JP2011066314A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device for obtaining a light emission color within required chromaticity while keeping a concentration of a fluorescent material lower. <P>SOLUTION: A light emitting diode (LED) 100 includes lead frames 3 and 4. A recess 3a is formed at one terminal end of the lead frame 3. A blue LED chip 1 is bonded and fixed to the bottom of the recess 3a by die bonding. The LED chip 1 emits blue light with an emission peak in a wavelength range of 430-480 nm, for example. A coating section 2 is formed in the recess 3a. The coating section 2 includes a red fluorescent material 10. Terminal ends of the lead frame 3 and 4 where the coating sections 2 are formed are stored in a lens 6 having a convexed tip. The lens 6 is formed of a translucent resin such as epoxy resin and the lens 6 is colored with a red coloring agent 61. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device that emits light of a specific color, and more particularly to a light emitting device that can improve visibility.

  The visual cells of the human eye are classified into rods and cones based on their morphology, and the cones are classified into three types: red cones, green cones, and blue cones due to their different spectral absorption characteristics. Spectral absorption characteristics of each cone depend on the properties of the visual substance.The red cones express the red visual substance, the green cones express the green visual substance, and the blue cones express the blue visual substance. Depending on what wavelength component the light has, each cone is stimulated through each visual material and perceived as a color.

  A state in which one of the functions of a red vision substance, a green vision substance, or a blue vision substance is impaired is called color blindness. The majority of color vision disorders are the first color vision disorder (about 25% of all color vision disorders) with mutations in the red vision substance gene, or the second color vision disorder with mutations in the green vision substance gene (all color vision disorders) About 75%), and even if the function of either the red or green visual substance is lost, it becomes a similar symptom that it is difficult to feel the color difference in the green to red wavelength range. It is collectively called. On the other hand, the third color blindness with a mutation in the blue vision substance gene is only about 0.02% of the total color blindness.

  Red-green color vision impairment (first color vision impairment, second color vision impairment), which accounts for the majority of color vision impairments, makes it difficult to distinguish colors with similar brightness in the green to red wavelength range (color identification of objects) It has become. In particular, in the wavelength range of light, the colors on the left and right (short wavelength side and long wavelength side) appear to be almost the same with the yellow to green wavelength range as the center. It is difficult to distinguish and recognize the difference.

  In addition, an elderly person may develop cataract with aging, the lens becomes cloudy, and it may be difficult to recognize the yellow color.

  On the other hand, as a light emitting device that emits red light, for example, a red light emitting diode (LED) is used in various fields such as information display devices, home appliances, AV equipment, mobile phones, in-vehicle devices, and traffic lights. In addition, yellow light emitting diodes (LEDs) are used for barrier-free purposes by irradiating pedestrian boundary blocks that are difficult to see at night.

  In addition to red, light-emitting diodes that emit light of various colors according to applications have been put into practical use. These light-emitting diodes include a phosphor that emits light when excited by light of a predetermined wavelength, and includes a surrounding portion that surrounds the LED chip (see, for example, Patent Document 1).

JP 2004-161863 A

  In the light emitting diode disclosed in Patent Document 1, it is necessary to adjust the concentration of the phosphor so that the emission color of the light emitting diode falls within a required chromaticity range depending on the application. However, if the concentration of the phosphor is too high, the viscosity increases, and as a result, it takes a long time to coat the phosphor and the productivity of the light emitting diode is reduced.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light emitting device capable of realizing a light emission color within a required chromaticity range while keeping a phosphor concentration low.

  A light-emitting device according to a first aspect of the present invention includes a light-emitting element and a phosphor that emits light of a predetermined wavelength when excited by light from the light-emitting element, and a cover that covers the light-emitting element and the phosphor emits And a lens that is colored in the same color as light and transmits light emitted from the light emitting element and the phosphor.

  A light emitting device according to a second invention is the light emitting device according to the first invention, wherein the light emitting element is a blue light emitting element having a light emission peak in a wavelength range of 430 to 480 nm, and the phosphor has a light emission peak having a wavelength of 620 to 660 nm. It is a red phosphor that emits light, and the lens is colored with a red colorant.

