JP3378192B2 - Optical connector plug and optical connector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug of an optical connector provided on the end side of an optical fiber cable, a plug of the optical connector (hereinafter, also simply referred to as "plug"), and an optical connector engaging with the plug. Optical connector including a socket (hereinafter, also simply referred to as “socket”).

[0002]

2. Description of the Related Art An optical fiber cable with a conventional optical connector plug has an end face of the optical fiber cable as the end face of the plug, so that the end face is not damaged. The protective cap as disclosed in Japanese Patent Laid-Open Publication was inserted and carried.

[0003]

Therefore, in the conventional plug of the optical connector, a laborious work such as attaching and detaching the protective cap is required. Also,
There is also a concern that the protective cap will be lost, and if it is actually lost, there is a risk that the end face of the optical fiber cable may be damaged if another protective cap cannot be prepared. Furthermore, there is a risk of forgetting to attach the protective cap, and in that case, there is also a risk of damaging the end face of the optical fiber cable.

On the other hand, when the plug of the optical connector is engaged with the socket, in order to improve the light transmission efficiency (signal transmission efficiency), and when a slight external pressure is applied to the plug of the optical connector, the optical connector is not connected to the socket. In order to prevent uninterrupted signal transmission, the distance dimension between the front surface of the optical element (light emitting element or light receiving element) in the socket and the end surface of the optical fiber cable is set small. Therefore, when the plug of the optical connector is attached to the socket in an improper manner, or due to external pressure from the surrounding area after installation or due to expansion or contraction of the optical fiber cable due to changes in operating temperature, etc. There is a possibility that the front surface side of the optical element may come into contact.

In particular, in the case of an optical connector plug using a plastic optical fiber cable, the optical element on the socket side at that time is made of a resin mold, whether it is a lens type or a lensless type. Is. On the other hand, on the end face side of the plastic optical fiber cable, which is the tip side of the plug, there is a ferrule (tube) made of a material that is stronger than this plastic optical fiber cable from the fixed area on the end side of the plastic optical fiber cable. After removing the coating, the outer periphery is usually covered up to the end face. Therefore, when the ferrule comes into contact with the front surface side of the optical element, scratches are easily formed. Such scratches must be avoided in order to properly secure the light transmission efficiency (signal transmission efficiency).

A main object of the present invention is to provide an optical connector plug having a function of protecting an end face of an optical fiber cable, and an optical connector comprising the plug of the optical connector and a socket of the optical connector engaging with the plug. To do.

[0007]

In order to solve the above problems, the plug of the optical connector according to the present invention is provided on the end side of the optical fiber cable and engages with the socket of the optical connector. A housing part fixed to the end side, and a ferrule slidably protruding from the housing part along the optical fiber cable and detachably engaged with the insertion hole part of the socket; The optical fiber cable has an elastic body portion that biases the ferrule toward the tip side thereof, and the optical fiber cable has a sliding contact portion with the ferrule having a dimension longer than the dimension along the optical fiber cable of the ferrule on the end side thereof. , The ferrule is not in a predetermined engagement state with the socket, and the ferrule is in a state in which the ferrule is not subjected to an external pressure in a direction toward the base end side thereof that is greater than a predetermined value. The end face of the optical fiber cable is stored inside the ferrule with respect to the end face of the ferrule when the ferrule is biased by the elastic body portion, and the ferrule is in a predetermined engagement state with the socket. Or the end face of the optical fiber cable is capable of protruding by a predetermined dimension from the end face of the ferrule when the ferrule is subjected to an external pressure of a predetermined amount or more in the proximal direction. Is characterized by.

Therefore, in the case of the plug of the optical connector according to the present invention, the state where the plug is not used (specifically, the state where the ferrule of the plug is not brought into a predetermined engagement state with the socket) and the ferrule of the plug is When the ferrule is biased by the elastic body portion in the state where the ferrule is not subjected to an external pressure of a predetermined amount or more in the proximal direction, the end face of the optical fiber cable is stored inside the ferrule with respect to the tip face of the ferrule.

Therefore, for example, when the optical fiber cable with a plug is conveyed, the end surface of the optical fiber cable is exposed unless the ferrule receives an external pressure in excess of the force biased by the elastic body portion toward the base end side of the ferrule. Therefore, it is possible to make the end face difficult to contact with an external object. Therefore, in the case of the plug of the optical connector according to the present invention, if the force urged by the elastic body portion is appropriately set in relation to the external pressure, it is basically possible to carry out the above-mentioned operation even without a protective cap during transportation. There is no risk of scratching the end face.

On the other hand, when the ferrule is in a predetermined engagement state with the socket, that is, when the plug is engaged with the insertion hole of the socket, the end surface of the optical fiber cable is more predetermined than the front end surface of the ferrule. It can be projected (exposed) by the dimension of. Therefore, in the predetermined engagement state, the end surface of the optical fiber cable can be arranged in front of the front surface of the optical element on the socket side by a minute predetermined dimension. At the same time, the end face of the optical fiber cable is pushed out to the front side of the optical element on the socket side from the front end face of the ferrule, so that the front side of the optical element on the socket side is positioned by the ferrule that is positioned behind the end face. There is no risk of being damaged.

It should be noted that the minute predetermined size can be made smaller than in the conventional case because the front side of the optical element on the socket side is not damaged by the ferrule. In addition, considering that it will not be damaged, the light transmission efficiency (signal transmission efficiency) can be improved more than before.

Further, when the user wants to clean the end face of the optical fiber cable, for example, if the ferrule receives the external pressure of a predetermined amount or more in the proximal direction, the end face is exposed. Since it can be cleaned, it can be cleaned.

By the way, the socket of the optical connector which engages with the plug of the optical connector according to the present invention has, for example, an insertion hole portion into which the front end side of the ferrule of the plug of the optical connector is inserted, and the insertion hole portion communicates with the insertion hole portion. The optical element fixed to the element fixing part room provided on the back side of the insertion hole is provided, and the back side of the insertion hole has a back side tapered surface that abuts on the tip side of the ferrule. Is provided,
It is configured to prevent the ferrule from entering before the front surface of the optical element.

By constructing the socket of the optical connector as described above, the plug of the optical connector according to the present invention exhibits the characteristics when engaged with the socket of the optical connector as described above. .

An optical connector plug according to the present invention is a plug of an optical connector which is provided on an end side of an optical fiber cable and engages with a socket of the optical connector, and which has a housing part fixed on the end side. An outer ferrule projecting from the inside of the housing and detachably engaged with the front side portion of the insertion hole of the socket, and an outer ferrule disposed inside the outer ferrule and holding the end of the optical fiber cable from the housing. And an elastic structure that biases the outer ferrule toward the tip side thereof, and the inner ferrule that removably engages with the inner portion of the insertion hole of the socket and that allows the outer ferrule to slide. The inner ferrule is formed such that the tip surface of the inner ferrule and the end surface of the optical fiber cable are substantially at the same position. And the dimension along the optical fiber cable of the inner ferrule is formed to be longer than the dimension along the optical fiber cable of the outer ferrule, the outer ferrule is not in a predetermined engagement with the socket, and the outer ferrule has its proximal end side. In the state in which the outer surface of the optical fiber cable is not subjected to a predetermined external pressure or more, the end surface of the optical fiber cable is stored inside the outer ferrule with respect to the tip surface of the outer ferrule because the outer ferrule is biased by the elastic body portion. In the state where the outer ferrule is in a predetermined engagement state with the socket or the outer ferrule receives an external pressure of a predetermined amount or more in the proximal direction, the end surface of the optical fiber cable is Can be protruded by a predetermined dimension from the tip of the outer ferrule Rutoshite may be.

In the case of the plug of the optical connector according to the present invention, the end side portion of the optical fiber cable reinforces the inner ferrule (the end side portion of the optical fiber cable is reinforced even if it is not formed of a sturdy material. It need only be made of a material of a certain degree.)
It has an outer ferrule (generally formed of a sturdy material) that slides on the outer peripheral side surface of this inner ferrule.

A state in which the optical connector is not used (specifically, a state in which the outer ferrule of the plug is not brought into a predetermined engagement state with the socket) and a state in which the outer ferrule is not subjected to a predetermined external pressure in the proximal direction. Since the outer ferrule is biased by the elastic body, the end surface of the optical fiber cable is stored inside the outer ferrule with respect to the tip surface of the outer ferrule.

Therefore, for example, when the optical fiber cable with a plug is transported, unless the outer ferrule receives an external pressure in excess of the force biased by the elastic body portion in the proximal direction of the outer ferrule, the end surface of the optical fiber cable is not affected. Since it is not exposed, the end face can be in a state where it is difficult to contact an external object. Therefore, in the case of the plug of the optical connector according to the present invention, if the force urged by the elastic body portion is appropriately set in relation to the external pressure, it is basically possible to carry out the above-mentioned operation even without a protective cap during transportation. There is no risk of scratching the end face.

