JP2004020894A - Optical transceiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability of optical communication connection by reducing optical connection loss between POF and a light receiving and emitting element module. <P>SOLUTION: A module housing 26 in which a tip end section of a module ferrule 29 is connected to ferrule storage sections 34a and 34b, is stored into a shield case 35 so that a groove section 29e of the ferrule 29 is engaged with notched parts 35a and 35b of the case 35. Thus, the stored housing 26 is pressed against the ferrule 29 side by a spring piece 19 of the case 35. No gap therefore is formed between the tip end surface of the ferrule 29 and the front surfaces of module storage sections 26a and 26b and both surfaces are tightly contacted with each other. As a result, optical connection reliability of a signal receiving module 24, a signal transmitting module 25 and a repeater POF 27 is improved. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical transceiver that couples an optical fiber such as a POF (Plastic Optical Fiber) used in a high-speed optical LAN (Local Area Network) for automobiles and a light receiving / emitting element.
[0002]
[Prior art]
FIG. 4 is a schematic diagram showing a part of a basic configuration of an optical communication system such as an optical LAN system. As shown in FIG. 4, in the optical communication system, one device 100 and the other device (not shown) are interconnected via a POF 140. The POF 140 and one device 100 and the other device are interfaced by an optical transceiver 120 mounted on a unit substrate 150. The POF 140 is appropriately relayed by a relay connector (not shown) including a first connector (for example, a plug connector) and a second connector (for example, a receptacle connector), and transmits an optical signal to an arbitrary distance.
[0003]
Here, the optical transceiver 120 includes a connector portion 123 including a second connector (receptacle connector (female connector)) 121 into which a first connector (plug connector (male connector)) 122 is fitted, and a receiving module (light receiving device). The light emitting / receiving element module section 126 includes an element) 124 and a transmission module (light emitting element) 125, and a relay POF 127 that relays the connector section 123 and the light receiving / emitting element module section 126. The second connector 121 of the connector section 123 is a connector for connecting the light emitting / receiving element module section 126 and the POF 140 via the relay POF 127.
[0004]
As described above, the second connector 121 and the light receiving / emitting element module section 126 are separated from each other by the relay POF 127, so that the receiving module 124 and the transmitting module 125 are located near the communication IC 130 mounted on the unit substrate 150. And the wiring length between the modules 124 and 125 and the communication IC 130 can be shortened, so that the device 100 that is advantageous in terms of noise generated by high-frequency communication can be configured. . A connector ferrule 128 is attached to a terminal portion of the relay POF 127 on the connector portion 123 side, and a module ferrule 129 is attached to a terminal portion of the relay light emitting / receiving element module portion 126 side. A ferrule 141 is attached to the terminal section on the 122 side.
[0005]
FIG. 5 is a cross-sectional view showing a connection structure between the light emitting / receiving element module portion 126 and the module ferrule 129 in the optical transceiver 120. As shown in FIG. 5, a module housing 131 constituting the light receiving / emitting element module portion 126 has a receiving module 124 and a transmitting module 125 built therein, and a space on the front surface into which the tip of the module ferrule 129 is inserted. 132 is formed, and the ferrule fitting portion 134 in which the hole 133 communicating with the space 132 is formed is configured to protrude from the inside of the metal shield case 135 to the outside.
[0006]
The module ferrule 129 has a fiber insertion hole 136 into which the relay POF 127 is inserted, and the relay POF 127 is also inserted into the distal end of the module ferrule 129 so that the distal end face and the end face of the relay POF 127 are in the same position. Further, a protrusion 137 that fits into the hole 133 of the ferrule fitting portion 134 is formed at a predetermined position on the outer peripheral wall near the distal end portion.
[0007]
In the structure of the optical transceiver 120 configured as described above, the outer diameter of the distal end of the module ferrule 129 is adjusted so that the distal end of the module ferrule 129 and the space 132 of the ferrule fitting portion 134 are fitted to each other. The ferrule fitting portion 134 is formed such that the inner diameter of the space 132 is the same as the inner diameter of the ferrule fitting portion 134.
