Light source device

Abstract

To provide a light source device that has a circular beam shape of output light and substantially uniform hue distribution of output light.SOLUTION: A light source device according to one embodiment of the present invention comprises a phosphor, a light source unit, and an off-axis parabolic mirror. The light source unit allows a light incident surface of the phosphor to be irradiated with incident excitation light capable of exciting the phosphor. The off-axis parabolic mirror allows combination of reflected excitation light, which is light of the incident excitation light that is reflected on the light incident surface, with fluorescent light emitted from the phosphor, and allows the combined light obtained as a result to be output to the outside as output light.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a light source device that excites a phosphor with excitation light and emits light emitted from the phosphor. [Background technology]

[0002] Conventional phosphor light sources are disclosed in, for example, Patent Documents 1-3.

[0003] Patent documents 1 and 2 disclose a method of obtaining output light by arranging a flat phosphor at the focal position of a rotating parabolic mirror or a rotating spherical mirror, irradiating the phosphor with excitation light through an opening provided in the rotating parabolic mirror or the rotating spherical mirror, and reflecting the wavelength-converted fluorescence by the rotating parabolic mirror or the rotating spherical mirror. Patent document 3 discloses a method of obtaining output light by arranging a flat phosphor at the focal position of a parabolic mirror having as a reflecting surface at least a part of a partial curved surface obtained by cutting a curved surface (parabolic curved surface) formed by rotating a parabola around the symmetrical axis of the parabola as the rotation axis, with the above-mentioned rotation axis included, and irradiating the phosphor with excitation light through an opening provided in the parabolic mirror, and reflecting the wavelength-converted fluorescence by the parabolic mirror. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-200782 A [Patent Document 2] JP 2005-150041 A [Patent Document 3] Patent No. 5842041 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in Patent Documents 1 and 2, there are problems in that the beam shape of the output light is doughnut-shaped and the color of the output light is non-uniform. In addition, in Patent Document 3, there are problems in that the beam shape of the output light is semicircular and the color of the output light is partially non-uniform. Therefore, it is desirable to provide a light source device in which the beam shape of the output light is circular and the color distribution of the output light is approximately uniform. [Means for solving the problem]

[0006] A light source device according to an embodiment of the present invention includes a phosphor, a light source unit, and an off-axis parabolic mirror. The light source unit is capable of irradiating an incident excitation light, which is an excitation light capable of exciting the phosphor, onto a light incident surface of the phosphor. The off-axis parabolic mirror is capable of combining reflected excitation light, which is a part of the incident excitation light that is reflected by the light incident surface, with fluorescent light emitted from the phosphor, and outputting the combined light obtained as a result to the outside as output light. Effect of the Invention

[0007] According to a light source device of one embodiment of the present invention, an off-axis parabolic mirror is irradiated with reflected excitation light, which is light of incident excitation light reflected at the light incident surface, and fluorescent light emitted from a phosphor, and the combined light obtained by reflection at the off-axis parabolic mirror is output to the outside as output light. Therefore, the beam shape of the output light can be made circular, and the color distribution of the output light can be made approximately uniform. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a light source device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing an example of the distribution of the amount of fluorescent light emitted from the phosphor of FIG. [Diagram 3]FIG. 3 shows an example of the relationship between the divergence angle θy of the component of the fluorescent light L3 that is incident on the off-axis parabolic mirror 30 and m, when the off-axis angle θf is 90°, the optical focal length Lf is the mirror size Lm, and the reflection focal length Lr is m times the mirror size Lm (hereinafter referred to as "optical condition A"). [Figure 4] FIG. 4 is a diagram showing an example of the dependence of the minimum angle θys between the normal to the phosphor and the component of the reflected excitation light that is incident on the off-axis parabolic mirror, under optical condition A, on the incident angle θi of the incident excitation light, as a function of the relationship between m. [Diagram 5] FIG. 5 is a diagram showing an example of the dependency of the integrated light amount of the fluorescent light incident on the off-axis parabolic mirror on the divergence angle θy when the minimum value θys is changed. [Figure 6] FIG. 6 is a diagram showing an example of the amount of fluorescent light emitted from the parabolic mirror when the divergence angle θy is changed, expressed as a value when the amount of light shown in FIG. 2 is set to 1. [Figure 7] FIG. 7 is a diagram showing an example of the chromaticity of the fluorescent light emitted from the parabolic mirror when the divergence angle θy is changed. [Figure 8] FIG. 8 is a diagram illustrating an example of the configuration of a light source device according to a comparative example. [Figure 9] FIG. 9 is a diagram illustrating a modified example of the configuration of the light source device in FIG. [Figure 10] FIG. 10 is a diagram illustrating a modified example of the configuration of the light source device in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiment of the invention will be described in detail with reference to the drawings. The following description is one specific example of the present invention, and the present invention is not limited to the following embodiment. Furthermore, the present invention is not limited to the arrangement, dimensions, and dimensional ratios of each component shown in each drawing.

