JP7570845B2 - Power receiving device, power transmitting device, and power transmitting/receiving system - Google Patents

Description

Embodiments of the present invention relate to a power receiving device, a power transmitting device, and a power transmitting and receiving system.

In recent years, some shopping carts (hereafter referred to as carts) are equipped with electronic devices such as display devices. The electronic devices installed in the cart run on power from a built-in battery or an external battery mounted on the cart. The cart may also be equipped with a power receiving device that wirelessly receives power to charge the battery.

One technology for transmitting power contactlessly (contactless power transmission) is a method in which the power transmitted from the transmitting coil of a power transmitting device is received by the receiving coil of a power receiving device. In this type of contactless power transmission, the positional relationship between the receiving coil and the transmitting coil is important to achieve sufficient power transmission. Therefore, to achieve the optimal positional relationship between the receiving coil mounted on the cart and the transmitting coil fixed to a specified position (charging position), it is necessary to park the cart accurately at the specified charging position.

However, from an operational perspective, it is not easy to ensure that a cart that is freely movable and used by an unspecified number of users stops reliably at a designated storage position. Furthermore, in order to park the cart in an accurate position, it is necessary to guide the cart accurately to a designated charging position by strictly regulating the movement of the cart. For example, if the movement of the cart is regulated by rails that are approximately the same width as the width of the cart's tires, the cart can be guided accurately to the designated position, but this creates the problem that it is difficult for users to move the cart.

JP 2006-101577 A

The problem that this invention aims to solve is to provide a power receiving device, a power transmitting device, and a power transmitting and receiving system that can reliably transmit the required power in a non-contact manner while allowing freedom of movement of a mobile object.

According to an embodiment, the power receiving device includes a first power receiving coil, a second power receiving coil, and a power receiving circuit. The first power receiving coil is provided at a position where the power acquired from the first power transmitting coil increases when the position of the cart is displaced in a first direction from a reference position. The second power receiving coil is provided at a position where the power received from the second power transmitting coil provided at a position different from the first power transmitting coil decreases when the position of the cart is displaced in the first direction from the reference position. The power receiving circuit outputs the power received by the first power receiving coil and the second power receiving coil. The first power receiving coil and the second power receiving coil are provided at a second interval different from the first interval in the first direction on a bottom surface of the cart that is parallel to the floor surface, with respect to the first power transmitting coil and the second power transmitting coil that are arranged side by side at a first interval in the first direction on a floor surface.

FIG. 1 is a perspective view showing a state in which a cart equipped with a power receiving device according to the first embodiment is stored in a storage position in which a power transmitting device is installed. FIG. 2 is a diagram showing the relationship between the cart on which the power receiving device according to the first embodiment is mounted and the power transmitting device provided at the storage position. FIG. 3 is a diagram illustrating an example of a circuit configuration of a power transmission and reception system including a power receiving device and a power transmitting device according to the first embodiment. FIG. 4 is a diagram showing another example of the circuit configuration of the power transmitting and receiving system according to the first embodiment. FIG. 5 is a diagram illustrating a variation in the coupling coefficient between the power receiving coil of the power receiving device and the power transmitting coil of the power transmitting device according to the first embodiment. FIG. 6 is a perspective view showing a state in which a cart equipped with a power receiving device according to the second embodiment is stored in a storage position where a power transmitting device is installed. FIG. 7 is a diagram showing the relationship between a cart equipped with a power receiving device according to the second embodiment and a power transmitting device provided at a storage position. FIG. 8 is a diagram illustrating an example of the positional relationship between a power receiving coil of a power receiving device and a power transmitting coil of a power transmitting device according to the second embodiment. FIG. 9 is a diagram illustrating an example of the positional relationship between a power receiving coil of a power receiving device and a power transmitting coil of a power transmitting device according to the second embodiment. FIG. 10 is a diagram illustrating an example of the positional relationship between a power receiving coil of a power receiving device and a power transmitting coil of a power transmitting device according to the second embodiment.

Hereinafter, a power transmitting and receiving system according to each embodiment will be described with reference to the drawings.
First Embodiment
Fig. 1 is a perspective view showing a shopping cart (hereinafter, also simply referred to as cart) 1 equipped with a power receiving device 2 of the power transmission and receiving system according to the first embodiment stored in a storage position 3 where a power transmitting device 4 is installed. Fig. 2 is an external view of the cart 1 stored in the storage position 3 where a power transmitting device 4 of the power transmission and receiving system according to the first embodiment is installed, as seen from the front side (rear). In the following description, the forward direction shown in Fig. 1 is used as a reference to define the front (rear side), rear (front side), left, and right.

The power transmission and reception (contactless power supply) system according to the first embodiment has a power receiving system (power receiving device) 2 and a power transmission system (power transmission device) 4. The power receiving system 2 receives power transmitted from the power transmission system 4 in a contactless manner. The power transmission system 4 transmits power that can be received by the power receiving system 2. The power receiving system 2 and the power transmission system 4 transmit power in a contactless manner using contactless (wireless) power transmission technology.

Next, the configuration of the cart 1 and the power receiving system 2 mounted on the cart 1 will be described.
The cart 1 is an example of a mobile object equipped with the power receiving system 2. The cart 1 is moved by operation of a user. For example, a shopping cart 1 is operated by a shopper himself/herself and used for shopping, etc. After being used for shopping, etc., the shopping cart 1 is returned (stored) in a predetermined cart storage area, etc.

The cart 1 is stored in a storage position 3 that is used as a cart storage area, etc. The power receiving system 2 of the cart 1 receives power transmitted from the power transmitting system 4 at the storage position. The power transmitting system 4 is configured to transmit power in a non-contact manner to the power receiving system 2 mounted on the cart 1 stored in the storage position 3. In other words, the storage position 3 is a place where power is supplied to the power receiving system 2.

For example, the power receiving system 2 serves as a power supply device that supplies the power received contactlessly to the electronic device 21 attached to the cart 1, and supplies power to a battery. For example, the battery serving as the power supply device of the electronic device 21 is configured to be charged with the power received by the power receiving system 2. Here, the battery charged with the power received by the power receiving system 2 may be an internal battery provided in the electronic device 21. Also, the battery charged with the power received by the power receiving system 2 may be an external battery such as a mobile battery that is mounted on the cart 1 as a device separate from the electronic device 21.

In the configuration example shown in FIG. 1, the cart 1 is configured by attaching electronic devices 21 (211, 212, 213), a power receiving circuit 22, and a pair of power receiving coils 23 (231, 232) to a cart body 11 that can store products and be moved. The power receiving circuit 22 and the pair of power receiving coils 23 constitute a power receiving system 2 as a power receiving device mounted on the cart 1. The electronic devices 21 are attached to the cart 1. The electronic devices 21 are loads connected to the power receiving system 2, and operate using power supplied from the power receiving system 2.

The cart body 11 is configured to store and move products according to the user's operation. The electronic device 21 is a device for providing information and services to the user. The power receiving circuit 22 is stored in a storage box (circuit box) and attached to the cart 1. The power receiving circuit 22 supplies the power received by the power receiving coil 23 to the electronic device 21. The power receiving coil 23 receives power transmitted from the power transmission system 4 in a non-contact manner. The power receiving coil 23 supplies the received power to the power receiving circuit 22. The power receiving circuit 22 and the power receiving coil 23 constitute a power receiving system (power receiving circuit).

