JP2020134896A - Light source device and projector - Google Patents

Abstract

To provide a light source device with which it is possible to realize downsizing while suppressing color shading due to the array form of solid-state light sources, and a projector equipped with the light source device.SOLUTION: A light source device 4 comprises: a light source unit 41 for emitting a first beam composed of blue light BL, a light synthesizing device 50 for separating the first beam into a second beam and a third beam; a diffusion device 45 for emitting a fourth beam derived by diffusing the second beam; a wavelength conversion device 48 excited by the third beam, for emitting a fifth beam composed of fluorescence YL; and a diaphragm 47 in which is formed an opening for emitting a sixth beam that is a partial beam of the fifth beam, the light synthesizing device 50 synthesizing the fourth and sixth beams and emitting a seventh beam as illumination light. Here, the length of opening of the diaphragm 47 seen from a direction parallel to a plane orthogonal to the center light of the third beam corresponds to the size of a maximum incidence angle when the third beam entering the wavelength conversion device 48 is seen from the same direction.SELECTED DRAWING: Figure 2

Description

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

Conventionally, as a light source device used in a projector, a light source device that emits white light including blue light and fluorescence (yellow light) is known (see, for example, Patent Documents 1 and 2). A light source device used in such a projector is generally configured by arranging a large number of solid light sources in a matrix. The blue light emitted from each solid-state light source is converted into parallel light by a collimator optical system provided corresponding to each solid-state light source and emitted. In the projector described in Patent Document 2, the parallel light emitted from the collimator optical system is collected by the pickup optical system and incident on the phosphor layer and the diffuse reflection element.

Here, when the arrangement form of the solid-state light source is different in the in-plane direction, that is, when the emission region of the light emitted from the solid-state light source group has anisotropy in the in-plane direction, the light emitted from the pickup optical system is , Has a brightness distribution corresponding to the arrangement form of solid light sources in the light source device. When this light enters the diffuse reflection element, the incident light is diffusely reflected. Therefore, the diffused light emitted from the diffuse reflection element has a luminance distribution having anisotropy that reflects the luminance distribution of the incident light. On the other hand, in the phosphor layer, the incident light is Lambertian reflected, so that the fluorescence emitted from the phosphor layer has an isotropic luminance distribution. In this way, when diffused light and fluorescence having different brightness distributions are combined to generate illumination light, color unevenness due to the difference in brightness distribution occurs.
In order to suppress color unevenness caused by the arrangement form of solid-state light sources as described above, Patent Document 2 uses a homogenizer optical system, which is an optical system for equalizing the luminance distribution of light emitted from a solid-state light source group. I have.

Japanese Unexamined Patent Publication No. 2012-118302 JP-A-2015-49441

However, when the light source device is provided with a homogenizer optical system, it is necessary to secure a space for arranging the optical system in the optical path, so that the light source device itself becomes large. As a result, there is a problem that it becomes difficult to miniaturize the light source device.

The light source device of the present application includes a light source that emits a first luminous flux belonging to a first wavelength band, a separation unit that separates the first luminous flux into a second luminous flux and a third luminous flux, and the first. A diffuser that ejects a fourth luminous flux in which two light fluxes are incident and diffuses the incident second luminous flux, and the third luminous flux is incident and excited by the incident third luminous flux. A wavelength conversion device that emits a fifth light flux belonging to a second wavelength band different from the first wavelength band, and a sixth light flux to which the fifth light source is incident and is a partial light flux of the fifth light source. A light beam passing through the center of the third light flux, comprising a throttle having an opening for ejection, a compositing section for synthesizing the fourth light flux and the sixth light flux, and emitting a seventh light flux. Is the central light beam, and when viewed from the first direction parallel to the plane orthogonal to the central light beam, the maximum angle between the central light beam and the light beam included in the third light flux is the first incident angle. When viewed from a second direction parallel to the plane orthogonal to the central light beam and orthogonal to the first direction, the maximum angle between the central light beam and the light beam included in the third light flux. Is the second incident angle, and when the first incident angle is larger than the second incident angle, the length of the opening seen from the first direction is larger than the length of the opening seen from the second direction. It is also characterized by being long.

In this light source device, the separation unit comprises a polarization separation element that transmits one of the light flux of the first polarization component and the light flux of the second polarization component different from the first polarization component and reflects the other. It is desirable that the first light beam is separated into the second light beam and the third light beam by the polarization separating element.

In this light source device, the diffuser and the wavelength converter are of a reflection type, and the separation unit also functions as the synthesizer, and the fourth light flux reflected by the diffuser and the wavelength converter It is desirable that the sixth light beam reflected by the polarizing element and transmitted through the aperture is combined with the polarization separating element.

In this light source device, it is desirable that the polarization separating element does not separate the light flux belonging to the second wavelength band by the polarization component.

In this light source device, it is desirable to include a polarization adjusting device which is arranged on an optical path between the light source and the separation portion and adjusts the ratio of the first polarization component contained in the first light flux.

In this light source device, the polarization adjusting device is located between a first retardation plate arranged on an optical path between the light source and the separation portion, the first retardation plate, and the separation portion. A second retardation plate arranged on an optical path is provided, and at least one of the first retardation plate and the second retardation plate can adjust the angle in a plane orthogonal to the first light source. It is desirable to be provided.

The projector of the present application comprises the above-mentioned light source device, an image forming device that modulates the seventh light beam emitted from the light source device to form an image, and a projection that projects the image formed by the image forming device. It is characterized by including an optical device.

The schematic which shows the structure of a projector. The schematic which shows the structure of the light source apparatus. The schematic diagram which shows the arrangement form of a light source unit. A cross-sectional view of the third luminous flux when viewed from the traveling direction. The schematic view when the 3rd light flux is seen from the 1st direction parallel to the plane orthogonal to the traveling direction. The schematic view when the 3rd light flux is seen from the 2nd direction parallel to the plane orthogonal to the traveling direction. The schematic diagram which showed the shape of the diaphragm. The schematic view when the 5th luminous flux and the 6th luminous flux are seen from the 1st direction. The schematic view when the 5th luminous flux and the 6th luminous flux are seen from the 2nd direction.

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.
[Outline configuration of projector]
FIG. 1 is a schematic view showing the configuration of the projector 1 according to the present embodiment.
The projector 1 according to the present embodiment modulates the illumination light emitted from the light source device 4 provided inside the outer housing 2 to form an image corresponding to the image information, and projects the image onto a screen or the like. It is a magnified projection on the surface.

As shown in FIG. 1, the projector 1 includes an image projection device 3 including a light source device 4 and a control device 6 inside the exterior housing 2. Further, although not shown, the projector 1 includes a power supply device for supplying electric power to electronic components constituting the projector 1 and a cooling device for cooling a cooling target constituting the projector 1.
Of these, the control device 6 is configured to include a control circuit and the like, and controls the operation of the projector 1. For example, the control device 6 outputs image information related to the projected image to the light modulation device 343 described later to form image light according to the image information, and also controls lighting of the light source device 4 and the amount of emitted light. ..

[Configuration of image projection device]
The image projection device 3 includes a light source device 4, a homogenization device 31, a color separation device 32, a relay device 33, an image forming device 34, a projection optical device 35, and a housing 36 for optical components. Of these, the light source device 4 emits illumination light, which is a white luminous flux. The configuration of the light source device 4 will be described in detail later.
Here, the emission direction of the illumination light emitted from the light source device 4 toward the image projection device 3 is set to the + X direction. Further, the direction orthogonal to the + X direction and opposite to the projection direction of the projection optical device 35 is defined as the + Z direction. Further, the direction from the bottom surface side to the top surface side of the exterior housing 2 which is orthogonal to the XZ surface and faces the installation surface is defined as the + Y direction. The image projection device 3 is configured as a substantially L-shaped optical unit substantially parallel to the XZ plane. In the following description and figures, a coordinate system based on this definition will be used.

