Patent Publication Number: US-11655958-B2

Title: Light-emitting device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 17/185,640, filed on Feb. 25, 2021, which is a continuation of U.S. patent application Ser. No. 16/297,415, filed on Mar. 8, 2019, which is a continuation of U.S. patent application Ser. No. 15/157,897, filed on May 18, 2016, now U.S. Pat. No. 10,267,483, which claims priority to Japanese Patent Application No. 2015-103264 filed on May 20, 2015, and Japanese Patent Application No. 2016-051530 filed on Mar. 15, 2016. The entire disclosures of these applications are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a light-emitting device. 
     A light source device that collimates light emitted from a plurality of light sources with a collimator lens array is known (Japanese Patent Application Laid-open No. 2014-102367). 
     However, in the conventional light source device described above, respective lens elements constituting the collimator lens array have a plurality of curvatures in accordance with sectional shapes of laser beams incident to the respective lens elements. Therefore, when the collimator lens array is mounted even only slightly rotated from a prescribed direction, there is a risk that a significant deviation may occur in a positional relationship between the light sources and the lens elements and, consequently, an intensity distribution of light emitted from the collimator lens array may change. 
     SUMMARY 
     The problem described above can be solved by certain embodiments of the present invention. In one embodiment, a light-emitting device includes: a substrate; a lens array having a plurality of lens sections in a matrix pattern; and a plurality of semiconductor laser elements arranged on the substrate, wherein the plurality of semiconductor laser elements respectively emit a laser beam, each laser beam has a beam shape with a greater width in a column direction than in a row direction on a light incident surface of each of the plurality of lens sections, and the plurality of lens sections have an inter-vertex distance in the row direction that is smaller than both a maximum outer diameter of each of the lens sections and an inter-vertex distance in the column direction and have a same curvature in the row direction and the column direction. 
     According to the light-emitting device described above, a light-emitting device can be provided in which, even when the lens array is mounted slightly rotated from a prescribed direction, a significant deviation is less likely to occur in a positional relationship between a light sources and a lens element and intensity distribution of light emitted from the lens array is less susceptible to change. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1 A  is a schematic plan view of a light-emitting device according to a first embodiment; 
         FIG.  1 B  is a sectional view taken along A-A in  FIG.  1 A ; 
         FIG.  1 C  is a sectional view taken along B-B in  FIG.  1 A ; 
         FIG.  1 D  is a sectional view taken along C-C in  FIG.  1 A ; 
         FIG.  2 A  is a schematic plan view of a substrate; 
         FIG.  2 B  is a sectional view taken along D-D in  FIG.  2 A ; 
         FIG.  2 C  is a sectional view taken along E-E in  FIG.  2 A ; 
         FIG.  3 A  is a schematic plan view of a lens array; 
         FIG.  3 B  is a sectional view taken along F-F in  FIG.  3 A ; 
         FIG.  3 C  is a sectional view taken along G-G in  FIG.  3 A ; 
         FIG.  3 D  is a sectional view taken along H-H in  FIG.  3 A ; 
         FIG.  4 A  is a schematic plan view of semiconductor laser elements arranged on a substrate; 
         FIG.  4 B  is a sectional view taken along I-I in  FIG.  4 A ; 
         FIG.  4 C  is a sectional view taken along J-J in  FIG.  4 A ; 
         FIG.  4 D  is a diagram showing an enlargement of a portion enclosed by a dashed line in  FIG.  4 C ; 
         FIG.  5 A  is a schematic plan view of a sealing member; 
         FIG.  5 B  is a sectional view taken along K-K in  FIG.  5 A ; 
         FIG.  5 C  is a sectional view taken along L-L in  FIG.  5 A ; 
         FIG.  6 A  is a schematic plan view of a light-emitting device according to a second embodiment; 
         FIG.  6 B  is a sectional view taken along M-M in  FIG.  6 A ; 
         FIG.  6 C  is a sectional view taken along N-N in  FIG.  6 A ; 
         FIG.  6 D  is a sectional view taken along O-O in  FIG.  6 A ; 
         FIG.  7    is a schematic plan view of a light-emitting device according to a third embodiment; and 
         FIG.  8    is a schematic plan view of a light-emitting device according to a fourth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Light-Emitting Device According to First Embodiment 
