Light source device

Abstract

This light source device is provided with: a reflection member having a plurality of reflection surfaces that include a first reflection surface and a second reflection surface, and one or more transmission surfaces that include a first transmission surface connecting between the first reflection surface and the second reflection surface; a plurality of light-emitting elements including a first light-emitting element for emitting first light that travels in a direction where the reflection member is disposed and that enters the first reflection surface and a second light-emitting element for emitting second light that travels in the direction where the reflection member is disposed and that enters the second reflection surface; and a first light detector having disposed thereon a first light reception surface that is irradiated with the first light travelling in the direction where the reflection member is disposed and passing through the first transmission surface.

Description

[Technical field]

[0001] The present disclosure relates to a light source device. [Background technology]

[0002] Patent Document 1 discloses a light source device including a plurality of light sources, a step mirror having a step-like reflecting surface that reflects light from the plurality of light sources, and a lens unit that collects the reflected light. The invention disclosed in Patent Document 1 aims to provide a simple and inexpensive light source device including a step mirror. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication 2016-18594 Summary of the Invention [Problem to be solved by the invention]

[0004] A light source device capable of detecting the output state of light emitted from a plurality of light sources. [Means for solving the problem]

[0005] The light source device in the embodiment includes a reflective member having a plurality of reflective surfaces including a first reflective surface and a second reflective surface, and one or a plurality of transparent surfaces including a first transparent surface connecting the first reflective surface and the second reflective surface, a plurality of light-emitting elements including a first light-emitting element that travels in the direction in which the reflective member is arranged and emits a first light that is incident on the first reflective surface, and a second light-emitting element that travels in the direction in which the reflective member is arranged and emits a second light that is incident on the second reflective surface, and a first photodetector that travels in the direction in which the reflective member is arranged and has a first light-receiving surface onto which the first light that has transmitted through the first transparent surface is irradiated.

[0006] According to the embodiment of the present disclosure, a light source device capable of detecting the light output state can be realized. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a light source device according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram illustrating components disposed inside a housing of the light source device according to the embodiment, and an optical path of emitted light. [Diagram 3] FIG. 3 is an enlarged view for explaining the optical action of the reflective member in the light source device according to the embodiment. [Figure 4] FIG. 4 is a schematic diagram illustrating the optical path of return light inside the housing of the light source device according to the embodiment. [Diagram 5] FIG. 5 is a perspective view of a reflecting member according to the embodiment. [Figure 6] FIG. 6 is a perspective view of the light emitting device according to the embodiment. [Figure 7] FIG. 7 is a perspective view for explaining each component disposed inside the package of the light emitting device according to the embodiment. [Figure 8] FIG. 8 is a top view of the light emitting device according to the embodiment. [Figure 9] FIG. 9 is a top view for explaining components disposed inside the package of the light emitting device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In this specification and claims, polygons such as triangles and quadrangles are referred to as polygons, including shapes in which the corners of the polygons have been processed by rounding, chamfering, removing corners, rounding, etc. Furthermore, shapes in which processing has been applied not only to the corners (edges of the sides) but also to the middle parts of the sides are also referred to as polygons. In other words, shapes in which partial processing has been applied while leaving the polygon as the base are included in the interpretation of "polygon" described in this specification and claims.

[0009] This is not limited to polygons, but also applies to words expressing specific shapes such as trapezoids, circles, and irregular shapes. The same is true when dealing with each side that forms the shape. In other words, even if the corners or middle part of a side have been processed, the interpretation of "side" includes the processed part. Note that when distinguishing a "polygon" or "side" that has no processing from a processed shape, the word "strict" is added, for example, "strict quadrangle."

[0010] In addition, in this specification or claims, when there are multiple elements identified by a certain name and each element is to be expressed separately, an ordinal number such as "first" or "second" may be added to the beginning of each element. In addition, when an element with the same ordinal number appears in both this specification and the claims, it may not refer to the same element between the specification and the claims.

[0011] For example, when there are three elements in the specification that are distinguished by the notation "first," "second," and "third," and the claims are written with only the two elements "first" and "third" in the specification in mind, these two elements may be distinguished in the claims by the notation "first" and "second." In this case, the element marked "first" in the claims is one of the elements marked "first" or "third" in the specification, and the element marked "second" in the claims is the other of the elements marked "first" or "third" in the specification in this specification.

[0012] Furthermore, in this specification or claims, terms indicating a specific direction or position (e.g., "upper", "lower", "right", "left", "front", "rear" and other terms including these terms) may be used. These terms are used merely for the purpose of making it easier to understand the relative direction or position in the referenced drawings. As long as the relationship of the relative direction or position by terms such as "upper" and "lower" in the referenced drawings is the same, the arrangement in drawings other than this disclosure, actual products, manufacturing equipment, etc. may not be the same as in the referenced drawings.

