JP2002062460A - Beam-condensing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a beam-condensing unit capable of condensing light beams, which have a large aspect ratio and radiant angle, efficiently into a minute spot. SOLUTION: The unit is equipped with a light guiding duct 14 for reducing the radiant angle of light from a light source 12 and a light condensing means 16 for condensing the light passed through the light guiding duct 14. In addition, the unit is equipped with a condensing duct that condenses light beams while guiding the light beams emitted from the light source 12, and with a light guiding duct that reduces the radiant angle of light by taking in at least a part of the light beams guided by the condensing duct.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing device, and more particularly to a condensing device for condensing light having a large aspect ratio and a large radiation angle (divergence angle) emitted from an array type semiconductor laser device or the like into a minute spot. About.

[0002]

2. Description of the Related Art Conventionally, as a laser device used in laser processing, optical communication, optical measurement, or the like, or an excitation light source used in such a laser device, a plurality of laser diodes (hereinafter, referred to as LD) are provided in a light emitting region. An array type semiconductor laser such as a laser diode bar (hereinafter, referred to as an LD bar) in which are arranged is used.

Normally, an LD bar has a light emitting area of about 10 mm in the horizontal direction and about 1 μm in the vertical direction (thickness direction). Light emitted from the LD arranged in this light emitting area is about 10 ° in the horizontal direction and about 10 ° in the vertical direction. It has a radiation angle of about 30 ° (all of which show full angles; the same applies hereinafter). Therefore, the spot of light emitted from the light emitting region of the LD bar has an elliptical shape with a large aspect ratio (aspect ratio). In order to use such light for laser processing or the like, it is necessary to condense the light to a minute spot having a similar aspect ratio.

In general, when converging non-parallel light having a predetermined radiation angle to a minute spot, it is conceivable to reduce the radiation angle of the light using a collimating lens and then to condense the light using a condensing lens. Can be However, in order to reduce the emission angle of light with a large aspect ratio, the focal length is long,
A collimating lens with a large curvature must be used. In addition, since the light source and the collimating lens need to be arranged at a predetermined distance, a lens having a sufficient size is necessary for the spread of light emitted from the light source.

For example, an LD having a width of 150 μm and a thickness of several μm
When it is attempted to reduce the horizontal radiation angle of light having a radiation angle of about 10 ° in the horizontal direction and about 30 ° in the vertical direction emitted from the lens to about 3 °, the focal length is considered even when there is no aberration. A collimating lens having a diameter of about 3 mm and an effective diameter of about 2 mm is required. Such a lens is expensive because it must be formed of a special glass material on both surfaces of the aspheric surface. Also,
Due to its large diameter, it cannot be used for a light source such as an LD bar in which LDs are arranged at a minute pitch of about 0.5 mm.

Accordingly, a light source, such as an LD bar, in which a plurality of light emitting elements are arranged at a small pitch and the emitted light has a large aspect ratio, is condensed by an optical system using a collimating lens and a condensing lens. Is difficult to do.

[0007] Japanese Patent Application Laid-Open No. 2000-19362 discloses an LD.
As shown in FIGS. 18 and 19, as a device for condensing the light emitted from the bar, a cylindrical lens 54 for reducing the vertical radiation angle of the light emitted from the LD bar 52, and the cylindrical lens 54 An optical coupling device 50 including a light converging device 56 that converges transmitted light is disclosed.

The light converging device 56 includes an optical waveguide 58 for guiding light emitted from the LD 52a provided on the LD bar 52.
And a coupling portion 60 formed in a triangular shape for condensing the light guided by the optical waveguide 58. The number of the optical waveguides 58 is equal to the number of the LDs 52a provided in the LD bar 52, and each optical waveguide 58 is provided with the LD 52a.
The arrangement interval is narrowed in the traveling direction of the light emitted from the light source and the light is coupled to one side of the coupling portion 60.

The end face of the optical waveguide 58 facing the cylindrical lens 54 is an incident face 58a on which the light emitted from the LD 52a is incident, and the arrangement pitch is LD.
52a are formed so as to be at equal intervals. And
The light converging device 56 includes a light emitting region of the LD bar 52 and an incident surface 58a.
Are arranged in parallel.

In such an optical coupling device 50, the LD
The light emitted from the bar 52 is a cylindrical lens 54
After the radiation angle in the vertical direction is reduced by the above, the light is incident on the incident surface 58a of the optical waveguide 58. This light is guided to the coupling section 60 via each waveguide 58 and integrated. The light integrated by the coupling unit 60 is totally reflected by the side wall of the coupling unit 60 and condensed while being confined in the coupling unit 60 and propagated. The collected light is emitted from the vertex 60a of the coupling section 60.

[0011]

However, in the above-described apparatus, each time the light guided to the coupling portion 52a is totally reflected by the side wall of the coupling portion 60, the angle of incidence on the side wall decreases. Therefore, when the light travels to some extent in the coupling section 60, the incident angle of the light on the side wall of the coupling section 60 cannot maintain the critical angle which is a condition of total reflection, and the light cannot be reflected on the side wall. For this reason, the ratio at which light can be collected by the coupling unit 60 is limited to about 1/3 to 1/5.
If a lens for reducing the horizontal radiation angle of the light emitted from the LD 52a is used to solve this problem, the number of components of the device increases, and the alignment of each component becomes difficult. Costs increase. In addition, due to the misalignment of each component, the reliability in use is reduced.

