Power transmission equipment and power supply system

Abstract

To provide a transmission device which eliminates a need for highly accurate positioning for transmitting electric power in a non-contact manner, and to provide a power supply system.SOLUTION: According to an embodiment, a transmission device includes: a power transmission antenna; and a power transmission circuit. The power transmission antenna outputs micro waves to reception antennas of power reception devices respectively provided at a plurality of housings which are stored arranged in a predetermined direction at a storage space. The power transmission circuit causes the power transmission antenna to output micro waves for power supply for supplying electric power to the power reception device, which is considered as a power supply object, of the power reception devices provided at the housing stored in the storage space.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Embodiments of the present invention relate to a power transmission device and a power supply system.

Background Art

[0002] In recent years, systems have been devised that provide various services by mounting electronic devices on carts (moving trolleys) such as shopping carts operated by users. A battery for supplying power to the electronic device is mounted on the cart. As a power supply system for supplying power to charge the battery mounted on the cart, a non-contact power transmission technology for non-contact power supply to the cart stored in the storage position is adopted.

[0003] Conventionally, a power supply system for non-contact power supply to a cart often adopts a system that transmits power by magnetic field coupling such as electromagnetic induction or magnetic field resonance. In a power supply system that transmits power non-contact by magnetic field coupling, it is necessary to accurately align the coil on the power transmission side and the coil on the power reception side attached to the cart. In the conventional power supply system, in order to align the positions of the coil on the power transmission side and the coil on the power reception side, a guide rail is provided to guide the cart to a predetermined position by guiding the wheels of the cart. However, when moving the wheels of the cart along the guide rail, there is a problem that the wheels of the cart interfere with the side wall of the guide rail, making it difficult to move the cart in and out.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a power transmission device and a power supply system that do not require high-precision alignment for non-contact power transmission. [Means for solving the problem]

[0006] According to one embodiment, the power transmission device includes a power transmission antenna and a power transmission circuit. The power transmission antenna outputs microwaves to the power receiving antennas of power receiving devices provided in each of a plurality of housings that are arranged in a predetermined direction in a storage location. Multiple antenna elements are arranged in the predetermined direction. The power transmission circuit outputs microwaves from the power transmission antenna to supply power to the power receiving device, which is located in a housing installed in the storage location. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a perspective view showing an example configuration of a cart and cart base equipped with a power supply system consisting of a power transmission device and a power receiving device according to the embodiment. [Figure 2] Figure 2 is a perspective view showing an example of the installation of a power receiving device and a power receiving antenna that receive power from a power transmission device according to the embodiment. [Figure 3] Figure 3 is a block diagram showing an example of the configuration of the control system in a power transmission device and a power receiving device according to an embodiment. [Figure 4] Figure 4 shows an example of the configuration of a power transmission antenna connected to a power transmission device according to an embodiment. [Figure 5] Figure 5 is a diagram illustrating the direction of the beam (radio wave) transmitted from the power transmission antenna connected to the power transmission device according to the embodiment. [Figure 6] Figure 6 is a sequence illustrating an example of operation of a power supply system consisting of a power transmission device and a power receiving device according to the embodiment. [Modes for carrying out the invention]

[0008] The following description of the power supply system, including the power transmission device according to the embodiment, will be given with reference to the drawings. Figure 1 is a perspective view showing an example configuration of a power supply system 1 including a power transmission device 3 according to the embodiment. Figure 2 is a perspective view showing an example configuration of a power receiving device 2 in the power supply system 1 according to the embodiment. The power supply system 1 according to this embodiment comprises a power receiving device 2 and a power transmitting device 3. The power transmitting device 3 transmits power to the power receiving device 2 via microwaves in a non-contact manner. Here, the microwaves are, for example, electromagnetic waves in the 920 MHz band, 2.4 GHz band, or 5.7 GHz band.

[0009] The power receiving device 2 receives power transmitted by microwave from the power transmitting device 3. The power receiving device 2 supplies the received power to the electronic device 4. The electronic device 4 is configured to charge a secondary battery with the power supplied from the power receiving device 2. In the following embodiment, the power supply system 1 is configured such that the power receiving device 2 is installed on the cart 5, and the power transmitting device 3 is installed to transmit power to the power receiving device 2 installed on the cart 5.

[0010] As shown in Figure 1, the cart 5 with the power receiving device 2 attached is stored in a storage area formed by the cart base 6. Multiple carts 5 are stored in the cart base 6 in a nested manner in a predetermined direction. In the configuration example shown in Figure 1, the power transmission device 3 is installed in the cart base 6 that houses the carts 5 with the power receiving device 2 attached.

[0011] The cart base 6 comprises a front bar 32, a pole 33, side bars 34, and an upper frame 35. The front bar 32, pole 33, and side bars 34 form a storage area for accommodating multiple carts 5.

[0012] The front bar 32 is connected to the pole 33 and defines the leading position of the front cart 5 that is stored in the storage area. The pole 33 is a pair of poles erected from both sides of the storage area. The side bars 34 define the positions of both sides of each cart 5 that is stored in the storage area.

