KR20080067894A - Light guide panel comprising step structure for back light unit of tft-lcd - Google Patents

Abstract

A light guide panel comprising a step structure for a back light unit of a TFT-LCD is provided to obtain the same brightness by having high brightness and excellent uniformity although at least one sheet of a prism sheet or a diffusion sheet is omitted. A light guide panel having a step structure for a back light unit of a TFT-LCD includes a light incident surface(210), a front surface(230), and a rear surface(220). A light from a light source is inputted to the light incident surface. The front surface emits the light. The rear surface has a cross-section structure mixed with a geometric reflective body and a plurality of step shapes for reflecting the light to the front surface. The plurality of step shapes are parallel to the front surface. The plurality of step shapes are constructed such that a distance from the front surface becomes shorter as the light becomes farther from the side surface.

Description

LIGHT GUIDE PANEL COMPRISING STEP STRUCTURE FOR BACK LIGHT UNIT OF TFT-LCD}

1 is a perspective view illustrating a light guide plate for a liquid crystal display backlight unit according to a first embodiment of the present invention.

2A and 2B are rear perspective views illustrating a pattern formed on the rear surface of FIG. 1 according to the first embodiment of the present invention.

3A and 3B are plan views illustrating a light guide plate for a liquid crystal display backlight unit according to a second embodiment of the present invention.

4 is a plan view illustrating a light guide plate for a liquid crystal display backlight unit according to a third exemplary embodiment of the present invention.

5 is a plan view illustrating a light guide plate for a liquid crystal display backlight unit according to a fourth exemplary embodiment of the present invention.

6A is a cross-sectional view taken along the plane A-B of FIG. 2A.

6B is a cross-sectional view taken along the plane C-D of FIG. 2A.

7A is a cross-sectional view taken along the plane A-B of FIG. 3A.

7B is a cross-sectional view taken along the plane C-D of FIG. 3A.

8A is a cross-sectional view taken along the plane A-B of FIG. 4.

8B is a cross-sectional view taken along the plane C-D of FIG. 4.

9A is a cross-sectional view taken along the plane A-B of FIG. 5.

9B is a cross-sectional view taken along the plane C-D of FIG. 5.

FIG. 10 is a diagram for illustrating the basic inclination of the back surface of the light guide plate having the above-described back surface having a stepped pattern.

The present invention relates to a light guide plate for a liquid crystal display device backlight unit, and more particularly to a light guide plate for a liquid crystal display device backlight unit that can increase the brightness and uniformity by forming a predetermined pattern on the back of the wedge-shaped light guide plate mainly used in notebooks. It is about.

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 and switched by an electric field to display numbers or images.

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 lighted in a panel unit in which liquid crystals are constantly arranged. Images are displayed while adjusting the amount of transmission.

The backlight unit 10 of the liquid crystal display device has a direct type in which a light source is located directly below the panel of the liquid crystal display device and an edge type in which the light source is located at the side surface of the liquid crystal display panel according to the position of the light source that emits light. The light guide plate may be divided into a flat plate having light sources on both sides and a wedge type having a light source on only one side according to its shape.

Conventional edge-wedge light guide plate has a side to which light is incident, a front to which light is emitted, and a back to reflect light and exit to the front, and in particular, the light source is provided adjacent to one side.

In addition, two prism sheets, a diffusion sheet, and a protective sheet may be stacked on the front surface where light is emitted from the edge-wedge light guide plate, and a printed pattern such as a dot prism may be formed on the rear surface.

At this time, the diffuser sheet (diffuser sheet) is formed on the upper surface of the light guide plate and serves to uniform the light emitted through the light guide plate.

The prism sheet is used to increase brightness by refracting and condensing light that diffuses in both horizontal and vertical directions as it passes through the diffusion sheet, thereby rapidly decreasing brightness. Generally, two prism sheets are used. .

A protector sheet is used to prevent scratches of the prism sheet and to prevent moire effects occurring when using a prism sheet formed in two layers in the vertical and horizontal directions.

As described above, the edge-wedge light guide plate is intended to provide a surface light source having a uniform and high luminance over the entire surface while moving light entering the light guide plate to the opposite side only from one side.

