Power supply device, power reception device, and power supply method

Abstract

This power supply device is characterized by comprising: an irradiation unit that irradiates a power reception device with beam light used for power transmission; and a light reception unit that receives a reflection light of the beam light reflected by the power reception device. The power reception device does not reflect the beam light when charging of the power reception device is not completed and reflects the beam light toward the incident direction of the beam light when the charging of the power reception device is completed. The irradiation unit switches whether or not to irradiate the power reception device with the beam light on the basis of the light reception state of the reflection light by the light reception unit.

Description

Power supply device, power receiving device, and power supply method

[0001] The present invention relates to a power supply device, a power receiving device, and a power supply method.

[0002] A technology for wirelessly supplying power using a light beam is known. For example, Patent Document 1 describes a power supply system including: a power supply device including an infrared output unit that irradiates infrared rays, an array antenna that irradiates a light beam used for transmitting power, and a camera that receives the infrared rays; and a power receiving device including a marker that has a reflector that, when irradiated with infrared rays, reflects the infrared rays in the direction in which the infrared rays are incident, and an antenna that, when irradiated with the light beam, receives the power transmitted by the light beam, wherein the power supply device irradiates the light beam from the array antenna to the power receiving device when the camera receives the reflected light.

[0003] Japanese Patent Application Laid-Open No. 2021-136778

[0004] However, according to conventional technology, in addition to a configuration for irradiating a beam of light used for transmitting power, a configuration for irradiating infrared rays is required in the power supply device, which can lead to problems such as an increase in the number of parts in the power supply device, an increase in the size of the power supply device, or a complex configuration of the power supply device.

[0005] The present invention has been made in view of the above-mentioned circumstances, and one of the problems to be solved is to provide a technique that enables a power supply device to be simplified compared to conventional techniques.

[0006] In order to solve the above problems, the power supply device of the present invention comprises an irradiation unit that irradiates a beam of light used for transmitting power onto a power receiving device, and a light receiving unit that receives reflected light of the beam of light reflected by the power receiving device, wherein the power receiving device does not reflect the beam of light when charging of the power receiving device is not complete, and reflects the beam of light in the incident direction of the beam of light when charging of the power receiving device is complete, and the irradiation unit switches whether or not to irradiate the beam of light onto the power receiving device based on the reception status of the reflected light by the light receiving unit.

[0007] Furthermore, the power receiving device according to the present invention is characterized in that it comprises a conversion unit that converts the beam light irradiated from the power supply device into electric power, and a reflection unit that reflects the beam light toward the incident direction of the beam light when the degree of charge of the storage unit that stores the electric power converted by the conversion unit is equal to or greater than a reference value, and does not reflect the beam light when the degree of charge of the storage unit is less than the reference value.

[0008] In addition, the power supply method of the present invention is characterized in that a beam of light used for transmitting power is irradiated from an irradiation unit to a power receiving device, reflected light of the beam of light reflected by the power receiving device is received by a light receiving unit, and based on the reception status of the reflected light by the light receiving unit, whether or not to irradiate the beam of light from the irradiation unit to the power receiving device is switched, and the power receiving device does not reflect the beam of light when charging of the power receiving device is not complete, and does not reflect the beam of light in the incident direction of the beam of light when charging of the power receiving device is complete.

[0009] According to the present invention, it is possible to simplify the power supply device compared to the conventional technology.

[0010] 1 is a block diagram showing an example of the configuration of a power supply system Sys according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing an example of a usage scene of the power supply system Sys. FIG. 3 is a block diagram showing an example of the configuration of a power supply device 1. FIG. 4 is a data structure diagram showing an example of the data structure of power receiving device information DQ. FIG. 5 is an explanatory diagram for explaining examples of a deflection angle Φ1 and a deflection angle Φ2. FIG. 6 is a data structure diagram showing an example of the data structure of power supply setting information DK. FIG. 7 is a block diagram showing an example of the configuration of a power receiving device 2[m]. FIG. 8 is a cross-sectional view showing an example of the configuration of a power receiving device 2[m]. FIG. 9 is a cross-sectional view showing an example of the configuration of a power receiving device 2[m]. FIG. 10 is a cross-sectional view showing an example of the configuration of a retroreflective material 270. FIG. 11 is a timing chart showing an example of a signal generated by the power supply device 1 in an irradiation operation. FIG. 12 is a timing chart showing an example of a signal generated by the power supply device 1 in an irradiation operation. FIG. 13 is a timing chart showing an example of a signal generated by the power supply device 1 in an irradiation operation. FIG. 14 is a timing chart showing an example of a signal generated by the power supply device 1 in an irradiation operation. FIG. 15 is a flowchart showing an example of an irradiation management process. FIG. 16 is a flowchart showing an example of an irradiation management process. Fig. 1 is a block diagram showing an example of the configuration of a power receiving device 2B[m] according to Modification 1 of the present invention. Fig. 2 is a block diagram showing an example of the configuration of a power receiving device 2B[m]. Fig. 3 is a block diagram showing an example of the configuration of a power receiving device 2C[m] according to Modification 1 of the present invention. Fig. 4 is a block diagram showing an example of the configuration of a power receiving device 2C[m].

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that in each drawing, the dimensions and scale of each part are appropriately different from those of the actual parts. Furthermore, the embodiments described below are preferred examples of the present invention, and therefore various technically preferable limitations are applied. However, the scope of the present invention is not limited to these embodiments unless otherwise specified in the following description to the effect that the present invention is limited.

[0012] <A. Embodiment> Hereinafter, an embodiment of the present invention will be described.

[0013] <A. 1. Overview of the Power Supply System Sys> Hereinafter, an overview of the power supply system Sys will be described with reference to FIGS. 1 and 2.

[0014] FIG. 1 is a block diagram showing an example of the configuration of a power supply system Sys.

[0015] As shown in FIG. 1 , the power supply system Sys includes a power supply device 1 and multiple power receiving devices 2. Specifically, in this embodiment, it is assumed that the power supply system Sys includes M power receiving devices 2[1] to 2[M]. Here, the value M is a natural number equal to or greater than 2. In the following, the m-th power receiving device 2 among the M power receiving devices 2[1] to 2[M] included in the power supply system Sys will be referred to as power receiving device 2[m]. Here, the variable m is a natural number satisfying 1≦m≦M.

[0016] The power supply device 1 irradiates each of the plurality of power receiving devices 2 with a light beam LB for wirelessly transmitting power. In this way, the power supply device 1 supplies power to each of the plurality of power receiving devices 2. Here, the light beam LB is light having high directivity. In this embodiment, the light beam LB may be visible light or invisible light.

[0017] In this embodiment, it is assumed that the power supply device 1 can simultaneously irradiate a light beam LB to one power receiving device 2. Specifically, in this embodiment, it is assumed that the power supply device 1 supplies power to M power receiving devices 2[1] to 2[M] one by one in the order of power receiving device 2[1], power receiving device 2[2], ..., power receiving device 2[M].

[0018] FIG. 2 is a diagram illustrating an example of a usage scene of the power supply system Sys.

[0019] 2 , in this embodiment, it is assumed that the power supply system Sys is installed in a supermarket, the power receiving device 2 is an electronic price tag attached to a product shelf 9 in the supermarket, and the power supply device 1 supplies power to the electronic price tag (power receiving device 2) by irradiating the electronic price tag with a light beam LB.

[0020] In this embodiment, the power supply system Sys is assumed to be installed in a supermarket, but the present invention is not limited to this configuration. The power supply system Sys can be installed in various indoor and outdoor facilities where devices that need to be charged are present. For example, the power supply system Sys may be installed in a coffee shop where information processing terminals such as smartphones, tablet terminals, and personal computers that need to be powered are present. In this case, the information processing terminals may be treated as power receiving devices 2 and may be the targets of power supply by the power supply system Sys. Furthermore, for example, the power supply system Sys may be installed in an electric vehicle charging facility where an electric vehicle that needs to be charged is present. In this case, the electric vehicle may be treated as the power receiving device 2 and may be the target of power supply by the power supply system Sys.

[0021] <A. 2. Overview of Power Supply Device 1> Hereinafter, an overview of the power supply device 1 will be described with reference to FIG.

[0022] FIG. 3 is a block diagram showing an example of the configuration of the power supply device 1. As shown in FIG.

[0023] As shown in FIG. 3, the power supply device 1 includes a control device 11, a storage device 12, an irradiation device 13, a light receiving device 14, and a bus 100 that interconnects these devices.

[0024] The storage device 12 is a recording medium readable by the control device 11. The storage device 12 includes, for example, a volatile memory such as a random access memory (RAM) that functions as a work area for the control device 11, and a non-volatile memory such as an electrically erasable programmable read-only memory (EEPROM) that stores various information, and stores power receiving device information DQ, power supply setting information DK, and a control program PG1 for the power supply device 1. The power receiving device information DQ and the power supply setting information DK will be described later.

