KR101956046B1 - Member for controlling luminous flux and display device having the same - Google Patents

Abstract

A light flux control member and a display device are disclosed. The light flux controlling member includes an incident surface on which light is incident; A refracting surface on which light from the incident surface is emitted; And a rear surface extending from the incident surface to the refracting surface, wherein a central axis extending from the center of the incident surface to the center of the refracting surface is defined, and a first direction perpendicular to the central axis is defined, The distance between the first refracting surface and the central axis is gradually decreased from the rear surface with respect to the first direction.

Description

TECHNICAL FIELD [0001] The present invention relates to a light flux control member and a display device including the light flux control member.

Embodiments relate to a light flux control member and a display device including the same.

2. Description of the Related Art [0002] Liquid crystal displays (LCDs) are becoming more and more widespread due to features such as light weight, thinness, and low power consumption driving. According to this trend, liquid crystal display devices are used in office automation equipment, audio / video equipment, and the like. The liquid crystal display device displays a desired image on the screen by controlling the amount of transmitted light according to a video signal applied to a plurality of control switches arranged in a matrix form.

Since the liquid crystal display device is not a self-luminous display device, a backlight unit for providing light to the back of a liquid crystal display panel on which an image is displayed is provided.

A liquid crystal panel including a color filter substrate and an array substrate interposed between the color filter substrate and the array substrate, and a backlight unit for emitting light to the liquid crystal panel .

The backlight unit used in such a liquid crystal display device can be generally divided into an edge type backlight unit or a direct type backlight unit.

The edge type backlight unit includes a light guide plate and light emitting diodes. The light emitting diodes are disposed on the side surface of the light guide plate, and the light guide plate guides the light emitted from the light emitting diode through total reflection or the like and emits toward the liquid crystal panel.

The direct type backlight unit does not use a light guide plate, and the light emitting diodes are disposed on the rear surface of the light guide plate. Accordingly, the light emitting diodes emit light toward the rear surface of the liquid crystal panel.

Such a backlight unit must emit light uniformly toward the liquid crystal panel. That is, efforts are being made to improve the luminance uniformity of the liquid crystal display device.

The embodiment aims to provide a light flux control member and a display device which have improved luminance uniformity and can be easily manufactured.

The light flux control member according to an exemplary embodiment includes an incident surface on which light is incident; A refracting surface on which light from the incident surface is emitted; And a rear surface extending from the incident surface to the refracting surface, wherein a central axis extending from the center of the incident surface to the center of the refracting surface is defined, and a first direction perpendicular to the central axis is defined, The distance between the first refracting surface and the central axis is gradually decreased from the rear surface with respect to the first direction.

A display device according to an embodiment includes a driving substrate extending in a second direction; A light source disposed on the driving substrate; A light flux control member disposed on the driving substrate and covering the light source; And a display panel on which light from the light flux control member is incident, wherein the light flux control member includes a rear surface opposed to the drive substrate, intersects the second direction, and is perpendicular to the optical axis of the light source And a second distance from the light source to the outer surface of the rear surface is larger than a first distance from the light source to the outer surface of the rear surface with respect to the first direction.

The display device according to the embodiment extends the light flux control members in the second direction. Accordingly, the light emitted from the light sources is further diffused in the first direction perpendicular to the second direction than the second direction. At this time, the light sources are arranged in rows in a direction substantially parallel to the second direction. Also, the light sources are arranged densely in the second direction, and are arranged less densely in the first direction.

Accordingly, the light having passed through the light flux controlling member is incident on the display panel as a whole with a uniform luminance.

That is, even if the number of rows in which the light sources are arranged is reduced by the light flux control member, the display apparatus according to the embodiment can have a high luminance uniformity as a whole. That is, even if the interval between the rows of the light sources is increased, the brightness uniformity in the second direction can be improved by the light flux control members.

Therefore, the display device according to the embodiment can reduce the number of rows of the light sources and reduce the number of circuit boards to be used. Therefore, the display device according to the embodiment can be easily manufactured at a low cost.

1 is an exploded perspective view showing a light emitting device according to an embodiment.
2 is a cross-sectional view illustrating a light emitting device according to an embodiment in a first direction.
3 is a cross-sectional view illustrating a light emitting device according to an embodiment in a second direction.
4 and 5 are views illustrating a process of forming a light flux control member.
6 is an exploded perspective view showing a liquid crystal display device according to an embodiment.
FIG. 7 is a cross-sectional view showing a section cut along AA 'in FIG. 6; FIG.
8 is a view showing the path of light emitted from the light flux control member with reference to the first direction.
Fig. 9 is a diagram showing the path of light emitted from the light flux control member with reference to the second direction. Fig.

