KR20100025215A - A system for patterning a light guid plate for a backlight unit using a high power laser - Google Patents

Abstract

PURPOSE: A system for patterning a light guide plate for a backlight unit using a high power laser is provided to offer uniform brightness on a large sized light guide plate used for a backlight unit of a large size light receiving flat display device, using a high power carbon dioxide laser. CONSTITUTION: A laser beam emitting unit(111) generates a high power laser beam. A beam splitting unit(112) separates a path, an output, a strength, and a spot of an oscillated laser beam generated from the laser beam generation unit. A head support unit(114) arranges a plurality of head units(113) focusing a plurality of laser beams coming out from the beam splitting unit. A feeding unit(115) transfers the plurality of head units in one direction as a whole.

Description

Light guide plate patterning system for backlight unit using high power laser {A SYSTEM FOR PATTERNING A LIGHT GUID PLATE FOR A BACKLIGHT UNIT USING A HIGH POWER LASER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate patterning system for a backlight unit using a high power laser, and more particularly to a large light guide plate used for a back light unit of a large light receiving type flat panel display using one high power CO ₂ laser. The present invention relates to a light guide plate patterning system for a backlight unit using a high power laser capable of forming the same or different patterns for different regions so as to provide uniform luminance.

Recently, as the flat panel display devices are enlarged, the panel for providing images and the backlight unit for providing light to the panels are also enlarged.

The light guide plate constituting a part of the backlight unit currently uses a transparent acrylic plate and forms a pattern on the surface by various methods to uniformly distribute the brightness of the entire light guide plate so that the brightness of the entire screen is evenly distributed.

As a method of forming a pattern on the surface of such a light guide plate, a printing processing method, a cutting processing method, and a laser processing method are mentioned.

Among the various methods described above, a printing processing method is used to form a pattern on a medium-large light guide plate used in a medium panel or a large panel of 40 inches or more.

The printing process masks a portion where a pattern is not to be formed on the light guide plate substrate, prints the pattern thereon, and forms a pattern by etching the portion printed with the etchant.

However, according to this method, an etching solution may penetrate between the mask and the light guide plate under the mask, thereby causing a defect, requiring skilled work, and having a problem in that luminance is lowered due to a poor pattern.

In addition, the cutting method is a mechanical processing of the V-notch to the light guide plate using a V-type cutter, but the long production time, low production efficiency, difficult to form a fine pattern, and uniform light diffusion is not achieved Deformation of the substrate may occur due to frictional heat due to an increase in the friction area, and when the direction of movement of the cutter is changed, the substrate may be easily cracked, thereby making it difficult to form various patterns.

In order to solve this problem, a laser processing method has recently been used.

By the way, such a laser processing method is suitable for small substrates because it must be controlled to irradiate perpendicularly to the light guide plate substrate by using a reflecting mirror, but has a problem in that the tag time is long for large substrates.

In order to solve this problem, processing using several laser equipment, or processing the laser equipment by moving the X, Y, Z stage, or forming a pattern on several pieces of substrate and then combining the pieces to a large area Although a method for forming a light guide plate substrate of the light guide plate has been proposed, it is difficult not only to control a plurality of laser devices individually or to perform precise control according to the movement of the X, Y, and Z stages, but also from a light source along a large area. There is a problem in that the pattern that varies depending on the distance can not be represented continuously and each pattern is not connected or irregular in the joint.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to independently form a variety of patterns for a plurality of areas at a time for the substrate for a large light guide plate using a high-power laser The present invention provides a light guide plate patterning system for a backlight unit using a high power laser that can improve work efficiency and increase production efficiency.

The light guide plate patterning system for a backlight unit using a high power laser according to an embodiment of the present invention for achieving the above object comprises an optical table and a work table in a multi-layer structure, one for oscillating a high power laser beam on the optical table A laser beam oscillation unit, a beam splitting unit for separating at least two paths, outputs, intensities, and spots of the laser beams oscillated from the one laser beam oscillating unit, and a plurality of lasers emitted from the beam splitting unit A head support unit having a plurality of head portions for focusing beams respectively, and a first transfer unit for moving the head support units in one direction to move the plurality of head portions in one direction at a time with respect to the whole; The work table is disposed on the work table to accommodate the light guide plate substrate, Table is provided with a second transfer unit for moving the work table to move in a direction normal to the direction of the first transfer unit.

