JPH02135307A - Optical transmission link - Google Patents

Abstract

PURPOSE:To irradiate the light reception surface of an optical transmission part with light emitted by a light emitting element and to improve signal transmission efficiency by reflecting the light emitted by the light emitting element by a concave surface reflecting surface and then making the light incident on the optical transmission part. CONSTITUTION:The concave reflecting surface 14a of the light emission part 14 is formed in a spheroidal shape, the light emitting element 11 is arranged at one focus of the concave reflecting surface 15, and the light reception surface 31a of the optical transmission part is arranged at the other focus. The concave reflecting surface 15 reflects and converges the light emitted by the light emitting element 11 and then emits the light to the light reception surface 31a of the optical transmission part. The light which enters the optical transmission part is transmitted by an optical fiber 31 to illuminate the light receiving element 21 of the light reception part from the emission surface 31b of the optical transmission part 30 and the light receiving element 21 converts the received light into an electric signal, which is led out through a lead part for light reception. Consequently, the light signal emitted by the light emitting element is transmitted efficiently to the light reception part.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to optical transmission links used primarily for communications.

[Conventional technique]

Conventionally, optical transmission links of various structures have been devised as optical transmission links for optical fiber transmission type optical communication. FIG. 9 is a schematic diagram of a conventional optical transmission link, and FIG. 10 is a diagram showing the optical path of light emitted by a light emitting element of the light emitting section. 9th
In the figure and FIG. 10, 50 is a light emitting part, 60 is a light receiving part,
70 is an optical transmission section.

The light emitting unit 50 includes a light emitting element 51 and a light emitting reed 52a.
52b, wires 53a and 53b, steno, 54,
The R-shaped portion 54a formed on the stem 54 and the ball lens 5
5, support portions 56 of the ball lens 55, and a receptor portion 57. The light emitting element 51 is a conductive part 54
a, and electrically connected to leads 52a and 52b by wires 53a and 53b. Also,
A ball lens 55 is arranged in front of the light emitting element 51 and is housed integrally in the receptor section 57.

The light receiving section 60 includes a light receiving element 61 and a light receiving glue 62a.
=62b, wires 63a and 63b, a stem 64, a conductive part 64a formed on the stem 64, a ball lens 65, support parts 66 and 66 of the ball lens 65, and a receptor part 67. There is. Further, the light receiving element 61, the ball lens 65, etc. are arranged in the same manner as the light emitting section 50.

The optical transmission section 70 is formed of an optical fiber huff 1, a light receiving plug section 72 attached to one tip of the optical fiber 1, and a radiation plug section 73 attached to the other tip of the optical fiber. There is. Note that 71a is one end surface of the optical fiber 71, which is a light receiving surface that receives the light emitted by the light emitting section 50, and 71b is the other end surface of the optical fiber 1, which is a radiation receiving surface that emits the transmitted light to the light receiving section 60. It is a surface.

By inserting the light receiving plug section 72 of the light transmission section 70 into the receptor section 57 of the light emission section 50, the light emission section 50 and the light transmission section 70 can be coupled.

On the other hand, the radiation plug section 73 of the optical transmission section 70 is connected to the light receiving section 6.
By inserting it into the receptor section 67 of 0, the optical transmission section 7
0 and the light receiving section 60 can be combined.

In the conventional optical transmission link configured as above,
The electrical input signal is transmitted to the ζ light emitting unit 50 via a transmission circuit (not shown).
When the input is input to the leads 52a and 52b of the light emitting element 51, the light emitting element 51 emits light, and the light emitted by the light emitting element 51 follows an optical path as shown by the arrow in FIG.
The light is focused on.

The light incident on the light receiving section 71 a is transmitted by the optical fiber 71 and is emitted from the radiation surface 71 b of the light transmitting section 70 to the light receiving section 60 . This emitted light is focused by the ball lens 65 of the light receiving section 60 and irradiated onto the light receiving surface of the light receiving element 61, and is extracted as an electrical output signal via the light receiving leads 62a and 62b. The electrical output signal is then transmitted to an external circuit via a receiving circuit (not shown).

In this way, the electrical input signal is converted into an optical signal by the light emitting unit 50, and behind the light emitted by the light emitting element 51, the Tel lens 55
The emitted light is focused by the lens effect and emitted to the light receiving surface 71 of the light transmission section 70.

Therefore, these lights contribute to improving the signal transmission efficiency of the optical transmission link.

