JP2009301810A - Illuminating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating device with at least two sheets of power source circuit boards arranged in a body in a direction crossing a board having light-emitting elements arranged, with downsizing of the device aimed at, and for promoting soaking and heat radiation of the power source circuit boards. <P>SOLUTION: The illuminating device 1 includes a body 2 with thermal conductivity, a board 4 thermally coupled with the body 2 and having light-emitting elements 10 arranged, and at least two sheets of power source circuit boards 20a, 20b housed inside the body 2 in a direction crossing the board 4, with their rear faces 20e opposed to each other and with a component face 20d made opposed to an inner wall 2b of the body 2, and electrically connected with the board 4 for controlling lighting of the light-emitting elements 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lighting device using a light emitting element such as an LED.

Conventionally, in the case where the LED mounting board, the heat radiation means, and the DC power supply circuit are housed in the cover, in order to increase the light output of the LED lighting device, the number of LED elements is increased, or the current passed through the LED elements is increased. If this is done, the amount of heat generated by the LED element will increase, and this heat may affect the operation of the DC power supply circuit, and the DC power supply circuit needs to increase the current supplied to the LED element. The amount of heat generated by itself increases, and this heat increases the temperature of the LED element, and the deterioration of the characteristics of the electronic component may lead to a decrease in the lifetime. For this reason, a heat transfer means that can transfer the heat of the heat dissipation means to the cover is provided to efficiently dissipate heat (see Patent Document 1).
JP 2004-55800 A

  However, as the light output of this type of lighting device increases, the power supply circuit board tends to increase in size. However, Patent Document 1 discloses a small size of the entire apparatus when the power supply circuit board is increased in size. There is no disclosure of heat dissipation measures.

  The present invention has been made based on the above circumstances, and at least two power circuit boards are arranged in the main body in a direction orthogonal to the board on which the light emitting elements are arranged, so that the apparatus can be miniaturized. An object of the present invention is to provide an illuminating device capable of equalizing heat and promoting heat dissipation.

  The lighting device according to claim 1 is a thermally conductive main body; a substrate thermally coupled to the main body and provided with a light emitting element; and lighting control of the light emitting element electrically connected to the substrate. And at least two power supply circuit boards disposed in the main body in a direction orthogonal to the substrate, the power circuit boards housed with the back surfaces facing each other and the component surfaces facing the inner wall of the main body. It is characterized by doing.

  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. Moreover, there is no restriction | limiting in particular in the mounting number of a light emitting element. The main body includes what is referred to as a so-called main body, case or cover. In short, it means means on the side of the instrument to which the substrate is attached. The lighting device is a concept including a display device and a lighting fixture that illuminates a so-called space.

  A lighting device according to a second aspect is the lighting device according to the first aspect, wherein among the heat generating components mounted on the component mounting surfaces of the at least two power supply circuit boards, the heat generating components having the largest heat generation amount It is characterized by being arranged so as not to be opposed.

  The lighting device according to claim 3 is the lighting device according to claim 1 or 2, wherein the at least two power supply circuit boards have the same configuration.

  The lighting device according to claim 4 is the lighting device according to any one of claims 1 to 3, wherein one end of the at least two power supply circuit boards is attached to a board mounting plate. An air flow gap is formed between one end of the substrate and the board mounting plate.

  According to the first aspect of the present invention, it is possible to provide a lighting device that can reduce the size of the lighting device and can equalize the temperature of the power circuit board and promote heat dissipation.

  According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, it is possible to provide a lighting device capable of reducing the thermal influence between the power supply circuit boards.

  According to the invention described in claim 3, in addition to the effects of the invention described in each of the above claims, the power supply circuit board can be shared, the complexity of component management can be reduced, and an inexpensive lighting device is provided. I'm going.

  According to invention of Claim 4, in addition to the effect of the invention of each said claim, the illuminating device which can accelerate | stimulate a convection and heat radiation can be provided.

  Hereinafter, a lighting device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. 1 is a perspective view showing a lighting device, FIG. 2 is an exploded perspective view thereof, FIG. 3 is a cross-sectional view showing a schematic configuration of a main part, and FIG. 4 is a plan view thereof.

