KR102213297B1 - Lens for wide diffusion light - Google Patents

Abstract

Example is the lower surface; An incident surface formed concave inward from the lower surface; And an emission surface including a major axis and a minor axis in a plane through which light incident through the incident surface is emitted, wherein the emission surface is a curved upper surface, and a first surface disposed to face each other between the upper surface and the lower surface. A light diffusion lens including a first side surface and a second side surface, wherein a height H1 in a minor axis direction of each of the first side surface and the second side surface is smaller than a height H2 in the major axis direction. Accordingly, the image-light diffusion lens is formed to have a long axis and a short axis in a plane, and by designing a height of the long axis side higher than that of the short axis side, it is possible to prevent the occurrence of leakage light from the long axis side.

Description

Light diffusion lens {LENS FOR WIDE DIFFUSION LIGHT}

The embodiment relates to a light diffusing lens. More specifically, it relates to a light diffusing lens used in a backlight module of a liquid crystal display device to improve light uniformity.

With the focus on rapidly developing semiconductor technology, the demand for flat panel displays with improved performance while being compact and lightweight is exploding.

Among these flat panel displays, a liquid crystal display (LCD), which is in the spotlight in recent years, has advantages such as miniaturization, weight reduction, and low power consumption, so it can overcome the shortcomings of the existing cathode ray tube (CRT). It has gradually attracted attention as an alternative means of being used, and is currently installed and used in almost all information processing devices requiring a display device.

A liquid crystal display panel in a liquid crystal display device is a light-receiving element that cannot emit light by itself, and thus a backlight unit is provided under the liquid crystal display panel to provide light to the liquid crystal display panel. Here, the backlight unit includes a lamp, a light guide plate, a reflective sheet and an optical sheet. In addition, the lamp has a relatively low calorific value, generates white light close to natural light, and has a long lifespan, or an LED using a light emitting diode (hereinafter referred to as'LED') that has good color reproducibility and consumes low power. Use anticorrosive lamps. Conventionally, a cold-cathode ray tube type lamp has been used, but since the LED type lamp has the advantage of good color reproduction and low power consumption, LED type lamp products have begun to be used.

1 is a diagram showing an arrangement and light irradiation distribution of a plurality of lenses having isotropic surface irradiation characteristics.

Referring to FIG. 1, a plurality of conventional lenses 2 having isotropic surface irradiation characteristics may be disposed on a substrate 20 at equal intervals. In this case, the lens 2 may be disposed to cover the light source mounted on the substrate 20.

As shown in FIG. 1, there is a problem that a mura in the form of an arm is generated in a diagonal direction based on one lens 2. For example, when an LED is used as the light source, the light emitted by the LED tends to be concentrated toward the front of the LED due to strong straightness. Accordingly, there is an increasing demand for a technology for effectively and uniformly diffusing the light of a plurality of LEDs.

Therefore, a lens technology that can improve the uniformity of light by minimizing the dark area generated in the diagonal direction of the lens based on the design of an incidence surface on which light is incident and an emission surface from which light is emitted to implement anisotropic surface irradiation. The demand for this is also increasing.

The embodiment provides a light diffusion lens having an incident surface on which light is incident and an exit surface from which light is emitted so as to minimize dark portions occurring in a diagonal direction of a plurality of light diffusion lenses.

A light diffusion lens is provided that is formed to have a long axis and a short axis in a plane, and is designed to have a height on the long axis side higher than the height on the short axis side to prevent leakage of light from the long axis side.

The problem to be solved by the present invention is not limited to the problems mentioned above, and other problems that are not mentioned herein will be clearly understood by those skilled in the art from the following description.

The task according to the embodiment, the lower surface; An incident surface formed concave inward from the lower surface; And an emission surface including a major axis and a minor axis in a plane through which light incident through the incident surface is emitted, wherein the emission surface is a curved upper surface, and a first surface disposed to face each other between the upper surface and the lower surface. It includes a first side surface and a second side surface, and the height H1 in the minor axis direction of each of the first side surface and the second side surface is achieved by a light diffusing lens smaller than the height H2 in the major axis direction.

Here, the first side surface and the second side surface may further include corners formed by meeting each other, and the corners arranged to face each other in a long axis direction may be arranged parallel to the optical axis.

In addition, an absolute value of a tangential slope of the upper surface with respect to the curved surface may increase from an edge toward the optical axis.