[Problem to be solved by the invention]

However, among the light emitted by the light emitting element 51, the light emitted in the side direction is not directly radiated to the surface of the spherical lens 55, and does not reach the light receiving surface 71a of the light transmission section 70...it becomes a tip. . Furthermore, since the solid angle ω of the I-member tip emitted in the lateral direction was large, there was a large amount of light flux at the tip.

Further, since the light emitting surface of the light emitting element 51 has a relatively large light emitting area compared to the ball lens 55, the light emitting element 51 cannot be regarded as a point light source with respect to the ball lens 55. For this reason, the light emitted by the light emitting element 51 could not be sufficiently controlled by the bulb lens 55.

Furthermore, in order to efficiently condense the light emitted by the light emitting element 51 using the lens effect of the ball lens 55, the light emitting element 5
1 and the light receiving surface 71a of the light transmitting section 70, an air layer is required between the light receiving surface 71a of the light transmitting section 70, and an optical loss of about 10% occurs due to the interfacial reflection of this air layer.

As described above, in the conventional optical transmission link, there is a large amount of wasted light that does not reach the light receiving surface 71a of the optical transmission section 70, so the signal transmission efficiency of the optical transmission link is poor.

Furthermore, in the conventional optical transmission link, in order to improve the light coupling efficiency, the ball lens 55 must be formed by precision micromachining, and the light-receiving surfaces of the light emitting element 51, the ball lens 55, and the light transmission section 70 must be formed by precision micromachining. Since it is necessary to accurately align with 71a, there is a drawback that manufacturing is not easy.

The present invention has been made based on the above circumstances, and aims to improve signal transmission efficiency by efficiently emitting light emitted by a light emitting element to a light receiving surface of an optical transmission section, and has a simple structure. The objective is to provide an optical transmission link that is easy to manufacture.

[Failure to solve the problem]

To achieve the above object, an optical transmission link according to the present invention includes a light emitting section including a light emitting element that converts an electric signal into an optical signal and a light emitting lead section that inputs an electric signal to the light emitting element; An optical transmission section that transmits the light emitted by the light emitting section using an optical fiber, a light receiving element that receives the light transmitted by the optical transmission section and converts it into electricity, and a light receiving lead section that extracts an electrical signal from the light receiving element. after converting an electrical input signal into an optical signal by the light emitting part, the optical signal is transmitted to the light receiving part by the optical transmission part, and the light receiving part converts the optical signal into an electrical signal. In the optical transmission link for converting into an output signal and taking out the output signal, the light emitting section includes a concave reflecting surface provided on the light emitting surface side of the light emitting element to face the light emitting element, so that the light emitted by the light emitting element is directed to the light emitting element. After being reflected by a concave reflective surface, the light is configured to enter the light transmission section.

The concave reflective surface of the light emitting section is formed in the shape of an ellipsoid of revolution, the light emitting element is disposed at one focal point of the concave reflective surface, and the light receiving surface of the light transmission section is disposed at the other focal point. preferable.

It is preferable that the concave reflective surface of the light emitting unit reflects the light emitted by the light emitting element such that the angle of incidence on the optical fiber is within a maximum angle of incidence range of the optical fiber. .

The light receiving section includes a concave reflective surface provided on the light receiving surface side of the light receiving element to face the light receiving element, and after the light transmitted by the light transmitting section is reflected on the concave reflective surface,
The light may be configured to be incident on the light receiving element.

It is preferable that the concave reflective surface of the light receiving section is formed in the shape of an ellipsoid of revolution, that the light receiving element is disposed at one focal point, and the emitting surface of the light transmitting section 1171 is disposed at the other focal point.

At least one of the light emitting section and the light receiving section may be integrally molded with a light-transmitting material.

[Effect]

With the above-described configuration of the optical transmission link according to the present invention, when an electrical signal is input to the light emitting element from the light emitting lead part of the light emitting part, the light emitting element converts this into an optical signal. The concave reflective surface reflects and condenses the light emitted by the light emitting element, and then radiates the light to the light receiving surface of the light transmission section.

The light incident on the light transmitting section is transmitted through an optical fiber, and is irradiated from the radiation surface of the light transmitting section to the light receiving element of the light receiving section. The light-receiving element converts the received light into an electrical signal, and this electrical signal is taken out to the outside via a light-receiving lead. In this way, the light emitted by the light-emitting element is reflected by the concave reflective surface.
Since the light is focused and then radiated to the optical transmission section, the optical signal emitted by the light emitting element can be efficiently transmitted to the light receiving section.

