JP2014075221A - Light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device which is simple, small, cheap and having long service life without using a polarization characteristic by a quarter wavelength plate and the like.SOLUTION: A light source device 10 includes: an LD1 which emits excitation light Lx; a fluorescent wheel 6 which is divided into a plurality of regions along an outer periphery, and in which the plurality of regions are configured by a region where a reflection surface exists and a region where a phosphor layer 6p exists; and a dichroic mirror 4 which has a spectral characteristic for reflecting the excitation light Lx emitted from the LD1 and for transmitting fluorescent light Lm emitted from the phosphor layer 6p by the phosphor layer 6p of the fluorescent wheel 6 being irradiated with the excitation light Lx. A path of the excitation light Lx coming into the fluorescent wheel 6 from the LD1 and a path of reflection light Lr of the excitation light Lx reflected by the reflection surface of the fluorescent wheel 6 are different. The dichroic mirror 4 is arranged only in the path of the excitation light Lx coming into the fluorescent wheel 6 from the LD1.

Description

  The present invention relates to a light source device including a phosphor that emits fluorescent light when irradiated with excitation light.

  Since light-emitting diodes have a longer life than conventional light sources such as fluorescent lamps and incandescent lamps, they have recently been used as light sources for various lighting devices as their luminous efficiency and luminous flux improve. Also in projectors that project personal computer images and video images on a screen, semiconductor light emitting devices such as light emitting diodes and laser diodes are beginning to be used instead of high pressure mercury lamps. Hereinafter, the light emitting diode is referred to as LED and the laser diode is referred to as LD.

  In the projector, light is emitted to display elements such as a digital micromirror device (DMD) and a liquid crystal panel, and image light reflected or transmitted by each pixel of the display element is imaged on a screen. Basically, the display element is irradiated with light of three colors, red, green, and blue, in which the white light of the lamp is time-divided with a color wheel or dispersed with a dichroic mirror.

  In projectors using LEDs and LDs, all red, green, and blue light can also be generated by LEDs and LDs, but the green semiconductor light-emitting elements emit light more efficiently than other red and blue semiconductor light-emitting elements. Is low. For this reason, generally green light is produced | generated by the fluorescent light which used blue light and ultraviolet light as excitation light using a fluorescent substance (for example, refer patent document 1, 2). Similarly, red light may be generated by fluorescent light.

  Since several tens of watts of excitation light is condensed and irradiated on the green and red phosphors, a phosphor layer is formed on the disk for the purpose of suppressing efficiency deterioration due to burning or temperature rise, and secular change. By rotating, the irradiation position of the excitation light is not limited to one point. This disk is called a fluorescent wheel, and a phosphor is sealed with a transparent resin such as silicone on a circular reflector or a transparent substrate. The phosphor layer is formed in a sector shape or an annular shape along the outer periphery of the disc.

  In the apparatus described in Patent Document 1, since blue light is used as excitation light and this blue light is also used for image light projected onto a screen, the fluorescent wheel is divided into a plurality of regions and the excitation light is divided into one region. Diffuse transmission. In the region emitting green light, the base of the phosphor layer is a reflector. That is, the light path is as if it passes through the fluorescent wheel and reflects blue light. Moreover, in the apparatus described in Patent Document 1, red light is not generated by a phosphor, but a light source that emits red light is separately provided.

  In the apparatus described in Patent Document 2, as in Patent Document 1, blue excitation light is used for image light, but the region of the fluorescent wheel is used as a reflective surface. That is, the blue excitation light is reflected by the fluorescent wheel in the same direction as the green and red fluorescent lights, but the excitation light polarization characteristics are used so that the blue excitation light does not return to the excitation light source for 4 minutes. The light is guided to a light guide device (rod integrator) by a single wavelength plate and a dichroic mirror.

JP 2011-13320 A JP 2012-108486 A

  When using blue excitation light for image light, if the blue excitation light is transmitted by the fluorescent wheel and the green fluorescent light is reflected, the excitation light is condensed both before and after the fluorescent wheel. A lens group for collimating the fluorescent light and the diffusely transmitted excitation light in parallel is required. In addition to separating the optical paths of excitation light and fluorescent light, and combining the optical path of fluorescent light and diffused and transmitted excitation light, a minimum of two dichroic mirrors and other relay lenses and mirrors are required. The optical path of the device becomes complicated and the light source device becomes large.

  On the other hand, when blue excitation light and green and red fluorescent light are reflected in the same direction, the number of these lenses, mirrors, and dichroic mirrors can be greatly reduced, and the light source device is simplified and miniaturized. Is possible. Instead, in order to utilize polarization characteristics, the light source device requires a quarter wave plate. An inexpensive quarter-wave plate having a polymer film on a glass substrate has a low heat-resistant temperature and yellows due to blue light as excitation light, so that the life of the quarter-wave plate is short. An inorganic quarter-wave plate such as quartz does not cause these problems, but is expensive, so that the manufacturing cost of the light source device increases.

  Accordingly, an object of the present invention is to provide a light source device that is simple, small-sized, inexpensive, and has a long life without using polarization characteristics such as a quarter-wave plate.

  A light source device according to the present invention includes an excitation light source that emits excitation light, a plurality of regions that are divided along the outer periphery, and a region where a reflecting surface is present and a region where a phosphor layer is present And the excitation light emitted from the excitation light source is reflected, and the excitation light is emitted from the phosphor layer by irradiating the phosphor layer of the fluorescence wheel. A first dichroic mirror having a spectral characteristic that transmits the fluorescent light, and the excitation light that is incident on the fluorescent wheel from the excitation light source and the excitation light that is reflected by the reflecting surface of the fluorescent wheel. Unlike the reflected light path, the first dichroic mirror is disposed only in the path of the excitation light incident on the fluorescent wheel from the excitation light source.

  According to the present invention, an excitation light source, a fluorescence wheel, and a first dichroic mirror are provided, and a path of excitation light incident on the fluorescence wheel from the excitation light source and reflection of excitation light reflected by the reflection surface of the fluorescence wheel. Unlike the light path, the first dichroic mirror is disposed only in the path of the excitation light incident on the fluorescent wheel from the excitation light source.

  Therefore, the fluorescent light emitted from the phosphor layer passes through the first dichroic mirror and is emitted to the outside through a region where the first dichroic mirror is not disposed. And the reflected light of the excitation light reflected by the reflecting surface of the fluorescent wheel is also emitted to the outside through a region where the first dichroic mirror is not disposed.

  Thereby, a light source device that emits a plurality of colors of image light can be realized. In this case, since the light source device does not require a quarter-wave plate, there are no problems such as yellowing and low heat-resistant temperature. For this reason, a long-life light source device can be realized. Further, since the light source device can be configured with a small number of components, a light source device that is small, light, and inexpensive can be realized.

(A) It is a schematic block diagram (when excitation light is irradiated to a fluorescent substance layer) of the light source device which concerns on Embodiment 1. FIG. (B) It is a schematic block diagram (when excitation light is irradiated to the area | region where the fluorescent substance layer on a fluorescent wheel does not exist) of the light source device which concerns on Embodiment 1. FIG. 3 is a front view of a fluorescent wheel of the light source device according to Embodiment 1. FIG. FIG. 6 is a schematic configuration diagram of a light source device according to Modification 1 of Embodiment 1. (A) It is a schematic block diagram (when excitation light is irradiated to a fluorescent substance layer) of the light source device which concerns on the modification 3 of Embodiment 1. FIG. (B) It is a schematic block diagram of the light source device which concerns on the modification 3 of Embodiment 1 (when excitation light is irradiated to the area | region where the fluorescent substance layer on a fluorescent wheel does not exist). 5 is a schematic configuration diagram of a light source device according to Embodiment 2. FIG. 6 is a front view of a fluorescent wheel of a light source device according to Embodiment 2. FIG. FIG. 10 is a schematic configuration diagram of a light source device according to Modification 1 of Embodiment 2. FIG. 10 is a schematic configuration diagram of a light source device according to a second modification of the second embodiment.

<Embodiment 1>
Embodiment 1 of the present invention will be described below with reference to the drawings. 1A and 1B are schematic configuration diagrams of a light source device 10 according to Embodiment 1 of the present invention. FIG. 1A shows a case where the excitation light Lx is applied to the phosphor layer 6p on the fluorescent wheel 6, and the excitation light Lx is applied to a region where the fluorescent wheel 6 rotates and the fluorescent material layer 6p does not exist. The case is shown in FIG.

