1. A method of splicing optical fibers, comprising:

the first and second optical fibers for mating have mating end faces,

at least one end of the butt joint end face of the first optical fiber and the second optical fiber is subjected to melting treatment, so that the end face is a curved surface;

locking the first and second optical fibers at a butted position by a fiber locking part.

2. An optical fiber splicing device characterized by:

the first and second optical fibers for mating have mating end faces,

at least one end of the butt joint end face of the first optical fiber and the second optical fiber is subjected to melting treatment, so that the end face is a curved surface;

the optical fiber splicing device locks the first optical fiber and the second optical fiber at a butted position by an optical fiber locking portion.

3. The optical fiber splicing device of claim 2 wherein:

the optical fiber locking part includes:

the optical fiber splicing device comprises an inner shell, a first optical fiber and a second optical fiber, wherein the inner shell is provided with a V-shaped groove used for limiting the first optical fiber and the second optical fiber to be spliced, the V-shaped groove is provided with a first avoiding groove at the position of the butt joint end face of the first optical fiber and the second optical fiber, and the first avoiding groove is used for accommodating a protruding part at the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

a cover plate, wherein the first optical fiber and the second optical fiber are limited in the V-shaped groove through the cooperation of the cover plate and the inner shell; a second avoidance groove is formed in the position, located at the butt joint end face of the first optical fiber and the second optical fiber, of the cover plate, and the second avoidance groove is used for accommodating a protruding portion of the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

and the locking part is used for fixing the cover plate and the inner shell relatively.

4. An optical fiber connector, characterized by:

the front end of the optical fiber connector is provided with a pre-buried optical fiber;

the optical fiber connector is provided with an optical fiber locking part, and the embedded optical fiber and the external optical fiber butted with the embedded optical fiber are locked at a butting position through the optical fiber locking part;

and at least one end of the butt joint end face of the external optical fiber and the embedded optical fiber is subjected to melting treatment, so that the end face is a curved surface.

5. The fiber optic connector of claim 4, wherein:

the optical fiber locking part includes:

the front end of the inner shell is used for fixedly assembling the ceramic ferrule of the embedded optical fiber; the inner shell is provided with a V-shaped groove used for limiting the embedded optical fiber and the external optical fiber, a first avoiding groove is arranged at the position of the butt joint end face of the external optical fiber and the embedded optical fiber, and the first avoiding groove is used for accommodating a protruding part at the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

the cover plate is used for being matched with the inner shell to limit the embedded optical fibers and the external optical fibers in the V-shaped groove, and a second avoidance groove is formed in the position, located at the butt joint end face of the first optical fibers and the second optical fibers, of the cover plate; the second avoidance groove is used for accommodating a protruding part of the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

and the locking part is used for fixing the cover plate and the inner shell relatively.

6. The fiber optic connector of claim 5, wherein:

and measuring the width of the first avoidance groove and the second avoidance groove by taking the line where the V-shaped groove is positioned as a reference, wherein the width of the second avoidance groove is greater than that of the first avoidance groove.

7. The fiber optic connector of claim 5, wherein:

the locking portion is configured to have at least a clamp spring for fixing the cover plate and the inner case relatively.

8. The fiber optic connector of claim 5, wherein:

the locking part is configured to be provided with at least a sleeve, the sleeve is provided with a first step, the box cover is provided with a second step, the sleeve is sleeved on the inner shell and the cover plate, and the cover plate and the inner shell are relatively fixed through the matching of the first step and the second step.

9. The fiber optic connector of claim 5, wherein:

the inner shell at least comprising the V-shaped groove and the first avoidance groove is integrally formed; or the inner shell comprises an inserting part and a V-shaped groove piece provided with the first avoiding groove, and the V-shaped groove piece is relatively fixed through the inserting part to form the inner shell.

10. The fiber optic connector of claim 4, wherein:

and the butt joint end faces of the external optical fiber and the embedded optical fiber are subjected to melting treatment.

