JPH10278341A - Light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light source in which the number of components is decreased, positional shift is eliminated at the time of assembling work and variation in the characteristics due to the environmental temperature is suppressed by setting the center line of each lens supporting part substantially perpendicularly to the pitch direction of beams outputted from a plurality of collimator lenses. SOLUTION: Center line of the cross-sectional arc of a lens supporting part 1b, 1b is set substantially perpendicular to the direction of subscanning pitch of two beams outputted from collimator lenses 3, 3. At the time of assembly, the collimator lens 3 is arranged concentrically to the axis of a semiconductor laser 2, 2 on the lens supporting part 1b, 1b. A gap being formed between the adhesive surface 1c of the lens supporting part 1b and the outer circumferential surface of the collimator, lens 3 is filled with a UV-curing adhesive. When UV-rays are irradiated after adjusting the position finely, the entire adhesive is hardened uniformly and positional shift of the collimator lens 3 due to uneven hardening or unhardened part can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device using a semiconductor laser used in a digital copying machine, a laser printer, and the like.

[0002]

2. Description of the Related Art A light source device using a semiconductor laser is required to have, as optical characteristics, the directionality (optical axis characteristic) of laser light emitted from the light source device and the parallelism (collimation characteristic) of a light beam. For this reason, the light source device usually adjusts the relative position of the light emitting point of the semiconductor laser and the collimator lens in three directions (x-axis, y-axis, z-axis), and the position accuracy is on the order of microns or less. Is required. Therefore, in the light source device having the semiconductor laser and the collimator lens, the light source device must have a structure capable of adjusting the position in the three axial directions and fixing at the adjusted position.

When the collimator lens is fixed with an adhesive, the adhesive shrinks at the time of curing, so that it is ideal to minimize the adverse effect on the optical characteristics due to the shrinkage. In particular, since the required accuracy in the z-axis direction (optical axis direction) of the light source device is high, it is desirable to configure the light source device so that the contraction direction does not occur in the z-axis direction. Therefore, the adhesive layer is usually set in a direction substantially parallel to the optical axis (a direction parallel to the z-axis), and also in other axis directions (x-axis and y-axis directions) to facilitate adjustment. In addition, it is desirable that the contraction direction be as small as possible in one of the x-axis and y-axis directions.

Further, in a digital copying machine or a laser printer, a light source device for simultaneously scanning a plurality of rows for the purpose of speeding up printing and switching of pixel density, needless to say, a plurality of semiconductor lasers and a plurality of collimator lenses are used. The laser beam is generated, and the beam pitch accuracy of the direction (the optical axis characteristic pitch accuracy in the row direction, that is, the y-axis direction) is required. Therefore, it is desirable to configure the adhesive layer so that the shrinkage does not occur in the y-axis direction.

[0005] Here, first, a conventional technique regarding a light source device for generating one laser beam will be described. FIG. 3 shows an example of a conventional light source device (JP-A-5-88061).
This light source device was previously filed by the present applicant, and as shown, a semiconductor laser 13 for irradiating a laser beam is press-fitted and fixed in a stepped hole 12 provided in a base 11 as a holding member. ing. A fitting hole 16 is formed in the flange 15 attached to the base 11 by the two screws 14, 14 at a position facing the stepped hole 12. An inlet portion 16a having a diameter about 0.1 mm larger than the hole 16 is formed.

The fitting hole 16 has a fitting hole 16
A cylindrical lens holder 17 having a clearance of about 1 to 0.03 mm is fitted therein.
A collimator lens 18 for converting the laser light into a parallel light beam is held in 7.

On the other hand, a guide pin 21 protruding from the end surface of the base 11 is fitted into a positioning hole 20 formed in the printed circuit board 19, and the tip of the guide pin 21 is melted by heat to form an imaginary line. By crushing as shown
The base 11 and the printed circuit board 19 are fixed. The lead wire 22 of the semiconductor laser 13 is passed through a lead wire insertion hole formed in the printed board 19, and is soldered to a conductive pattern for wiring on the back side of the printed board 19.

After the position of the flange 15 is adjusted in the x-axis and y-axis directions so that the emission point of the semiconductor laser 13 coincides with the optical axis of the collimator lens 18, the flange 15 is fixed to the base 11 by screws 14.

