JP2015145977A - Light source device and projection type display device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device that can reduce the amount of non-conversion light that returns from a wavelength conversion element to a light source to project brighter images.SOLUTION: A light source device includes a fluorescent material 5 that converts p-polarized light B1p into fluorescent light RG5 having a different wavelength from that of the p-polarized light B1p, and emits the RG5 and non-conversion light having the same wavelength as that of the p-polarized light B1p. The light source device further includes a polarizing plate 2 that has a property to guide, from among the p-polarized light B1p, p-polarized light to the fluorescent material 5 and suppress, from among the non-conversion light, s-polarized light from traveling toward the light source 1. The light source device further includes a mirror 3 that has a property to guide the p-polarized light B1p to the fluorescent material 5 and guide the fluorescent light RG5 to a direction different from the light source 1.

Description

  The present invention relates to a light source device and an image display device using the same. In particular, the invention relates to a light source device using an LD (laser diode) light source and a projection display device such as a projector using the light source device.

  In recent years, a projector capable of displaying a color image using a phosphor that converts blue light from an LD light source into green light and red light has been developed.

  Patent Documents 1 and 2 are examples of such a projector.

  Patent Document 1 discloses a technique for displaying a color image using blue light from an LD light source in addition to green light and red light emitted as fluorescent light. A fluorescent wheel having a diffusion layer capable of transmitting blue light from an LD light source and a fluorescent layer acting as a phosphor is rotated. When the diffusion layer is irradiated with blue light from the LD light source, the blue light passes through the fluorescent layer and is guided to the illumination optical system by the reflection mirror. On the other hand, when the fluorescent layer is irradiated with blue light from the LD light source, green light and red light are emitted in the light source direction and guided to the illumination optical system by the dichroic mirror.

  In Patent Document 2, in addition to green light and red light emitted as fluorescent light, blue light emitted from a blue LED provided separately from the LD light source is used. Thus, a technique for displaying a color image is disclosed.

JP 2011-170362 A JP 2012-8549 A

  As described above, the phosphor converts the wavelength of blue light from the LD light source into the wavelength of green light and red light, but not all blue light is converted in wavelength. In practice, there is also non-converted light that returns from the phosphor to the LD light source without being converted in wavelength by the phosphor.

  In the configurations disclosed in Patent Documents 1 and 2 described above, the non-converted light returns to the LD light source, which may increase the temperature of the LD light source and reduce the light emission efficiency of the LD light source. For this reason, the non-converted light returning to the LD light source may cause a decrease in function such as impairing the brightness of the projected image.

  Therefore, an object of the present invention is to provide a light source device capable of projecting a brighter image by reducing the amount of non-converted light returning from the wavelength conversion element to the light source.

In order to achieve the above object, the light source device of the present invention comprises:
A wavelength conversion element that converts light from a light source into converted light having a wavelength different from that of the light from the light source, and emits the converted light and non-converted light having the same wavelength as the light from the light source;
Of the light from the light source, the light of the first polarization direction is guided to the wavelength conversion element, and the non-converted light of the second polarization direction is different from the light of the first polarization direction. A first optical element having a property of suppressing light from going to the light source;
And a second optical element having a characteristic of guiding light from the light source to the wavelength conversion element and guiding the converted light in a direction different from that of the light source.

  ADVANTAGE OF THE INVENTION According to this invention, the light source device which can reduce the quantity of the non-converted light which returns to a light source from a wavelength conversion element, and can project a brighter image can be provided.

Structure explanatory drawing of the projection type display apparatus which can mount the light source device shown in the Example of this invention Structure explanatory drawing of the light source device shown in 1st Example of this invention Spectral characteristics of light source light and fluorescent light used in the first embodiment of the present invention Spectral reflection characteristics of optical path conversion element used in the first embodiment of the present invention Structure explanatory drawing of the light source device shown in 2nd Example of this invention The figure explaining the form of the perforated mirror used in 2nd Example of this invention Structure explanatory drawing of the light source device shown in 3rd Example of this invention The figure explaining the form of the perforated mirror used in 3rd Example of this invention Structure explanatory drawing of the light source device shown in 4th Example of this invention Spectral reflection characteristic diagram of the mirror 3 used in the fourth embodiment of the present invention

  Preferred embodiments of the present invention will be illustratively described below with reference to the drawings. However, the shapes of components described in this embodiment and their relative arrangements should be changed as appropriate according to the configuration of the apparatus to which the present invention is applied and various conditions. In other words, the shape of the component parts and the like are not stipulated to limit the scope of the present invention to the following embodiments.

