KR20080064262A - Lens and backlight unit and liquid crystal display having the same - Google Patents

Abstract

A lens for a liquid crystal display, and a back light unit and a liquid crystal display including the same are provided to obtain uniform luminosity by attaching the lens to a light source and increasing light distribution distance. A lens for a liquid crystal display includes a planar section, a curved section, a recess, and a refraction pattern(457). The planar section is planar. The curved section makes contact with the planar section and is opposite to the planar section. The curved section has a curved surface having a first curvature. The recess is formed on the planar section and has a curved surface having a second curvature. The refraction pattern is formed in the recess. The lens extends on one direction. The recess extends in the direction. The second curvature is larger than the second curvature.

Description

Lens for liquid crystal display, backlight unit and liquid crystal display having same {Lens and backlight unit and liquid crystal display having the same}

1 is a bottom perspective view showing an example of a light source unit having a lens according to an embodiment of the present invention.

FIG. 2 is a rear perspective view of the lens shown in FIG. 1.

3 is a sectional view of a light source unit with a lens according to the invention.

4 is a conceptual diagram showing the shape of the emitted light of the light source unit having a lens according to the present invention.

5A to 5D are graphs showing illuminance distribution diagrams of a light source unit having a lens according to the prior art and the present invention, respectively.

6A to 6C are graphs showing illuminance uniformity in an array of light source units having a lens according to the present invention, and FIGS. 7A to 7C are illuminance uniformity in an array of light source units not having a lens; Is a graph.

8 is a perspective view showing a lens according to another embodiment of the present invention.

9 is an exploded perspective view showing an example of a liquid crystal display including a light source unit having a lens according to the present invention.

* Description of the symbols for the main parts of the drawings *

100; A liquid crystal display panel 300; Upper chassis

400; A light source unit 410; Light emitting diode

420; Lamp 450; lens

455; Home 457; Refraction pattern

458; Reflector 600; Diffuser

700; Optical sheet 800; Mold frame

900; Lower chassis

The present invention relates to a lens for a liquid crystal display device and a backlight unit and a liquid crystal display device having the same, and more particularly, a lens for a liquid crystal display device and a backlight unit and a liquid crystal having the same structure having an easy structure for packaging a plurality of light sources. It relates to a display device.

As a light source of a backlight for a liquid crystal display device, a light bulb, a light emitting diode (LED), a fluorescent lamp, a metal halide lamp, and the like are mainly used. The dual light emitting diode has a long lifespan, does not require an inverter, is light and thin, enables uniform light emission, and has excellent low power consumption. Therefore, it is widely used as a backlight light source for small and medium-sized liquid crystal display devices.

A light emitting diode, which is a point light source among these backlight light sources, generally uses a lens to make the distribution of emitted light large and even. Such a lens is packaged on top of each light emitting diode to serve to diffuse light emitted from the light emitting diode to the front of the light emitting diode. If the size of the light emitting diode is small, it is difficult to package such a lens, and if the number of light emitting diodes is used, the cost of the lens is increased by that much, and the cost of packaging the lens is high, resulting in backlight and liquid crystal display. The manufacturing cost of the device increases.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-mentioned problems, and a technical object of the present invention is to provide a lens for a liquid crystal display device having a structure that is easy to package a plurality of light sources, and a backlight unit and a liquid crystal display device having the same. It is to.

Another object of the present invention is to increase the light distribution distance of the light source, ensuring a uniform illuminance. Disclosed is a lens for a liquid crystal display device capable of removing luminance unevenness and color unevenness caused by uneven illuminance distribution of a backlight unit, and a backlight unit and a liquid crystal display device having the same.

According to an embodiment of the present invention for achieving the object of the present invention, a flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a refractive pattern formed in the groove, wherein the lens extends in one direction, and the groove extends in the one direction.

The second curvature value is greater than the first curvature value.

The liquid crystal display lens is formed in a tunnel shape.

The groove has an elliptical shape in cross section cut in the direction perpendicular to the extension direction.

The refractive pattern includes an uneven portion formed on the curved surface of the groove.

The uneven portion is formed corresponding to the shape of the groove.

It further includes a reflector formed on the curved portion.

It further includes an uneven portion formed on the reflecting portion.

On the other hand, according to another embodiment of the present invention, a flat portion formed in a flat; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a refractive pattern formed in the groove, wherein the lens extends in one direction, and the groove extends in the one direction; And a light source unit configured of a light source disposed in the groove of the lens.