       FIG.  1 A  is a schematic plan view of a light-emitting device according to a first embodiment. In addition,  FIG.  1 B  is a sectional view taken along A-A in  FIG.  1 A ,  FIG.  1 C  is a sectional view taken along B-B in  FIG.  1 A , and  FIG.  1 D  is a sectional view taken along C-C in  FIG.  1 A . In  FIG.  1 A , a semiconductor laser element  30  and the like that are arranged below a top left lens section are transparently shown in order to facilitate understanding. As shown in  FIGS.  1 A to  1 D , a light-emitting device  1  according to the first embodiment is an light-emitting device including: a substrate  10 ; a lens array  20  having a plurality of lens sections  22  in a matrix pattern; and a plurality of semiconductor laser elements  30  arranged on the substrate  10 , wherein the plurality of semiconductor laser elements  30  respectively emit a laser beam, each laser beam has a beam shape with a greater width in a column direction than in a row direction on a light incident surface LA of each of the plurality of lens sections  22 , and the plurality of lens sections  22  have an inter-vertex distance PX in the row direction that is smaller than both a maximum outer diameter E of each of the lens sections  22  and an inter-vertex distance PY in the column direction and has a same curvature in the row direction and the column direction. An orderly description will be given below. 
     (Substrate  10 ) 
       FIG.  2 A  is a schematic plan view of a substrate.  FIG.  2 B  is a sectional view taken along D-D in  FIG.  2 A .  FIG.  2 C  is a sectional view taken along E-E in  FIG.  2 A . As shown in  FIGS.  2 A to  2 C , for example, the substrate  10  includes a base  12 , a side wall  14  that protrudes from the base  12 , and a recess  10   a  formed by the base  12  and the side wall  14 . 
     The base  12  has a protrusion  12   a  and the protrusion  12   a  is formed inside of the recess  10   a . Since the use of the base  12  having the protrusion  12   a  described above enables warpage of the base  12  (this warpage is particularly likely to occur when the base  12  and the side wall  14  are made of different materials), which may occur due to the substrate  10  having the recess  10   a  to be suppressed, the semiconductor laser elements  30  and the like can be easily mounted to the base  12 . In addition, since arranging members such as the semiconductor laser elements  30  on the protrusion  12   a  enables the members to be brought closer to the lens array  20 , diffusion of laser beams on the light incident surfaces LA of the lens array  20  (the lens sections  22 ) can also be suppressed. Shapes and thicknesses of the substrate  10 , the base  12 , and the side wall  14  are not particularly limited and, for example, in addition to a member having the recess  10   a , a flat plate-like member (for example, a member without the side wall  14  and solely constituted by the base  12 ) can also be used as the substrate  10 . 
     For example, a metal material such as iron, iron alloy, and copper, a ceramic material such as AlN, SiC, and SiN, or a material combining these materials can be used as the substrate  10  (the base  12  and the side wall  14 ). 
     The substrate  10  is provided with wirings  90  (for example, leads) for electrically connecting the light-emitting device  1  to the outside. While the wirings  90  may be provided anywhere on an outer edge of the light-emitting device  1 , the wirings  90  are preferably provided on an upper surface or a side surface of the substrate  10 . In other words, the wirings  90  are preferably not provided on a lower surface of the substrate  10 . Accordingly, since an entire lower surface of the substrate  10  can be used as a mounting surface, even in a case where a plurality of semiconductor laser elements  30  that are heat sources are arranged on one substrate  10  as in the present disclosure, a light-emitting device with satisfactory heat dissipation can be provided. When providing the wirings  90  on the side wall  14  of the substrate  10 , since a height of the side wall  14  must be at a certain height or higher, the semiconductor laser elements  30  and the like arranged on the base  12  are to be arranged further away from the lens array  20  as compared to a case where the wirings  90  are not provided on the side wall  14 . However, even in such a case, the use of the base  12  having the protrusion  12   a  described above enables the semiconductor laser elements  30 , a mirror  50 , and the like to be arranged closer to the lens array  20  (the lens sections  22 ). 
