Ferrule and optical connector
By introducing a ferrule structure with a first fiber slot and a second fiber slot into the optical connector, the problem of unreliable fiber assembly is solved, and efficient and precise fiber positioning and assembly workability are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUMITOMO ELECTRIC INDUSTRIES LTD
- Filing Date
- 2021-09-07
- Publication Date
- 2026-06-23
Smart Images
Figure CN116134354B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to ferrules and optical connectors.
[0002] This application claims priority based on Japanese Application No. 2020-161209, filed on September 25, 2020, and invokes all the contents set forth in that Japanese application. Background Technology
[0003] A conventional optical connector includes: a ferrule having a plurality of lenses at its tip; and a plurality of optical fibers inserted into the interior of the ferrule (see, for example, Patent Document 1). In such an optical connector, for example, a plurality of fiber slots are provided at positions corresponding to the plurality of lenses, each supporting one of the plurality of optical fibers. When assembling the optical fibers into the ferrule, the optical fibers are inserted into the interior of the ferrule through an opening formed at the rear end of the ferrule, and the optical fibers are positioned in the fiber slots. The optical fibers are supported by the fiber slots, thereby allowing the optical fibers to be positioned with high precision relative to the lenses.
[0004] Existing technical documents
[0005] Patent documents
[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-090974 Summary of the Invention
[0007] One embodiment of the ferrule disclosed includes: a top surface; an opening disposed on a side opposite to the top surface in a first direction intersecting the top surface; a plurality of fiber slots extending along the first direction between the top surface and the opening, and arranged side-by-side along a second direction intersecting the first direction, capable of supporting a plurality of optical fibers respectively; and a plurality of lenses respectively disposed on the extension lines of the plurality of fiber slots. The fiber slots have: a first fiber slot portion for positioning the optical fiber relative to the lens; and a second fiber slot portion for guiding the optical fiber into the first fiber slot portion. The first fiber slot portion is configured to be closer to the lens than the second fiber slot portion in the first direction.
[0008] One embodiment of the optical connector disclosed herein includes: the aforementioned ferrule; and a plurality of optical fibers, each supported by a plurality of fiber slots and respectively disposed on the optical axis of a plurality of lenses. Attached Figure Description
[0009] Figure 1 This is a perspective view of an optical connector according to one embodiment.
[0010] Figure 2 It means Figure 1 A cross-sectional view of the optical connector.
[0011] Figure 3 This is a perspective view of a ferrule in one embodiment.
[0012] Figure 4 It means Figure 3 A cross-sectional view of the ferrule.
[0013] Figure 5 It is Figure 4 An enlarged cross-sectional view of a portion of the ferrule.
[0014] Figure 6 It means Figure 3 Another cross-sectional view of the ferrule.
[0015] Figure 7A This is a cross-sectional view showing the straight section of the first fiber optic groove.
[0016] Figure 7B This is a cross-sectional view showing the straight section of the second fiber optic groove.
[0017] Figure 8 This is a cross-sectional view showing the tapered portion of the second fiber groove.
[0018] Figure 9A This is a cross-sectional view showing a modified example of the shape of the second fiber groove.
[0019] Figure 9B This is a cross-sectional view showing another variation of the shape of the second fiber groove.
[0020] Figure 9C This is a cross-sectional view showing another variation of the shape of the second fiber groove.
[0021] Figure 10 This is a three-dimensional diagram showing an optical connection structure equipped with an optical connector.
[0022] Figure 11 It means Figure 10 A top view of the optical connection structure.
[0023] Figure 12 It means Figure 10 Rear view of the optical connection structure.
[0024] Figure 13 This is a rear view showing a modified example of an adapter with an optical connection structure.
[0025] Figure 14 It means in Figure 13 The diagram shows the situation where an optical connector is inserted into the adapter. Detailed Implementation
[0026] [The problem this disclosure aims to solve]
[0027] In the optical connector described in Patent Document 1, when the fiber optic slot is difficult to see from the opening at the rear end of the ferrule, it may become difficult to reliably position the fiber inserted inside the ferrule within the fiber optic slot when assembling the fiber into the ferrule. In such cases, the fiber inserted inside the ferrule may collide with the wall between the fiber optic slot and the ferrule, potentially causing workability problems when assembling the fiber into the ferrule.
[0028] [The Effects of This Disclosure]
[0029] The ferrule and optical connector disclosed herein can improve workability during optical fiber assembly.
[0030] [Description of embodiments of this disclosure]
[0031] First, embodiments of the present disclosure will be described. One embodiment of the ferrule includes: a top surface; an opening disposed on a side opposite to the top surface in a first direction intersecting the top surface; a plurality of fiber slots extending between the top surface and the opening along the first direction and arranged side-by-side along a second direction intersecting the first direction, capable of supporting a plurality of optical fibers respectively; and a plurality of lenses disposed on extensions of the plurality of fiber slots. Each fiber slot has: a first fiber slot portion for positioning an optical fiber relative to a lens; and a second fiber slot portion for guiding an optical fiber into the first fiber slot portion. The first fiber slot portion is configured to be closer to the lens in the first direction than the second fiber slot portion.
[0032] In addition to a first fiber optic slot for positioning the fiber relative to the lens, the ferrule also has a second fiber optic slot for guiding the fiber into the first fiber optic slot. Furthermore, the first fiber optic slot is configured to be closer to the lens than the second fiber optic slot in a first direction. Therefore, when the fiber is inserted into the ferrule from the opening, the fiber is guided into the first fiber optic slot via the second fiber optic slot, where it is positioned relative to the lens. Thus, by having a second fiber optic slot to guide the fiber into the first fiber optic slot, collisions between the fiber and the fiber optic slot wall are reduced when the fiber is inserted into the ferrule, allowing the fiber to be reliably positioned within the first fiber optic slot. Therefore, the ferrule described above improves workability during fiber optic assembly.
[0033] Alternatively, in a cross-section perpendicular to the first direction, the first and second fiber slots are each V-shaped. In this case, the position of the fiber relative to the lens can be positioned with higher precision.
[0034] Alternatively, in a cross-section perpendicular to the first direction, the opening width of the second fiber groove is larger than the opening width of the first fiber groove. In this case, the allowable displacement of the fiber relative to the lens when supported by the second fiber groove can be ensured to be larger than the allowable displacement of the fiber relative to the lens when supported by the first fiber groove. Therefore, when inserting the fiber into the ferrule, after determining the approximate position of the fiber relative to the lens in the second fiber groove, the position of the fiber relative to the lens can be determined with high precision in the first fiber groove.
[0035] Alternatively, in a cross-section perpendicular to the first direction, the diameter of an imaginary circle centered on the optical axis of the lens and tangent to the second fiber groove is larger than the diameter of an imaginary circle centered on the optical axis of the lens and tangent to the first fiber groove. In this case, the allowable displacement of the fiber relative to the lens when supported by the second fiber groove can be ensured to be larger than the allowable displacement of the fiber relative to the lens when supported by the first fiber groove. Therefore, when inserting the fiber into the ferrule, after determining the approximate position of the fiber relative to the lens in the second fiber groove, the position of the fiber relative to the lens can be determined with high precision in the first fiber groove.
[0036] Alternatively, the second fiber optic slot may include: a straight section, at each position along the first direction, having a constant diameter of an imaginary circle centered on the optical axis of the lens and tangent to the second fiber optic slot; and a tapered section, disposed in the first direction opposite to the straight section to the first fiber optic slot, tilted such that the diameter of the imaginary circle centered on the optical axis of the lens and tangent to the second fiber optic slot increases as it moves away from the straight section. With such a tapered section, an optical fiber inserted from the opening into the ferrule can be reliably introduced into the straight section. Furthermore, with the straight section, the optical fiber's orientation can be stabilized along the first direction, allowing for smooth introduction of the optical fiber into the first fiber optic slot while maintaining this stable orientation. Therefore, according to the above configuration, the optical fiber can be reliably and smoothly introduced into the first fiber optic slot.
[0037] Alternatively, the total length of the second fiber groove in the first direction may be greater than or equal to the total length of the first fiber groove in the first direction. In this case, the fiber orientation can be stabilized more reliably in the second fiber groove.
[0038] Alternatively, in the first direction, the second fiber optic slot is configured at a predetermined interval from the first fiber optic slot. In this case, by forming the first fiber optic slot independently of the second fiber optic slot, the first fiber optic slot can be manufactured with high precision.
