JPH0395509A - Connector type optical module - Google Patents

Abstract

PURPOSE:To securely hold a spherical lens at low cost without spoiling the lens performance by pressing and supporting the spherical lens on a lens holder with an elastic member. CONSTITUTION:The projection part 22 of the lens holder 2 is inserted into the end part 11 of an optical connector receptacle 1 to fix a protruded part 23 and an element holder 5 is fitted and fixed onto the outer periphery of the end part 11. Then, the spherical lens 3 is pressed by the hole 41 of a star type leaf spring 4 from below and the terminal of the branch part 42 of the spring 4 is fixed by being clamped between the annular projection part 9 on the internal wall of the element holder 5 and the protruded part 23 of the lens holder 23. Consequently, the spherical lens 3 is never broken when fixed and even if the lens is stained with an adhesive, the coupling efficiency does not deteriorate. No adhesive is used, so the process is simplified and the production efficiency is improved.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a connector type optical module.

More specifically, a connector type that includes a ball lens and an optical connector receptacle that are integrated with an optical element that is a light receiving element or a light emitting element, and that can be optically efficiently coupled to an optical fiber equipped with an optical connector plug. Regarding optical modules.

Conventional technology When connecting an optical fiber and an optical element, a connector-type optical module is used in which the optical element is integrated with an optical connector receptacle and an optical component, and the optical element is connected to an optical fiber equipped with an optical connector plug. . In this case, the above optical components are designed so that the light emitted from the light emitting element enters the optical fiber without spreading, and conversely, the light emitted from the optical fiber enters the light receiving element without spreading. It functions to optically and efficiently couple the fiber and the optical element.

Although various lenses and lens groups are used as the above-mentioned optical components, ball lenses are often used. A conventional connector-type optical module using a ball lens is shown in FIGS. 2 and 3. FIGS. 2 and 3 are longitudinal sectional views of a conventional connector type optical module using a ball lens.

The connector-type optical module shown in FIG. 2 includes a lens holder 2 fixed to the inner wall of the end 11 of the optical connector receptacle 1 on which the optical connector plug is not fitted, and a It includes an element holder 5 having a substantially cylindrical diameter fixed to the outer wall of a certain end, and an optical element 6 fixed to the element holder 5 with a filler 7. The lens holder 2 has a circular horizontal cross section, has a concentric inner hole 21, and holds a spherical lens 3 at a lower end 20. Due to this structure, the diameter of at least the lower end 20 of the inner hole 21 is larger than the outer diameter of the ball lens 3. Furthermore, light can pass through the inner hole 21 along the optical center line of the optical connector receptacle 1.

The ball lens 3 is pressed and fixed in the inner hole 21 of the lens holder 2, and the ball lens 3 and the optical element 6 are held so that their optical centers coincide with the optical center of the optical connector receptacle 1. There is. Further, the optical center of the optical fiber coupled to the optical connector receptacle 1 also coincides with the optical center of the optical connector receptacle 1. Transparent glass is sealed near the upper end of the inner hole of the lens holder 2 to prevent dew condensation on the surfaces of the ball lens 3 and the optical element 6, and a space surrounded by the lens holder 2, element holder 5, and optical element 6 is formed. may be hermetically sealed. Furthermore, ball lens 3
The position of is selected so that the optical coupling efficiency between the optical element 6 and the optical fiber coupled to the optical connector receptacle 1 is maximized.

The connector-type optical module shown in FIG. 3 is completely the same as the connector-type optical module shown in FIG. 2, except for the method of fixing the ball lens.

In the connector type optical module shown in Fig. 3, the ball lens 3
is fixed to the inner hole 21 of the lens holder 2 with an adhesive 8. Other methods include using low-melting glass instead of the adhesive 8, or pressing the ball lens 3 into the inner hole 21 of the lens holder 2 and then fixing it by gluing or fusing.

Problems to be Solved by the Invention In a module in which the ball lens 3 is press-fitted into the inner hole 21 of the lens holder 2 and fixed, such as the connector-type optical module shown in FIG. 2, it is difficult to simply fix the ball lens 3 firmly. You must be able to press the lens without damaging it. Therefore, it was necessary to process the lens and lens holder with high precision, resulting in high component costs and an expensive module as a whole. In addition, in a module such as the connector-type optical module shown in FIG. 3, in which the ball lens 3 is fixed to the inner hole 21 of the lens holder 2 with adhesive or low-melting glass 8, especially when the lens diameter is small, adhesive or other may become too large and cover optically functional parts. Therefore, the optical characteristics of the lens are impaired, and the coupling efficiency between the optical fiber and the optical element is reduced. On the other hand, if there is too little adhesive or the like, the fixing strength of the lens will be reduced, making it impossible to maintain the lens in an appropriate position.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a connector-type optical module that solves the above-mentioned problems of the prior art and that holds a ball lens reliably at a low cost without impairing the performance of the lens.

