KR20170083354A - Light emitting device package and display device using the same as a light source - Google Patents

Abstract

Embodiments relate to a light emitting device package having improved color reproduction range and a display device using the same, wherein the light emitting device package of the present invention includes a body including a cavity; A light emitting element disposed in the body and emitting blue light; And a wavelength conversion layer covering the light emitting device and including wavelength conversion particles of red, green and cyan to realize white light.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a light emitting device package and a display device using the light emitting device package as a light source.

Embodiments of the present invention relate to a light emitting device package having improved color reproduction range and a display device using the same.

A light emitting diode (LED) is one of light emitting devices that emits light when current is applied. Light emitting diodes are capable of emitting light with high efficiency at low voltage, thus saving energy. In recent years, the problem of luminance of a light emitting diode has been greatly improved, and it has been applied to various devices such as a backlight unit of a liquid crystal display device, a display board, a display device, and a home appliance.

The light emitting diode can be implemented in various colors by controlling the composition ratio of the compound semiconductor. For example, nitride semiconductors have received great interest in the development of optical devices and high power electronic devices due to their high thermal stability and wide bandgap energy. A blue light emitting element, a green light emitting element, and an ultraviolet (UV) light emitting element using a nitride semiconductor are commercially available and widely used.

Particularly, a light emitting element that emits blue light and wavelength conversion particles can be used to realize white light. A light emitting diode package that implements white light can be used as a light source of a display device. The display device can generally constitute one unit pixel of blue, red and green subpixels in which blue, red and green color filters are respectively disposed and emit light from a light emitting diode package The light of the color corresponding to each color filter can be realized while the white light passes through the color filter.

SUMMARY OF THE INVENTION The present invention provides a light emitting device package having improved color reproduction range and a display device using the same.

The light emitting device package of the present invention includes a body including a cavity; A light emitting element disposed in the body and emitting blue light; And a wavelength conversion layer covering the light emitting device and including wavelength conversion particles of red, green and cyan to realize white light.

The display device of the embodiment of the present invention includes a light source package including a light emitting device package that emits blue light of a light emitting element as white light using wavelength conversion particles of red, green, and cyan; And a panel for implementing white light incident from the light source as light of a color corresponding to each of the color filters through a color filter, wherein the panel is formed of at least one of blue, cyan, and a plurality of unit pixels each including four subpixels in which red color filters are disposed.

The light emitting device package of the present invention and the display device using the same as the light source have the following effects.

First, white light can be realized by using blue, green, red, and cyan wavelength conversion particles emitted from the light emitting device, and the color reproduction range of white light can be improved.

Secondly, when the light emitting device package is used as a light source of a display device, four subpixels, each of which includes blue, cyan, green and red color filters, Pixels are formed so that the color reproduction rate and color purity of the display device can be improved.

1 is a cross-sectional view of a light emitting device package of an embodiment of the present invention.
2A and 2B are plan views of unit pixels of a display device using the light emitting device package of the embodiment of the present invention as a light source.
3A is a spectrum of white light emitted from a general light emitting device package.
FIG. 3B is the color coordinates of white light in FIG. 3A.
4A is a spectrum of white light emitted from the light emitting device package of the embodiment of the present invention.
4B is the color coordinates of the white light of FIG. 4A.
5A to 5C are sectional views of a light emitting device package according to another embodiment of the present invention.

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

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

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

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

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

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

Hereinafter, the light emitting device package of the embodiment will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a light emitting device package of an embodiment of the present invention.

1, a light emitting device package according to an embodiment of the present invention includes a body 100, a cavity 100a formed by opening the upper portion of the body 100, a cavity 100a mounted in the cavity 100a, electrically connected to the lead electrodes 130a and 130b, And a wavelength conversion layer 150 filled in the cavity 100a to cover the light emitting device 10 and the light emitting device 10 connected thereto. In this case, the light emitting element 10 may be a chip scale package (CSP) structure. In this case, the first and second electrodes (not shown) of the light emitting element 10 are connected to the first and second leads Electrodes 130a and 130b, respectively.

Body 100 includes a polyphthalamide (Polyphthalamide; PPA), at least one of a resin material, a silicon (Si), a metal material such as, PSG (photo sensitive glass), sapphire (Al ₂ O _3), a printed circuit board (PCB) . The first and second lead electrodes 130a and 130b may be selected from PCB type, ceramic type, frame type, and plating type electrodes.

