JP2019095601A - Phosphor member and light source device - Google Patents

Abstract

To efficiently output fluorescent light from a phosphor film.SOLUTION: A phosphor member (200) includes: a substrate (210); and a phosphor layer (220) disposed on the substrate. The phosphor layer includes: a phosphor film (222) including phosphor particles for converting the excitation light into the fluorescent light; a first light reflection layer (223) for reflecting, toward the phosphor film, the excitation light and fluorescent light emitted from a substrate side-surface in the phosphor film; and second light reflection layers (224 and 225) that are disposed to cover the side surface of the phosphor film, and reflect, toward the phosphor film, the excitation light or fluorescent light emitted from the side-surface of the phosphor film through the phosphor film.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a phosphor member and a light source device using the same.

  In the relevant technical field, a light source device has been proposed which converts excitation light emitted from a solid state light source into visible light by a phosphor and emits light efficiently. In Patent Document 1, excitation light (blue laser light) emitted from a light source is irradiated to a disk (phosphor wheel) on which a phosphor is formed to emit plural fluorescent lights (red light and green light). A configuration for use as illumination light is disclosed.

JP, 2011-13313, A

  When phosphor particles contained in the phosphor film convert excitation light into fluorescence light, the fluorescence light is emitted in all directions of the phosphor film. On the other hand, since the surface from which the fluorescent light is extracted from the phosphor film is limited to the emitting surface of the fluorescent light, the fluorescent light emitted in the direction different from the emitting surface is not output from the emitting surface. This leads to the loss of fluorescent light. Therefore, a device for preventing the loss of fluorescent light and further improving the output of fluorescent light is required.

  The object of the present invention is made in view of the above-mentioned situation, and aims at outputting fluorescent light more efficiently from a phosphor film.

  In order to solve the above-mentioned subject, the present invention comprises composition indicated in a claim. One example thereof is a phosphor member including a substrate and a phosphor layer disposed on the substrate, wherein the phosphor layer converts phosphor particles for converting excitation light into fluorescence light. And a first light reflecting layer disposed in contact with the side surface of the substrate in the phosphor film and reflecting the excitation light and the fluorescent light emitted from the side surface of the substrate toward the phosphor film. And a second light reflecting layer disposed so as to surround the side surface of the phosphor film and reflecting the excitation light or the fluorescent light emitted from the side surface toward the phosphor film. It features.

  According to the present invention, the luminous efficiency of the phosphor film can be improved. The objects, configurations and effects of the present invention other than the above will be clarified in the following embodiments.

A perspective view for explaining the internal configuration of the projector Schematic diagram of light source device Cross-sectional view showing an example of a phosphor member Cross section showing another example of phosphor member Diagram showing the effect of the light reflection layer on the output of fluorescent light Diagram showing phosphor film size against laser spot diameter Luminometer photogram when the phosphor film is irradiated with excitation light

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

  Hereinafter, a phosphor member according to the present embodiment and a projector mounted with a light source device using the same will be described with reference to FIG. FIG. 1 is a perspective view for explaining the internal configuration of the projector.

  As shown in FIG. 1, in the projector 1, the power is supplied from the power supply unit 2 disposed on the front side of the left side of the box-like lower housing 5 in FIG. Light is emitted from the light source unit 3 and is incident on an optical unit 4 disposed at the rear on the back of the figure. The cooling fan 10 is disposed adjacent to the light source unit 3 and disposed between the light source unit 3 and the power supply unit 2.

  The drive circuit for driving the cooling fan 10 may be provided in the power supply unit 2 or may be provided in an empty space in the lower housing 5.

  The light incident on the optical unit 4, that is, the light emitted from the light source unit 3 is finally enlarged by the projection lens emission unit 9 b of the projection lens 9 and projected on a screen (not shown).

  A ventilation duct inlet port 71 a is provided on the side surface of the lower housing 5. The ventilation duct 71 is installed so that cooling air other than the optical system does not enter the cooling air of the optical components, and outside air is taken in from the ventilation duct inlet 71a using a panel cooling fan installed inside.

  The cooling air taken in from the ventilation duct inlet 71a is rectified by the ventilation duct 71, passes around the respective components contained in the lower housing 5, and cools them.

  FIG. 2 is a schematic configuration diagram of a light source device that constitutes the light source unit 3 of FIG. The light source device 100 has an excitation light source 105, a mirror 104, and a phosphor member 200 as main components.

  The phosphor member 200 mainly includes a substrate 210 and a phosphor layer 220 laminated on a surface (surface) on the light emission direction side of the substrate 210.

  The excitation light source 105 includes one or more solid light emitting elements such as laser light emitting elements, and emits, for example, blue laser light as excitation light.

  The excitation light 110 (shown by a solid line) emitted from the excitation light source 105 becomes substantially parallel light by the collimator lens 106, passes through the wavelength plate 107, and is incident on the mirror 104.

  The mirror 104 reflects a wavelength range of excitation light (blue) and has a dichroic coating having a characteristic of transmitting the wavelength range (yellow) of fluorescent light, and the reflection wavelength of blue light is different depending on the polarization state. It is designed.

  A part of the excitation light 110 incident from the excitation light source 105 is reflected by the mirror 104, condensed by the condensing lens 103 a, and is incident on the substrate 210. Further, part of the excitation light 110 passes through the mirror 104 and is condensed by the condensing lens 103 b and enters the diffusion plate 108.

  The ratio of the reflected light to the transmitted light at the mirror 104 at this time can be adjusted by the angle of the diffusion plate 108.

  When excitation light is incident on the phosphor layer 220, fluorescent light is generated. The fluorescent light becomes substantially parallel light by the condenser lens 103 a and is incident on the mirror 104. The incident fluorescent light passes through the mirror 104 due to the spectral characteristics of the mirror 104.

  Further, the excitation light 110 incident on the diffusion plate 108 is diffused and reflected by the diffusion plate 108, then a part of the light is reflected by the mirror 104, mixed with the above-described fluorescent light, and emitted as white light 111.

  At this time, the laser beam mixed with the fluorescent light has the same distribution as the fluorescent light generated from the substrate 210 by being diffused and reflected by the diffusion plate 108, and the color mixing unevenness can be suppressed.

  Further, as shown in FIG. 2, by disposing the laser so that the excitation light passes around the condensing lens 103 a that condenses the excitation light to be incident on the phosphor layer 220, the incident light to the phosphor layer 220 It is possible to make the corner larger. With this configuration, by efficiently generating fluorescent light from the phosphor layer 220, power saving of the excitation light source 105 and downsizing of the device can be realized.

  The configuration of the phosphor member will be described with reference to FIGS. 3 and 4. FIG. 3 is a cross-sectional view showing an example of a phosphor member. FIG. 4 is a cross-sectional view showing another example of the phosphor member.

  The phosphor member 200 in FIG. 3 is configured by laminating the phosphor layer 220 on the excitation light incident surface side (surface) 210 a of the substrate 210 via the adhesive layer 230.

(Substrate 210)
The phosphor member 200 uses a phosphor wheel as the substrate 210. The phosphor wheel includes a disk-shaped phosphor layer holding portion 211 and a rotation center shaft 212 connected to a motor rotating about the phosphor layer holding portion 211.

  Then, by rotating the phosphor layer holding part 211 around the rotation center axis 212, the excitation light is locally incident on the phosphor layer 220, and it is suppressed that the temperature is locally high.

  The phosphor layer 220 is formed in a ring shape centering on the central axis of rotation 212, and is fixed to the substrate 210 via the adhesive layer 230.

  The phosphor layer 220 includes a phosphor film 222 and a first light reflection layer 223 on the side surface (back surface) of the phosphor film 222. Furthermore, the phosphor film 222 is configured to include an anti-reflection layer 221 integrally formed on the surface (surface) opposite to the side surface of the substrate by PVD.

  The phosphor layer 220 further includes an inner light reflecting layer 224 covering the radially inner side of the phosphor layer 220 and an outer light reflecting layer 225 covering the radially outer side. That is, the side surfaces of the reflection preventing layer 221 and the phosphor film 222 of the phosphor layer 220 are formed so as to be surrounded by the inner light reflecting layer 224 and the outer light reflecting layer 225. Therefore, the inner light reflection layer 224 and the outer light reflection layer 225 correspond to a second light reflection layer surrounding the side surface of the phosphor film 222.

  The above “PVD” includes sputtering, vapor deposition, and the like, and is not limited to one vapor deposition. In addition, the deposition order by PVD is not limited, either. That is, either the antireflection layer 221 or the first light reflecting layer 223 may be performed first on the phosphor film 222.

(First light reflecting layer 223, inner light reflecting layer 224, outer light reflecting layer 225)
The first light reflection layer 223, the inner light reflection layer 224, and the outer light reflection layer 225 have a reflectance of 95% or more for excitation light and fluorescence light, respectively, and the higher the reflectance, the better. It is not limited. For example, an Ag film is used as the first light reflection layer 223, the inner light reflection layer 224, and the outer light reflection layer 225, and an Ag film is directly formed on the back surface of the phosphor film 222 and the side surfaces of the phosphor film 222 and the antireflective layer 221. You may

(Phosphor film 222)
The phosphor film 222 is a functional film that converts excitation light incident into the phosphor film 222 into fluorescence light and emits the fluorescence light to the outside of the phosphor film 222, and the material is not particularly limited. For example, the phosphor film 222 may be composed of a sintered phase containing phosphor particles and aluminum oxide (alumina) and an air phase. The phosphor particles are YAG or LAG, and the average particle diameter of alumina contained in the sintered phase is 1 μm to 50 μm, and the air phase occupied in the phosphor film is 5 vol. It is also possible to use a phosphor film having a thickness of 50 μm or more and 200 μm or less.

