JP2023038813A - Light source device and projection type display - Google Patents

Abstract

To solve the problem in a light source device for outputting fluorescence obtained by irradiating a fluorescent substance with blue light emitted by a semiconductor laser as excitation light and a part of the blue light emitted by the semiconductor laser, in which the device is required not to be excessively increased in size.SOLUTION: A light source device includes: a laser light source outputting light in a predetermined wavelength region; a first dichroic mirror having characteristics of reflecting the light in the predetermined wavelength region and transmitting fluorescence, and arranged on the optical axis of the laser light source; a first condensing optical system; a luminescent wheel including a fluorescence area emitting fluorescence and a reflective area; a second dichroic mirror having characteristics of transmitting the light in the predetermined wavelength region and reflecting the luminescence; a reflective element having characteristics of reflecting the light in the predetermined wavelength region, and arranged so as to overlap the optic axis of the reflected light in the predetermined wavelength with that of the fluorescence reflected by the second dichroic mirror; a second condensing optical system; and a color selection wheel including a color filter and a diffusion part.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light source device and a projection display device provided with the light source device.

Conventionally, as a light source for a projection display device, a phosphor is irradiated with blue light (B light) emitted by a semiconductor laser (laser diode or LD) as excitation light, and a yellow light (Y light) is obtained from the phosphor. , red light (R light), green light (G light), etc., together with part of blue light (B light) emitted by a semiconductor laser.

Patent Document 1 discloses a light source device in which a green-emitting phosphor, a red-emitting phosphor, and a transmission window are provided along the circumference of a wheel, and blue light is emitted to the circumference while rotating the wheel. It is This light source device employs an optical system that emits green and red fluorescent light emitted by the phosphor of the wheel and blue light transmitted through the transmission window of the wheel in the same direction. Specifically, the blue light transmitted through the transmissive window is guided to a dichroic mirror using two reflecting mirrors, and the optical path of the blue light and the optical path of the fluorescent light are combined by the dichroic mirror. In this light source device, since blue light and fluorescence are led to the dichroic mirror through different optical paths, it is necessary to secure a large optical path space, making it difficult to reduce the size of the device. Furthermore, there is a problem that the number of optical parts such as reflecting mirrors increases.

In Patent Document 2, a green light-emitting phosphor, a red light-emitting phosphor, and a mirror surface are provided along the circumference of the wheel, and blue light is emitted from a blue laser light source (LD array) while rotating the wheel. A light source device that irradiates the peripheral portion of the is disclosed. In this light source device, a dichroic mirror and a quarter-wave plate having polarization characteristics in the blue wavelength band are arranged between the blue laser light source (LD array) and the wheel. This device is configured so that the optical path of the blue light reflected by the mirror surface and the optical path of the fluorescent light are the same by utilizing the polarization characteristics of the laser light source. Therefore, compared with the light source device disclosed in Patent Document 1, it is possible to reduce the size.

Patent Literature 3 discloses a light source device that adopts a configuration in which the optical axis of blue light, which also serves as excitation light, travels from a laser light source to a condenser element and the optical axis of a condenser lens are non-coaxial. In this light source device, the blue light, which also serves as excitation light, is reflected by the mirror, passes through the lower half of the condenser lens, and illuminates the wheel. Blue light reflected by the reflective surface of the wheel passes through the upper half of the condenser lens and is guided to the light guide device. Even without using a quarter-wave plate as in Patent Document 2, the device can be made smaller than the light source device in Patent Document 1.

In Patent Document 4, similarly to Patent Document 3, a light source adopting a configuration in which the optical axis of blue light, which also serves as excitation light, travels from a laser light source to a light-collecting element and the optical axis of the light-collecting element is non-coaxial. An apparatus is disclosed. In this light source device, a color separation element having two regions with different reflection characteristics is arranged between the laser light source and the fluorescent wheel. Although the optical system is configured to output blue light and fluorescence in a time-division manner, the optical path of blue light, which also serves as excitation light, and the optical path of fluorescence are almost the same, so the light source device disclosed in Patent Document 1 can be made smaller.

In Patent Document 5, similarly to Patent Document 3, a light source adopting a configuration in which the optical axis of blue light, which also serves as excitation light, travels from a laser light source to a condenser lens and the optical axis of the condenser lens is non-coaxial. An apparatus is disclosed. In this light source device, the blue light transmitted through the mirror 20a and reflected by the reflecting surface of the wheel is transmitted through the mirror 20a again and then reflected by the three mirrors to change its optical path by 270 degrees. are superimposed so as to coincide with the optical axis of fluorescence. Although it is a configuration that does not require the use of a quarter-wave plate as in Patent Document 2, it requires a space for changing the optical path of blue light by 270 degrees using three mirrors. Compared with the device described in 1., the effect of miniaturization is small.

In Patent Document 6, similarly to Patent Document 3, a light source adopting a configuration in which the optical axis of blue light, which also serves as excitation light, travels from a laser light source to a condenser lens and the optical axis of the condenser lens is non-coaxial. An apparatus is disclosed. 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 and the optical axis of the blue light are superimposed on each other. Although it is a configuration that does not require the use of a quarter-wave plate as in Patent Document 2, it requires a space for changing the optical path of fluorescence by 180 degrees using two mirrors, so the device described in Patent Document 4 Compared to , the effect of miniaturization is small.

JP 2010-256457 A JP 2012-108486 A JP 2014-75221 A JP 2019-61237 A WO2019/109449 U.S. Patent Application Publication No. 2015/0267880

As described above, the light source device described in Patent Document 2 can be made smaller than the light source device described in Patent Document 1. Deterioration of balance could occur. The P-polarized blue light emitted from the laser light source passes through the dichroic mirror, is reflected by the fluorescent wheel, and returns to the dichroic mirror. If the polarization conversion is not performed with high precision, there will be some polarization components that cannot be extracted as reflected light from the dichroic mirror, resulting in loss of blue light and deterioration of the white balance of the projected image.

In addition, if there is a component that shifts from circularly polarized light to elliptical polarized light due to disturbance of polarized light in the condensing lens placed in front of the fluorescent wheel, the amount of light reflected as S-polarized light at the dichroic mirror decreases, resulting in white balance. will lead to a decline in In order to suppress the generation of elliptically polarized light, there is a method of using a material with a small thermal expansion coefficient, such as quartz glass, for the condensing lens, but such materials are expensive and thus disadvantageous in terms of cost. In addition, since the types of optical materials with small thermal expansion coefficients are limited, there is also the problem that the range of optical material selection is narrowed and the degree of freedom in optical design is reduced.

In this respect, the light source devices described in Patent Documents 3 to 6 do not use the polarization characteristics of the light source for extraction of blue light, so the problem that may occur in the light source device described in Patent Document 2 is It doesn't happen, but another problem can arise.

Although the light source device described in Patent Document 3 has a simple configuration and is miniaturized, looking at the distribution of the output light in the cross section of the optical path, the fluorescence is distributed symmetrically with respect to the optical axis of the condenser lens. In contrast, the blue light used for display is distributed only on one half of the condensing lens. As a result, the directivity of the light after entering the light guide device (light tunnel) is different, and when the light modulation panel is illuminated, color unevenness occurs within the screen. In addition, at the end of the dichroic mirror located in the vicinity of the optical axis of the condenser lens, a problem may arise that part of the output light is lost or the optical path is disturbed.

In the light source device described in Patent Document 4, the blue light reflected by the fluorescent wheel is separated into two luminous fluxes by the color separation element, and the two luminous fluxes are incident on the condensing element. However, since the two luminous fluxes of blue light are not coaxial with the fluorescent light, it is difficult to equalize the intensity distributions of the two, which causes color unevenness.
Moreover, it has been difficult to easily manufacture the color-separating element in terms of productivity and cost. For example, when manufacturing a color-separating element by laminating a color-separating part and a light-splitting (light-splitting) part adjacent to each other, light loss will occur unless the lamination is performed with extremely high precision. Achieving this accuracy was practically difficult. In addition, in the case of integral formation instead of lamination, it is practically difficult to manufacture two regions, a color separation section and a spectroscopic section, which have different transmission and reflection characteristics at low cost.

In the light source device described in Patent Document 5, the blue light reflected by the reflective surface of the wheel is reflected by three mirrors to change the optical path by 270 degrees so that the optical axis of the blue light coincides with the optical axis of the fluorescent light. Since they are superimposed, the occurrence of color unevenness is suppressed, but since an optical path space using three mirrors is required, miniaturization of the apparatus is not sufficient.

In the light source device described in Patent Document 6, the fluorescent light is reflected by two mirrors, the optical path is changed by 180 degrees, and the optical axis of the fluorescent light and the optical axis of the blue light are superimposed so that they are aligned. However, since an optical path space using two mirrors is required, miniaturization of the device is not sufficient.

Therefore, in a light source device that outputs, as illumination light, fluorescence obtained by irradiating a phosphor with blue light emitted by a semiconductor laser as excitation light and part of the blue light emitted by the semiconductor laser that is not used as excitation light. Therefore, there has been a demand for a light source device that does not excessively increase the size of the device. Along with this, there has been a demand for a light source device that has excellent in-plane uniformity of color balance and high light utilization efficiency without using an expensive condensing lens made of quartz glass or the like. Further, there is a demand for a projector device that includes such a light source device and that can obtain a high-brightness projected image with good white balance.

