具体实施方式：
[0019]Hereinafter, certain embodiments of the invention will be described with reference to the drawings. In the description below, portions having the same numerals in a plurality of the drawings indicate the same or similar portions or members.
[0020]Further, the embodiment described below are intended as illustrative of a light emitting device to give a concrete form to the technical idea of the present invention, and the scope of the present invention is not limited to the embodiment described below. The sizes, materials, shapes, and the relative configuration etc., of the components described in embodiments are given as an example and not as a limitation to the scope of the invention unless specifically described otherwise. The sizes and the positional relationships of the members in each of the drawings are occasionally shown exaggerated for ease of explanation.
[0021]The X direction along the X-axis may indicate a direction in the array plane where the light sources in the light emitting device for an embodiment are arrayed. The Y direction along the Y-axis indicates the direction perpendicular to the X direction in the array plane, and the Z-axis indicates the direction perpendicular to the array plane.
[0022]The direction in which the arrow is oriented in the X direction is indicated as a positive X (+X) direction, and the direction opposite to the positive X direction is indicated as a negative X (−X) direction. The direction in which the arrow is oriented in the Y direction is indicated as a positive Y (+Y) direction, and the direction opposite to the positive Y direction is indicated as a negative Y (−Y) direction. The direction in which the arrow is oriented in the Z direction is indicated as a positive Z (+Z) direction, and the direction opposite to the positive Z direction is indicated as a negative Z (−Z) direction. In the embodiments described below, an example in which the light emitting devices are configured to emit light toward the positive Z direction side will be described. Such an illustration does not limit the orientation of the light emitting device during use, and the light emitting device may be oriented in any appropriate direction.
Configuration of Light Emitting Device 1
[0023]The configuration of a light emitting device 1 according to one embodiment will be described.
Overall Configuration Example
[0024]FIGS. 1A and 1B are diagrams schematically illustrating an overall configuration example of the light emitting device 1. FIG. 1A is a schematic perspective view of the light emitting device 1 when viewed from a light emission side (the positive Z direction) side, and FIG. 1B is a schematic perspective view of the light emitting device 1 when viewed from the negative Z direction side.
[0025]As illustrated in FIGS. 1A and 1B, the light emitting device 1 includes a window member 16 configured to transmit light and an opening 10 through which the light passes, the window member 16 and the opening 10 located at the positive Z direction side. Further, the light emitting device 1 has a substantially cylindrical external shape. The opening 10 is provided on an inner side (the negative Z direction side) of the window member 16. The light emitting device 1 can emit light through the opening 10 and the window member 16 toward the positive Z direction side when a drive voltage is applied from a drive circuit 2.
[0026]The light emitting device 1 is secured to a wall or a ceiling of a building, for example, and is used as a lighting device configured to illuminate a space inside or outside the building. Alternatively, the light emitting device 1 is fixed to a wall or a ceiling of a store/facility and is used in applications such as a downlight, a spotlight, and indirect lighting for the purpose of space rendering of stores/facilities. The light emitting device 1 can also be installed in a movable structure such as a vehicle, and can also be used in applications such as a headlight that illuminates the surroundings of the movable structure.
[0027]While an example of the light emitting device 1 having a substantially cylindrical external shape is illustrated in FIGS. 1A and 1B, the light emitting device 1 may have other external shapes and can have any appropriate external shape, such as a prism shape.
[0028]FIG. 2 is an exploded perspective view schematically illustrating an example of the overall configuration of the light emitting device 1. As illustrated in FIG. 2, the light emitting device 1 includes a light emitting diode (LED) mounting substrate 11, a defining member 40, a holder member 14, a light guide member array 15, the window member 16, and flat springs 17.
[0029]In the light emitting device 1, the LED mounting substrate 11, a spacer 12, a glass plate 13, and the holder member 14 are aligned in this order along the Z direction and are secured by screwing with securing screws 19 into female screw holes in the holder member 14.
[0030]Further, in the light emitting device 1, the holder member 14, the light guide member array 15, and the window member 16 are aligned in this order along the Z direction and are secured by screwing with the securing screws 18 into female screw holes 161a in protruding portions 161 of the window member 16 through the flat springs 17.
[0031]The LED mounting substrate 11 is a substantially square plate-shaped member, and is a substrate provided with wirings to which a light source, such as an LED, and various electrical elements can be mounted. For example, a metal-based two-layer printed circuit board formed of aluminum, copper, or the like can be used for the LED mounting substrate 11. A substrate other than a metal-based substrate, such as a paper-epoxy substrate or a glass epoxy substrate, can also be used, but a metal-based substrate is preferable in terms of heat dissipation.
