JP6871423B2 - Color wheel and projector - Google Patents

Description

The present disclosure relates to a color wheel and a projector equipped with the color wheel.

Conventionally, a projector using a color wheel is known. A colored portion made of a phosphor or the like is provided on one main surface of the color wheel, and this colored portion converts the light emitted from the light source (light of the light source) into light of another wavelength (converted light). During wavelength conversion, part of the energy of the irradiated light becomes heat. Therefore, the surface of the color wheel provided with the colored portion has a higher temperature than the opposite surface, and the color wheel is deformed (thermally deformed) by thermal expansion.

In FIG. 8 of Patent Document 1, a wavelength conversion layer (colored portion) and a reflection layer are provided on the front surface of the main body made of a transparent non-metallic material, and a heat radiation adhesive layer is provided at a position corresponding to the position of the wavelength conversion layer on the rear surface. A color wheel having a heat dissipation sheet made of metal and graphite is described.

FIGS. 7 and 8 of Patent Document 2 include a first glass layer provided on the first main surface of the phosphor layer and a second glass layer provided on the second main surface. , In a color wheel in which a reflective layer made of metal is provided on the first glass layer, it is described that the heat generated in the phosphor layer is released to the outside through the reflective layer.

There are two types of color wheels: a transmission type that emits converted light to a surface opposite to the light irradiation surface of the light source, and a reflection type that emits conversion light to a surface on the same side as the light irradiation surface of the light source. Patent Documents 1 and 2 are configurations for a reflective color wheel. For example, the visible light transmittance of the sapphire color wheel body is about 98%, whereas the visible light reflectance of the aluminum reflective film used for the reflective color wheel is about 90%, so that it is a transmissive type. The color wheel has the advantage of less light loss (power saving) than the reflective color wheel. Since the light of the light source can be emitted perpendicularly to the color wheel, the optical path is short and a compact projector can be constructed.

Japanese Unexamined Patent Publication No. 2017-11418 Japanese Unexamined Patent Publication No. 2015-143824

The color wheel of the present disclosure includes a first surface, a second surface facing the first surface, and an outer peripheral surface connecting the first surface and the second surface, and is a transparent substrate having a center of rotation. A colored portion that is arranged on the first surface and converts the excitation light emitted from the light source into conversion light having a different wavelength, and the excitation light and the conversion light of at least one of the first surface or the second surface. The region outside the optical path is provided with a heat radiating portion which is arranged on the outer peripheral surface or the inner peripheral surface side of the substrate with respect to the colored portion and has a higher thermal conductivity than the substrate.

The projector of the present disclosure includes the color wheel.

The schematic top view which shows one Embodiment of the color wheel of this disclosure. FIG. 1A is a cross-sectional view taken along the line AA of FIG. 1A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. FIG. 2 is a cross-sectional view taken along the line BB'of FIG. 2A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. It is a cross-sectional view taken along the line CC'of FIG. 3A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. FIG. 4A is a cross-sectional view taken along the line DD'of FIG. 4A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. 5A is a cross-sectional view taken along the line EE'of FIG. 5A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. FIG. 6 is a cross-sectional view taken along the line FF'of FIG. 6A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. FIG. 7A is a cross-sectional view taken along the line GG'of FIG. 7A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. FIG. 8 is a cross-sectional view taken along the line HH'of FIG. 8A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. 9A is a cross-sectional view taken along the line I-I'in FIG. 9A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. FIG. 10A is a cross-sectional view taken along the line JJ'of FIG. 10A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. 11A is a cross-sectional view taken along the line KK'of FIG. 11A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. 12A is a cross-sectional view taken along the line LL'of FIG. 12A. The schematic top view which shows the other embodiment of the color wheel of this disclosure. 13A is a cross-sectional view taken along the line MM'of FIG. 13A. Top view of a schematic view showing another embodiment of the color wheel of the present disclosure. FIG. 14A is a cross-sectional view taken along the line NN'of FIG. 14A. It is a cross-sectional SEM photograph which shows an example of the color wheel of this disclosure. Schematic top view showing a conventional color wheel. FIG. 16A is a cross-sectional view taken along the line XX'of FIG. 16A.

