Power feeding device

Abstract

This power feeding device comprises M (M is an integer of 2 or more) laser light sources capable of controlling the directions of the respective optical axes, an acquisition unit, and a power feeding control unit. The acquisition unit acquires first position data indicating the position of a first device that converts the laser light emitted to the light-receiving surface into power by photoelectric conversion. The power feeding control unit supplies the power to the first device by controlling the optical axes of the M laser light sources so that mutually different positions on the light receiving surface of the first device are irradiated with the laser lights output from the M laser light sources.

Description

Power supply device

[0001] The present invention relates to a power supply device.

[0002] Various wireless power supply technologies that utilize laser light have been proposed (Patent Documents 1 to 5).

[0003] Japanese Patent Application Laid-Open No. 2023-061269 Japanese Patent Application Laid-Open No. 2017-163636 Special Publication No. 2018-525964 Special Publication No. 2021-509569 Japanese Patent Application Laid-Open No. 2022-166036

[0004] In conventional wireless power transfer technology that utilizes laser light, the amount of power that can be charged (hereinafter referred to as power transfer capacity) is determined according to the energy of the laser light used for power transfer. Therefore, if the power determined by the energy of the laser light used for power transfer is smaller than the power required by the device to be powered (hereinafter referred to as the power transfer target device), power cannot be transferred. To improve the power transfer capacity, it is necessary to increase the energy of the laser light used for power transfer. However, in order to increase the energy of the laser light, it is essential to consider ensuring safety. Furthermore, conventional wireless power transfer technology has also had the problem of waste when the power determined by the energy of the laser light used for power transfer is greater than the power required by the device to be powered.

[0005] A power supply device according to a preferred aspect of the present disclosure includes M (M is an integer of 2 or greater) laser light sources, each capable of controlling the orientation of its optical axis, an acquisition unit, and a power supply control unit. The acquisition unit acquires first position data indicating the position of a first device that converts laser light irradiated onto a light-receiving surface into electric power by photoelectric conversion. The power supply control unit supplies power to the first device by controlling the optical axes of the M laser light sources so that the laser light output from the M laser light sources is irradiated onto different positions on the light-receiving surface of the first device.

[0006] According to the power supply device of the present disclosure, waste due to interference of laser light is avoided compared to when the optical axes of multiple laser light beams intersect at a single point on the light receiving surface, thereby improving power supply efficiency.

[0007] 1 is a diagram illustrating an example of a power supply device 1 according to an embodiment of the present disclosure, and an example of a power supply target device 2 to which power is wirelessly supplied by the power supply device 1. FIG. 2 is a diagram illustrating an example of the configuration of the power supply device 1. FIG. 3 is a diagram illustrating an example of the configuration of a laser light source 10.

[0008] A. Embodiment FIG. 1 illustrates an example of a power supply device 1 according to an embodiment of the present disclosure, and an example of a power supply target device 2 to which power is supplied by the power supply device 1. The power supply device 1 is a device that wirelessly supplies power using laser light. The power supply device 1 is installed, for example, on the ceiling of a room in a house. The power supply device 1 wirelessly supplies power to a power supply target device 2 located in the room. The power supply device 1 may be supplied with operating power from a commercial AC power source. Alternatively, power generated by an indoor photovoltaic power generation device installed in the room may be supplied to the power supply device 1. As illustrated in FIG. 1 , the power supply device 1 includes laser light sources 10(1) to 10(M) that output laser light used for power supply. M is an integer of 2 or greater. In the example illustrated in FIG. 1 , M=6. However, M may be any integer from 2 to 5 or 7 or greater. The laser light sources 10(1) to 10(6) are arranged in a 3-row, 2-column matrix on the bottom surface of the power supply device 1. In this embodiment, the laser light sources 10(1) to 10(6) are arranged in a matrix of 3 rows and 2 columns on the bottom surface of the power supply device 1. However, the arrangement of the laser light sources 10(1) to 10(6) is arbitrary and is not limited to a matrix of 3 rows and 2 columns. When M is an integer between 2 and 5 or 7 or greater, the arrangement of the laser light sources 10(1) to 10(M) is also arbitrary.

