Electric toothbrush

Abstract

In an electric toothbrush having a removable brush part, power is stably supplied to an LED provided in the head part. 【Solution means】The electric toothbrush 1 includes a main body part 10 having a motor and a battery, and a brush part 20 that is detachable from the main body part 10. The brush part 20 has a head part 21 and a rod part 22. A non-contact transmission part 51 for transmitting an electric signal is provided at an end of the main body part 10 on the connection side with the brush part 20. A non-contact reception part 52 for receiving an electric signal from the non-contact transmission part 51 is provided at an end of the rod part 22 on the connection side with the main body part 10. An LED 35 that is lit by the electric signal received by the non-contact reception part 52 is provided in the head part 21.

Description

Technical Field

[0001] The present invention relates to an electric toothbrush that is used by attaching a brush part to a main body part.

Background Art

[0002] Some electric toothbrushes are used by attaching a detachable brush part to a main body part having a power source and a drive part. Also, some electric toothbrushes are provided with lighting such as an LED in a head part having brush bristles (see, for example, Patent Document 1 and Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electric toothbrush having a detachable brush part, since the main body part having a power source such as a battery and the brush part are separate parts, it is difficult to stably supply power to the brush part side. In particular, when the brush part vibrates frequently, the power supply from the main body part to the brush part side becomes unstable, and thus the lighting state of the LED provided in the brush part may become unstable.

[0005] Therefore, an object of the present invention is to provide a technique capable of stably supplying power to an LED provided in a head in an electric toothbrush having a detachable brush part.

Means for Solving the Problems

[0006] An electric toothbrush according to an aspect of the present invention includes a main body having a motor and a battery, and a brush part detachable from the main body. In this electric toothbrush, the brush part has a head part having brush bristles and a rod part connected to the main body part. A non-contact transmission part for transmitting an electric signal is provided at an end of the main body part on the connection side with the brush part, and a non-contact reception part for receiving the electric signal from the non-contact transmission part is provided at an end of the rod part on the connection side with the main body part. The head part is provided with an LED that lights up by the electric signal received by the non-contact reception part.

Advantages of the Invention

[0007] According to an aspect of the present invention, it is possible to provide an electric toothbrush capable of stably supplying power to an LED provided in a head part.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 15

Embodiments for Carrying Out the Invention

[0009] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

[0010] In the present embodiment, the electric toothbrush 1 as an example of the present invention will be described. The electric toothbrush 1 is used by attaching the brush unit 20 to the main body unit 10.

[0011] (Overall Configuration of Electric Toothbrush) First, the overall configuration of the electric toothbrush 1 according to the present embodiment will be described. FIGS. 1 to 3 show the appearance of the electric toothbrush 1. FIG. 2 shows a state where the brush unit 20 is removed from the main body unit 10.

[0012] In this specification, for the purpose of explaining the shape and positional relationship of each component of the electric toothbrush 1, for convenience, the electric toothbrush 1 is defined by three coordinate axes in the X (X1-X2) direction (left-right direction), Y (Y1-Y2) direction (up-down direction), and Z (Z1-Z2) direction (front-back direction) as shown in FIG. 1 and the like.

[0013] In the electric toothbrush 1 according to the present embodiment, the bristle 32 is provided on one side surface (specifically, the brush surface 31) of the brush unit 20 provided in a positional relationship substantially parallel to any one side surface (specifically, the front portion 10a) of the main body portion 10. Hereinafter, in the electric toothbrush 1, the side on which the brush surface 31 is provided is defined as the front side of the electric toothbrush 1.

[0014] The electric toothbrush 1 mainly includes a main body portion 10 and a brush unit 20. Since the main body portion 10 is a portion that serves as a handle when using the electric toothbrush 1, it is also called a grip portion. The brush unit 20 is configured to be detachable (removable) from the main body portion 10 (see FIG. 2). The brush unit 20 is positioned and attached so that the brush surface 31 on which the bristles 32 are implanted faces the main body portion 10 in a predetermined direction (that is, the Z1 direction). Thereby, the operation portion 12 of the main body portion 10 and the extending direction of the bristles 32 of the brush unit 20 are arranged to have a predetermined positional relationship.

