JP6448486B2 - Optical fiber and light guide member - Google Patents

Description

  The present invention relates to an optical fiber and a light guide member.

  Conventionally, various laser processing apparatuses for performing processing (welding, soldering, exposure, drilling, etc.) by irradiating a workpiece with laser light have been developed. In addition to concentrating the laser beam and irradiating the laser beam in a spot shape when performing laser processing, for example, several processing apparatuses that perform laser irradiation so that the irradiation shape on the irradiation surface becomes a ring shape have been proposed. (For example, patent documents 1-3).

  As the processing for making the irradiation shape of the laser beam into a ring shape, when the welding portion of the workpiece is a ring shape, welding processing that collectively welds by irradiating the welding portion of the workpiece with a ring-shaped laser beam, Soldering is performed by irradiating a ring-shaped laser to the ring-shaped terminal portion when the soldering target is a ring-shaped terminal provided on the board and a rod-shaped terminal of an electronic component inserted therein. Examples include processing. In this soldering process, the laser beam is not irradiated onto the electronic component through the gap between the annular terminal and the rod-shaped terminal, so that it is possible to avoid the problem that a part of the electronic component is burned and deteriorated. .

JP 2005-28428 A JP 2006-229075 A JP 2011-143420 A

  However, the conventional techniques described in Patent Documents 1-3 use one or more expensive lenses having a special shape such as a cone lens, and a circular laser beam is converted into a ring-shaped laser beam using this lens. Since the optical system is optically converted into an optical system, the configuration of the optical system is inevitable and expensive, or the apparatus has a structure including a light collecting member and a rotating mechanism that rotates the light collecting member. There was a problem that it became large and expensive.

  This invention is made | formed in view of this point, The place made into the objective is to provide the optical fiber and light guide member which can implement | achieve a ring-shaped irradiation shape cheaply.

  The optical fiber of the present invention has a configuration in which the core at one end is hollow and at least a part of the core at the other end is solid.

  The core at the other end may be solid.

  The outer diameter of the core at the one end may be larger than the outer diameter of the solid core.

  The first light guide member of the present invention uses the above-described optical fiber, the other end is the light incident side, and a cap member that closes the hollow opening is connected to the core of the one end. It has the composition which is. The thickness of the cap member is preferably 0.1 mm or more and 2 mm or less.

  The second light guide member of the present invention is a light guide member using an optical fiber, and a light-transmitting tip member is connected to an end portion of the output side of the optical fiber. The surface has a light-transmitting region and at least one light-impermeable region, and at least one of the light-impermeable regions has a configuration surrounded by the light-transmitting region. That is, there is one or a plurality of opaque regions, and at least one of them is surrounded by the transparent region.

  The opaque region may be a depression formed on the exit surface of the tip member.

  The tip member may include a first portion connected to the optical fiber and a second portion having the emission surface, and the first portion may be a quadrangular prism.

  The optical fiber and the light guide member of the present invention can irradiate light with a ring-shaped irradiation shape on the irradiation surface with a simple structure.

1 is a schematic perspective view of an optical fiber according to Embodiment 1. FIG. 1 is a schematic plan view of an optical fiber according to Embodiment 1. FIG. 3 is a schematic diagram illustrating an end face of one end of the optical fiber according to Embodiment 1. FIG. It is the irradiation shape of the light radiate | emitted from the optical fiber which concerns on Embodiment 1. FIG. It is a figure which shows intensity distribution of the light in CC line of FIG. 4A. 3 is a schematic plan view of a light guide member according to Embodiment 1. FIG. 6 is a schematic plan view of a light guide member according to Embodiment 2. FIG. 6 is a schematic plan view of a light guide member according to Embodiment 3. FIG. FIG. 6 is a schematic diagram illustrating an emission end face of a light guide member according to Embodiment 3. 6 is a schematic plan view of a light guide member according to Embodiment 4. FIG. FIG. 6 is a schematic diagram illustrating an emission end face of a light guide member according to a fourth embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its application, or its use. In the following drawings, components having substantially the same function are denoted by the same reference numerals for the sake of brevity.

