KR20080044048A - Optical component and back light unit using the same - Google Patents

Abstract

An optical component and a backlight unit having the same are provided to obtain a uniform light distribution of the optical component by attaching two media with different refractive indexes to each other at predetermined slopes. A light emitting diode includes a light emitting chip(140) and a light transmissive material(180). The light transmissive material encloses the light emitting chip. An external source connecting member applies an external voltage to the light emitting chip. The light emitting chip is mounted on a base member. The light transmissive material protects the light emitting chip and emits the light from the light emitting chip to the outside.

Description

OPTICAL COMPONENT AND BACK LIGHT UNIT USING THE SAME}

1 is a view for explaining total reflection.

2 is a view for explaining the path of light propagation according to the medium and its refractive index.

3 is a graph of light extraction efficiency according to the medium and its refractive index.

4 is a graph of light extraction efficiency according to the angle of the media interface to light.

5 is a schematic cross-sectional view of a light emitting diode with a lens that is a light transmitting body according to a first embodiment of the present invention.

6 is a view for explaining a light movement path of the light emitting diode according to the present invention.

7 is a schematic cross-sectional view of a prism sheet that is a light transmitting body according to a second embodiment of the present invention.

8 is a schematic exploded perspective view of a backlight unit provided with a light transmitting body according to the present invention.

<Explanation of symbols for the main parts of the drawings>

n ₁ : first medium n ₂ : second medium

n ₃ : third medium n ₄ : fourth medium

100: housing 120: lead

140: light emitting chip 160: wiring

180: light transmitting member 181: prism sheet

200: storage member 220: reflective sheet

240: light emitting diode 280: diffusion sheet

300: optical sheet

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to optical components, and more particularly to optical components in which media having different refractive indices have a predetermined angle with respect to a light source.

In general, the liquid crystal display (LCD) has been expanding its application range due to features such as light weight, thinness, low power driving, full color, and high resolution. Currently, liquid crystal displays are used in computers, notebooks, PDAs, telephones, TVs, and audio / video devices. Such a liquid crystal display displays a desired image on a liquid crystal display panel in which light transmittance is adjusted according to image signals applied to a plurality of control switches arranged in a matrix form.

The liquid crystal display device includes a backlight unit provided under the liquid crystal display panel and the liquid crystal display panel to supply light to the liquid crystal display panel. In this case, the backlight unit according to the prior art uses a point light source, a line light source, a surface light source as its light source, and the point light source of the light source as described above uses a light emitting diode.

Recently, research on a backlight unit using a light emitting diode that produces a white (W) light source by mixing red (R), green (G), and blue (B) as a backlight using the light source as described above has been actively conducted.

However, a plurality of light emitting diodes having 0 dimensions compared to one or two dimension light sources such as a cold cathode fluorescent lamp (CCFL) or a surface light source (FFL) should be placed in the backlight unit. In addition, the light emitting diodes located in the backlight unit must mix desired white light through color coupling, and various diffusion optical components and lenses have been developed for this purpose.

Representative examples of the above-described diffusing optical parts and lenses include side emitting lenses used for side light emitting diodes and top emitting lenses used for top emitting light emitting diodes. .

In this case, the side light emitting diode using the side light emitting lens should reflect the light emitted from the light emitting chip from the bottom surface, that is, from the reflective sheet to the top, whereby primary light loss occurs. In addition, as described above, the light reflected upwards passes through the inside of the optical sheet, causing secondary light loss. In addition, since the pattern formed on the outside of the optical sheet serves to block the path of the light emitted upward, the third light loss occurs.

In addition, the top light emitting diode using the top light emitting lens has a low light loss, but the lens should be designed such that the light emitted from the light emitting chip has a uniform light distribution in order to obtain uniform white light. However, the top light emitting diode using the top light emitting lens according to the prior art has a limitation in that the light emitted from the light emitting chip has a uniform light distribution.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an optical component with a minimum light loss and a uniform light distribution.