Means for Solving the Problems According to the present invention, there is provided an optical connector receptacle to which an optical fiber including an optical connector plug can be connected, an optical element,
An element holder that holds the optical element, a ball lens that efficiently performs optical coupling with the optical element when the optical fiber is connected, and a fixing means that holds the ball lens in a predetermined position. In the connector type optical module, the fixing means includes an elastic member and a ball lens mounting member having a shape that does not inhibit the function of the ball lens, and the ball lens is mounted on the ball lens by the elastic member. A connector-type optical module is provided that is pressed and supported by a mounting member.

In the connector type optical module of the present invention, the ball lens fixing means includes an elastic member and a ball lens mounting member, and the ball lens is pressed and supported by the ball lens mounting member by the elastic member. There are main characteristics. That is, in the connector-type optical module of the present invention, the ball lens is not press-fitted into the inner hole of the lens holder, or bonded or fused, but is attached to the ball of the lens holder by an elastic member such as a leaf spring or a coil spring. It can be configured to be pressed and fixed to the lens mounting member.

In the connector type optical module of the present invention having the above structure, the ball lens mounting member must be processed so that at least a portion of the ball lens protrudes and can be suppressed by the elastic member. Further, the elastic member may have any shape as long as it can securely fix the ball lens and ensure an optical path for light passing through the ball lens. Further, the arrangement of the elastic members can be arbitrarily performed.

For example, if the diameter of the upper base is smaller than the diameter of the spherical lens,
A spherical lens is mounted on the upper end of a truncated conical coil spring whose bottom diameter is approximately equal to the inner diameter of the element holder, the lower end is fixed to the inner wall of the element holder, and the spherical lens is attached to the lower end of the inner hole of the lens holder. It can be pressed and moved from place to place.

In addition, two rectangular leaf springs that are sufficiently longer than the diameter of the ball lens and shorter than the inner diameter of the element holder are arranged parallel to each other across the center line of the connector type optical module with an interval slightly narrower than the diameter of the ball lens. It is possible to fix both ends and shift the ball lens near the center by pressing it against the lower end of the inner hole of the lens holder from below.

Furthermore, a plurality of rectangular leaf springs that are slightly shorter than the inner radius of the element holder are arranged isotropically on the radius of the element holder, and the ball lens is lowered into the lower end of the inner hole of the lens holder at the end on the center side. An arrangement in which pressure is applied from the side is also possible.

However, in the connector-type optical module of the present invention, it is preferable that the elastic member has a hole in the center, the inner diameter of which is slightly smaller than the outer diameter of the spherical lens, and a plurality of integrally shaped branch portions of equal length form the hole. This is a star-shaped leaf spring that extends radially isotropically from the periphery of the connector-type optical module and has an overall diameter approximately equal to the inner diameter of the portion of the connector-type optical module where the ball lens is placed. This star-shaped leaf spring is preferable because it can press the ball lens with just one and stably fixes the ball lens.

Moreover, when compared with a coil spring, the dimension in the downward direction can be reduced, which is advantageous for mounting.

When using the star-shaped leaf spring described above, it is preferable to fix the end of each branch and use the hole to press the ball lens against the lower end of the inner hole of the lens holder from below. It is preferable that the inner diameter of the hole in the star-shaped leaf spring is smaller than the outer diameter of the spherical lens, and large enough not to obstruct the light passing therethrough.

When using each of the above-mentioned springs, the method of fixing the end portions can be arbitrarily selected such as caulking, brazing, and soldering. However, especially when using the above-mentioned star-shaped leaf spring, for example, a protrusion is provided inside the element holder so as to come into contact with the lens holder, and this protrusion and the lens holder are connected to the branch of the star-shaped leaf spring. It is advantageous in terms of production efficiency to sandwich the ends of the two.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the following disclosure is merely an example of the present invention and does not limit the technical scope of the present invention in any way.

Embodiment 1 FIGS. 1(a) and 1(b) show an example of a connector type optical module of the present invention. FIG. 1(a) is a longitudinal sectional view, and FIG. 1(b) is an exploded parts arrangement view. Further, FIG. 1(C) shows a perspective view of a star-shaped leaf spring used in the connector type optical module shown in FIGS. 1(a) and (5).

In the connector type optical module of the present invention, the protrusion 22 of the lens holder 2 is inserted into the end 11 of the optical connector receptacle 1 on the side to which the optical connector plug is not connected, and the protrusion 23 is brought into contact with and fixed. . The protruding portion 22 of the lens holder 2 is approximately equal to the inner diameter of the end portion 11, and the projecting portion 23 is approximately equal to the outer diameter of the end portion 1.

