Light source apparatus and projector

The present disclosure relates to a light source apparatus including a laser light source that outputs a laser beam and a collimator system that parallelizes the laser beam. The collimator system includes three lens groups. A first group includes a first anamorphic lens having negative power in a first direction. A second group includes a second anamorphic lens having positive power in a second direction perpendicular to the first direction. A third group includes a third anamorphic lens having positive power in the first direction.

The present application is based on, and claims priority from JP Application Serial Number 2019-007797, filed Jan. 21, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND

1. Technical Field

The present disclosure relates to a light source apparatus and a projector.

2. Related Art

As a light source apparatus used in a projector, there is a technology of related art for causing a laser beam outputted from a laser light source to be efficiently incident on a lens array by using two cylindrical lenses having cylindrical surfaces perpendicular to each other to convert the light flux shape of the laser beam into a substantially circular shape (see JP-A-2017-211417, for example).

In the light source apparatus described above, a large difference between the maximum and minimum of the angle of divergence of the laser beam requires a large distance between the two cylindrical lenses to convert the light flux shape of the laser beam into a substantially circular shape. The large distance causes a problem of an increase in the size of the light source apparatus.

SUMMARY

According to a first aspect of the present disclosure, there is provided a light source apparatus including a laser light source that outputs a laser beam and a collimator system that parallelizes the laser beam. The collimator system is formed of three lens groups. The first group includes a first anamorphic lens having negative power in a first direction. The second group includes a second anamorphic lens having positive power in a second direction perpendicular to the first direction. The third group includes a third anamorphic lens having positive power in the first direction.

In the first aspect described above, the first anamorphic lens maybe formed of a first cylindrical lens, the second anamorphic lens may be formed of a second cylindrical lens, and the third anamorphic lens may be formed of a third cylindrical lens.

In the first aspect described above, the laser light source may have a rectangular light emission area having long sides extending in the first direction and short sides extending in the second direction, the second cylindrical lens may have a generatrix extending in the first direction, and the first and third cylindrical lenses may each have a generatrix extending in the second direction.

In the first aspect described above, the first group may be formed of a biconcave lens.

In the first aspect described above, the second group may be formed of a convex lens, and the convex lens may be so configured that at least a light-exiting-side lens surface is formed of an aspheric surface.

In the first aspect described above, the second group may be formed of a planoconvex lens having a flat light incident surface.

In the first aspect described above, the third group may be formed of a convex lens, and the convex lens may be so configured that at least a light-exiting-side lens surface is formed of an aspheric surface.

In the first aspect described above, the third group may be formed of a planoconvex lens having a flat light incident surface.

According to a second aspect of the present disclosure, there is provided a projector including the light source apparatus according to the first aspect, a light modulator that modulates light from the light source apparatus in accordance with image information to form image light, and a projection optical apparatus that projects the image light.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the drawings used in the following description, a characteristic portion is enlarged for convenience in some cases for clarity of the characteristic thereof, and the dimension ratio and other factors of each component are therefore not always equal to actual values.

First Embodiment

FIG.1shows a schematic configuration of a projector according to the present embodiment.

A projector1according to the present embodiment is a projection-type image display apparatus that projects color video images on a screen SCR, as shown inFIG.1. The projector1includes a first light source apparatus2A, a second light source apparatus2B, a color separation system3, a light modulator4R, a light modulator4G, a light modulator4B, a light combining system5, a projection optical apparatus6, and a total reflection mirror8a.

The first light source apparatus2A outputs blue light LB. The blue light LB is totally reflected of the total reflection mirror8aand incident on the light modulator4B. The second light source apparatus2B outputs yellow fluorescence YL. The yellow fluorescence YL is separated by the color separating system3into red light LR and green light LG.

The color separating system3includes a dichroic mirror7aand total reflection mirrors8band8c.Red, green, and blue are hereinafter collectively called RGB in some cases.

The dichroic mirror7aseparates the yellow fluorescence YL from the second light source apparatus2B into the red light LR and the green light LG. The dichroic mirror7areflects the red light LR and transmits the green light LG. The total reflection mirror8breflects the red light LR toward the light modulator4R. The total reflection mirror8cguides the green light LG to the light modulator4G.