[0013] Hereinafter, the embodiments for carrying out the present invention will be described with reference to the drawings. However, although the embodiments shown embody the technical ideas of the present invention, they do not limit the present invention. In the following description, the same names and symbols indicate the same or similar components, and duplicated descriptions may be omitted as appropriate. Note that the sizes and positional relationships of the components shown in each drawing may be exaggerated for ease of understanding.

[0014] <Embodiment> A light source device 1 according to an embodiment will be described. FIGS. 1 to 9 are diagrams for explaining an exemplary embodiment of the light source device 1. FIG. 1 is a perspective view of the light source device 1. FIG. 2 is a schematic diagram for explaining a plurality of components arranged in the internal space of the housing 10 of the light source device 1. Moreover, the hatched area indicates the light emitted from the light emitting device 20. FIG. 3 is an enlarged view of the portion of the reflecting member 30 with respect to the optical action of the emitted light shown in FIG. 2. FIG. 4 is a schematic diagram for explaining the optical path of the return light in the internal space of the housing 10. Moreover, the hatched area indicates the return light.

[0015] Fig. 5 is a perspective view of the reflective member 30. Fig. 6 is a perspective view of the light emitting device 20. Fig. 7 is a perspective view for explaining one or more components disposed in the internal space of the package 21 of the light emitting device 20. Fig. 8 is a top view of the light emitting device 20. The hatched area indicates light emitted from the light emitting device 20. Fig. 9 is a top view of the perspective view of Fig. 7 as seen from above.

[0016] The light source device 1 includes a plurality of components including a housing 10, one or more light emitting devices 20, a reflecting member 30, a condenser lens 40, one or more photodetectors 50, and an optical fiber 60. Note that the light source device 1 may further include components different from these, or may further include the same components.

[0017] First, each component will be described. (Chassis 10) The housing 10 has a bottom surface, one or more side surfaces, and a top surface located above the bottom surface. The housing 10 also defines an internal space surrounded by the bottom surface, one or more side surfaces, and the top surface. Other components can be placed in this internal space.

[0018] Moreover, the housing 10 has one or more openings 11 formed therein. For example, the opening 11 is formed on the top surface of the housing 10. Furthermore, for example, the opening 11 is formed on the side surface of the housing 10. In the light source device 1 shown in the figure, the openings 11 are formed on both the top surface and the side surface of the housing 10. Furthermore, the housing 10 has an exit port 12 formed therein, which emits main light to the outside of the housing 10. For example, the exit port 12 is formed on the side surface of the housing 10.

[0019] Moreover, the opening 11 provided on the top surface is formed at a position closer to the opposite side surface than the side surface on which the emission port 12 is formed. Moreover, the emission port 12 can be formed on the side surface on the opposite side to the side surface on which the opening 11 is formed. Moreover, the opening 11 and the emission port 12 formed on the side surface are each provided at a position where an imaginary straight line parallel to the bottom surface of the housing 10 passes through them.

[0020] (Light emitting device 20) The light emitting device 20 includes a plurality of components including a package 21, one or more light emitting elements 22, one or more submounts 23, one or more reflecting members 24, and one or more collimating lenses 25. Although they can also be distinguished by their symbols, for convenience, the reflecting member 30 will be referred to as the first reflecting member 30 and the reflecting member 24 as the second reflecting member 24.

[0021] A sealed space is formed inside the package 21 in which other components of the light emitting device 20 are disposed. The package 21 can be composed of, for example, a base portion forming a recess and a lid portion that covers the recess. One or more light emitting elements 22 are disposed in the sealed space formed inside the package 21. Furthermore, one or more second reflecting members 24 may be disposed. Furthermore, the one or more light emitting elements 22 may be mounted on one or more submounts 23.

[0022] The light emitting element 22 is a semiconductor laser element. The light emitting element 22 is not limited to a semiconductor laser element, and may be a light emitting diode or the like. When the light emitting element 22 is a semiconductor laser element, the space inside the package 21 can be sealed in an airtight state. This makes it possible to suppress deterioration of the quality of light due to dust collection.

[0023] The light emitting element 22 is disposed on the bottom surface of the package 21 and emits light laterally. Therefore, the light emission surface of the light emitting element 22 is located on a side surface. The light emission surface may be located on the top surface so that light is emitted upward. Furthermore, light emission surfaces may be provided on multiple surfaces.

[0024] The light emitting element 22 is arranged so that the surface with the largest area is located on the upper or lower surface. When the light emitting element 22 is a semiconductor laser element, it can be arranged in this manner by providing an emission surface on the side surface. This makes it easier for heat generated from the light emitting element 22 to be dissipated through the package 21. In addition, by sandwiching the submount 23, the heat dissipation can be further improved.