  The light source device 10 includes a plurality of LD 1 (excitation light source), a plurality of collimator lenses 2, a heat sink 3, a dichroic mirror 4 (first dichroic mirror), a condenser lens 5, a fluorescent wheel 6, and a motor 7. It has.

  The LD 1 is an excitation light source that emits blue excitation light Lx, and is arrayed and mounted in a vertical and horizontal two-dimensional direction on a substrate (not shown). The collimator lens 2 is disposed in front of the LD 1 and collimates the excitation light Lx emitted from each LD 1. The heat sink 3 is provided on the opposite side of the collimator lens 2 across the LD 1 and cools the LD 1. In addition, you may employ | adopt LED instead of LD as an excitation light source.

  The dichroic mirror 4 has a spectral characteristic that reflects the blue excitation light Lx and transmits the green and red fluorescent light Lm. Therefore, the dichroic mirror 4 reflects the excitation light Lx collimated by the collimator lens 2 and makes the excitation light Lx enter the condenser lens 5. The condensing lens 5 condenses the excitation light Lx incident from the dichroic mirror 4 on the fluorescent wheel 6. At this time, the excitation light Lx passes through approximately half of the condenser lens 5. That is, in FIGS. 1A and 1B, the excitation light Lx passes through the lower half area from the optical axis A of the condenser lens 5 and is irradiated onto the fluorescent wheel 6. Here, the dichroic mirror 4 is disposed only in the path of the excitation light Lx that enters the fluorescent wheel 6 from the LD 1. That is, the dichroic mirror 4 exists only in the lower half area from the optical axis A of the condenser lens 5 and does not exist in the upper half area.

  The fluorescent wheel 6 is made of a metal such as silver on a circular substrate 6a (see FIG. 2) having a high heat transfer coefficient such as aluminum, a reflective coating or a protective coating on it, and a phosphor on the coating. The phosphor layer 6p sealed with a transparent resin such as is formed. The phosphor layer 6p is formed in a fan shape along the outer periphery of the circular substrate 6a.

  A condenser lens 8 and a light guide device 9 (rod integrator) are disposed outside an opening (not shown) of the light source device 10. More specifically, the condenser lens 8 and the light guide device 9 are disposed at positions facing the condenser lens 5.

  Next, the fluorescent wheel 6 will be described with reference to FIG. FIG. 2 is a front view of the fluorescent wheel 6, that is, a view of the fluorescent wheel 6 viewed from the condenser lens 5 side. The fluorescent wheel 6 is divided into a plurality of regions along the outer periphery of the circular substrate 6a, and the plurality of regions includes a blue region 6b and a region where the phosphor layer 6p exists. The blue region 6b is a reflecting surface on which the phosphor layer 6p is not provided. The region where the phosphor layer 6p is present is divided into a green region 6g where the green phosphor is sealed and a red region 6r where the red phosphor is sealed.

  The rotation wheel of the motor 7 is attached to the center of the fluorescent wheel 6 so that it can rotate. In accordance with the rotation of the motor 7, the irradiation point of the excitation light Lx on the fluorescent wheel 6 is periodically and sequentially moved to the blue region 6b, the green region 6g, and the red region 6r. FIG. 1A shows the behavior of the fluorescent light Lm when the excitation light Lx is applied to the phosphor layer 6p having the green region 6g and the red region 6r. FIG. 1B shows the behavior of the reflected light Lr when the excitation light Lx is applied to the blue region 6b.

  Since the fluorescent light Lm is emitted from the phosphor layer 6p to the condensing lens 5 side with a completely diffused light distribution, the fluorescent light Lm is condensed in the entire region of the condensing lens 5 and collimated in parallel. The dichroic mirror 4 has a spectral characteristic of reflecting the blue excitation light Lx and transmitting the green and red fluorescent lights Lm, so that the fluorescent light Lm collimated by the condenser lens 5 is applied to the condenser lens 8. To reach.

  On the other hand, since the dichroic mirror 4 is disposed only in the path of the excitation light Lx incident from the LD 1 to the fluorescent wheel 6, the reflected light Lr reflected by the blue region 6b of the fluorescent wheel 6 is incident excitation light. It passes through a path different from Lx, that is, in the upper half of the optical axis A of the condenser lens 5 in FIG.