In the above-described apparatus, since the coupling portion 60 for condensing light is thin, a cylindrical lens 54 is provided to efficiently enter the light into the coupling portion 60, and thereby the vertical lens is provided. It is necessary to reduce the radiation angle in the direction in advance. This increases the cost of manufacturing and adjusting the device, and reduces the reliability in use.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has a simple configuration and is capable of efficiently condensing light having a large aspect ratio and a large radiation angle into a minute spot. It is intended to provide a device.

[0014]

In order to achieve the above object, the present invention has the following contents. The invention of claim 1 is
The light condensing device includes a light guiding unit that reduces a radiation angle while guiding light emitted from a light source, and a light collecting unit that collects light passing through the light guiding unit. According to the present invention, after the radiation angle of light emitted from the light source is reduced by the light guide unit, and then the light is condensed by the condensing unit, the light emitted from the light source can be condensed into a minute spot. Will be possible.

According to a second aspect of the present invention, the light guide section is located in an incident surface on which the light emitted from the light source is incident, and in a traveling direction of the light incident from the incident surface, and the light incident from the incident surface is provided. An emission surface from which the light is emitted, and a reflection surface that connects the incidence surface and the emission surface, and reflects the light incident from the incidence surface and propagates the light toward the emission surface, thereby reducing the emission angle of the light. 1 is a light collecting device. According to the present invention, since the light from the light source can be guided by making the incident surface of the light guide unit and the light source face each other, the positioning of each component can be performed more easily than a device using a conventional collimating lens or cylindrical lens. The tolerance of accuracy is increased, and alignment is facilitated. Therefore, it is possible to reduce the manufacturing and adjustment costs of the device and to improve the reliability in use.

According to a third aspect of the present invention, the light source includes a plurality of light emitters, and a plurality of light guides are provided to individually guide light emitted from each of the plurality of light emitters. The light collecting device according to claim 1, wherein the light unit collectively collects light passing through the plurality of light guide units. According to the present invention, light emitted from each light emitter is incident only on the corresponding light guide duct, and is not incident on an adjacent duct, so that loss of light emitted from the light emitter can be reduced. Will be possible.

According to a fourth aspect of the present invention, the plurality of light guides are arranged such that the combined aspect of the light emitted from the light emitting surfaces of the plurality of light guides is smaller than the aspect ratio of the light emitted from the light source. 4. The light-collecting device according to claim 3, wherein the arrangement of the entrance surface and the exit surface is different. According to the present invention, since the aspect ratio of the light emitted from the emission surface of the light guide section is reduced, it is possible to condense the light emitted from the light source to a minute spot having the same aspect ratio.

According to a fifth aspect of the present invention, the light condensing portion is located on an incident surface on which the light passing through the light guide portion is incident, and in a traveling direction of the light incident on the incident surface, and the light incident on the incident surface is provided. 5. An emission surface from which light is emitted, and a reflection surface for connecting the incident surface and the emission surface, and reflecting light incident from the incident surface and condensing while reflecting the light in the direction of the emission surface. A light-collecting device according to any one of the preceding claims. According to the present invention, since the light passing through the light guide section can be guided to the light collecting section by making the light exit surface of the light guide section and the light incident face of the light collecting section face each other, the light guide section and the light collecting section The tolerance of the positioning accuracy becomes large, and the alignment becomes easy. Therefore, it is possible to reduce the manufacturing and adjustment costs of the device and to improve the reliability in use.

According to a sixth aspect of the present invention, there is provided a light condensing portion for condensing light emitted from a light source while guiding the light, and taking in at least a part of the light guided by the light condensing portion to acquire the light. And a light guide for reducing the radiation angle.
According to the present invention, the light emitted from the light source is guided by the condensing portion, and at least a part of the light guided by the condensing portion is taken into the light guiding portion to guide the light. As a result, it is possible to collect light while reducing the radiation angle of light.

According to a seventh aspect of the present invention, there is provided the light-collecting device according to any one of the first to sixth aspects, wherein the light guide portion and the light-collecting portion are integrally formed. According to the present invention, since the light guide section and the condensing section are integrally formed, the condensing efficiency can be improved, and alignment of each component is not required. Therefore, it is possible to reduce the manufacturing and adjustment costs of the device and to improve the reliability in use.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a light collecting device according to the present invention. The light collecting device 10 is used for collecting light having a high radiation angle and an aspect ratio emitted from an LD bar or the like. As shown in FIG.
Includes a light guide duct 14 that is a light guide that reduces the radiation angle of light emitted from the light source 12, and a convex lens 16 that is a light collector that collects light passing through the light guide duct 14.

The light guide duct 14 is made of an optical material that is optically transparent to the wavelength of light to be condensed, such as glass such as quartz glass and phosphate glass, plastic, and optical crystals. As shown in FIG. 2, the light guide duct 14 has an incident surface 14a on which the condensed light is incident, and an exit surface 14b facing the incident surface 14a and emitting the light incident from the incident surface 14a. And a pair of upper and lower surfaces 14c and side surfaces 14d connecting the entrance surface 14a and the exit surface 14b.

