JP2014229503A - Light-emitting device, method for manufacturing the same, and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device including a fluorescent material film with a large thickness even when using silicon oxide as a binder, and a method for manufacturing the same, in order to solve the problem that the fluorescent material film using the silicon oxide as the binder has a small thickness and hence is liable to cause absorption saturation, and reabsorption occurs when the fluorescent material is too dense, thus reducing conversion efficiency.SOLUTION: A fluorescent material layer includes a fluorescent material, potassium silicate, sodium silicate, and silica particles or a glass frit. A proportion of potassium silicate to sodium silicate is adjusted to satisfy both of printability in manufacturing and waterproofness after heat treatment.

Description

  The present invention relates to a light emitting element, a manufacturing method thereof, and a projector.

  Conventionally, in a projector, a discharge lamp such as an ultra-high pressure mercury lamp is generally used as a light source. However, this type of discharge lamp has problems such as relatively short life and difficulty in instantaneous lighting. In view of this, a projection-type image display apparatus using a light source instead of a discharge lamp has been proposed.

  As a light source of this type, a method of generating white light using fluorescent light emission is known. For example, a light source device that extracts white light as fluorescence by irradiating light from a light emitting diode (LED) or a laser light source to a phosphor has been proposed (Patent Document 1).

  A light source device described in Patent Document 1 includes an excitation light source that emits excitation light (blue light) that excites a phosphor, and a phosphor that emits red light and green light in a wavelength band different from the excitation light upon receiving the excitation light. And a phosphor wheel provided with a layer. FIG. 4 is a cross-sectional view of a green light emitting layer which is a conventional phosphor layer described in Patent Document 1.

  The green light emitting layer 11G is positioned on the support surface 77a on the support base 77. The lower part of the phosphor particles 55 is fixed to the support surface 77a by a binder 57. The upper part of the phosphor particles 55 is not covered with the binding material 57 and has a surface. Since the surface is exposed, the light extraction efficiency is increased.

JP 2012-185402 A

  However, in the conventional configuration, the binder of the phosphor particles is composed of silicate having a particle diameter smaller than that of the phosphor particles, and the thickness of the phosphor film is larger than the particle diameter of the phosphor particles. It is difficult to do. Due to the thin film thickness, the absolute amount of fluorescence emitted from the phosphor particles is smaller than the incident light, and as a result, a phenomenon in which a part of the incident light is reflected as it is is likely to occur.

  In addition, when the distance between the phosphor particles is close and the density of the phosphor particles per unit volume becomes high, the phenomenon that the fluorescence emitted from the phosphor particles is absorbed by the adjacent phosphor particles, that is, reabsorption tends to occur. . As a result, there is a problem that a desired conversion efficiency cannot be obtained.

  There is also a means in which the binder of the phosphor particles is a silicone resin. However, the heat resistance of the resin is low and the heat conductivity of the resin is low, so the heat dissipation is low, and generally the property that the efficiency of emitting fluorescence decreases as the temperature of the fluorescent material increases, so-called temperature quenching occurs. Therefore, there is a problem that a desired conversion efficiency cannot be obtained.

  SUMMARY An advantage of some aspects of the invention is to provide a light emitting element capable of suppressing a decrease in phosphor conversion efficiency, a method for manufacturing the light emitting element, and a projector including the light emitting element.

  In order to achieve the above object, a light-emitting element of the present invention includes a phosphor layer including a plurality of phosphor particles bonded by a binder, and a support substrate having a support surface that supports the phosphor layer. . The phosphor layer is characterized by being composed of phosphor, silicate and silica particles, or glass frit. Silica oxide is a base material made of a mixed solution of sodium silicate and potassium silicate, and the supporting base material is covered with an oxide film made of aluminum, silver or an inorganic material.

  With this configuration, it is possible to suppress a phenomenon in which a part of incident light is reflected as it is. In addition, the phenomenon that the fluorescence emitted from the phosphor particles is absorbed by the adjacent phosphor particles, that is, reabsorption can be suppressed. Moreover, since the silica particles and the silicate have a thermal conductivity approximately five times that of the resin, the heat conductivity is excellent, and as a result, the occurrence of temperature quenching can be suppressed. As a result, a decrease in phosphor conversion efficiency can be suppressed.

