KR102516614B1 - Optical lens, optical module having the optical lens and backlight unit having the optical module - Google Patents

Abstract

This embodiment discloses an optical lens, a light source module including the same, and a backlight unit including the same. The disclosed optical lens, a light source module including the same, and a backlight unit including the same are convex from a bottom surface and a bottom surface, and a first width based on a first direction on a plane is a second direction perpendicular to the first direction. An optical lens comprising a recess longer than the second width as a reference and a light exit surface located on the opposite side of the bottom surface and having a third width relative to the first direction on a plane that is shorter than the fourth width relative to the second direction. include Through this, it is possible to widen the beam angle of light in a specific direction.

Description

Optical lens, optical module having the same, and backlight unit having the same

The present embodiment relates to an optical lens, an optical module including the same, and a backlight unit including the same.

In recent years, centered on rapidly developing semiconductor technology, demand for a flat panel display device with improved performance while being smaller and lighter is explosively increasing.

Among these flat panel display devices, the liquid crystal display (LCD), which has recently been in the spotlight, has advantages such as miniaturization, light weight, and low power consumption, and can overcome the disadvantages of the existing cathode ray tube (CRT). It has been gradually attracting attention as an alternative means for display devices, and is currently used by being installed in almost all information processing devices that require a display device.

Since the liquid crystal display panel in the liquid crystal display device cannot emit light by itself, a backlight unit is provided below the liquid crystal display panel to provide light to the liquid crystal display panel. The backlight unit includes a light source, a light guide plate, and a plurality of optical sheets.

Meanwhile, the backlight unit is divided into an edge-type backlight unit and a direct-type backlight unit according to a position where a light source provides light to the liquid crystal display panel. The edge type is a method in which a light source is positioned on the side of the liquid crystal display panel to provide light from the side of the display panel, and the direct type is a method in which a light source is positioned on the rear surface of the liquid crystal display panel to provide light from the rear surface of the display panel.

Among the backlight units, in the case of a direct type backlight unit, light emitted from a light source tends to be concentrated in a frontal direction due to strong linearity. Therefore, there is a problem in that the light is not evenly distributed throughout the liquid crystal display panel, so that the light source is brighter in a portion corresponding to the front of the light source and becomes darker as the distance from the front is increased.

In addition, depending on the arrangement of the light source, it is necessary to diffuse more light only in a certain direction. For example, when the left and right intervals of the light sources are more densely arranged than the up and down intervals, a more uniform light distribution can be obtained when the light is diffused more in the vertical direction and less in the left and right directions. As such, there is an increasing demand for a technology capable of asymmetrically diffusing light emitted from a light source.

The present embodiment is intended to solve the above problems, and provides an optical lens capable of spreading light asymmetrically, an optical module including the same, and a backlight unit including the same.

The optical lens according to the present embodiment, the optical module including the same, and the backlight unit including the same have a bottom surface, a convex surface from the bottom surface, and a first width based on a first direction on a plane that perpendicularly intersects the first direction. A recess longer than the second width in the second direction and a light exit surface located on the opposite side of the bottom surface and having a third width in the first direction on a plane that is shorter than the fourth width in the second direction provide

The optical lens according to the present embodiment, the optical module including the same, and the backlight unit including the same are made to correspond to the short axis of the optical lens in an area corresponding to the long axis of the recess on a plane, thereby changing the beam angle of light in a specific direction. It can be widened, and even if the number of optical lenses included in the backlight unit is reduced, there is an effect of satisfying luminance uniformity.

1 is a plan view of an optical lens according to this embodiment.
FIG. 2 is a view of FIG. 1 taken along AB.
FIG. 3 is a cross-sectional view of FIG. 1 taken along CD.
FIG. 4 is a view showing the specific configuration of an optical module including the height of the outer diameter and the height of the recess and the optical lens of the optical lens according to the present embodiment.
5 is a diagram illustrating a backlight unit including an optical module according to an exemplary embodiment.
6 is a diagram illustrating light distribution of a light source unit including an optical module according to an exemplary embodiment.
7 is a diagram illustrating a light source lens according to a comparative example.
8 is a diagram illustrating a light path emitted from an optical module including a light source lens according to a comparative example.
9 is an image showing the distribution of light emitted from the optical module according to the present embodiment.
FIG. 10 is a diagram illustrating a form in which an optical lens is disposed on a circuit board in an optical module including an optical lens according to a comparative example.
FIG. 11 is a diagram showing a form in which an optical lens is disposed on a circuit board in an optical module including an optical lens according to an exemplary embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Accordingly, the present invention may be embodied in other shapes without being limited to the embodiments described below. And in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different shapes, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of explanation.

