JP5682813B2 - Lighting device and projector - Google Patents

Description

  The present invention relates to a lighting device and a projector.

  Laser light sources are attracting attention as light sources for projectors. 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. For this reason, in the image projection apparatus of Patent Document 1, the reflection element that reflects the laser light is vibrated in a direction parallel to the normal direction of the reflection surface, and the position on the screen where the speckle is displayed is changed over time. ing.

International Publication No. 06-098281 Pamphlet

  In the image projection apparatus of Patent Document 1, speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized. However, since the speckle itself is not reduced, the effect is limited.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an illumination device and a projector capable of reliably suppressing display quality deterioration (speckle noise) due to speckle. .

In order to solve the above-described problems, the illumination device of the present invention includes a first light source that emits first light, a second light source that emits second light, and the first light emitted by the first light source. A light combining optical system for combining the second light emitted from the second light source with the first light reflected by the reflection mirror, and a reflection mirror for reflecting the light. A driving device that temporally varies the shape of the reflecting surface of the reflecting mirror so that the shape of the surface undulates, and at least the first light source is a laser light source that emits laser light as the first light, The drive device includes a piezoelectric element that applies vibration to the reflection mirror in a thickness direction of the reflection mirror, and an amplitude of vibration of the piezoelectric element varies with time.
In order to solve the above-described problems, the illumination device of the present invention includes a first light source that emits first light, a second light source that emits second light, and the first light emitted by the first light source. A light combining optical system for combining the second light emitted from the second light source with the first light reflected by the reflection mirror, and a reflection mirror for reflecting the light. And a driving device that temporally varies the shape of the reflecting surface of the reflecting mirror so that the shape of the surface undulates, and at least the first light source is a laser light source that emits laser light as the first light. It is characterized by.

  According to this illuminating device, an uneven shape that undulates is formed on the reflection surface of the reflection mirror, so that the first light (laser light) incident on the reflection surface is diffused by the uneven shape of the reflection surface. Since the diffused first light is less likely to cause interference, the generation of speckle is suppressed. In addition, since the shape of the reflecting surface that reflects the first light (laser light) varies with time, the speckle pattern displayed on the screen varies with time. Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized. As described above, according to the lighting device of the present invention, speckle noise is suppressed by temporally changing the speckle pattern while suppressing generation of speckle. Therefore, the effect of suppressing speckle noise is higher than the configuration of Patent Document 1 in which speckle noise is suppressed by simply changing the position where speckle is displayed.

  In the illuminating device, on the optical path of the first light between the first light source and the reflection mirror, a first light diffusing unit that diffuses the first light emitted by the first light source; A collimating optical system that collimates the light diffused by the first light diffusing section and makes the light incident on the reflecting mirror may be disposed.

  According to this illumination device, the first light is doubly diffused by the first light diffusing unit and the reflection mirror, so that speckle noise can be more reliably suppressed.

  The said illuminating device WHEREIN: The said 1st light-diffusion part may be formed along the rotation direction of a rotation board | substrate.

  According to this illumination device, the position at which the first light is incident on the first light diffusing portion changes with time, so the speckle pattern formed by the first light emitted from the first light diffusing portion. Also changes over time. Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized. Therefore, speckle noise is more effectively suppressed.

  In the illuminating device, a second light diffusing unit that diffuses the first light may be disposed on the optical path of the first light reflected by the reflecting mirror.

  According to this illuminating device, the first light is doubly diffused by the second light diffusing unit and the reflecting mirror, so speckle noise can be more reliably suppressed.

  In the illumination device, the driving device may include a piezoelectric element that applies vibration to the reflection mirror in a thickness direction of the reflection mirror, and the amplitude of vibration of the piezoelectric element may vary with time.

  According to this illumination device, the shape of the reflecting surface of the reflecting mirror can be accurately controlled.

  In the illumination device, a plurality of the piezoelectric elements may be arranged at different positions around the reflection mirror, and the amplitude of vibration of each piezoelectric element may vary with time.

  According to this illuminating device, the shape of the reflecting surface of the reflecting mirror can be more freely controlled by variously combining the installation positions of the plurality of piezoelectric elements and the vibration amplitudes and phases of the plurality of piezoelectric elements.

  In the illumination device, the reflection mirror is a first wavelength selective reflection layer that transmits the second light emitted from the second light source in the same direction as the reflection direction of the first light reflected by itself. May be.

  According to this illumination device, the reflecting mirror can be used as a means for combining the first light and the second light. For this reason, the configuration is simplified as compared with the case where the combining means is provided separately from the reflecting mirror.

  The illumination device includes a third light source that emits third light, and the light combining optical system reflects the first light and the second light combined by the first wavelength selective reflection layer, A second wavelength selective reflection layer that transmits the third light emitted from the third light source and synthesizes the first light, the second light, and the third light. Good.

  According to this illuminating device, a light combining optical system capable of combining three types of light while suppressing speckle noise generated by the first light can be realized with a simple configuration.

  In the illumination device, the light combining optical system reflects the first light emitted from the first light source, transmits the second light emitted from the second light source, and transmits the first light. A third wavelength selective reflection layer for combining light and the second light, and the reflection mirror for reflecting the first light and the second light combined by the third wavelength selective reflection layer. You may have.

  According to this illumination device, both the first light and the second light are reflected by the reflection mirror. Therefore, even when the second light is a laser beam, the speckle generated by the second light does not greatly deteriorate the display quality.

  The illumination device includes a third light source that emits third light, and the reflection mirror reflects the first light and the second light synthesized by the three-wavelength selective reflection layer, and The third light emitted by three light sources may be transmitted to synthesize the first light, the second light, and the third light.

  According to this illuminating device, a light combining optical system capable of combining three types of light while suppressing speckle noise generated by the first light and the second light can be realized with a simple configuration.

  In the illumination device, the third light source includes an excitation light source that emits excitation light, and a phosphor layer that emits fluorescence when excited by the excitation light emitted by the excitation light source. The fluorescence may be emitted as

  According to this illuminating device, since the fluorescence is emitted as the third light by the third light source, it is possible to take out light without speckle noise.