[0039] Alternatively, it may also include an upper surface disposed in a third direction intersecting the first and second directions, opposite to the plurality of fiber slots. Alternatively, the upper surface may have a window opening in a region opposite the first fiber slot in the third direction. Alternatively, when viewed from the third direction, the first fiber slot may be recessed inside the window. In this case, the window can be used not only as an injection window for injecting adhesive into the ferrule, but also for the alignment operation when introducing optical fibers into the first fiber slot. This further improves the workability during optical fiber assembly.
[0040] Alternatively, the aforementioned ferrule may also include a pair of side surfaces, which are positioned opposite each other in the second direction, separated by multiple fiber slots. Alternatively, each of the pair of side surfaces may have a guide portion for guiding insertion into the adapter along the first direction. In this case, the guide portions on the pair of side surfaces can be used for positioning the ferrule relative to the adapter. Thus, positioning the ferrule relative to the adapter can be achieved without using expensive guide pins.
[0041] One embodiment of the optical connector disclosed herein includes: any of the aforementioned ferrules; and a plurality of optical fibers, each supported by a plurality of fiber slots and respectively disposed on the optical axes of a plurality of lenses. Since this optical connector includes any of the aforementioned ferrules, the workability of assembling the optical fibers into the ferrules can be improved as described above.
[0042] Alternatively, in the optical connector described above, the optical fiber is fixed to the first fiber groove using an adhesive. In this case, fixing the position of the optical fiber relative to the lens using an adhesive allows for more reliable positioning of the optical fiber relative to the lens.
[0043] Alternatively, in the aforementioned optical connector, the ferrule may have an upper surface positioned opposite a plurality of fiber slots in a third direction intersecting the first and second directions. The upper surface may also have a window opening in a region opposite the first fiber slot in the third direction. Alternatively, a cover may be provided inside the window, positioned over the first fiber slot and separated from it. In this case, pressing the fiber into the first fiber slot using the cover further ensures reliable positioning of the fiber relative to the lens.
[0044] [Details of the embodiments of this disclosure]
[0045] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same elements or elements having the same function, and repeated descriptions are omitted.
[0046] Figure 1 This is a perspective view showing the optical connector 10 of this embodiment. Figure 2This is a cross-sectional view of the optical connector 10. For ease of understanding, an XYZ orthogonal coordinate system is shown in each figure. In this embodiment, the long dimension direction of the optical connector 10 is designated as the X direction (first direction), the short dimension direction of the optical connector 10 is designated as the Y direction (second direction), and the height direction of the optical connector 10 is designated as the Z direction (third direction). In the following description, for ease of explanation, directions will sometimes be referred to as "front" or "back". The X direction is defined as the direction from the optical connector 10 towards the optical connector 10 connected to the other (refer to...). Figure 10 Set the direction of ) to "forward" and its opposite direction to "backward".
[0047] like Figure 1 and Figure 2 As shown, the optical connector 10 includes: a plurality of optical fibers 20 (12 in this embodiment); and a ferrule 30 for inserting the front ends of the plurality of optical fibers 20. Each optical fiber 20 extends along the X direction and is arranged in a row along the Y direction. Each optical fiber 20 can be either multi-mode fiber (MMF) or single-mode fiber (SMF). The number of optical fibers 20 is not limited to 12; for example, it can be 4, 8, or 16, or other numbers.
[0048] The ferrule 30 holds multiple optical fibers 20. The ferrule 30 has, for example, a generally cuboid shape. The ferrule 30 has a lens portion 31 at its front end. The ferrule 30 is integrally formed with the lens portion 31, for example. That is, the ferrule 30 is formed integrally with the lens portion 31. Therefore, the ferrule 30 is made of the same material as the lens portion 31, i.e., a material that provides the light transmittance of the lens portion 31. The ferrule 30 can be made of, for example, PPS (polyphenylene sulfide), PEI (polyetherimide), PC (polycarbonate), PMMA (polymethyl methacrylate), PES (polyethersulfone), or COP (cyclic olefin polymer), etc.
[0049] A lens section 31 is disposed in front of the plurality of optical fibers 20 and faces the plurality of optical fibers 20 in the X direction. The lens section 31 is, for example, plate-shaped along the YZ plane. The lens section 31 includes a front end surface 31a located at the front end in the X direction, a rear end surface 31b located at the rear end in the X direction, and a plurality of lenses 31c disposed on the front end surface 31a. The front end surface 31a and the rear end surface 31b are, for example, planes parallel to the YZ plane. The rear end surface 31b faces the plurality of optical fibers 20 in the X direction.
[0050] Each lens 31c is a convex lens protruding forward from the front end face 31a. The lenses 31c are arranged in a row along the Y direction, corresponding to the positions of each optical fiber 20. Each lens 31c is positioned on the optical axis of each optical fiber 20 and is optically coupled to it. For example, when viewed from the X direction, the optical axis of each lens 31c is aligned with the optical axis of each optical fiber 20. Light emitted from each optical fiber 20 is converted into parallel light (i.e., collimated light) by each lens 31c before traveling to the optical connector 10 (see reference 10). Figure 10 (Injection). To suppress reflected light returning to the front end of the fiber 20, the optical axis of the fiber 20 may be offset from the optical axis of the lens 31c. Similarly, for the purpose of suppressing reflected light, the front end of the fiber 20 or the front end of the lens 31a may be tilted relative to the YZ plane, for example, by 8°.
[0051] The ferrule 30 has: a front end face 32 (top face) located at the front end in the X direction; a rear end face 33 located at the rear end in the X direction; and four outer faces 34, 35, 36, and 37 connecting the front end face 32 and the rear end face 33 in the X direction. The front end face 32 and the rear end face 33 are, for example, along the YZ plane. The front end face 32 is located at a position that protrudes slightly forward from the front end face 31a of the lens portion 31. The rear end face 33 includes an opening 33a for receiving a plurality of optical fibers 20 (see reference). Figure 2 The opening 33a is the portion of the rear end face 33 that opens in the X direction.
[0052] Outer surfaces 34 and 35 are opposite to each other in the Z-direction and extend along the XY plane. The side of outer surface 34 facing the Z-direction forms the upper surface of the ferrule 30. The other side of outer surface 35 facing the Z-direction forms the lower surface of the ferrule 30. Outer surface 34 is located opposite to the plurality of fiber slots 40 described later in the Z-direction. Two windows, 34a and 34b, are provided on outer surface 34, both opening in the Z-direction. Window 34a is configured to be closer to the front end face 32 in the X-direction than window 34b. Window 34a is, for example, located behind the lens portion 31. The width of window 34a in the Y-direction is the same as or wider than the overall width of the plurality of optical fibers 20 in the Y-direction. Window 34b is located rearward at a predetermined distance from window 34a. The width of window 34b in the Y-direction is, for example, narrower than the width of window 34a in the Y-direction. The number of windows with 34 openings on the outer side is not limited to two; it can also be one or more than three.
[0053] Outer side surface 36 and outer side surface 37 are arranged opposite each other in the Y direction, forming a pair of sides of the ferrule 30. Each of the outer side surface 36 and outer side surface 37 is provided with an adapter 50 for guiding the ferrule 30 backwards (see reference). Figure 10The V-grooves 36a and 37a (guide portions) are inserted. The V-grooves 36a and 37a are, for example, positioned symmetrically about the center of the ferrule 30 in the Y direction. The V-grooves 36a are recessed in the Y direction from the outer surface 36 toward the inner side of the ferrule 30 (i.e., the side from the outer surface 36 toward the outer surface 37), and open in the Y direction toward the outer side of the ferrule 30 (i.e., the side opposite to the outer surface 36 and outer surface 37). The V-grooves 36a are V-shaped in the YZ section, and the bottom of the V-grooves 36a has, for example, rounded corners. The V-grooves 36a extend linearly along the X direction on the outer surface 36. For example, the V-grooves 36a extend continuously along the X direction from the front end face 32 to the rear end face 33 on the outer surface 36. That is, the V-grooves 36a extend along the entire length of the ferrule 30 in the X direction.