When an element or layer is referred to as “on” or “on” another element or layer, it includes both cases where another element or layer is intervening as well as directly on another element or layer. do. On the other hand, when an element is referred to as “directly on” or “directly on”, it indicates that no other element or layer is intervening.

The spatially relative terms "below, beneath", "lower", "above", "upper", etc., refer to one element or component as shown in the drawing. It can be used to easily describe the correlation between and other elements or components. Spatially relative terms should be understood as terms that include different orientations of elements in use or operation in addition to the directions shown in the figures. For example, when flipping elements shown in the figures, elements described as “below” or “beneath” other elements may be placed “above” the other elements. Thus, the exemplary term “below” may include directions both below and above.

Also, terms such as first, second, A, B, (a), and (b) may be used in describing the components of the present invention. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the corresponding component is not limited by the term. When an element is described as being “connected,” “coupled to,” or “connected” to another element, that element is or may be directly connected to that other element, but intervenes between each element. It will be understood that may be "interposed", or each component may be "connected", "coupled" or "connected" through other components.

Terminology used herein is for describing the embodiments, and therefore is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprise" and/or "comprising" means that a stated component, step, operation, and/or element is the presence of one or more other components, steps, operations, and/or elements. or do not rule out additions.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a plan view of an optical lens according to this embodiment. FIG. 2 is a view of FIG. 1 taken along line A-B. FIG. 3 is a cross-sectional view of FIG. 1 taken along line C-D.

First, referring to FIG. 1 , the optical lens 100 according to the present embodiment includes a bottom surface, a recess 115, a light incident surface 110, and a light exit surface 135. Specifically, the optical lens 100 according to the present embodiment includes a convex recess 115 from the bottom surface, a light incident surface 110 around the recess 115, and a first light exit surface disposed on the opposite side of the bottom surface ( (not shown) and a second light exit surface 135 disposed around the lower portion of the first light exit surface.

Meanwhile, although not shown in the drawing, a plurality of support units for supporting the optical lens 100 disposed on the circuit board may be further provided on the bottom surface of the optical lens 100 .

The optical lens 100 may be used in various ways, and may be provided in, for example, a backlight unit of a display device. Specifically, it can be used as one of the components of the light source module of the backlight unit.

On the other hand, optical lenses can generally be divided into reflective optical lenses and refractive optical lenses. In the case of a reflective optical lens, a light output path through which light provided from a light source is emitted is in a bottom or side direction of the lens, and light emitted from the lens is reflected on a reflective surface. In the case of a refractive optical lens, a light output path through which light provided from a light source is emitted is in a direction above the lens, and light is refracted at a boundary between the lens and the outside of the lens to be emitted to the outside of the lens.

These reflective optical lenses and refractive optical lenses are both symmetrical. In the case of reflective optical lenses, the light provided to the lens is reflected by the reflective surface, so the focus depends on the conditions of the reflective surface, such as the location and angle of the reflective surface. There is this changing problem. In order to prevent the aforementioned change in focus of light, a method of using additional components or redesigning a pitch of a light source has been proposed.

However, the method using additional parts has a problem of increasing cost, and even if the pitch of the light source is redesigned, there is a problem that it is difficult to mix with light emitted from other adjacent optical lenses due to the light exit path of the reflective optical lens.

In addition, since it is difficult to redesign the pitch of the light source when the reflective optical lens is used for the above reasons, the distance between the light source and the reflective optical lens located above the light source and other light sources and the reflective optical lens is adjusted. There is a limit to controlling the size of an optical module in which an optical lens is mounted.

In the case of a refractive optical lens, compared to a reflective optical lens, it is easier to adjust the distance between a light source and a refractive optical lens positioned above the light source and another light source and a refractive optical lens, but the maximum brightness of the light emitted from the refractive optical lens There is a problem in that the beam angle of light emitted from the refractive optical lens must be widened in order to widen the area (coverage, hereinafter referred to as the light spread range) from the point to the point where the maximum brightness is 1/2.

In order to solve this problem, the refractive index of the material constituting the lens should be high or the size of the lens should be increased. However, there is a limit to developing a material with a high refractive index, and since the currently used lens material has poor ejectability, there is a problem in manufacturing a large lens.

In addition, the refractive optical lens is generally a lens having an isotropic light distribution, and an optical module including such a refractive optical lens has a structure in which a light source and an optical lens cannot be arranged vertically and horizontally symmetrically.

