JP2012243618A - Light source device and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of achieving a sufficiently high luminance as compared with a conventional one.
SOLUTION: A solid-state light source 5 that emits light of a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and a longer wavelength than an emission wavelength of the solid-state light source 5 that is excited by excitation light from the solid-state light source 5. A phosphor layer 2 including at least one first phosphor that emits fluorescence having a wavelength shorter than that of red, and a surface of the phosphor layer 2 on which excitation light from the solid light source 5 is incident. A position where the solid light source 5 and the phosphor layer 2 are spatially separated from each other, and a heat dissipation substrate 6 provided on the opposite side of the surface, and a bonding layer 17 for bonding the phosphor layer 2 and the heat dissipation substrate 6. A light source device that takes out at least fluorescence by a reflection method from the surface of the phosphor layer 2 on which the excitation light from the solid light source 5 is incident, and the bonding layer 17 has excitation from the solid light source 5. When excited by light, the first phosphor has a longer wavelength than the emission wavelength. Phosphor particles that emit light are included.
[Selection] Figure 3

Description

  The present invention relates to a light source device and an illumination device.

  A light source device combining an optical semiconductor such as an LED and a phosphor layer has been widely used. However, in recent years, the brightness has been increased, and its application range such as general lighting and automobile headlamps has been expanded. It is considered that such light source devices will continue to be widely used in various applications by increasing the luminance.

  As a means for increasing the brightness of a light source device combining such an optical semiconductor and a phosphor layer, it is conceivable to increase the excitation light intensity from the optical semiconductor by supplying a large current to the optical semiconductor. Heat is generated in the phosphor layer, and in the phosphor layer, the fluorescence intensity decreases due to discoloration of the resin component or temperature quenching of the phosphor. Therefore, as a result, the emission intensity is saturated and decreased, and it is difficult to increase the luminance of the light source device that combines the optical semiconductor and the phosphor layer.

  Here, the discoloration of the resin component in the phosphor layer means that the phosphor layer is usually formed into a fixed shape with good reproducibility. This is a phenomenon in which the resin component is discolored when the resin component is heated to about 200 ° C. or higher. Since the resin component is inherently transparent, if the resin component is discolored by heat, it absorbs a part of the excitation light from the optical semiconductor and the fluorescence from the phosphor layer, which prevents high brightness. It was.

  The temperature quenching of the phosphor is a phenomenon in which the fluorescence intensity decreases when the phosphor is heated. If the fluorescence intensity decreases due to temperature quenching, the energy that has not been converted to fluorescence becomes heat, so the amount of heat generated by the phosphor increases, the temperature of the phosphor rises, temperature quenching proceeds, and the fluorescence intensity further decreases. This happens. For this reason, temperature quenching of the phosphors generated by heat has also been a factor that hinders high brightness.

  In order to solve these problems, Patent Document 1 proposes a light source using a phosphor layer that does not contain a resin in the phosphor layer. In this case, since the phosphor layer does not contain a resin component, discoloration does not occur, and since the phosphor layer is made of a ceramic layer of phosphor with low temperature sensitivity, temperature quenching does not occur, so high brightness can be achieved. is there. Further, as shown in FIG. 1, the phosphor layer 92 is directly bonded to the optical semiconductor (solid light source) 95 to dissipate heat generated in the phosphor layer 92 to the optical semiconductor (solid light source) 95 side. It was.

JP 2006-005367 A

  Incidentally, in the conventional light source device in which the optical semiconductor (solid light source) 95 and the phosphor layer 92 are directly bonded as shown in FIG. 1, the phosphor layer excited by the excitation light from the optical semiconductor (solid light source) 95. The light emitted from the light 92 (fluorescence) is emitted to the side opposite to the optical semiconductor (solid light source) 95 side, and the light semiconductor (solid light source) 95 that is not absorbed by the phosphor layer 92 and passes through the phosphor layer 92. The excitation light from is used. That is, the light source device of FIG. 1 is of a transmissive type that uses light transmitted through the phosphor layer 92.

