JP2008218486A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device that can keep a high color rendering property, establish high light emission efficiency and emit light with optional chrominance. <P>SOLUTION: The light emitting device is provided with a substrate and three or more groups that are arranged on the substrate in a specified pattern and emit monochromatic light, respectively. One of the light emitting groups is provided with a plurality of light emitting elements that are arranged on the substrate to emit blue light and a transparent resin layer that is covered on the light emitting element. Each of the other light emitting groups other than the light emitting group with the transparent resin layer is provided with: a plurality of light emitting elements that are arranged on the substrate to emit a blue light; and a phosphor layer containing a such phosphor that emits visible light by using the blue light radiated from the light emitting elements covered on the light emitting element and has the same kind and mixing ratio at each of the light emitting groups. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting device such as a light emitting diode.

  LED lamps using light emitting diodes (LEDs) are rapidly expanding in various fields such as backlights for liquid crystal displays, mobile phones, information terminals, and indoor / outdoor advertisements. In addition, LED lamps have features such as long life and high reliability, and low power consumption, impact resistance, high purity display color, lightness, thinness, and other features. Application of is also being attempted. When such an LED lamp is applied to various uses, it is important to obtain white light emission.

Typical methods for realizing white light emission with an LED lamp are (1) a method using three LED chips that emit light in blue, green and red colors, and (2) a blue light emitting LED chip and yellow or orange light emission. And (3) a method of combining an ultraviolet light emitting LED chip and a blue, green and red light emitting three-color mixed phosphor. Of these, the method (2) is generally widely used. And as a structure of the LED lamp to which the above-mentioned method (2) is applied, a transparent resin mixed with a phosphor is poured into a cup-shaped frame equipped with an LED chip, and this is solidified to contain the phosphor. A structure in which a resin layer is formed is common (see, for example, Patent Document 1). In addition to the above-mentioned bullet-type LED elements and SMD (Surface Mounting Device) type, a chip-on-board (COB) with multiple chips mounted on a substrate (board) has been developed for the purpose of increasing brightness. Has been. The characteristics required for general illumination include color rendering as an index of color appearance, in particular average color rendering index Ra, in addition to high efficiency (light emission efficiency) as an LED lamp. For this color rendering property, lineups such as Ra 80 to 85 and Ra 90 or higher which are similar to fluorescent lamps are required.

  Color rendering is an evaluation of the color appearance of a light source using illumination close to natural light as the reference light, and the color shift when the test color specified in JIS is illuminated with the sample light source and the reference light, respectively. The numerical value of the size is the color rendering index. The color rendering index includes an average color rendering index Ra and a special color rendering index Ri. It is expressed as an average value of 1 to 8 color rendering evaluation values. The special color rendering index Ri is the test No. Expressed as individual special color rendering evaluation values of 9 to 15. The color rendering index Ra is an index indicating whether the color of the white light source that is the reference light source is faithfully reproduced. As a rule, the color rendering index Ra is better as it is closer to 100.

  In general, a so-called high color rendering type LED lamp having a high average color rendering index Ra has a yellow emission from a yellow phosphor such as YAG that emits light of a wavelength of 540 nm to 560 nm by a blue emission from an LED chip, and a wavelength of 620 nm. The white light with excellent color rendering properties is synthesized by the red light emitted from the red light emitter that emits the light. In order to increase the average color rendering index Ra, it is usual to use a red phosphor that emits red light as described above. The red phosphor not only uses blue light near 460 nm for excitation, but also a green phosphor. The green light emitted from the LED and the yellow light emitted from the yellow phosphor are also used for excitation. Therefore, when the red light-emitting phosphor is used, the luminous efficiency of the LED lamp is reduced to about half, and there is a problem that it is greatly reduced. .

  Therefore, it has been attempted to use a light emitting element that emits red light instead of a phosphor emitting red light. However, since the red light emitted from the light emitting element is not broad light emission and has a narrow half width, the color temperature can be reduced, but the increase range of the average color rendering index Ra is small. Therefore, it is difficult to achieve an average color rendering index Ra85 or 90 or higher, which is a high color rendering property.

In addition, regarding the light color, that is, the color temperature, in consideration of HID lamps, light bulbs, and fluorescent lamps, a lineup up to various color temperatures of 6700K, 5000K, 4200K, and 3000K (2850K) is required. In general, in order to cope with such a lineup, a white LED lamp corresponding only to each color temperature is required. On the other hand, a variable color LED lamp has been proposed (see, for example, Patent Document 2). However, since such a variable color LED is only a variable color in one direction by adjustment from the white LED, the color deviation (DUV) shifts and deviates from black body radiation, and the color temperature changes. In addition, there is a problem that the quality of the color is lowered due to the change in deviation. Therefore, it is necessary to realize not only a variable color in one direction but also a variable color in a desired (arbitrary) direction.
JP 2001-148516 A JP 2005-1000079 A

  The present invention has been made to solve such a problem, and it is possible to obtain high light emission efficiency while maintaining high color rendering properties, and to achieve light emission with a desired chromaticity. The object is to provide a device.