The homogenizing device 31 equalizes the brightness in the plane orthogonal to the central axis of the illumination light incident from the light source device 4. The homogenizing device 31 has a first lens array 311, a dimming device 312, a second lens array 313, a polarization conversion element 314, and a superimposing lens 315 in the order of incidence of the illumination light. The dimming device 312 may be omitted.

Of these, the first lens array 311 has a plurality of first lenses (not shown) that divide the incident illumination light into a plurality of partial luminous fluxes, and the second lens array 313 is from the first lens array 311. It has a plurality of second lenses (not shown) that superimpose a plurality of incident partial luminous fluxes on an optical modulator 343 described later together with a superimposing lens 315. The first lens and the second lens have a one-to-one correspondence with each other, and the partial luminous flux emitted from a certain first lens is incident on the corresponding second lens. Such a second lens array 313 has a conjugate relationship with the diffuser 45 and the wavelength converter 48 described later, and the image formed by the diffuser 45 and the wavelength converter 48 is the image of the second lens array 313. It is reimaged with each second lens. The optical path length between the second lens array 313 and the diffuser 45 coincides with the optical path length between the second lens array 313 and the wavelength conversion device 48.

Further, although detailed illustration is omitted, the polarization conversion element 314 has a plurality of polarization separation layers, reflection layers, and retardation layers, respectively, and has a function of aligning the polarization directions of the incident illumination light.
The plurality of polarization separation layers and the reflection layers are formed long in the ± Y direction, and are arranged alternately in the ± Z direction. Each polarization separation layer is arranged at a position where each partial luminous flux emitted from the second lens array 313 is incident, and each reflection layer is arranged at a position where each partial luminous flux is not directly incident. The plurality of polarization separation layers and reflection layers may be formed long in the ± Z direction and may be arranged alternately in the ± Y direction.
The polarization separation layer allows p-polarized light to pass through and reflects s-polarized light. The reflection layer provided according to the polarization separation layer reflects the s-polarized light reflected by the polarization separation layer along the passing direction of the p-polarized light. Then, each of the plurality of retardation layers is provided on the optical path of p-polarized light that has passed through the polarization separation layer, and the incident p-polarized light is converted into s-polarized light. As a result, the polarization direction of the light emitted from the polarization conversion element 314 is aligned with the s-polarized light, and the s-polarized light is emitted from substantially the entire surface of the light emitting surface of the polarization conversion element 314. The polarization conversion element 314 may be configured to emit p-polarized light.

The color separating device 32 separates the light flux incident from the homogenizing device 31 into three color lights of red light, green light, and blue light. The color separator 32 has a dichroic mirror 321 and 322 and a reflection mirror 323. The dichroic mirror 321 transmits red light and green light, and reflects blue light. The blue light reflected by the dichroic mirror 321 is further reflected by the reflection mirror 323 and incident on the image forming apparatus 34. The dichroic mirror 322 transmits the red light among the red light and the green light transmitted through the dichroic mirror 321 and reflects the green light. The green light reflected by the dichroic mirror 322 is incident on the image forming apparatus 34. Further, the red light transmitted through the dichroic mirror 322 enters the image forming apparatus 34 via the relay device 33.

The relay device 33 is provided on the optical path of red light, which has a longer optical path than the other colored light among the three separated colored lights. The relay device 33 has an incident side lens 331, a relay lens 333, and reflection mirrors 332 and 334, and suppresses a decrease in the illumination efficiency of red light due to a long optical path.

The image forming apparatus 34 modulates each of the separated colored lights according to the image information, and then synthesizes the respective colored lights to form the image light. The image forming apparatus 34 is one that forms an image light by synthesizing each of the modulated colored lights with a field lens 341, an incident side polarizing plate 342, an optical modulator 343, and an emitting side polarizing plate 344 provided for each color light. It has a color synthesizer 345 and.
The light modulator 343 modulates the red light with the red light modulator 343R which modulates the red light and generates the red image light, the green light modulator 343G which modulates the green light and generates the green image light, and the blue light. It includes a blue light modulator 343B that generates blue image light. In the present embodiment, the optical modulation device 343 has a configuration having a liquid crystal panel.
Further, although the color synthesizer 345 is configured by the cross dichroic prism in the present embodiment, it may be configured by combining a plurality of dichroic mirrors. The color synthesizer 345 synthesizes the generated red image light, green image light, and blue image light, and emits them to the projection optical device 35.

The projection optical device 35 magnifies and projects the image light synthesized by the image forming device 34 toward the projected surface arranged outside the exterior housing 2. The projection optical device 35 includes one or more lenses (not shown).

The optical component housing 36 internally houses the optical components constituting the homogenizing device 31, the color separating device 32, the relay device 33, and the image forming device 34. An illumination optical axis Ax, which is a design optical axis, is set in the optical component housing 36, and the illumination optical axis Ax is a central axis of light emitted from the light source device 4, that is, described later. It coincides with the second illumination optical axis Ax2.

[Configuration of light source device]
FIG. 2 is a schematic view showing the configuration of the light source device 4.
As described above, the light source device 4 emits illumination light to the homogenizing device 31. As shown in FIG. 2, the light source device 4 includes a light source unit 41 as a light source, a polarization adjusting device 42, a third retardation plate 43, a first condensing element 44, a diffusing device 45, and a second condensing element 46. It has a throttle 47, a wavelength conversion device 48, a fourth retardation plate 49, and a photosynthesis device 50.

Of these, the light source unit 41, the polarization adjusting device 42, the third retardation plate 43, the first condensing element 44, and the diffusing device 45 are arranged on the first illumination optical axis Ax1 along the + Z direction. Further, the wavelength conversion device 48, the diaphragm 47, the second condensing element 46, and the fourth retardation plate 49 are arranged on the second illumination optical axis Ax2 along the + X direction. Further, the photosynthetic apparatus 50 is arranged at a position where the first illumination optical axis Ax1 and the second illumination optical axis Ax2 intersect. In FIG. 2, the first illumination optical axis Ax1 and the second illumination optical axis Ax2 are orthogonal to each other, but the present invention is not limited to this, and the first illumination optical axis may not be completely orthogonal to each other.

[Structure of light source unit]
The light source unit 41 includes a solid light source 411, a microlens 412, and a heat radiating member 413. The microlens 412 corresponding to the solid light source 411 is arranged along the + Z direction to form the solid light source unit SL. The solid light source 411 emits blue light BL, and the blue light BL emitted from the solid light source 411 incident on the microlens 412. The microlens 412 emits the incident blue light BL as parallel light parallel to the + Z direction.
The light source unit 41 constitutes a light source unit SU in which a plurality of solid light source units SL are arranged in a vertical and horizontal matrix in a plane parallel to the XY plane. Each solid light source unit SL constituting the light source unit SU emits blue light BL in the + Z direction. Therefore, the blue light BL emitted from the light source unit 41 is in a state in which a plurality of light fluxes having a predetermined spot diameter are arranged in a matrix. Hereinafter, a plurality of light fluxes emitted from the light source unit 41 are collectively regarded as one light flux, and are referred to as a first light flux.

As the solid-state light source 411, an LD (Laser Diode) that emits s-polarized blue light BL having a peak wavelength of 440 nm is adopted in the present embodiment. However, an LD that emits blue light BL having a peak wavelength of 446 nm or 460 nm may be adopted as the solid-state light source 411. Further, an LD that emits p-polarized blue light BL may be adopted as the solid-state light source 411. Further, the solid-state light source 411 is not limited to the LD, and may be an LED (Light Emitting Diode).
The blue light BL emitted from the solid-state light source 411 is also used as excitation light for exciting the phosphor contained in the wavelength conversion device 48 described later. For this reason, in the following description, the blue light BL emitted from the light source unit 41 may be referred to as excitation light.

