JP2010170990A - Light source module and illuminating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source module and an illumination device that reduce brightness unevenness caused by a plurality of point-like light-emitting parts and improve appearance. <P>SOLUTION: The light source module 11 includes a module substrate 14, a metal conductor 15 that is installed in a prescribed pattern on the front side face of the module substrate 14, a plurality of semiconductor light-emitting elements 19 electrically connected to the metal conductor 15 and mounted on the front side face of the module substrate 14, a white diffusion reflecting layer 17 that includes a plurality of holes 17a in which semiconductor light-emitting elements 19 are arranged is formed thinner than the thickness of the semiconductor light-emitting elements 19, and is laminated on the front side face of the module substrate 14, and a light-transmitting sealing member 24 mixed with phosphor in which semiconductor light-emitting elements 19 are embedded and that protrudes below the diffusion reflecting layer 17. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light source module including a plurality of semiconductor light emitting elements that emit light all at once, and an illumination device including the light source module.

  Conventionally, an LED light source including a plurality of LED (light emitting diode) bare chips that emit blue or ultraviolet light is known. The LED light source of Patent Document 1 regularly mounts a plurality of LED bare chips on a metal base printed board. A conductor pattern is formed on the insulating layer of the metal base printed board. Each bare chip is connected to the conductor pattern. A reflector is disposed on the metal base printed board. The reflector has a plurality of tapered holes in which each bare chip can be individually accommodated. Each hole is filled with a translucent sealing resin mixed with phosphor powder.

  The LED light source of Patent Document 1 is used as a planar light source by causing a bare chip to emit light all at once. The blue or ultraviolet light emitted from each bare chip is converted into white light by the phosphor powder as it passes through the sealing resin. The white light is provided for illumination with its light projecting direction defined by the inner surface of the tapered hole of the reflector that is much thicker than that of the bare chip.

  Furthermore, Patent Document 1 also describes an LED light source that does not include a phosphor and a reflector. In this LED light source, each LED bare chip mounted on the second substrate (insulating layer) of the metal base printed circuit board is individually sealed with a sealing resin.

JP-A-2004-193357 (paragraphs 0013-0022, 0027, 0031-0032, 0036, 0038, FIGS. 1 to 5, 7, and 9)

  It is known that the LED bare chip is a point light source and has high luminance. For this reason, in the LED light source of Patent Document 1 used as a planar light source, a light-emitting portion composed of each LED bare chip and a sealing resin covering the LED bare chip is visually recognized as a “bright” shape as a high-luminance point. For this reason, unpleasant glare associated with uneven brightness tends to occur.

  In particular, in the LED light source of Patent Document 1 including a reflector having a tapered hole, the light projecting direction of all light emitted from the light emitting unit is defined by the hole of the reflector, and the light is directly projected downward. Is done. Therefore, the luminance unevenness is more remarkable. As a result, unpleasant glare associated with uneven brightness tends to occur.

  Further, it is unclear whether or not the LED light source of Patent Document 1 that does not use a reflector can improve the unpleasant glare associated with the luminance unevenness. This is because, in the technique described in Patent Document 1, the exposed portion of the conductor pattern formed on the metal base printed board is covered with a sealing resin that seals the LED bare chip, and the portion of the conductor pattern other than the exposed portion is printed. It is not exposed from the substrate. And by this structure, moisture-proof property is improved. That is, Patent Document 1 does not mention any improvement in discomfort glare caused by uneven brightness.

  Furthermore, in the LED light source of Patent Document 1 that does not use a reflector, even if the amount of sealing resin used to cover each LED bare chip is the same, there is no contrivance to make the shape in the sealed state the same. Therefore, there is no guarantee that the sealing resin that seals the individual LED bare chips will be deformed variously and have the same shape and height. Therefore, when it implements as LED light source which mixed fluorescent substance powder in this sealing resin, although the luminescent color of each light emission part is the same color, it differs each. Differences in the shape and height of each light emitting part are visually recognized as uneven color.

  The illuminating device incorporating the LED light source that tends to cause uneven luminance and uneven color as described above does not look good. Therefore, it is desired to improve this point so that the merchantability of the lighting device can be improved.

  By the way, it is preferable that the illuminating device includes a translucent illumination cover as a guard in order to prevent a person from touching the charging unit (wiring pattern and LED bare chip) of the LED light source. Therefore, in an application in which unpleasant glare due to the LED light source is regarded as a problem, it is possible to improve luminance unevenness and color unevenness by using an illumination cover having a diffusion degree suitable for the application.

  That is, for example, by using a milky white lighting cover having the highest diffusion degree, the unevenness of brightness can be reduced by blurring the “crushing” feeling of the light emitting part by the light diffusing action of the lighting cover. However, when a milky white lighting cover is used, the luminous flux of the lighting device is reduced by about 10% compared to the fixture luminous flux when a transparent lighting cover is used, and the efficiency of the lighting device is also inevitably lowered. .

  The objective of this invention is providing the light source module and illuminating device which can relieve | moderate the brightness nonuniformity resulting from a some point light emission part, and can improve appearance.

  The invention according to claim 1 is a module substrate; a metal conductor provided in a predetermined pattern on the front surface of the module substrate; and electrically connected to the metal conductor and mounted on the front surface of the module substrate. A plurality of semiconductor light emitting elements; a plurality of holes in which the semiconductor light emitting elements are disposed; a white diffuse reflection formed to be thinner than the thickness of the semiconductor light emitting elements and stacked on the front surface of the module substrate And a translucent sealing member that fills the semiconductor light emitting element and protrudes below the diffuse reflection layer and is mixed with a phosphor.

  In the present invention, a metal base substrate in which an insulating layer is laminated on a metal base layer can be used as the module substrate. The insulating layer is made of an insulating material such as synthetic resin. For the metal base layer, for example, a material having good thermal conductivity such as aluminum can be used. The module substrate may be a single-layer or multi-layer substrate made of an insulating material such as an inorganic material such as ceramics or a synthetic resin. Examples of module substrates include resin substrates mainly made of glass epoxy resin, which has relatively low thermal conductivity but is relatively inexpensive, as well as non-metal substrates such as relatively inexpensive paper phenolic materials and glass composites. It can be used. The module substrate is preferably formed in a quadrangle, for example, a square or a rectangle in order to arrange the semiconductor light emitting elements at a desired interval. The module substrate may have a polygonal shape such as a hexagonal shape, a circular shape or an elliptical shape.

  In the present invention, the “surface on the front side of the module substrate” refers to the lower surface located on the front side of the lighting device. When this light source module is mounted on a lighting device having a lighting cover, this surface is covered with the lighting cover and faces the inner surface (back surface) of the lighting cover. Further, when the light source module is mounted on an illuminating device that does not have an illumination cover, this surface becomes visible through an open portion of the apparatus main body.

  In the present invention, a chip-like LED (light emitting diode) can be used as the semiconductor light emitting element. More specifically, for example, a chip-like blue LED emitting blue or ultraviolet light can be suitably used as the semiconductor light emitting element. For example, in order to emit white light, it is preferable to combine a phosphor and a blue LED. Alternatively, a chip group that emits white light by combining a chip-like red LED that emits red light, a chip-like blue LED that emits blue light, and a chip-like green LED that emits green light may be used. Is possible. In the present invention, the semiconductor light emitting elements or the chip groups are preferably arranged in a matrix in a scattered manner on the entire module substrate using, for example, COB (Chip on board) technology. The arrangement is not limited to a matrix shape, and can be arranged in a staggered pattern, a radial pattern, or the like by being scattered over the entire substrate body in accordance with the shape of the module substrate.

