Patent Description:
A light emitting diode is an inorganic semiconductor device that emits light through recombination of electrons and holes. In recent years, light emitting diodes are used in various fields including displays, vehicular lamps, general lighting, and the like. With various advantages, such as longer lifespan, lower power consumption, and higher response rate than existing light sources, the light emitting diodes have replaced the existing light sources.

A display apparatus or general lighting may employ several to dozens of such light emitting diodes. For the display apparatus including such a number of light emitting diodes, it is important to allow light emitted from the light emitting diodes to be uniformly emitted through a light emission surface of the display apparatus. If uniform emission of light through the light emission surface is not satisfied, interference of light emitted from the light emitting diodes can occur, causing generation of dark portions or bright portions.

<CIT> discloses an optical lens including a bottom surface, a concave recess provided in a center region of the bottom surface, a first light exit surface having a convexly curved surface on a side opposite to the bottom surface and the recess, and a second light exit surface between the bottom surface and the first light exit surface. A length in a first axis direction on the bottom surface is D1, and a length in a second axis direction perpendicular to the first axis direction is D2, a length in the first axis direction on the bottom of the recess is D3, and a length in the second axis direction on the bottom of the recess is D4, where D1 <D2 and D3>D4.

<CIT> discloses a light emitting module having an optical lens. The optical lens includes a recess upwardly convex at a central region of its bottom surface, a light input surface at a circumference of the recess, a first light output surface having a convexly curved surface at opposite sides of the bottom surface and the light input surface, and a second light output surface at a lower circumference of the first light output surface, wherein the bottom surface includes a first edge adjacent to the recess and a second edge adjacent to the second light output surface, a region of the bottom surface more adjacent to the first edge gradually approaches a first axis that is horizontal to a center of a bottom of the recess, and the first light output surface has a convex central region.

Embodiments of the present disclosure provide a light emitting module and a lens, which allow light emitted from each of light emitting devices to be uniformly emitted through a light emission surface of a display apparatus employing a plurality of light emitting devices.

In accordance with embodiments of the present disclosure, a light emitting module includes: a light emitting device; and a lens disposed above the light emitting device and dispersing light emitted from the light emitting device, wherein the lens includes a light incident portion through which light emitted from the light emitting device enters the lens and a light exit portion through which the light exits the lens, each of the light incident portion and the light exit portion having a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, and a lower surface of the lens includes a slanted surface downwardly slanted with respect to a horizontal surface thereof in an outward direction of the lens, wherein the lens has a protruding surface around the inlet of the light incident portion, protruding from the lower surface thereof to have a predetermined radius of curvature, and wherein a boundary between the slanted surface and the lower surface of the lens is a straight line.

The slanted surface may be disposed outside the protruding surface.

The light incident portion may have an upwardly concave part formed on the protruding surface of the lens and an inner surface of the concave part of the light incident portion may include a vertical light incident facet extending from the protruding surface of the lens and an oblique light incident facet extending from the vertical incident facet.

The slanted surface may be downwardly slanted with respect to the horizontal surface in the outward direction of the lens along the major axis of the light exit portion.

The light incident portion may be concavely formed in an upward direction on the lower surface of the lens, an inner surface of the light incident portion may be a light incident surface through which light emitted from the light emitting device enters the lens, and the light incident surface may include at least one protruding light incident facet protruding from a slanted surface of the light incident surface in an inward direction of the concave light incident portion.

The at least one protruding light incident facet may be disposed on the slanted surface of the light incident portion in a major axis direction thereof.

The protruding light incident facets disposed on the slanted surface of the light incident portion may be placed at opposite locations with respect to a horizontal direction of the lens.

The protruding light incident facet may be provided in plural and the plural protruding light incident facets may be disposed in a region of the slanted surface of the light incident portion having a larger area between a major axis direction and a minor axis direction of the light incident portion.

The plural protruding light incident facets disposed on the slanted surface of the light incident portion may include three protruding light incident facets disposed on one surface and one of the three protruding light incident facets may have a larger size than the other protruding light incident facets.

The lens may further include a plurality of legs formed on the lower surface of the lens to support the lens.

At least one of the legs may be formed with a leg protrusion protruding downwards from a lower surface thereof.

The leg protrusion may have a smaller width than the leg.

The lens may further include a flange connecting the light exit portion to the lower surface of the lens.

The flange may have a greater thickness in the major axis of the light exit portion than in the minor axis of the light exit portion.

In accordance with embodiments of the present disclosure, a lens includes: a light incident portion through which light emitted from a light emitting device enters the lens, the light incident portion being formed in a concave shape at a lower portion of the lens; and a light exit portion through which light having entered the lens through the light incident portion exits the lens, wherein each of the light incident portion and the light exit portion has a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, and a lower surface of the lens includes a slanted surface downwardly slanted with respect to a horizontal surface thereof in an outward direction of the lens, wherein the lens has a protruding surface around the inlet of the light incident portion, protruding from the lower surface thereof to have a predetermined radius of curvature, and wherein a boundary between the slanted surface and the lower surface of the lens is a straight line.

An inner surface of the light incident portion may be a light incident surface through which light emitted from the light emitting device enters the lens, and the light incident surface may include at least one protruding light incident facet protruding from a slanted surface of the light incident surface in an inward direction of the concave light incident portion.

In accordance with embodiments of the present disclosure, which do not fall under the scope of the claims, a light emitting module includes: a light emitting device; and a lens disposed above the light emitting device and dispersing light emitted from the light emitting device, wherein the lens includes a light incident portion through which light emitted from the light emitting device enters the lens and a light exit portion through which the light exits the lens, each of the light incident portion and the light exit portion having a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, the light incident portion is concavely formed in an upward direction on a lower surface of the lens, an inner surface of the light incident portion is a light incident surface through which light emitted from the light emitting device enters the lens, and the light incident surface includes a plurality of protruding light incident facets protruding from a slanted surface of the light incident surface in an inward direction of the concave light incident portion.

