Patent Publication Number: US-2021181614-A1

Title: Light-emitting device and projection display apparatus

Description:
TECHNICAL FIELD 
     The present technology relates to: a light-emitting device including a light-emitting element such as a semiconductor laser element, for example; and a projection display apparatus including the light-emitting device. 
     BACKGROUND ART 
     For example, a light-emitting device including a plurality of light-emitting elements such as semiconductor laser elements has been developed (see PTL 1, for example). The plurality of semiconductor laser elements is hermetically sealed collectively, for example. 
     CITATION LIST 
     Patent Literature 
     
         
         PTL 1: Japanese Unexamined Patent Application Publication No. 2017-208484 
       
    
     SUMMARY OF THE INVENTION 
     In such a light-emitting device, it is desired to suppress flow of gas (hereinafter, referred to as leakage) from a hermetically sealed space to the outside. 
     Therefore, it is desirable to provide a light-emitting device that is able to suppress occurrence of leakage and a projection display apparatus including the light-emitting device. 
     A light-emitting device according to an embodiment of the present technology includes: a package including a light-emitting element, a reflection member that reflects light outputted from the light-emitting element, and a sealed space that accommodates the light-emitting element and the reflection member; a base plate on which a plurality of the packages is mounted; and lenses opposed to the base plate with the plurality of packages interposed therebetween, the lenses being opposed to the respective packages. 
     A projection display apparatus according to an embodiment of the present technology includes the light-emitting device according to an embodiment of the present technology. 
     The light-emitting device and the projection display apparatus according to one embodiment of the present technology is provided with light-emitting elements for the respective plurality of packages. In other words, each light-emitting element is accommodated in a sealed space. 
     According to the light-emitting device and the projection display apparatus of an embodiment of the present technology, each light-emitting element is accommodated in the sealed space, which makes it possible to suppress the occurrence of leakage as compared with the case where the plurality of light-emitting elements is sealed collectively. Therefore, it is possible to suppress the occurrence of leakage. 
     It is to be noted that the above is an example of the present disclosure. The effect of the present disclosure is not limited to those described above, and may include other different effects or may further include other effects. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side schematic view of a schematic configuration of a light-emitting device according to a first embodiment of the present technology. 
         FIG. 2  is an exploded perspective view of a schematic configuration of the light-emitting device illustrated in  FIG. 1 . 
         FIG. 3  is an exploded perspective view of a specific configuration of a package illustrated in  FIG. 1  and the like. 
         FIG. 4  is a plan schematic view of an exemplary configuration of a back surface of the package illustrated in  FIG. 1  and the like. 
         FIG. 5  is a plan schematic view of a configuration of a front surface of a base plate together with the package illustrated in  FIG. 4 . 
         FIG. 6  is a plan schematic view of another exemplary configuration of the back surface of the package illustrated in  FIG. 1  and the like. 
         FIG. 7  is a plan schematic view of a configuration of the front surface of the base plate together with the package illustrated in  FIG. 6 . 
         FIG. 8  is a plan schematic view of a configuration of a top surface of a package according to a modification example 2. 
         FIG. 9  is a perspective view for explaining a connection between the package illustrated in  FIG. 8  and a terminal of a lens holding member. 
         FIG. 10  is an exploded perspective view of a schematic configuration of a light-emitting device according to a second embodiment of the present technology. 
         FIG. 11  is a diagram illustrating an exemplary configuration of a projection display apparatus to which the light-emitting device illustrated in  FIG. 1  or the like is applied. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     In the following, some embodiments of the present disclosure are described in detail with reference to the drawings. It is to be noted that description is given in the following order. 
     1. First Embodiment (an example of a light-emitting device in which a light-emitting element is sealed in each of a plurality of packages)
 
2. Modification Example 1 (an example including light-emitting elements that output light beams having different wavelengths)
 
3. Modification Example 2 (an example including an electrode extraction part on a front surface side of a package)
 
4. Second Embodiment (an example of a light-emitting device including a base plate provided with a holding part)
 
5. Application Example (an example of a projection display apparatus)
 
     First Embodiment 
     &lt;Structure of Light-Emitting Device  1 &gt; 
       FIG. 1  illustrates a schematic side configuration of a light-emitting device (a light-emitting device  1 ) according to an embodiment of the present technology, and  FIG. 2  is an exploded perspective view of the light-emitting device  1  illustrated in  FIG. 1 . The light-emitting device  1  includes a base plate  11 , a package  12 , a lens holding member  13 , and a lens array  14 . The package  12  is provided with a light-emitting element  121  and the like. The lens array  14  includes a lens  141  corresponding to each package  12 . 
     (Base Plate  11 ) 
     The base plate  11  is a member for mounting the package  12 . The base plate  11  is, for example, a flat plate-shaped member, and has a front surface  11 A and a back surface  11 B opposed to each other. The front surface  11 A is provided with a plurality of packages  12 , and the back surface  11 B is thermally coupled to, for example, a heat sink or the like (not illustrated). The front surface  11 A of the base plate  11  is provided with a wiring line (a wiring line  11 W in  FIGS. 5 and 7  to be described later) electrically coupled to the light-emitting element  121 . 
     The base plate  11  includes, for example, a ceramic material, a metal material, or the like. The base plate  11  including a metal material is able to enhance heat dissipation. Examples of the metal material include iron (Fe), an iron alloy, copper (Cu), and a copper alloy, and the like. Examples of the copper alloy include copper-tungsten (CuW) and the like. Examples of the ceramic material include aluminum nitride (AlN) and the like. The base plate  11  may be provided with a coolant channel. 
     The base plate  11  may be provided with a recess for mounting the package  12 . Providing the package  12  in the recess of the base plate  11  makes it possible to protect the package  12 . 