[Description of Projection Display Device Configuration]
First, the configuration of a projection display device 100 in which the light source device shown in the embodiment of the present invention can be mounted will be described with reference to FIG.

  The display device (projection display device) 100 includes a light source device 21, a polarizing plate 20, a dichroic mirror 22, a phase difference plate (wavelength selective phase difference plate) 23, and a PBS (polarization beam splitter) 10 (10a, 10a, 10c).

  Further, the display device 100 includes a 1 / 4λ plate 24 (a red 1 / 4λ plate 24r, a green 1 / 4λ plate 24g, and a blue 1 / 4λ plate 24b).

  Further, the display device 100 includes a liquid crystal panel (reflection type liquid crystal panel) 25 (a red liquid crystal panel 25r, a green liquid crystal panel 25g, and a blue liquid crystal panel 25b) which are light modulation elements.

  Further, the display device 100 includes a dichroic prism 26 and a projection lens 30. That is, the display device 100 is a so-called reflective liquid crystal projector.

  The light source device 21 is a light source device shown in any one of the embodiments of the present invention described later.

  The polarizing plate 20 includes s-polarized light 12 (red s-polarized light 12r, green s-polarized light 12g, blue s-polarized light) out of white light 11 (red light 11r, green light 11g, blue light 11b) from the light source device 21. 12b) only is transmitted.

  The dichroic mirror 22 has a reflectance characteristic that transmits light in the green wavelength band and transmits light in the red and blue wavelength bands.

  The phase difference plate 23 transmits polarized light in the blue wavelength band without changing the polarization direction. On the other hand, the polarized light in the red wavelength band is configured to convert the polarization direction by 90 degrees.

  The PBS 10 is configured to reflect s-polarized light and transmit p-polarized light.

  The 1 / 4λ plate 24 is configured to shift the phase of the light incident on the 1 / λ plate 24 by 1 / 4λ.

  The liquid crystal panel 25 converts the polarization direction of the light incident on the liquid crystal panel 25 according to the image signal. Further, the liquid crystal panel 25 emits image light 13 (red image light 13r, green image light 13g, blue image light 13b) that is light whose polarization direction has been converted by the liquid crystal panel 25.

  The dichroic prism 26 has a reflectance characteristic that reflects light in the green wavelength band and transmits light in the red and blue wavelength bands.

  The projection lens 30 is configured to guide the light combined by the dichroic prism 26 to a screen or the like.

  A process until the white light 11 from the light source device 21 reaches the projection lens 30 will be described.

  Of the white light 11 from the light source device 21, only s-polarized light passes through the polarizing plate 20 and is guided to the dichroic mirror 22. Of the s-polarized light 12, the green s-polarized light 12g is reflected and guided to the PBS 10a, and the red s-polarized light 12r and the blue s-polarized light 12b are transmitted through the dichroic mirror 22 and guided to the PBS 10c.

  The green s-polarized light 12g guided to the PBS 10a is reflected by the PBS 10a and guided to the green 1 / 4λ plate 24g. The green s-polarized light 12g has its polarization direction converted by the green liquid crystal panel 25g and is reflected. Of the light from the green liquid crystal panel 25g, p-polarized light is guided to the dichroic prism 26 as green image light 13g.

  Similarly to the green s-polarized light 12g, the red s-polarized light 12r and the blue s-polarized light 12b guided to the PBS 10c are also guided to the dichroic prism 26 as red image light 13r and blue image light 13b.

  By synthesizing the image light 13 guided to the dichroic prism 26 and guiding the synthesized image light 13 to the projection lens 30, a color image can be projected and displayed on a screen or the like.

  Hereinafter, a configuration applicable to the light source device 21 will be described.

  The light source device shown in the embodiment of the present invention includes a light source 1, a polarizing plate (first optical element) 2, a mirror (second optical element) 3, and a phosphor (wavelength conversion element) 5. . Furthermore, the light source device shown in the embodiment of the present invention includes a collimator lens (collimator lens unit) 7 and a condenser lens unit (second lens unit) 4.

  The light source 1 is an LD light source, and emits blue light having a wavelength of 448 nm as shown in FIG. That is, in the embodiment of the present invention, the light from the light source is blue light.

