JP2000171735A - Optical transmission module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and precisely conduct positioning and fixing operations of optical parts which make up an optical transmission module that is used to connect information processing terminals to an optical communication network. SOLUTION: Left and right positions of a rectangular prism 81, which is used to switch optical paths of an optical transmission module, are adjusted by a pair of adjustment horizontal screws 89d and 89e so as to adjust the distance between axes of an input light taking in section 3 and an output light transmitting section 7. Then, the top and the bottom positions of the optical axis and the tilt in the up and down direction are adjusted by using a horizontal eccentricity pin 38 of the section 3 and a pair of adjustment vertical screws 39a and 39b. The tilt in the left and right direction of the optical axis is adjusted by using a pair of adjustment horizontal screws 79a and 79b of an output light beams transmitting section 7 so as to match these optical axes. Then, the horizontal and vertical adjustment screws are fixed to the side of a base table of the optical transmission module by an adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission module used for connecting an information processing terminal such as a personal computer to an optical communication network for transmitting information via an optical fiber cable. More specifically,
The present invention relates to an optical axis adjusting mechanism of such an optical transmission module.

[0002]

2. Description of the Related Art In an optical communication network constituted by optical fiber cables, for example, in an optical LAN system, an optical signal transmitted through an optical fiber cable is converted into an electric signal through an optical transmission module, and information is converted. The data is taken into a personal computer as a processing terminal. In addition, information generated by a personal computer is converted from an electric signal to an optical signal via an optical transmission module, and transmitted to another terminal via an optical fiber cable.

FIG. 7 shows an outline of a typical conventional optical LAN system. As shown in FIG.
The system 101 includes an optical fiber cable 102 (n)
(N: 1, 2,...) And a personal computer PC (n) connected in series between each optical fiber cable via an optical transmission module (photoelectric conversion module) 103 (n). I have. Each optical transmission module 103 (n) includes, on its optical input side, a photodiode 105 as a light receiving unit that generates an electric signal corresponding to input light, and its optical output side converts an electric signal into an optical signal. A laser diode 6 is provided as a light emitting unit for conversion.

Here, in the optical transmission module, the optical axes of the respective optical components are adjusted, and then the respective optical components are fixed. Generally, each optical component is movably attached to the base of the optical transmission module, and then
The optical axis of each optical component is adjusted, and thereafter, each optical component is fixed with a fixing ring or an adhesive. When a fixing ring is used, the optical component is sandwiched between the fixing rings and fixed by spot welding or the like. However, when an adhesive is used, the optical component can be directly fixed to the base of the optical transmission module, so that the operation is simple and the cost is low. For this reason, a method of fixing an optical component with an adhesive has been widely adopted.

[0005]

However, in the fixing method using an adhesive, it is necessary to hold the optical component so that it does not deviate from the adjustment position until the adhesive is cured. Is often difficult. Further, when the adhesive is cured, a change with time such as shrinkage occurs. For these reasons, the method of fixing the optical component using the adhesive has a problem that the optical component cannot be fixed at the adjustment position with high accuracy.

In particular, when downsizing an optical transmission module or downsizing a product in which the optical transmission module is incorporated, it is necessary to reduce the size of the optical components, and accordingly, high processing accuracy cannot be expected. . As a result, inevitably, the adjustment of the mounting position of the optical component (optical axis alignment),
In addition, it is necessary to perform the fixing after the adjustment with high accuracy.

[0007] In view of the above, the object of the present invention is to provide:
It is an object of the present invention to provide an optical transmission module including an optical axis adjustment mechanism that can easily and accurately perform optical axis alignment and fixing of optical components.

Another object of the present invention is to propose an optical axis adjusting method for an optical transmission module having the novel optical axis adjusting mechanism.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to an input light receiving section, a light receiving section, a light emitting section, and an output side optical fiber cable connected to an input side optical fiber cable. An output light transmitting section, and the input light capturing section and the light receiving section are disposed so as to face each other so that an optical axis thereof coincides with each other, and the light emitting section and the output light transmitting section are opposed so that their optical axes coincide with each other. In the arranged optical transmission module: a first optical axis adjusting mechanism for adjusting an optical axis of any one of the input light receiving section and the light receiving section, and the light emitting section and the output light transmitting section A second optical axis adjusting mechanism for adjusting one of the optical axes; each of the first and second optical axis adjusting mechanisms uses an eccentric rotation about a vertical axis. To adjust the left and right position of the optical axis A vertical eccentric pin, an adjusting horizontal screw for adjusting the horizontal direction of the optical axis, a horizontal eccentric pin for adjusting the vertical position of the optical axis using eccentric rotation about a horizontal axis, and an optical eccentric pin. A vertical screw for adjustment for adjusting the inclination in the vertical direction.

In the optical transmission module having this configuration, the vertical and horizontal eccentric pins are turned to adjust the vertical and horizontal positions of the optical axis, and the adjustment vertical screw and the adjustment horizontal screw are turned. The tilt of the optical axis in the vertical and horizontal directions is adjusted. The adjusted optical axis position is maintained as long as these eccentric pins and screws are not turned. After the optical axis adjustment, adjust the vertical screw,
The adjustment horizontal screw may be fixed to the base of the optical transmission module by an adhesive. Since the position of the optical axis is defined by the eccentric pin and the screw, a temporal change such as shrinkage during curing of the adhesive does not directly affect the position of the optical axis. Therefore, according to the present invention, the optical axis of the optical component can be aligned with a simple operation, and the optical component can be accurately fixed at the adjusted position.

Here, to enable optical communication via the optical transmission module regardless of the on / off state of the information processing terminal connected to the light receiving section and the light emitting section of the optical transmission module. It is preferable that the light receiving unit and the light emitting unit connected to the information processing terminal can be bypassed as follows.

That is, the optical transmission module having the above configuration further includes an optical path switching means including an optical path switching optical element and a drive mechanism for moving the optical path switching optical element to the optical path switching position and the retracted position. ;
The optical path switching optical element is interposed, the input light capturing and output light transmitting sections are arranged on one side, and the light receiving section and the light emitting section are arranged on the other side; While in the retracted position, the light receiving section is irradiated with the input light emitted from the input light capturing section, and the output light emitting section is irradiated with the output light emitted from the light emitting section; When the element moves to the optical path switching position, the light emitted from the input light capturing unit may be guided to the output side transmitting unit by the optical path switching optical element without irradiating the light receiving unit. .

