electric toothbrush

Abstract

In an electric toothbrush having a removable brush head, power is stably supplied to an LED located on the head. [Solution] The electric toothbrush 1 comprises a main body 10 having a motor and a battery, and a brush part 20 that is detachable from the main body 10. The brush part 20 has a head part 21 and a rod part 22. A non-contact transmitting unit 51 that transmits electrical signals is provided at the end of the main body 10 that connects to the brush part 20. A non-contact receiving unit 52 that receives electrical signals from the non-contact transmitting unit 51 is provided at the end of the rod part 22 that connects to the main body 10. The head part 21 is provided with an LED 35 that lights up in response to the electrical signals received by the non-contact receiving unit 52.

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 removable brush part to a main body part having a power source and a drive part, etc. Also, some electric toothbrushes have lighting such as an LED provided 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 removable 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 supply stable 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, so there is a possibility that the lighting state of the LED provided in the brush part becomes 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 removable brush part.

Means for Solving the Problems

[0006] An electric toothbrush according to one aspect of the present invention comprises a main body having a motor and a battery, and a brush part that is 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. A non-contact transmitting unit for transmitting an electrical signal is provided at the end of the main body on the side connected to the brush part, and a non-contact receiving unit for receiving the electrical signal from the non-contact transmitting unit is provided at the end of the rod part on the side connected to the main body, and an LED is provided on the head part that lights up in response to the electrical signal received by the non-contact receiving unit. [Effects of the Invention]

[0007] According to one aspect of the present invention, it is possible to provide an electric toothbrush that can stably supply power to an LED provided in the head portion. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view showing the appearance of an electric toothbrush according to one embodiment. [Figure 2] Figure 1 is a perspective view showing the electric toothbrush in a disassembled state, with the main body and brush head separated. [Figure 3] Figure 1 is a front view of the electric toothbrush. [Figure 4] This is a perspective view showing the internal structure of the main body of an electric toothbrush. [Figure 5] This is a cross-sectional view showing the internal structure of the brush head of an electric toothbrush. [Figure 6] This is a cross-sectional view showing the internal structure of the connection between the brush head and the main body of an electric toothbrush. [Figure 7] This is a perspective view showing the appearance of the base member provided in the brush section. [Figure 8] This is a perspective view showing the receiving coil attached to the base component. [Figure 9] This is a side view showing the configuration of the motor inside the main unit. [Figure 10]It is an exploded perspective view showing the internal structure of the motor. [Figure 11] (a) is a schematic cross-sectional view showing the internal structure of the motor. (b) is a schematic view for explaining the operation of the head part by the motor. [Figure 12] It is a waveform diagram showing the frequencies of two types of currents input to the motor of the electric toothbrush according to one embodiment. [Figure 13] It is a diagram showing the waveform of the frequency when the two types of currents shown in Fig. 12 are superimposed. [Figure 14] It is a diagram showing the relationship between the magnetic flux density measured by the two sensor elements of the sensor part and the voltage. [Figure 15] It is a waveform diagram showing the frequency of the current input to the motor of the conventional ultrasonic vibration type electric toothbrush.

Mode 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 part 20 to the main body part 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 part 20 is removed from the main body part 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 etc.

[0013] In the electric toothbrush 1 according to this embodiment, the brush bristles 32 are provided on one side surface (specifically, the brush surface 31) of the brush part 20 provided in a positional relationship substantially parallel to any one side surface (specifically, the front part 10a) of the main body part 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 part 10 and a brush part 20. Since the main body part 10 is a part that serves as a handle when using the electric toothbrush 1, it is also called a gripping part. The brush part 20 is configured to be detachable (removable) from the main body part 10 (see FIG. 2). The brush part 20 is positioned and attached so that the brush surface 31 on which the brush bristles 32 are implanted faces the main body part 10 in a predetermined direction (that is, the Z1 direction). Thereby, the operation part 12 of the main body part 10 and the extending direction of the brush bristles 32 of the brush part 20 are arranged in a predetermined positional relationship.