According to another embodiment of the present invention, a flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a reflector formed on the curved portion, wherein the lens extends in one direction, the groove extends in the one direction, and a refractive pattern is formed on at least one of the reflector and the groove. A lens for a liquid crystal display device; And a light source unit configured of a light source disposed in the groove of the lens.

The light source includes at least one light emitting diode.

And the light source comprises a lamp.

The light source units are configured in plural and arranged in an m × n matrix form (m and n are natural numbers), and each light source unit is disposed at a predetermined interval apart.

According to another embodiment of the present invention, a liquid crystal display panel for displaying an image; A backlight unit for providing light to the liquid crystal display panel; And an accommodation member for accommodating the backlight unit, wherein the backlight unit comprises a flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a refractive pattern formed in the groove, wherein the lens extends in one direction, and the groove extends in the one direction; And a light source unit composed of a light source disposed in the groove of the lens.

According to another embodiment of the present invention, a liquid crystal display panel for displaying an image; A backlight unit for providing light to the liquid crystal display panel; And an accommodation member for accommodating the backlight unit, wherein the backlight unit comprises a flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a reflector formed on the curved portion, wherein the lens extends in one direction, the groove extends in the one direction, and a refractive pattern is formed on at least one of the reflector and the groove. A lens for a liquid crystal display device; And a light source unit composed of a light source disposed in the groove of the lens.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a bottom perspective view showing an example of a light source unit having a lens according to an embodiment of the present invention, Figure 2 is a rear perspective view of the lens shown in Figure 1, Figure 3 is a lens according to the invention It is sectional drawing of the provided light source unit.

1 to 3, the light source unit 400 according to the present invention includes a light emitting diode 410 and a lens 450.

The light source unit 400 includes a plurality of light emitting diodes 410, and each of the light emitting diodes 410 is disposed in a line spaced apart at predetermined intervals.

The lens 450 is formed to extend in the direction in which the light emitting diodes 410 are disposed, that is, in the form of a bar, so as to collectively cover the plurality of light emitting diodes 410. 455 is formed, and the refraction pattern 457 is formed in the groove 455. The plurality of light emitting diodes 410 are disposed in the groove 455 of the lens 450 at predetermined intervals. The lenses 450 disposed on the plurality of light emitting diodes 410 change a path of the light emitted from the light emitting diodes 410. In this case, the lens 450 deflects the path of the light emitted upward from the light emitting diode 410 in the lateral direction, thereby spreading the distribution of the light emitted from the light emitting diode 410.

The lens 450 has a planar portion 451 formed in a planar shape, a curved portion 452 formed in a curved surface having a first curvature value C ₁ , and abutting with the planar portion 451. The groove 455 is formed on the 451 and includes a curved surface having a second curvature value C ₂ , and a refractive pattern 457 is formed on the curved surface of the groove 455. At this time, the refractive pattern 457 includes an uneven portion formed corresponding to the shape of the groove 455. In the present embodiment, the uneven portion is formed in the shape of a U-shaped groove, but is not limited thereto. Can be.

In addition, the lens 450 is formed to extend in one direction as a whole to form a bar, and the groove 455 formed on the flat portion 451 also extends in the direction in which the lens 450 is formed. At this time, the second curvature value C ₂ of the curved surface of the groove 455 is greater than the first curvature value C ₁ of the curved portion 452.

The lens 450 is formed in a bar shape in which one surface (ie, the flat portion 451) is flat and the other surface (ie, the curved portion 452) is curved, and the flat portion 451 of the lens, that is, the lens The groove 455 formed on the lower surface of the groove 455 is formed in an elliptical shape in a cross section cut in a direction perpendicular to the extension direction, that is, the lens 450 is formed in a tunnel shape as a whole.

In the present embodiment, the light source unit 400 is described as a light emitting diode as a light source, but the light source is not limited to the light emitting diode, and beneficiation such as a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL) or the like. Circles may be used.

4 is a conceptual diagram showing the shape of the emitted light of the light source unit having a lens according to the present invention.

