KR101907064B1 - Optical lens - Google Patents

Abstract

According to an embodiment of the present invention, provided is an optical lens, changing a route of light emitted from a light source. The optical lens includes an irradiating surface protruding to an upper side, a lower surface, and an incident surface concave in the irradiating direction from the lower surface. Moreover, the irradiating surface comprises: a plane having a predetermined radius (R) based on an optical shaft; a first curved surface extending from the plane to the outside and having a first curvature; a second curved surface extending from the first curved surface to the outside and having a second curvature; and a third curved surface extending from the second curved surface to the outside and having a third curvature. Accordingly, the optical lens can form a plurality of curved surfaces on an emitting surface and change the route of a portion of light emitted from the light source so as to increase light diffusion.

Description

Optical lens {OPTICAL LENS}

The embodiment relates to an optical lens for changing the optical path. More particularly, the present invention relates to an optical lens for use in a backlight unit, which changes a light path by forming a plurality of curved surfaces on an outgoing surface on which light is emitted.

Recently, demand for flat panel display devices, which have been improved in size and weight and have improved performance, has been explosively increasing, centering on semiconductor technology which is rapidly developing.

Among these flat panel displays, liquid crystal displays (LCDs), which have been popular in recent years, have advantages such as miniaturization, light weight, and low power consumption, which can overcome the drawbacks of conventional cathode ray tubes Has been gradually attracting attention as an alternative means, and is currently used in almost all information processing devices requiring a display device.

Since the liquid crystal display panel in the liquid crystal display device is a light receiving element that can not emit light by itself, the backlight unit is provided below the liquid crystal display panel to provide light to the liquid crystal display panel. The backlight unit includes a lamp, a light guide plate, a reflective sheet, an optical sheet, and the like. The lamp has a relatively low calorific value and emits white light close to natural light, and has a long lifespan, a cold cathode fluorescent tube type lamp, a LED type lamp using a light emitting diode (hereinafter referred to as "LED") with good color reproducibility and low power consumption Lt; / RTI > Conventionally, cold-cathode tube type lamps have been used, but LED type lamps have begun to be used because LED type lamps have good color reproducibility and low power consumption.

At this time, the LED lamp has a plurality of LEDs for generating light, and the LED lamp has a light distribution in the form of a point light source. The light of the point light source type is converted into the light scattering of the surface light source type in a certain area by the exclusive lens and is emitted.

The point light source of such an LED lamp does not cover a large area per point light source, and the amount of luminance that can be generated per light source is also limited. Accordingly, the backlight unit includes hundreds of LED light sources. In this case, the number of the light sources increases, and the number and area of the PCB substrates used for the light sources increase, resulting in a problem that the manufacturing cost of the backlight increases sharply.

Korean Patent Laid-Open Publication No. 2013-0107849

The embodiment provides an optical lens for changing the path of light irradiated from a light source so that a small number of light sources can be used.

Further, there is provided an optical lens capable of changing the optical path of light having directivity in a specific direction by using a plurality of curved surfaces to secure light diffusibility.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned here can be understood by those skilled in the art from the following description.

According to an embodiment of the present invention, there is provided an optical lens for changing a path of light emitted from a light source, the optical lens comprising: an emitting surface convexly formed upward; Lower surface; And an incident surface formed concavely in the direction of the exit surface from the lower surface, wherein the exit surface has a plane having a predetermined radius (R) with respect to the optical axis; A first curved surface extending outwardly from the plane and having a first curvature; A second curved surface extending outwardly from the first curved surface and having a second curvature; And a third curved surface extending outwardly from the second curved surface and having a third curvature.

Here, the height H1 of the plane may be lower than the height H2 of the third curved surface with respect to the lower surface.

A line L connecting the center C1 of the first curved surface, the center C2 of the second curved surface, and the center C3 of the third curved surface may be disposed in parallel with the lower surface.

The first curved surface, the second curved surface, and the third curved surface may be formed to have the same radius.

The distance D2 from the optical axis to the center C2 of the second curved surface may be 1.25 when the distance D1 from the optical axis to the center C1 of the first curved surface is 1.

Further, when the distance D1 from the optical axis to the center C1 of the first curved surface is 1, the distance D3 from the optical axis to the center C3 of the third curved surface may be 1.5.

