Fluorescent plate, light source device and projection video display device

Abstract

To achieve a high luminosity of a light source device including phosphor emitting fluorescence by excitation light from a solid light source by improving the luminous efficiency of phosphor.SOLUTION: A fluorescent plate 10 includes: a flat support base material 11; a reflective film 12 provided on the surface of the flat support base material 11; a reflective layer 13 provided on the reflective film 12 and constituted of a metal oxide 13r and a transparent binder 13b; and a phosphor layer 14 provided on the reflective layer 13. The reflective layer has a thickness of 10 μm or more and below 90 μm or less, and the metal oxide has a volume concentration of 15-40 vol%.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a fluorescent screen, a light source device, and a projection-type image display device. [Background technology]

[0002] Conventionally, high-intensity mercury lamps have been used as light sources for projectors. However, high-pressure mercury lamps cannot be turned on instantly and have a short light source life, making maintenance difficult. On the other hand, recent solid-state light-emitting devices (e.g., semiconductor lasers, light-emitting diodes) With the advancement of technology (such as solid-state light sources), it has become possible to use these solid-state light sources as light sources for image display devices. It has been proposed that:

[0003] The light source device described in Patent Document 1 efficiently extracts the fluorescent light emitted by the phosphor wheel. Therefore, silver vapor deposition is applied to the surface of the metal substrate, which allows the fluorescent light emitted from the metal substrate side to be highly The structure is disclosed in which the light is reflected by the reflectance and efficiently extracted together with the fluorescence emitted toward the excitation light source. are.

[0004] Furthermore, the light source device described in Patent Document 2 is capable of achieving high reflectivity on the surface of a metal substrate at a lower cost. To achieve this, a titanium oxide layer is applied between the metal substrate and the phosphor layer. It has been done. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-53320 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-228598 Summary of the Invention [Problem to be solved by the invention]

[0006] The present disclosure aims to suppress the temperature rise of the phosphor layer while maintaining high substrate reflectivity and achieving high conversion efficiency. The present invention provides a fluorescent screen, a light source device, and a projection-type image display device that realize this. [Means for solving the problem]

[0007] The fluorescent screen of the present disclosure includes a support substrate and a metal oxide and a transparent binder disposed on the support substrate. and a phosphor layer provided on the reflective layer. The particle size is 10 μm or more and 90 μm or less, and the volume concentration of the metal oxide is 15 to 40 vol%. do.

[0008] The present disclosure further provides a light source device including the fluorescent plate of the present disclosure, and a projection-type image display device. It is served. [Effects of the Invention]

[0009] The fluorescent screen of the present disclosure can maintain a high conversion efficiency from excitation light to fluorescence, and can also It is possible to realize a light source device that suppresses temperature rise in the layer. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating the configuration of a phosphor wheel assembly including a phosphor screen according to the first embodiment; [Figure 2] 1 is a diagram showing the configuration of a reflective layer and a phosphor layer of a fluorescent plate according to Embodiment 1. [Figure 3] 1 is a diagram showing the diffuse reflectance of a reflective layer versus the volume concentration of metal oxide. [Figure 4] 1 is a diagram showing the diffuse reflectance of a reflective layer relative to the thickness of the reflective layer; [Figure 5] 1 is a diagram illustrating the configuration of a light source device and a projection-type image display device according to a first embodiment. [Figure 6] FIG. 1 is a diagram illustrating the concept of the light emission process of a fluorescent screen according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing the configuration of a fluorescent screen assembly according to a second embodiment. [Figure 8] 10 is a diagram showing the configuration of a light source device and a projection-type image display device according to a third embodiment; [Figure 9] 10 is a diagram showing the configuration of a phosphor wheel assembly including a phosphor screen according to a third embodiment. [Figure 10] 10 is a diagram illustrating the configuration of a color wheel assembly according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, the embodiments will be described in detail with reference to the drawings as appropriate. For example, detailed explanations of well-known matters or matters that are substantially the same may be omitted. This is because the following explanation may be unnecessarily redundant. The accompanying drawings and the following description are for the purpose of avoiding confusion and facilitating understanding by those skilled in the art. , are provided to enable those skilled in the art to fully understand the present disclosure, and are intended to It is not intended to limit the scope of the subject matter described herein.

[0012] In addition, the following description will be made in conjunction with the drawings of the light source device and the projection-type image display device according to the embodiments of the present disclosure. In the drawings, the same or similar parts are denoted by the same or similar reference numerals. Please note that this is a schematic diagram and the proportions of each dimension may differ from those of the actual model. Therefore, specific dimensions should be determined by taking into consideration the following explanation. Of course, there are parts between which the dimensional relationships and ratios differ.

[0013] In the following embodiments, a light source device according to the present disclosure is used in a projection-type image display device. However, the device using the light source device of the present disclosure is not limited to this. The lamp may not be a lamp that is mounted on a vehicle, but may be a lighting device such as a headlamp.

[0014] (Embodiment 1) The fluorescent screen, the light source device, and the projection-type image display device according to the first embodiment will be described below with reference to the drawings. This will be explained with reference to the surface.

[0015] (Configuration of the fluorescent screen and the phosphor wheel equipped with the fluorescent screen) FIG. 1 shows the configuration of a phosphor wheel assembly 18 having a phosphor screen 10 according to the first embodiment. 1A is a diagram showing the phosphor wheel as viewed from the +z direction, which is the incident side of the excitation light. The front view of the assembly 18, FIG. 1(b), is a view of the + in the 1b-1b plane shown in FIG. 1(a). FIG. 10 is a schematic diagram for explaining a cross section seen from the x direction.

[0016] As shown in FIG. 1, the fluorescent screen 10 is made up of a disk-shaped flat support substrate 11 and a flat support substrate 12. a reflective film 12 provided on the surface of the substrate 1; and a reflective layer 13 provided in an annular shape on the reflective film 12. The fluorescent layer 14 is formed in an annular shape on the reflective layer 13. The assembly 18 is made up of the fluorescent screen 10, the motor 15, and the balance plate 16, and is secured with three screws. The motor 15 is fixed by being clamped by the hub 17 (not shown). The motor 15 drives the disk-shaped flat plate support substrate 11 to rotate.

