Light source device and projection display device

Abstract

The present application relates to a light source device and a projection display device. In a light source device in which fluorescent light and a part of blue light emitted from a semiconductor laser are output, a light source device in which the device does not excessively increase in size is sought. The light source device includes: a laser light source that outputs light in a predetermined wavelength region; a first dichroic mirror and a second dichroic mirror that have a characteristic of transmitting fluorescent light while reflecting light in the predetermined wavelength region, and are disposed on an optical axis of the laser light source; a first condensing optical system; a fluorescent color wheel that has a fluorescent light region that emits fluorescent light and a reflection region; a fourth dichroic mirror that has a characteristic of reflecting fluorescent light; a third dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light in the predetermined wavelength region, and is disposed so that an optical axis of the reflected light in the predetermined wavelength region coincides with an optical axis of the fluorescent light reflected by the fourth dichroic mirror; a second condensing optical system; and a light color selection color wheel that has a color filter and a diffusion portion.

Description

TECHNICAL FIELD

[0001] The present application relates to a light source device and a projection display device including the light source device. BACKGROUND

[0002] Conventionally, as a light source for a projection display device, a light source device is known which irradiates blue light (B light) emitted from a semiconductor laser (laser diode or LD) as excitation light onto a phosphor (fluorescent material), and outputs yellow light (Y light), red light (R light), green light (G light), and the like obtained from the phosphor together with a part of the blue light (B light) emitted from the semiconductor laser.

[0003] Patent Document 1 discloses a light source device in which a green light-emitting phosphor, a red light-emitting phosphor, and a transmission window are provided in advance along a circumferential portion of a color wheel, and blue light is irradiated to the circumferential portion while rotating the color wheel. This light source device adopts an optical system in which green and red fluorescent light emitted from the phosphors of the color wheel and blue light transmitted from the transmission window of the color wheel are emitted in the same direction. Specifically, two mirrors are used to guide the blue light transmitted from the transmission window to a dichroic mirror, and the light path of the blue light is merged with the light path of the fluorescent light by the dichroic mirror. In this light source device, since the blue light and the fluorescent light are guided to the dichroic mirror in different light paths, a large light path space needs to be ensured, and it is difficult to achieve a small size of the device. Furthermore, there is a problem that the number of optical components such as mirrors increases.

[0004] Patent Document 2 discloses a light source device in which a green light-emitting phosphor, a red light-emitting phosphor, and a mirror surface portion are provided in advance along a circumferential portion of a color wheel, and blue light is irradiated to the circumferential portion of the color wheel from a blue laser light source (LD array) while rotating the color wheel. In this light source device, a dichroic mirror having a polarization characteristic in a blue wavelength band and a 1 / 4 wavelength plate are disposed between the blue laser light source (LD array) and the color wheel. In this device, the light path of the blue light reflected by the mirror surface portion is made the same as the light path of the fluorescent light by using the polarization characteristic of the laser light source. Therefore, compared with the light source device disclosed in Patent Document 1, miniaturization can be achieved.

[0005] Patent Document 3 discloses a light source device which adopts a structure in which the optical axis of a condensing device to which blue light serving as excitation light is incident and the optical axis of a condensing lens are non-coaxial. In this light source device, the blue light serving as excitation light is reflected by a mirror, and is transmitted from the lower half of the condensing lens and irradiated to the color wheel. The blue light reflected by the reflecting surface of the color wheel is transmitted from the upper half of the condensing lens and guided to a light guide device. Even without using a 1 / 4 wavelength plate as in Patent Document 2, compared with the light source device of Patent Document 1, the device can be miniaturized.

[0006] Patent Document 4 discloses a light source device, like Patent Document 3, adopting a structure in which blue light serving as excitation light is emitted from a laser light source toward an optical axis of a condensing device, and the optical axis of the condensing device is non-coaxial with the optical axis of the condensing device. In this light source device, a dichroic device having two regions with different reflection characteristics is disposed between the laser light source and the fluorescent color wheel. Although it is an optical system of a structure in which blue light and fluorescent light are output at different times, since the optical path of the blue light serving as excitation light and the optical path of the fluorescent light are substantially the same route, compared with the light source device disclosed in Patent Document 1, miniaturization can be achieved.

[0007] Patent Document 5 discloses a light source device, like Patent Document 3, adopting a structure in which blue light serving as excitation light is emitted from a laser light source toward an optical axis of a condensing lens, and the optical axis of the condensing lens is non-coaxial with the optical axis of the condensing lens. In this light source device, after the blue light transmitted from the mirror 20a is reflected by the reflecting surface of the color wheel and then transmitted from the mirror 20a again, the optical path is changed by 270 degrees by reflection by three mirrors, and the optical axis of the blue light is superimposed to coincide with the optical axis of the fluorescent light. Although it is a structure in which a 1 / 4 wave plate like that of Patent Document 2 is not used, since three mirrors are required to change the optical path of the blue light by 270 degrees in space, compared with the devices described in Patent Documents 3 or 4, the effect of miniaturization is less.

[0008] Patent Document 6 discloses a light source device, like Patent Document 3, adopting a structure in which blue light serving as excitation light is emitted from a laser light source toward an optical axis of a condensing lens, and the optical axis of the condensing lens is non-coaxial with the optical axis of the condensing lens. In this light source device, the fluorescent light is reflected by two mirrors, the optical path is changed by 180 degrees, and the optical axis of the fluorescent light is superimposed to coincide with the optical axis of the blue light. Although it is a structure in which a 1 / 4 wave plate like that of Patent Document 2 is not used, since two mirrors are required to change the optical path of the fluorescent light by 180 degrees in space, compared with the device described in Patent Document 4, the effect of miniaturization is less.

[0009] Patent Document 1: Japanese Patent Publication No. 2010-256457

[0010] Patent Document 2: Japanese Patent Publication No. 2012-108486

[0011] Patent Document 3: Japanese Patent Publication No. 2014-75221

[0012] Patent Document 4: Japanese Patent Publication No. 2019-61237

[0013] Patent Document 5: International Publication No. 2019 / 109449

[0014] Patent Document 6: U.S. Patent Application Publication No. 2015 / 0267880

[0015] As described above, the light source device described in Patent Literature 2 can achieve miniaturization compared to the light source device described in Patent Literature 1, but when it is used as an illumination light source of a projector, there is a possibility that degradation of white balance of a projected image occurs. Blue light of P-polarization emitted from the laser light source is converted from P-polarization to S-polarization in a process from passing through the dichroic mirror until being reflected by the fluorescent color wheel to return to the dichroic mirror, but when this polarization conversion is not implemented with high precision, there is a possibility that a polarization component that cannot be emitted as reflected light from the dichroic mirror occurs, light loss of blue light occurs, and degradation of white balance of the projected image occurs.

[0016] Further, if there is a component that is converted from circular polarization to elliptical polarization due to polarization disorder at the condenser lens disposed in front of the fluorescent color wheel, the amount of light reflected as S-polarization light at the dichroic mirror decreases, leading to a decrease in white balance. In order to suppress the occurrence of elliptical polarization, there is a method of using a material with a small coefficient of thermal expansion such as quartz glass in the condenser lens, but such a material is disadvantageous in terms of cost because it is expensive. Also, since the types of optical materials with a small coefficient of thermal expansion are limited, there are problems such as a narrow range of selection of optical materials and a decrease in degree of freedom in optical design.

[0017] In this regard, in the light source devices described in Patent Literatures 3 to 6, since the polarization characteristics of the light source are not used for emission of blue light, the problems that can occur in the light source device described in Patent Literature 2 do not occur, but other problems can occur.

[0018] The light source device described in Patent Literature 3 is simple in structure and achieves miniaturization, but from the distribution of output light on the cross section of the optical path, the fluorescent light is well distributed with respect to the optical axis symmetry of the condenser lens, and in contrast, the blue light for display is distributed only in one half of the condenser lens. Therefore, after being incident to the light guide device (light tunnel), the directivity of the two becomes different, and when the light modulation panel is illuminated, color unevenness (color spots) occurs in the screen. Further, there is a possibility that a part of the output light is lost or the optical path is disturbed at the end portion of the dichroic mirror located near the optical axis of the condenser lens.

[0019] In the light source device described in Patent Literature 4, the structure is such that the blue light reflected by the fluorescent color wheel is incident to the condenser device after being separated into two beams by the dichroic device. However, since the two beams of blue light are not coaxial with the fluorescent light, it is difficult to make the intensity distributions of the two equal, and thus becomes a main cause of color unevenness.

[0020] Moreover, it is difficult to simply manufacture a dichroic device in terms of productivity and cost. For example, when a dichroic device is manufactured in a manner that a dichroic portion and a light splitting portion are bonded adjacently, if the bonding is not performed with extremely high precision, light loss occurs, and it is difficult to achieve the precision by a conventional bonding technique. Furthermore, when the dichroic portion and the light splitting portion are provided integrally instead of being bonded, it is difficult to manufacture the two regions with different transmission characteristics and reflection characteristics at low cost.

[0021] In the light source device described in Patent Document 5, since the blue light reflected by the reflecting surface of the color wheel is reflected by three reflecting mirrors, the optical path is changed by 270 degrees, and the optical axis of the blue light is superimposed on the optical axis of the fluorescent light, so that generation of unevenness in color depth is suppressed. However, since the optical path space for using three reflecting mirrors is required, the device is not sufficiently downsized.

[0022] In the light source device described in Patent Document 6, since the fluorescent light is reflected by two reflecting mirrors, the optical path is changed by 180 degrees, and the optical axis of the fluorescent light is superimposed on the optical axis of the blue light, so that generation of unevenness in color depth is suppressed. However, since the optical path space for using two reflecting mirrors is required, the device is not sufficiently downsized.