  A light emitting device according to a third invention is the light emitting device according to the first invention, wherein the light emitting element is a blue light emitting element having a light emission peak in a wavelength range of 430 to 480 nm, and the phosphor has a light emission peak having a wavelength of 570 to 590 nm. It is a yellow phosphor that emits light, and the lens is colored with a yellow colorant.

  In the first invention, the light-emitting element and the phosphor that emits light of a predetermined wavelength when excited by light from the light-emitting element, and the covering portion that covers the light-emitting element, and the same color as the light emitted by the phosphor And a lens that transmits light emitted from the light emitting element and the phosphor. Here, it is assumed that the same color includes not only the same color but also a color having a similar hue. For example, when the lens is not colored, it is assumed that the concentration of the phosphor necessary for obtaining a light emission color in a desired chromaticity range is high (for example, 50%). Since the lens is colored with the same color as the light emitted from the phosphor, the concentration of the phosphor is lower (for example, 50%) than the concentration of the phosphor when the lens is not colored (for example, 50%). 25%), it is possible to obtain a light emission color comparable to that of a high phosphor concentration (for example, 50%), and a light emission color within a required chromaticity range while keeping the phosphor concentration low. Can be realized. Further, since the concentration of the phosphor can be kept low, the viscosity can be reduced, the phosphor can be applied in a short time, and the productivity of the light emitting diode is improved.

  In the second invention, the light emitting element is a blue light emitting element having an emission peak in a wavelength range of 430 to 480 nm. The phosphor is a red phosphor that emits light having an emission peak of a wavelength of 620 to 660 nm, and the lens is colored with a red colorant. The red phosphor contained in the coating part is excited by blue light and emits red light having an emission peak wavelength of 620 to 660 nm. The light emitted from the blue light emitting element and the red phosphor is transmitted to the outside through the lens colored with the red colorant. That is, the light emitting device attenuates the blue component light, and even when the red phosphor concentration is lowered, the red component intensity is reinforced by the red colorant so that the red component light is in the required chromaticity range. To be inside.

  The relative sensitivity of a healthy person's red cone has a peak in the vicinity of a wavelength of 560 nm and decreases in a wavelength range from about 560 nm to about 700 nm. On the other hand, the relative sensitivity of the blue cones of healthy and red-green color blind persons has a peak near 440 nm, decreases in the wavelength range from about 440 nm to about 540 nm, and decreases sharply at about 540 nm. Sensitivity is maintained up to around 640 nm. By setting the dominant wavelength (emission peak) of red emitted from the light emitting device to around 620 to 660 nm, the wavelength width (half width) is made wider than the dominant wavelength (eg, 620 to 630 nm) of the conventional red light emitting diode. Even when the relative sensitivity of the red cone of a color blind person (red-green color blind person) is lower than that of a healthy person, the degree of relative response to the red cone is increased. In addition, by setting the blue dominant wavelength (emission peak) emitted by the light emitting device to be around 430 to 480 nm, relative to the blue cone of the color blind person, which is difficult with a single red color like a conventional red light emitting diode. Even in a wavelength range where the sensitivity is reduced (for example, 440 nm to 480 nm), the degree of relative response to the blue cone is increased.

  Since the emission color (combination of red and blue) in the required chromaticity range can be obtained with the red colorant while keeping the concentration of the red phosphor low, the wavelength at which the relative sensitivity of the red cone decreases. In the case of red only by increasing the relative response of the blue cone in the wavelength range where the relative sensitivity of the blue cone is reduced as well as increasing the relative response to the red cone in the region Compared with the above, the color reproducibility is improved, the red discrimination ability of the color blind person can be improved, and the red color can be recognized without any discomfort for the healthy person.

