WO2018173212A1

WO2018173212A1 - Light source device, method for controlling light source device, program, and projection-type display device

Info

Publication number: WO2018173212A1
Application number: PCT/JP2017/011809
Authority: WO
Inventors: 慎一郎近久
Original assignee: Ｎｅｃディスプレイソリューションズ株式会社
Priority date: 2017-03-23
Filing date: 2017-03-23
Publication date: 2018-09-27
Also published as: CN212031908U

Abstract

The purpose of the present invention is to efficiently obtain the light amount taking polarization efficiency into account. This invention is provided with: an excitation light source (43) for emitting excitation light; a phosphor (44) for releasing unpolarized fluorescent light when irradiated with the excitation light; a blue light source (45) for emitting linearly polarized blue light; a dichroic mirror (1g) for reflecting the excitation light emitted from the excitation light source and emitting the excitation light towards the phosphor, transmitting the unpolarized fluorescent light released from the phosphor on the basis of emission of the excitation light, and reflecting the linearly polarized blue light emitted from the blue light source in the same direction as that in which the unpolarized fluorescent light is transmitted; and a polarization conversion part (46), which converts the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror to the same polarization as that of the linearly polarized blue light, and which does not convert the polarization of the linearly polarized blue light reflected by the dichroic mirror.

Description

Light source device, light source device control method, program, and projection display device

The present invention relates to a light source device, a light source device control method, a program, and a projection display device, and more particularly, a light source device including a plurality of light sources each emitting light of a different color, a light source device control method, and a program. The present invention also relates to a projection display device.

As a projection method of a projection display device (hereinafter also referred to as a projector) that projects an image on a screen, a liquid crystal method or a DLP (registered trademark) method is known. As a light source of a projector having these methods, a technique using a laser in addition to an LED (Light Emitting Diode) and a lamp is attracting attention. In particular, lasers are attracting attention as light sources that replace lamps because they have a longer life than lamps and have high reliability.

Patent Document 1 discloses the following technology. The light emitted from the light source section passes through the integrator lens composed of the first lens array and the second lens array so as to maintain the brightness to the end of the display image, and then passes through the polarization conversion element and the condenser lens. And separated for each wavelength region.

JP 2014-186115 A

Some recent projectors use a plurality of light sources LD (Laser Diodes) in the light source section to use the light sources LD for excitation light and blue light of a yellow phosphor. When the projection method of the projector is a liquid crystal method, it is necessary to align the polarization of light irradiated to the liquid crystal using a polarization conversion element. In this case, it is required to efficiently obtain the light amount in consideration of the polarization efficiency.

In Patent Document 1, when the light in the blue wavelength region is reflected on the surface of the wheel, a function of rotating or disturbing the polarization is provided so that the light is efficiently reflected by the first dichroic mirror. However, no consideration is given to the polarization of light emitted from the first light source or the second light source. Therefore, there is a problem that the amount of light cannot be obtained efficiently when the polarized light is aligned using the polarization conversion element after the light emitted from the light source unit is generated.

An object of the present invention is to provide a light source device, a light source device control method, a program, and a projection display device that can solve the problem of efficiently obtaining a light quantity in consideration of polarization efficiency.

The light source device of the present invention includes an excitation light source that emits excitation light, a phosphor that emits non-polarized fluorescence when irradiated with the excitation light, a blue light source that emits linearly polarized blue light, and the excitation Reflecting the excitation light emitted from a light source and irradiating the phosphor toward the phosphor, transmitting the unpolarized fluorescence emitted from the phosphor based on the irradiation of the excitation light, and irradiating from the blue light source The dichroic mirror that reflects the linearly polarized blue light in the same direction as the non-polarized fluorescent light is transmitted, and the non-polarized fluorescent light that has passed through the dichroic mirror is the linearly polarized blue light. Polarization conversion means for converting into the same polarization and not converting the polarization of the linearly polarized blue light reflected by the dichroic mirror.

Also, a projection display device of the present invention includes the light source device.

Furthermore, the control method of the light source device of the present invention includes an excitation light source that irradiates excitation light, a phosphor that emits non-polarized fluorescence when irradiated with the excitation light, and a blue color that irradiates linearly polarized blue light. Reflecting the excitation light emitted from the light source and the excitation light source toward the phosphor and transmitting the unpolarized fluorescence emitted from the phosphor based on the irradiation of the excitation light; And a dichroic mirror that reflects the linearly polarized blue light emitted from the blue light source in the same direction as the non-polarized fluorescence is transmitted. Converting the transmitted polarization of the non-polarized fluorescence into the same polarization as the linearly polarized blue light, and not converting the polarization of the linearly polarized blue light reflected by the dichroic mirror.

According to the present invention, the amount of light can be obtained efficiently in consideration of the polarization efficiency.

