KR20110082679A

KR20110082679A - Light guide panel

Info

Publication number: KR20110082679A
Application number: KR1020100002533A
Authority: KR
Inventors: 김정순
Original assignee: 김정순
Priority date: 2010-01-12
Filing date: 2010-01-12
Publication date: 2011-07-20

Abstract

PURPOSE: A light guide panel is provided to improve brightness by forming a superior pattern. CONSTITUTION: In a V prism diffusion pattern(101), light diffusion by the light incident angle is low. Using an R groove diffusion pattern the light distribution amount is in large while restricting distribution angle. The width of light to x and y direction is 110 to 115 degree. If the light diffusion angle is reduced, the V direction(104) prism sheet is getting removed.

Description

Light guide panel {light guide panel}

The light source of the light guide plate, which is a backlight portion of a liquid crystal display (LCD), is switched from CCFL to LED, that is, from a linear light source to a point light source.

In a light guide plate using a point light source, a bright line appears much stronger than a line light source. The present invention relates to a structure that eliminates bright lines in a light guide plate using a point light source as a light source, creates a uniform surface light source, and further reduces high luminance and an optical sheet.

The reflective pattern of the light guide plate is screen-printed with a dot pattern, or diffusely reflects a fine lens shape (dot) from the light incidence part to the light incidence part by diffusing and reflecting a constant surface light source. This surface light source is diffused again in the diffusion sheet to make it more uniform, condensed and uniform light in the horizontal (V) and vertical (H) direction prism sheets, and finally more uniform in the protective sheet to increase the brightness and quality.

This process is essential for the backlight (BLU), and the optical sheet and the light guide plate are being developed as a method of reducing the optical sheet or performing a combination of two or three functions.

The brightness and efficiency of the light guide plate are better at reflecting prismatic reflecting patterns than diffuse reflecting dots. However, the prism reflection pattern shows strong bright lines when using a point light source. As a uniform surface light source with no bright lines, the brightness and efficiency should be increased. Furthermore, the optical sheet reduction and high brightness must be realized.

In the prism reflection pattern light guide plate using the point light source, the point light source should be linearized to achieve the above object. The light propagation structure of the dot reflection pattern light guide plate using a point light source (mobile, notebook PC, etc.) is largely as shown in FIG. Dispersion role), and screen section (light dispersion and emission as surface light source).

The light incident surface is a curved surface or a prism shape as shown in FIG. 2 and plays a role of partially distributing a uniform point light source in the light scattering progression section. In the dot reflection pattern light guide plate, the light incident surface is diffused again in the light scattering progression section and the screen section as shown in FIG. 3. Won out in won.

In the prism reflection pattern light guide plate, as shown in FIG. 4, it cannot be diffused in the screen section, but only diffuses in the dot and prism shapes in the light scattering progression section. At this time, the uniformity of dispersion (removal of light) of light is controlled by the vertex angle of the prism shape and the density of dots. If the size of the vertex angle is too small, the angle of dispersion of the light is large, and the dot also has a large angle of dispersion, so that the larger the angle of dispersion, the lower the emission amount, and the lower the luminance.

In the present invention, first, terms are defined as shown in FIG. 5 for better understanding and described below. The point light source used in small and medium sized LCDs mainly uses side view LEDs.

Its wide width (angle) is generally 110 ° to 115 ° in the x (V) and y (H) directions, and the angle of refraction in the light guide plate of the light incident on the planar light receiving surface (material: polycarbonate) is 0 ° to 35 Distributed in degrees (light distributed from 35 ° to 39 ° is very weak)

The more uniformly dispersed the light is, the more excellent the quality of the screen becomes. The smaller the scattering angle of the scattered light 105 is, the higher the luminance is and the prism sheet in the V direction 104 is also removed.

The shape of the V prism diffusion pattern 101 which is used for light scattering in the form of base has little dispersion along the direction of incident light and a large dispersion angle along the height of the H angle of the light. In addition, since the V reflecting surfaces are plane mirrors and all have the same inclination, light scattered in a similar direction is gathered into light of similar height. In order to disperse this again, dots are used on the lower surface of the light guide plate, which increases the dispersion angle.

In the present invention, the V prism shape installed in the light guide section on the light guide plate is formed using a curved prism shape as shown in FIG. 6 to make a dispersion hole having a greater variation in direction and height than before.

In the light guide plate, as shown in FIG. 7, a dispersion amount is large and a dispersion angle is limited while using the R groover diffusion pattern 102 as shown in FIG. 7. Alternatively, in order to create an evenly distributed light while removing the bright line, the shape of the R groover diffuser may be a large angle of vertex tangent and b is a small angle of tangent according to the positions of vertices where R of the same shape and size meet in FIG. 8-A. , c can be patterned gradually larger or smaller from a to b, where the V-type + R-type groover diffusion pattern can be ideally patterned as shown in FIG. 8-B.

The specular reflection prism reflection pattern 107 provided in the light guide plate bottom screen section is installed in the cross section as shown in FIG. 9. The protruding shape of Fig. 9-A is advantageous in injection molding, and the concave shape opposite to the same structure in Fig. 9-B is easy to manufacture in thermal transfer or the like. At this time, the curved surface is the same whether it is inside or outside.

