Optical element unit, light source device, and projector

Abstract

To provide an optical element unit with improved cooling efficiency, a light source device, and a projector.SOLUTION: The optical element unit comprises: an optical element wheel including a heat radiation member provided on one surface of a wheel substrate and radially outwards flowing air flow by rotating the wheel substrate; a storage part including an outer peripheral wall covering the circumference of the optical element wheel and an opening partially opening the outer peripheral wall, capable of storing the optical element wheel; a first duct provided in the opening of the storage part for exhausting air flow generated by the optical element wheel from the storage part; a heat exchanger arranged in an exhaust port of the first duct, through which the air flow exhausted from the exhaust port flows; and a second duct guiding the air flow flowing through the heat exchanger to the heat radiation member of the optical element wheel.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an optical element unit, a light source device, and a projector.

Background Art

[0002] As a light source device for a projector, there is a technique of using fluorescence generated by a phosphor wheel (optical element wheel) as illumination light. For example, Patent Document 1 below discloses a technique of cooling by blowing an air current onto a heat dissipation member provided on a phosphor wheel in a sealed light source unit, and circulating the cooled air current through a heat exchanger to the optical element wheel.

[0003] In this light source unit, there is a risk that the heated air scattered in the unit by cooling the wheel may cause heat damage or deformation to other optical components such as lenses and mirrors arranged in the unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, in the technique disclosed in Patent Document 2 above, by housing the phosphor wheel and the heat exchanger in a storage container, the influence on other optical components due to the waste heat from the phosphor wheel is suppressed to a small level.

[0006] On the other hand, in recent years, there has been a demand for further increasing the luminance of illumination light in a light source unit used in a projector, and it is necessary to further improve the cooling efficiency of the phosphor wheel. However, the technology disclosed in Patent Document 2 mentioned above did not provide sufficient cooling efficiency for the phosphor wheel, leaving room for further improvement. Therefore, there was a need for a new technology that could cool the optical element wheel more efficiently. I was afraid. [Means for solving the problem]

[0007] To solve the above problems, according to one aspect of the present invention, an optical element unit is provided comprising: an optical element wheel having a heat dissipation member provided on one side of a wheel substrate, which causes airflow to flow radially outward as the wheel substrate rotates; a housing portion having an outer peripheral wall covering the outer circumference of the optical element wheel and an opening that opens a part of the outer peripheral wall, and capable of housing the optical element wheel; a first duct provided in the opening of the housing portion for discharging the airflow generated by the optical element wheel from the housing portion; a heat exchanger arranged at the outlet of the first duct for the airflow discharged from the outlet to flow through; and a second duct for guiding the airflow that has flowed through the heat exchanger to the heat dissipation member of the optical element wheel.

[0008] According to a second aspect of the present invention, a light source device is provided comprising an optical element unit according to the first aspect of the present invention and a light source for irradiating the optical element unit with light.

[0009] A third aspect of the present invention provides a projector comprising: an optical device according to the second aspect of the present invention; an optical modulator for modulating light from the light source device according to image information; and a projection optical device for projecting the light modulated by the optical modulator. According to one aspect of the present invention, Wheel substrate The device comprises: an optical element provided on the wheel substrate; an optical element wheel having at least one heat dissipation fin provided on one side of the wheel substrate, which causes airflow radially outward as the wheel substrate rotates; an outer peripheral wall covering the outer circumference of the optical element wheel; an opening that opens a part of the outer peripheral wall; a light-transmitting portion that transmits light from the optical element; a housing capable of housing the optical element wheel; and a radiator through which the airflow discharged from the opening flows in a first direction, through which the airflow flows in from the first direction, and through which the airflow can pass along the first direction. The airflow that flows out of the radiator in the first direction has its direction changed to a second direction intersecting the first direction, the airflow that has been changed to the second direction has its direction changed to a third direction which is opposite to the first direction, the airflow that has been changed to the third direction flows into the radiator from the third direction, flows out of the radiator in the third direction, and as the wheel substrate rotates, the airflow that has been changed to the third direction is taken into the at least one heat dissipation fin. [Brief explanation of the drawing]

[0010] [Figure 1] This figure shows a schematic configuration of the projector according to the first embodiment. [Figure 2] This is a diagram illustrating the schematic configuration of the light source device. [Figure 3]It is a perspective view showing a schematic configuration of a wavelength conversion unit. [Figure 4] It is a cross-sectional view showing a schematic configuration of a wavelength conversion unit. [Figure 5] It is a perspective view showing a main part configuration of a wavelength conversion wheel. [Figure 6] It is a cross-sectional view of the wavelength conversion wheel taken along the arrow VI-VI in FIG. 5. [Figure 7] It is a perspective view showing a schematic configuration of a wavelength conversion unit of the second embodiment. [Figure 8] It is a perspective view showing a schematic configuration of a wavelength conversion unit of the third embodiment. [Figure 9A] It is a plan view showing a schematic configuration of a wavelength conversion unit of the fourth embodiment. [Figure 9B] It is a side view showing a schematic configuration of a wavelength conversion unit of the fourth embodiment. [Figure 10] It is a cross-sectional view showing a main part configuration of a wavelength conversion unit of the first modification. [Figure 11] It is a cross-sectional view showing a main part configuration of a diffusion reflection unit of the first modification.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, for the sake of easy understanding of the features, there are cases where the characteristic parts are enlarged for convenience, and the dimensional ratios of each component are not necessarily the same as the actual ones.

[0012] (First Embodiment) As a first embodiment of the present invention, an example of a projector will be described. FIG. 1 is a diagram showing a schematic configuration of a projector according to this embodiment. As shown in FIG. 1, the projector 1 of the present embodiment is a projection type image display device that displays a color image on the screen SCR. The projector 1 includes a light source device 2, a color separation optical system 3, light modulation devices 4R, 4G, and 4B, a combining optical system 5, and a projection optical device 6.

