frequency of the toothbrush at a selected
time following initiation of operation of the toothbrush by a user;
and a frequency adjustment system, which controls the setting of
the operating frequency of the toothbrush at a value which is
offset by a preselected amount from the determined resonant
frequency.
6. The system of claim 5 wherein the resonant frequency
determination occurs approximately upon initiation of operation of
the toothbrush.
7. The system of claim 5 wherein the resonant frequency determining
system includes a microprocessor, under program control, for
determining phase shift values of current applied to a motor
portion of the drive system for a range of successive frequency
values which includes the resonant frequency, and for selecting the
resonant frequency of the toothbrush which is associated with a
minimum phase shift value.
8. The system of claim 5, wherein the set operating frequency is
higher than the resonant frequency.
Description
[0001] The invention generally relates to power toothbrushes and
more specifically concerns a system for adjusting the operation of
the toothbrush by adjusting the amplitude of the brush motion.
[0002] The operational parameters of a power toothbrush, in
particular, the frequency of the reciprocal motion of the brush
portion of the toothbrush and the amplitude of the motion are
typically established and set by the manufacturer prior to sale of
the toothbrush. In those toothbrushes which are resonant systems,
the operating frequency of the toothbrush is typically set at or
near the resonant frequency of the toothbrush.
[0003] The amplitude of a power toothbrush established by the
manufacturer may, however, not be optimal for a particular
toothbrush and/or a particular user. A somewhat different amplitude
then that established by the manufacturer may often be desirable to
provide a maximum response and a preferred sense/feel by a
particular user. Actual results from use of the toothbrush may also
vary depending upon the particular amplitude of toothbrush motion.
While amplitude may be adjusted by changing the power supplied to
the motor, this approach has practical limitations, due to magnetic
saturation in the motor and battery capacity.
[0004] It is desirable to be able to change the amplitude of the
brush after it leaves the manufacturer to optimize performance
and/or the sense of cleansing, without directly adjusting the
power.
[0005] Accordingly, the present invention in one embodiment is a
manual system for changing the amplitude of motion of a brush
portion of a power toothbrush, comprising: a drive system for a
power toothbrush which operates at a selected frequency to move the
toothbrush at a resulting amplitude; and a frequency adjustment
system, including a member operable by a user for changing the
frequency of the drive system and hence the amplitude of motion of
the brush portion.
[0006] Another embodiment is an automatic system for changing the
amplitude of motion of a brush portion of a power toothbrush,
comprising: a drive system for a power toothbrush for operating the
toothbrush at a particular frequency to produce a resulting
amplitude; a system for determining the resonant frequency of the
toothbrush at a selected time following initiation of operation of
the toothbrush by the user; and a frequency adjustment system,
which controls the setting of the operating frequency of the
toothbrush at a value which is offset from the determined resonant
frequency by a preselected amount.
[0007] FIG. 1 shows a power toothbrush with which the present
invention can be used.
[0008] FIG. 2 is a block diagram showing one embodiment of the
tunable toothbrush of the present invention.
[0009] FIG. 3 is a block diagram of another embodiment of the
tunable toothbrush of the present invention.
[0010] FIG. 4 is a flow chart for a software program used in the
embodiment of FIG. 3.
[0011] FIG. 1 shows a power toothbrush 10. As an example, power
toothbrush 10 includes a handle portion 12 and a head portion 14
attached to the handle portion. The handle portion includes a
stator 16 which is part of the motor for the toothbrush and
includes a drive coil 18. The motor is driven by a drive signal
produced by a signal source 20, which includes switching circuit
22.
[0012] Head portion 14 typically includes a stem portion 16 and a
brush portion 18 which is driven by operation of the motor.
Operating an on/off switch 28 results in the brush portion 18
moving at a selected frequency and amplitude.
[0013] In the present invention, the operation of the toothbrush 10
is adjusted by changing the operating frequency of the toothbrush,
which in the embodiments shown and described results in a change in
amplitude of the brush motion, as described in more detail below.
FIG. 2 shows a manual embodiment of the frequency adjusting system.
In the manual embodiment, the user operates a rocker switch 36 to
change the operating frequency of the toothbrush through the action
of a microprocessor 39. The action of rocker switch 36 is sensed by
an up/down counter 38 to determine the amount of increase or
decrease of the frequency of the signal to be provided by timer 40.
The up/down counter 38 loads timer 40, to which is applied a clock
signal 37 which provides the initial frequency of operation of the
appliance. The output of timer 40 is sent to a divide-by-two
circuit 42 which is used to produce a square wave, which is then
applied to inverters 46 and 48. The output of inverters 46, 48 is
applied to FETs 50 and 52 which control the application of current
to stator coil 54 of motor 16. Other electrical switches, such as
bipolar transistors, could be used in place of the FETs.