  Further, when the semiconductor light emitting element is a blue LED, it is preferable to combine a yellow phosphor that emits yellow light when excited with blue light in order to emit white light. Note that a red phosphor or a green phosphor may be mixed with a yellow phosphor in order to improve the color rendering properties. Further, in such a combination of blue LEDs and phosphors, the transparent sealing member such as a transparent silicone resin mixed with the phosphors forms a phosphor layer that fills all the blue LEDs and is laminated on the module substrate. May be provided. Alternatively, for example, a translucent sealing member in which phosphors are mixed by filling each blue LED or each chip group may be provided. The latter case is advantageous in that the amount of the phosphor and the translucent sealing member used is small compared to the former case, and the cost can be reduced.

  In the present invention, the white diffuse reflection layer may have a hole in advance, and may be a sheet attached to the front side surface of the module substrate, or leave a portion corresponding to the hole by screen printing or the like. A printed layer applied to the front surface of the module substrate, such as a white resist layer, can be used. That the diffuse reflection layer is white indicates that it is white. The reflectance of the diffuse reflection layer is preferably 85% or more in order to improve luminance unevenness. Furthermore, the shape of the hole of the diffuse reflection layer is not limited.

  In the present invention, a transparent synthetic resin such as a transparent silicone resin excellent in ultraviolet resistance and heat resistance can be suitably used for the sealing member. It is also possible to use a light-transmitting sealing material other than the above as the sealing member. Further, the sealing member can have various shapes such as a columnar shape, a prismatic shape, and a hemispherical shape. Further, the sealing member may be larger than the hole of the diffuse reflection layer. That is, the sealing member does not necessarily have to be enclosed in the hole, and may be spread outside the hole. That is, the sealing member may protrude above the diffuse reflection layer.

  In the present invention, the phosphor mixed in the sealing member is a substance that is excited by light emitted from the semiconductor light emitting element and emits light having a wavelength different from the wavelength of the light emitted from the semiconductor light emitting element. For example, when the semiconductor light emitting element is a blue LED, a yellow phosphor can be suitably used to obtain white light. The phosphor may be a phosphor other than the yellow phosphor, or a yellow phosphor mixed with a green phosphor or a red phosphor may be used in order to improve color rendering.

  During lighting of the light source module according to the first aspect of the invention, a part of the light emitted from the light emitting layer of the semiconductor light emitting element is transmitted through the sealing member to excite the phosphor. Then, the excited light and the light emitted from the light emitting layer mix with the light that has not excited the phosphor, for example, to produce white light. The white light is emitted in the light utilization direction, and illuminates the lower part through, for example, a translucent illumination cover.

  In this illumination, the light emitting layer of the semiconductor light emitting element emits light in all directions. Therefore, in this illuminating device, the diffuse reflection layer is irradiated with white light produced from the light emitted from the light emitting layer in the horizontal direction and obliquely upward and emitted from the sealing member. The irradiated light is diffusely reflected downward by the diffuse reflection layer, which is the light utilization direction.

  Thereby, it can suppress that the brightness | luminance of the vicinity of each light emission part which has the semiconductor light-emitting device and the sealing member with which this is embedded becomes remarkably high compared with periphery. That is, the luminance directly below the light emitting portion is less likely to be increased by the amount of diffuse reflection, and the luminance around the light emitting portion is increased by the light diffusely reflected around each light emitting portion, and the luminance ratio of that portion is increased. Get smaller. Therefore, the luminance unevenness of the light source module is alleviated, and accordingly, the unpleasant glare is improved and the appearance is improved.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the tip of the semiconductor light emitting element protrudes downward from the diffuse reflection layer. The “height of the semiconductor light emitting device” refers to a dimension from the lower surface of the module substrate to the tip (that is, the lower end) of the semiconductor light emitting device. For example, when the semiconductor light emitting element is fixed to the module substrate by some fixing member (for example, die bonding material), the height of the semiconductor light emitting element is, for example, the thickness of the semiconductor light emitting element and the fixing member (for example, fixing the semiconductor light emitting element). And the total thickness of the die bond material).

  In the light source module of the invention of claim 2, since the semiconductor light emitting element protrudes below the diffuse reflection layer, it is less affected by reflection and light absorption by the diffuse reflection layer, and is located near the horizontal direction from the semiconductor light emitting element. Even blue light can be emitted. As a result, similarly to the region directly below or obliquely below the light emitting unit, blue light and yellow light are mixed and white light is emitted in the region near the horizontal direction of the light emitting unit. For this reason, the color of light emitted directly below or obliquely below the light emitting portion is substantially the same as the color of light emitted in the vicinity of the horizontal direction, and the occurrence of angular color differences is suppressed.

  The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the sealing member is dammed up by a hole of the diffuse reflection layer. In the present invention, the holes of the diffuse reflection layer are preferably circular, but may not be circular.

  In the light source module according to the third aspect of the present invention, when the sealing member is installed by potting, the potted uncured sealing member is blocked from spreading further by the hole of the diffuse reflection layer. It can be cured. For this reason, each sealing member spreads along the surface of a diffuse reflection layer, and it is hard to lose shape, and these sealing members are easy to be made into the same shape. As a result, the conditions for exciting the phosphor in each light emitting part are unlikely to vary, and color unevenness in the relationship between the light emitting parts is unlikely to occur. As a result, it is possible to further improve the appearance of the lighting device as color unevenness is reduced.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the sealing member is formed in a substantially spherical shape having a diameter to height ratio of 2.0 to 7.8: 1. It is characterized by that.

  In the light source module according to the fourth aspect of the present invention, the correlated color temperature difference is within 1000K or less, and the angle color difference is less worrisome for the user.

  According to a fifth aspect of the present invention, there is provided the light source module according to any one of the first to fourth aspects; a base wall portion and a lower surface opening portion below the wall portion, and the light source on the lower surface of the base wall portion. An apparatus main body to which the module is fixed; and a translucent illumination cover that covers the light source module from below and is supported by the apparatus main body while closing the lower surface opening portion.

  In the present invention, a transparent lighting cover, a translucent lighting cover, a milky white lighting cover, or the like can be used as the translucent lighting cover depending on the usage environment of the lighting device. For example, a transparent illumination cover may be used in a usage environment where luminance unevenness is not so problematic. A semi-transparent lighting cover may be used in a use environment where the degree of uneven brightness is a problem. A milky white illumination cover may be used in a usage environment where brightness unevenness is a problem.

  In the illuminating device according to the fifth aspect of the present invention, the unevenness in luminance caused by the plurality of point-like light emitting portions included in the module can be alleviated by the configuration of the light source module itself as described above. For this reason, it is not necessary to alleviate the uneven brightness with the translucent lighting cover, and the uneven brightness reducing performance required for the lighting cover can be reduced. Therefore, it is possible to use a lighting cover with a low diffusion degree in a lighting device used in a usage environment in which uneven brightness is a problem. As a result, a reduction in instrument efficiency can be reduced.

  According to the light source module of the first aspect of the present invention, the luminance unevenness caused by a plurality of light emitting portions of the light source module itself can be alleviated by the configuration of the light source module itself, so that the appearance is improved.

