KR100700686B1 - Dot prism film attached light guide panel of LCD and method of fabricating the same - Google Patents

Abstract

The present invention relates to a light guide plate for a liquid crystal display device and a method for manufacturing the same, and a backlight unit of a liquid crystal display device using the same, and more particularly, a light guide plate for a liquid crystal display device having a film having a patterned irregularities formed on its surface and The present invention relates to a manufacturing method and a backlight unit of a liquid crystal display including the light guide plate. The shape of the pattern of the uneven portion transferred to the film may vary depending on the uniformity, the viewing angle, and the luminance of the light guide plate.

LCD, LGP, Film, Patterned Unevenness, Film Attached LGP

Description

Dot prism film attached light guide panel of LCD and method of fabricating the same}

1 is an exploded perspective view showing a conventional LCD backlight unit.

2 is an enlarged cross-sectional view illustrating a conventional dot prism light guide plate.

3 is a cross-sectional view illustrating a light guide plate for a liquid crystal display according to an exemplary embodiment of the present invention.

4A to 4F are cross-sectional views illustrating a method of manufacturing a film-guided light guide plate according to an embodiment of the present invention.

5 is an enlarged cross-sectional view of a film attaching light guide plate according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

400: light guide plate 410: adhesive layer

420: transparent film 430: cured resin layer

500: Light guide plate master / stamp

The present invention relates to a light guide plate for a liquid crystal display device and a method for manufacturing the same, and a backlight unit of a liquid crystal display device using the same, and more particularly, a light guide plate for a liquid crystal display device having a film having a patterned irregularities formed on its surface and It relates to a manufacturing method and a backlight unit of a liquid crystal display device including the light guide plate.

LCD refers to a device that displays a number or an image by applying an electric field when a liquid crystal, which is a liquid and a solid material, is injected between two glass substrates formed of electrodes.

Since the LCD is not a self-light emitting device, it must have a backlight unit as a light source for generating light, and the amount of light transmitted from the panel unit in which liquid crystals are uniformly arranged is generated from the backlight unit. Adjust the to display the image.

1 is an exploded perspective view showing a conventional LCD backlight unit.

However, the backlight unit 10 of the LCD may be classified into a direct type and an edge type according to the position of a light source for emitting light. FIG. 1 shows an edge type.

As shown in FIG. 1, the conventional LCD backlight unit includes a lamp 105, a light guide plate 110, a reflector plate 115, and an optical film, and the optical film includes a diffusion sheet 120, a prism sheet 125, and an optical film. The protective sheet 130 is included.

Lamp 105 may be used as the first light emitting part in the liquid crystal display, there are many types of lamp 105, but generally used lamps in the liquid crystal display CCFL that emits very bright white light with low power consumption (Cold Cathode Fluorescence Lamp) is used.

The light guide plate 110 converts spot light generated from the lamp 105 into plane light to project light onto the front surface of the light guide plate 110.

As described above, in order to improve the brightness and uniformity of the light emitted to the upper surface of the light guide plate, a film having good optical characteristics is generally disposed on the light guide plate. The easiest way to increase brightness is to use brightness-enhancing films or diffusion sheets, but producers are increasingly using expensive films to reduce manufacturing costs.

In order to improve the brightness and uniformity of the light emitted through the light guide plate, a method of applying a predetermined pattern to the upper and lower light guide plates is used. A method of forming an uneven surface having a predetermined shape or pattern designed in consideration of the distance and the like is used (FIG. 2).

Conventional light guide plate pattern applying methods include a process of processing dot printing (printing light guide plate) or embossing pattern (non-printing light guide plate) by a printing method under the light guide plate to improve the uniformity of light. In addition, methods of inducing the effect of increasing luminance by applying a prism pattern or an embossing pattern directly to the upper surface of the light guide plate for removing various films disposed on the light guide plate have been developed. However, although this series of methods have a brightness raising effect, it is not easy to maintain the same brightness after removing the optical film because the value is within 10%.

Korean Patent No. 421289 'Dot Prism Light Guide Plate Master Manufacturing Method' and Korean Patent No. 295505 'Light Guide Plate with Unevenness of Stamping Method Using Photocuring Resin' exhibited improved light output effect as a patterned light guide plate. In light of the trend toward larger and larger display panels, the light guide plates disclosed in the above patents have limitations in the size and mass of the light guide panel, and thus require a new solution.