<Color wheel and projector>
The color wheel 1 and the projector of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic view showing an embodiment of the color wheel 1. 2 to 14 are schematic views showing another embodiment of the color wheel 1. FIG. 15 is a cross-sectional SEM photograph of the color wheel 1. FIG. 16 is a schematic view showing a conventional color wheel 20.

As shown in FIG. 1, the color wheel 1 includes a first surface 2a, a second surface 2b facing the first surface 2a, and an inner peripheral surface 2c connecting the first surface 2a and the second surface 2b. A transparent substrate 2 having an outer peripheral surface 2d and a colored portion 3 (red colored portion 3R, green colored portion 3G) arranged on the first surface 2a side of the substrate 2 for converting excitation light into conversion light having different wavelengths. And, it is arranged on the inner peripheral surface 2c side of the colored portion 3 in the region outside the optical path of at least one of the excitation light and the conversion light of the first surface 2a or the second surface 2b, and has a higher thermal conductivity than the substrate 2. It is provided with a large heat radiating unit 4. The color wheel 1 is used by rotating it around a rotation center 1c.

The projector (not shown) of the present disclosure includes a light source that irradiates the color wheel 1 with light, a rotation holding unit that holds and rotates the color wheel 1, and a digital mirror device having a large number of micromirrors.

The color wheel 1 is thermally deformed by the heat generated from the colored portion 3 generated by the irradiation light. Since the color wheel 1 is used by rotating at a high speed, the number of rotations changes when it is thermally deformed. If the color wheel 1 has a large thermal deformation, it may be damaged due to centrifugal force or contact with other members.

The heat of the heat radiating unit 4 is radiated to the surrounding air as the color wheel 1 rotates. The color wheel 1 has a larger linear velocity during rotation and a larger area toward the outer peripheral surface 2d side. Since the color wheel 1 is provided with the heat radiating portion 4 on the outer peripheral surface 2d side of the colored portion 3, the amount of heat radiated into the air can be increased.

Since the color wheel 1 has the above configuration, it is excellent in heat resistance, heat dissipation, and rigidity, and is not easily deformed by heat. In particular, it is suitable for a transmissive color wheel 1 that emits converted light to a surface opposite to the irradiation surface of the light of the light source. The color wheel 1 can form a highly reliable projector. Further, the color wheel 1 can be combined with a high-power light source to form a high-brightness projector.

The thermal conductivity of the substrate 2 and the heat radiating unit 4 can be measured by using, for example, a laser flash method.

The substrate 2 has a disk shape, a diameter of 10 mm to 200 mm, and a thickness of 0.1 mm to 2.0 mm.

The substrate 2 is made of, for example, sapphire. Sapphire has excellent thermal conductivity and heat dissipation, and can suppress temperature rise, has high rigidity and is hard to deform, has strong mechanical strength and is relatively strong and hard to break, and has high light transmission. Excellent as 2. The substrate 2 may have a disk shape that does not have an inner peripheral surface 2c.

The colored portion 3 is made of, for example, a fluorescent substance. The color wheel 1 shown in FIG. 1 has a red colored portion 3R and a green colored portion 3G as the colored portion 3. A blue laser or the like is used as the light source used for such a color wheel 1. The red-colored portion 3R and the green-colored portion 3G convert the irradiation light (blue) into red light and green light, and are formed in an annular fan-shaped region having a predetermined central angle (for example, 120 °), respectively.

The main component of the heat radiating unit 4 is, for example, a metal having excellent thermal conductivity such as silver, copper, gold, and aluminum. The thickness of the heat radiating portion 4 is, for example, 10 μm to 1 mm, preferably 50 μm to 200 μm. When the heat radiating portion 4 is a metallized layer including a metal portion and a plurality of glass portions, the substrate 2 and the metal portion are firmly fixed by the glass portion existing near the interface between the heat radiating portion 4 and the substrate 2. .. When the heat radiating portion 4 includes the glass portion, the rigidity is higher than that of the metal alone. Therefore, the thermal deformation of the color wheel 1 can be reduced. The glass portion is, for example, glass containing silicon oxide as a main component. It is particularly preferable that the area ratio of the glass portion (hereinafter referred to as the glass ratio) of the heat radiating portion 4 in the cross section perpendicular to the first surface 2a or the second surface 2b is 10% or less.