  Here, when light emitted from the phosphor layer 92 is considered, there is also light reflected from the interface with the phosphor layer 92 together with the transmitted light and returning to the optical semiconductor (solid light source) 95 side, that is, reflected light. This light (reflected light) is re-absorbed by the optical semiconductor (solid light source) 95, so that there is a problem that the light cannot be used as illumination light.

  1 is intended to dissipate the heat of the phosphor layer 92 to the optical semiconductor (solid light source) 95 side, but the excitation light intensity of the optical semiconductor (solid light source) 95 is increased. Since heat is generated not only in the phosphor layer 92 but also in the optical semiconductor (solid light source) 95, the heat generated in the phosphor layer 92 is dissipated from the side of the optical semiconductor (solid light source) 95 that is also generating heat. There was a problem that the efficiency of was not good.

  As described above, the light source device shown in FIG. 1 has a limitation on high luminance because it is of a transmissive type and the efficiency of heat dissipation with respect to the heat generation of the phosphor layer 92 is not good.

  An object of the present invention is to provide a light source device and an illuminating device capable of achieving a sufficiently high luminance as compared with the conventional art.

  In order to achieve the above object, the invention described in claim 1 is excited by a solid light source that emits light of a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and excitation light from the solid light source. A phosphor layer including at least one first phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the solid light source and a wavelength shorter than red; and the solid light source among the surfaces of the phosphor layer A heat dissipation substrate provided on a surface opposite to the surface on which the excitation light from the light is incident, and a bonding layer for bonding the phosphor layer and the heat dissipation substrate, the solid-state light source and the phosphor layer, Is a light source device that takes out at least fluorescence in a reflective manner from the surface of the phosphor layer on the side on which the excitation light from the solid light source is incident. , When excited by excitation light from the solid state light source, It is characterized in that it contains the phosphor particles emitting fluorescence of a wavelength longer than the emission wavelength of the first phosphor.

  According to a second aspect of the present invention, in the light source device according to the first aspect, a resin is used for the bonding layer.

  According to a third aspect of the present invention, in the light source device according to the first or second aspect, the phosphor layer is a phosphor ceramic.

  According to a fourth aspect of the present invention, in the light source device according to any one of the first to third aspects, the light source device is a fluorescent light having the phosphor layer, the bonding layer, and the heat dissipation substrate. It is characterized by having a rotating body.

  The invention according to claim 5 is an illumination device characterized by using the light source device according to any one of claims 1 to 4.

  According to the first to fifth aspects of the present invention, the solid light source that emits light having a predetermined wavelength in the wavelength region from ultraviolet light to visible light, and the solid that is excited by the excitation light from the solid light source. A phosphor layer including at least one first phosphor that emits fluorescence having a wavelength longer than that of the light source and shorter than that of red, and a surface of the phosphor layer from the solid-state light source. A heat dissipation substrate provided on a surface opposite to the surface on which excitation light is incident; and a bonding layer that bonds the phosphor layer and the heat dissipation substrate, wherein the solid-state light source and the phosphor layer are in space. Since at least the fluorescence is taken out from the surface of the phosphor layer on the side where the excitation light from the solid light source is incident by the reflection method, the brightness is sufficiently increased as compared with the conventional case. be able to.

  In particular, according to the first to fifth aspects of the present invention, the bonding layer is fluorescent with a wavelength longer than the emission wavelength of the first phosphor when excited by excitation light from the solid-state light source. Since the solid-state light source emits blue light as, for example, visible light, the phosphor layer containing, for example, a yellow phosphor is irradiated with the blue light from the solid-state light source. Thus, when white or other illumination light is obtained as the reflected light, it is possible to prevent a situation in which the red component is insufficient in the illumination light (its spectrum) as the reflected light, and to adjust the emission chromaticity.

  According to a fourth aspect of the present invention, in the light source device according to any one of the first to third aspects, the light source device includes the phosphor layer, the bonding layer, and the heat dissipation substrate. Rotating the phosphor layer and the bonding layer with respect to the solid light source can disperse the place where the excitation light from the solid light source hits and suppress the heat generation at the light irradiation unit. This makes it possible to further increase the brightness.