  In the illumination device, the first light may be red light.

  It is known that the human eye has different intensities (specific luminous sensitivity) for sensing light for each wavelength, and in particular, the specific luminous sensitivity of red light is higher than that of blue. Therefore, the effect of suppressing speckle noise is enhanced when the first light is red light. For example, in addition to the first light being red light, the second light may be blue light and the third light may be green light. By such color selection, the green light with the highest relative visibility is not a laser beam, so speckles do not occur, and the red light with the next highest relative visibility is a reflection system, so the speckle reduction effect is significant. Become.

  The projector according to the present invention includes the above-described illumination device, a light modulation device that modulates light emitted from the illumination 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 illumination device described above is provided, a projector capable of reliably suppressing speckle noise can be provided.

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 1st light-diffusion part 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 reflective mirror and drive device which concern on 1st Embodiment of this invention. It is a schematic diagram which shows the illuminating device which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the reflective mirror and drive device which concern on 2nd Embodiment of this invention. It is a schematic diagram which shows the illuminating device which concerns on 3rd Embodiment of this invention. It is a schematic diagram which shows the illuminating device which concerns on 4th Embodiment of this invention. It is a schematic diagram which shows the illuminating device which concerns on 5th Embodiment of this invention. It is a schematic diagram which shows the illuminating device which concerns on 6th 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 illumination device 1 toward the color separation light guide optical system 200). 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 an illumination 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 illumination device 1 includes a first light source unit 10, a second light source unit 20, a third light source unit 30, a light combining optical system 80, and an illumination optical system 100.

  The first light source unit 10 emits blue light as the first light. The first light source unit 10 includes a first light source array 11, a condensing optical system 12, a diffuser (first light diffusing unit) 15, and a collimating optical system 16.

  FIG. 2 is a schematic diagram showing the light source array according to the first embodiment of the present invention. FIG. 2A is a side view of the first light source array, and FIG. 2B is a front view of the first light source array. In FIG. 2, the basic configuration of the light source array is shown, and the first light source array 11 constituting the first light source unit 10 is illustrated. In addition, nine first light sources 11a are arranged in three rows and three columns on the base 11b, but a plurality of the first light sources 11a may be arranged, and the number of arrangements can be changed as appropriate.

  As shown in FIG. 2, the first light source array 11 includes a base 11b and a plurality of first light sources 11a arranged on the base 11b (see FIG. 2A). As the 1st light source 11a, solid light sources, such as a laser light source and a light emitting diode (LED), are used. In the present embodiment, the first light source 11a is a laser light source that emits red light (emission intensity peak: about 610 nm) made of laser light as the first light. Note that a light source that emits red light having a wavelength other than 610 nm may be used as the light source.

  In the first light source array 11, a plurality of first light sources 11 a are arranged 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 11a arranged along the first direction is the same as the arrangement interval of the plurality of first light sources 11a arranged along the second direction.

  As shown in FIG. 1, the condensing optical system 12 is disposed on the optical path of the first light between the first light source array 11 and the diffuser 15. The condensing optical system 12 includes a collimating lens 13 and a condensing lens 14. The collimating lens 13 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 11. The condenser lens 14 is a convex lens. The collimating lens 13 causes the red light to be incident on the condenser lens 14 in a substantially collimated state. The condenser lens 14 causes the red light to be incident on the diffuser 15 in a substantially condensed state.

  The diffuser 15 is disposed on the optical path of the first light between the condensing optical system 12 and the collimating optical system 16.

  FIG. 3 is a schematic diagram showing the diffuser (first light diffusion portion) according to the first embodiment of the present invention. FIG. 3A is a side view of the diffuser, and FIG. 3B is a partially enlarged view of the diffuser (an enlarged view of a portion where light emitted from the condenser lens 14 is condensed). In FIG. 3, the basic configuration of the diffuser is shown, and the diffuser 15 configuring the first light source unit 10 is illustrated.

  As shown in FIG. 3A, the diffuser 15 is a rotating substrate that can rotate around a predetermined rotation axis CL1. The diffuser 15 diffuses the light emitted from the condenser lens 14 to generate diffused light, which is emitted from the emission end face 15s2. In the present embodiment, the light diffusion portion of the diffuser 15 is formed along the rotation direction of the rotating substrate. The diffuser 15 diffuses the light condensed on the incident end face 15s1 by refracting the light at the exit end face 15s2. The diffuser 15 is connected to a driving device and is movable. Specifically, the diffuser 15 has a shaft of a motor 15M fixed at the center, and can be rotated by the motor 15M.

  As shown in FIG. 3B, the diffuser 15 is configured by dispersing diffusing particles 15b having light diffusibility in a base material 15a made of a light transmitting material such as a transparent resin. The diffusing particles 15b are dispersed at positions separated from the rotation axis CL1 in the base material 15a (positions where the light emitted from the condenser lens 14 is condensed in the diffuser 15). The thickness of the diffuser 15 (base material 15a) is about 1 to 2 mm.

  As shown in FIG. 1, the collimating optical system 16 is disposed on the optical path of the first light between the diffuser 15 and the light combining optical system 80. The collimating optical system 16 includes a first lens 17 and a second lens 18. The first lens 17 and the second lens 18 are convex lenses. The collimating optical system 16 causes the light diffused by the diffuser 15 to enter the light combining optical system 80 (first wavelength selective reflection layer 41) in a substantially parallel state.

  The second light source unit 20 emits blue light as the second light. The second light source unit 20 includes a second light source array 21, a condensing optical system 22, a diffuser (first light diffusing unit) 25, and a collimating optical system 26.

  The second light source array 21 includes a base 21b and a plurality of second light sources 21a arranged on the base 21b (see FIG. 2A). A solid light source such as a laser light source and a light emitting diode (LED) is used as the second light source 21a. In the present embodiment, the second light source 21a is a laser light source that emits blue light (peak of emission intensity: about 445 nm) made of laser light as the second light. Note that a light source that emits blue light having a wavelength other than 445 nm may be used as the light source.