  In the third invention, the light emitting element is a blue light emitting element having an emission peak in a wavelength range of 430 to 480 nm. The phosphor is a yellow phosphor that emits light having an emission peak of a wavelength of 570 to 590 nm, and the lens is colored with a yellow colorant. The yellow phosphor contained in the coating is excited by blue light and emits yellow to yellow-green light having an emission peak of 570 to 590 nm. Light emitted from the blue light emitting element and the yellow phosphor is transmitted to the outside through the lens colored with the yellow colorant. That is, the light-emitting device reinforces the intensity of the yellow component with the yellow colorant so that the light of the yellow component falls within the required chromaticity range even when the yellow phosphor concentration is lowered.

  This makes it possible to obtain a light emission color (combination of yellow and blue) within the required chromaticity range with a yellow colorant while keeping the concentration of the yellow phosphor low. In addition to providing an excellent light emitting diode, the concentration of the phosphor can be kept low, the viscosity can be reduced, and the phosphor can be applied in a short time. Productivity is improved.

  According to the first invention, it is possible to realize a light emission color within a required chromaticity range while keeping the concentration of the phosphor low. Further, since the concentration of the phosphor can be kept low, the viscosity can be reduced, the phosphor can be applied in a short time, and the productivity of the light emitting diode is improved.

  According to the second invention, the color reproducibility is improved as compared with the case of only red, the red discrimination ability for the color blind person can be improved, and the red color can be recognized without any discomfort for the healthy person. Can do.

  According to the third invention, a light-emitting diode with excellent visibility can be provided, and the concentration of the phosphor can be kept low, so that the viscosity can be reduced and the phosphor can be applied for a short time. The productivity of the light emitting diode is improved.

It is front sectional drawing which shows the structural example of the light emitting diode which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the filter characteristic of a red colorant. It is explanatory drawing which shows an example of the emission spectrum of a light emitting diode. It is explanatory drawing which shows an example of the chromaticity change with respect to the ratio of a red coloring agent. It is a CIE chromaticity diagram which shows the luminescent color of a light emitting diode. It is explanatory drawing which shows the relative sensitivity of each cone of a healthy person. It is explanatory drawing which shows an example of the relative sensitivity of each cone of a red-green color vision handicapped person (1st color vision handicapped person). It is explanatory drawing which shows an example of the emission spectrum of the conventional red light emitting diode.

Embodiment 1
Hereinafter, the present invention will be described with reference to the drawings illustrating embodiments thereof. FIG. 1 is a front sectional view showing a configuration example of a light emitting diode 100 according to an embodiment of the present invention. As shown in FIG. 1, a light emitting diode 100 as a light emitting device according to the present invention includes lead frames 3 and 4, and a recess 3 a is provided at one end of the lead frame 3. A blue LED chip 1 as a blue light emitting element is bonded and fixed to the bottom of the recess 3a by die bonding. The LED chip 1 can emit blue light having an emission peak in a wavelength range of 430 to 480 nm, for example.

  One electrode of the LED chip 1 is wire-bonded to the lead frame 3 by a wire 5, and the other electrode is wire-bonded to the lead frame 4 by a wire 5. A covering portion 2 that covers the LED chip 1 is formed in the concave portion 3a by being filled with a translucent resin. The end portions of the lead frames 3 and 4 on which the covering portion 2 is formed are housed in a lens 6 having a tip portion that is convex. The lens 6 is formed of a translucent resin such as an epoxy resin, and the entire lens 6 is colored with a red colorant 61. Note that a part of the lens 6 may be colored with the red colorant 61. Further, the color of the colorant may be the same color as the color of light emitted from the phosphor. Here, the same color includes not only the same color but also a color with similar hues.

The covering portion 2 contains the red phosphor 10 that is excited by blue light emitted from the LED chip 1 and emits red light having an emission peak wavelength of 620 to 660 nm. The concentration of the red phosphor 10 is 25%. The red phosphor 10 is formed, for example, by firing a mixture made of calcium sulfide (CaS) and europium sulfide (EuS). Specifically, a mixing process of mixing CaS and EuS, a holding process for holding the product after the mixing process at a temperature of 900 to 1100 ° C. for a predetermined time, a cooling process for cooling the product after the holding process, and after the cooling process The desired red phosphor 10 can be obtained by a holding process in which the temperature of the product is raised again and held at a temperature of 600 to 900 ° C. for a predetermined time. In this case, the molar ratio of europium sulfide (EuS) can be in the range of about 0.01 to 10, for example, where the total of calcium sulfide (CaS) and europium sulfide (EuS) is 100. Alternatively, an oxynitride phosphor can be used as the red phosphor 10. For example, Eu ²⁺ is activated to an inorganic compound having the same crystal structure as α-Si ₃ N ₄ and represented by the general formula α. Here, the general formula α is α: M (Si, Al) ₁₂ (O, N) ₁₆ , and M is Li, Mg, Ca, Sr, Y, or a lanthanoid element.

