KR100580890B1 - Light Guide Plate capable for controlling view angle and Method for making stamper used to make the same - Google Patents

Abstract

A light guide plate having a light source provided on at least one side, wherein a plurality of cells are disposed on a rear surface opposite to a surface from which light emitted from the light source is emitted, and in the cells are continuously extended in parallel to the longitudinal direction of the light source. And at least convex patterns or concave patterns having inclined surfaces facing the light source are formed to control the viewing angle of the light emitted to the surface by controlling the angle of the inclined surface.

Viewing angle, luminance, light quantity, cell, cell, group

Description

Light guide plate capable of controlling the viewing angle and manufacturing method of the stamper for manufacturing thereof {Light Guide Plate capable for controlling view angle and Method for making stamper used to make the same}             

1 is a perspective view illustrating a light guide plate according to an exemplary embodiment of the present invention.

FIG. 2 is an enlarged view illustrating in detail a convex pattern formed on a rear surface of the light guide plate of FIG. 1.

3 is a cross-sectional view taken along line III-III of FIG. 2.

4 is a cross-sectional view illustrating a case in which a concave pattern is formed on a rear surface of a light guide plate according to another exemplary embodiment of the present invention.

5 is a perspective view showing another embodiment of the present invention.

FIG. 6 is a flowchart illustrating a process of manufacturing a stamper applied to fabricating the light guide plate of the present invention.

7 is a flowchart corresponding to each step of FIG. 6.

The present invention relates to a light guide plate capable of controlling a viewing angle, and more particularly, to form a convex pattern or a concave pattern having an inclined surface opposite to a light source on the back surface opposite to the surface from which light of the light guide plate is emitted, and to control the inclination angle of the inclined surface. It relates to a light guide plate that can be controlled.

The present invention also relates to a light guide plate for controlling the luminance of light emitted by controlling the distribution density of cells of a constant size or the size of the cells formed of convex patterns or concave patterns formed on the rear surface of the light guide plate.

Furthermore, the present invention relates to a method for manufacturing a stamper applied to manufacturing the light guide plate described above.

A light guide plate is generally applied to a liquid crystal display and used as a means for applying light to an LCD module which is a passive element. That is, the light emitted from the light source disposed on the side or the bottom of the light guide plate, for example, a cold cathode fluorescent lamp, is guided and diffused to apply the light to the LCD module stacked on the surface side.

In addition, the luminance amount and the viewing angle of the light were controlled by laminating a diffusion sheet, a prism sheet, or the like on the surface side of the light guide plate on which light was emitted.

However, in recent years, efforts have been made to reduce the number of parts and thus simplify the structure or reduce the cost by implementing various components added to the light guide plate in the light guide plate itself.

For example, Japanese Patent Laid-Open No. 6-118247 discloses a light guide plate having a diffuse reflection portion composed of fine unevenness on either the back surface or the surface of the light guide plate, and having an attachment to control the amount of diffuse reflection such as transparent ink. It is. According to such a configuration, a light guide plate having good diffuse reflection efficiency and brightness can be manufactured simply and quickly. However, the proposal only mentions controlling the amount of light through diffuse reflection and attachments.

In addition, referring to Korean Patent Publication No. 341250, a light guide plate is disclosed to prevent the generation of moiré, improve light utilization efficiency, and prevent luminance irregularity by forming a dot-shaped concave portion on the rear surface of the light guide plate.

However, none of the above examples mentions an improvement in the viewing angle, and neither mentions any method of controlling the viewing angle.

Therefore, according to the related art, indirectly means that a separate component such as a prism sheet is used to secure the viewing angle.

Accordingly, it is an object of the present invention to provide a light guide plate capable of controlling the viewing angle by using the inclination angle of the inclined surface constituting the convex pattern or the concave pattern formed on the back surface.

Another object of the present invention is to provide a light guide plate capable of controlling luminance by controlling the distribution density or size of cells formed of the convex patterns and concave patterns.

Still another object of the present invention is to provide a method for manufacturing a stamper applied to manufacturing the light guide plate described above.