It is a schematic diagram which shows an example of a structure of the light source device by 1st Embodiment of this invention. It is a schematic diagram which shows the light source image irradiated in the state which does not have a diffusion plate in the fluorescence excitation optical system of 1st Embodiment. It is a schematic diagram which shows the light source image irradiated in the state which has a diffusion plate in the fluorescence excitation optical system of 1st Embodiment. It is a schematic diagram which shows an example of the phosphor wheel used for the light source device shown in FIG. It is a characteristic view which shows the spectral reflection characteristic of P polarized light of a dichroic mirror. It is a characteristic view which shows the spectral reflection characteristic of S polarization of a dichroic mirror. It is a characteristic view which shows the spectral transmission characteristic of a dichroic mirror. It is a typical block diagram which shows the structure of the polarization conversion element of a light source device. It is a typical sectional view for explaining operation of a polarization conversion element. It is a characteristic view which shows the spectral transmission characteristic with respect to S polarization input light of a polarization conversion element. It is a characteristic view which shows the spectral transmission characteristic with respect to P polarization input light of a polarization conversion element. It is a flowchart which shows operation | movement of the light source device by 1st Embodiment. It is a schematic block diagram which shows an example of a projection type display apparatus provided with the light source device by 1st Embodiment. It is a schematic diagram which shows the structure of the light source device by 2nd Embodiment of this invention.

Embodiments of the present invention will be described below with reference to the drawings. In addition, the unidirectional arrow in the figure demonstrated below shows the flow of a certain signal (data) simply, and does not exclude bidirectionality.
(First embodiment)
First, a schematic configuration of the light source device according to the first embodiment of the present invention will be described.
FIG. 1 is a schematic diagram illustrating a configuration of a light source device according to the first embodiment.
As shown in FIG. 1, the light source device 40 according to the present embodiment includes a fluorescence excitation optical system 1, a blue light path 2, and a fluorescence / blue common light path 3.
The fluorescence excitation optical system 1 includes a blue LD array 1a, a blue LD collimator lens 1b,

lenses

1c, 1d and 1e, a diffusion plate 1f, a dichroic mirror 1g,

lenses

1h and 1i, and a phosphor wheel 1j. have.
The blue optical path 2 includes a blue LD array 2a, a blue LD collimator lens 2b, a diffusion plate 2c, and

lenses

2d and 2e.
The fluorescence / blue common optical path 3 includes

lenses

3a and 3b,

integrators

3c and 3d, and a polarization conversion element 3e.

The elements constituting the fluorescence excitation optical system 1, the blue light path 2, and the fluorescence / blue common light path 3 forming the light source device 40 according to the present embodiment will be described below.
The blue LD array 1a of the fluorescence excitation optical system 1 has excitation light sources arranged in an array. The blue LD collimator lens 1b corrects the aberration so that the light beam emitted from the blue LD array 1a as the light source becomes parallel light at the focal point. The

lenses

1c, 1d, and 1e collect the excitation light that has been aberration-corrected into parallel light by the blue LD collimator lens 1b. The diffusion plate 1f diffuses the excitation light collected by the

lenses

1c, 1d, and 1e. The dichroic mirror 1g reflects the excitation light diffused by the diffusion plate 1f in the direction of the phosphor wheel 1j. The

lenses

1h and 1i collect the excitation light reflected by the dichroic mirror 1g on the phosphor wheel 1j. In addition, the

lenses

1h and 1i make yellow fluorescence emitted from the phosphor wheel 1j incident on the dichroic mirror 1g. The phosphor wheel 1j is a disk-shaped wheel in which a yellow phosphor region that emits yellow fluorescence when excited by excitation light is formed in an annular shape. The configuration of the phosphor wheel 1j will be described later.

The blue LD array 2a in the blue light path 2 has blue light sources arranged in an array. The blue LD collimator lens 2b corrects the aberration so that the light beam emitted from the blue LD array 2a as the light source becomes parallel light at the focal point. The diffusion plate 2c diffuses the blue LD light whose aberration is corrected by the blue LD collimator lens 2b. The

lenses

2d and 2e collect the blue LD light diffused by the diffusion plate 2c. The dichroic mirror 1 g reflects the blue LD light collected by the

lenses

2 d and 2 e in the direction of the fluorescence / blue common optical path 3.
The dichroic mirror 1 g in the fluorescence / blue common optical path 3 synthesizes the yellow fluorescence emitted from the phosphor wheel 1 j and the blue LD light reflected in the direction of the fluorescence / blue common optical path 3. The

lenses

3a and 3b collect the synthesized yellow fluorescence and blue LD light. The

integrators

3c and 3d make the light intensity of the combined light of the yellow fluorescent light and the blue LD light collected by the

lenses

3a and 3b uniform. The polarization conversion element 3e aligns the polarization of the combined light of the yellow fluorescent light and the blue LD light whose light intensity is uniform by the

integrators

3c and 3d in a certain polarization direction. The polarization conversion element 3e will be described later.

Next, the operation of the optical system of the light source device according to the present embodiment will be specifically described. In the fluorescence excitation optical system 1, the polarization of the light beam emitted from the blue LD array 1a in which blue LDs (excitation light sources) are arranged in an array is linear polarization perpendicular to the paper surface of FIG. The reason why the light beam emitted from the blue LD array 1a is linearly polarized light perpendicular to the paper surface of FIG. 1 will be described later. When the light beam emitted from the blue LD array 1a is condensed on the phosphor wheel 1j in the optical path of the fluorescence excitation optical system 1, it is necessary to suppress the temperature rise of the phosphor wheel 1j due to the irradiation of the excitation light. For this reason, the intensity distribution of the excitation light irradiated to the phosphor wheel 1j is made uniform by using the diffusion plate 1f. This point will be described with reference to FIG. FIG. 2A is a schematic diagram illustrating a light source image irradiated with no diffusion plate on the phosphor wheel, and FIG. 2B is a schematic diagram illustrating a light source image irradiated with a diffusion plate on the phosphor wheel. FIG.
By avoiding the irradiation state where the light source image as shown in FIG. 2A is concentrated at one point and through the diffuser plate 1f, the light source image has a condensing shape with a certain width as shown in FIG. 2B. . In order to obtain the same effect as that of the diffusing plate 1f, a homogenizer, a light tunnel, a rod integrator, or the like, which is an optical element that generates a laser beam with a uniform light intensity distribution, can be substituted.