[0010] Hereinafter, the embodiment of the invention will be described in detail with reference to the drawings. The following description is one specific example of the present invention, and the present invention is not limited to the following embodiment. Furthermore, the present invention is not limited to the arrangement, dimensions, and dimensional ratios of each component shown in each drawing.

[0011] <1. Preferred embodiment> [composition] The configuration of a light source device 1 according to an embodiment of the present invention will be described. Fig. 1 shows an example of the configuration of the light source device 1. The light source device 1 includes a light emitting section 10, a flat phosphor 20, an off-axis parabolic mirror 30, a lens group 40, and a heat sink 50.

[0012] The light-emitting unit 10 is capable of emitting excitation light (incident excitation light L1) capable of exciting the phosphor 20. The light-emitting unit 10 is capable of irradiating the incident excitation light L1 to the light incident surface of the phosphor 20 at an angle (incident angle θi) different from the normal NL to the light incident surface of the phosphor 20. The position where the light incident surface of the phosphor 20 and the optical axis EA of the incident excitation light L1 intersect is the focal position FP of the off-axis parabolic mirror 30.

[0013] The light-emitting unit 10 is disposed at a position where the optical axis EA of the incident excitation light L1 intersects with the normal NL of the light incident surface of the phosphor 20 at an incident angle θi. The incident angle θi is greater than 0° and smaller than 90°, for example, 45° or less. The light-emitting unit 10 is configured to include, for example, a semiconductor laser that emits the incident excitation light L1. The wavelength of the incident excitation light L1 is within the visible wavelength range, for example, within the blue wavelength range.

[0014] The wavelength of the incident excitation light L1 is not limited to a wavelength in the blue wavelength range, but is a wavelength capable of exciting the phosphor 20. The light emitting unit 10 may have a mirror that reflects the incident excitation light L1 and makes it incident on the phosphor 20. Even in such a case, the incident angle θi is an angle larger than 0° and smaller than 90°, for example, 45° or less.

[0015] The phosphor 20 is attached to the surface of the heat sink 50. This allows heat generated by the phosphor 20 to dissipate to the outside via the heat sink 50. The size of the phosphor 20 is larger than the diameter of the irradiation spot of the incident excitation light L1 irradiated on the phosphor 20. The thickness of the phosphor 20 is, for example, thick enough that the incident excitation light L1 does not pass through and leak out from the back surface. The thickness of the phosphor 20 may be thin enough that the incident excitation light L1 passes through and leaks out from the back surface. However, in this case, it is preferable that a reflective film capable of reflecting the incident excitation light L1 and the fluorescent light L3 with high reflectance is formed on the surface of the heat sink 50. Examples of such a reflective film include a metal film such as Ag, or a dielectric multilayer film.

[0016] Examples of the material system of the phosphor 20 include a powder material coated with one or more rare earth elements, a single crystal material with a garnet structure containing aluminum and oxygen, a eutectic material, or an inorganic compound material. The material system of the phosphor 20 may be, for example, a sintered body obtained by solidifying a powder phosphor by sintering.

