JP2013114980A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device that can further increase its luminance without decreasing utilization efficiency of light.SOLUTION: The light source device includes a first light source part 10 which includes a plurality of first solid light sources 13 for emitting first excitation light, a second light source part 20 which includes a plurality of second solid light sources 23 for emitting second excitation light, an excitation light synthesizing part 30 which synthesizes the plurality of kinds of first excitation light emitted from the first light source part 10 and the plurality of kinds of second excitation light emitted from the second light source part 20 and emits as synthesized excitation light, a lens array 51 which divides the synthesized excitation light emitted from the excitation light synthesizing part 30 into a plurality of partial fluxes of light, a condensing optical system which condenses the plurality of partial fluxes of light, and a light-emitting element 80 which is excited by the plurality of partial fluxes of light condensed by the condensing optical system and emits fluorescence.

Description

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

  2. Description of the Related Art Conventionally, a light source device that includes a plurality of solid light sources that emit excitation light and a phosphor layer that emits fluorescence when excited by excitation light emitted from the plurality of solid light sources is known. Further, a projector including such a light source device is known (for example, Japanese Patent Application Laid-Open No. 2004-327361).

  In the conventional light source device, the phosphor layer is arranged at a condensing position where excitation light from a plurality of solid light sources is condensed. For this reason, the light quantity of fluorescence can be increased without increasing the area of the light emitting region in which fluorescence is emitted from the phosphor layer, that is, etendue. Therefore, the brightness of the light source device can be increased without reducing the light use efficiency.

JP 2004-327361 A

  In the technical field of light source devices, there is a demand for light source devices that can further increase the luminance of the light source device without reducing the light utilization efficiency.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light source device that can further increase the luminance of the light source device without reducing the light use efficiency. It is another object of the present invention to provide a projector that includes such a light source device and can further increase the luminance of a display screen without reducing the light use efficiency.

  In order to solve the above problems, a light source device according to the present invention includes a first light source unit including a plurality of first solid light sources that emit first excitation light, and a plurality of second solids that emit second excitation light. A second light source unit including a light source, a plurality of the first excitation lights emitted from the first light source unit, and a plurality of the second excitation lights emitted from the second light source unit are synthesized and synthesized. An excitation light combining unit that emits as excitation light, a lens array that divides the combined excitation light emitted from the excitation light combining unit into a plurality of partial beam bundles, and a condensing optical system that collects the plurality of partial beam bundles And a light emitting element that emits fluorescence when excited by the plurality of partial beam bundles condensed by the condensing optical system.

  According to this configuration, fluorescence is emitted using excitation light emitted from two light source parts (first light source part and second light source part) including a plurality of solid light sources. For this reason, the brightness | luminance of a light source device can be made still higher. In the present specification, the first light source unit and the second light source unit may be collectively referred to as two light source units.

  Further, the excitation light from the two light source units is synthesized using the excitation light synthesis unit and then condensed on the light emitting element. For this reason, compared with the case where the excitation light from two light source parts is synthesize | combined without using the excitation light synthetic | combination part which concerns on this invention, it is in a smaller area | region of a light emitting element with a smaller incident angle with respect to a light emitting element. Excitation light can be incident. That is, the increase in etendue can be reduced. Also in this sense, it is possible to reduce the decrease in the use efficiency of the fluorescent light caused by using the two light source units.

  In addition, excitation light from the two light source units is superimposed on the light emitting element through the lens array and the condensing optical system, and the light intensity distribution is averaged. Therefore, it becomes possible to irradiate the entire light emitting element with excitation light with uniform light intensity. This makes it easy to control the amount of light so that local light saturation does not occur within the region irradiated with the excitation light. Therefore, the luminance of the light source device can be further increased without reducing the utilization efficiency of the excitation light.

  In the light source device, the excitation light combining unit includes a polarization separation film that transmits light incident as P-polarized light and reflects light incident as S-polarized light, and the plurality of first excitation lights are combined with the excitation light. It is preferable that the light is incident on the part as P-polarized light, and the plurality of second excitation lights are incident on the excitation light combining part as S-polarized light.

  According to this configuration, it is possible to synthesize the first excitation light and the second excitation light with high efficiency using the principle of the polarization separation film.

  In the light source device, the excitation light synthesizer further includes a first transparent member and a second transparent member provided so as to sandwich the polarization separation film, and the first one of the plurality of first excitation lights. The excitation light enters the polarization separation film through the first transparent member, and one second excitation light among the plurality of second excitation lights passes through the second transparent member. It is preferable to be incident on.

  According to this configuration, the excitation light from the two light source units enters the polarization separation film after passing through the transparent member. Therefore, even if the refractive index difference is large between the polarization separation film and the air layer (the medium through which the excitation light from the two light source units enters the polarization separation film), the refractive index difference is alleviated. can do. Therefore, the light generated by the difference in the refractive index is larger than the configuration in which the excitation light from the two light source units is directly incident on the polarization separation film without the transparent member according to the present invention being formed on the polarization separation film. Loss can be reduced.

  In the light source device, the excitation light synthesizer includes an interface between the first transparent member and the polarization separation film, and an interface between the second transparent member and the polarization separation film. It is preferable that they are arranged so as to overlap each other with a gap therebetween.

  According to this configuration, in the case where each of the first excitation light and the second excitation light is configured to enter the regions facing each other across the polarization separation film in the excitation light combining unit, the transparent member It becomes easy to relax the refractive index difference. Therefore, it is possible to suppress the loss of light due to the large difference in refractive index.

  In the light source device, the excitation light synthesizer includes an interface between the first transparent member and the polarization separation film, and an interface between the second transparent member and the polarization separation film. It is preferable that they are arranged so as to partially overlap each other.

  According to this configuration, the region where the first excitation light is incident on the polarization separation film and the region where the second excitation light is incident on the polarization separation film are arranged so as to partially overlap each other in the polarization separation film. Therefore, it is possible to suppress the occurrence of unevenness in the synthetic excitation light.

  In the light source device, it is preferable that the excitation light synthesizer includes a passing region that allows the plurality of first excitation lights to pass therethrough and a reflection region that reflects the plurality of second excitation lights.

  According to this configuration, it is possible to synthesize the first excitation light and the second excitation light with high efficiency. For example, in the case where the excitation light combining unit has an opening in the passage region, it is possible to suppress the loss of light due to the first excitation light passing through the opening of the excitation light combining unit.

  In the light source device, each of the plurality of first solid-state light sources and the plurality of second solid-state light sources includes a semiconductor laser, and the semiconductor laser includes a rectangular light-emitting region in a plan view, and a short side of the light-emitting region The light spreading angle along the direction is configured to be larger than the light spreading angle along the long side direction of the light emitting region, and the light emitting region of one of the plurality of first solid light sources is defined as the light emitting region of the first solid light source. Each of the long side direction and the short side direction of the shape projected onto the excitation light combining unit has a shape when a light emitting region of one second solid light source among the plurality of second solid light sources is projected onto the excitation light combining unit. It is preferable that the long side direction and the short side direction have a relationship opposite to each other.

  According to this configuration, it is difficult to generate a gap between the region where the first excitation light is incident on the polarization separation film and the region where the second excitation light is incident on the polarization separation film, using the characteristics of the semiconductor laser. Become. Therefore, it is possible to suppress the occurrence of unevenness in the synthetic excitation light.

  In the light source device, the plurality of first solid light sources are arranged in an array, and the first light source unit includes a plurality of first collimator lenses provided corresponding to the plurality of first solid light sources. A first collimator lens array, wherein one of the plurality of first collimator lenses is a first excitation emitted from a first solid light source of the plurality of first solid light sources. The plurality of second solid-state light sources are arranged in an array, and the second light source unit includes a plurality of second collimator lenses provided corresponding to the plurality of second solid-state light sources. A second collimator lens array, wherein one second collimator lens among the plurality of second collimator lenses is a second excitation emitted from one second solid light source among the plurality of second solid light sources. Flat light It is preferable that the reduction.

  According to this configuration, the first excitation light and the second excitation light are incident on the excitation light combining unit in a parallel state. For this reason, it can suppress that excitation light leaks outside compared with the case where each of 1st excitation light and 2nd excitation light injects into the excitation light synthetic | combination part diagonally. Therefore, it becomes possible to synthesize the first excitation light and the second excitation light with high efficiency.

  In the light source device, the plurality of first solid light sources are arranged in a matrix so that a long side direction of a light emitting region of each of the plurality of first solid light sources is parallel to a first direction, and the plurality of first solid light sources One collimator lens is arranged in a matrix corresponding to the arrangement of the plurality of first solid light sources, and the pitch of the plurality of first collimator lenses in the first direction is the plurality of first collimators. The plurality of second solid light sources are shorter than the pitch of the lens in the direction intersecting the first direction, and the long side direction of the light emitting region of each of the plurality of second solid light sources is parallel to the second direction. The plurality of second collimator lenses are arranged in a matrix corresponding to the arrangement of the plurality of second solid-state light sources, and the second collimator lenses of the second collimator lenses are arranged in a matrix. Direction Is preferably less than the pitch in the direction crossing the second direction of the plurality of second collimator lens.

  According to this configuration, the plurality of solid light sources are arranged in an orderly manner in both the first solid light source array and the second solid light source array. For this reason, each solid-state light source array can be reduced in size. Further, in both the collimator lens arrays of the first collimator lens array and the second collimator lens array, a plurality of collimator lenses are regularly arranged in a state corresponding to the light emission characteristics of the semiconductor laser. For this reason, each collimator lens array can be miniaturized. Therefore, it is possible to reduce the size of the light source device.

  In the light source device, the condensing optical system is paired with the lens array, the second lens array on which the partial light bundle enters, and the partial light bundle emitted from the second lens array as the light emitting element. It is preferable that the lens surface of the lens array and the light irradiation surface of the light emitting element are in a conjugate relationship via the condensing optical system.

  According to this configuration, the plurality of partial light beams are favorably superimposed on the light irradiation surface of the light emitting element. Therefore, the light intensity distribution can be easily averaged, and the light amount can be easily controlled so as not to cause light saturation of the light emitting element.

  In the light source device, the planar view shape of the plurality of small lenses constituting the lens array is similar to the planar view shape of the light irradiation surface, and the light intensity distribution of the excitation light that irradiates the light irradiation surface is It is preferable that the light intensity has a continuous light intensity distribution at the same spatial position as the light irradiation surface.

  According to this configuration, since the excitation light can be irradiated to the light emitting element without waste, it is possible to maximize the amount of fluorescence to be extracted with respect to the excitation light amount to be input.

  In the light source device, the light emitting element is provided with a light irradiation surface overlapping with a focal position of the condensing optical system, and an integrated optical system having both ends of the lens array and the condensing optical system includes the light irradiation It is preferable that the plane conjugate with the plane is set at infinity.

  According to this configuration, even if the relative position between the condensing optical system and the lens array is not precisely set, the excitation light to the light emitting element can be generated by setting the relative position between the condensing optical system and the light emitting element. Can be superimposed. Further, since the excitation light is not imaged at the focal position, the image of the excitation light is easy to average the blur light intensity. Therefore, it becomes easy to control the amount of light so as not to cause light saturation in the light emitting element.

  In the light source device, the planar view shape of the plurality of small lenses constituting the lens array is similar to the planar view shape of the light irradiation surface of the light emitting element, and the planar view area of the light irradiation surface of the light emitting element is It is preferable that the size of the exit pupil of the integrated optical system is substantially equal.