[0032]In the illustrated example, the LED mounting substrate 11 has eighteen LEDs 111. The eighteen LEDs may be collectively referred to as the “LEDs 111”. Each of the LEDs 111 is an example of a light source configured to emit light and is mounted on a placement surface 112, which is a surface of the LED mounting substrate 11 in the positive Z direction.
[0033]Further, the LED mounting substrate 11 includes a connector 113 for connecting the LED mounting substrate 11 to the drive circuit 2 via an electrical cable. Each of the LEDs 111 is electrically connected to the drive circuit 2 via the LED mounting substrate 11, and is configured to emit light in response to a drive voltage applied from the drive circuit 2.
[0034]The LED 111 is configured to emit, for example, white light. The LED 111 may be configured to emit light of a color other than white, and may be configured to emit monochromatic light. When the LED 111 is configured to emit white light, the white light can be selected from among various types including a light bulb color, a daytime white color, a daylight color, and the like.
[0035]For the LEDs 11, for example, a product designated by a product number NFSWE11A manufactured by Nichia Corporation, or the like can be used. In terms of efficiency of incidence of light on the light guide member array 15, it is preferable to reduce the amount of light traveling in oblique directions from the LED 111.
[0036]The defining member 40 includes the spacer 12 and the glass plate 13, and defines a distance between the LED 111 and a light guide member 151.
[0037]The spacer 12 is an example of a light passage member that allows light emitted from the LED 111 to pass between the LED 111 and a light incident end surface 151i of a light guide member 151 included in the light guide member array 15. The spacer 12 is disposed between the placement surface 112 on which the LEDs 111 are placed and the light incident end surface 151i in the Z direction. The light incident end surface 151i faces the LED 111, and is an end surface through which the light emitted from the LED 111 enters the light guide member 151. The spacer 12 preferably has a thickness greater than a thickness of the LED 111.
[0038]The spacer 12 is a substantially rectangular plate-shaped member and includes eighteen spacer-through holes 121, each having a rectangular shape in a plan view of the spacer 12, at positions each corresponding to a respective one of eighteen LEDs 111 mounted on the LED mounting substrate 11, when the spacer 12 is placed in alignment with the LED mounting substrate 11. The eighteen spacer through holes 121 may be collectively referred to as the “spacer through holes 121”.
[0039]The spacer 12 can be produced by forming the spacer through holes 121 in a plate-shaped member using a laser machining method, etc. Any appropriate material may be used for a material of the spacer 12, but aluminum is preferable because aluminum has sufficient strength to prevent deformation of gaps over time and has high heat dissipation performance for heat generated by the LEDs 111. Further, in order to reduce flare light, ghost light, or the like, a surface treatment such as blackening is more preferably performed on the spacer 12.
[0040]The spacer 12 has planar regions at the negative Z direction side and the positive Z direction sides, excluding regions in which the spacer through holes 121 are formed. The planar region at the negative Z direction side is in contact with a surface of the LED mounting substrate 11 on which the LEDs 111 are placed, and the planar region at the positive Z direction side is in contact with the glass plate 13. When the LED mounting substrate 11, the spacer 12, and the glass plate 13 in this state are secured to the holder member 14, the distance between each LED 111 and a corresponding light guide member 151 facing each other across the spacer through hole 121 is defined to be a predetermined distance. This predetermined distance corresponds to a distance between a light emitting surface of the LED 111 and the light incident end surface 151i of the light guide member 151. The predetermined distance is defined based on a thickness of the spacer 12 and a thickness of the glass plate 13.
[0041]The glass plate 13 is disposed between the spacer 12 and the light incident end surfaces 151i, and is an example of a light transmission member configured to transmit light emitted from the LEDs 111. The glass plate 13 is a plate-shaped member containing a glass material adapted to transmit light emitted from the LEDs 111. While the smaller a thickness of the glass plate 13, the higher an incidence efficiency, strength also needs to be secured. When considering reduction in the incidence efficiency, a thickness of the glass plate 13 is preferably 1.0 mm or less, and more preferably 0.5 mm or less. In one example, the glass plate 13 has a thickness of 0.21 mm. To reduce reflection of the light emitted from the LEDs 111 and increase the incidence efficiency on the light guide member 151, it is preferable to provide an anti-reflection (AR) film on a surface of the glass plate 13 on the LED 111 side, or on both surfaces of the glass plate 13 on the LED 111 side and the opposite side, using a coating technique or the like.
