JP5659775B2 - Light source device and projector - Google Patents

Description

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

  Laser light sources are attracting attention as light sources for projectors. For example, the projector of Patent Document 1 includes a plurality of light sources that emit laser light as excitation light, and a plurality of phosphor layers arranged on a rotating disk. Each light source is turned on or off in conjunction with the rotation of the rotating disk so that only the excitation light corresponding to the excitation wavelength of each phosphor layer is irradiated to each phosphor layer.

JP 2010-85740 A

In the projector of Patent Document 1, since all of the laser light emitted from each light source is converted into fluorescence by the phosphor layer, fluorescence obtained in comparison with energy consumed for obtaining fluorescence. Is weak and energy use efficiency is low.
On the other hand, it is also conceivable to use laser light for image display instead of using only fluorescence for image display. However, since the laser light is coherent light, a speckle pattern called speckle generated by interference is displayed on the screen, which causes a reduction in display quality.

  The present invention has been made in view of such circumstances, and provides a light source device and a projector that have high energy use efficiency and can suppress display quality deterioration (speckle noise) due to speckle. The purpose is to do.

In order to solve the above problems, a light source device according to the present invention includes a light-transmitting base material, a phosphor layer including a plurality of phosphor particles provided inside the base material, and excitation of the phosphor particles. A first light source that emits excitation light including a wavelength, a second light source that emits laser light having a wavelength different from the excitation wavelength, and a region of the phosphor layer that is irradiated with the laser light varies with time. And the phosphor layer is excited by the excitation light to emit fluorescence and scatters and emits the laser light.
In order to solve the above problems, a light source device according to the present invention includes a light-transmitting base material, a phosphor layer including a plurality of phosphor particles provided inside the base material, and excitation of the phosphor particles. A first light source that emits excitation light including a wavelength, a second light source that emits laser light having a wavelength different from the excitation wavelength, and a region of the phosphor layer that is irradiated with the laser light varies with time. And a driving device to be provided.

In the projector of Patent Document 1, as described above, since all the laser light emitted from each light source is converted into fluorescence by the phosphor layer, energy loss due to wavelength conversion occurs. However, according to the present invention, since the second light (laser light) includes a wavelength different from the excitation wavelength of the phosphor particles, the second light is emitted from the phosphor layer without being converted into fluorescence by the phosphor layer. Therefore, the energy use efficiency of the light source device according to the present invention is higher than the energy use efficiency of the light source device of Patent Document 1 in which each laser beam is converted into fluorescence in each phosphor layer.
Furthermore, according to the present invention, since the plurality of phosphor particles are included in the base material constituting the phosphor layer, the second light (laser light) incident on the phosphor layer is caused by the plurality of phosphor particles. Scattered. Since the scattered second light is less likely to cause interference, speckle generation is suppressed. Moreover, since the area | region where the 2nd light of a fluorescent substance layer is irradiated fluctuates temporally, the pattern of the speckle formed with the 2nd light inject | emitted from a fluorescent substance layer also changes temporally. Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized.
Therefore, it is possible to provide a light source device that has high energy utilization efficiency and suppresses display quality deterioration (speckle noise) due to speckle.

  In the light source device, the phosphor layer may scatter and emit a part of the excitation light incident on the phosphor layer by the plurality of phosphor particles.

  According to this light source device, since the excitation light incident on the phosphor layer is scattered, interference does not easily occur in the excitation light. Therefore, speckle noise is more effectively suppressed.

  In the light source device, the phosphor layer may be provided around a predetermined rotation axis of a rotating substrate, and the driving device may include a motor that rotates the phosphor layer around the predetermined rotation axis. Good.

  According to this light source device, speckle noise can be suppressed with a simple configuration when rotating the phosphor layer.

  In the light source device, the driving device may include a piezoelectric element that applies vibration to the phosphor layer in a direction intersecting a thickness direction of the phosphor layer.

  According to this light source device, speckle noise can be suppressed with a simple configuration when the phosphor layer is vibrated.

  In the light source device, a plurality of filler particles may be provided inside the base material.

  According to this light source device, the laser light incident on the phosphor layer is scattered not only by the plurality of phosphor particles but also by the plurality of filler particles. Therefore, speckle noise is more effectively suppressed compared to a configuration that does not include filler particles. Further, as a configuration for effectively suppressing speckle noise, it is conceivable to increase the number of phosphor particles, but it is difficult to extract a desired amount of fluorescence. Therefore, by using a configuration including a plurality of filler particles instead of increasing the number of phosphor particles, speckle noise can be effectively suppressed while taking out a desired amount of fluorescence.