     (Lens Array  20 ) 
       FIG.  3 A  is a schematic plan view of a lens array.  FIG.  3 B  is a sectional view taken along F-F in  FIG.  3 A .  FIG.  3 C  is a sectional view taken along G-G in  FIG.  3 A .  FIG.  3 D  is a sectional view taken along H-H in  FIG.  3 A . As shown in  FIGS.  3 A to  3 D , the lens array  20  has a plurality of lens sections  22  and a connecting section  24 . Each lens section  22  has a light incident surface LA and a light-emitting surface LB, and each laser beam incident to the light incident surface LA of each lens section  22  is refracted and emitted from the light-emitting surface LB of each lens section  22 . The connecting section  24  connects lens sections  22  adjacent to each other in a column direction (a Y direction in  FIG.  3 A ). Alternatively, the lens array  20  can be solely constituted by the lens sections  22 . In this case, for example, the lens sections  22  are directly connected to each other without involving the connecting section  24 . The lens array  20  (the lens sections  22  and the connecting section  24 ) can be formed using a transmissive material such as glass or synthetic quartz. 
     (Plurality of Lens Sections  22 ) 
     The plurality of lens sections  22  are provided in an m-row, n-column (m≥2, n≥1) matrix pattern. The plurality of lens sections  22  have an inter-vertex distance PX in the row direction (an X direction in  FIG.  3 A ) that is smaller than both a maximum outer diameter E of each of the lens sections  22  and an inter-vertex distance PY in the column direction (the Y direction in  FIG.  3 A ). Accordingly, since the respective lens sections  22  are consecutively formed in the row direction (the X direction in  FIG.  3 A ), a waste in space where a laser beam is not emitted in the row direction (the X direction in  FIG.  3 A ) can be reduced and downsizing of the lens array  20  (and, by extension, downsizing of the light-emitting device  1 ) can be achieved. An “inter-vertex distance in the column direction” refers to an inter-vertex distance between adjacent lens sections in the column direction. In addition, an “inter-vertex distance in the row direction” refers to an inter-vertex distance between adjacent lens sections in the row direction. A “vertex” refers to a center of a lens section in a plan view and a “maximum outer diameter” refers to a maximum diameter among diameters of the lens section in a plan view. 
     The inter-vertex distance PY in the column direction (the Y direction in  FIG.  3 A ) can be set preferably in a range of 1 mm or more and 12 mm or less, and more preferably in a range of 3 mm or more and 9 mm or less. The inter-vertex distance PX in the row direction (the X direction in  FIG.  3 A ) can be set preferably in a range of 0.5 mm or more and 9 mm or less, and more preferably in a range of 2 mm or more and 6 mm or less. By setting the inter-vertex distance PX and the inter-vertex distance PY to these lower limit values or more, mutual interference between laser beams from adjacent semiconductor laser elements  30  can be suppressed. By setting the inter-vertex distance PX and the inter-vertex distance PY to these upper limit values or less, a smaller light-emitting device can be provided. 
     The maximum outer diameter E of each lens sections  22  can be set preferably in a range of 1 time or more and 2 times or less, and more preferably in a range of 1.25 times or more and 1.75 times or less of the inter-vertex distance PX. By setting the maximum outer diameter E to these lower limit values or more, mutual interference between laser beams from adjacent semiconductor laser elements  30  can be suppressed. By setting the maximum outer diameter E to these upper limit values or less, a smaller light-emitting device can be provided. 