[0023] Therefore, in a light source device in which fluorescent light obtained by irradiating blue light emitted from a semiconductor laser to a phosphor as excitation light and a part of the blue light not used as the excitation light are output as illumination light, a light source device in which the device is not excessively large is sought. At the same time, a light source device in which color balance is excellent in in-plane uniformity and light use efficiency is high even if a condensing lens made of quartz glass or the like which is expensive is not used is sought. Furthermore, a projector device provided with such a light source device and capable of obtaining a high-brightness projection image with good white balance is sought. SUMMARY

[0024] A light source device according to a first aspect of the present invention includes: a first laser light source that outputs light in a first wavelength region; a first dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region, and is disposed on an optical axis of the first laser light source; a first condensing optical system; a fluorescent color wheel that is rotatable, and has a fluorescent region that emits fluorescent light when irradiated with light in the first wavelength region, and a reflection region that reflects light in the first wavelength region; a second dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region; a reflection device that has a characteristic of reflecting light in the first wavelength region, and is disposed so that an optical axis of the reflected light in the first wavelength region is parallel to an optical axis of the first condensing optical system; a third dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region; a second condensing optical system; a fourth dichroic mirror that has a characteristic of reflecting fluorescent light, and is disposed so that an optical axis of the reflected fluorescent light is aligned with an optical axis of the second condensing optical system; and a light color selection color wheel that is rotatable in synchronization with the fluorescent color wheel, and has a color filter and a diffusion portion. The first dichroic mirror is disposed so that light in the first wavelength region emitted from the first laser light source is reflected toward a portion of the first condensing optical system. Light in the first wavelength region reflected by the first dichroic mirror is condensed by the portion of the first condensing optical system toward the fluorescent region or the reflection region of the fluorescent color wheel. A portion of the fluorescent light emitted from the fluorescent region is condensed by the portion of the first condensing optical system, and is transmitted from the first dichroic mirror to be incident on the fourth dichroic mirror. Another portion of the fluorescent light emitted from the fluorescent region is condensed by a different portion of the first condensing optical system from the portion, and is transmitted from the second dichroic mirror to be incident on the fourth dichroic mirror. The portion of the fluorescent light and the other portion of the fluorescent light that are incident on the fourth dichroic mirror are reflected toward the third dichroic mirror, and are transmitted from the third dichroic mirror to be incident on the second condensing optical system. Light in the first wavelength region reflected by the reflection region is condensed by a different portion of the first condensing optical system from the portion, and is reflected by the second dichroic mirror to be incident on the reflection device. Light in the first wavelength region that is incident on the reflection device is reflected to be incident on the third dichroic mirror, and is reflected by the third dichroic mirror to be incident on the second condensing optical system. The fluorescent light and light in the first wavelength region that are incident on the second condensing optical system are condensed by the second condensing optical system toward the light color selection color wheel. The light color selection color wheel filters the fluorescent light by the color filter, and diffuses light in the first wavelength region by the diffusion portion, to output.

[0025] A second aspect of the present application is a light source device characterized by comprising: a first laser light source that outputs light in a first wavelength region; a second laser light source that outputs light in a second wavelength region; a first dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region, and is disposed on an optical axis of the first laser light source; a first condensing optical system; a rotatable fluorescent color wheel that has a fluorescent region that emits fluorescent light when irradiated with light in the first wavelength region, and a reflection region that reflects light in the first wavelength region; a second dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region; a reflection device that has a characteristic of reflecting light in the first wavelength region, and is disposed so that an optical axis of the reflected light in the first wavelength region is parallel to an optical axis of the first condensing optical system; a third dichroic mirror that has a characteristic of transmitting light in the second wavelength region and fluorescent light while reflecting light in the first wavelength region; a second condensing optical system; and a fourth dichroic mirror that has a characteristic of transmitting light in the second wavelength region and reflecting fluorescent light, and is disposed so that an optical axis of the reflected fluorescent light is coincident with an optical axis of the second condensing optical system.and a light color selection color wheel capable of rotating in synchronization with the fluorescent color wheel and having a color filter and a diffusion portion, the second laser light source is configured so that an optical axis of the light of the second wavelength region output is coincident with an optical axis of the second condensing optical system, the light of the second wavelength region output from the second laser light source is transmitted from the fourth dichroic mirror and the third dichroic mirror to be incident on the second condensing optical system, the first dichroic mirror is configured so that the light of the first wavelength region emitted from the first laser light source is reflected toward a portion of the first condensing optical system, the light of the first wavelength region reflected by the first dichroic mirror is condensed by the portion of the first condensing optical system to the fluorescent region or the reflection region of the fluorescent color wheel, a portion of the fluorescent light emitted from the fluorescent region is condensed by the portion of the first condensing optical system and transmitted from the first dichroic mirror to be incident on the fourth dichroic mirror, another portion of the fluorescent light emitted from the fluorescent region is condensed by a different portion of the first condensing optical system from the portion and transmitted from the second dichroic mirror to be incident on the fourth dichroic mirror, the portion of the fluorescent light and the other portion of the fluorescent light incident on the fourth dichroic mirror are reflected toward the third dichroic mirror and transmitted from the third dichroic mirror to be incident on the second condensing optical system, the light of the first wavelength region reflected by the reflection region is condensed by a different portion of the first condensing optical system from the portion and reflected by the second dichroic mirror to be incident on the reflection device, the light of the first wavelength region incident on the reflection device is reflected to be incident on the third dichroic mirror and reflected by the third dichroic mirror to be incident on the second condensing optical system, the fluorescent light, the light of the first wavelength region, and the light of the second wavelength region incident on the second condensing optical system are condensed by the second condensing optical system toward the light color selection color wheel, the light color selection color wheel filters the fluorescent light by the color filter and diffuses the light of the first wavelength region and the light of the second wavelength region by the diffusion portion to be output.

[0026] According to the present application, in a light source device in which fluorescent light obtained by irradiating blue light emitted from a semiconductor laser to a phosphor as excitation light is output as illumination light together with a portion of the blue light not used as the excitation light, it is possible to prevent the device from being excessively large. At the same time, it is possible to realize a light source device that is excellent in in-plane uniformity of color balance and high in light use efficiency even without using a condensing lens made of quartz glass or the like that is expensive. Furthermore, it is possible to realize a projector device that has such a light source device and can obtain a high-brightness projection image with good white balance. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1(a) of FIG. 1 is a diagram showing an outline configuration of an optical system of the light source device 100 according to Embodiment 1; Figure 1 (b) of FIG. 1 is a diagram showing a configuration of the blue semiconductor laser and the collimator lens in the laser light source 101B.

[0028] Figure 2 (a) of FIG. 2 is a diagram for explaining a traveling route of the blue light in Embodiment 1; Figure 2 (b) of FIG. 2 is a diagram for explaining a traveling route of the fluorescent light emitted from the phosphor in Embodiment 1.

[0029] Figure 3 (a) of FIG. 3 is a front view of the fluorescent color wheel 120a used in Embodiment 1; Figure 3 (b) of FIG. 3 is a front view of the light color selection color wheel 130a used in Embodiment 1.

[0030] Figure 4 (a) of FIG. 4 is a diagram showing an emission spectrum of the light output from the laser light source 101B in Embodiment 1; Figure 4 (b) of FIG. 4 is a diagram showing an emission characteristic of the phosphor.

[0031] Figure 5 (a) of FIG. 5 is a diagram showing an optical characteristic of the dichroic mirror 201a, 201b, 201c, 201d in Embodiment 1; Figure 5 (b) of FIG. 5 is a diagram showing an optical characteristic of the dichroic mirror 202a in Embodiment 1.

[0032] Figure 6 (a) of FIG. 6 is a diagram showing a range through which the light passes within the first condenser lens system 105 in Embodiment 1; Figure 6 (b) of FIG. 6 is a diagram showing a range through which the light passes within the second condenser lens system 109 in Embodiment 1.

[0033] Figure 7 (a) of FIG. 7 is a diagram showing a state in which the blue light beam is incident on and propagates through the light channel 140 via the light color selection color wheel 130a in Embodiment 1; Figure 7 (b) of FIG. 7 is a diagram showing a state in which the fluorescent light is incident on and propagates through the light channel 140 via the light color selection color wheel 130a in Embodiment 1.

[0034] Figure 8 (a) of FIG. 8 is a diagram showing a relationship between a diffusion function imparted to the diffusion portion of the light color selection color wheel 130a and a light utilization rate in Embodiment 1; Figure 8 (b) of FIG. 8 is a diagram showing an intensity distribution of the blue light diffused by the diffusion portion.

[0035] Figure 9(a) of FIG. 10 is a typical view showing an example of an end configuration of the first dichroic mirror 201a and the second dichroic mirror 201b used in the embodiment; Figure 9 (b) of FIG. 10 is a typical view showing an example of an end configuration of the first dichroic mirror 201a and the second dichroic mirror 201b used in the embodiment.

[0036] Figure 10 FIG. 11 is a view showing an outline configuration of an optical system of the light source device 200 according to Embodiment 2.

[0037] Figure 11 (a) of FIG. 12 is a view showing an outline configuration of an optical system of the light source device 300 according to Embodiment 3; Figure 11 (b) of FIG. 12 is a view for explaining a configuration of the laser light source 101B in Embodiment 3.

[0038] Figure 12 FIG. 13 is a view showing an outline configuration of an optical system of the light source device 400 according to Embodiment 4.

[0039] Figure 13 (a) of FIG. 14 is a view showing an outline configuration of an optical system of the light source device 500 according to Embodiment 5; Figure 13 (b) of FIG. 14 is a view showing a beam profile (Gaussian distribution) of the blue light beam Bout when the diffusion plate 115 is used; Figure 13 (c) of FIG. 14 is a view showing a beam profile of the blue light beam Bout when a top-hat device 116 is used.

[0040] Figure 14 FIG. 15 is a view showing an outline configuration of an optical system of the light source device 600 according to Embodiment 6.

[0041] Figure 15 (a) of FIG. 16 is a view showing an outline configuration of an optical system of the light source device 700 according to Embodiment 7; Figure 15 (b) of FIG. 16 is a view showing a configuration of the blue semiconductor laser and the collimator lens in the laser light source 101B; and (c) of FIG. 16 is a view showing a configuration of the red semiconductor laser and the collimator lens in the laser light source 101R.

[0042] Figure 16 (a) of FIG. 17 is a front view of the fluorescent color wheel 120b used in Embodiment 6; Figure 16 (b) of FIG. 17 is a front view of the light color selection color wheel 130b used in Embodiment 6.

[0043] Figure 17 FIG. 18 is a view showing an optical characteristic of the dichroic mirror 202b in Embodiment 6.

[0044] Figure 18 FIG. 12 is a diagram showing an outline configuration of an optical system of the projection display device 1000 according to Embodiment 8.