[0013] The color separation optical system 3 separates the white illumination light WL from the light source device 2 into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a and a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b, and a third total reflection mirror 8c, and a first relay lens 9a and a second relay lens 9b.

[0014] The first dichroic mirror 7a separates the illumination light WL from the light source device 2 into red light LR and other light (green light LG and blue light LB). The first dichroic mirror 7a transmits the separated red light LR and reflects the other light. The second dichroic mirror 7b reflects the green light LG and transmits the blue light LB.

[0015] The first total reflection mirror 8a reflects the red light LR toward the light modulation device 4R. The second total reflection mirror 8b and the third total reflection mirror 8c guide the blue light LB to the light modulation device 4B. The green light LG is reflected from the second dichroic mirror 7b toward the light modulation device 4G.

[0016] The first relay lens 9a is disposed between the second dichroic mirror 7b and the second total reflection mirror 8b in the optical path of the blue light LB. The second relay lens 9b is disposed between the second total reflection mirror 8b and the third total reflection mirror 8c in the optical path of the blue light LB.

[0017] Optical modulator 4R modulates red light LR according to image information to form red image light. Optical modulator 4G modulates green light LG according to image information to form green image light. Optical modulator 4B modulates blue light LB according to image information to form blue image light.

[0018] Optical modulators 4R, 4G, and 4B utilize, for example, transmissive liquid crystal panels. Polarizing plates (not shown) are also placed on the incident and exit sides of the liquid crystal panel.

[0019] Furthermore, field lenses 14R, 14G, and 14B are positioned on the incident side of optical modulators 4R, 4G, and 4B, respectively.

[0020] Image light from optical modulators 4R, 4G, and 4B is incident on the combining optical system 5. The combining optical system 5 combines the image light from each device and emits this combined image light toward the projection optical system 6. A cross dichroic prism, for example, is used in the combining optical system 5.

[0021] The projection optical device 6 consists of a group of projection lenses and projects the image light synthesized by the composite optical system 5 toward the screen SCR, thereby displaying an enlarged color image on the screen SCR.

[0022] (Light source device) The configuration of the light source device 2 described above will be explained below. Figure 2 shows a schematic configuration of the light source device 2. Here, a light source device using a reflective fluorescent wheel that receives excitation light and emits light converted to fluorescence by a wavelength conversion element via a reflective member is shown as an example. As shown in Figure 2, the light source device 2 comprises a light source 21, a collimator optical system 22, a first phase difference plate 23, a homogenizer optical system 24, a polarization separation element 25, a first focusing optical system 26, a wavelength conversion unit (optical element unit) 40, a second phase difference plate 28, a second focusing optical system 29, a diffuse reflection section 30, and a uniform illumination optical system 80.

[0023] Of these components, the light source 21, the collimator optical system 22, the first phase difference plate 23, the homogenizer optical system 24, the polarization separation element 25, the second phase difference plate 28, the second focusing optical system 29, and the diffuse reflection section 30 are arranged sequentially on the optical axis ax1.

[0024] Meanwhile, the wavelength conversion unit 40, the first focusing optical system 26, and the polarization separation element 25 are arranged sequentially on the illumination optical axis ax2 of the light source device 2. The optical axis ax1 and the illumination optical axis ax2 are in the same plane and are in a positional relationship that is orthogonal to each other.

[0025] The light source 21 is composed of multiple semiconductor lasers 21a that emit blue light B, which is composed of laser light. The peak emission intensity of the blue light B is, for example, 445 nm. Note that semiconductor lasers 21a that emit blue light at wavelengths other than 445 nm, such as 455 nm or 460 nm, can also be used. The optical axis ax1 of the light source 21 is perpendicular to the illumination optical axis ax2 of the light source device 2. The light source 21 is constructed by arranging multiple semiconductor lasers 21a in an array within a single plane perpendicular to the optical axis ax1. Based on this configuration, the light source 21 emits a beam BL containing multiple blue light B rays.

[0026] The light beam BL emitted from the light source 21 enters the collimator optical system 22. The collimator optical system 22 converts the light beam BL emitted from the light source 21 into a parallel light beam. The collimator optical system 22 is composed of, for example, a plurality of collimator lenses 22a arranged in an array. Each of the plurality of collimator lenses 22a is positioned to correspond to one of the plurality of semiconductor lasers 21a.

[0027] The light beam BL that has passed through the collimator optical system 22 is incident on the first phase difference plate 23. The first phase difference plate 23 is, for example, a rotatable half-wave plate. The blue light B emitted from the semiconductor laser 21a is linearly polarized. By appropriately setting the rotation angle of the first phase difference plate 23, which is made of a half-wave plate, the light beam BL that has passed through the first phase difference plate 23 can be converted into light containing S-polarized light rays BLs and P-polarized light rays BLp in a predetermined ratio for the polarization separation element 25.

[0028] Light containing the above-mentioned light rays BLs and BLp is incident on the homogenizer optical system 24. The homogenizer optical system 24 works in cooperation with the first focusing optical system 26 to homogenize the illuminance distribution due to the light rays BLs on the wavelength conversion unit 40. The homogenizer optical system 24 also works in cooperation with the second focusing optical system 29 to homogenize the illuminance distribution due to the light ray BLc1, described later, on the diffuse reflection section 30.

[0029] The homogenizer optical system 24 is composed of, for example, a first multi-lens array 24a and a second multi-lens array 24b. The first multi-lens array 24a includes multiple first lenses 24am, and the second multi-lens array 24b includes multiple second lenses 24bm. Each of the multiple second lenses 24bm corresponds to one of the multiple first lenses 24am.