In addition, the radius of the third curved surface and the distance D3 from the optical axis to the center C3 of the third curved surface may be the same.

In addition, when the distance D1 from the optical axis to the center C1 of the first curved surface is 1, the radius R of the plane may be 0.4.

The optical lens may further include a protrusion disposed between the emission surface and the lower surface and protruding outward from an edge of the emission surface, wherein the protrusion has a radius (R) at the edge of the emission surface with respect to the optical axis (C) Side surfaces spaced apart from each other by a predetermined distance d; And a connection surface disposed between the side surface and the emission surface, and the side surface may be inclined outwardly at a predetermined angle (?) From the bottom surface.

At this time, part of the light incident through the incident surface may be reflected by the first curved surface to one side of the third curved surface and the side surface of the protruded portion.

Further, part of the light incident on the second curved surface through the incident surface may be reflected by the second curved surface to the side surface of the projection.

Also, the connection surface of the protrusion may be disposed on the line L.

The optical lens according to the embodiment can form a plurality of curved surfaces on the exit surface to change the optical path of a part of the light emitted from the light source to improve the light diffusibility.

Preferably, the light diffusing property can be improved by refracting and dispersing light using a plurality of curved surfaces.

The various and advantageous advantages and effects of the present embodiment are not limited to the above description, and can be more easily understood in the course of describing a specific embodiment of the present embodiment.

1 is a perspective view showing an optical lens according to an embodiment,
2 is a plan view showing an optical lens according to an embodiment,
3 is a side view showing an optical lens according to an embodiment,
4 is a bottom view showing an optical lens according to an embodiment,
5 is a cross-sectional perspective view showing an optical lens according to an embodiment,
6 is a cross-sectional view showing an optical lens according to the embodiment,
7 is a view showing an optical path of the optical lens according to the embodiment,
8 is a view showing an optical path by a plane in an outgoing plane of an optical lens according to the embodiment,
9 is a view showing an optical path by the first curved surface of the exit surface of the optical lens according to the embodiment,
10 is a view showing an optical path by the second curved surface of the exit surface of the optical lens according to the embodiment,
11 is a view showing an optical path by the third curved surface of the exit surface of the optical lens according to the embodiment,
12 is a view showing a light path by the side surface of the protruding portion of the optical lens according to the embodiment,
13 is a view showing a light source for irradiating light onto an incident surface of an optical lens according to the embodiment.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

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

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

In the description of the embodiments, when an element is described as being formed "on or under" another element, the upper or lower (lower) (on or under) all include that the two components are in direct contact with each other or that one or more other components are indirectly formed between the two components. Also, when expressed as 'on or under', it may include not only an upward direction but also a downward direction based on one component.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

2 is a plan view showing an optical lens according to an embodiment, FIG. 3 is a side view showing an optical lens according to an embodiment, and FIG. 4 is a cross- FIG. 5 is a cross-sectional perspective view showing an optical lens according to the embodiment, and FIG. 6 is a cross-sectional view showing an optical lens according to the embodiment.

1 to 6, a light diffusion lens 1 according to an embodiment of the present invention may include an emission surface 100, a lower surface 200, a protrusion 300, and an incident surface 400 have. The optical lens 1 can change the path of the light emitted from the light source 10. As shown in FIG. 7, the optical lens 1 diffuses the light emitted from the light source 10 by using a plurality of curved surfaces formed on the emission surface 100.

At this time, the optical lens 1 may be formed using a material of polycarbonate or polymethymethylacrylate. Here, the refractive index of the polycarbonate is 1.58, and the refractive index of the polymethylacrylate is 1.49.

The emitting surface 100 may be formed convex toward the upper side. A part of the light incident into the optical lens 1 through the incident surface 400 is emitted through the exit surface 100. Herein, the terms 'upper side' and 'lower side' are relative expressions. If there is no definition below, the direction from the lower surface 200 to the emission surface 100 is defined as the upper side (upper side) 100) to the lower surface 200 is defined as the lower side (lower side).

