Optical module and light connection structure
The optical module design with a movable ferrule holder and guide mechanism addresses the issue of increased parts and optical loss by ensuring precise alignment and stability under external forces, enhancing assembly efficiency and reducing costs.
Patent Information
- Application Number
- JP2024051486
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-27
- Publication Date
- 2025-10-09
AI Technical Summary
Existing optical modules face issues with increased parts and tolerances, leading to higher costs and potential optical loss due to the lack of a floating structure for the ferrule, which is fixed without freedom of movement, making it susceptible to positional shifts under external forces.
A ferrule holder with a stopper portion and position restriction, featuring a holder-side fitting portion that fits into a housing-side fitting portion, allowing the ferrule holder to move relative to the housing, and a guide mechanism using pins and holes for precise alignment.
The solution provides a simple structure with a floating function for the ferrule, reducing optical loss and assembly complexity while maintaining precise alignment, even under external forces.
Smart Images
Figure 2025150553000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to an optical module or the like that can be connected to other optical connectors. [Background technology]
[0002] For example, an ELS (External Light Source) module has been proposed that incorporates a light source and is capable of simultaneously performing optical and electrical connections (see, for example, Non-Patent Document 1). Such an ELS module has an optical connection section that can be connected to other connectors. [Prior art documents] [Non-patent literature]
[0003] [Non-Patent Document 1] "OIF Co-Packaging Interoperability Demo" OFC 2022,March 8-10-SanDiego CA(https: / / www.oiforum.com / wp-content / uploads / OIF_Co-Packaging_Demo_OFC2022_Presentation.pdf) Summary of the Invention [Problem to be solved by the invention]
[0004] In such an optical module, a ferrule having a waveguide connected to an internal light source must be fixed to the housing of the optical module. In this case, for example, one method is to attach the ferrule to a ferrule holder, and then fix this ferrule holder to a housing holder, and then attach the housing holder to the housing.
[0005] However, this method is undesirable because it increases the number of parts, which increases costs, and also increases the accumulation of tolerances when assembling parts. Therefore, a method is desired in which the ferrule is directly fixed to a ferrule holder that can be attached to the housing.
[0006] Typically, in an optical connection section where the waveguides of an optical connector are optically connected to each other, the ferrule inside the connector has a certain degree of freedom of movement relative to the connector body, etc. (a so-called floating structure) so that the optical connection can be maintained even when an external force is applied to the connector, etc. Without such a floating structure, the ferrule would be perfectly positioned and fixed in the connector body, and so deformation of the connector body would cause the ferrule to shift position, resulting in optical loss.
[0007] However, as mentioned above, the ferrule is fixed to the ferrule holder with no degree of freedom, so there is no floating structure between the ferrule and the ferrule holder. This means that the ferrule has no degree of freedom, and there is a risk of increased loss in the optical connection when an external force is applied to the connection with the connection target. In contrast, as mentioned above, if a floating structure is achieved by providing a separate member between the ferrule holder and the housing, the number of parts increases and tolerances accumulate, causing a deterioration in accuracy.
[0008] The present invention has been made in view of the above problems, and has an object to provide an optical module or the like that is capable of achieving a floating structure for a ferrule with a simple structure. [Means for solving the problem]
[0009] In order to achieve the above-mentioned object, a first invention is an optical module connectable to an optical connector, comprising a ferrule holder that holds a ferrule, and a housing in which the ferrule holder is attached, the ferrule holder having a stopper portion for preventing the ferrule holder from coming off the housing and a position restriction portion that restricts its position relative to the housing, the position restriction portion being a holder-side fitting portion formed on the outer surface of the ferrule holder, the holder-side fitting portion being able to fit into a housing-side fitting portion formed on the inner surface of the housing, a clearance being formed between the holder-side fitting portion and the housing-side fitting portion, and the ferrule holder being movable relative to the housing.
[0010] The holder-side fitting portion may be a protrusion formed on the outer surface of the ferrule holder, and the housing-side fitting portion may be a groove that fits into the protrusion-shaped holder-side fitting portion, and the holder-side fitting portion and the housing-side fitting portion may be fitted together to allow the ferrule holder to be slidably inserted from the front of the housing.
[0011] The end of the holder-side fitting portion and the end of the housing-side fitting portion have abutment portions that come into contact with each other when the ferrule holder is inserted to a predetermined depth from the front of the housing, and the abutment portion of at least one of the holder-side fitting portion or the housing-side fitting portion may be configured with a curved surface toward the abutment portion of the other.