Referring to FIG. 4, when looking at the path of the light emitted from the light emitting diode 410 disposed in the groove 455 of the lens 450, the light L ₁ emitted from the light emitting diode 410 proceeds upwards. The first refracted light is changed to the first refracted light L _{2 that} is laterally refracted while being incident on the curved surface having the second curvature value C ₂ , and the first refracted light travels inside the lens to convert the first curvature value C ₁ . While incident on the curved surface portion 452, the light is changed to the second refracted light L ₃ , which is refracted laterally, and emitted to the outside of the lens. That is, the light emitted from the light emitting diode is refracted in the horizontal direction (that is, the width direction of the lens) through the lens and emitted.

In addition, the light L ₁ emitted from the light emitting diode 410 mostly moves upward, and is incident on the refractive pattern 457 formed on the curved surface having the second curvature value C ₂ . ₄ ), and the third refracted light travels inside the lens and is incident to the curved portion 452 having the first curvature value C ₁ , and is changed to the fourth refracted light L ₅ , which is laterally refracted. And exits the lens. In this case, the third and fourth refracted light are refracted by the refracting pattern in a direction substantially intersecting with the first and third refracted light. That is, the light emitted from the light emitting diode is refracted and emitted in the vertical direction (ie, the longitudinal direction of the lens) through the lens.

As a result, since the light emitted from the light emitting diode 410 is refracted laterally through the lens 450 and is emitted, the light is not concentrated on the upper portion of the light emitting diode, and thus the distribution of the emitted light is widened. In addition, by forming the refractive pattern 457 inside the groove 455, the light component emitted in the vertical direction (that is, the longitudinal direction of the lens) is increased to obtain a uniform illuminance distribution in the horizontal direction and the vertical direction of the emitted light. Will be.

5A to 5D are graphs showing illuminance distribution diagrams of a light source unit having a lens according to the prior art and the present invention, respectively.

5A is an illuminance distribution diagram of light emitted through a bar-shaped lens without a refractive pattern formed, and FIGS. 5B and 5C are illuminance distribution diagrams of light emitted through a bar-shaped lens with a refractive pattern formed according to an embodiment of the present invention; 5D is an illuminance distribution diagram when no lens is provided. The bar-shaped lens used in FIGS. 5A to 5C has a total length of 300 mm, a width of 13.4 mm, and a height of 15.4 mm, a groove height of 5 mm, and a groove width of 4 mm. The formed refractive patterns are formed in the depth and width of 0.7mm and 1.2mm, respectively, and the refractive patterns formed in the lens shown in FIG. 5C are formed in the depth and width of 1.2mm and 1.2mm, respectively.

The illuminance distribution shown in FIG. 5A is compared with the illuminance distribution shown in FIG. 5D, compared with the distribution distance of light in the vertical direction (ie, the longitudinal direction of the lens), and the distribution distance of light in the horizontal direction (ie, the width direction of the lens). You can see the greater. The reason is that the light emitted from the light emitting diode is refracted and emitted in the horizontal direction through the lens, so that the light distribution distance in the horizontal direction becomes larger than the distribution distance of the light in the vertical direction.

The illuminance distributions shown in FIGS. 5B and 5C have increased light components emitted in the vertical direction (that is, the longitudinal direction of the lens) as compared with the illuminance distribution shown in FIG. 5A, so that the illuminance distribution in the horizontal and vertical directions of the emitted light is increased. Is uniform. In the simulation, the illumination distribution in the horizontal direction and the vertical direction is most uniformly distributed in the case of FIG. 5C in which the depth of the refractive pattern is deeper.

6A to 6C are graphs showing illuminance uniformity in an array of light source units having a lens according to the present invention, and FIGS. 7A to 7C are illuminance uniformity in an array of light source units not having a lens; Is a graph.

6A to 6C illustrate illuminance uniformity of light emitted through a lens having a refractive pattern according to an exemplary embodiment of the present invention after arranging a bar-shaped lens on a plurality of light emitting diodes disposed at predetermined intervals. 7A to 7C show illuminance uniformity of light emitted directly from a plurality of light emitting diodes arranged at predetermined intervals. 6A and 7A have a distance of 40 mm between adjacent light emitting diodes, FIGS. 6B and 7B have a distance of 30 mm between adjacent light emitting diodes, and FIGS. 6C and 7C have a distance of 20 mm between adjacent light emitting diodes.

In the case of the lens having the refractive pattern according to the exemplary embodiment of the present invention, when the distance between the light emitting diodes is 40 mm, the stain is visually recognized, but it can be seen that it is not visible at 30 mm or less. On the other hand, when the lens is not used, the stain is recognized even at 30 mm, and in the case of 20 mm, the stain is removed.

