Patent ID: 12259124

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of various exemplary embodiments or implementations of the invention. As used herein “embodiments” and “implementations” are interchangeable words that are non-limiting examples of devices or methods employing one or more of the inventive concepts disclosed herein. It is apparent, however, that various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring various exemplary embodiments. Further, various exemplary embodiments may be different, but do not have to be exclusive. For example, specific shapes, configurations, and characteristics of an exemplary embodiment may be used or implemented in another exemplary embodiment without departing from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are to be understood as providing exemplary features of varying detail of some ways in which the inventive concepts may be implemented in practice. Therefore, unless otherwise specified, the features, components, modules, layers, films, panels, regions, and/or aspects, etc. (hereinafter individually or collectively referred to as “elements”), of the various embodiments may be otherwise combined, separated, interchanged, and/or rearranged without departing from the inventive concepts.

The use of cross-hatching and/or shading in the accompanying drawings is generally provided to clarify boundaries between adjacent elements. As such, neither the presence nor the absence of cross-hatching or shading conveys or indicates any preference or requirement for particular materials, material properties, dimensions, proportions, commonalities between illustrated elements, and/or any other characteristic, attribute, property, etc., of the elements, unless specified. Further, in the accompanying drawings, the size and relative sizes of elements may be exaggerated for clarity and/or descriptive purposes. When an exemplary embodiment may be implemented differently, a specific process order may be performed differently from the described order. For example, two consecutively described processes may be performed substantially at the same time or performed in an order opposite to the described order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it may be directly on, connected to, or coupled to the other element or layer or intervening elements or layers may be present. When, however, an element or layer is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element or layer, there are no intervening elements or layers present. To this end, the term “connected” may refer to physical, electrical, and/or fluid connection, with or without intervening elements. Further, the D1-axis, the D2-axis, and the D3-axis are not limited to three axes of a rectangular coordinate system, such as the x, y, and z-axes, and may be interpreted in a broader sense. For example, the D1-axis, the D2-axis, and the D3-axis may be perpendicular to one another, or may represent different directions that are not perpendicular to one another. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z, such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although the terms “first,” “second,” etc. may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another element. Thus, a first element discussed below could be termed a second element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,” “above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), and the like, may be used herein for descriptive purposes, and, thereby, to describe one elements relationship to another element(s) as illustrated in the drawings. Spatially relative terms are intended to encompass different orientations of an apparatus in use, operation, and/or manufacture in addition to the orientation depicted in the drawings. For example, if the apparatus in the drawings is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term “below” can encompass both an orientation of above and below. Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90 degrees or at other orientations), and, as such, the spatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, the singular forms, “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Moreover, the terms “comprises,” “comprising,” “includes,” and/or “including,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It is also noted that, as used herein, the terms “substantially,” “about,” and other similar terms, are used as terms of approximation and not as terms of degree, and, as such, are utilized to account for inherent deviations in measured, calculated, and/or provided values that would be recognized by one of ordinary skill in the art.

Various exemplary embodiments are described herein with reference to sectional and/or exploded illustrations that are schematic illustrations of idealized exemplary embodiments and/or intermediate structures. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, exemplary embodiments disclosed herein should not necessarily be construed as limited to the particular illustrated shapes of regions, but are to include deviations in shapes that result from, for instance, manufacturing. In this manner, regions illustrated in the drawings may be schematic in nature and the shapes of these regions may not reflect actual shapes of regions of a device and, as such, are not necessarily intended to be limiting.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense, unless expressly so defined herein.

Exemplary embodiments of the invention will be described in detail with reference to the accompanying drawings.

FIG.1is a perspective view of a light emitting module according to an exemplary embodiment, andFIG.2is a cross-sectional view along a major axis of a lens included in the light emitting module ofFIG.1according to an exemplary embodiment.FIG.3is a cross-sectional along a minor axis of the lens included in the light emitting module ofFIG.1according to an exemplary embodiment.

Referring toFIG.1, a light emitting module100according to an exemplary embodiment includes a light emitting device110and a lens120.