The heat radiating member 413 is used for cooling the solid-state light source 411. The heat radiating member 413 is connected to the solid light source 411, and heats the heat generated by the solid light source 411 and dissipates the heat to cool the solid light source 411. Further, the heat radiating member 413 also has a function as a support member that supports the solid light source 411 and integrates the light source unit 41. Although not shown, the heat radiating member 413 has a heat receiving portion that supports a solid-state light source 411 and transmits heat, and a heat sink having a plurality of fins.

[Polarization adjustment device configuration]
The polarization adjusting device 42 includes a first retardation plate 421 and a second retardation plate 422. The first retardation plate 421 and the second retardation plate 422 are each composed of a 1/4 wave plate. Either one or both of the first retardation plate 421 and the second retardation plate 422 are rotatably provided with the first illumination optical axis Ax1 as a rotation axis.
The blue light BL emitted from the light source unit 41 is incident on the first retardation plate 421 of the polarization adjusting device 42 along the first illumination optical axis Ax1. The incident blue light BL is converted into circularly polarized light by the first retardation plate 421 and emitted. The circularly polarized light emitted from the first retardation plate 421 is incident on the second retardation plate 422 arranged after the first retardation plate 421. The circularly polarized light incident on the second retardation plate 422 is converted into p-polarized light and s-polarized light, which are linearly polarized light components, at a predetermined ratio and emitted. At this time, the ratio of the emitted p-polarized light and the s-polarized light is determined by the rotation angle of the second retardation plate 422 with respect to the first retardation plate 421 in the XY in-plane direction orthogonal to the first illumination optical axis Ax1. Therefore, by rotating at least one of the first retardation plate 421 and the second retardation plate 422, the ratio of the polarization component to the blue light BL emitted from the polarization adjustment device 42 can be adjusted.

The blue light BL containing both p-polarized light and s-polarized light emitted from the polarization adjusting device 42 is separated by a photosynthetic device 50 provided with a polarization separating element 51 described later. Specifically, the p-polarized blue light BL passes through the photosynthesis device 50 and enters the diffuser 45. The p-polarized light incident on the diffuser 45 is diffusely reflected and becomes a blue light component contained in the illumination light. On the other hand, the s-polarized blue light BL is reflected by the photosynthetic device 50 and is incident on the wavelength conversion device 48. The s-polarized light incident on the wavelength converter 48 excites the phosphor and is used as excitation light for generating fluorescent YL.

As described above, the polarization adjusting device 42 has a role of adjusting the amount of illumination light emitted from the light source device 4 and the white balance by adjusting the ratio of the emitted p-polarized light and the s-polarized light.
Of the luminous flux contained in the blue light BL, the partial luminous flux that passes through the photosynthetic apparatus 50 and heads toward the diffuser 45 is also referred to as a second luminous flux. Further, among the luminous fluxes contained in the blue light BL, the partial luminous flux reflected by the photosynthetic apparatus 50 and directed toward the wavelength conversion apparatus 48 is also referred to as a third luminous flux.

[Structure of the first condensing element]
The first condensing element 44 is arranged along the first illumination optical axis Ax1 on the optical path between the diffusing device 45 and the photosynthetic device 50. The first condensing element 44 is a condensing element that condenses p-polarized light, which is a second light beam emitted from the polarization adjusting device 42 and transmitted through the photosynthetic device 50, to the position of the diffusing device 45, and also the diffusing. It is also a parallelizing element that parallelizes the diffused light diffusely reflected by the device 45 and emits it toward the photosynthetic device 50. The luminous flux of the diffused light that is diffusely reflected by the diffuser 45 and directed toward the photosynthetic apparatus 50 is also referred to as a fourth luminous flux.
In the present embodiment, the first condensing element 44 is configured to include three lenses 441 to 443, but the number of lenses constituting the first condensing element 44 can be appropriately changed.

[Structure of third retardation plate]
A third retardation plate 43 is arranged on the optical path between the photosynthetic apparatus 50 and the lens 441 of the first condensing element 44. The third retardation plate 43 is formed of a 1/4 wavelength plate. The p-polarized light incident on the photosynthetic device 50 from the polarization adjusting device 42 along the first illumination optical axis Ax1 and transmitted through the photosynthetic device 50 is converted into circular polarization by passing through the third retardation plate 43. The circularly polarized light is condensed at the position of the diffusing device 45 by the first condensing element 44, and diffusely reflected by the diffusing device 45. The diffusely reflected circularly polarized light is incident on the first condensing element 44 again, parallelized, and then passes through the third retardation plate 43 again. As a result, the circularly polarized light is converted into s-polarized light. Since the s-polarized blue light BL converted by the third retardation plate 43 is reflected by the polarization separating element 51 of the photosynthesis apparatus 50, the course is changed in the direction (+ X direction) along the second illumination optical axis Ax2. Is emitted from the light source device 4.

[Diffusion device configuration]
The diffuser 45 is located on the first illumination optical axis Ax1 and on the optical path behind the first condensing element 44. The diffuser 45 diffuses and reflects the circularly polarized light incident from the first condensing element 44, which is converted by the third retardation plate 43, at a predetermined diffusivity. That is, in the present embodiment, the diffuser 45 is a reflective diffuser. However, the mode of the diffuser 45 is not limited to this, and a transmission type diffuser may be used.
Such a diffusion device 45 has a diffusion layer 451 that diffuses and reflects incident light and a substrate 452 that supports the diffusion layer 451. The diffusion layer 451 is one surface of the substrate 452, that is, the first collection. It is formed on the surface of the optical element 44 on the side facing the lens 443. A rotating device for rotating the substrate 452 may be provided with an axis substantially parallel to the first illumination optical axis Ax1 as a rotating axis. The rotating device has an effect that the speckle can be effectively reduced by rotating the substrate 452.

[Structure of the second condensing element]
The second light collecting element 46 is arranged along the second optical axis Ax2 on the optical path between the photosynthetic device 50 and the wavelength conversion device 48. The second light collecting element 46 collects the s-polarized blue light BL, which is the third light beam emitted from the polarization adjusting device 42 and reflected by the photosynthetic device 50, at the position of the wavelength conversion element 481 of the wavelength conversion device 48. In addition to being a light-collecting element, it is also a parallelizing element that collimates fluorescent YL, which is conversion light generated by the wavelength conversion element 481 of the wavelength conversion device 48, and emits it toward the photosynthesis device 50. The luminous flux of the converted light emitted from the wavelength conversion device 48 and directed to the diaphragm 47, which will be described later, is also referred to as a fifth luminous flux.
In the present embodiment, the second condensing element 46 is configured to include three lenses 461 to 463, but the number of lenses constituting the second condensing element 46 can be appropriately changed.

[Structure of wavelength converter]
The wavelength conversion device 48 is excited by the incident excitation light and emits fluorescent YL as conversion light having a wavelength different from that of the excitation light. The wavelength conversion device 48 includes a wavelength conversion element 481, a disk-shaped support 482 that supports the wavelength conversion element 481, and a rotating device 483 that rotates the support 482. In the present embodiment, the wavelength conversion device 48 is a reflection type wavelength conversion device that emits the generated fluorescent YL in the incident direction of the excitation light, but the aspect of the wavelength conversion device 48 is not limited to this. , A transmission type wavelength converter may be used.

