WO2010122389A1

WO2010122389A1 - Non-contact transmission apparatus

Info

Publication number: WO2010122389A1
Application number: PCT/IB2010/000843
Authority: WO
Inventors: Kyohei Kada; Takeshi Yano; Kazuhiro Suzuki; Akihide Sugawa; Atsushi Isaka
Original assignee: Panasonic Electric Works Co., Ltd.
Priority date: 2009-04-22
Filing date: 2010-04-15
Publication date: 2010-10-28
Also published as: JP2010259171A

Abstract

A non-contact transmission apparatus includes a primary coil for transmitting a power or a signal by a magnetic coupling; and a secondary coil for receiving the power or the signal, the coils being arranged to oppositely face each other. The coils are arranged in a reference pattern or one or more deviated patterns where the position of the secondary coil with respect to the primary coil is different from that in the reference pattern, and at least one of factors is set such that a coupling coefficient between the coils in the reference pattern is identical to that in each of the deviated patterns, the factors having inner or outer diameters of the coils; a relative position between the coils on a plane that is in parallel with oppositely facing surfaces of the coils,- and an angle at which the secondary coil is inclined with regard to the primary coil.

Description

NON-CONTACT TRANSMISSION APPARATUS

Field of the Invention

The present invention relates to a non-contact transmission apparatus which transmits or receives a power or an electric signal through at least one pair of coils in a non-contact fashion.

Background of the Invention

A non-contact transmission apparatus has recently been in the spotlight, wherein a power or an electric signal is transmitted and received between two electric devices in a non-contact fashion. For example, a portable terminal is mounted on a charger and thus charged in the non-contact fashion.

In such a non-contact transmission apparatus, if a high frequency signal is applied to a primary coil of one electric device, an external magnetic field is produced, thereby generating an induced voltage at a secondary coil of the other electric device . By rectifying the induced voltage by a diode or the like, it is possible to charge a secondary battery that is built in the other electric device. Moreover, a two-way transmission of signals can be performed in the non-contact fashion through a magnetic coupling between the primary and the secondary coil.

In such a non-contact transmission apparatus mentioned above, a position of the secondary coil may be relatively deviated with regard to that of the primary coil, thereby changing a coupling coefficient therebetween. Accordingly, a charging efficiency and a signal transmission efficiency may be lowered. To solve such a problem, some conventional methods have been disclosed (see, e.g., Japanese Patent No. 3887828 and corresponding U.S. patent No. 6265789 Bl; and Japanese Patent Application Publication No. 2008-289241) . According to the conventional methods, the charging efficiency and the signal transmission efficiency may be improved by determining a ratio of the inner diameter of the primary coil to the outer diameter thereof and a ratio of the inner diameter of the secondary coil to the outer diameter thereof, or a mutual relationship between the inner and the outer diameter of each of the primary coil and the secondary coil when a relative position deviation of the secondary coil with regard to the primary coil occurs.

Although it is possible to improve the charging efficiency and the signal transmission efficiency when a relative position of the secondary coil with regard to the primary coil is deviated in the conventional methods, a power or an electric signal can merely be transmitted and received with a charging efficiency and a signal transmission efficiency which are improved within respective allowable ranges of the efficiencies in an ordinary case where no position deviation occurs between the coils.

Accordingly, the power or the electric signal may be unable to be transmitted and received with a same magnitude both in the normal case that no position deviation occurs between the coils and in the case that the position deviation occurs therebetween. As a result, the reliability of the transmission and the reception of the power or the electric signal may be deteriorated.

Summary of the Invention

In view of the above, the present invention provides a non-contact transmission apparatus capable of transmitting and receiving a power or a signal with a same magnitude as that of the normal case even though a position deviation occurs between coils.

In accordance with an embodiment of the present invention, there is provided a non-contact transmission apparatus including a primary coil for transmitting a power or an electric signal by a magnetic coupling; and a secondary coil for receiving the power or the electric signal transmitted from the primary coil through a magnetic coupling, the secondary coil being arranged to oppositely face the primary coil. The primary coil and the secondary coil are arranged in a reference pattern or one or more deviated patterns where the position of the secondary coil with respect to the primary coil is different from that in the reference pattern, and at least one of factors is set such that a coupling coefficient between the primary coil and the secondary coil in the reference pattern is identical to that in each of the deviated patterns, the factors having inner or outer diameters of the primary and the secondary coil; a relative position between the primary and the secondary coil on a plane that is in parallel with oppositely facing surfaces of the coils,- and an inclination angle at which the secondary coil is inclined with regard to the primary coil.

