JP6835059B2 - Light source device and projector - Google Patents

Description

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

As a light source device used in a projector, a light source device using fluorescence emitted from a phosphor when the phosphor is irradiated with excitation light emitted from a light emitting element has been proposed. The following Patent Document 1 includes a flat plate-shaped wavelength conversion member containing a phosphor and a light emitting diode (LED) that emits excitation light, from a surface having a large area among a plurality of surfaces of the wavelength conversion member. A light source device for incidenting excitation light and emitting the converted light from a surface having a narrow area of a wavelength conversion member is disclosed.

International Publication No. 2006-054203

As described in Patent Document 1, by incidenting the excitation light from the LED into the wavelength conversion member, it is possible to obtain light having a wavelength different from the wavelength of the light emitted from the LED. For example, when the wavelength conversion member contains a yellow phosphor, yellow light can be obtained from the blue excitation light emitted from the LED. In order to obtain bright light in this configuration, it is necessary to take measures such as increasing the power of the excitation light source or increasing the wavelength conversion member and increasing the number of excitation light sources. However, when the power of the excitation light source is increased, the amount of heat generated from the excitation light source increases, and there is a problem that the light source device including the cooling system becomes large. Further, when the number of excitation light sources is increased, there is a problem that the ratio of the light incident on the wavelength conversion member to the total emitted light from the excitation light sources decreases.

In order to solve the above problems, the light source device of one aspect of the present invention includes a light source that emits excitation light and a first phosphor, and the excitation light is different from the wavelength band of the excitation light. A second fluorescence that includes a first wavelength conversion unit that converts to the first fluorescence having one wavelength band and a second phosphor, and has a second wavelength band different from the wavelength band of the excitation light. It is provided with a second wavelength conversion unit that converts the light into, and a light guide unit that guides the second fluorescence emitted from the second wavelength conversion unit to the first wavelength conversion unit. The first wavelength conversion unit has a first end face and a second end face facing each other, and a first side surface intersecting the first end face and the second end face. The second wavelength conversion unit has a third end face and a fourth end face facing each other, and a second side surface intersecting the third end face and the fourth end face. The first side surface of the first wavelength conversion unit and the second side surface of the second wavelength conversion unit face each other, and the light guide unit is the third end surface of the second wavelength conversion unit and the second surface. It has a reflecting surface facing the second end surface of the one wavelength conversion unit, and the first fluorescence and the second fluorescence are emitted from the first end surface of the first wavelength conversion unit.

The light source device of one aspect of the present invention is provided on the fourth end surface of the second wavelength conversion unit, and includes a reflection unit that reflects the second fluorescence that guides the inside of the second wavelength conversion unit. You may be.

In the light source device of one aspect of the present invention, the reflecting surface of the light guide unit is the first reflecting surface facing the third end surface of the second wavelength conversion unit and the second reflecting surface of the first wavelength conversion unit. The second fluorescent surface having a second reflecting surface facing the end face and emitted inside the second wavelength conversion unit is emitted from the third end face and reflected by the first reflecting surface. It may be reflected by the second reflecting surface, incident on the first wavelength conversion unit from the second end surface, and emitted from the first end surface.

In the light source device according to one aspect of the present invention, the light guide portion includes a first prism having the first reflecting surface, a second prism having the second reflecting surface, the first prism, and the second prism. A glass block provided between the two may be provided.

The light source device of one aspect of the present invention is a third wavelength conversion unit that includes a third phosphor and emits a third wavelength having a third wavelength band different from the first wavelength band and the second wavelength band. The third wavelength conversion unit may further include a fifth end face and a sixth end face facing each other, and a fifth side surface intersecting the fifth end face and the sixth end face. The first side surface of the first wavelength conversion unit and the fifth side surface of the third wavelength conversion unit face each other, and the second side surface of the second wavelength conversion unit and the third side surface of the third wavelength conversion unit face each other. The five side surfaces are opposed to each other, and the light guide portion is a first light guide portion having a first reflection surface and a third reflection surface facing the sixth end surface of the third wavelength conversion unit. , The second light guide portion having the second reflecting surface and the fourth reflecting surface facing the fifth end surface of the third wavelength conversion unit may be provided.

In the light source device of one aspect of the present invention, the light source may include a first light emitting element that emits a first excitation light and a second light emitting element that emits a second excitation light.

In the light source device of one aspect of the present invention, the first wavelength conversion unit has a third side surface that intersects the first end surface and the second end surface, and the second wavelength conversion unit has the third end surface. And may have a fourth side surface intersecting with the fourth end surface, the first excitation light is incident on the first wavelength conversion part from the third side surface of the first wavelength conversion part, and said. The second excitation light may be incident on the second wavelength conversion unit from the fourth side surface of the second wavelength conversion unit.

In the light source device of one aspect of the present invention, the light source is provided so as to face the third side surface of the first wavelength conversion unit and the fourth side surface of the second wavelength conversion unit, and the first excitation is performed. It may have a light emitting diode that emits light and the second excitation light.

In the light source device of one aspect of the present invention, the wavelength band of the first excitation light and the wavelength band of the second excitation light may be different.

In the light source device of one aspect of the present invention, the first wavelength band and the second wavelength band may be the same wavelength band.

In the light source device of one aspect of the present invention, the first wavelength band and the second wavelength band may be different wavelength bands.

In the light source device of one aspect of the present invention, the first wavelength band may be a blue wavelength band and the second wavelength band may be a yellow wavelength band.

In the light source device of one aspect of the present invention, the first wavelength band may be a green wavelength band and the second wavelength band may be a red wavelength band.

In the light source device of one aspect of the present invention, the first wavelength band may be a blue wavelength band, the second wavelength band may be a red wavelength band, and the third wavelength band may be a green wavelength band.

The light source device according to one aspect of the present invention is provided on the light emitting side of the first wavelength conversion unit, has a light incident end face and a light emitting end face, and sets the diffusion angle at the light emitting end face at the light incident end face. An angle conversion element that is smaller than the diffusion angle may be further provided.

The projector according to one aspect of the present invention comprises a light source device according to one aspect of the present invention, an optical modulator that modulates light from the light source device according to image information, and light modulated by the optical modulator. A projection optical device for projecting is provided.

It is a schematic block diagram of the projector of 1st Embodiment. It is a schematic block diagram of the light source apparatus of 1st Embodiment. It is sectional drawing of the light source apparatus along the line III-III of FIG. It is a schematic block diagram of the light source apparatus of 2nd Embodiment. It is a schematic block diagram of the projector of 3rd Embodiment. It is a schematic block diagram of the light source apparatus of 3rd Embodiment. It is a schematic block diagram of the light source apparatus of 4th Embodiment. It is a schematic block diagram of the light guide part of the 1st modification. It is a figure for demonstrating the problem of the light guide part of 1st Embodiment. It is a schematic block diagram of the light guide part of the 2nd modification.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 3.
The projector of this embodiment is an example of a projector using a liquid crystal panel as an optical modulation device.
In each of the drawings below, in order to make each component easy to see, the scale of the dimensions may be different depending on the component.

FIG. 1 is a schematic configuration diagram of the projector 1 of the first embodiment.
The projector 1 of the first embodiment is a projection type image display device that projects a color image on a screen (projected 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.

As shown in FIG. 1, the projector 1 includes an illumination device 12, a uniform illumination optical system 40, a color separation optical system 3, an optical modulator 4R, an optical modulator 4G, an optical modulator 4B, and synthetic optics. The system 5 and the projection optical device 6 are provided.

The illuminating device 12 emits white illumination light WL toward the uniform illumination optical system 40. The detailed configuration of the lighting device 12 will be described in detail later.

The uniform illumination optical system 40 includes an integrator optical system 31, a polarization conversion element 32, and a superimposition optical system 33. The integrator optical system 31 includes a first lens array 31a and a second lens array 31b. The uniform illumination optical system 40 equalizes the intensity distribution of the illumination light WL emitted from the light source device 2 in each of the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, which are the illuminated areas. The illumination light WL emitted from the uniform illumination optical system 40 is incident on the color separation optical system 3.

The color separation optical system 3 separates the white illumination light WL into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a, a second dichroic mirror 7b, a first reflection mirror 8a, a second reflection mirror 8b, a third reflection mirror 8c, a first relay lens 9a, and a first. It is equipped with a two-relay lens 9b.

The first dichroic mirror 7a separates the illumination light WL from the illumination device 12 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 separates 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 reflection mirror 8a is arranged 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 reflection mirror 8b and the third reflection mirror 8c are arranged in the optical path of the blue light LB, and reflect the blue light LB transmitted through the second dichroic mirror 7b toward the light modulator 4B. Further, the green light LG is reflected toward the optical 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 emitting 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 correct the difference in the illumination distribution of the blue light LB caused by the optical path length of the blue light LB being longer than the optical path length of the red light LR and the green light LG.

The light modulation device 4R modulates the red light LR according to the image information to form the image light corresponding to the red light LR. The optical modulation device 4G modulates the green light LG according to the image information to form the image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to the image information to form the image light corresponding to the blue light LB.

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

A field lens 10R, a field lens 10G, and a field lens 10B are arranged 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 parallelize the main rays of the red light LR, the green light LG, and the blue light LB incident on the respective optical modulator 4R, optical modulator 4G, and optical modulator 4B. To do.