[0025] The control device 11 (an example of a "control unit") includes a processor. The processor provided in the control device 11 includes, for example, one or more central processing units (CPUs). However, the processor provided in the control device 11 may include hardware such as a graphics processing unit (GPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA) in addition to the one or more CPUs, or in place of some or all of the one or more CPUs. The processor provided in the control device 11 executes a control program PG1 for the power supply device 1 stored in the storage device 12 and operates in accordance with the control program PG1 to control each part of the power supply device 1.

[0026] The irradiation device 13 (an example of an "irradiation unit") irradiates a light beam LB. Specifically, the irradiation device 13 adjusts the irradiation direction of the light beam LB under the control of the control device 11, thereby irradiating the light beam LB toward the power receiving device 2. Note that, hereinafter, the range in which the irradiation device 13 can irradiate the light beam LB is referred to as the irradiatable range. In this embodiment, it is assumed that M power receiving devices 2[1] to 2[M] are arranged so as to be positioned within the irradiatable range.

[0027] The light receiving device 14 (an example of a "light receiving section") receives reflected light LH reflected by the power receiving device 2 out of the light beam LB irradiated from the irradiation device 13 to the power receiving device 2. The light receiving device 14 then outputs a light reception result signal SA indicating the result of receiving the reflected light LH.

[0028] Next, various data stored in the power supply device 1 will be outlined with reference to FIGS. 4 to 6. FIG.

[0029] 4 is a data configuration diagram showing an example of the data configuration of the power receiving device information DQ. Here, the power receiving device information DQ is information about power supply from the power supply device 1 to M power receiving devices 2[1] to 2[M].

[0030] 4, the power receiving device information DQ has M records that correspond one-to-one to the M power receiving devices 2[1] to 2[M] included in the power supply system Sys. Each record of the power receiving device information DQ has device identification information Im and individual device information DQQ[m].

[0031] The device identification information Im is information for identifying each power receiving device 2[m] from among M power receiving devices 2[1] to 2[M] included in the power supply system Sys.

[0032] The individual device information DQQ[m] includes power supply necessity information DQ1[m], non-power supply period information DQ2[m], and power supply target direction information DQ3[m].

[0033] The power supply necessity information DQ1[m] is information indicating whether charging of the power receiving device 2[m] has not been completed, i.e., whether power supply to the power receiving device 2[m] is required. In the present embodiment, as an example, it is assumed that the power supply necessity information DQ1[m] indicates "1" when charging of the power receiving device 2[m] has not been completed and power supply to the power receiving device 2[m] is required, and the power supply necessity information DQ1[m] indicates "0" when charging of the power receiving device 2[m] has been completed and power supply to the power receiving device 2[m] is not required. Hereinafter, when the power supply necessity information DQ1[m] indicates "1" and power supply to the power receiving device 2[m] is required, the power receiving device 2[m] is referred to as a power supply target device 2X. When the power supply necessity information DQ1[m] indicates "0" and power supply to the power receiving device 2[m] is unnecessary, the power receiving device 2[m] is referred to as a power supply unnecessary device 2Y.

[0034] The non-power supply period information DQ2[m] indicates the time elapsed since the charging of the power receiving device 2[m] was completed. Specifically, the non-power supply period information DQ2[m] indicates the time elapsed since the power supply necessity information DQ1[m] changed from "1" to "0." Hereinafter, the elapsed time indicated by the non-power supply period information DQ2[m] will be simply referred to as "elapsed time."

[0035] The power supply object direction information DQ3[m] is information indicating the direction of the power receiving device 2[m] as seen from the power supply device 1. In this embodiment, as an example, it is assumed that the direction of the power receiving device 2[m] as seen from the power supply device 1 is represented by a deflection angle Φ1 and a deflection angle Φ2. In this embodiment, it is assumed that the power supply object direction information DQ3[m] indicates the deflection angle Φ1 and the deflection angle Φ2.

[0036] FIG. 5 is an explanatory diagram for explaining an example of the deflection angle Φ1 and the deflection angle Φ2.

[0037] As shown in FIG. 5 , for the sake of convenience, a power supply device coordinate system is introduced below, which is a coordinate system fixed to the power supply device 1 and has an axis extending in the ξz direction, an axis extending in the ξx direction, and an axis extending in the ξy direction. The ξz direction is the reference irradiation direction of the light beam LB emitted from the irradiation device 13. Here, the reference irradiation direction is, for example, the direction indicating the center of the irradiation range as seen from the irradiation device 13. The ξx direction is a direction perpendicular to the ξz direction, and the ξy direction is a direction perpendicular to the ξz direction and the ξx direction. The deflection angle Φ1 is the angle between the ξz direction and the traveling direction of the light beam LB (hereinafter referred to as the "irradiation direction θB"). The deflection angle Φ2 is the angle between the irradiation direction θB and the ξx direction.

[0038] 6 is a data configuration diagram showing an example of the data configuration of the power supply setting information DK. Here, the power supply setting information DK is information indicating various setting values ​​related to power supply by the power supply device 1 to M power receiving devices 2[1] to 2[M].

[0039] As shown in FIG. 6, the power supply setting information DK includes power supply target number information DM and power supply necessity confirmation information DH.

[0040] The power supply target number information DM is information indicating the number of power supply targets AM. Here, the number of power supply targets AM is the number of power supply target devices 2X that have not yet been charged and require power supply among the M power receiving devices 2[1] to 2[M]. In other words, the number of power supply targets AM is the number of records in which the power supply necessity information DQ1[m] indicates "1" among the M records contained in the power receiving device information DQ.

[0041] The power supply necessity confirmation information DH is information indicating a power supply necessity confirmation interval AH. Here, the power supply necessity confirmation interval AH is an interval at which the power supply device 1 irradiates the power supply unnecessary device 2Y with a light beam LB when charging of the power receiving device 2 is completed and the power receiving device 2 becomes a power supply unnecessary device 2Y. The power supply necessity confirmation interval AH (an example of a "second interval") is an interval longer than the interval at which the power supply device 1 irradiates the power supply unnecessary device 2X with a light beam LB when the power receiving device 2 is a power supply target device 2X (an example of a "first interval"). Note that in this embodiment, it is assumed that the power supply necessity confirmation interval AH is a fixed value.

[0042] <A. 3. Overview of the power receiving device 2[m]> Below, an overview of the power receiving device 2[m] will be described with reference to FIGS. 7 to 10.

[0043] FIG. 7 is a block diagram showing an example of the configuration of the power receiving device 2[m].

[0044] As shown in FIG. 7, the power receiving device 2[m] includes a control device 21[m], a memory device 22[m], a display device 23[m], a communication device 24[m], a power storage device 25[m], a power conversion device 26[m], a reflection device 27[m], and a bus 200 that interconnects these devices.

[0045] The storage device 22[m] is a recording medium readable by the control device 21[m]. The storage device 22[m] includes, for example, a volatile memory such as a RAM that functions as a work area for the control device 21[m], and a non-volatile memory such as an EEPROM that stores various information, and stores a control program PG2 for the power receiving device 2[m].

[0046] The control device 21[m] includes a processor. The processor provided in the control device 21[m] includes, for example, one or more CPUs. However, the processor provided in the control device 21[m] may include hardware such as a GPU, DSP, ASIC, PLD, or FPGA in addition to the one or more CPUs, or in place of some or all of the one or more CPUs. The processor provided in the control device 21[m] executes a control program PG2 for the power receiving device 2[m] stored in the storage device 22[m] and operates in accordance with the control program PG2 to control each part of the power receiving device 2[m].

[0047] The display device 23[m] displays various information. Specifically, in this embodiment, since the power receiving device 2[m] is an electronic price tag, the display device 23[m] displays the names and prices of products sold in the supermarket.

[0048] The communication device 24[m] is hardware for communicating with an external device located outside the power receiving device 2[m] via a network. In this embodiment, the power receiving device 2[m] acquires information related to the product name and price to be displayed on the display device 23[m] from the external device via the communication device 24[m].

[0049] The power storage device 25[m] (an example of a "power storage unit") is, for example, a secondary battery, and stores power used by the power receiving device 2[m]. In this embodiment, the power storage device 25[m] notifies the control device 21[m] of the charge rate of the power storage device 25[m]. The power conversion device 26[m] (an example of a "conversion unit") converts the light beam LB irradiated from the power supply device 1 into electric power.