[0009] The power supply target device 2 is a device to which power is supplied wirelessly by the power supply device 1. In this embodiment, the power supply target device 2 is a smartphone. However, the power supply target device 2 may also be a laptop computer, a tablet terminal, a toy, a hearing aid, or a dongle that supplies power to various devices. The various devices that are powered by a dongle may include a smartphone, a laptop computer, a tablet terminal, a toy, or a hearing aid. The power supply target device 2 has a light receiving surface that receives laser light output from the power supply device 1. In this embodiment, the light receiving surface is provided on a plane of the power supply target device 2. On the light receiving surface, light receiving elements 20(1) to 20(6) are arranged in a matrix of 3 rows and 2 columns. In this embodiment, the light receiving elements 20(1) to 20(6) are arranged in a matrix of 3 rows and 2 columns on the plane of the power supply target device 2, but the arrangement of the light receiving elements 20(1) to 20(6) is arbitrary and is not limited to a matrix of 3 rows and 2 columns. Furthermore, when M is any integer between 2 and 5 or 7 or greater, the arrangement of the light receiving elements 20(1) to 20(M) is also arbitrary. Each of the light receiving elements 20(1) to 20(M) converts the received laser light into electric power through photoelectric conversion. The electric power obtained through photoelectric conversion in each of the light receiving elements 20(1) to 20(M) is supplied to a battery built into the power supply target device 2, thereby charging the battery. The power supply target device 2 is an example of a first device in the present disclosure.

[0010] Fig. 2 is a diagram showing an example of the configuration of the power supply device 1. As shown in Fig. 2, the power supply device 1 includes a processing device 11 in addition to laser light sources 10(1) to 10(M). In addition to the power supply device 1, Fig. 2 also shows a personal computer (abbreviated as "PC" in Fig. 2) 3 for managing the operation of the power supply device 1.

[0011] The processing device 11 is, for example, a programmable logic controller (PLC). The processing device 11 operates in accordance with a pre-installed program, thereby functioning as a control center for the power supply device 1. The functions that the processing device 11 realizes in accordance with the pre-installed program will be explained later.

[0012] The laser light sources 10(1) to 10(M) all have the same configuration. Hereinafter, when there is no need to distinguish between the laser light sources 10(1) to 10(M), the laser light sources 10(1) to 10(M) will be referred to as laser light sources 10. FIG. 3 is a diagram showing an example of the configuration of the laser light source 10. As shown in FIG. 3, the laser light source 10 has a stepping motor 110, a rotary table 120, a gear box 130, and a laser oscillator 140.

[0013] The stepping motor 110 rotates the rotation axis X2 by a predetermined angle in accordance with a first pulse value (the number of peaks of the DC pulse voltage) applied from the processing device 11. A rotary table 120 is connected to the rotation axis X2 of the stepping motor 110. The stepping motor 110 rotates the rotary table 120 about the rotation axis X2 in the direction indicated by arrow Y3 or arrow Y4 in FIG. 3 by a predetermined angle in accordance with the first pulse value. The rotary table 120 is a flat, disk-shaped member. The rotation axis X2 of the stepping motor 110 is connected to the center of the plane of the rotary table 120.

[0014] The gear box 130 rotates the laser oscillator 140 around the rotation axis X1 in the direction indicated by the arrow Y1 or the direction indicated by the arrow Y2 in Fig. 3 under the control of the processing device 11. Although not shown in detail in Fig. 3, the gear box 130 includes a stepping motor that rotates the rotation axis (not shown) by a predetermined angle in accordance with the second pulse value applied from the processing device 11, and a worm gear that transmits the rotation of the stepping motor to the rotation axis X1.

[0015] The laser oscillator 140 outputs laser light used for wireless power supply in the direction indicated by the optical axis Z under the control of the processing device 11. In this embodiment, the wavelength of the laser light output from the laser oscillator 140 of each of the laser light source 10(1) to laser light source 10(M) is approximately the same. Furthermore, the power supply capacity of the laser light output from the laser oscillator 140 of each of the laser light source 10(1) to laser light source 10(M) is approximately the same, specifically, 1 W.

[0016] 3, the laser oscillator 140 is connected to the turntable 120 via the gearbox 130. In the laser light source 10, the direction of the optical axis Z can be adjusted by adjusting the amount of rotation of the stepping motor 110 and the amount of rotation of the stepping motor included in the gearbox 130. The above is the configuration of the laser light source 10.