The optical path switching optical element includes a pair of reflecting surfaces inclined at 45 degrees with respect to the optical axis of the input light taking-in section and the optical axis of the output light sending section at the optical path switching position. It can be. A typical optical path switching optical element is a right angle prism.

In this case, in order to perform the position adjustment and the fixing operation of the optical path switching optical element simply and accurately, the optical path with respect to the optical axis of the input light taking-in section and the output light sending section is required. It is desirable to arrange a position adjustment mechanism for adjusting the position of the switching optical element in the left-right direction. The position adjusting mechanism may be provided with an adjusting horizontal screw for adjusting the position of the optical path switching optical element in the left-right direction with respect to the optical axes of the input light taking-in section and the output light sending-out section.

Also in this position adjusting mechanism, the adjusting horizontal screw may be fixed with an adhesive after the position adjustment. Also in this case, since the optical element is not directly fixed by the adhesive, it is possible to suppress such a problem that the adjusted position is shifted due to a temporal change such as shrinkage due to the curing of the adhesive.

Next, in an optical transmission module provided with an optical path switching optical element, an input light take-in section, a light receiving section, a light emitting section, an output light transmitting section, and an optical axis adjustment between the optical path switching optical elements. Is required. For this purpose, the following configuration is desirable. That is, the optical transmission module includes: the first optical axis adjusting mechanism for adjusting the optical axis of the light receiving unit; the second optical axis adjusting mechanism for adjusting the optical axis of the light emitting unit; A third optical axis adjusting mechanism for adjusting the optical axis of the input light capturing unit; and a fourth optical axis adjusting mechanism for adjusting the optical axis of the output light transmitting unit; One of the fourth optical axis adjustment mechanisms is a horizontal eccentric pin that adjusts the vertical position of the optical axis by using eccentric rotation about a horizontal axis, and an adjustment pin that adjusts the vertical tilt of the optical axis. A vertical screw; the other of the third and fourth optical axis adjusting mechanisms is provided with an adjusting horizontal screw for adjusting the inclination of the optical axis in the left-right direction.

In the optical transmission module having this configuration, the optical axis can be adjusted in the following procedure. First, by adjusting the horizontal position of the optical path switching optical element using an adjustment horizontal screw of the position adjustment mechanism, the inter-axis dimension of the optical axis of the input light capturing unit and the output light transmitting unit is adjusted. adjust. Next, using the adjusting vertical screw and the adjusting horizontal screw of the third and fourth optical axis adjusting mechanisms, between the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit, Adjust the vertical tilt and the horizontal tilt.
Thereafter, the horizontal positions of the third and fourth optical axis adjusting mechanisms are used to adjust the vertical position of the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit. Thereafter, the optical axis of the light receiving section is adjusted to the optical axis of the input light receiving section by the first optical axis adjusting mechanism. Similarly, the optical axis of the light emitting unit is adjusted to the optical axis of the output light transmitting unit by the second optical axis adjusting mechanism. Finally, the adjustment horizontal screw of the position adjustment mechanism and the adjustment horizontal screw and the adjustment vertical screw of each optical axis adjustment mechanism are bonded and fixed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical transmission module according to the present invention will be described below with reference to the drawings.

(Basic Configuration of Optical Transmission Module) FIG. 1 is an explanatory diagram showing a basic configuration of an optical transmission module 1 of the present embodiment. As shown in this figure, the optical transmission module 1 of the present example
Are connected to the input light capturing unit 3 connected to the input side optical fiber cable 2, the light receiving unit 4 connected to the input side of the information processing terminal PC (n), and the output side of the information processing terminal PC (n). Light emitting section 5 and output side optical fiber cable 6
, And an optical path switching unit 8. The optical path switching means 8 includes a right-angle prism 81 as an optical element for switching the optical path, and a drive mechanism 82 for moving the right-angle prism 81 to an optical path switching position and a retreat position as described later.

The input light receiving section 3 and the light receiving section 4 are opposed to each other so as to have a fixed interval so that their optical axes coincide with each other. Similarly, the light emitting section 5 and the output light transmitting section 7 are also fixed at a constant interval. Is opened so that both optical axes coincide with each other. Further, the input light taking-in unit 3 and the output light sending-out unit 7 are arranged on one side, and the light receiving unit 4 and the light emitting unit 5 are arranged on the other side with the right-angle prism 81 interposed therebetween.

Here, an input-side optical path Lin from the input light receiving section 3 to the light receiving section 4 and an output light transmitting section 7 from the light emitting section 5.
, And the output side optical path Lout. A pair of orthogonal side surfaces of the right-angle prism 81 are reflection surfaces 81a and 81b. Of these reflecting surfaces, one reflecting surface 81a is connected to the input side optical path Lin by four.
The other reflection surface 81b is inclined by 5 degrees, and the output side optical path Lout
The light irradiating the reflection surface 81a on the incident side is reflected by the reflection surface 81a at right angles toward the reflection surface 81b on the opposite side.

In the optical transmission module 1 having this configuration, while the right-angle bristles 81 are in the retracted position, as described later, the input light taken in from the input light take-in unit 3 is applied to the light-receiving unit 4 and the light-emitting unit 5 is used. The output light emitted from is output to the output light transmission unit 7. On the other hand, when the right-angle prism 81 moves to the optical path switching position, the light taken in from the input light taking-in unit 3 is transmitted to the pair of reflecting surfaces 81.
The path is bent at a right angle at a and 81b. Therefore, the light is directly guided to the output side sending unit 7 without reaching the light receiving unit 4.

In an optical transmission system in which the optical transmission module 1 of this embodiment is used in place of the optical transmission module 103 (n) in FIG. 7 showing a conventional example, the power of the personal computer terminal PC (n) is turned off. When the right-angle prism 81 is moved to the optical path switching position in conjunction with the
An optical communication network bypassing (n) is configured. Therefore,
Optical transmission can always be performed irrespective of whether the terminal PC (n) is on or off.