In the description of the embodiments, it is described that each panel, sheet, member, guide, unit or the like is formed "on" or "under" of each panel, sheet, member, In this case, "on" and "under " all include being formed either directly or indirectly through another element. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

1 is an exploded perspective view showing a light emitting device according to an embodiment. 2 is a cross-sectional view illustrating a light emitting device according to an embodiment in a first direction. 3 is a cross-sectional view illustrating a light emitting device according to an embodiment in a second direction. 4 and 5 are views illustrating a process of forming a light flux control member.

1 to 5, the light emitting device according to the embodiment includes a light flux control member 10, a light source, for example, a light emitting diode 20, and a driving substrate 30. [

The light flux control member 10 is disposed on the driving substrate 30. The light flux control member 10 covers the light emitting diode 20. The light flux controlling member 10 can accommodate part or all of the light emitting diode 20.

Light emitted from the light emitting diode 20 is incident on the light flux control member 10. The light flux control member 10 is disposed directly on the light emitting diode 20 and light from the light emitting diode 20 can be directly incident on the light flux control member 10.

The light flux control member 10 includes an incident surface 210, refracting surfaces 110, 120, and 130, and a rear surface 220.

The incident surface 210 is a surface on which light is incident from the light emitting diode 20. The incident surface 210 is a surface facing the light source. The incident surface 210 may be in direct contact with the light source. More specifically, the incident surface 210 may be a surface directly contacting the light source. Particularly, the light flux control member 10 may be formed with a recess 200.

The concave portion 200 corresponds to the light emitting diode 20. Also, the recess 200 is opposed to the depression 100. The concave portion 200 is formed below the light flux control member 10. That is, the concave portion 200 is formed below the light flux control member 10.

The light emitting diode 20 is disposed in the concave portion 200. More specifically, part or all of the light emitting diode 20 is disposed in the concave portion 200. That is, part or all of the light emitting diode 20 is disposed in the light flux control member 10.

At this time, light emitted from the light emitting diode 20 may be incident through the inner surface of the recess 200. Accordingly, the inner surface of the concave portion 200 may be an incident surface 210 on which light is incident. That is, most light can be incident on the light flux control member 10 through the inner surface of the recess 200.

Alternatively, the light flux control member 10 may not have the concave portion 200 formed thereon. At this time, the light emitting diode 20 may be disposed on the flat rear surface 220 of the light flux control member 10. At this time, a part of the rear surface 220 may be an incident surface 210.

The light flux control member 10 is formed with a depression 100. The depression (100) is formed on the light flux control member (10). The depression (100) corresponds to the light emitting diode (20). Also, the depression 100 is recessed toward the light emitting diode 20. In more detail, the depression 100 is recessed toward the light emitting diode 20. The depression (100) is formed in the central portion of the light flux control member (10).

The center 101 of the inner surface of the depression 100 is disposed on the optical axis OA of the light emitting diode 20. That is, the optical axis OA of the light emitting diode 20 passes through the center 101 of the inner surface of the depression 100.

The center 201 of the inner surface of the concave portion 200 may be disposed on the optical axis OA of the light emitting diode 20. The optical axis OA of the light emitting diode 20 can pass through the center 101 of the inner surface 110 of the depression 100 and the center 201 of the inner surface of the recess 200.

The refracting surfaces 110, 120, and 130 emit light from the incident surface 210. The refracting surfaces 110, 120, and 130 refract light incident on the light flux control member 10. The refracting surfaces 110, 120, and 130 may be formed as a curved surface as a whole. The refracting surfaces 110, 120 and 130 include a first refracting surface 110, a second refracting surface 120, and a recessed surface 130.

The first refracting surface 110 extends to the rear surface 220. The first refracting surface 110 may be bent from the rear surface 220 and extend upward. The first refracting surface 110 may extend upward from the upper surface of the driving substrate 30.

That is, the first refracting surface 110 extends from the rear surface 220 to the second refracting surface 120. The rear surface 220 is opposed to the driving substrate 30. The rear surface 220 extends from the inner surface of the recess 200 in a direction away from the optical axis OA of the light emitting diode 20.

The first refracting surface 110 may be a curved surface. More specifically, the first refracting surface 110 may be spherical or aspherical. The first refracting surface 110 may emit light from the light emitting diode 20. Also, the first refracting surface 110 may refract light reflected by the recessed surface 130.