     Each of the lens sections  22  has a same curvature in the row direction (the X direction in  FIG.  3 A ) and in the column direction (the Y direction in  FIG.  3 A ). In other words, each of the lens sections  22  has a curved line with a curvature RX in a cross section in the row direction (the X direction in  FIG.  3 A ) that passes through the vertex of the lens section  22  and a curved line with a curvature RY that is equal to the curvature RX (curvature RX=curvature RY) in a cross section in the column direction (the Y direction in  FIG.  3 A ) that passes through the vertex of the lens section  22 . Accordingly, even when the lens array  20  is mounted slightly rotated from a prescribed direction, a significant deviation is less likely to occur in a positional relationship between a light source (the semiconductor laser element  30  or, when the mirror  50  is provided, the mirror  50 : hereinafter, the same description will apply) and the lens section  22 . Preferably, each of the lens sections  22  has a same curvature not only in the row direction (the X direction in  FIG.  3 A ) and in the column direction (the Y direction in  FIG.  3 A ) but in all directions passing through the vertex of each lens section  22 . In other words, each of the lens sections  22  has curved lines with a same curvature in all cross section that pass through the vertex of each lens section  22 . Accordingly, a significant deviation is more unlikely to occur in a positional relationship between the light source and the lens section  22 . 
     While not particularly limited, each of the plurality of lens sections  22  preferably has a shape capable of parallelizing (collimating) laser beam incident from each of the semiconductor laser elements  30 . For example, preferably, at least a part of each of the plurality of lens sections  22  has an aspherical curved surface (for example, the light incident surface LA is a flat surface and the light-emitting surface LB is an aspherical curved surface). Accordingly, laser beams from the semiconductor laser elements  30  can be parallelized without changing light intensity distribution. 
     Preferably, at least a part of outer edge of each of the plurality of lens sections  22  has an arc shape in a plan view. Accordingly, compared to a case where the outer edge of each of the plurality of lens sections  22  is constituted by other shapes in a plan view, since a larger number of aspherical curved surfaces can be provided in the lens sections  22 , laser beams from the semiconductor laser elements  30  can be emitted from the lens sections  22  in an efficient manner. 
     The lens array  20  can be fixed to the substrate  10  (when a sealing member  80  is provided between the substrate  10  and the lens array  20 , the sealing member  80 ) by known methods. For example, when directly fixing the lens array  20  to the substrate  10 , the lens array  20  and the substrate  10  can be fixed to each other by methods such as adhesion fixing, laser welding, resistance welding, or the like. When the lens array  20  is fixed by laser welding, resistance welding or the like, at least a part of the lens array  20  to be subjected to a welding process is constituted by a metal material. When the sealing member  80  is provided between the substrate  10  and the lens array  20 , the lens array  20  and the sealing member  80  can be adhesively fixed to each other using an adhesive such as a UV curable adhesive. 
     In order to make a space in which the semiconductor laser elements  30  are arranged a sealed space, preferably, the substrate  10  and a member that covers the substrate  10  are fixed by welding. However, welding is likely to cause displacement. Therefore, when the lens array is directly fixed to the substrate by welding and the substrate is directly covered by the lens array, there is a risk that the lens array may become displaced and incapable of causing incidence of light from the semiconductor laser elements in a prescribed mode (for example, a prescribed beam divergence angle or a prescribed positional relationship). In consideration thereof, in the present embodiment, the sealing member  80  that is a separate member from the lens array  20  is provided and the substrate  10  is to be covered by the sealing member  80 . Accordingly, the lens array  20  can be fixed to the sealing member  80  by a UV curable adhesive while fixing the sealing member  80  to the substrate  10  by welding. Thus, displacement of the lens array  20  can be suppressed while making a sealed space where the semiconductor laser elements  30  are arranged by the sealing member  80 . 
     (Plurality of Semiconductor Laser Elements  30 ) 
       FIG.  4 A  is a schematic plan view of semiconductor laser elements arranged on the substrate.  FIG.  4 B  is a sectional view taken along I-I in  FIG.  4 A .  FIG.  4 C  is a sectional view taken along J-J in  FIG.  4 A .  FIG.  4 D  is a diagram showing an enlargement of a portion enclosed by a dashed line in  FIG.  4 C . As shown in  FIGS.  4 A to  4 D , the plurality of semiconductor laser elements  30  are arranged on the substrate  10 . Specifically, the plurality of semiconductor laser elements  30  are arranged in the row direction (the X direction in  FIG.  4 A ) and in the column direction (the Y direction in  FIG.  4 A ). For example, each of the semiconductor laser elements  30  can be directly arranged on a bottom surface of the recess  10   a  (when using the base  12  having the protrusion  12   a , on the protrusion  12   a ) of the substrate  10  or can be arranged via a mounting body  40  or the like. By arranging each of the semiconductor laser elements  30  via the mounting body  40 , heat generated by each of the semiconductor laser elements  30  can be efficiently dissipated via the mounting body  40 . 