[0030] The wavelength conversion unit 40 and the diffuse reflection section 30 are each positioned to be optically conjugate with the first multi-lens array 24a (first lens 24am). In addition, the light emission region of the semiconductor laser 21a is positioned to be optically conjugate with the second multi-lens array 24b.

[0031] The polarization separation element 25 is positioned at the intersection of the mutually orthogonal optical axis ax1 and illumination optical axis ax2. The polarization separation element 25 has a polarization separation function that separates the light that has passed through the first phase difference plate 23 into an S-polarized component and a P-polarized component with respect to the polarization separation element 25. Specifically, the polarization separation element 25 reflects the S-polarized component rays BLs of the incident light and transmits the P-polarized component rays BLp of the incident light.

[0032] The S-polarized component, light ray BLs, is reflected by the polarization separation element 25 and heads towards the wavelength conversion unit 40. The P-polarized component, light ray BLp, passes through the polarization separation element 25 and heads towards the diffuse reflection section 30.

[0033] Furthermore, the polarization separation element 25 has a color separation function that transmits fluorescent YL, which will be described later, regardless of its polarization state, as it has a different wavelength band than the light beam BL from the light source 21.

[0034] The S-polarized light rays BLs emitted from the polarization separation element 25 are incident on the first focusing optical system 26. The first focusing optical system 26 focuses the light rays BLs toward the wavelength conversion element of the wavelength conversion unit 40. The first focusing optical system 26 is composed of, for example, pickup lenses 26a and 26b.

[0035] The light rays BLs emitted from the first focusing optical system 26 are incident on the wavelength conversion unit 40. The configuration of the wavelength conversion unit 40 will be described later. The fluorescent YL emitted from the wavelength conversion unit 40 is parallelized in the first focusing optical system 26 and passes through the polarization separation element 25.

[0036] Meanwhile, the P-polarized ray BLp emitted from the polarization separation element 25 is incident on the second phase difference plate 28. The second phase difference plate 28 is composed of a quarter-wave plate (λ / 4 plate) placed in the optical path between the polarization separation element 25 and the diffuse reflector 30. The ray BLp is converted into a circularly polarized ray BLc1 by passing through the second phase difference plate 28. The ray BLc1 that has passed through the second phase difference plate 28 is incident on the second focusing optical system 29.

[0037] The second focusing optical system 29 focuses the light ray BLc1 toward the diffuse reflector 30. The second focusing optical system 29 is composed of, for example, a pickup lens 29a and a pickup lens 29b.

[0038] The diffuse reflecting section 30 diffusely reflects the light ray BLc1 emitted from the second focusing optical system 29 toward the polarization separation element 25. Preferably, the diffuse reflecting section 30 is one that performs Lambertian reflection on the light ray BLc1 incident on the diffuse reflecting section 30.

[0039] The diffuse reflective section 30 comprises a diffuse reflective substrate 30A and a drive source 30M, such as a motor, for rotating the diffuse reflective substrate 30A. The rotation axis of the drive source 30M is arranged substantially parallel to the optical axis ax1. As a result, the diffuse reflective substrate 30A is configured to rotate within a plane that intersects with the principal ray of the light ray BLc1 incident on the diffuse element of the diffuse reflective substrate 30A. The diffuse reflective substrate 30A is formed, for example, in a circular shape when viewed from the direction of the rotation axis.

[0040] The circularly polarized light ray BLc2, reflected by the diffuse reflective substrate 30A and transmitted again through the second focusing optical system 29, then transmits again through the second phase difference plate 28 to become the S-polarized light ray BLs1.

[0041] The light ray BLs1 is combined with the fluorescent YL by the polarization separation element 25 to produce white illumination light WL. The illumination light WL is incident on the uniform illumination optical system 80.

[0042] The uniform illumination optical system 80 comprises an integrator optical system 81, a polarization conversion element 82, and a superimposed lens 83. The uniform illumination optical system 80 homogenizes the intensity distribution of the illumination light WL in the illuminated area. The illumination light WL emitted from the uniform illumination optical system 80 is incident on the color separation optical system 3.

[0043] Specifically, the integrator optical system 81 is composed of, for example, lens arrays 81a and 81b. Lens arrays 81a and 81b consist of multiple lenses arranged in an array.

[0044] The lens array 81b, together with the superimposed lens 83, images the images from each lens of the lens array 81a near the image forming areas of the optical modulator 4R, optical modulator 4G, and optical modulator 4B, respectively.

[0045] The illumination light WL that has passed through the integrator optical system 81 is incident on the polarization conversion element 82. The polarization conversion element 82 is composed of, for example, a polarization separation film and a phase difference plate, and converts the illumination light WL into linearly polarized light. Note that the polarization conversion element 82 may be omitted if necessary.

[0046] The illumination light WL that has passed through the polarization conversion element 82 is incident on the superposition lens 83. The superposition lens 83 focuses each partial light beam emitted from the polarization conversion element 82 and superimposes it near the image forming areas of the optical modulator 4R, optical modulator 4G, and optical modulator 4B, respectively. In this embodiment, the integrator optical system 81 and the superposition lens 83 make the illuminance distribution in the illuminated area uniform.

[0047] Next, the configuration of the wavelength conversion unit 40 will be described. Figure 3 is a perspective view showing the schematic configuration of the wavelength conversion unit 40. Figure 4 is a cross-sectional view showing the schematic configuration of the wavelength conversion unit 40. Figure 5 is a perspective view showing the main components of the wavelength conversion wheel 41. Figure 6 is a cross-sectional view of the wavelength conversion wheel 41 taken along the line VI-VI in Figure 5.

[0048] As shown in Figures 3 and 4, the wavelength conversion unit 40 of this embodiment includes a wavelength conversion wheel (optical element wheel) 41, a shroud (housing section) 42, a first duct 43, a heat exchanger 44, a second duct 45, and a fan 46.