Further, the upper end 51 of the element holder 5, which has an inner diameter approximately equal to the outer diameter of the end 12, is connected to the end 11 of the optical connector receptacle l.
It is covered and fixed. The element holder 5 has an annular protrusion 9 on its inner wall that comes into contact with the protrusion 23 of the lens holder 2 in this state. The end of the branch portion 42 of the star-shaped plate spring 4 that presses the ball lens 3 against the lens holder 2 is sandwiched between the protrusion portion 9 and the protrusion portion 23 of the lens holder 2 and is fixed. An optical element 6 is inserted into the lower end 52 of the element holder 5 and fixed with a filler 7.

In the connector-type optical module of the present invention, the lens holder 2 has the protruding portion 23 having an outer diameter approximately equal to the outer diameter of the end portion 11 of the optical connector receptacle 1, as described above. A concentric protrusion 22 having an outer diameter approximately equal to the inner diameter of the end portion 11 protrudes from the center of the overhang 23 . Furthermore, a concentric inner hole 21 also passes through the lens holder 2.

The diameter of the inner hole 21 is sufficiently large for the light beam passing through it,
Moreover, it is smaller than the diameter of the ball lens 3. Further, the opening 20 of the inner hole 21 on the side of the projecting portion 23 is chamfered so that the ball lens 3 is stably mounted.

Such a lens holder 2 is fixed such that the optical center of the optical connector receptacle 1, its own optical center, and the optical center of the ball lens 3 mounted thereon coincide with each other.

In this embodiment, the star-shaped leaf spring 4 has four branches 42,
The diameter of the central hole 41 is smaller than the diameter of the ball lens 3, and is large enough not to obstruct the light rays passing through the ball lens 3. Further, the overall outer diameter is approximately equal to the inner diameter of the upper end 51 of the element holder 5.

This star-shaped leaf spring 4 is connected to the projecting portion 23 of the lens holder 2.
The ball lens 3 mounted in the opening 20 of the inner hole 21 of the hole 4
1 from below, and the end of the branch portion 42 is sandwiched between the annular protrusion 9 provided on the inner wall of the element holder 5 and the protruding portion 23 of the lens holder 2, thereby being fixed.

The element holder 5 has a substantially cylindrical shape, the inner diameter of the upper end 51 is equal to the outer diameter 11 of the end 1l of the optical connector receptacle 1, and the above-mentioned annular protrusion 9 is provided on the inner wall.

This protruding part 9 does not necessarily have to be continuous in an annular shape, but can be shaped so that the end part of each branch part 42 of the star-shaped leaf spring 4 can be sandwiched and fixed between the protruding part 23 of the lens holder 2. It may be formed continuously.

Further, an optical element 6 is fixed to the lower end 52 of the element holder 5 so that its optical center coincides with the optical center of the ball lens 3. It is preferable that the inner diameter of the lower end 52 of the element holder 5 is slightly larger than the outer diameter of the optical element 6 so that the optical element 6 can be inserted with a small force without being damaged.

In the connector-type optical module of the present invention having the above-described structure, the ball lens 3 is fixed to the lens holder 2 by only being pressed by the plate spring 4. Therefore, the production process is simpler than in conventional connector-type optical modules in which the ball lens is compressed into a lens holder or fused with adhesive, low-melting glass, or the like. Further, since the ball lens is not damaged or contaminated, the yield is also increased.

12. Effects of the Invention As explained above, in the connector type optical module of the present invention, the ball lens fixing means includes an elastic member and a ball lens mounting member, and the ball lens is pressed against the ball lens mounting portion by the elastic member. It is fixed.

Therefore, the ball lens will not be damaged or soiled during fixation, which will not degrade the coupling efficiency.

In addition, the production process becomes simpler and production efficiency improves.

[Brief explanation of drawings]

FIG. 1(a) is a longitudinal sectional view of a connector type optical module of the present invention, FIG. 1(b) is an exploded assembly view of the connector type optical module of FIG. 1(a), and FIG. FIG. 1(C) is a perspective view of a star-shaped leaf spring used in the connector-type optical module of FIGS. 1(a) and (b), and FIGS. 2 and 3 are a perspective view of a conventional connector-type optical module. FIG. [Main reference numbers] ■... Optical connector receptacle, 2... Lens holder, 3... Ball lens, 4... Star-shaped plate blade, 5... Element holder, 6...
・Optical element, 7... Filler, 8... Adhesive

Claims (1)

[Claims] An optical connector receptacle to which an optical fiber can be connected is provided with an optical connector plug, an optical element, an element holder for holding the optical element, and an optical coupling with the optical element when the optical fiber is connected. In a connector-type optical module integrally comprising a ball lens for efficient operation and a fixing means for holding the ball lens in a predetermined position, the fixing means is an elastic member having a shape that does not inhibit the function of the ball lens. and a ball lens mounting member, wherein the ball lens is pressed and supported by the ball lens mounting member by the elastic member.