  The condensing optical system 22 is disposed on the optical path of the second light between the second light source array 21 and the diffuser 25. The condensing optical system 22 includes a collimating lens 23 and a condensing lens 24. The collimating lens 23 makes the blue light enter the condensing lens 24 in a substantially parallelized state. The condenser lens 24 causes the blue light to be incident on the diffuser 25 in a substantially condensed state.

  The diffuser 25 is disposed on the optical path of the second light between the condensing optical system 22 and the collimating optical system 26. The diffuser 25 diffuses the light emitted from the condenser lens 24 to generate diffused light, and emits the light from the emission end face 25s2 (see FIG. 3A). In the present embodiment, the light diffusion portion of the diffuser 25 is formed along the rotation direction of the rotating substrate. The diffuser 25 diffuses the light condensed on the incident end face 25s1 by refracting the light at the exit end face 25s2. The diffuser 25 has a shaft of a motor 25M fixed at the center, and can be rotated by the motor 25M.

  The diffuser 25 is configured by dispersing diffusing particles 25b having light diffusibility in a base material 25a made of a light transmitting material such as a transparent resin. The diffusing particles 25b are dispersed at positions separated from the rotation axis CL1 in the base material 25a (positions where the light emitted from the condensing lens 24 is condensed in the diffuser 25). The thickness of the diffuser 25 (base material 25a) is about 1 to 2 mm.

  The collimating optical system 26 is disposed on the optical path of the second light between the diffuser 25 and the light combining optical system 80. The collimating optical system 26 includes a first lens 27 and a second lens 28. The collimating optical system 26 causes the light diffused by the diffuser 25 to enter the light combining optical system 80 (first wavelength selective reflection layer 41) in a substantially parallel state.

  The third light source unit 30 converts blue light as third light into green light and emits it. The third light source unit 30 includes a third light source array 31, a condensing optical system 32, a rotating fluorescent plate 35, and a collimating optical system 36.

  The third light source array 31 includes a base 31b and a plurality of third light sources 31a arranged on the base 31b (see FIG. 2A). A solid light source such as a laser light source and a light emitting diode (LED) is used as the third light source 31a. In the present embodiment, the third light source 31a is a laser light source that emits blue light (peak of emission intensity: about 445 nm) made of laser light as the third light.

  The condensing optical system 32 is disposed on the optical path of the third light between the third light source array 31 and the rotating fluorescent plate 35. The condensing optical system 32 includes a collimating lens 33 and a condensing lens 34. The collimating lens 33 causes the blue light to enter the condensing lens 34 in a substantially collimated state. The condensing lens 34 makes the blue light incident on the rotating fluorescent plate 35 in a substantially condensed state.

  FIG. 4 is a schematic diagram showing the rotating fluorescent screen according to the first embodiment of the present invention. FIG. 4A is a side view of the rotating fluorescent plate, and FIG. 4B is a front view of the rotating fluorescent plate.

  As shown in FIG. 4, the rotating fluorescent plate 35 includes a disc 35b and a phosphor layer 35a. The disc 35b is formed of a light transmitting material such as quartz glass or transparent resin. A single phosphor layer 35a is continuously formed on a part of the disc 35b along the circumferential direction of the disc 35b.

  The phosphor layer 35a is formed on the disc 35b. The phosphor layer 35 a is excited by the blue light condensed by the condensing optical system 32, converts the blue light into green light, and radiates it toward the collimating optical system 36.

Specifically, the phosphor layer 35a converts blue light from the third light source 31a into green light and emits it. The phosphor layer 35a is efficiently excited by blue light having a wavelength of about 445 nm, converted into green light (fluorescence), and emitted. The phosphor layer 35a is made of, for example, a layer containing (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, which is a YAG phosphor. Note that a layer containing another phosphor that emits green light may be used as the phosphor.

  The shaft of the motor 35M is fixed to the center of the disc 35b, and can be rotated by the motor 35M. For this reason, the irradiation point with respect to the disk 35b (phosphor layer 35a) of the light condensed by the condensing optical system 32 is not fixed to one point. Therefore, the heat generated in the phosphor layer 35a by the incidence of light can be dissipated in a wide region along the circumferential direction.

  The collimating optical system 36 is disposed on the optical path of the third light between the rotating fluorescent plate 35 and the light combining optical system 80. The collimating optical system 36 includes a first lens 37 and a second lens 38. The collimating optical system 36 causes the fluorescence emitted from the rotating fluorescent plate 35 to enter the light combining optical system 80 (second wavelength selective reflection layer 50) in a substantially parallel state.

  The photosynthetic optical system 80 includes a first wavelength selective reflection unit 40 and a second wavelength selective reflection layer 50. The first wavelength selective reflection unit 40 includes a reflection mirror that reflects red light (first light) emitted by the first light source unit 10 (first light source). The first wavelength selective reflection unit 40 is the same direction as the reflection direction of the red light reflected by the blue light (second light) emitted by the second light source unit 20 (second light source) (see FIG. 1). -X direction).

  FIG. 5 is a schematic diagram showing a first wavelength selective reflection layer (reflection mirror) and a drive device constituting the first wavelength selective reflection unit according to the first embodiment of the present invention. FIG. 5A is a diagram when the driving device is stopped, and FIG. 5B is a diagram when the driving device is driving. In FIG. 5, reference numeral 41s1 is a reflecting surface on which the first light from the first light source unit 10 is reflected, reference numeral 41s2 is an incident surface on which the second light from the second light source unit 20 is incident, and reference numeral T is the first surface. This is the thickness of the one-wavelength selective reflection layer.

  As shown in FIG. 5, the first wavelength selective reflection unit 40 includes a first wavelength selective reflection layer 41 and a driving device 42. The first wavelength selective reflection layer 41 is a reflection mirror having a predetermined thickness T, and for example, a dichroic mirror can be used. The first wavelength selective reflection layer 41 reflects the first light emitted from the first light source unit 10 (first light source) on the reflection surface 41s1. The thickness T of the first wavelength selective reflection layer 41 is, for example, about 10 to 100 μm. A driving device 42 is attached to one end of the first wavelength selective reflection layer 41.