The flange 15 attached to the base 11
Is formed with a notch 23 connected to the entrance 16a, and the lens holder 17 is moved so that the light source position of the semiconductor laser 13 matches the focal position of the collimator lens 18.
After the position is adjusted in the axial direction, an adhesive is injected from the cutout portion 23 and allowed to penetrate into the inside, so that the lens holder 1
7 is fixed to the flange 15.

The aperture forming member 24 is a shielding cap for taking out and shaping a parallel light beam near the center of the light beam transmitted through the collimator lens 18, and includes an aperture 24 a formed of a light beam selecting hole, and a flange 15. And a projection 24b for fitting to the projection 24b.
b is fitted into the notch 23 of the flange 15,
The aperture forming member 24 is fixed to the flange 15.

When the light source device is mounted on a main body of a digital copying machine or a laser printer, a plane 15a perpendicular to the optical axis of the flange 15 is used as a reference plane, and adjustment of optical characteristics is also performed with reference to this plane 15a.

Next, the prior art in the case of a plurality (two) will be described. FIG. 4 shows a light source device described in JP-A-7-181410 and JP-A-7-181412 filed by the present applicant earlier. The light source device of FIG. 4 will be described. Stepped holes similar to those of the base 11 of FIG. 3 are provided in the two bases 31, and two semiconductor lasers 33, 33 for irradiating laser light are press-fitted and fixed. Base 31
Is attached to the flange 35 by four screws 34. Fitting holes 36, 36 are formed in the flange 35 at positions corresponding to the semiconductor lasers 33, 33, respectively.
The fitting holes 36,36
Tubular lens holders 37, 37 having a clearance of about 0.03 mm are fitted therein, and collimator lenses 38, 38 for converting a laser beam into a parallel light beam are held in the lens holder 37.

The bases 31 are provided with a semiconductor laser 3.
Collimator lens 3 whose light emitting points of 3 and 33 face each other
After adjusting the positions in the x-axis and y-axis directions so as to coincide with the optical axes 8 and 38, they are fixed to the flange 35 by two screws 34 and 34, respectively.

Notches 36a are formed in the fitting holes 36, 36 of the flange 35, and the lens holders 37, 37 are so arranged that the emission points of the semiconductor lasers 33, 33 coincide with the focal positions of the collimator lenses 38, 38. Are adjusted in the z-axis direction, and then an adhesive is injected from the notch portion 36a and penetrates into the inside thereof, whereby the lens holder 37,
37 is fixed to the flange 35.

The aperture forming member 39 is a member for taking out and shaping a parallel light beam near the center of the collimator lenses 38, 38. The aperture forming members 39 are provided with apertures 39a, 39a formed of light beam selecting holes. Apertures 39a, 39a near the center of lenses 38, 38
Are set to coincide with each optical axis. Aperture 3
The parallel light beams emitted from 9a and 39a are combined into almost coaxial beams 41 and 41 by a beam combining prism 40, and then guided to a scanning optical system provided for image writing provided thereafter. At this time, the two beams 41, 4
The beam pitch of 1 is such that the angle of the output optical axis is fine so that the pitch in the sub-scanning direction on the image writing surface (the column direction in the image writing, that is, the row pitch direction in the case of simultaneous writing of two rows) is a desired interval. Adjusted. This method corresponds to the above-described position adjustment of the base 31 in the y-axis direction.

[0016]

However, the above-mentioned conventional light source device has the following problems. As a first problem, the properties of the adhesive after curing are equivalent to those of general resins. Resins usually have a higher coefficient of linear expansion than metals and have a greater shrinkage with respect to temperature changes. In the light source device of FIG. 4 in order to enhance the reliability against temperature change, even if a metal material having a small linear expansion coefficient is selected for the base 31 and the flange 35, the two collimator lenses 38 and 3 are not required.
Since a resin adhesive layer is formed between the collimator lenses 8, the change in pitch between the collimator lenses 38 and 38 is large when the temperature changes, and as a result, the two beams 41 emitted from the beam combining prism 40 , 41 vary. Eventually, the pitch in the sub-scanning direction on the image writing surface changes, which leads to deterioration in image quality.