[0008]
[Problems to be solved by the invention]
However, in the connection between the light emitting / receiving element module portion 126 and the module ferrule 129 having such a structure, the connection accuracy is improved by a simple fitting of the projection 137 of the module ferrule 129 and the hole 133 of the module fitting portion 134. Because of this, due to a fitting error or a dimensional error between the projection 137 and the hole 133, a front end face of the module ferrule 129 (in other words, an end face of the relay POF 127) and a front face of the light emitting / receiving element module section 126 are formed. In some cases, a gap A may occur between the two. In this case, there is a problem that the optical connection loss between the relay POF 127 and the light emitting / receiving element module unit 126 increases, and as a result, the reliability of the optical communication decreases.
[0009]
SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an optical transceiver capable of reducing optical connection loss between a POF and a light receiving / emitting element module and improving connection reliability of optical communication. The purpose is to provide.
[0010]
[Means for Solving the Problems]
A first optical transceiver according to the present invention includes: a module housing in which a photoelectric conversion element that performs a conversion operation between an optical signal and an electric signal is built; a metal shield case that houses the module housing therein; A module ferrule attached to one end of an optical fiber optically coupled to the photoelectric conversion element and coupled to the module housing, wherein the module housing includes a tip of the module ferrule. The module includes a ferrule fitting portion whose surface is fitted so as to be in contact with the photoelectric conversion element, and the module ferrule includes the optical fiber, the end face of the optical fiber having the same position as the tip face of the module ferrule. And a fiber receiving hole formed at a predetermined position on the outer wall along the outer periphery. The shield case has a notch part fitted with the module ferrule, and the edge of the notch fits with the flange part of the module ferrule, and the edge part is the edge part. It is characterized by comprising a spring portion that presses the module housing toward the module ferrule in a state where the module housing is fitted to the flange portion.
[0011]
According to the first optical transceiver of the present invention, the notch of the shield case and the module ferrule are fitted so that the edge of the notch fits with the flange of the module ferrule, and the module ferrule is shielded. While being fixed to the case, the module housing in which the module ferrule is fitted is pressed toward the module ferrule by the spring portion of the shield case. For this reason, a gap is less likely to be generated between the photoelectric conversion element built in the module housing and the optical fiber housed in the module ferrule, thereby improving the connection reliability of optical communication. .
[0012]
A second optical transceiver according to the present invention includes: a module housing in which a photoelectric conversion element that performs a conversion operation between an optical signal and an electric signal is built; a metal shield case that houses the module housing therein; A relay fiber for optically relaying the photoelectric conversion element and an external optical fiber, a second connector fitted to a first connector attached to an end of the external optical fiber, and the relay fiber A module ferrule attached to one end of the relay fiber and coupled to the module housing; and a connector ferrule attached to the other end of the relay fiber and coupled to the second connector. The module housing is fitted with a ferrule so that a tip end surface of the module ferrule comes into contact with the photoelectric conversion element. The module ferrule has a fiber accommodation hole for accommodating the relay fiber such that the end face of the relay fiber is at the same position as the tip end face of the module ferrule, and has an outer wall part. A flange formed at a predetermined position along the outer periphery, the shield case includes a cutout portion fitted with the module ferrule, and an edge of the cutout portion has a flange portion of the module ferrule. A fitting is provided, and a spring portion is provided for pressing the module housing toward the module ferrule in a state where the edge portion is fitted to the flange portion.
[0013]
According to the second optical transceiver of the present invention, the notch of the shield case and the module ferrule are fitted so that the edge of the notch fits with the flange of the module ferrule, and the module ferrule is shielded. While being fixed to the case, the module housing in which the module ferrule is fitted is pressed toward the module ferrule by the spring portion of the shield case. For this reason, it is difficult for a gap to be generated between the photoelectric conversion element built in the module housing and the relay fiber housed in the module ferrule, thereby making it possible to improve the connection reliability of optical communication. .
[0014]
The module ferrule and the connector ferrule are preferably ferrules having the same shape. In this case, it is preferable that both ferrules are made of metal or resin. If they have the same shape, it is possible to promote the common use of parts and reduce costs.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an exploded perspective view showing components constituting an optical transceiver according to an embodiment of the present invention, and FIG. 2 is a side sectional view showing a part of the optical transceiver.
As shown in FIG. 1, the optical transceiver 1 includes a module housing 26 in which a receiving module (light receiving element) 24 and a transmitting module (light emitting element) 25 as photoelectric conversion elements are respectively built, and the module housing 26 is covered. A relay for optically relaying the shield case 35 housed therein, the receiving module 24 and the transmitting module 25 built in the module housing 26, and an external plastic optical fiber (hereinafter referred to as “POF”) 40. A second connector (for example, a plug connector) 22 that fits a plastic optical fiber (hereinafter, referred to as a “relay POF”) 27 and a first connector (for example, a plug connector) 22 that accommodates an external POF 40 having an end attached to a ferrule 41. (For example, receptacle connector) 21 and relay POF 27 And a module ferrule 29 attached to the other end and coupled to the module housing 26, and a connector ferrule 28 attached to the other end of the relay POF 27 and coupled to the receptacle connector 21. I have.
