Optical components for sensors and sensing systems

Abstract

To provide an optical component for a sensor capable of realizing a sensing system configured to detect a change on a surface of an adherend, with an easy and inexpensive operation to attach to the adherend, also to provide a sensing system equipped with the optical component for a sensor.SOLUTION: An optical component for a sensor includes: an optical waveguide having a core layer including a long-sized sensing core part and also having a first face and a second face in a front-back relation with each other, in which the first face is to be attached to an adherend; and a light reflection part disposed at the sensing core part and configured to reflect light transmitted through the sensing core part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical component for a sensor and a sensing system. [Background technology]

[0002] Patent Document 1 discloses an optical fiber sensor that uses light to monitor the displacement or deformation of a monitoring target. This optical fiber sensor includes a pair of connecting members, an optical fiber holding part provided on each connecting member, and an optical fiber held by the optical fiber holding part.

[0003] With such optical fiber sensors, Fresnel reflection and increased loss are not observed under normal conditions. However, when relative displacement occurs between the connecting members, the optical fiber holding part deforms, causing deformation or breakage of the optical fiber, resulting in the observation of Fresnel reflection and increased loss. Based on these observation results, the user of the optical fiber sensor can identify abnormalities in the monitored object. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-99755 Summary of the Invention [Problem to be solved by the invention]

[0005] In the invention described in Patent Document 1, both ends of an optical fiber are connected to a monitoring unit. Therefore, the optical fiber needs to be laid in a ring shape, which places restrictions on the laying route and makes the laying work time-consuming. Furthermore, because optical fibers are linear bodies with circular cross sections, the work of attaching them to the monitored object is difficult. Furthermore, the length of the optical fiber needs to be at least twice the distance between the monitored object and the monitoring unit, which creates the problem of making it difficult to reduce costs.

[0006] An object of the present invention is to provide an optical component for a sensor that can realize a sensing system for detecting abnormalities in an adherend, and that is easy and inexpensive to install on the adherend, and a sensing system that includes such an optical component for a sensor. [Means for solving the problem]

[0007] Such objectives are as follows: (1) (9) This is achieved by the present invention. (1) An optical waveguide having a core layer including a long sensing core portion, a first surface and a second surface that are opposite each other, and the first surface is attached to an adherend; a light reflecting portion provided in the sensing core portion and configured to reflect light propagating through the sensing core portion; a socket provided on the second surface; Equipped with The core layer further comprises: an input core portion having an input end; an output core portion having an output end; a branching section that branches and connects the sensing core section to the incident core section and the emission core section; Including, the incident end has a function of reflecting light, the incident core portion is optically connected to the second surface via the incident end, The optical component for a sensor is characterized in that the socket is disposed at a position corresponding to the incident end.

[0008] (2) The optical component for a sensor according to (1) above, wherein the light reflecting portion includes a metal body adjacent to the sensing core portion.

[0009] (3) the incident end has a function of reflecting light, The incident core portion is optically connected to the second surface via the incident end. An optical component for a sensor according to (1) or (2) above. (4) a through hole penetrating the optical waveguide; an opening portion that opens to the socket and has a shape corresponding to the through hole; and The optical component for a sensor according to any one of (1) to (3) above, wherein the through hole and the opening overlap when the second surface is viewed in plan.

[0010] (5) An optical waveguide having a core layer including a long sensing core portion, a first surface and a second surface that are opposite each other, and the first surface is attached to an adherend; a light reflecting portion provided in the sensing core portion and configured to reflect light propagating through the sensing core portion; Covering the optical waveguide Good flexibility A coating portion; Equipped with The optical component for a sensor, wherein the light reflecting portion is provided on the covering portion.

[0011] (6) The above (5) comprising a coating adhesive layer that bonds the optical waveguide and the coating. ) The optical component for the sensor is as described above.

[0012] (7) The above (1) to (3) having an uncured adherend adhesive layer provided on the first surface. (6) 10. An optical component for a sensor according to any one of the preceding items.

[0018] (8) Above (1) or (7) an optical component for a sensor according to any one of the items above; a photoelectric conversion module optically connected to the optical waveguide; A sensing system comprising:

[0019] (9) an optical component for a sensor, the optical component comprising: an optical waveguide having a core layer including a long sensing core portion, and having a first surface and a second surface that are opposite each other, the first surface being attached to an adherend; and a light reflecting portion provided in the sensing core portion and reflecting light propagating through the sensing core portion; a photoelectric conversion module optically connected to the optical waveguide; Equipped with The sensing system is characterized in that the optical component for the sensor has a fitting portion into which the photoelectric conversion module is fitted. [Effects of the Invention]

[0020] According to the present invention, it is possible to realize a sensing system that detects changes in the surface of an adherend, and to obtain an inexpensive optical component for a sensor that can be easily attached to an adherend.

[0021] Furthermore, according to the present invention, since the optical component for a sensor as described above is provided, a sensing system that is easy to attach to an adherend and inexpensive can be obtained. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is an exploded perspective view showing an outline of a sensing system according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the sensing system shown in FIG. [Figure 3] FIG. 3 is a plan view illustrating the operation of the sensing system shown in FIG. 2. [Figure 4] FIG. 3 is a plan view illustrating the operation of the sensing system shown in FIG. 2. [Figure 5] FIG. 3 is a partially enlarged view of FIG. 2. [Figure 6] FIG. 6 is a partially enlarged perspective view of the optical waveguide shown in FIG. [Figure 7] 2 is a plan view of an optical waveguide included in the optical component for a sensor shown in FIG. 1. FIG. [Figure 8] 2 is an exploded perspective view of the coating and the optical waveguide shown in FIG. 1. FIG. [Figure 9] FIG. 10 is a cross-sectional view showing an optical component for a sensor according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing an optical component for a sensor according to a third embodiment. [Figure 11] FIG. 3 is a cross-sectional view showing the state in which the optical component for a sensor shown in FIG. 2, with the covering portion omitted, is attached to an adherend having a curved surface. [Figure 12]FIG. 10 is a plan view showing an optical component for a sensor according to a fourth embodiment. [Figure 13] FIG. 10 is a perspective view showing a sensing system according to a fifth embodiment. [Figure 14] FIG. 2 is a perspective view for explaining a method of assembling the sensing system shown in FIG. [Figure 15] FIG. 2 is a perspective view for explaining a method of assembling the sensing system shown in FIG. [Figure 16] FIG. 2 is a perspective view for explaining a method of assembling the sensing system shown in FIG. [Figure 17] FIG. 2 is a perspective view for explaining a method of assembling the sensing system shown in FIG. [Figure 18] FIG. 2 is a perspective view for explaining a method of assembling the sensing system shown in FIG. [Figure 19] FIG. 2 is a perspective view for explaining a method of assembling the sensing system shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The optical component for a sensor and the sensing system of the present invention will be described in detail below with reference to preferred embodiments shown in the accompanying drawings.

[0024] 1. First embodiment First, a sensing system 100 according to the first embodiment will be described.

[0025] Fig. 1 is an exploded perspective view showing an outline of a sensing system 100 according to a first embodiment. Fig. 2 is a cross-sectional view of the sensing system 100 shown in Fig. 1. Figs. 3 and 4 are plan views each explaining the operation of the sensing system 100 shown in Fig. 2.