When the inner and outer diameters of the primary coil and the secondary coil are regular, the inclination angle is regular at which the secondary coil is inclined with regard to the primary coil, and the relative position between the primary and the secondary coil on the plane that is in parallel with the oppositely facing surfaces of the coils in the deviated pattern is different from that in the reference pattern, the primary and the secondary coil is provided in a plural number, and the primary coil or secondary coils are adjacently arranged on a same planar surface such that the coupling coefficient in the deviated pattern is identical to that in the reference pattern.

The apparatus may further include a positioning part provided, to position each of the primary and the secondary- coil, at a predetermined portion on the plane that is in parallel with the oppositely facing surfaces of the coils such that the coupling coefficient in the deviated pattern is identical to that in the reference pattern, when the inner and outer diameters of the primary and the secondary coil are regular and the inclination angle at which the secondary coil is inclined with regard to the primary coil in the deviated pattern is different from that in the reference pattern.

The apparatus may further include an inclination maintaining unit provided to maintain an inclination angle at which one of the primary coil and the secondary coil is inclined with regard to the other such that the coupling coefficient in the deviated pattern is identical to that in the reference pattern, when the relative position between the primary and the secondary coil is regular on the plane that is in parallel with the oppositely facing surfaces of the coils in the deviated pattern and the inner or outer diameter of at least one of the primary and the secondary coil in the deviated pattern is different from that in the reference pattern.

In accordance with the embodiment of the present invention, it is possible to obtain a same coupling coefficient as that of the ordinary case even though a position deviation occurs between a primary and a secondary coil. Accordingly, a power or a signal can be transmitted and received with the same magnitude regardless of whether or not the position deviation occurs between the primary and the secondary coil. Therefore, it is possible to prevent the reliability of transmission and reception of a power or a signal from being deteriorated.

Brief Description of the Drawings

The objects and features of the present invention will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which:

Figs. IA and IB show a non-contact transmission apparatus in accordance with a first embodiment of the present invention and, specifically, Fig. IA shows a relationship between coils in a reference pattern and Fig.

IB shows a relationship between coils in a deviated pattern; Figs. 2A to 2C are graphs showing a relationship between an inner diameter of a primary coil and a coupling coefficient when an inner diameter of a secondary coil is variously changed.

Figs. 3A to 3C show a non-contact transmission apparatus in accordance with a second embodiment of the present invention and, specifically, Fig. 3A is a plan view showing primary coils and Figs. 3B and 3C are side cross sectional views showing the primary coils and the secondary coil;

Figs. 4A to 4C show a non-contact transmission apparatus in accordance with a third embodiment of the present invention and, specifically, Fig. 4A is a side view showing a first device body and Figs. 4B and 4C show how a second device body is coupled to the first device body in accordance with two methods, respectively; and

Figs. 5A and 5B show a non-contact transmission apparatus in accordance with a fourth embodiment of the present invention and, specifically, Fig. 5A is a side view showing a position relationship between coils when a secondary coil has a large inner diameter and Fig. 5B is a side view showing a position relationship between coils when a secondary coil has a small inner diameter.

Detailed Description of the Embodiments

(First Embodiment) Hereinafter, a non-contact transmission apparatus in accordance with a first embodiment of the present invention will be described with reference to Figs. IA to 2C. The upper and the lower side shown in a vertical cross sectional view of Fig. IA are referred to as the upper and the lower direction, respectively, in the below.

The non-contact transmission apparatus in accordance with the first embodiment, as shown in Figs. IA and IB, includes a primary coil 1 for transmitting a power or an electric signal through the magnetic coupling and a secondary coil 2 for receiving the power or the electric signal from the primary coil through the magnetic coupling, the secondary coil being arranged to oppositely face the primary coil . The present embodiment has a feature that inner diameters rl and r2 of the coils 1 and 2 are respectively set such that a coupling coefficient k between the coils 1 and 2 in a reference pattern as shown in Fig. IA is the same as that in a deviated pattern as shown in Fig. IB. A pattern shown in Fig. IA is set as the reference pattern, wherein the position of the secondary coil 2 with respect to the primary coil 1 is referenced. A pattern shown in Fig. IB is set as the deviated pattern, wherein the position of the secondary coil 2 with respect to the primary coil 1 is different from that in the reference pattern.

The primary coil 1 is a substantially ring-shaped empty core coil having an inner and an outer diameter rl and Rl and includes a top surface serving as a transmission surface for transmitting a power or an electric signal . The primary coil 1 further includes a substantially disk-shaped magnetic sheet 10 provided on a bottom surface thereof opposite to the transmission surface, the magnetic sheet 10 having a substantially same outer diameter as that of the primary coil 1. The magnetic sheet 10 serves to increase an inductance of the primary coil 1.