(Embodiment 1)
The optical fiber according to Embodiment 1 is shown in FIGS. In the optical fiber 100 of the present embodiment, the core 10 at one end is hollow, and the core 20 at the other end and the core 30 at an intermediate portion between both ends are solid. The term “solid” means that the contents are clogged, which is the opposite of the hollow state. The hollow core 10 at one end has a larger outer diameter than the solid core 30 at the middle and the core 20 at the other end.

  Although the core is surrounded by the clad 50, the clad 50 is removed from the cores 10 and 20 at both ends for the incidence and emission of light. The clad 50 is made of a material having a refractive index lower than that of the core, and serves to confine light in the core. The core can be made of quartz or plastic such as PMMA, PC, or PS, but it is preferable to use quartz for the propagation of high energy laser light for processing. The outer side of the clad 50 may be further covered with a protective coating. When an ultraviolet curable resin such as urethane acrylate is used for the cladding of the quartz core, the cladding may also serve as a protective coating.

  In the optical fiber 100 of the present embodiment, since the hollow portion 40 is present in the core 10 at one end, when the end surface of the core 10 at one end is observed along the axial direction, a ring as shown in FIG. The core material exists in the shape, that is, the portion sandwiched between two concentric circles, and the inside is a hollow and empty portion.

  In the optical fiber 100 of the present embodiment, the other end side is an incident side, and one end side is an emission side. FIG. 4A shows an irradiation shape in which light emitted from one end of the optical fiber 100 of the present embodiment is irradiated onto a plane perpendicular to the optical axis. The irradiated light has a ring shape and has an intensity distribution as shown in FIG. 4B. That is, the light incident on the core 20 at the other end passes through the solid core 30 and reaches the hollow portion 40 at one end. The hollow portion 40 has a lower refractive index than the core. Therefore, the light is reflected at the interface between the hollow portion 40 and the core, travels only in the core, and is emitted as ring-shaped light from the emission end. The end on the other end side of the hollow portion 40 (boundary portion with the solid portion) is the apex of a cone having an angle of (90 degrees-critical angle) or less with respect to the optical axis so that light is not reflected to the incident side. It is preferable that it is the shape of this.

  There are various methods for producing the optical fiber 100 according to the present embodiment, but an example is a method in which an optical fiber having a hollow core (cylindrical optical fiber) is fused to an end of an optical fiber having a solid core. Can be mentioned. In this method, one end of a hollow optical fiber is melted with heat to close the hole, and the outer diameter is made equal to that of a solid core, and the optical fiber having a solid core is thermally fused. With this method, the outer diameter of the hollow core and the outer diameter of the solid core can be arbitrarily selected.

  When the optical fiber 100 according to the present embodiment is used, the irradiation shape can be easily made into a ring shape at low cost without particularly using a member (special lens or optical operation system device) other than the optical fiber. By using a laser generator as a light source, ring-shaped heating can be easily performed by the optical fiber 100 according to the present embodiment. As described above, since there are various processes in which heating is performed in a ring shape and the central portion is not desired to be heated, the optical fiber 100 according to this embodiment can be used for such processes. Further, the outer diameter and inner diameter of the core 10 at one end can be freely set regardless of the diameters of the core 20 at the other end and the core 30 at the intermediate portion by using the above-described production method. Therefore, the outer diameter and inner diameter of the core 10 at one end can be easily set according to the size of the heated portion of the workpiece.

<Light guide member>
FIG. 5 shows a light guide member using the optical fiber 100 according to this embodiment. In this light guide member, a cap member 60 is connected to the end face of the core 10 at one end of the optical fiber 100 according to the present embodiment to close the opening of the hollow portion 40. The cap member 60 is preferably made of the same material as the optical fiber core. The thickness of the cap member 60 is a thickness that maintains the ring shape of the emitted light and does not decrease the intensity of the emitted light. Specifically, the thickness is preferably 0.1 mm or more and 2 mm or less. By connecting the cap member 60, foreign matter is prevented from entering the hollow portion 40 of the core 10 at one end from the outside. The cap member 60 may be fused to the optical fiber, may be adhered to the optical fiber using an adhesive, or may be mechanically pressed and connected.

