KR100864017B1 - Line beam generator - Google Patents

Abstract

A line beam generator is provided to reduce speckles due to interferences between beams by reducing a length of an optical system using a multiple reflective mirror scheme and a pumping scheme. A line beam generator includes a semi-transparent mirror(1140), a total reflection mirror(1130), a medium portion(940), and a passing point(970). The semi-transparent mirror partially reflects the light, which is received from a light source and the total reflection mirror, such that passed beams form a linear beam. The total reflection mirror reflects the beam, which is reflected on the semi-transparent mirror, toward the semi-transparent mirror. The medium portion includes a low reflection coating layer and a high transmissive coating layer. The high transmissive coating layer passes a harmonics laser, which is formed by the beam from the semi-transparent mirror. The medium portion changes a frequency of the passed beam to form the harmonics laser. The passing point has a predetermined curvature, such that the harmonics laser passes through the passing point.

Description

Line Beam Generator

1 is a block diagram of a display apparatus using a line beam generator according to a preferred embodiment of the present invention.

2A is a perspective view of one type of diffractive light modulator module using a piezoelectric body applicable to a preferred embodiment of the present invention.

2B is a perspective view of another type of diffractive light modulator module using a piezoelectric body applicable to a preferred embodiment of the present invention.

2C is a plan view of a diffractive light modulator array applicable to a preferred embodiment of the present invention.

FIG. 2D is a schematic diagram in which an image is generated on a screen by a diffractive light modulator array applicable to a preferred embodiment of the present invention. FIG.

3 is a configuration diagram of a line beam generator using a multiple reflection mirror method according to an embodiment of the present invention.

4 is a configuration diagram of a line beam generator using a multiple reflection mirror method according to another embodiment of the present invention.

5 is a uniformity profile of the line beam generated by the line beam generation apparatus using a multiple reflection mirror method according to an embodiment of the present invention.

6 is a diagram illustrating a continuous transmittance of a transflective mirror of the line beam generator using a multiple reflection mirror method according to an embodiment of the present invention.

7 is a diagram illustrating discontinuous transmittance of a transflective mirror of a line beam generator using a multiple reflection mirror according to an embodiment of the present invention.

8 is a diagram illustrating beam intensity according to reflectance and transmittance of a line beam generator using a multiple reflection mirror method according to an exemplary embodiment of the present invention.

9 is a view showing a line beam generator using a harmonic laser according to an embodiment of the present invention.

10 illustrates a line beam generator using a harmonic laser according to another embodiment of the present invention.

11 is a view showing a line beam generator using a multiple reflection mirror method and a harmonic laser according to an embodiment of the present invention.

12 illustrates a line beam generator using a multiple reflection mirror method and a harmonic laser according to another embodiment of the present invention.

The present invention relates to a line beam generator, and more particularly, to a line beam generator using a multiple reflection mirror system and a harmonic laser.

According to the prior art, there are various methods for making a line beam. Some of the typical examples include a truncation method, an aspherical lens such as a truncation method, a Powell lens, a HOE or Flat-top method to uniformize beam using DOE element, method of arranging optical fiber properly by dividing beam into several using optical fiber, method of arranging light source in one dimension, FEL There are various methods such as a lens array method.

However, the truncation method has a disadvantage in that it cannot raise both at the same time because there is a trade-off relationship in which the efficiency is lowered to increase the uniformity and the uniformity is lowered to increase the efficiency. In addition, the flat top method using aspherical lens such as Powell lens is not easy to manufacture the lens, and the distance between lenses should be secured over a certain distance, and it is sensitive to the width of the incident beam or the degree of collimation. This is not easy.

In addition, the HOE or DOE device is inferior in fabrication performance and efficiency, and the exit angles of the emitted beams are not parallel to each other, so that the uniformity is inferior when the designed distance is out of range. The method using optical fiber is not suitable for the line illumination with small etendue because the etendue is increased after passing through the optical fiber. Here, etendue is an important acquisition size in geometric optics and refers to the beam thickness. The beam thickness is determined by the planar area of the light source and the spatial angle at which the light source emits. In addition, a method of arranging light sources in one dimension or a method such as FEL has a problem in that an optical system is complicated and a light path is long.

In addition, conventionally, harmonic lasers are generated by using separate nonlinear crystals for each laser diode to generate a line beam for displaying an image. And the line beam was formed by arranging a harmonic laser generator.

According to the prior art, the laser diode pumped second harmonic oscillator is a very useful light source for high density magneto-optical recording. In particular, the second harmonic generator in which the nonlinear single crystal for frequency doubling is provided in the internal resonator is one of laser devices having inherent characteristics that the amplitude of the output laser is unstable. For this reason, many studies on the method and stabilization of the second harmonic oscillation have been conducted, and a number of results have been proposed.

Many techniques for achieving effective second harmonic oscillation at relatively low power have been proposed. The laser resonator uses a pair of mirrors coated with a material with high reflectivity for fundamental waves. In this method, an effective second harmonic oscillation can be obtained with minimal loss when a nonlinear single crystal material for frequency doubling is placed inside a resonator through which high intensity fundamental waves are circulated.

However, according to this method, it is difficult to control the warpage phenomenon or the uniformity of light distribution. In addition, according to the arrangement of the plurality of harmonic laser generators, the distance between the laser diode chips is further than necessary, and as a result, the overall size of the optical system can be increased. In addition, the conventional method of doubling the frequency of the laser by the external resonator was used, but by using the external resonator could be less efficient in terms of the output of the laser.

The present invention provides a line beam generator that is easy to adjust and secure uniformity because the optical system is not simple and sensitive.

In addition, the present invention can shorten the optical system length compared to the conventional method, and by generating a line beam that can reduce the speckle as a result of combining a number of non-interfering light by increasing the distance difference between the reflected light than the interference distance of the light source Provide the device.

In addition, the present invention provides a line beam generator that can prevent the line beam from bending, and ensure uniformity of light distribution.

Technical problems other than the present invention will be easily understood through the following description.

According to an aspect of the present invention, there is provided a line beam generating apparatus comprising: a semi-transmissive mirror which reflects and partially transmits a part of light incident from a light source and a total reflection mirror, and allows the transmitted light to form a line beam; A total reflection mirror that reflects light reflected from the transflective mirror toward the transflective mirror; A low reflection coating layer is formed on one surface of the transmitted light emitted from the transflective mirror, and a high transmission coating layer is formed on the other surface to transmit a high reflection coating layer and a harmonic laser formed from the transmitted light on the other surface to change the frequency of the transmitted light. A medium portion for changing to generate a harmonic laser; And a transmission point having a predetermined curvature through which the harmonic laser beam is transmitted, and a line beam generator including a transmission part in contact with the medium part.