[0013] The side bars 34 are positioned at a predetermined height on both edges of the storage area. The side bars 34 are structures that extend in the direction of movement of the cart 5 within the storage area (the direction of the cart's forward and backward movement). That is, the cart 5 moves forward and backward within the storage area along the direction in which the side bars 34 extend.

[0014] The upper frame 35 is a support member that supports the power transmission antenna 31. The upper frame 35 is installed above the storage location. The upper frame 35 is joined to the pole 33 at a predetermined height corresponding to the height of the cart 5, and is formed to extend upward from the joint with the pole 33 to the storage location. As shown in Figure 1, the power transmission device 3, which includes the power transmission antenna 31, and the motion sensor 36 are installed on the upper frame 35. The power transmission device 3 only needs to be installed on the frame 35 or the like with the power transmission antenna 31 facing the power receiving device 2. For this reason, the circuit section of the power transmission device 3 may be placed in a different location from the power transmission antenna 31 (for example, on the floor). Furthermore, a configuration in which the power transmission antenna 31 and the circuit section of the power transmission device 3 are installed separately can be achieved by connecting them with a coaxial cable or the like.

[0015] The power transmission antenna 31 is installed to transmit power to the power receiving devices 2 installed in each cart 5, which are stored in a nested arrangement in the storage area. The power transmission device 3 only needs to be installed in a way that it can supply power from the power transmission antenna 31 to the power receiving devices 2 of the carts 5 stored in the storage area. For example, the power transmission antenna 31 is not limited to being installed above the carts 5 stored in the storage area, but may also be installed below the carts 5 stored in the storage area (for example, on the floor). Alternatively, the power transmission antenna 31 may be installed on the side of the carts 5 stored in the storage area.

[0016] The human presence sensor 36 detects a person present in the storage location and the vicinity of the storage location. The human presence sensor 36 detects a person attempting to store the cart 5 in the storage location and a person attempting to remove the cart 5 from the storage location. The human presence sensor 36 may be any sensor capable of detecting a person. For example, the human presence sensor 36 may be an optical sensor such as an infrared sensor, or may be a sensor that detects the weight of a person on the floor surrounding the storage location and the storage location. Alternatively, it may be a sensor system that uses a camera and utilizes image processing for person detection.

[0017] The cart 5 is a mobile object, for example, a shopping cart. As shown in FIG. 1, the cart 5 has a frame 11, a basket portion 12, front wheel casters 13, rear wheel casters 14, and electronic equipment 4. In the configuration example shown in FIG. 2, the electronic equipment 4 provided on the cart 5 has a power receiving device 2 and a power receiving antenna 21 attached thereto. The electronic equipment 4 includes a charging circuit and a secondary battery, and is a device that charges the secondary battery with the power supplied from the power receiving device 2.

[0018] The frame 11 is configured by assembling a plurality of frame members extending in different directions. The frame 11 supports the basket portion 12, the front wheel casters (a pair of front wheel casters) 13, the rear wheel casters (a pair of rear wheel casters) 14, and the electronic equipment 4 at respective predetermined positions.

[0019] The frame 11 includes, for example, a pair of left and right vertical frame portions 111, a lower frame portion 112, a horizontal frame portion 113, a handle portion 114, and a mounting frame 115. The vertical frame portion 111, the lower frame portion 112, and the horizontal frame portion 113 extend in directions intersecting each other.

[0020] The vertical frame portion 111 includes a pair of main frames extending upward from the rear wheel casters 14 and sub-frames provided on the rear side and the front side of the main frames, respectively. The vertical frame portion 111 extends vertically behind the basket portion 12, and the rear wheel casters 14 are disposed at the lower end portion.

[0021] The lower frame section 112 comprises a plurality of frame members arranged along the floor surface. The lower frame section 112 comprises, for example, a pair of main frames, a support frame, and a front connecting section. The main frames of the lower frame section 112 extend forward from the rear wheel caster 14 toward the front wheel caster 13. The front connecting portion of the lower frame 112 extends in the width direction at the front end of the lower end of the cart 5, connecting the front ends of the pair of main frames.

[0022] The support frame of the lower frame section 112 extends downward from the horizontal frame section 113, bends forward at a predetermined height, extends forward, and its front end bends upward. The support frame of the lower frame section 112 is composed of, for example, a U-shaped frame member that curves and folds back at the front. In the lower frame section 112, the support frame extends along a plane parallel to the floor surface inside the main frame. The support frame of the lower frame section 112 also forms a basket storage area on its upper side.

[0023] The horizontal frame section 113 comprises multiple link frames that extend in the width direction, spanning between the left and right vertical frame sections 111. The handle portion 114 is positioned above the rear end of the cart 5. The handle portion 114 is positioned continuously with the upper end of the vertical frame portion 111. For example, the handle portion 114 extends in the width direction. The mounting frame 115 is connected to the vertical frame portion 111. The mounting frame 115 extends, for example, above one of the vertical frame portions 111 and supports the electronic device 4.