[0042]The holder member 14 is a box-like member that is hollow inside, and is open on the positive Z direction side. Further, eighteen holding holes 144 are defined in a bottom surface portion of the holder member 14, on the negative Z direction side. The holder member 14 holds the light guide member array 15 inside the holder member 14, in a state in which end portions of the eighteen light guide members 151 included in the light guide member array 15 are inserted into respective eighteen holding holes 144. Further, two engagement through holes 141 are formed in a front surface portion, located on the positive Z direction side, of the holder member 14. The holding holes 144 are illustrated in FIG. 4.
[0043]The holder member 14 is produced by, for example, injection-molding a resin material. To hinder light emitted from the LEDs 111 from leaking to the outside of the light emitting device 1, and to hinder visible light, such as sunlight, from entering the interior of the light emitting device 1 from the outside, a material that does not transmit the light emitted from the LEDs 111 and visible light is preferably used for the resin material of the holder member 14. Further, a material that has a linear expansion coefficient that allows for reducing thermal deformation due to heat generated by the LEDs 111 or irradiation with light emitted from the LEDs 111 is preferably used for the resin material of the holder member 14. Examples of the resin material include thermoplastic resins such as a polyphenylene sulfide (PPS) resin, a polycarbonate (PC) resin, an acrylic poly methyl methacrylate (PMMA) resin, an acrylonitrile butadiene styrene (ABS) resin, and a polyether ether ketone (PEEK) resin. The material of the holder member 14 is not limited to a resin, and the holder member 14 may be formed using a metal material such as an aluminum alloy.
[0044]The light guide member array 15 in the illustrated example includes the eighteen light guide members 151 that are arrayed in the array plane in a two-dimensional array. The eighteen light guide members 151 may be collectively referred to as the “light guide members 151”. Each of the light guide members 151 has a tapered shape that narrows toward the light incident end surface 151i. A cross section of each light guide member 151 intersecting a light guide direction of the light guide member 151 has a square shape.
[0045]The term “tapered shape” in the present specification refers to a shape of a long and narrow member in which the diameter, width, thickness, or the like is gradually reduced. In the present embodiment, when each of the light guide members 151 has a shape that narrows toward the light incident end surface 151i, the shape will be referred to as a tapered shape, even when inclinations of lateral surfaces of each light guide member 151 are not symmetrical with respect to the central axis of the respective light guide member 151. In the present embodiment, each of the light guide members has a rectangular shape in a cross section intersecting the central axis of the respective light guide member, but the cross-sectional shape may be other shape, such as a circular shape.
[0046]The light guide members 151 adjacent to each other are connected to each other on a light exit end surface 151o side, and eighteen light exit end surfaces 151o constitute the opening 10 of the light emitting device 1. On the light incident end surface 151i side of the light guide member array 15, adjacent light guide members 151 are separated from each other, and a gap between lateral surfaces of the adjacent light guide members 151 is widened toward the light incident end surfaces 151i. The light incident end surfaces of the eighteen light guide members 151 may be collectively referred to as the “light incident end surfaces 151i”, and the light exit end surfaces of the eighteen light guide members 151 may be collectively referred to as the “light exit end surfaces 151o”.
[0047]Light emitted from the LEDs 111 enters the light guide members 151 through the light incident end surfaces 151i. The incident light is guided through a corresponding light guide member 151 while repeating total reflection on lateral surfaces of the light guide member 151, which are the tapered surfaces of each light guide member 151, and exits through a corresponding light exit end surface 151o.
[0048]To produce the light guide member array 15, a resin material adapted to transmit light emitted from the LEDs 111 is injection-molded, resulting in eighteen light guide members 151 integrally formed with each other. A silicone resin, a polycarbonate resin, an acrylic resin, or the like can be used for the resin material.
[0049]The window member 16 is a plate-like member that contains a resin material adapted to transmit light emitted from the LEDs 111. The window member 16 is an example of a pressing member that presses the light exit end surfaces 151o of the light guide members 151. The window member 16 includes the two protruding portions 161 at positions corresponding to the two engagement through holes 141 defined in the holder member 14. Each of the protruding portions 161 defines the female screw hole 161a. The window member 16 is produced by injection-molding a resin material. An acrylic resin, a polycarbonate resin, or the like can be used for the resin material. The window member 16 can also be made of a glass material.
