JP5373754B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device that emits visible light by exciting a phosphor with ultraviolet rays.

  Conventionally, a fluorescent lamp is well known as a light emitting device that emits visible light by exciting a phosphor with ultraviolet rays. For example, as described in Patent Document 1 below, it has been proposed to apply a phosphor to the surface of an ultraviolet light emitting diode and excite the phosphor with ultraviolet rays to convert it into visible light.

Japanese Patent Laid-Open No. 10-12925

  In the case of fluorescent lamps, in general, used fluorescent lamps are crushed and directly landfilled as industrial waste, so that rare rare earth elements are hardly recycled. On the other hand, in the case of a light emitting diode, the light emitting diode chip is mainly encapsulated in an epoxy resin. However, since the epoxy resin absorbs ultraviolet rays, there is a problem that the light emission intensity of the light emitting diode is reduced. In addition, since the epoxy resin deteriorates by absorbing ultraviolet rays, there is a problem that the lifetime of the ultraviolet light emitting diode tends to be shorter than that of the visible light emitting diode. Further, although the light emitting surface of the light emitting diode is a curved surface, it is difficult to uniformly apply the phosphor on the curved surface, and there is a problem that the light emission intensity may appear different depending on the viewing direction.

  In the case of the fluorescent lamp and the light emitting diode, since the phosphor is applied to the inside of the glass tube or the surface of the element, once the phosphor is applied, the emission color cannot be freely changed thereafter. It was.

  Furthermore, there is a certain limit to the thickness of the phosphor applied, and the thickness may be non-uniform as described above. Therefore, the phosphor cannot absorb all of the ultraviolet rays and the ultraviolet rays leak slightly. there is a possibility. In that case, there was a problem that the human body may be adversely affected by leaked ultraviolet rays.

  The present invention has been made in order to solve the above-described problems of the conventional example, and in a light emitting device that emits visible light by exciting a phosphor with ultraviolet light emitted from an ultraviolet light source that generates ultraviolet light, deterioration due to ultraviolet light. Therefore, an object of the present invention is to provide a light emitting device that can emit light stably over a long period of time and suppresses leakage of ultraviolet rays to the outside.

In order to achieve the above object, a light emitting device of the present invention comprises an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence in response to light emitted from the ultraviolet light source. On the other hand, it is a molded body in which at least one kind of phosphor is dispersed in a stable material, and an ultraviolet absorbing layer containing an ultraviolet absorber in a silicone resin so as to face the light emitting surface of the fluorescent member or wherein the digits set an ultraviolet absorbing member.

  Another light-emitting device of the present invention includes an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence by receiving light emitted from the ultraviolet light source, and the fluorescent member is contained in a silicone resin. It is a laminated body in which different phosphors are dispersed, and an ultraviolet absorbing layer is provided so as to face the light emitting surface of the fluorescent member.

  Further, another light-emitting device of the present invention includes an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence by receiving light emitted from the ultraviolet light source, and the fluorescent member is contained in a silicone resin. A molded product obtained by mixing and dispersing at least one type of phosphor and at least one type of pigment, and an ultraviolet absorbing layer is provided so as to face the light emitting surface of the fluorescent member.

  Further, another light-emitting device of the present invention includes an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence by receiving light emitted from the ultraviolet light source, and the fluorescent member is contained in a silicone resin. And a laminate of at least one phosphor dispersed therein and at least one pigment dispersed therein.

  Further, another light-emitting device of the present invention is a light-emitting device in which an ultraviolet light-emitting diode chip is enclosed in a silicone resin molding in which at least one kind of phosphor is dispersed, and the light emission of the silicone resin molding is performed. An ultraviolet absorbing member is provided so as to face the surface.

  According to still another light emitting device of the present invention, an ultraviolet light emitting diode chip is enclosed in a silicone resin molded body, and at least one kind of fluorescent light is contained in the silicone resin so as to face the light emitting surface of the silicone resin molded body. A light-emitting device provided with a fluorescent member that is a molded body in which a body is dispersed, wherein an ultraviolet-absorbing member is provided so as to face the light emitting surface of the fluorescent member.

  Furthermore, the ultraviolet absorbing member may be a molded body in which an ultraviolet absorbent is dispersed in a silicone resin.