The second problem is that the adjustment unit in the x-axis and y-axis directions (the adjustment unit for the optical axis characteristics) and the adjustment unit in the z-axis direction (the collimation characteristics, that is, the adjustment unit for the focal direction) have different structures. Therefore, the number of components of the light source device is large, and the cost of the product is high.

As a third problem, the laser light of the semiconductor laser 13 used in the light source device has a certain spread, and not all the laser light is incident on the collimator lens 18. The semiconductor laser has a legal standard from the viewpoint of safety for the human body, and it is desirable that the laser light does not leak outside the optical axis direction. This is true not only during use but also during adjustment in the manufacturing process.
The base 11 and the base 11 need to be made of a material that does not leak laser light to the outside.

On the other hand, as the adhesive used for fixing the lens holder 17, an ultraviolet curable adhesive which can be arbitrarily cured in a short time is advantageous for shortening the production tact time and has excellent reliability. . However, when the base 11 and the flange 15 are made of a material through which ultraviolet rays do not pass as in the light source device of the prior application, even if the ultraviolet rays are irradiated through the gap filled with the ultraviolet curable adhesive, the filled adhesive can be used. Irradiation cannot be performed evenly on the whole, and uneven curing and uncured portions occur. For this reason, distortion due to curing shrinkage acts unequally, causing problems such as displacement of the lens holder 17 and cracking of constituent members.

A material that does not transmit laser light such as infrared light or red light emitted from the laser light source 13 does not transmit ultraviolet light having a shorter wavelength. For this reason, if only ultraviolet rays are to be transmitted, a special filter must be added or a special coating must be applied to the flange 15 itself, resulting in a problem that the cost is significantly increased. Therefore, an ultraviolet-curable adhesive could not be used as an adhesive for fixing the collimator lens 18.

As a fourth problem, since the adhesive layer is present on the entire peripheral surface of the lens holder 17, that is, in all directions of the x-axis and the y-axis, the curing shrinkage direction of the adhesive in the x-axis and the y-axis directions is different. It is not fixed, and the positional accuracy in the x-axis and y-axis directions varies. To ensure positional accuracy after bonding, it is necessary to offset the initial position in anticipation of a certain amount of shrinkage. However, if the shrinkage direction of the adhesive layer is not constant, it is difficult to give an offset, Accuracy (optical axis characteristics) may be reduced.

A fifth problem is that a method is adopted in which the screw 14 is tightened after the adjustment in the x-axis and y-axis directions to fix the flange 15 to the base 11. Due to the engagement of the flange 15 with the screw seat on the end face, a displacement may occur in the x-axis and y-axis directions, and the accuracy of the laser directionality (optical axis characteristics) may be reduced.

As a sixth problem, the adhesive is cut into the notch 23
In this case, distortion occurs in the optical axis direction (z-axis direction) due to partial solidification shrinkage in the inflow process and variations in the way of inflow, resulting in variations in positional accuracy.

The present invention has been made in order to solve the above-mentioned problems. The present invention has a small number of components, has no risk of displacement during assembling, and uses a light-curing adhesive for the collimator lens. An object of the present invention is to provide an inexpensive and high-precision light source device that can be used and adhered, has little characteristic change due to temperature environment, and is inexpensive.

[0025]

According to a first aspect of the present invention, there is provided a light source device comprising: a base having a plurality of fitting holes penetrating on the front and back; A plurality of semiconductor lasers respectively fitted to the plurality of collimator lenses, a plurality of collimator lenses adhered and fixed respectively coaxially to the optical axis of the semiconductor laser to a lens support on the base surface side of the fitting hole, and In a light source device having a plurality of apertures for shaping outgoing laser light and a beam synthesizing unit for synthesizing the laser light substantially coaxially, a center line of each of the lens support portions is formed from the plurality of collimator lenses. It is characterized by being located in a direction substantially orthogonal to the direction of the emitted beam pitch.

In this configuration, the center line of each lens support for bonding a plurality of collimator lenses is set substantially perpendicular to the beam pitch direction emitted from the plurality of collimator lenses. The effect of curing shrinkage of the agent does not occur in the beam pitch direction, and the effect of adhesive expansion and contraction due to temperature change does not occur in the beam pitch direction, so that the beam pitch accuracy is excellent and the accuracy can be stably maintained. A light source device can be provided.

