JP2004264152A - Line beam generating optical system, and laser marking apparatus mounting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a line beam generating optical system that has a simple configuration and high light utilization efficiency, and can generate a plurality of line beams having a large spread angle, and to provide an inexpensive laser marking apparatus for emitting a plurality of line beams while mounting the light beam generating optical system. <P>SOLUTION: A first rod lens 1 is arranged so that it branches laser beams into two beams having a specific opening angle each by a Fresnel beam splitter 3 and two branch beams can enter simultaneously, and two second rod lenses 4 are arranged at a specific interval between the first rod lens 1 and the Fresnel beam splitter 3. With this configuration, light beams formed by light that is emitted by refraction after entering the first rod lens 1, and line light by light after light that does not enter the first rod lens enters the second rod lens 4 for retraction and emission are synthesized for obtaining line light having a large spread angle. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a line light generating optical system capable of generating line light having a small line width and an extremely large spread angle, and a laser marking device equipped with the same.
[0002]
[Prior art]
When building a house, especially at the start of construction, it is essential to perform a task of setting a reference position for mounting various members and setting a level line for the positioning of member processing, that is, a blackout operation. Therefore, at the construction site, leveling was performed using instruments such as a level surveyor, multiple marks (black) were attached to the walls of the target structure, and they were connected to form a blacking line, which was used as a construction standard. .
However, this operation must be performed by at least two people, which is very time-consuming and inefficient. In order to solve this problem, recently, the ink marking operation has been often performed efficiently using a laser marking device having a line light irradiation function. Since a laser marking device can easily perform a marking operation by one person, the laser marking device is becoming an indispensable building work tool for building work.
[0003]
The so-called "Tachi-Line" which draws a vertical line from the floor to the wall and the ceiling and two "Tachi-Lines" are simultaneously illuminated to draw a right angle line on the ceiling. There are various lines, such as a "Roku line" that draws a horizontal line on a wall, and a "ground ink" that irradiates a focused laser beam on the floor directly below a laser marking device.
[0004]
In order to accurately perform a blackout operation using a laser blackout device, it is desirable that the line width of the line light be small. Further, in order to efficiently perform the blackout operation, it is desired that the spread angle of the line light per line be as large as possible. The line light generating optical unit of the conventional laser marking device basically consists of a laser light source and a collimating lens that converts the laser light emitted from the laser light into collimated light with a constant beam diameter, and a rod lens that converts the collimated light into line light. It is configured. Conventionally, in order to reduce the line width of the line light, it has been coped with by reducing the beam diameter of the collimated light.
[0005]
In addition, in order to obtain a wide-angle line light, a plurality of line light generating optical units are used, and a method of obtaining a wide-angle line light by connecting the line light emitted from each optical unit or a single rod lens. On the other hand, Patent Document 1 proposes a method of connecting two line lights generated by using two laser light sources.
[Patent Document 1]
JP 2003-14456 A
[Problems to be solved by the invention]
First, the principle of generating line light when a rod lens is used will be described with reference to FIG.
A rod lens is a cylindrical lens whose side surface is a transmission surface. FIG. 2 shows a state in which collimated light is incident on the rod lens and line light is generated. Now, for simplicity, consider one beam. The angle (incident angle) between the normal and the beam at the incident point (incident angle) is α, the angle (refractive angle) between the beam refracted inside the rod lens and the normal (β), the refractive index of the lens n, and the refractive index of air Is set to 1.
At this time, the refraction angle β can be obtained from an equation satisfying Snell's law 1 · sin α = n · sin β. Next, since the angle between the normal and the beam at the emission point is β, if the angle between the beam and the normal after emission from the rod lens is γ, then n · sin β = 1 · sin γ according to Snell's law, Α = γ by comparing the two equations. That is, the larger the incident angle of the beam, the larger the outgoing angle.
