JP5117445B2 - Optical connector - Google Patents

Description

  The present invention relates to an optical connector provided in an optical transmission line, and more particularly to means for matching an optical axis of a first microlens provided in a base plate with an optical axis of a second microlens provided in a substrate. .

  In general, as means for easily positioning the first and second members connected to each other, a plurality of positioning pins can be implanted in one member and the positioning pin can be fitted to the other member. A means for opening a pin engagement hole and fitting the positioning pin into the pin engagement hole is used (see, for example, FIG. 1 of Patent Document 1).

8 and 9 are a plan view and a side view showing an example of an optical connector to which the technology described in Patent Document 1 is applied. As shown in these drawings, the optical connector of this example includes a base plate 1 and an optical connector. The first microlens group 2 provided on the base plate 1, a substrate 3 on which an optical modulator (E / O) and an optical demodulator (O / E) (not shown) are mounted, and the substrate 3 are provided. The second microlens group 4 and a plurality of (three in the example of FIG. 8 ) positioning pins attached to the substrate 3 by bonding or the like and arranged around the second microlens group 4 5. Each lens constituting the first to second microlens groups 2 and 4 is a collimator lens. The base plate 1 is provided with a pin engagement hole 6 into which the positioning pin 5 can be fitted at a position corresponding to the setting portion of the positioning pin 5, and the positioning pin 5 is fitted into the pin engagement hole 6. By doing so, the optical axis of each microlens constituting the first microlens group 2 is matched with the optical axis of each microlens constituting the second microlens group 4. As a result, it is possible to prevent optical coupling loss between each microlens constituting the first microlens group 2 and each microlens constituting the second microlens group 4, thereby realizing good light transmission efficiency. can do.

JP 2001-33763 A

  By the way, in the optical connector having the above-described configuration, the base plate 1 is generally formed of a metal plate such as stainless steel or aluminum, and the substrate 3 is generally formed of a composite material such as glass epoxy or a resin material. For this reason, the optical axis of each microlens constituting the first microlens group 2 and the light of each microlens constituting the second microlens group 4 under a predetermined temperature condition (for example, normal temperature) at the time of manufacture. Even if the axes closely match, if the environmental temperature changes and the base plate 1 and the substrate 3 expand and contract in the surface direction by an amount corresponding to the respective linear expansion coefficients, the optical axes of the microlenses are There is a problem that the optical coupling loss occurs.

  The present invention has been made in order to solve such a technical problem, and its purpose is that even when a base plate and a substrate made of materials having different linear expansion coefficients expand and contract according to changes in environmental temperature, An object of the present invention is to provide an optical connector capable of preventing the optical axis shift of each microlens provided in each of these members, and hence the occurrence of optical coupling loss resulting therefrom.

  In order to solve the above problems, the present invention includes a base plate, a first microlens provided in the base plate, a substrate formed of a material having a linear expansion coefficient different from that of the base plate, and the substrate. A second microlens, a plurality of positioning pins disposed around the second microlens and mounted on the substrate, and provided in the base plate, and in cooperation with the positioning pins, the first microlens. In the optical connector provided with a pin engaging hole for matching the optical axis of the microlens and the optical axis of the second microlens, the distal end portion of the positioning pin has a diameter as it reaches the distal end side of the positioning pin. Is formed into a tapered surface or a hemispherical surface, and the pin engaging hole is engaged with the tip end portion of the positioning pin when the tapered surface is formed. The base plate is formed in a shape that generates a component force in a direction along or along a tangent line of the hemispherical surface, and the base plate inserts the tip end portion of the positioning pin into the pin engaging hole, and the upper side of the base plate By applying elastic force to the substrate side, it is integrated with the positioning pin and the substrate, and when the environmental temperature changes, the component force in the direction along the taper surface or the tangential line of the hemisphere The base plate and the substrate are displaced in the direction away from the substrate against the elastic force by the amount of displacement corresponding to the difference in linear expansion coefficient.

  According to such a configuration, when the base plate and the substrate expand and contract by an amount of expansion and contraction corresponding to the linear expansion coefficient due to a change in environmental temperature, the taper surface that acts between the positioning pin and the pin engagement hole is aligned. Since the component force in the direction or the direction along the tangent line of the hemisphere increases, the base plate is displaced in a direction away from the substrate against the elastic force applied thereto. Therefore, even when an expansion / contraction difference occurs between the base plate and the substrate, the base plate and the substrate are not relatively displaced with respect to the surface direction, and the first microlens provided on the base plate and the first micro lens provided on the substrate are provided. It is possible to prevent the optical axis from being shifted with respect to the second microlens.