(Specific Configuration) Next, a specific configuration of the optical transmission module 1 of the present embodiment will be described with reference to FIGS.

First, FIG. 2 is a longitudinal sectional view of the optical transmission module 1 of the present embodiment, FIG. 3 (A) is a sectional view taken along the line 3A-3A, and FIG. 3 (B) is FIG. 3 (A). 2A is a side view when viewed from the direction of arrow A, and FIG.
FIG. 4B is a cross-sectional view of a portion cut along line 4A, and FIG. 4B is a cross-sectional view of a portion cut along line 4B-4B in FIG.
As shown in these drawings, the light transmission module 1 includes a housing 11 having a rectangular parallelepiped outer shape, and the housing 11 includes a base 12 and a cover plate 13 covering the base 12. ing. The base 12 includes a bottom wall portion 14 having a rectangular planar shape, vertical side wall portions 15 and 16 formed on both sides thereof, a vertical front wall portion 17 formed before and after the bottom wall portion 14 and a vertical And a rear wall portion 18. The cover plate 13 is attached and fixed to the base 12 in a state of being bridged over the upper surfaces of the side wall portions 13 and 14 on both sides.

The height of the front wall portion 17 of the base 12 is lower than the side wall portions 13 and 14 except for the central partition wall 17a, so that the front wall 11f of the housing 11 sandwiches the partition wall 17a. One opening is formed. Rear wall part 1
Since the height of 8 is lower than the side wall portions 13 and 14 as a whole, one horizontally long opening is formed in the rear surface 11r of the housing 11.

In two openings of the front surface 11f of the housing,
The input light taking-in unit 3 and the output light sending-out unit 7 are respectively mounted. The light receiving unit 4 and the light emitting unit 5 are mounted in the opening on the rear surface 11r of the housing in a state where they are arranged in parallel. An optical path switching means 8 including a right-angle prism 81 and a driving mechanism 82 is disposed inside the housing 11. The structure of each part described above will be described in more detail.

(Input Light Intake Unit 3) The input light intake unit 3 mounted in one opening of the front surface 11f of the housing 11f is mounted in the opening so as to be movable in a vertical plane extending in the front-rear direction of the housing. The supporting block 31 is provided. A ferrule 32 is inserted and fixed from the front surface of the support block 31 toward the rear of the housing. The input end optical fiber cable 2 is connected to the front end of the ferrule 32. A circular hole 33 coaxial with the ferrule 32 and having a larger diameter than the ferrule 32 is formed from the rear surface of the support block 31 toward the front of the housing, and a mirror provided with a collimating lens 34 at the front end is formed in the circular hole 33. A tube 35 is inserted in the housing so that it can slide in the front-rear direction. The rear end portion of the lens barrel 35 protrudes from the support block 31, and a nut 36 is fastened to a male screw portion formed at the projecting portion. , That is, the lens position can be adjusted.

The input light capturing unit 3 further includes an optical axis 3a.
An optical axis adjustment mechanism for adjusting the height position (up and down position) and the inclination angle (vertical inclination) in the vertical plane is provided. And a tilt angle of the support block 31 by rotating the support block 31 about the horizontal eccentric pin 38 in a vertical plane extending in the housing front-rear direction. And vertical adjusting screws 39a and 39b for adjusting the distance.

The horizontal eccentric pin 38 for adjusting the height position has coaxial shaft portions 38a, 38 rotatably supported by the housing side wall portion 15 and the partition wall 17a.
b, and an eccentric shaft 38c formed therebetween. The eccentric shaft 38c is rotatably inserted into the support block 31 to support the support block 31. I have. This horizontal eccentric pin 3 for height adjustment
The grooved head 38d of 8 is exposed to the outside from the housing side wall portion 15.

On the other hand, a pair of adjustment vertical screws 39a, 39
b is screwed vertically to the support block 31 at a position in the front-rear direction of the housing with the horizontal eccentric pin 38 for height position adjustment interposed therebetween. Adjustment vertical screws 39a, 3
9b is a stepped surface 1 formed on the front wall 17 of the housing.
7b, and the head of each screw is a support block 31.
It is exposed from the upper surface.

When the horizontal eccentric pin 38 for height adjustment is turned,
The eccentric shaft portion 38c rotates eccentrically, and with this eccentric rotation, the support block 31 supported by the eccentric shaft portion 38c moves up and down within a minute range. Therefore, by turning the horizontal eccentric pin 38 for height adjustment, the height position of the support block 31, in other words, the optical axis 3 of the input light take-in section 3 is adjusted.
The height position of a can be adjusted.

Further, a pair of vertical screws 39 for adjusting the inclination angle is provided.
By adjusting the screwing amounts of a and 39b, the support block 31 can be slightly rotated up and down in a vertical plane extending in the housing front-rear direction around the eccentric shaft 38c of the horizontal eccentric pin 38 for height adjustment. . Therefore, the inclination angle of the support block 31 in the vertical plane, in other words, the optical axis 3a of the input light take-in section 3, is generated by these screws.
Can be adjusted in the vertical plane.

(Output Light Transmitting Unit 7) The front surface 1 of the housing opposite to the input light receiving unit 3 with the partition wall 17a interposed therebetween.
An output light transmitting unit 7 is mounted in an opening formed in f. The output light transmitting unit 7 includes a support block 71 that is rotatably mounted on a vertical line extending in a vertical direction of the housing and is attached to the opening. Support block 71
A ferrule 72 is inserted and fixed from the front surface of the ferrule 72 toward the rear of the housing. An output optical fiber cable 6 is connected to the front end of the ferrule 72.

A circular hole 73 coaxial with the ferrule 72 and having a diameter larger than that of the ferrule 72 is formed from the rear surface of the support block 71 toward the front of the housing, and a collimating lens 74 is attached to the front end of the circular hole 73. The mounted lens barrel 75 is slidably inserted in the front-rear direction of the housing. The rear end portion of the lens barrel 75 protrudes from the support block 71, and a nut 76 is fastened to a male screw portion formed in this portion.
The position of the lens barrel 75 in the front-rear direction, that is, the lens position can be adjusted according to the amount of fastening of the lens 6.