[0007]
Therefore, when the beam is made to enter the entire rod lens diameter, the spread angle of the line light becomes maximum. At this time, since there is no refracting action of the lens in the longitudinal direction of the rod lens, the light goes straight without being refracted. That is, when laser light is incident on the rod lens, the emitted light is stretched in one direction and converted into line light. At this time, as the incidence ratio of light to the rod lens diameter increases, the spread angle of the line light increases.
[0008]
Next, the intensity distribution characteristics of laser light will be described. The intensity distribution of the laser light has a Gaussian distribution. That is, the light emitted from the laser light source is spread radially, and the intensity is higher because the light becomes denser toward the center, and the intensity becomes weaker and weaker toward the periphery. Therefore, when line light is generated using a rod lens, a portion having a large spread angle is formed of light having a low light intensity in a peripheral portion. Further, since the area of the line light is larger than that of the dot light before the conversion, the light intensity per unit area is reduced. That is, the line light of the portion having a large divergence angle is less visible to human eyes than the line light of the portion having a small divergence angle, and may not be visible depending on the surrounding illuminance condition.
[0009]
Therefore, in order to solve the above problem, a method using only a central portion having a large light intensity has been adopted in the conventional method. According to this method, in order to make the light of the central portion having a large light intensity incident on the entire rod lens diameter, the beam diameter must be increased, and the line light beam width is increased. It is disadvantageous to get.
[0010]
Since the red semiconductor laser, which is often used in general laser marking devices, has an elliptical beam shape, the laser light source and rod lens are arranged so that the minor axis of the ellipse matches the line width direction. are doing. However, when a green laser having a circular beam shape is used as a light source, the above problem remains.
[0011]
Further, in the conventional method, since only a portion having a high light intensity is used, there is a problem that the light use efficiency must be reduced.
[0012]
Next, there is a method of obtaining a wide-angle line light by using a plurality of line light generation optical units as described above to obtain a wide-angle line light, and connecting the line lights emitted from the respective optical units, There is a problem that the cost of the apparatus increases as the number of laser light sources mounted increases. As a means for solving this problem, a method of connecting two line lights generated by using two laser light sources for one rod lens disclosed in Patent Document 1 has been proposed. According to this method, the line light generating optical unit is composed of two sets of laser light source / collimating lens and one rod lens, so that the cost can be reduced by one rod lens. Since the method is the same as the conventional method, there is a problem that the light use efficiency is not improved and the use efficiency is poor.
[0013]
An object of the present invention is to solve such a conventional problem and to provide a line light generating optical system having a high light utilization efficiency and a large spread angle, and a laser marking device using the same.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a laser beam splitting by a Fresnel type beam splitter into two lights having a predetermined opening angle with each other, so that the two split lights are simultaneously incident on a rod lens. One feature is that the first rod lens is arranged, and two second rod lenses are arranged at a predetermined interval between the first rod lens and the Fresnel beam splitter. With such a configuration, after being incident on the first rod lens, the line light formed by the light refracted and emitted, and the light not completely incident on the first rod lens are incident on the second rod lens and refracted. The emitted light and the line light are combined to obtain a line light having a large divergence angle. With this configuration, all light can be incident on the rod lens, so that the light use efficiency is significantly improved.
[0015]
Another feature of the present invention is that a light reflecting surface for reflecting incident light is provided on at least a part of the first rod lens incident surface side. With this configuration, the wide-angle line light obtained by the reflection from the first rod lens and the line light formed by the light that is incident on a part of the first and second rod lenses and then refracted and emitted are generated. It is possible to obtain line light that is synthesized, has high light use efficiency, and has a large spread angle.
[0016]
Other features of the present invention include a semiconductor laser, a collimator lens that converts a light beam emitted from the semiconductor laser into collimated light, and at least one half mirror that separates the collimated light into reflected light and transmitted light. At least one of the reflected light and the transmitted light is branched by a Fresnel beam splitter into two lights having a predetermined opening angle, and a first rod lens is formed so that the two branched lights are incident simultaneously. One feature is that the second rod lens is disposed at a predetermined interval between the first rod lens and the Fresnel beam splitter. Further, a light reflecting surface for reflecting incident light is provided on at least a part of the first rod lens incident surface side. This makes it possible to form a plurality of line lights having high light use efficiency and a large spread angle.