The light emitting device 10 may be an LED emitting a predetermined color such as a blue LED, a red LED, and a green LED, but is not limited thereto. In the present invention, the case where the light emitting element 10 emits blue light will be described. The light emitting device 10 may be electrically connected to the first and second lead electrodes 130a and 130b mounted on the body 100 in the cavity 100a.

Since the light emitting device 10 of the embodiment of the present invention emits blue light as described above, the wavelength conversion layer 150 may be disposed to cover the light emitting device 10 to realize white light. The wavelength conversion layer 150 may be filled in the cavity 100a.

However, the white light emitted from the light emitting diode package passes through the color filter, and a part of the white light is absorbed by the color filter, and the light flux can be remarkably reduced after passing through the color filter. Furthermore, in a general light emitting device package, when a light emitting device emits blue light, it includes yellow and red wavelength conversion particles to realize white light, which limits the implementation of white light.

Therefore, in the light emitting device package of the embodiment of the present invention, the wavelength conversion layer 150 includes the green wavelength conversion particles 150a, the red wavelength conversion particles 150b, and the cyan wavelength conversion particles 150c .

The wavelength conversion layer 150 of the present invention is formed of a polymer resin in which green wavelength conversion particles 150a, red wavelength conversion particles 150b and cyan wavelength conversion particles 150c are uniformly dispersed . At this time, the polymer resin may be at least one selected from a light-transmitting epoxy resin, a silicone resin, a polyimide resin, a urea resin, and an acrylic resin. As an example, the polymer resin may be a silicone resin.

The green wavelength conversion particles 150a, the red wavelength conversion particles 150b and the cyan wavelength conversion particles 150c of the wavelength conversion layer 150 emit blue light emitted from the light emitting element 10, Can be absorbed and converted into white light. The green wavelength conversion particles 150a, the red wavelength conversion particles 150b and the cyan wavelength conversion particles 150c may include at least one of a phosphor and a quantum dot (QD). Hereinafter, the wavelength converting particle is described as a phosphor.

The phosphor may include any one of a YAG-based, TAG-based, silicate-based, sulfide-based or nitride-based fluorescent material, but the embodiment is not limited to the type of the fluorescent material. YAG and TAG-based fluorescent material (Y, Tb, Lu, Sc , La, Gd, Sm) 3 (Al, Ga, In, Si, Fe) 5 (O, S) 12: Ce may be selected from, Silicate The phosphor can be selected from (Sr, Ba, Ca, Mg) ₂ SiO ₄ : (Eu, F, Cl)

Sulfide-based fluorescent materials can be selected from (Ca, Sr) S: Eu, (Sr, Ca, Ba) (Al, Ga) ₂ S ₄ : Eu, (O, N) ₁₆ (Ca _x , M _y ) (Si, Al) ₁₂ (O, N): Eu (e.g., CaAlSiN ₄ : Eu? -SiAlON: Eu) or Ca-? SiAlON: Eu. Here, M is at least one material selected from among Eu, Tb, Yb, and Er and can be selected from wavelength conversion particle components satisfying 0.05 <(x + y) <0.3, 0.02 <x <0.27 and 0.03 < have. The red wavelength conversion particle may be a nitride-based wavelength conversion particle including N (for example, CaAlSiN ₃ : Eu) or a KSF (K ₂ SiF ₆ ) wavelength conversion particle.

At this time, the red wavelength conversion particle (150a), the red (red) wavelength conversion particle 150b and the orange (cyan) wavelength conversion particle 150c included in the wavelength conversion layer 150 150b) may be the lowest. This is because the conversion efficiency of the red wavelength conversion particles 150b is much higher than that of the green wavelength conversion particles 150a and the cyan wavelength conversion particles 150c.

For example, the content of the cyan wavelength conversion particle 150c of the green wavelength conversion particle 150a exceeds 50% of the total of the wavelength conversion layer 150 including the resin, ) Content of the wavelength converting particles 150b may be less than 30%, but is not limited thereto.

2A and 2B are plan views of unit pixels of a display device using the light emitting device package of the embodiment of the present invention as a light source.

2A and 2B, when the light emitting device package of the embodiment of the present invention is used as a light source of a backlight unit of a display device such as a TV, the display device includes four sub pixels 200a, 200b, 200c, Pixel 200. &lt; / RTI &gt;

In general, a display device such as a liquid crystal display device includes a first substrate on which a driving element such as a thin film transistor is disposed, a second substrate on which a color filter is disposed, and a panel including a liquid crystal layer between the first and second substrates. And a backlight unit disposed on a back surface of the first substrate and including a light source.

