JPH08146255A - Photoelectric converter - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the cost by reducing the number of electric circuit parts and making them smaller. A light emitting element 4 for projecting an optical signal to a light projecting optical fiber 81 in a case 3, a light receiving element for receiving an optical signal from a light receiving optical fiber 82, an amplification / signal processing circuit for this light receiving element, and Photo IC 5 in which a drive circuit for light emitting element 4 is integrated, connector 62, light emitting element 4 and photo IC
And a printed circuit board 6 on which 5 is mounted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectric converter for converting an optical signal into an electric signal or converting an electric signal into an optical signal by using a light receiving element or a light emitting element.

[0002]

2. Description of the Related Art FIG. 10 is a vertical sectional view showing an example of a conventional photoelectric converter, in which a main body case 11 accommodates the following parts. That is, an element case 17 having a light-shielding wall 14 formed of a conductive plastic for forming a storage chamber 13 for the light-receiving element 12 therein, and an optical fiber holding portion 16 for mounting an outer peripheral lower surface of the optical fiber 15, and a storage chamber. 1
3, the printed circuit board 18 on which the light receiving element 12 and the amplifier circuit (not shown) are mounted, the conductive lid 19 that closes the opening of the element case 17, and the printed circuit board 20 on which the signal processing circuit (not shown) is mounted. And a pressing tool 21 for pressing the outer peripheral upper surface of the optical fiber 15 so as to face the optical fiber holding portion 16.
An optical fiber fixture 28 including an operation lever 23 having an eccentric cam 22 for holding the retainer 21 is housed. The amplifier circuit and the signal processing circuit are connected by a lead wire 24, and the signal processing circuit is connected to the cable 2
It is pulled out to the outside of the body case 11 by 5. Also,
A guide groove 26 is provided in the holding member 21 of the optical fiber fixture 28 and the holding portion 16 so as to be perpendicular to the center of the light receiving surface of the light receiving element 12 along the axial direction of the optical fiber 15 to be held. There is. FIG. 11 is a view on arrow P in FIG. As shown in FIG. 11, a plurality of small protrusions 27 are provided on the surface of the guide groove 26 to prevent the optical fiber 15 from slipping (removing).

When the optical fiber 15 is attached to this photoelectric converter, the optical fiber 15 is inserted into the guide groove 26 of the holding tool 21 of the optical fiber fixing tool 28 and the guide groove 26 of the holding portion 16, and the tip end surface of the optical fiber 15 is received. It is brought into contact with the light receiving surface of the element 12.
In this state, if the operating lever 23 is operated and moved in the direction of the arrow Q, the eccentric cam 22 presses the pressing member 21, and the outer diameter of the optical fiber 15 is clamped between the guide groove of the pressing member 21 and the guide groove of the holding portion 16. Then, the optical fiber 15 is fixed.

When an optical signal is transmitted to the optical fiber 15 of this photoelectric converter, the optical signal enters the light receiving element 12 where it is converted into an electric signal, and this electric signal is amplified by an amplifier circuit mounted on the printed board 18. Printed circuit board 2 after being amplified
Cable 2 via the signal processing circuit installed in 0
It is output from 5. Here, the light-receiving element 12 and the amplifier circuit, which are susceptible to noise from the outside, have a conductive element case 1
Since it is shielded by 7 and the conductive lid 19, there is no electromagnetic interference from the outside. Since the electric signal after the amplifier circuit is amplified, it has a high voltage level and is not affected by external noise. Therefore, it is not necessary to shield the printed circuit board 20 on which the signal processing circuit is mounted, the lead wire 24, and the cable 25.

The above-mentioned photoelectric converter is an example for converting an optical signal into an electric signal, but when it is used for the purpose of converting an electric signal into an optical signal, the light receiving element 12 in FIG. 10 can be replaced with a light emitting element. Good. That is, an electric signal input from the electric cable 25 is processed and amplified by a signal processing circuit mounted on the printed circuit board 20 and an amplifier circuit mounted on the printed circuit board 18, converted into an optical signal by a light emitting element, and converted into an optical fiber. It is emitted from 15. Also,
When it is desired to perform both conversion of optical signal → electrical signal and electric signal → optical signal, the light emitting element is housed in parallel with the light receiving element 12 in FIG.

