KR101671036B1 - Light guide film - Google Patents

Abstract

The present invention relates to a light guide plate for a flat panel display, and more particularly to a light guide plate for an LCD panel, which comprises a first surface for outputting light; A second surface opposite the first surface and having a lenticular pattern formed thereon; And an incident surface that extends between the edge of the first surface and the edge of the second surface and into which the light enters. The body of the light guide plate is in the form of a film, and the film is preferably flexible. The film may comprise a substrate layer and the substrate layer may support a separate lenticular layer that forms a lenticular pattern wherein long lenticular lenses may be arranged in parallel in the lenticular layer, The height and width of the lenses can be the same. On the other hand, some lenticular lenses may have the same or different spacing. These lenticular lenses may have a convex surface protruding from the body, wherein the convex surface should coincide with a portion of the surface of the cylinder.

Description

LIGHT GUIDE FILM

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate for a flat panel display, and more particularly to a light guide plate for an LCD panel.

The liquid crystal layer (LC layer) of the LCD panel does not emit light as compared with the electroluminescent material layer of the plasma display panel. The LC layer functions to modulate the light passing through it. The backlight module of the backlit LCD panel serves as a flat light source, which is an important element of the LCD panel and is important for increasing the brightness. The backlight module includes a light guide plate for guiding light of a linear light source such as a flat plate of an LED, a cold cathode ray tube, or an LED array. A backlight module having a linear light source is referred to as an edge type backlight module in the art.

The conventional light guide plate installed in the edge type backlight module uses total reflection to direct light from the light source located on the edge surface of the light guide plate to the exit surface facing the LC panel. The light from the light source is propagated through the light guide plate to the opposite edge, and then directed to the LC panel through the plane. In the past, a structure that reflects light well onto the upper flat surface was formed on the surface opposite to the exit surface of the light guide plate. For example, in a conventional light guide plate, a reflection layer is provided on the bottom surface to reflect light back to the light guide plate. Other conventional light guide plates formed a structure for reflecting or scattering light on the bottom surface opposite to the exit surface. The light striking the tissue is diffused or reflected toward the exit surface of the light guide plate. Specifically, a protrusion for reflecting or scattering light is formed on the bottom surface of a conventional light guide plate so that light is dispersed across a flat exit surface from a linear power source by changing the propagation direction of light, . The diffusive reflecting surface on which protrusions for reflecting or scattering light are formed generally has a mat shape by the manufacturing process. Therefore, a considerable amount of energy is required to output light in a planar shape that produces a proper luminance in a point-like or linear light source, and the power consumption is considerable.

Techniques using a V-cut light guide plate have also been developed. The V-cut light guiding plate has a microstructure prism directly formed on the light guide plate, and is used for a backlight module together with a reverse prism sheet. The conventional backlight module shown in Fig. 1 includes a reverse prism sheet 3, a tapered V-cut light guide plate 2, a reflective film 1 under the reverse prism sheet, and a diffusion film 4 on the reverse prism sheet do. An LC panel (not shown) is placed on the diffusion film 4. The linear light source / reflector 5 is arranged at the edge of the light guide plate 2. Compared to the previous backlight module, the brightness of the backlight module with V-cut light guide plate is improved to almost 30%. Therefore, the total power consumption required to achieve a specific output luminance can be reduced to 1/3, and a considerable energy saving effect can be expected.

The light guide plate used for the backlight module is usually manufactured by injection molding. Generally, a molten PMMA (polymethylmethacrylate) material is filled in a mold and pressure is applied, followed by cooling and curing to match the shape of the mold. However, with regard to the V-cut light guide plate, the defect rate is very high due to the difficulty in producing the mold and the above-described characteristics of the injection molding process. Mold master with V-cut structure made by CNC precision machining is difficult to reproduce and defect rate is high. Therefore, the V-cut light guide plate is difficult to manufacture and requires a large cost.

