KR20180108508A - Lgp for transparent display device with refraction grooves by imprinting, transparent display device with the lgp and production method thereof - Google Patents

Abstract

The present invention relates to a light guide plate for a transparent display having a fine refraction groove through an imprinting method, a transparent display device including the same, and a method for manufacturing the same. The technical object of the present invention is to provide the light guide plate for a transparent display, which improves light efficiency and light uniformity to improve a two-side luminance ratio. Another technical object of the present invention is to provide the light guide plate, capable of solving a sparkling phenomenon, which is a phenomenon partially sparkled in a final panel by controlling roughness of an edge and a surface fine unevenness generated when imprinting a refractive groove as a pattern mold formed by exposure in a conventional invention. To this end, the light guide plate for a transparent display of the present invention comprises a first refractive groove having a shape of a plurality of truncated cones or quadrangular pyramid frustums formed on an upper surface of a resin provided on an upper surface of a transparent substrate. According to another embodiment of the present invention, the light guide plate for a transparent display comprises a second refractive groove having a shape of a plurality of horn type truncated cones or horn type quadrangular pyramid frustums formed on an upper surface of a transparent substrate. According to the present invention, the transparent display which can be improved by 2 to 4 times as compared to an existing light guide plate for a transparent display, and has the improved two-side luminance ratio of 24 : 1 at maximum, can be provided. Also, a sparking problem which is a shape partially sparkled at a final panel of a transparent display is solved, thereby reducing a glare phenomenon of a user.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate for a transparent display having fine refraction grooves formed through imprinting, a transparent display device including the same and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate for a transparent display having fine refraction grooves formed through an imprinting method, a transparent display device including the same, and a method of manufacturing the same.

A light guide plate (LGP) is a component for improving the brightness of a liquid crystal display device. When a liquid crystal display device can not emit light by itself and uses a light source, light is distributed through the light guide plate to the entire area of the liquid crystal display device And it can be transformed into a surface light source with a more uniform brightness by using this. The efficiency of the light emitted from the initial light source may gradually decrease. The side light is changed to the front light through the pattern of the light guide plate, and the emitted light is condensed to increase the luminance. Such a light guide plate may be used as a backlight of an LCD or a surface light source of a billboard.

Background Art [0002] In order to convert light metering into front light, prior art for designing a pattern groove in a light guide plate including the prior art has been developed.

Korean Unexamined Patent Application Publication No. 10-2005-0007828 (January 21, 2005) discloses a light guide plate which uses a pattern of a polygonal pyramid shape to cause light emitted from a light source to be incident from a side surface and to be directed to an upper surface. It is possible to change the light metering to the front light. However, there is a problem that sparkling phenomenon, which is a partially shiny phenomenon in the final panel, occurs because the edge and the surface are rough and the light is irregularly reflected.

Korean Patent Registration No. 10-1211726 (2012.12.06.) Discloses a reflector-integrated pattern light guide plate in which a white ink is coated on an engraved pattern. This is because, due to the periodic pattern, two vertically- There is a problem that a moire phenomenon (or a moire phenomenon) occurs in which a thick banding (moire pattern) caused by a difference in spatial frequency occurs when hit.

Korean Patent Laid-Open Publication No. 10-2016-0013357 (Feb. 26, 2014) discloses a light guide plate including a periodic linear nano pattern, which also causes a moire phenomenon caused by a periodic pattern.

Korean Patent Publication No. 10-1227557 (Mar. 23, 2013) discloses a light guide plate which has a pattern of a cone-shaped groove to uniformly scatter light from an incident light source to form a uniform illuminance. There is a problem that sparkling phenomenon occurs due to diffuse reflection due to rough surface and the size of grooves is different from each other, so that there is a problem that a pattern line is visually recognized.

 There has been no description of a light guide plate for a transparent display which improves brightness by solving the problems of sparkling phenomenon and moire phenomenon to be solved by the present invention and thus has improved front and rear luminance ratio.

Korean Patent Publication No. 10-2005-0007828 (2005.01.21.) Korean Registered Patent No. 10-1211726 (2012.12.06.) Korean Patent Publication No. 10-2016-0013357 (Feb. Korean Registered Patent No. 10-1227557 (Mar. 23, 2013)

A technical problem of the present invention is to provide a light guide plate for a transparent display having improved light efficiency and light uniformity and improved front / rear luminance ratio.

