JP2008078047A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system suitable for maintaining emission efficiency and color rendition of a plurality of LED modules irradiating light on different irradiation objects. <P>SOLUTION: The lighting system 2 is provided with a plurality of the LED modules 11, 21 each having an LED. Each LED module 11, 21 is arranged in adjacency to each other so as to irradiate light on each different irradiation object. A heat insulating material 41 as an example is provided as a heat transfer suppressing means between the adjacent LED modules. With this heat insulating material 41, heat transfer between the LED modules 11, 21 is to be restrained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an illuminating device including a plurality of light emitting units that illuminate mutually different irradiation targets, and these light emitting units are formed of LED modules having LEDs (light emitting diodes).

  2. Description of the Related Art Conventionally, there has been known an illuminating device that irradiates light upward and downward using two straight tube fluorescent lamps forming a light source (see, for example, Patent Document 1).

  In the illuminating device of Patent Document 1, an apparatus main body that is mounted apart from the ceiling surface is provided with an upper light irradiation opening that opens upward and a lower light irradiation opening that opens downward, and this apparatus main body The upper and lower straight tube fluorescent lamps are internally provided with a first reflector that reflects downward light from the upper straight tube fluorescent lamp toward the upper light irradiation port, and the lower straight tube fluorescent lamp. The apparatus main body is internally provided with a second reflecting plate that reflects upward light from the lamp toward the lower light irradiation port.

  On the other hand, instead of a straight tube fluorescent lamp in the light source part, in a lighting fixture using an LED unit using an LED as a light source, it is thermally connected to a metal cover in order to release the heat generated by the LED to the outside. A technology is known in which an LED substrate on which a plurality of LEDs are mounted on one surface of a mounting plate having high thermal conductivity, such as aluminum, is screwed by sandwiching a heat conductive sheet between the substrate and the one surface. (For example, refer to Patent Document 2).

In the lighting fixture of Patent Document 2, the heat generated by the LED unit including the LED is conducted to the mounting plate through the heat conductive sheet, and is conducted from the mounting plate to the lighting fixture cover, and heat is radiated from the cover to the outside. Can be made.
JP 2003-217335 A (paragraphs 0033-0038, FIGS. 15 to 16) JP 2006-172893 A (paragraphs 0014-0030, FIGS. 1 to 3)

  The illumination device described in Patent Document 1 can perform ambient illumination in which light is emitted upward and downward by two straight tube fluorescent lamps arranged adjacent to each other in the vertical direction. No heat countermeasures are taught for the straight tube fluorescent lamp of the book.

  When the temperature of the plurality of LEDs included in the LED unit increases excessively due to the self-heating, the light emission efficiency is lowered and the color rendering property of the emitted light cannot be maintained. However, the lighting fixture of Patent Document 2 is a single LED unit whose light source section uses a plurality of LEDs as light sources, and irradiates light only in the downward direction. That is, a plurality of LED units are not arranged to irradiate light to different irradiation targets. Therefore, even though it is described in Patent Document 2 to ensure the heat dissipation of the LED unit, the technology for heat countermeasures in a lighting device using a plurality of LED units each irradiating light to different irradiation objects is patented. Document 2 does not teach it.

  The objective of this invention is providing the illuminating device suitable for maintaining the luminous efficiency and color rendering of the several LED module which irradiates light to different irradiation object.

  The invention of claim 1 includes a plurality of LED modules having LEDs, and these LED modules are arranged adjacent to each other so as to irradiate light to different irradiation objects, and heat transfer between the adjacent LED modules is performed. The heat transfer suppressing means for suppressing is provided between the adjacent LED modules.

  In the present invention, typical examples of different irradiation targets include a ceiling surface and a floor surface. However, for example, wall surfaces facing each other may be used, and thus irradiation of light to different irradiation targets is possible. Can be realized by arranging a plurality of, for example, two LED modules in a back-to-back state. In the present invention and the following invention, the heat transfer suppressing means can be formed of a heat insulating material or a gap that suppresses heat transfer due to heat conduction from one of the adjacent LED modules to the other. .