  Further, according to the present invention, as means for applying an elastic force to the base plate, a bolt screwed to the top of the positioning pin, and a spring disposed between the head of the bolt and the upper surface of the base plate It was configured to use a washer.

  According to such a configuration, by adjusting the bolt tightening torque, various elastic forces applied to the base plate can be adjusted. Therefore, various optical connectors having different elastic forces applied to the base plate can be easily manufactured. be able to.

  In the present invention, as a means for applying an elastic force to the base plate, a clip member made of a metal plate that engages both ends with the base plate and the substrate is used.

  According to such a configuration, since the optical connector can be assembled only by engaging the clip member having a required spring constant with the base plate and the substrate, the optical connector can be easily manufactured.

  Further, the present invention includes an upper member that is in contact with the upper surface of the base plate and a lower member that is in contact with the lower surface of the substrate, as means for applying an elastic force to the base plate, and between the base plate and the substrate. A case is used in which a casing that is integrally coupled with an elastic force applied is used.

  According to such a configuration, it is not necessary to prepare a special part for applying an elastic force to the base plate, so that the number of parts can be reduced and the assembly process can be simplified, and the cost of the optical connector can be reduced. be able to.

  Since the optical connector of the present invention is configured such that when the environmental temperature changes, the base plate is displaced in a direction away from the substrate, the first microlens provided on the base plate and the second microlens provided on the substrate are arranged. The optical axis deviation from the lens can be prevented, and the deterioration of the optical transmission efficiency due to the occurrence of optical coupling loss can be prevented.

It is a top view of the optical connector which concerns on 1st Embodiment. It is sectional drawing of the optical connector which concerns on 1st Embodiment. It is an enlarged view of the A section shown in FIG. It is explanatory drawing of the force which acts between the baseplate of the optical connector which concerns on 1st Embodiment, and a positioning pin. It is principal part sectional drawing of the optical connector which concerns on 2nd Embodiment. It is principal part sectional drawing of the optical connector which concerns on 3rd Embodiment. It is sectional drawing of the optical connector which concerns on 4th Embodiment. It is an optical connector top view which concerns on a prior art example. It is an optical connector side view which concerns on a prior art example.

  First, a first embodiment of an optical connector according to the present invention will be described with reference to FIGS. The optical connector of this example is characterized in that the shape of the tip portion of the positioning pin is a tapered surface, and the bolt 7 and the spring washer 8 are used as means for applying an elastic force to the base plate.

  As shown in FIGS. 1 to 3, the optical connector of this example is the same as the optical connector according to the conventional example shown in FIGS. 6 and 7 with respect to the basic configuration, and includes a base plate 1 and the base plate 1. A substrate 3 on which an optical modulator (E / O), an optical demodulator (O / E) and the like (not shown) are mounted, and a second micro-unit provided on the substrate 3. Microlens group 4 and a plurality of (three in the example of FIG. 6) positioning pins 5 which are attached to the substrate 3 by bonding or the like and are arranged around the second microlens group 4. is doing. The base plate 1 is provided with a pin engagement hole 6 into which the positioning pin 5 can be fitted at a position corresponding to the setting portion of the positioning pin 5, and the positioning pin 5 is inserted into the pin engagement hole 6. By fitting, the optical axes of the microlenses 2a to 2d constituting the first microlens group 2 and the optical axes of the microlenses 4a to 4d constituting the second microlens group 4 are matched. ing. The base plate 1 is formed of a metal plate such as stainless steel or aluminum, and the substrate 3 is formed of a composite material such as glass epoxy or a resin material. Moreover, a collimator lens is used as each microlens 2a-2d, 4a-4d.

  In this embodiment, as shown in FIGS. 2 and 3, the tip of the positioning pin 5 has a tapered surface whose diameter decreases uniformly as it reaches the tip. The taper surface has the same inclination as The positioning pin 5 has a screw hole 5a penetrating the top surface thereof, and a bolt 7 penetrating the pin engaging hole 6 of the base plate 1 is screwed into the screw hole 5a. A spring washer 8 is interposed between the bolt 7 and the base plate 1, and the bolt 7 is fastened to the base plate 1 with a required torque within a range where the spring washer 8 cannot be tightened beyond its elastic limit. Therefore, the base plate 1 can be displaced in a direction away from the substrate 3 against the elastic force of the spring washer 8 when receiving an upward force (direction of arrow Y shown in FIG. 2).