In addition, among the light irradiated to the upper surface, the light irradiated toward the major axis direction at a predetermined angle θ with respect to the optical axis may be refracted toward the corner by the upper surface.

Alternatively, among the light irradiated to the upper surface, the light irradiated toward the long axis at a predetermined angle θ with respect to the optical axis is a region where the first and second exit surfaces meet by the upper surface. Can be refracted by

Here, the angle θ may be 52.5 degrees or less.

In addition, the height H1 in the minor axis direction of each of the first side surface and the second side surface may be 0.5 or more and less than 1 compared to the long axis direction height H2.

Here, an upper end of the first side surface and the second side surface may be formed to have a predetermined curvature.

In addition, the height (H1) in the short axis direction of the first side surface and the second side surface may be 2.8 to 3.0 times the height (H3) of the vertex (P2), which is a point of the upper surface disposed on the line of the optical axis (C). have.

Meanwhile, the length of the major axis may be 1.1 times or more of the length of the minor axis.

In addition, the lower surface may be formed in an oval shape.

The light diffusing lens according to the embodiment is formed to have a long axis and a short axis in a plane, and by designing a height on the long axis side higher than the height on the short axis side, it is possible to prevent leakage of light from the long axis side. Accordingly, light uniformity is improved at the edge of the long axis side, and asymmetric light distribution can be realized.

At this time, the upper surface is formed in a curved surface to reflect light irradiated at 52.5 degrees or less with respect to the optical axis.

The various and beneficial advantages and effects of the embodiments are not limited to the above description, and may be more easily understood in the course of describing specific embodiments of the embodiments.

1 is a diagram showing an arrangement and a light irradiation distribution of a plurality of lenses having isotropic surface irradiation characteristics,
2 is a perspective view showing a light diffusing lens according to the first embodiment,
3 is a plan view showing a light diffusing lens according to the first embodiment,
4 is a bottom view showing the light diffusing lens according to the first embodiment,
5 is a front view showing a light diffusing lens according to the first embodiment,
6 is a side view showing a light diffusing lens according to the first embodiment,
7 is a cross-sectional view in a short axis direction based on an upper surface of the light diffusing lens according to the first embodiment,
8 is a cross-sectional view taken along a major axis based on an upper surface of the light diffusing lens according to the first embodiment,
9 is a view showing light distribution according to the length of the long axis compared to the length of the short axis of the light diffusion lens according to the first embodiment,
10 is a diagram showing experimental results of a conventional light diffusing lens and a light diffusing lens according to the first embodiment,
11 is a diagram showing light diffusion in a major axis direction and a minor axis direction of the light diffusion lens according to the first embodiment;
12 is a view showing a light source for irradiating light to the incident surface of the light diffusing lens according to the embodiment,
13 is a perspective view showing a light diffusing lens according to a second embodiment,
14 is a plan view showing a light diffusing lens according to a second embodiment,
15 is a bottom view showing a light diffusing lens according to a second embodiment,
16 is a front view showing a light diffusing lens according to a second embodiment,
17 is a side view showing a light diffusing lens according to a second embodiment,
18 is a cross-sectional view in a minor axis direction based on an upper surface of the light diffusing lens according to the second embodiment;
19 is a cross-sectional view taken along a major axis with respect to an upper surface of the light diffusion lens according to the second embodiment.

The present invention is intended to illustrate and describe specific embodiments in the drawings, as various changes may be made and various embodiments may be provided. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers, such as second and first, may be used to describe various elements, but the elements are not limited by the terms. These terms are used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, a second component may be referred to as a first component, and similarly, a first component may be referred to as a second component. The term and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. Should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

In the description of the embodiment, in the case where one component is described as being formed in "on or under" of another component, the top (top) or bottom (bottom) (on or under) includes both of the two components being in direct contact with each other or one or more other components being indirectly formed between the two components. In addition, when expressed as'on or under', it may include not only an upward direction but also a downward direction based on one component.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, but the same reference numerals are assigned to the same or corresponding components regardless of the reference numerals, and redundant descriptions thereof will be omitted.