[0054] V-groove 37a is recessed in the Y direction from the outer side 37 toward the inner side of the ferrule 30, and opens outward in the Y direction toward the outer side of the ferrule 30. V-groove 37a has, for example, the same shape as V-groove 36a. V-groove 37a extends in a straight line along the X direction on the outer side 37. V-groove 37a extends continuously along the X direction from the front end face 32 to the rear end face 33 on the outer side 37. That is, V-groove 37a extends along the entire length of the ferrule 30 in the X direction.
[0055] like Figure 2 As shown, the ferrule 30 has inside: a receiving hole 39 for receiving a plurality of optical fibers 20 received from the opening 33a of the rear end face 33; and a plurality of optical fiber slots 40 for supporting the plurality of optical fibers 20 received in the receiving hole 39. The receiving hole 39 extends from the opening 33a of the rear end face 33 along the X direction to the rear end face 31b of the lens portion 31. The receiving hole 39 communicates with the window portions 34a and 34b provided on the outer side face 34 in the Z direction. The plurality of optical fiber slots 40 extend from the center portion of the receiving hole 39 along the X direction to the front end portion of the receiving hole 39. The front ends of the plurality of optical fiber slots 40 are located opposite the window portion 34a in the Z direction. The rear ends of the plurality of optical fiber slots 40 are located behind the window portion 34b. The plurality of optical fiber slots 40 are arranged side by side along the Y direction in a manner corresponding to a plurality of lenses 31c respectively. That is, the plurality of lenses 31c are respectively disposed on the extension lines of the plurality of optical fiber slots 40. Therefore, multiple lenses 31c are respectively positioned opposite to multiple optical fibers 20 supported by multiple optical fiber slots 40 in the X direction.
[0056] like Figure 2As shown, adhesive A injected from the window portion 34a is provided on multiple fiber optic slots 40. Adhesive A is made of, for example, a light-transmitting material. Each optical fiber 20 is fixed to each fiber optic slot 40 by adhesive A. Furthermore, a cover portion B is provided inside the window portion 34a on each fiber optic slot 40. The cover portion B is a plate-shaped member along the XY plane and is configured to be separate from the ferrule 30. The cover portion B is made of, for example, a light-transmitting glass plate or resin. The cover portion B is placed on each optical fiber 20 supported by each fiber optic slot 40 and is configured to press each optical fiber 20 into each fiber optic slot 40. Thus, the position of each optical fiber 20 relative to each fiber optic slot 40 is fixed. The cover portion B is, for example, located in the region inside the window portion 34a, in the Z direction, on the straight portion 41b of the first fiber optic slot portion 41 described later (see reference). Figure 5 The area opposite to it contacts the straight section 41b. Figure 2 In the example shown, the cover B is configured to be recessed inside the window 34a, but alternatively, a portion of the cover B may extend outward from the window 34a along the Z direction. That is, a portion of the cover B may protrude upward from the window 34a. The adhesive A may enter either the gap between the cover B and each fiber optic slot 40, or it may enter the interior of each fiber optic slot 40 (i.e., the gap between each fiber 20 and each fiber optic slot 40).
[0057] Figure 3 This is a three-dimensional diagram representing the ferrule 30. Figure 4 This is a cross-sectional view of the insert 30. Figure 4 The XZ section of the insert 30 is shown. (See figure) Figure 4 As shown, the fiber optic slot 40 includes a first fiber optic slot 41 and a second fiber optic slot 42 sequentially from the lens portion 31 side in the X direction. The first fiber optic slot 41 is disposed behind the lens portion 31. The second fiber optic slot 42 is disposed further behind the first fiber optic slot 41. Therefore, the first fiber optic slot 41 is configured to be closer to the lens portion 31 in the X direction than the second fiber optic slot 42. In other words, the second fiber optic slot 42 is disposed on the opposite side of the lens portion 31 in the X direction relative to the first fiber optic slot 41.
[0058] The first fiber groove 41 and the second fiber groove 42 are, for example, V-grooves. That is, the first fiber groove 41 and the second fiber groove 42 are V-shaped openings that face upwards (i.e., in the Z direction from the outer side 35 towards the outer side 34) in the YZ cross section. The first fiber groove 41 is provided for high-precision positioning of the fiber 20 relative to the lens 31c. Therefore, the first fiber groove 41 is formed with high precision such that the optical axis of the fiber 20, which is supported by the first fiber groove 41 when viewed from the X direction, is aligned with or very close to the optical axis of the lens 31c. The fiber 20 supported by the first fiber groove 41 is in a state of high-precision core alignment relative to the lens 31c.
[0059] On the other hand, the second fiber optic slot 42 is provided for guiding the optical fiber 20 into the first fiber optic slot 41. The second fiber optic slot 42 determines the approximate position of the optical fiber 20 relative to the lens 31c to facilitate the guiding of the optical fiber 20, which is inserted into the ferrule 30 from the opening 33a, into the first fiber optic slot 41. That is, before the optical fiber 20 is precisely positioned in the first fiber optic slot 41, a rough positioning of the optical fiber 20 relative to the lens 31c is performed in the second fiber optic slot 42. Therefore, when the optical fiber 20 is supported by the second fiber optic slot 42, the allowable amount of offset of the optical axis of the optical fiber 20 relative to the optical axis of the lens 31c is ensured to be larger compared to the state when the optical fiber 20 is supported by the first fiber optic slot 41. Therefore, before reaching the first fiber optic slot 41, the optical fiber 20 supported by the second fiber optic slot 42 is in a state of rough positioning relative to the lens 31c.
[0060] Here, the configuration of the first optical fiber slot 41 and the second optical fiber slot 42 will be described in more detail. Figure 5 It is Figure 4 An enlarged cross-sectional view showing the vicinity of the first fiber groove 41 and the second fiber groove 42. Figure 6 This is another cross-sectional view showing the vicinity of the first fiber optic slot 41 and the second fiber optic slot 42. Figure 5 The XZ section of the insert 30 is shown. Figure 6 The XY cross section of the insert 30 is shown.
[0061] like Figure 5 As shown, the first fiber optic groove 41 is formed in the Z direction at a position opposite to the window 34a. When viewed from the Z direction, the first fiber optic groove 41 is recessed inside the window 34a and does not exist outside the window 34a. The total length L1 of the first fiber optic groove 41 in the X direction is shorter than the width of the window 34a in the X direction, and shorter than the cover portion B (refer to) disposed inside the window 34a. Figure 2 The width in the X direction is longer. The total width of all the first fiber slots 41 in the Y direction is smaller than the width of the window 34a in the Y direction.
[0062] The total length L1 of the first fiber optic slot 41 is, for example, set to be more than 3 times and less than 40 times the diameter of the fiber optic cable 20. Here, the diameter of the fiber optic cable 20 refers to 0.125 mm, which is the diameter of a common optical fiber. Thus, by making the total length L1 of the first fiber optic slot 41 greater than the diameter of the fiber optic cable 20, the orientation of the fiber optic cable 20, supported by the first fiber optic slot 41, can be easily stabilized in the X-direction. The total length L1 of the first fiber optic slot 41 refers to the length of the entire first fiber optic slot 41 in the X-direction, including the tapered portion 41a, the straight portion 41b, and the tapered portion 41c described later.
[0063] On the other hand, the second fiber optic slot 42 is not formed opposite the window 34a in the Z direction. The second fiber optic slot 42 is disposed rearward in the X direction, spaced apart from the window 34a and the first fiber optic slot 41 by a predetermined interval. Figure 5 and Figure 6 As shown, the second fiber optic slot 42 is positioned in the X direction at a distance R from the first fiber optic slot 41 rearward. The distance R is, for example, set in the range of 0.01 mm or more and 3 mm or less. The second fiber optic slot 42 is formed in the Z direction opposite to the window 34b, which is located rearward from the window 34a.
[0064] The window portion 34b is, for example, positioned opposite the center portion of the second fiber optic slot portion 42 in the X direction along the Z direction. The total length L2 of the second fiber optic slot portion 42 in the X direction is longer than the width of the window portion 34b in the X direction. The total length L2 of the second fiber optic slot portion 42 in the X direction is set to be greater than or equal to the total length L1 of the first fiber optic slot portion 41 in the X direction. That is, the total length L2 of the second fiber optic slot portion 42 is the same as or longer than the total length L1 of the first fiber optic slot portion 41. The total length L2 of the second fiber optic slot portion 42 refers to the length of the entire second fiber optic slot portion 42 in the X direction, including the straight portion 42a and the tapered portion 42b described later.