Background

The existing field assembly type optical fiber connectors are mainly divided into two types, one is a fused end type optical fiber connector, and the other is a pre-embedded type optical fiber connector; the biggest difference between the end-melting type optical fiber connector and the pre-embedded type optical fiber connector is as follows: the end-melting type optical fiber connector mainly melts the end face of the external optical fiber through an end melting machine to form an arc face, so that the damage caused by cutting the external optical fiber is compensated, the communication quality is ensured, then the external optical fiber is fixed in the end-melting type optical fiber connector, and the arc end face extends out of a ceramic ferrule of the connector; a section of pre-buried optical fiber is pre-buried in a ceramic ferrule of the pre-buried optical fiber connector when leaving a factory, the pre-buried optical fiber needs to be ground after being fixed in the ceramic ferrule to ensure the tidiness of the end face of the pre-buried optical fiber, the later half part of the pre-buried optical fiber is simply cut, matching fluid or matching paste is pre-filled in the pre-buried optical fiber connector, the matching fluid or the matching paste mainly plays the roles of reducing the refractive index and filling the damage of the cut end face, and the matching fluid is matched with the pre-buried optical fiber after the external optical fiber is cut, so that the butt joint is completed in the optical fiber connector;

for example, patent No. 201420739809.1 entitled optical fiber end face polishing and detecting device, the melting end or the melting end processing mainly melts the optical fiber end face through electric arc, and forms a smooth arc surface after cooling, so as to eliminate the problems of uneven end face and cut mark caused by optical fiber cutting, make up for the damage caused by cutting the external optical fiber, and achieve the polishing effect; the fusing machine is equipment for realizing the functions;

in the prior art, the external optical fiber is fixed by either a fused end type optical fiber connector or a pre-embedded optical fiber connector mainly through locking in a clamping spring or sleeve manner; as disclosed in patent application No. 200980125713.8 entitled optical connector and method of assembling an optical connector, the use of a clamp spring and the securing of an external optical fiber by securing a V-groove and a cover plate located within the clamp spring is achieved; for example, patent No. 201920286363.4 entitled "fixing component for field-assembled connector for loose-tube optical cable" discloses a structure for fixing a sleeve tube with a step shape in cooperation with a cover plate with a step shape; the fixing structures are the main using methods in the prior art, and other fixing methods are also available, which are not exemplified here.

For the prior art, although the end-melting type optical fiber connector is convenient and quick, the consistency of the end face of the ceramic ferrule and the consistency of the end face of the optical fiber per se cannot be completely ensured by the end-melting treatment of the external optical fiber end face of the pre-embedded optical fiber connector; the pre-buried optical fiber connector needs to use matching fluid or matching paste, so that the optical fiber connector has additional requirements on transportation, storage and manufacture, and the price of the matching fluid or the matching paste is higher.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides an optical fiber splicing method, an optical fiber splicing device and an optical fiber connector.

The technical scheme provided by the invention is as follows:

a method for splicing optical fibers includes providing a first optical fiber,

the first and second optical fibers for mating have mating end faces,

at least one end of the butt joint end face of the first optical fiber and the second optical fiber is subjected to melting treatment, so that the end face is a curved surface;

locking the first and second optical fibers at a butted position by a fiber locking part.

The present invention also provides an optical fiber splicing device,

the first and second optical fibers for mating have mating end faces,

at least one end of the butt joint end face of the first optical fiber and the second optical fiber is subjected to melting treatment, so that the end face is a curved surface;

the optical fiber splicing device locks the first optical fiber and the second optical fiber at a butted position by an optical fiber locking portion.

Preferably, the optical fiber locking part includes:

the optical fiber splicing device comprises an inner shell, a first optical fiber and a second optical fiber, wherein the inner shell is provided with a V-shaped groove used for limiting the first optical fiber and the second optical fiber to be spliced, the V-shaped groove is provided with a first avoiding groove at the position of the butt joint end face of the first optical fiber and the second optical fiber, and the first avoiding groove is used for accommodating a protruding part at the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

a cover plate, wherein the first optical fiber and the second optical fiber are limited in the V-shaped groove through the cooperation of the cover plate and the inner shell; a second avoidance groove is formed in the position, located at the butt joint end face of the first optical fiber and the second optical fiber, of the cover plate, and the second avoidance groove is used for accommodating a protruding portion of the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

and the locking part is used for fixing the cover plate and the inner shell relatively.