In order to compensate for this structural disadvantage, the upper and lower light spreading range should be wide compared to the left and right. .

The optical lens 100 according to the present embodiment is intended to solve this problem, and the recess 115 of the optical lens 100 and the external shape of the optical lens 100 (eg, the shape of the light exit surface) are changed. Thus, the optical lens 100 has an anisotropic light distribution.

At the same time, the optical lens 100 according to the present embodiment is a kind of refractive optical lens 100, and light is refracted at the boundary between the lens and the outside of the lens without the need to use a reflection surface for determining the focus of light to the outside of the lens. Since light is emitted, it may be easier to reduce the light source module including the light source and the optical lens 100 than when using a reflective optical lens.

Looking in detail at the shape of the optical lens 100 according to the present embodiment, the recess 115 of the optical lens 100 has a first width W1 based on the first direction on a plane and It may be longer than the second length W2 based on the intersecting second direction. Here, the second direction may be a direction perpendicular to the first direction. Also, the second light emitting surface 135 of the optical lens 100 may have a third width W3 based on the first direction on a plane that is shorter than a fourth length W4 based on the second direction. . That is, a region corresponding to the long axis of the recess 115 on a plane may correspond to the short axis of the optical lens 100 .

Since the optical lens 100 according to the present embodiment has the above-described shape, an optical module using the optical lens 100 according to the present embodiment may have an anisotropic light distribution.

These configurations are specifically reviewed with reference to FIGS. 2 and 3 as follows. Specifically, FIG. 2 is a cross-sectional view of the planar optical lens 100 taken along a first direction, and FIG. 3 is a cross-sectional view of the planar optical lens 100 taken along a second direction.

The optical lens 100 shown in FIGS. 2 and 3 and the recess 115 provided inside the optical lens 100 may have a shape such as an ellipse or a semi-ellipse in cross-sectional view, and the lower shape of the surface is a circle. It can be shaped or polygonal. And, the first exit surface 130 of the optical lens 100 is made of a curve in cross section, and the second exit surface 135 is located on the lower circumference of the first exit surface 130 and has a flat surface extending. can

A light source 150 is disposed below the optical lens 100 . The optical lens 100 includes a recess 115 recessed from the center of the bottom surface 110 toward the second direction or the optical axis X direction. The optical lens 100 may receive light emitted from the light source 150 to the light incident surface 110 and emit the light to the first and second light exit surfaces 130 and 135 .

Meanwhile, although not shown in the drawing, the light source 150 may receive power through a circuit board disposed under the light source 150 . Here, the light source 150 may include at least one of an LED chip having a compound semiconductor, for example, an Ultraviolet (UV) LED chip, a blue LED chip, a green LED chip, a white LED chip, and a red LED chip. The light source 150 may include at least one or both of a group II-VI compound semiconductor and a group III-V compound semiconductor, but the present embodiment is not limited thereto.

In addition, the light source 150 may emit at least one of blue, green, blue, UV, or white light. Meanwhile, in the above description, the light source 150 applied to the present embodiment is mainly described as an LED chip, but the present embodiment is not limited thereto, and the light source 150 can transmit light to the optical lens 100. A configuration that exists is sufficient.

Meanwhile, in FIG. 2 in which the planar optical lens 100 is cut along the first direction, the first width W1 of the recess 115 is obtained when the planar optical lens 100 is cut along the second direction. It may be longer than the second width W2 of the recess 115 in FIG. 3 . Here, the first width W1 is the maximum width of the recess 115 in the first direction, and the second width W2 is the maximum width of the recess 115 in the second direction. means

In addition, in FIG. 2 in which the planar optical lens 100 is cut in the first direction, the third width W3 of the optical lens 100 is obtained when the planar optical lens 100 is cut in the second direction. It may be shorter than the fourth width W4 of the optical lens 100 in FIG. 3 .

Meanwhile, the optical lens 100 may include a first light emitting surface 130 and a second light emitting surface 135 connected to the first light emitting surface 130 and located below the first light emitting surface 130 .

Here, the third width W3 of the optical lens 100 described above means the maximum width of the second light exit surface 135 of the optical lens 100 in FIG. 2, and the fourth width W4 in FIG. This means the maximum width of the second light exit surface 135 of the lens 100.