[0012] A protrusion may be formed on the outer surface of the holder side fitting portion or the inner surface of the housing side fitting portion, and the clearance between the holder side fitting portion and the housing side fitting portion may be smaller at the location of the protrusion than at other locations.
[0013] According to the first aspect of the present invention, a clearance is formed between the holder-side fitting portion formed on the outer surface of the ferrule holder and the housing-side fitting portion formed on the inner surface of the housing, so that the ferrule holder can move relative to the housing. In other words, a floating structure can be formed between the ferrule holder and the housing. This allows the ferrule to move relative to the housing.
[0014] Furthermore, by configuring the holder-side fitting portion and the housing-side fitting portion as a groove and a protrusion that can fit together, the ferrule holder can be slid and inserted from the front of the housing.
[0015] Furthermore, since the abutment portion between the end of the holder-side fitting portion and the end of the housing-side fitting portion is configured as a curved surface, the contact area between the holder-side fitting portion and the housing-side fitting portion can be reduced, making it possible to move the ferrule holder efficiently relative to the housing.
[0016] Furthermore, by forming a protrusion on the outer surface of the holder-side fitting portion or the inner surface of the housing-side fitting portion and reducing the clearance at the protrusion compared to other portions, the protrusion can improve the positioning accuracy between the ferrule holder and the housing. Also, since the contact area between the holder-side fitting portion and the housing-side fitting portion can be reduced, the ferrule holder can be moved efficiently relative to the housing.
[0017] The second invention is a connection structure between an optical module and an optical connector according to the first invention, wherein the optical connector has an optical connection portion that is connected to the ferrule, and coarse guide protrusions that are inserted into the ferrule holder on both sides of the optical connection portion, and the coarse guide protrusions are inserted into the coarse guide insertion portions of the ferrule holder, and the ferrule and the optical connection portion are connected by a guide mechanism using pins and holes.
[0018] The coarse guide protrusion has a thick diameter portion at the tip of the thin diameter portion on the base side, and in the initial state when the coarse guide protrusion is inserted into the coarse guide insertion portion, the clearance between them is relatively small, and when the coarse guide protrusion is further inserted into the coarse guide insertion portion after the ferrule and the optical connection portion have been positioned by the guide mechanism, the clearance between the coarse guide protrusion and the coarse guide insertion portion may become relatively large.
[0019] According to the second invention, the coarse guide protrusions of the optical connector and the coarse guide insertion portions of the ferrule holder perform coarse positioning, thereby enabling the positioning of the pins and holes of the ferrule, which is the guide mechanism of the optical connection portion. In addition, the guide mechanism accurately positions the optical connection portion, allowing for efficient optical connection.
[0020] Furthermore, by making the base side of the coarse guide protrusion a narrow diameter portion and the tip a wide diameter portion, the clearance between the coarse guide protrusion and the coarse guide insertion portion can be made relatively small in the initial state when the coarse guide protrusion is inserted into the coarse guide insertion portion, thereby improving the positioning effect. On the other hand, when the coarse guide protrusion is further inserted into the coarse guide insertion portion after the optical connection portion of the optical module and the optical connector has been positioned by the guide mechanism, the clearance between the coarse guide protrusion and the coarse guide insertion portion becomes relatively large, allowing for greater movement and improving the floating function. [Effects of the Invention]
[0021] According to the present invention, it is possible to provide an optical module or the like that is capable of achieving a floating structure for a ferrule with a simple structure. [Brief explanation of the drawings]