[0049] As shown in Figure 4, the wavelength conversion wheel 41 comprises a wheel substrate 411, a wavelength conversion element (optical element) 412, a heat dissipation member 413, and a rotation drive unit 419. The rotation drive unit 419 is composed of, for example, a motor. The rotation drive unit 419 has a rotation support unit 419a that is rotatable about a central axis O. The rotation support unit 419a rotatably supports the wheel substrate 411 about the central axis O.

[0050] The following explanation will use the XYZ Cartesian coordinate system as needed. In each drawing, the X-axis is the axis along the optical axis (illumination optical axis ax2) of the fluorescent YL emitted from the wavelength conversion unit 40. The Y-axis is perpendicular to the X-axis and is the axis along the rotation axis O1 of the fan 46. The Z-axis is perpendicular to both the X-axis and the Y-axis.

[0051] Furthermore, the radial direction with respect to the central axis O is simply called the "radial direction." The direction away from the central axis O in the radial direction is called the "radial outward direction," and the direction approaching the central axis O in the radial direction is called the "radial inward direction." The circumferential direction with respect to the central axis O is simply called the "circumferential direction." The direction along the central axis O is called the "axial direction," with one side of the axial direction being called the "axial one side," and the other side being called the "axial other side."

[0052] The wheel substrate 411 is made of an annular metal plate with excellent heat dissipation properties, such as aluminum or copper. In other words, in this embodiment, the wheel substrate 411 has thermal conductivity.

[0053] The wavelength conversion element 412 is provided on the opposite surface (other surface) 411b of the wheel substrate 411 from the back surface 411a. The wavelength conversion element 412 is formed in an annular shape around the central axis O on the surface 411b of the wheel substrate 411. In other words, the wavelength conversion element 412 is provided in a ring shape around the central axis O.

[0054] The wavelength conversion element 412 is excited by the light ray BLs incident on the surface 412a as excitation light, and emits yellow fluorescence YL, which includes red and green light, from the surface 412a. The wavelength conversion element 412 is made of, for example, Y3Al5O 12 Garnet crystals (YAG) contain cerium ions (e.g., Ce 3+ A YAG:Ce atom with added ) is used. The wavelength conversion element 412 may also include a suitable scattering element (not shown).

[0055] In this embodiment, a reflective member 414 is provided between the back surface 412b of the wavelength conversion element 412 and the front surface 411b of the wheel substrate 411. The reflective member 414 reflects the light emitted from the back surface 412b of the wavelength conversion element 412 toward the front surface 412a of the wavelength conversion element 412.

[0056] As shown in Figures 4 and 5, the heat dissipation member 413 is provided on the back surface (one side) 411a of the wheel substrate 411. The heat dissipation member 413 has a base portion 413a and a plurality of heat dissipation fins 413b. The base portion 413a is joined to the back surface 411a of the wheel substrate 411. The base portion 413a is made of a metal disc with excellent heat dissipation properties, such as aluminum or copper. The base portion 413a has the same outer shape as the wheel substrate 411.

[0057] As shown in Figures 5 and 6, the multiple heat dissipation fins 413b are provided on the side of the base portion 413a opposite to the wheel substrate 411. In this embodiment, the multiple heat dissipation fins 413b are integrally formed with the base portion 413a. The multiple heat dissipation fins 413b are located radially outward from the rotation drive unit 419 and extend radially toward the outer edge of the base portion 413a. Each heat dissipation fin 413b is curved in an arc shape and is formed to extend obliquely with respect to the normal to the outer edge of the base portion 413a. In this embodiment, the multiple heat dissipation fins 413b are arranged alternately in the circumferential direction along the central axis O, with long fins and short fins alternating.

[0058] The shroud 42 houses the wavelength conversion wheel 41. The shroud 42 has an outer peripheral wall 420 that covers the outer circumference of the wavelength conversion wheel 41, a first cover 421 connected to one axial end (+X side) of the outer peripheral wall 420, a second cover 422 connected to the other axial end (-X side) of the outer peripheral wall 420, and an opening 423 that opens a part of the outer peripheral wall 420. The outer peripheral wall 420 may be integrally formed with either the first cover 421 or the second cover 422, or the first cover 421 and the second cover 422 may be formed as separate parts. The outer shape of the shroud 42 consists of a circular portion formed along the outer circumference of the wavelength conversion wheel 41 and a linear portion extending toward the opening 423.

[0059] In this embodiment, the shroud 42 has a light-transmitting portion 426 that transmits light that is incident on the wavelength conversion element 412 of the wavelength conversion wheel 41, and is reflected by the wavelength conversion wheel 41 and emitted from the wavelength conversion element 412.

[0060] The light-transmitting portion 426 is located on the optical path of the light rays BLs that are focused by at least the first focusing optical system 26 in the portion of the first cover 421 of the shroud 42 that faces the wavelength conversion element 412. The light-transmitting portion 426 emits the fluorescent YL generated by the wavelength conversion element 412 (see Figure 3). Alternatively, the light-transmitting portion 426 may be made of the pickup lens 26b of the first light-gathering optical system 26. Or, the light-transmitting portion 426 may be omitted by making the entire first cover 421 of a light-transmitting material such as glass or plastic.

[0061] As shown in Figures 4 and 5, the second cover 422 of the shroud 42 has an opening 422a formed approximately in the center, and a fixing member 425 that extends radially inward from the outer peripheral edge of the opening 422a and overlaps the opening 422a in the axial direction.

[0062] In this embodiment, the wavelength conversion wheel 41 is configured such that the rotation drive unit 419 protrudes to the outside of the shroud 42 through the opening 422a. The wavelength conversion wheel 41 is held in place by the shroud 42 by the rotation drive unit 419 being fixed to the fixing member 425 of the second cover 422 via a screw member 424.

