JP5727252B2 - Optical module structure - Google Patents

Description

  The present invention relates to a structure of an optical module for optically coupling an optical fiber and a FOT (Fiber Optic Transceiver).

  Among optical modules such as a hybrid connector (connector in which an optical connector and an electrical connector are integrated) and an optical connector, the technology of an optical module of a pigtail type is disclosed in, for example, Patent Document 1 below. Hereinafter, the structure of the disclosed optical module will be briefly described.

  In FIG. 7, the optical module includes a light emitting / receiving unit 1 mounted on a circuit board (not shown), a connector unit (not shown), and an optical fiber 2 that relays the light receiving / emitting unit 1 and the connector unit. . A ferrule 3 is provided at one end of the optical fiber 2. The optical fiber 2 is optically coupled to a FOT (Fiber Optic Transceiver) 4 of the light emitting / receiving unit 1 via a ferrule 3. The FOT 4 is connected and fixed to the circuit board in a state covered with the shield case 5.

  In the above configuration, when the ferrule 3 in a state where one end of the optical fiber 2 is fixed to the optical fiber fixing portion 6 is moved along the optical axis direction, the groove portion 7 formed in the ferrule 3 is a protrusion formed in the shield case 5. It is inserted into the plate 8. Then, when the locking projection 9 of the groove 7 and the locking frame portion 10 of the protruding plate 8 are hooked to form a locked state, the optical fiber fixing portion 6 is engaged with the light emitting / receiving portion 1 at this time. This completes the optical coupling.

JP 2009-145715 A

  By the way, in the said prior art, when the external force from the up-down direction shown by the arrow P is added, there exists a possibility that the protrusion board 8 of the shield case 5 may deform | transform. If deformation occurs, there is a problem that the ferrule 3 is dropped and affects the optical coupling.

  Moreover, in the said prior art, since the latching structure which only inserts the groove part 7 of the ferrule 3 in the protrusion board 8 of the shield case 5 is employ | adopted, the reverse assembly which inserts the ferrule 3 upside down is carried out. There is a risk of getting up. If reverse assembly occurs, there is a problem that optical coupling is affected.

  In addition, with respect to FOT4, there are FOT4 having a guide tube portion projecting in a cylindrical shape from the front surface and one having no guide tube portion, and the shape of the ferrule 3 side is determined by the FOT4 used. Have. In other words, there is room for improving versatility by reviewing the guide position.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an optical module structure capable of preventing dropout and reverse assembly and improving versatility.

The optical module structure of the present invention according to claim 1, which has been made to solve the above-mentioned problems, includes a FOT (Fiber Optic Transceiver) having an optical element, a FOT case for holding the FOT, and a shield for covering and shielding them. comprising a case, an optical fiber optically coupled to the optical element, and an optical fiber holder which engages with and the FOT case及beauty before Symbol shield case is provided to the optical fiber terminal, further, the FOT cases Around the holder engaging portion of the shield case, a case side fitting release restricting portion for external force from the direction intersecting the optical axis is provided so as to sandwich the optical fiber holder from above and below , and around the holder engaging portion of the shield case. the shield side disengagement restricting portion against an external force from a direction intersecting the optical axis, provided so as to sandwich the optical fiber holder in the width direction that And features.

  According to the present invention having such a feature, when an external force from a direction intersecting the optical axis is received, the force is hardly applied to the holder engaging portion by the disengagement restricting portion. Examples of “engagement” include “fitting”, “pressing”, “press-fitting”, and the like, which are fittings using a locking structure. The present invention may be any, but the above “fitting” is preferable.

  According to a second aspect of the present invention, there is provided an optical module structure according to the first aspect, wherein the optical fiber holder, the FOT case and / or the shield case are provided with a reverse assembly preventing portion. And

  According to the present invention having such characteristics, when the optical fiber holder is to be assembled upside down, for example, the assembly is restricted by the reverse assembly preventing portion. The reverse assembly preventing portion is effective in a structure that restricts the engagement of the optical fiber holder, that is, a structure that prevents the engagement.