  The light-emitting device according to claim 1 is a substrate; and three or more light-emitting unit groups arranged in a predetermined arrangement pattern on the substrate and each emitting monochromatic light, and one of the light-emitting unit groups includes: A light emitting element group having a plurality of light emitting elements that emit blue light disposed on the substrate, a transparent resin layer coated on the light emitting element, and a light emitting part group other than the light emitting part group having the transparent resin layer, A plurality of light emitting elements that emit blue light disposed on the substrate, and a phosphor that emits visible light by the blue light that is coated on the light emitting elements, and the type and composition of each light emitting unit group And a light emitting unit group having a phosphor layer containing phosphors having the same ratio.

  The light emitting device according to claim 2 is the light emitting device according to claim 1, wherein the light emitting unit group other than the light emitting unit group having the transparent resin layer is excited by the blue light emitted from the light emitting element to emit green light. A first light emitting unit group having a phosphor layer including a green phosphor that emits light; and a second phosphor layer including a yellow phosphor that emits yellow light when excited by blue light emitted from the light emitting element. And a third light emitting unit group including a phosphor layer including a red phosphor that emits red light when excited by the blue light emitted from the light emitting element.

  The light-emitting device according to claim 3 is a substrate; and three or more light-emitting unit groups each emitting monochromatic light, arranged in a predetermined arrangement pattern on the substrate, wherein the light-emitting unit group is on the substrate A phosphor layer including a plurality of light emitting elements that emit ultraviolet light and a phosphor that emits visible light by the ultraviolet light, and a phosphor having the same type and mixing ratio for each light emitting unit group And a light emitting unit group having the following structure.

  The light-emitting device according to claim 4 is the light-emitting device according to claim 3, wherein the light-emitting unit group includes a blue phosphor that emits blue light when excited by ultraviolet light emitted from the light-emitting element. A fourth light emitting unit group having a phosphor layer including a green phosphor that emits green light when excited by ultraviolet light emitted from the light emitting device, and from the light emitting device A sixth light emitting unit group having a phosphor layer including a yellow phosphor that emits yellow light when excited by the emitted ultraviolet light, and emits red light when excited by the ultraviolet light emitted from the light emitting element. And a seventh light emitting unit group having a phosphor layer containing a red phosphor.

  A light-emitting device according to a fifth aspect is the light-emitting device according to any one of the first to fourth aspects, wherein the predetermined arrangement pattern is a line or a matrix.

  The light emitting device according to claim 6 is characterized in that in the light emitting device according to any one of claims 1 to 5, white light is emitted by light from the light emitting unit group.

  A light-emitting device according to claim 7 is the light-emitting device according to any one of claims 1 to 5, characterized in that it emits light having a variable color gamut adjusted by light from the light-emitting unit group.

  In the above-described inventions according to claims 1 to 7, the definitions and technical meanings of terms are as follows unless otherwise specified. The light emitting unit group includes a plurality of light emitting elements arranged in a predetermined arrangement pattern on a substrate and a phosphor layer including a phosphor coated on the light emitting element or a transparent resin layer not including the phosphor. .

  A light emitting element that emits blue light emits blue light having a dominant wavelength of 420 to 480 nm (for example, 460 nm), and excites a phosphor with the emitted blue light to emit visible light. Examples of the light emitting element that emits blue light used in the present invention include, but are not limited to, a blue light emitting type LED chip.

  A light emitting element that emits ultraviolet light emits ultraviolet light having a dominant wavelength of 350 to 410 nm (for example, 365 nm), and excites a phosphor with the emitted ultraviolet light to emit visible light. Examples of the light emitting element that emits ultraviolet light used in the present invention include, but are not limited to, an ultraviolet light emitting type LED chip.

  The phosphor used for the light emitting element that emits blue light emits visible light when excited by the blue light, and a desired emission color (by a color mixture of visible light and blue light emitted from the light emitting element). Single color). These phosphors include a green phosphor that emits green light when excited by the blue light, a yellow phosphor that emits yellow light when excited by the blue light, and a red light that is excited by blue light. A red phosphor can be used.

  The phosphor used for the light emitting element that emits ultraviolet light is excited by the ultraviolet light and emits visible light, and can obtain a desired emission color (single color). These phosphors include a blue phosphor that emits blue light when excited by the ultraviolet light, a green phosphor that emits green light when excited by the ultraviolet light, and emits yellow light when excited by the blue light. A yellow phosphor that emits red light when excited by the blue light can be used.

  The phosphor layer containing the phosphor is formed as a layer in which the phosphor is mixed and dispersed in addition to a transparent resin such as a silicone resin or an epoxy resin. The phosphor layer can be formed so as to cover the outside of the light emitting element, but a transparent resin layer is formed in advance so as to directly cover the light emitting element, and a layer containing the phosphor described above may be provided thereon. Is possible. In the case of emitting (emitting) blue light, only a transparent resin layer not containing a phosphor is formed instead of the phosphor layer.

  The kind and compounding ratio of the phosphors are the same for each light emitting unit group. The same type of phosphor means that the type of phosphor used, for example, the structure and composition of the phosphor are (substantially) the same. The fact that the blending ratio of the phosphors is (substantially) the same means that the blending ratio (blending amount) of the phosphors in the phosphor layer containing the phosphors is the same. Since phosphors have the same type and blending ratio for each light emitting unit group, variation in monochromatic light emission from the phosphor can be suppressed, and light emission with less variation in chromaticity and the like can be obtained from the light emitting device. Can do.

  As the arrangement pattern in which the light emitting unit group is arranged on the substrate, any arrangement pattern can be used, but a line shape or a matrix shape is preferable. By forming the phosphor layers in a line shape or a matrix shape on a plurality of light emitting elements on the same substrate, variations in phosphors for each light emitting unit group, particularly variations due to the coating amount, are further suppressed. In addition, when the arrangement pattern is a line, it is easy to make the phosphor types and mixing ratios same for each light emitting part group, and it is easy to manufacture. When the arrangement pattern is a matrix, each light emitting part group The color mixing of monochromatic light obtained from the above becomes easy. In addition, when the phosphor layer is formed in a line shape, that is, on a plurality of chips, the coating amount of the phosphor layer formed in a line shape, that is, the thickness (optical path length) is made more uniform. Can do.

  According to the light emitting device of claim 1, the phosphor can be excited for each light emitting unit group by using the blue light emitting element and each of the three or more light emitting unit groups that emit monochromatic light. Since light is obtained, it is possible to provide a light emitting device capable of obtaining high light emission efficiency while maintaining high color rendering properties and capable of emitting light of a desired chromaticity.

  According to the light emitting device of claim 3, the phosphor can be excited for each light emitting unit group by using three or more light emitting unit groups each emitting monochromatic light using an ultraviolet light emitting element. Since light is obtained, it is possible to provide a light emitting device capable of obtaining high light emission efficiency while maintaining high color rendering properties and capable of emitting light of a desired chromaticity.

  According to the light emitting device of claim 2 and 4, since the red phosphor is used in one of the light emitting unit groups in the phosphor layer coated on the light emitting element, the red phosphor is green light. In addition, it is possible to reduce the absorption of yellow light as excitation light, so that it is possible to obtain higher light emission efficiency while maintaining higher color rendering properties, and to realize light emission with a desired chromaticity. An apparatus can be provided.

  According to the light emitting device of the fifth aspect, since the predetermined arrangement pattern is a line or a matrix, and variations in phosphors are further suppressed, it is possible to obtain light emission with less variations in chromaticity and the like. .

  According to the light emitting device of the sixth aspect, it is possible to obtain white light at a desired color temperature with little deviation from black body radiation.

  According to the light emitting device of the seventh aspect, since it is possible to change the chromaticity in a desired direction, it is possible to obtain light having a desired chromaticity in which the variable color gamut is adjusted. Therefore, a lineup of variable colors in a range according to the application is possible.

  Therefore, according to the present invention, it is possible to provide a light emitting device capable of obtaining high light emission efficiency while maintaining high color rendering properties and capable of emitting light of a desired chromaticity. Also, white light at a desired color temperature with little deviation from black body radiation can be obtained. Furthermore, since it is possible to change the chromaticity in a desired direction, it is possible to obtain light of a desired chromaticity with an adjusted variable gamut, and a lineup of variable colors in a range according to the application. It becomes possible. Further, it can be used not only for illumination purposes but also as a display board or the like.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. 1 and 2 show an example of a light emitting device according to an embodiment of the present invention. FIG. 1 is a plan view of the light emitting device, and FIG. 2 is a longitudinal sectional view of the light emitting device shown in FIG. 1 cut along the line FF ′.

  A light emitting device (COB module) 1 shown in FIGS. 1 and 2 includes a package substrate, for example, a device substrate 4, and a blue light emitting unit group 2B that emits blue light and is arranged on the device substrate 4 in a predetermined arrangement pattern. A green light emitting unit group 2G that emits green light, a red light emitting unit group 2R that emits red light, a reflective layer 31, a circuit pattern 3, an adhesive layer 32, a light diffusion member 33, and a reflector 34. It is formed in preparation.

  The blue light emitting unit group 2B that emits blue light includes a plurality of blue LED chips 2 and a resin layer (transparent resin layer) 9B that does not include a phosphor. The green light emitting unit group 2G that emits green light includes a plurality of blue LED chips 2 and a green phosphor resin layer 9G containing a phosphor that is excited by the blue light and emits green light. The red light emitting unit group 2R that emits red light includes a plurality of blue LED chips 2 and a red phosphor resin layer 9R containing a phosphor that is excited by the blue light and emits red light.

  The blue LED chip 2 is mounted on a substrate 4 having a circuit pattern 3 via a reflective layer 31 and an adhesive layer 32. Circuit patterns 3 on the cathode side and the anode side are formed on the substrate 4 via the reflective layer 31, respectively. The circuit pattern 3 is made of an alloy of Cu and Ni, Au, or the like. The upper part and the peripheral part of the blue LED chip 2 are coated and filled with a phosphor-containing resin mixed and dispersed in a transparent resin, and the blue LED chip 2 is covered with such a phosphor-containing resin layer 9. . As the transparent resin, for example, a silicone resin or an epoxy resin is used.

The green phosphor that emits green light when excited by blue light is, for example, RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphor (RE represents at least one selected from Y, G, and La). YAG phosphors, AE ₂ SiO ₄ : Eu phosphors (AE represents an alkaline earth element such as Sr, Ba, and Ca) and Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce phosphors such as Ce phosphors phosphor, sialon-based phosphor _{(e.g., Ca X Si y Al Z ON} : Eu 2+), and _Ca 3 _Sc 2 _O 4: is selected from among such Ce phosphor. Examples of red phosphors that emit red light when excited by blue light include oxysulfide phosphors such as La ₂ O ₂ S: Eu phosphors and nitride phosphors (for example, AE ₂ Si ₅ N ₈ : Eu ²⁺ and CaAlSiN ₃ : Eu ²⁺ ) are used, but are not particularly limited. Examples of yellow phosphors that emit yellow light when excited by blue light include RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphors (RE represents at least one selected from Y, Gd, and La). YAG phosphors, TAG phosphors such as (Tb, Al) ₅ O ₁₂ : Ce phosphor, sialon-based phosphors (eg, Ca _X Si _Y Al _Z ON: Eu ²⁺ ), AE ₂ SiO ₄ : Eu phosphors (AE is an alkaline earth element such as Sr, Ba, Ca, etc.) and silicate phosphors such as Sr ₃ Si ₃ O ₅ : Eu ²⁺ phosphors, etc. Is selected accordingly. For example, a green phosphor having an emission intensity peak (hereinafter referred to as “emission peak”) excited in the blue light and having a wavelength in the range of 500 nm to less than 540 nm, and having an emission peak in the wavelength of 540 nm to less than 590 nm. A yellow phosphor and a red phosphor having an emission peak in a wavelength range of 590 nm to less than 650 nm can be used. In addition, the types and blending ratios of the phosphors of the respective light emitting units that emit the respective monochromatic lights are desired so that the average color rendering index Ra of light emission from the light emitting device is high and high luminous efficiency is obtained. The color temperature is adjusted so as to obtain white color.

  The device substrate 4 is made of a flat plate made of a metal or an insulating material such as a synthetic resin, and has a predetermined shape such as a rectangular shape in order to obtain a light emitting area required for the light emitting device 1. When the device substrate 4 is made of a synthetic resin, it can be formed of, for example, an epoxy resin containing glass powder. When the device substrate 4 is made of metal, the heat radiation from the back surface of the device substrate 4 is improved, the temperature of each part of the device substrate 4 can be made uniform, and the semiconductor light emitting element 2 that emits light in the same wavelength range. The variation in the emission color can be suppressed. In addition, as a metal material which has such an effect, the material excellent in the heat conductivity of 10 W / m * K or more, specifically, aluminum or its alloy can be illustrated.

  The reflective layer 31 is sized so that a predetermined number of semiconductor light emitting elements 2 can be disposed, and is, for example, attached to the entire surface of the device substrate 4. The reflective layer 31 can be made of a white insulating material having a reflectance of 85% or more in the wavelength region of 400 to 740 nm. As such a white insulating material, a prepreg made of an adhesive sheet can be used. Such a prepreg can be formed, for example, by impregnating a sheet base material with a thermosetting resin mixed with a white powder such as aluminum oxide. The reflective layer 31 is bonded to the entire surface of the device substrate 4 by its own adhesiveness.

  The circuit pattern 3 is bonded to a surface of the reflective layer 31 opposite to the surface to which the device substrate 4 is bonded as an energizing element for each semiconductor light emitting element 2. The circuit pattern 3 is formed in two rows dotted at predetermined intervals in the longitudinal direction of the device substrate 4 and the reflective layer 31 in order to connect the semiconductor light emitting elements 2 in series, for example. The end-side circuit pattern 3a located on one end side of the row of one circuit pattern 3 is integrally formed with a power feeding pattern portion 3c. Similarly, the end located on one end side of the row of the other circuit pattern 3 The side circuit pattern 3a is integrally formed with a power feeding pattern portion 3d. The power feeding pattern portions 3 c and 3 d are provided side by side at one end in the longitudinal direction of the reflective layer 31, and are separated from each other and insulated by the reflective layer 31. An electric wire (not shown) reaching the power source is individually connected to each of the power supply pattern portions 3c and 3d by soldering or the like.