In order to achieve the above object, the present invention provides an optical component comprising a plurality of media through which light is transmitted and having different refractive indices, wherein an interface between the media having different refractive indices has a predetermined slope with respect to a light source. .

In this case, the different media may include a first medium and a second medium, and the first medium may have a lower refractive index than the second medium. In addition, the predetermined slope is 15 to 45 degrees is the best light extraction efficiency.

In addition, an air layer may be further included between the first medium and the second medium. In this case, it is preferable that the first medium and the second medium have a larger refractive index than the air layer.

In addition, the light emitted from the light source is incident to the first medium and exits through the second medium, the light transmitting body may include an optical sheet, a lens.

The present invention also includes a light emitting chip, a light transmitting body encapsulating the light emitting chip, and an external power input member for applying an external power source to the light emitting chip, wherein the light transmitting body includes a medium having different refractive indices. The interface between the media having different refractive indices may have a predetermined slope with respect to light emitted from the light emitting chip.

In this case, it is preferable that the light transmitting body includes a first medium and a second medium, and irregularities are formed on an interface between the first medium and the second medium to have a predetermined slope with respect to the light emitted from the light emitting chip.

The present invention also includes a light emitting chip, a light transmitting body encapsulating the light emitting chip, and an external power input member for applying external power to the light emitting chip, wherein the light transmitting body includes a medium having a different refractive index. The backlight unit may include a light emitting diode having a predetermined slope with respect to the emitted light.

In this case, the backlight unit according to the present invention may further include an optical sheet for refracting the light emitted from the light emitting diode.

The optical sheet may include a medium having different refractive indices, and the interface of the medium having different refractive indices may have a predetermined slope with respect to light emitted from the light emitting diode.

In addition, the optical sheet may include a first medium and a second medium, and irregularities may be formed at the interface between the first medium and the second medium, and thus have a predetermined slope with respect to the light emitted from the light emitting diode.

At this time, the predetermined slope is 15 to 45 degrees is the best light extraction efficiency.

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

However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like reference numerals in the drawings refer to like elements.

1 is a view for explaining the total reflection, Figure 2 is a view for explaining the path of the light according to the medium and its refractive index, Figure 3 is a graph of light extraction efficiency according to the medium and its refractive index, Figure 4 It is a graph of light extraction efficiency according to the angle of the medium interface for. In this case, the test conditions of FIGS. 3 and 4 have a distance of 5 mm between the first medium and the second medium, and the position of the detector is located at a distance of 40 mm from the first medium.

Referring to FIG. 1, the critical angle refers to the value of the incident angle θc at which total reflection occurs at a larger angle when light is incident from a material having a large refractive index to a small material. That is, for example, when a material having a large refractive index is referred to as a first medium n ₁ and a material having a small refractive index as a second medium n ₂ , a medium having different light as shown in FIG. When the refraction meets (n ₂ <n ₁ ), the incident angle at which the refraction angle is 90 degrees is referred to as a critical angle, and the incident angle refers to an angle θ c1 measured based on a normal line. If the angle of incidence is larger than the critical angle, total internal reflection occurs. In addition, when the incident angle is smaller than the critical angle, total reflection does not occur, and light is incident on a material having a large refractive index, that is, a small material, that is, a second medium n ₂ , in the first medium n ₁ . On the other hand, when light enters the first medium n ₁ having a large refractive index from the second medium n ₂ having a small refractive index, total reflection does not occur.

An optical component comprising a first medium (n ₁₎ and the second medium (n ₂₎ as described above, i.e., light transmitting body is the first medium (n ₁₎ is the second medium having a refractive index higher or more than (n ₂₎ the first medium may have a second medium (n ₂₎ than in the low index of refraction and, includes four structure in which an air layer between the first medium (n ₁₎ and the second medium (n ₂₎ is formed.