The input light transmitting section 7 is further provided with an optical axis adjusting mechanism capable of adjusting the direction (horizontal inclination) of the optical axis 7a in the horizontal plane, and the optical axis adjusting mechanism includes a support block. A support shaft 78 attached to the bottom surface of 71 and a pair of adjusting screws 79a and 79b are provided. The central axis 78a of the support shaft 78 is a perpendicular line intersecting with the optical axis 7a,
It is rotatably supported by the housing front wall portion 17.

The pair of adjusting horizontal screws 79a and 79b are
The support shaft 78 is interposed therebetween and is arranged in the front-rear direction of the housing, and is horizontally screwed from the outside of the housing side wall 16 to the side wall portion 16. The ends of the legs of the screws 79a and 79b abut the side surface of the support block 71, and the head of each screw is exposed to the outside from the housing side wall portion 16.

By adjusting the screwing amounts of the pair of adjusting horizontal screws 79a and 79b, the support block 71 can be rotated about the support shaft 78 in a horizontal plane. Therefore, with these adjustment horizontal screws, the orientation of the support block 31 in the horizontal plane, in other words, the horizontal orientation of the optical axis 7a of the output light transmitting unit 7 can be adjusted. In addition,
After the orientation is adjusted, the support block 71 is fixed to the housing front wall portion 17 by a pair of fastening bolts 71a and 71b.
Is fastened and fixed.

(Light receiving unit 4) The light receiving unit 4 mounted on the opening of the rear surface 11r of the housing
And an inner support block 42 disposed inside
And a circular hole 42a formed in the inner support block 42.
Photodiode 43 as a light receiving element mounted from the rear end of
And a lens barrel 44 mounted from the front end of the circular hole 42a, and a nut 45 fixing the lens barrel 44 to the support block 42.
And a collimating lens 46 attached to the rear end of the lens barrel 44.

The light receiving section 4 further includes an optical axis 4 of the light receiving section 4.
There is provided an optical axis adjusting mechanism for making a coincide with the optical axis 3a of the input light capturing section 3 described above. The optical axis adjustment mechanism includes a vertical eccentric pin 47 for adjusting the left and right positions of the outer support block 41 by moving the outer support block 41 in the horizontal direction of the housing in the horizontal plane, and a direction (horizontal direction) of the outer support block 41 in the horizontal plane. ), A pair of adjusting horizontal screws 48a, 48b for adjusting the height of the inner support block 42, a horizontal eccentric pin 49 for adjusting the height position (up and down position) of the inner support block 42, and the front and rear of the housing of the inner support block 42. Angle in the vertical plane extending in the vertical direction (vertical tilt)
Adjustment vertical screws 42b and 42c for adjusting
And

The vertical eccentric pin 47 has a shaft portion 47a rotatably inserted from the bottom side of the housing rear wall portion 18 and an eccentric shaft portion 47b inserted into the bottom of the outer support block 41. The grooved head 47c is exposed from the bottom surface of the housing. When the vertical eccentric pin 47 is turned, the eccentric shaft portion 47a supporting the outer support block 41 is eccentrically rotated. Accordingly, the outer support block 41 is accordingly moved in the housing width direction (left and right).
Go to Therefore, the position of the optical axis 4a of the optical system incorporated in the inner support block 42 supported by the outer support block 41 in the left-right direction can be adjusted.

A pair of adjusting horizontal screws 48a, 48
b is located in the front-rear direction of the housing with the vertical eccentric pin 47 interposed therebetween, and by adjusting the amount of screwing, the outer support block 41 can be rotated left and right around the vertical eccentric pin 47 in the horizontal plane. . Therefore, the horizontal direction of the optical axis 4a of the optical system incorporated in the inner support block 42 supported by the outer support block 41 can be adjusted.

Next, in the horizontal eccentric pin 49, the coaxial shaft portions 49a and 49b formed at both ends are rotatably supported by the outer support block 41, and the eccentric shaft portion 49c located therebetween is rotated. The horizontal eccentric pin 4 is inserted through the inner support block 42 in a possible state.
9, the inner support block 42 is connected to the outer support block 4
It is supported on one side. The grooved head 49d of the horizontal eccentric pin 49 can be seen from a circular opening 15a formed in the housing side wall portion 15. This opening 15
When the horizontal eccentric pin 49 is turned from outside using a, the inner support block 42 moves up and down in a vertical plane extending in the front-rear direction of the housing. Therefore, this horizontal eccentric pin 49
By turning, the height position of the optical axis 4a can be adjusted.

Further, a pair of vertical screws for adjustment 42b, 4
2 c is screwed into the inner support block 42 from above at the position in the front-rear direction of the howing with the horizontal eccentric pin 49 interposed therebetween, and the tip of the leg thereof is in contact with the outer support block 41. By adjusting these adjustment vertical screws 42b and 42c, the inclination angle of the optical axis 4a in a vertical plane extending in the front-rear direction of the housing can be adjusted.

After the adjustment of the optical axis position, the outer support block 41 becomes a pair of fastening bolts 41a, 41b.
Thereby, it is fastened and fixed to the base 12 side.

(Light Emitting Unit 5) The light emitting unit 5 arranged adjacent to the light receiving unit 4 has the same basic configuration as the light receiving unit 4.
The difference is that a laser diode as a light emitting element is provided instead of the light receiving photodiode.

That is, the light emitting portion 5 mounted on the opening of the rear surface 11r of the housing is
And an inner support block 52 disposed inside the
And a circular hole 52a formed in the inner support block 52.
A laser diode 53 as a light emitting element mounted from the rear end, a lens barrel 54 mounted from the front end of the circular hole 52a,
A nut 55 for fixing the lens barrel 54 to the inner support block 52 and a collimating lens 56 attached to the rear end of the lens barrel 54 are provided.

