JP2016109849A - Light source device and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized light source device including a plurality of solid light sources.SOLUTION: A light source device 2 comprises a light source unit 21 including a plurality of solid light sources, a first reflective element 23 which reflects light emitted from the light source unit 21, a second reflective element 24 which is disposed in a light emission direction of a first solid light source out of the plurality of solid light sources and reflects light reflected by the first reflective element 23, a phosphor layer 47 on which light reflected by the second reflective element 24 is made incident, and a light guide optical system 22 which guides light emitted from the first solid light source to the first reflective element 23 while detouring around the second reflective element 24.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a light source device and a projector.

  As a light source used for a projector, a light source device including a solid light source such as a semiconductor laser and a phosphor layer that generates fluorescence when excited by light emitted from the solid light source is known. Patent Document 1 below discloses a light source device including a light collecting unit including a plurality of laser light sources, a collimator lens, a reflecting member having an aspheric reflecting surface, a flat reflecting surface, and a phosphor layer. In the light source device of Patent Document 1, light emitted from a laser light source is substantially collimated by a collimator lens, and then reflected and collected by an aspherical reflecting surface of a reflecting member. The light reflected by the aspherical reflecting surface is further reflected by the planar reflecting surface and condensed on a predetermined region of the phosphor layer.

JP 2014-85623 A

  Patent Document 1 discloses an example of a light source device using two sets of the above-described condensing units in order to increase the luminance of light emitted from a phosphor layer. In this example, the plurality of laser light sources are arranged in a direction in which two light collecting units are arranged. When the two condensing units are viewed from the direction parallel to the traveling direction of the light emitted from the plurality of laser light sources, all the laser light sources are located outside the plane reflecting surface. In this configuration, there is a problem that the size of the light source device in the arrangement direction of the laser light sources is increased.

  One embodiment of the present invention has been made to solve the above-described problems, and an object thereof is to provide a small light source device including a plurality of solid-state light sources. Another object of one embodiment of the present invention is to provide a projector including the light source device described above.

  In order to achieve the above object, a light source device according to one aspect of the present invention includes a light source unit including a plurality of solid-state light sources, a first reflective element that reflects light emitted from the light source unit, A second reflective element that is arranged in the light emission direction of the first solid light source among the plurality of solid light sources and reflects the light reflected by the first reflective element, and reflected by the second reflective element A phosphor layer on which the light is incident, and a light guide optical system that guides the light emitted from the first solid-state light source to the first reflective element while bypassing the second reflective element. It is characterized by providing.

  In the light source device according to one aspect of the present invention, the second reflecting element is disposed in the light emission direction of the first solid light source, and the light emitted from the first solid light source is transmitted by the light guide optical system. The second reflective element is bypassed and guided to the first reflective element. Therefore, the first solid light source among the plurality of solid light sources is light behind the second reflective element (on the side opposite to the reflective surface of the second reflective element) and reflected by the second reflective element. When viewed from a direction parallel to the optical axis, the first solid-state light source and the second reflecting element are arranged at positions overlapping each other. Thereby, size reduction of a light source device can be achieved.

In the light source device according to one aspect of the present invention, the light guide optical system may include a pair of mirrors.
According to this configuration, it is possible to provide a light guide optical system having a simple configuration at low cost.

In the light source device according to one aspect of the present invention, the light guide optical system may include a prism having two reflecting surfaces.
According to this configuration, since the parallelism of the two reflecting surfaces is determined by the processing accuracy at the time of manufacturing the prism, it is possible to provide a light guide optical system that does not depend on the mounting accuracy.

In the light source device according to one aspect of the present invention, it is desirable that an optical axis of light incident on the light guide optical system and an optical axis of light emitted from the light guide optical system are substantially parallel.
According to this configuration, for example, when a homogenizer composed of a pair of lens arrays or the like is inserted into the optical path between the second reflecting element and the phosphor layer, light is reliably incident on each lens of the lens array. Can be made. Thereby, the illumination intensity distribution of a fluorescent substance layer can be made into top hat-shaped distribution.

In the light source device according to one aspect of the present invention, an optical axis of light emitted from the first solid light source and emitted from the light guide optical system is derived from a second solid light source of the plurality of solid light sources. The structure located between the optical axis of the light inject | emitted, and the optical axis of the light inject | emitted from the 3rd solid light source may be sufficient.
According to this configuration, it is possible to narrow the luminous flux width of the plurality of light emitted from the plurality of solid light sources. Thereby, a 1st reflective element can be reduced in size.