  The phosphor 5 converts light from the light source 1 into fluorescent light (converted light) having a wavelength different from that of the light from the light source 1, and emits fluorescent light and non-converted light having the same wavelength as the light from the light source 1. To do. As shown in FIG. 3B, the fluorescent light is mainly green light and red light.

  The polarizing plate 2 guides the p-polarized light (light having the first polarization direction) out of the light from the light source 1 to the phosphor 5 and the s-polarized light having a polarization direction different from that of the p-polarized light out of the non-converted light. It has the characteristic of suppressing the light (light in the second polarization direction) from going to the light source 1.

  The mirror 3 has a characteristic that guides the light from the light source 1 to the phosphor 5 and guides the fluorescent light in a direction different from that of the light source 1.

  The condenser lens unit 4 is configured to have positive power in order to guide the light from the light source 1 to the phosphor 5 and guide the fluorescent light and the non-converted light to the mirror 3.

  The collimator lens 7 is configured to collimate light from the light source 1.

[First embodiment]
FIG. 2 is a diagram illustrating the configuration of the light source device shown in the first embodiment of the present invention.

  When viewed from the light source 1, each component is arranged in a straight line in the order of the light source 1, the collimator lens 7, the polarizing plate 2, the mirror 3, the condenser lens unit 4, and the phosphor 5. That is, the phosphor 5 is provided in the direction from the light source 1 to the mirror 3. The polarizing plate 2 is provided between the light source 1 and the mirror 3, and the condenser lens unit 4 is provided between the mirror 3 and the phosphor 5.

  Here, when a plane formed by the surface normal of the mirror 3 and the optical axis in FIG. 2 is referred to as a main plane, linearly polarized light that vibrates in the main plane is defined as p-polarized light. Furthermore, linearly polarized light that vibrates perpendicularly to the main plane was defined as s-polarized light. Each polarized light is indicated by ●●● and |||, respectively. In addition, the non-polarized light is illustrated so that both ●●● and ||| Non-polarized light is light in which linearly polarized light, circularly polarized light, elliptically polarized light, and the like are mixed.

  The light source 1 in the present embodiment is an LD, and emits p-polarized light B1p having a wavelength of 448 nm and a main component, which is a p-polarized component, as shown in FIG.

  First, the process until the p-polarized light B1p reaches the phosphor 5 will be described with reference to FIG. The p-polarized light B1p directed from the light source 1 toward the phosphor 5 is converted into substantially parallel light by the collimator lens 7 and enters the polarizing plate 2. In this embodiment, the polarizing plate 2 is a so-called reflective polarizing plate that transmits p-polarized light and reflects s-polarized light. In the present embodiment, the reflective polarizing plate is a wire grid type polarizing plate having a structure (sub-wavelength grating structure) in which metal wires are arranged at intervals narrower than the wavelength of incident light. A wire grid type polarizing plate reflects linearly polarized light that vibrates in parallel to the longitudinal direction of the metal wire and transmits linearly polarized light that vibrates in a direction perpendicular to the longitudinal direction of the metal wire. By this wire grid type polarizing plate, the polarizing plate 2 transmits p-polarized light and reflects s-polarized light as described above.

  The p-polarized light B1p that has passed through the polarizing plate 2 then reaches the mirror 3. As shown in FIG. 4, the mirror 3 is a dichroic mirror having reflectivity characteristics that transmits blue light and reflects visible light having a longer wavelength than the blue light. Therefore, the p-polarized light B 1 p that has passed through the polarizing plate 2 also passes through the mirror 3 and reaches the condenser lens unit 4. The p-polarized light B1p incident on the condenser lens unit 4 is condensed on the surface of the phosphor 5 by the condenser lens unit 4 having a positive power, and the p-polarized light B1p reaches the phosphor 5.

  Next, the phosphor 5 converts part of the p-polarized light B1p into fluorescent light having a wavelength different from that of the p-polarized light B1p, and emits the fluorescent light and non-converted light having the same wavelength as the p-polarized light B1p. Explain up to. The phosphor 5 is mainly composed of a YAG (yttrium / aluminum / garnet) system, and the polarization direction of the light having the spectrum shown in FIG. 3B is disturbed by using the p-polarized light B1p as excitation light. Emitted as unpolarized fluorescent light. That is, in this embodiment, the fluorescent light is green light and red light. Further, not all of the p-polarized light B1p incident on the phosphor is converted into fluorescent light, and there is unconverted light that is not converted with the same wavelength. That is, in this embodiment, the non-converted light is blue light. Further, the phosphor 5 has the property of disturbing the polarization direction of the non-converted light and emitting it as non-polarized light. In addition, since the fluorescent substance 5 is being fixed to the mirror, the metal, etc., there is no light to permeate | transmit and all the light is reflected.