[0063] As shown in Figure 6, when viewed from the axial direction, the outer circumferential wall 420 of the shroud 42 is circular in shape. The central axis O of the wavelength conversion wheel 41 is eccentric with respect to the center of the outer circumferential wall 420 towards the opening 423. The gap S between the wavelength conversion wheel 41 and the outer circumferential wall 420 widens as it approaches the opening 423.

[0064] In this embodiment, the wavelength conversion wheel 41 rotates the wheel substrate 411 around a central axis O, and the multiple heat dissipation fins 413b cause air drawn in from the radially inside of the wheel substrate 411 to be directed radially outward by centrifugal force. In other words, the wavelength conversion wheel 41 generates an airflow K that flows from the radially inside to the radially outside by drawing in air through the opening 422a of the shroud 42 as the wheel substrate 411 rotates. The heat dissipation member 413 generates an airflow K that flows from the radially inside to the radially outside of the base portion 413a, regardless of the shape of the heat dissipation fins 413b or the rotation direction of the base portion 413a.

[0065] As the wheel substrate 411 rotates in the direction indicated by arrow A, airflow K is sent out from the opening 423 of the shroud 42. In addition, a portion of the airflow K is collected in the wind tunnel formed by the gap between the outer peripheral wall 420 and the wheel substrate 411 and sent to the outside through the opening 423.

[0066] In this embodiment, the wavelength conversion wheel 41 dissipates heat from the wavelength conversion element 412 formed on the wheel substrate 411 by an airflow K flowing between a plurality of heat dissipation fins 413b as the wheel substrate 411 rotates. In this embodiment, the airflow K heated by cooling the wheel substrate 411 is discharged from the shroud 42 via the first duct 43, thereby suppressing the temperature rise inside the shroud 42. In addition, the airflow K generated by the heat dissipation member 413 is also used to cool the rotation drive unit 419 attached to the center of the base portion 413a.

[0067] As shown in Figure 4, the first duct 43 is provided at the opening 423 of the shroud 42 and discharges the airflow K generated by the wavelength conversion wheel 41 from the shroud 42. The first duct 43 is made up of a cylindrical member and has an inlet 43a and an outlet 43b. The inlet 43a of the first duct 43 is located at the opening 423 of the shroud 42. The heat exchanger 44 is located at the outlet 43b of the first duct 43 and the airflow K discharged from the outlet 43b flows through it.

[0068] In this embodiment, the area of ​​the outlet 43b is larger than the area of ​​the inlet 43a. The first duct 43 has a shape in which the cross-sectional area gradually increases from the inlet 43a to the outlet 43b. The outlet 43b has the same external shape as the heat exchanger 44. In this way, the first duct 43 is able to supply airflow K to the entire heat exchanger 44 by increasing the area of ​​the outlet 43b.

[0069] In this embodiment, the heat exchanger 44 is composed of, for example, a radiator. The heat exchanger 44 absorbs heat from the airflow K by exchanging heat between the heat exchange liquid flowing into it and the airflow K. This cools the wavelength conversion element 412 of the wavelength conversion wheel 41, thereby lowering the temperature of the heated airflow K.

[0070] As shown in Figure 4, the airflow K that flows through the heat exchanger 44 flows into the fan 46. The fan 46 draws in the airflow K from the downstream side of the heat exchanger 44 and supplies it to the second duct 45. The fan 46 in this embodiment is a centrifugal fan. The fan 46 has an intake port 46a and an exhaust port 46b. The intake port 46a is perpendicular to the rotation axis O1 of the fan 46 and faces the heat exchanger 44. The exhaust port 46b opens in a direction perpendicular to the rotation axis O1 (-X direction) and communicates with the second duct 45.

[0071] As shown in Figure 4, the second duct 45 guides the airflow K that has flowed through the heat exchanger 44 and fan 46 to the heat dissipation member 413 of the wavelength conversion wheel 41. The second duct 45 is a substantially cylindrical member that extends from the fan 46 toward the shroud 42 and has an inlet 45a and an outlet 45b. The inlet 45a of the second duct 45 is connected to the exhaust port 46b of the fan 46. The outlet 45b of the second duct 45 is connected to the shroud 42 so as to close the opening 422a formed in the second cover 422.

[0072] In this embodiment, the second duct 45 guides the airflow K to the center of the heat dissipation member 413 formed on the wheel substrate 411 through the opening 422a. The airflow K supplied from the second duct 45 flows from the radially inner side to the radially outer side of the wheel substrate 411 by the heat dissipation member 413, thereby cooling the wavelength conversion element 412 formed on the wheel substrate 411.

[0073] As described above, the wavelength conversion unit 40 of this embodiment rectifies the airflow K directed radially outward by the rotation of the wavelength conversion wheel 41 at the outer peripheral wall 420 of the shroud 42 and concentrates it at the opening 423, thereby increasing the discharge pressure of the airflow K from the opening 423. Then, by circulating the airflow K, whose temperature has decreased via the heat exchanger 44, to the heat dissipation member 413 of the wavelength conversion wheel 41 housed in the shroud 42, a wavelength conversion unit 40 with improved cooling efficiency can be provided. Therefore, the wavelength conversion unit 40 of this embodiment suppresses the temperature rise of the wavelength conversion element 412, thereby increasing the conversion efficiency of fluorescent YL and enabling the generation of bright fluorescent YL.

[0074] Furthermore, the wavelength conversion unit 40 of this embodiment is further equipped with a fan 46 that draws in the airflow K that has flowed through the heat exchanger 44 and supplies it to the second duct 45.

