JP2007301177A - Wireless power receiving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless power receiving apparatus reducing the transmission power and simplifying a power generator by constantly acquiring uniform incoming power even where the apparatus directs in any direction in a magnetic field generated unidirectionally. <P>SOLUTION: A capsule endoscope 100 having a receiving antenna 4 receiving a magnetic field and converting it into power in the interior 8i of an exterior case 8 is characterized in that the receiving antenna is rotationally disposed in the interior 8i of the exterior case 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wireless power receiving apparatus including a power receiving antenna that receives a magnetic field and converts it into electric power in an outer casing.

  2. Description of the Related Art As is well known, an endoscope having a tubular elongated insertion portion having an image pickup device or the like at the tip and an operation portion connected to the insertion portion, and an image processing apparatus connected to the endoscope In addition, an endoscope apparatus that has a display device and the like, can be observed and inspected by inserting an insertion portion into a body cavity of a subject and imaging the inside of the body cavity has been put into practical use. The endoscope of such an endoscope apparatus has a limit in the range in which an operator can perform observation, inspection, and the like because there are restrictions on the thickness and length of the insertion portion inserted into the body cavity. It was.

  In view of such circumstances, for example, a so-called capsule endoscope has been developed in recent years, which is a wireless power receiving device that incorporates an imaging device having a photographing optical system inside a tablet capsule-shaped exterior housing. ing.

  The capsule endoscope is introduced into a body cavity by means such as a subject swallowing the capsule endoscope, and proceeds inside the body cavity by, for example, intestinal peristalsis, and images an affected area of an organ in the body cavity by an imaging device. The endoscope image is stored in a memory or wirelessly transmitted to an external receiver.

  In the case of wireless communication, the endoscope image transmitted from the capsule endoscope is received outside the body, and on the other hand, when the endoscope image is stored in the memory, the capsule endoscope discharged from the body By taking out this memory, the operator can easily observe the endoscopic image, and thus can easily observe and examine the body cavity.

  As described above, when a capsule endoscope is used for examination in a body cavity, it is difficult to perform observation or examination with a conventional endoscope having a long and thin insertion portion, for example, observation of an organ such as a small intestine. And inspection can be performed relatively easily.

  By the way, the power source of the capsule endoscope described above is generally one using a battery built in the capsule endoscope. However, an AC magnetic field (hereinafter referred to as an external magnetic field) generated by a power signal generator outside the body is used. Also known is a configuration in which the power is converted into electric power by a rectifier circuit of a power receiving antenna provided in the capsule endoscope introduced into the body and used as a power source of the capsule endoscope. It is.

  The external magnetic field generated outside the body is generally a magnetic field that generates a magnetic flux in a direction perpendicular to the ground surface. Further, when the power receiving antenna is directed in the same direction as the external magnetic field generated in the vertical direction, that is, in a direction parallel to the external magnetic field, the power receiving antenna easily receives the external magnetic field.

  Here, since the capsule endoscope travels in the body cavity, the posture of the capsule endoscope varies depending on the shape of the organ in the traveling body cavity. Therefore, in the configuration of the capsule endoscope that receives power from the external magnetic field generated outside the body, depending on the relationship between the external magnetic field outside the body and the direction of the capsule endoscope that travels in the body cavity, that is, the direction of the power receiving antenna, In addition to the fact that the power receiving efficiency may be significantly lowered, there is a problem that electric power cannot be obtained.

  In view of such a problem, as shown in FIG. 9, in Patent Document 1, a core 26 composed of an energy storage component such as a capacitor or a rectifier circuit is configured to receive energy from an external energy source. There has been proposed an energy power receiving unit 500 that functions as a power receiving antenna having a configuration in which axial coils 28 (28Lx, 28Ly, 28Lz) are wound so as to cross each other by 90 °. In addition, FIG. 9 is a perspective view which shows the outline of the external appearance of the conventional energy receiving unit.