[0017] The fluorescent screen 10 is fixed to the housing via a mounting portion (not shown) of the motor 15. The balance plate 16 is controlled by the control unit. It is a metal member that adjusts the rotation balance of the wheel assembly 18, and is, for example, a balance plate. The balance is adjusted by cutting a part of the part.

[0018] The phosphor wheel assembly 18 rotates the phosphor screen 10 with the motor 15. This dissipates heat accumulation in the phosphor layer 14 and cools the phosphor layer 14 .

[0019] The flat support substrate 11 is a disk-shaped metal substrate, and has, for example, high thermal conductivity, workability, and compactness. The reflective film 12 is made of an aluminum substrate having excellent cost performance. It is a reflective film that increases reflectivity, for example, an aluminum reflection coating made of metal or a dielectric multilayer coating. It is composed.

[0020] The structures of the reflective layer 13 and the phosphor layer 14 of the fluorescent screen 10 will be described with reference to FIG.

[0021] The reflective layer 13 is a highly reflective layer made by kneading a transparent binder 13b with a metal oxide 13r. The reflective layer 13 is a highly reflective coating material that is applied in a circular pattern to the surface of the reflective film 12. The paint has a volume concentration of metal oxide 13r of 15 to 40 vol%, and the rest is mostly transparent. It is a white paint filled with a bright binder 13b and has high reflectivity in the visible light range. .

[0022] The transparent binder 13b is, for example, a silicone having high visible light transmittance and excellent heat resistance. The metal oxide 13r is, for example, titanium oxide having a high refractive index. The reflective layer 13 achieves reflection by scattering light due to the high refractive index of titanium oxide. In order to achieve the radiation effect, the particle size of the titanium oxide is preferably 0.15 to 0.4 μm. .

[0023] The phosphor layer 14 is made of a phosphor layer formed by kneading a powder of phosphor 14p into a transparent binder 14b. The light-emitting layer 13 is a mixture of light-emitting elements and is formed on the surface of the reflective layer 13, which is applied in a circular shape on the reflective film 12. The phosphor mixture of the phosphor layer 14 has a volume concentration of the phosphor 14p of 30 vol % or more. It is a phosphor mixture that emits fluorescence when exposed to excitation light E. The excitation light intensity is 20 W / mm2 or more. In order to achieve high efficiency fluorescence even at the high light density, the particle size of the phosphor 14p is set to be smaller than that of the metal oxide 13r. The particle size is larger than that of the

[0024] The transparent binder 14b is, for example, a silicone having high visible light transmittance and excellent heat resistance. The transparent binder 14b constituting the phosphor layer 14 is a resin. It is preferable that the material is the same as the transparent binder 13b that constitutes the reflective layer 13 and the phosphor layer. By using the same transparent binder for the reflective layer 13 and the phosphor layer 14, refraction at the interface between the reflective layer 13 and the phosphor layer 14 is prevented. This eliminates the refractive index difference, and reduces the light loss due to refraction and reflection at the interface. 4p is, for example, a yellow dye with a dominant wavelength of about 570 nm that is excited by blue light with a wavelength of about 455 nm. Yellow phosphor Py (e.g., YAG phosphor, Y3Al5O12:Ce3+) that emits light of Preferably, the particle size of the yellow phosphor Py is 20 to 30 μm.

[0025] Although silicone resin was shown as a transparent binder, other transparent binders such as epoxy and acrylic are also available. Transparent glass made by fusing organic materials, sodium silicate, glass frit, and ceramic powder. Inorganic materials can also be used.

[0026] Titanium oxide was shown as a metal oxide, but zinc oxide and zirconium oxide can also be used. be.

[0027] The fluorescent material used was a mixture of yellow YAG fluorescent material and silicone resin, while the green LA fluorescent material was G phosphor (Lu3Al5O12:Ce3+), orange or red silicate phosphor, etc. Alternatively, it may be a ceramic phosphor plate.

[0028] 3, the relationship between the volume concentration of the metal oxide 13r and the diffuse reflectance of the reflective layer 13 is The volume concentration in this embodiment is the volume concentration of the mixture of the metal oxide and the transparent binder. The diffuse reflectance in this embodiment is the volume ratio of the metal oxide to the total amount of the metal oxide. is the amount of light energy absorbed by the reflective layer out of the total amount of light energy incident on the reflective layer. This refers to the total amount of energy of reflected light.

[0029] FIG. 3 shows the reflection layer 13 when titanium oxide (TiO2) is used as the metal oxide 13r. 1 is a graph showing the relationship between volume concentration and diffuse reflectance for thicknesses of 10 to 90 μm. As can be seen from the graph, when the film thickness of the reflective layer 13 is increased at the same volume concentration, The overall diffuse reflectance becomes large, and the thinner the film, the smaller the diffuse reflectance. The film thickness of the reflective layer 13 shown in the figure is a value measured by a contact method.

[0030] Specifically, as is clear from FIG. 3, the diffuse reflectance of the reflective layer 13 is The thickness of the reflective layer 13 also shows a quadratic curve with a peak at a volume concentration of about 30 vol %. At a diameter of 30 μm or more, a high reflectance of 95% or more is maintained at a volume concentration of 15 to 45 vol%. It can be seen that even when the thickness of the reflective layer 13 is 10 μm, the volume concentration is 15 to 40 μm. It can be seen that within the 0.5% range, the diffuse reflectance remains sufficiently high at 90% or more.