  According to the present invention, in a light-emitting device that emits visible light by exciting a phosphor with ultraviolet light emitted from an ultraviolet light source that generates ultraviolet light, the light-emitting device is less deteriorated by ultraviolet light and can emit light stably over a long period of time. And the light-emitting device which suppressed the leakage of the ultraviolet-ray outside can be provided.

  By providing an ultraviolet absorbing layer or an ultraviolet absorbing member so as to face the light emitting surface of the fluorescent member, it is possible to remove ultraviolet rays that have not been absorbed by the phosphor, and to prevent leakage of ultraviolet rays from the light emitting device to the outside. be able to.

  In addition, since the silicone resin that is stable to ultraviolet rays constituting the fluorescent member hardly absorbs ultraviolet rays and transmits as it is, the fluorescent member hardly deteriorates due to ultraviolet rays, and the ultraviolet rays that are converted into visible light by the phosphors. The ratio increases. As a result, the light emission intensity of the light emitting device itself is increased.

It is a figure which shows the structure of the light emitting diode which is 1st Embodiment. It is a figure which shows the structure of the modification of 1st Embodiment. It is a figure which shows the structure of the light emitting diode which is 2nd Embodiment. It is a figure which shows the structure of the illuminating device which is 3rd Embodiment. It is a figure which shows the measuring method of chromaticity of a fluorescent member made as an experiment, and luminance spectral spectrum distribution. It is a figure which shows the spectrum distribution of the light emission by Example 1 of a fluorescent member. It is a figure which shows the spectral spectrum distribution of light emission by Example 2 of a fluorescent member. It is a figure which shows the spectral spectrum distribution of light emission by Example 3 of a fluorescent member. It is a figure which shows the spectral spectrum distribution of light emission by Example 4 of a fluorescent member. It is a figure which shows the spectral distribution of the light emission by Example 5 of a fluorescent member.

(First embodiment)
FIG. 1 shows the configuration of a light-emitting diode 10 that is a first embodiment of the light-emitting device of the present invention. The light-emitting diode chip 11 that emits ultraviolet light is placed on a stem 13 provided substantially at the center of the base member 12 and enclosed in a silicone resin molded body 14. A phosphor 15 such as a rare earth element is dispersed in the silicone resin molded body 14.

  The ultraviolet rays emitted from the light emitting diode chip 11 are absorbed by the phosphor 15 and the phosphor 15 is excited. When the phosphor 15 is excited, it emits fluorescence having a predetermined spectral spectrum distribution according to its properties. As a result, visible light is output from the light emitting diode 10.

  In the first embodiment, instead of the conventionally used epoxy resin, a silicone resin having a property stable to ultraviolet rays is used, and since the deterioration due to ultraviolet rays is small, stable light emission over a long period of time. can do. Further, since the silicone resin itself hardly absorbs ultraviolet rays, most of the ultraviolet rays emitted from the light emitting diode chip 11 are absorbed by the phosphor. As a result, the light emission efficiency of the light emitting diode 10 itself is increased.

  In this way, by exciting the phosphor using ultraviolet rays, it becomes possible to obtain a color (spectral spectrum distribution) that cannot be obtained with a normal visible light emitting diode. The phosphor 15 may be a single type or a mixture of two or more types of phosphors. In particular, it is possible to obtain an arbitrary spectral spectrum distribution, for example, white light, by mixing and dispersing a plurality of types of phosphors as the phosphor 15. Further, the phosphor and the pigment may be mixed and dispersed in the silicone resin. In that case, since light of a specific wavelength is absorbed by the pigment, the light emission efficiency of the light emitting diode 10 itself is slightly lowered, but there is an effect that a light emitting diode closer to a desired color can be obtained.

  Note that the ultraviolet light emitted from the light emitting diode chip 11 can hardly be absorbed by the phosphor 15, and a part of the ultraviolet light is included in the emitted light from the light emitting diode 10. Therefore, as shown in FIG. 2, a resin-made ultraviolet absorbing member 16 containing an ultraviolet absorber is provided outside the silicon resin molded body 14. As the ultraviolet absorber, 2- (2-hydroxy-3.5-di-t-butylphenyl) -5-chlorobenzotriazole or the like can be used. By using the ultraviolet absorbing member 16 in this way, ultraviolet rays are hardly emitted from the light emitting diode 10, so that the possibility of adversely affecting the human body becomes extremely small.