The first refracting surface 110 extends upward from the rear surface 220. That is, the distance from the optical axis OA of the light emitting diode 20 to the first refracting surface 110 may gradually increase as the distance from the rear surface 220 increases. The distance from the optical axis OA of the light emitting diode 20 to the first refracting surface 110 may gradually increase as the distance from the driving substrate 30 increases. That is, the first refracting surface 110 may have an undercut structure with respect to the upper surface of the driving substrate 30.

The second refracting surface 120 extends downward from the outer periphery of the depressed portion 100. The second refracting surface 120 is curved from the first refracting surface 110 and extends to the outer surface of the recess surface 130. At this time, the distance between the second refracting surface 120 and the optical axis OA of the light emitting diode 20 may decrease as the distance from the rear surface 220 increases. That is, the second refracting surface 120 may be closer to the optical axis OA of the light emitting diode 20 as the distance from the first refracting surface 110 increases.

The second refracting surface 120 may be spherical or aspherical. The second refracting surface 120 may refract light reflected by the recess surface 130. More specifically, the second refracting surface 120 can refract light reflected by the recess surface 130 laterally, side-upwardly, or downwardly.

 The second refracting surface 120 may surround the optical axis OA of the light emitting diode 20. In addition, the second refracting surface 120 may surround the circumference of the recessed surface 130.

The recessed surface 130 is an inner surface of the depression 100. The recessed surface 130 may reflect light from the light emitting diode 20 laterally, side-upwardly, or downwardly.

The recessed surface 130 extends from the optical axis OA of the light emitting diode 20. More specifically, the recessed surface 130 extends in a direction away from the optical axis OA of the light emitting diode 20. The direction away from the optical axis OA of the light emitting diode 20 may be an outer direction perpendicular to or inclined from the optical axis OA of the light emitting diode 20. [ More specifically, the recessed surface 130 extends laterally upward from the optical axis OA of the light emitting diode 20. The recessed surface 130 extends from the optical axis OA of the light emitting diode 20 to the outside. Here, the "optical axis" refers to the traveling direction of light from the center of a three-dimensional luminous flux from the point light source.

The optical axis OA of the light emitting diode 20 may pass through the center 201 of the incident surface 210 and the center 101 of the refracting surfaces 110, 120 and 130. That is, the optical axis OA of the light emitting diode 20 may substantially coincide with the central axis of the light flux control member 10. [ Here, the central axis may be a straight line passing through the center 201 of the incident surface 210 and the center 101 of the refracting surfaces 110, 120 and 130.

The distance between the recessed surface 130 and the optical axis OA of the light emitting diode 20 may become larger as the distance from the light emitting diode 20 increases. More specifically, the distance between the recessed surface 130 and the optical axis OA of the light emitting diode 20 can become proportionally larger as the distance from the light emitting diode 20 increases.

The recessed surface 130 may reflect light emitted from the light emitting diode 20. More specifically, the recessed surface 130 may totally reflect light emitted from the light emitting diode 20. Accordingly, the recessed surface 130 can prevent a hot spot, which is formed by concentrating light excessively at the central portion of the light flux control member 10, from being generated. The recessed surface 130 may reflect light from the light emitting diode 20 to the second refracting surface 120 or the first refracting surface 110.

Here, the curvature means a shape that is gently bent. For example, if two faces are curved to form a curved surface with a radius of curvature greater than about 0.1 mm, then the two faces are said to be curved. Here, the curvature means that the curvature of curvature changes and the curvature changes. For example, when the convex curved surface is bent and changed to a concave curved surface, the convex curved surface and the concave curved surface are curved.

The rear surface 220 extends from the incident surface 210. The rear surface 220 is opposed to the upper surface of the driving substrate 30. The rear surface 220 may be in direct contact with the upper surface of the driving substrate 30. The rear surface 220 may be directly opposed to the upper surface of the driving substrate 30.

The rear surface 220 may be planar. In addition, the rear surface 220 may surround the incident surface 210. That is, the rear surface 220 may extend along the periphery of the light emitting diode 20.

The second refracting surface 120 and the first refracting surface 110 are formed on the side of the light flux control member 10.

The light flux control member 10 is transparent. The light flux control member 10 may have a refractive index of about 1.4 to about 1.5. The light flux controlling member 10 may be formed of a transparent resin. More specifically, the light flux controlling member 10 may include a thermoplastic resin. More specifically, the light flux controlling member 10 may include a silicone resin. Examples of materials used for the light flux control member 10 include polydimethylsiloxane (PDMS).

The light flux controlling member 10 can have high elasticity. Young's modulus of the light flux control member 10 may be about 100 kPa to about 1000 kPa.