Further, as the LCD device becomes lighter, thinner, and more flexible, the problem of the conventional light guide plate becomes more noticeable. Due to the limitation of the injection molding method, it is not easy to make a thin and flexible light guide plate by this method. In particular, as the LCD panel becomes larger, the defect rate becomes higher.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight light guide plate which has a thin and flexible structure and is effective for a flat light output and is easy to manufacture with a high yield. The flexible light guide plate of the present invention has a light control structure in which a microstructure of a lenticular shape is formed on a bottom surface (opposite to the liquid crystal panel).

To achieve the above object, the present invention provides a light emitting device comprising: a first surface for outputting light; A second surface opposite the first surface and having a lenticular pattern formed thereon; And an incident surface that extends between an edge of the first surface and an edge of the second surface and into which light enters. The body of the light guide plate is in the form of a film, and the film is preferably flexible. The film may comprise a substrate layer and the substrate layer may support a separate lenticular layer that forms a lenticular pattern wherein long lenticular lenses may be arranged in parallel in the lenticular layer, The height and width of the lenses can be the same. On the other hand, some lenticular lenses may have the same or different spacing. These lenticular lenses may have a convex surface protruding from the body, wherein the convex surface should coincide with a portion of the surface of the cylinder.

On the other hand, the second surface is divided into a plurality of areas, each area is formed of a lenticular lens group, and the configuration of each group of lenticular lenses may be different from that of the adjacent group of lenticular lenses. In this case A plurality of regions extend from a first edge of the body adjacent to the entrance surface to a second edge opposite the first edge and the spacing of adjacent lenticular lenses in each group may become increasingly narrower from the first edge to the second edge .

On the other hand, the first surface may have a micro concavo-convex structure, and the micro concavo-convex structure may be a prism structure.

The present invention also relates to a light guide plate as described above; And a light source disposed adjacent to an incident surface of the light guide plate.

Also, such a backlight module; And a light modulator receiving and modulating light emitted from the first surface of the light guide plate to be output by the light modulation module according to the image data. At this time, the light modulation module includes a planar light modulation module and an LC module.

The present invention also relates to such a display device; And a controller for sending image data to the display device so that the image is displayed in accordance with the image data.

The present invention also provides a method comprising: providing a film having a first surface and a second surface opposite the first surface; Providing lenticular patterns on the surface; And providing an incidence surface extending between an edge of the first surface and an edge of the second surface. At this time, the film includes a substrate layer for supporting a lenticular layer forming a lenticular pattern, and a lenticular layer may be formed and adhered to the substrate layer to provide a lenticular pattern on the second surface.

1 is an exploded perspective view showing a prism structure of a conventional light guide plate;
2 is a sectional view showing the structure of a backlight LCD device provided with a light guide plate according to the present invention;
3 is a schematic view comparing the surface shapes of a prism and a lenticular lens;
4 is a perspective view of another light guide plate according to the present invention;
5 is a perspective view of another light guide plate according to the present invention;
FIG. 6A is a plan view of a bottom surface of another light guiding film according to the present invention, FIG. 6B is a perspective view of an oval portion of FIG. 6A;
7 is an xz plan sectional view for explaining structural factors of the light guide film;
8 is a schematic view of an electronic apparatus having an LCD panel provided with a light guide plate of the present invention.

2 is a cross-sectional view showing the structure of a backlight LCD device provided with a light guide plate according to the present invention. The backlight LCD 10 includes an LC module 12, a backlight module 14 in the form of a flat light source, and a plurality of optical films between the LC module 12 and the backlight module 14. The LC module 12 includes liquid crystals arranged between two transparent substrates and a control circuit constituting a two-dimensional pixel array. The backlight module 14 is an edge type in which light is dispersed in a plane, and a linear light source 16 in the form of a long cold cathode fluorescent lamp tube in which LEDs are dispersed in a line or the like is disposed at the edge of the light guide film 18. The reflector 17 is installed so that the light emitted from the light source 16 enters the light guide plate 18 through the edge of the light guide film 18. The LC module 12 modulates the backlight incident through the module according to the image data. Although the present invention has been described by taking an LC module as an example of an optical modulator, the light guide film of the present invention can also be used in other modulators for modulating incident light.