  According to the light source module of the second aspect of the present invention, in the first aspect of the invention, further, the blue light can be emitted also in the vicinity of the horizontal direction of the light emitting portion, so that the angular color difference can be reduced.

  According to the light source module of the invention of claim 3, in the invention of claim 1 or claim 2, the color unevenness in the relationship between the light emitting parts can be alleviated, so that the appearance can be further improved.

  According to the light source module of a fourth aspect of the invention, in the invention of any one of the first to third aspects, the correlated color temperature difference can be kept below a predetermined value, so that the angular color difference can be reduced.

  According to the lighting device of the fifth aspect of the present invention, in the invention of any one of the first to fourth aspects, when the luminance unevenness of the light source module is further mitigated by the translucent lighting cover, the diffusivity is low. Since a translucent lighting cover can be used, a reduction in efficiency due to the lighting cover can be reduced.

The side view which shows the illuminating device which concerns on one Embodiment of this invention in the state which made the part the cross section. The top view which shows the illuminating device shown in FIG. The bottom view which shows the illuminating device shown in FIG. 1 in the state which notched some illumination covers. Sectional drawing which follows the F4-F4 line of the illuminating device shown in FIG. The bottom view which shows the light source module with which the illuminating device shown in FIG. 3 is provided. The top view which shows the light source module with which the illuminating device shown in FIG. 1 is provided. FIG. 6 is a bottom view showing a state in which a part of the light source module shown in FIG. 5 is enlarged and a part of a diffuse reflection layer included in the module is cut away; Sectional drawing which follows the F8-F8 line | wire of the light source module shown in FIG. Sectional drawing which follows the F9-F9 line of the light source module shown in FIG. Sectional drawing which follows the F10-F10 line | wire of the light source module shown in FIG. Sectional drawing which expands and shows a part of light source module shown in FIG. Sectional drawing which shows the light source module relevant to this invention. Sectional drawing which shows the modification of the light source module shown in FIG. The figure which shows the relationship between the ratio of the diameter / height of the sealing member of the light source module shown in FIG. 8, and a correlation color temperature difference. The figure which shows the relationship between the ratio of the diameter / height of the sealing member of the light source module shown in FIG. 8, and luminous efficiency. The figure which shows the relationship between the emission angle of the light source module shown in FIG. 8, and correlation color temperature.

An embodiment of the present invention will be described with reference to FIGS.
The code | symbol 1 in FIGS. 1-4 has shown the illuminating device. The lighting device 1 is realized as a lighting fixture commonly called a base light. The illuminating device 1 is directly attached or embedded in an indoor / outdoor ceiling, for example, for general lighting. The lighting device 1 includes a device body 2, a lighting device 10, one or more light source modules 11, and a translucent lighting cover 27.

  The apparatus main body 2 includes a main body base 3, a pair of end plates 5, and a main body housing 7, all of which are made of metal. The size of the apparatus main body 2 is, for example, about 280 mm in the vertical direction (vertical dimension) in FIG. 2, and 850 mm in the horizontal direction (horizontal direction) in FIG.

  As shown in FIGS. 1 to 4, the main body base 3 has a base wall portion 3a, a side wall portion 3b, and a base lower edge portion 3c. The base wall 3a has a flat plate shape such as a quadrangle, for example, a rectangle. The side wall part 3b is bent diagonally downward from both side edges of the base wall part 3a. The base lower edge portion 3c is bent horizontally from the lower end of the side wall portion 3b.

  For example, a plurality of rectangular part through holes 3d are formed in the base wall 3a, for example. The component through holes 3d are provided in the longitudinal direction of the main body base 3 in the same number as the light source modules 11 described later and at the same intervals as the arrangement intervals of the light source modules 11.

  The inner surfaces of the pair of side wall portions 3b are reflecting surfaces and face each other. These side wall portions 3b are inclined so that the distance between the inner surfaces gradually increases as the distance from the base wall portion 3a increases. The base lower edge 3c is bent in a direction approaching each other.

  The end plates 5 are fixed to both ends in the longitudinal direction of the main body base 3 with screws 6, respectively, and the longitudinal ends of the main body base 3 are closed. The inner surfaces of these end plates 5 are also reflective surfaces, and are inclined so that the distance between the inner surfaces gradually increases as the distance from the base wall portion 3a increases. End plate lower edge portions 5a bent horizontally from the lower ends of these end plates 5 are bent in directions approaching each other. The end plate lower edge portion 5a and the base lower edge portion 3c are continuous with each other, and are open portions facing the base wall portion 3a, for example, the lower surface open portion 4 facing the base wall portion 3a from below (FIGS. 3 and 5). 4).

  As shown in FIG.1 and FIG.4, the main body housing 7 has comprised the rectangular box shape by which the lower surface was open | released. The main body housing 7 is fixed to the upper surface of the main body base 3. More specifically, as shown in FIGS. 2 and 4, a pair of connecting fittings 8 extending in the same direction as the longitudinal direction of the base wall 3a is fixed to the upper surface of the base wall 3a. A main body housing 7 is disposed between the connecting fittings 8. The lower edge portion of the main body housing 7 is fixed to the connection fitting 8 with screws 9 respectively.

  A lighting device 10 for lighting the light source module 11 is fixed to the inner surface of the ceiling wall of the main body housing 7.

  The plurality of light source modules 11 are fixed to the lower surface of the base wall 3a with screws 12 (see FIG. 3). Adjacent light source modules 11 are in contact with each other and are continuous without a gap. Thereby, each light source module 11 is arrange | positioned over the substantially whole region of the base wall part 3a, as shown in FIG.2 and FIG.3. A planar light source unit is formed by the light source modules 11 arranged in this manner.

  Each light source module 11 is a COB (Chip on board) module. Each light source module 11 includes a module substrate 14, a metal conductor 15, a white diffuse reflection layer 17, a plurality of semiconductor light emitting elements such as blue LEDs (blue light emitting diodes) 19, and a translucent sealing member 24.

  The module substrate 14 has a quadrangle, for example, a rectangle as shown in FIG. The module substrate 14 is a multilayer substrate. For example, as shown in FIGS. 8, 9, and 10, the module substrate 14 includes a front-side insulating layer 31, a back-side insulating layer 32, and a heat diffusion layer 33.

  The front-side insulating layer 31 is a member that forms the front-side surface of the module substrate 14. The front-side insulating layer 31 is made of an insulating material such as a synthetic resin, more specifically, a glass epoxy resin plate. The back side insulating layer 32 is a member that forms the back side surface of the module substrate 14. Similar to the front-side insulating layer 31, the back-side insulating layer 32 is made of an insulating material, for example, a synthetic resin, more specifically, a glass epoxy resin. The back side insulating layer 32 is made of a plate having the same size and the same thickness as the front side insulating layer 31.

  The thermal diffusion layer 33 is a member disposed in the middle portion of the module substrate 14 in the thickness direction. In this embodiment, the thermal diffusion layer 33 is laminated on the entire surface of one side of the front side insulating layer 31 and the back side insulating layer 32. By laminating these heat diffusion layers 33, the heat diffusion layer 33 is sandwiched between the front-side insulating layer 31 and the back-side insulating layer 32. Therefore, the thermal diffusion layer 33 is provided over substantially the entire area of the module substrate 14.