The light emitting section 5 further includes an optical axis 5 of the light emitting section 5.
An optical axis adjustment mechanism is provided to make a coincide with the optical axis 7a of the output light transmitting section 7 described above. This mechanism includes a vertical eccentric pin 57 for adjusting the left and right positions of the outer support block 51 by moving the outer support block 51 in the horizontal direction of the housing in a horizontal plane, and a pair of the eccentric pins 57 for adjusting the orientation of the outer support block 51 in the horizontal plane. Adjustment horizontal screws 58a, 5
8b, a horizontal eccentric pin 59 for adjusting the height position of the inner support block 52, and a pair of adjustment vertical screws for adjusting the inclination angle of the inner support block 52 in a vertical plane extending in the front-rear direction of the housing. 52b and 52c.

The vertical eccentric pin 57 has a shaft portion 57a rotatably inserted from the bottom surface side of the housing rear wall portion 18 and an eccentric shaft portion 57b inserted into the bottom of the outer support block 51. The grooved head 57c is exposed from the bottom surface of the housing. When the vertical eccentric pin 57 is turned, the eccentric shaft portion 57a supporting the outer support block 51 rotates eccentrically, and accordingly, the outer support block 51 moves right and left in the width direction of the housing. Therefore, the position in the left-right direction of the optical axis 5a of the optical system incorporated in the inner support block 52 supported by the outer support block 51 can be adjusted.

Further, a pair of adjusting horizontal screws 58a, 58
b is located in the front-rear direction of the housing with the eccentric pin 57 interposed therebetween, and by adjusting the amount of screwing, the outer support block 51 can be rotated left and right about the eccentric pin 57 in a horizontal plane. Therefore, the inner support block 5 supported by the outer support block 51
2, the horizontal direction of the optical axis 5a of the optical system incorporated in the optical system 2 can be adjusted.

Next, the horizontal eccentric pin 59 has the coaxial shaft portions 59a and 59b formed at both ends rotatably supported by the outer support block 51, respectively, and the eccentric shaft portion 59c located therebetween is rotated. The horizontal eccentric pin 5 is inserted through the inner support block 52 in a possible state.
9, the inner support block 52 is connected to the outer support block 5
It is supported on one side. The grooved head 59d of the horizontal eccentric pin 59 can be viewed from a circular opening 16a formed in the housing side wall portion 16. This opening 16
When the horizontal eccentric pin 59 is turned from outside using a, the inner support block 52 moves up and down in a vertical plane extending in the front-rear direction of the housing. Therefore, this horizontal eccentric pin 59
By turning, the height position of the optical axis 5a can be adjusted.

Further, a pair of adjustment vertical screws 52b, 5b
2c is screwed into the inner support block 52 from the upper side at a position in the front-rear direction of the howing with the horizontal eccentric pin 59 interposed therebetween, and the tip of the leg is in contact with the outer support block 51. By adjusting these screws 52b and 52c, the inclination angle of the optical axis 5a in a vertical plane extending in the front-rear direction of the housing can be adjusted.

After the adjustment of the optical axis position is performed, the outer support block 41 is provided with a pair of fastening bolts 41a and 41b.
Thereby, it is fastened and fixed to the base 12 side.

(Optical path switching means 8) The optical path switching means 8 includes a right-angle prism 81 and a drive mechanism 82 for moving the right-angle prism 81 up and down. Right angle prism 8
1 has two orthogonal side surfaces that are reflection surfaces 81a and 81b.
And these reflection surfaces are arranged so as to coincide with the vertical surface. One of the reflection surfaces 81a is connected to the input light capturing unit 3
Is inclined by 45 degrees with respect to the input-side optical path Lin reaching from the light-receiving section 4 to the light-receiving section 4, and the other reflection surface 81 a is inclined in the opposite direction to the output-side optical path Lout from the light emitting section 5 to the output light transmitting section 7.
Degrees.

The right angle prism 81 is mounted on a pair of front and rear prism bases 83a and 83b.
3a and 83b are supported by the drive mechanism 82.

The drive mechanism 82 is formed of an electromagnetic solenoid, and includes a base 84 attached to the housing bottom wall portion 14, a coil 85 attached to the base 84 so as to surround the base 84, It has a plunger 86 with a bottom shape complementary to a centrally formed upwardly raised conical protrusion and a complementary bottom shape. The upper surfaces of the plungers 86 support bism tables 83a and 83b, and the plungers 86 can move up and down along three vertical guide shafts 87a, 87b and 87c.

At the tips of the vertical guide shafts 87a to 87c, large diameter stoppers 88a to 88c are formed, and the plunger 86 is connected to the vertical guide shafts 87a to 87c.
The coil springs 89a to 89c (only the coil spring 89a is shown in the drawing) are urged upward. Therefore, the plunger 86 is normally held at the upper end position regulated by the stoppers 88a to 88c as shown in FIG. A prism base 83a supported by the plunger 86 at this position,
The right-angle prism 81 attached to 83b is held at a height position (light path switching position) where its two reflecting surfaces 81a and 81b intersect the input side optical path Lin and the output side optical path Lout.

In this state, as described with reference to FIG. 1, the optical signal input to the input light receiving section 3 via the input side optical fiber cable 2 is transmitted from the input side optical path L
The light is emitted along in and irradiates one of the reflection surfaces 81a of the right-angle prism 81, where it is reflected at a right angle and then further reflected at the other reflection surface 81b at a right angle. As a result, the input optical signal is directly guided to the output light transmitting unit 7 via the right-angle prism 81, and is transmitted to the output side optical fiber fiber 6 via this.

When the coil 85 is energized, a magnetic circuit is formed from the coil 85 via the plunger 86 and the base 84, and the plunger 86 is provided with coil springs 89a to 89a.
It is sucked downward against the spring force of 9c. As a result, the plunger 86 descends to the lower end position along the vertical guide shafts 87a to 87c, and the two reflecting surfaces 81a and 81b of the right-angle prism 81 attached to the prism bases 83a and 83b thereon are input. Side light path Li
n and to the retracted position retracted below the output side optical path Lout.