[0045] Explanation of Reference Numerals

[0046] 100 …… Light source device

[0047] 101B, 101R …… Laser light sources

[0048] 102 …… Blue semiconductor laser

[0049] 102R …… Red semiconductor laser

[0050] 103 …… Collimator lens

[0051] 105 …… First condenser lens system

[0052] 105A, 105B …… Convex lenses

[0053] 108 …… Condenser lens

[0054] 109 …… Second condenser lens system

[0055] 110 …… Concave lens

[0056] 111 …… Convex lens

[0057] 115 …… Diffusion plate

[0058] 116 …… Flat-top device

[0059] 120a, 120b …… Fluorescent color wheels

[0060] 130a, 130b …… Light color selection color wheels

[0061] 140 …… Light path

[0062] 150 …… Illumination lens

[0063] 160 …… Light modulation device

[0064] 171 …… Prism

[0065] 172 …… Prism

[0066] 180 …… Projection lens

[0067] 190 …… Projection screen

[0068] 200 …… Light source device

[0069] 201a …… First dichroic mirror

[0070] 201b …… Second dichroic mirror

[0071] 201c... third dichroic mirror

[0072] 201d... dichroic mirror

[0073] 202A... fourth dichroic mirror

[0074] 202b... dichroic mirror

[0075] 212... reflecting means

[0076] 300... light source device

[0077] 400... light source device

[0078] 500... light source device

[0079] 502... convex lens

[0080] 503... concave lens

[0081] 504... collimating optical system

[0082] 600... light source device

[0083] 700... light source device

[0084] 1000... projection display device

[0085] PH... fluorescent region

[0086] RL... reflecting region DETAILED DESCRIPTION

[0087] Embodiments of a light source device and a projection display device according to the present application will be described below with reference to the accompanying drawings. The embodiments shown below are illustrative, and for example, the technical solutions in the detailed parts can be appropriately changed by those skilled in the art without departing from the scope of the present application.

[0088] In addition, in the drawings referred to in the description of the embodiments below, units indicated by the same reference numerals have the same function unless otherwise specified.

[0089] Further, in the description below, for example, when indicated as a positive X direction, it means the same direction as the direction indicated by the X axis arrow of the illustrated coordinate system, and when indicated as a negative X direction, it means the opposite direction at 180 degrees from the direction indicated by the X axis arrow of the illustrated coordinate system. Further, when indicated as simply an X direction, it means a direction parallel to the X axis, regardless of whether it is the same direction as the direction indicated by the X axis arrow of the illustrated coordinate system. The same applies to directions other than X.

[0090] [Embodiment 1]

[0091] Figure 1 Figure (a) is a diagram showing the outline structure of the optical system of the light source device according to Embodiment 1. For ease of explanation, the mechanical structure, housing, electrical wiring, etc. used to mount the optical components are omitted in this figure.

[0092] (Structure of the light source device)

[0093] The light source device 100 includes a laser light source 101B, a collimating lens system 504, a first dichroic mirror 201a, a second dichroic mirror 201b, a third dichroic mirror 201c, a fourth dichroic mirror 202a, a first condensing lens system 105 (first condensing optical system) composed of convex lenses 105A and convex lenses 105B, a second condensing lens system 109 (second condensing optical system), a diffuser plate 115, a reflector 212, a rotatable fluorescent color wheel 120a, a rotatable light color selection wheel 130a, and a light channel 140.

[0094] The laser source 101B, for example, employs a blue semiconductor laser 102 with a center wavelength oscillating around 455 nm. Figure 4 Example (a) illustrates the emission spectrum of light output from laser source 101B. Alternatively, a semiconductor laser with a center wavelength outside 455 nm may be used as laser source 101B.

[0095] Each blue semiconductor laser 102 is provided with a collimating lens 103. Generally, the beam emitted by a semiconductor laser has a predetermined angle of expansion. By providing the collimating lens 103, the beam expansion can be suppressed, allowing a roughly parallel beam to exit from the laser source 101B. The collimating lens 103 and the package housing the blue semiconductor laser 102 can be integrated or separate. When separate, lens arrays can be independently configured immediately after multiple blue semiconductor lasers 102 to form a light source module.

[0096] like Figure 1 As shown in (b), in the laser source 101B, the pairing of the blue semiconductor laser 102 and the collimating lens 103 is arranged in an array in the XY plane, emitting a blue beam in the positive Z direction. Figure 1 In (b), a 4×4 array is shown as an example, but the pairing configuration is not limited to this example, and the number of pairs arranged in rows and columns can be changed appropriately.

[0097] The light beam emitted from the laser light source 101B is adjusted in diameter to Dl by the collimator lens system 504 (collimating optical system). The collimator lens system 504 is composed of a convex lens 502 and a concave lens 503 in the drawing, but can be configured in other structures. The output light of the laser light source 101B is used as excitation light for exciting the phosphor and blue light (B) for display. The beam diameter of the excitation light is appropriately set according to the number of arrangement of the blue semiconductor laser 102 used, and the number and material, shape, and other optical specifications of the lenses configuring the collimator lens system and the arrangement interval are appropriately designed in correspondence thereto.

[0098] In Figure 1 (a), the optical axis of the collimator lens system 504 is denoted as an optical axis OXl. The optical axis OXl of the collimator lens system 504 is set to be perpendicular to the cross section of the entire light beam emitted from the laser light source 101B and to pass through the center. In addition, as described later with reference to Figure 11 (a) and Figure 11 (b), if the laser light source 101B can output a light beam of Dl in diameter and substantially parallel, the collimator lens system 504 is not necessarily required to be provided. In this case, an axis that is perpendicular to the cross section of the entire light beam emitted from the laser light source 101B and passes through the center is defined as the optical axis OXl.

[0099] On the optical axis OXl, a first dichroic mirror 201a is disposed at an angle of 45 degrees with respect to the optical axis OXl. In Figure 5 (a), the optical characteristics of the first dichroic mirror 201a are shown in a solid line. For reference, blue light (B light) of a wavelength around 445 nm is shown in a broken line in the drawing, and the first dichroic mirror 201a has optical characteristics of reflecting the blue light (B light) and transmitting green light (G light) or red light (R light) or yellow light (Y light) containing both of the lights. The first dichroic mirror 201a having such characteristics can be formed, for example, by evaporating a dielectric multilayer film on a transparent glass substrate or the like.

[0100] The output light of the laser light source 101B is reflected by the first dichroic mirror 201a, and a first condensing lens system 105 (first condensing optical system) composed of a convex lens 105A and a convex lens 105B is provided on the optical path thereof. The first condensing lens system 105 can condense the output light of the laser light source 101B onto the phosphor wheel 120a. In Figure 1In the example of FIG. 10, the first condensing lens system 105 is composed of two convex lenses 105A and 105B, but the structure of the first condensing lens system 105 is not limited to this example and can be composed of one or more than three lenses. In addition, the shape, material, and the like of the lenses can be appropriately selected. That is, lenses other than spherical lenses, such as aspherical lenses or free-form lenses, can be used. If an optical material such as BK7, which is inexpensive, is used, the light source device can be provided at a low cost.

[0101] In the present embodiment, the optical axis OX1 and the optical axis OX2 of the first condensing lens system 105 are orthogonal to each other. Also, each optical component is configured so that the output light of the laser light source 101B passes through the region of the left half (the half on the negative side in the Z direction) of the convex lens 105A and the convex lens 105B that constitute the first condensing lens system 105 when the output light of the laser light source 101B is emitted toward the fluorescent color wheel 120a after being reflected by the first dichroic mirror 201a. That is, the blue light after being reflected by the first dichroic mirror 201a is partially condensed by the first condensing lens system 105.

[0102] At the condensing position of the first condensing lens system 105, the fluorescent color wheel 120a is disposed. The fluorescent color wheel 120a is disposed at a position where the output light of the laser light source 101B is condensed by the first condensing lens system 105. Figure 3 A front view of the fluorescent color wheel 120a is shown in (a) of FIG. 12. The fluorescent color wheel 120a has a glass plate or a metal plate in a circular plate shape as a base material, and a fluorescent region PH and a reflection region RL are provided on the surface near the circumference thereof. The fluorescent region PH is coated with a phosphor, and emits red (R), green (G), or yellow (Y) fluorescent light depending on the type of the phosphor when irradiated with excitation light (the output light of the laser light source 101B). The reflection region RL is a region for reflecting the output light of the laser light source 101B, and is not coated with a phosphor. The reflection region RL is preferably mirror-finished in advance to efficiently reflect blue laser light.

[0103] The base material of the fluorescent color wheel 120a is preferably a metal having high thermal conductivity, and a concave-convex portion or a hole can be provided in the base material in order to improve the air cooling efficiency. The fluorescent color wheel 120a is connected to a motor, and the motor rotates around the rotation axis C1, thereby causing the blue light condensed on the fluorescent color wheel 120a to sequentially irradiate the reflection region RL and the fluorescent region PH. In this way, the fluorescent color wheel 120a functions as a color wheel that changes the color of the light emitted from the light source device 100. Figure 3 In the example of (a) of FIG. 12, the fluorescent region PH is divided and coated with a G phosphor, an R phosphor, and a Y phosphor, but it is not necessary to divide and coat the three types of phosphors, and the material and the method of division and coating can be appropriately changed depending on the specifications of the light source device 100.

[0104] In the example of FIG. 13, the fluorescent color wheel 120a is composed of a glass plate or a metal plate in a circular plate shape as a base material, and a fluorescent region PH and a reflection region RL are provided on the surface near the circumference thereof. The fluorescent region PH is coated with a phosphor, and emits red (R), green (G), or yellow (Y) fluorescent light depending on the type of the phosphor when irradiated with excitation light (the output light of the laser light source 101B). The reflection region RL is a region for reflecting the output light of the laser light source 101B, and is not coated with a phosphor. The reflection region RL is preferably mirror-finished in advance to efficiently reflect blue laser light. Figure 4Example (b) illustrates the emission spectrum of a phosphor. Specifically, dashed line 31 shows the emission spectrum of phosphor G, dotted line 32 shows the emission spectrum of phosphor Y, and solid line 33 shows the emission spectrum of phosphor R. In each curve, there is also a peak at the position corresponding to the wavelength of blue light used as excitation light, but this does not originate from the emission of the phosphor, but rather indicates that a portion of the blue light is scattered by the phosphor and not used for excitation. Furthermore, Figure 4 (b) is an example, and the phosphor used in the embodiments is not limited to materials with this luminescent property.