The synthetic optical system 5 emits image light corresponding to red light LR, green light LG, and blue light LB by incident image light emitted from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. It is synthesized and the combined image light is emitted toward the projection optical device 6. For the synthetic optical system 5, for example, a cross dichroic prism is used.

The projection optical device 6 is composed of a plurality of projection lenses. The projection optical device 6 magnifies and projects the image light synthesized by the synthetic optical system 5 toward the screen SCR. As a result, the image is displayed on the screen SCR.

Hereinafter, the lighting device 12 will be described.
The lighting device 12 includes a light source device 2, a blue light source unit 13, and a photosynthetic element 14.

FIG. 2 is a schematic configuration diagram of the light source device 2.
FIG. 3 is a cross-sectional view of the light source device along the line III-III of FIG.
As shown in FIGS. 2 and 3, the light source device 2 includes a first wavelength conversion rod 51 (first wavelength conversion unit), a second wavelength conversion rod 52 (second wavelength conversion unit), a light source 35, and a mirror. It includes 54 (reflecting unit), a prism mirror 55 (light source unit), an angle conversion element 56, and a collimator lens 57.

The first wavelength conversion rod 51 has a square columnar shape, and has four side surfaces 51c1, 51c2, 51c3 that intersect the first end face 51a and the second end face 51b facing each other and the first end face 51a and the second end face 51b. , 51c4 and. The entire four sides 51c1, 51c2, 51c3, 51c4 correspond to the first side of the claims. In the first wavelength conversion rod 51, the fluorescence KY is emitted from the first end surface 51a. The axis passing through the center of the first end surface 51a and the center of the second end surface 51b of the first wavelength conversion rod 51 is defined as the optical axis J1 of the light source device 2. The fluorescence KY emitted inside the light source device 2 is emitted from the first end surface 51a in the direction of the optical axis J1.

The second wavelength conversion rod 52 has a square columnar shape, and has four side surfaces 52c1, 52c2, 52c3 that intersect the third end face 52a and the fourth end face 52b facing each other and the third end face 52a and the fourth end face 52b. , 52c4 and. The entire four sides 52c1, 52c2, 52c3, 52c4 correspond to the second side of the claims. In the second wavelength conversion rod 52, the second fluorescence KY2 is emitted from the third end surface 52a.

In the present embodiment, the first wavelength conversion rod 51 and the second wavelength conversion rod 52 have substantially the same dimensions. The dimension A in the longitudinal direction of the first wavelength conversion rod 51 (normal direction of the first end surface 51a) is longer than the dimension B in the width direction of the first wavelength conversion rod 51 (normal direction of the side surface 51c2). For example, the dimension A is about 10 times to several tens of times the dimension B. The second wavelength conversion rod 52 is the same as the first wavelength conversion rod 51.

The wavelength conversion rods 51 and 52 do not necessarily have a square prism shape, and may be another polygonal prism such as a triangular prism. Alternatively, the wavelength conversion rods 51 and 52 may be columnar. When each wavelength conversion rod 51, 52 is cylindrical, each wavelength conversion rod 51, 52 has two circular end faces facing each other and one cylindrical side surface intersecting the two end faces.

The first wavelength conversion rod 51 and the second wavelength conversion rod 52 are arranged at intervals so that the side surface 51c1 of the first wavelength conversion rod 51 and the side surface 52c1 of the second wavelength conversion rod 52 face each other. .. The side surface 51c2 of the first wavelength conversion rod 51 and the side surface 52c2 of the second wavelength conversion rod 52 face opposite to each other. That is, the two wavelength conversion rods 51 and 52 are arranged in parallel.

Further, the first end surface 51a (light emission end surface) of the first wavelength conversion rod 51 and the fourth end surface 52b of the second wavelength conversion rod 52 are arranged at one end in the longitudinal direction of the wavelength conversion rods 51 and 52. There is. The second end surface 51b of the first wavelength conversion rod 51 and the third end surface 52a (light emission end surface) of the second wavelength conversion rod 52 are arranged at the other ends of the wavelength conversion rods 51 and 52 in the longitudinal direction. ..

As shown in FIG. 3, the light source 35 includes a first light source 351 and a second light source 352. The first light source 351 is provided at a position facing the side surface 51c3 of the first wavelength conversion rod 51 and the side surface 52c3 of the second wavelength conversion rod 52. The second light source 352 is provided at a position facing the side surface 51c4 of the first wavelength conversion rod 51 and the side surface 52c4 of the second wavelength conversion rod 52. The light source 35 emits the first excitation light E1 and the second excitation light E2. Of the four sides of the first wavelength conversion rod 51, the sides 51c3 and 51c4 facing the first light source 351 and the second light source 352 and incident with the first excitation light correspond to the third side of the claims. To do. Of the four sides of the second wavelength conversion rod 52, the sides 52c3 and 52c4 facing the first light source 351 and the second light source 352 and incident with the second excitation light correspond to the fourth side of the claims. To do.

The first light source 351 and the second light source 352 have the same configuration, and a plurality of light emitting diodes 61 (LEDs) mounted on one surface of the substrate 353 and the substrate 353 facing each of the wavelength conversion rods 51 and 52. ) And. In the present embodiment, each of the light sources 351 and 352 includes six LEDs 61, but the number of LEDs 61 is not particularly limited. The LED 61 emits a first excitation light E1 and a second excitation light E2. The wavelength band of the first excitation light E1 and the second excitation light E2 is, for example, an ultraviolet wavelength band of 200 nm to 380 nm. However, the wavelength band of the excitation light may be, for example, a purple wavelength band or a blue wavelength band of around 400 nm. In addition to the substrate 353 and the LED 61, each light source 351 and 352 may have other optical members such as a light guide plate, a diffuser plate, and a lens.

Each of the plurality of LEDs 61 is provided at a position facing both the first wavelength conversion rod 51 and the second wavelength conversion rod 52. That is, each LED 61 is arranged so as to straddle the first wavelength conversion rod 51 and the second wavelength conversion rod 52, and the light source for excitation light of the first wavelength conversion rod 51 and the second wavelength conversion rod 52. It also serves as a light source for excitation light. Therefore, the excitation light of the same wavelength band is incident on the first wavelength conversion rod 51 and the second wavelength conversion rod 52. Of the excitation light emitted from the LED 61, the excitation light incident on the first wavelength conversion rod 51 corresponds to the first excitation light, and the excitation light incident on the second wavelength conversion rod 52 corresponds to the second excitation light. To do. The first excitation light E1 is incident on the first wavelength conversion rod 51 from the side surfaces 51c3 and 51c4 of the first wavelength conversion rod 51, and the second excitation light E2 is incident on the side surfaces 52c3 and 52c4 of the second wavelength conversion rod 52. It is incident on the second wavelength conversion rod 52.

The light source 35 may individually include an LED provided at a position facing the first wavelength conversion rod 51 and an LED provided at a position facing the second wavelength conversion rod 52. In that case, the wavelength band of the first excitation light incident on the first wavelength conversion rod 51 and the wavelength band of the second excitation light incident on the second wavelength conversion rod 52 may be different from each other.

The first wavelength conversion rod 51 includes a ceramic phosphor (first phosphor) that converts the wavelength of the first excitation light E1 into the first fluorescence KY1 having the first wavelength band. The first wavelength band is, for example, a yellow wavelength band of 490 to 750 nm. The first fluorescent KY1 is emitted from the first end surface 51a of the first wavelength conversion rod 51.

The second wavelength conversion rod 52 includes a ceramic phosphor (second phosphor) that converts the second excitation light E2 into a second fluorescence KY2 having a second wavelength band. The second wavelength band is, for example, a yellow wavelength band of 490 to 750 nm. The second fluorescence KY2 is emitted from the third end surface 52a of the second wavelength conversion rod 52. Therefore, the first fluorescence KY1 and the second fluorescence KY2 are yellow light, and the color of the first fluorescence KY1 and the color of the second fluorescence KY2 are the same.

The wavelength conversion rods 51 and 52 may be composed of a single crystal phosphor instead of the ceramic phosphor (polycrystalline phosphor). Alternatively, the wavelength conversion rods 51 and 52 may be made of fluorescent glass. Alternatively, the wavelength conversion rods 51 and 52 may be made of a material in which a large number of phosphor particles are dispersed in a binder made of glass or resin.

Each wavelength conversion rod 51, 52 contains, for example, an yttrium aluminum garnet (YAG) -based phosphor as a yellow phosphor. YAG containing cerium as an activator (Ce): Taking Ce example, as a material for the yellow _phosphor, a mixture of raw material powder containing _{Y 2 O 3, Al 2 O} 3, constituent elements of CeO _3, etc. Y-Al-O amorphous particles obtained by a wet method such as a co-precipitation method or a sol-gel method, YAG obtained by a gas phase method such as a spray drying method, a flame thermal decomposition method, or a thermal plasma method Particles and the like can be used. It is desirable that the types of phosphors contained in the wavelength conversion rods 51 and 52 are the same, but they may be different.

