KR20060051190A - Light guide panel for lcd back light unit and lcd back light unit thereby - Google Patents

Abstract

The present invention relates to a light guide plate for a liquid crystal display device backlight unit excellent in brightness, uniformity and visibility. The light guide plate of the present invention is disposed so as to have a predetermined plane separation distance from each other on the front side and the body part including the front side and the rear side which are connected to the side and side to which the light is incident and emit light. The front prisms having various cross-sectional shapes, and the prism having a predetermined cross-sectional shape are formed on the surface of the front prism and the rear surface at regular intervals to each other, and the farther from the light incident side, It includes dot prisms having a pattern of increasing size. In addition, the present invention also provides a backlight unit for a liquid crystal display device including the light guide plate.

LCD, LGP, Dot Prism, Front Prism

Description

Light guide panel for backlight unit for liquid crystal display device and backlight unit for liquid crystal display device using same {{Light guide panel for LCD back light unit and LCD back light unit}}

1 is an exploded perspective view illustrating a backlight unit of a conventional liquid crystal display device.

2A and 2B are enlarged cross-sectional views of a light guide plate for explaining a process of progressing light generated from a light source in the light guide plate.

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

4A to 4B are perspective views illustrating various embodiments of cross-sectional shapes of the front prisms.

FIG. 5 is an enlarged cross-sectional view in which each dot prism is enlarged in FIG. 3.

6A-6D illustrate embodiments of the shape of each of the dot prisms.

7A to 7C are plan views seen from the bottom of the body portion to show the arrangement of the dot prisms.

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

10: backlight unit

100: panel 110: light guide plate

115: reflector 120: diffusion sheet

125: prism sheet 130: protective sheet

300: body portion 301: side

303: front surface 305: rear surface

306: light source 310: front prisms

320: dot prisms 322: prism

The present invention relates to a light guide plate for a liquid crystal display device backlight unit and a backlight unit for a liquid crystal display device using the same. More particularly, a liquid crystal capable of increasing brightness and uniformity of light by forming prisms and dot prisms on the front and rear surfaces thereof, respectively. A light guide plate for a display device backlight unit and a backlight unit for a liquid crystal display device using the same.

In general, a liquid crystal display device refers to a device in which a liquid crystal, which is a liquid and a solid intermediate material, is injected between two glass substrates formed of electrodes to display a number or an image by applying an electric field.

Since the liquid crystal display device is not a self-luminous device, it must have a back light unit as a light source for generating light, and the light generated from the backlight unit is used in a panel unit in which liquid crystals are constantly arranged. An image or the like is displayed while adjusting the amount of light transmitted.

1 is an exploded perspective view illustrating a backlight unit of a conventional liquid crystal display device.

However, the backlight unit 10 of the liquid crystal display device has a direct light source under which the light source is located directly below the panel 100 of the liquid crystal display device according to the position of the light source that emits light, and a light source on the side surface of the liquid crystal display panel 100. This edge type can be divided into (edge type), Figure 1 shows the edge type.

As shown in FIG. 1, a conventional LCD backlight unit includes a light source 105, a light guide plate 110, a reflector plate 115, a diffusion sheet 120, a prism sheet 125, and a protection sheet 130.

Although the light source 105 has various kinds of light sources 105 that can be used as the first light emitting part in the liquid crystal display device, in general, the light source used in the liquid crystal display device has a low power consumption and emits very bright white light. (Cold Cathode Fluorescence Lamp) is used.

The light guide plate 110 is formed on the lower side of the LCD panel 100 and on one side of the light source 105, and converts spot light generated from the light source 105 into plane light to convert the light to the front surface. It serves to project.

A reflector plate 115 is formed on the rear surface of the light guide plate 110 and reflects light from the light source 105 toward the front LCD panel 100.

The diffuser sheet 120 is formed on the upper surface of the light guide plate 110 and serves to uniformize the light emitted through the light guide plate 110.

The prism sheet 125 is used to increase brightness by refracting and condensing light that diffuses in both horizontal and vertical directions while passing through the diffusion sheet 120, thereby rapidly decreasing brightness.