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

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

[0017] An operating section 12 is provided on the outer circumferential surface of the main body case 11. In this embodiment, the operating section 12 is located on the side surface (i.e., the front surface 10a) on the Z1 side (i.e., the front side). When using the electric toothbrush 1, the user operates the operating section 12 to start or stop the electric toothbrush 1. In addition, the vibration intensity and rotation angle of the brush section 20 may be adjusted by operating the operating section 12.

[0018] Figure 4 shows the internal configuration of the main unit 10. The main unit 10 contains a motor 13, a battery 14, a control board 15, and the like.

[0019] The motor 13 is located on the upper side of the main body 10 (i.e., closer to the brush section 20). An interlocking shaft 16 is connected to one end of the motor 13 (the end on the Y1 side) to transmit the driving force of the motor 13 to the brush section 20. The interlocking 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 located on the lower side of the main body 10 (i.e., the side further away from the brush 20). The battery 14 supplies power to each component in the electric toothbrush 1 (e.g., the motor 13, control board 15, LED 35, etc.). The battery 14 is composed of either a primary or secondary battery. If 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 located 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 status of the LED 35, etc. Above the control board 15 are the operation buttons 12a of the operation unit 12. When the user operates the operation buttons 12a, an instruction signal for performing a predetermined operation is transmitted from the operation unit 12 to the control board 15. Based on the received instruction signal, the control board 15 transmits operation commands (control signals) to each component (e.g., the motor 13, LED 35, etc.), so that each component in the electric toothbrush 1 performs the operation selected by the user.

[0022] (Composition of the brush section) Next, the more detailed configuration of the brush section 20 will be described. Figure 5 shows the internal configuration of the brush section 20 of the electric toothbrush 1. Figure 5 is a cross-sectional view taken at the position corresponding to line AA of the brush section 20 shown in Figure 3. Figure 6 shows the internal configuration of the connection portion between the brush section 20 and the main body section 10 of the electric toothbrush 1. Figure 6 is a cross-sectional view taken when the connection portion between the brush section 20 and the main body section 10 is cut at the position corresponding to line AA shown in Figure 3.

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

[0024] The brush surface 31 is formed of, for example, a transparent or translucent resin material. Brush bristles 32 and LEDs 35 are arranged on this brush surface 31. The brush bristles 32 have multiple bundles of bristles, each made up of multiple thin resin bristles. Multiple of these bundles are embedded in the brush surface 31, arranged vertically and horizontally.

[0025] LED35 includes, for example, a light-emitting diode (LED) element that emits blue light. In one example, LED35 is composed of an LED substrate on which multiple LED elements are arranged. This LED substrate is positioned to be fitted into a transparent resin plate that forms the brush surface 31 (see Figure 5). As a result, the light emitted from the LED elements passes through the transparent resin plate and is irradiated from the brush surface 31.

[0026] LED35 is controlled to light up, for example, when the electric toothbrush 1 is in operation. This allows the user to brightly illuminate the inside of their mouth (especially the molar areas on both sides) when brushing their teeth with the electric toothbrush 1, making it easier to see if their teeth are being brushed properly.

[0027] LED35 may be composed of multiple LED elements that emit light in different colors. This allows the LED35 to emit light in different colors according to the operating mode of the electric toothbrush 1, thereby informing the user of the operating mode.

[0028] The head cover 33 is made of a relatively soft material (for example, an elastic resin material, a soft rubber material, or a silicone material). This reduces damage to the teeth caused by vibrations of the head portion 21 of the electric toothbrush 1 while it is in operation. The head cover 33 may also be made of a transparent material. This allows the light from the LED 35 to be emitted from the entire head portion 21, not just the brush surface 31, to the outside.

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

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

[0031] The base member 41 has a bottom surface 42, a column 43, an insertion hole 44, and a wiring path 45. The bottom surface 42 forms the bottom surface of the brush part 20. As shown in Figure 6, with the brush part 20 attached to the main body part 10, the bottom surface 42 is close to the top surface 10b of the main body part 10.

[0032] The bottom surface 42 is provided with two protrusions 47. The two protrusions 47, 47 are positioned opposite each other (i.e., at approximately 180 degrees) on the outer edge of the upper surface of the roughly circular bottom surface 42.