  In the light source device, an area of the excitation light irradiation spot in the phosphor layer is substantially equal to an area of the laser light irradiation spot in the phosphor layer, and at least the excitation light irradiation spot in the phosphor layer. A part of the phosphor layer may overlap an irradiation spot of the laser beam.

  According to this light source device, since the fluorescence emitted from the phosphor layer and the laser light transmitted through the phosphor layer can be guided to the illumination optical system or the like by one collimating optical system, the light use efficiency is high, In addition, a small light source device can be realized.

  In the light source device, a wavelength selection that transmits the excitation light and the laser light and reflects the fluorescence emitted from the phosphor layer on a surface of the phosphor layer on which the excitation light and the laser light are incident. A reflective film may be disposed.

  According to this light source device, since the fluorescence backscattered light can be reflected forward while transmitting the excitation light and the laser light, the light use efficiency can be enhanced.

  The light source device may further include a light diffusion portion provided on an optical path of the laser light between the second light source and the phosphor layer.

  According to this light source device, the laser light is doubly diffused by the light diffusion portion and the phosphor layer, so that speckle noise can be more reliably suppressed.

  In the light source device, the laser light may be red light.

  The human eye has different light intensity (visibility) for each wavelength, and the red visibility is higher than the blue visibility, so red speckles are more visible than blue speckles. . Therefore, the light source device in which speckle noise is suppressed can be realized by using red light as the laser light.

  The projector according to the present invention includes the light source device described above, a light modulation device that modulates light emitted from the light source device according to image information, and a projection optical system that projects the modulated light from the light modulation device as a projection image. And.

  According to this projector, since the light source device described above is provided, it is possible to provide a projector that can reduce energy loss and suppress speckle noise.

It is a schematic diagram which shows the optical system of the projector which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the light source array which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the rotating fluorescent screen which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the fluorescent substance layer which concerns on 1st Embodiment of this invention. It is a figure which shows the emission spectrum of the fluorescent substance layer which concerns on 1st Embodiment of this invention. It is a figure which shows the reflective characteristic of the wavelength selection reflection film which concerns on 1st Embodiment of this invention. It is a schematic diagram which shows the light source device which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the vibration fluorescent plate which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the light source device which concerns on 3rd Embodiment of this invention. It is a schematic diagram which shows the light-diffusion part which concerns on 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

  In the following description, the XYZ rectangular coordinate system shown in FIG. 1 is set, and each member will be described with reference to this XYZ rectangular coordinate system.

(First embodiment)
FIG. 1 is a schematic diagram showing an optical system of a projector 1000 according to the first embodiment of the present invention. In FIG. 1, reference numeral 100ax denotes an illumination optical axis (the optical axis of light emitted from the light source device 1 toward the color separation light guide optical system 200). A direction parallel to the illumination optical axis is taken as a Y-axis. The optical axis refers to a virtual light beam that is representative of a light beam that passes through the entire system in the optical system.

  As shown in FIG. 1, the projector 1000 includes a light source device 1, a color separation light guide optical system 200, three liquid crystal light modulation devices 400R, 400G, and 400B as light modulation devices, a cross dichroic prism 500, and projection optics. And a system 600.

  The light source device 1 includes a first light source array 10, a second light source array 20, a condensing optical system 30, a rotating fluorescent plate 40, a collimating optical system 50, and an illumination optical system 100. Yes.

  The first light source array 10 emits excitation light as the first light. The first light is blue light composed of laser light.

  FIG. 2 is a schematic diagram showing the first light source array 10 according to the first embodiment of the present invention. FIG. 2A is a side view of the first light source array 10, and FIG. 2B is a front view of the first light source array 10.

  As shown in FIG. 2, the first light source array 10 includes a base body 11 and a plurality of first light sources 12 arranged on the base body 11 (see FIG. 2A). As the first light source 12, a solid-state light source such as a laser light source or a light emitting diode (LED) is used. In the present embodiment, the first light source 12 is a laser light source that emits blue light (emission intensity peak: about 445 nm) made of laser light as excitation light. Note that a light source that emits blue light having a wavelength other than 445 nm may be used as the light source. Although nine first light sources 12 are arranged on the base 11 in three rows and three columns, the number of the first light sources 12 is not limited to nine and can be changed as appropriate.

  A plurality of first light sources 12 are arranged in the first light source array 10 at equal intervals along the first direction (X direction) when viewed from the first light emission direction (+ Y direction). They are arranged at equal intervals along a second direction (Z direction) orthogonal to the direction 1 (see FIG. 2B). The arrangement interval of the plurality of first light sources 12 arranged along the first direction is the same as the arrangement interval of the plurality of first light sources 12 arranged along the second direction.