According to an embodiment of the present invention as described above, by arranging the optical table and the work table in a multi-layer structure, the laser beam output from one high-power laser beam oscillation unit on the optical table disposed in the upper layer portion divided into a beam splitting unit By simultaneously processing the pattern at different positions of the large light guide plate substrate, the pattern processing efficiency can be increased, and the operation efficiency can be improved because the movement of the optical table and the work table does not interfere with each other, Operation is easy because several lasers do not need to be controlled to oscillate.

In addition, since a large light guide plate of 20 inches or more can be worked at once, uniformity and brightness can be uniformly improved even on a large screen without any problem of joints, thereby providing a high quality screen.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail as follows.

1A is an exploded perspective view of a backlight unit according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view of the backlight unit of FIG. 1A.

1A and 1B, a backlight unit 1 according to an exemplary embodiment of the present invention may include a light guide plate 10 and a reflector plate 11 disposed below the light guide plate 10 to reflect light upward. A diffusion plate 13 disposed above the light guide plate 10 to scatter and diffuse light forward, and at least one light source disposed on a sidewall of the light guide plate 10 to irradiate light toward the light guide plate 100. And (15). As the light source 15, an external electrode fluorescent lamp or an external internal fluorescent lamp may be used, and an LED having environmentally friendly characteristics may be used. The light source 15 is enclosed by a cover member 17 having a reflective film to inject light irradiated in the opposite direction of the light guide plate 10 back to the light guide plate 10.

On the other hand, on the light guide plate 10 for a large backlight unit according to an embodiment of the present invention, the pattern portion 10a is formed by a high power laser. Since the pattern portion 10a is formed by cutting the pattern once more than the printing method or the mechanical V-cutting method, and then cutting it once more to form the multi-faceted cutting portion 10ab, the surface area is increased to scatter more light. Or can be reflected.

In addition, the light guide plate 10 may further include a pattern portion 10b having a larger surface area as it moves away from the light source 15 to provide uniform brightness and uniformity as a whole.

That is, considering that the light source 15 is provided in a deflected or asymmetrical manner, each of the pattern parts 10a and 10b is provided with a multi-faceted cutting part 10ab so as to effectively reflect and scatter light, thereby varying the surface area. Even if away from the light source 15, it is possible to increase the amount of scattering and reflection of light to provide a uniform brightness and uniformity as a whole.

At this time, the pattern portions 10a and 10b of the light guide plate 10 are formed in a predetermined pattern on the lower surface of the light guide plate 10. As shown, a dot type, a straight type, or a mixed type in which a dot type and a straight type are combined Can be processed into grooves. In addition, it may be processed into a square or lattice, or a groove by a combination of these shapes.

On the other hand, the light (arrow) irradiated from the light source 15 disposed on the light guide plate 10 to further diffuse the light diffuser 10c of fine scratches to be uniformly diffused to the entire surface of the light guide plate 10. Could be

According to one embodiment of the invention, the pattern portion (10a, 10b, 10c) formed on at least one surface of the light guide plate 10, each divided by a high power laser beam generated from one laser oscillation unit at least two or more laser heads It may be simultaneously formed by a plurality of laser beams irradiated through the unit.

A light guide plate patterning system for a backlight unit using a high power laser for forming a pattern on the light guide plate for a large backlight unit will be described in detail with reference to the accompanying drawings.

2 is a plan view schematically showing a light guide plate patterning system for a backlight unit using a high power laser according to an embodiment of the present invention, Figure 3 is a light guide plate pattern for a backlight unit using a high power laser according to an embodiment of the present invention Side view of ning system. 4A and 4B are arrangement views showing the head arrangement of the head unit of the LGP patterning system for a backlight unit using a high power laser according to an embodiment of the present invention.

2 to 4, the light guide plate patterning system 100 for a backlight unit using a high power laser according to an embodiment of the present invention includes an optical table 110 and a work table 130 in a multilayer structure. .

On the optical table 110, the path, output, intensity, and spot of one laser beam oscillation unit 111 for oscillating a high power laser beam and the laser beam oscillated from the one laser beam oscillation unit 111 A head support unit 114 in which a beam splitting unit 112 for separating at least two or more, and a plurality of head portions 113 for focusing a plurality of laser beams from the beam splitting unit 112 are fixed in a predetermined arrangement. And a first transfer unit 115 for moving the head support unit 114 in one direction to move the entire head portion 113 in one direction at a time.