[0050] The reflecting device 27[m] (an example of a "reflecting unit") is in one of two states, a reflective state and a reflection-suppressing state, under the control of the control device 21[m]. When the reflecting device 27[m] is in the reflective state, the reflecting device 27[m] reflects the light beam LB emitted from the power supply device 1 toward the power supply device 1. When the reflecting device 27[m] is in the reflection-suppressing state, the reflecting device 27[m] does not reflect the light beam LB emitted from the power supply device 1 toward the power supply device 1. Specifically, in this embodiment, when the reflecting device 27[m] is in the reflection-suppressing state, the reflecting device 27[m] moves to a position where it does not intersect with the light beam LB emitted from the power supply device 1, thereby suppressing the reflection of the light beam LB toward the power supply device 1. However, the present invention is not limited to this embodiment. When the reflection device 27[m] is in the reflection-suppressing state, the reflection device 27[m] may reflect the light beam LB emitted from the power supply device 1 in a direction different from that of the power supply device 1. Furthermore, when the reflection device 27[m] is in the reflection-suppressing state, the reflection device 27[m] may absorb the light beam LB emitted from the power supply device 1.

[0051] When the charge rate of the power storage device 25[m] is equal to or greater than a reference value, the control device 21[m] determines that charging of the power storage device 25[m] is complete. In this embodiment, when the charge rate of the power storage device 25[m] is equal to or greater than the reference value, the control device 21[m] controls the reflection device 27[m] so that the reflection device 27[m] is in the reflective state. That is, in this embodiment, when charging of the power storage device 25[m] is complete, the control device 21[m] controls the reflection device 27[m] so that the reflection device 27[m] is in the reflective state. On the other hand, when the charge rate of the power storage device 25[m] is less than the reference value, the control device 21[m] controls the reflection device 27[m] so that the reflection device 27[m] is in the reflection suppression state. That is, in this embodiment, when charging of the power storage device 25[m] is incomplete, the control device 21[m] controls the reflection device 27[m] so that the reflection device 27[m] is in the reflection suppression state.

[0052] 8 and 9 are cross-sectional views showing an example of the configuration of the power receiving device 2[m]. Of these, Fig. 8 is a cross-sectional view showing an example of the configuration of the power receiving device 2[m] when the reflection device 27[m] is in the reflection suppression state. Also, Fig. 9 is a cross-sectional view showing an example of the configuration of the power receiving device 2[m] when the reflection device 27[m] is in the reflection state.

[0053] For ease of explanation, a power receiving device coordinate system is introduced below. The power receiving device coordinate system is a coordinate system fixed to the power receiving device 2[m] and has an axis extending in the X1 direction, an axis extending in the Y1 direction, and an axis extending in the Z1 direction. Here, the Y1 direction is a direction perpendicular to the X1 direction, and the Z1 direction is a direction perpendicular to the X1 and Y1 directions. In the following, the X1 direction and the X2 direction opposite the X1 direction may be collectively referred to as the X-axis direction, the Y1 direction and the Y2 direction opposite the Y1 direction may be collectively referred to as the Y-axis direction, and the Z1 direction and the Z2 direction opposite the Z1 direction may be collectively referred to as the Z-axis direction. In this embodiment, it is assumed that the power receiving device coordinate system is set up so that the light beam LB travels from the Z1 side to the Z2 side. In other words, in this embodiment, it is assumed that the power receiving device coordinate system is set so that the dot product of the irradiation direction θB, which is the direction in which the light beam LB travels, and the Z2 direction is greater than "0".

[0054] As shown in Figures 8 and 9, the power receiving device 2[m] includes the above-mentioned power storage device 25[m], power conversion device 26[m], and reflection device 27[m], as well as a housing 210 that houses these.

[0055] The power conversion device 26[m] is provided on the Z1 side of the power storage device 25[m]. The power supply device 1 irradiates a light beam LB toward the power conversion device 26[m]. The power conversion device 26[m] converts the light beam LB irradiated from the Z1 side of the power conversion device 26[m] into electric power and supplies the electric power to the power storage device 25[m] located on the Z2 side of the power conversion device 26[m].

[0056] The reflecting device 27[m] includes a retroreflective material 270, a support 271, and a reflection suppressing material 272.

[0057] When the light beam LB is irradiated onto the retroreflector 270, the retroreflector 270 retroreflects the light beam LB in the incident direction of the light beam LB. Details of the retroreflector 270 will be described later. The support body 271 supports the retroreflector 270. The reflection suppression material 272 is formed of a material that suppresses reflection of the light beam LB, such as a black sponge, and suppresses the light beam LB from being retroreflected toward the power supply device 1.

[0058] When the power receiving device 2[m] is in the reflection-suppressing state, the reflecting device 27[m] is positioned so that the reflecting device 27[m] and the power conversion device 26[m] do not overlap each other when the power receiving device 2[m] is viewed from the Z1 direction to the Z2 direction in a plan view. For example, as shown in Fig. 8, when the power receiving device 2[m] is in the reflection-suppressing state, the reflecting device 27[m] is positioned on the Y1 side of the power conversion device 26[m]. Furthermore, when the power receiving device 2[m] is in the reflection-suppressing state, the retroreflective material 270 is covered with the reflection-suppressing material 272 when the power receiving device 2[m] is viewed from the Z1 direction to the Z2 direction. Therefore, even if the irradiation range of the beam light LB from the power supply device 1 to the power receiving device 2[m] is a wide area that includes not only the area where the power conversion device 26[m] is installed but also the area on the Y1 side of the power conversion device 26[m], if the power receiving device 2[m] is in a reflection-suppressing state, the beam light LB is not reflected by the retroreflective material 270, and the reflected light LH does not reach the power supply device 1.

[0059] When the power receiving device 2[m] is in the reflective state, the reflecting device 27[m] is positioned so that the retroreflective material 270 of the reflecting device 27[m] and the power conversion device 26[m] overlap each other when the power receiving device 2[m] is viewed from above. For example, as shown in FIG. 9 , when the power receiving device 2[m] changes from the reflection-suppressing state to the reflection state, the retroreflective material 270 of the reflecting device 27[m] slides together with the support 271 to a position where it overlaps with the power conversion device 26[m], and the retroreflective material 270 is positioned so that it covers the power conversion device 26[m]. Furthermore, when the power receiving device 2[m] is in the reflective state, the retroreflective material 270 is not covered by the reflection-suppressing material 272 when the power receiving device 2[m] is viewed from above. Therefore, when the power receiving device 2[m] is in a reflective state, the light beam LB irradiated toward the power conversion device 26[m] is reflected by the retroreflective material 270, and the reflected light LH reaches the power supply device 1. Hereinafter, the traveling direction of the reflected light LH is referred to as the reflection direction θH. Here, the reflection direction θH is the direction opposite to the irradiation direction θB.

[0060] FIG. 10 is a cross-sectional view showing an example of the configuration of the retroreflective material 270.

[0061] As shown in FIG. 10, the retroreflective material 270 includes a spherical portion 2701 , a focal layer 2702 , a reflective layer 2703 , a substrate 2704 , and a protective layer 2705 .

[0062] The spherical portion 2701 is formed from a transparent material such as glass. The spherical portion 2701 has a spherical shape. The focal layer 2702 is disposed on the Z2 side of the spherical portion 2701. The focal layer 2702 is formed from a transparent material having a refractive index different from that of the spherical portion 2701, such as a transparent resin. The reflective layer 2703 is disposed on the Z2 side of the focal layer 2702. The reflective layer 2703 is formed from a light-reflecting material, such as aluminum. The base material 2704 is disposed on the Z2 side of the reflective layer 2703 and supports the reflective layer 2703. The protective layer 2705 is disposed on the Z1 side of the spherical portion 2701. The protective layer 2705 is formed from a transparent material, such as a transparent resin.

[0063] When a light beam LB is irradiated onto the retroreflective material 270, the light beam LB enters the spherical portion 2701 from the protective layer 2705. Then, the light beam LB that has entered the spherical portion 2701 is focused on the focusing layer 2702 due to the lens effect of the spherical portion 2701. The light beam LB is then reflected by the reflective layer 2703, passes through the focusing layer 2702 and the spherical portion 2701 again, and is emitted from the protective layer 2705 to the Z2 side as reflected light LH.

[0064] In this case, the reflection direction θH in which the reflected light LH travels is opposite to the irradiation direction θB in which the light beam LB travels. For example, as shown in Figure 10, when a light beam LB traveling in the irradiation direction θB1 is incident on the retroreflector 270, reflected light LH1 traveling in a reflection direction θH1 opposite to the irradiation direction θB1 is reflected from the retroreflector 270. Furthermore, when a light beam LB2 traveling in the irradiation direction θB2 is incident on the retroreflector 270, reflected light LH2 traveling in a reflection direction θH2 opposite to the irradiation direction θB2 is reflected from the retroreflector 270.

[0065] <A. 4. Operation of Irradiating Light Beam LB by Power Supply Device 1> Hereinafter, with reference to FIGS. 11 to 14, an irradiation operation will be described, which is an operation of irradiating light beam LB from the power supply device 1 to M power receiving devices 2[1] to 2[M].