(Embodiment 2)
FIG. 6 shows an optical fiber according to Embodiment 2 and a light guide member using the optical fiber. In the optical fiber 110 of the present embodiment, the hollow portion 41 exists in the core 11 at one end portion and the core 31 at the intermediate portion, and the core 21 at the other end portion is solid. As in the first embodiment, the core is surrounded by the clad 51, and the cap member 60 is connected to the end surface of the core 11 at one end.

  The optical fiber 110 according to the present embodiment can be formed by melting the core 21 at the other end of the hollow optical fiber to make it solid. Alternatively, it can be produced by fusing a solid short optical fiber to the other end of the hollow optical fiber. In the optical fiber 110 according to the present embodiment, the light incident on the core 21 at the other end does not go out to the hollow portion 41 in the core 31 at the middle portion, but only inside the core material having a ring shape in cross section. It passes through and exits from the exit end face of the core 11 at one end. The light passes through the cap member 60 and is emitted as ring-shaped light on a plane perpendicular to the optical axis. Also in the present embodiment, the end on the other end side of the hollow portion 41 is in the shape of the apex of a cone having an angle of (90 degrees-critical angle) or less with respect to the optical axis so that light is not reflected to the incident side. Preferably there is.

  Similarly to the optical fiber 100 and the light guide member according to the first embodiment, the irradiation shape of the optical fiber 110 according to the second embodiment and the light guide member using the same can be easily made into a ring shape at a low cost.

(Embodiment 3)
A light guide member according to Embodiment 3 is shown in FIGS. In the light guide member according to the present embodiment, a light transmitting tip member 70 is connected to the light emitting end of the optical fiber 120. The optical fiber 120 has a continuous core from the core 12 at one end to the core 22 at the other end, and has a cladding 52. The tip member 70 is made of a translucent member such as quartz, glass, or transparent plastic, and is preferably made of the same material as the core of the optical fiber 120. The connection between the optical fiber 120 and the tip member 70 is preferably a connection by fusion or adhesion.

  In this embodiment, the tip member 70 has a cylindrical shape that is coaxial with the central axis of the optical fiber 120 and has a diameter larger than that of the core 12 at one end, and is a surface opposite to the connection surface with the optical fiber 120 (light A conical recess 81 (the bottom surface of the cone is located on the same plane as the light exit surface) is formed on the exit surface side. The light emitted from the optical fiber 120 spreads in the tip member 70 so as to pass through the entire cross section of the tip member 70.

  When the light emission surface of the tip member 70 is observed, as shown in FIG. 8, a ring-shaped translucent region 83 exists around the recess 81. Here, since the conical shape of the depression 81 is set to an angle of (90 degrees-critical angle) or less with respect to the central axis, the light that enters the tip member 70 from the optical fiber 120 is reflected on the surface of the depression 81 (cone The light is not emitted from this part. That is, the portion of the depression 81 becomes an opaque region. The opaque region is surrounded by the transparent region 83, and the light emitted from the tip member 70 has a ring shape on a plane perpendicular to the optical axis. That is, the tip member 70 emits the emitted light having the same shape as that of the ring-shaped translucent region 83.

  The light guide member according to the present embodiment can use various optical fibers for light guide according to applications. The optical fiber does not require a hollow portion. In other words, the existing optical fiber can be used as it is. The shape and irradiation range of the emitted light can be adjusted by the shape and size of the tip member 70. Therefore, a light guide member that irradiates light having a desired shape and irradiation range can be easily produced and provided at low cost.

(Embodiment 4)
The light guide member according to the fourth embodiment shown in FIGS. 9 and 10 is different from the third embodiment in the configuration of the tip member 75, and the optical fiber 120 is the same as that in the third embodiment. Do.

