JP5263516B2 - Light source unit and lighting apparatus - Google Patents

Description

  The present invention relates to a light source unit suitable for a lighting fixture using a light emitting element such as an LED, and a lighting fixture using the light source unit.

  In recent years, lighting fixtures that use light emitting elements such as LEDs as light sources have been developed. With the increase in brightness and output, the number of LEDs used has increased, and the substrate on which the LEDs are mounted has become larger. Yes. A light emitting element such as an LED affects the life as well as the light output as the temperature rises. For this reason, in the lighting fixture which uses solid light emitting elements, such as LED and an EL element, as a light source, in order to improve various characteristics of a lifetime and efficiency, it is necessary to suppress the temperature rise of a light emitting element.

  In addition, the substrate on which the LED or the like is mounted tends to have a high temperature at the center of the substrate, particularly in the early stage of lighting. Therefore, as lighting and extinguishing are repeated, the temperature at the beginning of lighting influences, leading to a decrease in the life and various characteristics of the light emitting element mounted on the central part of the substrate. Inconveniences such as darkening of the light emitting element mounted on the substrate occur. On the other hand, the heat at the central portion of the substrate is difficult to dissipate and the temperature is likely to rise even during stable lighting, regardless of the initial lighting of the light source. Therefore, with this kind of lighting equipment with higher brightness and higher output, that is, with the increase in generated heat and the increase in size of the substrate, there is an increasing demand for improvement in heat dissipation performance and temperature uniformity of the substrate.

2. Description of the Related Art Conventionally, there has been proposed a lighting fixture using an LED as a light source that can be downsized and improve heat dissipation performance (see Patent Document 1). This lighting fixture forms the recessed part by which the opening part was provided in the side wall in the other end part of the instrument main body, and thermally radiates effectively by the external air which flows through an instrument main body and this recessed part.
JP 2008-186776 A

  However, although the viewpoint of improving the heat dissipation performance is shown in Patent Document 1, it is not configured to satisfy both the demands of improving the heat dissipation performance and soaking the substrate at the same time. In particular, nothing has been disclosed about the soaking of the substrate.

  This invention is made | formed in view of the said subject, and it aims at providing the lighting fixture using the light source unit which can accelerate | stimulate both heat dissipation performance and soaking | uniform-heating of a board | substrate, and the light source unit.

The light source unit according to claim 1 is provided with a substrate on which a plurality of light emitting elements are mounted in the central portion and the peripheral portion thereof; facing the back side of the substrate and being thermally coupled to the substrate; A main radiating fin that forms a plurality of grooves between the peripheral portions at the center on the back side, and is disposed on both sides of the main radiating fin and is in a direction perpendicular to the main radiating fin and the outermost main radiating heat A sub-radiation fin that forms a plurality of grooves so as to face the fin, and the height dimension of the outermost main radiation fin is at least substantially equal to the height dimension of the groove formed by the sub-radiation fin And a heat radiating means formed .

  In the present invention and the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified. A light emitting element is solid light emitting elements, such as LED and organic EL. The light emitting element is preferably mounted by a chip-on-board method or a surface mounting method, but the mounting method is not particularly limited due to the nature of the present invention. There are no particular restrictions on the number of light emitting elements mounted or the shape of the substrate. The central part and the peripheral part are not uniform. This is a relative concept grasped by the arrangement form of the substrate and the light emitting elements. Being thermally coupled to the substrate also allows direct contact with the substrate or indirectly thermally conductive. The term “between peripheral edges” includes the outermost edge of the edge, but is not limited to the outermost edge, and means a region having a predetermined width. The heat radiating means includes a so-called heat sink, an instrument body, a case or a cover. The heat radiating fins increase the surface area of the heat radiating means, and a plurality of grooves may be formed, and the shape, arrangement, and the like are not particularly limited. For example, the main radiating fins may be formed continuously in the region between the peripheral portions in the longitudinal direction, or may be divided into a plurality of blocks and partially formed. Furthermore, the main heat radiating fins and the sub heat radiating fins may be partially or entirely integrally formed.

  According to a second aspect of the present invention, there is provided a lighting fixture comprising: the light source unit according to the first aspect; and a power supply unit attached to a sub-radiating fin of the light source unit.

  According to the first aspect of the present invention, it is possible to provide a light source unit that can improve heat dissipation and promote soaking.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, since the power supply unit is attached to the sub-radiating fin, the influence of heat acting on the power supply unit can be reduced. Possible lighting fixtures can be provided.