A projector according to one aspect of the present invention includes a light source device according to one aspect of the present invention, a light modulation device that forms image light by modulating light emitted from the light source device according to image information, A projection optical system for projecting image light.
The projector according to one aspect of the present invention includes the light source device according to one aspect of the present invention, whereby a small projector can be realized.

It is a schematic block diagram which shows the projector of 1st Embodiment. It is a schematic block diagram which shows the light source device of 1st Embodiment. It is a schematic block diagram which shows the light source device of 2nd Embodiment.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
The projector according to the present embodiment is an example of a projector using three transmissive liquid crystal light valves.
FIG. 1 is a schematic configuration diagram illustrating a projector according to the present embodiment. FIG. 2 is a schematic configuration diagram illustrating the light source device of the present embodiment.
In the following drawings, in order to make each component easy to see, the scale of the size may be varied depending on the component.

  As shown in FIG. 1, the projector 1 of this embodiment is a projection type image display device that displays a color image on a screen SCR. The projector 1 includes three light modulation devices corresponding to the respective color lights of red light LR, green light LG, and blue light LB. The projector 1 includes a semiconductor laser that can obtain light with high luminance and high output as a solid light source of the light source device 2. The projector 1 includes a light source device 2, a uniform illumination optical system 40, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a synthesis optical system 5, and a projection optical system 6. Is roughly provided.

  The light source device 2 emits white illumination light WL toward the uniform illumination optical system 40. As the light source device 2, the light source device according to the first embodiment of the present invention to be described later is used.

  The uniform illumination optical system 40 includes an integrator optical system 31, a polarization conversion element 32, and a superimposing optical system 33. The integrator optical system 31 includes a first multi-lens array 31a and a second multi-lens array 31b. The uniform illumination optical system 40 uniformizes the intensity distribution of the illumination light WL emitted from the light source device 2 in the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, which are illumination areas. The illumination light WL emitted from the uniform illumination optical system 40 enters the color separation optical system 3.

  The color separation optical system 3 separates the illumination light WL emitted from the light source device 2 into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a, a second dichroic mirror 7b, a first reflection mirror 8a, a second reflection mirror 8b, a third reflection mirror 8c, and a first A relay lens 9a and a second relay lens 9b are provided.

  The first dichroic mirror 7a has a function of separating the illumination light WL emitted from the light source device 2 into red light LR and light including green light LG and blue light LB. The first dichroic mirror 7a transmits the red light LR and reflects the green light LG and the blue light LB. The second dichroic mirror 7b has a function of separating light reflected by the first dichroic mirror 7a into green light LG and blue light LB. The second dichroic mirror 7b reflects the green light LG and transmits the blue light LB.

  The first reflection mirror 8a is disposed in the optical path of the red light LR. The first reflection mirror 8a reflects the red light LR that has passed through the first dichroic mirror 7a toward the light modulation device 4R for red light. The second reflection mirror 8b and the third reflection mirror 8c are arranged in the optical path of the blue light LB. The second reflection mirror 8b and the third reflection mirror 8c guide the blue light LB transmitted through the second dichroic mirror 7b to the blue light modulation device 4B. The green light LG is reflected by the second dichroic mirror 7b and travels toward the green light modulation device 4G.

  The first relay lens 9a and the second relay lens 9b are disposed on the light emission side of the second dichroic mirror 7b in the optical path of the blue light LB. The first relay lens 9a and the second relay lens 9b compensate for the optical loss of the blue light LB caused by the optical path length of the blue light LB being longer than the optical path lengths of the red light LR and the green light LG. It has a function.

  The light modulator for red light 4R modulates the red light LR according to image information to form image light corresponding to the red light LR. The green light modulation device 4G modulates the green light LG according to image information to form image light corresponding to the green light LG. The blue light light modulation device 4B modulates the blue light LB according to the image information to form image light corresponding to the blue light LB.

  For example, a transmissive liquid crystal panel is used for the light modulator for red light 4R, the light modulator for green light 4G, and the light modulator for blue light 4B. Further, polarizing plates (not shown) are arranged on the incident side and the emission side of the liquid crystal panel, respectively. The polarizing plate transmits linearly polarized light having a specific polarization direction.