  Next, the process until the fluorescent light RG5 emitted from the phosphor 5 reaches the mirror 3 and is guided to the illumination optical system will be described with reference to FIG. The fluorescent light RG5 and the non-converted light are emitted in random directions without setting the emission direction when going from the phosphor 5 to the condenser lens unit 4. A condensing lens unit 4 is disposed between the phosphor 5 and the mirror 3 in order to convert the fluorescent light and non-converted light emitted in random directions into parallel light and guide the fluorescent light to the mirror 3. As described above, the fluorescent light RG5 is green light and red light, and the mirror 3 reflects visible light having a wavelength longer than that of blue light. Therefore, the fluorescent light RG5 incident on the mirror 3 is reflected by the mirror 3 and guided to an illumination optical system (not shown) provided in a direction different from the light source.

  Next, the process until the non-converted light reaches the mirror 3 and returns to the light source 1 or the phosphor 5 will be described with reference to FIG. As described above, the non-converted light is blue light, and the mirror 3 transmits blue light. Therefore, the non-converted light emitted from the phosphor 5 passes through the mirror 3 and reaches the polarizing plate 5. As described above, since the fluorescent light and the non-converted light are emitted from the phosphor 5 in a non-polarized state, the non-converted light includes p-polarized light B5p and s-polarized light B5s. Since the polarizing plate 2 transmits the p-polarized light and reflects the s-polarized light, the p-polarized light B5p of the non-converted light passes through the polarizing plate 2 and returns to the light source 1. On the other hand, of the non-converted light, the s-polarized light B5s is reflected by the polarizing plate 2, returns to the phosphor 5, and is used again as excitation light.

  Thus, with the configuration shown in the present embodiment, it is possible to provide a light source device that can reduce the amount of non-converted light returning from the phosphor 5 to the light source 1 and project a brighter image. Specifically, by suppressing the s-polarized light B1s from returning to the light source 1 among the non-converted light, the amount of non-converted light returning from the phosphor 5 to the light source 1 can be reduced. Furthermore, with the configuration shown in the present embodiment, it is possible to increase the light utilization efficiency by reusing the s-polarized light B1s suppressed from returning to the light source 1 as excitation light.

[Second Embodiment]
FIG. 5 is a diagram illustrating the configuration of the light source device shown in the second embodiment of the present invention.

  The first difference between the present embodiment and the first embodiment described above is that the light source is a light source group 11 having a plurality of light emitting points, and the collimator lens unit has the same number of collimator lenses as the light sources 1 included in the light source group 11. 7 is a collimator lens group 77 having 7. The second difference is that a perforated mirror 6 is further provided.

  As shown in FIG. 6, the perforated mirror 6 has a region 61 (first region) having a characteristic of guiding the p-polarized light B <b> 1 p from the light source 1 to the phosphor 5. Further, the perforated mirror 6 has a region 62 (second region) having a characteristic of suppressing the p-polarized light B5p transmitted through the polarizing plate 2 from the non-converted light toward the light source 1.

  Further, a perforated mirror 6 is provided in the middle of the optical path from the light source 1 to the polarizing plate 2. That is, a perforated mirror 6 is provided between the light source 1 and the polarizing plate 2.

  First, the process until the p-polarized light B1p reaches the phosphor 5 will be described with reference to FIG.

  In the present embodiment, unlike the first embodiment described above, the p-polarized light B1p does not first enter the polarizing plate 2 but enters the region 61 of the perforated mirror 6 and is guided to the mirror 3. In this embodiment, the region 61 is an opening. The process until the p-polarized light B1p passes through the mirror 3 and reaches the phosphor 5 is the same as in the first embodiment.

  The point that the phosphor 5 converts part of the p-polarized light B1p into fluorescent light having a wavelength different from that of the p-polarized light B1p, and emits the fluorescent light and non-converted light having the same wavelength as the p-polarized light B1p. This is the same as in the first embodiment.