[0066] 11 to 14 are timing charts showing examples of various signals generated within the power supply device 1 when the power supply device 1 performs an irradiation operation.

[0067] 11 to 14 , when the power supply device 1 performs an irradiation operation, the control device 11 generates a timing control signal S. Here, the timing control signal S is a signal for defining a control period T, which is a period for irradiating one power receiving device 2 with a light beam L. In this embodiment, as an example, it is assumed that the control period T has a predetermined time length. Also, in this embodiment, as an example, it is assumed that the timing control signal S has a plurality of pulses P provided at predetermined time intervals, and the control period T is defined as the period from the start of one pulse P of the timing control signal S to the start of the next pulse P.

[0068] Furthermore, when the power supply device 1 performs an irradiation operation, the control device 11 generates an irradiation period management signal SR. Here, the irradiation period management signal SR is a signal for defining an irradiation period TR, which is a period for irradiating a light beam LB to some or all of the M power receiving devices 2[1] to 2[M]. Hereinafter, the kth irradiation period TR among the operating periods during which the power supply device 1 performs an irradiation operation is referred to as an irradiation period TR-k. Here, the variable k is a natural number greater than or equal to 1.

[0069] Furthermore, when the power supply device 1 performs an irradiation operation, the light receiving device 14 generates a light reception result signal SA. Here, the light reception result signal SA is a signal that indicates the result of reception of the reflected light LH by the light receiving device 14. In this embodiment, as an example, it is assumed that the light reception result signal SA is a signal that becomes high level (H level) when the light receiving device 14 receives the reflected light LH, and becomes low level (L level) when the light receiving device 14 does not receive the reflected light LH.

[0070] Furthermore, when the power supply device 1 performs an irradiation operation, the control device 11 generates a power supply designation signal SB. Here, the power supply designation signal SB is a signal that designates whether or not the irradiation device 13 irradiates the light beam LB. In this embodiment, as an example, it is assumed that the power supply designation signal SB is a signal that becomes high level (H level) when the irradiation device 13 irradiates the light beam LB and becomes low level (L level) when the irradiation device 13 does not irradiate the light beam LB.

[0071] Furthermore, when the power supply device 1 performs an irradiation operation, the control device 11 generates an irradiation control signal SL based on the power supply target direction information DQ3[m]. Here, the irradiation control signal SL is a signal including irradiation control information DL[m]. Furthermore, the irradiation control information DL[m] is a signal that specifies the irradiation direction θB of the light beam LB when the light beam LB is irradiated from the irradiation device 13 to the power receiving device 2[m].

[0072] Prior to the start of each irradiation period TR, the control device 11 determines the time length of the irradiation period TR.

[0073] Specifically, when the irradiation period TR is a restart confirmation-free period TRX, the control device 11 determines the time length of the irradiation period TR based on the number of power supply target devices 2X. More specifically, when the irradiation period TR is a restart confirmation-free period TRX, the time length of the irradiation period TR is set to "TS*AM," which is the time length of the control period TS multiplied by the number AM of power supply targets. Here, the restart confirmation-free period TRX is an irradiation period TR during which the light beam LB is irradiated only to the power supply target device 2X among the M power receiving devices 2[1] to 2[M], and the light beam LB is not irradiated to the power supply non-requiring device 2Y among the M power receiving devices 2[1] to 2[M].

[0074] On the other hand, when the irradiation period TR is the resumption confirmation period TRY, the control device 11 determines the duration of the irradiation period TR based on the number of power receiving devices 2 included in the power supply system Sys. More specifically, when the irradiation period TR is the resumption confirmation period TRY, the control device 11 sets the duration of the irradiation period TR to "TS*M," which is M times the duration of the control period T S . Here, the resumption confirmation period TRY is the irradiation period TR during which the light beam LB is irradiated to both the power supply target device 2X and the power supply unnecessary device 2Y among the M power receiving devices 2[1] to 2[M]. The control device 11 determines whether to set the irradiation period TR as the resumption confirmation period TRY based on the power supply necessity confirmation information DH. Note that when the control device 11 does not set the irradiation period TR as the resumption confirmation period TRY, the control device 11 sets the irradiation period TR as the resumption confirmation unnecessary period TRX.

[0075] The control device 11 supplies irradiation control information DL[m] to the irradiation device 13 during the adjustment period Ta of the control period T. Then, during the adjustment period Ta, the irradiation device 13 adjusts the irradiation direction θB based on the irradiation control information DL[m] so that the light beam LB is emitted in a direction toward the power receiving device 2[m]. Furthermore, during the control period T, during the individual irradiation period Tb following the adjustment period Ta, the control device 11 supplies a power supply designation signal SB, the signal level of which is set to a high level, to the irradiation device 13. Then, during the individual irradiation period Tb, the irradiation device 13 irradiates the light beam LB toward the power receiving device 2[m] based on the power supply designation signal SB.

[0076] An example of the irradiation operation (hereinafter referred to as "irradiation operation example") shown in Figs. 11 to 14 will be described below.

[0077] In the example of the irradiation operation, it is assumed that the irradiation operation is composed of 17 irradiation periods TR, namely, irradiation periods TR-1 to TR-17. Also, in the example of the irradiation operation, it is assumed that the value M is "4" and the power supply system Sys includes four power receiving devices 2[1] to 2[4].

[0078] In the irradiation operation example, it is assumed that during the period from irradiation period TR-1 to irradiation period TR-5, charging of all four power receiving devices 2[1] to 2[4] is incomplete, and all four power receiving devices 2[1] to 2[4] are power supply target devices 2X. In the irradiation operation example, it is assumed that during irradiation period TR-6, charging of power receiving device 2[3] is completed, and among the four power receiving devices 2[1] to 2[4], power receiving device 2[3] changes from a power supply target device 2X to a power supply unnecessary device 2Y. In the irradiation operation example, it is assumed that during the period from irradiation period TR-7 to irradiation period TR-15, among the four power receiving devices 2[1] to 2[4], power receiving devices 2[1], 2[2], and 2[4] are power supply target devices 2X, and power receiving device 2[3] is a power supply unnecessary device 2Y. In the irradiation operation example, it is assumed that during irradiation period TR-15, the charging rate of the power receiving device 2[3] falls below the reference value, and the power receiving device 2[3] changes from a power-supply-unnecessary device 2Y to a power-supply target device 2X. In the irradiation operation example, it is assumed that during the period from irradiation period TR-16 to irradiation period TR-17, all of the four power receiving devices 2[1] to 2[4] are incompletely charged, and all of the four power receiving devices 2[1] to 2[4] are power-supply target devices 2X.

[0079] In addition, in the irradiation operation example, it is assumed that the power supply necessity confirmation interval AH is 12 times the time length of the control period Ts. Specifically, in the irradiation operation example, it is assumed that the first irradiation period TR-11 that starts 12 control periods Ts after the end of the control period Ts during which the power receiving device 2[3] changes from the power supply target device 2X to the power supply unnecessary device 2Y during the irradiation period TR-6 is set as the resumption confirmation period TRY, and the first irradiation period TR-16 that starts 12 control periods Ts after the end of the control period Ts during which the power receiving device 2[3] is irradiated with the light beam L during the irradiation period TR-11 is set as the resumption confirmation unnecessary period TRY. In addition, in the irradiation operation example, it is assumed that the irradiation periods TR among the irradiation periods TR-1 to TR-17 other than the irradiation period TR-11 and the irradiation period TR-16 are set as the resumption confirmation unnecessary period TRX.

[0080] In the example of the irradiation operation, as shown in FIG. 11 , the control device 11 sets the duration of the irradiation period TR-1 to be "AM times" the duration of the control period TS. At the start of the irradiation period TR-1, the number of power supply targets AM is "4," so the duration of the irradiation period TR-1 is set to "four times" the duration of the control period TS. Then, the control device 11 controls the irradiation device 13 so that the light beam LB is irradiated onto the power receiving device 2[m] during the mth control period TS included in the irradiation period TR-1. Note that, since charging of the four power receiving devices 2[1] to 2[4] has not yet been completed during the irradiation period TR-1, the light reception result signal SA is maintained at a low level during that period.

[0081] 11 and 12, the control device 11 controls the irradiation device 13 during irradiation periods TR-2 to TR-5 in the same manner as during irradiation period TR-1. During irradiation periods TR-2 to TR-5, as during irradiation period TR-1, charging of the four power receiving devices 2[1] to 2[4] is incomplete, and therefore the light reception result signal SA is maintained at a low level during these periods.