The protector sheet 130 is located on the top of the prism sheet 125 to prevent scratches of the prism sheet 125, and the moire phenomenon generated when using the prism sheet 125 formed in two layers in the vertical and horizontal directions. Used to prevent effects.

And, although not shown in Figure 1, the conventional backlight unit 10 is a frame (mold frame, which serves as a case for fixing each component constituting the backlight unit 10 to form a backlight unit 10 as an integral part, It further includes a cover (back cover, lamp cover) to protect the housing and the backlight unit 10 and to serve as strength maintenance and support.

2A and 2B are enlarged cross-sectional views of a light guide plate for explaining a process of light generated in the light source 105 in the light guide plate 110.

As shown in Fig. 2A, the light source 105 is usually located at the edge of the backlight unit 10 (in the case of LCD TV, it may be located directly behind the panel). As a result, the light is not uniformly transmitted over the entire surface and the edge tends to be brighter. To prevent this, the light guide plate 110 is used. The material of the light guide plate is usually a transparent acrylic resin, which is characterized by high strength and low cracking or deformation, and is light and has high visible light transmittance.

That is, the light guide plate 110 serves to cause the light source 105 to be uniformly projected on the front surface of the light guide plate 110. In fact, the light guide plate 110 may be disassembled by placing the light source on the side of the light guide plate to generate light. It can be seen that the surface of 110 is not uniformly bright but light is concentrated at both ends, because the light guide plate 110 guides the light of the light source 105 to the opposite side.

Therefore, as shown in FIG. 2B, in order to cause diffuse reflection on the rear surface of the light guide plate 110 so that the entire light guide plate 110 emits light uniformly, in particular, the distance from the light source 105 is considered. Prominence and depression (113) surface having a predetermined shape is designed. As a result of the pattern processing by forming the irregularities (113), flat light having a relatively high luminance and uniformity in the entire panel of the liquid crystal display device is formed. Is obtained.

However, when the LCD is manufactured using only the above method, the portion where the unevenness 113 is actually formed in the panel looks bright, and the part where the unevenness 113 is not formed appears dark, so the spot on the panel is spotted. The visible phenomenon occurs and the visibility is reduced. In particular, as the size of the panel has recently increased in size, an absolute amount of light reaching the light source 105 may be insufficient and thus may appear dark.

In addition, the diffusion sheet 120 and the prism sheet 125 is used to increase the uniformity of light, such a diffusion sheet or prism sheet has a problem of increasing the manufacturing cost of the backlight unit.

Accordingly, more research is required to obtain planar light having excellent visibility and high brightness and uniformity on the entire panel of the liquid crystal display without using a separate diffusion sheet 120 or prism sheet 125.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a light guide plate for a liquid crystal display backlight unit having high brightness and excellent light uniformity and visibility on the entire panel of a liquid crystal display device.

Another object of the present invention is to provide a backlight unit of a liquid crystal display device using the light guide plate according to the present invention.

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.

The light guide plate for a liquid crystal display device backlight unit according to an embodiment of the present invention for solving the above technical problem is a body including a front (front) and a back (side) to emit light is connected to the side, the side from which light is incident The prism having a predetermined cross-sectional shape is formed on the surface, and the front prism having a predetermined cross-sectional shape and the front prism having a predetermined cross-sectional shape on the rear surface, and a prism having a predetermined cross-sectional shape is formed on the surface, It includes dot prisms having a pattern that increases in size as it moves away.

According to another aspect of the present invention, there is provided a backlight unit for a liquid crystal display device including a light source and a light guide plate according to embodiments of the present invention.

Specific details of other embodiments are included in the detailed description and the accompanying drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the present embodiments to make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

In addition, the size of the components constituting the invention in the drawings are exaggerated for clarity of the specification, when any component is described as "exists inside, or is installed in connection with" other components, any of the above configuration An element may be installed in contact with the other component, or may be installed at a predetermined distance from the other component, and when installed at a distance, a third element for fixing or connecting the component to the other component The description of the means of may be omitted.