The incident surface 14a has a rectangular shape whose width and thickness are larger than the light emitting area of the light source 12. The incident surface 14a may be formed with a curved surface in order to increase the efficiency of light incidence from the light source 12. Further, the exit surface 14b has a rectangular shape larger than the entrance surface 14a in the direction in which the radiation angle of light is reduced (in the present embodiment, the thickness direction and the width direction). The entrance surface 14a and the exit surface 14b are connected by the upper and lower surfaces 14c and the side surfaces 14d such that the thickness and the width continuously increase at a predetermined spread angle.

The entrance surface 14a and the exit surface 1 of the light guide duct 14
Reference numeral 4b denotes a broken surface or a polished surface through which light can enter and exit, and an anti-reflection film is formed as necessary. The portions of the light guide duct 14 other than the entrance surface 14a and the exit surface 14b are removed with a low-refractive-index polymer in order to remove the influence of the outside world such as dust in the air, if necessary, and to protect each surface. Covered.

The length L of the light guide duct 14 and the width W of the exit surface are set as follows. As shown in FIG. 3, the light guide duct 14 having a divergence angle Φ and a width D1 of the incident surface has
It is assumed that light having a radiation angle β enters at a position yin from the center line C of the light guide duct 14. In this case, the angle of the light propagating in the light guide duct 14 with respect to the side surface 14d decreases by Φ each time the light is reflected by the side surface 14d. The angle formed is within Φ.

Here, it is assumed that the allowable range of the radiation angle of the light emitted from the light guide duct 14 is 2Φ. In this case, the angle between the light emitted from the light guide duct 14 and the center line C of the light guide duct 14 is Φ or less. Then, if the angle formed with the center line C at an angle of β / 2 and the angle formed with the center line C at the n-th reflection is smaller than Φ, the light incident at a radiation angle β or less is reflected at the n-th reflection. Has a radiation angle smaller than 2Φ. Such n is obtained by Equation 1.
In Equation 1, Integer Part [A] represents the largest integer not exceeding A.

(Equation 1)

The coordinates x [n] in the length direction and the coordinates y in the width direction of the light guide duct 14 at the position where the n-th reflection is performed.
[n] is obtained by Expression 2 and Expression 3, respectively.

(Equation 2)

(Equation 3)

FIGS. 4 and 5 show that β = 10 ° and D1 = 250.
7 is a graph showing the relationship between φ, the length L of the light guide duct 14, and the width W of the exit surface when μm and yin = 75 μm. FIG.
5 and FIG. 5, for example, when Φ = 1.1 °, the required duct length is about 99 mm, and the width of the exit surface is about 2.15 mm. However, the light from the actual light source is refracted by Snell's law when it enters the entrance surface and exits from the exit surface, so that some correction is required. Also, the exit surface 14
The thickness of b is obtained in the same manner.

When such a light guide duct is formed of glass, the light guide duct can be manufactured by cutting out a glass plate polished to a predetermined thickness with a carbon dioxide laser, press-molding, or the like. When the light guide duct is made of plastic, it can be manufactured by injection molding or the like.

At a position facing the light exit surface 14b of the light guide duct 14 at a predetermined distance, a convex lens 16
Is provided. As the light collecting means, a light collecting duct, a wedge lens, or the like can be used instead of or together with the convex lens 16. As shown in FIG. 1, the light is incident on the light collecting device 10 by bringing the light incident surface 14 a of the light guide duct 14 and the light emitting area of the light source 12 close to each other.

Next, the operation of the light collecting device 10 will be described. Incident surface 14a of light guide duct 14 and light source 12
When the light-emitting regions are brought close to each other, the light emitted from the light source 12 is introduced into the light guide duct 14 from the incident surface 14a. This light is reflected by the upper and lower surfaces 14c and the side surfaces 14d of the light guide duct 14, and propagates in the direction of the emission surface 14b. At this time,
The entrance surface 14a and the exit surface 14b are separated from each other by upper and lower surfaces 14c and side surfaces 14d such that the thickness and the width are increased at a predetermined spread angle.
, The light that travels in the light guide duct 14 is reduced in radiation angle each time it is reflected by the upper and lower surfaces 14c and 14d. Light emitted from the emission surface 14b of the light collection duct 14 is collected by the convex lens 16 into a minute spot.

As described above, according to the condensing device 10 of the present invention, after the radiation angle of light is reduced by the light guide duct 14,
Since the light is condensed by the convex lens 16, it is possible to condense the light emitted from the light source 12 to a minute spot. In addition, the configuration is simpler than that of a conventional light collecting device using a large number of optical parts, and the connection between the light source 12 and the convex lens 16 is performed by the light guide duct 14, so that the alignment of each component becomes easy.

Next, another embodiment of the light-collecting device according to the present invention will be described. In the following description, the same parts as those described above are denoted by the same reference numerals, and detailed description thereof will be omitted. 6 and 7 show a second embodiment of the light collecting device according to the present invention. The light collecting device 20 is used for collecting light emitted from a light source having a plurality of light-emitting elements arranged like an LD bar. The light collecting device 20 includes a duct array 22 in which a plurality of the light guide ducts 14 described above are arranged corresponding to a plurality of light emitters, and a convex lens 16 that collectively collects light passing through the duct array 22. I have.