The heat radiating unit 4 has a first region 4a including a surface in contact with the substrate 2 in a cross-sectional view perpendicular to the first surface 2a or the second surface 2b, and a second region 4b including a surface opposite to the substrate 2. .. When the glass ratio of the first region 4a is larger than the glass ratio of the second region 4b, the first region 4a having a large glass ratio increases the adhesion to the substrate 2, and the second region 4b having a small glass ratio causes the first region 4a to adhere to the substrate 2. The heat dissipation performance of the entire heat radiation unit 4 is increased.

The heat radiating unit 4 may further have a plurality of pores. The pores have a function of relaxing the thermal stress and residual stress of the heat radiating portion and suppressing deformation and breakage. However, if the pores are too large or the porosity is too large, the heat dissipation performance will deteriorate. Therefore, it is preferable that L / D, which is the ratio of the average distance between the centers of gravity of the pores L and the average circle equivalent diameter D, is 4 or more. When L / D is 4 or more, both stress relaxation and heat dissipation performance can be achieved at the same time.

FIG. 15 shows a cross-sectional SEM photograph (reflected electron image) of the color wheel 1. In the figure, in the heat radiating portion 4, the whitest portion is a metal portion, the black portion is a pore, and the intermediate brightness portion between the two is a glass portion. There are a plurality of pores and a plurality of glass portions. The glass ratio, the distance between the centers of gravity, and the equivalent diameter of the circle can be obtained from such a cross-sectional SEM photograph using image analysis software. For example, using the image analysis software "A image-kun" (registered trademark, manufactured by Asahi Kasei Engineering Co., Ltd.), the setting conditions are bright, small figure removal area of 0.1 μm ² , and noise removal filter. The threshold value, which is an index indicating the brightness of the light and darkness, can be obtained by adjusting so that the marker appearing on the screen matches the shape of the particles. In FIG. 15, the glass ratio of the first region 4a is 12.0%, the glass ratio of the second region is 4.9%, and the glass ratio of the entire heat radiating portion 4 is 8.0%. The average distance L between the centers of gravity of the pores is 7.7 μm, the average equivalent circle diameter D of the pores is 1.4 μm, and the L / D is 5.5.

In the color wheel 1, the temperature of the first surface 1a (corresponding to the first surface 2a of the substrate 2) having the colored portion 3 which is the heat generation source is higher than that of the second surface 1b (corresponding to the second surface 2b of the substrate 2). Prone. When the color wheel 1 is provided with the heat radiating portion 4 on the first surface 2a side of the substrate 2, the heat generated by the colored portion 3 can be quickly transmitted to the heat radiating portion 4. Therefore, it is often the case that the colored portion 3 and the heat radiating portion 4 are close to each other, and it is particularly preferable that they are in direct contact with each other.

As shown in FIGS. 2 and 3, if the color wheel 1 is also provided with the heat radiating portion 4 on the second surface 1b side, the heat radiating on the first surface 1b side is also large, which is preferable. In particular, if the heat radiating portion 4 is provided so as to face both the first surface 1a side and the first surface 1b side, the deformation of the color wheel 1 after the formation of the radiating portion 4 is small as described later, which is preferable. Is.

When the color wheel 1 is provided with the heat radiating portion 4 on the rotation center 1c side of the colored portion 3 as shown in FIGS. 4 and 5, the heat of the colored portion 3 is radiated to the rotation holding portion by heat conduction. Therefore, heat dissipation performance is improved. As shown in FIG. 6, it is particularly preferable that the heat radiating portion 4 for connecting the first surface 2a side and the second surface 2b side of the substrate 2 is provided.

As shown in FIG. 7, the color wheel 1 includes a heat radiating portion 41 having a thermal conductivity higher than that of the substrate 2 on the first surface 2a near the outer peripheral surface 2d of the colored portion 3. The heat radiating unit 41 may be located outside the optical path region of the excitation light. A plurality of heat radiating portions 41 may be arranged at intervals, or may be an annular integrated body.