[0025] The light emitted from the emission surface of the light emitting element 22 is irradiated onto the reflection surface of the second reflection member 24. The light reflected by the second reflection member 24 travels upward and is emitted to the outside of the package 21. The light emitted to the outside of the package 21 passes through the collimating lens 25 and becomes collimated light, which is emitted to the outside of the light emitting device 20.

[0026] One or more collimating lenses 25 are disposed above the package 21. Also, the collimating lenses 25 are fixed to the package 21. The collimating lenses 25 have a lens surface for converting incident light into collimated light. One lens surface is designed to collimate light from one light-emitting element 22. When the collimating lenses 25 collimate light from multiple light-emitting elements 22, the lens surfaces are also multiple. Note that the light-emitting device 20 does not need to include the collimating lenses 25. For example, the collimating lenses 25 may be provided in the light source device 1 as a component separate from the light-emitting device 20, rather than as a component of the light-emitting device 20.

[0027] The illustrated light emitting device 20 is an example of a configuration including a plurality of light emitting elements 22, a plurality of submounts 23, a plurality of second reflecting members 24, and one collimating lens 25. The plurality of light emitting elements 22 are arranged side by side, and the plurality of second reflecting members 24 are also arranged side by side in the same direction as the direction in which the plurality of light emitting elements 22 are arranged. Similarly, the plurality of lens surfaces of the collimating lens 25 are also arranged side by side in the same direction. As a result, a plurality of collimated lights are emitted side by side from the light emitting device 20.

[0028] (Light emitting element 22) Here, a supplementary explanation will be given regarding a semiconductor laser element, which is an example of the light emitting element 22. Light (laser light) emitted from a semiconductor laser element has a spread, and forms an elliptical far-field pattern (hereinafter referred to as "FFP") on a plane parallel to the light emission end face. The FFP refers to the shape and light intensity distribution of the emitted light at a position away from the emission end face.

[0029] Here, the light passing through the center of the elliptical shape of the FFP, in other words, the light with the peak intensity in the light intensity distribution of the FFP, is referred to as the light traveling along the optical axis. Also, the optical path of the light traveling along the optical axis is referred to as the optical axis of that light. Also, in the light intensity distribution of the FFP, the light with a 1 / e 2 The light having an intensity equal to or greater than this will be referred to as the main portion of the light.

[0030] In the elliptical shape of the FFP of light emitted from a semiconductor laser element, the minor axis direction of the ellipse is called the slow axis direction of the FFP, and the major axis direction is called the fast axis direction of the FFP. The multiple layers, including the active layer, that make up the semiconductor laser element are stacked in the fast axis direction of the FFP.

[0031] Based on the light intensity distribution of the FFP, the angle corresponding to the main part of the light is called the light divergence angle of the semiconductor laser element. In an elliptical FFP, the divergence angle of the light in the fast axis direction is larger than the divergence angle of the light in the slow axis direction.

[0032] (First reflecting member 30) The first reflecting member 30 has a plurality of reflecting surfaces 31. The plurality of reflecting surfaces 31 are not on the same plane and are parallel to each other. The plurality of reflecting surfaces 31 are provided on the same surface side of the first reflecting member 30. The plurality of reflecting surfaces 31 are provided at positions that do not overlap each other in a plan view seen from a direction perpendicular to a plane parallel to the reflecting surfaces 31. The plurality of reflecting surfaces 31 may partially overlap each other.

[0033] The first reflecting member 30 has a stepped outer shape, and each successive step forms a reflecting surface 31. The first reflecting member 30 also has a transmitting surface 32 continuing from the reflecting surface 31. The first reflecting member 30 has one or more transmitting surfaces 32 formed thereon.

[0034] In the stepped portion of the first reflecting member 30, a plurality of reflecting surfaces 31 and one or more transmitting surfaces 32 are alternately provided. The one or more transmitting surfaces 32 include a transmitting surface 32 connecting two reflecting surfaces 31. This transmitting surface 32 is continuous with both of the two reflecting surfaces 31. Furthermore, the first reflecting member 30 has a plurality of transmitting surfaces 32, and the plurality of transmitting surfaces 32 may include a transmitting surface 32 that is continuous with the reflecting surface 31 on the same plane as the reflecting surface 31.

[0035] Here, the multiple flat surfaces that form the steps in a staircase pattern in the first reflecting member 30 are referred to as step surfaces. It can be said that the first reflecting member 30 includes multiple step surfaces that form the steps. If one of the consecutive steps is the lower step and the other is the upper step, the multiple step surfaces include at least the top surface of the lower step, the top surface of the upper step, and side surfaces that intersect with both top surfaces.