The secondary coil 2 is a substantially ring-shaped empty core coil having an inner and an outer diameter r2 and R2 and includes a bottom surface serving as a reception surface for receiving a power or an electric signal transmitted from the primary coil^'l. The secondary coil 2 further includes a substantially disk-shaped magnetic sheet 20 provided on a top surface thereof opposite to the reception surface, the magnetic sheet 20 having a substantially same outer diameter as that of the secondary coil 2. The magnetic sheet 20 serves to increase an inductance of the secondary coil 2.

Hereinafter, the reference pattern and the deviated pattern in the present embodiment will be described. In the reference pattern, a central axis of the secondary coil 2 is the same as that of the primary coil 1 and a distance d between the primary and the secondary coil 1 and 2 is set to be 5.3 mm. In the deviated pattern, the central axis of the secondary coil 2 is horizontally deviated from that of the primary coil 1 by a predetermined distance g, e.g., 6 mm and the distance d therebetween is set to be 3.3 mm.

Otherwise, the reference pattern and the deviated pattern have same following parameters. The outer diameter Rl and the thickness tl of the primary coil 1 are set to be 30 mm and 0.17 mm, respectively. The outer diameter R2 and the thickness t2 of the secondary coil 2 are set to be 15 mm and 0.3 mm, respectively. The thicknesses tlO and t20 of the magnetic sheets 10 and 20 are set to be 1 mm and 0.02 mm, respectively. Further, the transmission surface of the primary coil 1 is in parallel with the reception surface of the secondary coil 2 and the secondary coil 2 is not inclined with regard to the primary coil 1.

Figs. 2A to 2C are graphs showing relationships between the inner diameter rl of the primary coil 1 and the coupling coefficient k between the coils 1 and 2 when the inner diameter r2 of the secondary coil 2 is set to be 3 mm, 6 mm, and 9 mm, respectively: From the graphs shown in Figs. 2A to 2C, it may be seen that there are values of the inner diameter rl of the primary coil 1 that make the coupling coefficient k of the reference pattern be the same as that of the deviated pattern in any case where the inner diameter r2 of the secondary coil 2 is set to be about 3 mm, 6 mm, or 9 mm.

Accordingly, even though a position deviation occurs between the primary and the secondary coil 1 and 2, it is possible to obtain the same coupling coefficient k between the coils 1 and 2 as that of the ordinary case where no position deviation occurs therebetween by adequately setting the inner diameters rl and r2 of the primary and the secondary coil 1 and 2, respectively. Therefore, the power or the signal can be transmitted and received with the same magnitude, thereby preventing ' the reliability of transmission and reception of a power or a signal from being deteriorated.

In the present embodiment, the relative position relationship between the primary and the secondary coil 1 and 2 is merely an example for the relationship between the reference pattern and the deviated pattern. The relationship therebetween is not limited thereto. Alternatively, the deviated pattern may be configured in various ways such that the coupling coefficient in the deviated pattern is the same as that in the reference pattern.

(Second Embodiment)

Hereinafter, a non-contact transmission apparatus in accordance with a second embodiment of the present invention will be described with reference to Figs. 3A to 3C. The second embodiment has a feature that a plurality of primary coils 1 (e.g., 4 primary coils 1 in Fig. 3A) are adjacently positioned on a same planar surface. In the present embodiment, an inner and an outer diameter of the primary coils 1 are regular, an inner and an outer diameter of the secondary coil 2 are regular, and a distance between the primary coils 1 and the secondary coil 2 is regular. Further, the transmission surfaces of the primary coils 1 are in parallel with the reception surface of the secondary coil 2 and the secondary coil 2 is not inclined with regard to the primary coils 1. In the present embodiment, a pattern shown in Fig. 3B is set as a reference pattern, wherein a center of the secondary coil 2 is positioned on a central axis of one of the primary coils 1. A pattern shown in Fig. 3C is referred to as a deviated pattern, wherein the secondary pattern 2 is positioned across any adjacent two primary coils 1. As shown in Figs. 3B and 3C, a ratio of magnetic force lines passing through the secondary coil 2 to those generated by the primary coils 1 in the reference pattern is the same as that in the deviated pattern. In other words, since the coupling coefficient between the coils 1 and 2 in the reference pattern is the same as that in the deviated pattern, it is possible to obtain the same effect as that of the first embodiment. In the present embodiment, it is also possible to widen an allowance range of position deviation of the secondary coil 2 with regard to the reference pattern because the same coupling coefficient as that in the reference pattern can be obtained without the position restriction to the secondary coil 2 when the secondary coil 2 is positioned within a region where the primary coils 1 are arranged .