 Another object of the present invention is to improve the sparkling phenomenon, which is a partially sparkling phenomenon in the final panel, by controlling the roughness of the corners and fine irregularities generated when imprinting the conventional refraction grooves into a pattern mold formed by exposure. And a light guide plate.

 Another object of the present invention is to provide a light guide plate which is improved in moire phenomenon caused by an interference phenomenon due to a periodic pattern.

 The technical objectives to be achieved by the present invention are not limited to the above-mentioned exemplary technical problems, and other technical subjects not mentioned can be clearly understood by those skilled in the art from the following description.

To this end, the present invention provides a light guide plate for a transparent display having a plurality of truncated cones formed on the upper surface of a resin provided on an upper surface of a transparent substrate, or a first refraction groove having a shape of a quadrangular pyramid.

According to another aspect of the present invention, there is provided a light guide plate for a transparent display comprising a plurality of trumpet-shaped frustums formed on an upper surface of a transparent substrate or a second refraction groove having a truncated quadrangular pyramidal shape.

According to the present invention, it is possible to provide a transparent display having an improved front-to-back luminance ratio, and the sparkling problem, which is a partially shiny shape in the final panel of the transparent display, is improved, thereby reducing the user's glare.

 In addition, the Moire phenomenon due to the optical interference phenomenon of the pattern is improved, the fatigue of the user's eyes can be reduced, and the brightness of the screen can be uniformly improved.

 In addition, since the brightness is not reduced without adding beads, the production cost of the light guide plate and the transparent display including the light guide plate is reduced, and the inconvenience in the process is reduced.

 As a result, the light efficiency increases, the front / rear luminance ratio can be improved by 2 to 4 times as compared with the conventional transparent display light guide plate, and the front / rear luminance ratio of 24: 1 can be achieved.

Finally, there is an effect that the degree of purchase of the light guide plate of the present invention can be increased.

1 is a perspective view of a light guide plate and a light source together according to an embodiment of the present invention.
2 is a side view showing a light guide and a light source together in an embodiment of the present invention.
3 is a cross-sectional view illustrating a process of forming a first refractive groove according to an embodiment of the present invention.
4 is a view showing a step of forming a first refractive groove of an embodiment of the present invention.
5 is a perspective view showing a truncated conical first refraction groove of an embodiment of the present invention.
6 is a perspective view showing a quadrangular pyramid-shaped first refractive groove according to an embodiment of the present invention.
Fig. 7 is a cross-sectional view and an enlarged view showing fine irregularities of a first refractive groove according to an embodiment of the present invention.
8 is a cross-sectional view illustrating a process of forming a second refractive groove according to an embodiment of the present invention.
Fig. 9 is a step diagram showing a step of forming a second refractive groove of an embodiment of the present invention.
10 is a perspective view showing a truncated cone-shaped second refractive groove according to an embodiment of the present invention.
11 is a perspective view showing a second refraction groove of a trumpet-shaped quadrangular pyramidal shape according to an embodiment of the present invention.
12 is a cross-sectional view showing a rounded portion of a second refractive groove according to an embodiment of the present invention.
13 is a plan view showing a cross-section of a light guide plate and a light source of an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Also, in order to clearly illustrate the present invention in the drawings, portions not related to the present invention are omitted, and the same or similar reference numerals denote the same or similar components.

The objects and effects of the present invention can be understood or clarified naturally by the following description, and the objects and effects of the present invention are not limited only by the following description.

The objects, features and advantages of the present invention will become more apparent from the following detailed description. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing a light guide plate and a light source together according to the present invention.

Referring to FIG. 1, the light guide plate 30 refracts / reflects light emitted from at least one light source 500 located on the side surface toward the display panel. The light guide plate 30 is composed of a transparent substrate 32 and a UV curable resin 31 applied on the transparent substrate. On the upper surface of the UV curable resin 31, a plurality of refraction grooves 310 310 'to be described later are formed.

The transparent substrate 32 and the UV curable resin 31 of the light guide plate according to the present invention are transparent materials and can be used in a variety of transparent display devices such as household appliances such as showcases and refrigerators, glass windows, desks, and the like.