As shown in FIGS. 8 and 9, the color wheel 1 may be provided with a heat radiating portion 41 on the second surface 2b side. As described above, when the heat radiating portion 41 is also provided on the second surface 2b side, the heat radiating performance is improved on the second surface 2b side as well. Therefore, the color wheel 1 is less likely to be thermally deformed. In particular, in the plan perspective of the first surface 2a, when the heat radiating portion 41 located on the first surface 2a and the radiating portion 41 located on the second surface 2b side overlap, the rotation due to the difference in the position of the radiating portion 41 There are few obstacles and deformations.

Further, as shown in FIGS. 10 and 11, the color wheel 1 may include a heat radiating portion 42 closer to the rotation center 1c of the substrate 2 than the coloring portion 3. When such a configuration is satisfied, the heat generated at the time of wavelength conversion can be dissipated also on the center side of the substrate 2, so that it is difficult to be thermally deformed.

When the substrate 2 has the inner peripheral surface 2c, heat can be dissipated to the rotation holding portion that holds the color wheel 1 by heat conduction, so that the heat dissipation performance is improved. Further, as a configuration for improving the heat dissipation performance, as shown in FIG. 9, the heat dissipation unit 41 may be provided from the first surface 2a to the second surface 2b of the substrate 2. The heat radiating unit 41 and the heat radiating unit 42 are the same as the heat radiating unit 4 described above.

The color wheel 1 shown in FIG. 12 includes a heat radiating portion 4 having a thermal conductivity higher than that of the substrate 2 outside the optical path region on the second surface 2b.

Since the color wheel 1 shown in FIG. 12 includes a heat radiating portion 4 having a thermal conductivity higher than that of the substrate 2 outside the optical path region on the second surface 2b, the thickness direction of the substrate 2, that is, the first surface 2a to the second surface 2a to the second. Heat transfer to the surface 2b is promoted, and heat dissipation by the heat radiating unit 4 causes less thermal deformation.

The heat generated during wavelength conversion is dissipated to the surrounding air as the color wheel 1 rotates. The color wheel 1 has a larger linear velocity during rotation and a larger area toward the outer peripheral surface 2d side. When the color wheel 1 is provided with the heat radiating portion 4 on the outer peripheral surface 2d side in the region outside the optical path as shown in FIGS. 12 and 14, the amount of heat radiated into the air can be increased. Therefore, the heat dissipation performance is improved, and the color wheel 1 is less likely to be thermally deformed.

As shown in FIGS. 13 and 14, the color wheel 1 may include the heat radiating portion 4 near the center 1c of the substrate 2 in the region outside the optical path. When such a configuration is satisfied, thermal deformation on the center side of the substrate 2 is reduced. In the color wheel 1, the first surface 2a provided with the coloring portion 3 becomes hotter than the second surface 2b at the time of wavelength conversion, and the first surface 2a undergoes thermal deformation so as to be convex, but outside the optical path. By providing the heat radiating portion 4 near the center of the substrate 2 in the region, heat tends to escape to the second surface 2b side. Therefore, the first surface 2a is suppressed from being thermally deformed to be convex.

When the first surface 2a of the color wheel 1 becomes hotter than the second surface 2b at the time of wavelength deformation, the substrate 2 undergoes thermal deformation in the direction in which the first surface 2a becomes convex. The substrate 2 may have a concave shape when the first surface 2a including the colored portion 3 is not wavelength-converted. When the residual stress of the color wheel 1 has a stress that cancels the thermal stress due to the heat generated by the colored portion 3, or when it is in a range larger than the thermal stress due to the heat generated by the colored portion 3, deformation is suppressed, which is preferable. Is.

Specifically, when the heat radiating portion 4 is formed by a method such as firing that is higher than room temperature, the substrate 2 and the heat radiating portion are formed due to the temperature difference between the formation temperature and the room temperature and the difference in the coefficient of thermal expansion between the substrate 2 and the heat radiating portion 4. Residual stress is generated in 4. In general, since metal has a large coefficient of thermal expansion, the substrate 2 is deformed so that the surface on the side where the heat radiating portion 4 is formed becomes a compressive stress and the surface on the side where the heat radiating portion 4 is formed becomes concave.