  According to this configuration, it is possible to irradiate the light emitting element without waste with excitation light. For this reason, it is possible to maximize the amount of fluorescence to be extracted with respect to the amount of excitation light to be input.

  The light source device includes: a condensing lens that condenses the combined excitation light emitted from the excitation light combining unit; and a parallelizing lens that parallelizes the combined excitation light emitted from the condensing lens. The collimating lens preferably has a concave surface with a quadratic rotational curved surface on either the entrance surface or the exit surface.

  According to this configuration, the parallelism of the excitation light incident on the lens array can be improved. For this reason, the averaging of the excitation light using the lens array and the condensing optical system can be easily controlled as designed, and a decrease in the light emission efficiency can be easily suppressed.

  In the light source device, it is preferable that the collimating lens has the incident surface as the concave surface and the exit surface as a flat surface.

  According to this structure, the parallelism of the excitation light which permeate | transmits a parallelizing lens can be improved more. For this reason, it is easy to average the excitation light using the lens array and the condensing optical system, and it becomes easy to suppress light saturation and cause the light emitting element to emit light.

  In the light source device, it is preferable that the collimating lens is configured such that the incident surface is a spherical convex surface and the exit surface is the concave surface.

  According to this structure, the parallelism of the excitation light which permeate | transmits a parallelizing lens can be improved more. For this reason, it is easy to average the excitation light using the lens array and the condensing optical system, and it becomes easy to suppress light saturation and cause the light emitting element to emit light.

によって表される形状であることが好ましい。 In the light source device, the concave surface is a coordinate value in an rθZ cylindrical coordinate system in which an intersection between the concave surface and the central axis of the light beam is an origin, the central axis is a Z axis, and an axis orthogonal to the central axis is an r axis. Is r and Z, paraxial curvature is c, and conic constant is K.

It is preferable that it is the shape represented by.

  According to this configuration, the shape of the concave surface can be easily determined. In addition, if a lens having an aspheric surface determined based on this equation is used, spherical aberration can be reduced, and the parallelism of light emitted from the light source device can be further improved.

  In the light source device, one of the plurality of first excitation lights may be incident on a region different from a region where the plurality of second excitation lights are incident in the excitation light combining unit. It is preferable to be configured.

  According to this configuration, an excessive thermal load is not applied to the specific region of the excitation light combining unit. Therefore, the lifetime of the excitation light combining unit is not shortened due to the use of the two light source units.

  According to another aspect of the invention, a projector includes: the light source device described above; a light modulation element that modulates light emitted from the light source device; and a projection optical system that projects light modulated by the light modulation element. And

  According to this configuration, since the above-described light source device is provided, it is possible to provide a projector that can further increase the luminance of the display screen without reducing the light use efficiency.

It is a schematic diagram which shows the optical system of the projector which concerns on 1st Embodiment of this invention. It is a front view of the solid light source array with which a light source device is provided. It is a figure which shows the incident area | region of the 1st excitation light and 2nd excitation light in an excitation light synthetic | combination part similarly. It is a side view of an afocal optical system. It is explanatory drawing which shows the behavior of the excitation light which injected into the lens integrator. It is a figure which shows the light intensity distribution of the excitation light which irradiates the light irradiation surface of a light emitting element similarly. It is a schematic explanatory drawing of a polarization conversion element. It is a figure which shows the modification of an afocal optical system similarly. It is a schematic diagram which shows the light source device which concerns on 2nd Embodiment of this invention. It is a front view of the solid light source array with which a light source device is provided. It is a figure which shows the incident area | region of the 1st excitation light and 2nd excitation light in an excitation light synthetic | combination part similarly. It is a schematic diagram which shows the light source device which concerns on 3rd Embodiment of this invention. It is a schematic diagram which shows the light source device which concerns on 4th Embodiment of this invention. It is a schematic diagram which shows the light source device which concerns on 5th Embodiment of this invention. It is a schematic diagram of an excitation light synthesizer. It is a schematic diagram which shows the optical system of the projector which concerns on 6th Embodiment of this invention. It is explanatory drawing which shows the function of a 1st lens array and a superimposition optical system similarly. It is a schematic diagram which shows the optical system of the projector which concerns on 7th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. This embodiment shows one aspect of the present invention, and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, an actual structure and a scale, a number, and the like in each structure are different.

(First embodiment)
An embodiment of a projector according to the present invention will be described with reference to FIGS.
In the present embodiment, an explanation will be given by taking as an example a projection type projector that projects color light including image information generated by a light modulation panel onto a screen (projection surface) via a projection optical system.

  In the following description, an XYZ orthogonal coordinate system is set as necessary, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. In the present embodiment, the direction parallel to the optical axis of the light emitted from the first light source unit 10 is the X direction, and the two directions orthogonal to the X direction are the Y direction and the Z direction.

FIG. 1 is a schematic diagram showing an optical system of a projector 1000 according to the first embodiment of the present invention.
As shown in FIG. 1, the projector 1000 includes an illumination device 100, a color separation light guide optical system 200, a liquid crystal light modulation device 400R as a light modulation device, a liquid crystal light modulation device 400G, a liquid crystal light modulation device 400B, A dichroic prism 500 and a projection optical system 600 are provided.

  The illumination device 100 includes a light source device 1, a first lens array 120, a second lens array 130, a polarization conversion element 140, and a superimposing lens 150. The lighting device 100 emits white light including red light, green light, and blue light.

As illustrated in FIG. 1, the light source device 1 includes a first light source unit 10, a second light source unit 20, an excitation light synthesis unit 30, an afocal optical system 40, a lens integrator 50, and a dichroic mirror 60. An optical system 70 and a light emitting element 80 are provided.
Here, the second lens array 52 included in the lens integrator 50 and the superimposing optical system 70 constitute a condensing optical system in the present invention.

  The first light source unit 10 includes a first solid light source array 11 and a first collimator lens array 14. The second light source unit 20 includes a second solid light source array 21 and a second collimator lens array 24.

  FIG. 2 is a front view of the solid light source array (the first solid light source array 11 and the second solid light source array 21) included in the light source device 1. FIG. 2A is a view (hereinafter, referred to as a front view) of the first solid-state light source array 11 viewed from the excitation light combining unit 30 side, and FIG. 2B is a front view of the second solid-state light source array 21. .

  As shown in FIG. 2A, the first solid light source array 11 includes a substrate 12 and 20 first solid light sources 13 that emit blue light as excitation light. In the first solid light source array 11, 20 first solid light sources 13 are arranged in a matrix of 5 rows and 4 columns.

In the light source device 1 of the present invention, the number of the first solid light sources 13 is not limited to 20, but may be two or more.
The substrate 12 has a function of mounting the first solid light source 13. For example, the substrate 12 has a function of mediating supply of electric power to the first solid light source 13, a function of radiating heat generated by the first solid light source 13, and the like.

  The first solid-state light source 13 is composed of a semiconductor laser that emits blue light (emission intensity peak: about 460 nm) as excitation light. As shown in FIG. 2A, the semiconductor laser has a rectangular light-emitting region, and the light divergence angle along the short side direction of the light-emitting region is the light divergence angle along the long-side direction of the light-emitting region. It is comprised so that it may become larger than a divergence angle. The size of the light emitting region in the semiconductor laser is, for example, a long side VL of 8 μm and a short side VS of 2 μm.

  The first solid light source 13 emits blue light composed of P-polarized light with respect to the incident surface of the excitation light combining unit 30.

  In addition, as a structure in which the excitation light from the 1st light source part 10 injects into the excitation light synthetic | combination part 30 as excitation light which consists of P polarized light, it is restricted to the structure using the solid light source which inject | emits the excitation light which consists of P polarization as mentioned above. Absent. For example, a solid light source that emits excitation light composed of S-polarized light with respect to the incident surface of the excitation light combining unit 30 and a λ / 2 plate may be used.

  The first collimator lens array 14 is provided corresponding to the plurality of first solid light sources 13 and includes 20 first collimator lenses 15. Although not illustrated, the plurality of first collimator lenses 15 are arranged in a matrix of 5 rows and 4 columns. One first collimator lens 15 substantially parallelizes the blue light emitted from one first solid light source 13 among the plurality of first solid light sources 13. The first collimator lens 15 is a plano-convex lens.

  The first collimator lens array 14 is arranged so that the planes of the plurality of first collimator lenses 15 face the first solid-state light source array 11 side.

  The first collimator lens array 14 may be arranged so that the convex surfaces of the plurality of first collimator lenses 15 face the first solid-state light source array 11 side.

  As shown in FIG. 2B, the second solid light source array 21 includes a substrate 22 and 25 second solid light sources 23 that emit blue light as excitation light. In the second solid light source array 21, 25 second solid light sources 23 are arranged in a matrix of 5 rows and 5 columns.

In the light source device 1 of the present invention, the number of the second solid light sources 23 is not limited to 25 and may be two or more.
The substrate 22 has a function of mounting the second solid light source 23. For example, the substrate 22 has a function of mediating supply of power to the second solid light source 23, a function of radiating heat generated by the second solid light source 23, and the like.

  The second solid-state light source 23 is composed of a semiconductor laser that emits blue light (emission intensity peak: about 460 nm) as excitation light. As shown in FIG. 2B, the semiconductor laser has a rectangular light-emitting region, and the light divergence angle along the short side direction of the light-emitting region is the light spread angle along the long-side direction of the light-emitting region. It is comprised so that it may become larger than a divergence angle. The size of the light emitting region in the semiconductor laser is, for example, a long side VL of 8 μm and a short side VS of 2 μm.

  The second solid light source 23 emits blue light composed of S-polarized light with respect to the incident surface of the excitation light combining unit 30.

  Note that the configuration in which the excitation light from the second light source unit 20 enters the excitation light combining unit 30 as excitation light composed of S-polarized light is not limited to the configuration using a solid light source that emits excitation light composed of S-polarized light as described above. Absent. For example, a solid light source that emits excitation light composed of P-polarized light on the incident surface of the excitation light combining unit 30 and a λ / 2 plate may be used.

  The second collimator lens array 24 is provided corresponding to the plurality of second solid light sources 23, and each of the 25 second collimator lenses substantially parallelizes the blue light emitted from the plurality of second solid light sources 23. 25. Although not illustrated, the plurality of second collimator lenses 25 are arranged in a matrix of 5 rows and 5 columns. One second collimator lens 25 substantially parallelizes the blue light emitted from one second solid light source 23 among the plurality of second solid light sources 23. The second collimator lens 25 is a plano-convex lens.

  The second collimator lens array 24 is arranged so that the plane of the plurality of second collimator lenses 25 faces the second solid light source array 21 side.

  The second collimator lens array 24 may be arranged such that the convex surfaces of the plurality of second collimator lenses 25 face the second solid light source array 21 side.

  In the light source device 1 according to the present embodiment, as shown in FIGS. 2A and 2B, the light emission region of one first solid light source 13 among the plurality of first solid light sources 13 is used as an excitation light combining unit. Each of the long side direction and the short side direction of the shape when projected onto 30 is the length of the shape when the light emitting region of one second solid light source 23 among the plurality of second solid light sources 23 is projected onto the excitation light combining unit 30. The side direction and the short side direction are opposite to each other. More specifically, when the light emitting region of the first solid-state light source 13 is projected onto the excitation light combining unit 30, the long side direction of the light emitting region is the Z-axis direction, and the short side direction of the light emitting region is the Y-axis direction. On the other hand, when the light emitting region of the second solid-state light source 23 is projected onto the excitation light combining unit 30, the long side direction of the light emitting region is the Y axis direction, and the short side direction of the light emitting region is the Z axis direction. Thus, each of the shape when the light emitting region of the first solid light source 13 is projected onto the excitation light combining unit 30 and the shape when the light emitting region of the second solid light source 23 is projected onto the excitation light combining unit 30 are in the long side direction. And the direction of the short side are opposite to each other. The substrate 12 has a rectangular shape when viewed from the front, and the substrate 22 has a square shape when viewed from the front. The size of the substrate 12 is smaller than the size of the substrate 22.

