JP6565365B2 - Light source device, lighting device and projector - Google Patents

Description

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

  2. Description of the Related Art In recent years, attention has been paid to a light source device used for a projector, which uses a solid light source such as a semiconductor laser capable of obtaining light with high luminance and high output. As such a light source device, a device using a lens integrator in order to uniformly illuminate a phosphor layer with light from a plurality of solid state light sources is known (for example, see Patent Document 1).

JP2012-118110A

  By the way, when mounting a solid light source, it is inevitable that some variation (mounting variation) occurs in alignment. However, in the above prior art, since the mounting variation of the solid light source is not taken into consideration, the light utilization efficiency is lowered because the light of the solid light source cannot be used efficiently.

  SUMMARY An advantage of some aspects of the invention is that it provides a light source device that has high light utilization efficiency. Moreover, it aims at providing the illuminating device provided with the said light source device. Moreover, it aims at providing the projector provided with the said illuminating device.

According to the first aspect of the present invention, a first lens array including a light emitting element composed of a solid light source , a plurality of first small lenses on which light emitted from the light emitting element is incident, and the first lens array A second lens array including a plurality of second small lenses respectively provided in a subsequent stage and corresponding to the plurality of first small lenses, and a condensing optical system provided in a subsequent stage of the second lens array; A scattered light generation unit that is provided in a subsequent stage of the condensing optical system and into which light emitted from the light emitting element is incident, and a planar shape of a light emitting region of the light emitting element has a short direction and a long direction a rectangular shape, the planar shape of one second small lens of the plurality of second small lenses has a rectangular shape which have a lateral direction and a longitudinal direction, the longitudinal direction of the light exit region, the second light source device provided that matches the longitudinal direction of the small lenses It is.

  In the light source device according to the first aspect, the short-side direction of the light emission region intersects the long-side direction of the second small lens. Thereby, for example, even when a mounting error of the light emitting element occurs, the secondary light source image of the light emitted from the light emitting element is difficult to protrude from the second small lens. Therefore, since the light emitted from the light emitting element is efficiently incident on the scattered light generation unit, high light utilization efficiency can be obtained.

The first aspect further includes a declination prism disposed on a light incident side or a light emitting side of the first lens array, and the size of the second small lens in the longitudinal direction is the plurality of first small lenses. It is preferable that the size of the first small lens corresponding to the second small lens among the lenses is larger than the size in the longitudinal direction.
According to this configuration, the formation position of the secondary light source image on the second small lens can be adjusted by the deflection prism. Further, since the size of the second small lens in the longitudinal direction is larger than the size of the first small lens in the longitudinal direction, the protrusion of the secondary light source image on the second small lens can be suppressed.

In the first aspect, it is preferable that a deflection direction of the light by the declination prism is the longitudinal direction, and the deflection direction is a direction away from the optical axis of the light emitted from the light emitting element.
According to this configuration, it is possible to suppress the secondary light source image from protruding on each second small lens disposed in a direction away from the optical axis.

In the first aspect, it is preferable that the declination prism has a strip shape that is long in a direction perpendicular to the longitudinal direction.
According to this configuration, since the strip-shaped declination prism can be shared by the plurality of first small lenses in the short direction of the second small lens, the number of parts can be reduced.

In the first aspect, an optical axis of one first small lens among the plurality of first small lenses is decentered in the longitudinal direction, and the direction of decentering is the direction of the light emitted from the light emitting element. A direction away from the optical axis is preferred.
According to this configuration, it is possible to suppress the protrusion of the secondary light source image on the second small lens by the first small lens without using an optical element such as a deflection prism.

In the first aspect, it is preferable that the optical axis of the second small lens is eccentric in the longitudinal direction, and the direction of the eccentricity is a direction approaching the optical axis of the light emitted from the light emitting element. . In this case, it is desirable that the center of one first small lens corresponding to the second small lens among the plurality of first small lenses is on the optical axis of the second small lens.
If it does in this way, parallel light can be made to inject into a condensing optical system from the 2nd small lens.

  According to a second aspect of the present invention, there is provided an illuminating device comprising the light source device of the first aspect and a uniform illumination optical system into which light emitted from the light source device is incident.

  Since the illumination device according to the second aspect includes the light source device, the light use efficiency is high.

  According to a third aspect of the present invention, the illumination device according to the second 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 third aspect includes the illumination device, the light use efficiency is high.