[0105] Back Figure 1 (a) When viewed along the optical axis OX2 of the first condenser lens system 105, a fourth dichroic mirror 202a is disposed in front of the first dichroic mirror 201a and the second dichroic mirror 201b. The reflecting surface of the fourth dichroic mirror 202a is disposed at an angle of 45 degrees relative to the optical axis OX2 of the first condenser lens system 105.

[0106] exist Figure 5 In (b), the optical characteristics of the fourth dichroic mirror 202a are shown in solid lines. For reference, blue light (B light) with a wavelength around 445 nm is shown in dashed lines in this figure. The fourth dichroic mirror 202a has the optical characteristic of reflecting green light (G light) or red light (R light) or yellow light (Y light) containing both of these. That is, the fourth dichroic mirror 202a has the optical characteristic of reflecting the fluorescence emitted by the fluorescent color wheel 120a. The fourth dichroic mirror 202a with this characteristic can be formed, for example, by depositing a dielectric multilayer film on a transparent glass substrate or the like.

[0107] Back Figure 1 In (a), separated by a first condenser lens system 105, a second dichroic mirror 201b is disposed on the opposite side of the fluorescent color wheel 120a, tilted at 45 degrees relative to the optical axis OX2. The second dichroic mirror 201b, like the first dichroic mirror 201a, has the following characteristics: Figure 5 The optical characteristics are shown in solid lines in (a). That is, the second dichroic mirror 201b has the optical characteristics of reflecting blue light (B light) while transmitting green light (G light) or red light (R light) or yellow light (Y light) containing both of these. The second dichroic mirror 201b having this characteristic can be formed, for example, by depositing a dielectric multilayer film on a transparent glass substrate or the like.

[0108] In the optical path of the blue light (B light) reflected by the second dichroic mirror 201b, a reflecting device 212 is arranged parallel to the second dichroic mirror 201b. In other words, when viewed along the optical axis OX1 of the collimating lens system 504, the reflecting device 212 is arranged parallel to the second dichroic mirror 201b, further in front of it.

[0109] The reflection device 212 is a mirror that reflects blue (B) light. The reflection device 212 preferably has a reflectance of 95% or more for blue (B) light, and can be produced, for example, by forming a dielectric multilayer film on a glass substrate or the like. Alternatively, a reflection film can be formed on a mirror substrate using AL evaporation or the like. The reflection device 212 is disposed so that the center (optical axis) of the blue light beam after reflection coincides with the center (optical axis) of the fluorescent light beam after reflection by the fourth dichroic mirror 202a on the third dichroic mirror 201c.

[0110] The third dichroic mirror 201c, like the first dichroic mirror 201a and the second dichroic mirror 201b, has an optical characteristic shown by a solid line in (a) of FIG. 10. That is, the third dichroic mirror 201c has an optical characteristic that reflects blue light (B light) and transmits green light (G light) or red light (R light) or yellow light (Y light) containing both of these lights. The third dichroic mirror 201c having such a characteristic can be formed, for example, by evaporating a dielectric multilayer film on a transparent glass substrate or the like. Figure 5

[0111] The blue (B) light after reflection by the reflection device 212 is reflected by the third dichroic mirror 201c and advances in the positive Z direction, and on its advancing route, the second condensing lens system 109 (second condensing optical system) is disposed. The second condensing lens system 109 is configured so that its optical axis OX3 coincides with the center axis of the blue (B) light beam and the center axis of the fluorescent light beam. The second condensing lens system 109 is set to a predetermined NA so as to match the F value of the projection lens 180 (described later) of the display device, which condenses the blue (B) light and the fluorescent light toward the entrance of the light tunnel 140. The second condensing lens system 109 is typically shown as a single convex lens in the figure, but is not limited to a single lens in practice, and can be composed of a plurality of lenses. Figure 18 ) of the display device described later, and condenses the blue (B) light and the fluorescent light toward the entrance of the light tunnel 140. The second condensing lens system 109 is typically shown as a single convex lens in the figure, but is not limited to a single lens in practice, and can be composed of a plurality of lenses.

[0112] Between the second condensing lens system 109 and the light tunnel 140, the light color selection color wheel 130a is disposed. The light color selection color wheel 130a is connected to a motor, and the motor rotates about the rotation axis C2, thereby rotating the light color selection color wheel 130a. Each motor is controlled so that the light color selection color wheel 130a rotates in synchronization with the fluorescent color wheel 120a.

[0113] A front view of the light color selection color wheel 130a is shown in (b) of FIG. 10. On the light color selection color wheel 130a, a filter portion and a diffusion portion are disposed. Figure 3

[0114] ​​The filter section includes optical filters for removing unwanted spectral components from fluorescence. For example, the R filter section includes an optical filter for improving the color purity of red by removing unwanted spectral components from the fluorescence emitted by the R phosphor region of the fluorescence color wheel 120a. Similarly, the G filter section includes an optical filter for improving the color purity of green by removing unwanted spectral components from the fluorescence emitted by the G phosphor region of the fluorescence color wheel 120a, and the Y filter section includes an optical filter for improving the color purity of yellow by removing unwanted spectral components from the fluorescence emitted by the Y phosphor region of the fluorescence color wheel 120a. Furthermore, the filter section does not have the function of diffusing transmitted fluorescence.

[0115] Furthermore, section B is equipped with a diffusion surface for properly diffusing the blue light beam. The function and effect of the diffusion section will be described in detail later.

[0116] (Operation of the light source device)

[0117] The operation of the light source device 100 having the above structure will now be explained.

[0118] (Blue light output in operation)

[0119] First, the operation of the device during the period when blue light (B-color light) is output from the laser source 101B and irradiates the reflection region RL of the fluorescent color wheel 120a will be explained.

[0120] Figure 2 (a) is a diagram used to illustrate the path of blue light (B color light) output from laser source 101B. Figure 2 (a) shows the state in which blue light (B color light) output from the laser source 101B is input to the light channel 140 as a blue light (B color light) component for image display during the period when the reflective region RL of the fluorescent color wheel 120a is illuminated. Additionally, as referenced later... Figure 2 As illustrated in (b), the blue light (B-color light) emitted from the laser source 101B during the period when the fluorescent region PH of the fluorescent color wheel 120a is irradiated serves as the excitation light for exciting the phosphor.

[0121] First, in the laser source 101B, the blue laser beams output from each blue semiconductor laser 102 are collimated to be approximately parallel by the collimating lens 103. Since the laser beams travel parallel to each other with gaps between them, they can strictly be called a spatially discrete group of laser beams. However, since each blue semiconductor laser 102 is arranged very close together, the group of laser beams can also be treated as a single beam. That is, the laser source 101B can be considered as a source emitting a single blue beam.

[0122] The blue beam is collimated by the collimating lens system 504, which adjusts its beam diameter to D1, and propagates along the optical axis OX1. The blue beam passing through the collimating lens system 504 is incident on the first dichroic mirror 201a. Since the first dichroic mirror 201a, as previously described, has... Figure 5 As shown in (a), the blue beam is reflected and directed toward the first condenser lens system 105, with the optical path deflected by 90 degrees.

[0123] If the blue light beam (B color light) reflected by the first dichroic mirror 201a is designated as Bin, then the blue light beam Bin is focused onto the reflection area RL on the fluorescent color wheel 120a by the focusing effect of the first focusing lens system 105 (convex lens 105a, convex lens 105b).

[0124] In this embodiment, the optical axis OX2 of the first condenser lens system 105 and the optical axis of the blue beam Bin are set to be non-coaxial, i.e., offset from each other. This is to ensure that the blue light reflected by the reflective region RL of the phosphor color wheel 120a can be emitted without loss as blue light (B color light) for image display. In addition, the reflective region RL is set such that the normal to the reflective surface is parallel to the optical axis OX2 of the condenser lens system 105.

[0125] exist Figure 6 (a) shows the range through which light passes within the first condenser lens system 105. As... Figure 2 (a) and Figure 6 As shown in (a), the blue beam Bin traveling toward the fluorescent color wheel 120a passes through the left half of the first condenser lens system 105, that is, the region on the negative Z direction side of the optical axis OX2 of the condenser lens system 105 (a part of the condenser lens).

[0126] On the other hand, if the blue beam (B color light) reflected by the reflection region RL of the fluorescent color wheel 120a is designated as Bout, then the blue beam Bout will not travel in reverse along the same path as the blue beam Bin and pass through the left half of the first condenser lens system 105. For example... Figure 2 (a) and Figure 6 As shown in (a), the blue beam Bout passes through the right half of the first condenser lens system 105, that is, the region on the positive Z-direction side of the optical axis OX2 of the first condenser lens system 105 (the part that is different from the part through which the blue beam Bin passes).

[0127] After the blue beam Bout is restored by the first focusing lens system 105 to have the same beam diameter D1 as the blue beam Bin, it propagates in the positive X direction and is incident on the second dichroic mirror 201b. Since the second dichroic mirror 201b, as previously described, has… Figure 5of (a), so the blue light beam Bout is reflected toward the reflecting means 212.

[0128] The blue light beam Bout passes through the diffusion plate 115 before reaching the reflecting means 212. After passing through the diffusion plate 115, the blue light beam Bout becomes a light beam whose diameter expands as it advances, rather than a parallel light beam. That is, the blue light beam is made to expand in diameter as it advances toward the second condensing lens system 109 after being reflected by the reflecting means 212 and the third dichroic mirror 201c.

[0129] As described above, the reflecting means 212 is a mirror having an optical characteristic of reflecting blue light, and is disposed in parallel with the fourth dichroic mirror 202a at a position at which the center (optical axis) of the blue light beam after reflection and the center (optical axis) of the fluorescent light beam after reflection by the fourth dichroic mirror 202a coincide on the third dichroic mirror 201c.

[0130] The blue light beam after reflection by the reflecting means 212 is reflected by the third dichroic mirror 201c to advance in the positive Z direction. On the advancing route thereof, the second condensing lens system 109 (second condensing optical system) is disposed. The second condensing lens system 109 is disposed so that its optical axis OX3 coincides with the center of the blue light beam.