It is a figure which shows the conventional light source device. It is a figure which shows the light source device described in the prior application (Japanese Patent Application No. 2009-286397) of this application by the present applicant. It is a figure which shows the example of 1 structure of the light source device of this invention. It is a figure which shows the light source device comprised so that a red fluorescent substance might be included in a fluorescent substance layer with yellow fluorescent substance and a green fluorescent substance, for example. For example, it is a figure which shows the structure which laminates | stacks the fluorescent substance layer containing a red fluorescent substance on the side near a solid light source rather than the fluorescent substance layer containing the fluorescent substance of yellow and green. For example, a phosphor layer containing yellow and green phosphors and a phosphor layer containing red phosphors on the side closer to the solid light source than the phosphor layer containing yellow and green phosphors, for example, are stacked. It is a figure which shows a structure. It is a figure which shows the example comprised as a reflection type fluorescence rotary body which rotates a fluorescent substance layer around a rotating shaft.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a diagram showing the light source device described in the prior application (Japanese Patent Application No. 2009-286397) of the present application by the applicant of the present application. Referring to FIG. 2, the light source device 10 is excited by a solid light source 5 that emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and excitation light from the solid light source 5. The phosphor layer 2 includes at least one type of phosphor that emits fluorescence having a wavelength longer than the emission wavelength of the light source 5, and the solid light source 5 and the phosphor layer 2 are arranged spatially separated from each other.

  Here, the phosphor layer 2 may include a resin component (for example, a phosphor dispersed and coated in a high transparent resin such as a silicone resin) or a glass-sealed one. However, a material that does not substantially contain a resin component (such as phosphor ceramics) can also be used.

  Further, a substrate (heat radiating substrate) 6 having light reflectivity and thermal conductivity is provided on the surface of the phosphor layer 2 opposite to the surface on which the excitation light is incident. The heat radiating substrate 6 is joined by the joint 7. Here, a material having light reflectivity and thermal conductivity may be used for the joint portion 7 as well.

  Further, in the light source device 10, light such as fluorescent light (excitation is used using reflection by a reflection surface provided on the opposite side of the surface of the phosphor layer 2 from the surface on which excitation light from the solid light source 5 is incident. A method of taking out light (fluorescence) (hereinafter referred to as a reflection method) is employed.

  As described above, the light source device 10 is basically characterized in that the solid light source 5 and the phosphor layer 2 are spatially separated and light emission is used in a reflective manner.

  That is, as in the conventional light source device shown in FIG. 1, when the phosphor layer 92 is in contact with the solid light source 95, both the phosphor layer 92 and the solid light source 95 are used even if the luminance is increased. However, in the light source device 10 of FIG. 2, the phosphor layer 2 is arranged away from the solid light source 5 to increase the brightness. Also in this case, it becomes possible to dissipate heat from the phosphor layer 2 to the low-temperature heat dissipation substrate 6 through the joint portion 7, and the efficiency of heat dissipation from the phosphor layer 2 is shown in FIG. Compared with the conventional light source device, it can be remarkably enhanced.

  Further, in the conventional light source device shown in FIG. 1, among the excitation light from the solid light source 95 and the fluorescence from the phosphor layer 92, the fluorescence emitted to the side opposite to the solid light source 95 and the phosphor layer 92 Excitation light from a solid light source 95 that is transmitted without being absorbed is used. In other words, the transmission method is used. Here, in the transmission method, when the emitted light from the phosphor layer 92 is considered, the excitation light is reflected at the interface with the phosphor layer 92 together with the transmitted light and returns to the solid light source 95 side, that is, reflected. There is also light, and this reflected light is reabsorbed by the solid light source 95 and becomes light that cannot be used as illumination light. Further, since the fluorescence from the phosphor layer 92 is emitted from both sides of the phosphor layer 92, the light emitted to the solid light source 95 side cannot be used. Thus, in the transmission method, the light use efficiency is reduced. In addition, in the transmission method, in order to obtain illumination light with a desired chromaticity, it is necessary to increase the thickness of the phosphor layer 92, and the distance from the phosphor layer 92 to the solid light source 95 becomes long. It was disadvantageous in dissipating the heat from 92 to the solid light source 95.