[0016]
The module housing 26 is made of, for example, a resin molded member. The module housings 26a and 26b that house the reception module 24 and the transmission module 25 therein, respectively, and a connection side between the module housings 26a and 26b and the module ferrule 29 are provided. It is integrally formed so as to protrude, and is provided with sleeve-shaped ferrule accommodation portions 34a and 34b in which the distal ends of the module ferrules 29 are inserted and accommodated, respectively.
[0017]
The shield case 35 is formed by molding a material such as a thin metal plate into a box shape by press working or the like. U-shaped cutouts 35a and 35b are respectively formed in the wall 35c. In this example, a groove portion of a module ferrule 29 described later is fitted to the notches 35a and 35b. As shown in FIG. 3, the wall 35d located on the side opposite to the wall 35c on the side where the notches 35a and 35b are formed is cut so that three continuous sides enter the internal space of the shield case 35. A plurality of bent rectangular spring pieces 19 are formed.
[0018]
As shown in FIG. 2, the relay POF 27 has a structure in which a central fiber 27a is covered with a covering portion 27b, and the covering portion 27b is removed on the distal end side in the connection direction with the module housing 26. The fiber strand 27a is directly fixed to the inner surface of the fiber insertion hole 29d of the module ferrule 29 with, for example, an adhesive. The covering 27b is similarly removed from the front end side in the connection direction with the receptacle connector 21, and the fiber strand 27a is directly fixed to the inner surface of the fiber insertion hole (not shown) of the connector ferrule 28 with an adhesive or the like. ing.
[0019]
The receptacle connector 21 has a concave connector fitting portion 12 formed on the fitting side of the plug connector 22 with the connector housing 11 of the plug connector 22 and having a shape conforming to the outer shape of the connector housing 11. On the connection side with the relay POF 27, a connector housing 14 in which a relay POF accommodating portion 13 for accommodating the relay POF 27 having a connector ferrule 28 mounted thereon is formed, and a connector ferrule 28 accommodated in the relay POF accommodating portion 13 is provided as an exterior. The end portion of the relay POF 27 is formed of a coil-shaped spring 42 and a stopper member 43 serving as a mounting member of the relay POF 27 for positioning and fixing the relay POF 27 in the connector housing 14.
[0020]
An end of the spring 42 on the connector housing 14 side is in contact with a flange 28 a formed along a periphery at a predetermined position on an outer wall of the connector ferrule 28, and the other end is a base end of the stopper member 43. 43a. The stopper member 43 is formed with an engagement claw 16 for engaging with the engagement protrusion 15 formed on the outer wall of the relay POF accommodating portion 13 and attaching and fixing the stopper member 43 to the connector housing 14. The connector ferrule 28 housed in the relay POF housing 13 by the spring 42 and the stopper member 43 is always housed in a state of being pressed toward the plug connector 22. Further, the connector housing 14 accommodates a plurality of connection terminals 17 for electrical connection. In this example, the receptacle connector 21 is a so-called hybrid connector capable of optical connection and electrical connection, but a normal optical connection connector may be used.
[0021]
On the other hand, the plug connector 22 accommodates the end of the POF 40 on which the ferrule 41 is externally accommodated, and accommodates a plurality of crimp terminals 18 to which electric wires (not shown) are crimped. And a fixing member 50 for positioning and fixing the ferrule 41 and the crimp terminal 18. After inserting the ferrule 41 and the crimp terminal 18 into the ferrule insertion hole 11a and the terminal insertion hole 11b formed in the connector housing 11, respectively, the fixing member 50 is attached to the fixing member attaching portion 11c, so that the ferrule 41 and the crimp terminal 18 are It is fixed to the plug connector 22.