First Example

2 is a perspective view showing a light diffusing lens according to a first embodiment, FIG. 3 is a plan view showing a light diffusing lens according to the first embodiment, and FIG. 4 is a bottom view showing a light diffusing lens according to the first embodiment 5 is a front view showing a light diffusing lens according to a first embodiment, FIG. 6 is a side view showing a light diffusing lens according to the first embodiment, and FIG. 7 is a top view of the light diffusing lens according to the first embodiment. It is a cross-sectional view in the minor axis direction with respect to the plane, and FIG. 8 is a cross-sectional view in the major axis direction with respect to the upper surface of the light diffusion lens according to the first embodiment. Here, FIG. 7 is a cross-sectional view showing line A-A of FIG. 3, and FIG. 8 is a cross-sectional view showing line B-B of FIG. 3. In FIG. 2, the x direction is the minor axis direction of the emission surface, the y direction is the major axis direction of the emission surface, and the z direction indicates the optical axis direction.

Meanwhile, the optical axis C is a center of light irradiated from a light source, and may coincide with the center of the light diffusing lens 1.

The light diffusing lens 1 according to the first embodiment may be used in a liquid crystal display device. In this case, the liquid crystal display may include a substrate and a plurality of light sources mounted on the substrate. In addition, the light diffusion lens 1 may be disposed to cover the light source to implement asymmetric light distribution. Accordingly, in the liquid crystal display device in which the light diffusion lens 1 is disposed, an asymmetric light distribution is formed through the light diffusion lens 1 to prevent formation of a conventional dark area (see FIG. 1 ).

2 to 8, the light diffusing lens 1 according to the first embodiment includes a lower surface 100, an incident surface 200 to which light is incident, and light incident through the incident surface 200. It may include an exit surface 300 to be emitted.

Here, the light diffusing lens 1 may diffuse light incident through the incident surface 200 by using the aspherical incidence surface 200 and the exit surface 300. In addition, the exit surface 300 may include a pair of side surfaces 320 and 330 disposed to face each other with the upper surface 310.

In addition, the light diffusing lens 1 may include a pair of corners 340 formed by meeting side surfaces 320 and 330. In this case, the corners 340 may be disposed to face each other in the long axis direction.

The light diffusion lens 1 may be formed of a material of polycarbonate or polymethmethylacrylate. Here, the refractive index of the polycarbonate is 1.58, and the refractive index of the polymethmethyl acrylate is 1.49.

The lower surface 100 may be disposed on the lower side of the upper surface 310. In this case, the lower surface 100 may be disposed to be spaced apart from the upper surface 310 through the side surfaces 320 and 330. Here,'upper side' and'lower side' are relative expressions, and unless otherwise defined below, the direction from the lower surface 100 to the upper surface 310 is determined as the upper side (upper side), and on the contrary, the upper side ( The direction from 310) toward the lower surface 100 is determined as the lower side (downward).

The lower surface 100 may be formed in a convex shape or a planar shape toward the lower side. In this case, the lower surface 100 having a convex shape toward the lower side may be a curved surface having a predetermined curvature.

The lower surface 100 is formed as a curved surface convex in a downward direction, but is not limited thereto. For example, the lower surface 100 may have a plane formed from the edge to a certain length in the center direction, and the lower convex surface may be formed from the point where the plane ends toward the center. That is, the lower surface 100 may have a shape in which the curvature is 0 for a certain length from the edge to the center direction, but the curvature increases from the certain length to the center and then decreases again.

Compared with the lower surface composed of only the plane, in the case of the lower surface 100 having the lower convex surface, the light emitted from the lower side of the light emitted from the light source may be more totally reflected to the upper side.

Here, it is preferable that a plane disposed on the lower surface 100 so that the light is preferentially totally reflected by the lower convex surface is disposed outside the lower convex surface.

As shown in FIG. 4, the lower surface 100 may be formed in a shape of a rugby ball in which a circular incidence hole 210 is disposed in the center, but is not limited thereto. For example, the lower surface 100 may be formed in an elliptical shape having a long axis and a short axis.

The incidence surface 200 is a surface portion through which light emitted from a light source positioned at the incidence port 210 is incident into the light diffusion lens 1.

The incident surface 200 may be formed to be concave inward from the center of the lower surface 100. Accordingly, the entrance opening 210 may be formed in the center of the lower surface 100. In addition, a light source that irradiates light toward the incident surface 200 may be disposed at the entrance port 210.

An air layer may be disposed between the light source and the incident surface 200. Accordingly, the light emitted from the light source to the air layer may be further refracted at the incident surface 200 of the light diffusing lens 1 having a different refractive index.