For a light transmitting member having such a structure, referring to FIG. 2, FIG. 2 (a) shows that the first medium n ₁ has a lower refractive index than the second medium n ₂ , and the first medium n ₁ and the second medium. As an air layer is formed between (n ₂ ), light is incident on the first medium n ₁ and is emitted to the outside through the air layer and the second medium n ₂ . In this case, the light incident on the first medium n ₁ is refracted or totally reflected at the interface with the air layer, and the light refracted and incident on the air layer is refracted at the interface with the second medium n ₂ and is second Incident on the medium n ₂ . In addition, the light incident on the second medium n ₂ is refracted at the interface with the outside air and exits.

Figure 2 (b) is a case of an air layer between the first medium (n ₁₎ is the second medium with high refractive index than that (n ₂₎ the first medium (n ₁₎ and the second medium (n ₂₎ is omitted, the light is incident to the first medium (n ₁₎ is emitted to the outside through the second medium (n _2). In this case, the first medium (n ₁₎ the light of the second medium is refracted or totally reflected by the interface between the (n _2), is refracted a second medium (n ₂₎ the light is again refracted incident to the outside is incident to the It is emitted or totally reflected.

Figure 2 (c) is a case of an air layer between the first medium (n ₁₎ is the second medium (n ₂₎ than the low refractive index the first medium (n ₁₎ and the second medium (n ₂₎ is omitted, the light is incident to the first medium (n ₁₎ and exits to the outside through the second medium (n _2). In this case, the light incident to the first medium (n ₁₎ is refracted at the interface of the second medium (n ₂₎ is incident on the second medium (n _2), the incident on the second medium (n ₂₎ The light is refracted again and exited or totally reflected outside.

In the case of FIG. 2 (c), total internal reflection does not occur at the interface between the first medium n ₁ and the second medium n ₂ , and thus it may be efficient for light extraction, but as shown in FIG. ₂ ) In the case of total internal reflection at the interface between the outside air and the outside air, the light extraction efficiency is inevitably inferior to the total internal reflection.

Looking at the light extraction efficiency for the light transmitting body having the combination as described above, as shown in Figure 3 (a), an air layer is formed between the first medium (n ₁ ) and the second medium (n ₂ ) and the first medium (n ₁₎ is the second medium (n ₂₎ the amount than the smaller the refractive index over the first medium (n ₁₎ the light is air and the second medium enters the (n ₂₎ emitted to the outside of about 36.14% It can be seen that. In addition, in FIG. 3B, an air layer is formed between the first medium n ₁ and the second medium n ₂ , similarly to FIG. 3A, but the first medium n ₁ is the second medium. The test was performed for the case where the refractive index was larger than (n ₂ ). In this case, only the refractive index of the first medium (n ₁ ) and the second medium (n ₂ ) was changed, but the light extraction efficiency is about 25.57%, it can be seen that about 10.57% lower than in the case of Figure 3 (a). In addition, Figure 3 (c) is the index of refraction than the first medium (n ₁₎ and the second medium (n ₂₎ in a case of an air layer is omitted between the first medium (n ₁₎ is the second medium (n ₂₎ High case was tested. In this case, the light extraction efficiency is about 29.23%, which is about 3.66% higher than when the air layer is formed between the first medium (n ₁ ) and the second medium (n ₂ ). In addition, FIG. 3 (d) also shows a case where the air layer is omitted between the first medium n ₁ and the second medium n ₂ , but unlike FIG. 3 (c), the first medium n ₁ is the second medium. The case of the refractive index lower than (n ₂ ) was tested. In this case, the light extraction efficiency is about 41.14%, and the light extraction efficiency is about 5% higher than when the air layer is formed between the first medium n ₁ and the second medium. Looking at the test results as described above, when the air layer is omitted between the first medium (n ₁ ) and the second medium (n ₂ ) and the first medium (n ₁ ) has a lower refractive index than the second medium (n ₂ ) It can be seen that the light extraction efficiency is the highest.

