JP6459634B2 - Light source device and projector provided with light source device - Google Patents

Description

  The present invention relates to a light source device and a projector including the light source device.

  2. Description of the Related Art In recent years, time division projectors that take out light of a plurality of wavelengths in a time division manner and form and project an image by sequentially modulating the extracted light of the plurality of wavelengths have become widespread. As a light source device used for such a time-division projector, for example, a light source that outputs white light and a rotating wheel to which a plurality of color filters are attached are used to convert white light emitted from the light source at a constant speed. The light is made incident on a rotating wheel that rotates in order to extract light of a plurality of wavelengths (for example, blue, green, and red light) in a time-sharing manner.

  In recent years, a light source that outputs a single wavelength light such as a semiconductor laser is used instead of a conventional white light source. For example, a rotating wheel (phosphor wheel) having a phosphor instead of a color filter is used. In addition, a light source device that takes out light of a plurality of wavelengths in a time-division manner by making single-wavelength light emitted from a light source such as a semiconductor laser incident thereon has also become widespread. Among such light source devices, a phosphor wheel that transmits light, which has two substrates in the light traveling direction, and emits light of the same color on both substrates (for example, a red phosphor) (2) has been proposed (see Patent Document 1).

JP2012-159585A

The light source device disclosed in Patent Document 1 has two substrates, and phosphors that emit light of the same color are provided on both substrates. Therefore, a phosphor film provided on one substrate is assumed. Even if there is a limit to the thickness, the overall film thickness can be increased, so that the light use efficiency from the light source can be increased.
However, in the phosphor wheel described in Patent Document 1, the heat generated in each phosphor at the time of wavelength conversion is only cooled by using the respective substrates, and thus cannot be sufficiently cooled. In such a phosphor that is susceptible to the influence of heat whose wavelength conversion efficiency decreases as the temperature rises, there is a possibility that sufficient performance cannot be exhibited.

  In order to solve the above-described problems, one of the light source devices according to the embodiments of the present invention transmits a light source, light from the light source, and sequentially includes a first substrate and a second substrate from the light source side. A phosphor wheel, and the phosphor wheel includes a first phosphor disposed between the first substrate and the second substrate, and a second phosphor. The first phosphor and the second phosphor are arranged at different positions in the rotation direction of the phosphor wheel, and the first phosphor is composed of the first substrate and the second substrate. The second phosphor is in contact with the second substrate.

  One projector according to an embodiment of the present invention forms an image by sequentially modulating light of a plurality of wavelength bands emitted from the light source device based on the light source device of the above embodiment and image data. Light modulation means and projection means for enlarging and projecting the image.

  As described above, in the embodiment of the present invention, a light source device that is less affected by the heat generation of the phosphor and that can suppress a decrease in light emission efficiency is provided. As a result, a high performance using the light source device is provided. A projector can be provided.

It is a side view showing typically the light source device concerning one embodiment of the present invention. It is a schematic diagram which shows each surface of the phosphor wheel which concerns on one embodiment of this invention. It is a side view which shows typically the light source device which concerns on other embodiment (the 1) of this invention. It is a side view which shows typically the light source device which concerns on other embodiment (the 2) of this invention. It is a schematic diagram which shows each surface of the phosphor wheel which concerns on other embodiment (the 2) of this invention. It is a schematic diagram which shows the structure of the projector which concerns on one Embodiment provided with the light source device of embodiment of this invention.

  A light source device according to Embodiment 1 of the present invention includes a light source, and a phosphor wheel that transmits light from the light source and includes a first substrate and a second substrate in order from the light source side, The phosphor wheel has a first phosphor disposed between the first substrate and the second substrate, and a second phosphor, and the first phosphor and the first phosphor The two phosphors are arranged at different positions in the rotation direction of the phosphor wheel, the first phosphor is in contact with the first substrate and the second substrate, and the second phosphor is , In contact with the second substrate.

According to this embodiment, although the light incident side of the first phosphor is hot, the portion of the first phosphor that is hot contacts the first substrate, so that the first phosphor passes through the first substrate. Heat can be efficiently dissipated. Furthermore, since the first phosphor is also in contact with the second substrate, heat can be radiated more effectively using the two substrates. In addition, since the second phosphor is radiated through the second substrate, the first substrate can be preferentially used for radiating the first phosphor, and the first phosphor can be radiated. Is promoted. Even if the first phosphor is a phosphor that is easily affected by heat, the temperature rise can be prevented and the wavelength conversion efficiency can be prevented from lowering.
Therefore, it is possible to provide a light source device that is hardly affected by the heat generation of the phosphor and can suppress a decrease in light emission efficiency.

  In this embodiment, the substrate may have an optical film such as a filter on the surface in contact with the phosphor. The second phosphor may be disposed on the light source side or on the opposite side of the light source with respect to the second substrate.

  The light source device according to Embodiment 2 of the present invention transmits light in the wavelength range of light from the light source to the light source side of the first phosphor and the second phosphor in Embodiment 1 described above. And a filter that reflects light in the wavelength region of the light wavelength-converted by the first phosphor and the second phosphor.

