JP2016173390A - Lighting device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device capable of preventing degradation in light utilization efficiency, and a projector including the lighting device.SOLUTION: The lighting device includes: a light-emitting element that emits a beam of first light; a reflection element; a drive element that drives the reflection element so that the travelling direction of the first light which is reflected by the reflection element changes as time passes; a light scattering element that outputs a beam of second light receiving the first light reflected by the reflection element; and a lens having a positive power, which is disposed on the optical path between the reflection element and a light scattering element, and on which the first light and the second light incident. The lighting device is configured so as to allow the second light passing through the lens to be incident on the reflection element.SELECTED DRAWING: Figure 1

Description

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

  2. Description of the Related Art Conventionally, a light source device that irradiates a phosphor layer with excitation light emitted from a light source such as a laser and uses illumination light as light emitted from the phosphor layer is known. In this light source device, the phosphor layer is cooled by rotating the phosphor wheel provided with the phosphor layer. However, since the light density of the excitation light is high, the calorific value per unit area of the phosphor layer is increased, and a sufficient cooling effect is not obtained. Therefore, the irradiation position of the excitation light is moved in the radial direction of the phosphor wheel using a vibrating mirror (see, for example, Patent Document 1 below).

By the way, in the following Patent Document 2, a lens integrator is used in order to equalize the illuminance distribution on the liquid crystal panel (light modulation device).
Therefore, a configuration in which a lens integrator is combined with the illumination device of Patent Document 1 can be considered. In this case, the lens integrator is provided on the optical path of the G light reflected by the dichroic mirror.

JP 2013-54332 A JP 2013-250494 A

  However, in the configuration according to the above combination, since the light emitting region in the phosphor layer is moved in the radial direction, the secondary light source image on the multilens of the lens integrator is moved in time, and the light use efficiency is increased. This causes a problem of lowering.

  One embodiment of the present invention has been made to solve the above-described problems, and an object thereof is to provide an illumination device that can suppress a decrease in light utilization efficiency. Another object of one embodiment of the present invention is to provide a projector including the above lighting device.

  According to the first aspect of the present invention, the reflection element is configured such that the light emitting element that emits the first light, the reflection element, and the traveling direction of the first light reflected by the reflection element change with time. A driving element for driving the element, a light scattering element for receiving the first light reflected by the reflecting element and emitting a second light, and an optical path between the reflecting element and the light scattering element. And a lens having a positive power through which the first light and the second light are incident, and the second light transmitted through the lens is configured to be incident on the reflective element. A lighting device is provided.

  According to this embodiment, since the second light emitted from the light scattering element enters the reflective element via the lens, for example, the optical member disposed on the optical path of the second light reflected by the reflective element In the above, the movement amount of the secondary light source image formed by the second light can be suppressed. Therefore, since the second light is efficiently taken into the optical member, it is possible to suppress a decrease in light utilization efficiency.

  In the first aspect, it is preferable that the reflecting element is provided at a focal position of the lens.

In the first aspect, a dichroic mirror that is provided between the light emitting element and the reflective element and separates the first light and the second light, and the second light separated by the dichroic mirror. And an integrator optical system provided on the optical path.
According to this configuration, the second light can be efficiently incident on the optical member provided on the optical path of the second light reflected by the dichroic mirror.

In the first aspect, it is preferable that the light scattering element is provided on a rotatable substrate, and the driving element drives the reflecting element in synchronization with the rotation of the substrate.
According to this configuration, since the incident position of the first light in the light scattering element changes in synchronization with the rotation of the substrate, an increase in temperature of the light scattering element can be suppressed.

In the first aspect, the drive element rotates the reflective element with reference to a first rotation axis, and the first rotation axis forms an angle of approximately 90 ° with the second rotation axis of the substrate. It is preferable to make it.
According to this configuration, since the optical path of the first light changes in the radial direction of the substrate within a plane including the normal line of the substrate, the incident position of the first light with respect to the light scattering element changes in the radial direction of the substrate. To do.