In the duct array 22, the light guide duct 1
As shown in FIGS. 6 to 8, the light-receiving elements 4 are linearly arranged in the horizontal direction such that the light-entering surface 14 a faces each light-emitting body. Thus, the light emitted from each light emitting body is incident only on the incident surface 14a of the opposing light guide duct 14, and is not incident on the incident surface 14a of the adjacent light guide duct 14. Also, the exit surface 14b of the light guide duct 14
Are arranged so as to be vertically stacked in five stages.
Thereby, the light is converted from the horizontal alignment to the vertical alignment. As shown in FIG. 9, such a duct array 22 can also be integrated using an optical medium 24 such as a resin on the exit surface 14b side.

In such a light condensing device 20, the light emitted from each light emitting body is introduced into the light guide duct 14 from the opposing incident surface 14a. At this time, the light emitted from each light emitter enters only the opposing light guide duct 14 and does not enter the adjacent light guide duct, so that the loss of light emitted from the light emitter is reduced. be able to. This light is propagated in the light guide duct 14 to reduce the radiation angle. Then, the light emitted from the emission surface 14b of the duct 14 is focused on the minute spot by the convex lens 16.

As described above, according to the light condensing device 20 of the present embodiment, the loss of light emitted from the light emitter can be reduced, so that light can be condensed efficiently.
In addition, since the light can be converted from the horizontal arrangement to the vertical arrangement, the aspect ratio of the light passing through the light guide duct 14 can be reduced. Therefore, it is possible to condense the light emitted from the LD bar to a minute spot having the same vertical and horizontal size. Furthermore, since the configuration is simple and the connection between the light source 12 and the convex lens 16 is performed by the light guide duct 14, the alignment of the components is facilitated.

Next, a third embodiment of the light collecting device of the present invention will be described. FIG. 10 shows a third example of the light-collecting device according to the present invention.
1 shows an embodiment. This light-collecting device is also used for collecting light emitted from a light source in which a plurality of light-emitting bodies are arranged, as in the second embodiment.

The light collecting device 30 includes a plurality of light guide ducts 32 provided corresponding to the respective light emitters, and a light collection duct 34 for integrally collecting light passing through the light guide ducts 32. Have. The light guide duct 32 and the light collection duct 34
It is integrally formed of a material that is optically transparent to the wavelength of light to be condensed, such as glass such as quartz glass and phosphate glass, plastic, and optical crystals.

The light guide duct 32 is made of a thin plate and formed in a square shape. One surface in the thickness direction including the short side of the quadrangle is a light incident surface 32a, and a surface facing the incident surface 32a is a light exit surface 32b. The incident surface 32a is
It has a rectangular shape whose width is larger than that of the light emitters arranged in the light source. A convex surface may be formed on the incident surface 32a in order to increase the efficiency of incidence of light from the luminous body. Outgoing surface 32b
Has a rectangular shape larger than the incident surface in the direction in which the light emission angle is reduced (in the width direction in the present embodiment).

The entrance surface 32a and the exit surface 32b are connected at their side surfaces so that the width continuously increases at a predetermined spread angle in the light traveling direction. The light is propagated while being reflected by the side surface while the radiation angle in the horizontal direction is reduced, and is emitted from the emission surface 32b.

The light guide ducts 32 are linearly arranged in the horizontal direction such that the light incident surface 32a faces each light emitter. Thus, the light emitted from one light emitter is incident only on the incident surface 32a of the opposing light guide duct 32, and is not incident on the incident surface of the adjacent light guide duct.

The light collection duct 34 is formed in a thin plate isosceles triangle shape. The surface in the thickness direction including the base of the isosceles triangle is the light incident surface 34a, and the surface including the apex facing the base is the light output surface 34b. This condensing duct 3
4 is connected to the light exit surface 32a of the light guide duct 32, and the light emitted from the luminous body is
The light is incident on the light collection duct 34 through the second light source 2. This light guide may be connected such that all the light guide ducts 32 face the top of the light collection duct 34 as shown in FIG. This makes it possible to reduce the width of the light emitted from the light source. Further, as shown in FIG. 11, the light guides may be connected so as to be substantially parallel to each other.

The entrance surface 34a and the exit surface 3 of the condenser duct 32
The light incident from the incident surface 34a travels while being reflected by the upper and lower surfaces, and is emitted while being collected by being reflected by the side surface 34c. The light is propagated in the direction of the surface 34b.

The light condensing device 30 can be manufactured, for example, by cutting a glass plate polished to a predetermined thickness with a carbon dioxide gas laser, or by press molding. When the light guide duct is made of plastic, it can be integrally manufactured by injection molding or the like.

In such a light condensing device 30, the light emitted from each illuminant of the light source is incident on the opposing incident surface 32a.
The light is further introduced into the light guide duct 32. At this time, the light emitted from each light emitter enters only the incident surface 32a of the opposing light guide duct 32 and does not enter the incident surface 32a of the adjacent light guide duct 32. Loss of emitted light can be reduced.