  The heat diffusion layer 33 is made of a metal layer having the same size as the front-side insulating layer 31 and the back-side insulating layer 32, for example, a copper foil thinner than the front-side insulating layer 31 and the back-side insulating layer 32. Moreover, the laminated body which consists of the front side insulating layer 31 and the thermal diffusion layer 33 laminated | stacked on this, and the laminated body which consists of the back side insulating layer 32 and the thermal diffusion layer 33 laminated | stacked on this are the same.

  Two end fixing holes 14 a are formed at both ends in the longitudinal direction of the module substrate 14. In addition, one central fixing hole 14b and through holes 14c located on both sides of the module substrate are formed in the central portion of the module substrate. The central fixing hole 14b and the two through holes 14c are arranged in a line. The central fixing hole 14b and the two through holes 14c are used as a dividing base point when the module substrate 14 is divided into two if necessary.

  A screw 12 screwed into the base wall 3a is passed upward through each of the center fixing hole 14b and the end fixing hole 14a. The module substrate 14 is fixed to the base wall 3 a by tightening these screws 12.

  Specifically, the module substrate 14 is fixed to the lower surface of the base wall portion 3a with the front-side insulating layer 31 facing down. By this fixing, the back insulating layer 32 of the module substrate 14 is in close contact with the base wall 3a. Thereby, the heat radiation from the light source module 11 to the apparatus main body 2 is possible.

  In addition, the code | symbol 33a in FIG.5, FIG.6, FIG.10 shows a 1st escape hole. The first escape hole 33 a is opened in the thermal diffusion layer 33 in order to prevent conduction due to contact between the screw 12 and the thermal diffusion layer 33 or the like. Reference numeral 33b in FIG. 9 indicates a second escape hole. The second escape hole 33 b is opened in the thermal diffusion layer 33 in order to prevent conduction due to contact between a through hole and a thermal diffusion layer 33 described later.

  Metal conductors (see FIGS. 7 and 8) 15 are provided in a predetermined pattern on the front surface (ie, the lower surface) 14d of the module substrate 14. The metal conductor 15 is formed by plating gold on the copper foil mounted on the lower surface 14d or by plating nickel and gold in this order. As shown in FIG. 7, the metal conductor 15 has an element mounting portion 15a, an extending portion 15b, and an insulating groove portion 15c. The element mounting portion 15a has a substantially hexagonal shape, for example. The extending portion 15b has a linear shape extending integrally from the element mounting portion 15a. The insulating groove 15c is provided in the element mounting portion 15a.

  The width of the insulating groove 15c is wider than the width of the extending portion 15b. The tip of the insulating groove 15c reaches the substantially central portion of the element mounting portion 15a. The insulating groove 15c is provided so that the extending portion 15b of the metal conductor 15 disposed adjacent to the insulating groove 15c is inserted. As shown in FIG. 5, the element mounting portions 15 a of the metal conductors 15 are arranged in a matrix so as to be aligned vertically and horizontally with respect to the module substrate 14.

  The electrically insulating diffuse reflection layer 17 is made of, for example, a white resist layer, and is provided on the lower surface 14d of the module substrate 14 by printing. The thickness of the diffuse reflection layer 17 is not only much thinner than the module substrate 14 but also thinner than the blue LED 19 described later. The reflectance of the diffuse reflection layer 17 is preferably 85% or more. Furthermore, it is desirable to impart low wettability to the diffuse reflection layer 17.

  As shown in FIGS. 7 and 8, the diffuse reflection layer 17 has the same number of holes 17a as the element mounting portions 15a. These holes 17a are provided in the same arrangement as the arrangement of each element mounting portion 15a, and are opposed to the central portion of the element mounting portion 15a. Therefore, the metal conductor 15 is covered with the diffuse reflection layer 17 except for the portion facing each hole 17a. Each hole 17a consists of a circular hole, for example. In these holes 17a, as shown in FIG. 7, the tip portions of the extending portion 15b and the insulating groove portion 15c are located.

  As shown in FIG. 8, the blue LED 19 is made by providing a light emitting layer 19b on one surface of an element substrate 19a made of electrically insulating sapphire or the like. The light emitting layer 19b is provided with a pair of element electrodes (not shown). The thickness of the blue LED 19 is larger than the thickness of the diffuse reflection layer 17.

  These blue LEDs 19 are die-bonded to the element mounting portions 15 a of the respective metal conductors 15 by a die-bonding material 20. The blue LEDs 19 thus mounted on the lower surface 14d of the module substrate 14 are arranged one by one at the center of each hole 17a. Therefore, the blue LEDs 19 are arranged in a matrix in a vertical and horizontal manner according to the arrangement of the holes 17a so as to cover substantially the entire area of the lower surface 14d.

  Each blue LED 19 has a height larger than the thickness of the diffuse reflection layer 17. The “height of the blue LED 19” refers to the dimension from the lower surface 14d of the module substrate 14 to the tip (that is, the lower end) of the blue LED 19. That is, the height of the blue LED 19 is, for example, the sum of the thickness of the blue LED 19 and the thickness of the die bond material 20. The tip of each blue LED 19 protrudes below the surface (lower surface) of the diffuse reflection layer 17. The light emitting layer 19 b of each blue LED 19 is disposed below the surface (lower surface) of the diffuse reflection layer 17.

  Each blue LED 19 is electrically connected to the metal conductor 15 in the hole 17a in which it is disposed. That is, as shown in FIGS. 7 and 8, one element electrode of the blue LED 19 and the element mounting portion 15 a are connected via the first bonding wire 21. Further, the other element electrode of the blue LED 19 and the extending portion 15 b are connected via a second bonding wire 22. By such connection, the left two rows of blue LEDs 19 in FIG. 5 are connected in series, the central two rows of blue LEDs 19 in FIG. 5 are connected in series, and the right two rows of blue LEDs 19 in FIG. 5 are connected in series. It is connected. These series circuits are electrically connected in parallel by a circuit (not shown) and are fed by the lighting device 10. For this reason, when the lighting device 1 is used, the blue LEDs 19 emit light all at once and are illuminated.

  Further, as shown in FIG. 5, the blue LED 19 rows arranged in a row in the longitudinal direction of the module substrate 14 are provided at a constant pitch P along the width direction (direction orthogonal to the longitudinal direction) of the module substrate 14. It has been. The distance L between adjacent edges of the light source modules 11 that are in contact with each other, for example, the side edge 14e in the width direction of the module substrate 14, and the blue LED 19 row that is disposed closest to the side edge 14e is the pitch. The length is 1/2 of P.

  With this configuration, in the relationship between the adjacent light source modules 11, the blue LED 19 rows positioned on both sides of the side edge 14 e of the module substrate 14 are arranged at the same distance as the pitch P. Thereby, blue LED19 row | line | column is arrange | positioned by the same pitch P over the several light source module 11 continuous mutually (refer FIG. 3).

  For this reason, there exists an advantage which can suppress that a difference arises in the brightness of the below-mentioned translucent illumination cover 27 and an illumination area compared with the case where 19 rows of blue LED are uneven. At the same time, when the illumination cover 27 described later is transparent and each light source module 11 is visually recognized, the illumination cover 27 is translucent or milky white, and the light emitting unit 18 described later becomes a bright spot on the cover and is reflected subtly. Even if it is a case where it is visually recognized, it is preferable at the point which the space | interval of blue LED 19 row | line | column becomes uneven and is not visually recognized on the appearance of the illuminating device 1. FIG.