  In addition, when recycling the used light emitting diode 10, the silicone resin molding 14 can be grind | pulverized and it can reuse as a resin pellet containing fluorescent substance. Moreover, mixing the phosphor and the ultraviolet absorbing member can be prevented by using the ultraviolet absorbing member 16 as a separate member as described above.

(Second Embodiment)
The structure of the light emitting diode 20 which is 2nd Embodiment of the light-emitting device of this invention is shown in FIG. The light-emitting diode chip 21 that emits ultraviolet light is placed on a stem 23 provided substantially at the center of the base member 22, and is enclosed in a silicone resin molded body 24. Unlike the case of the first embodiment, phosphors such as rare earth elements are not dispersed in the silicone resin molded body 24. On the other hand, a resin-made fluorescent member 26 including a fluorescent body 25 is provided outside the silicon resin molded body 24. As the material of the fluorescent member, it is preferable to use a silicone resin having a property stable to ultraviolet rays.

  The ultraviolet rays emitted from the light emitting diode chip 21 are absorbed by the phosphor 25 and the phosphor 25 is excited. When the phosphor 25 is excited, it emits fluorescence having a predetermined spectral spectrum distribution according to its properties. As a result, visible light is output from the fluorescent member 26 of the light emitting diode 20.

  The second embodiment is substantially the same as the ultraviolet light emitting diode covered with the fluorescent member 26 serving as a cap. That is, the fluorescent member 26 including the fluorescent material is a separate member from the silicone resin molded body 24, and a plurality of types of fluorescent members 26 having different types of fluorescent materials, phosphor densities, thicknesses, and the like are prepared. By exchanging, it becomes possible to obtain a visible light emitting diode having an arbitrary spectral spectrum distribution based on a single type of ultraviolet light emitting diode.

  Further, since the fluorescent member 26 is a molded body, it is easy to make the thickness uniform and control the thickness as compared with the case where the fluorescent material is applied as in the conventional example. Furthermore, by making the fluorescent member 26 into a cap shape, the directivity of the light emitting diode can be relaxed. That is, the ultraviolet light emitted from the light emitting diode chip 21 is incident on the fluorescent member 26, but not all the light is directly incident on the fluorescent member 26, but a part of the light is reflected on the surface of the fluorescent member 26 and silicone. Return to the resin molding 24 side. The light reflected toward the silicone resin molded body 24 is reflected again by the surface of the silicone resin molded body 24 and travels toward the fluorescent member 26 side. Since the same phenomenon as described above is repeated on the surface of the fluorescent member 26, by repeating such reflection infinitely, the ultraviolet light emitted from the light emitting diode chip 21 is scattered and enters almost the entire fluorescent member 26. Since the fluorescent member 26 contains the phosphor almost uniformly, it is considered that almost the entire fluorescent member 26 becomes a light source and emits light.

  When the used light emitting diode 20 is recycled, the fluorescent member 26 can be removed and reused as it is, or it can be crushed and reused as a resin pellet containing a phosphor.

  Further, similarly to the modification of the first embodiment shown in FIG. 2, a resin-made ultraviolet absorbing member (not shown) that includes an ultraviolet absorber is provided outside the fluorescent member 26. Since the phosphor 25 is the same as the phosphor 15 in the first embodiment, the description thereof is omitted.

(Third embodiment)
The structure of the illuminating device 30 which is 3rd Embodiment is shown in FIG. The illumination device 30 is provided in a plurality of ultraviolet light emitting diodes 31 arranged in a direction perpendicular to the paper surface, a reflecting plate 32 that reflects light emitted from the light emitting diodes 31 in a predetermined direction, and an opening of the reflecting plate 32, for example. The fluorescent member 33 is used.

  A known ultraviolet light emitting diode may be used as the light emitting diode 31, but the one using a silicone resin instead of the epoxy resin as in the second embodiment is preferable. Further, the light emitting diode 31 itself does not need to contain a phosphor.