[0131] Figure 6 (b) is a typical view showing a portion of the second condensing lens system 109 in which the light beam enters. The diameter of the blue light beam Bout is D2, and the center axis of the light beam coincides with the optical axis OX3 of the second condensing lens system 109. Since the diameter of the blue light beam Bout is expanded by the diffusion plate 115, D2 > Dl holds. That is, when passing through the second condensing lens system 109, the difference between the diameter of the blue light beam and the diameter of the fluorescent light beam is reduced as compared with the point of transmission from the first condensing lens system 105.

[0132] The second condensing lens system 109 is set to a predetermined NA so as to conform to the F value of the projection lens 180 (described later) of the display device. Figure 18 The blue light beam Bout having a beam diameter of D2 is condensed by the second condensing lens system 109 toward the entrance of the light tunnel 140.

[0133] The light path of the fluorescent light emitted from the fluorescent region PH of the fluorescent color wheel 120a will be described later, as Figure 6The blue light beam Bout incident to the second condenser lens system 109 is coaxial with the fluorescent light beam indicated by a broken line as shown in (b) of FIG. 12, but if the beam diameters are compared, the blue light beam Bout is smaller in diameter than the fluorescent light. The fluorescent light emitted from the fluorescent region PH of the fluorescent color wheel 120a is Lambertian emission because the fluorescent light is emitted at a larger angular range than the blue light reflected by the reflection region RL.

[0134] In this way, the distribution of the incident angles (convergence angles) when the blue light beam Bout is incident to the entrance of the light tunnel 140 and the distribution of the incident angles (convergence angles) when the fluorescent light condensed by the second condenser lens system 109 is incident to the entrance of the light tunnel 140 can differ due to the difference in the beam diameters at the time of incidence to the second condenser lens system 109. If the distributions of the incident angles (convergence angles) differ, the distributions of the exit angles (divergence) of the blue light and the fluorescent light at the time of emission from the exit of the light tunnel 140 differ, which can cause color unevenness in the display screen when the light is used as illumination light for a projection display device.

[0135] Therefore, in the present application, an optical unit that diffuses the blue light beam Bout but does not diffuse the fluorescent light is provided between the fluorescent color wheel 120a and the entrance of the light tunnel 140, thereby reducing the difference in the distribution of the incident angles (convergence angles) at the time of incidence to the entrance of the light tunnel 140 and suppressing the generation of color unevenness. In Embodiment 1, this function is imparted to the light color selection color wheel 130a disposed between the second condenser lens system 109 and the entrance of the light tunnel 140.

[0136] Figure 7 (a) of FIG. 13 shows a state in which the blue light beam is incident to the light tunnel 140 via the light color selection color wheel 130a and propagates, Figure 7 (b) of FIG. 13 shows a state in which the fluorescent light is incident to the light tunnel 140 via the light color selection color wheel 130a and propagates. As is apparent from these figures, the convergence angle ain(blue) of the blue light condensed by the second condenser lens system 109 when directed toward the light color selection color wheel 130a is smaller than the convergence angle ain(fluorescent) of the fluorescent light condensed by the second condenser lens system 109 when directed toward the light color selection color wheel 130a. However, as described with reference to Figure 3 (b), in the light color selection color wheel 130a of the present embodiment, a diffusion portion that diffuses the light beam appropriately is provided in the portion through which the blue light is transmitted, and a color filter portion that filters to remove unnecessary spectral components but does not have a diffusion effect is provided in the portion through which the fluorescent light is transmitted. Therefore, the blue light beam is diffused by the diffusion portion as shown in (a) of FIG. 13 and is incident to the light tunnel 140, and on the other hand, the fluorescent light is not diffused by the color filter portion as shown in (b) of FIG. 13 and is incident to the light tunnel 140. Figure 7 Figure 7 ​of (b) of FIG. 13. As a result, the difference between the spread angle aout(blue) when the blue light is emitted from the light passage 140 and the spread angle aout(fl uorescent) when the fluorescent light is emitted can be reduced compared to the difference between the convergence angle ain(blue) and the convergence angle ain(fl uorescent).

[0137] In Figure 8 FIG. 13 (a) shows the relationship between the diffusion function imparted to the diffusion section and the light utilization rate. The intensity distribution of the blue light diffused by the diffusion section is shown in FIG. 13 (b) as a Gaussian distribution. Figure 8 If the diffusion function is set too large, the light outside the 1 / e2 outside set angle cannot be effectively incident to the light passage 140, and the light loss increases, so as shown in FIG. 13 (b), the light utilization rate decreases. Figure 8 As shown in FIG. 13 (a), the light utilization rate decreases. Therefore, the diffusion function of the diffusion section is appropriately set in consideration of the balance between the suppression effect of the color unevenness in the display screen and the securing of the light utilization rate of the blue light.

[0138] (Operating when the fluorescent light is output)

[0139] Next, the operation when the light source device 100 outputs the fluorescent light will be described. That is, the device operation of the period when the blue light (B color light) is output from the laser light source 101B and the blue light (B color light) irradiates the fluorescent region PH of the fluorescent color wheel 120a will be described.

[0140] Figure 2 (b) of FIG. 14 is a view for describing the traveling route of the fluorescent light output from the fluorescent color wheel 120a, and shows a state in which the fluorescent light emitted from the fluorescent region PH is input to the light passage 140 as illumination light for image display. The spectrum of the fluorescent light differs depending on the period in which the fluorescent region PH of which fluorescent body region is G, Y, or R emits light, but in Figure 2 The light path shown by the dotted line in (b) of FIG. 14 is common to each color. In addition, the operation of the blue light as excitation light from the laser light source 101B to the fluorescent color wheel 120a is the same as described in the description of the output operation of the blue light in Figure 2 (b) of FIG. 14. In Figure 2 (b) of FIG. 14, the route of the blue light is omitted from the illustration.

[0141] In Figure 2 (b) of FIG. 14, the light path of the fluorescent light emitted from the fluorescent region PH is typically shown by a dotted line, and the fluorescent light is emitted from the fluorescent region PH toward the entire first condenser lens system 105 in a wide angular range since it is Lambertian emission. That is, as shown in Figure 6As shown by the broken line in (a) of FIG. 10, the fluorescence passes through substantially the entire area of the first condenser lens system 105. The fluorescence condensed by the first condenser lens system 105 becomes a parallel light beam advancing in the positive X direction, and the light beam passing through the left side (negative Z direction side) of the optical axis OX2 of the first condenser lens system 105 is incident on the first dichroic mirror 201a. Since the first dichroic mirror 201a has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the first dichroic mirror 201a and is incident on the fourth dichroic mirror 202a. Figure 5 As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109.

[0142] On the other hand, among the fluorescence, the light beam passing through the right side (positive Z direction side) of the optical axis OX2 of the first condenser lens system 105 is incident on the second dichroic mirror 201b. Since the second dichroic mirror 201b has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the second dichroic mirror 201b and is incident on the fourth dichroic mirror 202a. Figure 5 As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109.

[0143] As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109. Figure 5 As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109. Figure 5 As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109.

[0144] As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109. Figure 6 As shown in (a) of FIG. 10, the fourth dichroic mirror 202a has the optical characteristic of reflecting each of the colors of green (G), red (R), and yellow (Y) as shown in (b) of FIG. 10, and thus the direction of travel of the fluorescence is deflected by 90 degrees and advances in the positive Z direction toward the third dichroic mirror 201c. Since the third dichroic mirror 201c has the optical characteristic of transmitting each of the colors of green (G), red (R), and yellow (Y) as shown in (a) of FIG. 10, the fluorescence is transmitted from the third dichroic mirror 201c and is incident on the second condenser lens system 109.

[0145] Figure 7(b) shows the state in which fluorescence is incident on the light channel 140 via the light color selection wheel 130a and propagates. In this embodiment, the light color selection wheel 130a is provided with a filter portion in the fluorescence transmission section that removes unwanted spectral components but does not have a diffusion effect. Therefore, fluorescence is incident on the light channel 140 without being diffused. As already explained, in this embodiment, the difference between the expansion angle αout (blue) when blue light is emitted from the light channel 140 and the expansion angle αout (fluorescence) when fluorescence is emitted is reduced, thus suppressing in-plane color unevenness when used as illumination light for a projection display device.

[0146] Here, as a supplementary explanation, the first dichroic mirror 201a and the second dichroic mirror 201b, which are symmetrically arranged across the optical axis OX2, will be described. Figure 9 (a) is a typical diagram showing an example of the end shape. Figure 9 (b) is a typical diagram showing an example of a more preferred end shape.

[0147] exist Figure 9 In the example shown in (a), the first dichroic mirror 201a and the second dichroic mirror 201b are plate-shaped components with their sides SA positioned approximately perpendicular to the main surface (optical surface). Generally, it is difficult to create a homogeneous optical surface on the side of such a plate as the main surface, therefore no optical treatment is applied to the side SA. Figure 9 As shown in (a), most of the fluorescence incident on the first dichroic mirror 201a from the main surface (optical surface) on the side of the first condenser lens system 105 can pass through the main surface (optical surface) on the side of the fourth dichroic mirror 202a and propagate in the positive X direction. However, fluorescence incident on the first dichroic mirror 201a near the optical axis OX2 of the first condenser lens system 105 reaches the side SA, which has not undergone optical processing. The fluorescence cannot pass through the side SA, which has not undergone optical processing, and propagate in the positive X direction, resulting in a loss that prevents it from being used as illumination light. The same applies to the second dichroic mirror 201b.

[0148] Therefore, in Figure 9 In the example shown in (b), the shape (or orientation) of the side surfaces SB of the first dichroic mirror 201a and the second dichroic mirror 201b is adjusted to reduce fluorescence reaching the side surfaces SB, thereby suppressing fluorescence loss. Specifically, the side surfaces SB of the first dichroic mirror 201a and the second dichroic mirror 201b are arranged parallel to the optical axis OX2 of the first condenser lens system 105 and abut against each other along the optical axis OX2. More specifically, the angle formed between the principal surface (optical surface) of the first condenser lens system 105 and the side surface SB is made acute (e.g., 45 degrees), and the angle formed between the principal surface (optical surface) of the fourth dichroic mirror 202a and the side surface SB is made obtuse (e.g., 135 degrees).Figure 9 In the example shown in (b), the fluorescence utilization efficiency and in-plane uniformity of color balance can be further improved by suppressing the losses on the sides of the first and second dichroic mirrors.