The mirror 54 is provided on the fourth end surface 52b of the second wavelength conversion rod 52. The mirror 54 reflects the second fluorescent KY2 that guides the inside of the second wavelength conversion rod 52. The mirror 54 is composed of a metal film or a dielectric multilayer film provided on the fourth end surface 52b of the second wavelength conversion rod 52.

The prism mirror 55 has a reflecting surface 55f provided so as to face the third end surface 52a of the second wavelength conversion rod 52 and the second end surface 51b of the first wavelength conversion rod 51. The prism mirror 55 is composed of a triangular columnar prism having a cross section of a right-angled isosceles triangle. The prism mirror 55 has a light input / output end surface 55ab, a first reflection surface 55f1, and a second reflection surface 55f2. That is, the reflecting surface 55f is composed of a first reflecting surface 55f1 and a second reflecting surface 55f2. The first reflecting surface 55f1 faces the third end surface 52a of the second wavelength conversion rod 52, and the second reflecting surface 55f2 faces the second end surface 51b of the first wavelength conversion rod 51. The triangular columnar prism may be a prism in which a first prism having a first reflecting surface 55f1 and a second prism having a second reflecting surface 55f2 are bonded together, or has a first reflecting surface 55f1 and a second reflecting surface 55f2. It may be an integral prism.

The prism mirror 55 has a function of bending the optical path of the incident second fluorescence KY2 by 180 ° and ejecting it. That is, the prism mirror 55 bends the optical path by 180 ° by sequentially reflecting the second fluorescent KY2 incident from the light input / output end surface 55ab on the two reflection surfaces 55f1 and 55f2, and emits light from the light input / output end surface 55ab. As a result, the prism mirror 55 guides the second fluorescence KY2 emitted from the second wavelength conversion rod 52 to the first wavelength conversion rod 51.

The angle conversion element 56 is provided on the first end surface 51a of the first wavelength conversion rod 51. The angle conversion element 56 is composed of a taper rod having a light incident end surface 56a on which the fluorescence KY including the first fluorescence KY1 and the second fluorescence KY2 is incident, and a light emission end surface 56b emitted by the fluorescence KY. There is. The angle conversion element 56 has a quadrangular pyramid-shaped shape, the cross-sectional area perpendicular to the optical axis J1 extends along the traveling direction of the fluorescent KY, and the area of the light emitting end surface 56b is the area of the light incident end surface 56a. Greater than. As a result, the fluorescence KY changes its angle in the direction parallel to the optical axis J1 each time it is totally reflected by the side surface 56c while traveling inside the angle conversion element 56. In this way, the angle conversion element 56 makes the diffusion angle of the fluorescence KY on the light emitting end surface 56b smaller than the diffusion angle of the fluorescence KY on the light incident end surface 56a.

The angle conversion element 56 is fixed to the first wavelength conversion rod 51 so that the light incident end surface 56a faces the first end surface 51a of the first wavelength conversion rod 51. That is, the angle conversion element 56 and the first wavelength conversion rod 51 are in contact with each other via an optical adhesive (not shown), and a gap (air layer) is provided between the angle conversion element 56 and the first wavelength conversion rod 51. Is not provided.

The angle conversion element 56 may be fixed so as to be in direct contact with the first wavelength conversion rod 51 by, for example, an arbitrary support member. In any case, it is desirable that no gap is provided between the angle conversion element 56 and the first wavelength conversion rod 51. Further, it is desirable that the refractive index of the angle conversion element 56 and the refractive index of the first wavelength conversion rod 51 match as much as possible.

Further, as the angle conversion element 56, a compound parabolic concentrator (CPC) may be used instead of the taper rod. When CPC is used as the angle conversion element 56, the same effect as when the taper rod is used can be obtained.

The collimator lens 57 is provided on the light emitting side of the light emitting end surface 56b of the angle conversion element 56. The collimator lens 57 parallelizes the fluorescence KY emitted from the angle conversion element 56. That is, the parallelism of the fluorescence KY whose angle distribution is converted by the angle conversion element 56 is further enhanced by the collimator lens 57. The collimator lens 57 is composed of a convex lens. When sufficient parallelism is obtained only by the angle conversion element 56, the collimator lens 57 does not necessarily have to be provided.

As shown in FIG. 1, the blue light source unit 13 includes a semiconductor laser 15, a diffuser plate 16, and a condenser lens 17. The axis orthogonal to the optical axis J1 of the light source device 2 and passing through the center of the photosynthetic element 14 is defined as the optical axis J2 of the blue light source unit 13. The semiconductor laser 15, the diffuser plate 16, and the condenser lens 17 are arranged in this order on the optical axis J2 from the far side to the near side to the photosynthetic element 14.

The semiconductor laser 15 emits blue light B having a predetermined wavelength band toward the diffuser plate 16. The wavelength band of blue light is, for example, 440 nm to 480 nm. As the semiconductor laser, for example, one in which a plurality of semiconductor lasers are arranged in an array may be used.

The diffuser plate 16 is provided on the light emitting side of the semiconductor laser 15. The diffuser plate 16 diffuses the blue light B emitted from the semiconductor laser 15. The diffuser plate 16 is composed of, for example, a microlens array, a holographic diffuser, frosted glass having an uneven surface, and a fly-eye lens composed of two microlens arrays. The diffusion angle distribution of the blue light B after passing through the diffuser plate 16 is wider than the diffusion angle distribution of the blue light B before passing through the diffuser plate 16. As a result, the diffusion angle of the blue light B can be widened to the same level as the diffusion angle of the fluorescence KY. As a result, it is possible to suppress color unevenness of the illumination light WL caused by the difference between the diffusion angle of the blue light B and the diffusion angle of the yellow fluorescence KY. Further, by using the diffuser plate 16, speckles that are likely to be generated by laser light can be suppressed.

The diffuser plate 16 may be configured to be rotatable about a rotation axis intersecting the plate surface of the diffuser plate 16. As a result, speckle can be effectively suppressed.

The condenser lens 17 is provided on the light emitting side of the diffuser plate 16. The condensing lens 17 condenses the blue light B emitted from the diffusing plate 16 toward the photosynthetic element 14. The condenser lens 17 is composed of a convex lens.

The photosynthetic element 14 is provided on the light emitting side of the light source device 2 and the blue light source unit 13. The photosynthetic element 14 is composed of a dichroic mirror. The dichroic mirror transmits the yellow fluorescent KY emitted from the light source device 2 and reflects the blue light B emitted from the blue light source unit 13. As a result, the photosynthetic element 14 generates a white illumination light WL in which the yellow fluorescent KY and the blue light B are combined.

Hereinafter, the behavior of light in the light source device 2 of the present embodiment will be described.
When the second excitation light E2 emitted from the LED 61 is incident on the second wavelength conversion rod 52, the second phosphor contained in the second wavelength conversion rod 52 is excited, and the second fluorescence KY2 is excited from an arbitrary light emitting point P2. Is emitted. The second fluorescence KY2 travels in all directions from the arbitrary emission point P2, while the second fluorescence KY2 toward the sides 52c1, 52c2, 52c3, 52c4 is at the sides 52c1, 52c2, 52c3, 52c4. While repeating total reflection, the process proceeds toward the third end surface 52a or the fourth end surface 52b. The second fluorescence KY2 toward the third end surface 52a is incident on the prism mirror 55. On the other hand, the second fluorescent KY2 toward the fourth end surface 52b is reflected by the mirror 54 and proceeds toward the third end surface 52a.

The second fluorescent KY2 incident on the prism mirror 55 is sequentially reflected by the first reflecting surface 55f1 and the second reflecting surface 55f2 of the prism mirror 55, so that the optical path is folded back and the second end surface 51b to the first wavelength conversion rod 51. Incident in.

On the other hand, when the first excitation light E1 emitted from the LED 61 is incident on the first wavelength conversion rod 51, the first phosphor contained in the first wavelength conversion rod 51 is excited and the first emission point P1 to the first. Fluorescent KY1 is emitted. The first fluorescence KY1 travels in all directions from the arbitrary light emitting point P1, but the first fluorescence KY1 toward the side surfaces 51c1, 51c2, 51c3, 51c4 is on the side surfaces 51c1, 51c2, 51c3, 51c4. While repeating total reflection, the process proceeds toward the first end surface 51a or the second end surface 51b. The first fluorescence KY1 toward the first end surface 51a is incident on the angle conversion element 56. The first fluorescence KY1 heading toward the second end surface 51b follows a path opposite to that of the second fluorescence KY2, enters the second wavelength conversion rod 52, is reflected by the mirror 54 of the fourth end surface 52b, and is a prism. It re-enters the first wavelength conversion rod 51 via the mirror 55.

The second fluorescence KY2 incident on the first wavelength conversion rod 51 guides the inside of the first wavelength conversion rod 51 together with the first fluorescence KY1 and is a fluorescence composed of the first fluorescence KY1 and the second fluorescence KY2. KY is ejected from the first end surface 51a of the first wavelength conversion rod 51. That is, focusing on the second fluorescence KY2, the second fluorescence KY2 emitted inside the second wavelength conversion rod 52 is emitted from the third end surface 52a, reflected by the first reflection surface 55f1, and the second reflection. It is reflected by the surface 55f2, is incident on the first wavelength conversion rod 51 from the second end surface 51b, and is ejected from the first end surface 51a. The fluorescence KY emitted from the first wavelength conversion rod 51 is parallelized by the angle conversion element 56 and the collimator lens 57, and then emitted from the light source device 2. The fluorescent KY (illumination light WL) emitted from the light source device 2 advances toward the integrator optical system 31 as shown in FIG.