More specifically, the present invention relates to a new structure of a thin and flexible light guide film having a light control structure for changing the light path. In one example, a first optical layer of a flexible transparent material supports a second optical layer underneath and has a light control structure, and the refractive indexes of the first and second optical layers may be equal to or different from each other. The light guiding film 18 includes a transparent and flexible substrate 19 and the substrate 19 supports a transparent light control layer 20. The light control layer includes a structure in which a plurality of lenticular lenses 21 are arranged side by side to be. A light control layer 20 is formed on the surface of the flat light guiding film 18 opposite to the LC module 12 in order to uniformly distribute the light through a flat upper surface toward the LC module 12. A reflector (22) is disposed to reflect light to the bottom of the light guide film (18) toward the light guide plate (18).

In this embodiment, there are two concave-convex microprism substrates 26 and 28, which are arranged such that the prism structures are orthogonal to each other. The micro prism substrates 26 and 28 align light so as to close the vertical optical axis while increasing the brightness. A diffusion plate 27 is usually disposed between the light guide film 18 and the lower microprism substrate 28. On the other hand, a diffusion structure may be formed on the bottom surface of the substrate facing the light guide plate. In this case, the light can be diffused while being aimed, and a separate diffusion plate is unnecessary, and the entire thickness of the LCD 10 can be reduced. This is further described in U.S. Patent Application No. 13 / 073,859, filed March 28, 2011, by the present applicant.

The light entering the LC module 12 through the optical films shown in FIG. 2 is incident on the LC module 12 relatively uniformly while being distributed uniformly over the entire surface of the LC module.

The optical substrates of the present invention are used in a display device in which a panel array is arranged while the panel is flat, curved, rigid or flexible. The planar light source is a light source that provides illumination covering the display pixel array region. Accordingly, in the case of a display panel in which the image plane is curved, whether flexible or rigid, the curved display pixel array is covered with a backlight to effectively illuminate the curved image plane.

The uneven surface of the lenticular structure will be described later in detail. For convenience of explanation, the following description will be made using the Cartesian coordinate system of x, y and z. In the embodiment of FIG. 2, the x-axis is a direction transverse to the lenticular lens 21, and the y-axis is the direction of the light guide film 18 orthogonal to the x-axis and the longitudinal direction of the lenticular lens 21. The longitudinal direction of the lenticular lens is from one end of the lens to the other end. From the viewpoint of the light guide film 18, the x-axis and the y-axis coincide with the two edges of the light guide plate 18 which are perpendicular to each other. The x-axis is orthogonal to both the x-axis and the y-axis. As shown in Fig. 2, the cross section of the lenticular lens 21 arranged side by side is in the x-z plane. That is, the cross-section of the lenticular lens 21 is a cross-section taken along the y-direction at various positions in the x-z plane. In the figure, the horizontal plane is the x-y plane, perpendicular to the z-axis.

The lenticular uneven surface has a wave lens structure in which a concave lens or a convex lens is disposed, or a concave lens and a convex lens are combined. In the case of Fig. 2, the convex lenticular lenses 21 are arranged in parallel in the lenticular uneven surface, and each lens extends in the y direction between both edges of the light guide film 18. These lenticular lenses may be concave lenses as opposed to those shown. In the illustrated embodiment, the lenticular lenses 21 do not extend to each other, so that grooves 24 parallel to each other between the lenses are formed, and the bottom surface of the grooves is flat. However, in some cases, the lenticular lenses may be attached to each other. With respect to the lenticular lens 21, the x axis is the transverse direction of the lenticular uneven surface in the direction crossing the grooves and the lens. The y-axis is the longitudinal axis direction of the lenticular lens 21 and the groove 24 in the longitudinal direction. In Fig. 2, the lenticular lenses 21 are in the x-y plane, and the cross-section of the lens is in the x-z plane.

