KR20210102641A - Line beam forming device - Google Patents

Abstract

An objective of the present invention is to provide a line beam forming device which has improved beam efficiency while forming a line beam by a simple configuration. To achieve the objective, the line beam forming device comprises: a light source; a beam expansion unit to expand a beam emitted by the light source; and a beam conversion unit to convert the beam expanded by the beam expansion unit. The beam expansion unit includes: a spherical lens installed on the rear end of the light source; and a pair of cylinder lenses installed on the rear end of the spherical lens. The present invention reduces the number of cylinder lenses of a beam expansion unit by two in comparison to a conventional technique, performs the same beam forming action, and simplifies the configuration of the device. Also, a conventional technique required a device for expanding the beam again after passing through a bean conversion device. However, the present invention does not require such a device to further simplify the configuration of the device. Moreover, since reduction and expansion actions for the beam are not required when converting the beam, light quantity loss is prevented to improve the efficiency of the beam.

Description

LINE BEAM FORMING DEVICE

The present invention relates to a line beam forming apparatus, and more particularly, to a line beam forming apparatus in which beam efficiency is improved while forming a line beam in a simpler configuration.

The direction of propagation of laser radiation means the intermediate direction of propagation of laser radiation, in particular when the laser radiation is not a plane wave or is at least partially divergent.

A light beam, partial beam or beam, unless otherwise indicated, does not mean the ideal beam of a geometric optical system, but of a real light beam, e.g. a Gaussian profile or a modified Gaussian profile, with an elongated beam cross-section rather than an extremely small beam cross-section. is a laser beam.

Devices of the above-described manner are well known. Typical laser light sources of these devices are, for example, Nd-YAG lasers or excimer lasers.

For example, an Nd-YAG laser that is not operated as a single-mode laser has a beam quality factor M ² of about 8 to 25. The diffraction index M ² is a measure of the quality of the laser beam. For example, a laser beam with a Gaussian-profile has a diffraction index M ² of 1.

The diffraction rate M ² approximately corresponds to the number of modes of laser radiation.

The diffraction rate M ² influences the focusing potential of the laser radiation. For a laser beam with a Gaussian-profile, the thickness (d. spot size) or beam waist in the focus area is proportional to the wavelength (λ) of the laser beam to be focused, and inversely proportional to the numerical aperture NA of the focusing lens. The following equation holds for the thickness of the laser beam (spot size) in the focus area:

For laser beams that do not have a Gaussian profile or have a diffraction index M ² greater than 1, the minimum thickness (size of the spot) in the focus area or the beam waist in the focus area is additionally proportional to the diffraction rate according to the following equation.

The larger the diffraction index, the more difficult it is to focus the beam waist of the laser radiation to a smaller size. The diffraction rate M ² may be of different magnitudes for two directions perpendicular to the direction of propagation of the laser radiation.

A prior art for configuring a beam linear device in consideration of such a diffraction rate is disclosed in Korean Patent Registration No. 10-951370.

In the prior art, there is a problem in that the beam is reduced before being incident to the beam converting device and then incident, resulting in loss of light quantity.

In addition, since a separate device must be added to re-enlarge the reduced beam, there is a disadvantage in that the overall configuration of the device is complicated.

Korean Patent Registration Publication No. 10-951370

An object of the present invention is to provide a line beam forming apparatus in which beam efficiency is improved while forming a line beam in a simpler configuration.

The present invention consists of a light source emitting a beam to solve the above problems, a beam expanding unit for expanding the beam emitted by the light source, and a beam converting unit for converting the expanded beam by the beam expanding unit and, the beam expanding unit includes a spherical lens installed at the rear end of the light source, and a pair of cylinder lenses installed at the rear end of the spherical lens.