The storage box that houses the power receiving circuit 22 may be provided with an external battery, such as a mobile battery, that can be used as a power source for the electronic device 21. In this case, the power receiving circuit 22 may include a charging circuit for charging the battery. The charging circuit included in the power receiving circuit 22 charges the battery with power from the power receiving coil 23. The battery charged by the charging circuit of the power receiving circuit 22 may be configured to supply the charged power to the electronic device 21.

The cart body 11 has a storage basket 12 for storing products. The storage basket 12 is supported by a frame provided with four casters 15 (1512, 1511, 1522, 1521). The four casters 15 are provided at the four corners of the lower part of the frame. Each caster 15 (1512, 1511, 1522, 1521) has front wheels 1312 and 1311 and rear wheels 1322 and 1321 that rotate in the direction of movement. The cart body 11 moves when the wheels 13 of each caster 15 rotate on the floor surface. In addition, each caster 15 is configured so that the rotation direction of the wheels 13 can freely rotate. This allows the cart body 11 to freely change its direction of movement.

A handle 16 is provided on the cart body 11 at the front side of the storage basket 12. The handle 16 is held by the user. For example, the user holds the handle 16 to move the cart body 11. In this embodiment, the direction in which the user pushes the storage basket 12 from the handle 16 held by the user is defined as the forward direction. The front wheels 1312 and 1311 are guided wheels that are guided by the guide base 32 and the left and right guide rails 311, 312 at the storage position 3 described below.

The lower part of the frame, where the four casters 15 are provided at the four corners, is narrower at the front and wider at the rear in the forward direction. For this reason, the casters 1512 and 1511 supporting the front wheels are narrower left and right than the casters 1522 and 1521 supporting the rear wheels. When multiple carts are stored lined up one behind the other, the frames of the rear carts are stored so that they overlap along the frame of the front cart. In this way, the multiple carts stored lined up in the storage position are configured so that the spacing between the front and rear is constant.

In the embodiment, the handle 16 side of the storage basket 12 is referred to as the front side, and the opposite side is referred to as the tip side. The front side of the storage basket 12 has an opening and closing surface 121 that can be opened and closed with the lower end as the free end. The front side of the storage basket 12 is also formed so that the surface on the tip side is smaller than the front side surface that serves as the opening and closing surface 121. As a result, when multiple carts are stored lined up one behind the other, the rear cart pushes up the opening and closing surface 121 of the front cart, so that the storage baskets 12 of the front and rear carts overlap.

The electronic devices 21 (211, 212, 213) are attached to the cart body 11. In the configuration example shown in FIG. 1, the electronic devices 21 are attached to the handle 16 of the storage basket 12. Each electronic device 21 is driven by power from a battery built into any one of the electronic devices 21 or an external battery included in the power receiving circuit 22. For example, the electronic devices 21 are information terminals such as tablet terminals for providing information to users, product readers for acquiring information on products selected by users, or card readers for reading credit cards, membership cards, etc.

In the configuration example shown in FIG. 1, examples of the electronic device 21 include a tablet terminal 211, a product reader 212, and a card reader 213. The tablet terminal 211 is an example of an electronic device that has a built-in battery. The tablet terminal 211 is connected to the product reader 212 and the card reader 213.

The tablet terminal 211 is a computer having a display with a touch panel. The tablet terminal 211 is installed with its display facing the user positioned on the handle 16 side. For example, the tablet terminal 211 displays information about a product read by the product reader 212. The tablet terminal 211 may also perform a payment process for the product read by the product reader 212.

The product reader 212 as the electronic device 21 is a device that reads product information. The product reader 212 may have a display unit that displays the read product information. For example, the product reader 212 is a scanner that reads product identification information such as a barcode attached to a product to be put into or taken out of the storage basket 12. The product reader 212 may also be an ID tag reader that reads an ID tag or the like attached to a product.
The product reader 213 as the electronic device 21 is a card reader for reading a credit card, a membership card, or the like owned by a user.

In addition, the electronic device 21 may be provided with an interface device for connecting a mobile device (smartphone, mobile phone, tablet device, digital camera, etc.) owned by the user instead of the tablet terminal 211. The mobile terminal connected to the interface device as the electronic device 21 may perform the same processing as the tablet terminal 211 described above. The interface device as the electronic device 21 may also be one that charges a battery equipped in the mobile terminal. The interface device as the electronic device 21 may also be one that has a built-in battery, or one that is connected to a separately provided battery.

In the configuration shown in Figs. 1 and 2, a pair of power receiving coils 23 (231, 232) are attached to both the left and right sides of the cart body 11. As shown in Figs. 1 and 2, the pair of power receiving coils 23 (231, 232) contactlessly receive power transmitted from a pair of power transmitting coils 43 (431, 432) arranged on the sides of the cart body 11 stored in the storage position 3.

As shown in FIG. 2, the power receiving coil 231 is attached to the left side surface when the cart body 11 is viewed from the front side. Also, as shown in FIG. 2, the power receiving coil 232 is attached to the right side surface when the cart body 11 is viewed from the front side. The power receiving coils 231 and 232 are, for example, composed of spiral coils.

The power receiving coils 231, 232 may be arranged so that their power receiving surfaces face the power transmitting surfaces of the power transmitting coils 431, 432 that transmit power. The power receiving circuit 22 and the power receiving coils 231, 232 may be configured as one unit. An example of the configuration (circuit configuration) of the power receiving circuit 22 and the power receiving coils 231, 232 will be described in detail later.

The power receiving circuit 22 is provided in a storage box provided in a location that does not interfere with the operation of the cart 1. The power receiving circuit 22 has connectors Cc, Cd (see FIG. 3) for connecting the power receiving coils 231, 232. The power receiving coils 231, 232 attached to the side of the cart body 11 are connected to the connectors Cc, Cd of the power receiving circuit 22. For example, the power receiving coils 231, 232 each have a wire extending from both ends, and a connector for connecting to the power receiving circuit 22 is provided at the tip of the wire. The power receiving coils 231, 232 connect the connectors provided at the tip of the wire to the connectors Cc, Cd of the power receiving circuit 22 through a hole or the like provided in the storage box of the power receiving circuit 22.

Next, the configuration of the storage position 3 will be described.
The storage base 30 is installed on the floor surface and constitutes a storage position (cart parking area, charging position) 3 for the cart 1. The storage base 30 is provided with guide rails 311, 312 that guide the four wheels 13 (1311, 1312, 1321, 1322) of each cart 1, and a guide base 32. The guide base 32 is provided between the left guide rail 311 and the right guide rail 312.

The guide base 32 forms a passage 33 between the left guide rail 311 and the guide base 32, allowing the left front wheel 1311 to pass through. In addition, the guide base 32 forms a passage 34 between the right guide rail 312 and the guide base 32, allowing the right front wheel 1312 to pass through. The passages 33 and 34 may be grooves formed by digging into the storage base 30.