Therefore, when using a lens having a refractive pattern, the number of light emitting diodes can be reduced by increasing the spacing between the light emitting diodes, and the streaks can be removed by diffusing light in the same direction (circular) by the refractive pattern. do.

8 is a perspective view showing a lens according to another embodiment of the present invention.

Referring to FIG. 8, the lens 450 has a planar portion 451 formed in a planar surface, and a curved portion 452 formed in a curved surface having a first curvature value C ₁ opposite to and in contact with the planar portion 451. ), A groove 455 formed on the flat portion 451 and including a curved surface having a second curvature value C ₂ , and a reflecting portion 458 formed on the curved surface 452. The refractive pattern is formed on the reflector 458. In the present exemplary embodiment, the refractive pattern is formed only on the reflective part 458, but the refractive pattern 457 may also be formed on the curved surface of the groove 455, and the refractive pattern may be formed only on the curved surface of the groove 455. It may be. In this case, the refraction pattern 457 may have a concave-convex portion (FIG. 8A) extending in a direction perpendicular to the longitudinal direction of the lens, or a concave-convex portion (FIG. 8B) extending in the same direction as the length direction of the lens, or a U-shaped groove. It may include an uneven portion formed as, but is not limited thereto, and may be variously modified.

The lens 450 extends in one direction as a whole and is formed in a bar shape, and the groove 455 formed on the flat portion 451 also extends in the direction in which the lens 450 is formed. At this time, the second curvature value C ₂ of the curved surface of the groove 455 is greater than the first curvature value C ₁ of the curved portion 452.

The lens 450 is formed in a bar shape in which one surface (ie, the flat portion 451) is flat and the other surface (ie, the curved portion 452) is curved, and the flat portion 451 of the lens, that is, the lens The groove 455 formed on the lower surface of the groove 455 is formed in an elliptical shape in a cross section cut in a direction perpendicular to the extension direction, that is, the lens 450 is formed in a tunnel shape as a whole.

In the present exemplary embodiment, the reflector 458 is formed as a total reflection surface having an M-shaped cross section as a whole so that the light emitted through the curved portion 452 of the lens is totally reflected laterally. However, the shape of the reflector is not limited thereto, and may be variously modified to refract or reflect light in various directions.

9 is an exploded perspective view showing an example of a liquid crystal display including a light source unit having a lens according to the present invention.

Referring to FIG. 9, the LCD includes an upper chassis 300, a liquid crystal display panel 100, driving circuits 220 and 240, a diffusion plate 600, a plurality of optical sheets 700, and a light source unit 400. , A mold frame 800 and a lower chassis 900.

A predetermined storage space is formed inside the mold frame 800, and a backlight unit including a diffusion plate 600, a plurality of optical sheets 700, and a light source unit 400 is disposed in the storage space of the mold frame. The liquid crystal display panel 100 displaying an image is disposed above the backlight unit.

The driving circuits 220 and 240 are connected to the liquid crystal display panel 100, the gate side printed circuit board 224 for mounting a control IC and applying a predetermined gate signal to the gate line of the TFT substrate 120; A data side printed circuit board 244 for mounting a control IC (integrated circuit) and applying a predetermined data signal to a data line of the TFT substrate 120, a TFT substrate 120 and a gate side printed circuit board 224. Gate-side flexible printed circuit board 222 for connecting the circuit board), and data-side flexible printed circuit board 242 for connecting between the TFT substrate 120 and the data-side printed circuit board 244. The gate side and data side printed circuit boards 224 and 244 are connected to the gate side and data side flexible printed circuit boards 222 and 242 to apply a gate driving signal and an external image signal. In this case, the gate side and data side printed circuit boards 224 and 244 may be integrated to form a single printed circuit board. In addition, the flexible printed circuit boards 222 and 242 are equipped with a driving IC (not shown), so that the RGB (Read, Green, Blue) signals generated from the printed circuit boards 224 and 244, power supplies, and the like can be provided. To 100.

The light source unit 400 is a printed circuit board 410, a light emitting diode 410 disposed in a j × k matrix form on the printed circuit board 410, and an m × n matrix formed on the light emitting diode 410. And a lens 450. At this time, j = 9, k = 5, m = 1, n = 5, but j, k, m, n can be variously modified. Since the light emitted from the light emitting diode 410 is refracted laterally through the lens 450 and is emitted, the light is not concentrated on the top of the light emitting diode, and thus the distribution of the emitted light is widened.