[0014] By operating rocker switch 36, a change of operating
frequency of the toothbrush is produced which in turn affects the
amplitude of the brush motion. The user operates the rocker switch
until an optimal "feel" or other desired result, occurs. Each
operation of the rocker switch will alter the frequency of
operation by a selected amount. The frequency selected by the user
may be higher or lower than the preset frequency and may be higher
or lower than the actual resonant frequency of the toothbrush. In
the embodiment shown, the user can operate the frequency adjustment
system at his/her convenience, even during brushing, to adjust the
amplitude to a preferred optimal value. Typically, as indicated
above, this value will be different than the frequency set by the
manufacturer.
[0015] It is possible, however, to limit the ability of the user to
change the frequency, and hence the amplitude, to some extent, such
as by providing a timer which must expire prior to the user being
able to change the frequency again. The timer could be, for
instance, set to limit the ability of the user to change the
frequency to once or perhaps twice during a normal brushing event,
which is typically two minutes.
[0016] FIG. 3 is a block diagram showing another embodiment,
specifically, an automatic toothbrush frequency/amplitude
adjustment system. In general in this embodiment, when the user
turns the toothbrush on, a system is initiated which determines the
resonant frequency of the toothbrush. This is done by sweeping
through a series of frequencies, the range of which includes the
value of the resonant frequency of the toothbrush. Once the
resonant frequency is determined by this sweeping of frequencies,
the actual operating frequency for the toothbrush is produced by
including an offset from the determined resonant frequency. This
value of frequency offset is established by the manufacturer. This
setting of the operating frequency occurs each time the user turns
on the toothbrush. Hence, changes in the resonant frequency of the
toothbrush over time can be automatically accommodated.
[0017] Referring now to FIG. 3, which shows the automatic
adjustment system, including a microprocessor 58, a timing register
60 in the microprocessor is first initialized. The timing register
60 then preloads a timer 62 which is also responsive to a clock 63.
The first frequency value established by the timing register is
typically the lowest frequency value in the "sweep" of frequencies,
although the sweep could occur from highest frequency to the lowest
frequency as well. The output of timer 62 (initially the lowest
frequency) is then applied to a divide-by-two circuit 64 which
produces a square wave, which is applied to inverting circuits 66
and 68.
[0018] The output from the inverters is then applied to FETs 70, 76
which produce a current which is applied to the stator coil 77 for
a short selected time, e.g. 1/10.sup.th second. The current in the
coil is sensed at 72 and the phase shift is measured at 74. As the
frequency values move through the resonance frequency of the
brushhead, the time necessary for the current to reverse will
change. The term "phase shift" here refers to the relationship
between the voltage drive (the square wave signal) and the zero
crossing of the current waveform. This value of phase shift as
defined above is applied to RAM 76 in the microprocessor, providing
a first value in a table of phase values. The timing register 60 is
then changed by a specific frequency value and the process is
repeated, until a table of phase shift values is established. When
the last frequency in the preselected "sweep" of frequencies
through a selected range is used, and the table is complete, the
resonant frequency is determined. The resonant frequency is
associated with the minimum value of phase shift in the table. The
operating frequency is then set, i.e. established, using the offset
frequency value determined by the manufacturer. This resulting
operating frequency value is then used to set the timing register
60 and the toothbrush is set to run for the specified amount of
time (time for brushing).
[0019] FIG. 4 is a flow chart of the software program in
microprocessor 58 for control of the automatic operation of the
appliance. First, timing register 60 is initialized, as shown in
block 90. The timing register 60 will initially be set at the
first, i.e. lowest, frequency in the frequency sweeping range
(although it could be the highest, as indicated above) to determine
the resonant frequency of the toothbrush. This value is then used
to preload the timer 62 as shown in block 92. The stator of the
motor is then run for a selected number (n) cycles using the first
frequency value, as shown at block 94.
[0020] The phase shift value resulting from this first frequency of
operation is then captured and stored in RAM 76 as shown at block
96. The frequency is then incremented by one step. This is
indicated at block 98, where the loop index or value (i) has its
value incremented by one, each time through the loop. This new loop
value of (i) is compared then to a value (m), which is the total
number of frequency steps in the frequency sweep process. This is
shown at block 100. If the new value of (i) is not greater than
(m), then timing register 60 is decremented, establishing a new
preload value for the timer 62, as shown in block 102.
[0021] This process is repeated, building a table of phase shift
values in RAM, until (i) is greater than (m). At this point, the
resonant frequency of the toothbrush system is determined by
ascertaining from the table in RAM the lowest value of the phase
shift and correlating it with the associated frequency of
operation. The preselected offset frequency set by the manufacturer
is then used to establish the run timing value for the toothbrush,
as shown at block 104. That value is used to set the timing
register at block 106. Once the timer is set from the timing
register, the appliance is then run for the time of the event, i.e.
the preset time for brushing, in accordance with the established
frequency value as shown at block 108.
[0022] Accordingly, a system has been described for adjusting the
operation of a power toothbrush, both manually and automatically,
by changing the frequency of the toothbrush.
[0023] Although a preferred embodiment of the invention has been
disclosed for purposes of illustration, it should be understood
that various changes, modifications and substitutions may be
incorporated without departing from the spirit of the invention,
which is defined by the claims which follow.
* * * * *