  As shown in FIGS. 1, 2A, 2B, and 3, the first light source unit 10 and the second light source unit 20 are optical axes of blue light synthesized by an excitation light synthesis unit 30 described later. The blue light (first excitation light) from the first light source unit 10 and the blue light (second excitation light) from the second light source unit 20 are arranged so as to deviate from each other on a plane perpendicular to the first light source unit 10.

  As described above, in the first solid-state light source array 11 according to the present embodiment, the plurality of first solid-state light sources 13 are arranged in a matrix along the long-side direction and the short-side direction of each light-emitting region. The long side direction in the first solid-state light source array 11 is defined as a first direction. In the second solid-state light source array 21, the plurality of second solid-state light sources 23 are arranged in a matrix along the long side direction and the short side direction of each light emitting region. The long side direction in the second solid-state light source array 21 is defined as a second direction.

  In the first collimator lens array 14, a plurality of first collimator lenses 15 correspond to the arrangement of the plurality of first solid light sources 13, and a direction intersecting the first direction, Are arranged in a matrix. The pitch PS of the plurality of first collimator lenses 15 in the first direction is shorter than the pitch PL of the plurality of first collimator lenses 15 in the direction intersecting the first direction.

  Similarly, in the second collimator lens array 24, the plurality of second collimator lenses 25 intersect the second direction and the second direction corresponding to the arrangement of the plurality of second solid light sources 23. Are arranged in a matrix along the direction. The pitch PS of the plurality of second collimator lenses 25 in the second direction is shorter than the pitch PL of the plurality of second collimator lenses 25 in the direction intersecting with the second direction.

  Hereinafter, a long pitch direction having a relatively long lens pitch is defined as a long pitch direction, and a short pitch direction having a relatively short lens pitch is defined as a short pitch direction.

  The excitation light combining unit 30 transmits a plurality of blue lights (first excitation light) from the first light source unit 10 and reflects a plurality of blue lights (second excitation light) from the second light source unit 20, The plurality of blue lights from the first light source unit 10 and the plurality of blue lights from the second light source unit 20 are combined. The excitation light combining unit 30 combines the plurality of blue lights from the first light source unit 10 and the plurality of blue lights from the second light source unit 20 and emits them as combined excitation light. The excitation light combining unit 30 has a polarization separation film that passes light composed of P-polarized light and reflects light composed of S-polarized light. The excitation light combining unit 30 is arranged so that the angle between the optical axis 10ax of the afocal optical system 40 and the excitation light combining surface forms a predetermined angle (for example, about 45 degrees).

  FIG. 3 is a diagram illustrating incident areas of the first excitation light and the second excitation light in the excitation light synthesis unit 30. In FIG. 3, a portion surrounded by a solid line is an incident region for the first excitation light, and a portion surrounded by a broken line is an incident region for the second excitation light.

  As shown in FIG. 3, in the present embodiment, each of the first excitation light emitted from the first light source unit 10 and the second excitation light emitted from the second light source unit 20 is converted into the excitation light combining unit 30. In FIG. 2, the light is incident on different regions. The incident areas of the first excitation light are distributed in a matrix of 5 rows and 4 columns, and the incident areas of the second excitation light are distributed in a matrix of 5 rows and 5 columns. As a result, a 5 × 9 matrix intensity distribution is obtained.

FIG. 4 is a side view of the afocal optical system 40.
As shown in FIG. 4, the afocal optical system 40 includes a condenser lens 41 and a collimating lens 42, which are arranged in this order on the optical path. The combined excitation light emitted from the excitation light combining unit 30 is collected by the condenser lens 41. Thereafter, the combined excitation light collected by the condenser lens 41 is collimated by the collimating lens 42. By transmitting through such an afocal optical system 40, the width of the entire beam bundle of the synthetic excitation light is narrowed.

  Here, the collimating lens 42 is a single-concave lens in which the incident surface 42a is an aspheric concave surface and the exit surface 42b is a flat surface. The shape of the incident surface 42a will be described more specifically. The aspherical shape of the incident surface 42a of the collimating lens 42 is a shape that substantially satisfies the relationship of the following formula (2). That is, on the incident surface 42a, it is possible to emit light with a high degree of parallelism by changing the aspherical shape of the incident surface 42a to a rotating quadratic curved surface shape.

  Here, as shown in FIG. 4, r and Z are the intersections of the incident surface 42a of the collimating lens 42 and the central axis 10ax of the ray bundle of the synthetic excitation light, with the origin L0, and rθZ that is the object of the axis about the central axis 10ax. It is a coordinate value in a cylindrical coordinate system. In FIG. 4, in the Z direction, the emission direction of the excitation light is positive. r indicates the distance from the origin L0 in the direction orthogonal to the central axis 10ax. θ represents an angle from a predetermined r direction, but as can be seen from Equation (2), the shape of the aspheric surface does not depend on the angle θ.

  Further, in equation (2), the paraxial curvature c is the spherical surface when it is assumed that the light beam of the combined excitation light collected by the condenser lens 41 is converted into parallel light using a spherical plano-concave lens. Shows the curvature. In other words, in the paraxial region (region near the rotation axis), by using a plano-concave lens having this curvature c, the light beam of the combined excitation light collected by the condenser lens 41 can be converted into parallel light. Become.

  K is a value called a conic constant. Depending on the value of the conic constant K, the rotational quadric surface shape is limited to a specific shape. That is, when the value of the conic constant K is -1 <K <0, the aspherical surface is a spheroidal surface. Further, when the value of the conic constant K is K = −1, the aspheric surface is a paraboloid of revolution. Furthermore, when the value of the conic constant K is K <−1, the aspherical surface is a rotating hyperboloid.

  Further, the third term on the left side is a function that depends on the distance r called a general aspheric term, but is a sufficiently small value and is ignored in this embodiment.

  The aspheric rotational quadric surface shape of the collimating lens 42 in this embodiment is determined by the following method based on the following equation (3) ignoring the third term on the left side of equation (2).

  First, the shape of the condenser lens 41, the curvature of the incident surface 42a of the collimating lens 42, the refractive index n of the collimating lens 42, the thickness of the central portion of the collimating lens 42, and the installation position of the collimating lens 42 And the value of the paraxial curvature c is obtained.

  Specifically, first, the shape of the condenser lens 41, the curvature of the incident surface 42a of the collimating lens 42, the refractive index n, the thickness of the central portion, and the installation position are determined in advance. Further, instead of the collimating lens 42, it is assumed that the entrance surface has the same curvature, refractive index, and central thickness, and has a spherical exit surface. Then, when the concave lens is arranged at the installation position of the collimating lens 42 with respect to the condensing lens having the same shape as the predetermined shape, the curvature of the entrance surface of the concave lens that can be converted into parallel light if there is no spherical aberration Ask for. The value of the curvature thus obtained is the paraxial curvature c.

Next, the conic constant K is obtained. Here, in the collimating lens 42, the incident surface 42a is an aspherical surface set based on the equation (3). For this reason, the excitation light incident on the collimating lens 42 is changed in a traveling direction to a substantially parallel direction by refraction at the incident surface 42a, and hardly receives a refracting action at the exit surface 42b. As a result, the relationship between the refractive index n of the collimating lens 42 and the conical constant K is constant. Note that the conic constant K of the aspherical surface of the reflecting surface of the collimating lens 42 is determined by approximately K = −n ² .

Therefore, in this embodiment, the conic constant K can be obtained by K = −n ² . The conic constant K of the aspherical surface of the collimating lens 42 is in a range of −2.1 <K <−3.8. Therefore, when the incident surface 42a is aspherical, the incident surface 42a is preferably a rotational hyperboloid.

  When the collimating lens 42 designed in this way is used, the excitation light transmitted through the afocal optical system 40 can be made light with high parallelism.

  The combined excitation light transmitted through the afocal optical system 40 enters the lens integrator 50. The lens integrator 50 includes a first lens array 51 and a second lens array 52, which are arranged in this order on the optical path. The first lens array 51 and the second lens array 52 make the luminance distribution of the light emitted from the afocal optical system 40 uniform.

  The excitation light that has passed through the lens integrator 50 enters the dichroic mirror 60. The dichroic mirror 60 is configured, for example, by laminating a dielectric multilayer film on a glass surface.

  The dichroic mirror 60 has wavelength selectivity that selectively reflects colored light in the wavelength band of excitation light and transmits colored light in other wavelength bands. Specifically, the dichroic mirror 60 reflects blue light and transmits light having a longer wavelength than blue light (for example, light having a longer wavelength than 480 nm).

  The excitation light reflected by the dichroic mirror 60 enters the superimposing optical system 70 and forms an image on the light emitting element 80.

  FIG. 5 is an explanatory diagram showing the behavior of excitation light until the light emitting element 80 is irradiated with excitation light (blue light) incident on the lens integrator 50.

  As shown in FIG. 5, the first lens array 51 includes a plurality of first small lenses 51a, and the second lens array 52 includes a plurality of second small lenses 52a. The planar view shapes of the first small lens 51 a and the second small lens 52 a are substantially similar to the planar view shape of the light irradiation surface 80 a of the light emitting element 80.

  In FIG. 5, only the portion corresponding to the excitation light irradiation region 80 a of the light emitting element 80 is shown for convenience. The excitation light irradiation region 80a in the phosphor layer 82 has, for example, a substantially square shape of 1 mm × 1 mm in plan view.

  In the first lens array 51 and the second lens array 52, the first small lens 51a and the second small lens 52a have a one-to-one correspondence. The light emitted from the afocal optical system 40 is spatially divided and incident on the plurality of first small lenses 51a, and the first small lenses 51a image the incident light on the corresponding second small lenses 52a. . Thereby, a secondary light source image is formed on each of the plurality of second small lenses 52a.

  The light emitted from each of the plurality of second small lenses 52 a is collected by the superimposing optical system 70 via the dichroic mirror 60 and forms an image on the light emitting element 80. In other words, the condensing optical system including the second lens array 52 and the superimposing optical system 70 forms an image of the incident light on the light irradiation surface 80 a of the corresponding light emitting element 80.

  The superimposing optical system 70 includes a first lens 71 and a second lens 72. The first lens 71 and the second lens 72 are biconvex lenses. The shapes of the first lens 71 and the second lens 72 are not limited to the above shapes. In short, it is only necessary that the superimposing optical system including the first lens 71 and the second lens 72 can collect the excitation light reflected by the dichroic mirror 60 at a predetermined condensing position. Further, the number of lenses constituting the superimposing optical system 70 may be one, or may be three or more.

  In such an arrangement, in the optical system including the second lens array 52 and the superimposing optical system 70, the lens surface of the first lens array 51 and the light irradiation surface 80a of the light emitting element 80 are in a conjugate relationship. It is good to be configured. In other words, the object surface of the optical system configured to include the second lens array 52 and the superimposing optical system 70 is configured to match the lens surface of the first lens array 51, and the image surface matches the light irradiation surface 80a. It is good to be. As a result, the light irradiation surface 80a is irradiated with excitation light whose intensity distribution is averaged.