The work table 131 on which the light guide plate substrate 10 is accommodated is disposed on the work table 130, and the work table 130 has the work table in a direction perpendicular to the moving direction of the first transfer unit 115. A second transfer unit 135 for moving 130 is provided.

The laser beam oscillation unit 111 is characterized by generating a high power laser beam of about 400W using a CO ₂ laser oscillator.

The high-output laser beam output as described above may be separated into a plurality of laser beams by using the laser beam splitting unit 112 disposed on the same plane on the optical table 110.

The laser beam splitting unit 112 may divide the laser beam by arranging a plurality of reflecting mirrors 112a and a plurality of beam splitters 112b in multiple stages.

For example, the 400W high power laser beam irradiated from the laser beam oscillation unit 111 proceeds to the beam splitter 112b by the reflection mirror 112a, and the ratio of 50 to 50 by the one beam splitter 112b. Alternatively, the two laser beams reflected and transmitted at various ratios become four laser beams again by the reflecting mirror 112a and the beam splitter 112b, and then by the reflecting mirror 112a and the beam splitter 112b. It can be split into eight laser beams. That is, according to the increase and arrangement of the number of the reflecting mirrors 112a and the beam splitter 112b, the laser beam may be divided into several laser beams and proceed in various paths.

In one embodiment of the present invention, the beam splitter 112b preferably has the number n-1 of the laser head portions 113.

As described above, the laser beam divided into several parts may process a predetermined pattern at different positions with respect to the light guide plate substrate 10 through the plurality of heads 113.

 The plurality of head parts 113 may be fixed to the head support unit 114 in a predetermined arrangement. The head support unit 114 may include a body 114a and a support fixing part 114b, and the head portion 113 may be disposed on the side of the body 114a.

Preferably, the head portion 113 with respect to the body 114a is disposed in FIGS. 4A and 4B to reduce an area (dead zone) in which a plurality of laser beams cannot be processed when processing the light guide plate pattern in various areas. It is preferable to be arranged to be offset from each other, it is preferable that the body 114 is composed of an equilateral triangle pillar or trapezoidal pillar in order to further reduce the dead area.

When the body 114a is configured as an equilateral triangle pillar or a trapezoidal pillar, the head portion 113 may be disposed along the side thereof, and in this case, the head portion 113 may have a spacing D2 therebetween. The distance D1 due to the inclined arrangement can be reduced to reduce the distance between the patterns.

A lower portion of the head support unit 114 may further include a transfer unit 114c including a step motor, and may move in one direction along the guide rail 115a constituting the first transfer unit 115. The entire plurality of heads 113 may be moved in one direction at a time.

According to one embodiment of the present invention, the plurality of laser beams divided by the laser beam splitting unit 112 may be guided by the guide optical unit 116 to the head portion 113, the laser beam modulation unit By using a high speed shutter 117 to adjust the amplitude or phase, or to amplify the energy, the pattern portion 10a to be formed on the light guide plate and the multi-sided cutting portion 10ab in the pattern portion 10a can be formed.

The laser beam modulation unit 117 may use an acoustic-optic modulator (AOM) or the like.

The laser beam expander (BET) 118 may finally determine the size of the modulated laser beam corresponding to the shape of the pattern formed on the light guide plate.

A dumping unit 119 may be further provided to prevent the laser beam from leaking from the laser beam modulation unit 117 and contaminating the surroundings.

As such, the laser oscillation unit 111, the laser beam splitting unit 112, the head support unit 114, the first transfer unit 115, the guide optical unit 116, the modulation unit 117, and the beam expander ( 118 may be controlled according to a command of the controller 200.

The controller 200 may independently control the laser beam incident on the head 113 by independently controlling the guide optical unit 116, the modulation unit 117, and the beam expander 118. It is efficient because it can not change the alignment of the system.

On the other hand, since the work table 130 is disposed below the optical table 110 in a multilayer structure, the path of the laser beam on the optical table 110 is not disturbed by the movement of the work table 130. You may not.

The second transfer unit 135 of the work table 130 may move the work table 130 in the X-axis direction and the Y-axis direction, and may be aligned in consideration of the angle between the X-axis and the Y-axis. have.

However, preferably, the second transfer unit 135 transfers in a direction crossing the first transfer unit 115, and when the first transfer unit 115 is operated by the controller 200, The second transfer unit 135 may be configured to be fixed.