As described above, the edge-wedge light guide plate has lower luminance than the edge-plate light guide plate having light sources on both sides, but is mainly used when the light source exists only on one side due to the narrow space of the bezel, such as a notebook PC. .

Therefore, a lot of researches on the design of the light guide plate in order to maximize the light efficiency with a small amount of light in the case of the edge-wedge light guide plate.

The technical problem to be achieved by the present invention is a light guide plate for a liquid crystal display device backlight unit that can achieve the same brightness even if at least one of the prism sheet or the diffusion sheet is omitted because of high luminance and excellent light uniformity and visibility in the entire panel. In providing.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, 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 the first embodiment of the present invention for solving the above technical problem is a side surface on which light is incident from a light source, a front surface from which light is emitted, and a geometric reflector for reflecting light to the front surface; It includes a back surface having a mixed cross-sectional structure of the step shape, each step is characterized in that the parallel to the front surface, the distance from the front surface closer to the light incident side.

The light guide plate for a liquid crystal display device backlight unit according to the second embodiment of the present invention for solving the above technical problem is a side of the light incident from the light source, a front surface from which the light is emitted, a geometric reflector for reflecting the light to the front surface; The stepped shape includes a rear surface having a mixed cross-sectional structure, wherein the stepped shape is characterized in that the distance from the front side closer to the light incident side.

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, and when any component is described as "existing inside or connected to the other components", A component may be installed in contact with the other component, or may be installed at a predetermined separation distance, and when installed at a separation distance, a component for fixing or connecting the component to the other component. The description of the means of 3 may be omitted.

1 is a perspective view illustrating a light guide plate for a liquid crystal display backlight unit according to a first embodiment of the present invention.

As shown in FIG. 1, the light guide plate 20 for the liquid crystal display backlight unit according to the first exemplary embodiment of the present invention is incident on only one side (referred to as the light incident surface 210) where light is adjacent to the light source 140. It is not incident on the other side (this is called the incident light surface 215).

The front surface 230 is connected to the light incident surface 210 so as to be perpendicular to the light incident surface 210, and the light entering the light guide plate through the light incident surface 210 is emitted and is the surface closest to the liquid crystal display panel.

The light guide plate feature according to the first embodiment of the present invention is present in the pattern formed on the rear surface 220 of the wedge-shaped light guide plate.

2A and 2B are rear perspective views illustrating a pattern formed on the rear surface of FIG. 1 according to the first embodiment of the present invention.

2A and 2B, the rear surface 220 of the light guide plate according to the first embodiment of the present invention has a distance from the front surface 230 toward the light incident surface 215 toward the light incident surface 215. see Figure 2b for reference d ₁ ~ ₆ d) a plurality of planes (1, 2, 3, 4, 5, 6 to approach) is characterized in that it is arranged in a step-like.

2A and 2B show the case where the number of the plurality of planes is six, in practice, the number of the plurality of planes 1 to 6 depends on the size of the light guide plate and the distance between the plane and the plane, that is, the pitch P. Will be decided accordingly.

In this case, the plurality of planes 1 to 6 may be manufactured to be parallel to the front surface 230.

If the rear surface 220 is inclined with respect to the horizontal plane, the theoretical total reflection light guide is not made, and an elevation emission component is generated, and the generation of the elevation emission component leads to loss of light.

At this time, the planar sections 1 to 6 are opposed to the front surface 230 within an error range of ± 0.5 °, which is to consider the errors in the manufacturing process.

The basic overall tilt of the back surface 220 relative to the front surface 230 is determined by the length of the light incident surface 210, the incoming light surface 215 and the light guide plate.

When the length L _x of each step shape is constant, it is preferable that the ratio of the length L _{x of} each step: the length L ₀ of the entire light guide plate is in the range of 1: 100 to 1: 1,000. .

The main deciding factor is the number of light sources, and as the number of light sources increases, the ratio between the light incident surface and the incident light surface increases, thus increasing the basic slope of the back surface. In this example, it was produced to be 0.42 °.