The light emitting device110is disposed on a substrate200. The substrate200may have an insulation property, and a conductive circuit may be formed on an upper region thereof. The substrate200may support the light emitting device110and the lens120. In an exemplary embodiment, the substrate200may be a printed circuit board, and may include a mounting groove on which the light emitting device110is mounted.

The light emitting device110may be disposed on the substrate200, and may be mounted in the mounting groove when the mounting groove is formed on the substrate200. The light emitting device110may be in the form of a package, in which a light emitting diode chip is mounted on a housing or a sub-mount, or in the form in which the light emitting diode chip is directly mounted on the substrate200.

When the light emitting device110is in the form of the light emitting diode chip, the light emitting diode chip may include a light emitting structure including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. In some exemplary embodiments, the light emitting diode chip may be a flip chip type, in which an n-type electrode electrically connected to the n-type semiconductor layer and a p-type electrode electrically connected to the p-type semiconductor layer are arranged in one side, or may be a vertical type, in which the n-type electrode and the p-type electrode are arranged in different sides. Each of the n-type semiconductor layer, the active layer, and the p-type semiconductor layer may include a III-V compound semiconductor, for example, a nitride semiconductor, such as (Al, Ga, In) N.

The n-type semiconductor layer may be a conductive semiconductor layer including an n-type impurity (e.g., Si), and the p-type semiconductor layer may be a conductive semiconductor layer including a p-type impurity (e.g., Mg). The active layer may be interposed between the n-type semiconductor layer and the p-type semiconductor layer, and may include a multiple quantum well structure (MQW). A composition ratio of the active layer may be determined to emit light having a desired peak wavelength. In the illustrated exemplary embodiment, the composition ratio of the light emitting diode chip may be determined to emit blue light or ultraviolet light to the outside.

The lens120is provided to spread light emitted from the light emitting device110, and is disposed to cover the light emitting device110. The lens120may have a light incident surface121aon which light emitted from the light emitting device110is incident, and a light exiting part123through which light is emitted to the outside from the lens120. In the illustrated exemplary embodiment, the lens120includes a light entering part121having a concave shape in a lower region thereof, and an inner surface of the light entering part121may be the light incident surface121a.

The light entering part121may be formed in the lower region of the lens120, and may be disposed at a center of the lens120as shown in the drawings. A shape of the light entering part121may be concave or a substantially half-elliptical shape as shown inFIGS.1to3. In the illustrated exemplary embodiment, the minor axis direction of the elliptical light entering part121is defined as an x-axis direction, and the major axis direction of light entering part121is defined as a y-axis direction.

The light incident surface121a, which is the inner surface of the light entering part121, may have a curved surface as a whole. The light incident surface121aand a lower surface125of the lens120may be connected to each other by the curved surface. However, the inventive concepts are not limited thereto, and in some exemplary embodiments, an upper most region of the light incident surface121amay include a flat surface, for example.

In the illustrated exemplary embodiment, the lower surface125of the lens120may have a planar shape, as shown in the drawings. However, the inventive concepts are not limited thereto, and in some exemplary embodiments, the lower surface125of the lens120may include an inclined surface. In this case, the inclined surface may be inclined upward from the light entering part121toward an outer surface of the lens120.

The light exiting part123forms an outer shape of the lens120with a surface through which the light incident on the lens120is emitted to the outside. A cross-sectional view of the light exiting part123along a major axis in the x-axis direction may have a substantially elliptical shape. In the illustrated exemplary embodiment, the minor axis direction of the elliptical light exiting part123is the y-axis direction, and the major axis direction of the light exiting part123is the x-axis direction. More particularly, the major axis of the light entering part121and the major axis of the light exiting part123are arranged perpendicular to each other.

The light entering part121having the elliptical shape may have a greater ratio of the major axis to the minor axis than that of the light exiting part123. More particularly, the elliptical shape of the light exiting part123may be closer to a circular shape than that of the light entering part121. Accordingly, greater amount of light emitted from the light emitting device110may be incident toward the major axis of the light exiting part123.