Still other objects and features of the present invention will be more clearly understood through the embodiments described below.

According to one aspect of the present invention, in a light guide plate having a light source installed on at least one side, a plurality of cells are dispersedly disposed on the back surface opposite to the surface from which light emitted from the light source is emitted, and within the cells, A light guide plate capable of controlling the viewing angle of light emitted to the surface by controlling the angle of the inclined surface is formed by forming convex patterns continuously extending in parallel with the light source and at least facing the light source.

According to another aspect of the present invention, in a light guide plate having a light source installed on at least one side, a plurality of cells are dispersedly disposed on the back surface opposite to the surface from which light emitted from the light source is emitted, and within the cells, A light guide plate capable of controlling the viewing angle of light emitted to the surface by controlling the angle of the inclined surface is formed by forming concave patterns each successively extending in parallel to the longitudinal direction and at least facing the light source.

Preferably, convex patterns are formed on the surface of the light guide plate, each of which continuously extends in parallel to the longitudinal direction of the light source and has inclined surfaces facing each other.

The inclination angle of the inclined surface has a range of 33 degrees to 47 degrees, and more preferably the inclination angle of the inclined surface is 43 degrees.

Preferably, the cell may be a circle having a diameter of 0.05mm to 2mm, the pitch of the convex pattern or concave pattern has a range of 1㎛ 100㎛.

In addition, the rear surface of the light guide plate may be inclined to become thinner as it moves away from the light source.

In addition, the amount of light emitted to the surface of the light guide plate may be controlled by controlling the size of the cell or the distribution density of the cell.

According to another aspect of the invention, the light guide plate; A light source installed on at least one side of the light guide plate; And it is disclosed a backlight assembly capable of controlling the viewing angle including a protective film having a diffusion function laminated on the light guide plate.

According to another aspect of the invention, forming a convex patterns extending in parallel in the first direction on the surface of the conductive base material; Applying a photoresist to a recess formed by the convex patterns on the conductive base material to flatten the entire surface; Exposing and developing the photoresist using a mask in which a cell region having a predetermined size is opened; And removing the developed photoresist, electroplating a metal material on the entire surface with the conductive base material as an electrode, and peeling the base material and the photoresist.

According to another aspect of the invention, forming a convex patterns extending in parallel in the first direction on the surface of the non-conductive base material; Applying a photoresist to recesses formed by convex patterns on the non-conductive base material to flatten the entire surface; Exposing and developing the photoresist using a mask in which a cell region having a predetermined size is opened; And removing the developed photoresist and forming a conductive material layer on the entire surface. Disclosed is a method of manufacturing a light guide plate stamper including the step of separating the stamper having a convex pattern by electroplating a metal material on the front surface with the formed conductive material layer as an electrode and removing the base material and the photoresist.

Preferably, the conductive material layer is formed by vacuum heating, chemical vapor deposition or electroless plating by resistive heating, electron beam, or sputtering.

In addition, the electroplating with a metallic material using a stamper as an electrode on the front surface of the convex pattern formed on the light guide plate stamper manufactured by the above manufacturing method, and separates the stamper formed by the concave pattern by separating the stamper to form a light guide plate stamper. I can make it.

At this time, preferably, the interfacial separation material may be applied to the entire surface on which the convex pattern of the stamper is formed.

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

1 is a perspective view illustrating a light guide plate according to an exemplary embodiment of the present invention, FIG. 2 is an enlarged view showing in detail a convex pattern formed on a rear surface of the light guide plate of FIG. 1, and FIG. 3 is a view along III-III of FIG. 2. It is a cut section.

Referring to FIG. 1, a light source 20, for example, a cold cathode fluorescent lamp, is installed at one side of the light guide plate 10, and the light emitted from the light source 20 is light guide plate 10. It is guided inward and exits directly to the surface 12 or is reflected off the backside 14 and exits to the surface. Alternatively, the light penetrates the back surface 14 and is reflected by a reflective sheet (not shown) to be incident to the light guide plate 10 again.

