JP2009294247A - Beam transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transform a pattern of light projected on an object with a simple configuration. <P>SOLUTION: The beam transformer 1 includes: a plurality of optical waveguides 131 to 133 which have an incident end face which receives light projected from a light source 11 and an emission end face which emits the received light; an objective optical system 15 which projects the light emitted from the emission end face onto a work W; and a positioning mechanism 14 which disposes at least one of the plurality of optical waveguides at a position at which the light from the light source 11 is received by changing the relative positions of at least one of the plurality of optical waveguides 131 to 133 and the light source 11. The intensity distribution of the light emitted at the emission end face of at least one of the optical waveguides disposed by the positioning mechanism 14 is different from the intensity distribution of the light emitted at the emission end face of at least one of the other optical waveguides. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a beam converter that changes a projection pattern of light onto an object.

  Conventionally, a beam converter that changes the spot diameter, light intensity distribution, and beam arrangement of light projected onto a workpiece (projection surface) is known. This beam converter can be mounted on a laser soldering device to enable soldering of multiple types of terminals, or incorporated into a laser marker to achieve marking with multiple types of sizes of dots. ing.

The spot diameter on the workpiece is changed by adjusting the position of the zoom lens. More specifically, the focal distance is suppressed by changing the distance between the lenses constituting the zoom lens to change the combined focal length and shifting the position of the entire lens group. Such a mechanical correction type zoom lens is described in, for example, Patent Document 1 below.
Japanese Patent Laid-Open No. 06-027381

  In order to make a zoom lens with no focal shift in the second group, it is necessary to move the second group simultaneously and correct the movement amount of the lens in the front group with a cam. However, such a mechanical correction type zoom lens causes a complicated mechanism, and it is difficult for the mechanical correction type to completely eliminate the focal plane displacement.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a beam converter that can change the projection pattern of light onto an object with a simple configuration.

  The beam converter according to the present invention includes a plurality of optical waveguides having an incident end face that receives light projected from the projection device and an exit end face that emits the received light, and the light emitted from the exit end face on the object. By changing the relative position of the projection objective optical system and at least one of the plurality of optical waveguides and the projection device, the at least one optical waveguide is disposed at a position where light from the projection device can be received. An intensity distribution of the emitted light at the exit end face of at least one optical waveguide disposed by the positioning mechanism, and an intensity distribution of the emitted light at the exit end face of at least one of the other optical waveguides. And different.

  According to such a beam converter, a plurality of optical waveguides having different intensity distributions of emitted light are prepared, and at least one of these optical waveguides is appropriately positioned at a position where light from the projection device can be received. Be placed. Therefore, the projection pattern of light onto the object can be changed without moving the objective optical system that projects light onto the object. That is, the projection pattern can be changed with a simple configuration.

  In the beam converter of the present invention, the incident end faces of the plurality of optical waveguides are each directed in the same direction, the exit end faces of the plurality of optical waveguides are respectively directed in the same direction, and the positioning mechanism is an array of the plurality of optical waveguides. It is preferable to change the position of at least one optical waveguide along the direction.

  In this case, since the incident end faces and the exit end faces of the plurality of optical waveguides face each other in the same direction, it is sufficient to change the position by the positioning mechanism along the arrangement direction of the optical waveguides. As a result, the configuration of the beam converter can be simplified.

  In the beam converter of the present invention, it is preferable that at least two of the plurality of optical waveguides simultaneously receive and emit light from the projection device.

  In this case, it is possible to project a beam array composed of a plurality of spots onto the object.

  In the beam converter of the present invention, it is preferable that at least one of the plurality of optical waveguides has a mode scramble mechanism.

  In this case, since the intensity distribution of the outgoing light at the outgoing end face changes between the optical waveguide having the mode scramble mechanism and the optical waveguide not having the mode scramble mechanism, the projection pattern of the light onto the object is changed by switching these optical waveguides. It becomes possible.

  In the beam converter of the present invention, it is preferable that at least two of the plurality of optical waveguides are integrated on the same substrate.

  In this case, since two or more optical waveguides of the plurality of optical waveguides are integrated, the configuration for moving the optical waveguide can be simplified.

  According to such a beam converter, a plurality of optical waveguides having different intensity distributions of emitted light are prepared, and at least one of these optical waveguides is appropriately disposed at a position where light from the projection device can be received. Therefore, the projection pattern of light onto the object can be changed with a simple configuration without incorporating a mechanism for moving the objective optical system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
FIG. 1 is a schematic diagram of a beam converter according to the first embodiment. FIG. 2 is an end view of the optical waveguide taken along line II-II in FIG. The beam converter 1 is a device capable of converting a spot diameter of light projected on a workpiece (projection surface, target) W. The beam converter 1 includes a light source 11, a condensing optical system 12, an optical waveguide 13, a positioning mechanism 14, and an objective optical system 15.