  The method for producing a light-emitting device of the present invention includes a step of disposing a liquid material containing a plurality of phosphor particles and silica particles having a similar refractive index of silicate and silicate or glass frit on a supporting substrate. By drying the liquid, the particles are bonded to each other by a dehydration condensation reaction between the plurality of phosphor particles and the silicate and silica particles or the glass frit on the support surface of the support substrate. And a step of applying heat at a temperature of about 100 to 250 ° C. The silicate is a mixed solution of sodium silicate and potassium silicate, and the supporting substrate is a substrate covered with an oxide film made of aluminum, silver or an inorganic material.

  As a means to place a liquid substance containing a plurality of phosphor particles and silica particles having the same refractive index of silicate and silicate, or glass frit on a support substrate, a printing method using a screen or by dispensing There are coating methods. According to this production method, a cured product of a plurality of phosphor particles, silicate and silica particles, or glass frit can be easily formed on the support substrate.

  As described above, a light-emitting element capable of suppressing a decrease in phosphor conversion efficiency can be realized by the light-emitting element of the present invention and the manufacturing method thereof. Furthermore, the manufacturing method and a projector provided with the light emitting element can be realized.

Diagram of light source device and projector in embodiment The perspective view of the fluorescent substance wheel with which the light source device in embodiment was equipped (A) Sectional view of phosphor wheel 10 in the embodiment, (B) Enlarged view of green light emitting layer 11G in FIG. The figure which shows the conventional light emitting layer described in patent document 1

  Embodiments of the present invention will be described below with reference to the drawings. The projector according to the present embodiment condenses light emitted from a light source on a micromirror display element called DMD (digital micro mirror device), and displays a color image on a screen, so-called one-chip DLP (digital・ This is an example of light processing.

  FIG. 1 is a schematic configuration diagram illustrating a light source device and a projector according to the present embodiment. FIG. 2 is a perspective view of a phosphor wheel (light emitting element) provided in the light source device according to the embodiment of the present invention. 3A is a cross-sectional view of the phosphor wheel, and FIG. 3B is an enlarged view of the green light emitting layer of FIG. 3A.

  In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.

As shown in FIG. 1, the projector 100 according to the present embodiment includes a light source device 120, a lighting device 130, a DMD 141, and a projection lens 110. In the projector 100 of the present embodiment, the light emitted from the light source device 120 is collected by the illumination device 130 and enters the DMD 141. The light reflected by the DMD 141 is enlarged and projected onto the screen by the projection lens 110, and the reference image light is modulated in a time-division manner to display a full-color projection image.
(Each component of the projector 100)
First, each component of the projector 100 will be described. The light source device 120 of this embodiment includes a laser light source 9, a heat sink 70, a phosphor wheel 10, a dichroic mirror 41, a collimator lens 20, mirrors 60, 61, 62, lenses 21, 22, 23, 24, 25, 26, 27, a motor 31, and a rotating shaft 32 are provided.

  The dichroic mirror 41 has a spectral characteristic that reflects blue light and transmits green light and red light.

  The laser light source 9 is provided with a heat sink 70. For example, blue laser light having a central wavelength of emission intensity of 450 nm is emitted as excitation light that excites phosphors included in the phosphor wheel 10 described later. The blue laser light emitted from the laser light source 9 is linearly polarized light whose polarization state is constant. In the present embodiment, the wavelength 450 nm corresponds to the first wavelength region.

  The laser light source 9 is shown as an example in which one laser light source 9 is used in FIG. 1, but a plurality of laser light sources 9 may be juxtaposed, for example. Further, the laser light source 9 that emits colored light having a central wavelength other than 450 nm may be used as long as it has a wavelength that can excite a phosphor to be described later. In this embodiment, the laser light source 9 is used, but a light emitting diode (LED) may be used as the solid light source.

FIG. 2 is a perspective view of phosphor wheel 10 provided in the light source device according to the embodiment of the present invention. The phosphor wheel 10 includes a green light emitting layer 11G, a red light emitting layer 11R, a blue light transmitting portion 12, a support base 77, and an increased reflection film 78. The blue light transmitting portion 12, the red light emitting layer 11R, and the green light emitting layer 11G are provided by being divided in the circumferential direction on the increased reflection film 78 of the support base 77 with excitation light.
(Phosphor wheel 10)
The phosphor wheel 10 of the present embodiment is a reflective phosphor wheel that generates fluorescence (wavelength conversion) when light is reflected. Therefore, in the present embodiment, the support base 77
A substrate having light reflectivity is used as (FIG. 2).