  The driving device 42 temporally varies the shape of the reflection surface 41s1 of the first wavelength selective reflection layer 41 so that the shape of the reflection surface 41s1 of the first wavelength selective reflection layer 41 undulates (see FIG. 5B). The driving device 42 includes a piezoelectric element 42 that applies vibration to the first wavelength selective reflection layer 41 in the thickness direction of the first wavelength selective reflection layer 41. The amplitude of vibration of the piezoelectric element 42 varies with time. When the piezoelectric element 42 is driven, the piezoelectric element 42 is driven with a predetermined frequency and an irregular amplitude in parallel with the normal direction of the reflection surface 41s1 of the first wavelength selective reflection layer 41. Then, the shape of the reflection surface 41 s 1 of the first wavelength selective reflection layer 41 changes irregularly in time within the drive time of the piezoelectric element 42.

  For example, when the vibration amplitude of the piezoelectric element 42 is varied with time, the control means (not shown) controls the piezoelectric element 42 at a predetermined timing so that the vibration amplitude of the piezoelectric element 42 becomes irregular with respect to time. The drive control signal is transmitted. Here, the phrase “the vibration amplitude of the piezoelectric element 42 is irregular in time” is not only the concept of making the entire driving time of the piezoelectric element 42 irregular, but also the driving time of the piezoelectric element 42. It also includes the concept of making it irregular at some times.

  As shown in FIG. 1, for example, a dichroic prism (color synthesis element) in which two triangular prism shapes are bonded to each other can be used for the second wavelength selective reflection layer 50. The surface to be bonded in the triangular prism becomes the inner surface of the dichroic prism. A mirror surface that reflects the first light and the second light and transmits the third light is formed on the inner surface of the dichroic prism. The first light and the second light incident on the dichroic prism are selectively reflected by the mirror surface. The third light that has entered the dichroic prism is emitted through the mirror surface in the same direction as the reflection direction of the first light and the second light. That is, the second wavelength selective reflection layer 50 reflects the first light and the second light synthesized by the first wavelength selective reflection layer 41 and transmits the third light emitted from the third light source unit 30. Then, the first light, the second light, and the third light are combined. In this way, the light combined by the light combining optical system 80 is emitted toward the illumination optical system 100.

  As shown in FIG. 1, the illumination optical system 100 is disposed between the light combining optical system 80 (second wavelength selective reflection layer 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 divides the light (first light, second light, and third light) from the light combining optical system 80 by a plurality of element lenses constituting the first fly-eye lens 111 and individually Has a function of condensing light. 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 makes the light intensity distribution of the light combined by the light combining optical system 80 uniform.

  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, reflection mirrors 230, 240 and 250, and relay lenses 260 and 270. The color separation light guide optical system 200 separates light (first light, second light, and third light) from the illumination device 1 (illumination optical system 100) into red light, green light, and blue light, It has a function of guiding each color light of red light, green light and blue light 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 condenser lenses 300R, 300G, and 300B and the relay lenses 260 and 270 are part of the integrator optical system that constitutes the projector 1000.

  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 reflects a green light component and a blue light component. The dichroic mirror 220 reflects the green light component and transmits the blue light component.

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

  The red light transmitted through the dichroic mirror 210 is reflected by the reflection mirror 230, passes through the condenser lens 300R, and enters the image forming region of the liquid crystal light modulation device 400R for red light. The green light reflected by the dichroic mirror 210 is further 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 blue light transmitted through the dichroic mirror 220 passes through the relay lens 260, the incident-side reflecting mirror 240, the relay lens 270, the exit-side reflecting mirror 250, and the condensing lens 300B, thereby forming an image of the liquid crystal light modulation device 400B for blue light. Incident into the area.

  The relay lenses 260 and 270 and the reflection mirrors 240 and 250 have a function of guiding the blue light component transmitted through the dichroic mirror 220 to the liquid crystal light modulation device 400B. Thereby, even when the length of the optical path of blue light is longer than the length of the optical path of the other color light, it is possible to suppress a decrease in utilization efficiency of the blue light due to the divergence of the blue light. In addition, when the length of the optical path of other color light (for example, red light) is longer than the length of the optical path of blue light, the structure which arrange | positions the relay lenses 260 and 270 and the reflective mirrors 240 and 250 in the optical path of red light is also considered. It is done.

  The liquid crystal light modulation devices 400R, 400G, and 400B form color images by modulating incident color light according to image information, and are illumination targets of the illumination 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 illuminating device 1 of the present embodiment, since the corrugated shape is formed on the reflection surface 41s1 of the first wavelength selective reflection layer 41, the first light (laser light) incident on the reflection surface 41s1 is reflected. It is diffused by the uneven shape of the surface 41s1. Since the diffused first light is less likely to cause interference, the generation of speckle is suppressed. In addition, since the shape of the reflection surface 41s1 that reflects the first light (laser light) varies with time, the speckle pattern displayed on the screen varies with time. Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized. Thus, according to the illuminating device 1 of this embodiment, speckle noise is suppressed by temporally changing the speckle pattern while suppressing generation of speckle. Therefore, the effect of suppressing speckle noise is higher than the configuration of Patent Document 1 in which speckle noise is suppressed by simply changing the position where speckle is displayed.

  Further, according to this configuration, the first light diffusing unit 15 and the collimating optical system 16 are arranged on the optical path of the first light between the first light source array 11 and the first wavelength selective reflection layer 41. Therefore, the first light is diffused twice by the first light diffusion portion 15 and the first wavelength selective reflection layer 41. Therefore, speckle noise can be more reliably suppressed.

  Further, according to this configuration, since the first light diffusing unit 15 is formed along the rotation direction of the rotating substrate, the position at which the first light is incident on the first light diffusing unit 15 changes with time. . Therefore, the speckle pattern formed by the first light emitted from the first light diffusing unit 15 also changes with time. Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized. Therefore, speckle noise is more effectively suppressed.

