CN212031908U - Light source device and projection display device - Google Patents
Light source device and projection display device Download PDFInfo
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- CN212031908U CN212031908U CN201790001562.5U CN201790001562U CN212031908U CN 212031908 U CN212031908 U CN 212031908U CN 201790001562 U CN201790001562 U CN 201790001562U CN 212031908 U CN212031908 U CN 212031908U
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Abstract
The invention provides a light source device capable of efficiently obtaining light amount in consideration of polarization efficiency. The disclosed device is provided with: an excitation light source (43) that irradiates excitation light; a fluorescent material (44) that emits unpolarized fluorescence when irradiated with excitation light; a blue light source (45) for irradiating linearly polarized blue light; a dichroic mirror (1g) that reflects excitation light emitted from the excitation light source and irradiates the excitation light toward the phosphor, transmits unpolarized fluorescence emitted from the phosphor upon irradiation of the excitation light, and reflects linearly polarized blue light emitted from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted; and a polarization conversion unit (46) that converts the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light, without converting the polarization of the linearly polarized blue light reflected by the dichroic mirror.
Description
Technical Field
The present invention relates to a light source device, a control method and a program for a light source device, and a projection display device, and more particularly, to a light source device including a plurality of light sources that emit light of different colors, a control method and a program for a light source device, and a projection display device.
Background
As a projection system of a projection display device (hereinafter, also referred to as a projector) that projects an image onto a screen, a liquid crystal system and a DLP (registered trademark) system are known. As Light sources of projectors having these systems, technologies using lasers have been focused in addition to LEDs (Light Emitting diodes) and lamps. In particular, a laser has a longer life and higher reliability than a lamp, and therefore has attracted attention as a light source instead of a lamp.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open No. 2014-186115
Disclosure of Invention
Problems to be solved by the invention
In recent projectors, it has been proposed to use a plurality of light sources LD (Laser Diode) in a light source section, thereby using the light sources LD for excitation light of a yellow phosphor and blue light. When the projection system of the projector is a liquid crystal system, 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 obtain the light amount efficiently in consideration of the polarization efficiency.
In patent document 1, light provided in the blue wavelength region is efficiently reflected by the 1 st dichroic mirror by a function of rotating polarization or disturbing polarization when reflected on the surface of the wheel. However, no consideration is given to the polarization of light emitted from the 1 st light source or the 2 nd light source. Therefore, when the polarization is made uniform by using the polarization conversion element after the light is generated by being emitted from the light source unit, there is a problem that the light amount cannot be efficiently obtained.
An object of the present invention is to provide a light source device, a control method and program for the light source device, and a projection display device that can solve the problem of efficiently obtaining the amount of light in consideration of polarization efficiency.
Means for solving the problems
The light source device of the present invention includes: an excitation light source that irradiates excitation light; a phosphor that emits unpolarized fluorescence when the excitation light is irradiated; a blue light source that irradiates linearly polarized blue light; a dichroic mirror that reflects the excitation light irradiated from the excitation light source to irradiate the fluorescent material, transmits the unpolarized fluorescence emitted from the fluorescent material upon irradiation of the excitation light, and reflects the linearly polarized blue light irradiated from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted; and a polarization conversion unit that converts the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light without converting the polarization of the linearly polarized blue light reflected by the dichroic mirror.
The projection display device of the present invention includes the light source device.
Further, a control method of a light source device according to the present invention includes: an excitation light source that irradiates excitation light; a phosphor that emits unpolarized fluorescence when the excitation light is irradiated; a blue light source that irradiates linearly polarized blue light; and a dichroic mirror that reflects the excitation light irradiated from the excitation light source to irradiate the fluorescent material, transmits the unpolarized fluorescence emitted from the fluorescent material upon irradiation of the excitation light, and reflects the linearly polarized blue light irradiated from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted, wherein the control method of the light source device includes: converting the polarization of the unpolarized fluorescent light 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.
Effects of the invention
According to the present invention, the light amount can be efficiently obtained in consideration of the polarization efficiency.
Drawings
Fig. 1 is a schematic diagram showing an example of the structure of a light source device according to embodiment 1 of the present invention.
Fig. 2A is a schematic view showing a light source image irradiated in a state where a diffusion plate is not provided in the fluorescence excitation optical system according to embodiment 1.
Fig. 2B is a schematic diagram showing a light source image irradiated in a state where a diffusion plate is present in the fluorescence excitation optical system according to embodiment 1.
Fig. 3 is a schematic view showing an example of a fluorescent wheel used in the light source device shown in fig. 1.
Fig. 4 is a characteristic diagram showing the spectral reflection characteristics of P polarization of the dichroic mirror.
Fig. 5 is a characteristic diagram showing spectral reflection characteristics of the S polarization of the dichroic mirror.
Fig. 6 is a characteristic diagram showing spectral transmission characteristics of a dichroic mirror.
Fig. 7 is a schematic block diagram showing the structure of the polarization conversion element of the light source device.
Fig. 8 is a schematic cross-sectional view for explaining the operation of the polarization conversion element.
Fig. 9 is a characteristic diagram showing spectral transmission characteristics of the polarization conversion element for S-polarized input light.