  Specifically, for example, a metal substrate such as aluminum or silver is preferably used from the viewpoint of high light reflectivity and excellent heat dissipation. In order to increase the light reflectance, the surface of the metal substrate is preferably mirror-polished. Alternatively, instead of a single metal substrate, a silver film formed on an aluminum substrate may be used.

  Further, on the support surface (front surface) of the support base 77, an increased reflection film 78 made of an oxide of an inorganic material such as a multilayer film of a silicon oxide film and a titanium oxide film is provided. Thereby, the light reflectance of the support base material 77 can be increased.

  As shown in FIG. 1, a motor 31 is connected to the center of the phosphor wheel 10, and is provided to be rotatable around a rotation shaft 32 that passes through the center of the phosphor wheel 10.

  The motor 31 rotates the phosphor wheel 10 at, for example, 7500 rpm when in use. As shown in FIG. 2, blue light LB is applied to the phosphor wheel 10 in which the blue light transmitting portion 12 divided in the circumferential direction, the red light emitting layer 11R, and the green light emitting layer 11G are formed in an annular shape having a diameter of about 45 mm. When incident, the region (beam spot) irradiated with the blue light LB on the phosphor wheel 10 is the surface of the blue light transmitting portion 12, the red light emitting layer 11R, and the green light emitting layer 11G divided in the circumferential direction. It moves about 18m / sec.

  That is, the motor 31 functions as a position displacement unit that displaces the position of the beam spot on the phosphor wheel 10. Thereby, since excitation light does not continue irradiating the same position on the fluorescent substance wheel 10, the thermal deterioration of the fluorescent substance particle of an irradiation position is prevented, and lifetime of an apparatus can be extended.

  In FIG. 1, the collimator lens 20 and the lens 21 are arranged on the optical path of the blue light LB emitted from the laser light source 9, and the reflective surface of the dichroic mirror 41 has an angle of 45 degrees with the phosphor wheel 10 beyond that. It is arranged to make. Since the dichroic mirror 41 has a characteristic of reflecting blue light and transmitting red light and green light, the blue light LB emitted from the laser light source 9 passes through the collimator lens 20 and the lens 21. Then, the light is reflected by the dichroic mirror 41, passes through the lens 27, and travels toward the phosphor wheel 10 having a plurality of light emitters.

  The blue light LB that has passed through the blue light transmitting portion 12 by the phosphor wheel 10 passes through the lens 26 and the lens 25 and is reflected by the mirror 62 at 90 degrees. Thereafter, similarly, the light is reflected 90 degrees by the dichroic mirror 41 through the lens 24 and the mirror 61, the lens 23, the mirror 60 and the lens 22, and irradiated to the illumination device 130.

The blue light LB that has entered the green light emitting layer 11G excites the phosphor particles of the green light emitting layer 11G, and is wavelength-converted into light having a central wavelength of emission intensity of, for example, 530 nm, and the green light LG is emitted. The blue light LB incident on the red light emitting layer 11R excites the phosphor particles of the red light emitting layer 11R, and is converted into light having a central wavelength of emission intensity of, for example, 680 nm, and the red light LR is emitted. The green light LG emitted from the green light emitting layer 11G and the red light LR emitted from the red light emitting layer 11R pass through the dichroic mirror 41 and are irradiated to the illumination device 130.
As illustrated in FIG. 1, the illumination device 130 includes a lens 131, a lens 132, a lens 133, and a rod integrator 134.

The blue light LB, the green light LG, and the red light LR incident on the lighting device 130 in a time-sharing manner are collected by the lens 131 and enter the rod integrator 134. The blue light, the green light, and the red light whose uniformity is improved by the rod integrator 134 are collected by the lens 132 and the lens 133 and enter the DMD 141 while being time-divided. The blue light LB, the green light LG, and the red light LR reflected by the DMD 141 generate a color image on the screen while being time-divided through the projection lens 110.
(Example)
The Example regarding the phosphor wheel 10 is shown. Hereinafter, the structure of the light emitting layer of the phosphor wheel 10 will be described by taking the green light emitting layer 11G of FIGS. 3A and 3B as an example. However, the red light emitting layer 11R also has the same configuration except for the type of phosphor particles. In addition, since the film thickness of the reflective reflection film 78 is as very thin as 1 micrometer or less, the heat dissipation of the support base material 77 is not prevented by interposing the reflective reflection film 78.