  Further, according to this configuration, the shape of the reflection surface 41 s 1 of the first wavelength selective reflection layer 41 can be accurately controlled by the piezoelectric element 42.

  Further, according to this configuration, since the reflection mirror is the first wavelength selective reflection layer 41 (for example, a dichroic mirror), the reflection mirror can be used as a means for combining the first light and the second light. For this reason, the configuration is simplified as compared with the case where the combining means is provided separately from the reflecting mirror.

  Further, according to this configuration, the third light source array 31 that emits the third light is provided, and the second wavelength selection in which the light combining optical system 80 combines the first light, the second light, and the third light. A reflective layer 50 is provided. Therefore, a light combining optical system capable of combining three types of light while suppressing speckle noise generated by the first light can be realized with a simple configuration.

  Further, according to this configuration, since the third light source unit 30 emits the fluorescence as the third light, it is possible to extract the light without speckle noise. For example, by using a blue laser light source as the excitation light source and arranging a phosphor layer that absorbs blue light and converts it into green fluorescence as the phosphor layer, it is possible to obtain green light without speckle noise.

Moreover, according to this structure, since the 1st light is red light, the effect which suppresses speckle noise becomes remarkable. It is known that the human eye has different intensities (specific luminous sensitivity) for sensing light for each wavelength, and in particular, the specific luminous sensitivity of red light is higher than that of blue. Therefore, the effect of suppressing speckle noise is enhanced when the first light is red light.
According to this configuration, in addition to the first light being red light, the second light is blue light and the third light is green light. By such color selection, the green light with the highest relative visibility is not a laser beam, so speckles do not occur, and the red light with the next highest relative visibility is a reflection system, so the speckle reduction effect is significant. Become.

  According to the projector 1000 of the present embodiment, since the illumination device 1 described above is provided, it is possible to provide the projector 1000 that can reliably suppress speckle noise.

  In the lighting device 1 of the present embodiment, the first light is red light, the second light is blue 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, the second light, and the third light have the same color.

  Moreover, in the illuminating device 1 of this embodiment, although the convex lens was used as the 1st lens and the 2nd lens in a collimating optical system, it is not restricted to this. In short, it is sufficient that the collimating optical system is made to enter the light combining optical system in a state where the light diffused by the first light diffusing unit 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 illuminating device 1 of this embodiment, in this embodiment, although the light-diffusion part of a diffuser is formed along the rotation direction of a rotating substrate, it is not restricted to this. For example, the light diffusion portion of the diffuser may be formed on the entire rotating substrate.

  In the illumination device 1 of the present embodiment, the dichroic prism (color combining element) in which two triangular prism shapes are bonded to each other is used as the second wavelength selective reflection layer 50. However, the present invention is not limited to this. For example, a dichroic mirror may be used as the second wavelength selective reflection layer 50.

  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. 6 is a schematic diagram showing the illumination device 2 according to the second embodiment of the present invention.
As shown in FIG. 6, the illuminating device 2 according to the present embodiment is different from the illuminating device 1 according to the first embodiment described above in that a light combining optical system 80A is provided instead of the above-described light combining optical system 80. ing. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The illumination device 2 includes a first light source unit 10, a second light source unit 20, a third light source unit 30, a light combining optical system 80A, and an illumination optical system 100.

  The photosynthesis optical system 80 </ b> A includes a third wavelength selective reflection layer 60 and a fourth wavelength selective reflection unit 70.

  The third wavelength selective reflection layer 60 reflects the red light (first light) emitted from the first light source unit 10 (first light source) and reflects the blue light emitted from the second light source unit 20 (second light source). The light (second light) is transmitted, and the first light and the second light are combined.

  The fourth wavelength selective reflection unit 70 includes a reflection mirror that reflects the first light and the second light synthesized by the third wavelength selective reflection layer 60. The fourth wavelength selective reflection unit 70 reflects the first light and the second light reflected by the green light (third light) emitted by the third light source unit 30 (third light source). The light is transmitted in the same direction (+ Y direction shown in FIG. 6).

  FIG. 7 is a schematic diagram showing a fourth wavelength selective reflection layer (reflection mirror) and a drive device that constitute a fourth wavelength selective reflection unit according to the third embodiment of the present invention. FIG. 7A is a side view of the fourth wavelength selective reflection unit, and FIG. 7B is a front view of the fourth wavelength selective reflection unit. In FIG. 7, reference numeral 71s1 is a reflecting surface on which the first light and second light from the third wavelength selective reflection layer 60 are reflected, and reference numeral 71s2 is incident on the third light from the third light source unit 30. The incident surface.

  As shown in FIG. 7, the fourth wavelength selective reflection unit 70 includes a fourth wavelength selective reflection layer 71 and a plurality of driving devices 72 a to 72 d. The fourth wavelength selective reflection layer 71 is a reflection mirror having a predetermined thickness, and for example, a dichroic mirror can be used. The fourth wavelength selective reflection layer 71 reflects the first light and the second light from the third wavelength selective reflection layer 60 by the reflection surface 71s1, and transmits the third light from the third light source unit 30. The first light, the second light, and the third light are combined. The thickness of the fourth wavelength selective reflection layer 71 is, for example, about 10 to 100 μm. A plurality of drive devices 72 a to 72 d are attached around the fourth wavelength selective reflection layer 71.

  The plurality of driving devices 72 a to 72 d are arranged at different positions around the fourth wavelength selective reflection layer 71. Specifically, each of the driving devices 72 a to 72 d is provided at a position corresponding to the central portion of each side of the fourth wavelength selective reflection layer 71 having a rectangular shape when viewed from the front. The drive device 72a is disposed to face the drive device 72b, and the drive device 72c is disposed to face the drive device 72d. The amplitudes of the respective driving devices 72a to 72d are different from each other in magnitude that varies with time.

