Light receiving device and optical power supply system

Abstract

To improve performance while reducing the thickness of a light-receiving module or limiting its enlargement.SOLUTION: A light-receiving device that receives light beam L1 from a light source device comprises one or more light-receiving modules 400 connected in an array. An optical system 420 includes a pair of fly-eye lenses 422, 424 and an imaging lens 426. A first light guide structure 430 is an oblique prism or oblique cylinder and is positioned between the imaging lens 426 and a photoelectric conversion element 410.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an optical power supply system. [Background technology]

[0002] Wireless power supply has been put into practical use for electronic devices such as smartphones and tablet devices. Currently, practical wireless power supply uses electromagnetic waves in the frequency band of several hundred kHz, and known methods include electromagnetic induction and magnetic resonance. Although light is essentially a type of electromagnetic wave, in this specification, the term "electromagnetic wave" refers to electromagnetic waves with wavelengths longer than that of light.

[0003] Optical wireless power transfer, which uses light instead of electromagnetic waves, has been proposed. Light has the property of being more directional than electromagnetic waves, so by using a beam with a small divergence angle, it has the advantage of being able to transmit energy efficiently over long distances with little attenuation.

[0004] While the optical receiving module is rectangular, a typical optical beam is circular and has high intensity at the center. Therefore, when irradiating an optical beam that is smaller than the size of the optical receiving module, the optical beam is only irradiated to a part of the optical receiving module, resulting in the problem of concentrated heat generation.

[0005] In addition, in order to generate the necessary high output voltage, a photodetector module may be configured with multiple photodetectors (cells) arranged in an array and electrically connected in series. In such a configuration, maximizing the photoelectric conversion efficiency requires that the multiple photodetectors be irradiated with light of uniform intensity.

[0006] Increasing the size of the light beam makes it possible to illuminate the entire light-receiving module nearly uniformly, but leakage of the light beam outside the light-receiving module results in energy loss.Furthermore, if the leaked light becomes stray light and enters part of the light-receiving module, the uniform illumination will be impaired.

[0007] The present inventors have proposed a light-receiving module that uses a fly-eye lens system, which is capable of uniformly irradiating a light beam onto a plurality of light-receiving elements (cells) (Patent Document 1). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2020-036480 Summary of the Invention [Problem to be solved by the invention]

[0009] The light receiving module described in Patent Document 1 has difficulty in making it thinner because its size in the depth direction is restricted by the focal length of the imaging lens after the fly's eye lens.

[0010] The present disclosure has been made in light of such a situation, and one exemplary purpose of an embodiment thereof is to improve the performance of an optical receiver module while preventing the module from becoming thinner or larger. [Means for solving the problem]

[0011] One aspect of the present disclosure relates to a light-receiving device that receives a light beam from a light source device. The light-receiving device includes one light-receiving module or multiple light-receiving modules connected in an array. The light-receiving module includes a photoelectric conversion element and an optical system provided on the path of the light beam incident on the photoelectric conversion element. The optical system includes a pair of fly's-eye lenses and an imaging lens, and a first optical waveguide structure in the shape of an oblique prism or oblique cylinder provided on the propagation path of the light beam to the photoelectric conversion element.

[0012] Any combination of the above components or conversion of the present invention into a method, device, or other form is also valid as an embodiment of the present invention. Furthermore, the description in this section (Means for Solving the Problems) does not explain all essential features of the present invention, and therefore, subcombinations of the described features may also constitute the present invention. [Effects of the Invention]

[0013] According to an aspect of the present disclosure, it is possible to reduce the thickness of an optical receiver module, and also to improve the performance of an optical receiver module while preventing the module from becoming large. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating an optical power supply system according to an embodiment. [Figure 2] 1A and 1B are diagrams illustrating a light receiving module according to an embodiment. [Figure 3] 10A and 10B are cross-sectional views illustrating the guiding of light in the light-receiving module. [Figure 4] FIG. 10 is a cross-sectional view showing the configuration of a light receiving module according to a comparative technique. [Figure 5] FIG. 1 is a plan view of a light receiving device including a plurality of light receiving modules. [Figure 6] FIG. 6 is a cross-sectional view of the light receiving device of FIG. 5. [Figure 7] 10 is a cross-sectional view of a light-receiving device including a light-receiving module according to a first modification. FIG. [Figure 8] FIG. 10 is a cross-sectional view of a light-receiving device including a light-receiving module according to a second modification. [Figure 9] FIG. 11 is a cross-sectional view of a light-receiving device including a light-receiving module according to a third modification. [Figure 10] FIG. 10 is a cross-sectional view of a light-receiving device including a light-receiving module according to a fourth modification. [Figure 11] FIG. 11 is a cross-sectional view of a light-receiving device including a light-receiving module according to a fifth modification. [Figure 12] FIG. 13 is a cross-sectional view of a light-receiving device including a light-receiving module according to a sixth modification. [Figure 13] FIG. 13 is a cross-sectional view of a light-receiving device including a light-receiving module according to a seventh modification. DETAILED DESCRIPTION OF THE INVENTION