Fig. 10 is a characteristic diagram showing spectral transmission characteristics of the polarization conversion element for P-polarized input light.
Fig. 11 is a flowchart showing the operation of the light source device according to embodiment 1.
Fig. 12 is a schematic configuration diagram showing an example of a projection type display device including the light source device of embodiment 1.
Fig. 13 is a schematic diagram showing the structure of a light source device according to embodiment 2 of the present invention.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings. In the drawings described below, unidirectional arrows clearly indicate a certain signal (data) flow, and bidirectional arrows are not excluded.
(embodiment 1)
First, a schematic configuration of a light source device according to embodiment 1 of the present invention will be described.
Fig. 1 is a schematic diagram showing a structure of a light source device according to embodiment 1.
As shown in fig. 1, the light source device 40 of 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 fluorescence wheel 1 j.
The blue light path 2 includes a blue LD array 2a, a blue LD collimator lens 2b, a diffuser plate 2c, and lenses 2d and 2 e.
The fluorescence/blue common light path 3 has lenses 3a, 3b, integrators 3c, 3d, and a polarization conversion element 3 e.
The following describes elements constituting the fluorescence excitation optical system 1, the blue light path 2, and the fluorescence/blue common light path 3 of the light source device 40 according to the present embodiment.
Excitation light sources are arranged in an array on the blue LD array 1a of the fluorescence excitation optical system 1. The blue LD collimator lens 1b performs aberration correction so that light rays irradiated from the blue LD array 1a as a light source become parallel light at a focal point. The lenses 1c, 1d, and 1e converge the excitation light aberration-corrected to parallel light by the blue LD collimator lens 1 b. The diffusion plate 1f diffuses the excitation light condensed by the lenses 1c, 1d, and 1 e. The dichroic mirror 1g reflects the excitation light diffused by the diffusion plate 1f toward the fluorescent wheel 1 j. The lenses 1h and 1i converge the excitation light reflected by the dichroic mirror 1g on the fluorescent wheel 1 j. Further, the lenses 1h and 1i cause the yellow fluorescent light emitted from the fluorescent wheel 1j to enter the dichroic mirror 1 g. The fluorescent wheel 1j is a disk-shaped wheel having an annular yellow fluorescent region that emits yellow fluorescent light when excited by excitation light. The structure of the luminescent wheel 1j will be described later.
The blue LD array 2a of the blue light path 2 is provided with blue light sources in an array. The blue LD collimator lens 2b performs aberration correction so that the light beam irradiated from the blue LD array 2a as a light source becomes parallel light at the focal point. The diffuser plate 2c diffuses the blue LD light aberration-corrected by the blue LD collimating lens 2 b. The lenses 2d and 2e condense the blue LD light diffused by the diffuser plate 2 c. The dichroic mirror 1g reflects the blue LD light converged by the lenses 2d, 2e toward the fluorescent/blue common light path 3.
The dichroic mirror 1g of the fluorescence/blue common light path 3 combines the yellow fluorescence emitted from the fluorescence wheel 1j and the blue LD light reflected in the direction of the fluorescence/blue common light path 3. The lenses 3a and 3b condense the combined yellow fluorescent light and blue LD light. The integrators 3c and 3d homogenize the light intensity of the combined yellow fluorescent light and blue LD light beam condensed by the lenses 3a and 3 b. The polarization conversion element 3e makes the polarization of the combined light of the yellow fluorescent light and the blue LD light, which is obtained by uniformizing the light intensity of the light beams by the integrators 3c and 3d, uniform in a constant polarization direction. The polarization conversion element 3e will be described later.
Next, the operation of the optical system of the light source device of the present embodiment will be specifically described. In the fluorescence excitation optical system 1, the polarization of light 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. 1. The reason why the polarization of the light emitted from blue LD array 1a is linear polarization perpendicular to the paper surface of fig. 1 will be described later. In the case of the fluorescent wheel 1j that converges the light emitted from the blue LD array 1a on the optical path of the fluorescence excitation optical system 1, it is necessary to suppress the temperature rise of the fluorescent wheel 1j caused by the irradiation of the excitation light. Therefore, by using the diffusion plate 1f, the intensity distribution of the excitation light irradiated to the luminescent wheel 1j is made uniform. This point will be described with reference to fig. 2. Fig. 2A is a schematic view showing a light source image irradiated in a state where a diffusion plate is not provided on the luminescent wheel, and fig. 2B is a schematic view showing a light source image irradiated in a state where a diffusion plate is provided on the luminescent wheel.
By avoiding the state of the light source shown in fig. 2A that is irradiated in a concentrated manner, and by interposing the diffuser plate 1f, the light source image is formed into a convergent shape having a certain width as shown in fig. 2B. In order to obtain the same effect as the diffusion plate 1f, the optical element that produces a laser beam having a uniform light intensity distribution, such as a homogenizer, a light tunnel, or a rod integrator, may be used instead.
The laser light emitted from the blue LD array 1a passes through the blue LD collimator lens 1b, and becomes parallel light. The excitation light flattened by passing through the collimator lens 1b is condensed by using the lens groups 1c, 1d, 1 e. The excitation light condensed by the lens groups 1c, 1d, and 1e is diffused by using the diffusion plate 1 f. Then, the diffused excitation light is reflected in the direction of the fluorescent wheel 1j by using the dichroic mirror 1 g. The dichroic mirror 1g has a property of reflecting blue light and transmitting yellow light.