[0031] Generally, the average reflectance of visible light from an aluminum enhanced reflection coating formed on an optically polished glass surface is 94 %, and in the deposition on the surface of a metal substrate as shown in the present disclosure, the surface roughness Therefore, in the reflective layer configuration of the present disclosure, the film thickness is By increasing the particle size to 30 μm or more, the particle size is increased by 95% or more at a volume concentration of 15 to 45 vol% or more. This allows for a high degree of diffuse reflectance and improves the fluorescent light emission efficiency. When the volume concentration of the metal oxide 13r relative to the underlayer 13b is increased, the viscosity of the paint is Therefore, in order to stably produce a thin film of a reflective layer of 90 μm or less, the volume concentration The limit for the thickness of the reflective layer is about 40 vol%. When the volume concentration is 30 vol%, the diffuse reflectance is 100%, so this thickness of 90 μm is This is because it can be considered as the upper limit of the thickness of the spray layer.

[0032] Therefore, in the reflective layer 13 of the present disclosure, the volume concentration of the metal oxide 13r is 15 to 40 vol It is clear that it is desirable to set it to 1%.

[0033] 2, the reflective layer 13 and the phosphor layer 14 on the surface of the reflective film 12 of the fluorescent screen 10 are The reflective layer 13 is provided in close contact with the surface of the reflective film 12, and may be, for example, The phosphor layer 14 is applied to the surface of the reflective film 12 by dispensing. It is provided in close contact with the surface of the reflective layer 13, for example, by applying it by dispensing.

[0034] Here, if the thickness of the reflective layer 13 is Lr and the thickness of the phosphor layer 14 is Lp, the thickness of the two layers is The relationship is Lp>Lr, and the thickness of the reflective layer 13 is Lr≦90 μm. The width of the reflective layer 13 is Wr, the width of the phosphor layer 14 is Wp, and the width of the phosphor layer 14 is Wp. If the spot size of the excitation light on 14 is Φi, then Wr>Φi and Wp>Φi.

[0035] The relationship between the thickness of the reflective layer 13 and the diffuse reflectance of the reflective layer 13 will be explained with reference to FIG. 4. Figure 4 shows the results when titanium oxide is used as the metal oxide 13r and the volume concentration is 30 vol%. 1 is a graph showing the relationship between film thickness and diffuse reflectance in a flat support substrate 1. This is the case where an aluminum enhanced reflection film, which is a reflective film 12, is applied to the surface of the aluminum substrate, which is 1. shows a case where the reflective film 12 is not provided on the aluminum substrate, which is the flat support substrate 11. The diffuse reflectance increases in proportion to the film thickness. It can be seen that the volume concentration of the reflective layer 13 is 99% or more and is saturated. As a result, the overall diffuse reflectance increases, and as the volume concentration decreases, the diffuse reflectance decreases. Therefore, with respect to the thickness of the reflective layer 13, when the reflective film 12 is included, the volume concentration is set to 30 vol %, the graph in Figure 4 also shows that if the range is 20 μm or more, the diffuse reflectance is 95 % or more. This is shown in FIG. 10, which shows the effect of the reflective film 12. 4 will be used for further explanation.

[0036] In the graph of FIG. 4, the dashed line indicates the case where the reflective film 12 is not present, and the solid line indicates the case where the reflective film 12 is present. Even if the reflective film 12 is not provided, the reflective layer thickness is 100 μm or more. If the reflecting film 12 is provided, the same diffuse reflectance as that obtained when the reflecting film 12 is provided can be obtained. Increasing the thickness of the reflective layer 13 increases the excitation of fluorescence in the phosphor layer 14 provided on the reflective layer 13. This means that the efficiency of guiding the heat generated in the process to the flat plate support substrate 11 decreases. As the temperature of the light-emitting layer 14 rises, the light-emitting efficiency may decrease. However, the reflective layer 13 acts as a heat insulator, which hinders the cooling of the phosphor layer 14. In order to achieve a reflectivity of 95% or more, which is higher than the reflectivity of the aluminum enhanced reflection coating, If the film 12 is not provided, the thickness of the reflective layer 13 must be 80 μm or more. When the reflective film 12 is provided, the diffuse reflectance is 95% or more with a reflective layer 13 thickness of 20 μm. It is possible to achieve this by reducing the thickness of the reflective layer 13 from 80 μm to 20 μm, and by reducing the thickness to 60 μm. This can improve the cooling effect on the phosphor layer 14. It becomes possible.

[0037] As described above, when the volume concentration of the reflective layer 13 is in the range of 15 to 40 vol %, Even with a thickness of 10 μm, the diffuse reflectance is 90% or more, which is a sufficiently high reflectance. When the thickness of the layer 13 is 30 μm or more, the diffuse reflectance is as high as 95%. The upper limit of the layer thickness is 90 μm as mentioned above, which is the condition for obtaining high reflectivity. The thickness of the reflective layer 13 is 10 μm or more and 90 μm or less, and the metal contained in the reflective layer The volume concentration of the oxide is in the range of 15 to 40 vol %. When expressed as vol%, the thickness of the reflective layer is 10 to 50 μm, i.e., in the range of 30±20 μm. In other words, the thickness of the reflective layer that can be manufactured to obtain a uniform film thickness is 10 μm. This is the limit of thinness, and the thickness is set to 50 μm, at which the reflectivity is close to 100%. It is desirable to determine

[0038] (Outline of the light source device and projection-type image display device) FIG. 5 is a diagram showing the optical configuration of the projection display device 100 according to the first embodiment.

[0039] The projection-type image display device 100 includes a light source device 20 that emits white light W as reference light, and a light source The light from the device 20 is homogenized and color-separated, and then transmitted to three liquid crystal panels (LCDs) that are spatial modulation elements. The image signal is input from an external device and illuminated onto a Liquid Crystal Display (LCD). The lighting device 40 combines the colors of the image light modulated by the three LCDs based on the signal. and a projection lens 60 that projects the image light onto a screen in an enlarged scale. The projection-type image display device 100 of this embodiment includes three projection lenses that modulate illumination light in response to a video signal. This is a projection type image display device equipped with an LCD 50 (an example of an image modulation element).