In the line beam forming apparatus of the present invention, the beam converting unit includes a front end spherical lens array provided at the rear end of the pair of cylinder lenses and connected to a plurality of spherical lenses with cut end surfaces, and a rear end of the front end spherical lens array. A beam converting means array installed in the spherical lens, each of which is installed corresponding to each of the plurality of spherical lenses, and comprising a plurality of beam converting means for rotating a partial beam, and a plurality of spherical lenses installed at the rear end of the beam converting means and from which the end surfaces are cut It is characterized in that it consists of a rear-end spherical lens array formed by being connected.

In the line beam forming apparatus of the present invention, each of the beam converting means is composed of a combination of a plurality of prisms or a combination of mirrors or a combination of prisms and mirrors so that the incident partial beam is rotated and output is vertically inverted, and each beam is converted The means are arranged obliquely on the xy plane perpendicular to the beam traveling direction (z direction), and are characterized in that they are arranged in a line in the vertical direction.

In the line beam forming apparatus of the present invention, each of the beam converting means is formed at a symmetrical angle to each other when viewed from the front, and the first and second mirrors arranged to form an apex downward, and horizontally disposed below the apex. It consists of a third mirror that is formed, wherein the first and second reflective surfaces are respectively formed on the outside of the first and second mirrors, and a third reflective surface is formed on the upper surface of the third mirror.

In the line beam forming apparatus of the present invention, a beam delivery optical system is installed between the light source and the beam expander, the beam delivery optical system includes a beam diameter control optical system, and the beam diameter control optical system includes a beam output from the light source. It is characterized in that it consists of an afocal zoom lens optical system for uniformly adjusting the diameter.

In the line beam forming apparatus of the present invention, the beam delivery optical system includes a speckle reducing part disposed behind the beam diameter adjusting optical system, and the speckle reducing part includes an upper prism and a lower prism installed below the upper prism. and two beam splitters installed between the upper prism and the lower prism and disposed to face each other, and the transmittance reflectance of the two beam splitters is determined so that the delay distance of the light source is larger than the possible interference distance of the light source. characterized by being

In the line beam forming apparatus of the present invention, a single axis beam diameter control optical system is installed behind the beam converting means, and the single axis beam diameter control optical system is formed as a non-focus zoom optical system, and the beam of the single axis direction emitted from the beam converting means is output from the beam converting means. It is characterized in that it is formed to enlarge the diameter of.

In the line beam forming apparatus of the present invention, a long-axis optical system is installed at the rear of the short-axis beam diameter control optical system, the long-axis optical systems are disposed opposite to each other, and a fly's eye lens unit for equalizing the brightness of the long-axis beam, and the fly's eye It is disposed at the rear of the lens unit and it is characterized in that it consists of a zoom optical system and a long axis projection imaging optical system for adjusting the length of the long axis.

In the line beam forming apparatus of the present invention, a short axis projection imaging optical system is installed behind the long axis optical system, and the short axis projection imaging optical system is formed as a zoom lens optical system to adjust the line width in the short axis direction.

In the present invention, a beam diameter control optical system is installed to constantly adjust the diameter of the beam emitted from the light source.

In addition, by providing the speckle reduction unit, it has an effect of preventing the non-uniform and non-uniform distribution of the line beam by the speckle.

The present invention makes it possible to perform the same beam forming operation while reducing the number of cylinder lenses by two compared to the prior art in the configuration of the beam expanding unit, thereby simplifying the configuration of the apparatus.

In addition, in the prior art, a device for enlarging the beam again after passing through the beam converting device was required, but in the present invention, such a device is unnecessary and the configuration of the device becomes simpler, thereby reducing the cost and time and effort required for manufacturing the device. have a savings effect.

In addition, since a separate action for reducing and expanding the beam is unnecessary during beam conversion, loss of light quantity is prevented, thereby improving the efficiency of the beam.

In the present invention, the size of the uniaxial spot is changed while changing the NA (Numerical Aperture) by adjusting the diameter of the incident light beam due to the installation of the uniaxial imaging optical system.