The laser light emitted from the blue LD array 1a becomes parallel light by passing through the blue LD collimator lens 1b. The excitation light that has become parallel by passing through the collimator lens 1b is collected by using the

lens groups

1c, 1d, and 1e. The excitation light condensed by the

lens groups

1c, 1d, and 1e is diffused by using the diffusion plate 1f described above. The diffused excitation light is reflected in the direction of the phosphor wheel 1j by using the dichroic mirror 1g. The dichroic mirror 1g has a characteristic of reflecting blue light and transmitting yellow light.

In the present embodiment, an adjustment mechanism is provided in the lens 1e in order to absorb an attachment error of a lens or the like disposed between the blue LD array 1a and the phosphor wheel 1j. In addition, when there is no problem in terms of mechanism restrictions, it is preferable to provide an adjustment mechanism also in the optical axis direction of the phosphor wheel 1j. By using the adjustment mechanism of the lens 1e, the light emission position of yellow fluorescence emitted from the phosphor wheel 1j can be adjusted. Further, the amount of yellow fluorescent light emitted from the phosphor wheel 1j can be adjusted by using an adjusting mechanism provided in the optical axis direction of the phosphor wheel 1j. Thereby, a stable and highly efficient light source device can be obtained.

The laser beam emitted from the blue LD array 1a is condensed on the phosphor wheel 1j through a phosphor wheel collimator lens (not shown). Here, the phosphor wheel 1j will be described with reference to FIG. FIG. 3 is a schematic diagram showing an example of a phosphor wheel used in the light source device shown in FIG.
The phosphor wheel 1j has a hollow disk shape when viewed from a direction perpendicular to the rotation surface. And the area | region of the yellow fluorescent substance 6 is formed cyclically | annularly. The center of the motor shaft 7 of the phosphor wheel 1j is attached to a rotation shaft of a motor (not shown). The phosphor wheel 1j rotates about the center of the motor shaft 7 to which the rotation shaft of a motor (not shown) is attached. By rotating the phosphor wheel 1j, it is possible to mitigate the temperature rise caused by the excitation light being applied to the region of the yellow phosphor 6. When the phosphor wheel 1j has a sufficient cooling function, the phosphor wheel 1j may not be rotated.

When the excitation light enters the phosphor wheel 1j and enters the yellow phosphor 6 region, yellow fluorescence is emitted from the phosphor wheel 1j. The yellow fluorescent light passes through the

lenses

1i and 1h and enters the dichroic mirror 1g. The yellow fluorescence emitted from the phosphor wheel 1j is Lambert diffused light having ideal diffuse reflection properties. Lumbard diffused light is natural light with no polarization characteristics. Here, S-polarized light, which is polarized light perpendicular to the plane of incidence on the optical element, has better reflection characteristics and angle dependency than P-polarized light, which is polarized parallel to the plane of incidence on the optical element. The polarization characteristic is used. This point will be described with reference to FIGS. 4 shows the P-polarized spectral reflection characteristic of the dichroic mirror, and FIG. 5 shows the S-polarized spectral reflection characteristic of the dichroic mirror.
Comparing FIG. 4 and FIG. 5, it can be seen that the reflectance of S-polarized light is closer to 100% than that of P-polarized light in the blue wavelength range of 420 nm to 500 nm.
The transmittance of the dichroic mirror 1g in the range of 570 nm to 590 nm, which is the wavelength of yellow fluorescence, is approximately 100% as shown in FIG. FIG. 6 shows the spectral transmission characteristics of the dichroic mirror.
Accordingly, the yellow fluorescent light is transmitted through the dichroic mirror 1g and condensed using the

lenses

3a and 3b. Thereafter, the yellow fluorescent light is made uniform in the light intensity of the light flux in the

integrators

3c and 3d and is incident on the polarization conversion element 3e.

On the other hand, in the blue optical path 2, the polarization of the light emitted from the blue LD array 2a in which the blue LDs are arranged in an array is also the same for the S-polarized light than the P-polarized light, as described above with reference to FIGS. It is linearly polarized light perpendicular to the paper surface of FIG. 1 by utilizing the property on polarization that the reflection property and the angle dependency are good. The light emitted from the blue LD array 2a is (1) incident as s-polarized light on the dichroic mirror 1g and reflected. Further, the light beam emitted from the blue LD array 2a is incident and reflected as S-polarized light on a polarization separation film 51 (2) of the polarization conversion element 3e described later.
Diffusion plate 2c and

lenses

2d and 2e, which are dedicated parts for blue optical path 2, emit blue LD efficiently by applying a coating specialized for S-polarized light in the wavelength region (frequency band) of blue LD used. can do. An example of the coating includes an anti-reflection (AR) film.
In the blue light path 2, emitting the light beam of the blue LD as it is is that the coherent light (light having the same phase) is directly irradiated to the outside. If it does so, it may affect a human eye etc., and there is a problem in safety. In addition, when the blue LD is scattered by a random medium, a bright and dark speckle pattern (speckle) is generated, and when speckle spots become large, the image quality of the projector may be affected.

In order to solve these problems, a diffuser plate 2c is disposed in the blue optical path 2 to spatially relieve coherency and ensure safety, and to improve speckle spots. In addition, disposing a diffusion plate in the fluorescence / blue common optical path 3 leads to a reduction in the amount of yellow fluorescence emitted from the phosphor wheel 1j. Therefore, the diffusing plate 2c is preferably disposed between the blue LD array 2a and the dichroic mirror 1g. Depending on the image quality required for the projector, a plurality of diffusion plates 2c are arranged, or the diffusion plate 2c is physically moved by vibrating or rotating to reduce the coherency. You may make it do. In the present embodiment, an adjustment mechanism is provided in the blue LD collimator lens 2d in order to absorb attachment errors of members disposed between the blue LD array 2a and the lens 3b.
Thus, by providing an adjustment mechanism in each optical path of the fluorescence excitation optical system 1 and the blue light path 2, the light beam is efficiently transmitted, and between the fluorescence excitation optical system 1 and the blue light path 2. Luminance spots caused by the optical path difference can be reduced.

Next, the polarization conversion element will be described with reference to FIGS.
First, the configuration of the polarization conversion element of the light source device will be described with reference to FIG. FIG. 7 is a schematic block diagram illustrating the configuration of the polarization conversion element of the light source device. The light source device 40 illustrated in FIG. 7 includes a light emitting element 41, a collimator lens 42, and a polarization conversion element 3e. The polarization conversion element 3e includes a transparent member 53 provided with a polarization separation film 51 and a reflection film 52, and a λ / 2 phase difference plate 56.
The light emitting element 41 emits non-polarized light (101). The collimator lens 42 collimates the light from the light emitting element 41 as much as possible. Non-polarized light (101) from the collimator lens 42 enters the transparent member 53, and is converted into P-polarized light (102) traveling straight in the polarization separation film 51 and S-polarized light (103) reflected in the orthogonal direction. To be separated. The optical path of the S-polarized light (103) is bent by the reflective film 52, and the traveling direction becomes parallel to the P-polarized light (102). The P-polarized light (102) transmitted through the polarization separation film 51 of the transparent member 53 is rotated by 90 ° by the λ / 2 phase difference plate 56, and the S-polarized light emitted from the reflective film 52 of the transparent member 53 ( 103) and S-polarized light (103) having the same polarization direction. That is, the non-polarized light (101) emitted from the light emitting element 41 is aligned with the S-polarized linearly polarized light (103) using the polarization conversion element 3e. By arranging a large number of polarization conversion elements 3e shown in FIG. 7, a brighter light source device 40 can be configured.

FIG. 8 is a schematic cross-sectional view for explaining the operation of the polarization conversion element. As shown in FIG. 8, the polarization conversion element 3 e includes a plurality of polarization separation films 51, a plurality of reflection films 52, and a transparent member 53 that is formed in a rectangular flat plate shape with the polarization separation films 51 and the reflection films 52 formed thereon. , And a plurality of λ / 2 retardation films 56 provided with a λ / 2 retardation film.
The polarization separation film 51 and the reflection film 52 form one set, and the polarization separation film 51 is arranged to be inclined with respect to the incident light, and separates the incident light beam into two types of linearly polarized light beams. The reflection film 52 is arranged in parallel to the reflected light side of the polarization separation film 51 and reflects one polarized light beam separated and reflected by the polarization separation film 51.
The λ / 2 retardation film of the λ / 2 retardation film 56 is provided on the light beam exit side of the transparent member 53, converts the polarization axis of one of the polarized light beams, and aligns it with the polarization axis of the other polarized light beam.

In the polarization conversion element 3e, the polarization separation films 51 and the reflection films 52 are arranged so that the polarization separation films 51 and the reflection films 52 are symmetrically positioned on both sides of the center line of the polarization conversion element 3e. Yes.
In FIG. 8, a light beam of non-polarized light from a light source collimated as incident light enters from the incident surface 4 side of the polarization conversion element 3e and reaches the polarization separation film 51. In this case, the polarization separation film 51 is configured to transmit the P-polarized linearly polarized light beam and reflect the S-polarized linearly polarized light beam. The optical path of the S-polarized light reflected by the polarization separation film 51 is bent by the reflective film 52, and the traveling direction becomes parallel to the P-polarized light. The P-polarized linearly polarized light beam transmitted through the polarization separation film 51 is converted into S-polarized light by passing through the λ / 2 phase difference plate 56. That is, the unpolarized light incident from the incident surface 4 is aligned with the S-polarized linearly polarized light using the polarization conversion element 3e.