Such a display device controls the passage of white light emitted from the light source of the backlight unit through the liquid crystal layer by rotating the liquid crystal molecules of the liquid crystal layer, and the light passing through the liquid crystal layer passes through the color corresponding to the color filter of each sub pixel Light can be realized.

A typical display device comprises a unit pixel consisting of three subpixels, each of which may comprise red, green and blue color filters. However, the display device of the present invention may include a plurality of unit pixels including four sub-pixels 200a, 200b, 200c, and 200d. At this time, the subpixels 200a, 200b, 200c, and 200d may include blue, cyan, green, and red color filters, respectively.

The four subpixels 200a, 200b, 200c, and 200d may be arranged in a matrix of 1x4 or arranged in a matrix of 2x2, as shown in Fig. The arrangement of the four sub-pixels 200a, 200b, 200c, and 200d is not limited thereto.

Specifically, the display device of the embodiment of the present invention can realize blue light emitted from the light emitting element 10 as white light through the green, red, and blue wavelength conversion particles 150a, 150b, and 150c. The white light emitted from the light emitting device package as the light source passes through the blue, orange, green, and red color filters of the subpixels 200a, 200b, 200c, and 200d, have.

3A is a spectrum of white light emitted from a general light emitting device package, and shows a relative output. FIG. 3B is the color coordinates of white light in FIG. 3A.

As shown in FIG. 3A, the white light emitted from a general light emitting device package has different light outputs for respective wavelengths. Also, as shown in FIG. 3B, a general light emitting device package can only achieve 80.1% of color compared to DCI. When white light emitted from the light emitting device package passes through the color filter as shown in the following Table 1, when the color corresponding to the color filter is realized by using the general light emitting device package as the light source of the display device, The rate is reduced to almost 1/4.

Particularly, the white light emitted from the light emitting device package has the highest blue light output (see FIG. 3A), but when passing through the color filter, the blue light flux is remarkably lowered to 6%. In addition, since the deviation of the light fluxes of green light and blue light is very large, a general display device not only has a lowered luminous flux but also does not have uniform color characteristics, and the uniformity of color implementation is lowered.

Subpixel Before passing through color filter After passing color filter Luminous flux (%) Red 100 2.2 green 19.7 blue 6.0 TOTAL 100 27.8

On the other hand, in the light emitting device package of the embodiment of the present invention, the blue light emitted from the light emitting device can be realized as white light through the green, red and blue wavelength conversion particles 150a, 150b and 150c

FIG. 4A is a spectrum of white light emitted from the light emitting device package of the embodiment of the present invention, and FIG. 4B is a color coordinate of white light of FIG. 4A.

As shown in FIG. 4A, the white light emitted from the light emitting device package of the embodiment of the present invention has peak (wavelength) between the blue wavelength band (400 nm to 500 nm) and the green wavelength band (520 nm to 570 nm) peak can be formed.

Accordingly, as shown in FIG. 4B, the color coordinates of the white light emitted from the light emitting device package of the embodiment of the present invention may have four poles. In the light emitting device package of the embodiment of the present invention, 114.9% The color reproduction rate and the color purity of the image can be improved. In particular, as the content of the quartz-wavelength converting particles 150c increases, the color coordinates of the white light can move in the A direction (left downward).

However, when the light emitting device package of the embodiment of the present invention is used as a light source of a display unit constituting one unit pixel, three subpixels including blue, green, and red color filters, The light that has been converted by the color filter does not pass through the color filter at all. Therefore, the color rendering ratio and color purity can be reduced.

Therefore, in the display device using the light emitting device package of the embodiment of the present invention as described above, one unit pixel includes four sub-pixels 200a, 200b, 200c, and 200d including red, green, &Lt; / RTI &gt; This is to optimize the spectrum of the light emitted from the light emitting device package.

That is, as shown in Table 2 below, even if the white light emitted from the light emitting device package passes through the color filter, the total light flux may increase by 10% as compared with the conventional one. In particular, although the deviation between green light and blue light is very large in the related art, the present invention can compensate for this. Therefore, the display device using the light emitting device package of the embodiment of the present invention as a light source may have uniform color characteristics, and all colors within the four poles can be realized by four color filters.

Subpixel Before passing through color filter After passing color filter Luminous flux (%) Red 100 4.5 green 15.4 Turquoise 13.8 blue 4.2 TOTAL 100 38

Hereinafter, a light emitting device package according to another embodiment of the present invention will be described.

5A to 5C are sectional views of a light emitting device package according to another embodiment of the present invention.

As shown in Figs. 5A to 5C, the wavelength conversion particles may be separated from each other.

As shown in FIG. 5A, the green, red, and blue wavelength converting particles 150a, 150b, and 150c may be separated from each other and stacked. In this case, the red, green, and blue wavelength converting particles 150b, 150a, and 150c may be sequentially disposed on the upper surface of the cavity 100a in the adjacent region in the light emitting device 10 in consideration of the excitation efficiency. This is because the wavelength of the red wavelength conversion particle 150b is the shortest and the wavelength of the joule wavelength conversion particle 150c is the longest. In this case, the color conversion particles 150c, 150b and 150a may be arranged as shown in the figure when they are dispersed in different polymer resins and completely separated or dispersed in the same polymer resin.

In addition, as shown in FIG. 5B, only two wavelength converting particles may be mixed. In the drawing, the blue wavelength converting particles 150c and the green wavelength converting particles 150a are mixed with each other. At this time, the red wavelength conversion particles 150b have a longer wavelength than the green wavelength conversion particles 150a and the red wavelength conversion particles 150b, The green wavelength conversion particles 150a can be arranged closer to the light emitting element 10 than the green wavelength conversion particles 150a.

5C, when the sedimentation method in which the wavelength conversion particles are settled by gravity is used, the yaw wavelength conversion particles 150c and the green wavelength conversion particles 150a, which are relatively large in particle size, And the red wavelength conversion particles 150b may be disposed on the upper surface.

On the other hand, the order and mixing of the wavelength converting particles can be easily changed in consideration of the light emitting efficiency and the extraction efficiency.

As described above, the light emitting device package of the embodiment of the present invention can convert the blue light emitted from the light emitting element 10 into white light using the green, red and blue wavelength conversion particles 150a, 150b and 150c, The color reproduction range of white light can be improved. In addition, the display device using the light emitting device package of the embodiment of the present invention as a light source may further include a sub-pixel including a color filter of a unit color pixel, thereby improving the display ratio and color purity of white light emitted from the light emitting device package .

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge.

10: Light emitting device 100: Body
100a: cavity 130a: first lead electrode
130b: first and second lead electrodes 150: wavelength conversion layer
150a: green wavelength conversion particle 150b: red wavelength conversion particle
150c: Cyan wavelength conversion particle 200: unit pixel
200a: first sub-pixel 200b: second sub-pixel
200c: third sub-pixel 200d: fourth sub-pixel

Claims (12)

A body including a cavity;
A light emitting element disposed in the body and emitting blue light;
And a wavelength conversion layer covering the light emitting device and including wavelength conversion particles of red, green, and cyan to realize white light. The method according to claim 1,
Wherein the wavelength conversion layer is a structure in which the wavelength conversion particles of red, green, and cyan are uniformly dispersed. The method according to claim 1,
Wherein the content of the red wavelength conversion particles is smaller than the content of the blue and euchromatic wavelength conversion particles. The method according to claim 1,
Wherein the wavelength conversion layer is a structure in which the wavelength conversion particles of red, green, and cyan are separated from each other. The method according to claim 1,
Wherein the white light has four pole points in a color coordinate. The method according to claim 1,
Wherein the red wavelength conversion particle comprises KSF (K ₂ SiF ₆ ). A light source package including a light emitting device package that emits blue light of a light emitting device as white light using wavelength conversion particles of red, green, and cyan; And
And a panel for implementing white light incident from the light source as light of a color corresponding to each color filter through a color filter,
Wherein the panel comprises a plurality of unit pixels including four subpixels in which blue, cyan, green, and red color filters are respectively disposed. 8. The method of claim 7,
Wherein the unit pixels include the 4 subpixels arranged in a 1x4 matrix structure. 8. The method of claim 7,
Wherein the unit pixels include the 4 subpixels arranged in a 2x2 matrix structure. 8. The method of claim 7,
Wherein the content of the red wavelength conversion particles is smaller than the content of the blue and euchromatic wavelength conversion particles. 8. The method of claim 7,
Wherein the white light of the light emitting device package has four pole points in a color coordinate. 8. The method of claim 7,
Wherein the red wavelength conversion particle of the light emitting device package comprises KSF (K ₂ SiF ₆ ).

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