The concave reflective surface of the light emitting section is formed in the shape of an ellipsoid of revolution, the light emitting element is disposed at one focal point of the concave reflective surface, and the light receiving surface of the light transmission section is disposed at the other focal point. , it is possible to reliably and efficiently reflect and collect the light emitted by the light emitting element and radiate it to the light transmission section.

The concave reflective surface of the light emitting unit is configured to reflect the light emitted by the light emitting element such that the angle of incidence on the optical fiber is within a maximum angle of incidence range of the optical fiber. Since the light incident on the optical transmission section does not leak to the outside from the side surface of the optical transmission section, it is possible to improve the transmission efficiency of optical signals.

The light receiving section includes a concave reflecting surface provided on the light receiving surface side of the light receiving element, facing the light receiving element, and after the light transmitted by the light transmitting section is reflected on the concave reflecting surface. By configuring the light to be incident on the light receiving element, the structure of the light receiving section is simple and manufacturing is easy.

]) The concave reflecting surface of the light receiving section is formed in the shape of an ellipsoid of revolution, the light receiving element is disposed at one focal point, and the emitting surface of the light transmitting section is disposed at the other focal point. The light sent from the light transmission section can be efficiently irradiated onto the light receiving element.

111 At least one of the light emitting section and the light receiving section is integrally molded with a light transmitting material. For example, when the light emitting section is integrally molded with a light transmitting material, a light emitting element or a light emitting can protect the lead part from shock and vibration. The same applies when the light receiving section is molded with a light-transmitting material.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram of an optical transmission link according to a first embodiment of the present invention, and FIG. 2 is a diagram showing an optical path of light emitted by a light emitting element of a light emitting section. In FIGS. 1 and 2, 10 is a light emitting unit that converts an electrical input signal into an optical signal;
0 is a light receiving section that converts an optical signal into an electrical output signal and outputs it to the outside, and 30 is an optical transmission section that transmits the optical signal.

The light emitting unit 10 includes a light emitting element 1 that converts an electrical signal into an optical signal.
1, leads 12a and 12b for light emission, a wire 13, and a light emitting part main body 14. The light emitting section body 14 includes a reflecting section 14 a on which a concave reflective surface 15 is formed to reflect the light emitted by the light emitting element 11 , and a receptor section 14 b for coupling with the light transmitting section 30 . The light emitting element 11 is mounted on one light emitting glue 12a and electrically connected to the other light emitting lead 12b by a wire 13. Further, a reflecting portion 14 facing the light emitting surface of the light emitting element 7-11
The surface of a is formed into a rotating tM circular shape with the light emitting element 11 as the focal point, and a concave reflective surface 15 is formed on this surface by mirror finishing, for example, by plating or metal rotation. The concave reflective surface 15 is formed so that the angle of incidence of the reflected light onto the optical fiber 31 (described later) is within the maximum angle of incidence of the optical fiber 31.

The light receiving section 20 includes a light receiving element 21 and a lead 22a for receiving light.
22b, wires 23a-23b, stem 24, conductive portion 24a formed on stem 24, and ball lens 25.
, support portions 26 of the FEE lens 25, and a receptor portion 27. The light receiving element 21 is the conductive part 2
4a and leads 22a and 22b for light reception.
and are electrically connected by wires 23a and 23b.

Further, an f, y lens 25 is arranged in front of the light receiving element 21, and these lenses are housed integrally in the receptor section 27.

The optical transmission section 30 includes an optical fiber 31 and a plug section 32 for light reception.
and a radiation plug portion 33. The light emitting section 10 and the light transmitting section 30 can be coupled by inserting the light emitting plug section 32 of the light transmitting section 30 into the receptor section 14b of the light emitting section IO. Further, by inserting the radiation plug section 33 of the light transmission section 30 into the receptor section 27 of the light reception section 20, the light reception section 20 and the light transmission section 30 can be coupled. Note that 31a is one end face of the optical fiber 31, and is a light-receiving surface that receives the light emitted by the light-emitting section 10. The light-receiving surface 31a is arranged to be located at the other focal point (light convergence point) of the concave reflecting surface 15 formed in the shape of an ellipsoid of revolution.