Although not shown in detail, the wavelength conversion element 481 has a reflection layer located on the incident side surface of the support 482 and a wavelength conversion layer located on the reflection layer. The wavelength conversion element 481 is a circular circle whose radius is the distance from the rotation axis of the rotating device 483 to the condensing position of the s-polarized blue light BL which is the excitation light on the surface of the support 482 parallel to the YZ plane. It is arranged in a strip shape at a position on the circumference.
The wavelength conversion layer is a phosphor layer containing a phosphor that is excited by excitation light and emits unpolarized fluorescent YL. In the present embodiment, the fluorescent YL is yellow light having a peak wavelength in the wavelength range of 500 to 700 nm, but the fluorescent YL is not limited to this, and may be, for example, green light or red light. A part of the fluorescent YL generated in this wavelength conversion layer is emitted toward the second condensing element 46 side, that is, the + X direction, and the other part is emitted toward the reflective layer side, that is, the −X direction. To.
Among the fluorescent YLs generated by the wavelength conversion layer, the reflective layer reflects the fluorescent YLs emitted toward the reflective layer side toward the second light collecting element 46 side.

The rotating device 483 rotates the wavelength conversion element 481 supported by the support 482 with an axis substantially parallel to the second illumination optical axis Ax2 as a rotating axis.
By rotating the wavelength conversion element 481 by the rotating device 483, there is a role of preventing a specific portion of the wavelength conversion element 481 from being always located at a condensing position of s-polarized light which is excitation light. As a result, the occurrence of thermal saturation of the wavelength conversion element 481 can be suppressed.

[Aperture configuration]
A plate-shaped diaphragm 47 (see FIG. 5) is arranged on the optical path between the wavelength conversion device 48 and the second condensing element 46. The diaphragm 47 is formed with a substantially rectangular opening 471 through which a part of the incident fluorescent YL light flux passes, and the other partial light flux is shielded by the diaphragm 47. Here, the size of the opening 471 is separated by the photosynthetic device 50 among the light flux incident on the diaphragm 47, does not block the third light flux toward the wavelength conversion device 48, and is generated by the wavelength conversion device 48 and photosynthesized. It is set to block a part of the fifth luminous flux toward the device 50. Details will be described later.

By making the size of the opening 471 larger than the luminous flux width of the third light beam, the s-polarized blue light BL, which is the excitation light, is not blocked by the diaphragm 47. Therefore, all of them are incident on the wavelength conversion element 481 of the wavelength conversion device 48 and can be used as excitation light without waste. Further, by making the size of the opening 471 smaller than the luminous flux width of the fifth light beam, a part of the light flux of the fluorescent YL emitted from the wavelength conversion device 48 and incident on the diaphragm 47 is generated by the diaphragm 47. Be blocked. A light absorbing member for absorbing the blocked fluorescent YL is formed in the diaphragm 47. The fluorescent YL blocked by the diaphragm 47 is absorbed by the light absorbing member. As the light absorbing member, any light absorbing material, antireflection material, or the like used in general optical equipment can be used. The diaphragm 47 is not limited to a plate-shaped member arranged apart from the second condensing element 46. For example, a light absorbing material, an antireflection material, or the like is provided on the surface of the lens 463 of the second condensing element 46. May be placed directly to function as the aperture 47.

Hereinafter, the partial luminous flux of the fluorescent YL that has passed through the opening 471 of the diaphragm 47 is also referred to as a sixth luminous flux. The sixth luminous flux is incident on the second condensing element 46, parallelized by the second condensing element 46, and incident on the photosynthetic apparatus 50. The sixth luminous flux passes through the photosynthetic apparatus 50 and becomes a yellow light component contained in the illumination light.

[Configuration of photosynthesis device]
The photosynthesis device 50 has a function as a separating unit that separates the blue light BL, which is the first luminous flux, into the p-polarized flux, which is the second luminous flux, and the s-polarized flux, which is the third luminous flux, and diffuse reflection by the diffuser 45. It also functions as a compositing unit that synthesizes the fourth luminous flux, which is the diffused light, and the sixth luminous flux, which is the partial luminous flux of the fifth luminous flux, which is the fluorescent YL generated by the wavelength conversion device 48. There is.

In the present embodiment, the photosynthetic apparatus 50 includes a polarization separating element 51 having wavelength selectivity. Specifically, the polarization separating element 51 transmits the light beam having the first polarization component among the linearly polarized light components included in the light beam for the light beam in the predetermined first wavelength band, while the first one. It functions as a polarization separation membrane that reflects a light beam having a second polarization component different from the polarization component. Further, the polarization separating element 51 does not separate the light flux in the second wavelength band different from the first wavelength band by the linearly polarized light component contained in the light flux. That is, it functions as a dichroic optical element that transmits light regardless of the linearly polarized light component.

In the present embodiment, the blue light BL is included in the first wavelength band, while the fluorescent YL is included in the second wavelength band. The first polarized light component is p-polarized light, and the second polarized light component is s-polarized light. Therefore, when the blue light BL belonging to the first wavelength band is incident on the photosynthetic apparatus 50, the s-polarized light is reflected while the p-polarized light is transmitted. Further, when the fluorescent YL generated by exciting the wavelength conversion element 481 of the wavelength conversion device 48 by s polarization is incident on the photosynthesis device 50, all of them pass through the photosynthesis device 50.

However, the characteristics of the polarization separating element 51 having wavelength selectivity constituting the photosynthetic apparatus 50 are not limited to this embodiment, and can be appropriately changed. For example, the photosynthetic apparatus 50 may be configured to reflect a light flux in a second wavelength band different from the first wavelength band regardless of the linear polarization component contained in the light flux. Further, the photosynthetic apparatus 50 may be configured so as to reflect the p-polarized light and transmit the s-polarized light with respect to the light flux belonging to the first wavelength band.

In the present embodiment, the fourth luminous flux, which is the luminous flux of the blue light BL that is diffusely reflected by the diffuser 45 and converted into s-polarized light by the third retardation plate 43, is reflected by the photosynthetic apparatus 50 and is the second illumination light. The course is changed in the + X direction along the axis Ax2. Further, the sixth luminous flux, which is a partial luminous flux of the fluorescent YL generated by the wavelength conversion device 48 and has passed through the diaphragm 47, passes through the photosynthetic apparatus 50 and travels in the + X direction along the second illumination optical axis Ax2. The luminous flux obtained by combining the fourth luminous flux and the sixth luminous flux becomes the illumination light. The fourth luminous flux is the blue light component of the illumination light, and the sixth luminous flux is the yellow light component of the illumination light. Hereinafter, the luminous flux of the illumination light emitted from the photosynthetic apparatus 50 is also referred to as a seventh luminous flux.

Further, in the present embodiment, the photosynthetic apparatus 50 is arranged at a position where the first illumination optical axis Ax1 and the second illumination optical axis Ax2 intersect. Further, it is arranged so that a part of the luminous flux emitted in the + Z direction intersects each of the first illumination optical axis Ax1 and the second illumination optical axis Ax2 and is reflected in the −X direction. ing. However, the arrangement of the photosynthesis device 50 is not limited to this, and can be appropriately changed according to the layout of the diffuser device 45 and the wavelength conversion device 48.

[Structure of 4th retardation plate]
The fourth retardation plate 49 converts the polarization component of the illumination light, which is the seventh luminous flux emitted from the photosynthetic apparatus 50. Specifically, the fourth retardation plate 49 is a 1/4 wave plate that converts both the blue light component and the yellow light component contained in the illumination light into circularly polarized light. The reason why the fourth retardation plate 49 is provided is as follows.
The fluorescent YL generated by the wavelength conversion element 481 of the wavelength conversion device 48 is unpolarized. In the present embodiment, the retardation plate is not arranged on the optical path of the second illumination optical axis Ax2 from the wavelength conversion device 48 to the photosynthesis device 50. Therefore, the yellow light component of the seventh luminous flux emitted from the photosynthetic apparatus 50 is also unpolarized. On the other hand, the fourth luminous flux, which is the diffused light that has passed through the third retardation plate 43, is s-polarized as described above.