In the present embodiment, the adjustment mechanism is provided in the lens 1e in order to absorb an attachment error of the lens and the like disposed between the blue LD array 1a and the luminescent wheel 1 j. In addition, in the case where there is no problem in the mechanism restriction, it is preferable to provide an adjustment mechanism also in the optical axis direction of the luminescent wheel 1 j. The light emission position of the yellow fluorescent light emitted from the fluorescent wheel 1j can be adjusted by the adjustment mechanism using the lens 1 e. Further, by using the adjustment mechanism provided in the optical axis direction of the luminescent wheel 1j, the light amount of the yellow luminescent light emitted from the luminescent wheel 1j can also be adjusted. Thus, a stable and efficient light source device can be obtained.
The laser light emitted from the blue LD array 1a passes through a collimator lens for a fluorescent wheel, not shown, and is converged on the fluorescent wheel 1 j. Here, the fluorescence wheel 1j will be described with reference to fig. 3. Fig. 3 is a schematic view showing an example of a fluorescent wheel used in the light source device shown in fig. 1.
The luminescent wheel 1j has a hollow disk-like shape when viewed from a direction perpendicular to the rotation surface. Further, a region of the yellow phosphor 6 is formed annularly. The center of motor shaft 7 of luminescent wheel 1j is attached to a rotating shaft of a motor not shown. The luminescent wheel 1j rotates about the center of a motor shaft 7 to which a rotation shaft of a motor, not shown, is attached. By rotating the fluorescent wheel 1j, the temperature rise caused by the irradiation of the excitation light to the region of the yellow fluorescent material 6 can be alleviated. When the luminescent wheel 1j has a sufficient cooling function, the luminescent wheel 1j may not be rotated.
When the excitation light enters the fluorescent wheel 1j and enters the region of the yellow fluorescent material 6, yellow fluorescent light is emitted from the fluorescent wheel 1 j. The yellow fluorescent light passes through the lenses 1i, 1h and is incident on the dichroic mirror 1 g. The yellow fluorescent light emitted from the fluorescent wheel 1j is lambertian diffused light having an ideal diffuse reflection property. Lambertian diffuse light is natural light with no polarization characteristics. Here, the polarization characteristics are used, in which the reflection characteristics and the angle dependence are better than the S polarization, which is the polarization perpendicular to the incident surface to the optical element or the like, and the P polarization, which is the polarization parallel to the incident surface to the optical element or the like. This point will be described with reference to fig. 4 and 5. Fig. 4 shows the spectral reflection characteristic of the P-polarization of the dichroic mirror, and fig. 5 shows the spectral reflection characteristic of the S-polarization of the dichroic mirror.
Comparing fig. 4 and 5, it is understood that the reflectance is closer to 100% in the S-polarization than in the P-polarization in the blue wavelength region, i.e., in the range of 420nm to 500 nm.
Further, the transmittance of the dichroic mirror 1g in the wavelength range of 570nm to 590nm, which is the wavelength of the yellow fluorescence, is about 100% as shown in fig. 6. Fig. 6 shows spectral transmission characteristics of a dichroic mirror.
Therefore, the yellow fluorescent light passes through the dichroic mirror 1g and is condensed by the lenses 3a and 3 b. Then, the yellow fluorescence homogenizes the light intensity of the light beam in the integrators 3c and 3d, and enters the polarization conversion element 3 e.
On the other hand, in the blue light path 2, the polarization of the light beam emitted from the blue LD array 2a in which blue LDs are arranged in an array form is also linear polarization perpendicular to the paper surface of fig. 1, as described above with reference to fig. 4 and 5, utilizing such polarization characteristics that the reflection characteristics and the angle dependence of S-polarization are better than those of P-polarization. In addition, with respect to the light beam emitted from blue LD array 2a, (1) is incident and reflected as S polarization with respect to dichroic mirror 1 g. Further, with respect to the light beam emitted from the blue LD array 2a, (2) the light beam is also incident and reflected as S-polarized light with respect to a polarization separation film 51 of the polarization conversion element 3e, which will be described later.
The diffusion plate 2c and the lenses 2d and 2e, which are components dedicated to the blue light path 2, are coated with a coating exclusively for S polarization in the wavelength region (frequency band) of the blue LD to be used, whereby the blue LD can be efficiently emitted. As an example of the coating layer, an Antireflection (AR) film and the like can be cited.
In the blue light path 2, when the light beam of the blue LD is directly emitted, coherent light (light having the same phase) is directly emitted to the outside. This may affect the eyes of the person, and thus has a problem in terms of safety. Further, if a bright and dark speckle pattern (speckle) is generated in the blue LD due to scattering of a random medium, and the speckle becomes large, there is a high possibility that the image quality of the projector is affected.