The light is propagated in the direction of the emission surface 32b while being reflected on the upper and lower surfaces and side surfaces of the light guide duct 32. At this time, since the width is formed so as to increase from the incident surface 32a of the light guide duct 32 toward the emission surface 32b, the horizontal radiation angle of light propagating in the light guide duct 32 is reduced.

The light emitted from the light exit surface 32b of the light guide duct 32 enters the light collection duct 34 from the light entrance surface 34a of the light collection duct 34. The light travels while being repeatedly reflected on the upper and lower surfaces of the light collecting duct 34, is reflected on the side surface 34b, and is collected while being propagated in the direction of the light emitting surface 34b. This condensed light is finally emitted from the exit surface 3 of the condensing duct 34.
4b.

As described above, according to the light condensing device 30 of the present invention, the light emitted from each illuminant enters only the light guide duct 32 provided opposite to the illuminant, and the adjacent light guide Since the light does not enter the duct, the light guide duct 32
Can be reduced. Also,
The light guide duct can reduce the horizontal radiation angle of the light, so that the light can be condensed into a minute spot by the thin plate-shaped condensing duct. Further, since the light guide duct 32 for guiding the light from the light source and the light collecting duct 34 for collecting the light emitted from the light guide duct 32 are integrally formed,
The light collection efficiency can be improved, and alignment of each component is not required.

Next, a fourth embodiment of the light collecting device of the present invention will be described. This condensing device is used for condensing light having a high radiation angle and aspect ratio emitted from an LD bar or the like. As shown in FIGS. 12 to 14, the light collecting device 40 includes a light collecting duct 42 for collecting light emitted from a light source, and at least a part of the light collected by the light collecting duct 42. And a light guide duct 14 for reducing the radiation angle.

The light collecting duct 42 is made of an optical material that is optically transparent to the wavelength of light to be collected, similarly to the light guiding duct 14. The condensing duct 42 has an incident surface 42a on which light to be condensed is incident, and an exit surface 42b which faces the incident surface 42a and emits light incident from the incident surface 42a.
And an upper surface 42c, a lower surface 42d, and a pair of side surfaces 42e connecting the incident surface 42a and the output surface 42b.

The incident surface 42a has a rectangular shape whose width and thickness are larger than the light emitting area of the light source. This incident surface 42a
May have a curved surface in order to increase the efficiency of incidence of light from the light source. In addition, the exit surface 42b is formed on the entrance surface 42 in the light converging direction (in the present embodiment, the thickness direction and the width direction).
It has a rectangular shape smaller than a. This incident surface 42a
And the emission surface 42b are formed by the upper and lower surfaces 42c and 42d and the side surface 4 so that the thickness and the width are continuously reduced at a predetermined narrowing angle.
2e. As a result, the light incident from the incident surface 42a is separated between the upper and lower surfaces 42c and 42d and the side surface 42
By being reflected between the light emitting elements e, the light is condensed and propagated in the direction of the emission surface.

The light guide duct 14 is provided on the upper surface 42c of the light collection duct 42 in an optically integrated state along the center line thereof. Thereby, at least a part of the light propagating through the light collection duct 42 can be guided to the light guide duct 14.

The light-collecting duct 42 and the light-guiding duct 1
It is preferable that the refractive indices 4 are set to the same level. When the refractive index of the light guide duct 14 becomes higher than the refractive index of the light collecting duct 42, the angle of incidence of the light taken into the light guiding duct 14 increases due to refraction at the boundary surface between the light collecting duct 42 and the light guiding duct 14. However, the light guide duct 14 makes it difficult to reduce the radiation angle. On the other hand, when the refractive index of the light collecting duct 42 increases, the light incident on the light collecting duct 42
And the light is hardly taken into the light guide duct 14. However, if the refractive index of the light collecting duct 42 is set to be slightly higher than the refractive index of the light guiding duct 14, refraction at the interface between the light collecting duct 42 and the light guiding duct 14 causes
The incident angle of the light taken into the light guide duct 14 is reduced, and the radiation angle is easily reduced by the light guide duct 14.

The light incident surface 14 a of the light guide duct 14 is usually formed so as to form the same plane as the light incident surface 42 a of the light collecting duct 42. In the light-collecting device 40, light emitted from the light source is usually incident from the incident surface 42a of the light-collecting duct 42, but at least a part of the light emitted from the light source is incident on the incident surface 14a of the light-guiding duct 14. May be made to enter. The light exit surface 14b of the light guide duct 14 forms the same plane as the light exit surface 42b of the light collection duct 42. Usually, these light entrance surfaces 14b and 42b are integrated to form the light exit surface of the light collection device. . However, when there is a difference between the refractive indices of the light collecting duct 42 and the light guiding duct 14, the light is guided at a portion having a high refractive index and is easily emitted.

Such a light collecting device 40 may be integrally formed by polishing or press molding or the like, or may be formed by polishing or press molding or the like.
4 can be formed by bonding with an adhesive or the like. In such a light collecting device 40, the light collecting duct 42
And the entrance surfaces 42a, 14a and the exit surface 4 of the light guide duct 14.
Normally, 2b and 14b are fracturing surfaces or polished surfaces through which light can enter and exit, and an anti-reflection film is formed as necessary. Further, the incident surfaces 14a, 42a and the exit surfaces 14b, 42
The portion excluding b is covered with a low-refractive-index polymer for the purpose of removing external influences such as dust in the air as necessary and protecting each surface. Generally, the light is incident on the light-collecting device 40 by bringing the light-incident surface 42a of the light-collecting duct 42 close to the light-emitting area of the light source.