  In the case of the present embodiment, the green light emitting layer 11G is actually formed on the enhanced reflection film 78 made of an oxide of an inorganic material such as a multilayer film of a silicon oxide film and a titanium oxide film provided on the support base 77. Is provided. FIG. 3A is a cross-sectional view of the phosphor wheel 10 according to the embodiment of the present invention, and FIG. 3B is an enlarged cross-sectional view of the green light emitting layer 11G in FIG.

  The phosphor wheel 10 includes a support base 77 and a green light emitting layer 11G. As shown in FIGS. 3A and 3B, the green light emitting layer 11G includes a plurality of phosphor particles 55, a transparent material 56, and a binder 57.

  The phosphor particles 55 are particulate phosphors that absorb the excitation light emitted from the laser light source 9 and emit fluorescence. For example, the phosphor particle 55 includes a fluorescent material that emits fluorescence excited by blue light having a center wavelength of 450 nm, and includes a part of the green wavelength region of the excitation light emitted from the laser light source 9. It is converted into light having a distribution and emitted.

  At this time, the density of the phosphor particles 55 is small within the light irradiation range, the absolute amount of fluorescence converted by the phosphor particles with respect to the incident light is reduced, and as a result, a part of the incident light is reflected as it is. This phenomenon is likely to occur. Therefore, a sufficient density of the phosphor particles 55 is required within the light irradiation range.

  Further, when the plurality of phosphor particles 55 are in a very high density state, a phenomenon in which the fluorescence emitted from the phosphor particles 55 is absorbed by the nearby phosphor particles 55, that is, reabsorption is likely to occur.

  Therefore, the transparent material 56 is mixed in order to obtain an appropriate density of the phosphor particles within the light irradiation range. The transparent material 56 is suitably silica particles or glass frit. The transparent material 56 preferably has a particle diameter equal to or less than that of the phosphor particles 55, or the ratio of the phosphor particles 55 and the transparent material 56 per volume is in an appropriate state within the light irradiation range. It is desirable to be controlled.

  Further, a binder 57 is used as a component that becomes a binder between the phosphor particles 55 and the transparent material 56. By promoting the dehydration condensation reaction of the binder 57 using at least one of the phosphor particles 55 that are oxide particles and the transparent material 56 as a catalyst, Curing is performed. By this reaction, the phosphor particles 55, the transparent material 56, and the dehydrated binder 57 are cured in a dispersed state as shown in FIG.

  If a paste is made only with sodium silicate as the binding material 57, the curing time is fast, which causes a reduction in productivity. Moreover, if a paste is made only with potassium silicate as the binder 57, the water resistance after curing cannot be satisfied. Therefore, a suitable mixed material 57 is a mixed solution of sodium silicate and potassium silicate.

When the refractive index of the transparent material 56 and the binder 57 is set to the same level, scattering at the interface between the transparent material 56 and the binder 57 can be suppressed, and the transparency can be increased.
<Composition and physical properties>
A test was conducted to investigate the desirable composition and physical properties of the raw material used for forming the green light emitting layer 11G. In the test described below, the raw material of the green light emitting layer 11G is referred to as “paste” for convenience.
[Composition Confirmation Test 1 of Green Light-Emitting Layer Paste]
A paste containing the materials shown in Table 1 was used as a paste for the green light emitting layer 11G. Table 1 shows the composition and the evaluation results.
(1) Phosphor particles 55: YAG phosphor having a composition represented by (Y, Gd) 3Al5O12: Ce having an average particle size of about 10 to 20 μm (2) Transparent material 56: Silica particles, true spherical particles having an average particle size of 2 μm (3) Binder 57: (A) Sodium silicate: solution having a molar ratio of silicon dioxide to sodium oxide (SiO2 / Na2O) of about 2.5, (B) Potassium silicate: molar ratio of silicon dioxide to potassium oxide ( Aqueous solution whose SiO2 / K2O) is about 2

  If the average particle diameter of the silica particles of the transparent material 56 is small with respect to the phosphor particles 55, the transparency tends to increase, but if it is too small, the viscosity of the paste increases and printing becomes difficult. Therefore, the average particle diameter of the silica particles of the transparent material 56 is preferably about 0.2 μm to 10 μm, and preferably about 2 μm.

