Patent Description:
A fiber-type optical fiber including a core where light proceeds and a clad surrounding the core, is an optical device configured to transmit or provide light, and may be used not only for light transmission but as an apparatus for solar power generation, a display, or a light application device, such as a back light, etc..

The light incidence on the optical fiber may be performed through a facet of one side of the core, and the light output may be performed through a facet of another end or an outer circumference surface where the clad covering the core is formed. The light emission through the facet is in accordance with the conventional optical waveguide structure, and the light output through the outer circumference surface may be used for solar power generation, display, etc. <CIT> discloses a photovoltaic power generation unit using the optical fibers, and power generation system including the same, in which windows formed on the outer circumference surface of an optical fiber may be provided by an opening formed on a clad. <CIT>, also published as <CIT>, discloses an optical fiber scribing tool in a cleaving process. This tool relates to a device for cleaving (segmenting) an optical fiber to a predetermined length, and more particularly, to a device for forming a smooth cleavage surface on a cut surface while cutting the optical fiber.

Forming windows at a clad of an optical fiber is quite difficult, and depends on general machining, which results in long processing time.

The disclosed device is intended for quickly and accurately forming a window at a clad of an optical fiber.

According to aspects of the present disclosure, an optical fiber processing apparatus is as presented in the appended claims <NUM> to <NUM>.

Embodiments may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of embodiments to those skilled in the art. Like reference numerals in the drawings denote like elements. Furthermore, various elements and areas in the drawings are schematically drawn. Thus, the concept of the present disclosure is not limited by relative sizes or distances illustrated in the accompanying drawings.

While such terms as "first," "second," etc., may be used to describe various components, such components must not be limited to the above terms. The above terms are used only to distinguish one component from another. For example, a first component may be named as a second component, and in contrast, a second component may be named as a first component within the scope of the technical concept of the present disclosure.

The terms used in the present specification are merely used to describe exemplary embodiments, and are not intended to limit embodiments. In the present specification, it is to be understood that the terms such as "including," "having," and "comprising" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof disclosed in the specification, and are not intended to preclude the possibility that one or more other features, numbers, steps, actions, components, parts, or combinations thereof may exist or may be added.

Unless otherwise defined, every terms used herein including technical terms and scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present technical concept pertains. Further, the general terms defined by dictionaries shall be understood as having a meaning consistent with what such terms mean in the context of related technologies, and shall not be interpreted as excessively formal terms unless explicitly defined.

In the attached drawings, for example, according to a manufacturing technology and/or tolerance, modifications of the illustrated forms may be expected. Accordingly, embodiments of the present disclosure shall not be limited by specific forms illustrated in the drawings, and shall encompass modifications of forms caused by, for example, a manufacturing process. The term "and/or" has been used herein to include each mentioned component and all combinations of such components. The term "substrate" used in this specification may refer to a substrate itself, or a stacked structure including a substrate and a layer or a film, etc. formed on the substrate. Further, the term "surface of a substrate" used in this specification may refer to an exposed surface of the substrate itself, or an outer surface such as a layer, film, etc. formed on the substrate. Also, when a component is "on top of" or "on" another component, it should be construed that a component may be directly on and in contact with another component, or may be on another component in a noncontact manner.

<FIG> schematically illustrates an optical fiber processed by an optical fiber processing apparatus according to one or more embodiments, and <FIG> illustrates in detail the optical fiber of <FIG>.

As illustrated in <FIG> and <FIG>, the optical fiber <NUM> includes a core 10a through which light <NUM> proceeds and a clad 10b covering an outer circumference surface of the core 10a. A plurality of light output windows 10c through which the light proceeding inside the core 10a is output may be formed at the clad 10b in a longitudinal direction of the optical fiber.

The light <NUM> may be injected into the core 10a through one side area or a facet of the optical fiber <NUM>, and the light <NUM> injected into the core 10a may proceed along the core 10a to meet the light output window 11c at which time part of the light <NUM> may be output through the light output window 11c to the outside of the optical fiber <NUM>.

The light output windows 10c may be openings formed by partially removing the clad 10b covering the core 10a, and light output area through which part of the light proceeding along the core 10a may be output.

<FIG> is an actual photograph of the optical fiber <NUM> having the light output windows 10c.

As illustrated in <FIG>, the optical fiber <NUM> may function as a fibrous luminous body emitting light partially or entirely. Such optical fiber <NUM> may be used as a light source in various forms, such as, a dimming, lighting, or displaying system for vehicles, a light source for greenhouses, particularly for smart farms, a display device, a solar power generator, etc., and the usage of the optical fiber may be further extended.

<FIG> and <FIG> illustrate a structure of forming light output windows at an optical fiber according one or more embodiments.

As illustrated in <FIG> and <FIG>, the processing rods <NUM> may be arranged with a certain angular distance therebetween in a direction perpendicular to a proceeding direction of the optical fiber around the optical fiber <NUM> transferred in one direction. The optical fiber <NUM> may be transferred intermittently by certain spacing interval according to gradual formation of the light output windows 10c at the optical fiber <NUM>.