FIG. 2 is a plan view illustrating a schematic configuration of the projector according to the first embodiment. The top view which shows schematic structure of the light source device of 1st Embodiment. The figure which planarly viewed the light emission area | region of the semiconductor laser of 1st Embodiment. The figure which shows the principal part structure of the light source device of a comparative example. (A), (b) is a top view of the 1st and 2nd lens array of a comparative example. (A), (b) is a top view of the 1st and 2nd lens array of 1st Embodiment. (A), (b) is a principal part block diagram of the homogenizer optical system of 1st Embodiment. (A), (b) is a principal part block diagram of the homogenizer optical system of 2nd Embodiment.

(First embodiment)
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.

(projector)
First, an example of the projector 1 shown in FIG. 1 will be described.
FIG. 1 is a plan view showing a schematic configuration of the projector 1.

  The projector 1 according to the present embodiment is a projection type image display device that displays a color video (image) on a screen (projection surface) SCR. The projector 1 uses three light modulation devices corresponding to each color light of red light LR, green light LG, and blue light LB. The projector 1 uses a semiconductor laser (laser light source) from which light with high luminance and high output can be obtained as a light source of an illumination device.

  Specifically, as shown in FIG. 1, the projector 1 includes an illumination device 2A, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a combining optical system 5, and a projection. And an optical system 6.

  The illumination device 2 </ b> A emits white light WL as illumination light toward the color separation optical system 3. The illumination device 2A includes the light source device 2 and the uniform illumination optical system 40.

  The uniform illumination optical system 40 includes an integrator optical system 31, a polarization conversion element 32, and a superimposing optical system 33. The polarization conversion element 32 is not essential. The uniform illumination optical system 40 uniformizes the intensity distribution of the white light WL emitted from the light source device 2 in the illuminated area. White light WL emitted from the uniform illumination optical system 40 enters the color separation optical system 3.

  The color separation optical system 3 is for separating the white light WL into the red light LR, the green light LG, and the blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a and a second dichroic mirror 7b, a first total reflection mirror 8a, a second total reflection mirror 8b, a third total reflection mirror 8c, and a first A relay lens 9a and a second relay lens 9b are roughly provided.

  The first dichroic mirror 7a has a function of separating the white light WL from the light source device 2 into red light LR and other light (green light LG and blue light LB). The first dichroic mirror 7a transmits the separated red light LR and reflects other light (green light LG and blue light LB). On the other hand, the second dichroic mirror 7b has a function of separating other light into green light LG and blue light LB. The second dichroic mirror 7b reflects the separated green light LG and transmits the blue light LB.

The first total reflection mirror 8a is disposed in the optical path of the red light LR, and reflects the red light LR transmitted through the first dichroic mirror 7a toward the light modulation device 4R. On the other hand, the second total reflection mirror 8b and the third total reflection mirror 8c are arranged in the optical path of the blue light LB, and direct the blue light LB transmitted through the second dichroic mirror 7b toward the light modulation device 4B. reflect.
It is not necessary to arrange a total reflection mirror in the optical path of the green light LG, and the green light LG is reflected toward the light modulation device 4G by the second dichroic mirror 7b.

  The first relay lens 9a and the second relay lens 9b are arranged on the light emission side of the second dichroic mirror 7b in the optical path of the blue light LB. The first relay lens 9a and the second relay lens 9b function to compensate for the optical loss of the blue light LB caused by the optical path length of the blue light LB being longer than the optical path lengths of the red light LR and the green light LG. have.

  The light modulation device 4R modulates the red light LR according to image information while allowing the red light LR to pass therethrough, and forms image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to image information while allowing the green light LG to pass therethrough, and forms image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to image information while allowing the blue light LB to pass therethrough, and forms image light corresponding to the blue light LB.

  For example, a transmissive liquid crystal panel is used for the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. In addition, a pair of polarizing plates (not shown) are arranged on the incident side and the emission side of the liquid crystal panel so that only linearly polarized light in a specific direction passes therethrough.

  A field lens 10R, a field lens 10G, and a field lens 10B are disposed on the incident side of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, respectively. The field lens 10R, the field lens 10G, and the field lens 10B are for parallelizing the red light LR, the green light LG, and the blue light LB incident on the respective light modulation devices 4R, 4G, and 4B. It is.

  The combining optical system 5 combines the image light corresponding to the red light LR, the green light LG, and the blue light LB when the image light from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B enters. The combined image light is emitted toward the projection optical system 6. For example, a cross dichroic prism is used for the combining optical system 5.

  The projection optical system 6 is composed of a projection lens group. The projection optical system 6 enlarges and projects the image light combined by the combining optical system 5 toward the screen SCR. Thereby, an enlarged color video (image) is displayed on the screen SCR.

