KR100879950B1 - Edge type backlight unit of using micro triangle lens pattern - Google Patents

Abstract

The present invention discloses a side dimming backlight device in which a micro triangular lens pattern (MICRO TRIANGLE LENS PATTERN) is formed on a lower surface of a light guide plate to improve brightness and screen quality. The present invention provides a light source, a light guide plate which is located on the side of the light source and converts the light incident from the light source into a surface light source and exits upward, and is located below the light guide plate and is incident to the rear of the light guide plate. In the side-illumination type backlight device including a reflecting plate for reflecting light forward, a micro triangular lens pattern is formed on the lower surface of the light guide plate at random intaglio by varying the density in the anti-incident surface direction from the incident surface to which the line light source is incident And it is arranged to improve the light brightness and the screen quality. Therefore, the present invention can improve the screen quality by randomly arranging the micro triangular lens pattern (MTL) to suppress the interference pattern, and has a double brightness synergy effect by the pattern on the lower surface and the pattern on the upper surface, and the existing prism sheet ( Manufacturing cost can be reduced by changing 2 sheets of Prism Sheet to 2 sheets or less.

Backlight, Light Guide Plate, Micro Triangle Lens Pattern, Prism Pattern

Description

Side dimming backlight device using micro triangular lens pattern {EDGE TYPE BACKLIGHT UNIT OF USING MICRO TRIANGLE LENS PATTERN}

1 is a cross-sectional view showing the overall structure of a side-illuminated backlight according to the prior art,

Figure 2 is a cross-sectional view showing a light guide plate according to the prior art,

3 is a perspective view showing a lower surface of the light guide plate of the side-illuminated backlight according to the present invention;

4 is a front and side views of the light guide plate lower surface pattern shown in FIG. 3;

5 is an example of a light guide plate lower surface pattern shown in FIG.

6 is a perspective view showing an upper surface of a light guide plate of the side-illuminated backlight device according to the present invention;

FIG. 7 is a view for explaining a pattern of an upper surface of the light guide plate shown in FIG. 6;

FIG. 8 is a diagram illustrating various pattern examples of the upper surface of the LGP illustrated in FIG. 6;

9 is a view showing a light path by the light guide plate pattern according to the present invention;

10 is a graph illustrating a comparison of left and right viewing angles of a light guide plate (LGP) according to a light guide plate pattern;

FIG. 11 is a graph illustrating an upper and lower viewing angles of LGPs according to LGP patterns. FIG.

** Explanation of symbols for main parts of drawings **

1: reflector 2,20: light guide plate

3: diffuser plate 4: prism sheet

5: protective sheet 6: light source

7: light source reflector 20d: light guide plate lower surface

20u: upper surface of the light guide plate 20i: incident surface

20r: incoming plane 22: micro triangle lens pattern

24: Prism pattern

The present invention relates to a backlight unit, and more particularly, to a side dimming type backlight device in which a micro triangular lens pattern (MICRO TRIANGLE LENS PATTERN) is formed on a lower surface of a light guide plate to improve light brightness and screen quality.

In general, a backlight device of a liquid crystal display is a light source such as a cylindrical fluorescent lamp such as a Cold Cathode Fluorescent Lamp (CCFL), a Hot Cathode Fluorescent Lamp (HCFL), an External Electrode Fluorescent Lamp (EEFL), or a light emitting diode (LED). Devices, EL (Electro Luminescence) devices, etc. are mainly used, and are classified into side-lighting and direct-lighting backlight devices according to the manner in which the light sources are arranged. In general, side dimming backlight devices are mainly used in LCDs for notebooks or computer monitors because of their relatively thin thickness, and direct dimming backlight devices are mainly used in LCDs for large screens such as TVs due to high light efficiency.