When a first straight line extending from a center 201 of the incident surface 210 to a portion where the first refracting surface 110 and the second refracting surface 120 meet is defined, The angle [theta] 1 between the optical axis OA of the diode 20 can be about 30 [deg.] To about 85 [deg.]. More specifically, the angle? 1 between the first straight line and the optical axis OA of the light emitting diode 20 may be between about 45 ° and about 70 °.

A second straight line extending from the center 201 of the incident surface 210 to the portion where the second refracting surface 120 and the recessed surface 130 meet may be defined. The angle between the optical axis OA of the light emitting diode 20 and the second straight line may be between about 5 degrees and about 25 degrees.

The angle? 3 between the first refracting surface 110 and the upper surface of the driving substrate 30 may be about 5 ° to about 70 °. Further, an angle [theta] 4 between the first refracting surface 110 and the rear surface 220 may be about 110 [deg.] To about 175 [deg.].

The light flux controlling member 10 may have an anisotropic structure. The light flux control member 10 may have a plane symmetry structure, not a line symmetry. The light flux controlling member 10 may have a shape extending in the second direction. That is, the light flux controlling member 10 may be relatively long in the second direction and relatively short in the first direction crossing the second direction. For example, when viewed from the top side, the light flux control member 10 may have an elliptical structure.

The first direction and the second direction intersect with each other. More specifically, the first direction and the second direction may intersect perpendicularly to each other. In addition, the first direction and the optical axis OA of the light emitting diode 20 may be perpendicular to each other. In addition, the second direction and the optical axis OA of the light emitting diode 20 may be perpendicular to each other.

In addition, the first direction and the second direction pass through the optical axis OA of the light emitting diode 20.

2, a first distance from the optical axis OA of the light emitting diode 20 to a portion where the rear surface 220 and the first refracting surface 110 meet, with respect to the first direction, D12) is defined. 3, from the optical axis OA of the light emitting diode 20 to the portion where the rear surface 220 and the first refracting surface 110 meet, Distance D22 is defined. At this time, the first distance D12 is smaller than the second distance D22. The ratio of the first distance D12 and the second distance D22 may be about 1: 1.3 to about 1: 5. The distance from the light emitting diode 20 to the outer surface of the rear surface 220 may be a distance from the light emitting diode 20 to the outer surface of the rear surface 220 with reference to the second direction. Lt; / RTI >

2, from the optical axis OA of the light emitting diode 20 to the portion where the first refracting surface 110 and the second refracting surface 120 meet, The distance D11 is defined. 3, from the optical axis OA of the light emitting diode 20 to the portion where the first refracting surface 110 and the second refracting surface 120 meet, with respect to the second direction, A fourth distance D21 is defined. At this time, the third distance D11 may be smaller than the fourth distance D21. The ratio of the third distance D11 and the fourth distance D21 may be about 1: 1.3 to about 1: 5.

2, from the optical axis OA of the light emitting diode 20 to the portion where the recessed surface 130 and the second refracting surface 120 meet, with respect to the first direction, The distance D13 is defined. 3, the distance from the optical axis OA of the light emitting diode 20 to the portion where the recessed surface 130 and the second refracting surface 120 meet, A sixth distance D23 is defined. At this time, the fifth distance D13 may be smaller than the sixth distance D23. The ratio of the fifth distance D13 and the sixth distance D23 may be about 1: 1.3 to about 1: 5.

Also, the third distance D11 may be larger than the first distance D12. The third distance D11 may be greater than the fifth distance D13. The fourth distance D21 may be greater than the second distance D22. The fourth distance D21 may be greater than the sixth distance D23.

A first symmetry plane passing through the optical axis OA of the light emitting diode 20 and extending in the first direction may be defined. That is, the optical axis OA of the light emitting diode 20 may be disposed on the first symmetry plane. At this time, the light flux control member 10 may have a plane symmetric structure with respect to the first symmetry plane. In addition, the incident surface, the rear surface 220, and the refracting surface may have a plane symmetric structure with respect to the first symmetry plane. That is, the light flux control member 10 can be divided into two portions having the same size by the first symmetry plane.

A second symmetry plane passing through the optical axis OA of the light emitting diode 20 and extending in the second direction may be defined. That is, the optical axis OA of the light emitting diode 20 may be disposed on the second symmetry plane. At this time, the light flux control member 10 may have a plane symmetry structure with respect to the second symmetry plane. In addition, the incident surface, the rear surface 220, and the refracting surface may have a plane symmetrical structure with respect to the second symmetric surface. That is, the light flux control member 10 may be divided into two portions having the same size by the second symmetry plane.