[0082] In the example of the irradiation operation, as shown in Fig. 12, the control device 11 controls the irradiation device 13 during the irradiation period TR-6 in the same manner as during the irradiation period TR-1. During the irradiation period TR-6, charging of the power receiving devices 2[1], 2[2], and 2[4] is incomplete, while charging of the power receiving device 2[3] is completed. Therefore, during the third control period Ts of the irradiation period TR-6, the light reception result signal SA becomes high level. Then, during the irradiation period TR-6, the control device 11 changes the number of power supply targets AM indicated by the power supply target number information DM from "4" to "3."

[0083] In the example of the irradiation operation, as shown in FIG. 12 , the control device 11 sets the duration of the irradiation period TR-7 to be "AM times" the duration of the control period TS. Because the number of power supply targets AM is "3" at the start of the irradiation period TR-7, the duration of the irradiation period TR-7 is set to "three times" the duration of the control period TS. The control device 11 then controls the irradiation device 13 so that the light beam LB is irradiated onto the power receiving device 2[1] during the first control period TS included in the irradiation period TR-7, the light beam LB is irradiated onto the power receiving device 2[2] during the second control period TS included in the irradiation period TR-7, and the light beam LB is irradiated onto the power receiving device 2[4] during the third control period TS included in the irradiation period TR-7. Note that, because charging of the power receiving devices 2[1], 2[2], and 2[4] is incomplete during the irradiation period TR-7, the light reception result signal SA is maintained at a low level during this period.

[0084] In the example of the irradiation operation, the control device 11 controls the irradiation device 13 during the irradiation periods TR-8 to TR-10 in the same manner as during the irradiation period TR-7, as shown in Figures 12 and 13. During the irradiation periods TR-8 to TR-10, as in the irradiation period TR-7, charging of the power receiving devices 2[1], 2[2], and 2[4] is incomplete, and therefore the light reception result signal SA is maintained at a low level during this period.

[0085] In the example of the irradiation operation, as shown in FIG. 13 , the control device 11 sets the irradiation period TR-11 to the resumption confirmation period TRY and sets the duration of the irradiation period TR-11 to be M times the duration of the control period Ts. In the example of the irradiation operation, since the value M is 4, the duration of the irradiation period TR-11 is set to four times the duration of the control period Ts. Then, the control device 11 controls the irradiation device 13 so that the light beam L is irradiated onto the power receiving device 2[m] during the mth control period Ts included in the irradiation period TR-11. Note that, as described above, during the irradiation period TR-11, charging of the power receiving devices 2[1], 2[2], and 2[4] is incomplete, while charging of the power receiving device 2[3] is completed. Therefore, during the first control period T, the second control period T, and the fourth control period T of the irradiation period TR-11, the light reception result signal SA remains at a low level, and during the third control period T of the irradiation period TR-11, the light reception result signal SA becomes a high level.

[0086] In the example of the irradiation operation, the control device 11 controls the irradiation device 13 during irradiation periods TR-12 to TR-15 in the same manner as during irradiation period TR-7, as shown in Figures 13 and 14. During irradiation periods TR-12 to TR-15, as with irradiation period TR-7, charging of power receiving devices 2[1], 2[2], and 2[4] is incomplete, and therefore the light reception result signal SA is maintained at a low level during these periods.

[0087] In the example of the irradiation operation, as shown in FIG. 14 , the control device 11 sets the irradiation period TR-16 to the resumption confirmation period TRY and sets the duration of the irradiation period TR-16 to be M times the duration of the control period Ts. In the example of the irradiation operation, since the value M is "4," the duration of the irradiation period TR-16 is set to be "four times" the duration of the control period Ts. Then, the control device 11 controls the irradiation device 13 so that the light beam L B is irradiated onto the power receiving device 2[m] during the mth control period Ts included in the irradiation period TR-16. Note that, as described above, charging of the four power receiving devices 2[1] to 2[4] is incomplete during the irradiation period TR-16. Therefore, the light reception result signal S A remains at a low level during the irradiation period TR-16. Then, during the irradiation period TR-16, the control device 11 changes the number A M of power receiving devices indicated by the power receiving device number information D M from "3" to "4."

[0088] In the example of the irradiation operation, as shown in FIG. 14 , the control device 11 sets the duration of the irradiation period TR-17 to be "AM times" the duration of the control period TS. At the start of the irradiation period TR-17, the number of power supply targets AM is "4," so the duration of the irradiation period TR-17 is set to "four times" the duration of the control period TS. Then, the control device 11 controls the irradiation device 13 so that the light beam LB is irradiated onto the power receiving device 2[m] during the mth control period TS included in the irradiation period TR-17. Note that, since charging of the four power receiving devices 2[1] to 2[4] is incomplete during the irradiation period TR-17, the light reception result signal SA is maintained at a low level during that period.

[0089] <A. 5. Irradiation Management Process> The irradiation management process will be described below with reference to Fig. 15 to Fig. 18. Here, the irradiation management process is a process in which the control device 11 controls the power supply device 1 when the power supply device 1 performs an irradiation operation.

[0090] 15, when the irradiation management process is started, the control device 11 acquires the power receiving device information DQ from the storage device 12 (S101). The control device 11 also acquires the power supply setting information DK from the storage device 12 (S103).

[0091] Next, the control device 11 determines whether the number of power supply targets AM indicated by the power supply target number information DM included in the power supply setting information DK satisfies "AM = M" (S105). If the result of the determination in step S105 is positive, that is, if the number of power supply targets AM is "M", the control device 11 sets the time length of the irradiation period TR to the time length of "M times" the control period TS (S107).

[0092] If the result of the determination in step S105 is negative, i.e., if the number of power supply targets A is less than "M," the control device 11 determines whether the irradiation period T is the resumption confirmation period T based on the power supply necessity confirmation interval A indicated by the power supply necessity confirmation information D included in the power supply setting information D (S109). If the result of the determination in step S109 is positive, i.e., if the irradiation period T is the resumption confirmation period T, the control device 11 proceeds to step S107 and sets the duration of the irradiation period T to "M times" the duration of the control period T. If the result of the determination in step S109 is negative, i.e., if the irradiation period T is the resumption confirmation unnecessary period T, the control device 11 sets the duration of the irradiation period T to "A times" the duration of the control period T (S111).

[0093] Thereafter, the control device 11 sets the variable m to "1" (S113), and the process proceeds to step S121.

[0094] 16 , the control device 11 determines whether the power supply necessity information DQ1[m] indicates "1" (S121). That is, in step S121, the control device 11 determines whether the power receiving device 2[m] has not been charged and whether the power receiving device 2[m] is a power supply target device 2X. If the result of the determination in step S121 is negative, that is, if the power receiving device 2[m] is a power supply-unnecessary device 2Y, the control device 11 proceeds to step S141.

[0095] If the result of the determination in step S121 is positive, i.e., if the power receiving device 2[m] is the power supply target device 2X, the control device 11 generates irradiation control information DL[m] based on the power supply target direction information DQ3[m] included in the power receiving device information DQ (S123). Next, the control device 11 controls the irradiation device 13 so that the light beam LB is irradiated onto the power receiving device 2[m] during the control period T S included in the irradiation period T R (S125).

[0096] Then, the control device 11 determines whether the light-reception result signal SA is at a low level during the control period TS in which the light beam LB was irradiated to the power receiving device 2[m] in step S125 (S127). If the result of the determination in step S127 is negative, i.e., if the light-reception result signal SA is at a high level, the control device 11 proceeds to step S161.

[0097] If the result of the determination in step S127 is positive, i.e., if the light reception result signal SA is at a low level, the control device 11 sets the power supply necessity information DQ1[m] to the value "0" indicating that power supply to the power receiving device 2[m] is not necessary (S129). The control device 11 also subtracts "1" from the number of power supply targets AM indicated by the power supply target number information DM (S131), and proceeds to step S161. That is, in steps S129 and S131, the control device 11 changes the power receiving device 2[m] from the power supply target device 2X to the power supply unnecessary device 2Y.

[0098] 17 , if the result of the determination in step S121 is negative, i.e., if the power receiving device 2[m] is a power-feed-unnecessary device 2Y, the control device 11 determines whether the irradiation period TR is a resumption confirmation period TRY based on the power feeding necessity confirmation information DH (S141). If the result of the determination in step S141 is negative, i.e., if the irradiation period TR is a resumption confirmation-unnecessary period TRX, the control device 11 proceeds to the process in step S161.

[0099] If the determination result in step S141 is positive, i.e., if the irradiation period TR is within the resumption confirmation period TRY, the control device 11 generates irradiation control information DL[m] based on the power supply target direction information DQ3[m] included in the power receiving device information DQ (S143). Next, the control device 11 controls the irradiation device 13 so that the light beam LB is irradiated onto the power receiving device 2[m] during the control period Ts included in the irradiation period TR (S145).