  A field lens 10R is disposed on the incident side of the red light light modulation device 4R. A field lens 10G is disposed on the incident side of the green light modulator 4G. A field lens 10B is disposed on the incident side of the blue light modulator 4B. The field lens 10R collimates the red light LR incident on the red light light modulation device 4R. The field lens 10G collimates the green light LG incident on the green light modulator 4G. The field lens 10B collimates the blue light LB incident on the blue light modulator 4B.

  The combining optical system 5 combines the image light corresponding to each of the red light LR, the green light LG, and the blue light LB, and emits the combined image light toward the projection optical system 6. For example, a cross dichroic prism is used for the combining optical system 5.

  The projection optical system 6 includes a projection lens group including a plurality of projection lenses. The projection optical system 6 enlarges and projects the image light combined by the combining optical system 5 toward the screen SCR. As a result, an enlarged color image is displayed on the screen SCR.

Hereinafter, the light source device 2 will be described.
As shown in FIG. 2, the light source device 2 includes a light source unit 21 having a plurality of semiconductor lasers, a light guide optical system 22, a first reflective element 23, a second reflective element 24, and a homogenizer optical system. 25, a retardation plate 26a, a polarizing beam splitter 27, a first pickup optical system 28, a phosphor wheel 29 including a phosphor layer, a retardation plate 26b, and a second pickup optical system 41. , And a rotary diffusion element 42. Hereinafter, the polarization beam splitter is abbreviated as PBS (Polarized Beam Splitter).

  Among the above-described constituent elements, the light source unit 21, the light guide optical system 22, the first reflective element 23, the second reflective element 24, the homogenizer optical system 25, the phase difference plate 26a, the PBS 27, The second pickup optical system 41 is arranged on the optical axis AX0 in a state where the respective optical centers coincide with the optical axis AX0 shown in FIG. The first pickup optical system 28 is disposed on the optical axis AX1 that passes through the center of the PBS 27 and is orthogonal to the optical axis AX0. Although not shown, the first reflective element 23 is configured by a single reflective element having an opening into which the homogenizer optical system 25 can be inserted when viewed from a direction parallel to the optical axis AX0, for example. The configuration of the first reflective element 23 is not limited to this.

The light source unit 21 includes a plurality of semiconductor lasers 43 as solid light sources. The plurality of semiconductor lasers 43 are mounted on one surface of the substrate 44 at a constant interval. The semiconductor laser 43 emits blue excitation light, for example. The plurality of semiconductor lasers 43 are arranged in an array in a plane orthogonal to the optical axis AX0. Although eight semiconductor lasers 43 are illustrated in FIG. 2, the number and arrangement of the plurality of semiconductor lasers 43 are not particularly limited. Of the eight semiconductor lasers 43, the two semiconductor lasers 43 at the center (fourth and fifth semiconductor lasers 43 from the left in FIG. 2) When viewed from the opposite side and in a direction parallel to the optical axis of the light reflected by the second reflective element 24 (a direction parallel to the optical axis AX0), it is disposed at a position overlapping the second reflective element 24. Yes. A collimator lens that converts the excitation light BL into a parallel light beam may be provided on the light emission side of each semiconductor laser 43.
The semiconductor laser 43 of this embodiment corresponds to the solid light source in the claims.

The light source unit 21, the light guide optical system 22, the first reflecting element 23, and the second reflecting element 24 have a bilaterally symmetric configuration with the optical axis AX0 as the center. Therefore, in FIG. 2, the configuration of the left side portion with the optical axis AX0 as the center will be described below.
For convenience of explanation, the four semiconductor lasers 43 on the left side of FIG. 2 are arranged in order from the semiconductor laser 43 at the most central side of the light source unit 21 toward the semiconductor laser 43 at the left end. These are referred to as laser 43B, third semiconductor laser 43C, and fourth semiconductor laser 43D.

  The light guide optical system 22 includes a plurality of mirrors 45. The plurality of mirrors 45 include a pair of mirrors 45A and 45B. The two mirrors in pairs exhibit a function of changing the optical path of light emitted from the specific semiconductor laser 43. Similar to the semiconductor laser 43, the four mirrors 45 on the left side in FIG. 2 are sequentially arranged from the most central mirror 45 to the leftmost mirror 45 in the light source unit in order from the first mirror 45A, the second mirror 45B, These are referred to as a third mirror 45C and a fourth mirror 45D.