The light source 500 may be disposed on the side surface of the light guide plate 30 to emit light. The light source 500 may be spaced apart from the light guide plate 30 by a predetermined distance, and the light source 500 may include at least one of a linear light source and a point light source, if necessary. For example, the source of light may include one or more of a CCFL lamp, a light guide bar, a laser, a combination of LED and lens, a combination of LED and light guide bar, and an interior lamp. Further, the point light source may include an LED. The light source 500 may be vertically arranged on the LED bar for RGB color mixing. The light source 500 of FIG. 1 is a point light source.

 The light guide plate 30 may have a rectangular shape as shown in FIG. 1, and the light source 500 may be disposed on one side of the light guide plate as shown in FIG. 1, but may be disposed on both sides or all sides.

The transparent substrate 32 may be made of a transparent material such as glass, acrylic, or the like, and is arranged to face a panel (e.g., a transparent LCD panel, not shown in Fig. 1) of the transparent display device.

The UV curable resin 31 refracts / reflects the light emitted from the side light source 500 in the front direction through the refraction grooves 310 310 'to be described later.

 Hereinafter, the refraction grooves and the method for manufacturing the refraction grooves will be described in detail with reference to FIGS. 2 to 11. FIG.

The refraction grooves 310 and 310 'function to refract / reflect the light emitted from the side light source 500 in the front direction as described above. At this time, a part of the light is refracted / reflected to divide the light toward the front direction and the light toward the rear direction, and the luminance ratio of the light to the front surface to the back surface is called the front and back luminance ratio. The refraction grooves 310 and 310 'according to the present invention are intended to realize a pattern having such a superior front-to-rear luminance ratio, that is, a larger amount of light going toward the front direction.

The refraction grooves 310 and 310 'according to the present invention have two pattern shapes of the first refraction groove 310 and the second refraction groove 310' as different embodiments, The groove 310 'has a shape derived from the first refractive groove 310. The first refractive groove 310' has a shape derived from the first refractive groove 310 and the second refractive groove 310 ' The embodiment will be described.

The first embodiment (the first refractive groove 310)

Hereinafter, a first refraction groove 310, which is a first preferred embodiment according to the present invention, will be described with reference to FIGS. 2 to 7. FIG.

The first refractive groove 310 is formed by applying UV curable resin 31 on the transparent substrate 32 and then imprinting the first pattern mold 20 to be described later on the upper surface of the UV curable resin 31 . The first refractive groove 310 may be conical or quadrangular, and may have a trapezoidal shape as shown in FIG.

FIGS. 3 and 4 illustrate the process of forming the first refractive groove 310.

As described above, the first refractive groove 310 is formed by imprinting the first pattern mold 20 on the upper surface of the UV curable resin 31 thinly coated on the transparent substrate 32. Hereinafter, the step of fabricating the first pattern mold 20 will be described.

As shown in FIG. 4, the first refractive groove 310 is formed through three steps of a first master forming step S100, a soft molding step S300, and an imprinting step S400. Each of the above steps will be described in detail with reference to FIG.

3 is a view showing the first master forming step S100.

After the thermoplastic resin 11 is applied to the upper surface of the base substrate 12, the mask m for exposure is disposed on the upper side of the thermoplastic resin 11 cured through the heat treatment at regular intervals, The first master 10 having a conical or quadrangular-pyramid-shaped first master groove 110 is formed by the molecular sieve of the thermoplastic resin 11 being cut off by the light s passing through the mask m, ) Is generated. The cone-shaped or quadrangular-pyramid-shaped shape is determined by the shape of the mask for exposure. When the mask for exposure is circular, the conical shape 110a is formed. In the case of a quadrilateral shape, the first master groove 110 of the quadrangular pyramid 110b is formed.

As described above, the first master groove 110 is formed by cutting the thermoplastic resin 11 thinly coated on the base substrate 12 by the light s. It is possible to change the height of the first master groove 110 and the angle of the side surface according to the wavelength of the light s at the time of exposure, the distance between the mask m and the thermoplastic resin, have. As an embodiment of the present invention, the first master groove 110 may continue to be exposed and may be cut to a portion contacting the base substrate 12 to form a truncated cone 110a or a quadrangular pyramid 110b. .