[0017] Next, the functions realized by the processing device 11 in accordance with the pre-installed program will be described with reference to the aforementioned Fig. 2. The processing device 11 operates in accordance with the pre-installed program to function as the acquisition unit 11a and the power supply control unit 11b shown in Fig. 2. In other words, the acquisition unit 11a and the power supply control unit 11b shown in Fig. 2 are software modules realized by operating a computer such as a PLC in accordance with the program. The functions of the acquisition unit 11a and the power supply control unit 11b shown in Fig. 2 are as follows.

[0018] The acquiring unit 11a communicates with the PC 3 to acquire position data indicating the relative position of the power supply target device 2 with respect to the power supply device 1. A specific example of the relative position of the power supply target device 2 with respect to the power supply device 1 is the position of the center of gravity of the power supply target device 2 in a three-dimensional coordinate system with the center of gravity of the power supply device 1 as the origin. As a specific method for specifying the relative position of the power supply target device 2 with respect to the power supply device 1, for example, an existing technology such as the technology disclosed in Patent Document 3 may be appropriately adopted.

[0019] The power supply control unit 11b supplies power to the power supply target device 2 by controlling the optical axis Z of each of the laser light sources 10(1) to 10(M) so that the laser beams output from the laser light sources 10(1) to 10(M) are irradiated at mutually different positions on the light receiving surface of the power supply target device 2. More specifically, the power supply control unit 11b first calculates the relative positions of each of the light receiving elements 20(1) to 20(M) based on the position data acquired by the acquisition unit 11a. The power supply control unit 11b then calculates the rotation amount of the stepping motor 110 in the laser light source 10(m) and the rotation amount of the stepping motor included in the gearbox 130 based on the relative position of the light receiving element 20(m) so that the laser beam output from the laser light source 10(m) is irradiated at the light receiving element 20(m). Here, m is an integer greater than or equal to 1 and less than or equal to M. The reason why the laser light source 10(m) irradiates the light receiving element 20(m) with laser light is to simplify the control by the power supply control unit 11b.

[0020] Next, the power supply control unit 11b determines whether the laser light output from the laser light sources 10(1) to 10(M) includes multiple laser light beams that interfere with each other, based on the direction of the optical axis Z of each of the laser light sources 10(1) to 10(M). "Multiple laser light beams interfere with each other" means that the optical axes Z of the multiple laser light beams intersect with each other. The power supply control unit 11b outputs laser light beams that do not interfere with each other from the laser light sources 10(1) to 10(M). Furthermore, for multiple laser light beams that interfere with each other from the laser light sources 10(1) to 10(M), the power supply control unit 11b outputs the laser light beams only from the laser light source 10 with the smallest number.

[0021] For example, assume that it is determined that the laser beams output from the laser light source 10(1), the laser light source 10(2), and the laser light source 10(3) interfere with each other, while it is determined that the laser beams output from the laser light source 10(4), the laser light source 10(5), and the laser light source 10(6) do not interfere with each other. In this case, the power supply control unit 11b causes the laser light source 10(1), the laser light source 10(4), the laser light source 10(5), and the laser light source 10(6) to output laser beams, but does not cause the laser light source 10(2) and the laser light source 10(3) to output laser beams.

[0022] When the optical axes of multiple laser beams intersect at a single point on the light receiving surface, interference of the laser beams may result in waste. According to this embodiment, a decrease in power supply efficiency due to interference of the laser beams is avoided.

[0023] As described above, according to this embodiment, waste caused by interference of the laser light irradiated onto the light receiving surface of the power supply target device 2 is avoided. Therefore, power supply efficiency is improved compared to conventional wireless power supply techniques using laser light. Furthermore, according to this embodiment, wireless power supply to the power supply target device 2 is realized by combining the laser light output from the laser light sources 10(1) to 10(M). Therefore, even if the power supply capacity of one laser light source 10 is smaller than the power required by the power supply target device 2, there is no need to increase the power supply capacity of the laser light source 10, and no special measures are required to ensure safety.

[0024] B: Modifications The present disclosure is not limited to the above-described exemplary embodiments. Specific modifications are as follows. Two or more modifications arbitrarily selected from the following examples may be combined. B-1: Modification 1 When the sum of the power supply capacities of M laser light sources 10 is greater than the power required by the power supply target device 2, wireless power supply to the power supply target device 2 using all M laser light sources 10 results in waste. Therefore, when the sum of the power supply capacities of M laser light sources 10 is greater than the power required by the power supply target device 2, wireless power supply to the power supply target device 2 may be performed using N (N is an integer greater than or equal to 1 and less than M) laser light sources 10 out of the M laser light sources 10.