A first aspect of the present invention comprises a laser light source that outputs light in a predetermined wavelength range, a characteristic that reflects light in the predetermined wavelength range and allows fluorescence to pass through, and is arranged on the optical axis of the laser light source. a first dichroic mirror, a first condensing optical system, a fluorescent region that emits the fluorescence when light in the predetermined wavelength range is irradiated, a reflective region that reflects the light in the predetermined wavelength region, a rotatable fluorescent wheel comprising a second dichroic mirror having properties of transmitting light in the predetermined wavelength range and reflecting the fluorescent light, and reflecting light in the predetermined wavelength range, a reflecting element arranged so that the optical axis of the reflected light in the predetermined wavelength range overlaps with the optical axis of the fluorescence reflected by the second dichroic mirror; a second condensing optical system; a color selection wheel rotatable in synchronism with the wheel and provided with a color filter and a diffusing portion, wherein the first dichroic mirror collects the light in the predetermined wavelength range emitted by the laser light source into the first collection; The light in the predetermined wavelength range reflected by the first dichroic mirror is arranged to reflect toward a portion of the optical optical system, and the light in the predetermined wavelength range is reflected by the portion of the first light collecting optical system. A portion of the fluorescence that is focused on the region or the reflective region and emitted by the fluorescent region is collected by the portion of the first collection optical system, transmitted through the first dichroic mirror, and transmitted through the second dichroic mirror. Another part of the fluorescence emitted by the fluorescent region that has entered the dichroic mirror is collected by a part different from the part of the first light collecting optical system, enters the second dichroic mirror, and The light in the predetermined wavelength range reflected by the reflective area is condensed by a portion different from the portion of the first condensing optical system, enters the second dichroic mirror, and enters the second dichroic mirror. A part of the fluorescence and another part of the fluorescence are reflected in a predetermined direction, and the light in the predetermined wavelength range that has entered the second dichroic mirror is transmitted and enters the reflecting element, and the The fluorescent light is reflected in the predetermined direction by the reflective element, enters the second dichroic mirror, and is transmitted through the second dichroic mirror again. The light in the wavelength range is condensed toward the color selection wheel by the second condensing optical system, and the color selection wheel converts the fluorescent light through the color filter. filtering, diffusing the light in the predetermined wavelength range by the diffusion unit, and outputting;
A light source device characterized by:

A second aspect of the present invention includes a first laser light source for outputting light in a first wavelength band, a second laser light source for outputting light in a second wavelength band, and transmitting the light in the first wavelength band, one optical surface is arranged on the optical axis of the first laser light source, and the other optical surface is arranged on the optical axis of the second laser light source; and a first dichroic mirror having characteristics of transmitting light and fluorescence in the first wavelength band and reflecting light in the second wavelength band, the first dichroic mirror being on the optical axis of the first laser light source A second dichroic mirror arranged in front of the second dichroic mirror has a characteristic of reflecting light in the first wavelength band and transmitting the fluorescence, and is on the optical axis of the first laser light source than the second dichroic mirror a third dichroic mirror disposed in front; a first light collecting optical system; a fluorescent region that emits fluorescence when irradiated with light in the first wavelength band; and a reflector that reflects the light in the first wavelength band. a rotatable phosphor wheel comprising a region; a fourth dichroic mirror having properties of transmitting light in the first wavelength range and light in the second wavelength range and reflecting the fluorescence; The optical axis of the reflected light in the first wavelength band and the optical axis of the reflected light in the second wavelength band are aligned with the second wavelength band. 4 a reflecting element arranged so as to overlap the optical axis of the fluorescence reflected by the dichroic mirror, a second condensing optical system, rotatable in synchronization with the fluorescence wheel, and provided with a color filter and a diffusion part and a color selection wheel, wherein the first dichroic mirror transmits the light in the first wavelength band emitted by the first laser light source toward the second dichroic mirror, and the second dichroic mirror emitted by the second laser light source is provided. It is arranged to reflect light in two wavelength bands toward the second dichroic mirror, and the light in the first wavelength band emitted by the first laser light source is reflected by the first dichroic mirror and the second dichroic mirror. in this order, reflected by the third dichroic mirror toward a portion of the first condensing optical system, and the portion of the first condensing optical system emits the fluorescent region or the reflective region of the luminescent wheel part of the fluorescence emitted by the fluorescent region is collected by the part of the first collection optical system, transmitted through the third dichroic mirror, and incident on the fourth dichroic mirror. , said fluorescent region emitted Another portion of the fluorescence is collected by a portion different from the portion of the first light collection optical system, passes through the second dichroic mirror, enters the fourth dichroic mirror, and enters the fourth dichroic mirror. The part and the other part of the fluorescence incident on the mirror are reflected in a predetermined direction by the fourth dichroic mirror, and the light in the first wavelength band reflected by the reflection area is converted to the first concentration. The light is collected by a part different from the part of the optical optical system, transmitted through the second dichroic mirror and the fourth dichroic mirror in this order, then reflected in the predetermined direction by the reflecting element, and passes through the fourth dichroic mirror. The light in the second wavelength range that is transmitted again and emitted by the second laser light source is reflected in turn by the first dichroic mirror and the second dichroic mirror, and after transmitting through the fourth dichroic mirror, the reflecting element , the fluorescence reflected by the fourth dichroic mirror and reflected by the fourth dichroic mirror, and the light in the first wavelength band and the first Light in two wavelength bands is focused toward the color selection wheel by the second collection optics, and the color selection wheel filters the fluorescent light through the color filter to produce light in the first wavelength band and The light source device is characterized in that the light in the second wavelength band is diffused by the diffuser and output.

A third aspect of the present invention includes a laser light source that outputs light in a first wavelength region and a light in a second wavelength region, a collimating optical system that reduces a beam diameter of the output light of the laser light source, and the first wavelength a second dichroic mirror having characteristics of transmitting light and fluorescence in the second wavelength range and reflecting light in the second wavelength range, the second dichroic mirror being arranged on the optical axis of the laser light source and ahead of the collimating optical system; a third dichroic mirror having a characteristic of reflecting light in a first wavelength band and transmitting the fluorescence, and arranged in front of the second dichroic mirror on the optical axis of the laser light source; a rotatable fluorescent wheel comprising an optical system, a fluorescent region that emits the fluorescent light when irradiated with light in the first wavelength band, and a reflective region that reflects the light in the first wavelength band; A fourth dichroic mirror having characteristics of transmitting light in one wavelength band and light in the second wavelength band and reflecting the fluorescence, and reflecting light in the first wavelength band and light in the second wavelength band. so that the optical axis of the reflected light in the first wavelength band and the optical axis of the reflected light in the second wavelength band overlap with the optical axis of the fluorescence reflected by the fourth dichroic mirror a second condensing optical system; and a color selection wheel rotatable in synchronization with the phosphor wheel and comprising a color filter and a diffuser, wherein the second dichroic mirror The light in the second wavelength region emitted by the laser light source is arranged to be reflected toward the fourth dichroic mirror, and the light in the first wavelength region emitted by the laser light source is reflected by the second dichroic mirror. After passing through, the light is reflected by the third dichroic mirror toward a portion of the first light collecting optical system, and is collected by the portion of the first light collecting optical system to the fluorescent area or the reflective area of the luminescent wheel. a portion of the fluorescence emitted by the fluorescent region is collected by the portion of the first light collecting optical system, transmitted through the third dichroic mirror and incident on the fourth dichroic mirror, and the fluorescence is Another part of the fluorescence emitted by the region is collected by a part different from the part of the first light collecting optical system, transmitted through the second dichroic mirror and incident on the fourth dichroic mirror, The portion of the fluorescence incident on the fourth dichroic mirror and the other portion of the fluorescence are reflected in a predetermined direction by the fourth dichroic mirror and reflected by the reflection area. The light in the first wavelength band is condensed by a portion different from the portion of the first condensing optical system, transmitted through the second dichroic mirror and the fourth dichroic mirror in this order, and then by the reflecting element. After being reflected in the predetermined direction and transmitted through the fourth dichroic mirror again, the light in the second wavelength region emitted by the laser light source is reflected by the second dichroic mirror and transmitted through the fourth dichroic mirror. , the fluorescence reflected by the reflecting element in the predetermined direction, transmitted again through the fourth dichroic mirror, and reflected by the fourth dichroic mirror, and the first wavelength band transmitted through the fourth dichroic mirror again. Light and light in the second wavelength band are collected by the second collection optics toward the color selection wheel, the color selection wheel filters the fluorescence through the color filter, the first wavelength The light source device is characterized in that the light in the second wavelength band and the light in the second wavelength band are diffused by the diffusion section and output.

According to the present invention, the fluorescence obtained by irradiating the phosphor with the blue light emitted by the semiconductor laser as the excitation light and the portion of the blue light emitted by the semiconductor laser that is not used as the excitation light are output as the illumination light. In the light source device, it is possible to prevent the device from becoming excessively large. In addition, it is possible to realize a light source device with excellent in-plane uniformity of color balance and high light utilization efficiency without using an expensive condensing lens made of quartz glass or the like. Furthermore, it is possible to realize a projector device that includes such a light source device and that can obtain a high-brightness projected image with good white balance.

(a) is a diagram showing a schematic configuration of an optical system of the light source device 100 according to Embodiment 1. FIG. (b) A diagram showing the arrangement of a blue semiconductor laser and a collimating lens in the laser light source 101B. (a) It is a figure for demonstrating the advancing path|route of blue light in Embodiment 1. FIG. (b) is a diagram for explaining a travel path of fluorescence emitted by a phosphor in Embodiment 1. FIG. (a) is a front view of a fluorescent wheel 120a used in Embodiment 1; (b) is a front view of the color selection wheel 130a used in the first embodiment; (a) It is a figure which shows the emission spectrum of the light output from the laser light source 101B in Embodiment 1. FIG. (b) It is a figure which shows the light emission characteristic of fluorescent substance. (a) A diagram showing optical characteristics of a first dichroic mirror 201a in Embodiment 1. FIG. (b) is a diagram showing optical characteristics of a second dichroic mirror 202a in Embodiment 1. FIG. (a) It is a figure which shows the range which a ray passes through the inside of the 1st condensing lens system 105 in Embodiment 1. FIG. (b) is a diagram showing a range in which light rays pass through the second condenser lens system 109 in Embodiment 1. FIG. (a) A diagram showing a state in which a blue luminous flux enters a light tunnel 140 via a color selection wheel 130a and propagates in Embodiment 1. FIG. (b) A diagram showing a state in which fluorescence is incident on the light tunnel 140 via the color selection wheel 130a and propagates in the first embodiment. (a) A diagram showing the relationship between the diffusion function provided to the diffusion portion of the color selection wheel 130a and the light utilization rate in the first embodiment. (b) It is a figure which shows intensity distribution of the blue light diffused by the spreading|diffusion part. FIG. 10 is a diagram showing a schematic configuration of an optical system of a light source device 200 according to Embodiment 2; (a) A schematic diagram showing a first dichroic mirror 201a used in the first embodiment. (b) A schematic diagram showing a first dichroic mirror 201b used in Embodiment 2. FIG. (a) It is a figure which shows schematic structure of the optical system of the light source device 300 which concerns on Embodiment 3. FIG. (b) It is a figure for demonstrating the advancing path|route of blue light in Embodiment 3. FIG. (a) It is a figure which shows schematic structure of the optical system of the light source device 400 which concerns on Embodiment 4. FIG. (b) A diagram showing the arrangement of a blue semiconductor laser and a collimating lens in the laser light source 101B. (c) A diagram showing the arrangement of a red semiconductor laser and a collimating lens in the laser light source 101R. (a) is a front view of a fluorescent wheel 120b used in Embodiment 4; (b) A front view of a color selection wheel 130b used in Embodiment 4. FIG. (a) It is a figure which shows the characteristic of the dichroic mirror 401 used by Embodiment 4, and the dichroic mirror 402. FIG. (b) A diagram showing characteristics of a dichroic mirror 403 used in Embodiment 4. FIG. FIG. 10 is a diagram showing characteristics of a dichroic mirror 404 used in Embodiment 4; (a) It is a figure which shows schematic structure of the optical system of the light source device 500 which concerns on Embodiment 5. FIG. (b) is a diagram showing the arrangement of a blue semiconductor laser and a collimating lens, and a arrangement of a red semiconductor laser and a collimating lens in the laser light source 501. FIG. FIG. 10 is a diagram showing a schematic configuration of an optical system of a projection display device 1000 according to Embodiment 6;