  On the other hand, in the light source device 10 of FIG. 2, the light (excitation light, fluorescence) emitted to the side opposite to the solid light source 5 is reflected by the reflective surface (for example, the reflective surface of the substrate 6) to the solid light source 5 side. Since the method is employed, all of the light emission (fluorescence) from the phosphor layer 2 excited by the excitation light from the solid light source 5 (that is, the fluorescence emitted to the solid light source 5 side) and the phosphor layer 2 All of the excitation light from the solid light source 5 that has not been absorbed (that is, the reflected light of the light from the solid light source 5 that has not been absorbed by the phosphor layer 2) can be used as illumination light (that is, excitation light, fluorescence). Both of them can be used as illumination light efficiently), so that the light use efficiency can be remarkably increased and the brightness can be increased. In contrast to the transmission type, in the reflection type, even if the thickness of the phosphor layer 2 is less than half, the optical path lengths in the phosphor layer 2 are equal, and light of the same chromaticity can be obtained. In addition, the distance from the phosphor layer 2 to the substrate 6 is shortened, which is advantageous in terms of heat dissipation.

  As described above, in the light source device 10 of FIG. 2, the solid light source 5 and the phosphor layer 2 are basically spatially separated and light emission is used in a reflective manner. High brightness can be achieved.

  Furthermore, in the light source device 10 of FIG. 2, when the phosphor layer 2 that does not substantially contain a resin component is used, there is no discoloration due to heat, light absorption is small, and temperature quenching is unlikely to occur. Therefore, it is possible to further increase the brightness.

  Here, the phosphor layer 2 substantially not containing a resin component means that the resin component normally used for forming the phosphor layer is 5 wt% or less of the phosphor layer. As a material for realizing such a phosphor layer, a phosphor powder dispersed in glass, a glass phosphor in which a luminescent center ion is added to a glass matrix, a phosphor single crystal, or a phosphor polycrystal (hereinafter referred to as a phosphor) And phosphor ceramics). The phosphor ceramic is a lump of phosphor that is formed by firing a material into an arbitrary shape before firing in the phosphor manufacturing process. Phosphor ceramics may use an organic substance as a binder in the molding process during the manufacturing process. However, an organic resin component is included in the fired phosphor ceramic because a degreasing process is provided after molding to burn off the organic components. Remains only 5 wt% or less. Therefore, since the phosphor layer mentioned here does not substantially contain a resin component and is composed only of an inorganic substance, discoloration due to heat does not occur. In addition, glass or ceramics made of only an inorganic substance generally has a higher thermal conductivity than a resin, and is therefore advantageous in heat dissipation from the phosphor layer 2 to the substrate 6. In particular, phosphor ceramics generally have higher thermal conductivity than glass and are less expensive to manufacture than single crystals. Therefore, it is preferable to use them for the phosphor layer 2.

  Further, in the light source device 10 of FIG. 2, the heat dissipation substrate 6 includes light (emission (fluorescence) from the phosphor layer 2 excited by excitation light from the solid light source 5 and solids not absorbed by the phosphor layer 2). The role of the reflecting surface with respect to the light from the light source 5, the role of radiating the heat dissipated from the phosphor layer 2 to the outside, and the role of the support substrate of the phosphor layer 2 are also assumed. For this reason, high light reflection characteristics, heat transfer characteristics, and workability are required. The heat dissipation substrate 6 can be a metal substrate, oxide ceramics such as alumina, non-oxide ceramics such as aluminum nitride, etc., but a metal substrate having particularly high light reflection characteristics, heat transfer characteristics, and workability is used. It is desirable to be done.

  By the way, in the light source device 10 of FIG. 2, the phosphor layer 2 includes at least one kind of phosphor that is excited by excitation light from the solid light source 5 and emits fluorescence having a longer wavelength than the emission wavelength of the solid light source 5. It is out. Specifically, when the solid light source 5 emits blue light as, for example, visible light, when the phosphor layer 2 contains, for example, a yellow phosphor, the blue light from the solid light source 5 is fluorescent. When irradiating the body layer 2, illumination light such as white can be obtained as reflected light.

  However, the solid light source 5 emits blue light as, for example, visible light, and the blue light from the solid light source 5 is irradiated as excitation light to the phosphor layer 2 containing, for example, a yellow phosphor, and reflected light. When obtaining illumination light such as white, there is a problem that the illumination light (its spectrum) as reflected light lacks a red component.

