JP5899925B2 - Lens parts - Google Patents

Description

  The present invention relates to a lens component used for an optical module or the like.

  An optical module that converts an electrical signal into an optical signal or converts an optical signal into an electrical signal is known. Such an optical module includes an optical fiber, a photoelectric conversion element, and a lens component that guides light from the optical fiber to the photoelectric conversion element (see, for example, Patent Document 1).

JP 2009-163212 A

  By the way, a plurality of lens portions are arranged in a line in the lens component. Therefore, the lens component is formed as a long member along the arrangement direction of the lens portions. When such a lens component is used in a high temperature environment, thermal stress is generated in the lens component, and the lens component is deformed in a direction orthogonal to the arrangement direction of the lens portions. At this time, the bending direction of the lens component is bent in any direction within the plane orthogonal to the arrangement direction of the lens portions. For this reason, it is difficult to control the decrease in light coupling efficiency due to temperature changes in consideration of deformation in all directions in the plane.

  An object of the present invention is to provide a lens component that is not easily deformed as much as possible and that can be easily deformed in one direction even when the deformation occurs and the light coupling efficiency can be easily controlled.

  The lens component of the present invention capable of solving the above problems is a resin lens component optically coupled to an optical element, the plate-shaped portion extending from the lens portion in a predetermined direction with a substantially constant thickness, and the plate A pair of rib portions extending along the plate-like portion across the shape-like portion, and the cross-section perpendicular to the optical axis direction of the lens portion has the pair of rib portions projecting up and down from the plate-like portion. It is substantially H-shaped.

  In the lens component of the present invention, in the cross section orthogonal to the predetermined direction, the protruding length of the upper protruding portion protruding above the pair of rib portions is shorter than the protruding length of the lower protruding portion protruding downward, It is preferable that the width of the upper protrusion is wider than the width of the lower protrusion.

  The predetermined direction is preferably an arrangement direction of the plurality of lens portions. Moreover, it is preferable that the said plate-shaped part occupies the area | region of 50% or more of the full length of the said lens component in the said predetermined direction.

In the lens component of the present invention, in the cross section orthogonal to the optical axis direction of the lens portion, the protruding length of the upper protruding portion protruding above the pair of rib portions is longer than the protruding length of the lower protruding portion protruding downward. Short,
The width of the upper protrusion is wider than the width of the lower protrusion,
It is preferable that a reflective surface for optically connecting the additional lens portion having an optical axis different from the optical axis of the lens portion and the lens portion is provided on the upper surface of the plate-like portion.

In the lens component of the present invention, a flat surface is formed on the upper surface of the plate-like portion,
The flat surface is preferably adjacent to the reflective surface through a recess.

  According to the present invention, a plate-like portion extending in a predetermined direction from the lens portion and a pair of rib portions extending along the plate-like portion with the plate-like portion interposed therebetween are orthogonal to the optical axis direction of the lens portion. The cross section has a substantially H shape in which a pair of rib portions protrudes vertically from the plate-like portion. Thereby, the intensity | strength of a lens component can be raised significantly and the deformation | transformation by a thermal stress can be suppressed as much as possible. Further, even if the lens is slightly deformed, the deformation direction can be controlled in one direction along the direction orthogonal to the optical axis of the lens unit to suppress a decrease in light coupling efficiency. Thereby, optical transmission loss due to deformation in the direction along the optical axis can be suppressed.

It is a perspective view which shows the optical module provided with the lens array component which concerns on this embodiment. It is a perspective view which shows the state which removed the resin housing. It is a perspective view which shows the state which removed the housing. (A) is the figure which looked at the board | substrate shown in FIG. 3 from the top, (b) is the figure which looked at the board | substrate shown in FIG. 3 from the side. It is a top view of the lens array component which concerns on this embodiment. It is sectional drawing of the direction orthogonal to the optical axis of a lens array component. (A) And (b) is a figure explaining the cross-sectional secondary moment of a lens array component, respectively. It is sectional drawing which follows the optical axis of a lens array component. It is sectional drawing which follows the optical axis of the lens array component of a comparative example.

Hereinafter, an example of an embodiment of a lens component according to the present invention will be described with reference to the drawings.
The optical module according to the present embodiment is used for signal (data) transmission in optical communication technology or the like, and is electrically connected to an electronic device such as a personal computer to be connected to input / output electric signals. An optical signal is transmitted after being converted into a signal.