The passages 33 and 34 allow the wheels 1311 and 1312 to pass while restricting the movement of the cart 1 to the forward direction or the opposite direction to the forward direction. The width of the passages 33 and 34 (hereinafter referred to as the rail width) is designed to be wider than the width of the wheels 1311 and 1312 (hereinafter referred to as the wheel width). The smaller the margin m of the rail width relative to the wheel width, the more the movement of the wheels 1311 and 1312 is restricted, making it more difficult for the user to move the cart 1.

Conversely, the larger the margin m of the rail width relative to the wheel width, the greater the freedom of movement of the wheels 1311 and 1312, making it easier for the user to move the cart 1. For example, if the cart 1 is pushed at the entrance to storage position 3 when returning (storing) the cart 1, the momentum of the push will cause the cart 1 to move forward. However, the larger the margin m of the rail width relative to the wheel width, the greater the possibility of the cart 1 shifting in position in the left-right direction. The range of variation in positional deviation in the left-right direction is the range of variation in the distance between the power receiving surface of the power receiving coil 23 and the power transmitting surface of the power transmitting coil 43 on the left and right. Since the range of variation in positional deviation in the left-right direction is the margin m of the rail width relative to the wheel width, the range of variation in the distance between the power receiving surface of the power receiving coil 23 and the power transmitting surface of the power transmitting coil 43 is also the margin m of the rail width relative to the wheel width.

The power receiving system 2 according to this embodiment has a pair of power receiving coils 231, 232 provided on both the left and right sides of the cart 1. The power transmitting system 4 also has a pair of power transmitting coils 431, 432 arranged on the left and right sides to correspond to the left and right power receiving coils 231, 232 mounted on the cart 1 stored in the storage position 3. As a result, in the power transmitting and receiving system according to this embodiment, even if the distance between one power receiving coil 231 (232) and the power transmitting coil 431 (432) becomes large, the distance between the other power receiving coil 232 (231) and the power transmitting coil 432 (431) becomes small.

In addition, stoppers 35 for stopping the wheels are provided at the front ends of the passages 33 and 34. The stoppers 35 determine the stopping position of the front wheels of the cart 1 that is first stored in storage position 3 on the storage base 30. That is, the position in the forward direction of the first cart 1 stored in storage position 3 is determined by the stoppers 35. The positions in the forward and backward directions of the second and subsequent carts 1 stored in a row in storage position 3 are determined by the position of the first cart 1.

The guide rail 311 also functions as a guide for guiding the left rear wheel 1321 in the forward direction. The guide rail 312 also functions as a guide for guiding the right rear wheel 1322 in the forward direction.

In the storage position, the wheels 13 of the carts 1 move along the guide bases 32, and the front and rear carts are stored in an overlapping state. The front surface of the storage basket 12 of the cart 1 is an opening and closing surface 121 that can be opened and closed with the lower end as the free end. The front end surface of the storage basket 12 is smaller than the front surface that serves as the opening and closing surface 121. As a result, when the front end side of the storage basket 12 of the rear cart (the cart to be stored later) 1 is pushed into the opening and closing surface 121 of the front cart (the cart that has been stored first) 1, the opening and closing surface 121 of the front cart is pushed up. When the rear cart 1 is further pushed in while the opening and closing surface 121 of the front cart 1 is pushed up, the storage basket 12 of the rear cart 1 is stored so that it overlaps the storage basket 12 of the front cart 1.

The frame that forms the cart body 11 of each cart 1 is formed so that it is wider at the front and narrower at the tip in the left-right direction relative to the direction of movement along the guide base 32. For this reason, the casters 1512, 1511 that support the front wheels 1312, 11 of the cart 1 are narrower left-right than the casters 1522, 1521 that support the rear wheels 1322, 1321. As a result, when multiple carts are stored lined up one behind the other, the frame of the rear cart 1 is stored so that it overlaps along the frame of the front cart 1.

In the configuration example shown in Figs. 1 and 2, a guide rail is provided to guide the direction of movement of the cart 1. However, the means for guiding the direction of movement of the cart 1 is not limited to a guide rail. For example, the first cart (or equivalent) may be fixed to the storage base 30, and the carts may be stored by connecting them to the fixed cart.

Next, the configuration of the power transmission system 4 will be described.
The power transmission system 4 includes a pair of power transmission coils 43 (431, 432) and a power transmission circuit 42. Each power transmission coil 43 functions as an antenna for power transmission. The pair of power transmission coils 431, 432 are each connected to the power transmission circuit 42. The power transmission circuit 42 controls the transmission of power from each power transmission coil 43. Each power transmission coil 43 (431, 432) outputs power that can be received by the power receiving coil 23 in a non-contact manner by the operation of the power transmission circuit 42.

The pair of power transmission coils 431, 432 are fixed to holding members 411, 412 provided on the left and right sides of the forward direction of the cart 1 stored in storage position 3. The power transmission coils 431, 432 are fixed to the side walls (holding members) 411, 412 in an upright position relative to the floor surface so that the power transmission surface that outputs power faces the power receiving surface of the power receiving coil 23 provided on the side of the cart 1.

For example, the power transmission coils 431, 432 are spiral coils and are attached by bonding to the surfaces of the side walls 411, 412 that face the power receiving coils 231, 232 of the cart 1. The power transmission coil 431 is fixed to the left side wall 411 so that its power transmission surface faces the power receiving surface of the power receiving coil 231 installed on the left side of the cart 1. The power transmission coil 432 that pairs with the power transmission coil 431 is fixed to the right side wall 412 so that it faces the power receiving surface of the power receiving coil 232 installed on the right side of the cart 1.

As described above, multiple carts 1 are stored in storage position 3 so as to be lined up at a predetermined interval in the forward direction. The power transmission coils 431, 432 are attached side by side to the side walls 411, 412 so as to face the power receiving coils 231, 232 of the multiple carts 1 stored at a predetermined interval. In the example shown in FIG. 1, it is assumed that five carts 1 can be stored in storage position 3. For this reason, the power transmission coils 431, 432 for five carts are set side by side at a predetermined interval on the side walls 411, 412.

Power transmission coils 431, the number of which corresponds to the number of carts that can be stored, are arranged at a predetermined interval on the side wall 411 so as to face the power receiving coil 231 on the left side of the stored carts 1. Power transmission coils 432, the number of which corresponds to the number of carts that can be stored, are arranged at a predetermined interval on the side wall 412 so as to face the power receiving coil 232 on the right side of the stored carts 1. The side walls 411, 412 to which the power transmission coils 431, 432 are attached may be configured integrally with the storage base 30, or may be provided separately from the storage base 30.

In the configuration example shown in FIG. 2, the power transmission circuit 42 is mounted inside the housing of the storage base 30. The power transmission circuit 42 receives DC power from an AC adapter (AC/DC conversion circuit) connected to a commercial power source or the like. The power transmission circuit 42 supplies a resonant current to the left power transmission coil 431 and the right power transmission coil 432 that constitute the pair of power transmission coils 43.