In addition, as a long-axis optical system, a fly-eye lens unit 610. Fly Eye Lens is installed to equalize a long-axis beam, and a long-axis projection imaging optical system made of a zoom lens optical system is installed to adjust the length of the long axis.

In addition, by installing a single-axis projection imaging optical system consisting of a zoom lens optical system, the line width in the short-axis direction is adjusted to have the effect of changing the focal length from 300mm (NA 0.02) to 600mm (NA 0.01) for an incident beam of 12mm.

1 is a schematic diagram showing the configuration of an apparatus according to the present invention.
2 is a view showing a beam diameter adjusting optical system in the present invention.
3 is a view showing a speckle reducing element portion in the present invention.
4 is a view showing a beam expander in the present invention.
5 is a diagram illustrating a beam converter in the present invention.
6 is a view showing a spherical lens array in the beam conversion unit of the present invention.
7 to 9 are views showing an embodiment of the beam converting means in the beam converting unit of the present invention.
10 is a view showing a uniaxial beam diameter adjusting optical system in the present invention.
11 is a diagram showing a long-axis optical system in the present invention.
12 is a diagram showing a single-axis projection imaging optical system in the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 is a schematic diagram showing the configuration of an apparatus according to the present invention.

The beam forming apparatus according to the present invention includes a light source 100 , a beam delivery optical system 200 installed in the rear of the light source 100 in the beam irradiation direction, and a beam expanding unit installed in the rear of the beam delivery optical system 200 ( 300), the beam converting unit 400 installed at the rear of the beam expanding unit 300, the uniaxial beam diameter adjusting optical system 500 installed at the rear of the beam converting unit 400, and the uniaxial beam diameter It consists of a long-axis optical system 600 installed in the rear of the adjustment optical system 500 and a short-axis optical system 700 installed in the rear of the long-axis optical system 600 .

The light source 100 may be implemented as, for example, an Nd-YAG-laser or an excimer laser. The laser radiation emitted from the light source 100 is formed to have a circular cross-section.

In this embodiment, the radiation of the laser light source 100 has a diffraction rate Mx ² =My ² = 14 in the x-direction and the y-direction.

In the present invention, the traveling direction of the beam is defined as the z direction, the long axis direction of the lime beam in a plane perpendicular to the z direction is the x axis direction, and the short axis direction is defined as the y direction.

The diameter of the beam (b) emitted from the light source 100 is made of 5 ± 1.0mm.

2 is a view showing a beam diameter adjusting optical system in the present invention.

The beam delivery optical system 200 includes a beam diameter control optical system 210 and a speckle reduction unit 220 .

The beam diameter control optical system 210 includes an afocal system and a zoom optical system. Here, the afocal system refers to an optical system in which parallel incident rays are emitted in parallel, and is also called a telescopic optical system. In addition, the zoom optical system refers to an optical system in which the magnification or focal length of the optical system is continuously changed.

Beam diameter control optical system 210 sequentially in the direction in which the light is incident, a first group of lenses 211 having a positive refractive power, a second group of lenses 212 having a negative refractive power, and a negative refractive power The branch consists of a third group of lenses 213 and a fourth group of lenses 214 having positive refractive power.

In the present embodiment, the plurality of lens groups of the beam diameter control optical system 210 are configured in an order having positive, negative, negative, and positive refractive power, but may be configured in a different order if the zoom lens optical system is configured.

The lenses 211 of the first group and the lenses 214 of the fourth group are configured such that the lenses 212 of the second group and the lenses 213 of the third group move nonlinearly along the zoom trajectory in a fixed state. do.

The diameter of the beam b emitted from the light source 100 is 4 to 6 mm, which has various sizes, and the diameter of the beam b emitted by the zoom action of the beam diameter control optical system 210 as described above. As shown in FIG. 2, it acts as a constant beam of 5 mm.

3 is a view showing a speckle reducing element portion in the present invention.

The speckle reduction unit 220 includes two prisms P1 and P2 and two beam splitters BS1 and BS2.