  According to a third aspect of the present invention, there is provided the optical module structure according to the first or second aspect, wherein the FOT case is provided with a guide hole portion for guiding the optical fiber holding portion of the optical fiber holder. It is characterized by.

  According to the present invention having such characteristics, the optical fiber holder is guided by the guide hole of the FOT case when the optical fiber holder is assembled. The guide function is not affected by the shape of the FOT.

  According to the first aspect of the present invention, since the disengagement restricting portion is provided around the holder engaging portion, there is an effect that it is difficult to be influenced by an external force. Therefore, it is possible to prevent the dropout. According to the present invention, there is an effect that an optical coupling state can be maintained.

  According to the second aspect of the present invention, since the reverse assembly preventing portion is provided, there is an effect that the reverse assembly of the optical fiber holder can be prevented. As a result, it is possible to improve the assembly workability and to achieve normal optical coupling.

  According to the present invention described in claim 3, since the optical fiber holding portion of the optical fiber holder is guided by the guide hole portion of the FOT case, the structure can be made independent of the shape of the FOT, As a result, there is an effect that versatility can be improved.

It is a figure which shows the optical module structure of this invention, (a) is the perspective view which looked at the optical module from the right side, (b) is the perspective view which looked at the optical module from the left side. It is a disassembled perspective view of an optical module. It is a perspective view of a FOT case. It is a side view related to the assembly of the FOT holder and the FOT case, (a) is a diagram in the middle of assembly related to regular assembly, (b) is a diagram at the time of completion of assembly related to regular assembly, (c) is reverse assembly It is a figure of the assembly impossible state which concerns on. It is the expansion perspective view which looked at the optical module from the right side. It is the expansion perspective view which looked at the optical module from the left side. It is sectional drawing of the optical module structure of a prior art example.

  Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing an optical module structure of the present invention. 2 is an exploded perspective view of the optical module, FIG. 3 is a perspective view of the FOT case, FIG. 4 is a side view relating to the assembly of the FOT holder and the FOT case, and FIG. 5 is an enlarged perspective view of the optical module viewed from the right side. FIG. 6 is an enlarged perspective view of the optical module as viewed from the left side.

  In FIG. 1, among optical modules such as a hybrid connector (connector in which an optical connector and an electrical connector are integrated) and an optical connector, an optical module 21 of a pigtail type is a light emitting / receiving unit 22 mounted on a circuit board (not shown). And a pair of optical fibers 23 relaying the light receiving / emitting section 22 and the connector section, and an optical fiber holder 24 provided at the ends of the pair of optical fibers 23. The optical module 21 of this embodiment is provided for transmitting and receiving optical signals in a moving body such as an automobile (not limited to a moving body).

  The optical module 21 has a structure in which the ends of a pair of optical fibers 23 are optically coupled to the light emitting / receiving unit 22 using an optical fiber holder 24. This structure is realized by fitting the optical fiber holder 24 to the light emitting / receiving unit 22. Even if an external force is applied to the fitting portion of the optical fiber holder 24, the fitting is not released by the fitting release restricting means 25 (engagement releasing restricting portion) provided in the light emitting / receiving portion 22. It has become. The fitting release restricting means 25 will be described later.

  First, each component will be described. In the description, the arrow P is defined as the up-down direction, the arrow Q is defined as the left-right direction, and the arrow R is defined as the front-rear direction. The front-rear direction of the arrow R coincides with the direction of the optical axis. The direction in which the external force is applied is a direction that intersects the optical axis.

  1 and 2, the light emitting / receiving unit 22 includes two FOTs (Fiber Optic Transceivers) 26, a FOT case 27 for holding and fixing the two FOTs 26, and a shield case 28 for covering and shielding them. Configured.