Here, the “lens surface of the first lens array 51” is a virtual surface that connects valleys between the plurality of first small lenses 51 a included in the first lens array 51.

  Returning to FIG. 1, the light emitting element 80 is a so-called reflection-type rotating fluorescent plate that emits fluorescence to the same side as the side on which excitation light is incident. The light emitting element 80 is formed by forming a phosphor layer 82 around a rotation axis of the rotating plate 81 on a rotating plate 81 that is rotationally driven by a motor 83. The phosphor layer 82 includes phosphor particles 82a (see FIG. 5) and a binder.

  Excitation light (blue light) collected by the first lens 71 and the second lens 72 enters the light emitting element 80 from the surface of the phosphor layer 82. The light emitting element 80 emits the fluorescence emitted from the phosphor layer 82 toward the same side as the side where the excitation light is incident. Fluorescence includes red light and green light.

  The rotating plate 81 rotates at 7500 rpm during use. The diameter of the rotating plate 81 is 50 mm, and the condensing spot of the blue light incident on the phosphor layer 82 is configured to be located about 22.5 mm away from the rotation center of the rotating plate 81. That is, the rotating plate 81 moves so that the blue light condensing spot draws a circle around the rotation axis at a speed of about 18 m / sec.

  The rotating plate 81 is made of a material that reflects the fluorescence emitted from the phosphor layer 82. As a material of the rotating plate 81, for example, a metal material having a high thermal conductivity such as Al can be used.

  The phosphor layer 82 includes phosphor particles 82a that emit fluorescence, and has a function of absorbing excitation light (blue light) and converting it to fluorescence of approximately 490 to 750 nm (peak of emission intensity: 570 nm). This fluorescence includes green light (wavelength near 530 nm) and red light (wavelength near 630 nm).

  The phosphor particles 82a are particulate fluorescent materials that absorb excitation light emitted from the first light source unit 10 and the second light source unit 20 shown in FIG. 1 and emit fluorescence. For example, the phosphor particle 82a contains a substance that emits fluorescence when excited by blue light having a wavelength of about 460 nm, and a part of the excitation light is converted into light including from the red wavelength band to the green wavelength band. Convert and inject.

As the phosphor particles 82a, a commonly known YAG (yttrium, aluminum, garnet) phosphor can be used. For example, a YAG phosphor having a composition represented by (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce having an average particle diameter of 10 μm can be used. The phosphor particle forming material may be one kind, or a mixture of particles formed using two or more kinds of forming materials may be used as the phosphor particles.

  FIG. 6 is a diagram illustrating a light intensity distribution of excitation light that irradiates the light irradiation surface 80 a of the light emitting element 80. In FIG. 6, the horizontal axis represents the irradiation position, and the vertical axis represents the intensity (irradiance) of the excitation light.

  As shown in FIG. 3, at the spatial position before entering the first lens array 51, the light intensity distribution of the excitation light is in an arrangement state of a plurality of solid light sources in the first light source unit 10 and the second light source unit 20. Correspondingly, there are discretely bright and dark portions. On the other hand, after passing through the superimposing optical system 70, the excitation light is shaped into a substantially square shape of 1 mm × 1 mm at a spatial position before entering the light irradiation surface 80a. As a result, the excitation light has substantially the same light intensity in all regions of the light irradiation surface 80a, and as shown in FIG. 6, it becomes a continuous light intensity distribution approaching a so-called top hat-shaped light intensity distribution. . In FIG. 6, the region SA where the light intensity distribution of the excitation light is substantially uniform has a size corresponding to the light irradiation surface 80a.

  As described above, the light emitting element 80 is irradiated with excitation light having a light intensity distribution that is more uniform than before the light transmitted through the lens integrator 50. Further, the excitation light to be irradiated is formed in substantially the same shape as the planar view shape of the light irradiation surface 80 a of the light emitting element 80. Therefore, it becomes easy to irradiate the light emitting element 80 with excitation light having a substantially uniform light intensity distribution over the entire surface of the light irradiation surface 80a so that fluorescence light saturation does not occur in the light irradiation surface 80a. Therefore, the light emitting element 80 can be used as a secondary light source that emits fluorescence RG satisfactorily from the entire surface of the light irradiation surface 80a.

  For the fluorescence RG emitted from the light emitting element 80, the superimposing optical system 70 functions as a pickup optical system. Therefore, the fluorescence RG enters the dichroic mirror 60 after being collimated by the superimposing optical system 70. Thereafter, the fluorescent RG passes through the dichroic mirror 60 and is emitted toward the lens array 120.

  Note that blue light emitted from another light source device (not shown) is incident on the surface of the dichroic mirror 60 opposite to the incident surface on which light from the superimposing optical system 70 is incident. Are reflected in a direction parallel to the light axis (toward the lens array 120).

  That is, the light emitted from the dichroic mirror 640 is white light in which the fluorescent light RG in which red light and green light emitted from the light emitting element 80 are mixed and the blue light B emitted from another light source device is mixed. L.

  As shown in FIG. 1, the first lens array 120 includes a plurality of first small lenses 122 for dividing the light from the light source device 10 into a plurality of partial light beams. The first lens array 120 has a function as a beam splitting optical element that splits the light from the light source device 1 into a plurality of partial beams, and the plurality of first small lenses 122 are in a plane orthogonal to the illumination optical axis 100ax. It has a configuration arranged in a matrix of multiple rows and multiple columns. Although not illustrated, the outer shape of the first small lens 122 is substantially similar to the outer shape of the image forming regions of the liquid crystal light modulation devices 400R, 400G, and 400B.

  The second lens array 130 has a plurality of second small lenses 132 corresponding to the plurality of first small lenses 122 of the first lens array 120. The second lens array 130 has a function of forming an image of each first small lens 122 of the first lens array 120 in the vicinity of the image forming region of the liquid crystal light modulators 400R, 400G, and 400B together with the superimposing lens 150. The second lens array 130 has a configuration in which a plurality of second small lenses 132 are arranged in a matrix of a plurality of rows and a plurality of columns in a plane orthogonal to the illumination optical axis 100ax.

  The polarization conversion element 140 aligns the polarization state of the light L emitted from the lens arrays 120 and 130. As shown in FIG. 7, the polarization conversion element 140 includes a plurality of polarization conversion cells 141. The polarization conversion cell 141 has a one-to-one correspondence with the second small lens 132. The light L from the secondary light source image formed on the second small lens 132 enters the incident region 142 of the polarization conversion cell 141 corresponding to the second small lens 132.

  Each polarization conversion cell 141 is provided with a polarization beam splitter film 143 (hereinafter referred to as a PBS film 143) and a phase difference plate 145 corresponding to the incident region 142. The light L incident on the incident region 142 is separated by the PBS film 143 into P-polarized light L1 and S-polarized light L2 with respect to the PBS film 143. One of the P-polarized light L1 and the S-polarized light L2 (here, S-polarized light L2) is reflected by the reflecting member 144 and then enters the phase difference plate 145. The S-polarized light L2 that has entered the phase difference plate 145 is converted into the polarization state of the other polarization (here, P-polarized light L1) by the phase difference plate 145, becomes P-polarized light L3, and is emitted together with the P-polarized light L1. .

  The superimposing lens 150 superimposes the light emitted from the polarization conversion element 140 in the illuminated area. The light emitted from the light source device 100 is spatially divided and then superimposed, whereby the luminance distribution is made uniform and the axial symmetry around the light axis 100ax is enhanced.

  The superimposing lens 150 is an optical element for condensing the partial light flux and superimposing it on the vicinity of the image forming area of the liquid crystal light modulation devices 400R, 400G, and 400B. The superimposing lens 150 is arranged so that the optical axis of the superimposing lens 150 and the optical axis of the illumination device 100 substantially coincide with each other.

  The superimposing lens 150 may be composed of a compound lens in which a plurality of lenses are combined.

  With such a configuration, the first lens array 120, the second lens array 130, and the superimposing lens 150 serve as a lens integrator optical system and make light from the light source device 1 more uniform.

  Note that a rod integrator optical system including an integrator rod can be used instead of the lens integrator optical system.

  The color separation light guide optical system 200 includes dichroic mirrors 210 and 220, reflection mirrors 230, 240 and 250, and relay lenses 260 and 270. The color separation light guide optical system 200 separates the light from the illumination device 100 into red light, green light, and blue light, and the respective color lights of red light, green light, and blue light are liquid crystal light modulation devices 400R that are illumination targets. , 400G, 400B.

  Condensing lenses 300R, 300G, and 300B are disposed between the color separation light guide optical system 200 and the liquid crystal light modulation devices 400R, 400G, and 400B.

  The dichroic mirrors 210 and 220 are mirrors in which a wavelength selective transmission film that reflects light in a predetermined wavelength region and passes light in other wavelength regions is formed on a substrate. The dichroic mirror 210 is a dichroic mirror that reflects a red light component and transmits green light and blue light components. The dichroic mirror 220 is a dichroic mirror that reflects a green light component and transmits a blue light component. The reflection mirror 230 is a reflection mirror that reflects a red light component. The reflection mirrors 240 and 250 are reflection mirrors that reflect blue light components.

  The red light reflected by the dichroic mirror 210 is reflected by the reflection mirror 230, passes through the condenser lens 300R, and enters the image forming region of the liquid crystal light modulation device 400R for red light.

  The green light that has passed through the dichroic mirror 210 is reflected by the dichroic mirror 220, passes through the condenser lens 300G, and enters the image forming area of the liquid crystal light modulation device 400G for green light.

  The blue light that has passed through the dichroic mirror 220 passes through the relay lens 260, the incident-side reflecting mirror 240, the relay lens 270, the exit-side reflecting mirror 250, and the condensing lens 300B to form an image of the liquid crystal light modulation device 400B for blue light. Incident into the area. The relay lenses 260 and 270 and the reflection mirrors 240 and 250 have a function of guiding the blue light component transmitted through the dichroic mirror 220 to the liquid crystal light modulation device 400B.

  The reason why such a relay lens 260, 270 is provided in the optical path of blue light is that the length of the optical path of blue light is longer than the length of the optical path of other color light, This is to prevent a decrease in usage efficiency. The projector 1000 according to the first embodiment has such a configuration because the length of the optical path of blue light is long. However, the length of the optical path of red light is increased, and the relay lenses 260 and 270 and the reflection mirror are configured. A configuration using 240 and 250 in the optical path of red light is also conceivable.

  The liquid crystal light modulation devices 400R, 400G, and 400B form color images by modulating incident color light according to image information, and are illumination targets of the illumination device 100.

  Although not shown, incident-side polarizing plates are disposed between the condenser lenses 300R, 300G, and 300B and the liquid crystal light modulators 400R, 400G, and 400B, respectively. Further, an exit-side polarizing plate is disposed between each of the liquid crystal light modulation devices 400R, 400G, and 400B and the cross dichroic prism 500. The incident-side polarizing plates, the liquid crystal light modulation devices 400R, 400G, and 400B and the exit-side polarizing plate modulate the light of each incident color light.

  The liquid crystal light modulators 400R, 400G, and 400B are transmissive liquid crystal light modulators in which a liquid crystal that is an electro-optical material is hermetically sealed in a pair of transparent glass substrates. In accordance with the received image signal, the polarization direction of one type of linearly polarized light emitted from the incident side polarizing plate is modulated.