[0015] Another brush unit different from the brush unit 20 or an attachment having a shape different from that of the brush unit 20 can be attached to the main body portion 10. Thereby, the electric toothbrush 1 can be used by a plurality of people, or the electric toothbrush 1 can be used for a wider range of applications.

[0016] (Configuration of the main body portion) The main body portion 10 has a columnar shape extending along the Y direction (vertical direction). In the present embodiment, the shape of the main body portion 10 is a hexahedral columnar shape in which the cross section (XZ cross section) is hexagonal (see FIG. 1). The outer shape of the main body portion 10 is formed by the main body case 11.

[0017] An operation unit 12 is provided on the outer peripheral surface of the main body case 11. In the present embodiment, the operation unit 12 is disposed on the side surface on the Z1 side (i.e., the front side), that is, the front surface portion 10a. When using the electric toothbrush 1, by the user operating the operation unit 12, the electric toothbrush 1 starts or stops operating. Also, by operating the operation unit 12, the vibration intensity, rotation angle, etc. of the brush unit 20 may be adjusted.

[0018] FIG. 4 shows the internal configuration of the main body 10. Inside the main body 10, a motor 13, a battery (electric cell) 14, a control board 15, etc. are provided.

[0019] The motor 13 is disposed on the upper side of the main body 10 (i.e., the side closer to the brush unit 20). A linkage shaft 16 for transmitting the driving force of the motor 13 to the brush unit 20 is connected to one end (the end on the Y1 side) of the motor 13. The linkage shaft 16 is connected to the rotation shaft 62 of the motor 13. A more detailed configuration of the motor 13 will be described later.

[0020] The battery 14 is disposed on the lower side of the main body 10 (i.e., the side farther from the brush unit 20). The battery 14 supplies power to each component (e.g., the motor 13, the control board 15, the LED 35, etc.) in the electric toothbrush 1. The battery 14 is composed of a primary battery or a secondary battery. When the battery 14 is a secondary battery, a power supply unit (not shown) for charging the battery 14 is provided.

[0021] The control board 15 is disposed on the front side (Z1 side) inside the main body case 11. The control board 15 controls the operation of the motor 13, the lighting state of the LED 35, etc. Above the control board 15, the operation button 12a of the operation unit 12 is disposed. By the user operating the operation button 12a, an instruction signal for performing a predetermined operation is transmitted from the operation unit 12 to the control board 15. By the control board 15 transmitting an operation command (control signal) to each component (e.g., the motor 13, the LED 35, etc.) based on the received instruction signal, each component in the electric toothbrush 1 performs the operation selected by the user.

[0022] (Configuration of the Brush Part) Next, a more detailed configuration of the brush part 20 will be described. FIG. 5 shows the internal configuration of the brush part 20 of the electric toothbrush 1. FIG. 5 is a cross-sectional view at a position corresponding to the A-A line of the brush part 20 shown in FIG. 3. FIG. 6 shows the internal configuration of the connection part between the brush part 20 and the main body part 10 of the electric toothbrush 1. FIG. 6 is a cross-sectional view when the connection part between the brush part 20 and the main body part 10 is cut at a position corresponding to the A-A line shown in FIG. 3.

[0023] The brush part 20 has a head part 21 having brush bristles 32 and an LED 35, etc., and a rod part 22 connected to the main body part 10. The head part 21 has a brush surface 31 where the brush bristles 32 are erected, and a head cover 33 provided so as to cover the brush surface 31.

[0024] The brush surface 31 is formed of, for example, a transparent or translucent resin material. The brush bristles 32 and the LED 35, etc. are arranged on this brush surface 31. The brush bristles 32 have a plurality of tufts formed of a plurality of thin resin bristles. A plurality of these tufts are arranged vertically and horizontally and embedded in the brush surface 31.

[0025] The LED 35 includes, for example, an element of a light-emitting diode (LED) that emits light in blue. In one example, the LED 35 is composed of an LED substrate on which a plurality of LED elements are arranged. This LED substrate is arranged so as to be fitted into a transparent resin plate forming the brush surface 31 (see FIG. 5). Thereby, the light emitted from the LED element passes through the transparent resin plate and is irradiated from the brush surface 31.