[0036] Here, the upper surface of the step surface is referred to as the step upper surface 33, and the side surface is referred to as the step side surface 34. To form a step-like step, two or more step upper surfaces 33 and one or more step side surfaces 34 are required. The step side surface 34 intersects with both step upper surfaces 33 of consecutive steps. Furthermore, the step upper surface 33 and the step side surface 34 intersect perpendicularly to each other. Note that the perpendicular here includes a difference of within ±2 degrees.

[0037] The first reflecting member 30 has a bottom surface located opposite the step top surface 33. The multiple step surfaces form a staircase shape with the bottom surface as a reference. The first reflecting member 30 also has an outer surface that intersects with the step top surface 33 on the opposite side of the step side surface 34 that intersects with the step top surface 33 of the uppermost step, and an outer surface that intersects with the step top surface 33 on the opposite side of the step side surface 34 that intersects with the step top surface 33 of the lowermost step. The multiple step surfaces are between these two outer surfaces.

[0038] A plurality of reflecting surfaces 31 are provided on a plurality of step upper surfaces 33. A reflecting surface 31 is provided on each of the step upper surfaces 33 of successive steps. In addition, each step side surface 34 serves as a transmitting surface 32 that transmits light. For example, a first reflecting member 30 having a reflecting surface 31 and a transmitting surface 32 can be produced by providing a reflecting surface 31 on a portion of the entire surface of a light-transmitting base material that forms the general shape (main shape). For example, the reflecting film 31 is formed by a dielectric multilayer film. The reflecting surface 31 is formed on a portion or all of the step upper surface 33. The transmitting surface 32 is formed on a portion or all of the step side surface 34.

[0039] The reflectance of the reflecting surface 31 is 90% or more for light of a specific wavelength. Preferably, the reflectance is 95% or more. More preferably, the reflectance is 99% or more. When the light reflected by the reflecting surface 31 is the main emitted light of the light source device 1, a higher reflectance allows more light to be captured. On the other hand, when transmitted light is required in addition to the light passing through the transmitting surface 32, the reflectance of the reflecting surface 31 can be reduced to utilize the light passing through the reflecting surface. The reflectance of the reflecting surface 31 is preferably high, but it may be set appropriately in consideration of the balance of the light to be used as transmitted light, and the above-mentioned numerical conditions of the reflectance are at least considered to be useful.

[0040] The transmittance of the transmitting surface 32 for light of the same specific wavelength is greater than the transmittance of the reflecting surface 31. As a specific example, the transmittance of the transmitting surface 32 for light of the same specific wavelength is greater than the transmittance of the reflecting surface 31 by 20% or more. Moreover, the transmittance of the transmitting surface 32 for light of the same specific wavelength may be 50% or more.

[0041] In the process of providing the reflective surface 31 on the step top surface 33, it is considered that part of the material used to form the reflective surface 31 may also be formed on the step side surface 34. Even in such a case, the step side surface 34 of the first reflective member 30 does not have a reflective surface having reflectance characteristics equivalent to that of the reflective surface 31 on the step top surface 33, and can transmit more light than the reflective surface 31. In other words, it can be said that the first reflective member 30 can transmit more light than a reflective member of the same external shape in which the reflective surface 31 is provided entirely on the step top surface 33 and the step side surface 34.

[0042] Here, the direction in which the step is formed is referred to as the step direction. For example, the step direction at the step top surface 33 is the direction that reaches the step side surface 34 intersecting with this step top surface 33 in the shortest distance. The step direction at the step side surface 34 is the direction that reaches the step top surface 33 intersecting with this step side surface 34 in the shortest distance. In the illustrated example of the light source device 1, the direction perpendicular to the intersection line between the step top surface 33 and the step side surface 34 on a plane parallel to the step top surface 33 is the step direction at the step top surface 33, and the direction perpendicular to the intersection line between the step top surface 33 and the step side surface 34 on a plane parallel to the step side surface 34 is the step direction at the step top surface 34.

[0043] The length of the reflecting surface 31 in the step direction is greater than the length of the transmitting surface 32 in the step direction. The length of the transmitting surface 32 in the step direction is ⅓ or less of the length of the reflecting surface 31 in the step direction. Furthermore, the length of the step top surface 33 in the step direction is greater than the length of the step side surface 34 that intersects with this step top surface 33 in the step direction. The length of the step top surface 33 in the step direction is three times or more the length of the step side surface 34 that intersects with this step top surface 33 in the step direction.

[0044] (Condenser lens 40) The condenser lens 40 is a lens for collecting incident light to a predetermined point or area, and is, for example, a plano-convex lens.