  In the first aspect of the invention, the heat transfer suppression means provided between the adjacent LED modules can suppress the heat transfer between the adjacent LED modules, thereby preventing the thermal interference between the adjacent LED modules. . Thereby, since each temperature of the several LED module which irradiates light to different irradiation object is maintained as designed, the light emission efficiency and color rendering property of LED which each adjacent LED module has can be maintained. .

  The invention of claim 2 comprises an upper LED module that has an LED and emits light upward; a lower LED module that has an LED and is arranged near the lower portion of the upper LED module and emits light downward; And a heat transfer suppressing means provided between the upper and lower LED modules for suppressing heat transfer between the upper and lower LED modules.

  According to the second aspect of the present invention, the heat transfer suppressing means provided between the vertically adjacent LED modules suppresses heat transfer between the upper and lower LED modules and prevents thermal interference between the upper and lower LED modules. it can. As a result, the individual temperatures of the upper and lower LED modules that irradiate light on the upper or lower irradiation target are maintained as designed, so that the luminous efficiency and color rendering of the LEDs of the adjacent LED modules are maintained. can do.

  The invention according to claim 3 is provided with a spacer sandwiched between the upper LED module and the lower LED module by a module substrate provided in the LED module, and by this spacer, a gap functioning as the heat transfer suppressing means is provided. It is characterized by being provided between the upper and lower LED modules in communication with the outside of the upper LED module.

  In this invention of Claim 3, the heat transfer between the upper and lower LED modules is suppressed by the gap formed between the upper and lower LED modules by the spacer sandwiched between the upper and lower adjacent LED modules, and the upper and lower LED It is possible to prevent thermal interference between modules. In this case, since the air gap communicates with the outside of the upper LED module, the air in the air gap is replaced by convection so that heat does not accumulate in the air gap. It can be prevented from being heated. Accordingly, the individual temperatures of the upper and lower LED modules that irradiate light on the upper or lower irradiation target are maintained as designed, so that the luminous efficiency and color rendering of the LEDs of the adjacent LED modules are maintained. be able to.

In addition, when forming a spacer with a heat insulating material in invention of Claim 3, it is preferable at the point which can prevent the heat transfer which uses this spacer as a path | route, but it is lower than the heat conductivity of the module board | substrate with which an LED module is equipped. Thermal conductivity spacers can be used. At the same time, when the thermal conductivity of the spacer is substantially the same as the thermal conductivity of the module substrate, a heat insulating material sheet can be sandwiched between the spacer and the module substrate. In the invention of claim 3, in the configuration in which a blowing element such as a small fan that intentionally ventilates the air gap is added, the air gap can be used as a heat dissipation space. Further, in the invention of claim 3, it is not disturbed to provide a ventilation portion such as a ventilation hole communicating with the air gap on at least the module substrate provided in the upper LED module. The configuration in which the ventilation portion is provided in this manner is preferable in that convection of air passing through the gap can be promoted by exhaust from the ventilation portion.

  According to a fourth aspect of the present invention, a metal louver that controls light distribution of light emitted from the LEDs of the lower LED module is provided on the lower surface of the module substrate of the lower LED module so as to be thermally conductive. It is a feature.

  In the invention of claim 4, the louver that defines the shielding angle of the light emitted downward can be used as a heat radiating member, and the heat generated by the LEDs of the lower LED module is conducted from the module substrate of the lower LED module to the louver. Can be released to the outside.

  According to invention of Claim 1, the illuminating device suitable for maintaining the light emission efficiency and color rendering property of several LED module which irradiates light to different irradiation object can be provided.

  According to the invention of claim 2, it is possible to provide a lighting device suitable for maintaining the luminous efficiency and color rendering of the upper and lower LED modules that irradiate light on the upper or lower irradiation target.

  According to the invention of claim 3, since the space between the LED modules adjacent to each other in the upper and lower sides is used to prevent thermal interference between the upper and lower LED modules, the upper or lower irradiation target is irradiated with light. Thus, it is possible to provide a lighting device suitable for maintaining the luminous efficiency and color rendering of the upper and lower LED modules.