  The point that the fluorescent light emitted from the phosphor 5 reaches the mirror 3 and is guided to the illumination optical system is the same as in the first embodiment.

  Next, the process until the non-converted light reaches the mirror 3 and returns to the light source 1 or the phosphor 5 will be described with reference to FIG. The point that the non-converted light is guided to the mirror 3 by the condenser lens unit 4, passes through the mirror 3, and reaches the polarizing plate 2 is the same as in the first embodiment. Further, in the non-converted light, the s-polarized light B5s is reflected by the polarizing plate 2, returns to the phosphor 5, and is used again as excitation light, as in the first embodiment. In the first embodiment described above, the p-polarized light B5p that has passed through the polarizing plate 2 returns to the light source. Here, in the present embodiment, the region 62 of the perforated mirror 6 is provided with a mirror that reflects visible light regardless of the wavelength. Therefore, in this embodiment, of the p-polarized light B5p, the p-polarized light incident on the area 62 of the perforated mirror 6 is reflected by the mirror provided in the area 62. The reflected p-polarized light returns to the phosphor 5 and is reused as excitation light, similarly to the s-polarized light B5s described above. On the other hand, of the p-polarized light B5p, the p-polarized light incident on the region 61 passes through the region 61 and returns to the light source 1 because the region 61 is an opening.

  Thus, the configuration shown in the present embodiment is a configuration further including the perforated mirror 6 as compared with the first embodiment described above. Even with such a configuration, it is possible to provide a light source device capable of projecting a brighter image by reducing the amount of non-converted light returning from the phosphor 5 to the light source 1. Furthermore, with such a configuration, in addition to the s-polarized light B5s reflected by the polarizing plate 2, the p-polarized light B62p reflected by the region 62 can be reused as excitation light. Therefore, it is possible to realize higher light utilization efficiency as compared with the first embodiment described above.

[Third embodiment]
FIG. 7 is a diagram illustrating the configuration of the light source device shown in the third embodiment of the present invention.

  The difference between the present embodiment and the second embodiment described above is that a compression lens unit (first lens unit) 8 is further provided and the configuration of the perforated mirror 6 is different.

  The compression lens unit 8 includes a total of two lenses, a compression lens 8a and a compression lens 8b, from the side closer to the light source group 11. The compression lens 8a is a lens having positive power and guides light from the light source group 11 to the compression lens 8b. The compression lens 8 b converts light from the compression lens 8 a into substantially parallel light and guides it to the polarizing plate 2. That is, the compression lens unit 8 is an afocal optical system that compresses light from the light source group 11 incident as parallel light into parallel light thinner than that at the time of incidence and guides it to the polarizing plate 2.

  Unlike the second embodiment described above, the perforated mirror 6 in this embodiment has only one region 61 and is located at the center of the perforated mirror 6. The point that the region 61 is provided with an opening and the point that the region 62 is provided with a mirror that reflects visible light regardless of the wavelength are the same as in the second embodiment.

  Also in the present embodiment, a light source device capable of projecting a brighter image by reducing the amount of non-converted light returning from the phosphor 5 to the light source group 11 by the same mechanism as in the second embodiment described above. can do. Further, in addition to the s-polarized light B5s reflected by the polarizing plate 2, the p-polarized light reflected by the region 62 can be reused as excitation light, as in the second embodiment. is there.

  On the other hand, unlike the second embodiment described above, in this embodiment, it is not necessary to provide the same number of regions 61 as the number of light sources 1 included in the light source group 11, so that the perforated mirror 6 can be easily processed. .

[Fourth embodiment]
FIG. 9 is a diagram illustrating the configuration of the light source device shown in the fourth embodiment of the present invention.

  The light source device shown in the present embodiment includes a light source 1, a collimator lens 7, a polarizing plate 2, a mirror 3, a condensing lens unit 4, and a phosphor 5, similarly to the light source device shown in the first embodiment of the present invention. ing.

  The difference between this embodiment and the first embodiment described above is the positional relationship between the light source 1 and the phosphor 5. In the first embodiment described above, the configuration in which the light source 1, the mirror 3, and the phosphor 5 are aligned in a straight line is illustrated. On the other hand, in the present embodiment, a configuration in which the light source 1, the mirror 3, and the phosphor 5 are not aligned is illustrated. That is, the phosphor 5 is provided in the direction in which the light from the light source 1 is reflected by the mirror 3.