  Similarly to the first light source array 10, the second light source array 20 includes a base 21 and a plurality of second light sources 22 arranged on the base 21 (see FIG. 2A). As the second light source 22, a solid-state light source such as a laser light source or a light emitting diode (LED) is used. In the present embodiment, the second light source 22 is a laser light source that emits red light (peak of emission intensity: about 635 nm) as laser light. Note that a light source that emits red light having a wavelength other than 635 nm may be used as the light source. Although the nine second light sources 22 are arranged on the base 21 in three rows and three columns, the number of the second light sources 22 is not limited to nine and can be appropriately changed.

  As shown in FIG. 1, the condensing optical system 30 includes a second light beam on the optical path of the first light between the light source array 10 and the rotating fluorescent plate 40 and the second light beam between the light source array 20 and the rotating fluorescent plate 40. It is arranged on the optical path. The condensing optical system 30 includes a collimating lens 31, a collimating lens 32, and a condensing lens 33. The collimating lens 31 is composed of a plurality of convex lenses, and each convex lens is arranged at a position corresponding to each laser light source of the first light source array 10. On the other hand, the collimating lens 32 is also composed of a plurality of convex lenses, and each convex lens is arranged at a position corresponding to each laser light source of the second light source array 20. The condenser lens 33 is a convex lens. The collimating lens 31 causes the excitation light to enter the condensing lens 33 in a substantially collimated state. On the other hand, the collimating lens 32 causes the laser light to enter the condensing lens 33 in a substantially collimated state. The condenser lens 33 causes the excitation light and the laser light to enter the rotating fluorescent plate 40 in a substantially condensed state.

  FIG. 3 is a schematic view showing the rotating fluorescent plate 40 according to the first embodiment of the present invention. FIG. 3A is a side view of the rotating fluorescent plate, and FIG. 3B is a front view of the rotating fluorescent plate 40. The rotating fluorescent plate 40 is configured to be rotatable around a central axis CL1.

  As shown in FIG. 3, the rotating fluorescent plate 40 includes a disk (rotating substrate) 41, a phosphor layer 42, and a wavelength selective reflection film 43. In a part of the disc 41, a single phosphor layer 42 is continuously formed around the central axis CL1. A wavelength selective reflection film 43 is provided between the disc 41 and the phosphor layer 42. The rotating fluorescent plate 40 is arranged so that the surface of the disc 41 on which the phosphor layer 42 is not formed faces the condensing optical system 30 side. The phosphor layer 42 is disposed at the focal position of the first light and the second light collected by the condensing optical system 30.

  The disc 41 is made of a light transmissive material that transmits both the first light and the second light. For example, quartz glass, crystal, sapphire, transparent resin, or the like can be used. In particular, quartz glass, quartz, and sapphire, which are inorganic materials, are preferably used so as not to be deformed by heating with the first light and the second light.

  The phosphor layer 42 is excited by the first light (blue light) out of the first light condensed by the condensing optical system 30 and the second light condensed by the condensing optical system 30, and is blue. The light is converted into green light and emitted toward the collimating optical system 50.

FIG. 4 is a schematic view showing a phosphor layer according to the first embodiment of the present invention.
As shown in FIG. 4, the phosphor layer 42 is made of a light-transmitting base material 421, a plurality of phosphor particles 422 that emit third light (fluorescence), and a light-transmitting particulate material. A plurality of filler particles 423. The refractive index of the phosphor particles 422 and the refractive index of the filler particles 423 are different from the refractive index of the base material 421, and a plurality of phosphor particles 422 and a plurality of filler particles 423 are included inside the base material 421. Therefore, the first light and the second light are scattered by the phosphor layer 42.

  As a material for forming the base material 421, a light-transmitting resin material can be used, and among them, a silicone resin having a high heat resistance (refractive index: about 1.4) can be preferably used.

The phosphor particles 422 are particulate fluorescent substances that absorb excitation light emitted from the first light source 12 shown in FIG. 1 and emit fluorescence. For example, the phosphor particles 422 include a substance that emits fluorescence when excited by blue light having a wavelength of about 445 nm, and a part of the excitation light emitted from the first light source 12 has a green wavelength band. It is converted into light and emitted. As such phosphor particles 422, those having an average particle diameter of about 1 μm to several tens of μm are known to exhibit high luminous efficiency. As the phosphor particles 422, a commonly known YAG (yttrium, aluminum, garnet) phosphor can be used. For example, a YAG phosphor having a composition represented by (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce having an average particle diameter of 10 μm (refractive index: about 1.8) can be used.