  Hereinafter, a light source unit and a lighting fixture according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial cross-sectional view showing a lighting fixture, FIG. 2 is a top view thereof, FIG. 3 is a bottom view thereof, FIG. 4 is a perspective view showing a reflector, and FIG. It is explanatory drawing which shows the state.

  In FIG. 1 to FIG. 3, a ceiling-embedded downlight 1 is shown as a lighting fixture. The downlight 1 includes a light source unit 2 and a power supply unit 3 attached to the light source unit 2. The light source unit 2 includes a heat conductive heat dissipating means 4, a decorative frame 5 attached to the heat dissipating means 4, a substrate 7 which is also attached to the heat dissipating means 4 and mounted with LEDs 6 as light emitting elements, a reflector 8 and a translucent cover 9 disposed in front of the reflector 8.

The heat dissipating means 4 is a so-called heat sink and is formed of a material having good heat conductivity made of aluminum die casting, and its outer surface is baked and coated with a white melamine resin-based paint. Of course, other materials may be used as long as thermal conductivity can be ensured. The heat dissipating means 4 includes a substantially disc-shaped base 41 and a plurality of heat dissipating fins 42 erected on the back side of the base 41. Further, the heat dissipating fins 42 are the main heat dissipating fins 42M. And a block of sub-radiating fins 42S. The main radiating fins 42M are formed in a plan view and a straight line so as to extend between the peripheral portions of the base 41, and are formed to protrude in a substantially rectangular shape in a side view and between the main radiating fins 42M. Is formed. On the other hand, on both sides of the main radiating fin 42M, a plurality of sub radiating fins 42S projecting from the peripheral edge of the base 41 toward the main radiating fin 42M are formed so as to be orthogonal to the main radiating fin 42M. Similarly, a groove 43S is formed between the sub-radiating fins 42S.
Further, the groove 43S of the sub-radiation fin 42S is formed so as to face the outermost main radiating fin 42Mo, and the height of the outermost main radiating fin 42Mo is formed by the sub-radiating fin 42S. It is formed at least approximately equal to the height dimension of the groove 43S.

  The decorative frame 5 is formed of an ABS resin or aluminum die-cast in a substantially umbrella shape, an annular flange 51 is formed at the end of the divergent opening, and the other end is attached to the heat dissipation means 4. Yes. In addition, the decorative frame 5 is mounted with a member 10 for attachment to a ceiling surface or the like at intervals of 120 degrees (not shown in FIGS. 1 and 5).

  On the surface side of the substrate 7, a plurality of LEDs 6 serving as light sources are mounted in a surface mounting manner, specifically, three in the center, six in the periphery, and 12 in the periphery. (See FIG. 3). The substrate 7 is made of a substantially circular flat plate made of glass epoxy resin, and is attached so that the back side faces and is in close contact with the base 41 of the heat dissipation means 4. Therefore, the heat dissipating means 4 is arranged to face the back side of the substrate 7 and is thermally coupled to the substrate 7. Note that, for example, a thermally conductive silicone sheet may be interposed between the base 41 of the heat radiating unit 4 and the back surface side of the substrate 4 to be coupled. Further, the bonding may be performed by interposing an adhesive. In this case, a material having a good thermal conductivity obtained by mixing a metal oxide or the like with a silicone resin adhesive is used as the adhesive. preferable. Moreover, when the material of the substrate 7 is an insulating material, a ceramic material or a synthetic resin material having relatively good heat dissipation characteristics and excellent durability can be applied. Moreover, when using metal, it is preferable to apply a material having good thermal conductivity such as aluminum and excellent heat dissipation.

  Subsequently, as representatively shown in FIG. 4, a reflector 8 made of white polycarbonate, ASA resin, or the like is disposed on the surface side of the substrate 7. The reflector 8 has a function of efficiently irradiating the light emitted from the LED 6 by controlling the light distribution. The reflector 8 has a disk shape, and a plurality of incident apertures 8i, specifically, a total of 21 incident apertures 8i are formed for each LED 6 so as to face each LED 6 by a ridge line portion of the partition wall. First, the reflector 8 is formed with a first partition wall 8a, a second partition wall 8b, and an outer peripheral edge portion 8c concentrically from the central portion toward the outer periphery, and the partition walls 8a and 8b and the outer peripheral edge portion. On the inner peripheral side of 8c, each incident opening 8i is partitioned and arranged by a radial partition 8d. The reflector 8 configured as described above has a reflecting surface 8f formed by each partition corresponding to each incident opening 8i, that is, the first partition 8a, the second partition 8b, the outer peripheral edge 8c, and the radial partition 8d. Is substantially bowl-shaped and widens from the entrance opening 8i to the exit opening 8o, that is, toward the ridgeline portion, and a reflection surface 8f is formed for each entrance opening 8i.