     (Package  12 ) 
     A plurality of packages  12  are mounted on the front surface  11 A of the base plate  11 . The plurality of packages  12  is, for example, arranged in a matrix on the front surface  11 A of the base plate  11  (in an X direction and a Y direction of  FIG. 2 ). For example, some of the packages  12  arranged in a matrix may be removed. The omission of some of the packages  12  is, for example, for a purpose of removing defective products or a purpose of reducing a part of a power density in the surface. The package  12  may be arranged in other forms, for example, a substantially hexagonal shape, a houndstooth shape, and the like. Each of the plurality of packages  12  has a light-emitting element  121 , a submount  122 , a mirror  123  (a reflection member), an accommodation member  124  (a first accommodation member), and a cover  125  (a second accommodation member) ( FIG. 1 ). 
     According to the present embodiment, in this way, the plurality of packages  12  is provided on the front surface  11 A of the base plate  11 , and the light-emitting element  121  is sealed in each package  12 . As will be described later in detail, this makes it possible to suppress the occurrence of leakage as compared with the case where the plurality of light-emitting elements  121  is sealed collectively. 
       FIG. 3  is an exploded perspective view of a specific configuration of the package  12 . In a central portion of the accommodation member  124 , a recess  124 R is provided, in which the light-emitting element  121 , the submount  122 , and the mirror  123  are accommodated. The cover  125  covers the recess  124 R. In other words, the accommodation member  124  and the cover  125  are provided in this order from a base plate  11  side. 
     One light-emitting element  121  is provided for each package  12 , for example. The light-emitting element  121  includes, for example, a semiconductor laser element such as an LD (Laser Diode). The light-emitting element  121  includes, for example, a gallium nitride (GaN)-based semiconductor material and outputs light in the blue wavelength range. A wavelength-conversion member such as a fluorescent material may be disposed in an optical path of the light outputted from the light-emitting element  121 . The light-emitting element  121  may include, for example, a semiconductor material such as a gallium arsenide (GaAs)-based material or the like. An anode and a cathode of the light-emitting element  121  are coupled to an electrode coupling part of the accommodation member  124  by wire bonding using wires W, for example. The wires W include, for example, gold (Au). 
     The submount  122  is for mounting the light-emitting element  121  and is provided between the light-emitting element  121  and a bottom surface of the accommodation member  124  (more specifically, a bottom surface of the recess  124 R). The submount  122  is, for example, a plate-shape member, and a position of the light-emitting element  121  may be adjusted using a thickness of the submount  122  (a size in a Z-direction in  FIG. 3 ). The submount  122  includes, for example, an insulating material such as aluminum nitride (AlN), silicon (Si), silicon carbide (SiC), diamond, beryllium oxide (BeO), or the like. 
     The submount  122  may include, for example, a conductive material such as copper tungsten (Cu—W), copper molybdenum (Cu—Mo), copper diamond, graphite, or the like. Using the conductive submount  122  makes it possible to cause one of the electrodes of the light-emitting element  121  to be electrically conducted to an electrode inside the accommodation member  124  through the submount  122 . As a result, for example, the number of wires W coupled to the light-emitting element  121  is reduced, which makes it possible to reduce a size of the package  12 . With reduction in the size of the package  12 , it becomes possible to lower the cost. Further, it becomes possible to more densely mount the packages  12  on the front surface  11 A of the base plate  11 . Still further, as will be described in detail later, the reduction in the size of the package  12  reduces an area of a bonding region between the accommodation member  124  and the cover  125 , and makes it possible to suppress the occurrence of the leakage and a crack in the accommodation member  124  due to concentration of stress in the bonding region. 
     The light-emitting element  121  is eutectically bonded to the submount  122  by AuSn (gold-tin), for example, and the submount  122  is eutectically bonded to the bottom surface of the accommodation member  124  by AuSn, for example. The submount  122  may be bonded to the bottom surface of the accommodation member  124  by, for example, silver (Ag) paste, sintered gold (Au), sintered silver (Ag), or the like. 
     The mirror  123  reflects the light outputted from the light-emitting element  121 . The light outputted from the light-emitting element  121  is reflected by the mirror  123 , and the light is outputted from a cover  125  side. The mirror  123  is provided on the recess  124 R of the accommodation member  124  together with the light-emitting element  121  mounted on the submount  122 . For example, a step is provided in the recess  124 R, and the mirror  123  is disposed at a position lower than a position of the light-emitting element  121  (a position closer to the bottom surface of the recess  124 R) ( FIG. 1 ). The inside of the recess  124 R may have a flat surface, and the mirror  123  and the light-emitting element  121  mounted on the submount  122  may be disposed on the same surface. 
     The mirror  123  has, for example, an inclined surface, and the inclined surface is disposed so as to be opposed to a light-emitting surface of the light-emitting element  121 . The inclined surface of the mirror  123  is inclined, for example, by 45° with respect to the bottom surface of the accommodation member  124 . This makes it possible to extract the light reflected by the inclined surface of the mirror  123  perpendicularly to the bottom surface of the accommodation member  124 . By adjusting the angle of the inclined surface of the mirror  123 , it is also possible to change a light extraction direction. The mirror  123  includes, for example, glass, synthetic quartz, silicon, sapphire, aluminum, or the like. The inclined surface of the mirror  123  may be provided with, for example, a reflective film such as a metallic film, a dielectric multilayer film, or the like. The reflective film has, for example, a reflectance of 90% or more with respect to the light outputted from the light-emitting element  121 . It is preferable that the reflective film have a reflectance of 99% or more. 