Referring to FIG. 2B, steps 211 and geometric reflectors 212 and 213 may be formed on the surfaces connecting the planes adjacent to each other in the plurality of planes 1 to 6 (for example, one plane and two planes in FIG. 2B). Where the geometric reflectors 212 and 213 are composed of a combination of an intaglio prism 212 inner angle θ ₂ and an embossed prism 213 inner angle θ ₃ .

Here, the left side of the intaglio prism 212 (based on FIG. 2B) is shared with the right side of the staircase, and the right side of the intaglio prism 212 is shared with the left side of the embossed prism 213.

At this time, the interior angle θ ₁ of the step shape 211 preferably has a range of 110 to 160 °, and the interior angle θ ₂ of the intaglio prism 212 and the interior angle θ ₃ of the embossed prism 213 are 60. It is preferable to have a range of ˜100 °.

The inner angle θ ₁ of the staircase shape 211 should be in the range of 110 to 160 °. The main function of reflecting light and raising it in the vertical direction is based on the right side of the embossed prism 213 (FIG. 2B). This is because the right side of the staircase shape 211 (based on FIG. 2) serves to first reflect light vertically and to allow light to travel through the embossed prism 213.

In the process of performing these two roles, when the inside angle θ ₁ of the stepped shape 211 becomes 110 to 160 °, the inclination of the right side of the stepped shape 211 and the right side of the embossed prism 213 is almost This is because the embossing prism 213 can effectively raise the light vertically toward the front surface.

The reason why the inner angle θ ₃ of the embossed prism 213 should be in the range of 60 to 100 ° is to raise the incident light as vertically as possible in the front direction as in the case of the step shape 211. The light incident at about 82.5 ° is best reflected and refracted vertically.

In addition, the end of the embossed prism 213 is preferably farther from the front surface 230 than the end of the stepped shape 211, because the light passing through the right side of the stepped shape 211 embossed prism 213 It is refracted to the left side of) and reflected in the right side of the embossed prism 213 to proceed in the vertical direction, in which the light passing through the right side of the staircase 211 does not escape in the front direction, the embossed prism It is advantageous for the tip of the embossed prism 213 to be farther away from the front than the step of the stepped shape in order to allow a lot of incidence to the left side of 213.

Light incident surface: The width of the light incident surface is preferably in the range of 9: 1 to 1: 1.

In addition, the ratio of the height of the intaglio prism 212 and the embossed prism 213 preferably has a range of a ratio of 1: 2 to 2: 1.

In addition, the ratio of the area occupied by the geometric reflector and the step shape on the rear surface of the light guide plate is preferably in the range of 1: 100 to 1: 10,000.

In the back surface 220 of the light guide plate in which the plurality of planes 1 to 6 are formed in a step shape as described above, the distance between the planes adjacent to each other among the plurality of planes, or the embossed prism 213 adjacent to each other. The distance, i.e., pitch (P) of FIG. 2 varies depending on the intensity of light emitted from the area light source of the light guide plate and the type of light source, but is preferably 0.3 to 2 mm.

Referring again to FIG. 2B, dot prisms 222 formed of a predetermined shape, such as a circle, an ellipse, a rhombus, a rectangle, or a combination thereof may be further formed on the surfaces of the plurality of planes 1 to 6. This is to more effectively reflect the debt incident on the light incident surface 210 to the front surface 230.

However, the longitudinal direction of the prism formed on the surface of the dot prism 222 is preferably disposed to be perpendicular to the direction in which light is incident.

Referring to FIG. 2A, a light incident surface at a light incident surface 210 in which light is incident on the surface of the plurality of planes 1 to 6 instead of or in parallel with the dot prism 222 or optionally A stripe pattern 230 may be formed in which the width increases toward the direction 215 and a plurality of prisms are formed on a surface thereof, and a length direction of the plurality of prisms is perpendicular to a direction in which light is incident. .

At this time, it is preferable that the inner angle of the prism inside the stripe pattern 230 is 70 to 85 °, and the ratio of the vertically emitted light increases within this range, thereby enabling the implementation of a high brightness liquid crystal display device.

Referring to FIG. 2B, the front surface 230 may have a predetermined cross-sectional shape, and front prisms 315 may be formed to uniformly refract and diffuse light emitted through the light guide plate.