Returning to FIG. 1, the blue LD reflected by the dichroic mirror 1g is combined with the yellow fluorescence emitted from the phosphor wheel 1j and transmitted through the dichroic mirror 1g. Hereinafter, the synthesized light is also referred to as synthesized light.
The polarization of the light beam of the blue LD emitted from the blue LD array 2a as the light source is linearly polarized light perpendicular to the paper surface of FIG. The blue LD light beam is incident on the dichroic mirror 1g as S-polarized light, and is reflected by the dichroic mirror 1g with S-polarized light. Then, the blue LD reflected by the dichroic mirror 1g enters the lens 3a, the lens 3b, and the

integrators

3c and 3d in the S-polarized state in the direction of the fluorescence / blue common optical path 3.
The blue LD is condensed using the

lenses

3a and 3b, and then the light intensity of the light beam is made uniform in the

integrators

3c and 3d, and is incident on the polarization conversion element 3e. Then, the blue LD is incident on the polarization separation film 51 constituting the polarization conversion element 3e as S-polarized light and reflected. Further, the blue LD is reflected by the polarization separation film 51 constituting the polarization conversion element 3e, and further reflected by the reflection film 52 constituting the polarization conversion element 3e. At this time, the polarization of the blue LD is not converted, and the state of S polarization is maintained.
On the other hand, yellow fluorescence is incident on the polarization separation film 51 constituting the polarization conversion element 3e as polarized light having both an S-polarized component and a P-polarized component. Of the yellow fluorescence, the S-polarized component is not converted in polarization as in the case of the blue LD, and maintains the S-polarized state. Among the yellow fluorescent light, the P-polarized component is transmitted through the polarization separation film 51, and the polarized light is converted by the λ / 2 phase difference plate 56 constituting the polarization conversion element 3e. That is, the P-polarized component of the yellow fluorescence is polarized and converted to S-polarized light.
As a result, the blue LD and yellow fluorescence polarized light emitted from the polarization conversion element 3e become the same linearly polarized light (S-polarized light) over the entire spectrum.

Thus, it is preferable that the polarized light of the blue LD incident on the polarization separation film 51 of the polarization conversion element 3e is at least S-polarized light. For example, if the polarization of the blue LD incident on the polarization separation film 51 of the polarization conversion element 3e is P-polarization, the loss of light amount is caused by the absorption of the blue LD by the polarization separation film 51 when passing through the polarization separation film 51. appear. Further, a loss of light amount occurs when the light passes through the λ / 2 phase difference plate 56. Therefore, when the polarization of the blue LD is S-polarized light, a light source device with low transmission loss and high transmission efficiency can be realized.
Further, since the S-polarized light is more advantageous in terms of the angle dependency, the blue LD light beam is also incident on the polarization separation film 51 of the polarization conversion element 3e as S-polarized light and is reflected. Thus, a light source device with higher transmission efficiency can be obtained. Since the diffusing plate 2c is provided in the blue optical path 2, the incident angle has a width of about several degrees to several tens of degrees. Here, the spectral transmission characteristics of the S-polarized light and the P-polarized light of the polarization conversion element will be described with reference to FIGS. 9 and 10. FIG. 9 shows spectral transmission characteristics of the polarization conversion element with respect to S-polarized input light. FIG. 10 shows spectral transmission characteristics of the polarization conversion element with respect to P-polarized input light.
As shown in FIGS. 9 and 10, the transmittance of S-polarized light is higher than that of P-polarized light in the wavelength region of blue LD (in the range of 420 nm to 500 nm) and in the wavelength region of yellow fluorescence (in the range of 570 nm to 590 nm). It can be seen that it exceeds 90%. Therefore, when a light beam is incident as P-polarized light on the polarization separation film 51 of the polarization conversion element 3e, it is affected by the angle dependency of the polarization conversion element 3e. Therefore, a light source device with higher transmission efficiency can be obtained by making it incident on the polarization separation film 51 of the polarization conversion element 3e as S-polarized light.

Next, the operation of the light source device according to the first embodiment will be described. FIG. 11 is a flowchart showing the operation of the light source device according to the first embodiment.
In the process of step S121, the blue LD array 1a of the fluorescence excitation optical system 1 emits excitation light. The blue LD array 2a in the blue optical path 2 irradiates the incident surface of the dichroic mirror 1g with blue LD that is linearly polarized light perpendicular to the paper surface of FIG.
In the process of step S122, the dichroic mirror 1g reflects the excitation light in the direction of the phosphor wheel 1j. The dichroic mirror 1g transmits yellow fluorescence emitted from the phosphor wheel 1j. The dichroic mirror 1g reflects the blue LD incident as S-polarized light on the incident surface of the dichroic mirror 1g in the same direction as the direction in which the yellow fluorescence is transmitted.
In the process of step S123, the yellow fluorescent light and the blue LD are collected by the

lenses

3a and 3b, and the light intensity of the light beam is made uniform by the

integrators

3c and 3d.
In the process of step S124, the polarization conversion element 3e reflects the blue LD incident as S-polarized light on the incident surface of the polarization separation film 51 constituting the polarization conversion element 3e by the polarization separation film 51 and reflects it by the reflection film 52. To do. The polarization conversion element 3 e reflects the S-polarized component of yellow fluorescence by the polarization separation film 51 and reflects it by the reflection film 52. The P-polarized component of yellow fluorescence is transmitted through the polarization conversion film 51 and converted into S-polarized light by the λ / 2 phase difference plate 56.
In the process of step S125, S-polarized blue LD and S-polarized yellow fluorescence are output from the polarization conversion element 3e, and the process ends.