The invention also provides an optical fiber connector,

the front end of the optical fiber connector is provided with a pre-buried optical fiber;

the optical fiber connector is provided with an optical fiber locking part, and the embedded optical fiber and the external optical fiber butted with the embedded optical fiber are locked at a butting position through the optical fiber locking part;

and at least one end of the butt joint end face of the external optical fiber and the embedded optical fiber is subjected to melting treatment, so that the end face is a curved surface.

Preferably, the optical fiber locking part includes:

the front end of the inner shell is used for fixedly assembling the ceramic ferrule of the embedded optical fiber; the inner shell is provided with a V-shaped groove used for limiting the embedded optical fiber and the external optical fiber, a first avoiding groove is arranged at the position of the butt joint end face of the external optical fiber and the embedded optical fiber, and the first avoiding groove is used for accommodating a protruding part at the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

the cover plate is used for being matched with the inner shell to limit the embedded optical fibers and the external optical fibers in the V-shaped groove, and a second avoidance groove is formed in the position, located at the butt joint end face of the first optical fibers and the second optical fibers, of the cover plate; the second avoidance groove is used for accommodating a protruding part of the edge of the end face of the first optical fiber and/or the second optical fiber after the end face is subjected to melting treatment;

and the locking part is used for fixing the cover plate and the inner shell relatively.

Preferably, when the width of the first avoidance groove and the width of the second avoidance groove are measured by taking a line along which the V-shaped groove is located as a reference, the width of the second avoidance groove is greater than the width of the first avoidance groove.

Preferably, the locking portion is configured to have at least a clamp spring for fixing the cover plate and the inner housing relative to each other.

Preferably, the locking portion is configured to have at least a sleeve, the sleeve is provided with a first step, the box cover is provided with a second step, the sleeve is sleeved on the inner housing and the cover plate, and the cover plate and the inner housing are relatively fixed through the cooperation of the first step and the second step.

Preferably, the inner shell at least comprising the V-shaped groove and the first avoidance groove is integrally formed; or the inner shell comprises an inserting part and a V-shaped groove piece provided with the first avoiding groove, and the V-shaped groove piece is relatively fixed through the inserting part to form the inner shell.

Preferably, the butt joint end faces of the external optical fiber and the embedded optical fiber are subjected to melting treatment

The invention has the beneficial effects that:

according to the optical fiber splicing method, the optical fiber splicing device and the optical fiber connector, at least one end face of the embedded optical fiber or the external optical fiber is subjected to melting treatment, so that the communication quality can be enhanced during butt joint, and stable optical communication can be realized even at the butt joint position of the embedded optical fiber in the optical fiber connector without using matching fluid or matching paste.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the optical fiber connector of the present invention;

FIG. 2 is a schematic structural diagram of an inner housing of the optical fiber connector of the present invention, which employs metal V-shaped groove pieces;

FIG. 3 is a schematic structural diagram of a cover plate of the optical fiber connector of the present invention;

FIG. 4 is a schematic diagram of a fiber optic connector of the present invention secured with a clamping spring;

FIG. 5 is a schematic view of the optical fiber connector of the present invention secured with a ferrule;

FIG. 6 is a schematic diagram of the internal structure of the fiber butt joint of the present invention;

FIG. 7 is a schematic view of an assembled configuration of the fiber butt joint of the present invention;

FIG. 8 is a schematic view of the optical fibers of the present invention in a mated state; wherein, the attached drawing a is the state of carrying out end melting, and the attached drawing b is the state of carrying out end melting at one end;

reference numerals:

the first embodiment:

the optical fiber connector comprises a ceramic ferrule 1, a pre-buried optical fiber 2, an inner shell 3, a V-shaped groove 4, a first avoidance groove 5, an external optical fiber 6, a plug-in part 7, a metal V-shaped groove sheet 8, a cover plate 9, a second avoidance groove 10, a clamping spring 11 and a sleeve 12;

second embodiment:

inner housing 13, V-shaped groove 14, first avoidance groove 15, cable fixing clip 16 and cover plate 17.