7 is an x-z plane cross-sectional view for explaining structural factors of the light guide film. The light guide film 500 includes a single substrate layer 510 and a plurality of lenticular lenses 520 formed on the bottom surface of the substrate layer 510 to form a convex surface 524. The surface 524 of each of the lenticular lenses 520 corresponds to a portion of the flattened surface of the cylinder 522 having the center "O" and the radius "a ", and its cross section is a cross section of the angle? In Fig. 7, lens 520 is a portion of circle 522, i. E., A portion of a circle consisting of a-b and a-b. The adjacent convex surfaces 524 do not extend to each other. As will be described later in connection with FIG. 6, the arcuate surfaces of some lenticular lenses may intersect with each other. The surface 524 of the lens 520 forms the upper surface of the substrate layer 510, and the gap between the lenses is flat. The width d1 of the lens is the same, and the interval pitch d2 is constant in a specific area, but is different in other areas.

The angle &thetas; of the lenticule structure is usually 5 DEG to 90 DEG, more preferably 10 DEG to 45 DEG. When the substrate layer is integrated with the lenticular lens, the height d3 of the lens measured from the surface between the lenses is preferably 0.5 to 100 占 퐉, preferably 1 to 60 占 퐉, More preferably 1 to 45 mu m, and in some cases, d3 may not be constant. The curvature of the lenticular lens is the same. The distance between the centers of the adjacent lenses (i.e., d1 + d2) is 5 to 1000 占 퐉.

In the embodiment of Fig. 2, the lenticular lenses 21 all have the same cross-sectional shape in the y-z plane. The cross-sectional plane of the lenticular lens 21 is a cross-section taken in the y-z plane at various positions along the x-axis. The horizontal direction is the x-y plane, and the vertical direction is the z direction. Here, the curvature and height of the lenticular lens 21 are the same for all lenses, and the pitch between the two lenses is also the same. The surface of each lens 21 forms a bottom surface facing the top surface of the substrate layer 19. [ The lenses of FIG. 2 are arranged at intervals on the substrate layer 19, but may be connected to each other (see FIG. 4). The overall structure of this lenticular lens 21 resembles a lenticular lens layer supported on a thin base layer of desired height to hold the substrate layer 19. [

The cross section of the lenticular lens 21 is a part of the circle, specifically, a part of the cylinder. On the other hand, it may take the form of an ellipse, not a circle, or a portion of a cylinder of another cross-section of regular or irregular geometric shape.

2, the light guide film 18 has two layers of a flexible substrate layer 19 and a concave-convex type light control layer 20. The light control layer 20 is adhered to the substrate layer 19 to form the entire light guiding film 18. [ On the other hand, the light guide film 18 may be integrally formed as a single layer. The light guide film 18 may have a monolithic structure having a base for supporting the structure of the lenticular lens 21. [

The lenticular structure helps guide the light toward the upper exit surface of the light guide film 18, thereby helping improve the brightness of the LC module 12. [ Light emerging from the light source 16 along the optical path L of FIG. 2 enters the lenticular lens 21 through the substrate layer 19, and the first reflection occurs. When the light passes through the layer of the lenticular lens 21, the lenticular lens changes the optical path. Then, the light passes through the substrate layer 19 and is directed to the upper surface of the substrate layer and the upper surface of the light guide film 18. Finally, the light comes out of the upper surface of the light guide film 18. A planar light source is formed by the light guide film 18.

The optical path L of the thin and flexible light guiding film 18 of the present invention can control the refractive index between the substrate layer 19 and the lenticular lanthanum 21 and can control the refractive index of the lenticular lanthanum 21 And the reflectance can be adjusted. Compared to the conventional V-type light guide plate described in the background art, the present invention simplifies the design of the light control concave and convex surface because the requirement of the precision processing technology of the lenticular lens is relatively low to improve the yield of the light guide film 18 to be.