In the light source device 2 of the present embodiment, the side surfaces 51c1 and 52c1 face each other so that the first wavelength conversion rod 51 that emits the first fluorescence KY1 and the second wavelength conversion rod 52 that emits the second fluorescence KY2 face each other. It is located in. Further, the first light source 351 and the second light source 352 are provided at positions facing the side surfaces 51c3 and 51c4 of the first wavelength conversion rod 51 and the side surfaces 52c3 and 52c4 of the second wavelength conversion rod 52. As a result, a small light source device 2 can be realized.

In particular, in the case of the present embodiment, since the two wavelength conversion rods 51 and 52 that emit the fluorescent KY1 and KY2 are arranged so that the side surfaces face each other, the two wavelength conversion rods 51 and 52 are placed on the end faces of each other. Compared with the case where they are arranged so as to face each other, the dimension of the light source device 2 in the longitudinal direction can be substantially halved.

Generally, the light emitted from an LED has a larger diffusion angle than the light emitted from a semiconductor laser. Therefore, the light source using the LED tends to have a larger etendum determined by the product of the light emitting area of the light source and the solid angle of the light from the light source than the light source using the semiconductor laser. An increase in the intensity of the light source device increases the amount of light that cannot be captured by the optical system after the light source device, and causes a decrease in light utilization efficiency as a projector. Therefore, when used as a light source device for a projector, it is desirable that the etendue is as small as possible.

On the other hand, in the case of the light source device 2 of the present embodiment, the light having a large diffusion angle emitted from the LED 61 is incident on the wavelength conversion rods 51 and 52 from the side surface having a large area. On the other hand, the fluorescent KY is emitted from an end face whose area is sufficiently smaller than that of the side surfaces of the wavelength conversion rods 51 and 52. As described above, according to the present embodiment, the light emitting area can be substantially reduced, and the light source device 2 having a small etendue can be realized. As a result, by using the light source device 2 for the projector 1, it is possible to improve the light utilization efficiency in the optical system in the subsequent stage of the light source device 2.

In the lighting device 12 of the present embodiment, blue light B is emitted from the blue light source unit 13, yellow fluorescent KY is emitted from the light source device 2, and these lights are combined by the photosynthetic element 14 to illuminate white. Optical WL is obtained. Therefore, the white balance of the illumination light WL can be adjusted by adjusting the balance between the amount of blue light B and the amount of yellow fluorescent KY.

In the light source device 2 of the present embodiment, since the LED 61 is arranged so as to straddle the side surfaces 51c3, 51c4 of the first wavelength conversion rod 51 and the side surfaces 52c3, 52c4 of the second wavelength conversion rod 52, one LED61 Can be used as both the excitation light source for the first wavelength conversion rod and the excitation light source for the second wavelength conversion rod. As a result, the number of LEDs 61 can be minimized, and the configuration of the light source 35 can be simplified.

In the light source device 2 of the present embodiment, since the angle conversion element 56 is provided on the light emitting side of the first wavelength conversion rod 51, the fluorescence KY emitted from the first wavelength conversion rod 51 can be parallelized. it can. Further, since the collimator lens 57 is provided on the light emitting side of the angle conversion element 56, the parallelism of the fluorescence KY can be further increased. As a result, the light utilization efficiency in the optical system in the subsequent stage of the light source device 2 can be improved.

In the light source device 2 of the present embodiment, since the mirror 54 is provided on the fourth end surface 52b of the second wavelength conversion rod 52, the first fluorescence KY1 and the second fluorescence KY2 are emitted from the fourth end surface 52b. Is suppressed. Thereby, the utilization efficiency of the first fluorescent KY1 and the second fluorescent KY2 can be improved.

A reflective film made of, for example, a metal film may be provided between the side surface 51c1 of the first wavelength conversion rod 51 and the side surface 52c1 of the second wavelength conversion rod 52 instead of the gap (air layer). However, the loss of light on the side surface is smaller when the air layer is provided than when the reflective film is provided between the first wavelength conversion rod 51 and the second wavelength conversion rod 52. Therefore, when the suppression of light loss is important, it is preferable to provide an air layer between the first wavelength conversion rod 51 and the second wavelength conversion rod 52.

That is, in the light source device 2 of the present embodiment, since the side surface 51c1 of the first wavelength conversion rod 51 and the side surface 52c1 of the second wavelength conversion rod 52 face each other via the air layer, each wavelength conversion rod 51, The reflection of light on the side surfaces 51c1 and 52c1 of 52 is total reflection without light loss. As a result, the light utilization efficiency can be improved. Further, it is desirable that each side surface of each wavelength conversion rod 51, 52 is smoothly polished. As a result, the loss of light can be further suppressed.

Since the projector 1 of the present embodiment includes the above-mentioned light source device 2, it can be miniaturized and has excellent light utilization efficiency.

[Second Embodiment]
Hereinafter, the second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the light source device of the second embodiment is the same as that of the first embodiment, and is different from the first embodiment in that a third wavelength conversion rod is added. Therefore, the description of the overall configuration of the light source device will be omitted.
FIG. 4 is a schematic configuration diagram of the light source device 22 of the second embodiment.
In FIG. 4, the same components as those in FIG. 2 of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 4, the light source device 22 includes a first wavelength conversion rod 51 (first wavelength conversion unit), a second wavelength conversion rod 52 (second wavelength conversion unit), and a third wavelength conversion rod 53 (third wavelength conversion unit). It includes a three-wavelength conversion unit), a light source 36, a mirror 54 (reflection unit), a light guide unit 42, an angle conversion element 56, and a collimator lens 57.

Like the first wavelength conversion rod 51 and the second wavelength conversion rod 52, the third wavelength conversion rod 53 has a square columnar shape, and the fifth end surface 53a and the sixth end surface 53b and the fifth end surface 53a facing each other. And four sides that intersect the sixth end face 53b. All four aspects correspond to the fifth aspect of the claims. In the third wavelength conversion rod 53, the third fluorescence KY3 is emitted from the fifth end surface 53a.

The third wavelength conversion rod 53 includes a ceramic phosphor (third phosphor) that converts the wavelength of the third excitation light E3 into a third fluorescence KY3 having a third wavelength band. The third wavelength band is, for example, a yellow wavelength band of 490 to 750 nm. That is, the third wavelength conversion rod 53 includes a phosphor similar to the first wavelength conversion rod 51 and the second wavelength conversion rod 52, and emits a yellow third fluorescent KY3.

The first wavelength conversion rod 51 and the third wavelength conversion rod 53 are arranged at intervals so that the side surface 51c1 of the first wavelength conversion rod 51 and the side surface 53c1 of the third wavelength conversion rod 53 face each other. .. Further, the third wavelength conversion rod 53 and the second wavelength conversion rod 52 are arranged at intervals so that the side surface 53c2 of the third wavelength conversion rod 53 and the side surface 52c1 of the second wavelength conversion rod 52 face each other. ing. That is, the three wavelength conversion rods 51, 52, and 53 are arranged in parallel.

The first end face 51a (light emission end face) of the first wavelength conversion rod 51, the sixth end face 53b of the third wavelength conversion rod 53, and the third end face 52a (light emission end face) of the second wavelength conversion rod 52 are It is arranged at one end of each wavelength conversion rod 51, 52, 53 in the longitudinal direction. Further, the second end surface 51b of the first wavelength conversion rod 51, the fifth end surface 53a (light emission end surface) of the third wavelength conversion rod 53, and the fourth end surface 52b of the second wavelength conversion rod 52 are subjected to wavelength conversion. It is arranged at the other end of the rods 51, 52, 53 in the longitudinal direction.

The light source 36 is provided at a position facing one side surface of each wavelength conversion rod 51, 52, 53. In addition to the light source 36, a light source may be further provided at a position facing the other side surface of each wavelength conversion rod 51, 52, 53.

The light source 36 includes a substrate 363 and a plurality of LEDs 61 mounted on one surface of the substrate 363 facing each of the wavelength conversion rods 51, 52, 53. In this embodiment, 12 LEDs 61 are arranged in 2 rows of 6 each. The number of LEDs 61 is not particularly limited. Each LED 61 emits excitation light in a predetermined wavelength band. The wavelength band of the excitation light is, for example, an ultraviolet wavelength band of 200 nm to 380 nm. However, the wavelength band may be, for example, a purple wavelength band or a blue wavelength band of around 400 nm.

Each of the plurality of LEDs 61 is provided so as to face the two wavelength conversion rods. That is, the LED 61 (first light emitting element) in the right column in FIG. 4 is arranged so as to straddle the first wavelength conversion rod 51 and the third wavelength conversion rod 53, and the excitation light of the first wavelength conversion rod 51 It also serves as a light source for excitation light and a light source for excitation light of the third wavelength conversion rod 53. Therefore, the excitation light of the same wavelength band is incident on the first wavelength conversion rod 51 and the third wavelength conversion rod 53.