When the color wheel 1 is provided with the heat radiating portion 4 formed at a high temperature on the first surface 2a side, the first surface 2a becomes concave, and the thermal deformation of the first surface 2a into a convex shape at the time of wavelength conversion is suppressed. The wheel. It is presumed that this is because the residual stress of the first surface 2a and the thermal stress at the time of wavelength conversion cancel each other out.

When the color wheel 1 is provided with the heat radiating portion 4 on both the first surface 1a and the second surface 1b, the residual stress due to the formation of the heat radiating portion 4 is canceled out, and the color wheel 1 after the formation of the heat radiating portion 4 is formed. It is suitable because the deformation is small. In particular, in the plan perspective of the first surface 2a, if the heat radiating portions 4 located on the first surface 2a and the second surface 2b are arranged so as to overlap each other, the deformation of the substrate 2 at the time of forming the heat radiating portion 4 can be suppressed. Can be done. By appropriately designing the design (position, area, thickness, etc.) of the heat radiating portion 4 of the first surface 1a and the second surface 1b according to the usage conditions (heating conditions) of the color wheel 1, the color wheel 1 can be further subjected to. Deformation can be suppressed.

The light source of the projector may be arranged on the first surface 1a side or the second surface 1b side of the color wheel 1. When the conversion light of the color wheel 1 from the coloring portion 3 is emitted to the first surface 1a side (in the case of a transmissive projector, the light source is arranged on the second surface 1b side), the conversion light is transmitted to the substrate. This is particularly preferable because the amount of light is not attenuated by passing through 2. When the colored portion 3 and the heat radiating portion 4 are in direct contact with each other, if the overlapping portion between the colored portion 3 and the heat radiating portion 4 is laminated so that the heat radiating portion 4 is on the light source side, the heat of the colored portion 3 is generated. It is suitable because it is quickly transmitted to the heat radiating unit 4.

<Manufacturing method of color wheel>
The manufacturing method of the color wheel 1 of this embodiment will be described.

First, a sapphire plate as a material for the substrate 2 is prepared. The sapphire plate is formed by cutting and processing a sapphire ingot grown using polycrystalline alumina as a raw material. The sapphire plate has, for example, a disk shape having a diameter of 10 mm to 200 mm and a thickness of 0.1 mm to 2.0 mm.

There are no particular restrictions on how to grow sapphire ingots. A sapphire ingot grown by the EFG (Edge-defined film-fed Growth) method, CZ (Czochralski method), Cairo Porous method, or the like can be used.

Then, a fixing hole or the like for fixing the substrate 2 to the rotation holding portion is formed on the sapphire plate.

Subsequently, the sapphire plate is processed by a wrapping device so that the arithmetic average roughness Ra of both main surfaces of the sapphire plate is 1.0 μm or less. Wrapping may be performed in the self-weight mode using, for example, a cast iron surface plate and diamond abrasive grains having an average particle size of 25 μm.

The arithmetic mean roughness Ra in the present specification is a value based on JIS B0601 (2013). The arithmetic mean roughness Ra can be measured using, for example, a laser microscope apparatus VK-9510 manufactured by KEYENCE CORPORATION. The measurement conditions are, for example, the measurement mode is color ultra-depth, the measurement magnification is 1000 times, the measurement pitch is 0.02 μm, the cutoff filter λs is 2.5 μm, the cutoff filter λc is 0.08 mm, and the measurement length is 100 μm. It is preferable to set it to 500 μm.

After wrapping, heat treatment may be performed to reduce residual stress and crystal defects on the surface and inside of the sapphire plate, or to improve the light transmittance. Specific conditions for the heat treatment include holding the sapphire plate in an inert gas atmosphere such as argon or in a vacuum at a temperature of 1800 ° C. or higher and 2000 ° C. or lower for 5 hours or longer, and then lowering the temperature to room temperature for 6 hours or longer. Cool to. As a result, the rearrangement of atoms progresses on the surface and inside of the sapphire substrate, crystal defects and internal stresses are reduced, and the light transmittance is improved.

Subsequently, CMP (Chemical Mechanical Polishing) using colloidal silica is performed, and both main surfaces of the sapphire plate are mirror-polished so that the arithmetic average roughness Ra is 30 nm or less, preferably 1 nm or less. Can be manufactured.

