WO2020116830A1

WO2020116830A1 - Light diffusion lens

Info

Publication number: WO2020116830A1
Application number: PCT/KR2019/015950
Authority: WO
Inventors: 이강현; 기호경
Original assignee: 주식회사 에이치엘옵틱스
Priority date: 2018-12-06
Filing date: 2019-11-20
Publication date: 2020-06-11
Also published as: KR20200069156A; KR102213297B1

Abstract

A light diffusion lens is disclosed. A light diffusion lens according to one embodiment of the present invention comprises: a lower surface having a short axis and a long axis; a light incident surface recessed inward from a partial region (entrance aperture) of the lower surface; and a light emitting surface through which light that is incident through the light incident surface is emitted, wherein the light emitting surface includes a curved upper surface, and a lateral surface for vertically connecting the outer periphery of the upper surface and the outer periphery of the lower surface.

Description

Light diffusing lens

The present invention relates to a light diffusing lens.

Focusing on the rapidly developing semiconductor technology, the demand for the flat panel display device has been explosively increased due to its small size and light weight.

Among these flat panel display devices, a liquid crystal display (LCD), which has recently been spotlighted, has advantages such as miniaturization, light weight, and low power consumption, so that it can overcome the disadvantages of the conventional cathode ray tube (CRT). As an alternative means, it has been gradually attracting attention, and it is currently installed and used in almost all information processing devices requiring display devices.

Since the liquid crystal display panel in the liquid crystal display device is a light-receiving element that does not emit light by itself, 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 optical sheets.

In addition, the lamp has a relatively small amount of heat, generates white light close to natural light, and uses a long-life cold cathode ray tube type lamp or a light-emitting diode (hereinafter referred to as'LED') that has good color reproducibility and consumes low power. Anticorrosion lamps are used.

In the past, a cold cathode ray tube type lamp was used, but since the LED type lamp has the advantage of good color reproducibility and low power consumption, LED type lamp products have begun to be used.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the arrangement|positioning of several lenses which have an isotropic surface irradiation characteristic, and light irradiation distribution.

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

As illustrated in FIG. 1, there is a problem in that a mura in the form of a dark portion occurs in a diagonal direction with respect to one lens 2. For example, when an LED is used as a light source, the light emitted by the LED tends to concentrate in the front direction of the LED due to its strong straightness. Accordingly, there is an increasing demand for a technique for effectively and uniformly diffusing the light of a plurality of LEDs.

Therefore, the lens technology that can improve the uniformity of light by designing the incident surface where light enters and the emitting surface through which light is emitted to implement an anisotropic surface irradiation, and minimizing the dark portion generated in the diagonal direction of the lens based on this, The demand for the situation is also increasing.

The technical problem to be solved by the present invention is to provide a light diffusing lens having an incident surface on which light is incident and an emitting surface on which light is emitted so as to minimize dark portions generated in a diagonal direction of a plurality of light diffusion lenses.

Another technical problem to be solved by the present invention is to provide a light diffusing lens that is formed to have a long axis and a short axis on a plane, and designs a height of the long axis to be higher than the height of the short axis to prevent leakage of light from the long axis.

In order to solve the above technical problem, the light diffusing lens according to an embodiment of the present invention includes a lower surface on which a short axis and a long axis are formed; An incidence surface concavely formed inward from one region (entrance entrance) of the lower surface; And an emission surface through which light incident through the incident surface is emitted, wherein the emission surface includes: a curved upper surface; And a side surface vertically connecting the outer circumference of the upper surface and the outer circumference of the lower surface.

In one embodiment of the present invention, the lower surface, the outer circumferential shape may be a rugby ball shape.

In one embodiment of the present invention, the lower surface, the outer circumferential shape may be an elliptical shape.

In one embodiment of the present invention, the incidence surface includes: a first surface having a cylindrical shape in cross section; And a second surface extending from the first surface to the upper side and concave to the upper side.

In one embodiment of the present invention, the second surface may be convex toward the optical axis.

In one embodiment of the present invention, the upper surface may be recessed in the optical axis direction from the outer periphery, and may be a curved surface projecting toward the upper side.

In one embodiment of the present invention, the absolute value of the inclination of the tangent of the curved surface of the upper surface may be increased from the outer circumference toward the optical axis.

In one embodiment of the present invention, the upper surface may be a circular shape forming a predetermined curvature.