The light modulator4R modulates the red light LR in accordance with image information to form red image light. The light modulator4G modulates the green light LG in accordance with image information to form green image light. The light modulator4B modulates the blue light LB in accordance with image information to form blue image light.

The light modulators4R,4G, and4B are each formed, for example, of a transmissive liquid crystal panel. Polarizers (not shown) are disposed on the light incident side and the light exiting side of each of the liquid crystal panels.

Field lenses10R,10G, and10B are disposed on the light incident side of the light modulators4R,4G, and4B, respectively.

The image light outputted from each of the light modulators4R,4G, and4B enters the light combining system5. The light combining system5combines the image light from the light modulator4R, the image light from the light modulator4G, and the image light from the light modulator4B with one another and causes the combined image light to exit toward the projection optical apparatus6. The light combining system5is formed, for example, of a cross dichroic prism.

The projection optical apparatus6is formed of a projection lens group, enlarges the combined image light from the light combining systems5, and projects the enlarged image light toward the screen SCR. Enlarged color video images are thus displayed on the screen SCR.

The first light source apparatus2A will subsequently be described.

FIG.2shows the configuration of the first light source apparatus2A. The first light source apparatus2A includes a laser light source20B, a collimator system30, and a homogenizing illumination system12, as shown inFIG.2.

The laser light source20B is formed, for example, of a semiconductor laser that outputs the blue light LB having a peak wavelength that falls within a range from 380 to 495 nm.

FIG.3shows the configuration of key parts of the laser light source20B. The laser light source20B has a light emission area21, as shown inFIG.3. The light emission area21has a rectangular planar shape. An orthogonal coordinate system is used in the following description. The orthogonal coordinate system has a direction X, which is the lengthwise direction of the rectangular light emission area21, a direction Y, which is the direction in which the blue light LB exits via the light emission area21, and a direction Z, which is perpendicular to the directions X and Y and is the widthwise direction of the rectangular light emission area21.

Specifically, the light emission area21has a substantially oblong planar shape having short sides extending in the direction Z and long sides extending in the direction X when viewed along the chief ray of the blue light LB outputted from the laser light source20B.

The blue light LB outputted from the laser light source20B is linearly polarized light. The angle of divergence of the blue light LB in the widthwise direction of the light emission area21is greater than the angle of divergence of the blue light LB in the lengthwise direction of the light emission area21. That is, a cross section DS extending along the plane XZ parallel to a plane perpendicular to the optical axis of the blue light LB has an elliptical shape having a minor axis extending in the direction X and a major axis extending in the direction Z.

The collimator system30parallelizes the blue light LB from the laser light source20B.

FIG.4is a perspective view showing the configuration of the collimator system30. The collimator system30is formed of three lens groups, as shown inFIG.4. Specifically, the collimator system30includes a first group31, a second group32, and a third group33. The first group31, the second group32, and the third group33are each formed of at least one lens.

In the present embodiment, the first group31, the second group32, and the third group33are each formed of one lens. The first group31includes an anamorphic lens (first anamorphic lens)34having negative power in the direction X (first direction). In the present embodiment, the anamorphic lens34is formed of a biconcave lens34ahaving a first anamorphic surface34a1and second anamorphic surface34a2on opposite sides.

The first anamorphic surface34a1and the second anamorphic surface34a2in the present embodiment are formed of cylindrical surfaces having generatrixes34B1and34B2extending in the direction Z, respectively. That is, the biconcave lens34ais formed of a first cylindrical lens having negative power in a plane parallel to the plane XY.

The first anamorphic surface34a1and the second anamorphic surface34a2increase the angle of divergence of the light emitted via the light emission area21in the direction X out of the angles of divergence of the light. That is, the first anamorphic surface34a1and the second anamorphic surface34a2allow further divergence of components of the blue light LB that are components having small angles of divergence.