[0025] Specifically, the acquiring unit 11a may acquire first power data indicating the power required by the power supply target device 2 from the PC 3. In an aspect in which the acquiring unit 11a acquires the first power data, the power supply control unit 11b supplies power to the power supply target device 2 using N laser light sources 10 selected from the laser light sources 10(1) to 10(M) in accordance with the power indicated by the first power data.

[0026] B-2: Variation 2 If the sum of the power supply capacities of the M laser light sources 10 is greater than the power required by the power supply target device 2, the power supply device 1 may supply power to a second power supply target device different from the power supply target device 2 (a device that converts laser light irradiated onto its light receiving surface into electric power by photoelectric conversion, similar to the power supply target device 2), in parallel with the power supply to the power supply target device 2.

[0027] Specifically, the acquisition unit 11a acquires second location data indicating the location of the second power supply target device and second power data indicating the power required by the second power supply target device from the PC 3. If the sum of powers obtained by photoelectrically converting laser light emitted from M-N laser light sources 10, obtained by excluding N laser light sources 10 that wirelessly supply power to the power supply target device 2 from the M laser light sources 10, is equal to or greater than the power indicated by the second power data, the power supply control unit 11b selects L (L is an integer greater than or equal to 1 and less than or equal to M-N) laser light sources from among the M-N laser light sources 10 in accordance with the power indicated by the second power data. The power supply control unit 11b controls the optical axes of the L laser light sources so that the laser light output from the L laser light sources 10 is irradiated at mutually different positions on the light receiving surface of the second power supply target device, thereby supplying power to the second power supply target device in parallel with power supply to the power supply target device 2.

[0028] B-3: Modification 3 It is not essential that the power supply capacity of each of the M laser light sources 10 be approximately the same. For example, the power supply capacity of each of the laser light sources 10(1) to 10(3) may be 1 W, and the power supply capacity of each of the laser light sources 10(4) to 10(6) may be 0.5 W. In this case, by combining the laser beams output from the laser light sources 10(1) to 10(6), the power supply capacity of the power supply device 1 can be adjusted in 0.5 W increments within the range of 0.5 W to 4.5 W.

[0029] C: Other (1) 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 voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0030] (2) 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.

[0031] (3) In the above-described embodiment, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0032] (4) The order of the process 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.

[0033] (5) Each function illustrated in FIG. 2 is realized by any combination of hardware and / or software. Furthermore, the method for 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.

[0034] (6) 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 software is called software, firmware, middleware, microcode, hardware description language, or by other names.

[0035] 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.

[0036] (7) In the above embodiments, the terms "system" and "network" are used interchangeably.

[0037] (8) The information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or corresponding other information.

[0038] (9) In the above-described embodiments, the mobile terminal includes a mobile station (MS). A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term. In this disclosure, the terms "mobile station," "user terminal," "user equipment (UE)," "terminal," etc. may be used interchangeably.

[0039] (10) 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 physical, logical, 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.

[0040] (11) In the above embodiments, unless otherwise specified, the phrase "based on" does not mean "based only on." In other words, the phrase "based on" means both "based only on" and "based at least on."

[0041] (12) 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 the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judgment" or "decision." In other words, "judgment" and "decision" can include regarding some action as having been "judgment" or "decision." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0042] (13) In the above embodiments, when the words "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.

[0043] (14) In this disclosure, where articles are added by translation, such as a, an, and the in English, this disclosure may include the noun following these articles being plural.

[0044] (15) 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."

[0045] (16) The aspects / embodiments 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 being explicit, but may be implicit (e.g., not notifying the predetermined information).

[0046] D: Aspects Understood from the Above-described Embodiments or Modifications 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. The following aspects can be understood from at least one of the above-described embodiments or modifications.

[0047] A power supply device according to a first aspect of the present disclosure includes M (M is an integer equal to or greater than 2) laser light sources, each capable of controlling the orientation of its optical axis, an acquisition unit, and a power supply control unit. The acquisition unit acquires first position data indicating the position of a first device that converts laser light irradiated onto a light-receiving surface into electric power through photoelectric conversion. The power supply control unit supplies power to the first device by controlling the optical axes of the M laser light sources so that the laser light output from the M laser light sources is irradiated onto different positions on the light-receiving surface of the first device. The power supply device of the first aspect achieves an effect of improving power supply efficiency. When the optical axes of multiple laser light beams intersect at a single point on the light-receiving surface, waste may occur due to interference of the laser beams. According to the first aspect, a decrease in power supply efficiency caused by interference of the laser beams is avoided.