In order to solve these problems, a diffuser plate 2c is disposed on the blue light path 2, and the speckle is improved while securing safety by spatially alleviating coherence. Further, disposing the diffuser plate on the fluorescence/blue common light path 3 decreases the amount of yellow fluorescence emitted from the fluorescence wheel 1 j. Therefore, the diffusion plate 2c is preferably disposed between the blue LD array 2a and the dichroic mirror 1 g. Further, depending on the image quality required by the projector, the diffusion plate 2c may be disposed in plural numbers, or the diffusion plate 2c may be physically moved by being vibrated or rotated to alleviate the coherence. In the present embodiment, the adjustment mechanism is provided in the blue LD collimating lens 2d in order to absorb an attachment error of a member disposed between the blue LD array 2a and the lens 3 b.
By providing the adjustment mechanism on the optical paths of the fluorescence excitation optical system 1 and the blue optical path 2 in this manner, it is possible to efficiently transmit light and alleviate luminance unevenness caused by the optical path difference between the fluorescence excitation optical system 1 and the blue optical path 2.
Next, the polarization conversion element will be described with reference to fig. 7 and 8.
First, the structure of the polarization conversion element of the light source device will be described with reference to fig. 7. Fig. 7 is a schematic block diagram showing the structure of the polarization conversion element of the light source device. The light source device 40 shown in fig. 7 has a light emitting element 41, a collimator lens 42, and a polarization conversion element 3 e. 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 unpolarized light (101). The collimator lens 42 collimates the light from the light emitting element 41 as much as possible. Unpolarized light (101) from the collimator lens 42 enters the transparent member 53, and is separated into P-polarized light (102) that propagates in a straight line and S-polarized light (103) that is reflected in the orthogonal direction by the polarized light separating film 51. The S-polarized light (103) is bent in the optical path by the reflection 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 ° in the polarization direction by the λ/2 phase difference plate 56, and becomes S-polarized light (103) having the same polarization direction as the S-polarized light (103) emitted from the reflection film 52 of the transparent member 53. That is, the unpolarized light (101) emitted from the light emitting element 41 is made to coincide with the S-polarized linearly polarized light (103) by using the polarization conversion element 3 e. By arranging a plurality 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 3e includes a plurality of polarization separation films 51, a plurality of reflection films 52, a flat plate-shaped transparent member 53 formed in a rectangular shape and provided with the polarization separation films 51 and the reflection films 52, and a plurality of λ/2 phase difference plates 56 provided with λ/2 phase difference films.
The polarization separation film 51 and the reflection film 52 are 1 set, and the polarization separation film 51 is disposed obliquely to the incident light, and separates the incident light beam into 2 linearly polarized light beams. The reflection film 52 is disposed in parallel with the light-reflecting side of the polarization separation film 51, and reflects one of the polarized light beams separated and reflected by the polarization separation film 51.
The λ/2 phase difference film of the λ/2 phase difference plate 56 is provided on the light beam exit side of the transparent member 53, and converts the polarization axis of one polarized light beam to coincide with the polarization axis of the other polarized light beam.
In the polarization conversion element 3e, the respective polarized light separation films 51 and the reflection films 52 are arranged so that the polarized light separation films 51 and the reflection films 52 are in symmetrical positions with each other on both sides of the center line of the polarization conversion element 3 e.
In fig. 8, a light flux of unpolarized light from the 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 polarized light separating film 51 transmits the P-polarized linearly polarized light beam and reflects the S-polarized linearly polarized light beam. The S-polarization reflected by the polarization separation film 51 is reflected by the reflection film 52 to bend the optical path, and the traveling direction becomes parallel to the P-polarization. The P-polarized linearly polarized light beam transmitted through the polarization separation film 51 passes through the λ/2 phase difference plate 56, and is converted into S-polarization. That is, the unpolarized light incident from the incident surface 4 is matched with the S-polarized linearly polarized light by the polarization conversion element 3 e.
Returning to fig. 1, the blue LD reflected by the dichroic mirror 1g is synthesized with the yellow fluorescent light emitted from the fluorescent wheel 1j and transmitted through the dichroic mirror 1 g. Hereinafter, the light obtained by the synthesis is also referred to as a synthesized light.
The polarization of the light of the blue LD irradiated from blue LD array 2a as the light source is linear polarization perpendicular to the paper surface of fig. 1. The light beam of blue LD enters dichroic mirror 1g as S-polarized light, and is reflected by dichroic mirror 1g as S-polarized light. Then, the blue LD reflected by the dichroic mirror 1g enters the lens 3a, the lens 3b, and the integrators 3c, 3d in the direction of the fluorescence/blue common light path 3 in the state of S polarization.
The blue LD is condensed by the lenses 3a and 3b, and then, the light intensity of the light beam is uniformized by the integrators 3c and 3d, and enters the polarization conversion element 3 e. Then, the blue LD is incident and reflected as S-polarization with respect to the polarized light separation film 51 constituting the polarization conversion element 3 e. Further, the blue LD is further reflected by the reflection film 52 constituting the polarization conversion element 3e after being reflected by the polarized light separation film 51 constituting the polarization conversion element 3 e. At this time, the polarization of the blue LD is not switched, and the state of S polarization is maintained.