  Specifically, as shown in FIG. 10, the energy receiving unit 500 includes three orthogonal coils 28Lx, 28Ly, 28Lz for converting a time-varying external magnetic field into an alternating current, and the three coils 28Lx, 28Ly, The main part is constituted by three diode bridges 29Bx, 29By, 29Bz for rectifying the converted alternating current by 28Lz, and a capacitor 30 functioning as an energy storage and ripple attenuation element. In addition, FIG. 10 is a figure which shows the outline of a structure of the electric circuit of the conventional energy receiving unit.

Therefore, if the capsule endoscope has the energy receiving unit 500 having such a configuration, a power receiving antenna and an external magnetic field generated in a direction perpendicular to the ground surface, which is a fixed direction, can be detected in the body cavity. Even if the energy receiving unit 500 is oriented in any direction, any one of the three coils 28Lx, 28Ly, and 28Lz is inclined at most 45 ° with respect to the external magnetic field. The power reception efficiency is not lowered below a certain value when power is received when the coil is shifted by 45 ° with respect to the external magnetic field.
JP-T-2004-528890

  However, in the energy receiving unit 500 disclosed in Patent Document 1, any one of the three coils 28Lx, 28Ly, and 28Lz is tilted with respect to the direction of the external magnetic field outside the body according to the inclination of the capsule endoscope. If the direction of the coil is tilted by 45 °, only about half of the power can be received.

  Therefore, when the energy receiving unit 500 is provided in a capsule endoscope that moves through the body cavity while changing its posture, the energy receiving unit 500 receives power most efficiently from an external magnetic field outside the body depending on the shape of the organ. It is not always possible to obtain a constant received power that is ½ or more of the case.

  In such a case, in order to always obtain the constant power most efficiently, it is necessary to increase the transmission power of the signal generator for power outside the body or to control the transmission power according to the posture of the capsule endoscope. In addition to the increase in transmission power, there is a problem that transmission power control becomes complicated.

  The present invention has been made in view of the above problems, and always obtains uniform received power without degrading the power receiving efficiency, regardless of the direction of the device in a magnetic field generated in a certain direction. Accordingly, an object of the present invention is to provide a wireless power receiving apparatus that can realize reduction in transmission power and simplification of a power generation apparatus.

  In order to achieve the above object, a wireless power receiving apparatus according to the present invention is a wireless power receiving apparatus having a receiving antenna that converts a magnetic field into electric power in an outer casing, wherein the receiving antenna is rotated in the outer casing. It is arranged to be movable.

  According to the present invention, it is possible to reduce power consumption and generate power by always obtaining uniform received power without reducing power receiving efficiency, regardless of the direction of the device in a magnetic field generated in a certain direction. It is possible to provide a wireless power receiving apparatus that can achieve simplification of the above.

  Embodiments of the present invention will be described below with reference to the drawings. In the embodiment described below, the wireless power receiving apparatus will be described by taking a capsule endoscope as an example.

(First embodiment)
FIG. 1 is a view showing a state where a capsule endoscope showing a first embodiment of the present invention is introduced into a body cavity, and FIG. 2 is a cross-sectional view of the capsule endoscope taken along line II-II in FIG. 3 and 3 are cross-sectional views of the capsule endoscope taken along line III-III in FIG.

  In FIGS. 2 and 3, other components such as a known light source, an imaging optical system, an imaging device, and an electronic control component that are included in the capsule endoscope are not shown for the sake of simplicity.

  As shown in FIG. 1, a capsule endoscope 100 is introduced into a body cavity when the capsule endoscope 100 is swallowed by a subject, and has an external appearance of a capsule tablet shape. is doing.

  In the inside 8i of the outer casing 8 made of resin, for example, of the capsule endoscope 100, the power receiving unit 3 is in the second axis direction in FIG. 2 and FIG. In the direction, the second pivot shaft 2 is pivotally supported so as to be pivotable in the y1 direction or the y2 direction.

  Note that the second rotating shaft 2 may or may not rotate with the power receiving unit 3 in the y1 direction or the y2 direction. Moreover, the 2nd rotating shaft 2 is comprised from the electroconductive member.