As shown in FIGS. 1 to 3, the optical module 1 is attached to an end of an optical cable 3. The optical cable 3 is a single-core or multi-core optical cable.
The optical cable 3 includes a plurality (four in this case) of optical fiber cores (optical elements) 7, a resin sheath 9 covering the optical fiber core 7, and the optical fiber core 7 and the sheath 9. And a metal braid 13 interposed between the outer cover 9 and the tensile strength fiber 11. That is, in the optical cable 3, the optical fiber core wire 7, the tensile strength fiber 11, the metal braid 13, and the jacket 9 are arranged in this order from the center toward the outside in the radial direction.

  As the optical fiber core 7, an optical fiber (AGF: All Glass Fiber) whose core and clad are quartz glass, an optical fiber (HPCF: Hard Plastic Clad Fiber) whose clad is made of hard plastic, and the like can be used. When a thin HPCF having a glass core diameter of 80 μm is used, it is difficult to break even if the optical fiber core wire 7 is bent to a small diameter.

  The jacket 9 is made of, for example, PVC (poly vinyl chloride) which is a non-halogen flame retardant resin. The outer diameter of the jacket 9 is about 4.2 mm. The tensile strength fiber 11 is, for example, an aramid fiber, and is built in the optical cable 3 in a bundled state.

  The metal braid 13 is made of, for example, a tin-plated lead wire, and has a braid density of 70% or more and a knitting angle of 45 ° to 60 °. The outer diameter of the metal braid 13 is about 0.05 mm.

  The optical module 1 includes a housing 20, an electrical connector 22 provided on the front end (tip) side of the housing 20, and a circuit board 24 accommodated in the housing 20.

  The housing 20 includes a metal housing 26 and a resin housing 28. The metal housing 26 includes a housing member 30 and a fixing member 32 that is connected to the rear end portion of the housing member 30 and fixes the optical cable 3.

  The housing member 30 is a cylindrical hollow member having a substantially rectangular cross section. The housing member 30 defines a housing space for housing the circuit board 24 and the like. An electrical connector 22 is provided on the front end side of the housing member 30, and a fixing member 32 is connected to the rear end side of the housing member 30.

  The fixing member 32 includes a plate-like base portion 34, a cylindrical portion (not shown) protruding toward the optical cable 3, a pair of first projecting pieces 38 projecting forward from both sides of the base portion 34, and both sides of the base portion 34. A pair of second projecting pieces 40 projecting rearward are provided. The pair of first projecting pieces 38 are respectively inserted from the rear part of the housing member 30 and are in contact with and connected to the housing member 30. A pair of 2nd overhang | projection piece 40 is connected with the boot 46 of the resin housing 28 mentioned later. The fixing member 32 includes a base portion 34, a cylindrical portion, a first overhanging piece 38, and a second overhanging piece 40 that are integrally formed of sheet metal.

  The tube portion has a substantially cylindrical shape and is provided so as to protrude rearward from the base portion 34. The tube portion holds the optical cable 3 in cooperation with caulking (not shown). Specifically, after the outer cover 9 is peeled off, the optical fiber core wire 7 of the optical cable 3 is inserted into the cylindrical portion, and the tensile fiber 11 is disposed along the outer peripheral surface of the cylindrical portion. And caulking is arrange | positioned on the tensile strength fiber 11 arrange | positioned on the outer peripheral surface of a cylinder part, and caulking is crimped. Thereby, the tensile strength fiber 11 is sandwiched and fixed between the cylindrical portion and the caulking ring, and the optical cable 3 is held and fixed to the fixing member 32.

  The end of the metal braid 13 of the optical cable 3 is joined to the base 34 with solder. Specifically, the metal braid 13 is disposed so as to cover the outer periphery of the caulking ring (cylinder portion) in the fixing member 32, and its end is extended to one surface (rear surface) of the base 34 and is soldered. It is joined. Thereby, the fixing member 32 and the metal braid 13 are thermally connected. Further, the fixing member 32 is coupled to the rear end portion of the accommodating member 30, whereby the accommodating member 30 and the fixing member 32 are physically and thermally connected. That is, the housing member 30 and the metal braid 13 of the optical cable 3 are thermally connected.

  The resin housing 28 is made of, for example, a resin material such as polycarbonate and covers the metal housing 26. The resin housing 28 includes an exterior housing 44 and a boot 46 connected to the exterior housing 44. The exterior housing 44 is provided so as to cover the outer surface of the housing member 30. The boot 46 is connected to the rear end portion of the exterior housing 44 and covers the fixing member 32 of the metal housing 26. The rear end portion of the boot 46 and the outer cover 9 of the optical cable 3 are bonded by an adhesive (not shown).