On the other hand, the yellow fluorescence is incident on the polarization separation film 51 constituting the polarization conversion element 3e as polarized light having S-polarized components and P-polarized components. The S-polarized component in the yellow fluorescence maintains the S-polarized state without converting the polarization, as in the blue LD. The P-polarized component of the yellow fluorescence passes through the polarization separation film 51, and is converted in polarization by the λ/2 phase difference plate 56 constituting the polarization conversion element 3 e. That is, the polarization of the P-polarized component in the yellow fluorescence is converted into the S-polarization.
As a result, the polarization of the blue LD and the yellow fluorescent light emitted from the polarization conversion element 3e become the same linear polarization (S polarization) over the entire spectrum.
In this way, the polarization of blue LD incident on polarization separation film 51 of polarization conversion element 3e is preferably at least S polarization. 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 blue LD is absorbed by the polarization separation film 51 when the blue LD passes through the polarization separation film 51, and thus a loss of light amount occurs. Further, when the light passes through the λ/2 phase difference plate 56, a loss of light amount occurs. Therefore, when the polarization of the blue LD is S-polarized, a light source device with low loss and high transmission efficiency by the polarization conversion element 3e can be realized.
Since the angle dependence is more advantageous also for S-polarization, the light beam of the blue LD is arranged so as to be incident and reflected as S-polarization also with respect to the polarization separation film 51 of the polarization conversion element 3e, and a light source device with higher transmission efficiency can be obtained. Since the diffusion plate 2c is provided on the blue light path 2, the incident angle is in the range of about several degrees to about ten and several degrees. Here, spectral transmission characteristics in S-polarization and P-polarization of the polarization conversion element are described with reference to fig. 9 and 10. Fig. 9 is a spectral transmission characteristic of the polarization conversion element for S-polarized input light. Fig. 10 is a spectral transmission characteristic of the polarization conversion element for P-polarized input light.
As shown in fig. 9 and 10, it is found that S-polarization has a transmittance of more than 90% in a wavelength region (range of 420nm to 500 nm) of blue LD and a wavelength region (range of 570nm to 590 nm) of yellow fluorescence, as compared with P-polarization. Therefore, if light enters the polarization separation film 51 of the polarization conversion element 3e as P-polarization, the light is affected by the angle dependence of the polarization conversion element 3 e. Therefore, when the polarization separation film 51 of the polarization conversion element 3e is incident as S-polarization, a light source device with higher transmission efficiency can be obtained.
Next, the operation of the light source device according to embodiment 1 will be described. Fig. 11 is a flowchart showing the operation of the light source device according to embodiment 1.
In the process of step S121, the blue LD array 1a of the fluorescence excitation optical system 1 is irradiated with excitation light. The blue LD array 2a of the blue light path 2 irradiates the incident surface of the dichroic mirror 1g with blue LD which is linearly polarized perpendicular to the paper surface of fig. 1.
In the process of step S122, the dichroic mirror 1g reflects the excitation light toward the fluorescent wheel 1 j. The dichroic mirror 1g transmits the yellow fluorescent light emitted from the fluorescent wheel 1 j. The dichroic mirror 1g reflects the blue LD incident as S-polarized 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 converged by the lenses 3a and 3b, and the light intensities of the light beams are uniformized by the integrators 3c and 3 d.
In the process of step S124, the polarization conversion element 3e reflects the blue LD that is incident as S-polarized with respect to the incident surface of the polarization separation film 51 constituting the polarization conversion element 3e, through the polarization separation film 51, and through the reflection film 52. The polarization conversion element 3e reflects the S-polarized component of the yellow fluorescent light by the polarized light separation film 51 and by the reflection film 52. The P-polarized component of the yellow fluorescence is transmitted through the polarization conversion film 51 and converted into S-polarization by the λ/2 phase difference plate 56.
In the process of step S125, the S-polarized blue LD and the S-polarized yellow fluorescence are output from the polarization conversion element 3e, and the process is ended.
As described above, in the present embodiment, the excitation light source and the blue light source are provided as the light source device. Then, at least the polarization of the light emitted from the blue light source is linearly polarized perpendicular to the paper surface of fig. 1. Further, the light emitted from the light source for blue is incident on the dichroic mirror 1g as S-polarized light and is reflected. Further, the polarization separation film 51 of the polarization conversion element 3e is also incident and reflected as S-polarization. That is, S-polarization, which has better reflection characteristics and angular characteristics than P-polarization, is used.
Thus, the light quantity can be efficiently obtained in consideration of the polarization efficiency, and an optical device with less light quantity loss can be obtained. Further, a coating layer dedicated to S polarization is applied to the diffusion plate 2c and the lenses 2d and 2e, which are dedicated parts of the blue light path 2, in the wavelength region of the blue LD, thereby enabling efficient emission of the blue LD. As an example of the coating layer, an Antireflection (AR) film and the like can be cited.
Further, since the excitation light source and the blue light source are provided separately, it is possible to select wavelengths corresponding to the respective light sources. That is, the excitation light source selects a high-output and short-wavelength LD for exciting the fluorescent wheel 1j, and the blue light source can also select a long-wavelength LD in accordance with the lifetime requirements of the respective members (optical path, polarizing plate, and liquid crystal) constituting the light source device 40.
Next, a schematic configuration of a projection display device 100 including the light source device 40 according to embodiment 1 will be described. Fig. 12 is a schematic configuration diagram showing an example of a projection type display device including the light source device of embodiment 1.
