JP2015103539A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device capable of obtaining the mixed color light of a desired color tone.SOLUTION: A light source device 100 includes: a light source 10 for emitting a first light A; and a fluorescent member 20 for emitting a second light using the first light A as excitation light. One main surface of the fluorescent member 20 is irradiated with the first light A, and the mixed color light B of the first light A and the second light is emitted from one main surface of the fluorescent member 20. Then, on one main surface of the fluorescent member 20, a translucent layer 30 is provided whose refractive index is higher than that of the fluorescent member 20, and the interface between the fluorescent member 20 and the translucent layer 30 has a rough surface.

Description

  The present invention relates to a light source device.

  An illuminating device using a semiconductor laser element that emits light in a blue wavelength region and a phosphor that emits light in a red wavelength region from a green wavelength region has been proposed (Patent Document 1). Patent Document 1 describes that by providing a light mixing layer having an uneven surface on the phosphor, semiconductor laser light and fluorescence are uniformly mixed in any orientation, and the uniformity of illumination light is improved. ing.

JP 2012-54058 A

  However, even if it is configured as in Patent Document 1, it is difficult to obtain mixed color light having a desired color tone sufficiently including laser light, and there is room for further improvement.

  Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a light source device that can obtain mixed color light having a desired color tone.

  A light source device according to an aspect includes a light source that emits first light and a fluorescent member that emits second light using the first light as excitation light. The first light is irradiated on one main surface of the fluorescent member, and the mixed light of the first light and the second light is emitted from the one main surface of the fluorescent member. A light transmitting layer having a refractive index higher than that of the fluorescent member is provided on one main surface of the fluorescent member, and the interface between the fluorescent member and the light transmitting layer is rough.

  A light source device according to an aspect includes a light source that emits first light and a fluorescent member that emits second light using the first light as excitation light. The first light is irradiated on one main surface of the fluorescent member, and the mixed light of the first light and the second light is emitted from the one main surface of the fluorescent member. In addition, a first light-transmitting layer and a second light-transmitting layer having a refractive index higher than that of the first light-transmitting layer are provided on one main surface of the fluorescent member in order from the fluorescent member side. The interface between the first translucent layer and the second translucent layer is uneven.

  ADVANTAGE OF THE INVENTION According to this invention, the light source device which can obtain mixed color light of a desired color tone can be provided.

1 is a cross-sectional view illustrating a schematic configuration of a light source device according to a first embodiment. It is the figure which expanded the interface of the fluorescent member and translucent layer in the light source device shown in FIG. It is a sectional view showing a schematic structure of a light source device according to a second embodiment. It is a sectional view showing a modification of a schematic structure of a light source device according to a second embodiment. It is a sectional view showing a modification of a schematic structure of a light source device according to a second embodiment. It is a chromaticity diagram showing the color tone of light observed in Examples 1 and 2 and Comparative Examples 1 and 2.

Hereinafter, the light emitting device according to the present embodiment will be described with reference to the drawings. However, the form shown below is the illustration for materializing the technical idea of this invention, Comprising: This invention is not limited to the following. In addition, the positions, sizes, and the like of members shown in each drawing may be exaggerated for clarity of explanation. About the same name and code | symbol, the same or the same member is shown in principle, and the duplicate description is abbreviate | omitted.
[First Embodiment]

  The light source device 100 according to the first embodiment will be described with reference to FIGS. FIG. 1 is a cross-sectional view of the light source device 100. FIG. 2 is an enlarged view of the interface between the fluorescent member 20 and the translucent layer 30 in the light source device 100 shown in FIG. 1, and schematically shows the path of the incident first light.

  As shown in FIG. 1, the light source device 100 includes a light source 10 that emits first light, and a fluorescent member 20 that emits second light using the first light as excitation light. Here, the first light (“A” shown in FIG. 1) is applied to one main surface of the fluorescent member 20, and the mixed light of the first light and the second light (“B” shown in FIG. 1) is fluorescent member 20. It is taken out from one main surface side. A light transmitting layer 30 having a refractive index higher than that of the fluorescent member 20 is provided on one main surface of the fluorescent member 20, and the interface between the fluorescent member 20 and the light transmitting layer 30 is a rough surface.

