JP3483221B2 - Optical module - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical module used in an optical signal transmission system, which can be easily assembled and has a low component cost. 2. Description of the Related Art Conventionally, as an optical module for optically coupling a light emitting element or a light receiving element with an optical fiber, for example, Japanese Utility Model Publication No. 3-34725, Japanese Patent Application Laid-Open No. 4-165512 or Japanese Patent Application Laid-Open No. 6-67063. What is described in Unexamined-Japanese-Patent No. 2000-222 is known. [0003] In the optical module described in Japanese Utility Model Publication No. 3-34725, an optical device having a light emitting element or a light receiving element is fixed to the optical module body by bonding or screws. The optical module described in Japanese Patent Application Laid-Open No. 4-165312 discloses a method of fixing a receptacle provided with a light emitting element or a light receiving element to a housing by crimping a housing around a flange 2 of the receptacle, or If is made of resin, it is riveted by pressing it with a plate material or fixed by local melting. Further, in the optical module described in Japanese Patent Application Laid-Open No. 6-67063, two housing blocks are integrally assembled into one housing. [0004] As described above, in the case of fixing with an adhesive or a screw, the assembling work is troublesome, and in the case of using a screw, in particular, costs such as thread cutting are incurred. Further, a member (flange) for fixing to a housing as disclosed in JP-A-4-165312.
Is provided on the receptacle side, the configuration of the device becomes complicated. Further, in the structure disclosed in JP-A-6-67063, the two housing blocks cannot be integrated with one touch, and the assembly is troublesome. [0005] In order to solve the above-mentioned problems, the present invention relates to an optical module into which a plug having an optical fiber is inserted, wherein the optical module is a receptacle having a light emitting element or a light receiving element. A holder holding the receptacle and having a plug locking piece, and a housing holding the holder, wherein the holder is provided with an engagement portion that engages with the receptacle. -It is composed of two or more divided bodies that can be combined, and the housing and each of the divided bodies are formed with engaging portions that engage with each other in a state of being combined into a holder. [0006] At least two divided bodies constituting a holder in a separated state are engaged with a receptacle to be combined to form a holder.
Next, by pressing the housing against the holder from above, the housing is engaged with the holder with one touch. In this state, the optical module is completed. An embodiment of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is an exploded perspective view of the optical module of the present invention, FIG. 2 is a perspective view in the middle of assembly, FIG.
4 is a sectional view taken along line AA in FIG. 3, and FIG. 5 is a sectional view taken along line BB in FIG. 3. FIG. 4 shows a state in which a plug is inserted. An optical module according to the present invention comprises a receptacle 1 having a light emitting element or a light receiving element, a holder 2 for holding the receptacle 1, and a housing 4 for holding the holder 2. As shown in FIG. 4, the receptacle 1 has a light emitting element 5 composed of a hermetically sealed laser diode (LD), a lens 6 mounted in front of the light emitting element 5, and holds the lens 6. It comprises a lens holder 7, an outer sleeve 8 surrounding the lens holder 7, and a ferrule bush 9 attached to the front of the lens holder 7. In addition, the light emitting element 5 is not limited to a laser diode and may be another LED (Light Emitting).
Diode), light emitting element such as SLED (super light emitting diode), or Pin-PD (Photodiode), APD
(Avalanche photodiodo) or the like. As shown in FIG. 1 and FIG. 4, two engaging grooves 8a of a predetermined length are formed on the outer peripheral portion of the outer sleeve 8 of the receptacle 1 at two opposing circumferential positions. ing. Here, the assembly of the receptacle 1 is performed, for example, after fixing the lens 6 to the lens holder 7 with low-melting glass, and perpendicularly to the optical axis so that the light emitted from the light emitting element 5 is aligned with the center of the lens 6. The light emitting element 5 and the lens holder 7 are resistance-welded by performing alignment in the XY plane directions. At this time, the positional relationship between the lens 6 and the light emitting element 5 in the Z-axis direction (optical axis direction) is determined by a distance such that a condensed spot comes to the ferrule stopper position 9a of the ferrule bush 9 in an optical coupling experiment by a bench test in advance. Is adjusted, and adjustment is performed using a spacer corresponding to this distance. After the light emitting element 5 and the lens 6 are mounted on the lens holder 7 in this manner, the ferrule bush 9 is mounted. This mounting adjustment is performed by mounting an optical fiber for monitoring the light amount on the ferrule bush 9 and the lens holder 7 together. Set it on the alignment device. Then, the light emitting element 5 is turned on, alignment is performed in the XY plane direction perpendicular to the optical axis so that the coupling light amount of the optical fiber is maximized, and the joint surface between the lens holder 7 and the ferrule bush 9 is fixed by YAG laser spot welding. I do. The holder 2 is composed of a pair of divided bodies 3, 3, and each of the divided bodies 3, 3 and the housing 4 are formed by injection molding using a resin material obtained by mixing inorganic filler in polybutylene terephthalate (PBT). Is molded.