  As the red colorant 61, a known dye can be used. For example, C.I. I. Acid Red 118, or C.I. I. Acid Red 35 + C. I. Acid dyes such as Acid Yellow 23 to which water and alcohols are added can be used. Here, C.I. I. Is a color index.

  Examples of the red colorant 61 include ranacin red S-2GL (manufactured by Santos), irganol red BL (manufactured by Ciba Geigy), kayanol milling red RS, kayak lance scarlet GL (manufactured by Nippon Kayaku), and suminol. Level binol 3GP (manufactured by Sumitomo Chemical) or the like can also be used.

  The ratio of the red colorant 61 is 1.0% of the weight of the epoxy resin of the lens 6. In addition, the ratio of the red colorant 61 can be contained about 0.2% to 1.2% of the weight of the epoxy resin of the lens 6. Further, the ratio of the red colorant 61 is not limited to about 0.2% to 1.2%, and can be adjusted according to a required chromaticity range and the concentration of the red phosphor 10.

  With the above-described configuration, in the light emitting diode 100, the blue light from the LED chip 1 and the red light from the red phosphor 10 pass through the lens 6 and are emitted to the outside.

  FIG. 2 is an explanatory diagram showing an example of the filter characteristics of the red colorant 61. In FIG. 2, the horizontal axis represents the wavelength, and the vertical axis represents the transmittance. The transmittance of the red colorant 61 rises from around 550 nm. That is, when the wavelength is shorter than around 550 nm, light transmission is blocked. When the wavelength is longer than about 550 nm, the light transmittance is close to 100%, and the amount of light is not attenuated.

  FIG. 3 is an explanatory diagram showing an example of an emission spectrum of the light emitting diode 100. In FIG. 3, the horizontal axis represents wavelength, and the vertical axis represents relative intensity. In FIG. 3, the solid line indicates the case where the lens 6 is colored with the red colorant 61, and the broken line indicates the case where the lens 6 is not colored. The light emitting diode 100 emits blue light having a light emission peak in a wavelength range of 430 to 480 nm and red light having a light emission peak in a wavelength range of 620 to 660 nm. The spectrum half width of red light is about 100 nm. Here, the spectrum half width is a width of two wavelengths at which the relative emission intensity becomes half (50%) with respect to the peak value. In the example of FIG. 3, the wavelength at which the relative emission intensity of the emission spectrum is halved is approximately 600 nm and approximately 700 nm, and the half-value width is approximately 100 nm (700-600).

  When the lens 6 is colored in red (solid line graph), the emission peak of blue light is reduced by about one-fourth compared to when the lens 6 is not colored (broken line graph). This is because blue light (wavelength: 430 to 480 nm) is blocked as shown in the example of FIG. As a result, when the lens 6 is colored in red, the emission color of the light emitting diode 100 as a whole increases while the blue component decreases while the red component increases, compared with the case where the lens 6 is not colored. It can be seen that the chromaticity range can be adjusted according to the ratio of 61.

  In the example with the colorant in FIG. 3, the relative light emission intensity of the red light peak is 1 while the relative light emission intensity of the blue light peak is about 0.05. The ratio of the relative light emission intensity of light and blue light is not limited to the example of FIG.