  The electrical connector 22 is a part that is inserted into a connection target (such as a personal computer) and is electrically connected to the connection target. The electrical connector 22 is disposed on the front end side of the housing 20 and protrudes forward from the housing 20. The electrical connector 22 is electrically connected to the circuit board 24 by a contact 22a.

  The circuit board 24 is accommodated in the accommodating space of the metal housing 26 (accommodating member 30). As shown in FIGS. 4A and 4B, a control semiconductor 50 and a light emitting / receiving element 52 are mounted on the circuit board 24. The circuit board 24 electrically connects the control semiconductor 50 and the light emitting / receiving element 52. The circuit board 24 has a substantially rectangular shape in plan view and has a predetermined thickness. The circuit substrate 24 is an insulating substrate such as a glass epoxy substrate or a ceramic substrate, and circuit wiring is formed on the surface or inside thereof by gold (Au), aluminum (Al), copper (Cu), or the like. . The control semiconductor 50 and the light emitting / receiving element 52 constitute a photoelectric conversion unit.

  The control semiconductor 50 includes a drive IC (Integrated Circuit) 50a, a CDR (Clock Data Recovery) device 50b that is a waveform shaper, and the like. The control semiconductor 50 is disposed on the front end side of the surface 24 a in the circuit board 24. The control semiconductor 50 is electrically connected to the electrical connector 22.

  The light receiving / emitting element 52 includes a plurality (here, two) of light emitting elements 52a and a plurality (here, two) of light receiving elements 52b. The light emitting element 52a and the light receiving element 52b are disposed on the rear end side of the surface 24a in the circuit board 24.

  As the light emitting element 52a, for example, a light emitting diode (LED: Light Emitting Diode), a laser diode (LD: Laser Diode), a surface emitting laser (VCSEL: Vertical Cavity Surface Emitting LASER), or the like can be used. For example, a photodiode (PD) can be used as the light receiving element 52b.

  The light emitting / receiving element 52 is optically connected to the optical fiber core wire 7 of the optical cable 3. Specifically, as shown in FIG. 4B, a lens array component (lens component) 55 is disposed on the circuit board 24 so as to cover the light emitting / receiving element 52 and the driving IC 50a.

  The lens array component 55 is connected to a connector component 54 attached to the end of the optical fiber core wire 7. The lens array component 55 inputs the light emitted from the light emitting element 52a to the optical fiber core 7 and inputs the light transmitted through the optical fiber core 7 to the light receiving element 52b. Thereby, the optical fiber core wire 7 and the light emitting / receiving element 52 are optically coupled.

  The optical module 1 having the above configuration is input from the electrical connector 22 to the control semiconductor 50 via the wiring of the circuit board 24. The electrical signal input to the control semiconductor 50 is output from the control semiconductor 50 to the light emitting / receiving element 52 via the wiring of the circuit board 24 after the level is adjusted and the waveform shaping is performed by the CDR device 50b. . The light emitting / receiving element 52 to which the electric signal is input converts the electric signal into an optical signal, and emits the optical signal from the light emitting element 52 a to the optical fiber core wire 7 through the lens array component 55.

  The optical signal transmitted through the optical cable 3 is incident on the light receiving element 52 b via the lens array component 55. The light emitting / receiving element 52 converts the incident optical signal into an electrical signal, and outputs the electrical signal to the control semiconductor 50 via the wiring of the circuit board 24. The control semiconductor 50 performs a predetermined process on the electrical signal and then outputs the electrical signal to the electrical connector 22.

  The lens array component 55 will be described with reference to FIGS. FIG. 5 is a plan view of the lens array component according to this embodiment, and FIG. 6 is a cross-sectional view in a direction perpendicular to the optical axis of the lens array component.

  As shown in FIG. 5, the lens array component 55 includes a plurality of fiber-side lens portions 62 provided at positions facing the optical fiber core wire 7 and a plurality of elements provided at positions facing the light emitting / receiving elements 52. The side lens part 65, the fiber side lens part 62 which has a mutually different optical axis, and the reflective surface 67 which optically connects the element side lens part 65 are provided. The plurality of fiber side lens portions 62 and the plurality of element side lens portions 65 are arranged side by side in one direction.

  The fiber side lens unit 62 and the element side lens unit 65 are formed of collimating lenses that convert incident light into parallel light and collect and output the parallel light. Such a lens array component 55 is integrally formed by resin injection molding.