  The power receiving unit 3 includes, for example, a hollow spherical housing 20, a power receiving antenna 4, a first rotation shaft 1 orthogonal to the second rotation shaft 2, and a weight 5, and main parts are configured. . Specifically, in the inside 20i of the casing 20, the power receiving antenna 4 is in the x1 direction or the x axis direction, which is the first axis direction orthogonal to the y axis direction in FIGS. The first pivot shaft 1 is pivotally supported so as to be pivotable in the x2 direction.

  Further, a weight 5 is fixed to a part of the outer periphery of the housing 20 as shown in FIG. The first rotation shaft 1 may or may not rotate with the power receiving antenna 4 in the x1 direction or the x2 direction. Moreover, the 1st rotating shaft 1 is comprised from the electroconductive member.

  The power receiving antenna 4 includes a magnetic core 17 having, for example, a short column shape, and a coil 7 wound around the outer periphery of the magnetic core 17 in, for example, the y1 direction or the y2 direction. Also, a weight 6 is fixed to a part of the outer periphery of the magnetic core 17 as shown in FIGS.

  The power receiving antenna 4 receives the external magnetic field generated by the power signal generator outside the body in a wireless state. More specifically, the power receiving antenna 4 is a solenoid type antenna formed of a coil, and a core material made of a magnetic material is disposed inside the coil. The coil 7 converts a time-varying external magnetic field into an alternating current, and the magnetic core 17 corresponds to a core material made of a magnetic material such as cobalt, amorphous, ferrite, or a compound thereof. The coil 7 efficiently collects a large amount of magnetic flux. The alternating current converted by the coil 7 is converted into electric power and becomes a power source of the capsule endoscope 100.

Note that the actual power conversion requires a rectifier circuit such as a diode bridge that rectifies an alternating current, and a smoothing circuit such as a capacitor that functions as an energy storage element and a ripple attenuation element. Therefore, the description and illustration are omitted here.
Next, the effect | action of this Embodiment comprised in this way is demonstrated using FIGS. 1-3, and FIG. 4 mentioned above. FIG. 4 is a cross-sectional view of the capsule endoscope showing a state where the power receiving unit and the power receiving antenna are always directed in the direction of gravity by the weights in FIG. 3.

  First, in order to supply power to the capsule endoscope 100, an external magnetic field is generated by an external power signal generator. As shown in FIG. 1, the external magnetic field is generated by the power signal generator so that the magnetic flux M is generated in the direction perpendicular to the ground surface.

  Further, as shown in FIG. 1, the signal generator for power assumes a known Helmholtz-type coil 15 that is covered circumferentially at, for example, two locations as shown in FIG. 1. The power signal generator for generating an external magnetic field is not limited to a Helmholtz type coil, and may be a solenoid type coil or another coil.

  Thereafter, when the subject swallows the capsule endoscope 100 in a magnetic field as shown in FIG. 1, the capsule endoscope 100 is introduced into the body cavity, for example, into the digestive tract by the movement of the intestines. Move along.

  As a result, the capsule endoscope 100 moves while changing in any posture by moving in a complicated organ. In other words, the capsule endoscope 100 advances in the body cavity while pointing in any direction while changing the posture every moment, not in a fixed direction.

  At this time, regardless of the posture of the capsule endoscope 100, the power receiving antenna 4 is rotated in the x1 direction or the x2 direction by the action of the first rotating shaft 1 and the weight 6 as shown in FIG. The weight 6 approaches the ground surface and is always directed downward G in the direction of gravity, that is, directed in a direction parallel to the magnetic flux M, and always maintains a vertical posture with respect to the ground surface.

  In substantially the same manner, regardless of the posture of the capsule endoscope 100, the power receiving unit 3 is operated in the y1 direction or the y2 direction by the action of the second rotating shaft 2 and the weight 5, as shown in FIG. , The weight 5 approaches the ground surface and is always directed downward in the direction of gravity, that is, directed in a direction parallel to the magnetic flux M, and always maintains a posture perpendicular to the ground surface.