[0026] In each figure, three mutually orthogonal axes are set: the X-axis, the Y-axis, and the Z-axis, which are indicated by arrows. The tip of the arrow is called the "plus side," and the base is called the "minus side." Furthermore, the tip of the arrow representing the Z-axis is called "up," and the base is called "down."

[0027] The sensing system 100 shown in Fig. 1 includes an optical component for a sensor 1, a photoelectric conversion module 52, and a control unit 54. As shown in Figs. 1 and 2, the optical component for a sensor 1 includes an optical waveguide 10 having a first surface 109 and a second surface 110 that are opposite surfaces, and is used with the first surface 109 attached to an adherend 9. The photoelectric conversion module 52 is optically connected to the optical waveguide 10 and has the function of converting optical signals into electrical signals and vice versa.

[0028] According to such a sensing system 100, changes in the surface of the adherend 9 can be detected simply by attaching the optical component for sensors 1 to the adherend 9. This makes it possible to realize a sensing system 100 that is inexpensive and easy to install. Furthermore, as will be described in detail later, it is possible to realize a sensing system 100 that has the advantage of making it difficult to overlook the occurrence of abnormalities.

[0029] Each part of the sensing system 100 will be described in detail below. 1.1.Optical components for sensors 1 and 2, the optical component for a sensor 1 includes an optical waveguide 10, a socket 3, and a covering portion 4. The socket 3 is provided on the second surface 110 of the optical waveguide 10, and is interposed in the optical connection between the photoelectric conversion module 52 and the optical waveguide 10. The covering portion 4 is provided so as to cover the optical waveguide 10.

[0030] As described above, the optical component for sensors 1 is used in a state where it is attached to an adherend 9. "Attached" refers to a state where at least the optical waveguide 10 of the optical component for sensors 1 is in close contact with the adherend 9. "Close contact" refers to a state where it is pressed against the adherend 9 by an external force, or a state where it is adhered to the adherend 9 by adhesive force, etc.

[0031] In this embodiment, as shown in Fig. 2, the optical component for sensors 1 is adhered to the adherend 9 via an adherend adhesive layer 21. This realizes a sensing system 100 that detects changes occurring in the adherend 9 via the optical component for sensors 1. Examples of changes occurring in the adherend 9 include mechanical, thermal, and chemical changes.

[0032] In the sensing system 100, light is incident on the optical component for sensor 1, and these changes occurring in the adherend 9 are detected based on changes in the intensity of the light that is reflected and returned. Specifically, with the optical component for sensor 1 attached to the adherend 9, incident light L1 is continuously or intermittently incident on the optical component for sensor 1 from the photoelectric conversion module 52, as shown in FIG. 2. The incident light L1 is reflected inside the optical component for sensor 1 and, as shown in FIG. 3, returns as emitted light L2 along the same path as the incident light L1. The sensing system 100 monitors the intensity of this emitted light L2.

[0033] When the incident light L1 is incident on the adherend 9, if the aforementioned change, for example, the crack 91 shown in FIG. 4, occurs on the surface of the adherend 9, a portion of the optical waveguide 10 included in the optical component for a sensor 1 also breaks, creating a fracture surface 8. As a result, the incident light L1 is reflected at the fracture surface 8, generating the reflected light L3 shown in FIG. 4. When this reflected light L3 is generated, the intensity of the emitted light L2 decreases compared to before the fracture surface 8 was generated. The sensing system 100 detects the occurrence of the fracture surface 8 by detecting the change in the intensity of the emitted light L2. This allows the sensing system 100 to estimate the occurrence of the crack 91. Even if the fracture does not occur, for example, if the optical waveguide 10 is stretched, bent, or compressed, reflected light L3 or leakage light is generated, causing a decrease in the intensity of the emitted light L2.

[0034] 1.1.1. Optical waveguide Fig. 5 is a partially enlarged view of Fig. 2. Fig. 6 is a partially enlarged perspective view of the optical waveguide 10 shown in Fig. 5. Fig. 7 is a plan view of the optical waveguide 10 included in the optical component for a sensor 1 shown in Fig. 1.

[0035] 5 and 6, the optical waveguide 10 includes a sheet member 16 formed by laminating, from the bottom, a first cover layer 18, a cladding layer 11, a core layer 13, a cladding layer 12, and a second cover layer 19 in this order. Each layer of the sheet member 16 extends parallel to the XY plane. In the core layer 13, as shown in FIG. 6, an elongated core portion 14 extending along the Y axis and a side cladding portion 15 adjacent to the side of the core portion 14 are formed.

[0036] The planar shape of the optical waveguide 10 is a strip with its major axis parallel to the Y axis, as shown in Fig. 7. This shape is not particularly limited, and may be a polygon such as a square or hexagon, a circle such as a perfect circle, an ellipse, or an oval, or any other shape. In this specification, "planar view" refers to a view from the Z axis.

[0037] As shown in Fig. 5, the optical waveguide 10 is attached to the surface of the adherend 9 with the lower surface of the first cover layer 18, i.e., the first surface 109, serving as the adhesive surface. If necessary, an adherend adhesive layer 21 shown in Fig. 5 may be interposed between the first surface 109 and the adherend 9. This allows the optical waveguide 10 to be fixed to the adherend 9. In this embodiment, not only the optical waveguide 10 but also the covering portion 4 is adhered to the adherend 9 via the adherend adhesive layer 21.

[0038] Each part of the optical waveguide 10 will be described in further detail below. 6, the side surfaces of the core 14 are surrounded by the side cladding portions 15 and the cladding layers 11 and 12. The refractive index of the core 14 is higher than the refractive indexes of the side cladding portions 15 and the cladding layers 11 and 12. This allows light to be confined in the core 14 and propagated therethrough.

[0039] In the core layer 13, the refractive index distribution in a plane perpendicular to the optical path of the core portion 14 may be any distribution, for example, a so-called step index (SI) type distribution in which the refractive index changes discontinuously, or a so-called graded index (GI) type distribution in which the refractive index changes continuously.

[0040] The cross-sectional shape of the core portion 14 in the YZ plane, i.e., the transverse cross-sectional shape of the core portion 14, is not particularly limited, but examples include circles such as perfect circles, ellipses, and ovals, polygons such as triangles, squares, pentagons, and hexagons, and other irregular shapes.

[0041] The average thickness of the core layer 13 is not particularly limited, but is preferably about 1 to 200 μm, more preferably about 5 to 100 μm, and even more preferably about 10 to 70 μm, which ensures the optical properties and mechanical strength required for the core layer 13.

[0042] Examples of the constituent material (main material) of the core layer 13 include various resin materials such as acrylic resins, methacrylic resins, polycarbonate, polystyrene, cyclic ether resins such as epoxy resins and oxetane resins, polyamide, polyimide, polybenzoxazole, polysilane, polysilazane, silicone resins, fluorine-containing resins, polyurethane, polyolefin resins, polybutadiene, polyisoprene, polychloroprene, polyesters such as PET and PBT, polyethylene succinate, polysulfone, polyether, and cyclic olefin resins such as benzocyclobutene resins and norbornene resins. Composite materials combining materials with different compositions may also be used as the resin material. In this specification, the term "main material" refers to a material that accounts for 50% or more by mass of the constituent materials, and preferably 70% or more by mass.