  The lens array component 55 includes a plate-like portion 61 extending from the fiber side lens portion 62 in a predetermined direction. Specifically, the predetermined direction is a direction (upward direction in FIG. 5) that intersects the arrangement direction of the plurality of fiber side lens portions 62. The plate-like portion 61 is provided on the side opposite to the fiber side lens portion 62 with respect to the reflecting surface 67.

As shown in FIG. 6, the lens array component 55 has a pair of rib portions 63 extending along the plate-like portion 61 with the plate-like portion 61 interposed therebetween. 61 is formed integrally. The pair of rib portions 63 are formed so as to protrude upward and downward from the plate-like portion 61, whereby the lens array component 55 has a cross section orthogonal to the optical axis direction of the fiber side lens portion 62 having a substantially H shape. It is formed into a shape.
As shown in FIG. 5, rear end reinforcing ribs 70 that are continuous with the rib portions 63 are also formed on the side of the plate-like portion 61 opposite to the connection side.

  FIGS. 7A and 7B are diagrams for explaining the cross-sectional second moment of the lens array component 55. As shown in FIGS. 7A and 7B, in the cross section orthogonal to the optical axis direction of the fiber side lens portion 62, it is assumed that there is a virtual neutral surface C in the middle of the thickness direction of the plate-like portion 61. In this case, the sectional secondary moment I of the lens array component 55 is expressed by the following equation. In the following formula, a is the height of the rib portion 63 from the neutral surface C, d is the width of the rib portion 63, h is the width of the plate-like portion 61, and t is the plate-like portion from the neutral surface C. 61 height.

I = {ad ³ −h ³ (at)} / 12

  In the lens array component 55 according to the present embodiment, as shown in FIG. 6, each rib portion 63 protrudes upward from an upper protruding portion 63 a protruding upward in a cross section orthogonal to the optical axis direction of the fiber side lens portion 62. The length a1 is shorter than the protruding length a2 of the downward protruding portion 63b protruding downward. Further, the width s1 of the upper protrusion 63a is larger than the width s2 of the lower protrusion 63b. Thereby, the lens array component 55 is set so that the sectional secondary moment I is equivalent to the neutral plane C on the upper side and the lower side.

  Further, as shown in FIGS. 4A and 4B, a guide pin 69 protruding from the end of the rib portion 63 is formed on the fiber side lens portion 62 side of the lens array component 55. These guide pins 69 can be inserted into positioning holes 71 formed in the connection end face of the connector component 54. Then, by inserting these guide pins 69 into the positioning holes 71, the connector component 54 is positioned with respect to the lens array component 55, and the optical fiber core wire 7 is disposed at a position facing the fiber side lens portion 62. The

  In the lens array component 55 as described above, the optical signal from the optical fiber core wire 7 is incident from the fiber side lens portion 62, transmitted along the extending direction of the plate-like portion 61, and reflected by the reflecting surface 67. As a result, the optical path is changed downward, the light is emitted from the element side lens unit 65, and reaches the light receiving element 52 b of the light receiving and emitting element 52. Further, an optical signal from the light emitting element 52 a of the light receiving and emitting element 52 is incident on the element side lens portion 65 and reflected by the reflecting surface 67, thereby changing the optical path to the connection side, and in the extending direction of the plate-like portion 61. And is emitted from the fiber side lens portion 62 and reaches the optical fiber core wire 7.

  Thereby, an optical signal is transmitted between the optical fiber core wire 7 and the light emitting / receiving element 52 via the lens array component 55.

  The lens array component 55 is made of a resin with good dimensional accuracy by molding (for example, a polyetherimide resin), but it is preferable to use an electron beam cross-linking resin that can withstand high-temperature processing such as reflow. This is because, when a high temperature environment is generated by heat of electronic components such as the driving IC 50a and the light emitting / receiving element 52, when thermal stress is generated, the lens array component 55 is deformed and the optical transmission efficiency may be reduced due to the deviation of the optical axis. .

  The lens array component 55 according to the present embodiment includes a plate-like portion 61 extending in a direction intersecting with the arrangement direction of the fiber-side lens portions 62, and a pair of ribs extending along the plate-like portion 61 with the plate-like portion 61 interposed therebetween. Part 63. The cross section perpendicular to the optical axis direction of the fiber side lens portion 62 has a substantially H shape in which the pair of rib portions 63 protrudes vertically from the plate-like portion 61.