[0050]With the holder member 14 in a state of holding the light guide member array 15, the window member 16 is attached to the holder member 14 such that the protruding portions 161 are fitted into the engagement through holes 141. In this state, the holder member 14 and the window member 16 are connected to each other by screwing with the fixing screws 18 into the female screw holes 161a of the protruding portions 161 through the flat springs 17.
[0051]The window member 16 is connected to the holder member 14 and presses the light exit end surfaces 151o. The window member 16 is connected to the holder member 14 without pressing the light exit end surfaces 151o, and when the light guide members 151 expand, the window member 16 presses the light exit end surfaces 151o. The window member 16 also functions as a protective member that prevents dirt, dust, and the like from entering the holder member 14, and also prevents the light guide member array 15 from coming directly into contact with external objects.
[0052]The flat spring 17 is a plate-like member containing a metal material such as stainless steel. The flat spring 17 is an elastic thin plate, and is an example of an elastic member that alleviates the pressing force exerted to the light exit end surfaces 151o by the window member 16.
[0053]Screwing through the flat springs 17 allows for reducing the connecting force between the holder member 14 and the window member 16. Accordingly, the window member 16 also moves more easily toward the positive Z direction side, compared to a case of screwing without the flat springs 17. With this structure, when the light guide members 151 expand toward the positive Z direction side due to thermal expansion or the like, the pressing force exerted by the window member 16 and pressing the light exit end surfaces 151o toward the negative Z direction side is reduced.
[0054]The quantity, arrangement, external shape, and the like of the LEDs 111, the spacer through holes 121, and the light guide members 151 illustrated in FIG. 2 are exemplary and can be selected as appropriate according to the purpose of the light emitting device 1.
Configuration Example of Light Guide Member Array 15
[0055]Next, the configuration of the light guide member array 15 will be described with reference to FIGS. 3A, 3B, and 3C. FIGS. 3A, 3B, and 3C are diagrams schematically illustrating a configuration example of the light guide member array 15. FIG. 3A is a front view, FIG. 3B is a side view, and FIG. 3C is a rear view.
[0056]As illustrated in FIGS. 3A, 3B, and 3C, the light guide member array 15 includes the 18 light guide members 151 in the array plane along the light incident end surfaces 151i. Each of the light guide members 151 includes the light incident end surface 151i and the light exit end surface 151o. The light incident end surface 151i has a substantially square shape with each side haying a length of 2.2 mm, and the light exit end surface 151o has a substantially square shape with each side having a length of 10.0 mm. Further, a height (a length in the Z direction) of the light guide member array 15 is 35 mm.
[0057]The sizes described above are examples, and the shape of each light guide member 151 is determined based on specifications of the LEDs 111 and a light distribution angle of the light emitting device 1. As used herein, the term “light distribution angle of the light emitting device 1” refers to an angle that is twice an angle formed between a line connecting the light emitting device 1 and a center of an emission pattern, and a line connecting the light emitting device 1 and a position on the emission pattern at which an illuminance is a half of a maximum illuminance in the emission pattern. This light distribution angle corresponds to a “half beam angle”, which is an angle in a spatial emission pattern at which the illuminance is a half of a maximum illuminance of the spatial emission pattern.
[0058]For example, the light incident end surface 151i may have a size in a range of 0.2 mm2 to 20 mm2, and may be larger than the size of the emission surface of the LED 111. Further, the light exit end surface 151o may have a size in a range of 0.2 mm2 to 100 mm2. The height (the length in the Z direction) of the light guide member array 15 may be in a range of 3 mm to 400 mm. The light distribution angle of the light emitting device 1 may be set to be in a range of 20 degrees to 120 degrees as the half beam angle.
[0059]As illustrated in FIG. 3A, in a central portion of the light guide member array 15, a total of twelve light guide members 151 are arranged in a matrix pattern, with three along the X direction and four along the Y direction. Further, in an end portion of the light guide member array 15 on the positive X direction side, three light guide members 151 are arrayed along the Y direction, and in an end portion of the light guide member array 15 on the negative X direction side, three light guide members 151 are arrayed along the Y direction.
[0060]Next, inclinations and distances of the central axes between the plurality of light guide members 151 will be described with reference to FIG. 3B.
[0061]A light guide member 151a of the light guide members 151 includes a light incident end surface 151ai and a light exit end surface 151ao. The light guide member 151a is an example of a first light guide member. A central axis 151ac of the light guide member 151a is an axis passing through both the center of the light incident end surface 151ai and the center of the light exit end surface 151ao.