[0017] When the incident excitation light L1 is incident on the light incident surface of the phosphor 20, the phosphor 20 is excited by the incident excitation light L1, and the phosphor 20 emits fluorescent light L3. The fluorescent light L3 is output to the outside as radiant light from the portion of the light incident surface of the phosphor 20 where the incident excitation light L1 is incident. The fluorescent light L3 has a distribution in which the output intensity is the largest when the emission angle (angle with respect to the normal line NL) is 0°, and the output intensity gradually decreases as the emission angle increases (FIG. 2). In order to effectively utilize the fluorescent light L3, it is preferable to suppress the decrease in the amount of fluorescence to about 50% of the value when the emission angle is 0°. Therefore, it is preferable to arrange the off-axis parabolic mirror 30 so that the component of the fluorescent light L3 whose emission angle is in the range of 0° to 60° can be utilized.

[0018] The off-axis parabolic mirror 30 is capable of combining reflected excitation light L2, which is light reflected by the light incident surface of the phosphor 20 out of the incident excitation light L1, with fluorescent light L3 emitted from the phosphor 20, and outputting the combined light thus obtained to the outside as output light L4. The off-axis parabolic mirror 30 is a parabolic mirror having a part of the parabolic mirror other than the part intersecting with the optical axis of the parabolic mirror as a reflecting mirror. This reflecting mirror is not formed by ordinary polishing, but is formed by 3D mirror grinding of metal and glass material.

[0019] In the off-axis parabolic mirror 30, when collimated light (parallel light) is incident on the reflecting mirror, the focal point is formed at a position offset from the mirror optical axis OA of the reflecting mirror. In addition, in the off-axis parabolic mirror 30, when a light source is installed at a position offset from the mirror optical axis OA of the reflecting mirror (the focal point position) and light is diverged from the light source, the light that is diverged and heads toward the reflecting mirror is incident on the reflecting mirror without being blocked by the light source, and the light reflected by the reflecting mirror becomes collimated light (parallel light) and is output to the outside. In other words, in the off-axis parabolic mirror 30, the mirror optical axis OA and the focusing axis FA are not parallel to each other.

[0020] The angle (off-axis angle θf) between the mirror optical axis OA and the focusing axis FA is greater than 0° and smaller than 180°, and is typically 90°. FIG. 1 illustrates an example in which the off-axis angle θf is 90°. Since the mirror optical axis OA and the focusing axis FA are non-parallel, the phosphor 20 is disposed at a position off the mirror optical axis OA. Since the phosphor 20 is off the mirror optical axis OA, the phosphor 20 and the heat sink 50 do not block the optical path of the output light L4. As a result, the beam shape of the output light L4 is circular.

[0021] The divergence angle of the component of the reflected excitation light L2 that is incident on the off-axis parabolic mirror 30 is θb. The divergence angle θb is equal to the collection angle θp of the light (incident excitation light L1) that is collected by the lens group 40 and incident on the phosphor 20, or is an angle that is larger than the collection angle θp by the amount of surface scattering of the phosphor 20. The divergence angle of the component of the fluorescent light L3 that is incident on the off-axis parabolic mirror 30 is θy. At this time, the divergence angle θb and the divergence angle θy are approximately equal to each other. Furthermore, at any point on the reflecting mirror of the off-axis parabolic mirror 30, the incidence angle of the reflected excitation light L2 and the incidence angle of the fluorescent light L3 are approximately equal to each other. As a result, the color of the output light L4 becomes more uniform compared to the light source device 100 according to the comparative example described later and the inventions described in the prior art documents described above. In the off-axis parabolic mirror 30, the shape and size of the reflecting mirror are set so that the divergence angle θy is a desired value (the same angle as the collection angle θp, or an angle expanded beyond the collection angle θp by the amount of surface scattering of the phosphor 20).

[0022] The lens group 40 irradiates the light emitted from the light-emitting unit 10 (incident excitation light L1) onto the light incident surface of the phosphor 20. The lens group 40 includes, for example, a lens 41 that collimates the light emitted from the light-emitting unit 10 (incident excitation light L1), and a lens 42 that collects the light (incident excitation light L1) collimated by the lens 41. The lens 42 is disposed at a position where the focal length of the lens 42 is equal to or approximately equal to the distance between the lens 42 and a portion of the phosphor 20 that is irradiated with the incident excitation light L1.