The projection display apparatus 100 according to the present embodiment is an example of a configuration of a projector that collects light from the light source apparatus 40 emitting light, emits light from a projection lens through a device for displaying an image, and projects the image on a display surface such as a screen S. The projection Display apparatus 100 shown in fig. 12 is one configuration example of a projector using a 3LCD (Liquid Crystal Display) as a microdisplay.
The light emitted from the light source device 40 and polarized perpendicular to the incident surface of the condenser lens 30 passes through the condenser lens 30 and is separated for each wavelength region. The light having passed through the condenser lens 30 enters the 1 st reflecting dichroic mirror 12a that reflects only light in the red wavelength region and passes light in the other wavelength region. Thereby, light in the wavelength region of red is reflected by the 1 st reflective dichroic mirror 12a and advances toward the reflecting mirror 11 a. The light in the wavelength region of red is further reflected by the mirror 11a and enters the liquid crystal panel 60a for red.
The light having passed through the other wavelength region of the 1 st reflecting dichroic mirror 12a enters the 2 nd reflecting dichroic mirror 12 b. The 2 nd reflecting dichroic mirror 12b reflects only light in the wavelength region of green, and passes light in the other wavelength region, that is, light in the wavelength region of blue. The light in the wavelength region of green reflected by the 2 nd reflecting dichroic mirror 12b enters the liquid crystal panel 60b for green. The light in the wavelength region of blue that has passed through the 2 nd reflecting dichroic mirror 12b is reflected by the reflecting mirrors 11b and 11c, and then enters the liquid crystal panel 60c for blue.
The liquid crystal panels 60a to 60c for the respective colors modulate incident light in accordance with an input image signal, and generate signal light of an image corresponding to RGB. As the liquid crystal panels 60a to 60c, for example, a transmission type liquid crystal element using a high temperature polysilicon TFT (Thin Film Transistor) may be used. The signal lights modulated by the respective liquid crystal panels 60a to 60c are incident on the dichroic prism 70 and combined. The dichroic prism 70 is formed in a rectangular parallelepiped shape by combining 4 triangular prisms so as to reflect the red signal light and the blue signal light and transmit the green signal light. The signal light of each color synthesized by the dichroic prism 70 is incident on the projection lens 80 and is projected as an image on a display surface such as a 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 and synthesis system that modulates and synthesizes incident light. The condenser lens 30, the reflective dichroic mirrors 12a and 12b, and the reflection mirrors 11a to 11c function as an illumination optical system for guiding the light from the light source device 40 to the liquid crystal panels 60a to 60c constituting the light modulation and synthesis system. Then, the projection lens 80 functions as a projection optical system that projects the image emitted from the dichroic prism 70.
(embodiment 2)
Next, a schematic configuration of a projector according to embodiment 2 of the present invention will be described.
Fig. 13 is an example of a block diagram showing a schematic configuration of the light source device according to embodiment 2.
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 section 46.
The excitation light source 43 irradiates the excitation light 47. When the excitation light 47 is irradiated to the fluorescent material 44, unpolarized fluorescence 49 is emitted. The blue light source 45 illuminates linearly polarized blue light 48. The dichroic mirror 1g reflects the excitation light 47 emitted from the excitation light source 43 and emits the reflected light toward the fluorescent material 44. The dichroic mirror 1g transmits unpolarized fluorescent light 49 emitted from the fluorescent material 44 upon irradiation with the excitation light 47. The dichroic mirror 1g reflects the linearly polarized blue light 48 irradiated from the blue light source 45 in the same direction as the direction in which the unpolarized fluorescent light 49 is transmitted. The polarization conversion unit 46 converts the polarization of the unpolarized fluorescent light 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 1 g.
The computer program stored in the storage unit, not shown, of the light source device 40 may be provided from a recording medium or may be provided via a network such as the internet. The recording medium is a computer-usable or computer-readable medium, and includes a medium capable of recording or reading information using magnetism, light, electronics, electromagnetism, infrared rays, or the like. Examples of such media include semiconductor memories, semiconductor or solid state memory devices, magnetic tapes, removable computer disks, random Access memories (rams), read Only memories (roms), magnetic disks, optical disks, and magneto-optical disks.
The present invention has been described above with reference to the embodiments, but the present invention is not limited to the above embodiments. The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
Some or all of the above embodiments may be described as in the following notes, but are not limited to the following.
[ additional notes 1]
A light source device is provided with:
an excitation light source that irradiates excitation light;
a phosphor that emits unpolarized fluorescence when the excitation light is irradiated;
a blue light source that irradiates linearly polarized blue light;
a dichroic mirror that reflects the excitation light irradiated from the excitation light source to irradiate the fluorescent material, transmits the unpolarized fluorescence emitted from the fluorescent material upon irradiation of the excitation light, and reflects the linearly polarized blue light irradiated from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted; and
a polarization conversion unit that converts the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light without converting the polarization of the linearly polarized blue light reflected by the dichroic mirror.
[ appendix 2]
The light source device according to supplementary note 1, wherein,
the polarization conversion unit includes a transparent member and a phase difference plate, the transparent member includes a polarization separation film and a reflection film,
the linearly polarized blue light is reflected at the polarized light separating film and the reflecting film without transmitting through the phase difference plate.