[0062]Further, a light guide member 151b of the light guide members 151 includes a light incident end surface 151bi and a light exit end surface 151bo. The light guide member 151b is an example of a second light guide member. A central axis 151bc of the light guide member 151b is an axis passing through both the center of the light incident end surface 151bi and the center of the light exit end surface 151bo.
[0063]The central axis 151ac is inclined at an inclination angle θ with respect to the Z direction. The central axis 151bc is not inclined with respect to the Z direction. Therefore, the central axis 151ac and the central axis 151bc are inclined with respect to each other at the inclination angle θ.
[0064]Further, an interaxial distance di is an interaxial distance between the central axis 151ac and the central axis 151bc on the light incident end surface 151i side. An interaxial distance do is an interaxial distance between the central axis 151ac and the central axis 151bc on the light exit end surface 151o side. The interaxial distance do is longer than the interaxial distance di. In other words, the interaxial distance between the central axis 151ac and the central axis 151bc is greater on the light exit side than on the light incident side.
[0065]With this configuration, the light emitting device 1 including the light guide member array 15 can emit a diverging light that spreads while traveling in the positive Z direction.
[0066]Further, as illustrated in FIG. 3C, central axes 151c (collective designation) of respective the light guide members 151 are inclined in directions different from each other in a random manner. The inclinations of the central axes 151c of each of the light guide members 151 illustrated in FIGS. 3A, 3B, and 3C are exemplary, and the light guide member array 15 can be configured such that the central axis 151c of each of the light guide members 151 is inclined in any appropriate direction.
[0067]The quantity, arrangement, size, inclination of the central axis, and the like of the light guide members 151 are not limited to those described above and can be selected appropriately according to the purpose. Further, the light guide members 151 each having the square cross-sectional shape is illustrated above, but the light guide members 151 may have other cross-sectional shape. For example, the light guide members 151 may have a rectangular, polygonal, circular, or elliptical cross-sectional shape. The same applies to the cross-sectional shape of the spacer through hole 121 and the cross-sectional shape of the holding hole 144.
[0068]Furthermore, in the present embodiment, an example is illustrated in which light propagates inside the light guide member 151 by being totally reflected at the lateral surfaces of the light guide member 151, but the propagation of light inside the light guide member 151 may be caused by other configuration. For example, a deflection surface such as a reflection surface can be provided on a lateral surface of the light guide member 151 to deflect light at the lateral surface of the light guide member 151, which allows light to propagate inside the light guide member 151.
Configuration Example of Holder Member 14
[0069]Next, FIG. 4 is a diagram schematically illustrating an example of a configuration of the holder member 14. FIG. 4 is a schematic perspective view of the holder member 14 when viewed from the positive Z direction side. As illustrated in FIG. 4, the engagement through holes 141 are formed in a front surface portion 142 located on the positive Z direction side of the holder member 14. Further, eighteen holding holes 144 are formed in a bottom surface portion 143 provided on the negative Z direction side of the holder member 14. In FIG. 4, some of the eighteen holding holes 144 are hidden in the drawing.
[0070]Each holding hole 144 is a through hole having a square or rectangular cross-section. When an end portion of each light guide member 151 on the light incident end surface 151i side is inserted into the holding hole 144, the holding hole 144 can hold the end portion. The holding hole 144 is an example of a holding member that holds the end portion of each light guide member 151 on the light incident end surface 151i side.
[0071]As illustrated in FIG. 3C, the centers of the light incident end surfaces 151i are not arrayed at equal intervals, so that the holding holes 144 are arranged at uneven intervals in accordance with the positions of the light incident end surfaces 151i.
[0072]In the example herein, the light guide member array 15 contains a soft silicone resin, so that narrow portions of the light guide member array 15 on the light incident end surface 151i side easily moves due to impact or the like. When the narrow portions move, a light guide state of light guided inside the light guide members 151 may change.
[0073]In the present embodiment, when the end portion of each of the light guide members 151 on the light incident end surface 151i side is held by a corresponding one of the holding holes 144, a positional change of the narrow portion, on the light incident end surface 151i side, of each light guide member 151 can be reduced.
Configuration Example of LED 111 and LED Mounting Substrate 11
[0074]Next, the configuration of the LED 111 and the LED mounting substrate 11 will be described with reference to FIG. 5. FIG. 5 is a diagram illustrating an example of the configuration of the LED 111 and the LED mounting substrate 11.