31b is the other end surface of the optical fiber section 3I, and is a radiation surface that radiates the transmitted light to the light receiving section 20.

According to the above configuration, an electric signal is input to the light emitting element 11 through the light emitting leads 12a and 12b and the wire 13, and the light emitting element 11 emits light. Then, the light emitted by the light emitting element 11 is transmitted to the concave reflective surface 15 as shown by the arrow in FIG.
After being reflected by the concave reflective surface 15, the light is focused on the light receiving surface 31a of the optical fiber 31 and radiated.

The light incident on the light receiving surface 31a of the optical fiber 31 is transmitted by the optical fiber 31, and is transmitted to the light receiving surface 31b of the optical fiber 31.
The spherical lens 25 of the light receiving section 20 is irradiated from the beam. and,
The irradiated light is focused on the light receiving element 21 by the lens effect of the ball lens 25, and is converted into an electrical signal by the light receiving element 21. The converted electric signal is sent to the light receiving lead 22a.
It is taken out to the outside via 22b. In this way, the concave reflective surface 15 of the light emitting unit IO of this embodiment is formed in the shape of a spheroid, and the light emitting element 11 and the light receiving surface 31a of the optical fiber 31 are located at the two focal points of the concave reflective surface 15. Since they are arranged, the light emitted by the light emitting element 11 can be effectively transmitted to the light transmission section 30 without any loss. Further, the concave reflective surface 15 is formed such that the incident angle of the light reflected by the concave reflective surface 15 to the light receiving portion 31a of the optical fiber 31 is within the maximum incident angle of the optical fiber 31. The light incident on the light receiving surface 31a of the optical fiber 31 does not leak to the outside from the side surface of the optical fiber 31.

According to the above embodiment, the light emitted by the light emitting element 11 is efficiently transferred to the light receiving surface 30 of the light transmitting section 30 by the concave reflecting surface 15.
Since the light can be focused on the light receiving surface 31a of the light transmitting section 30 and the incident angle on the light receiving surface 31a of the light transmitting section 30 can be reduced, the loss of light can be eliminated.
Light coupling efficiency can be improved. Therefore, the electrical signal input to the light emitting section 1O can be converted into an optical signal and efficiently transmitted to the light receiving section 20, so that signal transmission efficiency can be improved. As a result, when using light emitting elements with the same output, the transmission distance can be increased compared to conventional optical transmission links.

Further, if the transmission distance is the same as that of the conventional method, an inexpensive light emitting element with low output can be used.

In addition, according to the above embodiment, the light emitting part 10 does not use an expensive ball lens formed by precision micromachining, so the structure of the light emitting part is a component, and the manufacturing process is a package, and the cost is low. It is possible to reduce the

In the first embodiment, the light receiving surface 31a of the light transmitting section 30 fixed to the light emitting section 10 is arranged at the other focal point of the concave reflecting surface 15 formed in the shape of an ellipsoid of revolution. As described above, for example, when the cross section of the optical fiber 31 is thick, the light receiving section 31a of the optical transmission section 30 is located at a position where all the light reflected by the concave reflecting surface 15 can be received. The focal point position of the reflective surface 15 may be shifted from the other focal point position.

FIG. 3 is a schematic cross-sectional view showing a first modified example of the light emitting section. In FIG. 3, 16 is a light-transmitting material. Furthermore, the third
The first modified example shown in the figure and the second modified example, second embodiment, and third embodiment described below have the same functions as the first embodiment shown in FIGS. 1 and 2 above. Those having the same reference numerals are given the same reference numerals, and detailed explanation thereof will be omitted.

In this modification, the light emitting element 11 and the light emitting lead '12a-
The space between the concave reflective surface 15 including 12b and the like and the light receiving surface 3La of the light transmitting section 30 is filled with a light transmitting material 16.

In this modification, the optical path of the light emitted by the light emitting element 11 is filled with the light transmitting material #F) 16 due to the above configuration.
The external quantum efficiency (extraction efficiency) of the light emitting element 11 can be improved. For example, when filled with epoxy resin having a refractive index of 1.5, the external quantum efficiency of the light emitting element 11 is theoretically improved by more than twice. This has also been confirmed by experiments conducted by the inventors. Further, by filling the light-transmitting material 16, the light emitting element 11, the wire 13, etc. can be protected, and failures due to shocks, vibrations, etc. can be prevented.