[0075] With this configuration, the cooling efficiency of the airflow K by the heat exchanger 44 can be increased by assisting the inflow of airflow K into the heat exchanger 44 through suction by the fan 46. In addition, the cooling efficiency of the heat dissipation fins 413b of the wavelength conversion wheel 41 can be increased by increasing the flow velocity of the airflow K supplied from the second duct 45 to the wavelength conversion wheel 41 by the fan 46.

[0076] Furthermore, the fan 46 in the wavelength conversion unit 40 of this embodiment is a centrifugal fan having an intake port 46a facing the heat exchanger 44 and an exhaust port 46b opening in a direction perpendicular to the rotation axis O1.

[0077] With this configuration, by making the intake and exhaust directions of the airflow K in the fan 46 90 degrees apart, the length of the second duct 45 connecting the fan 46 and the shroud 42 can be shortened. Therefore, an increase in the size of the wavelength conversion unit 40 can be suppressed.

[0078] Furthermore, in the wavelength conversion unit 40 of this embodiment, the shroud 42 further has a light-transmitting portion 426 that transmits light to the wavelength conversion element 412 of the wavelength conversion wheel 41 and transmits the fluorescent YL emitted from the wavelength conversion element 412. This configuration provides a wavelength conversion unit 40 that efficiently cools the reflective wavelength conversion wheel 41 housed within the shroud 42.

[0079] The light source device 2 of this embodiment includes a wavelength conversion unit 40 and a light source 21 that irradiates the wavelength conversion unit 40 with light rays BLs.

[0080] According to the light source device 2 of this embodiment, a sealed circulating wavelength conversion unit 40 with improved cooling efficiency is provided, which enables the generation of bright illumination light WL.

[0081] The projector 1 of this embodiment includes a light source device 2, optical modulators 4B, 4G, and 4R that modulate the light emitted from the light source device 2 based on an image signal, and a projection optical device 6 that projects the light modulated by the optical modulators 4B, 4G, and 4R.

[0082] According to the projector 1 of this embodiment, a projector with excellent display quality can be realized by modulating a bright illumination light WL.

[0083] (Second Embodiment) A second embodiment of the present invention will now be described. The basic configuration of the wavelength conversion unit in the second embodiment is the same as in the first embodiment, except that the fan is omitted. Therefore, the same reference numerals are used for basic components common to both the first and second embodiments, and their details will not be described.

[0084] Figure 7 is a perspective view showing the schematic configuration of the wavelength conversion unit 140 of this embodiment. As shown in Figure 7, the wavelength conversion unit 140 of this embodiment includes a wavelength conversion wheel 41, a shroud 42, a first duct 43, a heat exchanger 44, and a second duct 145.

[0085] In this embodiment, the airflow K that has flowed through the heat exchanger 44 flows into the second duct 145. The second duct 145 guides the airflow K that has flowed through the heat exchanger 44 to the wavelength conversion wheel 41 housed in the shroud 42.

[0086] The second duct 145 in this embodiment is composed of a first section 1451, a second section 1452, and a third section 1453. The first section 1451 has an inlet 1451a and is connected to the heat exchanger 44. The second section 1452 has an outlet 1452a and is connected to an opening 422a (see Figure 4) formed in the second cover 422 of the shroud 42. The third section 1453 is a section that connects the first section 1451 and the second section 1452, which are located at different positions in the Z-axis direction. One end of the third section 1453 is connected to the lower end (-X side end) of the first section 1451, and the other end of the third section 1453 is connected to the upper end (+X side end) of the second section 1452.

[0087] In the wavelength conversion unit 140 of this embodiment, the wavelength conversion wheel 41 can be efficiently cooled without using a fan 46 by actively utilizing the discharge pressure of the airflow K, which is increased by rectifying the airflow at the outer peripheral wall 420 of the shroud 42. Furthermore, by omitting the fan 46, a smaller wavelength conversion unit 140 can be provided.

[0088] (Third embodiment) A third embodiment of the present invention will now be described. The basic configuration of the wavelength conversion unit in the third embodiment is the same as in the first embodiment, except that the position of the fan is different from that of the first embodiment. Therefore, the same reference numerals are used for basic components common to both the first embodiment and the third embodiment, and their details will not be described.

[0089] Figure 8 is a perspective view showing the schematic configuration of the wavelength conversion unit 240 of this embodiment. As shown in Figure 8, the wavelength conversion unit 240 of this embodiment includes a wavelength conversion wheel 41, a shroud 42, a first duct 243, a heat exchanger 44, a second duct 45, and a fan 46.

[0090] In the first duct 243 of this embodiment, the areas of the outlet and the inlet are equal. Therefore, the first duct 243 of this embodiment is capable of supplying airflow K to a portion of the heat exchanger 44.

[0091] In this embodiment, the second duct 45 has an opening 47a in the side wall 47 near the connection point with the shroud 42. The second duct 45 supplies a portion of the airflow K sent from the fan 46 into the housing of the light source device 2 through the opening 47a. The airflow K sent from the fan 46 is cooled by passing through the heat exchanger 44.

[0092] Therefore, with the light source device using the wavelength conversion unit 240 of this embodiment, a cold airflow K can be supplied to the inside of the light source device by the second duct 45. The airflow K supplied to the inside of the light source device from the opening 47a of the second duct 45 lowers the temperature inside the light source device. This suppresses thermal damage and deformation of other optical components arranged inside the light source device, such as the polarization separation element 25, the first focusing optical system 26, and the second focusing optical system 29.

[0093] Furthermore, in the wavelength conversion unit 240 of this embodiment, a portion of the heat exchanger 44 is exposed from the first duct 243. Therefore, the portion of the heat exchanger 44 exposed from the first duct 243 can expel the waste heat from inside the light source device by the suction force of the fan 46. The waste heat from inside the light source device expelled by the heat exchanger 44 is cooled by the heat exchanger 44 and reused to cool the wavelength conversion wheel 41 or the inside of the light source device.