  Next, the power supply unit 3 includes a power supply circuit 31, a power supply terminal block 32, and an arm-shaped attachment member 33. The attachment member 33 includes a fixing portion 33a to the light source unit 2 and an attachment portion 33b connected to the fixing portion 33a via a hinge 33c. A power circuit 31 including a power circuit board is mounted on the lower surface side of the mounting portion 33b. Electrical components such as a control IC, a transformer, and a capacitor are mounted on the power circuit board, and the power circuit board is electrically connected to the board 7 on which the LED 6 is mounted. The lighting is controlled. A power supply terminal block 32 that is connected to a commercial power source and supplies power to the power supply circuit 31 is attached to the rear portion on the lower surface side of the attachment portion 33b. And the fixing | fixed part 33a of the attachment member 33 is attached to the upper surface of the said subradiation fin 42S by fixing means, such as a screw.

  As shown in FIG. 5, such a downlight 1 is inserted into the embedding hole of the ceiling surface C from the power supply unit 3 side and supported in a state of being embedded in the back side of the ceiling surface C. In this case, the flange 51 of the decorative frame 5 has a larger diameter than the embedding hole of the ceiling surface C, and the downlight 1 is hooked from below on the periphery of the embedding hole in a state where the downlight 1 is installed on the ceiling surface C. A support leg 33d is provided on the rear end side of the mounting member 33, and the support leg 33d supports the mounting member 33 by contacting the back surface of the ceiling surface C.

  In the above configuration, when the power supply unit 5 is energized, the lighting circuit operates to supply power to the substrate 7 and the LED 6 emits light. Most of the light emitted from each LED 6 is directly transmitted through the translucent cover 9 and irradiated forward, and a part of the light is reflected on each reflecting surface 8f of the reflector 8 to control the light distribution to be translucent cover. 9 is transmitted forward. On the other hand, the heat generated from the LED 6 is transmitted mainly from the back surface of the substrate 7 to the base 41 of the heat radiating means 4 and is conducted to the plurality of heat radiating fins 42 to be radiated. Here, since the groove 43M between the main radiating fins 42M in the central portion is formed to be relatively long across the peripheral edge portion of the base 41, it functions as an air passage, and the convection of the outside air by natural convection is on one side. It acts between the peripheral edge part and the other peripheral edge part, the side surface of the main radiating fin 42M is mainly cooled, and heat dissipation is efficiently promoted. Further, since the auxiliary heat radiating fins 42S are formed on both sides of the main heat radiating fins 42M, convection of outside air also acts on the grooves 43S, and the side surfaces of the auxiliary heat radiating fins 42S are mainly cooled to radiate heat. . In addition, the convection by the groove 43S of the sub-radiation fin 42S also acts on the outermost main radiating fin 42Mo orthogonal to the direction of the convection, so that the heat radiated by the main radiating fin 42M is increased as a whole. Further, since the back surface of the reflector 8 is in contact with almost the entire front surface of the substrate 7 and the adhesion is maintained, heat is also released by heat conduction from the substrate 7 to the reflector 8.

  Therefore, the heat dissipation performance of the substrate 7 is improved, and the temperature distribution of the substrate 7 is also averaged and the temperature is equalized. That is, particularly in the initial lighting stage of the LED 6, in the temperature distribution of the substrate 7, heat tends to concentrate in the central portion and become high temperature. However, since the central portion of the substrate 7 is configured to have a higher heat dissipation effect than the peripheral portion by the action of the main heat dissipating fins 42M of the heat dissipating means 4, soaking of the entire substrate 7 is promoted. This soaking can stabilize the luminous flux early when the LED 6 is turned on, and can reduce the influence on the life of the LED 6.

  As described above, according to the present embodiment, the light source unit 2 that can improve the heat dissipation performance of the substrate 7 on which the plurality of LEDs 6 are mounted and can promote soaking, and the luminaire 1 using the light source unit 2 are provided. be able to. Further, since the light source unit 2 does not include the power source unit 3, the light source unit 2 can be reduced in size. Furthermore, since the power supply unit 3 is attached to the sub-radiation fin 42S of the heat dissipation means 4, the influence of heat acting on the power supply unit 3 can be reduced.