[0022] [Figure 1] FIG. 2 is an exploded perspective view of the optical module 20. [Figure 2] FIG. 2 is an enlarged exploded perspective view of the ferrule holder 1 and the ferrule 3. [Figure 3] 1A is an assembled perspective view of the ferrule holder 1 and the ferrule 3, and FIG. 1B is an assembled plan view of the ferrule holder 1 and the ferrule 3. FIG. [Figure 4] FIG. 2 is an assembled perspective view of the optical module 20. [Figure 5] FIG. 2 is a front view of the optical module 20. [Figure 6] Cross-sectional view of line AA in Figure 5. [Figure 7] 1A is a perspective view of the optical connector 30, and FIG. 1B is a plan view of the optical connector 30. FIG. [Figure 8]1A is a plan view of the optical connector 30 and the ferrule 3 before they are connected, and FIG. 1B is a plan view of the optical connector 30 and the ferrule 3 after they are connected. [Figure 9] 1(a) is a diagram showing another structure in which the optical connector 30 and the ferrule 3 are connected, (b) is an enlarged view of part B in (a), and (c) is a diagram showing another embodiment of (b). [Figure 10] 1(a) is a diagram showing another structure in which the optical connector 30 and the ferrule 3 are connected, (b) is an enlarged view of part C in (a), and (c) is a diagram showing another embodiment of (b). [Figure 11] 10 is a diagram showing another structure in which the optical connector 30 and the ferrule 3 are connected. FIG. [Figure 12] 10(a) is a diagram showing another structure before the optical connector 30 and the ferrule 3 are connected, and FIG. 10(b) is an enlarged view of part D in FIG. [Figure 13] 4(a) and 4(b) are diagrams showing a process of connecting an optical connector 30 and a ferrule 3. FIG. DETAILED DESCRIPTION OF THE INVENTION
[0023] An optical module according to an embodiment of the present invention will now be described. Fig. 1 is an exploded perspective view of an optical module 20. Fig. 2 is an enlarged exploded perspective view of a ferrule holder 1 and a ferrule 3, Fig. 3(a) is an assembled perspective view of the ferrule holder 1 and the ferrule 3, Fig. 3(b) is an assembled plan view of the ferrule holder 1 and the ferrule 3, and Fig. 4 is an assembled perspective view of the optical module 20. The lower left side of Fig. 1 (the direction of connection with other optical connectors, which will be described later) is the front of the optical module 20, and the upper right side is the rear of the optical module 20. Similarly, the lower left side of Fig. 2 is the front of the ferrule holder 1, and the upper right side of Fig. 2 is the rear of the ferrule holder 1.
[0024] The optical module 20 can be connected to other optical connectors. The optical module 20 is composed of a ferrule holder 1, a ferrule 3, a housing 23, etc. The housing 23 contains, for example, a TOSA (Transmitter Optical Sub-Assembly) that houses a light source. That is, the optical module 20 is, for example, an ELS module. Note that the boards and electrical connectors housed in the optical module 20 are not shown. The optical module may also be something other than an ELS module.
[0025] The ferrule 3 has a waveguide such as an optical fiber inside, and is optically connected to a light source inside the housing 23. An end face (not shown) of the waveguide is exposed on the front surface of the ferrule 3. The number of waveguides exposed on the front surface of the ferrule 3 may be one or more.
[0026] 2, guide holes 11 are provided on both sides of the waveguide on the front surface of the ferrule 3. Guide pins to be connected, which will be described later, are inserted into the guide holes 11. A protrusion 4 is provided on the rear of the ferrule 3 so as to protrude at least in the vertical direction.
[0027] The ferrule holder 1 has a ferrule insertion hole 5 that penetrates and opens in the optical connection direction (from front to rear). A ferrule 3 can be inserted into the ferrule insertion hole 5.
[0028] Furthermore, coarse guide holes 7 are provided on both sides of the ferrule insertion hole 5 of the ferrule holder 1. The coarse guide holes 7 penetrate the ferrule holder 1 in the optical connection direction (from front to rear). The coarse guide holes 7 are locations into which coarse guide protrusions to be connected, which will be described later, are inserted.
[0029] Additionally, a pair of ferrule holding latches 9 are arranged at the rear of the ferrule holder 1, on both sides of the ferrule insertion hole 5. The ferrule holding latches 9 are arranged on both sides of the ferrule insertion hole 5 so that their claws face each other.
[0030] Furthermore, ferrule abutment portions 13 are provided between the ferrule holding latches 9. The ferrule abutment portions 13 are provided above and below between the ferrule insertion holes 5, and are portions that protrude in directions facing each other.
[0031] As shown in Figures 3(a) and 3(b), the ferrule 3 can be inserted into the ferrule insertion hole 5 from the rear of the ferrule holder 1. At this time, the ferrule holding latch 9 is deformed by pushing it open, and the ferrule 3 can be inserted into the ferrule insertion hole 5. Furthermore, when the ferrule 3 is pushed in until the protrusion 4 abuts against the ferrule abutment portion 13 of the ferrule holder 1, the deformation of the ferrule holding latch 9 is restored and the claw portion engages with the rear of the ferrule 3. In this way, the ferrule 3 is held in the ferrule holder 1.
[0032] As shown in Fig. 2, holder holding latches 19 are provided near both sides of the ferrule holder 1, facing rearward. Each holder holding latch 19 has a claw portion facing outward. Also, as shown in Fig. 1, a holder holding portion 27 is provided on the housing 23. The holder holding latches 19 can be engaged with the holder holding portion 27.
[0033] 2, a holder-side fitting portion 21 is provided on each side surface of the ferrule holder 1. The holder-side fitting portion 21 is formed on each side surface of the ferrule holder 1, has a protrusion shape that protrudes outward in the width direction, and is formed continuously from the front to the rear over a predetermined length.