  According to the invention of claim 4, the heat generated by the LEDs of the lower LED module is released to the outside from the louver that defines the shielding angle of the light emitted downward, and the heat of the lower LED module is caused to the upper LED module. Since it is difficult to spread, it is possible to provide a lighting device suitable for maintaining the luminous efficiency and color rendering of the upper and lower LED modules that irradiate light on the upper or lower irradiation target.

  A first embodiment of the present invention will be described with reference to FIGS.

  Reference numeral 1 in FIG. 1 indicates a hanging type lighting fixture that performs ambient lighting. The luminaire 1 includes an illuminating device 2 and a plurality of suspending members 4 that suspend and install the illuminating device 2 on a ceiling surface 3.

  As shown in FIG. 1, the lighting device 2 includes an upper LED module 11 that emits light upward, a lower LED module 21 that emits light downward, a heat transfer suppressing means such as a heat insulating material 41, and a louver 51. is doing.

  The upper LED module 11 is formed by mounting a plurality of LEDs 13 in a predetermined arrangement on the upper surface of the module substrate 12 and attaching a light distribution control member such as a lens 14 disposed for each of the LEDs 13.

  The module substrate 12 is made of a printed wiring board. Since the module substrate 12 also functions as a member that dissipates heat from the surface, an insulating layer is laminated on one surface of the metal base, and a conductor portion is formed in a predetermined pattern on the insulating layer by a printed wiring technique. It is preferable to use a printed wiring board.

  Each LED 13 emits white light. The electrodes (not shown) of these LEDs 13 and the conductors of the module substrate 12 are connected by bonding wires. The LEDs 13 are connected in series, parallel, or series-parallel through these conductors and bonding wires, and are electrically connected to a lighting device (not shown).

  Each lens 14 is a molded product of translucent synthetic resin, and has an exit surface on the side opposite to the recess for housing the LED 13, and the inner surface of the recess is formed by a lens surface, and the opening end of the recess and the exit surface And is made through a reflective surface. The reflecting surface of the lens 14 is designed so that the light emitted from the LED 13 in the recess is emitted from the emitting surface. As shown in FIGS. 1 and 2, each lens 14 is integrally and continuously formed as a single lens body, and this lens body is mounted and held on the module substrate 12 by an appropriate holding means (not shown). In the present invention, the light distribution control member including the lens 14 and the like may be omitted.

  As shown in FIG. 1, the lower LED module 21 is formed by mounting a plurality of LED units 23 in a predetermined arrangement on the lower surface of the module substrate 22.

  The module substrate 22 functions as a member that radiates heat from the surface thereof, and is made of a metal flat plate. The module substrate 22 is substantially the same size as the module substrate 12 of the upper LED module 11.

  The configuration of each LED unit 23 will be described with reference to FIG. The LED unit 23 includes a unit substrate 24, a reflective layer 25, a circuit pattern 26, a plurality of LEDs 27, a reflector 28, and a sealing member 29.

  The unit substrate 24 is made of a flat plate made of metal or synthetic resin. The reflective layer 25 is made of a white insulating material and is laminated on the entire lower surface of the unit substrate 24. The reflective layer 25 is formed of a prepreg made of a sheet-like adhesive material. A plurality of circuit patterns 26 are bonded to the reflective layer 25 and provided at predetermined intervals. Each LED 27 is arranged alternately with the circuit pattern 26, and is adhered to the reflective layer 25 using a translucent adhesive 30. The circuit pattern 26 and the LEDs 27 are connected in series by bonding wires 31 and are electrically connected to a lighting device (not shown). The reflector 28 is formed in a frame shape with a white material, and accommodates the circuit pattern 26, the LED 27, and the like on the inside thereof, and is bonded and fixed to the reflective layer 25. The sealing member 29 is made of a translucent synthetic resin or the like, and is filled with the circuit pattern 26, the LED 27, etc., and injected into the reflector 28 to be solidified.

