Patent Publication Number: US-9906076-B2

Title: Non-contact type power transmitting coil and non-contact type power supplying apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application Nos. 10-2013-0136570 filed on Nov. 11, 2013, 10-2014-0078487, filed on Jun. 25, 2014, and 10-2014-0096826, filed on Jul. 29, 2014, with the Korean Intellectual Property Office, the disclosures of which are incorporated in their entireties herein by reference. 
     BACKGROUND 
     The present disclosure generally relates to a non-contact type power transmitting coil and a non-contact type power supplying apparatus. 
     In general, supplying power as an energy source may be needed to operate an electronic apparatus. For example, power may be supplied from an external source, and a self-sustaining apparatus may be able to obtain electrical power through the self-generation thereof. 
     In order to supply external power to the electronic apparatus, a power supplying apparatus for transmitting power from an external power source to the electronic apparatus may be needed. 
     A wired-type power supplying apparatus may be connected directly to the electronic apparatus through a connector, or the like, to supply power to a battery provided in the electronic apparatus. A non-contact type power supplying apparatus may supply power to the battery provided in the electronic apparatus in a non-contact manner using, for example, a magnetic induction effect or a magnetic resonance effect. 
     For instance, to transmit power in the non-contact manner through the magnetic induction effect or magnetic resonance effect, a power transmitting coil and a power receiving coil may be used to be disposed adjacently to one another. In this regard, there may arise issues of, for example, power transmission efficiency and levels of transmittable power based on a distance between the power transmitting coil and the power receiving coil. 
     RELATED ART DOCUMENT 
     Patent Document 
     
         
         (Patent Document 1) Korean Patent Laid-Open Publication No. 10-2013-0093667 
       
    
     SUMMARY 
     Some embodiments of the present disclosure may provide a non-contact type power transmitting coil and a non-contact type power supplying apparatus capable of suppressing a decrease in power transmission efficiency depending on positions of a power transmitting coil and a power receiving coil disposed on or over a power transmitting surface. 
     According to an aspect of the present disclosure, a non-contact type power transmitting coil may include at least one conductor pattern disposed on at least one surface of a base having a predetermined area, having a plurality of turns, and transmitting received power externally in a non-contact manner. Intervals between at least some of adjacent pattern portions of the conductor pattern in a direction from a center of an inner diameter of the conductor pattern to an outermost pattern portion of the conductor pattern may be different from one another. 
     According to another aspect of the present disclosure, in the non-contact type power transmitting coil, widths of at least some of adjacent pattern portions of the conductor pattern in a direction from a center of an inner diameter of the conductor pattern to an outermost pattern portion of the conductor pattern may be different from one another. 
     According to another aspect of the present disclosure, a non-contact type power supplying apparatus may include a base having a predetermined area, at least one conductor pattern disposed on at least one surface of the base and having a plurality of turns, and a power unit transmitting power to the conductor pattern to transmit the power externally in a non-contact manner. Widths of at least some of adjacent pattern portions of the conductor pattern in a direction from a center of an inner diameter of the conductor pattern to an outermost pattern portion of the conductor pattern may be different from one another. 
     According to another aspect of the present disclosure, in the non-contact type power supplying apparatus, widths of at least some of adjacent pattern portions of the conductor pattern in a direction from a center of an inner diameter of the conductor pattern to an outermost pattern portion of the conductor pattern may be different from one another. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic view illustrating a non-contact type power supplying apparatus according to an exemplary embodiment in the present disclosure; 
         FIGS. 2A through 2G  are schematic plan views of non-contact type power transmitting coils according to exemplary embodiments in the present disclosure; 
         FIG. 3A  is an efficiency graph based on a distance between a power transmitting coil and a power receiving coil in accordance with an exemplary embodiment; 
         FIG. 3B  is a plan view of a power transmitting coil in accordance with an exemplary embodiment; 
         FIG. 3C  is an efficiency graph based on positions of the power transmitting coil illustrated in  FIG. 3B  and the power receiving coil in accordance with an exemplary embodiment; 
         FIG. 4  is a view illustrating strength of a magnetic field of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure; 
         FIG. 5  is a view illustrating a current density of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure; 
         FIGS. 6A and 6B  are views illustrating strengths of magnetic fields of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure; 
         FIGS. 7A and 7B  are views illustrating strengths of electric fields of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure; and 
         FIG. 8  is a view illustrating power transmitting efficiencies depending on positions of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments in the present disclosure will be described in detail with reference to the accompanying drawings. 