[0022]
The module ferrule 29 is made of a material such as metal or resin. In this example, the ferrule 29 includes a plurality of flanges 29a and 29b formed along the outer circumference at predetermined positions on an outer wall of a cylindrical main body. As shown in FIG. 2, it has a structure in which fiber insertion holes 29c and 29d for housing the relay POF 27 are formed. A groove 29e that fits into the cutouts 35a and 35b of the shield case 35 is formed in the outer wall portion sandwiched between the flanges 29a and 29b. The fiber insertion hole 29c has an inner diameter corresponding to the outer diameter of the relay POF 27 so as to be able to accommodate the covering portion 27b of the relay POF 27, and the fiber insertion hole 29d is for accommodating the fiber strand 27a of the relay POF 27. It is formed to have an inner diameter smaller than the inner diameter of the fiber insertion hole 29c and to match the outer diameter of the fiber strand 27a. In this example, the connector ferrule 28 is formed in the same shape and the same configuration as the module ferrule 29 described above, and thus the description is omitted here. Further, here, the description has been made using the module ferrule 29 in which the plurality of flanges 29a and 29b and the groove 29e are formed. However, for example, only one flange 29b may be formed. In this case, the module ferrule 29 is fitted to the notches 35a and 35b, and the flange 29b is fitted to fit the edges of the notches 35a and 35b on the inner space side of the shield case 35. .
[0023]
As shown in FIG. 2, a module ferrule 29 is attached to an end of the relay POF 27 on the module housing 26 side, and the distal end of the module ferrule 29 has a ferrule accommodating portion 34 a of the module housing 26. 34b, it is accommodated in such a manner that its front end surface contacts the front surfaces of the module accommodating portions 26a, 26b accommodating the receiving module 24 and the transmitting module 25, respectively. The length from the insertion end face 29f of the flange part 29b of the module ferrule 29 to the tip end face is the length from the opening end face 34f of the ferrule accommodation parts 34a, 34b to the connection surface 34g with the module accommodation parts 26a, 26b. It is formed to be the same as The relay POF 27 is housed in the fiber insertion hole 29d through the fiber insertion hole 29c such that the end face of the module ferrule 29 and the end face of the fiber strand 27a of the relay POF 27 are located at the same position. Between the end face of the module housing portions 26a and 26b and the front surfaces of the module housing portions 26a and 26b.
[0024]
By using the module housing 26, the module ferrule 29, and the shield case 35 configured as described above, a gap is generated between the end surface of the relay POF 27 and the front surfaces of the module housing portions 26a and 26b, as described below. The connection between the receiving module 24 and the transmitting module 25 and the relay POF 27 can be achieved without using the relay module. That is, the distal end of the module ferrule 29 in which the relay POF 27 is accommodated is inserted into the ferrule accommodating portions 34a and 34b of the module housing 26, and the module ferrule 29 is connected to the module housing 26. Then, the module housing 26 to which the module ferrule 29 is connected is inserted into the shield case 35 so that the groove 29e of the module ferrule 29 fits into the notches 35a and 35b of the shield case 35.
[0025]
The module housing 26 inserted into the shield case 35 is pressed by the spring piece 19 of the shield case 35 in the direction of the module ferrule 29 fitted into the cutouts 35a and 35b. When the module housing 26 is pressed in this manner, the end surface of the flange portion 29b of the module ferrule 29 in the direction of the flange portion 29a in which the groove portion 29e is fitted into the notch portions 35a, 35b is the edge of the notch portions 35a, 35b of the shield case 35. Abutting against the wall surfaces of the module housing 26 and the end surfaces of the module housing 26 on the ferrule housing portions 34a and 34b side. Further, the front end surface of the module ferrule 29 and the front surfaces of the module housing portions 26a and 26b are in close contact with each other. As a result, the module ferrule 29 and the module housing 26 are positioned and fixed in the shield case 35 in a state where a gap hardly occurs between the end surface of the relay POF 27 and the front surfaces of the module housing portions 26a and 26b.
[0026]
Therefore, the optical connection reliability between the receiving module 24 and the transmitting module 25 and the relay POF 27 can be remarkably improved as compared with the conventional case where the gap A (see FIG. 5) occurs. Further, the module housing 26 and the module ferrule 29 are constantly urged in the direction of the wall 35c of the shield case 35 by the spring pieces 19 of the shield case 35. The possibility that the optical connection reliability with the POF 27 is reduced is reduced. Further, in this example, since the module ferrule 29 and the connector ferrule 28 are common parts having the same shape or the like, the common use of the parts can be promoted, and the cost can be reduced.