That is, the third width W3 of the optical lens 100 may be used in the same meaning as the third width W3 of the second light emitting surface 135, and the fourth width W4 of the optical lens 100 is It may be used in the same meaning as the fourth width W4 of the second light exit surface 135 . On the other hand, the fourth width W1 corresponds to the length of the major axis of the second light exit surface 135 on a plane, and the third width W3 corresponds to the short axis of the second light exit surface 135 on a plane. corresponds to the length. Here, the width of the second light emitting surface 135 surface of the optical lens 100 acts as a variable capable of changing the beam angle, and this will be dealt with in more detail in the following description.

Specifically, the first width W1 of the aforementioned recess 115 may be 1.2 to 1.3 times the second width W2 . Also, the fourth width W4 of the optical lens 100 may be 1.04 to 1.06 times the third width W3. Since each width of the recess 115 and the optical lens 100 is formed as described above, the beam angle of light emitted in a specific direction can be made larger than the beam angle of light emitted in other directions except for the specific direction.

In other words, in the recess 115, the first width W1, which is the maximum width in the first direction, is longer than the second width W2, which is the maximum width in the second direction, and the optical lens 100 The third width W3, which is the maximum width in the first direction, may be shorter than the fourth width W4, which is the maximum width in the second direction.

That is, while the first width W1 of the recess cut in the first direction is longer than the second width W2, the third width W3 of the optical lens 100 cut in the first direction ) may be shorter than the fourth width W4. Through this, as the light emitted from the light source 150 passes through the optical lens 100 including the recess 115, the beam angle of light may be expanded in a partial area.

Meanwhile, the shape and plane size of the recess 115 and the shape of the optical lens 100 have a close relationship with the beam angle of light. Here, the beam angle of light means a light emitting area after the light emitted from the light source 150 passes through the light source lens 100 .

First, the relationship between the shape and plane size of the recess 115 and the beam angle is as follows. The light emitted from the light source 150 travels at a specific beam angle and is incident on the light incident surface 110 of the recess 115, which is the first light incident surface. At this time, as the size of the plane of the recess 115 widens, the light incident area increases, and the amount of light incident on the recess 115 increases, and the light spreads over a wide area. In this way, if the light spreads over a wide area, the beam angle of the light emitted through the light exit surfaces 130 and 135 may also increase.

Meanwhile, the shape of the recess 115 according to the present embodiment is an elliptical shape in plan view as shown in FIG. 1 . As described above, since the recess 115 according to the present embodiment is formed in an elliptical shape on a plane, the angle of view may vary for each area.

Specifically, the radius of curvature of the recess 115 may be larger in the region corresponding to region a of FIG. 1 than in the region corresponding to region b. Since the surface area of the recess 115 decreases as the radius of curvature increases, the incident amount of light decreases. On the other hand, as the radius of curvature decreases, the surface area of the recess 115 increases, increasing the incident love of light and increasing refraction. Therefore, the incident amount and refractive index of light in the region corresponding to region b of the recess 115 may be greater than the incident amount and refractive index of light in the region corresponding to region a of the recess 115 . Here, the meaning that the degree of refraction of light is high means that the beam angle of light is increased.

In addition, since the length of the recess 115 in the first direction is longer than the length in the second direction, as shown in FIGS. 2 and 3 , the size of the plane of the recess 115 based on the first direction is It becomes larger than the planar size of the recess 115 based on the second direction. Therefore, the light passing through the light incident surface 110 of the recess 115 based on the first direction is final compared to the light passing through the light incident surface 110 of the recess 115 based on the second direction. When the light passes through the light exit surfaces 130 and 135, the beam angle can be widened. That is, the recess 115 of the optical lens 100 according to the present embodiment provides an effect of widening the beam angle of light in a specific direction.

Second, the relationship between the external shape of the optical lens 100 and the directing angle of light is as follows. Light emitted from the light source 150 is refracted while passing through the light incident surface 110 of the recess 115 . The light to be refracted is incident on the first and second light exit surfaces 130 and 135 of the optical lens 100 . In this case, the path of the light incident on the first and second light exit surfaces 130 and 135 may be further extended by the first and second light exit surfaces 130 and 135 .

Meanwhile, the planar shape of the optical lens 100 according to the present embodiment is an elliptical shape as shown in FIG. 1 . As such, since the planar shape of the optical lens 100 according to the present embodiment is formed in an elliptical shape, the angle of view may vary for each area.