[0006]

Although the above-mentioned photoelectric converter has no problem in function, for example, in a converter that performs both optical signal-electrical signal and electric signal-optical signal conversion, the electric circuit has a light emitting element and a light receiving element. The element, the amplifier circuit mounted on the first printed board (indicated by reference numeral 18 in FIG. 10), and the second printed board (indicated by reference numeral 20 in FIG. 10) to which the electric cable is connected. It is composed of a signal processing circuit, a conductive element case for shielding the light receiving element and the amplifier circuit, a conductive lid, and the like, and has a large number of parts, resulting in a large size and high cost. Further, the optical fiber fixing tool is composed of a holding tool and an operating lever provided with an eccentric cam, and its structure is complicated, which also causes a cost increase.

An object of the present invention is to solve the above-mentioned problems and to reduce the number of parts of an electric circuit to provide a small-sized and low-cost photoelectric converter. Another object is to simplify the structure of the optical fiber fixture and further reduce the cost.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 projects an optical signal to a case and an optical fiber for projection which is housed and held in the case. A light emitting element, a light receiving element for receiving an optical signal from an optical fiber for receiving light, a photo IC in which an amplifying / signal processing circuit of the light receiving element and a drive circuit of the light emitting element are integrated, and a pin for external wiring. The printed circuit board has the connector, the light emitting element, and the photo IC mounted thereon. Further, as in the invention described in claim 2, a through hole is provided in which the optical fibers for projecting light and for receiving light are respectively inserted in the case, and the central axes thereof are aligned with the optical axes of the light emitting element or the photo IC. It is convenient to provide an optical fiber fixture for fixing the optical fibers inserted in the through hole. As described in claim 3, the optical fiber fixture has guide portions through which the light projecting and receiving light optical fibers respectively pass loosely, and the guide portions laterally of the guide portions are slightly smaller than the outer diameters of the respective optical fibers. It is preferable to use a plate having a small width and slits having V-shaped cross-sections on both sides thereof and configured to be movable in the lateral direction of the case.

Further, according to a fourth aspect of the present invention, the optical fiber fixture is a plate-like member which is configured to be movable in the lateral direction of the case, and the optical fiber for projecting light and the optical fiber for receiving light are respectively provided. Guides that are loosely penetrated, slits that have a width slightly smaller than the outer diameter of each optical fiber in the lateral direction of these guides, and have V-shaped cross-sections on both sides, and for moving the optical fiber fixture. And a through hole to be used, and the through hole is configured to have edge portions that are substantially orthogonal to the moving direction of the optical fiber fixture and that are substantially parallel to each other,
Correspondingly, the case has a wall portion having a guide portion formed on the surface along the moving direction of the optical fiber fixing tool, and the guide portion is provided at a portion facing the through hole of the optical fiber fixing tool. It is preferable that it is formed so as to have a substantially fan shape, and that the center portion of the arc diameter of this fan shape is located near the side end portion of the through hole of the optical fiber fixture.

[0010]

According to the first aspect of the present invention, the light receiving element, the amplification / signal processing circuit for the light receiving element, and the drive circuit for the light emitting element are integrated to form a photo IC. An electric circuit can be configured only with a connector having wiring pins, a printed circuit board on which the light emitting element and the photo IC are mounted. According to the second aspect of the present invention, optical fibers for projecting light and for receiving light are respectively inserted in the case, and the through holes are provided so that their central axes coincide with the optical axes of the light emitting element or the photo IC, and the through holes. Since an optical fiber fixture for fixing these optical fibers inserted in the optical fiber is provided, these optical fibers are brought into proper contact with the respective optical axes of the light emitting element and the photo IC and abutted,
It is fixed with an optical fiber fixture. In the invention according to claim 3, guide portions through which the optical fibers for projecting light and the optical fibers for receiving light respectively loosely pass through this optical fiber fixture, and in the lateral direction of these guide portions, the diameters are slightly smaller than the outer diameters of the respective optical fibers. The width of the plate is such that it is provided with a slit having V-shaped cross sections on both sides and is configured to be movable in the lateral direction of the case. After aligning the optical fibers, the optical fibers are inserted so as to abut the light emitting element and the photo IC, respectively, and the optical fiber fixture is further pushed in the lateral direction. Both sides of the cross section cut into the outer peripheral coating of these optical fibers and are fixed.