A light source device and a projection display device according to embodiments of the present invention will be described with reference to the drawings. It should be noted that the embodiments shown below are merely examples, and for example, details of the configuration can be modified appropriately by those skilled in the art without departing from the scope of the present invention.
In addition, in the drawings referred to in the following description of the embodiments, unless otherwise specified, the elements shown with the same reference numbers have the same functions.

In the following description, for example, the X plus direction indicates the same direction as the X-axis arrow in the illustrated coordinate system, and the X minus direction indicates the X axis in the illustrated coordinate system. The direction indicated by the arrow is 180 degrees opposite. Moreover, when simply describing the X direction, it means the direction parallel to the X axis regardless of whether it is different from the direction indicated by the X axis arrow in the drawing. The same applies to directions other than X.

[Embodiment 1]
FIG. 1A is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 1. FIG. For convenience of explanation, the diagram omits the mechanical mechanism for installing the optical element, the housing, the electrical wiring, and the like.

(Configuration of light source device)
The light source device 100 includes a laser light source 101B, a collimator lens system 104, a first dichroic mirror 201a, a first condenser lens system 105 (first condenser optical system) composed of convex lenses 105A and 105B, A rotatable fluorescent wheel 120a, a second dichroic mirror 202a, a reflective element 211, a second condensing lens system 109 (second condensing optical system), a rotatable color selection wheel 130a, and a light tunnel 140. , provided.

As the laser light source 101B, for example, a blue semiconductor laser 102 that oscillates at a center wavelength of around 455 nm is used. FIG. 4A illustrates an emission spectrum of light output from the laser light source 101B. As the laser light source 101B, it is possible to use a semiconductor laser with a center wavelength other than 455 nm.

A collimating lens 103 is provided for each blue semiconductor laser 102 . In general, a light beam emitted by a semiconductor laser spreads at a predetermined angle, but by providing the collimating lens 103, the spread of the light beam can be suppressed and a substantially parallel light beam can be extracted from the laser light source 101B. become. Incidentally, the collimating lens 103 may be integrated with the package in which the blue semiconductor laser 102 is mounted, or may be separate. In the case of separate units, a lens array may be arranged independently immediately after the plurality of blue semiconductor lasers 102 to form a light source module.

As shown in FIG. 1B, in the laser light source 101B, pairs of a blue semiconductor laser 102 and a collimator lens 103 are arranged in an array in the XY plane, and emit a blue light beam in the Z plus direction. . Although FIG. 1B illustrates a 2×2 array, the method of arranging the pairs is not limited to this example, and the number of pairs arranged vertically and horizontally can be changed as appropriate.

A light flux emitted from the laser light source 101B is adjusted by a collimating lens system 104 (collimating optical system) so that the diameter of the light flux becomes D1. Although the collimating lens system 104 is schematically shown in the drawing, it can be configured by, for example, a combination of a convex lens and a concave lens. As will be described later, the output light from the laser light source 101B is used as excitation light for exciting phosphors and blue light (B) used for display. The luminous flux diameter of the excitation light is appropriately set according to the number of arrays of the blue semiconductor lasers 102 to be used. is designed accordingly.

In FIG. 1(a), the optical axis of the collimator lens system 104 is shown as an optical axis OX1. The optical axis OX1 of the collimating lens system 104 is set so as to be perpendicular to and through the center of the cross section of the entire light beam emitted by the laser light source 101B. If the laser light source 101B can output a substantially parallel light beam with a diameter D1, the collimating lens system 104 is not necessarily required. In that case, the axis perpendicular to the cross section of the entire light beam emitted by the laser light source 101B and passing through the center is defined as the optical axis OX1.

A first dichroic mirror 201a is arranged on the optical axis OX1 so as to be inclined by 45 degrees with respect to the optical axis OX1. FIG. 5A shows the optical characteristics of the first dichroic mirror 201a with a solid line. For reference, blue light (B light) having a wavelength of about 445 nm is indicated by a dotted line in FIG. light), red light (R light), or yellow light (Y light) including these lights, has an optical characteristic of transmitting therethrough. The first dichroic mirror 201a having such characteristics can be formed, for example, by depositing a dielectric multilayer film on a transparent glass substrate or the like.

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. It is The first condenser lens system 105 can condense the output light of the laser light source 101B onto the luminescent wheel 120a. In the example of FIG. 1, the first condenser lens system 105 is composed of two convex lenses 105A and 105B. It may be composed of one or more lenses. Also, the shape and material of the lens can be appropriately selected. That is, it is also possible to use a lens with an aspheric surface, a free-form surface, or the like, instead of the spherical surface. If an inexpensive optical material such as BK7 is used, the light source device can be provided at a low price.

In this embodiment, the optical axis OX1 and the optical axis OX2 of the first condenser lens system 105 are orthogonal to each other. Then, when the output light of the laser light source 101B is reflected by the first dichroic mirror 201a and then directed toward the luminescent wheel 120a, the right halves of the convex lenses 105A and 105B (in the Z direction Each optical element is arranged so as to pass through the area of the plus side half). That is, the blue light reflected by the first dichroic mirror 201a is condensed by a portion of the first condensing lens system 105. FIG.

A fluorescent wheel 120 a is arranged at the condensing position of the first condensing lens system 105 . FIG. 3A shows a front view of the fluorescent wheel 120a. The fluorescent wheel 120a is based on a disk-shaped glass plate or metal plate, and has a fluorescent area PH and a reflective area RL on the surface near the circumference thereof. The fluorescent region PH is coated with a phosphor, and when irradiated with excitation light (output light from the laser light source 101B), it turns red (R color), green (G color), or yellow depending on the type of phosphor. (Y color) fluorescence is emitted. The reflection area RL is an area for reflecting the output light of the laser light source 101B, and is not coated with phosphor. It is desirable that the reflective region RL is mirror-finished so as to reflect the blue laser light with high efficiency.

A metal having a high thermal conductivity is preferably used for the base material of the fluorescent wheel 120a, and the base material may be provided with irregularities or holes in order to improve the air cooling efficiency. The luminescent wheel 120a is connected to a motor, and the motor rotates around the rotation axis C1, so that the blue light condensed on the luminescent wheel 120a sequentially illuminates the reflection area RL and the fluorescence area PH. will do. In the example of FIG. 3(a), the fluorescent region PH is painted separately with the phosphor for G, the phosphor for R, and the phosphor for Y, but it is not necessary to paint separately with the phosphors of these three colors. Instead, it is possible to appropriately change the material and the coating method according to the specifications of the light source device 100 .

FIG. 4(b) exemplifies the emission spectrum of the phosphor. A dotted line 31 indicates the emission spectrum of the G phosphor, a dashed line 32 indicates the emission spectrum of the Y phosphor, and a solid line 33 indicates the emission spectrum of the R phosphor. Each graph also has a peak at the position corresponding to the wavelength of the blue light that is the excitation light, but this is not due to the luminescence of the phosphor. It indicates that it is scattered by the body. Note that FIG. 4B is an example, and the phosphor used in the embodiment is not limited to the material having this emission characteristic.

Returning to FIG. 1A, on the opposite side of the fluorescent wheel 120a with the first condenser lens system 105 interposed therebetween, a second dichroic mirror 202a is arranged at an angle of 45 degrees with respect to the optical axis OX2. . FIG. 5B shows the optical characteristics of the second dichroic mirror 202a with solid lines. For reference, blue light (B light) having a wavelength of about 445 nm is indicated by a dotted line in the drawing, but the second dichroic mirror 202a transmits blue light (B light) and transmits green light (G light). ), red light (R light), or yellow light (Y light) including these light has an optical characteristic of reflecting. That is, the second dichroic mirror 202a has an optical characteristic of transmitting the output light of the laser light source 101B but reflecting the fluorescence emitted by the fluorescence wheel 120a. The second dichroic mirror 202a having such characteristics can be formed, for example, by depositing a dielectric multilayer film on a transparent glass substrate or the like.

Looking along the optical axis OX2 of the first condensing lens system 105, a reflecting element 211 is arranged in parallel with the second dichroic mirror 202a ahead of the second dichroic mirror 202a. The reflecting element 211 is a mirror that reflects blue (B color) light. The reflecting element 211 preferably has a reflectance of 95% or more for blue (B color) light, and can be produced by forming a dielectric multilayer film on a glass substrate or the like, for example. Alternatively, a reflective film may be formed on the mirror substrate using AL vapor deposition or the like. The reflecting element 211 is installed so that the center (optical axis) of the reflected blue light flux overlaps the center (optical axis) of the fluorescence flux reflected by the second dichroic mirror 202a.

The blue (B color) light reflected by the reflecting element 211 passes through the second dichroic mirror 202a again and travels in the Z plus direction. optical system) is provided. The second condenser lens system 109 is arranged such that its optical axis OX3 coincides with the central axis of the blue (B color) light flux and the central axis of the fluorescence light flux. The second condenser lens system 109 is set to a predetermined NA to match the F-number of a projection lens 180 (FIG. 17) of a display device, which will be described later. Concentrate toward the mouth. The second condenser lens system 109 is schematically represented as a single convex lens in the drawing, but in practice it is not limited to a single lens, and may be configured by combining a plurality of lenses.