[0065] like Figure 5 and Figure 6 As shown, the first fiber optic groove 41, starting from the lens portion 31 side in the X direction, sequentially includes a tapered portion 41a (second tapered portion), a straight portion 41b, and a tapered portion 41c (first tapered portion). The straight portion 41b is a portion extending in a straight line along the X direction behind the lens portion 31. At each position along the X direction in the straight portion 41b, the YZ cross-sectional shape of the first fiber optic groove 41 (i.e., the opening shape of the V-groove) is constant. The straight portion 41b is configured to precisely position the fiber optic 20 relative to the lens 31c.
[0066] Figure 7A This is a cross-sectional view showing the straight section 41b of the first fiber optic groove 41. Figure 7A The diagram shows an imaginary circle C1 internally tangent to a pair of inner surfaces S1, S1 that constitute the straight section 41b. The center C0 of the imaginary circle C1, for example, when viewed from the X direction, is aligned with lens 31c (see reference). Figure 5 and Figure 6 The optical axis of the imaginary circle C1 is aligned with that of the optical fiber 20 (refer to...). Figure 1 and Figure 2 The diameters are the same. When viewed from the X direction, the optical axis of the fiber 20, which is supported by the straight portion 41b, coincides with the optical axis of the lens 31c. Therefore, in Figure 7AIn the diagram, the double-dotted line representing the imaginary circle C1 illustrates the shape of the optical fiber 20, which is supported by the straight section 41b. When viewed from the X direction, the center C0 of the imaginary circle C1 does not need to be strictly aligned with the optical axis of the lens 31c, but can be slightly offset relative to the optical axis of the lens 31c.
[0067] Thus, the shape of the straight section 41b is designed such that the optical axis of the optical fiber 20 supported by the straight section 41b is aligned with or very close to the optical axis of the lens 31c. Therefore, the optical fiber 20 is positioned with high precision at the straight section 41b. Consequently, with the optical fiber 20 supported by the straight section 41b, the optical fiber 20 is precisely centered relative to the lens 31c. At each position along the X direction of the straight section 41b, the YZ cross-sectional shape of the first optical fiber groove 41 is constant, therefore, at each position along the X direction, the diameter d1 of the imaginary circle C1 is also constant. In this case, at each position along the X direction of the straight section 41b, the opening width W1 and depth D1 of the first optical fiber groove 41, which is a V-groove, are also constant. The opening width W1 of the first optical fiber groove 41 is the maximum width of the opening portion of the first optical fiber groove 41 in the Y direction. More specifically, the opening width W1 of the first optical fiber groove 41 is the width of the opening portion of the first optical fiber groove 41 in the Y direction within the forming surface for forming the first optical fiber groove 41. The depth D1 of the first optical fiber groove 41 is the distance in the Z direction from the forming surface of the first optical fiber groove 41 to the bottom of the first optical fiber groove 41.
[0068] like Figure 5 and Figure 6 As shown, the tapered portion 41a of the first fiber optic slot 41 is located in front of the straight portion 41b. Specifically, the tapered portion 41a extends in the X direction from the front end of the straight portion 41b to a position near the front of the lens portion 31 (i.e., a position slightly separated rearward from the rear end face 31b of the lens portion 31). Therefore, the tapered portion 41a is positioned between the lens portion 31 and the straight portion 41b in the X direction. At various positions along the X direction of the tapered portion 41a, the YZ cross-sectional shape of the first fiber optic slot 41 changes. The tapered portion 41a is positioned such that the diameter d1 of the imaginary circle C1 (refer to...) increases with distance from the straight portion 41b in the X direction. Figure 7A The larger the inclination, the greater the inclination. The inclination of the tapered portion 41a is in... Figure 5 The XZ section shown can be either a straight line or a curve.
[0069] As a result, the diameter d1 of the imaginary circle C1 at the rear end of the tapered portion 41a is the same as the diameter d1 of the imaginary circle C1 of the straight portion 41b, while the diameter d1 of the imaginary circle C1 at the front end of the tapered portion 41a is larger than the diameter d1 of the imaginary circle C1 of the straight portion 41b. For example, at various positions along the X direction in the tapered portion 41a, the opening width W1 of the first fiber optic groove 41 is constant; on the other hand, the further away from the straight portion 41b in the X direction, the deeper the depth D1 of the first fiber optic groove 41 becomes (see reference). Figure 7A By having such a tapered portion 41a, it is possible to ensure that adhesive A (see reference) is permissible in front of the straight portion 41b. Figure 2 ) space.
[0070] like Figure 5 and Figure 6 The tapered portion 41c of the first fiber optic slot 41 extends further rearward from the rear end of the straight portion 41b. The tapered portion 41c is positioned in the X direction between the straight portion 41b and the second fiber optic slot 42. At various positions along the X direction of the tapered portion 41c, the YZ cross-sectional shape of the first fiber optic slot 41 changes. The tapered portion 41c is positioned such that the diameter d1 of the imaginary circle C1 (refer to...) increases with distance from the straight portion 41b in the X direction. Figure 7A The larger the inclination, the greater the inclination. The inclination of the tapered portion 41c is in... Figure 5 The XZ section shown can be either a straight line or a curve.
[0071] As a result, the diameter d1 of the imaginary circle C1 at the front end of the tapered portion 41c is the same as the diameter d1 of the imaginary circle C1 of the straight portion 41b, while the diameter d1 of the imaginary circle C1 at the rear end of the tapered portion 41c is larger than the diameter d1 of the imaginary circle C1 of the straight portion 41b. Therefore, among the diameters d1 of the imaginary circles C1 at various positions along the X direction in the first fiber optic groove portion 41, the diameter d1 of the imaginary circle C1 at the straight portion 41b is the smallest.
[0072] For example, at various positions along the X direction in the tapered portion 41c, the opening width W1 of the first fiber optic groove 41 is constant; on the other hand, the depth D1 of the first fiber optic groove 41 increases the further away from the straight portion 41b in the X direction (see reference). Figure 7A With the presence of such a tapered portion 41c, the optical fiber 20 from the second optical fiber slot 42 can be introduced into the straight portion 41b of the first optical fiber slot 41. Therefore, the tapered portion 41c functions as a guide portion for guiding the optical fiber 20 from the second optical fiber slot 42 to the straight portion 41b.
[0073] like Figure 5 and Figure 6As shown, the second fiber optic slot 42 includes a straight portion 42a and a tapered portion 42b sequentially from the side of the first fiber optic slot 41 in the X direction. The straight portion 42a is a portion that extends in a straight line along the X direction behind the first fiber optic slot 41. The straight portion 42a extends rearward from a position a distance R away from the rear end of the tapered portion 41c relative to the first fiber optic slot 41. The tapered portion 42b extends further rearward from the rear end of the straight portion 42a. Therefore, the tapered portion 42b is disposed on the side opposite to the first fiber optic slot 41 in the X direction relative to the straight portion 42a. A window portion 34b is disposed in the Z direction opposite to the connection portion of the straight portion 42a and the tapered portion 42b.
[0074] At each position along the X direction in the straight section 42a, the YZ cross-sectional shape (i.e., the opening shape of the V-groove) of the second fiber groove section 42 remains constant. The straight section 42a is formed to determine the approximate position of the fiber 20 relative to the lens 31c. Therefore, the fiber 20 supported by the straight section 42a is in a state of being roughly positioned relative to the lens 31c.
[0075] Figure 7B This is a cross-sectional view showing the straight section 42a of the second fiber optic groove 42. Figure 7B In, with Figure 7A The imaginary circle C1 shown together with the imaginary circle C2 is internally tangent to the pair of inner surfaces S2, S2 constituting the straight section 42a. The imaginary circle C2 is formed as a concentric circle with a diameter d2 larger than that of the imaginary circle C1, centered on the center C0 (i.e., the optical axis of the lens 31c). Therefore, the allowable displacement of the optical fiber 20 supported by the straight section 42a of the second optical fiber slot 42 relative to the lens 31c is ensured to be greater than the allowable displacement of the optical fiber 20 supported by the straight section 41b of the first optical fiber slot 41 relative to the lens 31c. Thus, the shape of the straight section 42a is formed to coarsely position the optical fiber 20 relative to the lens 31c.