  The cross dichroic prism 500 is an optical element that forms a color image by synthesizing an optical image modulated for each color light emitted from the emission side polarizing plate. The cross dichroic prism 500 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and a dielectric multilayer film is formed on a substantially X-shaped interface in which the right-angle prisms are bonded together. The dielectric multilayer film formed at one of the substantially X-shaped interfaces reflects red light, and the dielectric multilayer film formed at the other interface reflects blue light. By these dielectric multilayer films, the red light and the blue light are bent and aligned with the traveling direction of the green light, so that the three color lights are synthesized.

  The color image emitted from the cross dichroic prism 500 is enlarged and projected by the projection optical system 600 to form an image on the screen SCR.

  According to the light source device 1 of the present embodiment, fluorescence is emitted using excitation light emitted from two light source units (first light source unit 10 and second light source unit 20) including a plurality of solid light sources. For this reason, the brightness | luminance of the light source device 1 can be made still higher.

  In addition, the excitation light from the two light source units is synthesized using the excitation light synthesis unit 30 and then condensed on the light emitting element 80. For this reason, compared with the case where the excitation light from two light source parts is synthesize | combined without using the excitation light synthetic | combination part 30 which concerns on this invention, it is a smaller incident angle with respect to the light emitting element 80, and a smaller light emitting element. It becomes possible to make excitation light enter the region. That is, the increase in etendue can be reduced. Also in this sense, it is possible to reduce the decrease in the use efficiency of the fluorescent light caused by using the two light source units.

  In addition, the excitation light from the two light source units emits light through the first lens array 51 and the condensing optical system (the condensing optical system including the second lens array 52 and the superimposing optical system 70). The light intensity distribution is averaged by superimposing on the element 80. Therefore, it becomes possible to irradiate the entire light emitting element 80 with excitation light with uniform light intensity. This makes it easy to control the amount of light so as not to cause light saturation in the region irradiated with excitation light.

  Therefore, the luminance of the light source device 1 can be further increased without reducing the utilization efficiency of the excitation light.

  Further, according to this configuration, each of the first excitation light and the second excitation light is configured to be incident on different regions in the excitation light combining unit 30. For this reason, an excessive thermal load is not applied to the specific region of the excitation light combining unit 30. Therefore, the lifetime of the excitation light combining unit 30 is not shortened due to the use of the two light source units.

  Further, according to this configuration, the excitation light combining unit 30 has the polarization separation film that transmits the light composed of P-polarized light and reflects the light composed of S-polarized light. In addition, a plurality of first excitation lights emitted from the first light source unit 10 enter the excitation light combining unit 30 as excitation light composed of P-polarized light, and a plurality of second excitation lights emitted from the second light source unit 20. Is configured to be incident on the excitation light combining unit 30 as excitation light composed of S-polarized light. Therefore, it is possible to synthesize the first excitation light and the second excitation light with high efficiency using the principle of the polarization separation film.

  Moreover, according to this structure, both the solid light sources of the 1st solid light source 13 and the 2nd solid light source 23 consist of semiconductor lasers. Since the semiconductor laser is small and has a high output, the light source device 1 having a small size and a light output can be obtained by adopting the above configuration.

  Further, according to this configuration, the semiconductor laser has a rectangular light emitting region in plan view. Further, the divergence angle along the short side direction of the light emitting region is configured to be larger than the divergence angle along the long side direction of the light emitting region. Furthermore, as described above, the light emitting region of the first solid light source 13 and the light emitting region of the second solid light source 23 have a relationship in which the long side direction and the short side direction are opposite to each other. For this reason, it is difficult to generate a gap between the region where the first excitation light is incident on the polarization separation film 32 and the region where the second excitation light is incident on the polarization separation film 32 by utilizing the characteristics of the semiconductor laser. . Therefore, it is possible to suppress the occurrence of unevenness in the synthetic excitation light.

  In the case where the excitation light combining unit 30 includes the polarization separation film 32 that transmits the light composed of P-polarized light and reflects the light composed of S-polarized light, it is not necessary to separately provide a retardation plate.

  Furthermore, in the case where each of the first excitation light and the second excitation light is configured to be incident on a region partially overlapping each other in the excitation light combining unit 30, the first excitation light in the polarization separation film 32. And the incident area | region of 2nd excitation light can be narrowed. Therefore, the apparatus can be reduced in size.

  Further, according to this configuration, the first light source unit 10 includes the first solid light source array 11 and the first collimator lens array 14, and the second light source unit 20 includes the second solid light source array 21 and the second solid light source array 21. A collimator lens array 24. As a result, the first excitation light and the second excitation light are incident on the excitation light combining unit 30 in a parallel state. For this reason, it is possible to suppress the leakage of the excitation light to the outside as compared with the case where the first excitation light and the second excitation light are incident on the excitation light combining unit 30 in a state where they are not parallelized. Therefore, it becomes possible to synthesize the first excitation light and the second excitation light with high efficiency.

  Further, according to this configuration, the plurality of first solid light sources 13 and the plurality of second solid light sources 23 are arranged in a matrix in the first solid light source array 11 and the second solid light source array 21. In the first collimator lens array 14 and the second collimator lens array 24, a plurality of first collimator lenses 15 and a plurality of second collimator lenses 25 are respectively arranged in a matrix. Further, the light emitting area of the first collimator lens 15 and the first solid-state light source 13 has a relationship in which the long pitch direction of the lens pitch corresponds to the short side direction of the light emitting area, and the short pitch direction of the lens pitch. And the long side direction of the light emitting region have a corresponding relationship. The light emitting area of the second collimator lens 25 and the second solid state light source 23 has a relationship in which the long pitch direction of the lens pitch corresponds to the short side direction of the light emitting area, and the short pitch direction of the lens pitch. And the long side direction of the light emitting region have a corresponding relationship. As a result, a plurality of solid light sources are arranged in an orderly manner in both the first solid light source array 11 and the second solid light source array 21. For this reason, size reduction of the 1st solid light source array 11 and the 2nd solid light source array 21 can be achieved. Further, in both the collimator lens arrays of the first collimator lens array 14 and the second collimator lens array 24, a plurality of collimator lenses are regularly arranged in a state corresponding to the light emission characteristics of the semiconductor laser. Therefore, the collimator lens arrays 14 and 24 can be downsized. Therefore, the light source device 1 can be downsized.

  Further, according to this configuration, the condensing optical system is configured by the second lens array 52 and the superimposing optical system 70, and the lens surface of the first lens array 51 and the light irradiation surface 80a of the light emitting element 80 are collected. There is a conjugate relationship through the optical optical system. Thereby, a plurality of partial light bundles are favorably superimposed on the light irradiation surface 80 a of the light emitting element 80. Therefore, it is easy to average the light intensity distribution, and it becomes easy to control the light amount so as not to cause light saturation of the light emitting element 80.

  Further, according to this configuration, the planar view shape of the plurality of small lenses 51a constituting the first lens array 51 is similar to the planar view shape of the light irradiation surface 80a. Further, the light intensity distribution of the excitation light that irradiates the light irradiation surface 80a is a continuous light intensity distribution in which the light intensity is substantially uniform at the same spatial position as the light irradiation surface 80a. For this reason, since the excitation light can be irradiated to the light emitting element 80 without waste, the amount of fluorescence taken out with respect to the excitation light amount to be input can be maximized.

  Further, according to this configuration, the collimating lens 42 has a concave surface having a rotating quadratic curved surface on the incident surface 42a. Thereby, the parallelism of the excitation light incident on the first lens array 51 can be improved. For this reason, it is easy to control the averaging of excitation light using the first lens array 51 and the condensing optical system as designed, and it is possible to easily suppress a decrease in light emission efficiency.

  Further, according to this configuration, the collimating lens 42 has the incident surface 42a as a concave surface and the exit surface 42b as a flat surface. Thereby, the parallelism of the excitation light which permeate | transmits the parallelizing lens 42 can be improved more. For this reason, it is easy to average the excitation light using the first lens array 51 and the condensing optical system, and it is easy to suppress light saturation and cause the light emitting element to emit light.

  Moreover, according to this structure, a concave surface is determined by said Formula (3). For this reason, the shape of a concave surface can be determined easily. Further, if a lens having an aspherical surface determined based on the above equation (3) is used, spherical aberration can be reduced, so that the parallelism of light emitted from the light source device 1 can be further improved. it can.

  According to the projector 1000 of the present embodiment, since the light source device 1 described above is included, it is possible to provide the projector 1000 that can further increase the brightness of the display screen without reducing the light use efficiency.

  In the present embodiment, the collimating lens 42 has an aspherical shape on the incident surface 42a, but a lens having an aspherical shape on the exit surface side may be used.

FIG. 8 is a diagram showing a modification of the afocal optical system according to the present embodiment.
As shown in FIG. 8, an afocal optical system 40A according to this modification has a condensing lens 43 and a collimating lens 44, which are arranged in this order on the optical path.

  In the collimating lens 44 according to this modification, the exit surface 44b has a rotating quadratic curved surface shape that satisfies the relationship of the above formula (3), and the entrance surface 44a is a spherical convex surface. The shape of the aspheric rotating quadric surface of the collimating lens 44 is determined by the following method based on the above equation (3).

  Specifically, first, the shape of the condenser lens 43, the curvature of the incident surface 44a of the collimating lens 44, the refractive index n, the thickness of the central portion, and the installation position are determined in advance. Further, instead of the collimating lens 44, a concave lens is assumed in which the entrance surface has the same curvature, refractive index, and central thickness, and the exit surface is spherical. When the concave lens is arranged at the installation position of the collimating lens 44 with respect to a condensing lens having the same shape as the predetermined shape, the transmitted light is converted into parallel light in the paraxial region (region near the rotation axis). The curvature of the exit surface of the concave lens that can be converted is obtained.

  The value of the curvature thus obtained is the paraxial curvature c in the above equation (3) that defines the shape of the exit surface 44b. Here, when the incident surface 44a of the collimating lens 44 is a flat surface, the curvature of the incident surface 44a is set to zero.

  Next, the conic constant K is obtained. In the light source device 1 of the present embodiment, the conic constant K is set to a condition under which parallel light is emitted by performing a simulation using the equation (3) while changing its value. In this simulation, when the light beam emitted from the light source device 1 is condensed by an ideal lens having no aberration, the condition that the light spot diameter at the condensing point is the smallest is the condition under which substantially parallel light is emitted. It can be considered.

  Also in this modification, the parallelism of the excitation light that passes through the collimating lens 44 can be further improved. For this reason, it is easy to average the excitation light using the first lens array 51 and the condensing optical system, and it becomes easy to suppress the light saturation and cause the light emitting element 80 to emit light.

  In the light source device 1 of the present embodiment, the rotating plate 81 is used as the substrate on which the phosphor layer 82 is formed. However, the present invention is not limited to this. For example, a substrate that can vibrate in a direction crossing the direction in which excitation light is incident may be used as the substrate on which the phosphor layer is formed.

  Further, in the light source device 1 of the present embodiment, a rotating (moving) light emitting element is used as the light emitting element 80, but the present invention is not limited thereto. For example, a fixed light emitting element may be used.

  In the light source device 1 of the present embodiment, the solid light sources 13 and 23 that emit blue light as excitation light and the phosphor layer 82 that emits fluorescence including red light and green light from the blue light are used. Not limited to. For example, you may use each solid light source which inject | emits purple light or ultraviolet light as excitation light, and the fluorescent substance layer which emits colored light containing red light, green light, and blue light from purple light or ultraviolet light.