Next, the operation of the light collecting device 40 will be described. When the light incident area 42a of the light collecting duct 42 and the light emitting area of the light source are brought close to each other, light emitted from the light source is introduced into the light collecting duct 42 from the light incident surface 42a. This light is reflected on the upper and lower surfaces 42c and 42d and the side surface 42e of the light collecting duct 42 and propagates in the direction of the light exit surface 42b. At this time, the upper and lower surfaces 42c and 42d and the side surface 4 are so formed that the incident surface 42a and the exit surface 42b are reduced in thickness and width at a predetermined narrowing angle.
Since the light is connected at 2e, the light traveling in the light collection duct 42 is propagated in the direction of the emission surface 42b while being collected.

At least a part of this light is collected by the condenser duct 42.
The light guide duct 14 is guided into the light guide duct 14 from the boundary surface. The light guided to the light guide duct 14 is reflected by the upper and lower surfaces 14c and the side surfaces 14d of the light guide duct 14, and is output from the light exit surface 14b.
Propagation in the direction. At this time, the entrance surface 14a and the exit surface 1
4b is connected to the upper and lower surfaces 14c and the side surfaces 14d so that the thickness and the width are enlarged at a predetermined spread angle.
The radiation angle of the light traveling in the light guide duct 14 is reduced each time it is reflected on the upper and lower surfaces 14c and the side surfaces 14d.

As described above, the light condensing device 40 according to the present embodiment
Incident on the light collecting duct 42 is condensed by propagating through the light collecting duct 42, and is also transmitted through the light guiding duct 14, so that the radiation angle is reduced. This light is finally transmitted to the light-collecting duct 42 and the light-exiting surfaces 42 a and 14
a.

According to the light collecting device 40 of the present embodiment, at least a part of the light propagating in the light collecting duct 42 is taken into the light guiding duct 14 and guided to increase the light quantity with a small radiation angle. Therefore, it is possible to collect light while reducing the emission angle of light as a whole.

In the light collecting device 40 described above, a cylindrical surface or an inclined surface may be formed on the side surface 42e of the light collecting duct. This changes the direction of light that is less likely to be guided to the light guide duct 14 and allows more light to be directed to the light guide duct 14.
Can be led to.

Next, a fifth embodiment of the light collector of the present invention will be described with reference to FIGS. As in the fourth embodiment, the light collecting device 45 includes a light collecting duct 42 for collecting light emitted from a light source,
And a light guide duct 14 for taking in at least a part of the light condensed by 2 and reducing its radiation angle. In the light collecting device 45, the light guide duct 14 is provided in a state of being optically integrated with the side surface 42e of the light collecting duct 42. Thereby, at least a part of the light propagating through the light collection duct 42 can be guided to the light guide duct 14.

According to the light collecting device of the present embodiment, at least a part of the light propagating in the light collecting duct 42 is taken into the light guiding duct 14 and guided to increase the light quantity with a small radiation angle. It is possible to collect light while reducing the emission angle of light as a whole.

The present invention is not limited to the above-described embodiment, and can be appropriately changed. For example, in the above-described embodiment, the light guide ducts 14 and 32, the light collection duct 3
Although the plates 4 and 42 are formed in a plate shape, they may be formed in a conical shape or an elliptical cone shape.

[0064]

The present invention will be specifically described below with reference to examples. (Example 1) Light was condensed using the light condensing device 10 shown in FIG. The light source 12 has a width of 150 μm and a thickness of several μm.
And the emission angle of the emitted light is about 1 in the width direction.
A semiconductor laser having 0 ° and a thickness direction of about 30 ° was used. As the light guide duct 14, the width of the incident surface 14a is 250 μm.
m, thickness 100 μm, total length 70 mm, divergence angle 1.5 ° in the width direction of the light guide duct 14, divergence angle 2.1 in the thickness direction
mrad, width of the exit surface 14b 2.08 mm, thickness 250
A quartz glass duct having a cylindrical lens surface having a radius of curvature of about 60 μm in the first axis direction (thickness direction) of the incident surface 14a was used. Convex lens 1
As No. 6, a product made of LaFS9 having a focal length of 1.5 mm and an effective diameter of 2.5 mm was used. As a result, the convex lens 16
Thus, light having a spot diameter of 85 μm in the width direction and 7 μm in the thickness direction could be obtained.

Example 2 Light was condensed using the light condensing device 20 shown in FIGS. Light source 12 has width 15
LD having a light emitting surface of 0 μm and a thickness of several μm is 0.5 mm
20 LD bars arranged in the width direction at a pitch were used. The emission angle of light emitted from each LD is about 10 ° in the width direction and about 30 ° in the thickness direction. As the light guide duct 14, the width of the incident surface 14a is 250 μm, the thickness is 100 μm,
Total length 100 mm, divergence angle in the width direction 1.0 °, divergence angle in the thickness direction 1.5 mrad, width 1.99 of emission surface 14b
A duct made of quartz glass having a thickness of 250 μm and a cylindrical lens surface having a radius of curvature of about 60 μm in the first axis direction (thickness direction) of the incident surface 14a was used.