[0076] At each position along the X direction in the straight section 42a, the YZ cross-sectional shape of the second fiber optic groove 42 is constant; therefore, at each position along the X direction, the diameter d2 of the imaginary circle C2 is also constant. In this case, at each position along the X direction in the straight section 42a, the opening width W2 and depth D2 of the second fiber optic groove 42, which is a V-groove, are also constant. The opening width W2 of the second fiber optic groove 42 is the maximum width of the opening portion of the second fiber optic groove 42 in the Y direction. More specifically, the opening width W2 of the second fiber optic groove 42 is the width of the opening portion of the second fiber optic groove 42 in the Y direction within the forming surface for which the second fiber optic groove 42 is formed. The depth D2 of the second fiber optic groove 42 is the distance in the Z direction from the forming surface of the second fiber optic groove 42 to the bottom of the second fiber optic groove 42. The diameter d2 of the imaginary circle C2 is larger than the diameter d1 of the imaginary circle C1. Therefore, the opening width W2 of the straight section 42a is larger than the opening width W1 of the straight section 41b, and the depth D2 of the straight section 42a is deeper than the depth D1 of the straight section 41b.
[0077] Figure 8 This is a cross-sectional view showing the tapered portion 42b of the second fiber optic groove 42. Figure 8 In, with Figure 7B The imaginary circle C2 shown together with the imaginary circle C3 is internally tangent to the pair of inner surfaces S3, S3 constituting the conical portion 42b. The imaginary circle C3 forms a concentric circle with a diameter d3 larger than that of the imaginary circle C2, centered on the center C0 of the imaginary circle C1 (i.e., the optical axis of the lens 31c). At various positions along the X direction in the conical portion 42b, the YZ cross-sectional shape of the second fiber groove portion 42 changes. The conical portion 42b is tilted such that the diameter d3 of the imaginary circle C3 increases the further away from the straight portion 42a in the X direction. The tilt of the conical portion 42b... Figure 5 The XZ section shown can be either a straight line or a curve.
[0078] As a result, the diameter d3 of the imaginary circle C3 at the rear end of the tapered portion 42b is larger than the diameter d2 of the imaginary circle C2 of the straight portion 42a. The diameter d3 of the imaginary circle C3 at the front end of the tapered portion 42b is the same as the diameter d2 of the imaginary circle C2 of the straight portion 42a. Therefore, among the imaginary circles C2 and C3 at various positions along the X direction in the second fiber optic slot 42, the diameter d2 of the imaginary circle C2 at the straight portion 42a is the smallest. The diameter d1 of the imaginary circle C1 at the straight portion 41b of the first fiber optic slot 41 is smaller than the diameter d2 of the imaginary circle C2 at the straight portion 42a of the second fiber optic slot 42.
[0079] For example, at various positions along the X direction in the tapered portion 42b, the opening width W2 of the second fiber optic groove 42 is constant; on the other hand, the depth D3 of the second fiber optic groove 42 increases the further away from the straight portion 42a in the X direction (see reference). Figure 8 With the presence of such a tapered portion 42b, the optical fiber 20 inserted from the opening 33a can be guided to the straight portion 42a. Therefore, the tapered portion 42b functions as a guide portion to guide the optical fiber 20 to the straight portion 42a.
[0080] When manufacturing the optical connector 10 described above, firstly, a plurality of optical fibers 20 are inserted into the receiving holes 39 inside the ferrule 30 through the opening 33a of the rear end face 33 of the ferrule 30. Then, each optical fiber 20 inserted into the receiving hole 39 is positioned in each optical fiber slot 40. At this time, the optical fiber 20 is guided to the straight section 42a through the tapered portion 42b of the second optical fiber slot 42. The optical fiber 20 is corrected to a state along the X direction in the straight section 42a and its approximate position relative to the lens 31c is determined. In this way, the optical fiber 20 is roughly positioned in the second optical fiber slot 42.
[0081] Subsequently, the optical fiber 20 is introduced from the straight portion 42a of the second optical fiber groove 42 to the tapered portion 41c of the first optical fiber groove 41. Then, the optical fiber 20 is guided from the tapered portion 41c to the straight portion 41b. The optical fiber 20 is corrected in the straight portion 41b to be aligned along the X direction and its precise position relative to the lens 31c is determined. In this way, high-precision positioning of the optical fiber 20 is achieved in the first optical fiber groove 41. That is, when viewed from the X direction, the optical axis of the optical fiber 20, supported by the straight portion 41b, is aligned with or very close to the optical axis of the lens 31c. Then, the optical fiber 20 is transferred from the straight portion 41b to the tapered portion 41a, abutting against the rear end face 31b of the lens portion 31. The optical fiber 20 can also be separated from the rear end face 31b of the lens portion 31. That is, the optical fiber 20 can also be configured to be spaced apart from the rear end face 31b of the lens portion 31 by a predetermined interval.
[0082] Then, adhesive A is injected into the interior of the insert 30 from the window portion 34a, and the cover portion B is disposed inside the window portion 34a (see reference). Figure 2 At this time, the adhesive A injected into the ferrule 30 also spreads throughout the gap between the cover B and each optical fiber 20. With the cover B pressing each optical fiber 20 into its respective fiber slot 40, the adhesive A cures, thereby fixing each optical fiber 20 to its respective fiber slot 40. Thus, the position of each optical fiber 20 relative to the ferrule 30 is fixed.
[0083] The configuration of the first fiber optic slot 41 and the second fiber optic slot 42 is not limited to the configuration described above and can be appropriately modified. For example, the second fiber optic slot 42 may also be a slot with a different shape than the first fiber optic slot 41. That is, the second fiber optic slot 42 is not limited to a V-shaped slot in the YZ cross section, but may also be a slot with other shapes. Figure 9A , Figure 9B as well as Figure 9CThis is a cross-sectional view showing a modified example of the shape of the second fiber groove 42.
[0084] like Figure 9A As shown, the second fiber groove 42A can also be a semi-circular groove in the YZ cross section. For example... Figure 9B As shown, the second fiber slot 42B can also be a rectangular slot in the YZ cross section. For example... Figure 9C As shown, the second fiber optic slot 42C can also be a U-shaped slot in the YZ cross section. Regarding the first fiber optic slot 41, it does not necessarily need to be a V-shaped slot; it can also be a slot of other shapes. The second fiber optic slot 42 can be connected to the first fiber optic slot 41 in the X direction without being separated from it, or it can be directly connected to the first fiber optic slot 41 in the X direction.
[0085] The second fiber optic slot 42 may exclude the tapered portion 42b, or it may only include the straight portion 42a. The first fiber optic slot 41 may also exclude the tapered portions 41a and 41c, or it may only include the straight portion 41b. The total length L2 of the second fiber optic slot 42 may also be shorter than the total length L1 of the first fiber optic slot 41.
[0086] Next, refer to Figure 10 , Figure 11 as well as Figure 12 The optical connection structure 1 having the optical connector 10 described above will be explained. Figure 10 This is a three-dimensional diagram representing optical connection structure 1. Figure 11 This is a top view showing the optical connection structure 1. Figure 12 This is a rear view showing the optical connection structure 1. Figure 10 , Figure 11 as well as Figure 12 The image shows an optical connector 10 with multiple optical fibers 20 omitted (i.e., only the ferrule 30 is shown). Figure 10 and Figure 11 The adapter 50 of the optical connection structure 1 is shown in the cross-section when cut by the XY plane.
[0087] like Figure 10 and Figure 11 As shown, the optical connection structure 1 includes: a pair of optical connectors 10, 10 configured to face each other in the X direction; and an adapter 50 for inserting the pair of optical connectors 10, 10. The pair of optical connectors 10, 10 are configured in an upside-down position. The pair of optical connectors 10, 10 are fitted into the adapter 50 with their respective ferrules 30, 30 facing each other inside the adapter 50. Inside the adapter 50, the pair of ferrules 30, 30 can either abut against each other or be configured to be spaced apart by a predetermined distance.
[0088] The adapter 50 may be made of a flexible material such as PEI (polyetherimide), PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), PC (polycarbonate), PMMA (polymethyl methacrylate), PES (polyethersulfone), or PA (polyamide). From the viewpoint of reducing the difference between the coefficient of linear expansion of the adapter 50 material and the ferrule 30 material, the same material as the ferrule 30 may be used as the material of the adapter 50.