  Next, light source units according to second to fifth embodiments of the present invention will be described with reference to FIGS. 6 to 11. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

(Second Embodiment) FIG. 6 is a partial sectional view showing a lighting apparatus. As shown in the figure, the main heat radiating fin 42M of the heat radiating means 4 is formed to have a large height. Therefore, the heat dissipation area can be increased, and the heat dissipation effect at the center of the substrate 7 can be enhanced.
Therefore, in the present embodiment, the height dimension of the outermost main radiating fin 42Mo is at least substantially equal to the height dimension of the groove 43S formed by the sub-radiating fin 42S, specifically, the outermost main radiating fin. The height dimension of 42Mo is formed higher than the height dimension of the groove 43S of the sub-radiating fin 42S.

  (Third Embodiment) FIG. 7 is a top view showing a lighting apparatus. As shown in the figure, the main heat radiating fin 42M of the heat radiating means 4 is formed so as to extend between the peripheral portions of the base 41, and the groove 43M is formed, but is arranged slightly closer to the inner peripheral side than the peripheral end. Is. According to this embodiment, the same effect as that of the first embodiment can be obtained.

  (Fourth Embodiment) FIG. 8 is a top view showing a light source unit. As shown in the figure, a space is formed without providing a fin at the center of the block of the sub-radiating fin 42S formed on both sides of the main radiating fin 42M. According to this embodiment, the same effect as that of the first embodiment can be obtained.

  (Fifth Embodiment) FIG. 9 is a top view showing a light source unit. As shown in the figure, the thickness dimension of the main radiating fin 42M of the radiating means 4 is formed to be large. The heat dissipation capacity can be increased, and the heat dissipation effect at the center of the substrate 7 can be enhanced. In addition, you may comprise by adjusting the pitch of each main radiation fin 42M.

  (Sixth Embodiment) FIG. 10 is a top view showing the same light source unit. As shown in the figure, the fins are not provided at the substantially central portion of the main radiating fins 42M, a space is formed, and the main radiating fins 42M are divided into two blocks. That is, the groove 43M formed by the plurality of heat radiation fins 42M is divided. This embodiment can also induce convection and promote heat dissipation.

( Seventh Embodiment ) FIG. 11 is a top view showing the same light source unit. As shown in the figure, the outermost main radiating fin 42Mo and the central side end of the sub radiating fin 42S perpendicular to the main radiating fin 42Mo are continuously and integrally formed. Also according to the present embodiment, promotion of heat dissipation similar to that of the first embodiment is achieved. Note that a part of the sub-radiating fins 42S, for example, only the six fins at the center may be formed continuously with the main radiating fins 42Mo.

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, the groove formed by the plurality of heat radiating fins only needs to have a form for guiding convection. Furthermore, the heat radiating fins increase the surface area of the heat radiating means, and are not limited to shapes such as fins, flat plates, and chevron shapes, and may be formed so as to protrude, and the shape is not limited.

It is a fragmentary sectional view showing the lighting fixture concerning a 1st embodiment of the present invention. It is the same top view. It is the bottom view. It is a perspective view which shows a reflector. It is explanatory drawing which shows the state which attached the lighting fixture to the ceiling surface. It is a fragmentary sectional view which shows the lighting fixture which concerns on the 2nd Embodiment of this invention. It is a top view which shows the lighting fixture which concerns on the 3rd Embodiment of this invention. It is a top view which shows the light source unit which concerns on the 4th Embodiment of this invention. It is a top view which shows the light source unit which concerns on the 5th Embodiment of this invention. It is a top view which shows the light source unit which concerns on the 6th Embodiment of this invention. It is a top view which shows the light source unit which concerns on the 7th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Lighting fixture (downlight), 2 ... Light source unit, 3 ... Power supply unit,
4 ... heat dissipation means, 6 ... light emitting element (LED), 7 ... substrate,
42M ... main radiating fin, 42S ... sub radiating fin, 43M, 43S ... groove

Claims (2)

A substrate on which a plurality of light emitting elements are mounted in a central portion and a peripheral portion thereof;
A main radiating fin that faces the back side of the substrate and is provided so as to be thermally coupled to the substrate, and that forms a plurality of grooves at the center of the back side and between the peripheral portions, and the main radiating fin A sub-radiation fin that is in a direction perpendicular to the main radiating fin and that forms a plurality of grooves so as to oppose the outermost main radiating fin. The height dimension is a heat radiating means formed at least approximately equal to the height dimension of the groove formed by the sub-radiation fin ;
A light source unit comprising: A light source unit according to claim 1;
A power supply unit attached to the sub-radiation fin of the light source unit;
The lighting fixture characterized by comprising.

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