[0043] The average thickness of each of the cladding layers 11 and 12 is preferably about 1 to 200 μm, more preferably about 3 to 100 μm, and even more preferably about 5 to 60 μm, so that the optical properties and mechanical strength required for the cladding layers 11 and 12 are ensured.

[0044] The main material of the clad layers 11 and 12 is selected appropriately from the materials listed above as the constituent materials of the core layer 13, for example. The cladding layers 11 and 12 may be provided as needed, and may be omitted.

[0045] The optical waveguide 10 has cladding layers 11 and 12, which allows a stable refractive index difference to be formed and maintained between the core 14 and the outside thereof, thereby further improving the transmission efficiency of the core 14. Note that either or both of the cladding layers 11 and 12 may be integrated with the side cladding portion 15.

[0046] The first cover layer 18 is provided on the lower surface of the cladding layer 11. The second cover layer 19 is provided on the upper surface of the cladding layer 12. By providing such first cover layer 18 and second cover layer 19, the core layer 13 and the cladding layers 11 and 12 can be protected, and a decrease in the transmission efficiency of the core section 14 due to the external environment, etc. can be suppressed.

[0047] The average thickness of first cover layer 18 and second cover layer 19 is not particularly limited, but is preferably about 1 to 200 μm, more preferably about 3 to 100 μm, and even more preferably about 5 to 50 μm.

[0048] The first cover layer 18 and the second cover layer 19 may have the same or different configurations. For example, the first cover layer 18 and the second cover layer 19 may have the same or different average thicknesses. At least one of the first cover layer 18 and the second cover layer 19 may be provided as needed and may be omitted.

[0049] Examples of the main material of the first cover layer 18 and the second cover layer 19 include materials containing various resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethylene, polyolefin such as polypropylene, polyimide, polyamide, etc.

[0050] Of these, it is preferable that the main material of each of the first cover layer 18 and the second cover layer 19 is polyimide resin. Polyimide resin has a relatively high elastic modulus and a high thermal decomposition temperature, and therefore has sufficient durability against external forces and the external environment.

[0051] If necessary, fillers, antioxidants, UV absorbers, colorants, storage stabilizers, plasticizers, lubricants, anti-degradation agents, antistatic agents, etc. may be added to the constituent materials of first cover layer 18 and second cover layer 19. Of these, the addition of fillers makes it possible to adjust the thermal expansion coefficients of first cover layer 18 and second cover layer 19.

[0052] As shown in FIG. 7, the optical waveguide 10 has a light incident surface 141, a light reflecting surface 142, and a light emitting surface 143.

[0053] 2, two recesses that open to the bottom surface (first surface 109) are formed in the optical waveguide 10. The inner surfaces of the recesses intersect obliquely with the optical axis of the core portion 14, and parts thereof serve as a light incident surface 141 and a light emitting surface 143. In addition, a light reflecting surface 142 is provided on the end surface of the optical waveguide 10 on the positive side of the Y axis.

[0054] The light incident surface 141 is a mirror that converts the optical path of incident light L1 emitted from the photoelectric conversion module 52 and guides it to the core unit 14, as shown in FIG. 2. The light reflecting surface 142 is a surface that has the function of temporarily emitting the incident light L1 that has propagated through the core unit 14 to the outside and then allowing the light that has been reflected and returned to enter again. Specifically, the incident light L1 that has been emitted to the outside from the light reflecting surface 142 is reflected by the coating unit 4 and enters the core unit 14 again from the light reflecting surface 142 as emitted light L2, and propagates toward the light exit surface 143. The light exit surface 143 is a mirror that converts the optical path of the emitted light L2 that has propagated through the core unit 14 and guides it to the photoelectric conversion module 52, as shown in FIG. 2.

[0055] The core portion 14 includes an incident core portion 14a, a sensing core portion 14b, an emitting core portion 14c, and a branch portion 17. The branch portion 17 is located between the incident core portion 14a and the emitting core portion 14c and the sensing core portion 14b, and branches the sensing core portion 14b into the incident core portion 14a and the emitting core portion 14c.

[0056] The incident core portion 14a has a light incident surface 141 which is an incident end, and extends from the light incident surface 141 to the branching portion 17. The sensing core portion 14b has a light reflecting surface 142 which is an incident end, and extends from the light reflecting surface 142 to the branching portion 17. The emitting core portion 14c has a light emitting surface 143 which is an emitting end, and extends from the light emitting surface 143 to the branching portion 17.

[0057] The branching ratio of the branching section 17 is not particularly limited, but is preferably set so that when the output light L2 returning to the branching section 17 is split into two, the intensity of the light split to the output core section 14c is greater than the intensity of the light split to the input core section 14a. Specifically, when the branching ratio is the ratio of the intensity split to the output core section 14c to the intensity of the light split to the input core section 14a, the branching ratio of the branching section 17 is preferably 60 / 40 or more, and more preferably 70 / 30 or more and 95 / 5 or less. This makes it possible to increase the S / N ratio (signal-to-noise ratio) of the received light signal and more accurately detect changes in the intensity of the received light signal due to changes occurring in the adherend 9.

[0058] 7, the width of the portion on the negative Y-axis side of branching portion 17 is wider than the width of the portion on the positive Y-axis side of branching portion 17. This allows the width of socket 3 and the width of optical waveguide 10 to be closer together even if socket 3 is wide. As a result, socket 3 can be fixed to optical waveguide 10 more stably.

[0059] Furthermore, if the light incident surface 141 and the light exit surface 143 are each mirrors, it becomes possible to place the photoelectric conversion module 52 above the optical waveguide 10. This makes the entire lower surface of the optical waveguide 10 flat. This facilitates the work of attaching the optical component for sensors 1 to the adherend 9 and improves adhesion to the adherend 9. As a result, it is possible to realize a sensing system 100 with excellent sensitivity for detecting changes that occur in the adherend 9.

[0060] It should be noted that light incident surface 141 and light exit surface 143 are not limited to mirrors as described above, and may be replaced by, for example, a bent waveguide or the like, or may be included in an end surface of core layer 13. Furthermore, light incident surface 141 may be a mirror, and light exit surface 143 may be replaced by something other than a mirror, or conversely, light exit surface 143 may be a mirror, and light incident surface 141 may be replaced by something other than a mirror.

[0061] The optical waveguide 10 also has two through holes 144. The planar shape of the through hole 144 is not particularly limited, but is circular in FIG. 7. The through holes 144 are used to align the socket 3 with respect to the optical waveguide 10 when assembling the optical component for a sensor 1. The two through holes 144 shown in FIG. 7 are arranged at positions facing each other with the light incident surface 141 and the light exit surface 143 in between. This makes it easier to determine a single position and orientation of the socket 3 with respect to the optical waveguide 10 within the XY plane.

[0062] Sockets As shown in Fig. 1, the socket 3 is provided between the optical waveguide 10 and the photoelectric conversion module 52. The socket 3 shown in Fig. 1 is frame-shaped and has a window 31 that penetrates the center along the Z axis, and two openings 32, 32 that penetrate the outside of the window 31 along the Z axis.

