Optical power supply system, power supply device, and power receiving device

Abstract

To provide an optical power supply system which simultaneously transmits electric power and information via power supply light, a power supply device and a power reception device.SOLUTION: An optical power supply system 1A comprises a power supply device 110 and a power reception device 310. The power supply device 110 includes a light-emitting section, which outputs power supply light 112, and a power supply control section 150. The power reception device 310 includes: a first light-receiving section 311a which converts the incident power supply light 112 into electric power; a second light-receiving section 311b which converts the incident power supply light 112 into an electric signal; and a demodulation section which acquires information by demodulating the electric signal converted by the second light-receiving section 311b. The power supply control section 150 switches the power supply light 112 between a first irradiation state where at least the first light-receiving section 311a is irradiated and a second irradiation state where both the first light-receiving section 311a and the second light-receiving section 311b are irradiated and an irradiated area of the second light-receiving section 311b is larger than that in the first irradiation state.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a photovoltaic power supply system, a power supply device, and a power receiving device.

Background Art

[0002] Recently, a photovoltaic power supply system that converts power into light (referred to as power supply light) for transmission and converts the power supply light into electrical energy for use as power has been studied. Patent Document 1 describes an optical communication device including an optical transmitter that transmits signal light modulated by an electrical signal and power supply light for supplying power, an optical fiber having a core that transmits the signal light, a first cladding formed around the core and having a refractive index smaller than that of the core for transmitting the power supply light, and a second cladding formed around the first cladding and having a refractive index smaller than that of the first cladding, and an optical receiver that operates with power obtained by converting the power supply light transmitted through the first cladding of the optical fiber and converts the signal light transmitted through the core of the optical fiber into the electrical signal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a photovoltaic power supply system, it is useful if power and information can be transmitted simultaneously by inserting information into the power supply light. The present disclosure aims to transmit power and information simultaneously via power supply light.

Means for Solving the Problems

[0005] The photovoltaic power supply system according to the present disclosure includes a power supply device and a power receiving device, The power supply device includes a light emitting unit that outputs power supply light, and a power supply control unit. The power receiving device includes a first light receiving unit that converts the incident power supply light into electric power, a second light receiving unit that converts the incident power supply light into an electric signal, and a demodulation unit that demodulates the electric signal converted by the second light receiving unit to acquire information. The power supply control unit switches the power supply light between a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which both the first light receiving unit and the second light receiving unit are irradiated and the irradiated area of the second light receiving unit is larger than that in the first irradiation state.

[0006] The power supply device according to the present disclosure includes a light emitting unit that outputs the power supply light toward a first light receiving unit and a second light receiving unit that convert the incident power supply light into electricity, and a power supply control unit. The power supply control unit switches the power supply light between a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which both the first light receiving unit and the second light receiving unit are irradiated and the irradiated area of the second light receiving unit is larger than that in the first irradiation state.

[0007] The power receiving device according to the present disclosure includes a first light receiving unit that converts the incident power supply light into electric power and a second light receiving unit that converts the incident power supply light into an electric signal. The power receiving device further includes a demodulation unit that demodulates the electric signal converted by the second light receiving unit to acquire information. and is provided with The first light receiving unit and the second light receiving unit are arranged side by side, and the power supply light can take a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which the power supply light irradiates both the first light receiving unit and the second light receiving unit and the irradiated area of the second light receiving unit is larger than that in the first irradiation state.

Advantages of the Invention

[0008] According to the present disclosure, power and information can be transmitted simultaneously via the power supply light.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0010] An embodiment of the present disclosure will be described below with reference to the drawings.

[0011] 〔First Embodiment〕 As shown in FIG. 1, the optical power supply system 1A of the present embodiment includes a power supply device (PSE: Power Sourcing Equipment) 110 and a power receiving device (PD: Powered Device) 310. The optical power supply system 1A transmits the power supply light 112 generated by the power supply device 110 to the power receiving device 310 through space. Such a space transmission optical power supply method is called PoA (Power over Air). Note that the power supply device in the present disclosure is a device that converts electric power into optical energy and supplies it, and the power receiving device is a device that receives the supply of optical energy and converts the optical energy into electric power. Also, in the present disclosure, power and information (data) are transmitted by the power supply light.