In the conventional side-illuminated backlight device, as shown in FIG. 1, the fluorescent lamp 6, which is a linear light source, is positioned on the side of the light guide plate 2 that scatters the light of the linear light source and converts the light into a surface light source, and the fluorescent lamp 6 is It is enclosed with the lamp reflector 7 so that the light emitted from the fluorescent lamp 6 is directly or reflected by the lamp reflector 7 to be incident on the light guide plate 2. A reflecting plate 1 is positioned below the light guide plate 2, and a diffusion sheet 3 for scattering light emitted from the light guide plate 2 to equalize luminance by refraction of the light guide plate 2 and refracting the diffused light. Various sheets, such as the prism sheet 4 and the protective sheet 5, which condense and improve brightness, are located. The prism sheet 4 is divided into a vertical prism sheet 4-1 and a horizontal prism sheet 4-2, and the two prism sheets 4 overlap each other.

In the side-illumination type backlight device having such a structure, light emitted from the fluorescent lamp 6 is incident on the side incident surface of the light guide plate 2, and the light guide plate 2 scatters and equalizes the light of the fluorescent lamp received as a linear light source. The reflection plate 1 reflects the light from the light guide plate 2 downward to the upper side of the light guide plate 2 to increase the light efficiency. The diffusion sheet 3 located above the light guide plate 2 scatters the light emitted from the light guide plate 2 to improve brightness and appearance, and the prism sheet 4 refracts and condenses the diffused light to improve brightness. Let's do it.

However, in the conventional side-illuminated backlight device, as shown in FIG. 2, light is scattered due to an etching or printed pattern formed on the lower surface of the light guide plate 2 and emitted to the upper side of the light guide plate, so that the light collecting effect is increased. There is a problem of deterioration. That is, in the conventional light guide plate 2, as shown in FIG. 2, the emission directing angle is significantly laid out in the normal direction, and is emitted in a wide spread form, so that the light collecting effect in the normal direction is lowered on the upper prism sheet, and the large-sized etching on the lower side is performed. There is a problem that a diffusion sheet is required as a pattern. Referring to FIG. 2, it can be seen that the vertical angle θ _V1 of the light beam by the etching pattern is about 55 ° with respect to the normal line, and the horizontal angle θ _H1 is largely scattered by about 55 °.

The present invention has been proposed to solve the above problems, and an object of the present invention is to form a micro rectangular lens pattern (MRL), not an etching or a print pattern, on the lower surface of the light guide plate so that the brightness and screen quality are increased. It is to provide a side dimming backlight device.

The present invention for solving the above problems, a line light source, a light guide plate which is located on the side of the line light source and converts the light incident from the line light source to the surface light source and exits to the upper side, and located below the light guide plate In the side-illumination type backlight device including a reflecting plate for reflecting forward the light incident to the rear of the light guide plate,

On the lower surface of the light guide plate, a micro triangular lens pattern is formed and arranged in a random intaglio by varying the density in the direction of the anti-incident surface from the incident surface to which the line light source is incident, so as to improve light brightness and screen quality. do.

The size of the micro triangular lens pattern is horizontal (H) is 20㎛ to 80㎛ (20㎛≤H≤80㎛), vertical (V) is 1/4 to 1/2 of the horizontal (H) (H / 4 ≤ V ≤ H / 2), the height (D) is equal to the length (V) (D = V), the angle of the mountain (θ) is 80 ° to 120 ° (80 ° ≤ θ ≤ 120 °) The radius of curvature (R ₁ ) of the upper and left and right sides is less than 20㎛, and the radius of curvature (R ₂ ) of the front and back is 1.25R ₁ Below, the upper surface of the light guide plate is either a general prism pattern or a prism pattern having curvature formed only on a mountain, a discontinuous intaglio prism pattern, a discontinuous embossed prism pattern, a discontinuous embossed prism pattern having a curvature formed on a mountain, or a discontinuous embossed prism pattern having a flat acid The prism pattern of any one shape is embossed or engraved to condense light emitted from the lower side by the micro triangular lens pattern and output upward, thereby replacing the light collecting sheet with a diffusion sheet.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view showing a lower surface of the light guide plate of the side-illuminated backlight according to the present invention, FIG. 4 is a front view and a side view of the light guide plate lower surface pattern shown in FIG. 3, and FIG. 5 is an example of a lower surface pattern of the light guide plate shown in FIG. 3.