(Light source device)
Next, a specific embodiment of a light source device to which one aspect of the present invention used for the illumination device 2A is applied will be described. Hereinafter, each configuration of the light source device will be described using an XYZ coordinate system as necessary.

  FIG. 2 is a plan view showing a schematic configuration of the light source device 2. In FIG. 2, the X direction is a direction parallel to the optical axis ax1, the Y direction is a direction parallel to the optical axis ax2 orthogonal to the optical axis ax1, and the Z direction is orthogonal to the X direction and the Y direction. Direction.

  As shown in FIG. 2, the light source device 2 includes an array light source 21, a collimator optical system 22, an afocal optical system 23, a first phase difference plate 15, a homogenizer optical system 24, and a polarization separation element 50A. The optical element 25 </ b> A including the first condensing optical system 26, the fluorescent light emitting element 27, the second retardation plate 28, the second condensing optical system 29, and the diffuse reflection element 30 are schematically illustrated. I have.

The array light source 21 of the present embodiment corresponds to a “light emitting element” in the claims.
The fluorescent light-emitting element 27 or the diffuse reflection element 30 of the present embodiment corresponds to a “scattered light generation unit” in the claims.

  Among these components, the array light source 21, the collimator optical system 22, the afocal optical system 23, the first phase difference plate 15, the homogenizer optical system 24, the optical element 25A, the second position, and the like. The phase difference plate 28, the second condensing optical system 29, and the diffuse reflection element 30 are sequentially arranged on the optical axis ax1. On the other hand, the fluorescent light emitting element 27, the first condensing optical system 26, and the optical element 25A are sequentially arranged on the optical axis ax2. The optical axis ax1 and the optical axis ax2 are in the same plane and are in a positional relationship orthogonal to each other.

  The array light source 21 includes a plurality of semiconductor lasers 211 as solid-state light sources. The plurality of semiconductor lasers 211 are arranged in an array in the same plane orthogonal to the optical axis ax1. The semiconductor laser 211 emits, for example, a blue light beam BL (for example, a laser beam having a peak wavelength of 460 nm). In the present embodiment, the array light source 21 emits a light bundle K1 composed of a plurality of light beams BL.

  FIG. 3 is a plan view of the light emission region of the semiconductor laser 211. As shown in FIG. 3, the light emission region 211A of the semiconductor laser 211 has, for example, a substantially rectangular planar shape having a longitudinal direction and a lateral direction. The longitudinal direction of the light emission region 211A corresponds to the direction along the optical axis ax2 (Y direction) shown in FIG. Further, the short side direction of the light emission region 211A corresponds to the direction along the Z direction.

  Returning to FIG. 2, the light beam K <b> 1 emitted from the array light source 21 enters the collimator optical system 22. The collimator optical system 22 converts the light beam K1 emitted from the array light source 21 into a parallel light beam. The collimator optical system 22 is composed of, for example, a plurality of collimator lenses 22a arranged in an array. Each of the plurality of collimator lenses 22 a is arranged corresponding to the plurality of semiconductor lasers 211.

  The light beam K <b> 1 that has passed through the collimator optical system 22 enters the afocal optical system 23. The afocal optical system 23 is for adjusting the beam diameter of the light beam K1. The afocal optical system 23 includes, for example, a convex lens 23a and a concave lens 23b.

  The light bundle K1 that has been afocal optical system 23 is incident on the first retardation plate 15. The first retardation plate 15 is, for example, a half-wave plate that can be rotated. The light beam BL emitted from the semiconductor laser 211 is linearly polarized light. By appropriately setting the rotation angle of the half-wave plate, the light BL transmitted through the first retardation plate 15 includes light (including a S-polarized component and a P-polarized component with respect to the optical element 25A) in a predetermined ratio ( The light flux K1). By rotating the first retardation plate 15, the ratio of the S-polarized component and the P-polarized component can be changed.

  By passing through the first retardation plate 15, the light beam K 1 including the S-polarized component light beam BLs and the P-polarized component light beam BLp is incident on the homogenizer optical system 24. The homogenizer optical system 24 makes the illuminance distribution due to the light bundle BLs on the phosphor layer 34 uniform in cooperation with the first condensing optical system 26. Further, the homogenizer optical system 24 cooperates with the second condensing optical system 29 to uniformize the illuminance distribution due to the light beam BLc ′ on the diffuse reflector 30A described later. The homogenizer optical system 24 includes, for example, a first lens array 24a and a second lens array 24b. The first lens array 24a includes a plurality of first small lenses 24am, and the second lens array 24b includes a plurality of second small lenses 24bm. The plurality of second small lenses 24bm correspond to the plurality of first small lenses 24am, respectively.