The processing rod <NUM> is arranged to be able to rotate with a high speed and move forward and backward, and at its end, a machining tip <NUM> for cutting the clad 10b of the optical fiber <NUM> is formed. The processing rod <NUM> forms through holes, i.e., the light output windows 10c at the clad 10b by high speed rotation.

The processing rods <NUM> may be arranged centering around the optical fiber <NUM> at its circumference with certain angular distance between each other, and after a first proceeding (approaching) to the optical fiber <NUM>, the machining tip 31a may contact with the clad 10b of the optical fiber <NUM>, and the processing of the light output window 10c may be performed on the clad 10b by a second proceeding. A distance of the first proceeding may correspond to a thickness value of the clad 10b, and accordingly, a distance of the second proceeding may be very short. The distance of the second processing may be properly adjusted according to a result of the processing on the clad 10b. Here, following the first proceeding, the second proceeding may be initiated after the machining tip 31a contacts with the clad 10b, and the distance may be calculated from a position of the machining tip 31a at a time point of contact. This is to form the light output windows 10c with an accurate thickness at the clad 10b regardless of mechanical errors inherent in arrangement of the processing rods <NUM>.

As an additional device to this end, when the machining tip 31a proceeds to contact with the clad 10b, a mechanical structure or an electric electron interrupter configured to mechanically, or electrically/electronically detect such contact may be provided to control a processing depth, thereby performing the processing of the light output window 10c within certain distance after the contact with the clad 10b. Alternatively, after the commencement of the processing of the light output window 10c on the clad 10b, by mechanically or electronically detecting the depth thereof, the light output window 10c at the clad 10b may be processed precisely. In the process of processing the light output window 10d through mechanical cutting by the processing rod <NUM>, the core inside the clad 10b may also be partially cut, and the depth of the part of the core cut by the processing rod <NUM> according to the processing depth control described above may be adjusted to a constant or desired depth.

<FIG> illustrates the technical concept of arranging the sensing tube <NUM> near the machining tip 31a of the fore-end of the processing rod <NUM> and stopping the processing when the sensing tube <NUM> is moved backward from the machining tip <NUM>.

As illustrated in A of <FIG>, the sensing tube <NUM> may be arranged so that the fore-end thereof is in line with the tip of the machining tip 31a in a normal state. In this state, when the processing rod <NUM> moves forward, the sensing tube <NUM> may also move.

As illustrated in B of <FIG>, the processing rod <NUM> moves forward to bring its tip into contact with the clad 10b of the optical fiber <NUM>, thereby initiating the processing of the light output window.

As illustrated in C of <FIG>, as the processing of the light output window proceeds, the sensing tube <NUM> arranged at the fore-end of the processing rod <NUM> may be pushed by the clad 10b and move backward of the processing rod <NUM>. At this time, when the distance by which the sensing tube <NUM> has moved backward reaches a preset value, the processing of the light output window 10c by the processing rod <NUM> may be suspended. The suspension of the processing may include suspension of moving backward and rotating of the processing rod <NUM>. Here, measurement of a preset value may be carried out by detecting a distance by which the sensing tube has moved backward with respect to the processing rod <NUM>, and accordingly, the sensing tube may be connected to an additional device for measuring the distance.

<FIG> illustrates arrangement of the light output windows formed around the core. As illustrated in <FIG> and <FIG>, as the processing rods <NUM> forming the light output window 10c may be arranged centering around the core 10a in a misaligned manner avoiding facing each other, two light output windows 10c arranged centering around a center point 10a' of the core 10a to face each other may not be on the same line.

In the process of forming the light output window 10c, processing the bottom surface of the light output window 10c according to mechanical processing, i.e., a cutting area of the surface of the core 10a exposed at the bottom of the light output window 10c to be smooth may be beneficial for suppression of light loss. To this end, by processing the optical fiber <NUM> at a low temperature or a temperature below zero, i.e., performing a cold cutting processing, a smooth cutting surface may be obtained. As for the low temperature processing, maintaining the processing space at a low temperature may be helpful, and further, by providing nitrogen gas in cooled condition locally, the optical fiber <NUM> may be quenched.

<FIG> and <FIG> are a perspective view and a projective diagram of a schematic exterior of an optical fiber processing apparatus according to one or more embodiments, respectively, and <FIG> is a partial enlarged view of a fiber proceeding tunnel through which an optical fiber passes.

The optical fiber processing apparatus illustrated in <FIG> and <FIG> includes the fiber proceeding tunnel <NUM> where formation of light output window 10c at the clad 10b of the optical fiber <NUM> passing therethrough is performed, and an optical fiber machining head <NUM> provided with a plurality of processing rod insertion holes <NUM> formed radially to be connected with the tunnel <NUM> on the circumference of the tunnel <NUM> in a direction perpendicular to the tunnel <NUM>.

On the circumference of the machining head <NUM>, the processing rod <NUM> having the machining tip 31a for processing the surface of the optical fiber (i.e., the clad) inside the proceeding tunnel through the processing rod insertion hole <NUM>, and an actuator <NUM> operating the processing rod are arranged. The actuator <NUM> may be a micro-drill capable of processing a very small hole.