  Each semiconductor light emitting element 2 is disposed between circuit patterns 3 adjacent to each other in the longitudinal direction of the device substrate 4, and is bonded to the same surface of the white reflective layer 31 by an adhesive layer 32. Specifically, the other surface parallel to one surface of the element substrate 2 b on which the semiconductor light emitting layer 2 a is laminated is bonded to the reflective layer 31 by the adhesive layer 32. By this adhesion, the circuit pattern 3 and the semiconductor light emitting element 2 are arranged in a straight line on the same surface of the reflective layer 31. Therefore, the side surface of the semiconductor light emitting element 2 positioned in this arrangement direction and the circuit pattern 3 are close to each other. It is provided so as to face each other. The thickness of the adhesive layer 32 can be, for example, 5 μm or less. For the adhesive layer 32, for example, a translucent adhesive having a thickness of 5 μm or less and a light transmittance of 70% or more, for example, a silicone resin-based adhesive can be suitably used.

  As shown in FIGS. 1 and 2, the electrode of each semiconductor light emitting element 2 and the circuit pattern 3 disposed in proximity to both sides of the semiconductor light emitting element 2 are connected by a bonding wire 6. Further, the end-side circuit patterns 3b positioned on the other end side of the two rows of circuit patterns 3 rows are also connected by bonding wires 6. Therefore, in this embodiment, each semiconductor light emitting element 2 is connected in series. The surface light source of the light emitting device 1 is formed by the device substrate 4, the reflective layer 31, the circuit pattern 3, each semiconductor light emitting element 2, the adhesive layer 32, and the bonding wire 6.

  The reflector 34 is not individually provided for each one or several semiconductor light emitting elements 2, but is a single one that surrounds all the semiconductor light emitting elements 2 on the reflective layer 31, and has a rectangular frame, for example. Thus, the semiconductor light emitting element 2 is disposed in the recess 7 formed by the frame. The reflector 34 is bonded to the reflective layer 31, and a plurality of semiconductor light emitting elements 2 and circuit patterns 3 are housed therein, and the pair of power feeding pattern portions 3 c and 3 d are positioned outside the reflector 34. ing. The reflector 34 can be formed of, for example, a synthetic resin, and its inner peripheral surface is a reflective surface. The reflecting surface of the reflector 34 can be formed by vapor deposition or plating of a metal material having a high reflectance such as Al or Ni, or can be formed by applying a white paint having a high visible light reflectance. Alternatively, white powder can be mixed into the molding material of the reflector 34 to make the reflector 34 itself white with high visible light reflectivity. As said white powder, white fillers, such as aluminum oxide, titanium oxide, magnesium oxide, barium sulfate, can be used. In addition, it is desirable to form the reflecting surface of the reflector 34 so as to gradually open in the irradiation direction of the light emitting device 1.

  The phosphor-containing resin layer 9 is used to obtain a desired monochromatic light by using a liquid thermosetting resin obtained by mixing each kind of phosphor in a predetermined blending amount for each light emitting unit group using an injection device such as a dispenser. For each line, the surface of the reflective layer 31 and the semiconductor light emitting elements 2 and the bonding wires 6 arranged on the straight line are filled evenly, and the lines are formed along the semiconductor light emitting elements 2 arranged on the straight line. It is formed by coating and filling in the shape and curing the thermosetting resin by heating. Similarly, a phosphor layer including a phosphor that emits light of a desired color is formed for each predetermined line of each semiconductor light emitting element 2 arranged on a straight line. In this way, when the phosphor layers (transparent resin layer for blue light) of each light emitting unit group are formed in a line shape, the manufacturing is easy and the manufacturing cost is low. In addition, when apply | coating the thermosetting resin containing fluorescent substance using injection devices, such as a dispenser, it is preferable to apply | coat with high viscosity of about 14 Pa * S, for example. In addition, a wall portion for coating each line can be provided on the substrate 4 in advance before the application of the thermosetting resin. As described above, the phosphors in the same light emitting unit group are formed on the LED blue chip 2 using the two-component silicone resin blended at the same blending ratio, so that monochromatic light is emitted from the phosphor. Can be suppressed, and light emission with less variation in characteristics of light emitted from the phosphor, for example, emission intensity and chromaticity (for example, color temperature) can be obtained.

  Next, an arrangement pattern in which each light emitting unit group is arranged on the substrate will be described. FIG. 3 is a diagram schematically illustrating an example of a light emitting device in which three light emitting unit groups are arranged in parallel in a line along the semiconductor light emitting elements 2 arranged on a straight line. As shown in FIG. 3, the three groups of light emitting units arranged in parallel with each other in a line form are a group of light emitting units that radiate blue light from the blue LED chip 2 through the transparent resin layer, and the blue light. A light emitting unit group that emits red light when excited and a light emitting unit group that emits green light when excited by the blue light are sequentially configured. The circuit pattern 3 can also be set so that each light emitting unit group can individually emit monochromatic light. In this way, by forming three types of light emitting unit groups in parallel in a line along each semiconductor light emitting element 2, there is more variation in phosphors for each light emitting unit group, particularly variations due to coating amount. It is suppressed. In addition, since it is applied in a line shape, it is easy to manufacture.