[0012] The power supply device 110 includes a power supply semiconductor laser 111 and a power supply control unit 150. The power supply device 110 is connected to a power source, and the power supply semiconductor laser 111 and the like are electrically driven. The power supply semiconductor laser 111 oscillates a laser using the power from the above power supply and outputs the power supply light 112. The power supply device 110 has a lens 115 such as a collimator lens, for example, and sends out the power supply light 112 emitted from the power supply semiconductor laser 111 into space via the lens 115. The lens 115 is configured to be movable in the direction of its central axis by driving of a lens driving unit 116 such as a motor. By moving the lens 115 by the lens driving unit 116, focusing adjustment of the power supply light 112 is performed. Note that there may be a plurality of lenses 115. In this case, a part of the lenses driven by the lens driving unit 116 may be used.

[0013] The power supply control unit 150 controls the laser oscillation of the power supply semiconductor laser 111 to control the output of the power supply light 112. Further, the power supply control unit 150 controls the operation of the lens driving unit 116 to perform focusing adjustment of the power supply light 112, thereby superimposing information on the power supply light 112. A specific information superimposing mode will be described later. Note that the information to be superimposed on the power supply light 112 is not particularly limited. For example, it may be a signal for notifying the power transmission state of the power supply device 110 to the power receiving device 310 (such as increasing the power supply amount from now on), a signal for controlling the devices (or external devices) of the power receiving device 310, or the like.

[0014] The power receiving device 310 includes a light receiving chamber 312 that receives the power supply light 112 from the power supply device 110. The light receiving chamber 312 has an opening 312b in the wall portion on the power supply device 110 side. The power supply light 112 from the power supply device 110 enters the light receiving chamber 312 through the opening 312b. Note that a lens such as a parallel flat plate having no power or a condenser lens may be disposed in the opening 312b.

[0015] Inside the light receiving chamber 312, as shown in FIGS. 2(a) and 2(b), two light receiving portions 311 (a first light receiving portion 311a and a second light receiving portion 311b), which are photoelectric conversion elements, are accommodated. The two light-receiving units 311 are arranged side by side on the wall portion of the light-receiving chamber 312 facing the opening 312b. However, the central axis (optical axis) of the power supply light 112 incident on the light-receiving chamber 312 through the opening 312b is located on the first light-receiving unit 311a. The two light-receiving units 311 convert the power supply light 112 incident on their respective light-receiving surfaces 311af and 311bf into electricity. In addition, the two light-receiving units 311 of the present embodiment are arranged side by side with their light-receiving surfaces 311af and 311bf in contact with each other.

[0016] The two light-receiving units 311 are irradiated with the power supply light 112 whose focus is adjusted by the power supply control unit 150. Specifically, the power supply control unit 150 adjusts the focus of the power supply light 112 while maintaining the laser output of the power supply semiconductor laser 111 substantially constant based on the information to be transmitted, thereby switching the power supply light 112 between the first irradiation state S1 and the second irradiation state S2. The first irradiation state S1 is a state in which the second light-receiving unit 311b is not irradiated and only the first light-receiving unit 311a is irradiated. The second irradiation state S2 is a state in which the irradiated area on the two light-receiving units 311 is larger than that in the first irradiation state S1, and both the first light-receiving unit 311a and the second light-receiving unit 311b are irradiated. Note that the output of the power supply semiconductor laser 111 (power supply light 112) being “substantially constant” means that it is substantially constant without any active output change due to control, and does not take into account the output change due to disturbances other than control.

[0017] The power supply light 112 in the first irradiation state S1 is converted into electric power by the first light-receiving unit 311a. On the other hand, for the power supply light 112 in the second irradiation state S2, the irradiated portion of the first light-receiving unit 311a is converted into electric power by the first light-receiving unit 311a, and the irradiated portion of the second light-receiving unit 311b is converted into an electrical signal by the second light-receiving unit 311b. As a result, at least the power corresponding to the first irradiation state S1 is stably output from the first light receiving unit 311a. On the other hand, as shown in FIG. 2(c), a signal 114 having a pulse waveform in which ON / OFF is switched between the second irradiation state S2 and the first irradiation state S1 is output from the second light receiving unit 311b. Therefore, by switching the power supply light 112 between the first irradiation state S1 and the second irradiation state S2, the modulated information can be superimposed on the power supply light 112.