  Therefore, in the capsule endoscope 100 that travels in the body cavity, the power receiving antenna 4 rotates in the y1 direction or y2 direction of the power receiving unit 3 and the x1 direction of the power receiving antenna 4 regardless of the posture of the capsule endoscope 100. Always maintain a vertical posture with respect to the ground surface by rotating in the x2 direction.

  As described above, in the present embodiment, the power receiving unit 3 that is rotatable in the y1 direction or the y2 direction with respect to the outer casing 8 is disposed in the inside 8i of the outer casing 8 of the capsule endoscope 100. The power receiving antenna 4 that is rotatable in the x1 direction or the x2 direction with respect to the housing 20 is disposed in the inside 20i of the housing 20 of the power receiving unit 3. It is shown that weights 5 and 6 are fixed to each part of the antenna 4.

  According to this, when the capsule endoscope 100 advances in the body cavity, the power receiving antenna 4 rotates and receives power in the y1 direction or the y2 direction of the power receiving unit 3 regardless of the posture of the capsule endoscope 100. By rotating the antenna 4 in the x1 direction or the x2 direction, the posture perpendicular to the ground surface is always maintained, so that the external magnetic field of the magnetic flux M generated in the direction perpendicular to the ground surface can be collected most efficiently. Regardless of the posture of the capsule endoscope 100, uniform received power can be obtained from outside the body.

  For this reason, the power receiving antenna 4 can always receive power efficiently with constant received power. Therefore, it is not necessary to increase the transmission power of the signal generator for power outside the body as the received power decreases, and it is not necessary to control the transmission power according to the posture of the capsule endoscope. Simplification and low power consumption can be realized. Therefore, since the power can be efficiently received from outside the body, the capsule endoscope 100 with stable operation can be obtained.

  In addition, the power receiving unit 3 and the power receiving antenna 4 are rotatable in the interior 8i of the outer casing 8 regardless of the direction of the capsule endoscope 100, and therefore, compared with the case where the capsule endoscope 100 itself rotates. As the power receiving unit 3 and the power receiving antenna 4 rotate, the power receiving unit 3 and the power receiving antenna 4 do not come into contact with the internal tissue in the body cavity and cause friction.

  Therefore, even when the capsule endoscope 100 travels through the sandwiched portion in the body cavity, the posture of the power receiving antenna 4 can be maintained perpendicularly with respect to the ground surface at all times. That is, regardless of the built-in shape, the posture of the power receiving antenna 4 can be maintained perpendicularly with respect to the ground surface at all times.

(Second Embodiment)
FIG. 5 is a cross-sectional view schematically illustrating a capsule endoscope showing a second embodiment of the present invention from the front, and FIG. 6 is a cross-sectional view schematically illustrating the capsule endoscope of FIG. 5 from the side. is there.

  In the present embodiment, the wireless power receiving apparatus will be described by taking a capsule endoscope as an example. 5 and 6, other components such as a known light source, an imaging optical system, an imaging element, and an electronic control component that the capsule endoscope has are not shown for the sake of simplicity.

  Compared with the capsule endoscope shown in FIGS. 1 to 4, the configuration of the capsule endoscope of the second embodiment is such that the posture of the power receiving antenna is set with respect to the ground surface without using the power receiving unit. The difference is that it is kept vertical. Therefore, only this difference will be described, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted.

  Also in the present embodiment, the power receiving antenna 4 is a solenoid type antenna formed by a coil, and a core material made of a magnetic material is disposed inside the coil. The coil 7 converts a time-varying external magnetic field into an alternating current, and the magnetic core 17 corresponds to a core material made of a magnetic material such as cobalt, amorphous, ferrite, or a compound thereof. The coil 7 efficiently collects a large amount of magnetic flux. The alternating current converted by the coil 7 is converted into electric power and becomes a power source of the capsule endoscope 200 of the present embodiment.

In addition, actual power conversion requires a rectifier circuit such as a diode bridge that rectifies alternating current and a smoothing circuit such as a capacitor that functions as an energy storage element and a ripple attenuation element. These are generally used. In the present embodiment, both the description and illustration are omitted.
In the inside 208 i of the outer casing 208 made of, for example, resin of the capsule endoscope 200, the power receiving antenna 4 is in the x-axis which is the first axial direction in FIGS. 5 and 6 with respect to the outer casing 208. In the direction, it is pivotally supported by the third rotation shaft 201 so as to be rotatable in the x1 direction or the x2 direction.