     The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. 
     In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements. 
       FIG. 1  is a schematic view illustrating a non-contact type power supplying apparatus according to an exemplary embodiment in the present disclosure. 
     Referring to  FIG. 1 , a non-contact type power supplying apparatus  100  according to an exemplary embodiment in the present disclosure may include a coil  110  and a power unit  120 . 
     The coil  110  may transmit power externally in a non-contact manner. The power unit  120  may transmit the power to the coil  110 . 
     Here, the non-contact manner may refer to, for example, but not limited to, a method of power transmission from a transmitter to a receiver without a direct connection between conductors of the transmitter and the receiver. Additionally, the non-contact manner may be referred to as a contactless method, a wireless transmission method, or the like. 
     A power receiving apparatus A may be disposed on a power transmitting surface of the non-contact type power supplying apparatus  100 . Power of the non-contact type power supplying apparatus  100  may be transmitted from the power transmitting surface of the non-contact type power supplying apparatus  100 , such that power from the coil  110  may be transmitted to a power receiving coil a of the power receiving apparatus A. 
     In a case in which the power receiving apparatus A disposed on the power transmitting surface of the non-contact type power supplying apparatus  100  receives the power from the non-contact type power supplying apparatus  100 , power transmission efficiency may change based on a distance between the power receiving apparatus A and the coil  110  of the non-contact type power supplying apparatus  100 , for instance, but not limited to, a distance between the power receiving coil a of the power receiving apparatus A and the coil  110  of the non-contact type power supplying apparatus  100 . 
     For example, the non-contact type power transmitting coil according to the exemplary embodiment in the present disclosure may be configured as illustrated in  FIGS. 2A-2G . 
       FIGS. 2A through 2G  are schematic plan views of non-contact type power transmitting coils according to exemplary embodiments in the present disclosure. 
     Referring to  FIG. 2A , the non-contact type power transmitting coil  110  according to an exemplary embodiment in the present disclosure may include a base  111  and a conductor pattern  112 . 
     As illustrated in  FIG. 1 , a plurality of conductor patterns may be provided. Since a plurality of the conductor patterns may have the same or similar operation and function as or with a single conductor pattern, a non-contact type power transmitting coil including a single conductor pattern will be described hereinafter for ease of description. 
     The base  111  may have a predetermined area. The conductor pattern  112  may be disposed on at least one surface of the base  111 . 
     The conductor pattern  112  disposed on the surface of the base  111  may have a plurality of turns, and may include a plurality of bent pattern portions  112   a   1  to  112   a   6 ,  112   b   1 ,  112   c   1 , and  112   d   1 , and the plurality of bent pattern portions  112   a   1  to  112   a   6 ,  112   b   1 ,  112   c   1 , and  112   d   1  may be electrically connected to one another so as to form a single pattern having a plurality of turns. 
     As described above, the plurality of bent pattern portions  112   a   1  to  112   a   6 ,  112   b   1 ,  112   c   1 , and  112   d   1  may be electrically connected to another to thereby have the plurality of turns. In addition, at least one of straight pattern portions  112   l   1 ,  112   l   2 , and  112   l   3  may be formed between at least two bent pattern portions  112   a   1 ,  112   b   1 ,  112   c   1  and  112   d   1 , such as  112   a   1  and  112   b   1 ,  112   b   1  and  112   c   1 , and  112   c   1  and  112   d   1 , respectively, to thereby form electrical connections between the bent pattern portions  112   a   1  and  112   b   1 ,  112   b   1  and  112   c   1 , and  112   c   1  and  112   d   1 . Therefore, a single pattern having the plurality of turns may be formed. 