     The plurality of semiconductor laser elements  30  emit respective laser beams, and each laser beam is incident to the light incident surface LA of each lens section  22  either directly or reflected by the mirror  50  or the like. Each laser beam has a beam shape with a greater width in the column direction (the Y direction in  FIG.  4 A ) than in the row direction (the X direction in  FIG.  4 A ) on the light incident surface LA of each of the plurality of lens sections  22  (beam width in the column direction WY&gt;beam width in the row direction WX). Semiconductor laser element using nitride semiconductor or the like can be used as the semiconductor laser element  30 . 
     The plurality of semiconductor laser elements  30  can be electrically connected to each other by wires  60  or the like. As the wires  60 , gold, silver, copper, aluminum, or the like can be used. While a mode of connection is not particularly limited, for example, the plurality of semiconductor laser elements  30  provided in the row direction (the X direction in  FIG.  4 A ) can be serially connected to one another using the wires  60 . 
     In  FIG.  4 A , the plurality of semiconductor laser elements  30  are arranged on a straight line in each row and a relay member  70  is provided between adjacent semiconductor laser elements  30 . In addition, adjacent semiconductor laser elements  30  are electrically connected to each other by the wires  60  via the relay member  70 . Accordingly, since a length of each wire  60  can be relatively shortened, an increase in electric resistance can be suppressed. Furthermore, since a distance between adjacent semiconductor laser elements  30  can be made long in each row, thermal interference between adjacent semiconductor laser elements  30  can be reduced. As the relay member  70 , a metal material such as iron, iron alloy, or copper or an insulating material such as AlN, SiC, or SiN having electric wiring formed on an upper surface thereof can be used. The semiconductor laser element  30  is not arranged on the relay member  70 . 
     Preferably, an upper surface of the relay member  70  is positioned at a substantially same height as an upper surface of the mounting body  40  or an upper surface of the semiconductor laser element  30 . Accordingly, the wires  60  can be mounted more easily. When the semiconductor laser element  30  is provided on the mounting body  40 , the upper surface of the relay member  70  is positioned at a substantially same height as the upper surface of the mounting body  40 . Accordingly, compared to a case where the upper surface of the relay member  70  is positioned at a substantially same height as the upper surfaces of the semiconductor laser elements  30 , a thickness of the relay member  70  in a height direction can be made small and member cost can be reduced. 
     Each of the semiconductor laser elements  30  is arranged in m-row×n-column (m≥2, n≥1) in correspondence with each lens section. In this case, preferably, the number of the semiconductor laser elements  30  in the row direction is larger than the number of the semiconductor laser elements  30  in the column direction. In addition each of the semiconductor laser elements  30  is preferably disposed such that a distribution of light from the plurality of semiconductor laser elements  30  (light as the light-emitting device  1 ) forms a square. Accordingly, when the light-emitting device  1  is used as a part of a projector, a distribution of light intensity can be more easily made uniform. 