As described above, in the present embodiment, as the configuration of the light source device, the excitation light source and the blue light source are separately provided. The polarization of the light beam emitted from at least the blue light source is linearly polarized light perpendicular to the paper surface of FIG. A light beam emitted from the blue light source is incident on the dichroic mirror 1g as S-polarized light and reflected. Furthermore, it is also incident on the polarization separation film 51 of the polarization conversion element 3e as S-polarized light and reflected. That is, S-polarized light having better reflection characteristics and angle characteristics than P-polarized light is used.
Thereby, in consideration of polarization efficiency, it is possible to efficiently obtain a light amount and to obtain an optical device with little light amount loss. In addition, the diffusion plate 2c and the

lenses

2d and 2e, which are dedicated components of the blue optical path 2, are coated in the wavelength region of the blue LD so that the blue LD can be efficiently emitted. . An example of the coating includes an anti-reflection (AR) film.

Further, since the light source for excitation and the light source for blue are separately provided, it is possible to select a wavelength according to each light source. That is, the light source for excitation light selects a high-power and short-wavelength LD to excite the phosphor wheel 1j, and the blue light source is each member (light path, polarizing plate, and liquid crystal) constituting the light source device 40. The long-wavelength LD can be selected according to the life requirement.

Next, a schematic configuration of the projection display device 100 including the light source device 40 according to the first embodiment will be described. FIG. 12 is a schematic configuration diagram illustrating an example of a projection display device including the light source device according to the first embodiment.
The projection display apparatus 100 according to the present embodiment collects light from a light source device 40 that emits light, emits light from a projection lens through a device that displays an image, and projects an image on a display surface such as a screen S. An example of the configuration is shown. A projection display apparatus 100 shown in FIG. 12 is a configuration example of a projector using a 3LCD (Liquid Crystal Display) as a micro display.

The light polarized from the light source device 40 and perpendicular to the incident surface of the condenser lens 30 passes through the condenser lens 30 and is separated for each wavelength range. The light that has passed through the condensing lens 30 is incident on the first reflective dichroic mirror 12a that reflects only light in the red wavelength region and passes light in other wavelength regions. Thereby, the light in the red wavelength region is reflected by the first reflection dichroic mirror 12a and travels toward the reflection mirror 11a. The light in the red wavelength region is further reflected by the reflection mirror 11a and enters the red liquid crystal panel 60a.
The light in the other wavelength region that has passed through the first reflective dichroic mirror 12a is incident on the second reflective dichroic mirror 12b. The second reflective dichroic mirror 12b reflects only light in the green wavelength range, and transmits light in other wavelength ranges, that is, light in the blue wavelength range. The light in the green wavelength region reflected by the second reflective dichroic mirror 12b is incident on the green liquid crystal panel 60b. The light in the blue wavelength band that has passed through the second reflecting dichroic mirror 12b is reflected by the reflecting

mirrors

11b and 11c and then enters the blue liquid crystal panel 60c.

The liquid crystal panels 60a to 60c for the respective colors modulate the incident light according to the input image signal, and generate the signal light of the image corresponding to RGB. For the liquid crystal panels 60a to 60c, for example, a transmissive liquid crystal element using a high temperature polysilicon TFT (Thin Film Transistor) may be used. The signal light modulated by the liquid crystal panels 60a to 60c is incident on the dichroic prism 70 and synthesized. The dichroic prism 70 is formed in a rectangular parallelepiped shape in which four triangular prisms are combined so as to reflect red signal light and blue signal light and transmit green signal light. The signal light of each color synthesized by the dichroic prism 70 enters the projection lens 80 and is projected as an image on a display surface such as the screen S.
In the projection display device 100, the liquid crystal panels 60a to 60c and the dichroic prism 70 function as a light modulation / synthesis system that modulates and combines incident light. The condenser lens 30, the reflective

dichroic mirrors

12a and 12b, and the reflective mirrors 11a to 11c function as an illumination optical system that guides light from the light source device 40 to the liquid crystal panels 60a to 60c constituting the light modulation / synthesis system. is there. The projection lens 80 functions as a projection optical system that projects the image emitted from the dichroic prism 70.

(Second Embodiment)
Next, a schematic configuration of the projector according to the second embodiment of the invention will be described.
FIG. 13 is an example of a block diagram illustrating a schematic configuration of the light source device of the second embodiment.
Referring to FIG. 13, the light source device 40 includes an excitation light source 43, a phosphor 44, a blue light source 45, a dichroic mirror 1g, and a polarization conversion unit 46.

The excitation light source 43 emits excitation light 47. The phosphor 44 emits non-polarized fluorescence 49 when the excitation light 47 is irradiated. The blue light source 45 emits linearly polarized blue light 48. The dichroic mirror 1 g reflects the excitation light 47 emitted from the excitation light source 43 and irradiates it toward the phosphor 44. The dichroic mirror 1 g transmits the non-polarized fluorescence 49 emitted from the phosphor 44 based on the irradiation of the excitation light 47. The dichroic mirror 1g reflects the linearly polarized blue light 48 emitted from the blue light source 45 in the same direction as the direction through which the non-polarized fluorescence 49 is transmitted. The polarization conversion unit 46 converts the polarization of the non-polarized fluorescence 49 transmitted through the dichroic mirror 1g into the same polarization as the linearly polarized blue light 48. The polarization conversion unit 46 does not convert the polarization of the linearly polarized blue light 48 reflected by the dichroic mirror 1g.

Note that the computer program stored in the storage unit (not shown) of the light source device 40 may be provided as a recording medium, or may be provided via a network such as the Internet. The recording medium includes a computer-usable medium or a computer-readable medium and can record or read information using magnetism, light, electronic, electromagnetic, infrared, or the like. Examples of such media include semiconductor memory, semiconductor or solid-state storage devices, magnetic tape, removable computer diskettes, random access memory (RAM (Random Access Memory)), read only memory (ROM (Read Only Memory)). , Magnetic disks, optical disks, magneto-optical disks, and the like.