The first master groove 110 is provided with the mask m on the thermoplastic resin 11 and the thermoplastic resin is shaved so as to be inwardly deflected as the light s is exposed on the mask m, Or the quadrangular pyramid 110b may be formed in an inverted shape.

The first pattern mold 20 is formed by the first master 10 formed through the first master forming step S100 through the soft molding step S300 as shown in the process <b> and <c> . The process (S300) will be briefly described. A UV curable resin is coated on the upper surface of the first master (10), followed by UV curing. When the cured resin is removed, the first pattern mold 20 having protrusions corresponding to the shape of the first master groove 110 is formed.

After the soft molding step S300, the light guide plate 30 having the final first refraction groove 310 is completed through the imprinting step S400.

The imprinting step (S400) will be described with reference to the process <d> to <g> in FIG.

The UV curable resin 31 is applied to the upper surface of the transparent substrate 32 which is a component of the final light guide plate 30 as shown in <d> of FIG. After the first pattern mold 20 formed through the soft molding step S300 is imprinted on the UV curable resin 31, the UV curable resin 31 is cured by applying UV. After the UV curable resin 31 is completely cured, the first pattern mold 20 is removed to complete the light guide plate 30 in which the first refractive groove 310 is formed. It is preferable that the UV curable resin 31 is applied to a thickness greater than that of the thermoplastic resin 11 in the exposure / development step S100.

Hereinafter, the shape of the first refractive groove 310 will be described in detail with reference to FIGS. 5 and 6. FIG.

FIG. 5 is a view showing a conical bulge 310a first refracting groove, and FIG. 6 is a quadrangular prism 310b first refracting groove.

Hereinafter, the portion of the groove touching the upper portion of the UV curable resin 31 is referred to as an upper surface 314 and the inner bottom surface of the groove facing the upper surface is referred to as a lower surface 315. The diameter or the transverse length of the upper surface 314 is referred to as a top D and the diameter or the transverse length of the bottom surface 315 is referred to as a bottom line d. d).

In the preferred embodiment, the height H of the first refractive groove 310 may be 5 占 퐉 to 15 占 퐉, the length D of the first refractive groove 310 may be 20 占 퐉 to 50 占 퐉, May be 10 [micro] m to 25 [micro] m. In the above range, when light is refracted / reflected, the light efficiency can be increased, the pattern groove line can not be visually recognized, and more light can be emitted toward the front surface in the direction of the transparent substrate 32. The angle of the inner side inclination (hereinafter referred to as the side surface inclination) of the side surface with respect to the upper surface of the first refractive groove 310 may be 30 ° to 80 °.

 Tables 1 to 2 show a preferred embodiment of the first refractive groove 310.

The following Table 1 shows the simulation results of the front / rear luminance ratio according to the angle of the conical groove 310a according to the present invention.

Small diameter (탆) Height (탆) Angle (°) Large diameter (탆) Front and back luminance ratio 23.83 14 50 47.32 11.3 23.83 14 52 45.71 12.6 23.83 14 54 44.17 13.1 23.83 14 56 42.72 17.2 23.83 14 58 41.33 22.9 23.83 14 60 40.00 23.0 23.83 14 62 38.72 22.2 23.83 14 64 37.49 24.1 23.83 14 66 36.30 23.6 23.83 14 68 35.14 22.3 23.83 14 69 34.58 20.7 23.83 14 70 34.02 10.8 23.83 14 71 33.47 0.6 23.83 14 72 32.93 0.2

Referring to Table 1, when the height H of the first refractive groove 310 is 14 占 퐉 and the length of the lower surface 315 is 23.83 占 퐉, the side surface inclination When the angle is 56 ° to 69 °, the front-to-back luminance ratio is high, and when the angle is 64 °, it is found to be the maximum.

The following Table 2 shows the simulation results of the front / rear luminance ratios according to the angles of the quadrangular pyramidal grooves 310b according to the present invention.

Small diameter (탆) Height (탆) Angle (°) Large diameter (탆) Front and back luminance ratio 23.8 14 50 47.3 11.7 23.8 14 52 45.7 14.6 23.8 14 54 44.1 16.5 23.8 14 56 42.7 22.5 23.8 14 58 41.3 23.3 23.8 14 60 40.0 21.9 23.8 14 62 38.7 18.0 23.8 14 64 37.5 18.4

Referring to Table 2, when the height H of the first refractive groove is 14 占 퐉 and the length d of the lower surface 315 is 23.83 占 퐉, the side inclination angle of the quadrangular pyramidal grooves 310b is 55 ° to 62 °, it can be seen that the front-to-back luminance ratio is high, and the maximum is at 58 °.