Further, by the first symmetry plane and the second symmetry plane, the light flux control member 10 can be all substantially the same size, and can be quartered. Accordingly, the incident surface, the rear surface 220, and the refracting surface can be divided into quadrants by substantially the same size, all by the first and second symmetry planes.

2 and 3, the first refracting surface 110 extends upward and upward from the rear surface 220 with respect to the first direction and the second direction. That is, the distance from the optical axis OA of the light emitting diode 20 to the first refracting surface 110 may be gradually increased as the distance from the rear surface 220 increases with respect to the first direction and the second direction . The distance from the optical axis OA of the light emitting diode 20 to the first refracting surface 110 may gradually increase as the distance from the driving substrate 30 increases with respect to the first direction and the second direction. That is, the first refracting surface 110 may have an undercut structure with respect to the upper surface of the driving substrate 30 with respect to the first direction and the second direction.

The light flux control member 10 may be formed directly on the driving substrate 30. [ Further, the light flux control member 10 may be formed directly on the light emitting diode 20. The light flux control member 10 may be in direct contact with the driving substrate 30 and the light emitting diode 20. [ More specifically, the light flux control member 10 may be in direct contact with the driving substrate 30 and the light emitting diode 20.

The light flux control member 10 may be formed as follows.

Referring to FIG. 4, a resin composition 11 is disposed on a drive substrate 30 on which a light emitting diode 20 is mounted. The resin composition (11) may include a thermosetting resin, a thermoplastic resin or a photocurable resin.

Thereafter, the mold 12 is disposed on the driving substrate 30. The mold 12 is disposed to cover the light emitting diode 20. Accordingly, the resin composition (11) is placed in the molding groove (13) of the mold (12).

The molding groove 13 of the mold 12 may have substantially the same shape as the light flux control member 10 described above. That is, the inner diameter of the forming groove 13 may gradually increase and decrease from the inlet 14 toward the bottom. That is, the inlet of the forming groove 13 may have a smaller diameter than the inside of the forming groove 13.

Referring to Fig. 5, the resin composition 11 in the molding groove 13 can be cured or cooled by heat and / or light. Accordingly, the light flux control member 10 is formed in the molding groove 13.

Accordingly, the light flux control member 10 can be formed directly on the upper surface of the driving substrate 30 and the light emitting diode 20. That is, the light flux control member 10 may be formed in direct contact with the upper surface of the driving substrate 30 and the light emitting diode 20.

Thereafter, the mold 12 is disengaged from the light flux control member 10. At this time, since the light flux controlling member 10 has sufficient elasticity, even if the entrance 14 of the molding groove 13 is smaller than the inside of the molding groove 13, . Alternatively, when the mold 12 has high elasticity, the mold 12 can be easily removed.

For example, the Young's modulus of the mold 12 and the light flux control member 10 may be from about 100 kPa to about 1000 kPa.

The light flux control member 10 can be easily formed on the driving substrate 30 by suitably adjusting the elasticity of the light flux controlling member 10 or the mold 12. [ In particular, the first refracting surface 110 may be easily formed with an undercut structure.

Alternatively, the light flux control member 10 may be adhered to the driving substrate 30 by a bonding portion.

The light emitting diode 20 generates light. The light emitting diode 20 may be a point light source. The light emitting diode (20) is electrically connected to the driving substrate (30). The light emitting diode 20 may be mounted on the driving substrate 30. Accordingly, the light emitting diode 20 receives an electrical signal from the driving substrate 30. That is, the light emitting diode 20 is driven by the driving substrate 30, thereby generating light.

The driving substrate 30 supports the light emitting diode 20 and the light flux control member 10. In addition, the driving substrate 30 is electrically connected to the light emitting diode 20. The driving board 30 may be a printed circuit board. Further, the driving substrate 30 may be rigid or flexible.

Also, the driving substrate 30 may extend in the second direction. The driving substrate 30 may have a strip shape extending in the second direction.

In this embodiment, it is described that one light emitting diode and one light flux control member are disposed on one drive substrate, but the present invention is not limited thereto. For example, a plurality of light emitting diodes may be disposed on one driving substrate. In addition, a plurality of light flux control members may be disposed corresponding to each light emitting diode.

The light reflected by the recessed surface 130 may be selectively refracted by the second refracting surface 120 or the first refracting surface 110. In particular, the light flux control member 10 can be refracted at a desired angle based on the reflection angle at the recess surface 130.