[0040] (Configuration of light source device) The light source device 20 includes a light source 30. The light source 30 is a semiconductor laser 3 The semiconductor laser 31 is a solid-state optical The light source 30 is an example of an excitation light source.

[0041] The semiconductor laser 31 emits blue laser light (for example, For example, the semiconductor laser 31 emits a reference light having a wavelength of 455 nm. Several of these are arranged in a matrix to form an array light source 33. The rear side of the array light source 33 is provided with a heat sink for forced air cooling. The collimator lens 32 disposed on the output side of the semiconductor laser 31 collimates the emitted light of the semiconductor laser 31 into a substantially uniform beam. Concentrates light into parallel beams.

[0042] The blue laser light emitted from the light source 30 is condensed by the condenser lens 34 and superimposed. The light beam is then reduced in size by the concave lens 35 and made into approximately parallel light, which is then diffused by the diffusion plate 36a. The light then passes through the λ / 2 wave plate 36 b and enters the dichroic mirror 37 . The dichroic mirror 37 transmits the P-polarized blue laser light and outputs the S-polarized blue laser light. Here, the blue laser light emitted from the semiconductor laser 31 is reflected by a specific linearly polarized light. The λ / 2 wave plate 36b rotates the polarization direction of the incident linearly polarized blue laser light. Therefore, by adjusting the rotation angle of the λ / 2 wave plate 36b, the dichroic mirror The polarization direction of the blue laser light incident on the dichroic mirror 37 is adjusted and the light passes through the dichroic mirror 37. This makes it possible to adjust the P-polarized component that is transmitted and the S-polarized component that is reflected.

[0043] The blue laser light, which is P-polarized light and has passed through the dichroic mirror 37, is focused by the lens 38. After passing through the λ / 4 wavelength plate 39a, it is reflected by the reflecting mirror 39b and becomes λ / 4 wavelength again. By passing through the plate 39a, the polarized light component is rotated by 90 degrees to become S-polarized light, and is then reflected back to the die 39a. The light is reflected by the chromatic mirror 37.

[0044] The blue laser light, which is S-polarized light reflected by the dichroic mirror 37, passes through the lens 22 and the lens The light is focused by the lens 21 onto the phosphor layer 14 of the phosphor wheel assembly 18 as excitation light E for fluorescent emission. The excitation light E incident on the phosphor layer 14 is guided to the phosphor wheel assembly 1 The fluorescent light F, which has a wavelength band different from that of the excitation light E, is excited by the fluorescent layer 14 of the fluorescent wheel 8. The fluorescent light F exiting the assembly 18 is collimated by a collimator lens consisting of a lens 21 and a lens 22. The light is collimated by the lens group and enters the dichroic mirror 37 again. The blue laser light, which is the S-polarized component reflected by the mirror 37, is guided to the illumination device 40. The lenses 21 and 22 are an example of a light-collecting optical system.

[0045] Here, in the light source device 20, the fluorescence F is converted into yellow light by the excitation light, which is blue laser light. The light source device 20 is configured to superimpose the blue laser light and the fluorescent yellow light. When folded, white light W is emitted.

[0046] (Overall composition) The white light W emitted from the light source device 20 is reflected by the lens array 41a, the lens array 41b, and the polarized light. The conversion element 42 and the condenser lens 43 uniformly illuminate the LCD 50. The white light W emitted from the condenser lens 43 is reflected by the dichroic mirror 44C. The light is split into light Lr and cyan composite light Lc, which is a combination of green reference light Lg and blue reference light Lb. The combined light Lc is split into green reference light Lg and blue reference light Lb by the dichroic mirror 45G. Here, the lens array 41a, the lens array 41b, the polarization conversion element 42, the condenser The sensor lens 43 and the dichroic mirrors 44C and 45G constitute an illumination optical system.

[0047] The red reference light Lr is reflected by the mirror 45R, and then passes through the lens 46R and the incident-side polarizing plate 47R. The light is modulated into image light by the red LCD 50R and then passes through the output polarizer 48R to the color synthesis plate Guided by Rhythm 49.

[0048] The green reference light Lg is reflected by the dichroic mirror 45G, and then enters the lens 46G. The light is transmitted through the output polarizer 47G, modulated into image light by the green LCD 50G, and then passes through the output polarizer 48G. The light is then guided to a color synthesis prism 49.

[0049] The blue reference light Lb passes through mirror 45Ba, lens 45Bb, and mirror 45Bc and enters the lens. The light is transmitted through the lens 46B and the incident side polarizing plate 47B, and is modulated into image light by the blue LCD 50B. The light is guided to color synthesis prism 49 through polarizing plate 48B.

[0050] The blue reference light Lb, green reference light Lg, and red reference light Lr modulated into the image light are fed to the color synthesis printer. The images are then combined by a lens 49 and enlarged and projected onto a screen (not shown) by a projection lens 60. The LCD 50, which is a spatial modulation element, and the color synthesis prism 49 constitute an image generation unit. The projection lens 60 is an example of a projection optical system.

[0051] (Explanation of the light emission process on a fluorescent screen) Referring to FIG. 6, excitation light E incident on phosphor layer 14 passes through phosphor layer 14. In this case, the light is absorbed by the phosphor contained in the phosphor layer 14, and emits fluorescent light. Since the fluorescence emitted from the emitting surface is emitted in all directions, the incident surface of the excitation light E, which is the light extraction surface, At the same time as the fluorescence F1, which is a component that travels to the reflective layer 13 side, which is the incident direction of the excitation light E, The fluorescent light F2 is transmitted through the phosphor layer 14 and incident on the reflective layer 13, where it is reflected. The fluorescence F3 is a component that is reflected by the reflective layer 13 and travels toward the incident surface of the excitation light E, and the fluorescence F4 is a component that is transmitted through the reflective layer 13. The fluorescence F4 is then transmitted through the reflective layer 13 and reflected by the reflective film 12. On the other hand, the excitation light E that is not absorbed by the phosphor layer 14 is absorbed by the phosphor layer 14. The excitation light E1 is an excitation light component that passes through the phosphor layer 14 and is reflected by the reflective layer 13. The component E2 passes through the reflective layer 13 and is reflected by the reflective film 12, which is the excitation light E3. The light E2 and the excitation light E3 also cause the phosphors in the phosphor layer 14 to emit light and become fluorescent light F5. The component of the excitation light E2 and the excitation light E3 that is not absorbed by the phosphor layer 14 is emitted as excitation light E4. The phosphor layer 14 emits light.