The plurality of protruding light incident facets may include at least one protruding light incident facet disposed in a region of the slanted surface of the light incident portion having a larger area between a major axis direction and a minor axis direction of the light incident portion and may be disposed on the slanted surface of the light incident surface.

The lens may further include: a flange disposed between the light exit surface and the lower surface of the lens; and at least one flange protrusion partially protruding from the flange in an outward direction of the lens.

A curved flange boundary may be formed between the flange and the light exit surface.

In accordance with embodiments of the present disclosure, which do not fall under the scope of the claims, a backlight unit may include at least one backlight module including: a substrate; a plurality of light emitting devices disposed on the substrate; and a plurality of lenses disposed on the light emitting devices, respectively, and dispersing light emitted from the light emitting devices, wherein each of the lenses includes a light incident portion through which light emitted from the light emitting device enters the lens and a light exit portion through which the light exits the lens, each of the light incident portion and the light exit portion having a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, and a lower surface of the lens includes a slanted surface downwardly slanted with respect to a horizontal surface thereof in an outward direction of the lens.

The substrate may have a predetermined length and the plurality of lenses may be disposed such that the major axis of the light exit portion is perpendicular to a longitudinal direction of the substrate.

The backlight module may further include a reflective sheet reflecting a faction of light discharged through the lens in an upward direction and secured to the backlight module by the lens.

The reflective sheet may be secured to the backlight module by being brought into contact with the slanted surface of the lens.

In accordance with embodiments of the present disclosure, which do not fall under the scope of the claims, a backlight unit may include: a substrate; a plurality of light emitting devices disposed on the substrate; and a plurality of lenses disposed on the light emitting devices, respectively, and dispersing light emitted from the light emitting devices, wherein each of the lenses includes a light incident portion through which light emitted from the light emitting device enters the lens and a light exit portion through which the light exits the lens, each of the light incident portion and the light exit portion having a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, the light incident portion is concavely formed in an upward direction on a lower surface of the lens, an inner surface of the light incident portion is a light incident surface through which light emitted from the light emitting device enters the lens, and the light incident surface includes a plurality of protruding light incident facets protruding from a slanted surface of the light incident surface in an inward direction of the concave light incident portion.

Each of the lenses may further include a plurality of legs formed on the lower surface of the lens to support the lens and at least one of the legs may be formed with a leg protrusion protruding downwards from a lower surface thereof.

The substrate may be formed with at least one substrate hole into which at least one of the legs is inserted.

Each of the lenses may further include: a flange disposed between the light exit surface and the lower surface of the lens; and at least one flange protrusion partially protruding from the flange in an outward direction of the lens.

In accordance with embodiments of the present disclosure, which do not fall under the scope of the claims, a display apparatus includes at least one backlight module including: a substrate; a plurality of light emitting devices disposed on the substrate; and a plurality of lenses disposed on the light emitting devices, respectively, and dispersing light emitted from the light emitting devices, wherein each of the lenses includes a light incident portion through which light emitted from the light emitting device enters the lens and a light exit portion through which the light exits the lens, each of the light incident portion and the light exit portion having a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, and a lower surface of the lens includes a slanted surface downwardly slanted with respect to a horizontal surface thereof in an outward direction of the lens.

In accordance with embodiments of the present disclosure, which do not fall under the scope of the claims, a display apparatus may include: a substrate; a plurality of light emitting devices disposed on the substrate; and a plurality of lenses disposed on the light emitting devices, respectively, and dispersing light emitted from the light emitting devices, wherein each of the lenses includes a light incident portion through which light emitted from the light emitting device enters the lens and a light exit portion through which the light exits the lens, each of the light incident portion and the light exit portion having a major axis and a minor axis in plan view, the major axis of the light incident portion being disposed at a right angle with respect to the major axis of the light exit portion, the light incident portion is concavely formed in an upward direction on a lower surface of the lens, an inner surface of the light incident portion is a light incident surface through which light emitted from the light emitting device enters the lens, and the light incident surface includes a plurality of protruding light incident facets protruding from a slanted surface of the light incident surface in an inward direction of the concave light incident portion.

According to embodiments of the present disclosure, the light emitting module has a substantially rectangular light distribution, thereby enabling uniform emission of light through combination with distribution of light emitted from adjacent light emitting modules.

In addition, a lens included in the light emitting module has a slanted surface on an outer lower surface thereof such that a separate reflective sheet can be disposed on the lower surface of the lens through the slanted surface, thereby enabling reduction in the number of processes by omitting a separate bonding member for securing the reflective sheet.

Light emitted through a side surface of the light emitting device can be reflected by a light exit portion or a flange of the lens instead of being discharged from the lens. The slanted surface formed on the lower surface of the lens reflects light reflected by the light exit portion or the flange of the lens to be discharged through the light exit portion or the flange of the lens, whereby light can be dispersed broadly when discharged from the lens.

Furthermore, vertical light incident facets are formed on the light incident portion of the lens to allow total reflection of light inside the light incident surface, to change a dark portion formed at the center of the lens into a bright portion, and to allow light emitted through the side surface of the light emitting device to be discharged through the flange of the lens, whereby the light can be dispersed broadly when discharged from the lens.

Furthermore, a plurality of protruding light incident facets is formed on the light incident portion of the lens to protrude in an inward direction of the light incident portion such that an optical path of light entering the lens can be adjusted based on the shape and location of the protruding light incident facets, thereby enabling more uniform discharge of light through the lens.