[0015] (Outline of the embodiment) A summary of some exemplary embodiments of the present disclosure is provided. This summary is intended to provide a simplified overview of some concepts of one or more embodiments in order to provide a basic understanding of the embodiments as a prelude to the more detailed description that follows. It is not intended to limit the scope of the invention or disclosure. This summary is not an exhaustive overview of all possible embodiments, and is not intended to identify key elements of all embodiments or to delineate the scope of some or all aspects. For convenience, the term "one embodiment" may refer to one embodiment (example or variant) or multiple embodiments (examples or variants) disclosed herein.

[0016] A light-receiving device according to one embodiment receives a light beam from a light source device. The light-receiving device includes one or more light-receiving modules connected in an array. The light-receiving module includes a photoelectric conversion element and an optical system provided on the path of the light beam incident on the photoelectric conversion element. The optical system includes a pair of fly's-eye lenses and an imaging lens, and a first optical waveguide structure having an oblique prism shape or an oblique circular cylinder shape provided on the propagation path of the light beam to the photoelectric conversion element.

[0017] With this configuration, in the light-receiving module where the light beam is incident, a uniform light beam can be irradiated over the entire surface of the photoelectric conversion element. Because a first optical waveguide structure with an oblique prismatic or oblique cylindrical shape is provided between the imaging lens and the photoelectric conversion element, the light emitted from the imaging lens reaches the photoelectric conversion element while being bent and reflected by the side surfaces of the oblique prismatic or oblique cylindrical optical waveguide structure. This allows the optical path length to be extended and the length in the depth direction to be shortened.

[0018] In one embodiment, the first optical waveguide structure may have a bent shape, which can reduce the width of the first optical waveguide structure of the light receiving module in the tilt direction.

[0019] In one embodiment, the optical system may further include a second optical waveguide structure having a rectangular or right circular cylindrical shape connected to the front stage of the first optical waveguide structure. A pair of fly's eye lenses may be provided in the second optical waveguide structure, thereby confining light that would otherwise be dissipated.

[0020] In one embodiment, the imaging lens may be provided in the second optical waveguide structure.

[0021] In one embodiment, the imaging lens may be provided in the first optical waveguide structure.

[0022] In one embodiment, the side surface of the first optical waveguide structure may be a total internal reflection surface.

[0023] In one embodiment, the side surface of the first optical waveguide structure sandwiched between two adjacent light-receiving modules may be a partially reflective surface in the range from the imaging lens to the photoelectric conversion element.

[0024] In one embodiment, the area between the rearmost fly-eye lens of the pair of fly-eye lenses and the imaging lens on the side surface of the first optical waveguide structure sandwiched between two adjacent light-receiving modules may be a partially reflective surface.

[0025] An optical power supply system according to an embodiment may include a light source device that emits a light beam and any of the light receiving devices described above.

[0026] In one embodiment, the photoelectric conversion element may include a plurality of cells connected in series, in which case the light beam can be uniformly irradiated onto the plurality of cells, thereby enabling the performance of the photoelectric conversion element to be fully exhibited.

[0027] In one embodiment, the shape of the lens elements constituting the fly's eye lens may be substantially the same as the shape of the light-receiving area of ​​the photoelectric conversion element, thereby enabling the beam to be irradiated onto the entire light-receiving area of ​​the photoelectric conversion element.