[0017]
Other features of the present invention include a semiconductor laser, a collimator lens that converts a light beam emitted from the semiconductor laser into collimated light, at least a first half mirror that separates the collimated light into reflected light and transmitted light, A first line light generating optical system arranged in the optical path of the reflected light, a second half mirror arranged in the optical path of the transmitted light, and a second line light arranged in the optical path of the reflected light of the second half mirror And a third line light generating optical system disposed on an optical path of light transmitted through the second half mirror. The first, second, and third line light generating optical systems include a Fresnel beam splitter and one It is composed of a first rod lens and two rod lenses, and further has a reflection surface formed on a part of the first rod lens on the incident surface side. With this configuration, it is possible to efficiently and easily obtain a large number of different types of line light.
[0018]
Another feature of the present invention is that a laser marking device equipped with the above-described line light generating optical system is configured. In this case, it is possible to provide a low-cost laser marking device for irradiating a plurality of line lights with a large spread angle.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
The line light generating optical system according to the present invention basically includes a laser light source, a Fresnel beam splitter, and a rod lens. FIG. 1 shows an embodiment of the present invention, in which a laser light source is shown on the left side of the figure, but is not shown. Reference numeral 1 denotes a cross section of the first rod lens, which has a cylindrical shape elongated in a direction perpendicular to the paper surface. In this embodiment, BK7 (refractive index 1.5), which is a glass material, is used as the material of the rod lens 1. The diameter of the lens 1 was 3 mm and the length was 15 mm.
[0020]
Reflection surfaces 2a and 2b that reflect a part of incident light are formed on the incident surface side of the lens surface of the rod lens 1. The optical reflecting surfaces 2a and 2b are formed at two places in the present embodiment. That is, as viewed from the cross-sectional shape of the rod lens 1, as shown in FIG. 1, the reflecting surfaces 2a and 2b are formed on the upper and lower circumferential surfaces except for the circumferential surface 2c near the optical axis on the light incident side. The optical reflecting surfaces 2a and 2b can be formed by forming a metal thin film such as Cr or Al by a method such as a vacuum evaporation method or a sputtering method. A Fresnel beam splitter 3 having a prism angle of 20 ° and a refractive index of 1.49 is disposed at a position 7.1 mm away from the center of the rod lens 1. The light split by the beam splitter 3 has a separation angle of 20 ° from each other. Further, two second rod lenses 4 are arranged at a position 4.6 mm away from the center of the first rod lens 1. In the present embodiment, the diameter of the second rod lens 4 is 2 mm, and the two rod lenses 4 are arranged at a distance of 3.4 mm from the center. Note that the second rod lens 4 has no reflection surface. Next, in this embodiment, the laser beam incident on the Fresnel beam splitter 3 is a circular collimator beam having a diameter of 2 mm. As described above, the laser light has the light intensity distribution, and the light in the peripheral portion becomes invisible after being converted into the line light. Although the appearance of the line light depends on the irradiation environment, it is assumed here that the light is visible when the line light is used up to 1 / e ² of the maximum intensity at the center of the beam. This corresponds to 1 / 1.52 or 0.66 times the apparent beam diameter. Therefore, the area of the laser light that can be seen when converted to line light is 2 × 0.66 = 1.32 mm. The light travels straight with an inclination of 10 ° with respect to the x-axis by the Fresnel beam splitter 3, and most of the light is converted into line light by being reflected or incident by the first rod lens 1. The laser light that cannot be incident on the first rod lens 1 is converted into line light by the second rod lens 4 disposed on the near side, and is combined with the line light formed by reflection by the first rod lens 1.