In the first aspect, it is preferable that the light emitting element changes the output of the first light in synchronization with the rotation of the substrate.
According to this configuration, when the first light is periodically irradiated to the specific portion of the light scattering element, the output of the first light is synchronized with the timing at which the first light is irradiated to the specific portion. Can be reduced. Therefore, it is possible to suppress the occurrence of a problem such that the temperature of a specific portion of the light scattering element is greatly increased as compared with other portions.

In the first aspect, it is preferable that the light scattering element is fixedly disposed and has a size that is at least twice the size of the spot of the first light incident on the light scattering element.
According to this structure, since the ratio of the incident area of the 1st light which occupies for the whole light-scattering element is small, the temperature rise in a light-scattering element can be suppressed.

  According to the second aspect of the present invention, the illumination device according to the first aspect, a light modulation device that forms image light by modulating light emitted from the illumination device according to image information, and the image A projection optical system that projects light is provided.

  Since the projector according to the second aspect includes the illumination device according to the first aspect, it can project a bright image using light efficiently.

FIG. 3 is a diagram showing an optical system of a projector 1000 according to the first embodiment. (A), (b) is a figure shown in order to demonstrate a rotation fluorescent screen. (A)-(c) is the figure which changed the advancing direction of blue light temporally. The figure which shows the relationship between the irradiation position of the blue light on a fluorescent substance layer, and the rotation angle of a board | substrate. The figure for demonstrating the synchronization method which concerns on a modification. FIG. 10 is a diagram showing an optical system of a projector 1000 according to a second embodiment. FIG. 10 is a diagram showing an optical system of a projector 1000 according to a third embodiment. (A), (b) is a figure which shows the structure which concerns on a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

(First embodiment)
FIG. 1 is a diagram showing an optical system of a projector 1000 according to the present embodiment.
FIG. 2 is a view for explaining the rotating fluorescent plate 30 in the present embodiment. FIG. 2A is a front view of the rotating fluorescent plate 30, and FIG. 2B is a cross-sectional view taken along arrow A1-A1 in FIG.

  As shown in FIG. 1, the projector 1000 according to the present embodiment includes a first illumination device 101, a second illumination device 702, a color separation light guide optical system 202, liquid crystal light modulation devices 400R, 400G, and 400B, and a cross dichroic prism 500. And a projection optical system 600.

  The first lighting device 101 emits light including red light and green light as illumination light. The first illumination device 101 includes a light source device 10, a collimating optical system 70, a dichroic mirror 80, a pickup lens 90, a reflection mirror (reflection element) 110, a drive element 111, a rotating fluorescent plate 34, a first lens array 120, and a second lens array. 130, a polarization conversion element 140, and a superimposing lens 150.

  The light source device 10 is disposed so that the optical axis is orthogonal to the illumination optical axis 101ax. The light source device 10 includes a laser light source that emits blue light (first light) including laser light as excitation light. The peak of the blue light emission intensity is about 445 nm. The light source device 10 may be composed of one laser light source, or may be composed of many laser light sources. A light source device that emits blue light having a wavelength other than 445 nm (for example, 460 nm) can also be used.

  The collimating optical system 70 includes a first lens 72 and a second lens 74. The collimating optical system 70 makes the blue light from the light source device 10 substantially parallel. Each of the first lens 72 and the second lens 74 is a convex lens.

  The dichroic mirror 80 is disposed in the optical path from the collimating optical system 70 to the reflection mirror 110 so as to intersect with each of the optical axis of the light source device 10 and the illumination optical axis 101ax at an angle of 45 °. The dichroic mirror 80 transmits blue light and reflects red light and green light.

  The reflection mirror (reflection element) 110 reflects the blue light B from the dichroic mirror 80 toward the pickup lens 90.

The pickup lens 90 is a lens having a positive power, and has a function of causing the blue light B from the reflecting mirror 110 to be incident on the phosphor layer 46 of the rotating phosphor plate 34 in a substantially condensed state, and exit from the phosphor layer 46. A function of making the fluorescent light Y (second light) substantially parallel. The pickup lens 90 corresponds to a “lens” in the claims.
The blue light B that has passed through the pickup lens 90 is incident on different positions on the phosphor layer 46 according to the rotation angle of the reflection mirror 110.