  Each LED 27 is formed by laminating a semiconductor light emitting layer 27 b on one surface of a light-transmitting sapphire element substrate 27 a, and the other surface of the element substrate 27 a is bonded to the reflective layer 25. The semiconductor light emitting layer 27b can emit blue light both in the thickness direction (vertical direction). Although not shown, the phosphor (fluorescent substance) is mixed in the sealing member 29 in a substantially uniformly dispersed state as a preferred example. As the phosphor, a phosphor that emits yellow light as secondary light having a different wavelength by converting the wavelength of blue primary light emitted from the LED 27 is used. The combination of the phosphor that emits yellow light and the LED 27 that emits blue light allows part of the blue light emitted from the semiconductor light emitting layer 27b to pass through the sealing member 29 without hitting the phosphor, while the semiconductor light emitting layer The phosphor that is irradiated with the blue light emitted from 27b absorbs the blue light and emits yellow light, and the yellow light passes through the sealing member 29. As a result, white light is formed and emitted downward. In addition, by adding a phosphor that converts the wavelength of blue primary light emitted from the LED 27 and emits red light to the sealing member 29, white light with enhanced color rendering properties is emitted downward. Also good.

  As shown in FIG. 1, the upper LED module 11 and the lower LED module 21 provided in the vicinity of the lower side are disposed adjacent to each other vertically with a heat insulating material 41 interposed therebetween. The heat insulating material 41 is used as a means for making the upper LED module 11 and the lower LED module 21 thermally independent, and is composed of a flat plate having approximately the same size as the two modules. Therefore, the module substrate 12 of the upper LED module 11 is in surface contact with the upper surface of the heat insulating material 41, and the module substrate 22 of the lower LED module 21 is in surface contact with the lower surface of the heat insulating material 41.

  The upper LED module 11, the lower LED module 21, and the heat insulating material 41 are connected and integrated by a connecting means (not shown). This connection can be performed by using an adhesive, or by using bolts and nuts. When bolts and nuts are used, heat insulation is provided between the bolt head and the upper surface of the module substrate 12 or the lower surface of the module substrate 22, or between the nut and the upper surface of the module substrate 12 or the lower surface of the module substrate 22. It is recommended to insert a washer made of material and fasten with bolts and nuts. In place of this, a cylinder made of a heat insulating material having a flange corresponding to the washer at one end is inserted into a hole through which the bolt passes, and then tightened with a bolt and a nut. By taking such heat insulation measures, it is possible to prevent the bolts and nuts from becoming a heat transfer path between the module substrate 12 and the module substrate 22. And the said suspension member 4 is connected to the four corners of the assembly of the upper LED module 11, the lower LED module 21, and the heat insulating material 41 assembled as mentioned above.

  The louver 51 is formed by combining louver pieces made of a metal having excellent thermal conductivity such as an aluminum alloy in a grid pattern as shown in FIGS. The wall thickness of the louver piece is tapered from the root formed by the upper end of the louver piece toward the tip (lower end). The height of the louver 51 is larger than the thickness of the lower LED module 21.

  The louver 51 is attached so that the base of the louver piece is in contact with the lower surface of the module substrate 22 so as to conduct heat. Although not shown, this attachment is performed using, for example, a heat conductive adhesive or a screw screwed from the upper side of the module substrate 22. The lower LED modules 21 are individually arranged in each of a plurality of square spaces formed by the louver pieces of the louver 51 that are continuous with each other. In other words, the periphery of each of the plurality of lower LED modules 21 is surrounded by each louver piece.

  The louver 51 controls the light distribution of the light emitted downward from the lower LED module 21, and defines, for example, the light blocking angle θ (see FIG. 1) of the light emitted downward. The light shielding angle θ is 60 °, for example. Thereby, while reflecting the lower LED module 21 to the display screen installed under the lighting fixture 1, it suppresses giving a glare to a user.

  The illuminating device 2 configured as described above uses the LEDs 13 and 27 as the light emitting elements, and thus the upper LED module 11 and the lower LED module 21 having these are combined so as to overlap each other vertically. Compared with the case where a fluorescent lamp is used for the part, the thickness of the entire lighting device 2 is reduced, and the lighting fixture 1 can be made thinner accordingly. For this reason, as the hanging height of the lighting fixture 1 with respect to the ceiling surface 3 can be shortened, even when the ceiling is used in an office environment where the ceiling is low, it is possible to reduce the feeling of foreign objects due to the lighting fixture 1 at the ceiling.