On the other hand, when the outer ferrule is in a predetermined engagement state with the socket, that is, when the plug is engaged with the insertion hole portion of the socket, the end face of the optical fiber cable is more than the tip face of the outer ferrule. Can also be projected (exposed) by a predetermined size. Therefore, in the predetermined engagement state, the end surface of the optical fiber cable,
While being held by the inner ferrule, it can be slid and guided in the outer ferrule, and in a more stable state, it can be arranged in front of the optical element on the socket side by a minute predetermined dimension.

At this time, the end face of the optical fiber cable (and the end face of the inner ferrule located around this end face) is pushed out toward the front face side of the optical element on the socket side rather than the end face of the outer ferrule. The outer ferrule (which is usually made of a sturdy material) located on the rear side eliminates the risk of scratching the front side of the optical element on the socket side. Further, since the inner ferrule is also stopped (prevented) from being moved by the inner side portion of the insertion hole, there is no possibility of damaging the front side of the optical element. Even if the inner ferrule is pressed into contact with the front side of the optical element, make the inner ferrule material as hard as the material of the optical fiber cable (for example, plastic). In this case, the inner ferrule can prevent the front side of the optical element from being easily damaged.

When the user wants to clean the end face of the optical fiber cable, the end face is exposed if the outer ferrule is subjected to a predetermined external pressure in the proximal direction. It is possible to clean it.

The socket of the optical connector to be engaged with the plug of the optical connector according to the present invention has, for example, an insertion hole portion into which tip ends of the inner ferrule and the outer ferrule of the plug of the optical connector are inserted. An optical element fixed to the element fixing chamber provided on the back side of the insertion hole so as to communicate with the insertion hole is provided, and the tip side of the inner ferrule is provided on the back side of the insertion hole. A back taper surface is provided that abuts, and a front taper surface that abuts the tip side of the outer ferrule is provided on the front side portion thereof, and the front side of the optical element is located within a predetermined minute distance before the front surface. Insertion of the ferrule is blocked by the back tapered surface,
It suffices if the insertion of the outer ferrule is blocked by the front taper surface.

By constructing the socket of the optical connector as described above, the plug of the optical connector according to the present invention exhibits the characteristics when engaged with the socket of the optical connector as described above. There is.

The optical connector according to the present invention comprising the plug and socket of the optical connector according to the present invention as described above,
It is preferable that a retaining mechanism for preventing mutual disengagement be provided. With this retaining mechanism, it is possible to further prevent the above-mentioned scratches from occurring, and it is possible to further improve the signal transmission between the plug and the socket in the optical connector.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical connector according to a first embodiment of the present invention will be described below with reference to FIG. 1 is a schematic side sectional view of an optical connector according to a first embodiment of the present invention. FIG. 1 (A) is a diagram showing a state in which a plug of an optical connector starts to engage with a socket. (B) is a diagram showing a state where the plug of the optical connector is completely engaged with the socket.

The optical connector according to the first embodiment of the present invention is an optical connector comprising a plug 200 provided on the end side of the optical fiber cable 100 and a socket 800 engaging with the plug 200. The plug 2
00 is a substantially box-shaped housing part 210 fixed to the end side, and is slidably projected from the inside of the housing part 210 along the optical fiber cable 100, and is attached to and detached from the insertion hole part 810 of the socket 800. The ferrule 220 has a substantially cylindrical ferrule 220 that engages as much as possible, and an elastic body portion 280 that urges the ferrule 220 toward the tip side thereof.

The optical fiber cable 100 has a shaft core portion 110 composed of a plastic core and a clad, and a covering portion 120 for covering the shaft core portion 110. On the end portion side of the optical fiber cable 100, a sliding contact portion 110b of the shaft core portion 110 is provided as a portion that allows the ferrule 220 to be slidably contacted around the end portion side of the shaft core portion 110. In order to form this sliding contact portion 110b, the covering portion 120 has a predetermined length dimension and the optical fiber cable 1
00, the shaft core portion 110 is exposed.

The predetermined length dimension of the shaft core portion 110 exposed as the sliding contact portion 110b is slightly longer than the dimension of the ferrule 220 along the optical fiber cable 100. Specifically, when the plug 200 and the socket 800 are brought into a predetermined engagement state, the tip end surface 110a of the shaft core portion 110 is arranged at the back side of an insertion hole portion 810 of the socket 800, which will be described later. It is set to be a predetermined minute distance before the front surface 850a of the 850. The front end surface 120a of the covering portion 120 in this state can come into contact with the center-side base end surface 220f of the ferrule 220 described later.

The shaft core portion 110 has a tip surface 110a.
On the side, the hole tapered surface 220j of the ferrule 220 described later is provided.
Has an expanded shape portion 110a ₁ which is formed to be expanded in the circumferential direction so as to be capable of abutting against. This expanded shape portion 110a ₁
Is a tip surface 1 that is an end surface of the shaft core 110, as will be described later.
10a is formed when finishing a mirror-like flat surface in the assembly stage.

The size of the expanded shape portion 110a _{1 in} the circumferential direction is smaller than the hole portion 220h of the ferrule 220 described later, and the ferrule 220 is moved from the sliding contact portion 110b of the shaft core portion 110 at the assembly stage described later. The size is such that it can be prevented from falling off.

Furthermore, it is preferable that the size of the front end surface 110a in the circumferential direction is not too large. This is because, as the size of the front end surface 110a in the circumferential direction increases, the dimension of the expanded shape portion 110a _{1 in} the thickness direction also increases, and in such a situation, the optical element 850 and the optical fiber cable 100 are separated from each other. Considering the light transmission efficiency, the optical element 850 [in this case, it is a light emitting element. ], The optical transmission efficiency from the optical fiber cable 100 to the optical fiber cable 100 is slightly increased, while the optical fiber cable 10
The light transmission efficiency on the other end side of 0, that is, from the optical fiber cable 100 to the optical element 850 [in this case, a light receiving element. This is because the decrease in the light transmission efficiency to [] exceeds the above increase.

However, as will be described later, when the optical element 850 has a lens, if the size of the front end surface 110a in the circumferential direction is large to some extent, it is difficult to make contact with the lens 850b of the optical element 850. It is also possible to make it function. Therefore, the size of the distal end surface 110a in the circumferential direction is determined by the relative comparison of the effects described above.

The ferrule 220 is made of a metal or a sturdy resin (for example, a glass fiber having an increased strength), and has a substantially cylindrical ferrule body 220A and a base end side of the ferrule body 220A. It has a brim portion 220B extending in a mold brim shape. The ferrule 220
A through hole 220d is provided in the center of the through hole 220d to which the sliding contact portion 110b of the shaft core portion 110 can slide. A cylindrical hole portion 220h larger than the through hole 220d is formed at the end of the through hole 220d and at the end surface 220a side portion of the ferrule 220.
Is opened. At the bottom of the hole 220h, a hole tapered surface 220j is formed at the peripheral edge of the through hole 220d.

Ferrule 220 (Ferrule body 22
0A) has a tip side tapered surface 220c that abuts a back side tapered surface 810b of an insertion hole 810 of a socket 800 described later. Ferrule body 2
20A has an outer peripheral surface 220b on the front end side of the socket 8
No. 00 insertion hole portion 810 is slidably contactable with the inner surface thereof. The central axis side base end surface 220f of the ferrule 220 (collar portion 220B) has the optical fiber cable 10 on the center side.
The front end surface 120a of the covering portion 120 of 0 can contact, and one end side of the elastic body portion 280 is fixed to the peripheral side of the central axis side base end surface 220f.

The housing portion 210, which is a substantially box-shaped body, is the front surface of the housing portion 210, which is the contact surface 21 with the socket 800.
0a includes the ferrule body 220 of the ferrule 220.
A through hole 210b through which A can be projected is opened.
The size of the through hole 210b is the same as that of the ferrule body 220.
A is set to be in sliding contact with the inner peripheral surface of the through hole 210b.

Inside the housing portion 210, a wall portion 210c projecting inward for fixing and holding the optical fiber cable 100 is extended. This wall 210
In c, a through hole 210d for fixing and holding the optical fiber cable 100 is provided.
It is opened to a size that allows 20 parts to be pressed against each other.

On the contact surface 210a side, the wall portion 210c
A room 210e, which is a space inside the housing 210 formed by partitioning by, is formed so that the flange 220B of the ferrule 220 is slidably held.

The elastic portion 280 is, for example, a compression spring. That is, the free length of the elastic body portion 280 is the room portion 210e.
Is the same as the optical fiber cable 100
Or it is longer.