Specifically, as shown in FIG. 1, both the planar shape of the optical lens 100 and the planar shape of the recess 115 are elliptical shapes. However, the region having the fourth width W4 of the optical lens 100 may be in a direction perpendicular to the region having the first width W1 of the recess 115 on a plane. On the other hand, the region having the first width W1 of the recess 115 and the region having the third width W3 of the scientific lens 100 may be positioned to correspond to each other. Accordingly, the length from the surface of the recess 115 to the outer diameter of the optical lens 100 may be the shortest in the first direction, and the distance from the surface of the recess 115 to the outer diameter of the optical lens 100 increases from the first direction to the second direction. The length to the outer diameter of (100) becomes longer.

The distance between the outer diameter of the optical lens 100 and the surface of the recess 115 and the width of the recess 115 determine the degree of refraction and straightness of light incident on the optical lens 100 .

Specifically, as the distance between the outer diameter of the optical lens 100 and the surface of the recess 115 is smaller and the width of the recess 115 is larger, the degree of refraction of light increases and the degree of straightness decreases. Further, as the distance between the outer diameter of the optical lens 100 (emission surface of the optical lens) and the surface of the recess 115 and the width of the recess 115 decrease, the degree of refraction of light decreases and the degree of straightness increases.

Therefore, the light passing through the light source lens 110 in the region where the recess 115 has the second width W2 passes through the light source lens 110 in the region where the recess 115 has the first width W1. It is more likely to be refracted and emitted than the passing light. In particular, among the light passing through the recess 115, light passing through an area in which the recess 115 has the first width W1 may have the widest beam angle. As the light passes through, it is further refracted, so that the beam angle of light can be wider than when the light passes through the recess 115.

That is, in the optical lens 100 according to the present embodiment, a light directing path in a specific direction may be changed by forming the recess 115 and the optical lens 100 in an elliptical shape on a plane, respectively.

Meanwhile, in the above description, the shorter the distance between the outer diameter of the optical lens 100 and the surface of the recess 115, the higher the degree of refraction of light incident on the light exit surfaces 130 and 135 of the optical lens 100. mentioned. Based on these conditions, the outer diameter of the optical lens 100 according to the present embodiment and the recess 115 may have a height ratio of a specific condition, which is reviewed with reference to FIG. 4 as follows.

FIG. 4 is a view showing the specific configuration of an optical module including the height of the outer diameter and the height of the recess and the optical lens of the optical lens according to the present embodiment. Referring to FIG. 4 , the optical module includes a circuit board 700 , a light source 150 and an optical lens 100 . Here, the optical lens 100 is disposed on the circuit board 700, and the light source 150 is disposed between the optical lens 100 and the circuit board 700. The light source 150 may receive power from the circuit board 700 and emit light.

And, the optical lens 100 has a recess 115 having a convex shape from the circuit board 700, and has a bottom surface 120, a first light emitting surface 130, and a second light emitting surface. Here, the bottom surface 120 may include a flat surface, a curved surface, or a curved surface and a flat surface. The bottom surface 120 may be provided as an inclined surface with respect to the first direction.

The second light exit surface 135 may be a surface connected to the bottom surface 120 and extending in the optical axis direction. Also, the first light exit surface 130 may be connected to the second light exit surface 135 and formed as a spherical surface through which light is emitted to the entire area. The center region of the first light emitting surface 130 may be a vertex 131 or a high point, and includes a curved shape continuously connected from the vertex 131 . The first light exit surface 130 may refract incident light and emit it to the outside. In the first light emitting surface 130, based on the optical axis X, an emission angle of light emitted to the first light emitting surface 130 after refraction may be greater than an incident angle before refraction.

Meanwhile, the center area of the first light exit surface 130 is an area adjacent to the optical axis X, and may be a curved surface convex upward or a flat surface. An area between the center area of the first light emitting surface 130 and the second light emitting surface 135 may be provided in a convex curved shape.

The second light exit surface 135 is disposed around the lower portion of the first light exit surface 130 to refract and emit incident light. The second light exit surface 135 includes an aspherical shape or a flat surface. The second light emitting surface 135 may be, for example, a surface perpendicular to the top surface of the circuit board 700 or an inclined surface. The second light exit surface 135 receives some light emitted from the side of the light source 150, refracts it, and extracts it. In this case, the second light exit surface 135 may have an exit angle of the emitted light smaller than an incident angle before refraction with respect to the optical axis X. Accordingly, it is possible to provide a long optical interference distance between adjacent optical lenses 100 .