The power transmission circuit 42 also has connectors Ca and Cb (see FIG. 3) for connecting the power transmission coils 431 and 432. The power transmission coils 431 and 432 attached to the side walls 411 and 412 are connected to the connectors Ca and Cb of the power transmission circuit 42. For example, the power transmission coils 431 and 432 each have a wire extending from both ends, and a connector is provided at the tip of the wire for connecting to the power transmission circuit 42. The power transmission coils 431 and 432 connect the connectors provided at the tip of the wire to the connectors Ca and Cb of the power transmission circuit 42.

Next, the configuration of a control system of the power transmission and reception system will be described.
FIG. 3 is a diagram showing an example of a circuit configuration of a power transmitting and receiving system including a power receiving system 2 and a power transmitting system 4 according to the embodiment.
First, an example of a circuit configuration of the power receiving system 2 will be described.
The power receiving system 2 includes a power receiving circuit 22 and a pair of power receiving coils 23 (231, 232) connected to the power receiving circuit 22. In the configuration example shown in FIG. 3, the power receiving coil 231 and the power receiving coil 232 are connected in series to the power receiving circuit 22.

In the configuration example shown in FIG. 3, the power receiving circuit 22 includes a connector Cc, a connector Cd, a resonant capacitor 51, a rectifying and smoothing circuit 52, a control circuit 53, a DC/DC conversion circuit 55, and a DC/DC conversion circuit 56. The power receiving circuit 22 is also connected to an electronic device 21 as a load.

The receiving coils 231 and 232 are connected to the connectors Cc and Cd provided in the receiving circuit 22. The connectors Cc and Cd are connected in series within the receiving circuit 22 and connected to the rectifying and smoothing circuit 52. As a result, the receiving coils 231 and 232 connected to the connectors Cc and Cd are connected to the receiving circuit 22 in a serially connected state.

The receiving coils 231, 232 receive the transmitted power from the transmitting coils 431, 432 and supply the received power to the receiving circuit 22. The receiving coils 231, 232 have planar receiving surfaces that receive power. The receiving surfaces of the receiving coils 231, 232 are installed on the left and right side surfaces of the cart body 11 so as to face the transmitting coils 431, 432. The receiving coils 231 and 232 are connected in series and are connected in series or parallel to a receiving resonant capacitor 51 to form a resonant circuit (receiving resonant circuit).

The receiving coils 231 and 232, which serve as a receiving resonant circuit, are electromagnetically coupled to the nearby transmitting coils 431 and 432. In the receiving coil 231, an induced current is generated by the magnetic field output from the transmitting coil 431. In the receiving coil 232, an induced current is generated by the magnetic field output from the transmitting coil 432. The receiving coils 231 and 232 may be configured as a winding structure in which an insulated electric wire is wound, or may be configured by forming a coil pattern on a printed circuit board.

The receiving coils 231, 232 as the receiving resonant circuit supply the received AC power to the rectifying and smoothing circuit 52. In other words, the receiving coils 231, 232 function as an AC power source while receiving AC power from the transmitting coils 431, 432. When using the magnetic resonance method for power transmission, the self-resonant frequency of the receiving resonant circuit as the receiving coils 231, 232 is configured to be approximately the same as the frequency at which the transmitting coils 431, 432 transmit power. This improves the power transmission efficiency when the receiving coils 231, 232 and the transmitting coils 431, 432 are electromagnetically coupled.

The rectifying and smoothing circuit 52 converts the received power supplied from the receiving coils 231 and 232 into power that can be supplied to the electronic device 21 as a load. For example, the rectifying and smoothing circuit 52 rectifies the received power supplied from the receiving coils 231 and 232 and converts it into DC. Such a rectifying and smoothing circuit 52 is realized, for example, by a circuit including a rectifying bridge composed of multiple diodes. In this case, a pair of input terminals of the rectifying bridge are connected to a receiving resonant circuit composed of the receiving coils 231 and 232 and a resonant capacitor 51. The rectifying and smoothing circuit 52 outputs DC power from a pair of output terminals by full-wave rectifying the received power supplied from the receiving coils 231 and 232.

The control circuit 53 controls the on/off operation of a switch 57 provided in front of the DC/DC conversion circuit 56. For example, a MOSFET is used as the switch 57. The control circuit 53 includes a processor and a memory. The processor executes arithmetic processing. The processor performs various processes based on, for example, programs stored in the memory and data used in the programs. The memory stores the programs, data used in the programs, and the like. The control circuit 53 may be configured with a microcomputer and/or an oscillator circuit, etc.

The power receiving system 2 may be provided with a wireless communication circuit for wirelessly communicating with the corresponding power transmitting system 4. For example, the wireless communication circuit is a circuit that performs wireless communication at a frequency different from the frequency of power transmission. The control circuit 53 may control each part by wirelessly communicating with the power transmitting system 4 via the wireless communication circuit. The wireless communication circuit may also use load modulation to perform wireless communication at the same frequency as the frequency of power transmission.

The power receiving circuit 22 may also include a charging circuit for receiving power from a battery connected as a load. In this case, the power received by the power receiving coils 231, 232 is converted into charging power (charging power) in the power receiving circuit 22 and supplied to the battery. For example, the charging circuit converts the power supplied from the power receiving circuit 22 into a direct current (charging power) used to charge the battery. In other words, the charging circuit included in the power receiving circuit 22 converts the power received contactlessly into charging power of a predetermined current value and voltage value for charging the battery and supplies it to the battery.

Next, an example of a circuit configuration of the power transmission system 4 will be described.
The power transmission system 4 includes a power transmission circuit 42 and a pair of power transmission coils 43 (431, 432) connected to the power transmission circuit 42. In the configuration example shown in Fig. 3, the power transmission circuit 42 includes a DC/DC conversion circuit 61, a drive circuit 62, a connector Ca, a connector Cb, a control circuit 64, and a resonance capacitor 66. The power transmission circuit 42 is connected to an AC/DC conversion circuit 60.

The AC/DC conversion circuit 60 is, for example, an AC adapter that connects to a commercial power source. The AC/DC conversion circuit 60 converts AC power from a commercial AC power source into DC power and supplies it to the power transmission circuit 42. In the configuration example shown in FIG. 3, the AC power from the AC/DC conversion circuit 60 is supplied to the DC/DC conversion circuit 61 and the drive circuit 62 in the power transmission circuit 42.

The DC/DC conversion circuit 61 functions as a power supply circuit that converts the DC voltage from the AC/DC conversion circuit 60 into a voltage suitable for the operation of each circuit. For example, the DC/DC conversion circuit 61 generates power for operating the control circuit 64 and supplies it to the control circuit 64.
The drive circuit 62 generates transmission power to be transmitted from the power transmitting coils 431, 432. The drive circuit 62 supplies the generated transmission power to the power transmitting coils 431, 432. For example, the drive circuit 62 generates AC power as the transmission power from DC power by switching based on the control of the control circuit 64.

The power transmission coils 431 and 432 are connected to connectors Ca and Cb provided on the power transmission circuit 42. The connectors Ca and Cb are connected in series and connected to the drive circuit 62. As a result, the power transmission coils 431 and 432 connected to the connectors Ca and Cb are connected to the power transmission circuit 42 in a serially connected state.