[0018] Note that the first irradiation state S1 only needs to be a state in which the power supply light 112 is irradiated at least on the first light receiving unit 311a, and the second irradiation state S2 only needs to be a state in which both the first light receiving unit 311a and the second light receiving unit 311b are irradiated and the irradiated area of the second light receiving unit 311b is larger than that in the first irradiation state S1. Therefore, if the magnitude of the electrical output from the second light receiving unit 311b is different between the first irradiation state S1 and the second irradiation state S2, the power supply light 112 may be irradiated on the second light receiving unit 311b in the first irradiation state S1. In addition, in FIGS. 2(b) and 2(c), an example in which the signal 114 from the second light receiving unit 311b is binarized is shown, but higher-order digital modulation with more quantization or analog modulation may be performed. For example, as shown in FIGS. 3(a) and 3(b), the second irradiation state S2 may include a plurality of irradiation states (in the example of FIG. 3(a), two irradiation states S21 and S22) in which the irradiated areas of the second light receiving unit 311b are different from each other, and the signal 114 may be quantized. In addition, the method of switching the power supply light 112 between the first irradiation state S1 and the second irradiation state S2 is not limited to focusing adjustment of the power supply light 112. For example, as shown in FIG. 3(c), the power supply light 112 may be switched between the first irradiation state S1 and the second irradiation state S2 by moving the irradiation position of the power supply light 112. Even in this case, the signal 114 from the second light receiving unit 311b can be quantized or the like. Also in this case, the irradiated area and the focus state of the power supply light 112 on the first light receiving unit 311a and the second light receiving unit 311b may or may not change between the first irradiation state S1 and the second irradiation state S2 (in the example of FIG. 3(c), they do not change).

[0019] In addition, in the present embodiment, two light receiving units 311 (a first light receiving unit 311a and a second light receiving unit 311b) are arranged side by side with their light receiving surfaces 311af and 311bf in contact with each other. Thereby, even when the power supply light 112 is irradiated to both of the two light receiving units 311, light reception leakage between the two light receiving surfaces 311af and 311bf can be suppressed, and thus power supply and information extraction can be efficiently performed. However, as shown in FIG. 4(a), the two light receiving units 311 may be arranged side by side with a gap CL interposed between their light receiving surfaces 311af and 311bf. In this case, for example, it is possible to suppress the power supply light 112 irradiated to the end of the light receiving surface 311af of the first light receiving unit 311a in the first irradiation state S1 from being erroneously detected by the second light receiving unit 311b. In addition, a plurality of second light receiving units 311b for extracting information (electrical signal) from the power supply light 112 may be provided, for example, as shown in FIG. 4(b). In this case, all the second light receiving units 311b may be adjacent to the first light receiving unit 311a, or may include a second light receiving unit 311b that is adjacent only to another second light receiving unit 311b without being adjacent to the first light receiving unit 311a. Also, at each adjacent portion between the first light receiving unit 311a and the plurality of second light receiving units 311b, their light receiving surfaces may be in contact with each other, or a gap may be interposed therebetween. Further, the signals (information) obtained from each of the plurality of second light receiving units 311b may be different from each other, or may include the same ones.

[0020] In addition, as shown in FIG. 1, the power receiving device 310 includes a demodulation circuit 370 outside the light receiving chamber 312. The demodulation circuit 370 demodulates the signal 114 converted from the power supply light 112 by the second light receiving unit 311b and acquires the information pre-superimposed on the power supply light 112. The acquired information is output to a control unit or the like of the power receiving device 310 or output to an external device according to its content.

[0021] Each of the power supply semiconductor lasers 111 and the two light receiving parts 311 is a photoelectric conversion element including a laser medium with a laser wavelength of 500 nm or less. More specifically, the semiconductor material constituting the semiconductor region that exhibits the photoelectric conversion effect between light and electricity in the power supply semiconductor laser 111 and the two light receiving parts 311 is a semiconductor having a short laser wavelength of 500 nm or less. Since a semiconductor having a short laser wavelength has a large bandgap and high photoelectric conversion efficiency, the photoelectric conversion efficiency on the power generation side and the power reception side of the photovoltaic power supply is improved, and the photovoltaic power supply efficiency is improved. For this purpose, as the semiconductor material, for example, a semiconductor material of a laser medium having a laser wavelength (fundamental wave) of 200 to 500 nm such as diamond, gallium oxide, aluminum nitride, GaN, etc. may be used. In addition, as the semiconductor material, a semiconductor having a bandgap of 2.4 eV or more is applied. For example, a semiconductor material of a laser medium having a bandgap of 2.4 to 6.2 eV such as diamond, gallium oxide, aluminum nitride, GaN, etc. may be used. Note that the transmission efficiency of laser light is better for longer wavelengths and the photoelectric conversion efficiency is better for shorter wavelengths. Therefore, in the case of long-distance transmission, a semiconductor material of a laser medium having a laser wavelength (fundamental wave) greater than 500 nm may be used. Also, when giving priority to the photoelectric conversion efficiency, a semiconductor material of a laser medium having a laser wavelength (fundamental wave) less than 200 nm may be used. These semiconductor materials may be applied to at least one of the power supply semiconductor laser 111 and the two light receiving parts 311. The photoelectric conversion efficiency on the power supply side or the power reception side is improved, and the photovoltaic power supply efficiency is improved.