  Ambient illumination is performed by turning on the installed illumination device 2. In this illumination, light emitted from each LED 13 of the upper LED module 11 is emitted toward the ceiling surface 3 through the lens 14, and light emitted from each LED 27 of the lower LED module 21 controls light distribution by the louver 51. And emitted downward.

  During this lighting, each LED 13 of the upper LED module 11 and each LED 27 of the lower LED module 21 self-heats. The heat generated by each LED 13 is released by conducting heat to the module substrate 12 of the upper LED module 11 and further released from the upward surface of the module substrate 12 into the atmosphere. It is suppressed. Similarly, the heat generated by each LED 27 is released by conducting heat to the module substrate 22 of the lower LED module 21 and is further released into the atmosphere from the downward surface of the module substrate 22. Temperature rise is suppressed.

  By the way, the upper LED module 11 that irradiates the ceiling surface 3 and the lower LED module 21 that irradiates the lower part of the lighting device 2 are designed so that illumination suitable for each irradiation target can be performed. The amount of heat generated by the LED 27 is often different.

  However, the module substrate 12 of the upper LED module 11 and the module substrate 22 of the lower LED module 21 that are arranged adjacent to each other so that the rear surfaces are aligned vertically are directly heated by the heat insulating material 41 sandwiched therebetween. It can not conduct. For this reason, even if the temperatures of the module substrates 12 and 22 are different, the heat insulating material 41 can prevent the heat transfer that averages them from occurring between the module substrates 12 and 22.

  As a result, it was confirmed by experiments that the temperature of the upper module substrate 12 can be maintained at 60 ° C., and the temperature of the lower module substrate 22 can be maintained at 85 ° C. On the other hand, in the configuration of the comparative example in which the module substrates 12 and 22 are directly contacted without using the heat insulating material 41, the temperature of the upper module substrate 12 rises to 70 ° C., and the temperature of the lower module substrate 22 It was confirmed by experiment that the temperature dropped to 75 ° C. However, the above experiment was conducted without the louver 51.

  When the heat of the lower module substrate 22 increases the temperature of the upper module substrate 12 as in the comparative example, as a result, the temperature of each LED 13 mounted on the module substrate 12 increases. For this reason, the light emission efficiency of each LED 13 is lowered, the life of each LED 13 is reduced, and the color rendering properties of the light emitted by the LEDs 13 are slightly varied due to variations in the temperatures of the LEDs 13.

  On the other hand, in the illuminating device 2 of the present embodiment in which the heat transfer between the module substrates 12 and 22 is suppressed using the heat insulating material 41, the thermal interference between the module substrates 12 and 22 can be suppressed. 27 can be easily maintained as designed, so that the temperature of each upper LED 13 does not rise too much. Therefore, it is possible to suppress a decrease in light emission efficiency of each LED 13 and a variation in color rendering properties of light emitted from each LED 13. In addition, since the upper LED module 11 and the lower LED module 21 are thermally independent as described above, it is not necessary to consider the thermal interference described above when designing the heat dissipation characteristics of the lighting device 2. Therefore, the upper LED module 11 and the lower LED module 21 are regarded as independent light sources, and a suitable heat radiation design can be facilitated.

  In the illumination device 2, the louver 51 that defines the light blocking angle θ of the light emitted downward from the lower LED module 21 is made of metal and is connected to the lower surface of the module substrate 22 so as to be thermally conductive. The heat generated by each of the LEDs 27 can be conducted from the module substrate 22 to the louver 51 which is a light distribution control component, and the louver 51 can be released to the outside as a heat radiating member.