  In addition, the light source device 1 of the present embodiment is configured to emit white light as a whole, but is not limited thereto, and may be configured to emit light other than white light.

  Further, in the light source device 1 of the present embodiment, the angle formed between the optical axis 10ax of the afocal optical system 40 and the excitation light combining surface is set to 45 degrees, and the light is emitted from the first light source unit 10 on the excitation light combining unit 30. The plurality of first solid light sources 13 and the plurality of second solid light sources 23 are arranged so that the first excitation light does not overlap with the second excitation light emitted from the second light source unit 20. Specifically, as can be seen from FIG. 3, the plurality of first solid light sources 13 are arranged to be shifted in the Z-axis direction relative to the plurality of second solid light sources 23. However, when the angle between the optical axis 10ax of the afocal optical system 40 and the excitation light combining surface is 45 degrees, a plurality of the first excitation light and the second excitation light overlap each other on the excitation light combining unit 30. Even when the first solid light source 13 and the plurality of second solid light sources 23 are arranged, by shifting the angle between the optical axis 10ax of the afocal optical system 40 and the excitation light combining surface from the 45 ° angle, It is possible to prevent the first excitation light from overlapping the second excitation light on the excitation light combining unit 30.

  Moreover, in the light source device 1 of this embodiment, although each solid light source which consists of semiconductor lasers was used, it is not restricted to this. For example, you may use each solid light source which consists of a light emitting diode.

  In the light source device 1 according to the present embodiment, each solid light source including a semiconductor laser that emits blue light having a light emission intensity peak of about 460 nm is used. However, the present invention is not limited to this. For example, you may use each solid light source which consists of a semiconductor laser which inject | emits the blue light whose emission intensity peak is 440 nm-450 nm. By setting it as such a structure, it becomes possible to improve the efficiency which emits fluorescence from blue light in a fluorescent substance layer.

  In the light source device 1 of the present embodiment, the excitation light irradiation region 80a in the phosphor layer 82 is a square having a side of 1 mm, but is not limited thereto. As long as the irradiation area has a size that is included in a square with a side of 1 mm, the irradiation area is a smaller irradiation area (for example, a square with a side of 0.8 mm or a square with a side of 0.6 mm). Also good. With such a configuration, the area of the irradiation region that emits fluorescence can be made sufficiently smaller.

  In the projector 1000 of this embodiment, the liquid crystal light modulation device is used as the light modulation device, but the present invention is not limited to this. Any light modulation device may be used as long as it modulates incident light according to image information, and a micromirror light modulation device or the like may be used. For example, a DMD (digital micromirror device) (trademark of TI) can be used as the micromirror light modulator.

  In the projector 1000 of this embodiment, three liquid crystal light modulation devices are used as the liquid crystal light modulation device, but the present invention is not limited to this. The present invention can also be applied to a projector using one, two, four or more liquid crystal light modulation devices.

  In the projector 1000 of the present embodiment, a transmissive projector is used, but the present invention is not limited to this. For example, a reflective projector may be used. Here, “transmission type” means that the light modulation device as the light modulation means is a type that transmits light, such as a transmission type liquid crystal display device. The “reflective type” means that a light modulation device as a light modulation unit, such as a reflection type liquid crystal display device, reflects light. Even when the present invention is applied to a reflective projector, the same effect as that of a transmissive projector can be obtained.

(Second Embodiment)
FIG. 9 is a schematic diagram showing a light source device 2 according to the second embodiment of the present invention.
As illustrated in FIG. 9, the light source device 2 according to the present embodiment includes a first light source unit 10 </ b> A instead of the first light source unit 10, and includes an excitation light synthesis unit 30 </ b> A instead of the excitation light synthesis unit 30. This is different from the light source device 1 according to the first embodiment described above. Since the other points are the same as the above-described configuration, the same elements as those in FIG. In FIG. 9, the afocal optical system 40, the lens integrator 50, the dichroic mirror 60, the superimposing optical system 70, and the light emitting element 80 are not shown.

  As shown in FIG. 9, the first light source unit 10A includes a first solid light source array 11A and a first collimator lens array 14A. The second light source unit 20 includes a second solid light source array 21 and a second collimator lens array 24.

  FIG. 10 is a front view of a solid light source array (first solid light source array 11 </ b> A, second solid light source array 21) included in the light source device 2. FIG. 10A is a front view of the first solid-state light source array 11 </ b> A, and FIG. 10B is a front view of the second solid-state light source array 21.

  As shown in FIG. 10A, the first solid light source array 11A includes a substrate 12A and 25 first solid light sources 13A that emit blue light as excitation light. In the first solid-state light source array 11A, 25 first solid-state light sources 13A are arranged in a matrix of 5 rows and 5 columns.

  In the light source device 2 of the present invention, the number of the first solid light sources 13A is not limited to 25 and may be two or more.

  The substrate 12A has a function of mounting the first solid light source 13A. For example, the substrate 12A has a function of mediating supply of power to the first solid light source 13A, a function of radiating heat generated by the first solid light source 13A, and the like.

  The first solid-state light source 13A is composed of a semiconductor laser that emits blue light (emission intensity peak: about 460 nm) as excitation light. As shown in FIG. 10A, the semiconductor laser has a rectangular light emitting region, and the divergence angle along the short side direction of the light emitting region is larger than the divergence angle along the long side direction of the light emitting region. It is comprised so that it may become. The size of the light emitting region in the semiconductor laser is, for example, a long side of 8 μm and a short side of 2 μm.

  The first solid-state light source 13A emits blue light composed of P-polarized light with respect to the incident surface of the excitation light combining unit 30A. In order for the excitation light from the first light source unit 10A to enter the excitation light combining unit 30A as excitation light composed of P-polarized light, a solid light source that emits excitation light composed of P-polarized light as described above is used. In addition, a solid light source that emits excitation light composed of S-polarized light with respect to the incident surface of the excitation light combining unit 30A and a λ / 2 plate may be used.

  The first collimator lens array 14A is provided corresponding to the plurality of first solid light sources 13A, and has 25 first collimator lenses 15A. Although not illustrated, the plurality of first collimator lenses 15A are arranged in a matrix of 5 rows and 5 columns. One first collimator lens 15A substantially parallelizes the blue light emitted from one first solid light source 13A among the plurality of first solid light sources 13A. The first collimator lens 15A is a plano-convex lens.

  The first collimator lens array 14A is arranged so that the plane of the plurality of first collimator lenses 15A faces the first solid-state light source array 11A side. The first collimator lens array 14A may be arranged so that the convex surfaces of the plurality of first collimator lenses 15A face the first solid-state light source array 11A side.

  As shown in FIGS. 9 and 10B, the second solid light source array 21 and the second collimator lens array 24 are the same as the second solid light source array 21 and the second collimator lens array 24 according to the first embodiment. Since it has the same structure, detailed description is abbreviate | omitted.

  Also in the light source device 2 according to the present embodiment, as shown in FIGS. 10A and 10B, each of the light emitting region of the first solid light source 13A and the light emitting region of the second solid light source 23 has long sides. The direction and the short side direction are opposite to each other. More specifically, when the light emitting region of the first solid-state light source 13A is projected onto the excitation light combining unit 30A, the long side direction of the light emitting region is the Z-axis direction, and the short side direction of the light emitting region is the Y-axis direction. On the other hand, when the light emitting region of the second solid-state light source 23 is projected onto the excitation light combining unit 30A, the long side direction of the light emitting region is the Y axis direction, and the short side direction of the light emitting region is the Z axis direction. Thus, each of the shape when the light emitting region of the first solid light source 13A is projected onto the excitation light combining unit 30A and the shape when the light emitting region of the second solid light source 23 is projected onto the excitation light combining unit 30A are in the long side direction. And the direction of the short side are opposite to each other.

  On the other hand, as shown in FIGS. 9, 10A, 10B, and 11, the first light source unit 10A and the second light source unit 20 are blue light synthesized by an excitation light synthesis unit 30A described later. The blue light (first excitation light) from the first light source unit 10A and the blue light (second excitation light) from the second light source unit 20 are arranged so as to partially overlap each other on a plane perpendicular to the optical axis. Has been.

  The excitation light synthesizer 30 </ b> A according to the present embodiment includes a plurality of structures 31. One structure 31 of the plurality of structures 31 includes a polarization separation film 32 sandwiched between a first transparent member 33 and a second transparent member 34. For example, glass is used as a material for forming the first transparent member 33 and the second transparent member 34. The excitation light combining unit 30 </ b> A is a so-called cube-type polarization beam combiner in which a plurality of rectangular structures 31 in XZ plan view are combined along the polarization separation film 32.

  The excitation light combining unit 30A is provided with a first transparent member 33 on the side where the first excitation light emitted from the first light source unit 10A is incident on the polarization separation film 32, and from the second light source unit 20 in the polarization separation film 32. A second transparent member 34 is provided on the side on which the emitted second excitation light is incident. The first transparent member 33 and the second transparent member 34 have a triangular shape (here, a right isosceles triangular shape) in the XZ plan view, and have a line-symmetric shape around the polarization separation film 32. The first transparent member 33 and the second transparent member 34 are arranged so that the bases of the right isosceles triangle are opposed to each other with the polarization separation film 32 interposed therebetween in the XZ plan view.

  As described above, the excitation light combining unit 30A according to the present embodiment includes the first interface SF1 between the first transparent member 33 and the polarization separation film 32, and the second interface between the second transparent member 34 and the polarization separation film 32. SF2 is disposed so as to face each other and overlap with the polarization separation film 32 interposed therebetween.

  FIG. 11 is a diagram illustrating an incident region of the first excitation light and an incident region of the second excitation light in the excitation light combining unit 30A. In FIG. 11, the portion surrounded by the solid line is the first excitation light incident region, and the portion surrounded by the broken line is the second excitation light incident region.

  As shown in FIGS. 9 and 11, the incident areas of the first excitation light are distributed in a matrix of 5 rows and 5 columns, and the incident areas of the second excitation light are distributed in a matrix of 5 rows and 5 columns. Further, the optical axis of the first excitation light emitted from the first light source unit 10A and the optical axis of the second excitation light emitted from the second light source unit 20 intersect each other in the excitation light combining unit 30A. It is configured. Therefore, in the excitation light combining unit 30A, the first excitation light overlaps with the second excitation light. As a result, a matrix-like intensity distribution of 5 rows and 5 columns is obtained.

  According to the light source device 2 of the present embodiment, the first excitation light emitted from the first light source unit 10 </ b> A enters the polarization separation film 32 through the first transparent member 33 and is emitted from the second light source unit 20. The second excitation light enters the polarization separation film 32 via the second transparent member 34. Therefore, even if the refractive index difference is large between the polarization separation film 32 and the air layer (the medium through which excitation light from the two light source units enters the polarization separation film 32), the refractive index difference Can be relaxed. Therefore, the first transparent member 33 and the second transparent member 34 according to the present invention are not disposed on the polarization separation film 32, and the excitation light from the two light source units is directly incident on the polarization separation film 32. It is possible to suppress the occurrence of light loss due to the large refractive index difference.

  Further, according to this configuration, the first interface SF1 and the second interface SF2 are arranged so as to face each other and overlap with the polarization separation film 32 interposed therebetween. For this reason, in the case where each of the first excitation light and the second excitation light is configured to be incident on regions facing each other across the polarization separation film 32 in the excitation light combining unit 30A, the first transparent member 33 and the second transparent member 34 facilitate the relaxation of the refractive index difference. Therefore, it is possible to suppress the loss of light due to the large difference in refractive index.

