JP4775148B2 - LENS MODULE, OPTICAL DEVICE, AND LENS MOUNTING METHOD - Google Patents

Description

  The present invention relates to a lens module, an optical apparatus, and a lens mounting method in which adjustment of a lens position is simple and accurate.

  Optical communication equipment incorporates light-emitting elements and light-receiving elements for optical transmission and reception, as well as several optical elements for optical coupling between these light-emitting elements and light-receiving elements and optical fibers that are external transmission paths. It is. For example, an optical transceiver includes a convex lens for collecting light from an optical fiber onto a light emitting or light receiving element.

  It is necessary to hold the lens at a predetermined distance (a distance at which the focus is achieved) with respect to the light emitting or receiving element. The light emitting and light receiving elements are supplied in a form housed in a CAN type package. The lens is supplied in the form of a lens component in which the lens is attached to an annular lens frame. Therefore, focusing can be performed by holding the lens component at a predetermined distance from the CAN package. The lens component is attached to the base member, and the base member is attached to the CAN type package. That is, the base member is for holding the lens component at a predetermined position. For this purpose, the base member has a lens component accommodation hole having an inner diameter substantially the same as the outer diameter of the lens component and an optical path hole penetrating the center of the lens component accommodation hole at a location facing the light emitting and light receiving elements. When the lens component is accommodated in the lens component accommodation hole and the base member is fixed to the CAN type package, the lens component is held at a position where the focal point is in focus.

  Actually, the holding position of the lens component can be slightly adjusted in the base member. That is, when the lens component is accommodated in the lens component accommodation hole, the position of the lens surface is not always at a suitable position as designed. The cause is a dimensional error of each member such as the lens thickness is not constant and the depth of the lens component accommodation hole is not constant (by cutting).

  As shown in FIG. 4, in the conventional adjustment method, a lens component accommodation hole 42 is formed slightly deep in the base member 44, and one or more spacers 46 are provided at the bottom of the lens component accommodation hole 42. The lens component 41 is stacked and stored on the spacer 46. The spacer 46 is a thin, perforated circular plate, a so-called flat washer, and the position of the lens component 41 (height from the bottom of the lens component receiving hole 42) is adjusted by appropriately adjusting the number of spacers 46. can do.

  Note that positioning in the two-dimensional direction perpendicular to the optical axis between the base member and the CAN type package, that is, optical axis alignment, need not be considered here.

JP-A-8-122581 JP-A-10-123385 Japanese Patent Laid-Open No. 5-88061

  As described above, the position of the lens component 41 is conventionally adjusted by the number of spacers 46 laid out. However, since this adjustment method involves trial and error, it is inevitable that it takes time.

  Further, in the conventional method, although the thickness of the spacer 46 is thin, it is finite, so that only discrete position adjustment is possible.

  In the conventional method, the position of the lens component 41 is actually adjusted by adjusting the height d from the bottom of the lens component receiving hole 42 to the lens component. What is truly desired to be adjusted is the distance from the light emitting or receiving element to the lens component (more precisely, to the lens).

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lens module, an optical apparatus, and a lens mounting method in which the above-described problems are solved and the lens position is easily and accurately adjusted.

In order to achieve the above object, a lens module according to the present invention includes a lens component in which a lens is attached to an annular lens frame, a lens component receiving hole having an inner diameter that can receive the lens component, and a bottom of the lens component receiving hole. a base member having an optical path hole through the center of the lens component receiving hole bottom and sandwiched between the lens part comprises a spring member elastically deformed, and the lens component receiving holes of the lens component And the lens component is fixed to the base member in a state of being located at a predetermined distance with respect to a reference surface formed on the base member.

  The spring member may be a C-ring formed so that both ends are staggered in the axial direction.

  The spring member may be formed by forming at least three raised portions protruding in the axial direction on the inner periphery or outer periphery of a circular elastic plate member having a hole in the center.