[0052] Therefore, the fluorescence F converted by the excitation light E on the fluorescent screen 10 is expressed as follows: F=F1+F2+ The fluorescent screen 10 receives the fluorescent light E that is not converted. The light source layer 14 emits excitation light E4 and fluorescence F.

[0053] (effect) In this embodiment, the fluorescent screen 10 has a reflective film 12 provided on the surface of a flat support substrate 11. a reflective layer 13 provided on the reflective film 12; and a phosphor layer 14 provided on the reflective layer 13. By providing this, the luminous efficiency of the fluorescent light F relative to the excitation light E is improved, and the brightness of the light source device is increased. Furthermore, by providing the reflective film 12, sufficient reflectivity can be achieved even if the thickness of the reflective layer 13 is reduced. The heat of the phosphor layer 14 can be appropriately dissipated to the flat support base 11, and the temperature of the phosphor layer 14 can be It is possible to lower

[0054] (Embodiment 2) FIG. 7 is a diagram illustrating a configuration of a fluorescent screen assembly according to the second embodiment of the present disclosure. 1 are assigned the same reference numerals, and only the differences from the first embodiment are shown. , mainly explains.

[0055] In the first embodiment, a disk-shaped substrate is used as the flat support substrate 11, and the circular substrate is used as the motor 1. 5 is an example of a fluorescent plate and a light source device using a rotating phosphor wheel assembly 18. The phosphor layer 14 is cooled by being rotated by the motor 15. In the second embodiment of the present disclosure, A fixed fluorescent screen using a flat cooling substrate 151 that also serves as a heat sink with cooling function. The fluorescent screen assembly 181 in the second embodiment is the same as that in the first embodiment. It can be used to replace the phosphor wheel assembly 18 in FIG.

[0056] (Configuration of fluorescent screen and light source device) FIG. 7 shows the configuration of a fluorescent screen assembly 181 including a fluorescent screen 101 according to the second embodiment. 7 is a side view seen from the +x direction.

[0057] As shown in FIG. 7, the fluorescent screen assembly 181 includes a fluorescent screen 101 and a cooling fan 191. The fluorescent screen 101 is made up of a flat cooling substrate 151 that also serves as a heat sink for cooling, and a flat cooling The reflective film 112 formed on the surface of the substrate 151 and the reflective film 112 formed at the center of the surface of the reflective film 112 The flat cooling substrate is made up of a layer 131 and a phosphor layer 141 formed on the reflective layer 131. A heat sink structure is provided on the surface of the material 151 opposite to the surface on which the reflective film 112 is formed, and cooling is performed. Forced air cooling is provided by a fan 191.

[0058] The flat cooling substrate 151 is, for example, a heat sink formed by extruding aluminum. The reflective film 112 is, for example, an aluminum high-reflection film. This is an example.

[0059] The reflective layer 131 is formed by kneading a transparent binder 131b with a metal oxide 131r. It is a highly reflective paint and also serves as an adhesive for adhering the phosphor layer 141 to the surface of the reflective film 112. The highly reflective paint that is the reflective layer 131 has a volume concentration of metal oxide 131r of 15%. 40 vol%, and the remainder is mostly filled with transparent binder 131b. It is a white adhesive with high reflectivity in the dark region.

[0060] The phosphor layer 141 is made by mixing a transparent binder 141b and a phosphor 141p and baking the mixture. The ceramic phosphor is bonded to the surface of the reflective film 112 via the reflective layer 131. The ceramic phosphor of the phosphor layer 141 has a volume concentration of phosphor 141p of 90 vol%. As a result, it is a phosphor ceramic that emits fluorescence when exposed to excitation light E. In order to obtain high luminous efficiency, the particle size of the phosphor 141p is larger than the particle size of the metal oxide 131r. stomach.

[0061] In the case of a ceramic phosphor, which is an inorganic phosphor layer 141, the phosphor layer 141 emits fluorescent light F when excited by excitation light E. The heat generated during the process can be transferred and dissipated with high thermal conductivity. By increasing the concentration of the metal oxide 131r in the reflective layer 131, the thermal conductivity of the reflective layer 131 is improved. It is possible to increase the conductivity, and further, by making the thickness of the reflective layer 131 thin, Therefore, the heat generated in the phosphor layer 141 can be transferred to the flat cooling substrate 151 with high efficiency. Therefore, the cooling effect of the cooling fan 191 enables highly efficient cooling of the phosphor layer 141. It becomes Noh.

[0062] Here, the phosphor 141p emits a light having a dominant wavelength of, for example, 455 nm when excited by blue light. Yellow phosphor Py (e.g., YAG phosphor, YAl) that emits yellow light at about 570 nm 5O12:Ce3+).

[0063] (Projector-type image display device overview) The fluorescent screen assembly 181 according to the second embodiment is similar to the projection type image display shown in FIG. 5 of the first embodiment. In a display device, it can be used to replace the phosphor wheel assembly 18. Similar to the phosphor wheel assembly 18, the phosphor plate assembly 181 emits yellow fluorescence. By combining this light with blue laser light, a light source device is constructed, realizing a projection-type image display device. It becomes possible.

[0064] Unlike the phosphor wheel assembly 18, the phosphor plate assembly 18 shown in the second embodiment 1 has no motor drive unit, so it is highly reliable in the presence of noise and vibration. It's effective.