  First, the process until the p-polarized light B1p that is the light from the light source 1 reaches the phosphor 5 will be described with reference to FIG. The point that the p-polarized light B1p passes through the polarizing plate 2 and enters the mirror 3 is the same as in the first embodiment. However, in this embodiment, as shown in FIG. 10, the mirror 3 is a dichroic mirror having reflectivity characteristics that reflects blue light and transmits visible light having a longer wavelength than the blue light. Therefore, the p-polarized light B1p that is blue light is reflected by the mirror 3 and guided to the phosphor 5, and the p-polarized light B1p reaches the phosphor 5.

  The point that the phosphor 5 converts part of the p-polarized light B1p into fluorescent light having a wavelength different from that of the p-polarized light B1p, and emits the fluorescent light and non-converted light having the same wavelength as the p-polarized light B1p. This is the same as in the first embodiment.

  Next, the process until the fluorescent light emitted from the phosphor 5 reaches the mirror 3 and is guided to the illumination optical system will be described with reference to FIG. Until the fluorescent light travels from the condenser lens unit 4 to the mirror 3, it is the same as in the first embodiment. As described above, the mirror 3 is a dichroic mirror having reflectivity characteristics that reflects blue light and transmits visible light having a longer wavelength than the blue light. For this reason, the fluorescent light RG5 incident on the mirror 3 passes through the mirror 3 and is guided to an illumination optical system (not shown).

  Next, the process until the non-converted light reaches the mirror 3 and returns to the light source 1 or the phosphor 5 will be described with reference to FIG. The point that the non-converted light reaches the mirror 3 by the condenser lens unit 4 is the same as in the first embodiment. As described above, the mirror 3 is a dichroic mirror having reflectivity characteristics that reflects blue light and transmits visible light having a longer wavelength than the blue light. Therefore, the non-converted light incident on the mirror 3 is reflected by the mirror 3 and guided to the polarizing plate 2. The p-polarized light B5p of the non-converted light is returned to the light source 1 by the polarizing plate 2 and the s-polarized light B5s is reflected and used again as excitation light, as in the first embodiment.

  As described above, the present embodiment shows a configuration in which the phosphor 5 is provided in the direction in which the light from the light source 1 is reflected by the mirror 3. Even with such a configuration, it is possible to provide a light source device capable of projecting a brighter image by reducing the amount of non-converted light returning from the phosphor 5 to the light source 1. Further, the configuration shown in the present embodiment can be applied to the second embodiment and the third embodiment in addition to the first embodiment described above.

[Other Embodiments]
In the above-described embodiments, the configuration of the reflection type liquid crystal projector is exemplified as the configuration of the image display apparatus in which the light source device shown in the embodiments of the present invention can be mounted. However, the present invention is not limited to this. As long as it is an image display device, for example, a projector using a transmissive liquid crystal panel may be used.

  In the above-described embodiments, the configuration in which light from the light source device is first incident on the polarizing plate is exemplified as the configuration of the projection display device on which the light source device shown in the embodiment of the present invention can be mounted. However, the present invention is not limited to this. In the case of a projection display device, for example, instead of a polarizing plate, an integrator using a fly-eye lens and a polarization conversion element that converts non-polarized light into linearly polarized light may be arranged.

  Further, in the above-described embodiment, the configuration including the projection lens is exemplified as the configuration of the projection display device that can mount the light source device shown in the embodiment of the present invention. However, the present invention is not limited to this. If it is a projection type display apparatus, the structure using a detachable projection lens may be used, for example.

  In the above-described embodiment, the configuration of the light source device having no light source that emits blue light other than the LD light source is exemplified, but the present invention is not limited to this. For example, a configuration in which a blue LED light source is added in addition to the LD light source may be used as long as the amount of non-converted light returning to the light source is reduced.

  In the above-described embodiments, the configuration in which the light from the light source is blue light having a wavelength of 448 nm and the main component is a p-polarized component is exemplified, but the present invention is not limited to this. As long as the amount of non-converted light returning to the light source is reduced, the light from the light source may be, for example, a configuration in which the main component is s-polarized light.

  In the above-described embodiment, the configuration including the light source, the collimator lens unit, the compression lens unit, the mirror, the condenser lens unit, and the phosphor is exemplified. However, the present invention is not limited to this. For example, a configuration that does not use the condenser lens unit may be used as long as the amount of non-converted light returning to the light source can be reduced.