As shown in FIGS. 1 and 4, the divided body 3 is formed by joining a holder body 11 having a pair of engagement protrusions 11a, 11a and an inner member 12 having a plug locking piece 12a and an arc portion 12b. The receptacle 1 is integrally held by the engaging projection 11a. That is, when the receptacle 1 is sandwiched between the pair of divided bodies 3, 3, the engaging projections 11a, 11a of the divided bodies 3, 3 facing each other are arranged on a straight line and together with the outer body. It enters the engagement groove 8 a of the sleeve 8 and holds the receptacle 1. That is, the length of one engagement projection 11a is about half the length of the engagement groove 8a. Further, the arc portions 12b, 1
2b holds the outer periphery of the ferrule bush 9, and the plug locking piece 12a holds the plug 3 as shown in FIG.
When the ferrule 32 into which the zero optical fiber 31 is inserted is fitted into the bush 9, the ferrule 32 elastically engages with the locking groove 33 formed in the plug 30. A pair of concave and convex engaging portions 11b, 11b are formed on the outer end of the holder body 11, respectively. The concave / convex engaging portion 11b has a tapered surface t at its upper surface, and engages with an engaging claw 4a, which is a concave / convex engaging portion of the housing 4, as described later. By the way, the pair of divided bodies 3, 3 are respectively provided with engaging projections 11a, 11a and plug locking pieces 12a, 1a.
Although 2a is provided, it is also possible to provide both engagement protrusions 11a, 11a or plug locking pieces 12a, 12a on one divided body 3 on one side. However, by providing them separately, the two divided bodies 3 and 3 having the same form can be used, and the production of the divided bodies is reduced. On the other hand, the internal shape of the housing 4 is formed in accordance with, for example, a designated size of an F04 type fiber connector (so-called SC type connector) according to JIS C 5973 standard. At the lower four corners of the housing 4, the engagement claws 4 a having a substantially U-shape as viewed from the width direction are formed as described above, and the lower ends of the engagement claws 4 a and 4 a facing each other in the width direction are outside. It expands elastically. That is, as shown in FIG. 5, when the engaging claw 4a is pressed toward the tapered surface t of the engaging protrusion 11a of the holder main body 11, the lower end of the engaging claw 4a moves outward along the tapered surface t. After spreading, it is elastically closed and fixed. In order to assemble the optical module as described above, first, as shown in FIG. 2, the receptacle 1 is sandwiched between the pair of divided bodies 3 and 3, and the engaging protrusion 8 of the holder body 11 is inserted into the engaging groove 8a of the outer sleeve 8. 11a is engaged. Thereafter, when the high housing 4 is put on and pressed down from above, the engaging claw 4a is elastically fitted into the concave-convex engaging portion 11b, and FIG.
Assembled as follows. During this time, there is no work of tightening screws or the like in all the assembling, and the assembling can be performed easily. As described above, in the optical module according to the present invention, the holder is constituted by a divided body which can be divided and combined, and the divided body is provided with an engaging portion to form an engaging part formed on the receptacle. The holder is held by engaging the housing with the divided body united, so that the cost of threading etc. is not required, and the shape of parts is simplified. And at the same time, simplification of the assembling work is achieved. Incidentally, the holder was mounted on the receptacle, and the plug of the F04 type fiber connector specified in JIS C 5973 was repeatedly attached and detached, and the reproducibility of the optical connection state was confirmed. The variation width (full width) is 0.22 dB for a GI-50 fiber plug having a core diameter of 50 μm, and 0.4 for a single mode fiber (SMF) plug having a core diameter of 9 μm.
It was 5 dB. Therefore, the optical coupling situation is also satisfactory.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of an optical module according to the present invention. FIG. 2 is a perspective view of the optical module in the course of assembling. FIG. 5 is a sectional view taken along the line BB in FIG. 3. [Description of References] 1 ... optical module, 2 ... holder, 3 ... divided body, 4 ... housing, 4a ... engaging claw, 5 ... optical element, 8a ... engaging groove,
11a: engagement protrusion, 11b: concave-convex engagement portion, 12a: plug locking piece.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 6/36-6/42

Claims (1)

(57) [Claim 1] In an optical module into which a plug having an optical fiber is inserted, the optical module holds a receptacle having a light emitting element or a light receiving element, and holds the receptacle. It comprises a holder provided with a plug locking piece and a housing for holding the holder. The holder is composed of two or more divided bodies.
At least one of the divided bodies and the receptacle have an engaging portion that engages with each other, and the housing and each of the divided bodies have an engaging portion that engages with each other in a state of being combined into a holder. An optical module, comprising: