KR102514150B1 - Light emitting device and lighting unit having thereof - Google Patents

Abstract

The embodiment discloses a light emitting device having a phosphor. The light emitting device disclosed in the embodiment includes a light emitting chip emitting blue light; a first phosphor absorbing the light emitted from the light emitting chip at an excitation wavelength and emitting light of a first peak wavelength of green; and a second phosphor for absorbing the light emitted from the light emitting chip at an excitation wavelength and emitting a second peak wavelength of red, wherein the second peak wavelength has a long wavelength among red wavelengths, and the blue, green and In white light mixed with red, the red light has a delta saturation value of zero (0) or greater compared to a preselected color quality scale (CQS).

Description

Light emitting element and lighting device having the same {LIGHT EMITTING DEVICE AND LIGHTING UNIT HAVING THEREOF}

The embodiment relates to a light emitting device and a lighting device having the same.

A light emitting device is a device having a characteristic of converting electrical energy into light energy, and includes, for example, a light emitting diode (LED), and the LED can implement various colors by adjusting the composition ratio of compound semiconductors.

For example, nitride semiconductors are of great interest in the field of developing optical devices and high-power electronic devices due to their high thermal stability and wide bandgap energy. In particular, blue light emitting devices, green light emitting devices, ultraviolet (UV) light emitting devices, and the like using nitride semiconductors are commercialized and widely used.

An LED emitting white light is a method of using a secondary light source that emits light from a phosphor by applying a phosphor, and a method of obtaining white light by applying a YAG:Ce phosphor that emits yellow to a blue LED is common.

However, the method has disadvantages in that quantum deficits and efficiency reduction due to re-radiation efficiency occur while using secondary light, and color rendering is not easy.

Therefore, the conventional white LED backlight is a combination of a blue LED chip and a yellow phosphor, and is limited to the extent of being used for screens of mobile phones and notebook PCs because it lacks green and red components and has no choice but to express unnatural colors. Nevertheless, it is widely commercialized due to the advantages of easy operation and remarkably low price.

A particularly preferred use of a white LED element made of a blue chip and a yellow phosphor is for backlights used in mobile phones, personal digital assistants, and the like. However, due to the use of a yellow phosphor (e.g., peak emission appears between 590 nm and 610 nm), the LED's spectrum contains excessive emission in the yellow region of the spectrum, strongly reducing the color gamut of the backlight.

A color gamut is the area spanned between the color points of the red, green, and blue pixels of a display in a chromaticity diagram, eg, the CIE 1931 x,y chromaticity diagram. The historical "golden standard" of displays is the NTSC gamut defined by a set of three color point coordinates. Generally, a full range in excess of 70% of NTSC is considered acceptable for many backlighting applications, and a full range in excess of 90% of NTSC is considered acceptable for most any of these applications.

When the full range of the LED backlight is improved by using the yellow phosphor, the yellow light is removed and thus the luminous intensity of the LED backlight is reduced. Therefore, it would be advantageous to develop a white LED capable of increasing luminous intensity without using a yellow phosphor in the package.

The CRI is an eight standard commonly referred to as the General Color Rendering Index and abbreviated Ra, although 14 standard color samples are internationally specified and as an average of these a broader CRI (R1-14) can be calculated. It is generally defined as the average value of color samples (R1-8). Specifically, the R9 value, which measures color rendering for strong red, is very important for various applications, particularly lighting or medical fields requiring a high color rendering index.

The embodiment provides a light emitting device having a red phosphor and a green phosphor using blue light as an excitation wavelength.

The embodiment provides a light emitting device including a blue light emitting chip, a green phosphor and a red phosphor, and a lighting device including the same.

An embodiment is a light emitting device in which a color difference value of at least one of red, green, and blue of white light in which blue light, green light, and long-wavelength red light are mixed has a value similar to or higher than that of sunlight, and a lighting device having the same provides

Embodiments provide a light emitting device having a red delta saturation value of white light in which blue light, green light, and long-wavelength red light are mixed has a value similar to or higher than that of sunlight, and a lighting device including the same.

A light emitting device according to an embodiment includes a light emitting chip emitting blue light; a first phosphor absorbing the light emitted from the light emitting chip at an excitation wavelength and emitting light of a first peak wavelength of green; and a second phosphor for absorbing the light emitted from the light emitting chip at an excitation wavelength and emitting a second peak wavelength of red, wherein the second peak wavelength has a long wavelength among red wavelengths, and the blue, green and In white light mixed with red, the red light has a delta saturation value of zero (0) or greater compared to a preselected color quality scale (CQS).

According to the embodiment, it is possible to provide a light emitting device and a lighting device having different combinations of phosphors and light emitting chips.

According to the embodiment, red color in white light emitted from a light emitting device or lighting device can be expressed more brightly and vividly compared to sunlight.

In the embodiment, blue in white light emitted from a light emitting device or lighting device can be expressed more brightly and vividly compared to sunlight.

According to the embodiment, green color in white light emitted from a light emitting device or lighting device can be expressed more brightly and vividly compared to sunlight.

The embodiment may improve reliability of a light emitting device and a lighting device including the light emitting device.

1 is a cross-sectional view of a light emitting device including a phosphor according to an embodiment.
2 is a view showing another example of a light emitting device having a phosphor according to an embodiment.
3 is a view showing another example of a light emitting device having a phosphor according to an embodiment.
4 is a view showing a light emitting device having a film to which a phosphor is added according to an embodiment.
5 is a view showing a lighting device having a film to which a phosphor is added according to an embodiment.
6 is a diagram illustrating color samples of a reference light source and a fluorescent lamp in a CIE color space and a color difference thereof.
7 is a diagram showing a color sample and a color difference between a reference light source and a CRI 90 LED in a CIE color space.
8 is a diagram showing color samples and color differences between a reference light source and a light emitting device according to Example 1 in a CIE color space.
9 is a diagram illustrating color samples and color differences between a reference light source and a light emitting device according to Example 2 in a CIE color space.
10 is a diagram comparing wavelength spectra of a fluorescent lamp, a CRI 90 LED of a comparative example, and a light emitting device according to Examples 1 and 2.
11 is a diagram illustrating a CIE L*a*b* color space.
12 is a diagram comparing a color quality scale previously selected in the CIE color space with a color sample of a light emitting device according to an embodiment.
13 is a graph showing delta saturation between a preset color quality scale in the CIE color space and a light emitting device according to an embodiment.
14 is an exploded perspective view illustrating a lighting device having a light emitting device according to an embodiment.

In the description of the embodiment, each layer (film), region, pattern or structure is "on/over" or "under" the substrate, each layer (film), region, pad or pattern. In the case where it is described as being formed in, "on/over" and "under" include both "directly" or "indirectly" formed through another layer. do. In addition, the criteria for the top/top or bottom of each layer will be described based on the drawings.

A light emitting device having a phosphor according to an embodiment will be described. 1 is a cross-sectional view showing a light emitting device having a phosphor according to an embodiment.

Referring to FIG. 1 , a light emitting device 10 includes a body 11, a plurality of lead frames 21 and 23, a light emitting chip 25, and a molding member 41 having phosphors 31 and 33. .

The body 11 may be formed of a material having a reflectance higher than transmittance, for example, a reflectance of 70% or more with respect to a wavelength emitted by the light emitting chip 25 . When the reflectance of the body 11 is 70% or more, it may be defined as a non-transmissive material. The body 11 may be formed of a resin material such as a resin-based insulating material, for example, polyphthalamide (PPA). A metal oxide may be added to the body 11 in a resin material such as epoxy or silicon, and the metal oxide may include at least one of TiO ₂ , SiO ₂ , and Al ₂ O ₃ .

The body 11 includes a silicone-based, epoxy-based, or plastic material, and may be formed of a thermosetting resin or a material with high heat resistance and high light resistance. In addition, an acid anhydride, an antioxidant, a release agent, a light reflector, an inorganic filler, a curing catalyst, a light stabilizer, a lubricant, and titanium dioxide may be selectively added to the body 11. The body 11 may be molded by at least one selected from the group consisting of epoxy resin, modified epoxy resin, silicone resin, modified silicone resin, acrylic resin, and urethane resin. For example, an epoxy resin composed of triglycidyl isocyanurate, hydrogenated bisphenol A diglycidyl ether, etc., an acid composed of hexahydrophthalic anhydride, 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, etc. DBU (1,8-Diazabicyclo (5,4,0) undecene-7) as a curing accelerator and ethylene glycol, titanium oxide pigment, and glass fibers as cocatalysts were added to an epoxy resin, and partially cured by heating. A solid epoxy resin composition subjected to a curing reaction and converted into a B stage can be used, but is not limited thereto.

A light blocking material or a diffusion agent may be mixed in the body 11 to reduce transmitted light. In addition, in order for the body 11 to have a predetermined function, at least one selected from the group consisting of a diffusion agent, a pigment, a fluorescent material, a reflective material, a light blocking material, a light stabilizer, and a lubricant is properly mixed with a thermosetting resin. You can do it.

As another example, the body 11 may be formed of a light-transmissive resin material or a resin material having a phosphor according to an embodiment that converts the wavelength of incident light. When the body 11 is formed of a light-transmitting material, 70% or more of the light emitted from the light-emitting chip 25 may be transmitted.

The body 11 is recessed to a predetermined depth from the upper surface of the body 11 and includes a cavity 15 with an open top. The cavity 15 may be formed in a shape such as a concave cup structure, an open structure, or a recess structure, but is not limited thereto. The cavity 15 has a width that gradually widens as it goes up, so light extraction efficiency can be improved.

A plurality of lead frames, for example, first and second lead frames 21 and 23 may be coupled to the body 11 . The first and second lead frames 21 and 23 may be disposed on the bottom of the cavity 15, and outer portions of the first and second lead frames 21 and 23 pass through the body 11. It may be exposed on at least one side of the body 11. Lower portions of the first lead frame 21 and the second lead frame 23 may be exposed to the lower portion of the body 11 and may be mounted on a circuit board to receive power.

As another example of the first and second lead frames 21 and 23, at least one or both of the first and second lead frames 21 and 23 are formed in a concave cup-shaped structure or a bent structure. It may have, or may include a recessed groove or hole for coupling with the body 11, but is not limited thereto. The light emitting chip 25 may be disposed in the concave cup shape, but is not limited thereto.

The first lead frame 21 and the second lead frame 23 are made of a metal material, for example, titanium (Ti), copper (Cu), nickel (Ni), gold (Au), chromium (Cr), tantalum It may include at least one of nium (Ta), platinum (Pt), tin (Sn), silver (Ag), and phosphorus (P), and may be formed as a single layer or multiple layers.

A light emitting chip 25 is disposed on the first lead frame 21 , and the light emitting chip 25 may be adhered to the first lead frame 21 by a bonding member. The light emitting chip 25 may be connected to at least one of the first and second lead frames 21 and 23 by a connecting member 27, but is not limited thereto. The connection member 27 includes a wire made of a conductive material, for example, a metal material.

The light emitting chip 25 emits light with a peak wavelength in the range of 400 nm to 600 nm in the wavelength range of visible light. The light emitting chip 25 may emit blue peak wavelength. The light emitting chip 25 may emit light with a blue peak wavelength, for example, a peak wavelength ranging from 400 nm to 470 nm. As another example, the light emitting chip 25 may emit ultraviolet light, but is not limited thereto.

The light emitting chip 25 may include at least one of a group II-VI compound and a group III-V compound. The light emitting chip 25 may be formed of, for example, a compound selected from the group consisting of GaN, AlGaN, InGaN, AlInGaN, GaP, AlN, GaAs, AlGaAs, InP, and mixtures thereof.

A molding member 41 is disposed in the cavity 15, and the molding member 41 includes the phosphors 31 and 33 according to the embodiment. The phosphors 31 and 33 include fluorescent materials emitting different peak wavelengths. The phosphors 31 and 33 include, for example, a first phosphor 31 and a second phosphor 33 emitting light of different peak wavelengths. The first phosphor 31 may include one type or two or more types of phosphors. For example, a green phosphor that emits green light at a first peak wavelength, for example, by using the peak wavelength emitted from the light emitting chip 25 as an excitation wavelength. can include The green phosphor may emit light with a peak wavelength of 570 nm or less, for example, 540 nm to 560 nm.

The first phosphor 31 may be, for example, (Y,Gd,Lu,Tb) ₃ (Al,Ga) ₅ O ₁₂ :Ce, (Mg,Ca,Sr,Ba) ₂ SiO ₄ :Eu, (Ca,Sr) ) ₃ SiO ₅ :Eu, (La,Ca) ₃ Si ₆ N11 :Ce, α-SiAlON:Eu, β-SiAlON:Eu, Ba ₃ Si ₆ O ₁₂ N ₂ :Eu, Ca ₃ (Sc,Mg) ₂ Si ₃ O ₁₂ :Ce, CaSc ₂ O ₄ :Eu, BaAl ₈ O ₁₃ :Eu, (Ca,Sr,Ba)Al ₂ O ₄ :Eu, (Sr,Ca,Ba)(Al,Ga,In) ₂ S ₄ :Eu, (Ca,Sr) ₈ (Mg,Zn)(SiO ₄ ) ₄ C _l2 :Eu/Mn, (Ca,Sr,Ba) ₃ MgSi ₂ O ₈ :Eu/Mn, (Ca,Sr, Ba) ₂ (Mg,Zn)Si ₂ O ₇ :Eu, Zn ₂ SiO ₄ :Mn, (Y,Gd)BO ₃ :Tb, ZnS:Cu,Cl/Al, ZnS:Ag,Cl/Al, (Sr ,Ca) ₂ Si ₅ N ₈ :Eu, (Li,Na,K) ₃ ZrF ₇ :Mn, (Li,Na,K) ₂ (Ti,Zr)F ₆ :Mn, (Ca,Sr,Ba)( Ti,Zr)F ₆ :Mn, Ba _{0 . 65} Zr _0.35 F _{2. 7} :Mn, (Sr,Ca)S:Eu, (Y,Gd) _{BO 3} :Eu, (Y,Gd)(V,P)O ₄ :Eu, Y ₂ O ₃ :Eu, (Sr,Ca,Ba,Mg) ₅ (PO ₄ ) ₃ Cl:Eu, (Ca,Sr,Ba)MgAl ₁₀ O ₁₇ :Eu, (Ca,Sr,Ba)Si ₂ O ₂ N ₂ : One type or two or more types may be selected from among Eu, 3.5MgO·0.5MgF ₂ ·GeO ₂ :Mn, and the like. The first phosphor 31 may include a quantum dot, and the quantum dot may include a II-VI compound or a III-V compound semiconductor, and may emit green light. The quantum dots may be, for example, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, GaN, GaP, GaAs, GaSb, InP, InAs, In,Sb, AlS, AlP, AlAs, PbS, PbSe, Ge, Si, CuInS ₂ , CuInSe ₂ and the like, and combinations thereof.

The second phosphor 33 may emit light of a second peak wavelength, for example, a red peak wavelength, by using the light emitted from the light emitting chip 25 as an excitation wavelength. The second phosphor 33 may include a phosphor of a fluoride compound, for example, at least one of an MGF-based phosphor, a KSF-based phosphor, or a KTF-based phosphor. The MGF-based phosphor has a composition formula of, for example, Mg ₄ Ge _{1 - x} O _y F:Mn ^{4 +} _x , where x satisfies 0.001 ≤ x ≤ 0.1, and y may satisfy 1 ≤ y ≤ 5. The KSF-based phosphor, for example, may have a composition formula of K _a Si _{1 -c} F _b :Mn ⁴⁺ _c , wherein a is 1 ≤ a ≤ 2.5, b is 5 ≤ b ≤ 6.5, and c is 0.001 ≤ c ≤ 0.1 can be satisfied. The KTF-based phosphor, for example, may have a compositional formula of K _d Ti _1-g F _e :Mn ⁴⁺ _g , wherein d is 1 ≤ d ≤ 2.5, e is 5 ≤ e ≤ 6.5, and g is 0.001 ≤ g ≤ 0.1 can be satisfied. The second phosphor 33 is a fluoride compound phosphor, which is an Mn ⁴⁺ activator phosphor, and has high luminous efficiency and strong absorption at a blue peak wavelength. The second phosphor 33 may include ^a sulfide phosphor such as (Ca,Sr)S:Eu ²⁺ or a nitride phosphor such as CaAlSiN ₃ :Eu ²⁺ . The activator may be a tetravalent transition metal ion such as Mn ⁴⁺ , or a metal ^ion selected from various rare earth ions or transition metal ions ^, if necessary, and may be appropriately selected, for example, Eu ²⁺ _, Ce ³⁺ , Pr Trivalent ^rare earth ^metal ions ^{such as 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Tb 3+ , Dy 3+ , Ho 3+ ,} Er ^{3+ ,} Tm ^{3+ ,} Yb ^{3+ ,} divalent rare ^earth metal ions such ^as Sm ²⁺ , Eu ²⁺ , ^{and Yb 2+} , ^divalent transition metal ions such as Mn ²⁺ , and trivalent transition metal ions such as Cr ^{3+ and} Fe ³⁺ .

The second phosphor 33 may use the blue wavelength emitted from the light emitting chip 25 as an excitation wavelength to emit red light, eg, a long wavelength among red peak wavelengths. The second peak wavelength emitted from the second phosphor 33 may emit light having a peak wavelength of 645 nm or more, for example, 650 nm to 670 nm.

In an embodiment, a white light emitting device may be implemented by combining blue light emitted from the light emitting chip 25 , green light from the first phosphor 31 , and red light from the second phosphor 33 . Since such a white light emitting device does not use a separate yellow phosphor, color reproducibility can be increased.

The white light according to the embodiment may be formed by a combination of blue, green, and red spectra emitted from one or a plurality of light emitting elements or a lighting device having the light emitting elements. In addition, a light emitting element or a lighting device having the light emitting device according to an embodiment may provide a lighting system including a light emitting chip 25 made of a semiconductor and two or more types of phosphors 31 and 33 for converting wavelengths of some light emitted through the light emitting chip 25 . there is.

In an embodiment, white light emitted from a light emitting device may give a similar or brighter and clearer feeling than a color sample of sunlight, and may show improved color contrast than a general fluorescent lamp or black body light source. Accordingly, the white light according to the embodiment may have a color expression with improved color difference or saturation compared to the black body light source. The chromaticity locus of the blackbody light source is a Planckian locus, and a light source represented by a point on this locus can be specified by a color temperature in Kelvin units. General lighting generally has a color temperature between 2000K and 10000K, and many lighting devices for general lighting have color temperatures between 2700K and 6500K.

Color reproduction by a light emitting element or lighting device is usually measured using a color rendering index (CRI) or an average color rendering index (CRI Ra). In the calculation of the CRI, the color appearance of the 14 reflective samples when illuminated by a reference illuminant and a test source is simulated. The difference in color appearance, for each sample, between test and reference illumination, ΔEi is calculated in the CIE 1964 W*U*V uniform color space. Thus, it provides a measure of the relative shift in surface color and luminance of an object when illuminated by a particular lamp. The general color rendering index CRI Ra is a modified average using the first eight indices, all of which have low to medium chromatic saturation. The CRI Ra is 100 if the color coordinates and relative luminance of a set of test colors illuminated by the illumination system are identical to the coordinates of the same test color illuminated by the reference emitter. Daylight has a high CRI (Ra of about 100), fluorescent lamps also have Ra greater than 95, and fluorescent lighting can have Ra of 70-80 for general lighting where the color of the object is not important. . Also for normal interior lighting, CRI Ra > 80 is acceptable, CRI Ra > 85 or higher, eg CRI Ra > 90, provides higher color quality. This CRI only evaluates color rendering, or color fidelity, and ignores other aspects of color quality, such as color discrimination and observer preference.

The Color Quality Scale (CQS) developed by the National Institute of Standards and Technology (NIST) covers these different aspects of color appearance and is designed to address many of the shortcomings of CRI, especially for solid-state lighting. there is. The method for calculating CQS is based on modifications to the method used for CRI and uses a set of 15 Munsell samples with much higher chroma than the CRI index.

White light emitted from a light emitting element or lighting device has a delta chroma (ΔC: Δ-chroma) value for each of 15 color samples of a color quality scale (CQS) preselected for correlated color temperature. . The saturation value of this color quality scale (CQS) is measured in the CIE L ^* a ^* b ^* color space as shown in FIG. 11 . This saturation value can be measured by conventional techniques, for example in the CIE L ^* a ^* b ^* color space. For example, the CIE 1976 a,b chroma value can be calculated as ^{C *} _ab = [(a ^* ) ² + (b ^* ) ² ] ^1/2 . The L ^* represents reflectance (or brightness), C ^* represents saturation, the center is 0 and the number gradually increases toward the periphery, a ^* is a chromaticity diagram, +a ^* is red, -a ^* is green direction indicates b ^* is the chromaticity diagram, +b ^* indicates the direction of yellow and -b ^* indicates the direction of blue.

The Color Quality Scale (CQS) uses 15 Munsell color samples to evaluate various aspects of the color of an object illuminated by a light source, similarly performed by the Color Rendering Index (CRI). ) is used. However, color rendering index (CRI) systems utilize 14 standard color samples (generally denoted R1-R14 or Ri) to evaluate color rendering. Typically, if the color rendering score according to the color rendering index (CRI) is conveyed, it is the general color rendering index" (referred to as Ra), and it is the average of the Ri values for all 8 samples. However, The color rendering index (CRI) system that measures the target color has a disadvantage that the red region of the color space is not uniform, that is, a high color rendering index light source prioritizes the CRI value and light efficiency, so short-wavelength red light of 640 nm or less It is designed so that there is no characteristic of strength and weakness for all wavelengths, so when red, green, and blue are expressed to a degree similar to sunlight, there is a problem that it looks slightly dark and cloudy.

6 is a diagram showing a color sample and a color difference between a reference light source (ref) and a fluorescent lamp as a test sample in the CIE color space, wherein the reference light source is a blackbody light source or a solar light source. In FIG. 6, the color difference between the reference light source and the fluorescent lamp in each color sample is TCS (Test color sample) 01 to TCS 14, and white indicates a value of ΔE*ab. Here, the color difference ΔE*ab of red is obtained as a value of 21.9, and the value of ΔE*ab of blue is obtained as a value of 7.1. The color difference of each color sample may be obtained as ΔE ^* _ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 .

7 is a diagram showing color samples and differences between a reference light source and a CRI 90 LED in the CIE color space, wherein the reference light source is a blackbody light source or a solar light source, and the test light source is a CIR 90 LED. In FIG. 7, the color difference between the reference light source and the CIR 90 LED in each color sample is TCS (Test color sample) 01 to TCS 14, and white is obtained as a value of ΔE ^* _ab . At this time, the color difference of red is ΔE ^* _ab of 4.0 As a value, it has a smaller value than the fluorescent lamp and is expressed darker and more turbid than the color sample of the fluorescent lamp, and ΔE ^* _ab of blue has a value of 9.0, which is higher than that of the fluorescent lamp and is expressed brighter than the color sample of the fluorescent lamp. . In this case, a CRI 90 LED uses a wavelength of 640 nm or less to consider a CRI of 90 or more Ra and light efficiency, so when an object is illuminated using the same light as the red color sample (TCS 09), the object appears dark and hazy. there is a problem When a lighting device using such a CRI 90 LED illuminates a specific object, such as meat, fruit and vegetables, or fish, it may appear dark and cloudy, which may act as a rejection of the object.

In an embodiment, in order to solve the above problem, when blue, green, and red lights are projected on an object by white light emitted from a light emitting device, it can be expressed more brightly and vividly. For example, red light emitted from the light emitting element emits a peak wavelength of a long wavelength, for example, 645 nm or more, for example, 650 nm to 670 nm. Accordingly, compared to CRI 90 LEDs that use light of 640 nm or less, it can be expressed more clearly and brighter than red reflected on an object. In addition, green light emitted from the light emitting device emits a long wavelength, for example, a peak wavelength in the range of 540 nm to 560 nm, so that green light reflected on an object can be expressed more brightly and vividly. The color temperature of white light according to the embodiment may have a color temperature of pure white, for example, in a range of 4500K to 5500K.

8 is a diagram showing a color sample and a chroma difference between a reference light source and a light emitting device according to Example 1 in a CIE color space, wherein the reference light source is a blackbody light source or a solar light source, and a test light source is a light emitting device according to Example 1 This is the case when the red wavelength is used in the range of 650 nm ± 5 nm.

9 is a view showing color samples and color differences between a reference light source and a light emitting device according to Example 2 in a CIE color space, wherein the reference light source is a black body light source or a solar light source, and a test light source is a light emitting device according to Example 2 and has a red wavelength This is the case of using the range of 660 nm ± 5 nm.

8 and 9, the color difference of blue light emitted from the light emitting device of the embodiment has a value of 6 to 9 compared to the black body light source in the color space, and the color difference of red light has a value of 3 to 6 compared to the black body light source in the color space. can For example, looking at the red color sample (TCS 09), the color difference ΔE ^* _ab of the red color sample (TCS 09) of Example 1 is 3.3±0.2, which is similar to that of the sunlight source, and the red color sample of Example 2 ( The color difference ΔE ^* _ab of TCS 09) is obtained as 5.8±0.2, and it can give a brighter and clearer feeling than a blackbody light source. Looking at the blue color sample (TCS 12), the color difference ΔE ^* _ab of the blue color sample (TCS 12) of Example 1 is obtained as 8.9 ± 0.2, and the color difference ΔE ^* _ab of the blue color sample (TCS 09) of Example 2 can be obtained as 6.7±0.2. The closer the color difference value is to 0, the color similar to that of the sunlight source is obtained, and the larger the color difference value is, the more vivid the color can be expressed. At this time, since the red wavelength of Examples 1 and 2 uses a long wavelength, a brighter color can be expressed compared to the CRI 90 LED.

10 is a diagram comparing wavelength spectra of a fluorescent lamp, a CRI 90 LED of a comparative example, and a light emitting device according to Examples 1 and 2. Here, in Example 1, the red wavelength R1 may have a range of 650 nm ± 5 nm, and in Example 2, the red wavelength R2 may have a range of 660 nm ± 5 nm. It can be seen that the luminous intensity of the red wavelengths (R1 and R2) of Examples 1 and 2 is higher than that of the CRI 90 LED at long wavelengths.

11 is a diagram showing the CIE L * a * b * color space, where the saturation is higher as the center is located at the edge, the center is 0 and the number gradually increases toward the periphery, a ^* is a chromaticity diagram, +a ^* represents the red direction and -a ^* represents the green direction. b ^* is the chromaticity diagram, +b ^* indicates the direction of yellow and -b ^* indicates the direction of blue.

The embodiment may use a color quality scale (CQS) to indicate a degree of brightness greater than that of a sunlight source in a color space. The color quality measure overcomes the disadvantages of the color rendering index (CRI) system, and the overall Qa including the color representation of a total of 15 color samples having a relatively high color saturation (chroma) and being approximately evenly distributed in the color space. use the value The Qa value typically corresponds to the average of the individual Color Quality Scale (CQS) values for each of the 15 color samples. 12 illustrates color samples VS1 to VS15 and color quality scales according to a reference light source and a correlated color temperature (CCT) value of a light emitting device according to an embodiment. As shown in FIG. 12, it can be seen that the red color sample (VS14) has a significantly higher correlation color temperature of 4500K to 5500K.

When a saturation value of each color is generated from the color temperature and chromaticity coordinates of the white light emitted from the light emitting device according to the embodiment, the saturation value may be compared with a reference saturation value for each color value of the reference light source. At this time, the reference light source is a black body light source or a solar light source, and the chroma difference between the reference light source and the white light of the light emitting device according to the embodiment, that is, the delta saturation value is the arithmetic value of the saturation value of the reference light source and the saturation value according to the embodiment. difference can be obtained.

Table 1 is a fluorescent lamp, a CRI 90 LED, chromaticity diagrams (Ref_a ^* , Ref_b ^* ) of reference light sources of Examples 1 and 2, chromaticity diagrams (a ^* , b ^* ) of light emitting devices according to Examples, delta chroma ( This is a table showing C ^* _ab ) values.

type Ref_a ^* Ref_b ^* a ^* b ^* C ^* _ab fluorescent lamp 47.66 3.07 65.13 7.23 17.77 CRI90 LEDs 47.06 2.11 45.28 1.43 -1.80 Example 1 46.89 2.92 48.47 3.63 1.63 Example 2 47.63 3.02 51.46 3.89 3.88

As shown in Table 1, it can be seen that the delta saturation value has a value of 0 or more, for example, between 1 and 4, and has a large difference compared to the CRI 90 LED, and as in Example 1, the red wavelength ranges from 650 nm ± 5 nm It can be seen that the delta saturation value is 1 or more, and the delta saturation value is 3 or more when the red wavelength is in the range of 660 nm ± 5 nm, as in Example 2. Accordingly, when white light is projected onto an object, red light may be projected in a more vivid color.

13 is a diagram comparing the chroma difference between the reference light source and the light emitting device (Test) according to the embodiment, and it can be seen that the delta chroma ((C ^* _ab ) _CQS14 of red (VS14) remains relatively large.

In the embodiment, blue, green, and red of white light obtained by mixing blue light emitted from a blue light emitting chip, green long-wavelength light from the first phosphor, and red long-wavelength light from the second phosphor are brighter and more vivid colors. can be projected onto an object. In particular, objects such as meat, fruits and vegetables, and fish can be illuminated with sharper and brighter colors.

2 is a view showing another example of a light emitting device having a phosphor according to an embodiment. In describing FIG. 2 , the description of FIG. 1 will be referred to for the same parts as in FIG. 1 .

Referring to FIG. 2 , the light emitting device may include a plurality of molding members 42 and 43 in the cavity 15 of the body 11 . The phosphors 31 and 33 may be disposed on any one of the plurality of molding members 42 and 43 . The plurality of molding members 42 and 43 include first and second molding members 42 and 43 , and the phosphors 31 and 33 may be disposed on the second molding member 43 . Looking at the thickness ratio of the first and second molding members 42 and 43, it may be in the range of 2:1 to 1:3, and when the thickness ratio of the second molding member 43 is smaller than the above range, transmission The ability to dissipate heat may be lowered, and if it is greater than the above range, there is a problem that the thickness of the light emitting element 10 may become thick.

The phosphors 31 and 33 may be spaced apart from the light emitting chip 25 . The second molding member 43 may have a distance of 0.2 mm or more from the light emitting chip 25, and when the distance is smaller than 0.2 mm, degradation of the phosphor may occur. A phosphor, for example, any kind of phosphor may not be added to the first molding member 42 that comes into contact with the light emitting chip 25 . First and second phosphors 31 and 33 may be added to the second molding member 43 disposed on the first molding member 42 . Accordingly, damage caused by heat generated from the light emitting chip 25 to the first and second phosphors 31 and 33 can be reduced.

The first molding member 42 and the second molding member 43 may include the same resin material, for example, silicone or epoxy. The characteristics of the first and second phosphors 31 and 33 will be referred to the description of the embodiment. The light emitting device according to the embodiment has a high color gamut compared to a configuration using a yellow phosphor and can provide a color gamut equal to that of the case of using a red/green/blue chip, and in particular, provides darker and more vivid green and red colors. can do.

3 is a view showing another example of a light emitting device having a phosphor according to an embodiment. In the description of FIG. 3 , the same parts as the configuration disclosed above will be referred to the description disclosed above.

Referring to FIG. 3 , the light emitting device may include a plurality of molding members 44 , 45 , and 46 in the cavity 15 of the body 11 . Different types of phosphors 31 and 33 may be added to at least two of the plurality of molding members 45 and 46 .

The cavity 15 may include a first molding member 44, a second molding member 45 on the first molding member 44, and a third molding member 46 on the second molding member 45. can The first molding member 44 is in contact with the light emitting chip 25, and any kind of phosphor may not be added therein. The first phosphor 31 may be added to the second molding member 45 and the second phosphor 33 may be added to the third molding member 46 .

Looking at the thickness ratio of the first to third molding members 44, 45, and 46, it may be in the range of 2:1:1 to 3:1:1. The thickness of the second molding member 45 may be thicker or thinner than the thickness of the first molding member 44 and may be the same as or different from the thickness of the third molding member 46 . If the thickness ratio of the first molding member 43 is smaller than the above range, the ability to dissipate the transferred heat may deteriorate, causing a problem that a lot of heat may be transferred to the phosphor. There is a problem that the thickness of (10) can be thick.

The first to third molding members 44, 45, and 46 may be formed of the same light-transmitting resin material or a resin material having a different refractive index, but are not limited thereto. The characteristics of the first and second phosphors 31 and 33 will be referred to the description of the embodiment.

As another example, when a plurality of molding members 44 , 45 , and 46 are disposed in the cavity 15 , a phosphor having a low peak wavelength among the first and second phosphors 31 and 33 , for example, the first phosphor 31 ) may be added to the molding member positioned lower than the molding member to which the second phosphor 33 is added. Alternatively, among the first and second phosphors 31 and 33, a phosphor having a high peak wavelength, for example, the second phosphor 33 is added to a molding member positioned lower than the molding member to which the first phosphor 31 is added. It can be. In addition, each of the phosphors 31 and 33 may be adjacent to the upper surface or distributed on the lower surface of each of the molding members 45 and 46, but is not limited thereto. The light emitting device according to the embodiment has a high color gamut compared to a configuration using a yellow phosphor and can provide a color gamut equal to that of the case of using a red/green/blue chip, and in particular, provides darker and more vivid green and red colors. can do.

4 is a view showing another example of a light emitting device having a phosphor according to an embodiment. In describing FIG. 4 , the same configuration as the above embodiment will refer to the description disclosed above.

Referring to FIG. 4 , the light emitting device may include a molding member 49 in a cavity 15 of a body 11 and a film 30 having phosphors 31 and 33 on the body 11. .

Any kind of phosphor may not be added to the molding member 49 . Accordingly, the heat generated from the light emitting chip 25 can reduce the effect on the phosphors 31 and 33 .

The film 30 is a transparent film and includes a resin material such as silicone or epoxy. The content of the phosphors 31 and 33 in the film 30 will refer to the description of the embodiment disclosed above. The film 30 may include a glass material on which phosphors 31 and 33 are coated on the upper and/or lower surfaces. The film 30 may have an area larger than the area of the top surface of the molding member 49, and thus, wavelength conversion efficiency by the phosphors 31 and 33 therein may be improved. The film 30 may be fixed in contact with the exit surface of the molding member 49 . The width of the film 30 may be narrower than the sum of the widths of the lead frames 21 and 23 at the side cross section and may be narrower than the width of the body 11 . When the width of the film 30 is exposed to the outside of the body 11, there is a problem in that light loss may occur. The film 30 may be attached to the upper surface of the body 11 with an adhesive.

The phosphors 31 and 33 may include first and second phosphors 31 and 33 emitting different peak wavelengths. For the first and second phosphors 31 and 33, the description disclosed in the embodiment will be referred to. Since the first and second phosphors 31 and 33 are spaced apart from the light emitting chip 25 , the wavelength of light emitted through the emission surface of the molding member 49 may be converted.

5 is a view illustrating a lighting device having a phosphor according to an embodiment.

Referring to FIG. 5 , in the lighting device, one or a plurality of light emitting chips 25 and 25A are disposed on a circuit board 50, and a reflective member 55 is disposed around the light emitting chips 25 and 25A. , A film 30A having phosphors 31 and 33 may be disposed on the light emitting chips 25 and 25A. The width of the film 30A may be wider than the area 60 between the reflective members 55 in the side cross section and may be narrower than the width of the reflective members 55 . When the width of the film 30A is larger than the width of the reflective member 55, it may be exposed to the outside and thus light loss may occur.

The circuit board 50 may have a circuit pattern and be electrically connected to the light emitting chips 25 and 25A. When the plurality of light emitting chips 25 and 25A are disposed on the circuit board 50, the plurality of light emitting chips 25 and 25A may be connected in series or in parallel. The plurality of light emitting chips 25 and 25A may emit light of the same blue peak wavelength or different blue peak wavelengths.

The circuit board 50 may be a printed circuit board (PCB) including a circuit pattern (not shown). However, the circuit board 50 may include not only a general PCB, but also a metal core PCB (MCPCB), a flexible PCB (FPCB), and the like, but is not limited thereto. A reflective material is disposed on the upper surface of the circuit board 50 to reflect light.

The reflective member 55 may include a reflective material, for example, a silicone-based, epoxy-based, or plastic material, and may be formed of a thermosetting resin or a material with high heat resistance and high light resistance. In addition, an acid anhydride, an antioxidant, a release agent, a light reflector, an inorganic filler, a curing catalyst, a light stabilizer, a lubricant, and titanium dioxide may be selectively added to the reflective member 55 . The reflective member 55 may be disposed around the outer circumference of the light emitting chips 25 and 25A to reflect the light emitted from the light emitting chips 25 and 25A.

The region 60 between the circuit board 50 and the film 30A is a transparent region and may be formed of a material that transmits light. The light-transmitting material may include air or a resin material such as silicone or epoxy. The film 30A may be disposed on the transparent region 60 . The film 30A may come into contact with the resin material when the transparent region 60 is filled with the resin material.

The film 30A is a transparent film and includes a resin material such as silicone or epoxy. The film 30A may include a glass material on which the phosphors 31 and 33 are applied above and/or below. The film 30A may further extend on the reflective member 55 to improve wavelength conversion efficiency by the phosphors 31 and 33 therein.

The light emitting chips 25 and 25A may emit blue light. The phosphors 31 and 33 include first and second phosphors 31 and 33, and the first and second phosphors 31 and 33 may include the phosphor disclosed in the embodiment, see the description disclosed above. I'm going to do it. The light unit according to the embodiment has a high color gamut compared to a configuration using a yellow phosphor and can provide a color gamut equal to that of the case of using a red/green/blue chip, and in particular, provides darker and more vivid green and red. can do.

An optical lens that converts a beam angle of light may be disposed on the molding member or the film according to the embodiment. The optical lens may change a path of the light emitted through the molding member or the film and radiate the light with a desired beam angle distribution.

<Lighting system>

A light emitting element or lighting device according to an embodiment may be applied to a lighting system. The lighting system includes a structure in which a plurality of light emitting devices are arrayed, and includes the lighting device shown in FIG. 14 , and may include a lighting lamp, a traffic light, a vehicle headlight, an electronic display board, and the like.

14 is an exploded perspective view of a lighting device having a light emitting device according to an embodiment.

Referring to FIG. 14 , the lighting device according to the embodiment may include a cover 2100, a light source module 2200, a radiator 2400, a power supply unit 2600, an inner case 2700, and a socket 2800. can In addition, the lighting device according to the embodiment may further include any one or more of the member 2300 and the holder 2500 . The light source module 2200 may include a light emitting device according to an embodiment.

For example, the cover 2100 may have a bulb or hemispherical shape, be hollow, and may be provided in a shape in which one portion is open. The cover 2100 may be optically coupled to the light source module 2200 and coupled to the heat dissipation body 2400 . The cover 2100 may have a coupling portion coupled to the heat dissipation body 2400 .

An inner surface of the cover 2100 may be coated with a milky white paint having a diffusion material. The light from the light source module 2200 can be scattered and diffused and emitted to the outside by using such a milky white material.

The material of the cover 2100 may be glass, plastic, polypropylene (PP), polyethylene (PE), or polycarbonate (PC). Here, polycarbonate is excellent in light resistance, heat resistance, and strength. The cover 2100 may be transparent or opaque so that the light source module 2200 can be seen from the outside. The cover 2100 may be formed through blow molding.

The light source module 2200 may be disposed on one surface of the heat dissipation body 2400 . Thus, heat from the light source module 2200 is conducted to the heat sink 2400 . The light source module 2200 may include a light emitting element 2210, a connection plate 2230, and a connector 2250.

The member 2300 is disposed on the upper surface of the radiator 2400 and has guide grooves 2310 into which a plurality of lighting elements 2210 and a connector 2250 are inserted. The guide groove 2310 corresponds to the board and connector 2250 of the lighting device 2210 .

The surface of the member 2300 may be coated or coated with a white paint. The member 2300 reflects light that is reflected on the inner surface of the cover 2100 and returns toward the light source module 2200 toward the cover 2100 again. Accordingly, light efficiency of the lighting device according to the embodiment may be improved.

The member 2300 may be made of, for example, an insulating material. The connection plate 2230 of the light source module 2200 may include an electrically conductive material. Accordingly, electrical contact may be made between the radiator 2400 and the connection plate 2230 . The member 2300 may be made of an insulating material to block an electrical short between the connection plate 2230 and the radiator 2400 . The radiator 2400 receives heat from the light source module 2200 and heat from the power supply unit 2600 and dissipates the heat.

The holder 2500 blocks the receiving groove 2719 of the insulating part 2710 of the inner case 2700. Thus, the power supply unit 2600 accommodated in the insulation unit 2710 of the inner case 2700 is sealed. The holder 2500 has a guide protrusion 2510 . The guide protrusion 2510 may have a hole through which the protrusion 2610 of the power supply unit 2600 passes.

The power supply unit 2600 processes or converts an electrical signal received from the outside and provides it to the light source module 2200 . The power supply unit 2600 is accommodated in the receiving groove 2719 of the inner case 2700, and is sealed inside the inner case 2700 by the holder 2500.

The power supply unit 2600 may include a protrusion 2610, a guide unit 2630, a base 2650, and an extension unit 2670.

The guide part 2630 has a shape protruding outward from one side of the base 2650 . The guide part 2630 may be inserted into the holder 2500 . A plurality of components may be disposed on one surface of the base 2650 . A plurality of parts may include, for example, a DC converter, a driving chip for controlling driving of the light source module 2200, an electrostatic discharge (ESD) protection element for protecting the light source module 2200, and the like. not limited to

The extension part 2670 has a shape protruding outward from the other side of the base 2650 . The extension part 2670 is inserted into the connection part 2750 of the inner case 2700 and receives an electrical signal from the outside. For example, the width of the extension part 2670 may be equal to or smaller than the width of the connection part 2750 of the inner case 2700 . The extension part 2670 may be electrically connected to the socket 2800 through a wire.

The inner case 2700 may include a molding part together with the power supply part 2600 therein. The molding part is a part where the molding liquid is hardened, and allows the power supply part 2600 to be fixed inside the inner case 2700 .

In the display device or lighting system according to the embodiment, by including the red and green phosphors disclosed in the embodiment, the color purity of red and green can be expressed more realistically, thereby improving the color reproduction rate in the lighting or display device. can

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

Although the above has been described centering on the embodiment, this is only an example and does not limit the embodiment, and those skilled in the art in the field to which the embodiment belongs may find various things not exemplified above to the extent that they do not deviate from the essential characteristics of the embodiment. It will be appreciated that variations and applications of branches are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the embodiments set forth in the appended claims.

10: light emitting element 11: body
15: cavity 21: first lead frame
23: second lead frame 25, 25A: light emitting chip
41: molding member 30,30A: film
31: first phosphor 33: second phosphor

Claims (11)

a light emitting chip that emits blue light;
a first phosphor absorbing the light emitted from the light emitting chip at an excitation wavelength and emitting light of a first peak wavelength of green; and
a second phosphor absorbing the light emitted from the light emitting chip at an excitation wavelength and emitting a second peak wavelength of red;
The second peak wavelength is 645 nm or more,
In the white light in which the blue light, green light, and red light are mixed, the red light has a delta saturation value of zero (0) or more compared to a preselected color quality scale (CQS), and ,
The color temperature of the white light has a range of 4500K to 5500K,
The delta saturation value has a range of 1 to 4 for a red sample (VS14) among 15 color samples of a preselected color quality scale. According to claim 1,
The light emitting chip emits light with a peak wavelength in the range of 400 nm to 470 nm,
The first peak wavelength has a range of 540 nm to 560 nm,
The second peak wavelength is a light emitting device having a range of 650nm to 670nm. According to claim 1 or 2,
The color difference of the blue light has a value of 6 to 9 compared to the black body light source in the color space,
The color difference of the red light has a value of 3 to 6 compared to a black body light source in a color space. According to claim 1 or 2,
a plurality of lead frames disposed below the light emitting chip;
a body coupled to the plurality of lead frames and disposed around the light emitting chip; and
It includes a molding member or film having the first and second phosphors,
The body has a cavity, and the light emitting chip is disposed in the cavity.
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