[0026] The LED 35 is controlled, for example, to light up when the electric toothbrush 1 is in an operating state. Thereby, when the user uses the electric toothbrush 1 to brush teeth, the inside of the oral cavity (especially the large molar parts on both the left and right sides) can be brightly illuminated, so that it is easy to confirm whether the teeth are being brushed cleanly.

[0027] LED 35 may be composed of a plurality of LED elements that emit light of different colors. Thereby, according to the operation mode of the electric toothbrush 1, the LED 35 can be made to emit light of different colors to notify the user of the operation mode.

[0028] The head cover 33 is formed of a relatively soft material (for example, an elastic resin material, a soft rubber material, a silicon material, etc.). Thereby, damage to the teeth due to the vibration of the head portion 21 of the electric toothbrush 1 during operation can be reduced. Note that the head cover 33 may be formed of a transparent material. Thereby, the light of the LED 35 can be irradiated to the outside not only from the brush surface 31 but also from the entire head portion 21.

[0029] The rod portion 22 is a rod-shaped portion extending in the Y direction (vertical direction). The upper end side (Y1 side) of the rod portion 22 is connected to the head portion 21, and the lower end side (Y2 side) of the rod portion 22 is a connection portion with the main body portion 10. A base member 41 is provided on the lower end side (Y2 side) of the rod portion 22.

[0030] FIG. 7 shows the appearance of the base member 41 included in the brush portion 20. FIG. 8 shows a state in which the receiving coil 52 is attached to the base member 41.

[0031] The base member 41 has a bottom surface portion 42, a column body 43, a insertion hole 44, a wiring path 45, etc. The bottom surface portion 42 forms the bottom surface of the brush portion 20. As shown in FIG. 6, in a state where the brush portion 20 is attached to the main body portion 10, the bottom surface portion 42 is close to the upper surface portion 10b of the main body portion 10.

[0032] Two protrusions 47 are provided on the bottom surface portion 42. The two protrusions 47·47 are respectively arranged at positions facing each other (that is, at a substantially 180-degree angle) on the outer edge portion of the upper surface of the substantially circular bottom surface portion 42.

[0033] The column body 43 is a columnar portion extending from the bottom surface portion 42 toward the head portion 21 side. The column body 43 is fitted into the hollow portion on the lower side (Y2 side) of the main body portion of the rod portion 22 (see FIG. 5). A insertion hole 44 is formed inside the column body 43. The insertion hole 44 is a hole extending through the column body 43 from the bottom surface portion 42 toward the upper side (Y1 side).

[0034] The interlocking shaft 16 of the main body portion 10 is inserted into the insertion hole 44. In a state where the interlocking shaft 16 is inserted into the insertion hole 44, the first vertical surface 16a of the interlocking shaft 16 faces the front side (Z1 side), and the second vertical surface 16b faces the rear side (Z2 side) (see FIG. 6). Thus, when attaching the brush portion 20 to the main body portion 10, they are connected in a state where they are positioned so that their front sides (that is, the brush surface 31 and the front portion 10a) face the same direction.

[0035] The wiring path 45 has a groove extending in the vertical direction (Y direction) on the outer surface of the column body 43. A wiring 53 extending from the receiving coil 52 to the LED 35 is disposed in the groove of the wiring path 45. In FIG. 6, the wiring 53 is shown by a broken line. The wiring path 45 has, in order from above along the extending direction of the groove, a wiring hole 45a, a first inclined portion 45b, a vertical portion 45c, and a second inclined portion 45d.

[0036] An elastic joint portion 46 is provided below the second inclined portion 45d. The elastic joint portion 46 elastically deforms when the interlocking shaft 16 of the main body portion 10 is inserted into the insertion hole 44. By providing such an elastic joint portion 46, the insertion operation of the interlocking shaft 16 when the user attaches the brush portion 20 becomes easier. Also, by providing the elastic joint portion 46, the interlocking shaft 16 can be fitted into the insertion hole 44 in a more closely attached state. Thereby, the rotational force of the motor 13 can be transmitted to the brush portion 20 more reliably.