[0024] In the frame 11, the basket section 12 is supported by the vertical frame section 111. Front wheel casters 13 and rear wheel casters 14 are provided at the front and rear ends of the lower frame section 112, which is located below the basket section 12.

[0025] The basket section 12 is constructed in a box shape with an upward opening, for example, using perforated panel members or mesh-like wire members. The basket section 12 is formed to be able to accommodate goods or to accommodate a shopping basket for accumulating goods. The basket section 12 is positioned in front of the vertical frame section 111, at a height that is raised above the floor surface. The left and right sides of the rear end of the basket section 12 are supported by the vertical frame section 111.

[0026] Furthermore, the pair of main frames in the lower frame section 112 extend diagonally towards the center at the front, such that the spacing between them in the width direction at the front is narrower. Therefore, the frame 11 is formed with a narrower width at the front and a wider width at the rear in the forward direction of the cart 5.

[0027] The front caster 13 and rear caster 14 each consist of a wheel that rotates in the direction of movement and a bracket that rotatably supports the wheel. The bracket is rotatably mounted to the frame 11. The cart 5 moves as the wheels of the front caster 13 and rear caster 14 rotate on the floor surface. In addition, the direction of travel of the cart 5 can be changed by rotating the brackets of the front caster 13 and rear caster 14.

[0028] Similar to the shape of the frame 11 and the basket section 12, the front wheel casters 13 are positioned so that they are narrower in width from side to side than the rear wheel casters 14. Therefore, when multiple carts 5 are stored in a row, the frame 11 of the rear cart 5 can be stored so that it overlaps with the frame 11 of the front cart 5.

[0029] Electronic device 4 is an information terminal such as a tablet device for providing information to the user. Electronic device 4 may also be equipped with a product reader to acquire information about products selected by the user. Electronic device 4 includes, for example, a secondary battery 42 (see Figure 3). Electronic device 4 is powered by the secondary battery 42. Furthermore, electronic device 4 may be configured to supply power from the secondary battery 42 to electronic devices owned by the user (e.g., mobile phones, smartphones, digital cameras, etc.).

[0030] In the configuration examples shown in Figures 1 and 2, the power receiving device 2 and the power receiving antenna 21 are attached to the electronic device 4. In the configuration example shown in Figure 2, the power receiving antenna 21 is attached to the back of the tablet terminal, which is the electronic device 4 (the side opposite to the display surface). The power receiving device 2 is attached to the back of the tablet terminal, which is the electronic device 4, and is connected to the power receiving antenna 21. Furthermore, the power receiving device 2 is connected to the electronic device 4 and supplies power generated from the radio waves (microwaves) received by the power receiving antenna 21 to the electronic device 4.

[0031] Furthermore, the power receiving device 2 and the power receiving antenna 21 can be attached to the cart 5, and are not limited to being attached to the electronic equipment 4. For example, the power receiving antenna 21 can be attached to the cart 5 in a position and orientation that makes it easy to receive microwaves output from the power transmitting antenna of the power transmitting device 3. For example, the power receiving antenna 21 may be installed below the cart 5 or on the side of the cart. The power receiving device 2 can be installed anywhere on the cart 5 as long as it is connected to the power receiving antenna 21 and the electronic equipment 4.

[0032] Next, the configurations of the power transmission device 3, power receiving device 2, and electronic equipment 4 according to this embodiment will be described. Figure 3 is a block diagram showing an example of the configuration of the control system in the power transmission device 3, power receiving device 2, and electronic device 4 according to the embodiment. First, let's explain an example of the configuration of the power transmission device 3. In the configuration example shown in Figure 3, the power transmission device 3 comprises a processor (control unit) 51, a power transmission circuit 52, a communication circuit 53, and an interface (I / F) 54. For example, the power transmission device 3 includes a housing that accommodates a circuit board on which the electronic components constituting each circuit and interface, and the wiring patterns electrically connecting them, are mounted.

[0033] The power transmission circuit 52 is connected to the power transmission antenna 31. In this embodiment, the power transmission device 3 has a plurality of power transmission circuits 52, and each power transmission circuit 52 is connected to the power transmission antenna 31. Each power transmission circuit 52 generates power to be transmitted based on power supplied from an external power source or the like. The power transmission circuit 52 outputs the generated power as microwaves from the power transmission antenna 31. The power transmission antenna 31 outputs microwaves to the power receiving device 2 according to the power supplied from the power transmission circuit 52.

[0034] Furthermore, the power transmission circuit 52 directs the beam toward the receiving antenna by controlling the phase and amplitude of the radio waves output from the power transmission antenna 31 according to information from the control unit 51. For example, the power transmission circuit 52 controls the phase and amplitude of the microwaves output from the power transmission antenna 31 so that the power received by the power receiving device 2 is increased, depending on the position of the receiving antenna 21 that the control unit 51 identifies as the target of power supply. This allows the control unit 51 to set the direction of the microwaves (power supply beam) transmitted from the power transmission circuit 52 to the power transmission antenna 31 according to the position and orientation of the receiving antenna 21. An example of the configuration of the power transmission antenna 31 will be described in detail later.