2, 7 and 8, the incidence surface 200 includes a first region 220 formed in a circular shape in a plane and a second region 230 formed concave in the first region 220. Can include.

The first region 220 may be disposed below the second region 230. In addition, as the first region 220 is formed in a cylindrical shape, the entrance port 210 may also be formed in a circular shape. Accordingly, the entrance opening 210 may have a predetermined radius with respect to the optical axis C. In addition, the light source may be disposed in the center of the entrance port 210.

Light emitted from the light source to the side surfaces 320 and 330 may be incident on the first region 220.

The second region 230 may extend from an upper side of the first region 220. In this case, the second region 230 may be formed to be concave upward so that the vertex P1 is formed on the optical axis C. As shown in FIGS. 7 and 8, the second region 230 may include a curved surface. In addition, the curved surface may be formed to be convex toward the optical axis C to have a predetermined curvature, but is not limited thereto. For example, the curved surface may be formed in an oval or parabolic shape.

The second area 230 may be located above the light source. In this case, the absolute value of the tangent slope of the curved surface of the second region 230 may be gradually decreased from the top to the bottom of the curved surface.

Here, it is assumed that the incident surface 200 includes the first region 220 and the second region 230 having different shapes, but is not limited thereto. For example, the vertical cross section of the incident surface 200 may be formed in a hemispherical shape, a semi-elliptic shape, a half rugby ball shape, or a parabolic shape. Accordingly, the incident surface 200 may be formed as an aspherical surface.

Meanwhile, when viewed from the direction of the optical axis of the light source, the light diffusion lens 1 may be formed to have a major axis and a minor axis in a plane. In this case, the height H1 of each of the first side surface 320 and the second side surface 330 of the light diffusion lens 1 is smaller than the height H2 in the major axis direction. Here, the first side surface 320 and the second side surface 330 may be formed symmetrically with respect to the long axis.

2 to 4, when viewed from the optical axis C, the light diffusion lens 1 may be formed in a rugby hole shape on a plane.

As shown in FIG. 3, when viewed from the optical axis direction, the light diffusing lens 1 may include a short axis formed with a predetermined length Lx and a long axis formed with a predetermined length Ly. In detail, a short axis of the upper surface 310 of the emission surface 300 of the light diffusing lens 1 may be formed to have a predetermined length Lx, and the long axis may be formed with a predetermined length Ly. In this case, the length (Ly) of the major axis is greater than the length (Lx) of the minor axis. Accordingly, the light diffusion lens 1 can increase the amount of light diffusion in the long axis direction.

Here, the long axis and the short axis of the light diffusing lens 1 are arranged vertically in a plane, and at a virtual point where the long axis and the short axis meet, as shown in FIG. 3, an optical axis C is disposed. . Accordingly, when viewed from the optical axis C, the light diffusing lens 1 may be formed symmetrically with respect to the major axis and the minor axis.

The length of the long axis of the light diffusing lens 1 may be greater than or equal to 1.1 times the length of the short axis and less than or equal to 2.0 times. Here, the length (Ly) of the long axis of the light diffusion lens (1) may be referred to as the width of the light diffusion lens (1) in the direction of the long axis, and the length of the short axis (Lx) of the light diffusion lens (1) ) May be referred to as the width of the light diffusion lens 1 with respect to the short axis direction.

When the length of the long axis of the light diffusion lens 1 is less than 1.1 times the length of the short axis, it is difficult to remove the above-described dark area, and when it exceeds 2.0 times, the light uniformity and production efficiency are affected.

9 is a view showing light distribution according to the length of the long axis versus the length of the short axis of the light diffusion lens according to the first embodiment, and FIG. 9A shows the light distribution when the short axis length and the long axis length of the light diffusion lens are the same, Figure 9(b) shows the light distribution when the long axis length is less than 1.1 times the short axis length of the light diffusing lens, and Fig. 9(c) shows the light distribution when the long axis length is 1.1 times or more compared to the short axis length of the light diffusion lens. Show.

As shown in (a) of FIG. 9, when the short and long axis lengths of the light diffusion lens are the same, the dark area (see FIG. 1) cannot be removed.

As shown in (b) of FIG. 9, even if the length of the long axis compared to the short axis length of the light diffusion lens is less than 1.1 times, the dark area (see FIG. 1) cannot be removed.