[0037] The base member 41 is provided with a receiving coil (non-contact receiving unit) 52 for receiving an electrical signal (power) from the battery 14 in the main body 10. The electrical signal received by the receiving coil 52 is transmitted to the LED 35 via the wiring 53.

[0038] As will be described later, the rod portion 22 and the base member 41 have a configuration (specifically, the bottom surface portion 42, the column body 43, the protrusion 47, the stopper ring 26, etc.) suitable for fixedly arranging the receiving coil 52 inside the rod portion 22.

[0039] (Power supply to the LED) Subsequently, a method of supplying power to the LED 35 of the brush portion 20 will be described. When the main body 10 and the brush portion 20 are configured as separate components as in the electric toothbrush 1 according to the present embodiment, it is difficult to stably supply primary power from the main body 10 to the brush portion 20 that vibrates frequently. Also, although it is an idea to incorporate a power source for the LED 35 such as a battery inside the brush portion 20, there is also a problem that the size of the brush portion 20 becomes large and it becomes difficult to brush teeth.

[0040] In the electric toothbrush 1 of the present embodiment, the principle of wireless inductive charging is adopted, and power is supplied from a transmitting coil (non-contact transmitting unit) 51 arranged on the upper part (Y1 side) of the main body 10 to a receiving coil (non-contact receiving unit) 52 arranged on the lower part (Y2 side) of the brush portion 20. When the transmitting coil 51 in the main body 10 transmits electromagnetic waves upward, the receiving coil 52 on the brush portion 20 side receives this and generates electric power. Then, power is supplied to the LED 35 of the head portion 21 through the wiring 53 arranged inside the brush portion 20. Thereby, the LED 35 can be lit.

[0041] The transmitting coil 51 is arranged at a position close to the upper surface portion 10b of the main body 10 (see FIG. 6). In one example, the transmitting coil 51 has an annular shape and is arranged so as to surround the interlocking shaft 16. The transmitting coil 51 is a wireless inductive transmitting end, and uses the power supplied from the battery 14 in the main body 10 to transmit an electrical signal (electromagnetic wave) toward the brush portion 20.

[0042] The receiving coil 52 is disposed at a position close to the bottom surface portion 42 of the brush portion 20 (see FIG. 6). In one example, the receiving coil 52 has an annular shape and is disposed so as to surround the columnar body 43 (see FIG. 8). The transmitting coil 51 is a wireless sensitive receiving end and receives an electrical signal (electromagnetic wave) transmitted from the transmitting coil 51. The electrical signal received by the receiving coil 52 is converted into electric power. The converted electric power is supplied to an LED 35 (specifically, an LED substrate) provided in the head portion 21 through the wiring 53.

[0043] With the above-described configuration, stable energization can be performed between the brush portion 20 and the main body portion 10 in a non-contact state. Therefore, the LED 35 can be lit using the power supply from the battery 14 in the main body portion 10.

[0044] Further, in the electric toothbrush 1 according to the present embodiment, since the brush portion 20 can be operated with a larger swing width by the motor 13, a positional deviation is likely to occur in the receiving coil 52 in the brush portion 20. Therefore, the electric toothbrush 1 has a configuration for fixedly disposing the receiving coil 52 in the rod portion 22.

[0045] Specifically, an annular receiving coil 52 is disposed on the base member 41 so as to surround the columnar body 43. A plurality (for example, two) of protrusions 47 are provided on the outer periphery of the bottom surface portion 42 of the base member 41, and the inner periphery and the outer periphery of the annular receiving coil 52 are supported by the protrusions 47 and the columnar body 43. Thereby, the movement of the receiving coil 52 in the left-right direction (X direction) and the front-rear direction (Z direction) (that is, the horizontal movement) can be suppressed.

[0046] Furthermore, an annular stopper ring 26 is disposed above the annular receiving coil 52 (see FIG. 6). Thereby, the receiving coil 52 is sandwiched between the stopper ring 26 and the bottom surface portion 42, and the vertical space is limited. Thereby, the movement of the receiving coil 52 in the vertical direction (Y direction) can be suppressed.

[0047] With the above configuration, the receiving coil 52 can be firmly fixed around and above and below, so that a stable power supply can be provided to the brush portion 20 during operation. As a result, the LED 35 can be stably lit even in a strong vibration state.