Here, the light incident from the light source may be incident at an acute angle to the transflective mirror.

The transflective mirror and the total reflection mirror may be parallel to each other.

Here, the transflective mirror has a continuous transmittance, and the line beam formed through the transflective mirror may have the same intensity according to the position.

Here, the continuous transmittance may increase as the distance from the first incident light from the light source is incident.

Here, the transflective mirror has a discontinuous transmittance, and the line beam formed through the transflective mirror may have the same intensity according to the position.

Here, the discontinuous transmittance may increase as the distance from the first incident light from the light source is incident.

Here, the harmonic laser may be a second harmonic pile.

Here, the medium portion may be a nonlinear crystal.

Here, the nonlinear crystal may be either PPLN (Periodically Poled LiNbO ₃ ) or crystallization.

Here, the harmonic laser may be green light.

Here, the predetermined curvature of the transmission point may be caused by thermal expansion due to the laser light is reflected at the transmission point.

According to another aspect of the present invention, there is provided a line beam generator, comprising: a semi-transmissive mirror for reflecting and partially transmitting a part of light incident from a light source and a total reflection mirror, and allowing the transmitted light to form a line beam; A total reflection mirror that reflects light reflected from the transflective mirror toward the transflective mirror; A first medium part on which one side of the total reflection mirror is located, and the other side of the transflective mirror, and the light projected from the light source and the reflected light travel; A low reflection coating layer is formed on one surface of the transmitted light emitted from the transflective mirror, and a high transmission coating layer is formed on the other surface to transmit a high reflection coating layer and a harmonic laser formed from the transmitted light on the other surface to change the frequency of the transmitted light. A second medium portion to change to produce a harmonic laser; And a transmission point having a predetermined curvature through which the harmonic laser beam is transmitted, and a line beam generating device including a harmonic laser transmission part contacting the second medium part.

The incident light transmitting part may further include an incident light transmitting part that transmits light incident from the light source and is disposed on one surface of the medium part in which the total reflection mirror is located.

Here, the light incident from the light source may be incident at an acute angle to the transflective mirror.

The transflective mirror and the total reflection mirror may be parallel to each other.

Here, the transflective mirror has a continuous transmittance, and the line beam formed through the transflective mirror may have the same intensity according to the position.

Here, the continuous transmittance may increase as the distance from the first incident light from the light source is incident.

Here, the transflective mirror has a discontinuous transmittance, and the line beam formed through the transflective mirror may have the same intensity according to the position.

Here, the discontinuous transmittance may increase as the distance from the first incident light from the light source is incident.

Here, the harmonic laser may be a second harmonic pile.

Here, the medium portion may be a nonlinear crystal.

Here, the nonlinear crystal may be any one of PPLN (Periodically Poled LiNbO ₃ ) or a crystal.

Here, the harmonic laser may be green light.

Here, the predetermined curvature of the transmission point may be generated by thermal expansion due to the laser light is reflected at the transmission point.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In addition, in the description with reference to the accompanying drawings, the same components regardless of reference numerals will be given the same reference numerals and duplicate description thereof will be omitted. In the following description of the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, embodiments of the present invention can be applied in combination with a MEMS package for transmitting a signal to or receiving a signal from the outside in general, MEMS applied to the present invention before explaining the preferred embodiments of the present invention in detail An optical modulator in a package and a display system using the same will be described first.

1 is a block diagram of a display apparatus using a line beam generator according to a preferred embodiment of the present invention. The display device includes a line beam generator 110 as a light source, an illumination optical system 120, a light modulator 130, a relay optical system 140, a scanning mirror 150, and a projection optical system 160. , The imaging surface 170 and the image controller 180.

The line beam generator 110 is a device for generating light, and a light emitting diode (LED), a laser diode (LD), or a laser may be used for the line beam generator. Hereinafter, for convenience of description, a case where the line beam generator using the laser diode serves as a light source will be described as an example. According to the exemplary embodiment of the present invention, a line beam generator 110 capable of providing a line beam to a display device may be provided.

The line beam emitted from the line beam generator 110 is reflected or distributed at a predetermined angle by the illumination optical system 120 to be irradiated to the light modulator 130. The light modulator 130 generates diffracted light by modulating the incident light according to the image control signal received from the image controller 180. Thereafter, the generated diffracted light is transmitted to the scanning mirror 150 via the relay optical system 140. The scanning mirror 150 rotates at a predetermined angle according to the mirror control signal received from the image controller 180 and projects the diffracted light onto the imaging surface 170 using the projection optical system 160.

The projection optical system 160 is an optical system for expanding and projecting the generated diffracted light on the imaging surface 170.

In addition, the illumination optical system 120 may include a collimator lens and a cylinder lens. The collimator lens and the cylinder lens change the incident light into linear parallel light. That is, the collimator lens converts the focused multi-beam into linear light in the horizontal direction with respect to the optical path direction and enters the optical modulator 130 through the polarization beam splitter, the λ / 4 wave plate, and the X-prism. The collimator lens may have a concave lens and a convex lens. The concave lens extends linear light incident from the cylinder lens and enters the convex lens. The convex lens emits incident light incident from the concave lens into parallel light. Here, the cylinder lens converts parallel light into linear light in the horizontal direction so as to horizontally incident light incident from the condenser to the corresponding light modulator 130 positioned horizontally in the optical path direction, thereby converting the corresponding collimator lens. Through the light modulator 130 is incident.

Here, the optical modulator can be divided into a direct method of controlling direct on / off of light and an indirect method using reflection and diffraction, and the indirect method may be divided into an electrostatic method and a piezoelectric method. Herein, the optical modulator is applicable to the present invention regardless of the manner in which the optical modulator is driven.

Conventional electrostatically driven grating light modulators include a plurality of regularly spaced deformable reflective ribbons having reflective surface portions and suspended above a substrate.

First, an insulating layer is deposited on a silicon substrate, followed by a deposition process of a sacrificial silicon dioxide film and a silicon nitride film. The silicon nitride film is patterned with a ribbon and a portion of the silicon dioxide layer is etched so that the ribbon is held on the oxide spacer layer by the nitride frame. To modulate light with a single wavelength [lambda] 0, the modulator is designed so that the thickness of the ribbon and the thickness of the oxide spacers are [lambda] 0/4.