[0045] (Photodetector 50) The photodetector 50 has a light receiving surface that receives light. The light receiving surface is provided on the surface of the photodetector 50. The photodetector 50 is a photoelectric conversion element that outputs an electrical signal according to the intensity or amount of light incident on the light receiving surface. The photodetector 50 is, for example, a photodiode.

[0046] (Optical fiber 60) The optical fiber 60 has a fiber connecting an input port and an output port. Light incident from the input port propagates inside the fiber and is output from the output port. The optical fiber 60 has a core diameter at the input port of, for example, 400 μm or less. It is also preferable that the core diameter at the input port is 200 μm or less. If the core diameter can be reduced, the entire composite device including the light source device 1 and other devices connected to the light source device 1 can be made smaller.

[0047] (Light source device 1) Next, the light source device 1 will be described. In the light source device 1, one or more light emitting devices 20 are arranged in the internal space of the housing 10. The light emitting devices 20 are arranged on the bottom surface of the housing 10. The light emitting devices 20 are arranged so that the collimating lenses 25 face the upper surface side of the housing 10. The light emitting devices 20 emit light upward. The collimated light is emitted upward.

[0048] The light emitted from one or more light emitting devices 20 includes light emitted from a plurality of light emitting elements 22. The light emitted from the plurality of light emitting elements 22 is emitted upward with its optical axes parallel to each other. Note that "parallel" here includes a difference of within ±2 degrees. The light emitted from the plurality of light emitting elements 22 is also emitted upward while aligned in the slow axis direction.

[0049] In top view, the opening 11 provided on the top surface of the housing 10 includes at least a portion of the one or more light emitting devices 20. In side view, the opening 11 provided on the side surface of the housing 10 does not include the one or more light emitting devices 20. In other words, the one or more light emitting devices 20 are disposed at a lower position than the opening 11 provided on the side surface of the housing 10. In other words, the opening 11 provided on the side surface of the housing 10 is formed at a higher position than the one or more light emitting devices 20.

[0050] In the light source device 1, a first reflecting member 30 is disposed in the internal space of the housing 10. The first reflecting member 30 is disposed above one or more light emitting devices 20. Light emitted from the light emitting device 20 travels in the direction in which the first reflecting member 30 is disposed. The light emitted from the light emitting device 20 is reflected by a reflecting surface 31 of the first reflecting member 30. In addition, a part of the light emitted from the light emitting device 20 transmits through a transmitting surface 32 of the first reflecting member 30.

[0051] In the light source device 1, the reflectance conditions at the reflecting surface 31 of the first reflecting member 30 and the transmittance conditions at the transmitting surface 32 described above hold true for the light emitted from the light-emitting element 22, or for the light having a peak wavelength among the light emitted from the light-emitting element 22, as light of a specific wavelength.

[0052] In the light source device 1, a plurality of light beams emitted from a plurality of light-emitting elements 22 are irradiated onto a plurality of reflective surfaces 31 and are reflected by the plurality of reflective surfaces 31. The plurality of light-emitting elements 22 includes one or more light-emitting elements 22 whose emitted light is incident on the reflective surface 31 and the transmitting surface 32. The light beams emitted from each of the plurality of light-emitting elements 22 and traveling along the optical axis are irradiated onto different reflective surfaces 31.

[0053] The first reflecting member 30 is disposed so that the reflecting surface 31 is inclined obliquely with respect to the optical axis of the light traveling toward the reflecting surface 31. The light reflected by the reflecting surface 31 travels in a direction toward the side surface on which the exit port 12 is formed.

[0054] The distance between the optical axes of the light emitted from the multiple light-emitting elements 22 is shorter at the point where the light reflected by the first reflecting member 30 travels than at the point where the light travels in the direction in which the first reflecting member 30 is disposed. In other words, the optical axes of the light can be brought closer together by being reflected by the stepped first reflecting member 30. This allows the light from the multiple light-emitting elements 22 to be concentrated in a smaller area. From this viewpoint, it is preferable that the length of the step side surface 34 in the step direction is small, and it is also preferable that the length of the transmission surface 32 in the step direction is smaller than the length of the reflection surface 31 in the step direction.

[0055] The light irradiated to the transmitting surface 32 passes through the transmitting surface 32 and is emitted from the bottom surface of the first reflecting member 30. The light emitted from the bottom surface of the first reflecting member 30 travels upward. Note that the light may also include light emitted from the outer surface of the first reflecting member 30.

[0056] The number of step-like steps in the first reflecting member 30 is one less than the number of reflecting surfaces 31 of the first reflecting member 30 onto which light emitted from one or more light-emitting elements 22 is irradiated. In addition, the number of reflecting surfaces 31 in the first reflecting member 30 is the same as the number of light-emitting elements 22 that emit light to be irradiated onto the reflecting surfaces 31 of the first reflecting member 30.