Then, a phosphor or a color filter to be the coloring portion 3 is formed on a desired region of the first surface 2a of the substrate 2 by a method such as vapor deposition, coating, or firing.

Further, of the first surface 2a or the second surface 2b of the substrate 2, the region outside the optical path of the excitation light and the conversion light in the desired region of at least one surface (at least the region on the outer peripheral surface 2d side of the colored portion 3). Including), a heat radiating portion 4 made of silver, copper, gold, aluminum, or the like is formed by a method such as vapor deposition, coating, or firing. The heat radiating portion 4 may be formed by applying and firing a composition containing a metal powder and a glass powder.

When the heat radiating portion 4 is formed at a high temperature, residual stress is generated in the substrate 2 and the heat radiating portion 4. When the formation temperature of the heat radiating portion 4 is 600 ° C. or higher, the residual stress is relatively large as compared with the thermal stress due to the heat generated by the colored portion 3, and the deformation of the color wheel 1 is suppressed, which is preferable.

As described above, in the method for manufacturing the color wheel 1 of the present disclosure, the first surface 2a, the second surface 2b facing the first surface 2a, and the inner peripheral surface 2c connecting the first surface 2a and the second surface 2b are connected. A step of preparing a transparent substrate 2 having an outer peripheral surface 2d and a step of forming a colored portion 3 on the first surface 2a that converts excitation light emitted from a light source into conversion light having a different wavelength, and a first step. A heat radiating portion 4 having a thermal conductivity higher than that of the substrate 2 is formed in a region on the outer peripheral surface 2d side of the colored portion 3 in a region outside the optical path of at least one of the excitation light and the conversion light of the surface 2a or the second surface 2b. It is provided with a process to be performed. Therefore, it is possible to provide a color wheel that is not easily deformed by heat.

Either the coloring portion 3 or the heat radiating portion 4 may be formed first. It is preferable to form the colored portion 3 before or at the same time as the heat radiating portion 4 because the residual stress generated by the formation of the heat radiating portion 4 does not change. If the heat radiating portion 4 is formed before the coloring portion 3, the coloring portion 3 is not damaged by heat when the heat radiating portion 4 is fired, and the degree of freedom in firing conditions of the heat radiating portion 4 is improved, which is preferable.

According to such a color wheel, it can be applied to a transmissive color wheel in which the converted light propagates to the opposite side of the light source. Therefore, it is possible to provide a color wheel that is not easily deformed by heat and a highly reliable projector equipped with this color wheel.

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various improvements and changes may be made within the scope of the claims. For example, the color wheel 1 may be provided with an antireflection film for reducing the reflection of the light of the light source on the surface on which the light of the light source is incident, or is converted to the side opposite to the conversion light emitting side of the coloring portion 3. A dichroic film that reflects light and transmits light from a light source may be provided.

(Example 1)
Two sapphire substrates having a diameter of 100 mm and a thickness of 1 mm are prepared, and as Example 1, a colored portion 3 and a heat radiating portion 4 are provided on a first surface 2a (1a) as shown in FIG. Made a color wheel 1 located on the inner peripheral surface 2c side of the colored portion 3.

(Example 2)
Two sapphire substrates having a diameter of 100 mm and a thickness of 1 mm are prepared, and as Example 2, a collar having a heat radiating portion 41 closer to the outer peripheral surface 2d than the colored portion 3 on the first surface 2a as shown in FIG. Wheel 1 was created.

(Example 3)
Two sapphire substrates having a diameter of 100 mm and a thickness of 1 mm are prepared, and as Example 2, a collar having a heat radiating portion 4 closer to the outer peripheral surface 2d than the colored portion 3 on the second surface 2b as shown in FIG. Wheel 1 was created.

As a comparative example, as shown in FIG. 16, a color wheel 20 having a colored portion on the first surface 20a and no heat radiating portion 4 was manufactured. In the example, a paste containing silver particles and silica-based glass was applied and fired at a firing temperature of 800 ° C. to form a heat radiating portion 4 having a thickness of about 50 μm.