The light incident surface 14a of the light guide duct 14 is
0.5m to face the laser diode of the bar
Twenty light guide ducts 14 are arranged at m pitches, and five light guide ducts 14 are arranged so as to overlap on the exit surface 14b side, thereby forming a duct array 22. LaFS 9 as the convex lens 16
And a focal length of 10 mm and an effective diameter of 15 mm. As a result, 660 μm in the width direction from the condenser lens 16,
Light having a spot diameter of 240 μm in the thickness direction could be obtained.

(Embodiment 3) Light collecting device 3 shown in FIG.
Light was collected using 0. The same LD bar as in Example 2 was used as a light source. As the light collecting device 30, one in which one light collecting duct 34 and 20 light guide ducts 32 were integrally formed of quartz glass was used. In the light collecting device 30, the thickness is changed from the light guiding duct 32 to the light collecting duct 3.
It is constant at 250 μm over the range of 4.

The light guide duct 32 has a width of 250 μm on the incident surface 32a, a total length of 20 mm, and a width of 300 mm on the exit surface 32b.
μm and a divergence angle of 5 mrad were used. Also,
As the light collecting duct 34, the width of the incident surface 34a is 6.0 m.
m, the width of the emission surface 34b was 500 μm, the total length was 30 mm, and the reduction angle was 10 °. The center lines of the light guide ducts 32 all face the exit of the light collection duct 34. 0.5 mm so that the incident surface 32a of the light guide duct 32 of the light collecting device 30 faces the laser diode of the LD bar.
Arranged at pitch. At this time, the exit surface 3 of the light collection duct 34
The light collection efficiency of the light emitted from 4b was improved to about 70%.

(Embodiment 4) Light collecting device 3 shown in FIG.
Light was collected using 0. The same LD bar as in Example 2 was used as a light source. As the light collecting device 30, a light collecting duct 34 and 20 light guide ducts 32 integrally formed of quartz glass were used. This light collecting device 3
At 0, the thickness is constant at 250 μm from the light guide duct 32 to the light collection duct 34. As the light guide duct 32, a light entrance surface 32a having a width of 250 μm, a total length of 20 mm, a light exit surface 32b having a width of 400 μm, and a divergence angle of 7.6 mrad was used. Further, as the light collecting duct 34, the width of the incident surface 34a is 8 mm, the width of the output surface 34b is
The total length was 40 mm and the reduction angle was 10 °. The light incident surface 32a of the light guide duct 32 of the light collecting device 30 is
0.5μ to face the laser diode of the bar
They were arranged at an m pitch. At this time, the light collection efficiency of the light emitted from the emission surface 34b of the light collection duct 34 was about 65%.

Example 5 Light was condensed using the light condensing device 40 shown in FIGS. A quartz glass duct having a width of 11 mm and a thickness of 0.2 mm of the incident surface 42a and a width of 2 mm, a thickness of 0.1 mm and a total length of 100 mm of the exit surface 42b was manufactured by polishing as the light collecting duct 42. Further, as the light guide duct 14, the width of the incident surface 14a is 1 mm and the thickness is 0.1 mm.
A quartz glass duct having a length of 1 mm, a width of the exit surface 14b of 2 mm, a thickness of 0.2 mm, and a total length of 100 mm was manufactured by polishing. The light guide duct 14 was arranged along the center line of the upper surface 42c of the light collection duct 42, and both were bonded with an adhesive having a refractive index substantially equal to that of quartz glass. Each duct 1
4, 42 incident surfaces 14a, 42a and exit surfaces 14b, 4
2b was coated with an anti-reflection film to obtain a light collecting device shown in FIGS.

As a light source, width 150 μm, thickness several μm,
The emission angle of the emitted light is about 10 ° in the width direction and about 3 in the thickness direction.
An LD bar in which 20 LDs at 0 ° are arranged at a pitch of 0.5 mm was used. When the light incident surface 42a of the condenser duct 42 is brought close to the light emitting surface of the LD bar, about 85%
Was obtained. As a control, when light was collected using a light collection duct without the light guide duct 14, a light collection efficiency of about 80% was obtained. Further, the divergence angle of the beam obtained from the light condensing device 40 could be reduced by about several percent by providing the light guide duct 14.

Example 6 Light was condensed by using the light condensing device 45 shown in FIGS. The condensing duct 42 has a width of 11 mm and a thickness of 0.2 mm of the incident surface 42a, a width of 0.05 mm or less, a thickness of 0.1 mm and a total length of 1 of the exit surface 42b.
A 00 mm quartz glass duct was manufactured by polishing. Further, as the light guide duct 14, the width of the incident surface 14a is set to 0.1.
A quartz glass duct having a thickness of 2 mm, a thickness of 0.1 mm, a width of the exit surface 14b of 2 mm, a thickness of 0.2 mm, and a total length of 100 mm was manufactured by polishing.