     (Mirror  50 ) 
     As shown in  FIGS.  4 A to  4 D , the light-emitting device  1  may include, on the substrate  10 , a mirror  50  that reflects emission light of the semiconductor laser element  30  toward the lens section  22 . The mirror  50  is arranged so that a light-emitting surface (a surface that emits a laser beam: hereinafter, the same description will apply) of the semiconductor laser element  30  and the mirror  50  are opposed to each other. Accordingly, a travel distance of a laser beam from the light-emitting surface of the semiconductor laser element  30  to the light-emitting surface of the lens section  22  (hereinafter, referred to as an “optical path length”) can be increased. Thus, optical density on the light-emitting surface of the lens array  20  can be reduced and optical dust collection on the surface of the lens sections  22  can be suppressed more easily. In addition, by increasing the optical path length, a change in an intensity distribution of light emitted from the lens sections  22  can be reduced as compared to cases where the optical path length is shorter (for example, a case where the mirror is not arranged and light is directly irradiated from the semiconductor laser element to the lens section). This is because, by increasing the optical path length, even if light from the semiconductor laser elements  30  is incident to the light incident surfaces of the lens sections  22  in a direction other than perpendicular due to a displacement of the semiconductor laser elements  30 , an inclination of the light after passing the lens sections  22  can be reduced. 
     The number, a shape, and the like of the mirror  50  are not particularly limited. For example, a plurality of mirrors that are elongated in the row direction (the X direction in  FIG.  4 A ) may be arranged in a plurality in the column direction or a plurality of mirrors  50  may be arranged in a pattern of a matrix of m-rows×n-columns (m≥2, n≥1) in correspondence with the plurality of lens sections  22 . When arranging the mirrors  50  in a matrix pattern, since one mirror  50  is provided corresponding to each of the plurality of lens sections  22 , even if a deviation occurs in a positional relationship between a given semiconductor laser element  30  and a given mirror  50 , positional relationships between the other semiconductor laser elements  30  and the other mirrors  50  are not affected by the deviation. Therefore, an influence due to deviation in mounting of one mirror  50  can be minimized. 
     Glass, synthetic quartz, sapphire, aluminum, or the like can be used for the mirror  50 . The mirror  50  has a reflecting surface that reflects emission light of the semiconductor laser element  30  (a laser beam emitted from the semiconductor laser elements  30 : hereinafter, the same description will apply). For example, a reflective film such as a dielectric multilayer film is provided on the reflecting surface. When causing each emission light of the plurality of semiconductor laser elements  30  to be incident as-is to the lens array  20  without using the mirror  50 , for example, the plurality of semiconductor laser elements  30  are arranged instead of mirrors  50  on the substrate  10  in a pattern of a matrix of m-row×n-columns (m≥2, n≥1). 
     Although not particularly limited, preferably, the mirror  50  is positioned directly below the vertex of the lens section  22 . Particularly preferably, a reflecting part of the mirror  50  is positioned directly below the vertex of the lens section  22 . Accordingly, since emission light of the semiconductor laser element  30  can be reflected by the mirror  50  toward the vertex of the lens section  22 , an intensity distribution of light emitted from the lens array  20  (the lens sections  22 ) is less susceptible to change. In this case, a reflecting part refers to a portion that reflects emission light of the semiconductor laser element  30  in the reflecting surface of the mirror  50 . 
     As shown in  FIGS.  1 A to  1 D  (for example, refer to the semiconductor laser element  30  and the mirror  50  transparently shown in the lens section  22  at a top left position in  FIG.  1 A ), preferably, the semiconductor laser element  30  and the mirror  50  are arranged on an inner side of outer edge of the lens section  22  in a plan view. Accordingly, since the semiconductor laser element  30  is arranged near the mirror  50 , an increase in an area of light emitted from the lens section  22  can be suppressed. 
     (Sealing Member  80 ) 
     As shown in  FIGS.  1 A to  1 D , the light-emitting device  1  may include a sealing member  80  between the substrate  10  and the lens array  20 . Providing the sealing member  80  enables a hermetic sealing effect to be increased as compared to a case where only the lens array  20  is provided. In particular, when using nitride semiconductor as the semiconductor laser element  30 , since organic material or the like is likely to collect on the emitting surface of the semiconductor laser element  30 , a hermetic sealing effect by the sealing member  80  becomes more prominent. 