The light control structure of the light guide film 18 is a regular or irregular lenticular type structure. The effect of improving the light control structure of the light guide film 18 of the present invention compared to the prism structure of the conventional light guide plate 2 of FIG. 1 will be described with reference to FIG. As shown in Fig. 3, the upper inverted triangle represents the cross-sectional shape of the prism structure of the light guide plate 2 of Fig. The lower lens is a cross-sectional shape of the lenticular lens 21 of the light guide film 18. The broken lines T _P and T _L represent the slopes of the various surface sections of the bottom surface of each cross-sectional shape. As shown in FIG. 3, since the slope T _P of the prism-type light guide plate 2 is constant, it is difficult to design and manufacture the total internal reflection (TIR) and the level of reoriented light. On the other hand, in the case of the lenticular lens 21, the slope T _L of the tangent line changes from position to position across the convex surface of the lens 21. This break TIR level makes it much easier to design and manufacture. The degree of freedom of design is greatly increased in consideration of the tangential effect which varies according to the break of the TIR, and the tangential change can be controlled by changing the size or shape of the lenticular lens. For example, the break level of total reflection can be adjusted through (a) the distance between two adjacent lenses 21 or (b) the radius of curvature of the range 21. If the lenticular structure is adopted as the light control structure of the present invention, the design flexibility becomes greater.

The layer made of the lenticular lens 21 and the material of the substrate layer 19 may be the same or different and both may be made of a transparent material, preferably a polymerizable resin such as a resin or an adhesive which is cured to ultraviolet rays or visible light . The light guide film 18 can be manufactured by coating or embossing a rolled-up rolled sheet material of double-side or cross-sectional shape depending on whether the both sides or one side should be concave and convex. In general, a concavo-convex lenticular surface is formed by coating a master mold or a master drum with a composition containing a polymerizable crosslinking resin and then curing. The lenticular structure may also be formed in a separate base film by a device such as a die assembly, a press rolling machine, or a mold pressing assembly. The base film which is the light control layer 20 of the lenticular lens 21 is bonded to the flexible substrate layer 19 by simply laminating the two layers or bonding them with an adhesive such as a pressure sensitive adhesive to form the light guide film 18 can do. Those skilled in the art will be able to take a concave-convex lenticular surface and a substrate layer structure by appropriately combining various techniques in addition to this. It is also within the scope of the present invention to first make the light guide film 18 thin and then to bond it to another thicker substrate by using the above-described assembling process to form a thick light guide plate.

As described above, since most of the V-cut light guide plates are formed by injection molding, the refractive index of the prism structure on the bottom surface opposite to the LC module is equal to the refractive index of the base substrate. In order to effectively guide light along the light path, Should be designed to accommodate for example angle, width or depth. On the other hand, in the case of the thin and flexible light-guiding film of the present invention, the light control layer 20 is formed on the substrate layer 19 by a coating method, and the refractive indexes of the two layers are different from each other, You can adjust the light path to guide as you want. In the present invention, the absolute value of the refractive index difference between the two layers is 0.001 to 0.6.

On the other hand, the substrate layer 19 and the lenticular lens 21 may be formed integrally with a thick transparent film plate by molding, pressing, embossing, calendering, extrusion or the like. Regarding the step of forming a substrate having an uneven surface, refer to U.S. Patent No. 7,618,164 referred to in the present invention.

Examples of the flexible transparent material that fits the substrate layer 19 of the thin and flexible light guide film 18 include polyesters such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate); Polyacrylates such as PMMA (polymethylmethacrylate); Polyimide; Polyolefins such as PE (polyethylene) and PP (polypropylene); Polycycloolefins; Polycarbonate; Polyurethane; Polyvinyls such as PVA (polyvinyl alcohol) and PVC (polyvinyl chloride); TAC (triacetate cellulose); Or mixtures thereof, but are not limited thereto. As an example, PMMA may be suitable as the substrate. Likewise, the lenticular lens 21 may also use materials similar to the substrate layer 19, such as acrylic resin suitable for bonding to the substrate layer, or other transparent materials well known in the art.