  Thereby, since the temperature rise of the lower LED module 21 can be suppressed, the fall of the luminous efficiency of the LED27 can be suppressed. At the same time, the heat of the lower LED module 21 is more difficult to spread to the upper LED module 11. Therefore, the luminous efficiency and color rendering of the upper LED module 11 that irradiates light on the ceiling surface 3 that is the upper irradiation target, and the lower LED module 21 that irradiates light to the lower space of the illumination device 2 that is the lower irradiation target. Suitable for maintaining. Furthermore, since the louver 51 is used as a heat radiating member, there is no need for a dedicated part for increasing heat radiation and a space for arranging this part. Thereby, while being able to simplify the structure of the illuminating device 2, it can also avoid that the illuminating device 2 becomes large.

  A second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment in the configuration of the lighting device 102 included in the hanging type lighting fixture 1 that performs ambient lighting, and the other parts are the same as those in the first embodiment. The same reference numerals are given and description thereof is omitted.

  As shown in FIG. 5, the illumination device 102 includes an upper LED module 111 that emits light upward, a lower LED module 121 that emits light downward, and a gap G as a heat transfer suppression unit formed by a spacer 140. It has.

  The upper LED module 111 is formed by mounting a plurality of LEDs 13 in a predetermined arrangement on the upper surface of the module substrate 12.

  The module substrate 12 is made of a flat plate of a printed wiring board having a predetermined shape such as a square. Since the module substrate 12 also functions as a member that dissipates heat from the surface, an insulating layer 12b is provided on the upper surface of the metal base 12a, and a conductor portion is formed in a predetermined pattern on the insulating layer 12b by a printed wiring technique. It is preferable to use the printed wiring board. In a region excluding the peripheral portion of the module substrate 12, a ventilation portion, for example, a plurality of ventilation holes 142 penetrating vertically is provided to avoid the LEDs 13 that emit white light.

  The electrode of each LED 13 that emits white light and the conductor portion of the module substrate 12 are connected by a bonding wire. The LEDs 13 are connected in series, parallel, or series-parallel through these conductors and bonding wires, and are electrically connected to a lighting device (not shown).

  The lower LED module 121 is formed by mounting a plurality of LEDs 143 in a predetermined arrangement on the lower surface of the module substrate 22. The LEDs 143 of the lower LED module 121 are used more frequently than the LEDs 13 of the upper LED module 111 and are arranged in a wide range.

  The module substrate 22 is made of a flat plate of a printed wiring board having a predetermined shape such as a square. The module substrate 22 is larger than the module substrate 12 of the upper LED module 111, for example, and has a similar shape to the module substrate 12. Since the module substrate 22 also functions as a member that dissipates heat from the surface, an insulating layer 22b is provided on the lower surface of the metal base 22a, and a conductor portion is formed in a predetermined pattern on the insulating layer 22b by a printed wiring technique. It is preferable to use the printed wiring board.

  The electrode of each LED 143 that emits white light and the conductor portion of the module substrate 22 are connected by a bonding wire. The LEDs 143 are connected in series, parallel, or series-parallel via these conductors and bonding wires, and are electrically connected to a lighting device (not shown).

  The upper LED module 111 is disposed near the upper part of the center of the lower LED module 121 with the metal base 12a facing downward and the metal base 22a facing upward. A plurality of, for example, a pair of spacers 140 having a rod shape are sandwiched therebetween. The spacer 140 forms a gap G between the upper LED module 111 and the lower LED module 121 that functions as a heat transfer suppression unit that suppresses heat transfer between the upper LED module 111 and the lower LED module 121. .

  The gap G is formed by being surrounded by the upper LED module 111, the lower LED module 121, and the pair of spacers 140. The gap G communicates with the outside of the upper LED module 111 through a portion where the spacer 140 is not provided so that outside air can flow. Each ventilation hole 142 communicates with the gap G. The module substrate 22 of the lower LED module 121 may be provided with a vent hole that communicates with the gap G while avoiding the LEDs 143.

  The spacer 140 is configured to thermally separate the upper LED module 111 and the lower LED module 121, i.e., a heat transfer path extending between the upper LED module 111 and the lower LED module 121 disposed adjacent to each other in the vertical direction. It is preferable to form with a heat insulating material so that it may not become.