  Note that the material for forming the phosphor particles 422 may be one type, or a mixture of particles formed using two or more types of forming materials may be used as the phosphor particles 422.

  The filler particles 423 have a function of scattering the first light (excitation light) and the second light incident on the phosphor layer 42 and further the third light (fluorescence) emitted from the phosphor particles 422. Yes. The refractive index of the filler particles 423 is different from the refractive index of the base material 421. In addition, as a forming material of the filler particles 423, a wide variety of materials such as a resin material and an inorganic material can be used as long as they are light-transmitting particulate substances. Among them, an inorganic material having high heat resistance can be suitably used. For example, titanium oxide having an average particle diameter of 10 μm (refractive index: about 2.5) can be used.

  FIG. 5 is a diagram showing an emission spectrum of the phosphor layer according to the first embodiment of the present invention. In FIG. 5, the horizontal axis represents wavelength (nm) and the vertical axis represents emission intensity. However, the emission spectrum shown in FIG. 5 is standardized so that the maximum value of the emission intensity is 1. In FIG. 5, the left vertical line L1 is a line that separates the blue wavelength and the green wavelength (a line at a wavelength of 490 nm) in the projector of the present embodiment, and the right line L2 is a green line in the projector of the present embodiment. It is a line (a line at a wavelength of 590 nm) that distinguishes the wavelength from the red wavelength.

  As shown in FIG. 5, the emission spectrum of the phosphor layer includes a wavelength of 480 to 730 nm. In this embodiment, light having a wavelength of 490 to 590 nm is used as the green light of the projector, and light having a wavelength of 490 nm or less and light having a wavelength of 590 nm or more are included in the wavelengths included in the emission spectrum of the phosphor layer. Do not use as green light. For the blue light of the projector, light having a wavelength of 490 nm or less out of the wavelengths included in the emission spectrum of the phosphor layer and the first light having a wavelength of 445 nm transmitted through the phosphor layer are mixed and used as blue light Is done. On the other hand, for the red light of the projector, the light having a wavelength of 590 nm or more out of the wavelengths included in the emission spectrum of the phosphor layer and the second light having a wavelength of 635 nm transmitted through the phosphor layer are mixed to produce red light. Used as.

  Returning to FIG. 3, the wavelength selective reflection film 43 is disposed on the surface of the phosphor layer 42 on the side on which the first light and the second light are incident. The wavelength selective reflection film 43 has wavelength selectivity that transmits the first light and the second light and reflects the third light excited by the first light. Such a wavelength selective reflection film 43 is formed of, for example, a dielectric multilayer film.

  FIG. 6 is a diagram showing the reflection characteristics of the wavelength selective reflection film according to the first embodiment of the present invention. In FIG. 6, the horizontal axis represents wavelength (nm) and the vertical axis represents reflectance.

  As shown in FIG. 6, the wavelength selective reflection film reflects almost 100% of light having a wavelength larger than 445 nm and smaller than 635 nm. In other words, the wavelength selective reflection film transmits light having a wavelength of 445 nm or less and light having a wavelength of 635 nm or more. In other words, the wavelength selective reflection film transmits the first light (wavelength 445 nm) and the second light (wavelength 635 nm), and reflects the third light (the range where the wavelength is larger than 445 nm and smaller than 635 nm).

  Returning to FIG. 3, the shaft of the motor 45 is fixed to the center of the disc 41, and the disc 45 can be rotated around the center axis CL <b> 1 by the motor 45. That is, the motor 45 functions as a drive device that temporally varies the region where the phosphor layer 42 is irradiated with the first light and the region where the phosphor layer 42 is irradiated with the second light. The motor 45 is driven at a predetermined rotational speed within the driving time. For this reason, the area | region where the light condensed with the condensing optical system 30 is irradiated to the disk 41 (phosphor layer 42) is not fixed to a specific area | region. Therefore, heat generated in the phosphor layer 42 by light irradiation can be dissipated in a wide region along the circumferential direction.

  Returning to FIG. 1, the collimating optical system 50 is disposed on the optical path of the first light, the optical path of the second light, and the optical path of the third light between the rotating fluorescent plate 40 and the illumination optical system 100. Has been placed. The collimating optical system 50 includes a first lens 51 and a second lens 52. The collimating optical system 50 causes the light emitted from the rotating fluorescent plate 40 (first light, second light, and third light) to enter the illumination optical system 100 (integrator optical system 110) in a substantially parallel state. .

  The illumination optical system 100 is disposed between the collimating optical system 50 and the color separation light guiding optical system 200. The illumination optical system 100 includes an integrator optical system 110, a polarization conversion element 120, and a superimposing lens 130.