In the present embodiment, the anamorphic lens34, which is formed of the biconcave lens34a,can increase the lens power by causing the blue light LB to diverge when the blue light LB is incident on the lens and when the blue light LB exits out of the lens. The blue light LB having passed through the anamorphic lens34therefore has a larger angle of divergence than that of the blue light LB having exited via the light emission area21. For example, the angle of divergence of the blue light LB in the direction X after the blue light LB passes through the anamorphic lens34is equal to the angle of divergence of the blue light LB in the widthwise direction of the light emission area21.

The blue light LB having passed through the anamorphic lens34enters the second lens group32. The second lens group32includes an anamorphic lens (second anamorphic lens)35having positive power in the direction Z (second direction) perpendicular to the direction X. In the present embodiment, the anamorphic lens35is formed of a planoconvex lens35a.The planoconvex lens35ahas a first surface (light incident surface)35a1formed of a flat surface and a second surface35a2located on the light exiting side and formed of an aspheric surface. The second surface35a2is formed of a cylindrical surface having a generatrix35B extending in the direction X (first direction) . That is, the planoconvex lens35ais formed of a second cylindrical lens having positive power in a plane parallel to the plane ZY.

The second surface35a2parallelizes the blue light LB by causing convergence of a component of the blue light LB that is the component caused to diverge in the direction Z along the widthwise direction of the light emission area21. That is, the second surface35a2parallelizes the blue light LB by causing components of the blue light LB that are components having large angles of divergence.

The blue light LB having passed through the anamorphic lens35is therefore parallelized in a plane parallel to the plane ZY, where the blue light LB has a large angle of divergence. The blue light LB is not affected by the power of the anamorphic lens35in a plane parallel to the plane XY when the blue light LB passes through the anamorphic lens35, so that the blue light LB keeps diverging in the plane parallel to the plane XY.

In the present embodiment, the anamorphic lens35, which is formed of the planoconvex lens35a,is readily manufactured as compared with a case where the anamorphic lens35has lens surfaces on opposite sides, whereby the cost of the anamorphic lens35can be reduced. The planoconvex lens35a,which has a flat surface as the first surface35a1on the light incident side on which the blue light LB is incident, and a cylindrical surface as the second surface35a2on the light exiting side, can increase the distance over which the blue light LB having entered the anamorphic lens35is parallelized. Sufficient divergence of the blue light LB is thus achieved, whereby the light flux width of the blue light LB in the direction Z can be increased.

The blue light LB having passed through the anamorphic lens35enters the third group33. The third group33includes an anamorphic lens (third anamorphic lens)36having positive power in the direction X. In the present embodiment, the anamorphic lens36is formed of a planoconvex lens36a.The planoconvex lens36ahas a first surface (light incident surface)36a1, which is a flat surface, and a second surface36a2, which is located on the light exiting side and formed of an aspheric surface. The second surface36a2is formed of a cylindrical surface having a generatrix36B extending in the direction Z (second direction). That is, the planoconvex lens36ais formed of a third cylindrical lens having positive power in a plane parallel to the plane XY.

The blue light LB has been parallelized in the plane parallel to the plane ZY but diverges in the plane parallel to the plane XY when incident on the planoconvex lens36a. Since the angle of divergence of the blue light LB in the plane parallel to the plane XY has been so increased as to be as large as the angle of divergence of the blue light LB in the widthwise direction of the light emission area21, the light flux width of blue light LB in the direction X has been increased when the blue light LB is incident on the anamorphic lens36. The second surface36a2parallelizes the blue light LB by causing convergence of the blue light LB that diverges in the plane parallel to the plane XY.

The blue light LB having passed through the anamorphic lens36is therefore parallelized also in the plane parallel to the plane XY, where the angle of divergence of the blue light LB is small.

Since the anamorphic lens36is formed of the planoconvex lens36a,the lens can be readily manufactured, whereby the cost of the anamorphic lens36can be reduced. Further, since the planoconvex lens36ahas a flat surface on the side on which the blue light LB is incident and a cylindrical surface on the light exiting side, the distance over which the blue light LB incident on the anamorphic lens36is parallelized can be increased. Sufficient divergence of the blue light LB can therefore increase the light flux width of the blue light LB in the direction X.