  Accordingly, it is possible to obtain mixed color light having a desired color tone with little color unevenness and a sufficiently high ratio of the first light. This point will be described below.

  Generally, in a light source device configured such that the side irradiated with the first light and the side from which the mixed color light including the first light and the second light is extracted are the same, the first light reciprocates inside the fluorescent member. (In other words, the path through which the first light passes through the inside of the phosphor member becomes long), so the second light tends to be dominant in the finally obtained mixed color light. As a result, when the mixed color light is observed on the one main surface side of the fluorescent member, the second light is more than the first light as a whole, and the light of the second light tends to be strong.

  In contrast, in the present embodiment, as shown in FIGS. 1 and 2, a fluorescent member (the fluorescent member 20 is made of two or more types of materials) on the first main surface 21 that is one main surface of the fluorescent member 20. In this case, a light-transmitting layer 30 having a refractive index higher than that of the material having the highest refractive index is provided, and the interface between the two is a rough surface. Accordingly, the first light incident on the fluorescent member 20 from the transparent film 30 at the interface between the relatively high refractive index region (the transparent layer 30) and the relatively low refractive index region (the fluorescent member 20). Therefore, it is possible to obtain mixed color light having a desired color tone with a sufficiently large color component of the first light. In addition, since the interface between the fluorescent member 20 and the translucent layer 30 is a rough surface, the direction in which the first light is totally reflected can be dispersed, so that uneven distribution of the first light can also be reduced.

  Hereinafter, main members constituting the light source device 100 will be described.

(Light source 10)
The light source 10 emits first light. The first light is for exciting the fluorescent member 20 and constitutes a part of the mixed color light. As 1st light, it can be set as the blue light which exists in the range whose peak wavelength is 420-480 nm, for example.

  As the light source 10, for example, an LD (laser diode) or an LED (light emitting diode) can be used. In particular, by using an LD as the light source 10, the first light can be made into a laser beam having a strong directivity of light, so that the fluorescent member 20 can be reduced in size, and as a result, the entire light source device can be reduced in size. Become. Therefore, the light source 10 is preferably an LD.

  The first light emitted from the light source 10 travels in the order of the light transmitting layer 30 and the fluorescent member 20 from the atmosphere. More specifically, a part of the first light is reflected at the interface between the light transmitting layer 30 and the fluorescent member 20, but the other part is taken into the fluorescent member 20. A part of the first light taken into the fluorescent member 20 excites the fluorescent member 20 to become the second light, and the other part is taken out as it is as the first light.

  In the present embodiment, as shown in FIG. 1, the light source 10 is arranged on the first main surface 21 side of the fluorescent member 20, and the first light from the light source 10 is directly (in a straight line) the first of the fluorescent member 20. The main surface 21 is irradiated. However, the traveling direction of the first light is changed by disposing the light source 10 on the first main surface 21 side or the second main surface 22 side of the fluorescent member 20 and reflecting the first light from the light source 10 with a mirror or the like. Thereafter, the first main surface 21 of the fluorescent member 20 may be irradiated with the first light. Alternatively, after the light source 10 is disposed on the first main surface 21 side or the second main surface 22 side of the phosphor member 20 and the traveling direction of the first light from the light source 10 is controlled using a fiber or the like, the light source 10 The first main surface 21 of the fluorescent member 20 may be irradiated with the first light from.

  In the present embodiment, one light source 10 is used, but a plurality of light sources 10 can also be used. When there are a plurality of light sources 10, the light sources may emit light having the same peak wavelength, or may emit light having a peak wavelength shifted by several nm for the purpose of reducing speckle noise, for example.

(Fluorescent member 20)
The fluorescent member 20 is a member that is excited by the first light from the light source 10 and emits second light that is light having a longer wavelength than the first light.

  As the thickness of the fluorescent member 20 increases, the heat dissipation becomes worse. On the other hand, if the film thickness is reduced, handling becomes difficult and the fluorescent member 20 may be broken. For this reason, the film thickness of the fluorescent member 20 is preferably 50 μm to 200 μm, and more preferably 100 μm to 150 μm.

  As shown in FIG.1 and FIG.2, the interface of the fluorescent member 20 and the translucent layer 30 is a rough surface. Thereby, as shown in FIG. 2, even if the first light from the light source 10 is incident in one direction, the incident angle from the translucent layer 30 to the fluorescent member 20 varies when viewed microscopically. The component having a small incident angle with respect to the rough surface of the first main surface 21 in the first light proceeds to the fluorescent member 20 as it is, but the incident angle with respect to the rough surface of the first main surface 21 in the first light. The component having a large value is totally reflected because the refractive index of the translucent layer 30 is larger than the refractive index of the fluorescent member 20. Accordingly, the color of the first light can be increased by the amount of total reflection in the mixed color light B. In addition, since the first light scattered at the interface between the translucent layer 30 and the fluorescent member 20 is emitted in a wide range on the first main surface 21 side of the fluorescent member 20, the distribution of the first light in the observed mixed color light. The unevenness of the color mixture light can be reduced. In the case where the first light is laser light, if the directivity of the laser light cannot be suppressed, uneven color is noticeable in the observed mixed color light. Since the directivity of the laser can be suppressed by scattering at the interface with the optical layer 30, color unevenness can be reduced. In addition, in order to acquire such an effect, although it is preferable that the whole area of the interface of the fluorescent member 20 and the translucent layer 30 is a rough surface, it cannot be overemphasized that one area | region may be made into a rough surface.

  As shown in FIGS. 1 and 2, a plurality of fine irregularities are formed at the interface between the fluorescent member 20 and the translucent layer 30, but it is preferable that the size and formation location are irregular. Thereby, since the 1st light totally reflected by the interface of the translucent layer 30 and the fluorescent member 20 can be discharge | released so that it may become uniform over a wide range, the color nonuniformity of mixed color light can be reduced more.

  Moreover, the surface area of the 1st main surface 21 increases because the 1st main surface 21 of the fluorescent member 20 is a rough surface, and adhesiveness with the translucent layer 30 improves.

  In order to make the interface between the fluorescent member 20 and the translucent layer 30 rough, for example, the first main surface 21 of the fluorescent member 20 is roughened by grinding, wet etching or dry etching, and then the rough surface is sputtered. The light transmitting layer 30 may be formed by CVD or the like. In particular, grinding is preferable from the viewpoint of manufacturing because the surface of the fluorescent member 20 can be controlled and the surface thereof can be roughened at the same time.

The fluorescent member 20 may be composed of a phosphor and a holder for retaining the phosphor, or may be composed of only the phosphor. When the fluorescent member 20 is composed of a phosphor and a holder, the holder is preferably an inorganic material. Thereby, compared with the case where the holding body is an organic material such as a resin, the inorganic material is less likely to be discolored even when the first light from the light source 10 is irradiated for a long time, thereby suppressing a decrease in output as the light source device. be able to. Examples of the inorganic material include Al ₂ O _{3 and} Y ₂ O ₃ . On the other hand, when the fluorescent member 20 is composed of only the fluorescent material, the uneven distribution of the fluorescent material is reduced as compared with the case where the fluorescent member 20 includes a holding body. It is possible to suppress a difference in the appearance of the light emitted from each fluorescent member 20.

  Examples of the method for forming the fluorescent member 20 include SPS (Spark Plasma Sintering), HIP (Hot Isostatic Pressing), and CIP (Cold Isostatic Pressing). Or the like can be used. Moreover, as a kind of fluorescent substance, a YAG type fluorescent substance, a LAG type fluorescent substance, a TAG type fluorescent substance, or a mixture thereof can be used, for example.

(Translucent layer 30)
As shown in FIG. 1, a light transmitting layer 30 having a higher refractive index than that of the fluorescent member 20 is provided on the first main surface 21 of the fluorescent member 20. Part of the first light can be totally reflected at the interface between the fluorescent member 20 and the translucent layer 30 and extracted to the outside.

  The refractive index of the translucent layer 30 should be 0.3 or more larger than the refractive index of the fluorescent member 20 (or the material having the highest refractive index in the case where the fluorescent member 20 is made of two or more materials). Is preferred. By increasing the refractive index difference between the fluorescent member 20 and the translucent layer 30, the proportion of the first light that is totally reflected at the interface between the two can be increased. As a material of the light transmitting layer 30, for example, when YAG (refractive index of 1.8 at a wavelength of 445 nm) is used as a phosphor constituting the fluorescent member 20, zirconium oxide (refractive index of 2.1 at a wavelength of 445 nm) or niobium oxide is used. (With a wavelength of 445 nm and a refractive index of 2.4 to 2.5).

  The surface of the light transmitting layer 30 on which the first light is irradiated may be a flat surface, but may be a rough surface as shown in FIG. Thereby, when the first light is incident on the inside of the light-transmitting layer 30 or when the first light and the second light are emitted, each light can be scattered, so that the mixed color light with less color unevenness is obtained. be able to. In addition, instead of making the surface on the side irradiated with the first light in the light-transmitting layer 30 or the surface on the side irradiated with the first light in the light-transmitting layer 30 as a rough surface, A scattering agent can also be added to the inside of the light transmitting layer 30.

The film thickness of the translucent layer 30 can be set to an arbitrary value. When the light-transmitting film 30 has a film thickness equal to or less than λ / n ₁ (λ: wavelength of the first light from the light source, n ₁ : effective refractive index of the light-transmitting layer 30), the light is transmitted to the surrounding medium (amplitude). In the present embodiment, the effective refractive index n ₁ of the translucent film 30 is reduced because it leaks into the air and is affected by the refractive index of the medium. Thereby, the critical angle at which the first light is totally reflected at the interface between the light transmissive film 30 and the fluorescent member 20 is changed, and the ratio of the first light to be totally reflected can be changed. By controlling the film thickness, the color tone of the mixed color light observed on the first main surface 21 side of the fluorescent member 20 can be adjusted. Here, for example, blue light having a peak wavelength of 445 nm is used as the first light, niobium oxide is used as the light-transmitting layer 30, and the reflectivity at the interface between the light-transmitting layer 30 and the fluorescent member 20 is oxidized by the film thickness of niobium oxide. In order to control by the film thickness of niobium, the film thickness of niobium oxide is preferably 5 nm to 50 nm.

(Other parts)
In this embodiment, as shown in FIGS. 1 and 3, the surface of the fluorescent member 20 that is opposite to the first main surface 21 irradiated with the first light (that is, the second main surface 22 of the fluorescent member 20). The reflection member 40 can also be provided on the side. Although the reflection member 40 is not an essential component in the light source device 100, the first light and the second light can be reflected to the first main surface 21 side by the reflection member 40, thereby improving the output as the light source device. Can be made.

The reflecting member 40 is preferably made of a material having high reflectivity with respect to the first light and the second light. For example, a metal such as Ag, Al, Au, or Rh, or SiO ₂ , Al ₂ O ₃ , AlN, A so-called DBR composed of a dielectric multilayer film in which dielectrics such as ZrO ₂ , TiO ₂ , and Nb ₂ O ₅ are superposed is mentioned. Of course, the reflecting member 40 may be a combination of the above-described metals and dielectric films.

A condensing lens may be provided on a path along which the first light travels from the light source 10 toward the translucent layer 30. Thereby, it becomes easy to control the irradiation range of the first light. Further, in the case where the first light is laser light, if the laser light is emitted to the outside with a high light density, there is a risk of adversely affecting the human body of the observer. However, when the condenser lens is used, the light density of the first light increases as it goes to the focal point, but once it passes the focal point, it decreases as it moves away from the focal point. Even if the first light reaches the observer, The adverse effects on the human body can be reduced.
[Second Embodiment]

  A light source device 200 according to the second embodiment will be described with reference to FIGS. FIG. 3 is a cross-sectional view of the light source device 200. 4 and 5 are cross-sectional views of modifications of the light source device 200. FIG. Since the light source device 200 has substantially the same configuration as that of the light source device 100 except that the light transmissive layer includes the first light transmissive layer 31 and the second light transmissive layer 32, the overlapping configuration and effects are omitted. There is.

  As shown in FIG. 3, the first main surface 21 of the fluorescent member 20 includes a first light transmitting layer 31 and a second light transmitting layer 32 having a refractive index higher than that of the first light transmitting layer 31. It is provided in order from the side. Furthermore, the interface between the first light transmissive layer 31 and the second light transmissive layer 32 is a rough surface. With the above configuration, the first light irradiated on the first main surface 21 of the fluorescent member 20 is a region having a relatively low refractive index (first light transmitting layer 32) from a region having a relatively high refractive index (second light transmitting layer 32). Since the light travels to the light layer 31), the first light incident on the first light transmissive layer 31 from the second light transmissive layer 32 is totally reflected by the same principle as in the first embodiment to Since it can be extracted to the first main surface 21 side, it is possible to obtain mixed color light ("B" shown in FIG. 3) having a desired color tone with a sufficiently large color component of the first light. Furthermore, since the interface between the first light-transmitting layer 31 and the second light-transmitting layer 32 is a rough surface, the direction in which the first light is totally reflected can be expanded over a wide range, and the reflection direction of the first light is biased. It is also possible to reduce uneven distribution.

  The second light transmissive layer 32 preferably has a refractive index higher than that of the first light transmissive layer 31 by 0.3 or more. By increasing the difference in refractive index between the first light-transmitting layer 31 and the second light-transmitting layer 32, the proportion of the first light that is totally reflected can be increased. The first light transmissive layer 31 and the second light transmissive layer 32 are preferably made of a material that absorbs less light. As a combination of the first light transmitting layer 31 and the second light transmitting layer 32 satisfying these conditions, for example, silicon oxide (refractive index 1.46 at a wavelength of 445 nm) / niobium oxide (refractive index 2.43 at a wavelength of 445 nm), Alternatively, silicon oxide / zirconium oxide (with a wavelength of 445 nm and a refractive index of 2.21) can be used.

  In the present embodiment, as shown in FIG. 3, the interface between the first light transmissive layer 31 and the second light transmissive layer 32 is a rough surface. To design in this way, for example, the surface of the first light transmitting layer 31 on the second light transmitting layer 32 side is roughened by grinding or the like, and the rough surface is formed by sputtering or CVD or the like with the second light transmitting layer 32. What is necessary is just to coat.

  The surface of the second light transmissive layer 32 on which the first light is irradiated can be a flat surface, but is preferably a rough surface as shown in FIG. Thereby, when the first light is incident on the inside of the second light transmitting layer 32 or when the first light and the second light are emitted, the respective lights can be scattered, so that the mixed color light with less color unevenness can be obtained. can do.

  Although the 1st main surface 21 of the fluorescent member 20 can also be made into a flat surface, it is preferable to make it rough as shown in FIG. Accordingly, when the first light is incident on the inside of the fluorescent member 20 or when the first light and the second light are emitted, the respective lights can be scattered, so that the mixed color light with less color unevenness can be obtained. it can. In addition, if the 1st main surface 21 of the fluorescent member 20 is a rough surface, the surface area will increase and adhesiveness with the 1st translucent layer 31 will improve.