In this embodiment, the light source 20 is installed on one side as an example, but may be installed on both sides. In addition, although the light guide plate 10 has a wedge shape in which the thickness decreases as the distance from the side where the light source 20 is installed is used, a flat plate shape having a uniform thickness may be used.

In general, the wedge type is used in a liquid crystal display device applied to a notebook, etc., and the flat type may be used in a liquid crystal display device applied to a TV or a monitor.

According to the present invention, a plurality of cells 30 are distributed on the rear surface 14 of the light guide plate 10.

Referring to FIG. 2, convex patterns 32 extending in parallel to the longitudinal direction of the light source 20 and having at least inclined surfaces facing the light source 20 are formed in the cell 30.

Of course, if the concave patterns are formed instead of the convex patterns 32, the same effect will be described later.

Referring to FIG. 3, the convex patterns 32 are shown in more detail.

In this embodiment, the convex patterns 32 having a triangular cross-sectional shape are taken as an example, but a cross-sectional shape such as a quadrangle or a trapezoid may be used as long as the convex patterns 32 at least face the light source 20. In addition, the shape of the triangle may also be applied to the equilateral triangle, isosceles triangle, right triangle or general triangle.

When the cross section is a triangle, the base and height can be appropriately selected while maintaining the inclination angle described later within the range of 5 µm to 50 µm.

According to the present invention, the viewing angle of the light emitted to the surface 12 can be controlled by controlling the inclination angle θ of the inclined surface 32a opposite the light source 20 of the convex pattern 32. The inclination angle of the inclined surface 32a has a range of 33 degrees to 47 degrees in order to secure a preferable viewing angle when viewed from the front, and more preferably, in order to ensure an optimal viewing angle perpendicular to the liquid crystal panel, it has an inclination angle of 43 degrees.

In addition, by controlling the pitch P of the convex patterns 32, it is possible to control the brightness of the light emitted to the surface, preferably the pitch has a range of 1㎛ to 100㎛.

On the other hand, the cell 30 is distributed over the entire back surface 14, it may be any one, such as a circle, a square or a rhombus, preferably in the case of a circle may have a diameter of 0.05mm to 2mm.

In addition to controlling the pitch of the convex pattern, in order to control the brightness of the light emitted to the surface, the distribution density of the cells 30 may be controlled or the distribution density may be the same, and the size of the cells 30 may be controlled. In particular, the control of the luminance also includes implementing a uniform luminance over the entire surface, and the luminance is increased by decreasing the distribution density of the cells 30 or gradually decreasing the size of the cells 30 as they move toward the light source 20. It can be made uniform.

Referring to FIG. 3, the light c from the light source 20 is totally internally reflected on the back surface of the light guide plate 10 to guide the light, and the light a and b are reflected on the inclined surface 32a of the convex pattern 32 and emitted to the surface. do. At this time, by controlling the inclination angle θ of the inclined surface 32a, the emitted light can be emitted within a predetermined angle range so that the viewing angle can be controlled.

In addition, the light transmitted through the back surface is reflected by the inclined surface 32a to increase the light emitted to the surface to increase the brightness, and control the pitch of the convex pattern, that is, the brightness can be controlled by controlling the density of the convex pattern. .

4 is a cross-sectional view illustrating a case in which the concave pattern 34 is formed on the rear surface 14 of the light guide plate 10, according to another exemplary embodiment. The same effect as described above may be obtained.

In this embodiment, the viewing angle of the light emitted to the surface can be controlled by controlling the inclination angle θ of the inclined surface 34a facing the light source.

5 is a perspective view showing another embodiment of the present invention.

In this embodiment, convex patterns 16 are formed on the surface of the light guide plate 10 and extend continuously in parallel to the longitudinal direction of the light source 20 and have inclined surfaces facing each other.

The convex patterns 16 collect light emitted to the surface in the Y-axis direction to secure a viewing angle to further increase luminance at the front surface.