  The spacer 140, the upper LED module 111, and the lower LED module 121 are connected by a connecting means (not shown). This connection can be performed by using an adhesive, or by using screws or bolts and nuts. When connecting using screws, it is only necessary to insert screws downward from the upper LED module 111 into the spacer 140 and screws upward from the lower LED module 121. At this time, the upward screw and the downward screw are It is desirable to screw them out of position so that they do not become heat transfer paths. When connecting with bolts and nuts, between the head of the bolt and the upper surface of the module substrate 12 or the lower surface of the module substrate 22, or between the nut and the upper surface of the module substrate 12 or the lower surface of the module substrate 22. It is advisable to insert a washer made of a heat insulating material into one of them and fasten it with bolts and nuts. In place of this, a cylinder made of a heat insulating material having a flange corresponding to the washer at one end is inserted into a hole through which a bolt passes, and then tightened with a bolt and a nut. By taking such heat insulation measures, it is possible to prevent the bolts and nuts from becoming a heat transfer path between the module substrate 12 and the module substrate 22. The suspension member 4 is connected to the four corners of the assembly of the upper LED module 111, the lower LED module 121, and the heat insulating material 41 assembled as described above.

  Ambient illumination is performed by turning on the lighting device 102 installed suspended from the ceiling surface 3. In this illumination, light emitted from each LED 13 of the upper LED module 111 is emitted toward the ceiling surface 3, and light emitted from each LED 143 of the lower LED module 121 is emitted downward.

  During this lighting, each LED 13 of the upper LED module 111 and each LED 143 of the lower LED module 121 self-heats. The heat generated by each LED 13 is released by conducting heat to the module substrate 22 of the upper LED module 111, and further released from the module substrate 22 into the atmosphere, so that the temperature rise of each LED 13 is suppressed. Similarly, the heat generated by each LED 143 is released by conducting heat to the module substrate 22 of the lower LED module 121, and further released from the module substrate 22 into the atmosphere, so that the temperature rise of each LED 143 is suppressed. Is done.

  In the illumination device 102, the lower LED module 121 generates more heat than the upper LED module 111 due to the difference in the number of mounted LEDs. However, the module substrate 12 of the upper LED module 111 and the module substrate 22 of the lower LED module 121 that are arranged adjacent to each other so that the back faces are mainly insulated by the gap G so that direct heat conduction is not possible. In addition, the spacer 140 made of a heat insulating material sandwiched between the module substrates 12 and 22 is also insulated.

  Therefore, heat transfer that averages the temperatures of the module substrates 12 and 22 is prevented from occurring between the module substrates 12 and 22. In other words, the heat of the lower LED module 121 that generates a large amount of heat is transmitted to the upper LED module 111 that generates less heat than the lower LED module 121, and the temperature of the upper LED module 111 is prevented from being raised.

  In this case, since the gap G is open in the front and back direction of the drawing of FIG. 5 and communicates with the outside of the upper LED module 111, the air in the gap G is replaced by convection and heat is generated in the gap G. You can keep it from being trapped. Moreover, in the present embodiment, the air in the gap G is also discharged to the outside through the plurality of vent holes 142 provided in the upper LED module 111, so that the replacement of air into the gap G can be promoted. This prevents the upper LED module 111 from being heated by the lower LED module 121 through the gap G.

  Furthermore, the lower LED module 121 of the lighting device 102 is larger than the upper LED module 111, and when the lighting device 102 is viewed from the ceiling surface 3 side, the upper LED module 111 is projected onto only a part of the lower LED module 121. Therefore, it is possible to suppress the upper LED module 111 from being exposed to the heat emitted from the other areas of the lower LED module 121 deviated from the projected area, so that the upper LED module 111 is heated. The temperature rise of the LED module 111 is further suppressed.

  As a result of the above, the temperature rise of each LED 13 mounted on the module substrate 12 is suppressed, and the temperature of each of the upper and lower LEDs 13 and 143 can be maintained as designed. Variations in the color rendering properties of the light emitted by each LED 13 can be suppressed.