  FIG. 4 is an explanatory diagram showing an example of chromaticity change with respect to the ratio of the red colorant 61. In FIG. 4, the concentration of the red phosphor 10 is 10%, and the ratio of the red colorant 61 is 0%, 0.4%, 0.8%, 1.2% (C1 and C2 in FIG. 2, respectively). , C3, C4) (corresponding to the points indicated by C3) and C4). When the red colorant 61 is not contained (C1), the chromaticity coordinate is (0.56, 0.31), and the x color coordinate is increased as the proportion of the red colorant 61 is increased. It has changed (becomes larger). If the amount of the red phosphor 10 is increased, the emission color of the entire light emitting diode 100 changes from blue to red. Conversely, if the amount of the red phosphor 10 is decreased, the emission color of the entire light emitting diode 100 changes from red to blue. Thus, it can be seen that if the ratio of the red colorant 61 is increased, the same degree of chromaticity can be maintained even if the concentration of the red phosphor 10 is lowered.

  As an example, the emission color (chromaticity) obtained when the concentration of the red phosphor 10 is 50% and the red colorant 61 is not present is 25% for the concentration of the red phosphor 10 and the ratio of the red colorant 61 is 1. The same color (chromaticity) could be obtained at about 0%. That is, the light emitting diode 100 according to the present embodiment can obtain the same emission color as that when the phosphor concentration is high (for example, 50% or more), and the required chromaticity while keeping the phosphor concentration low. An emission color within the range can be realized.

  Conventionally, when a lens not containing the red colorant 61 is used, the concentration of the red phosphor 10 needs to be 50% or more. In this case, since the concentration of the phosphor is high and the viscosity becomes large, for example, it is necessary to slowly apply pressure over time to discharge the phosphor-containing resin from a dispenser (liquid metering discharge device) nozzle or needle. It was. In the light emitting diode 100 of the present embodiment, the concentration of the red phosphor 10 can be lowered to about 25%, so that the viscosity can be reduced, the phosphor can be applied in a short time, and the light emission can be achieved. Diode productivity is improved.

  FIG. 5 is a CIE chromaticity diagram showing the light emission color of the light emitting diode 100. As shown in FIG. 5, the light emission color of the light emitting diode 100 can be specified by color coordinates (x, y). In FIG. 5, a trapezoidal region (region with a pattern in the drawing) is the light emitting diode 100. A chromaticity range A. That is, the chromaticity range A includes the following four points (0.54, 0.234), (0.54, 0.302), (0.631, 0.35), (0.68, 0. 30). In order to obtain a desired color coordinate value within the chromaticity range A, for example, the ratio of the red colorant 61 of the lens 6 is reduced after the concentration of the red phosphor is lowered from about 50% to about 25%. Can be realized, for example, by setting it to about 0.2 or more. That is, in the light emitting diode 100 of the present embodiment, even when the red phosphor concentration is lowered, the intensity of the red component is reinforced by the red colorant 61 so that the red component light is within the required chromaticity range A. Can be. In addition, by setting the emission color of the light emitting diode 100 within the chromaticity range A, a healthy person is recognized as red without discomfort.

  FIG. 6 is an explanatory diagram showing the relative sensitivity of each cone of a healthy person. The horizontal axis indicates the wavelength of light, and the vertical axis indicates the relative sensitivity (spectral sensitivity) of each cone in terms of Log. The relative sensitivity (light-receiving spectrum) of the blue cone has a peak at around 450 nm, decreases in the wavelength region from around 450 nm to around 560 nm, decreases sharply at around 560 nm, but maintains the sensitivity up to around 640 nm. Yes. Further, the relative sensitivity of the red cone has a peak in the vicinity of the wavelength of 560 nm and decreases in the wavelength range from about 560 nm to about 700 nm. The relative sensitivity of the green cone has a peak near 540 nm and overlaps with the relative sensitivity of the red cone in a wide wavelength range, but is slightly shifted.

  In a healthy person, when light of a certain wavelength enters the eye, each of the three cones, the blue cone, the green cone, and the red cone, reacts according to the spectral sensitivity at that wavelength, and the three kinds of response degrees. The color of light can be discriminated by being different. That is, a healthy person can perceive as a different color due to the difference in the degree of reaction of each cone.