  The integrator optical system 110 includes a first fly eye lens 111 and a second fly eye lens 112. The first fly-eye lens 111 and the second fly-eye lens 112 are each composed of a plurality of element lenses arranged in a matrix. The first fly-eye lens 111 has a function of dividing and individually condensing light (excitation light, laser light, and fluorescence) from the collimating optical system 50 by a plurality of element lenses constituting the first fly-eye lens 111. . The second fly-eye lens 112 has a function of emitting the divided light flux from the first fly-eye lens 111 with an appropriate divergence angle by a plurality of element lenses constituting the second fly-eye lens 112. The integrator optical system 110 uniformizes the light intensity distribution of the light synthesized by the collimating optical system 50.

  The polarization conversion element 120 is formed of an array having a PBS, a mirror, a retardation plate, etc. as a set of elements. The polarization conversion element 120 has a function of aligning the polarization direction of each partial light beam divided by the first fly-eye lens 111 with linear polarization in one direction.

  The superimposing lens 130 appropriately converges the illumination light passing through the polarization conversion element 120 as a whole, and enables superimposing illumination on the illuminated areas of the liquid crystal light modulation devices 400R, 400G, and 400B.

  The color separation light guide optical system 200 includes dichroic mirrors 210 and 220 and reflection mirrors 230, 240 and 250. The color separation light guide optical system 200 separates light (excitation light, laser light, and fluorescence) from the light source device 1 (illumination optical system 100) into red light, green light, and blue light, and red light, green light, and blue light. Each color light is guided to the liquid crystal light modulation devices 400R, 400G, and 400B to be illuminated. Condensing lenses 300R, 300G, and 300B are disposed between the color separation light guide optical system 200 and the liquid crystal light modulation devices 400R, 400G, and 400B.

  The dichroic mirrors 210 and 220 are mirrors in which a wavelength selective transmission film that reflects light in a predetermined wavelength region and transmits light in other wavelength regions is formed on a substrate. Specifically, the dichroic mirror 210 transmits a red light component and a green light component, and reflects a blue light component. The dichroic mirror 220 reflects the green light component and transmits the red light component.

  The reflection mirrors 230, 240, and 250 are mirrors that reflect incident light. Specifically, the reflection mirror 230 reflects the blue light component reflected from the dichroic mirror 210. The reflection mirrors 240 and 250 reflect the red light component transmitted through the dichroic mirror 220.

  The blue light reflected by the dichroic mirror 210 is reflected by the reflection mirror 230, passes through the condenser lens 300B, and enters the image forming area of the liquid crystal light modulation device 400B for blue light. The green light transmitted through the dichroic mirror 210 is reflected by the dichroic mirror 220, passes through the condenser lens 300G, and enters the image forming area of the liquid crystal light modulation device 400G for green light. The red light transmitted through the dichroic mirror 220 enters the image forming area of the liquid crystal light modulation device 400R for red light through the incident-side reflection mirror 240, the emission-side reflection mirror 250, and the condenser lens 300R.

  The reflection mirrors 240 and 250 have a function of guiding the red light component transmitted through the dichroic mirror 220 to the liquid crystal light modulation device 400R. Thereby, even if the length of the optical path of red light is longer than the length of the optical path of other color lights, the fall of the utilization efficiency of red light by the divergence of red light etc. can be suppressed. In addition, when the length of the optical path of other color light (for example, blue light) is longer than the length of the optical path of red light, the structure which arrange | positions a relay lens and a reflective mirror in the optical path of blue light is also considered.

  The liquid crystal light modulation devices 400R, 400G, and 400B form color images by modulating incident color light in accordance with image information, and are the illumination target of the light source device 1. Although not shown, incident-side polarizing plates are disposed between the condenser lenses 300R, 300G, and 300B and the liquid crystal light modulators 400R, 400G, and 400B, respectively. Further, an exit-side polarizing plate is disposed between each of the liquid crystal light modulation devices 400R, 400G, and 400B and the cross dichroic prism 500. The incident-side color light is modulated by the incident-side polarizing plate, the liquid crystal light modulation devices 400R, 400G, and 400B and the emission-side polarizing plate.

  For example, the liquid crystal light modulation devices 400R, 400G, and 400B are transmissive liquid crystal light modulation devices in which liquid crystal is hermetically sealed in a pair of transparent substrates, and a polysilicon TFT is used as a switching element in accordance with a given image signal. Modulates the deflection direction of one type of linearly polarized light emitted from an incident side polarizing plate (not shown).