  The first mirror 45A and the second mirror 45B change the optical path of the light BL emitted from the first semiconductor laser 43A as a pair of mirrors. The first mirror 45A is arranged on the light emission side of the first semiconductor laser 43A so as to make an angle of 45 ° with the optical axis of the first semiconductor laser 43A. The second mirror 45B is arranged so as to make an angle of 45 ° with the optical axis of the light reflected by the first mirror 45A. The second mirror 45B is provided between the optical path of the emitted light from the second semiconductor laser 43B and the optical path of the emitted light from the third semiconductor laser 43C. Therefore, the second mirror 45B does not interfere with the optical path of the emitted light from the second semiconductor laser 43B and the optical path of the emitted light from the third semiconductor laser 43C.

  As a result, the light BL emitted from the first semiconductor laser 43A is reflected by the first mirror 45A, and the optical path of the light is bent 90 ° counterclockwise. Next, the light BL reflected by the first mirror 45A is reflected by the second mirror 45B, and the optical path of the light is bent 90 ° clockwise. Thus, after the light guide optical system 22 is emitted, the optical path of the light BL emitted from the first semiconductor laser 43A and the third semiconductor laser are emitted from the second semiconductor laser 43B. It is arrange | positioned between the optical paths of the emitted light from 43C.

  The third mirror 45C and the fourth mirror 45D change the optical path of the light BL emitted from the fourth semiconductor laser 43D as a pair of mirrors. The fourth mirror 45D is disposed on the light emission side of the fourth semiconductor laser 43D so as to form an angle of 45 ° with the optical axis of the fourth semiconductor laser 43D. The third mirror 45C is disposed so as to form 45 ° with the optical axis of the light reflected by the fourth mirror 45D. The third mirror 45C is provided between the optical path of the emitted light from the third semiconductor laser 43C and the optical path of the emitted light from the fourth semiconductor laser 43D. Therefore, the third mirror 45C does not interfere with the optical path of the emitted light from the third semiconductor laser 43C and the optical path of the emitted light from the fourth semiconductor laser 43D. The optical axis of light incident on the light guide optical system 22 and the optical axis of light emitted from the light guide optical system 22 are substantially parallel.

  Thereby, the light BL emitted from the fourth semiconductor laser 43D is reflected by the fourth mirror 45D, and the optical path of the light is bent 90 ° clockwise. Next, the light reflected by the fourth mirror 45D is reflected by the third mirror 45C, and the optical path of the light is bent 90 ° counterclockwise. In this way, the optical path of the light emitted from the fourth semiconductor laser 43D is close to the optical path of the light emitted from the third semiconductor laser 43C after the light guide optical system 22 is emitted.

  The plurality of lights BL emitted from the plurality of semiconductor lasers 43 are emitted from the light guide optical system 22 in parallel with each other and in parallel with the optical axis AX0. Due to the action of the light guide optical system 22, the optical path of the light emitted from the first semiconductor laser 43A is the optical path of the emitted light from the second semiconductor laser 43B and the optical path of the emitted light from the third semiconductor laser 43C. The whole of the four lights immediately after being emitted from the light source unit 21 by the optical path of the light emitted from the fourth semiconductor laser 43D being close to the optical path of the light emitted from the third semiconductor laser 43C. The light beam width after exiting the light guide optical system 22 is narrowed to W2. As described above, the light guide optical system 22 guides the light emitted from the first semiconductor laser 43 </ b> A to the first reflective element 23, bypassing the second reflective element 24.

  The first reflecting element 23 is constituted by a parabolic mirror, for example. The first reflecting element 23 reflects the light emitted from the light source unit 21. After being emitted from the light source unit 21, the plurality of lights BL transmitted through the light guide optical system 22 are reflected by the first reflecting element 23 and are incident on the second reflecting element 24 in a condensed state.

  The second reflecting element 24 is composed of an aspherical mirror, for example. The second reflecting element 24 is disposed in the light emitting direction of the first semiconductor laser 43 </ b> A among the plurality of semiconductor lasers 43, and reflects the light reflected by the first reflecting element 23. Thereby, the light emitted from the first reflecting element 23 is reflected by the second reflecting element 24 and enters the homogenizer optical system 25 in a state parallel to each other.