  The reflection mirror 110 is provided at the focal position of the pickup lens 90. Therefore, the reflection mirror 110 can efficiently cause the fluorescence Y emitted from the phosphor layer 46 to enter the first lens array 120 as will be described later.

  As shown in FIG. 2, the rotating fluorescent plate 34 has a phosphor layer 46 provided on a substrate 40 that can be rotated by a motor 50 along the circumferential direction of the substrate 40. The substrate 40 rotates around the rotation axis (second rotation axis) O2.

  The phosphor layer 46 converts the blue light B from the reflection mirror 110 into a fluorescence Y containing red light R and green light G and emits it. That is, the phosphor layer 46 constitutes a light scattering element in the claims.

The phosphor layer 46 is made of, for example, a layer containing (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce which is a YAG phosphor.

  Blue light B enters the rotating fluorescent plate 34 from the phosphor layer 46 side. A reflective film 45 that reflects visible light is provided between the phosphor layer 46 and the substrate 40. Therefore, the fluorescence Y is emitted toward the side on which the blue light B is incident. It is not always necessary to use the substrate 40 made of a material that transmits the blue light B, and the substrate 40 made of an opaque material such as metal may be used.

  When the blue light B is incident on the phosphor layer 46 in a condensed state, the phosphor layer 46 generates heat locally. When the temperature of the phosphor layer 46 increases, a phenomenon called temperature quenching occurs in which the conversion efficiency from the blue light B to the fluorescence Y decreases.

  In contrast, the first lighting device 101 of the present embodiment drives the reflection mirror 110 so that the traveling direction of the blue light B reflected by the reflecting mirror 110 (the traveling direction of the first light) changes with time. The driving element 111 is provided. The drive element 111 rotates the reflection mirror 110 around the rotation axis (first rotation axis) O1. In the present embodiment, the rotation axis O <b> 1 is set at the center of the reflection mirror 110. The rotation axis O1 is perpendicular to the paper surface of FIG.

  That is, in the present embodiment, the rotation axis O1 of the reflection mirror 110 is set in a direction that is approximately 90 ° different from the rotation axis O2 of the rotating fluorescent plate 34. Therefore, the optical path of the blue light B changes in the radial direction of the substrate 40 in the plane including the normal line of the substrate 40 (in the paper surface of FIG. 1). It is possible to change in the radial direction of the substrate 40.

  As shown in FIGS. 3A to 3C, the driving element 111 rotates around the rotation axis O1 to change the traveling direction of the blue light B reflected by the reflection mirror 110 with time.

  FIG. 3A shows a case where the blue light B is condensed on the center C of the phosphor layer 46. FIG. 3B shows a case where the traveling direction of the blue light B is changed to the right side of the pickup lens 90 as compared with FIG. 3A and is condensed on the right side portion of the center C of the phosphor layer 46. ing. FIG. 3C shows a case where the traveling direction of the blue light B is changed to the left side of the pickup lens 90 as compared with FIG. 3A and the blue light B is condensed on the left side portion of the center C of the phosphor layer 46. ing.

  Thus, in this embodiment, since the incident position BS of the blue light B on the surface of the phosphor layer 46 temporally changes in the radial direction of the substrate 40, the temperature of the phosphor layer 46 rises locally. It is prevented. Therefore, the phosphor layer 46 can efficiently generate the fluorescence Y.

  In the present embodiment, the drive element 111 drives the reflection mirror 110 so as to synchronize with the rotation of the substrate 40.

  FIG. 4 is a diagram showing the relationship between the irradiation position of the blue light B on the phosphor layer 46 and the rotation angle of the substrate 40. In FIG. 4, the horizontal axis indicates the irradiation position of the blue light B in the radial direction of the phosphor layer 46, and the vertical axis indicates the rotation angle (unit: °) of the substrate 40.