In the light source device according to the second aspect,
In the light source device described above, each of the plurality of collimator lenses is directly fixed to a lens support unit integrally formed on the base using a light-curable adhesive.

In this configuration, since the collimator lens is directly fixed to the lens support unit formed integrally with the base, the number of parts of the light source device can be reduced, and the light source device can be provided at low cost. Can be. further,
Since there is no intervening member such as a holder between the collimator lens and the lens supporting portion, it can be fixed with high accuracy without being affected by manufacturing errors of the intervening member. In addition, since the collimator lens is configured to be directly fixed to the lens support part that is integrally molded with the base, tightening parts such as screws are eliminated, eliminating misalignment of parts at the time of tightening, and providing a highly accurate light source device. can do.

In the light source device according to the third aspect,
3. The light source device according to any one of 1 to 2, wherein the lens support portion is configured to be line-symmetric with respect to a line orthogonal to the beam pitch direction.

In this configuration, distortion due to curing shrinkage in the beam pitch direction is canceled out and curing shrinkage is limited to a direction orthogonal to the beam pitch direction. Therefore, the directionality of curing shrinkage is further improved, and higher precision is achieved. Position can be adjusted.

In the light source device according to the fourth aspect, the first aspect is as follows.
In the light source device according to any one of the above (1) to (3), the lens support portion is formed in an arc-shaped cross section slightly larger in diameter than the outer circumference of the collimator lens.

In this configuration, since the lens supporting portion is formed in a circular cross section having a diameter slightly larger than the outer circumferential circle of the collimator lens, the lens supporting portion and the collimator lens are concentrically arranged, so that the collimator lens and the lens are arranged concentrically. The adhesive layer formed between the support portions has a uniform thickness. For this reason, the entire surface of the adhesive layer is solidified uniformly, so that curing unevenness is eliminated, and displacement of the collimator lens is prevented.

In the light source device according to the fifth aspect, the first aspect
In the light source device according to any one of (1) to (3), the lens support portion is formed in an arc shape having a larger radius of curvature than a radius of curvature of an outer peripheral circle of the collimator lens. .

In this configuration, since the lens supporting portion is formed in an arc-shaped cross section having a radius of curvature substantially larger than the radius of curvature of the outer peripheral circle of the collimator lens by the thickness of the adhesive layer, the lens supporting portion and the collimator lens are arranged concentrically. Thereby, the adhesive layer formed between the collimator lens and the lens supporting portion has a desired adhesive layer thickness and a uniform thickness. For this reason, the entire surface of the adhesive layer is solidified uniformly, so that curing unevenness is eliminated, and displacement of the collimator lens is prevented.

According to the light source device of the sixth aspect, in the fourth aspect,
6. The light source device according to any one of 1 to 5, wherein a cross section of the lens support portion is an arc of a semicircle or less.

In this configuration, the adhesive layer only covers less than half of the outer circumference of the collimator lens, and the curing shrinkage of the adhesive has directionality. Therefore, the initial position of the collimator lens is offset in anticipation of the amount of shrinkage of the adhesive. And the positional accuracy after curing can be improved. Further, a curing light beam can be irradiated from the opening side of the lens support toward the side surface of the collimator lens, and curing unevenness is further eliminated.

According to the light source device of the seventh aspect, in the first aspect,
7. The light source device according to any one of items 6 to 6, wherein a non-adhesion portion is formed between the collimator lens and the base in an optical axis direction.

In this configuration, the non-adhesion portion formed between the base wall surface and the collimator lens allows the protruding adhesive to directly adhere to the base wall surface even if a large amount of adhesive is filled. The hardening and shrinking force in the optical axis direction (z-axis direction) caused by the adhesive adhered to the base wall surface and hardened does not act on the collimator lens. For this reason, the positional accuracy in the optical axis direction can be improved.