  The molar ratio of silicon dioxide and sodium oxide (SiO2 / Na2O) of sodium silicate affects the printability, and is preferably about 2 to 4, and preferably about 2.5. Moreover, since the molar ratio (SiO2 / K2O) of silicon dioxide and potassium oxide of potassium silicate similarly affects the printability and water resistance, it is preferably about 1 to 4, preferably about 2.

When adjusting the paste, stirring was performed twice at 1500 rpm for 3 minutes in a rotating / revolving vacuum mixer. The obtained paste was printed on an aluminum substrate by screen printing. Next, the paste was solidified by allowing to stand at room temperature for about 12 hours. Finally, baking was performed in a drying furnace at 150 ° C. for about 1 hour. Thereby, a green light emitting layer 11G having a thickness of about 300 μm was completed.
(Water resistance test)
Productivity was evaluated for these prepared pastes. Moreover, the water resistance test was done with respect to the produced board | substrate.

  As an evaluation of productivity, continuous printability was tested. The continuous printability is defined as “◯” when a paste is applied on a screen and normally 5 or more sheets can be continuously printed on the support substrate 77, and “×” is defined as less than 5 sheets.

In the water resistance test, a water droplet is dropped on the green light emitting layer 11G on the support base 77 and left standing for about 1 hour in a state covered with water, and when the green light emitting layer 11G does not change when moisture is removed thereafter. When “o” and elution of the green light emitting layer 11G into water were observed, “x” was assigned.
(productivity)
In Comparative Example 1 in which paste was formed only with sodium silicate without using potassium silicate as a solution component, curing started during printing and 5 or more continuous printing could not be performed. This is thought to be due to the progress of the dehydration condensation reaction of sodium silicate using the YAG phosphor as oxide particles and the silica particles as transparent material as catalysts. The molecular formula of sodium silicate having a molar ratio of 2.5 is represented by 2Na2O.5SiO2aq, and it is considered that a crosslinked product represented by the following chemical formula 1 was formed through a dehydration condensation reaction.

  When a water resistance test was performed after substrate baking at 150 ° C. for 1 hour, no elution into water by the green light emitting layer 11G was observed. As the meaning of performing substrate baking at 150 ° C. for 1 hour, it has the purpose of eliminating the hydroxyl group on the surface of the green light emitting layer 11G and improving water resistance, but for Comparative Example 1 cured only with sodium silicate as an aqueous solution component The effect of improving the water resistance was sufficient.

  In order to moderate the reactivity of sodium silicate, Comparative Example 2 in which paste was formed only with potassium silicate without using sodium silicate as an aqueous solution component was excellent in continuous printability and allowed to stand for about 12 hours after printing to solidify. I was able to. It is thought that this is because the dehydration condensation reaction of potassium silicate progressed using the YAG phosphor as oxide particles or the silica particles as transparent material as a catalyst.

  However, when a water resistance test was performed after substrate baking at 150 ° C. for 1 hour, elution into water by the green light emitting layer 11G was observed. As in Comparative Example 1, the purpose of baking the substrate at 150 ° C. for 1 hour is to eliminate the hydroxyl group on the surface of the green light emitting layer 11G and to improve water resistance, but the comparative example was cured only with potassium silicate. About 2, the effect of improving water resistance was insufficient.

  About Example 1 which paste-formed sodium silicate and potassium silicate by the ratio of the same quantity, continuous printability and the water resistance test were satisfied. The coagulation is thought to be due to the progress of the dehydration condensation reaction of potassium silicate using the YAG phosphor as oxide particles and the silica particles as transparent material as catalysts. Regarding water resistance, it is considered that the substrate baking at 150 ° C. for 1 hour can eliminate or reduce the hydroxyl groups on the surface of the green light emitting layer 11G, and as a result, the water resistance can be improved.