  The homogenizer optical system 25 converts the intensity distribution of the light emitted from the second reflecting element 24 into a uniform state distribution, a so-called top hat distribution. The homogenizer optical system 25 includes, for example, a first multi-lens array 25a and a second multi-lens array 25b.

  The phase difference plate 26a is constituted by, for example, a rotatable half-wave plate. Since the light emitted from the semiconductor laser 43 is linearly polarized light, by appropriately setting the rotation angle of the half-wave plate, the light transmitted through the phase difference plate 26a is converted into an S-polarized component and a P-polarized component for the PBS 27. In a predetermined ratio. By rotating the phase difference plate 26a, the ratio of the S-polarized component and the P-polarized component can be changed.

  The PBS 27 is disposed at an angle of 45 ° with respect to the optical axis AX0 and the optical axis AX1. The PBS 27 has a polarization separation function for separating incident light into an S-polarized component and a P-polarized component with respect to the PBS 27. Specifically, the PBS 27 reflects the S-polarized component of the incident light and transmits the P-polarized component of the incident light. The S-polarized component is reflected by the PBS 27 and travels toward the phosphor wheel 29. The P-polarized light component passes through the PBS 27 and travels toward the rotary diffusing element 42.

  The S-polarized light emitted from the PBS 27 enters the first pickup optical system 28. The first pickup optical system 28 collects the incident light BLs toward the phosphor layer 47 on the phosphor wheel 29. The first pickup optical system 28 includes, for example, a first pickup lens 28a and a second pickup lens 28b.

  The light emitted from the first pickup optical system 28 enters the phosphor wheel 29. The phosphor wheel 29 is a so-called reflection-type rotating fluorescent plate, and is provided between the phosphor layer 47 that emits fluorescent light, the rotating plate 49 that supports the phosphor layer 47, and the phosphor layer 47 and the rotating plate 49. A reflection film (not shown) for reflecting the fluorescent light, and a drive motor 50 for driving the rotating plate 49. As the rotating plate 49, for example, a disc is used, but the shape of the rotating plate 49 is not limited to a disc, and may be a flat plate. The drive motor 50 is electrically connected to a control unit (not shown), and the rotation of the rotating plate 49 is controlled by the control unit.

  The phosphor layer 47 includes phosphor particles that emit fluorescence, absorbs excitation light BLs (blue light), converts it into yellow fluorescence, and emits it. The phosphor particles are particulate fluorescent materials that absorb the excitation light BLs and emit fluorescence. For example, the phosphor particles include a substance that emits fluorescence when excited by blue light having a wavelength of about 450 nm, and the excitation light BLs is converted into yellow fluorescence and emitted. As the phosphor particles, for example, YAG (yttrium / aluminum / garnet) phosphors can be used. In addition, the material for forming the phosphor particles may be one kind, or a mixture of particles formed using two or more kinds of materials may be used as the phosphor particles.

  On the other hand, the P-polarized light BLp emitted from the PBS 27 enters the phase difference plate 26b. The phase difference plate 26b is composed of a quarter wavelength plate. The light BLp is converted into circularly polarized light by passing through the phase difference plate 26b. The light BLp that has passed through the phase difference plate 26 b is incident on the second pickup optical system 41. The second pickup optical system 41 condenses incident light toward the rotary diffusing element 42. The second pickup optical system 41 includes, for example, a first pickup lens 41a and a second pickup lens 41b.

  The rotary diffusion element 42 includes a diffuse reflection plate 52 and a drive motor 53 for rotating the diffusion reflection plate 52. The diffuse reflector 52 diffusely reflects the circularly polarized light BLp emitted from the second pickup optical system 41 toward the PBS 27. It is preferable that the diffuse reflection plate 52 causes Lambertian reflection of the light BLp incident on the diffuse reflection plate 52. The rotation axis of the drive motor 53 is disposed substantially parallel to the optical axis AX0. Thereby, the diffuse reflection plate 52 can be rotated in a plane intersecting the optical axis of the light incident on the diffuse reflection plate 52. The diffuse reflection plate 52 is formed, for example, in a circular shape when viewed from the direction of the rotation axis, but the shape of the diffuse reflection plate 52 is not limited to a circular plate, and may be a flat plate.

  The circularly polarized light BLp reflected by the diffusive reflecting plate 52 and transmitted again through the second pickup optical system 41 is transmitted again through the phase difference plate 26b to become S-polarized light BLp.