[0035] The communication circuit 53 is a communication interface for communicating with the power receiving device 2. The communication circuit 53 only needs to be capable of data communication with the power receiving device 2. For example, the communication circuit 53 may be a communication interface for short-range wireless communication, or a communication interface for wireless LAN wireless communication. Furthermore, the communication circuit 53 may be included in the power transmission circuit 52, and data transmission and reception may be performed using the power transmission antenna 31.

[0036] Interface 54 connects to a motion sensor 36. The motion sensor 36 connected to interface 54 is a sensor that detects people. The motion sensor 36 outputs a signal indicating whether or not a person is present within a predetermined detection range. Here, the predetermined detection range is defined as the area where the transmission of microwaves from the power transmission device 3 should be stopped. For example, the motion sensor 36 can be set as the detection range of an area where the strength of the microwaves transmitted from the power transmission antenna 31 can exceed a predetermined value. In this embodiment, the motion sensor 36 is set as the detection range of the storage area where the cart 5 to which the power receiving device 2 is attached is stored and the vicinity of the storage area.

[0037] The processor (control unit) 51 is responsible for controlling the power transmission device 3. The control unit 51 controls the operation of the power transmission circuit 52 and the communication circuit 53. The control unit 51 also acquires detection signals from the human presence sensor 36 connected via the interface 54. The control unit 51 consists of a processor, memory, and interface. In the control unit 51, the processor performs various processes by executing programs stored in the memory. The memory stores programs and control data, etc.

[0038] For example, the control unit 51 selects the receiving antenna 21 to be powered based on information received from the power receiving device 2 via the communication circuit 53. The control unit 51 also estimates the power receiving status at the power receiving device 2 based on information received from the power receiving device 2 via the communication circuit 53. The control unit 51 controls the power transmission circuit 52 according to the receiving antenna 21 to be powered and the power receiving status at the power receiving device 2. The control unit 51 may also perform authentication processing to confirm whether the power receiving device 2 is a legitimate power receiving device 2.

[0039] Furthermore, the control unit 51 determines whether or not a person is present in a predetermined area based on the detection signal from the human presence sensor 36 acquired via the interface 54. For example, the control unit 51 determines whether or not a person is present in or near the storage location of the cart 5 based on the detection signal from the human presence sensor 36. If a person is present in a predetermined detection range including the storage location, the control unit 51 stops the output of microwaves for power transmission from the power transmission antenna 31 by the power transmission circuit 52.

[0040] Next, we will describe an example configuration of the power receiving device 2. The power receiving device 2 is connected to the power receiving antenna 21. In the configuration example shown in Figure 3, the power receiving device 2 includes a processor (control unit) 61, a rectifier circuit 62, a voltage conversion circuit 63, a communication circuit 64, and a display unit 65. For example, the power receiving device 2 includes a housing that accommodates a circuit board on which electronic components constituting each circuit and interface and wiring patterns electrically connecting them are mounted.

[0041] The rectifier circuit 62 and the voltage conversion circuit 63 constitute a power receiving circuit that generates power (received power) from microwaves received by the power receiving antenna 21. The rectifier circuit 62 is connected to the power receiving antenna 21. The rectifier circuit 62 converts the microwaves received by the power receiving antenna 21 into DC power by rectifying them. The rectifier circuit 62 is connected to the voltage conversion circuit 63. The rectifier circuit 62 outputs the received power generated from the microwaves received by the power receiving antenna 21 as a DC voltage to the voltage conversion circuit 63.

[0042] The voltage conversion circuit 63 converts the DC voltage output from the rectifier circuit 62 into a desired DC voltage. For example, the voltage conversion circuit 63 generates a voltage to be output to the charging circuit 41 of the electronic device 4 and a voltage to be output to the control unit 61. The voltage conversion circuit 63 includes a circuit that converts the DC voltage supplied from the rectifier circuit 62 into a DC voltage suitable for charging. The voltage conversion circuit 63 outputs a DC voltage suitable for charging to the charging circuit 41 of the electronic device 4. The voltage conversion circuit 63 also includes a circuit that converts the DC voltage supplied from the rectifier circuit 62 into a DC voltage suitable for the operation of the control unit 61. The voltage conversion circuit 63 outputs a DC voltage suitable for the operation of the control unit 61 to the control unit 61.

[0043] The communication circuit 64 is a communication interface for communicating with the power transmission device 3. The communication circuit 64 only needs to be capable of data communication with the power transmission device 3. For example, the communication circuit 64 may be a communication interface for short-range wireless communication, or a communication interface for wireless LAN wireless communication. Furthermore, the communication circuit 64 may be included in the power transmission circuit 52, and data transmission and reception with the power transmission device 3 may be performed using the receiving antenna 21.

[0044] The display unit 65 displays the status of the power receiving device 2 or the electronic device 4. The display content of the display unit 65 is controlled by the control unit 61. For example, the display unit 65 is composed of a light-emitting device such as an LED or a display device such as a liquid crystal. The display unit 65 displays the power receiving status or the power receiving status of the secondary battery 42 in the electronic device.