In the collimator system30in the present embodiment, the distance between each of the first group31, the second group32, and the third group33along the optical path of the chief ray of the blue light LB having exited via the light emission area21and the lens power of each of the first group31, the second group32, and the third group33are so set that the aspect ratio of the cross section of the blue light LB having exited via the light emission area21is substantially 1. That is, in the present embodiment, the cross section of the blue light LB outputted from the laser light source20B is converted by the collimator system30from the elliptical shape into a substantially circular shape, as shown inFIG.4.

As Comparative Example of the collimator lens30in the present embodiment, consider now a case where only two cylindrical lenses (anamorphic lenses35and36) are used to parallelize the blue light LB. In this case, the blue light LB having passed through the anamorphic lens35is parallelized in the plane parallel to the plane ZY, where the angle of divergence of the blue light LB is large, and parallelized when passing through the anamorphic lens36also in the plane parallel to the plane XY, where the angle of divergence of the blue light LB is small.

In the case where only the anamorphic lenses35and36are used to convert the cross section of the blue light LB from the elliptical shape into a substantially circular shape, it is necessary to increase the distance between the anamorphic lenses35and36along the optical axis of the chief ray of the blue light LB. The reason for this is as follows: In a case where the distance between the anamorphic lenses35and36is so set as to be equal to the length of the collimator system30in the present embodiment, the light flux width of the blue light LB in the direction X cannot be increased to be as large as the light flux width of the blue light LB in the direction Z by causing the blue light LB to sufficiently diverge in the plane parallel to the plane XY, where the angle of divergence of the blue light LB is small, before the blue light LB is incident on the anamorphic lens36, so that the cross-sectional shape of the blue light LB cannot be converted into a substantially circular shape.

In contrast, the collimator system30in the present embodiment allows the blue light LB to be incident on the anamorphic lens35, which is the second group32, with the angle of divergence of the blue light LB in the lengthwise direction of the light emission area21so increased by the anamorphic lens34, which is the first group31, as to be substantially equal to the angle of divergence of the blue light LB in the widthwise direction of the light emission area21. Therefore, after the blue light LB is parallelized by the anamorphic lens35in the plane parallel to the plane ZY, the blue light LB is allowed to sufficiently diverge before incident on the anamorphic lens36, whereby the light flux width of the blue light LB can be increased. The cross section of the blue light LB can be converted into a substantially circular shape with the distance between the anamorphic lenses35and36being smaller than that in the configuration of Comparative Example described above.

According to the collimator system30in the present embodiment, employing the three-group configuration in which the anamorphic lens34, which is the first group31, is added in the optical path of the blue light LB between the light emission area21and the anamorphic lens35allows the distance from the light emission area21to the anamorphic lens36to be reduced as compared with the distance provided by the collimator system in Comparative Example using only the anamorphic lenses35and36. The first light source apparatus2A including the collimator system30in the present embodiment can therefore convert the light flux cross-sectional shape of the blue light LB into a substantially circular shape with no increase in the size of the apparatus.

The homogenizing illumination system12includes a first lens array90, a second lens array91, and a superimposing lens92.

The first lens array90includes a plurality of first lenslets90afor dividing the blue light LB having exited out of the collimator system30into a plurality of sub-light ray fluxes. The plurality of first lenslets90aare arranged in an array in a plane perpendicular to the illumination optical axis of the first light source apparatus2A. In the present embodiment, the light incident area of the first lens array90has, for example, a substantially square shape. Since the blue light LB has been converted by the collimator system30into parallelized light having a substantially circular cross-sectional shape, the blue light LB is efficiently incident on the entire square light incident area of the first lens array90.

The second lens array91includes a plurality of second lenslets91a.The plurality of second lenslets91acorrespond to the plurality of first lenslets90a.The second lens array91along with the superimposing lens92superimposes images of the first lenslets90aof the first lens array90with one another in an area in the vicinity of an image formation area of the light modulator4B.

The first light source apparatus2A according to the present embodiment, which includes the collimator system30, can convert the cross-sectional shape of the blue light LB into a substantially circular shape with the size of the apparatus reduced. The blue light LB is thus allowed to be efficiently incident on the first lens array90. The performance of the homogenizing illumination system12, which superimposes the sub-light ray fluxes of the blue light LB with one another, can therefore be improved.