  The light source 11 is a projection device that emits light. The diameter of the emission end of the light source 11 is 40 μm, and its numerical aperture (NA) is 0.12.

  The condensing optical system 12 is an optical component that condenses the light L1 emitted from the light source 11 and emits the light L2 toward the incident end face of the optical waveguide described later. The focal length f of the condensing optical system 12 is 20 mm, and the effective numerical aperture (effective NA) is 0.2. The condensing optical system 12 is installed at a position 40 mm (= 2f) in front of the light source 11. By providing this condensing optical system 12, the amount of light incident on optical waveguides 131 to 133 described later can be secured. However, it is arbitrary whether such a condensing optical system is provided.

  The optical waveguide 13 is an optical component that receives the light L2 from the condensing optical system 12 and emits the light L3 toward an objective optical system 15 described later. The optical waveguide 13 is installed at a distance of 40 mm (= 2f) from the condensing optical system 12. The length of the optical waveguide 13 along the light transmission direction (the length in the left-right direction in FIG. 1) is 50 mm. The optical waveguide 13 includes three optical waveguides 131 to 133 having different core diameters and cladding diameters, and a base material 134 that fixes these optical waveguides. The core diameter and cladding diameter of the optical waveguide 131 are 200 μm and 220 μm, respectively, and the core diameter and cladding diameter of the optical waveguide 132 are 112 μm and 125 μm, respectively, and the core diameter and cladding diameter of the optical waveguide 133 are 72 μm and 80 μm, respectively. .

  The optical waveguides 131 to 133 are fixed so as to fit into three grooves each having a V-shaped cross section formed in parallel on the base material 134. As a result, these optical waveguides 131 to 133 are integrated. Has been. Each of the optical waveguides 131 to 133 has an incident end face that receives the light L2 and an outgoing end face that emits the light L3. Here, the incident end faces of the optical waveguides 131 to 133 are referred to as incident end faces 131a, 132a, and 133a, respectively, and the exit end faces are referred to as incident end faces 131b, 132b, and 133b, respectively. Each incident end face 131a, 132a, 133a faces the same direction (left direction in FIG. 1), and each exit end face 131b, 132b, 133b also faces the same direction (right direction in FIG. 1).

  The positioning mechanism 14 arranges the one optical waveguide at a position where the light from the light source 11 can be received by changing the relative position of one of the plurality of optical waveguides 131 to 133 with the light source 11. It is a control device. The positioning mechanism 14 changes the position of the optical waveguide 13 along the arrangement direction (vertical direction in FIG. 1) of the plurality of optical waveguides 131 to 133 based on a user input or execution of a predetermined program. For example, as shown in FIG. 1, the positioning mechanism 14 changes the position of the optical waveguide 13 so that the optical waveguide 133 receives light from the light source 11.

  The objective optical system 15 is an optical component that projects the light L3 emitted from the emission end face of one optical waveguide (the emission end face 133b of the optical waveguide 133 in the example of FIG. 1) onto the workpiece W (projected onto the workpiece W). Light is referred to as light L4). The optical parameters (focal length and effective NA) of the objective optical system 15 are the same as those of the condensing optical system 12. The objective optical system 15 is installed at a distance of 40 mm (= 2f) from the optical waveguide 13. The distance between the objective optical system 15 and the workpiece W is also 40 mm (= 2f), and this distance does not change.

  As described above, according to the first embodiment, since the core diameters of the plurality of optical waveguides 131 to 133 are different from each other, the intensity distributions of the emitted light at the emission end faces 131b, 132b, and 133b are also different from each other. Then, at least one of the optical waveguides 131 to 133 is disposed at a position where the light from the light source 11 can be received. Therefore, the projection pattern of the light L4 onto the workpiece W can be changed without moving the objective optical system 15 that projects the light onto the workpiece W. In particular, according to the first embodiment, the spot diameter of the light L4 can be changed.

  Further, according to the first embodiment, since the incident end faces 131a, 132a, 133a face the same direction and the exit end faces 131b, 132b, 133b also face the same direction, the positioning mechanism 14 makes the optical waveguide 13 the optical waveguide. It is possible to switch the optical waveguide by moving along the arrangement direction. As a result, the beam converter 1 can be configured more simply.

  In addition, according to the first embodiment, since the plurality of optical waveguides 131 to 133 are integrated by the base material 134, a mechanism for moving these optical waveguides 131 to 133 (for example, the optical waveguide 13 or positioning) The mechanism 14 and the like can be simplified.