In this case, in the two media having different refractive indices as described above, if the interface between the first medium n ₁ and the second medium n ₂ has a predetermined slope with respect to the light source, the slope as shown in FIG. As a result, light extraction efficiency and light distribution can be seen to change.

The graph shown in FIG. 4 (a) is a light transmitting body in which the first medium n ₁ and the second medium n ₂ have an inclination of 30 degrees with respect to the light source. It is about 32.81% and the total area is about 66.41%. In addition, referring to FIG. 4B, when the first medium n ₁ and the second medium n ₂ have an inclination of 45 degrees with respect to the light source, the light extraction efficiency is about 22.42%. The total area is about 66.41%. In addition, referring to FIG. 4C, when the first medium n ₁ and the second medium n ₂ have an inclination of 60 degrees with respect to the light source, the effective light extraction efficiency area (dashed line area) is about 12.35%. The total area is about 85.50%. In this case, the effective area is a right 90 degree region with respect to the light source, and only the right 90 degree region is valid with respect to the light source and the left 90 degree region is excluded when designing the optical component. That is, only the light emitted from the effective region, not the entire region of the light transmitting member, should be regarded as the light extraction efficiency value. Therefore, the total light extraction efficiency is highest when the first medium n ₁ and the second medium n ₂ have a 60 degree inclination with respect to the light source, but the light extraction efficiency with respect to the effective area (dotted line area) is 30 degrees. since the highest when it has, the most excellent light extraction efficiency, the slope of the first medium (n ₁₎ and the second medium (n ₂₎ is to 30 degrees are preferred.

Next, a light emitting diode using a lens using the aforementioned optical properties will be described with reference to the accompanying drawings.

FIG. 5 is a schematic cross-sectional view of a light emitting diode having a lens as a light transmitting body according to a first embodiment of the present invention, and FIG. 6 is a view for explaining a light movement path of the light emitting diode according to the present invention.

The light emitting diode 240 according to the present invention includes a light emitting chip 140 as a light source and a light transmitting body 180 encapsulating the light emitting chip 140. In this case, the light emitting chip 140 may further include an external power connection member for applying external power, and a base member on which the light emitting chip 140 is mounted.

The light transmitting member 180 encapsulates and protects the light emitting chip 140, which is a light source, and emits light emitted from the light emitting chip 140 to the outside, and includes a lens in this embodiment.

The light transmitting body 180 according to the present exemplary embodiment may include a first medium n ₁ and a second medium n ₂ , and the first medium n ₁ is the light emitting chip 140. ) And the second medium (n ₂ ) preferably encapsulates the first medium (n ₁ ). In addition, in the light transmitting body 180 according to the present embodiment using the above-described optical properties, an interface between the first medium n ₁ and the second medium n ₂ has a light source, that is, the light emitting chip 140. It is preferable to have a predetermined angle. That is, the first interface between the first medium n ₁ and the second medium n ₂ has a predetermined angle with the light emitted from the light emitting chip 140 in order to transmit the light emitted from the light emitting chip 140 as much as possible. That is, it is preferable to achieve the first angle θ ₁ . In addition, the second interface between the second medium (n ₂ ) and the outside air is preferably formed with irregularities on the surface for light scattering.

In this case, the first angle θ ₁ draws a tangent to the circle formed when the light emitted from the active layer (not shown) of the light emitting chip 140 travels the same distance, and the angle between the tangent and the medium. Can be defined

In addition, as described above, the lens according to the present embodiment, in which the first interface of the first medium n ₁ and the second medium n ₂ has the first angle θ ₁ with respect to the light emitted from the light source, It is preferable that the shape is hemispherical and the longitudinal cross section is triangular saw-shaped so that the first interface plane of the first medium n ₁ and the second medium n ₂ has the first angle θ ₁ .

In addition, as described above, the first angle θ ₁ preferably forms 15 to 45 degrees with the center of the light emitting chip 140, that is, the light emitted from the active layer 140, and the first angle θ _1. ) Is 30 degrees, the highest light extraction efficiency.