Furthermore, a plurality of flange protrusions protrudes outwards from the flange of the lens so as to have a greater protrusion length than a gate formed in manufacture of the lens, thereby minimizing generation of scratches on surfaces of other lenses due to the gate.

Furthermore, a leg protrusion is formed on a leg of the lens and the substrate is formed with a substrate hole which receives the leg protrusion when the leg protrusion is inserted into the substrate hole, thereby improving coupling strength between the lens and the substrate when the lens is mounted on the substrate.

<FIG> is a perspective view of a light emitting module according to a first embodiment of the present disclosure. <FIG> is a cross-sectional view of a lens of the light emitting module according to the first embodiment of the present disclosure, which is taken in a major axis direction of a light exit portion thereof, and <FIG> is a view of Region A in <FIG>. <FIG> is a view of Region B in <FIG>. <FIG> is a cross-sectional view of the lens of the light emitting module according to the first embodiment of the present disclosure, which is taken in a minor axis direction of the light exit portion thereof.

Referring to <FIG>, a light emitting module <NUM> according to the first embodiment includes a light emitting device <NUM> and a lens <NUM>.

The light emitting device <NUM> is mounted on a substrate <NUM>. Here, the substrate <NUM> has insulating properties and may be formed on an upper surface thereof with a conductive circuit. The substrate <NUM> serves to support the light emitting device <NUM> and the lens <NUM>. According to this embodiment, the substrate <NUM> may be a printed circuit board and may have a mounting recess on which the light emitting device <NUM> is mounted.

The light emitting device <NUM> is mounted on the substrate <NUM>. In the structure wherein the substrate <NUM> has the mounting recess, the light emitting device may be disposed in the mounting recess. The light emitting device <NUM> may be provided in the form of a package in which a light emitting diode chip is mounted on a housing or a sub-substrate, or may be provided in a structure wherein the light emitting diode chip is directly mounted on the substrate <NUM>.

When the light emitting device <NUM> is provided in the form of the light emitting diode chip, the light emitting diode chip may include a light emitting structure that includes an n-type semiconductor layer, an active layer, and a p-type semiconductor layer. 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 direction, or a vertical type in which the n-type electrode and the p-type electrode are arranged in different directions. Here, each of the n-type semiconductor layer, the active layer and the p-type semiconductor layer may include a III-V group-based compound semiconductor, for example, a nitride semiconductor, such as (Al, Ga, In)N.

The n-type semiconductor layer may be a conductive semiconductor layer containing n-type dopants (for example, Si) and the p-type semiconductor layer may be a conductive semiconductor layer containing p-type dopants (for example, Mg). The active layer may be interposed between the n-type semiconductor layer and the p-type semiconductor layer, and may have a multi-quantum well (MQW) structure. The composition of the active layer may be determined to emit light having a desired peak wavelength. In the light emitting diode chip according to this embodiment, the composition of the active layer may be determined to emit blue light or UV light.

The lens <NUM> is disposed to cover the light emitting device <NUM> and serves to distribute light emitted from the light emitting device <NUM>. To this end, the lens <NUM> has a light incident surface 121a through which light emitted from the light emitting device <NUM> enters the lens and a light exit portion <NUM> through which the light exits the lens <NUM>. According to this embodiment, the lens <NUM> includes a concave light incident portion <NUM> formed at a lower portion thereof and an inner surface of the light incident portion <NUM> may be the light incident surface 121a.

As shown in the drawings, the light incident portion <NUM> may be formed at the lower portion of the lens <NUM> and may be disposed at the center of the lens <NUM>. The light incident portion <NUM> may have a concave shape, for example, a bell shape, as shown in the drawings. In addition, the light incident portion <NUM> may have an elliptical cross-section having a major axis in the y-axis direction. In this embodiment, a minor axis direction of the light incident portion <NUM> having an elliptical cross-sectional shape will be defined as the x-axis direction and a major axis direction of the light incident portion <NUM> will be defined as the y-axis direction.

The light incident surface 121a corresponding to the inner surface of the light incident portion <NUM> may have a generally curved surface and may include a vertical light incident facet 121aa disposed at a lower portion of the light incident portion <NUM> and an oblique light incident facet 121ab disposed at an upper portion of the vertical light incident facet 121aa.

The vertical light incident facet 121aa is formed from an inlet of the light incident portion <NUM> to a predetermined height so as to be perpendicular to a horizontal surface of the lens. The oblique light incident facet 121ab is placed at the upper portion of the vertical light incident facet 121aa and may have a curved surface. The vertical light incident facet 121aa and a protruding surface <NUM> of the lens <NUM> may extend.

According to this embodiment, the oblique light incident facet 121ab may be formed with protruding light incident facets 121b. The protruding light incident facets 121b may be disposed on the oblique light incident facet 121ab and may be formed in a protrusion shape protruding in an inward direction of the light incident portion <NUM>. The protruding light incident facets 121b may have a substantially elliptical shape or may be formed in a curved protrusion shape.

As shown in <FIG>, a pair of protruding light incident facets 121b may be disposed at opposite locations with respect to the minor axis (x-direction) of the light incident portion <NUM>. As described above, since the light incident portion <NUM> is formed in an elliptical shape having a major axis in the y-axis direction and a minor axis in the x-axis direction, the light incident surface 121a formed in the y-axis direction may have a larger area than the light incident surface 121a formed in the x-axis direction. The protruding light incident facets 121b may be formed in a region of the light incident surface 121a having a relatively large area and may change an optical path of light that enters the lens <NUM> through the protruding light incident facets 121b thereof.