  The yellow fluorescent light emitted from the phosphor layer 47 of the phosphor wheel 29 and the light BLp (blue light) emitted from the rotating diffusion plate 42 are combined by the PBS 27 to become white illumination light WL. The illumination light WL is incident on the uniform illumination optical system 40 shown in FIG.

  In the light source device 2 of the present embodiment, the second reflecting element 24 is the first semiconductor laser 43 </ b> A among the plurality of semiconductor lasers 43 of the light source unit 21, i.e., the semiconductor laser 43 located in the central region of the light source unit 21. It is arranged in the light emission direction. In other words, when the reflective surface of the second reflective element 24 is viewed from a direction parallel to the optical axis of the light reflected by the second reflective element 24, the first semiconductor laser 43A is the second reflective element 24. It is arrange | positioned in the position which overlaps with the 2nd reflective element 24 behind.

  The light emitted from the first semiconductor laser 43 </ b> A is guided to the first reflecting element 23 by bypassing the second reflecting element 24 by the light guide optical system 22. Therefore, even if the second reflective element 24 is arranged in the light emission direction of the first semiconductor laser 43A, there is a problem such that the emitted light from the first semiconductor laser 43A interferes with the second reflective element 24. It does not occur. In this way, according to the present embodiment, the light source unit 21 can be reduced in size, and as a result, the light source device 2 can be reduced in size. Furthermore, the projector 1 can be downsized.

  In the case of this embodiment, since the light guide optical system 22 is composed of a plurality of mirrors 45, a light guide optical system with a simple configuration can be realized at low cost. In addition, since the optical axis of the light incident on the light guide optical system 22 and the optical axis of the light emitted from the light guide optical system 22 are substantially parallel to each other, each of the corresponding lenses of the lens array of the homogenizer optical system 25 is surely connected. Light can be incident on the. Thereby, the illuminance distribution on the phosphor layer 47 can be surely made into a top hat shape. Further, the optical path of the light emitted from the first semiconductor laser 43A is bent by the light guide optical system 22, and the optical axis of the light emitted from the second semiconductor laser 43B and the optical axis of the light emitted from the third semiconductor laser 43C. It is arranged between. With this configuration, it is possible to narrow the beam width of the plurality of light beams emitted from the plurality of semiconductor lasers 43. As a result, the size of the first reflective element 23 can be reduced.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to FIG.
The basic configuration of the light source device of this embodiment is the same as that of the first embodiment, and the configuration of the light guide optical system is different from that of the first embodiment.
FIG. 3 is a schematic configuration diagram showing the light source device of the present embodiment.
In FIG. 3, the same components as those in FIG. 2 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the light source device of the first embodiment, the light guide optical system is composed of a plurality of mirrors. On the other hand, as shown in FIG. 3, in the light source device 62 of the present embodiment, the light guide optical system 63 includes a prism having two reflecting surfaces parallel to each other. Other configurations of the light source device and the configuration of the projector are the same as those in the first embodiment.

  The first prism 64 changes the optical path of the light emitted from the first semiconductor laser 43A. The first prism 64 has a first reflecting surface 64a and a second reflecting surface 64b. The first reflecting surface 64a is disposed on the light emitting side of the first semiconductor laser 43A so as to form 45 ° with the optical axis of the first semiconductor laser 43A. The second reflecting surface 64b is disposed so as to form 45 ° with the optical axis of the light reflected by the first reflecting surface 64a. The second reflecting surface 64b is provided between the optical path of the emitted light from the second semiconductor laser 43B and the optical path of the emitted light from the third semiconductor laser 43C. The light emitted from the second semiconductor laser 43B travels straight between the first reflecting surface 64a and the second reflecting surface 64b.

  Thereby, the light emitted from the first semiconductor laser 43A is reflected by the first reflecting surface 64a of the first prism 64, and the optical path of the light is bent 90 ° counterclockwise. Next, the light reflected by the first reflecting surface 64a travels through the first prism 64 and then is reflected by the second reflecting surface 64b, and the optical path of the light is bent 90 ° clockwise. Thus, after the light guide optical system 63 is emitted, the optical path of the light emitted from the first semiconductor laser 43A and the third semiconductor laser 43C are emitted from the second semiconductor laser 43B. It is arrange | positioned between the optical paths of the emitted light from.