  The sealing member 24 is made of a translucent material such as a transparent silicone resin, and a yellow phosphor is mixed in a powder state (not shown). The sealing member 24 is supplied to each hole 17a by potting and cured. The sealing member 24 is provided on the lower surface 14 d so as to fill the central portion of the element mounting portion 15 a exposed in the hole 17 a and the blue LED 19. The root of the potted sealing member 24 is blocked by a hole 17a. The sealing member 24 has a hemispherical shape, for example, and projects downward from the lower surface of the diffuse reflection layer 17.

  An example of the sealing member 24 is formed in a substantially spherical shape having a diameter to height ratio of 2.0 to 7.8: 1, for example. That is, as shown in FIG. 8, the sealing member 24 may be formed in a hemispherical shape having substantially the same radius and height, and as shown in FIG. It may be formed in a spherical shape.

  Reference numeral 18 in the figure denotes a light emitting unit. The light emitting unit 18 includes a sealing member 24 and a blue LED 19 embedded therein. The arrangement of the light emitting portions 18 is the same as that of the blue LED 19. Accordingly, the light emitting units 18 are scattered throughout the entire area of the module substrate 14 and arranged in a matrix. The light emitting units 18 are arranged in the vertical and horizontal directions of the module substrate 14 with an interval of 5 to 20 mm. If the distance between adjacent light emitting portions 18 is less than 5 mm, the light emitting portions 18 having the blue LEDs 19 are in a dense state. In this state, the luminous flux per unit area increases too much, the average luminance increases, and unpleasant glare is likely to occur.

  On the other hand, if the distance between adjacent light emitting sections 18 exceeds 20 mm, the number of blue LEDs 19 used needs to be increased to compensate for the decrease in the luminous flux per unit area. For this reason, the light source module 11 needs to be enlarged, and the lighting device 1 is increased in size.

  In FIG. 5, the blue LED 19 group in the left two rows has both ends E of the first series circuit. The group of blue LEDs 19 in the center two rows has both ends E of the second series circuit. The right two rows of blue LEDs 19 have both ends E of the third series circuit. As shown in FIG. 9, the module substrate 14 is provided with a through hole 34 that penetrates the substrate 14 in the thickness direction. Both ends E of the first to third series circuits are integrally connected to the through hole 34.

  A back conductor 38 represented in FIG. 9 is provided in a predetermined pattern on the back insulating layer 32 forming the back of the module substrate 14. An electrical component that is a non-light emitting component is mounted on only the back surface of the module substrate 14 by being soldered to the back surface conductor 38. Specific examples of the non-light-emitting electrical component include, for example, the electrical connector 35, the capacitor 36, the constant current element, specifically the constant current diode 37 and the like shown in FIG.

  These electrical components occupy a partial area in the center surrounded by the periphery of the module substrate 14 and are arranged together. The region where these electrical components are arranged is a region facing the component through hole 3d by fixing the module substrate 14 to the base wall 3a as described above. Therefore, the electrical components such as the electrical connector 35, the capacitor 36, and the constant current diode 37 are passed through the component through hole 3d, as shown in FIG.

  In this way, the light source module 11 is fixed to the base wall 3a of the apparatus main body 2 through the electrical parts through the part through hole 3d. Thereby, the light source module 11 can be fixed in a state in which the light source module 11 is in surface contact with the base wall portion 3a of the apparatus main body 2 without hindering an electrical component mounted on the back side of the light source module 11.

  The module substrate 14 having the above configuration is screwed to the base wall portion 3a so that the longitudinal direction thereof coincides with the direction orthogonal to the longitudinal direction of the apparatus main body 2. As shown in FIGS. 3 and 4, the side edges 14e (see FIGS. 5 and 7) of the adjacent module substrates 14 are in contact with each other. Thereby, each module substrate 14 is continuously arranged without a gap in the longitudinal direction of the apparatus main body 2.

  The illumination cover 27 is supported by the apparatus body 2 by closing the lower surface opening portion 4. The illumination cover 27 covers the light source module 11 from below. The illumination cover 27 is supported by the apparatus main body 2 with its peripheral portion placed on the base lower edge portion 3 c of the main body base 3 and the end plate lower edge portion 5 a of the end plate 5. The lighting cover 27 may be any of a transparent lighting cover having a diffusivity that is negligibly small, a milky white lighting cover having a high diffusivity, or a translucent lighting cover having a lower diffusivity than the milky white lighting cover. It is selected according to the usage environment.

  When the lighting device 1 having the above-described configuration is turned on, the blue LEDs 19 included in the light emitting units 18 emit blue light all at once, and the lower space of the lighting device 1 is illuminated. That is, when a part of blue light emitted from the light emitting layer 19 b of the blue LED 19 is transmitted through the sealing member 24, the yellow phosphor contained in the sealing member 24 is excited.

  Therefore, the yellow light generated by excitation and the blue light that has not excited the phosphor in the light emitted from the light emitting layer 19b are mixed to produce white light. Then, the white light is emitted downward from the light emitting unit 18 and further passes through the translucent illumination cover 27 to illuminate the lower part of the illumination device 1 which is the light utilization direction.

  The module substrate 14 provided in the lighting device 1 has a white diffuse reflection layer 17 attached to the lower surface 14d thereof. The thickness of the diffuse reflection layer 17 is thinner than the thickness of the blue LED 19 mounted on the lower surface 14d. During lighting of the lighting device 1, light is emitted from the light emitting layer 19 b of the blue LED 19 in all directions.

  For this reason, the white light produced by the light emitting unit 18 by the light emitted from the light emitting layer 19b in the horizontal direction and obliquely upward is applied to the diffuse reflection layer 17 around the light emitting unit 18, and the diffuse reflection layer 17 transmits light. It is diffusely reflected downward, which is the direction of use. Thereby, although each light emitting part 18 having the blue LED 19 and the sealing member 24 in which the blue LED 19 is embedded is a point light source and has high luminance, the luminance in the vicinity of the light emitting part 18 is remarkably higher than the surroundings. Can be suppressed. That is, the luminance directly below the light emitting unit 18 is hardly increased by the amount of diffuse reflection. At the same time, the light diffusely reflected around each light-emitting portion 18 increases the luminance around the light-emitting portion 18, and the luminance ratio of that portion decreases.

  Therefore, the luminance unevenness of the light source module 11 in which the plurality of point light emitting units 18 are arranged in a matrix is alleviated. Accordingly, unpleasant glare is also improved, so that the appearance when the lighting device 1 is visually recognized is improved.

  Furthermore, in this embodiment, the side wall 3b and the end plate 5 of the apparatus main body 2 are inclined reflecting surfaces. For this reason, the white light emitted to the side from the respective light emitting portions 18 disposed at positions close to the side wall portion 3b and the end plate 5 is incident and reflected downward. For this reason, the luminance of the side walls 3b and the inner surfaces of the end plates 5 that are continuous with each other is increased. Also in this respect, the optical module 11 of the present embodiment has an advantage that it can contribute to alleviating luminance unevenness and can improve the light use efficiency.

  When the illumination cover 27 of the illuminating device 1 has diffusibility due to the reduction in luminance unevenness in the light source module 11, each light emitting unit 18 is clearly reflected in the illumination cover 27 as a high luminance point. Is suppressed. In other words, it becomes difficult for each light emitting unit 18 to be visually recognized through the illumination cover 27 in a “crush” shape. For this reason, the appearance of the lighting device 1 can be improved.