The lattice amplitude of this modulator, defined by the vertical distance d between the reflective surface on the ribbon and the reflective surface of the substrate, is the conduction of the ribbon (reflective surface of the ribbon serving as the first electrode) and the substrate (substrate serving as the second electrode). Film).

Figure 2a is a perspective view of one type of diffractive light modulator module using a piezoelectric of the indirect light modulator applicable to the present invention, Figure 2b is another type of diffractive light modulator module using a piezoelectric applicable to a preferred embodiment of the present invention Perspective view. 2A and 2B, an optical modulator including a substrate 210, an insulating layer 220, a sacrificial layer 230, a ribbon structure 240, and a piezoelectric material 250 is shown.

The substrate 210 is a commonly used semiconductor substrate, and the insulating layer 220 is deposited as an etch stop layer, and an etchant for etching a material used as a sacrificial layer, where the etchant is an etching gas or an etching solution. Solution). The reflective layers 220 (a) and 220 (b) may be formed on the insulating layer 220 to reflect incident light.

The sacrificial layer 230 supports the ribbon structure 240 at both sides so as to be spaced apart from the insulating layer 220 at regular intervals, and forms a space at the center.

As described above, the ribbon structure 240 causes diffraction and interference of incident light to optically modulate the signal. The shape of the ribbon structure 240 may be configured in the form of a plurality of ribbons according to the electrostatic method as described above, or may be provided with a plurality of open holes in the center of the ribbon according to the piezoelectric method. In addition, the piezoelectric member 250 controls the ribbon structure 240 to move up and down in accordance with the degree of contraction or expansion of up and down or left and right caused by the voltage difference between the upper and lower electrodes. Here, the reflective layers 220 (a) and 220 (b) are formed to correspond to the holes 240 (b) and 240 (d) formed in the ribbon structure 240.

For example, when the wavelength of light is λ, no voltage is applied or a predetermined voltage is applied to the upper reflective layers 240 (a) and 240 (c) and the lower reflective layer 220 (a) formed on the ribbon structure. ), The gap between the insulating layers 220 on which 220 (b) is formed is equal to nλ / 2 (n is a natural number). Therefore, in the case of the zero-order diffracted light (reflected light), the total path difference between the light reflected from the upper reflective layers 240 (a) and 240 (c) formed on the ribbon structure and the light reflected from the insulating layer 220 is equal to nλ, which is reinforced. By interfering, the diffracted light has maximum brightness. Here, in the case of + 1st and -1st diffraction light, the brightness of light has a minimum value due to destructive interference.

In addition, when an appropriate voltage different from the applied voltage is applied to the piezoelectric member 250, the upper reflective layers 240 (a) and 240 (c) and the lower reflective layers 220 (a) and 220 (b) formed on the ribbon structure. The gap between the insulating layers 220 on which? Is formed is equal to (2n + 1) λ / 4 (n is a natural number). Therefore, in the case of zero-order diffracted light (reflected light), the total path difference between the upper reflective layers 240 (a) and 240 (c) formed on the ribbon structure and the light reflected from the insulating layer 220 is (2n + 1) λ / 2. As shown in FIG. 8, the diffracted light has minimum luminance due to destructive interference. In the case of the + 1st and -1st diffracted light, the luminance of light has a maximum value due to constructive interference. As a result of this interference, the light modulator can adjust the amount of reflected or diffracted light to carry the signal on the light.

In the above, the case in which the distance between the ribbon structure 240 and the insulating layer 220 on which the lower reflective layers 220 (a) and 220 (b) are formed is nλ / 2 or (2n + 1) λ / 4 has been described. Naturally, various embodiments that can be driven at intervals that can adjust the intensity interfered by the diffraction and reflection of incident light can be applied to the present invention.

Hereinafter, the optical modulator of the type shown in FIG. 2A will be described.

Referring to FIG. 2C, the optical modulator includes a first pixel (pixel # 1), a second pixel (pixel # 2),. And m micromirrors 100-1, 100-2,..., 100-m that are responsible for the m-th pixel (pixel #m). The optical modulator is responsible for the image information of the one-dimensional image of the vertical scanning line or the horizontal scanning line (assuming that the vertical scanning line or the horizontal scanning line is composed of m pixels), and each micromirror 100-1, 100-2. , ..., 100-m) is in charge of any one of m pixels constituting the vertical scan line or the horizontal scan line. Thus, the light reflected and diffracted by each of the micromirrors 100-1, 100-2, ..., 100-m is then projected on the screen by a light scanning device as a two-dimensional image. For example, in the case of VGA 640 * 480 resolution, 640 modulations are performed on one side of an optical scanning device (not shown) for 480 vertical pixels, thereby generating one frame of one screen per side of the optical scanning device. The optical scanning device may be a polygon mirror, a rotating bar, a galvano mirror, or the like.

Hereinafter, the principle of light modulation will be described based on the first pixel (pixel # 1), but the same may be applied to other pixels.

In the present embodiment, it is assumed that there are two holes 240 (b) -1 formed in the ribbon structure 240. Due to the two holes 240 (b)-1, three upper reflective layers 240 (a)-1 are formed on the ribbon structure 240. Two lower reflective layers are formed in the insulating layer 220 corresponding to the two holes 240 (b)-1. In addition, another lower reflective layer is formed on the insulating layer 220 corresponding to the portion of the gap between the first pixel (pixel # 1) and the second pixel (pixel # 2). Accordingly, the number of upper reflective layers 240 (a) -1 and lower reflective layers driven by the piezoelectric body 250-1 per pixel is the same, and as described above with reference to FIG. 2A, zero-order diffracted light or ± It is possible to adjust the brightness of the modulated light using the first order diffracted light.

Referring to FIG. 2D, there is shown a schematic diagram in which an image is generated on a screen by a diffractive light modulator array applicable to a preferred embodiment of the present invention.

Light reflected and diffracted by the m micromirrors 100-1, 100-2,..., 100-m arranged vertically is reflected by the optical scanning device, and is generated by scanning the screen 270 horizontally. 280-1, 280-2, 280-3, 280-4, ..., 280- (k-3), 280- (k-2), 280- (k-1), 280-k) are shown. When rotated once in the optical scanning device, one image frame may be projected. Here, the scanning direction is shown in a left to right direction (arrow direction), but it is obvious that the image may be scanned in another direction (for example, the reverse direction).

The display apparatus to which the present invention is applied has been described above. Hereinafter, with reference to the accompanying drawings, a line beam generating apparatus using a multiple reflection mirror method and a pumping method according to the present invention will be described with reference to specific embodiments. do. The embodiment according to the present invention is divided into two embodiments using a multiple reflection mirror method and two embodiments using a pumping method, and may be a line beam generator having a mixed type, which will be described in order below.