[0057] In the illustrated example of light source device 1, all light emitted from one or more light emitting devices 20 is incident on the reflecting surface 31 and the transmitting surface 32 of the first reflecting member 30. The reflecting surface 31 is inclined at 45 degrees with respect to the optical axis of the light traveling toward the reflecting surface 31. The first reflecting member 30 has four steps, each of which is provided with a reflecting surface 31.

[0058] In the light source device 1, the photodetector 50 is disposed further above the first reflecting member 30. The photodetector 50 is disposed on the upper surface of the housing 10, for example, so as to cover the opening 11 provided on the upper surface of the housing 10.

[0059] Furthermore, in the light source device 1, another photodetector 50 is disposed on the side of the first reflecting member 30. This photodetector 50 is disposed on the side of the housing 10, for example, so as to cover the opening 11 provided on the side of the housing 10. Note that the light source device 1 may have the photodetector 50 disposed only above or only to the side of the first reflecting member 30.

[0060] Here, in order to distinguish between these photodetectors 50, the photodetector 50 located further above the first reflecting member 30 will be referred to as the first photodetector 51, and the photodetector 50 located on the side of the housing 10 will be referred to as the second photodetector 52.

[0061] The first photodetector 51 is provided at a position where the light emitted from the light emitting element 22 passes through the first reflecting member 30 and reaches the light receiving surface of the first photodetector 51. The first photodetector 51 is also provided at a position where a virtual straight line passing through the optical axis of the light emitted from the light emitting element 22 and proceeding in the direction in which the first reflecting member 30 is disposed passes. The second photodetector 52 is provided at a position where this straight line does not pass.

[0062] The second photodetector 52 is provided at a position where return light, which will be described later, passes through the first reflecting member 30 and reaches the light receiving surface of the first photodetector 51. The second photodetector 52 is provided at a position where a virtual straight line passing through the optical axis of the light emitted from the light emitting element 22 and reflected by the first reflecting member 30 passes. The first photodetector 51 is provided at a position where it does not pass through this straight line.

[0063] The light receiving surface of the first photodetector 51 is irradiated with light that is emitted upward from one or more light emitting devices 20, travels in the direction in which the first reflecting member 30 is disposed, and transmits through the transmitting surface 32. The light receiving surface of the first photodetector 51 is also irradiated with light that is emitted from the multiple light emitting elements 22 and transmits through the transmitting surface 32. This light is detected by the light receiving surface of the first photodetector 51, so that the output state of the light emitted from the light emitting device 20 or the light emitting element 22 can be detected. For example, it can be quickly known that the output of the light emitted from the light source device 1 has decreased due to a failure of some of the multiple light emitting elements 22.

[0064] In the light source device 1, a condensing lens 40 is disposed in the internal space of the housing 10. The condensing lens 40 is disposed to the side of the first reflecting member 30. The condensing lens 40 is also disposed between the first reflecting member 30 and the light outlet 12. A plurality of light beams emitted from the plurality of light-emitting elements 22 and reflected by the first reflecting member 30 pass through the condensing lens 40 and are condensed toward the light outlet 12.

[0065] In the light source device 1, the optical fiber 60 is disposed to the side of the condenser lens 40. The optical fiber 60 is attached, for example, to the exit port 12 of the housing 10. A plurality of light beams reflected by the first reflecting member 30 and passing through the condenser lens 40 enter the optical fiber 60. In addition, the light entering the entrance port of the optical fiber 60 propagates within the fiber and is emitted from the exit port.

[0066] For example, light emitted from the exit of the optical fiber 60 enters the wavelength conversion member 70, and light having a wavelength converted by the wavelength conversion member 70 is emitted. As illustrated in FIG. 4, the wavelength conversion member 70 can be connected to the optical fiber 60 and be one of the components of the light source device 1. In this case, a part of the wavelength-converted light may enter the exit of the optical fiber 60 and be emitted from the entrance of the optical fiber 60 into the internal space of the housing 10. Here, the light entering the internal space from the outside of the housing 10 as illustrated is referred to as return light.

[0067] In the light source device 1, the second photodetector 52 can receive this return light. In this case, for example, the reflecting surface 31 of the first reflecting member 30 reflects the light emitted from the light emitting element 22, while transmitting the wavelength-converted light. With such a reflecting surface 31, the return light incident on the first reflecting member 30 passes through the reflecting surface 31 and the transmitting surface 32. At least a part of the return light that has passed through the reflecting surface 31 and the transmitting surface 32 is irradiated onto the light receiving surface of the second photodetector 52. This light is detected by the light receiving surface of the second photodetector 52, so that the output state of the light that has been wavelength-converted by the wavelength conversion member 70 can be detected. For example, a decrease in the received light can be quickly detected to indicate that the wavelength conversion member 70 is no longer functioning sufficiently due to damage or the like. In addition, the opening 11 provided on the side surface of the housing 10 is formed at a position higher than one or more light emitting devices 20, so that the return light can be received more effectively.