[0023] The heat sink 50 is a heat dissipation member capable of dissipating heat generated from the phosphor 20 when the phosphor 20 is irradiated with the incident excitation light L1. The heat sink 50 is made of, for example, an aluminum alloy or a copper alloy. For example, a reflective film as described above may be laminated on the surface of the heat sink 50 or the surface (rear surface) opposite to the light incident surface of the phosphor 20. The reflective film is disposed between the heat sink 50 and the phosphor 20. When a reflective film made of a metal film such as Ag is provided on the rear surface of the phosphor 20, the metal film and the heat sink 50 can be joined to each other via solder by providing a metal film such as Au or Ni on the surface of the reflective film.

[0024] FIG. 3 is a diagram showing an example of the relationship between the divergence angle θy of the component of the fluorescent light L3 incident on the off-axis parabolic mirror 30 and m when the optical focal length Lf is the mirror size Lm and the reflection focal length Lr is m times the mirror size Lm in the off-axis parabolic mirror 30 with an off-axis angle θf of 90° (hereinafter referred to as "optical condition A"). From FIG. 3, it can be seen that when m is 1 or less, the divergence angle θy approaches 90°, so there is no shape solution for the off-axis parabolic mirror 30, and it is difficult to realize the off-axis parabolic mirror 30. Therefore, it is preferable that the divergence angle θy is 70° or less, and practically, it is preferable that m is 1.5 or more and the divergence angle θy is 35° or less.

[0025] 4 is a diagram showing an example of the relationship between m and the minimum value θys of the angle between the normal NL of phosphor 20 and the component of reflected excitation light L2 that is incident on off-axis parabolic mirror 30, under optical condition A. It can be seen from Fig. 4 that when the incidence angle θi of incident excitation light L1 is set to half or less of the off-axis angle θf (for example, 45°, 35°, 25°, 15°), the minimum value θys can be reduced by reducing the incidence angle θi.

[0026] Fig. 5 is a diagram showing an example of the dependency of the integrated light amount of the fluorescent light L3 incident on the off-axis parabolic mirror 30 on the divergence angle θy when the minimum value θys is changed. As can be seen from Fig. 5, the integrated light amount of the fluorescent light L3 increases as the divergence angle θy increases and increases as the minimum value θys decreases. It can be seen that in practice, the light utilization efficiency can be improved by setting the minimum value θys to 30° or less.

[0027] FIG. 6 is a diagram showing an example of the amount of light of the fluorescent light L3 emitted from the off-axis parabolic mirror 30 when the divergence angle θy is changed, with the amount of light shown in FIG. 2 being set to 1. FIG. 7 is a diagram showing an example of the chromaticity of the fluorescent light L3 emitted from the off-axis parabolic mirror 30 when the divergence angle θy is changed. FIG. 7 shows an example of the chromaticity of the fluorescent light L3 when the amount of light of the fluorescent light L3 emitted from the off-axis parabolic mirror 30 is set to the amount of light shown in FIG. 6 (0.12, 0.22, 0.28, 0.43, 0.82). It can be seen from FIG. 6 that the amount of light of the fluorescent light L3 emitted from the off-axis parabolic mirror 30 can be changed by changing the divergence angle θy and further changing m to a value according to the change in θy, and as a result, the color of the output light L4 can be changed.

[0028] [effect] Next, the effects of the light source device 1 will be described in comparison with a light source device 100 according to a comparative example.

[0029] FIG. 8 shows a configuration example of a light source device 100 according to a comparative example. The light source device 100 includes a light emitting unit 110, a phosphor 120, a cylindrical parabolic mirror 130 with an opening, and a lens group 140. The phosphor 120 is disposed at a focal position on the axis of symmetry of the parabolic line of the parabolic mirror 130. When incident excitation light L11 is irradiated from the light emitting unit 110 to the phosphor 120 through the lens group 140 and the opening of the parabolic mirror 130, fluorescent light L13 is emitted from the phosphor 120 and reflected by the parabolic mirror 130. A part of the incident excitation light L11 is reflected by the surface of the phosphor 120, and is further reflected by the parabolic mirror 130. As a result, the fluorescent light L13 reflected by the parabolic mirror 130 and the excitation light (reflected excitation light L12) reflected by the phosphor 120 are combined, and the combined light obtained thereby is output to the outside as output light L14.