An object of the present invention is to generate a line-type green light source by a line-type pumping light by making a line beam consisting of a plurality of beams through a multi-reflective mirror with one pumping light source. One way to reduce speckle on the display is to The use of a light source reduces coherence, and as part of this, speckle can be reduced by reducing the coherence between multiple beams formed through a multi-reflective mirror, although it is a beam from one light source. Degrading the coherence means that the divided beams are made of different light sources. To do this, the beam path difference between the beams is longer than the coherence distance. Here, the coherence distance (lc) is expressed as the wavelength and line width of the pumping light source.

When the beam path difference (distance difference between the reflected light) in the multi-reflection mirror is longer than the coherence distance, the coherence of various pumping light sources formed by the multi-reflection mirror disappears and thus the mutual difference between the laser light sources generated by the SHG method is eliminated. Coherence also disappears, providing a line beam generator capable of reducing speckle.

3 is a configuration diagram of a line beam generator using a multiple reflection mirror method according to an embodiment of the present invention. Referring to FIG. 3, the light 310 incident from the light source, the line beam 320, the total reflection mirror 330, and the transflective mirror 340 are shown.

Part of the light 310 incident from the light source is reflected by the transflective mirror 340 positioned to form an acute angle with the traveling direction, and the other part is transmitted. Since the normal of the plane formed by the transflective mirror 340 is not parallel to the advancing direction of the light 310 incident from the light source, part is transmitted to form part of the line beam 320, and the rest is reflected to total reflection Facing the mirror 330. That is, the individual transmitted light transmitted through the transflective mirror 340 forms the line beam 320.

The light reflected by the total reflection mirror 330 is partially reflected by the transflective mirror 340 and the other part T1 is transmitted, similar to the light 310 incident from the light source. As this process is repeated, the transmitted light (T1, T2, ..., TN) forms a line beam. The number of reflections and transmissions of light may be adjusted according to the length and intensity of the preset line beam 320.

Here, the total reflection mirror 330 and the semi-transmissive mirror 340 may be parallel to each other, in addition to the coupling structure capable of forming the transmitted light (T1, T2, ..., TN) can be applied to the present invention. In addition, the total reflection mirror 330 and the semi-transmissive mirror 340 may be implemented without being limited to the coupling relationship or structure, as long as the above-described mirror 340 performs the function as described above. For example, the total reflection mirror 330 and the transflective mirror 340 may be fixed to be spaced apart by a predetermined distance by combining at the edge (edge) of each other.
In addition, when the light is reflected several times between the total reflection mirror 330 and the semi-transmissive mirror 340, the light intensity may be reduced because the amount is lost by absorption. In this case, the line beam 320 is not uniform, and the intensity may vary depending on its position. The transflective mirror 340 has a continuously varying transmittance, and the line beam formed through the transflective mirror 340 may have the same intensity according to the position, that is, have a uniform intensity. For example, the transmittance of the transflective mirror 340 may increase as the distance from the portion of the transflective mirror 340 to which the first incident light from the light source is incident. This change in transmittance may be set continuously or discontinuously. In the case where the transmittance change of the transflective mirror 340 is continuous and discontinuous, the line beam formed through the transflective mirror 340 may have a uniform intensity according to the position. This will be described later with reference to FIG. 4.

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4 is a block diagram of a line beam generator using a multiple reflection mirror method according to another embodiment of the present invention. Referring to FIG. 4, the light 410 incident from the light source, the line beam 420, the transmission part 425, the medium part 427, the total reflection mirror 430, and the transflective mirror 440 are shown. Hereinafter, the differences from those described above with reference to FIG. 4 will be mainly described.

The transmissive portion 425 (which may be referred to as incident light transmissive portion to distinguish it from the harmonic laser transmissive portion described below), the media portion 427, the total reflection mirror 430, and the transflective mirror 440 form one flat plate. That is, the transmissive part 425 and the total reflection mirror 430 are located on one surface of the medium part 427, and the transflective mirror 440 is located on the other surface of the medium part 427. The light 410 incident from the light source is incident on the transmissive part 425 and then partially reflected by the transflective mirror 340 through the medium part 427 and the remaining part is transmitted. Since the transmissive part 425, the medium part 427, the total reflection mirror 430, and the transflective mirror 440 form one flat plate, the transmissive part 425, the medium reflection part 427, and the transflective mirror 440 are easy to manage integrally and convenient to commercialize.

In this case, the transparent plate 425 may be omitted. That is, the light 410 incident from the light source may be directly incident to the medium portion 427 without passing through the transmission portion 425. That is, the transmission part 425 can be attached as needed. For example, the transmissive portion 425 may be provided adjacent to the total reflection mirror 430 to protect the medium portion 427.

Here, the length of the line beam 420 is L, the distance between adjacent points where the reflected light is reflected by the total reflection mirror 430 is p, and the distance between the total reflection mirror 430 and the transflective mirror 440 is d. In addition, the refractive angle Θm corresponding to the incident angle Θi of the light 410 incident from the light source is determined according to the refractive index of the medium portion 427, thereby changing the optical path in the medium portion 427. have.

The operating principle of the line beam generator using the multiple reflection mirror method according to an embodiment of the present invention is as follows. Set d and Θi to satisfy the following conditions.

2 * d * sec (Θm)> λ2 / Δλ (1)

n * sin (Θm) = sin (Θi) (2)

p = 2 * d * tan (Θm) (3)

L = (N-1) * α (4)

α = p * cos (Θi) (5)

Is the wavelength of light in the medium portion 427, and λ is the line width. In addition, n is the refractive index of the medium portion 427, N is the number of individual transmitted light, L is the length of the line beam.

The reflectance of the total reflection mirror 430 is called r ₁ , and the reflectance of the transflective mirror 440 is called r _AR . In addition, the transmittance according to the position of the transflective mirror 440 is t ₁ , t ₂ , t ₃ ,. It is referred to as t _N , and the light loss generated when light propagates between the total reflection mirror 430 and the transflective mirror 440 is called a.

When the light incident from a light source having a beam intensity of 1 is transmitted through the transmissive part 425 having a high transmittance t _AR in the total reflection mirror plane, the beam intensity P1 transmitted through the transflective mirror 440 having a transmittance t ₁ is assumed. The following equation holds.