  The present invention has been made to solve this problem. The solid light source 5 emits blue light as, for example, visible light, and the blue light from the solid light source 5 includes, for example, a yellow phosphor. When illuminating the phosphor layer 2 to obtain illumination light such as white as reflected light, it is possible to prevent a situation in which the red component is insufficient in the illumination light (the spectrum thereof) as reflected light, and the emission chromaticity It is an object of the present invention to provide a light source device and an illumination device capable of adjusting the light intensity.

  FIG. 3 is a diagram showing a configuration example of the light source device of the present invention. In FIG. 3, portions corresponding to those in FIG. Referring to FIG. 3, the light source device 20 is excited by a solid light source 5 that emits light having a predetermined wavelength in a wavelength region from ultraviolet light to visible light, and excitation light from the solid light source 5. A phosphor layer 2 including at least one first phosphor (for example, a yellow or green phosphor) that emits fluorescence having a wavelength longer than the emission wavelength of the light source 5 and a wavelength shorter than red; Of the surface of the phosphor layer 2, the heat dissipation substrate 6 provided on the surface opposite to the surface on which the excitation light from the solid light source 5 is incident is joined to the phosphor layer 2 and the heat dissipation substrate 6. The solid-state light source 5 and the phosphor layer 2 are spatially separated from each other.

  Here, the phosphor layer 2 may include a resin component (for example, a phosphor dispersed and coated in a high transparent resin such as a silicone resin) or a glass-sealed one. However, a material that does not substantially contain a resin component (such as phosphor ceramics) can also be used. In particular, when a phosphor layer 2 that does not substantially contain a resin component (such as phosphor ceramics) is used, as described above, there is no discoloration due to heat, less light absorption, and temperature quenching. Since it does not occur easily, it is possible to further increase the brightness, which is preferable.

  Further, the heat radiating substrate 6 is preferably made of a material having light reflectivity and thermal conductivity similar to the light source device 10 of FIG.

  Moreover, in this light source device 20, the reflection by the reflective surface (for example, heat dissipation board | substrate 6) provided in the opposite side to the surface where the excitation light from the solid light source 5 injects among the surfaces of the fluorescent substance layer 2 is used. A method of taking out light such as fluorescence (excitation light, fluorescence) (hereinafter referred to as a reflection method) is employed.

  By the way, in the light source device 20 of FIG. 3, in order to solve the problem in the light source device 10 of FIG. 2 described above, the phosphor layer 2 is excited by the excitation light from the solid light source 5 and is emitted from the emission wavelength of the solid light source 5. In addition, a material including at least one kind of first phosphor (for example, yellow, green phosphor) that emits fluorescence having a longer wavelength and shorter than red is used. When excited by excitation light from the solid-state light source 5, a phosphor containing phosphor particles (for example, red phosphor particles) that emit fluorescence having a wavelength longer than the emission wavelength of the first phosphor is used.

Here, a resin is used for the bonding layer 17. Further, the phosphor particles contained in the bonding layer 17 (that is, phosphor particles that emit fluorescence having a wavelength longer than the emission wavelength of the first phosphor (for example, red phosphor particles)) are thermally conductive. (For example, CaAlSiN ₃ : Eu ²⁺ and Ca ₂ Si ₅ N ₈ : Eu ²⁺ described later) are used. That is, in the present invention, the phosphor particles included in the bonding layer 17 (that is, phosphor particles that emit fluorescence having a wavelength longer than the emission wavelength of the first phosphor (for example, red phosphor particles)) It also has a role as a thermally conductive filler. Here, regarding ceramics, it is known that a substance having a strong covalent bond such as aluminum nitride or silicon nitride exhibits high thermal conductivity. It is also known that phosphors based on ceramics with strong covalent bonding exhibit long wavelength wavelength emission in the visible light region such as green to red. Accordingly, the red phosphor is expected to have a high thermal conductivity and is desirable as a thermally conductive filler.