The emitting surface 100 may be formed to be convex in the optical axis direction (z direction) with the optical axis C as the center. Accordingly, a part of the light incident through the incident surface 400 can be refracted by the shape of the emitting surface 100 and emitted to the outside. Here, the optical axis C is the center of the light irradiated by the light source 10, and may coincide with the center of the optical lens 1. [

Accordingly, the optical lens 1 improves the diffusibility of the light through the shape of the exit surface 100, thereby obtaining a uniform light distribution as a whole.

1 to 6, an exit surface 100 includes a plane 110 having a predetermined radius R with respect to an optical axis C, a first curved portion 110 extending outward from the plane 110, A second curved surface 130 extending outward from the first curved surface 120 and having a second curvature and a third curved surface 140 extending outward from the second curved surface 130 and having a third curvature, ). At this time, the plane 110, the first curved surface 120, the second curved surface 130, and the third curved surface 140 may be rotationally symmetric with respect to the optical axis C. [

The plane 110 may be disposed on the optical axis C to change the optical path of the light incident through the incident surface 400.

The plane 110 may diffuse the light incident through the incident surface 400. As shown in FIG. 8, the light emitted from the light source 10 and passing through the incident surface 400 is incident on the plane 110 at a predetermined angle. Accordingly, the light incident on the plane 110 can be refracted and diffused at a predetermined angle.

The plane 110 may be formed in a planar shape. As shown in FIG. 2, the plane 110 may be formed to have a predetermined radius R with respect to the optical axis C. The plane 110 may be disposed parallel to the lower surface 200.

5, the height H1 of the flat surface 110 may be lower than the height H2 of the third curved surface 140 with respect to the lower surface 200. As shown in FIG. As shown in FIG. 7, the amount of refraction of the light refracted through the third curved surface 140 is larger than the amount of light refracted through the plane 110 with respect to the optical axis C.

On the other hand, when the distance D1 from the optical axis to the center C1 of the first curved surface 120 is 1, the radius R of the plane 110 may be 0.4.

The first curved surface 120 may be formed to extend outward from the plane 110. At this time, the first curved surface 120 may be formed with a predetermined first curvature 1 / R1. For example, the first curved surface 120 may be formed in an arc shape with respect to a vertical cross section. Accordingly, the first curved surface 120 can be formed with a predetermined radius R1 with respect to the center C1.

As shown in Figs. 1 and 2, the first curved surface 120 may be formed in a ring shape on a plane.

9, the first curved surface 120 is formed with the first curvature 1 / R1, and a part of the light incident on the first curved surface 120 may be refracted outward. The other part of the light incident on the first curved surface 120 may be reflected by the first curved surface 120 to one side of the third curved surface 130 and the side surface 310 of the protruding part 300. A portion of the light incident on one side of the third curved surface 130 and the side surface 310 of the protrusion 300 may be emitted to the outside or may be reflected to the bottom surface 200.

Therefore, the light diffusion lens 1 can improve the light diffusing property through the first curved surface 120.

The second curved surface 130 may be formed to extend outward from the first curved surface 120. At this time, the second curved surface 130 may be formed with a predetermined second curvature 1 / R2. For example, the second curved surface 130 may be formed in an arc shape with respect to a vertical cross section. Accordingly, the second curved surface 130 may be formed with a predetermined radius R2 based on the center C2.

As shown in Figs. 1 and 2, the second curved surface 130 may be formed in a ring shape on a plane.

10, the second curved surface 130 is formed with the second curvature 1 / R2, and a part of the light incident on the second curved surface 130 may be refracted out. Another portion of the light incident on the second curved surface 130 may be reflected by the second curved surface 130 to the side surface 310 of the protruded portion 300. A part of the light incident on one area of the third curved surface 130 and the side surface 310 of the protruding part 300 may be emitted to the outside. Since the side surface 310 is inclined at a predetermined angle?, The light reflected through the second curved surface 130 can be emitted to the outside through the side surface 310.

Therefore, the light diffusion lens 1 can improve the light diffusing property through the second curved surface 130.

On the other hand, when the distance D1 from the optical axis to the center C1 of the first curved surface 120 is 1, the distance D2 from the optical axis C to the center C2 of the second curved surface 130 is 1.25.