  According to this embodiment, since the light source side of the phosphor has a filter that transmits light in the wavelength region of the light from the light source and reflects light in the wavelength region of the light wavelength-converted by the phosphor, Even when the light wavelength-converted by the phosphor returns to the light source side, it is reflected to the phosphor side by the filter on the light source side, so that the light is effectively used to increase the wavelength conversion efficiency of the phosphor. Can do.

  In the light source device according to Embodiment 3 of the present invention, the light source device according to Embodiment 1 or 2 has a wavelength region of light wavelength-converted by the first phosphor on the side opposite to the light source of the first phosphor. A wavelength of light that has a filter that transmits light and reflects light in a wavelength region of light from the light source, and is wavelength-converted by the second phosphor on the side opposite to the light source of the second phosphor A filter that transmits light in the region and reflects light in the wavelength region of the light from the light source.

  According to this embodiment, on the side opposite to the light source of the phosphor, there is a filter that transmits light in the wavelength region of the light wavelength-converted by the phosphor and reflects light in the wavelength region of the light from the light source. Therefore, only light in a desired wavelength region can be extracted and output, and thus a light source device with high performance can be realized.

  In the light source device according to Embodiment 4 of the present invention, in any one of Embodiments 1 to 3, the first phosphor is in direct contact with the surface of the first substrate opposite to the light source.

  According to this embodiment, the first phosphor is in direct contact with the surface opposite to the light source of the first substrate, and the region where the temperature is highest in the first phosphor on the light incident side is the first. 1 is in direct contact with the substrate. Therefore, the first phosphor can be efficiently cooled, and even if the first phosphor is a phosphor that is easily affected by heat, a decrease in wavelength conversion efficiency can be effectively prevented.

  In the light source device according to Embodiment 5 of the present invention, in any one of Embodiments 1 to 4, the first phosphor is in direct contact with the light source side surface of the second substrate.

  According to this embodiment, since the first phosphor is in direct contact with the light source side surface of the second substrate, the first phosphor can be efficiently cooled together with the first substrate. .

  In the light source device according to Embodiment 6 of the present invention, in any one of Embodiments 1 to 5, the thickness of the first phosphor is larger than the thickness of the second phosphor.

  According to this embodiment, since the thickness of the first phosphor is larger than the thickness of the second phosphor, the first phosphor reliably contacts the first substrate and the second substrate. Therefore, the first phosphor can be effectively cooled.

  The light source device according to Embodiment 7 of the present invention is the light source device according to any one of Embodiments 1 to 6, wherein the light source emits blue light.

  In the light source device according to Embodiment 8 of the present invention, in any one of Embodiments 1 to 7, the first phosphor is a phosphor that emits red light.

  A phosphor that emits red light has a wavelength conversion efficiency that decreases as the temperature rises and may be susceptible to heat. However, as described above, according to this embodiment, the phosphor does not increase in temperature. Thus, a decrease in wavelength conversion efficiency can be prevented.

  A projector according to a first embodiment of the present invention includes a light source device according to any one of the first to eighth embodiments, and light of a plurality of wavelength bands emitted from the light source device based on image data. Light modulation means for sequentially modulating the image to form an image, and projection means for enlarging and projecting the image.

According to this embodiment, it is possible to provide a projector with high performance by including the light source device that is not easily affected by the heat generated by the phosphor and that can suppress a decrease in luminous efficiency.
Next, a light source device according to an embodiment of the present invention and a projector according to an embodiment including the light source device will be described in detail with reference to the drawings.

(Description of Light Source Device According to One Embodiment of the Present Invention)
A light source device according to one embodiment of the present invention will be described. First, the outline of the structure of the light source device according to one embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic side view showing an outline of the light source device 2.
As shown in FIG. 1, the light source device 2 includes a light source 10, a condenser lens 20 into which light emitted from the light source 10 enters, a phosphor wheel 30 into which light emitted from the condenser lens 20 enters, and a phosphor wheel. And a light receiving lens 40 on which 30 outgoing lights are incident. The phosphor wheel 30 is a disk-like phosphor wheel that transmits light from a light source, and is rotated by a drive motor 50 via a drive shaft 52. In FIG. 1, the light source 10 includes the light source 10, the condensing lens 20, the phosphor wheel 30, and the light receiving lens 40. However, the light source device 2 does not include the light receiving lens 40. There may be an embodiment in which the light source device 2 is configured by the condenser lens 20 and the phosphor wheel 30.