As a modification of the light source device 200 in the present embodiment, the first light transmissive layer 31 can be an air layer. If the first light transmitting layer 31 is an air layer having a refractive index of approximately 1, a large difference in refractive index between the second light transmitting layer 32 and the first light transmitting layer 31 (air layer) can be secured. The ratio at which the first light is totally reflected can be increased. As an example of a configuration satisfying such conditions, the configurations shown in FIGS. 4 and 5 can be cited. In FIG. 4, the first main surface 21 of the fluorescent member 20 is a flat surface, and the sheet-like second light-transmitting layer in which the surface on the fluorescent member 20 side is a rough surface on the upper surface of the first main surface 21 of the fluorescent member 20. 32 is provided. FIG. 5 shows a configuration in which the first main surface 21 of the fluorescent member 20 and the surface of the second light transmissive layer 32 on the fluorescent member 20 side are both rough. In addition, the second light-transmitting layer is made wider than the fluorescent member, and a member (reflector plate) on which the second light-transmitting layer and the fluorescent member are placed in a region of the second light-transmitting layer that protrudes from the fluorescent member. Etc.) and an air layer (first light-transmitting layer) can be provided between the fluorescent member and the second light-transmitting layer.
Example 1

  Example 1 corresponds to Embodiment 1 shown in FIG.

First, a YAG phosphor having an average particle diameter of about 10 μm [(Y _0.97 Gd _0.03 ) _2.85 Ce _0.15 ] made of Al ₅ O ₁₂ and aluminum oxide (Al ₂ O ₃ ). The holding body was mixed and sintered using the SPS sintering method, thereby producing a massive fluorescent member.

  Next, the massive fluorescent member was sliced into a plate shape having the first main surface 21 and the second main surface 22 with a wire saw. At this time, the thickness of the fluorescent member obtained by slicing was 300 μm. Thereafter, both the first main surface 21 and the second main surface 22 are ground using diamond abrasive grains of # 200, and only the second main surface 22 is polished and subjected to CMP treatment, so that the film thickness of the fluorescent member 20 is increased. To 150 μm. By this step, a rough first main surface 21 and a mirror second main surface were obtained. In addition, it was 4.65 micrometers when the surface roughness of the 1st main surface 21 which is a rough surface was measured using the Keyence laser microscope. Further, regarding the unevenness of the rough surface, the height difference was 14 μm at the portion where the height difference was large, and the average height difference was 4.8 μm.

  Next, the fluorescent member was separated into 3 mm × 3 mm sizes, and the fluorescent member 20 shown in FIG. 1 was produced.

Next, as shown in FIG. 1, a light-transmitting layer 30 made of niobium oxide (Nb ₂ O ₅ ) having a film thickness of 20 nm was formed on the first main surface 21 of the fluorescent member 20 by sputtering. At this time, since the light transmissive layer 30 is formed on the first main surface 21 which is a rough surface of the fluorescent member 20, the surface of the light transmissive layer 30 on which the first light is irradiated is also a rough surface. The surface roughness of the surface of the light transmitting layer 30 on which the first light is irradiated was 4.65 μm.

  Next, as shown in FIG. 1, a reflective member 40 made of an Ag film having a thickness of 300 nm was formed on the second main surface 22 of the fluorescent member 20 by sputtering.

Next, on the first main surface 21 side of the fluorescent member 20, a blue LD element having a peak wavelength of 445 nm is disposed as the light source 10, and the first light from the light source 10 (that is, blue light) is fluorescent at a predetermined angle. Irradiation toward the first main surface 21 of the member 20 was performed. Then, the mixed light of the first light and the second light from the fluorescent member 20 was evaluated on the first main surface 21 side of the fluorescent member 20.
(Example 2)

Example 2 corresponds to Embodiment 2 shown in FIG. 3, and is the same as Example 1 except that the light-transmitting layer 30 of Example 1 is changed to a first light-transmitting layer 31 and a second light-transmitting layer. It is. That is, the fluorescent member 20 was produced under the same conditions as in Example 1. Then, a first light-transmitting layer 31 made of silicon oxide (SiO ₂ ) having a film thickness of 76 nm is formed on the upper surface of the first main surface 21 of the fluorescent member 20, and niobium oxide having a film thickness of 1 μm is formed on the upper surface by sputtering. A second light transmissive layer 32 made of Nb ₂ O ₅ was formed. At this time, the 1st main surface 21 of the fluorescent member 20 was a rough surface, and the surface roughness was 4.65 micrometers. Moreover, since the 1st light transmission layer 31 and the 2nd light transmission layer 32 are formed as a thin film on the upper surface of the 1st main surface 21 of the fluorescent member 20 which is a rough surface, the 2nd light transmission in the 1st light transmission layer 31 is carried out. The surface roughness of the surface on the layer 32 side and the surface of the second light transmissive layer 32 on the side irradiated with the first light has a value equivalent to the surface roughness of the first main surface 21 of the fluorescent member 20 that is the base, Both were 4.65 μm.