[0089] The adapter 50 is cylindrical, capable of accommodating a pair of connectors 30, 30, and extends along the X direction. For example, the total length of the adapter 50 in the X direction is longer than the combined total length of the pair of connectors 30, 30 in the X direction when they are connected to each other. Figure 12 As shown, the adapter 50 is rectangular in shape when viewed from the X direction. The adapter 50 has an insertion hole 51 that forms the interior of the rectangular tube. The insertion hole 51 is a through hole that passes through the adapter 50 in the X direction. The insertion hole 51 is rectangular in shape when viewed from the X direction and is formed by four inner surfaces 52, 53, 54 and 55.
[0090] Inner surface 52 faces outer surface 34 of insert 30 in the Z direction, and inner surface 53 faces outer surface 35 of insert 30 in the Z direction. Inner surface 54 faces outer surface 36 of insert 30 in the Y direction, and inner surface 55 faces outer surface 37 of insert 30 in the Y direction. V-protrusions 54a and 55a are provided on inner surfaces 54 and 55 respectively for guiding V-grooves 36a and 37a of insert 30. V-protrusions 54a and 55a are, for example, arranged symmetrically about the center of insertion hole 51 in the Y direction. V-protrusions 54a and 55a are V-shaped protrusions in the YZ cross section. V-protrusion 54a protrudes from inner surface 54 toward outer surface 36 of insert 30 and abuts against V-groove 36a of outer surface 36. V-protrusion 54a extends continuously along the X direction on inner surface 54, for example. V-shaped protrusion 55a protrudes from the inner surface 55 toward the outer surface 37 of the insert 30 and abuts against the V-groove 37a of the outer surface 37. V-shaped protrusion 55a may be provided continuously along the X direction on the inner surface 55, for example.
[0091] V-protrusion 54a has a shape corresponding to V-groove 36a. The opening angle of V-protrusion 54a (i.e., the angle between the outer surfaces constituting V-protrusion 54a) is set smaller than the opening angle of V-groove 36a of ferrule 30 (i.e., the angle between the pair of inner surfaces constituting V-groove 36a). The top of V-protrusion 54a has, for example, a rounded corner. V-protrusion 55a has a shape corresponding to V-groove 37a. V-protrusion 55a has, for example, the same shape as V-protrusion 54a. The separation distance between V-protrusion 54a and V-protrusion 55a in the Y direction is set slightly smaller than the width between V-groove 36a and V-groove 37a of ferrule 30 in the Y direction. The separation distance between V-protrusion 54a and V-protrusion 55a in the Y direction can be defined as the distance between the top of V-protrusion 54a and the top of V-protrusion 55a in the Y direction when ferrule 30 is not inserted into adapter 50. The width between V-groove 36a and V-groove 37a in the Y direction can be defined as the distance between the bottom of V-groove 36a and the bottom of V-groove 37a in the Y direction.
[0092] The adapter 50 has a hollow portion 61 located on the outer side of the insertion hole 51 in the Y direction. The hollow portion 61 is located on the outer side of the insertion hole 51 in the Y direction, separated from the wall portion 54W constituting the inner surface 54. That is, the hollow portion 61 is adjacent to the insertion hole 51 in the Y direction, separated from the wall portion 54W. The hollow portion 61 extends linearly in the X direction, for example, at a position parallel to the insertion hole 51 in the Y direction. The wall portion 54W extends in the Z direction between the hollow portion 61 and the insertion hole 51, separating them. The thickness of the wall portion 54W (i.e., the width of the wall portion 54W in the Y direction) is, for example, set to be constant. The thickness of the wall portion 54W is sufficiently thin to allow for the elastic deformation of the V-protrusion 54a. Similarly, the thickness of the wall portion constituting the inner surface 55 is also sufficiently thin to allow for the elastic deformation of the V-protrusion 55a. The presence of such a hollow portion 61 makes the V-protrusion 54a more susceptible to elastic deformation. No hollow portion is provided on the outer side of the insertion hole 51 in the Y direction (i.e., on the side in the Y direction opposite to the inner surface 55 and the insertion hole 51).
[0093] In the optical connection structure 1 described above, when the ferrule 30 is inserted into the adapter 50, the V-grooves 36a and 37a of the ferrule 30 are respectively engaged with the V-protrusions 54a and 55a of the adapter 50. At this time, the V-protrusion 54a enters and abuts within the V-grooves 36a of the ferrule 30, and the V-protrusion 55a enters and abuts within the V-grooves 37a of the ferrule 30. Here, as described above, the separation distance between the V-protrusions 54a and 55a of the adapter 50 is set to be smaller than the width between the V-grooves 36a and 37a of the ferrule 30. Therefore, the V-protrusions 54a and 55a of the adapter 50 are subjected to a reaction force from the V-grooves 36a and 37a of the ferrule 30, and undergo elastic deformation in the Y direction towards the outside of the ferrule 30. Furthermore, the force exerted by the V-protrusions 54a and 55a of the adapter 50 to return to their original positions is applied to the plug 30, and the plug 30 is fixed by being clamped by the V-protrusions 54a and 55a of the adapter 50.
[0094] As a result, the V-protrusions 54a and 55a of the adapter 50 contact the V-grooves 36a and 37a of the ferrule 30, respectively. Therefore, the gaps in the Y direction between the V-protrusions 54a and 36a, and between the V-protrusions 55a and 37a, are zero. Thus, the position of the ferrule 30 relative to the adapter 50 in the YZ plane is defined, and the position of the rotation direction of the ferrule 30 relative to the adapter 50 in the YZ plane is defined. Then, a spring (not shown) mounted at the rear of the ferrule 30 applies force to the ferrule 30 in the X direction towards the ferrule 30 connected to it, thereby defining the position of the ferrule 30 relative to the adapter 50 in the X direction (see reference). Figure 10 and Figure 11 In this way, the position of the ferrule 30 relative to the adapter 50 is defined.
[0095] In the presence of gaps in the Z-direction between the V-protrusion 54a and the V-groove 36a (i.e., the difference between the width of the V-protrusion 54a and the width of the V-groove 36a in the Z-direction) and between the V-protrusion 55a and the V-groove 37a (i.e., the difference between the width of the V-protrusion 55a and the width of the V-groove 37a in the Z-direction), the size of these gaps may cause positional or angular offsets between the ferrule 30 and the ferrule 30 connected to it. Therefore, ideally, these gaps should be set as small as possible.
[0096] In this embodiment, V-protrusions 54a and 55a are part of the adapter 50 made of elastic material, and therefore both V-protrusions 54a and 55a are configured to be elastically deformable. However, for example, only V-protrusion 54a may be configured to be elastically deformable. In this case, V-protrusion 55a may not be configured to be elastically deformable. In this embodiment, a hollow portion 61 is provided on the outer side of the wall portion 54W where V-protrusions 54a are provided (i.e., on the side opposite to the insertion hole 51 relative to the wall portion 54W). Therefore, by using the portion near the wall portion 54W made of elastic material, only V-protrusion 54a can be configured to be elastically deformable. In this case, when the insert 30 is inserted into the adapter 50, the V-groove 37a of the insert 30 is positioned against the non-elastically deformable V-protrusion 55a in an abutting manner, and the V-groove 36a of the insert 30 abuts against the elastically deformable V-protrusion 54a. At this time, the V-protrusion 54a undergoes elastic deformation due to the reaction force from the V-groove 36a, and the force that the V-protrusion 54a exerts to return to its original position is applied to the insert 30. As a result, the insert 30 is fixed by being clamped by the V-protrusions 54a and 55a, and the position of the insert 30 relative to the adapter 50 is defined.
[0097] In this embodiment, V-grooves 36a and 37a are respectively provided on the outer surface 36 and outer surface 37 of the ferrule 30. However, grooves with other shapes can also be provided instead of V-grooves 36a and 37a. For example, U-grooves that are U-shaped in the YZ cross section, semi-circular grooves that are semi-circular in the YZ cross section, or rectangular grooves that are rectangular in the YZ cross section can be provided on the outer surface 36 and outer surface 37 of the ferrule 30. Correspondingly, elliptical protrusions that are elliptical in the YZ cross section, semi-circular protrusions that are semi-circular in the YZ cross section, or rectangular protrusions that are rectangular in the YZ cross section can be provided on the inner surface 54 and inner surface 55 of the adapter 50 instead of V-protrusions 54a and V-protrusions 55a. Alternatively, protrusions can be provided on the outer surface 36 and outer surface 37 of the ferrule 30, and grooves can be provided on the inner surface 54 and inner surface 55 of the adapter 50. Thus, if the position of the ferrule 30 relative to the adapter 50 can be specified when the ferrule 30 is fitted into the adapter 50, the combination of slots and protrusions in the ferrule 30 and the adapter 50 can be appropriately changed.