[0048] The power supply control unit in the power supply device according to a second aspect (an example of the first aspect) of the present disclosure determines whether the laser beams output from the M laser light sources include laser beams that interfere with each other based on the orientations of the optical axes of the M laser light sources, and controls the M laser light sources so that the laser beams that do not interfere with each other among the laser beams output from the M laser light sources are irradiated onto the light receiving surface. According to the second aspect, waste due to interference of the laser beams irradiated onto the light receiving surface is avoided. Therefore, power supply efficiency is improved compared to conventional wireless power supply technologies using laser beams.

[0049] An acquisition unit in a power supply device according to a third aspect (an example of the first aspect) of the present disclosure acquires first power data indicating the power required by the first device. Furthermore, a power supply control unit in the third aspect selects N (N is an integer greater than or equal to 1 and less than M) laser light sources from among the M laser light sources according to the power indicated by the first power data, and supplies power to the first device. According to the third aspect, when the sum of the power supply capacities of the M laser light sources 10 is greater than the power required by the first device, unnecessary laser light irradiation can be avoided.

[0050] In a power supply apparatus according to a fourth aspect (an example of the third aspect) of the present disclosure, an acquisition unit acquires second position data indicating the position of a second device that converts laser light irradiated on a light receiving surface into electric power by photoelectric conversion and second power data indicating the electric power required by the second device. When the sum of the electric powers obtained by photoelectrically converting the laser light irradiated from M-N laser light sources, obtained by subtracting the N laser light sources from the M laser light sources, is equal to or greater than the electric power indicated by the second power data, the power supply control unit according to the fourth aspect selects L (L is an integer greater than or equal to 1 and less than M-N) laser light sources from the M-N laser light sources in accordance with the electric power indicated by the second power data, and controls the optical axes of the L laser light sources so that the laser light output from the L laser light sources is irradiated at mutually different positions on the light receiving surface of the second device, thereby supplying electric power to the second device in parallel with the first device. According to the fourth aspect, wireless power supply to the first device and wireless power supply to the second device are performed in parallel, thereby improving power supply efficiency.

[0051] 1...power supply device, 2...power supply target device, 3...PC, 10(1) to 10(M)...laser light source, 20(1) to 20(M)...light receiving element, 110...stepping motor, 120...rotating table, 130...gearbox, 140...laser oscillator, 11...processing device, 11a...acquisition unit, 11b...power supply control unit.

Claims

1. A power supply device comprising: M (M is an integer of 2 or more) laser light sources, each of which can control the direction of its optical axis; an acquisition unit that acquires first position data indicating the position of a first device that converts laser light irradiated onto a light receiving surface into electric power through photoelectric conversion; and a power supply control unit that supplies power to the first device by controlling the optical axes of the M laser light sources so that the laser light output from the M laser light sources is irradiated onto different positions on the light receiving surface of the first device.

2. The power supply device described in claim 1, wherein the power supply control unit determines whether or not the laser light output from the M laser light sources includes laser light that interferes with each other based on the direction of the optical axis of each of the M laser light sources, and controls the M laser light sources so that laser light that does not interfere with each other among the laser light output from the M laser light sources is irradiated onto the light receiving surface.

3. The power supply device according to claim 1, wherein the acquisition unit acquires first power data indicating the power required by the first device, and the power supply control unit selects N (N is an integer greater than or equal to 1 and less than M) laser light sources from among the M laser light sources in accordance with the power indicated by the first power data, and supplies power to the first device.

4. The power supply device according to claim 3, wherein the acquisition unit acquires second position data indicating a position of a second device that converts laser light irradiated onto a light receiving surface into electric power by photoelectric conversion and second power data indicating electric power required by the second device, and the power supply control unit selects L (L is an integer greater than or equal to 1 and less than M-N) laser light sources from among the M-N laser light sources in accordance with the power indicated by the second power data when a sum of electric powers obtained by photoelectrically converting laser light irradiated from M-N laser light sources obtained by subtracting the N laser light sources from the M laser light sources is equal to or greater than the power indicated by the second power data, and supplies power to the second device in parallel with the power supply to the first device by controlling optical axes of the L laser light sources so that the laser light output from the L laser light sources is irradiated onto different positions on the light receiving surface of the second device.

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