[0034] 1, a housing-side fitting portion 25 is provided on the inner surface of the front side wall portion of the housing 23. The housing-side fitting portion 25 is a groove-like portion formed on the inner surface of each of both side walls of the housing 23. The housing-side fitting portion 25 opens at the front of the housing and extends continuously from the front to the rear for a predetermined length.
[0035] By sliding the ferrule holder 1 from the front of the housing 23 so that the holder-side fitting portion 21 of the ferrule holder 1 fits into the housing-side fitting portion 25 of the housing 23, the holder holding latch 19 engages with the holder holding portion 27, as shown in Fig. 4, and the ferrule holder 1 can be attached to the housing 23. In other words, the holder holding latch 19 functions as a retaining portion for the housing 23. The retaining mechanism for the ferrule holder is not particularly limited.
[0036] Fig. 5 is a front view of the optical module 20, and Fig. 6 is a cross-sectional view taken along line AA in Fig. 5. As described above, the groove-shaped housing-side fitting portion 25 provided on the inner surface of the housing 23 fits into the protrusion-shaped holder-side fitting portion 21 provided on the outer surface of the ferrule holder 1, thereby positioning the ferrule holder 1 at a predetermined position in the housing 23. That is, the holder-side fitting portion 21 fits into the housing-side fitting portion 25 and functions as a position restricting portion that restricts the position relative to the housing 23. Note that the cross-sectional shape perpendicular to the connection direction of the holder-side fitting portion 21 and the housing-side fitting portion 25 is not limited to the example shown in the figure, and may be formed of a curved surface such as a semicircle, or a polygonal shape such as a rectangle.
[0037] Here, a clearance is formed between the holder-side fitting portion 21 and the housing-side fitting portion 25. Therefore, when the ferrule holder 1 is attached to the housing 23, the ferrule holder 1 is movable relative to the housing 23. For example, the ferrule holder 1 is allowed to move relative to the housing 23 in the left-right direction and the height direction (direction perpendicular to the drawing) perpendicular to the left-right direction in FIG. 6, and in the rotational direction around the connection direction as the axis of rotation. In this way, because the position of the ferrule holder 1 is flexible relative to the housing 23, even when an external force is applied during connection with a connection target (described later), the ferrule 3 can move relative to the housing 23, maintaining the optical connection. In other words, a floating function can be achieved in the positional restriction portion between the holder-side fitting portion 21 and the housing-side fitting portion 25.
[0038] Next, a method for connecting the optical module 20 to another optical connector will be described. Fig. 7(a) is a perspective view showing the optical connector 30 to be optically connected, and Fig. 7(b) is a plan view of the optical connector 30. The optical connector 30 has a ferrule 31 with a built-in waveguide. That is, the waveguide (not shown) of the ferrule 31 of the optical connector 30 becomes an optical connection portion that is optically connected to the waveguide of the ferrule 3 fixed to the ferrule holder 1.
[0039] In the optical connector 30, the ferrule 31 has a known floating structure relative to the connector body. For example, an elastic member that presses the ferrule 31 in the connection direction is housed behind the ferrule 31, and deformation of the elastic member allows the ferrule 31 to move slightly relative to the connector body.
[0040] Guide pins 33 that protrude in the connection direction are provided on both sides of the optical connection portion of the ferrule 31. The guide pins 33 are inserted into the guide holes 11 of the ferrule 3 to be connected, and serve as parts for positioning during optical connection. That is, the guide pins 33 are arranged in pairs on both sides of the optical connection portion, at positions corresponding to the guide holes 11.
[0041] Coarse guide protrusions 35 are arranged on both sides of the ferrule 31 (optical connection portion) of the optical connector 30. The coarse guide protrusions 35 protrude in the direction of connection with the ferrule holder 1 (to the right in FIG. 7(b)). The cross-sectional shape of the coarse guide protrusions 35 may be circular or polygonal, such as rectangular. The coarse guide protrusions 35 are arranged at positions corresponding to the coarse guide holes 7 of the ferrule holder 1.