The thickness of the substrate layer 19 is constant and both surfaces are always parallel, specifically 100 to 800 mu m, preferably 125 to 600 mu m. On the other hand, the substrate layer 19 may be tapered so as to become thinner toward the opposite side from the side where the light is incident. The thickness of the lenticular lens layer 21 and the thickness of the lenticular lens itself are 0.5 to 100 占 퐉, preferably 1 to 60 占 퐉, more preferably 1 to 45 占 퐉.

In the embodiment of Figs. 2 and 7, the vertical height d3 of the lenticular lens 21 is the same and is 0.5 to 100 占 퐉, preferably 1 to 60 占 퐉, more preferably 1 to 45 占 퐉. The osculating ratio of the lens is also the same. The distance d1 between adjacent lenses is 0 to 1000 mu m, and the width d2 which is a distance between both edges of the convex surface of the lens is 0 to 1000 mu m. The center distance (i.e., d1 + d2) of the adjacent lenses is 3 to 1200 mu m. When a thin base film (web) is integrated with the lenticular lances 21 as in the base film 42 of Fig. 4, the thickness of the base film may be 5 to 800 mu m.

On the other hand, it is also within the scope of the present invention that the lenticular lens surface is coated with beads or the particles are built-in.

4 to 5 are perspective views of another type light guide film in which a prism and a lenticular structure are combined on both sides of a substrate.

The light guide film 48 of FIG. 4 has a structure in which a prism and a lenticular structure are coupled to both sides of the substrate layer 49. Specifically, the light guide film 48 has a concave-convex lenticular layer 40 and a concavo-convex prism surface 44. The lenticular lens 41 has a structure similar to that of the lenticular lens 21 described above, but has a structure in which a thin base film 42 is integrated with a convex lens of the lenticular layer 40. The spacing d1, the width d2, and the height d3 of the lenticular lances 41 are constant, but two of the lenticular lances 41 may be constant across the light guide film, one may be fluctuating, one may be constant and two may be fluctuating.

The irregular prism surface 44 is an exit surface that improves the brightness along the orthogonal viewing axis (i.e., improves light aiming), and the lenticular layer 40 is the light control surface. As shown in FIG. 4, a plurality of elongated prisms 45 are arranged side by side between both edges of the substrate layer 49 on the prism surface 44. These prisms 45 are arranged side by side to form a peak 46 and a valley 47. The cross-sectional shape of the peak 46 is symmetrical about a vertical line as viewed in the y-z plane. The peak apex angle may be orthogonal and the peaks and valleys may be constant or similar throughout the prism surface 44. The pitch of the peak / valley is constant in the embodiment of Fig. Although the uneven prism surface 45 and the lenticular surface 40 are generally parallel to each other through the light guide film as a whole, they may be tapered like the light guide plate of the backlight module. The height of the prism may change in the longitudinal direction or the lateral direction through the entire surface of the light guide film. The adjacent prisms may fall without contacting each other. 4, the longitudinal axis of the lenticular lens 41 (in the y-axis direction) is orthogonal to the longitudinal axis of the prism 45 (in the x-axis direction).

The double-sided light guiding film 48 of Fig. 4 is produced by coating or embossing both sides of the rolled sheet by a rolling process, similar to the above-described process. One or both of the lenticular surface 40 and the prism surface 44 may be fabricated as a separate layer from the substrate layer 49 or integral with the substrate layer. 4, the prism layer 44, the substrate layer 49, and the lenticular layer 40 are separately formed. It is also possible to form the light guide film 48 as a single single layer by forming the light guide film 48 by bonding the prism layer 44 and the lenticular layer 40 to the substrate layer 49 . The light guide film 48 may be a monolithic structure including a base portion for supporting the surface structures of the prism 45 and the lenticular lens 41. [

The light guide film 58 of Fig. 5 also has a structure in which prisms and lenticular structures are combined on both surfaces. Concave and convex lenticular layers 50 and prism layers 54 are formed on both sides of the light guide film 58. The lenticular layer 50 is formed on the thin base film 52 by a plurality of convex lenses (51) are integrated with each other. The structure of the lenticular lens is as described above, but the interval d1 of the lenses is variable or different along the x direction. The width d2 of the lens is constant. The height of the lens measured on the upper surface of the base film 52 is the same.