  The optical apparatus of the present invention is obtained by attaching the lens module to a package containing a light emitting or light receiving element.

The lens mounting method of the present invention forms a lens component having a lens mounted on an annular lens frame, and penetrates the bottomed lens component receiving hole and the center of the lens component receiving hole bottom with an inner diameter capable of receiving the lens component. forming a base member having an optical path hole, the lens component Nde write sandwiching the spring member between the upper Symbol lens component accommodating hole bottom and the lens component accommodated in the lens part receiving hole, pushing the lens component The lens component is positioned at a predetermined distance with respect to a reference surface formed on the base member while the spring member is elastically deformed by pressing with a jig, and the lens component is fixed to the base member in that state. It is.

In addition, the lens mounting method of the present invention opposes the light emitting or light receiving element to hold the lens component having the lens attached to the annular lens frame at a predetermined distance from the light emitting or light receiving element in the CAN type package. elastic place the lens part to form a base member having a lens component accommodating holes of the inner diameter and the optical path hole through the center of the lens component receiving hole capable of accommodating, at the bottom of the upper Symbol lens component accommodating hole in the axial direction When the deformable spring member is accommodated, the lens component is accommodated in the lens component accommodating hole so as to overlap the spring member, and the base member is fixed to the CAN type package. the surface in contact with a reference plane, a convex portion to be inserted into the lens component receiving holes protrude from the surface in contact with the surface and the reference surface in contact with the reference surface to a predetermined height The lens component is pressed into the lens component receiving hole by the convex portion of the push jig, and the lens component is brought into close contact with the convex portion by the elastic force of the spring member. The lens component is fixed to the lens component receiving hole.

  The present invention exhibits the following excellent effects.

  (1) The lens position can be easily adjusted.

  (2) The lens position can be adjusted accurately.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, in an optical transceiver to which the method of the present invention is applied, a lens component 1 having a lens attached to an annular lens frame is held at a predetermined distance with respect to a light emitting or receiving element in a CAN type package. Therefore, the lens component is accommodated in a place facing the light emitting or light receiving element, having an inner diameter that is substantially the same as the outer diameter of the lens component 1 and slightly larger than the outer diameter of the lens component 1 to the extent that the lens component 1 can be accommodated. A base member 4 having a hole 2 and an optical path hole 3 penetrating the center of the lens component accommodation hole 2 is formed, the lens component 1 is accommodated in the lens component accommodation hole 2, and the base member 4 is fixed to the CAN package. To do.

  At this time, in the present invention, the surface 5 of the base member 4 that contacts the CAN package is used as the reference surface S, and a spring member 6 that can be elastically deformed in the axial direction is accommodated at the bottom of the lens component accommodation hole 2. 6, the lens component 1 is accommodated, and a surface 7 that is in contact with the reference surface S and a convex portion 8 that protrudes from the surface 7 that is in contact with the reference surface S to a predetermined height H and is inserted into the lens component accommodation hole 2. The pushing jig 9 is used, and the lens component 1 is pushed into the lens component receiving hole 2 by the convex portion 8 of the pushing jig 9, whereby the lens component 1 is brought into close contact with the convex portion 8 by the elastic force of the spring member 6. Then, the lens component 1 is fixed to the lens component receiving hole 2.

  In the pushing jig 9, the surface 7 is formed precisely and flatly, and the top surface 10 of the convex portion 8 having a height H from the surface 7 is formed precisely and flatly. The back side of the surface 7 is easily formed so that the pushing jig 9 can be transported with a tool such as tweezers or a manipulator or pressed against the lens component 1. The spring member 6 is illustrated as a string-wound spring, but may be a leaf spring or an elastic body such as rubber.