[0042] FIG. 8(a) is a diagram showing a state in which the optical connector 30 and the ferrule holder 1 attached to the housing 23 are opposed to each other. The housing 23 and the ferrule holder 1 are shown in cross section. When connecting the optical connector 30 and the ferrule holder 1, first, the coarse guide protrusions 35 of the optical connector 30 are inserted into the coarse guide holes 7. The cross section of the coarse guide protrusions 35 is smaller than the cross section of the coarse guide holes 7, and there is sufficient clearance, so that the coarse guide protrusions 35 can be easily inserted into the coarse guide holes 7. In this embodiment, the coarse guide holes 7 are described as having a hole shape into which the coarse guide protrusions 35 can be inserted, but the shape of the coarse guide insertion portion into which the coarse guide protrusions 35 can be inserted does not necessarily have to be a hole, and is not particularly limited as long as it has a shape into which the coarse guide can be inserted.
[0043] After the coarse guide protrusion 35 has been inserted a predetermined length into the coarse guide hole 7, the guide pin 33 is then inserted into the guide hole 11. FIG. 6(b) is a diagram showing the connection structure between the ferrule holder 1 and the optical connector 30, with the guide pin 33 inserted into the guide hole 11. By inserting the coarse guide protrusion 35 into the coarse guide hole 7 in this way, the guide pin 33 and the guide hole 11 can be roughly aligned, and the guide pin 33 can be inserted into the guide hole 11.
[0044] The guide pins 33 and guide holes 11, which are a guide mechanism for optical connection, align the end faces of the optical waveguides of the ferrules 3 and 31, thereby enabling optical connection.
[0045] Here, in the optical connection structure 40 between the optical module 20 and the optical connector 30, if an external force is applied near the connection, there is a risk of slight deformation of the connection between the housing 23 and the optical connector 30. In this case, as described above, the ferrule 31 of the optical connector 30 is slightly movable relative to the connector body, so even if the connector body is slightly deformed, it is possible to suppress fluctuations in the position of the ferrule 31 (relative position with respect to the ferrule 31).
[0046] On the other hand, the ferrule holder 1 is positioned relative to the housing 23 by the engagement of the holder-side fitting portion 21 and the housing-side fitting portion 25, but as described above, a clearance is formed between the holder-side fitting portion 21 and the housing-side fitting portion 25, and the ferrule holder 1 is movable relative to the housing 23. Therefore, even if the housing 23 is slightly deformed, fluctuations in the position of the ferrule 3 (relative position with respect to the ferrule 31) can be suppressed. In other words, the floating structures of the optical module 20 and the optical connector 30 respectively can minimize the impact on the optical connection portion.
[0047] As described above, according to this embodiment, by forming a clearance in the fitting portion between the ferrule holder 1 that holds the ferrule 3 and the housing 23, the ferrule holder 1 to which the ferrule 3 is fixed is allowed to move relative to the housing 23, and can function as a floating structure. Also, because the protruding holder-side fitting portion 21 is slid into and inserted into the groove-shaped housing-side fitting portion 25, assembly work is easy. Furthermore, because there is no need to use separate members, the structure is simple and assembly precision can be improved.
[0048] Next, a second embodiment will be described. Fig. 9(a) is a diagram showing the configuration of a ferrule holder 1 according to the second embodiment, and Fig. 9(b) is an enlarged view of part B in Fig. 9(a). In the following description, components that perform the same functions as those in the first embodiment are given the same reference numerals as in Figs. 1 to 8, and redundant description will be omitted.
[0049] The second embodiment is substantially similar to the first embodiment, but differs in the shape of the abutment portion 21a at the tip of the holder-side fitting portion 21 of the ferrule holder 1. The holder-side fitting portion 21 can be inserted into the housing-side fitting portion 25 until the tip of the protruding holder-side fitting portion 21 abuts against the deepest part of the groove-like housing-side fitting portion 25. In other words, the end of the holder-side fitting portion 21 and the end of the housing-side fitting portion 25 each have abutment portions 21a, 25a that come into contact with each other when the ferrule holder 1 is inserted to a predetermined depth from the front of the housing 23.
[0050] When the ferrule holder 1 is inserted into the housing 23 until the abutting portion 21a of the holder-side fitting portion 21 comes into contact with the abutting portion 25a of the housing-side fitting portion 25, the claw portion of the holder holding latch 19 described above engages with the holder holding portion 27 of the housing 23. At this time, a slight gap may be formed between the abutting portion 21a of the ferrule holder 1 and the abutting portion 25a of the housing 23.
[0051] In this embodiment, the abutting portion 21a of the holder-side fitting portion 21 is configured with a curved surface facing the abutting portion 25a of the housing-side fitting portion 25. By making the abutting portion 21a a curved surface in this manner, the ferrule holder 1 and the housing 23 can be brought into point contact at their abutting portions, and surface contact between them can be suppressed.