The power transmission coils 431, 432 output power that can be received by the power receiving coils 231, 232 according to the power transmission supplied from the power transmission circuit 42. The power transmission coils 431, 432 have a planar power transmission surface for transmitting power. As shown in FIG. 2, the power transmission surface of the power transmission coil 431 is arranged to face the power receiving surface of the power receiving coil 231 attached to the left side of the cart 1. The power transmission surface of the power transmission coil 432 is arranged to face the power receiving surface of the power receiving coil 232 attached to the right side of the cart 1.

The power transmission coil 431 and the power transmission coil 432 connected in series are connected in series or in parallel with the resonance capacitor 46 to form a resonance circuit (power transmission resonance circuit). When AC power is supplied from the drive circuit 62 to the power transmission coils 431 and 432 as the power transmission resonance circuit, they generate a magnetic field according to the supplied AC power. The power transmission coils 431 and 432 may be configured as a winding structure in which an insulated electric wire is wound, or may be configured by forming a coil pattern on a printed circuit board.

The control circuit 64 is a circuit that controls the operation of the drive circuit 62. For example, the control circuit 64 may include a processor and a memory. In this case, the processor executes arithmetic processing. The processor performs various processes based on, for example, programs stored in the memory and data used in the programs. The memory stores programs, data used in the programs, and the like. The control circuit 64 may be configured using a microcomputer, or a combination of a microcomputer and a circuit such as an oscillator circuit.

For example, the control circuit 64 controls the frequency of the AC power output from the drive circuit 62, and controls the on/off operation of the drive circuit 62. The control circuit 64 may also control the drive circuit 62 to switch the power transmission coils 431, 432 between a state in which they generate a magnetic field (power transmission state) and a state in which they do not generate a magnetic field (non-power transmission state). The control circuit 64 may also control the power transmission coils 431, 432 to intermittently generate a magnetic field, thereby changing the timing of power transmission.

The power transmission system 4 may be provided with a wireless communication circuit for wireless communication. For example, the wireless communication circuit is a circuit that performs wireless communication at a frequency different from the frequency of power transmission. The control circuit 64 may control each part by wirelessly communicating with the power receiving system 2 via the wireless communication circuit. The wireless communication circuit may also use load modulation to perform wireless communication at the same frequency as the frequency of power transmission.

FIG. 4 is a diagram showing another example of a circuit configuration of a power transmitting and receiving system including the power receiving system 2 and the power transmitting system 4 according to the embodiment.
The circuit shown in Fig. 4 differs from the circuit shown in Fig. 3 in that the transmitting coils 431, 432 are connected in parallel to the drive circuit 62, and the receiving coils 231, 232 are connected in parallel to the rectifying smoothing circuit 52. The circuit shown in Fig. 4 has the same circuit configuration as that shown in Fig. 3 except for the configuration in which the transmitting coils 431, 432 are connected in parallel to the drive circuit 62 and the configuration in which the receiving coils 231, 232 are connected in parallel to the rectifying smoothing circuit 52, and therefore a detailed description thereof will be omitted.

In the circuit configuration example shown in FIG. 4, in the power transmission circuit 42, the connector Ca and the connector Cb are connected in parallel to the drive circuit 62. Therefore, the power transmission coil 431 connected to the connector Ca and the power transmission coil 432 connected to the connector Cb are connected in parallel to the power transmission circuit 42.

The power transmission coil 431 forms a resonant circuit (power transmission resonant circuit) by being connected in series or parallel to a resonant capacitor 661. The power transmission coil 432, which is paired with the power transmission coil 431, also forms a resonant circuit (power transmission resonant circuit) by being connected in series or parallel to a resonant capacitor 662. That is, the power transmission coils 431 and 432 each form a power transmission resonant circuit and generate a magnetic field according to the AC power supplied from the drive circuit 62.

In the circuit configuration example shown in FIG. 4, in the power receiving circuit 22, the connectors Cc and Cd are connected in parallel to the rectifying and smoothing circuit 52. Therefore, the power receiving coil 231 connected to the connector Cc and the power receiving coil 232 connected to the connector Cd are connected in parallel to the power receiving circuit 22.

The receiving coil 231 forms a resonant circuit (receiving resonant circuit) by connecting a resonant capacitor 511 in series or parallel to the receiving coil 231. The receiving coil 232, which is paired with the receiving coil 231, also forms a resonant circuit (receiving resonant circuit) by connecting a resonant capacitor 512 in series or parallel to the receiving coil 231. That is, the receiving coils 231 and 232 each form a receiving resonant circuit, and each supplies the AC power received from the transmitting coils 431 and 432 to the rectifying and smoothing circuit 52. As a result, the rectifying and smoothing circuit 52 is supplied with the combined power of the power received by the receiving coil 231 and the power received by the receiving coil 232.

In the circuit configuration shown in FIG. 3, the receiving coil 231 and the receiving coil 232 are connected in series. Therefore, the receiving circuit 22 shown in FIG. 3 cannot output received power unless both receiving coils 231, 232 receive power. In contrast, in the circuit configuration shown in FIG. 4, the receiving coil 231 and the receiving coil 232 are connected in parallel. Therefore, the receiving circuit 22 shown in FIG. 4 can output the power received by either one of the receiving coils 231 or 232 even if one of the receiving coils 231 or 232 does not receive power.

Next, a description will be given of a change in the coupling coefficient between the power transmitting coil 43 and the power receiving coil 23 due to a positional shift of the cart 1 on which the power receiving system 2 according to the first embodiment is mounted.
FIG. 5 illustrates a change in the coupling coefficient between the power receiving coils 231, 232 and the power transmitting coils 431, 432 due to a lateral positional shift of the cart 1 in the storage position 3. FIG.
2, the passages 33 and 34 are formed with a margin m relative to the wheel width so that the wheels of the cart 1 can easily pass through. The larger the margin m, the easier it is to move the cart 1. However, the gap between either the power transmitting coil or the power receiving coil increases due to the left-right shift of the cart 1.

The power transmission and reception system according to the first embodiment has a pair of power transmission coils and a pair of power receiving coils on the left and right. That is, when the cart 1 shifts left and right and one of the power transmission coils 431 (432) and the power receiving coil 231 (232) separates, the other power transmission coil 432 (431) and the power receiving coil 232 (231) approach each other. However, if the left and right shift (margin) is too large, the received power may become unstable. For this reason, the margin m may be set based on the characteristics shown in FIG. 5.

In FIG. 5, when the center position of cart 1 in the left-right direction is at center position (reference position) C of guide base 32 (when cart 1 stops at the reference position), the rail position is "3." For example, when wheels 1311, 1312 are in the center positions of aisles 33, 34, the center position of cart 1 in the left-right direction becomes center position (reference position) C of guide base 32.

When the rail position is "3", the coupling coefficient between the power transmission coil 431 installed on the left side of the cart 1 and the power receiving coil 231 attached to the left side of the cart 1 is "0.3". Also, when the rail position is "3", the coupling coefficient between the power transmission coil 432 installed on the right side of the cart 1 and the power receiving coil 232 attached to the right side of the cart 1 is also "0.3". In other words, when the center position of the cart 1 is at the center position C of the guide rail 3, the left and right power receiving coils 231, 232 can receive the same amount of power.