P ₁ = t _AR * t ₁ (6)

The beam reflected from the transflective mirror 440 surface reaches the beam intensity 1-P ₁ -a on the total reflection mirror 430 surface having the reflectance r ₁ , and the beam intensity is r ₁ * (1-P ₁ -a). It has been reflected, if the intensity of the transmitted beam in the transmittance the semi-transmission mirror 440 faces the second position having a t ₂ P ₂ referred to the following expression is satisfied with the same.

P ₂ = t ₂ * r ₁ * (1- P ₁ -a) (7)

Reflect with a beam intensity of r ₁ * (1-t _AR * t ₁ -a) * (1-t ₂ -a) on the side of the transflective mirror 440 to reflect the second reflection (r1) on the side of the total reflection mirror 430 When the intensity of the transmitted beam at the third transmission position of the transflective mirror 440 having a transmittance t ₃ is P ₃ , the following equation is established.

P ₃ = r ₁ ² * (1- t _AR * t ₁ -a) * (1-t ₂ -a) * t ₃ (8)

Similarly, when the transmittance of the N th beam bundle is P _N , the following equation is established.

P _N = r ₁ * P _{N- 1} * (1-t _{N -1} -a) * t _N / t _{N -1} (9)

Therefore, P ₁ = P ₂ = P ₃ =... So that the line beam transmitted through the transflective mirror 440 becomes uniform light. . The reflectance conditions at each position of the transflective mirror 440 to be P _N are as follows.

t _N = 1 / r ₁ * t _{N- 1} / (1-t _{N -1} -a) (10)

t ₂ = t _AR * t ₁ / {r ₁ * (1- t _AR * t ₁ -a)} (11)
Equations 10 and 11 represent the transmittance conditions at each position of the transflective mirror 440 for the line beam transmitted through the transflective mirror 440 to become uniform light. Therefore, the transmissivity of the transflective mirror 440 by position satisfies the above equations 10 and 11, and the transflective mirror 440 is both a case where the transmissivity change of the transflective mirror 440 is continuous and discontinuous. The light passing through) may be uniform light having the same intensity for each position.

An example showing the transmittance function with N = 23 is described in FIG. 8.

In addition, the period α [= p * cos (Θi)] between the individual transmitted light passing through the transflective mirror 440 is the center of the beam intensity (I (r)) of the beam at the position where the beam diameter of the collimated beam r r = 0) is determined by the beamwidth Φ being 1 / e2 relative to the intensity and the required longitudinal beam uniformity U. The incident light beam distribution function I (r) and the transmitted light beam intensity distribution function I _tr (y) are as follows.

,

,

(12)

(12)

For example, if the beam width Φ is 1.6 (σ = 0.4) and the period α between the individual transmitted lights is 1.6 * σ, the beam uniformity becomes 99%. As such, the beam uniformity and the transmission beam bundle period α are adjusted to the required degree of beam uniformity, and the beam bundle number N is determined by l = (N−1) * α to match the required beam length l.

The distance d between the total reflection mirror 430 and the transflective mirror 440 is determined by λ, Δλ, and incidence angle Θi of the light source used in Equations (1) and (2) described above.

The period? Between the individual transmitted light beams passing through the transflective mirror 440 is determined by the incident angle Θ i and the distance d between the reflection mirrors by the following expression.

=

(13)=

(13)

In the same manner as above, the beam emitted to maintain uniformity in the y-axis direction may be converged by the y-cylinder lens having the curvature around the y-axis to make the beam narrow in the x-axis direction, thereby forming a narrow and long line beam.

Therefore, the speckle can be reduced as a result of combining a plurality of non-interfering light by making the distance difference between the reflected light longer than the interference distance of the light source.

5 is a uniformity profile of the line beam generated by the line beam generator using the multiple reflection mirror method according to an embodiment of the present invention.

Referring to FIG. 5, a profile of a line beam is formed in which the individual transmitted lights 510 and 520 passing through the above-mentioned translucent mirror overlap each other. When the maximum intensity of the individual transmitted light 510 and 520 is represented by 100%, the maximum intensity of the intermediate region formed to overlap each other is represented by U%. In addition, the intensity of the other individual transmitted light 520 formed at the maximum intensity of the individual transmitted light 510 is 13.5%. The distance between the portions representing the maximum intensity of the individual transmitted light 510, 520 is α, and the effective width φ of the individual transmitted light 510 is represented by 4σ.

By adjusting the distance between the above-mentioned semi-transmissive mirror and the total reflection mirror, α can be controlled, and therefore, uniformity of the line beam can be controlled.

6 and 7 are diagrams illustrating continuous transmittance and discontinuous transmittance of the transflective mirror of the line beam generator using the multiple reflection mirror method according to an embodiment of the present invention, respectively. 6 and 7, the horizontal axis represents the number of the individual transmitted light, and the vertical axis represents the transmittance.

When the light incident from the light source is reflected several times between the transflective mirror and the total reflection mirror described above, lost light may be generated, and thus the intensity of the line beam needs to be uniformly ensured. Thus, the transmittance of the transflective mirror can vary depending on its position.

Herein, the transmittance of the transflective mirror may increase as the distance from the first incident light from the light source is incident.

In the case where the transmittance of the transflective mirror is continuous, the transmittance of the transflective mirror can be set so that the intensity of the line beam can be uniformly formed with respect to the overall portion.

In addition, when the transmittance of the transflective mirror is discontinuous, the transmittance may be adjusted by presetting a point at which light is reflected between the transflective mirror and the total reflection mirror and incident on the transflective mirror. For example, when nine individual transmitted lights are generated, the transmittance of the transflective mirror portion where each individual transmitted light is incident can be set as shown in FIG. 7.

8 is a diagram illustrating beam intensity according to reflectance and transmittance of a line beam generator using a multiple reflection mirror method according to an exemplary embodiment of the present invention.

Here, the arrows indicated by the beam bundle numbers 1, 2, 3, and 23 mean that multiple reflections are performed. Loss is multiplied by the loss factor minus the reflectance of the reflecting surface from the power in the media. Loss1 is absorbed while the media is absorbed while the beam is reaching the total reflection mirror. Is the calculated value. Loss2 also takes into account the absorptivity lost as the beam reflected from the total reflection surface passes through the medium, the absorption rate of the partially reflective mirror surface, and the loss ratio of the scattered beam. In other words, it is a value considering that the beam is absorbed while the beam proceeds in the medium. Power in the media refers to the light intensity remaining between the two mirrors.

By varying the transmittance of the second side according to the individual transmitted light (expressed in the beam bundle), the overall output and uniformity of the line beam can be determined constant.

9 illustrates a line beam generator using a harmonic laser according to an embodiment of the present invention.