A color selection wheel 130 a is arranged between the light tunnel 140 and the second condenser lens system 109 . The color selection wheel 130a is connected to a motor, and rotates as the motor rotates about the rotation axis C2. Each motor is controlled so that the color selection wheel 130a and the fluorescence wheel 120a rotate synchronously.
FIG. 3(b) shows a front view of the color selection wheel 130a. The color selection wheel 130a is provided with a filter section and a diffusion section.

The filter section is provided with an optical filter for excluding unnecessary spectral components from fluorescence. An optical filter is provided to remove and enhance the color purity of the red color. Similarly, the G filter section has an optical filter for removing unnecessary spectral components from the fluorescence emitted by the G phosphor region of the fluorescent wheel 120a to increase the color purity of green, and the Y filter section has an optical filter. An optical filter is provided to remove unwanted spectral components from the fluorescence emitted by the Y phosphor area of the phosphor wheel 120a to enhance the color purity of yellow. It should be noted that the filter section does not have the effect of diffusing the transmitted fluorescence.
Further, the B diffusion portion is provided with a diffusion surface for appropriately diffusing the luminous flux of the blue light. The function and effect of the diffusing section will be described in detail later.

(Operation of light source device)
The operation of the light source device 100 having the configuration described above will be described.
(Blue light output operation)
First, blue light (B color light) is output from the laser light source 101B, and the device operation at the timing when the blue light (B color light) irradiates the reflection area RL of the phosphor wheel 120a will be described.
FIG. 2A is a diagram for explaining the travel path of blue light (B-color light) output from the laser light source 101B. FIG. 2A shows that blue light (B-color light) output from the laser light source 101B at the timing of irradiating the reflection area RL of the fluorescent wheel 120a enters the light tunnel 140 as the blue light (B-color light) component used for image display. Indicates the state to be entered. As will be described later with reference to FIG. 2B, the blue light (B-color light) output from the laser light source 101B at the timing of irradiating the fluorescent region PH of the fluorescent wheel 120a is an excitation light that excites the phosphor. Acts as light.

First, in the laser light source 101B, the blue laser beams output from the respective blue semiconductor lasers 102 are collimated substantially parallel by the collimator lens 103 . Since the laser beams travel in parallel with each other at intervals, strictly speaking, they can be said to be a group of spatially discrete laser beams. may be collectively treated as one luminous flux. That is, the laser light source 101B can be regarded as a light source that emits one blue luminous flux.

This blue luminous flux is adjusted to have a luminous flux diameter of D1 by the collimating lens system 104 and travels along the optical axis OX1. The blue luminous flux that has passed through the collimating lens system 104 is incident on the first dichroic mirror 201a, but since the first dichroic mirror 201a has the characteristics shown in FIG. , the optical path is bent 90 degrees toward the first condenser lens system 105 .

Assuming that the blue light flux (B color light) reflected by the first dichroic mirror 201a is Bin, the blue light flux Bin receives the light-condensing action of the first condenser lens system 105 (convex lens 105a, convex lens 105b), and is converted into a fluorescent wheel. The light is focused on the reflective area RL on 120a.

In this embodiment, the optical axis OX2 of the first condenser lens system 105 and the optical axis of the blue light flux Bin are non-coaxial, that is, the optical axes are offset from each other. This is so that the blue light reflected by the reflection area RL of the fluorescent wheel 120a can be extracted without loss as blue light (B-color light) used for image display. The reflection area RL is formed so that the normal to the reflection surface is parallel to the optical axis OX2 of the condenser lens system 105. As shown in FIG. Indicates the range to pass through. As shown in FIGS. 2(a) and 6(a), the blue luminous flux Bin traveling toward the luminescent wheel 120a is located in the right half area of the first condenser lens system 105, i.e. It passes through a region (part of the condenser lens) on the Z plus direction side of the optical axis OX2.

On the other hand, assuming that the blue light flux (B color light) reflected by the reflection area RL of the fluorescent wheel 120a is Bout, the blue light flux Bout travels backward on the same path as the blue light flux Bin and travels in the right half of the first condenser lens system 105. does not pass through the region of As shown in FIGS. 2(a) and 6(a), the blue luminous flux Bout extends from the left half area of the first condenser lens system 105, that is, in the Z-minus direction from the optical axis OX2 of the first condenser lens system 105. side region (a portion different from the portion through which the blue luminous flux Bin passes).
The blue light beam Bout is restored by the first condenser lens system 105 to have a light beam diameter D1, which is the same as that of the blue light beam Bin, and then travels in the X-plus direction and enters the second dichroic mirror 202a. Since the second dichroic mirror 202a has the optical characteristics shown in FIG.

As described above, the reflecting element 211 is a mirror having an optical property of reflecting blue light, is arranged parallel to the second dichroic mirror 202a, and has the center (optical axis) of the reflected blue light beam. , are positioned so as to overlap the center (optical axis) of the fluorescent light beam reflected by the second dichroic mirror 202a.

The blue luminous flux reflected by the reflecting element 211 passes through the second dichroic mirror 202a again and travels in the Z plus direction. It is The second condenser lens system 109 is arranged such that its optical axis OX3 coincides with the center of the blue light flux.

FIG. 6B is a schematic diagram showing a portion where the light flux enters the second condenser lens system 109. As shown in FIG. The luminous flux diameter of the blue luminous flux Bout is D 1 , and the central axis of the luminous flux coincides with the optical axis OX 3 of the second condenser lens system 109 .
The second condenser lens system 109 is set to a predetermined NA so as to match the F-number of a projection lens 180 (FIG. 17) of a display device, which will be described later. The blue luminous flux Bout with the luminous flux diameter D1 is condensed toward the entrance of the light tunnel 140 by the second condensing lens system 109 .

The optical path of the fluorescence emitted by the fluorescence area PH of the fluorescence wheel 120a will be described later, but as shown in FIG. Although coaxial, the diameter of the blue luminous flux Bout is smaller than that of the fluorescent light when the diameter of the luminous flux is compared. This is because the fluorescence emitted by the fluorescence area PH of the fluorescence wheel 120a is Lambertian emission, and the fluorescence is emitted from the fluorescence area PH in a larger angular range than the blue light reflected by the reflection area RL.

In this state, the incident angle distribution (convergence angle) when the blue luminous flux Bout enters the entrance of the light tunnel 140 and the second condensing lens Differences can occur in the incident angle distribution (convergence angle) when the fluorescent light collected by system 109 is incident on the entrance of light tunnel 140 . If there is a difference in the incident angle distribution (convergence angle), there will be a difference in the emission angle distribution (spread) of the blue light and the fluorescence when they are emitted from the exit of the light tunnel 140, and they will be used as illumination light for a projection display device. In some cases, it may cause color unevenness on the display screen.

Therefore, in the present invention, optical means is provided between the fluorescent wheel 120a and the entrance of the light tunnel 140 to diffuse the blue luminous flux Bout but not to diffuse the fluorescence. It reduces the difference in (convergence angle) and suppresses the occurrence of color unevenness. In Embodiment 1, that function is given to the color selection wheel 130 a arranged between the second condenser lens system 109 and the entrance of the light tunnel 140 .

FIG. 7(a) shows a state in which a blue luminous flux enters the light tunnel 140 via the color selection wheel 130a and propagates, and FIG. 7(b) shows a state in which fluorescent light passes through the color selection wheel 130a 140 and propagating. As is clear from these figures, the convergence angle αin (blue) of the blue light condensed by the second condenser lens system 109 toward the color selection wheel 130a is is less than the angle of convergence αin(fluorescence) at which the emitted fluorescence travels toward the color selection wheel 130a. However, as described with reference to FIG. 3B, the color selection wheel 130a of the present embodiment is provided with a diffusing portion that appropriately diffuses the light flux in the portion through which the blue light is transmitted, and the fluorescent light is transmitted through the diffusion portion. A portion that filters out unwanted spectral components is provided with a color filter portion that does not have a diffusing action. Therefore, the blue luminous flux is diffused by the diffusing portion and enters the light tunnel 140 as shown in FIG. Enter tunnel 140 . As a result, compared to the difference between the convergence angle αin(blue) and the convergence angle αin(fluorescence), the spread angle αout(blue) when blue light is emitted from the light tunnel 140 and the spread angle αout( fluorescence) can be reduced.

FIG. 8A shows the relationship between the diffusion function provided to the diffusion portion and the light utilization rate. The intensity distribution of the blue light diffused by the diffuser has a Gaussian distribution as shown in FIG. 8(b). Since the light is not effectively incident on 140 and the light loss increases, the light utilization rate decreases as shown in FIG. 8(a). Therefore, the diffusing function of the diffusing section is appropriately set in consideration of the balance between the effect of suppressing color unevenness in the display screen and securing the light utilization rate of blue light.

(Fluorescence output operation)
Next, the operation when the light source device 100 outputs fluorescence will be described. That is, the operation of the device at the timing when 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 wheel 120a will be described.

FIG. 2B is a diagram for explaining the traveling path of fluorescence output from the fluorescence wheel 120a. The fluorescence emitted in the fluorescence region PH is input to the light tunnel 140 as illumination light used for image display. It shows a state where The fluorescence spectrum differs depending on which of the G phosphor region, the Y phosphor region, and the R phosphor region among the phosphor regions PH emits light. The optical path is common for each color. The behavior of the blue light as excitation light from the laser light source 101B to the fluorescent wheel 120a is the same as that described with reference to FIG. , the description is omitted here. In FIG. 2B, the solid line indicates only the path from the laser light source 101B to the first dichroic mirror 201a for the blue light.

In FIG. 2(b), the optical path of the fluorescence emitted from the fluorescence region PH is schematically indicated by a dotted line. 105 is emitted toward the whole. That is, as indicated by the dotted line in FIG. 6A, the fluorescence passes through almost the entire area of the first condenser lens system 105 . The fluorescence condensed by the first condensing lens system 105 becomes a parallel luminous flux traveling in the X plus direction, but passes through the right side (Z plus direction side) of the optical axis OX2 of the first condensing lens system 105. The light flux enters the first dichroic mirror 201a. As shown in FIG. 5(a), the first dichroic mirror 201a has an optical characteristic of transmitting light of any of green (G), red (R), and yellow (Y) colors. It passes through this and enters the second dichroic mirror 202a. On the other hand, among the fluorescence, the light beam that has passed through the left side (Z minus direction side) of the optical axis OX2 of the first condenser lens system 105 directly enters the second dichroic mirror 202a.