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

As shown in FIG. 3, the LGP 30 for the LCD unit backlight unit according to the exemplary embodiment of the present invention is generally made of a transparent acrylic material having high strength, less cracking or deformation, and light weight and high visible light transmittance. And a body part 300, front prisms 310, and dot prisms 320.

The body part 300 includes a side surface 301 through which light is incident, a front surface 303 connected to the side surface 301, and facing a panel (not shown) of the liquid crystal display, and the side surface 301. And a back surface 305 connected to and facing the front surface 303.

The original dictionary meaning of the side 301 refers to the side of the object, but in the present invention is defined as the side from which light is incident from the light source 306. Accordingly, in FIG. 3, the side surface 301 corresponds to two surfaces 301 adjacent to the light source 306.

The front surface 303 and the rear surface 305 are the surfaces from which the light incident from the light source 306 is incident on the side surface 301 is emitted, and is connected to the side surface 301 and respectively present inside the body portion 300. And the other surface corresponding to the outer surface of the body part.

The front surface 303 has a predetermined cross-sectional shape, and front prisms 310 are formed to uniformly diffract, refract, and diffuse the light emitted through the body 300.

The front prisms 310 are formed over the entire surface of the front surface 303 with a predetermined distance d, and the front prisms 310 are perpendicular to the P direction (the direction in which light is emitted from the light source) in FIG. 3. ) Is formed such that the longitudinal direction thereof is the longitudinal direction of each of the front prisms 310.

The reason why the front prisms 310 are formed at a predetermined distance d without densely arranging them is to improve and improve light uniformity and visibility.

That is, the light emitted from the body 300 is diffracted, refracted, and diffused in a direction inclined to the panel (not shown) of the liquid crystal display device facing the light guide plate 30 by the front prisms 310. By providing a spaced distance d between the front prisms 310, a panel of the liquid crystal display device emits light through the plane generated by the spaced distance d (meaning the space between the prisms in the front surface). This is to increase the uniformity of the light reaching the panel (not shown) of the liquid crystal display device by proceeding perpendicular to (not shown).

The reason why the lengthwise direction of each of the front prisms 310 is the P direction is to be perpendicular to each other with the prism to be formed on the rear surface 305, as described later.

In FIG. 3, the vertical cross-sections of the front prisms 310 have a triangular shape, but the present invention is not limited thereto and may be modified in various forms.

4A to 4B are perspective views illustrating various embodiments of cross-sectional shapes of the front prisms 310.

As shown in FIG. 4A, the front prisms 310 may have a trapezoidal shape in the longitudinal section thereof, and as shown in FIG. 4B, the front prism 310 may have a reverse point having a pointed tip and a predetermined radius of curvature. groove) type.

In this case, when the vertical cross-sectional shapes of the front prisms 310 are trapezoidal as shown in FIG. 4A, light passes through a plane A formed on each of the trapezoidal front prisms 310. It may be able to proceed perpendicular to (not shown).

In addition, when the vertical cross-sectional shape of the front prism 310 has a sharp end and the side surface has a predetermined radius of curvature, as shown in FIG. 4B, the radius of curvature of the side surfaces thereof is 0.01 to 1.0 mm. It is preferable.

The front prisms 310 may be formed on one surface or the other surface adjacent to the panel (not shown) of the liquid crystal display on the front surface 303.

The area ratio of the area occupied by the front prisms 310 and the spaced space between the front prisms 310 in the front surface 303 of the body part 300 is in the range of 1: 1 to 0.1: 1. The reason for this is that when the area ratio of the spaced space to the prism area is 1 or more, the diffraction and diffusion effects are reduced, resulting in a decrease in luminance.

3 and 4a to 4b, the ratio of the height h ₂ : pitch w _{2 of} each of the front prisms 310 may be in a range of 0.3 to 0.5, because the prism This is because when the ratio of the pitch to the height is 0.3 or less, the horizontal viewing angle becomes larger than necessary to decrease the luminance, and when 0.5 or more, the horizontal viewing angle becomes too small to satisfy the optical characteristics.