As described above, a plurality of primary coils 1 is adjacently arranged in the present embodiment. Alternatively, a plurality of secondary coils 2 may be adjacently arranged instead of the primary coils 1. In even this case, it is possible to obtain the same effect as that of the first embodiment as well. Similarly, it is also possible to widen an allowance range of position deviation of the primary coil 1 with regard to a reference pattern because the same coupling coefficient as that in the reference pattern can be obtained without the position restriction to the primary coil 1 when the primary coil 1 is positioned within a region where the secondary coils 2 are arranged . (Third Embodiment)

Hereinafter, a non-contact transmission apparatus in accordance with a third embodiment of the present invention will be described with reference to Figs. 4A to 4C. As shown in Fig. 4A, the third embodiment features a shape of a first device body 3, the first device body 3 having a primary coil 1 therein; and a positioning part for allowing a second device body 4 having therein a secondary coil 2 to be coupled to the first device body 3 at a predetermined portion thereof. In the present embodiment, an inner and an outer diameter of the primary coil 1 are regular, an inner and an outer diameter of the secondary coil 2 are regular, and a distance between the primary coil 1 and the secondary coil 2 is regular. Further, such combination of the first and the second device body 3 and 4 includes, e.g., the combination of a charger and a portable terminal, but is not limited thereto. The combination thereof may include combinations of any other apparatuses having the primary and the secondary coil 1 and 2, respectively.

The positioning part includes a first positioning part and a second positioning part. The first positioning part includes a flat surface 30 that is in parallel with a surface on which the primary coil 1 is mounted; and an indentation 31 provided in a same planar surface as that of the flat surface 30, the indentation 31 having a substantially right-triangle shaped cross section. The second device body 4 is partially mounted on the indentation 31. The second positioning part includes a flat surface 32 that is inclined with regard to the surface on which the primary coil 1 is mounted; and an indentation 33 provided in a same planar surface as that of the flat surface 32, the indentation 33 having a substantially right-triangle shaped cross section. The second device body 4 is partially mounted on the indentation 33.

When the second device body 4 is coupled to the first device body 3 on the first positioning part, one longer edge portion of the second device body 4 is put into an edge portion of the indentation 31 and the other longer edge portion thereof is mounted on the flat surface 30 as shown in Fig. 4B. Similarly, when the second device body 4 is coupled to the first device body 3 on the second positioning part, one longer edge portion of the second device body 4 is put into an edge portion of the indentation 33 and the other longer edge portion thereof is mounted on the flat surface 32 as shown in Fig. 4C.

When the second device body 4 is coupled to the first device body 3 on the first positioning part, a center of the secondary coil 2 is deviated from a central axis of the primary coil 1. On the other hand, when the second device body 4 is coupled to the first device body 3 on the second positioning part, the center of the secondary coil 2 is positioned on the central axis of the primary coil 1. In the present embodiment, a pattern shown in Fig. 4B is set as a reference pattern, wherein the transmission surface of the primary coil 1 is in parallel with the reception surface of the secondary coil 2. A pattern shown in Fig. 4C is set as a deviated pattern, wherein the reception surface of the secondary coil 2 is inclined at a predetermined angle with reference to the transmission surface of the primary coil 1. As shown in Figs. 4B and 4C, the second device body 4 is coupled to the first device body 3 on the first positioning part in the reference pattern and on the second positioning part in the deviated pattern. In this way, the coupling coefficient in the deviated pattern can be made identical to that in the reference pattern. Accordingly, it is possible to obtain the same effect as that of the first embodiment. In the present embodiment, the relative position relationship between the primary and the secondary coil 1 and 2 is merely an example for the relationship between the reference pattern and the deviated pattern. The relationship between the reference pattern and the deviated pattern is not limited thereto. In addition, the configuration of the positioning part is not limited to the present embodiment. Alternatively, the positioning part may be configured in various ways such that the coupling coefficient in the reference pattern is the same as that in the deviated pattern. (Fourth Embodiment)

Hereinafter, a non-contact transmission apparatus in accordance with a fourth embodiment of the present invention will be described with reference to Figs. 5A and 5B . As shown in Fig. 5B, the fourth embodiment features an inclination maintaining unit 7 for maintaining a predetermined angle at which a secondary coil 6 of a third device body 5 is inclined with regard to the primary coil 1 of a first device body 3' . In the present embodiment, an inner and an outer diameter of the primary coil 1 are regular and a distance between the primary coil 1 and the secondary coil 2 is regular. In addition, a center of the secondary coil 2 is positioned on a central axis of the primary coil 1. Further, such combination of the first and the second device body 3' and 4 includes, e.g., a combination of a charger and a portable terminal, but is not limited thereto as in the third embodiment. The combination thereof may include combinations of any other apparatuses having the primary and the secondary coil 1 and 2, respectively.