  The first lens array 24a (first small lens 24am) and the fluorescent light emitting element 27 or the diffuse reflection element 30 are disposed at positions that are optically conjugate. In addition, the light emission region 211A of the semiconductor laser 211 and the second lens array 24b are disposed at optically conjugate positions.

  By the way, in the light source device 2 including the semiconductor laser 211 arranged in an array and the collimator lens 22a arranged in an array as in the present embodiment, there is a slight shift in the alignment of the semiconductor laser 211 or the collimator lens 22a. Inevitable. That is, in the present embodiment, the light source device 2 has a slight mounting error.

  Here, the effect of the light source device 2 of the present embodiment will be described with reference to a comparative example.

  FIG. 4 is a diagram illustrating a main configuration of the light source device 2 ′ according to the comparative example. 4 has the same configuration as that of the light source device 2 of the present embodiment except that the homogenizer optical system 24 is replaced with a homogenizer optical system 124. In FIG. 4, only the homogenizer optical system 124, the array light source 21, and the collimator lens 22a are illustrated.

  The homogenizer optical system 124 includes a first lens array 124a including a plurality of first small lenses 124am, and a second lens array 124b including a plurality of second small lenses 124bm.

  When the above mounting error occurs in the homogenizer optical system 124, the uniformity of the illuminance distribution due to the light beam BLs on the phosphor layer 34 decreases. This is because the position of the secondary light source image G formed on the second small lens 124bm by the light beam BL emitted from the light emission region 211A is shifted from the predetermined position of the second small lens 124bm.

  As described above, when the planar shape of the light emission region 211A is a shape having a longitudinal direction in the Y direction (for example, a rectangle), the secondary light source image G formed on the second small lens 124bm that is optically conjugate. Becomes a shape having a longitudinal direction in the Y direction (rectangular shape).

  Here, the movement of the secondary light source image on the second small lens 124bm due to the mounting error occurs at the same rate in each direction.

  FIG. 5A is a plan view of the first lens array 124a viewed from the + X direction, and FIG. 5B is a plan view of the second lens array 124b viewed from the + X direction.

  As shown in FIGS. 5A and 5B, in the homogenizer optical system 124, the size of the first small lens 124am is the same as the size of the second small lens 124bm. Specifically, the planar shape of the first small lens 124am and the planar shape of the second small lens 124bm are both squares whose length in the Y direction is equal to the length in the Z direction.

  When a mounting error occurs, the secondary light source image G deviates from a predetermined position. As can be seen from FIG. 5B, when the secondary light source image G is shifted in the longitudinal direction (Y direction) of the light emission region 211A, it protrudes from the second small lens 124bm than when it is shifted in the Z direction. Cheap. When the secondary light source image G protrudes from the second small lens 124bm, the light from the array light source 21 cannot be used efficiently, and the light use efficiency is lowered.

  In order to solve this problem, the light source device 2 of the present embodiment includes a homogenizer optical system 24 including a second small lens 24bm having a rectangular planar shape having a longitudinal direction and a lateral direction.

  FIG. 6A is a plan view of the first lens array 24a viewed from the + X direction, and FIG. 6B is a plan view of the second lens array 24b viewed from the + X direction.

As shown in FIG. 6A, the planar shape of the first small lens 24am of the first lens array 24a is a square whose length in the Y direction is equal to the length in the Z direction.
On the other hand, as shown in FIG. 6B, the planar shape of the second small lens 24bm of the second lens array 24b is a rectangle (rectangular) having a long side along the Y direction and a short side along the Z direction. ). Thus, in the present embodiment, the size of the second small lens 24bm in the longitudinal direction (Y direction) is larger than the size of the first small lens 24am in the Y direction.

  FIG. 7 is a diagram showing a configuration of a main part of the homogenizer optical system 24. FIG. 7A is a plan view when the homogenizer optical system 24 is viewed from the + Z direction, and FIG. It is a side view at the time of seeing the homogenizer optical system 24.

  In the present embodiment, a plurality of declination prisms 41 are arranged on the light exit side of the first small lens 24am. As shown in FIG. 7A, the declination prism 41 is arranged in each of lens rows 24L1, 24L2, 24L3, and 24L4 in which a plurality of first small lenses 24am are arranged in the Z direction.