[0065] (Embodiment 3) FIG. 8 shows the configuration of a light source device and a projection-type video display device according to a third embodiment of the present disclosure. In the following description, the same components as those in FIG. 5 are denoted by the same reference numerals, and the same reference numerals are used in the first embodiment. This section will mainly explain the differences between the two.

[0066] The projection-type image display device 100 according to the first embodiment shown in FIG. 5 has three spatial modulation elements. This is an example of a three-panel liquid crystal projector using the LCD 50, and the light generated by the light source device 20 The white light W is color-separated by the color separation optical system of the illumination device 40, and the color is modulated by a spatial modulation element for each color. The colors are individually guided to the LCD 50, and then the colors are recombined by the color combining prism 49 before being projected onto the image display. In the third embodiment shown in FIG. 8 of the present disclosure, a single spatial modulation element, DMD (D Single-panel DLP (registered trademark) with Digital Mirror Device An example of a projector using this method will be described.

[0067] (Outline of the light source device and projection-type image display device) FIG. 8 is a diagram showing the optical configuration of a projection-type image display device 200 according to the third embodiment.

[0068] The projection-type image display device 200 includes a light source device 120 that emits white light W as reference light, and a light An illumination device that uniformizes and separates the light from the light source device 120 and illuminates it onto a DMD, which is a spatial modulation element. The illumination light from the illumination device 140 is modulated in accordance with the video signal and displayed in RGB in a time-division manner. An image device 150 including a spatial modulation element that generates image light of each color, and a The projection type image display device of this embodiment is configured with a projection lens 160 for large projection. 200 is a DMD153, a spatial modulation element that modulates the illumination light according to the video signal. It is a projection-type image display device that is installed.

[0069] (Configuration of light source device) The light source device 120 includes a light source 30. The blue laser light emitted from the light source 30 is focused by a condenser lens. The light beam is condensed and superimposed by the lens 34, and the light beam is reduced by the concave lens 35 to approximately The light is collimated and diffused by a diffusion plate 136, and then enters a dichroic mirror 137. The chromatic mirror 137 reflects the blue laser light and transmits light in other wavelength bands.

[0070] The blue laser light reflected by the dichroic mirror 137 is fluorescently reflected by the lenses 22 and 21. The phosphor layer 114 (see FIG. 9) of the light wheel assembly 118 is excited to emit fluorescent light. The excitation light E incident on the phosphor layer 114 is condensed and guided as the light E. The fluorescent light F, which is in a wavelength band different from that of the excitation light E, is excited in the fluorescent layer 114 of the filter assembly 118. Fluorescence F emitted from the phosphor wheel assembly 118 upon excitation with excitation light E. is collimated by a collimator lens group consisting of lenses 21 and 22, and The light is incident on and transmitted through the dichroic mirror 137 and guided to the illumination device 140. The blue laser light guided to the phosphor wheel assembly 118 The blue laser light passing through 118 is collimated by a collimator consisting of lenses 121 and 122. The light is converted into approximately parallel light by the lens group, and passes through mirror 123, mirror 124, lens 125, and mirror 126. 6, is reflected again by the dichroic mirror 137, and is guided to the illumination device 140. The phosphor wheel assembly 118 will be described in detail later. 30 is disposed so that excitation light is incident on the phosphor layer 114 of the phosphor screen 110 .

[0071] In the light source device 120, the phosphor layer 114 in the phosphor wheel assembly 118 is , yellow and green fluorescent light is emitted in a time-division manner, and transmitted through the phosphor wheel assembly 118 in a time-division manner. By combining the blue laser light with the yellow laser light, yellow, green, and blue light are emitted from the light source device 120 in a time-division manner. Emits light.

[0072] The fluorescent light F and blue laser light emitted from the light source device 120 are incident on the illumination device 120 by the lens 138. The light is irradiated onto the color filter wheel 170 of the color filter wheel 140. Details will be provided below.

[0073] Blue laser light and a color filter wheel 170 trimmed to the desired color light. The fluorescent light F is emitted from the color filter wheel 170 and then passes through the rod integrator 142. is incident on

[0074] (Configuration of a projection-type image display device) The illumination device 140 includes a color filter wheel 170, a rod integrator 142, and , lens 143, lens 144, and lens 145. Rod integrator 1 The light emitted from 42 is relayed by lenses 143, 144, and 145. The light is then incident on the video device 150 as light emitted from the lighting device 140 .

[0075] The imaging device 150 receives light emitted from the lighting device 140 and generates an image. As shown in FIG. 8, a total reflection prism 152 and a The DMD153 (an example of an image modulation element) is a spatial modulation element that modulates the incident light. In this way, the illumination device 140 guides the light emitted from the light source device to the image modulation element. The imaging device 150 is an example of an image generating unit.

[0076] The total reflection prism 152 has a surface 152a that totally reflects light, and The incident light is guided to the DMD153. The DMD153 has multiple movable micromirrors. A control unit (not shown) adjusts the timing of the respective color reference lights incident on the respective units. The color reference light is changed by the video signal. The light modulated by the DMD 153 passes through the total reflection prism 152 and enters the projection system. The projection lens 160, which is a projection system, is The projection lens 160 projects the image light synthesized in time in an enlarged manner. Here is an example.

[0077] (Configuration of phosphor wheel and color filter wheel) The configuration of the phosphor wheel assembly 118 will be described with reference to Figure 9. (a) of Figure 9 shows 9(a) is a front view of the fluorescent screen 110 as viewed from the +z direction of FIG. 9(b). 9 is a schematic diagram illustrating a cross section of the −9b plane as viewed from the +x direction. The same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

[0078] The flat plate support substrate 111 in the third embodiment is the same as the disk-shaped flat plate support substrate of the first embodiment. Unlike the base material 11, it has a roughly disk-shaped surface with a cutout area 114b. The reflecting film 112 has a reflecting layer 113 on the surface thereof. 9(a), the reflective layer 113 is provided in a circular ring shape or a sector shape. On the top, a phosphor layer 114y and a phosphor layer 114g (the phosphor layer 114y and the phosphor layer 114g) The phosphor layers 114 are arranged in a sector shape.