Referring to FIG. 3 again, the back surface 305 of the body portion 300 is formed with a dot (dot) arranged vertically and horizontally to have a predetermined distance from each other, this is defined as a dot prism 320.

FIG. 5 is an enlarged cross-sectional view of each dot prism 320 in FIG. 3.

As shown in FIG. 5, the dot prisms 320 have a prism 322 having a predetermined cross-sectional shape (shown in FIG. 5 as a prism having a triangular cross section) on its surface.

At this time, the longitudinal direction of the prism 322 formed on the surface of the dot prism 320 is preferably to be perpendicular to the direction of light coming from the light source (Q direction), because the direction of light coming from the light source 306 This is because the prism 322 must be formed to be perpendicular to the (Q direction) so that light diffraction, refraction and diffusion can occur properly.

In addition, as described above, the prism 322 formed on the dot prism 320 is preferably disposed perpendicular to the longitudinal direction (P direction) of the front prisms 310, because the prism 322 may emit light. This is because arranging them perpendicular to each other because of diffraction, refracting, and diffusing is advantageous for refracting and diffusing light uniformly throughout.

When the vertical cross-section of the prism 322 is formed on the surface of the dot prisms 320 as shown in Figure 5 into a triangle, it is preferable to form so that the cabinet (θ ₁₎ is 75 ~ 90 °.

Why should the cabinet (θ ₁₎ in the range as described above cabinet (θ ₁₎ is less than 75 ° or greater, the radiated light is the large, middle luminance is reduced vertical direction and the angle of the light unit front case than 90 ° Because.

In addition, the ratio of the height h ₁ : pitch w _{1 of} each of the prisms 322 formed on the surfaces of the dot prisms 320 is preferably in a ratio of 0.5 to 0.7, because the prism 322 is used. This is because when the ratio of the height to the pitch is 0.5 or less or 0.7 or more, the angle formed by the emitted light with the vertical direction of the front surface of the backlight unit is increased to decrease the central luminance.

6A through 6D illustrate embodiments of the shape of each of the dot prisms 320.

As shown in FIGS. 6A to 6D, the prisms 322 are formed inside the dot prisms 320, and the vertical cross-sectional shapes of the prisms 322 are circular (FIG. 6A) and oval (FIG. 6B). ), A rhombus (FIG. 6C) and a rectangle (FIG. 6D) or a combination of these forms.

As such, the shape of the dot prism 320 may be modified in various forms, but in the present invention, the dot prism 320 having an elliptical shape as shown in FIG. 6B is presented as the most preferred embodiment.

As shown in FIG. 6B, when the shapes of the dot prisms 320 are elliptical, the ratio of the short radius b and the long radius a is preferably 0.5 to 0.9.

When the shape of the dot prisms 320 is elliptical, the ratio of the short radius (b) to the long radius (a) should be such that when the ratio is less than 0.5, optical characteristics such as refractive and diffraction are not good. If it is exceeded, visibility problems occur, which is not preferable.

The dot prisms 320 may be formed on one surface or the other surface of the back surface 305 of the body portion 300 (when the surface inside the body portion is one surface, the surface outside the body portion is defined as the other surface).

7A to 7C are plan views viewed from the bottom of the body portion 300 of FIG. 3 to show the arrangement of the dot prisms 322.

FIG. 7A illustrates an elliptical shape of each of the dot prisms 320 as shown in FIG. 6B, and when the light generated from the light source (see 305 of FIG. 3) is incident from both sides of the body part 300 of the light guide plate, It is a top view which shows the arrangement form of 320).

As shown in FIG. 7A, when light is incident from both side surfaces 301 of the light source, the pattern of the size of the dot prisms 320 (the area occupied by each of the dot prisms on the back) increases from both sides 301 to the center. Has

The reason that the size of the dot prisms 320 increases as the distance from the light incident side 301 increases, so that the amount of light decreases as the distance from the light incident side 301 increases. Instead of increasing the amount of light by increasing the size of the dot prism 320 to serve to increase the amount of refraction and reflection of the light.