[0098] The effects obtained by the ferrule 30 and optical connector 10 of the present embodiment described above will be explained. In this embodiment, when the optical fiber 20 is inserted into the interior of the ferrule 30 through the opening 33a, the optical fiber 20 is guided into the first optical fiber groove 41 through the second optical fiber groove 42, and the optical fiber 20 is positioned relative to the lens 31c in the first optical fiber groove 41. Thus, by having the second optical fiber groove 42 that guides the optical fiber 20 into the first optical fiber groove 41, the possibility of the optical fiber 20 colliding with the wall between the optical fiber 20 and the optical fiber groove 40 when the optical fiber 20 is inserted into the interior of the ferrule 30 can be reduced, and the optical fiber 20 can be reliably positioned in the first optical fiber groove 41. Therefore, according to this embodiment, the workability of assembling the optical fiber 20 into the ferrule 30 can be improved.
[0099] In this embodiment, in the YZ cross section, the first fiber groove 41 and the second fiber groove 42 are both V-shaped. This allows for more precise positioning of the fiber 20 relative to the lens 31c.
[0100] In this embodiment, in the YZ cross section, the opening width W2 of the second fiber optic slot 42 is larger than the opening width W1 of the first fiber optic slot 41. Therefore, the allowable displacement of the fiber optic cable 20, supported by the second fiber optic slot 42, relative to the lens 31c can be ensured to be larger than the allowable displacement of the fiber optic cable 20, supported by the first fiber optic slot 41, relative to the lens 31c. As a result, when the fiber optic cable 20 is inserted into the ferrule 30, after determining the approximate position of the fiber optic cable 20 relative to the lens 31c in the second fiber optic slot 42, the position of the fiber optic cable 20 relative to the lens 31c can be determined with high precision in the first fiber optic slot 41. Therefore, according to the above configuration, the second fiber optic slot 42 for guiding the fiber optic cable 20 into the first fiber optic slot 41 can be appropriately implemented.
[0101] In this embodiment, in the YZ section, the diameter d2 of the imaginary circle C2 centered on the optical axis of lens 31c and internally tangent to the second fiber optic slot 42 is larger than the diameter d1 of the imaginary circle C1 centered on the optical axis of lens 31c and internally tangent to the first fiber optic slot 41. Therefore, the allowable displacement of the optical fiber 20 relative to lens 31c when supported by the second fiber optic slot 42 can be ensured to be larger than the allowable displacement of the optical fiber 20 relative to lens 31c when supported by the first fiber optic slot 41. As a result, when the optical fiber 20 is inserted into the ferrule 30, after determining the approximate position of the optical fiber 20 relative to lens 31c in the second fiber optic slot 42, the position of the optical fiber 20 relative to lens 31c can be determined with high precision in the first fiber optic slot 41. Therefore, according to the above configuration, the second fiber optic slot 42 for guiding the optical fiber 20 into the first fiber optic slot 41 can be appropriately realized.
[0102] In this embodiment, the second fiber optic slot 42 includes: a straight portion 42a, wherein the diameter d2 of the imaginary circle C2 is constant at each position along the X direction; and a tapered portion 42b, which is inclined such that the diameter d3 of the imaginary circle C3 increases as it moves away from the straight portion 42a. By including the tapered portion 42b, the optical fiber 20 inserted into the ferrule 30 from the opening 33a can be reliably introduced into the straight portion 42a. Furthermore, by including the straight portion 42a, the orientation of the optical fiber 20 can be stabilized along the X direction, allowing the optical fiber 20 to be smoothly guided into the first fiber optic slot 41 while maintaining a stable orientation. Therefore, according to the above configuration, the optical fiber 20 can be reliably and smoothly guided into the first fiber optic slot 41.
[0103] In this embodiment, the total length L2 of the second fiber optic slot 42 is greater than or equal to the total length L1 of the first fiber optic slot 41. Therefore, the orientation of the fiber 20 can be stabilized more reliably in the second fiber optic slot 42.
[0104] In this embodiment, the second fiber optic slot 42 is configured to be spaced apart from the first fiber optic slot 41 by a predetermined interval. In this configuration, by forming the first fiber optic slot 41 independently of the second fiber optic slot 42, the first fiber optic slot 41 can be manufactured with high precision. Therefore, a suitable first fiber optic slot 41 for positioning the fiber optic cable 20 relative to the lens 31c can be obtained.
[0105] In this embodiment, when viewed from the Z direction, the first fiber groove 41 is recessed inside the window 34a. Therefore, the window 34a can be used not only as an injection window for injecting adhesive A into the ferrule 30, but also for the arrangement operation when introducing the optical fiber 20 into the first fiber groove 41. This further improves the workability when assembling the optical fiber 20.
[0106] In this embodiment, V-grooves 36a and 37a are respectively provided on the outer surface 36 and outer surface 37 to guide insertion into the adapter 50 along the X direction. Therefore, the position of the ferrule 30 relative to the adapter 50 can be determined using the V-grooves 36a and 37a. That is, the ferrule 30 can be positioned relative to the adapter 50 without using expensive guide pins.
[0107] In this embodiment, the optical fiber 20 is fixed to the first optical fiber groove 41 by adhesive A. Therefore, by fixing the position of the optical fiber 20 relative to the lens 31c by adhesive A, the positioning of the optical fiber 20 relative to the lens 31c can be performed more reliably.
[0108] In this embodiment, a cover portion B is provided inside the window portion 34a, which is disposed on the first fiber optic groove portion 41 with the optical fiber 20 in between. By pressing the optical fiber 20 into the first fiber optic groove portion 41 through the cover portion B, the positioning of the optical fiber 20 relative to the lens 31c can be further reliably achieved.
[0109] This disclosure is not limited to the embodiments described above, and appropriate modifications may be made without departing from the spirit of the claims.
[0110] Figure 13 This is a rear view showing a modified example of the aforementioned optical connection structure 1. Figure 13 The adapter 50A is shown in the cross-section when cut with the YZ plane. Figure 13 In the optical connection structure 1A shown, the adapter 50A is made of a non-elastic material. Examples of materials used for the adapter 50A include PPS (polyphenylene sulfide). The adapter 50A does not have the aforementioned hollow portion 61. In this case, even without using a particularly rigid material as the material for the adapter 50A, elastic deformation of the adapter 50A is not easily caused.
[0111] like Figure 13 As shown, semi-circular protrusions 54b and 55b are respectively provided on the inner surfaces 54 and 55 of the adapter 50A to replace the V-protrusions 54a and 55a. The semi-circular protrusions 54b and 55b are semi-circular protrusions in the YZ cross-section. Each of the semi-circular protrusions 54b and 55b abuts against the V-grooves 36a and 37a of the ferrule 30. The separation distance between the semi-circular protrusions 54b and 55b in the Y direction is slightly greater than the width of the V-grooves 36a and 37a of the ferrule 30 in the Y direction. The separation distance between the semi-circular protrusions 54b and 55b can be defined as the distance in the Y direction between the tops of the semi-circular protrusions 54b and 55b when the ferrule 30 is not inserted into the adapter 50A. Tiny gaps are generated in the Y direction between the semi-circular protrusion 54b and the V-groove 36a, and in the Y direction between the semi-circular protrusion 55b and the V-groove 37a.
[0112] Figure 14 This is a side view showing the optical connection structure 1A. Figure 14 The adapter 50A is shown in the cross-section when cut with the XZ plane. Figure 14 As shown, the two ends of the semi-circular protrusion 54b in the X direction are formed to taper at the tips as they move further apart in the X direction. When the insert 30 is inserted and fitted into the adapter 50A, the insert 30 moves along the X direction from one end of the adapter 50A to the other end within the adapter 50A. At this time, the semi-circular protrusion 54b enters and abuts against the V-groove 36a of the insert 30 (see reference). Figure 13 Inside, and a semi-circular protrusion 55b (refer to) Figure 13The plug 30 enters and abuts within the V-groove 37a of the plug 30. Thus, the plug 30 is held by the semi-circular protrusions 54b and 55b of the adapter 50A, and the position of the plug 30 relative to the adapter 50A is defined.