  Further, the weight 6 is fixed to a part of the magnetic core 17 of the power receiving antenna 4 as described above. Note that the third rotation shaft 201 may or may not rotate with the power receiving antenna 4. Moreover, the rotating shaft 201 is comprised from the electroconductive member.

  Further, as shown in FIGS. 5 and 6, a weight 205 is fixed to the inner peripheral surface of the exterior casing 208 along the longitudinal direction of the capsule endoscope 200.

  Next, the effect | action of this Embodiment comprised in this way is demonstrated using FIG. 5, FIG. 6 mentioned above. It should be noted that operations similar to those of the first embodiment described above are omitted.

  First, when the subject swallows the capsule endoscope 200 in a magnetic field in which a magnetic flux M is generated in a direction perpendicular to the ground surface as shown in FIG. It is introduced into the body cavity and moves along the digestive tract.

  As a result, the capsule endoscope 200 moves while changing in any posture by moving in a complicated organ. That is, the capsule endoscope 200 advances in the body cavity while pointing in any direction while changing the posture every moment, not in a fixed direction.

  At this time, the capsule endoscope 200 travels in the organ while pointing in any direction, but the capsule endoscope 200 moves inside the organ so that the weight 5 is always pulled in the direction of gravity by the weight 205. As shown in FIG. 5, by rotating in the y1 direction or the y2 direction, the posture of the capsule endoscope 200 is maintained at the lowest position in the gravitational direction as the weight 205 approaches the ground surface. Thus, the posture is controlled by the weight 205.

  Regardless of the posture of the capsule endoscope 200, the power receiving antenna 4 is rotated in the x1 direction or the x2 direction by the action of the rotating shaft 201 and the weight 6 as shown in FIGS. The weight 6 is always directed downward in the direction of gravity, that is, directed in a direction parallel to the magnetic flux M, and always maintains a posture perpendicular to the ground surface.

  Therefore, in the capsule endoscope 200 traveling in the body cavity, the power receiving antenna 4 rotates in the y1 direction or the y2 direction of the capsule endoscope 200 and the power receiving antenna 4 regardless of the posture of the capsule endoscope 200. A posture perpendicular to the ground surface is always maintained by rotation in the x1 direction or the x2 direction.

  As described above, in the present embodiment, the power receiving antenna 4 that is rotatable in the x1 direction and the x2 direction with respect to the exterior casing 208 is disposed in the interior 208i of the exterior casing 208 of the capsule endoscope 200. In addition, the weights 205 and 6 are shown to be fixed to the exterior casing 208 and a part of the power receiving antenna 4.

  According to this, when the capsule endoscope 200 advances in the body cavity, the weight 205 is always positioned at the lowest position by the weight 205 even if the capsule endoscope 200 tries to direct the posture in multiple directions. The posture of the capsule endoscope 200 is controlled, and the power receiving antenna 4 always maintains a posture perpendicular to the ground surface by the rotation of the power receiving antenna 4 in the x1 direction or the x2 direction. Since the external magnetic field of the magnetic flux M generated in the vertical direction can be collected most efficiently, uniform received power can be obtained from outside the body.

  For this reason, the power receiving antenna 4 can always receive power efficiently with constant received power. Therefore, it is not necessary to increase the transmission power of the signal generator for power outside the body as the received power decreases, and it is not necessary to control the transmission power according to the posture of the capsule endoscope 200. Simplification of the apparatus and reduction in power can be realized. Therefore, since the power can be efficiently received from outside the body, the capsule endoscope 200 with stable operation can be obtained.

  In the present embodiment, the weight 205 is fixed to the inner peripheral surface of the outer casing 208 in order to control the posture of the capsule endoscope 200. However, the present invention is not limited to this, and the posture of the power receiving antenna 4 is not limited thereto. Of course, the weight 205 does not need to be fixed to the exterior casing 208 as long as it is maintained perpendicular to the ground surface.