Particularly, the first refracting surface 110 has a structure that is away from the optical axis OA of the light emitting diode 20 as it goes away from the rear surface 220. Accordingly, the first refracting surface 110 can effectively refract light incident directly through the incident surface 210 laterally or side-upward. Also, the first refracting surface 110 may reflect the light reflected by the recessed surface 130 and the second refracting surface 120 effectively or laterally or upwardly.

Accordingly, the light flux control member 10 can efficiently diffuse the light emitted from the light emitting diode 20 laterally.

Further, the light flux control member 10 can diffuse the light from the light emitting diode 20 in an anisotropic manner.

Therefore, the light emitting device according to the embodiment can have improved luminance uniformity and can be suitable for forming a planar light source.

6 is an exploded perspective view showing a liquid crystal display device according to an embodiment. Fig. 7 is a cross-sectional view showing a section taken along line A-A in Fig. 6. Fig. 8 is a view showing the path of light emitted from the light flux control member with reference to the first direction. Fig. 9 is a diagram showing the path of light emitted from the light flux control member with reference to the second direction. Fig. In this embodiment, the light emitting device described above is referred to. That is, the description of the light emitting device of the foregoing embodiment can be essentially combined with the description of this embodiment.

6 to 9, a liquid crystal display device according to an embodiment includes a liquid crystal display panel 200 and a backlight unit 100. FIG. The liquid crystal display panel 200 displays an image. Although not shown in detail, the liquid crystal display panel 200 includes a thin film transistor (TFT) substrate and a color filter substrate bonded together so as to face each other and maintain a uniform cell gap, Layer. The thin film transistor substrate includes a plurality of gate lines, a plurality of data lines intersecting the plurality of gate lines, and a thin film transistor (TFT) formed at an intersection of the gate lines and the data lines.

A gate driving printed circuit board (PCB) for supplying a scan signal to the gate line, a data driving printed circuit board (PCB) for supplying a data signal to the data line, .

The gate and data driving PCBs 210 and 220 are electrically connected to the liquid crystal display panel 200 by a chip on film (COF). Here, the COF may be changed to a TCP (Tape Carrier Package).

The liquid crystal display according to the embodiment includes a panel guide 240 for supporting the liquid crystal display panel 200 and a top case 240 for covering the edges of the liquid crystal display panel 200 and coupled to the panel guide 240 230).

The backlight unit 100 is configured to be a direct-down type provided in a large liquid crystal display device of 20 inches or more. The backlight unit 100 includes a bottom cover 110, a plurality of driving substrates 31 and 32, a plurality of light emitting diodes 21 and 22, a plurality of light flux control members 10 and optical sheets 120 ).

The bottom cover 110 has a box shape with an opened upper surface, and accommodates the printed circuit board 30. In addition, the bottom cover 110 supports the optical sheets 120 and the liquid crystal display panel 200.

The bottom cover 110 may be made of metal or the like. For example, the bottom cover 110 may be formed by bending or curving a metal plate or the like. That is, the driving substrates 31 and 32 are accommodated in a space formed by bending or curving.

In addition, the bottom surface of the bottom cover 110 may have a high reflectance. That is, the bottom of the bottom cover 110 may function as a reflective sheet. Alternatively, although not shown in the figure, a reflective sheet may be separately provided inside the bottom cover 110. [

The driving substrates 31 and 32 are disposed inside the bottom cover 110. The driving substrates 31 and 32 may be driving substrates for driving the light emitting diodes. The printed circuit board (30) is electrically connected to the light emitting diodes (21, 22). That is, the light emitting diodes 21 and 22 may be mounted on the driving substrates 30. [

As shown in FIG. 6, the driving substrates 31 and 32 may have a shape extending in a first direction. More specifically, the driving substrates 31 and 32 may extend in the first direction in parallel with each other. The driving substrates 31 and 32 may have a strip shape extending in the first direction. The number of the driving substrates 31 and 32 may be two or more. The number of the driving substrates 31 and 32 may be varied according to the area of the liquid crystal display panel 200. The driving substrates 31 and 32 may be disposed parallel to each other. The length of the driving substrates 31 and 32 may be varied according to the width of the liquid crystal display panel 200. The width of the driving substrates 31 and 32 may be about 5 mm to about 3 cm.

The driving substrates 31 and 32 are electrically connected to the light emitting diodes 21 and 22 and supply driving signals to the light emitting diodes 21 and 22. A reflective layer for improving the performance of the backlight unit 100 may be coated on the upper surfaces of the driving substrates 31 and 32. That is, the reflective layer may reflect upward the light emitted from the light emitting diodes 21 and 22.