[0039]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a light source device of the present invention, and FIG. 2 is a schematic front view including a lens supporting portion when the collimator lens is bonded. The base 1 has two fitting holes 1a, 1a. Semiconductor lasers 2 and 2 for irradiating laser light are press-fitted and fixed to the back surfaces of the fitting holes 1a and 1a. The base 1 is located at the front surface of the fitting holes 1a, 1a to directly adhere and fix the collimator lenses 3, 3, and has a diameter slightly larger than the outer circumference of the collimator lenses 3, 3 (for example, about 0.2 mm). 2.) The lens support portions 1b, 1b having an arc-shaped cross section are integrally formed concentrically with the optical axes of the semiconductor lasers 2, 2. The lens support 1
b may be formed in an arc-shaped cross section having a radius of curvature substantially larger than the radius of curvature of the outer peripheral circle of the collimator lens 3 by the thickness of the adhesive layer.

The direction of the optical axis (the z-axis direction) of the lens support portion 1b is such that even if the adhesive is excessively filled, it does not adhere to other portions. It is longer than the lens thickness in the z-axis direction). When viewed from the front, the shape of the lens support portion 1b is an arc-shaped cross section that is not more than a semicircle. The shape when viewed from the front is desirably an arc of a symmetrical cross section that is opened by about 60 degrees as shown in FIG. 2 for ease of position adjustment and bonding work. Further, the center lines C, C of the cross-section arcs of the lens support portions 1b, 1b are set substantially perpendicular to the sub-scanning pitch direction (y-axis direction) of the two beams emitted from the collimator lenses 3, 3. ing.

The collimator lens 3 is made of a material that can transmit ultraviolet rays. Plastic lenses and glass lenses are conceivable as lenses of such a material,
A glass lens having excellent optical characteristics is more desirable. When the collimator lens 3 is assembled, as shown in FIG.
It is gripped by chucks 7, 7 whose positions can be adjusted in three axes (x-axis, y-axis, z-axis), and arranged on the lens support portions 1b, 1b concentrically with the respective optical axes of the semiconductor lasers 2, 2. .

After filling the gap formed between the bonding surface 1c of the lens support 1b and the outer peripheral surface of the collimator lens 3 with the ultraviolet curing adhesive 6, the optical characteristics are measured by an inspection device (not shown). The position of the collimator lens 3a is finely adjusted during the inspection, and when the position at which the desired optical characteristic is obtained is determined, the chucks 7, 7 are fixed and, as shown in FIG. UV light L is irradiated from the UV light irradiator 8. The ultraviolet light L radiated from the ultraviolet irradiator 8 is transmitted through the collimator lens 3 and radiated to the adhesive 6 to uniformly cure the entire adhesive 6.

This curing of the adhesive is performed for each of the two collimator lenses 3, 3. Therefore, the thickness between the bonding surfaces 1c, 1c of the lens support portions 1b, 1b and the collimator lenses 3, 3 is uniform and symmetrical with the gap dimension (about 0.2 mm), and the thickness direction is sub-scanning. Adhesive layers 6, 6 substantially perpendicular to the pitch direction (y-axis direction) are formed, and the collimator lenses 3, 3 are maintained on the lens support portions 1b, 1b by the adhesive layers 6, 6 while maintaining predetermined optical characteristics. Fixed. That is, the lens support portions 1b, 1b
Are axisymmetric with respect to a line perpendicular to the beam pitch direction.

In particular, as shown in FIG.
In the case where b is formed in a left-right symmetrical cross-sectional arc shape opened by about 60 degrees, the support of the collimator lens 3 by the chucks 7 and 7 can be performed easily and reliably, and the ultraviolet light L radiated from the ultraviolet irradiator 8 can be used. Can be applied to the entire surface of the bonding surface 1c, and the curing of the adhesive can be performed uniformly and completely. For this reason, a completely solidified and uniform adhesive layer is obtained, and it is possible to eliminate the occurrence of unevenness in curing and displacement of the collimator lens 3 due to uncured portions.

The distortion due to the curing shrinkage of the adhesive is y
Since they occur symmetrically in the axial direction, they are canceled out and x
It is limited to only one axial direction. This distortion in the x-axis direction can be slightly offset in anticipation of the amount of curing shrinkage. Therefore, the directionality (optical axis characteristics) of the beams emitted from the two collimator lenses is very excellent in the y-axis direction. Naturally, the accuracy of the two beam pitches (interval accuracy in the y-axis direction; (Scanning pitch accuracy)
Also excellent.