  FIG. 4 is a diagram schematically illustrating an example of a light emitting device in which four light emitting unit groups are arranged in parallel in a line shape. The four light emitting unit groups include a light emitting unit group that emits (transmits) blue light, a light emitting unit group that emits green light, a light emitting unit group that emits yellow light, and a light emitting unit group that emits red light. , And so on. The circuit pattern 3 can also be set so that each of these four light emitting unit groups can individually emit monochromatic light. As described above, by arranging the four light emitting unit groups, it is easy to adjust the chromaticity variable color.

  FIG. 5 is a diagram schematically illustrating an example of a light emitting device in which four light emitting unit groups are arranged in parallel in two stages of lines. Here, the arrangement parallel to the two-stage lines means that the LED light-emitting elements 2 on the substrate 4 are substantially orthogonal to the arrangement direction of the semiconductor light-emitting elements 2 arranged on a straight line connected by bonding wires. Divided into two stages, upper and lower, from the center, so that each of the four light emitting groups in the upper and lower ranges is in a line, and every two upper and lower light emitting groups are parallel to each other To place. In this way, by arranging the four light emitting unit groups in parallel in two stages of lines, it is easier to mix monochromatic light.

  FIG. 6 is a diagram schematically illustrating an example of a light emitting device in which each of the four light emitting unit groups is arranged in a matrix. Arranging in a matrix form means that the light emitting unit groups are arranged in a lattice form as shown in FIG. The circuit pattern 3 can also be set so that each of the four groups of light emitting units can individually emit monochromatic light. As described above, by arranging the four light emitting unit groups in a matrix, it is easier to mix monochromatic light from each light emitting unit group, and the light diffusing member 33 is omitted or at least the light diffusing member 33 The thickness can be reduced, and a decrease in luminance due to the use of the light diffusing member 33 can be suppressed.

  Further, since the light emitting device 1 according to this embodiment is a COB module, the interval between the LED chips 2 on the substrate 4 can be narrowed (narrow pitch), and thus a lighter device with higher brightness can be obtained. it can. Moreover, since the space | interval of the LED chip 2 can be narrowed, the light by which the monochromatic light obtained from each light emission part group was mixed more can be obtained.

  In the LED lamp 1 of this embodiment, the applied electric energy is converted into blue light having a dominant wavelength of 420 to 480 nm (for example, 460 nm) by the LED chip 2 and emitted. The emitted blue light is converted into light having a longer wavelength by each phosphor in each light emitting unit group. Based on the emission color (single color) from each light emitting unit group, it is mixed with the blue light emitted from the LED chip and becomes monochromatic light. White light based on the mixed color of monochromatic light from each of these phosphors is emitted from the LED lamp 1. The light emitting device configured as described above can obtain light emission with high luminous efficiency and desired chromaticity while maintaining high color rendering properties. Further, by adjusting the phosphor type, blending amount, and / or phosphor resin thickness (optical path length) in each light emitting unit group, white light with a suppressed deviation from black body radiation at a desired color temperature is obtained. be able to.

Next, another example of the light emitting device according to one embodiment of the present invention will be described. In this embodiment, an ultraviolet light emitting chip is used instead of the blue light emitting chip. As the ultraviolet light emitting type LED chip, any existing ones including GaN-based and In _x Ga _1-x N-based can be used.

As the blue phosphor that is excited by ultraviolet light and emits blue light, a BAM phosphor such as BaMgAl ₁₀ O ₁₇ : Eu ²⁺ is used, but is not particularly limited. For example, (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ is used as the green phosphor that emits green light when excited by ultraviolet light, but is not particularly limited. Examples of red phosphors that emit red light when excited by ultraviolet light include oxysulfide phosphors such as La ₂ O ₃ S: Eu ³⁺ phosphors, nitride phosphors (for example, CaAlSiN ₃ : Eu), and the like. Alternatively, germanate-based phosphors such as manganese-activated magnesium fluorogermanate (2.5MgO · MgF ₂ : Mn ⁴⁺ ) are used, but are not particularly limited. As a phosphor that emits yellow light when excited by ultraviolet light, (Y, Gd) ₃ Al ₅ O ₁₂ : Ce or the like is used, but it is not particularly limited. For example, a blue phosphor having an emission intensity peak in a wavelength range of 420 nm to 480 nm when excited by the ultraviolet light, a green phosphor having an emission peak in a wavelength range of 500 nm to less than 540 nm, and a wavelength range of 540 nm to less than 590 nm. A yellow phosphor having an emission peak in the red region, a red phosphor having an emission peak in the wavelength range of 590 nm to less than 650 nm, and the like can be used. In addition, the types and blending ratios of the phosphors of the respective light emitting units that emit the respective monochromatic lights are desired so that the average color rendering index Ra of light emission from the light emitting device is high and high luminous efficiency is obtained. The color temperature is adjusted so as to obtain white color.