  In order to further improve the continuous printability, Example 2 was performed in which the weight ratio of sodium silicate to potassium silicate was 2: 8. In Example 2, the continuous printability and the water resistance test were satisfied. The coagulation is thought to be due to the progress of the dehydration condensation reaction of potassium silicate using the YAG phosphor as oxide particles and the silica particles as transparent material as catalysts. The continuous printability was improved from that in Example 1, and 10 or more continuous prints could be performed. Regarding water resistance, it is considered that the substrate baking at 150 ° C. for 1 hour can eliminate or reduce the hydroxyl groups on the surface of the green light emitting layer 11G, and as a result, the water resistance can be improved.

According to this configuration, the phosphor layer is composed of phosphor, sodium silicate, potassium silicate, and silica particles, and the support substrate 77 is covered with an oxide film made of aluminum, silver, or an inorganic material. Thus, a phosphor wheel satisfying the water resistance after curing and the continuous printability of the paste and a production method thereof can be obtained, and a phosphor wheel capable of suppressing a decrease in phosphor conversion efficiency and its production can be produced. . At this time, the ratio of sodium silicate and potassium silicate, which are solution components, can satisfy continuous printability and water resistance when sodium silicate is 50% to 20% (potassium silicate is 50% to 80%). Further, lithium silicate may be used instead of potassium silicate.
[Composition confirmation test 2 of paste for green light emitting layer]
A paste containing the materials shown in Table 2 was used as a paste for the green light emitting layer 11G. The difference from the composition confirmation test 1 of the green light emitting layer paste is that the transparent material 56 was silica particles in the composition confirmation test 1, but a glass frit was used in the composition confirmation test 2. Table 2 shows the composition and results of evaluation. Glass frit was used as the transparent material 56, and sodium silicate and potassium silicate were used as the binder 57.

(1) Phosphor particles 55: YAG phosphor having a composition represented by (Y, Gd) 3Al5O12: Ce having an average particle size of about 10 to 20 μm (2) Transparent material 56: Glass frit, amorphous particles having an average particle size of 8 μm (3) Binder 57: (1) Sodium silicate: aqueous solution having a molar ratio of silicon dioxide to sodium oxide (SiO2 / Na2O) of about 2.5, (2) Potassium silicate: molar ratio of silicon dioxide to potassium oxide ( Aqueous solution in which SiO2 / K2O) is about 2

  If the particle size of the glass frit, which is the transparent material 56, is small with respect to the phosphor particles 55, the transparency tends to increase, but if it is too small, the viscosity of the paste increases and printing becomes difficult. Therefore, the particle diameter of the silica particles of the transparent material 56 is preferably about 0.2 μm to 10 μm, and preferably about 2 to 8 μm. Glass frit is obtained by pulverizing oxide glass.

The molar ratio of silicon dioxide and sodium oxide (SiO2 / Na2O) of sodium silicate affects the printability, and is preferably about 2 to 4, and preferably about 2.5. Moreover, since the molar ratio (SiO2 / K2O) of silicon dioxide and potassium oxide of potassium silicate similarly affects the printability and water resistance, it is preferably about 1 to 4, preferably about 2.
For the preparation of the sample, the same processing as in the composition confirmation test 1 was performed, and the green light emitting layer 11G having a thickness of about 300 μm was completed.

  The productivity evaluation and water resistance test similar to the composition confirmation test 1 were performed on these pastes. The results are summarized in Table 2.

  Similar to the results of Composition Confirmation Test 1, for Comparative Example 1 in which paste was formed only with sodium silicate without using potassium silicate as a solution component, in the evaluation of productivity, curing started during printing and continuous printing was performed. Could not do more than one. When a water resistance test was performed after substrate baking at 150 ° C. for 1 hour, no elution into water by the green light emitting layer 11G was observed. About the comparative example 1 hardened only with sodium silicate as a solution component, the effect of improving water resistance was sufficient.

  In order to moderate the reactivity of sodium silicate, Comparative Example 2 in which paste was formed only with potassium silicate without using sodium silicate as a solution component is excellent in continuous printability, which is an evaluation of productivity. Although it was allowed to solidify by standing for 12 hours, when a water resistance test was conducted after baking the substrate at 150 ° C. for 1 hour, elution into water by the green light emitting layer 11G was observed. Although it is the same as that of the composition confirmation test 1, about the comparative example 2 hardened only with potassium silicate, the effect which improves water resistance was inadequate.