Light having a low intensity at the peripheral portion, which becomes invisible depending on conditions when converted to line light, is also converted to line light by one of the rod lenses 1 and 4 and combined with the above-described line light. Therefore, it is possible to convert all the laser light generated from the laser light source to line light without waste. Further, the reflecting surfaces 2a and 2b provided on the surface of the first rod lens 1 make it possible to obtain line light having a wide angle of 180 ° or more.
[0021]
In the above embodiment, the Fresnel beam splitter 3 has been described as a means for splitting light, but the present invention is not limited to this. That is, the light splitting means used in the line light generating optical system of the present invention may be basically any light as long as it has a function of dividing one light beam into two or more lights. Therefore, for example, a prism, a half mirror, a cube beam splitter, a polka dot beam splitter, a diffraction grating, or the like may be used as the optical branching optical element. In particular, when applied to an optical system layout as described in the present embodiment, a Fresnel beam splitter or a diffraction grating is advantageous. When a diffraction grating is used, it is necessary to design the diffraction grating so that the light intensities of the 0th-order light and ± 1st-order light, which are branched lights, are as uniform as possible.
(Embodiment 2)
In the second embodiment, the operation of each part constituting the line light generating optical system will be described, and an example of a line generating optical system based on a combination will be described.
FIG. 3 shows a manner in which the Fresnel beam splitter 3 obtains branched light. FIG. 3 is an enlarged cross-sectional view of the Fresnel beam splitter 3 and shows a state in which one light beam of the incident light passes through the beam splitter 3. It is assumed that light is incident from the groove side of the Fresnel beam splitter 3 in parallel to the x-axis. Assuming that the inclination angle (prism angle) of the groove is θ and the angle between the light emitted from the beam splitter 3 and the x axis is ψ,
^{ψ = sin - 1 {sinθ ×} (n 2 -sin 2 θ) 1/2 -sinθcosθ} (1)
Given by Hereinafter, the derivation of the formula is omitted, and only the result is described.
FIG. 4 shows a state where light having an angle of ψ with the x-axis is reflected on the surface of the first rod lens 1. Assuming that the angle between the reflected light and the x-axis at a point rotated counterclockwise by an angle か ら from the y-axis is ξ, ξ = 2Θ−ψ (2)
It becomes.
[0022]
Next, the position of the Fresnel beam splitter 3 when irradiating the light beam with the highest light intensity to the point at the angle Θ of the starting point on the X-axis side of the reflection surface 2a of the first rod lens 1 is x = −R (sinΘ + cotψ × cosΘ) ( 3)
It becomes. That is, the beam splitter 3 may be arranged at a position away from the center of the first rod lens 1 by R (sin {+ cot} × cos}) toward the light source.
[0023]
FIG. 5 shows the range of the reflecting surfaces 2a and 2b and the transmitting surface 2c formed on the surface of the first rod lens 1. As is clear from FIG. 5, the contact point between the light and the first rod lens 1 is at a position rotated counterclockwise by an angle か ら from the y-axis. No reflecting surface is required outside the contact point on the first rod lens 1. Therefore, one of the end surfaces of the reflecting surfaces 2a and 2b is determined by the contact point between the first rod lens 1 and the light beam. Next, the other end surfaces of the reflection surfaces 2a and 2b are determined by the maximum value of the spread angle of the line light. Assuming that the angle of the end face of the reflecting surface at this time is Θmax, from the equation (2), （max = (Θ + ψ) / 2 (4)
It becomes.
[0024]
Therefore, the range of the reflection surfaces 2a and 2b on the surface of the first rod lens 1 is δr = Θmax−ψ = (ξ + ψ) / 2−ψ = (ξ−ψ) / 2 (5).
Similarly, the range of the transmission surface 2c is δt = π / 2−Θmax = π / 2− (ξ + ψ) / 2 = (π−ξ−ψ) / 2 (6)
It becomes.