Accordingly, the present inventors have attempted to develop a light guide plate for a liquid crystal display device and a method of manufacturing the same, including a patterned uneven portion through a simple process without directly processing the uneven portion on the surface of the light guide plate to improve luminance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a light guide plate and a method of manufacturing the same, which are easy to be enlarged and mass-produced and have improved luminance.

Furthermore, this invention is providing the backlight unit for liquid crystal display devices containing the light-guide plate for liquid crystal display devices by this invention.

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

In order to solve the above technical problem, the present invention provides a light guide plate for a liquid crystal display device characterized in that the film formed on the surface of the patterned uneven portion is attached to one or both surfaces of the upper and lower parts of the light guide plate.

The shape of the pattern of the concave-convex portion transferred to the film may vary depending on the uniformity and the viewing angle of the light guide plate, and whether the brightness rises. Preferably, the patterned concave-convex portion has a predetermined concave-convex shape in the dot-shaped first pattern portion. It may include a second pattern portion made of a portion.

The dot as the first pattern portion may have various shapes such as a circle, an ellipse, a rectangle, or a polygon, and the uneven cross section of the second pattern portion may have various shapes such as a triangle or a polygon, such as a polygon or a circle.

The size of the dot, which is the first pattern portion, may range from several hundred μm to several mm, and the height of the unevenness of the second pattern portion may be 1-100 μm, and the unevenness interval may be 1-100 μm.

Moreover, it is more preferable that the height of unevenness | corrugation is 10-30 micrometers, and the uneven | corrugated space | interval is 30-80 micrometers.

In this case, the first pattern portion and the second pattern portion may be a uniform pattern or a variably changed pattern in the longitudinal and horizontal directions of the light guide plate, and may have various pattern periods depending on whether the light guide plate has a uniformity and a rise in the central luminance.

The film is attached to the light guide plate by an adhesive layer including patterned irregularities.

In addition, the present invention provides a backlight unit comprising the above light guide plate for liquid crystal display device. Preferably, the first pattern portion has a circle or ellipse shape, and the second pattern portion has a triangular, square or circular prism pattern with a cross-sectional shape of the unevenness. At this time, the film may be attached to the light guide plate in the forward or reverse direction by the adhesive layer.

In addition, the present invention is to provide a method for manufacturing a film-attached light guide plate with a film including an uneven portion, (a) step of manufacturing a light guide plate master or stamper is formed patterned irregularities having a predetermined shape (b) applying the cured resin to one surface of the transparent film, (c) transferring the unevenness of the master or stamper to the cured resin on the transparent film, (d) irradiating ultraviolet or heat to the cured resin And (e) attaching the film including the uneven portion to the light guide plate using an adhesive, wherein the cured resin is cured.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings and the following embodiments, but the scope of the present invention is not limited thereto, and may be modified by those skilled in the art.

1. Manufacturing Process of Film-Attached Light Guide Plate Master

The manufacturing process of a master for manufacturing a film-attached light guide plate including a patterned uneven portion may use a conventionally known method of manufacturing a light guide plate master for forming the uneven portion at the bottom or the top of the light guide plate. The light guide plate master can be made of either a metal plate or a non-metal plate.

First, the metal plate light guide plate master was machined using a mechanical cutting machine so that the triangular prism irregularities were arranged in a direction perpendicular to the light source. One surface of the light guide plate master was cut so that the height of the uneven surface was 20 µm and the pitch interval of the prism shape was 50 µm.

The prism concave-convex surface (second pattern) may be a polyhedral structure such as a rectangle or a pentagon, or a semi-circular embossing form as well as a triangle as necessary.

As a next step, the cured resin is applied to the PET film with a thickness of several tens of micrometers and then dried to compress the surface on which the cured resin is attached to the light guide plate master surface on which the prism is processed. By hardening the cured resin, a light guide plate master having a dot partial prism pattern was produced.

After plating nickel on the light guide plate master surface having the dot prism pattern thus prepared, a stamper 500 having a dot prism pattern formed thereon was manufactured.

2. Dot prism  Manufacture of film and Dot prism  Manufacture of film-attached light guide plate

The stamper 500 manufactured by the above method was prepared, and the cured resin layer 430 was applied to one surface of the transparent film 420 as shown in FIG. 4B. The transparent film 420 serves as a base layer, and it is desirable to use a material having excellent transparency and transparency. In the present invention, PET (Poly-ethyleneterephthalate) is used.

The cured resin layer 430 may be a general thermosetting resin or UV curable resin, but in the present invention, a urethane acrylate resin is used.