(Antireflection layer 221)
When the excitation light is incident on the surface of the phosphor film 222, the difference in refractive index between the surface of the phosphor film 222 and the air layer is large, and the reflectance of the excitation light on the surface of the phosphor film 222 is large. Light can not be transmitted to the inside of the phosphor film 222, and the fluorescent light output is low.

  Therefore, by providing the reflection preventing layer 221 having the function of reducing the reflectance of excitation light to 1% or less on the surface of the phosphor film 222, the reflectance of the excitation light becomes smaller and the fluorescent light output becomes higher. The antireflection layer 221 may have a surface reflectance of 1% or less with respect to vertical incident light of excitation light, and may be formed of a single layer or a plurality of layers.

(Adhesive layer 230)
The adhesive layer 230 is not particularly limited in its material, film thickness, etc., but it does not interfere with the heat generated when converting the excitation light generated in the phosphor layer 220 to fluorescent light to the substrate 210. Thus, it is desirable to have heat dissipation. For example, as shown in FIG. 3, since the adhesive layer 230 located between the first light reflection layer 223 and the substrate 210 does not require light transmission, an adhesive containing an organic component such as a solder containing a metal component or a silicon resin is used. The adhesive layer 230 used may be used.

  As another example, as shown in FIG. 4, the phosphor member 200 a applies a light reflection layer to the phosphor layer side surface (surface) 210 a of the phosphor layer holding portion 211 and makes the first light reflection layer 223 a a phosphor layer You may form integrally with the holding part 211. FIG. In this case, the phosphor layer 220a is formed to include the adhesive layer 230a disposed on the first light reflection layer 223a, and the phosphor film 222 and the anti-reflection layer 221 sequentially stacked thereon. Furthermore, the phosphor layer 220 a includes the inner light reflection layer 224 a covering the adhesion layer 230 a, the phosphor film 222, and the radially inner side surface of the antireflection layer 221, the adhesive layer 230 a, the phosphor film 222, and the antireflection layer 221. And an outer light reflecting layer 225a covering the radially outer surface. The adhesive layer 230a included in the phosphor layer 220a is configured using a light transmitting member such as silicon.

  With reference to FIG.5, FIG.6, FIG.7, the effect of the fluorescent substance member 200,200a which concerns on this embodiment is demonstrated. FIG. 5 is a figure which shows the effect of the light reflection layer regarding the output of fluorescence light. FIG. 6 is a view showing the phosphor film size with respect to the laser spot diameter. FIG. 7 is a view taken by a luminance meter when the phosphor film is irradiated with excitation light.

  The left view of FIG. 5 shows an example in which the back surface and the side surface of the phosphor film 222 are exposed. In this example, the phosphor film 222 is disposed, and the light reflection layer is not provided.

  As shown in the left example of FIG. 5, since the fluorescent light emitted from the phosphor particles of the phosphor film 222 is emitted in all directions, part of the emitted fluorescent light is on the back surface or side surface of the phosphor film 222, In addition, the light is output from the emission surface (which also serves as the incident surface of the excitation light) 222a of the fluorescent light, but the rest is repeatedly attenuated in transmission and reflection between the phosphor particles in the phosphor film 222 and the binder. To lose money. Therefore, in the left example of FIG. 5, only a part of the fluorescent light emitted from the phosphor particles is emitted from the emission surface 222 a of the phosphor film 222.

  On the other hand, in the right example of FIG. 5, the back surface and the side surface of the phosphor film 222 are covered with the first light reflection layer 223, the inner light reflection layer 224, and the outer light reflection layer 225.

  Furthermore, in the right example of FIG. 5, the phosphor film size is smaller than that of the left example. Specifically, as shown in FIG. 6, the radial width of the phosphor film size is formed within a range of 1 to 3 times the radial width of the laser spot.