[0025]
Next, FIG. 6 shows a state in which light having an inclination of ψ with respect to the x-axis enters the first rod lens 1. Assuming that the angle between the light emitted from the first rod lens 1 and the x axis is ω, ω = (π − {− 2}) / 3 (7)
It becomes.
[0026]
Finally, the irradiation range of the branched light to the first rod lens 1 will be described. FIG. 4 shows a state in which the first rod lens 1 is irradiated with two branched lights having an inclination of ψ with respect to the x-axis. As is apparent from FIG. 4, the light most efficiently hits the first rod lens 1 because the light is applied from the intersection (minus side) of the circle representing the first rod lens 1 and the x-axis to the point between the contact point of the light ray and the circle. If it exists. That is, the light use efficiency is highest when the width (beam diameter) of the light matches the interval between the two lights. Assuming that the radius of the first rod lens 1 is R, the required light width d is d = R {(1 + tan ² }) ^1/2 -tan {x cos} (8)
It becomes.
[0027]
Therefore, a line light generating optical system that generates a line light having a divergence angle of 240 ° (an angle between the x-axis and a light ray of 120 °) using a laser beam having an apparent incident beam diameter of 2 mm will be described.
[0028]
Since the maximum value of the divergence angle is formed by reflected light, 2 よ り −ψ = 120 ° from Expression (2), and Θ = 60 ° + ψ / 2 (9)
It becomes. Here, the line light composed of the reflected light and the transmitted light from the first rod lens 1 needs to be continuous. The condition that the reflected light and the transmitted light are continuous is ψ ≦ ω (10)
At this time, when the expressions (9) and (7) are substituted into the expression (10) and summarized, ψ ≦ 12 °. Therefore, if a margin is set to ψ = 10 °, it is understood from Expression (1) that the Fresnel beam splitter 3 having a prism angle of 20 ° and a refractive index of 1.49 is suitable.
[0029]
Next, the optimum diameter of the first rod lens 1 is calculated. Now, assuming that light within a range of 0.66 times the apparent beam diameter of the laser light is a range that can be easily recognized even when converted to line light, the range of laser light to be converted to line light is 2.0 × 0.66 = 1.3 mm Therefore, in equation (8), d = 1.3 mm,
If ψ = 10 °, R = 1.57 mm. That is, among the commercially available rod lenses, those having an optimum diameter are rod lenses having a diameter of 3.0 mm.
[0030]
Next, the reflecting surfaces 2a and 2b and the transmitting surface 2c formed on the surface of the first rod lens 1 will be described. Since the target value of the spread angle of the line light is 240 ° (the angle between the x-axis and the light ray is 120 °), 、 r = 55 ° is obtained by substituting ξ = 120 ° ψ = 10 ° into the equation (5). Can be
[0031]
Further, the position of the beam splitter 3 will be described. For example, when it is desired to irradiate the light beam having the highest intensity on the first rod lens 1 at a position 45 ° from the y-axis, the calculation is performed by inserting Θ = 45 °, ψ = 10 ° R = 1.5 mm into the equation (3). Then, x = −1.5 (sin45 ° + cot10 ° × cos45 °) ≒ −7.1 mm
Is obtained. That is, it is understood that the Fresnel beam splitter 3 should be disposed at a position 7.1 mm away from the center position of the first rod lens 1 toward the light source. The layout of the Fresnel beam splitter 3 and the first rod lens 1 is determined as described above, and the second rod lens 4 is arranged according to the layout. The line light formed by the first rod lens 1 was carefully arranged so as not to be shaken by the second rod lens 4. As a result, two second rod lenses 4 were arranged at a position 4.6 mm away from the center of the first rod lens 1. The diameter of the second rod lens 4 is 2 mm, and the two second rod lenses 4 are arranged at a distance of 3.4 mm from the center.
[0032]
According to the concept described above, it is possible to generate wide-angle line light with high light use efficiency.
[0033]
(Embodiment 3)
A method for efficiently obtaining a wide-angle line light by using one ordinary first rod lens 1 and one Fresnel beam splitter 3 without a reflection part will be described.