[0052] For example, if the abutting portion 21a of the holder-side fitting portion 21 and the abutting portion 25a of the housing-side fitting portion 25 are both flat, they will come into surface contact when they are abutted against each other. When they come into surface contact like this, the contact state between them becomes stable, hindering the relative movement of the two. In other words, there is a risk that the effect of the floating structure will not be fully exerted.
[0053] In contrast to this, by making the abutting portion 21a of the holder-side fitting portion 21 and the abutting portion 25a of the housing-side fitting portion 25 contact at a point, the contact state between them at the abutting portion can be made unstable, and even a slight force can move the ferrule holder 1 relative to the housing 23. In other words, the effect of the floating structure can be fully exerted.
[0054] 9(c), the abutting portion 25a of the housing-side fitting portion 25 may be configured with a curved surface facing the abutting portion 21a of the holder-side fitting portion 21. The same effect can be obtained even when the abutting portion 25a is configured with a curved surface in this way. That is, it is sufficient if the abutting portions 21a, 25a of at least one of the holder-side fitting portion 21 or the housing-side fitting portion 25 are configured with a curved surface facing the abutting portions 21a, 25a of the other.
[0055] According to the second embodiment, it is possible to obtain the same effects as those of the first embodiment. Furthermore, by forming the abutment portions 21a, 25a with curved surfaces when the ferrule holder 1 is slid into the housing 23, it is possible to facilitate the relative displacement of the ferrule holder 1 with respect to the housing 23, and it is possible to fully utilize the effect of the floating structure of the ferrule holder 1 with respect to the housing 23.
[0056] Next, a third embodiment will be described. Fig. 10(a) is a diagram showing the configuration of a ferrule holder 1 according to the third embodiment, and Fig. 10(b) is an enlarged view of part C in Fig. 10(a). The third embodiment is substantially the same as the first embodiment, but the configuration of the side surface of the holder-side fitting portion 21 of the ferrule holder 1 is different.
[0057] A protrusion 29 that protrudes outward in the width direction is formed on the outer surface of the holder-side fitting portion 21. The protrusion 29 is configured with, for example, a hemispherical curved surface. Because the protrusion 29 protrudes toward the inner surface of the housing-side fitting portion 25, the clearance between the holder-side fitting portion 21 and the housing-side fitting portion 25 is smaller at the location of the protrusion 29 than at other locations other than the protrusion 29.
[0058] In this way, the clearance between the holder-side fitting portion 21 and the housing-side fitting portion 25 is reduced at the protrusion 29, thereby improving the positioning accuracy between the ferrule holder 1 and the housing 23. On the other hand, at locations other than the protrusion 29, the clearance between the holder-side fitting portion 21 and the housing-side fitting portion 25 can be ensured, thereby achieving the effect of a floating structure.
[0059] 10(c), the protrusion 29 may be formed on the inner surface of the housing-side fitting portion 25, rather than on the holder-side fitting portion 21. Even in this case, the protrusion 29 protrudes toward the outer surface of the holder-side fitting portion 21, and therefore the clearance between the holder-side fitting portion 21 and the housing-side fitting portion 25 is smaller at the location of the protrusion 29 than at other locations other than the protrusion 29. In this way, by forming the protrusion 29 on at least one of the outer surface of the holder-side fitting portion 21 or the inner surface of the housing-side fitting portion 25, the clearance between the holder-side fitting portion 21 and the housing-side fitting portion 25 can be smaller at the location of the protrusion 29 than at other locations.
[0060] Although the protrusion 29 is disposed approximately in the center of the holder-side fitting portion 21 or the housing-side fitting portion 25 relative to the insertion direction of the ferrule holder 1 into the housing 23 (the vertical direction in FIG. 10(a)), the present invention is not limited to this. For example, by displacing the protrusion 29 toward the front side of the holder-side fitting portion 21 or the housing-side fitting portion 25 (downward in FIG. 10(a)), the positional accuracy of the end face side of the ferrule 3 can be improved. On the other hand, by displacing the protrusion 29 toward the rear side of the holder-side fitting portion 21 or the housing-side fitting portion 25 (upward in FIG. 10(a)), the degree of freedom in the position of the end face side of the ferrule 3 can be increased.
[0061] According to the third embodiment, it is possible to obtain the same effects as those of the first embodiment. Furthermore, by forming the protrusions 29 on the outer surface of the holder-side fitting portion 21 or the inner surface of the housing-side fitting portion 25, it is possible to improve the positional accuracy of the ferrule 3 while maintaining the floating structure.