The front prisms 315 are formed over the entire front surface 230, and the longitudinal direction of the front prisms 315 is parallel to the direction in which light is incident.

However, in FIG. 2B, the front prisms 315 have a triangular cross-sectional shape, but not limited thereto. For example, the front prisms 315 may have various shapes, such as a trapezoidal shape and a reverse groove having a predetermined radius of curvature. It can also be changed to one of the types.

As shown in FIG. 2B, the front prisms 315 may be disposed at a predetermined distance d from each other, for the purpose of improving light uniformity and visibility.

That is, the light emitted from the light guide plate is refracted and diffused in a direction inclined by the front prism 315 to a panel (not shown) of the liquid crystal display facing the light guide plate, and the light is separated between the front prisms 315. By setting the separation distance d, the light travels perpendicularly to the panel (not shown) of the liquid crystal display device through the plane generated by the separation distance d (meaning the space between the front prisms). This is to increase the uniformity of light reaching the panel (not shown) of the liquid crystal display device.

The area ratio of the area occupied by the front prisms 315 and the spacing plane generated by the distance d between the front prisms 315 in the front surface 230 is in the range of 1: 0.5 to 1:10. It is desirable to have.

In addition, it is preferable that the ratio of height h2: width W2 of each of the front prisms 315 has a range of 0.3 to 0.6, because the ratio of the height to the height of the prism is less than 0.3 is horizontal. This is because the viewing angle becomes larger than necessary to reduce the luminance, and when 0.6 or more, the horizontal viewing angle becomes too small to satisfy the optical characteristics.

3A and 3B are plan views illustrating a light guide plate for a liquid crystal display backlight unit according to a second embodiment of the present invention.

3A and 3B, the same reference numerals as used in FIGS. 2A and 2B denote the same members.

Therefore, in analyzing FIGS. 3A and 3B, the same reference numerals as those in FIGS. 2A and 2B are interpreted with reference to FIGS. 2A and 2B.

In the following, the points distinguishing from FIGS. 2A and 2B in FIGS. 3A and 3B will be described, and the remaining parts are the same as those of FIGS. 2A and 2B.

Referring to FIGS. 3A and 3B, the geometric reflector, which is a plane connecting the stepped planes 1 to 6, is not composed of a plurality of prisms, unlike one of FIGS. 2A and 2B. It consists of 212 only.

At this time, the internal angle θ1 of the stepped shape 211 and the internal angle θ1 of the intaglio prism 212 are as described above.

4 is a plan view illustrating a light guide plate for a liquid crystal display backlight unit according to a third exemplary embodiment of the present invention.

In FIG. 4, the same reference numerals as used in FIG. 2A represent the same members, and a description thereof will be interpreted with reference to FIG. 2A.

However, in FIG. 4, a technical feature distinguished from FIG. 2A is that light is incident from two sides, that is, two light incident surfaces 210.

Therefore, in this case, the width of the stripe pattern will be wider from the side to the middle, and the distance between the plane and the front surface of the stairs will become shorter from the side to the middle.

5 is a plan view illustrating a light guide plate for a liquid crystal display backlight unit according to a fourth exemplary embodiment of the present invention.

In FIG. 5, the same reference numerals as used in FIG. 3A represent the same members, and a description thereof will be interpreted with reference to FIG. 3A.

In FIG. 5, a technical feature distinguished from FIG. 3A is that light is incident from two sides, that is, two light incident surfaces 210.

Therefore, in this case, the width of the stripe pattern will be wider from the side to the middle, and the distance between the plane and the front surface of the stairs will become shorter from the side to the middle.

In the following, cross-sectional views of important parts of the above-described drawings are provided to help understanding of the present invention.

However, the same reference numerals as those described above among the reference numbers described in the following cross-sectional views are interpreted with reference to FIGS. 2A, 3A, 4, and 5.

6A is a cross-sectional view taken along the plane A-B of FIG. 2A.

As shown in FIG. 6A, it can be seen that unit prisms 311 are formed on the surface of the stripe pattern 310.

6B is a cross-sectional view taken along the plane C-D of FIG. 2A.