The diffusion plate 600 and the plurality of optical sheets 700 are disposed above the light source unit 400 to uniform the luminance distribution of the light emitted from the light source unit 400. The upper chassis 300 is fastened to the mold frame 800 so as to cover an edge portion of the liquid crystal display panel 100, that is, the non-display area and a portion of the side and bottom surfaces of the mold frame 800. The lower chassis 900 is installed under the mold frame 800 to close the storage space of the mold frame.

In the present embodiment, the light emitting diode is described as an example of the light source of the light source unit.

What has been described above is only an exemplary embodiment of a lens for a liquid crystal display according to the present invention, a backlight unit having the same, and a liquid crystal display, and the present invention is not limited to the above-described embodiment, and the claims As claimed, any person having ordinary skill in the art without departing from the gist of the present invention will have the technical spirit of the present invention to the extent that various modifications can be made.

As described above, according to the present invention, the lens is formed long to package a plurality of light sources at the same time, thereby obtaining the effect of reducing the packaging time and cost of the light source unit.

By attaching the lens according to the invention on the light source, the light distribution distance is increased, so that uniform illuminance can be obtained. As a result, the light efficiency of the light source unit is increased, so that the number of light sources can be reduced. In addition, a uniform illuminance distribution can be obtained, whereby occurrence of luminance unevenness and color unevenness can be prevented.

Claims (18)

In a lens for a liquid crystal display device, The lens, A flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And And a refractive pattern formed in the groove, wherein the lens extends in one direction, and the groove extends in the one direction. The method of claim 1, The second curvature value is greater than the first curvature value lens for a liquid crystal display device. The method of claim 2, The lens for the liquid crystal display device is a lens for the liquid crystal display device, characterized in that formed in the form of a tunnel. The method of claim 3, And the groove is formed in an elliptical shape having a cross section cut in a direction perpendicular to the extension direction. The method of claim 2, The refractive pattern includes a concave-convex portion formed on the curved surface of the groove. The method of claim 5, And the concave-convex portion is formed corresponding to the shape of the groove. In a lens for a liquid crystal display device, The lens, A flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And It includes a reflector formed on the curved portion, And the lens extends in one direction, the groove extends in the one direction, and a refractive pattern is formed in at least one of the reflector and the groove. The method of claim 7, wherein And the refractive pattern includes an uneven portion. A flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a refractive pattern formed in the groove, wherein the lens extends in one direction, and the groove extends in the one direction; And And a light source unit composed of a light source disposed in the groove of the lens. The method of claim 9, And the light source comprises at least one light emitting diode. The method of claim 9, And the light source comprises a lamp. The method of claim 9, The light source unit is composed of a plurality of, m × n matrix form (m, n is a natural number) is disposed, each light source unit is a backlight unit, characterized in that arranged at a predetermined interval. A flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a reflector formed on the curved portion, wherein the lens extends in one direction, the groove extends in the one direction, and a refractive pattern is formed on at least one of the reflector and the groove. A lens for a liquid crystal display device; And And a light source unit composed of a light source disposed in the groove of the lens. The method of claim 13, And the light source comprises at least one light emitting diode. The method of claim 13, And the light source comprises a lamp. The method of claim 13, The light source unit is composed of a plurality of, m × n matrix form (m, n is a natural number) is disposed, each light source unit is a backlight unit, characterized in that arranged at a predetermined interval. A liquid crystal display panel for displaying an image; A backlight unit for providing light to the liquid crystal display panel; And An accommodation member for accommodating the backlight unit, wherein the backlight unit, A flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a refractive pattern formed in the groove, wherein the lens extends in one direction, and the groove extends in the one direction; And And a light source unit composed of a light source disposed in the groove of the lens. A liquid crystal display panel for displaying an image; A backlight unit for providing light to the liquid crystal display panel; And An accommodation member for accommodating the backlight unit, wherein the backlight unit, A flat portion formed in a plane; A curved surface portion formed in a curved surface having a first curvature value, the surface portion being connected to and opposed to the plane portion; A groove formed on the planar portion and including a curved surface having a second curvature value; And a reflector formed on the curved portion, wherein the lens extends in one direction, the groove extends in the one direction, and a refractive pattern is formed on at least one of the reflector and the groove. A lens for a liquid crystal display device; And And a light source unit composed of a light source disposed in the groove of the lens.

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