     The accommodation member  124  having the recess  124 R is bonded to the cover  125 , and together with the cover  125  seals the light-emitting element  121  mounted on the submount  122  and the mirror  123 . That is, the recess  124 R and the cover  125  constitute a sealed space. The recess  124 R has, for example, a rectangular planar shape. The accommodation member  124  includes, for example, a ceramic portion  124 S and a metal portion  124 M. The ceramic portion  124 S is for forming a three-dimensional form of the accommodation member  124 , and is included in the majority of the accommodation member  124 . The ceramic portion  124 S includes, for example, a sintered body such as aluminum nitride (AlN), aluminum oxide (alumina), silicon carbide (SiC), or the like. 
     The metal portion  124 M is disposed, for example, on the bottom surface of the recess  124 R and on a top surface of an outer side of the recess  124 R (a bonding surface with the cover  125 ). Such a metal portion  124 M include, for example, gold (Au) or the like. The provision of the metal portion  124 M on the bottom surface of the recess  124 R makes it possible to efficiently radiate heat and also to facilitate solder bonding with the submount  122 . The metal portion  124 M of the bottom surface of the recess  124 R is insulated, for example, from an electrode extraction part  12 E to be described later ( FIG. 4 , etc., to be described later). The metal portion  124 M provided on the top surface of the outer side of the recess  124 R is a portion to be bonded to the cover  125  and surrounds the recess  124 R in a frame shape. The metal portion  124 M and the cover  125  (specifically, a metal portion  125 M to be described later), for example, are bonded using a solder such as SnAgCu (tin-silver-copper). The solder may be an AuSn (gold-tin)-based solder, a Sn (tin)-based solder, an In (indium)-based solder, or the like. 
     In order to suppress a defect caused by excessive soldering, it is preferable that the metal portion  124 M on the outer side of the recess  124 R is disposed on an inner side of a frame portion surrounding the recess  124 R. Specifically, the frame portion surrounding the recess  124 R is a portion between an inner edge  124   i  forming a peripheral edge of the recess  124 R and an outer edge  124   o  forming an outer shape of the accommodation member  124 . It is desirable that the metal portion  124 M of the outer side of the recess  124 R be not in contact with at least one of the inner edge  124   i  or the outer edge  124   o.    
     By using such soldering or the like, it is preferable that the light-emitting element  121  or the like is hermetically sealed between the accommodation member  124  and the cover  125 . The reason therefor will be described below. 
     Driving of the light-emitting element  121  including the semiconductor laser element causes siloxane in the atmosphere to react with light in the vicinity of a light-emitting point, and a reactant tends to be deposited on an end surface of the light-emitting element  121 . This reactant causes a change in a reflectance of the end surface, which may cause a decrease in an optical characteristic and destruction of the light-emitting element  121 . When the wavelength of the light outputted from the light-emitting element  121  is, for example, a short wavelength of 500 nm or less, particularly 460 nm or less, a defect caused by the siloxane in the atmosphere is apt to occur. The hermetic sealing of the light-emitting element  121  or the like between the accommodation member  124  and the cover  125  makes it possible to suppress the occurrence of the defect caused by the siloxane in the atmosphere. 
     A top surface side of the accommodation member  124  is covered with the cover  125 , and a lower surface side of the accommodation member  124  is held on the front surface  11 A of the base plate  11  by, for example, silver (Ag) paste or the like. 
       FIG. 4  illustrates an exemplary planar configuration of a bonding surface of the accommodation member  124  with the base plate  11  (hereinafter referred to as back surface of the accommodation member  124 ). The back surface of the accommodation member  124  is provided with, for example, two electrode extraction parts  12 E and a heat radiation part  12 R. The two electrode extraction parts  12 E are where the electrodes are drawn from the anode and the cathode of the light-emitting element  121 . The accommodation member  124  is provided with a via, for example, such that the anode and the cathode of the light-emitting element  121  are drawn through the wires W and the via to the back surface of the accommodation member  124 . The heat radiation part  12 R is disposed at a position different from the positions of the electrode extraction parts  12 E, and is a portion for radiating heat generated in the light-emitting element  121  to the base plate  11 . It is preferable that the heat radiation part  12 R be disposed at a position overlapping with the light-emitting element  121 , i.e., immediately below the light-emitting element  121 , when viewed in a plane (e.g., an XY plane in  FIG. 3 ). As described above, the provision of the electrode extraction parts  12 E and the heat radiation part  12 R on the back surface of the accommodation member  124  makes it possible to be electrically coupled and thermally coupled to each package  12 . For example, the heat radiation part  12 R is provided on one portion in a long-side direction (the X direction in  FIG. 4 ) of the substantially rectangular parallelepiped accommodation member  124 , and the electrode extraction parts  12 E are provided on the other portion in the long-side direction thereof. The two electrode extraction parts  12 E are disposed side by side in, for example, the short-side direction (the Y direction in  FIG. 4 ) of the accommodation member  124 . 
       FIG. 5  illustrates an exemplary connection state between the electrode extraction parts  12 E and the heat radiation part  12 R included in the accommodation member  124  and the base plate  11  (the front surface  11 A). The front surface  11 A of the base plate  11  is provided with, for example, a plurality of wiring lines  11 W, and the electrode extraction part  12 E is bonded to the wiring line  11 W through silver (Ag) paste. This causes the anode and the cathode of the light-emitting element  121  to be electrically coupled to the wiring line  11 W, and a current flows through the light-emitting element  121 . On the front surface  11 A of the base plate  11 , a heat radiation part  11 R is provided for each package  12 . The heat radiation part  11 R is a portion bonded to the heat radiation part  12 R of the accommodation member  124  through the silver (Ag) paste. Heat radiation parts  12 R of packages  12  that are adjacent to each other (or the heat radiation part  11 R of the base plate  11 ) may be continuous through the silver paste. For example, as will be described later, by disposing all packages  12  on the front surface  11 A of the base plate  11  and then curing collectively the packages  12 , the heat radiation parts  12 R of the packages  12  that are adjacent to each other are continuously formed through the silver paste. Thus, by thermally coupling the heat radiation parts  12 R of the packages  12  that are adjacent to each other, the heat dissipation path is spread, and it is possible to improve a heat dissipation property. Here, the silver paste corresponds to a specific example of a heat conductive member according to the present technology. 