  In addition, as described above, the unevenness in luminance caused by the plurality of point light emitting portions 18 included in the light source module 11 can be alleviated with the configuration of the light source module 11 itself as described above. It is not necessary to take responsibility exclusively at 27. For this reason, it is possible to reduce the brightness unevenness mitigating performance required for the illumination cover 27. For this reason, it is possible to use the illumination cover 27 having a low diffusivity even in the illumination device 1 used in a usage environment in which luminance unevenness is a problem. Accordingly, the loss of light quantity in the lighting cover 27 is reduced, and the reduction in efficiency of the lighting device 1 due to the lighting cover 27 can be reduced.

  Incidentally, the size of the light source module 11 of the illumination device 1 according to the embodiment is 200 mm in the vertical dimension and 100 mm in the horizontal dimension in FIG. The light source module 11 includes six rows of 16 light emitting units 18 per row. The light source module 11 having this configuration has a performance capable of emitting a light beam of 800 lm. And the planar light source part of the illuminating device 1 is formed by arranging eight light source modules 11 continuously. Therefore, the lamp light flux of the entire illumination device 1 is (800 × 8) lm, that is, 6400 lm.

  In the illuminating device 1 having the structure in which the translucent illumination cover 27 is combined with the planar light source unit having the above-described configuration, the instrument light flux (the light flux of the illuminating device 1) was 6100 lm as a result of measurement. That is, this lighting device 1 (efficiency of the lighting device 1) was 95%. Moreover, in the illuminating device 1 having a configuration in which the milky white illumination cover 27 is combined with the same planar light source unit, the instrument luminous flux (luminous luminous flux of the illuminating device 1) was 6750 lm as a result of measurement. That is, the lighting device 1 (the efficiency of the lighting device 1) was 90%.

  On the other hand, in the lighting device having the configuration described in the prior art, the fixture efficiency in the configuration in which the translucent lighting cover 27 is combined is 90%, and the lighting device 1 in the configuration in which the milky white lighting cover 27 is combined. The efficiency is 85%. That is, it was confirmed that the lighting device 1 of the present embodiment has an improvement in appliance efficiency of 5%. This makes it possible to reduce the diffusivity of the illumination cover 27 included in the illumination device 1 of the present embodiment under the condition that the degree of relaxation of luminance unevenness in the illumination device of the present embodiment is the same as that of the prior art illumination device.

  As described above, luminance unevenness caused by the plurality of point light emitting units 18 included in the light source module 11 can be mitigated by the configuration of the light source module 11. For this reason, in the illuminating device 1 provided with the diffusive illumination cover 27, the illumination cover 27 arranged facing the planar light source unit from below can be arranged closer to the light source unit. Thereby, the illuminating device 1 can be made thin. If the illumination cover 27 is arranged far away from the planar light source unit without reducing the thickness, the reflection of the plurality of light emitting units 18 on the illumination cover 27 is further blurred. For this reason, the feeling of “crushing” due to uneven brightness in the illumination cover 27 can be further alleviated.

  Next, the effect of reducing the angular color difference by the above configuration will be described. For comparison, FIG. 12 shows a light source module in which the height of the blue LED 19 is smaller than the thickness of the diffuse reflection layer 17. As shown in FIG. 12, the blue LED 19 does not protrude below the diffuse reflection layer 17. In such a configuration, an angular color difference occurs.

  A solid line arrow in FIG. 12 indicates blue light emitted from the blue LED 19, that is, light passing through the sealing member 24 without exciting the phosphor. On the other hand, a broken-line arrow in FIG. 12 indicates yellow light, that is, light reflected by the phosphor of the sealing member 24. As described above, white light is generated by mixing the blue light and the yellow light.

  Here, the “exit angle” will be described first. The emission angle refers to an angle formed by the direction in which light is emitted with respect to the reference, with the vertical downward direction being the reference (0 °). That is, the horizontal direction is an emission angle of 90 °.

  As shown in FIG. 12, the blue light is radiated radially from the blue LED 19. Then, for example, the blue light radiated directly downward (emission angle 0 °) or obliquely downward travels to the outside as it is. On the other hand, for example, blue light emitted in the vicinity of the horizontal direction (emission angle 90 °) is affected by reflection and light absorption by the side surface of the diffuse reflection layer 17 and is not emitted outside. That is, blue light is not emitted to the region A2 near the horizontal direction.

  On the other hand, yellow light is light that is reflected and emitted from the phosphor particles of the sealing member 24. Therefore, yellow light is radiated from almost the entire sealing member 24 in all directions of the sealing member 24 regardless of the height of the blue LED 19. That is, yellow light is radiated to the vicinity of the horizontal direction as well as directly below and obliquely below.

  Therefore, as shown in FIG. 12, both blue light and yellow light exist in the area A1 directly below or obliquely below the light emitting portion 18, and both are mixed to emit white light. On the other hand, in the region A2 near the horizontal direction of the light emitting unit 18, only yellow light is present, so that yellow light is emitted as it is. A line S in FIG. 12 is a line connecting the light emitting layer 19b of the blue LED 19 and the lower end of the hole 17a.

  For this reason, in the configuration of FIG. 12, the color of the emitted light is different between the emission angle near 0 ° and the horizontal direction (emission angle 90 °), resulting in a color difference. When there is such an angular color difference, for example, when the illumination cover 27 is attached, for example, white and yellow color unevenness appears in the illumination cover 27. Even when the illumination cover 27 is not attached, if there is an angular color difference, illumination is performed with two illumination devices having different positions (for example, the illumination device directly above the user and the illumination device obliquely above). The colors look different.

  On the other hand, in the configuration of the present embodiment, as shown in FIG. 11, the height of the blue LED 19 is larger than the thickness of the diffuse reflection layer 17, and the blue LED 19 protrudes below the diffuse reflection layer 17.

  In this configuration, the blue light emitted in the horizontal direction (emission angle 90 °) from the blue LED 19 is less affected by the reflection and light absorption by the side surfaces of the diffuse reflection layer 17 and is emitted to the outside. For this reason, blue light also exists in the vicinity of the horizontal direction.

  As a result, both the blue light and the yellow light exist in the region near the horizontal direction of the light emitting unit 18 as well as the region directly below and obliquely below the light emitting unit 18, and both of them are mixed to emit white light. Is done. That is, white light is emitted almost in all directions of the light emitting unit 18 regardless of the emission angle. For this reason, the color difference hardly occurs near the emission angle of 0 ° and the horizontal direction (emission angle of 90 °), and the generation of the angle color difference is suppressed.

  In such a configuration, for example, white and yellow color unevenness hardly occurs in the illumination cover 27. Further, if the illumination cover 27 is not attached, it is possible to suppress the illumination color from being seen differently by two illumination devices having different positions.

  Further, the sealing member 24 included in each light emitting unit 18 having the above-described configuration is blocked by the hole 17 a of the diffuse reflection layer 17. The sealing member 24 is installed by potting. That is, the uncured sealing member 24 potted in the manufacturing can be cured in a state where it is blocked from further spreading in the hole 17a of the diffuse reflection layer 17. In other words, each sealing member 24 can be prevented from spreading along the surface of the diffuse reflection layer 17. For this reason, the sealing member 24 is not easily deformed.