[0022] As described above, according to this embodiment, the power supply light 112 is switched between at least a first irradiation state S1 irradiated to the first light receiving unit 311a, and a second irradiation state S2 irradiated to both the first light receiving unit 311a and the second light receiving unit 311b, and having a larger irradiated area of the second light receiving unit 311b than the first irradiation state S1. The power supply light 112 irradiated to the first light receiving unit 311a through the first irradiation state S1 and the second irradiation state S2 is converted into electric power. On the other hand, the power supply light 112 irradiated to the second light receiving unit 311b is converted into electric signals having different output magnitudes in the first irradiation state S1 and the second irradiation state S2. This electric signal is demodulated by the demodulation circuit 370, and the information pre-superimposed on the power supply light 112 is extracted. That is, by switching the power supply light 112 between the first irradiation state S1 and the second irradiation state S2, it is possible to superimpose information on the power supply light 112 while supplying power by the power supply light 112. Therefore, it is possible to simultaneously transmit power and information via the power supply light 112.

[0023] Further, according to this embodiment, the power supply control unit 150 switches the power supply light 112 between the first irradiation state S1 and the second irradiation state S2 while keeping the output of the power supply semiconductor laser 111 substantially constant. Thereby, for example, compared with the case where information is superimposed by varying the laser output, it is possible to suppress the output variation of the power supply light 112 and improve the power supply efficiency.

[0024] 〔Second Embodiment〕 As shown in FIG. 5, the optical power supply system 1B of this embodiment includes a first data communication device 100 including a power supply device 110, an optical fiber cable 200, and a second data communication device 300 including a power receiving device 310. The power supply device 110 includes a power supply semiconductor laser 111 and a power supply control unit 150. The first data communication device 100 includes a receiving unit 130 in addition to the power supply device 110. The first data communication device 100 corresponds to a data terminal device (DTE (Data Terminal Equipment)), a repeater, etc. The receiving unit 130 includes a signal photodiode 131.

[0025] The optical fiber cable 200 includes an optical fiber 250 that forms a transmission path for signal light. One end of the optical fiber cable 200 is connectable to the first data communication device 100, and the other end is connectable to the second data communication device 300, and it transmits signal light.

[0026] The power receiving device 310 includes a light receiving chamber 312 that houses two light receiving parts 311 (the first light receiving part 311a and the second light receiving part 311b), and a demodulation circuit 370. The second data communication device 300 includes, in addition to the power receiving device 310, a transmission unit 320 and a data processing unit 340. The second data communication device 300 corresponds to, for example, a Power End Station. The transmission unit 320 includes a signal semiconductor laser 321 and a modulator 322. The data processing unit 340 is a unit that processes the received signal. Also, the second data communication device 300 is a node in the power supply network. Or the second data communication device 300 may be a node that communicates with other nodes.

[0027] The first data communication device 100 is connected to a power source, and a power supply semiconductor laser 111, a signal photodiode 131, etc. are electrically driven. Also, the first data communication device 100 is a node in the power supply network. Or the first data communication device 100 may be a node that communicates with other nodes. The power supply semiconductor laser 111 oscillates a laser by the power from the above power supply and outputs power supply light 112. At this time, similar to the first embodiment, the power supply control unit 150 adjusts the focus of the power supply light 112 while keeping the laser output of the power supply semiconductor laser 111 substantially constant based on the information to be transmitted, thereby switching the irradiation state of the power supply light 112 to the two light receiving units 311 between the first irradiation state S1 and the second irradiation state S2. The first irradiation state S1 is a state in which the power supply light 112 is irradiated at least to the first light receiving unit 311a. The second irradiation state S2 is a state in which both the first light receiving unit 311a and the second light receiving unit 311b are irradiated, and the irradiated area of the second light receiving unit 311b is larger than that of the first irradiation state S1. Thereby, information is superimposed on the power supply light 112. The power supply light 112 from the power supply device 110 is transmitted to the power receiving device 310 of the second data communication device 300 through space and enters the light receiving chamber 312.