[0033] The column 43 is a columnar portion that extends from the base portion 42 toward the head portion 21. The column 43 is fitted into the hollow portion on the lower side (Y2 side) of the main body portion of the rod portion 22 (see Figure 5). An insertion hole 44 is formed inside the column 43. The insertion hole 44 is a hole that extends from the base portion 42 toward the upper side (Y1 side) inside the column 43.

[0034] The interlocking shaft 16 of the main body 10 is inserted into the insertion hole 44. With the interlocking shaft 16 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 Figure 6). In this way, when attaching the brush part 20 to the main body 10, they are connected in a position where their respective front sides (i.e., the brush surface 31 and the front part 10a) face the same direction.

[0035] The wiring path 45 has a groove extending vertically (Y direction) on the outer surface of the column 43. Wiring 53 extending from the receiving coil 52 to the LED 35 is arranged in this groove of the wiring path 45. In Figure 6, the wiring 53 is shown as a dashed line. The wiring path 45 has, from top to bottom along the direction of extension of the groove, a wiring hole 45a, a first inclined section 45b, a vertical section 45c, and a second inclined section 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. The provision of such an elastic joint portion 46 makes it easier for the user to insert the interlocking shaft 16 when attaching the brush portion 20. In addition, the provision of the elastic joint portion 46 allows the interlocking shaft 16 to be fitted more tightly into the insertion hole 44. This allows the rotational force of the motor 13 to be transmitted to the brush portion 20 more reliably.

[0037] A receiving coil (non-contact receiving unit) 52 is installed on the base member 41 to receive electrical signals (power) from the battery 14 in the main body 10. The electrical signals received by the receiving coil 52 are 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 suitable for fixing the receiving coil 52 within the rod portion 22 (specifically, the bottom surface portion 42, the column 43, the projection 47, the stopper ring 26, etc.).

[0039] (Regarding power supply to LEDs) Next, we will explain how to supply power to the LED 35 of the brush section 20. In the case of the electric toothbrush 1 according to this embodiment, where the main body 10 and the brush section 20 are made of separate parts, it is difficult to supply a stable power source from the main body 10 to the brush section 20, which vibrates at a high frequency. Another option is to incorporate a power source for the LED 35, such as a battery, into the brush section 20, but this would increase the size of the brush section 20, making it difficult to brush one's teeth.

[0040] In this embodiment of the electric toothbrush 1, the principle of wireless sensitive charging is employed, and power is supplied from a transmitting coil (non-contact transmitting unit) 51 located at the top (Y1 side) of the main body 10 to a receiving coil (non-contact receiving unit) 52 located at the bottom (Y2 side) of the brush unit 20. When the transmitting coil 51 in the main body 10 transmits electromagnetic waves upward, the receiving coil 52 on the brush unit 20 side receives them and generates power. This power is then supplied to the LED 35 of the head unit 21 through wiring 53 located inside the brush unit 20. As a result, the LED 35 can light up.

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

[0042] The receiving coil 52 is positioned close to the bottom surface 42 of the brush section 20 (see Figure 6). In one example, the receiving coil 52 has an annular shape and is positioned to surround the column 43 (see Figure 8). The transmitting coil 51 is a wireless sensitive receiving end and receives electrical signals (electromagnetic waves) transmitted from the transmitting coil 51. The electrical signals received by the receiving coil 52 are converted into power. The converted power is supplied through the wiring 53 to the LED 35 (specifically, the LED substrate) provided in the head section 21.

[0043] With the above configuration, stable power can be supplied between the non-contact brush section 20 and the main body section 10. Therefore, the LED 35 can be lit using power from the battery 14 inside the main body section 10.

[0044] Furthermore, in the electric toothbrush 1 according to this embodiment, the motor 13 can operate the brush section 20 with a larger amplitude of oscillation, which makes it easy for misalignment to occur in the receiving coil 52 within the brush section 20. Therefore, the electric toothbrush 1 has a configuration for fixing the receiving coil 52 within the rod section 22.