The above-mentioned Tables 1 to 2 show the results of simulation in which the angle at which the front-to-back luminance ratio becomes maximum when the height of the first refractive groove 310 before heat treatment is 14 占 퐉.

However, since the shape of the first refractive groove 310 is such that the molecular bond of the thermoplastic resin 11 is cut off through the exposure during the formation of the first master 10, a part of the resin is cut off, Fine concavities and convexities w are formed on the substrate 110. Therefore, fine irregularities w are formed on the surface of the side surface of the first refractive groove 310 manufactured using the first master 10. FIG. 7 is an enlarged view of fine unevenness w formed on edges and side surfaces of the first refractive groove 310. The surface is roughened by the fine irregularities (w), and diffused light from the uneven fine irregularities (w) is incident on the side surface, thereby causing a sparkling phenomenon, which is a partially sparkling phenomenon in the final panel . This sparkling phenomenon occurs more often than when the number of the refraction grooves 310 is increased in order to improve the overall luminance, thereby causing visibility problems.

In order to solve the sparkling phenomenon, the present invention performs additional heat treatment on the thermoplastic resin (11) of the first master (10) to form the first refraction grooves (310) We propose a solution to the sparkling contour that occurs in the wing.

The heat treatment is a process for removing fine irregularities w on the first master 10 after the first master 10 is completed.

The second embodiment (the second refractive groove 310 ')

Hereinafter, a second refractive groove 310 'as a second preferred embodiment of the present invention will be described with reference to FIGS. 8 to 12. FIG.

FIGS. 8 and 9 illustrate a process of forming the second refractive groove 310 '.

As shown in FIG. 9, the second refraction groove 310 'is formed by forming a second master through the heat treatment step after the first master forming step S100 in the step of fabricating the first refraction groove 310 Is formed through step S200. The heat treatment step S210 will be described in detail with reference to FIG.

내지 140

의 열을 상기 제1 마스터 홈(110)이 형성된 제1 마스터(10)에 30초 내지 180초 동안 가열하는 것이 바람직하다.8 is the same as the process of fabricating the first master 10 through the first master forming step S100. As described above, in order to remove fine irregularities w on the first master 10 manufactured through the first master forming step S100, as shown in <b> and <c> of FIG. 8 And the heat treatment step S200 is performed. The heat treatment is performed through a display heat treatment oven or the like 100

140

To the first master 10 on which the first master groove 110 is formed, for 30 seconds to 180 seconds.

A master formed through a second master forming step (S200) through heat treatment as shown in <c> of FIG. 8 is referred to as a second master 10 '. The second master 10 'is formed by uniformly applying heat to the entire first master 10 on which the first master grooves 110 are formed. More specifically, the fine unevenness w of the first master groove 110 is formed by melting with a smooth curved surface by heat treatment. The shape in which the fine unevenness is melted through the heat treatment has the shape of the trumpet-type truncated cone 110'a or the trumpet-shaped truncated pyramid 110'b. The trumpet cone (110'a) second master groove is formed by melting the first cone (110a) first master groove through heat treatment, and the trumpet cone (110'b) The first quadrilateral pyramid 110b is formed by melting through a heat treatment.

After the second master forming step S200, the soft refracting step S300 and the imprinting step S400 are performed in the same manner as the manufacturing of the light guide plate 30 in which the first refracting grooves 310 are formed, The light guide plate 30 'in which the light guide plate 310' is formed is completed.

UV curable resin is applied to the upper surface of the second master 10 'as shown in <d> and <e> of FIG. 8, and then the UV curable resin cured by applying UV is applied to the second pattern mold 20' do. After the UV curable resin is applied to the upper surface of the transparent substrate 32 as shown in FIG. 8, the refraction groove 310 formed by imprinting the second pattern mold 20 ' Quot; two refraction grooves 310 '.