[ additional notes 3]
The light source device according to supplementary note 2, wherein,
the polarization of the blue light incident to the polarized light separating film is S polarization.
[ additional notes 4]
The light source device according to supplementary note 2 or 3, wherein,
the polarization of the blue light incident to the dichroic mirror is S-polarization.
[ additional notes 5]
The light source device according to any one of supplementary notes 2 to 4, wherein,
the unpolarized fluorescence is separated at the polarized light separation film into fluorescence whose polarization characteristic is P-polarization and fluorescence whose polarization characteristic is S-polarization, and the P-polarized fluorescence is transmitted through the polarized light separation film to be converted into S-polarization at the phase difference plate.
[ additional notes 6]
The light source device according to any one of supplementary notes 1 to 5, wherein,
the dichroic mirror includes:
a first surface that reflects excitation light emitted from the excitation light source in a direction orthogonal to an incident direction of the excitation light and emits the excitation light to the fluorescent material; and
and a second surface that transmits unpolarized fluorescence emitted from the phosphor and reflects linearly polarized blue light incident from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted.
[ additional notes 7]
The light source device according to supplementary note 6, wherein,
the excitation light source and the blue light source are provided so as to face each other with the first surface and the second surface of the dichroic mirror interposed therebetween.
[ additional notes 8]
The light source device according to any one of supplementary notes 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]
The light source device according to any one of supplementary notes 1 to 8, wherein,
a diffusion member that diffuses the linearly polarized blue light is provided between the blue light source and the dichroic mirror.
[ appendix 10]
The light source device according to any one of supplementary notes 1 to 9, wherein,
the fluorescence is yellow light.
[ appendix 11]
A projection display device includes a light source device having:
an excitation light source that irradiates excitation light;
a phosphor that emits unpolarized fluorescence when the excitation light is irradiated;
a blue light source that irradiates linearly polarized blue light;
a dichroic mirror that reflects the excitation light irradiated from the excitation light source to irradiate the fluorescent material, transmits the unpolarized fluorescence emitted from the fluorescent material upon irradiation of the excitation light, and reflects the linearly polarized blue light irradiated from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted; and
a polarization conversion unit that converts the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light without converting the polarization of the linearly polarized blue light reflected by the dichroic mirror.
[ appendix 12]
A projection type display apparatus according to supplementary note 11, wherein,
the polarization conversion unit includes a transparent member and a phase difference plate, the transparent member includes a polarization separation film and a reflection film,
the linearly polarized blue light is reflected at the polarized light separating film and the reflecting film without transmitting through the phase difference plate.
[ additional notes 13]
The projection type display apparatus according to supplementary note 12, wherein,
the polarization of the blue light incident to the polarized light separating film is S polarization.
[ appendix 14]
The projection type display apparatus according to supplementary note 12 or 13, wherein,
the polarization of the blue light incident to the dichroic mirror is S-polarization.
[ appendix 15]
The projection type display apparatus according to any one of supplementary notes 12 to 14, wherein,
the unpolarized fluorescence is separated at the polarized light separation film into fluorescence whose polarization characteristic is P-polarization and fluorescence whose polarization characteristic is S-polarization, and the P-polarized fluorescence is transmitted through the polarized light separation film to be converted into S-polarization at the phase difference plate.
[ additional notes 16]
The projection type display apparatus according to any one of supplementary notes 11 to 15, wherein,
the dichroic mirror includes:
a first surface that reflects excitation light emitted from the excitation light source in a direction orthogonal to an incident direction of the excitation light and emits the excitation light to the fluorescent material; and
and a second surface that transmits unpolarized fluorescence emitted from the phosphor and reflects linearly polarized blue light incident from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted.
[ additional character 17]
The projection type display apparatus according to supplementary note 16, wherein,
the excitation light source and the blue light source are provided so as to face each other with the first surface and the second surface of the dichroic mirror interposed therebetween.
[ additional notes 18]
The projection type display apparatus according to any one of supplementary notes 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 type display apparatus according to any one of supplementary notes 11 to 18, wherein,
a diffusion member that diffuses the linearly polarized blue light is provided between the blue light source and the dichroic mirror.
[ appendix 20]
The projection type display apparatus according to any one of supplementary notes 11 to 19, wherein,
the fluorescence is yellow light.
[ appendix 21]
A method for controlling a projection display device is a method for controlling a light source device, the light source device including:
an excitation light source that irradiates excitation light;
a phosphor that emits unpolarized fluorescence when the excitation light is irradiated;
a blue light source that irradiates linearly polarized blue light; and
a dichroic mirror that reflects the excitation light irradiated from the excitation light source to irradiate the fluorescent material, transmits the unpolarized fluorescence emitted from the fluorescent material upon irradiation of the excitation light, and reflects the linearly polarized blue light irradiated from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted,
the control method of the projection display device comprises the following steps:
converting the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light; and
the polarization of the linearly polarized blue light reflected by the dichroic mirror is not converted.