Here, consider the case where the fourth retardation plate 49 is not arranged. Then, when the yellow light component of the seventh light beam is incident on the polarization conversion element 314, one of the polarization components of p-polarized light and s-polarized light is reflected by the polarization separation layer and then reflected by the reflection layer. Then, it is emitted from the polarization conversion element 314. On the other hand, the other polarization component is transmitted through the polarization separation layer, then converted into one polarization component by the retardation layer, and emitted from the polarization conversion element 314. Here, it can be considered that the unpolarized yellow light component contains half and half of each polarized component of p-polarized light and s-polarized light. Therefore, the yellow light component of the seventh luminous flux is emitted from substantially the entire surface of the light emitting surface of the polarization conversion element 314.

On the other hand, since the blue light component of the seventh luminous flux contains only s-polarized light, when this is incident on the polarization conversion element 314, all the blue light component of the seventh luminous flux is reflected or transmitted by the polarization separation layer. .. Therefore, the blue light component is emitted only from a part of the light emitting surface of the polarization conversion element 314. Therefore, since the distributions of the yellow light component and the blue light component emitted from the polarization conversion element 314 are different, color unevenness occurs in the illumination light emitted from the homogenizing device 31.

On the other hand, when the 1/4 wave plate which is the 4th retardation plate 49 is arranged on the optical path between the photosynthesis apparatus 50 and the homogenizing apparatus 31, the yellow light component and the blue light component contained in the 7th luminous flux Are both converted to circularly polarized light. Therefore, when the fourth retardation plate 49 is arranged, both the yellow light component and the blue light component are emitted from substantially the entire surface of the light emitting surface of the polarization conversion element 314, and the illumination emitted from the homogenizing device 31. The color unevenness of light can be suppressed.

[About the emitted light from the light source unit SU]
As described above, the light source unit SU of the light source unit 41 is configured by arranging a plurality of solid light source units SL in a vertical and horizontal matrix in a plane parallel to the XY plane. FIG. 3 is a schematic view showing the arrangement of the solid-state light source unit SL. FIG. 3 shows a solid-state light source array SA in which a plurality of solid-state light source units SL are arranged on a substrate extending along the ± Y direction.
The light source unit SU is configured by arranging a plurality of such solid light source arrays SA along the ± X direction. In the case of the configuration shown in FIG. 3, three solid light source arrays SA in which five sets of solid light source units SL are arranged along the ± Y direction on one substrate are arranged along the ± X direction. ..

In FIG. 3, the light emitting region of each solid light source unit SL has a substantially rectangular shape with the long side in the ± Y direction, but the shape of the light emitting region of the solid light source unit SL is not limited to this. For example, the shape of the light emitting region may be square, circular or elliptical.
Further, in FIG. 3, the solid light source array SA extending in the ± Y direction is arranged along the ± X direction, but the present invention is not limited to this, and the solid light source array SA extending in the ± X direction is arranged in the ± Y direction. It may be arranged along. Further, in FIG. 3, three solid light source arrays SA are arranged, but the present invention is not limited to this, and any number of solid light source arrays SA may be arranged.

In the light source unit SU configured by arranging a plurality of solid-state light source arrays SA in this way, the length in the ± X direction and the length in the ± Y direction in the region where the blue light BL is emitted may be different. That is, anisotropy may occur in the emission region of the blue light BL in the ± X direction and the ± Y direction. Specifically, in the case of the configuration shown in FIG. 3, the length of the region where the blue light BL is emitted in the ± Y direction is longer than the length in the ± X direction.
Therefore, the luminance distribution of the first light flux emitted from the light source unit SU having anisotropy in the emission region reflects the arrangement form of the light source unit SU. Specifically, the range of the region where the brightness of the blue light BL emitted from the light source unit SU is large is longer in the ± Y direction than in the ± X direction.

Subsequently, when the blue light BL having an anisotropic brightness distribution as described above is incident on the diffuser 45 and the wavelength converter 48, respectively, the diffused light emitted from the diffuser 45 and the wavelength converter 48 are emitted. Consider what kind of brightness distribution the converted light is shown.

First, the diffusion of fluorescent YL in the wavelength converter 48 will be considered. The wavelength conversion element 481 of the wavelength conversion device 48 can generally be regarded as a uniform diffuse reflection surface. Therefore, the diffuse reflection of the fluorescent YL generated by being excited by the third luminous flux incident on the wavelength conversion element 481 can be regarded as so-called Lambertian reflection. Therefore, in the wavelength conversion element 481 of the wavelength conversion device 48, the luminance distribution of the fluorescence YL generated by being excited by the incident third luminous flux is isotropic regardless of the incident angle of the excitation light. Therefore, among the generated luminance distributions of the fluorescent YL, the luminance distribution of the fluorescent YL along an arbitrary first direction parallel to the incident side surface of the wavelength conversion element 481 and the luminance distribution along a second direction different from the first direction. The luminance distributions of the fluorescent YL are almost the same.

Next, the diffusion of blue light BL in the diffuser 45 will be considered. The diffusion layer 451 of the diffusion device 45 can be regarded as a normal diffusion reflection surface. The brightness distribution of diffused light diffused on a normal diffuse reflection surface changes depending on the angle of incidence of the incident light on the diffuse reflection surface. Therefore, the brightness distribution of the diffused light in which the second light flux incident on the diffuser 45 is diffused is not necessarily isotropic. Specifically, the brightness distribution of the diffused light along an arbitrary first direction parallel to the incident side surface of the diffuser layer 451 and the brightness distribution of the diffused light along the second direction different from the first direction are substantially equal to each other. In order to be equal, the following conditions must be met. That is, it is necessary that the incident angles of the incident blue light BL are equal for all the cross sections including the normal of the diffusion layer 451 and the normal passing through the focusing point on the diffusion layer 451.

However, in the actual light source unit 41, since the plurality of solid light source units SL are arranged in a predetermined matrix as described above, the blue light BL emitted from the solid light source unit SL has anisotropy as described above. It may be. In such a case, the brightness distribution of the diffused light diffused by the diffuser 45 is the brightness distribution in the direction along an arbitrary first direction and the brightness in the direction along the second direction different from the first direction. It means that the distribution is different.
Due to the difference between the diffusion characteristics of the diffusion layer 451 of the diffusion device 45 and the diffusion characteristics of the wavelength conversion element 481 of the wavelength conversion device 48 as described above, the brightness distribution of the diffused light of the blue light BL is the brightness of the fluorescence YL. It may differ from the distribution. The difference between the luminance distribution of the diffused light of the blue light BL and the luminance distribution of the fluorescent YL is finally perceived as color unevenness of the illumination light.

[About the incident light on the wavelength converter]
Hereinafter, the third luminous flux emitted from the light source unit SU having the arrangement form shown in FIG. 3 and incident on the wavelength conversion element 481 of the wavelength conversion device 48 will be described with reference to the drawings. FIG. 4A is a cross-sectional view of the third light beam seen from the traveling direction of the central light beam Rc passing through the center of the third light beam on the optical path from the photosynthetic device 50 to the second light collecting element 46. FIG. 4B is a schematic view of the third light flux when viewed from the first direction parallel to the plane orthogonal to the traveling direction of the central ray Rc passing through the center of the third light flux. Further, FIG. 4C shows the third luminous flux viewed from a second direction parallel to the plane orthogonal to the traveling direction of the central ray Rc passing through the center of the third luminous flux and orthogonal to the first direction. It is a schematic diagram of the case.