As shown in (c) of FIG. 9, when the length of the long axis of the light diffusion lens 1 is 1.1 times or more than the length of the short axis, an asymmetric light distribution may be formed to remove the dark area.

10 is a view showing the experimental results of the conventional light diffusing lens and the light diffusing lens according to the first embodiment, FIG. 10A is a diagram showing the experimental results of the conventional light diffusing lens, and FIG. b) is a diagram showing an experiment result of the light diffusing lens according to the first embodiment.

Referring to FIG. 10, it can be seen that the light diffusion amount of the light diffusion lens 1 increases in the long axis direction compared to the conventional lens 2.

As shown in (b) of FIG. 10, the light diffusion lens 1 implements anisotropic light diffusion. Further, when comparing the area A1 of FIG. 10A and the area A2 of FIG. 10B, the light diffusion lens 1 is an area A2 (the edge in the major axis direction of the light diffusion lens 1). Even light is implemented.

The upper surface 310 of the emission surface 300 may be formed in a shape recessed from the edge toward the center. In this case, the upper surface 310 may have a convex curved surface protruding upward.

The upper surface 310 may reflect light refracted by the incident surface 200 to the side surfaces 320 and 330 and the corners 340. For example, among the light irradiated from the light source to the upper surface 310, the light irradiated toward the long axis direction at a predetermined angle θ with respect to the optical axis C is refracted toward the corner by the upper surface 310 Can be. Accordingly, the light diffusion lens 1 can prevent the occurrence of leakage light in the long axis direction. Here, the upper surface 310 may be referred to as a reflective surface.

Since the light diffusion lens 1 is made of a material having a higher density than air, light incident on the upper surface 310 with respect to the optical axis C at a predetermined angle θ can be totally reflected. Here, the angle θ is an angle formed by the optical axis C and the light irradiated from the light source, and may be an acute angle, as shown in FIG. 11. In addition, the angle θ is a virtual line connecting the upper edge with respect to the short axis direction of the side surfaces 320 and 330 and the center of the upper emission surface of the light source (optical axis vertex 11a) and the optical axis C It may be an angle to form.

In addition, the angle θ may be 52.5 degrees or less. If the angle θ exceeds 52.5 degrees and is incident on the upper surface 310 formed in a curved surface, light leakage may occur in the long axis direction.

FIG. 11 is a diagram showing light diffusion in a major axis direction and a minor axis direction of the light diffusion lens according to the first embodiment, and FIG. 11A is a leakage occurring in the minor axis direction of the light diffusion lens according to the first embodiment. It is a view showing light, and FIG. 11B is a view showing effective light from which leakage light is prevented in the long axis direction of the light diffusion lens according to the first embodiment.

As shown in (a) of FIG. 11, leakage light is generated in the short axis direction of the light diffusion lens 1. Here, the leakage light may mean light that is not irradiated toward the side surfaces 320 and 330. In particular, the leakage light may mean light irradiated upward from the side surfaces 320 and 330.

Accordingly, light deflection may occur in the short axis direction of the light diffusing lens 1 as shown in area A3 of FIG. 10B.

As shown in (b) of FIG. 11, since the length of the upper surface 310 in the long axis direction of the light diffusion lens 1 is longer than that of the minor axis direction and the height is higher than that in the minor axis direction, it is formed in the minor axis direction. The leaked light is converted into effective light.

Accordingly, light is uniformly distributed as in the area A2 of FIG. 10B.

Referring to FIG. 11, in the light diffusing lens 1, among the light irradiated to the upper surface 310, the leakage light increases toward the short axis direction of light irradiated at 52.5 degrees or less with respect to the optical axis C. . That is, for light irradiated to the upper surface 310 at 52.5 degrees or less with respect to the optical axis C, the light diffusion lens 1 may decrease the leakage light from the minor axis direction to the major axis direction in a plan view.

Therefore, the light diffusion lens 1 can prevent the occurrence of leakage light in the long axis direction by adjusting the length (Ly) and height (H2) in the long axis direction to form the upper surface 310 formed in a curved surface. have. In addition, the light diffusing lens 1 expands the coverage of light in the direction of the major axis, and may derive asymmetric light distribution by the expanded coverage.