In FIG. 9, the angle a is mainly used around 70 °. This is used to have a high H angle 106 when the transmitted light that is not specularly reflected in the reflective pattern is reflected back from the reflective sheet and is incident on the 70 ° surface as shown in FIG. 10. The back side is generally the opposite direction of the injection stream and does not significantly affect the formability. The change of ± 5 ° of 70 ° back and forth in actual production did not change much in brightness and formability.

According to the present invention, the angle of a is set at 45 ° ± 5 °. This is because the light transmitted in the front pattern is directly or directly reflected from the reflecting sheet and is refracted to the lower surface when incident on the 45 ° surface. The brightness is high by the method of specular reflection.

The shorter the distance the light travels, the less the number of reflections, refractions, in particular transmitted, and the closer the light is to the vertical, the higher the luminance. In general, the angles c to b in FIG. 9 are 25 degrees around the prism straight surface.

In the present invention, the tangent angle c of the vertex is 9 ± 3 °, and the tangent angle b of the curved prism end point is 30 ± 3 °. It has a large light receiving area and good injection moldability. The large H angle at specular reflection and the large reflection area of the H angle that can be emitted have another light scattering effect, and the glare and tilting of the general prism specular reflection pattern are eliminated. Etc., and the brightness is very high.

As described above, in the present invention, luminance and transferability (injection moldability) are very good in a pattern having excellent dispersion and condensing efficiency of light even while solving bright lines by uniformly dispersing light. Furthermore, finer pattern adjustment and mold processing can remove the V prism sheet.

In this case, there are advantages such as increased brightness due to sheet removal, increased merchandise, cost reduction, reduction in production costs such as reduced assembly process, and thinness.

1 is an overall configuration diagram of a dot reflection pattern light guide plate.
2 is a plan view of a light incident surface segment.
3 is a light diffusivity of a dot reflection pattern.
4 is an overall configuration diagram of a dot + prism reflective pattern light guide plate.
5 is a glossary interpretation and overall configuration of the prism reflection pattern LGP.
6 is a cross-sectional view of a curved prism shape.
7 is a plan view and a cross-sectional view of the bottom surface of the light guide plate of the R groove diffusion pattern arrangement analysis.
FIG. 8 is a cross-sectional view of the R groover diffusion pattern and the V + R type groover diffusion pattern during pattern change. FIG.
9 is a cross-sectional view of the semi-curved form of the specular reflection prism.
10 is a light progression diagram.
11 is a light progression diagram.
12 is a layout view of a curved V-prism pattern.
13 is a layout view when adjusting the diffusion pattern length.

As shown in FIG. 12, the curved V prism shape is installed in the V direction in the light scattering progression upper surface of the light guide plate as shown in FIG. 6, and a portion of the screen section of the light scattering progression is installed 108 in the same manner. The remaining portion is provided with the V + R groover diffusion pattern in FIG. 8 in the V direction. In the prism regular reflection pattern of the screen portion, a semi-curved prism regular reflection pattern of a = 45 °, b = 30 °, and c = 10 ° is provided in FIG. 9. At this time, the R and V angles of the semi-curved, curved V-prism, and V + R groover diffusion patterns are changed by the influence of the thickness, length, LED spacing, and length of the light scattering progression of the light guide plate.

In Example 1, the uniformity of light may be adjusted by adjusting the lengths of the curved V prism (upper surface) and the V + R groover diffusion pattern (lower surface) as shown in FIG. 13.

In the first embodiment, as shown in FIG. 8, the height of the pattern may be made smaller or larger, and the light uniformity may be finely adjusted by gradually narrowing and widening the interval of the same size pattern.

Example 2 and 3 are installed in parallel.

Claims

In the projected V-shaped prism regular reflection pattern, which is installed on the LCD light guide plate bottom surface in the direction intersecting with the light-receiving part from the light-receiving part, the shape of the V shape is perpendicular to one side of the light-receiving part direction V and V vertex. The angle of contact is 45 ° ± 5 °, the light-facing side V is one surface that is not flat, and the angle of tangency at the vertex of V is 9 ° ± 3 °, and the angle of tangency of the curved end point meeting the light guide plate bottom plane is A light guide plate provided with a semi-reflective prism reflective pattern having a shape of 30 ° ± 3 °.

The light guide plate of claim 1, wherein the specular reflection prism reflection pattern is provided such that the interval is wider in the light incident portion and becomes narrower toward the light facing portion.

The light guide plate of claim 2, wherein each of the patterns is divided into a plurality of patterns and the entire pattern is installed in a lattice pattern.

V prism groover shape A curved prism pattern that is a prism shape whose straight line is transformed into a curved line in a prism cross section.

A light guide plate having the same shape and direction as in claim 4 in a part of the screen side of the section between the light incident surface and the screen.

In the V-prism-shaped section, a circle inscribed to a portion of V, the upper part is V, and the lower part is a curved surface of the lower curved prism pattern, which is a combination of V and R, and the light guide plate is installed in the section between the incident surface and the screen. Light guide plates connected in the same direction.

The light guide plate of claim 4 or 6, wherein the light guide plate adjusts the light dispersion by lengthening or decreasing the length of the pattern for the purpose of uniform dispersion of the light.

The light guide plate which adjusts the dispersion of light by gradually increasing or decreasing the space | interval as a pattern of the same size and shape which is not connected in Claim 4 and 6, respectively.

The light guide plate according to claim 4 and 6, wherein the light guide plate adjusts the dispersion of light by gradually increasing or decreasing its height as a pattern of the same shape having only different heights.