[0094] Thus, according to the wavelength conversion unit 240 of this embodiment, the heat resistance of the light source device can be further enhanced by suppressing the temperature rise inside the light source device, thereby suppressing thermal damage and deformation of optical components. The first duct 243 may be formed integrally with the members constituting the shroud 42.

[0095] (Fourth Embodiment) A fourth embodiment of the present invention will now be described. The basic configuration of the wavelength conversion unit in the fourth embodiment is the same as in the first embodiment, except that the position of the fan is different from that of the first embodiment. Therefore, the same reference numerals are used for basic components common to both the first embodiment and the fourth embodiment, and their details will not be described.

[0096] Figure 9A is a plan view showing the schematic configuration of the wavelength conversion unit 340 of this embodiment. Figure 9B is a side view showing the schematic configuration of the wavelength conversion unit 340 of this embodiment. Note that Figure 9A is a view of the wavelength conversion unit 340 from the -X side, and Figure 9B is a side view of the wavelength conversion unit 340 from the -Z side.

[0097] As shown in Figures 9A and 9B, the wavelength conversion unit 340 of this embodiment comprises a wavelength conversion wheel 41, a shroud 42, a first duct 43, a heat exchanger 44, a second duct 345, a fan 46, and a third duct 48. In this embodiment, the rotation axis O1 of the fan 46 is set in a direction perpendicular to the flow direction of the airflow K in the heat exchanger 44 (direction along the Y-axis) (Z-axis direction). The third duct 48 guides the airflow K from the heat exchanger 44 to the fan 46. In the fan 46 of this embodiment, the intake port 46a communicates with the third duct 48, and the exhaust port 46b communicates with the inlet 345a of the second duct 345. The outlet 345b of the second duct 345 is connected to the shroud 42 so as to close the opening 422a formed in the second cover 422.

[0098] According to the wavelength conversion unit 340 of this embodiment, the inclusion of a third duct 48 increases the degree of freedom in the layout of the fan 46 relative to the heat exchanger 44. Furthermore, since the outer shape of the fan 46 does not protrude to the +Z side relative to the heat exchanger 44, as in the layout of the first embodiment, the dimensions in the Z-axis direction can be reduced compared to the layout of the first embodiment.

[0099] Although one embodiment of the present invention has been described as an example, the present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0100] For example, although a reflective wavelength conversion unit was given as an example in the above embodiment, the optical element unit of the present invention is also applicable to a transmissive wavelength conversion unit. Below, a transmissive wavelength conversion unit will be described as the first modified example.

[0101] (First variation) Figure 10 is a cross-sectional view showing the main components of the wavelength conversion unit 40A of this modified example. Basic components common to the first embodiment are denoted by the same reference numerals, and their details are omitted from the description. As shown in Figure 10, in the wavelength conversion unit 40A of this modified example, the wavelength conversion element 412 is attached to the radially outer side of the wheel substrate 411A of the wavelength conversion wheel 41A via a fixing member (not shown). A heat dissipation member 413 is provided on the side of the wheel substrate 411A facing the rotation drive unit 419.

[0102] In this modified example, the shroud 42A further includes a light injector 427 that injects excitation light EL into the wavelength conversion element 412 of the wavelength conversion wheel 41A, and a light emission section 428 that transmits and emits fluorescence YL emitted from the wavelength conversion element 412 of the wavelength conversion wheel 41A in the opposite direction to the light injector 427.

[0103] According to the wavelength conversion unit 40A of this modified example, by efficiently cooling the transmissive wavelength conversion wheel 41A housed in the shroud 42A, the temperature rise of the wavelength conversion element 412 is suppressed, thereby increasing the conversion efficiency of fluorescent YL and generating bright fluorescent YL.

[0104] For example, in the above embodiment, the case in which the optical element unit of the present invention is applied to a wavelength conversion unit was given as an example, but the optical element unit of the present invention can also be applied to a diffusion unit in which a diffusion element (optical element) is formed on a wheel substrate in place of the wavelength conversion element 412. A second modified example, a diffusion element unit, will be described below.

[0105] (Second variation) Figure 11 is a cross-sectional view showing the main components of the diffusion element unit 50 of this modified example. Basic components common to the first embodiment are denoted by the same reference numerals, and their details are omitted from the description.

[0106] As shown in Figure 11, the diffusion element unit (optical element unit) 50 of this modified example comprises a diffusion reflection wheel (optical element wheel) 51, a shroud 42, and the first duct 43, heat exchanger 44, second duct 45, and fan 46 shown in Figure 1. The diffuse reflection wheel 51 comprises a wheel substrate 411, a diffusion element (optical element) 512, a heat dissipation member 413, and a rotation drive unit 419.

[0107] The diffusion element unit 50 of this modified example can be replaced, for example, with the diffusion reflective section 30 shown in Figure 1. According to the diffusion element unit 50 of this modified example, by efficiently cooling the diffusion reflective wheel 51 housed in the shroud 42, the temperature rise of the diffusion reflective element 512 can be suppressed, thereby preventing thermal damage and deformation of the diffusion reflective element 512. Furthermore, the diffusion element unit 50 can also be applied to a transmissive type diffusion element unit by adopting the same configuration as the wavelength conversion unit 40A shown in Figure 10.

[0108] Furthermore, although the above embodiment illustrates a projector 1 equipped with three optical modulators 4R, 4G, and 4B, it is also possible to apply this to a projector that displays color images with a single optical modulator. Moreover, the optical modulator is not limited to the liquid crystal panel described above; for example, a digital mirror device can also be used.