  As shown in FIG. 7B, the declination prism 41 has a strip shape that is long in the short direction (Z direction) of the second small lens 24bm. Therefore, in each of the lens rows 24L1, 24L2, and 24L3 (collectively referred to as the lens row 24L), one declination prism is used for a plurality of (for example, four in this embodiment) first small lenses 24am. 41 is provided. In this way, the number of parts can be reduced by using one declination prism 41 for the plurality of first small lenses 24am.

  The declination prism 41 includes a prism surface 41a having a deflection characteristic that changes the traveling direction of light (a part of the light beam K1s of the light beam K1) on the second small lens 24bm side. The deflection direction by the prism surface 41a is the longitudinal direction (Y direction) of the second small lens 24bm, specifically, the direction away from the optical axis ax1.

  The declination prism 41 deflects the light K1s in the direction away from the optical axis ax1 (Y direction or -Y direction). However, the distance between the imaging position of the light K1s emitted from the first small lens 24am and the surface on which the plurality of first small lenses 24am are provided does not change. The distance between the first lens array 24a and the second lens array 24b is adjusted so as not to disturb the conjugate relationship established between the first small lens 24am and the fluorescent light emitting element 27 or the diffuse reflection element 30. Yes. In the present embodiment, if there is no mounting error, the declination prism 41 has a secondary light source image G at the center of the second small lens 24bm corresponding to the first small lens 24am that has emitted the light K1s. Designed to form

The second small lens 24bm is composed of an eccentric lens whose optical axis is decentered.
Specifically, as shown in FIG. 7A, the optical axis B2 of the second small lens 24bm is eccentric in the longitudinal direction (Y direction) of the second small lens 24bm. The eccentric direction of the optical axis B2 is set to a direction approaching the optical axis ax1 of the light emitted from the array light source 21.

  In the present embodiment, the optical axis B1 of the first small lens 24am is located on the optical axis B2 of the second small lens 24bm. Accordingly, the second small lens 24bm can convert the light K1s emitted from the first small lens 24am into parallel light and emit the parallel light.

  In the present embodiment, the short direction (Z direction) of the light emission region 211A is orthogonal (crossed) to the long direction (Y direction) of the second small lens 24bm. That is, the longitudinal direction (Y direction) of the light emission region 211A coincides with the longitudinal direction (Y direction) of the second small lens 24bm.

  The longitudinal direction of the secondary light source image G formed on the second small lens 24bm substantially coincides with the longitudinal direction of the second small lens 24bm. Further, since the deflection angle prism 41 is provided, the secondary light source image G is formed at a predetermined position of the second small lens 24bm, for example, at the central portion.

  In the present embodiment, the size of the second small lens 24bm in the Y direction is larger than the size of the second small lens 24bm in the Z direction. Therefore, even if the secondary light source image G shifts in the Y direction, which is likely to occur in the prior art, the secondary light source image G is unlikely to protrude from the second small lens 24bm, and the secondary light source image on the second small lens 24bm. G is formed satisfactorily. Therefore, the light from the array light source 21 can be used efficiently. Further, since high mounting accuracy is not required as in the prior art, manufacturing is facilitated and cost reduction can be achieved.

  As described above, since the light K1s emitted from each second small lens 24bm is parallel light, fluorescence is emitted via the first condensing optical system 26 or the second condensing optical system 29 described later. The light is condensed well on the element 27 or the diffuse reflection element 30.

  The optical element 25A is composed of, for example, a dichroic prism having wavelength selectivity. The dichroic prism has an inclined surface K that forms an angle of 45 ° with the optical axis ax1. The inclined surface K forms an angle of 45 ° with respect to the optical axis ax2. The optical element 25A is arranged so that the intersection of the optical axes ax1 and ax2 orthogonal to each other coincides with the optical center of the inclined surface K. The optical element 25A is not limited to a prism shape such as a dichroic prism, and a parallel plate dichroic mirror may be used.

  On the inclined surface K, a polarization separation element 50A having wavelength selectivity is provided. The polarization separation element 50A has a polarization separation function for separating the light beam K1 that has passed through the first retardation plate 15 into an S-polarization component and a P-polarization component for the polarization separation element 50A. Specifically, the polarization separation element 50A reflects the S-polarized light beam BLs of the incident light (light bundle K1) and transmits the P-polarized light beam BLp of the incident light.

  The light beam BLs that is the S-polarized component is reflected by the polarization separation element 50 </ b> A and travels toward the fluorescent light emitting element 27. The light beam BLp, which is a P-polarized component, passes through the polarization separation element 50A and travels toward the diffuse reflection element 30.

  The polarization separation element 50A has a color separation function that transmits fluorescent light YL, which will be described later, having a wavelength band different from that of the light beam K1, regardless of the polarization state.