The third luminous flux incident on the wavelength conversion element 481 of the wavelength conversion device 48 has a luminance distribution having anisotropy corresponding to the arrangement form of the light source unit SU. In the case of FIG. 4A, the third luminous flux has a luminance distribution so as to correspond to the 5 × 3 arrangement form of the light source unit SU shown in FIG.

Subsequently, a case where the third luminous flux on the optical path between the second condensing element 46 and the wavelength conversion device 48 is viewed from a direction parallel to the cross section of FIG. 4A will be described with reference to FIGS. 4B and 4C. .. For the sake of simplicity, in FIGS. 4B and 4C, the second condensing element 46 is represented by a single lens.
The third luminous flux separated by the photosynthetic apparatus 50 is condensed by the second condensing element 46 and incident on the wavelength conversion element 481 of the wavelength conversion apparatus 48. Therefore, among the light rays included in the third light flux, the light rays other than the central light beam Rc have a predetermined incident angle with respect to the wavelength conversion element 481.

First, a case where the third light flux incident on the wavelength conversion element 481 of the wavelength conversion device 48 is viewed from the first direction will be described with reference to FIG. 4B. Here, among the light rays included in the third light beam, the light rays that pass through the position farthest from the central light beam Rc in the ± Y direction are referred to as the first outer peripheral light rays Re1. The angle formed by the central ray Rc and the first outer peripheral ray Re1 when viewed from the first direction is referred to as a first incident angle θ1. As shown in FIG. 4B, when the third light beam is viewed from the first direction, the first incident angle θ1 is the maximum incident angle among the angles formed by each light ray included in the third light beam and the central light beam Rc. ..

Next, a case where the third light flux incident on the wavelength conversion element 481 of the wavelength conversion device 48 is viewed from the second direction orthogonal to the first direction will be described with reference to FIG. 4C. Here, among the light rays included in the third light beam, the light rays that pass through the position farthest from the central light beam Rc in the ± Z direction are referred to as the second outer peripheral light rays Re2. The angle formed by the central ray Rc and the second outer peripheral ray Re2 when viewed from the second direction is referred to as a second incident angle θ2. As shown in FIG. 4C, when the third light beam is viewed from the second direction, the second incident angle θ2 is the maximum incident angle among the angles formed by each light ray included in the third light beam and the central light beam Rc. ..

Here, from FIGS. 4B and 4C, it can be seen that the magnitude of the first incident angle θ1 and the magnitude of the second incident angle θ2 are different. Specifically, the second incident angle θ2 is smaller than the first incident angle θ1. This is due to the anisotropy of the luminance distribution of the third luminous flux corresponding to the arrangement form of the light source unit SU shown in FIG. 4A, and the region where the luminance distribution of the third luminous flux is widened is long. The incident angle to the wavelength conversion element 481 increases in the direction.

[About incident light on the diffuser]
In the present embodiment, the injection surface of the light source unit SU and the wavelength conversion element 481 of the wavelength conversion device 48 have a conjugated relationship. Further, the injection surface of the light source unit SU and the diffusion layer 451 of the diffusion device 45 are also in a conjugated relationship. Therefore, the second luminous flux emitted from the light source unit SU having the arrangement form shown in FIG. 3 and incident on the diffusion layer 451 of the diffuser 45 is the third luminous flux incident on the wavelength conversion element 481 of the wavelength converter 48. Is similar to. Therefore, a detailed description of the second luminous flux incident on the diffusion layer 451 of the diffusion device 45 will be omitted.

[About the shape of the aperture]
In this embodiment, in order to suppress the color unevenness of the illumination light caused by the difference between the brightness distribution of the blue light BL and the brightness distribution of the fluorescence YL, in the present embodiment, the wavelength conversion device 48 and the second condensing element 46 are used. A throttle 47 is arranged on the optical path. As described above, the size of the opening 471 of the diaphragm 47 is formed so as to be smaller than the luminous flux width of the fifth luminous flux, which is the luminous flux of the fluorescent YL emitted from the wavelength conversion device 48, and the diaphragm 47 is formed. A part of the incident fifth luminous flux is shielded.

FIG. 5 is a schematic view showing the shape of the diaphragm 47 in the present embodiment. The diaphragm 47 changes the brightness distribution of the fluorescent YL before and after passing through the diaphragm 47 by restricting a part of the incident luminous flux of the fluorescent YL having an isotropic brightness distribution by Lambertian reflection. Specifically, the diaphragm 47 is arranged so that the luminance distribution of the fluorescent YL substantially matches the luminance distribution of the diffused light of the blue light BL having anisotropy corresponding to the arrangement form of the light source unit SU. Therefore, as shown in FIG. 5, the shape of the opening 471 of the diaphragm 47 is formed so that the fifth light flux passing through the diaphragm 47 has anisotropy. The shape of the opening 471 is a rectangle having two sides parallel to the ± Y direction and two sides parallel to the ± Z direction, and the length L1 of the opening 471 along the ± Y direction is ± Z. It is longer than the length L2 along the direction.

The specific shape of the diaphragm 47 in this embodiment will be described with reference to FIGS. 6A and 6B. FIG. 6A is a schematic view of the fifth and sixth luminous fluxes in the optical path between the second condensing element 46 and the wavelength conversion device 48 when viewed from the first direction. Further, FIG. 6B is a schematic view of the fifth and sixth luminous fluxes in the optical path between the second condensing element 46 and the wavelength conversion device 48 when viewed from the second direction. 6A and 6B represent some of the light rays included in the fifth light flux, which is the light flux of the fluorescent YL emitted from the wavelength conversion element 481 of the wavelength conversion device 48.

The size of the opening 471 of the diaphragm 47 is formed so as to be smaller than the luminous flux width of the fifth luminous flux, which is the luminous flux of the fluorescent YL emitted from the wavelength conversion device 48, and is a part of the fifth luminous flux. Is shaded by the aperture 47. In the present embodiment, the length of the opening 471 of the diaphragm 47 when viewed from the first direction is the length L1 in the ± Y direction. Similarly, the length of the opening 471 of the aperture 47 when viewed from the second direction is the length L2 in the ± Z direction.

Here, the size of the opening 471 of the diaphragm 47 in the present embodiment is the incident of the light ray included in the third light beam when viewed from a certain direction parallel to the plane orthogonal to the traveling direction of the central light ray Rc. The larger the maximum value of the angle is, the longer the opening 471 is formed when viewed from the same direction. That is, the length of each side of the opening 471 is proportional to the magnitude of the incident angle when viewed from the corresponding direction. In the case of the present embodiment, as can be seen from FIGS. 6A and 6B, the length L1 of the opening 471, which is the size of the opening 471 when the diaphragm 47 is viewed from the first direction, makes the diaphragm 47 in the second direction. It is longer than the length L2 of the opening 471, which is the size of the opening 471 when viewed from the above. This is because the magnitude of the first incident angle θ1, which is the maximum incident angle when the third luminous flux is viewed from the first direction, is the maximum incident angle when the third luminous flux is viewed from the second direction. 2 Corresponds to being larger than the magnitude of the incident angle θ2.

Of the fifth luminous flux, the partial luminous flux that has passed through the opening 471 of the diaphragm 47 becomes the sixth luminous flux. The larger the size of the opening 471, the larger the luminous flux can pass through the diaphragm 47, so that the brightness of the fluorescent YL included in the illumination light also increases. By giving anisotropy to the shape of the opening 471 of the aperture 47, the luminous flux of fluorescent YL which is Lambertian reflected by the wavelength conversion element 481 and has an isotropic luminance distribution is a luminous flux having anisotropy in the luminance distribution. Is converted to. Further, when the length of the opening 471 of the diaphragm 47 when viewed from the first direction and when viewed from the second direction is proportional to the magnitude of the incident angle of the third luminous flux, an isotropic luminance distribution is obtained. The luminous flux of the fluorescent YL having the luminous flux is converted into a luminous flux having a luminance distribution equivalent to that in the case of normal diffuse reflection.