  The cross dichroic prism 500 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from an exit side polarizing plate (not shown). The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded. A dielectric multilayer film is formed on the substantially X-shaped interface to which the right-angle prism is bonded. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

  The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form an image on the screen SCR.

According to the light source device 1 of the present embodiment, since the second light (laser light) includes a wavelength different from the excitation wavelength of the phosphor particles 422, the phosphor layer 42 is not converted into fluorescence by the phosphor layer 42. Is injected from. Therefore, the energy use efficiency of the light source device 1 of the present embodiment is higher than the energy use efficiency of the light source device of Patent Document 1 in which each laser beam is converted into fluorescence in each phosphor layer.
Furthermore, according to the light source device 1 of the present embodiment, since the plurality of phosphor particles 422 are included in the base material 421, the second light (laser light) incident on the phosphor layer 42 is a plurality of phosphors. Scattered by particles 422. Since the scattered second light is less likely to cause interference, speckle generation is suppressed. In addition, since the region of the phosphor layer 42 irradiated with the second light varies with time, the speckle pattern formed by the second light emitted from the phosphor layer 42 also varies with time. . Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized.
Therefore, it is possible to provide the light source device 1 with high energy utilization efficiency and suppressed speckle noise.

  In addition, according to this configuration, since the first light incident on the phosphor layer 42 is scattered, interference is less likely to occur in the first light as in the case of the second light. Therefore, speckle noise is more effectively suppressed.

  Further, according to this configuration, since the driving device includes the motor 45, speckle noise can be suppressed with a simple configuration when the phosphor layer 42 is rotated.

  Further, according to this configuration, since the plurality of filler particles 423 having a refractive index different from the refractive index of the base material 421 is included in the base material 421, the second light incident on the phosphor layer 42 is included. In addition to being scattered by the plurality of phosphor particles 422, it is also scattered by the plurality of filler particles 423. Therefore, speckle noise is more effectively suppressed compared to a configuration that does not include filler particles 423. Further, as a configuration for effectively suppressing speckle noise, it is conceivable to increase the number of phosphor particles, but it is difficult to extract a desired amount of fluorescence. Therefore, by using a configuration including a plurality of filler particles instead of increasing the number of phosphor particles, speckle noise can be effectively suppressed while taking out a desired amount of fluorescence.

  Further, according to this configuration, since the wavelength selective reflection film 43 is disposed on the surface on the phosphor layer 42 on which the first light and the second light are incident, the first light and the second light are arranged. The backscattered light of the third light can be reflected forward while passing through. Therefore, the light use efficiency can be increased.

  From the light source device 1 of this embodiment, fluorescence is emitted as green light, laser light emitted from the first light source array 10 is emitted as blue light, and red light is emitted from the second light source array 20 as red light. Laser light is emitted. Since fluorescence is not coherent light, speckles are not generated in green light, but speckles are generated because both blue light and red light are coherent light. The human eye has different light intensity (visibility) for each wavelength, and the red visibility is higher than the blue visibility, so red speckles are more visible than blue speckles. . Therefore, a light source device in which speckle noise is suppressed can be realized by using red light as the second light.

  According to the projector 1000 of the present embodiment, since the light source device 1 described above is provided, it is possible to provide the projector 1000 that can reduce energy loss and suppress speckle noise.

  In the light source device 1 of the present embodiment, the first light is blue light, the second light is red light, and the third light is green light. Not limited to this. For example, the present invention can be applied to a configuration in which the first light and the third light have the same color. Further, the present invention can also be applied to a configuration in which the second light and the third light have the same color.

  Moreover, in the light source device 1 of this embodiment, although the light source which inject | emits a laser beam was used as a 1st light source and a 2nd light source, it is not restricted to this. For example, a light source that emits light other than laser light may be used as the first light source, and a light source that emits laser light may be used as the second light source. That is, a light source that emits laser light may be used as at least the second light source.

  In the light source device 1 of the present embodiment, convex lenses are used as the first lens and the second lens in the collimating optical system, but the present invention is not limited to this. In short, it is only necessary that the collimating optical system enters the illumination optical system in a state in which the light scattered by the phosphor layer is substantially parallelized. Further, the number of lenses constituting the collimating optical system may be one, or may be three or more.

  Moreover, in the light source device 1 of this embodiment, although the fluorescent substance layer is formed along the rotation direction of a rotating substrate, it is not restricted to this. For example, the phosphor layer may be formed on the entire rotating substrate.

  In the light source device 1 of the present embodiment, the example in which the motor 45 is driven at a predetermined number of rotations within the driving time has been described, but the present invention is not limited thereto. For example, the rotational speed of the motor 45 may vary with time within the drive time.