The machining head <NUM> may include a head core <NUM> having the tunnel <NUM> through which the optical fiber <NUM> passes and a head body <NUM> supporting the head core <NUM>. However, according to another embodiment, the tunnel <NUM> may be formed on the head body <NUM> without the head core <NUM>. That is, the machining head <NUM> may include the head body <NUM> and the head core <NUM> constituting a single body.

In addition, a coolant passing hole <NUM> intersecting the processing rod insertion hole <NUM> may be formed at the head body <NUM>. The coolant passing hole <NUM> is for cooling the head body <NUM> and the optical fiber <NUM> and is optional. The refrigerant in gaseous or liquid state injected through a nipple <NUM> combined with the head body <NUM> may flow into the optical fiber proceeding tunnel <NUM> through the processing rod insertion hole <NUM>, and after flowing into the tunnel <NUM> through a gap formed by a spacer described below, it will be discharged.

The machining head may have an internal structure in which the processing rod insertion holes <NUM> arranged radially around the tunnel <NUM> through which the optical fiber passes are connected with the coolant passing hole <NUM> formed intersecting or perpendicular to the processing rod insertion hole.

Further, the actuators arranged radially around the tunnel <NUM> may not be placed on the same line based on the core 10a of the optical fiber <NUM> or the tunnel <NUM>. This is intended to suppress light loss or light output mal-uniform caused when the light output windows 10c formed at the optical fiber face each other. That is, in the embodiment of FIG. <NUM>, the seven actuators <NUM> are arranged at equal angles, and accordingly, all actuators <NUM> are formed in a misaligned manner with respect to each other, centering around the tunnel.

As illustrated in <FIG>, a cylindrical bushing <NUM> through which the optical fiber <NUM> passes may be provided at the head core <NUM> arranged at the head body <NUM>. A plurality of spacers <NUM> which are in contact with and support the optical fiber <NUM> may be formed inside the bushing <NUM>. The plurality of spacers <NUM> may be arranged with certain distance to reduce friction between a core cylinder <NUM> and the optical fiber <NUM> while supporting the optical fiber <NUM>. Due to such arrangement of the spacers <NUM>, a refrigerant inflow space for cold processing may be formed.

The spacers <NUM> may be placed with certain distance inside the bushing <NUM> forming a gear type spacing structure, and each spacer <NUM> may be extended in an extension direction or proceeding direction of the optical fiber <NUM>.

According to another embodiment, the spacers <NUM> formed inside the bushing <NUM> may be formed directly in the tunnel <NUM> formed at the head core <NUM>.

<FIG> and <FIG> illustrate installation state of an actuator <NUM> operating a processing rod <NUM>.

The actuator <NUM> may include a body of the machining head <NUM>, a stator frame <NUM> fixed to the outer circumference surface of the head body <NUM> according to the embodiment, a moving frame <NUM> reciprocating linearly with respect to the stator frame, and a motor <NUM> arranged at the moving frame and rotating the processing rod <NUM> with high speed. The relative location of the stator frame <NUM> may be fixed with respect to the machining head <NUM>, and according to the embodiment, the stator frame <NUM> may be fixed to the machining head <NUM>.

The movement of the moving frame <NUM> may cause a reciprocating motion for the processing rod insertion hole <NUM> of the head body <NUM> equipped with the processing rod <NUM>, and accordingly, the machining tip 31a of the processing rod <NUM> rotating with high speed may contact with the clad 10b of the optical fiber <NUM> and perform the processing of the light output window 10c at the clad 10b. The machining tip 31a may be formed of an artificial or natural diamond. According to the processing of the light output window 10c, when the clad 10c exposed at the bottom of the light output window 10c is also cut by a certain depth, such depth may be controlled by the cutting depth adjustment structure mentioned above.

Claim 1:
An optical fiber processing apparatus for forming a plurality of light output windows (10c) at a clad (10b) of an optical fiber (<NUM>) having a core (10a), the clad (10b) covering the core (10a), to fabricate a fibrous luminous body, the optical fiber processing apparatus comprising:
an optical fiber machining head (<NUM>) provided with an optical fiber proceeding tunnel (<NUM>) through which the optical fiber (<NUM>) passes, and a plurality of processing rod insertion holes (<NUM>) surrounding the tunnel (<NUM>) for optical fiber processing, and being formed in the circumference of the tunnel (<NUM>);
a plurality of processing rods (<NUM>), each having a machining tip (31a) to form the windows (10c) on the clad (10b) of the optical fiber (<NUM>) in the tunnel (<NUM>) through the processing rod insertion hole (<NUM>); and
a plurality of actuators (<NUM>), each configured to rotate each of the plurality of processing rods (<NUM>) with high speed and move each of the plurality of processing rods (<NUM>) forward and backward to and from the optical fiber (<NUM>), so that the machining tip (31a) cuts the clad (10b) of the optical fiber (<NUM>) to form the windows (10c).