[0048] As described above, the rod portion 22 and the base member 41 have a configuration (specifically, the bottom surface portion 42, the column body 43, the protrusion 47, the stopper ring 26, etc.) suitable for fixedly arranging the receiving coil 52 within the rod portion 22. Thereby, power can be stably supplied even when the brush portion 20 is vibrating (operating), and the lighting state of the LED 35 can be stabilized.

[0049] (Configuration of the motor) Subsequently, a more detailed configuration of the motor 13 will be described. FIG. 9 shows the external configuration of the motor 13. FIG. 10 shows the internal configuration of the motor 13. FIG. 11(a) shows a schematic configuration of a cross-section (a cross-section in a direction perpendicular to the rotation axis) of the motor 13.

[0050] In one example, the motor 13 is a brushless motor. By adopting a brushless motor as the motor 13, the torque can be enhanced with a strong magnetic force, so that a stronger brushing force can be realized in the operation of the head portion 21. For example, by adopting a 7.4-volt brushless motor and a strong magnet, a torque more than twice as large as that of a conventional ultrasonic motor can be exerted.

[0051] The motor 13 has a motor case 61, a rotating shaft 62, a magnet 63, a coil 64, a circular magnet 65, and a sensor portion 66, etc.

[0052] The motor case 61 houses various components such as a rotating shaft 62, a magnet 63, a coil 64, a circular magnet 65, and a sensor unit 66. The rotating shaft 62 extends in the vertical direction (Y direction) within the motor case 61. The upper end portion (the end portion on the Y1 side) of the rotating shaft 62 is connected to the interlocking shaft 16. As a result, the driving force of the motor 13 (specifically, the rotating shaft 62) is transmitted to the interlocking shaft 16, and the interlocking shaft 16 vibrates (rotates) in a predetermined direction with the shaft as a fulcrum.

[0053] The magnet 63 is provided on the outer periphery of the rotating shaft 62. The magnet 63 has an N pole and an S pole. A plurality of coils 64 are provided so as to surround the outer periphery of the magnet 63. In one example, six coils 64 are provided (see Fig. 11(a)).

[0054] The circular magnet 65 and the sensor unit 66 are arranged on the lower end portion (the end portion on the Y2 side) side of the motor 13. In one example, the sensor unit 66 is a Hall sensor. The sensor unit 66 has two sensor elements 66a and 66b. By providing the circular magnet 65 and the sensor unit 66, the position of the rotating shaft 62 can be specified.

[0055] Specifically, by specifying the position of the circular magnet 65 to which the sensor unit 66 is attached to the lower end portion of the rotating shaft 62, the position (rotation angle) of the rotating shaft 62 can be specified. Note that the position of the circular magnet 65 and the position of the head portion 21 attached via the interlocking shaft 16 are arranged corresponding to each other.

[0056] The position information of the rotating shaft 62 detected by the sensor unit 66 is transmitted to the control circuit within the control board 15. The control circuit can adjust the rotation angle of the head portion 21 (see Fig. 11(b)) in real time based on the transmitted position information. As a result, precise control of the operation of the head portion 21 can be realized.

[0057] (Vibration control method of the brush unit) Subsequently, the vibration control method of the brush unit 20 in the electric toothbrush 1 will be described.

[0058] In a conventional ultrasonic vibration type electric toothbrush, a magnetic field that changes regularly by electromagnetic induction is generated, and using the interaction between the magnet and magnetic force inside the motor, the rotating shaft (shaft) is rotated (vibrated) regularly. In this case, the rotation angle on each side is about 2 degrees. Since the tip of the rotating shaft is connected to the brush head via the operating shaft, the brush head also vibrates regularly. At this time, the frequency of the current input to the motor is a high frequency of about 250 Hz (see Fig. 15), and a periodic change in the current direction occurs about 250 times per second. As a result, a reciprocating motion of about 15,000 times (250×60) per minute is performed, and a brushing operation at a high frequency is realized.