[0113] Therefore, in the optical connection structure 1A of this modified example, it also achieves the same effect as the optical connection structure 1 of the above-described embodiment. If, as in this modified example, the adapter 50A is made of a material that does not undergo elastic deformation, and assuming a configuration where V-grooves 36a and 37a are respectively fitted into V-protrusions 54a and 55a as described in the above-described embodiment, gaps are easily generated in the Y direction between V-grooves 36a and V-protrusions 54a, and between V-grooves 37a and V-protrusions 55a, due to manufacturing tolerances, etc. In this case, the position of the ferrule 30 relative to the adapter 50A is estimated to shift significantly depending on the contact positions of V-grooves 36a and V-protrusions 54a, and V-grooves 37a and V-protrusions 55a. In contrast, by employing a configuration where V-grooves 36a and 37a are respectively fitted into semi-circular protrusions 54b and 55b, such positional shift of the ferrule 30 relative to the adapter 50A can be suppressed.
[0114] The ferrule and optical connector disclosed herein are not limited to the embodiments and modifications described above, and various other modifications are possible. For example, in the embodiments and modifications described above, the configuration of the ferrule can be appropriately changed. For example, in the embodiments described above, the ferrule is shown to be integral with the lens portion, but the ferrule may also be configured to be separate from the lens portion. In this case, the ferrule may also be made of a material other than a light-transmitting resin.
[0115] Explanation of reference numerals in the attached figures:
[0116] 1. 1A: Optical connection structure;
[0117] 10: Optical connector;
[0118] 20: Optical fiber;
[0119] 30: ferrule;
[0120] 31: Lens section;
[0121] 31a: Front face;
[0122] 31b: Back end face;
[0123] 31c: Lens;
[0124] 32: Front face (top face);
[0125] 33: Back end face;
[0126] 33a: Opening;
[0127] 34: Outer side (upper surface);
[0128] 35: Outer side surface;
[0129] 36, 37: Outer side (side);
[0130] 34a: Window section;
[0131] 34b: Window section;
[0132] 36a, 37a: V-groove (guide section);
[0133] 39: Receiving hole;
[0134] 40: Fiber optic cable tray;
[0135] 41: First fiber optic slot;
[0136] 42: Second fiber optic slot;
[0137] 41a: Conical portion (second conical portion);
[0138] 41c: Conical portion (first conical portion);
[0139] 42b: Conical part;
[0140] 41b, 42a: Straight sections;
[0141] 50, 50A: Adapter;
[0142] 51: Insertion hole;
[0143] 52, 53, 54, 55: Inner surface;
[0144] 54a, 55a: V-shaped protrusion;
[0145] 54b, 55b: Semi-circular protrusions;
[0146] 54W: Wall portion;
[0147] 61: Hollow section;
[0148] A: Adhesive;
[0149] B: lid part;
[0150] C0: Center;
[0151] C1, C2, C3: Imaginary circles;
[0152] D1, D2, D3: Depth;
[0153] d1, d2, d3: Diameter;
[0154] L1, L2: Total length;
[0155] R: Distance;
[0156] S1, S2, S3: Inner surface;
[0157] W1, W2: Opening width.
Claims
1. A ferrule, comprising: Top surface; An opening is provided on the side opposite to the top surface in a first direction intersecting with the top surface; Multiple fiber optic slots extend along the first direction between the top surface and the opening, and are arranged side by side along a second direction intersecting the first direction, each capable of supporting multiple optical fibers; as well as Multiple lenses are respectively disposed on the extension lines of the multiple fiber optic slots. The fiber optic slot has: A first fiber groove is used to position the fiber relative to the lens; as well as The second fiber optic slot is used to guide the optical fiber into the first fiber optic slot. The first fiber slot is configured to be closer to the lens in the first direction than the second fiber slot. The first fiber optic slot includes: In the straight section, at each position along the first direction, the diameter of the imaginary circle centered on the optical axis of the lens and tangent to the first fiber groove is constant. as well as A first tapered portion is disposed in the first direction between the straight portion and the second fiber groove portion, and is inclined in such a way that the diameter of an imaginary circle centered on the optical axis of the lens and tangent to the first fiber groove portion increases as it moves away from the straight portion. The first fiber groove further includes a second tapered portion, which is disposed between the lens and the straight portion in the first direction, and is inclined in such a way that the diameter of an imaginary circle centered on the optical axis of the lens and tangent to the first fiber groove increases as it moves away from the straight portion.
2. The ferrule according to claim 1, wherein, In a cross-section perpendicular to the first direction, the first fiber groove and the second fiber groove are respectively V-shaped.
3. The ferrule according to claim 1 or 2, wherein, In a cross-section perpendicular to the first direction, the opening width of the second fiber groove is larger than the opening width of the first fiber groove.
4. The ferrule according to claim 1 or 2, wherein, In a cross-section perpendicular to the first direction, the depth of the second fiber groove is greater than the depth of the first fiber groove.
5. The ferrule according to claim 1 or 2, wherein, In a cross section perpendicular to the first direction, the diameter of an imaginary circle centered on the optical axis of the lens and internally tangent to the second fiber groove is larger than the diameter of an imaginary circle centered on the optical axis of the lens and internally tangent to the first fiber groove.
6. The ferrule according to claim 5, wherein, The second fiber optic slot includes: The straight section, at each position along the first direction, has a constant diameter of an imaginary circle centered on the optical axis of the lens and tangent to the second fiber groove; and The tapered portion is disposed on the opposite side of the first fiber groove portion relative to the straight portion in the first direction, and is inclined in such a way that the diameter of the imaginary circle centered on the optical axis of the lens and tangent to the second fiber groove portion increases as it moves away from the straight portion.
7. The ferrule according to claim 1 or 2, wherein, The total length of the second fiber groove in the first direction is greater than or equal to the total length of the first fiber groove in the first direction.
8. The ferrule according to claim 1 or 2, wherein, In the first direction, the second fiber groove is arranged at a predetermined interval from the first fiber groove.
9. The ferrule according to claim 1 or 2, further comprising: The upper surface, which is configured in a third direction intersecting the first and second directions, is positioned opposite the plurality of fiber slots. The upper surface has a window portion that opens in a region that is opposite to the first optical fiber groove portion in the third direction. When viewed from the third-party perspective, the first optical fiber slot is recessed inside the window.
10. The ferrule according to claim 9, wherein, The total length of the first fiber optic slot in the first direction is shorter than the width of the window in the first direction, and the total width of all the first fiber optic slots in the second direction is smaller than the width of the window in the second direction.
11. The ferrule according to claim 1 or 2, further comprising: A pair of side surfaces, which are arranged in the second direction at positions opposite each other across the plurality of fiber optic slots. Each of the two sides is provided with a guide portion to guide insertion of the adapter along the first direction.
12. The ferrule according to claim 1 or 2, wherein, The insert is integrated with the lens.
13. An optical connector, comprising: The ferrule as claimed in any one of claims 1 to 12; and The plurality of optical fibers are supported by the plurality of optical fiber slots and are respectively arranged on the optical axis of the plurality of lenses.
14. The optical connector according to claim 13, wherein, The optical fiber is fixed to the first optical fiber slot by an adhesive.
15. The optical connector according to claim 14, wherein, The ferrule has an upper surface that is positioned opposite the plurality of fiber slots in a third direction intersecting the first and second directions. The upper surface has a window portion that opens in a region that is opposite to the first optical fiber slot in the third direction. Inside the window, there is a cover disposed on the first optical fiber slot, separated by the optical fiber.
16. The optical connector according to claim 15, wherein, The first fiber optic slot includes a straight section, wherein at each position along the first direction, the diameter of an imaginary circle centered on the optical axis of the lens and tangent to the first fiber optic slot is constant. The cover is disposed in the region inside the window, in the region opposite to the straight section on the third direction.
17. The optical connector according to claim 15 or 16, wherein, The cover is a plate-shaped component that is separate from the ferrule and is configured to contact the plurality of optical fibers, which are respectively supported by the plurality of optical fiber slots.
18. The optical connector according to any one of claims 13 to 16, wherein, The total length of the first fiber groove in the first direction is set to be more than 3 times and less than 40 times the diameter of the fiber.