  The FOT 26 includes an FOT main body 29 having optical elements (light emitting elements and light receiving elements), and a plurality of substrate connecting pins extending from the FOT main body 29, that is, lead frames 30. Two FOTs 26 are provided, one for the light emitting side and one for the light receiving side. The light emitting side FOT 26 has a light emitting element. The FOT 26 on the light receiving side has a light receiving element. Each optical element is connected to the corresponding lead frame 30 by wire bonding or the like.

  The FOT main body 29 is formed in such a shape that its front surface is pressed against the inner surface of the FOT case 27 when its rear surface is pressed by a FOT pressing spring (not shown) of the shield case 28. A recess 31 is formed on the front surface of the FOT main body 29 in accordance with the arrangement position of the optical element. Note that a guide tube portion protruding in a cylindrical shape may be formed instead of the recess 31 (as will be understood from the following description, the guide function for the optical fiber 23 side depends on the shape of the FOT main body 29). Not to be).

  Reference numeral 32 in the FOT main body 29 indicates a fixing hole. The fixing hole 32 is formed as a portion that is press-fitted into a FOT fixing protrusion (not shown) that protrudes from the inner surface of the FOT case 27.

  The lead frame 30 has a square cross section and is formed so as to extend downward from the lower portion of the FOT main body 29. The leading end of the lead frame 30 is inserted into a circuit board (not shown) and then soldered to a corresponding circuit. The lead frames 30 are arranged in a staggered pattern in this embodiment, but may be arranged in a horizontal row.

  2 and 3, the FOT case 27 is a resin molded product having an insulating property, and the case side fitting release provided on the front wall 33, the lower wall 34, the left and right side walls 35, and the front wall 33. It has a restriction part 36 (engagement release restriction part). In the FOT case 27, a portion surrounded by the front wall 33, the lower wall 34, and the left and right side walls 35 is formed as an FOT main body fixing portion 37, and the lower wall 34 is formed as a lead frame fixing portion 38.

  A pair of guide hole portions 39 are formed through the front wall 33. The pair of guide hole portions 39 are formed as portions for guiding an optical fiber holding portion 60 (see FIG. 1) described later of the optical fiber holder 24. That is, it is formed as a guide function part. The pair of guide hole portions 39 is disposed and formed in accordance with the position of the optical element (light emitting element, light receiving element) in the FOT 26. Around the pair of guide hole portions 39, a case side fitting release restricting portion 36 is provided.

  The case-side fitting release restricting portion 36 includes an upper protruding wall 40, a lower protruding wall 41, and a step 44 including an upper stage 42 and a lower stage 43. The case side fitting release restricting portion 36 is one of the fitting release restricting means 25. The step 44 is disposed between the upper protruding wall 40 and the lower protruding wall 41. The case-side fitting release restricting portion 36 is arranged and formed so that the upper protruding wall 40, the step 44, and the lower protruding wall 41 are arranged vertically from the upper side. This vertical arrangement is paired in the left-right direction. The upper protruding wall 40, the step 44, and the lower protruding wall 41 are formed in a shape that is substantially U-shaped when viewed from the side. Further, the upper protruding wall 40 and the lower protruding wall 41 are formed in a shape that sandwiches the optical fiber holder 24 (see FIG. 1) from above and below.

  The upper projecting wall 40 is an elongate wall (elongated wall projecting along the direction of the optical axis) that projects perpendicularly to the front wall 33 and faces the upper surface of the optical fiber holder 24 (see FIG. 1). It is arranged and formed as such. There are two upper protruding walls 40 as described above, and these are arranged at a predetermined interval. The upper protruding wall 40 is arranged according to the width dimension of the optical fiber holder 24. The upper protruding wall 40 has a slit 45 in the base end portion (near the front wall 33). A part of the shield case 28 (see FIG. 1) is inserted into the slit 45.

  Similarly to the upper protruding wall 40, the lower protruding wall 41 is a wall that protrudes perpendicularly to the front wall 33 (a wall that protrudes along the direction of the optical axis) and is wider than the upper protruding wall 40. Is formed in a wide shape. The lower protruding wall 41 is disposed and formed so as to face the lower surface of the optical fiber holder 24 (see FIG. 1). There are two lower projecting walls 41 as described above, and these are arranged at a predetermined interval. The lower protruding wall 41 is arranged according to the width dimension of the optical fiber holder 24.