[0028] The first light receiving unit 311a in the light receiving chamber 312 converts the irradiated power supply light 112 into electric power through the first irradiation state S1 and the second irradiation state S2. The obtained electric power is used as the driving power of the transmitting unit 320 and the data processing unit 340, and other driving power required in the second data communication device 300. Further, the second data communication device 300 may be capable of outputting the obtained electric power for an external device. On the other hand, the second light receiving unit 311b converts the irradiated power supply light 112 into electric signals having different output magnitudes in the first irradiation state S1 and the second irradiation state S2. The demodulation circuit 370 demodulates the electric signal converted by the second light receiving unit 311b and extracts the information previously superimposed on the power supply light 112. The acquired information is output to the data processing unit 340 or output to an external device according to its content.

[0029] The data processing unit 340 transmits the input data to a node, and on the other hand, receives data from the node and outputs it to the modulator 322 as transmission data 324. The modulator 322 of the transmitting unit 320 modulates the laser light 323 from the signal semiconductor laser 321 based on the transmission data 324 and outputs it as the signal light 325. The signal photodiode 131 of the receiving unit 130 demodulates the signal light 325 transmitted through the optical fiber cable 200 into an electrical signal and outputs it. The data by the electrical signal is transmitted to the node. The data from the node may be information that the power supply control unit 150 controls the power supply semiconductor laser 111 and superimposes on the power supply light 112.

[0030] The power supply light 112 from the first data communication device 100 is transmitted to the second data communication device 300 through the space. The signal light 325 from the second data communication device 300 is input to the optical fiber cable 200 and output to the first data communication device 100. Note that the signal light 325 may be transmitted through the space by the PoA method.

[0031] Each of the power supply semiconductor lasers 111 and the two light receiving units 311 includes the same semiconductor material as that in the first embodiment, which constitutes a semiconductor region having an optical-electric conversion effect. Thereby, high optical power supply efficiency is realized.

[0032] The optical power supply system 1B configured as described above can also obtain the same effects as those in the first embodiment. Also, various modification examples similar to those in the first embodiment can be applied to the optical power supply system 1B.

[0033] As described above, each embodiment of the present disclosure has been described. However, the content of the present disclosure is not limited to the above embodiments. Details shown in the embodiments can be appropriately changed without departing from the gist of the invention.

[0034] Hereinafter, an embodiment of the present disclosure will be shown. In one embodiment, (1) The optical power supply system includes a power supply device and a power receiving device, the power supply device has a light emitting unit that outputs power supply light and a power supply control unit, The power receiving device includes a first light receiving unit that converts the incident power supply light into electric power, a second light receiving unit that converts the incident power supply light into an electric signal, and a demodulation unit that demodulates the electric signal converted by the second light receiving unit to acquire information. The power supply control unit switches the power supply light between a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which both the first light receiving unit and the second light receiving unit are irradiated and the irradiated area of the second light receiving unit is larger than that in the first irradiation state.

[0035] (2) In the optical power supply system of (1) above, The second irradiation state includes a plurality of irradiation states in which the irradiated areas of the second light receiving unit are different from each other.

[0036] (3) In the optical power supply system of (1) or (2) above, Each of the light emitting unit, the first light receiving unit, and the second light receiving unit is a photoelectric conversion element including a laser medium having a laser wavelength of 500 nm or less.

[0037] (4) The power supply device includes a light emitting unit that outputs the power supply light toward a first light receiving unit and a second light receiving unit that convert the incident power supply light into electricity, and a power supply control unit. The power supply control unit switches the power supply light between a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which both the first light receiving unit and the second light receiving unit are irradiated and the irradiated area of the second light receiving unit is larger than that in the first irradiation state.

[0038] (5) In the power supply device of (4) above, The power supply control unit switches the power supply light between the first irradiation state and the second irradiation state by performing focus adjustment of the power supply light.