As shown in FIGS. 3 to 5, a micro triangle lens pattern (MTL) 22 is disposed on the lower surface 20d of the side-illuminated backlight according to the present invention from the incident surface 20i. The horizontal (H) direction of the micro triangular lens pattern (MTL) is formed in an intaglio shape in parallel with the incident surface 20i by varying the density in the direction of 20r), and is randomly arranged so as to be uniform on the light guide plate. It is comprised so that the center emission angle (theta) p of the light radiate | emitted may be ± 10 degrees or less ((theta) p <= 10 degrees).

As shown in FIG. 4, the size of the micro triangular lens pattern 22 formed intaglio on the lower surface of the light guide plate 20d according to the present invention is 20 μm to 80 μm (20 μm ≦ H ≦ 80 μm). The vertical (V) is 1/4 to 1/2 (H / 4≤V≤H / 2) of the horizontal (H), and the height (D) is the same size as the vertical (V) (D = V) It has a shape. The angle θ of the mountain is 80 ° to 120 ° (80 ° ≤θ≤120 °), and the radius of curvature R _{1 on} the upper and left sides is 20 μm or less (eg, 1 μm to 20 μm). The rear radius of curvature R ₂ is less than or equal to 1.25R ₁ .

FIG. 6 is a perspective view illustrating an upper surface of a light guide plate of the side-illuminated backlight device according to the present invention. FIG. 7 is a view for explaining a pattern of an upper surface of the light guide plate shown in FIG. 6, and FIG. It is a figure which shows a pattern example.

The light guide plate upper surface 20u of the side-illuminated backlight device according to the present invention has the light collected by the upper and lower viewing angles by the micro triangular lens pattern MTL of the lower surface 20d of the light guide plate 20 in order to further increase the luminance. It is configured to condense the left and right viewing angles by forming a deformed prism pattern (M-Prism Pattern) 24 at 20u).

According to the present invention, the size of the M-Prism Prism Pattern 24 formed perpendicularly to the incident surface 20i on the upper surface 20u of the light guide plate is shown in FIG. 7. _T ) or the angle (θ _B ) of the bone is 80 ° to 120 °, the width W is 10 μm to 60 μm (10 μm ≦ W ≦ 60 μm), and the peak (R _T ) or valley (R) of the prism _B ) the curvature of the structure (W) is less than 1/2 or the flattened shape is arranged in a continuous or discontinuous (including variable pitch) in an embossed or intaglio.

As shown in FIG. 8, the shape of the deformed prism pattern 24 may be modified in a wide variety of shapes. (A) is an example of a general prism pattern, and (B) is a shape of a prism pattern having curvature only on a mountain. (C) is an example of a discontinuous embossed prism pattern, (d) is an example of a discontinuous embossed prism pattern, (e) is an example of a discontinuous embossed prism pattern with curvature formed on the mountain, and (b) is an acid An example of a flat discrete embossed prism pattern.

9 is a view showing a light path by the light guide plate pattern according to the present invention.

According to the present invention, in the structure in which the micro triangular lens pattern 22 is formed on the lower surface 20d of the light guide plate and the prism pattern 24 is formed on the upper surface 20u, the incident surface 20i is incident from the light source 6 on the side surface. As shown in Fig. 9, the path of the reflected light is reflected by the micro triangular lens pattern 22 to the upper side and the vertical angle θ _V2 of the light beam emitted through the upper prism pattern 24 is relative to the normal line. It is about 10 degrees, and it can be seen that the horizontal angle θ _H2 is about 3 degrees.

FIG. 10 is a graph showing left and right viewing angles of the LGP according to the LGP pattern, and FIG. 11 is a graph showing upper and lower viewing angles of the LGP according to the LGP pattern.