  Each of the driving devices 72a to 72d temporally varies the shape of the reflection surface 71s1 of the fourth wavelength selective reflection layer 71 so that the shape of the reflection surface 71s1 of the fourth wavelength selective reflection layer 71 is undulated. Each of the driving devices 72 a to 72 d includes piezoelectric elements (piezo elements) 72 a to 72 d that apply vibration to the fourth wavelength selective reflection layer 71 in the thickness direction of the fourth wavelength selective reflection layer 71. The amplitude of vibration of each of the piezoelectric elements 72a to 72d varies with time. When driving each of the piezoelectric elements 72a to 72d, the piezoelectric elements 72a to 72d are driven at a predetermined frequency in parallel with the normal direction of the reflection surface 71s1 of the fourth wavelength selective reflection layer 71 and with irregular amplitudes different from each other. Then, the shape of the reflection surface 71s1 of the fourth wavelength selective reflection layer 71 changes irregularly in time within the drive time of each of the piezoelectric elements 72a to 72d.

  For example, when the magnitude of the vibration amplitude of each of the piezoelectric elements 72a to 72d varies from time to time, the amplitude of the vibration of each of the piezoelectric elements 72a to 72d is not illustrated so as to be irregular in time. A drive control signal is transmitted to each of the piezoelectric elements 72a to 72d at a predetermined timing by the control means. Here, not only the concept of making the amplitude of vibration of each of the piezoelectric elements 72a to 72d irregular in time is not only the concept of making the entire driving time of each of the piezoelectric elements 72a to 72d irregular. This also includes the concept of making the piezoelectric elements 72a to 72d irregular in some of the drive times.

  According to the illuminating device 2 of the present embodiment, the reflection surface of the fourth wavelength selective reflection layer 71 can be obtained by variously combining the installation positions of the piezoelectric elements 72a to 72d and the vibration amplitudes and phases of the piezoelectric elements 72a to 72d. The shape of 71s1 can be controlled more freely.

  According to this configuration, both the first light and the second light are reflected by the fourth wavelength selective reflection layer 71. Therefore, even when the second light is a laser beam, the speckle generated by the second light does not greatly deteriorate the display quality.

  Further, according to this configuration, a light combining optical system capable of combining three types of light while suppressing speckle noise generated by the first light and the second light can be realized with a simple configuration.

  In the illumination device 2 of the present embodiment, the configuration in which the four piezoelectric elements 72a to 72d are arranged at different positions around the fourth wavelength selective reflection layer 71 has been described as an example, but the present invention is not limited thereto. . For example, the number of piezoelectric elements arranged around the fourth wavelength selective reflection layer 71 may be two or three, or even five or more. Further, the arrangement position of the piezoelectric elements arranged around the fourth wavelength selective reflection layer 71 can be changed as appropriate.

(Third embodiment)
FIG. 8 is a schematic diagram showing the illumination device 3 according to the third embodiment of the present invention.
As shown in FIG. 8, the illuminating device 3 according to the present embodiment includes a third light source unit 30A in place of the above-described third light source unit 30, and a light combining optical system in place of the above-described light combining optical system 80A. It differs from the illuminating device 2 which concerns on the above-mentioned 2nd Embodiment by the point provided with 80B. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The illumination device 3 includes a first light source unit 10, a second light source unit 20, a third light source unit 30A, a light combining optical system 80B, and an illumination optical system 100.

  The third light source unit 30A converts blue light as third light into green light and emits it. The third light source unit 30A includes a third light source array 31, a collimating optical system 32A, a rotating fluorescent plate 35A, and a collimating optical system 36.

  The collimating optical system 32A is disposed on the optical path of the third light between the third light source array 31 and the light combining optical system 80B (fourth wavelength selective reflection unit 70A). The collimating optical system 32A includes a first lens 33A and a second lens 34A. The collimating optical system 32A causes blue light to enter the fourth wavelength selective reflection unit 70A in a substantially parallel state.

  The collimating optical system 36 is disposed on the optical path of the third light between the light combining optical system 80B (fourth wavelength selective reflection unit 70A) and the rotating fluorescent plate 35A. The collimating optical system 36 includes a first lens 37 and a second lens 38. The collimating optical system 36 causes the blue light from the fourth wavelength selective reflection unit 70A to be substantially condensed and incident on the rotating fluorescent plate 35A (phosphor layer) and is emitted from the rotating fluorescent plate 35A (phosphor layer). Are made incident on the fourth wavelength selective reflection unit 70A in a substantially parallel state.

The rotating fluorescent plate 35A includes a circular plate and a phosphor layer. The disc is made of a metal such as aluminum (thermal conductivity: 236 W · m ⁻¹ · K ⁻¹ ) or copper (thermal conductivity: 398 W · m ⁻¹ · K ⁻¹ ), for example. The disc radiates heat accumulated in the phosphor layer when blue light from the third light source array 31 enters the phosphor layer. In order to improve the heat dissipation performance of the disk, the disk may be formed in a shape that increases the surface area, such as providing a plurality of protrusions on the back surface of the disk. The disk has a polished surface and a metallic luster, and has a large reflection coefficient for incident light. Further, the light-reflective material (SiO ₂ , NbO, TiO _2, etc.) may be added as a thin film to the surface of the disk to constitute the enhanced reflection film.

  The photosynthetic optical system 80B includes a third wavelength selective reflection layer 60 and a fourth wavelength selective reflection unit 70A. The third wavelength selective reflection layer 60 reflects the red light (first light) emitted from the first light source unit 10 (first light source) and reflects the blue light emitted from the second light source unit 20 (second light source). The light (second light) is transmitted, and the first light and the second light are combined. The fourth wavelength selective reflection unit 70 </ b> A includes a reflection mirror that reflects the first light and the second light synthesized by the third wavelength selective reflection layer 60. The fourth wavelength selective reflection unit 70A reflects the blue light emitted by the third light source array 31 toward the rotating fluorescent plate 35A, and the green light (third light source) emitted by the third light source unit 30A (third light source). Light) is transmitted in the same direction as the reflection direction of the first light and the second light reflected by itself (+ Y direction shown in FIG. 8).