Detailed Description

The present invention will be further described with reference to the accompanying drawings, wherein the description is made in the specification of a melt-end process, which is a process for melt-processing an end face of an optical fiber; in the prior art, the end melting treatment of the external optical fiber can be realized by using an end melting machine and other devices, but the external optical fiber is generally directly fixed on the optical fiber connector after the end melting treatment, and the butt joint with the embedded optical fiber in the optical fiber connector is not involved. The butt joint end face of the optical fiber after the melting end processing is a curved surface, the curved surface is a convex surface, the curved surface refers to that the middle part of the end face of the optical fiber is convex after the melting end processing relative to the whole straight end face cut by the cutting knife, the convex part is a fiber core part responsible for signal transmission, the section is an arc-shaped curved surface under an ideal state, and the curved surface is very small.

To reduce duplication of description, the fiber optic connectors are used in this patent for illustration, and the fiber optic splicing method and apparatus are similar to the fiber optic connectors, and those skilled in the art can understand and deduce the corresponding splicing method and apparatus.

A kind of optical fiber connector is disclosed,

the method comprises the following steps:

as shown in fig. 1, a ferrule 1; the ceramic ferrule 1 is a tubular structure, which is mainly used for accommodating optical fibers and is butted with external use ends such as adapters and the like;

the embedded optical fiber 2 is fixed on the ceramic ferrule 1, and is provided with a front part fixed on the ceramic ferrule 1 and a rear part extending out of the ceramic ferrule 1; the end face of the tail end of the rear part of the embedded optical fiber 2, namely the butt joint end face, can be subjected to end melting treatment; the embedded optical fiber 2 is fixed to the ceramic ferrule 1, which is a mature technology, glue is filled in the ceramic ferrule 1, and then the embedded optical fiber 2 is inserted to realize fixation; the end part of the embedded optical fiber 2 is inevitably stained with glue when being inserted, and meanwhile, the fixed embedded optical fiber 2 may extend out of the front end of the ceramic ferrule 1 too much, so that the fixed ceramic ferrule 1 and the embedded optical fiber 2 need to be ground together, the fixed ceramic ferrule 1 and the embedded optical fiber 2 can be well adapted to an external use end through grinding, and meanwhile, required shapes or angles can be ground according to different external use ends; the fusion-end processing of the embedded fiber 2 can be performed either before it is fixed to the ferrule 1 or after it is fixed to the ferrule 1.

An inner housing 3 for configuring the ferrule 1; the inner shell 3 is provided with a V-shaped groove 4 for limiting the rear part of the embedded optical fiber 2, a first avoiding groove 5 is arranged at the tail end face of the V-shaped groove 4 positioned at the rear part of the embedded optical fiber 1, and the first avoiding groove 5 is used for accommodating a protruding part formed by the tail end of the embedded optical fiber 2 subjected to end melting treatment and a protruding part formed by the end melting treatment of an external optical fiber 6 butted with the embedded optical fiber 2; when the embedded optical fiber 2 or the external optical fiber 6 is subjected to melting end processing, the end face of the optical fiber enters a melting state after passing through an electric arc and is cooled, and the end face of the optical fiber after entering the melting state expands due to liquid tension, so that a smaller protruding part slightly outward in the radial direction is formed on the edge while the end face forms a curved surface, and the first avoidance groove 5 and the second avoidance groove 10 are arranged to prevent the protruding part from tilting when the optical fiber is butted in the V-shaped groove 4, so that a cover plate cannot be accurately buckled or the butt joint of the optical fiber is unstable; the V-shaped groove 4 is tightly matched with the optical fiber main body, so that in order to ensure that the embedded optical fiber 2 is tightly butted with the external optical fiber 6, a corresponding first avoidance groove 5 needs to be formed in the inner shell 3; of course, the portion protruding from the diameter of the embedded optical fiber 2 or the external optical fiber 6 is generally very small and generally not larger than 0.01mm, so the depth of the first avoidance groove 5 is larger than the depth, and the length of the arc protruding portion (the most previous of the whole arc-shaped end surface to the optical fiber main body) is not larger than 0.02mm, so the state of fusion processing and butt joint of the embedded optical fiber and the external optical fiber is considered, the width of the first avoidance groove 5 is generally larger than 0.05mm, of course, the first avoidance groove 5 is not too wide, and if the width is too wide, the embedded optical fiber 2 and the external optical fiber 6 are easily bent to cause poor butt joint during butt joint.