[0149] As described above, according to this embodiment, in a light source device that outputs illumination light as a portion of the blue light emitted by a semiconductor laser and fluorescence that is not used as excitation light, the first dichroic mirror 201a and the second dichroic mirror 201b are symmetrically arranged across the optical axis OX2 of the first condenser lens system 105, wherein fluorescence is obtained by irradiating a phosphor with blue light emitted by a semiconductor laser as excitation light. Furthermore, by configuring a structure that guides the blue light not used as excitation light and fluorescence to the second condenser lens system 109 using different optical paths, excessively large device size can be prevented. Since this embodiment does not employ polarization control using a quarter-wave plate or similar material, even without using expensive condenser lenses such as those made of quartz glass, a light source device with excellent in-plane color balance uniformity and high light utilization efficiency can be achieved.

[0150] [Implementation Method 2]

[0151] Figure 10 This is a diagram showing the outline structure of the optical system of the light source device according to Embodiment 2. For ease of explanation, the mechanical structure, housing, electrical wiring, etc., used to mount the optical components are omitted in this diagram.

[0152] The light source device 200 of Embodiment 2 is a modification of a part of the light source device 100 of Embodiment 1. For matters common to the description of Embodiment 1, the description is simplified or omitted.

[0153] (Structure of the light source device)

[0154] The light source device 200 in this embodiment, like that in embodiment 1, includes a laser light source 101B, a collimating lens system 504, a first dichroic mirror 201a, a fourth dichroic mirror 202a, a first condensing lens system 105 (first condensing optical system) composed of convex lenses 105A and convex lenses 105B, a second condensing lens system 109 (second condensing optical system), a diffuser plate 115, a reflector 212, a rotatable fluorescent color wheel 120a, a rotatable light color selection wheel 130a, and a light channel 140.

[0155] In Embodiment 1, the second dichroic mirror 201b and the third dichroic mirror 201c, which have the same optical properties, are separately arranged, except for the structural unit described above. However, in this embodiment, they are integrated as a single dichroic mirror 201d. That is, the dichroic mirror 201d of this embodiment has... Figure 5 The optical properties shown in (a) are as follows.

[0156] As for the operation of the light source device 200, the same as Embodiment 1 is applied, and the description is omitted.

[0157] According to the present embodiment, the same effects as Embodiment 1 can be achieved, and the number of components can be reduced. If the second dichroic mirror 201b and the third dichroic mirror 201c are provided separately, they can be affected by the characteristic deviation in manufacturing, the relative positioning error, but in the present embodiment, since they are provided integrally, there is no such concern.

[0158] [Embodiment 3]

[0159] Figure 11 (a) of FIG. 1 is a diagram showing the outline structure of the optical system of the light source device according to Embodiment 3. For the convenience of explanation, the mechanical structure for arranging the optical components, the chassis, the electrical wiring, and the like are omitted in the diagram.

[0160] The light source device 300 of Embodiment 3 has parts in common with the light source device 200 of Embodiment 2, and for the parts in common, the description is simplified or omitted.

[0161] (Structure of the light source device)

[0162] In Embodiment 2, as the laser light source 101B, a laser light source in which blue semiconductor lasers 102 are arranged in an array of 4 x 4, for example, is used, and a blue light beam with a large diameter is output from the laser light source 101B. Further, a collimator lens system 504 (collimating optical system) is used to adjust the light beam diameter to Dl, and a parallel light beam is obtained.

[0163] In contrast, in the present embodiment, the size of the laser light source 101B is set to output a parallel light beam with a light beam diameter of Dl. In this way, the collimator lens system 504 (collimating optical system) is not required, and the position of the laser light source 101B is brought close to the first dichroic mirror side (positive Z direction side). Figure 11 The structure of the laser light source 101B of the present embodiment is shown in (b) of FIG. 1. In addition, the blue semiconductor lasers 102 can not necessarily be arranged in a 2 x 2 array as shown in the figure, as long as a parallel light beam with a light beam diameter of Dl can be output.

[0164] By using such a laser light source 101B, the collimator lens system 504 (collimating optical system) is not required, and the position of the laser light source 101B is brought close to the first dichroic mirror side (positive Z direction side).

[0165] According to the present embodiment, the same effects as Embodiment 2 can be achieved, and the number of components can be reduced. Furthermore, the light source device can be made compact from the Z direction.

[0166] [Embodiment 4]

[0167] Figure 12Fig. 1 is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 1. In this diagram, mechanical structures for disposing optical components, a case, electrical wiring, and the like are omitted for convenience of explanation.

[0168] The light source device 400 of Embodiment 4 has parts in common with the light source device 200 of Embodiment 2, and the common parts are simplified or omitted from explanation.

[0169] (Configuration of the light source device)

[0170] The light source device 200 of Embodiment 2 is provided with the diffusion plate 115, and the diameter of the blue light beam Bout passing through the diffusion plate 115 is enlarged as it advances, unlike a parallel light beam. That is, the diameter of the blue light beam that is reflected by the reflector 212 and the third dichroic mirror 201c toward the second condenser lens system 109 in front thereof is enlarged.

[0171] In contrast, in this embodiment, the diffusion plate 115 is not used, and the concave lens 110 and the convex lens 111 are provided in front of and behind the reflector 212. By the concave lens 110 and the convex lens 111, the parallel blue light beam Bout having a diameter of Dl is optically adjusted to have a diameter of D2 (D2 > Dl) when it is incident on the second condenser lens system 109. The concave lens 110 and the convex lens 111 can be configured so that the blue light beam Bout becomes a parallel light beam having a diameter of D2 at the point of emission from the convex lens 111. In addition, the concave lens 110 and the convex lens 111 can each be composed of one lens, but one or both of them can be composed of a plurality of lenses depending on the situation.

[0172] According to this embodiment, the same effects as Embodiment 2 are achieved, and since the concave lens 110 and the convex lens 111 are used instead of the diffusion plate 115, the blue light beam Bout incident on the second condenser lens system 109 can be enlarged more or the diameter can be adjusted with high precision.

[0173] [Embodiment 5]

[0174] Figure 13 Fig. 1 is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 1. In this diagram, mechanical structures for disposing optical components, a case, electrical wiring, and the like are omitted for convenience of explanation.

[0175] The light source device 500 of Embodiment 5 has parts in common with the light source device 200 of Embodiment 2, and the common parts are simplified or omitted from explanation.

[0176] (Configuration of the light source device)

[0177] The light source device 200 of Embodiment 2 includes a diffuser plate 115, which causes the diameter of the blue light beam Bout passing through the diffuser plate 115 to expand as it advances, rather than being a parallel beam. That is, the diameter of the blue light beam that is reflected by the reflector 212 and the third dichroic mirror 201c in front of it and then directed toward the second condenser lens system 109 is expanded.

[0178] In contrast, in this embodiment, instead of using a diffuser plate 115, a flat-top device 116 and a convex lens 111 are arranged in front of and behind the reflector 212. Through the flat-top device 116 and the convex lens 111, the parallel blue beam Bout with a diameter of D1 is optically adjusted so that its diameter becomes D2 (where D2 > D1) when incident on the second condenser lens system 109.

[0179] Furthermore, the flat-top device 116 has the function of adjusting the beam profile at the entrance when the blue beam Bout is incident on the optical channel 140. In the case where the diffuser plate 115 is used as in Embodiment 2, such as... Figure 13 As shown in (b), at the entrance of light channel 140, the beam profile of the blue beam Bout is a Gaussian distribution with a long tail. Therefore, a portion of the tail extends beyond the outer edge of the entrance of light channel 140 and cannot enter light channel 140, resulting in blue light loss. If the dot diameter is reduced while maintaining the Gaussian distribution, and the entire tail is intended to enter light channel 140, the intensity at the periphery of the displayed image will decrease, potentially leading to noticeable uneven brightness and color depth within the image.

[0180] In this embodiment, since a flat-top device 116 is used, therefore... Figure 13 As shown in (c), the beam profile of the blue beam Bout at the entrance of the optical channel 140 can be adjusted to a flat-top shape. The flat-top device 116 can be implemented, for example, by a device structure in which microlenses are arranged in a two-dimensional array in the XY plane; however, other device structures are also possible if the beam profile can be adjusted as described above.

[0181] According to this embodiment, the same effect as in Embodiment 2 is achieved. Furthermore, since a flat-top device 116 and a convex lens 111 are used instead of a diffuser plate 115, the blue light beam Bout incident on the second focusing lens system 109 can be amplified more significantly or its diameter can be adjusted with high precision. This results in improved blue light utilization efficiency and suppression of brightness and color unevenness within the displayed image.

[0182] [Implementation Method 6]

[0183] Figure 14This is a diagram showing the outline structure of the optical system of the light source device according to Embodiment 6. For ease of explanation, the mechanical structure, housing, electrical wiring, etc., used to mount the optical components are omitted in this diagram.

[0184] The light source device 600 of Embodiment 6 has parts that are common to the light source device 400 of Embodiment 4. For the common parts, the description is simplified or omitted.

[0185] (Structure of the light source device)

[0186] The light source device 600 of this embodiment has a condenser lens 108 between the fourth dichroic mirror 202a and the dichroic mirror 201d. This is different from the light source device 400 of embodiment 4.

[0187] The focusing lens 108 is configured to have no effect on (do not interfere with) the fluorescence transmitted from the first dichroic mirror 201a or the dichroic mirror 201d to the fourth dichroic mirror 202a, and to have a focusing effect on the fluorescence reflected by the fourth dichroic mirror 202a to the dichroic mirror 201d.

[0188] By using a condenser lens 108 to focus the fluorescence, the diameter of the fluorescence beam incident on the second condenser lens system 109 can be reduced. Figure 6 (The dashed line in (b)). Therefore, it is possible to reduce Figure 6 (b) shows the convergence angle αin (fluorescence) of the fluorescence after being focused by the second focusing lens system 109 onto the color selection wheel 130a, and the expansion angle αout (fluorescence) of the fluorescence emitted from the light channel 140. That is, by reducing the difference between the expansion angle αout (blue) of the blue light emitted from the light channel 140 and the expansion angle αout (fluorescence) of the fluorescence emitted, the brightness and color depth unevenness within the displayed image can be further reduced.