Although the pair of protruding light incident facets 121b is formed in this embodiment, the number of protruding light incident facets 121b on the oblique light incident facet 121ab may be increased. In addition, although the protruding light incident facets 121b are illustrated as being formed on the oblique light incident facet 121ab, the protruding light incident facets 121b may be formed on the vertical light incident facet 121aa, as needed. Alternatively, the protruding light incident facets 121b may be formed on both the vertical light incident facet 121aa and the oblique light incident facet 121ab.

A lower surface <NUM> of the lens <NUM> may have a substantially flat surface. The lower surface <NUM> of the lens <NUM> is formed with the protruding surface <NUM> around the inlet of the light incident portion <NUM>. As shown in <FIG>, the protruding surface <NUM> may be formed in a semispherical shape coupled to the lower surface <NUM> of the lens <NUM>. That is, the protruding surface <NUM> is formed by coupling a cut portion of a spherical shape to the lower surface <NUM> of the lens <NUM> and protrudes from the lower surface <NUM> of the lens <NUM>, as shown in <FIG> and <FIG>.

Here, the light incident portion <NUM> may be disposed at the center of the protruding surface and the vertical light incident facet 121aa of the light incident portion <NUM> may be connected to the protruding surface <NUM>. Although not shown in the drawings, the center of the protruding surface <NUM> may be coincident with the center of the light incident portion <NUM> in a plan view of the lens <NUM>.

Further, the lower surface <NUM> of the lens <NUM> is formed with a slanted surface <NUM>. Referring to <FIG>, the slanted surface <NUM> may be formed in an outer region of the lower surface <NUM> of the lens <NUM> in the major axis direction (x-direction) thereof and is downwardly slanted in an outward direction of the lens <NUM>. With this structure, a vertical distance between the slanted surface <NUM> and an imaginary lower surface 125a extending from the lower surface <NUM> of the lens <NUM> in the horizontal direction thereof increases in the outward direction of the lens <NUM>.

Although the slanted surface <NUM> is illustrated as a straight shape in <FIG> and <FIG>, the slanted surface <NUM> may have a convex shape or a concave shape, as needed.

Referring again to <FIG>, the slanted surface <NUM> is disposed in the outer region of the lower surface of the lens in the major axis direction of the lens <NUM> and a slanted surface boundary 133a is formed between the lower surface <NUM> of the lens <NUM> and the slanted surface <NUM>. The slanted surface boundary 133a is formed in a straight shape. Furthermore, the slanted surface boundary 133a may be formed in the minor axis direction (y-axis direction) of the light exit portion <NUM> of the lens <NUM>. Accordingly, the slanted surface <NUM> is present in the major axis direction of the light exit portion123 of the lens <NUM> in the cross-sectional view of <FIG>, whereas the slanted surface <NUM> is not present in the minor axis direction of the light exit portion <NUM> of the lens <NUM> in the cross-sectional view of <FIG>.

The slanted surface <NUM> is disposed outside the protruding surface <NUM>. The slanted surface <NUM> may partially overlap the protruding surface <NUM>, as needed.

According to this embodiment, the slanted surface <NUM> allows light reflected by an inner surface of the light exit portion123 of the lens <NUM> or by an inner surface of a flange <NUM> to be reflected again by the slanted surface <NUM> towards the light exit portion <NUM> or the flange <NUM>.

The light exit portion <NUM> corresponds to a surface through which light having entered the lens <NUM> exits the lens and defines an external appearance of the lens <NUM>. A cross-section of the light exit portion <NUM> may have an elliptical shape having a major axis in the x-axis direction or may have a combined shape of a curved line and a straight line. In this embodiment, in the light exit portion <NUM> having an elliptical cross-sectional shape, the minor axis direction of the light exit portion <NUM> corresponds to the y-axis direction and the major axis direction of the light exit portion <NUM> corresponds to the x-axis direction. That is, the major axis direction of the light incident portion <NUM> may be orthogonal to the major axis direction of the light exit portion <NUM>.

Here, the elliptical shape of the light incident portion <NUM> may have a greater ratio between major axis and minor axis than the elliptical shape of the light exit portion <NUM>. That is, the elliptical shape of the light exit portion <NUM> may have a more circular shape than the elliptical shape of the light incident portion <NUM>. With this structure, the light incident portion <NUM> allows light having entered the lens <NUM> through the light incident portion <NUM> of the lens <NUM> in the minor axis direction of the light incident portion <NUM> to spread more broadly than light having entered the lens <NUM> therethrough in the major axis direction of the light incident portion <NUM> when discharged from the lens <NUM>.

According to this embodiment, the lens <NUM> may further include the flange <NUM>, which connects the light exit portion <NUM> to the lower surface <NUM> of the lens <NUM>. The flange <NUM> may be disposed along an outer periphery of the light exit portion <NUM> and a longitudinal cross-section of the flange <NUM> may be perpendicular to the lower surface <NUM> of the lens <NUM>. Here, the flange <NUM> may have a thickness varying depending upon the location of the light exit portion <NUM>. According to this embodiment, thickness t1 of the flange <NUM> in the major axis direction of the light exit portion <NUM> may be greater than thickness t2 of the flange <NUM> in the minor axis direction of the light exit portion <NUM>. Further, the flange <NUM> may have the greatest thickness in the major axis direction of the light exit portion <NUM> and the smallest thickness in the minor axis direction of the light exit portion <NUM>. Here, a flange boundary 127a between the flange <NUM> and the light exit portion <NUM> may be formed in a curved shape, as shown in <FIG>. Obviously, the flange boundary 127a between the flange <NUM> and the light exit portion <NUM> of the lens <NUM> is not limited to the curved shape and may have a straight shape, as needed.