The light guide duct 14 was disposed on the side surface 42e of the light collecting duct 42, and both were bonded with an adhesive having a refractive index substantially equal to that of quartz glass. Each duct 14, 42
The entrance surfaces 14a and 42a and the exit surfaces 14b and 42b were coated with an anti-reflection film to obtain a light condensing device 45 shown in FIGS. As the light source, the same L as in Example 5 was used.
D bar was used. A light collecting duct 4 is provided on the light emitting surface of this LD bar.
When the second incident surface 42a was brought close to the device, a light collection efficiency of about 83% was obtained. The divergence angle of the beam obtained from the light condensing device 45 was almost the same as that of the fifth embodiment.

[0074]

As is apparent from the above description, according to the present invention, the light emitted from the light source is condensed after the emission angle of the light emitted from the light source is reduced, so that the light emitted from the light source can be reduced. It becomes possible to condense on a spot. In addition, since the connection between the light source and the condensing means is performed by the light guide duct, the tolerance of the positioning accuracy of each component is increased,
Alignment is easy. Further, according to the present invention, the light emitted from the light source is guided by the light collecting unit, and at least a part of the light guided by the light collecting unit is taken into the light guiding unit to guide the light. Thus, it becomes possible to collect light while reducing the radiation angle of light as a whole.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a first embodiment of a light collecting device according to the present invention.

FIG. 2 is a perspective view showing a light guide duct of the light collecting device according to the present invention.

FIG. 3 is a diagram for explaining the relationship between the length of the light guide duct and the width of the exit surface, the divergence angle Φ of the duct, and the width of the entrance surface.

FIG. 4 is a graph for explaining the relationship between the spread angle of the light guide duct and the length of the light guide duct.

FIG. 5 is a graph for explaining a relationship between a spread angle of a light guide duct and a width of an emission surface of the light guide duct.

FIG. 6 is a plan view schematically showing a light collecting device according to a second embodiment of the present invention.

FIG. 7 is a side view schematically showing a second embodiment of the light collecting device according to the present invention.

FIG. 8 is a perspective view showing a duct array used in the light collecting device according to the present invention.

FIG. 9 is a plan view showing another example of the light collecting device according to the second embodiment of the present invention.

FIG. 10 is a plan view schematically showing a light collecting device according to a third embodiment of the present invention.

FIG. 11 is a plan view showing another example of the light collecting device according to the third embodiment of the present invention.

FIG. 12 is a perspective view schematically showing a fourth embodiment of the light collecting device according to the present invention.

FIG. 13 is a cross sectional view schematically showing a fourth embodiment of the light collecting device according to the present invention.

FIG. 14 is a longitudinal sectional view schematically showing a light collecting device according to a fourth embodiment of the present invention.

FIG. 15 is a perspective view schematically showing a fifth embodiment of the light collecting device according to the present invention.

FIG. 16 is a cross sectional view schematically showing a fifth embodiment of the light collecting device according to the present invention.

FIG. 17 is a longitudinal sectional view schematically showing a fifth embodiment of the light collecting device according to the present invention.

FIG. 18 is a plan view showing an example of a conventional optical coupling device.

FIG. 19 is a side view showing an example of a conventional optical coupling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Condenser 12 Light source 14 Light guide duct 16 Convex lens 20 Concentrator 30 Concentrator 32 Light guide duct 34 Concentrator duct 40 Concentrator 42 Concentrator duct 45 Concentrator

Claims (7)

[Claims] 1. A light-collecting device comprising: a light-guiding unit that reduces a radiation angle while guiding light emitted from a light source; and a light-collecting unit that collects light passing through the light-guiding unit. 2. The light guide unit according to claim 1, wherein the light guide unit is positioned in an incident surface on which the light emitted from the light source is incident, and in a traveling direction of the light incident from the incident surface. An emitting surface for emitting light, a reflecting surface connecting the incident surface and the emitting surface, and reflecting the light incident from the incident surface and propagating in the direction of the emitting surface to reduce a radiation angle of the light. The light collecting device according to claim 1. 3. The light source includes a plurality of light emitters.
A plurality of the light guides are provided so as to individually guide light emitted from each of the plurality of light emitters, and the light condensing unit collectively collects light passing through the plurality of light guides. The light collecting device according to claim 1 or 2, wherein 4. An incident surface of the plurality of light guides such that an aspect ratio of light obtained by combining light emitted from the plurality of light guides with respect to an aspect ratio of light emitted from the light source is reduced. The light-collecting device according to claim 3, wherein the arrangement of the light-emitting surface and the light-emitting surface are different. 5. The light-collecting unit is located in an incident surface on which light passing through the light guide unit is incident, and in a traveling direction of light incident from the incident surface, and receives light incident from the incident surface. An outgoing surface to be emitted, and a reflecting surface that connects the incident surface and the outgoing surface, and reflects light incident from the incident surface and collects light while propagating in the direction of the outgoing surface. 5. The light-collecting device according to claim 4. 6. A light-collecting unit that guides and condenses light emitted from a light source, and reduces at least a part of light guided by the light-condensing unit to reduce a radiation angle of the light. A light collecting device including a light guide unit. 7. The light-collecting device according to claim 1, wherein the light-guiding part and the light-collecting part are formed integrally.