[0063] The window portion 31 is provided at a position corresponding to the light incident surface 141 and the light emitting surface 143. This allows the optical waveguide 10 and the photoelectric conversion module 52 to be optically connected via the window portion 31.

[0064] The two openings 32, 32 facilitate alignment of the socket 3 and the photoelectric conversion module 52. Specifically, the photoelectric conversion module 52 shown in FIG. 1 has two pins 532, 532 that protrude downward. By inserting these pins 532 into the openings 32, alignment of the photoelectric conversion module 52 with respect to the socket 3 is completed. This reduces optical coupling loss between the optical waveguide 10 and the photoelectric conversion module 52.

[0065] Furthermore, the socket 3 may have a structure that allows the photoelectric conversion module 52 to be detachably attached. This facilitates the work of attaching and detaching the photoelectric conversion module 52 to and from the socket 3. As a result, it becomes possible to attach the photoelectric conversion module 52 only when necessary, while the optical component for sensors 1 is attached to the adherend 9. This makes it possible to reduce the running costs of the sensing system 100. It also becomes possible to replace a broken photoelectric conversion module 52 or to share the photoelectric conversion module 52 between multiple optical components for sensors 1.

[0066] 1 is not particularly limited, but is preferably 1 mm or more and 20 mm or less, and more preferably 2 mm or more and 10 mm or less, which allows the socket 3 to have both sufficient mechanical strength and a sufficient thickness for alignment.

[0067] The two openings 32, 32 are provided at positions overlapping with the two through holes 144, 144 of the optical waveguide 10. That is, the socket 3 has openings 32 having a shape corresponding to the through holes 144 that penetrate the optical waveguide 10. When the upper surface (second surface 110) of the optical waveguide 10 is viewed in plan, the through holes 144 and the openings 32 overlap.

[0068] As a result, when fixing the socket 3 to the optical waveguide 10, by using a jig that can be inserted continuously from the through-hole 144 to the opening 32, the two can be easily aligned.

[0069] If alignment using a jig is not required, the two openings 32, 32 do not need to penetrate the socket 3. In this case, the two openings 32, 32 only need to be open on the top surface.

[0070] Furthermore, the number of openings 32 is not limited to two, and may be three or more. In this case, the number of through holes 144 and the number of pins 532 may also be three or more.

[0071] Examples of materials that can be used to form the socket 3 include metal materials, ceramic materials, and resin materials.

[0072] Among these, examples of the metal material include stainless steel, iron-based alloy, nickel-based alloy, aluminum alloy, magnesium alloy, brass, and the like. Examples of ceramic materials include alumina, zirconia, and silica.

[0073] Examples of resin materials include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer (EVA), cyclic polyolefins, modified polyolefins, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polyamideimide, polycarbonate (PC), poly-(4-methylpentene-1), ionomers, acrylic resins, acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer (AS resin), butadiene-styrene copolymer, polyoxymethylene, polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polycyclohexane terephthalate (PCT), polyethers, and polyether ketones ( Examples of the thermoplastic elastomer include PEK, polyether ether ketone (PEEK), polyetherimide, polyacetal (POM), polyphenylene oxide, modified polyphenylene oxide, polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, aromatic polyester (liquid crystal polymer), polytetrafluoroethylene, polyvinylidene fluoride, other fluorine-based resins, various thermoplastic elastomers such as styrene-based, polyolefin-based, polyvinyl chloride-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based elastomers, epoxy resin, phenolic resin, urea resin, melamine resin, unsaturated polyester, silicone resin, polyurethane, and the like, as well as blends and polymer alloys mainly composed of these, and these may be used alone or in combination of two or more.

[0074] From the viewpoint of rigidity, the resin material is preferably one selected from the group consisting of polyvinyl chloride, polycarbonate, acrylic resin, polyethylene terephthalate, and ABS resin. Because these have relatively high rigidity, they are useful as a material for forming the frame-shaped socket 3 shown in Fig. 1, or as a material for forming the socket 3 having the mechanical strength to withstand attachment and detachment operations.

[0075] 1.1.3. Covering FIG. 8 is an exploded perspective view of the covering portion 4 and the optical waveguide 10 shown in FIG.

[0076] 8, the covering portion 4 has a recess 41 that accommodates the optical waveguide 10. The recess 41 opens to the adhesive surface 40 of the covering portion 4.

[0077] In this embodiment, the end of the optical waveguide 10 on the positive side of the Y axis is covered with the covering portion 4. That is, the optical component 1 for a sensor includes the covering portion 4 that covers the end of the optical waveguide 10. Specifically, the end of the optical waveguide 10 on the positive side of the Y axis is housed in the recess 41.

[0078] The adhesive surface 40 where the recess 41 is open is the surface that is adhered to the adherend 9 via the adherend adhesive layer 21. Therefore, by adhering the adhesive surface 40 to the adherend 9 with the optical waveguide 10 housed in the recess 41, the sensing core portion 14b of the optical waveguide 10 is not exposed to the outside. For this reason, by using the covering portion 4, the sensing core portion 14b can be effectively protected from, for example, contact with foreign objects and the external environment.

[0079] Examples of materials that can be used to form the cover 4 include metal materials, ceramic materials, and resin materials. Specific examples of these materials are the same as those of the materials that can be used to form the socket 3.

[0080] On the other hand, the covering portion 4 may be flexible. In this case, by covering the flexible optical waveguide 10 with the flexible covering portion 4, the optical component for sensors 1 can be easily attached to a curved surface. When a film-like covering portion 4 is used, by adhering the covering portion 4 to the adherend 9, the optical waveguide 10 can be easily attached to the adherend 9. This makes it easier to omit the adherend adhesive layer 21. However, from the viewpoints of durability and sensitivity for detecting changes in the adherend 9, it is preferable that the covering portion 4 has rigidity. The covering portion 4 may be provided as needed, and may be omitted.

[0081] 1.1.4.Light reflecting part In this embodiment, of the recess 41 of the covering portion 4 shown in Fig. 8, the surface that intersects with the Y axis constitutes the light reflecting portion 7. Incident light L1 emitted from the light reflecting surface 142 of the optical waveguide 10 is reflected by the light reflecting portion 7 and enters the core portion 14 from the light reflecting surface 142 again as emitted light L2. Therefore, the light reflecting portion 7 is provided adjacent to the sensing core portion 14b.

[0082] Such a function of the light reflecting portion 7 may be based on the light reflectivity of the material that constitutes the covering portion 4, or may be based on a light reflecting material provided on the inner surface of the recess 41.

[0083] In the former case, the light reflectivity may be increased by polishing the inner surface of the recess 41. In the latter case, examples of the light reflecting material include metal materials, ceramic materials, resin materials, silicon materials, glass materials, etc., and composite materials of these materials may also be used.

[0084] 1.1.5.Adhesive layer As shown in FIG. 5, a covering adhesive layer 22 is provided between the optical waveguide 10 and the recess 41.

[0085] The covering adhesive layer 22 bonds the vicinity of the light reflecting surface 142 of the optical waveguide 10 to the recess 41. In the present embodiment, as an example, the light reflecting surface 142 and the upper surface (second surface 110) of the optical waveguide 10 are bonded to the inner surface of the recess 41 by the covering adhesive layer 22.