  1 and 2, a ceiling-embedded downlight 1 is shown as a lighting device. The downlight 1 includes a thermally conductive cylindrical main body 2, a decorative frame 3 attached to the cylindrical main body 2, and a substrate 4 that is also attached to the cylindrical main body 2 and on which LEDs as light emitting elements are mounted. A power supply unit 5 including a power supply circuit board 20 accommodated in the cylindrical main body 2, and a reflector 6 and a translucent cover 7 disposed in front of the reflector 6 are provided. The translucent cover 7 may be white, translucent, or diffusive. A terminal block 8 is disposed on the outer surface of the cylindrical main body 2, and a pair of attachment leaf springs 9 are mounted on the decorative frame 3.

  The cylindrical main body 2 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 cylindrical main body 2 houses a power supply unit 5, and components such as a control IC, a transformer, and a capacitor are mounted on the power supply circuit board 20. The power circuit board 20 is electrically connected to the board 4 on which the LEDs are mounted, and controls the lighting of the light emitting elements by the power circuit. The power supply unit 5 is connected to a terminal block 8, and the terminal block 8 is connected to a commercial power source. A plurality of radiating fins 2 c extending in the vertical direction are formed on the outer surface of the cylindrical main body 2.

  The decorative frame 3 is formed of an ABS resin in a substantially umbrella shape, an annular flange 3a is formed at the end of the divergent opening, and the other end is attached to the cylindrical main body 2. In addition, a pair of attachment leaf springs 9 are mounted on the outer peripheral surface.

  A plurality of LEDs 10... Serving as light sources are mounted on the surface side of the substrate 4 by a surface mounting method. The substrate 4 is made of a substantially circular flat plate made of an insulating material or metal, and is attached so as to be in close contact with the bottom wall 2 a of the cylindrical main body 2. Therefore, it is thermally coupled to the cylindrical main body 2. Note that an adhesive may be interposed between the bottom wall 2a of the cylindrical main body 2 and the back surface side of the substrate 4 for coupling. In this case, it is preferable to use a material having a good thermal conductivity obtained by mixing a metal oxide or the like with a silicone resin adhesive. The adhesive here is only required to be in close contact with the bottom wall 2a and the substrate 4, and may be a simple sheet-like member or a cured resin. Moreover, when the material of the substrate 4 is an insulating material, a ceramic material or a synthetic resin material having relatively good heat dissipation characteristics and excellent durability can be applied. When a synthetic resin material is used, it can be formed of, for example, a glass epoxy resin. Moreover, when using metal, it is preferable to apply a material having good thermal conductivity such as aluminum and excellent heat dissipation.

  Subsequently, a reflector 6 made of white polycarbonate, ASA resin or the like is disposed on the surface side of the substrate 4. The reflector 6 functions to efficiently irradiate the light emitted from the LED by controlling the light distribution.

  Next, the power supply unit 5 will be described in detail with reference to FIGS. The power supply unit 5 includes two power supply circuit boards 20a and 20b and a board mounting plate 20c for mounting the power supply circuit boards 20a and 20b. Here, the power circuit board 20 needs to be increased in size as the optical output increases, but in order to reduce the size of the apparatus, the circuit is divided into two parts, that is, the power circuit board 20 is divided into two parts. In the storage area in the cylindrical main body 2.

  Each power circuit board 20a, 20b is made of an insulating material such as glass epoxy resin, and is configured as a substantially rectangular flat plate. Electrical components 21 such as a control IC, a transformer, a capacitor, and a resistance element are mounted on the component surfaces of the power supply circuit boards 20a and 20b, that is, the component mounting surface 20d. Furthermore, the power supply circuit boards 20a and 20b are attached to the board mounting plate 20c so that the solder surface opposite to the component mounting surface 20d, that is, the back surface 20e faces each other. The electrical component 21 is mainly mounted on the component mounting surface 20d of the power circuit boards 20a and 20b, but a part is also mounted on the substrate back surface 20e (not shown). The board mounting plate 20c is formed so that four cut-and-raised pieces 21a hang down. One end of the power circuit boards 20a and 20b, that is, the upper end is screwed and fixed to the cut-and-raised piece 21a. Yes. In this state, an air flow gap t in the range of 2 to 10 mm, preferably 3 mm or more is formed between the upper ends of the power circuit boards 20a and 20b and the lower surface of the board mounting plate 21. .