       FIG. 6  illustrates another exemplary planar configuration of the back surface of the accommodation member  124 , and  FIG. 7  illustrates an exemplary connection state between the electrode extraction parts  12 E and the heat radiation part  12 R illustrated in  FIG. 6  and the base plate  11  (the front surface  11 A). In this manner, the electrode extraction part  12 E, the heat radiation part  12 R, and the electrode extraction part  12 E may be disposed in this order along the long-side direction (the X direction in  FIG. 6 ) of the substantially rectangular parallelepiped accommodation member  124 . Although  FIG. 5  and  FIG. 7  each illustrate an example in which the plurality of packages  12  is coupled in series through the wiring lines  11 W, for example, the plurality of packages  12  may be coupled in parallel via the wiring lines  11 W. The arrangement of the electrode extraction parts  12 E and the heat radiation part  12 R is not limited to the examples illustrated in  FIG. 4  and  FIG. 6 . 
     In the cover  125  bonded to the accommodation member  124 , the light outputted from the light-emitting element  121  is extracted. The cover  125  is, for example, a plate-shape member having a rectangular planar shape, and covers at least the recess  124 R of the accommodation member  124 . The cover  125  includes: the metal portion  125 M soldered to the metal portion  124 M of the accommodation member  124 ; and a translucent portion  125 T. The metal portion  125 M is provided on a lower surface (a surface opposing the accommodation member  124 ). The metal portion  125 M has substantially the same planar shape as the planar shape of the metal portion  124 M of the accommodation member  124 . Specifically, the metal portion  125 M has a frame shape surrounding the recess  124 R, and a width of the metal portion  125 M is substantially the same as the width of the metal portion  124 M. The metal portion  125 M contains, for example, gold (A) or the like. At least a portion of the cover  125  covering the recess  124 R includes the translucent portion  125 T. For example, the majority of the cover  125  includes the translucent portion  125 T. The translucent portion  125 T includes a material having a high transmittance with respect to light of wavelengths outputted from the light-emitting element  121 . The translucent portion  125 T includes, for example, glass or the like. 
     Intervals of the plurality of packages  12  arranged in a matrix on the front surface  11 A of the base plate  11  are smaller in a θ-parallel direction than in a θ-perpendicular direction, for example. Since an FFP (Far Field Pattern) half-value width in the θ-parallel direction is narrower than an FFP half-value width in the θ-perpendicular direction, it is possible to reduce the intervals of the packages  12  in the θ-parallel direction. This makes it possible to increase a light density. The plurality of packages  12  may be arranged in a line. 
     (Lens Holding Member  13 ) 
     The lens holding member  13  provided between the base plate  11  and the lens array  14  has, for example, a frame shape surrounding the plurality of packages  12  mounted on the front surface  11 A of the base plate  11  ( FIG. 2 ). That is, the plurality of packages  12  is provided inside the frame-shaped lens holding member  13 . A planar shape of the lens holding member  13  is, for example, a quadrangular shape. The lens holding member  13  has, for example, a holding part  131  having a quadrangular frame shape and a widened part  132  widened on the inside and the outside of the holding part  131 . The widened part  132  is provided, for example, on two opposite sides of the quadrangular holding part  131 . The lens holding member  13  may not necessarily be provided over the entire circumference of the base plate  11 , and may be provided on three sides of the quadrangular base plate  11 , for example. Alternatively, the lens holding member  13  may be provided on two opposite sides of the quadrangular base plate  11 . 
     The lens holding member  13  is fixed to the base plate  11  using screws or the like (not illustrated), for example. A method of fixing the lens holding member  13  to the base plate  11  may be any method, and for example, an adhesive may be used to fix the lens holding member  13  to the base plate  11 . The adhesive includes, for example, a resin material. Alternatively, the lens holding member  13  and the base plate  11  may be collectively molded using an insert molding process or the like. 
     A thickness of the holding part  131  (a size in the Z direction in  FIG. 2 ) is greater than a thickness of the widened part  132 , for example. The holding part  131  is in contact with the base plate  11  and the lens array  14 . Thus, a distance between each package  12  and the corresponding lens  141  is adjusted by the thickness of the holding part  131 . Here, the lens holding member  13  corresponds to a specific example of a distance adjustment member according to the present technology. The thickness of the holding part  131  is preferably large enough to maintain a space between the cover  125  and the lens array  14  and between the base plate  11  and the lens array  14  which is large enough to allow gas to flow. A gas flowable size is, for example, about 0.01 mm, which is a machining tolerance, or about 0.5 mm, which is a tolerance in resin molding. If the cover  125  and the lens array  14  are too close to each other, a desorbed matter caused by an adhesive or the like stays therebetween. The desorbed matter reacts with light and adsorbs on the cover  125  or the lens array  14 , thereby deteriorates an optical property. The provision of the space having the gas flowable size between the cover  125  and the lens array  14  makes it possible to suppress such a decrease in the optical property. The holding part  131  has a thickness of, for example, about 1 mm to 30 mm. The thickness of the holding part  131  may be adjusted depending on, for example, a focal length of the lens  141  and an optical path length in the package  12 . The holding part  131  includes, for example, a resin material. 
     The widened part  132  is provided with, for example, a terminal  132 E. The terminal  132 E is for electrically coupling, for example, the package  12  (the light-emitting element  121 ) to the outside through the wiring line  11 W. A plurality of the terminals  132 E is provided from the inside to the outside of the widened part  132 . The terminal  132 E includes a conductive metal material such as, for example, aluminum (Al) or the like. The widened part  132  of a portion other than the terminal  132 E includes, for example, the same resin material as the resin material of the holding part  131 . The widened part  132  and the holding part  131  may include different resin materials. 