  The lens component 1 has a lens attached to an annular lens frame. Here, the accuracy of the axial position of the lens with respect to the lens frame is not questioned. Also in the CAN type package, the distance accuracy from the light emitting or light receiving element to the exit side end surface of the CAN type package that comes into contact with the surface 5 of the base member 4 is required, but it is not questioned here. If the surface 11 facing the light emitting or light receiving element of the lens component 1 can be positioned at a predetermined distance from the emission side end surface of the CAN package, the object of positioning the lens at a predetermined distance from the light emitting or light receiving element is achieved. .

  When fixing the lens component 1 to the base member 4, first, the spring member 6 is accommodated in the bottom of the lens component accommodation hole 2. When the lens component 1 is accommodated on the spring member 6, the spring member 6 is not yet applied with a compressive force. Therefore, the spring member 6 has a natural length in the axial direction. Therefore, the lens component 1 is located at a position separating the natural length of the spring member 6 from the bottom of the lens component receiving hole 2, and the surface 11 of the lens component 1 is floated from the target position (closer to the reference surface S side). State). For this purpose, the depth of the bottom of the lens component housing hole 2 and the natural length of the spring member 6 as viewed from the reference plane S may be determined as appropriate.

  Next, the convex portion 8 is inserted into the lens component accommodation hole 2 so that the pushing jig 9 is overlapped with the lens component 1. Since the top surface 10 of the convex portion 8 is in contact with the surface 11 of the lens component 1, when the pushing jig 9 is pushed in, the lens component 1 remains in close contact with the convex portion 8 by the elastic force of the spring member 6. Is pushed toward the bottom of the lens component accommodation hole 2. In FIG. 1, the surface 7 of the pushing jig 9 is slightly separated from the surface 5 of the base member 4, but when the pushing jig 9 is pushed in, the surface 7 comes into close contact with the surface 5. The pushing jig 9 cannot be pushed any further. At this time, since the surface 7 = the surface 5 = the reference surface S, the top surface 10 of the convex portion 8 formed at the height H from the surface 7 is accurately positioned at a distance H from the reference surface S. Therefore, the surface 11 of the lens component 1 is accurately located at a distance D = H from the reference surface S.

  In this state, the lens component 1 is fixed to the lens component accommodation hole 2. Although the fixing method is not specified, the position of the lens component 1 does not change even if the pushing jig 9 is removed because the lens component 1 is fixed in the lens component receiving hole 2. A specific fixing method will be described later.

  After removing the pushing jig 9, the base member 4 is joined to the CAN package. Since the surface 5 of the base member 4 which is the reference surface S is in contact with the exit side end surface of the CAN type package, the surface 11 of the lens component 1 is accurately located at a distance H from the CAN type package. That is, the lens can be accurately positioned at a predetermined distance from the light emitting or light receiving element.

  From the above assembly process and parts and jig structures, the precision of the depth of the lens component accommodation hole 2 of the base member 4 need not be precise. Whether the hole forming method is cutting or molding can reduce the accuracy, which is advantageous for reducing the manufacturing cost. As long as the pushing jig 9 is manufactured with high accuracy, the mass-produced base member 4 may have low accuracy, so that the cost reduction effect is great.

  Compared with the conventional method of adjusting the number of the spacers 46 by trial and error, the axial length of the spring member 6 is variable in the present invention. There is no. Therefore, the man-hour relating to the positioning of the lens can be greatly reduced.

  Further, when changing the design of the lens position, it is possible to respond by changing the height H of the convex portion 8 of the pushing jig 9 without changing the component dimensions such as the depth of the lens component receiving hole 2 at all. . In other words, if a plurality of pushing jigs 9 having different heights H are used, the base member 4 can be shared among a plurality of types of optical transceivers or optical subassemblies having different specifications.

  Next, various forms of the spring member 6 will be described.

  The spring member 21 shown in FIG. 2 (a) is formed by bending both ends 22a and 22b of an elastic plate member 22 that has been turned almost once around an axis in the axial direction. The top view is a C-ring. In a side view, the thickness is formed in the axial direction by warping of both ends 22a and 22b. This is generally called a spring washer. Since the spring member 21 has a very simple structure, it can be easily manufactured. Commercial products can be used as they are.