[0079] The phosphor layer 114y emits light with a dominant wavelength of about 570 nm when excited by blue light with a wavelength of about 455 nm. The fluorescent material that emits yellow light is oriented around the flat support substrate 111. The coating is formed in a sector-shaped area that is a part of a circular ring centered on the rotation center.

[0080] The phosphor layer 114g emits light with a dominant wavelength of approximately 550 nm when excited by blue light with a wavelength of approximately 455 nm. The phosphor that emits green light is disposed around the flat support substrate 111. It is applied to a sector-shaped area that is a part of a circular ring centered on the rotation center.

[0081] The phosphor layer 114y is formed by disposing a yellow phosphor Py on the flat support substrate 111 via a transparent binder. The phosphor layer 114g is a layer in which a green phosphor Pg is applied to the surface of the reflective layer 113. The surface of the reflective layer 113 of the flat support substrate 111 is coated with the binder.

[0082] For example, Y3Al5O12:Ce3+ is used as the yellow phosphor Py. For example, Lu3Al5O12:Ce3+ is used as the light-emitting body Pg. As the resin, for example, a silicone resin is used.

[0083] The cutout region 114b of the flat support substrate 111 is a region where the flat support substrate 111 and the phosphor layer 11 4 is not provided, and the wavelength of the blue laser light, which is the excitation light E to be irradiated, is not changed. It penetrates easily.

[0084] A low refractive index layer 119 having a refractive index lower than that of the phosphor layer is provided on the surface of the phosphor layer 114. The low refractive index layer 119 reduces the difference in refractive index between the air and the phosphor layer 114. This reduces the surface reflection of the excitation light E incident on the phosphor layer 114 and improves the capture efficiency. The low refractive index layer 119 reduces the interface reflection of the fluorescence F emitted from the phosphor layer 114, Improves light extraction efficiency from layer 114.

[0085] The low refractive index layer 119 is formed by, for example, adding hollow silica particles to a transparent binder such as silicone resin. By mixing low refractive index particles with a lower refractive index than the transparent binder, the volume concentration of hollow silica is It is a nearly transparent coating with a thickness of 50 to 200 nm and contains 90 vol% or more of cellulose. The refractive index layer 119 may also be, for example, an AR deposition film as an anti-reflection film, which is a dielectric multilayer film. is.

[0086] The configuration of the color filter wheel 170 will be described with reference to FIG. 10. 10(a) is a front view of the color filter wheel 170 as viewed from the +z direction, and FIG. 10(b) is a front view of the color filter wheel 170 as viewed from the +z direction. FIG. 10 is a side view of the color filter wheel 170 as seen from the +x direction.

[0087] As shown in FIG. 10(b), the color filter wheel 170 includes a transparent substrate 171 and It is composed of a motor 15, a balance plate 16, and a screw 17. The motor 15 is a disk-shaped The motor 15 rotates the transparent substrate 171 by a control unit (not shown). For example, the transparent substrate 171 and the motor 15 are bonded at the hub of the motor. The balance plate 16 and the screws 17 are connected to the phosphor wheel assembly 118. are similarly provided.

[0088] The transparent substrate 171 is a disc-shaped transparent substrate, and has high transmittance over the entire visible range, for example. It is made up of a glass substrate.

[0089] The light incident surface of the transparent substrate 171 is provided with a reflector that reflects a part of the wavelength band of the incident light and outputs a desired color light. In order to realize this, a dichroic film 174 that transmits light in a desired wavelength range is provided. The transparent substrate 1 has color filters 174g, 174y, 174r, and 174b. The light exit surface of the lens 71 is provided with an anti-reflection film 175. The dichroic film 174 (color filter) The films 174g, 174y, 174r, and 174b are collectively referred to as the dichroic film 174. ) is an example of a reflective film in a color filter.

[0090] Here, the blue laser light, which is the excitation light E, causes yellow fluorescence Fy to be emitted from the phosphor layer 114y. In the phosphor layer 114g, green fluorescence Fg is excited, reflected, and emitted. The blue laser light passes through.

[0091] The color filter wheel 170 has four segments, as shown in FIG. 10(a). The first segment, color filter 174g, has a wavelength longer than 480 nm. High transmittance in the visible wavelength range, and in the short visible wavelength range of 480 nm or less The second segment is made up of a dichroic film with high reflectivity. The color filter 174y has high transmittance in the visible wavelength region longer than 480 nm. In addition, it is a dichroic material that has high reflectivity in the short visible wavelength range of 480 nm or less. The third segment, color filter 174r, is made of a thin film. High transmittance in the visible wavelength range longer than 600 nm, and short wavelengths of 600 nm or less It is made up of a dichroic film that has high reflectivity in the visible wavelength range. The transmission area 174b, which is the fourth segment, is an AR coating, which is an anti-reflection coating.

[0092] That is, the color filters 174g, 174y, and 174r filter out some wavelengths of the incident light. Reflect and cut the band and transmit light in the desired wavelength range to achieve the desired color light. Trim the image.

[0093] Here, the phosphor wheel assembly 118 and the color filter wheel 170 are the same. That is, the color filter wheel 170 is rotated in synchronization with the rotation speed. The four segments rotate once in the time corresponding to one frame (for example, 1 / 60 seconds). The rotation is controlled as follows.

[0094] Yellow fluorescent light F emitted from the phosphor layer 114y in the phosphor wheel assembly 118 y is the color filter 174y and the color filter The rotation control is adjusted so that the light is incident on the phosphor layer 114y. The sum of the angles of the color filters 174y and 174r is set to be the same. is set to.