The socket 800 is a substantially box-shaped body, and is provided on the side that engages with the plug 200, and has an insertion hole portion 810 for detachably holding the distal end side of the ferrule main body portion 220A of the ferrule 220, It has an optical element 850 fixed to an element fixing chamber 820 provided on the inner side of the insertion hole 810 so as to communicate with the insertion hole 810.

The insertion hole 810 is formed in the ferrule body 22.
It is formed substantially along the shape of the front end side of 0A. A rear taper surface 810b for contacting the front taper surface 220c of the ferrule body 220A is provided on the rear side of the insertion hole 810. Therefore, the front end surface 220a of the ferrule body 220A (ferrule 220)
Is the element fixing chamber portion 82 communicating with the insertion hole portion 810.
It can be inserted up to an opening portion which is a boundary between 0 and the insertion hole portion 810.

A front taper surface 810a for facilitating the insertion of the ferrule body 220A is provided around the front side of the insertion hole 810. The end surface of the socket 800, which is the end surface on the side that engages with the plug 200, is the tip surface 800a of the socket 800, and is capable of contacting the contact surface 210a of the housing portion 210 of the plug 200.

The optical element 850 is a light emitting element or a light receiving element. A lens 850 is provided on the front side of the optical element 850.
b is provided. A bank-like thick portion 850c is provided on the peripheral side of the lens 850b so that the lens 850b is not easily scratched. The front end surface of the thick portion 850c is the front surface 850a of the optical element 850.

The front surface 850a is formed at a position closer to the front surface than the position of the front end portion of the lens 850b so that the front end portion of the lens 850b does not project, and the bank-like thick portion 850c is formed. It is formed to have an inclined surface that is an uphill when viewed from the lens 850b side. On the other hand, the expanded shape part 1 of the shaft core part 110 is expanded and formed so as not to easily contact the lens 850b of the optical element 850.
The size of the tip surface 110a of 10a ₁ is formed to be approximately the same as the opening size of the hole (the lens 850b is provided in the hole) formed by being surrounded by the bank-shaped thick portion 850c. Has been done.

Therefore, the tip surface 110a of the shaft core 110 is formed.
However, even if the optical element 850 is moved closer to the optical element 850 than usual due to some reason, the tip end surface 110a of the shaft core 110 is
Contacts the front surface 850a of the thick portion 850c or the upper side of the sloped slope of the bank-shaped thick portion 850c, so that it does not reach the tip of the lens 850b. it can.

However, the tip end surface 110 is not always the same as described above.
The size of a may not be formed to the same size as the opening size. As described above, the size of the tip surface 110a is set in consideration of other effects, and
This is because in the case of a plastic optical fiber, even if the tip end surface 110a of the shaft core portion 110 and the tip end side of the lens 850b come into contact with each other, the hardness difference between them is small and scarcely scratched.

Next, a method of assembling the plug 200 of the optical connector according to the first embodiment, a state in which the plug 200 is inserted into the socket 800, and the like will be described with reference to FIG. The method of assembling the plug 200 on one end of the optical fiber cable 100 will be described below as a representative. However, the optical fiber cable 10
In general, the plugs 0 are provided with plugs 200 on both end sides thereof, but the method of assembling the plugs 200 on the other end sides is the same as that described below, and therefore the description thereof is omitted.

Although not described above, the housing part 210 is composed of, for example, two parts, a right half part and a left half part, which can be fixed to each other. The optical fiber cable 100 or the like is set between the right half portion and the left half portion.

First, a predetermined sliding contact portion 110b is formed on the end portion side of the optical fiber cable 100. However, at this time, since the cut surface of the end portion of the optical fiber cable 100 has irregularities during processing, it is subjected to mirror surface processing (the expanded shape portion 110a ₁ is formed during this mirror surface processing), which will be described later. The exposed length dimension of the shaft core portion 110 is made slightly longer than the predetermined length dimension of the sliding contact portion 110b. Therefore, at this time, since the expanded shape portion 110a ₁ has not yet been formed, the tip end surface 110a also has the axial core portion 110a.
Is the thickness of the normal part.

The optical fiber cable 10 in which the sliding contact portion 110b of the shaft core portion 110 is provided on the elastic body portion 280.
Insert 0. Further, the ferrule 220 is inserted into the sliding contact portion 110b of the optical fiber cable 100.

At this stage, the expanded shape portion 110a ₁
Are formed using a dedicated jig. This dedicated jig is capable of holding the ferrule 220 and the optical fiber cable 100 in the same state as that of FIG. 1 (A). It should be noted that the state of FIG. 1 (A) refers to a ferrule 220 with respect to a predetermined optical fiber cable 100 fixed at a predetermined position in the housing portion 210.
Is inserted into the sliding contact portion 110b of the shaft core portion 110 of the optical fiber cable 100, and is most urged by the elastic body portion 280 in the distal end side direction of the ferrule 220, and the distal end side surface of the flange portion 220B is the chamber portion 210e. It is in a state of being in contact with the end portion.

The optical fiber cable 100 on which the above-mentioned expanded shape portion 110a ₁ is not yet formed is set in a dedicated jig capable of producing the same state as this with respect to the ferrule 220 and the optical fiber cable 100.

When set in this dedicated jig, the shaft core 110 is slightly exposed on the hole 220h side of the ferrule 220. With respect to the exposed shaft core 110, a hole 220h is formed.
A metal body whose tip surface is smaller than that and which has a mirror surface on the surface is pressed while being heated. As a result, the expanded shape portion 110a ₁ is formed and the expanded shape portion 11a ₁ is formed.
The distal end surface 110a of 0a ₁ is also mirror-like flat finish.

Thereafter, one end of the elastic body portion 280 is fixed to the base end of the ferrule 220. In this way, the elastic body portion 280 is normally fixed. Because, if not fixed, the elastic body portion 2 is provided between the surface on the proximal end side of the ferrule 220 and the distal end surface 120a of the covering portion 120.
There is a possibility that a part of 80 will be fitted, and if such fitting occurs, the front end face 110a will be retracted from a predetermined position, and the front surface 85 of the optical element 850 will be retracted.
This is because it becomes impossible to dispose the front end face 110a in front of a predetermined minute distance of 0a. Therefore, if there is no such a possibility,
It is not necessary to fix one end side of the elastic body portion 280.

As mentioned above, the fiber optic cable 10
The ferrule 220 is inserted into the sliding contact portion 110b of 0 and the expanded shape portion 110a ₁ is formed so that the elastic body portion 280 is compressed and the state shown in FIG. , The housing 210 is set in the room 210e on one side of the right half part or the left half part. At this time, a predetermined position of the optical fiber cable 100 is set at the through hole 2
Press-fit and fix to 10d. The portion of the optical fiber cable 100 press-fitted and fixed in the through hole 210d is also fixed with an adhesive as necessary.

After that, when the other side is fixed to the one side of the housing part 210, the assembly of the plug 200 is completed.

The socket 800 has an insertion hole portion 81.
The shape of 0 is the ferrule 2 of the plug 200 as described above.
Since the structure is general except that it is adapted to the tip end side of 20, the description of its assembly is omitted.

The plug 200 assembled in this way
As shown in FIG. 1 (A) and FIG. 1 (B), the contact pressure between the outer peripheral surface 220 b of the ferrule 220 and the inner surface of the insertion hole 810 is increased as the socket is inserted into the insertion hole 810 of the socket 800. Then, the ferrule 220 receives a force (kinetic frictional force) that pushes it back toward the base end side. The ferrule 220 receives the urging force of the elastic body portion 280 and the central axis side base end face 220f of the ferrule 220 against the pushing back force.
Is abutted with the tip end surface 120a of the covering portion 120 of the optical fiber cable 100 and receives a reaction.

Therefore, while countering the pushing back force,
The ferrule 220 enters the inner side of the insertion hole 810, but when the tip side tapered surface 220c of the ferrule 220 and the inner side tapered surface 810b of the insertion hole 810 come into contact with each other, the progress thereof is stopped (blocked). ). Elastic body part 2 at this time
An urging force of 80 (hereinafter referred to as an "engagement urging force"),
Due to the static frictional force between the outer peripheral surface 220b of the ferrule 220 and the inner surface of the insertion hole 810 (hereinafter, referred to as "static frictional force during engagement"), the tip side of the ferrule 220 and the insertion hole 810 are difficult to separate. As described above, they are strongly engaged with each other.