  As shown in FIG. 2, the power supply circuit boards 20a and 20b attached to the board attaching plate 20c are accommodated in the cylindrical main body 2 from above. Thereafter, the top plate 22 is covered from above and screwed, and the power circuit boards 20a and 20b are housed in the cylindrical body 2 in a sealed state. Further, a terminal block attachment lid 23 is attached from the top plate 22. On the other hand, as shown in FIGS. 3 and 4, the cylindrical body 2 in which the power circuit boards 20a and 20b are housed has a substantially rectangular parallelepiped space formed by the inner wall 2b. The substrates 20a and 20b are arranged in the vertical direction. Therefore, the back surfaces 20e of the power supply circuit boards 20a and 20b face each other, and the component mounting surface 20d faces the inner wall 2b of the cylindrical main body 2. Reference numeral 24 denotes a lead-out hole for leading out a lead wire for connecting the substrate 4 and the power circuit boards 20a and 20b (see FIG. 4).

  As shown in FIG. 3, a plurality of light projecting openings 6 a... Are formed in the reflector 6 so as to face the LEDs 10 mounted on the substrate 4. The reflective surfaces 6f ... formed by the respective partitions corresponding to the projection openings 6a ... are substantially bowl-shaped and are expanded from the projection openings 6a ... toward the ridge line portion, A reflecting surface 6f is formed for each of the projection openings 6a.

  In the configuration as described above, when the power supply unit 5 is energized, the power supply circuits of the power supply circuit boards 20a and 20b operate to supply power to the board 4, and the LEDs 10 ... emit light. Most of the light emitted from each LED 10... Is directly transmitted through the translucent cover 7 and irradiated forward, and a part of the light is reflected by each reflecting surface 6 f. The light is transmitted through the translucent cover 7 under control. Accordingly, the heat generated from the LEDs 10... Is mainly transmitted from the back surface of the substrate 4 to the bottom wall 2a of the cylindrical main body 2 and further conducted to the entire cylindrical main body 2 with heat dissipation in the conduction process. While dissipating heat.

  On the other hand, the heat generated from the power supply circuit boards 20a and 20b is arranged in the vertical direction so that the power supply circuit boards 20a and 20b are orthogonal to the board 4, and therefore between the back surfaces 20e and the component mounting surface 20d and the cylindrical shape. Heat is radiated from the tubular body 2 with convection between the inner walls 2b of the body 2 and further with convection through the air circulation gap t. Moreover, since the component mounting surfaces 20d of the power supply circuit boards 20a and 20b are opposed to the inner wall 2b, the radiant heat is transmitted to the inner wall 2b, which also promotes heat dissipation. Therefore, each power supply circuit board 20a, 20b can equalize heat and can effectively dissipate heat. Further, since the power supply circuit boards 20a and 20b are arranged so as to be orthogonal to the board 4, the heat of the board 4 is easily radiated by convection between the power supply circuit boards 20a and 20b, and the power supply circuit boards 20a and 20b Since the substrate 4 is not disposed oppositely, the heat of the substrate 4 is not intensively radiated to either one of the power supply circuit substrates.

  If the power supply circuit boards 20a and 20b are arranged so as to overlap in the horizontal direction, convection is not promoted, and the power supply circuit boards 20a and 20b are affected by thermal influences from the board 4 and the power supply circuit boards 20a and 20b. Under the influence of mutual heat, the temperature rises locally, or the temperature of one power supply circuit board rises, so that it becomes difficult to equalize heat and thus to dissipate heat.