[0086] Examples of adhesives that can be used to form the covering adhesive layer 22 include acrylic adhesives, urethane adhesives, silicone adhesives, and epoxy adhesives, as well as various polyester and modified olefin hot melt adhesives.

[0087] On the other hand, in this embodiment, the central portion 145 in the Y-axis direction of the optical waveguide 10 is not bonded to the coating 4. This central portion 145 is a portion corresponding to the sensing core portion 14b, and is attached to a position on the surface of the adherend 9 where it is desired to detect a change. Therefore, the central portion 145 is a portion where the aforementioned fracture surface 8 is expected to occur. Therefore, by not bonding the central portion 145 to the coating 4, it is possible to make the fracture surface 8 occur more easily. As a result, the detection sensitivity of the crack 91 in the sensing system 100 can be improved.

[0088] Here, the total length of the recess 41 in the Y-axis direction is L41, and the length of the recess 41 that is bonded by the covering portion adhesive layer 22 is L22.

[0089] The ratio of L22 / L41 is not particularly limited, but is preferably 0.4 or less, more preferably 0.01 to 0.35, and even more preferably 0.05 to 0.25. This makes it possible to achieve both the adhesive strength of the covering portion adhesive layer 22 and the detection sensitivity and detection range by ensuring sufficient length in the central portion 145. As a result, it is possible to realize a sensing system 100 that is both easy to use and reliable.

[0090] In addition, the total length of the sensing core portion 14b is set appropriately depending on the detection sensitivity and detection range of the crack 91 in the sensing system 100, the handleability of the optical component 1 for the sensor, etc., but as an example, it is preferably 20 mm or more and 1000 m or less, more preferably 50 mm or more and 500 m or less, and even more preferably 100 mm or more and 100 m or less.

[0091] In this embodiment, the covering adhesive layer 22 is filled between the light reflecting surface 142 and the light reflecting portion 7. Therefore, it is preferable that the covering adhesive layer 22 also has light transparency.

[0092] The above configuration is not essential, and the central portion 145 may also be bonded with an adhesive. In this case, the adhesive that bonds the central portion 145 may be the same as that used for the cover adhesive layer 22, but it is preferable to use an adhesive whose acidity after curing is lower than the elastic modulus of the cover adhesive layer 22 after curing, specifically, 90% or less. This ensures that the central portion 145 is prone to fracture surfaces 8, while integrating the optical waveguide 10 with the cover 4 and improving reliability.

[0093] The covering portion adhesive layer 22 may be provided as needed or may be omitted. In this case, for example, the optical waveguide 10 and the covering portion 4 may be individually adhered to the adherend 9 via the adherend adhesive layer 21 described later, thereby fixing these components to each other.

[0094] An adherend adhesive layer 21 is provided between the optical waveguide 10 and the adherend 9 . 2 and 5 is interposed between the optical waveguide 10 and the adherend 9. The adherend adhesive layer 21 may be provided in advance on the optical waveguide 10 side. That is, the optical component for sensors 1 may have an uncured adherend adhesive layer 21 provided on the lower surface (first surface 109) of the first cover layer 18. This allows the optical component for sensors 1 to be attached to the adherend 9 efficiently.

[0095] Examples of adhesives that can be used to form the adherend adhesive layer 21 include acrylic adhesives, urethane adhesives, silicone adhesives, and epoxy adhesives, as well as various polyester and modified olefin hot melt adhesives.

[0096] The uncured adherend adhesive layer 21 may be liquid, solid, or semi-solid in an uncured state, or may be in a state in which a curing reaction has partially progressed. Furthermore, when the adhesive constituting the adherend adhesive layer 21 contains a curable material, the curing principle may be thermosetting or photocuring. Furthermore, the uncured adherend adhesive layer 21 may be provided on the entire underside of the first cover layer 18, or on only a portion of it. The thickness of the cured adherend adhesive layer 21 is not particularly limited, but is preferably 1 to 100 μm, and more preferably 5 to 60 μm.

[0097] 1.1.6. Advantages of the First Embodiment As described above, the optical component for sensors 1 according to this embodiment includes an optical waveguide 10 and a light reflecting portion 7. The optical waveguide 10 has a core layer 13 that includes an elongated sensing core portion 14b, and has a first surface 109 and a second surface 110 that are opposite surfaces, with the first surface 109 being attached to an adherend 9. The light reflecting portion 7 is provided in the sensing core portion 14b and reflects light propagating through the sensing core portion 14b.

[0098] With this configuration, when incident light L1 is made incident continuously or intermittently, the incident light L1 can be reflected inside the optical component for sensor 1 and emitted as output light L2. Therefore, when some change occurs on the surface of the adherend 9, the sensing system 100 including the optical component for sensor 1 can detect the change on the surface of the adherend 9 based on the change in the intensity of the output light L2.

[0099] In addition, in the optical component for sensors 1, incident light L1 and outgoing light L2 travel back and forth within a single optical waveguide 10. Therefore, the optical component for sensors 1 has a simple structure, and it is easy to reduce manufacturing costs. In addition, since the optical component for sensors 1 does not require the installation of optical wiring for both directions, it is easy to attach the optical component for sensors 1 to an adherend 9.

[0100] Furthermore, because the optical waveguide 10 corresponds to the sensing section, the size of the surface of the adherend 9 to be monitored can be changed simply by changing the length of the optical waveguide 10. Therefore, the optical component for sensors 1 can easily optimize the sensing section according to the object to be monitored.

[0101] The sensing system 100 also monitors the intensity of the emitted light L2 and detects a decrease in the intensity of the emitted light L2 associated with the occurrence of a fracture surface 8, thereby inferring the occurrence of an abnormality in the adherend 9. In other words, the sensing system 100 equipped with the optical component for sensor 1 is a normally closed system configured to emit the emitted light L2 under normal conditions. In such a system, a decrease in the intensity of the emitted light L2 occurs when a malfunction occurs in the optical component for sensor 1 or the photoelectric conversion module 52. Therefore, the control unit 54 can detect an abnormality associated with a decrease in intensity not only when a change in the surface of the adherend 9 is detected, but also when such a malfunction occurs. Therefore, the control unit 54 can notify the user of the occurrence of an abnormality and prompt them to take some kind of action. Therefore, in such a system, the possibility of an abnormality being overlooked is low.

[0102] In contrast, a system that does not emit the emitted light L2 under normal circumstances is referred to here as a normally open system. In such a system, if the optical component 1 for the sensor or the photoelectric conversion module 52 fails, the emitted light L2 will not be emitted. In such a system, the control unit 54 cannot distinguish between a normal state and a failed state. For this reason, the user may not notice the occurrence of a failure. As a result, even if a failure occurs in the photoelectric conversion module 52, for example, the failure may be left unattended, and any change that occurs on the surface of the adherend 9 may be overlooked.

[0103] Therefore, a normally closed system is useful in that it is less likely that an abnormality will be overlooked.

[0104] Furthermore, in the case of a normally open system, reflected light that occurs when a change occurs on the surface of the adherend 9 is detected, but the intensity of the reflected light may become significantly small depending on the mode of change that occurs on the adherend 9. In this case, the change in intensity may not be captured sufficiently, and the detection sensitivity may decrease.