  In the light source device 20 of FIG. 3 having such a configuration, when the solid light source 5 emits blue light, for example, as visible light, yellow, green phosphors, for example, are emitted using blue light from the solid light source 5 as excitation light. When illuminating the included phosphor layer 2 to obtain illumination light such as white as reflected light, illumination light as reflected light is obtained only from, for example, yellow and green phosphors included in the phosphor layer 2. In the light source device 20 of FIG. 3, when the bonding layer 17 is excited by excitation light from the solid light source 5, the first phosphor By using phosphor particles (for example, red phosphor particles) that emit fluorescence (for example, red light) having a wavelength longer than the light emission wavelength, the illumination light (spectrum) as reflected light is used. Is the fluorescence from the bonding layer 17 (example If the red light) is taken into account, it is possible to solve the shortage of a red component in the illumination light as reflected light (spectrum), it is possible to adjust the light emission chromaticity.

  The phosphor particles contained in the bonding layer 17 (that is, phosphor particles that emit fluorescence having a longer wavelength than the emission wavelength of the first phosphor (for example, red phosphor particles)) are thermally conductive. By also having a role as a filler, even if a resin is used for the bonding layer 17, the heat generated in the phosphor layer 2 by the excitation light from the solid light source 5 is reduced through the bonding layer 17 at a low temperature. It is possible to dissipate (heat dissipate) the heat dissipating substrate 6, increase the efficiency of heat dissipating from the phosphor layer 2, and increase the brightness.

  In order to solve the shortage of the red component in the illumination light (its spectrum), instead of the configuration of FIG. 3, as shown in FIG. 4, in the phosphor layer 22 (corresponding to the phosphor layer 2 of FIG. 3). For example, a red phosphor is included together with yellow and green phosphors, or, as shown in FIG. 5, for example, closer to the solid light source 5 than a phosphor layer 2 containing yellow and green phosphors. A configuration in which a phosphor layer 32 including a red phosphor is laminated is also conceivable. However, in the configuration of FIGS. 4 and 5, the red phosphor absorbs the fluorescence from the yellow and green phosphors again, so that the light utilization efficiency decreases. On the other hand, in the light source device 20 of FIG. 3, for example, the bonding layer 17 including the red phosphor is provided on the side farther from the solid light source 5 than the phosphor layer 2 including the yellow and green phosphors. Therefore, the red phosphor can be prevented from reabsorbing the fluorescence from the yellow and green phosphors, and the light utilization efficiency can be improved.

  In the configuration of FIG. 3, the bonding layer 17 includes phosphor particles (for example, red phosphor particles) that emit fluorescence having a wavelength longer than the emission wavelength of the first phosphor. In addition, as shown in FIG. 6, for example, a phosphor layer 42 that emits fluorescence having a wavelength longer than the emission wavelength of the first phosphor is disposed between the phosphor layer 2 and the joint portion 7 in the configuration of FIG. 2. Providing (stacking the phosphor layer 2 and the phosphor layer 42) is also conceivable. However, in this case, since the influence of the interface between the phosphor layer 2 and the phosphor layer 32 is produced, the light utilization efficiency is lowered as compared with the case of the phosphor layer 2 alone. This phenomenon appears remarkably when a phosphor layer not containing a resin is used for the phosphor layer 2 and the phosphor layer 32. On the other hand, in the light source device 20 of FIG. 3, the phosphor that emits light having a long wavelength is mixed in the bonding layer 17. The light use efficiency can be improved.

  Moreover, in the light source device of the present invention described above, the phosphor layer 2 and the bonding layer 17 may be fixed, but the phosphor layer 2 and the bonding layer 17 may be configured to be movable. For example, as shown in FIGS. 7A and 7B (FIG. 7A is a front view of the whole, FIG. 7B is a plan view of the phosphor layer 2), phosphor layer 2, bonding The layer 17 and the heat dissipation substrate 6 can also be configured as the reflection type fluorescent rotating body 1 that rotates around the rotation axis X (rotates by the motor 4 or the like). That is, the reflection type fluorescent rotating body 1 can be realized by connecting the phosphor layer 2 and the heat dissipation substrate 6 joined by the joining layer 17 to the motor 4 or the like. Here, the heat dissipation substrate 6 functions as a reflection surface for excitation light and fluorescence. In addition, the shape of the heat dissipation substrate 6 may be a disk shape or a quadrangle. In addition, in order to ensure the stability of rotation, it is possible to cut out a part of the disk or to have a shape with a weight on the contrary. In this way, by rotating the phosphor layer 2 and the bonding layer 17 with respect to the solid light source 5, it is possible to disperse the places where the excitation light hits and suppress the heat generation in the light irradiation section. By using this fluorescent rotator 1, heat generation of the fluorescent substance can be suppressed in the first place, so that even higher luminance can be achieved.