(Third embodiment)
FIG. 12 is a schematic diagram showing a light source device 3 according to the third embodiment of the present invention.
As shown in FIG. 12, the light source device 3 according to the present embodiment is different from the light source device 1 according to the first embodiment described above in that an excitation light combining unit 30B is provided instead of the excitation light combining unit 30. . Since the other points are the same as the above-described configuration, the same elements as those in FIG. In FIG. 12, the afocal optical system 40, the lens integrator 50, the dichroic mirror 60, the superimposing optical system 70, and the light emitting element 80 are not shown.

  As shown in FIG. 12, the excitation light combining unit 30B according to this embodiment is configured by attaching a first transparent member 33B and a second transparent member 34B with a polarization separation film 32B interposed therebetween. The first transparent member 33B and the second transparent member 34B are, for example, triangular prisms. In the excitation light combining unit 30B, a plurality of triangular first transparent members 33B and second transparent members 34 in the XZ plan view are arranged along the polarization separation film 32B.

  In the excitation light combining unit 30B, the first transparent member 33B is provided on the side where the first excitation light emitted from the first light source unit 10 is incident, and the second excitation light emitted from the second light source unit 20 is incident. The second transparent member 34B is provided on the side to be used. The first transparent member 33B and the second transparent member 34B have a triangular shape (here, a right isosceles triangular shape) in the XZ plan view, and have a line-symmetric shape with respect to the polarization separation film 32B. The first transparent member 33 </ b> B and the second transparent member 34 </ b> B are arranged so that the bases of the right isosceles triangles face each other with the polarization separation film 32 interposed therebetween in the XZ plan view.

  Thus, the excitation light combining unit 30B according to the present embodiment includes the first interface SF1 between the first transparent member 33B and the polarization separation film 32B, and the second interface between the second transparent member 34B and the polarization separation film 32B. SF2 is disposed so as to partially overlap with the polarization separation film 32B.

  Here, the plurality of first transparent members 33B are provided at a predetermined pitch on the side where the first excitation light is incident on the polarization separation film 32B, and the plurality of second transparent members 34B are the second ones of the polarization separation film 32B. Are provided at a predetermined pitch on the side on which the excitation light is incident. In the excitation light combining unit 30B according to the present embodiment, the first interface SF1 and the second interface SF2 are arranged so as to be shifted from each other by a half pitch with the polarization separation film 32B interposed therebetween.

  For example, in FIG. 12, in the XZ plan view, the midpoint of the bottom of one first transparent member 33B is CP1, and the midpoint of the bottom of one second transparent member 34B is CP2. In this case, one end of the first transparent member 33B overlaps the midpoint CP2 of the bottom of the second transparent member 34B. Also, one end of the second transparent member 34B overlaps with the midpoint CP1 of the bottom of the first transparent member 33B.

  According to the light source device 3 of the present embodiment, each of the region where the first excitation light is incident on the polarization separation film 32B and the region where the second excitation light is incident on the polarization separation film 32B are identical in the polarization separation film 32B. Arranged so as to overlap. Therefore, it is possible to suppress the occurrence of unevenness in the synthetic excitation light.

(Fourth embodiment)
FIG. 13 is a schematic diagram showing a light source device 4 according to the fourth embodiment of the present invention.
As shown in FIG. 13, the light source device 4 according to the present embodiment is different from the light source device 2 according to the second embodiment described above in that an excitation light combining unit 30C is provided instead of the excitation light combining unit 30A. Since the other points are the same as the above-described configuration, the same elements as those in FIG.

  The excitation light combining unit 30A according to the second embodiment is a so-called cube-type polarization beam combiner in which a plurality of rectangular structures 31 in XZ plan view are combined along the polarization separation film 32. The excitation light combining unit 30C according to the present embodiment does not have such a configuration.

  That is, as shown in FIG. 13, the excitation light combining unit 30C according to the present embodiment is configured by attaching the first transparent member 33C and the second transparent member 34C with the polarization separation film 32C interposed therebetween. The first transparent member 33C and the second transparent member 34C are, for example, triangular prisms. In the excitation light combining unit 30C, a plurality of triangular first transparent members 33C and a plurality of second transparent members 34C are arranged side by side along the polarization separation film 32C in the XZ plan view.

  The excitation light combining unit 30C according to the present embodiment includes an entire surface of the first interface SF1 between the first transparent member 33C and the polarization separation film 32C, and a second interface SF2 between the second transparent member 34C and the polarization separation film 32C. The entire surface is arranged so as to face each other and overlap with the polarization separation film 32C interposed therebetween.

  The light source device 4 of the present embodiment is also configured such that each of the first excitation light and the second excitation light is incident on regions facing each other across the polarization separation film 32C in the excitation light combining unit 30C. In some cases, the first transparent member 33C and the second transparent member 34C can easily relax the refractive index difference. Therefore, it is possible to suppress the loss of light due to the large difference in refractive index.

(Fifth embodiment)
FIG. 14 is a schematic diagram showing a light source device 5 according to the fifth embodiment of the present invention.
As shown in FIG. 14, the light source device 5 according to the present embodiment is different from the light source device 1 according to the first embodiment described above in that an excitation light combining unit 30 </ b> D is provided instead of the excitation light combining unit 30. . Since the other points are the same as the above-described configuration, the same elements as those in FIG. In FIG. 14, the afocal optical system 40, the lens integrator 50, the dichroic mirror 60, the superimposing optical system 70, and the light emitting element 80 are not shown.

  FIG. 15 is a schematic diagram of an excitation light combining unit 30D according to the present embodiment. 15A is a perspective view of the excitation light combining unit 30D, and FIG. 15B is a view of the excitation light combining unit 30D as viewed from the first light source unit 10 side.

  As shown in FIGS. 15A and 15B, the excitation light combining unit 30D according to the present embodiment transmits a plurality of first excitation lights through a passage area AR1 and a plurality of second excitation lights. A reflection area AR2 for reflection. The passage area AR1 in the excitation light combining unit 30D is composed of a plurality of openings 32Da provided in the polarization separation film 32D. One opening 32Da has a rectangular shape when viewed from the first light source unit 10 side. The plurality of openings 32Da are provided corresponding to the plurality of first solid-state light sources 13, and are arranged in a matrix of 5 rows and 4 columns. The size of the opening 32Da is such that at least a part of the light flux of the first excitation light emitted from the first solid-state light source 13 can pass.

  According to the light source device 5 of the present embodiment, the loss of light caused by the first excitation light passing through the polarization separation film 32D can be suppressed. Therefore, the plurality of first excitation light and the plurality of second excitation light can be suppressed. Can be synthesized with high efficiency.

  The optical axis of the first excitation light emitted from one first solid light source 13 preferably passes through the opening 32Da. This is because the intensity at the optical axis is the strongest among the luminous fluxes of the excitation light. Further, the size of the opening 32Da is such that all of the first excitation light beam emitted from one first solid-state light source 13 is allowed to pass therethrough, and the reflection area AR2 includes a plurality of second excitation light sources. It is preferable that all light beams can be reflected. According to this configuration, it is possible to minimize the loss of light caused by the first excitation light passing through the polarization separation film 32D. Therefore, the plurality of first excitation light, the plurality of second excitation light, Can be synthesized with higher efficiency.

  In the light source device 5 of the present embodiment, the configuration in which the excitation light combining unit 30D has the opening 32Da in the passage region AR1 of the polarization separation film 32D has been described as an example. However, the configuration is not limited thereto. For example, a reflection mirror having a hole in a region corresponding to the passing region may be used as the excitation light combining unit. A transparent substrate in which a reflective layer is formed in a region corresponding to the reflective region may be used.

  However, with such a configuration, light loss may occur when the excitation light is incident on the boundary portion between the passage region and the reflection region. Therefore, in order to suppress the loss of light even when the excitation light is incident on the boundary portion between the passage region and the reflection region, a hole is formed in the polarization separation film 32D as in this embodiment. A configuration in which the opening 32Da formed in this manner is used as the passage area AR1 is preferable.

(Sixth embodiment)
FIG. 16 is a schematic diagram showing a projector 2000 according to the sixth embodiment of the invention.
As shown in FIG. 16, the projector 2000 according to the present embodiment includes the illumination device 100 </ b> E instead of the illumination device 100 (the first described above in that the light source device 6 is provided instead of the light source device 1). This is different from the projector 1000 according to the embodiment, since the other points are the same as those in the above-described configuration, the same elements as those in FIG.

  As shown in FIG. 16, in the projector 2000, the light source device 6 is partially in common with the light source device 1 according to the first embodiment. The difference is that the lens integrators are not paired and the first lens array 51 is used alone. In the present embodiment, the superimposing optical system 70 functions as the condensing optical system of the present invention.

  FIG. 17 is an explanatory diagram showing functions of the first lens array 51 and the superimposing optical system 70. In FIG. 17, for simplicity, the superimposing optical system 70 is schematically illustrated as one convex lens. It is assumed that the superimposing optical system 70 has no spherical aberration or has been reduced by correcting the spherical aberration.

  In FIG. 17, for convenience, only a portion of the light emitting element 80 corresponding to the excitation light irradiation region 80a is shown. The excitation light irradiation region 80a in the phosphor layer 82 has, for example, a substantially square shape of 1 mm × 1 mm in plan view.

  As shown in FIG. 17A, in the optical system including the first lens array 51 and the superimposing optical system 70, the excitation light (blue light B) incident on the first lens array 51 is parallel light. The principal ray of the excitation light that has passed through the first lens array 51 and the superimposing optical system 70 passes through the focal point F2 of the superimposing optical system 70. In other words, the object plane of the optical system having both ends of the first lens array 51 and the superimposing optical system 70 is set to infinity. That is, an optical system including the first lens array 51 and the superimposing optical system 70 is object-side telecentric. In such an optical system, incident excitation light (blue light B) passes through the first lens array 51 and then enters the superimposing optical system 70, and the excitation light emitted from the superimposing optical system 70 is superimposed optical. It passes through the exit pupil P having a constant width according to the system 70.

  In such a configuration, the width of the exit pupil P is determined to be a constant size by the numerical aperture NA and the focal length Lb of the superposition optical system 70. Further, the shape of the exit pupil P is similar to the small lens 51 a constituting the first lens array 51. That is, the width of the exit pupil P is always constant regardless of the distance La between the superimposing optical system 70 and the first lens array 51. For example, the entrance pupil P is designed to have a substantially square shape of 1 mm × 1 mm.

  Therefore, as shown in FIG. 17B, the light emitting element 80 having the same size as the exit pupil is disposed at the position of the focal point F2 of the superimposing optical system 70, and the surface conjugate with the light irradiation surface 80a is set to infinity. By doing so, it is possible to reduce the number of lens arrays used (without using the second lens array shown in FIG. 1) compared to the light source device 1 of the first embodiment. As a result, the light intensity of the excitation light can be averaged with a small number of components, and the light emitting element 80 can be irradiated.

  According to the light source device 5 of the present embodiment, since the excitation light divided into a plurality of light bundles by the first lens array 51 is collected by the superimposing optical system 70, the light intensity distribution is averaged. In addition, in the exit pupil P shown in FIG. 17A, since the excitation light is not imaged, the excitation light image is blurred and the light intensity is easily averaged. Therefore, it becomes easy to control the amount of light so as not to cause light saturation in the light emitting element 80.