The line beam generator shown in FIG. 9 is largely a light emitter 910, a medium 940 and a transmissive portion 960 (which may be referred to as a harmonic laser transmissive portion to distinguish it from the transmissive portion located on the side of the total reflection mirror described above). It consists of. The light emitter 910 may emit a plurality of laser lights. The light emitter 960 includes a combination of the base plate 920 and the plurality of laser diode chips 930.

Here, the plurality of laser diode chips 930 may be arranged in a line on the base plate 920 so that a plurality of laser lights emitted from the light emitting unit 910 may form a line beam. The laser light emitted from the light emitter 910 first enters the medium 940. The medium portion 940 may be a nonlinear crystal or a frequency doubling crystal, for example, a material capable of generating a second harmonic. Frequency doubling crystals are incident on the crystals, such as crystals or PPLNs (Periodically Poled LiNbO3). In general, a technology in which harmonic laser is generated by reinforcement of the pumping light 950 due to resonance in the material of the medium 940 is obvious to those of ordinary skill in the art, and thus a detailed description thereof will be provided. Is omitted.

It is known that resonance occurs in the medium portion 940 which is a frequency doubling material. Efficient second harmonic generation can be obtained by repetitive reflection of the pumping light 950. Here, the medium portion 940 may be referred to as a second medium portion to distinguish it from the medium portion (first medium portion) formed between the aforementioned total reflection mirror and the semi-transmissive mirror.

First, the medium portion 940 according to the embodiment of the present invention may be a crystal that doubles the frequency of incident light, that is, makes the wavelength 1/2. An example of such a determination may be an SHG crystal (second harmonic crystal). Examples of such SHG crystals are crystals or PPLN, hereinafter referred to collectively as non-linear crystals. PPLN (Periodically Poled LiNbO3) is a material that provides high-speed wavelength conversion by nonlinear interactions as periodically polarized lithium niobate or lithium niobate. In addition, the third harmonic crystal refers to a crystal that triples the frequency of the incident light or laser. There may also be a fourth harmonic crystal on the same principle. However, in the present specification, the case where the medium portion 940 is the second harmonic crystal among nonlinear crystals will be described. It is obvious, however, that this cannot be interpreted as limiting the scope of the invention.

In addition, in the present specification, frequency doubling and wavelength reduction may be used in the same sense. In other words, doubling the frequency of a laser or the like, halving the wavelength of the laser or the like, doubling the frequency of the laser or the like, or decreasing the wavelength of the laser or the like by 1/3 is used in the same sense. do.

When the frequency of the laser is doubled by the medium portion 940, the pumped light emitted from the light source passes through the nonlinear crystal while a part of the energy is converted into an output of energy corresponding to a specific frequency region.

9 shows a line beam generator according to an embodiment of the present invention. A laser light having a specific wavelength emitted from the light emitting part 910, for example, a laser light having a wavelength of 1064 nm enters into the medium part 940. When the laser light emitted from the light emitter 910 enters the medium portion 940 coated with a material having a high reflectance, such as a coating material having a high reflectance, on both inner walls facing each other, the laser light is optically formed inside the nonlinear crystal 940. Is captured. Here, 'optical capture of laser light' includes a case in which laser light is reflected back and forth through the inner wall of the medium portion 940 without passing through the medium portion 940.

In the embodiment of FIG. 9, in the medium portion 940, a material (coating material) coated on a surface opposite to the light emitting portion 910 is pumped light reciprocating inside the medium portion 940 after the laser light is incident. It has a high reflectance for 950. Therefore, the pumping light 950 is not transmitted to the surface opposite to the light emitting part 910, the frequency is doubled even when the pumping light 950 is output to the outside of the medium portion 940 ( It is output to the outside of the medium portion 940 via a surface opposite to the transmissive portion 960 side instead of the 910 side.

In addition, the material (coating material) coated on the side of the medium portion 940 opposite to the transmissive portion 960 side has a very high transmittance with respect to the wavelength of the pumped light (HT: highly transmissive), and the medium portion 940 ) Has a high reflectance for the wavelength of light (hereinafter referred to as pumping light 950) after being incident on the medium 940 and reflected in the medium portion 940 (HR: highly reflective).

In addition, a material having a high transmittance with respect to the pumping light 950 having a specific frequency on the surface of the medium facing the transmission part 960 and having a high reflectance with respect to the pumping light 950 having a frequency below a specific frequency ( Coating material) is applied. Therefore, the material (coating material) coated on the surface opposite to the transmissive part 960 may transmit only the pumping light 950 having a specific frequency such as twice or three times the frequency of the laser light. The pumping light 950 that does not reach a specific frequency is doubled in frequency while repeating reflection in the medium 940 while being captured in the medium 940.

According to one embodiment of the invention, the surface facing the light emitting portion 910 side in the nonlinear crystal 940 is antireflective (AR) coated for a fundamental wavelength of 1064 nm, thus pumping with a fundamental wavelength of 1064 nm. Light 950 may be incident into the medium portion 940. In addition, the laser light 950 is transmitted at the surface opposite the transmissive portion of the anti-reflective (AR) coated nonlinear crystal 940 for 532 nm when the frequency is multiplied in the medium portion 940.

Here, adjusting the reflectance and the transmittance according to the frequency using a high or low reflection material (coating material) for the laser is already known, and a detailed description thereof will be omitted.

In this embodiment, the medium portion 940 and the transmission portion 960 may be in contact. The harmonic laser 980 of which frequency has been doubled while passing through the medium part 940 is output to the outside through the transmission part 960. Since the size of the optical system is reduced when the medium portion 940 and the transmission portion 960 are in contact with each other as in the present embodiment, the volume of the line beam generator as well as the volume of the display device in which the line beam generator is used can be reduced.

According to another embodiment, although not shown in the drawings, the medium portion 940 and the transmission portion 960 may not be in contact. In this case, the cavity between the medium portion 940 and the transmission portion 960 serves as a resonator.

However, in the embodiment shown in FIG. 9 in which the medium portion 940 and the transmission portion 960 are in contact with each other, the laser light before the wavelength is reduced is absorbed by the medium portion 940, and only the laser light whose wavelength is reduced is the transmission portion. Transmitted through 960. Therefore, compared to the embodiment including the resonator, in the embodiment shown in Figure 9, the medium portion 940 is designed to be long, so that the time for the laser to pass through the medium portion 940 can be long. This is to allow the medium portion 940 to absorb the long wavelength laser more effectively.

In this case, the surface on which the laser is incident on the transmission unit 960 is coated with a material (for example, a coating material) that selectively transmits and reflects the laser according to the wavelength. Such materials are obvious to those of ordinary skill in the art, and detailed description thereof will be omitted.