  In the projector 1000 of this embodiment, three liquid crystal light modulation devices are used as the liquid crystal light modulation device, but the present invention is not limited to this. The present invention can also be applied to a projector using one, two, four or more liquid crystal light modulation devices.

  In the projector 1000 of the present embodiment, a transmissive projector is used, but the present invention is not limited to this. For example, a reflective projector may be used. Here, “transmission type” means that the light modulation device as the light modulation means is a type that transmits light, such as a transmission type liquid crystal display device. The “reflective type” means that a light modulation device as a light modulation unit, such as a reflection type liquid crystal display device, reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(Second Embodiment)
FIG. 7 is a schematic diagram showing a light source device 2 according to the second embodiment of the present invention.
As shown in FIG. 7, the light source device 2 according to the present embodiment is different from the light source device 1 according to the first embodiment described above in that a vibration fluorescent plate 140 is provided instead of the rotating fluorescent plate 40 described above. . That is, in the first embodiment described above, the drive device includes a motor, whereas the drive device of the present embodiment includes a piezoelectric element. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The light source device 2 includes a first light source array 10, a second light source array 20, a condensing optical system 30, a vibrating fluorescent plate 140, a collimating optical system 50, and an illumination optical system 100. Yes.

  FIG. 8 is a schematic view showing a vibrating fluorescent plate according to the second embodiment of the present invention. FIG. 8A is a side view of the vibrating fluorescent plate 140, and FIG. 8B is a front view of the vibrating fluorescent plate 140. In FIG. 8, symbol CL2 is the central axis of the vibrating fluorescent plate.

  As shown in FIG. 8, the vibrating fluorescent plate 140 includes a substrate 141, a phosphor layer 142, and a wavelength selective reflection film 143. A phosphor layer 142 is formed at the center of the substrate 141. A wavelength selective reflection film 143 is provided between the substrate 141 and the phosphor layer 142. The vibrating fluorescent plate 140 is disposed so that the surface of the substrate 141 on which the phosphor layer 142 is not formed faces the condensing optical system 30 side. The phosphor layer 142 is disposed at the focal position of the first light and the second light collected by the condensing optical system 30.

  The substrate 141 is formed of a light transmissive material that transmits the first light and the second light. The phosphor layer 142 is excited by the first light (blue light) out of the first light condensed by the condensing optical system 30 and the second light condensed by the condensing optical system 30, and blue The light is converted into green light and emitted toward the collimating optical system 50. The wavelength selective reflection film 143 has wavelength selectivity that transmits the first light and the second light and reflects the third light.

  The substrate 141 has a piezoelectric element 145 fixed to one end thereof, and can vibrate by the piezoelectric element 145. That is, the piezoelectric element 145 functions as a driving device that temporally varies a region where the phosphor layer 142 is irradiated with the first light and a region where the phosphor layer 142 is irradiated with the second light. The piezoelectric element 145 imparts vibration to the phosphor layer 142 in a direction that intersects the thickness direction of the phosphor layer 142 (a direction that intersects the central axis CL2, for example, the direction of the arrow shown in FIG. 8). The piezoelectric element 145 is driven with a predetermined amplitude of vibration within the driving time.

  According to the light source device 2 of the present embodiment, since the driving device includes the piezoelectric element 145, speckle noise can be suppressed with a simple configuration when the phosphor layer 142 is vibrated.

  In the light source device 2 of the present embodiment, the piezoelectric element 145 is described as being driven with a predetermined vibration amplitude within the driving time, but the present invention is not limited thereto. For example, the amplitude of vibration of the piezoelectric element 145 may vary with time within the driving time.

  In the light source device 2 of the present embodiment, the configuration in which one piezoelectric element 145 is disposed at one end of the substrate 141 has been described as an example, but the configuration is not limited thereto. For example, the number of piezoelectric elements arranged on the substrate 141 may be two or more. Further, the arrangement position of the piezoelectric elements arranged on the substrate 141 can be changed as appropriate.

(Third embodiment)
FIG. 9 is a schematic diagram showing a light source device 3 according to the third embodiment of the present invention.
As shown in FIG. 9, the light source device 3 according to the present embodiment includes a light diffusing unit 60 and a condensing optical system 70 on the optical path of the second light between the condensing optical system 30 and the rotating fluorescent plate 40. Are different from the light source device 1 according to the first embodiment described above. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The light source device 3 includes a first light source array 10, a second light source array 20, a condensing optical system 30, a light diffusing unit 60, a condensing optical system 70, a rotating fluorescent plate 40, a collimating optical system 50, And an illumination optical system 100.