[0027]
【The invention's effect】
As described above, according to the first optical transceiver of the present invention, the notch of the shield case and the module ferrule are fitted so that the edge of the notch fits with the flange of the module ferrule. The module ferrule is fixed to the shield case, and the module housing in which the module ferrule is fitted is pressed toward the module ferrule by the spring portion of the shield case. For this reason, a gap is less likely to be generated between the photoelectric conversion element built in the module housing and the optical fiber housed in the module ferrule, thereby improving the connection reliability of optical communication. This has the effect.
[0028]
According to the second optical transceiver of the present invention, the notch of the shield case and the module ferrule are fitted so that the edge of the notch fits with the flange of the module ferrule. Is fixed to the shield case, and the module housing in which the module ferrule is fitted is pressed toward the module ferrule by the spring portion of the shield case. For this reason, it is difficult for a gap to be generated between the photoelectric conversion element built in the module housing and the relay fiber housed in the module ferrule, thereby making it possible to improve the connection reliability of optical communication. .
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing components constituting an optical transceiver according to an embodiment of the present invention.
FIG. 2 is a side sectional view showing a part of the optical transceiver.
FIG. 3 is a perspective view showing a part of the optical transceiver.
FIG. 4 is a schematic diagram showing a part of a basic configuration of an optical communication system such as an optical LAN system.
FIG. 5 is a cross-sectional view showing a connection structure between a light receiving / emitting element module part and a module ferrule in the optical transceiver of the optical communication system.
DESCRIPTION OF SYMBOLS 1 ... optical transceiver, 11 and 14 ... connector housing, 12 ... connector fitting part, 13 ... relay POF accommodation part, 15 ... engaging projection, 16 ... engaging claw, 17 ... connection terminal, 18 ... Crimp terminal, 19: spring piece, 21: receptacle connector, 22: plug connector, 24: receiving module, 25: transmitting module, 26: module housing, 26a, 26b: module housing part, 27: relay POF, 27a: fiber element Wire, 27b: covering portion, 28: connector ferrule, 28a, 28b, 29a, 29b: flange portion, 29: module ferrule, 29c, 29d: fiber insertion hole, 29e: groove portion, 34a, 34b: ferrule housing portion, 35: Shield case, 35a, 35b: Notch, 40: POF, 41: Ferrule, 42: Split Grayed, 43 ... stopper, 50 ... fixing member.

Claims (4)

A module housing containing a photoelectric conversion element that performs a conversion operation between an optical signal and an electric signal,
A metal shield case for housing the module housing inside,
A module ferrule attached to one end of an optical fiber optically coupled to the photoelectric conversion element and coupled to the module housing,
The module housing includes a ferrule fitting portion that is fitted so that a distal end surface of the module ferrule comes into contact with the photoelectric conversion element,
The module ferrule has a fiber accommodation hole for accommodating the optical fiber so that the end face of the optical fiber is at the same position as the tip end face of the module ferrule, and along the outer periphery at a predetermined position of the outer wall portion. With a formed collar,
The shield case includes a cutout portion fitted with the module ferrule, an edge of the cutout portion is fitted with a flange portion of the module ferrule, and the edge portion is fitted with the flange portion. An optical transceiver comprising a spring portion for pressing the module housing toward the module ferrule in a state. A module housing containing a photoelectric conversion element that performs a conversion operation between an optical signal and an electric signal,
A metal shield case for housing the module housing inside,
A relay fiber for optically relaying the photoelectric conversion element and an external optical fiber,
A second connector fitted with a first connector attached to an end of the external optical fiber;
A module ferrule attached to one end of the relay fiber and coupled to the module housing;
A connector ferrule attached to the other end of the relay fiber and coupled to the second connector,
The module housing includes a ferrule fitting portion that is fitted so that a distal end surface of the module ferrule comes into contact with the photoelectric conversion element,
The module ferrule has a fiber accommodation hole for accommodating the relay fiber so that the end face of the relay fiber is located at the same position as the tip face of the module ferrule, and along a periphery at a predetermined position of the outer wall portion. With a formed collar,
The shield case includes a cutout portion fitted with the module ferrule, an edge of the cutout portion is fitted with a flange portion of the module ferrule, and the edge portion is fitted with the flange portion. An optical transceiver comprising a spring portion for pressing the module housing toward the module ferrule in a state. The optical transceiver according to claim 2, wherein the module ferrule and the connector ferrule are ferrules having the same shape. 4. The optical transceiver according to claim 2, wherein the module ferrule and the connector ferrule are made of metal or resin.

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