When the harmonic lasers 980 are output in a line from the transmission unit 960, a line beam may be formed. The transmission part 960 has a transmission point 970 which is a point at which the harmonic laser 980 is output. If necessary, the output surface, ie, the transmission point 970, may employ a curvature to diverge the harmonic laser 980 or output it as parallel light.

Here, the transmission point 970 is a point at which the harmonic laser 980 is transmitted among the transmission parts 960. The transmission point 970 may transmit the harmonic laser 980 by having a predetermined curvature as illustrated in FIG. 9, unlike the region except for the transmission point 970 in the transmission unit 960. By employing the curvature at the transmission point 970, it may be different whether the harmonic laser 980 is emitted in a parallel form or divergent form.

As an embodiment of the method for increasing the curvature of the transmission point 970, there may be a method of having a concave surface than other portions of the transmission portion 960 by supplying heat to the transmission point 970 to thermal expansion. have. According to an exemplary embodiment, the heat source of the transmission point 970 may be the laser light 950 repeatedly reflected on the surface of the medium portion 940 opposite to the transmission point 970.

Through the above-described process, the plurality of harmonic lasers 980 emitted from the transmission point 970 constitute a line beam. That is, the beam output by forming a predetermined line by the plurality of harmonic lasers 980 is called a line beam. The line beam formed at this time may be any one of red light, green light, and blue light. According to an embodiment of the present invention, when the wavelength of the pumped light is 1064 nm, the line beam 980 formed by the line beam generator according to the present embodiment may be green light having a wavelength of 532 nm due to the frequency being doubled.

Here, it may be expected that the uniformity of the line beam or the degree to which the line beam is bent or bent may vary according to the arrangement state of the laser diode chip 930. In this case, if there is an error in the arrangement of the laser diode chip 930, the line beam may be bent or bent. The phenomenon in which the line beam finally formed and radiated through the display device or the like is bent or curved is called a smile effect. In order to eliminate or reduce such a process error, the spacing or alignment of the laser diode chip 930 arranged on the base plate may be modified.

The light emitter 910 (or line beam generator) may be manufactured using a wafer. When the wafer is used, the laser diode chips 930 may be arranged in a line more easily than the process of arranging and arranging the laser diode chips 930 one by one on the base plate 920. That is, when the wafer is used in the manufacturing process of the light emitting part 910, the alignment state of the laser diode chip 930 may be improved, and process error such as a smile effect may be minimized.

When the intensity of the harmonic laser emitted through the line beam generator is assumed to be constant, the uniformity of the line beam may be increased as the interval of the laser diode chip 930 is constant. In addition, the closer the arrangement of the laser diode chip 930 is to a straight line, the more straight the line beam becomes.

Therefore, in the case of generating the line beam according to the present embodiment, the process error is easier than correcting the arrangement of the harmonic lasers emitted from the harmonic generators each including a separate laser diode chip 930 and a nonlinear crystal and a transmission part. Can be adjusted.

In addition, when the laser diode chip 930 is closely arranged on one base plate 920, the volume of the light emitting portion is reduced rather than when the harmonic generators are arranged. As a result, a light source such as a line beam generator is used. The volume of the entire device (eg, the display device) can be reduced.

10 is a view showing a line beam generator using a harmonic laser according to another embodiment of the present invention.

A difference from the line beam generator according to the embodiment shown in FIG. 9 is that the light emitter 1000 includes an array of laser diodes 1010 (laser diode array). That is, according to another embodiment of the present invention, there is a feature that the base plate 1020 corresponding to one laser diode chip 1030 exists separately one by one.

The line beam generator illustrated in FIG. 10 is largely composed of a light emitting part 1000, a medium part 1040, and a transmitting part 1060. The laser light may be emitted from the light emitter 1000. The light emitting unit 1000 is configured by arranging a plurality of laser diodes 1010 in which one laser diode chip 1030 is coupled to one base plate 1020. That is, the light emitter 1000 includes a plurality of laser diodes 1010 arranged in a row. Here, since the plurality of laser diodes 1010 are arranged in a line, the laser beams emitted from the light emitting unit may be converted into harmonic lasers to form a line beam.

The laser light emitted from the light emitting part 1000 first enters the medium part 1040. The material forming the medium portion 1040 may be a material generating a harmonic laser (eg, a second harmonic (SHG laser)). Therefore, the medium portion 1040 may be made of a nonlinear crystal such as a crystal or a material such as PPLN. The light incident on the medium portion 1040, that is, the pumping light 1050 is repeatedly reflected in the inside of the medium portion 1040 while reciprocating between the surface on the light emitting portion 1000 side and the surface on the transmissive portion 1060 side ( 1050). Such reflection is possible because a material having a high reflectance is applied to both surfaces of the medium portion 1040 as described with reference to FIG. 9.

In this process, second harmonics may be generated from the laser light incident on the medium part 1040. The harmonic laser 1080 generated through the above process is emitted to the outside of the line beam generator through the transmission point 1070 of the transmission unit 1060.

Here, as in the embodiment of FIG. 9, there is a point at which the harmonic laser 1080 is transmitted among the transmission parts 1060. The transmission point 1070 has a curvature unlike other portions of the surface forming the transmission part 1060 to transmit the harmonic laser 1080 in parallel or while diverging. One embodiment of the method for increasing the curvature of the transmission point 1070 may be to have a concave surface than other portions of the transmission portion 1060 by supplying heat to the transmission point 1070 to thermal expansion. .

The harmonic laser 1080 (second harmonic) passing through the transmission point 1070 through the above-described process constitutes a line beam. In this case, when the wavelength of the pumped light is 1064 nm and the wavelength of the harmonic laser 1080 is 532 nm, the formed line beam may be green light.

According to an embodiment of the present invention, when the wavelength of the pumped light is 1064 nm, the line beam 1080 formed by the line beam generator according to the present embodiment may be green light having a wavelength of 532 nm due to the frequency being doubled.

As in the case of the present embodiment, when the light emitting unit 1000 is configured by arranging the laser diodes 1010, there is an advantage in that the line beam may be easily prevented or corrected due to a process error. In addition, the size of the entire optical system may be adjusted by adjusting the distance between the laser diodes 1010.

11 is a diagram illustrating a line beam generator using a multiple reflection mirror method and a harmonic laser according to an embodiment of the present invention, and FIG. 12 is a line using a multiple reflection mirror method and a harmonic laser according to another embodiment of the present invention. It is a figure which shows the beam generating apparatus. The difference with FIG. 3, 4, 9, 10 mentioned above is demonstrated mainly.