In addition, when the cart 1 is stored shifted to the left from the central position C, the power transmission coil 431 and the power receiving coil 231 on the left side approach each other, and the power transmission coil 432 and the power receiving coil 232 on the right side move away from each other. Therefore, when the cart 1 is stored shifted to the left from the central position C, the coupling coefficient between the power transmission coil 431 and the power receiving coil 231 increases, and the coupling coefficient between the power transmission coil 432 and the power receiving coil 232 decreases.

For example, in the example shown in FIG. 5, when the cart 1 shifts left of the center and the rail position becomes "2", the coupling coefficient between the left power transmission coil 431 and the power receiving coil 231 becomes approximately "0.35", and the coupling coefficient between the right power transmission coil 432 and the power receiving coil 232 becomes approximately "0.25". Furthermore, when the cart 1 shifts further left from the rail position "2" and the rail position becomes "1", the coupling coefficient between the left power transmission coil 431 and the power receiving coil 231 becomes approximately "0.4", and the coupling coefficient between the right power transmission coil 432 and the power receiving coil 232 becomes approximately "0.2".

In addition, when the cart 1 is stored shifted to the right from the central position C, the power transmission coil 431 and the power receiving coil 231 on the left side move away from each other, and the power transmission coil 432 and the power receiving coil 232 on the right side move closer to each other. Therefore, when the cart 1 is stored shifted to the right from the central position C, the coupling coefficient between the power transmission coil 431 and the power receiving coil 231 decreases, and the coupling coefficient between the power transmission coil 432 and the power receiving coil 232 increases.

For example, in the example shown in FIG. 5, when the cart 1 shifts to the right of the center and the rail position becomes "4", the coupling coefficient between the left power transmission coil 431 and the power receiving coil 231 becomes approximately "0.25", and the coupling coefficient between the right power transmission coil 432 and the power receiving coil 232 becomes approximately "0.35". Furthermore, when the cart 1 shifts further to the right from the rail position "4" and the rail position becomes "5", the coupling coefficient between the left power transmission coil 431 and the power receiving coil 231 becomes approximately "0.2", and the coupling coefficient between the right power transmission coil 432 and the power receiving coil 232 becomes approximately "0.4".

As shown in FIG. 5, in the power transmission and receiving system according to the embodiment, even if the cart 1 is shifted to the left or right, the pair of power transmission coils 43 and the pair of power receiving coils 23 can be combined to have a high coupling coefficient and a low coupling coefficient. In other words, even if the power received by one power receiving coil decreases, the power received by the other power receiving coil increases. In the example shown in FIG. 5, when the rail positions are between "1" and "5", the rate of increase (decrease) of the coupling coefficient between the left power transmission coil 431 and the power receiving coil 231 is about the same as the rate of decrease (decrease) of the coupling coefficient between the right power transmission coil 432 and the power receiving coil 232. Therefore, for the power receiving system 2 as a whole, even if the cart 1 is stored biased to the left or right, the necessary non-contact receiving power (e.g., 20 W) can be secured as long as the rail positions are between "1" and "5".

On the other hand, if the position of the cart 1 is shifted further to the left of rail position "1", the coupling coefficient between the approaching power transmission coil 431 on the left side and the power receiving coil 231 becomes higher, but the coupling coefficient between the moving away power transmission coil 432 on the right side and the power receiving coil 232 drops sharply. For example, when the rail position in FIG. 5 is "0", the coupling coefficient between the power transmission coil 432 and the power receiving coil 232 drops sharply, and the received power of the power receiving system 2 as a whole also drops sharply. However, in the power receiving circuit 22 in which the power receiving coil 231 and the power receiving coil 232 shown in FIG. 4 are connected in parallel, the power received by the power receiving coil 231 can be output even if the power receiving coil 232 does not receive power.

In addition, if the position of the cart 1 is shifted further to the right than rail position "5", the coupling coefficient between the separated left transmitting coil 431 and the receiving coil 231 drops sharply. For example, when the rail position in FIG. 5 is "6", the coupling coefficient between the transmitting coil 431 and the receiving coil 231 drops sharply, and the received power of the entire power receiving system 2 also drops sharply. However, in the receiving circuit 22 in which the receiving coil 231 and the receiving coil 232 shown in FIG. 4 are connected in parallel, the receiving coil 232 can output the received power even when the receiving coil 231 is not receiving power.

Therefore, in the power transmission and reception system according to the embodiment, it is desirable to design the rail width of the passages 33 and 34 within a range in which the received power does not suddenly drop. For example, according to the characteristics shown in FIG. 5, the margin m is specified so that the cart 1 fits between rail positions "1" to "5," and the width (rail width) of the passages 33 and 34 is designed.

As described above, the power transmission and reception system according to the first embodiment can form an aisle with a width that allows for a margin that makes it easy to move (store) a cart, and can transmit the necessary power contactlessly even if the cart is stored unevenly to the left or right due to the margin in the width of the aisle. In other words, the power transmission and reception system according to the embodiment can achieve both stable contactless power transmission and ease of loading and unloading the cart when storing it.

Second Embodiment
Next, a power transmitting and receiving system according to a second embodiment will be described.
FIG. 6 is a perspective view showing a state in which the cart 1 on which the power receiving system 2002 of the power transmitting and receiving system according to the second embodiment is mounted is stored in the storage position 3 in which the power transmitting system 2004 is installed.
The power transmission and reception (non-contact power supply) system according to the second embodiment differs from the power transmission and reception system according to the first embodiment in the arrangement of the power transmission coil and the power reception coil. The configuration of the power transmission and reception system shown in Fig. 6 differs from the configurations shown in Figs. 1 and 2 in the arrangement of the power transmission coils 2431 and 2432 and the arrangement of the power reception coils 2231 and 2232.

The configuration of the power transmission and reception system shown in FIG. 6 is the same as that described in the first embodiment, except for the arrangement of the power transmission coil and the power receiving coil and the configuration for arranging the power transmission coil and the power receiving coil, and therefore the same parts are given the same reference numerals and detailed descriptions are omitted. Also, the power receiving circuit 22 and the power transmission circuit 42 shown in FIG. 6 and FIG. 7 are realized by the circuit configuration shown in FIG. 3 or FIG. 4, and the same reference numerals are given and detailed descriptions are omitted.

6 and 7, the arrangement of the pair of power receiving coils 2231, 2232 in the power receiving system (power receiving device) 2002 is different from the arrangement of the pair of power receiving coils 231, 232 shown in FIGS. 1 and 2. The power receiving coils 2231, 2232 of the power receiving system 2 according to the second embodiment are attached side by side on the bottom surface of the cart 1 so as to be parallel to the floor surface on which the cart 1 travels.

In addition, the arrangement of the pair of power transmission coils 2431, 2432 in the power transmission system (power transmission device) 2004 differs from the arrangement of the pair of power transmission coils 431, 432 shown in Figures 1 and 2. The power transmission coils 2431, 2432 of the power transmission system 2004 according to the second embodiment are installed on the guide base 32 so as to face the power receiving coils 2231, 2232 attached to the bottom surface of the cart 1.