  Here, in the first embodiment described above, both ends of the coil 7 serving as the electrode of the power receiving antenna 4 are electrically connected to the first rotating shaft 1 and the power receiving unit 3 by wiring or the like. The power receiving unit 3 is also electrically connected to the second rotating shaft 2 by wiring or the like.

  In the second embodiment described above, both ends of the coil 7 of the power receiving antenna 4 are electrically connected to the third rotating shaft 201 by wiring or the like.

  By the way, in 1st Embodiment mentioned above, it showed that the power receiving antenna 4 rotated in the inside 20i of the housing | casing 20 of the power receiving unit 3, and the power receiving unit 3 rotated in the inside 8i of the exterior housing | casing 8. FIG. . In the second embodiment, the power receiving antenna 4 is shown to rotate in the interior 208 i of the exterior casing 208.

  Therefore, in the first embodiment described above, as the power receiving antenna 4 or the power receiving unit 3 is rotated, the wirings are entangled or twisted in the interiors 20i, 8i of the housings 20, 8. As a result, the electrical continuity may become unstable.

  Also in the second embodiment described above, each wire becomes entangled or twisted in the interior 208i of the exterior housing 208 as the power receiving antenna 4 rotates, and the electrical continuity is unstable. There was a case where it became.

  Thus, hereinafter, with reference to FIG. 7, the capsule endoscope 200 of the first embodiment described above is taken as an example, for example, both ends of the coil 7 serving as an electrode of the power receiving antenna 4, and the first rotation shaft 1. An electrical conduction method will be described. FIG. 7 is a partial cross-sectional view showing a modification of the configuration of a part of the housing of the power receiving unit of FIG. 1 and the first rotation shaft.

  The first rotating shaft 1 shown in FIG. 2 described in the first embodiment is configured such that the needle-like electrode 301 also functions as the first rotating shaft 1 in FIG. . Therefore, the needle-shaped electrode 301 is rotatable with the power receiving antenna 4 in the x1 direction or the x2 direction.

  Further, on the inner peripheral surface of the spherical housing 20 of the power receiving unit 3, an electrode 311 that is always in contact with the needle-like electrode 301 is formed in an annular shape. Further, a wiring is extended from the electrode 311 along the inner peripheral surface or the outer peripheral surface of the housing 20. When the wiring is connected to the second rotating shaft 2, the electrode 311 is connected to the second rotating shaft 2. Is connected to the rotating shaft 2. In this case, the second rotating shaft 2 is rotatable together with the power receiving unit.

  That is, the first rotating shaft 1 and the second rotating shaft 2 are configured to also serve as the electrode of the power receiving antenna 4 or the power receiving unit 3.

  According to such a configuration, both ends of the coil 7 and the first electrode serving as a stable electrode of the power receiving antenna 4 and the first power without being restricted by twisting and entanglement of the wiring from the power receiving antenna 4 or the power receiving unit 3 that freely rotates. The electrical connection between the rotating shaft 1 and the power receiving unit 3 can be realized, and the power receiving unit 3 can realize the electrical connection with the second rotating shaft 2.

  The above can also be applied to the second embodiment. In this case, the needle-like electrode 301 is also configured to serve as the third rotation shaft 201, and the electrode 311 that is always in contact with the third rotation shaft 201 is annularly formed on the inner peripheral surface of the exterior casing 208. Form. That is, the third rotating shaft 201 is configured to also serve as the electrode of the power receiving antenna 4.

  According to such a configuration, as in the first embodiment described above, the coil 7 serving as a stable electrode of the power receiving antenna 4 can be obtained without being restricted by twisting or entanglement in the wiring from the power receiving antenna 4 that rotates freely. Electrical conduction between both ends and the second rotation shaft 2 can be realized.

  In the following, an electrical conduction method between both ends of the coil 7 of the other power receiving antenna 4 and the first rotating shaft 1 and the second rotating shaft 2 will be described with reference to FIG. FIG. 8 is a cross-sectional view of a capsule endoscope showing a modification of the shape of the power receiving unit of FIG.