  Next, the outline of the light source device 2 will be described along the flow of light emitted from the light source 10. In the present embodiment, a case where a semiconductor laser that emits blue light is used as the light source 10 will be described as an example. Blue light is emitted from the light source 10, and the emitted blue light enters the condenser lens 20, is collected by the condenser lens 20, and enters the phosphor wheel 30 that is rotated by the drive motor 50. The phosphor wheel 30 is made of a material that transmits light, and the phosphor is provided in at least a part of the region. As a phosphor, for example, a red phosphor emits red light when blue light is incident, and a green phosphor emits green light when blue light is incident, and a yellow phosphor emits blue light. Emits yellow light when incident. These phosphors only have to be light having a wavelength shorter than that of the color, and the light of the color is similarly emitted not only with blue light but also with ultraviolet light. Further, in a region where no phosphor is provided, the blue light from the light source is transmitted without being wavelength-converted. When ultraviolet light is used, a blue phosphor that emits blue light when ultraviolet light is incident can be used to emit blue light. Therefore, the phosphor wheel 30 is divided in the rotation direction into a region where the red phosphor is provided, a region where the green phosphor is provided, a region where the yellow phosphor is provided, and a region where the phosphor is not provided. If blue light enters the phosphor wheel 30 from the condenser lens 20, red light, green light, yellow light, and blue light are emitted from the phosphor wheel 30 in a time-sharing manner and enter the light receiving lens 40. . Then, the light is converted into parallel light by the light receiving lens 40 and emitted from the light source device 2. The light receiving lens 40 can emit light not only in the case of emitting parallel light, but also in the direction in which the light spreads, and can be condensed at a predetermined position.

(Description of phosphor wheel)
Next, the structure of the phosphor wheel 30 according to one embodiment of the present invention will be described with reference to FIGS. 1 and 2.
The phosphor wheel 30 is a transmissive phosphor wheel that transmits light from the light source 10, and includes a first substrate 32 and a second substrate 34 in order from the light source 10 side. The first substrate 32 and the second substrate 34 are fixed to the drive shaft 52 of the drive motor 50, and are rotated about the drive shaft 52 by the drive force of the drive motor 50. That is, the positions of the first substrate 32 and the second substrate 34 are fixed by the drive shaft 52. However, the method of fixing the relative positions of the first substrate 32 and the second substrate 34 is not limited to the case where the drive shaft 52 is used. For example, the first substrate 32 and the second substrate 34 are used. It can be fixed by any other means such as inserting a spacer between them.
The phosphor wheel 30 includes a first phosphor 36 </ b> R that is a red phosphor between the first substrate 32 and the second substrate 34, and the first phosphor 36 </ b> R is the first substrate 32. And in contact with the surface of the second substrate 34. The second phosphor 36G, which is a green phosphor, is disposed in contact with the light source side surface of the second substrate 34. As shown in FIG. 2B viewed from the arrow B in FIG. 1, the yellow phosphor is also disposed as the second phosphor 36Y in contact with the light source side surface of the second substrate 34. At this time, unlike the first phosphor 36 </ b> R, the second phosphors 36 </ b> G and 36 </ b> Y are not in contact with the first substrate 32. As the second fluorescent material, the green fluorescent material 36G and the yellow fluorescent material 36Y are described, but it is sufficient that at least one of them is indicated, in other words, either the green fluorescent material 36G or the yellow fluorescent material 36Y. It only has to point to one side. That is, it goes without saying that one phosphor may be used as the second phosphor.

  More specifically, as shown in FIG. 2B, on the light source side surface of the second substrate 34, there are a first phosphor 36R which is a red phosphor, a green phosphor and a yellow phosphor. The second phosphors 36 </ b> G and 36 </ b> Y are arranged at different positions in the rotation direction of the phosphor wheel 30. The “positions different in the rotation direction” include not only the case where they are arranged on the same axis with respect to the rotation axis of the phosphor wheel 30 but also the case where they are arranged off the same axis.

Light in the wavelength range of light from the light source 10 is transmitted to the light source side of the first phosphor 36R and the second phosphors 36G, 36Y, and is transmitted by the first phosphor 36R and the second phosphors 36G, 36Y. A filter 60 that reflects light in the wavelength region of the wavelength-converted light is provided. In the embodiment shown in FIG. 1, the filter 60 is provided on the light source side of the first substrate 32. Specifically, as the filter 60, a short-pass filter that transmits light in the blue wavelength range and reflects light in the green, yellow, and red wavelength ranges can be used.
In general, residual reflection of about 4% occurs at the interface between glass and air. For example, by forming a short-pass filter by depositing a dielectric multilayer film, the reflectance is reduced to 0. .5% or less. Furthermore, since the light returning to the light source 10 among the light converted in wavelength by the phosphors 36R, 36G, and 36Y can be reflected to the emission side, the light emission efficiency of the light source device 2 can be improved. Further, in order to improve luminance unevenness and chromaticity unevenness, particles such as scatterers such as SiO ₂ , TiO ₂ , and Ba ₂ SO ₄ can be applied.

  On the side opposite to the light source of the first phosphor 36R, a filter 62R that transmits light in the wavelength region of the light wavelength-converted by the first phosphor 36R and reflects light in the wavelength region of light from the light source 10 is provided. Have. In the embodiment shown in FIG. 1, the second substrate 34 has a filter 62R on the surface opposite to the light source at a position corresponding to the first phosphor 36R in the rotation direction. Specifically, a long-pass filter that transmits light in the wavelength range of red light and reflects blue light can be used as the filter 62R. It should be noted that light in the wavelength range between blue light and red light, for example, light in the wavelength range of yellow light and green light, can be transmitted or reflected, depending on the application. Thus, the optimum transmission wavelength range of the filter can be determined.