As shown in FIG. 7, the power receiving coils 2231 and 2232 are attached to the cart 1 so that their power receiving surfaces are parallel to the power transmitting surfaces of the power transmitting coils 2431 and 2432 installed on the guide base 32. The power receiving coils 2231 and 2232 are arranged side by side in the left-right direction with a power receiving coil pitch (second interval) Pr between them.

The power transmission coils 2431, 2432 are installed on the guide base 32 side by side so that the power transmission surface is parallel to the bottom surface of the cart 1. The power transmission coils 2431 and 2432 are arranged side by side in the left-right direction with a power transmission coil pitch (first interval) Pt that is different from the power receiving coil pitch Pr. The power receiving coil pitch Pr and the power transmission coil pitch Pt are configured to be different sizes.

8, 9, and 10 are diagrams showing examples of the positional relationship between a power receiving coil and a power transmitting coil in a power transmitting and receiving system according to the second embodiment.
8 and 9 are diagrams showing an example in which the power transmitting coil pitch Pt is smaller than the power receiving coil pitch Pr (Pt<Pr).
8 and 9, the two paired power transmitting coils 2431, 2432 are arranged symmetrically with respect to the center position (reference position) in the left-right direction of the guide base 32. The two paired power receiving coils 2231, 2232 are arranged symmetrically with respect to the center position in the left-right direction on the bottom surface of the cart 1. Here, the power transmitting surface of each of the power transmitting coils 2431, 2432 and the power receiving surface of each of the power receiving coils 2231, 2232 are assumed to be the same size.

Figure 8 shows the positional relationship between the power transmission coils 2431, 2432 and the power receiving coils 2231, 2232 when the cart 1 is stored in storage position 3 so that the left-right center position of the cart 1 coincides with the center position (reference position) of the guide base 32 (when the cart 1 is stored in the center (reference position)).

As shown in FIG. 8, when the cart 1 is stored in the center, the power receiving surface of the power receiving coil 2231 faces the power transmitting surface of the power transmitting coil 2431, shifted to the left by half the difference between the power transmitting coil pitch Pt and the power receiving coil pitch Pr ((Pr-Pt)/2). Also, when the cart 1 is stored in the center, the power receiving surface of the power receiving coil 2232 faces the power transmitting surface of the power transmitting coil 2432, shifted to the right by half the difference between the power transmitting coil pitch Pt and the power receiving coil pitch Pr ((Pr-Pt)/2).

That is, when the cart 1 is stored in the center as shown in FIG. 8, the total opposing area between the power receiving surfaces of the power receiving coils 2231 and 2232 and the power transmitting surfaces of the power transmitting coils 2431 and 2432 is reduced in the left-right direction by Pr-Pt. Let us assume that the length in the front-to-rear direction of the power receiving surfaces of the power receiving coils 2231 and 2232 and the power transmitting surfaces of the power transmitting coils 2431 and 2432 is "a", and the area of one surface of the power receiving surfaces and power transmitting surfaces is "A". In this case, the total opposing area in the state shown in FIG. 8 is 2A-(Pr-Pt) x a.

Figure 9 is a diagram showing the positional relationship between the power transmission coils 2431, 2432 and the power receiving coils 2231, 2232 when the cart 1 is stored in storage position 3 with its left-right center position shifted to the right from the center position (reference position) of the guide base 32 (when the cart 1 stops shifted to the right from the reference position). Also, Figure 9 shows a state in which the position of the cart 1 is shifted to the right from the position shown in Figure 8 by half the difference between the power transmission coil pitch Pt and the power receiving coil pitch Pr ((Pr-Pt)/2).

When the cart 1 is stored shifted to the right as shown in FIG. 9, the power receiving surface of the power receiving coil 2231 faces and coincides with the power transmitting surface of the power transmitting coil 2431. When the cart 1 is stored shifted to the right, the power receiving surface of the power receiving coil 2232 faces and is shifted to the right by the difference (Pr-Pt) between the power transmitting coil pitch Pt and the power receiving coil pitch Pr relative to the power transmitting surface of the power transmitting coil 2432.

When the cart 1 is stored shifted to the right as shown in Figure 9, the total opposing area between the power receiving surfaces of the power receiving coils 2231 and 2232 and the power transmitting surfaces of the power transmitting coils 2431 and 2432 is reduced by Pr-Pt. If the length in the front-to-rear direction of the power receiving surfaces of the power receiving coils 2231, 2232 and the power transmitting surfaces of the power transmitting coils 2431, 2432 is "a" and the area of one surface is "A", then the total opposing area in the state shown in Figure 9 is 2A-(Pr-Pt) x a.

In other words, if Pt<Pr, and the left-right misalignment of the cart 1 is within (Pr-Pt), the total area of the opposing power receiving surfaces of the power receiving coils 2231 and 2232 and the power transmitting surfaces of the power transmitting coils 2431 and 2432 can always be maintained at a constant size (in the example above, 2A-(Pr-Pt) x a), as shown in Figures 8 and 9.

FIG. 10 is a diagram showing the positional relationship between the power transmitting surface of each power transmitting coil and the power receiving surface of each power receiving coil in a state in which the cart 1 is stored in the center when Pt>Pr.
8 and 9, the two power transmitting coils 2431, 2432 and the two power receiving coils 2231, 2232 are arranged symmetrically with respect to the center in the left-right direction in Fig. 10. The power transmitting surfaces of the power transmitting coils 2431, 2432 and the power receiving surfaces of the power receiving coils 2231, 2232 are also the same size.

As shown in FIG. 10, when Pt>Pr, when the cart 1 is stored in the center, the power receiving surface of the power receiving coil 2231 faces the power transmitting surface of the power transmitting coil 2431, shifted to the right by half the difference between the power transmitting coil pitch Pt and the power receiving coil pitch Pr ((Pt-Pr)/2). Also, the power receiving surface of the power receiving coil 2232 faces the power transmitting surface of the power transmitting coil 2432, shifted to the left by half the difference between the power transmitting coil pitch Pt and the power receiving coil pitch Pr ((Pr-Pt)/2).

As shown in FIG. 10, if Pt>Pr, when the cart 1 is stored in the center, the total area of the opposing power receiving surfaces of the power receiving coils 2231 and 2232 and the power transmitting surfaces of the power transmitting coils 2431 and 2432 is reduced in the left-right direction by Pt-Pr. Assume that the length in the front-to-rear direction of the power receiving surfaces of the power receiving coils 2231, 2232 and the power transmitting surfaces of the power transmitting coils 2431, 2432 is "a", and the area of one surface of the power receiving surfaces and power transmitting surfaces is "A". In this case, the total opposing area in the state shown in FIG. 10 is 2A-(Pt-Pr)×a, as in the cases of FIG. 8 and FIG. 9.

In other words, when Pt>Pr, just as when Pt>Pr, so long as the misalignment in the left-right direction of the cart 1 is within (Pt-Pr), the total area of the opposing power receiving surfaces of the receiving coils 2231 and 2232 and the power transmitting surfaces of the transmitting coils 2431 and 2432 can always be maintained at a constant size (2A-(Pr-Pt) x a in the above example).