In one embodiment of the present invention, the height in the minor axis direction of the side surface may be lower than the height in the major axis direction.

In one embodiment of the present invention, the height in the minor axis direction is 0.5 or more and less than 1 in comparison to the height in the major axis direction.

In one embodiment of the present invention, the upper portion of the side surface may achieve a predetermined curvature.

In one embodiment of the present invention, the height in the minor axis direction may be 2.8 to 3.0 times the lowest height of the upper surface.

In one embodiment of the present invention, the length of the long axis may be 1.1 times or more of the length of the short axis.

The present invention as described above is formed to have a long axis and a short axis on a plane, and the height of the long axis is designed to be higher than the height of the short axis, so that leakage light can be prevented from occurring on the long axis. Accordingly, light uniformity is improved at the edge of the long axis side, and asymmetric light distribution is realized.

2 is a perspective view of a light diffusing lens of the first embodiment of the present invention.

3 is a plan view of a light diffusing lens of the first embodiment of the present invention.

4 is a bottom view of the light diffusing lens of the first embodiment of the present invention.

5 is a front view of the light diffusing lens of the first embodiment of the present invention.

6 is a side view of a light diffusing lens of the first embodiment of the present invention.

7 is a cross-sectional view of a minor axis direction based on the upper surface of the light diffusing lens of the first embodiment of the present invention.

8 is a cross-sectional view of a long axis direction based on an upper surface of the light diffusing lens of the first embodiment of the present invention.

9 is a view showing light distribution according to a long axis length versus a short axis length of the light diffusion lens of the first embodiment of the present invention.

10 is an exemplary view showing the performance results of the light diffusing lens of the first embodiment of the present invention.

11 is a view showing light diffusion in the long axis direction and the short axis direction of the light diffusion lens of the first embodiment of the present invention.

12 is a view showing a light source applied to the light diffusion lens of the present invention.

13 is a perspective view of a light diffusing lens of the second embodiment of the present invention.

14 is a plan view of a light diffusing lens according to a second embodiment of the present invention.

15 is a bottom view of the light diffusing lens of the second embodiment of the present invention.

16 is a front view of a light diffusing lens of the second embodiment of the present invention.

17 is a side view of a light diffusing lens of the second embodiment of the present invention.

18 is a cross-sectional view of a minor axis direction based on the upper surface of the light diffusing lens of the second embodiment of the present invention.

19 is a cross-sectional view of the long axis direction based on the upper surface of the light diffusing lens of the second embodiment of the present invention.

In order to fully understand the configuration and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and can be implemented in various forms and various changes can be made. However, the description of the present embodiment is provided to complete the disclosure of the present invention, and to fully inform the scope of the invention to those skilled in the art to which the present invention pertains. In the accompanying drawings, the components are enlarged and enlarged than actual sizes for convenience of description, and the ratio of each component may be exaggerated or reduced.

Terms such as'first' and'second' can be used to describe various components, but the components should not be limited by the above terms. The above term may be used only for the purpose of distinguishing one component from other components. For example, without departing from the scope of the present invention, the'first component' may be referred to as a'second component', and similarly the'second component' may also be referred to as a'first component'. Can be. In addition, a singular expression includes a plural expression unless the context clearly expresses otherwise. The terms used in the embodiments of the present invention may be interpreted as meanings commonly known to those skilled in the art unless otherwise defined.

Hereinafter, a light diffusing lens according to an embodiment of the present invention will be described with reference to the drawings.

[제1실시예][First Embodiment]

Fig. 2 is a perspective view of the light diffusing lens of the first embodiment of the present invention, Fig. 3 is a plan view of the light diffusing lens of the first embodiment of the present invention, and Fig. 4 is a bottom view of the light diffusing lens of the first embodiment of the present invention 5 is a front view of the light diffusing lens of the first embodiment of the present invention, FIG. 6 is a side view of the light diffusing lens of the first embodiment of the present invention, and FIG. 7 is a light diffusing lens of the first embodiment of the present invention. 8 is a cross-sectional view of the minor axis direction with respect to the upper surface, and FIG. 8 is a cross-sectional view of the long axis direction with respect to the upper surface of the light diffusing lens of the first embodiment of the present invention.

Here, FIG. 7 is a cross-sectional view showing the A-A line in FIG. 3, and FIG. 8 is a cross-sectional view showing the B-B line in FIG. 3. In addition, in FIG. 2, the x-direction is the shortening direction of the exit surface, the y-direction is the long axis direction of the exit surface, and the z-direction indicates the optical axis direction. The optical axis C is the center of light irradiated from the light source, and may coincide with the center of the light diffusion lens 1.