[0028] (Embodiment) In this embodiment, a new compact light-receiving module is constructed, and the entire light-receiving module is made thinner by arraying it to accommodate the required light-receiving element size, while maintaining the parallel placement of the fly-eye lens system and the light-receiving element module. This compact light-receiving module is made thinner by using a bending optical system with an even number of reflections at 45 degrees, and the reflecting mirror used maintains the various functions of the fly-eye lens system described in Patent Document 1. This arraying and bending optical system enables a light-receiving module equipped with a fly-eye lens system to be made thinner and maintain the functions of existing fly-eye lens systems, while requiring no or few additional devices to perform these functions, making it possible to simply configure the module.

[0029] The present invention will be described below based on preferred embodiments with reference to the drawings. The same or equivalent components, parts, and processes shown in each drawing will be given the same reference numerals, and redundant explanations will be omitted where appropriate. Furthermore, the embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention.

[0030] 1 is a diagram illustrating an optical power supply system 100 according to an embodiment. The optical power supply system 100 includes a light source device 200 and a light receiving device 300.

[0031] The light source device 200 irradiates an incident light beam L1 toward the light receiving device 300. The light receiving device 300 receives the incident light beam L1 from the light source device 200 and converts the light energy into electrical energy. The positional relationship between the light source device 200 and the light receiving device 300 is indefinite, and therefore the position and incident angle of the incident light beam L1 incident on the light receiving device 300 are not necessarily ideal.

[0032] The light receiving device 300 is configured by arranging one or more light receiving modules 400 in a continuous array.

[0033] 2 is a diagram showing a light receiving module 400 according to an embodiment. For ease of understanding, coordinate axes x, y, and z are set as shown in the figure.

[0034] The light-receiving module 400 includes a photoelectric conversion element 410 and an optical system 420. The photoelectric conversion element 410 is a solar cell that converts incident light energy into electrical energy. The light-receiving surface 412 of the photoelectric conversion element 410 is disposed perpendicular to the z-axis. The photoelectric conversion element 410 may consist of a single cell, but preferably includes multiple cells connected in series. The multiple cells may be arranged in a single row and connected in series, or in two rows and connected in series by folding back, or in three or more rows and connected in a meandering pattern; the connection is not limited thereto.

[0035] The optical system 420 is provided on the path of the incident light beam L1 that enters the photoelectric conversion element 410, and uniformizes the incident light beam L1 and irradiates the entire light receiving surface 412 of the photoelectric conversion element 410.

[0036] The optical system 420 includes a pair of fly-eye lenses 422 and 424, an imaging lens 426, a first optical waveguide structure 430, and a second optical waveguide structure 440. In this embodiment, the first fly-eye lens 422, the second fly-eye lens 424, and the imaging lens 426 are each arranged perpendicular to the z-axis and have a rectangular shape with sides parallel to the x-axis and y-axis.

[0037] Each of the fly-eye lenses 422, 424 is an array of a plurality of plano-convex lens elements LE arranged in a matrix, with the two fly-eye lenses 422, 424 arranged facing each other. Note that the configuration of the fly-eye lens is not limited to this, and it may be biconvex. Alternatively, a gradient index lens with flat surfaces on both sides may be used, with the lens function provided by controlling the refractive index distribution within the lens material. The focal length of each lens element LE is the same.

[0038] The fly-eye lens 422 on the light source device 200 side is referred to as a first fly-eye lens, and the fly-eye lens 424 on the photoelectric conversion element 410 side is referred to as a second fly-eye lens to distinguish them. The space between the first fly-eye lens 422 and the second fly-eye lens 424 may be filled with glass, and therefore the pair of fly-eye lenses 422, 424 may be integrally molded.

[0039] The first fly-eye lens 422 splits the light beam (light flux) from the light source device 200. The first fly-eye lens 422 functions as a plurality of secondary light sources. The second fly-eye lens 424 is disposed at the focal point of the first fly-eye lens 422.

[0040] The imaging lens 426 magnifies and forms an image of each lens element LE of the first fly-eye lens 422 onto the light-receiving surface 412 of the photoelectric conversion element 410. Therefore, the shape of the beam irradiated onto the light-receiving surface of the photoelectric conversion element 410 is determined by the shape of each lens element LE. Therefore, by making the shape of each lens element LE substantially identical to the shape of the photoelectric conversion element 410 and determining the magnification so that the image of the lens element LE is enlarged and projected onto the entire photoelectric conversion element 410, it is possible to irradiate the beam over the entire light-receiving area, thereby improving light utilization efficiency. In this embodiment, since the photoelectric conversion element 410 is rectangular, it is preferable to use a fly-eye lens having rectangular lens elements LE. If the light-receiving area of ​​the photoelectric conversion element 410 is hexagonal, it is preferable to use a fly-eye lens having hexagonal lens elements LE.