[0100] Then, the control device 11 determines whether the light-reception result signal SA is at a low level during the control period TS in which the light beam LB was irradiated to the power receiving device 2[m] in step S145 (S147). If the result of the determination in step S147 is negative, i.e., if the light-reception result signal SA is at a high level, the control device 11 proceeds to step S161.

[0101] If the result of the determination in step S147 is positive, i.e., if the light reception result signal SA is at a low level, the control device 11 sets the power supply necessity information DQ1[m] to a value "1" indicating that power supply to the power receiving device 2[m] is necessary (S149). The control device 11 also adds "1" to the number of power supply targets AM indicated by the power supply target number information DM (S151), and proceeds to step S161. That is, in steps S149 and S151, the control device 11 changes the power receiving device 2[m] from a power supply unnecessary device 2Y to a power supply target device 2X.

[0102] 18, the control device 11 adds "1" to the variable m (S161). Next, the control device 11 determines whether the variable m is "M" (S163). If the result of the determination in step S163 is negative, the control device 11 proceeds to step S121.

[0103] On the other hand, if the result of the determination in step S163 is positive, the control device 11 determines whether a predetermined charging end condition is satisfied (S165). Here, the predetermined charging end condition is a condition for ending the irradiation operation. For example, in the usage scenario of FIG. 2, the predetermined charging end condition may be the arrival of closing time of the supermarket.

[0104] If the result of the determination in step S165 is negative, the control device 11 advances the process to step S101. On the other hand, if the result of the determination in step S165 is positive, the control device 11 ends the irradiation management process.

[0105] <A. 6. Conclusion of the embodiment> As described above, the power supply device 1 according to the present embodiment includes the irradiation device 13 that irradiates the power receiving device 2[m] with a light beam LB used for transmitting power, and the light receiving device 14 that receives reflected light LH of the light beam LB reflected by the power receiving device 2[m]. The power receiving device 2[m] does not reflect the light beam LB when charging of the power receiving device 2[m] is not complete, and reflects the light beam LB in the incident direction of the light beam LB (i.e., the reflection direction θH) when charging of the power receiving device 2[m] is complete. The irradiation device 13 switches whether or not to irradiate the light beam LB to the power receiving device 2[m] based on the reception status of the reflected light LH by the light receiving device 14.

[0106] Therefore, the power supply device 1 according to this embodiment can determine whether charging of the power receiving device 2[m] is complete by using the light beam LB used to transmit power to the power receiving device 2[m]. That is, the power supply device 1 does not need to be configured to communicate with the power receiving device 2[m] to determine the charging status of the power receiving device 2[m]. Furthermore, the power supply device 1 does not need to be configured to irradiate the power receiving device 2[m] with a light beam separate from the light beam LB to determine the charging status of the power receiving device 2[m]. Therefore, according to this embodiment, the power supply device 1 can be simplified compared to an embodiment in which the power supply device 1 determines the charging status of the power receiving device 2[m] by communicating with the power receiving device 2[m] (hereinafter referred to as "Comparative Example 1") and an embodiment in which the power supply device 1 determines the charging status of the power receiving device 2[m] by irradiating the power receiving device 2[m] with a light beam separate from the light beam LB (hereinafter referred to as "Comparative Example 2")

[0107] Furthermore, the power receiving device 2[m] does not need to have a configuration for communicating with the power supply device 1 in order to notify the power supply device 1 of the charging status of the power receiving device 2[m]. Furthermore, the power receiving device 2[m] does not need to have a configuration for receiving a light ray separate from the light beam LB in order to notify the power supply device 1 of the charging status of the power receiving device 2[m]. Thus, according to this embodiment, the power receiving device 2[m] can be simplified compared to Comparative Examples 1 and 2.

[0108] Furthermore, the power supply device 1 of this embodiment switches whether or not to irradiate the beam light LB to the power receiving device 2[m] based on the reception status of the reflected light LH, and therefore, the power supply device 1 can achieve reduced power consumption compared to a configuration in which the irradiation of the beam light LB is not switched on or off.

[0109] Furthermore, in the power supply device 1 according to this embodiment, the irradiation device 13 is characterized in that, when the light receiving device 14 receives the reflected light LH, the irradiation of the light beam LB to the power receiving device 2[m] is limited.

[0110] Therefore, according to this embodiment, the power supply device 1 can save power compared to a mode in which the irradiation of the light beam LB is not limited.

[0111] In the present embodiment, as a specific example of limiting the irradiation of the light beam LB to the power receiving device 2[m], an example of lengthening the irradiation interval of the light beam LB to the power receiving device 2[m] has been described, but the present invention is not limited to this example. A specific example of limiting the irradiation of the light beam LB to the power receiving device 2[m] may be a case in which the irradiation of the light beam LB to the power receiving device 2[m] is stopped. In other words, in the power supply device 1 according to the present embodiment, the irradiation device 13 may be characterized in that it stops irradiating the light beam LB to the power receiving device 2[m] when the light receiving device 14 receives the reflected light LH.

[0112] Furthermore, in the power supply device 1 according to this embodiment, when the light receiving device 14 does not receive the reflected light LH, the irradiation device 13 irradiates the power receiving device 2[m] with a beam of light LB at an interval corresponding to the irradiation period TR (an example of a "first interval"), and when the light receiving device 14 receives the reflected light LH, the irradiation device 13 irradiates the power receiving device 2[m] with a beam of light LB at a power supply necessity confirmation interval AH (an example of a "second interval") longer than the irradiation period TR.

[0113] Therefore, according to this embodiment, when charging of the power receiving device 2[m] is completed and power supply to the power receiving device 2[m] is stopped, and then charging of the power receiving device 2[m] needs to be resumed again, the power supply device 1 can determine the timing for resuming power supply to the power receiving device 2[m].

[0114] Furthermore, in the power supply device 1 according to this embodiment, the power receiving device 2[m] is characterized in that it is provided with a retroreflective material 270 that reflects the beam light LB in a reflection direction θH opposite to the irradiation direction θB of the beam light LB.

[0115] Therefore, according to this embodiment, the power receiving device 2[m] can reflect the light beam LB emitted from the power supply device 1 toward the power supply device 1.

[0116] Furthermore, in the power supply device 1 according to this embodiment, the irradiation device 13 can irradiate a light beam LB to each of the M power receiving devices 2[1] to 2[M], and the light receiving device 14 receives, from the irradiation device 13, the light beam LB irradiated to the power receiving device 2[1] included in the M power receiving devices 2[1] to 2[M], the reflected light LH1 reflected by the power receiving device 2[1], and the light beam LH1 irradiated from the irradiation device 13 to the power receiving device 2[2] included in the M power receiving devices 2[1] to 2[M]. and reflected light LH2 reflected by the power receiving device 2[2] among the plurality of irradiation periods TR, the irradiation device 13 is capable of receiving reflected light LH1 and reflected light LH2 reflected by the power receiving device 2[2], and when the light receiving device 14 does not receive the reflected light LH1, the irradiation device 13 irradiates the power receiving device 2[1] with a light beam LB during one control period TS included in each of the plurality of irradiation periods TR, and when the light receiving device 14 does not receive the reflected light LH2, the irradiation device 13 irradiates the power receiving device 2[2] with a light beam LB during another control period TS included in each of the plurality of irradiation periods TR. Note that the power receiving device 2[1] is an example of a "first light receiving device," the power receiving device 2[2] is an example of a "second light receiving device," the reflected light LH1 is an example of a "first reflected light," the reflected light LH2 is an example of a "second reflected light," the one control period TS is an example of a "first control period," and the other control period TS is an example of a "second control period."

[0117] Therefore, according to this embodiment, the light beam LB can be irradiated to a plurality of power receiving devices 2 in a time-division manner.

[0118] Furthermore, in the power supply device 1 according to this embodiment, the time length of the irradiation period TR when the light receiving device 14 receives the reflected light LH1 is set to be shorter than the time length of the irradiation period TR when the light receiving device 14 does not receive the reflected light LH1, and the irradiation device 13 irradiates the light beam LB onto the power receiving device 2[1] in each of the multiple irradiation periods TR when the light receiving device 14 does not receive the reflected light LH1, and does not irradiate the light beam LB onto the power receiving device 2[1] in at least some of the multiple irradiation periods TR when the light receiving device 14 receives the reflected light LH1.

[0119] Therefore, according to this embodiment, when charging of the power receiving device 2[1] is completed, power supply to the power receiving device 2[1] is omitted, and efficient power supply to the power receiving devices 2 other than the power receiving device 2[1] among the M power receiving devices 2[1] to 2[M] is possible.

[0120] <B. Modifications> The above embodiments may be modified in various ways. Specific modification examples are given below. Two or more embodiments arbitrarily selected from the examples below may be combined as appropriate within a range that does not contradict each other. Note that, for elements in the modifications given below that have the same actions and functions as the embodiments, the reference numerals referenced in the above description will be used and detailed descriptions of each element will be omitted as appropriate.