In addition, the light-transmitting material 16 and the light-receiving surface 31a of the light transmission section 3o
The light transmission efficiency can be further improved by applying a binder to the joint portion to prevent air from entering. Other functions and effects are the same as those of the first embodiment.

Note that the optical i3-transmissive material 16 is not filled in the entire hollow space between the concave reflective surface 15 and the light receiving surface 31a of the light transmitting section 30, but is filled around the light emitting element 11, between the light emitting element 11 and the concave reflective surface. Only the space between the surface 15 or the space between the light emitting element 11 and the light receiving section 31a of the optical transmission section 30 may be partially molded.

In addition, if ease of manufacture is important, the surfaces of the light emitting leads 12a and 12b and the light emitting element 11 mounted thereon may be coated with a light transmitting material 16.
For example, spray coating or the like may be applied to prevent failures due to shocks, vibrations, etc. On the other hand, if there is no need to take into account disconnection or failure of the light emitting element 11 or the like due to impact or the vibration tube, it may be left hollow, or the hollow portion may be filled with gas or the like as necessary. Note that the light-transmitting material 16 is not limited to a solid state, but may be in a gel state or a liquid state.

FIG. 4 is a schematic diagram of an optical transmission link according to a second embodiment of the present invention, and 5 UjJ is a diagram showing the optical path of light emitted by the light emitting element of the light emitting section. In FIGS. 4 and 5, 17 is a light-transmitting material, 18 is a concave reflective surface that reflects the light emitted by the light emitting element 11, and 17a is a radiation surface that radiates the light reflected by the concave reflective surface in one day. .

The second embodiment of the present invention differs from the first embodiment in that the light emitting unit main body 14 of the light emitting unit 10 and the plug part 32 of the optical transmission unit 30 in the first embodiment are omitted, and the light emitting element 11 is omitted.
．． Parts of the leads 12a and 12b, the wire 13, the concave reflective surface 18, and the optical path of light emitted by the light emitting element 11 are integrally molded with a light-transmitting material 17. The end face of the light-transmitting material 170 facing the light-emitting surface of the light-emitting element 11,
The light-emitting element 11 is formed into a spheroidal shape with the focal point, and the end face is treated with plating or metal vapor deposition to form a concave reflective surface 18, and - on the back side of the light-emitting element 11 of the transparent material 17. The located end face is formed into a planar shape and serves as a radiation surface 17a. Then, the radiation surface 17a and the optical transmission section 3
The light-receiving surface 31a of No. 0 is bonded and bonded with an adhesive.

The other configurations are similar to the first embodiment.

According to the second embodiment, the light emitting section 10 includes the light emitting element 11
The leads 12a, 12b, etc. are integrally formed with the photo-i3-transparent material 1.
7, and the concave reflecting surface 18 and the emitting surface 17a are formed on the end face of the light-transmitting material 17, so that the structure of the light emitting part 10 is simplified. Therefore, manufacturing of the optical transmission link becomes easy, and mass productivity can be improved.

Further, according to the second embodiment, the emission surface 17a of the light emitting section 10 is formed of the optical i3-transmissive material 17, and the emission surface 17a is a light converging surface. 17a and the light-receiving surface 31a of the light transmission section 30 are bonded together with an adhesive, the optical system can be easily aligned. Other effects are similar to those of the first embodiment.

In the second embodiment, a case has been described in which the connecting portion between the emitting surface 17a of the light emitting section 10 and the light receiving surface 31a of the light transmitting section 30 is bonded and connected using an adhesive. A receptor section similar to the light receiving section 20 may be provided, while a plug section may be provided in the optical transmission section 30, and the connection may be made by inserting the plug section into the receptor section. In this case, the bonding portion may be further bonded with an adhesive to prevent an air layer from forming on the optical path.

Furthermore, in the second embodiment, a case has been described in which the light emitting section 1O and the light transmission section 30 are formed separately and combined, but a part or all of the optical fiber 31 of the light transmission section 30 is When molding the light-emitting element 11 and the like with the light-transmitting material 17, it may be formed integrally.

FIG. 6 is a schematic sectional view of a light receiving section according to a third embodiment of the present invention, and FIG. 7 is a diagram showing an optical path where the light receiving element receives light. In FIGS. 6 and 7, 220 is a lead part, 28 is a light-transmitting material, 28a is a light-receiving surface that receives the light transmitted from the light transmission part, and 29 is a concave reflective surface that reflects the received light. . This embodiment is different from the first and second embodiments in that the ball lens 25, receptor section 27, etc. of the light receiving section 20 in the first and second embodiments are omitted, and the light receiving section 20 is Also, a concave reflective surface 29 is provided. Incidentally, since the light emitting section is the same as that in the first or second embodiment, detailed explanation thereof will be omitted.