Although this state is shown in FIG. 1B, the ferrule 220 is in a state where the central axis side base end face 220f is in contact with the front end face 120a of the covering portion 120 of the optical fiber cable 100. In this state, the expanded shape portion 110a ₁ is advanced from the front end surface 220a of the ferrule 220, and the front end surface 110a is arranged in front of the front surface 850a of the optical element 850 by a predetermined small distance. Therefore, with respect to the front surface 850a of the optical element 850, the ferrule
Since the front end surface 220a of 0 is arranged, the ferrule 22
There is no possibility that 0 will damage the front surface 850a side of the optical element 850.

Therefore, since the predetermined minute distance can be set to be extremely small and there is no possibility of being damaged as described above, the optical fiber cable 100 includes the shaft core portion 110 and the optical element 850. The light transmission efficiency (signal transmission efficiency) between the two can be improved more than before.

The engaging biasing force with respect to the ferrule 220 acts as a force for pulling them away from each other in the relationship between the plug 200 and the socket 800. Therefore, the biasing force at the time of engagement is the weight of the device in which the socket 800 is provided, the plug 200, and the optical fiber cable 10.
Plug 200 and socket 8 generated by zero weight etc.
If the frictional force with the plug 00 is exceeded, the tip side of the plug 200 remains fitted in the insertion hole 810,
A gap is created between the plug 200 and the socket 800. In such a case, there is an inconvenience that the front end surface 110a is retracted from a position which is a predetermined minute distance before the front surface 850a of the optical element 850. Therefore, in order to eliminate this inconvenience, it is desirable to provide the plug 200 and the socket 800 with a retaining mechanism which will be described later.

On the other hand, when the plug 200 is not inserted into the socket 800 as described above, the ferrule 220 receives the biasing force of the elastic body portion 280, so that the front end surface 110a of the optical fiber cable 100 becomes the front end surface of the ferrule 220. It is in a state of being stored inside the 220a.

Therefore, when the optical fiber cable 100 with the plug 200 attached is conveyed, unless the external pressure exceeding the urging force of the elastic body portion 280 is received in the proximal direction of the ferrule 220, the front end surface of the optical fiber cable 100. 110 a is protected by the ferrule 220.

When the urging force of the elastic body portion 280 is set to be larger than the external pressure applied in the proximal direction of the ferrule 220 at the time of transportation, the protection of the distal end surface 110a of the optical fiber cable 100 is properly performed. Become. by the way,
As described above, the engaging biasing force of the elastic body portion 280 also causes the inconvenience, and therefore it is difficult to increase the force as it is. Therefore, when the urging force of the elastic body portion 280 cannot be properly compared with the external pressure during the conveyance, a retaining mechanism, which will be described later, is provided in the plug 200 and the socket 800, so that the elastic body portion 280 is provided. The urging force of can be made sufficiently larger than the above case.

The user can use the optical fiber cable 100
When it is desired to clean the front end surface 110a of the above, if the ferrule 220 is subjected to an external pressure of a predetermined amount or more in the base end side direction, the front end surface 110a can be exposed, so that the ferrule 220 can be cleaned.

In the plug 200 of the optical connector according to the first embodiment of the present invention, the elastic body portion 280 may be another elastic body such as elastic rubber instead of the compression spring.

In the optical connector according to the first embodiment of the present invention, the elastic body portion 280 is the compression spring. However, even if the same spring is used, the optical connector according to the next second embodiment of the present invention will be described. A contact spring may also be used, as will be described in. An optical connector according to the second embodiment of the present invention will be briefly described below with reference to FIG. FIG. 2 is a schematic side sectional view of an optical connector according to a second embodiment of the present invention. FIG. 2A is a diagram showing a state in which a plug of the optical connector has started to engage with a socket. (B) is a diagram showing a state where the plug of the optical connector is completely engaged with the socket.

The optical connector according to the second embodiment of the present invention comprises a plug 200 'in which the elastic body portion 280 of the plug 200 is replaced with an elastic body portion 281 (contact spring), and a socket 800.

In the plug 200 ', the elastic body portion 281
Is provided on the distal end side of the flange portion 220B of the ferrule 220, not on the proximal end side, in the chamber 210e.
The one end side of the elastic body portion 281 has the collar portion 2 of the ferrule 220.
20B is fixed to the front end side of the ferrule 2 while the other end of the elastic body portion 281 is the inner surface of the chamber 210e.
It is fixed to the surface of 20 at the tip side.

Therefore, the ferrule 220 receives the urging force of the reaction in the extending direction of the elastic body portion 281. Other than this, at the time of assembly, the elastic body portion 28
Although the insertion position and the fixed position of 1 are changed as described above, basically the plug 2 according to the first embodiment of the present invention
Since it is the same as 00, the description of the operation and the like will be omitted.

Although the optical connector per one optical fiber cable 100 has been described above, an optical connector for the two optical fiber cables 100, 100 according to the third embodiment of the present invention will be described next. The optical connector will be described with reference to FIG. Figure 3
[Fig. 6] is a schematic plan view in section showing an optical connector according to a third embodiment of the present invention.

The optical connector according to the third embodiment of the present invention comprises a plug 200T provided at the end portions of the two optical fiber cables 100, 100 in the same direction, and a socket 800T engaging with the plug 200T. Consists of.

The side surface of the plug 200T is similar to that of the plug 200 shown in FIG. The plug 200T can be roughly regarded as a structure in which two plugs 200 are arranged side by side in the lateral direction and are seamlessly integrated. On the other hand, the socket 800T has a structure in which two sockets 800 are arranged side by side in the lateral direction and integrated seamlessly. Therefore, only a part that is not a structure in which two optical connectors according to the first embodiment of the present invention are arranged side by side and seamlessly integrated will be described below.

Housing portion 210T of the plug 200T
In contrast to a structure in which two housing portions 210 are arranged side by side and seamlessly integrated, a ferrule main body portion 220A of a ferrule 220T of a plug 200T described later is connected to the housing portion 2
Through hole 210b 'for projecting from the inside of 10T (through hole 210b in the optical connector according to the first embodiment.
The size of the part corresponding to) was changed slightly in the horizontal direction. Therefore, the two ferrules 220T and 220T
Can move to the left and right to some extent, so the socket 800
The two ferrules 220T can be inserted into the two T insertion holes 810 while flexibly changing the directions on the horizontal plane.

The reason for making such a change is that the hole diameters of the insertion hole portions 810, 810 of the socket 800T are slightly increased in consideration of the influence of the dimensional tolerance of the pitch between the ferrules 220T, 220T on the plug 200T side. It was necessary to make the outer diameter of the ferrule 220T or to make the outer diameter of the ferrule 220T slightly smaller, but it is not necessary to do such a thing. Therefore, the hole diameters of the insertion hole portions 810, 810 of the socket 800T and the outer diameter of the ferrule 220T can be accurately formed (as in the case of the single optical fiber cable 100), and the accuracy of axis alignment is improved. Therefore, the light transmission efficiency (signal transmission efficiency) is improved.

Further, the ferrule 220T is provided with an extending portion 220D 'rearward from the end portion on the base end side of the collar portion 220B of the ferrule 220T. This extension 220D 'is
It is a substantially rectangular body and is provided at both ends of the collar portion 220B in the horizontal plane, and has a function of smoothly sliding the ferrule 220T in the front-rear direction (hence, the first aspect).
The extended portion 220D 'may be provided in the optical connector according to the second embodiment as well. ). Extension 220
The length dimension of D ′ in the horizontal direction is smaller than the length dimension at which the elastic body portion 280 can be compressed most. That is,
The tip end side of the elastic body portion 280 is the tip end surface 12 of the covering portion 120.
Since the extension 220D 'is compressed only to 0a, the horizontal length of the extension 220D' is smaller than the length of the elastic body 280 in this state.

The extending portion 220D 'which is a substantially rectangular body.
Has a relatively thin thickness and is made flexible, so that the effect of slightly changing the size of the through hole 210b 'only in the horizontal direction is hardly reduced.

By the way, in general, one of the optical elements 850 and 850 is a light emitting element and the other is a light receiving element.

Next, the optical connector according to the fourth embodiment of the present invention will be described with reference to the optical connector according to the third embodiment of the present invention in which a retaining mechanism is provided. This will be described with reference to FIG. 4A and 4B are views showing an optical connector according to a fourth embodiment of the present invention. FIG. 4A is a schematic side view and FIG. 4B is a schematic sectional view in plan view.

The optical connector according to the fourth embodiment of the present invention has the following modifications made to the optical connector according to the third embodiment of the present invention. With respect to the plug 200T, hooking parts 290 'forming one of the retaining prevention mechanisms are provided on both sides of the front end of the housing 210T so as to form a plug 200T'. For the socket 800T,
A recess 860 '(the other side of the retaining mechanism) into which the claw 292a' is fitted is formed at a position where the claw 292a 'of the hooking tool 290' of the plug 200T 'described later is engaged, and the socket 800T' is formed. And

The hooking part 290 'has a substantially L-shaped plan view and a substantially U-shaped support part 291' in a side view, and a rear side of the U-shaped part of the support part 291 'in a side view. It includes a tongue-shaped engagement portion 292 'extending from the center toward the tip of the plug 200T'. The locking portion 292 'is substantially V-shaped in a plan view, and has a claw portion 292a' on the inner side on the tip side and a fulcrum convex portion 292b 'on the inner side near the center.