[0068] For example, each of the light emitting elements 22 can emit blue light, and white light can be emitted by mixing the blue light with the light whose wavelength has been converted by the wavelength conversion member 70. When it is desired to emit such a mixed color, the balance between the light emitted by the light emitting elements 22 and the wavelength converted light can be an important factor in maintaining quality. In the illustrated example of the light source device 1, it is possible to use the device not only to detect whether the light emitting elements 22 or the wavelength conversion member 70 are broken or damaged, but also to adjust the light quantity balance with high accuracy.

[0069] The blue light is defined as light having a peak emission wavelength in the range of 420 nm to 494 nm. A light emitting element that emits blue light includes a light emitting element that includes a nitride semiconductor. Examples of the nitride semiconductor that can be used include GaN, InGaN, and AlGaN.

[0070] Here, the optical action of light will be described based on two light-emitting elements 22 included in the plurality of light-emitting elements 22 provided in the light source device 1. Here, the two light-emitting elements 22 are referred to as a first light-emitting element and a second light-emitting element, respectively.

[0071] The multiple reflecting surfaces 31 of the first reflecting member 30 include a first reflecting surface onto which the light (first light) emitted from the first light-emitting element is incident, and a second reflecting surface onto which the light (second light) emitted from the second light-emitting element is incident. The first reflecting surface and the second reflecting surface can be reflecting surfaces provided on step upper surfaces 33 of successive steps, respectively.

[0072] The first reflecting member 30 has a first reflecting surface, a second reflecting surface, and a transmitting surface 32 (hereinafter referred to as a first transmitting surface) connecting the first reflecting surface and the second reflecting surface. At least the first light of the first light or the second light is transmitted through the first transmitting surface and is irradiated onto the light receiving surface of the first photodetector 51.

[0073] The second light passes through a transmitting surface 32 (hereinafter referred to as a second transmitting surface) that is continuous with the second reflecting surface on the opposite side to the first transmitting surface, and is irradiated onto the light receiving surface of the first photodetector 51. The second transmitting surface is formed on the step side surface 34, or is formed on the same plane as the second reflecting surface.

[0074] The optical axis of the first light and the optical axis of the second light traveling in the direction in which the first reflecting member 30 is disposed travel in parallel with a predetermined distance therebetween. If this predetermined distance is taken as the first distance, the optical axis of the first light reflected by the first reflecting surface and the optical axis of the second light reflected by the second reflecting surface travel in parallel with a distance (hereinafter referred to as the second distance) shorter than the first distance. In other words, the second distance is smaller than the first distance.

[0075] Although the step-shaped first reflecting member 30 has been described as an example, the present invention is not limited thereto, and for example, a plurality of reflecting members may be used to realize an arrangement similar to that of the plurality of reflecting surfaces 31 of the first reflecting member 30. In other words, the light source device 1 can be said to include one or a plurality of reflecting members 30 as follows.

[0076] The one or more reflecting members 30 have a plurality of reflecting surfaces including a first reflecting surface and a second reflecting surface. The plurality of reflecting surfaces are planes parallel to each other, and may be arranged to be shifted in a direction perpendicular to the planes. Furthermore, a transmission area is provided between the first reflecting surface and the second reflecting surface. The transmission area is provided between two of the plurality of reflecting surfaces that satisfy a relationship in which no other reflection surface exists between two planes parallel to the respective reflecting surfaces. Therefore, one or more transmission areas are provided in relation to the plurality of reflecting surfaces.

[0077] The one or more transmission regions have a higher transmittance for transmitting light irradiated onto the reflecting surface than at least one of the two reflecting surfaces associated with the transmission region. The one or more transmission regions have a higher transmittance for transmitting light irradiated onto the two reflecting surfaces than either of the two reflecting surfaces associated with the transmission region. The upper limit of the transmittance here may include 100%. For example, the transmittance of a transmission region in which light travels straight without being blocked can be said to be 100%.

[0078] Furthermore, the transmission region provided between the first and second reflecting surfaces may exist between a virtual plane (first virtual plane) that is parallel to the optical axis of the light irradiated to the first reflecting surface and passes through the side of the first reflecting surface closest to the second reflecting surface, and a virtual plane (second virtual plane) that is parallel to the optical axis of the light irradiated to the first reflecting surface and passes through the side of the second reflecting surface closest to the first reflecting surface. The same can be said about a transmission region other than the transmission region provided between the first and second reflecting surfaces in terms of the relationship between the transmission region and the two reflecting surfaces related to this transmission region.