Similarly, light in the wavelength region of the light converted by the second phosphors 36G and 36Y is transmitted to the opposite side of the light source of the second phosphors 36G and 36Y, respectively, and the wavelength region of the light from the light source is transmitted. It has filters 62G and 62Y that reflect light. In the embodiment shown in FIG. 1, filters 62G and 62Y are provided on the surface opposite to the light source of the second substrate 34 at positions corresponding to the second phosphors 36G and 36Y in the rotation direction. Specifically, a band-pass filter that transmits light in the green wavelength region and reflects blue light can be used as the filter 62G. In addition, yellow light having a longer wavelength than green light and light in the wavelength range of red light can be transmitted or reflected, and the optimum transmission wavelength of the filter can be selected depending on the application. The area can be defined.
As the filter 62Y, a band-pass filter that transmits light in the wavelength region of yellow light and reflects blue light can be used. However, the filter 62Y is not particularly provided, and is white by mixing blue light and yellow light without providing the filter 62Y. May be emitted. Note that the light in the wavelength range of green light and the light in the wavelength range of red light can be transmitted or reflected, and the optimum transmission wavelength range of the filter according to the application. Can be determined.

Here, the arrangement of the first substrate 32 and the second substrate 34 on each surface will be described with reference to FIG. FIG. 2A is a view showing the light source side surface of the first substrate 32 as viewed from the arrow A in FIG. 1, and the first substrate 32 is in a region where the phosphor is provided on the back surface side. And a filter 60.
FIG. 2B is a view showing the light source side surface of the second substrate 34 as viewed from the arrow B in FIG. 1, and the red emission region SR, the green emission region SG, and the yellow color at different positions in the rotation direction. An emission area SY and a blue emission area SB are provided. On the surface of the first substrate 32 on the light source side, the red emission region SR has a first phosphor 36R that is a red phosphor, and the green emission region SG has a second phosphor that is a green phosphor. The yellow emission region SY has a second phosphor 36Y that is a yellow phosphor. Further, the blue emission region SB has no phosphor.
When the range of each area is represented by a fan-shaped central angle, the case of 120 degrees in the red emission area SR, 110 degrees in the green emission area SG, 70 degrees in the yellow emission area SY, and 60 degrees in the blue emission area SB is illustrated. This is possible, but is not limited to this.

FIG. 2C is a view showing a surface of the second substrate 34 opposite to the light source as viewed from the arrow C in FIG. 1, and the second substrate 34 shown in FIG. Corresponding to the surface, a red emission area SR, a green emission area SG, a yellow emission area SY, and a blue emission area SB are provided at different positions in the rotation direction.
As described above, the red emission region SR transmits the light in the wavelength region of the red light wavelength-converted by the first phosphor 36R and reflects the light in the wavelength region of the blue light from the light source 10. Have As described above, the green emission region SG includes a filter 62G that transmits the light in the wavelength region of the green light wavelength-converted by the second phosphor 36G and reflects the light in the wavelength region of the blue light from the light source. Have. In the yellow emission region SY, as described above, the filter 62Y that transmits the light in the wavelength region of the yellow light wavelength-converted by the second phosphor 36Y and reflects the light in the wavelength region of the blue light from the light source is provided. However, the filter 62Y may not be provided, and white may be emitted by mixing the blue light and the yellow light.
Further, the blue emission region SB has no filter. However, a scatterer, for example, SiO ₂ , TiO ₂ , Ba ₂ SO, or the like is used to form an antireflection film by depositing an electric multilayer on the blue emission region SB or to improve luminance unevenness and chromaticity unevenness. It is also possible to form a layer having particles such as ₄ .

  In FIG. 2, a phosphor wheel having four areas of a red emission area SR, a green emission area SG, a yellow emission area SY, and a blue emission area SB is shown. For example, the yellow emission area SY is excluded. A phosphor wheel having three regions of a red emission region SR, a green emission region SG, and a blue emission region SB can also be used.

As described above, in the phosphor wheel 30 shown in FIGS. 1 and 2, the first phosphor 36 </ b> R is in direct contact with the surface of the first substrate 32 opposite to the light source, and the second substrate 34. It is also in direct contact with the light source side surface. The second phosphors 36G and 36Y are in direct contact with the light source side surface of the second substrate 34, but are not in contact with the first substrate 32.
In addition, the thickness of the first phosphor in contact with both the first substrate 32 and the second substrate 34 is in contact with only the second substrate 34 (that is, a space is formed between the first substrate 32 and the first substrate 34). The thickness of the second phosphors 36G and 36Y.