Further, a plurality of legs <NUM> may be disposed on the lower surface <NUM> of the lens <NUM>. The legs <NUM> may be disposed around the light incident portion <NUM>, may have a predetermined thickness, and may act as a reference for suitable mounting of the lens <NUM> when the lens <NUM> is coupled to the substrate <NUM>.

Here, the plurality of legs <NUM> may be linearly arranged in the major axis direction of the light incident portion <NUM>. That is, according to this embodiment, four legs <NUM> are disposed on the lower surface of the lens such that a pair of legs <NUM> is disposed at one side of the light incident portion <NUM> in the major axis direction thereof to have a first width W1 therebetween and the other pair of legs <NUM> is disposed at the other side of the light incident portion <NUM> in the major axis direction thereof to have a second width W2 therebetween. Here, the first pitch W1 may be the same as the second pitch W2. Further, a distance between the pair of legs <NUM> disposed at one side of the light incident portion <NUM> and the pair of legs <NUM> disposed at the other side of the light incident portion <NUM> may be greater than the first and second widths W1, W2.

Here, the plurality of legs <NUM> may be disposed outside the protruding surface <NUM> formed on the lower surface <NUM> of the lens <NUM> and inside the slanted surface <NUM> formed on the lower surface <NUM> of the lens <NUM>. That is, the plurality of legs <NUM> may be disposed between the protruding surface <NUM> and the slanted surface <NUM> to be placed on the flat lower surface <NUM>. Obviously, it should be understood that the legs <NUM> are not limited to these locations and may be disposed on the slanted surface <NUM>, as needed.

<FIG> and <FIG> are views comparing an optical path of light emitted from the light emitting module according to the first embodiment of the present disclosure with an optical path in the related art.

<FIG> shows an optical path of light in the lens <NUM> of the light emitting module <NUM>, in which the protruding light incident facet 121b is not formed on the light incident portion <NUM> of the lens <NUM>, when light is emitted from emitted from the light emitting device <NUM>, and <FIG> shows an optical path of light in the lens <NUM> of the light emitting module <NUM> according to this embodiment, in which the protruding light incident facet 121b is formed on the light incident portion <NUM> of the lens <NUM>, when light is emitted from the light emitting device <NUM>.

As shown in <FIG>, when light emitted from each of a central portion, a left portion and a right portion of the light emitting device <NUM> and having entered the lens <NUM> through the light incident surface 121a is discharged from the lens <NUM> through the light exit portion123, the light emitted from one portion of the light emitting device <NUM> may be separated from the light emitted from the other portions thereof.

In the lens <NUM> including the protruding light incident facets 121b on the light incident surface 121a, light may enter the lens <NUM> along different optical paths, as shown in <FIG>, whereby distribution of light emitted from the lens <NUM> through the light exit portion123 of the lens <NUM> can be changed. Accordingly, as described above, the structure wherein the protruding light incident facets 121b are formed on the light incident surface 121a of the lens <NUM> can minimize leaning of light emitted from the lens <NUM> toward a particular location and can change the optical path of light such that the light can be evenly distributed. Further, it is possible to minimize reflection of light emitted from the light emitting device <NUM> instead of entering the lens <NUM> through the light incident surface 121a.

<FIG> are views of modifications of the light incident portion of the lens of the light emitting module according to the first embodiment of the present disclosure.

In this embodiment, the light incident portion <NUM> of the lens <NUM> of the light emitting module <NUM> may be modified as shown in <FIG>.

Referring to <FIG>, the oblique light incident facet 121ab may be connected to an upper portion of the vertical light incident facet 121aa. Here, the oblique light incident facet 121ab may extend from an upper end of the vertical light incident facet 121aa.

Referring to <FIG>, the vertical light incident facet 121aa may have a greater width than the oblique light incident facet 121ab. That is, the vertical light incident facet 121aa may extend from the inlet of the light incident portion <NUM> and the oblique light incident facet 121ab may be formed farther inside than the vertical light incident facet 121aa to have a step on the light incident portion <NUM>. With this structure, when entering the lens through the light incident portion <NUM>, light may enter the lens <NUM> through the step formed between the vertical light incident facet 121aa and the oblique light incident facet 121ab.

Further, referring to <FIG>, a step may be formed on the vertical light incident facet 121aa. That is, a lower portion of the vertical light incident facet 121aa may be formed to a predetermined height from the inlet of the light incident portion <NUM> and an upper portion of the vertical light incident facet 121aa may be further formed from an upper side of the lower portion of the vertical light incident facet 121aa to have a step on the light incident portion <NUM>. The oblique light incident facet 121ab may be formed on an upper surface of the upper portion of the vertical light incident facet 121aa. In this way, the vertical light incident facet 121aa may be composed of two portions constituting a step therebetween to change the optical path of light entering the lens <NUM>.

As such, the optical path of light entering the lens <NUM> may be changed through modification of the light incident surface, thereby preventing generation of dark portions or bright portions in some zones through change of distribution of light discharged through the light exit portion123 of the lens <NUM>.

<FIG> is a perspective view illustrating a coupling relationship between the light emitting module according to the first embodiment of the present disclosure and a reflective sheet and <FIG> is a sectional view of the lens taken in the major axis direction of the light exit portion thereof, illustrating the coupling relationship between the light emitting module according to the first embodiment of the present disclosure and the reflective sheet.