As such, in the cross-sectional view taken along the x-axis direction of the lens120as shown inFIG.2, the light exiting part123is disposed along the major axis direction, and the light entering part121is disposed along the minor axis direction. In the cross-sectional view taken along the y-axis direction of the lens120as shown inFIG.3, the light exiting part123is disposed along the minor axis direction, and the light entering part121is disposed along the major axis direction. As such, light incident on the lens120through the minor axis direction of the light entering part121has a relatively longer transmission distance within the lens120than light incident on the lens120through the major axis direction of the light entering part121.

The lens120may further include a flange127connecting the light exiting part123and the lower surface of the lens120. The flange127may be disposed along an outer periphery of the light exiting part123, and a longitudinal side surface of the flange127may be substantially perpendicular to the lower surface125of the lens120. In this case, a thickness of the flange127may vary depending on a location of a light emitting surface. In the illustrated exemplary embodiment, a thickness “t1” of the flange127located at the major axis of the light exiting part123may be relatively thicker than a thickness “t2” of the flange127located at the minor axis of the light exiting part123. The thickness of the flange127may be the thickest at the major axis of the light exiting part123and the thinnest at the minor axis of the light exiting part123. In an exemplary embodiment, a boundary127abetween the flange127and the light exiting part123may be formed as a curved line as shown inFIGS.1to3.

A plurality of legs129may be disposed on the lower surface125of the lens120. The legs129may be disposed around the light entering part121and may have a predetermined thickness, and may function as a mark for an alignment when the when the lens120is coupled to the substrate200.

The plurality of legs129may be disposed at a longer interval along the major axis of the light entering part121. For example, four legs129may be formed on the lens120according to an exemplary embodiment, two of which may be disposed at a first interval W1on one side of the light entering part121at the major axis, and the remaining two legs129may be disposed at a second interval W2on an opposite side to the one side of the light entering part121at the major axis. In this case, the first interval W1and the second interval W2may be substantially equal to each other. An interval between the two legs129disposed on the one side of the light entering part121and the two legs129disposed on the other side may be longer than the first and second intervals W1and W2.

FIG.4is a cross-sectional view along a major axis of the light emitting module ofFIG.1according to an exemplary embodiment.

Referring toFIG.4, the light emitting device110of the light emitting module100ofFIG.1according to an exemplary embodiment is disposed in the light entering part121of the lens120, as shown in the drawing. In the illustrated exemplary embodiment, the light emitting device110may be a flip chip type light emitting device110, and accordingly, the light emitting device110emits light upwards and sidewards from the light emitting device110.

Light emitted upwards from the light emitting device110may be emitted to the outside through the light exiting part123via the light entering part121of the lens120. A portion of the light emitted sidewards from the light emitting device110may be emitted to the outside through the light exiting part123via the light entering part121, but the light incident on the light entering part121may be emitted to the outside through the flange127as shown in the drawing. Accordingly, light emitted through the flange127may be emitted to the outside without being refracted by the lens120, thereby increasing the amount of light emitted from the side surface of the lens120.

In the illustrated exemplary embodiment, the thickness of the major axis of the flange127is different from that of the minor axis of the flange127. As such, an amount of light emitted to the major axis may be relatively larger than an amount of light emitted to the minor axis of the lens120. More particularly, as the thickness of the flange127is thicker, an amount of light exiting the lens120through the flange127without being refracted by then lens120may be increased. As such, the amount of light emitted to the major axis of the lens120, in which the relatively thicker flange127is formed, may be greater than that emitted to the minor axis of the lens120.

As such, the lens120according to the illustrated exemplary embodiment may spread light more in the major axis direction than in the minor axis direction.

FIG.5is a cross-sectional view along a minor axis of the light emitting module ofFIG.1according to an exemplary embodiment.

Referring toFIG.5, the lens120of the light emitting module100ofFIG.1according to an exemplary embodiment may be formed through injection. As such, a shape of a gate G for the injection mold may be formed in the flange127of the lens120. In this case, a thickness of the flange127at the minor axis may be determined by a thickness of the gate G, and in some exemplary embodiments, the flange127may be formed thicker than the gate G.

In the illustrated exemplary embodiment, the thickness of the flange127may be greater at the major axis than at the minor axis, and may be less than 4 mm. Further, the thickness of the flange127at the minor axis may be in a range of 0.3 mm to 1 mm.