  When the irradiation position of the blue light B is not changed as in the prior art, the blue light B is always irradiated to the same position in the radial direction, and thus the phosphor layer 46 is likely to become high temperature.

  On the other hand, in the present embodiment, as shown in FIG. 4, while the substrate 40 is rotated once (rotation angle is 0 ° to 360 °), the left side of the phosphor layer 46 (for example, the inner peripheral side of the substrate 40) The reflection mirror 110 was controlled by the drive element 111 so that the right side (for example, the outer peripheral side of the substrate 40) was irradiated during the second rotation (rotation angle of 360 ° to 720 °). In this case, the substrate 40 is rotated twice after a specific portion of the phosphor layer 46 is irradiated with the blue light B until the next irradiation. Therefore, the specific portion can be sufficiently cooled while the substrate 40 rotates twice.

  The method for synchronizing the driving of the reflection mirror 110 with the rotation of the substrate 40 is not limited to the above.

  FIG. 5 is a diagram for explaining a synchronization method according to the modification, and is a diagram illustrating a relationship between the irradiation position of the blue light B on the phosphor layer 46 and the rotation angle of the substrate 40.

For example, as illustrated in FIG. 5, the irradiation position of the blue light B may be continuously changed by the driving element 111 while the substrate 40 rotates.
In most regions of the phosphor layer 46, the irradiation period of the blue light B corresponds to two rotation periods of the substrate 40. However, as shown in FIG. 5, a specific portion of the phosphor layer 46 is irradiated with the blue light B at a cycle of one rotation when the rotation angle is an integral multiple of 360 °. If averaged over time, the amount of blue light B applied to the specific part is twice the amount of blue light B applied to the other part. Therefore, the calorific value of a specific part is larger than the calorific value of other parts. Therefore, the occurrence of a problem that the temperature of the specific portion is greatly increased as compared with the other portions by reducing the output of the blue light B in accordance with the timing when the blue light B is applied to the specific portion. Can be suppressed.

  The fluorescence Y emitted from the phosphor layer 46 is taken into the pickup lens 90 and enters the reflection mirror 110.

  The fluorescence Y that has entered the reflection mirror 110 via the pickup lens 90 is reflected toward the dichroic mirror 80, is then reflected again by the dichroic mirror 80, and enters the first lens array 120. The first lens array 120 and the second lens array 130 constitute an integrator optical system in the scope of claims.

  In the present embodiment, the position where the principal ray of the blue light B is incident on the reflection mirror 110 or the point where the reflection mirror 110 and the optical axis of the blue light B intersect is provided at the focal position of the pickup lens 90. Therefore, the principal rays Bp of the blue light B reflected by the reflection mirror 110 and transmitted through the pickup lens 90 travel in directions parallel to each other regardless of the rotation angle of the reflection mirror 110. In the present embodiment, the principal ray Bp of the blue light B is vertically incident on the phosphor layer 46 regardless of the rotation angle of the reflection mirror 110. Since the principal ray Yp of the fluorescence Y is emitted perpendicularly from the phosphor layer 46, the optical path of the principal ray Bp can be traced in the reverse direction. That is, the principal ray Yp transmitted through the pickup lens 90 is incident on the incident position of the principal ray Bp on the reflection mirror 110. Accordingly, the principal ray Yp is reflected from the same position of the reflection mirror 110 in the same direction regardless of the rotation angle of the reflection mirror 110.

  According to this embodiment, the movement of the secondary light source image formed by the fluorescence Y on the first lens array 120 is suppressed. Therefore, since the fluorescence Y can be efficiently incident on the first lens array 120, high light utilization efficiency can be obtained.

  The first lens array 120 has a plurality of first small lenses 122 for dividing the fluorescence Y from the dichroic mirror 80 into a plurality of partial light beams. The plurality of first small lenses 122 are arranged in a matrix in a plane orthogonal to the illumination optical axis 101ax.

  The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The second lens array 130 forms an image of each first small lens 122 of the first lens array 120 together with the superimposing lens 150 in the vicinity of the image forming area of each liquid crystal light modulator 400R, 400G, 400B. The plurality of second small lenses 132 are arranged in a matrix in a plane orthogonal to the illumination optical axis 101ax.