[0062] Next, a fourth embodiment will be described. Fig. 11 is a diagram showing the fitted state between the ferrule holder 1 and the housing 23 according to the fourth embodiment. The fourth embodiment is substantially the same as the first embodiment, but the holder-side fitting portion 21 of the ferrule holder 1 is groove-shaped, and the inner surface of the housing-side fitting portion 25 of the housing 23 is formed in a protruding shape.
[0063] In this case, the ferrule holder 1 cannot be slid into the housing 23 from the front. Therefore, the ferrule holder 1 can be attached to the housing 23 by fitting the ferrule holder 1 into the housing 23 from above (in a direction perpendicular to the paper surface of FIG. 11).
[0064] According to the fourth embodiment, it is possible to obtain the same effects as those of the first embodiment. In this way, the holder-side fitting portion 21 does not necessarily have to be a protrusion, and the housing-side fitting portion 25 does not necessarily have to be a groove.
[0065] Next, a fifth embodiment will be described. Fig. 12(a) is a diagram showing the state before the ferrule holder 1 and the housing 23 according to the fifth embodiment are fitted together, and Fig. 12(b) is an enlarged view of part D in Fig. 12(a). The fifth embodiment is substantially the same as the first embodiment, but the shapes of the coarse guide protrusions 35 and the coarse guide holes 7 are different.
[0066] In this embodiment, the coarse guide projection 35 has a thin-diameter portion 35a with a relatively small diameter (including width or height; the same applies below) on the base side (left side of FIG. 12(b)), and a thick-diameter portion 35b with a relatively large diameter on the tip side of the thin-diameter portion 35a (right side of FIG. 12(b)). Also, the coarse guide hole 7 has a small-diameter portion 7a with a relatively small diameter on the front end side (left side of FIG. 12(b)), and a large-diameter portion 7b with a relatively large diameter on the rear side (right side of FIG. 12(b)). Note that the depth of the coarse guide hole 7 may be shortened to have only the small-diameter portion 7a.
[0067] 13(a) is a diagram showing the initial state in which the coarse guide protrusion 35 is inserted into the coarse guide hole 7. As described above, the tip side of the coarse guide protrusion 35 is the large diameter portion 35b, and the front end portion of the coarse guide hole 7 is the small diameter portion 7a, so that the large diameter portion 35b of the coarse guide protrusion 35 is first inserted into the small diameter portion 7a of the coarse guide hole 7. In other words, the small diameter portion 7a has a size that allows the large diameter portion 35b to be inserted therein.
[0068] Because the clearance between the large diameter portion 35b of the coarse guide protrusion 35 and the small diameter portion 7a of the coarse guide hole 7 is small, the ferrule holder 1 and the optical connector 30 are positioned with relatively high precision. Furthermore, when the coarse guide protrusion 35 is inserted into the coarse guide hole 7, the tip of the guide pin 33 of the ferrule 31 reaches the guide hole 11 of the ferrule 3 with the large diameter portion 35b positioned in the small diameter portion 7a. Therefore, the guide pin 33 and the guide hole 11 can be positioned with high precision.
[0069] 13(b), when the coarse guide protrusion 35 is further inserted into the coarse guide hole 7 and the guide pin 33 of the ferrule 31 is completely inserted into the guide hole 11 of the ferrule 3, the large diameter portion 35b of the coarse guide protrusion 35 passes through the small diameter portion 7a of the coarse guide hole 7 and is inserted up to the position of the large diameter portion 7b. In this state, the small diameter portion 35a of the coarse guide protrusion 35 is positioned in the small diameter portion 7a of the coarse guide hole 7, and therefore the clearance between the coarse guide protrusion 35 and the coarse guide hole 7 is larger than in the state of FIG.
[0070] This allows relative movement between the ferrule holder 1 and the main body of the optical connector 30. For example, as described above, the ferrule 31 has a floating structure relative to the main body of the optical connector 30. Therefore, even when the ferrule 31 and the ferrule 3 are completely fixed, the ferrule 31 and the ferrule 3 can move relative to the optical connector main body.
[0071] In addition, since the clearance between the coarse guide protrusions 35 and the coarse guide holes 7 is sufficiently large, the main body of the optical connector 30 and the ferrule holder 1 are relatively movable. Furthermore, since the ferrule holder 1 is also movable relative to the housing 23, the allowable range of movement of the ferrules 31 and 3 relative to the housing 23 can be increased. In this way, the floating functions of both the optical connector 30 and the optical module 20 can be efficiently exhibited.