Therefore, the light condensing function may be performed using only the light guide plate 10 without applying a separate prism sheet, and the structure may be simplified and the manufacturing cost may be reduced by not applying an expensive prism sheet.

In addition, by laminating only the protective film having a diffusion function on the surface side of such a light guide plate 10, the backlight can be constituted and the structure becomes simpler.

FIG. 6 is a flowchart illustrating a process of manufacturing a stamper applied to fabricating the light guide plate of the present invention, and FIG. 7 is a corresponding process diagram.

Since the light guide plate according to the present invention has a convex or concave pattern formed on the rear surface thereof, for example, when manufacturing the light guide plate by an injection molding method, a mold pattern for forming a convex pattern or a concave pattern on the mold itself or a stamper is formed. It can be manufactured and installed in a mold.

In this embodiment, a method of manufacturing a stamper will be described, and this method can be analogously applied to forming a mold pattern.

For convenience of description, the present invention is limited to a method of manufacturing a stamper for a light guide plate having a concave pattern, and an example of using a non-conductive base material is given.

As the base material, both conductive and nonconductive materials can be used. Aluminum, nickel or copper may be used as the conductive base material, and acrylic resin, PMMA, or PC may be used as the non-conductive base material.

First, as shown in FIG. 7A, convex patterns 61 extending in parallel in a predetermined direction on the surface of the base material 60 are formed by cutting or the like. At this time, the convex patterns 61 are formed to have the inclination angle, pitch, and the like (step S62).

Referring to FIG. 7B, the photoresist 62 is coated on the entire surface of the base material 60 on which the convex patterns 61 are formed (step S62). At this time, the photoresist 62 is filled only in the concave portions formed in the convex patterns 61 so that the entire surface thereof may form a flat surface.

Next, as shown in FIG. 7C, the photoresist 62 is exposed and developed using the mask 64 having the cell region having a constant size open (step S63).

The developed photoresist is removed as shown in FIG. 7D, and a conductive material layer 66 such as nickel, aluminum, or copper is formed on the entire surface as shown in FIG. 7E (step S64). In this case, when the conductive material is used as the base material 60, the process may be omitted since the base material 60 itself may be used as an electrode to be described later.

In order to form the conductive material layer 66, a resistive heating method, an evaporation drying method, an electron beam method, a vacuum deposition method by sputtering, a chemical vapor deposition method, or an electroless plating method may be used, and preferably formed to a thickness of 10 μm or less. do.

Subsequently, the metal layer 68 is laminated by electroplating a metal material such as nickel on the front surface using the deposited conductive material layer 66 as an electrode as shown in FIG. 7F (step S65). In addition to nickel, metal layers such as aluminum and copper can be formed, for example, formed to a thickness of 0.3 mm.

Subsequently, as shown in FIG. 7G, the photoresist 62 and the base material 60 are peeled off, thereby completing a stamper 70 for manufacturing a light guide plate having a concave pattern.

Meanwhile, a stamper for manufacturing a light guide plate having a convex pattern by electroplating and separating the light guide plate as an electrode on the front surface of the light guide plate having the convex pattern formed through the process of FIG. Can be produced.

In this way, the stamper can be manufactured easily, so that even if the size of the convex or concave pattern or the cell size is changed, the corresponding stamper can be easily manufactured, and the stamper needs only to be installed in the mold. Simplify production.

Although the above has been described with reference to the preferred embodiment of the present invention, various changes and modifications can be made at the level of those skilled in the art.

It is natural that such changes or modifications fall within the scope of the present invention without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limited to the above-described embodiment, but should be determined by the claims described below.

According to the present invention, there is an advantage that the viewing angle of the light emitted to the surface can be controlled by using the inclination angle of the inclined surface constituting the convex pattern or the concave pattern formed on the rear surface of the light guide plate.

By controlling the viewing angle as described above, it is not necessary to add a separate prism sheet or the like to the light guide plate, so that the structure of the backlight unit is simplified and manufacturing cost is low.