[0045] Specifically, an annular receiving coil 52 is arranged on the base member 41 so as to surround the column 43. Multiple (for example, two) protrusions 47 are provided on the outer circumference of the bottom surface 42 of the base member 41, and the inner and outer circumferences of the annular receiving coil 52 are supported by the protrusions 47 and the column 43. This makes it possible to suppress the movement of the receiving coil 52 in the left-right direction (X direction) and the front-back direction (Z direction) (i.e., horizontal movement).

[0046] Furthermore, an annular stopper ring 26 is positioned above the annular receiving coil 52 (see Figure 6). As a result, the receiving coil 52 is sandwiched between the stopper ring 26 and the bottom surface 42, restricting its vertical space. This suppresses the vertical movement (Y direction) of the receiving coil 52.

[0047] With the above configuration, the receiving coil 52 can be securely fixed around and above and below, enabling a stable power supply to the operating brush section 20. As a result, the LED 35 can be illuminated stably even under strong vibration conditions.

[0048] As described above, the rod portion 22 and the base member 41 have a configuration suitable for fixing the receiving coil 52 within the rod portion 22 (specifically, the bottom portion 42, the column 43, the projection 47, the stopper ring 26, etc.). This allows for a stable power supply even when the brush portion 20 is vibrating (operating), and stabilizes the lighting state of the LED 35.

[0049] (Motor configuration) Next, we will describe the more detailed configuration of the motor 13. Figure 9 shows the external configuration of the motor 13. Figure 10 shows the internal configuration of the motor 13. Figure 11(a) shows a schematic configuration of the cross-section (cross-section perpendicular to the axis of rotation) of the motor 13.

[0050] In one example, motor 13 is a brushless motor. By using a brushless motor as motor 13, the torque can be increased by a strong magnetic force, thereby achieving a stronger brushing force in the operation of the head unit 21. For example, by using a 7.4-volt brushless motor and a powerful magnet, it is possible to achieve more than twice the torque compared to a conventional ultrasonic motor.

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

[0052] The motor case 61 houses various components such as the rotating shaft 62, magnet 63, coil 64, circular magnet 65, and sensor unit 66. The rotating shaft 62 extends vertically (Y direction) within the motor case 61. The upper end of the rotating shaft 62 (the end on the Y1 side) 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, causing the interlocking shaft 16 to vibrate (rotate) in a predetermined direction with its axis as a pivot point.

[0053] The magnet 63 is provided on the outer circumference of the rotating shaft 62. The magnet 63 has a north pole and a south pole. Multiple coils 64 are provided so as to surround the outer circumference of the magnet 63. In one example, six coils 64 are provided (see Figure 11(a)).

[0054] The circular magnet 65 and the sensor unit 66 are located on the lower end (Y2 side end) 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. The circular magnet 65 and the sensor unit 66 allow the position of the rotation axis 62 to be determined.

[0055] Specifically, the sensor unit 66 can determine the position (rotation angle) of the rotating shaft 62 by identifying the position of the circular magnet 65 attached to the lower end of the rotating shaft 62. The position of the circular magnet 65 and the position of the head unit 21, which is attached via the interlocking shaft 16, are arranged in a corresponding manner.

[0056] The position information of the rotating shaft 62 detected by the sensor unit 66 is transmitted to the control circuit in the control board 15. Based on the transmitted position information, the control circuit can adjust the rotation angle of the head unit 21 in real time (see Figure 11(b)). This enables precise control of the operation of the head unit 21.

[0057] (Method for controlling the vibration of the brush section) Next, we will explain the method for controlling the vibration of the brush section 20 in the electric toothbrush 1.

[0058] Conventional ultrasonic vibrating electric toothbrushes generate a regularly changing magnetic field through electromagnetic induction, and use the interaction between the magnet inside the motor and the magnetic force to cause the rotating shaft to rotate (vibrate) regularly. In this case, the rotation angle is approximately 2 degrees to the left and right. 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 approximately 250 Hz (see Figure 15), and periodic changes in the direction of the current occur approximately 250 times per second. As a result, approximately 15,000 (250 x 60) reciprocating motions occur per minute, achieving high-frequency brushing action.