In the prism layer 54, a plurality of elongated prisms 55 are arranged in parallel. The double-sided light guiding film 58 of Fig. 5 is fabricated similarly to the above. 5, the vertical axis (in the y-axis direction) of the lenticular lens 51 is orthogonal to the vertical axis (in the x-axis direction) of the prism 55. [

In addition to the prisms 44 and 54 described above, beads or particles may be coated or built-in on the exit surface of the light guide film.

On the other hand, the vertical height of the lenticular lens may be variable, the radius of curvature of each lenticular lens may be variable, and the surface of the lens may have an elliptical shape or other regular or irregular shape instead of a circular shape, May also be variable. It is also possible that the long lenticular structure has a constant sectional area but a different convex surface shape. For example, the shape of each lens can be the same or different.

Experiment result

Various experiments were conducted to determine the influence of the fluctuation of the dimension of the lenticular lens on the uniformity of the luminance distribution of the light guide film of the present invention.

The light guide film 180 of Fig. 6 has a diagonal length of about 10.1 inches and was formed of a transparent material such as acrylic resin. FIG. 6A is a plan view of the bottom surface of the light guide film 180, and FIG. 6B is a perspective view of the elliptical portion of FIG. 6A. The light source 150 is on one side of the light guide film 180. The bottom surface 190 of the light guide film 180 was divided into fourteen regions ranging from region A to region N about 10 cm in width. A plurality of lenticular lens patterns 205 are formed on the bottom surface 180 of the light guide film 180 (opposite to the LC module) in the respective regions A to N in parallel to the light source 150, So that the intervals of the lenses are the same and constant but may not be. In this embodiment, the width d2 and height d3 of the lens are the same and constant, and some lenticular lenses do not overlap each other (e.g., closer to the A region). In FIG. 6, the arcuate surfaces of some lenticular lenses may overlap each other (e.g., closer to the N region).

Table 1 shows the initial design dimensions of the light guide film 180. As shown in the table, the variables d2, d3, and R are constant, and d1 varies from A to N regions. The uniformity of the light output in this light guiding film design is not ideal; For example, according to the "13-point" adopted at the factory, the uniformity of the luminance distribution is only 30%.

domain A B C D E F G H I J K L M N d1 + d2 (占 퐉) 503 490 469 441 406 324 287 240 208 178 151 125 117 105 d2 (占 퐉) 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 69.5 d3 (占 퐉) 3 3 3 3 3 3 3 3 3 3 3 3 3 3 R (탆) 200 200 200 200 200 200 200 200 200 200 200 200 200 200

It has been found that the luminance uniformity of the light guiding film is improved up to 75% from the diffusion due to the internal reflection if the R value is kept constant in all 14 regions while increasing the radius of curvature R (d2 value is also increased to R). (d1 + d2) and the height d3 of the lens were fixed, the design of the light guide film was further optimized, and the luminance uniformity increased from 30% to 40%.

To increase the degree of design freedom, you can change the combination of variables. (d1 + d2) and R values, we can further adjust d2 and d3 and increase the luminance uniformity from 40% to 68%. (d1 + d2) value and d3 value, and we can increase the luminance uniformity to 75% or more by using this relation.

By using the structure of the light guide film described above, it is possible to more evenly distribute the luminance over the LCD display area. 2, the light guide film 18 can be surrounded by a reflective member such as the reflection plate 22. [ This reflector collects the light from the light guide film 18 and reflects it back to the light guide film. Through this optical recycling function, the brightness of the backlight module 14 can be maximized.