[0041] In the configuration of FIG. 2, the imaging lens 426 is designed with an NA (numerical aperture) of 0.25, and therefore the focal length f of the imaging lens 426 is twice the size h (length in the y-axis direction) of the photoelectric conversion element 410. Generally, optical parameters such as the NA and its reciprocal, the F-number, are defined for circular lenses and expressed using diameters. In contrast, in this specification, for ease of understanding, the numerical aperture of a rectangular lens is calculated by associating the length of one side with the diameter. It will be understood by those skilled in the art that the NA and the associated length of the first optical waveguide structure, etc., require precise design according to the lens shape, such as a rectangle.

[0042] The first optical waveguide structure 430 is provided between the imaging lens 426 and the photoelectric conversion element 410. The first optical waveguide structure 430 has an oblique quadrangular prism shape, and the inside of the side surface is formed by a reflecting surface. In this embodiment, the imaging lens 426 and the photoelectric conversion element 410 are located on the parallel top and bottom surfaces of the oblique quadrangular prism-shaped first optical waveguide structure 430. Two side surfaces 431 and 432 of the first optical waveguide structure 430 are inclined at an angle of 45° around the x-axis, and the remaining two side surfaces 433 and 434 are perpendicular to the x-axis and parallel to the yz plane.

[0043] The second optical waveguide structure 440 is connected to the front stage of the first optical waveguide structure 430. The second optical waveguide structure 440 has a rectangular prism shape, and the inside of the side surface is formed as a reflective surface.

[0044] The above is the configuration of the light receiving module 400.

[0045] 3 is a cross-sectional view illustrating the guiding of light in the light-receiving module 400. The light beam L1 is locally irradiated onto some lens elements LE of the first fly-eye lens 422.

[0046] Consider a light beam incident on one lens element LE. Light that passes through a certain lens element LE of the first fly-eye lens 422 enters the corresponding lens element LE of the second fly-eye lens 424 and is magnified by the imaging lens 426. The reflecting surfaces 431 and 432 of the first optical waveguide structure 430 form a bending optical system with an even number of reflections at 45°.

[0047] The chief ray is reflected twice in the first optical waveguide structure 430, by the first reflecting surface 431 and the second reflecting surface 432, and is guided to the photoelectric conversion element 410. The first optical waveguide structure 430 can guide the light beam L1 to the photoelectric conversion element 410 even when the light beam L1 is obliquely incident on the light receiving device 300. In other words, the allowable range of the incident angle of the light beam L1 with respect to the first fly-eye lens 422 can be significantly expanded.

[0048] The above is the configuration of the light receiving module 400. The advantages obtained by the light receiving module 400 will now be described.

[0049] According to this light receiving module 400, the light beam L1 incident on a portion of the first fly-eye lens 422 can be enlarged and projected onto the entire photoelectric conversion element 410. This eliminates the need to increase the beam size of the light beam L1, thereby reducing the amount of light that spills out of the first fly-eye lens 422. Furthermore, local overheating of the photoelectric conversion element 410 can be suppressed.

[0050] Furthermore, it is sufficient that the light beam L1 hits anywhere on the first fly-eye lens 422. This means that there are improvements in tolerance to variations in the distance between the light source device 200 and the light receiving device 300, tolerance to deviations in the incident position of the light beam L1, tolerance to changes in the incident direction (although there are angular restrictions), and tolerance to variations in the shape and size of the incident beam. In addition, power supply using multiple incident beams L1 can be easily accommodated.

[0051] Furthermore, when the photoelectric conversion element 410 is configured as a series-connected circuit of a plurality of cells, all the cells are irradiated with light, so that a decrease in photoelectric conversion efficiency can be suppressed.

[0052] The light receiving module 400 of this embodiment further has the following advantages: These advantages become clear when compared with the comparative techniques.

[0053] 4 is a cross-sectional view showing the configuration of a light receiving module 400R according to a comparative example. In the comparative example, a first optical waveguide structure 430R is formed of a right square prism. The other configurations are the same as those of the embodiment.

[0054] The propagation distance of the chief ray of the light beam in the first optical waveguide structure 430R is equal to the focal length f of the imaging lens 426, and when NA=0.25, is twice the size of the photoelectric conversion element 410. Therefore, the depth D of the first optical waveguide structure 430R is twice the size h of the photoelectric conversion element 410.