Further, the LED 61 (second light emitting element) in the left column in FIG. 4 is arranged so as to straddle the second wavelength conversion rod 52 and the third wavelength conversion rod 53, and the excitation light of the second wavelength conversion rod 52 It also serves as a light source for excitation light and a light source for excitation light of the third wavelength conversion rod 53. Therefore, the excitation light of the same wavelength band is incident on the second wavelength conversion rod 52 and the third wavelength conversion rod 53. The two rows of LEDs 61 may emit excitation light in the same wavelength band, or may emit excitation light in different wavelength bands. Of the excitation lights emitted from each LED 61, the excitation light incident on the first wavelength conversion rod 51 corresponds to the first excitation light E1, and the excitation light incident on the second wavelength conversion rod 52 is the second excitation light. Corresponding to E2, the excitation light incident on the third wavelength conversion rod 53 corresponds to the third excitation light E3.

The light guide unit 42 includes a first prism mirror 43 (first light guide unit) and a second prism mirror 44 (second light guide unit). Each of the first prism mirror 43 and the second prism mirror 44 is composed of a triangular columnar prism having a cross section of a right-angled isosceles triangle.

The first prism mirror 43 includes a first reflecting surface 43f1 facing the third end surface 52a of the second wavelength conversion rod 52, a third reflecting surface 43f3 facing the sixth end surface 53b of the third wavelength conversion rod 53, and light. It has an entry / exit end face 43ab and. The second prism mirror 44 has a second reflecting surface 44f2 facing the second end surface 51b of the first wavelength conversion rod 51 and a fourth reflecting surface facing the fifth end surface 53a of the third wavelength conversion rod 53. It has 44f4 and a light inlet / output end face 44ab.
Other configurations of the light source device 22 are the same as those in the first embodiment.

Hereinafter, the behavior of light in the light source device 22 of the present embodiment will be described.
When the second excitation light E2 is incident on the second wavelength conversion rod 52, the second phosphor contained in the second wavelength conversion rod 52 is excited, and the second fluorescence KY2 is emitted from an arbitrary light emitting point P2. The second fluorescence KY2 travels in all directions from an arbitrary light emitting point P2, but the second fluorescence KY2 facing the side surface repeats total reflection on the side surface, and the third end surface 52a or the fourth end surface. Proceed towards 52b. The second fluorescent KY2 toward the third end surface 52a is incident on the first prism mirror 43. On the other hand, the second fluorescent KY2 toward the fourth end surface 52b is reflected by the mirror 54, travels toward the third end surface 52a, and is incident on the first prism mirror 43.

The second fluorescent KY2 incident on the first prism mirror 43 is sequentially reflected by the first reflecting surface 43f1 and the third reflecting surface 43f3, so that the optical path is folded back and is incident on the third wavelength conversion rod 53 from the sixth end surface 53b. To do.

When the third excitation light E3 is incident on the third wavelength conversion rod 53, the third phosphor contained in the third wavelength conversion rod 53 is excited, and the third fluorescence KY3 is emitted from an arbitrary light emitting point P3. The third fluorescence KY3 travels in all directions from an arbitrary light emitting point P3, but the third fluorescence KY3 facing the side surface repeats total reflection on the side surface, and the fifth end surface 53a or the sixth end surface. Proceed towards 53b. The third fluorescent KY3 toward the fifth end surface 53a is incident on the second prism mirror 44. On the other hand, the third fluorescence KY3 toward the sixth end surface 53b follows a path opposite to that of the second fluorescence KY2 and is incident on the second wavelength conversion rod 52, but is reflected by the mirror 54 of the fourth end surface 52b. , Re-enters the third wavelength conversion rod 53 and proceeds toward the fifth end surface 53a.

The third fluorescent KY3 incident on the second prism mirror 44 is sequentially reflected by the fourth reflecting surface 44f4 and the second reflecting surface 44f2 of the second prism mirror 44, so that the optical path is folded back and the first from the second end surface 51b to the first. It is incident on the wavelength conversion rod 51. Further, the second fluorescence KY2 also passes through the third wavelength conversion rod 53 together with the third fluorescence KY3, passes through the second prism mirror 44, and is incident on the first wavelength conversion rod 51.

When the first excitation light E1 is incident on the first wavelength conversion rod 51, the first phosphor contained in the first wavelength conversion rod 51 is excited, and the first fluorescence KY1 is emitted from an arbitrary light emitting point P1. The first fluorescence KY1 travels in all directions from an arbitrary light emitting point P1, but the first fluorescence KY1 facing the side surface repeats total reflection on the side surface, and the first end surface 51a or the second end surface. Proceed towards 51b. The first fluorescence KY1 toward the first end surface 51a is incident on the angle conversion element 56. The first fluorescence KY1 directed toward the second end surface 51b follows a path opposite to that of the second fluorescence KY2 and is incident on the second wavelength conversion rod 52, but is reflected by the mirror 54 of the fourth end surface 52b and is the second. It re-enters the first wavelength conversion rod 51 via the three-wavelength conversion rod 53, and proceeds toward the first end surface 51a.

The second fluorescence KY2 and the third fluorescence KY3 incident on the first wavelength conversion rod 51 travel inside the first wavelength conversion rod 51 together with the first fluorescence KY1, and the first fluorescence KY1 and the second fluorescence KY2 And the yellow fluorescent KY composed of the third fluorescent KY3 is emitted from the first end surface 51a of the first wavelength conversion rod 51. The fluorescence KY emitted from the first wavelength conversion rod 51 is parallelized by the angle conversion element 56 and the collimator lens 57, and then emitted from the light source device 22.

Also in the second embodiment, the same effects as those in the first embodiment can be obtained, such as being able to realize a small light source device 22 and being able to realize a light source device 22 having a small etendue.

In particular, in the case of the present embodiment, since the three wavelength conversion rods 51, 52, 53 for emitting fluorescent KY1, KY2, and KY3 are arranged so that the side surfaces face each other, the three wavelength conversion rods 51, 52 , 53 can be reduced to approximately 1/3 in the longitudinal direction of the light source device 22 as compared with the case where the end faces face each other.

Further, according to the light source device 22 of the present embodiment, when the power supplied to the LED 61 is the same as that of the light source device of the first embodiment, a high-intensity fluorescent KY is obtained while maintaining a small etendue. be able to. Further, when the intensity of the fluorescence KY is the same between the present embodiment and the first embodiment, according to the light source device 22 of the present embodiment, the power supplied to the LED 61 is increased as compared with the light source device of the first embodiment. It can be reduced.

Further, according to the configuration of the present embodiment, the LEDs 61 for the excitation light can be dispersed and arranged while maintaining the high coupling efficiency of the excitation light. As a result, the LED 61 can be easily cooled, the efficiency of the light source 36 can be improved, and the cooling system can be downsized.

[Third Embodiment]
Hereinafter, the third embodiment of the present invention will be described with reference to FIGS. 5 and 6.
The basic configuration of the projector of the third embodiment is the same as that of the first embodiment, and is different from the first embodiment in that it does not have a blue light source unit. Therefore, the description of the overall configuration of the projector will be omitted.
Further, the basic configuration of the light source device of the third embodiment is the same as that of the first embodiment, and the configurations of the first wavelength conversion rod and the light source are different from those of the first embodiment. Therefore, the description of the overall configuration of the light source device will be omitted.

FIG. 5 is a schematic configuration diagram of the projector 11. FIG. 6 is a schematic configuration diagram of the light source device 23.
In FIGS. 5 and 6, the same components as those in FIGS. 1 and 2 of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 5, the projector 11 of the present embodiment includes a light source device 23, a uniform illumination optical system 40, a color separation optical system 3, an optical modulator 4R, an optical modulator 4G, and an optical modulator 4B. A synthetic optical system 5 and a projection optical device 6 are provided. In this embodiment, the light source device 23 emits white light.

As shown in FIG. 6, the light source device 23 of the present embodiment includes a first wavelength conversion rod 71 (first wavelength conversion unit), a second wavelength conversion rod 52 (second wavelength conversion unit), and a light source 37. It includes a mirror 54 (reflection unit), a prism mirror 55 (light source unit), an angle conversion element 56, and a collimator lens 57.

The first wavelength conversion rod 71 has a square columnar shape, and has four side surfaces 71c1, 71c2, 71c3 that intersect the first end surface 71a and the second end surface 71b facing each other and the first end surface 71a and the second end surface 71b. , 71c4 and. The entire four sides 71c1, 71c2, 71c3, 71c4 correspond to the first side of the claims. In the first wavelength conversion rod 71, the fluorescence KW is emitted from the first end surface 71a. Further, as in the first embodiment, the first wavelength conversion rod 71 may be another polygonal prism such as a triangular prism, or may be a columnar prism. The second wavelength conversion rod 52 is the same as that of the first embodiment.

The first wavelength conversion rod 71 and the second wavelength conversion rod 52 are arranged at intervals so that the side surface 71c1 of the first wavelength conversion rod 71 and the side surface 52c1 of the second wavelength conversion rod 52 face each other. .. Further, the first end surface 71a (light emission end surface) of the first wavelength conversion rod 71 and the fourth end surface 52b of the second wavelength conversion rod 52 are arranged at one end in the longitudinal direction of the wavelength conversion rods 71 and 52, and the first one. The second end surface 71b of the wavelength conversion rod 71 and the third end surface 52a (light emission end surface) of the second wavelength conversion rod 52 are arranged at the other ends of the wavelength conversion rods 71 and 52 in the longitudinal direction.