Further, the change in the lens interval in the y-axis direction at the environmental temperature is caused by the fact that the adhesive layers are each symmetrical (symmetric in the y-axis direction), so that the expansion and contraction of the adhesive layers are offset in the y-axis direction. Is not changed, and is limited only to the x-axis direction.
Therefore, also in this respect, the accuracy of the two beam pitches is excellent.

The aperture forming member 4 is a member for taking out and shaping a parallel light beam near the center of the collimator lenses 3 and 3, and is an aperture 4 formed of a light beam selecting hole.
a, 4b are provided, and the respective collimator lenses 3, 3
Are set so that the apertures 4a and 4b coincide with the respective optical axes. The parallel light beams emitted from the apertures 4a, 4a are combined into a substantially coaxial beam by a beam combining prism 5, which is a beam combining means, and then sent to a scanning optical system (not shown) provided for image writing, which is provided thereafter. It is led. At this time, the pitch of the two beams is in the sub-scanning direction on the image writing surface (the column direction in the image writing, that is, the row pitch direction in the case of simultaneous writing of two rows).
The angle of the output optical axis is finely adjusted so that the pitch becomes a desired interval. This method corresponds to the above-described position adjustment in the y-axis direction in the position adjustment of the collimator lens.

The beam combining means may be a combination of a reflecting mirror and a translucent mirror instead of the beam combining prism. The aperture forming member 4 and the beam combining prism 5 are attached to the base 1 by an attaching member (not shown). At this time, two overlapping circular steps 1d and 1d of the base 1 are used for positioning,
Four holes 1e are used for attachment.

According to the above light source device, the base 1 having the plurality of fitting holes 1a, 1a penetrating from the front and back, and the base 1
A plurality of semiconductor lasers 2 and 2 respectively fitted on the fitting holes 1a and 1a located on the back side of the semiconductor laser and the semiconductor lasers 1b and 1b on the front surface side of the base 1 of the fitting holes 1a and 1a. And a plurality of apertures 4a and 4a for shaping laser light emitted from the collimator lenses 3 and 3, respectively, which are coaxially bonded and fixed to the two optical axes.
And a beam synthesizing prism 5 for synthesizing the laser beam substantially coaxially, the center line C of each lens support 1b is aligned with the beam pitch direction (y) emitted from the plurality of collimator lenses 3, 3. Axial direction)
Since it is configured to be located in a substantially orthogonal direction, the adhesive 6
Does not occur in the beam pitch direction due to the curing shrinkage of the adhesive, and the effect of the expansion and contraction of the adhesive 6 due to the temperature change does not occur in the beam pitch direction. Therefore, the beam pitch accuracy is excellent, and the accuracy can be stably maintained. A light source device can be provided.

Further, a plurality of collimator lenses 3, 3
Each of the collimator lenses 3, 3 was directly fixed to the lens support portions 1b, 1b integrally formed on the base 1 by being directly fixed to the lens support portions 1b, 1b integrally formed on the base 1 using the photo-curing adhesive 6. Since the light source device is configured to be fixed, the number of components of the light source device can be reduced, and the light source device can be provided at low cost. Further, since there is no intervening member such as a holder between the collimator lens 3 and the lens supporting portion 1b, the fixing member can be fixed with high accuracy without being affected by manufacturing errors of the intervening member. Further, a lens support 1 in which the collimator lens 3 is integrally formed with the base 1.
Since it is configured to be directly fixed to b, a tightening portion such as a screw is eliminated, and there is no displacement of parts at the time of tightening, so that a highly accurate light source device can be provided.

Further, since the lens supporting portion 1b is formed symmetrically with respect to a line perpendicular to the beam pitch direction, distortion due to curing shrinkage in the beam pitch direction is cancelled, and the direction of curing shrinkage is orthogonal to the beam pitch direction. Therefore, the directionality of the curing shrinkage is further improved, and the position can be adjusted with higher accuracy.

Further, since the lens supporting portion 1b is formed in an arc-shaped cross section slightly larger in diameter than the outer circumference of the collimator lens 3, the lens supporting portion 1b and the collimator lens 3 are formed.
Are arranged concentrically, the adhesive layer formed between the collimator lens 3 and the lens support 1b has a uniform thickness. For this reason, since the entire surface of the adhesive layer is uniformly solidified, uneven curing is eliminated, and misalignment of the collimator lens can be prevented.