  The tip member 75 of the present embodiment includes a first portion 74 connected to the optical fiber 120 and a second portion 72 having an exit surface. Both are made of a translucent material. The first portion 74 is a prism that is coaxial with the central axis of the optical fiber 120 and has a shorter diameter than the core 12 at one end. The second portion 72 is coaxial with the first portion 74 and has a cross-sectional area larger than that of the first portion 74. The overall shape is a rounded corner portion of a prism that is similar to the first portion 74. The light exit surface has a further structure as will be described later.

  The first portion 74 spreads the light distribution over the entire cross section of the first portion 74 in a plane perpendicular to the optical axis, and makes the light intensity distribution in the plane uniform. As light enters the second portion 72 from the first portion 74, the light distribution further extends across the entire cross section of the second portion 72.

  The second portion 72 includes translucent areas 86, 86,... And non-translucent areas on the exit surface, and there are six translucent areas 86, 86,. It is a ring-shaped surface that exists above. The opaque region exists between the first recesses 82, 82,... Existing inside the ring shape of the transparent regions 86, 86,. The second depressions 84, 84,... Are two types of depressions. The first depressions 82, 82,... Are conical depressions, and the opening that is the bottom surface portion is surrounded by the light-transmitting regions 86, 86,. The second depressions 84, 84,... Are V-groove depressions whose width and depth change depending on the distance between the light-transmitting regions 86, 86 adjacent to each other (distance between ring outer edges).

  The first depressions 82, 82,..., And the second depressions 84, 84,... Have their slopes set so as to have an angle of (90 degrees-critical angle) or less with respect to the central axis of the optical fiber 120. Therefore, even if light enters the inclined surface from the inside of the second portion 72, the light is reflected and is not emitted from the depressions.

  In the light guide member of the present embodiment, light in a ring shape on a surface perpendicular to the optical axis is emitted in two rows of three, a total of six. Thereby, six to-be-heated objects can be heated simultaneously, and many to-be-heated objects can be heated 6 times as compared with the light guide member of Embodiment 3. In addition, it is possible to perform six processes such as heating and light irradiation at a time with one light source.

(Other embodiments)
The above-described embodiment is an exemplification of the present invention, and the present invention is not limited to these examples, and these examples may be combined or partially replaced with known techniques, common techniques, and known techniques. Also, modified inventions easily conceived by those skilled in the art are included in the present invention.

  The opaque region provided in the tip member is not limited to the conical or V-groove depression, and any shape or reflection principle may be used as long as it reflects light.

  You may connect the cap member similar to Embodiment 1,2 to the output end surface of the front-end | tip member of Embodiment 3,4. Further, the shape of the tip member of Embodiments 3 and 4 is not particularly limited, and the light-transmitting region may not be a circular ring shape, may be an elliptical or polygonal ring shape, or other than a ring shape The shape may be acceptable.

  In Embodiment 4, the first part and the second part of the tip member may be made of the same translucent material or different materials.

10, 11 Core 20 at one end, 21 Core 60 at the other end Cap member 70, 75 Tip member 72 Second portion 74 First portion 81 Recess 82 First recess 83, 86 Translucent region 84 Second recess 100 Optical fiber 110 Optical fiber 120 Optical fiber

Claims (4)

A core of one end hollow, a light guide member using an optical fiber medium Ru solid der at least part of the other portion of the core,
The other end is the light incident side,
A cap member for closing the hollow opening is connected to the core at the one end ,
The cap member is made of the same material as the core,
A light guide member that irradiates light having a ring-shaped irradiation shape on an irradiation surface . The light guide member according to claim 1 , wherein the cap member has a thickness of 0.1 mm to 2 mm. The light guide member according to claim 1 or 2, wherein the core at the other end is solid. The light guide member according to any one of claims 1 to 3, wherein an outer diameter of the core at the one end is larger than an outer diameter of the solid core.

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