As shown in FIG. 6B, the incision along the C-D plane of FIG. 2A shows that the plurality of planes 1 to 6, as described in the first embodiment of FIG. 2A, are arranged in a step shape.

7A is a cross sectional view taken along the A-B plane of FIG. 3A and FIG. 7B is a cross sectional view taken along the C-D plane of FIG. 3A.

8A is a cross-sectional view taken along the plane A-B of FIG. 4, and FIG. 8B is a cross-sectional view taken along the plane C-D of FIG. 4.

As shown in FIGS. 8A and 8B, the rear surface of FIG. 4 may be closer to the front surface as the light is incident from both sides.

9A is a cross-sectional view taken along the plane A-B of FIG. 5, and FIG. 9B is a cross-sectional view taken along the plane C-D of FIG. 5.

FIG. 10 is a diagram illustrating the basic inclination of the back surface of the light guide plate having the above-described back surface 220 having a stepped pattern.

As shown in FIG. 10, the rear surface 220 of the light guide plate of the present invention has a geometric reflector and a stepped pattern, but the basic slope θ4 is a difference between the light incident surface 210 and the light incident surface 215 of the light guide plate. Is determined by the total length of the light guide plate and has a value of 0 to 2 °.

Hereinafter, the light guide plate for the liquid crystal display device backlight unit according to the embodiments of the present invention will be described with reference to specific examples and comparative examples that the liquid crystal display device has excellent brightness, uniformity, and visibility. Details not described herein are omitted because they can be sufficiently inferred by those skilled in the art.

One. Examples  And Comparative Examples

< Example  1-1>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the basic slope of the back side with respect to the front is 0.42 ° due to the thickness difference between the light incident surface and the incident light surface and the length of the light guide plate. A pattern according to the present invention was formed, and a single step structure having an inner angle (θ ₁ ) of 130.33 ° was formed at intervals of 1000 μm, and each step was inclined at 0.42 ° so as to have a parallel structure with the front surface. In this case, the height difference between each step prism is about 7.33 mu m. In addition, a stripe prism pattern having an angle of 81.5 ° was simultaneously formed.

< Example  1-2>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the basic slope of the back side with respect to the front is 0.42 ° due to the thickness difference between the light incident surface and the incident light surface and the length of the light guide plate. a pattern was formed in accordance with the present invention, the cabinet (θ ₁₎ is 130.33˚ the stairs and 81.5 ° in to form a double step structure of the reflector geometry to 1000㎛ interval, 0.42 each stairs to a parallel structure and the front ° tilted. In this case, the height difference between each step prism is about 7.33 mu m. In addition, a stripe prism pattern having an angle of 81.5 ° was simultaneously formed.

< Comparative example  1-1>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the basic slope of the back side with respect to the front is 0.42 ° due to the thickness difference between the light incident surface and the incident light surface and the length of the light guide plate. A pattern according to the present invention was formed, and a single step structure having an inner angle (θ ₁ ) of 130.33 ° was formed at intervals of 1000 μm, and each step was inclined at 0.42 ° so as to have a parallel structure with the front surface. In this case, the height difference between each step prism is about 7.33 mu m.

< Comparative example  1-2>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the basic slope of the back side with respect to the front is 0.42 ° due to the thickness difference between the light incident surface and the incident light surface and the length of the light guide plate. a pattern was formed in accordance with the present invention, the cabinet (θ ₁₎ is 130.33˚ the stairs and 81.5 ° in to form a double step structure of the reflector geometry to 1000㎛ interval, 0.42 each stairs to a parallel structure and the front ° tilted. In this case, the height difference between each step prism is about 7.33 mu m.

< Example  2-1>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the front prism was formed on the front surface of the light guide plate in parallel with the direction of light emitted from the lamp and having a distance of 50µm and a 90 ° vertex angle. In addition, the basic inclination of the back surface with respect to the front surface is 0.42 ° depending on the thickness difference between the light incident surface and the incoming light incident surface and the length of the light guide plate, wherein at the back, a cabinet having a pattern according to the present invention (θ ₁ ) 130.33˚ single step structure 1000 Formed with a thickness interval, but tilted 0.42 ° so that each step is parallel to the front structure. In this case, the height difference between each step prism is about 7.33 mu m. In addition, a stripe prism pattern having an angle of 81.5 ° was simultaneously formed.