Further, since the lens supporting portion 1b is formed in an arc-shaped cross section having a radius of curvature substantially larger than the radius of curvature of the outer peripheral circle of the collimator lens 3 by the thickness of the adhesive layer, the lens supporting portion 1b is formed.
And the collimator lens 3 are arranged concentrically,
The adhesive layer formed between the collimator lens 3 and the lens support 1b has a desired adhesive layer thickness and a uniform thickness. For this reason, since the entire surface of the adhesive layer is uniformly solidified, uneven curing is eliminated, and misalignment of the collimator lens can be prevented.

Since the cross section of the lens supporting portion 1b is an arc of a semicircle or less, the adhesive layer covers only less than half of the outer periphery of the collimator lens 3, and the adhesive 6 has directionality upon curing and contraction. Therefore, the initial position of the collimator lens 3 can be offset in anticipation of the contraction amount of the adhesive 6, and the positional accuracy after curing can be improved. Further, a curing light beam can be irradiated from the opening side of the lens support portion 1b toward the side surface of the collimator lens 3, so that curing unevenness can be further reduced.

The collimator lenses 3, 3 and the base 1
A non-adhesion portion such as a gap or a groove is formed to prevent the adhesive from extending in the optical axis direction between the collimator lenses 3 and 3. , Even if a large amount of the adhesive 6 is filled, the protruding adhesive 6 does not directly adhere to the wall surface of the base 1, and the light from the adhesive 6 which has adhered to the wall surface of the base 1 and hardened. A strong curing contraction force in the axial direction (z-axis direction) does not act on the collimator lenses 3. For this reason, the positional accuracy in the optical axis direction can be improved.

In the example described above, an ultraviolet-curable adhesive was used. However, the present invention is not limited to the ultraviolet-curable adhesive, but any light-curable adhesive can be used. Further, the present invention is not limited to a light source device that generates two beams, and a light source device that generates three or more beams can be similarly used.

[0057]

As is apparent from the above description, according to the light source device of the first aspect, the base having a plurality of fitting holes penetrating on the front and back sides, and the fitting holes located on the back side of the base are respectively formed in the fitting holes. A plurality of semiconductor lasers to be fitted, a plurality of collimator lenses that are respectively adhered and fixed to the lens support portion on the base surface side of the fitting hole and the optical axis of the semiconductor laser, and emitted from the collimator lenses. A plurality of apertures for shaping the laser beam, and a beam combining means for combining the laser beams substantially coaxially, wherein the center line of each of the lens support portions is emitted from the plurality of collimator lenses. Is characterized by being located substantially orthogonal to the beam pitch direction, so that the influence of adhesive curing shrinkage does not occur in the beam pitch direction, and the temperature It does not occur in the beam pitch direction effects of expansion and contraction of the adhesive by reduction, excellent beam pitch accuracy, besides stably be provided a light source device capable of maintaining accuracy.

According to the light source device of the second aspect, in the light source device of the first aspect, the plurality of collimator lenses are provided on a lens support unit integrally formed on the base using a light-curing adhesive. Since the light source device is directly fixed, the number of parts of the light source device can be reduced in addition to the effect of claim 1, and the light source device can be provided at low cost. Further, since there is no intervening member such as a holder between the collimator lens and the lens supporting portion, it can be fixed with high accuracy without being affected by manufacturing errors of the intervening member. In addition, since the collimator lens is configured to be directly fixed to the lens support part that is integrally molded with the base, tightening parts such as screws are eliminated, eliminating misalignment of parts at the time of tightening, and providing a highly accurate light source device. can do.

According to a third aspect of the present invention, in the light source device according to any one of the first to second aspects, the lens support portion is configured to be line-symmetric with respect to a line orthogonal to the beam pitch direction. Claim 1
In addition to the effects of the light source device described in any one of (1) to (2), distortion due to curing shrinkage in the beam pitch direction is canceled out, and the direction of curing shrinkage is limited to a direction orthogonal to the beam pitch direction. Performance is further improved, and the position can be adjusted with higher precision.