Also, the fourth width W4 of the optical lens 100 may be greater than the maximum height H2 of the optical lens 100 . Here, the maximum height H2 of the optical lens 100 is defined from a position corresponding to the bottom surface of the light source 150 to the apex 131 of the second light emitting surface 135 . As described above, since the fourth width W4 of the optical lens 100 is larger than the maximum height H2 of the optical lens 100, it is possible to provide a uniform luminance distribution over the entire area of the backlight unit, and also as a light source. The thickness of the unit can be reduced.

Also, the maximum height H2 of the optical lens 100 may be higher than the maximum height H1 of the recess 115 . Here, the maximum height H1 of the recess 115 is defined from a position corresponding to the bottom surface of the light source 150 to the vertex 111 of the recess 115 . And, the maximum height H2 of the optical lens 100 is defined from a position corresponding to the bottom surface of the light source 150 to the apex 131 of the first light emitting surface 130 .

Meanwhile, in the present embodiment, the maximum height H2 of the optical lens 100 may be 1.05 to 1.3 times the maximum height H1 of the recess 115 . When the maximum height H1 of the recess 115 with respect to the maximum height H2 of the optical lens 100 is within the above range, the amount of light passing through the recess 115 and exiting the optical lens 110 is reduced. As the refractive index is increased, there is an effect of widening the beam angle of light.

A review of a backlight unit including such an optical module is as follows. 5 is a diagram illustrating a backlight unit including an optical module according to an exemplary embodiment. A backlight unit described below may be a direct type backlight unit.

Referring to FIG. 5 , an optical module 800 disposed on the cover bottom 300 is disposed. 5 shows a configuration in which one light source 150 and one optical lens 100 are disposed on the cover bottom 300, but the light source unit according to the present embodiment is not limited thereto, and the cover bottom 300 ) includes a configuration in which a plurality of light sources 150 and a plurality of optical lenses 100 are disposed on. A diffusion plate 400 and a plurality of optical sheets 410 are disposed on the optical module 800 .

Meanwhile, most of the light emitted from the optical module 800 according to the present embodiment may be emitted at a specific emission angle. Specifically, the emission angle θ of 50% or more of the light exiting the optical lens 100 according to the present embodiment satisfies Equation 1 below.

[Equation 1]

In Equation 1, the optical gap is the distance from the bottom surface of the circuit board 700 to the bottom surface of the diffusion plate 400. In Equation 1, the coverage (light spreading range) means a point having a brightness of 1/2 of the maximum brightness from a point having the maximum brightness of the light emitted from the optical lens 100 .

The light distribution of the light source unit including the optical module having the above-described light emission angle θ will be reviewed with reference to FIG. 6 as follows. 6 is a diagram illustrating light distribution of a light source unit including an optical module according to an exemplary embodiment.

Referring to FIG. 6 , among the light emitted from the optical module according to the present embodiment, most of the light emitted from the light source 150 is refracted at the light incident surface of the recess 115, and the first light of the optical lens 100 is refracted. Light is incident on the exit surface 130 . Then, the light incident on the first exit surface 130 is refracted and emitted to the outside of the optical lens 100 .

At this time, in the optical lens 100 according to the present embodiment, the beam angle of light is the widest in the region corresponding to the region in which the recess 115 has the first width and the optical lens 100 has the fourth width. can In addition, the recess 115 has a second width and the optical lens 100 has a third width from an area corresponding to the area where the recess 115 has the first width and the optical lens 100 has the fourth width. As the light moves to an area corresponding to the area having , the beam spread angle of the light may become narrower.

Further, in the optical lens 100 according to the present embodiment, an area where the recess 115 has a first width corresponds to an area where the optical lens 100 has a fourth width, and the recess 115 has a second width. Since the region having the width and the region having the third width of the optical lens 100 are arranged to correspond, most of the light emitted from the light source 150 is directed to the outside through the first light emitting surface of the optical lens 100 (for example, For example, in the direction of the diffusion plate), there is an effect that the beam angle of light can be further widened.

Specifically, the light emitted to the outside through the first light emitting surface 130 of the optical lens 100 is refracted at the boundary between the first light emitting surface 130 and the outside. Therefore, the beam angle of the light emitted to the outside through the first light emitting surface 130 can be widened. In addition, the light emitted to the outside through the second light emitting surface 135 of the optical lens 100 is refracted at the boundary between the second light emitting surface 135 and the outside. The beam angle of light emitted to the outside through the second light exit surface 135 may be narrowed.