  As described above, the step 44 includes the upper step 42 and the lower step 43, and is formed in a substantially staircase shape. The upper stage 42 is disposed on the upper protruding wall 40 side. The lower stage 43 is disposed on the lower protruding wall 41 side. The upper stage 42 is arranged so as to be located (projected) in front of the lower stage 43. The step 44 functions as a reverse assembly preventing portion 46 on the FOT case 27 side.

  The level difference 44 engages with a reverse assembly preventing portion 62 described later on the optical fiber holder 24 (see FIG. 1) side during assembly. At this time, when the steps do not match, the optical fiber holder 24 cannot be fitted (this will be described later with reference to FIG. 4).

  The upper stage 42 is also formed as an engaging portion of a meshing recess 63 described later of the optical fiber holder 24 (see FIG. 2). When the engaging recess 63 is engaged with the upper stage 42, the upper stage 42 can regulate the backlash and movement of the optical fiber holder 24 in the left-right direction.

  As can be seen from the above, the case-side fitting release restricting portion 36 (the upper protruding wall 40, the step 44, and the lower protruding wall 41) moves the optical fiber holder 24 (see FIG. 1) in the vertical direction and the horizontal direction. It is formed as a part that can be regulated. That is, it is formed in a structure that is strong against external force from the direction intersecting the optical axis. The case side fitting release restricting portion 36 is disposed and formed at a position around the fitting portion (engaging portion) of the optical fiber holder 24.

  The FOT case 27 has locking protrusions 47 on the left and right side walls 35, respectively. The locking projection 47 is formed as a portion that hooks the shield case 28 (see FIG. 1) to prevent this from coming off.

  1 and 2, the shield case 28 is formed by pressing a conductive metal plate. The shield case 28 is formed in a substantially box-like shape with an open bottom as shown. The shield case 28 is formed so as to be able to take measures against electromagnetic noise. The shield case 28 includes a lower opening 48, an upper wall 49, left and right side walls 50, a front wall 51, a rear wall 52, a holder fitting portion 53, and a shield side fitting release restriction portion 54 (engagement). A joint release restricting section).

  The shield case 28 can cover the FOT case 27 in a state where the FOT 26 is held and fixed by inserting the FOT case 27 from the lower opening 48 toward the upper wall 49. The shield case 28 is locked and fixed when the locking protrusion 47 of the FOT case 27 is caught by the locking portions 55 of the left and right side walls 50.

  The front wall 51 is provided with a pair of holder fitting portions 53 and a shield side fitting release restricting portion 54. The holder fitting portion 53 is formed so as to open the front wall 51 at a right angle with a substantially double sound. The holder fitting portions 53 are arranged and formed so as to face each other at intervals corresponding to the width dimension of the optical fiber holder 24. A rectangular fitting hole 56 is formed through the holder fitting portion 53. The fitting hole 56 is formed as a portion in which the optical fiber holder 24 is hooked and brought into a fitting state.

  The shield-side fitting release restricting portion 54 is one of the fitting release restricting means 25 and is formed by bending the lower side of the holder fitting portion 53 at a right angle. The shield-side fitting release restricting portion 54 is formed as a portion that prevents external force from acting on the holder fitting portion 53 that is a fitting portion (engagement portion) of the optical fiber holder 24. When external force is applied to the shield-side fitting release restricting portion 54, the case-side fitting release restricting portion 36 (the lower protruding wall 41) of the FOT case 27 is restricted from falling inward in the left-right direction. It is like that. In addition, the shield side fitting cancellation | release regulation part 54 is formed also in the shape which can regulate the fall of the holder fitting part 53 to the left-right direction outer side.