  The fluorescent member 33 is obtained by molding a phosphor dispersed in a silicone resin into a plate shape or a film shape, and may be a single layer or a laminate. The phosphor 34 is the same as the phosphor 15 in the first embodiment, and may be a single type or a mixture of two or more types of phosphors. It is possible to emit light having an arbitrary spectral spectrum distribution by mixing and dispersing a plurality of types of phosphors as the phosphor 34, or by laminating layers containing different types of phosphors. In particular, the lighting device 30 is preferably white, daylight color, or light bulb color. Further, similarly to the modification of the first embodiment shown in FIG. 2, a resin-made ultraviolet absorbing member (not shown for obvious explanation) including an ultraviolet absorber is provided outside the fluorescent member 33.

  When the lighting device 30 is disposed of, the fluorescent member 33 can be easily separated from other parts. Therefore, the fluorescent member 33 can be removed and reused as it is, or crushed and reused as a resin pellet containing a phosphor. can do.

(Specific examples of phosphors)
Next, the fluorescent member used in each of the above-described embodiments was prototyped, and the chromaticity and luminance spectral spectrum distribution were measured. The results are shown below. The measurement is performed by the method shown in FIG. 5, the fluorescent member is molded into a parallel flat plate with a predetermined thickness, black light (manufactured by Stanley) is used as an ultraviolet light source, the ultraviolet ray is irradiated to the fluorescent member, and the light emitting surface is spectrally separated. It measured with radiation thermometer PR-704 (made by Photo Research).

2 parts by weight of YS-A (manufactured by Nemoto Special Chemical Co., Ltd.), which is an inorganic phosphor, was dispersed in silicone rubber and heated to form a sheet-like fluorescent member having a thickness of 0.5 mm. This fluorescent member was irradiated with ultraviolet rays. As a result, the chromaticity was red with x = 0.5249 and y = 0.2711, and the luminance was 158.1 Cd / m ² . FIG. 6 shows the spectral spectrum distribution of light emission at this time. In FIG. 6, the horizontal axis represents wavelength and the vertical axis represents radiance (the same applies to the following examples).

Two parts by weight of SPE-A (manufactured by Nemoto Special Chemical Co., Ltd.), which is an inorganic phosphor, was dispersed in silicone rubber, and heated to form a sheet-like fluorescent member having a thickness of 0.5 mm. This fluorescent member was irradiated with ultraviolet rays. As a result, the chromaticity was blue with x = 0.1543 and y = 0.0372, and the luminance was 54.4 Cd / m ² . FIG. 7 shows the spectral spectrum distribution of light emission at this time.

One part by weight of SINLOIHI COLOR FZ-5005 (manufactured by Sinloihi Co., Ltd.), an organic phosphor, was dispersed in silicone rubber and heated to form a sheet-like fluorescent member having a thickness of 0.5 mm. This fluorescent member was irradiated with ultraviolet rays. As a result, the chromaticity was green with x = 0.2462 and y = 0.5370, and the luminance was 260.8 Cd / m ² . FIG. 8 shows the spectral spectrum distribution of light emission at this time.

One part by weight of organic phosphor NKP-8303 (manufactured by Nippon Fluorescent Chemical Co., Ltd.) was dispersed in silicone rubber, and heated to form a sheet-like fluorescent member having a thickness of 0.5 mm. This fluorescent member was irradiated with ultraviolet rays. As a result, the chromaticity was red with x = 0.5325 and y = 0.080, and the luminance was 175.8 Cd / m ² . FIG. 9 shows the spectral spectrum distribution of light emission at this time.

As a first phosphor layer, 1 part by weight of SINLOIHI COLOR FZ-5005 (manufactured by Sinloihi), which is an organic phosphor, is dispersed in silicone rubber and heated to form a sheet-like phosphor member having a thickness of 0.25 mm. . As a second phosphor layer, 2 parts by weight of SPE-A (manufactured by Root Special Chemical Co.), which is an inorganic phosphor, is dispersed in silicone rubber, and heated to form a sheet-like phosphor member having a thickness of 0.5 mm. . As the third phosphor layer, 2 parts by weight of inorganic phosphor YS-A (manufactured by Root Special Chemical Co., Ltd.) was dispersed in silicone rubber, and heated to form a sheet-like phosphor member having a thickness of 0.5 mm. . These first to third phosphor layers were laminated to form a fluorescent member, and the fluorescent member was irradiated with ultraviolet rays. As a result, the chromaticity was white with x = 0.3282 and y = 0.3165, and the luminance was 263.4 Cd / m ² . FIG. 10 shows the spectral spectrum distribution of the light emission at this time.