  The polarization conversion element 140 includes a polarization separation layer, a reflection layer, and a retardation plate. The polarization conversion element 140 converts each partial light beam divided by the first lens array 120 into linearly polarized light.

  The superimposing lens 150 condenses the partial light beams from the polarization conversion element 140 and superimposes them in the vicinity of the image forming areas of the liquid crystal light modulation devices 400R, 400G, and 400B. The first lens array 120, the second lens array 130, and the superimposing lens 150 constitute an integrator optical system that makes the in-plane light intensity distribution of the light from the rotating fluorescent plate 30 uniform.

  The second illumination device 702 includes a second light source device 710, a condensing optical system 720, a scattering plate 730, a polarization conversion integrator rod 740, and a condensing lens 750.

  The second light source device 710 is a laser light source that emits blue light (emission intensity peak: about 445 nm). The second light source device 710 is disposed so that the optical axis is orthogonal to the illumination optical axis 702ax. The second light source device 710 may be composed of one laser light source or may be composed of many laser light sources. A light source device that emits blue light having a wavelength other than 445 nm (for example, 460 nm) can also be used.

  The condensing optical system 720 includes a first lens 722 and a second lens 724. The condensing optical system 720 causes the blue light to be incident on the scattering plate 730 in a substantially condensed state. The first lens 722 and the second lens 724 are convex lenses.

  The scattering plate 730 scatters the blue light from the second light source device 710 to make blue light having a light distribution similar to fluorescence (red light and green light emitted from the rotating fluorescent plate 32). As the scattering plate 730, for example, a microlens array can be used.

The polarization conversion integrator rod 740 makes the in-plane light intensity distribution of the blue light from the second light source device 710 uniform, and converts the blue light into linearly polarized light. The polarization conversion integrator rod 740 includes an integrator rod, a reflector that is disposed on the incident surface side of the integrator rod, has a small hole through which blue light is incident, and a reflective polarizing plate that is disposed on the exit surface side. A lens integrator optical system and a polarization conversion element can be used instead of the polarization conversion integrator rod.
The condensing lens 750 condenses the light from the polarization conversion integrator rod 740.

  The color separation light guide optical system 202 includes a dichroic mirror 210 and reflection mirrors 222, 230, and 250. The color separation light guide optical system 202 separates light (fluorescence Y) from the first illumination device 101 into red light R and green light G, and the liquid crystal light modulation device 400R to which the red light R and green light G respectively correspond. , 400G. Further, the color separation light guide optical system 202 guides the blue light from the second illumination device 702 to the liquid crystal light modulation device 400B.

  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, respectively.

  The dichroic mirror 210 is a dichroic mirror that transmits a red light component and reflects a green light component.

  The red light R that has passed 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 G reflected by the dichroic mirror 210 is further reflected by the reflection mirror 222, 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 B from the second illumination device 702 is reflected by the reflection mirror 250, passes through the condenser lens 300B, and enters the image forming area of the blue light liquid crystal light modulation device 400B.

  The liquid crystal light modulation devices 400R, 400G, and 400B modulate incident color light according to image information to form a color image. Although not shown, an incident-side polarizing plate is disposed between each condenser lens 300R, 300G, 300B and each liquid crystal light modulator 400R, 400G, 400B, and each liquid crystal light modulator 400R, Between the 400G and 400B and the cross dichroic prism 500, an exit side polarizing plate is disposed.

  The cross dichroic prism 500 combines the image lights emitted from the liquid crystal light modulation devices 400R, 400G, and 400B to form a color image. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on a substantially X-shaped interface in which the right-angle prisms are bonded together.

  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.

  As described above, according to the first illumination device 101 of the present embodiment, the fluorescence Y can be generated efficiently and the fluorescence Y can be used efficiently. In addition, the projector 1000 including the first illumination device 101 can display a bright high-quality image using high-output fluorescence.