The light diffusing lens 1 of one embodiment of the present invention can be used in a liquid crystal display device. At this time, 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, the liquid crystal display device in which the light diffusion lens 1 is disposed can form an asymmetrical light distribution through the light diffusion lens 1 to prevent the formation of a conventional dark region (see FIG. 1 ).

2 to 8, the light diffusing lens 1 of the first embodiment of the present invention has a lower surface 100, an incident surface 200 through which light is incident, and light incident through the incident surface 200 It may include an exit surface 300 that is 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 the upper surface 310 and each other.

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

The light diffusing lens 1 may be formed using a material of polycarbonate or polymethacrylate. Here, the refractive index of the polycarbonate is 1.58, and the refractive index of the polymethmethylacrylate is 1.49.

The lower surface 100 may be disposed on the lower side of the upper surface 310. At this time, the lower surface 100 through the side surfaces 320 and 330 may be spaced apart from the upper surface 310. 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 defined as the upper side (upper), and vice versa. The direction from 310 to the lower surface 100 will be determined as the lower side (downward).

The lower surface 100 may be formed in a convex or planar shape toward the lower side. At this time, 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 having a convex shape in the downward direction as an example, but is not limited thereto. For example, the lower surface 100 may be formed with a plane from the edge to a certain length in the center direction, and a lower convex surface may be formed from the point where the plane ends to the center side. That is, the lower surface 100 has a curvature of 0 for a certain length from the edge to the center direction, but may be a shape in which the curvature increases from a certain length or more to the center and then decreases again.

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

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

As illustrated in FIG. 4, the lower surface 100 may be formed in a rugby ball shape in which a circular inlet 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 incident surface 200 is a portion of the surface from which light emitted from the light source located at the entrance 210 is incident into the light diffusing lens 1.

The incident surface 200 may be formed concave from the center of the lower surface 100 to the inside. Accordingly, the entrance port 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. Therefore, in the case of light emitted from the light source to the air layer, the refractive index may be further refracted on the incident surface 200 of the light diffusing lens 1.

2, 7 and 8, the incident surface 200 includes a first region 220 formed in a circular shape on a plane and a second region 230 concavely formed inward from the first region 220. can do.

The first region 220 may be disposed under the second region 230. In addition, as the first region 220 is formed in a cylindrical shape, the entrance sphere 210 may also be formed in a circular shape. Accordingly, the entrance sphere 210 may have a predetermined radius based on the optical axis C. In addition, a light source may be disposed at 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 the upper side of the first region 220. At this time, the second region 230 may be concave to the upper side so that the vertex P1 is formed on the optical axis C. As illustrated in FIGS. 7 and 8, the second region 230 may include a curved surface. Further, the curved surface may 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 ellipse or parabolic shape.

The second region 230 may be located on the upper side of the light source. At this time, the absolute value of the tangential slope of the curved surface of the second region 230 may gradually decrease from the top to the bottom of the curved surface.

Here, although the incident surface 200 includes the first region 220 and the second region 230 having different shapes, for example, the present invention is not limited thereto. For example, the vertical cross section of the incidence surface 200 may be formed in a hemispherical shape, a semi-elliptical shape, a rugby ball shape, or a parabolic shape. Accordingly, the incident surface 200 may be formed as an aspherical surface.

On the other hand, when viewed in the direction of the optical axis of the light source, the light diffusing lens 1 may be formed to have a long axis and a short axis on a plane. At this time, 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 of the long 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 diffusing lens 1 may be formed in a planar rugby ball shape.

3, when viewed in the optical axis direction, the light diffusion lens 1 may include a short axis formed of a predetermined length Lx and a long axis formed of a predetermined length Ly. In detail, a short axis of the upper surface 310 of the exit surface 300 of the light diffusion lens 1 may be formed with a predetermined length Lx, and a long axis may be formed with a predetermined length Ly. At this time, the length of the long axis (Ly) is greater than the length of the short axis (Lx). Therefore, 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 vertically arranged in a plane, and at an imaginary point where the long axis and the short axis meet, as shown in FIG. 3, the optical axis C is arranged. Accordingly, when viewed from the optical axis C, the light diffusion lens 1 can be formed symmetrically with respect to the long and short axes.