As a result, the input side optical fiber cable 2
The optical signal input to the input light capturing unit 3 via the input light capturing unit 3 is emitted from the input light capturing unit 3 along the input side optical path Lin, and the photodiode 43 of the light receiving unit 4 on the rear surface side of the housing.
Is irradiated. An electric signal obtained by photoelectric conversion according to light reception in the photodiode 43 is supplied to a terminal such as a personal computer. When an electric signal is supplied to the light emitting unit 5 from the terminal side, a corresponding optical signal is output by the laser diode 53. The output optical signal is emitted along the output-side optical path Lout, passes through the output-light transmission unit 7, and is output from the output-side optical fiber cable 6.
Is transmitted to

Here, in this example, the right angle prism 8
1 is provided with a position adjusting mechanism for adjusting the position in the width direction of the housing. The position adjustment mechanism guides the front prism base 83a on the upper surface of the plunger 86 in the width direction of the housing to form a guide surface 86a formed on the upper surface of the plunger and a guide surface formed on the front end surface of the rear prism base 83b. 83c. Further, a pair of horizontal adjusting screws 89d and 89e for moving the prism base 83a in the width direction of the housing are provided. A pair of horizontal screws 89d and 89e are screwed into both side walls of the plunger 86, and their leg ends are connected to the prism base 83.
Abut on both sides. The heads of these screws 89d and 89e can face through circular holes 15b and 16b (only the circular hole 15b is shown in the figure) formed in the housing side wall portions 15 and 16. By adjusting the amount of tightening of the pair of adjustment horizontal screws, the position of the right-angle prism 81 in the housing width direction can be adjusted.

(Optical Axis Adjustment Operation) Next, with reference to FIGS. 5 and 6, an operation procedure for aligning the optical axes of the respective optical elements in the optical transmission module 1 having the above configuration will be described. The outline of the adjustment procedure is as follows. As a premise of the optical axis adjustment, the lenses 34, 46, 56,
The position of 74 is adjusted, these are attached to the lens barrel with an adhesive, and the adhesive is sufficiently cured.

First, an optical axis adjustment between the input light taking-in unit 3, the right-angle prism 81, and the output light sending-out unit 7 is performed. next,
The optical axis of the light receiving section 4 is adjusted to match the optical axis of the fixed input light capturing section 3. Similarly, the optical axis of the light emitting unit 5 is adjusted to match the optical axis of the fixed output light transmitting unit 7.
Finally, the right-angle prism 81 is moved to the retracted position and the optical path switching position, and it is confirmed that the optical axis deviation is within an allowable range in both circuits, and a predetermined portion is fixed with an adhesive.

Next, referring to FIG.
The operation of adjusting the optical axis of the short circuit from the input light taking-in unit 3 to the output light sending-out unit 7 will be described in detail. The optical axis 3a of the input light receiving section 3 and the optical axis 7 of the output light transmitting section 7
The distance from a, i.e., the deviation between the axes, is adjusted by moving the right-angle prism 81 left and right (in the width direction of the housing) using a pair of horizontal adjusting screws 89d and 89e.

Here, if the perpendicularity of the two reflecting surfaces 81a and 81b of the right-angle prism 81 is maintained, the input optical axis Lin and the output optical axis Lout are always parallel, and the direction of the optical axis from the reflecting surface is constant. Can be eliminated by moving the right-angle prism 81 by half the amount of the deviation.

The input optical axis Lin and the output optical axis Lout should be parallel by maintaining the perpendicularity of the reflecting surfaces 81a and 81b, but a slight deviation occurs due to a processing error of the reflecting surfaces. Therefore, the direction of one of the optical axis 3a of the input light taking-in unit 3 and the optical axis 7a of the output light transmitting unit 7 is adjusted to the left and right (horizontal direction), and the left and right of the two optical axes 3a, 7a are adjusted. To eliminate the angle shift. In this example, as described above, the optical axis adjusting mechanism of the output light transmitting unit 7 is a pair of adjusting horizontal screws 7.
9a and 79b are provided, and the screwing amounts thereof are adjusted so that the horizontal direction of the optical axis 7a of the output light transmitting unit 7 matches the optical axis of the reflected light of the right-angle prism 81.

The height deviation between the optical axis 3a and the optical axis 7a is adjusted by turning the horizontal eccentric pin 38 of the optical axis adjusting mechanism of the input light take-in unit 3. Further, the optical axis 3a and the optical axis 7
The displacement of the vertical inclination angle of “a” is also adjusted by adjusting the screwing amount of the pair of adjusting vertical screws 39 a and 39 b of the input light capturing unit 3.

Next, referring to FIG.
The optical axis adjustment between the optical axis 3a and the optical axis 4a of the light receiving section 4 will be described. In this case, the optical axis 3a is already fixed as described above. Therefore, the other optical axis 4a is adjusted to coincide with the optical axis 3a. To this end, the optical axis adjustment mechanism of the light receiving unit 4 includes a vertical eccentric pin 47, a horizontal eccentric pin 49, a pair of horizontal adjusting screws 48a, 48b, and a pair of vertical adjusting screws 42b, 42c. By adjusting the rotation amount and the screwing amount, the height position, the left and right position, the vertical inclination angle, and the left and right direction of the optical axis 4a are adjusted to match the optical axis 3a.

Similarly, the adjustment of the optical axis between the optical axis 5a of the light emitting section 5 and the optical axis 7a of the output light transmitting section 7 is also performed because one optical axis 7a is already fixed. The other optical axis 5a is adjusted to match. The optical axis adjustment mechanism of the light emitting unit 5 also includes a vertical eccentric pin 57, a horizontal eccentric pin 59, a pair of horizontal screws 58a and 58b for adjustment, and a pair of vertical screws 5 for adjustment.
2b and 52c. By adjusting the amount of rotation and the amount of screwing, the height position, left and right position, vertical inclination angle, and left and right direction of the optical axis 5a are adjusted.
It is made to coincide with the optical axis 7a.

After adjusting the optical axis as described above,
Adjustment screws 39a, 39b, 79a, 79 for each part
b, 89d, 89e, 48a, 48b, 42b, 42
c, 58a, 58b, 52b, 52c, and the like are bonded and fixed.

(Other Embodiments) In the optical transmission module having the above-described configuration, the optical axis adjusting mechanism disposed in the input light receiving section 3 is disposed on the output light transmitting section 7 side, and disposed in the output light transmitting section 7. The optical axis adjusting mechanism may be arranged on the side of the input light capturing unit 3.