  Next, the above-described light source device of the present invention will be described in more detail.

  In the light source device of the present invention described above, the solid-state light source 5 can be a light emitting diode or a semiconductor laser having a light emission wavelength from the ultraviolet light to the visible light region.

More specifically, the solid-state light source 5 may be, for example, a light emitting diode or a semiconductor laser that emits blue light having a light emission wavelength of about 460 nm using a GaN-based material. In this case, the phosphor of the phosphor layer 2 is excited by blue light having a wavelength of about 440 nm to about 470 nm, and the yellow phosphor includes Y ₃ Al ₅ O ₁₂ : Ce ³⁺ (YAG), ( Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ^{2+ and the} like can be used, and for the green phosphor, Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ Y ₃ (Ga, Al) ₅ O ₁₂ : Ce ³⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , CaSc ₂ O ₄ : Eu ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ^2+, or the like can be used.

As the phosphor layer 2, a phosphor in which these phosphor powders are dispersed in glass, a glass phosphor in which a luminescent center ion is added to a glass matrix, a phosphor ceramic not including a binding member such as a resin, or the like is used. Can do. As a specific example of the phosphor powder dispersed in glass, the phosphor powder having the composition listed above is contained in a glass containing components such as P ₂ O ₃ , SiO ₂ , B ₂ O ₃ , and Al ₂ O _3. Are dispersed. Examples of glass phosphors in which a luminescent center ion is added to a glass matrix include Ca—Si—Al—O—N and Y—Si—Al—O—N systems in which Ce ³⁺ or Eu ²⁺ is added as an activator. Examples thereof include oxynitride glass phosphors. Examples of the phosphor ceramic include a sintered body having a phosphor composition having the composition listed above and substantially not including a resin component. Among these, it is desirable to use a phosphor ceramic having translucency. This is a phosphor ceramic that has translucency because there are almost no pores or impurities at grain boundaries that cause light scattering in the sintered body. Since pores and impurities can also prevent thermal diffusion, translucent ceramics exhibit high thermal conductivity. For this reason, when it uses as a fluorescent substance layer, it can take out from a fluorescent substance layer, and can utilize it, without losing excitation light and fluorescence by diffusion, Furthermore, the heat | fever which generate | occur | produced in the fluorescent substance layer can be dissipated efficiently. Even a sintered body that does not show translucency is desirable to have as few pores and impurities as possible. As an index for evaluating the remaining amount of pores, the value of specific gravity of the phosphor ceramic can be used, and it is desirable that the value is 95% or more with respect to the theoretical value by which the value is calculated.

Here, a method of manufacturing a phosphor ceramic having translucency will be described by taking as an example a Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor which is a blue-excited yellow light-emitting phosphor. The phosphor ceramic is manufactured through a starting material mixing step, a forming step, a firing step, and a processing step. As starting materials, yttrium oxide, cerium oxide, alumina, and the like, oxides of constituent elements of Y ₃ Al ₅ O ₁₂ : Ce ³⁺ phosphor, carbonates, nitrates, sulfates and the like that become oxides after firing are used. The particle size of the starting material is preferably a submicron size. These raw materials are weighed so as to have a stoichiometric ratio. At this time, for the purpose of improving the transmittance of the ceramic after firing, it is also possible to add a compound such as calcium or silicon. The weighed raw materials are sufficiently dispersed and mixed by a wet ball mill using water or an organic solvent. Next, the mixture is formed into a predetermined shape. As the molding method, a uniaxial pressing method, a cold isostatic pressing method, a slip casting method, an injection molding method, or the like can be used. The obtained molded body is fired at 1600 to 1800 ° C. Thus, translucent ^{_{Y 3 Al 5 O 12: Ce}} 3+ phosphor ceramic can be obtained.