[0105] In contrast, a normally closed system does not detect reflected light L3 that occurs in conjunction with changes in the surface of the adherend 9, but rather detects changes in the intensity of emitted light L2 that occurs inside the optical component for the sensor 1. For this reason, a normally closed system is more susceptible to intensity changes than a normally open system, and has superior detection sensitivity.

[0106] The mounting method of the optical component for sensors 1 may be optimized depending on the characteristics of the adherend 9. For example, as shown in FIG. 4, when the angle θ between the fracture surface 8 and the core portion 14 is defined as θ, the angle θ is preferably 10 to 90°, more preferably 20 to 90°, from the viewpoint of detection sensitivity. Even if the angle θ is within this range, it is preferable that it is not within the range of 40 to 50°. If the angle θ is 40 to 50°, the reflected light L3 shown in FIG. 4 may be reflected again by the side surface of the core layer 13 (the surface of the core layer 13 intersecting the X-axis) and generate return light via the fracture surface 8. This may result in a situation where the reflected light L3 behaves like the emitted light L2, even though the fracture surface 8 has been formed. This may prevent the detection of a decrease in the intensity of the emitted light L2, and thus the occurrence of a crack 91.

[0107] Therefore, if the adherend 9 has a tendency for cracks 91 to occur in a specific direction, it is preferable to set the angle between that direction and the core portion 14 to an angle in the range of 10 to 90° and not 40 to 50°, thereby preventing a decrease in detection sensitivity.

[0108] The optical waveguide 10 may have a structure that partially reduces the mechanical strength, if necessary. By providing such a structure, if a change occurs in the surface of the adherend 9, a fracture surface 8 is more likely to occur starting from the structure. In other words, such a structure can be said to be a fragile structure that breaks easily. By providing such a fragile structure, the threshold stress required to generate the fracture surface 8 can be lowered, thereby further improving detection sensitivity.

[0109] Furthermore, it is preferable that the frangible structure extends linearly, which makes it possible to control the direction of propagation of fracture surface 8. For this reason, the angle formed between the extension direction of the frangible structure and core portion 14 is preferably in the range of 10 to 90°, and not in the range of 40 to 50°.

[0110] Furthermore, in this embodiment, as described above, a part of the covering 4 constitutes the light reflecting portion 7. Specifically, the inner surface of the recess 41 of the covering 4 has light reflectivity, and therefore reflects the incident light L1 emitted from the optical waveguide 10 facing this inner surface. With this configuration, there is no need to provide an optical reflecting film or the like on the optical waveguide 10, and the ease of manufacturing the optical waveguide 10 can be improved.

[0111] As described above, the optical component for sensors 1 according to this embodiment includes the coating adhesive layer 22 that bonds the optical waveguide 10 and the coating 4. By including such a coating adhesive layer 22, the optical waveguide 10 and the coating 4 can be integrated. As a result, the optical component for sensors 1 can be easily handled and the reliability of the optical component for sensors 1 can be further improved.

[0112] The core layer 13 also includes an incident core portion 14a, an emitting core portion 14c, and a branching portion 17. The incident core portion 14a has a light incident surface 141 which is an incident end. The emitting core portion 14c has a light emitting surface 143 which is an emitting end. The branching portion 17 branches the sensing core portion 14b into the incident core portion 14a and the emitting core portion 14c and connects them.

[0113] According to this configuration, the light incident surface 141 and the light exit surface 143 are individually provided for each sensing core 14b in one optical waveguide 10, so that the light emitting element 521 and the light receiving element 522 can be coupled to the optical waveguide 10 without interfering with each other. In other words, the light emitting element 521 and the light receiving element 522 can be comfortably arranged in the photoelectric conversion module 52. This enables the structure of the photoelectric conversion module 52 to be simplified.

[0114] The above configuration may be omitted. In this case, it is sufficient that a mechanism for splitting the output light L2 is provided outside the optical waveguide 10. In other words, it is sufficient that the photoelectric conversion module 52 has the function of separating the input light L1 and the output light L2.

[0115] Furthermore, in this embodiment, the light incident surface 141, which is the incident end, has a function of reflecting light. In other words, the light incident surface 141 functions as a mirror. The incident core portion 14a is optically connected to the upper surface (second surface 110) of the optical waveguide 10 via the light incident surface 141.

[0116] This makes it possible to place the light emitting element 521 above the optical waveguide 10. As a result, it is no longer necessary to provide a light emitting element on the lower surface (first surface 109) of the optical waveguide 10, which facilitates the operation of attaching the optical component for the sensor 1 to the adherend 9. In addition, since gaps are less likely to occur between the optical component for the sensor 1 and the adherend 9, the sensitivity for detecting changes in the surface of the adherend 9 can be increased.

[0117] In this embodiment, the light emitting surface 143, which is the emitting end, has a function of reflecting light. In other words, the light emitting surface 143 functions as a mirror. The emitting core portion 14c is optically connected to the upper surface (second surface 110) of the optical waveguide 10 via the light emitting surface 143.

[0118] This makes it possible to arrange the light receiving element 522 above the optical waveguide 10. As a result, it is no longer necessary to provide a light receiving element on the lower surface (first surface 109) of the optical waveguide 10, which facilitates the operation of attaching the optical component for sensing 1 to the adherend 9. Furthermore, since gaps are less likely to occur between the optical component for sensing 1 and the adherend 9, the sensitivity for detecting changes in the surface of the adherend 9 can be increased.

[0119] The optical component for sensors 1 according to this embodiment also includes a socket 3 provided on the upper surface (second surface 110) of the optical waveguide .

[0120] As a result, for example, if the socket 3 is provided with a structure that enables coupling with the photoelectric conversion module 52, the optical waveguide 10 and the photoelectric conversion module 52 can be easily coupled via the socket 3. As a result, alignment can be easily performed, and optical coupling loss between the optical waveguide 10 and the photoelectric conversion module 52 can be reduced.

[0121] 1.2. Photoelectric conversion module The photoelectric conversion module 52 includes a light emitting element 521 , a light receiving element 522 , an amplifier 523 , an AD converter 524 , a substrate 525 , and a housing 526 .

[0122] The light emitting element 521 emits incident light L1 to be incident on the optical waveguide 10 of the optical component for a sensor 1. Examples of the light emitting element 521 include a semiconductor laser, a gas laser, and a light emitting diode.

[0123] The light receiving element 522 receives the emitted light L2 emitted from the optical waveguide 10 of the optical component for a sensor 1. Then, the light receiving element 522 outputs a current signal or the like according to the intensity of the emitted light L2 to the amplifier 523. Examples of the light receiving element 522 include a photodiode and a phototransistor.

[0124] The amplifier 523 converts into a voltage signal the current signal output from the light receiving element 522. As the amplifier 523, for example, a transimpedance amplifier (TIA) or the like can be used.

[0125] The AD converter 524 converts the analog signal output from the amplifier 523 into a digital signal. The converted digital signal is output to the control unit .

[0126] The substrate 525 is a wiring substrate on which the light-emitting element 521, the light-receiving element 522, the amplifier 523, the AD converter 524, and an external interface (not shown) are mounted. The substrate 525 has wiring (not shown). The wiring electrically connects the light-emitting element 521, the light-receiving element 522, the amplifier 523, the AD converter 524, and the external interface.