According to a fourth aspect of the present invention, the optical fiber fixture is a plate-shaped member that is movable in the lateral direction of the case, and the optical fibers for light projection and light reception are each loosely penetrated. Guides, slits having a width slightly smaller than the outer diameter of each optical fiber in the lateral direction of the guides, and having V-shaped cross-sections on both sides, and a penetrating hole used for moving the optical fiber fixture. Has a hole, and the through hole is substantially orthogonal to the moving direction of the optical fiber fixture,
In addition, the case is configured to have edges that are substantially parallel to each other, and correspondingly, the case has a wall portion in which the guide portion is formed on the surface along the moving direction of the optical fiber fixing tool. It is formed in a portion facing the through hole of the fiber fixing tool and has a substantially fan shape, and the center of the arc diameter of this fan shape is located near the side end of the through hole of the optical fiber fixing tool. Since the configuration is adopted, it becomes possible to move the optical fiber fixture required for attachment and detachment of the optical fiber as described below. That is, as the tool, for example, a tool such as a flat-blade screwdriver having a portion having a rectangular cross section is used. The tool is rotated by bringing one side edge of the rectangular portion into contact with the central portion of the radius of the arc of the guide portion and rotating the tool by the other side edge of the rectangular portion. It is possible to push either edge of the through hole of the. This makes it possible to move the optical fiber fixture without having to secure a space for moving work around the photoelectric converter.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. Embodiment 1; FIG. 1 shows a photoelectric converter according to an embodiment of the present invention corresponding to claims 1 to 3, and (a) is a transverse sectional view,
1B is a vertical sectional view taken along the line AA of FIG. 1A, and FIG.
It is a BB vertical cross-sectional view of (a). In FIG. 1, the photoelectric converter includes a case 3 having an open lower surface, and a light-emitting element 4 and a photo I that are inserted and held in upper housing chambers 31 and 32 integrally formed in the case 3, respectively.
C5, the printed circuit board 6 inserted into the case 3 from below and fixed, and connected to the connection terminals of the light emitting element 4 and the photo IC 5, and attached so as to cover a part of the side surface and the upper surface of the case 3. Cover 7 and cover 7
Through the side walls of the case 3 into the storage chambers 31 and 32 of the case 3 in the lateral direction, and the central axes thereof are inserted into through holes 33 and 34 provided in alignment with the optical axis of the light emitting element 4 or the photo IC 5, respectively. Abut
Optical fiber 8 for light projection fixed by an optical fiber fixture 9
1 and an optical fiber 82 for receiving light. The photo IC 5 has a light receiving element, and the light receiving element is amplified and
A signal processing circuit and a drive circuit for the light emitting element 4 are integrated. A connector 62 for external wiring and, if necessary, the light emitting element 4 and the photo I are provided at the end of the printed circuit board 6.
A C5 power supply circuit 61 is mounted, and this connector 62 is provided with a pin 63 for drawing out to the outside. FIG. 2 is a side view showing the details of the optical fiber fixing tool 9. The optical fiber fixing tool 9 has guide portions 91, 92 through which a light projecting optical fiber 81 or a light receiving optical fiber 82 is loosely penetrated, respectively.
And the optical fibers 8 in the lateral direction of the guide portions 91, 92.
The plate is provided with slits 93 and 94 each having a width slightly smaller than the outer diameter of 1, 82 and having V-shaped cross sections on both sides.