FIG.6is a view of the light emitting module mounted on the substrate200according to an exemplary embodiment.

Referring toFIG.6, a plurality of light emitting modules100may be disposed on the substrate200. The substrate200may have a substantially elongated shape, such as a bar, having the longitudinal direction. The substrate200may include a conductive circuit to supply power to the light emitting device110mounted on an upper surface of the substrate200. The light emitting module may be formed by disposing lenses120to cover a plurality of light emitting devices110when the light emitting devices110are coupled to the conductive circuit of the substrate200.

As shown inFIG.6, the lens120may be disposed on the substrate200such that the major axis direction of the light entering part121coincides with the longitudinal direction of the substrate200. Accordingly, the major axis of the light exiting part123of the lens120may be arranged perpendicular to the longitudinal direction of the substrate200, and the lens120may be relatively protruding to an outer surface of the substrate200. Further, a width of the light entering part121of the lens120in the minor axis direction may be smaller than a width of the substrate200. The legs129of the lens120may be coupled to the substrate200, and thus, the lens120may be coupled to the substrate200.

FIG.7is a view of a backlight unit of a 32-inch display device equipped with the light emitting module according to an exemplary embodiment, andFIG.8is a view of a backlight unit of a 55-inch display device equipped with the light emitting module according to an exemplary embodiment.

Referring toFIG.7, a backlight unit300of the 32-inch display device according to an exemplary embodiment may include a backlight module310. The backlight module310may include a plurality of light emitting modules100arranged at regular intervals on the substrate200having a predetermined length.

In this case, one backlight module310may be installed in the 32-inch backlight unit300, and the backlight module310may be disposed at a center of the backlight unit300in the longitudinal direction of the backlight unit300. Accordingly, light emitted from the plurality of light emitting modules100may be emitted in a direction perpendicular to the longitudinal direction of the substrate200and irradiated onto an entire surface of the backlight unit300.

Referring toFIG.8, a backlight unit400of the 55-inch display device according to an exemplary embodiment may have three backlight modules310each arranged in a direction perpendicular to the longitudinal direction of the backlight unit400. The backlight module310, as shown in the drawing, includes the substrate200having an one-directional length and the plurality of light emitting modules100disposed on the substrate200. Accordingly, the backlight module310has the one-directional length as in the substrate200. The three backlight modules310disposed in the backlight unit400of the 55-inch display device may be disposed in a direction perpendicular to the longitudinal direction of the backlight module310.

Each of the backlight modules310may include the plurality of light emitting modules100on the single substrate200. Light emitted from each light emitting module100may be emitted with a light distribution characteristic having the direction perpendicular to the longitudinal direction of the substrate200, and thus, light may be irradiated onto an entire surface of the backlight unit400.

In this case, the number of the backlight modules310disposed and the number of the light emitting modules100disposed on the substrate200may be different depending on a size of the display device.

FIG.9is a cross-sectional view along a major axis of a lens included in a light emitting module according to another exemplary embodiment, andFIG.10is a plan view of the lens included in the light emitting module ofFIG.9according to an exemplary embodiment.

Referring toFIGS.9and10, a light emitting module500according to an exemplary embodiment includes a light emitting device510and a lens520. In the illustrated exemplary embodiment, the configuration of the light emitting device500is substantially the same as that shown inFIGS.1to3, and thus, repeated descriptions thereof and to some of the substantially similar features of the lens520will be omitted to avoid redundancy.

In the illustrated exemplary embodiment, the lens520includes a light entering part521, a light exiting part523, a flange527, and legs529. The configurations of the light entering part521, the light exiting part523, and the legs529are substantially the same as those described above with reference toFIGS.1to3. The flange527according to the illustrated exemplary embodiment may protrude to an outer surface of the lens520at the light exiting part523. More particularly, a width of the flange527may be relatively greater than a width of the light exiting part523of the lens520at the major axis (x-axis direction) as shown inFIG.9.

Moreover, as shown inFIG.10, the flange527may have a substantially circular shape in plan view. In particular, the light exiting part523of the lens520has a substantially elliptical shape, and the flange527has a substantially circular shape. Accordingly, a distance from an end of an outer surface of the flange527to an end of an outer surface of the light exiting part523may be different from each other at the major axis and the minor axis of the light exiting part523.