     The lens holding member  13  including such a terminal  132 E is formed, for example, by integral molding, and preferably includes one integrated component. This makes it possible to suppress the cost. In addition, forming the lens holding member  13  by integral molding makes it possible to reduce the cost. The lens holding member  13  may include a metal material such as aluminum (Al), SUS (Steel Use Stainless), iron (Fe), copper (Cu), or the like. Alternatively, the lens holding member  13  may include a ceramic material or the like. The shape of the lens holding member  13  may be formed by machining such as cutting, or may be formed by die casting, sintering, or the like. 
     (Lens Array  14 ) 
     The lens array  14  is opposed to the base plate  11  with the plurality of packages  12  interposed therebetween. The lens array  14  includes, for example, an array part  14 A in a central portion and a frame part  14 F surrounding the array part  14 A. In the array part  14 A, the plurality of lenses  141  is provided at positions opposing the respective packages  12 . Each lens  141  is disposed, for example, at a position overlapping with the light-emitting element  121  and the mirror  123  in a plan view. The lens  141  includes, for example, a convex lens. The lens  141  may include a plano-convex lens, a biconvex lens, a meniscus lens, or the like. Light transmitted through the cover  125  of each package  12  is collimated by passing through the lens  141 . The lens array  14  may have configurations that differ between a lower surface (e.g., a surface opposed to the base plate  11 ) side and a top surface side. For example, one surface side of the lens array  14  may have a FAC (Fast Axis Collimator) function, and the other surface side may have a SAC (Slow Axis Collimator) function. In the lens array  14  in this case, for example, flat surfaces of lenticular lenses disposed in directions perpendicular to each other are bonded. 
     The frame part  14 F around the array part  14 A has, for example, a quadrangular planar shape, and the frame part  14 F is in contact with the holding part  131  of the lens holding member  13 . The frame part  14 F is fixed to the holding part  131  by, for example, an adhesive or the like (not illustrated). As the adhesive, a photocurable resin such as a UV (Ultra Violet) curable resin or the like may be used. Shrinkage of the resin by photocuring makes it easier to cause a positional deviation between the lens array  14  and the lens holding member  13 . Thus, a resin material having a curing shrinkage amount of, for example, about several % or less is preferably used, and a resin material having a curing shrinkage amount of 1% or less is more preferably used. The lens array  14  may be fixed to the lens holding member  13  by screws or the like, for example. Alternatively, the lens array  14  and the lens holding member  13  may be collectively molded by an insert molding process or the like. As described above, a space having the gas flowable size is provided between the array part  14 A and the base plate  11 , and between the array part  14 A and the package  12 . The lens array  14  includes, for example, borosilicate glass or the like. 
     &lt;Method of Manufacturing Light-Emitting Device  1 &gt; 
     First, the package  12  is formed. Specifically, after disposing the submount  122 , the light-emitting element  121 , and the mirror  123  on the recess  124 R of the accommodation member  124 , the cover  125  is bonded to the accommodation member  124  using, for example, soldering. As a result, the light-emitting element  121  and the like are hermetically sealed, and the package  12  is formed. 
     Next, each package  12  is mounted on the front surface  11 A of the base plate  11 . At this time, the electrode extraction part  12 E of each package  12  is coupled to the wiring line  11 W. A position of each package  12  may be determined, for example, by a marker provided on the base plate  11 . Alternatively, the position may be determined by abutting the package  12  against a protrusion provided on the base plate  11 . After the first package  12  has been disposed on the base plate  11 , the subsequent package  12  may be disposed using, as the marker, an outer shape or a light emission point of the package  12  that has been disposed on the base plate  11 . The heat radiation part  12 R on the back surface of each package  12  may be sequentially bonded to the heat radiation part  11 R of the base plate  11  with silver (Ag) paste, or all of the packages  12  may be disposed on the base plate  11  and then collectively cured with the silver paste. Collectively curing all of the packages  12  makes it possible to shorten a curing time. 
     Here, the submount  122  and the mirror  123  are sealed together with the light-emitting element  121  in each package  12 ; thus, the light emission point and a oscillation direction of each package  12  are determined at a time point prior to mounting the package  12  on the base plate  11 . Therefore, by measuring an optical characteristic of each package  12  at this time point, it is possible to link each package  12  to the optical characteristic, and to suppress occurrence of variations between the packages  12  caused by individual differences and processing accuracies in the light-emitting elements  121 . In addition, it becomes possible to calculate the positions of disposing the packages  12  from the optical characteristics of the respective packages  12  and to make an optical characteristic in a plane uniform. 
     After the plurality of packages  12  is arranged in a matrix on the front surface  11 A of the base plate  11 , the lens holding member  13  is fixed to the base plate  11  using, for example, screws. Next, for example, the wiring line  11 W is coupled to the terminal  132 E. Thereafter, the frame part  14 F of the lens array  14  is fixed to the holding part  131  of the lens holding member  13  by using, for example, a resin material or the like. In this case, since it is only necessary to fix the arrangement of one component (the lens array  14 ) including the lenses  141  corresponding to the plurality of packages  12 , it is possible to fix the arrangement in a shorter time as compared with a case where the lenses are disposed one by one in the respective packages  12 . In addition, it is possible to enhance positional accuracy between each package  12  and the corresponding lens  141 . For example, it is possible to complete the light-emitting device  1  in this manner. 
     &lt;Operation of Light-Emitting Device  1 &gt; 
     In the light-emitting device  1 , for example, light is extracted as follows. In each package  12  mounted on the base plate  11 , light outputted from the light-emitting element  121  (e.g., light in the blue wavelength region) is reflected by the mirror  123  and transmits through the cover  125 . The light transmitted through the cover  125  passes through a lens  141  at a position corresponding to each package  12 , and becomes collimated light. Thus, traveling directions of the light beams passing through the respective lenses  141  are parallel to each other and are extracted from the light-emitting device  1 . 