The first and second prisms P1 and P2 are formed in a triangular prism shape with a known configuration, and are disposed on the upper and lower portions of the first beam splitter BS1 and the second beam splitter BS2 with their long sides facing the bottom. do.

The first and second beam splitters BS1 and BS2 are devices for splitting light into two at a constant ratio as a known configuration, and are arranged to face each other.

In the first and second beam splitters (BS1, BS2), the light transmittance and reflectance can be arbitrarily determined.

The embodiment describes a case where both beam splitters are 50% transmitted and 50% reflected. Here, 100% transmission is assumed at P1, P2, and the interface.

First, while passing through the beam diameter control optical system 210 and incident from the left, 50% is transmitted and 50% is reflected while passing through the first beam splitter BS1.

Only 50% of the transmitted beam passing through the first beam splitter BS1 is transmitted through the second beam splitter BS2, and 25% of the first incident beam is emitted.

On the other hand, 50% of the reflected beam reflected by the first beam splitter BS1 is reflected by the first prism P1 and is incident on the second beam splitter BS2.

Therefore, the sum of the primary beams totals 50%.

On the other hand, 50% of the transmitted beam passing through the first beam splitter BS1 is reflected by 50% of the second beam splitter BS2, is incident on the second prism P2, and is reflected back to the first beam splitter BS1. Since it is reflected from and emitted through the second beam splitter BS2, only 6.25% of the first incident beam is emitted.

In addition, 50% of the reflected beam reflected by the first beam splitter BS1 is also reflected by the second beam splitter BS2 by 50%, so that only 6.25% of the first incident beam is emitted.

Therefore, the sum of the secondary beams becomes 12.5%.

On the other hand, the light transmittance and reflectance in the first and second beam splitters BS1 and BS2 can be arbitrarily determined. As another embodiment, the first beam splitter BS1 transmits 80% and reflects 20%, and the second beam splitter ( BS2) describes the case of 20% transmission and 80% reflection. Here, 100% transmission is assumed at P1, P2, and the interface.

As the beam incident from the left passes through the first beam splitter BS1, 80% is transmitted and 20% is reflected, and the second beam splitter BS2 transmits 20% and reflects 80%, so the first and second beam splitters BS1 and BS2 ), only 16% of the first incident beam is emitted.

On the other hand, when both the first and second beam splitters BS1 and BS2 are reflected, 16% of the first incident beam is emitted.

Therefore, as a whole, only 32% of the primary beam is emitted.

That is, comparing the two cases, in the former case, the primary transmitted beam is 50%, whereas in the latter case, the primary transmitted beam is 32%. Therefore, if the transmit reflectance of the first and second beam splitters BS1 and BS2 is adjusted, the light beam It can be seen that the more rotation in this device causes the optical path to be delayed.

As described above, if the transmit reflectance of the first and second beam splitters BS1 and BS2 is adjusted so that the delay distance of the optical path is larger than the possible interference distance of the light source 100, for example, speckle generated by the possible coherence of the laser. By this, it acts to prevent the non-uniform and non-uniform distribution of the line beams.

4 is a view showing a beam expander in the present invention.

The beam expander 300 includes a spherical lens 310 and a pair of cylinder lenses 320 and 330 in the present invention.

Each of the spherical lens 310 and the pair of cylinder lenses 320 and 330 has a generally known configuration.

The beam b1 of circular cross-section is enlarged as shown in FIG. 4 while passing through the beam expanding unit 400 composed of the spherical lens 310 and a pair of cylinder lenses 320 and 330, and the beam b2 of the elliptical cross-section. ) is formed from

When the diameter of the circular cross-section beam b1 emitted from the laser light source 100 is 5 mm, the beam b2 enlarged by the beam expander 20 has a minor axis of 5 mm and a major axis of 35 mm which is enlarged 7 times.

Even in the case of the expanded beam b2 passing through the beam expanding unit 20 , the output beam of the laser light source 100 still has diffraction coefficients Mx ² =My ² = 14 in the x-direction and the y-direction.