The claw portion 292a 'is a portion which fits in the recess 860' and controls the engagement between the plug 200T 'and the socket 800T'. By forming the claw portion 292a ′, the inner end side of the claw portion 292a ′ is provided with the socket 80T when the plug 200T ′ is not inserted into the socket 800T ′.
It is located inside the side of 0T '. Thereby, when the plug 200T 'is inserted into the socket 800T', the two claw portions 292a 'are biased inward. The fulcrum convex portion 292b 'is formed so as to be able to contact the side surface portion of the socket 800T'.

Therefore, when the socket 800T 'and the plug 200T' are engaged with each other, as shown in FIG.
The claw portion 292a 'fits into the 0'while being biased, and the socket 800T' and the plug 200T 'are locked to each other.

It is the support portion 291 'that releases the mutual engagement between the socket 800T' and the plug 200T ', and the base end side portion 291a' of the tongue-like engagement portion 292 'is released at both positions. This is done by pressing inward. By this depression, the claw portion 292a 'comes out of the concave portion 860' with the fulcrum convex portion 292b 'abutting on the side surface of the socket 800T' as a fulcrum.

As described above, in the optical connector according to the fourth embodiment of the present invention, since the retaining mechanism is provided, the plug 200T 'in the optical connector is provided.
The optical transmission efficiency (signal transmission efficiency) between the socket and the socket 800T 'can be secured more appropriately than those of the optical connectors according to the first to third embodiments of the present invention, and the above-mentioned scratches are further provided. It can be difficult.

Further, the socket 800T 'and the plug 200
Since T'is securely locked by the retaining mechanism, the urging force of the elastic body portion 280 is applied to the elastic body portion 28 in the optical connector according to the first to third embodiments of the present invention.
It can be set to be larger than the biasing force of 0 (or 281). Thus, when carrying the optical fiber cables 100 with the plug 200T ',
The external pressure exceeding the urging force of the elastic body portion 280 is reduced as compared with the optical connectors according to the first to third embodiments of the present invention. That is, the front end surface 110a of the optical fiber cable 100 is more surely protected by the ferrule 220T. Further, by providing this retaining mechanism, it is possible to eliminate the above-mentioned inconvenience.

In the optical connector according to the fourth embodiment of the present invention, the recess 8 is provided on the plug 200T 'side.
It is also possible to provide a component corresponding to 60 'and a component corresponding to the hooking part 290' on the socket 800T 'side.

Next, another embodiment of an optical connector provided with a retaining mechanism will be described as an optical connector according to a fifth embodiment of the present invention with reference to FIG. Figure 5
FIG. 9 is a schematic cross-sectional view showing an optical connector according to a fifth embodiment of the present invention, in which a housing part of a plug and a housing part side of a socket are not shown.

In the optical connector according to the fifth embodiment of the present invention, the tip side portion of the ferrule 220 of the plug 200 of the optical connector according to the first embodiment of the present invention is usually used for electrical connection. And a plug 200J having a ferrule 220J having an outer shape substantially similar to the ferrule equivalent part of the plug, and a ferrule 220 of this plug 200J.
And a socket 800J with which J engages.

A portion of the plug 200J on the side of the housing portion (not shown) is the same as the housing portion 210 of the plug 200 of the optical connector according to the first embodiment of the present invention and the inside thereof. The structure of the ferrule 220J on the base end side is the same as the structure of the ferrule 220 on the base end side. The structure of the ferrule 220J on the front end side is substantially cylindrical, and has a tapered surface 221J on the outer circumference of the front end. On the outer circumference from the base end side of the taper surface 221J to the base end side of the ferrule 220J, the taper surface 22
A reverse taper surface 222J is formed in a direction opposite to 1J.

Like the ferrule 220, a hole 220h is formed at the tip of the ferrule 220J, and this hole 220h is formed.
And a hole tapered surface 220j formed at the bottom of the. The structure of the optical fiber cable 100 is basically the same as that of the optical connector according to the first embodiment of the present invention.

The socket 800J is the ferrule 220J.
Has an insertion hole portion 810J into which the tip end side of is inserted.
The innermost portion of the insertion hole portion 810J is a cylindrical first space portion 811J. This first space portion 811J
Communicates with an element fixing chamber 820J for fixing the optical element 850 in the socket 800J.

In the first space 811J, the tip end surface 110a of the optical fiber cable 100 can be moved forward to the front side of the optical element 850. When the tip side of the ferrule 220J is on the front side of the first space 811J and is engaged with the socket 800J,
A cylindrical second space portion 812J is provided at a position where the reverse tapered surface 222J is arranged. Between the second space portion 812J and the first space portion 811J, the back side taper surface 813 capable of contacting the taper surface 221J.
J (one side of the retaining prevention mechanism) is formed.

A retainer 830J, which is the other side of the retaining mechanism, is fitted into the second space 812J. The holder 830J is a metal leaf spring, and has a frame portion 831J having a round hole at the center thereof through which the front end side of the ferrule 220J is inserted, and a pair extending from the edge of the frame portion 831J to the rear side. Contact portions 832J and 832J. The pair of contact portions 832J and 832J are relatively inclined inward.

The tip side of the ferrule 220J is press-fitted between the pair of contact portions 832J and 832J while pushing the contact portion 832J away from the contact portion 832J, and the back side tapered surface 81 is inserted into the contact portion 832J.
When 3J abuts, ferrule 220J (that is, plug 200J) and socket 800J mutually,
It is held with a larger force than when the retaining mechanism is not provided.

Therefore, since this retaining mechanism is provided, it has the same effect as the retaining mechanism provided in the optical connector according to the above-described fourth embodiment.

In the optical connector according to the fifth embodiment of the present invention, a metal leaf spring is not provided like the holder 830J, but a resinous member protruding into the second space 812J is used. The leaf spring may be formed integrally with the socket 800J.

Next, instead of using one ferrule of the optical connector according to the first embodiment of the present invention, two ferrules, an outer ferrule and an inner ferrule provided inside the ferrule, are used. A partially modified version of the optical connector according to the sixth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a schematic sectional side view of an optical connector according to a sixth embodiment of the present invention.
FIG. 6A is a diagram showing a state where the plug of the optical connector has started to engage with the socket, and FIG. 6B is a diagram showing a state of the plug of the optical connector being completely engaged with the socket.

The optical connector according to the sixth embodiment of the present invention comprises a plug 200W provided on the end side of the optical fiber cable 100 and a socket 800W engaging with the plug 200W.

The plug 200W is provided with a housing part 210 fixed to the end side and an outer side projecting from the inside of the housing part 210 and detachably engaged with the front part of the insertion hole part 870 'of the socket 800W. Ferrule 275 '
And is disposed inside the outer ferrule 275 'and protrudes from the housing portion 210 so as to firmly hold the end portion side of the optical fiber cable 100, and is detachably engaged with the inner side portion of the insertion hole portion 870' of the socket 800W. It has an inner ferrule 270 'that fits together and allows the outer ferrule 275' to slide, and an elastic body portion 280 that urges the outer ferrule 275 'toward the tip side thereof.

The inner ferrule 270 'includes a substantially cylindrical ferrule body 270A' and the ferrule body 2
70A 'has a flange portion 270B' extending around the base end side. The inner ferrule 270 ′ includes the end portion of the optical fiber cable 100, the covering portion 120, and the length dimension of the inner ferrule 270 ′ (the optical fiber cable 100).
It is provided around the portion where the shaft center portion 110 is exposed by removing the length of the shaft center portion 110. That is, the front end surface 270a 'of the inner ferrule 270' and the front end surface 110a of the optical fiber cable are formed at the same position. The size of the inner ferrule 270 'along the optical fiber cable 100 is the outer ferrule 275'.
Is formed to be longer than the dimension along the optical fiber cable 100.

A tapered surface 270c 'is provided around the distal end side of the inner ferrule 270'.

The outer ferrule 275 'includes a substantially cylindrical ferrule body 275A' and the ferrule body 2
And a flange portion 275B 'extending around the base end side of 75A'. The outer ferrule 275 'is slidable on the outer peripheral surface of the ferrule body 270A' of the inner ferrule 270 '. Also, the outer ferrule 275 '
Of the inner ferrule 270 'can be advanced further than the front end surface 270a' of the inner ferrule 270 '.