The light emitting diodes 21 and 22 generate light using an electrical signal received through the driving substrates 31 and 32. That is, the light emitting diodes 21 and 22 are light sources for generating light. More specifically, each light emitting diode 20 is a point light source, and each of the light emitting diodes 20 is gathered to form a surface light source. Here, the light emitting diodes 21 and 22 are light emitting diode packages including light emitting diode chips.

The light emitting diodes 21 and 22 are mounted on the driving substrates 31 and 32. The light emitting diodes 21 and 22 emit white light. Alternatively, the light emitting diodes 21 and 22 may emit blue light, green light, and red light, respectively.

Further, the light flux control members are disposed on the driving substrates 31 and 32. [ More specifically, the light flux control members are disposed on the light emitting diodes 21 and 22, respectively. The light flux control members may cover the light emitting diodes 21 and 22, respectively. The light emitting diodes 21 and 22 may include first light emitting diodes 21 and second light emitting diodes 22.

The first light emitting diodes 21 are disposed on the first driving substrate 31. The first light emitting diodes 21 may be mounted on the first driving substrate 31. More specifically, the first light emitting diodes (21) may be arranged such that the first light emitting diodes (21) are arranged in columns in the first direction. That is, the first light emitting diodes 21 may be mounted on the first driving substrate 31 in a line. In addition, the first light emitting diodes 21 may be spaced apart from each other by a predetermined distance D11.

The second light emitting diodes 22 are disposed on the second driving substrate 32. The second light emitting diodes 22 may be mounted on the second driving substrate 32. More specifically, the second light emitting diodes 22 may be arranged in rows in the first direction. That is, the second light emitting diodes 22 may be mounted on the second driving substrate 32 in a line. In addition, the second light emitting diodes 22 may be spaced apart from each other by a predetermined distance D22.

The first light emitting diodes 21 may be arranged in a first column and the second light emitting diodes 22 may be arranged in a second column. The first row and the second row are arranged side by side.

The interval D31 between the first light emitting diodes 21 is smaller than the interval D33 between the first and second columns. For example, the distance D33 between the first row and the second row is about 1.3 times to about 10 times, more specifically about 1.5 times the distance D31 between the first light emitting diodes 21 To about 3 times, more specifically, from about 2 times to about 2.5 times.

The distance D32 between the second light emitting diodes 22 is also smaller than the distance D33 between the first and second columns. For example, the distance D32 between the first and second rows may be about 1.3 times to about 10 times, more specifically about 1.5 times the distance D33 between the second light emitting diodes 22 To about 3 times, more specifically, from about 2 times to about 2.5 times.

That is, the intervals D31 and D32 of the light emitting diodes 21 and 22 may be greater than the distance D33 of the light emitting diodes 21 and 22 with respect to the first direction, It is smaller. That is, the light emitting diodes 21 and 22 are densely arranged with respect to the second direction, and may be arranged less densely with respect to the first direction.

8, although the light emitting diodes 21 and 22 are closely arranged in the second direction, the light flux control member 10 is less diffused in the second direction than the first direction . That is, with reference to the second direction, the light flux control member 10 emits light from the light emitting diodes 21 and 22 at a relatively small directivity angle.

9, even though the light emitting diodes 21 and 22 are arranged less densely in the first direction, the light flux control member 10 is arranged in the first direction more in the first direction than the second direction. . That is, with reference to the first direction, the light flux control member 10 emits light from the light emitting diodes 21 and 22 at a relatively large directivity angle.

The optical sheets 120 are disposed on the light emitting diodes 21, 22. The optical sheets 120 may be disposed on the bottom cover 110. The optical sheets 120 may cover the light emitting diodes 21 and 22.

The optical sheets 120 improve the characteristics of light passing therethrough. The optical sheets 120 include a diffusion sheet, a first prism sheet, and a second prism sheet.

The diffusion sheet is disposed on the light emitting diodes (21, 22). The diffusion sheet covers the light emitting diodes (21, 22). More specifically, the diffusion sheet may cover the light emitting diodes 21 and 22 as a whole.

Light emitted from the light emitting diodes 21 and 22 is incident on the diffusion sheet. Light from the light emitting diodes 21 and 22 can be diffused by the diffusion sheet.

The first prism sheet is disposed on the diffusion sheet. The first prism sheet may include a pattern having a pyramid shape. The first prism sheet can improve the straightness of light from the diffusion sheet.

The second prism sheet is disposed on the first prism sheet. The second prism sheet may include a pattern having a pyramid shape. The second prism sheet can further improve the linearity of light from the first prism sheet.

As described above, the liquid crystal display according to the embodiment further diffuses the light emitted from the light emitting diodes 21 and 22 in the first direction more than the second direction by using the light flux control member. At this time, the liquid crystal display according to the embodiment arranges the light emitting diodes 21, 22 more densely in the second direction and less densely in the first direction.