  As described above, according to the present embodiment, (1) the substrate 4 on which the LEDs 10... Are mounted and the power circuit board 20 can be provided in the main body 2. Therefore, it is possible to reduce the size of the lighting device. (2) Since the power circuit boards 20a and 20b are arranged so that the back surfaces 20e face each other, the back surface 20e has few protrusions and is easy to arrange. (3) Since the power supply circuit boards 20a and 20b are arranged in the vertical direction so as to be orthogonal to the board 4, the back surface 20e faces each other, and the component mounting surface 20d faces the inner wall 2b. The action can be performed effectively and soaking can be achieved.

  In this embodiment, two power supply circuit boards are provided. For example, four power supply circuit boards are provided, and two power supply circuit boards are arranged in the vertical direction with the back surfaces facing each other. May be.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is an explanatory diagram showing a schematic plan configuration of the power supply circuit board. The illustrated power supply circuit boards 20a-2 and 20b-2 correspond to the power supply circuit boards 20a and 20b of the first embodiment, and are opposed to each other so that their back surfaces 20e face each other as shown by arrows. It is attached to the plate 20c.

  In the present embodiment, when the power supply circuit boards 20a-2 and 20b-2 are attached, they are arranged so that heating components such as so-called control ICs, resistance elements, and diodes do not face each other, and mutual heat via the back surface 20e. The effect is reduced to prevent local temperature rise. First, the heat generating component H is mounted on the left central portion and the right lower portion of the power circuit board 20a-2 (see the left figure). Therefore, this area is the mounting area HA for the heat generating component H, and the other area is the mounting area A for the non-heat generating component.

  In the power supply circuit board 20b-2 (see the right figure) combined with the power supply circuit board 20a-2, when the power supply circuit board 20a-2 is opposed, the mounting area of the heat generating component H of the power supply circuit board 20a-2 The heat generating component H is mounted so as not to be opposed to the HA. That is, the lower left portion and the right central portion of the power supply circuit board 20a-2 that face the mounting area HA of the heat generating component H are the mounting prohibited areas NHA of the heat generating component H. Therefore, the heat generating component H is mounted in another region, and the non-heat generating component is mounted in a space as appropriate in design. Here, this does not mean that the heat generating component H should not be opposed to the mounting prohibited area NHA at all. Depending on the arrangement space of the electrical components 21 of the power supply circuit boards 20a-2 and 20b-2 and the thermal conditions, some relative tolerance is allowed (the heating component H in the lower right of the power supply circuit board 20b-2 is shown). .

  Furthermore, among the heat generating components, there are components with large and small heat generation amounts. Among the heat generating components mounted on the power supply circuit boards 20a-2 and 20b-2, at least the components with the largest heat generation amount are relative to each other. It is preferable to arrange so that it does not occur. For example, in the power supply circuit board 20a-2, the component that generates the largest amount of heat is a control IC, and in the power supply circuit board 20b-2, it is preferable that these components be mounted so as not to be opposed to each other. is there.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, there is an effect that the thermal influence between the power supply circuit boards 20a-2 and 20b-2 can be reduced.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6 is an explanatory diagram showing a schematic plan configuration of the power supply circuit board. Like the second embodiment, the power supply circuit boards 20a-3 and 20b-3 shown in the figure are the power supplies of the first embodiment. It corresponds to the circuit boards 20a and 20b, and is attached to the board mounting plate 20c so that their back surfaces 20e face each other.

  In the present embodiment, basically, the same power supply circuit boards 20a-3 and 20b-3 are used. In other words, here we use the same two power supply circuit boards intended for a lighting device of a certain low watt equivalent, and apply them to a high watt equivalent with the increase of light emitting elements. It is intended. In addition, the thermal influence between the power supply circuit boards is reduced, and a local temperature rise or the like is prevented.

  The power circuit board 20a-3 will be described as a representative. On the power circuit board 20a-3, a control IC, a transformer, a diode, an aluminum electrolytic capacitor, a resistance element, a capacitor, a power connector, and the like are mounted. Here, the heat generating component H is a control IC, a diode, an aluminum electrolytic capacitor, and a resistance element. As shown in the figure, the heat generating component H is substantially divided into left and right, and when the power supply circuit boards 20a-3 and 20b-3 are mounted on the board mounting plate 20c, there is almost no portion where the heat generating component H faces. Here, the component having the largest amount of heat generation is a control IC, and of course, the control ICs are not opposed to each other.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the power supply circuit boards 20a-3 and 20b-3 can be shared, and the power supply circuit boards 20a-3 and 20b can be shared. -3 Has the effect of reducing the mutual thermal effects.