Lens of this embodiment having the structure as described above is the first medium (n ₁₎ of the second all-sheet quality (n ₂₎ than the refractive index is low, because the first medium (n ₁₎ the transmitted light without reflecting the Incident on two media (n ₂ ). In this case, since the second medium n ₂ has a lower refractive index than the first medium n ₁ , the light is refracted to the right and is incident on the second medium n ₂ . In addition, the light incident to the second medium is again reached the second interface of the second medium (n ₂₎ and the outside air, to the second interface of the second medium (n ₂₎ and the outside air as described above, Reached light is refracted by the second boundary surface and emitted (1, 2, 3) to the outside or total reflection 4). In this case, is totally reflected at the second interface between the re-incident on the second medium (n ₂₎ light (④) is not due to a difference in refractive index is incident again to the first medium (n _1), the second medium (n ₂₎ in the Total internal reflection. Therefore, red (R), green (G), and blue (B) light emitted from the light emitting chip 140 is reflected and mixed in the second medium n ₂ . In addition, the red (R), green (G), and blue (B) light emitted from the light emitting chip 140 as described above may undergo total internal reflection several times in the second medium (n ₂ ), thereby moving the light like a light guide plate. White Mixing becomes even better. Therefore, the color distribution has a uniform white (W), and this light is mixed in the second medium (n ₂ ) and then emitted to air, that is, outside.

As described above, the present invention can maximize the diffusion distance and light extraction efficiency of light by attaching two different refractive index materials to each other but giving a predetermined angle.

On the other hand, the light emitting chip 140 is a light source of the light emitting diode 240 according to the present embodiment, as a compound semiconductor stacked structure having a pn junction structure uses a phenomenon that light is emitted by the recombination of minority carriers (electrons or holes). . The light emitting chip 140 may include an active layer formed between the first and second semiconductor layers and the first and second semiconductor layers. In this embodiment, the first semiconductor layer is a P-type semiconductor layer, and the second semiconductor layer is an N-type semiconductor layer. In addition, a P-type electrode is formed on the upper surface of the light emitting chip 140, that is, one surface of the P-type semiconductor layer, and an N-type electrode is formed on the lower surface of the light emitting chip 140, that is, one surface of the N-type semiconductor layer. However, the present invention is not limited thereto, and the light emitting chip 140 according to the present invention may use a horizontal light emitting chip in addition to the vertical light emitting chip as described above, and may use various types of light emitting chips emitting visible light or ultraviolet light. . In the present embodiment, three light emitting chips emitting red (R), green (G), and blue (B) may be used as the light emitting chip 140 as described above. In addition, in order for the light emitting chip 140 to emit red (R), green (G), and blue (B), the light emitting chip 140 itself is red (R), green (G), and blue (B). The light emitting chip which emits light or emits ultraviolet rays, and a phosphor for exciting the ultraviolet rays with red (R), green (G) and blue (B) light, using red (R), green (G) and blue (B). Can be implemented.

On the other hand, the above-described optical properties may be applied to the light emitting chip 140. For example, GaN having a refractive index of 2.5 is used as a semiconductor layer of the light emitting chip 140, and a ZnO ₂ layer having a refractive index of 2 or a TiO ₂ layer having a refractive index of 2.7 is formed on the semiconductor layer, and then ZnO is formed. It can be applied by forming a transparent conductive thin film (Indium Tin Oxide (ITO)) layer having a refractive index of 1.7 on the _two layers. In this case, it is preferable to form irregularities on the interface between the semiconductor layer and the ZnO ₂ layer or the TiO ₂ layer of 2.7 and the surface of the transparent conductive thin film so as to have a predetermined slope with respect to the light emitted from the active layer.

The external power connection member is for connecting the light emitting chip 140 and an external power source, and may include a lead 120 and a wire 160 in the present embodiment.

The lead 120 is for applying an external power source to the light emitting chip 140 and includes first and second leads 120a and 120b formed at one side and the other side of the housing 100, respectively. In this case, portions of the first and second leads 120a and 120b may be inserted into the housing 100, and the remaining portions may protrude outside the housing 100 to receive external power.