  Even in the LED lamp 1 of this embodiment, it is possible to obtain light emission with high luminous efficiency and desired chromaticity while maintaining high color rendering properties. Further, by adjusting the phosphor type, blending amount, and / or phosphor resin thickness (optical path length) in each light emitting unit group, white light with a suppressed deviation from black body radiation at a desired color temperature is obtained. be able to.

  Next, light emission from the light emitting devices according to these embodiments will be further described with reference to the CIE chromaticity diagram. FIG. 7 is a diagram showing the chromaticity (variable color gamut) of light emission of the light emitting device according to these embodiments. Here, a case where a blue light emitting chip is used will be described. The light emitting device 1 includes a light emitting unit group 2B that emits green light when excited by blue light, a light emitting unit group 2Y that emits yellow light, a light emitting unit group 2R that emits red light, and a light emitting unit that emits blue light. And a group 2B. Since the light-emitting device according to this embodiment can obtain blue light, green light, yellow light, and red light, the chromaticity in the range shown in FIG. 7 can be obtained, and can be varied within this range. is there. This will be described in detail below.

  In the chromaticity diagram of FIG. 7, the chromaticity of blue light emitted from the blue LED chip is a point A, and the chromaticity of light emitted from a green phosphor having a dominant wavelength of 525 nm is a point B, and the dominant wavelength is 565 nm. The chromaticity of light emitted from the yellow phosphor having the same is represented by point C, and the chromaticity of light emitted from the red phosphor having a dominant wavelength of 630 nm is represented by point D. The locus of black body radiation (black body locus) is represented by a curve a. Further, a desired color temperature (for example, 5000 K) is represented by a point E on the black body locus a, and a deviation in the color temperature is represented by a straight line including the point E. Similarly, another desired color temperature on the black body locus a and a deviation in the color temperature are represented by points on the black body locus a and straight lines including the points.

  Light emission from the green light emitting unit group 2G is chromaticity of light obtained by adding green light emission from the green phosphor and blue light from the blue LED chip. On the chromaticity diagram shown in FIG. And an arbitrary point (not shown) on a straight line connecting point B and point B. This point can be moved by adjusting the blending amount of the green phosphor. For example, it can be moved to the point B side by increasing the blending amount of the green phosphor. Similarly, light emitted from the red light emitting unit group 2R can be moved to an arbitrary point (not shown) on the straight line connecting the points A and D by adjusting the blending amount of the red phosphor. Here, by adjusting the blending amount of the green phosphor and the blending amount of the red phosphor, it is possible to obtain the chromaticity of an arbitrary point in the triangle formed by connecting the points A, B and C. become. Further, the light emitted from the yellow light emitting unit group 2Y is similarly moved to any point (not shown) on the straight line connecting the points A and C by adjusting the blending amount of the yellow phosphor. Therefore, by adjusting the blending amount of the green phosphor, the red phosphor, and the yellow phosphor, the chromaticity of an arbitrary point within the square connecting the points A, B, C, and D can be obtained. Can do. That is, white light with suppressed color deviation at a desired color temperature can be obtained. The light emission from the light emitting unit group including each phosphor is adjusted by adjusting not only the blending amount of each phosphor but also the thickness (optical path length) of the phosphor resin layer containing each color phosphor. it can.

  In addition, each light emitting unit group is set so that current can be supplied from a power source through an electric wire (not shown) via the power supply pattern units 3c and 3d so that each light emitting unit individually emits monochromatic light, and is supplied from the power source. By adjusting the current to be adjusted, the electric energy applied to the blue LED chip of each light emitting unit group is adjusted to adjust the light emission of the LED, thereby obtaining light emission of a desired chromaticity. In this case, it is variable by adjusting the current supplied from the power source without changing the blending amount of the phosphor of each light emitting unit group including each phosphor and the setting of the thickness (optical path length) of the phosphor layer. Since it can be colored, a variable color light emitting device can be provided. In addition, a lineup of variable colors is possible within a range according to the application, and it can also be used as a display device.

  Next, examples of the present invention will be described.

(Example 1)
A COB package in which the number of chips is mounted 11 by 12 in length and 12 by 12 in about 5 cm square was prepared. The COB package has a system in which the vertical line chips can be individually lit. As the chip, a blue chip emitting light having a wavelength of 460 nm was used.
For green light, a green phosphor having a peak wavelength at a wavelength of 525 nm was blended in a two-pack type transparent silicone resin at about 30% by weight and completely dispersed. A yellow phosphor having a peak wavelength at a wavelength of 565 nm for yellow light and a red phosphor having a peak wavelength at 630 nm for red light were mixed in a two-pack type transparent silicone resin at about 30% by weight. Dispersed. For blue light, a phosphor was not contained and only a two-pack type transparent silicone resin was used.