  FIG. 7 is an explanatory diagram showing an example of the relative sensitivity of each cone of a red-green color blind person (first color blind person), and FIG. 8 is an explanatory figure showing an example of the emission spectrum of a conventional red light emitting diode. It is. In FIG. 7, the horizontal axis indicates the wavelength of light, and the vertical axis indicates the relative sensitivity (spectral sensitivity) of each cone in terms of Log. In the example of FIG. 7, the relative sensitivity of the red cone is smaller than that of a healthy person, and the sensitivity is drastically decreased at a wavelength of 600 nm or more.

  On the other hand, as shown in FIG. 8, the conventional red light emitting diode has a light emission spectrum peak in the wavelength range of 620 nm to 630 nm, and the relative light emission intensity approaches zero at a wavelength of 600 nm or less. The red color emitted from the light emitting diode cannot be recognized by a color blind person, or the red color is felt dark. In the following description, it is assumed that the color blind person is a red-green color blind person. In addition, the example of FIG. 7 schematically shows the relative sensitivity of each cone of a color blind person, and is merely an example and is not limited thereto.

  As described above, the relative sensitivity of the red cone of a healthy person has a peak near the wavelength of 560 nm and decreases in the wavelength range from around 560 nm to around 700 nm. On the other hand, the relative sensitivity of the blue cones of healthy and color blind people has a peak near 450 nm, decreases in the wavelength region from about 450 nm to about 560 nm, and decreases sharply at about 560 nm, but near 640 nm. The sensitivity is kept up to. Even when the relative sensitivity of the red cone of the color blind person is lower than that of the normal person by setting the dominant wavelength (light emission peak) of red emitted from the light emitting diode 100 to around 620 to 660 nm, For example, in a wide wavelength range of 620 nm to 660 nm that cannot be achieved with a red light emitting diode, the degree of relative response to the red cone is increased. Further, by setting the blue dominant wavelength (emission peak) emitted from the light emitting diode 100 to around 440 to 480 nm, in a wavelength region (for example, 440 nm to 480 nm) in which the relative sensitivity of the blue cone of the color blind person is lowered. , Increase the relative response to blue cones.

  And while suppressing the density | concentration of the red fluorescent substance 10 low, since the luminescent color (combination of red and blue) of a required chromaticity range can be obtained with the red colorant 61, the relative sensitivity of a red cone falls. In addition to increasing the relative degree of response to the red cone in the wavelength range, the red cone is also increased in the wavelength range where the relative sensitivity of the blue cone is reduced. Compared with the above case, the color reproducibility is improved, the red discrimination ability of the color blind person can be improved, and the red color can be recognized without any sense of incongruity for the healthy person.

  Conventionally, red light-emitting diodes have been used in various fields such as information display devices, home appliances, AV equipment, mobile phones, in-vehicle devices, traffic lights, etc. There was a situation that was difficult to recognize. By using the light emitting diode 100 according to the above-described embodiment, a person with color blindness recognizes red light as pseudo red light according to the relative sensitivity of the red cone (depending on the degree of color blindness). Therefore, it is possible to solve the conventional problem that the lighting of red light cannot be determined and the problem that it is difficult to determine. At the same time, it is possible to provide a light emitting diode in red as long as a healthy person does not feel uncomfortable.

Embodiment 2
In the first embodiment described above, the red phosphor 10 is used. However, the phosphor is not limited to red, and other color phosphors such as a yellow phosphor can also be used. For example, when a yellow phosphor is used in accordance with the phosphor, a yellow colorant having the same color can be used.

In Embodiment 2, the covering portion 2 contains a yellow phosphor that is excited by blue light emitted from the LED chip 1 and emits yellow light (including yellow-green to orange) having an emission peak of a wavelength of 570 to 590 nm. ing. The concentration of the yellow phosphor is lower than the conventional concentration, for example, 25%, as in the first embodiment. The yellow phosphor may be, for example, an oxide phosphor, for example, a YAG phosphor having a (Y, Gd) ₃ Al ₅ O ₁₂ : Ce structure, or (Ba, Sr, Ca) ₂ SiO ₄ : Eu. Sr ₄ Al ₁₄ O: Eu or a sulfide (ZnS) doped with Eu may be used. The yellow phosphor is an oxynitride phosphor obtained by activating Eu ²⁺ on an inorganic compound represented by the general formula (α) having the same crystal structure as α-Si ₃ N ₄ , for example. Yes, (α) is M _X (Si, Al) ₁₂ (O, N) ₁₆ . However, M is Li, Mg, Ca, Sr, Y, or a lanthanoid element.