[0045] The control unit 61 controls the power receiving device 2. The control unit 61 is connected to the communication circuit 64 and performs data communication with the power transmitting device 3. The control unit 61 is also connected to the display unit 65 and controls the display state of the display unit 65. The control unit 61 also has an interface for connecting to the electronic device 4 and has the function of performing data communication with the electronic device 4. The control unit 61 is composed of processing circuits including a processor and memory. In the control unit 61, the processor performs various processes by executing programs stored in the memory. The memory stores programs and control data.

[0046] For example, the control unit 61 determines (estimates) the state of the power receiving device 2 and transmits information indicating the state of the power receiving device 2 to the power transmitting device 3 via the communication circuit 64. The control unit 61 also communicates with the electronic device 4 and determines (estimates) the state of the electronic device 4, such as the charge state of the secondary battery 42. The control unit 61 transmits information indicating the state of the electronic device 4, such as the charge state, to the power transmitting device 3 via the communication circuit 64.

[0047] Next, we will describe an example configuration of electronic device 4. In the configuration example shown in Figure 3, the electronic device 4 includes a charging circuit 41, a secondary battery 42, a control unit 43, and a display unit 44. The electronic device 4 is powered by a power receiving device 2. For example, the electronic device 4 is connected to the power receiving device 2 via a cable for transmitting and receiving power and control information.

[0048] The charging circuit 41 charges the secondary battery 42 using power supplied from the power receiving device 2. The charging circuit 41 supplies the power supplied from the voltage conversion circuit 63 of the power receiving device 2 to the secondary battery 42 as charging power. For example, the charging circuit 41 converts the power supplied from the power receiving device 2 into charging power with current and voltage values ​​used to charge the secondary battery 42 and supplies it to the secondary battery 42.

[0049] The secondary battery 42 is charged by the charging power supplied from the charging circuit 41. The secondary battery 42 stores the power supplied from the charging circuit 41. The secondary battery 42 supplies the stored power to various parts of the electronic device 4 and to devices connected to the electronic device 4. For example, the secondary battery 42 supplies the stored power and a portion of the power supplied from the charging circuit 41 to the control unit 43. Also, if the electronic device 4 is a tablet terminal, the secondary battery 42 supplies power to the display unit 44 of the tablet terminal.

[0050] The control unit 43 is responsible for controlling the electronic device 4. The control unit 43 is a computer equipped with a processor, memory, and various interfaces. The control unit 43 also has an interface for communicating with the power receiving device 2. The control unit 43 controls the operation of the electronic device 4, and also has the function of detecting the state (charge level) of the secondary battery 42 and communicating with the power receiving device 2. The display unit 44 displays information such as the status of the electronic device 4 and applications used when shopping in a store using the cart 5. The display content of the display unit 44 is controlled by the control unit 43. For example, the display unit 44 is composed of a display device such as a liquid crystal.

[0051] In this embodiment, the electronic device 4 is assumed to be a tablet terminal as shown in Figures 1 and 2. The tablet terminal, as the electronic device 4, is a computer equipped with a charging circuit 41, a secondary battery 42, a control unit 43, etc., and has a display with a touch panel as the display unit 44. The tablet terminal, as the electronic device 4, is installed with the display surface facing the user located on the handle unit 114 side.

[0052] The tablet terminal, as electronic device 4, may be connected to a product reader that reads product information. The tablet terminal connected to the product reader displays the product information read by the product reader. The tablet terminal may also perform payment processing for the products read by the product reader. The product reader is, for example, an RFID tag reader that reads RFID tags attached to products being placed in and out of the shopping basket 12. Alternatively, the product reader may be a scanner that reads product identification information such as barcodes attached to products.

[0053] Furthermore, the electronic device 4 may be any device that includes a charging circuit 41, a secondary battery 42, and a control unit 43, and is not limited to a tablet device. For example, the electronic device 4 may be a battery (power supply device) that includes a charging circuit 41, a secondary battery 42, and a control unit 43.

[0054] Furthermore, the electronic device 4 may also be an interface device for connecting devices owned by the user (such as smartphones, tablet devices, or mobile phones). The mobile device connected to the interface device as electronic device 4 may perform the same processing as the tablet device described above. In addition, the interface device as electronic device 4 may charge the battery of the device owned by the user. In addition, the interface device as electronic device 4 may supply power for charging a separately provided secondary battery (external battery).

[0055] Next, the configuration of the power transmission antenna 31 connected to the power transmission device 3 according to this embodiment will be described. Figure 4 shows an example of the configuration of a power transmission antenna 31 connected to a power transmission device 3 according to the embodiment. Figure 5 is a diagram illustrating the direction of the beam output from the power transmission antenna 31 connected to the power transmission device 3 according to the embodiment. In the configuration example shown in Figure 4, the power transmitting antenna 31 is composed of multiple antenna elements 311, 312, 313, and 314. The power transmitting antenna 31, composed of multiple antenna elements, may be a microstrip patch antenna made of a substrate. Alternatively, the power transmitting antenna 31, composed of multiple antenna elements, may be an antenna in which the ground pattern and radiating element are made of sheet metal.