The length of the long axis of the light diffusion lens 1 may be 1.1 times or more and 2.0 times or less of the length of the minor axis. 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 with respect to the long axis direction, and the length (Lx) of the short axis of the light diffusion lens 1 is in the short axis direction. It can be referred to as the width of the light diffusion lens (1).

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

9 is a view showing the light distribution according to the long axis length compared to the short axis length of the light diffusion lens of the first embodiment of the present invention, Figure 9 (a) shows the light distribution when the short axis length and the long axis length of the light diffusion lens is the same , FIG. 9(b) shows light distribution when the major axis length of the light diffusion lens is less than 1.1 times, and FIG. 9(c) shows light distribution when the major axis length of the light diffusion lens is 1.1 times or more. Indicates.

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

As shown in FIG. 9(b), even when the short axis length and the long axis length of the light diffusion lens are less than 1.1 times, the dark region (see FIG. 1) cannot be removed.

As shown in FIG. 9C, when the length of the long axis of the light diffusion lens 1 is 1.1 times or more of the length of the short axis, an asymmetrical light distribution may be formed to remove the dark region.

10 is an exemplary view showing the performance results of the light diffusing lens of the first embodiment of the present invention, FIG. 10 (a) is a view showing the experimental results of a conventional light diffusing lens, Figure 10 (b) is a A diagram showing the experimental results 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 is increased in the long axis direction compared to the conventional lens 2.

As shown in FIG. 10B, the light diffusing lens 1 of one embodiment of the present invention implements anisotropic light diffusion. Furthermore, when comparing the area A1 of FIG. 10A and the area A2 of FIG. 10B, the light diffusion lens 1 is equal in the area A2 (the edge of the light diffusion lens 1 in the long axis direction). It can be seen that one light is implemented.

On the other hand, the top surface 310 of the exit surface 300 may be formed in a shape recessed in the center direction from the edge. At this time, the upper surface 310 may be a convex curved surface projecting toward the upper side.

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, light irradiated toward the long axis at a predetermined angle θ based on the optical axis C may be refracted to the corner by the upper surface 310. Accordingly, the light diffusion lens 1 can prevent the generation 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 at a predetermined angle θ based on the optical axis C 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. And, the angle θ is the angle formed by the virtual line connecting the upper edge with respect to the minor axis direction of the side surfaces 320 and 330 and the center (optical axis vertex 11a) of the light source and the optical axis C. Can be.

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

11 is a view showing light diffusion in the long axis direction and the short axis direction of the light diffusion lens of the first embodiment of the present invention, and FIG. 11(a) is generated in the short direction of the light diffusion lens according to the first embodiment FIG. 11B is a view showing effective light in 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 minor axis direction of the light diffusion lens 1. Here, the leakage light may mean light that is not irradiated to the side surfaces 320 and 330. In particular, leakage light may mean light irradiated upward from the side surfaces 320 and 330.

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

11(b), the length of the upper surface 310 in the long axis direction of the light diffusing lens 1 of the first embodiment of the present invention is longer than that of the short axis direction, and the height is higher than that of the short axis direction. Since it is high, leakage light formed in the short axis direction can be converted into effective light. Accordingly, light may be uniformly distributed as in the area A2 of FIG. 10B.

Referring to FIG. 11, the light diffusing lens 1 of the light irradiated below 52.5 degrees based on the optical axis C among the light irradiated on the upper surface 310 increases the leakage light toward the short axis direction. That is, with respect to light irradiated to the upper surface 310 below 52.5 degrees based on the optical axis C, the light diffusion lens 1 may reduce leakage light as it goes from the short axis direction to the long axis direction in a planar view.

Accordingly, the light diffusing lens 1 of the first embodiment of the present invention forms the upper surface 310 formed as a curved surface by adjusting the length Ly and height H2 in the long axis direction, thereby generating leakage light in the long axis direction. Can be prevented. In addition, the light diffusion lens 1 enlarges the coverage of light with respect to the long axis direction, and can derive an 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 diffusion lens 1 has a length Ly in the long axis direction longer than a length Lx in the short axis direction, the first side surface 320 and the second side surface of the light diffusion lens 1 ( 330) Each short axis height H1 is smaller than the long axis direction height H2. Here, the height H2 in the long axis direction may be the height of the edge 340. In addition, the reference for the height may be the lower edge of each of the lower surface 100 or the first side surface 320 and the second side surface 330.