FIG.5shows a schematic configuration of the second light source apparatus2B.

The second light source apparatus2B includes a blue array light source51A, a first collimator system52, an afocal system53, a dichroic mirror55, a first light collection system56, a fluorescence emitter57, a first lens integrator61, a polarization converter62, and a superimposing lens63, as shown inFIG.5.

The blue array light source51A, the first collimator system52, the afocal system53, and the dichroic mirror55are sequentially arranged along an optical axis ax1. The optical axis ax1is the optical axis of the blue array light source51A.

On the other hand, the fluorescence emitter57, the first light collection system56, the dichroic mirror55, the first lens integrator61, the polarization converter62, and the superimposing lens63are sequentially arranged along an illumination optical axis ax2. The optical axis ax1and the illumination optical axis ax2are located in the same plane and perpendicular to each other.

The blue array light source51A includes a plurality of blue laser light emitters51a.The plurality of blue laser light emitters51aare arranged in an array in a plane perpendicular to the optical axis ax1. The blue laser light emitters51aeach emit, for example, blue excitation light BL (blue laser beam that belongs to wavelength band ranging from 440 to 470 nm, for example).

The excitation light BL outputted from the blue array light source51A enters the first collimator system52. The first collimator system52converts the excitation light BL outputted from the blue array light source51A into parallelized light. The first collimator system52is formed, for example, of a plurality of collimator lenses52aarranged in an array. The plurality of collimator lenses52aare disposed in correspondence with the plurality of blue laser light emitters51a.

The excitation light BL having passed through the first collimator system52enters the afocal system53. The afocal system53adjusts the light flux diameter of the excitation light BL. The afocal system53is formed, for example, of a convex lens53aand a concave lens53b.

The excitation light BL having passed through the afocal system53is incident on the dichroic mirror55. The dichroic mirror55is so disposed as to incline by 45° with respect to the optical axis ax1and the illumination optical axis ax2. The dichroic mirror55reflects the excitation light BL toward the fluorescence emitter57and transmits the fluorescence YL, which belongs to a wavelength band different from the wavelength band to which the excitation light BL belongs.

Specifically, the dichroic mirror55reflects the excitation light BL to cause the reflected excitation light BL to enter the first light collection system56. The first light collection system56collects the excitation light BL and directs the collected excitation light BL toward a phosphor64of the fluorescence emitter57.

In the present embodiment, the first light collection system56is formed, for example, of a first lens56aand a second lens56b.The collected excitation light BL having exited out of the first light collection system56is incident on the fluorescence emitter57. The fluorescence emitter57includes the phosphor64, a substrate65, which supports the phosphor64, and a fixing member66, which fixes the phosphor64to the substrate65.

In the present embodiment, the phosphor64is fixed to the substrate65via the fixing member66provided between the side surface of the phosphor64and the substrate65. The phosphor64is in contact with the substrate65on a surface of the phosphor64that is the surface opposite the side on which the excitation light BL is incident.

The phosphor64contains phosphor particles that absorb the excitation light BL and are excited thereby. The phosphor particles excited with the excitation light BL emit the fluorescence (yellow fluorescence) YL, which belongs to a wavelength band ranging, for example, from 500 to 700 nm.

A reflector67is provided on a side of the phosphor64that is the side opposite the side on which the excitation light BL is incident (side opposite first light collection system56). The reflector67reflects components of the fluorescence YL produced by the phosphor64that are the components traveling toward the substrate65.

A heat sink68is disposed on a surface of the substrate65that is the surface opposite the surface that supports the phosphor64. The heat in the fluorescence emitter57can be dissipated via the heat sink68, whereby degradation of the phosphor64due to the heat can be avoided.

Part of the fluorescence YL produced by the phosphor64is reflected off the reflector67and exits out of the phosphor64. The remainder of the fluorescence YL produced by the phosphor64exits out of the phosphor64via no reflector67. The fluorescence YL thus exits out of the phosphor64.