[0059] In the electric toothbrush 1 according to this embodiment, a low-frequency electrical control method is added in addition to the high-frequency vibration of a conventional ultrasonic motor. That is, high-frequency and low-frequency signals are superimposed and applied to the motor 13. This makes it possible to achieve not only vibration of the brush part 20 at a narrow angle (for example, about 2 to 5 degrees) but also sweeping motion of the brush part 20 at a wide angle (for example, about 10 to 30 degrees) (see Figure 11(b)).

[0060] Figure 12 shows the frequencies of the currents input to motor 13. The currents input to motor 13 include two types: a high-frequency current H and a low-frequency current L. In the waveform diagram shown in Figure 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 a high-frequency current H is input to the motor 13, it performs a reciprocating motion approximately 250 times per second, similar to a conventional electric toothbrush (see Figure 15), thereby achieving high-frequency brushing. Furthermore, when a low-frequency current L is input to the motor 13, two perfect sine waves are generated per second, resulting in a reciprocating motion of, for example, two times per second.

[0062] When these two types of waveforms overlap, a complex waveform is generated, as shown in Figure 13. This waveform is generated by the simultaneous action of high-frequency oscillations (approximately 250 Hz) and low-frequency sweeps (approximately 1 Hz), resulting in a waveform structure in which two currents are superimposed. Due to the combination of high and low frequencies, the waveform exhibits characteristics of both small-amplitude high-frequency oscillations and large-amplitude low-frequency sweeps.

[0063] In this embodiment, the electric toothbrush 1 exhibits the operation waveform shown in Figure 13, allowing the head unit 21 to maintain fine high-frequency vibrations while simultaneously achieving wide-ranging sweeping motions at large angles. This significantly improves the cleaning effect of brushing teeth when using the electric toothbrush 1.

[0064] The frequency of the high-frequency current H is, for example, within the range of 50 Hz to 600 Hz. The frequency of the low-frequency current L is, for example, within the range of 0.5 Hz to 50 Hz.

[0065] Furthermore, by employing a low-frequency electrical control system, the head unit 21 does not move symmetrically from side to side, but is deflected in one direction. This deflection of the head unit 21 in one direction enables brushing at a wide angle (see Figure 11(b)).

[0066] Alternatively, the sensor unit 66 may recognize the magnetic field output by the circular magnet 65 attached to the rotating shaft 62, and the sensor unit 66 may output the current position of the head unit 21. This allows the brush unit 20 to be deflected at a large angle, and then deflected in the opposite direction once a specific angle is reached. By fine-tuning the rotation angle using the sensor unit 66 in this way, the head unit 21 can perform low-frequency reciprocating motion within a set large-angle range.

[0067] (Method for controlling the rotation angle of the brush part) Next, we will explain how to control the rotation angle of the brush part 20 in the electric toothbrush 1.

[0068] In the electric toothbrush 1 according to this embodiment, a sensor unit 66 provided on the motor 13 detects the current position of the head unit 21, thereby enabling control of 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, located at the lower end (Y2 side end) of the motor 13, has a north pole and a south pole. The magnetic field generated by this circular magnet 65 acts on the sensor unit 66 located below the circular magnet 65 (on the Y2 side).

[0070] As described above, the position of the rotating shaft 62 to which the circular magnet 65 is attached and the position of the head portion 21 are arranged in correspondence with each other. Therefore, if 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 portion 21 can also be determined.

[0071] When the rotation axis 62 rotates at different angles, the magnetic force at specific points within the magnetic field's range of action differs. Based on this fundamental principle, the position of the rotation axis 62 is identified using two sensor elements 66a and 66b within the sensor unit 66. Different magnetic fields formed at different angles act on the two sensor elements 66a and 66b located at different positions, generating magnetic flux data that uniquely corresponds to angles from 1 to 360 degrees.

[0072] Here, we define the magnetic flux density value measured by the first sensor element 66a as b1, and the magnetic flux density value measured by the second sensor element 66b as b2. Due to the different magnetic flux densities, each sensor element 66a and 66b outputs a different voltage (see Figure 14). This is based on the principle that the direction and strength of the magnetic field affect the direction and strength of the current, and the change in voltage can be derived by an algorithm. Since the rotation axis 62 changes along a 360-degree circumference, the change in voltage exhibits a sinusoidal shape.