Since the surface of the edge and the side surface of the second refraction groove 310 'are smoother than the surface of the first refraction groove 310, the light refracted by the side It is possible to prevent the sparkling phenomenon caused by the diffuse reflection.

In FIG. 8, reference symbol 31 'denotes a resin 31' provided with a second refractive groove by '31' after the reference numeral 31 in order to specify a difference from the resin 31 provided with the first refractive groove.

Hereinafter, the shape of the second refractive groove 310 'will be described in detail with reference to FIGS. 10 to 12. FIG.

The second refractive groove 310 'may be a rounded shape 311', 312 ', or 313' curved inwardly of the groove. More specifically, the second refraction grooves 310 'are formed in the second pattern mold 310' formed through the soft molding step S300 based on the melted second master 10 'by the heat treatment in the second master forming step S200. (Step S400) of the first refraction groove 20 ', the fine concavities and convexities w may be removed from the surface of the side surface of the first refraction groove 310 and rounded to a smooth curve shape. 12, the rounded shapes 311 ', 312', and 313 'can be divided into an upper edge 311', a side surface 312 ', and a lower edge 313'. The edge 311 'and the side surface 312' of the upper surface may have a curved surface having an inclination increasing from the upper surface 314 'to the lower surface 315', and the edge 313 ' The shape of the curved surface may be a truncated truncated cone 310'a or truncated quadrangular pyramid 310'b as described above. .

According to a preferred embodiment of the present invention, the height of the second refraction groove 310 'may be equal to the height of the first refraction groove 310, and more preferably 6 to 8 μm. The lower groove (d) of the second refractive groove 310 'may be 20 탆 to 50 탆 and the upper groove (D) may have a length of 10 탆 to 25 탆. More preferably, the lower groove (d) - 33 탆, and the upper line (D) may be 15 탆 - 22 탆. In addition, the height h1 of the edge rounding part 311 'of the upper surface and the height h2 of the edge rounding part 313' of the lower surface may be 0.1 탆 - 1 탆, and more preferably the edge rounding The height h1 of the portion 311 'is longer than the height h2 of the edge rounding portion 313' of the lower surface.

Hereinafter, the inclination to be described in the embodiment means the inclination of the rounded portion 312 'of the side surface. When a line segment parallel to the upper surface and the lower surface is referred to as a reference line c, And a reference line intersecting the tangent line.

According to one embodiment of the second refraction groove 310 ', in the 17-inch light guide plate, after the height of the second refraction groove 310' is fixed to 6 μm, simulation has been performed. As a result, D is 27 占 퐉, the bottom line (d) is 20 占 퐉, the maximum angle of inclination is 65 占 and the minimum angle of inclination is 55 占 and the total number of patterns is 20,813,906, I could get the rain.

According to another embodiment of the second refraction groove 310 ', in the 17-inch light guide plate, after the height of the second refraction groove 310' is fixed to 7 μm, simulation is performed. As a result, D is 33 탆, the bottom line (d) is 22 탆, the maximum angle of inclination is 68 占 and the minimum angle of inclination is 40 占 and the total number of patterns is 6,631,926, A front / rear luminance ratio of 18: 1 can be obtained, but the transparency can be further increased.

According to another embodiment of the second refraction groove 310 ', a height of the second refraction groove 310' is fixed to 6 μm in a 20-inch light guide plate, and then a simulation is performed. As a result, (D) is 22 占 퐉, the bottom line (d) is 15 占 퐉, the maximum angle of inclination is 65 占 and the minimum angle of inclination is 55 占 and the total number of patterns is 2,083,1906, The front-to-back luminance ratio was obtained.

More preferably, the angle of inclination of the side surface of the above embodiments is in the range of 55 to 65, and the most suitable front / rear luminance ratio can be obtained. In addition, an ideal front-to-back luminance ratio can be obtained as much as the angle of 55 ° to 65 ° that allows the inclination of the side surface of the second refractive groove 310 'is maintained.

13 is a cross-sectional view showing the arrangement shape of the refraction grooves 310 on the end face of the light guide plate 30. FIG.

13, the light guide plate 30 has a recessed refraction groove 310 formed in a UV curable resin 31, and the refraction groove 310 totally reflects light from a light source incident from the side, (32) and can be emitted toward the liquid crystal display panel.