  As described above, in the optical connector of this example, the base plate 1 is formed of a metal plate such as stainless steel or aluminum, and the substrate 3 is formed of a composite material such as glass epoxy or a resin material. In this case, the base plate 1 and the substrate 3 expand / contract by different expansion / contraction amounts according to their respective linear expansion coefficients, and the lengths in the surface direction differ. In the optical connector of this example, the tip end portion of the positioning pin 5 has a tapered surface, and the pin engaging hole 6 has a tapered surface having the same inclination, so that the gap between the base plate 1 and the positioning pin 5 is When a horizontal force Fh corresponding to the difference in expansion / contraction between the base plate 1 and the substrate 3 is applied to the contact portion between the base plate 1 and the positioning pin 5 as shown in FIG. A component force Fa and a component force Fb in a direction perpendicular to the taper surface are generated, and a vertically upward base plate ascending force Fv, which is a resultant force, is generated. Thereby, the base plate 1 is displaced in a direction away from the substrate 3, and the base plate 1 and the substrate 3 are not relatively displaced in the surface direction.

  The displacement of the base plate 1 will be described in more detail with reference to FIG. 3. When the environmental temperature becomes high, the elongation amount of the substrate 3 formed of glass epoxy or the like is the elongation of the base plate 1 formed of metal or the like. 3, since the substrate 3 is displaced relative to the base plate 1 in the right direction as indicated by an arrow A in FIG. 3, the taper surface 5 b of the positioning pin 5 is an outer portion of the pin engaging hole 6. Strong contact with 6a. As a result, the base plate 1 is pushed up along the tapered surface 6a of the positioning pin 5 as indicated by an arrow C in FIG. On the other hand, when the environmental temperature becomes low, the shrinkage amount of the substrate 3 formed of glass epoxy or the like becomes larger than the shrinkage amount of the base plate 1 formed of metal or the like, as shown by an arrow B in FIG. Since the substrate 3 is displaced relative to the base plate 1 in the left direction, the taper surface 6a of the positioning pin 5 comes into strong contact with the inner portion 5c of the pin engaging hole 6. Thereby, also in this case, the base plate 1 is pushed up along the tapered surface 6a of the positioning pin 5, as indicated by an arrow C in FIG.

  Accordingly, it is possible to eliminate the deviation between the optical axes of the microlenses 2a to 2d constituting the first microlens group 2 and the optical axes of the microlenses 4a to 4d constituting the second microlens group 4. Thus, the optical coupling loss due to this can be eliminated. Moreover, since the collimator lens is used as the microlenses 2a to 2d and 4a to 4d, even when the base plate 1 is displaced in the direction away from the substrate 3, the optical coupling loss due to this is eliminated. Can do. Further, as described above, the first microlens group 2 provided on the base plate and the second microlens group 4 provided on the substrate, both when the environmental temperature becomes high and low, Is displaced in the direction of separation, the distance between the first microlens group 2 and the second microlens group 4 can be set to a minimum, and the optical connector can be thinned.

  Next, a second embodiment of the optical connector according to the present invention will be described with reference to FIG. The optical connector of this example is characterized in that the shape of the tip of the positioning pin 5 is spherical. Since the others are the same as those of the optical connector according to the first embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  The optical connector of this example has the same effect as the optical connector according to the first embodiment, and the shape of the tip of the positioning pin 5 is spherical, so that the gap between the positioning pin 5 and the pin engaging hole 6 is Thus, the vertical movement of the base plate 1 with respect to the positioning pin 5 can be made smooth.

  Next, a third embodiment of the optical connector according to the present invention will be described with reference to FIG. The optical connector of this example is characterized in that the base plate 1 and the substrate 3 are integrally coupled using a clip 9 instead of a bolt 7. The clip 9 is formed in a substantially U-shaped cross section using a metal plate having excellent elasticity such as stainless steel. Since the others are the same as those of the optical connector according to the first embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  The optical connector of this example has the same effect as the optical connector according to the first embodiment, and the base plate 1 and the substrate 3 are coupled using the clip 9, so that the assembly of the base plate 1 and the substrate 3 is facilitated. Thus, the optical connector can be easily manufactured.

  Next, a fourth embodiment of the optical connector according to the present invention will be described with reference to FIG. The optical connector of this example is obtained by integrally bonding the base plate 1 and the substrate 3 using a housing 13 composed of an upper member 11 in contact with the upper surface of the base plate 1 and a lower member 12 in contact with the lower surface of the substrate 3. Features. The upper member 11 and the lower member 12 are formed using a metal plate excellent in elasticity, such as stainless steel, and are integrally coupled with the base plate 1 and the substrate 3 in a state where an elastic force is applied. Since the others are the same as those of the optical connector according to the first embodiment, the corresponding parts are denoted by the same reference numerals and description thereof is omitted.