At this time, the height of the short axis direction H1 of each of the first side surface 320 and the second side surface 330 is 0.5 or more and less than 1, compared to the height of the long axis H2. That is, the height H1 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 <H2.

When the height in the short axis direction H1 is less than 0.5 times the height in the long axis direction H2, leakage light may be generated in the first side surface 320 and the second side surface 330, and the short axis direction height H1 is in the long axis direction When the height H2 is the same, a light transmission phenomenon may occur for light irradiated below 52.5 degrees based on the optical axis C on the upper surface 310.

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, curvature (1/R1) in the long axis direction and curvature (1) in the short axis direction /R1) may be the same. At this time, 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 and a recessed shape toward the optical axis C.

The example 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 part 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. At this time, the first side surface 320 and the second side surface 330 may be formed parallel to the optical axis C.

At this time, the height H1 of each of the first side surface 320 and the second side surface 330 is smaller than the height H2 of the long axis direction.

Accordingly, the first side portion 321 of the first side surface 320 may be disposed in the minor axis direction, and the second side portion 331 may be disposed on the second side surface 330. Accordingly, the height H1 in the short axis direction of the first side surface 320 and the second side surface 330 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 H3 of the vertex P2 which is one point of the upper surface 310 disposed on the optical axis C line. Greater than At this time, the height H1 of the first side surface 320 and the second side surface 330 in the short axis direction H1 is the height H3 of the vertex P2 which is one point of the upper surface 310 disposed on the optical axis C line. It can be 2.8 to 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 H3 of the vertex P2 which is a point of the upper surface 310 disposed on the optical axis C line. It 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 optical axis C line, it can be formed at a constant height regardless of the long axis direction and the short axis direction.

In addition, as the height H3 of the vertex P2 is adjusted, an increase in the slope with respect to the tangent 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, in consideration of total reflection and light transmission by the upper surface 310, the upper surface disposed on the optical axis C line is the height H1 of the short axis direction of the first side surface 320 and the second side surface 330. It can be formed at 2.8 to 3.0 times the height (H3) of the vertex (P2), which is one point of (310).

On the other hand, as shown in FIG. 6, as the height H1 in the minor axis direction of the first side surface 320 and the second side surface 330 is formed smaller than the height H2 of the corner 340, as shown in FIG. The 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 in a plane. Here, the outer side means the opposite direction of the direction toward the optical axis C. Accordingly, the first side surface 320 and the second side surface 330 may include an outwardly convex curved surface. In addition, the curved surfaces of the first side surface 320 and the second side surface 330 may be formed to have a predetermined curvature.

And, the center of curvature of each of the first side surface 320 and the second side surface 330 may be arranged to be spaced apart from the optical axis C on the plane. At this time, the center of curvature of the first side surface 320 may be formed on the second side surface 330 side, and the center of curvature of the second side surface 330 may be formed on the first side surface 320 side. 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, the light source 10 irradiating light toward the incident surface 200 may include an upper light emitting surface 11 and four side light emitting surfaces 12. Accordingly, the light source 10 may implement five-sided light emission. At this time, the lower surface of the light source 10 may be disposed to contact 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 light irradiated from the side light emitting surface 12 can be irradiated in the radial direction of the light diffusing lens 1. have.

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

Here, the light source 10 may include an LED. In addition, a yellow (Yellow) phosphor may be applied to the LED.

Taken together, the light diffusion lens 1 includes a long axis and a short axis on 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 long axis direction of the side surfaces 320 and 330. The height H2 can be formed larger than the height H1 in the minor axis direction. Accordingly, the light diffusion lens 1 uses the upper surface 310 formed as a curved surface to totally reflect the light incident therein to the edge 340 side.

Accordingly, the light diffusion 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 can prevent or minimize the presence of leakage light that may occur on the long axis direction side.

[제2실시예][Second Embodiment]

13 is a perspective view of the light diffusing lens of the second embodiment of the present invention, FIG. 14 is a plan view of the light diffusing lens of the second embodiment of the present invention, and FIG. 15 is a bottom view of the light diffusing lens of the second embodiment of the present invention 16 is a front view of the light diffusing lens of the second embodiment of the present invention, FIG. 17 is a side view of the light diffusing lens of the second embodiment of the present invention, and FIG. 18 is a light diffusing lens of the second embodiment of the present invention 19 is a cross-sectional view of the minor axis direction with respect to the upper surface, and FIG. 19 is a cross-sectional view of the long axis direction with respect to the upper surface of the light diffusing lens of the second embodiment of the present invention. Here, FIG. 18 is a cross-sectional view showing line A1-A1 in FIG. 14, and FIG. 19 is a cross-sectional view showing line B1-B1 in FIG. In Fig. 13, the x-direction is the minor axis direction of the exit surface, the y-direction is the major axis direction of the exit surface, and the z-direction indicates the optical axis direction.