  The phosphor ceramic produced as described above is polished to a thickness of several tens to several hundreds of μm using an automatic polishing apparatus and the like, and is further rounded by dicing or scribing using a diamond cutter or laser. Cut out to a board of any shape such as a square, fan or ring.

  Here, phosphor ceramics have a high refractive index with respect to air, and there are few things that cause scattering such as pores inside, and light is guided inside the ceramics. The light emission component emitted from the side surface increases, and the light emission component emitted in the front direction decreases. In order to solve this problem, the light emission component emitted in the front direction can be increased by providing an uneven light extraction structure by etching on the ceramic surface, mounting a lens, or providing a reflective layer on the side surface. Is also possible. Further, an AR coating (film having an antireflection function) made of an oxide multilayer film may be applied to the excitation light incident surface of the phosphor ceramic.

  Moreover, although a metal substrate, oxide ceramics, non-oxide ceramics, etc. can be used for the heat dissipation substrate 6, it is particularly desirable to use a metal substrate having high light reflection characteristics, heat transfer characteristics, and workability. As the metal, simple substances such as Al, Cu, Ti, Si, Ag, Au, Ni, Mo, W, Fe, Pd, and alloys containing them can be used. Further, the surface of the heat dissipation substrate 6 may be coated for the purpose of preventing reflection and corrosion. Further, the heat dissipation substrate 6 may be provided with a structure such as a fin in order to improve heat dissipation.

  For the resin of the bonding layer 17, for example, a high transparent resin such as a silicone resin can be used. That is, for the bonding layer 17, for example, a material obtained by dispersing and applying phosphor particles (for example, red phosphor particles) in a highly transparent resin such as a silicone resin can be used.

Here, phosphor particles (for example, red phosphor particles) included in the bonding layer 17 include CaAlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ^4+. The red phosphor particles contained in the bonding layer 17 have thermal conductivity and also serve as a thermal conductive filler. In order for the red phosphor particles contained in the bonding layer 17 to sufficiently fulfill the role of a heat conductive filler, the concentration of the red phosphor particles contained in the bonding layer 17 (concentration in the resin) is It is good that it is about 2 wt% to 50 wt%.

  As described above, in the present invention, the solid-state light source 5, the phosphor layer 2, and the bonding layer 17 are installed on the same side with respect to the heat dissipation substrate 6, thereby obtaining a reflective light source device. Of course, if necessary, an optical element such as a lens can be inserted between the solid light source 5 and the phosphor layer 2 and the bonding layer 17.

  Further, by combining the above-described various light source devices of the present invention with optical components such as a predetermined lens system, it is possible to provide an illumination device capable of increasing the brightness.

The present invention can be used for lighting in general.

DESCRIPTION OF SYMBOLS 1 Fluorescent rotating body 2 Fluorescent substance layer 4 Motor 5 Solid light source 6 Heat dissipation board 7 Joining part 17 Joining layer 10, 20 Light source device

Claims (5)

A solid-state light source that emits light of a predetermined wavelength in a wavelength region from ultraviolet light to visible light; and a light source that is excited by excitation light from the solid-state light source and is longer than the emission wavelength of the solid-state light source, rather than red A phosphor layer containing at least one first phosphor that emits short-wavelength fluorescence, and a surface of the phosphor layer opposite to a surface on which excitation light from the solid light source is incident. A surface of the phosphor layer, the solid light source and the phosphor layer being spatially separated from each other, and A light source device that takes out at least fluorescence from a surface on which excitation light from the solid light source is incident by a reflection method, and the bonding layer is excited when excited light from the solid light source is used. Emits fluorescence with a wavelength longer than the emission wavelength of 1 phosphor Light source device characterized in that it contains phosphor particles. The light source device according to claim 1, wherein a resin is used for the bonding layer. The light source device according to claim 1, wherein the phosphor layer is phosphor ceramic. 4. The light source device according to claim 1, wherein the light source device includes a fluorescent rotator including the phosphor layer, the bonding layer, and the heat dissipation substrate. Light source device. An illumination device, wherein the light source device according to any one of claims 1 to 4 is used.

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