       FIG.  5 A  is a schematic plan view of the sealing member. In addition,  FIG.  5 B  is a sectional view taken along K-K in  FIG.  5 A  and  FIG.  5 C  is a sectional view taken along L-L in  FIG.  5 A . In  FIG.  5 A , window parts  82   a  are transparently shown using dashed lines in order to facilitate understanding. As shown in  FIGS.  5 A to  5 C , the sealing member  80  includes a body part  82  having a plurality of window parts  82   a  and a transmissive member  84 . As the body part  82 , glass, metal, ceramics, or a material combining these materials can be used and, metal can be preferably used. Accordingly, since the substrate  10  and the sealing member  80  can be fixed to each other by welding or the like, hermetic sealing can be more easily achieved. Furthermore, as the transmissive member  84 , a member that allows transmission of at least emission light of the semiconductor laser elements  30  can be used. Shapes of the body part  82  and the transmissive member  84  are not particularly limited. For example, while the body part  82  includes a recess  82   b  on a side of the lens array  20  in the present embodiment, when using a flat plate-shape member as the substrate  10 , the recess  82   b  may be provided on the side of the substrate  10 . 
     While the body part  82  may include one window section  82   a  corresponding to two or more semiconductor laser elements  30 , preferably, the body part  82  respectively includes one window section  82   a  corresponding to one semiconductor laser element  30 . Accordingly, since a bonding area between the body part  82  and the transmissive member  84  excluding the window parts  82   a  can be increased, cracking of the transmissive member  84  due to stress can be suppressed when bonding the substrate  10  and the body part  82  to each other by resistance welding or the like to achieve a hermetic seal. 
     As described above, with the light-emitting device  1  according to the first embodiment, the plurality of lens sections  22  have a same curvature in the row direction (the X direction in  FIG.  1 A ) and in the column direction (the Y direction in  FIG.  1 A ). Therefore, a light-emitting device can be provided in which, even when the lens array  20  is mounted slightly rotated from a prescribed direction, a significant deviation is less likely to occur in a positional relationship between a light source and the lens section  22  and intensity distribution of light emitted from the lens array  20  is less susceptible to change. 
     Light-Emitting Device  2  According to Second Embodiment 
       FIG.  6 A  is a schematic plan view of a light-emitting device according to the second embodiment,  FIG.  6 B  is a sectional view taken along M-M in  FIG.  6 A ,  FIG.  6 C  is a sectional view taken along N-N in  FIG.  6 A , and  FIG.  6 D  is a sectional view taken along O-O in  FIG.  6 A . In  FIG.  6 A , the semiconductor laser element  30  and the like that are arranged below a top left lens section are transparently shown in order to facilitate understanding. As shown in  FIGS.  6 A to  6 D , a light-emitting device  2  according to the second embodiment differs from the light-emitting device  1  according to the first embodiment in that a plurality of lens arrays  20 A,  20 B,  20 C, and  20 D are arranged in the column direction (the Y direction in  FIG.  6 A ), and each of the plurality of lens arrays  20 A,  20 B,  20 C, and  20 D have a plurality of lens sections  22  in the row direction (the X direction in  FIG.  6 A ). With the second embodiment, in a similar manner to the first embodiment, a light-emitting device can be provided in which, even when the lens array  20  is mounted slightly rotated from a prescribed direction, a significant deviation is less likely to occur in a positional relationship between a light source and the lens section  22  and intensity distribution of light emitted from the lens array  20  is less susceptible to change. 
     Light-Emitting Device  3  According to Third Embodiment 
       FIG.  7    is a schematic plan view of a light-emitting device  3  according to the third embodiment. In  FIG.  7   , an outer edge of the recess  82   b  is indicated by a dashed line. In addition, in  FIG.  7   , hatchings are applied to a region in which the lens array  20  is fixed to the sealing member  80  by an adhesive. As shown in  FIG.  7   , in the light-emitting device  3 , the lens array  20  includes a connecting part  24  that connects lens sections  22  with each other and is fixed to the sealing member  80  at the connecting part  24  by the adhesive. The sealing member  80  includes the recess  82   b , which is recessed toward a region where a plurality of semiconductor laser elements  30  are mounted on the substrate  10 . In a plan view, the lens array  20  includes a through-hole F at an inner side of the recess  82   b  and is fixed to the sealing member  80  by the adhesive at an outer side of the recess  82   b.    