The curved surface of the upper surface 310 may increase as the absolute value of the slope of the tangent line increases from the edge toward the optical axis C. In addition, since the curved surface of the light diffusing lens 1 has a length Ly in a major axis direction longer than a length Lx in the minor axis direction, the first side surface 320 and the second side surface of the light diffusing lens 1 The height H1 in the minor axis direction of each of the side surfaces 330 is smaller than the height H2 in the major axis direction. Here, the height H2 in the major axis direction may be the height of the edge 340. Further, the reference for the height may be the lower surface 100 or the lower edge of each of the first side surface 320 and the second side surface 330.

In this case, the height H1 in the minor axis direction of each of the first side surface 320 and the second side surface 330 may be 0.5 or more and less than 1 compared to the major axis direction height H2. That is, the height H1 in the minor axis direction of each of the first side surface 320 and the second side surface 330 may be formed within a range of 0.5*H2≦H1<1*H2.

When the height H1 in the minor axis direction is less than 0.5 times the height H2 in the major axis direction, leakage light may occur in the first side surface 320 and the second side surface 330, and the height H1 in the minor axis direction is When the height H2 in the long axis direction is the same, a light transmission phenomenon of light irradiated from the upper surface 310 to less than 52.5 degrees relative to the optical axis C may occur.

In addition, the curved surface of the upper surface 310 may be formed to have a predetermined curvature (1/R1). Referring to FIGS. 7 and 8, the curvature (1/R1) in the major axis direction and the minor axis direction The curvature (1/R1) may be the same. In this case, the center of the curvature 1/R1 may be disposed outside the light diffusion lens 1.

That is, the upper surface 310 is formed to be rotationally symmetrical with respect to the optical axis C, but may be formed in a longer shape in the long axis direction. Here, the curvature of the upper surface 310 may be referred to as a first curvature. Therefore, the upper surface 310 may be formed to have a narrower radius toward the optical axis C, and may be formed in a recessed shape.

The example is that the curved surface of the upper surface 310 is formed to have a predetermined curvature, but is not limited thereto. For example, the curved surface may be formed in a partial shape of a parabola or an ellipse.

The side surface disposed between the lower surface 100 and the upper surface 310 may include a first side surface 320 and a second side surface 330.

The first side surface 320 and the second side surface 330 may be disposed to face each other with the optical axis C interposed therebetween. In this case, the first side surface 320 and the second side surface 330 may be formed parallel to the optical axis C.

In this case, the height H1 in the minor axis direction of each of the first side surface 320 and the second side surface 330 is smaller than the height H2 in the major axis direction.

Accordingly, the first side portion 321 of the first side surface 320 may be disposed in the short axis direction, and the second side portion 331 may be disposed on the second side side surface 330. Accordingly, the height H1 of the first side surface 320 and the second side surface 330 in the short axis direction may be the height of the first side portion 321 and the second side portion 331.

In addition, the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 is the height of the vertex P2, which is one point of the upper surface 310 disposed on the line of the optical axis C ( Greater than H3). In this case, the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 is the height of the vertex P2, which is a point of the upper surface 310 disposed on the optical axis C line (H3 ) Can be 2.8~3.0 times. Preferably, the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 is the height of the vertex P2, which is a point of the upper surface 310 disposed on the optical axis C. ) Can be 2.9 times.

Since the height H3 of the vertex P2, which is one point of the upper surface 310, is disposed on the line of the optical axis C, it can be formed at a constant height regardless of the major axis direction and the minor axis direction.

In addition, as the height H3 of the vertex P2 is adjusted, an increase in the inclination of the tangent line of the upper surface 310 formed as a curved surface may be adjusted. Accordingly, the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 may also be adjusted in consideration of the height H3 of the vertex P2.

Accordingly, the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 in consideration of total reflection and light transmission by the upper surface 310 is set on the optical axis (C). It may be formed to be 2.8 to 3.0 times the height H3 of the vertex P2, which is one point of the surface 310.

On the other hand, as the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 is formed smaller than the height H2 of the edge 340, as shown in FIG. 6, Upper sides of the first side surface 320 and the second side surface 330 may be formed to have a predetermined curvature (1/R2). Here, the curvature 1/R2 may be referred to as a second curvature.

3 and 4, the first side surface 320 and the second side surface 330 may be formed to be convex outward on a plane. Here, the term "outside" means a direction opposite to the direction toward the optical axis (C). Accordingly, the first side surface 320 and the second side surface 330 may include a curved surface that is convex outward. Further, the curved surfaces of the first side surface 320 and the second side surface 330 may be formed to have a predetermined curvature.