(Second Embodiment)
FIG. 6 is a diagram showing an optical system of the projector 1001 according to the second embodiment. Members common to the projector 1000 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 6, the projector 1001 of this embodiment includes a third lighting device 103 and a fourth lighting device 704 instead of the first lighting device 101 and the second lighting device 702. In the present embodiment, the fourth illumination device 704 includes a drive reflecting mirror.

  The third illumination device 103 includes a light source device 10, a collimating optical system 70, a dichroic mirror 81, a collimating condensing optical system 91, a rotating fluorescent plate 34, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens. 150.

  The dichroic mirror 81 of the present embodiment crosses the optical axis of the light source device 10 and the illumination optical axis 103ax at an angle of 45 ° in the optical path from the collimating optical system 70 to the collimating condensing optical system 91. Has been placed. The dichroic mirror 81 reflects blue light and transmits red light and green light.

  The collimator condensing optical system 91 substantially collimates the fluorescence emitted from the phosphor layer 46 and the function of causing the blue light from the dichroic mirror 80 to enter the phosphor layer 46 of the rotating phosphor plate 34 in a substantially condensed state. With functions.

  The fourth illumination device 704 includes a fourth light source device 711, a polarization separation element 715, a reflection mirror 110 </ b> A, a drive element 111 </ b> A, a phase difference plate 716, a pickup lens 90, a rotation diffusion plate 731, and a superimposing optical system 735.

  The fourth light source device 711 is arranged so that the optical axis is orthogonal to the illumination optical axis 704ax. The fourth light source device 711 emits laser light having a peak wavelength of 460 nm, for example, as the blue light BL.

  The polarization separation element 715 is configured by, for example, a polarization beam splitter. In the present embodiment, the blue light BL is linearly polarized light. The polarization direction of the blue light BL coincides with the polarization direction of the P-polarized component transmitted through the polarization separation element 715.

  Therefore, the P-polarized blue light BLp incident on the polarization separation element 715 passes through the polarization separation element 715 and enters the reflection mirror 110A. The blue light BLp reflected by the reflecting mirror 110A enters the phase difference plate 716.

  The phase difference plate 716 is composed of a quarter-wave plate disposed in the optical path between the reflection mirror 110A and the pickup lens 90. Therefore, the P-polarized blue light BLp is incident on the phase difference plate 716, for example, converted into clockwise circularly-polarized blue light BLc, and then incident on the pickup lens 90.

  The pickup lens 90 collects the blue light BLc toward the rotating diffusion plate 731. The pickup lens 90 is a lens having a positive power, and has a function of causing the blue light BLc from the reflection mirror 110A to be incident on the diffuse reflection element 733 of the rotating diffusion plate 731 in a substantially condensed state, and from the diffuse reflection element 733. A function of collimating the emitted reflected light.

  The rotating diffusion plate 731 includes a disk-shaped substrate 732, a diffuse reflection element (light scattering element) 733 formed in a ring shape on the substrate 732, and a motor 734 that rotates the substrate 732. The diffuse reflection element 733 diffuses and reflects the blue light BLc emitted from the pickup lens 90 toward the pickup lens 90. For example, polished glass made of optical glass can be used. The rotational diffusion plate 731 is provided at the focal length of the pickup lens 90. Therefore, the pickup lens 90 can efficiently capture the diffuse reflection light from the diffuse reflection element 733.

  By the way, when the blue light B is incident on the diffuse reflection element 733 in a condensed state, the diffuse reflection element 733 generates heat locally. The product life may be shortened due to deformation caused by heat generation.

  On the other hand, the fourth illumination device 704 of the present embodiment drives the reflecting mirror 110A so that the traveling direction of the blue light B reflected by the reflecting mirror 110A (the traveling direction of the first light) changes with time. A driving element 111A is provided. The drive element 111A rotates the reflection mirror 110A around the rotation axis (first rotation axis) O1A. In the present embodiment, the rotation axis O1A is set at the center of the reflection mirror 110A. The rotation axis O1A is perpendicular to the paper surface of FIG.