A taper surface 275c 'is provided around the tip side of the outer ferrule 275'. Elastic body part 2
The one end side of 80 is a collar portion 275 of the outer ferrule 275 '.
B ', which is the base end of the inner ferrule 2
It is fixed to a peripheral side portion of the collar portion 270B 'of the 70', which is not in contact with the tip portion of the collar portion 270B '. Other than this, it is basically the same as the plug 200.

The socket 800W has an inner ferrule 27.
Back side taper surface 87 with which 0'taper surface 270c 'abuts
1'and the tapered surface 275c 'of the outer ferrule 275'.
Has an insertion hole portion 870 'having a front side tapered surface 872' with which the abutting portion abuts. The insertion hole portion 870 ′ communicates with the element fixing chamber portion 820. The rest is the same as the socket 800.

Such a socket 800W and plug 20
The assembling method with 0 W can be easily performed according to the method in the first embodiment of the present invention, and therefore the description thereof will be omitted.

After assembly, the outer ferrule 2
As long as the outer ferrule 275 ′ receives the urging force of the elastic body portion 280, the outer ferrule 275 ′ receives the urging force of the elastic body portion 280, unless the outer peripheral surface of the outer ferrule 275 ′ is subjected to an external pressure (= an external pressure larger than the urging force of the elastic body portion 280). Tip surface 270a 'of inner ferrule 270'
(It should be noted that the tip end surface 110a of the optical fiber cable 100 is also at the same position.), But is in a state of being stored inside the tip end surface 275a 'of the outer ferrule 275'.

Therefore, when carrying the optical fiber cable 100 with the plug 200W attached, an external pressure equal to or greater than the biasing force of the elastic portion 280 is applied to the outer ferrule 27.
Unless it is received in the direction of the base end side of 5 ', the front end surface 110a of the optical fiber cable 100 has the outer ferrule 275'.
Protected by.

When inserting the plug 200W into the socket 800W, the contact pressure between the inner surface of the insertion hole 870 'and the outer peripheral surface of the outer ferrule 275' causes the outer ferrule 275 'to be pushed back toward its proximal end. It receives the force (kinetic frictional force). In response to this pushing-back force, the outer ferrule 275 'has the biasing force of the elastic body portion 280 and the base end portion of the collar portion 275B' of the outer ferrule 275 'is the tip portion of the collar portion 270B' of the inner ferrule 270 '. Abutting and receiving reaction. Therefore, the outer ferrule 275 'is inserted into the insertion hole portion 87 while resisting the pushing back force.
Although the taper surface 275c ′ of the outer ferrule 275 ′ abuts on the front taper surface 872 ′, the taper surface 270 of the inner ferrule 270 ′ is inserted.
When c ′ comes into contact with the back side tapered surface 871 ′, the progress thereof is stopped (blocked).

This state is the state of FIG. 6B,
The front end surface 110a of the optical fiber cable 100 is arranged in front of the front surface 850a of the optical element 850 by a predetermined minute distance. At this time, the outer ferrule 275 '
[Usually made of metal or sturdy resin (for example, glass fiber of which strength is increased)] is arranged behind the tip end surface 110a of the optical fiber cable 100,
The front surface 850a of the optical element 850 is the outer ferrule 27.
There is no danger of being scratched by 5 '.

The inner ferrule 270 'has a tapered surface 27.
0c 'comes into contact with the taper surface 871' on the back side to contact the optical element 850.
Optical element 850 because it is blocked from moving forward.
There is no possibility of contact with the front surface 850a of the. Even if the inner ferrule 270 'is pressed in with a large force and the tip surface 270a' comes into contact with the optical element 850, the tip surface 270a 'is the tip surface of the optical fiber cable 100. Since it exists around 110a,
It comes into contact with the thick portion 850c of the optical element 850,
There is no possibility of contact with the lens 850b of the optical element 850. Therefore, there is no possibility that the lens 850b will be damaged.

Furthermore, the inner ferrule 270 'is
It need not be made of metal, but can be made of resin. Therefore, there is no particular problem of damage due to the inner ferrule 270 '.

By the way, when the user wants to clean the front end surface 110a of the optical fiber cable 100, for example, if the outer ferrule 275 'is subjected to an external pressure higher than a predetermined value in the proximal direction, Since the tip end surface 110a can be exposed, it can be cleaned.

By using means for sliding the end portion side of the optical fiber cable 100 thus held by the inner ferrule 270 'inside the outer ferrule 275', the optical fiber cable 100
The alignment accuracy between the shaft core part 110 and the optical element 850 is improved, and the deviation in the optical axis direction from the optical element 850 can be suppressed.

Incidentally, also in the optical connector according to the sixth embodiment of the present invention, it is preferable to provide a retaining mechanism as in the optical connector according to the fourth embodiment. Further, it goes without saying that the optical connector according to the sixth embodiment of the present invention can also be configured as the optical connector according to the second, third and fifth embodiments.

The optical element 850 used in the optical connector according to the first to sixth embodiments of the present invention is the same as that described in the optical connector according to the first embodiment of the present invention (see FIG. 1). It is assumed that the bank-shaped thick portion 850c provided around the lens 850b is formed so as to have an inclined surface that is an uphill when viewed from the lens 850b side. In such an optical element 850, the expanded shape portion 11
Assuming that the size of the front end surface 110a of 0a ₁ is slightly smaller than the opening size of the hole formed by being surrounded by the thick portion 850c, as described above, the lens 850
It is possible not to reach the tip portion of b. FIG. 7 shows the state at this time as a precaution.

FIG. 7 shows the optical element used in the optical connector according to the first to fifth embodiments of the present invention, in which the tip end surface of the expanded shape portion of the shaft core portion of the optical fiber cable is the meat of the optical element. Inside the hole surrounded by the thick portion (inside the front surface of the thick portion) and not in contact with the lens of the optical element, but in contact with the inclined surface of the thick portion It is a schematic explanatory view showing.

As described above, by making the size of the front end surface 110a larger than the opening size around the front end of the lens 850b, the front end surface 1 of the expanded shape portion 110a ₁ is
It is possible to prevent 10a from coming into contact with the upper side of the sloped surface of the bank-shaped thick portion 850c that is an upward slope and not reaching the tip portion of the lens 850b. In this state,
Since the tip surface 110a of the optical fiber cable 100 and the tip portion of the lens 850b of the optical element 850 are extremely close to each other, the light transmission efficiency (signal transmission efficiency) is higher.

Therefore, the state in which the tip end surface 110a of the optical fiber cable 100 is inserted into the hole formed by being surrounded by the thick portion 850c is according to the first to fifth embodiments of the present invention. It may be a normal state in the optical connector. That is, for example, in the optical connector according to the first embodiment of the present invention, the optical element 8
The front face 850a (the thick portion 850c) is not located in the normal state (see FIG. 1) from the front face 850a (which is also the front face of the thick portion 850c) before a predetermined minute distance. (It is also the front surface of 850c.) Inside the optical element 850, and the front end surface 110a may be arranged in a predetermined minute distance before the front end portion of the lens 850b (see FIG. 7) in the normal state. .

However, in that case, as described above with reference to FIG. 7, even if the size of the front end surface 110a is made larger than the opening size around the front end portion of the lens 850b, it may be caused by some factor. Lens 85 than usual
It is preferable that even if the tip surface 110a tries to enter the tip portion of 0b, the tip surface 110a is prevented from entering.

In this case, more preferably, the optical element 850
It is advisable to form a step as shown in FIG. FIG. 8 shows a step portion provided on the optical element used in the optical connector according to the first to fifth embodiments of the present invention, and the tip surface of the expanded shape portion of the shaft core portion of the optical fiber cable abuts on this step portion. It is a schematic explanatory drawing which shows the state which contacted. That is, the optical element 8
The stepped portion 85 is inside the front surface 850a of the thick portion 850c of 50 and outside the tip portion of the lens 850b.
0d is formed. The size of the stepped portion 850d is such that the peripheral edge side of the front end surface 110a abuts.

In this case, the inside of the front surface 850a, slightly ahead of the position (the position in the state of FIG. 8) where the tip surface 110a abuts this step portion 850d, the tip surface 110a is the lens. It is also possible to set the position to be the predetermined minute distance before the tip portion of 850b. Further, the position where the tip end surface 110a abuts on this step portion 850d (see FIG.
(The position in the state of 1) can be a position that is the predetermined minute distance from the tip portion of the lens 850b. Further, even with the optical element 850 provided with the step portion 850d, as described in the optical connectors according to the first to fifth embodiments of the present invention, the front surface 850a of the optical element 850 is described.
It goes without saying that it may be in a normal state to dispose the front end face 110a (see FIG. 1) before a predetermined minute distance (which is also the front face of the thick portion 850c).