  In the first embodiment, the core diameters of the optical waveguides 131 to 133 are 200 μm, 112 μm, and 72 μm. However, the core diameter of the optical waveguide used for the beam converter is not limited to these, and the optical waveguides having various core diameters. May be used. Therefore, for example, a beam converter having a spot diameter size ratio of 1:10 or a beam converter having a size ratio larger than that can be manufactured.

(Second Embodiment)
FIG. 3 is a schematic diagram of a beam converter according to the second embodiment. 4A is an end view taken along line IVA-IVA in FIG. 3, and FIG. 4B is an end view taken along line IVB-IVB in FIG. The beam converter 2 has an optical waveguide 16 instead of the optical waveguide 13 in the first embodiment. Since other configurations of the present embodiment are the same as those of the first embodiment, description thereof is omitted.

  The optical waveguide 16 is an optical component that receives the light L2 from the condensing optical system 12 and emits the light L3 toward the objective optical system 15. The optical waveguide 16 is installed at a distance of 40 mm (= 2f) from the condensing optical system 12. The distance between the optical waveguide 16 and the objective optical system 15 is also 40 mm (= 2f). The length of the optical waveguide 16 along the optical transmission direction (the length in the left-right direction in FIG. 3) is 50 mm. The optical waveguide 16 is configured to include one optical waveguide 161, four optical waveguides 162, and a base material 163 that fixes the optical waveguides 161 and 162.

  The core diameter and cladding diameter of the optical waveguide 161 are 200 μm and 220 μm, respectively, and the core diameter and cladding diameter of the optical waveguide 162 are 40 μm and 50 μm, respectively. A groove 164 having a V-shaped cross section and a groove 165 having a quadrangular cross section are formed in the base material 163 in parallel. The groove 165 is formed so that its width gradually increases as it moves from the condensing optical system 12 side to the objective optical system 15 side. The optical waveguide 161 is fixed so as to fit in the groove 164, and the optical waveguide 162 is fixed so as to fit in the groove 165. As a result, the optical waveguides 161 and 162 are integrated.

  The incident end face 161a of the optical waveguide 161 and the incident end face 162a of the optical waveguide 162 face the same direction (left direction in FIG. 3), and the outgoing end face 161b of the optical waveguide 161 and the outgoing end face 162b of the optical waveguide 162 are in the same direction (see FIG. (Right direction in 3). The four incident end faces 162a are arranged two above and below to form a substantially square as a whole (see FIG. 4A), but the four exit end faces 162b are arranged one on the top and one on the bottom, respectively. The entire cage forms a substantially triangular shape (see FIG. 4B). The four optical waveguides 162 simultaneously receive and emit light from the light source 11.

  As described above, according to the second embodiment, the plurality of optical waveguides 162 simultaneously receive and emit light from the light source 11, so that a beam array composed of a plurality of spots can be projected onto the workpiece W. In addition, the beam converter 2 has the same effect as the beam converter 1.

(Third embodiment)
FIG. 5 is a schematic diagram of a beam converter according to the third embodiment. FIG. 6 is an enlarged plan view of the optical waveguide shown in FIG. FIGS. 7A and 7B are graphs showing the intensity distribution of outgoing light on the outgoing end face of the optical waveguide. The beam converter 3 has an optical waveguide 17 instead of the optical waveguide 13 in the first embodiment. Since other configurations of the present embodiment are the same as those of the first embodiment, description thereof is omitted.

  The optical waveguide 17 is an optical component that receives the light L <b> 2 from the condensing optical system 12 and emits the light L <b> 3 toward the objective optical system 15. The optical waveguide 17 is installed at a distance of 40 mm (= 2f) from the condensing optical system 12. The distance between the optical waveguide 17 and the objective optical system 15 is also 40 mm (= 2f). The length of the optical waveguide 17 along the light transmission direction (the length in the left-right direction in FIG. 5) is 50 mm.

  The optical waveguide body 17 includes two optical waveguides 171 having a core diameter of 100 μm and a base material 172 that fixes the optical waveguide 171. These optical waveguides 171 are integrated by being fixed so as to fit into a V-shaped groove formed in parallel on the base material 172. The incident end face 171a of each optical waveguide 171 faces the same direction (left direction in FIG. 5), and each emission end face 171b also faces the same direction (right direction in FIG. 5).