[0030] Here, the fluorescent light L13 emitted from the phosphor 120 is a light with a large spread as a divergent light from a point light source. On the other hand, the excitation light reflected by the phosphor 120 (reflected excitation light L12) has a divergence angle that is significantly smaller than the divergence angle of the fluorescent light L13. Therefore, only the part of the output light L14 where the reflected light of the fluorescent light L13 and the reflected excitation light L12 are combined becomes approximately white, and the other part of the output light L14 has the color of the reflected light of the fluorescent light L13. Therefore, the color of the output light L14 is non-uniform in a concentric circle. Furthermore, since an opening is provided in the parabolic mirror 130, the beam shape of the output light L14 is a doughnut shape. In addition, although not shown in FIG. 8, it is necessary to provide a support for supporting the phosphor 120 and a heat sink for dissipating heat emitted from the phosphor 120. Since these are disposed on the optical path of the output light L14, the output light L14 is blocked by the support body or the heat sink, and the beam shape of the output light L14 becomes non-uniform. Furthermore, if the heat sink is made small in order to reduce the proportion of the output light L14 that is blocked by the heat sink, the heat generated from the phosphor 120 cannot be sufficiently dissipated to the outside.

[0031] On the other hand, in this embodiment, the off-axis parabolic mirror 30 is irradiated with the reflected excitation light L2, which is the light reflected by the light incident surface of the phosphor 20 out of the incident excitation light L1, and the fluorescent light L3 emitted from the phosphor 20, and the combined light obtained by reflection on the off-axis parabolic mirror 30 is output to the outside as the output light L4. At this time, the phosphor 20 and the heat sink 50 are disposed at a position off the mirror optical axis OA. Since the phosphor 20 and the heat sink 50 are off the mirror optical axis OA, the phosphor 20 and the heat sink 50 do not block the optical path of the output light L4. As a result, the beam shape of the output light L4 is circular. Furthermore, the heat sink 50 can be made large enough to dissipate the heat generated from the phosphor 20 to the outside.

[0032] In addition, in the off-axis parabolic mirror 30, the divergence angle θb of the component of the reflected excitation light L2 that enters the off-axis parabolic mirror 30 and the divergence angle θy of the component of the fluorescent light L3 that enters the off-axis parabolic mirror 30 are approximately equal to each other. Furthermore, at any point on the reflecting mirror of the off-axis parabolic mirror 30, the incidence angle of the reflected excitation light L2 and the incidence angle of the fluorescent light L3 are approximately equal to each other. This makes the color of the output light L4 more uniform than that of the light source device 100 according to the comparative example and the inventions described in the prior art documents mentioned above.

[0033] From the above, in this embodiment, the beam shape of the output light L4 can be made circular, and the color of the output light L4 can be made substantially uniform. Furthermore, the heat generated from the phosphor 120 can be sufficiently dissipated to the outside.

[0034] In this embodiment, when adjusting the color of the output light L4, for example, the divergence angle θb (or the collection angle θp) is adjusted by adjusting the positions of the lenses 41, 42 in the lens group 40, and further, the reflection focal length Lr of the off-axis parabolic mirror 30 is adjusted by replacing the off-axis parabolic mirror 30, and the phosphor 20 is disposed at the position of the reflection focal length Lr after the adjustment. In this way, in this embodiment, the color of the output light L4 can be adjusted by simply mechanically adjusting the light source device 1 or replacing a part (for example, the off-axis parabolic mirror 30) in the light source device 1. Therefore, the color of the output light L4 can be adjusted by a simple adjustment.

[0035] In addition, in this embodiment, the converging angle θp of the incident excitation light L1 by the lens group 40, or the divergence angle θb of the incident excitation light L1 reflected by the light incident surface of the phosphor 20, and the divergence angle θy of the component of the fluorescent light L3 that is incident on the off-axis parabolic mirror 30 are approximately equal to each other. This makes the color of the output light L4 more uniform than that of the light source device 100 according to the comparative example or the inventions described in the above-mentioned prior art documents. As a result, the color of the output light L4 can be made approximately uniform.