[0056] For example, each antenna element 311, 312, 313, and 314 is connected to the power transmission circuit 52. The control unit 51 of the power transmission device 3 controls the amplitude and phase of the power supplied from each power transmission circuit 52 to each antenna element 311, 312, 313, and 314. In this way, the control unit 51 of the power transmission device 3 controls the direction of the microwave (beam) output by the power transmission antenna 31 as a whole.

[0057] In the configuration example shown in Figures 4 and 5, the multiple antenna elements 311, 312, 313, and 314 are arranged in a line along the storage direction (direction of movement of the cart in the storage location) a of the carts 5 that are stored in a row in the storage location. As a result, the control unit 51 can change the direction of the beam output from the power transmitting antenna 31 in the storage direction a of the cart, as shown in Figure 5.

[0058] For example, if multiple carts 5 are stored in the storage location, the control unit 51 will select one power receiving device 2 attached to any of the carts as the target for power supply. The control unit 51 controls the direction of the beam output from the power transmitting antenna 31 so that the power receiving device 2 to be supplied with power can receive maximum power. As a result, the control unit 51 can transmit a large amount of power to a specific power receiving device 2 using the power transmitting antenna 31. Consequently, even without precisely aligning multiple carts 5 in the storage location, the power receiving devices 2 attached to each cart 5 can efficiently receive the power necessary to charge the secondary battery 42 from the power transmitting device 3.

[0059] However, depending on the operation of the power supply system 1, the power transmission device 3 may transmit power simultaneously from the power transmission antenna 31 to multiple power receiving devices 2. For example, if power is transmitted using only the two central antenna elements 312 and 313, the beam can be spread wider than when four antenna elements are used, making it possible to transmit power simultaneously to multiple power receiving devices 2. In this case, the power supplied from the power transmission device 3 to each power receiving device 2 will be smaller. Therefore, the power supply system needs to be designed so that each power receiving device 2 can receive enough power to charge the secondary battery 42 of the electronic device 4. Note that while Figure 4 shows an example where four antenna elements are arranged along the cart's storage direction a, it is not limited to four. For example, it is possible to arrange a total of eight elements in a 2x4 configuration, but considering that the beam will primarily swing along the cart's storage direction a, it is desirable to arrange many antenna elements along the storage direction a.

[0060] Next, the operation of power transmission from the power transmission device 3 to the power receiving device 2 in the power supply system 1 according to this embodiment will be described. Figure 6 is a sequence illustrating an example of operation of a power supply system 1 having a power transmission device 3 and a power receiving device 2 according to the embodiment. As shown in Figure 1, cart 5 is stored in a storage area (cart storage area). The control unit 61 of the power receiving device 2 mounted on cart 5 stored in the storage area communicates with the power transmitting device 3 via a communication circuit 64. For example, the control unit 51 of the power transmitting device 3 outputs a signal via a communication circuit 53 at a predetermined interval to the communication area including the storage area, requesting a response from the power receiving device 2. When the control unit 61 of the power receiving device 2 receives a response request from the power transmitting device 3 via the communication circuit 64, it establishes communication with the power transmitting device 3 by sending a response to the response request.

[0061] If the control unit 61 of the power receiving device 2 needs to charge the secondary battery 42 of the electronic device 4, it sends a power transmission (power supply) request to the power transmission device 3 via the communication circuit 64 (ACT11). When the control unit 51 of the power transmission device 3 receives a power transmission request from the power receiving device 2, it determines whether or not to start transmitting power to the power receiving device 2 and selects the power receiving device to be transmitted to (ACT12). If there are no other power receiving devices 2 that are currently transmitting power or waiting to be transmitted, the control unit 51 of the power transmission device 3 starts the power transmission process with the power receiving device 2 as the target.

[0062] Furthermore, the control unit 51 of the power transmission device 3 determines the power transmission order to other power receiving devices 2 if there are other power receiving devices 2 that are currently being supplied with power or are waiting to be supplied with power. For example, if the control unit 51 is currently supplying power to another power receiving device 2, it determines whether or not there are other power receiving devices 2 waiting to be supplied with power. If there are no other power receiving devices 2 waiting to be supplied with power, the control unit 51 starts the power supply process to that power receiving device 2 as soon as the power supply to the power receiving device 2 that is currently being supplied with power is completed. Also, if there are other power receiving devices 2 waiting to be supplied with power, the control unit 51 determines the power transmission order in which to perform the power supply process to that power receiving device 2. Once the power transmission order has been determined, the control unit 51 starts the power supply process to that power receiving device 2 when it is the turn to supply power to that power receiving device 2 according to the power transmission order.