According to the present embodiment, in the first phosphor 36R, the light incident side is at a high temperature, but the portion of the first phosphor 36R at a high temperature is in contact with the first substrate 32. Heat can be efficiently radiated through the substrate 32. In particular, as shown in FIG. 1, the first phosphor 36R is in direct contact with the surface of the first substrate 32 opposite to the light source, and is the highest temperature in the first phosphor 36R on the light incident side. This region is in direct contact with the first substrate 32. Therefore, the first phosphor 36R can be cooled more efficiently, and even if the first phosphor 36R is a phosphor that is easily affected by heat, it effectively prevents a decrease in wavelength conversion efficiency. Can do.
Furthermore, since the first phosphor 36R is also in contact with the second substrate 34, the two substrates 32 and 34 can be used to efficiently dissipate heat. In particular, as shown in FIG. 1, since the first phosphor 36R is in direct contact with the light source side surface of the second substrate 34, the first phosphor 36R is more effective together with the first substrate 32. Can be cooled.
In addition, since the second phosphors 36G and 36Y are radiated through the second substrate 34, the first substrate 32 can be preferentially used for radiating heat from the first phosphor 36R. The heat radiation of the first phosphor 36R is promoted.

Therefore, even if the first phosphor 36R is susceptible to heat due to a decrease in wavelength conversion efficiency when the temperature rises, as described above, the temperature increase is prevented and the wavelength conversion efficiency is reduced. Can be prevented. In addition, the second phosphors 36G and 36Y made of a green phosphor or a yellow phosphor that are not easily affected by heat compared to the red phosphor can have a sufficient wavelength even when cooled using only the second substrate 34. Conversion efficiency can be maintained.
Therefore, it is possible to provide the light source device 2 that is not easily affected by the heat generated by the phosphor and can suppress a decrease in light emission efficiency.

    According to the present embodiment, since the thickness of the first phosphor 36R is larger than the thickness of the second phosphors 36G and 36Y, the first phosphor 36R is the first substrate 32 and the second substrate 36R. Thus, the first phosphor 36R can be effectively cooled.

  According to the present embodiment, light in the wavelength range of the light from the light source 10 is transmitted to the light source side of the phosphors 36R, 36G, and 36Y, and the wavelength range of the light converted by the phosphors 36R, 36G, and 36Y Since the filter 60 that reflects light is provided, even if the light whose wavelength has been converted by the phosphors 36R, 36G, and 36Y returns to the light source side, it is reflected to the phosphor side by the filter 60 on the light source side. Therefore, the wavelength conversion efficiency of the phosphor can be increased by effectively utilizing light.

  According to the present embodiment, the wavelength of the light from the light source 10 is transmitted to the opposite side of the light sources of the phosphors 36R, 36G, and 36Y by transmitting the light in the wavelength region of the light converted by the phosphors 36R, 36G, and 36Y Since the filters 62R, 62G, and 62Y that reflect the light in the region are included, only the light in the desired wavelength region can be extracted and output, thereby realizing the light source device 2 with high light performance.

If the first phosphor has at least a material that is susceptible to heat due to a decrease in wavelength conversion efficiency when the temperature rises compared to the second phosphor, two or more different phosphors can be used. It may be laminated. For example, when a red phosphor is used as a material that is susceptible to heat, the first phosphor may have a laminated structure of a yellow phosphor and a red phosphor. In this case, the two phosphors are stacked so that the yellow phosphor contacts the first substrate 32 on the light source side, and the red phosphor contacts the second substrate 34 on the opposite side of the light source. Blue light is incident on the yellow phosphor, and blue light and yellow light converted by the yellow phosphor are incident on the red phosphor to emit red light. It is preferable because the heat generated in the red phosphor can be effectively dissipated to the second substrate 34 and the amount of heat generated from the red phosphor itself can be suppressed.

<Description of each member constituting light source device>
Below, further detailed description of each member which comprises the light source device 2 is given.
[Light source 10]
When a blue semiconductor laser is used as the light source 10, it is preferable to emit light in the wavelength region of 370 to 500 nm, and it is more preferable to emit light in the wavelength region of 420 to 500 nm. However, the present invention is not limited to the case where a blue semiconductor laser is used as the light source 10, and a semiconductor laser having any other wavelength region can be used, and other types of light sources such as LEDs can be used.

[Phosphor wheel substrate]
As the material of the transparent disc-shaped first substrate 32 and the second substrate 34 that transmit light, any material can be used as long as the material has high light transmittance. For example, glass, resin, Sapphire or the like can be used.

[Phosphor]
As described above, when blue light is incident from the light source as described above, a red phosphor 36R that outputs red light, a green phosphor 36G that outputs green light, and a yellow phosphor 36Y that outputs yellow light are used. It can be illustrated. Such a layer can be provided on the surface of the first substrate 32 or the second substrate 34 by coating or the like.
The red phosphor 36R that outputs red light preferably generates red fluorescence having a wavelength band of about 600 to 800 nm. Specific examples of the material include (Sr, Ca) AlSiN ₃ : Eu, CaAlSiN ₃ : Eu, SrAlSiN ₃ : Eu, and K ₂ SiF ₆ : Mn.
The phosphor 36G that outputs green light preferably generates green fluorescence having a wavelength band of about 500 to 560 nm. An example of a specific _{material, β-Si 6-Z Al} Z O Z N 8-Z: Eu, Lu 3 Al 5 O 12: Ce, Ca 8 MgSi 4 O 16 C l2: Eu, Ba 3 Si 6 O ₁₂ N ₂ : Eu, (Sr, Ba, Ca) Si ₂ O ₂ N ₂ : Eu, and the like can be given.
The phosphor 36Y that outputs yellow light preferably generates yellow to red fluorescence in a wavelength band of about 540 to 700 nm. Examples of the material include phosphors based on yttrium / aluminum oxide phosphors activated with cerium. More specifically, YAlO ₃ : Ce, Y ₃ Al ₅ O ₁₂ : Ce (YAG: Ce), Y ₄ Al ₂ O ₉ : Ce, and a mixture thereof are also included. The yttrium / aluminum oxide phosphor may contain at least one of Ba, Sr, Mg, Ca, and Zn. Moreover, by containing Si, the reaction of crystal growth can be suppressed and phosphor particles can be aligned.