In the case of the present invention, the beam expander 300 is composed of a single spherical lens 310 and a pair of cylinder lenses 320 and 330, which is the same as compared to the prior art of expanding the beam in an ellipse using four cylinder lenses. By reducing the number of cylinder lenses by two while exhibiting the effect, the device has the advantage of simple configuration.

Since the cylinder lens is not easy to process, it is advantageous to use it as little as possible because it has disadvantages in that it takes cost and time to manufacture.

5 is a diagram illustrating a beam converter in the present invention. 6 is a view showing a spherical lens array in the beam conversion unit of the present invention.

The beam converting unit 400 is installed at the rear end of the front end spherical lens array 410, the beam converting means array 420 installed at the rear end of the front end spherical lens array 410, and the beam converting means array 420 It consists of a rear end spherical lens array 430 .

The front-end spherical lens array 410 and the rear-end spherical lens array 430 cut the upper and lower ends of the spherical lens s in a plane as shown in FIG. It is formed by stacking with

In this embodiment, the front end spherical lens array 410 is arranged so that the focal point of each spherical lens s is located at the center of the beam converting means 420 in the beam traveling direction (z direction).

In this case, since damage may occur to the material of the beam converting means (t), it is also possible to form a focal point in the space (c) spaced between the prisms (p) as in an embodiment to be described later.

In the above-described embodiment, the front-end spherical lens array 410 is arranged such that the focal point of each spherical lens s is located at the center of the beam moving direction (z direction) of the beam converting means 420, but is not limited thereto.

That is, in the front end spherical lens array 410, the focus of each spherical lens (s) should be formed only in the beam converting means (t), and may be formed so as to be focused on the front or rear of the beam converting means (t) in the z direction.

7 to 9 are views showing an embodiment of the beam converting means in the beam converting unit of the present invention.

The beam converting means array 420 is composed of a plurality of beam converting means (t).

Each beam converting means (t) is made of a combination of a plurality of prisms or a combination of prisms and mirrors, and various embodiments are possible.

In this embodiment, each beam converting means (t) is formed at a symmetrical angle to each other when viewed from the front, and the two first and second mirrors 421 and 422 arranged to form a vertex p downward, and the vertex p. It consists of a third mirror 423 that is horizontally arranged under the.

The first and second reflective surfaces m1 and m2 are formed on the outside of the first and second mirrors 421 and 422 , respectively, and the third reflective surface m3 is formed on the upper surface of the third mirror 423 .

On the other hand, each beam converting means (t) is arranged to be inclined at 45 degrees when viewed in the xy plane and formed to be arranged in a line in the vertical direction, thereby forming the beam converting means array 420 .

In the beam converting means (t), the image incident by the combination of the prisms is vertically inverted and emitted.

The elliptical cross-section beam b2 enlarged by passing through the beam expander 300 is converted into a beam b3 in the form of being divided into partial beams while passing through the front-end spherical lens array 410 .

Even after passing through the front-end spherical lens array 410, the diffraction rate of the entire beam b3 ^{is maintained at Mx 2} = My ² = 14, but since it is divided into 7 in the x-axis direction, each partial beam is Mx ² = 2, My ^It has a diffraction index of 2 = 14.

In the present invention, since the partial beam passes through the spherical lens s of the front end spherical lens array 410, the beam passes through the beam converting means 420 without being reduced.

Therefore, as in the prior art, the beam is reduced while passing through the cylinder lens and then passed through the beam converting unit, thereby fundamentally preventing the loss of light quantity.

That is, in the present invention, since the beam is not contracted while passing through the front end spherical lens array 410, there is no need for an apparatus for re-enlarging the beam as in the prior art, the same effect can be achieved by a simple configuration. have the advantage of being there.

On the other hand, the partial beam divided while passing through the front end spherical lens array 410 is rotated while passing through the beam converting means (420).