[0109] Furthermore, while the above embodiment shows an example of applying the light source device according to the present invention to a projector, it is not limited to this. The light source device according to the present invention can also be applied to lighting fixtures such as automobile headlights. Furthermore, the shroud can be defined not only as a housing section, but also as a housing case and an air guide case.

[0110] An optical element unit according to an embodiment of the present invention may have the following configuration. An optical element unit according to one aspect of the present invention comprises: an optical element wheel having a heat dissipation member provided on one side of a wheel substrate, which causes airflow radially outward as the wheel substrate rotates; a housing section capable of housing the optical element wheel, having an outer peripheral wall covering the outer circumference of the optical element wheel and an opening that opens a part of the outer peripheral wall; a first duct provided at the opening of the housing section for discharging airflow generated by the optical element wheel from the housing section; a heat exchanger positioned at the outlet of the first duct for the airflow discharged from the outlet; and a second duct for guiding the airflow that has flowed through the heat exchanger to the heat dissipation member of the optical element wheel.

[0111] In one embodiment of the present invention, an optical element unit may further include a fan that draws airflow from the downstream side of the heat exchanger and supplies it to a second duct.

[0112] In one embodiment of the present invention, the optical element unit may have a fan that has an intake port perpendicular to the fan's rotation axis and facing the heat exchanger, and an exhaust port that opens in a direction perpendicular to the rotation axis and communicates with a second duct.

[0113] In one aspect of the present invention, the rotation axis of the fan is set in a direction perpendicular to the airflow direction in the heat exchanger, and the unit further comprises a third duct that guides the airflow from the heat exchanger to the fan, and the fan has an intake port communicating with the third duct and an exhaust port communicating with the second duct.

[0114] In one embodiment of the present invention, the optical element unit may further have an optical element provided on one side of the wheel substrate opposite to the other side, and the housing portion may further have a light-transmitting portion that allows light to be incident on the optical element of the optical element wheel and transmits the light that is reflected by the optical element wheel and emitted from the optical element.

[0115] In one embodiment of the present invention, the optical element unit may further include an optical element wheel, and the housing portion may further include a light inlet portion for injecting light into the optical element of the optical element wheel, and a light emission portion for transmitting and emitting light emitted from the optical element of the optical element wheel in the direction opposite to the light inlet portion.

[0116] In one embodiment of the present invention, the optical element of the optical element wheel may be configured to be a wavelength conversion element.

[0117] In one embodiment of the present invention, the optical element of the optical element wheel may be configured to be a diffusion element.

[0118] A light source device according to one aspect of the present invention may have the following configuration. A light source device according to one aspect of the present invention comprises an optical element unit according to the above aspect of the present invention and a light source for irradiating the optical element unit with light.

[0119] A projector according to one aspect of the present invention may have the following configuration. A projector according to one aspect of the present invention comprises a light source device according to the above aspect of the present invention, an optical modulator that modulates light from the light source device according to image information, and a projection optical device that projects the light modulated by the optical modulator. [Explanation of Symbols]

[0120] 1...Projector, 2...Light source device, 4B, 4G, 4R...Optical modulation device, 6...Projection optics device, 21...Light source, 40...Wavelength conversion unit (optical element unit), 41...Wavelength conversion wheel (optical element wheel), 42, 42A...Shroud (housing section), 43, 243...First duct, 44...Heat exchanger, 45, 145, 345...Second duct, 46...Fan, 46a...Intake port, 46b...Exhaust port, 48...Third duct, 5 0...Diffusion element unit (optical element unit), 51...Diffusion reflective wheel (optical element wheel), 411, 411A...Wheel substrate, 411a...Back side (one side), 411b...Front side (the other side), 412...Wavelength conversion element (optical element), 413...Heat dissipation member, 420...Outer peripheral wall, 423...Opening, 426...Light-transmitting part, 427...Light incident part, 428...Light emission part, 512...Diffusion element (optical element), K...Airflow, O1...Rotation axis.

Claims

1. An optical element wheel having a wheel substrate, an optical element provided on the wheel substrate, and at least one heat dissipation fin provided on one side of the wheel substrate, wherein the rotation of the wheel substrate causes airflow to flow radially outward, An outer peripheral wall covering the outer circumference of the optical element wheel, and an opening that opens up a part of the outer peripheral wall, A light-transmitting portion that allows light from the optical element to pass through, and a housing portion capable of housing the optical element wheel, The system comprises a radiator through which the airflow discharged from the opening flows in a first direction, through which the airflow flows in from the first direction, and through which the airflow can pass along the first direction. The airflow that flows out from the radiator in the first direction is redirected to a second direction intersecting the first direction, and the airflow redirected to the second direction is redirected to a third direction which is opposite to the first direction. The airflow whose direction has been changed in the third direction flows into the radiator from the third direction and flows out of the radiator in the third direction. As the wheel substrate rotates, the airflow whose direction has been changed in the third direction is taken into the at least one heat dissipation fin. An optical element unit characterized by the following features.

2. The first position of the radiator where the airflow discharged from the opening flows into the radiator from the first direction, and the second position of the radiator where the airflow flows into the radiator from the third direction, are different positions when viewed from the first direction. The optical element unit according to feature 1.

3. The optical element of the optical element wheel is a wavelength conversion element. The optical element unit according to claim 1 or 2, characterized by the above.

4. The optical element of the optical element wheel is a diffusion element. The optical element unit according to claim 1 or 2, characterized by the above.

5. An optical element unit according to any one of claims 1 to 4, The optical element unit comprises a light source that irradiates light onto the optical element unit, A light source device characterized by the following features.

6. The light source device according to claim 5, A light modulator that modulates light from the aforementioned light source device according to image information, The system comprises a projection optical device that projects light modulated by the aforementioned optical modulation device. projector.

Images