About Example 1 which paste-formed sodium silicate and potassium silicate by the ratio of the same quantity, productivity and water resistance were satisfied.
In order to further improve productivity, Example 2 was performed in which the weight ratio of sodium silicate to potassium silicate was 2: 8. About Example 2, productivity and water resistance were satisfied.

  According to this configuration, the phosphor layer is composed of phosphor, sodium silicate, potassium silicate, and glass frit, and the support base 77 is covered with an oxide film made of aluminum, silver, or an inorganic material. Thus, a phosphor wheel satisfying the water resistance after curing and the productivity of the wheel and a production method can be obtained, and a phosphor wheel capable of suppressing a decrease in the conversion efficiency of the phosphor and its production can be produced.

  At this time, the ratio of sodium silicate and potassium silicate, which are solution components, can satisfy continuous printability and water resistance when sodium silicate is 50% to 20% (potassium silicate is 50% to 80%). Further, lithium silicate may be used instead of potassium silicate.

  Since the projector finally obtained through the phosphor wheel and the manufacturing method of the present invention has good light utilization efficiency, it can be suitably used as a commercial projector and a projector for general homes, and other various display devices. Can also be suitably used.

  Further, the manufacturing method of the present invention is not limited to a projector, and can be used in other product fields. For example, in the field of LED lighting, it can also be applied to uses such as a transparent sealing material for optical components.

DESCRIPTION OF SYMBOLS 9 Laser light source 10 Phosphor wheel 11G Green light emitting layer 11R Red light emitting layer 12 Blue light transmission part 20 Collimator lens 21-27 Lens 31 Motor 32 Rotating shaft 41 Dichroic mirror 55 Phosphor particle 56 Transparent material 57 Binding material 60-62 Mirror 70 Heat Sink 77 Supporting Base 77a Supporting Surface 78 Increasing Reflective Film 100 Projector 110 Projection Lens 120 Light Source Device 130 Illumination Devices 131-133 Lens 134 Rod Integrator 141 DMD
LB Blue light LG Green light LR Red light

Claims (11)

A support substrate;
A plurality of phosphor particles disposed on the support substrate;
Transparent particles disposed between the plurality of phosphor particles;
A light emitting device comprising: a binder that joins the phosphor particles and the transparent particles. The light emitting device according to claim 1, wherein the binding material is a silicate. The light emitting device according to claim 1, wherein the transparent particles are silica particles or glass frit. 3. The light emitting device according to claim 2, wherein the silicate is a mixture of sodium silicate and potassium silicate. 5. The light-emitting element according to claim 4, wherein the sodium silicate is 50 wt% to 20 wt% and the potassium silicate is 50 wt% to 80 wt% when the silicate is 100 wt%. 6. The light emitting device according to claim 1, wherein an average particle diameter of the transparent particles is smaller than an average particle diameter of the phosphor particles. The light-emitting element according to claim 1, wherein the support base is aluminum or a base coated with an oxide film. A light source device composed of a light source that emits light of a first wavelength band and a phosphor device that is an excitation optical element that is excited by the light source and emits light of another wavelength;
A lighting device for guiding light from the light source device to a light modulation element;
A projection optical system that projects image light modulated by the light modulation element in accordance with an input image signal onto a screen,
The projector according to claim 1, wherein the phosphor device of the light source device is the light emitting element according to claim 1. Disposing a liquid material containing a plurality of phosphor particles, siliceous oxide, silica particles or glass frit on a support substrate;
By heat-treating the liquid, the particles are bonded to each other by a dehydration reaction between the plurality of phosphor particles, the silicate, and the silica particles or the glass frit on the support surface of the support substrate. And a process for producing the light emitting device. The method for manufacturing a light emitting device according to claim 9, wherein the silicate is a mixture of sodium silicate and potassium silicate. 10. The method of manufacturing a light emitting element according to claim 9, wherein when the silicate is 100 wt%, the sodium silicate is 50 wt% to 20 wt% and the potassium silicate is 50 wt% to 80 wt%.

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