The fluorescence YL emitted from the phosphor64is non-polarized light. The fluorescence YL passes through the first light collection system56and is incident on the dichroic mirror55. The fluorescence YL then passes through the dichroic mirror55and travels toward the first lens integrator61.

The fluorescence YL exits toward the first lens integrator61. The first lens integrator61includes a first multi-lens61aand a second multi-lens61b.The first multi-lens61aincludes a plurality of first lenslets61amfor dividing the fluorescence YL into a plurality of sub-light ray fluxes.

The lens surface of the first multi-lens61a(surface of each of first lenslets61am) is conjugate with the image formation area of each of the light modulators4R and4G. The shape of each of the first lenslets61amis therefore substantially similar to the shape of the image formation area of each of the light modulators4R and4G (rectangular shape). The sub-light ray fluxes having exited out of the first multi-lens61aare therefore efficiently incident on the image formation area of each of the light modulators4R and4G.

The second multi-lens61bincludes a plurality of second lenslets61bmcorresponding to the first lenslets61amof the first multi-lens61a.The second multi-lens61balong with the superimposing lens63forms images of the first lenslets61amof the first multi-lens61ain an area in the vicinity of the image formation area of each of the light modulators4R and4G.

The fluorescence YL having passed through the first lens integrator61enters the polarization converter62. The polarization converter62is formed of polarization separation films and retardation films (half wave plates) arranged in an array. The polarization converter62converts the non-polarized fluorescence YL into linearly polarized light and causes the linearly polarized light to exit.

More specifically, the polarization converter62is so disposed as to correspond to the direction of the transmission axis of the polarizers (not shown) disposed on the light incident side of the light modulators4R and4G. The polarization directions of the red light LR and the green light LG provided from the separation of the fluorescence YL therefore correspond to the direction of the transmission axis of the polarizers on the light incident side of the light modulators4R and4G. Therefore, the red light LR or the green light LG is not blocked by the corresponding light-incident-side polarizer, but the red light LR and the green light LG are satisfactorily guided to the image formation areas of the light modulators4R and4G.

The fluorescence YL having passed through the polarization converter62enters the superimposing lens63. The superimposing lens63cooperates with the first lens integrator61to homogenize the illuminance distribution of the fluorescence YL in each illumination receiving area.

As described above, the projector1according to the present embodiment, which includes the first light source apparatus2A capable of converting the cross-sectional shape of the blue light LB into a substantially circular shape, can display a good-quality image by causing the blue light LB to be efficiently incident on the light modulator4B. Further, since the size of the first light source apparatus2A can be reduced, the size of the projector1itself can be reduced.

Second Embodiment

A projector according to a second embodiment will be subsequently described. The configurations and members common to those in the first embodiment have the same reference characters and will not be described in detail.

FIG.6is a schematic configuration diagram of the projector according to the present embodiment.

A projector101includes a light source apparatus102R for red light, a light source apparatus102G for green light, a light source apparatus102B for blue light, the light modulators4R,4G, and4B, the field lenses10R,10G, and10B, the light combining system5, total reflection mirrors18R,18G, and18B, as shown inFIG.6.

In the present embodiment, the light source apparatus102B for blue light is formed of the light source apparatus2A according to the first embodiment. The light source apparatus102B for blue light can therefore convert the light flux cross-sectional shape of the blue light LB1into a substantially circular shape with no increase in the size of the apparatus. The blue light LB1outputted from the light source apparatus102B for blue light is so totally reflected off the total reflection mirror18B as to be incident on the light modulator4B.

The light source apparatus102G for green light and the light source apparatus102R for red light differ from the light source apparatus102B for blue light only in terms of the color of the outputted light (wavelength region) and are the same as the light source apparatus102B for blue light in terms of the apparatus configuration. The green light LG outputted from the light source apparatus102G for green light is so totally reflected off the total reflection mirror18G as to be incident on the light modulator4G. The red light LR outputted from the light source apparatus102R for red light is so totally reflected off the total reflection mirror18R as to be incident on the light modulator4R.