The wiring 160 is for electrically connecting the light emitting chip 140 and the second lead 120b and may be formed of gold (Au) or aluminum (Al) through a process such as a wire bonding process. Meanwhile, when the light emitting chip 140 is horizontal, two wires may be used to electrically connect the first and second leads 120a and 120b and the horizontal light emitting chip.

In this case, the lead 120 is a member directly connected to an external power source, and the wiring connects the lead 120 and the light emitting chip 140 to the external power applied to the lead 120 to the light emitting chip 140. To communicate with In addition, for this purpose, the N-type electrode of the light emitting chip 140 may be in contact with the first lead 120a, and the P-type electrode may be electrically connected to the second lead 120b by the wiring 160.

The base member is for mounting the light emitting chip 140 and installing an external power input member, and may include a housing 100 in the present embodiment.

The housing 100 is to support and protect the entire structure of the light emitting device. The housing 100 may be made of an insulating material such as poly phthalamide (PPA) or liquid crystal polymer (LCP). The housing 100 made of the insulating material as described above is electrically shorted while supporting the first lead 120a and the second lead 120b formed on the housing 100.

However, the present invention is not limited thereto, and the base member may be a substrate. In other words, any structure that can support the light emitting chip 140 and install an external power supply member can be used as a base member.

Next, an optical sheet that is a light transmitting body according to a second exemplary embodiment of the present invention will be described with reference to the drawings. In this embodiment, a prism sheet among optical sheets such as a diffusion sheet and a prism sheet will be described as an example.

7 is a schematic cross-sectional view of a prism sheet that is a light transmitting body according to a second embodiment of the present invention.

As shown in FIG. 7, the prism sheet according to the present exemplary embodiment includes a third medium n ₃ and a fourth medium n ₄ formed on the third medium n ₃ .

At this time, as for turning on the light transmission chain prism sheet according to the present embodiment is rising the brightness by refracting, condensing the light emitted from the light source, the first formed on a third medium (n ₃₎ and the third medium (n ₃₎ 4 medium (n ₄ ). In this case, the prism sheet in order to take advantage of the aforementioned optical properties of the third medium (n ₃₎ of the present embodiment is preferably a high index of refraction than the fourth medium (n _4), the third medium (n ₃₎ and It is preferable that the fourth medium n ₄ has a predetermined slope with respect to the light source.

That is, the first interface between the third medium (n ₃ ) and the fourth medium (n ₄ ) should have a predetermined slope, and the third medium (n ₄ ) in contact with the fourth medium (n ₄ ) to have such a slope. It is preferable to form the uneven | corrugated shape which protruded on the surface of ₃ ). That is, it is preferable that a plurality of spherical protrusions are formed on the surface of the third medium n ₃ , and irregularities are formed on the surfaces of the plurality of protrusions so as to have a light source and a predetermined slope. However, the present invention is not limited thereto, and a protrusion and protrusion may be formed on the surface of the fourth medium n _{4 in} contact with the third medium n ₃ .

In the prism sheet according to the present embodiment having such a structure, part of the light incident on the fourth medium n ₄ through the third medium n ₃ is totally reflected at the second interface with the outside air, and the light is as described above. The total reflection of red (R), green (G), and red (R) light emitted from the light emitting diode may be mixed in the fourth medium (n ₄ ) to implement white (W) having a uniform color distribution. Further, the light is totally reflected in the fourth medium (n ₄₎ as described above, the light can be uniformly emitted to the outside from the entire region of the fourth medium (n _4).

Meanwhile, in the prism sheet according to the present embodiment, when the light emitted from the light source is incident and exited out through the prism sheet, irregularities (dotted regions) are formed on one surface to make the traveling direction perpendicular to the prism sheet. desirable.

Next, a backlight unit provided with a light transmitting body according to the present invention will be described with reference to the accompanying drawings.