FIG. 7B is an elliptical shape of each of the dot prisms 320 as shown in FIG. 6B, and dot frees when light generated from a light source (see 306 of FIG. 3) is incident on only one side of the body part 300 of the light guide plate. It is a top view which shows the arrangement form of 320. FIG.

As shown in FIG. 7B, when the light is incident only on one side 301, the size of the dot prisms 320 increases as it passes through the center and toward the other side.

7C is a plan view showing another embodiment of a dot prism according to an embodiment of the present invention.

As shown in FIG. 7C, the rear surface 305 of the body portion (see 300 of FIG. 3) of the light guide plate has a space or a space between the dot prisms 320 in addition to the dot prisms 320 formed in FIGS. 7A to 7B. Second dot prisms 325 in which a prism having a direction not parallel to the longitudinal direction of the prism (see 322 of FIG. 5) formed on the surface of the dot prisms 320 in the space may be further included. .

The reason for forming the second dot prisms 325 as described above is to increase the refraction and reflectance of the light.

However, the shape of the dot prisms 320 shown in Figure 7a to 7c is oval, but not limited to this, the application of the dot prism having a circle, a rhombus, a rectangle shown in Figures 6a to 6d In this case, it will also have a pattern that increases in size as the distance away from the light incident side (301).

In addition, although the shapes of the second dot prisms 325 are shown as circular in FIG. 7C, the shapes of the second dot prisms 325 may be formed in other shapes such as triangles, squares, pentagons, hexagons, ellipses, and rhombuses.

7A to 7C, the dot prisms 320 are vertically and horizontally disposed on the rear surface 305 of the body portion (see 300 in FIG. 3) of the light guide plate. The rows are arranged in the form of zig zags that do not overlap each other.

The reason for arranging the dot prisms 320 in the zigzag form as described above is to maximize the function of the dot prism in consideration of the traveling direction of the light to further increase the uniformity of the emitted light and to improve visibility.

Hereinafter, using the light guide plate according to the embodiment of the present invention will be described with specific experimental examples that have a superior property when measuring the brightness (brightness), uniformity (uniformity) and visibility of the light. Details not described herein are omitted because they can be sufficiently inferred by those skilled in the art.

Referring to the experimental examples carried out to prove the effect of the configuration of the present invention.

< Experimental Example  1>

There is no change in the size of the dot prism, and the front prisms having a triangular cross section are formed on the entire upper surface of the light guide plate without a distance. Width (W) x length (L) x thickness (T); Elliptical dot prisms with a long radius of 0.3 mm and a short radius of 0.2 mm are formed at the bottom of the light guide plate manufactured to be 332.5 × 441.5 × 10.0mm to have a light source horizontal spacing of 0.62mm and a light source vertical spacing of 1.08mm. A prism having a pitch of 50 µm and an internal angle of 82.5 degrees was formed. In addition, a front prism having a height of 13 μm and a pitch of 32 μm was disposed on the entire upper surface of the light guide plate without a plane separation distance.

< Experimental Example  2>

The size of the dot prism was changed as in the present invention, but front prisms having a triangular cross section were formed on the entire upper surface of the light guide plate. Width (W) x length (L) x thickness (T); On the lower part of the light guide plate manufactured to be 332.5 × 441.5 × 10.0mm, oval dot prisms having a long radius of 0.3 mm and a short radius of 0.2 mm are formed to have a light source horizontal distance of 0.62 mm and a vertical light source distance of 1.08 mm, with the dot on the surface in contact with the light source. The long radius of the dot was 0.3 mm and the longest radius of the dot was 0.5 mm at the center of the light guide plate farthest from the light source. A prism having a height of 30 µm, a pitch of 50 µm, and an internal angle of 82.5 degrees was formed inside the dot. In addition, a front prism having a height of 13 μm and a pitch of 32 μm was disposed on the entire upper surface of the light guide plate without a plane separation distance.