[0075]As illustrated in FIG. 5, the LED 111 is a package including a light emitting element 111a, a phosphor layer 111b, a fillet 111d, and positive and negative electrodes 111e. The LED 111 may include other configurations.
[0076]The phosphor layer 111b is bonded to the light emitting element 111a using the fillet 111d as a bonding member. A lower surface and lateral surfaces of the light emitting element 111a, and the fillet 111d, are covered with a white resin 22 containing light-reflecting particles. Lateral surfaces of the phosphor layer 111b are not covered with the white resin 22. The positive and negative electrodes 111e are exposed from the white resin 22 and connected to the wirings of the LED mounting substrate 11.
[0077]The light-reflecting particles contained in the white resin 22 are particles having light reflectivity with respect to the light emitted from the LEDs 111, and are, for example, white titanium oxide particles, glass beads, calcium carbonate particles, aluminum powder, mica particles, or the like.
[0078]Further, as illustrated in FIG. 5, in the LED mounting substrate 11, a first insulating layer 11b, a first copper foil 11c, a second insulating layer 11d, a second copper foil 11e, a third insulating layer 11f, and other components are layered in this order on a base substrate 11aa. The first copper foil 11c and the second copper foil 11e are conductive with each other via a copper plating 11g.
Configuration Example of Periphery of LED 111
[0079]Next, a configuration around the LED 111 will be described with reference to FIGS. 6A and 6B. FIGS. 6A and 6B are cross-sectional views schematically illustrating the configuration around the LED 111. FIG. 6A illustrates a first example, and FIG. 6B illustrates a second example. FIGS. 6A and 6B illustrate a configuration around the LED 111 after each of the members of the light emitting device 1 are connected to each other. Further, the first example illustrated in FIG. 6A and the second example illustrated in FIG. 6B are different from each other only in the height (thickness) of the white resin 20 in the Z direction.
[0080]As illustrated in FIGS. 6A and 6B, the light emitting device 1 includes the LED 111 disposed on the placement surface 112 of the LED mounting substrate 11. Further, in the light emitting device 1, the white resin 20, the spacer 12, the glass plate 13, the bottom surface portion 143 of the holder member 14, and the end portion on the light incident end surface 151i side of the light guide member 151 are located around the LED 111. The LED 111 is disposed at the position at which the spacer through hole 121 of the spacer 12 is defined.
[0081]In the present embodiment, a height of the white resin 20 with respect to the placement surface 112 is greater than a height of an upper surface 111c (the light emitting surface) of the LED 111 with respect to the placement surface 112, and is equal to or less than a height of the spacer 12 with respect to the placement surface 112. In the present embodiment, the upper surface of the phosphor layer 111b (the upper surface 111c) corresponds to the light emitting surface of the light source.
[0082]FIG. 6A illustrates a case in which a height h1 of the white resin 20 with respect to the placement surface 112 is greater than a height h2 of the phosphor layer 111b, which is the light emitting surface of the LED 111, with respect to the placement surface 112. FIG. 6B illustrates a case in which a height h1′ of the white resin 20 with respect to the placement surface 112 is equal to a height h3 of the spacer 12 with respect to the placement surface 112.
[0083]A portion of the light emitted from the LED 111 may propagate in oblique directions from the LED 111. A large portion of light propagating in oblique directions from the LED 111 does not enter the light guide member 151, which leads to reduction in the incidence efficiency of the light from the LED 111 on the light guide member 151.
[0084]In the present embodiment, by providing the white resin 20, the light propagating in oblique directions from the LED 111 can be reflected toward an area directly above the LED 111. Accordingly, light propagating obliquely from the LED 111 can be guided to and caused to enter the light incident end surface 151i, and the deterioration of the incidence efficiency of the light can be suppressed. Propagating light 21 illustrated in FIG. 6A and propagating light 21′ illustrated in FIG. 6B are each an example of light that propagates obliquely the LED 111, and are reflected by the white resin 20 and guided to the light incident end surface 151i.
[0085]While the white resin 20 is provided in the present embodiment, the white resin 20 is not necessarily provided. Also, and the height h1 of the white resin 20 may be smaller than the height h2 of the phosphor layer 111b.
[0086]Further, as illustrated in FIGS. 6A and 6B, a surface of the glass plate 13 in the negative Z direction is in contact with a surface of the spacer 12