That is, in the present embodiment, the rotation axis O1A of the reflection mirror 110A is set in a direction that is approximately 90 ° different from the rotation axis O2A of the rotation diffusion plate 731. Therefore, the optical path of the blue light B changes in the radial direction of the substrate 40 in the plane including the normal line of the substrate 732 (within the paper surface of FIG. 6). The radial direction of the substrate 732 can be changed.
The drive element 111A may drive the reflection mirror 110A in synchronization with the rotation of the substrate 732, as in the first embodiment.

  Thus, in this embodiment, since the incident position of the blue light B on the surface of the diffuse reflection element 733 changes with time in the radial direction of the substrate 732, the temperature of the diffuse reflection element 733 rises locally. It is prevented. Therefore, deterioration of the diffuse reflection element 733 can be suppressed.

  The blue light BLc ′ diffusely reflected by the rotating diffusion plate 731 is favorably converted from clockwise circularly polarized light to counterclockwise circularly polarized light. Therefore, by being incident on the phase difference plate 716 again, it is converted into S-polarized blue light BLs, then reflected by the reflecting mirror 110A, and further incident on the polarization separation element 715.

  The S-polarized blue light BLs is reflected by the polarization separation element 715 and enters the superimposing optical system 735. The superimposing optical system 735 includes an integrator optical system 736 and a superimposing lens 737. The integrator optical system 736 includes, for example, a lens array 736a and a lens array 736b. The lens arrays 736a and 736b are composed of a plurality of lenses arranged in an array. The superimposing lens 737 cooperates with the integrator optical system 736 to superimpose the illuminance distribution in the illuminated area by superimposing the S-polarized blue light BLs in the illuminated area.

  As described above, the fourth lighting device 704 can emit blue light B (blue light BLs). The blue light B from the fourth illumination device 704 is reflected by the reflection mirror 250, passes through the condenser lens 300B, and enters the image forming region of the blue light liquid crystal light modulation device 400B.

  Also in the present embodiment, the reflection mirror 110 is provided at the focal position of the pickup lens 90. Therefore, as in the first embodiment, the blue light BLs is efficiently taken into the integrator optical system 736, so that high light utilization efficiency can be obtained. In addition, since the incident position of the blue light BLc in the diffuse reflection element 733 is made different, the life of the rotating diffusion plate 731 can be extended.

  Therefore, according to the projector 1001 including the fourth illumination device 704 of the present embodiment, it is possible to display a bright high-quality image by efficiently using the blue light BL emitted from the fourth light source device 711. it can.

(Third embodiment)
FIG. 7 is a diagram showing an optical system of a projector 1002 according to the third embodiment. Members common to the projector 1000 according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 7, the projector 1002 of this embodiment includes a second lighting device 702 and a fifth lighting device 105.
The fifth illumination device 105 is different from the first illumination device 101 in that it includes a reflection mirror 83 instead of the dichroic mirror 80. Similar to the first illumination device 101, the fifth illumination device 105 emits light including red light and green light as illumination light.

  The reflection mirror 83 is disposed in the optical path from the collimating optical system 70 to the reflection mirror 110 so as to intersect at an angle of 45 ° with respect to each of the optical axis of the light source device 10 and the illumination optical axis 105ax. The reflection mirror 83 has a light transmission region 83a that transmits the blue light B, and reflects the fluorescence Y in a portion other than the light transmission region 83a. The light transmission region 83a is configured by, for example, a through hole provided in the reflection mirror 83.

  According to the fifth illumination device 105 of the present embodiment, the fluorescence Y can be generated efficiently and the fluorescence Y can be used efficiently, as with the first illumination device 101 of the first embodiment. Therefore, the projector 1002 provided with the fifth illumination device 105 can display a bright high-quality image using high-output fluorescence.

  In addition, this invention is not necessarily limited to the thing of the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

  For example, in the above embodiment, the rotating fluorescent plate 34 or the rotating diffusion plate 731 is taken as an example of the irradiation target for changing the incident position of the blue light B with time, but the present invention is not limited to this. That is, the incident position of the blue light with respect to the phosphor layer fixedly arranged or the diffuse reflection element fixedly arranged may be temporally changed.