  As shown in FIG. 8, for example, the cross-sectional shape is a triangular shape on two opposite surfaces of the power receiving antenna 4, for example, two sides that are diagonally separated from the x-axis direction on the upper and lower surfaces in the y-axis direction in FIG. 8. Each of the coil electrodes 12 is formed as a protruding rail-type protruding electrode. Each coil electrode 12 is connected to both ends of the coil 7 of the power receiving antenna 4 via wiring 9.

  Further, two opposite sides of the power receiving antenna 4, for example, two sides that are diagonally separated with respect to the x-axis direction other than the position where the coil electrode 12 is formed on the upper and lower surfaces in the y-axis direction in FIG. Protrusion-type rail-like dummy electrodes 13 having a triangular cross-sectional shape are formed.

  The dummy electrode 13 is an electrode having substantially the same size as the coil electrode 12 and is formed to promote smooth rotation in the x1 direction or the x2 direction in the inside 20i of the housing 20 of the power receiving antenna 4. ing.

  An annular rail electrode 14 is formed on the inner peripheral surface of the housing 20 at a position where the coil electrode 12 and the dummy electrode 13 are always in contact.

  That is, the electrode of the power receiving antenna 4 includes the coil electrode 12 and the rail electrode 14.

  According to such a configuration, both ends of the coil 7 of the stable power receiving antenna 4 and the first rotation shaft can be obtained without being restricted by twisting or entanglement in the wiring from the power receiving antenna 4 or the power receiving unit 3 that freely rotates. Electrical continuity with the first and second rotating shafts 2 can be realized.

  In the first and second embodiments described above, the wireless power receiving apparatus has been described by taking a capsule endoscope as an example. However, the present invention is not limited to this, and power to be a power source is generated from an external magnetic field. As long as it is a receiving device, it may be applied to any device.

[Appendix]
As described above in detail, according to the embodiment of the present invention, the following configuration can be obtained. That is,
(1) A wireless power receiving apparatus including a power receiving antenna for receiving power transmitted wirelessly, wherein the power receiving antenna is rotatable.

  Thus, even when the orientation of the device fluctuates with respect to the direction of the external magnetic field, the transmission power of the power signal generator is controlled in order to obtain an angle at which power can be received most efficiently by rotating the power receiving antenna. It is always possible to obtain an efficient and constant received power without the need.

(2) The power receiving antenna has a first rotating shaft, and is supported by the casing by the first rotating shaft to form a power receiving unit, and the power receiving unit has a second rotating shaft. The wireless power receiving apparatus according to appendix 1, wherein the second rotating shaft is supported by an external housing of the apparatus, and the power receiving antenna and the power receiving unit include a weight at one end of the periphery.

  As a result, even when the orientation of the device fluctuates with respect to the direction of the external magnetic field, the power receiving antenna and the power receiving unit can be rotated with respect to the respective rotation shafts, and are arranged at one end in the rotational circulation direction. The weight is always kept perpendicular to the ground surface. By maintaining the direction of the external magnetic field in a direction perpendicular to the ground surface, it is possible to always obtain efficient and constant received power without controlling the transmission power from the power signal generator.

(3) The wireless power receiving apparatus according to appendix 1, wherein the power receiving antenna has a first rotating shaft, and is supported by the outer casing of the wireless power receiving apparatus by the first rotating shaft. apparatus.

  Thereby, even when the orientation of the device fluctuates with respect to the direction of the external magnetic field, the power receiving antenna is rotatable with respect to the first rotating shaft, and the weight arranged at one end in the rotating circuit direction, Always hold in a posture that allows the weight to re-approach to the ground surface. In addition, since the external housing of the wireless power receiving device is cylindrical, the device rolls so that the weight further approaches the ground surface. As a result, the power receiving antenna always maintains a vertical posture with respect to the ground surface. Will be. By maintaining the direction of the external magnetic field in a direction perpendicular to the ground surface, it is possible to always obtain efficient and constant received power without controlling the transmission power from the power signal generator.