Next, as in Example 1, after the fluorescent member 20 is placed on the reflecting member 40, the first main surface 21 side of the fluorescent member 20 is irradiated with the first light, and the first main surface of the fluorescent member 20 is irradiated. Evaluation of mixed light of the first light and the second light from the fluorescent member 20 was performed on the surface 21 side.
(Comparative Example 1)

In Comparative Example 1, the fluorescent member 20 is the same as that in Example 1, but the same evaluation as in Example 1 was performed as a configuration in which the light-transmitting layer 30 was not provided.
(Comparative Example 2)

In Comparative Example 2, the fluorescent member 20 has the same configuration as that of Example 1, and the light-transmitting layer 30 is made of silicon oxide (having a wavelength of 445 nm and a refractive index of 1.46) as a material having a refractive index smaller than that of the fluorescent member 20. The film thickness was 76 nm and the same evaluation as in Example 1 was performed.
(Evaluation)

  FIG. 6 is a chromaticity diagram in which the color tones of mixed color light observed in Examples 1 and 2 and Comparative Examples 1 and 2 are plotted. A circular plot indicates the result of Example 1, and a triangular plot indicates the example. 2 shows a result, a rhombus plot shows the result of Comparative Example 1, and a square plot shows the result of Comparative Example 2. As can be understood from FIG. 6, in Comparative Example 1, white light that is off the black body locus line shown by the dotted line in FIG. 6 is observed, whereas in Example 1 and Example 2, White light located near the line of the black body locus was observed, and white light with a desired color tone was obtained. In Comparative Example 2, white light greatly deviating from the black body locus line was observed, and white light having a desired color tone could not be obtained.

DESCRIPTION OF SYMBOLS 100, 200 ... Light source device 10 ... Light source 20 ... Fluorescent member 21 ... 1st main surface 22 ... 2nd main surface 30 ... Translucent layer 31 ... 1st translucent Layer 32 ... second light transmissive layer 40 ... reflecting member

Claims (9)

A light source that emits first light; and a fluorescent member that emits second light using the first light as excitation light. The main surface of the fluorescent member is irradiated with the first light, A light source device that emits mixed color light of first light and second light from a surface,
A light-transmitting layer having a higher refractive index than the fluorescent member is provided on one main surface of the fluorescent member,
The light source device, wherein an interface between the fluorescent member and the translucent layer is a rough surface. A light source that emits first light; and a fluorescent member that emits second light using the first light as excitation light. The main surface of the fluorescent member is irradiated with the first light, A light source device that emits mixed color light of first light and second light from a surface,
A first light-transmitting layer and a second light-transmitting layer having a refractive index higher than that of the first light-transmitting layer are provided on one main surface of the fluorescent member in this order from the fluorescent member side.
The light source device, wherein an interface between the first light-transmitting layer and the second light-transmitting layer is a rough surface.   The light source device according to claim 1, wherein a surface of the translucent layer on which the first light is irradiated is a rough surface.   The light source device according to claim 2, wherein one main surface of the fluorescent member is a rough surface.   5. The light source device according to claim 2, wherein a surface of the second light transmissive layer on which the first light is irradiated is a rough surface.   The light source device according to claim 2, wherein the first light transmissive layer is an air layer. The fluorescent member has a phosphor and a holding body for holding the phosphor,
The light source device according to claim 1, wherein the holding body is an inorganic material.   The light source device according to claim 1, wherein the fluorescent member is composed of only a fluorescent material. The light source is a semiconductor laser that emits blue light as the first light,
The light source device according to claim 1, wherein the fluorescent member includes a material that is excited by the first light and emits yellow light as the second light.

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