[0034]
In the third embodiment as well, assuming that the apparent beam diameter of the laser light is 2 mm, and light within a range of 0.66 times that of the laser light is easily visible even when converted to line light, the laser light is converted to line light. The range of the power laser beam is 2.0 × 0.66 = 1.3 mm.
[0035]
Assuming that a rod lens having a diameter of 3 mm is used in the same manner as in the second embodiment, calculation is performed by adding R = 1.5 mm and ψ = 10 ° to equation (8).
d = 1.5 ｛(1 + tan ² 10 °) ^1/2 −tan10 °｝ × cos10 ° ≒ 1.2 mm. As described above, since the range of the laser light to be converted to the line light is 1.3 mm, it is considered that most of the light enters the rod lens although there is a slight loss. The position of the Fresnel beam splitter 3 when the strongest light passes through the center of the region d is obtained from x = − (R / 2) ｛(1 + tan ² ψ) ^1/2 / tan {+1} (11).
[0036]
If the same Fresnel beam splitter 3 as in the second embodiment is used,
Substituting R = 1.5 mm ψ = 10 ° into Expression (11), x = − (1.5 / 2) ｛(1 + tan ² 10 °) ^1/2 / tan10 ° + 1｝ ≒ -5
It becomes. That is, the Fresnel beam splitter 3 may be disposed at a position 5 mm away from the center of the rod lens. At this time, all the light applied to the rod lens passes through the inside of the rod lens and becomes a line light, and the spread angle becomes about 174 ° when the refractive index of the rod lens is about 1.5 (FIG. 7).
[0037]
(Embodiment 4)
An embodiment in which the line light generating optical system of the present invention is mounted on a laser marking device will be described. As shown in FIG. 8, the laser marking device 10 basically includes an optical system 5 and a support mechanism 6 for keeping the optical system horizontal.
[0038]
FIG. 9 schematically shows the line light generating optical system 5. A laser beam emitted from a semiconductor laser 7 arranged in a horizontal direction with respect to the main body of the laser marking device 10 is converted by a collimator lens 8 into collimated light (parallel light) B1 having a circular beam cross-sectional shape. In the present embodiment, the beam diameter of the collimated light B1 is set to be 2 mm. The collimated light B1 is incident on the beam splitter 11 having two light separation surfaces, and is split into light in three directions. The first light separation surface 50 has such a characteristic that 70% of the incident light is reflected and 30% is transmitted. Therefore, 70% of the incident light B1 is reflected by the first light separation surface 50, and becomes a light ray R1. The remaining 30% of the light passes through the inside of the beam splitter 11 and becomes transmitted light T1. Since the second light separation surface 60 has a characteristic that 40% of incident light is reflected and 60% is transmitted, 40% of R1 is reflected at the second light separation surface 60 to be reflected light R2. The remaining 60% of the light passes through the second light separation surface 60 and becomes a light beam T2. Therefore, by arranging the line light generating optical system 15 on the optical path of each light beam, it is possible to efficiently obtain wide-angle line light. In the line light generating optical system 15 disposed on the optical path of the light beam T1, the rod lens is disposed in a vertical direction in which the longitudinal direction of the rod lens is orthogonal to the emission direction of the semiconductor laser 7. Therefore, the obtained line light is horizontal line light. Note that the line light generating optical system 15 used at this time uses the one described in the third embodiment. Next, in the line light generating optical system 15 disposed on the optical path of the light ray R2, the rod lens is disposed in a direction orthogonal to the above-described rod lens for generating horizontal line light. Therefore, the obtained line light is vertical line light. The line light generating optical system 15 used at this time uses the one described in the first embodiment.
[0039]
In the line light generating optical system 15 arranged on the optical path of the light beam T2, the rod lens is arranged such that the longitudinal direction of the rod lens is parallel to the emission direction of the semiconductor laser 7. For this reason, the generated line light is distributed right and left as vertical lines. The line light generating optical system 15 used at this time uses the one described in the first embodiment. By mounting the line light generating optical system 15 of the present invention on the laser marking device 10 in this manner, a wide-angle line light can be easily and efficiently irradiated. Can be used to generate line light in various directions.