Accordingly, the liquid crystal display according to the embodiment can reduce the number of rows of the light emitting diodes 21 and 22. That is, in the liquid crystal display according to the embodiment, the light emitting diodes 21 and 22 are anisotropically arranged without being arranged at regular intervals regardless of the directions. The luminance unevenness that can be generated by the anisotropic arrangement of the light emitting diodes 21 and 22 is compensated by the anisotropic light diffusion of the light flux control member 10, Brightness. That is, light passing through the light flux control member 10 is incident on the liquid crystal display panel 200 as a whole with a uniform luminance.

That is, even if the number of rows in which the light emitting diodes 21 and 22 are arranged is reduced, the liquid crystal display according to the embodiment can have a high luminance uniformity as a whole by the light flux controlling member 10. That is, even if the distance between the rows of the light emitting diodes 21 and 22 increases, the brightness uniformity can be improved by the light flux control member 10.

Therefore, the liquid crystal display according to the embodiment can reduce the number of rows of the light emitting diodes 210, 220, and 230 and reduce the number of the driving substrates 30 used. Therefore, the liquid crystal display according to the embodiment can be easily manufactured at low cost.

In addition, the features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (12)

An incident surface on which light is incident;
A refracting surface on which light from the incident surface is emitted; And
And a rear surface extending from the incident surface to the refracting surface,
A central axis extending from the center of the incident surface to the center of the refracting surface is defined,
A first direction perpendicular to the central axis is defined,
The refracting surface
And a first refracting surface extending from the rear surface,
Wherein the distance between the first refracting surface and the central axis is gradually decreased from the rear surface with respect to the first direction. 2. The method of claim 1, wherein a second direction perpendicular to the central axis is defined,
Wherein the second direction intersects the first direction,
And the distance between the second refracting surface and the central axis is gradually decreased from the rear surface with respect to the second direction. 3. The image display apparatus according to claim 2, wherein a first distance from the central axis to a portion where the first refracting surface and the rear surface meet, with respect to the first direction is defined as a distance between the first refracting surface and the rear surface Lt; RTI ID = 0.0 > distance. ≪ / RTI > 4. The light flux controlling member according to claim 3, wherein the ratio of the first distance and the second distance is 1: 1.3 to 1: 5. The light flux control member according to claim 3, wherein the first direction and the second direction cross each other at right angles. 6. The method of claim 5, wherein a first symmetry plane passing through the central axis and extending in the first direction is defined,
Wherein the refracting surface is plane symmetry with respect to the first symmetry plane. 7. The method of claim 6, further comprising defining a second symmetry plane passing through the central axis and extending in the second direction,
Wherein the refracting surface is plane symmetry with respect to the second symmetry plane. Backlight unit; And
And a display panel disposed on the backlight unit,
The backlight unit includes:
A driving substrate;
A light source disposed on the driving substrate;
A light flux control member disposed on the light source; And
And an optical sheet disposed on the light flux control member,
Wherein the light flux control member comprises: an incident surface on which light is incident;
A refracting surface on which light from the incident surface is emitted; And
And a rear surface extending from the incident surface to the refracting surface,
A central axis extending from the center of the incident surface to the center of the refracting surface is defined,
A first direction perpendicular to the central axis is defined,
The refracting surface
And a first refracting surface extending from the rear surface,
Wherein the distance between the first refracting surface and the central axis is gradually decreased from the rear surface with respect to the first direction. The light source device according to claim 8, wherein the light flux control member is a display device 9. The method of claim 8, wherein a second direction perpendicular to the central axis is defined,
Wherein the second direction intersects the first direction,
And the distance between the second refracting surface and the central axis is gradually decreased from the rear surface with respect to the second direction. 11. The method of claim 10,
A first distance from the central axis to a portion where the first refracting surface and the rear surface meet is larger than a second distance from the first direction to a portion where the first refracting surface and the rear surface meet, Smaller display. An incident surface on which light is incident;
A refracting surface on which light from the incident surface is emitted; And
And a rear surface extending from the incident surface to the refracting surface,
A central axis extending from the center of the incident surface to the center of the refracting surface is defined,
A first direction perpendicular to the central axis and passing through the central axis is defined,
A second direction perpendicular to the central axis and passing through the central axis and intersecting with the first direction is defined,
A first distance from the central axis to a portion where the first refracting surface and the rear surface meet is larger than a second distance from the first direction to a portion where the first refracting surface and the rear surface meet, A smaller flux control member.

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