Furthermore, according to the present invention, there is an advantage that the brightness can be controlled by controlling the pitch of the convex pattern or the concave pattern or the distribution density or size of the cells formed therefrom.

In addition, according to the method for manufacturing a stamper according to the present invention, the stamper can be easily manufactured, and even if the size of the convex pattern or the concave pattern or the size of the cell is changed, there is an advantage that the corresponding stamper can be easily manufactured.

Claims (16)

In the light guide plate having a light source provided on at least one side, A plurality of cells are dispersedly disposed on the back surface opposite to the surface from which the light emitted from the light source is emitted, Each of the cells is formed with convex patterns extending continuously along the longitudinal direction of the light source and having at least inclined surfaces facing the light source, adjacent to each other at equal intervals, and having the rear surface as a bottom surface. The angle of view of the light guide plate, characterized in that for controlling the viewing angle of the light emitted to the surface by controlling the angle of the inclined surface. In the light guide plate having a light source provided on at least one side, A plurality of cells are dispersedly disposed on the back surface opposite to the surface from which the light emitted from the light source is emitted, Each of the cells has a concave pattern extending continuously along the longitudinal direction of the light source and having at least inclined surfaces facing the light source and adjacent to each other at equal intervals. The angle of view of the light guide plate, characterized in that for controlling the viewing angle of the light emitted to the surface by controlling the angle of the inclined surface. The light guide plate according to claim 1 or 2, wherein convex patterns are formed on the surface of each of the convex patterns continuously extending in parallel to the longitudinal direction of the light source and having inclined surfaces facing each other. The light guide plate according to claim 1 or 2, wherein the inclination angle of the inclined surface has a range of 33 degrees to 47 degrees. The light guide plate of claim 4, wherein the inclination angle of the inclined surface is 43 degrees. The light guide plate according to claim 1 or 2, wherein the cell has a diameter of 0.05 mm to 2 mm. The light guide plate according to claim 1 or 2, wherein the pitch of the convex pattern or the concave pattern has a range of 1 µm to 100 µm. The light guide plate according to claim 1 or 2, wherein the back surface is inclined to become thinner as it moves away from the light source. The light guide plate according to claim 1 or 2, wherein the cross-sectional shape of the convex pattern or the concave pattern is a triangle. The light guide plate according to claim 1 or 2, wherein the amount of light emitted to the surface is controlled by controlling the size of the cell or the distribution density of the cell. The light guide plate of Claim 1 or 2; A light source installed on at least one side of the light guide plate; And And a protective film having a diffusion function stacked on the light guide plate. Forming convex patterns extending in parallel in a first direction on a surface of the conductive base material; Applying a photoresist to recesses formed by the convex patterns on the conductive base material to flatten the entire surface; Exposing and developing the photoresist using a mask in which a cell region having a predetermined size is opened; And Removing the developed photoresist, electroplating a metal material on the front surface with the conductive base material as an electrode, and peeling the base material and the photoresist. Forming convex patterns extending in parallel in a first direction on a surface of the non-conductive base material; Applying a photoresist to a recess formed by the convex patterns on the non-conductive base material to flatten the entire surface; Exposing and developing the photoresist using a mask in which a cell region having a predetermined size is opened; And Removing the developed photoresist and forming a conductive material layer over the entire surface; And a step of separating the stamper having a convex pattern by removing the base material and the photoresist by electroplating a metal material on the front surface using the formed conductive material layer as an electrode. . The method of claim 12 or 13, wherein the conductive material layer is formed by a resistance heating method, an electron beam method, a sputtering vacuum deposition method, a chemical vapor deposition method, or an electroless plating method. The electroplating with a metal material using the stamper as an electrode on the front surface where the convex pattern of the light guide plate stamper manufactured by the manufacturing method according to claim 12 or 13 is formed, and separating the stamper by separating the stamper having a concave pattern formed thereon. The manufacturing method of the light guide plate stamper characterized by the above-mentioned. The method of claim 15, wherein an interfacial separation material is coated on the entire surface of the stamper where the convex pattern is formed.

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