     Accordingly, the conductor pattern  112  having a plurality of turns may be provided in various forms such as a circular pattern, a quadrangular pattern, and the like. 
     At least some of distances d 1 , d 2 , d 3 , d 4 , and d 5 , between adjacent bent pattern portions  112   a   1  and  112   a   2 ,  112   a   2  and  112   a   3 ,  112   a   3  and  112   a   4 ,  112   a   4  and  112   a   5 , and  112   a   5  and  112   a   6 , respectively, in a direction α from a center c of the conductor pattern  112  to an outermost pattern portion may be different from one another. 
     For example, the distances d 1 , d 2 , d 3 , d 4 , and d 5  between the adjacent bent pattern portions  112   a   1  and  112   a   2 ,  112   a   2  and  112   a   3 ,  112   a   3  and  112   a   4 ,  112   a   4  and  112   a   5 , and  112   a   5  and  112   a   6  in the direction α, respectively, may be gradually decreased. 
     Straight pattern portions  112   l   1 ,  112   l   2 ,  112   l   3 ,  112   l   1   a ,  112   l   1   b ,  112   l   1   c ,  112   l   1   d , and  112   l   1   e  may be additionally formed. At least some of distances l 1 , l 2 , l 3 , and l 4  between adjacent straight pattern portions  112   l   1  and  112   l   1   a ,  112   l   1   a  and  112   l   1   b ,  112   l   1   b  and  112   l   1   c ,  112   l   1   c  and  112   l   1   d , and  112   l   1   d  and  112   l   1   e  in a direction β from the center c of the conductor pattern  112  to the outermost pattern portion may be different from one another. For instance, the distances l 1 , l 2 , l 3 , and l 4  between adjacent straight pattern portions may be gradually decreased. 
     For example, the conductor pattern  112  may be disposed on both surfaces of the base  111  for convenience of pattern formation. For example, in order to prevent an overlap of the conductor patterns  112 , one or more portions of the conductor patterns  112  transmitting power may be disposed on one surface of the base  111  opposed to the other surface of the base  111  on which the conductor patterns  112  having the plurality of turns are disposed. 
     The conductor pattern  112  may also be used for a near field communications (NFC) antenna. 
     Referring to  FIG. 2B , in pattern formation, the conductor pattern  112  may comprise a region  140  having different intervals between pattern portions and a region  130  having the same intervals between the pattern portions. The region  140  having different intervals between the pattern portions and the region  130  having the same intervals between the pattern portions may be provided in an alternating manner. Additionally, the conductor pattern  112  may have a plurality of the regions  130  and/or  140 . For instance, the regions  130  and  140  may be alternatively formed. 
     As illustrated in  FIGS. 2C and 2D , a conductor pattern  112  may have various shapes, for example, but not limited to, a circular shape or an octagonal shape. 
     As illustrated in  FIG. 2E , a conductor pattern  112  may have the same horizontal length and vertical length. Intervals between pattern portions of the conductor patter  112  may be gradually decreased in an outward direction from the center of the conductor pattern  112 . Additionally, the intervals between pattern portions of the conductor patter  112  may be decreased at the same ratio. 
     As illustrated in  FIG. 2F , pattern portions of the conductor pattern  112  may have the same intervals. Line widths of the conductor pattern  112  may be gradually decreased in an outward direction from the center of the conductor pattern  112 . 