FIG.11is a graph illustrating a brightness of light emitted from the major axis of the light exiting part in the light emitting modules according to exemplary embodiments.FIG.12is a graph illustrating a brightness of light emitted from the minor axis of the light exiting part in the light emitting modules according to exemplary embodiments.

A size and a shape of the flange527of the lens520included in the light emitting module500ofFIG.12is different from those of the flange127of the lens120included in the light emitting module100ofFIG.1. Accordingly, the brightness of light emitted from the light emitting module500can be adjusted according to the size and shape of the flange527. The brightness of light emitted from the light emitting module500can be adjusted by the size and shape of the flange527since light emitted from the light emitting module500may be reflected at a bottom of the substrate200or the backlight unit.

More particularly, referring back toFIG.6, since the lens520is larger than the width of the substrate200, light may be emitted to the outside through the lower surface525of the lens520. Accordingly, if the size and shape of the flange527of the lens520are changed, an amount of light emitted through the lower surface525of the lens520may be changed.

As in the light emitting module ofFIG.9, when the size of the flange527is increased by 10% than that of the flange127ofFIG.1, the brightness of light emitted to the major axis direction with respect to the light exiting part of the lens520may be reduced by about 30% at the center. This is because the amount of light emitted through the lower surface525of the lens520, with the lower surface525being exposed to the outside of the substrate200, is greater than an amount of light reflected from the substrate200after being emitted through the lower surface125of the lens120of the light emitting module100.

Also, as shown inFIG.12, it can be seen that a center brightness of light emitted in the minor axis direction of the light exiting part of the lens520is reduced by about 30%.

FIG.13is a perspective view of a light emitting module according to an exemplary embodiment.FIG.14is a cross-sectional view along a major axis of a light exiting part of a lens included in the light emitting module ofFIG.13according to an exemplary embodiment.FIG.15is a cross-sectional view along a minor axis of the light exiting part of the lens included in the light emitting module ofFIG.13according to an exemplary embodiment.

Referring toFIG.13, a light emitting module600according to an exemplary embodiment includes a light emitting device610and a lens620.

The light emitting device610is disposed on the substrate200, and the light emitting device610according to the illustrated exemplary embodiment is substantially the same as that ofFIG.1, and thus, repeated descriptions of some of the elements thereof will be omitted.

The lens620is provided to spread light emitted from the light emitting device610, and is disposed to cover the light emitting device610. Referring toFIG.14, the lens620may have a light incident surface621a, on which light emitted from the light emitting device610is incident, and a light exiting part623through which light is emitted to the outside from the lens620. In the illustrated exemplary embodiment, the lens620includes a light entering part621having a substantially concave shape in a lower region thereof, and an inner surface of the light entering part621may be the light incident surface621a.

The light entering part621may be formed in the lower region of the lens620, and may be disposed at a center of the lens620as shown in the drawings. The light entering part621may have a substantially concave shape, as a bell, as shown inFIGS.13to15. In the illustrated exemplary embodiment, the light entering part621has a concave inner surface as the light incident surface621a, and the light incident surface621aincludes a light incident vertical surface621aaand a light incident inclined surface621ab. The light incident vertical surface621aais formed at an entrance of the light entering part621, which is substantially perpendicular to a horizontal surface and extends to a predetermined distance. The light incident inclined surface621abis formed to extend from the end of light incident vertical surface621aa.

The light incident inclined surface621abmay be disposed upwardly from the light incident vertical surface621aa, and may have a curved surface as a whole. Further, the light incident vertical surface621aaand a protruding surface631of the lens620may be extended. The protruding surface631of the lens620will be described later.

The entrance of the light entering part621according to the illustrated exemplary embodiment has a substantially elliptical shape, as shown inFIG.13, and may have a major axis and a minor axis. In this case, the major axis direction of light entering part621is defined as a y-axis direction, and the minor axis direction of the light entering part621is defined as an x-axis direction.