[0036] In addition, in this embodiment, the divergence angle θb of the component of the reflected excitation light L2 that is incident on the off-axis parabolic mirror 30 is set to 35° or less. This allows the off-axis parabolic mirror 30 to have a realistic shape in terms of the difficulty of manufacturing, etc. Furthermore, by setting the divergence angle θb to 35° or less, as shown in FIG. 3, the change in m with respect to the change in the divergence angle θb becomes gentle, so that the sensitivity of the error in the focal position FP to the error in the divergence angle θb can be reduced. This allows the difficulty of procuring parts and assembling to be reduced.

[0037] In addition, in this embodiment, the angle θi between the optical axis EA of the incident excitation light L1 and the normal NL of the phosphor 20 is 45° or less. This allows the incident angle θi of the incident excitation light L1 to be half or less of the off-axis angle θf (for example, 45°, 35°, 25°, 15°), and by reducing the incident angle θi, the minimum value θys can be reduced. By reducing the minimum value θys, the integrated light amount of the fluorescent light L3 incident on the off-axis parabolic mirror 30 can be increased, and the light utilization efficiency can be improved.

[0038] In this embodiment, the minimum angle θys between the normal NL of the phosphor L3 and the component of the reflected excitation light L2 that is incident on the off-axis parabolic mirror 30 is set to 30° or less. This makes it possible to increase the integrated light amount of the fluorescent light L3 that is incident on the off-axis parabolic mirror 30, thereby improving the light utilization efficiency.

[0039] <2. Modifications> Below, modified examples of the light source device 1 will be described. In the following, components common to the above embodiment will be denoted by the same reference numerals as those in the above embodiment. Also, components different from the above embodiment will be mainly described, and descriptions of components common to the above embodiment will be omitted as appropriate.

[0040] [Variation A] 9, the position adjustment units 60, 70 may be set so that the angle θi between the optical axis EA of the incident excitation light L1 and the normal NL of the phosphor 20 is less than 45° (e.g., 35°, 25°, 15°). This makes it possible to increase the integrated light amount of the fluorescent light L3 incident on the off-axis parabolic mirror 30, thereby improving the light utilization efficiency.

[0041] [Variation B] In the above embodiment, for example, as shown in FIG. 10, light-emitting units 10r, 10g, and 10b, lens groups 40r, 40g, and 40b, optical fibers 80r, 80g, and 80b, an optical combiner 80, and an optical fiber 80m may be provided instead of the light-emitting unit 10.

[0042] The light-emitting unit 10r includes a semiconductor laser capable of emitting light Lr (e.g., red light) having a wavelength within the visible wavelength range. The light-emitting unit 10g includes a semiconductor laser capable of emitting light Lg (e.g., green light) having a wavelength within the visible wavelength range. The light-emitting unit 10b includes a semiconductor laser capable of emitting light Lb (e.g., blue light) having a wavelength within the visible wavelength range as light (incident excitation light) capable of exciting the phosphor 20.

[0043] Light Lr emitted from the light-emitting unit 10r propagates along the optical axis EAr of the lens group 40r and is irradiated onto the end of the optical fiber 80r. Light Lg emitted from the light-emitting unit 10g propagates along the optical axis EAg of the lens group 40g and is irradiated onto the end of the optical fiber 80g. Light Lb emitted from the light-emitting unit 10b propagates along the optical axis EAb of the lens group 40b and is irradiated onto the end of the optical fiber 80b. The lens groups 40r, 40g, and 40b are each configured to include, for example, lenses 41 and 42, respectively.

[0044] The optical fiber 80r is connected to the light emitting unit 10r and the optical combiner 80, and is capable of propagating the light emitted from the light emitting unit 10r to the optical combiner 80. The optical fiber 80g is connected to the light emitting unit 10g and the optical combiner 80, and is capable of propagating the light emitted from the light emitting unit 10g to the optical combiner 80. The optical fiber 80b is connected to the light emitting unit 10b and the optical combiner 80, and is capable of propagating the light emitted from the light emitting unit 10b to the optical combiner 80.