  The fluorescent light Lm and the reflected light Lr are collected by the condenser lens 8 and are incident on the light guide device 9. The light beam emitted from the light guide device 9 is irradiated onto the display element by an illumination optical system (not shown) and projected onto the screen by a projection optical system (not shown). That is, by rotating the fluorescent wheel 6, red, green, and blue image lights are sequentially emitted from the light source device 10 in time series, and a color image is created.

  As described above, the light source device 10 according to the first embodiment includes the LD 1, the fluorescent wheel 6, and the dichroic mirror 4, the path of the excitation light Lx that enters the fluorescent wheel 6 from the LD 1, and the fluorescent wheel 6. Unlike the path of the reflected light Lr of the excitation light Lx reflected by the reflecting surface, the dichroic mirror 4 is disposed only on the path of the excitation light Lx incident from the LD 1 to the fluorescent wheel 6.

  Therefore, the fluorescent light Lm emitted from the phosphor layer 6p is transmitted through the dichroic mirror 4 and passes through an area where the dichroic mirror 4 is not disposed (an upper half area from the optical axis A of the condenser lens 5). To the condenser lens 8. Then, the reflected light Lr of the excitation light Lx reflected by the reflecting surface of the fluorescent wheel 6 also passes through a region where the dichroic mirror 4 is not disposed (a region above the optical axis A of the condensing lens 5). It reaches the optical lens 8.

  Thereby, the light source device 10 that emits image light of a plurality of colors (red, green, and blue) can be realized. In this case, since the light source device 10 does not require a quarter-wave plate, there are no problems such as yellowing and a low heat-resistant temperature. For this reason, the long-life light source device 10 is realizable. Further, since the light source device 10 can be configured with a small number of parts, the light source device 10 that is small, light, and inexpensive can be realized.

  Further, from the above, the fluorescent light Lm and the reflected light Lr are guided to the light guide device 9 without waste, so that the light use efficiency is increased, and as a result, the energy consumption in the light source device 10 can be reduced.

<Modification 1>
Next, a light source device 10A according to Modification 1 of Embodiment 1 will be described with reference to FIG. FIG. 3 is a schematic configuration diagram of the light source device 10A according to the first modification of the first embodiment, and shows a case where the excitation light Lx is irradiated to a region where the phosphor layer 6p on the fluorescent wheel 6 does not exist. .

  The plurality of LDs 1 are arranged at positions where the excitation light Lx incident on the fluorescent wheel 6 is asymmetric with respect to the optical axis A of the condenser lens 5 in the vertical direction of FIG. Further, the LD 1 is arranged with a larger interval in the left-right direction in FIG. 3 than in the case of FIG. The excitation light Lx and the reflected light Lr are different paths, and the plurality of strip-shaped dichroic mirrors 4 are arranged in individual paths in the excitation light Lx. In other words, the plurality of dichroic mirrors 4 are arranged at predetermined intervals. The reflected light Lr passes between the adjacent dichroic mirrors 4 and reaches the condenser lens 8.

  As described above, in the light source device 10A according to the first modification of the first embodiment, the interval in one direction (left and right direction in FIG. 3) of the LD1 arrayed two-dimensionally can be increased. Can be effectively reduced, and the life of the LD 1 can be extended. Further, in FIG. 1B, the reflected light Lr is incident on the light guide device 9 with a deviation from the upper half of the optical axis A of the condenser lens 5 in FIG. Are uniformly incident on the light guide device 9, the light guide distance and length of the light guide device 9 can be shortened, and the entire projector including the light source device 10A can be downsized.

<Modification 2>
In FIG. 3, a plurality of strip-shaped dichroic mirrors 4 are arranged, but a dichroic mirror having a striped dichroic coat on a single glass substrate may be employed. In this case, it is desirable to apply an antireflection coat between adjacent dichroic coats and on the back surface. By doing so, it becomes easy to handle the dichroic mirror when assembling the light source device.

<Modification 3>
Next, a light source device 10B according to Modification 3 of Embodiment 1 will be described with reference to FIGS. 4 (a) and 4 (b). 4A and 4B are schematic configuration diagrams of a light source device 10B according to the third modification of the first embodiment. FIG. 4A shows a case where the excitation light Lx is applied to the phosphor layer 6p on the fluorescent wheel 6, and the excitation light Lx is applied to the blue region 6b where the fluorescent wheel 6 rotates and the fluorescent material layer 6p does not exist. The case where this is done is shown in FIG.