(Other embodiments)
In each of the above embodiments, in consideration of recyclability, a material in which a phosphor is dispersed in a silicone resin is used as a material, and a silicone resin molded body or a fluorescent member is molded. However, the present invention is limited to this. Although not recyclable, the phosphor may be applied to the light exit surface of an ultraviolet light source such as an ultraviolet light emitting diode. Similarly, in each of the above embodiments, the ultraviolet absorbing member is molded using a material in which an ultraviolet absorbent is dispersed in a silicone resin, but the present invention is not limited to this. An ultraviolet absorber may be applied to the light emitting surface of the body or the fluorescent member. Furthermore, although the light emission intensity as a light emitting device is reduced, a silicone resin molded body or a fluorescent member may be molded using a mixture of a phosphor and an ultraviolet absorber mixed in a silicone resin.

  As described above, according to the light emitting device of the present invention, the light source includes an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence by receiving light emitted from the ultraviolet light source. Since it is a molded body in which at least one kind of phosphor is dispersed in a stable material, the ultraviolet light source and the fluorescent member containing the phosphor are separated, and when the light emitting device is disposed of, The ultraviolet light source and the fluorescent member can be separated, and the phosphor (rare earth element) can be recovered and recycled. Further, since the fluorescent member is formed into a molded body, it becomes easy to make the thickness uniform or control the thickness, and a light emitting device with less direction dependency can be obtained.

  According to another light-emitting device of the present invention, the light-emitting device includes an ultraviolet light source that generates ultraviolet light and a fluorescent member that emits fluorescence when receiving light emitted from the ultraviolet light source, and the fluorescent member is stable against ultraviolet light. In the same manner, the ultraviolet light source and the fluorescent member can be separated at the time of disposal of the light emitting device. Collection and recycling are possible and easy. In addition, since the fluorescent member is, for example, a laminated body of films, it is easy to make the thickness uniform or control the thickness, and it is possible to obtain a light emitting device with less direction dependency.

  According to yet another light-emitting device of the present invention, the light-emitting device includes an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence upon receiving light emitted from the ultraviolet light source. Since it is a molded product in which at least one kind of phosphor and at least one kind of pigment are mixed and dispersed in a stable material, similarly, in the disposal of the light emitting device, an ultraviolet light source, a fluorescent member, Can be separated, and the phosphor can be collected and recycled. Further, since the fluorescent member is formed into a molded body, it becomes easy to make the thickness uniform or control the thickness, and a light emitting device with less direction dependency can be obtained.

  According to yet another light-emitting device of the present invention, the light-emitting device includes an ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence upon receiving light emitted from the ultraviolet light source. Since it is a laminate of a material in which at least one kind of phosphor is dispersed in a stable material and at least one kind of pigment is dispersed, similarly, in the disposal of the light emitting device, an ultraviolet light source and The fluorescent member can be separated, and the phosphor can be collected and recycled. In addition, since the fluorescent member is, for example, a laminated body of films, it is easy to make the thickness uniform or control the thickness, and it is possible to obtain a light emitting device with less direction dependency.

  In addition, since the material that is stable to ultraviolet rays (such as silicone resin) that constitutes the fluorescent member hardly absorbs ultraviolet rays and transmits as it is, the fluorescent member is hardly deteriorated by ultraviolet rays, and is made visible light by the phosphor. The percentage of ultraviolet rays that are converted increases. As a result, the light emission intensity of the light emitting device itself is increased.

  Furthermore, by combining two or more kinds of phosphors, an arbitrary spectral spectrum distribution can be obtained, and the degree of freedom as a light emitting device is increased. Alternatively, it is possible to change the emission color of the light-emitting device by preparing a plurality of fluorescent members having different phosphor types, phosphor densities, thicknesses, and the like and appropriately replacing the fluorescent members.