[0127] The light emitting element 521 and the light receiving element 522 are mounted on the lower surface of the substrate 525. This allows the light emitting element 521 and the light receiving element 522 to be optically connected to the optical waveguide 10.

[0128] The housing 526 houses the above-mentioned structure, thereby improving the weather resistance of the photovoltaic conversion module 52.

[0129] The power source for the photoelectric conversion module 52 may be an external power source or an internal power source. Examples of the internal power source include a primary battery and a secondary battery. Furthermore, the configuration of the photoelectric conversion module 52 is not limited to the above configuration.

[0130] 1.3.Control Unit The control unit 54 is capable of wired or wireless communication with the photoelectric conversion module 52. The control unit 54 outputs a control signal to control the operation of the photoelectric conversion module 52. The control unit 54 also receives a light-receiving signal output from the photoelectric conversion module 52, specifically a digital signal output from the AD converter 524. The control unit 54 has the function of analyzing the light-receiving signal, notifying the analysis result, and outputting a signal based on the analysis result, as necessary.

[0131] As an example of analyzing the received light signal, for example, a change in the intensity of the emitted light L2 is detected, and if the change in intensity exceeds a threshold value, it is assumed that an abnormal change has occurred in the adherend 9.

[0132] The control unit 54 is configured, for example, by hardware including a processor, memory, an external interface, and the like, all connected to one another via an internal bus. The functions of the control unit 54 are realized by the processor executing a program stored in the memory.

[0133] 2. Second embodiment Next, an optical component for a sensor according to a second embodiment will be described. FIG. 9 is a cross-sectional view showing an optical component for sensors 1A according to the second embodiment.

[0134] The second embodiment will be described below, focusing on the differences from the first embodiment, and the description of the similarities will be omitted. Note that in Fig. 9, the same components as those in the first embodiment are denoted by the same reference numerals as those previously described.

[0135] In the first embodiment described above, the coating adhesive layer 22 is filled between the optical waveguide 10 and the coating 4, whereas in this embodiment, as shown in FIG. 9, there is a cavity between the light reflecting surface 142 of the optical waveguide 10 and the light reflecting portion 7 of the coating 4.

[0136] In such a configuration, the reflectance of the light reflecting portion 7 can be made higher than that of the first embodiment depending on the light reflection principle of the light reflecting portion 7. Therefore, this embodiment is useful from the viewpoint of suppressing reflection loss in the light reflecting portion 7. In the second embodiment as described above, the same effects as in the first embodiment can be obtained.

[0137] 3. Third embodiment Next, an optical component for a sensor according to a third embodiment will be described. FIG. 10 is a cross-sectional view showing an optical component for sensors 1B according to the third embodiment.

[0138] The third embodiment will be described below, focusing on the differences from the first embodiment and omitting a description of similarities. Note that in Fig. 10, the same components as those in the first embodiment are denoted by the same reference numerals as those previously described.

[0139] In the first embodiment described above, a part of the covering portion 4 constitutes the light reflecting portion 7, whereas in this embodiment, as shown in Fig. 10, the light reflecting portion 7 includes a metal body 70 provided on the light reflecting surface 142. The metal body 70 is, for example, a metal film or a metal plate, and is provided so as to cover the light reflecting surface 142, that is, so as to be adjacent to the sensing core portion 14b.

[0140] Providing a light reflecting section 7 with such a configuration can increase the light reflectance of the light reflecting section 7. This increases the intensity of the emitted light L2, thereby increasing the range of change in intensity of the emitted light L2 when a fracture surface 8 occurs. As a result, the sensitivity of the sensing system 100 to detect changes in the surface of the adherend 9 can be increased.

[0141] Examples of the metal body 70 include a simple substance or an alloy of Al, Ag, Au, Pd, Sn, Ni, etc. The metal body 70 is formed by, for example, a vapor phase film deposition method, a liquid phase film deposition method, a plating method, a transfer method, etc. Alternatively, the metal body 70 may be fabricated by attaching a prepared metal plate to the light reflecting surface 142.

[0142] In the third embodiment, the same effects as in the first embodiment can be obtained. Note that although the metal body 70 shown in Fig. 10 is provided on the end face of the core portion 14, it may be provided in a recess provided midway through the core portion 14. Also, in this embodiment, the covering portion 4 can be omitted.

[0143] FIG. 11 is a cross-sectional view showing the state in which the optical component for sensors 1B shown in FIG. 2, without the covering portion 4, is attached to an adherend 9 having a curved surface 92. In FIG.

[0144] 11, the optical component for sensors 1B can be attached to an adherend 9 simply by attaching the flexible optical waveguide 10 to a curved surface 92. Therefore, the optical component for sensors 1B can be easily attached to adherends 9 having surfaces with various shapes.

[0145] 4. Fourth embodiment Next, an optical component for a sensor according to a fourth embodiment will be described. FIG. 12 is a plan view showing an optical component for sensors 1C according to the fourth embodiment.

[0146] The fourth embodiment will be described below, focusing on the differences from the third embodiment and omitting the description of the similarities. Note that in Fig. 12, the same components as those in the third embodiment are denoted by the same reference numerals as those previously described.

[0147] The fourth embodiment is similar to the third embodiment except that the optical waveguide 10 described above is divided into two optical waveguides 10-1 and 10-2, which are connected via an optical fiber part 6.

[0148] 12, the division position of the optical waveguides 10-1 and 10-2 is set to a position on the positive side of the Y axis from the branching portion 17. The portion on the negative side of the Y axis from this position is referred to as "optical waveguide 10-1," and the portion on the positive side of the Y axis is referred to as "optical waveguide 10-2."

[0149] An optical connector 146 is attached to the end of the optical waveguide 10-1 on the positive side of the Y axis, and an optical connector 147 is attached to the end of the optical waveguide 10-2 on the negative side of the Y axis.

[0150] The optical fiber component 6 includes a flexible optical fiber 61 and optical connectors 62, 62 attached to both ends of the optical fiber 61. One optical connector 62 is connected to the optical connector 146 described above, and the other optical connector 62 is connected to the optical connector 147 described above.

[0151] According to the above-described configuration, the sensing core portion 14b of the optical waveguide 10 can be located far away from the branch portion 17 via the optical fiber component 6. This allows a portion of the total length of the optical waveguide 10 to be replaced with the optical fiber component 6, even when it is desired to separate the position of the monitoring target from the photoelectric conversion module 52. As a result, the transmission loss of the entire optical component for sensor 1C can be reduced even if the total length is long. In the fourth embodiment as described above, the same effects as in the third embodiment can be obtained.

[0152] 5. Fifth embodiment Next, a sensing system according to a fifth embodiment will be described. FIG. 13 is a perspective view showing a sensing system 100D according to the fifth embodiment.

[0153] The fifth embodiment will be described below, focusing on the differences from the first embodiment, and a description of similarities will be omitted. Note that in Fig. 13, the same components as those in the first embodiment are denoted by the same reference numerals as those previously described.