  The fourth wavelength selective reflection unit 70A includes a fourth wavelength selective reflection layer and a plurality of driving devices. The fourth wavelength selective reflection layer is a reflection mirror having a predetermined thickness, and for example, a dichroic mirror can be used. The fourth wavelength selective reflection layer reflects the first light and the second light from the third wavelength selective reflection layer 60 on the reflection surface, transmits the third light from the third light source unit 30A, and transmits the third light. The first light, the second light, and the third light are combined.

  According to the illumination device 3 of the present embodiment, the laser light emitted by the third light source array 31 is reflected by the fourth wavelength selective reflection layer before entering the rotating fluorescent plate 35A, so speckle noise is more reliably prevented. Can be suppressed.

(Fourth embodiment)
FIG. 9 is a schematic diagram showing an illumination device 4 according to the fourth embodiment of the present invention.
As shown in FIG. 9, the illuminating device 4 according to this embodiment includes the first light between the light combining optical system 80 (second wavelength selective reflection layer 50) and the illumination optical system 100 (integrator optical system 110). It differs from the illuminating device 1 which concerns on the above-mentioned 1st Embodiment by the point by which the diffuser (2nd light-diffusion part) 90 is arrange | positioned on an optical path. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The illumination device 4 includes a first light source unit 10, a second light source unit 20, a third light source unit 30, a light combining optical system 80, a diffuser 90, and an illumination optical system 100. .

  The diffuser 90 is disposed on the optical path of the first light between the second wavelength selective reflection layer 50 and the integrator optical system 110. The diffuser 90 is a rotating substrate that can rotate around a predetermined rotation axis. The diffuser 90 has a motor shaft fixed at the center, and can be rotated by the motor. The diffuser 90 diffuses the light emitted from the second wavelength selective reflection layer 50 to generate diffused light, and emits the light from the emission end face. The diffused light emitted from the diffuser 90 enters the integrator optical system 110.

  According to the illumination device 4 of the present embodiment, the first light is doubly diffused by the diffuser 90 and the first wavelength selective reflection layer 41, so that speckle noise can be more reliably suppressed.

  In the illumination device 4 of the present embodiment, the configuration in which the diffuser 90 is disposed on the optical path of the first light between the second wavelength selective reflection layer 50 and the integrator optical system 110 has been described as an example. However, it is not limited to this. For example, the diffuser 90 may be disposed on the optical path of the first light between the first wavelength selective reflection layer 41 and the second wavelength selective reflection layer 50.

(Fifth embodiment)
FIG. 10 is a schematic diagram showing an illumination device 5 according to the fifth embodiment of the present invention.
As shown in FIG. 10, the illuminating device 5 according to the present embodiment is an illuminating device according to the above-described fourth embodiment in that a diffuser 90 </ b> A is arranged instead of the above-described diffuser (second light diffusing unit) 90. 4 and different. That is, in the illuminating device 5 of this embodiment, the diffuser 90A has a vibration configuration. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The illumination device 5 includes a first light source unit 10, a second light source unit 20, a third light source unit 30, a light combining optical system 80, a diffuser 90A, and an illumination optical system 100. .

  The diffuser 90 </ b> A is disposed on the optical path of the first light between the second wavelength selective reflection layer 50 and the integrator optical system 110. A vibration device is attached to one end of the diffuser 90A. The diffuser 90A can be vibrated by a vibration device. The diffuser 90A diffuses the light emitted from the second wavelength selective reflection layer 50 to generate diffused light and emits the light from the emission end face. The diffused light emitted from the diffuser 90 </ b> A enters the integrator optical system 110.

  According to the illumination device 5 of the present embodiment, the first light is doubly diffused by the diffuser 90A and the first wavelength selective reflection layer 41, so speckle noise can be more reliably suppressed.

(Sixth embodiment)
FIG. 11 is a schematic diagram showing an illumination device 6 according to the sixth embodiment of the present invention.
As shown in FIG. 11, the illuminating device 6 according to this embodiment includes a third light source unit 30 </ b> B instead of the above-described third light source unit 30, and a light combining optical system instead of the above-described light combining optical system 80. It differs from the illuminating device 1 which concerns on the above-mentioned 1st Embodiment by the point provided with 80C. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The illumination device 6 includes a first light source unit 10, a second light source unit 20, a third light source unit 30B, a light combining optical system 80C, and an illumination optical system 100.

  The third light source unit 30B emits green light as the third light. The third light source unit 30B includes a third light source array 31B, a condensing optical system 32, a diffuser (first light diffusing unit) 35B, and a collimating optical system 36.

  The third light source array 31B includes a base and a plurality of third light sources arranged on the base. A solid light source such as a laser light source and a light emitting diode (LED) is used as the third light source. In the present embodiment, the third light source is a laser light source that emits green light (emission intensity peak: about 555 nm) made of laser light as the third light. A light source that emits green light having a wavelength other than 555 nm can also be used as the light source.

  The condensing optical system 32 is disposed on the optical path of the third light between the third light source array 31B and the diffuser 35B. The condensing optical system 32 includes a collimating lens 33 and a condensing lens 34. The collimating lens 33 causes the green light to enter the condensing lens 34 in a substantially collimated state. The condensing lens 34 makes the green light incident on the diffuser 35B in a substantially condensed state.

  The diffuser 35B is disposed on the optical path of the third light between the condensing optical system 32 and the light combining optical system 80C. The diffuser 35B diffuses the light emitted from the condenser lens 34 to generate diffused light, and emits the light from the exit end face. In the present embodiment, the light diffusion portion of the diffuser 35B is formed along the rotation direction of the rotating substrate. The diffuser 35B diffuses the light by refracting the light collected on the incident end face at the exit end face. The diffuser 35B has a motor shaft fixed at the center, and can be rotated by the motor.

  The diffuser 35B is configured by dispersing diffusing particles having light diffusibility in a base material made of a light transmitting material such as a transparent resin. The diffusing particles are dispersed at positions separated from the rotation axis in the substrate (positions where the light emitted from the condensing lens 34 is condensed in the diffuser 35B). The thickness of the diffuser 35B (base material) is about 1 to 2 mm.