The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.
[Appendix 1]
An excitation light source that emits excitation light;
A phosphor that emits unpolarized fluorescence when irradiated with the excitation light; and
A blue light source that emits linearly polarized blue light;
Reflecting the excitation light emitted from the excitation light source and irradiating the phosphor toward the phosphor, transmitting the non-polarized fluorescence emitted from the phosphor based on the irradiation of the excitation light, and transmitting the blue light source A dichroic mirror that reflects the linearly polarized blue light emitted from the non-polarized fluorescence in the same direction as the transmitted light;
Polarization conversion means for converting the polarization of the non-polarized fluorescence transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light, and not converting the polarization of the linearly polarized blue light reflected by the dichroic mirror; A light source device provided.
[Appendix 2]
The polarization conversion means includes a transparent member provided with a polarization separation film and a reflection film, and a retardation plate,
The light source device according to appendix 1, wherein the linearly polarized blue light is reflected by the polarization separation film and the reflection film and does not pass through the retardation plate.
[Appendix 3]
The light source device according to appendix 2, wherein the polarized light of the blue light incident on the polarization separation film is S-polarized light.
[Appendix 4]
4. The light source device according to

appendix

2 or 3, wherein the blue light incident on the dichroic mirror is S-polarized light.
[Appendix 5]
The non-polarized fluorescence is separated into P-polarized fluorescence and S-polarized fluorescence in the polarization separation film, and the P-polarized fluorescence is transmitted through the polarization separation film in the retardation plate. 5. The light source device according to any one of appendices 2 to 4, wherein the light source device is converted to S-polarized light.
[Appendix 6]
The dichroic mirror is
A first surface that reflects the excitation light emitted from the excitation light source in a direction perpendicular to the incident direction of the excitation light and irradiates the excitation light toward the phosphor;
A second surface that transmits non-polarized fluorescence emitted from the phosphor and reflects linearly polarized blue light incident from the blue light source in the same direction as the non-polarized fluorescence is transmitted; The light source device according to any one of appendices 1 to 5, provided with:
[Appendix 7]
The light source device according to appendix 6, wherein the excitation light source and the blue light source are provided to face each other via the first surface and the second surface of the dichroic mirror.
[Appendix 8]
The light source device according to any one of appendices 1 to 7, wherein a diffusion member that diffuses the excitation light is provided between the excitation light source and the dichroic mirror.
[Appendix 9]
9. The light source device according to any one of appendices 1 to 8, wherein a diffusing member that diffuses the linearly polarized blue light is provided between the blue light source and the dichroic mirror.
[Appendix 10]
10. The light source device according to any one of appendices 1 to 9, wherein the fluorescence is yellow light.
[Appendix 11]
An excitation light source that emits excitation light;
A phosphor that emits unpolarized fluorescence when irradiated with the excitation light; and
A blue light source that emits linearly polarized blue light;
Reflecting the excitation light emitted from the excitation light source and irradiating the phosphor toward the phosphor, transmitting the non-polarized fluorescence emitted from the phosphor based on the irradiation of the excitation light, and transmitting the blue light source A dichroic mirror that reflects the linearly polarized blue light emitted from the non-polarized fluorescence in the same direction as the transmitted light;
Polarization conversion means for converting the polarization of the non-polarized fluorescence transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light, and not converting the polarization of the linearly polarized blue light reflected by the dichroic mirror; A projection display device including the light source device.
[Appendix 12]
The polarization conversion means includes a transparent member provided with a polarization separation film and a reflection film, and a retardation plate,
The projection display device according to appendix 11, wherein the linearly polarized blue light is reflected by the polarization separation film and the reflection film and does not pass through the retardation plate.
[Appendix 13]
The projection display device according to appendix 12, wherein the polarized light of the blue light incident on the polarization separation film is S-polarized light.
[Appendix 14]
14. The projection display device according to appendix 12 or 13, wherein the polarized light of the blue light incident on the dichroic mirror is S-polarized light.
[Appendix 15]
The non-polarized fluorescence is separated into P-polarized fluorescence and S-polarized fluorescence in the polarization separation film, and the P-polarized fluorescence is transmitted through the polarization separation film in the retardation plate. 15. The projection display device according to any one of appendices 12 to 14, which is converted to S-polarized light.
[Appendix 16]
The dichroic mirror is
A first surface that reflects the excitation light emitted from the excitation light source in a direction perpendicular to the incident direction of the excitation light and irradiates the excitation light toward the phosphor;
A second surface that transmits non-polarized fluorescence emitted from the phosphor and reflects linearly polarized blue light incident from the blue light source in the same direction as the non-polarized fluorescence is transmitted; The projection display device according to any one of appendices 11 to 15, comprising:
[Appendix 17]
The projection display device according to appendix 16, wherein the excitation light source and the blue light source are provided to face each other through the first surface and the second surface of the dichroic mirror.
[Appendix 18]
18. The projection display device according to any one of appendices 11 to 17, wherein a diffusion member that diffuses the excitation light is provided between the excitation light source and the dichroic mirror.
[Appendix 19]
The projection display device according to any one of appendices 11 to 18, wherein a diffusing member for diffusing the linearly polarized blue light is provided between the blue light source and the dichroic mirror.
[Appendix 20]
20. The projection display device according to any one of appendices 11 to 19, wherein the fluorescence is yellow light.
[Appendix 21]
An excitation light source that emits excitation light;
A phosphor that emits unpolarized fluorescence when irradiated with the excitation light; and
A blue light source that emits linearly polarized blue light;
Reflecting the excitation light emitted from the excitation light source and irradiating the phosphor toward the phosphor, transmitting the non-polarized fluorescence emitted from the phosphor based on the irradiation of the excitation light, and transmitting the blue light source A dichroic mirror that reflects the linearly polarized blue light emitted from the dichroic mirror in the same direction as the non-polarized fluorescence is transmitted,
Converting the non-polarized fluorescence polarized light transmitted through the dichroic mirror into the same polarized light as the linearly polarized blue light, and not converting the linearly polarized blue light polarized light reflected by the dichroic mirror. A control method of a projection display device provided.