[Drive motor]
The drive motor 50 is a brushless DC drive motor, and is arranged so that the drive shaft 52 and the optical axis of the condenser lens 20 are parallel to each other. Further, the surface of the phosphor wheel 30 is fixed so as to be perpendicular to the drive shaft 52. The rotation speed of the drive motor 50 is a rotation speed based on the frame rate of the moving image to be reproduced (the number of frames per second. The unit is [fps]). For example, when a moving image of 60 [fps] can be reproduced, the rotational speed of the drive motor 50 (that is, the phosphor wheel 30) is preferably set to an integral multiple of 60 revolutions per second.

(Description of phosphor wheel according to other embodiment of the present invention)
Next, a phosphor wheel according to another embodiment of the present invention will be described with reference to FIGS.
<Description of Embodiment shown in FIG. 3>
First, a phosphor wheel (No. 1) according to another embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic side view showing an outline of a phosphor wheel 30 according to another embodiment. The embodiment shown in FIG. 3 differs from the embodiment shown in FIG. 1 in the following points.
In the embodiment shown in FIG. 1, the filter 60 is provided on the light source side surface of the first substrate 32, whereas in the embodiment shown in FIG. In the embodiment shown in FIG. 1, the filters 62R, 62G and 62Y are provided on the surface opposite to the light source of the second substrate 34, whereas in the embodiment shown in FIG. The difference is that the second substrate 34 is provided on the light source side surface. Accordingly, the antireflection film 64 is provided on the light source side surface of the first substrate 32 and the surface of the second substrate 34 opposite to the light source.

The antireflection film 64 is made of a dielectric multilayer film, and the reflectance can be suppressed to 0.5% or less by the antireflection film 64 provided on the light source side surface of the first substrate 32. Similarly, light can be efficiently emitted from the phosphor wheel 30 by the antireflection film 64 provided on the surface of the second substrate 34 opposite to the light source.
The light on the side opposite to the light source of the first substrate 32 transmits light in the wavelength region of the light from the light source 10 and is wavelength-converted by the first phosphor 36R and the second phosphors 36G and 36Y. Is provided with a filter 60 that reflects light in the wavelength region. Further, light in the wavelength range of the light converted by the first phosphor 36R, the second phosphor 36G, and 36Y is transmitted to the surface on the light source side of the second substrate 34, and the light from the light source is transmitted. Filters 62R, 62G, and 62Y that reflect light in the wavelength band are provided.

  The heat generated in the first phosphor 36R is dissipated by the first substrate 32 having the filter 60 and the second substrate 34 having the filter 62R, and the heat generated in the second phosphors 36G and 36Y is filtered. Heat is radiated by the second substrate 34 having 62G and 62Y. At this time, the filters 60, 62R, 62G, and 62Y are all very thin and have a very low thermal resistance. Therefore, in the case of the embodiment shown in FIG. 3, as in the embodiment shown in FIGS. The first phosphor 36R is in contact with the first substrate 32 and the second substrate 34, and the second phosphors 36G and 36Y are in contact with the second substrate 34, but are in contact with the first substrate 32. It can be said that it is not in a state.

  Therefore, although the light incident side of the first phosphor 36R has a high temperature, the high temperature portion of the first phosphor 36R is in contact with the first substrate 32, so that the efficiency is increased through the first substrate 32. Heat dissipation. Furthermore, since the first phosphor 36R is also in contact with the second substrate 34, heat can be radiated more effectively by using the two substrates 32 and 34. In addition, since the second phosphors 36G and 36Y are radiated through the second substrate 34, the first substrate 32 can be preferentially used for radiating heat from the first phosphor 36R. The heat radiation of the first phosphor 36R is promoted. Even if the first phosphor 36R is a phosphor that is easily affected by heat, the temperature rise can be prevented and the wavelength conversion efficiency can be prevented from decreasing.