In the above example, the optical transmission module 1
Although no reference has been made to materials such as the housing 11 and the support block of each part, generally, a metal material having little thermal deformation can be used. However, it is also possible to use a molded product using a resin material with little thermal deformation.

Further, in the above example, an electromagnetic solenoid is used as a drive mechanism for moving the right-angle prism up and down. This electromagnetic solenoid has a structure in which the plunger is moved up and down along a vertical guide shaft, and requires a predetermined height dimension. In order to reduce the thickness of the drive mechanism, for example, a drive mechanism including a combination of a direct-acting voice coil, a diaphragm, and a stopper for regulating a movement range can be adopted.

On the other hand, the optical axis adjusting mechanism of the optical transmission module according to the present invention can be applied to a conventional optical transmission module as shown in FIG. 7 which does not have an optical path switching optical element. In this case, only the adjustment of the optical axis between the input light taking-in unit 3 and the light receiving unit 4 which are arranged oppositely and the adjustment of the optical axis between the light emitting unit 5 and the output light sending unit 7 which are arranged oppositely are performed. Just do it. Therefore, the input light capturing unit 3 and the light receiving unit 4
An optical axis adjusting mechanism having two eccentric pins attached to the light receiving section 4 in the above example is arranged on one side of the light emitting section 5 and one side of the light emitting section 5 and the output light sending section 7 on one side. A similar optical axis adjustment mechanism attached to the light emitting unit 5 in the above example may be provided.

In this specification, the vertical and vertical positions of the optical axis, the horizontal and horizontal positions of the optical axis, the inclination adjustment in the horizontal plane, the inclination adjustment in the vertical plane, and the like are described. Means to adjust the position and inclination of the optical axis in two orthogonal planes including the optical axis. Therefore, "up and down", "height" or "vertical plane", and "right and left" ”,“ Horizontal ”or“ horizontal plane ”
A term used to define the relative relationship between two orthogonal directions.

[0076]

As described above, in the optical transmission module of the present invention, the optical axis adjusting mechanism composed of the eccentric pin and the adjusting screw is arranged on one side of the optical component opposed to the optical component. The vertical and horizontal positions of the optical axis, and the tilt of the optical axis in the vertical and horizontal directions can be adjusted. Therefore, according to the present invention, the optical component is accurately held at the position after the optical axis adjustment by the eccentric pin and the adjusting screw. Further, since the optical component is fixed to the base of the optical transmission module by the adhesive via the adjusting screw, the adjustment position does not shift due to the curing shrinkage of the adhesive. Therefore, according to the present invention, it is possible to adjust and fix the optical axis of the optical component with a simple operation and with high accuracy.

Further, the present invention employs a configuration in which an optical transmission module having an optical path switching optical element is provided with a position adjusting mechanism capable of adjusting the left and right positions of the optical element with an adjusting screw. By moving the optical element to the left and right, the inter-axis dimensions of the input light taking-in section and the output light sending-out section can be easily adjusted.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of an optical transmission module to which the present invention is applied.

FIG. 2 is a longitudinal sectional view of the optical transmission module of FIG.

FIG. 3A is a diagram illustrating the optical transmission module 3A-3 of FIG. 2;
FIG. 3B is a cross-sectional view of a portion cut along line A, and FIG. 3B is a side view of the optical transmission module in FIG.

FIG. 4A is an optical transmission module 4A-4A of FIG. 2;
FIG. 4B is a cross-sectional view of a portion cut along a line, and FIG. 4B is a cross-sectional view of a portion cut along a line 4B-4B of the optical transmission module of FIG.

FIG. 5 is an explanatory diagram showing an optical axis adjustment operation among an input light intake unit, a right-angle prism, and an output light transmission unit in the optical transmission module of FIG. 2;

FIG. 6 is an explanatory diagram illustrating an optical axis adjustment operation of a light receiving unit in the optical transmission module of FIG. 1;

FIG. 7 is an explanatory diagram showing a conventional optical transmission module.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical transmission module 2 Input side optical fiber cable 3 Input light taking-in part 3a Optical axis 31 Support block 38 Horizontal eccentric pin 39a, 39b Vertical screw for adjustment 4 Light receiving part 4a Optical axis 41 Outer support block 42 Inner support block 47 Vertical eccentric pin 49 Horizontal eccentric pin 42c, 42d Vertical screw for adjustment 48a, 48b Horizontal screw for adjustment 5 Light emitting unit 5a Optical axis 51 Outer support block 52 Inner support block 57 Vertical eccentric pin 59 Horizontal eccentric pin 52c, 52d Vertical screw for adjustment 58a, 58b Adjustment Horizontal screw for output 6 Output side optical fiber cable 7 Output light sending section 7a Optical axis 78 Support shaft 79a, 79b Horizontal screw for adjustment 8 Optical path switching means 81 Right angle prism 81a, 81b Reflection surface 82 Drive mechanism PC (n) Information processing terminal

Continued on the front page (72) Inventor Shinji Nagaoka 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo F-term in Nippon Telegraph and Telephone Corporation (reference) 2H037 AA01 BA31 CA32 DA06 DA19 DA21 2H041 AA14 AB12 AC04 AZ02 AZ03

Claims (9)