In the case of the present embodiment, as shown in FIGS. 4B and 4C, the magnitude of the first incident angle θ1, which is the maximum incident angle when the third light flux is viewed from the first direction, is the third light flux. Is larger than the magnitude of the second incident angle θ2, which is the maximum incident angle when viewed from the second direction. That is, the relationship of θ1> θ2 is satisfied. Therefore, the length L1 of the opening 471 of the diaphragm 47 when viewed from the first direction is longer than the length L2 of the opening 471 of the diaphragm 47 when viewed from the second direction, that is, L1> L2. The diaphragm 47 is formed so as to be.

Further, the value of the ratio L1 / L2 of the length of the opening 471 is equal to the ratio θ1 / θ2 of the incident angle of the third luminous flux, that is, the relational expression of L1 / L2 = θ1 / θ2 is satisfied. It is more preferable to set L1 and L2 to. As a result, the luminance distribution of the sixth luminous flux, which is the partial luminous flux of the fluorescent YL, substantially matches the luminance distribution of the diffused light diffused by the diffuser 45, so that the luminance distribution of the diffused light of the blue light BL and the luminance distribution of the fluorescent YL Color unevenness caused by the difference in brightness distribution can be suppressed.

As described above, according to the light source device 4 and the projector 1 of the present embodiment, the following effects can be obtained.

(1) According to the present embodiment, the shape of the opening 471 of the diaphragm 47 corresponds to the incident angle of the third light flux incident on the wavelength conversion device 48. Specifically, the first incident angle θ1 which is the maximum incident angle when the third luminous flux is viewed from the first direction is from the second incident angle θ2 which is the maximum incident angle when viewed from the second direction. If it is also large, the diaphragm 47 is formed so that the length L1 of the opening 471 when viewed from the first direction is longer than the length L2 of the opening 471 when viewed from the second direction. Therefore, the luminance distribution of the sixth luminous flux emitted from the diaphragm 47 is different from the luminance distribution of the fifth luminous flux incident on the diaphragm 47, and is substantially the same as the luminance distribution of the fourth luminous flux. Therefore, since the luminance distribution of the fourth luminous flux included in the illumination light which is the seventh luminous flux and the luminance distribution of the sixth luminous flux are substantially the same, the homogenizer optical system can be used to detect color unevenness caused by the difference in the luminance distribution. It can be suppressed without adding. As a result, it is possible to reduce the size and cost of the light source device 4.

(2) According to the present embodiment, since the photosynthetic apparatus 50 includes a polarization separating element 51 that transmits one of the p-polarized light and the s-polarized light and reflects the other, the first light flux is generated by the second light flux. The light flux can be separated into a third light flux, and the light flux emitted from one light source unit 41 can be guided to both the diffuser 45 and the wavelength conversion device 48.

(3) According to the present embodiment, the diffusion device 45 and the wavelength conversion device 48 are reflective type, and the photosynthesis device 50 functions as both a separation unit and a synthesis unit. Therefore, as compared with the case where each is provided separately. The number of optical components can be reduced, and the light source device 4 can be further miniaturized and reduced in cost.
(4) According to the present embodiment, the polarization separation element 51 of the photosynthesis apparatus 50 separates the blue light BL by the polarization component, whereas the fluorescence YL does not separate by the polarization component. Therefore, the photosynthetic apparatus 50 can utilize the sixth luminous flux without waste.

(5) According to the present embodiment, since the polarization adjusting device 42 can adjust the ratio of the p-polarized light and the s-polarized light contained in the first luminous flux, the second luminous flux and the third luminous flux separated by the photosynthetic apparatus 50 The ratio of can be changed. Therefore, the ratio of the fourth luminous flux composed of the blue light BL and the sixth luminous flux composed of the fluorescent YL can be adjusted, and the white balance of the illumination light can be adjusted.

(6) According to the present embodiment, the ratio of p-polarized light and s-polarized light contained in the blue light BL emitted from the polarization adjusting device 42 is set relative to the first retardation plate 421 by the second retardation plate 422. It can be changed by adjusting the angle. Therefore, the white balance of the illumination light can be adjusted with a simple configuration.

[Other Embodiments]
In the above embodiment, the projector 1 is provided with an optical modulation device 343 (343R, 343G, 343B) each having a liquid crystal panel. However, the present invention is not limited to this, and the present invention can be applied to a projector provided with two or less or four or more optical modulation devices.
Further, in the image projection device 3, the layout of each optical component can be changed as appropriate, and some optical components may be omitted. For example, in the above embodiment, the photosynthetic apparatus 50 has both a function as a separation unit and a function as a synthesis unit, but the separation unit and the synthesis unit may be composed of separate optical elements. In this case, the diffuser 45 and the wavelength conversion device 48 may adopt a transmission type, and the third retardation plate 43 becomes unnecessary.

In the above embodiment, the light modulation device 343 has a configuration in which the light incident surface and the light emitting surface have different transmissive liquid crystal panels. However, the present invention is not limited to this, and the optical modulation device 343 may have a configuration having a reflective liquid crystal panel in which the light incident surface and the light emitting surface are the same. Further, if it is an optical modulation device capable of forming an image according to image information by modulating an incident light beam, a device using a micromirror, for example, a device using a DMD (Digital Micromirror Device) or the like, other than liquid crystal An optical modulator may be used.

In the above embodiment, the projection optical device 35 is configured to project the image light incident from the image forming device 34 along the −Z direction along the same −Z direction. However, the present invention is not limited to this, and an aspherical mirror is arranged on the downstream side of the optical path in the projection optical device 35 so that the image light incident from the image forming apparatus 34 along the −Z direction is folded back in another direction. May be good.

In the above embodiment, an example in which the light source device 4 of the present invention is applied to the projector 1 is given. However, the present invention is not limited to this, and the light source device 4 according to the present invention may be adopted, for example, for lighting equipment, headlights of automobiles, and the like.

The contents derived from the embodiment are described below.

The light source device includes a light source that emits a first luminous flux belonging to the first wavelength band, a separation unit that separates the first luminous flux into a second luminous flux and a third luminous flux, and the second luminous flux. A diffuser that ejects a fourth luminous flux in which a light flux is incident and diffuses the incident second luminous flux, and the third luminous flux is incident and excited by the incident third luminous flux, and the first A wavelength conversion device that emits a fifth light flux belonging to a second wavelength band different from the wavelength band of the above, and a sixth light flux that is a partial light flux of the fifth light beam incident on the fifth light source and emits a sixth light flux. It is provided with a throttle having an opening, a compositing unit that combines the fourth light flux and the sixth light flux, and emits a seventh light flux, and is centered on a light beam passing through the center of the third light flux. When viewed from the first direction parallel to the plane orthogonal to the central light beam, the maximum angle between the central light beam and the light beam included in the third luminous flux is defined as the first incident angle. When viewed from a second direction parallel to the plane orthogonal to the central light beam and orthogonal to the first direction, the maximum angle formed by the central light beam and the light beam included in the third light flux is the first. When the first incident angle is larger than the second incident angle, the length of the opening seen from the first direction is longer than the length of the opening seen from the second direction. It is characterized by that.