  In this case, as shown in FIG. 8A, it is preferable to fix and arrange the irradiation target on the heat radiating plate 160. The heat sink 160 has a heat sink structure. For example, as shown in FIG. 8B, the blue light spot BA is reflected so as to scan in the order of upper left, upper right, lower left, and lower right as time elapses from t1 to t4 on the surface of the irradiation target. What is necessary is just to drive an element. The size of the irradiation target (side length) is at least twice the size of the blue light spot BA (side length). According to this, since the proportion of the blue light spot BA in the irradiation target can be reduced, the temperature increase in the irradiation target can be suppressed. Furthermore, according to this configuration, there is no region that is always irradiated with blue light while the blue light spot BA moves over the irradiation target. Therefore, the irradiation target does not generate large heat locally.

  In each of the above embodiments, the case where the driving elements 111 and 111A drive the reflection mirror 110 in synchronization with the rotation of the substrate 40 has been described as an example. However, the present invention is not limited to this. That is, the driving of the substrate 40 and the reflecting mirror 110 may not be synchronized.

  Moreover, in each said embodiment, although the light source device which consists of a laser light source was used, this invention is not limited to this. For example, you may use the light source device and 2nd light source device which consist of a light emitting diode.

  In each of the above embodiments, the liquid crystal light modulation device is used as the light modulation device, but the present invention is not limited to this. A digital micromirror device may be used as the light modulation device.

  Moreover, although the example which mounted the illuminating device of this invention in the projector was shown in the said embodiment, it is not restricted to this. The lighting device according to the present invention can also be applied to automobile headlamps, lighting equipment, and the like.

  BA ... blue light illumination area (first light spot), 10 ... light source device (light emitting element), 40,732 ... substrate, 46 ... phosphor layer (light scattering element), 80,81 ... dichroic mirror, 90 ... Pickup lens (lens having positive power), 101... 1st illumination device, 103... 3rd illumination device, 105... 5th illumination device, 110, 110A .. Reflection mirror (reflection element), 111, 111A. DESCRIPTION OF SYMBOLS 120 ... 1st lens array, 130 ... 2nd lens array, 400R, 400G, 400B ... Liquid crystal light modulation device, 600 ... Projection optical system, 702 ... 2nd illumination device, 704 ... 4th illumination device, 733 ... Diffuse reflection element (Light scattering element), 736 ... integrator optical system, 1000, 1001, 1002 ... projector.

Claims (8)

A light emitting element that emits first light;
A reflective element;
A driving element that drives the reflective element such that the traveling direction of the first light reflected by the reflective element changes with time;
A light scattering element that receives the first light reflected by the reflecting element and emits a second light;
A lens having a positive power provided on an optical path between the reflection element and the light scattering element, on which the first light and the second light are incident,
The lighting device configured such that the second light transmitted through the lens is incident on the reflective element. The illumination device according to claim 1, wherein the reflection element is provided at a focal position of the lens. A dichroic mirror that is provided between the light emitting element and the reflective element and separates the first light and the second light;
The illuminating device according to claim 1, further comprising an integrator optical system provided on an optical path of the second light separated by the dichroic mirror. The light scattering element is provided on a rotatable substrate;
The lighting device according to any one of claims 1 to 3, wherein the driving element drives the reflective element in synchronization with rotation of the substrate. The drive element rotates the reflection element with reference to a first rotation axis,
The lighting device according to claim 4, wherein the first rotation axis forms an angle of approximately 90 ° with the second rotation axis of the substrate. The lighting device according to claim 1, wherein the light emitting element changes an output of the first light in synchronization with rotation of the substrate. The illuminating device according to any one of claims 1 to 3, wherein the light scattering element is fixedly arranged and has a size that is at least twice that of the spot of the first light incident on the light scattering element. The lighting device according to any one of claims 1 to 7,
A light modulation device that forms image light by modulating light emitted from the illumination device according to image information; and
A projection optical system that projects the image light.

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