As described above, the power transmission and receiving system according to the second embodiment can always maintain a constant total area where the power receiving surface of each power receiving coil faces the power transmitting surface of each power transmitting coil, so long as the misalignment of the cart 1 in the left-right direction is within the range of the difference between the power receiving coil pitch Pr and the power transmitting coil pitch Pt. In this case, the total area (e.g., 2A-(Pr-Pt) x a) is reduced by the difference between Pr and Pt (e.g., (Pr-Pt) x a). If designed to transmit the required amount of power with such a total area, the power transmission and receiving system according to the second embodiment can always transmit the required power even if the cart 1 is misaligned in the left-right direction.

That is, the power transmission and reception system according to the second embodiment can tolerate left-right misalignment of the cart within the range of the difference between the power receiving coil pitch Pr and the power transmitting coil pitch Pt. In other words, the power transmission and reception system according to the second embodiment can ensure a constant total area of opposing power receiving surfaces and power transmitting surfaces while allowing left-right misalignment of the cart within the range of the difference between the power receiving coil pitch and the power transmitting coil pitch. As a result, it is possible to provide a power transmission and reception system using non-contact power transmission that can ensure a constant amount of received power even when a margin (room) is provided to make it easier to move the cart.

In the above-described first and second embodiments, a shopping cart has been used as an example of a cart equipped with a power receiving device that receives power contactlessly. However, the cart equipped with a power receiving device is not limited to a shopping cart, and may be, for example, a picking cart used in warehouses, etc.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.
The following is an appended summary of the contents of the claims as originally filed.
[1]
A power receiving device mounted on a cart,
a first power receiving coil provided at a position where power acquired from a first power transmitting coil increases when the position of the cart is displaced in a first direction from a reference position;
a second power receiving coil provided at a position where power received from a second power transmitting coil provided at a position different from the first power transmitting coil decreases when the position of the cart deviates from the reference position in the first direction;
a power receiving circuit that outputs the power received by the first power receiving coil and the second power receiving coil;
A power receiving device having the same.
[2]
the first power receiving coil is attached to a first side surface of the cart, and when a position of the cart is displaced from a reference position toward the first side surface, a coupling coefficient between the first power receiving coil and the first power transmitting coil increases;
the second power receiving coil is attached to a second side surface of the cart that is symmetrical to the first side surface, and when a position of the cart is displaced from a reference position toward the first side surface, a coupling coefficient between the second power receiving coil and the second power transmitting coil becomes smaller.
The power receiving device according to [1].
[3]
the first power receiving coil and the second power receiving coil are arranged at a second interval, which is different from the first interval, in the first direction on a bottom surface of the cart that is parallel to the floor surface, with respect to the first power transmitting coil and the second power transmitting coil that are arranged side by side at a first interval in the first direction on a floor surface;
The power receiving device according to [1].
[4]
A power transmitting device that transmits power to a power receiving device mounted on a cart in a non-contact manner,
The power transmitting device is
a first power transmitting coil provided at a position where power received by a first power receiving coil attached to the cart decreases when the position of the cart deviates from a reference position in a first direction;
a second power transmitting coil provided at a position where power received by a second power receiving coil, the second power receiving coil being attached at a different position from a first power receiving coil attached to the cart, increases when the position of the cart is displaced in a first direction from a reference position;
a power transmitting circuit that transmits power from the first power transmitting coil and the second power transmitting coil;
A power transmission device having the above structure.
[5]
A power transmission and reception system including a power receiving device mounted on a cart and a power transmitting device that transmits power to the power receiving device in a non-contact manner,
The power transmitting device is
a first power transmission coil provided at a position facing the cart stopped at a reference position;
a second power transmitting coil provided at a position different from that of the first power transmitting coil;
a power transmitting circuit that transmits power from the first power transmitting coil and the second power transmitting coil,
The power receiving device is
a first power receiving coil provided at a position where power acquired from the first power transmitting coil increases when the position of the cart deviates from a reference position in a first direction;
a second power receiving coil provided at a position where the power received from the second power transmitting coil decreases when the position of the cart deviates from the reference position in the first direction;
A power receiving circuit that outputs the power received by the first power receiving coil and the second power receiving coil.
Power transmission and receiving system.

1... shopping cart (cart), 2... power receiving system (power receiving device), 3... storage position, 4... power transmission system (power transmitting device), 21... electronic device (load), 22... power receiving circuit, 231, 232, 2231, 2232... power receiving coil, 33, 34... passage (rail), 42... power transmitting circuit, 431, 432, 2431, 2432... power transmitting coil.

Claims (3)

A power receiving device mounted on a cart,
a first power receiving coil provided at a position where power acquired from a first power transmitting coil increases when the position of the cart is displaced in a first direction from a reference position;
a second power receiving coil provided at a position where power received from a second power transmitting coil provided at a position different from the first power transmitting coil decreases when the position of the cart deviates from the reference position in the first direction;
a power receiving circuit that outputs the power received by the first power receiving coil and the second power receiving coil;
having
the first power receiving coil and the second power receiving coil are arranged at a second interval, which is different from the first interval, in the first direction on a bottom surface of the cart that is parallel to the floor surface, with respect to the first power transmitting coil and the second power transmitting coil that are arranged side by side at a first interval in the first direction on a floor surface;
Powered device. A power transmitting device that transmits power to a power receiving device mounted on a cart in a non-contact manner,
The power transmitting device is
a first power transmitting coil provided at a position where a power received by a first power receiving coil attached to a bottom surface of the cart that is parallel to a floor surface of the cart decreases when a position of the cart deviates in a first direction from a reference position;
a second power transmitting coil provided at a position where power received by a second power receiving coil attached to a position different from that of the first power receiving coil on the bottom surface of the cart increases when the position of the cart is displaced in a first direction from a reference position;
a power transmitting circuit that transmits power from the first power transmitting coil and the second power transmitting coil;
having
the first power transmitting coil and the second power transmitting coil are arranged side by side on the floor surface at an interval different from an interval between the first power receiving coil and the second power receiving coil in the first direction.
Power transmission equipment. A power transmission and reception system including a power receiving device mounted on a cart and a power transmitting device that transmits power to the power receiving device in a non-contact manner,
The power transmitting device is
a first power transmission coil provided at a position facing the cart stopped at a reference position;
a second power transmitting coil provided at a position different from that of the first power transmitting coil;
a power transmitting circuit that transmits power from the first power transmitting coil and the second power transmitting coil,
The power receiving device is
a first power receiving coil provided at a position where power acquired from the first power transmitting coil increases when the position of the cart deviates from a reference position in a first direction;
a second power receiving coil provided at a position where the power received from the second power transmitting coil decreases when the position of the cart deviates from the reference position in the first direction;
a power receiving circuit that outputs the power received by the first power receiving coil and the second power receiving coil ,
the first power transmitting coil and the second power transmitting coil are arranged side by side at a first interval in the first direction on a floor surface,
the first power receiving coil and the second power receiving coil are provided at a second interval, different from the first interval, from the first power transmitting coil and the second power transmitting coil in the first direction on a bottom surface of the cart that is parallel to the floor surface;
Power transmission and receiving system.