  The S-polarized light beam BLs emitted from the polarization separation element 50 </ b> A is incident on the first condensing optical system 26. The first condensing optical system 26 condenses the light beam BLs toward the phosphor layer 34 of the fluorescent light emitting element 27. The first condensing optical system 26 includes, for example, pickup lenses 26a and 26b.

  The light beam BLs emitted from the first condensing optical system 26 enters the fluorescent light emitting element 27. The fluorescent light emitting element 27 includes a phosphor layer 34, a substrate 35 that supports the phosphor layer 34, and a fixing member 36 that fixes the phosphor layer 34 to the substrate 35.

  In the fluorescent light emitting element 27, a fixing provided between the side surface of the phosphor layer 34 and the substrate 35 in a state where the surface of the phosphor layer 34 opposite to the side on which the light beam BLs is incident is in contact with the substrate 35. The phosphor layer 34 is fixedly supported on the substrate 35 by the member 36.

  The phosphor layer 34 includes phosphor particles that absorb the light beam BLs, convert it into yellow fluorescent light YL, and emit the yellow fluorescent light YL. As the phosphor particles, for example, YAG (yttrium / aluminum / garnet) phosphors can be used. In addition, the material for forming the phosphor particles may be one kind, or a mixture of particles formed using two or more kinds of materials may be used as the phosphor particles.

  For the phosphor layer 34, it is preferable to use a layer excellent in heat resistance and surface processability. As such a phosphor layer 34, for example, a phosphor layer in which phosphor particles are dispersed in an inorganic binder such as alumina, a phosphor layer in which phosphor particles are sintered without using a binder, and the like are preferably used. be able to.

  A reflective portion 37 is provided on the side of the phosphor layer 34 opposite to the side on which the light beam BLs is incident. The reflection unit 37 has a function of reflecting a part of the fluorescent light YL among the fluorescent light YL generated by the phosphor layer 34.

  It is preferable that the reflection part 37 consists of a specular reflection surface. In the fluorescent light emitting element 27, the fluorescent light YL generated in the fluorescent material layer 34 is specularly reflected by the reflecting portion 37, whereby the fluorescent light YL can be efficiently emitted from the fluorescent material layer 34.

  Specifically, the reflecting portion 37 can be configured by providing a reflecting film 37a on the surface of the phosphor layer 34 opposite to the side on which the light beam BLs is incident. In this case, the surface of the reflective film 37a facing the phosphor layer 34 is a specular reflection surface. The reflection part 37 may be configured such that the substrate 35 is made of a base material having light reflection characteristics. In this case, the reflective film 37a is omitted, and the surface of the substrate 35 facing the phosphor layer 34 is made into a mirror surface, so that this surface can be used as a mirror reflection surface.

  For the fixing member 36, it is preferable to use an inorganic adhesive having light reflection characteristics. In this case, the light leaking from the side surface of the phosphor layer 34 can be reflected into the phosphor layer 34 by the inorganic adhesive having light reflection characteristics. Thereby, the light extraction efficiency of the fluorescent light YL generated by the phosphor layer 34 can be further increased.

  A heat sink 38 is disposed on the surface of the substrate 35 opposite to the surface that supports the phosphor layer 34. In the fluorescent light emitting element 27, heat can be radiated through the heat sink 38, and thus thermal deterioration of the phosphor layer 34 can be prevented.

  Of the fluorescent light YL generated in the phosphor layer 34, a part of the fluorescent light YL is reflected by the reflecting portion 37 and emitted to the outside of the phosphor layer 34. In addition, among the fluorescent light YL generated in the fluorescent material layer 34, another part of the fluorescent light YL is emitted outside the fluorescent material layer 34 without passing through the reflecting portion 37. In this way, the fluorescent light YL is emitted from the phosphor layer 34 toward the first condensing optical system 26.

  The fluorescent light YL emitted from the phosphor layer 34 passes through the first condensing optical system 26 and the polarization separation element 50A.

  On the other hand, the P-polarized light beam BLp emitted from the polarization separation element 50 </ b> A is incident on the second retardation plate 28. The second retardation plate 28 is composed of a ¼ wavelength plate (λ / 4 plate) disposed in the optical path between the polarization separation element 50 </ b> A and the diffuse reflection element 30. The light beam BLp is converted into a circularly polarized light beam BLc ′ by passing through the second retardation plate 28. The light beam BLc ′ that has passed through the second retardation plate 28 enters the second condensing optical system 29.