[0040]
【The invention's effect】
As described above, by using the line light generating optical system of the present invention, it is possible to efficiently obtain line light having a large divergence angle by a simple method. Further, by mounting the line light generating optical system of the present invention on a laser marking device, a wide-angle line light can be easily and efficiently irradiated. Line light can be generated in various directions. Therefore, it has become possible to generate a plurality of blackout laser line lights at low cost. As a result, it has become possible to provide a low-cost laser marking device for irradiating a plurality of lines of light, which has conventionally been very expensive.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a line light generating optical system of the present invention.
FIG. 2 is a diagram illustrating the principle of generating line light when a rod lens is used.
FIG. 3 is an explanatory diagram of a Fresnel beam splitter.
FIG. 4 is a schematic diagram showing a state of reflected light on a rod lens surface.
FIG. 5 is a schematic diagram showing a range of a reflection surface and a transmission surface of a rod lens surface.
FIG. 6 is a schematic view showing a state of light transmitted through a rod lens.
FIG. 7 is a schematic view showing another embodiment of the line light generating optical system of the present invention.
FIG. 8 is a schematic view of a laser marking device equipped with the line light generating optical system of the present invention.
FIG. 9 is a configuration diagram showing one embodiment of an optical system of the laser marking device of the present invention.
[Explanation of symbols]
1 is a first rod lens, 2a and 2b are light reflection surfaces, 2c is a transmission surface, 3 is a Fresnel beam splitter, 4 is a second rod lens, 5 is an optical system, 6 is a support mechanism, 7 is a semiconductor laser, 8 Is a collimator lens, 10 is a laser marking device, and 15 is a line light generating optical system.

Claims (9)

The beam is split by a beam splitting unit disposed in front of the first rod lens, and each of the line lights formed by the reflected light and the transmitted light from the rod lens is synthesized by irradiating the split beam to the rod lens. A line light generating optical system for forming one continuous line light. 2. The line light generating optical system according to claim 1, wherein said beam splitting means is constituted by a Fresnel beam splitter. 2. A line light generating optical system according to claim 1, wherein said beam splitting means is constituted by a diffraction grating. A beam is branched by a beam branching unit disposed in front of the first rod lens, and a line light is formed by reflected light and transmitted light from the first rod lens by irradiating the beam after the branch to the first rod lens, Further, a second rod lens is disposed between the first rod lens and the beam splitting means, and a beam not used for line light formation by the first rod lens is transmitted through the second rod lens to form line light. A line light generating optical system, wherein each line light formed by the first and second rod lenses is combined to form one continuous line light. 5. The line light generating optical system according to claim 4, wherein said beam splitting means is constituted by a Fresnel beam splitter. 7. The line light generating optical system according to claim 6, wherein a light reflecting surface for reflecting a beam is provided on at least a part of the lens surface of the first rod lens. 5. The line light generating optical system according to claim 4, wherein said beam splitting means is constituted by a diffraction grating. The line light generating optical system according to claim 7, wherein a light reflecting surface for reflecting a beam is provided on at least a part of the lens surface of the first rod lens. A laser light source, a collimating lens that converts a light beam emitted from the laser light source into collimated light, a beam splitter that splits the collimated light into two beams, and a rod lens that converts the branched light into line light. The beam is split by a beam splitting means arranged in front of the first rod lens, and the beam after splitting is applied to the first rod lens, whereby the line light is reflected by the first rod lens and transmitted by the transmitted light. The second rod lens is arranged between the first rod lens and the beam splitting means, and a beam not used for line light formation by the first rod lens is transmitted to the second rod lens to form line light. And combining the respective line lights formed by the first and second rod lenses to form one continuous line light. Apparatus.

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