8 is a schematic exploded perspective view of a backlight unit provided with a light transmitting body according to the present invention.

The backlight unit with the light transmitting body according to the present invention includes a light emitting diode 240 and an optical sheet 300 provided on the light emitting diode 240 as shown in FIG. 8. In this case, the light emitting diode 240 may further include an accommodating member 200 for accommodating and protecting the optical sheet 300. In addition, the light emitting diode 240 may further include a reflecting sheet 220 for reflecting light traveling in the direction of the accommodating member 200 from the light emitting diode 240.

The light emitting diode 240 is a light emitting diode according to the first embodiment, and includes a light emitting chip as a light source and a light transmitting body encapsulating the light emitting chip. At this time, an external power connection member for applying external power to the light emitting chip, and a base member for mounting the light emitting chip may be further included.

The light transmitting body is to encapsulate and protect the light emitting chip as a light source and to emit light emitted from the light emitting chip to the outside, and includes a lens in this embodiment.

The light transmitting body according to the present embodiment as described above may include a first medium (n ₁ ) and a second medium (n ₂ ), as shown in FIG. 5, wherein the first medium (n ₁ ) is the It is preferable that the light emitting chip is encapsulated and the second medium n ₂ encapsulates the first medium n ₁ . In addition, in the light transmitting body according to the present embodiment using the above-described optical properties, it is preferable that the first medium n ₁ and the second medium n ₂ have a predetermined angle with respect to the light source. That is, the first interface between the first medium n ₁ and the second medium n ₂ is a predetermined angle, ie, a first angle, with the light emitted from the light emitting chip in order to transmit the light emitted from the light emitting chip as much as possible. θ ₁ ) is preferable. In addition, the second interface between the second medium (n ₂ ) and the outside air is preferably formed with irregularities for scattering light emitted from the light emitting chip. In this case, as described above, the first angle θ ₁ preferably forms 15 to 45 degrees with the center of the light emitting chip, that is, the light emitted from the active layer, and the first angle θ ₁ is 30 degrees. The light extraction efficiency is high.

In addition, as described above, the lens according to the present embodiment, in which the first interface of the first medium n ₁ and the second medium n ₂ has the first angle θ ₁ with respect to the light emitted from the light source, It is preferable that the shape is hemispherical and the longitudinal cross section is triangular saw-shaped so that the first interface plane of the first medium n ₁ and the second medium n ₂ has the first angle θ ₁ .

In the lens according to the present exemplary embodiment having the above structure, a part of the light incident on the second medium n ₂ through the first medium n ₁ is totally reflected at the interface with the outside air, and the light is totally reflected as described above. Red (R), green (G), and red (R) light emitted from the light emitting chip may be mixed in the second medium (n ₂ ) to implement white (W) having a uniform color distribution. Further, the light is totally reflected in the second medium (n ₂₎ as described above, the light can be uniformly emitted to the outside from the entire area of the second medium (n _2).

The optical sheet 300 is to increase the output of the light emitted from the light emitting diode 240 in the direction perpendicular to the optical sheet 300, and to improve the light quality, in this embodiment the diffusion sheet 280 ), And may include a prism sheet 181.

The diffusion sheet 280 is disposed on the upper surface of the light emitting diode 240 to uniformly diffuse the light emitted from the light emitting diode 240 and transmit the light toward the front direction of the prism sheet 181 to widen the viewing angle and bright spots, bright lines, spots, etc. In order to reduce diffusion of light, the light emitting diode 240 is preferably located between the light emitting diode 240 and the prism sheet 181. The diffusion sheet 280 may be manufactured using polycarbonate (PC) resin or polyester (PET) resin. In addition, the diffusion sheet 280 according to the present embodiment may also stack the media to each other in the same manner as the above-described prism sheet and give an inclination with respect to the light source.