  The light source device 10B is a device that further includes a reflection mirror 15 by replacing the dichroic mirror 4 of Embodiment 1 with a dichroic mirror 14 (first dichroic mirror) having spectral characteristics different from those of the dichroic mirror 4. LD1 is arrange | positioned in the position facing the lower part of the condensing lens 5. FIG.

  The dichroic mirror 14 has a spectral characteristic of transmitting the blue excitation light Lx emitted from the LD 1 and reflecting the green and red fluorescent lights Lm emitted from the phosphor layer 6p. The dichroic mirror 14 is disposed only in the path of the excitation light Lx that enters the fluorescent wheel 6 from the LD 1. The reflection mirror 15 has an optical characteristic of reflecting the blue excitation light Lx, green and red fluorescent light Lm, and is disposed only in the path of the reflected light Lr of the excitation light Lx reflected by the reflection surface of the fluorescent wheel 6. ing.

  The condensing lens 8 and the light guide device 9 are arranged at positions where the fluorescent light Lm and the reflected light Lr reflected by the dichroic mirror 14 and the reflecting mirror 15 can enter (below the dichroic mirror 14 and the reflecting mirror 15 in FIG. 4). Is arranged.

  As described above, the light source device 10B according to the third modification of the first embodiment further includes the reflection mirror 15, the dichroic mirror 14 transmits the excitation light Lx emitted from the LD1, and the excitation light Lx is The reflection mirror 15 has a spectral characteristic that reflects the fluorescent light Lm emitted from the phosphor layer 6p by being irradiated on the phosphor layer 6p of the phosphor wheel 6, and the reflection mirror 15 is excited by being reflected by the reflecting surface of the fluorescence wheel 6. It is disposed only on the path of the reflected light Lr of the light Lx.

  Therefore, the fluorescent light Lm emitted from the phosphor layer 6 p is reflected by the dichroic mirror 14 and the reflection mirror 15 and reaches the condenser lens 8. Then, the reflected light Lr of the excitation light Lx reflected by the reflecting surface of the fluorescent wheel 6 is also reflected by the reflecting mirror 15 and reaches the condenser lens 8. Thereby, it turns out that the light source device 10B has the same function as the light source device 10 according to the first embodiment. That is, it is possible to realize the light source device 10B that emits a plurality of colors (red, green, and blue) of video light.

  Note that when an LD is employed as the excitation light source, the reflected light Lr of the excitation light Lx is directly used as image light, so speckle peculiar to laser light may be a problem. Although the efficiency of incidence on the light guide device 9 is reduced, speckle can be alleviated by using a reflective surface with irregularities on the surface of the blue region 6b of the fluorescent wheel 6 or a reflective surface with a texture.

<Embodiment 2>
Next, the light source device 10C according to Embodiment 2 will be described with reference to FIGS. FIG. 5 is a schematic configuration diagram of the light source device 10C according to the second embodiment, and FIG. 6 is a front view of the fluorescent wheel 6A of the light source device 10C according to the second embodiment. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The light source device 10C is the same as the light source device 10 according to the first embodiment in that the red region 6r and the blue region 6b in which the red phosphor of the fluorescent wheel 6A is sealed have the same reflecting surface, and further a red semiconductor light emitting element This is an apparatus including the LD 21 and a dichroic mirror 16 (second dichroic mirror). Since the red phosphor has a large Stokes shift from blue light, the light emission efficiency is low. However, a light source device 10C with higher luminance can be realized by switching to a semiconductor light emitting element having a high light emission efficiency. Moreover, since the heat generation of the fluorescent wheel 6A is suppressed, the life of the fluorescent wheel 6A can be extended.

  The fluorescent wheel 6A is divided into a plurality of regions along the outer periphery of the circular substrate 6a. The plurality of regions are a blue region 6b, a red region 6r, and a green region 6g where the phosphor layer 6p exists. It is configured. The blue region 6b and the red region 6r are reflective surfaces on which the phosphor layer 6p is not provided. Since the blue region 6b and the red region 6r are the same reflection surface, no boundary actually exists between the two regions. The phosphor layer 6p sealed with the green phosphor is formed only in the green region 6g.