According to the light source device of the fourth aspect, in the light source device according to any one of the first to third aspects, the lens support portion has a cross-sectional circle slightly larger in diameter than the outer peripheral circle of the collimator lens. Since it is characterized by being formed in an arc shape, in addition to the effect of the light source device according to any one of claims 1 to 3, by arranging the lens support portion and the collimator lens concentrically, the collimator lens The adhesive layer formed between the lens support portions has a uniform thickness. For this reason, the entire surface of the adhesive layer is solidified uniformly, so that curing unevenness is eliminated, and displacement of the collimator lens is prevented.

According to a fifth aspect of the present invention, in the light source device according to any one of the first to third aspects, the thickness of the adhesive layer is substantially equal to the radius of curvature of the outer peripheral circle of the collimator lens. The light source device according to any one of claims 1 to 3, wherein the lens support portion and the collimator lens are concentrically arranged because the light source device is formed in a circular arc shape with a large radius of curvature. By doing so, the adhesive layer formed between the collimator lens and the lens support has a desired adhesive layer thickness and a uniform thickness. For this reason, the entire surface of the adhesive layer is solidified uniformly, so that curing unevenness is eliminated, and displacement of the collimator lens is prevented.

According to a sixth aspect of the present invention, in the light source device according to any one of the fourth to fifth aspects, a cross section of the lens supporting portion is an arc of a semicircle or less. Therefore, in addition to the effect of the light source device according to any one of claims 4 to 5, the adhesive layer only covers half or less of the outer periphery of the collimator lens, and the adhesive has a directionality upon curing and contraction. The initial position of the collimator lens can be offset in anticipation of the contraction amount of the agent, and the positional accuracy after curing can be improved. Further, a curing light beam can be irradiated from the opening side of the lens support toward the side surface of the collimator lens, and curing unevenness is further eliminated.

According to the light source device of the seventh aspect, in the light source device of the first aspect, a non-adhesive portion is formed between the collimator lens and the base in the optical axis direction. Claims 1 to 6
In addition to the effect of the light source device according to any of the above, due to the presence of the non-adhesive portion formed between the base wall surface and the collimator lens, even if a large amount of adhesive is filled, The adhesive hardly adheres to the base wall surface and hardens in the optical axis direction (z-axis direction) due to the adhesive that has hardened and adhered to the base wall surface does not act on the collimator lens. For this reason,
Position accuracy in the optical axis direction can be improved.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a light source device according to the present invention.

FIG. 2 is a schematic front view including a lens supporting portion when a collimator lens is bonded.

FIG. 3 is a diagram illustrating an example of a conventional light source device.

FIG. 4 is a diagram showing another example of a conventional light source device.

[Explanation of symbols]

 Reference Signs List 1 base 1a fitting hole 1b lens support 2 semiconductor laser 3 collimator lens 4a aperture 5 beam combining prism C center line

Claims (7)

[Claims] 1. A base having a plurality of fitting holes penetrating from front to back, a plurality of semiconductor lasers respectively positioned on the back surface of the base and fitted into the fitting holes, and a base surface of the fitting holes. A plurality of collimator lenses, each of which is adhesively fixed coaxially to the optical axis of the semiconductor laser,
In a light source device having a plurality of apertures for shaping a laser beam emitted from the collimator lens and a beam combining unit for combining the laser beams substantially coaxially, a center line of each of the lens supporting portions is a plurality of A light source device located substantially orthogonal to a beam pitch direction emitted from the collimator lens. 2. The light source device according to claim 1, wherein each of the plurality of collimator lenses is directly fixed to a lens support unit formed integrally with the base by using a photo-curable adhesive. . 3. The light source device according to claim 1, wherein the lens support portion is configured to be line-symmetric with respect to a line perpendicular to a beam pitch direction. 4. The light source device according to claim 1, wherein the lens supporting portion is formed in a circular arc shape having a diameter slightly larger than the outer circumference of the collimator lens. 5. The lens support according to claim 1, wherein the lens supporting portion is formed in an arc-shaped cross section having a radius of curvature substantially equal to the radius of curvature of the outer peripheral circle of the collimator lens by the thickness of the adhesive layer. A light source device according to any one of the above. 6. The light source device according to claim 4, wherein a cross section of the lens supporting portion is an arc of a half circle or less. 7. The light source device according to claim 1, wherein a non-adhesion portion is formed between the collimator lens and the base in an optical axis direction.