[0063] The power supply order can be determined according to a pre-set rule. For example, the power receiving device 2 of cart 5, which is stored in the storage area later, may be given priority and supplied with power first (to charge the secondary battery of the electronic device). For example, in the configuration shown in Figure 1, carts stored in the storage area are reused in the order they were stored. In this case, by prioritizing the power receiving device 2 of cart 5 that will be reused first, the secondary battery of the electronic device 4 in cart 5 that will be reused can be charged preferentially. Also, when charging the secondary batteries 42 of the electronic device 4 in each cart 5 during times when carts 5 are not in use, such as at night, the power supply order can be set regardless of the storage order of the carts 5.

[0064] When the control unit 51 of the power transmission device 3 selects the power receiving device 2 as the recipient of power, it executes a power transmission preparation process (ACT13). The power transmission preparation process is a process in which the power transmission circuit adjusts (sets) the beam output from the power transmission antenna based on information from the power receiving device 2 (information from the receiving side). As part of the power transmission preparation process, the control unit 51 of the power transmission device 3 notifies the power receiving device 2 of the start of power transmission via the communication circuit 53. When the control unit 61 of the power receiving device 2 receives notification from the power transmission device 3 that power transmission has started, it performs information provision processing to supply power receiving side information related to power receiving settings to the power transmission device 3 via the communication circuit 64 (ACT14). The control unit 61 of the power receiving device 2 then performs information provision processing to provide power receiving side information such as the amount of power received in response to the power transmission device 3's power transmission preparation process.

[0065] For example, in the power transmission preparation process, the control unit 51 of the power transmission device 3 transmits microwaves for power transmission preparation (power transmission setting) from the power transmission antenna 31 to the power receiving device 2 via the power transmission circuit 52. The control unit 61 of the power receiving device 2 acquires the value of received power (voltage after rectification by the rectifier circuit 62) obtained from the microwaves received by the power receiving antenna 21. The control unit 61 of the power receiving device 2 provides the power transmission device 3 with information including the acquired received power value.

[0066] The control unit 51 of the power transmission device 3 adjusts (sets) the beams output from each power transmission antenna 31 so that the received power (voltage) value acquired from the power receiving device 2 is maximized. In other words, the control unit 51 adjusts the direction of the beams output from the power transmission antennas 31 by controlling the amplitude and phase of the microwaves output from each power transmission circuit 52.

[0067] The control unit 51 of the power transmission device 3 terminates the power transmission preparation process when it sets the power received by the power receiving device 2 to its maximum value (voltage). After terminating the power transmission preparation process, the control unit 51 transmits microwaves for power transmission from the power transmission antenna 31 via the power transmission circuit 52 (ACT15).

[0068] The power receiving device 2 receives microwaves for power transmission from the power transmitting antenna 31 using the power receiving antenna 21. The power receiving device 2 receives power from the microwaves received by the power receiving antenna 21 using the rectifier circuit 62 and the voltage conversion circuit 63 (ACT 16). The control unit 61 of the power receiving device 2 charges the secondary battery 42 of the electronic device 4 by supplying the received power to the electronic device 4 (ACT 17). The electronic device 4 charges the secondary battery 42 by supplying the power supplied from the power receiving device 2 to the secondary battery 42 as charging power via the charging circuit 41.

[0069] Furthermore, the control unit 43 of the electronic device 4 monitors the charging status, including the amount of charge, of the secondary battery 42, which is charged by the charging circuit 41, and notifies the power receiving device 2 of the charging status, including the amount of charge. The control unit 61 of the power receiving device 2 determines, based on the information from the electronic device 4, whether the amount of charge of the secondary battery 42 has reached a specified value (fully charged or a predetermined amount of charge).

[0070] The power receiving device 2 and the power transmitting device 3 continue to perform the ACT15-17 process until the charge level of the secondary battery 42 reaches a specified value. That is, the control unit 51 of the power transmitting device 3 continues to supply power to the power receiving device 2 until it receives a power supply stop request from the power receiving device 2. In addition, the control unit 61 of the power receiving device 2 continues to receive power via microwaves from the power transmitting antenna 31 and charge the secondary battery 42 until the charge level of the secondary battery 42 reaches a specified value. The control unit 51 of the power transmitting device 3 may also acquire information such as the power received value from the power receiving device 2 even while supplying power, and adjust the beam transmitted from the power transmitting antenna 31.

[0071] When the charge level of the secondary battery 42 reaches a specified value (ACT 18), the control unit 61 of the power receiving device 2 notifies the power transmission device 3 of a power transmission stop request via the communication circuit 64 (ACT 19). When the control unit 51 of the power transmission device 3 receives a notification of a power transmission stop request, it stops supplying power to the power receiving device 2 (ACT20). After ending the power supply to a power receiving device 2, the control unit 51 of the power transmission device 3 checks whether there is another power receiving device to be supplied with power. If there is another power receiving device to be supplied with power, the control unit 51 of the power transmission device 3 selects one power receiving device from the power receiving devices waiting to receive power and performs the above-described process with the selected power receiving device 2.

[0072] As described above, in the power supply system according to this embodiment, the power transmission device transmits microwaves for power supply from a power transmission antenna installed above the cart stored in the storage area. In response, the power receiving device installed on the cart stored in the storage area receives the microwaves transmitted from the power transmission antenna using a power receiving antenna. The power receiving device supplies the power obtained from the received microwaves to the electronic equipment attached to the cart.