That is, the diffraction index of the partial beam after passing through the beam converting means 420 is Mx ² = 14, My ² = 2, and the diffraction index of the entire beam b4 has Mx ² = 98, My ² = 2 do.

This partial beam passes through the spherical lens array 430 and is formed into a line beam shape b4.

10 is a view showing a uniaxial beam diameter adjusting optical system in the present invention.

The uniaxial beam diameter control optical system 500 is a zoom optical system, and in this embodiment, four groups of lenses are made, and each group of lenses is made of a cylinder lens.

The first group of lenses 510 on the left side of the incident direction and the fourth group of lenses 540 on the rear side are installed between the first group of lenses 510 and the fourth group of lenses 540 in a fixed state. The second group of lenses 520 and the third group of lenses 530 are configured to move non-linearly according to the zoom trajectory.

The uniaxial beam diameter control optical system 500 had a zoom magnification of 1.5 to 2.4 times. That is, the beam emitted from the beam converter 400 at 5 mm is enlarged only in the direction of the short axis from 7.5 mm to the maximum of 12 mm using a cylinder lens, and the diameter of the beam incident to the single axis imaging optical system is adjusted to adjust the NA (Numeric Aperture. Aperture). number) while changing the size of the short-axis spot.

11 is a diagram showing a long-axis optical system in the present invention.

The long-axis optical system 600 includes a fly-eye lens unit 610 (Fly Eye Lens) and a long-axis projection imaging optical system 620 .

The fly's eye lens unit 610 is a well-known configuration and is formed so that two lenses are disposed to face each other, and acts to equalize the long-axis beam to equalize the brightness.

The long-axis projection imaging optical system 620 is typically configured as a fixed-focus optical system, but in this embodiment, it is configured as a zoom lens so that the length of the long-axis can be adjusted by ±10% from the desired length.

That is, the long-axis projection imaging optical system 620 is composed of three groups of lenses in this embodiment, and each group of lenses is composed of a cylinder lens.

A first group of lenses 621, a second group of lenses 622, and a third group of lenses 623 are sequentially installed on the left side of the incident direction, and in a state in which the third group of lenses 623 is fixed The first group of lenses 621 and the second group of lenses 622 are configured to move non-linearly according to the zoom trajectory.

By configuring the long-axis projection imaging optical system 620 as a zoom optical system, the length in the long-axis direction can be continuously adjusted.

12 is a diagram showing a single-axis projection imaging optical system in the present invention.

In the single-axis projection imaging optical system 700 , four groups of lenses 710 , 720 , 730 , and 740 are sequentially installed in the incident direction.

When the lenses of the second group (720, usually referred to as a variator) move in a straight line while the first group of lenses 710 and the fourth group of lenses 740 are fixed, the third group of lenses 730 (normally) The compensator (called Compansator) is configured to move non-linearly according to the zoom trajectory.

The single-axis projection imaging optical system 700 is designed as a zoom lens whose focal length varies from 300 mm (NA 0.02) to 600 mm (NA 0.01) for an incident beam of 12 mm so that the line width in the short axis direction can be adjusted.

For reference, the spot size and depth of focus of the laser optical system are determined by the following formula

Spot size = ( 2 / π ) * ( λ / NA ) * M²

Depth = ( 2 / π ) * ( λ / NA² ) * M²

= spot size / NA

where λ: wavelength, NA: numerical aperture, M: diffraction

The operation of the present invention is summarized as follows.

In the present invention, the beam emitted from the light source 100 is adjusted to a constant diameter by the beam diameter adjustment optical system 200 made of the zoom lens optical system, and then the optical path is separated by the speckle reduction unit 220 to exceed the possible interference distance. It is delayed and emitted with reduced speckle.

Next, a line beam having a small size of a spot focused in the y-axis direction is formed by the beam converting unit 400 after being expanded from a circular beam to an ellipse by the beam expanding unit 300 .

Then, it acts to enlarge the diameter of the beam in the short axis direction by the short axis beam diameter control optical system 500 made of the zoom lens optical system.