  The light source device 10C includes a plurality of LDs 21 (second light sources) that emit red light Lb, instead of the phosphor layer 6p having no region where the red phosphor is sealed. Similarly to the case of the first embodiment, the light source device 10C includes a plurality of LDs 1 that emit blue light La that is excitation light. A plurality of collimator lenses 2 are arranged in front of the LD 21, and a heat sink 3 is arranged on the opposite side of the collimator lens 2 separately from the heat sink 3 for the LD 1. Instead of using a red LD as the light source, an LED may be used.

  FIG. 5 shows a case where the blue light La and the red light Lb are reflected by the blue region 6 b and the red region 6 r on the fluorescent wheel 6. That is, FIG. 5 shows a form in which the red LD 21 and the dichroic mirror 16 are added to FIG. 1B shown in the first embodiment.

  The dichroic mirror 4 has a spectral characteristic that reflects blue light La and transmits green fluorescent light (hereinafter also referred to as “green light”) and red light Lb. La is disposed on a path on which the light enters the fluorescent wheel 6A.

  The dichroic mirror 16 has a spectral characteristic of reflecting the red light Lb and transmitting the green fluorescent light and the blue light La, and the dichroic mirror 16 is a path through which the red light Lb enters the fluorescent wheel 6A. Is placed on top.

  The blue light La emitted from the LD 1 is reflected by the dichroic mirror 4 and applied to the fluorescent wheel 6A via the condenser lens 5. Further, the red light Lb emitted from the LD 21 is reflected by the dichroic mirror 16 and is irradiated onto the fluorescent wheel 6 </ b> A via the condenser lens 5. The reflected light from the fluorescent wheel 6A in the blue light La passes through the dichroic mirror 16 and reaches the condenser lens 8, and the reflected light from the fluorescent wheel 6A in the red light Lb passes through the dichroic mirror 4 and is condensed. The lens 8 is reached. Thus, in both the blue light La and the red light Lb, the path incident on the fluorescent wheel 6A is different from the path reflected by the fluorescent wheel 6A.

  In the case of extracting the green light, the blue light La is the excitation light and the dichroic mirrors 4 and 16 both transmit the green light as in the case of the first embodiment. Therefore, the fluorescent light emitted from the phosphor layer 6p ( Green light) reaches the condenser lens 8.

  As described above, in the light source device 10C according to the second embodiment, the excitation light (blue light La) emitted from the LD1 and the excitation light (blue light La) are applied to the phosphor layer 6p of the fluorescent wheel 6A. The dichroic mirror 4 further includes a dichroic mirror 16 having a spectral characteristic of transmitting the fluorescent light (green light) emitted from the phosphor layer 6p and reflecting the red light Lb emitted from the LD 21. Fluorescence light reflected from the phosphor layer 6p by reflecting the excitation light (blue light La) emitted from the LD 1 and irradiating the phosphor layer 6p of the phosphor wheel 6A with the excitation light (blue light La). The dichroic mirror 16 has a spectral characteristic that transmits the (green light) and the red light Lb emitted from the LD 21, and the dichroic mirror 16 receives the red light Lb that enters the fluorescent wheel 6 A from the LD 21. It is disposed only in the path.

  That is, for both the blue light La and the red light Lb incident on the fluorescent wheel 6A, the reflected light is used as a different path, and the dichroic mirror 4 is disposed on the path where the blue light La is incident on the fluorescent wheel 6A. In addition, the dichroic mirror 16 is disposed on the optical path on which the red light Lb is incident on the fluorescent wheel 6A, so that the light source device 10C that emits image light of a plurality of colors (red, green, and blue) is provided. realizable.

  In addition, since the light source device 10C according to Embodiment 2 does not use a red phosphor with low light emission efficiency, a light source device 10C with higher luminance can be realized. Moreover, since the heat generation of the fluorescent wheel 6A is suppressed, the life of the fluorescent wheel 6A can be extended.

  Since the light source device 10C is provided with the heat sink 3 individually so as to correspond to the LD1 and LD21, heat when the LD1 is lit is not easily transmitted to the LD21, and heat when the LD21 is lit is not easily transmitted to the LD1. Furthermore, since the temperatures of LD1 and LD21 can be controlled independently, the lifetime of LD1 and LD21 can be extended.

<Modification 1>
Next, a light source device 10D according to Modification 1 of Embodiment 2 will be described with reference to FIG. FIG. 7 is a schematic configuration diagram of a light source device 10D according to the first modification of the second embodiment. FIG. 7 shows a mode in which the LD 21 that emits the red light Lb and the dichroic mirror 16 are added to FIG. 3 shown in the first modification of the first embodiment.