  The second prism 65 changes the optical path of the light emitted from the fourth semiconductor laser 43D. The first reflecting surface 65a is arranged on the light emission side of the fourth semiconductor laser 43D so as to form an angle of 45 ° with the optical axis of the fourth semiconductor laser 43D. The second reflecting surface 65b is arranged so as to form 45 ° with the optical axis of the light reflected by the first reflecting surface 65a. The second reflecting surface 65b is disposed between the optical path of the emitted light from the third semiconductor laser 43C and the optical path of the emitted light from the fourth semiconductor laser 43D.

  Thereby, the light emitted from the fourth semiconductor laser 43D is reflected by the first reflecting surface 65a of the second prism 65, and the optical path of the light is bent 90 ° clockwise. Next, the light reflected by the first reflecting surface 65a travels through the second prism 65, then reflects by the second reflecting surface 65b, and the optical path of the light is bent 90 ° counterclockwise. In this way, the optical path of the light emitted from the fourth semiconductor laser 43D approaches the optical path of the emitted light from the third semiconductor laser 43C after the light guide optical system 63 is emitted.

  Also in this embodiment, the same effect as 1st Embodiment that the size reduction of the light source device 62 can be achieved and the projector 1 can be reduced in size is obtained.

  In the case of this embodiment, the light guide optical system 63 is composed of a first prism 64 and a second prism 65, and the parallelism of the two reflecting surfaces of each prism is determined by the processing accuracy at the time of prism fabrication. Therefore, it is possible to realize the light guide optical system 63 that does not depend on the mounting accuracy of the prism. Therefore, the optical axis of the light incident on the light guide optical system 63 and the optical axis of the light emitted from the light guide optical system 63 can be easily made parallel. Further, the light guide optical system 63 reduces the width of the entire light beam emitted from the plurality of semiconductor lasers 43, and the first reflective element 23 can be reduced in size as in the first embodiment. The effect is obtained.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the light source device of the above embodiment, a parabolic mirror is used as the first reflecting element and an aspherical mirror is used as the second reflecting element, but the specific configuration of the reflecting element is not limited to the above example. It can be changed as appropriate. In addition, the shape, number, arrangement, material, and the like of various components of the light source device and the projector are not limited to the above-described embodiment, and can be changed as appropriate.

  In the said embodiment, although the light source device by this invention was shown mounted in the projector using a liquid crystal light valve, it was not restricted to this. You may mount in the projector using a digital micromirror device as a light modulation apparatus.

  In the above embodiment, the example in which the light source device according to the present invention is mounted on the projector has been shown, but the present invention is not limited to this. The light source device according to the present invention can also be applied to lighting fixtures, automobile headlights, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2, 62 ... Light source device, 4R, 4G, 4B ... Light modulation device, 6 ... Projection optical system, 21 ... Light source unit, 22, 63 ... Light guide optical system, 23 ... First reflection element, 24 ... 2nd reflective element, 43 ... Semiconductor laser (solid light source), 43A ... 1st semiconductor laser (1st solid light source), 45 ... Mirror, 47 ... Phosphor layer, 64 ... 1st prism, 65 ... Second prism.

Claims (6)

A light source unit comprising a plurality of solid state light sources;
A first reflective element that reflects light emitted from the light source unit;
A second reflective element that is disposed in a light emitting direction of the first solid light source among the plurality of solid light sources and reflects the light reflected by the first reflective element;
A phosphor layer on which the light reflected by the second reflecting element is incident;
A light guide optical system for guiding the light emitted from the first solid-state light source to the first reflective element, bypassing the second reflective element;
A light source device comprising:   The light source device according to claim 1, wherein the light guide optical system includes a pair of mirrors.   The light source device according to claim 1, wherein the light guide optical system includes a prism having two reflecting surfaces.   4. The optical axis of light incident on the light guide optical system and the optical axis of light emitted from the light guide optical system are substantially parallel to each other. 5. The light source device according to 1.   The optical axis of the light emitted from the first solid light source and emitted from the light guide optical system is the same as the optical axis of the light emitted from the second solid light source of the plurality of solid light sources. The light source device according to any one of claims 1 to 4, wherein the light source device is located between an optical axis of light emitted from the solid light source. A light source device according to any one of claims 1 to 5,
A light modulation device that forms image light by modulating light emitted from the light source device according to image information; and
And a projection optical system that projects the image light.

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