The plurality of refraction grooves 310 may be formed on the UV curable resin 31 with a tilt in consideration of the pitch of the liquid crystal panel.

When two vertically parallel intensity distributions are overlapped, a moire phenomenon (or a moire phenomenon) in which a thick banding (moire pattern) caused by a difference in spatial frequency occurs is prevented. The moire phenomenon has a problem of causing a problem of visibility of the pattern.

 The plurality of refraction grooves 310 may be formed with a tilt at a predetermined angle with respect to the side surface of the light guide plate 30 with respect to the UV curable resin 31. When the plurality of refraction grooves 310 are arranged so as to have a tilt, the optical overlap between the grooves is eliminated or reduced, and moiré phenomenon is reduced or prevented.

The predetermined angle is preferably in the range of 5 to 20 degrees, and it is possible to form a tilt only in one of the x-axis direction and the y-axis direction according to the direction of the light source 500, A larger effect can be obtained when a tilt is formed.

Also, the refraction grooves 310 may be randomly formed. In this case, the effect of reducing or preventing the moire phenomenon can be maximized.

 The plurality of refraction grooves 310 may be formed in the UV curable resin 31 to have predetermined dithering in consideration of the liquid crystal pixel size.

The number of the refraction grooves 310 decreases as the distance of the plurality of refraction grooves 310 from the light source 500 decreases and the number of the refraction grooves 310 increases as the distance increases. Accordingly, as the distance from the light source 500 is increased, the reflectance of light can be increased to ensure a uniform and bright appearance over the entire observation range

It will be apparent to those skilled in the art that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Should be regarded as belonging to the above-mentioned patent claims.

 It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. But is not limited thereto.

Claims (9)

A plurality of second refractive grooves formed on the upper surface of the resin provided on the upper surface of the transparent substrate,
The second refractive groove is in the shape of a trumpet-shaped truncated cone or a trumpet-shaped quadrangular pyramid,
A side surface of the second refractive groove has a rounded shape having a curved surface with an increasing inclination toward the lower surface,
The lower surface of the second refractive groove is flat in the horizontal direction,
And the second refractive groove
A second pattern mold having a trumpet-shaped truncated cone or a trumpet-shaped quadrangular pyramid-shaped convex portion is imprinted on the upper surface of the resin,
The second pattern mold is formed by soft-molding a second master having a second master groove,
The second master groove may be formed in a substantially rectangular shape,
Wherein the minute concavities and convexities are formed by melting the first master groove of a truncated cone or quadrangular pyramid shape having fine concavities and convexities on the side surface thereof.
The method according to claim 1,
And the inclination of the side surface of the second refraction groove is in the range of 55 ° to 65 °.
The method according to claim 1,
Wherein the heat treatment applies heat of 100 占 폚 to 140 占 폚 to the first master.
The method according to claim 1,
The light guide plate has a rectangular shape,
And at least one light source positioned at a side surface of the light guide plate and irradiating light to a side surface of the second refraction groove.
5. The method of claim 4,
Wherein the plurality of second refraction grooves are arranged parallel to each other at an angle of 5 to 20 with respect to a side surface of the light guide plate provided with the light source.
5. The method of claim 4,
Wherein the second refractive grooves increase in number as the light source is further away from the side where the light source is installed, and are randomly arranged on the light guide plate.
A transparent display device comprising the light guide plate for transparent display according to any one of claims 1 to 6.
Forming a first master having a first master groove;
Forming a second master having a second master groove;
Soft-molding the second master to form a second pattern template; And
And imprinting the second pattern template, the method comprising the steps of:
The step of forming the second master comprises:
A second master is formed by deforming the first master groove of the truncated cone or quadrangular pyramid shape into a trumpet-shaped truncated cone or trumpet-shaped quadrangular pyramid shape through heat treatment,
The trumpet-shaped truncated cone or trumpet-shaped quadrangular pyramid-shaped side surface has a rounded shape having a curved surface whose inclination increases toward the lower surface,
Wherein the bottom surface of the trumpet-shaped truncated cone or trumpet-shaped quadrilateral pyramid is flat in the horizontal direction.
9. The method of claim 8,
Wherein the heat treatment step is performed by applying heat of 100 占 폚 to 140 占 폚 to the first master to remove fine irregularities on a side surface of the first master groove.

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