In the illustrated exemplary embodiment, a lower surface625of the lens620may have a substantially planar shape in general. The protruding surface (or protruding part)631may be formed on the lower surface625of the lens620around the entrance of the light entering part621. The protruding surface631, as shown in the drawing, may be formed to have a shape, in which a portion of a spherical shape is coupled to the lower surface625of the lens620. More particularly, the protruding surface631may have a partially spherical shape and coupled to the lower surface625of the lens620, and accordingly, as shown inFIGS.14and15, it may be formed in the shape protruding from the lower surface625of the lens620.

The light entering part621may be disposed at a center of the protruding surface131, and the light incidence vertical surface621aaof the light entering part621may be connected to the protruding surface631. The center of the protruding surface631and the center of the light entering part621may coincide with each other in a plan view of the lens620.

Moreover, a plurality of legs629is disposed on the lower surface625of the lens620, and the plurality of legs629may be disposed outside of the protruding surface631. In some exemplary embodiments, when the protruding surface631is formed on the lower surface625of the lens620, the legs629may be disposed outside of the protruding surface631so as not to interfere with the protruding surface631.

The plurality of legs629may be disposed at a longer interval along the major axis of the light entering part621. For example, four legs629may be formed on the lower surface of the lens620, two of which may be disposed at a first interval W1on one side of the light entering part621at the major axis, and the remaining two legs629may be disposed at a second interval W2on an opposite side to the one side of the light entering part621at the major axis. In this case, the first interval W1and the second interval W2may be substantially equal to each other. An interval between the two legs629disposed on the one side of the light entering part621and the two legs629disposed on the other side may be longer than the first and second intervals W1and W2.

The light exiting part623forms an outer shape of the lens620, and is a surface through which light incident on the lens620is emitted to the outside. A cross-sectional view of the light exiting part623may have a substantially elliptical shape having a major axis in the x-axis direction and a minor axis in the y-axis direction, and the light exiting part623may have a substantially convex shape having a predetermined curvature.

In the illustrated exemplary embodiment, the major axis of the light exiting part123and the major axis of the light entering part621may be arranged substantially perpendicular to each other.

Accordingly, light emitted from the light emitting device610may be relatively incident more toward the major axis of the light exiting part623.

Moreover, the lens620may further include a flange627connecting the light exiting part623and the lower surface620of the lens620. The flange627may be disposed along the outer periphery of the light exiting part623, and a longitudinal side surface of the flange627may be subsequently perpendicular to the lower surface625of the lens620. In this case, a thickness of the flange627may vary depending on a location of the light exiting part623, and the thickness of the flange627located at the major axis of the light exiting part623may be relatively thicker than the thickness of the flange627located at the minor axis of the light exiting part623. Accordingly, a boundary627abetween the flange627and the light exiting part623may be formed as a curved line.

In the illustrated exemplary embodiment, when a height of the light incident vertical surface621aaof the light entering part621and the thickness of the flange627are compared with each other, the height of the light incident vertical surface621aaof the light entering part621may be smaller than the thickness of the flange627. More particularly, the height of the light incident vertical surface621aamay be smaller than the thickness of the flange627at the minor axis of the light exiting part623, in which the thickness of the flange627is minimum.

FIG.16is a view for illustrating the light exiting part of the lens included in the light emitting module ofFIG.13according to an exemplary embodiment.

The curvature of the light exiting part623of the lens620included in the light emitting module600may be described with reference toFIG.16. According to an exemplary embodiment, the lens620may be designed by using a function used for designing an anamorphic lens, which is an optical lens for compressing or converting a wide shot scene to a standard size region on the surface of the lens.

More particularly, an asymmetric constant “B” may be added to design an aspherical lens in the x- and y-axes. That is, a coordinate value of the surface of the light exiting part623according to the illustrated exemplary embodiment may be expressed as a “z” value according to Equation 1 depending on x and y values.