     As illustrated in  FIG. 2G , intervals between pattern portions of the conductor pattern  112  may be gradually decreased in an outward direction from the center of the conductor pattern  112 . Line widths of the pattern portions of the conductor pattern  112  may be gradually decreased in the outward direction from the center of the conductor pattern  112  based on an aspect ratio of the pattern. Line widths of the conductor pattern  112  may be decreased at a different ratio from one another in the same turn. For example, as illustrated in  FIG. 2G , the conductor pattern  112  may be provided in a rectangular shape having a horizontal length greater than a vertical length. Line widths of pattern portions of the conductor pattern  112  in a first direction perpendicular to the center of the conductor pattern  112  may be narrower than line widths of pattern portions of the conductor pattern  112  in a second direction horizontal to the center of the conductor pattern  112 , or vice versa. 
     Hereinafter, an electric action or character changed by the above-mentioned intervals between the pattern portions of the conductor pattern  112  will be described. 
       FIG. 3A  is an efficiency graph based on a distance between a power transmitting coil and a power receiving coil in accordance with an exemplary embodiment,  FIG. 3B  is a plan view of a power transmitting coil in accordance with an exemplary embodiment, and  FIG. 3C  is an efficiency graph based on positions of the power transmitting coil illustrated in  FIG. 3B  and the power receiving coil in accordance with an exemplary embodiment. 
     In general, power transmission efficiency between a power transmitting coil transmitting power in a non-contact manner and a power receiving coil receiving the power may be decreased as a distance d between respective centers of the coils is increased as illustrated in  FIG. 3A . Ina case in which coils  110  having a plurality of turns and a pattern array at the same intervals are provided as illustrated in  FIG. 3B , high efficiency may be achieved when the centers of the coils  110  coincide through a large amount of a magnetic field being collected on an opening surface at central portions of the coils. However, as illustrated in  FIG. 3C , when the center of the power receiving coil deviates from the center of the power transmitting coil, a level of efficiency may be sharply decreased. In detail, when a position of the power receiving coil moves from the center of the power transmitting coil in an outward direction on an X axis or a Y axis, power transmission efficiency may be the lowest level. 
       FIG. 4  is a view illustrating strength of a magnetic field of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure. 
     Referring to  FIGS. 2A and 4 , according to an exemplary embodiment in the present disclosure, the intervals between the pattern portions of the non-contact type power transmitting coil  110 , namely, a line density may be relatively high in the outer portion of the coil and may be decreased inwards thereof. In other words, the intervals between the pattern portions of the non-contact type power transmitting coil  110  may be increased towards the center of the coil, hereinafter referred to as non-equidistant intervals. 
     As illustrated in  FIG. 4 , according to Ampere&#39;s right hand rule, a magnetic field F may be formed to be perpendicular to a direction of a current flow. Strength of the magnetic field F may increase as closer to the current flow. Accordingly, the magnetic field may be formed in the same direction, as currents flow in all electric wires in the central portion of the coil in the same direction, whereby high charging efficiency may be realized. In this example, a magnetic field greater than that of the equidistant coil illustrated in  FIG. 3B  may be formed in the non-equidistant coil according to the exemplary embodiment in the present disclosure, because a distance from the center of the coil to an innermost pattern portion is relatively reduced as compared to the equidistant coil illustrated in  FIG. 3B . 
     In addition, the strength of the magnetic field may be sharply decreased as farther from the center of the coil because the equidistant coil has a strong magnetic field at the center thereof whereas a line density is high in the outer portion of the coil. Conversely, as compared to the equidistant coil, the non-equidistant coil according to the exemplary embodiment in the present disclosure which has the pattern portions formed between the center of the coil and the outer portion thereof may form a relatively flat magnetic field on a predetermined area. Accordingly, a degree of freedom for the position of the center of the non-equidistant coil may be increased as compared to the equidistant coil. That is, a sharp decrease in the power transmission efficiency may be avoided even in the outer portion of the coil distant from the center of the coil. 
     However, the strength of the magnetic field may be decreased in the outer portion of the non-equidistant coil. To compensate for the decreased magnetic field, the line density may increase in the outward direction from the center of the non-equidistant coil. In other words, such a power transmission efficiency decrease caused by the magnetic field may be compensated for by transmitting power through the electric field formed by the current flowing in the coil. 
       FIG. 5  is a view illustrating a current density of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure. 