An optical fiber 81 for projecting light to this photoelectric converter
When attaching the optical fiber 82 for receiving light, first, as shown in FIG. 3A, the optical fiber fixture 9 is adjusted so that the guide portions 91, 92 are aligned with the through holes 33, 34 of the case 3. After being positioned, these optical fibers 81 or 82 are inserted so as to abut the light emitting element 4 and the photo IC 5, respectively, and further, as shown in FIG.
It is similar to (c). When the optical fiber fixing tool 9 is pushed in the lateral direction as shown in FIG. 4A), both sides of the V-shaped cross section of the slits 93, 94 of the optical fiber fixing tool 9 bite into the outer peripheral coating of the optical fibers 81, 82 and are fixed. To be done. Reference numeral 95 is a hole used when pulling out the optical fiber fixing tool 9. When removing the optical fibers 81 and 82 for projecting and receiving light, for example, a driver or the like is inserted into this hole, and the optical fiber fixing tool is The optical fiber 81, 82 is pulled out after the guide portions 91, 92 of 9 are pulled out so as to match the through holes 33, 34 of the case 3.

Optical fiber 82 for receiving light of this photoelectric converter
When the optical signal is transmitted to the optical IC 5, the optical signal enters the photo IC 5 where it is converted into an electric signal, amplified and signal-processed, and output from the connector 62. The electric signal input from the connector 62 is processed and amplified by the drive circuit of the photo IC 5, converted into an optical signal by the light emitting element 4, and emitted through the optical fiber 81 for emission. If only the conversion of the optical signal to the electric signal is required, the light emitting element 4 may be removed.

In this photoelectric converter, the electric circuit has a light emitting element 4
Since it is composed of only the photo IC 5 and the printed circuit board 6, the number of parts of the electric circuit is small, the size is reduced, and the cost is reduced. In addition, the photodetector which is susceptible to noise from the outside and the amplification / signal processing circuit of this photodetector are the photo ICs 5.
Since it is integrated as, and enclosed in, for example, a conductive IC case, it is not affected by electromagnetic interference from the outside.

Further, since the optical fiber fixture 9 is made of one plate as described above, the cost is further reduced. Embodiment 2; FIG. 4 shows a photoelectric converter according to an embodiment of the present invention corresponding to claims 1, 2 and 4, (a) is a side view thereof, and (b) is an R in FIG. 4 (a). FIG. 5 is a view taken in the direction of an arrow, and FIG. 5 is a side view of the optical fiber fixture shown in FIG. 4. 6 shows a sectional structure of the photoelectric converter according to FIG. 4, where (a) is a sectional view taken along line CC of FIG. 4 (b), and (b) is FIG. 6 (a).
6 is a sectional view taken along line DD in FIG. FIG. 7 is a sectional view taken along line EE in FIG. 8 is an explanatory view for explaining a method of moving the optical fiber fixture of the photoelectric converter according to FIGS. 4 to 7 when fixing the optical fiber, and FIG. 9 is a photoelectric converter according to FIGS. 4 to 7. FIG. 6 is an explanatory diagram for explaining a moving method of the optical fiber fixing tool in FIG. 4 to 9, in FIGS.
The same parts as those of the photoelectric converter according to the embodiment of the present invention corresponding to claims 1 to 3 are given the same reference numerals and the description thereof will be omitted. 8 and 9, the shape of the bottomed hole formed in the case of the photoelectric converter according to FIGS. 4 to 7 is partially simplified. In addition, in FIGS.
Regarding the reference numerals given in FIGS. 1 to 3, only representative reference numerals are shown.

In FIGS. 4 to 7, reference numeral 1A designates FIGS.
In the photoelectric converter according to the present invention shown in FIG. 5, a case 3A, a cover 7A, and an optical fiber fixing tool 9A are used instead of the case 3, the cover 7, and the optical fiber fixing tool 9, respectively. is there. The optical fiber fixture 9A is different from the optical fiber fixture 9 shown in FIG.
The through hole 96 is used instead of the through hole 95. The through hole 96 is a hole used for moving the optical fiber fixture 9A when the light projecting optical fiber 81 and the light receiving optical fiber 82 are attached and detached, and enables insertion of a tool described later. It is a thing. The through hole 96 has a rectangular shape, and has edges 96a and 96b which are orthogonal to the moving direction of the optical fiber fixture 9A (shown by an arrow in FIG. 5) and are parallel to each other.