According to this embodiment, a reflective sheet <NUM> may be coupled to a lower side of the light emitting module <NUM>. The reflective sheet <NUM> may be disposed under the light emitting module <NUM> to reflect light emitted from the light emitting module <NUM> and reaching the reflective sheet <NUM> in an upward direction. In the related art, the reflective sheet <NUM> disposed under the light emitting module <NUM> is secured to a backlight unit <NUM>, to which the substrate <NUM> is secured, by a bonding agent or a bonding sheet. According to this embodiment, the reflective sheet <NUM> may be secured to the backlight unit <NUM> using the lens <NUM> instead of using the bonding agent or the bonding sheet.

As described above, the lens <NUM> of the light emitting module <NUM> according to this embodiment has the slanted surface <NUM> downwardly slanted on the lower surface <NUM> thereof in the outward direction of the lower surface <NUM> and the reflective sheet <NUM> disposed under the light emitting module <NUM> may be secured to the backlight unit using the downwardly slanted surface <NUM> of the lens <NUM>.

As shown in <FIG>, the reflective sheet <NUM> may be formed with a positioning hole H at a location where the light emitting module <NUM> is placed. With this structure, the reflective sheet <NUM> is disposed under the lens <NUM> of the light emitting module <NUM> while being placed above the substrate <NUM>. Here, the positioning hole H formed in the reflective sheet <NUM> may have a smaller size than the lens <NUM> included in the light emitting module <NUM>.

In the structure wherein the positioning hole H of the reflective sheet <NUM> has a smaller size than the lens <NUM>, the reflective sheet <NUM> may be compressed by the lens <NUM> to be secured to a backlight unit <NUM> without using a bonding agent or a bonding sheet. Here, a portion of the slanted surface <NUM> of the lens <NUM> may be brought into contact with the reflective sheet to secure the reflective sheet thereto.

<FIG> is a view of a backlight module including the light emitting module according to the first embodiment of the present disclosure mounted on a substrate and <FIG> is a view of a backlight module of a <NUM>-inch display apparatus including the light emitting module according to the first embodiment of the present disclosure.

Referring to <FIG>, a backlight module <NUM> includes a substrate <NUM> and a plurality of light emitting modules <NUM>, which may be disposed on the substrate <NUM>. The substrate <NUM> may have a bar shape extending in the longitudinal direction thereof and may be formed with a conductive circuit to supply power to light emitting devices <NUM> mounted on an upper surface thereof. With the plurality of light emitting devices <NUM> connected to the conductive circuit of the substrate <NUM>, the lens <NUM> is disposed to cover the plurality of light emitting devices <NUM>, thereby forming the light emitting module <NUM>.

As shown in <FIG>, the lens <NUM> may be disposed on the substrate <NUM> such that the major axis direction of the light incident portion <NUM> is coincident with the longitudinal direction of the substrate <NUM>. In this structure, the major axis of the light exit portion123 of the lens <NUM> may be perpendicular to the longitudinal direction of the substrate <NUM> and the lens <NUM> may protrude outside the substrate <NUM>. In addition, the light incident portion <NUM> of the lens <NUM> in the minor axis direction may have a smaller width than the substrate <NUM>. Further, the legs <NUM> of the lens <NUM> may be coupled to the substrate <NUM> such that the lens <NUM> can be coupled to the substrate <NUM>.

Referring to <FIG>, a backlight unit <NUM> of the <NUM>-inch display apparatus may include the backlight module <NUM>. The backlight module <NUM> may include a plurality of light emitting modules <NUM> arranged at constant intervals on the substrate <NUM> having a predetermined length.

The backlight unit <NUM> may be provided with one backlight module <NUM>. The backlight module <NUM> may be disposed at the center of the backlight unit <NUM> in the longitudinal direction of the backlight unit <NUM>. In this structure, light emitted from the plurality of light emitting modules <NUM> travels in a perpendicular direction with respect to the longitudinal direction of the substrate <NUM> such that a front side of the backlight unit <NUM> can be illuminated with the light.

Although the <NUM>-inch display apparatus is illustrated by way of example in this embodiment, other display apparatuses having a larger size may employ the backlight module <NUM>. When a display apparatus employs a plurality of backlight modules <NUM>, the backlight modules <NUM> may be disposed in a perpendicular direction with respect to the longitudinal direction of the backlight unit <NUM>. The plurality of backlight modules <NUM> may be arranged at constant intervals.

<FIG> and <FIG> are views comparing a backlight unit of a <NUM>-inch display apparatus including typical light emitting modules with a backlight unit of a <NUM>-inch display apparatus including the light emitting modules according to the first embodiment of the present disclosure.

Referring to <FIG>, in a backlight unit <NUM> of a <NUM>-inch display apparatus provided with typical light emitting modules <NUM>, <NUM> backlight modules <NUM> are arranged in <NUM> columns. Here, the ten backlight modules <NUM> are disposed in the longitudinal direction of the backlight unit such that two backlight modules <NUM> are arranged in each column.

Further, each of the backlight modules <NUM> includes one substrate <NUM> and five light emitting modules <NUM>, each of which includes a circular lens. In this structure, the front side of the backlight unit <NUM> may be illuminated with light emitted from each of the backlight modules <NUM>.

On the other hand, referring to <FIG>, in a backlight unit <NUM> of a <NUM>-inch display apparatus provided with the light emitting modules <NUM> according to this embodiment, three backlight modules <NUM> are disposed in the perpendicular direction with respect to the longitudinal direction of the backlight unit <NUM>. As shown in the drawings, each of the backlight modules <NUM> includes a substrate <NUM> extending in one direction and a plurality of light emitting modules <NUM> disposed on the substrate <NUM>. With this structure, the backlight module <NUM> also extends in one direction like the substrate <NUM>. On the backlight unit <NUM> of the <NUM>-inch display apparatus, the three backlight modules <NUM> may be arranged in the perpendicular direction with respect to the longitudinal direction of the backlight unit <NUM>.