Thereby, the intensity | strength of the lens array component 55 can be raised significantly and the deformation | transformation by a thermal stress can be suppressed as much as possible. Further, the rib portion 63 to prevent deformation as bending the optical axis of the element-side lens unit 6 5, allowing only the in-plane direction of the deformation in Fig. That is, even if it is somewhat deformed, deformation in a direction in which the light coupling efficiency is difficult to decrease is allowed, and the deformation direction is allowed in only one direction. Also, it is easy to design the lens array part 55 in consideration of the high temperature thermal deformation. In order to realize the effect of such a design more remarkably, it is preferable that the plate-like portion 61 has a substantially constant thickness in a predetermined direction and further occupies 50% or more of the entire length of the lens array component 55.

  With respect to the lens array component 55, the element side lens portion 65 needs to be separated from the light emitting / receiving element 52 provided on the circuit board 24 by a predetermined distance. Must be set to length. However, since there is no such restriction above the lens array component 55, it is preferable to reduce the size above the lens array component 55.

  Accordingly, the rib 63 is set such that the protruding length a1 of the upper protruding portion 63a protruding upward is shorter than the protruding length a2 of the lower protruding portion 63b protruding downward. Thereby, the thickness of the lens array component 55 is reduced. Further, the upper protrusion 63a is set to have a width s1 wider than the width s2 of the lower protrusion 63b by the length of the protrusion length a1. Thereby, the reinforcement effect equivalent to the downward protrusion part 63b is set so that the upper protrusion part 63a can also be acquired. As a result, a lens array component 55 having a small thickness and high strength can be obtained.

  FIG. 8 is a cross-sectional view of the lens array component 55 along the optical axis. As shown in FIG. 8, the plate-like portion 61 has a recess 66 formed on the upper surface thereof. The recess 66 is an inclined surface in which the wall surface on the connection side is gradually inclined upward toward the connection side, and this inclined surface forms a part of the reflection surface 67. On the upper surface of the plate-like portion 61, a flat portion 68 formed in a planar shape is formed on the side opposite to the reflecting surface 67 with respect to the concave portion 66. The flat portion 68 is formed so as to be adjacent to the reflecting surface 67 through the concave portion 66.

  As described above, the flat portion 68 is formed so as to be adjacent to the reflective surface 67 through the concave portion 66, thereby providing the plate-shaped portion 61 having a sufficient strength and reducing the formation position of the reflective surface 67. can do. Thereby, the height dimension H of the lens array component 55 can be suppressed as much as possible to reduce the occupied space as much as possible, and the mounting in a narrow space can be facilitated. A specific example will be described with reference to FIG. 9 as a reference example.

  FIG. 9 is a sectional view taken along the optical axis of the lens array component of the reference example. As shown in FIG. 9, when the reflective surface 67 is formed without providing the recess 66, the formation position of the reflective surface 67 becomes high. Therefore, if the plate-like portion 61 has a thickness with sufficient strength, the height dimension H of the lens array component 55 is increased, and mounting in a narrow space becomes difficult.

  As mentioned above, although this invention was demonstrated using the embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above-described embodiment.

7: Optical fiber core wire (optical element), 52: Light emitting / receiving element (optical element), 55: Lens array component (lens component), 61: Plate-shaped portion, 62: Fiber side lens portion (lens portion), 63: Rib part, 63a: upward projecting part, 63b: downward projecting part, 65: element side lens part (additional lens part), 66: concave part, 67: reflecting surface, 68: flat part, a1, a2: projecting length, s1 , S2: width

Claims (3)

  A resin lens component,
  A plate-like portion extending with a certain thickness;
  A lens portion provided on the lower surface of the plate-like portion;
  A pair of rib portions extending along the plate-like portion across the plate-like portion;
  The length of the upper protruding portion protruding upward from the plate-like portion of the rib portion is shorter than the length of the lower protruding portion protruding downward from the plate-like portion of the rib portion,
  The width of the upper protrusion is wider than the width of the lower protrusion,
  The virtual neutral surface in the thickness direction of the plate-like portion is C, the height of the rib from the neutral surface C is a, the width of the rib portion is d, the width of the plate-like portion is h, When the height of the plate-like portion from the neutral plane C is t, I = {ad ³ -H ³ (At)} ^1/2 The lens component in which the cross-sectional secondary moment represented by is equal on the upper side and the lower side from the neutral surface. 2. The lens component according to claim 1, wherein a reflection surface that reflects light in a length direction of the plate-like portion to a lower side of the plate-like portion is provided on an upper surface of the plate-like portion . On the upper surface of the plate-like portion, a flat surface is formed,
The lens component according to claim 2 , wherein the flat surface is adjacent to the reflective surface through a recess.

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