According to this configuration, the diaphragm blocks a part of the fifth luminous flux and emits a sixth luminous flux which is a partial luminous flux of the fifth luminous flux. At this time, the shape of the opening of the diaphragm corresponds to the incident angle of the third light flux incident on the wavelength conversion device. Specifically, the maximum incident angle when the third light beam is viewed from the first direction is defined as the first incident angle, and the maximum incident angle when the third light beam is viewed from the second direction orthogonal to the first direction. When the angle is the second incident angle and the first incident angle is larger than the second incident angle, the length of the opening when viewed from the first direction is larger than the length of the opening when viewed from the second direction. The throttle is formed so that it becomes longer. Therefore, the luminance distribution of the sixth luminous flux emitted from the diaphragm is different from the luminance distribution of the fifth luminous flux incident on the diaphragm, and is substantially the same as the luminance distribution of the fourth luminous flux. Therefore, since the luminance distribution of the fourth luminous flux included in the seventh luminous flux and the luminance distribution of the sixth luminous flux are substantially the same, the color unevenness caused by the difference in the luminance distribution can be eliminated without adding a homogenizer optical system. Can be suppressed. As a result, the light source device can be miniaturized.

In this light source device, the separation unit comprises a polarization separation element that transmits one of the light flux of the first polarization component and the light flux of the second polarization component different from the first polarization component and reflects the other. It is desirable that the first light beam is separated into the second light beam and the third light beam by the polarization separating element.

According to this configuration, since the separation unit includes a polarization separation element that transmits one of the first polarization component and the second polarization component and reflects the other, the first light flux is transmitted to the second. The light flux can be separated into a third light flux, and the light flux emitted from only one light source can be guided to both the diffuser and the wavelength conversion device.

In this light source device, the diffuser and the wavelength converter are of a reflection type, and the separation unit also functions as the synthesizer, and the fourth light flux reflected by the diffuser and the wavelength converter It is desirable that the sixth light beam reflected by the polarizing element and transmitted through the aperture is combined with the polarization separating element.

According to this configuration, the diffuser and the wavelength converter are reflective, and the separation unit also functions as a synthesis unit. Therefore, the number of optical components is larger than that in the case where the separation unit and the composition unit are separately provided. Can be reduced and the light source device can be miniaturized.

In this light source device, it is desirable that the polarization separating element does not separate the light flux belonging to the second wavelength band by the polarization component.

According to this configuration, the polarization separating element does not separate the sixth luminous flux belonging to the second wavelength band by its polarization component. Therefore, the synthesis unit can utilize the sixth luminous flux belonging to the second wavelength band without waste.

In this light source device, it is desirable to include a polarization adjusting device which is arranged on an optical path between the light source and the separation portion and adjusts the ratio of the first polarization component contained in the first light flux.

According to this configuration, since the polarization adjusting device can adjust the ratio of the first polarization component contained in the first light flux, the ratio of the second light flux and the third light flux separated by the separation portion can be changed. Can be done. Therefore, the ratio of the fourth luminous flux belonging to the first wavelength band and the sixth luminous flux belonging to the second wavelength band can be adjusted, and the white balance of the illumination light can be adjusted.

In this light source device, the polarization adjusting device is located between a first retardation plate arranged on an optical path between the light source and the separation portion, the first retardation plate, and the separation portion. A second retardation plate arranged on an optical path is provided, and at least one of the first retardation plate and the second retardation plate can adjust the angle in a plane orthogonal to the first light source. It is desirable to be provided.

According to this configuration, the ratio of the first polarization component contained in the first light flux emitted from the polarization adjusting device is adjusted by adjusting the relative angle of the second retardation plate with respect to the first retardation plate. Can be changed. Therefore, the white balance of the illumination light can be adjusted with a simple configuration.

The projector includes the light source device, an image forming device that modulates the seventh luminous flux emitted from the light source device to form an image, and a projection optical device that projects the image formed by the image forming device. It is characterized by having.

According to this configuration, the color unevenness caused by the inconsistency between the luminance distribution of the fourth luminous flux belonging to the first wavelength band and the luminance distribution of the sixth luminous flux belonging to the second wavelength band is suppressed, and the size is small. A projector can be provided.

1 ... Projector, 2 ... Exterior housing, 3 ... Image projection device, 31 ... Uniformization device, 32 ... Color separation device, 33 ... Relay device, 34 ... Image forming device, 35 ... Projection optical device, 36 ... For optical components Housing, 4 ... light source device, 41 ... light source unit, 411 ... solid light source, 412 ... microlens, 413 ... heat dissipation member, 42 ... polarization adjusting device, 421 ... first phase difference plate, 422 ... second phase difference plate, 43 ... 3rd phase difference plate, 44 ... 1st light source element, 441-443 ... lens, 45 ... diffuser, 451 ... diffusion layer, 452 ... substrate, 46 ... 2nd light source element, 461-463 ... lens, 47 ... aperture, 471 ... opening, 48 ... wavelength conversion device, 481 ... wavelength conversion element, 482 ... support, 483 ... rotating device, 49 ... fourth retardation plate, 50 ... photosynthesis device, 51 ... polarization separation element, Ax ... Illumination optical axis, Ax1 ... 1st illumination optical axis, Ax2 ... 2nd illumination optical axis, BL ... Blue light, Rc ... Central ray, Re1 ... 1st outer peripheral ray, Re2 ... Second outer peripheral ray, SA ... Solid light source Array, SL ... Solid light source unit, SU ... Light source unit, YL ... Fluorescent.

Claims (7)

A light source that emits a first luminous flux belonging to the first wavelength band,
A separation unit that separates the first luminous flux into a second luminous flux and a third luminous flux,
A diffuser in which the second luminous flux is incident and emits a fourth luminous flux that diffuses the incident second luminous flux.
A wavelength conversion device in which the third luminous flux is incident, excited by the incident third luminous flux, and emits a fifth luminous flux belonging to a second wavelength band different from the first wavelength band.
A diaphragm in which the fifth luminous flux is incident and an opening for emitting a sixth luminous flux, which is a partial luminous flux of the fifth luminous flux, is formed.
A compositing unit that synthesizes the fourth luminous flux and the sixth luminous flux and emits a seventh luminous flux is provided.
A ray passing through the center of the third luminous flux is defined as a central ray.
When viewed from the first direction parallel to the plane orthogonal to the central ray, the maximum angle between the central ray and the ray included in the third light beam is defined as the first incident angle.
When viewed from a second direction parallel to the plane orthogonal to the central ray and orthogonal to the first direction, the maximum angle among the angles formed by the central ray and the light rays contained in the third light beam is the first. 2 incident angles
When the first incident angle is larger than the second incident angle, the length of the opening seen from the first direction is longer than the length of the opening seen from the second direction. Light source device. The separation unit includes a polarization separation element that transmits one of the light flux of the first polarization component and the light flux of the second polarization component different from the first polarization component and reflects the other, and the polarization separation. The light source device according to claim 1, wherein the first light flux is separated into the second light flux and the third light flux by an element. The diffuser and the wavelength converter are reflective and are reflective.
The separation unit also functions as the synthesis unit, and separates the fourth light flux reflected by the diffuser and the sixth light flux reflected by the wavelength conversion device and transmitted through the aperture. The light source device according to claim 2, wherein the light source device is synthesized by an element. The light source device according to claim 3, wherein the polarization separating element does not separate a light flux belonging to the second wavelength band by a polarization component. 2. To the present invention, the present invention comprises a polarization adjusting device arranged on an optical path between the light source and the separation portion and adjusting the ratio of the first polarization component contained in the first light flux. The light source device according to any one of 4. The polarization adjusting device is
A first retardation plate arranged on an optical path between the light source and the separation portion,
A second retardation plate arranged on an optical path between the first retardation plate and the separation portion is provided.
The light source device according to claim 5, wherein at least one of the first retardation plate and the second retardation plate is provided with an adjustable angle in a plane orthogonal to the first luminous flux. The light source device according to any one of claims 1 to 6.
An image forming apparatus that modulates the seventh luminous flux emitted from the light source apparatus to form an image, and an image forming apparatus.
A projector including a projection optical device for projecting the image formed by the image forming apparatus.

Images