[0073] As a result, the power supply system according to this embodiment can supply power to the power receiving device even when the mobile object is at any position within the storage area, without requiring precise positioning within the storage area. Consequently, the operator can easily store or retrieve mobile objects such as carts to which the power receiving device is attached.

[0074] Furthermore, in the power supply system according to this embodiment, the power transmission device detects when a person approaches a cart stored in a storage area using a motion sensor. When the power transmission device detects that a person has approached a cart stored in a storage area, it stops the output of microwaves from the power transmission antenna.

[0075] This allows the microwave output to be stopped if a person is present in an area where the microwave intensity may exceed a predetermined value, thereby eliminating the effects of microwaves on people. Furthermore, even if there are legal regulations regarding the relationship between microwave output and the distance to people, compliance with these regulations can be ensured by setting the motion sensor according to those regulations.

[0076] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. The following is an appendix to the claims originally filed for this application. [1] A transmitting antenna that outputs microwaves to the receiving antenna of a power receiving device provided on each of several housings that are arranged in a predetermined direction in a storage location, A power transmission device having a power transmission circuit that outputs power supply microwaves from the power transmission antenna to supply power to a power receiving device that is to be powered, among the power receiving devices installed in a housing housed in the aforementioned storage location. [2] Furthermore, the system includes a processor that selects a power receiving device to be supplied with power from a power receiving device installed in a housing housed in the aforementioned storage location, and sets the power transmission circuit according to the selected power receiving device to be supplied with power. [1] The power transmission device described above. [3] The power transmission antenna is an array antenna in which multiple antenna elements are arranged in a predetermined direction that arranges multiple housings to be housed in the storage location. [2] The power transmission device described above. [4] Furthermore, it has a sensor that detects a person approaching the storage location, When the processor detects a person approaching the storage location using the sensor, it stops the output of microwaves for power supply from the power transmission antenna. [2] The power transmission device described above. [5] In a power supply system comprising a power transmission device and a power receiving device attached to a mobile body, The aforementioned power transmission device is A transmitting antenna that outputs microwaves to the receiving antenna of a power receiving device provided on each of several mobile bodies that are stored in a predetermined direction in a storage location, The mobile body stored in the aforementioned storage location has a power transmission circuit that outputs microwaves for power supply from the power transmission antenna to the power receiving antenna of the power receiving device to be powered, among the power receiving devices installed in the mobile body stored in the aforementioned storage location, The power receiving device is A receiving antenna that receives microwaves output from the aforementioned transmitting antenna, A power receiving circuit that supplies power generated from microwaves received by the power receiving antenna to electronic equipment, and has Power supply system. [Explanation of Symbols]

[0077] 1...Power supply system, 2...Power receiving device, 3...Power transmitting device, 4...Electronic equipment, 5...Cart, 6...Cart base, 21...Power receiving antenna, 31...Power transmitting antenna, 36...Human presence sensor, 41...Charging circuit, 42...Secondary battery, 42...Secondary battery, 43...Control unit, 51...Processor (control unit), 52...Power transmitting circuit, 53...Communication circuit, 54...Interface, 61...Processor (control unit), 62...Rectifier circuit, 63...Voltage conversion circuit, 64...Communication circuit, 65...Display unit, 311, 312, 313, 314...Antenna elements.

Claims

1. A transmitting antenna having multiple antenna elements arranged in the predetermined direction to output microwaves to the receiving antenna of a power receiving device provided on each of the multiple housings that are stored in a predetermined direction in a storage location, A power transmission circuit that outputs power supply microwaves from the power transmission antenna to supply power to a power receiving device, which is installed in a housing housed in the aforementioned storage location, and which power receiving device is to be powered. A power transmission device having a power transmission device.

2. Furthermore, the system includes a processor that selects a power receiving device to be supplied with power from a power receiving device installed in a housing housed in the aforementioned storage location, and sets the power transmission circuit according to the selected power receiving device to be supplied with power. The power transmission device according to claim 1.

3. Furthermore, it has a sensor that detects a person approaching the storage location, When the processor detects a person approaching the storage location using the sensor, it stops the output of microwaves for power supply from the power transmission antenna. The power transmission device according to claim 2.

4. In a power supply system comprising a power transmission device and a power receiving device attached to a mobile body, The aforementioned power transmission device is A transmitting antenna having multiple antenna elements arranged in the predetermined direction to output microwaves to the receiving antenna of a power receiving device provided on each of the multiple mobile bodies stored in a predetermined direction in a storage location, The mobile body stored in the aforementioned storage location has a power transmission circuit that outputs microwaves for power supply from the power transmission antenna to the power receiving antenna of the power receiving device to be powered, among the power receiving devices installed in the mobile body stored in the aforementioned storage location, The power receiving device is A receiving antenna that receives microwaves output from the aforementioned transmitting antenna, A power receiving circuit that supplies power generated from microwaves received by the power receiving antenna to electronic equipment, and has Power supply system.

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