  The light diffusing unit 60 diffuses the first light and the second light emitted from the condensing optical system 30 to generate diffused light, and emits the generated diffused light from the emission end face.

FIG. 10 is a schematic diagram showing a light diffusing unit 60 according to the third embodiment of the present invention.
As shown in FIG. 10, the light diffusing unit 60 is configured by dispersing diffusing particles 62 having light diffusibility in a base material 61 made of a light transmitting material such as a transparent resin. The diffusing particles 62 are dispersed in the base material 61 at positions where the light emitted from the condensing optical system 30 in the light diffusing unit 60 is collected. The thickness of this light diffusion part 60 (base material 61) is about 1-2 mm.

  Returning to FIG. 9, the condensing optical system 70 includes a first lens 71 and a second lens 72. The condensing optical system 70 condenses the first light and the second light diffused by the light diffusing unit 60 and causes the light to enter the rotating fluorescent plate 40 (phosphor layer 42).

  According to the light source device 3 of the present embodiment, the second light is doubly diffused by the light diffusing unit 60 and the phosphor layer 42, so speckle noise can be more reliably suppressed.

  Further, according to this configuration, the first light is also diffused twice by the light diffusing unit 60 and the phosphor layer 42, so that speckle noise can be more reliably suppressed.

  In the light source device 3 of the present embodiment, the configuration in which the light diffusing unit 60 is disposed on the optical path of the second light between the condensing optical system 30 and the rotating fluorescent plate 40 has been described as an example. Not limited to this. For example, the light diffusion unit 60 may be disposed on the optical path of the second light between the rotating fluorescent plate 40 and the illumination optical system 100.

  The present invention is applicable not only when applied to a front projection type projector that projects from the side that observes the projected image, but also when applied to a rear projection type projector that projects from the side opposite to the side that observes the projected image. can do.

  In each of the above embodiments, the example in which the light source device of the present invention is applied to a projector has been described, but the present invention is not limited to this. For example, the light source device of the present invention can be applied to other optical devices (for example, an optical disc device, a car headlamp, a lighting device, etc.).

DESCRIPTION OF SYMBOLS 1, 2, 3 ... Light source device, 12 ... 1st light source, 22 ... 2nd light source, 41 ... Disc (rotary substrate), 42, 142 ... Phosphor layer, 43, 143 ... Wavelength selective reflection film, 45 ... Motor (Driving device), 60 ... light diffusing section, 70 ... condensing optical system, 145 ... piezoelectric element (driving device), 400R, 400G, 400B ... liquid crystal light modulating device (light modulating device), 421 ... base material, 422 ... Phosphor particles, 423 ... filler particles, 600 ... projection optical system, 1000 ... projector

Claims (10)

A phosphor layer including a light-transmitting substrate and a plurality of phosphor particles provided inside the substrate;
A first light source that emits excitation light including an excitation wavelength of the phosphor particles;
A second light source that emits laser light including a wavelength different from the excitation wavelength;
A driving device that temporally varies a region of the phosphor layer irradiated with the laser light;
Equipped with a,
The phosphor layer is excited by the excitation light to emit fluorescence and scatters and emits the laser light .   2. The light source device according to claim 1, wherein the phosphor layer scatters and emits a part of the excitation light incident on the phosphor layer by the plurality of phosphor particles. 3. The phosphor layer is provided around a predetermined rotation axis of the rotating substrate,
The light source device according to claim 1, wherein the driving device includes a motor that rotates the phosphor layer around the predetermined rotation axis.   The light source device according to claim 1, wherein the driving device includes a piezoelectric element that applies vibration to the phosphor layer in a direction intersecting a thickness direction of the phosphor layer.   The light source device according to claim 1, wherein a plurality of filler particles are provided inside the base material. The area of the excitation spot of the excitation light in the phosphor layer is substantially equal to the area of the laser light irradiation spot in the phosphor layer,
The at least part of the irradiation spot of the excitation light in the phosphor layer is overlapped with the irradiation spot of the laser light in the phosphor layer. Light source device.   A wavelength selective reflection film that transmits the excitation light and the laser light and reflects the fluorescence emitted from the phosphor layer is disposed on a surface of the phosphor layer on which the excitation light and the laser light are incident. The light source device according to claim 1, wherein the light source device is a light source device.   The light source device according to claim 1, further comprising a light diffusing unit provided on an optical path of the laser light between the second light source and the phosphor layer.   The light source device according to claim 1, wherein the laser light is red light. The light source device according to any one of claims 1 to 9,
A light modulation device that modulates light emitted from the light source device according to image information;
A projection optical system that projects modulated light from the light modulation device as a projection image;
A projector comprising:

Images