  The plurality of LDs 1 are arranged at positions where the blue light La that is excitation light incident on the fluorescent wheel 6 is asymmetric in the vertical direction of FIG. 7 with respect to the optical axis A of the condenser lens 5. Further, the LD 1 is arranged with a larger interval in the left-right direction in FIG. 7 than in the case of FIG. The plurality of LDs 21 are respectively arranged at positions adjacent to the LD 1.

  The plurality of strip-shaped dichroic mirrors 4 are arranged in individual paths of the blue light La that is excitation light. In addition, the plurality of strip-shaped dichroic mirrors 16 are arranged in individual paths of the red light Lb. That is, the plurality of dichroic mirrors 4 are arranged at predetermined intervals, and the plurality of dichroic mirrors 16 are respectively arranged at positions adjacent to the dichroic mirror 4.

  As described above, in the light source device 10D according to the first modification of the second embodiment, the blue light La is biased from the upper half region from the optical axis A of the condenser lens 5 with respect to the light guide device 9 in FIG. In addition, compared to the case where the red light Lb is incident on the light guide device 9 with a bias from the lower half of the optical axis A of the condenser lens 5, the blue light La and the red light Lb are incident on the light guide device 9. Since light is uniformly incident on the light guide device 9, the light guide distance and length of the light guide device 9 can be shortened. Thereby, the whole projector including light source device 10D can be reduced in size.

  5 and 7, the dichroic mirrors 4 and 16 may be arranged in a straight line, or a member obtained by separately coating a dichroic coat corresponding to the dichroic mirrors 4 and 16 on one glass substrate. It may be adopted. It is desirable to provide an antireflection coating on the back side of the dichroic mirror. When the dichroic mirrors 4 and 16 are separately coated on one glass substrate, handling of the dichroic mirrors when assembling the light source devices 10C and 10D becomes easy.

<Modification 2>
Next, a light source device 10E according to Modification 2 of Embodiment 2 will be described. FIG. 8 is a schematic configuration diagram of a light source device 10E according to the second modification of the second embodiment. In the light source device 10E according to the second modification of the second embodiment, the LDs 1 and 21 are connected to the condenser lens 5 in the same manner as in the third modification of the first embodiment shown in FIGS. It is the structure arrange | positioned in the position which opposes.

  The light source device 10E has a dichroic mirror 14 having spectral characteristics that transmits blue light La and reflects green light and red light Lb, and has spectral characteristics that transmits red light Lb and reflects blue light La and green light. A dichroic mirror 17 (second dichroic mirror) is provided. The dichroic mirror 14 is disposed on the optical path where the blue light La is incident on the fluorescent wheel 6, and the dichroic mirror 17 is disposed on the optical path where the red light Lb is incident on the fluorescent wheel 6.

  The condensing lens 8 and the light guide device 9 are disposed at positions where the blue light La and the red light Lb reflected by the dichroic mirrors 14 and 17 can enter (below the dichroic mirrors 14 and 17 in FIG. 8). .

  The blue light La emitted from the LD 1 passes through the dichroic mirror 14, is reflected by the blue region 6 b of the fluorescent wheel 6 A and the dichroic mirror 17, and reaches the condenser lens 8. The red light Lb emitted from the LD 21 passes through the dichroic mirror 17, is reflected by the red region 6 r of the fluorescent wheel 6 A and the dichroic mirror 14, and reaches the condenser lens 8. When the green light is extracted, the blue light La is the excitation light and the dichroic mirrors 14 and 17 both reflect the green light, so that the fluorescent light (green light) emitted from the phosphor layer 6p is similar to the above. It reaches the condenser lens 8. That is, the light source device 10E that emits a plurality of (three colors of red, green, and blue) video light can be realized.

  As described above, in the light source device 10E according to the second modification of the second embodiment, the dichroic mirror 14 transmits the excitation light (blue light La) emitted from the LD1, and the excitation light (blue light La). Is applied to the phosphor layer 6p of the phosphor wheel 6A, and has a spectral characteristic that reflects the fluorescent light (green light) emitted from the phosphor layer 6p and the red light Lb emitted from the LD 21, and is dichroic. The mirror 17 emits the excitation light (blue light La) emitted from the LD 1 and the fluorescent light emitted from the phosphor layer 6p when the excitation light (blue light La) is irradiated onto the phosphor layer 6p of the fluorescent wheel 6A. It has a spectral characteristic that reflects (green light) and transmits the red light Lb emitted from the LD 21.