  The spring members 23 and 24 shown in FIGS. 2 (b) and 2 (c) are arranged in the axial direction on the inner circumference or the outer circumference of the circular elastic plate members 25 and 26 having a hole at the center or the outer circumference. Raised raised portions 27 and 28 are formed, respectively. Since these spring members 23 and 24 are arranged with a plurality of raised portions 27 and 28 dispersed in the circumferential direction, the lens component 1 can be pressed and supported evenly in the circumferential direction.

  Next, a fixing method for fixing the lens component 1 to the lens component receiving hole 2 and a pressing method of the pressing jig 9 will be described more specifically.

  As shown in FIG. 3A, first, a thermosetting adhesive 31 is applied to the inner peripheral wall of the lens component accommodation hole 2 of the base member 4. Thereafter, the spring member 6 and the lens component 1 are inserted into the lens component accommodation hole 2, and the pushing jig 9 is placed on the lens component 1.

  Thereafter, as shown in FIG. 3B, the base member 4 is pushed in and set on the jig pressing member 32. The pushing jig pressing member 32 includes a pedestal 33 that supports the base member 4, a column 34 raised from the pedestal 33 to a predetermined height, a cross beam 36 that extends from the column 34 toward the back surface 35 of the pushing jig 9, and In order to push the back surface 35, a pressure screw 37 screwed into the cross beam 36 is provided. The pressing jig 9 is pressed by the pressure screw 37, and heating is performed in a state where the position of the lens component 1 is determined, and the thermosetting adhesive 31 is thermoset.

  Thereafter, as shown in FIG. 3C, the base member 4 is pushed out of the jig pressing member 32, and the pushing jig 9 is removed from the base member 4.

  Next, an optical subassembly in which a base member is attached to a CAN type package will be described. The optical subassembly is an intermediate product manufactured during the manufacturing process of the optical transceiver, and the base member and the CAN-type package are integrated into an optical subassembly, and the optical subassembly is incorporated into the optical transceiver housing. It is a thing.

  The optical subassembly 51 shown in FIG. 5 is formed with the base-end-side lens component receiving hole 52b and the front-end-side lens component receiving hole 52t facing each other, and a collimating light path 53 between the lens component-receiving holes 52b and 52t. The tied base member 54, the spring member 55 and the lens component 56 accommodated in the lens component accommodation holes 52b and 52t, the CAN package 57 attached to the base end side of the base member 54, and the tip of the base member 54 A ferrule 58 attached to the side, an optical fiber 59 connected to the ferrule 58, an optical connector 60 attached to a terminal of the optical fiber 59, a cap 62, and a ferrule folder 63. A portion excluding the CAN type package 57, the optical fiber 59, the ferrule 58, and the ferrule folder 63 is referred to as a lens module 61. The cap 62 is integral with the CAN type package 57. After removing the pushing jig 9, the cap 62 integral with the CAN package 57 is inserted.

  In the optical subassembly 51 of FIG. 5, a base part is fixed in order to fix the lens component 56 in a predetermined position with respect to the CAN type package 57 and fix the optical fiber 59 in a predetermined position with respect to another lens part 56. The lens module 61 was formed by sandwiching the spring member 55 between the lens component accommodation holes 52 b and 52 t of the member 54 and the lens component 56. However, the present invention is not limited to the CAN type package 57 and the optical fiber 59 that are to be fixed as in the optical subassembly 51 of FIG. 5, and is applicable to any optical subassembly in which the lens components 1 and 56 are incorporated.