The prism sheet 181 is used to increase luminance by refracting and condensing the light emitted from the diffusion sheet 280. As illustrated in FIG. 7, the third medium n ₃ and the third medium n ₃ ) a fourth medium n ₄ formed on the layer. In this case, the prism sheet 181 according to this embodiment has the third medium in order to take advantage of the aforementioned optical properties (n ₃₎ is preferably higher refractive index than the fourth medium (n _4), the third medium (n ₃ ) and the fourth medium n ₄ preferably have a predetermined slope with respect to the light source.

In addition, the prism sheet 181 has irregularities formed on one surface of the prism sheet 181 so that the traveling direction of the light is perpendicular to the prism sheet 181 when the light emitted from the light source is incident and exited through the prism sheet 181. It is preferable. In the present embodiment, two horizontal and vertical sheets may be used as one set according to the unevenness forming direction of the prism sheet 181.

In the prism sheet 181 according to the present exemplary embodiment having the above structure, part of the light incident on the fourth medium n ₄ through the third medium n ₃ is totally reflected at the interface with the outside air. The light is totally reflected and the red (R), green (G), and red (R) light emitted from the light emitting diode 240 are mixed in the fourth medium (n ₄ ) to produce white (W) having a uniform color distribution. Can be implemented. Further, the light is totally reflected in the fourth medium (n ₄₎ as described above can be uniformly emitted to the outside from the entire region of the four-sheet quality (n _4). Therefore, when the prism sheet 181 according to the present embodiment is used, the diffusion sheet 220 may be omitted.

Although described above with reference to the drawings and embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit of the invention described in the claims below. I can understand.

For example, in the illustrated embodiment, only the lens and the prism sheet of the light emitting diode have been described as an example.

As described above, the present invention attaches two media having different refractive indices to each other and has a predetermined inclination with respect to the light source, thereby having a uniform light distribution, minimizing the loss of light, and maximizing the light diffusion distance and light extraction efficiency. An optical component can be provided.

Claims (14)

Includes a plurality of media through which light is transmitted and having different refractive indices, And the interface of the medium having different refractive indices has a predetermined slope with respect to the light source. The method according to claim 1, The different media comprises a first medium and a second medium, And wherein the first medium has a lower refractive index than the second medium. The method according to claim 1 or 2, The predetermined inclination is an optical component, characterized in that 15 to 45 degrees. The method according to claim 1 or 2, And an air layer between the first medium and the second medium. The method according to claim 4, And wherein the first medium and the second medium have a higher refractive index than the air layer. The method according to claim 4, Light emitted from the light source is incident to the first medium and is emitted to the outside through the second medium. The method according to claim 1, The optical transmission member comprises an optical sheet and a lens. Light emitting chip, A light transmitting body encapsulating the light emitting chip; An external power input member for applying external power to the light emitting chip; The light transmitting member includes a medium having different refractive indices, The interface of the medium having different refractive indices has a predetermined slope with respect to the light emitted from the light emitting chip. The method according to claim 8, The light transmitting body comprises a first medium and a second medium, The light emitting diode, characterized in that the irregularities are formed on the interface between the first medium and the second medium has a predetermined slope with respect to the light emitted from the light emitting chip. With light emitting chip A light transmitting body encapsulating a light emitting chip And an external power input member for applying external power to the light emitting chip, wherein the light transmitting member includes a medium having a different refractive index, and includes a light emitting diode having a predetermined slope with respect to light emitted from the light emitting chip. Backlight unit. The method according to claim 10, And a optical sheet for refracting light emitted from the light emitting diode. The method according to claim 11, The optical sheet includes a medium having different refractive indices, The interface unit of the medium having different refractive indices has a predetermined slope with respect to the light emitted from the light emitting diode. The method according to claim 12, The optical sheet comprises a first medium and a second medium, Concave-convex is formed in the interface between the first medium and the second medium has a predetermined slope with respect to the light emitted from the light emitting diode. The method according to claim 10 or 13, The predetermined inclination is a backlight unit, characterized in that 15 to 45 degrees.

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