  In the lower opening 48, a plurality of substrate connections 57 and substrate fixing legs 58 are formed in a pin shape. On the rear wall 52, a FOT pressing spring (not shown) that presses the FOT 26 (the rear surface of the FOT main body 29) is formed.

  The optical fiber holder 24 is a resin molded product having an insulating property, and is a rectangular holder body 59 having a substantially block shape, and a pair of optical fiber holders 60 partially protruding from the front surface of the holder body 59. (The shape shown in the figure is an example).

  On both the left and right sides of the holder main body 59, flexible fitting projections 61 (engaging portions) are formed. Moreover, the reverse assembly | attachment prevention part 62 (refer FIG. 4) is formed in the front side rather than the fitting protrusion part 61 (engagement part), respectively. Further, meshing recesses 63 are formed in the vicinity of the reverse assembly preventing portion 62.

  The reverse assembly preventing portion 62 has a step shape, and includes a first step portion 64 located on the upper side and a second step portion 65 located on the lower side. The first step portion 64 is disposed and formed at a position such that the distance from the rear surface of the holder main body 59 is shorter than the second step portion 65. The first step portion 64 and the second step portion 65 are formed in accordance with the steps of the upper step 42 and the lower step 43 of the FOT case 27 (see FIG. 4).

  When the first step portion 64 and the second step portion 65 are turned upside down, that is, when the optical fiber holder 24 is reversely assembled, the optical fiber holder 24 cannot be fitted due to the step. (See FIG. 4. By changing the position of the fitting protrusion 61, the fitting is disabled).

  The meshing concave portion 63 is formed in a concave shape as a portion that engages with the step 44 (upper step 42) of the FOT case 27. When the meshing recess 63 is engaged with the upper stage 42, it is possible to regulate the backlash and movement of the optical fiber holder 24 in the left-right direction.

  The optical fiber holding part 60 is formed as a part for holding and fixing the optical fiber 23 inserted from the rear surface side of the holder main body 59. The optical fiber holding part 60 is formed as a part that functions in the same manner as a known ferrule. The optical fiber holding portion 60 is also formed as a portion that is inserted and guided into the guide hole 39 of the FOT case 27.

  In this embodiment, a known POF (Plastic Optical Fiber) is used for the optical fiber 23 (it is not limited to this).

  Next, the assembly of the optical module 21 will be described based on the above configuration and structure.

  In FIG. 2, when two FOTs 26 are held and fixed to the FOT main body fixing part 37 of the FOT case 27 and these are covered with the shield case 28, the assembly of the light emitting / receiving part 22 is completed. Then, when the light receiving / emitting unit 22 is mounted on a circuit board (not shown) and the optical fiber holder 24 is fitted to the light receiving / emitting unit 22, the end face of the optical fiber 23 is optically opposed to the optical element of the FOT 26 at this time. Complete combination.

  In the optical fiber holder 24, the fitting protrusion 61 is hooked and locked in the fitting hole 56 of the holder fitting portion 53 of the shield case 28. This engagement forms a fitting state of the optical fiber holder 24. Around the fitting portion, the shield side fitting release restricting portion 54 of the shield case 28 and the case side fitting release restricting portion 36 of the FOT case 27 (the upper protruding wall 40, the step 44, and the lower protruding wall 41). And has a structure strong against external force from the direction intersecting the optical axis.

  When specifically explaining the strong structure, the pair of upper protruding walls 40 function (receive external force) with respect to the external force (see arrow P1) from above shown in FIGS. If external force from above is applied to the upper surface of the optical fiber holder 24, the pair of lower protruding walls 41 function (receive external force).

  In addition, the pair of lower protruding walls 41 function with respect to an external force (see arrow P2) from below. If an external force from below is applied to the lower surface of the optical fiber holder 24, the pair of upper protruding walls 40 function.

  Further, the left shield side fitting release restricting portion 54 functions for an external force from the left (see arrow Q1). If an external force from the left acts on the side surface of the optical fiber holder 24, the right engaging recess 63 functions to engage with the right step 44. It should be noted that the left shield-side mating release restricting portion 54 does not fall inward in the left-right direction at the left lower projecting wall 41.