  The second condensing optical system 29 condenses the light beam BLc ′ toward the diffuse reflection element 30. The second condensing optical system 29 includes, for example, a pickup lens 29a and a pickup lens 29b.

  The diffuse reflection element 30 diffuses and reflects the light beam BLc ′ emitted from the second condensing optical system 29 toward the polarization separation element 50A. Among them, as the diffuse reflection element 30, it is preferable to use an element that causes Lambertian reflection of the light beam BLc ′ incident on the diffuse reflection element 30.

  The diffuse reflection element 30 includes a diffuse reflection plate 30A and a drive source 30M such as a motor for rotating the diffuse reflection plate 30A. The rotation axis of the drive source 30M is disposed substantially parallel to the optical axis ax1. Thereby, the diffuse reflection plate 30A is configured to be rotatable in a plane intersecting with the principal ray of the light beam BLc ′ incident on the diffuse reflection plate 30A. The diffuse reflection plate 30A is formed, for example, in a circular shape when viewed from the direction of the rotation axis.

  The circularly polarized light beam BLc ′ reflected by the diffuse reflection plate 30A and transmitted again through the second condensing optical system 29 is transmitted through the second retardation plate 28 again to become an S-polarized light beam BLs ′.

  The light beam BLs ′ (blue light) emitted from the diffuse reflection element 30 is combined with the fluorescent light YL transmitted through the polarization separation element 50A, and white white light WL is obtained. The white light WL is incident on the uniform illumination optical system 40 (integrator optical system 31) shown in FIGS. The integrator optical system 31 cooperates with the superimposing optical system 33 to uniformize the illuminance distribution by the white light WL in the illuminated area.

  The integrator optical system 31 includes, for example, a lens array 31a and a lens array 31b. The lens arrays 31a and 31b are composed of a plurality of lenses arranged in an array.

  The white light WL that has passed through the integrator optical system 31 enters the polarization conversion element 32. The polarization conversion element 32 includes, for example, a polarization separation film and a phase difference plate, and converts the white light WL into linearly polarized light.

  The white light WL that has passed through the polarization conversion element 32 enters the superimposing optical system 33. The superimposing optical system 33 is composed of, for example, a superimposing lens, and superimposes the white light WL emitted from the polarization conversion element 32 on the illuminated area. In this embodiment, the illuminance distribution in the illuminated area is made uniform by the integrator optical system 31 and the superimposing optical system 33.

  As described above, according to the present embodiment, the light emitted from the array light source 21 is efficiently incident on the fluorescent light-emitting element 27 or the diffuse reflection element 30, so that the light utilization efficiency is high. Therefore, bright illumination light can be obtained. Therefore, according to the projector 1 of the present embodiment, the display quality is excellent due to the bright illumination light.

(Second Embodiment)
Next, the homogenizer optical system according to the second embodiment will be described. In addition, the same code | symbol is attached | subjected about the same structure and member as the said embodiment, and the description is abbreviate | omitted or simplified.

  FIG. 8 is a diagram showing a configuration of a main part of the homogenizer optical system 224 of the present embodiment. FIG. 8A is a plan view when the homogenizer optical system 224 is viewed from the + Z direction, and FIG. It is a side view at the time of seeing the homogenizer optical system 224 from -Y direction.

  The homogenizer optical system 224 of the present embodiment includes a first lens array 224a and a second lens array 224b. The first lens array 224a has a plurality of first small lenses 224am, and the second lens array 224b has a plurality of second small lenses 224bm. The second lens array 224b has the same configuration as the second lens array 24b of the above embodiment.

  Also in this embodiment, the size of the second small lens 224bm in the longitudinal direction (Y direction) is larger than the size of the first small lens 224am in the Y direction.

  In the homogenizer optical system 224 of the present embodiment, an eccentric lens whose optical axis is decentered is used as the first small lens 224am. Specifically, as shown in FIG. 8A, the first small lens 224am has its optical axis B1 decentered in the Y direction. The eccentric direction of the optical axis B1 is set in a direction away from the optical axis ax1 of the light emitted from the array light source 21.

  The first small lens 224am has the same deflection function as the declination prism 41 of the above embodiment, and deflects the light K1s in the direction away from the optical axis ax1 (Y direction or -Y direction). However, the distance between the imaging position of the light K1s emitted from the first small lens 224am and the surface on which the plurality of first small lenses 224am are provided does not change. The interval between the first lens array 224a and the second lens array 224b is adjusted so as not to disturb the conjugate relationship established between the first small lens 224am and the fluorescent light emitting element 27 or the diffuse reflection element 30. Yes. In the present embodiment, if there is no mounting error, the first small lens 224am has a secondary light source image at the center of the second small lens 224bm corresponding to the first small lens 224am that has emitted the light K1s. Designed to form

  Also in this embodiment, the optical axis B1 of the first small lens 224am is positioned on the optical axis B2 of the second small lens 224bm. Accordingly, the second small lens 224bm can convert the light K1s emitted from the first small lens 224am into parallel light and emit the parallel light.