A ring-shaped sapphire having an outer diameter of 80 mm, an inner diameter of 70 mm, and a thickness of 10 mm for heating the colored portion 3 of the color wheels 1 of Examples 1 to 3 and the color wheel 20 of the comparative example with the colored portion 3 facing down. The heat dissipation performance was compared by placing it on a hot plate heated to 160 ° C. and heating it for 10 minutes and measuring the warpage before and after heating. To measure the warp, a lever gauge manufactured by Mitutoyo Co., Ltd. was used on the hot plate to measure the change in height from the hot plate on the outermost periphery of the color wheel 1 (20) before and after heating. In each of the examples and the comparative examples, the measurement was repeated three times, and the average value was taken as the value of the warp change.

In Examples 1 and 2, the change in warpage before and after heating was 5 μm. In Example 3, the change in warpage before and after heating was 0 μm. In the comparative example, the change in warpage before and after heating was 20 μm.

1, 20: Color wheel 1a: First surface 1b: Second surface 1c: Rotation center 2: Substrate 2a: First surface 2b: Second surface 2c: Inner peripheral surface 2d: Outer peripheral surface 3: Colored portion 3R: Red coloring Part 3G: Green colored part 4: Heat dissipation part 41, 42: Heat dissipation part 4a: First region 4b: Second region

Claims (15)

A transparent substrate having a first surface, a second surface facing the first surface, an outer peripheral surface and an inner peripheral surface connecting the first surface and the second surface, and having a rotation center.
A colored portion arranged on the first surface and converting the excitation light emitted from the light source into conversion light having a different wavelength,
The region outside the optical path of the excitation light and the conversion light of at least one of the first surface or the second surface is arranged on the outer peripheral surface or the inner peripheral surface side of the substrate with respect to the colored portion, and is arranged from the substrate. Also equipped with a heat dissipation part with high thermal conductivity,
Wherein the heat radiating portion from the first surface to said second surface that are disposed in succession, the color wheel. A transparent substrate having a first surface, a second surface facing the first surface, an outer peripheral surface and an inner peripheral surface connecting the first surface and the second surface, and having a rotation center.
A colored portion arranged on the first surface and converting the excitation light emitted from the light source into conversion light having a different wavelength,
The region outside the optical path of the excitation light and the conversion light of at least one of the first surface or the second surface is arranged on the outer peripheral surface or the inner peripheral surface side of the substrate with respect to the colored portion, and is arranged from the substrate. Also equipped with a heat dissipation part with high thermal conductivity,
The heat radiating portion is a color wheel including a metal portion and a glass portion. The color wheel according to claim 1 or 2 , wherein the heat radiating portion is arranged on the outer peripheral surface side of the colored portion. The color wheel according to any one of claims 1 to 3 , wherein the heat radiating portion is provided on at least the first surface. The color wheel according to any one of claims 1 to 3 , further comprising the heat radiating portion on the first surface and the second surface. The color wheel according to any one of claims 3 to 5, wherein the heat radiating portion is provided on the rotation center side of the substrate with respect to the colored portion on the first surface. The color wheel according to any one of claims 1 to 3 , further comprising the heat radiating portion on the second surface. The color wheel according to any one of claims 1 to 7 , wherein the substrate is made of sapphire. The heat radiating portion has a first region including a surface in contact with the substrate and a second region including a surface opposite to the substrate in a cross-sectional view perpendicular to the first surface or the second surface. the area ratio of the glass portion of the first region is larger than the ratio of the glass portion of the second region, the color wheel according to claim 2. The color wheel according to claim 9 , wherein the area ratio of the glass portion in the cross section of the heat radiating portion is 10% or less. The color wheel according to any one of claims 1 to 10 , wherein the heat radiating portion has a plurality of pores, and the ratio L / D of the average distance between the centers of gravity L and the average circle equivalent diameter D of the pores is 4 or more. .. The color wheel according to claim 5 , wherein the heat radiating portion located on the first surface side and the radiating portion located on the second surface side overlap each other in a plane perspective from the first surface side. The color wheel according to claim 1 or 2 , wherein the heat radiating portion and the coloring portion on the same surface of the substrate are in direct contact with each other. The color wheel according to claim 13 , wherein the overlapping portion of the colored portion and the heat radiating portion is laminated so that the heat radiating portion is on the light source side. A projector comprising the color wheel according to any one of claims 1 to 14.

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