In the present embodiment, the second device body 4 having therein the secondary coil 2 whose outer diameter is smaller than that of the primary coil 1 and the third device body 5 having the secondary coil 6 whose outer diameter is substantially identical to that of the primary coil 1 are respectively coupled to the first device body 3' . A pattern shown in Fig. 5A is set as a reference pattern, wherein the second device body 4 is mounted on the first device body 3' . A pattern shown in Fig. 5B is set as a deviated pattern, wherein the third device body 5 is mounted on the first device body 3 ' . For example, if the transmission surface of the primary coil 1 is in parallel with the reception surface of the secondary coil 6 in the deviated pattern, the coupling coefficient in the deviated pattern becomes different from that in the reference pattern. In the present embodiment, it is possible to allow the coupling coefficient in the deviated pattern to be the same as that in the reference pattern by maintaining a predetermined angle at which the secondary coil 6 of the third device body 5 is inclined with regard to the primary coil 1 of the first device body 3' by the inclination maintaining unit 7. Accordingly, even when the same device (the first device body 3' in the present embodiment) is used for a plurality of devices having coils of different sized diameters (the second and the third device body 4 and 5 in the present embodiment) , a power or a signal can be transmitted and received with the same magnitude, thereby preventing a reliability of transmission and reception of a power or a signal from being deteriorated.

In the present embodiment, the inclination maintaining unit 7 is provided in the third device body 5 as described above. Alternatively, the inclination maintaining unit 7 may be provided in the first device body 3' to maintain a predetermined angel at which the primary coil 1 of the first device body 3' is inclined with regard to the secondary coil 6 of the third device body 5. It is possible to obtain the same effect as described above in even this case.

While the invention has been shown and described with respect to the embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Claims

What is claimed is:

1. A non-contact transmission apparatus comprising: a primary coil for transmitting a power or an electric signal by a magnetic coupling; and a secondary coil for receiving the power or the electric signal transmitted from the primary coil through a magnetic coupling, the secondary coil being arranged to oppositely face the primary coil, wherein the primary coil and the secondary coil are arranged in a reference pattern or one or more deviated patterns where the position of the secondary coil with respect to the primary coil is different from that in the reference pattern, and wherein at least one of factors is set such that a coupling coefficient between the primary coil and the secondary coil in the reference pattern is identical to that in each of the deviated patterns, the factors having inner or outer diameters of the primary and the secondary coil; a relative position between the primary and the secondary coil on a plane that is in parallel with oppositely facing surfaces of the coils; and an inclination angle at which the secondary coil is inclined with regard to the primary coil.

2. The apparatus of claim 1, wherein, when the inner and outer diameters of the primary coil and the secondary coil are regular, the inclination angle is regular at which the secondary coil is inclined with regard to the primary coil, and the relative position between the primary and the secondary coil on the plane that is in parallel with the oppositely facing surfaces of the coils in the deviated pattern is different from that in the reference pattern, the primary coil or the secondary coil is provided in plural number, and the primary coils or the secondary coils are adjacently arranged on a same planar surface such that the coupling coefficient in the deviated pattern is identical to that in the reference pattern.

3. The apparatus of claim 1, further comprising a positioning part provided, to position each of the primary and the secondary coil, at a predetermined portion on the plane that is in parallel with the oppositely facing surfaces of the coils such that the coupling coefficient in the deviated pattern is identical to that in the reference pattern, when the inner and outer diameters of the primary and the secondary coil are regular and the inclination angle at which the secondary coil is inclined with regard to the primary coil in the deviated pattern is different from that in the reference pattern.

4. The apparatus of claim 1, further comprising an inclination maintaining unit provided to maintain an inclination angle at which one of the primary coil and the secondary coil is inclined with regard to the other such that the coupling coefficient in the deviated pattern is identical to that in the reference pattern, when the relative position between the primary and the secondary coil is regular on the plane that is in parallel with the oppositely facing surfaces of the coils in the deviated pattern and the inner or outer diameter of at least one of the primary and the secondary coil in the deviated pattern is different from that in the reference pattern.