  Thus, among the fluorescent light irradiated from the phosphor particles in the fluorescent substance film 222, the fluorescent light irradiated to the side direction of the fluorescent substance film 222 has an optical path length shorter than that of the conventional example. The radially inner surface or the radially outer surface is reached. Then, the fluorescence light and the excitation light transmitted through the phosphor film 222 are reflected toward the inside of the phosphor film 222 by the inner light reflection layer 224 and the outer light reflection layer 225. As a result, the loss due to the fluorescent light being output from the back surface or the side surface of the phosphor film 222 is prevented, and the output surface of the phosphor film (which also serves as the incident surface of excitation light) can be taken out with higher output. Further, since the excitation light transmitted through the phosphor film 222 is also reflected toward the phosphor film 222, it can be converted into fluorescence light to increase the fluorescence light output.

  As shown in FIG. 7, when excitation light is incident on the phosphor film 222, a light emission point centered on the laser spot 400 is generated in the phosphor film 222. Around the light emitting point, fluorescence light is repeatedly transmitted and reflected to cause loss. The size of the diffusion region is three to five times larger than the size of the light emitting point. Therefore, the diffusion region can be further narrowed by setting the size of the phosphor film 222, specifically, the radial width to 1 to 3 times the incident diameter of the laser spot. As a result, the loss of fluorescent light in the phosphor film 222 can be reduced, and the output of fluorescence can be increased.

  As described above, according to the present embodiment, the first light reflection layer 223 and the second light reflection layer (the inner light reflection layer 224 and the outer light reflection layer 225 in the above example) are disposed on the back surface and the side surface of the phosphor film 222 Thus, the loss due to the fluorescence light and the excitation light being emitted from the back surface and the side surface of the phosphor film 222 is prevented.

  In addition, by making the phosphor film size interlock with the incident diameter of the laser spot 400, the attenuation of the fluorescent light in the fluorescent film is suppressed, and the loss of the fluorescent light is prevented.

  This embodiment does not limit the present invention. For example, although the phosphor wheel is used as the substrate in the above, the invention is not limited to the substrate of the rotating body, and a substrate made of a plate-like fixed body may be used. The substrate of the rotating body can improve the heat dissipation of the phosphor film more than the case of using the substrate of the fixed body, and thus can improve the efficiency of taking out fluorescent light. On the other hand, in the substrate of the fixed body, the formation of the substrate can be performed more easily than the rotating body. Also in the phosphor member disposed on the substrate of the fixed body, the size of the phosphor film is formed in conjunction with the incident diameter of the laser spot.

  Moreover, in the said embodiment, although the projector was mentioned as an example as a usage example of the light source device using the fluorescent substance member which concerns on this invention, you may use for a headlight.

1: Projector 100: light source device 200, 200a: phosphor member 210: substrate 220, 220a: phosphor layer 221: antireflection layer 222: phosphor film 223: first light reflection layer 224: inner light reflection layer 225: outside Light reflective layer 230, 230a: Adhesive layer

Claims (6)

A substrate,
And a phosphor layer disposed on the substrate.
The phosphor layer is
A phosphor film including phosphor particles for converting excitation light into fluorescence light;
A first light reflecting layer disposed in contact with the side surface of the substrate in the phosphor film and reflecting the excitation light and the fluorescent light emitted from the side surface of the substrate toward the phosphor film;
And a second light reflecting layer disposed so as to surround a side surface of the phosphor film and reflecting the excitation light or the fluorescent light emitted from the side surface toward the phosphor film.
A phosphor member characterized by The phosphor member according to claim 1, wherein
The first light reflecting layer is integrally formed on the side surface of the substrate,
It further includes an adhesive layer adhering the phosphor layer side surface of the substrate and the substrate side surface of the first light reflecting layer.
A phosphor member characterized by The phosphor member according to claim 1, wherein
The first light reflecting layer is integrally formed on the side surface of the phosphor layer on the substrate,
It further includes an adhesive layer having a light transmitting property, which adheres the side surface of the phosphor layer in the first light reflecting layer and the side surface of the substrate in the phosphor film,
The second light reflecting layer is disposed to further surround the side surface of the adhesive layer.
A phosphor member characterized by A phosphor member according to any one of claims 1, 2, or 3.
The phosphor layer is
The phosphor with a reflectance lower than the reflectance when the excitation light is incident from the air layer to the phosphor film on the incident surface of the excitation light located on the opposite side to the side surface of the substrate in the phosphor film Further comprising an antireflective layer for causing the excitation light to enter the film,
The second light reflecting layer is disposed to further surround the side surface of the antireflective layer.
A phosphor member characterized by The phosphor member according to claim 1, wherein
The incident surface of the excitation light located on the opposite side to the side surface of the substrate in the phosphor film is formed to have a width of 1 to 3 times the incident diameter on which the excitation light is incident.
A phosphor member characterized by A phosphor member according to claim 1;
And an excitation light source generating the excitation light.