     &lt;Workings and Effects of Light-Emitting Device  1 &gt; 
     In the light-emitting device  1 , the light-emitting element  121  is provided in each of the plurality of packages  12 . In other words, each light-emitting element  121  is sealed between the accommodation member  124  and the cover  125 . As a result, it is possible to suppress occurrence of leakage as compared with the case where the plurality of light-emitting elements  121  is sealed collectively. Hereinafter, workings and effects thereof will be described. 
     In a case where the plurality of light-emitting elements is collectively sealed between one accommodation member and one cover, a volume of the accommodation member is increased, and a bonding region between the accommodation member and the cover is also increased. A stress is concentrated on the large bonding region, and a crack and leakage in the accommodation member, the cover, and the like may occur. 
     Further, in a case where the leakage occurs, all of the plurality of light-emitting elements sealed in the accommodation member is discarded; hence, a yield greatly influences the cost. 
     In contrast, in the present embodiment, each light-emitting element  121  is sealed between the accommodation member  124  and the cover  125 ; thus, it is not necessary to increase the volume of the accommodation member  124 . Accordingly, it is possible to reduce the bonding region between the accommodation member  124  and the cover  125 . Therefore, it is possible to suppress the occurrence of the cracks and the leakage in the accommodation member  124 , the cover  125 , and the like caused by the concentration of the stress on the bonding region. 
     Further, if the leakage occurs in one package  12 , it is only necessary to discard one light-emitting element  121 , which makes it possible to suppress the influence of the discarded member on the cost. 
     Still further, since the plurality of packages  12  is disposed on the base plate  11 , if a defect occurs in one package  12 , it is possible to perform replacing of only this package  12 . Therefore, repair is easier than in the case where the plurality of light-emitting elements is sealed collectively. 
     In addition, since the each light-emitting element  121  is sealed to the package  12 , an amount of gas present in each package  12  (between the accommodation member  124  and the cover  125 ) is small as compared to the case where the plurality of light-emitting elements is sealed collectively. Therefore, it is possible to suppress reliability degradation caused by noxious gas present in each package  12 . The noxious gas is, for example, moisture or the like. 
     As described above, in the present embodiment, since each light-emitting element  121  is sealed between the accommodation member  124  and the cover  125 , it is possible to suppress the occurrence of leakage as compared with the case where the plurality of light-emitting elements is sealed collectively. Therefore, it is possible to suppress the occurrence of leakage. 
     Further, the lens holding member  13 , more specifically, the holding part  131 , is provided between the base plate  11  on which the plurality of packages  12  is disposed placed and the lens array  14 ; therefore, it is possible to adjust the distance between each package  12  and the corresponding lens  141  to a desired size. 
     Moreover, the submount  122  and the mirror  123  are sealed together with the light-emitting element  121  in one package  12 ; therefore, it is possible to determine the light emission point and the oscillation direction of each package  12  prior to mounting the package  12  on the base plate  11 . If the light-emitting element  121  and the mirror  123  are separately mounted on the base plate  11 , variations tend to occur in the respective mounting positions, and it is difficult to enhance the positional accuracy. In contrast, in the light-emitting device  1 , the submount  122  and the mirror  123  are sealed together with the light-emitting element  121  in one package  12 ; therefore, it is possible to enhance the positional accuracy at the time of mounting the plurality of packages  12  on the base plate  11 . 
     Hereinafter, modification examples of the first embodiment and other embodiments will be described; however, in the following description, the same components as those of the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted as appropriate. 
     Modification Example 1 
     The plurality of packages  12  (the light-emitting elements  121 ) mounted on the base plate  11  may output the respective light beams in different wavelength regions. The plurality of packages  12  mounted on the base plate  11  may include, for example, a package  12  including a light-emitting element  121  that outputs light in the red wavelength region, a package  12  including a light-emitting element  121  that outputs light in the blue wavelength region, and a package  12  including a light-emitting element  121  that outputs light in the green wavelength region. A ratio and an arrangement of the packages  12  of the respective colors are adjusted on the basis of a luminosity curve and an output (mW, Im). As a result, it is possible to extract white light from the light-emitting device  1 . In this case, for example, the light-emitting device  1  has a diffuser panel or the like, and the light outputted from the package  12  passes through the lens  141  and the diffuser panel or the like. 
     In this manner, it is possible to easily mount, on the base plate  11 , the packages  12  (the light-emitting elements  121 ) that output light beams in the wavelength regions different from each other in a desired ratio and in a desired arrangement. Therefore, it is possible to easily adjust an entire optical balance. 
     The light-emitting element  121  may include an LED (Light Emitting Diode) or the like; however, in the light-emitting element  121  including a semiconductor laser element, it is possible to increase the light intensity and to recognize the light at a more distant position as compared with the case where the light-emitting element  121  includes the LED. 
     Modification Example 2 
     Although the case where the electrode extraction part  12 E from the light-emitting element  121  is provided on the back surface of the package  12  has been described in the first embodiment, the electrode extraction part  12 E may be provided at a place other than the back surface of the package  12 . 
       FIG. 8  illustrates an exemplary planar configuration of the package  12  having the electrode extraction part  12 E on a top surface. Two electrode extraction parts  12 E are provided on the top surface of the package  12  exposed from the cover  125 . 