Referring to FIG. 10, the K1 graph is a graph showing left and right viewing angle characteristics of a light guide plate (LGP) of a conventional pattern, and K2 is a left and right LGP when the micro triangular lens pattern 22 is formed on the bottom surface 20d of the light guide plate according to the present invention. K3 is a graph showing the viewing angle characteristics, and K3 is the left and right viewing angle characteristics of LGP when the micro triangular lens pattern 22 is formed on the lower surface 20d of the light guide plate and the prism pattern 24 is formed on the upper surface 20u of the light guide plate according to the present invention. A graph representing.

Referring to FIG. 11, the G1 graph is a graph showing the LGP upper and lower viewing angle characteristics of the conventional pattern, and G2 is the LGP upper and lower viewing angle characteristics when the micro triangular lens pattern 22 is formed on the lower surface of the light guide plate 20d according to the present invention. G3 is a graph showing the LGP upper and lower viewing angle characteristics when the micro triangular lens pattern 22 is formed on the lower surface of the light guide plate 20d and the prism pattern 24 is formed on the upper surface of the light guide plate 20u according to the present invention. .

According to the graph characteristic shown, it can be seen that the viewing angle characteristic of the light guide plate on which the patterns 22 and 24 according to the present invention are formed is improved than the viewing angle characteristic of the light guide plate according to the conventional pattern.

Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above-described embodiments, and various changes may be made by those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention. It may be changed and implemented.

As described above, the present invention applies a micro triangular lens pattern (MTL) to a lower surface of a side-illuminated backlight LGP having a light source positioned on a side thereof, thereby emitting light that is incident on the incident surface and totally reflected in the incident surface. By emitting in a direction perpendicular to the plane, the prismatic sheet can be replaced with a diffusion sheet. That is, the central exit angle of the vertical distribution may be converged to less than 10 ° by a fine micro triangular lens pattern (MTL Pattern) on the lower surface of the light guide plate to replace the prismatic sheet with a diffusion sheet.

In addition, the present invention can improve the screen quality by randomly arranging the micro triangular lens pattern (MTL) to suppress the interference pattern generated by a certain pattern, the lower surface of the micro triangular lens pattern (MTL) The upper and lower viewing angles are condensed and the emitted light is further condensed by the upper and lower prism patterns to double the viewing angle distribution, thereby increasing the brightness, and changing the existing prism sheet to 2 or less diffusion sheets. Can reduce the cost.

Claims (4)

A light guide plate positioned at a side of the light source and converting light incident from the line light source into a surface light source and exiting upward; a light guide plate positioned below the light guide plate to the rear of the light guide plate to the front In the side-illumination type backlight device comprising a reflecting plate, The lower surface of the light guide plate Horizontal (H) is 20 µm to 80 µm (20 µm ≤ H ≤ 80 µm), Vertical (V) is 1/4 to 1/2 (H / 4 ≤ V ≤ H / 2) of the horizontal H , The height (D) is equal to the length (V) (D = V), the angle of the mountain (θ) is 80 ° to 120 ° (80 ° ≤ θ ≤ 120 °), the radius of curvature of the upper and left and right ( R ₁ ) is a micro triangular lens pattern having a diameter of 1 μm to 20 μm is randomly formed in an intaglio direction at different densities in the direction of the incidence plane from the plane of incidence from which the line light source is incident, so that the horizontal H is parallel to the plane of incidence. Arranged in On the upper surface of the light guide plate The prism pattern of any one of the prism pattern or the prism pattern having curvature only on the mountain, the discontinuous intaglio prism pattern, the discontinuous embossed prism pattern, the discontinuous embossed prism pattern having the curvature formed on the mountain, or the discontinuous embossed prism pattern having the flat surface is the incident surface. It is formed perpendicular to the angle of the prism pattern (θ _T ) or the angle of the valley (θ _B ) of 80 ° to 120 °, the width (W) is 10㎛ to 60㎛ the micro triangular lens pattern By condensing the light emitted from the lower side and exiting the upper side to replace the light collecting sheet with the diffusion sheet Side dimming backlight device, characterized in that to improve the brightness and screen quality. delete delete delete

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