[0121] <B.1. Modification 1> In the above-described embodiment, the power supply system Sys includes the power receiving device 2[m]. However, the present invention is not limited to this example. The power supply system Sys may include, for example, a power receiving device 2B[m] or a power receiving device 2C[m], which will be described below, instead of the power receiving device 2[m].

[0122] 19 and 20 are cross-sectional views showing an example of the configuration of the power receiving device 2B[m].

[0123] 19 and 20 , the power receiving device 2B[m] differs from the power receiving device 2[m] according to the embodiment in that it includes a reflecting device 27B[m] instead of the reflecting device 27[m]. The reflecting device 27B[m] differs from the reflecting device 27[m] in that it includes a support 273. Like the reflecting device 27[m], the reflecting device 27B[m] can be in either a reflective state in which the light beam LB is reflected toward the power supply device 1, or a reflection-suppressed state in which reflection of the light beam LB toward the power supply device 1 is suppressed.

[0124] FIG. 19 is a cross-sectional view showing an example of the configuration of the power receiving device 2B[m] when the reflecting device 27B[m] is in the reflection suppressing state.

[0125] 19, when the reflecting device 27B[m] is in the reflection suppression state, the reflecting device 27B[m] is disposed on the Y1 side of the power electronics device 26[m]. Note that in this modification, it is assumed that the irradiation range of the light beam LB from the power feeding device 1 to the power receiving device 2[m] is a wide area including not only the area where the power electronics device 26[m] is provided but also the area on the Y1 side of the power electronics device 26[m].

[0126] 19 , when the reflecting device 27B[m] is in the reflection-suppressing state, in a plan view of the power receiving device 2B[m], the retroreflector 270 is covered with the reflection-suppressing material 272. Therefore, when the reflecting device 27B[m] is in the reflection-suppressing state, the light beam LB is not reflected by the retroreflector 270, and the reflected light LH does not reach the power supply device 1.

[0127] FIG. 20 is a cross-sectional view showing an example of the configuration of the power receiving device 2B[m] when the reflecting device 27B[m] is in a reflecting state.

[0128] 20 , when the reflecting device 27B[m] is in the reflective state, the reflection suppressing material 272 is disposed on the Y1 side of the retroreflector 270. Therefore, when the reflecting device 27B[m] is in the reflective state, in a plan view of the power receiving device 2B[m], the retroreflector 270 is not covered by the reflection suppressing material 272. Therefore, when the reflecting device 27B[m] is in the reflective state, the light beam LB is reflected by the retroreflector 270, and reflected light LH reaches the power supply device 1.

[0129] In the first modification, the control device 21[m] included in the power receiving device 2B[m] controls the reflection device 27B[m] so that the reflection device 27B[m] is in the reflection state when the charge rate of the power storage device 25[m] is equal to or greater than a reference value, and the reflection device 27B[m] is in the reflection suppression state when the charge rate of the power storage device 25[m] is less than the reference value. However, the present invention is not limited to this aspect. In the first modification, the control device 21[m] included in the power receiving device 2B[m] may control the reflection device 27B[m] so that the reflection device 27B[m] is in the reflection suppression state when the charge rate of the power storage device 25[m] is equal to or greater than a reference value, and the reflection device 27B[m] is in the reflection state when the charge rate of the power storage device 25[m] is less than the reference value. That is, in this modified example, the control device 21[m] may control the reflection device 27B[m] so that the reflection device 27B[m] is in a reflective state when the charging of the storage device 25[m] is not yet completed.

[0130] 21 and 22 are cross-sectional views showing an example of the configuration of a power receiving device 2C[m].

[0131] 21 and 22 , the power receiving device 2C[m] differs from the power receiving device 2[m] according to the embodiment in that it includes a reflection device 27C[m] instead of the reflection device 27[m]. The reflection device 27C[m] differs from the reflection device 27[m] in that it does not include a reflection-suppressing material 272 and that it includes a liquid crystal panel 274. Like the reflection device 27[m], the reflection device 27C[m] can be in either a reflection state in which the light beam LB is reflected toward the power supply device 1, or a reflection-suppression state in which reflection of the light beam LB toward the power supply device 1 is suppressed.

[0132] The liquid crystal panel 274 is disposed so as to cover the retroreflector 270 when the power receiving device 2C[m] is viewed from above.

[0133] FIG. 21 is a cross-sectional view showing an example of the configuration of a power receiving device 2C[m] when a reflection device 27C[m] is in a reflection suppressing state.

[0134] 21 , when the reflecting device 27C[m] is in the reflection-suppressing state, the liquid crystal panel 274 is controlled so as not to transmit the light beam LB. Therefore, when the reflecting device 27C[m] is in the reflection-suppressing state, the light beam LB is not reflected by the reflecting device 27C[m], and the reflected light LH does not reach the power supply device 1.

[0135] FIG. 22 is a cross-sectional view showing an example of the configuration of the power receiving device 2C[m] when the reflecting device 27C[m] is in a reflecting state.

[0136] 22 , when the reflecting device 27C[m] is in the reflective state, the liquid crystal panel 274 is controlled to transmit the light beam LB and the reflected light LH. Therefore, when the reflecting device 27C[m] is in the reflective state, the light beam LB is reflected by the retroreflector 270, and the reflected light LH reaches the power supply device 1.

[0137] In the first modification, the control device 21[m] included in the power receiving device 2C[m] controls the reflection device 27C[m] so that the reflection device 27C[m] is in the reflection state when the charge rate of the power storage device 25[m] is equal to or greater than a reference value, and the reflection device 27C[m] is in the reflection suppression state when the charge rate of the power storage device 25[m] is less than the reference value. However, the present invention is not limited to this aspect. In the first modification, the control device 21[m] included in the power receiving device 2C[m] may control the reflection device 27C[m] so that the reflection device 27C[m] is in the reflection suppression state when the charge rate of the power storage device 25[m] is equal to or greater than a reference value, and the reflection device 27C[m] is in the reflection state when the charge rate of the power storage device 25[m] is less than the reference value. That is, in this modified example, the control device 21[m] may control the reflection device 27C[m] so that the reflection device 27C[m] is in a reflective state when the charging of the power storage device 25[m] is not yet completed.

[0138] As described above, the power supply device 1 of this modified example includes an irradiation device 13 that irradiates the power receiving device 2[m] with a beam of light LB used for transmitting power, and a light receiving device 14 that receives the reflected light LH of the beam of light LB reflected by the power receiving device 2[m], and is characterized in that the power receiving device 2[m] switches whether to reflect the beam of light LB depending on whether charging of the power receiving device 2[m] is complete, and the irradiation device 13 switches whether to irradiate the beam of light LB to the power receiving device 2[m] based on the reception status of the reflected light LH by the light receiving device 14.

[0139] Therefore, the power supply device 1 according to this modification can determine whether charging of the power receiving device 2[m] is complete by using the light beam LB used to transmit power to the power receiving device 2[m]. Therefore, according to this modification, the power supply device 1 and the power receiving device 2[m] can be simplified compared to Comparative Examples 1 and 2.

[0140] <B.2. Modification 2> In the above-described embodiment and Modification 1, the power supply device 1 may superimpose device identification information Im (an example of an "identification signal") on the light beam LB irradiated to the power receiving device 2[m]. Specifically, the power supply device 1 may superimpose the device identification information Im on the light beam LB by using a modulation method such as amplitude modulation (AM). In this case, the power supply device 1 can grasp the charging status of the power receiving device 2[m] by extracting the device identification information Im from the reflected light LH reflected by the power receiving device 2[m].

[0141] <B. 3. Modification 3> In the above-described embodiment and modifications 1 and 2, the power supply necessity confirmation interval AH is a fixed value. However, the present invention is not limited to this example. For example, the control device 11 may set the power supply necessity confirmation interval AH for each power receiving device 2[m] based on the non-power supply period information DQ2[m]. Specifically, the control device 11 may lengthen the power supply necessity confirmation interval AH as the elapsed time indicated by the non-power supply period information DQ2[m] increases. More specifically, the control device 11 may set the power supply necessity confirmation interval AH to an interval AH1 (another example of a "second interval") when the elapsed time indicated by the non-power supply period information DQ2[m] is a first time, and may set the power supply necessity confirmation interval AH to an interval AH2 (an example of a "third interval") when the elapsed time indicated by the non-power supply period information DQ2[m] is a second time.