     As illustrated in  FIG. 5 , in a case in which a current density is increased and the power receiving coil a of the power receiving apparatus A is disposed on a coil portion of the non-contact type power transmitting coil having a high line density, a strong electric field may be formed by a high current density, whereby power may be transmitted at a high level of efficiency. 
     In  FIG. 5 , blue indicates the coil, and red, yellow, and green indicate degrees of current density. The degrees of current density are lowered in order of red-yellow-green. The current density may be increased in an outward direction such that the strong electric field may be formed in the outer portion of the coil. The current density may be displacement current density. 
     The line widths t of the pattern portions, as illustrated in  FIGS. 2F and 2G , and/or the intervals between the pattern portions of the coil, may be formed in a non-equidistant manner. 
     For example, in order to increase power transmission efficiency, the current density in the outer portion of the coil may be increased by increasing or decreasing the line width of the coil in an outward direction from the center of the coil. 
     In addition, as illustrated in  FIG. 2G , the line width of the coil may be partially varied based on the aspect ratio of the coil and/or the intervals between the pattern portions of the coil may be varied at different ratios in the same turn. 
       FIGS. 6A and 6B  are views illustrating strengths of magnetic fields of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure. 
     In a case in which the power receiving coil a of the power receiving apparatus is disposed at the center of the non-contact type power transmitting coil  110  as illustrated in  FIG. 6A , the strength of the magnetic field formed in a direction from the non-contact type power transmitting coil  110  to the power receiving coil a may be increased. Conversely, in a case in which the power receiving coil a of the power receiving apparatus is disposed in the outer portion of the non-contact type power transmitting coil  110  as illustrated in  FIG. 6B , the strength of the magnetic field formed in the direction from the non-contact type power transmitting coil  110  to the power receiving coil a may be decreased. 
       FIGS. 7A and 7B  are views illustrating strengths of electric fields of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure. 
     In a case in which the power receiving coil a of the power receiving apparatus is disposed at the center of the non-contact type power transmitting coil  110  as illustrated in  FIG. 7A , the strength of the electric field formed in the direction from the non-contact type power transmitting coil  110  to the power receiving coil a may be decreased. Conversely, in a case in which the power receiving coil a of the power receiving apparatus is disposed in the outer portion of the non-contact type power transmitting coil  110  as illustrated in  FIG. 7B , the strength of the electric field formed in the direction from the non-contact type power transmitting coil  110  to the power receiving coil a may be increased. 
       FIG. 8  is a view illustrating power transmitting efficiencies depending on positions of a non-contact type power transmitting coil according to an exemplary embodiment in the present disclosure. 
     The non-contact type power transmitting coil according to the exemplary embodiment in the present disclosure may have high power transmission efficiency in the central portion thereof by the magnetic field and may have high power transmission efficiency in the outer portion thereof by the electric field. Accordingly, as illustrated in  FIG. 8 , power transmission efficiency may be uniform in the entirety of the power transmitting coil to enable the power receiving apparatus A to receive uniform power, irrespective of the position of the power receiving apparatus A, resulting in a high degree of position freedom. 
     Intersecting points of dotted lines in  FIG. 8  may indicate the center of the power receiving coil. Even in the case that the center of the power receiving coil is disposed at any position of the power transmitting coil in a similar manner in which the intersecting points are disposed on an entire power transmitting area of the power transmitting coil, wireless power transmission efficiency may be uniform in a range of about 84% to 90%. 
     As described above, according to some exemplary embodiments in the present disclosure, uniform wireless power transmission efficiency may be obtained irrespective of the position of the center of the power receiving coil disposed on the power transmitting coil by forming the intervals of the pattern portions of the power transmitting coil in a non-equidistant manner. 
     As set forth above, according to exemplary embodiments in the present disclosure, the power transmission efficiency may be uniform on the entire power transmitting surface of the non-contact type power supplying apparatus. 
     While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the present invention as defined by the appended claims.