[0095] When the yellow fluorescence Fy emitted from the phosphor layer 114y passes through the color filter 174y, It reflects visible light with a wavelength of 480 nm or less and blocks visible light with a wavelength longer than 480 nm. The yellow fluorescent light Fy emitted from the phosphor layer 114y is generated by transmitting the visible light. When transmitted through the color filter 174r, visible light with a wavelength of 600 nm or less is It reflects and transmits visible light with wavelengths longer than 600 nm to generate red reference light Lr. .

[0096] Green fluorescent light F emitted from phosphor layer 114g in phosphor wheel assembly 118 g is incident on color filter 174g in color filter wheel 170. Therefore, the angle of the phosphor layer 114g and the rotation control of the color filter 174g are adjusted. The angles of the green fluorescent light Fg emitted from the phosphor layer 114g are set to be the same. When transmitted through color filter 174g, visible light with a wavelength of 480 nm or less is Reflects and transmits visible light with wavelengths longer than 480 nm to generate green reference light Lg .

[0097] The excitation light E transmitted through the cutout region 114b in the phosphor wheel assembly 118 is , the rotation of the color filter wheel 170 is controlled so that the light is incident on the transmission area 174b of the color filter wheel 170. Therefore, the angle of the cutout area 114b and the angle of the transmission area 174b are adjusted. The excitation light E transmitted through the transmission region 174b is set to be equal to the blue reference light L Generate b.

[0098] (effect) By providing the low refractive index layer shown in this configuration, the efficiency of capturing excitation light can be improved, and Since the light extraction efficiency can be improved, the brightness of the light source device can be increased and the amount of fluorescent light that is not extracted can be reduced. It is possible to improve cooling efficiency by reducing heat generation due to light. [Industrial Applicability]

[0099] The present disclosure relates to a fluorescent screen excited by a light source device using an excitation light source, This is applicable to display devices. [Explanation of symbols]

[0100] 10 Fluorescent screen 11 Flat support base material 12 Reflective film 13 Reflective layer 13b Transparent binder 13r Metal oxides 14 Phosphor layer 14b Transparent binder 14p phosphor 15 Motor 16 Balance Plate 17 Bis 18 Phosphor Wheel Assembly 20 Light source device 21, 22 Lenses 30 light source 31 Semiconductor laser 32 Collimator lens 34 Condenser Lens 35 Concave Lens 36a Diffuser 36b λ / 2 wave plate 37 Dichroic mirror 38 Lens 39a λ / 4 wave plate 39b Reflective mirror 40 Lighting equipment 41a, 41b Lens array 42 Polarization conversion element 43 Condenser Lens 44C, 45G Dichroic Mirror 45R mirror 45Ba mirror 45Bb lens 45Bc Mirror 46R, 46G, 46B lenses 47R, 47G, 47B Incident polarizer 48R, 48G, 48B Output side polarizing plate 49 Color Synthesis Prism 50 LCD 50R Red LCD 50G Green LCD 50B blue LCD 60 projection lens 100, 200 Projection type image display device 101, 110 Fluorescent screen 111 Flat support base material 112 Reflective film 113 Reflective layer 114 Phosphor layer 114b Cutout area 114g, 114y phosphor layer 118 Phosphor Wheel Assembly 119 Low refractive index layer 120 Light source device 121, 122, 125 lenses 123, 124, 126 Mirror 131 Reflective layer 131b Transparent binder 131r metal oxide 136 Diffuser 137 Dichroic Mirror 138 Lens 140 Lighting Equipment 141 Phosphor layer 141b Transparent binder 141p phosphor 142 Rod Integrator 143, 144, 145 lenses 150 Video equipment 151 Flat plate cooling base material 152 Total Reflection Prism 152a side 153 DMD 160 projection lens 170 Color Filter Wheel 171 Transparent substrate 174 Dichroic Film 174b Transparent area 174g, 174y, 174r color filters 181 Fluorescent Screen Assembly 191 Cooling fan

Claims

1. A supporting substrate; a reflective layer provided on the support substrate and composed of a metal oxide and a transparent binder; a phosphor layer provided on the reflective layer, The reflective layer is The thickness is 10 μm or more and 90 μm or less, A fluorescent screen in which the volume concentration of the metal oxide is 15 to 40 vol %.

2. The thickness Lp of the phosphor layer and the thickness Lr of the reflective layer have a relationship of Lp>Lr.

2. The fluorescent screen according to claim 1.

3. The thickness of the reflective layer is 30±20 μm when the volume concentration of the metal oxide is 30 vol %.

2. The fluorescent screen according to claim 1, wherein the thickness is in the range of m.

4. The metal oxide of the reflective layer is made of titanium oxide having a particle size of 0.15 to 0.4 μm.

2. The fluorescent screen according to claim 1 .

5. 2. The method according to claim 1, wherein the phosphor layer is composed of a phosphor powder and the transparent binder. Fluorescent plate on board.

6. A low refractive index layer having a refractive index lower than that of the phosphor layer is further provided on the phosphor layer. The fluorescent screen according to claim 1 .

7. The low refractive index layer contains particles having a refractive index lower than that of the transparent binder in an amount of 90 vol % or more.

7. The fluorescent screen according to claim 6, wherein the fluorescent screen comprises a coating film having a thickness of 50 to 200 nm.

8. 8. The fluorescent screen according to claim 7, wherein the low refractive index layer is an anti-reflection film that is a dielectric multilayer film.

9. 9. The fluorescent plate according to claim 1, wherein excitation light is incident on the phosphor layer. an excitation light source disposed at The excitation light from the excitation light source is condensed, and the fluorescent material layer is excited by the excitation light. A light source device comprising: a focusing optical system that focuses light.

10. The light source device according to claim 9 ; an illumination optical system that guides light emitted from the light source device to an image modulation element; Image generation by modulating incident light with the image modulation element based on an externally input image signal Department and a projection optical system that expands and projects the light modulated by the image generating unit, Image display device.

Images