[0055] Returning to Fig. 3, in this embodiment, the reflecting surfaces 431 and 432 of the first optical waveguide structure 430 form a bending optical system with two 45° reflections, so the propagation distance of light is twice the depth D (height of the oblique rectangular prism) of the first optical waveguide structure 430. The propagation distance of the chief ray of the light beam is equal to the focal length f of the imaging lens 426, so the depth D is reduced to 1 / 2 of the focal length f.

[0056] When NA=0.25, the focal length f is twice the size h of the photoelectric conversion element 410, and therefore the depth D (height of the oblique rectangular prism) of the first optical waveguide structure 430 is equal to the size h of the photoelectric conversion element 410. In other words, compared to the comparative technology, the depth D of the first optical waveguide structure 430 can be reduced by half. This advantage is particularly noticeable when the photoelectric conversion element 410 is enlarged to supply high power.

[0057] The light receiving device 300 can be configured by arranging the above-described light receiving modules 400 in an array.

[0058] 5 is a plan view of a light receiving device 300 including a plurality of light receiving modules 400. In this example, nine light receiving modules 400_1 to 400_9 are arranged in a 3 × 3 matrix. The light receiving device 300 receives one or more light beams L1.

[0059] The photoelectric conversion element 410 of each light-receiving module 400 is configured as a series-connected circuit of an appropriate number of cells so that the required output voltage Vout can be extracted. The outputs of the photoelectric conversion elements 410 of the multiple light-receiving modules 400_1 to 400_9 are electrically connected in parallel. This allows each light-receiving module 400 that receives a light beam to achieve high photoelectric conversion efficiency, and connecting multiple light-receiving modules 400 in parallel enables high power output.

[0060] In this example, the light receiving device 300 is irradiated with two light beams L1a and L1b, and the light receiving modules 400_1, 400_2, 400_4, and 400_5 that receive the light beam L1a and the light receiving modules 400_6 and 400_9 that receive the light beam L1b generate power.

[0061] 6 is a cross-sectional view of the light-receiving device 300 of FIG. 5. The first reflecting surface 431 of a given light-receiving module 400_1 and the second reflecting surface 432 of the adjacent light-receiving module 400_2 can be made of a common member. That is, reflecting surfaces are formed on both sides of the partition wall 435 of the adjacent first optical waveguide structure 430. This allows the number of members of the light-receiving device 300 to be reduced, resulting in lower costs and weight. Alternatively, the partition wall 435 may be made of a transparent member such as glass, and a reflecting surface may be formed on one side thereof. The reflecting surface may be formed of a metal or a dielectric multilayer film.

[0062] Next, a modified example of the light receiving module 400 will be described.

[0063] (Variation 1) Lenses with a large NA are difficult to manufacture and to control their characteristics, so there are cases where it is desirable to use an imaging lens with a smaller NA, i.e., an imaging lens with a longer focal length.

[0064] 7 is a cross-sectional view of a light receiving device 300A including a light receiving module 400A according to Modification 1. In this modification, the imaging lens 426 is designed with an NA (numerical aperture) of 0.125, and therefore the focal length f of the imaging lens 426 is four times the size h (length in the y-axis direction) of the photoelectric conversion element 410. The chief ray is reflected four times by the first reflecting surface 431 and the second reflecting surface 432 within the first optical waveguide structure 430A and is guided to the photoelectric conversion element 410.

[0065] In this case, in the comparative technique, the depth D needs to be four times the size h of the photoelectric conversion element 410, but in the first modification, the depth D can be half that, 2×h.

[0066] (Variation 2) 8 is a cross-sectional view of a light receiving device 300B including a light receiving module 400B according to Modification 2. Similar to Modification 1, Modification 2 is designed with an NA (numerical aperture) of 0.125, and the focal length f of the imaging lens 426 is four times the size h (length in the y-axis direction) of the photoelectric conversion element 410. The first optical waveguide structure 430B has a bent oblique quadrangular prism shape, and has a shape formed by joining two oblique quadrangular prisms with a height h in opposite directions.

[0067] The advantages of Modification 2 become clear when compared with Modification 1. The light receiving module 400A according to Modification 1 has a size H in the y direction of 3×h. In contrast, the light receiving module 400B according to Modification 2 has a size H in the y direction of 2×h, which allows for a smaller size.