       FIG. 9  illustrates the package  12  illustrated in  FIG. 8  together with the terminal  132 E of the lens holding member  13 . For example, one electrode of the light-emitting element  121  is electrically coupled to one electrode extraction part  12 E, through the wire W, for example, and the other electrode of the light-emitting element  121  is electrically coupled to the other electrode extraction part  12 E through the conductive submount  122 . The electrode extraction parts  12 E provided on the top surface of the respective packages  12  are coupled to each other through, for example, wires (wires WA). The electrode extraction part  12 E of the package  12  located closest to the terminal  132 E of the lens holding member  13  is coupled to the terminal  132 E through the wire WA. This makes it possible to couple the outside and the light-emitting element  121  of the package  12 . 
     In the case where the electrode extraction part  12 E is provided on the top surface, the heat radiation parts  12 R of the back surfaces of the packages  12  that are adjacent to each other (or the heat radiation part  11 R of the base plate  11 ) may be continuous through the silver paste. By thermally coupling the heat radiation parts  12 R of the packages  12  that are adjacent to each other in a similar manner as described in the first embodiment, the heat dissipation path is spread, and it is possible to improve a heat dissipation property. 
     In this way, the package  12  having the electrode extraction part  12 E on the top surface is able to make the heat radiation part  12 R on the back surface of the package  12  ( FIG. 4  and  FIG. 6 ) larger. Therefore, it is possible to enhance heat dissipation and adhesive strength as compared with the package  12  having the electrode extraction part  12 E on the back surface. 
     Second Embodiment 
       FIG. 10  is a schematic exploded perspective view of a main part of a light-emitting device (a light-emitting device  2 ) according to a second embodiment of the present disclosure. The light-emitting device  2  includes the base plate  11 , the package  12 , and the lens array  14  in this order. That is, the light-emitting device  2  is not provided with a lens holding member (e.g., the lens holding member  13  in  FIG. 2 ). The base plate  11  of the light-emitting device  2  includes, for example, a plate part  111 , a holding part  112 , and a terminal  113 E. Except for this point, the light-emitting device  2  according to the second embodiment has a similar configuration as the light-emitting device  1  according to the first embodiment, and has similar workings and effects. 
     The plate part  111  of the base plate  11  is, for example, a plate-shape member having a quadrangular planar shape. The plurality of packages  12  is arrange on the plate part  111  in a matrix, for example. 
     The holding part  112  has a quadrangular frame-shaped planar shape surrounding the plurality of packages  12  arranged in a central portion of the plate part  111 . The holding part  112  is in contact with the plate part  111  and the lens array  14  (the frame part  14 F), and a distance between each package  12  and the corresponding lens  141  is adjusted by a thickness of the holding part  112 . Here, the holding part  112  of the base plate  11  corresponds to a specific example of a “distance adjustment member” of the present technology. 
     The terminal  113 E, for example, has a strip-shaped planar shape extending in one direction (the Y direction in  FIG. 10 ), and is provided on the plate part  111 . The terminal  113 E extends from an inner side to an outer side of the holding part  112 . The electrode extraction part  12 E of the package  12  ( FIG. 4  and  FIG. 6 ) is electrically coupled to the terminal  113 E, thereby electrically coupling the light-emitting element  121  to the outside. 
     The plate part  111 , the holding part  112 , and the terminal  113 E are, for example, integrated. The plate part  111  includes, for example, aluminum, the holding part  112  includes, for example, PEEK (polyether ether ketone), and the terminal  113 E includes a metal material. The plate part  111  and the holding part  112  are collectively molded by, for example, insert-injection molding or the like. The plate part  111  may include, for example, copper (Cu), copper tungsten (Cu—W), aluminum nitride (AlN), or the like, and the holding part  112  may include, for example, alumina, aluminum nitride, Kovar, or the like. In this case, the plate part  111  and the holding part  112  are insulated from the terminal  113 E by, for example, low-melting glass or the like. 
     As described above, instead of the lens holding member  13 , another member (e.g., the base plate  11 ) may be provided with a function of adjusting the distance between the package  12  and the lens  141 . 
     Application Example 
     The light-emitting devices  1  and  2  described in the first embodiment and the second embodiment are applicable to, for example, a projection display apparatus. 
       FIG. 11  is a diagram illustrating an exemplary configuration of a projection display apparatus (a projection display apparatus  200 ) to which the light-emitting device  1  or  2  is applied as a light source. The projection display apparatus  200  is, for example, a display device that projects an image on a screen. The projection display apparatus  200  is coupled to an external image supplying device such as a computer such as a PC or various image players through an I/F (interface), and performs projection on a the screen or the like on the basis of image signals inputted to the I/F. It is to be noted that the configuration of the projection display apparatus  200  described below is an example, and the projection display apparatus according to the present technology is not limited to such a configuration. 
     The projection display apparatus  200  includes the light-emitting device  1  or  2 , a multi-lens array  212 , a PbS array  213 , a focus lens  214 , mirrors  215 , dichroic mirrors  216  and  217 , light modulators  218   a  to  218   c , a dichroic prism  219 , and a projection lens  220 . 
     In the light-emitting device  1  or  2 , the light outputted from the light-emitting element  121  passes through the lens array  14  and is extracted as collimated light. The light enters the multi-lens array  212 . The multi-lens array  212  has a structure in which a plurality of lens elements arranged in an array, and condenses the light outputted from the light-emitting device  1  or  2 . The PbS array  213  polarizes the light condensed by the multi-lens array  212  to light of a predetermined polarization direction, for example, a P-polarized wave. The focus lens  214  condenses the light that has been converted by the PbS array  213  into the light of the predetermined polarization direction. 
     Of the light that has entered through the focus lens  214  and the mirror  215 , the dichroic mirror  216  transmits red light R and reflects green light G and blue light B. The red light R transmitted through the dichroic mirror  216  is led to the light modulator  218   a  through the mirror  215 . 
     Of the light reflected by the dichroic mirror  216 , the dichroic mirror  217  transmits the blue light B and reflects the green light G. The green light G reflected by the dichroic mirror  217  is led to the light modulator  218   b . On the other hand, the blue light B transmitted through the dichroic mirror  217  is led to the light modulator  218   c  through the mirror  215 . 