[0189] Furthermore, since the diameter of the fluorescent beam after being focused by the condenser lens 108 is reduced, the dichroic mirror 201d and the second condenser lens system 109 can be miniaturized compared to the light source device 400 of Embodiment 4.

[0190] [Implementation Method 7]

[0191] Figure 15 Figure (a) is a diagram showing the outline structure of the optical system of the light source device according to Embodiment 7. For ease of explanation, the mechanical structure, housing, electrical wiring, etc. used to mount the optical components are omitted in this figure.

[0192] The light source device 700 of Embodiment 7 has parts that are common to the light source device 500 of Embodiment 5. For the common parts, the description is simplified or omitted.

[0193] (Structure of light source device)

[0194] The light source device 700 of the present embodiment, like the light source device 500 of Embodiment 5, is provided with a blue light-emitting laser light source 101B, a collimator lens system 504 composed of a convex lens 502 and a concave lens 503, a first dichroic mirror 201a, a dichroic mirror 201d, a first condenser lens system 105 (first condensing optical system) composed of a convex lens 105A and a convex lens 105B, a second condenser lens system 109 (second condensing optical system), a flattening device 116, a reflecting device 212, a convex lens 111, and a light passage 140.

[0195] As for the blue light-emitting laser light source 101B (first laser light source that outputs light in a first wavelength region), as shown in (b) of FIG. 1, the light source device 700 of the present embodiment uses a laser light source having the same structure as that of Embodiment 5. In this regard, the present embodiment is common to Embodiment 5 in that the blue light emitted by the laser light source 101B is used as excitation light for exciting the phosphor and as blue illumination light for display. Figure 15

[0196] On the other hand, the present embodiment is different from the light source device 500 of Embodiment 5 in that it is provided with a red light-emitting laser light source 101R (second laser light source that outputs light in a second wavelength region) in that the red laser light (R) emitted by the laser light source 101R, rather than the red fluorescent light emitted by the phosphor, is used as red illumination light for display. The red light of high color purity output by the laser light source 101R is not used for exciting the phosphor but is exclusively used for display. Therefore, the optical system of the light source device 700 is configured so as to be able to coaxially emit the blue light emitted by the laser light source 101B, the fluorescent light emitted by the phosphor, and the red light emitted by the laser light source 101R.

[0197] The laser light source 101R is provided with a red semiconductor laser 102R that oscillates at a center wavelength of, for example, around 635 nm. A collimator lens 103 is provided for each red semiconductor laser 102R. In general, the light beam emitted by a semiconductor laser has a spread of a certain angle, and by providing the collimator lens 103, it is possible to suppress the spread of the light beam and emit a substantially parallel light beam from the laser light source 101R. Here, the collimator lens 103 and the package in which the red semiconductor laser 102R is mounted can be integrated or can be separate. When they are separate, a lens array can be independently arranged immediately behind a plurality of red semiconductor lasers 102R to constitute a light source module.

[0198] As shown in (b) of FIG. 1, the light source device 700 of the present embodiment is provided with a red light-emitting laser light source 101R (second laser light source that outputs light in a second wavelength region) and a dichroic mirror 201d that reflects the light in the second wavelength region and transmits the light in the first wavelength region. The dichroic mirror 201d is arranged so as to be able to transmit the blue light emitted by the laser light source 101B and the fluorescent light emitted by the phosphor and to reflect the red light emitted by the laser light source 101R. Figure 15 ​As shown in (c), in the laser source 101R, the red semiconductor laser 102R and the collimating lens 103 are arranged in an array in the YZ plane, emitting a red beam in the positive Z direction. To set the diameter of the output beam to D2 (reference...) Figure 6 (b) of, such as Figure 15 As shown in (c), the red semiconductor laser 102R and the collimating lens 103 are paired in a 2×2 array, but the pairing configuration is not limited to this example and can be changed appropriately.

[0199] Back Figure 15 In embodiment (a), a rotatable fluorescent color wheel 120b is provided at the same position as the rotatable fluorescent color wheel 120a provided in embodiment 5. Additionally, a rotatable light color selection color wheel 130b is provided at the same position as the rotatable light color selection color wheel 130a provided in embodiment 5.

[0200] exist Figure 16 (a) shows a front view of the fluorescent color wheel 120b used in this embodiment. As shown, the fluorescent color wheel 120b and Figure 3 The structure of the fluorescent color wheel 120a in Embodiment 5 shown in (a) is different. In the fluorescent color wheel 120b of this embodiment, a fluorescent region PH coated with a phosphor for G is provided along the circumference, within a range of approximately 9 o'clock to 4 o'clock when viewed in the circumferential direction; a reflective region RL for reflecting the output light of the laser source 101B is provided from 4 o'clock to 6 o'clock; and a non-functional region NF, which is not optically functional, is provided from 6 o'clock to approximately 9 o'clock. By rotating the fluorescent color wheel 120b around the rotation axis C1, blue light focused on the fluorescent color wheel 120b is sequentially irradiated onto the reflective region RL and the fluorescent region PH.

[0201] Here, for ease of explanation, at the focusing position of the first condenser lens system 105, Figure 16 The period from point 1 to point 4 of the fluorescent color wheel 120b shown in (a) that is located at the focusing position of the first condenser lens system 105 is called the G output period; the period from point 4 to point 6 that is located at the focusing position of the first condenser lens system 105 is called the B output period; the period from point 6 to approximately point 9 that is located at the focusing position of the first condenser lens system 105 is called the R output period; and the period from approximately point 9 to point 1 that is located at the focusing position of the first condenser lens system 105 is called the Y output period. The G output period corresponds to the period when the light source device 700 outputs green light, the B output period corresponds to the period when the light source device 700 outputs blue light, the R output period corresponds to the period when the light source device 700 outputs red light, and the Y output period corresponds to the period when the light source device 700 outputs yellow light.

[0202] In the present embodiment, the laser light source 101B is controlled to be lit to output blue light in the G output period, the B output period, the Y output period, and to be turned off in the R output period. The blue light output from the laser light source 101B in the G output period and the Y output period functions as excitation light for exciting the G phosphor, and the blue light output in the B output period functions as blue light (B color light) for image display.

[0203] In addition, the laser light source 101R is controlled to be lit to output red light in the R output period, the Y output period, and to be turned off in the B output period and the G output period. The red light output in the R output period functions as red light (R color light) for image display, and the red light output in the Y output period functions as yellow light (Y color light) for image display, superimposed with green fluorescent light.

[0204] In Figure 16 A front view of the light color selection color wheel 130b is shown in (b) of FIG. 13. The light color selection color wheel 130b of the present embodiment is different in structure from the light color selection color wheel 130a used in Embodiment 5. In the light color selection color wheel 130b of the present embodiment, a G filter is provided in a region corresponding to the G output period, a B diffusion portion is provided in a region corresponding to the B output period, an R diffusion portion is provided in a region corresponding to the R output period, and a Y filter is provided in a region corresponding to the Y output period, respectively. The light color selection color wheel 130b is connected to a motor, and the motor rotates about the rotation axis C2, and the light color selection color wheel 130b is controlled to rotate in synchronization with the fluorescent color wheel 120b.

[0205] Returning to Figure 15 (a) of FIG. 13, in the present embodiment, a dichroic mirror 202b is provided at the same position as where the fourth dichroic mirror 202a is provided in Embodiment 5. In Figure 17 The optical characteristics of the dichroic mirror 202b are shown by a solid line in (b) of FIG. 13. For reference, the blue light (wavelength around 445 nm) of the laser light source 101B and the red light (wavelength around 635 nm) of the laser light source 101R are shown by a broken line in the figure. The dichroic mirror 202b has optical characteristics of transmitting red light (R light) and reflecting green light (G light). The dichroic mirror 202b having such characteristics can be formed, for example, by vapor-depositing a dielectric multilayer film on a transparent glass substrate or the like.

[0206] In the present embodiment, the operation of the blue light output from the laser light source 101B in the B output period is the same as in Embodiment 5. Also, the operation of the blue light output from the laser light source 101B in the G output period and the Y output period to irradiate the phosphor as excitation light is the same as in Embodiment 5. Also, since the dichroic mirror 202b has the optical characteristic of reflecting the green light (G light) emitted from the phosphor, the operation of the green light output from the G phosphor in the G output period and the Y output period is the same as in Embodiment 5.

[0207] Next, the operation of the red laser light output from the laser light source 101R is described. The laser light source 101R is controlled to output the red laser light in the R output period and the Y output period.

[0208] The red laser light output from the laser light source 101R advances in the positive Z direction and is incident on the dichroic mirror 202b, and since the dichroic mirror 202b has the optical characteristic shown in FIG. 2B, the red light is transmitted and advances in the positive Z direction and is incident on the dichroic mirror 201d. Since the dichroic mirror 201d has the optical characteristic shown in (a) of FIG. 2A, the red light is transmitted and is incident on the second condenser lens system 109. The optical elements are configured so that the light flux of the red light incident on the second condenser lens system 109 is coaxial with the light flux of the blue light and the light flux of the green fluorescent light incident on the second condenser lens system 109. Figure 17 Figure 5 The red light incident on the second condenser lens system 109 in the R output period is condensed toward the entrance port of the light passage 140 via the R diffusion portion of the light color selection color wheel 130b. Also, the red light incident on the second condenser lens system 109 in the Y output period is superimposed with the green light incident on the second condenser lens system 109 in the Y output period to become yellow light, and is condensed toward the entrance port of the light passage 140 via the Y filter of the light color selection color wheel 130b.

[0209] In the present embodiment, since the output light of the red laser light source is used as the illumination light for display, in addition to being able to obtain the same effects as in Embodiment 5, it is possible to further improve the color purity of the red light and the in-picture uniformity of the color balance.

[0210] [Embodiment 8]

[0211] [Embodiment 8]

[0212] Figure 18 ​Fig. 8 is a diagram showing an outline configuration of an optical system of a projection display device according to Embodiment 8. For the sake of explanation, mechanical structures for arranging optical components, a case, electrical wiring, and the like are omitted in the figure. The projection display device 1000 is provided with a light source device 200, an illumination lens 150, a prism 171, a prism 172, a light modulating device 160 (light modulating device), a projection lens 180, and a projection screen 190.