[0039] (6) In the power supply device of (4) above, The power supply control unit switches the power supply light between the first irradiation state and the second irradiation state by moving the irradiated position of the power supply light.

[0040] (7) In any of the power feeding devices (4) to (6) above, the power feeding control unit switches the power feeding light between the first irradiation state and the second irradiation state while keeping the output of the light emitting unit constant.

[0041] (8) The power receiving device is a first light receiving unit that converts the incident power feeding light into electric power, a second light receiving unit that converts the incident power feeding light into an electric signal, a demodulation unit that demodulates the electric signal converted by the second light receiving unit to acquire information, and includes the first light receiving unit and the second light receiving unit are arranged side by side, and the power feeding light can take a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which the power feeding light irradiates both the first light receiving unit and the second light receiving unit, and the irradiated area of the second light receiving unit is larger than that in the first irradiation state.

[0042] (9) In the power receiving device (8) above, the first light receiving unit and the second light receiving unit are arranged side by side with their light receiving surfaces in contact with each other.

[0043] (10) In the power receiving device (8) above, the first light receiving unit and the second light receiving unit are arranged side by side with a gap between their light receiving surfaces.

Explanation of Reference Numerals

[0044] 1A, 1B Optical power feeding system 110 Power feeding device 111 Power feeding semiconductor laser (light emitting unit) 112 Power feeding light 114 Signal 115 Lens 116 Lens driving unit 150 Power feeding control unit 310 Power receiving device 311 Light receiving unit 311a First light receiving unit 311af Light-receiving surface 311b Second light-receiving part 311bf Light-receiving surface 370 Demodulation circuit (demodulation part) CL Gap S1 First irradiation state S2 Second irradiation state

Claims

1. A power supply device and a power receiving device are provided, The power supply device includes a light emitting unit that outputs power supply light, and a power supply control unit, The power receiving device includes a first light receiving unit that converts the incident power supply light into electric power, a second light receiving unit that converts the incident power supply light into an electric signal, and a demodulation unit that demodulates the electric signal converted by the second light receiving unit to obtain information, The power supply control unit switches the power supply light between a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which both the first light receiving unit and the second light receiving unit are irradiated and the irradiated area of the second light receiving unit is larger than that in the first irradiation state, A light power supply system.

2. The second irradiation state includes a plurality of irradiation states in which the irradiated areas of the second light receiving unit are different from each other, The light power supply system according to Claim 1.

3. Each of the light emitting unit, the first light receiving unit, and the second light receiving unit is a photoelectric conversion element including a laser medium having a laser wavelength of 500 nm or less, The light power supply system according to Claim 1.

4. A light emitting unit that outputs the power supply light toward a first light receiving unit and a second light receiving unit that convert the incident power supply light into electricity, and a power supply control unit, The power supply control unit switches the power supply light between a first irradiation state in which at least the first light receiving unit is irradiated, and a second irradiation state in which both the first light receiving unit and the second light receiving unit are irradiated and the irradiated area of the second light receiving unit is larger than that in the first irradiation state, A power supply device.

5. The power supply control unit switches the power supply light between the first irradiation state and the second irradiation state by performing focus adjustment of the power supply light, The power supply device according to Claim 4.

6. The power supply control unit switches the power supply light between the first irradiation state and the second irradiation state by moving the irradiated position of the power supply light, The power supply device according to Claim 4.

7. The power supply control unit switches the power supply light between the first irradiation state and the second irradiation state while keeping the output of the light emitting unit constant, The power supply device according to Claim 4.

8. A first light receiving unit that converts the incident power supply light into electric power, A second light receiving unit that converts the incident power supply light into an electric signal, A demodulation unit that demodulates the electric signal converted by the second light receiving unit to obtain information, are provided, The first light receiving unit and the second light receiving unit are arranged in parallel, The power supply light can be in a first irradiation state in which the power supply light is irradiated at least on the first light receiving portion, and a second irradiation state in which the power supply light is irradiated on both the first light receiving portion and the second light receiving portion, and the irradiated area of the second light receiving portion is larger than that in the first irradiation state. Power receiving device. **Claim 9** The first light receiving portion and the second light receiving portion are arranged side by side with their light receiving surfaces in contact with each other. The power receiving device according to claim 8. **Claim 10** The first light receiving portion and the second light receiving portion are arranged side by side with a gap interposed between their light receiving surfaces. The power receiving device according to claim 8.

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