As shown in FIG. 5(b), the second dichroic mirror 202a has an optical property to reflect fluorescent light of any color of green (G), red (R), and yellow (Y). is bent by 90 degrees and travels in the Z-plus direction toward the second condenser lens system 109 .

As shown in FIG. 6B, the fluorescence incident on the second condenser lens system 109 is coaxial (concentric) with the blue luminous flux Bout, but has a larger luminous flux diameter than the blue luminous flux Bout. The second condenser lens system 109 is set to a predetermined NA to match the F-number of the projection lens 180 of the display device as described above, and the fluorescent light is collected toward the entrance of the light tunnel 140. .

FIG. 7(b) shows a state in which fluorescent light enters the light tunnel 140 via the color selection wheel 130a and propagates. The color selection wheel 130a of the present embodiment is provided with a filter portion that excludes unnecessary spectral components but does not have a diffusing action in a portion through which fluorescence is transmitted. Therefore, the fluorescent light enters the light tunnel 140 without being diffused. As described above, in the present embodiment, the difference between the spread angle αout (blue) when blue light is emitted from the light tunnel 140 and the spread angle αout (fluorescence) when fluorescence is emitted from the light tunnel 140 is reduced. In-plane color unevenness when used as illumination light for a projection display device can be suppressed.

According to the present embodiment, the fluorescence obtained by irradiating the phosphor with the blue light emitted by the semiconductor laser as the excitation light and the portion of the blue light emitted by the semiconductor laser that is not used as the excitation light are output as the illumination light. In the light source device, by arranging the optical path of blue light with a small beam diameter (D1) to intersect between the first condenser lens 105 and the second dichroic mirror 202a, the device is prevented from becoming excessively large. can do In addition, since this embodiment does not perform polarization control using a quarter-wave plate or the like, even if an expensive condenser lens made of quartz glass or the like is not used, in-plane uniformity of color balance is excellent, and light utilization is improved. A highly efficient light source device can be realized.

[Embodiment 2]
9 is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 2. FIG. For convenience of explanation, the diagram omits the mechanical mechanism for installing the optical element, the housing, the electrical wiring, and the like.
The second embodiment is a partial modification of the first embodiment, but descriptions of items that are common to the first embodiment will be simplified or omitted.

(Configuration of light source device)
As in the first embodiment, the light source device 200 of the present embodiment includes a laser light source 101B, a collimating lens system 104, and a first condenser lens system 105 (first condenser optical system), a fluorescent wheel 120a, a second dichroic mirror 202a, a reflective element 211, a second condensing lens system 109 (second condensing optical system), a color selection wheel 130a, and a light tunnel 140. ing. Further, the light source device 200 of this embodiment includes a first dichroic mirror 201b at the same position as the first dichroic mirror 201a in the first embodiment. The first dichroic mirror 201b of the second embodiment has the optical characteristics shown in FIG. 5(a) like the first dichroic mirror 201a of the first embodiment. end) is different from that of the first dichroic mirror 201a of the first embodiment.

The difference between the first embodiment and the second embodiment will be described with reference to FIGS. 10(a) and 10(b). 10A is a schematic diagram showing the first dichroic mirror 201a used in the first embodiment, and FIG. 10B is a schematic diagram showing the first dichroic mirror 201b used in the second embodiment.

As shown in FIG. 10(a), the first dichroic mirror 201a used in the first embodiment is a plate-like member having a side surface SA formed substantially perpendicular to the main surface (optical surface). In general, it is difficult to form a uniform optical surface on the side surface of such a plate material similar to the main surface, so the side surface SA is not optically processed. As shown in FIG. 10A, most of the fluorescence incident on the first dichroic mirror 201a from the principal surface (optical surface) on the first condenser lens system 105 side is It can pass through the surface (optical surface) and proceed in the X-plus direction. However, the fluorescence incident on the first dichroic mirror 201a in the vicinity of the optical axis OX2 of the first condenser lens system 105 reaches the side surface SA, which is not optically processed. Fluorescence cannot travel in the X-plus direction through the non-optically processed side SA, resulting in loss that cannot be used as illumination light.

Therefore, in the second embodiment, as shown in FIG. 10B, the shape (orientation) of the side surface SB of the first dichroic mirror 201b is devised to reduce fluorescence reaching the side surface SB, thereby suppressing fluorescence loss. I'm trying That is, the configuration is such that the side surface SB of the first dichroic mirror 201b is parallel to the optical axis OX2 of the first condenser lens system 105. FIG. Specifically, the angle formed by the main surface (optical surface) on the side of the first condenser lens system 105 and the side surface SB is an obtuse angle (for example, 135 degrees), and the main surface (optical surface) on the side of the second dichroic mirror 202a and the side surface The angle formed by SB is assumed to be an acute angle (for example, 45 degrees).

According to the present embodiment, in addition to obtaining the same effects as those of the first embodiment, the loss on the side surface of the first dichroic mirror is suppressed. can be enhanced.

[Embodiment 3]
FIG. 11A is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 3. FIG. For convenience of explanation, the diagram omits the mechanical mechanism for installing the optical element, the housing, the electrical wiring, and the like.
The third embodiment is a partial modification of the first embodiment, but descriptions of matters that are common to the first embodiment will be simplified or omitted.
(Configuration of light source device)

The light source device 300 of the present embodiment, as in the first embodiment, includes a laser light source 101B, a collimator lens system 104, a first dichroic mirror 201a, and a first condenser lens system composed of a convex lens 105A and a convex lens 105B. 105 (first condensing optical system), a fluorescent wheel 120a, a second dichroic mirror 202a, a second condensing lens system 109 (second condensing optical system), a color selection wheel 130a, and a light tunnel 140. It has Further, the light source device 300 of the present embodiment has a reflecting element 211b at the same position as the reflecting element 211 in the first embodiment. The reflective element 211b of the present embodiment has an optical characteristic of reflecting blue light, like the reflective element 211 of the first embodiment. there is

FIG. 11(b) is a diagram for explaining the traveling path of blue light (B-color light) output from the laser light source 101B in the third embodiment, and corresponds to FIG. 2(a) in the description of the first embodiment. . The difference between the first embodiment and the third embodiment will be described with reference to FIGS. 2(a) and 11(b).

In the third embodiment, the blue light output from the laser light source 101B is reflected by the reflective area RL of the phosphor wheel 120a and enters the reflective element 211b. It is the same as the path to incidence.

In Embodiment 1, since the reflecting surface of the reflecting element 211 is a flat surface, as shown in FIGS. The diameter of Bout was equal to the diameter of the blue light flux Bout when passing through the first condenser lens system 105, and was D1.

In the third embodiment, the reflecting surface of the reflecting element 211b is provided with a diffusing function so that the diameter of the blue light flux reflected by the reflecting element 211b expands toward the second condenser lens system 109. ing. That is, the configuration is such that the difference between the diameter of the blue light flux and the diameter of the fluorescence light flux when passing through the second condenser lens system 109 is small. As a result, it is possible to increase the convergence angle αin(blue) of the blue light condensed by the second condensing lens system 109 as compared with the first embodiment shown in FIG. The convergence angle αin (blue) can be brought closer to the convergence angle αin (fluorescence) of fluorescence shown in FIG. 7B.

According to this embodiment, the angular range of blue light incident on the light tunnel 140 can be controlled not only by the diffusing portion of the color selection wheel 130a but also by the synergistic effect with the diffusing function of the reflective element 211b. I can. As a result, there is no need to excessively increase the control setting angle 1/e2 of the color selection wheel 130a shown in FIG. It is possible to
According to this embodiment, in addition to obtaining the same effect as that of the first embodiment, it is possible to further improve the utilization efficiency of blue light and the in-plane uniformity of color balance.

[Embodiment 4]
FIG. 12A is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 4. FIG. For convenience of explanation, the diagram omits the mechanical mechanism for installing the optical element, the housing, the electrical wiring, and the like.
Although the fourth embodiment has common parts and different parts with the first to third embodiments, description of the common parts will be simplified or omitted.
(Configuration of light source device)

A light source device 400 of the present embodiment includes a laser light source 101B, a laser light source 101R, a first dichroic mirror 401, a second dichroic mirror 402, a third dichroic mirror 403, a convex lens 105A and a convex lens 105B. First condenser lens system 105 (first condenser optical system), fluorescent wheel 120b, fourth dichroic mirror 404, reflecting element 405, and second condenser lens system 109 (second condenser optical system) , a color selection wheel 130 b and a light tunnel 140 .

Among these components, the laser light source 101B, the first condenser lens system 105, the second condenser lens system 109, and the light tunnel 140 configured by the convex lens 105A and the convex lens 105B are the same as those in the first to third embodiments. The same one as used in 1 can be used.

This embodiment is common to Embodiments 1 to 3 in that the blue light emitted by the laser light source 101B is used as excitation light for exciting phosphors and as blue illumination light for display. As shown in FIG. 12B, the laser light source 101B has pairs of a blue semiconductor laser 102 and a collimator lens 103 arranged in an array in the XY plane, and emits a blue light beam in the Z plus direction. Although FIG. 1B illustrates a 2×2 array, the method of arranging the pairs is not limited to this example, and the number of pairs arranged vertically and horizontally can be changed as appropriate.

On the other hand, the light source device 400 of the present embodiment includes not only the laser light source 101B that emits blue light (the first laser light source that outputs light in the first wavelength range), but also the laser light source 101R that emits red light (the second laser light source that outputs light in the second wavelength range). and a second laser light source that outputs light. The red light with high color purity output from the laser light source 101R is not used to excite phosphors, but is used exclusively for display. Therefore, the optical system of the light source device 400 is configured to coaxially extract the blue light emitted by the laser light source 101B, the fluorescence emitted by the phosphor, and the red light emitted by the laser light source 101R.
A detailed description will be given below.