[0059] In the electric toothbrush 1 according to the present embodiment, in addition to the high-frequency vibration of the conventional ultrasonic motor, a low-frequency electric control method is added. That is, a high-frequency signal and a low-frequency signal are superimposed and applied to the motor 13. As a result, not only the vibration of the brush part 20 at a narrow angle (for example, about 2 to 5 degrees) but also the sweeping (sweep) of the brush part 20 at a wide angle (for example, about 10 to 30 degrees) can be realized (see Fig. 11(b)).

[0060] Fig. 12 shows the frequency of the current input to the motor 13. The current input to the motor 13 includes two types: a high-frequency current H and a low-frequency current L. In the waveform diagram shown in Fig. 12, the frequency of the high-frequency current H is 250 Hz, and the frequency of the low-frequency current L is 1 Hz.

[0061] When the high-frequency current H is input to the motor 13, similar to the conventional electric toothbrush (see Fig. 15), for example, a reciprocating motion of about 250 times per second is performed, and a brushing operation at a high frequency is realized. Furthermore, when the low-frequency current L is input to the motor 13, two complete sine waves appear per second, and for example, a reciprocating motion of two times per second is performed.

[0062] When these two types of waveforms overlap, a composite waveform is generated as shown in Fig. 13. This waveform is generated by the simultaneous action of high-frequency vibration (about 250 Hz) and low-frequency sweep (about 1 Hz), and has a waveform structure in which two currents are superimposed. Due to the combination of high frequency and low frequency, the waveform exhibits the characteristics of both small-amplitude high-frequency vibration and large-amplitude low-frequency sweep.

[0063] In the electric toothbrush 1 according to this embodiment, by showing an operation waveform as shown in Fig. 13, it is possible to realize a wide-angle sweep operation over a wide range while the head portion 21 maintains fine high-frequency vibration during operation. As a result, the cleaning effect of brushing teeth when using the electric toothbrush 1 can be significantly improved.

[0064] The frequency of the high-frequency current H is, for example, a frequency within the range of 50 Hz or more and 600 Hz or less. Also, the frequency of the low-frequency current L is, for example, a frequency within the range of 0.5 Hz or more and 50 Hz or less.

[0065] Note that by adopting a low-frequency electric control method, the head portion 21 does not move symmetrically left and right, but deflects in one direction. When the head portion 21 deflects in one direction, large-angle brushing becomes possible (see Fig. 11(b)).

[0066] Also, the sensor unit 66 may recognize the magnetic field output by the circular magnet 65 attached to the rotation shaft 62, and the sensor unit 66 may output the current position of the head portion 21. As a result, after deflecting the brush portion 20 at a large angle, when a specific angle is reached, the brush portion 20 can be deflected in the reverse direction. By finely adjusting the rotation angle using the sensor unit 66 in this way, the head portion 21 can perform a low-frequency reciprocating motion within the set large-angle range.

[0067] (Method for Controlling the Rotation Angle of the Brush Portion) Subsequently, a method for controlling the rotation angle of the brush portion 20 in the electric toothbrush 1 will be described.

[0068] In the electric toothbrush 1 according to this embodiment, the sensor unit 66 provided in the motor 13 detects the current position of the head unit 21, making it possible to control the rotation angle of the head unit 21. As a result, the user of the electric toothbrush 1 can set the rotation angle of the head unit 21 to a preferred angle within a predetermined range.

[0069] The circular magnet 65 disposed on the lower end portion (the end portion on the Y2 side) of the motor 13 has an N pole and an S pole. The magnetic field generated by this circular magnet 65 acts on the sensor unit 66 disposed below (on the Y2 side) the circular magnet 65.

[0070] As described above, since the position of the rotating shaft 62 to which the circular magnet 65 is attached and the position of the head unit 21 are arranged corresponding to each other, when the direction of the magnetic field formed around the circular magnet 65 is known, the angle (position) of the brush surface 31 of the head unit 21 can also be specified.

[0071] When the rotating shaft 62 rotates at different angles, the magnetic force at a specific point within the action range of the magnetic field is different. Based on this basic principle, the position of the rotating shaft 62 is identified using two sensor elements 66a and 66b in the sensor unit 66. Different magnetic fields formed at different angles act on the two different-positioned sensor elements 66a and 66b, generating magnetic flux data that uniquely corresponds to angles from 1 degree to 360 degrees.