The light receiving section 20 of this embodiment is constructed by forming the end surface of the light transmitting material 28 that receives light from the light transmitting section 30 into a planar shape.
8a, the end face facing the light receiving surface 28a and the light receiving element 21 of the light transmitting material 28 is formed into a spheroidal shape, and this end face is processed by plating or metal vapor deposition to form a concave reflective surface 29. A light receiving surface 28a of the light receiving section 20 is arranged at one focal point of the concave reflective surface 29, and a light receiving element 21 is arranged at the other focal point. Then, the connecting portion between the light receiving surface 28a of the light receiving section 20 and the emitting surface 31b of the light transmitting section 30 is bonded and bonded with an adhesive.

Further, the light receiving element 21 and the light receiving surface 28a of the light receiving section 20 are arranged close to each other in the vertical direction of the figure as shown in FIG. The size is within the range. The other configurations are the same as those of the first or second embodiment.

According to the above configuration, the light emitted from the light emitting section 10 is transmitted by the light transmitting section 30 and reaches the light receiving surface 2 of the light receiving section 20.
8a is irradiated. The irradiated light is reflected by the concave reflecting surface 29 as shown by the arrow in FIG. 7, and is focused on the light receiving element 21.

According to the third embodiment, the light receiving element 21 and the light receiving surface 28
Since the portions a are arranged close to each other and integrally formed, and the reflection area of the concave reflection surface 29 is small, the structure is small and simple.

Further, according to the third embodiment, the light receiving element 21 of the light receiving section 20 is not placed on the optical path of the light received by the light receiving surface 28a, so no shadow loss due to the light receiving element 21 or the lead section occurs. .

In the third embodiment, the light-receiving element 21 of the light-receiving section 20 and the light-receiving surface 28a of the light-receiving section 20 are arranged close to each other in the vertical direction. A concave reflective surface similar to the concave reflective surface is formed, and the light receiving element 21
and the light-receiving surface 28a of the light-receiving section 20 may be arranged in the left-right direction.

FIG. 8 is a schematic diagram showing an application example of the first embodiment and the second embodiment of the present invention. In FIG. 8, 102 is a light emitting section (2), 10b is a light emitting section (2), 20a is a light receiving section (2), 20b is a light receiving section (2), and 30a is a branch type optical transmission section. The optical transmission link in this application example is a 2 & 1 optical transmission link using a branch type optical transmission section 30a.
A two-way optical transmission link is formed by combining a light-emitting section and a light-receiving section. In addition, the light emitting part ■10a and the light receiving part ■
20a, the light emitting section 10b, and the light receiving section 20b are each paired.

In this application example, with the above configuration, the light emitted by the light emitting section (2) LOa is transmitted by the optical transmission section 30a and radiated to the light receiving section (20a). On the other hand, the light emitted by the light emitting section 10b is similarly transmitted by the light transmitting section 30a and radiated to the light receiving section 20b. In this way, the light that has entered the optical transmission section 30a is transmitted without being interfered with, so that, for example, the light emitting section
Optical multiplex transmission can be achieved by changing the wavelength of the light transmitted between 10a and the light receiving section 20a, and the wavelength of the light transmitted between the light emitting section 1Ob and the light receiving section 20b. . Other functions and effects are the same as those of the first embodiment or the second embodiment.

In addition, in the first to third embodiments described above, the optical transmission section 3
Although the optical transmission section 30 has been described with reference to the case where it is formed by one optical fiber, the optical transmission section 30 may be formed by bundling a plurality of optical fibers.

Furthermore, in the first to third embodiments described above, the case where one light-emitting element and one light-receiving element are used has been described, but the present invention is not limited to this, and multiple sets of light-emitting element and light-receiving element are used. may be used. In this case, if multiple light emitting elements with different emission wavelengths are used, wavelength multiplexed optical transmission can be performed.