< Example  2-2>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the front prism was formed on the front surface of the light guide plate in parallel with the direction of light emitted from the lamp and having a distance of 50µm and a 90 ° vertex angle. In addition, the basic slope of the back side with respect to the front surface is 0.42 ° depending on the thickness difference between the light incident surface and the incoming light surface and the length of the light guide plate. At this time, the back angle (θ ₁ ) 130.33 ° staircase structure and 81.5 ° The double staircase structure of the geometric reflector was formed at intervals of 1000 μm, and each step was inclined at 0.42 ° to be parallel to the front face. In this case, the height difference between each step prism is about 7.33 mu m. In addition, a stripe prism pattern having an angle of 81.5 ° was simultaneously formed.

< Comparative example  2-1>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the front prism was formed on the front surface of the light guide plate in parallel with the direction of light emitted from the lamp and having a distance of 50µm and a 90 ° vertex angle. In addition, the basic inclination of the back surface with respect to the front surface is 0.42 ° depending on the thickness difference between the light incident surface and the incoming light incident surface and the length of the light guide plate, wherein at the back, a cabinet having a pattern according to the present invention (θ ₁ ) 130.33˚ single step structure 1000 Formed with a thickness interval, but tilted 0.42 ° so that each step is parallel to the front structure. In this case, the height difference between each step prism is about 7.33 mu m.

< Comparative example  2-2>

Width (W) x length (L) x thickness (T); In the wedge-shaped light guide plate of 288.8 × 217.7 × 2.4 (light incident surface) × 0.8 (receiving surface) mm, the front prism was formed on the front surface of the light guide plate in parallel with the direction of light emitted from the lamp and having a distance of 50µm and a 90 ° vertex angle. In addition, the basic slope of the back side with respect to the front surface is 0.42 ° depending on the thickness difference between the light incident surface and the incoming light surface and the length of the light guide plate. At this time, the back angle (θ ₁ ) 130.33 ° staircase structure and 81.5 ° The double staircase structure of the geometric reflector was formed at intervals of 1000 μm, and each step was inclined at 0.42 ° to be parallel to the front face. In this case, the height difference between each step prism is about 7.33 mu m.

2. Analysis of the results

Table 1 shows the results of luminance measurements for Examples 1-1, 1-2, and 1-1, 1-2 in comparison, Table 2 shows specific values for the luminance of Table 1, and each of Examples. And it shows the appearance of the light guide plate manufactured by the comparative examples.

Referring to Table 1 and Table 2, it can be seen that the embodiments have a higher luminance value than the comparative example as a whole, and the appearance state is also good.

Table 3 shows the results of luminance measurements for Examples 2-1, 2-2, and 2-1 and 2-2, and Table 4 shows specific values for the luminance of Table 3, and the respective examples. And it shows the appearance of the light guide plate manufactured by the comparative examples.

Referring to Tables 3 and 4 above, it can be seen that the embodiments have better luminance values and appearance than the Comparative Examples.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings and tables, the present invention is not limited to the above embodiments, but may be manufactured in various forms, and common knowledge in the art to which the present invention pertains. Those skilled in the art can understand that the present invention can be implemented 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.

According to the light guide plate for the liquid crystal display device backlight unit according to the embodiment of the present invention, it is possible to manufacture the light guide plate for the liquid crystal display device backlight unit having high brightness and excellent light uniformity and visibility on the entire surface of the panel. At least one of the prism sheet or the diffusion sheet formed in the can be omitted, there is an advantage that the manufacturing cost and thickness of the product can be lowered.