<Description of Embodiments Shown in FIGS. 4 and 5>
Next, a phosphor wheel (No. 2) according to another embodiment of the present invention will be described with reference to FIGS. FIG. 4A is a schematic side view showing an outline of the phosphor wheel 30 according to another embodiment, and FIG. 4B shows an embodiment in which a third substrate 35 is further provided. It is a typical side view. FIG. 5A is a diagram showing a light source side surface of the first substrate 32 as viewed from the arrow D in FIG. 4A, and FIG. 5B is an arrow E in FIG. FIG. 5C is a view showing a surface on the light source side of the second substrate 34 viewed from the side, and FIG. 5C is a surface on the opposite side of the light source of the second substrate 34 viewed from the arrow F in FIG. FIG. The embodiment shown in FIGS. 4 and 5 differs from the embodiment shown in FIGS. 1 and 2 in the following points.
In the embodiment shown in FIGS. 1 and 2, the second phosphors 36G and 36Y are provided on the light source side surface of the second substrate 34, whereas in the embodiment shown in FIGS. The second phosphors 36G and 36Y are different in that they are provided on the surface of the second substrate 34 opposite to the light source. Accordingly, in the embodiment shown in FIG. 4A, the filters 62G and 62Y are stacked on the second phosphors 36G and 36Y, and in the embodiment shown in FIG. 4B, the filter 62R. , 62G, 62Y, a third substrate 35 is provided.

More specifically, as shown in FIGS. 4A and 4B, the phosphor wheel 30 includes a first phosphor 36 </ b> R between the first substrate 32 and the second substrate 34. The first phosphor 36R is disposed in contact with the surfaces of the first substrate 32 and the second substrate 34. Further, the second phosphors 36G and 36Y are disposed in contact with the surface of the second substrate 34 opposite to the light source.
The first substrate 32 transmits the light in the wavelength region of the light from the light source 10 to the surface on the light source side, and the wavelength of the light subjected to wavelength conversion by the first phosphor 36R and the second phosphors 36G and 36Y. It has a filter 60 that reflects the light in the region.

In the embodiment shown in FIG. 4A, the second substrate 34 is wavelength-converted by the first phosphor 36R on the surface opposite to the light source at the position corresponding to the first phosphor 36R in the rotation direction. The filter 62 </ b> R transmits the light in the wavelength region of the emitted light and reflects the light in the wavelength region of the light from the light source 10.
On the other hand, the second phosphors 36G and 36Y transmit light in the wavelength region of the light converted by the second phosphors 36G and 36Y onto the second phosphors 36G and 36Y, respectively. Filters 62G and 62Y that reflect the light in the wavelength range of the light from are stacked.

Next, the arrangement on each surface of the first substrate 32 and the second substrate 34 corresponding to FIG. 4A will be described with reference to FIG. As shown in FIG. 5A, the first substrate 32 has a filter 60 in a region on the light source side where a phosphor is provided on the back side.
As shown in FIG. 5B, the light emitting side surface of the second substrate 34 is positioned at different positions in the rotation direction, and the red emission region SR is respectively formed on the surface of the second substrate 34 on the light source side. The green emission area SG, the yellow emission area SY, and the blue emission area SB are provided, but only the red emission area SR is provided with the first phosphor 36R that is a red phosphor.
As shown in FIG. 5C, on the surface of the second substrate 34 opposite to the light source, the red emission region is located on the surface opposite to the second substrate at different positions in the rotation direction. SR, green emission area SG, yellow emission area SY, and blue emission area SB are provided. The red emission region SR has a filter 62R that transmits light in the wavelength region of red light that has been wavelength-converted by the first phosphor 36R and reflects light in the wavelength region of blue light from the light source. Is provided.

In the green emission region SG, the second phosphor 36G and the light in the wavelength region of the green light wavelength-converted by the second phosphor 36G are transmitted therethrough, and the light in the wavelength region of blue light from the light source is transmitted. Is provided. In the yellow emission region SG, the second phosphor 36Y and the light in the wavelength region of green light wavelength-converted by the second phosphor 36Y are transmitted therethrough, and the light in the wavelength region of blue light from the light source is transmitted. Has a filter 62Y.
Further, although the blue emission region SB does not have a filter, an antireflection film or a scattering layer can be formed.

However, when it is difficult to stack the filters 62G and 62Y as optical films on the second phosphors 36G and 36Y, as shown in FIG. Three substrates 35 can also be used. By providing filters 60R, 62G, and 62Y on the third substrate 35 and disposing them on the opposite side of the light source with respect to the first phosphor 36R and the second phosphors 36G and 36Y, the same function is obtained. be able to. Although the position with respect to the 1st board | substrate 32 and the 2nd board | substrate 34 is being fixed by the drive shaft 52, the 3rd board | substrate 35 can also be fixed by inserting a spacer.
Note that the filter 60R can be provided not on the third substrate 35 but on the surface opposite to the light source of the second substrate 34, as in the embodiment of FIG. 4A.

Also in the case of the embodiment shown in FIGS. 4 and 5, the first phosphor 36R is in contact with the first substrate 32 and the second substrate 34, as in the embodiment shown in FIGS. The second phosphors 36G and 36Y are in contact with the second substrate 34, but are not in contact with the first substrate 32.
Therefore, although the light incident side of the first phosphor 36R has a high temperature, the high temperature portion of the first phosphor 36R is in contact with the first substrate 32, so that the efficiency is increased through the first substrate 32. Heat dissipation. Furthermore, since the first phosphor 36R is also in contact with the second substrate 34, heat can be radiated more effectively by using the two substrates 32 and 34. In addition, since the second phosphors 36G and 36Y are radiated through the second substrate 34, the first substrate 32 can be preferentially used for radiating heat from the first phosphor 36R. The heat radiation of the first phosphor 36R is promoted. Even if the first phosphor 36R is a phosphor that is easily affected by heat, the temperature rise can be prevented and the wavelength conversion efficiency can be prevented from decreasing.