[Claims] An input light receiving section connected to the input side optical fiber cable, a light receiving section, a light emitting section, and an output light transmitting section connected to the output side optical fiber cable;
In the optical transmission module, the input light capturing unit and the light receiving unit are arranged to face each other so that an optical axis thereof coincides, and the light emitting unit and the output light sending unit are arranged to face each other so that an optical axis thereof coincides with each other. A first optical axis adjusting mechanism for adjusting the optical axis of one of the light receiving unit and the light receiving unit, and adjusting the optical axis of one of the light emitting unit and the output light transmitting unit The first and second optical axis adjusting mechanisms respectively adjust the left and right positions of the optical axis using eccentric rotation about a vertical axis. A vertical eccentric pin, an adjusting horizontal screw for adjusting the horizontal direction of the optical axis, a horizontal eccentric pin for adjusting the vertical position of the optical axis by using eccentric rotation about a horizontal axis, and an upper and lower optical axis. Adjustment vertical screw to adjust the direction inclination The optical transmission module characterized by comprising a. 2. The optical path according to claim 1, further comprising: an optical path switching optical element including an optical path switching optical element, and a drive mechanism for moving the optical path switching optical element to an optical path switching position and a retracted position. With the switching optical element interposed therebetween, the input light capturing and the output light transmitting section are arranged on one side, the light receiving section and the light emitting section are arranged on the other side, and the optical path switching optical element is While in the retracted position, input light emitted from the input light capturing unit is irradiated on the light receiving unit, output light emitted from the light emitting unit is irradiated on the output light transmitting unit, and the optical path switching optical element is used. Moves to the optical path switching position, the light emitted from the input light taking-in section emits the light by the optical path switching optical element without irradiating the light receiving section. An optical transmission module, which is guided to a side sending unit. 3. The optical path switching optical element according to claim 2, wherein at the optical path switching position, a pair of optical elements that are inclined by 45 degrees with respect to the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit. An optical transmission module comprising: a reflection surface. 4. The optical transmission module according to claim 2, wherein the optical path switching optical element is a right-angle prism. 5. The position adjusting mechanism according to claim 3, further comprising a position adjusting mechanism for adjusting a position of the optical path switching optical element with respect to an optical axis of the input light capturing unit and the output light transmitting unit in a left-right direction. The position adjustment mechanism includes an adjustment horizontal screw that adjusts the position of the optical path switching optical element in the left-right direction with respect to the optical axis of the input light capturing unit and the optical axis of the output light sending unit. Optical transmission module. 6. The optical axis adjusting mechanism according to claim 5, wherein the first optical axis adjusting mechanism adjusts an optical axis of the light receiving section, and the second optical axis adjusting mechanism adjusts an optical axis of the light emitting section. A third optical axis adjusting mechanism for adjusting an optical axis of the input light capturing unit, and a fourth optical axis adjusting mechanism for adjusting an optical axis of the output light transmitting unit, One of the third and fourth optical axis adjustment mechanisms is for adjusting the vertical eccentricity of the optical axis by using a horizontal eccentric pin that adjusts the vertical position of the optical axis using eccentric rotation about a horizontal axis. Wherein the other of the third and fourth optical axis adjusting mechanisms includes an adjusting horizontal screw for adjusting the inclination of the optical axis in the left-right direction. Transmission module. 7. The method for adjusting the optical axis of an optical transmission module according to claim 6, wherein a horizontal position of the optical path switching optical element is adjusted using a horizontal screw for adjustment of the position adjustment mechanism. By adjusting the inter-axis dimension of the optical axis of the input light capturing unit and the output light transmitting unit, using the adjusting vertical screw and the adjusting horizontal screw of the third and fourth optical axis adjusting mechanisms, Adjusting the inclination in the vertical direction and the inclination in the horizontal direction between the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit; and the horizontal eccentric pin of the third and fourth optical axis adjusting mechanisms. By adjusting the vertical position of the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit, the optical axis of the light receiving unit by the first optical axis adjustment mechanism of the input light capturing unit The light emitting unit is aligned with the optical axis by the second optical axis adjusting mechanism. The optical axis is aligned with the optical axis of the output light transmitting unit, and the adjusting horizontal screw of the position adjusting mechanism, and the adjusting horizontal screw and the adjusting vertical screw of each of the optical axis adjusting mechanisms are adhesively fixed. Axis adjustment method of optical transmission module. 8. An input light receiving section connected to an input side optical fiber cable, a light receiving section, a light emitting section, an output light transmitting section connected to an output side optical fiber cable, and an optical path switching means, The optical path switching means includes an optical element for switching an optical path,
A drive mechanism for moving the optical path switching optical element to an optical path switching position and a retracted position, wherein the input light taking-in and the output light sending unit are arranged on one side with the optical path switching optical element interposed therebetween, The light receiving unit and the light emitting unit are disposed on the other side, and while the optical path switching optical element is at the retracted position, input light emitted from the input light capturing unit is applied to the light receiving unit, When the output light emitted from the light emitting unit is applied to the output light sending unit and the optical path switching optical element moves to the optical path switching position, the light emitted from the input light capturing unit irradiates the light receiving unit. The optical path switching optical element guides the optical path switching optical element to the output side sending unit without performing the optical path switching optical element. And a pair of reflecting surfaces each inclined at 45 degrees with respect to the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit, and further adjusting the optical axis of the input light capturing unit. For adjusting the optical axis of the output light transmitting unit, and a position adjusting mechanism for adjusting the position of the optical path switching optical element. One of the input-side and output-side optical axis adjustment mechanisms,
A horizontal eccentric pin for adjusting the vertical position of the optical axis using eccentric rotation about a horizontal axis, and an adjusting vertical screw for adjusting the vertical tilt of the optical axis; The other of the axis adjustment mechanisms includes an adjustment horizontal screw for adjusting the inclination of the optical axis in the left-right direction, and the position adjustment mechanism switches the optical path with respect to the optical axes of the input light intake unit and the output light transmission unit. An optical transmission module comprising an adjustment horizontal screw for adjusting the position of the optical element for use in the left-right direction. 9. The method for adjusting an optical axis of an optical transmission module according to claim 8, wherein a horizontal position of the optical path switching optical element is adjusted using a horizontal screw for adjustment of the position adjusting mechanism. By adjusting the inter-axis dimension of the optical axis of the input light capturing unit and the output light sending unit, using the adjusting vertical screw and the adjusting horizontal screw of the input-side and output-side optical axis adjusting mechanism, Adjusting the vertical tilt and the horizontal tilt between the optical axis of the input light capturing unit and the optical axis of the output light transmitting unit, using the horizontal eccentric pins of the input-side and output-side optical axis adjusting mechanisms. Adjusting the vertical position of the optical axis of the input light capturing unit and the optical axis of the output light sending unit; adjusting the horizontal screw of the position adjusting mechanism; and adjusting the position of the first and second optical axis adjusting mechanisms. Adjust vertical screw and horizontal screw for adjustment. Method of adjusting an optical axis of an optical transmission module, characterized in that the wear fixed.