  The optical connector of this example has the same effect as that of the optical connector according to the first embodiment. In addition, since the base plate 1 and the substrate 3 are integrally coupled using the housing 13, an elastic force is applied to the base plate 1. Therefore, it is not necessary to prepare a special part for the purpose, the number of parts can be reduced, the assembly process can be simplified, and the cost of the optical connector can be reduced.

  In each of the above embodiments, the number of positioning pins 5 is three. However, the number of positioning pins 5 may be two or four or more.

  Hereinafter, specific examples will be given to clarify the effects of the present invention.

The base plate 1 was formed of stainless steel having a linear expansion coefficient of 1.7 × 10 ⁻⁵ / ° C., and the substrate 3 was formed of glass epoxy having a linear expansion coefficient of 6 × 10 ⁻⁵ / ° C. The set pitch of the positioning pins 5 and the opening pitch of the pin engagement holes 6 were 10 mm. In this case, when the environmental temperature rises by 60 ° C. from 25 ° C. to 85 ° C., the increase in the opening pitch of the pin engagement holes 6 is about 10.2 μm for the base plate 1, whereas the substrate 3 is An increase in the set pitch of the positioning pins 5 is about 36 μm, and a pitch shift of about 25.8 μm occurs between the base plate 1 and the substrate 3. Note that the optical axis deviation of the microlens groups 2 and 4 actually occurs at an intermediate position of the set pitch of the positioning pins 5, and therefore the pitch deviation at this portion is about 12.9 μm, which is half of that. It is assumed. This corresponds to a pitch shift in which an optical coupling loss of 14.9% occurs in the microlens groups 2 and 4. On the other hand, in the configuration of the present application, when the taper surfaces of the positioning pins 5 and the pin engagement holes 6 are 45 °, the base plate 1 is displaced in a direction away from the substrate 3 by about 12.9 μm. . Thereby, the optical axis shift between the first microlens group 2 provided on the base plate 1 and the second microlens group 4 provided on the substrate 3 is prevented.

DESCRIPTION OF SYMBOLS 1 Base plate 2 1st micro lens group 2a-2d Each micro lens which comprises a 1st micro lens group 3 Substrate 4 2nd micro lens group 4a-4d Each micro lens which comprises a 2nd micro lens group 5 Positioning Pin 5a Screw hole 6 Pin engagement hole 7 Bolt 8 Spring washer 9 Clip 11 Upper member 12 Lower member 13 Housing

Claims (4)

A base plate, a first microlens provided in the base plate, a substrate formed of a material having a linear expansion coefficient different from that of the base plate, a second microlens provided in the substrate, and the second And a plurality of positioning pins mounted on the substrate and provided on the base plate, and in cooperation with the positioning pins, the optical axis of the first microlens and the second microlens. In an optical connector having a pin engagement hole that matches the optical axis of the microlens,
The distal end portion of the positioning pin is formed in a tapered surface or a hemispheric surface whose diameter decreases as it reaches the distal end side of the positioning pin, and the pin engagement hole is engaged with the distal end portion of the positioning pin. It is formed in a shape that produces a component force in a direction along the tapered surface or in a direction along the tangent line of the hemispherical surface,
The base plate is integrated with the positioning pin and the substrate by inserting the tip end portion of the positioning pin into the pin engaging hole and applying an elastic force from the upper surface side of the base plate to the substrate side. When the environmental temperature changes, the component force in the direction along the taper surface or in the direction along the tangent line of the hemispherical surface, the displacement amount corresponding to the difference in linear expansion coefficient between the base plate and the substrate, An optical connector which is displaced in a direction away from the substrate against an elastic force.   As means for applying an elastic force to the base plate, a bolt screwed to the top of the positioning pin and a spring washer disposed between the head of the bolt and the upper surface of the base plate are used. The optical connector according to claim 1.   2. The optical connector according to claim 1, wherein a clip member made of a metal plate having both ends engaged with the base plate and the substrate is used as means for applying an elastic force to the base plate. .   As a means for applying an elastic force to the base plate, an upper member that contacts the upper surface of the base plate and a lower member that contacts the lower surface of the substrate, and the elastic force is applied between the base plate and the substrate The optical connector according to claim 1, wherein a housing that is integrally coupled with each other is used.

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