According to the present invention, for example, the light guide film 18 of FIG. 2 can form a concave-convex lenticular light adjustment surface, and can disperse light over the entire surface when used, for example, in an LCD. The LCD using the optical substrate according to the present invention can also be used in electronic equipment.

The optical substrate according to the present invention can be used in LCDs such as a TV, a notebook computer, a monitor, a mobile phone, a digital camera, and a PDA, thereby further enhancing brightness.

FIG. 18 shows an example in which the backlight LCD 10 according to the present invention is applied to an electronic device 110 such as a PDA, a mobile phone, a TV, a monitor, a portable computer, and a refrigerator. The LCD 10 is provided with the light guide film of the present invention described above. The electronic device 110 includes a user input interface 116, a controller 112 for controlling image data to be managed by the LCD 10, a data storage device including a processor, an A / D converter, 118, and a power supply 114, such as a battery or a jack for an external power supply, which are well known.

Although the present invention has been described by taking the above LCD as an example, the present invention can be applied to other devices. The light guide plate of the present invention takes the form of a film, a sheet, a plate, or the like, is flexible or rigid, and can have a prism-like concave-convex surface on the opposite side as well as a lenticular-

Claims (22)

A light guide plate comprising a body having a first surface, a second surface opposite the first surface, and a side connecting the first surface and the second surface, wherein:
A plurality of light control protrusions extending from a first edge of the second surface to a second edge opposite the first edge, the second surface being convex-concave;
A gap is formed between two adjacent light control projections of the plurality of light control projections;
Wherein a plurality of light control protrusions reflect light so as to output light received from the side toward a first surface of the body through a plurality of light control protrusions. The light guide plate according to claim 1, wherein the body includes a substrate, and a concavo-convex layer disposed on the substrate to form a plurality of light control protrusions. The light guide plate according to claim 2, wherein the material of the substrate and the uneven layer is the same. The light guide plate according to claim 2, wherein the material of the substrate and the uneven layer are different from each other. 3. The light guide plate according to claim 2, wherein refractive indices of the substrate and the uneven layer are different from each other. The light guide plate according to claim 1, wherein the plurality of light control protrusions have the same height. The light guide plate according to claim 1, wherein the plurality of light control protrusions have the same width. The light guide plate according to claim 1, wherein at least a part of the plurality of light control protrusions have the same interval between adjacent ones. The light guide plate according to claim 1, wherein at least a part of the plurality of light adjusting protrusions has a different interval from each other. The light guide plate according to claim 5, wherein each of the plurality of light adjustment protrusions has a convex surface extending from a reference surface formed at the gap. The light guide plate according to claim 10, wherein the convex surface coincides with a part of the surface of the cylinder. The light guide plate according to claim 5, wherein a difference in refractive index between the substrate and the uneven layer is in the range of 0.001 to 0.6. 2. The light guide plate according to claim 1, wherein a distance between adjacent light control protrusions gradually becomes narrower as the distance from the side surface becomes smaller. The light guide plate according to claim 5, wherein the first surface has a micro concavo-convex structure. 15. The light guide plate according to claim 14, wherein the micro concavo-convex structure includes a prism structure. A light guide plate according to claim 1; And
And a light source disposed adjacent to a side surface of the light guide plate. A backlight module according to claim 16; And
And an optical modulator for receiving and modulating the light from the first surface of the light guide plate to be output by the light modulation module according to the image data. 18. The display device according to claim 17, wherein the light modulation module includes a planar light modulation module. The light guide plate according to claim 1, wherein each of the plurality of light adjustment protrusions protrudes higher than the gap. A display device according to claim 17; And
And a controller for sending image data to the display device so that the image is displayed in accordance with the image data. The light guide plate according to claim 1, wherein each of the plurality of light control protrusions is a lenticular lens. The light guide plate according to claim 1, wherein the gap is flat.

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