[0045] The optical combiner 80 has optical fibers 80r, 80g, and 80b connected to an input port, and an optical fiber 80m connected to an output port. The optical combiner 80 can combine the light of the light-emitting unit 10r input from the optical fiber 80r, the light of the light-emitting unit 10g input from the optical fiber 80g, and the light of the light-emitting unit 10b input from the optical fiber 80b, and output the light (combined light Lm) obtained thereby to the optical fiber 80m. The light (combined light Lm) propagated through the optical fiber 80m propagates on the optical axis EAm of the lens group 40, and is irradiated onto the surface of the phosphor 20. The position of the optical axis EAm of the lens group 40 is adjusted by a position adjustment unit 90 provided in place of the position adjustment unit 60.

[0046] In this manner, in this modification, a composite light Lm including light Lb capable of exciting the phosphor 20 and light Lr, Lg that does not function as excitation light is irradiated onto the surface of the phosphor 20. This makes it possible to obtain an output light L4 with a chromaticity according to the intensities of the light Lr, Lg. Therefore, by adjusting the intensities of the light Lr, Lg, a colorful light source can be realized.

[0047] In this modification, for example, a reflecting mirror or a diffusing plate may be disposed instead of the phosphor 20. In this case, by adjusting the composite ratio of the lights Lr, Lg, and Lb emitted from the light-emitting units 10r, 10g, and 10b, a colorful light source can be realized without using the fluorescent light L3.

[0048] The present invention can be applied to various fields such as laser displays (laser projectors, laser TVs, head mounted displays, etc.), laser lighting (microscopes, headlamps, indoor indirect lighting, plant factories, etc.), projection mapping, and medicine (laser scalpels, etc.). [Explanation of symbols]

[0049] 1...light source device, 10, 10r, 10g, 10b...light emitting section, 20...phosphor, 30...off-axis parabolic mirror, 40...lens group, 41, 42...lens, 50...heat sink, 60, 70, 80...position adjustment section, 100...light source device, 110...light emitting section, 120...phosphor, 130...parabolic mirror, 140...lens group, EA...optical axis, FA...focus axis, FP...focus position, NL...normal, L1, L11...incident excitation light, L2, L12...reflected excitation light, L3, L13...fluorescent light, L4, L14...output light, Lf...optical focal length, Lm...mirror size, Lr...reflection focal length, OA...mirror optical axis, θb, θy...divergence angle, θf...off-axis angle, θi...incident angle, θp...focus angle, θys...minimum value.

Claims

1. A phosphor; a light source unit capable of irradiating an incident excitation light, which is an excitation light capable of exciting the phosphor, onto a light incident surface of the phosphor; an off-axis parabolic mirror capable of combining reflected excitation light, which is light of the incident excitation light reflected by the light incident surface, with fluorescent light emitted from the phosphor, and outputting the combined light thus obtained to the outside as output light; Equipped with Light source device.

2. The divergence angle of the component of the reflected excitation light incident on the off-axis parabolic mirror and the divergence angle of the component of the fluorescent light incident on the off-axis parabolic mirror are substantially equal to each other. The light source device according to claim 1 .

3. the light source unit includes a light emitting unit capable of emitting the incident excitation light, and a lens group that collects the incident excitation light and irradiates the light incident surface, The angle of convergence of the incident excitation light by the lens group, or the angle of divergence of the light reflected by the light incident surface, and the angle of divergence of the component of the fluorescent light that is incident on the off-axis parabolic mirror are approximately equal to each other. The light source device according to claim 1 .

4. The divergence angle of the component of the reflected excitation light incident on the off-axis parabolic mirror is 35° or less. The light source device according to claim 1 .

5. The angle between the optical axis of the incident excitation light and the normal to the phosphor is 45° or less. The light source device according to claim 1 .

6. The light source unit includes: a first light source capable of emitting red light; a second light source capable of emitting green light; a third light source capable of emitting the blue light as the incident excitation light; an optical system capable of synthesizing the red light, the green light, and the blue light and irradiating the phosphor with the light obtained as the incident excitation light; have The light source device according to claim 1 .

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