[0068] (Variation 3) In a light-receiving device including the light-receiving module described in the embodiment or Modifications 1 and 2, heat is generated only in the light-receiving module into which a light beam is incident. Therefore, when viewed as a whole, the light-receiving device 300 can be considered to generate localized heat. If a single light-receiving module were to receive the power required for the entire light-receiving device 300, the heat generated by the photoelectric conversion element 410 of that light-receiving module would be very large, making the heat dissipation design of the photoelectric conversion element 410 very difficult. Modification 3 can solve this problem.

[0069] 9 is a cross-sectional view of a light-receiving device 300C including a light-receiving module 400C according to Modification 3. In Modification 3, a first optical waveguide structure 430C has a second reflecting surface 432 formed on a partition wall 435 that is a partially reflecting surface, and a portion of light guided through the first optical waveguide structure 430C is transmitted to the first optical waveguide structure 430C of the adjacent light-receiving module 400C.

[0070] The first reflecting surface 431 of the light receiving module 400C_1 and the second reflecting surface 432 of the light receiving module 400C_3 have a high reflectance close to 100% so as to prevent light from leaking to the outside.

[0071] In the light-receiving module 400C according to the third modification, a light beam incident on one light-receiving module 400C_1 is dispersed to the light-receiving modules 400C_2 and 400C_3 adjacent in the y direction. This prevents heat from concentrating on one photoelectric conversion element 410. This facilitates the heat dissipation design of the photoelectric conversion element 410.

[0072] The reflectance (transmittance) of the partition wall 435 may be designed taking into consideration the number of light-receiving modules 400C arranged in the y direction, the expected size of the light beam, etc. The reflectance may be different for each light-receiving module 400C.

[0073] (Variation 4) 10 is a cross-sectional view of a light receiving device 300D including a light receiving module 400D according to Modification 4. In this modification, an imaging lens 426 is provided in a first optical waveguide structure 430D having an oblique quadrangular prism shape. Of the reflective surface of the first optical waveguide structure 430D, a range 430Da upstream of the imaging lens 426 is formed by a partial reflector, and a range 430Db downstream of the imaging lens 426 is formed by a total reflective surface.

[0074] In the fourth modification, the dispersion of the light beam described in the third modification is performed before the imaging lens 426 .

[0075] In the third modification, the dispersion of the light beam is performed after the imaging lens 426. Therefore, the propagation distance of the light transmitted through the adjacent first optical waveguide structure 430 before reaching the photoelectric conversion element 410 becomes longer than the focal length of the imaging lens 426. Therefore, strictly speaking, the entire photoelectric conversion element 410 is not uniformly illuminated.

[0076] In contrast to this, in the fourth modification, the propagation distance from the imaging lens 426 to the photoelectric conversion element 410 is equal to the focal length f of the imaging lens 426, so that the entire photoelectric conversion element 410 can be uniformly irradiated with light.

[0077] (Variation 5) 11 is a cross-sectional view of a light receiving device 300E including a light receiving module 400E according to Modification 5. As in Modification 4, the imaging lens 426 is provided in a first optical waveguide structure 430E having an oblique quadrangular prism shape, and of the reflective surface of the first optical waveguide structure 430E, a range 430Ea upstream of the imaging lens 426 is configured as a partial reflector, while a range 430Eb downstream of the imaging lens 426 is configured as a total reflective surface. In Modification 5, the ranges 430Ea and 430Eb are oriented in the opposite direction to those in Modification 4. This allows the size of the light receiving device 300E in the y direction to be reduced.

[0078] (Variation 6) 12 is a cross-sectional view of a light receiving device 300F including a light receiving module 400F according to Modification 6. As in Modification 5, of the reflective surface of the first optical waveguide structure 430F, a range 430Fa upstream of the imaging lens 426 is configured as a partial reflector, and a range 430Fb downstream of the imaging lens 426 is configured as a total reflective surface. Modification 6 differs from Modification 5 in that the range 430Fa is bent.