(4) The wireless power receiving apparatus according to appendix 2, wherein the first and second rotating shafts also serve as electrodes of the power receiving antenna or the power receiving unit.

(5) The wireless power receiving apparatus according to appendix 3, wherein the first rotating shaft also serves as an electrode of the power receiving antenna.

  Thereby, the power receiving antenna or the power receiving unit can obtain electrical continuity.

(6) The electrode of the power receiving antenna includes a protruding electrode provided in a rotating outer peripheral direction of the power receiving antenna, and a rail electrode provided at a position facing the protruding electrode on the inner periphery of the power receiving unit. The wireless power receiving apparatus according to Appendix 2.

  As a result, the power receiving antenna can stably obtain electrical continuity.

The figure which shows the state which the capsule endoscope which shows 1st Embodiment of this invention was introduce | transduced in the body cavity. Sectional drawing of the capsule endoscope which follows the II-II line | wire in FIG. Sectional drawing of the capsule endoscope which follows the III-III line | wire in FIG. FIG. 4 is a cross-sectional view of a capsule endoscope showing a state in which a power receiving unit and a power receiving antenna are always directed in a gravitational direction by each weight in FIG. Sectional drawing which looked at the capsule endoscope which shows the 2nd Embodiment of this invention roughly from the front. Sectional drawing which looked at the capsule endoscope of FIG. 5 from the side. The fragmentary sectional view which shows the modification of a structure of a part of housing | casing of the power receiving unit of FIG. 1, and a 1st rotating shaft. Sectional drawing of the capsule endoscope which shows the modification of the shape of the power receiving unit of FIG. The perspective view which shows the outline of the external appearance of the conventional energy receiving unit. The figure which shows the outline of a structure of the electric circuit of the conventional energy receiving unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 1st rotation axis 2 ... 2nd rotation axis 3 ... Power receiving unit 4 ... Power receiving antenna 5 ... Weight 6 ... Weight 8 ... Exterior housing | casing 8i ... Inside 12 ... Coil electrode 14 ... Rail electrode 20 ... Housing 20i ... Inside 100 ... Capsule endoscope 200 ... Capsule endoscope 201 ... Third rotation shaft 205 ... Weight 208 ... Exterior casing 208i ... Inside 301 ... Needle-like electrode M ... Magnetic flux

Claims (6)

In a wireless power receiving apparatus having a receiving antenna that converts a magnetic field into electric power in an exterior housing,
The wireless power receiving apparatus, wherein the power receiving antenna is disposed so as to be rotatable in the exterior casing. The power receiving antenna has a first rotation axis with respect to the casing of the power receiving unit so that the power receiving antenna is rotatable with respect to the first axial direction in the casing of the power receiving unit provided in the exterior casing. Is pivotally supported by
The power receiving unit is pivotally supported by the second rotating shaft with respect to the outer casing so as to be rotatable with respect to a second axial direction orthogonal to the first axial direction within the outer casing. And
A weight that directs at least the power receiving antenna in a direction parallel to the magnetic field by rotation is provided on a part of the casing and a part of the power receiving antenna of the power receiving unit, respectively. The wireless power receiving apparatus according to claim 1. The power receiving antenna is pivotally supported by the third rotating shaft with respect to the outer casing so as to be rotatable with respect to the first axial direction in the outer casing.
The wireless power receiving apparatus according to claim 1, wherein a weight that directs the power receiving antenna in a direction parallel to the magnetic field by rotation is provided at least in a part of the power receiving antenna.   3. The wireless power receiving apparatus according to claim 2, wherein the first rotating shaft and the second rotating shaft are configured to also serve as the electrode for the power receiving antenna or the power receiving unit. 4. .   The wireless power receiving apparatus according to claim 3, wherein the third rotation shaft is configured to also serve as an electrode of the power receiving antenna.   The electrode of the power receiving antenna includes a protruding electrode provided on the outer periphery of the rotating power receiving antenna, and a rail electrode that is provided on the inner periphery of the casing of the power receiving unit and is always in contact with the protruding electrode. The wireless power receiving apparatus according to claim 2, comprising:

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