In each of the backlight modules <NUM>, light emitted from the plurality of light emitting modules <NUM> on one substrate <NUM> travels in the perpendicular direction with respect to the longitudinal direction of the substrate <NUM> such that the front side of the backlight unit <NUM> can be illuminated with the light.

With the backlight modules <NUM> according to this embodiment, the backlight unit <NUM> can achieve significant reduction in the number of light emitting modules <NUM> thereon, as compared with the backlight unit including the typical backlight modules.

According to the size of the display apparatus, the number of backlight modules <NUM> disposed on each of the backlight units <NUM>, <NUM> and the number of light emitting modules <NUM> disposed on the substrate <NUM> may be changed.

<FIG> is a perspective view of a light emitting module according to a second embodiment of the present disclosure, which does not fall under the scope of the claims, and <FIG> is a plan view of a lens of the light emitting module according to the second embodiment of the present disclosure. <FIG> is a side view of the lens of the light emitting module according to the second embodiment of the present disclosure taken in a minor axis direction of a light exit portion of the lens and <FIG> is a side view of the lens of the light emitting module according to the second embodiment of the present disclosure taken in a major axis direction of the light exit portion of the lens.

Referring to <FIG>, the light emitting module <NUM> according to the second embodiment includes a light emitting device <NUM> and a lens <NUM>. In description of the light emitting module <NUM> according to the second embodiment, the same components as those of the first embodiment will be omitted.

In this embodiment, the lens <NUM> is disposed to cover the light emitting device <NUM> and serves to distribute light emitted from the light emitting device <NUM>. To this end, the lens <NUM> may include a light incident portion <NUM> through which light emitted from the light emitting device <NUM> enters the lens <NUM> and a light exit portion <NUM> through which the light exits the lens <NUM>.

As shown in the drawings, the light incident portion <NUM> may be formed at a lower portion of the lens <NUM> and may be disposed at the center of the lens <NUM>. The light incident portion <NUM> may have a concave shape, for example, a bell shape. In addition, the light incident portion <NUM> may have an elliptical cross-section having a major axis in the y-axis direction and a minor axis in the x-axis direction.

A light incident surface 121a corresponding to an inner surface of the light incident portion <NUM> acts as a surface through which light enters the lens <NUM>, and may include a vertical light incident facet 121aa disposed at a lower portion of the light incident portion <NUM> and an oblique light incident facet 121ab disposed at an upper portion of the vertical light incident facet 121aa.

Referring to <FIG>, the oblique light incident facet 121ab may be formed with protruding light incident facets 121b. According to this embodiment, the oblique light incident facet 121ab is formed with six protruding light incident facets 121b, in which three protruding light incident facets 121b are disposed on each of relatively large areas of the oblique light incident facet 121ab. The protruding light incident facets 121b may protrude in the inward direction of the light incident portion <NUM> and may have a substantially elliptical shape.

In this embodiment, two groups of three protruding light incident facets 121b are formed on the oblique light incident facet 121ab in the major axis direction thereof, in which the three protruding light incident facets 121b disposed on one surface of the oblique light incident facet 121ab may be linearly arranged. Among these linearly-arranged protruding light incident facets 121b, the protruding light incident facet 121b disposed at the center may have a large size than the protruding light incident facets 121b disposed at both sides thereof.

As in the first embodiment, a flange boundary 127a according to this embodiment has a curved shape. Referring to <FIG>, a distance between the flange boundary 127a and the lower surface <NUM> is relatively great in the major axis direction of the light incident portion <NUM> (in the minor axis direction of the light exit portion <NUM> of the lens <NUM>, the y-axis direction), and referring to <FIG>, the distance between the flange boundary 127a and the lower surface <NUM> is relatively small in the minor axis direction of the light incident portion <NUM> (in the major axis direction of the light exit portion <NUM> of the lens <NUM>, the x-axis direction).

As such, with the flange boundary 127a formed in a curved shape, the protruding light incident facets 121b may be placed below the flange boundary 127a in the major axis direction of the light incident portion <NUM> (in the minor axis direction of the light exit portion <NUM> of the lens <NUM>, the y-axis direction) and above the flange boundary 127a in the minor axis direction of the light incident portion <NUM> (in the major axis direction of the light exit portion <NUM> of the lens <NUM>, the x-axis direction).

Further, according to this embodiment, a plurality of legs <NUM> may be linearly arranged in the major axis direction of the light incident portion <NUM> to be closer to the outer periphery of the lens than the legs of the lens according to the first embodiment. In addition, a flange protrusion 127b may protrude outwards from the flange <NUM> to be placed near each of the legs <NUM>. Although the flange protrusions 127b are illustrated as being placed near the legs <NUM>, it should be understood that other implementations are possible and the flange protrusions may be disposed irrespective of the locations the legs <NUM>.

The flange protrusions 127b may protrude outwards from the flange <NUM> and may be formed in a circular shape partially protruding therefrom, as shown in <FIG> and <FIG>. Further, referring to <FIG>, an upper surface of the flange protrusion 127b may be disposed along the flange boundary 127a. Accordingly, the upper surface of the flange protrusions 127b may be formed in a curved shape.

In this embodiment, four flange protrusions 127b may be provided, with a gate G disposed between two flange protrusions 127b. The gate G may be formed in the course of injection molding of the lens <NUM> according to this embodiment. The gate G may protrude outwards from the flange <NUM>. Here, a protruding length of the flange protrusions 127b protruding from the flange <NUM> may be greater than a protruding length of the gate G protruding from the flange <NUM> between the two flange protrusions 127b.