  Next, in order to obtain a desired color for each line, the various phosphor-containing silicone resins thus obtained were applied for each line in the recess 8 having an opening diameter of 3 mm, and then the silicone resin was cured. A phosphor-containing resin layer was formed to produce an LED lamp 1 having the configuration shown in FIG. These resins were applied at a high viscosity of 14 Pa · s. As shown in FIG. 4, each color was separately applied in the order of blue, yellow, green, and red from the left. The optical path length of the phosphor-containing resin layer 9 was 1.0 mm. The optical path length refers to the thickness of the phosphor-containing resin layer on the light extraction side from the upper surface of the LED chip.

  The LED lamp thus obtained was caused to emit light, and the color temperature of the light emission, the deviation of the color temperature, the average color rendering index Ra, and the light emission efficiency were measured, and the chromaticity was within the range of the variable color gamut shown in FIG. It was confirmed to exist. Therefore, it was confirmed that desired chromaticity can be obtained within the variable color gamut of FIG. 7 by changing the blending ratio (wt%) of the green phosphor, the yellow phosphor and / or the red phosphor. Further, it was confirmed that white light having no color deviation was obtained at a predetermined color temperature.

It is a top view which shows an example of the light-emitting device concerning one Embodiment of this invention. It is the FF sectional view taken on the line of FIG. It is a figure which shows typically an example of the light-emitting device which has arrange | positioned the light emission part group of 3 groups in parallel with the line form, respectively. It is a figure which shows typically an example of the light-emitting device which has arrange | positioned the light emission part group of 4 groups in parallel with the line shape, respectively. It is a figure which shows typically an example of the light-emitting device which has arrange | positioned four light emission part groups in parallel at 2 steps | paragraphs of lines, respectively. It is a figure which shows typically an example of the light-emitting device which has arrange | positioned each light emission part group of 4 groups in matrix form. It is a figure which shows typically the chromaticity (variable color gamut) of light emission of the light-emitting device concerning one Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... LED lamp, 2 ... LED chip, 3 ... Circuit pattern, 4 ... Board | substrate, 6 ... Bonding wire, 7 ... Recessed part, 8 ... Frame, 9 ... Phosphor containing resin layer, 31 ... Reflective layer, 32 ... Adhesive layer, 33: Light diffusing member, 34: Reflector.

Claims (7)

A substrate;
There are three or more light emitting unit groups arranged in a predetermined arrangement pattern on the substrate, each of which emits monochromatic light, and one of the light emitting unit groups emits a plurality of blue lights arranged on the substrate. A light emitting unit other than the light emitting unit group having a light emitting element that emits light and a transparent resin layer coated on the light emitting element has a plurality of blue lights disposed on the substrate. A phosphor layer comprising a light-emitting element that emits light, and a phosphor that emits visible light by the blue light coated on the light-emitting element, and that has the same type and mixing ratio for each light-emitting unit group A light emitting group having the following:
A light-emitting device comprising:   A first light emitting unit group including a phosphor layer including a green phosphor that emits green light when the light emitting unit group other than the light emitting unit group having the transparent resin layer is excited by blue light emitted from the light emitting element. And a second light emitting unit group having a phosphor layer including a yellow phosphor that emits yellow light when excited by blue light emitted from the light emitting element, and excited by blue light emitted from the light emitting element. The light emitting device according to claim 1, further comprising: a third light emitting unit group having a phosphor layer including a red phosphor that emits red light. A substrate;
Three or more groups of light emitting units that emit monochromatic light, each arranged in a predetermined arrangement pattern on the substrate, and the light emitting units emit light that emits a plurality of ultraviolet lights arranged on the substrate. A light emitting unit group having a phosphor layer including a device and a phosphor that emits visible light by the ultraviolet light, and includes a phosphor having the same kind and mixing ratio for each light emitting unit group;
A light-emitting device comprising:   The light emitting unit group includes a fourth light emitting unit group having a phosphor layer including a blue phosphor that emits blue light when excited by ultraviolet light emitted from the light emitting element, and ultraviolet light emitted from the light emitting element. A fifth light emitting unit group having a phosphor layer including a green phosphor that emits green light when excited by light, and a yellow phosphor that emits yellow light when excited by ultraviolet light emitted from the light emitting element. A sixth light emitting unit group having a phosphor layer containing, a seventh light emitting unit group having a phosphor layer containing a red phosphor that emits red light when excited by ultraviolet light emitted from the light emitting element; The light emitting device according to claim 3, comprising:   The light-emitting device according to claim 1, wherein the predetermined arrangement pattern is a line shape or a matrix shape.   6. The light emitting device according to claim 1, wherein white light is emitted by light from the light emitting unit group.   6. The light-emitting device according to claim 1, wherein light having a variable color gamut is emitted by light from the light-emitting unit group.

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