[0072] According to the fifth embodiment, it is possible to obtain the same effects as in the first embodiment. Moreover, in the initial state where the coarse guide protrusion 35 is inserted into the coarse guide hole 7, the mutual clearance is made relatively small, so that the positions of the guide pin 33, which is the guide mechanism, and the guide hole 11 can be aligned with high precision. Furthermore, when the coarse guide protrusion 35 is further inserted into the coarse guide hole 7 after the optical connection portion of the ferrule 3 and the ferrule 31 has been positioned by the guide mechanism, the clearance between the coarse guide protrusion 35 and the coarse guide hole 7 can be made relatively large. Therefore, the positional constraint between the main body of the optical connector 30 and the ferrule holder 1 is reduced, and the floating function can be efficiently exhibited.
[0073] The coarse guide insertion portion into which the coarse guide protrusion 35 can be inserted does not have to be the coarse guide hole 7. For example, instead of the coarse guide hole 7, a notch-like shape without a beam portion on either the top or bottom may be used.
[0074] Although the present embodiment has been described using an ELS (External Light Source) module as an example, the scope of application of the present invention is not limited to ELS modules. For example, the present invention can also be applied to the optical connection parts of pluggable transceivers, which have been widely used in the optical communications field. In this case, by using the compact connector mechanism of the present invention, it is possible to install the connector in a smaller space than when using a conventional MPO connector, and it is also possible to install two or more connectors side by side.
[0075] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not limited to the above-described embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas described in the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention.
[0076] For example, it goes without saying that the configurations in the respective embodiments can be combined with each other. [Explanation of symbols]
[0077] 1...Ferrule holder 3...Ferrule 4....Convex part 5...Ferrule insertion hole 7....Rough guide hole 7a……Small diameter part 7b: Large diameter section 9...Ferrule retention latch 11...Guide hole 13: Ferrule butt section 19...Holder retention latch 20...Optical module 21...Holder side fitting portion 21a....Abutment part 23....Case 25………Fitting part on housing side 25a....Butt section 27...Holder holding part 29……protrusion 30...Optical connector 31...Ferrule 33...Guide pin 35.... Coarse guide protrusion 35a……Small diameter part 35b……Large diameter part 40...Optical connection structure
Claims
1. An optical module connectable to an optical connector, a ferrule holder for holding a ferrule; a housing in which the ferrule holder is mounted; Equipped with the ferrule holder has a retaining portion for preventing the ferrule holder from coming off the housing and a position restricting portion for restricting the position of the ferrule holder with respect to the housing, the position restriction portion is a holder-side fitting portion formed on an outer surface of the ferrule holder, and the holder-side fitting portion is capable of fitting with a housing-side fitting portion formed on an inner surface of the housing, An optical module, characterized in that a clearance is formed between the holder-side fitting portion and the housing-side fitting portion, and the ferrule holder is movable relative to the housing.
2. the holder-side fitting portion is a protrusion formed on an outer surface of the ferrule holder, and the housing-side fitting portion is a groove that fits into the protrusion-shaped holder-side fitting portion, 2. The optical module according to claim 1, wherein the ferrule holder can be slidably inserted from the front of the housing by fitting the holder-side fitting portion and the housing-side fitting portion together.
3. The optical module of claim 2, characterized in that the end of the holder-side fitting portion and the end of the housing-side fitting portion have abutment portions that come into contact with each other when the ferrule holder is inserted to a predetermined depth from the front of the housing, and the abutment portion of at least one of the holder-side fitting portion or the housing-side fitting portion is configured with a curved surface toward the abutment portion of the other.
4. An optical module as described in claim 2, characterized in that a protrusion is formed on the outer surface of the holder side fitting portion or the inner surface of the housing side fitting portion, and the clearance between the holder side fitting portion and the housing side fitting portion is smaller at the location of the protrusion than at other locations.
5. 5. A connection structure between the optical module according to claim 1 and an optical connector, The optical connector includes an optical connection portion that is connected to the ferrule; coarse guide protrusions inserted into the ferrule holder on both sides of the optical connection portion; and an optical connection structure in which the coarse guide protrusion is inserted into the coarse guide insertion portion of the ferrule holder, and the ferrule and the optical connection portion are connected by a guide mechanism using a pin and a hole;
6. The coarse guide protrusion has a thick diameter portion at the tip of the thin diameter portion on the base side, and in the initial state when the coarse guide protrusion is inserted into the coarse guide insertion portion, the clearance between them is relatively small, and when the coarse guide protrusion is further inserted into the coarse guide insertion portion after the ferrule and the optical connection portion are positioned by the guide mechanism, the clearance between the coarse guide protrusion and the coarse guide insertion portion becomes relatively large.