  Therefore, as in the case of the light source device 10C according to the second embodiment, a red phosphor with low light emission efficiency is not used, and thus a light source device 10E with higher luminance can be realized. Moreover, since the heat generation of the fluorescent wheel 6A is suppressed, the life of the fluorescent wheel 6A can be extended.

  As in the case of the first embodiment, when the LD is employed as the excitation light source and the red semiconductor light emitting element, the reflected light of the blue light La and the red light Lb is directly used as the image light. May be a problem. Although the efficiency of incidence on the light guide device 9 is reduced, speckle can be alleviated by using a reflective surface with irregularities on the surface of the blue region 6b and the red region 6r or a reflective surface with a texture on the fluorescent wheel 6A. Can do.

  Further, as in the case of the first modification of the second embodiment shown in FIG. 7, the plurality of LDs 1 are arranged with a wider interval in the left-right direction than the case of FIG. 8, and the plurality of LDs 21 are Each of the dichroic mirrors 14 is disposed at a predetermined interval, and the plurality of dichroic mirrors 17 is disposed at a position adjacent to the dichroic mirror 14. Also good.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  DESCRIPTION OF SYMBOLS 1 Excitation light source (LD), 4,14 1st dichroic mirror, 6,6A fluorescent wheel, 6p fluorescent substance layer 10, 10A, 10B, 10C, 10D, 10E Light source device, 15 Reflection mirror, 16, 17 2nd dichroic Mirror, 21 second light source (LD).

Claims (5)

An excitation light source that emits excitation light;
A fluorescent wheel that is divided into a plurality of regions along an outer periphery, and the plurality of regions includes a region where a reflecting surface is present and a region where a phosphor layer is present;
Spectral characteristics of reflecting the excitation light emitted from the excitation light source and transmitting the fluorescence light emitted from the phosphor layer by irradiating the phosphor layer of the phosphor wheel with the excitation light. A first dichroic mirror having
The path of the excitation light incident on the fluorescent wheel from the excitation light source is different from the path of reflected light of the excitation light reflected by the reflection surface of the fluorescent wheel.
The first dichroic mirror is a light source device that is disposed only in a path of the excitation light that enters the fluorescent wheel from the excitation light source. A reflection mirror,
The first dichroic mirror transmits the excitation light emitted from the excitation light source instead of the spectral characteristics, and the excitation light is applied to the phosphor layer of the fluorescent wheel, thereby causing the fluorescence. It has spectral characteristics that reflect the fluorescent light emitted from the body layer,
The light source device according to claim 1, wherein the reflection mirror is disposed only in a path of the reflected light of the excitation light reflected by the reflection surface of the fluorescent wheel. A second light source that emits light having a wavelength different from that of the excitation light source;
The excitation light emitted from the excitation light source transmits the fluorescence light emitted from the phosphor layer by irradiating the phosphor layer of the phosphor wheel with the excitation light, and the second A second dichroic mirror having a spectral characteristic that reflects light emitted from the light source;
The first dichroic mirror has spectral characteristics that transmit light emitted from the second light source in addition to the spectral characteristics,
2. The light source device according to claim 1, wherein the second dichroic mirror is arranged only in a path of light emitted from the second light source that is incident on the fluorescent wheel from the second light source. The first dichroic mirror transmits the excitation light emitted from the excitation light source instead of the spectral characteristics, and the excitation light is applied to the phosphor layer of the fluorescent wheel, thereby causing the fluorescence. Having a spectral characteristic of reflecting the fluorescent light emitted from the body layer and the light emitted from the second light source;
The second dichroic mirror emits from the phosphor layer by irradiating the phosphor layer of the phosphor wheel with the excitation light emitted from the excitation light source, instead of the spectral characteristics. The light source device according to claim 3, wherein the light source device has a spectral characteristic of reflecting the fluorescent light to be transmitted and transmitting the light emitted from the second light source.   The light source device according to claim 1, wherein unevenness is provided on a surface of the reflecting surface of the fluorescent wheel.

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