[0142] That is, in the power supply device 1 according to this modified example, when the light receiving device 14 does not receive the reflected light LH, the irradiation device 13 irradiates the power receiving device 2[m] with a beam of light LB at an interval corresponding to the irradiation period TR (an example of a "first interval"), when a first time has elapsed since the light receiving device 14 started to receive the reflected light LH, the irradiation device 13 irradiates the power receiving device 2[m] with a beam of light LB at an interval AH1 (another example of a "second interval") longer than the irradiation period TR, and when a second time longer than the first time has elapsed since the light receiving device 14 started to receive the reflected light LH, the irradiation device 13 irradiates the power receiving device 2[m] with a beam of light LB at an interval AH2 (another example of a "third interval") longer than the interval AH1.

[0143] Therefore, according to this modified example, when charging of the power receiving device 2[m] is completed and power supply to the power receiving device 2[m] is stopped, and then charging of the power receiving device 2[m] needs to be resumed again, the power supply device 1 can determine the timing for resuming power supply to the power receiving device 2[m].

[0144] <B. 4. Modification 4> In the above-described embodiment and modifications 1 to 3, the power supply system Sys includes M power receiving devices 2[1] to 2[M]. However, the present invention is not limited to this example. The power supply system Sys may include a single power receiving device 2. In other words, the power supply system Sys may include one or more power receiving devices 2.

[0145] In a mode in which the power supply system Sys includes a single power receiving device 2, when the power receiving device 2 has not yet been charged and power supply to the power receiving device 2 is required, the power supply device 1 may periodically irradiate the power receiving device 2 with a light beam LB, for example, at every irradiation period TR, or may continuously irradiate the power receiving device 2 with a light beam LB until charging of the power receiving device 2 is complete. In a mode in which the power supply system Sys includes a single power receiving device 2, when charging of the power receiving device 2 is complete and power supply to the power receiving device 2 is no longer required, the power supply device 1 may periodically irradiate the power receiving device 2 with a light beam LB, for example, at every power supply necessity confirmation interval AH.

[0146] <C. Others> (1) In the above-described embodiment (including variations, the same applies below), storage device 12 and storage device 22[m] are exemplified by ROM and RAM, but may also be flexible disks, magneto-optical disks (e.g., compact disks, digital versatile disks, Blu-ray (registered trademark) disks), smart cards, flash memory devices (e.g., cards, sticks, key drives), CD-ROMs (Compact Disc-ROMs), registers, removable disks, hard disks, floppy (registered trademark) disks, magnetic strips, databases, servers, or other suitable storage media. The program may also be transmitted from a network via a telecommunications line. The program may also be transmitted from a communications network (NET) via a telecommunications line.

[0147] (2) In the above-described embodiments, the described information, signals, etc. may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0148] (3) In the above-described embodiment, input and output information may be stored in a specific location (for example, a memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be transmitted to another device.

[0149] (4) In the above-described embodiment, the determination may be made based on a value (0 or 1) represented using one bit, a Boolean value (true or false), or a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0150] (5) The order of the exemplary procedures, sequences, flowcharts, etc. illustrated in the above-described embodiments may be rearranged unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0151] (6) Each function illustrated in Figures 3 and 7 is realized by any combination of hardware and / or software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (e.g., wired, wireless, etc.) and these multiple devices. A functional block may be realized by combining software with the single device or the multiple devices.

[0152] (7) The programs exemplified in the above-described embodiments should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., regardless of whether they are called software, firmware, middleware, microcode, hardware description language, or by other names.

[0153] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0154] (8) In each of the foregoing embodiments, the terms "system" and "network" are used interchangeably.

[0155] (9) The information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or corresponding other information.

[0156] (10) In the above-described embodiments, the powered device 2[m], the powered device 2B[m], and the powered device 2C[m] may be mobile stations (MS). A mobile station may also be referred to by those skilled in the art as a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other appropriate term. In the present disclosure, the terms "mobile station," "user terminal," "user equipment (UE)," "terminal," etc. may be used interchangeably.

[0157] (11) In the above-described embodiments, the terms "connected," "coupled," or any variations thereof refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be a physical coupling or connection, a logical coupling or connection, or a combination thereof. For example, "connected" may be read as "access." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0158] (12) In the above embodiments, the phrase "based on" does not mean "based only on," unless otherwise specified. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0159] (13) As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching a table, database, or other data structure), and ascertaining something that is considered to be a "determining." Also, "determining" and "determining" may include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and so on. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0160] (14) In the above embodiments, when the terms "include," "including," and variations thereof are used, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, the term "or," as used in this disclosure, is not intended to be an exclusive or.

[0161] (15) In this disclosure, where articles are added by translation, such as a, an, and the in English, this disclosure may include the nouns following these articles being plural.

[0162] (16) In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

[0163] (17) Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Notification of predetermined information (e.g., notification that "X is true") is not limited to explicit notification, but may be implicit (e.g., not notifying the predetermined information).

[0164] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

[0165] 1...power supply device, 2...power receiving device, 11...control device, 12...storage device, 13...irradiation device, 14...light receiving device, 21 [m]...control device, 22 [m]...storage device, 23 [m]...display device, 24 [m]...communication device, 25 [m]...power storage device, 26 [m]...power conversion device, 27 [m]...reflection device, 270...retroreflective material, 271...support, 272...reflection suppression material, 2701...spherical portion, 2702...focal layer, 2703...reflective layer, 2704...base material, 2705...protective layer.

Claims

1. A power supply device comprising: an irradiation unit that irradiates a light beam used for transmitting power onto a power receiving device; and a light receiving unit that receives light of the light beam reflected by the power receiving device, wherein the power receiving device does not reflect the light beam when charging of the power receiving device is not complete, and reflects the light beam in the incident direction of the light beam when charging of the power receiving device is complete, and the irradiation unit switches whether or not to irradiate the light beam onto the power receiving device based on the reception status of the reflected light by the light receiving unit.

2. The power supply device according to claim 1, characterized in that the irradiating section limits irradiation of the beam light to the power receiving device when the light receiving section receives the reflected light.

3. The power supply device according to claim 1, characterized in that the irradiating unit irradiates the beam of light to the power receiving device at a first interval when the light receiving unit does not receive the reflected light, and irradiates the beam of light to the power receiving device at a second interval longer than the first interval when the light receiving unit receives the reflected light.

4. The power supply device of claim 1, wherein the irradiation unit irradiates the beam of light to the power receiving device at a first interval when the light receiving unit does not receive the reflected light, irradiates the beam of light to the power receiving device at a second interval longer than the first interval when a first time has elapsed since the light receiving unit began receiving the reflected light, and irradiates the beam of light to the power receiving device at a third interval longer than the second interval when a second time longer than the first time has elapsed since the light receiving unit began receiving the reflected light.

5. The power supply device according to claim 1, wherein the irradiating section superimposes an identification signal for identifying the power receiving device on the light beam.

6. The power supply device according to claim 1, characterized in that the power receiving device is provided with a retroreflective material that reflects the beam light in the direction of incidence of the beam light.

7. The power supply device according to claim 1, wherein the irradiating unit is capable of irradiating the light beam to each of a plurality of power receiving devices including the power receiving device; the light receiving unit is capable of receiving a first reflected light beam reflected by the first power receiving device among the light beams irradiated from the irradiating unit to a first power receiving device included in the plurality of power receiving devices, and a second reflected light beam reflected by the second power receiving device among the light beams irradiated from the irradiating unit to a second power receiving device included in the plurality of power receiving devices; and the irradiating unit irradiates the light beam to the first power receiving device during a first control period included in each of the plurality of irradiation periods when the light receiving unit does not receive the first reflected light, and irradiates the light beam to the second power receiving device during a second control period included in each of the plurality of irradiation periods when the light receiving unit does not receive the second reflected light.

8. The power supply device according to claim 7, characterized in that the length of the irradiation period when the light receiving unit receives the first reflected light is set shorter than the length of the irradiation period when the light receiving unit does not receive the first reflected light, and the irradiation unit irradiates the beam of light to the first power receiving device in each of a plurality of irradiation periods when the light receiving unit does not receive the first reflected light, and does not irradiate the beam of light to the first power receiving device in at least some of the plurality of irradiation periods when the light receiving unit receives the first reflected light.

9. A power receiving device comprising: a conversion unit that converts a beam of light emitted from a power supply device into electric power; and a reflection unit that reflects the beam of light in the direction of incidence of the beam of light when the level of charge of a storage unit that stores the electric power converted by the conversion unit is equal to or higher than a reference value, and does not reflect the beam of light when the level of charge of the storage unit is less than the reference value.

10. A power supply method comprising: irradiating a beam of light used for transmitting power from an irradiation unit to a power receiving device; receiving a reflected portion of the beam of light reflected by the power receiving device by a light receiving unit; switching whether or not to irradiate the beam of light from the irradiation unit to the power receiving device based on the reception status of the reflected light by the light receiving unit; and the power receiving device does not reflect the beam of light when charging of the power receiving device is not complete, and does not reflect the beam of light in the incident direction of the beam of light when charging of the power receiving device is complete.

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