Claims (23)

A light incident surface into which light is incident from a light source, a front surface from which light is emitted, and a rear surface having a cross-sectional structure in which a plurality of step shapes and a geometric reflector for reflecting light to the front surface are mixed. A light guide plate for a liquid crystal display device backlight unit having a cross-sectional structure, characterized in that the parallel to the distance from the light incident side is closer to the front surface. And a rear surface having a cross-sectional structure in which a side from which light is incident from a light source, a front surface from which light is emitted, and a geometric reflector for reflecting light to the front surface and a plurality of stepped shapes are mixed, wherein the plurality of stepped shapes are constant with the front surface. A light guide plate for a liquid crystal display device backlight unit having a cross-sectional structure which is inclined at an angle and configured to be closer to the front surface as the light is incident from the side. The method of claim 1 A light guide plate for a liquid crystal display backlight unit, wherein a plurality of staircase shapes are formed parallel to the front surface to reflect light to the front surface or to guide light under total reflection conditions. The method of claim 2 A light guide plate for a liquid crystal display backlight unit, characterized in that a plurality of staircase shapes are formed at an angle with the front surface so as to reflect or guide light to the front surface. The method according to claim 1 or 2, The light guide plate for a liquid crystal display device backlight unit, characterized in that at least one stripe prism is formed that increases in width as it moves away from one side of the light on the step surface of the back. The method according to claim 1 or 2, Light-emitting surface: A light guide plate for a liquid crystal display device backlight unit, characterized in that the width of the light-receiving surface is 9: 1 to 1: 1. The method according to claim 1 or 2, And the geometric reflector between the staircases is formed of a combination of an intaglio prism θ ₂ ) and an embossed prism (inner angle θ ₃ ). The method according to claim 1 or 2, A light guide plate for a liquid crystal display backlight unit, characterized in that the step-shaped interior is 110 ~ 160 °. The method according to claim 2 or 4, A light guide plate for a liquid crystal display backlight unit, characterized in that the parallel section of the step is opposed to the front surface 230 within a range of ± 0.5 °. The method of claim 7, A light guide plate for a liquid crystal display backlight unit, wherein the inner angle θ ₂ of the intaglio prism and the inner angle θ ₃ of the embossed prism are 60 to 100 °. The method of claim 5, wherein The interior of the stripe prism is a light guide plate for a liquid crystal display device backlight unit, characterized in that 70 to 85 degrees. The method of claim 7, wherein A light guide plate for a liquid crystal display backlight unit, characterized in that the ratio of the height of the intaglio prism and the embossment prism is in the range of 1: 2 to 2: 1. The method according to any one of claims 1 to 4, A light guide plate for a liquid crystal display device backlight unit, wherein the height difference of each step shape: the light guide plate is in the range of 1: 120 kPa to 1: 1,200. The method according to claim 1 or 2, When the length of each step shape is constant, the ratio of the length Lx of each step: the length L ₀ of the entire light guide plate is in the range of 1: 100 to 1: 1,000. . The method according to claim 1 or 2, A light guide plate for a liquid crystal display backlight unit, wherein a ratio of an area occupied by a geometric reflector and a step shape on the rear surface of the light guide plate is 1: 100 to 1: 10,000. The method according to claim 1 or 2, A light guide plate for a liquid crystal display backlight unit, characterized in that dot prisms are formed on the rear stepped surface. The method of claim 16, The dot shape of the dot prisms is a light guide plate for a liquid crystal display device backlight unit, characterized in that consisting of a circle, oval, rhombus, rectangle or a combination thereof. The method according to claim 1 or 2, A light guide plate for a liquid crystal display device backlight unit, characterized in that the front surface prism having a predetermined cross-sectional shape is formed on the front surface. The method of claim 18, And a length direction of the front prism is perpendicular to a length direction of the rear stripe prism. The method of claim 18, A light guide plate for a liquid crystal display device backlight unit, characterized in that the cross section of the front prism is one of a triangle, a trapezoidal shape and an inverse groove shape having a predetermined radius of curvature on the side surface. The method of claim 18, The front prism is disposed on a predetermined separation plane light guide plate for the liquid crystal display device, characterized in that disposed. The method of claim 21, The area ratio of the front prism and the separation plane therebetween is in the range of 1: 0.5 to 1:10, the light guide plate for a liquid crystal display device backlight unit. The method of claim 18, A light guide plate for a liquid crystal display backlight unit, wherein the ratio of the height h ₂ : width w ₂ of the front prism is 0.3 to 0.6.

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