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

The light diffusing lens 1a may diffuse light incident through the incidence surface 200 using the aspherical 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 the side surfaces 320 and 330 meeting, and is formed in a rugby ball shape when viewed in 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 is processed by rounding a pair of corners 340 where the side surfaces 320 and 330 meet. It may be formed in an oval shape.

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

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

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

As shown in FIG. 14, when viewed in the optical axis direction, the light diffusion lens 1a may include a short axis formed of a predetermined length Lx and a long axis formed of a predetermined length Ly. In detail, a short axis of the upper surface 310a among the exit surfaces 300a of the light diffusion lens 1a may be formed with a predetermined length Lx, and a long axis may be formed with a predetermined length Ly. At this time, the length of the long axis (Ly) is greater than the length of the short axis (Lx). Therefore, 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 vertically arranged in a plane, and at an imaginary point where the long axis and the short axis meet, as shown in FIG. 14, the optical axis C may be arranged.

The top surface 310a of the exit surface 300a may be formed in a shape recessed from the edge toward the center. At this time, the upper surface 310a may be a convex curved surface projecting toward the upper side. As shown in FIG. 5, the light diffusing lens 1 according to the first embodiment may have a vertex formed by an edge 340, but as shown in FIG. 16, light diffusing according to the second embodiment The vertex of the lens 1a may be deleted by a rounding process.

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

Therefore, the light diffusing lens 1a forms the upper surface 310a formed as a curved surface by adjusting the length Ly and the height H2 in the long axis direction, thereby preventing generation of leakage light in the long axis direction. Accordingly, the light diffusion lens 1a enlarges the coverage of light with respect to the long axis direction, and asymmetric light distribution can be derived by the expanded coverage.

The side surface 350 disposed between the lower surface 100a and the upper surface 310a may be symmetrically formed based on a long axis and a short axis. At this time, the side surface 350 may be formed parallel to the optical axis (C).

Although described above with reference to embodiments of the present invention, those skilled in the art can variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that you can change it. And, it should be interpreted that the differences related to the modifications and changes are included in the scope of the present invention defined in the appended claims.

Claims

A lower surface on which a short axis and a long axis are formed;

An incidence surface concavely formed inward from one region (entrance entrance) of the lower surface; And

And an emission surface through which light incident through the incident surface is emitted,

The exit surface,

A curved upper surface; And

And a side surface vertically connecting the outer circumference of the upper surface and the outer circumference of the lower surface.
The method of claim 1, wherein the lower surface,

A light diffusing lens having an outer circumferential shape of a rugby ball.
The method of claim 1, wherein the lower surface,

A light diffusing lens having an outer circumferential shape.
The method of claim 1, wherein the incident surface,

A first surface having a cylindrical shape in cross section; And

A light diffusing lens comprising a second surface extending upwardly from the first surface to be concave toward the upper side.
The light diffusion lens of claim 4, wherein the second surface is convex toward the optical axis.
The method of claim 1, wherein the upper surface,

A light diffusion lens that is recessed in the direction of the optical axis from the outer periphery and protrudes upward.
The light diffusing lens according to claim 6, wherein the absolute value of the inclination of the tangent of the curved surface of the upper surface increases from the outer periphery toward the optical axis.
The light diffusing lens according to claim 6, wherein the upper surface has a circular shape forming a predetermined curvature.
According to claim 1,

The height of the side surface in the minor axis direction is lower than that in the major axis direction.
10. The method of claim 9, The height in the minor axis direction, the light diffusion lens is less than 1 and more than 0.5 in comparison to the height in the major axis direction.
The method of claim 9,

An upper portion of the side surface is a light diffusing lens forming a predetermined curvature.
The method of claim 9,

The height of the short axis direction is 2.8 to 3.0 times the lowest height of the upper surface, the light diffusing lens.
According to claim 1,

The length of the long axis, the light diffusion lens of 1.1 times or more of the length of the short axis.