Thereafter, as shown in FIG. 4C, the cured resin layer of the PET film to which the cured resin layer 430 is applied is pressed into the uneven portion of the stamper 500 so that the pattern of the uneven portion of the light guide plate stamper is transferred to the cured resin on the transparent film. After curing, heat was applied to obtain a film on which a dot prism pattern was formed (FIGS. 4D and 4E).

A pressure-sensitive adhesive layer was applied to the entire back surface of the dot prism film to form an adhesive layer 410, and then bonded to one surface of the light guide plate 400 to prepare a light guide plate including a dot prism pattern film layer (FIG. 4F).

As another embodiment according to the present invention, as shown in FIG. 5, the light guide plate may be manufactured by adhering a film having a dot prism pattern formed in the opposite direction to that performed above.

The film including the uneven portion of the predetermined pattern may be attached to one surface of the upper or lower portion of the light guide plate in the forward or reverse direction as described above, or may be attached to both upper and lower surfaces of the light guide plate according to the embodiment.

In manufacturing the film-attached light guide plate as described above, it is possible to manufacture a backlight unit that does not require an optical film by adjusting the size and arrangement of the dot prism appropriately according to the uniformity and brightness of the light guide plate by adjusting the pattern of the uneven portion of the dot prism formed on the film. Could.

In addition, the manufacturing of the liquid crystal display device using the film-attached dot prism light guide plate according to the present invention can be easily carried out by those skilled in the art.

Conventional LGPs, which directly impart a dot prism pattern or an embossing pattern to the upper or lower surface of the LGP, exhibit excellent light condensing efficiency, but have a lot of limitations in the production process due to low production cost and productivity in the production of LGPs used in large LCD screens. . However, the film-attached light guide plate according to the present invention is an additional process due to the larger size and mass production than the case where a dot prism pattern is directly formed on the light guide plate to produce a large light guide plate for a liquid crystal display device having excellent brightness and uniformity. This cost can be reduced even further, so there are economic and process advantages.

Claims (14)

A light guide plate for a liquid crystal display device, wherein a film including a second pattern portion made of a predetermined concave-convex portion in a dot-shaped first pattern portion is attached to one or both upper and lower portions of the light guide plate by an adhesive layer. delete The method of claim 1, The first pattern portion dot is a light guide plate for a liquid crystal device, characterized in that the shape of a circle, ellipse, square or polygon. The method of claim 1, Light guide plate, characterized in that the cross-section of the uneven portion of the second pattern portion is triangular, square, polygonal or circular. A light guide plate for a liquid crystal device with a film on which one or both of upper and lower portions of a light guide plate are formed, on the surface of which a dot-prism shaped concave-convex portion including a second pattern portion made of a concave-convex portion in a dot-shaped first pattern portion is formed on a surface thereof. delete The method according to any one of claims 1 and 3 to 5, The height of the unevenness of the second pattern portion is a light guide plate for a liquid crystal display device, characterized in that 1 ~ 100㎛. The method according to any one of claims 1 and 3 to 5, The unevenness interval of the second pattern portion is 1 ~ 100㎛ light guide plate for a liquid crystal display device. The method according to any one of claims 1 and 3 to 5, Wherein the first pattern portion and the second pattern portion are a uniform pattern or a variable pattern in the longitudinal and horizontal directions of the light guide plate. The light guide plate of claim 1; And And a light source disposed on one side or both sides of the light guide plate. A light guide plate, which is attached to one or both surfaces of a liquid crystal display light guide plate, has a dot prism-shaped concave-convex portion including a second pattern portion formed of a predetermined concave-convex portion in the dot-shaped first pattern portion. Transparent film for adhesion. The method of claim 11, The first pattern portion is a transparent film for light guide plate attachment, characterized in that it has a shape of circle, ellipse, square or polygon. The method of claim 11, Cross section of the uneven portion of the second pattern portion is a transparent film for light guide plate attachment, characterized in that triangular, square, polygonal or circular. (a) manufacturing a light guide plate master having patterned irregularities having a predetermined shape formed on a surface thereof; (b) applying a cured resin layer on one surface of the transparent film; (c) transferring the patterned irregularities of the master to the cured resin layer on the transparent film; (d) curing the cured resin by irradiating ultraviolet or heat to the cured resin layer of the transparent film; (e) a method of manufacturing a light guide plate for a liquid crystal display device comprising attaching the transparent film formed on the surface of patterned irregularities to one or both surfaces of the light guide plate using an adhesive.

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