As shown in fig. 2, in addition, the inner housing 3 may be formed by integrally molding the V-shaped groove 4 and the first avoiding groove 5 during injection molding, and if the injection molding process is difficult, the inner housing may also include an insertion part 7 and a V-shaped groove piece 8 provided with the first avoiding groove 5, and the V-shaped groove piece 8 is relatively fixed by the insertion part 7, so as to form the inner housing 3; due to the properties of the material, the V-groove segment 8 can be machined into the V-groove 4 and the first avoidance groove 5 with high accuracy and high strength by a cutting process or the like.

The shape of the first avoiding groove 5 may be various, and for the integrally molded injection molded inner housing 3, a diamond-shaped notch similar to that shown in fig. 1 may be formed, or a transverse groove may be directly manufactured when the V-shaped groove piece 8 is adopted as shown in fig. 2, or a transverse groove may be injection molded under the integrally molded condition, and the shape may be determined according to actual conditions and processes.

As shown in fig. 3, the cover plate 9 is configured to limit the rear portion of the embedded optical fiber 2 and the external optical fiber 6 butted with the embedded optical fiber 2 in the V-shaped groove 4, and a second avoiding groove 10 matched with the first avoiding groove 5 is disposed at a position of the cover plate 9 corresponding to the first avoiding groove 5; when the widths of the first avoidance groove 5 and the second avoidance groove 10 are measured by taking a line where the V-shaped groove 4 is located as a reference, the width of the second avoidance groove 10 is larger than that of the first avoidance groove 5; this is because the relative positions of the first avoidance groove 5, the embedded optical fiber 2 and the external optical fiber 6 are fixed, and the cover plate 9 needs to be carried on the inner housing 3 when in use, so the cover plate 9 has a small movable gap no matter how, in order to ensure that the second avoidance groove 10 does not affect the stability when the embedded optical fiber 2 and the external optical fiber 6 in the first avoidance groove 5 are butted, that is, the width of the second avoidance groove 10 is at least the designed movable gap when the first avoidance groove 5 plus the cover plate 9 are installed on the inner housing 3; certainly, the second avoiding groove 10 should not be too wide, and it needs to be ensured to be matched with the first avoiding groove 5, so that the butt joint parts of the embedded optical fibers 2 and the external optical fibers 6 in the first avoiding groove 5 and the second avoiding groove 10 cannot move relatively.

A locking portion for fixing the cover plate 9 and the inner housing 3 relative to each other, as mentioned in the background art, which is applicable to the prior art, for example, as shown in fig. 4, the locking portion is configured to have at least a clamp spring 11, and the clamp spring 11 is used for fixing the cover plate 9 and the inner housing 3 relative to each other; the clamp spring 11 is a clamp spring similar to a C-shaped or U-shaped clamp spring, which can clamp the cover plate 9 and the inner housing 3 to be fixed, and is opened by inserting a plug into the gap between the cover plate 9 and the inner housing 3 or expanding the clamp spring 11;

alternatively, as shown in fig. 5, the locking portion is configured to have at least a sleeve 12, the sleeve 12 is provided with a first step, the box cover 9 is provided with a second step, the sleeve 12 is sleeved on the inner housing 3 and the cover plate 9, and the cover plate 9 and the inner housing 3 are relatively fixed by the cooperation of the first step and the second step; the principle is that the first step is pressed onto the second step through interference fit, so that the cover plate 9 is extruded onto the inner shell 3 to be fixed, and the first step is separated from the second step to realize relative separation of the cover plate 9 and the inner shell 3.

In the above embodiment, the optical fiber locking portion is formed by the inner housing, the cover plate and the locking portion.

As shown in fig. 8, the state before the butt joint in the above embodiment is shown in fig. a, the embedded optical fiber and the external optical fiber are subjected to melting end processing, the butt joint end faces are curved surfaces, and the butt joint of the optical fibers is actually the butt joint of the fiber cores inside the optical fibers, so that the most important thing is to ensure that the middle fiber cores of the optical fibers are in butt joint, which is an optimal use mode; of course, the situation shown in fig. b may also be adopted, in which one end is fused, and the other end is not fused, but only cut, and this mode can also enhance the communication effect. Fig. 8 is a schematic view of an ideal state in which the end surface is actually subjected to the melt end treatment in such a manner that the central core portion is protruded and the peripheral edge is slightly recessed.