[0213] The light source device 200 is the light source device according to Embodiment 2 described above, and emits blue light (B light), green light (G light), red light (R light), and yellow light (Y light) in time with the display rate of an image.

[0214] The illumination lens 150 is a lens that shapes the light output from the light tunnel 140 of the light source device 200 into a light beam suitable for illuminating the light modulating device 160, and is composed of a single lens or a plurality of lenses.

[0215] The prism 171 and the prism 172 collectively constitute a total internal reflection (TIR) prism. The TIR prism causes the illumination light to undergo total internal reflection and be incident on the light modulating device 160 at a predetermined angle, and causes the reflected light modulated by the light modulating device 160 to be transmitted toward the projection lens 180.

[0216] The light modulating device 160 uses, for example, a digital micromirror device (DMD) in which micromirror devices are arranged in an array. The micromirrors corresponding to each display pixel are driven in accordance with the luminance levels of the color components of an image signal, so that their reflection directions are changed by pulse width modulation. However, other types of reflective light modulating devices such as reflective liquid crystal devices can also be used.

[0217] The light modulating device 160 drives the micromirror devices in accordance with the luminance levels of the color components of an image signal in synchronization with the color switching of the illumination light from the light source device 200, so as to reflect the image light toward the prism 171 at a predetermined angle. The image light is transmitted from the prism 171 and the prism 172, guided toward the projection lens 180, and projected as a color image. The projection lens 180 is composed of a single lens or a plurality of lenses, and can also be provided with an auto focus adjustment function and a zoom function.

[0218] The projection screen 190 is used when a rear projection type display device is constituted. Furthermore, although it is often provided also in the case of a front projection type, it is not necessarily required to be provided when a user projects an image on an arbitrary wall surface or the like.

[0219] According to the present embodiment, a projector is configured by using a small light source device that is excellent in in-screen uniformity with high efficiency and color balance, and thus a small projection display device with high light use efficiency and excellent color balance can be provided.

[0220] [Other Embodiments]

[0221] The present application is not limited to the above-described embodiments, and various modifications and combinations can be made within the technical scope of the present application.

[0222] For example, the method of suppressing the fluorescent loss generated at the side surface by making the side surface of the dichroic mirror parallel to the optical axis OX2 of the first condenser lens system as described in Embodiment 1 can be applied to any dichroic mirror.

[0223] Further, in Embodiment 2 and later, the second dichroic mirror 201b and the third dichroic mirror 201c in Embodiment 1 are integrated as a dichroic mirror 201d, but separate dichroic mirrors can be provided as in Embodiment 1.

[0224] Further, the optical devices such as the diffusion plate, the convex lens, the concave lens, and the flattop device used in any of the embodiments can be appropriately changed by being added to other embodiments, used in combination, deleted, changed in arrangement position, and the like.

[0225] Further, the optical devices such as the diffusion plate, the convex lens, the concave lens, and the flattop device can not be used, and the incident angle distribution (convergence angle) of the laser light incident to the entrance of the light passage 140 can be controlled only by the diffusion function of the color wheel.

[0226] Further, in Embodiment 8, the light source device 200 of Embodiment 2 is used to configure a projection display device, but it is needless to say that the light source device of the other embodiments can be used to configure a projection display device.

Claims

1. A light source apparatus, characterized by comprising: Possessing: a first laser light source that outputs light of a first wavelength region; a first dichroic mirror that has a characteristic of transmitting fluorescent light while reflecting light of the first wavelength region, and is disposed on an optical axis of the first laser light source; a first condensing optical system; a fluorescent color wheel that is rotatable, has a fluorescent region that emits the fluorescent light when irradiated with light of the first wavelength region, and has a reflection region that reflects light of the first wavelength region; a second dichroic mirror that has a characteristic of transmitting the fluorescent light while reflecting light of the first wavelength region; a reflection device that has a characteristic of reflecting light of the first wavelength region, and is disposed so that an optical axis of the reflected light of the first wavelength region is parallel to an optical axis of the first condensing optical system; a third dichroic mirror that has a characteristic of transmitting the fluorescent light while reflecting light of the first wavelength region; a second condensing optical system; a fourth dichroic mirror that has a characteristic of reflecting the fluorescent light, and is disposed so that an optical axis of the reflected fluorescent light is coincident with an optical axis of the second condensing optical system; and a light color selection color wheel that is rotatable in synchronization with the fluorescent color wheel, and has a color filter and a diffusion portion, the first dichroic mirror is disposed so that the light of the first wavelength region emitted from the first laser light source is reflected toward a portion of the first condensing optical system, the light of the first wavelength region reflected by the first dichroic mirror is condensed by the portion of the first condensing optical system toward the fluorescent region or the reflection region of the fluorescent color wheel, a portion of the fluorescent light emitted from the fluorescent region is condensed by the portion of the first condensing optical system, and is transmitted from the first dichroic mirror to be incident on the fourth dichroic mirror, another portion of the fluorescent light emitted from the fluorescent region is condensed by a different portion of the first condensing optical system from the portion, and is transmitted from the second dichroic mirror to be incident on the fourth dichroic mirror, the portion and the other portion of the fluorescent light incident on the fourth dichroic mirror are reflected toward the third dichroic mirror, and are transmitted from the third dichroic mirror to be incident on the second condensing optical system, the light of the first wavelength region reflected by the reflection region is condensed by a different portion of the first condensing optical system from the portion, and is reflected by the second dichroic mirror to be incident on the reflection device, the light of the first wavelength region incident on the reflection device is reflected to be incident on the third dichroic mirror, and is reflected by the third dichroic mirror to be incident on the second condensing optical system, the fluorescent light and the light of the first wavelength region incident on the second condensing optical system are condensed by the second condensing optical system toward the light color selection color wheel, the light color selection color wheel filters the fluorescent light by the color filter, and diffuses the light of the first wavelength region by the diffusion portion to output. Possessing:

2. A light source apparatus, characterized by comprising: a first laser light source that outputs light of a first wavelength region; a second laser light source that outputs light of a second wavelength region; ​ a first dichroic mirror having a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region, and disposed on an optical axis of the first laser light source; a first condensing optical system; a rotatable fluorescent color wheel having a fluorescent region that emits fluorescent light when irradiated with light in the first wavelength region, and a reflection region that reflects light in the first wavelength region; a second dichroic mirror having a characteristic of transmitting fluorescent light while reflecting light in the first wavelength region; a reflection device having a characteristic of reflecting light in the first wavelength region, and disposed so that an optical axis of the reflected light in the first wavelength region is parallel to an optical axis of the first condensing optical system; a third dichroic mirror having a characteristic of transmitting light in the second wavelength region and fluorescent light while reflecting light in the first wavelength region; a second condensing optical system; a fourth dichroic mirror having a characteristic of transmitting light in the second wavelength region while reflecting fluorescent light, and disposed so that an optical axis of the reflected fluorescent light is aligned with an optical axis of the second condensing optical system; and a light color selection color wheel rotatable in synchronization with the fluorescent color wheel, and having a color filter and a diffusion portion, the second laser light source is disposed so that an optical axis of the output light in the second wavelength region is aligned with an optical axis of the second condensing optical system, and the light in the second wavelength region output from the second laser light source is transmitted from the fourth dichroic mirror and the third dichroic mirror to be incident on the second condensing optical system, the first dichroic mirror is disposed so that the light in the first wavelength region emitted from the first laser light source is reflected toward a portion of the first condensing optical system, the light in the first wavelength region reflected by the first dichroic mirror is condensed by the portion of the first condensing optical system to the fluorescent region or the reflection region of the fluorescent color wheel, a portion of the fluorescent light emitted from the fluorescent region is condensed by the portion of the first condensing optical system and transmitted from the first dichroic mirror to be incident on the fourth dichroic mirror, another portion of the fluorescent light emitted from the fluorescent region is condensed by a different portion of the first condensing optical system from the portion and transmitted from the second dichroic mirror to be incident on the fourth dichroic mirror, the portion and the other portion of the fluorescent light incident on the fourth dichroic mirror are reflected toward the third dichroic mirror and transmitted from the third dichroic mirror to be incident on the second condensing optical system, the light in the first wavelength region reflected by the reflection region is condensed by a different portion of the first condensing optical system from the portion and reflected by the second dichroic mirror to be incident on the reflection device, the light in the first wavelength region incident on the reflection device is reflected to be incident on the third dichroic mirror and reflected by the third dichroic mirror to be incident on the second condensing optical system, ​ The fluorescent light, the light of the first wavelength region, and the light of the second wavelength region incident to the second condensing optical system are condensed by the second condensing optical system toward the light color selection color wheel, The light color selection color wheel filters the fluorescent light by the color filter, and diffuses the light of the first wavelength region and the light of the second wavelength region by the diffusion section to output.

3. The light source device according to claim 1 or 2, wherein The first dichroic mirror and the second dichroic mirror have a side surface parallel to an optical axis of the first condensing optical system.

4. The light source device according to any one of claims 1 to 3, wherein Between the second dichroic mirror and the reflection means, a diffusion plate that diffuses the light of the first wavelength region is provided.

5. The light source device according to any one of claims 1 to 3, wherein Between the second dichroic mirror and the reflection means, a concave lens is provided, and between the reflection means and the third dichroic mirror, a convex lens is provided.

6. The light source device according to any one of claims 1 to 3, wherein Between the second dichroic mirror and the reflection means, a flat top means is provided, and between the reflection means and the third dichroic mirror, a convex lens is provided.

7. The light source device according to any one of claims 4 to 6, wherein Between the fourth dichroic mirror and the third dichroic mirror, a convex lens is provided.

8. The light source device according to any one of claims 1 to 7, wherein The second dichroic mirror and the third dichroic mirror are provided as one body.

9. The light source device according to any one of claims 1 to 8, wherein Between the first laser light source and the first dichroic mirror, a collimating optical system that reduces a beam diameter of the light of the first wavelength region output from the first laser light source is provided.

10. A projection display device, characterized by comprising: provided are: the light source device according to any one of claims 1 to 9; a light modulation means; and a projection lens.

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