  In addition, since the upper LED module 111 and the lower LED module 121 are thermally independent as described above, it is not necessary to consider the above-described thermal interference when designing the heat dissipation characteristics of the lighting device 102. Therefore, the upper LED module 111 and the lower LED module 121 are regarded as independent light sources, and a suitable heat radiation design can be facilitated. And depending on the case, it can also be used as an independent light source for every LED module. In addition, since the heat radiation area of the lower LED module 121 is made larger than that of the upper LED module 111 as described above, a decrease in luminous efficiency of the LED 143 can be suppressed as the temperature increase of the lower LED module 121 is effectively suppressed. .

  A third embodiment of the present invention will be described with reference to FIG. The third embodiment is different from the second embodiment in the configuration of the lighting device 102 included in the hanging type lighting fixture 1 that performs ambient lighting, and the other parts are the same as those in the second embodiment. The same reference numerals are given and description thereof is omitted.

  In the third embodiment, when the illumination device 102 is viewed, it protrudes upward from the upper surface of this region, for example, to another region of the lower LED module 121 that is out of the projection region of the upper LED module 111 with respect to the lower LED module 121. A heat dissipating element 22c thermally connected to the metal base 22a is provided. The heat dissipation element 22c is preferably formed integrally with the metal base 22a. The heat dissipation element 22c is made of, for example, a plurality of ribs or fins.

  Since the configuration other than the items described above is the same as that of the second embodiment, the same operation as that of the second embodiment can be obtained also in the third embodiment. Therefore, the illumination device 102 according to the third embodiment includes an upper LED module 111 that irradiates light on the ceiling surface 3 that is an irradiation target, and a lower LED module 121 that irradiates light below the illumination device 102 that is the irradiation target. It is suitable for maintaining the light emission efficiency and color rendering properties.

  Moreover, in the third embodiment, since the heat dissipation area is increased by providing the heat dissipation element 22c in the lower LED module 121, heat dissipation from the lower LED module 121 is promoted. Along with this, the temperature rise of the lower LED module 121 is more effectively suppressed, which is advantageous in that the decrease in the light emission efficiency of the LED 143 can be further suppressed.

Sectional drawing which shows the lighting fixture provided with the illuminating device which concerns on 1st Embodiment of this invention. The top view which shows the illuminating device of FIG. Sectional drawing which expands and shows a part of LED unit of the lower LED module with which the illuminating device of FIG. 1 is provided. The bottom view which shows the illuminating device of FIG. Sectional drawing which shows the lighting fixture provided with the illuminating device which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the lighting fixture provided with the illuminating device which concerns on 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Lighting fixture, 2,102 ... Lighting apparatus, 3 ... Ceiling surface (irradiation object) 11, 111 ... Upper LED module, 12a, 22a ... Metal base, 13 ... LED of upper LED module, 21, 121 ... Lower LED Module, 27 ... LED of lower LED module, 41 ... Heat insulating material (heat conduction suppressing means), 51 ... Louver, 140 ... Spacer, 143 ... LED of lower LED module, G ... Air gap (heat conduction suppressing means)

Claims (4)

  A plurality of LED modules each having an LED, the LED modules being arranged adjacent to each other so as to irradiate light to different irradiation objects, and heat transfer suppressing means for suppressing heat transfer between the adjacent LED modules; An illumination device provided between the adjacent LED modules. An upper LED module having LEDs and emitting light upward;
A lower LED module which has an LED and is arranged near the lower part of the upper LED module and emits light downward;
Heat transfer suppression means provided between the upper and lower LED modules to suppress heat transfer between the upper and lower LED modules;
An illumination device comprising:   A spacer is provided between the upper LED module and the lower LED module so as to be sandwiched between the module substrates included in the LED modules, and this spacer allows a gap functioning as the heat transfer suppressing means to be outside the upper LED module. The lighting device according to claim 2, wherein the lighting device is provided between the upper and lower LED modules so as to communicate with each other.   The metal louver for controlling the light distribution of the light emitted from the LEDs of the lower LED module is provided to be connected to the lower surface of the module substrate of the lower LED module so as to be able to conduct heat, or 3. The lighting device according to 3.

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