  In particular, when low “wetability” is given to the diffuse reflection layer 17, the affinity between the uncured sealing member 24 and the diffuse reflection layer 17 decreases due to the wettability of the holes 17 a and the periphery thereof. Therefore, the uncured sealing member 24 is difficult to spread along the surface of the diffuse reflection layer 17. Therefore, there is an advantage that the sealing member 24 can be hardened while preventing the deformation of the shape more reliably.

  In addition, in order to give low “wetting property” to the diffuse reflection layer 17, a low wettability imparting material, for example, a fluorine-based material, more specifically, for example, a tetrafluoroethylene resin powder in the material forming the diffuse reflection layer 17. May be mixed. Alternatively, “low wettability” can be imparted by applying a grease-like fluorine-based material to the surface of the diffuse reflection layer 17 or spraying the fluorine-based material on the surface.

  The production yield of the light source module 11 in the case where the low “wetting property” is not given to the diffuse reflection layer 17 is 90%. On the other hand, when the grease-like fluorine-based material is applied to the surface of the diffuse reflection layer 17, the production yield of the light source module 11 is 95%. In this case, the production yield of the light source module 11 was 94%, and it was confirmed that both could improve the yield.

  As described above, since the sealing member 24 of each light emitting unit 18 is easily formed in the same shape, the conditions for exciting the phosphor in each light emitting unit 18 (for example, the thickness of the sealing member 24 including the phosphor, etc.) vary. hard. Therefore, the conditions under which white light is produced by the light emitting units 18 are substantially the same, and color unevenness due to the mutual relationship between the light emitting units 18 is unlikely to occur. Such alleviation of the uneven color improves the appearance of the lighting device 1.

  Furthermore, since the hole 17a is circular, the sealing member 24 installed by potting has a hemispherical shape and is cured. For this reason, in each light emitting part 18, the length of the optical path from the light emitting layer 19b of the blue LED 19 to the surface of each part of the sealing member 24 filling this, that is, the optical path in each part of the individual light emitting part 18 It is difficult to make a difference in length. As a result, color unevenness within one light emitting unit 18 is unlikely to occur. Therefore, the appearance of the lighting device 1 can be further improved with the relief of the color unevenness for each light emitting unit 18.

  The illumination device 1 having the above configuration uses a yellow phosphor as the phosphor. For this reason, each light emission part 18 which has this fluorescent substance and the translucent sealing member 24 with which this fluorescent substance was mixed is yellow. However, the light emitting units 18 are scattered in a matrix and distributed throughout the module substrate 14. Therefore, the entire module substrate 14 does not exhibit a yellow color. For this reason, when the module board | substrate 14 is visually recognized through the translucent illumination cover 27, the illuminating device 1 is not tinged with yellowish strongly in a light extinction state etc. As a result, there is an advantage that the merchantability of the lighting device 1 can be improved.

  Further, in the configuration in which the entire lower surface of the light source module 11 is covered with the translucent sealing member 24 mixed with the yellow phosphor, both the usage amount of the phosphor and the usage amount of the sealing member 24 are increased. These materials are not inexpensive. Therefore, the cost of the illuminating device 1 becomes high. However, in the configuration of the present embodiment, as described above, the light emitting units 18 are scattered in a matrix and are distributed throughout the module substrate 14. For this reason, the usage-amount of fluorescent substance and the usage-amount of the sealing member 24 are reduced significantly, and cost can be reduced.

  The angular color difference of the light source module 11 is also affected by the shape of the sealing member 24. In the configuration of the present embodiment, the sealing member 24 is formed in a substantially spherical shape with a diameter to height ratio of 2.0 to 7.8: 1, for example. According to such a configuration, the angular color difference of the light source module 11 can be further reduced. This will be described in detail with reference to FIGS. A small correlated color temperature difference means a small angle color difference.

  FIG. 16 shows the relationship between the emission angle and the correlated color temperature in several cases with different diameter / height ratios. Note that the “diameter” in the present specification is the diameter of the sealing member 24. That is, when the diameter / height ratio is 2.0, the sealing member 24 has a hemispherical shape. Then, as the diameter / height ratio increases, the sealing member 24 becomes flatter. As described above, the “outgoing angle” is an angle formed by a direction in which light is emitted with respect to the reference, with the vertical downward direction being a reference (0 °).

  FIG. 14 shows the relationship between the diameter / height ratio and the correlated color temperature difference. The “correlated color temperature difference” is a difference between the maximum value and the minimum value of the correlated color temperature when the emission angle is 0 ° to a predetermined angle (for example, 75 °). For example, point A in FIG. 14 indicates that the correlated color temperature difference is about 1000 K when the diameter / height ratio is about 2.08. This is obtained because the difference d between the maximum value and the minimum value is about 1000K in the graph line having the diameter / height ratio of 2.08 in FIG.

  Since most of the light reaching the user is emitted at an emission angle of 75 ° or less, the correlated color temperature difference in the range of the emission angle of 0 ° to 75 ° is important. Here, when the correlated color temperature difference exceeds 1000K, the color unevenness starts to be relatively noticeable. That is, it can be said that the maximum allowable value of the correlated color temperature difference that the user does not feel uncomfortable is 1000K.

  As shown in FIG. 14, the correlated color temperature difference is within 1000K in the range where the ratio of the diameter and height of the sealing member 24 is 2.0 to 7.8: 1. Within this range, the user is less likely to be concerned about the angular color difference.

  Here, the correlated color temperature at each irradiation angle is generally considered to be due to the length of the optical path from the blue LED 19 to the surface of the sealing member 24, that is, the optical path length at each part of the individual light emitting units 18. Yes. In that case, when the sealing member 24 is hemispherical (that is, the diameter / height is 2.0), the optical path length in each part is equal, and therefore the angular color difference should be minimized.

  Nevertheless, the above analysis results show that the angular color difference is minimized when the sealing member 24 is flat. For example, in the range where the ratio of the diameter and height of the sealing member 24 is 4.4 to 6.2: 1, the correlated color temperature difference is less than 600K, so the angular color difference can be further reduced.

  Note that the experimental conditions for analysis in FIGS. 14 to 16 are a phosphor weight density of 10% and a correlated color temperature of 5000K. In the case where the correlated color temperature is set to be constant, when a different phosphor density is adopted, the shape of the sealing member 24 is similarly changed in size. Therefore, even if the phosphor weight density is different, the same tendency as the above experimental condition can be obtained with respect to the angular color difference. In addition, the present inventors have confirmed that the same tendency as the above experimental conditions can be obtained at all of the color temperatures called white (for example, 4000 to 6000 K). That is, it is not limited to the above experimental conditions that the angle color difference can be reduced by setting the ratio of the diameter and height of the sealing member 24 in the range of 2.0 to 7.8: 1. .

  FIG. 15 shows the relationship between the diameter / height ratio and the luminous efficiency. As shown in FIG. 15, even if the diameter / height ratio is changed greatly, the luminous efficiency is hardly changed. That is, even if the shape of the sealing member 24 is changed in order to further reduce the correlated color temperature difference, the light emission efficiency of the light emitting module 11 hardly decreases.