  That is, the lens module 12 of the present invention excluding the pushing jig 9 from FIG. 1 forms a lens component 1 in which the lens is attached to an annular lens frame, and has a bottomed lens having an inner diameter substantially the same as the outer diameter of the lens component 1. In the lens module 12 in which the base member 4 having the component accommodation hole 2 and the optical path hole 3 passing through the center of the lens component accommodation hole bottom 2a is formed and the lens component 1 is accommodated in the lens component accommodation hole 2, the lens component accommodation is performed. The spring member 6 is sandwiched between the hole bottom 2a and the lens component 1 to be elastically deformed, and the lens component 1 is located at a predetermined distance from the reference plane S formed on the base member 4. It is fixed to the base member 4.

  By attaching such a lens module 12 to a package containing a light emitting or light receiving element, an optical subassembly for various optical devices can be obtained. In addition to the optical communication equipment such as the optical transceiver described in the embodiment, the optical equipment includes an optical head of an optical printer, an optical head of an optical disk device such as a CD and a DVD, and an optical head of a magneto-optical disk device such as an MD. is there.

It is a sectional side view of the base member which shows one Embodiment of the lens attachment method of this invention. (A), (b), (c) is the top view and side view of a spring member which are used for this invention. (A), (b), (c) is a sectional side view of the base member and the pushing jig pressing member showing the procedure of the lens mounting method of the present invention. It is a sectional side view of the base member by the conventional lens attachment method. 1 is an overall view (partially a side cross section) of an optical subassembly to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens component 2 Lens component accommodation hole 3 Optical path hole 4 Base member 5 Surface used as the reference surface S 6 Spring member 8 Convex part 9 Pushing jig 12 Lens module

Claims (6)

A lens component with a lens attached to an annular lens frame ;
A base member having a bottomed lens component accommodation hole with an inner diameter capable of accommodating the lens component, and an optical path hole penetrating the center of the lens component accommodation hole bottom ;
A spring member elastically deformed by being sandwiched between the lens component housing hole bottom and the lens component ;
With
The lens component accommodated in the lens component receiving holes, that is fixed to the base member in a state in which the lens part is positioned at a predetermined distance from the reference surface formed on the base member
Lenses module.   The lens module according to claim 1, wherein the spring member is a C-ring that is formed so that both ends thereof are staggered in the axial direction.   2. The lens module according to claim 1, wherein the spring member is formed by forming at least three raised portions protruding in the axial direction on the inner periphery or outer periphery of a circular elastic plate member having a hole in the center.   An optical apparatus comprising the lens module according to any one of claims 1 to 3 attached to a package containing a light emitting or light receiving element. Form a lens component with the lens attached to the annular lens frame,
Forming a base member having a bottomed lens component accommodation hole with an inner diameter capable of accommodating the lens component and an optical path hole penetrating the center of the lens component accommodation hole bottom ;
The lens component accommodated in the lens component receiving holes Nde write sandwiching the spring member between the upper Symbol lens component accommodating hole bottom and the lens part,
While pushing the lens component with a jig and elastically deforming the spring member, the lens component is positioned at a predetermined distance with respect to a reference surface formed on the base member, and in this state, the lens component is moved to the base. A lens mounting method for fixing to a member. In order to hold the lens component with the lens attached to the annular lens frame at a predetermined distance with respect to the light emitting or light receiving element in the CAN type package, the inner diameter that can accommodate the lens component in a place facing the light emitting or light receiving element. Forming a base member having a lens component accommodation hole and an optical path hole penetrating the center of the lens component accommodation hole ,
Bottom in the axial direction of the elastic deformation of the upper Symbol lens component accommodating hole accommodating a spring member capable, the lens part is housed in the lens component receiving holes superimposed on the spring member,
When the base member is fixed to the CAN type package, the surface of the base member that contacts the CAN type package is used as a reference surface, and the surface that contacts the reference surface and the surface that contacts the reference surface protrude to a predetermined height. By using a pressing jig having a convex portion inserted into the lens component receiving hole, and pressing the lens component into the lens component receiving hole with the convex portion of the pressing jig, the lens component is held by the elastic force of the spring member. brought into close contact with the convex portion and attach to the lens component receiving hole of the lens component in that state
Lenses mounting method.

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