The light source 37 is provided at a position facing one side surface of each of the wavelength conversion rods 71 and 52. In addition to the light source 37, a light source may be further added at a position facing the other side surface of each of the wavelength conversion rods 71 and 52.

The light source 37 includes a substrate 371 and a plurality of light emitting diodes 63 and 64 (LEDs) mounted on one surface of the substrate 371 facing the wavelength conversion rods 71 and 52. In this embodiment, the light source includes 12 LEDs 63, 64, and 12 LEDs 63, 64 are arranged in two rows of 6 each. The number of LEDs 63 and 64 is not particularly limited.

The six LEDs 63 in the right column in FIG. 6 are arranged along the longitudinal direction of the first wavelength conversion rod 71. The six LEDs 64 in the left column are arranged along the longitudinal direction of the second wavelength conversion rod 52. Hereinafter, the LEDs 63 arranged along the longitudinal direction of the first wavelength conversion rod 71 will be referred to as the first LED 63 (first light emitting element), and the LEDs 64 arranged along the longitudinal direction of the second wavelength conversion rod 52 will be referred to as the second LED 64 (second LED 64). Second light emitting element). The first LED 63 faces the side surface of the first wavelength conversion rod 71, and the second LED 64 faces the side surface of the second wavelength conversion rod 52.

The first excitation light E1 emitted from the first LED 63 functions as excitation light that excites the first phosphor contained in the first wavelength conversion rod 71 after being incident on the first wavelength conversion rod 71. On the other hand, the second excitation light E2 emitted from the second LED 64 functions as excitation light that excites the second phosphor contained in the second wavelength conversion rod 52 after being incident on the second wavelength conversion rod 52.

Therefore, the first LED 63 and the second LED 64 may emit light of different wavelength bands optimized for each of the first phosphor and the second phosphor, and are common to both phosphors. Light of the same wavelength band used may be emitted. The wavelength band of the first excitation light E1 and the second excitation light E2 is, for example, an ultraviolet wavelength band of 200 nm to 380 nm. However, the wavelength bands of the excitation lights E1 and E2 may be, for example, a purple wavelength band or a blue wavelength band of around 400 nm.

The first wavelength conversion rod 71 is made of, for example, fluorescent glass in which rare earth ions are dispersed in glass, or a material in which a blue phosphor is dispersed in a binder such as glass or resin. Specifically, as the fluorescent glass, Lumirasu (trade name, manufactured by Sumita Optical Glass, Inc.) or the like is used. As the blue phosphor (first phosphor), for example, BaMgAl ₁₀ O ₁₇ : Eu (II) or the like is used. The first wavelength conversion rod 71 converts the first excitation light E1 into a first fluorescent KB (blue light) having a first wavelength band. The first wavelength band is, for example, a blue wavelength band of 450 to 495 nm. The first fluorescent KB is emitted from the first end surface 71a of the first wavelength conversion rod 71.

The second wavelength conversion rod 52 is composed of a ceramic phosphor (second phosphor) that converts the second excitation light E2 into a second fluorescence KY having a second wavelength band, as in the first embodiment. ing. The second wavelength band is, for example, a yellow wavelength band of 490 to 750 nm. The second wavelength conversion rod 52 may be made of a material in which a large number of phosphor particles are dispersed in a binder such as a single crystal phosphor, fluorescent glass, or glass or resin. The second fluorescence KY is emitted from the third end surface 52a of the second wavelength conversion rod 52.
Other configurations of the light source device 23 are the same as those in the first embodiment.

In the light source device 23 of the present embodiment, the first fluorescent KB is blue light, the second fluorescent KY is yellow light, and the color of the first fluorescent KB and the color of the second fluorescent KY are mutual. different. Therefore, the color of the first fluorescent KB is different from that of the first embodiment, and the traveling paths of the fluorescent KB and KY are the same as those of the first embodiment. Of the first fluorescent KB emitted by the first wavelength conversion rod 71, the first fluorescent KB that has advanced toward the second end surface 71b is incident on the second wavelength conversion rod 52 via the prism mirror 55. At least a part of the incident first fluorescent KB functions as the excitation light of the second wavelength conversion rod 52.

Also in the third embodiment, the same effects as those in the first embodiment can be obtained, such as being able to realize a small light source device 23 and being able to realize a light source device 23 having a small etendue.

In particular, in the case of the present embodiment, the first wavelength conversion rod 71 produces a blue first fluorescent KB, and the second wavelength conversion rod 52 produces a yellow second fluorescent KY. Therefore, a white fluorescent KW composed of the first fluorescent KB and the second fluorescent KY is emitted from the first end surface 71a of the first wavelength conversion rod 71. Therefore, unlike the first embodiment, it is not necessary to provide a blue light source unit for obtaining white light separately from the light source device 23. As a result, the illumination optical system of the projector 11 can be further miniaturized.

In the light source device 23 of the present embodiment, the power supplied to each of the first LED 63 and the second LED 64 is adjusted, and the intensity of the first excitation light E1 and the intensity of the second excitation light E2 are individually controlled. , The light intensity of each of the first fluorescent KB and the second fluorescent KY may be controlled. Thereby, the white balance of the illumination light WL can be adjusted. Further, by adopting means such as making the length or width of the first wavelength conversion rod 71 and the second wavelength conversion rod 52 different, or making the numbers of the first LED 63 and the second LED 64 different, the light source device 23 The white balance may be adjusted at the design stage.

[Fourth Embodiment]
Hereinafter, the fourth embodiment of the present invention will be described with reference to FIG. 7.
The light source device of the fourth embodiment is similar to the second embodiment in that it includes three wavelength conversion rods, and the color of fluorescence obtained from each wavelength conversion rod and the configuration of the light source are different from those of the second embodiment. .. Therefore, the description of the overall configuration of the light source device will be omitted.
FIG. 7 is a schematic configuration diagram of the light source device 24.
In FIG. 7, components common to those in FIG. 2 of the first embodiment and FIG. 4 of the second embodiment are designated by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 7, the light source device 24 includes a first wavelength conversion rod 71 (first wavelength conversion unit), a second wavelength conversion rod 72 (second wavelength conversion unit), and a third wavelength conversion rod 73 (third wavelength conversion unit). It includes a three-wavelength conversion unit), a light source 38, a mirror 54 (reflection unit), a light guide unit 42, an angle conversion element 56, and a collimator lens 57. The light guide unit 42 includes a first prism mirror 43 (first light guide unit) and a second prism mirror 44 (second light guide unit).

The first wavelength conversion rod 71 has a first end surface 71a and a second end surface 71b facing each other, and four side surfaces intersecting the first end surface 71a and the second end surface 71b. The second wavelength conversion rod 72 has a third end face 72a and a fourth end face 72b facing each other, and four side surfaces intersecting the third end face 72a and the fourth end face 72b. The third wavelength conversion rod 73 has a fifth end face 73a and a sixth end face 73b facing each other, and four side surfaces intersecting the fifth end face 73a and the sixth end face 73b.

The arrangement of the wavelength conversion rods 71, 72, and 73 is the same as that of the second embodiment. That is, the first wavelength conversion rod 71 and the third wavelength conversion rod 73 are arranged at intervals so that the side surface 71c1 of the first wavelength conversion rod 71 and the side surface 73c1 of the third wavelength conversion rod 73 face each other. ing. Further, the third wavelength conversion rod 73 and the second wavelength conversion rod 72 are arranged at intervals so that the side surface 73c2 of the third wavelength conversion rod 73 and the side surface 72c1 of the second wavelength conversion rod 72 face each other. ing. That is, the three wavelength conversion rods 71, 72, 73 are arranged in parallel.

The light source 38 is provided at a position facing one side surface of each wavelength conversion rod 71, 72, 73. In addition to the light source 38, a light source may be further added at a position facing the other side surface of each wavelength conversion rod 71, 72, 73.

The light source 38 includes a substrate 383 and a plurality of LEDs 81, 82, 83 mounted on one surface of the substrate 383 facing the first wavelength conversion rod 71, the second wavelength conversion rod 72, and the third wavelength conversion rod 73. .. In the present embodiment, the light source 38 includes a total of 18 LEDs 81, 82, 83, but the number of LEDs 81, 82, 83 is not particularly limited. Each of the LEDs 81, 82, and 83 emits a first excitation light E1, a second excitation light E2, and a third excitation light E3.

The plurality of LEDs 81, 82, and 83 are provided so as to face each of the side surface of the first wavelength conversion rod 71, the side surface of the second wavelength conversion rod 72, and the side surface of the third wavelength conversion rod 73. A plurality of LEDs 81, 82, and 83 are arranged in three rows of six. Some LEDs 81 are arranged along the longitudinal direction of the first wavelength conversion rod 71, some other LEDs 82 are arranged along the longitudinal direction of the second wavelength conversion rod 72, and some others. The LEDs 83 are arranged along the longitudinal direction of the third wavelength conversion rod 73. Hereinafter, the LEDs arranged along the longitudinal direction of the first wavelength conversion rod 71 are referred to as the first LED 81 (first light emitting element), and the LEDs arranged along the longitudinal direction of the second wavelength conversion rod 72 are referred to as the second LED 82 (the second LED 82 (1st light emitting element). The second light emitting element), and the LEDs arranged along the longitudinal direction of the third wavelength conversion rod 73 are referred to as the third LED 83.