[0072] Here, let the magnetic flux density value measured by the first sensor element 66a be b1, and the magnetic flux density value measured by the second sensor element 66b be b2. Due to the different magnetic flux densities, each of the sensor elements 66a and 66b outputs a different voltage (see FIG. 14). This is based on the principle that the direction and intensity of the magnetic field affect the direction and intensity of the current, and the change in voltage can be derived by an algorithm. Since the rotating shaft 62 changes on the 360-degree circumference, the change in voltage shows a sine wave shape.

[0073] By simultaneously measuring with two sensor elements 66a and 66b, as shown in FIG. 14, two sine wave curves are generated. These sine wave curves are processed by an algorithm to obtain a unique solution for angles from 1 degree to 360 degrees. By using this unique solution, the current position of the rotation axis 62 can be accurately measured.

[0074] The specific calculation formula (function calculation representing the ratio of the magnetic flux amounts b2 / b1) is as follows. θ = f(b2 / b1) (Equation 1) In Equation 1, θ is the angle of the circular magnet 65, f is a function of the magnetic flux amount, b1 is the value of the magnetic flux density measured by the first sensor element 66a, b2 is the value of the magnetic flux density measured by the second sensor element 66b, That is.

[0075] In the above Equation 1, the specific angle of the circular magnet 65 is calculated using the values of the magnetic flux density obtained from the two sensor elements 66a and 66b. Thereby, it becomes possible to accurately identify the position of the rotation axis 62 having the circular magnet 65.

[0076] Based on the above content, the control circuit in the control board 15 uses an electric control program to adjust the current and frequency applied to the plurality of coils 64 of the motor 13. In this way, the rotation angle and frequency of the rotation axis 62 of the motor 13 can be accurately controlled.

[0077] By controlling the operation of the motor 13 in the above - described manner, the head unit 21 can reciprocate within the set angle range and can also operate at an angle according to the user's preference.

[0078] (Summary) As described above, an electric toothbrush according to an aspect of the present invention (for example, electric toothbrush 1) includes a main body portion (for example, main body portion 10) having a motor (for example, motor 13) and a battery (for example, battery 14), and a brush portion (for example, brush portion 20) that is detachable from the main body portion. The brush portion includes a head portion (for example, head portion 21) having brush bristles (for example, brush bristles 32), and a rod portion (for example, rod portion 22) connected to the main body portion. A non-contact transmission portion (for example, transmission coil 51) for transmitting an electric signal is provided at an end portion (for example, the end portion on the Y1 side) of the main body portion on the connection side with the brush portion. A non-contact reception portion (for example, reception coil 52) for receiving the electric signal from the non-contact transmission portion is provided at an end portion (for example, the end portion on the Y2 side) of the rod portion on the connection side with the main body portion. An LED (for example, LED 35) that lights up by the electric signal received by the non-contact reception portion is provided in the head portion.

[0079] According to the above configuration, by utilizing the principle of wireless inductive charging, the power from the battery in the main body portion can be supplied to the LED provided in the head portion. Therefore, in an electric toothbrush having a removable brush portion, the LED can be stably lit even when the head portion is in operation.

[0080] In an electric toothbrush according to an aspect of the present invention (for example, electric toothbrush 1), a base member (for example, base member 41) for fixedly arranging the non-contact reception portion (for example, reception coil 52) may be provided at an end portion (for example, the end portion on the Y2 side) of the rod portion (for example, rod portion 22) on the connection side with the main body portion (for example, main body portion 10).

[0081] According to the above configuration, by providing the base member, it is possible to suppress the non-contact reception portion from vibrating within the operating brush portion. Therefore, for example, even in the case of an electric toothbrush having a motor capable of performing strong swing vibration, power can be stably supplied to the LED provided in the head portion.

[0082] In an electric toothbrush according to an aspect of the present invention (for example, electric toothbrush 1), the base member (for example, base member 41) has a column (for example, column 43) extending toward the head portion side (for example, Y1 side), and the non-contact receiving portion (for example, receiving coil 52) may have an annular shape surrounding the column.