In addition, the centers of the curvature of each of the first side surface 320 and the second side surface 330 may be disposed to be spaced apart from the optical axis C in a plane. At this time, the center of the curvature of the first side surface 320 may be formed on the side of the second side surface 330 and the center of the curvature of the second side surface 330 may be formed on the side of the first side surface 320. Therefore, the light diffusion lens 1 may include a pair of corners 340 formed by meeting the first side surface 320 and the second side surface 330.

Referring to FIG. 12, a light source 10 that irradiates light toward the incident surface 200 may include an upper emission surface 11 and four side emission surfaces 12. Accordingly, the light source 10 can embody five-sided light emission. In this case, the lower surface of the light source 10 may be disposed to be in contact with the upper surface of the substrate 20.

Light irradiated from the upper light emitting surface 11 of the light source 10 is irradiated in the optical axis direction (z direction), and the light irradiated from the side light emitting surface 12 is irradiated in the radial direction of the light diffusing lens 1. I can.

In addition, an optical axis peak 11a may be formed at the center of the upper light emitting surface 11. At this time, the optical axis apex 11a may be disposed on the line of the optical axis C.

Here, an LED may be used as the light source 10. In addition, a yellow phosphor may be applied to the LED.

In summary, the light diffusion lens 1 includes the long axis and the short axis in a plane, and increases the length of the upper surface 310 formed as a curved surface in the long axis direction compared to the short axis direction, and at the same time, the side surfaces 320 and 330 ) May be formed to be larger than the height H1 in the minor axis direction. Accordingly, the light diffusing lens 1 uses the upper surface 310 formed as a curved surface to totally reflect the light incident therein toward the edge 340.

Accordingly, the light diffusing lens 1 may increase light diffusivity in the long axis direction by the upper surface 310 whose length is increased in the long axis direction. Accordingly, the light diffusion lens 1 may prevent or minimize the existence of leakage light that may occur in the direction of the long axis.

Second Example

13 is a perspective view showing a light diffusing lens according to a second embodiment, FIG. 14 is a plan view showing a light diffusing lens according to a second embodiment, and FIG. 15 is a bottom view showing a light diffusing lens according to the second embodiment And FIG. 16 is a front view showing a light diffusing lens according to a second embodiment, FIG. 17 is a side view showing a light diffusing lens according to the second embodiment, and FIG. 18 is a top view of the light diffusing lens according to the second embodiment. It is a cross-sectional view in the minor axis direction with respect to the plane, and FIG. 19 is a cross-sectional view in the major axis direction with respect to the upper surface of the light diffusion lens according to the second embodiment. Here, FIG. 18 is a cross-sectional view taken along line A1-A1 in FIG. 14, and FIG. 19 is a cross-sectional view taken along line B1-B1 in FIG. 14. In FIG. 13, the x direction is the minor axis direction of the emission surface, the y direction is the major axis direction of the emission surface, and the z direction is the optical axis direction.

13 to 19, the light diffusing lens 1a according to the second embodiment includes a lower surface 100a, an incident surface 200 to which light is incident, and light incident through the incident surface 200. It may include an exit surface (300a) to be emitted. Here, in that the upper surface 310a of the lower surface 100a and the exit surface 300a is formed in an elliptical shape when viewed from the optical axis direction, the difference in shape from the light diffusion lens 1 according to the first embodiment Have.

The light diffusing lens 1a may diffuse light incident through the incident surface 200 using the aspheric incidence surface 200 and the exit surface 300a. In addition, the exit surface 300a may include an upper surface 310a and one side surface 350. Here, the light diffusing lens 1 according to the first embodiment includes a pair of corners 340 formed by meeting the side surfaces 320 and 330, and thus is formed in the shape of a rugby ball when viewed from the optical axis direction. , In the case of the light diffusing lens 1a according to the second embodiment, the light diffusing lens 1 according to the first embodiment rounds a pair of corners 340 formed by meeting the side surfaces 320 and 330 It is formed in an oval shape.

The lower surface 100a may be disposed on the lower side of the upper surface 310a. In this case, the lower surface 100a through the side surface 350 may be disposed to be spaced apart from the upper surface 310a.