< Experimental Example  3>

There is no change in the size of the dot prism, and the front prisms having a triangular cross section are formed on the upper surface of the light guide plate with a predetermined plane separation distance. Width (W) x length (L) x thickness (T); Elliptical dot prisms with a long radius of 0.3 mm and a short radius of 0.2 mm are formed at the bottom of the light guide plate manufactured to be 332.5 × 441.5 × 10.0mm to have a light source horizontal spacing of 0.62mm and a light source vertical spacing of 1.08mm. A prism having a pitch of 50 µm and an internal angle of 82.5 degrees was formed. In addition, front prisms having a height of 13 μm and a pitch of 64 μm (a plane separation distance of 32 μm) of the light guide plate were disposed.

< Experimental Example  4>

The size of the dot prism was changed as in the present invention, but front prisms having a triangular cross section were formed on the upper surface of the light guide plate with a predetermined plane separation distance. Width (W) x length (L) x thickness (T); On the lower part of the light guide plate manufactured to be 332.5 × 441.5 × 10.0mm, oval dot prisms having a long radius of 0.3 mm and a short radius of 0.2 mm are formed to have a light source horizontal distance of 0.62 mm and a vertical light source distance of 1.08 mm, with the dot on the surface in contact with the light source. The long radius of the dot was 0.3 mm and the longest radius of the dot was 0.5 mm at the center of the light guide plate farthest from the light source. A prism having a height of 30 µm, a pitch of 50 µm, and an internal angle of 82.5 degrees was formed inside the dot. In addition, a front prism having a height of 13 μm, a pitch of 64 μm (a plane separation distance of 32 μm), and a triangular cross section was disposed on the upper surface of the light guide plate.

< Experimental Example  5>

The size of the dot prism is changed as in the present invention, but the reverse groove type front prisms having a predetermined distance from the upper surface of the light guide plate and having a predetermined radius of curvature on the side of the light guide plate are formed. Length L x thickness T; On the lower part of the light guide plate manufactured to be 332.5 × 441.5 × 10.0mm, oval dot prisms having a long radius of 0.3 mm and a short radius of 0.2 mm are formed to have a light source horizontal distance of 0.62 mm and a vertical light source distance of 1.08 mm, with the dot on the surface in contact with the light source. The long radius of the dot was 0.3 mm and the longest radius of the dot was 0.5 mm at the center of the light guide plate farthest from the light source. A prism having a height of 30 µm, a pitch of 50 µm, and an internal angle of 82.5 degrees was formed inside the dot. In addition, reverse groove type front prisms having a height of 13 μm, a pitch of 64 μm (a plane separation distance of 32 μm), a sharp end, and a predetermined radius of curvature were disposed on the upper surface of the light guide plate.

The above sample was measured in the unit of cd / m ² through the luminance meter, and determined 25 points on the light exit surface of the backlight unit to measure the luminance value from them, and from this uniformity of luminance (lowest / maximum) Value x 100) was measured.

In addition, the visibility was observed through the eye of the measuring object and focused on whether there was a particularly bright or dark surface.

The results of measuring the brightness, uniformity and visibility according to the above experimental conditions are shown in Table 1. In Experimental Examples 1 to 4, the brightness and uniformity were good, but in the case of Experimental Example 1, some fine dots were observed. It was a bad side, and in the case of Experimental Example 2 to Experimental Example 4, a few fine dots were observed and relatively excellent in visibility.

On the other hand, in Experimental Example 5, the uniformity of the brightness and uniformity, as well as the uniformly visible light (plane light) with excellent visibility as a whole without the visible part of the dot shape was obtained.

Table 1 below shows the results of measuring the brightness, uniformity and visibility of the light while changing the shape and pattern of the dot prism and the prism of the light guide plate.

In the case of using the above-described light guide plate (see 30 in FIG. 3), a diffusion sheet and a prism sheet, which are generally used in a backlight unit for a conventional liquid crystal display, are not the same as those used therein. The effect can be obtained. That is, in the case of using the light guide plate according to the embodiments of the present invention, only the light source and the light guide plate may obtain surface light having excellent brightness, uniformity, and visibility.

 Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments but may be manufactured in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

The light guide plate for the liquid crystal display device backlight unit and the backlight unit for the liquid crystal display device using the same according to the embodiments of the present invention uniformly refracts and diffuses the light generated from the light source in the direction inclined to the panel of the liquid crystal display device and at the same time Since the light is advanced perpendicular to the panel of the display device, the entire liquid crystal display device can be illuminated with excellent brightness, uniformity, and visibility. Therefore, the backlight unit can be configured by omitting all or one of the diffusion sheet and the prism sheet used in the existing backlight unit.

Claims (18)

A body portion including a front side and a rear side of the side to which light is incident and connected to the side to emit the light; Front prisms disposed on the front surface and having a predetermined cross-sectional shape; And Prisms having a predetermined cross-sectional shape are formed on the rear surface at regular intervals to have a predetermined distance from each other, and include dot prisms having a pattern whose size increases as the distance from the side to which light is incident is increased. A light guide plate for a liquid crystal display backlight unit. The method of claim 1, And the dot prisms have a pattern in which the size of the dot prism is increased from the side to the center when light is incident from both sides of the light guide plate. The method of claim 1, And the dot prisms have a pattern in which a size increases from one side to the other when light is incident only from one side of the light guide plate. The method according to any one of claims 1 to 3, The dot prisms are disposed on the rear surface of the light guide plate vertically and horizontally, and the light guide plate for the liquid crystal display device of the backlight unit, characterized in that arranged in a zigzag form in which odd rows and even columns do not overlap each other. The method of claim 1, The front prism is one of the light guide plate of the liquid crystal display device backlight unit, characterized in that the vertical cross-section is a triangular, trapezoidal shape, the side surface is pointed end and the side surface has a predetermined radius of curvature. The method of claim 1, And a front prism formed on the surface of the dot prisms so as to be perpendicular to each other. The method of claim 1, A light guide plate for a liquid crystal display device backlight unit, characterized in that the longitudinal direction of the prism formed on the surface of the dot prism is horizontal to the longitudinal direction of the light source. The method of claim 1, And the front prisms are disposed at a predetermined distance from each other so that a plane may exist between the front prisms. The method of claim 1, A second dot prism having a predetermined shape and spaced apart from the longitudinal direction of the prism formed on the dot prism surface is further formed in the spaced space between the dot prisms on the rear surface. LGP for liquid crystal display backlight unit. The method of claim 1, The dot shape of the dot prism is one of a circle, an ellipse, a rhombus, a rectangle, or a combination of these forms, the light guide plate for a liquid crystal display device backlight unit. The method of claim 1, The prism formed on the surface of the dot prism has a triangular cross-sectional shape, the inner angle of the light guide plate for the liquid crystal display device unit, characterized in that 75 ~ 90 °. The method according to claim 1 or 10, The light guide plate for the liquid crystal display device backlight unit, characterized in that when the shape of the dot prism is elliptical, the ratio between the short radius and the long radius is 0.5 to 0.9. The method according to claim 1 or 5, And wherein the longitudinal cross-section of the front prisms is an inverted groove having a sharp end and a predetermined radius of curvature, wherein the radius of curvature is 0.01 to 1.0 mm. The method of claim 1, The area ratio of the area occupied by the front prism on the front surface of the light guide plate to the spaced space between the front prism is in a range of 1: 1 to 0.1: 1. The method of claim 1, A light guide plate for a liquid crystal display device backlight unit, characterized in that the "height: pitch" ratio of the prism in the dot prism on the rear surface is 0.5 to 0.7. The method of claim 1, A light guide plate for a liquid crystal display backlight unit, wherein a height: pitch ratio of each of the front front prisms is 0.3 to 0.5. The method of claim 9, The shape of the second dot prism is one of a circle, an ellipse, a rhombus, a rectangle, or a combination of these shapes. Light source; And A backlight unit for a liquid crystal display device comprising the light guide plate of claim 1.

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