     The light modulators  218   a  to  218   c  optically modulate the respective inputted color light beams, and input the optically modulated color light beams to the dichroic prism  219 . The dichroic prism  219  combines color light beams that have been optically modulated and inputted into one optical axis. The combined color light beams are projected onto a screen or the like through the projection lens  220 . 
     In the projection display apparatus  200 , three light modulators  218   a  to  218   c  corresponding to three primary colors of red, green, and blue are combined, and all colors are displayed. That is, the projection display apparatus  200  is a so-called three-plate projection display apparatus. 
     Although the present technology has been described with reference to the embodiments and modification examples, the present technology is not limited to the embodiments and the like described above, and various modifications can be made. For example, the components, the arrangement, the number, and the like of the light-emitting devices  1  and  2  described in the above embodiments are merely examples, and the light-emitting devices  1  and  2  do not necessarily include all the components, and may further include other components. 
     Further, the cases have been described in which the light-emitting devices  1  and  2  are each provided with the terminal  132 E or  113 E for electrically coupling the light-emitting element  121  to the outside in the lens holding member  13  or the base plate  11 ; however, the terminal may be provided separately from the lens holding member  13  or the base plate  11 . 
     Further, in the above embodiments and the like, the cases have been described in which the holding part  112  of the lens holding member  13  or the base plate  11  functions as the distance adjustment member; however, the distance adjustment member may be provided separately from the lens holding member  13  and the base plate  11 . 
     In addition, in the above embodiments and the like, the cases have been described in which the sealed space is formed by the accommodation member  124  having the recess  124 R and the flat plate-shaped cover  125 ; however, the sealed space for accommodating the light-emitting element  121  and the like may be formed by the flat plate-shaped accommodation member  124  and the cover  125  having a recess. 
     It is to be noted that the effects described herein are mere examples, are not limited to those described herein, and may include any effects other than those described herein. 
     It is to be noted that the present technology may have the following configurations. 
     (1) 
     A light-emitting device including: 
     a package including a light-emitting element, a reflection member that reflects light outputted from the light-emitting element, and a sealed space that accommodates the light-emitting element and the reflection member; 
     a base plate on which a plurality of the packages is mounted; and 
     lenses opposed to the base plate with the plurality of packages interposed therebetween, the lenses being opposed to the respective packages. 
     (2) 
     The light-emitting device according to (1), in which the lenses are included in a lens array. 
     (3) 
     The light-emitting device according to (2), in which a gap is provided between the base plate and the lens array. 
     (4) 
     The light-emitting device according to any one of (1) to (3), further including 
     a distance adjustment member that adjusts a distance between the package and the lens to a predetermined size. 
     (5) 
     The light-emitting device according to (4), in which the distance adjustment member has a shape of a frame, and the plurality of packages is disposed inside the frame. 
     (6) 
     The light-emitting device according to (4) or (5), in which the distance adjustment member includes a terminal that electrically couples the light-emitting element to an outside. 
     (7) 
     The light-emitting device according to any one of (4) to (6), in which the distance adjustment member is integrated. 
     (8) 
     The light-emitting device according to any one of (4) to (6), in which the distance adjustment member is integrated with the base plate. 
     (9) 
     The light-emitting device according to any one of (1) to (8), in which the light-emitting element includes a semiconductor laser. 
     (10) 
     The light-emitting device according to (9), in which the semiconductor laser includes a gallium nitride (GaN)-based semiconductor. 
     (11) 
     The light-emitting device according to any one of (1) to (10), in which 
     the package further includes a first accommodation member provided with a recess and a second accommodation member that seals the recess, and 
     the sealed space is formed by the first accommodation member and the second accommodation member. 
     (12) 
     The light-emitting device according to (11), in which 
     the first accommodation member and the second accommodation member are provided in this order from a side of the base plate, and 
     the package further includes a submount, the submount being provided between the light-emitting element and the first accommodation member. 
     (13) 
     The light-emitting device according to (12), in which the submount is conductive. 
     (14) 
     The light-emitting device according to any one of (11) to (13), in which 
     the first accommodation member and the second accommodation member are provided in this order from a side of the base plate, and 
     an electrode extraction part is provided on a bonding surface of the first accommodation member with the base plate, the electrode extraction part being electrically coupled to an electrode of the light-emitting element. 
     (15) 
     The light-emitting device according to any one of (11) to (13), in which 
     the first accommodation member and the second accommodation member are provided in this order from a side of the base plate, and 
     an electrode extraction part is provided on a top surface of the first accommodation member, the top surface being exposed from the second accommodation member, the electrode extraction part being electrically coupled to an electrode of the light-emitting element. 
     (16) 
     The light-emitting device according to any one of (11) to (15), including the light-emitting elements that output light beams having wavelengths different from each other. 
     (17) 
     The light-emitting device according to any one of (11) to (16), in which the reflection member includes a mirror. 
     (18) 
     The light-emitting device according to any one of (11) to (17), further including 
     a heat conductive member between the package and the base plate, in which 
     the packages that are adjacent to each other are coupled to each other through the heat conductive member. 
     (19) 
     A projection display apparatus including 
     a light-emitting device, the light-emitting device including: 
     a package including a light-emitting element, a reflection member that reflects light outputted from the light-emitting element, and a sealed space that accommodates the light-emitting element and the reflection member; 
     a base plate on which a plurality of the packages is mounted; and 
     lenses opposed to the base plate with the plurality of packages interposed therebetween, the lenses being opposed to the respective packages. 
     This application claims the benefit of Japanese Priority Patent Application JP2018-152939 filed with the Japan Patent Office on Aug. 15, 2018, the entire contents of which are incorporated herein by reference. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations, and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.