As such, the laser beam may be configured to stably process the laser beam pattern by being controlled by the controller 200.

In addition, as shown in Figure 3, the light guide plate patterning system 100 for a backlight unit using a high power laser according to an embodiment of the present invention is an optical table (110) and a work table 130 parallel to each other ) Is supported by the supporter 150, and a slab 170 is disposed below the work table 130 to maintain a horizontal level so that a plurality of laser beams may run in parallel on the optical table 110. , Can sustain vibration.

Therefore, according to the present invention, pattern processing is easy by forming a plurality of patterns in a plurality of areas on the light guide plate substrate at the same time by using a plurality of laser beams by splitting and modulating a plurality of laser beams output from one laser beam oscillation unit. It can double work efficiency, reduce the defect rate caused by controlling several laser oscillation units, and can process large area light guide plate without joining joints. It can be improved evenly, contributing to obtaining a high quality screen.

The above description is merely illustrative of the present invention, and those skilled in the art may make various modifications and changes without departing from the essential characteristics of the present invention. In addition, the protection scope of the present invention should be interpreted by the claims, and all technical ideas within the equivalent scope should be construed as being included in the scope of the present invention.

1A is an exploded perspective view of a backlight unit according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view of the backlight unit of FIG. 1A.

2 is a plan view schematically illustrating a light guide plate patterning system for a backlight unit using a high power laser according to an embodiment of the present invention.

3 is a side view of a light guide plate patterning system for a backlight unit using a high power laser according to an embodiment of the present invention.

4A and 4B are arrangement views showing the head arrangement of the head unit of the light guide plate patterning system for a backlight unit using a high power laser according to an embodiment of the present invention.

Claims (9)

In the light guide plate patterning system for a backlight unit using a high power laser, It includes an optical table and a work table in a multilayer structure, A laser beam oscillation unit for oscillating a high power laser beam on the optical table; A beam splitting unit for separating at least two paths, outputs, intensities, and spots of the laser beams oscillated from the one laser beam oscillating unit; A head support unit in which a plurality of head portions for focusing a plurality of laser beams from the beam splitting unit are fixed in a predetermined arrangement; And a first transfer unit for moving the head support unit in one direction to move the plurality of head portions in one direction at a time with respect to the whole. A work table on which the light guide plate substrate is accommodated; And a second transfer unit for moving the work table in a direction crossing the transfer direction of the first transfer unit. The method of claim 1, The laser beam oscillation unit is a light guide plate patterning system for a backlight unit using a high power laser using a CO ₂ laser having an output of 400 W or more. The method of claim 2, The laser beam splitting unit includes a plurality of reflecting mirrors and the number (N) -1 beam splitter of the head portion, and the beam splitter splits the beam into two by reflecting and transmitting the laser beam 50 to 50. Light guide plate patterning system for backlight unit using high power laser. The method of claim 3, wherein The laser beam splitting unit is a light guide plate patterning system for a backlight unit using a high power laser for irradiating the divided laser beams orthogonally to each other on the same plane. The method of claim 1, The head support unit includes a body and a support fixing part, wherein the body is composed of an equilateral triangle pillar or a trapezoidal pillar, and the plurality of head parts for a backlight unit using a high power laser fixed to the side of the pillar by the supporting fixing part. Light guide plate patterning system. The method of claim 5, wherein The body of the head support unit is composed of a rectangular parallelepiped, wherein the plurality of head portion is a light guide plate patterning system for a backlight unit using a high power laser is disposed offset to the side of the rectangular parallelepiped. The method of claim 1, A guide optical unit comprising a plurality of reflecting mirrors for guiding a laser beam to the head; A laser beam modulation unit for controlling the amplitude or phase of the laser beam divided by the laser beam splitting unit to amplify the energy to form a pattern portion having a multi-faceted cut portion in the light guide plate; A light guide plate patterning system for a backlight unit using a high power laser further comprising a beam expander for finally determining the size of the modulated laser beam. The method of claim 7, wherein The laser beam modulation unit is a light guide plate patterning system for a backlight unit using a high-power laser is an acoustic-optic modulator (AOM). The method of claim 1, The first transfer unit and the second transfer unit is a light guide plate patterning system for a backlight unit using a high-power laser is fixed to the second transfer unit when the first transfer unit is operated by a control unit.

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