The third curved surface 140 may be formed to extend outward from the second curved surface 130. At this time, the third curved surface 140 may be formed with a predetermined third curvature (1 / R3). For example, the third curved surface 140 may be formed in an arc shape with respect to the vertical cross section. Accordingly, the third curved surface 140 may be formed with a predetermined radius R3 with respect to the center C3.

As shown in Figs. 1 and 2, the third curved surface 140 may be formed in a ring shape on a plane.

11, the third curved surface 140 is formed with the second curvature 1 / R3, and the light incident on the third curved surface 140 can be refracted out and emitted.

Therefore, the light diffusion lens 1 can improve the light diffusing property through the third curved surface 140.

On the other hand, when the distance D1 from the optical axis to the center C1 of the first curved surface 120 is 1, the distance D3 from the optical axis C to the center C3 of the third curved surface 140 is 1.5.

The height H2 of the third curved surface 140 may be greater than the height H1 of the flat surface 110 with respect to the lower surface 200.

The distance D3 from the radius R3 of the third curved surface 140 to the center C3 of the third curved surface 140 from the optical axis C may be the same.

On the other hand, an imaginary line L connecting the center C1 of the first curved surface 120, the center C2 of the second curved surface 130 and the center C3 of the third curved surface 140, As shown in Fig. At this time, the radii R1, R2, and R3 of the first curved surface 120, the second curved surface 130, and the third curved surface 140 may be formed to have the same radius.

The lower surface 200 may be provided in a plane. As shown in FIG. 4, the lower surface 200 may be formed in a circular shape having a predetermined radius. Here, although the lower surface 200 is provided as a plane, it is not limited thereto.

For example, the lower surface 200 may have a flat surface extending from the edge to a certain length in the center direction, and a lower convex surface (not shown) may be formed from the end of the flat surface toward the center. The lower convex surface may be convex downward.

That is, the lower surface 200 may have a curvature of zero for a predetermined length from the edge to the center, but may have a shape in which the curvature increases from the predetermined length to the center, then decreases again.

The light emitted from the light source 10 to the lower side can be totally reflected to the upper side in the case of the lower surface 200 having the lower convex surface as compared with the lower surface composed of only the plane.

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

The protrusion 300 may be disposed between the emitting surface 100 and the lower surface 200. As shown in FIG. 2, the protrusion 300 may protrude outwardly to have a predetermined distance d from the outer circumference of the third curved surface 140.

1 to 5, the protrusion 300 may include a side surface 310 and a connection surface 320.

The side surface 310 may be spaced apart from the outer circumference of the third curved surface 140 by a predetermined distance d in the radial direction (x direction) with respect to the optical axis C. Accordingly, in the case of the light that is emitted through the side surface 310 among the light that moves along the inside of the optical lens 1, the light advances by at least the distance d away from the light emitted through the emitting surface 100, . Therefore, the optical lens 1 can improve the diffusibility of light through the protrusion 300. At this time, the light emitted through the side surface 310 can be refracted by the refractive index difference between the optical lens 1 and the outside.

Referring to FIG. 3, the side surface 310 may be formed to be inclined outwardly at a predetermined angle (?) At the lower surface 200. Accordingly, the light diffusing property of the optical lens 1 can be improved.

12, the light incident through the incident surface 400 is refracted to the light irradiation direction (upper side) by the inclined side surface 310 at a predetermined angle & tilde & Can be improved. Here, the light incident through the incident surface 400 may be light emitted from the side light emitting surface 12 of the light source 10.

The connecting surface 320 may be disposed between the emitting surface 100 and the side surface 310. In detail, the connecting surface 320 may be formed to extend from the outer circumference of the third curved surface 140 to the upper edge of the side surface 310. The distance d may be adjusted according to the size of the connecting surface 320 as viewed from above.

The coupling surface 320 may be disposed at a predetermined angle with respect to the side surface 310. In the case of light emitted from the coupling surface 320, May occur. Accordingly, the optical diffusivity of the optical lens 1 can be further improved.

In addition, the area where the side surface 310 and the connection surface 320 meet can be rounded to a predetermined curvature. Accordingly, the optical diffusivity of the optical lens 1 is further improved, and uniformity can be ensured by the light emitted from the region.

As shown in FIG. 6, the connecting surface 320 may be disposed on the line L. As shown in FIG.