The contents described with reference to FIGS. 7 and 8 can be directly applied to the optical element 850 used in the optical connector according to the second to fifth embodiments of the present invention. Although not shown, the optical element 850 in the optical connector according to the sixth embodiment of the present invention may be applied. At that time, in the case of FIG. 7, the tapered surface 270c ′ (see FIG. 6) of the inner ferrule 270 ′ is brought into contact with the inclined surface in the thick portion 850c of the optical element 850, or just before that. To enter. In the case of FIG. 8, the front end surface 270a ′ of the inner ferrule 270 ′.
(See FIG. 6) is brought into contact with the stepped portion 850d of the optical element 850 or is made to enter the stepped portion 850d.

In the optical connectors according to the first to sixth embodiments of the present invention, the expanded shape portion 110a ₁ may not be provided (that is, the shaft core portion 110 may have the same thickness up to the tip). ).

In the optical connectors according to the first to sixth embodiments of the present invention, the optical element 850 may not be provided with the lens 850b. Even if the front surface side of the optical element 850 is a flat type, the same state as described above is obtained (however, except for the optical connector according to the sixth embodiment, the effect of the thick portion 850c is lost. ).

[0126]

As described above, the plug of the optical connector according to the present invention is the plug of the optical connector which is provided on the end side of the optical fiber cable and engages with the socket of the optical connector. A housing part fixed to the part side, a ferrule slidably projecting from the inside of the housing part along the optical fiber cable and detachably engaged with the insertion hole part of the socket, and the ferrule in the distal side direction. The optical fiber cable has a sliding contact portion with a ferrule having a dimension longer than the dimension of the ferrule along the optical fiber cable, and the ferrule is a socket. In a state where the ferrule is not in the predetermined engagement state and the ferrule does not receive an external pressure of a predetermined amount or more in the proximal direction,
The end face of the optical fiber cable is stored inside the ferrule with respect to the end face of the ferrule by biasing the ferrule by the elastic body portion, and the ferrule is in a predetermined engagement state with the socket. Or the end face of the optical fiber cable is capable of protruding by a predetermined dimension from the end face of the ferrule in a state in which the ferrule receives an external pressure of a predetermined amount or more in the base end side direction. Characterize.

Therefore, in the case of the plug of the optical connector according to the present invention, the plug is not used (specifically, the ferrule of the plug is not brought into a predetermined engagement state with the socket) and the ferrule of the plug is When the ferrule is biased by the elastic body portion in the state where the ferrule is not subjected to an external pressure of a predetermined amount or more in the proximal direction, the end face of the optical fiber cable is stored inside the ferrule with respect to the tip face of the ferrule.

Therefore, for example, when the optical fiber cable with a plug is conveyed, the end face of the optical fiber cable is exposed unless the ferrule receives an external pressure in excess of the force urged by the elastic body in the proximal direction of the ferrule. Therefore, it is possible to make the end face difficult to contact with an external object. Therefore, in the case of the plug of the optical connector according to the present invention, if the force urged by the elastic body portion is appropriately set in relation to the external pressure, it is basically possible to carry out the above-mentioned operation even without a protective cap during transportation. There is no risk of scratching the end face.

Therefore, the troublesome work of attaching the protective cap during transportation and removing the protective cap during use becomes unnecessary.

On the other hand, when the ferrule is in a predetermined engagement state with the socket, that is, when the plug is engaged with the insertion hole portion of the socket, the end surface of the optical fiber cable is more predetermined than the tip surface of the ferrule. It can be projected (exposed) by the dimension of. Therefore, in the predetermined engagement state, the end surface of the optical fiber cable can be arranged in front of the front surface of the optical element on the socket side by a minute predetermined dimension. At the same time, the end face of the optical fiber cable is pushed out to the front side of the optical element on the socket side from the front end face of the ferrule, so that the front side of the optical element on the socket side is positioned by the ferrule that is positioned behind the end face. There is no risk of being damaged.

The minute predetermined size can be made smaller than before because the front side of the socket side optical element is not damaged by the ferrule. In addition, considering that it will not be damaged, the light transmission efficiency (signal transmission efficiency) can be improved more than before.

Further, when the user wants to clean the end face of the optical fiber cable, for example, the end face can be exposed by creating a state in which the ferrule receives an external pressure higher than a predetermined value in the proximal direction. It can be cleaned because it can Therefore, maintenance is easy.

Further, when an optical connector is provided for two optical fiber cables, the plug may have a structure in which the ferrule can freely move to the left and right to some extent. Conventionally, considering the influence of the dimensional tolerance of the pitch between the two ferrules on the plug side,
It was necessary to make the hole diameters of the two insertion holes slightly larger or to make the outer diameter of the ferrule slightly smaller, but it is not necessary to do such a thing. Therefore, the hole diameter of the insertion hole of the socket and the outer diameter of the ferrule (as in the case of one optical fiber cable) can be made with high accuracy, and the accuracy of axis alignment is improved, so that the light transmission efficiency ( Signal transmission efficiency) can be improved.

Such an optical connector socket that engages with the plug of the optical connector according to the present invention has, for example, an insertion hole portion into which the front end side of the ferrule of the plug of the above-mentioned optical species is inserted, and this insertion hole portion. It is equipped with an optical element that is fixed to the element fixing chamber that is provided on the back side of the insertion hole so that they communicate with each other, and the back side of the insertion hole that taps against the tip side of the ferrule. It suffices that the surface is provided and the insertion of the ferrule is blocked before the front surface of the optical element.

By constructing the socket of the optical connector as described above, the characteristics of the plug of the optical connector according to the present invention when engaged with the socket of the optical connector as described above (basically, , The front side of the optical element is not likely to be damaged, etc.).

An optical connector plug according to the present invention is an optical connector plug which is provided on the end side of an optical fiber cable and engages with the socket of the optical connector, and which has a housing part fixed to the end side. An outer ferrule projecting from the inside of the housing and detachably engaged with the front side portion of the insertion hole of the socket, and an outer ferrule disposed inside the outer ferrule and holding the end of the optical fiber cable from the housing. And an elastic structure that biases the outer ferrule toward the tip side thereof, and the inner ferrule that removably engages with the inner portion of the insertion hole of the socket and that allows the outer ferrule to slide. The inner ferrule is formed such that the tip surface of the inner ferrule and the end surface of the optical fiber cable are substantially at the same position. And the dimension along the optical fiber cable of the inner ferrule is formed to be longer than the dimension along the optical fiber cable of the outer ferrule, the outer ferrule is not in a predetermined engagement with the socket, and the outer ferrule has its proximal end side. In the state in which the outer surface of the optical fiber cable is not subjected to a predetermined external pressure or more, the end surface of the optical fiber cable is stored inside the outer ferrule with respect to the tip surface of the outer ferrule because the outer ferrule is biased by the elastic body portion. In the state where the outer ferrule is in a predetermined engagement state with the socket or the outer ferrule receives an external pressure of a predetermined amount or more in the proximal direction, the end surface of the optical fiber cable is Can be protruded by a predetermined dimension from the tip of the outer ferrule Rutoshite may be.

In the case of the plug of the optical connector according to the present invention, the end side portion of the optical fiber cable reinforces the inner ferrule (the end side portion of the optical fiber cable is reinforced even if it is not formed of a sturdy material. It need only be made of a material of a certain degree.)
It has an outer ferrule (generally formed of a sturdy material) that slides on the outer peripheral side surface of this inner ferrule.

A state in which the optical connector is not used (specifically, a state in which the outer ferrule of the plug is not brought into a predetermined engagement state with the socket) and a state in which the outer ferrule is not subjected to a predetermined external pressure in the proximal direction. Since the outer ferrule is biased by the elastic body, the end surface of the optical fiber cable is stored inside the outer ferrule with respect to the tip surface of the outer ferrule.

Therefore, for example, when the optical fiber cable with a plug is conveyed, unless the outer ferrule receives an external pressure in excess of the force biased by the elastic body in the proximal direction of the outer ferrule, the end surface of the optical fiber cable is Since it is not exposed, the end face can be in a state where it is difficult to contact an external object. Therefore, in the case of the plug of the optical connector according to the present invention, if the force urged by the elastic body portion is appropriately set in relation to the external pressure, it is basically possible to carry out the above-mentioned operation even without a protective cap during transportation. There is no risk of scratching the end face.

Therefore, the troublesome work of attaching the protective cap during transportation and removing the protective cap during use becomes unnecessary.