[0083] According to the above configuration, in the brush portion during operation, it is possible to suppress the swaying and vibration of the non-contact receiving portion in the horizontal direction (the direction of the XY plane). Therefore, for example, even in the case of an electric toothbrush having a motor capable of performing a strong swinging vibration, it is possible to stably supply power to the LED provided in the head portion.

[0084] In an electric toothbrush according to an aspect of the present invention (for example, electric toothbrush 1), the main body portion (for example, main body portion 10) is connected to the motor (for example, motor 13) and has an interlocking shaft (for example, interlocking shaft 16) for transmitting the driving force of the motor to the brush portion (for example, brush portion 20). The rod portion (for example, rod portion 22) is provided with an insertion hole (for example, insertion hole 44) into which the interlocking shaft is fitted, and a high-frequency signal and a low-frequency signal may be superimposed and applied to the motor.

[0085] According to the above configuration, during operation of the electric toothbrush, the head portion can perform a wide-angle sweep operation by a low-frequency signal while performing a fine vibration by a high-frequency signal. Thereby, the cleaning effect of brushing teeth when using the electric toothbrush can be significantly improved.

[0086] In an electric toothbrush according to an aspect of the present invention (for example, electric toothbrush 1), a circular magnet (for example, circular magnet 65) and a sensor portion (for example, sensor portion 66) for detecting the position of the circular magnet may be provided at one end portion in the axial direction of the motor (for example, the end portion far from the head portion 21).

[0087] According to the above configuration, the position of the rotation axis of the motor to which the circular magnet is attached can be specified by the sensor unit. Thereby, the rotation angle of the head unit during the operation of the electric toothbrush can be changed within a set range. Therefore, it becomes possible to operate the head unit at a rotation angle according to the preference of the user.

[0088] It should be considered that all aspects of the embodiments disclosed this time are illustrative and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and all modifications within the meaning and scope equivalent to the claims are intended to be included. Also, the configurations obtained by combining the configurations of different embodiments described in this specification with each other are also included in the scope of the present invention.

Explanation of Reference Numerals

[0089] 1: Electric toothbrush 10: Main body unit 12: Operation unit 13: Motor 14: Battery 15: Control board 16: Interlocking shaft 20: Brush unit 21: Head unit 22: Rod unit 31: Brush surface 32: Brush bristles 33: Head cover 35: LED 41: Base member 43: Column body 44: Insertion hole 45: Wiring path 47: Projection 51: Transmitting coil (non-contact transmitting unit) 52: Receiving coil (non-contact receiving unit) 61: Motor case 62: Rotation axis 65: Circular magnet 66: Sensor unit

Claims

1. a main body having a motor and a battery; a brush part that is detachable from the main body part; An electric toothbrush comprising: The brush portion includes: A head portion having brush bristles; A rod portion connected to the main body portion; It has a non-contact transmission unit that transmits an electrical signal is provided at an end of the main body that is connected to the brush unit, a non-contact receiving unit that receives the electrical signal from the non-contact transmitting unit and a base member that fixes and positions the non-contact receiving unit are provided at an end of the rod unit that is connected to the main body unit; The base member has a protrusion provided on an outer periphery of a bottom surface portion and a column extending toward the head portion, the non-contact receiving unit has an annular shape surrounding the columnar body, and the protrusion and the columnar body support an inner periphery and an outer periphery of the non-contact receiving unit having the annular shape; The head unit is provided with an LED that is turned on in response to the electrical signal received by the non-contact receiving unit. Electric toothbrush.

2. The main body portion has a linkage shaft connected to the motor and transmitting the driving force of the motor to the brush portion, The rod portion is provided with an insertion hole into which the interlocking shaft is fitted, A high-frequency signal and a low-frequency signal are superimposed and applied to the motor. The electric toothbrush of claim 1.

3. A circular magnet and a sensor unit for detecting the position of the circular magnet are provided at one end of the axial direction of the motor. The electric toothbrush according to claim 2.

4. The sensor unit is a Hall sensor having two sensor elements, The sensor unit identifies a position of the circular magnet attached to the rotation shaft of the motor, thereby identifying a rotation angle of the rotation shaft, and adjusts the rotation angle of the head unit via the interlocking shaft connected to the rotation shaft. The electric toothbrush according to claim 3.

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