The incident surface 400 may be concave in the direction of the emitting surface 100 from the center of the lower surface 200. That is, the incident surface 400 may be provided with a groove whose vertical section is semi-elliptical or parabolic.

Accordingly, an air layer may be disposed between the light source 10 and the incident surface 400. Therefore, in the case of the light emitted from the light source 10 to the air layer, the refractive index can be refracted at the incident surface 400 of the optical lens 1 having a different refractive index.

Meanwhile, as the incident surface 400 is formed, the optical lens 1 may be formed with an incidence aperture E.

As shown in FIG. 3, the entrance E may be formed in a circular shape at a central portion of the lower surface 200, but is not limited thereto. The light source 10 may be disposed at the center of the incident aperture E.

The incident surface 400 is a surface portion where light emitted from the light source 10 located at the entrance E enters into the optical lens 1. [ The light incident on the incident surface 400 through the incident surface 400 may be refracted through the exit surface 100 and the protrusion 300 and may be emitted to the outside.

13 is a view showing a light source for irradiating light onto an incident surface of an optical lens according to the embodiment.

Referring to FIG. 13, the light source 10 for emitting light toward the incident surface 400 may include an upper light emitting surface 11 and four side light emitting surfaces 12. Accordingly, the light source 10 can realize five-sided light emission.

At this time, the light emitted from the upper light emitting surface 11 of the light source 10 is irradiated in the optical axis direction (z direction), and the light emitted from the side light emitting surface 12 may be radiated in the radial direction (x direction) .

Here, the light source 10 may be an LED. The LED may be coated with a yellow phosphor.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the appended claims. It will be understood that the present invention can be changed. It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

1: optical lens 10: light source
100: exit surface 110: plane
120: first curved surface 130: second curved surface
140: Third surface
200: Lower surface
300: protrusion
310: side surface 320: connection surface
400: incidence plane
500: incidence plane
C: optical axis

Claims (12)

An optical lens for changing a path of light emitted from a light source,
An emission surface convexly formed on the upper side;
Lower surface; And
And an incident surface formed concavely in the direction of the exit surface from the lower surface,
The exit surface
A plane having a predetermined radius (R) with respect to an optical axis;
A first curved surface extending outwardly from the plane and having a first curvature;
A second curved surface extending outwardly from the first curved surface and having a second curvature; And
A third curved surface extending outwardly from the second curved surface and having a third curvature,
Wherein a line L connecting the center C1 of the first curved surface, the center C2 of the second curved surface and the center C3 of the third curved surface is disposed in parallel with the lower surface. The method according to claim 1,
Wherein a height (H1) of the plane with respect to the lower surface is lower than a height (H2) of the third curved surface. delete The method according to claim 1,
Wherein the first curved surface, the second curved surface, and the third curved surface have the same radius. 5. The method of claim 4,
And a distance (D1) from the optical axis to the center (C1) of the first curved surface is 1,
And a distance (D2) from the optical axis to a center (C2) of the second curved surface is 1.25. 5. The method of claim 4,
And a distance (D1) from the optical axis to the center (C1) of the first curved surface is 1,
And a distance (D3) from the optical axis to the center (C3) of the third curved surface is 1.5. 5. The method of claim 4,
The distance D3 from the radius of the third curved surface to the center C3 of the third curved surface from the optical axis is the same. 5. The method of claim 4,
And a distance (D1) from the optical axis to the center (C1) of the first curved surface is 1,
And the radius (R) of the plane is 0.4. 5. The method of claim 4,
And a protrusion disposed between the emission surface and the lower surface and protruding outward from an edge of the emission surface
The projection
A side surface spaced from the edge of the emitting surface by a predetermined distance d in the radial direction with respect to the optical axis C; And
And a connection surface disposed between the side surface and the emission surface,
Wherein the side surface is formed to be inclined outwardly at a predetermined angle (&thetas;) on the lower surface. 10. The method of claim 9,
Wherein some of the light incident through the incident surface is reflected by the first curved surface to one side of the third curved surface and the side surface of the protruded portion. 10. The method of claim 9,
And a part of the light incident on the second curved surface through the incident surface is reflected by the second curved surface to the side surface of the projection. 10. The method of claim 9,
And the connecting surface is disposed on the line (L).

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