Description of the reference symbols
1 fluorescence excitation optical system
1a, 2a blue LD array
1b, 2b blue LD collimation lens
1c, 1d, 1e, 1h, 1i, 2d, 2e, 3a, 3b lens
1f, 2c diffuser plate
1g dichroic mirror
1j fluorescent wheel
2 blue light path
3 fluorescent/blue universal light path
3c, 3d integrator
3e polarization conversion element
4 incident plane
5 exit surface
6 yellow phosphor
7 Motor shaft
11a, 11b, 11c mirrors
30 condenser lens
40 light source device
41 light emitting element
42 collimating lens
43 excitation light source
44 fluorescent substance
45 blue light source
46 polarization conversion part
47 excitation light
48 linearly polarized blue light
49 unpolarized fluorescence
51 polarized light separating film
52 reflective film
53 transparent member
56 lambda/2 phase difference plate
60a, 60b, 60c liquid crystal panel
70 dichroic prism
80 projection lens
100 projection display device
101 unpolarized light
102P polarized light
103S polarized light
S screen
Claims (9)
1. A light source device is characterized by comprising:
an excitation light source that irradiates excitation light;
a phosphor that emits unpolarized fluorescence when the excitation light is irradiated;
a blue light source that irradiates linearly polarized blue light;
a dichroic mirror that reflects the excitation light irradiated from the excitation light source to irradiate the fluorescent material, transmits the unpolarized fluorescence emitted from the fluorescent material upon irradiation of the excitation light, and reflects the linearly polarized blue light irradiated from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted; and
a polarization conversion unit that converts the polarization of the unpolarized fluorescent light transmitted through the dichroic mirror into the same polarization as the linearly polarized blue light without converting the polarization of the linearly polarized blue light reflected by the dichroic mirror,
the polarization conversion unit includes a transparent member and a phase difference plate, the transparent member includes a polarization separation film and a reflection film,
the linearly polarized blue light is reflected at the polarized light separating film and the reflecting film without transmitting through the phase difference plate,
the polarization of the blue light incident to the polarized light separating film is S polarization.
2. The light source device according to claim 1,
the polarization of the blue light incident to the dichroic mirror is S-polarization.
3. The light source device according to claim 1,
the unpolarized fluorescence is separated at the polarized light separation film into fluorescence whose polarization characteristic is P-polarization and fluorescence whose polarization characteristic is S-polarization, and the P-polarized fluorescence is transmitted through the polarized light separation film to be converted into S-polarization at the phase difference plate.
4. The light source device according to claim 1,
the dichroic mirror includes:
a first surface that reflects excitation light emitted from the excitation light source in a direction orthogonal to an incident direction of the excitation light and emits the excitation light to the fluorescent material; and
and a second surface that transmits unpolarized fluorescence emitted from the phosphor and reflects linearly polarized blue light incident from the blue light source in the same direction as the direction in which the unpolarized fluorescence is transmitted.
5. The light source device according to claim 4,
the excitation light source and the blue light source are provided so as to face each other with the first surface and the second surface of the dichroic mirror interposed therebetween.
6. The light source device according to claim 1,
a diffusion member that diffuses the excitation light is provided between the excitation light source and the dichroic mirror.
7. The light source device according to claim 1,
a diffusion member that diffuses the linearly polarized blue light is provided between the blue light source and the dichroic mirror.
8. The light source device according to claim 1,
the fluorescence is yellow light.
9. A projection type display device is characterized in that,
a light source device according to claim 1 is provided.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/JP2017/011809 WO2018173212A1 (en) | 2017-03-23 | 2017-03-23 | Light source device, method for controlling light source device, program, and projection-type display device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212031908U true CN212031908U (en) | 2020-11-27 |
Family
ID=63585188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201790001562.5U Active CN212031908U (en) | 2017-03-23 | 2017-03-23 | Light source device and projection display device |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN212031908U (en) |
| WO (1) | WO2018173212A1 (en) |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5874058B2 (en) * | 2010-12-06 | 2016-03-01 | パナソニックＩｐマネジメント株式会社 | Light source device and projection display device |
| JP5906416B2 (en) * | 2011-06-30 | 2016-04-20 | パナソニックＩｐマネジメント株式会社 | Illumination device and projection display device |
| JP6290523B2 (en) * | 2012-03-02 | 2018-03-07 | セイコーエプソン株式会社 | projector |
| JP2013190674A (en) * | 2012-03-14 | 2013-09-26 | Seiko Epson Corp | Projector |
| JP6303454B2 (en) * | 2013-12-02 | 2018-04-04 | セイコーエプソン株式会社 | Lighting device and projector |
| US9869442B2 (en) * | 2014-06-26 | 2018-01-16 | Texas Instruments Incorporated | Hybrid illumination system having a blue laser diode, dichroic mirror and yellow transmissive phosphor converter for generating white light |
| JP2016066086A (en) * | 2015-11-24 | 2016-04-28 | セイコーエプソン株式会社 | Lighting device and projector |
-
2017
- 2017-03-23 WO PCT/JP2017/011809 patent/WO2018173212A1/en active Application Filing
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| WO2018173212A1 (en) | 2018-09-27 |
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Address after: Tokyo, Japan Patentee after: Sharp NEC display solutions Co.,Ltd. Address before: Tokyo, Japan Patentee before: NEC DISPLAY SOLUTIONS, Ltd. |