     When a space between the lens array and the sealing member is a sealed space, in a case where the lens array is fixed by an adhesive (for example, a UV curable adhesive) containing organic material, gas vaporized from the adhesive pools in the space between the lens array and the sealing member. In this case, the organic material contained in the vaporized gas may react to laser beam and may collect on the transmissive member or the lower surface of the lens array. In contrast, since the space between the lens array  20  and the sealing member  80  becomes an open space by providing the through-hole F in the connecting part  24 , gas vaporized from the adhesive is released to the outside of the space and collection of organic material (optical dust collection) can be more easily suppressed. The open space refers to a space that is open to an area outside the light-emitting device. 
     Preferably, a plurality of through-holes F are provided. In addition the plurality of through-holes F are preferably provided so as to be symmetrical with respect to a center line of the lens array  20 . Accordingly, since a flow of air can be more easily formed in the space between the lens array  20  and the sealing member  80  (for example, when two through-holes are line-symmetrically provided, an air flow involving air flowing into the space via one of the through-holes and air flowing out from the space via the other through-hole is more easily formed), gas vaporized from the adhesive is further released to the outside of the space and collection of organic material (optical dust collection) in the space can be further easily suppressed. In addition, an occurrence of dew condensation in the space between the lens array  20  and the sealing member  80  can also be suppressed. Since an adhesive containing organic material such as a UV curable adhesive is a material that tends to absorb moisture, when the lens array  20  is fixed by a UV curable adhesive, moisture absorbed by the adhesive from the atmosphere is likely to pool in the space between the sealing member  80  and the lens array  20  and, depending on usage, dew condensation may occur in the space. Therefore, the configuration described above in which a flow of air is formed in the space can be particularly preferably applied to a case where the lens array  20  is fixed to the sealing member  80  by an adhesive containing organic material such as a UV curable adhesive. 
     Light-Emitting Device  4  According to Fourth Embodiment 
       FIG.  8    is a schematic plan view of a light-emitting device  4  according to a fourth embodiment. In  FIG.  8   , an outer edge of the recess  82   b  is indicated by a solid line and a dashed line. In addition, in  FIG.  8   , hatchings are applied to a region in which the lens array  20  is fixed to the sealing member  80  by an adhesive. As shown in  FIG.  8   , in the light-emitting device  4 , the sealing member  80  includes the recess  82   b , which is recessed toward a region where a plurality of semiconductor laser elements  30  are mounted on the substrate  10 . In a plan view, a part of an outer edge of the lens array  20  is arranged so as to be positioned at an inner side of the recess  82   b  (refer to an opening G in  FIG.  8   ) and the lens array  20  is fixed to the sealing member  80  by an adhesive at an outer side of the recess  82   b . Even with the light-emitting device  4 , since the space between the lens array  20  and the sealing member  80  becomes an open space, collection of organic material (optical dust collection) and an occurrence of dew condensation can be more easily suppressed. 
     The number and an arrangement of the opening G need only enable a part of the outer edge of the lens array  20  to be positioned at the inner side of the recess  82   b  and are not limited to the number and the arrangement illustrated in  FIG.  8   . However, preferably, the opening G is provided at two or more locations (not limited to four corners) at the outer edge of the lens array  20 . In addition, in this case, preferably, the openings G are provided so as to be symmetrical with respect to a center of the lens array  20 . Accordingly, in a similar manner to a case where a plurality of through-holes F are provided so as to be symmetrical with respect to the center line of the lens array  20 , a flow of air is more likely to be formed in the space between the lens array  20  and the sealing member  80 . Therefore, collection of organic material (optical dust collection) and an occurrence of dew condensation can be even more easily suppressed. 
     While the third and fourth embodiments have been described above, the through-hole F and the opening G are examples of specific configurations for making the space between the lens array  20  and the sealing member  80  an open space. The space between the lens array  20  and the sealing member  80  need only be opened so that gas generated inside the space can be released to the outside and a specific configuration of such an open state is not particularly limited. 
     While embodiments have been described above, the description is not intended to limit in any way the invention described in the claims.