On the other hand, when the outer ferrule is in a predetermined engagement state with the socket, that is, when the plug is engaged with the insertion hole portion of the socket, the end face of the optical fiber cable is more than the tip face of the outer ferrule. Can also be projected (exposed) by a predetermined size. Therefore, in the predetermined engagement state, the end surface of the optical fiber cable,
While being held by the inner ferrule, it can be slid and guided in the outer ferrule, and in a more stable state, it can be arranged in front of the optical element on the socket side by a minute predetermined dimension.

At this time, the end face of the optical fiber cable (and the end face of the inner ferrule located around this end face) is pushed out to the front face side of the socket side optical element rather than the end face of the outer ferrule. The outer ferrule (which is usually made of a sturdy material) located on the rear side eliminates the risk of scratching the front side of the optical element on the socket side. Further, since the inner ferrule is also stopped (prevented) from being moved by the inner side portion of the insertion hole, there is no possibility of damaging the front side of the optical element. Even if the inner ferrule is pressed into contact with the front side of the optical element, make the inner ferrule material as hard as the material of the optical fiber cable (for example, plastic). In this case, the inner ferrule can prevent the front side of the optical element from being easily damaged.

When the user wants to clean the end face of the optical fiber cable, for example, the end face is exposed by creating a state in which the outer ferrule receives a predetermined external pressure in the proximal direction. It is possible to clean it. Therefore, maintenance is easy.

The socket of the optical connector according to the present invention to be engaged with the plug of the optical connector according to the present invention as described above,
For example, in the insertion hole portion into which the front end sides of the inner ferrule and the outer ferrule of the plug of the optical connector are inserted, and the element fixing chamber portion provided in the inner side of the insertion hole portion so as to communicate with the insertion hole portion. It has a fixed optical element,
The back side of the insertion hole is provided with a back side tapered surface that contacts the tip side of the inner ferrule, and the front side is provided with a front side tapered surface that contacts the tip side of the outer ferrule. Therefore, the inner ferrule may be prevented from being inserted by the back taper surface and the outer ferrule may be blocked by the front taper surface before the front surface of the optical element by a predetermined minute distance.

By thus constructing the socket of the optical connector according to the present invention, the features of the plug of the optical connector according to the present invention when engaged with the socket of the optical connector as described above (Basically, there is no possibility that the front side of the optical element will be damaged, etc.).

The optical connector according to the present invention comprising the plug and socket of the optical connector according to the present invention as described above,
It is preferable that a retaining mechanism for preventing mutual disengagement be provided. As a result, it becomes possible to use an elastic body portion having a large biasing force, and when carrying an optical fiber cable with a plug, the plug can reliably protect the end surface of the optical fiber cable against a large external pressure. it can. In addition, the retaining mechanism can further prevent the above-mentioned scratches from occurring, and can further improve the proper signal transmission between the plug and the socket in the optical connector.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of an optical connector according to a first embodiment of the present invention, FIG. 1A showing a state in which a plug of an optical connector starts to engage with a socket; FIG. 6B is a diagram showing a state where the plug of the optical connector is completely engaged with the socket.

FIG. 2 is a schematic side sectional view of an optical connector according to a second embodiment of the present invention, FIG. 2 (A) showing a state in which a plug of the optical connector starts to engage with a socket; FIG. 6B is a diagram showing a state where the plug of the optical connector is completely engaged with the socket.

FIG. 3 is a schematic cross-sectional plan view showing an optical connector according to a third embodiment of the present invention.

4A and 4B are diagrams showing an optical connector according to a fourth embodiment of the present invention, wherein FIG. 4A is a schematic side view and FIG. 4B is a schematic sectional view in a plan view.

FIG. 5 is a schematic cross-sectional view showing an optical connector according to a fifth embodiment of the present invention, in which a housing part of a plug and a housing part side of a socket are not shown.

FIG. 6 is a schematic side sectional view of an optical connector according to a sixth embodiment of the present invention, in which FIG. 6 (A) shows a state in which a plug of the optical connector starts to engage with a socket; FIG. 6B is a diagram showing a state where the plug of the optical connector is completely engaged with the socket.

FIG. 7 is a view showing the optical element used in the optical connector according to the first to fifth embodiments of the present invention, in which the tip end surface of the expanded shape portion of the axial core portion of the optical fiber cable is the thick portion of the optical element. The inside of the hole surrounded by (inside of the front surface of the thick part) is not in contact with the lens of the optical element but is in contact with the inclined surface of the thick part. FIG.

FIG. 8 is a view in which an optical element used in the optical connector according to the first to fifth embodiments of the present invention is provided with a step portion, and the tip surface of the expanded shape portion of the axial core portion of the optical fiber cable is provided in the step portion. It is a schematic explanatory drawing which shows the state which contacted.

[Explanation of symbols]

100 fiber optic cable 110a Tip surface (end surface) 110b Sliding contact part 200 plug 210 housing 220 ferrule 220a tip surface 280 elastic body 800 socket

Claims (5)

(57) [Claims] 1. A plug of an optical connector, which is provided on an end side of an optical fiber cable and engages with a socket of an optical connector, wherein a housing part fixed to the end part and an optical fiber cable from inside the housing part are provided. A ferrule that slidably projects along the socket and that detachably engages with the insertion hole portion of the socket; and an elastic body portion that biases the ferrule toward the tip side thereof. The cable has a sliding contact portion with a ferrule having a dimension longer than the dimension along the optical fiber cable of the ferrule on its end side, the ferrule is not in a predetermined engagement state with a socket, and the ferrule has a proximal end. The end face of the optical fiber cable is provided with this ferrule by the elastic body portion in the state where it is not subjected to an external pressure exceeding a predetermined lateral direction. The ferrule is stored inside the ferrule with respect to the distal end surface of the ferrule, and the ferrule is in a predetermined engagement state with the socket, or the ferrule has a predetermined direction in the proximal direction. The plug of an optical connector, wherein the end face of the optical fiber cable can project from the end face of the ferrule by a predetermined dimension in the state of receiving the above external pressure. 2. A plug of an optical connector which is provided on an end side of an optical fiber cable and engages with a socket of the optical connector, wherein the housing part is fixed to the end part side and the housing part protrudes from the inside of the housing part. An outer ferrule that is detachably engaged with the front side portion of the insertion hole of the socket, and is disposed inside the outer ferrule, and is projectingly provided so as to firmly hold the end portion side of the optical fiber cable from the housing portion, Removably engaged with the back side of the insertion hole of the socket,
An inner ferrule that allows the outer ferrule to slide and an elastic body portion that urges the outer ferrule toward the tip side thereof are provided. The inner ferrule has a tip surface of the inner ferrule and an optical fiber cable. The end faces are formed to be substantially at the same position, and the dimension along the optical fiber cable of the inner ferrule is formed longer than the dimension along the optical fiber cable of the outer ferrule, and the outer ferrule is in a predetermined engagement state with the socket. If the outer ferrule is not present and the outer ferrule is not subjected to an external pressure in the proximal direction of the outer peripheral ferrule, the outer ferrule is urged by the elastic body portion so that the outer ferrule is urged by the elastic body portion. Stored on the inner side of the outer ferrule than the tip surface of the If the outer ferrule is in a predetermined engagement state with the socket, or if the outer ferrule is subjected to an external pressure of a predetermined amount or more in the proximal direction, the end surface of the optical fiber cable is the tip surface of the outer ferrule. A plug of an optical connector, which is capable of protruding by a predetermined size. 3. The plug of the optical connector according to claim 1,
In an optical connector having an optical connector socket that engages with a plug of the optical connector, the socket of the optical connector includes an insertion hole portion into which a tip side of a ferrule of the plug of the optical connector is inserted, and the insertion hole portion. It is equipped with an optical element that is fixed to the element fixing chamber that is provided on the back side of the insertion hole so as to communicate with each other, and the back side of the insertion hole that contacts the tip side of the ferrule. An optical connector, which is provided with a tapered surface and prevents the ferrule from being inserted before the front surface of the optical element. 4. A plug of the optical connector according to claim 2,
In an optical connector having an optical connector socket that engages with a plug of this optical connector, the socket of the optical connector has an insertion hole portion into which a tip side of an inner ferrule and an outer ferrule of the plug of the optical connector is inserted. It is equipped with an optical element that is fixed to the element fixing part room provided on the back side of the insertion hole so as to communicate with this insertion hole, and the tip of the inner ferrule is on the back side of the insertion hole. Is provided with a back side taper surface that abuts the front side of the outer ferrule, and a front side taper surface that abuts the tip side of the outer ferrule is provided in the front side portion thereof. The optical connector is characterized in that the insertion of the inner ferrule is blocked by the back tapered surface and the insertion of the outer ferrule is blocked by the front tapered surface. 5. The optical connector according to claim 3, further comprising a retaining prevention mechanism for preventing mutual disconnection.