𝓏=(cx⁢x2+cy⁢y2)1+(1-(1+kx)⁢cx2⁢x2-(1+ky)⁢cy2⁢y2+∑n=210A2⁢n[(1-B2⁢n)⁢x2+(1-B2⁢n)⁢y2]n[Equation⁢1]

An anamorphic surface shape provides a surface having a 20th order aspherical surface shape that is different each other in the Y-Z plane and the X-Z plane, but still has a symmetrical shape in each plane. In particular, the anamorphic surface shape is not an actual asymmetric surface form. The anamorphic surface may be entered in Equation 1 with curvature and conic constants and symmetric and asymmetric coefficients with respect to each plane.

Here, the constant A is the symmetry coefficient with respect to the aspherical shape in the Y-Z plane, and the constant B is the asymmetry coefficient, which is different in aspherical surface coefficients between the Y-X plane and the X-Z plane. If the curvature “c” is equal, and the Conic constant “k” is the same, and the constant B is all zero, Equation 1 can be reduced to a standard rotational symmetric polynomial aspherical surface.

As described above, an anamorphic aspherical surface provides a surface having a different 20th order aspheric surface shape in the Y-Z plane and the X-Z plane, but it may still be symmetrical in each plane. X-Y polynomials can be used for a full asymmetric surface.

This anamorphic aspheric surface may be entered with the curvature and Conic constants “k” and the symmetric and asymmetric surface coefficients with respect to each plane.

The constant “k” is the Conical constant, and k=−(e2). Here, the constant “k” value is related to a common conical shape as follows. If k=0, it is a sphere. If −1<k<0, it is an ellipse having the major axis in the z-axis, if k=−1, it is a parabola, if k<−1, it is a hyperbola, and if k>0, it is an oblate sphere.

Here, kxis the Conic constant in the x-axis, and kyis the Conic constant in the y-axis. And cxdenotes the curvature in the x-axis, and cydenotes the curvature in the y-axis.

For example, if cx=cy, kx=ky, and all B is zero, Equation 1 reduces to the standard rotational symmetric polynomial aspherical surface.

FIG.17is a view illustrating light emitted from the light emitting module ofFIG.13with a side view showing the major axis of the light emitting module according to an exemplary embodiment.

Referring toFIG.17, a path of light emitted in the major axis direction will be described. The light emitting device610according to an exemplary embodiment emits light both from an upper surface and a side surface of the light emitting device610. Accordingly, light emitted from the upper surface of the light emitting device610is incident on the lens620over the light incident surface621aof the lens620, and is emitted through the light exiting part623. Further, light incident on the light incident inclined surface621abof the lens620may be refracted and emitted through the light exiting part623. Moreover, light emitted to the side surface of the light emitting device610may be incident on the lens620through the light incident vertical surface621aaand may be directly emitted sidewards through the flange627of the lens620.

In addition, a portion of light emitted from the side surface of the light emitting device610may be reflected upward from the protruding surface631coupled to the lower surface625of the lens620, and may be emitted to the outside through the light exiting part623. Moreover, light emitted from the light emitting device610may be incident on the lens620through the light incident surface621a, and may be reflected without being emitted through the light exiting part623. At this time, a portion of the reflected light may be re-reflected from the protruding surface631and may be emitted again to the outside through the light exiting part623.

As described above, light emitted from the light emitting device610according to an exemplary embodiment may be reflected or re-reflected from the protruding surface631coupled to the lower surface of the lens620, and may be emitted through the light exiting part623of the lens620, thereby increasing the output of light emitted through the light exiting part623of the lens620.

Moreover, the portion of light emitted to the side surface of the light emitting device610may be incident on the lens620through the light incident vertical surface621aaand may be directly emitted through the flange627of the lens620. Accordingly, the output of light emitted from the side surface of the lens620may be increased. According to the present invention, since a distribution of light emitted from the light emitting module may have a near rectangular shape, there is an effect that uniform light may be emitted to the outside by combination with the distribution of light emitted from adjacent light emitting modules.

According to exemplary embodiments, since a distribution of light emitted from the light emitting module may have a near rectangular shape, uniform light may be emitted to the outside by combination with the distribution of light emitted from adjacent light emitting modules.

Although certain exemplary embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Accordingly, the inventive concepts are not limited to such embodiments, but rather to the broader scope of the appended claims and various obvious modifications and equivalent arrangements as would be apparent to a person of ordinary skill in the art.