[0073] As the two sensor elements 66a and 66b perform measurements simultaneously, two sinusoidal curves are generated, as shown in Figure 14. These sinusoidal curves are processed by an algorithm to obtain a unique solution for angles from 1 to 360 degrees. Using this unique solution, the current position of the rotation axis 62 can be accurately measured.

[0074] The specific calculation formula (a function calculation representing the ratio of magnetic flux 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. b1 is the magnetic flux density value 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 the case.

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

[0076] Based on the above, the control circuit in the control board 15 uses an electrical control program to adjust the current and frequency applied to the multiple 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 precisely controlled.

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

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

[0079] With the above configuration, power from the battery in the main unit can be supplied to the LED located in the head unit by utilizing the principle of wireless sensitive charging. Therefore, in an electric toothbrush with a removable brush head, the LED can be kept lit stably even when the head unit is in operation.

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

[0081] With the above configuration, the presence of the base member suppresses vibration of the non-contact receiving unit within the brush section during operation. Therefore, even in the case of an electric toothbrush with a motor capable of performing powerful swing vibrations, for example, power can be stably supplied to the LED provided in the head section.

[0082] In an electric toothbrush according to one 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] With the above configuration, horizontal shaking and vibration of the non-contact receiving unit can be suppressed within the operating brush section. Therefore, even in the case of an electric toothbrush with a motor capable of powerful swinging vibrations, for example, power can be stably supplied to the LED located in the head section.

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

[0085] With the above configuration, the head of the electric toothbrush, while in operation, can perform fine vibrations using high-frequency signals while also performing wide-angle sweeping movements using low-frequency signals. This significantly improves the cleaning effect of brushing teeth when using an electric toothbrush.

[0086] In an electric toothbrush according to one aspect of the present invention (for example, electric toothbrush 1), a circular magnet (for example, circular magnet 65) and a sensor unit (for example, sensor unit 66) for detecting the position of the circular magnet may be provided at one end of the motor (for example, motor 13) in the axial direction (for example, the end furthest from the head unit 21).

[0087] With the above configuration, the position of the motor's rotation axis, to which the circular magnet is attached, can be determined by the sensor unit. This allows the rotation angle of the electric toothbrush head to be changed within a set range during operation. Therefore, the head can be operated at a rotation angle that suits the user's preference.

[0088] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope of the claims are intended to be included. Configurations obtained by combining the configurations of the different embodiments described herein are also included in the scope of the invention. [Explanation of symbols]

[0089] 1: Electric toothbrush 10: Main body 12:Operation unit 13: Motor 14:Battery 15: Control board 16: Interlocking shaft 20: Brush part 21: Head section 22: Rod section 31: Brush surface 32: Brush bristles 33: Headcover 35: LED 41: Base component 43: Column 44: Insertion hole 45: Wiring Route 47: Protrusion 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 containing a motor and battery, A brush portion that is detachable from the main body portion and An electric toothbrush equipped with, The aforementioned brush portion is A head section having brush bristles, The rod portion connected to the main body portion and It has, The end of the main body that connects to the brush section is provided with a non-contact transmitting unit that transmits electrical signals. The end of the rod portion that connects to the main body portion is provided with a non-contact receiving unit that receives the electrical signal from the non-contact transmitting unit. The head portion is provided with an LED that lights up in response to the electrical signal received by the non-contact receiving unit. Electric toothbrush.

2. A base member is provided at the end of the rod portion that connects to the main body portion, for fixing the non-contact receiving unit. The electric toothbrush according to claim 1.

3. The base member has a column extending toward the head portion, The non-contact receiving unit has an annular shape surrounding the columnar body. The electric toothbrush according to claim 2.

4. The main body is connected to the motor and has an interlocking shaft that transmits the driving force of the motor to the brush section. The rod portion is provided with an insertion hole into which the interlocking shaft is fitted. The motor is subjected to a superposition of high-frequency and low-frequency signals. An electric toothbrush according to any one of claims 1 to 3.

5. A circular magnet and a sensor unit for detecting the position of the circular magnet are provided at one end of the motor in the axial direction. The electric toothbrush according to claim 4.

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