[0154] In the sensing system 100 according to the first embodiment described above, as shown in Fig. 1, the pins 532 of the photoelectric conversion module 52 are inserted into the openings 32 of the socket 3 to align them. In contrast, in the sensing system 100D according to this embodiment, as shown in Fig. 13, the photoelectric conversion module 52 is fitted into the window 31 of the socket 3. That is, in the optical component 1D for a sensor shown in Fig. 13, the window 31 is a window through which the incident light L1 and the emitted light L2 pass, and also serves as a fitting portion into which the photoelectric conversion module 52 fits.

[0155] According to this configuration, the structure of the socket 3 and the structure of the photoelectric conversion module 52 are simpler than those in the first embodiment, which makes it possible to further reduce the manufacturing cost of the sensing system 100D. In the fifth embodiment as described above, the same effects as in the first embodiment can be obtained.

[0156] The structure for performing the alignment may be something other than the pin 532 and the window portion 31 described above.

[0157] 6. How to assemble the sensing system Next, an example of a method for assembling the sensing system will be described.

[0158] 14 to 19 are perspective views for explaining a method of assembling the sensing system shown in FIG.

[0159] First, as shown in Fig. 14, the optical waveguide 10 is combined with a jig 56. The jig 56 has a base 562 and two insertion portions 564, 564. The base 562 is plate-shaped and extends along the XY plane. The insertion portion 564 is rod-shaped and protrudes from the base 562 toward the positive side of the Z axis. However, the structure of the jig 56 is not limited to this.

[0160] 14, two insertion portions 564, 564 of the jig 56 are inserted into two through holes 144, 144 of the optical waveguide 10. As a result, the position and posture of the optical waveguide 10 in the XY plane relative to the jig 56 are determined as one unit, as shown in FIG.

[0161] Next, as shown in Fig. 16, the socket 3 is fitted to the insertion portions 564 of the jig 56 from the upper surface (second surface 110) side of the optical waveguide 10. Specifically, as shown in Fig. 16, the two insertion portions 564, 564 are inserted into the two openings 32, 32 of the socket 3. This determines a single position and orientation of the socket 3 in the XY plane relative to the jig 56, as shown in Fig. 17. Furthermore, a single position and orientation of the socket 3 relative to the optical waveguide 10 are also determined.

[0162] Thereafter, the socket 3 is bonded to the optical waveguide 10. For bonding, the various adhesives mentioned above are used.

[0163] Next, as shown in FIG. 18, the jig 56 is removed. This completes the optical component for a sensor 1. Thereafter, as shown in FIG. 19, the photoelectric conversion module 52 is assembled to the socket 3. This completes the position and orientation of the photoelectric conversion module 52 in the XY plane relative to the socket 3. Furthermore, the position and orientation of the photoelectric conversion module 52 relative to the optical waveguide 10 are also completes the position and orientation of the photoelectric conversion module 52 relative to the optical waveguide 10. In this manner, the sensing system 100 is completed.

[0164] Although the optical component for a sensor and the sensing system of the present invention have been described above based on the illustrated embodiments, the present invention is not limited to these.

[0165] For example, the optical components for sensors and sensing systems of the present invention may be such that each part of the above-described embodiments is replaced with any other configuration having the same function, or any other component may be added to the above-described embodiments.

[0166] The optical component for sensors of the present invention may further include a protective layer covering the adherend adhesive layer. This protective layer can be peeled off from the adherend adhesive layer immediately before bonding the optical component for sensors to the adherend, making it possible to easily prepare a clean bonding surface. This can prevent foreign matter from being caught in the adhesive layer, allowing for stronger adhesion. [Explanation of symbols]

[0167] 1 Optical components for sensors 1A Optical components for sensors 1B Optical components for sensors 1C Sensor Optical Components Optical components for 1D sensors 3 sockets 4 Covering 6. Fiber optic components 7 Light reflecting part 8 Fracture surface 9 Adherent 10 Optical waveguide 10-1 Optical waveguide 10-2 Optical waveguide 11 Cladding layer 12 Cladding layer 13 Core layer 14 Core section 14a Injection core 14b Sensing core 14c Output core 15 Side cladding 16 Sheet body 17 Branch 18 First Cover Layer 19 Second Cover Layer 21 Adherent adhesive layer 22 Covering adhesive layer 31 Window 32 Opening 40 Adhesive surface 41 Recess 52 Photoelectric conversion module 54 Control Unit 56 Jig 61 Optical Fiber 62 Optical Connector 70 Metal body 91 Crack 92 Curved surface 100 Sensing System 100D Sensing System 109 Page 1 110 2nd page 141 Light entrance surface 142 Light reflective surface 143 Light exit surface 144 Through Hole 145 Central part 146 Optical Connector 147 Optical Connector 521 Light-emitting element 522 Photodetector 523 Amplifier 524 AD converter 525 board 526 Case 532 pins 562 base 564 Insertion section L1 incident light L2 output light L3 reflected light L22 length L41 total length t3 thickness θ angle

Claims

1. an optical waveguide having a core layer including a long sensing core portion, a first surface and a second surface that are opposite surfaces to each other, the first surface being attached to an adherend; a light reflecting portion provided in the sensing core portion and configured to reflect light propagating through the sensing core portion; a socket provided on the second surface; Equipped with The core layer further comprises: an input core portion having an input end; an output core portion having an output end; a branching section that branches and connects the sensing core section to the incident core section and the emission core section; Including, the incident end has a function of reflecting light, the incident core portion is optically connected to the second surface via the incident end, The optical component for a sensor is characterized in that the socket is disposed at a position corresponding to the incident end.

2. The optical component for a sensor according to claim 1 , wherein the light reflecting portion includes a metal body adjacent to the sensing core portion.

3. the exit end has a function of reflecting light, 3. The optical component for a sensor according to claim 1, wherein the output core portion is optically connected to the second surface via the output end.

4. a through hole penetrating the optical waveguide; an opening portion that opens to the socket and has a shape corresponding to the through hole; and 4. The optical component for a sensor according to claim 1, wherein the through hole and the opening overlap when the second surface is viewed from above.

5. an optical waveguide having a core layer including a long sensing core portion, a first surface and a second surface that are opposite surfaces to each other, the first surface being attached to an adherend; a light reflecting portion provided in the sensing core portion and configured to reflect light propagating through the sensing core portion; a flexible covering portion that covers the optical waveguide; Equipped with The optical component for a sensor, wherein the light reflecting portion is provided on the covering portion.

6. 6. The optical component for a sensor according to claim 5, further comprising a coating adhesive layer that bonds the optical waveguide and the coating.

7. 7. The optical component for sensors according to claim 1, further comprising an uncured adherend adhesive layer provided on the first surface.

8. The optical component for a sensor according to any one of claims 1 to 7, a photoelectric conversion module optically connected to the optical waveguide; A sensing system comprising:

9. an optical component for a sensor, the optical component comprising: an optical waveguide having a core layer including a long sensing core portion, and having a first surface and a second surface that are opposite each other, the first surface being attached to an adherend; and a light reflecting portion provided in the sensing core portion and reflecting light propagating through the sensing core portion; a photoelectric conversion module optically connected to the optical waveguide; Equipped with The sensing system is characterized in that the optical component for the sensor has a fitting portion into which the photoelectric conversion module is fitted.

Images