DESCRIPTION OF SYMBOLS 1 Fluorescence excitation optical system 1a, 2a

Blue LD array

1b, 2b Blue

LD collimator lens

1c, 1d, 1e, 1h, 1i, 2d, 2e, 3a,

3b Lens

1f, 2c Diffusion plate

1g Dichroic mirror

1j Phosphor wheel 2 Blue optical path 3 Fluorescent / blue common

optical path

3c, 3d integrator 3e Polarization conversion element 4 Entrance surface 5 Exit surface 6 Yellow phosphor 7

Motor shaft

11a, 11b, 11c Reflective mirror 12a First reflective dichroic mirror 12b Second reflective dichroic mirror 30 Condensing lens 40 Light source device 41 Light emitting element 42 Collimator lens 43 Excitation light source 44 Phosphor 45 Blue light source 46 Polarization conversion unit 47 Excitation light 48 Linearly polarized blue light 49 Unpolarized fluorescence 51 Polarization separation film 52 Reflection film 53 Transparent member 56 λ / 2

Phase difference plate

60a, 60b, 60c Liquid crystal panel 70 Dichroic prism 80 Projection lens 100 Projection display device 101 Non-polarized light 102 P-polarized light 103 S-polarized light S Screen

Claims

An excitation light source that emits excitation light;
A phosphor that emits unpolarized fluorescence when irradiated with the excitation light; and
A blue light source that emits linearly polarized blue light;
Reflecting the excitation light emitted from the excitation light source and irradiating the phosphor toward the phosphor, transmitting the non-polarized fluorescence emitted from the phosphor based on the irradiation of the excitation light, and transmitting the blue light source A dichroic mirror that reflects the linearly polarized blue light emitted from the non-polarized fluorescence in the same direction as the transmitted light;
Polarization conversion means for converting the polarization of the non-polarized fluorescence transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light, and not converting the polarization of the linearly polarized blue light reflected by the dichroic mirror; A light source device provided.
The polarization conversion means includes a transparent member provided with a polarization separation film and a reflection film, and a retardation plate,
The light source device according to claim 1, wherein the linearly polarized blue light is reflected by the polarization separation film and the reflection film and does not pass through the retardation plate.
The light source device according to claim 2, wherein the polarized light of the blue light incident on the polarization separation film is S-polarized light.
The light source device according to claim 2 or 3, wherein the polarized light of the blue light incident on the dichroic mirror is S-polarized light.
The non-polarized fluorescence is separated into P-polarized fluorescence and S-polarized fluorescence in the polarization separation film, and the P-polarized fluorescence is transmitted through the polarization separation film in the retardation plate. The light source device according to claim 2, wherein the light source device is converted into S-polarized light.
The dichroic mirror is
A first surface that reflects the excitation light emitted from the excitation light source in a direction perpendicular to the incident direction of the excitation light and irradiates the excitation light toward the phosphor;
A second surface that transmits non-polarized fluorescence emitted from the phosphor and reflects linearly polarized blue light incident from the blue light source in the same direction as the non-polarized fluorescence is transmitted; The light source device according to claim 1, further comprising:
The light source device according to claim 6, wherein the excitation light source and the blue light source are provided to face each other through the first surface and the second surface of the dichroic mirror.
The light source device according to any one of claims 1 to 7, wherein a diffusion member that diffuses the excitation light is provided between the excitation light source and the dichroic mirror.
The light source device according to any one of claims 1 to 8, wherein a diffusing member for diffusing the linearly polarized blue light is provided between the blue light source and the dichroic mirror.
The light source device according to any one of claims 1 to 9, wherein the fluorescence is yellow light.
A projection display device comprising the light source device according to any one of claims 1 to 10.
An excitation light source that emits excitation light;
A phosphor that emits unpolarized fluorescence when irradiated with the excitation light; and
A blue light source that emits linearly polarized blue light;
Reflecting the excitation light emitted from the excitation light source and irradiating the phosphor toward the phosphor, transmitting the non-polarized fluorescence emitted from the phosphor based on the irradiation of the excitation light, and transmitting the blue light source A dichroic mirror that reflects the linearly polarized blue light emitted from the dichroic mirror in the same direction as the non-polarized fluorescence is transmitted,
Converting the non-polarized fluorescence polarized light transmitted through the dichroic mirror into the same polarized light as the linearly polarized blue light, and not converting the linearly polarized blue light polarized light reflected by the dichroic mirror. A method for controlling a light source device.