The laser light source 101R includes a red semiconductor laser 102R that oscillates at a central wavelength of, for example, around 635 nm. A collimating lens 103 is provided for each red semiconductor laser 102R. In general, a light beam emitted by a semiconductor laser spreads at a predetermined angle, but by providing the collimator lens 103, the spread of the light beam can be suppressed and a substantially parallel light beam can be extracted from the laser light source 101R. become. Incidentally, the collimating lens 103 may be integrated with the package in which the red semiconductor laser 102R is mounted, or may be separate. In the case of separate units, a light source module may be configured by independently arranging a lens array or the like immediately after the plurality of red semiconductor lasers 102R.

As shown in FIG. 12(c), in the laser light source 101R, pairs of a red semiconductor laser 102R and a collimating lens 103 are arranged in an array in the YZ plane, and emit a red light flux in the minus X direction. . Although FIG. 12C illustrates a 2×2 array, the method of arranging pairs is not limited to this example, and the number of pairs arranged vertically and horizontally can be changed as appropriate.

Although not shown, a collimating lens system for collimating the blue light flux and the red light flux may be further provided. The laser light source 101B and the laser light source 101R are configured so that the diameters of the blue and red light beams emitted from them are the same. In FIG. 12A, the optical axis of the blue luminous flux emitted by the laser light source 101B is indicated as the optical axis OX1. The optical axis OX1 is set so as to be perpendicular to and through the center of the cross section of the entire beam emitted by the laser light source 101B.
A first dichroic mirror 401 is arranged at an angle of 45 degrees with respect to the optical axis OX1 on the optical path of the laser light source 101B and the laser light source 101R which are installed so that their optical paths are perpendicular to each other.

FIG. 14A shows the optical characteristics of the first dichroic mirror 401 with solid lines. For reference, blue light (with a wavelength of about 445 nm) from the laser light source 101B and red light (with a wavelength of about 635 nm) from the laser light source 101R are indicated by dotted lines in FIG. , red light (R light) is reflected and blue light (B light) is transmitted. The first dichroic mirror 401 having such characteristics can be formed, for example, by depositing a dielectric multilayer film on a transparent glass substrate or the like.

Returning to FIG. 12( a ), the blue light emitted by the laser light source 101 B travels straight in the Z plus direction and enters the first dichroic mirror 401 , passes through this and enters the second dichroic mirror 402 . The red light emitted by the laser light source 101R travels straight in the negative X direction and is incident on the first dichroic mirror 401. This causes the red light to be reflected, change the traveling direction to the positive Z direction, and coaxially with the blue light to travel to the second dichroic mirror 401. Incident on the dichroic mirror 402 .

Like the first dichroic mirror 401, the second dichroic mirror 402 of this embodiment has the optical characteristics shown in FIG. light) and green light (G light) have an optical property to pass through. Therefore, the blue light that has entered the second dichroic mirror 402 passes through this, travels straight in the Z plus direction, and enters the third dichroic mirror 403 . On the other hand, the red light that has entered the second dichroic mirror 402 is reflected by this, changes its traveling direction to the X plus direction, and enters the fourth dichroic mirror 404 .
(Blue light output operation)

First, the behavior of blue light incident on the third dichroic mirror 403 will be described. The third dichroic mirror 403 of this embodiment has optical characteristics shown in FIG. 14(b). For reference, the blue light (having a wavelength of about 445 nm) from the laser light source 101B is indicated by a dotted line in FIG. It has characteristics. The third dichroic mirror 403 having such characteristics can be formed, for example, by evaporating a dielectric multilayer film on a transparent glass substrate or the like.

The blue light incident on the third dichroic mirror 403 is reflected toward the first condensing lens system 105 (first condensing optical system) composed of the convex lenses 105A and 105B. Also in this embodiment, the first condenser lens system 105 functions in the same manner as in the first to third embodiments. That is, the blue light passes through the right half (half on the plus side in the Z direction) of the first condenser lens system 105 and is condensed toward the fluorescent wheel 120b.

FIG. 13(a) shows a front view of the fluorescent wheel 120b used in this embodiment. As shown, the luminous wheel 120b has a different configuration from the luminous wheel 120a of Embodiments 1 to 3 shown in FIG. 3(a). In the fluorescent wheel 120b of the present embodiment, the fluorescent region PH coated with the G phosphor is in the range from 9 o'clock to 4 o'clock in the circumferential direction, and the fluorescent region PH is in the range from 4 o'clock to 6 o'clock. A reflection area RL for reflecting the output light of the laser light source 101B is provided along the circumference with a non-functional area NF having no optical function in the range from 6 o'clock to approximately 9 o'clock. By rotating the luminescent wheel 120b around the rotation axis C1, the blue light condensed on the luminescent wheel 120b sequentially illuminates the reflective area RL and the fluorescent area PH.

Here, for convenience of explanation, the timing at which the 1 o'clock to 4 o'clock region of the fluorescent wheel 120b shown in FIG. , the timing at which the 4 o'clock to 6 o'clock area is located is the B output timing, the timing at which the 6 o'clock to approximately 9 o'clock area is located is the R output timing, and the timing where the approximately 9 o'clock to 1 o'clock area is located is the Y output timing. shall be called. The G output timing is the timing at which the light source device 400 outputs green light, the B output timing is the timing at which the light source device 400 outputs blue light, the R output timing is the timing at which the light source device 400 outputs red light, and the Y output timing is the light source. corresponds to the timing at which the device 400 outputs yellow light.

In this embodiment, the laser light source 101B is controlled to turn on at the G output timing, the B output timing, and the Y output timing and output blue light, but to turn off at the R output timing. The blue light output from the laser light source 101B at the G output timing and the Y output timing functions as excitation light for exciting the G phosphor, and the blue light output at the B output timing is the blue light used for image display ( B color light).

The blue light output at the B output timing is reflected by the reflection area RL of the phosphor wheel 120b, and as shown in FIG. The light passes through the area on the negative Z direction side of the optical axis OX2 of the optical lens system 105 and enters the second dichroic mirror 402 as a parallel light beam. Since the second dichroic mirror 402 transmits blue light as described above, the blue light is transmitted through the second dichroic mirror 402 and enters the fourth dichroic mirror 404 . The fourth dichroic mirror 404 is arranged at an angle of 45 degrees with respect to the optical axis OX2 of the first condenser lens system 105 .

FIG. 15 shows the optical characteristics of the fourth dichroic mirror 404 with solid lines. For reference, blue light (with a wavelength of about 445 nm) from the laser light source 101B and red light (with a wavelength of about 635 nm) from the laser light source 101R are indicated by dotted lines in FIG. , blue light (B light) and red light (R light) are transmitted, and green light (G light) is reflected. The fourth dichroic mirror 404 having such characteristics can be formed, for example, by depositing a dielectric multilayer film on a transparent glass substrate or the like.

Returning to FIG. 12A, the blue light incident on the fourth dichroic mirror 404 passes through this and enters the reflecting element 405 . The reflective element 405 of the present embodiment has a property of reflecting blue light and red light, and is imparted with a diffusion function like the reflective element 211b used in the third embodiment. Therefore, the blue light is reflected by the reflecting element 405 , passes through the fourth dichroic mirror 404 again while enlarging the beam diameter, and enters the second condenser lens system 109 . As in the third embodiment, the blue light is condensed by the second condensing lens system 109 and enters the color selection wheel.

Also in this embodiment, a color selection wheel is arranged between the light tunnel 140 and the second condenser lens system 109. The configuration is different from that of the color selection wheel 130a used in FIG.
FIG. 13(b) shows a front view of the color selection wheel 130b. The color selection wheel is provided with a filter section and a diffusion section. The color selection wheel 130b is connected to a motor, and the motor rotates about the rotation axis C2, and the color selection wheel 130b is controlled to rotate in synchronization with the fluorescent wheel 120b.

The color selection wheel 130b of this embodiment includes a G filter in the area corresponding to the G output timing, a B diffusion unit in the area corresponding to the B output timing, and an R filter in the area corresponding to the R output timing. A Y filter is provided in each region corresponding to the Y output timing.

The blue light is incident on the B diffusion portion of the color selection wheel 130b at the B output timing, but the angle range of the blue light incident on the light tunnel 140 is appropriately adjusted by the B diffusion portion, as in the third embodiment. .

(Fluorescence output operation)
Next, the behavior of fluorescence emitted from the fluorescence wheel 120b will be described. At the G output timing and the Y output timing, the blue light output from the laser light source 101B is applied as excitation light to the G phosphor of the phosphor wheel 120b, and green fluorescence is emitted over a wide angle from the G phosphor. be.

In FIG. 12A, the optical path of the fluorescence is schematically indicated by a dotted line. Since the fluorescence is Lambertian emission, it is emitted from the fluorescence region PH toward the entire first condenser lens system 105 in a large angular range. do. That is, as indicated by the dotted line in FIG. 6A, the fluorescence passes through almost the entire area of the first condenser lens system 105 . The fluorescence condensed by the first condensing lens system 105 becomes a parallel luminous flux traveling in the X plus direction, but passes through the left side (Z minus direction side) of the optical axis OX2 of the first condensing lens system 105. The light flux enters the second dichroic mirror 402 , and the light flux that has passed through the right side (Z plus direction side) enters the third dichroic mirror 403 . The second dichroic mirror 402 has the optical characteristics shown in FIG. 14(a), and the third dichroic mirror 403 has the optical characteristics shown in FIG. 14(b). Therefore, the green fluorescence is transmitted through this and enters the fourth dichroic mirror 404 .

As shown in FIG. 15, the fourth dichroic mirror 404 has an optical characteristic of reflecting green light, so that the fluorescence is deflected by 90 degrees and directed toward the second condenser lens system 109 in the Z plus direction. proceed to

The green fluorescence incident on the second condenser lens system 109 at the G output timing is condensed toward the entrance of the light tunnel 140 via the G filter of the color selection wheel 130b.
Also, the green fluorescence incident on the second condenser lens system 109 at the Y output timing is condensed toward the entrance of the light tunnel 140 via the Y filter of the color selection wheel 130b. As will be described later, at the Y output timing, the laser light source 101R is controlled to output red light. Therefore, at the Y output timing, the green fluorescent light is superimposed with red light to become yellow light, which enters the second condenser lens system 109, passes through the Y filter, and is directed to the entrance of the light tunnel 140. It can also be said that the light is condensed by

(Red light output operation)
Next, the behavior of the red laser light output from the laser light source 101R will be described. The laser light source 101R is controlled to output red laser light at the R output timing and the Y output timing.