〔Effect of the invention〕

As explained above, according to the present invention, the light emitted by the light emitting element can be efficiently radiated and transmitted to the optical transmission section by the concave reflective surface provided in the light emitting section, thereby improving signal transmission efficiency. An optical transmission link can be provided. Further, according to the present invention, since the No. 13 transmission efficiency is improved, it is possible to use inexpensive light-emitting elements with lower output than conventional ones, thereby providing an optical transmission link that can reduce costs. can do. Furthermore,
According to the present invention, since a ball lens is not used, the structure of the light emitting section is simplified, and the light emitting element and concave reflective surface of the light emitting section can be integrally formed with a light-transmitting material. An optical transmission link that is easy to manufacture can be provided.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an optical transmission link according to the first embodiment of the present invention, Fig. 2 is a diagram showing the optical path of light emitted by the light emitting element of the light emitting part, and Fig. 3 is a diagram showing the optical path of the light emitted by the light emitting element of the light emitting part. FIG. 4 is a schematic cross-sectional view showing a modified example; FIG. 4 is a schematic diagram of an optical transmission link according to a second embodiment of the present invention; FIG. The figure is a schematic sectional view of the light receiving section of the third embodiment of the present invention, FIG. 7 is a diagram showing the optical path of light received by the light receiving element, and FIG.
FIG. 9 is a schematic diagram of a conventional optical transmission link, and FIG. 10 is a diagram showing an optical path of light emitted by a light emitting element of a light emitting section. 10... Light emitting part, 11... 1 light emitting element, 12a-12
b...Lead for light emission, 13...Wire, 14...
- Light emitting part main body, 14a...Reflecting part, 14b...Receptor part of the light emitting part, 15, 18, 29... Concave reflective surface, 16, 17, 28... Light transmitting material, 17a. ,・
Radiation surface, 20... Light receiving section, 21... Light receiving element, 21a, 22
b...Lead for light reception, 23...Wire, 24...
・Stem, 24a... Conductive part, 25... 1-ball lens,
26... Support part, 27... Receptor part of light receiving part, 2
8a... Light receiving surface, 30... Optical transmission section, 31... Optical fiber, 31a...
...Light receiving surface, 31b...Emission surface, 32...Plug part for light reception, 33...Plug part for radiation. Applicant Iwasaki Electric Co., Ltd. Agent Patent Attorney Han 1) Masao Figure 2 Figure 5

Claims (6)

[Claims] (1) A light emitting section including a light emitting element that converts an electrical signal into an optical signal and a light emitting lead section that inputs an electrical signal to the light emitting element, and transmitting the light emitted by the light emitting section using an optical fiber. It has an optical transmission section, a light receiving section that includes a light receiving element that receives light transmitted by the optical transmission section and performs photoelectric conversion, and a light receiving lead section that extracts an electrical signal from the light receiving element, and receives an electrical input signal. In the optical transmission link, the optical signal is converted into an optical signal by the light emitting section, the optical signal is transmitted to the light receiving section by the optical transmission section, and the optical signal is converted into an electrical output signal by the light receiving section and taken out. The part includes a concave reflective surface provided on the light emitting surface side of the light emitting element to face the light emitting element, and after the light emitted by the light emitting element is reflected by the concave reflective surface, the light transmitting part An optical transmission link characterized in that the optical transmission link is configured such that the optical transmission link is incident on the optical transmission link. (2) The concave reflective surface of the light emitting section is formed in the shape of an ellipsoid of revolution, the light emitting element is disposed at one focal point of the concave reflective surface, and the light receiving surface of the light transmission section is disposed at the other focal point. 2. The optical transmission link according to claim 1, wherein the optical transmission link is (3) The concave reflective surface of the light emitting unit reflects the light emitted by the light emitting element so that the angle of incidence on the optical fiber is within the maximum angle of incidence of the optical fiber. An optical transmission link according to claim 1 or 2. (4) The light receiving section includes a concave reflective surface provided on the light receiving surface side of the light receiving element to face the light receiving element, and the light transmitted by the light transmitting section is reflected by the concave reflective surface. The optical transmission link according to any one of claims 1 to 3, wherein the optical transmission link is configured to enter the light receiving element after the light has been transmitted. (5) The concave reflecting surface of the light receiving section is formed in the shape of an ellipsoid of revolution, the light receiving element is arranged at one focal point, and the emitting surface of the light transmitting section is arranged at the other focal point. The optical transmission link according to claim 4. (6) The optical transmission link according to any one of claims 1 to 5, wherein at least one of the light emitting section and the light receiving section is integrally molded with a light-transmitting material.