The case 3A is the case 3 according to FIGS.
On the other hand, in addition to having a substantially rectangular parallelepiped outer shape,
The wall portion 35 is provided at a portion where the optical fiber fixture 9A is inserted. The wall portion 35 has a surface 35a along the moving direction of the optical fiber fixture 9A, and a substantially fan-shaped bottomed hole 36 which is a guide portion is formed from the surface 35a. In the bottomed hole 36, the central part of the circular arc diameter of the fan shape is
It is set so as to be located near one side end portion 96c of the through hole 96 formed in the optical fiber fixture 9A. The lower wall portion 37 of the case 3A is used for mounting the photoelectric converter 1A on a circuit board (not shown),
A mounting bracket 38 having an internal thread 38a is provided. The cover 7A is formed in a shape that covers the case 3A in a U-shape from the side surface and covers most of the upper surface of the case 3A.

The photoelectric converter 1A according to the second embodiment shown in FIGS. 4 to 7 has the above-mentioned structure, and the main difference from the photoelectric converter according to the present invention shown in FIGS. This is a method of moving the optical fiber fixture 9A when attaching and detaching the fibers 81 and 82. Next, a method of moving the optical fiber fixture 9A in the photoelectric converter 1A will be described with reference to FIGS. First, the optical fibers 81 and 82
When installing, the slit 9 of the optical fiber fixture 9A
Both sides of the V-shaped cross section of 3,94 are provided with optical fibers 81,82.
It is necessary to fix the optical fibers 81 and 82 by digging into the outer peripheral coating of the above. At that time, as shown in FIG.
For example, the tip portion 99 of a minus driver is used to move the optical fiber fixture 9A in the direction of the arrow in FIG. That is, the flat rectangular tip of a flat-blade screwdriver is passed through the through hole 96 and then inserted into the bottomed hole 36, and one side edge 99a of the rectangular portion is inserted into the bottomed hole 36. It is brought into contact with the center portion of the circular arc diameter of the fan shape and rotated in the clockwise direction. Then, the other side edge portion 99b of the rectangular portion of the tip portion 99 of the minus driver presses the edge portion 96b of the through hole 96 in the direction of the arrow. As a result, the optical fiber fixture 9A is moved in the direction of the arrow, and the optical fibers 81 and 82 are fixed.

When removing the optical fibers 81 and 82, the optical fibers 81 and 82 are fixed by the optical fiber fixture 9A.
It is necessary to release the fixed state of the
As shown in FIG.
9 is used to move the optical fiber fixture 9A in the direction of the arrow in FIG. That is, the side edge 99a of the rectangular tip end of the minus driver is brought into contact with the center portion of the radius of the arc of the fan-shaped bottomed hole 36, and is rotated counterclockwise. Then, the side edge 99b of the rectangular portion of the minus driver 99 presses the edge 96a of the through hole 96 in the direction of the arrow. As a result, the optical fiber fixture 9A is moved in the direction of the arrow, and the fixation of the optical fibers 81 and 82 is released.

When fixing and releasing the fixing of the optical fibers 81 and 82, the photoelectric converter 1A is located above (above the upper end of the optical fiber fixture 9A in FIG. 9). Does not need space. That is, the photoelectric converter 1A has the same action and effect as the photoelectric converter according to the present invention shown in FIGS. 1 to 3, and can further reduce the spatial distance between adjacent devices. .

In the above description of the second embodiment, the guide portion formed in the case 3A of the photoelectric converter 1A is the bottomed hole 36, but the present invention is not limited to this, and for example, the penetrating It may be a hole.
Further, in the above description of the second embodiment, the tool used for fixing and releasing the fixing of the optical fibers 81, 82 is the minus driver, but the tool is not limited to this, and the rectangular portion is not limited thereto. If you have
Of course, it need not be a minus driver.

[0023]

In the photoelectric converter of the present invention, the number of parts of the electric circuit is reduced, so that the size is small and the cost is low. Further, the structure of the optical fiber fixing device is simplified and the cost is reduced because it is made of one plate. Is further reduced. In addition, the optical fibers 81 and 8 can be provided even if they are not provided with a space distance between them adjacent to each other.
Since 2 can be fixed and the fixing can be released, the device in which the photoelectric converter is mounted can be downsized.