The red laser light output from the laser light source 101R travels in the minus X direction and is incident on the first dichroic mirror 401. Since the first dichroic mirror 401 has the optical characteristics shown in FIG. The light is reflected, bent 90 degrees, and travels in the Z-plus direction. Each optical element is arranged so that the red light flux reflected by the first dichroic mirror 401 is coaxial with and has the same diameter as the blue light flux output from the laser light source 101B and transmitted through the first dichroic mirror 401. It is

The red light traveling in the Z-plus direction is incident on the second dichroic mirror 402. Since the second dichroic mirror 402 has the optical characteristics shown in FIG. is bent and goes in the X plus direction.

The red light traveling in the X-plus direction is incident on the fourth dichroic mirror 404 , and since the fourth dichroic mirror 404 has the optical characteristics shown in FIG.

As already described, the reflective element 405 has the property of reflecting blue light and red light, and is imparted with a diffusion function like the reflective element 211b used in the third embodiment. Therefore, the red light is reflected by the reflecting element 405 , passes through the fourth dichroic mirror 404 again while enlarging the beam diameter, and enters the second condenser lens system 109 . Like the blue light, the red light is collected by the second condensing lens system 109 and enters the color selection wheel.

The red light incident on the second condenser lens system 109 at the R output timing is condensed toward the entrance of the light tunnel 140 via the R diffuser of the color selection wheel 130b. Also, the red light incident on the second condenser lens system 109 at the Y output timing is condensed toward the entrance of the light tunnel 140 via the Y filter of the color selection wheel 130b.

According to this embodiment, the angular range of blue light and red light incident on the light tunnel 140 can be controlled not only by the color selection wheel 130b but also by the synergistic effect with the diffusion function of the reflective element 405. I can. This eliminates the need to excessively increase the control setting angle 1/e2 of the color selection wheel 130b, and makes it possible to achieve a high level of balance between suppressing color unevenness in the screen and ensuring the light utilization efficiency.

In addition, in this embodiment, since the output light of the red laser light source is used as the illumination light for display, the same effect as in the third embodiment can be obtained, and in addition, the color purity of the red light is improved and the color balance of the screen is improved. Internal uniformity can be further enhanced.

[Embodiment 5]
FIG. 16A is a diagram showing a schematic configuration of an optical system of a light source device according to Embodiment 5. FIG. For convenience of explanation, the diagram omits the mechanical mechanism for installing the optical element, the housing, the electrical wiring, and the like.
Although the fifth embodiment has common parts and different parts with the first to third or fourth embodiments, the explanation of the common parts will be simplified or omitted.

(Configuration of light source device)
A light source device 500 of this embodiment includes a laser light source 501, a collimating optical system 504 composed of a convex lens 502 and a concave lens 503, a second dichroic mirror 402, a third dichroic mirror 403, a convex lens 105A and a convex lens 105B. A first condenser lens system 105 (first condenser optical system), a fluorescent wheel 120b, a fourth dichroic mirror 404, a reflecting element 405, and a second condenser lens system 109 (second condenser optical system), a color selection wheel 130b, and a light tunnel 140. FIG.

Embodiment 5 is a modification of Embodiment 4. Instead of laser light source 101B, laser light source 101R, and first dichroic mirror 401 provided in Embodiment 4, laser light source 501 and collimating optical system 504 (convex lens 502, concave lens 503). The same components as used in the fourth embodiment can be used for components other than these.

In the laser light source 501 of this embodiment, as shown in FIG. 16B, a pair of a blue semiconductor laser 102B and a collimating lens 103 and a pair of a red semiconductor laser 102R and a collimating lens 103 are alternately arranged in the XY plane. They are arranged in an array and emit blue and red light beams in the Z plus direction. Incidentally, the collimating lens 103 may be integrated with the package in which the semiconductor laser is mounted, or may be separate. In the case of separate units, the light source module can be configured by independently arranging the lens array immediately after the semiconductor lasers arranged in an array. Although FIG. 16B shows a 4×4 semiconductor laser array having eight blue semiconductor lasers 102B and eight red semiconductor lasers 102R, the configuration of the semiconductor laser array is limited to this example. not a thing

In the fourth embodiment, the laser light source 101B and the laser light source 101R are arranged so that their optical axes are orthogonal to each other, and the light beams output from both laser light sources are directed by the first dichroic mirror 401 so that their optical paths overlap each other. was synthesized to On the other hand, in this embodiment, the first dichroic mirror 401 is used by using the laser light source 501 in which the blue semiconductor laser 102B and the red semiconductor laser 102R are alternately arranged two-dimensionally in the XY plane in a mosaic pattern. The configuration does not require optical path synthesis. In the laser light source 501, the blue semiconductor laser 102B and the red semiconductor laser 102R are configured to be driven independently of each other. Both of the lasers 102R can be turned on simultaneously, and both the blue semiconductor laser 102B and the red semiconductor laser 102R can be turned off as appropriate.

The timing at which the light source device 500 outputs green light is G output timing, the timing at which blue light is output is B output timing, the timing at which red light is output is R output timing, and the timing at which yellow light is output is Y output timing. , the laser light source 501 turns on only the blue semiconductor laser 102B at the B output timing and the G output timing, turns on only the red semiconductor laser 102R at the R output timing, and turns on the blue semiconductor laser 102B at the Y output timing. Both red semiconductor lasers 102R are turned on.

Since the blue semiconductor laser 102B and the red semiconductor laser 102R are two-dimensionally arranged, the light emitting surface of the light source device 500 has a larger area as a whole, and the luminous flux diameter of the output light becomes larger than that of the fourth embodiment. Therefore, in the present embodiment, the collimating optical system 504 is used to convert the light output from the light source device 500 into parallel light with a reduced luminous flux diameter. In FIG. 16, the collimating optical system 504 is schematically illustrated as being composed of one convex lens 502 and one concave lens 503, but the lens configuration of the collimating optical system 504 is limited to this example. Instead, it can be changed as appropriate.
The behavior of the blue laser light and the red laser light after passing through the collimating optical system 504 and the behavior of the fluorescence emitted from the fluorescent wheel are the same as those in the fourth embodiment, so the description will be omitted.

According to this embodiment, the angular range of blue light and red light incident on the light tunnel 140 can be controlled not only by the color selection wheel 130b but also by the synergistic effect with the diffusion function of the reflective element 405. I can. This eliminates the need to excessively increase the control setting angle 1/e2 of the color selection wheel 130b, and makes it possible to achieve a high level of balance between suppressing color unevenness in the screen and ensuring the light utilization efficiency.

Further, in the present embodiment, the color purity of the red light for display can be increased as in the fourth embodiment. In addition, since the red light and the blue light are emitted from the same plane in the same direction, the optical path space (the space occupied by the device) is smaller than that of the fourth embodiment in which the red laser light source and the blue laser light source are arranged so that the optical axes are perpendicular to each other. can be made compact.

[Embodiment 6]
17 is a diagram showing a schematic configuration of an optical system of a projection display device according to Embodiment 6. FIG. For convenience of explanation, the diagram omits the mechanical mechanism for installing the optical element, the housing, the electrical wiring, and the like. The projection display device 1000 includes a light source device 300 , an illumination lens 150 , a prism 171 , a prism 172 , a light modulation device 160 (light modulation element), a projection lens 180 and a projection screen 190 .

The light source device 300 is the light source device according to the third embodiment described above, and emits blue light (B color light), green light (G color light), red light (R color light), and yellow light (Y color light) at an image display rate. are time-divided according to .

The illumination lens 150 is a lens that shapes the light output from the light tunnel 140 of the light source device 300 into a luminous flux suitable for illuminating the light modulation device 160 . Consists of one or more lenses.

The prisms 171 and 172 together form a TIR prism (total internal reflection prism). The TIR prism causes the illumination light to undergo total internal reflection, enter the light modulation device 160 at a predetermined angle, and transmit the reflected light modulated by the light modulation device 160 toward the projection lens 180 .

A DMD having an array of micromirror devices, for example, is used as the light modulation device 160 . A micromirror corresponding to each display pixel is driven so that the reflection direction is changed by pulse width modulation according to the luminance level of the video signal. However, it is also possible to use other types of reflective light modulating devices, such as reflective liquid crystal devices.

The light modulation device 160 drives the micromirror device according to the luminance level of each color component of the video signal in synchronization with the switching of the color of the illumination light from the light source device 300, and directs the video light to the prism 171 in a predetermined manner. reflect at an angle. The image light passes through prisms 171 and 172, is guided to projection lens 180, and is projected as a color image. Projection lens 180 may consist of a single lens or multiple lenses, and may also have autofocus and zoom functions.

The projection screen 190 is used when constructing a rear projection type display device. In addition, although it is often installed in the case of the front projection type, it is not always necessary to install it when the user wants to project onto an arbitrary wall surface or the like.

According to the present embodiment, the projector is configured using a compact light source device that is highly efficient and has excellent in-screen uniformity of color balance. A display device can be provided.

[Other embodiments]
Implementation of the present invention is not limited to the embodiments described above, and many modifications and combinations are possible within the technical concept of the present invention.
For example, as with the first dichroic mirror 201b described in the second embodiment, there is a method of suppressing the loss of fluorescence generated on the side surface by making the side surface of the dichroic mirror parallel to the optical axis OX2 of the first condenser lens system. , can be applied to any dichroic mirror of the other embodiments.

Further, in Embodiments 4 and 5, a flat reflecting element having no diffusion function is used as in Embodiment 1, and the laser light incident on the entrance of the light tunnel 140 is caused only by the diffusion function of the color selection wheel. may control the incident angle distribution (convergence angle) of .

Further, in the sixth embodiment, the light source device 300 of the third embodiment is used to configure the projection display device, but it goes without saying that the light source device of another embodiment may be used to configure the projection display device. .

Also, the emission wavelength (center wavelength) of the semiconductor laser and the emission wavelength of the phosphor may not necessarily be as exemplified in the embodiments. The cutoff wavelength of the dichroic mirror may be appropriately set according to the selected emission wavelength.