This phenomenon is due to a difference in shape between the first light exit surface 130 and the second light exit surface 135 . In detail, since the first light emitting surface 130 is made of a curved surface, the surface area of the first light emitting surface 130 is widened, so the amount of light incident on the first light emitting surface 130 can be increased. In addition, The refraction of light also becomes large. That is, in the light source lens 100 according to the present embodiment, since most of the light is incident on the first light emitting surface 130 having a large surface area and a high refractive index and is emitted to the outside, the beam angle of light can be widened. Uniform luminance can be obtained over a wide area.

Next, a comparison of a path of light emitted from the light source unit according to the comparative example and a path of light emitted from the light source unit according to the present embodiment will be compared with reference to FIGS. 7 to 9 .

7 is a diagram illustrating a light source lens according to a comparative example. Referring to FIG. 7 , the light source lens 200 according to the comparative example includes a bottom surface, a recess 215 , a light incident surface 210 and a light exit surface 235 . Meanwhile, the recess 215 of the light source lens 200 according to the comparative example may have a first width L1 based on the first direction and a second width L2 based on the second direction. . Also, the third width L3 of the light source lens 200 based on the first direction may be equal to the fourth width L4 of the light source lens 200 based on the second direction.

That is, the recess 215 may have a circular shape on a plane, and the external shape of the light source lens 200 may also have a circular shape on a plane.

8 is a diagram illustrating a light path emitted from an optical module including a light source lens according to a comparative example. The light path shown in FIG. 8 is a light path emitted from the optical module including the light source lens of FIG. 7 .

Referring to FIG. 8 , light emitted from an optical module including a light source lens according to a comparative example may have an isotropic distribution. Specifically, the light emitted from the optical module including the light source lens according to the art may have the same light spreading area in all directions of up, down, left, and right.

Meanwhile, in the case of a backlight unit to which an optical module is applied, there is a problem in that the optical module cannot be symmetrically arranged due to its structure. Accordingly, it is difficult to focus the light because the degree of overlap with the light generated from the other lens is different in the left and right and top and bottom regions of the lens.

On the other hand, the light emitted from the optical module including the optical lens according to the present embodiment may have an anisotropic distribution different from the light emitted from the light source module including the optical lens according to the comparative example. These images are reviewed with reference to FIG. 9 as follows. 9 is an image showing the distribution of light emitted from the optical module according to the present embodiment.

Referring to FIG. 9 , light emitted from the optical module according to the present embodiment may have an anisotropic distribution. Specifically, the light emitted from the optical module according to the present embodiment shown in FIGS. 1 to 4 may have the same light distribution characteristics as the image shown in FIG. 9 . That is, when using the optical module according to the present embodiment, light spreading can be expanded in a specific direction.

In this way, the light spreading area of the light emitted from the optical module according to the present embodiment is expanded in a specific direction, thereby supplementing the disadvantages of the optical module including the conventional refractive optical lens. Specifically, in the case of an optical module including a conventional refractive optical lens, a light source and an optical lens cannot be disposed symmetrically up, down, left, and right. do. On the other hand, in the case of the optical module according to the present embodiment, the problem of the conventional refractive optical lens can be solved by having a light distribution characteristic in which the upper and lower light spreading range is wide compared to the left and right.

On the other hand, since the optical path difference remains due to the optical lenses according to the comparative example and the embodiment, the optical module including the optical lens according to the comparative example and the optical lens according to the present embodiment have optical paths on the circuit board, respectively. The shape in which the optical lens is disposed may be different. This is reviewed with reference to FIGS. 10 and 11 as follows.

FIG. 10 is a diagram illustrating a form in which an optical lens is disposed on a circuit board in an optical module including an optical lens according to a comparative example. FIG. 11 is a diagram showing a form in which an optical lens is disposed on a circuit board in an optical module including an optical lens according to an exemplary embodiment.

Here, the circuit board 700 in FIGS. 10 and 11 may have the same size. Also, a light source may be provided between the optical lens 200 and the circuit board 700 according to the comparative example, and a light source may also be provided between the optical lens 100 and the circuit board 700 according to the embodiment.

On the other hand, comparing the arrangement of the optical lenses 200 and 100 according to the comparative example and the embodiment through FIGS. 10 and 11, the optical lens 100 according to the embodiment on the circuit board 700 of the same area Compared to the optical lens 200 according to the comparative example, a smaller number may be disposed. This is because when the light emitted from the light source is emitted to the outside through the optical lens 100 according to the embodiment, the beam angle of light is wider than when the light is emitted to the outside through the optical lens 200 according to the comparative example. The number of optical lenses and light sources disposed on the circuit board 700 of the area may be reduced.