The external structures of the connector, such as the housing, the tail sleeve and the spring, are all designed according to the prior art, and since the patent does not relate to the above-mentioned modifications and therefore is not described in detail, those skilled in the art will be able to know other structures necessary for the optical fiber connector.

The connector structure has the greatest difference from the prior art that at least one end of the butt joint end face is subjected to end melting treatment, the physical contact between fiber cores of two butt joint optical fibers can be realized during butt joint, and even the gap is not required to be filled with optical fiber refractive index matching fluid or matching paste under the condition of high cleanliness; or even if the optical fiber refractive index matching fluid or the matching paste is adopted, the matching fluid or the matching paste at the lower end can be adopted, and even the similar fluid with the decontamination function can be adopted, rather than the matching fluid or the matching paste with high cost; it should be noted here that the matching fluid or the matching paste is usually an imported product, and has a high price, the difference between the return loss of the domestic corresponding product and the return loss of the imported product is large, especially the return loss difference is large at a low temperature, and the matching fluid or the matching paste can be used without matching fluid or matching paste, or in order to prevent dust and impurity contamination under the condition of a complex dust in a field environment, the matching fluid or the matching paste with low similar parameters can be used, and the main purpose is that the external optical fiber plays a role in isolating dirt such as dust when the connector is inserted into the external optical fiber 6, and the cost is low, and the matching fluid or the matching paste is only used under the complex environment.

For a part of SC and fc type optical fiber connectors, the end face of the ceramic ferrule needs to be inclined by 5 degrees according to the standard requirement, so that the ceramic ferrule needs to be pre-ground, and the situation is not suitable for using a fused end type optical fiber connector without pre-buried optical fibers; for the traditional pre-embedded optical fiber connector, although the end face of the ceramic ferrule can be ground when leaving a factory, matching fluid or matching paste is required to be used; and the fiber connector of this patent when having improved communication quality, can need not even to use matching liquid or match cream to ceramic lock pin terminal surface is through grinding, and communication quality is higher.

The patent also provides an optical fiber splicing method, in particular to a splicing device which is mainly applied to an optical fiber cold connector, a first optical fiber and a second optical fiber which are used for butt joint are provided with butt joint end faces,

at least one end of the butt joint end face of the first optical fiber and the second optical fiber is subjected to melting treatment, so that the end face is a curved surface;

locking the first and second optical fibers at a butted position by a fiber locking part.

As shown in fig. 6 and 7, the structure mainly includes:

specifically, the optical fiber splicing device comprises an inner shell 13, wherein the inner shell 13 is provided with a V-shaped groove 14 for limiting a first optical fiber and a second optical fiber to be spliced, the V-shaped groove 14 is provided with a first avoidance groove 15 at a position where the first optical fiber and the second optical fiber to be spliced are butted, and the first avoidance groove 15 is used for accommodating a protruding part of an end face edge of the first optical fiber and the second optical fiber subjected to end melting processing; two ends of the inner shell 13 are provided with optical cable fixing clips 16, so that two butted optical cables are fixed;

a cover 17, by means of which cover 17 the first and second optical fibers located on the inner housing 13 can be confined within the V-groove 14; a second avoidance groove matched with the first avoidance groove is arranged at the position, corresponding to the first avoidance groove 15, of the cover plate 17, and the second avoidance groove is used for accommodating a protruding part of the end face edges of the first optical fiber and the second optical fiber subjected to end melting treatment; here the structure and function of the second avoidance groove is similar to that described above and will not be repeated here;

and the locking part is used for fixing the cover plate and the inner shell relatively.

The present invention has been described in detail with reference to the preferred embodiments. However, variations and additions to the embodiments will become apparent to those of ordinary skill in the art upon a reading of the foregoing description. It is the intention of the applicants that all such variations and additions fall within the scope of the invention as claimed.