One of the two optical waveguides 171 has a mode scramble mechanism 173 including a light scatterer 173a. Note that the mode scramble mechanism may be configured by a method other than the application of the light scatterer. For example, the core glass is impregnated with hydrogen molecules by holding an optical fiber having a core made of GeO ₂ —SiO ₂ glass or a quartz-based planar optical waveguide in a high-pressure hydrogen atmosphere. Then, a mode scramble mechanism in which a refractive index change of about 1 × 10 ⁻³ exists in a patch shape can be generated by irradiating the portion with ultraviolet rays in the vicinity of 248 nm. When the optical waveguide is composed of an optical fiber having a diameter of about several tens to several hundreds of micrometers, a lateral pressure is applied to the optical fiber using a hemisphere or cylinder having a diameter of about several hundreds of micrometers. A mode scramble mechanism can be configured.

Depending on the presence / absence of the mode scramble mechanism 173, the intensity distribution of the output light on the emission end face 171b changes as shown in FIG. FIG. 7A is a graph for the optical waveguide 171 that does not include the mode scramble mechanism 173, and FIG. 7B is a graph for the optical waveguide 171 that includes the mode scramble mechanism 173. The vertical and horizontal axes of the graphs of FIGS. 7A and 7B are the output light intensity (W / cm ² ) and the position in the arrangement direction, respectively. In the graph, the core diameter of the optical waveguide 171 is φ. When the mode scramble mechanism 173 is not provided, the intensity distribution is substantially bell-shaped with the center of the core as the highest point. On the other hand, when the mode scramble mechanism 173 is provided, a high strength is obtained over substantially the entire core. Maintained.

  As described above, according to the third embodiment, the intensity distribution of outgoing light at the outgoing end face 171b varies between the optical waveguide 171 having the mode scramble mechanism 173 and the optical waveguide 171 having no mode scramble mechanism 173. Therefore, it is possible to change the projection pattern of light onto the object.

  The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be modified in various ways as described below without departing from the scope of the invention.

  In each of the above embodiments, the plurality of optical waveguides are integrated by being fixed to the base material. However, such integration may not be performed. In that case, the positioning device individually controls the plurality of optical waveguides, thereby arranging at least one optical waveguide at a position where light from the projection device can be received.

  In each of the above embodiments, the beam converter has a function of changing the spot diameter and beam arrangement of the light emitted from the light source. However, the spot diameter and beam arrangement of the reflected light may be changed. In this case, an optical component (for example, a reflector) that generates reflected light corresponds to the projection device.

It is a schematic diagram of the beam converter which concerns on 1st Embodiment. FIG. 2 is an end view of the optical waveguide body taken along line II-II in FIG. 1. It is a schematic diagram of the beam converter which concerns on 2nd Embodiment. FIG. 4A is an end view taken along line IVA-IVA in FIG. 3, and FIG. 4B is an end view taken along line IVB-IVB in FIG. It is a schematic diagram of the beam converter which concerns on 3rd Embodiment. FIG. 6 is an enlarged plan view of the optical waveguide shown in FIG. 5. It is a graph which shows intensity distribution of the emitted light in the output end surface of an optical waveguide, (a) shows the case where a mode scramble mechanism is not provided, and (b) shows the case where a mode scramble mechanism is provided, respectively.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2, 3 ... Beam converter, 11 ... Light source (projection apparatus), 12 ... Condensing optical system, 13, 16, 17 ... Optical waveguide, 14 ... Positioning mechanism, 15 ... Objective optical system, 131-133 161-162, 171 ... optical waveguide, 131a, 132a, 133a, 161a, 162a, 171a ... incident end face, 131b, 132b, 133b, 161b, 162b, 171b ... outgoing end face, 173 ... mode scramble mechanism, W ... work (target) object).

Claims (5)

A plurality of optical waveguides having an incident end face for receiving the light projected from the projection device and an outgoing end face for emitting the received light;
An objective optical system that projects the light emitted from the exit end face onto an object;
A positioning mechanism that arranges the at least one optical waveguide at a position capable of receiving light from the projection device by changing a relative position between at least one of the plurality of optical waveguides and the projection device; ,
With
The intensity distribution of the emitted light at the emission end face of the at least one optical waveguide arranged by the positioning mechanism is different from the intensity distribution of the emitted light at the emission end face of at least one of the other optical waveguides,
Beam converter. The incident end faces of the plurality of optical waveguides are each directed in the same direction,
The exit end faces of the plurality of optical waveguides are each directed in the same direction,
The positioning mechanism changes a position of the at least one optical waveguide along an arrangement direction of the plurality of optical waveguides;
The beam converter according to claim 1. At least two of the plurality of optical waveguides simultaneously receive and emit light from the projection device,
The beam converter according to claim 1 or 2. At least one of the plurality of optical waveguides has a mode scramble mechanism,
The beam converter as described in any one of Claims 1-3. At least two of the plurality of optical waveguides are integrated on the same substrate,
The beam converter as described in any one of Claims 1-4.

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