[Brief description of drawings]

FIG. 1 shows a photoelectric converter according to an embodiment of the present invention,
1A is a horizontal sectional view, FIG. 1B is a vertical sectional view taken along the line AA of FIG. 1A, and FIG. 1C is a vertical sectional view taken along the line BB of FIG.

FIG. 2 is a side view showing details of the optical fiber fixture shown in FIG.

FIG. 3 shows a method of mounting the light projecting and light receiving optical fibers, and FIG. 3 (a) is a longitudinal sectional view when these optical fibers are inserted into through holes of a case,
(B) is a longitudinal sectional view when these optical fibers are fixed by an optical fiber fixing tool.

4A and 4B show a photoelectric converter according to another embodiment of the present invention, FIG. 4A is a side view thereof, and FIG. 4B is a view taken in the direction of arrow R in FIG. 4A.

FIG. 5 is a side view of the optical fiber fixture shown in FIG.

6 shows a cross-sectional structure of the photoelectric converter according to FIG.
6A is a cross-sectional view taken along the line CC of FIG. 4B, and FIG. 6B is a cross-sectional view taken along the line D-D of FIG.

FIG. 7 is a sectional view taken along line EE in FIG.

FIG. 8 is an explanatory view for explaining a moving method of the optical fiber fixture of the photoelectric converter according to FIGS. 4 to 7 when fixing the optical fiber.

FIG. 9 is an explanatory view for explaining a method of moving the optical fiber fixture of the photoelectric converter according to FIGS. 4 to 7 when the optical fiber is unfixed.

FIG. 10 is a vertical sectional view showing an example of a conventional photoelectric converter.

11 is a front view of the guide groove as seen from the direction of arrow P in FIG.

[Explanation of symbols]

 3 Case 33 Through Hole 34 Through Hole 4 Light Emitting Element 5 Photo IC 6 Printed Circuit Board 62 Connector 81 Light Emitting Optical Fiber 82 Light Receiving Optical Fiber 9 Optical Fiber Fixture 91 Guide Part 92 Guide Part 93 Slit 94 Slit

Claims (4)

[Claims] 1. A case, a light emitting element for projecting an optical signal to a light projecting optical fiber housed and held in the case, a light receiving element for receiving an optical signal from the light receiving optical fiber, and the light receiving element. A photo IC in which the amplification / signal processing circuit and the drive circuit for the light emitting element are integrated, a connector having a pin for external wiring, and a printed circuit board on which the light emitting element and the photo IC are mounted. And photoelectric converter. 2. The photoelectric converter according to claim 1, wherein light-transmitting and light-receiving optical fibers are respectively inserted in the case, and the central axes thereof are provided so as to coincide with the optical axes of the light emitting element or the photo IC. And a through hole and an optical fiber fixture for fixing the optical fibers inserted in the through hole. 3. The photoelectric converter according to claim 2, wherein the optical fiber fixture has guide portions through which the light-transmitting and light-receiving optical fibers respectively pass loosely, and the optical fibers in the lateral direction of these guide portions. A photoelectric converter comprising a plate having a width slightly smaller than the outer diameter of the case and having V-shaped cross-sections on both sides thereof and configured to be movable in the lateral direction of the case. 4. The photoelectric converter according to claim 2, wherein the optical fiber fixture is a plate-shaped member that is movable in the lateral direction of the case, and the optical fibers for projecting light and the optical fibers for receiving light are respectively provided. Guides that are loosely penetrated, slits that have a width slightly smaller than the outer diameter of each optical fiber in the lateral direction of these guides, and have V-shaped cross-sections on both sides, and for moving the optical fiber fixture. A through hole to be used, and the through hole has edges that are substantially orthogonal to the moving direction of the optical fiber fixing tool and are substantially parallel to each other, and the case is a moving direction of the optical fiber fixing tool. Has a wall formed with a guide portion on the surface along with, and this guide portion is formed in a portion facing the through hole of the optical fiber fixing tool, has a substantially fan shape, and has a circular arc shape of this fan shape. The center of the diameter is the optical fiber The photoelectric converter characterized by comprising located near a side end portion of the through hole tool has.