Here, when the plurality of lenses <NUM> is stored in a mixed state or in a process of mounting the lenses <NUM> on the substrate <NUM>, the surfaces of the lenses <NUM> (for example, the light exit surface thereof) may be scratched by the gate G, which may have a sharp distal end. However, according to this embodiment, the flange protrusions 127b protrude a greater length from the flange than the gate G, thereby preventing the surface of the lens <NUM> (for example, the light exit surface thereof) from being scratched by the gate G.

<FIG> is a view illustrating an optical path of light emitted from the light emitting module according to the second embodiment of the present disclosure.

Light emitted from the light emitting device <NUM> through the protruding light incident facet 121b may enter the lens <NUM>, as shown in <FIG>. In addition, as shown in <FIG>, the light may be discharged from the lens through the light exit portion <NUM>. In this embodiment, the flange protrusions 127b may be disposed on the lens <NUM>, as shown in <FIG>, such that light is not affected by the flange protrusions 127b when the light having entered the lens <NUM> through the protruding light incident facets 121b of the light incident portion <NUM> is discharged through the light exit surface of the lens <NUM>.

That is, according to this embodiment, the lens <NUM> has an optical path formed to allow light emitted from the light emitting device <NUM> to be concentrated in the minor axis direction (x-axis direction) of the light exit portion <NUM> after passing through the lens <NUM>. Here, the light incident portion <NUM> is formed with the plurality of protruding light incident facets 121b, thereby enabling relative diversification of the optical path through which light is concentrated while preventing light from being concentrated on a particular location or from failing to reach a certain location. In addition, the flange protrusions 127b are formed to be deviated from the optical path of light discharged through the lens <NUM>, thereby preventing the light from being concentrated on a particular location by the flange protrusions 127b.

<FIG> is a perspective view of a light emitting module according to a third embodiment of the present disclosure, which does not fall under the scope of the claims, and <FIG> is a side view of the light emitting module according to the third embodiment of the present disclosure.

Referring to <FIG> and <FIG>, the light emitting module <NUM> according to the third embodiment includes a light emitting device <NUM> and a lens <NUM>. In description of the light emitting module <NUM> according to the third embodiment, the same components as those of the first and second embodiments will be omitted.

According to this embodiment, the lens <NUM> may be formed with a plurality of legs <NUM> and leg protrusions 129a may be formed on some or all of the legs <NUM>. The leg protrusion 129a may protrude downwards from a lower surface of the leg <NUM> and may have a smaller diameter than the leg <NUM>. According to this embodiment, the legs <NUM> may have a circular shape in plan view and the leg protrusions 129a may have a circular shape in plan view. However, it should be understood that other implementations are possible and the legs and the leg protrusions may have various shapes, as needed.

Further, the substrate <NUM> may be formed with substrate holes <NUM> at locations corresponding to the leg protrusions 129a on the legs <NUM> of the lens <NUM>, which is mounted on the substrate <NUM>. The substrate hole <NUM> may be formed through the substrate <NUM> and may have a shape corresponding to the shape of the leg protrusion 129a to receive the leg protrusion 129a therein when the leg protrusion 129a is inserted into the substrate hole <NUM>.

As a result, as shown in <FIG>, the lens <NUM> may be mounted on the substrate <NUM>, with the leg protrusions 129a inserted into the substrate holes <NUM>. Here, as the leg protrusions 129a protrude downwards from the lower surfaces of the legs <NUM>, a portion of the lower surface of the leg <NUM> outside the leg protrusion 129a on the lower surface of the leg <NUM> may adjoin an upper surface of the substrate <NUM>. In addition, the lower surface of the leg <NUM> not formed with the leg protrusion 129a may adjoin the upper surface of the substrate <NUM>.

In this way, with the leg protrusions 129a inserted into the substrate holes <NUM>, the lens <NUM> is mounted on the substrate <NUM> and the legs <NUM> of the lens <NUM> are bonded to the substrate <NUM>, thereby improving bonding strength between the lens <NUM> and the substrate <NUM>.

Further, the light emitting modules <NUM> according to the first to third embodiments may be manufactured according to each of these embodiments or in the form of a combination of these embodiments.

Although some embodiments have been described herein with reference to the accompanying drawings, it should be understood that these embodiments are provided for illustration only and are not to be construed in any way as limiting the present disclosure. Therefore, it should be understood that the scope of the present disclosure should be defined by the appended claims.

Claim 1:
A light emitting module (<NUM>) comprising:
a light emitting device (<NUM>); and
a lens (<NUM>) disposed above the light emitting device (<NUM>) and dispersing light emitted from the light emitting device (<NUM>),
wherein the lens (<NUM>) comprises a light incident portion (<NUM>) through which light emitted from the light emitting device (<NUM>) enters the lens (<NUM>) and a light exit portion (<NUM>) through which the light exits the lens (<NUM>),
each of the light incident portion (<NUM>) and the light exit portion (<NUM>) having a major axis and a minor axis in plan view,
the major axis of the light incident portion (<NUM>) being disposed at a right angle with respect to the major axis of the light exit portion (<NUM>); and
a lower surface (<NUM>) of the lens comprises a slanted surface (<NUM>) downwardly slanted with respect to a horizontal surface thereof in an outward direction of the lens (<NUM>), characterized in that:
the lens (<NUM>) has a protruding surface (<NUM>) around the inlet of the light incident portion (<NUM>), protruding from the lower surface (<NUM>) thereof to have a predetermined radius of curvature, and
wherein a boundary (133a) between the slanted surface (<NUM>) and the lower surface (<NUM>) of the lens (<NUM>) is a straight line.