  Further, the right shield side fitting release restricting portion 54 functions with respect to the external force from the right side (see the arrow Q2). If an external force from the right acts on the side surface of the optical fiber holder 24, the left engaging recess 63 functions to engage with the left step 44. It should be noted that the right shield-side mating release restricting portion 54 does not fall inward in the left-right direction at the right lower projecting wall 41.

  As described above with reference to FIGS. 1 to 6, according to the optical module 21, the shield side fitting release restricting portion 54 of the shield case 28 and the case of the FOT case 27 are provided around the holder engaging portion. Since the side fitting release restricting portion 36 (the upper protruding wall 40, the step 44, and the lower protruding wall 41) is provided, there is an effect that it is difficult to be influenced by an external force. Therefore, the optical fiber holder 24 can be prevented from falling off. According to the optical module 21, there is also an effect that the optical coupling state can be maintained.

  Further, according to the optical module 21, the FOT case 27 is provided with the reverse assembly preventing portion 46, and the optical fiber holder 24 is also provided with the reverse assembly preventing portion 62, thereby preventing the optical fiber holder 24 from being reversely assembled. There is an effect that can be. As a result, it is possible to improve the assembly workability and to achieve normal optical coupling.

  Furthermore, according to the optical module 21, since the optical fiber holding part 60 of the optical fiber holder 24 is guided by the guide hole part 39 of the FOT case 27, the structure can be made independent of the shape of the FOT 26, As a result, there is an effect that versatility can be improved.

  It goes without saying that the present invention can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 21 ... Optical module 22 ... Light emitting / receiving part 23 ... Optical fiber 24 ... Optical fiber holder 25 ... Fitting release control means (engagement release control part)
26 ... FOT
DESCRIPTION OF SYMBOLS 27 ... FOT case 28 ... Shield case 29 ... FOT main body 30 ... Lead frame 31 ... Recess 32 ... Fixing hole 33 ... Front wall 34 ... Lower wall 35 ... Side wall 36 ... Case side fitting release restriction part (engagement release restriction part) )
37: FOT body fixing part 38 ... Lead frame fixing part 39 ... Guide hole part 40 ... Upper protruding wall 41 ... Lower protruding wall 42 ... Upper stage 43 ... Lower stage 44 ... Step 45 ... Slit 46 ... Reverse assembly prevention part 47 ... Locking Projection 48 ... Lower opening 49 ... Upper wall 50 ... Side wall 51 ... Front wall 52 ... Rear wall 53 ... Holder fitting part 54 ... Shield-side fitting release restriction part (engagement release restriction part)
55 ... Locking portion 56 ... Fitting hole 57 ... Substrate connection 58 ... Substrate fixing leg 59 ... Holder body 60 ... Optical fiber holding portion 61 ... Fitting protrusion 62 ... Reverse assembly preventing portion 63 ... Matching concave portion 64 ... First Step 65 ... Second step

Claims (3)

An FOT (Fiber Optic Transceiver) having an optical element, an FOT case for holding the FOT, a shield case for covering and covering these, an optical fiber optically coupled to the optical element, and an optical fiber terminal provided and an optical fiber holder for engaging the FOT case及beauty before Symbol shield case, further, the the holder engagement portion around the FOT cases, the case-side fitting against an external force from a direction intersecting the optical axis A release restricting portion is provided so as to sandwich the optical fiber holder from above and below , and a shield side fitting release restricting portion against an external force from a direction intersecting the optical axis is provided around the holder engaging portion of the shield case. An optical module structure, wherein a fiber holder is provided so as to be sandwiched from the width direction . The optical module structure according to claim 1,
An optical module structure, wherein a reverse assembly preventing portion is provided in the optical fiber holder and the FOT case and / or the shield case. The optical module structure according to claim 1 or 2,
An optical module structure characterized in that a guide hole for guiding the optical fiber holding portion of the optical fiber holder is provided in the FOT case.

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