In addition, in FIG. 11, the number of optical lenses 100 disposed in the first direction on the circuit board 700 is greater than the number of optical lenses 100 disposed in the second direction. Even if the optical lens 100 is disposed, since the optical lens 100 according to the present embodiment has an anisotropic light distribution, a luminance non-uniformity phenomenon or a light out-of-focus phenomenon does not occur even in the second direction.

As described above, since the optical lens 100 according to the present embodiment has a structure showing an anisotropic light distribution, it can exhibit a light distribution characteristic with a wide upper and lower light spreading range compared to left and right. Therefore, the optical lens 100 according to the present embodiment has an effect of preventing non-uniformity of luminance and out-of-focus light even in an optical module having a structure in which the optical lenses 100 cannot be vertically and horizontally symmetrically arranged. there is

The features, structures, effects, etc. described in the foregoing embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment can be combined or modified with respect to other embodiments by those skilled in the art in the field to which the embodiments belong. Therefore, contents related to these combinations and variations should be construed as being included in the scope of the present invention.

In addition, although the embodiments have been described above, these are merely examples and do not limit the present invention, and those of ordinary skill in the field to which the present invention belongs can exemplify the above to the extent that does not deviate from the essential characteristics of the present embodiment. It will be seen that various variations and applications that have not been made are possible. For example, each component specifically shown in the embodiments can be modified and implemented. And differences related to these variations and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100: optical lens
110: light incident surface
115: recess
120: bottom surface
130: first light exit surface
135: second light exit surface
150: light source

Claims (12)

bottom side;
a recess that is convex from the bottom surface and has a first width based on a first direction when viewed in plan view is greater than a second width based on a second direction perpendicularly crossing the first direction; and
A light exit surface located on the opposite side of the bottom surface and having a third width based on the first direction on a plane that is shorter than a fourth width based on the second direction;
The bottom surface includes a surface inclined with respect to the first direction,
The light emitting surface includes a first light emitting surface located on the opposite side to the bottom surface and formed of a spherical surface and a second light emitting surface disposed around a lower circumference of the first light emitting surface and having a flat surface extending,
The first light exit surface is connected to the second light exit surface below the first light exit surface, the second light exit surface connects the first light exit surface and the bottom surface,
The first light exit surface includes a flat surface in a region corresponding to an upper portion of the recess,
The flat surface is a high point of the first light exit surface,
A high point of the first light exit surface overlaps the recess,
The region between the flat surface and the second light exit surface has a convex curved shape,
With respect to the optical axis, the emission angle of light emitted to the first light exit surface after refraction is greater than the incident angle before refraction, and the emission angle of light emitted to the second light exit surface with respect to the optical axis is smaller than the incident angle before refraction. and
The planar shape of the recess and the light exit surface is an elliptical shape,
The length from the surface of the recess to the outer diameter of the light exit surface is shortest in the first direction, and increases as it moves from the first direction to the second direction, and the outer diameter of the light exit surface from the surface of the recess The longest optical lens in the second direction.
According to claim 1,
Each of the first width and the third width based on the first direction is the maximum width of the recess and the light exit surface, and each of the second width and the fourth width based on the second direction is the maximum width of the recess. An optical lens that is the maximum width of the light exit surface.
According to claim 1,
An area of the recess having the first width and an area of the light exit surface having the fourth width are positioned to correspond to each other;
An area of the recess having the second width and an area of the light exit surface having the third width are positioned to correspond to each other.
According to claim 1,
The first width is the maximum width of the recess, and the fourth width is the maximum width of the optical lens.
According to claim 1,
The first width of the recess is 1.2 to 1.3 times the second width.
According to claim 1,
The fourth width of the light exit surface of the optical lens is 1.04 to 1.06 times the third width.
According to claim 1,
The maximum height of the optical lens is 1.05 to 1.3 times the maximum height of the recess.
According to claim 1,
A radius of curvature of the recess region having the second width is greater than a radius of curvature of the recess region having the first width.
delete According to claim 1,
The fourth width corresponds to the length of the major axis of the second light emitting surface on a plane, and the third width corresponds to the length of the minor axis of the second light emitting surface on a plane.
The optical lens according to any one of claims 1 to 8 and 10; and
a substrate disposed below the optical lens;
A light source module comprising a; light source disposed between the substrate and the optical lens.
The light source module of claim 11;
a cover bottom disposed on a rear surface of the light source module;
a diffusion plate disposed above the light source module; and
A backlight unit including a plurality of optical sheets disposed on the diffusion plate.

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