  Moreover, in the Example mentioned above, although the structure using a reflective polarizing plate was illustrated, this invention is not limited to this. Any structure that can reduce the amount of non-converted light returning to the light source may be, for example, an absorptive polarizing plate that transmits p-polarized light and absorbs s-polarized light.

  In the above-described embodiments, the configuration including three lenses as the condensing lens unit having positive power is illustrated, but the present invention is not limited to this. As long as the lens unit has a positive power as a whole, for example, a configuration including one, two, or more than three lenses may be used. In addition, the condensing lens unit including three lenses may be one in which three lenses are integrally attached to the light source device or one in which one lens is attached.

  Further, in a part of the above-described embodiments, the configuration of the perforated mirror having a plurality of regions is exemplified, but the present invention is not limited to this. The positions of the plurality of regions may be changed as appropriate according to the position of the light source, for example.

  Moreover, although the Example mentioned above illustrated the structure by which the polarizing plate was provided in the middle of the optical path which goes to a fluorescent substance from a light source, this invention is not limited to this. As long as the amount of non-converted light returning to the light source can be reduced, for example, a configuration in which a polarizing plate is provided in the middle of the optical path from the mirror to the phosphor may be used. In such a configuration, the polarizing plate is configured to transmit p-polarized light for blue light, reflect s-polarized light, and transmit visible light having a wavelength longer than that of blue light regardless of the polarization direction. May be.

  Further, in the above-described embodiments, the configuration of the projection type display device in which the light source device shown in the embodiments of the present invention can be mounted is illustrated, but the present invention is not limited to this. The light source device shown in the embodiment of the present invention may be mounted as, for example, a liquid crystal display or a backlight for an electronic viewfinder.

2 Polarizing plate (first optical element)
3 Mirror (second optical element)
5 Phosphor (wavelength conversion element)

Claims (12)

A wavelength conversion element that converts light from a light source into converted light having a wavelength different from that of the light from the light source, and emits the converted light and non-converted light having the same wavelength as the light from the light source;
Of the light from the light source, the light of the first polarization direction is guided to the wavelength conversion element, and the non-converted light of the second polarization direction is different from the light of the first polarization direction. A first optical element having a property of suppressing light from going to the light source;
A light source device comprising: a second optical element having a characteristic of guiding light from the light source to the wavelength conversion element and guiding the converted light in a direction different from the light source.   2. The light source device according to claim 1, wherein the second optical element is provided in the middle of an optical path from the first optical element toward the wavelength conversion element. A third optical element further comprising: a first region having a characteristic of guiding light from the light source to the wavelength conversion element; and a second region having a characteristic of suppressing the non-converted light from traveling toward the light source. Prepared,
3. The light source device according to claim 1, wherein the third optical element is provided in the middle of an optical path from the light source toward the first optical element.   The first optical element is a reflective polarizing plate that transmits light in the first polarization direction and reflects light in the second polarization direction. The light source device according to item.   4. The absorption element according to claim 1, wherein the first optical element is an absorptive polarizing plate that transmits light in the first polarization direction and absorbs light in the second polarization direction. The light source device according to item.   6. The light source device according to claim 1, wherein the wavelength conversion element is provided in a direction in which light from the light source travels from the light source toward the second optical element.   6. The light source device according to claim 1, wherein the wavelength conversion element is provided in a direction in which light from the light source is reflected by the second optical element. A collimator lens unit that collimates the light from the light source;
8. The apparatus according to claim 1, further comprising a first lens unit configured to convert light from the collimator lens unit into parallel light that is thinner than light from the light source. The light source device according to item.   A second lens unit configured to have positive power to guide light from the light source to the wavelength conversion element and to guide the converted light and the non-converted light to the second optical element; The light source device according to claim 1, further comprising:   The second optical element is configured to guide light having the same wavelength as the light from the light source to the wavelength conversion element, and to guide light having a wavelength different from that of the light from the light source in a different direction from the light source. The light source device according to claim 1, wherein the light source device is a mirror.   11. The light source device according to claim 1, wherein the light in the first polarization direction is p-polarized light, and the light in the second polarization direction is s-polarized light. A light modulation element;
An image display device comprising: an illumination optical system that guides light from the light source device according to any one of claims 1 to 11 to the light modulation element.

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