  Further, according to this configuration, the planar view shape of the plurality of small lenses 51 a constituting the first lens array 51 is similar to the planar view shape of the light irradiation surface 80 a of the light emitting element 80, and the light of the light emitting element 80 The planar view area of the irradiation surface 80a is substantially equal to the size of the exit pupil P of the integrated optical system. Thereby, excitation light can be irradiated to the light emitting element 80 without waste. For this reason, it is possible to maximize the amount of fluorescence to be extracted with respect to the amount of excitation light to be input.

  In the present embodiment, the planar view area of the light irradiation surface 80a of the light emitting element 80 is substantially equal to the size of the exit pupil P. However, even if, for example, the exit pupil P is larger, a part of the excitation light is wasted, but since light saturation in the light emitting element 80 is suppressed, an improvement in light emission efficiency can be expected.

  In the present embodiment, the light irradiation surface 80a is arranged so as to overlap with the focal point F2 of the superimposing optical system 70. However, even if the light irradiation surface 80a is deviated from the focal point F2, excitation is performed via the first lens array 51. The effect of superimposing light can be expected, and the light intensity of the excitation light tends to be averaged. Therefore, the light saturation phenomenon in the light emitting element 80 can be suppressed and a light source with high luminous efficiency can be obtained.

(Seventh embodiment)
FIG. 18 is a schematic diagram showing a projector 3000 according to the seventh embodiment of the present invention.
As shown in FIG. 18, the projector 3000 according to this embodiment includes a lighting device 100 </ b> F instead of the lighting device 100 (a point including a light source device 7 instead of the light source device 1, a color separation light guide). It differs from the projector 1000 according to the first embodiment described above in that it includes a color separation light guide optical system 202 instead of the optical system 200 and further includes a second illumination device 700. Other points are described above. Therefore, the same elements as those of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the said 1st Embodiment, although the light emitting element 80 which emits the fluorescence containing red light and green light from some blue light was used, this invention is not limited to this. The light source device 7 according to the present embodiment includes a light emitting element 80F that emits fluorescence (red light and green light) from the entire blue light. The light emitting element 80F according to the present embodiment is a so-called transmission type light emitting element that emits fluorescence from the side opposite to the side on which the excitation light is incident. The light emitting element 80F is a fixed light emitting element. The projector 3000 further includes a second lighting device 700 that emits blue light. Reference numeral 720 denotes a blue light source unit, which has the same configuration as the second light source unit 20. Reference numeral 730 denotes a scattering optical system that condenses blue light and scatters it to make it substantially parallel. The blue light generation unit 720 and the scattering optical system 730 constitute a second light source device 710. The first lens array indicated by reference numeral 740 is indicated by the first lens array 120, the second lens array indicated by reference numeral 750 is indicated by the second lens array 130, the polarization conversion element indicated by reference numeral 760 is indicated by the polarization conversion element 140, and reference numeral 770. The superimposing lens has the same configuration as that of the superimposing lens 150. Further, the projector 3000 includes a color separation light guide optical system 202 corresponding to the illumination device 100F and the second illumination device 700.

  Since the projector 3000 of the present embodiment also includes the light source device 7 described above, it is possible to provide the projector 3000 that can further increase the brightness of the display screen without reducing the light use efficiency.

  The present invention is applicable not only when applied to a front projection type projector that projects from the side that observes the projected image, but also when applied to a rear projection type projector that projects from the side opposite to the side that observes the projected image. can do.

  In each of the above-described embodiments, the example in which the light source device of the present invention is applied to a projector has been described. For example, the light source device of the present invention can be applied to other optical devices (for example, an optical disc device, a car headlamp, a lighting device, etc.).

1, 2, 3, 4, 5, 6, 7 ... light source device, 10, 10A ... first light source unit, 11, 11A ... first solid light source array, 13, 13A ... first solid light source, 14, 14A ... first DESCRIPTION OF SYMBOLS 1 collimator lens array, 15 and 15A ... 1st collimator lens, 20 ... 2nd light source part, 21 ... 2nd solid light source array, 23 ... 2nd solid light source, 24 ... 2nd collimator lens array, 25 ... 1st 2 collimator lens, 30, 30A, 30B, 30C, 30D ... excitation light synthesis unit, 32, 32B, 32C, 32D ... polarization separation film, 33, 33B, 33C ... first transparent member, 34, 34B, 34C ... second Transparent member, 41, 43 ... Condensing lens, 42, 44 ... Parallelizing lens, 42a, 44a ... Incident surface, 42b, 44b ... Ejecting surface, 51 ... First lens array (lens array), 51a ... Small lens, 52 ... Two-lens array, 70 ... Superimposing optical system, 80, 80F ... Light emitting element, 200 ... Color separation light guide optical system, 400R, 400G, 400B ... Liquid crystal light modulation device (light modulation device), 600 ... Projection optical system, 1000, 2000, 3000 ... projector, AR1 ... transmission region, AR2 ... reflection region, SF1 ... first interface, SF2 ... second interface, P ... exit pupil, PL ... long pitch, PS ... short pitch, VL ... long side, VS ... Short side

Claims (19)

A first light source unit including a plurality of first solid-state light sources that emit first excitation light;
A second light source unit including a plurality of second solid light sources for emitting second excitation light;
An excitation light combining unit that combines a plurality of the first excitation lights emitted from the first light source unit and a plurality of the second excitation lights emitted from the second light source unit, and emits them as synthesized excitation light; ,
A lens array that divides the combined excitation light emitted from the excitation light combining unit into a plurality of partial beam bundles;
A condensing optical system for condensing the plurality of partial beam bundles;
A light source device including a light emitting element that emits fluorescence when excited by the plurality of partial light bundles collected by the condensing optical system. The excitation light combining unit has a polarization separation film that transmits light incident as P-polarized light and reflects light incident as S-polarized light,
The plurality of the first excitation lights are incident on the excitation light combining unit as P-polarized light, and the plurality of second excitation lights are incident on the excitation light combining unit as S-polarized light. The light source device described. The excitation light combining unit further includes a first transparent member and a second transparent member provided so as to sandwich the polarization separation film,
One first excitation light of the plurality of first excitation lights is incident on the polarization separation film through the first transparent member,
3. The light source device according to claim 2, wherein one second excitation light among the plurality of second excitation lights is incident on the polarization separation film through the second transparent member.   In the excitation light combining unit, an interface between the first transparent member and the polarization separation film and an interface between the second transparent member and the polarization separation film overlap each other with the polarization separation film interposed therebetween. The light source device according to claim 3, arranged as described above.   The excitation light combining unit is configured such that an interface between the first transparent member and the polarization separation film and an interface between the second transparent member and the polarization separation film are part of each other across the polarization separation film. The light source device according to claim 3, wherein the light source devices are arranged so as to overlap each other.   3. The light source device according to claim 1, wherein the excitation light combining unit includes a passing region that allows the plurality of first excitation lights to pass therethrough and a reflection region that reflects the plurality of second excitation lights. Each of the plurality of first solid light sources and the plurality of second solid light sources comprises a semiconductor laser,
The semiconductor laser has a light emitting region having a rectangular shape in plan view, and a light divergence angle along the short side direction of the light emitting region is larger than a light divergence angle along the long side direction of the light emitting region. Configured,
Each of the long side direction and the short side direction of the shape when the light emitting region of one of the plurality of first solid light sources is projected onto the excitation light combining unit is one of the plurality of second solid light sources. 7. The light source device according to claim 1, wherein a long side direction and a short side direction of the shape when the light emitting region of the second solid light source is projected onto the excitation light combining unit are opposite to each other. . The plurality of first solid light sources are arranged in an array,
The first light source unit includes a first collimator lens array having a plurality of first collimator lenses provided corresponding to the plurality of first solid light sources,
One first collimator lens among the plurality of first collimator lenses collimates the first excitation light emitted from one first solid light source among the plurality of first solid light sources,
The plurality of second solid light sources are arranged in an array,
The second light source unit includes a second collimator lens array having a plurality of second collimator lenses provided corresponding to the plurality of second solid light sources,
The one second collimator lens among the plurality of second collimator lenses collimates the second excitation light emitted from one second solid light source among the plurality of second solid light sources. The light source device according to 1. The plurality of first solid light sources are arranged in a matrix so that the long side direction of the light emitting region of each of the plurality of first solid light sources is parallel to the first direction,
The plurality of first collimator lenses are arranged in a matrix corresponding to the arrangement of the plurality of first solid light sources,
The pitch in the first direction of the plurality of first collimator lenses is shorter than the pitch in the direction intersecting the first direction of the plurality of first collimator lenses,
The plurality of second solid light sources are arranged in a matrix so that the long side direction of the light emitting region of each of the plurality of second solid light sources is parallel to the second direction,
The plurality of second collimator lenses are arranged in a matrix corresponding to the arrangement of the plurality of second solid light sources,
The light source device according to claim 8, wherein a pitch in the second direction of the plurality of second collimator lenses is shorter than a pitch in a direction intersecting the second direction of the plurality of second collimator lenses. The condensing optical system is paired with the lens array, and a second lens array on which the partial beam bundle is incident and a superimposition that superimposes the partial beam bundle emitted from the second lens array on the light emitting element. An optical system,
The light source device according to claim 1, wherein a lens surface of the lens array and a light irradiation surface of the light emitting element are in a conjugate relationship via the condensing optical system. The planar view shape of the plurality of small lenses constituting the lens array is similar to the planar view shape of the light irradiation surface,
The light source device according to claim 10, wherein the light intensity distribution of the excitation light that irradiates the light irradiation surface is a light intensity distribution in which the light intensity is continuous at the same spatial position as the light irradiation surface. The light emitting element is provided such that a light irradiation surface overlaps with a focal position of the condensing optical system,
10. The light source device according to claim 1, wherein in the integrated optical system having both ends of the lens array and the condensing optical system, a surface conjugate with the light irradiation surface is set at infinity. . The planar view shape of the plurality of small lenses constituting the lens array is similar to the planar view shape of the light irradiation surface of the light emitting element,
The light source device according to claim 12, wherein a planar view area of a light irradiation surface of the light emitting element is substantially equal to a size of an exit pupil of the integrated optical system. A condensing lens that condenses the combined excitation light emitted from the excitation light combining unit, and a parallelizing lens that parallelizes the combined excitation light emitted from the condensing lens,
The light source device according to any one of claims 10 to 13, wherein the collimating lens has a concave surface having a rotating quadratic curved surface on one of an incident surface and an exit surface.   The light source device according to claim 14, wherein the collimating lens has the incident surface as the concave surface and the emission surface as a flat surface.   The light source device according to claim 14, wherein the collimating lens has a spherical convex surface on the incident surface and the concave surface on the exit surface. The concave surface has coordinate values in an rθZ cylindrical coordinate system in which an intersection point between the concave surface and the central axis of the light beam is an origin, the central axis is a Z axis, and an axis orthogonal to the central axis is an r axis. When the paraxial curvature is c and the conic constant is K,

The light source device according to claim 14, wherein the light source device has a shape represented by:   The first excitation light of the plurality of first excitation lights is configured to be incident on a region different from a region where the plurality of second excitation lights are incident in the excitation light combining unit. Item 18. The light source device according to any one of Items 1 to 17.   19. A light source device according to claim 1, a light modulation element that modulates light emitted from the light source device, and a projection optical system that projects light modulated by the light modulation element. projector.

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