  Further, by providing an ultraviolet absorbing layer so as to face the light emitting surface of the fluorescent member, ultraviolet rays that are not absorbed by the phosphor can be removed by the ultraviolet absorbing layer, and ultraviolet rays leak from the light emitting device to the outside. Almost disappear. As a result, there is almost no possibility that the human body will be adversely affected by ultraviolet rays.

  According to still another light-emitting device of the present invention, the ultraviolet light-emitting diode chip is enclosed in a silicone resin molding in which at least one kind of phosphor is dispersed. At this time, by separating the silicone resin molded body from other parts, the phosphor contained therein can be recycled. In addition, since the silicone resin is less deteriorated by ultraviolet rays, visible light can be emitted stably over a long period of time.

  Further, by providing the ultraviolet absorbing member so as to face the light emitting surface of the silicone resin molded body, leakage of ultraviolet rays from the light emitting device can be almost eliminated.

  According to yet another light-emitting device of the present invention, the ultraviolet light-emitting diode chip is enclosed in a silicone resin molded body, and at least one kind of the silicone resin molded body is opposed to the light emitting surface of the silicone resin molded body. Since the fluorescent member is provided as a molded product in which the fluorescent material is dispersed, the fluorescent member contained in the fluorescent member is separated by separating the fluorescent member from other parts during disposal of the light emitting device. The body can be recycled. In addition, since the silicone resin is less deteriorated by ultraviolet rays, visible light can be emitted stably over a long period of time.

  Further, by combining two or more kinds of phosphors, an arbitrary spectral spectrum distribution can be obtained, and the degree of freedom as a light emitting device is increased. Alternatively, it is possible to change the emission color of the light emitting device by preparing a plurality of fluorescent members having different phosphor types, phosphor densities, thicknesses, etc., and appropriately replacing the fluorescent members. .

  Further, by providing the ultraviolet absorbing member so as to face the light emission surface of the fluorescent member, leakage of ultraviolet rays from the light emitting device can be almost eliminated.

  Further, as a UV absorbing member, by using a molded body in which a UV absorber is dispersed in a silicone resin, a portion containing a phosphor and a portion containing a UV absorber can be separated during disposal of the light emitting device. This makes it easier to separate recycled materials.

10: Light-emitting diode 11: Light-emitting diode chip 14: Silicone resin molding 15: Phosphor 16: Ultraviolet absorbing member 20: Light-emitting diode 21: Light-emitting diode chip 24: Silicone resin molding 25: Phosphor 26: Fluorescent member 30: Illumination Device 31: Light emitting diode 32: Reflector 33: Fluorescent member 34: Phosphor

Claims (7)

An ultraviolet light source that generates ultraviolet light, and a fluorescent member that emits fluorescence in response to light emitted from the ultraviolet light source,
The fluorescent member is a molded body in which at least one type of phosphor is dispersed in a silicone resin,
The so as to face the light emitting surface of the fluorescent member, the light emitting device, characterized in that an ultraviolet absorbing layer or UV-absorbing member which contains an ultraviolet absorber digits set in a silicone-based resin. Before Symbol fluorescent member emitting light device according to claim 1 is a laminate but was dispersed with different phosphors, respectively in a silicone-based resin. Before Symbol fluorescent member emitting light device according to claim 1 which is molded but was mixed and dispersed at least one pigment and at least one phosphor in a silicone-based resin. Before Symbol fluorescent member, at least one phosphor and which is dispersed at least one light emission device of claim 1 Ru laminate der despite a pigment dispersed in a silicone-based resin. The light-emitting device according to claim 1, wherein the ultraviolet light source is an ultraviolet light-emitting diode chip, and the fluorescent member is a silicone-based resin sealing body containing the phosphor that encapsulates the ultraviolet light-emitting chip . The ultraviolet light source is an ultraviolet light emitting diode chip, and the ultraviolet light emitting chip is encapsulated in a silicone resin encapsulant;
The light emitting device according to claim 1, wherein the fluorescent member is disposed so as to cover the silicone-based resin sealing body . The light-emitting device according to claim 1, wherein the fluorescent member is a plate-shaped or film-shaped molded body .

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