[0079] The advantages of the structure of FIG. 12 (Variation 6) become clear when compared with the structure of FIG. 11 (Variation 5). In FIG. 11, the first optical waveguide structure 430Ea allows light to pass only in one direction (downward on the paper) into the modules. When light enters the light-receiving module 400E_3, the light is confined within the light-receiving module 400E_3, and the light-receiving modules 400E_1 and 400E_2 do not function. In contrast, in the structure of FIG. 12, the first optical waveguide structure 430Fa allows light to be guided in both directions between the modules. When light enters the light-receiving module 400F_3, the light can be guided to the light-receiving modules 400E_2 and 400E_1, allowing all the light-receiving modules 400 to be used effectively.

[0080] (Variation 7) 13 is a cross-sectional view of a light receiving device 300G including a light receiving module 400G according to Modification 7. As in Modification 6, of the reflective surface of the first optical waveguide structure 430G, a range 430Ga upstream of the imaging lens 426 is configured with a partial reflector, and a range 430Gb downstream of the imaging lens 426 is configured with a total reflective surface, and further, range 430Ga is bent. In Modification 7, the interior of range 430Ga is divided into spaces corresponding to the lens elements of the second fly's eye lens 424, and the walls dividing the spaces are configured with partial reflectors. In Modification 7, the size of range 430Ga can be made smaller than range 430Fa in FIG. 12.

[0081] Here, the interior of range 430Ga is divided into units of lens elements of second fly-eye lens 424, but this is not limitative and range 430Ga may be divided into units of multiple lens elements. In this case, the size of range 430Ga will be larger than in FIG. 13, but can be smaller than in FIG. 12.

[0082] (Variation 8) In the embodiment, the first optical waveguide structure 430 has been described as an oblique quadrangular prism, but the present disclosure is not limited thereto. When one light-receiving module 400 is used alone, any shape of an oblique polygonal prism or an oblique circular cylinder may be adopted. Alternatively, the first optical waveguide structure 430 may be an oblique hexagonal prism, and multiple light-receiving modules 400 may be arranged in a honeycomb pattern. Alternatively, the first optical waveguide structure 430 may be an oblique circular cylinder, and multiple light-receiving modules 400 may be closely arranged.

[0083] The present disclosure has been described using specific terms based on the embodiments, but the embodiments merely illustrate the principles and applications of the present disclosure, and many modifications and changes in arrangement are permitted to the embodiments as long as they do not deviate from the concept of the present invention defined in the claims. [Explanation of symbols]

[0084] 100 Optical power supply system 200 Light source device 300 Photodetector 400 Optical Receiver Module 410 Photoelectric conversion element 412 Photosensitive surface 420 Optical system 422 1st fly-eye lens 424 2nd fly-eye lens LE Lens Element 426 Imaging Lens 430 1st optical waveguide structure 440 Second optical waveguide structure L1 light beam

Claims

1. A light receiving device that receives a light beam from a light source device, The optical receiver includes one or a plurality of optical receiver modules connected in an array, The light receiving module includes: a photoelectric conversion element; an optical system provided on a path of the light beam incident on the photoelectric conversion element; Equipped with The optical system comprises: a pair of a fly-eye lens and an imaging lens; a first optical waveguide structure having an oblique prism shape or an oblique circular cylinder shape provided on a propagation path of the light beam to the photoelectric conversion element; A light receiving device comprising:

2. The light receiving device according to claim 1 , wherein the first optical waveguide structure has a bent shape.

3. the optical system further includes a second optical waveguide structure having a rectangular prism shape or a right circular prism shape connected to a front stage of the first optical waveguide structure, 3. The light receiving device according to claim 1, wherein the pair of fly-eye lenses are provided in the second optical waveguide structure.

4. 4. The light receiving device according to claim 3, wherein the imaging lens is provided in the second optical waveguide structure.

5. 3. The light receiving device according to claim 1, wherein the imaging lens is provided in the first optical waveguide structure.

6. 3. The light receiving device according to claim 1, wherein the side surface of the first optical waveguide structure is a total reflection surface.

7. 3. The light receiving device according to claim 1, wherein a side surface of the first optical waveguide structure sandwiched between two adjacent light receiving modules, in a range from the imaging lens to the photoelectric conversion element, is a partially reflective surface.

8. 5. The light-receiving device according to claim 4, wherein a range between a rear-end fly-eye lens of the pair of fly-eye lenses and the imaging lens on a side surface of the first optical waveguide structure sandwiched between two adjacent light-receiving modules is a partially reflective surface.

9. a light source device that emits a light beam; The light receiving device according to claim 1 or 2; An optical power supply system comprising:

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