On the other hand, the beam emitted from the short-axis beam diameter control optical system 500 passes through the fly-eye lens unit 610 of the long-axis optical system 600, the brightness of the long-axis beam is uniform, and then the long-axis projection imaging optical system 620 comprising a zoom lens optical system. ), the length of the long axis of the beam is adjusted.

Next, while passing through the uniaxial projection imaging optical system 700 composed of the zoom lens optical system, it functions to adjust the line width in the short axis direction.

The embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

100: light source 200: beam delivery optical system
300: beam expanding unit 400: beam converting unit
500: short-axis beam diameter control unit 600: long-axis optical system
700: single-axis optical system

Claims (9)

a light source emitting a beam, and
a beam expanding unit for expanding the beam emitted by the light source;
It consists of a beam converting unit for converting the expanded beam by the beam expanding unit,
The beam expander,
a spherical lens installed at the rear end of the light source;
and a pair of cylinder lenses installed at the rear end of the spherical lens. The method according to claim 1,
The beam converter,
a front-end spherical lens array installed at the rear end of the pair of cylinder lenses and connected to a plurality of spherical lenses with cut end surfaces;
a beam converting means array installed at the rear end of the front end spherical lens array and comprising a plurality of beam converting means installed in correspondence with each of a plurality of spherical lenses to rotate a partial beam;
and a rear end spherical lens array installed at the rear end of the beam converting means and connected to a plurality of spherical lenses with cut end surfaces. 3. The method according to claim 2,
Each of the beam conversion means consists of a combination of a plurality of prisms or a combination of mirrors or a combination of prisms and mirrors so that the incident partial beam is rotated and output is vertically inverted,
The line beam forming apparatus according to claim 1, wherein each of the beam converting means is obliquely disposed on an xy plane horizontal to the beam traveling direction (z direction) and arranged in a line in the vertical direction. 4. The method of claim 3,
Each of the beam converting means consists of two first and second mirrors formed at a symmetrical angle to each other when viewed from the front and arranged to form an apex downward, and a third mirror arranged horizontally under the apex,
Line beam forming apparatus, characterized in that the first and second reflective surfaces are formed on the outside of the first and second mirrors, respectively, and the third reflective surface is formed on the upper surface of the third mirror. 5. The method of claim 4,
A beam transmission optical system is installed between the light source and the beam expander,
The beam delivery optical system includes a beam diameter control optical system,
The beam diameter adjusting optical system is a line beam forming apparatus, characterized in that the non-focus zoom lens optical system for constantly adjusting the diameter of the beam emitted from the light source. 5. The method of claim 4,
The beam delivery optical system includes a speckle reduction unit disposed behind the beam diameter control optical system,
The speckle reduction unit,
an upper prism and a lower prism installed under the upper prism;
It is installed between the upper prism and the lower prism and consists of two beam splitters disposed to face each other,
The transmission reflectance of the two beam splitters is determined such that the delay distance of the light source is greater than the interference possible distance of the light source. 7. The method of claim 6,
A single axis beam diameter control optical system is installed behind the beam converting means,
The uniaxial beam diameter adjusting optical system is formed as a non-focus zoom optical system to enlarge the diameter of the beam in the uniaxial direction emitted from the beam converting means. 5. The method of claim 4,
A long-axis optical system is installed at the rear of the short-axis beam diameter control optical system,
The long-axis optical system is disposed opposite to each other, and a fly-eye lens unit for equalizing the brightness of the long-axis beam;
A line beam forming apparatus, which is disposed at the rear of the fly's eye lens unit and includes a long-axis projection imaging optical system for adjusting the length of the long-axis by a zoom optical system. 5. The method of claim 4,
A short-axis projection imaging optical system is installed behind the long-axis optical system,
The uniaxial projection imaging optical system is a line beam forming apparatus, characterized in that it is formed as a zoom lens optical system to adjust the line width in the uniaxial direction.

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