  A known dye can be used as the yellow colorant. For example, C.I. I. Acid dyes such as Acid Yellow 23 to which water and alcohols are added can be used. Here, C.I. I. Is a color index.

  As a yellow colorant, for example, Irganol Yellow 4GLS (manufactured by Ciba Geigy), Kayakaran Yellow GL143 (manufactured by Nippon Kayaku), Suminol Yellow MR (manufactured by Sumitomo Chemical), etc. can also be used.

  The ratio of the yellow colorant can be about 1.0% to 2.0% of the weight of the epoxy resin of the lens 6. The ratio of the yellow colorant is not limited to about 1.0% to 2.0%, and can be adjusted according to the required chromaticity range and the concentration of the red phosphor 10.

  In the second embodiment, as in the first embodiment, the LED chip 1 has an emission peak in the wavelength range of 430 to 480 nm. The phosphor is a yellow phosphor that emits light having an emission peak wavelength of 570 to 590 nm, and the lens 6 is colored with a yellow colorant. The yellow phosphor contained in the covering portion 2 is excited by blue light and emits yellow to yellow-green light having an emission peak of a wavelength of 570 to 590 nm. The light emitted from the LED chip 1 and the yellow phosphor passes through the lens 6 colored with a yellow colorant and is emitted to the outside. That is, the light emitting diode 100 can reinforce the intensity of the yellow component with the yellow colorant so that the light of the yellow component is within the required chromaticity range even when the yellow phosphor concentration is lowered. it can.

  This makes it possible to obtain a light emission color (combination of yellow and blue) within the required chromaticity range with a yellow colorant while keeping the concentration of the yellow phosphor low. In addition to providing an excellent light emitting diode, the concentration of the phosphor can be kept low, the viscosity can be reduced, and the phosphor can be applied in a short time. Productivity is improved.

  Further, depending on the color of the phosphor, the colorant can be changed to other colors. Examples of the green colorant include C.I. I. Acid Green 25, C.I. I. Acid Blue 9 + C. I. Acid dyes such as Acid Yellow 23 to which water and alcohols are added can be used. Examples of blue colorants include C.I. I. Acid Blue 113, C.I. I. Acid Blue 9 + C. I. What added water and alcohol to acid dyes, such as acid red 35, can be used.

  In the above-described embodiment, the lens 6 is configured to contain a colorant in a resin such as an epoxy resin. However, the present invention is not limited to this, and the lens 6 is formed of an epoxy resin or the like. The structure which apply | coats a coloring agent to the surface, or affixes the sheet | seat containing a coloring agent may be sufficient.

1 LED chip (light emitting device)
2 Cover 6 Lens 10 Red phosphor 61 Red colorant

Claims (3)

A light emitting element;
Containing a phosphor that is excited by light from the light emitting element to emit light of a predetermined wavelength, and covers the light emitting element;
A light-emitting device comprising: a light-emitting element colored with the same color as the light emitted from the phosphor, and a lens that transmits the light emitted from the light-emitting element and the phosphor. The light emitting element is
A blue light-emitting element having a light emission peak in a wavelength range of 430 to 480 nm,
The phosphor is
A red phosphor that emits light having an emission peak of 620 to 660 nm;
The lens is
The light emitting device according to claim 1, wherein the light emitting device is colored with a red colorant. The light emitting element is
A blue light-emitting element having a light emission peak in a wavelength range of 430 to 480 nm,
The phosphor is
It is a yellow phosphor that emits light having an emission peak wavelength of 570 to 590 nm,
The lens is
The light emitting device according to claim 1, wherein the light emitting device is colored with a yellow colorant.

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