The first excitation light E1 that excites the first phosphor contained in the first wavelength conversion rod 71 is emitted from the first LED 81. The second excitation light E2 that excites the second phosphor contained in the second wavelength conversion rod 72 is emitted from the second LED 82. A third excitation light E3 that excites the third phosphor contained in the third wavelength conversion rod 73 is emitted from the third LED 83. The first excitation light E1, the second excitation light E2, and the third excitation light E3 have different phosphors to be excited. Therefore, the first LED 81, the second LED 82, and the third LED 83 may emit light of different wavelength bands optimized for each of the phosphors of the wavelength conversion rods 71, 72, and 73, or any fluorescence. Light in the same wavelength band, which is commonly used as excitation light, may be emitted to the body.

In the present embodiment, the first LED 81 is provided so as to face the side surface of the first wavelength conversion rod 71, and emits the first excitation light E1 toward the side surface. The wavelength band of the first excitation light E1 is, for example, an ultraviolet wavelength band of 200 nm to 380 nm. However, the wavelength band may be, for example, a purple wavelength band of around 400 nm.

The second LED 82 is provided so as to face the side surface of the second wavelength conversion rod 72, and emits the second excitation light E2 toward the side surface. The wavelength band of the second excitation light E2 is, for example, a blue wavelength band of 450 nm to 495 nm. However, the wavelength band may be, for example, an ultraviolet wavelength band of 200 nm to 380 nm, or a purple wavelength band of around 400 nm.

The third LED 83 is provided so as to face the side surface of the third wavelength conversion rod 73, and emits the third excitation light E3 toward the side surface. The wavelength band of the third excitation light E3 is, for example, a blue wavelength band of 450 nm to 495 nm. However, the wavelength band may be, for example, an ultraviolet wavelength band of 200 nm to 380 nm, or a purple wavelength band of around 400 nm.

The first wavelength conversion rod 71 converts the first excitation light E1 into the first fluorescent KB (blue light) in the first wavelength band. The first wavelength band is, for example, a blue wavelength band of 450 to 495 nm. The first wavelength conversion rod 71 is made of, for example, fluorescent glass in which rare earth ions are dispersed in glass, a material in which a blue phosphor is dispersed in a binder such as glass or resin, and the like. Specifically, as the fluorescent glass, Lumirasu (trade name, manufactured by Sumita Optical Glass, Inc.) or the like is used. As the blue phosphor (first phosphor), for example, BaMgAl ₁₀ O ₁₇ : Eu (II) or the like is used.

The second wavelength conversion rod 72 converts the second excitation light E2 into the second fluorescent KR (red light) in the second wavelength band. The second wavelength band is, for example, a red wavelength band of 600 to 800 nm. In the second wavelength conversion rod 72, any one of Pr, Eu, and Cr was dispersed as a red phosphor (second phosphor), for example, as an activator (Y _1-x , Gd _x ) ₃ (Al, Ga). _It contains a YAG-based phosphor (any of Pr: YAG, Eu: YAG, Cr: YAG) composed of 5 O _12. The activator may contain one selected from Pr, Eu and Cr, or may be a co-activated activator containing a plurality of types selected from Pr, Eu and Cr.

The third wavelength conversion rod 73 converts the third excitation light E3 into a third fluorescent KG (green light) in the third wavelength band. The second wavelength band is, for example, a green wavelength band of 500 to 570 nm. The third wavelength conversion rod 73 may be a green phosphor (third phosphor), for example, Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ system phosphor, Y ₃ O ₄ : Eu ²⁺ system phosphor, (Ba, Sr) _2. SiO ₄ : Eu ²⁺ fluorescent material, Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ fluorescent material, (Si, Al) ₆ (O, N) ₈ : Eu ²⁺ fluorescent material and other phosphor materials are included. There is.
Other configurations of the light source device 24 are the same as those in the second embodiment.

In the light source device 24 of the present embodiment, the first wavelength band of the first fluorescence KB is the blue wavelength band, the second wavelength band of the second fluorescence KR is the red wavelength band, and the third fluorescence. The third wavelength band of KG is the green wavelength band. As described above, the color of the first fluorescent KB, the color of the second fluorescent KR, and the color of the third fluorescent KG are different from each other. In this embodiment, the colors of the fluorescent KBs, KRs, and KGs are different from those in the second embodiment, and the traveling paths of the fluorescent KBs, KRs, and KGs are the same as those in the second embodiment.

Also in the fourth embodiment, the same effects as those in the first embodiment can be obtained, such as being able to realize a small light source device 24 and being able to realize a light source device 24 having a small etendue. Further, it is not necessary to provide the blue light source unit separately from the light source device 24, and the same effect as that of the third embodiment can be obtained, such as further miniaturization of the illumination optical system.

In the light source device 24 of the present embodiment, the power supplied to each of the first LED 81, the second LED 82, and the third LED 83 is adjusted, and the intensity of the first excitation light E1, the intensity of the second excitation light E2, and the third excitation light are adjusted. By individually controlling the intensity of E3, the amount of light of each of the first fluorescence KB, the second fluorescence KR, and the third fluorescence KG may be controlled. Thereby, the white balance of the illumination light WL can be adjusted. Further, means such as different lengths or widths of the first wavelength conversion rod 71, the second wavelength conversion rod 72 and the third wavelength conversion rod 73, and different numbers of the first LED 81, the second LED 82 and the third LED 83 are adopted. As a result, the white balance may be adjusted at the design stage of the light source device 24.

In the case of the present embodiment, the second fluorescence KR (red light) emitted by the second wavelength conversion rod 72 is incident on the third wavelength conversion rod 73, and the third fluorescence emitted by the third wavelength conversion rod 73. KG (green light) is incident on the first wavelength conversion rod 71 together with the second fluorescence, and the first fluorescent KB (blue light) emitted by the first wavelength conversion rod 71 is the third fluorescent KG (green light). And emitted from the first wavelength conversion rod 71 together with the second fluorescent KR (red light). In this way, since the fluorescence having a relatively long wavelength is incident on the wavelength conversion rod that emits the fluorescence having a relatively short wavelength, the fluorescence emitted by one wavelength conversion rod is the wavelength conversion of the next stage. It is not consumed as excitation light when it enters the rod. As a result, according to the light source device 24 of the present embodiment, the white balance can be maintained.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the light guide unit shown below may be used instead of the light guide unit of the above embodiment.

FIG. 8 is a schematic configuration diagram of a light guide portion of the first modification.
As shown in FIG. 8, the light guide portion 67 of the first modification has a prism mirror 55 and a glass block 58. Specifically, the light guide unit 67 includes a triangular columnar first prism 551 provided with a first reflecting surface 55f1, a triangular columnar second prism 552 provided with a second reflecting surface 55f2, and a square columnar glass block 58. And have. The glass block 58 is provided between the first prism 551 and the second prism 552.

Of the plurality of surfaces of the glass block 58, the first surface 58a is in contact with the first prism 551, and the second surface 58b facing the first surface 58a is in contact with the second prism 552. Reflective films 59 are provided on the third surface 58c and the fourth surface 58d, which intersect the first surface 58a and the second surface 58b, respectively. That is, the glass block 58 has a function of guiding light inside.

FIG. 9 is a diagram for explaining a problem of the light guide unit of the first embodiment.
As shown in FIG. 9, in the prism mirror 55 of the first embodiment, the fluorescence KY emitted from the third end surface 52a of the second wavelength conversion rod 52 at an injection angle of 45 ° is perpendicular to the second reflection surface 55f2. Incident in. Therefore, the fluorescence KY is reflected by the second reflection surface 55f2, is folded back in the direction opposite to the direction in which the optical path is incident, and returns to the second wavelength conversion rod 52. As described above, the fluorescence KY returning to the second wavelength conversion rod 52 becomes a loss, and the light utilization efficiency may decrease.

On the other hand, as shown in FIG. 8, in the light guide portion 67 of the first modification, the fluorescent KY emitted from the third end surface 52a of the second wavelength conversion rod 52 at an injection angle of 45 ° is the glass block 58. It is vertically incident on the third surface 58c of the above at an incident angle of 45 °. After that, the fluorescent KY is reflected by the reflective film 59 and is incident on the first wavelength conversion rod 51 from the second end surface 51b. As described above, according to the light guide unit 67 of the first modification, the fluorescent KY emitted at the above angle is unlikely to return to the second wavelength conversion rod 52, and is likely to be incident on the first wavelength conversion rod 51. , Light utilization efficiency can be improved.