[0079] Although the embodiments of the present invention have been described above, the light source device according to the present invention is not strictly limited to the light source device of the embodiment. In other words, the present invention can be realized without being limited to the outer shape and structure of the light source device disclosed in the embodiment. In addition, the present invention can be applied without necessarily having all the components. For example, if some of the components of the light source device disclosed in the embodiment are not described in the claims, the freedom of design by those skilled in the art, such as substitution, omission, modification of shape, and change of material, is allowed for those some components, and the invention described in the claims is specified to be applied. [Industrial Applicability]

[0080] The light emitting device described in each embodiment can be used for lighting, projectors, vehicle headlights, head mounted displays, displays, and the like. [Explanation of symbols]

[0081] 1 Light source device 10. Chassis 11 Aperture 12 Exit port 20 Light emitting device 21 Packages 22 Light emitting element 23 Submount 24 Reflective material 25 Collimating Lens 30 Reflective material 31 Reflective surface 32 Transparent surface 33 Step top 34 Step Side 40 Condenser Lens 50 Photodetector 51 First photodetector 52 Second photodetector 60 Optical Fiber 70 Wavelength conversion material

Claims

1. a reflecting member having a plurality of reflecting surfaces including a first reflecting surface and a second reflecting surface, and one or a plurality of transmitting surfaces including a first transmitting surface connecting the first reflecting surface and the second reflecting surface; a first light emitting element that emits a first light that travels in a direction in which the reflecting member is disposed and that is incident on the first reflecting surface; and a second light emitting element that emits a second light that travels in a direction in which the reflecting member is disposed and that is incident on the second reflecting surface; a first photodetector including a first light receiving surface that is irradiated with the first light traveling in a direction in which the reflecting member is disposed and transmitted through the first transmitting surface; (However, this does not include a light source device having a movement mechanism that changes the ratio of light irradiated onto the multiple reflective surfaces and light transmitted through the one or multiple transparent surfaces by moving the positions of the multiple reflective surfaces relative to the light emitted from the multiple light-emitting elements and traveling toward the reflective member.)

2. 2. The light source device of claim 1, wherein an optical axis of the first light and an optical axis of the second light traveling in a direction in which the reflective member is arranged travel parallel to each other with a first distance therebetween, and an optical axis of the first light reflected by the first reflective surface and an optical axis of the second light reflected by the second reflective surface travel parallel to each other with a second distance therebetween that is shorter than the first distance.

3. one or more collimating lenses that collimate a plurality of light beams emitted from the plurality of light-emitting elements, including the first light and the second light; 3. The light source device according to claim 1, wherein the plurality of collimated light beams are incident on the plurality of reflecting surfaces.

4. A second photodetector having a second light receiving surface is further provided, the first photodetector is provided at a position where a first line passes through, the first line being a virtual line passing through an optical axis of the first light traveling in a direction in which the reflecting member is disposed; 4. The light source device according to claim 1, wherein the second light detector is provided at a position where a second line passes through, the second line being a virtual line passing through an optical axis of the first light reflected by the reflecting member.

5. the first photodetector is provided at a position where the second straight line does not pass, The light source device according to claim 4 , wherein the second photodetector is provided at a position where the first straight line does not pass.

6. a condenser lens that condenses the plurality of light beams emitted from the plurality of light-emitting elements and reflected by the reflecting member; The light source device according to claim 1 , further comprising an optical fiber into which the plurality of light beams condensed by the condenser lens are incident.

7. The light source device according to claim 6 , further comprising a wavelength conversion member that converts the wavelengths of the plurality of light beams incident on the optical fiber.

8. 8. The light source device according to claim 1, wherein the reflecting member has a stepped shape in which the plurality of reflecting surfaces and the one or a plurality of transmitting surfaces are alternately provided.

9. one or more reflective members having a plurality of reflective surfaces including a first reflective surface and a second reflective surface; a first light emitting element that emits a first light that travels in a direction in which the reflecting member is disposed and that is incident on the first reflecting surface; and a second light emitting element that emits a second light that travels in a direction in which the reflecting member is disposed and that is incident on the second reflecting surface; a first photodetector having a first light receiving surface provided with a transmission region that advances in a direction in which the reflecting member is disposed and exists between the first reflecting surface and the second reflecting surface, the first light being irradiated by the first light that has passed through the transmission region that transmits the first light more than the first reflecting surface; (However, this does not include a light source device having a movement mechanism that changes the ratio of light irradiated onto the multiple reflective surfaces and light transmitted through the transmissive area by moving the positions of the multiple reflective surfaces relative to the light emitted from the multiple light-emitting elements and traveling toward the reflective member.)

Images