As shown in FIG. 15, the lower surface 100a may be formed in an elliptical shape in which a circular entrance port 210 is disposed in the center.

Meanwhile, when viewed from the direction of the optical axis of the light source, the light diffusion lens 1a may be formed to have a long axis and a short axis in a plane. At this time, the height H1 in the minor axis direction of the side surface 350 of the light diffusion lens 1a is smaller than the height H2 in the major axis direction.

As shown in FIG. 14, when viewed from the optical axis direction, the light diffusing lens 1a may include a short axis formed with a predetermined length Lx and a long axis formed with a predetermined length Ly. In detail, the short axis of the upper surface 310a of the emission surface 300a of the light diffusion lens 1a may be formed to have a predetermined length Lx, and the long axis may be formed with a predetermined length Ly. In this case, the length (Ly) of the major axis is greater than the length (Lx) of the minor axis. Accordingly, the light diffusion lens 1a can increase the amount of light diffusion in the long axis direction.

Here, the long axis and the short axis of the light diffusing lens 1a are arranged vertically in a plane, and an optical axis C is disposed as shown in FIG. 14 at a virtual point where the long axis and the short axis meet. .

The upper surface 310a of the emission surface 300a may be formed in a shape recessed from the edge toward the center. In this case, the upper surface 310a may have a convex curved surface protruding upward. As shown in Fig. 5, the light diffusion lens 1 according to the first embodiment may have a vertex formed by the corner 340, but as shown in Fig. 16, the light diffusion according to the second embodiment In the lens 1a, the vertex may be deleted by a rounding process.

In this case, the upper surface 310a may reflect light refracted by the incident surface 200 to the side surface 350.

Therefore, the light diffusion lens 1a can prevent the occurrence of leakage light in the long axis direction by adjusting the length Ly and height H2 in the long axis direction to form the upper surface 310a formed in a curved surface. have. Accordingly, the light diffusing lens 1a expands the coverage of light in the long axis direction, and asymmetric light distribution may be derived by the expanded coverage.

The side surface 350 disposed between the lower surface 100a and the upper surface 310a may be formed symmetrically with respect to the major axis and the minor axis. In this case, the side surface 350 may be formed parallel to the optical axis C.

Although the above has been described with reference to the embodiments of the present invention, those skilled in the art can variously modify and modify the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can change it. And, the differences related to such modifications and changes should be construed as being included in the scope of the present invention defined in the appended claims.

1, 1a: light diffusion lens
100, 100a: lower side
200: entrance surface 210: entrance opening
300, 300a: exit surface
310, 310a: top surface 320, 330, 350: side surface
321: first side 322: second side
C: optical axis

Claims (12)

A lower surface on which the short axis and the major axis are formed;
An incidence surface formed concave inward from a region (incidence port) of the lower surface; And
Including an exit surface through which light incident through the incident surface is emitted,
The exit plane is,
A curved upper surface that is recessed from the outer periphery in the optical axis direction and protrudes upward; And
And a side surface vertically connecting the outer circumference of the upper surface and the outer circumference of the lower surface,
The incident surface,
A first surface having a cylindrical shape in cross section and forming a side surface of the cylindrical shape; And
A light diffusion lens including a second surface having a curved shape extending upward from the first surface and concave upward so that a vertex is formed on the optical axis.
The method of claim 1, wherein the lower surface has an outer circumferential shape, wherein a first end and a second end forming the long axis are sharply formed, and from the first end to the second end and from the second end to the second end. A light diffusing lens in the shape of a rugby ball that forms a curved surface having a predetermined curvature up to one end.
The light diffusing lens of claim 1, wherein the lower surface has an elliptical shape.
delete delete The light diffusing lens according to claim 1, wherein an absolute value of a slope of a tangent line of the curved surface of the upper surface increases from an outer circumference to an optical axis.
delete The method of claim 1,
The height of the side surface in the minor axis direction is lower than the height in the major axis direction.
The light diffusing lens of claim 8, wherein the height in the minor axis direction is 0.5 or more and less than 1 compared to the height in the major axis direction.
The method of claim 9,
An upper portion of the side surface is a light diffusion lens having a predetermined curvature.
The method of claim 8,
The height in the short axis direction is 2.8 to 3.0 times the lowest height of the upper surface.
The method of claim 1,
The length of the major axis is at least 1.1 times the length of the minor axis.

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