100 Light source device/101B, 101R Laser light source/102 Blue semiconductor laser/102R Red semiconductor laser/103 Collimating lens/104 Collimating lens system/105 First condenser lens system/105A, 105B Convex lens/109 Second condenser lens system/120a, 120b Fluorescence wheel/130a, 130b Color selection wheel/140 Light tunnel/150... Illumination lens/160... Light modulation device/171... Prism/172... Prism/180... Projection lens/190... Projection screen/200... Light source device /201a, 201b... First dichroic mirror/202a... Second dichroic mirror/211, 211b... Reflective element/300... Light source device/400... Light source device/401... First Dichroic mirror/402 Second dichroic mirror/403 Third dichroic mirror/404 Fourth dichroic mirror/405 Reflective element/500 Light source device/501 Laser light source /502... Convex lens/503... Concave lens/504... Collimating optical system/1000... Projection type display device/PH... Fluorescence area/RL... Reflection area

Claims (8)

a laser light source that outputs light in a predetermined wavelength range;
a first dichroic mirror having characteristics of reflecting light in the predetermined wavelength range and transmitting fluorescence, and arranged on the optical axis of the laser light source;
a first condensing optical system;
a rotatable fluorescent wheel comprising a fluorescent region that emits fluorescence when irradiated with light in the predetermined wavelength range, and a reflective region that reflects the light in the predetermined wavelength range;
a second dichroic mirror having characteristics of transmitting light in the predetermined wavelength range and reflecting the fluorescence;
It has a property of reflecting light in the predetermined wavelength range, and is arranged so that the optical axis of the reflected light in the predetermined wavelength range overlaps with the optical axis of the fluorescence reflected by the second dichroic mirror. a reflective element;
a second condensing optical system;
a color selection wheel rotatable in synchronization with the fluorescent wheel and comprising a color filter and a diffuser;
The first dichroic mirror is arranged to reflect the light in the predetermined wavelength range emitted by the laser light source toward a part of the first light collecting optical system,
the light in the predetermined wavelength range reflected by the first dichroic mirror is condensed onto the fluorescent region or the reflective region of the fluorescent wheel by the part of the first light collecting optical system;
a portion of the fluorescence emitted by the fluorescent region is collected by the portion of the first collection optical system, transmitted through the first dichroic mirror, and incident on the second dichroic mirror;
Another portion of the fluorescence emitted by the fluorescent region is collected by a portion different from the portion of the first light collecting optical system and enters the second dichroic mirror;
the light in the predetermined wavelength range reflected by the reflection area is condensed by a portion different from the portion of the first condensing optical system and enters the second dichroic mirror;
A part of the fluorescence incident on the second dichroic mirror and another part of the fluorescence are reflected in a predetermined direction,
The light in the predetermined wavelength range incident on the second dichroic mirror is transmitted and incident on the reflective element, reflected by the reflective element in the predetermined direction, incident on the second dichroic mirror, and reflected again. penetrate,
The fluorescence reflected by the second dichroic mirror and the light in the predetermined wavelength range transmitted again through the second dichroic mirror are condensed toward the color selection wheel by the second condensing optical system,
The color selection wheel filters the fluorescence with the color filter, diffuses the light in the predetermined wavelength range with the diffusion unit, and outputs it.
A light source device characterized by: In the light source device according to claim 1,
The first dichroic mirror has a side surface parallel to the optical axis of the first condensing optical system,
A light source device characterized by: The light source device according to claim 1 or 2,
The reflective element has a reflective surface with a diffusion function,
A light source device characterized by: a first laser light source that outputs light in a first wavelength band;
a second laser light source that outputs light in a second wavelength region;
It has characteristics of transmitting light in the first wavelength band and reflecting light in the second wavelength band, one optical surface being arranged on the optical axis of the first laser light source, and the other optical surface being the a first dichroic mirror arranged on the optical axis of the second laser light source;
It has characteristics of transmitting light and fluorescence in the first wavelength range and reflecting light in the second wavelength range, and is disposed forward of the first dichroic mirror on the optical axis of the first laser light source. a second dichroic mirror;
a third dichroic mirror having characteristics of reflecting the light in the first wavelength band and transmitting the fluorescence, and arranged in front of the second dichroic mirror on the optical axis of the first laser light source;
a first condensing optical system;
a rotatable fluorescent wheel comprising a fluorescent region that emits fluorescence when irradiated with light in the first wavelength band and a reflective region that reflects light in the first wavelength band;
a fourth dichroic mirror having characteristics of transmitting the light in the first wavelength range and the light in the second wavelength range and reflecting the fluorescence;
The optical axis of the reflected light in the first wavelength band and the optical axis of the reflected light in the second wavelength band have the property of reflecting the light in the first wavelength band and the light in the second wavelength band. , a reflecting element arranged so as to overlap the optical axis of the fluorescence reflected by the fourth dichroic mirror;
a second condensing optical system;
a color selection wheel rotatable in synchronization with the fluorescent wheel and comprising a color filter and a diffuser;
The first dichroic mirror transmits light in the first wavelength band emitted by the first laser light source toward the second dichroic mirror, and transmits light in the second wavelength band emitted by the second laser light source to the second dichroic mirror. 2 It is arranged to reflect toward the dichroic mirror,
The light in the first wavelength region emitted by the first laser light source passes through the first dichroic mirror and the second dichroic mirror in this order, and then passes through the third dichroic mirror to a part of the first focusing optical system. reflected toward and focused by the portion of the first collection optics onto the fluorescent or reflective area of the fluorescent wheel;
part of the fluorescence emitted by the fluorescent region is collected by the part of the first collection optical system, transmitted through the third dichroic mirror and incident on the fourth dichroic mirror;
Another portion of the fluorescence emitted by the fluorescent region is collected by a portion different from the portion of the first light collecting optical system, transmitted through the second dichroic mirror, and incident on the fourth dichroic mirror. death,
the part and the other part of the fluorescence incident on the fourth dichroic mirror are reflected in a predetermined direction by the fourth dichroic mirror;
The light in the first wavelength band reflected by the reflective region is collected by a portion different from the portion of the first light collecting optical system and transmitted through the second dichroic mirror and the fourth dichroic mirror in this order. After that, it is reflected in the predetermined direction by the reflective element and is transmitted through the fourth dichroic mirror again,
The light in the second wavelength range emitted by the second laser light source is sequentially reflected by the first dichroic mirror and the second dichroic mirror, and after passing through the fourth dichroic mirror, is reflected by the reflecting element in the predetermined direction. reflected by and transmitted through the fourth dichroic mirror again,
The fluorescence reflected by the fourth dichroic mirror, and the light in the first wavelength region and the light in the second wavelength region transmitted again through the fourth dichroic mirror are selected by the second light collection optical system. focused towards the wheel,
The color selection wheel filters the fluorescence with the color filter, diffuses the light in the first wavelength band and the light in the second wavelength band with the diffusion unit, and outputs the light.
A light source device characterized by: a laser light source that outputs light in the first wavelength region and light in the second wavelength region;
a collimating optical system that reduces a beam diameter of output light from the laser light source;
A second dichroic having characteristics of transmitting light in the first wavelength band and fluorescence and reflecting light in the second wavelength band and arranged on the optical axis of the laser light source ahead of the collimating optical system. with a mirror
a third dichroic mirror having characteristics of reflecting the light in the first wavelength band and transmitting the fluorescence, and arranged in front of the second dichroic mirror on the optical axis of the laser light source;
a first condensing optical system;
a rotatable fluorescent wheel comprising a fluorescent region that emits fluorescence when irradiated with light in the first wavelength band and a reflective region that reflects light in the first wavelength band;
a fourth dichroic mirror having characteristics of transmitting the light in the first wavelength range and the light in the second wavelength range and reflecting the fluorescence;
The optical axis of the reflected light in the first wavelength band and the optical axis of the reflected light in the second wavelength band have the property of reflecting the light in the first wavelength band and the light in the second wavelength band. , a reflecting element arranged so as to overlap the optical axis of the fluorescence reflected by the fourth dichroic mirror;
a second condensing optical system;
a color selection wheel rotatable in synchronization with the fluorescent wheel and comprising a color filter and a diffuser;
The second dichroic mirror is arranged to reflect the light in the second wavelength band emitted by the laser light source toward the fourth dichroic mirror,
The light in the first wavelength region emitted by the laser light source is reflected by the third dichroic mirror toward a part of the first light collecting optical system after passing through the second dichroic mirror, and the first light collecting light focused by the portion of the optical system onto the fluorescent area or the reflective area of the fluorescent wheel;
part of the fluorescence emitted by the fluorescent region is collected by the part of the first collection optical system, transmitted through the third dichroic mirror and incident on the fourth dichroic mirror;
Another portion of the fluorescence emitted by the fluorescent region is collected by a portion different from the portion of the first light collecting optical system, transmitted through the second dichroic mirror, and incident on the fourth dichroic mirror. death,
the portion of the fluorescence incident on the fourth dichroic mirror and the other portion of the fluorescence are reflected in a predetermined direction by the fourth dichroic mirror;
The light in the first wavelength band reflected by the reflective region is collected by a portion different from the portion of the first light collecting optical system and transmitted through the second dichroic mirror and the fourth dichroic mirror in this order. After that, it is reflected in the predetermined direction by the reflective element and is transmitted through the fourth dichroic mirror again,
The light in the second wavelength region emitted by the laser light source is reflected by the second dichroic mirror, transmitted through the fourth dichroic mirror, then reflected in the predetermined direction by the reflecting element, and is reflected by the fourth dichroic mirror. is passed through again, and
The fluorescence reflected by the fourth dichroic mirror, and the light in the first wavelength region and the light in the second wavelength region transmitted again through the fourth dichroic mirror are selected by the second light collection optical system. focused towards the wheel,
The color selection wheel filters the fluorescence with the color filter, diffuses the light in the first wavelength band and the light in the second wavelength band with the diffusion unit, and outputs the light.
A light source device characterized by: In the light source device according to claim 4 or 5,
The second dichroic mirror and/or the third dichroic mirror has a side surface parallel to the optical axis of the first light collecting optical system,
A light source device characterized by: The light source device according to any one of claims 4 to 6,
The reflective element has a reflective surface with a diffusion function,
A light source device characterized by: a light source device according to any one of claims 1 to 7;
comprising a light modulation element and a projection lens,
A projection display device characterized by:

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