(Description of the projector of the present invention)
Next, the case where the light source device 2 shown in the above-described embodiment is used as a light source device in a so-called one-chip type DLP projector will be described with reference to FIG. FIG. 6 is a schematic diagram for illustrating the configuration of the projector 4 according to one embodiment provided with the light source device 2 shown in the above-described embodiment, and the light source device 2 and the projector 4 are viewed from above. It is a typical top view.
In FIG. 6, light emitted from the light source device 2 enters a DMD (Digital Micromirror Device) element (light modulation means) 70 that is a spatial light modulator via an optical system. Then, it is reflected by the DMD element 70, condensed by the projection lens 80 that is a projection means, and projected onto the screen 90. The DMD element 70 is an array of fine mirrors corresponding to each pixel of the image projected on the screen, and turns on the light emitted to the screen by changing the angle of each mirror in units of microseconds. Can be turned off.
In addition, by changing the gradation of light incident on the projection lens according to the ratio of the time when each mirror is turned on and the time when it is turned off, gradation display based on the image data of the image to be projected becomes possible. Become.

In the present embodiment, the DMD element is used as the light modulation means. However, the present invention is not limited to this, and any other light modulation element can be used depending on the application. Further, the light source device 2 and the projector 4 using the light source device 2 according to the present invention are not limited to the above-described embodiments, and other various embodiments are included in the present invention.
In the present embodiment, the light receiving lens 40 is included in the light source device 2, but is not limited thereto. For example, the light receiving lens 40 may not be included in the light source device 2 but may be included in a part of the optical system.

As described above, the projector 4 according to the present embodiment sequentially modulates light of a plurality of wavelength bands emitted from the light source device 2 based on the light source device 2 shown in the above-described embodiment and the image data. A DMD element (light modulation means) 70 to be formed and a projection lens (projection means) 80 for enlarging and projecting an image are provided.
According to the present embodiment, it is possible to provide the projector 4 with high performance by including the light source device 2 that is not easily affected by the heat generation of the phosphor and that can suppress the decrease in the light emission efficiency.

  Although the embodiments and embodiments of the present invention have been described, the disclosed contents may vary in the details of the configuration, and combinations of elements and changes in the order of the embodiments, embodiments, etc. are claimed in the present invention. It can be realized without departing from the scope and spirit of the present invention.

2 Light source device 4 Projector 10 Light source 20 Condensing lens 30 Phosphor wheel 32 First substrate 34 Second substrate 35 Third substrate 36 Phosphor 36R Red phosphor (first phosphor)
36G green phosphor (second phosphor)
36Y yellow phosphor (second phosphor)
40 Light-receiving lens 50 Drive motor 52 Drive shaft 60 Filter 62 Filter 62R Filter 62G corresponding to red phosphor 62G Filter corresponding to green phosphor 62Y Filter 64 corresponding to yellow phosphor Antireflection film
70 DMD element 80 Projection lens 90 Screen SR Red emission area SG Green emission area SB Blue emission area

Claims (9)

A light source;
A phosphor wheel that transmits light from the light source and has a first substrate and a second substrate in order from the light source side;
With
The phosphor wheel is
A first phosphor disposed between the first substrate and the second substrate;
A second phosphor;
Have
The first phosphor and the second phosphor are arranged at different positions in the rotation direction of the phosphor wheel,
The first phosphor is in contact with the first substrate and the second substrate;
The light source device , wherein the second phosphor is not in contact with the first substrate and is in contact with only the second substrate.   Light in the wavelength range of the light from the light source is transmitted to the light source side of the first phosphor and the second phosphor, and wavelength conversion is performed by the first phosphor and the second phosphor. The light source device according to claim 1, further comprising a filter that reflects light in a wavelength region of light.   On the opposite side of the light source of the first phosphor, there is a filter that transmits light in the wavelength region of the light wavelength-converted by the first phosphor and reflects light in the wavelength region of light from the light source. A filter that transmits light in a wavelength region of light converted by the second phosphor to a side opposite to the light source of the second phosphor and reflects light in the wavelength region of light from the light source The light source device according to claim 1, wherein:   4. The light source device according to claim 1, wherein the first phosphor is in direct contact with a surface opposite to the light source of the first substrate. 5.   5. The light source device according to claim 1, wherein the first phosphor is in direct contact with a light source side surface of the second substrate.   6. The light source device according to claim 1, wherein a thickness of the first phosphor is larger than a thickness of the second phosphor.   The light source device according to claim 1, wherein the light source is a light source that emits blue light.   The light source device according to claim 1, wherein the first phosphor is a phosphor that emits red light. The light source device according to any one of claims 1 to 8,
A light modulation unit that sequentially modulates light of a plurality of wavelength bands emitted from the light source device to form an image based on image data;
Projection means for enlarging and projecting the image;
A projector comprising:

Images