The light source apparatus102G for green light includes a laser light source20G, a collimator system30G, and the homogenizing illumination system12. The laser light source20G is formed, for example, of a semiconductor laser that outputs green light LG1having a peak wavelength that falls within a range from 495 to 585 nm. The light emission area of the laser light source20G has a rectangular planar shape. Across section of the green light LG1that is the cross section parallel to a plane perpendicular to the optical axis of the green light LG1has an elliptical shape having a minor axis extending in the direction X and a major axis extending in the direction Z.

The collimator system30G has the same configuration as that of the collimator system30shown inFIG.4and parallelizes the green light LG1from the laser light source20G. In the present embodiment, the cross-sectional shape of the green light LG1outputted from the laser light source20G is therefore converted by the collimator system30G from the elliptical shape into a substantially circular shape (seeFIG.4).

The light source apparatus102R for red light includes a laser light source20R, a collimator system30R, and the homogenizing illumination system12. The laser light source20R is formed, for example, of a semiconductor laser that outputs red light LR1having a peak wavelength that falls within a range from 585 to 720 nm. The light emission area of the laser light source20R has a rectangular planar shape. A cross section of the red light LR1that is the cross section parallel to a plane perpendicular to the optical axis of the red light LR1has an elliptical shape having a minor axis extending in the direction X and a major axis extending in the direction Z.

The collimator system30R has the same configuration as that of the collimator system30shown inFIG.4and parallelizes the red light LR1from the laser light source20R. In the present embodiment, the cross-sectional shape of the red light LR1outputted from the laser light source20R is therefore converted by the collimator system30R from the elliptical shape into a substantially circular shape (seeFIG.4).

The light source apparatus102G for green light, which includes the collimator system30G in the present embodiment, can therefore convert the light flux cross-sectional shape of the green light LG1into a substantially circular shape with no increase in the size of the apparatus. The light source apparatus102R for red light, which includes the collimator system30R in the present embodiment, can similarly convert the light flux cross-sectional shape of the red light LR1into a substantially circular shape with no increase in the size of the apparatus.

The light source apparatus102R for red light, the light source apparatus102G for green light, and the light source apparatus102B for blue light according to the present embodiment allow the red light LR1, the green light LG1, and the blue light LB1to be efficiently incident on the respective homogenizing illumination systems12. The performance of the homogenizing illumination systems12, which superimpose the sub-light ray fluxes of the red light LR1, the green light LG1, and the blue light LB1with one another on the light modulators4R,4G and4B, can therefore be improved.

As described above, the projector101according to the present embodiment can display a good-quality image by causing the red light LR1, the green light LG1, and the blue light LB1to be efficiently incident on the light modulators4R,4G, and4B. Further, since the sizes of the light source apparatus102R for red light, the light source apparatus102G for green light, and the light source apparatus102B for blue light can be reduced, the size of the projector101itself can be reduced.

Further, the projector101according to the present embodiment, in which the red light LR1outputted from the light source apparatus102R for red light, the green light LG1outputted from the light source apparatus102G for green light, and the blue light LB1outputted from the light source apparatus102B for blue light are so reflected off the total reflection mirrors18R,18G, and18B as to be incident on the light modulators4R,4G, and4B, whereby the light source apparatus102R for red light, the light source apparatus102G for green light, and the light source apparatus102B for blue light can be so disposed as to surround the circumference of the projection optical apparatus6. The space around the projection optical apparatus6can thus be effectively used to dispose the light source apparatuses. The size of the projector101can therefore be reduced as compared with a case where the total reflection mirrors18R,18G, and18B are not used.

The present disclosure is not limited to the contents of the embodiments described above and can be changed as appropriate to the extent that the change does not depart from the substance of the present disclosure.

In the embodiments described above, the first group31, the second group32, and the third group33, which form each of the collimator systems30,30R,30G, and30B, are each formed of one lens, and at least any of the first group31, the second group32, and the third group33may be formed of a plurality of lenses. Further, the above embodiments have been described with reference to the case where the second surfaces35a2and36a2of the planoconvex lenses35aand36a, which form the anamorphic lenses35and36, are each an aspheric surface, and the second surfaces35a2and36a2may each be a spherical surface.