Referring to FIG. 11, the light 1110 incident from the light source, the line beam 1120, the total reflection mirror 1130, the transflective mirror 1140, the second medium portion 940, the pumping light 950, and the light emission A portion 960, transmission point 970 and harmonic laser 980 are shown. The line beam 1120 formed through the transflective mirror 1140 and the total reflection mirror 1130 is incident on the second medium portion 940. Thereafter, the pumping light 950 is formed, and the harmonic laser 980 is emitted through the transmission point 970 of the light emission part 960. Through such a structure, the line beam 1120 having uniform intensity is converted into the harmonic laser 980 having a preset wavelength and emitted.

In addition, referring to FIG. 12, the light 1210, the line beam 1220, the transmission part 1225, the first medium part 1227, the total reflection mirror 1230, the transflective mirror 1240, and the second light source are incident from the light source. Two media 940, pumping light 950, light emitting 960, transmission point 970 and harmonic laser 980 are shown. The line beam 1220 formed through the transmissive part 1225, the total reflection mirror 1230, the transflective mirror 1240, and the first medium part 1227 is incident on the second medium part 940. Thereafter, the pumping light 950 is formed, and the harmonic laser 980 is emitted through the transmission point 970 of the light emission part 960. Through such a structure, the line beam 1120 having uniform intensity is converted into a harmonic laser 980 having a predetermined wavelength while emitting the line beam of FIG. 4.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, the line beam generator using the multiple reflection mirror method and the pumping method according to the present invention has an effect that the optical system is simple and insensitive so that adjustment is easy and uniformity is easily secured.

In addition, the line beam generator using the multi-reflective mirror method and the pumping method according to the present invention can make the optical system length shorter than the conventional method, the light having no interference by increasing the distance difference between the reflected light than the interference distance of the light source It is possible to reduce the speckle as a result of combining several.

In addition, the line beam generator using the multiple reflection mirror method and the pumping method according to the present invention can prevent the bending of the line beam, it is possible to secure the uniformity (uniformity) of the light distribution.

Although the above has been described with reference to a preferred embodiment of the present invention, those of ordinary skill in the art to the present invention without departing from the spirit and scope of the present invention and equivalents thereof described in the claims below It will be understood that various modifications and changes can be made.

Claims (25)

In the line beam generator, A semi-transmissive mirror which reflects a portion of the light incident from the light source and the total reflection mirror and transmits a portion thereof, and causes the transmitted light to form a line beam; The total reflection mirror reflecting light reflected from the transflective mirror toward the transflective mirror; A low reflection coating layer is formed on one surface of the transmitted light emitted from the transflective mirror, and a high transmission coating layer is formed on the other surface to transmit a high reflection coating layer and a harmonic laser formed from the transmitted light on the other surface to change the frequency of the transmitted light. A medium portion for changing to generate a harmonic laser; And And a transmission point having a predetermined curvature through which the harmonic laser beam is transmitted, and including a transmission part in contact with the medium part. The method of claim 1, The light beam incident from the light source is incident to the transflective mirror at an acute angle. The method of claim 1, And the transflective mirror and the total reflection mirror are parallel line beam generators. The method of claim 1, The transflective mirror has a transmittance that continuously varies with position, And wherein the transmittance is continuously changed according to the position of the transflective mirror so that the line beam formed through the transflective mirror has the same intensity according to the incident position. The method of claim 4, wherein And the continuous transmittance increases as the distance from the first incident light from the light source is incident. The method of claim 1, The transflective mirror has a transmittance that is discontinuously changed according to the position, and the transmittance is discontinuous according to the position of the transflective mirror so that the line beam formed through the transflective mirror has the same intensity according to the incident position. Line beam generator, characterized in that for changing. The method of claim 6, The discontinuous transmittance increases as the distance from the first incident light from the light source is incident. The method of claim 1, And said harmonic laser is a second harmonic. The method of claim 1, And the medium portion is a non-linear crystal. The method of claim 9, And the nonlinear crystal is either PPLN (Periodically Poled LiNbO ₃ ) or a crystal. The method of claim 1, And said harmonic laser is green light. The method of claim 1, And the predetermined curvature of the transmission point is generated by thermal expansion due to the reflection of the laser light at the transmission point. In the line beam generator, A semi-transmissive mirror which reflects a portion of the light incident from the light source and the total reflection mirror and transmits a portion thereof, and causes the transmitted light to form a line beam; The total reflection mirror reflecting light reflected from the transflective mirror toward the transflective mirror; A first medium part on which one side of the total reflection mirror is located, and the other side of the transflective mirror, and the light projected from the light source and the reflected light travel; A low reflection coating layer is formed on one surface of the transmitted light emitted from the transflective mirror, and a high transmission coating layer is formed on the other surface to transmit a high reflection coating layer and a harmonic laser formed from the transmitted light on the other surface to change the frequency of the transmitted light. A second medium portion to change to produce a harmonic laser; And And a harmonic laser transmitting portion having a predetermined curvature through which the harmonic laser beam is transmitted, and having a harmonic laser transmitting portion in contact with the second medium portion. The method of claim 13, And an incident light transmitting part that transmits the light incident from the light source and is located on one surface of the medium part in which the total reflection mirror is located. The method of claim 13, The light beam incident from the light source is incident to the transflective mirror at an acute angle. The method of claim 13, And the transflective mirror and the total reflection mirror are parallel line beam generators. The method of claim 13, The transflective mirror has a transmittance that continuously varies with position, And wherein the transmittance is continuously changed in accordance with the position of the transflective mirror so that the line beam formed through the transflective mirror has the same intensity according to the incident position. The method of claim 17, And the continuous transmittance increases as the distance from the first incident light from the light source is incident. The method of claim 13, The transflective mirror has a transmittance that is discontinuously changed according to the position, and the transmittance is discontinuous according to the position of the transflective mirror so that the line beam formed through the transflective mirror has the same intensity according to the incident position. Line beam generator, characterized in that for changing. The method of claim 19, The discontinuous transmittance increases as the distance from the first incident light from the light source is incident. The method of claim 13, And said harmonic laser is a second harmonic. The method of claim 13, And the medium portion is a non-linear crystal. The method of claim 22, And the nonlinear crystal is either PPLN (Periodically Poled LiNbO ₃ ) or a crystal. The method of claim 13, And said harmonic laser is green light. The method of claim 13, And the predetermined curvature of the transmission point is generated by thermal expansion due to the reflection of the laser light at the transmission point.

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