  The collimating optical system 36 is disposed on the optical path of the third light between the diffuser 35B and the light combining optical system 80C (fifth wavelength selective reflection unit 40B). The collimating optical system 36 includes a first lens 37 and a second lens 38. The collimating optical system 36 causes the light diffused by the diffuser 35B to enter the light combining optical system 80 (fifth wavelength selective reflection unit 40B) in a substantially parallel state.

  The fifth wavelength selective reflection unit 40B includes a fifth wavelength selective reflection layer and a driving device. The fifth wavelength selective reflection layer is a reflection mirror having a predetermined thickness, and for example, a dichroic mirror can be used. The fifth wavelength selective reflection layer reflects green light (third light) emitted from the third light source unit 30B (third light source) on the reflection surface. The thickness of the fifth wavelength selective reflection layer is, for example, about 10 to 100 μm. A driving device is attached to one end of the fifth wavelength selective reflection layer.

  The driving device temporally varies the shape of the reflection surface of the fifth wavelength selective reflection layer so that the shape of the reflection surface of the fifth wavelength selective reflection layer is undulated. The driving device includes a piezoelectric element (piezo element) that applies vibration to the fifth wavelength selective reflection layer in the thickness direction of the fifth wavelength selective reflection layer. The amplitude of vibration of the piezoelectric element varies with time. When the piezoelectric element is driven, it is driven at a predetermined frequency and with an irregular amplitude in parallel with the normal direction of the reflection surface of the fifth wavelength selective reflection layer. Then, the shape of the reflection surface of the fifth wavelength selective reflection layer changes irregularly in time within the drive time of the piezoelectric element.

  According to the illuminating device 6 of the present embodiment, a concavo-convex shape that undulates is formed on the reflection surface of the fifth wavelength selective reflection layer. Diffused by shape. Since the diffused third light is less likely to cause interference, speckle generation is suppressed. In addition, since the shape of the reflecting surface that reflects the third light (laser light) varies with time, the speckle pattern displayed on the screen varies with time. Such speckle patterns are temporally superimposed and averaged, so that speckles are hardly recognized. Thus, according to the illuminating device 6 of this embodiment, speckle noise is suppressed by temporally changing the speckle pattern while suppressing generation of speckle. Therefore, the illuminating device 6 which can suppress speckle noise reliably can be provided.

  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 illumination 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 lighting device of the present invention can be applied to other optical devices (for example, an optical disk device, a car headlamp, a lighting device, etc.).

1, 2, 3, 4, 5, 6 ... Illumination device, 11a ... first light source, 15, 25, 35B ... diffuser (first light diffusion part), 21a ... second light source, 16, 26, 36 ... collimating optics System 31a 3rd light source 35a Phosphor layer 41 41 Dichroic mirror (first wavelength selective reflection layer) 41s1 Reflecting surface 42, 72a 72b 72c 72d Drive unit 50 Dichroic prism ( (Second wavelength selective reflection layer), 60... Dichroic mirror (third wavelength selective reflection layer), 80, 80A, 80B, 80C... Light synthesis optical system, 90, 90A. 400B ... Liquid crystal light modulation device (light modulation device), 600 ... Projection optical system, 1000 ... Projector

Claims (12)

A first light source that emits first light;
A second light source that emits second light;
A reflection mirror that reflects at least the first light emitted from the first light source, and combines the second light emitted from the second light source with the first light reflected by the reflection mirror; A photosynthetic optical system,
A driving device that temporally varies the shape of the reflecting surface of the reflecting mirror so that the shape of the reflecting surface of the reflecting mirror undulates;
With
At least the first light source Ri laser source der which emits laser light as the first light,
The drive device includes a piezoelectric element that imparts vibration to the reflection mirror in a thickness direction of the reflection mirror,
An illuminating device characterized in that the amplitude of vibration of the piezoelectric element varies with time . On the optical path of the first light between the first light source and the reflection mirror,
A first light diffusing unit that diffuses the first light emitted by the first light source;
The collimating optical system which collimates the 1st light diffused by the said 1st light-diffusion part and injects into the said reflective mirror is arrange | positioned, The illuminating device of Claim 1 characterized by the above-mentioned.   The lighting device according to claim 2, wherein the first light diffusion portion is formed along a rotation direction of the rotating substrate.   4. The illumination device according to claim 2, wherein a second light diffusion unit that diffuses the first light is disposed on an optical path of the first light reflected by the reflection mirror. 5. . A plurality of the piezoelectric elements are arranged at different positions around the reflection mirror,
The lighting device according to any one of claims 1 to 4 , wherein amplitudes of vibrations of the piezoelectric elements are different from each other in magnitude that varies with time. The reflection mirror is a first wavelength selective reflection layer that transmits the second light emitted from the second light source in the same direction as the reflection direction of the first light reflected by itself. The illumination device according to any one of claims 1 to 5 . A third light source for emitting third light;
The light combining optical system reflects the first light and the second light combined by the first wavelength selective reflection layer, transmits the third light emitted by the third light source, The lighting device according to claim 6 , further comprising a second wavelength selective reflection layer that synthesizes the first light, the second light, and the third light. The light combining optical system reflects the first light emitted from the first light source, transmits the second light emitted from the second light source, and transmits the first light and the second light. A third wavelength selective reflection layer for combining the light of
The reflection mirror that reflects the first light and the second light synthesized by the third wavelength selective reflection layer;
The lighting device according to any one of claims 1 to 5, characterized in that it comprises. A third light source for emitting third light;
The reflection mirror reflects the first light and the second light synthesized by the three-wavelength selective reflection layer, transmits the third light emitted by the third light source, and transmits the third light. The lighting device according to claim 8 , wherein the first light, the second light, and the third light are combined. The third light source includes an excitation light source that emits excitation light, and a phosphor layer that emits fluorescence when excited by the excitation light emitted by the excitation light source,
The lighting device according to claim 7 or 9, characterized in that for emitting the fluorescence as the third light. The lighting device according to any one of claims 1 to 10, wherein the first light is red light. The lighting device according to any one of claims 1 to 11 ,
A light modulation device that modulates light emitted from the illumination 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:

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