FIG. 10 is a schematic configuration diagram of the light guide unit 46 of the second modification.
As shown in FIG. 10, the light guide unit 46 of the second modification is composed of a light guide body having a shape in which a cylinder is divided in half by a plane including the central axis of the cylinder. The light inlet / output end surface 46ab of the light guide unit 46 faces the third end surface 52a of the second wavelength conversion rod 52 and the second end surface 51b of the first wavelength conversion rod 51. Further, the reflecting surface 46f of the light guide unit 46 reflects the second fluorescent KY emitted from the second wavelength conversion rod 52. That is, the light guide portion 46 of the modified example has a reflecting surface 46f provided so as to face the third end surface 52a of the second wavelength conversion rod 52 and the second end surface 51b of the first wavelength conversion rod 51. Even with such a light guide unit 46, the second fluorescence KY emitted from the second wavelength conversion rod 52 can be guided to the first wavelength conversion rod 51.

Further, in the above embodiment, the example in which the second wavelength conversion rod contains a phosphor that emits yellow fluorescence is given, but the second wavelength conversion rod emits a fluorescent substance that emits green fluorescence and a red fluorescence. It may contain two kinds of phosphors including the fluorescent substance to be emitted. In that case, the two types of phosphors may be evenly mixed inside the second wavelength conversion rod, or may be unevenly distributed in different regions.

Further, in the third embodiment in which the colors of the fluorescence emitted by each wavelength conversion rod are different from each other, the first wavelength band of the first fluorescence is the green wavelength band, and the second wavelength band of the second fluorescence is red. It may be in the wavelength band. According to this configuration, it is possible to realize a light source device that can obtain yellow fluorescence. Therefore, it can be applied to the lighting device of the projector of the first embodiment that generates white light together with the blue light source unit.

Further, in each of the above embodiments, a dichroic mirror that reflects the first excitation light and transmits the first fluorescence and the second fluorescence may be provided on the first end surface of the first wavelength conversion rod. .. Further, a dichroic mirror that reflects the second excitation light and transmits the second fluorescence may be provided on the third end surface of the second wavelength conversion rod. In the fourth embodiment, a dichroic mirror that reflects the third excitation light and transmits the third fluorescence may be provided on the fifth end surface of the third wavelength conversion rod. According to these configurations, the wavelength conversion efficiency of each wavelength conversion rod can be increased. Further, a dichroic mirror that transmits excitation light and reflects fluorescence may be provided on the side surface of each wavelength conversion rod.

Further, the specific configuration of the shape, number, arrangement, material, and the like of each component constituting the light source device is not limited to the above embodiment, and can be appropriately changed.

In the above embodiment, an example in which the present invention is applied to a transmissive liquid crystal projector has been described, but the present invention can also be applied to a reflective liquid crystal projector. Here, the "transmissive type" means that the liquid crystal light bulb including the liquid crystal panel or the like transmits light. The "reflective type" means that the liquid crystal light bulb reflects light.

In the above embodiment, an example of a projector using three liquid crystal panels has been given, but the present invention is also applicable to a projector using only one liquid crystal light bulb and a projector using four or more liquid crystal light bulbs. Is.

In the above embodiment, an example in which the light source device according to the present invention is mounted on a projector is shown, but the present invention is not limited thereto. The light source device according to the present invention can also be applied to lighting equipment, automobile headlights, and the like.

1,11 ... Projector, 2,22,23,24 ... Light source device, 4B, 4G, 4R ... Optical modulator, 6 ... Projection optical device, 35,36,37,38 ... Light source, 42,46,67 ... Light unit, 43 ... 1st prism mirror (1st light guide unit), 43f1, 55f1 ... 1st reflection surface, 44 ... 2nd prism mirror (2nd light guide unit), 44f2, 55f2 ... 2nd reflection surface, 46f , 55f ... Reflective surface, 51, 71 ... First wavelength conversion rod (first wavelength conversion unit), 51a, 71a ... First end surface, 51b, 71b ... Second end surface, 52, 72 ... Second wavelength conversion rod (first) 2 wavelength conversion unit), 52a, 72a ... 3rd end face, 52b, 72b ... 4th end surface, 53, 73 ... 3rd wavelength conversion rod (3rd wavelength conversion unit), 53a, 73a ... 5th end surface, 53b, 73b ... 6th end face, 54 ... Mirror (reflection part), 55 ... Prism mirror (light guide part), 61 ... LED, 63, 81 ... 1st LED (1st light emitting element), 64, 82 ... 2nd LED (2nd light emitting element) Element), E1 ... 1st excitation light, E2 ... 2nd excitation light, KB, KY1 ... 1st fluorescence, KR, KY2 ... 2nd fluorescence, KG, KY3 ... 3rd fluorescence.

Claims (16)

A light source that emits excitation light and
A first wavelength conversion unit that includes a first phosphor and converts the excitation light into first fluorescence having a first wavelength band different from the wavelength band of the excitation light.
A second wavelength conversion unit that includes a second phosphor and converts the excitation light into a second fluorescence having a second wavelength band different from the wavelength band of the excitation light.
A light guide unit that guides the second fluorescence emitted from the second wavelength conversion unit to the first wavelength conversion unit, and
With
The first wavelength conversion unit has a first end face and a second end face facing each other, and a first side surface intersecting the first end face and the second end face.
The second wavelength conversion unit has a third end face and a fourth end face facing each other, and a second side surface intersecting the third end face and the fourth end face.
The first side surface of the first wavelength conversion unit and the second side surface of the second wavelength conversion unit face each other.
The light guide portion is composed of a prism mirror , a reflection surface facing the third end surface of the second wavelength conversion unit and the second end surface of the first wavelength conversion unit, and the second wavelength conversion unit. It has a light input / output end surface in which the second fluorescence emitted from the third end surface is incident and the second fluorescence reflected by the reflection surface is emitted .
The light input / output end faces are arranged so as to face the second end face of the first wavelength conversion unit and the third end surface of the second wavelength conversion unit.
A light source device in which the first fluorescence and the second fluorescence are emitted from the first end surface of the first wavelength conversion unit. The light source device according to claim 1, further comprising a reflecting unit that is provided on the fourth end surface of the second wavelength conversion unit and reflects the second fluorescence that guides the inside of the second wavelength conversion unit. .. The reflection surface of the light guide unit includes a first reflection surface facing the third end surface of the second wavelength conversion unit and a second reflection surface facing the second end surface of the first wavelength conversion unit. Have and
The second fluorescence emitted inside the second wavelength conversion unit is emitted from the third end surface, reflected by the first reflection surface, reflected by the second reflection surface, and from the second end surface. The light source device according to claim 1 or 2, which is incident on the first wavelength conversion unit and emitted from the first end face. The light guide unit
The first prism having the first reflecting surface and
The second prism having the second reflecting surface and
The light source device according to claim 3, further comprising a glass block provided between the first prism and the second prism. Further provided with a third wavelength converter that includes a third phosphor and emits a third fluorescence having a third wavelength band different from the first wavelength band and the second wavelength band.
The third wavelength conversion unit has a fifth end face and a sixth end face facing each other, and a fifth side surface intersecting the fifth end face and the sixth end face.
The first side surface of the first wavelength conversion unit and the fifth side surface of the third wavelength conversion unit face each other.
The second side surface of the second wavelength conversion unit and the fifth side surface of the third wavelength conversion unit face each other.
The light guide unit
A first light guide unit having a first reflection surface and a third reflection surface facing the sixth end surface of the third wavelength conversion unit.
The light source according to claim 3 or 4, further comprising a second light guide portion having a second reflecting surface and a fourth reflecting surface facing the fifth end surface of the third wavelength conversion unit. apparatus. The light source according to any one of claims 1 to 5, wherein the light source includes a first light emitting element that emits a first excitation light and a second light emitting element that emits a second excitation light. Light source device. The first wavelength conversion unit has a third side surface that intersects the first end face and the second end face.
The second wavelength conversion unit has a fourth side surface that intersects the third end surface and the fourth end surface.
The first excitation light is incident on the first wavelength conversion unit from the third side surface of the first wavelength conversion unit.
The light source device according to claim 6, wherein the second excitation light is incident on the second wavelength conversion unit from the fourth side surface of the second wavelength conversion unit. The light source is provided so as to face the third side surface of the first wavelength conversion unit and the fourth side surface of the second wavelength conversion unit, and emits the first excitation light and the second excitation light. The light source device according to claim 7 , further comprising a light emitting diode. The light source device according to any one of claims 6 to 8, wherein the wavelength band of the first excitation light and the wavelength band of the second excitation light are different. The light source device according to any one of claims 1 to 9, wherein the first wavelength band and the second wavelength band are the same wavelength band. The light source device according to any one of claims 1 to 9, wherein the first wavelength band and the second wavelength band are different wavelength bands. The light source device according to claim 11, wherein the first wavelength band is a blue wavelength band, and the second wavelength band is a yellow wavelength band. The light source device according to claim 11, wherein the first wavelength band is a green wavelength band, and the second wavelength band is a red wavelength band. The light source device according to claim 5, wherein the first wavelength band is a blue wavelength band, the second wavelength band is a red wavelength band, and the third wavelength band is a green wavelength band. An angle conversion element provided on the light emitting side of the first wavelength conversion unit, having a light incident end face and a light emitting end face, and making the diffusion angle at the light emitting end face smaller than the diffusion angle at the light incident end face is further provided. The light source device according to any one of claims 1 to 14, which is provided. The light source device according to any one of claims 1 to 15.
An optical modulation device that modulates the light from the light source device according to image information,
A projector including a projection optical device that projects light modulated by the light modulation device.

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