  The longitudinal direction of the secondary light source image G formed on the second small lens 224bm substantially coincides with the longitudinal direction of the second small lens 224bm. Further, the secondary light source image G is formed at a predetermined position of the second small lens 224bm, for example, at the central portion.

  Also in this embodiment, since the protrusion of the secondary light source image G from the second small lens 224bm due to the mounting error is suppressed, the light from the array light source 21 can be used efficiently. Therefore, high light utilization efficiency can be obtained.

  In addition, this invention is not necessarily limited to the structure 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 first embodiment, the case where the deflection prism 41 is disposed on the light exit side of the first small lens 24am is described as an example, but the deflection prism 41 is disposed on the light incident side of the first small lens 24am. It may be arranged.

  In the above embodiment, the case where the longitudinal direction of the light emission region 211A coincides with the longitudinal direction of the second small lens 24bm is described as an example, but the present invention is not limited to this. That is, in the present invention, it is only necessary that the longitudinal direction of the light emission region 211A intersects the short direction of the second small lens 24bm. In other words, the longitudinal direction of the light emission region 211A and the short direction of the second small lens 24bm may not coincide with each other.

In addition, the shape, number, arrangement, material, and the like of the various components of the lighting device and the projector are not limited to the above-described embodiment, and can be changed as appropriate.
Moreover, although the example which mounted the illuminating device by 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 lighting fixtures, automobile headlights, and the like.

DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Light source device, 2A ... Illumination device, 4R, 4G, 4B ... Light modulation device, 6 ... Projection optical system, 21 ... Array light source, 24a, 124a ... 1st lens array, 24am, 124am ... 1st 1 small lens, 24b, 124b ... second lens array, 24bm, 124bm ... second small lens, 26 ... first condensing optical system, 27 ... fluorescent light emitting element, 29 ... second condensing optical system, 30 ... Diffuse reflection element, 33 ... Superimposing optical system, 41 ... Deflection prism, 211A ... Light exit area, B1, B2 ... Optical axis, C1, C2 ... Center of lens.

Claims (9)

A light emitting device comprising a solid light source ;
A first lens array including a plurality of first small lenses on which light emitted from the light emitting elements is incident;
A second lens array provided at a subsequent stage of the first lens array and including a plurality of second small lenses respectively corresponding to the plurality of first small lenses;
A condensing optical system provided downstream of the second lens array;
A scattered light generation unit that is provided at a subsequent stage of the condensing optical system and into which light emitted from the light emitting element is incident;
The planar shape of the light emitting region of the light emitting element is a rectangular shape having a short side direction and a long side direction ,
The planar shape of one second small lens of the plurality of second small lenses has a rectangular shape which have a lateral direction and a longitudinal direction,
A light source device in which a longitudinal direction of the light emission region coincides with a longitudinal direction of the second small lens . A declination prism disposed on the light incident side or the light exit side of the first lens array;
The size in the longitudinal direction of the second small lens is larger than the size in the longitudinal direction of the first small lens corresponding to the second small lens among the plurality of first small lenses. Light source device. The deflection direction of the light by the declination prism is the longitudinal direction of the second small lens ,
The light source device according to claim 2, wherein the deflection direction is a direction away from the optical axis of the light emitted from the light emitting element. The light source device according to claim 2 , wherein the declination prism has a strip shape that is long in a short direction of the second small lens . The optical axis of one first small lens among the plurality of first small lenses is decentered in the longitudinal direction of the second small lens ,
The light source device according to claim 1, wherein the direction of the eccentricity is a direction away from the optical axis of the light emitted from the light emitting element. The optical axis of the second small lens is decentered in the longitudinal direction of the second small lens ,
The light source device according to claim 1, wherein the direction of the eccentricity is a direction approaching an optical axis of the light emitted from the light emitting element. The light source device according to claim 6, wherein a center of one first small lens corresponding to the second small lens among the plurality of first small lenses is on an optical axis of the second small lens. The light source device according to any one of claims 1 to 7,
And a uniform illumination optical system into which the light emitted from the light source device is incident. A lighting device according to claim 8;
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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