  In consideration of the luminous efficiency, it can be said that the range in which the ratio of the diameter and height of the sealing member 24 is 2.0 to 5.2: 1 is preferable because the luminous efficiency is maintained high although it is slight. In consideration of robustness, a range in which the ratio of the diameter and height of the sealing member 24 is 5.2 to 7.8: 1 is preferable. For example, when the diameter is 4 mm and the height is 0.675 mm, the diameter / height ratio is 5.93. In this case, even if the diameter and the height are changed within a range of ± 0.1 mm, the variation in the ratio is 5.29 to 6.78, and the fluctuation is suppressed to be small.

  Table 1 shows the relationship between the shape of the sealing member and the light emission efficiency. In Table 1, “SMD” indicates a case where a sealing member containing a phosphor is poured into a cup-shaped recess. The “solid coating” is a case where the entire lower surface of the light source module 11 is covered with a sealing member including a phosphor in a planar shape. The “dome” is a case where a sealing member including a phosphor is formed in a substantially spherical shape as in this embodiment.

  In addition, in the structure of this embodiment, in order to discharge | release the heat | fever conducted from the light source module 11, it is preferable that the apparatus main body 2 containing the base wall part 3a is metal. The lower surface opening portion 4 of the apparatus main body 2 may remain open or may be covered with a translucent illumination cover 27 supported by the apparatus main body 2. In the latter case, the illumination cover 27 may be made of a transparent material, or may be made of a diffusible material that diffuses light emitted from the light source module 11 and makes the light emitting portion less noticeable.

  In the configuration of the present embodiment, a plurality of semiconductor light emitting elements (for example, blue LED 19) and non-light emitting electrical components (for example, electrical connector 35, capacitor 36, constant current diode 37) other than these elements are on the same surface of module substrate 14. Not placed. The electrical components are arranged on the back surface of the module board 14 in a positional relationship so as to overlap the arrangement area of the blue LEDs 19 arranged on the front surface of the module board 14. Therefore, the size of the module substrate 14 can be reduced as compared with the case where the blue LEDs 19 and the electrical components are arranged on the same surface of the module substrate 14. Therefore, it is advantageous when the lighting device 1 is downsized.

  Further, in this configuration, the arrangement of the plurality of blue LEDs 19 with respect to the front side surface of the module substrate 14 is affected by the arrangement of the electrical components, that is, the electrical connector 35, the capacitor 36, and the constant current diode 37 with respect to the back side surface of the module substrate 14. I do not receive it. That is, the blue LEDs 19 can be arranged in a substantially scattered manner on the entire area of the module substrate 14 without being affected by the arrangement of the electrical components. For this reason, the place which becomes dark by the arrangement | positioning of the said electrical component does not arise. As a result, the light source module 11 can emit light in a planar shape with uniform brightness.

  Further, in the above configuration, the light source module 11 is fixed to the apparatus main body 2 by passing the electric parts through the component through holes 3 d of the base wall 3 a of the apparatus main body 2 that supports the light source module 11. For this reason, the electrical component mounted on the back side of the light source module 11 is not hindered, and the back side surface of the module substrate 11 can be brought into close contact with the base wall 3a.

  While the lighting device 1 is turned on, each blue LED 19 generates heat. Most of this heat is transferred to the element mounting portion 15a and diffused in correspondence with the area of the element mounting portion 15a. This heat is transmitted from the element mounting portion 15 a through the front insulating layer 31 to the heat diffusion layer 33, and is diffused over the entire area of the module substrate 14 by the heat diffusion layer 33. Then, the heat is transmitted to the base wall 3 a that is in surface contact with the back side insulating layer 32 through the back side insulating layer 32, and is released to the outside from each part of the apparatus main body 2. In this case, as described above, the electrical components on the back surface side of the light source module 11 are not obstructed, and the back surface of the module substrate 14 is in close contact with the lower surface of the base wall portion 3a, which is a heat receiving surface. By this surface contact, good heat dissipation performance from the module substrate 14 to the apparatus main body 2 can be secured.

  As described above, since the heat of each blue LED 19 can be efficiently released to the metal device body 2 via the module substrate 14 having the thermal diffusion layer 33, the temperature increase of each blue LED 19 is suppressed, and each blue LED 19 It is possible to suppress a decrease in light emission efficiency and a change in light emission color in the LED 19.

  Further, in the above configuration, the module substrate 11 includes a front-side insulating layer 31 on which the blue LED 19 is mounted, a back-side insulating layer 32 on which the electrical component is mounted, and a size covering almost the entire area of the module substrate 14 and both insulating layers. And a thermal diffusion layer 33 provided between 31 and 32.

  With this configuration, a resin substrate such as a glass epoxy resin, a non-metallic substrate such as a paper phenolic material or a glass composite, or a substrate made of an inorganic material such as ceramic is used for the front-side insulating layer 31 and the back-side insulating layer 32. It is possible. At the same time, in the present invention, the thermal diffusion layer 33 can be formed of a metal layer, and can be preferably formed of, for example, a copper foil.

  In the configuration in which the base wall portion 3a as the heat receiving surface has the component through hole 3d for allowing the electrical component to escape, the heat dissipation performance in the region facing the component through hole 3d of the module substrate 14 is inferior to the others. However, in the above configuration, the module substrate 14 has the thermal diffusion layer 33 having a size covering substantially the entire area. For this reason, the heat released to the module substrate 14 from the semiconductor light emitting element (for example, the blue LED 19) mounted in the region facing the component through hole 3d is diffused throughout the module substrate 14 by the thermal diffusion layer 33, and the base wall portion 3a can be conducted and discharged to the outside. Such heat dissipation suppresses the temperature difference between the semiconductor light emitting elements, so that the color unevenness of the light source module 11 caused by the variation in the emission color of each semiconductor light emitting element can be suppressed.

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 2 ... Apparatus main body, 3a ... Base wall part, 4 ... Lower surface open part, 11 ... Light source module, 14 ... Module board | substrate, 14d ... Lower surface (front side surface) of a module board | substrate, 15 ... Metal conductor, 17 DESCRIPTION OF SYMBOLS ... Diffuse reflection layer, 17a ... Hole, 18 ... Light emission part, 19 ... Blue LED (semiconductor light emitting element), 19a ... Element board | substrate, 19b ... Light emission layer, 24 ... Sealing member, 27 ... Lighting cover.

Claims (5)

A module substrate;
A metal conductor provided in a predetermined pattern on the front surface of the module substrate;
A plurality of semiconductor light emitting elements electrically connected to the metal conductor and mounted on the front surface of the module substrate;
A white diffuse reflection layer having a plurality of holes in which the semiconductor light emitting elements are disposed, formed to be thinner than the thickness of the semiconductor light emitting elements, and laminated on the front surface of the module substrate;
A translucent sealing member embedded in the semiconductor light emitting element and projecting downward from the diffuse reflection layer and mixed with a phosphor;
A light source module comprising:   The light source module according to claim 1, wherein a tip of the semiconductor light emitting element protrudes downward from the diffuse reflection layer.   The light source module according to claim 1, wherein the sealing member is blocked by a hole of the diffuse reflection layer.   The light source module according to any one of claims 1 to 3, wherein the sealing member is formed in a substantially spherical shape having a diameter to height ratio of 2.0 to 7.8: 1. . A light source module according to any one of claims 1 to 4;
An apparatus body having a base wall portion and a lower surface opening portion below the wall portion, the light source module being fixed to the lower surface of the base wall portion;
A translucent illumination cover that closes the lower surface opening and covers the light source module from below and is supported by the apparatus body;
An illumination device comprising:

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