  Next, an illuminating device according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a sectional view showing a schematic configuration of the main part, and FIG. 8 is a plan view thereof. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent, and the overlapping description is abbreviate | omitted. In the present embodiment, a shielding member 25 is provided between the power circuit boards 20a and 20b. The shielding member 25 is formed so as to partition the space formed by the inner wall 2b in the cylindrical main body 2 into the power circuit board 20a side and the power circuit board 20b side, and is integrated from the bottom wall 2a of the cylindrical main body 2. It is configured to stand up.

  According to such a configuration, the radiant heat generated from the solder surfaces of the power circuit boards 20a and 20b, that is, the back surface 20e, is radiated to the shielding member 25 without interfering with the back surface 20e. The heat is dissipated through conduction. Furthermore, the heat generated from the back surface 20e rises along the shielding member 25, passes through the air circulation gap t, and heat dissipation is promoted by convection. Therefore, the temperature rise of the electrical component 21 mounted on the power supply circuit boards 20a and 20b can be suppressed. The shielding member 25 may be configured separately from the cylindrical main body 2 and attached to the inner wall 2b of the main body 2.

  As described above, according to the present embodiment, in addition to the effects of the first embodiment, the shielding member 25 can suppress the temperature rise of the electrical components 21 mounted on the power circuit boards 20a and 20b. Play.

  Next, a modification of the fourth embodiment will be described with reference to FIG. FIG. 9 is a cross-sectional view showing a schematic configuration of a main part. In this example, the power supply circuit boards 20a and 20b in the fourth embodiment are mounted on the board mounting plate 20c so that the back surfaces 20e do not face each other. That is, the back surface 20 e of the power circuit board 20 b faces the inner wall 2 b of the cylindrical body 2, and the component mounting surface 20 d faces the shielding member 25. Therefore, the heat of the component mounting surface 20d of the power circuit board 20a is radiated to the inner wall 2b, and the heat of the back surface 20e is radiated to the shielding member 25 and is radiated with convection. On the other hand, the heat of the component mounting surface 20d of the power circuit board 20b is radiated to the shielding member 25, and the heat of the back surface 20e is radiated to the inner wall 2b and radiated with convection. Of course, the back surface 20e of the power circuit board 20a may be opposed to the inner wall 2b of the cylindrical main body 2 and the component mounting surface 20d may be opposed to the shielding member 25.

  As described above, according to this example, the same effects as those of the fourth embodiment can be obtained.

It is a perspective view which shows the illuminating device which concerns on the 1st Embodiment of this invention. It is the same exploded perspective view. It is sectional drawing of the principal part. It is the same top view. It is explanatory drawing which shows the planar structure of the power supply circuit board which concerns on the 2nd Embodiment of this invention. It is explanatory drawing which shows the planar structure of the power supply circuit board which concerns on the 3rd Embodiment of this invention. It is sectional drawing of the principal part which shows the illuminating device which concerns on the 4th Embodiment of this invention. It is the same top view. It is sectional drawing which shows schematic structure of the modification of the 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Illuminating device (downlight), 2 ... main body, 2b ... inner wall of main body,
4 ... Substrate, 10 ... Light emitting element (LED), 20a, 20b ... Power supply circuit board,
20d: component mounting surface of power circuit board, 20e: back surface of power circuit board,

Claims (4)

A thermally conductive body;
A substrate thermally coupled to the body and provided with a light emitting element;
The light emitting element is electrically connected to the substrate to control lighting, and at least two pieces are disposed in the main body in a direction orthogonal to the substrate, the back surfaces thereof are opposed to each other, and the component surface is the inner wall of the main body. A power circuit board housed opposite to the board;
An illumination device comprising:   The lighting device according to claim 1, wherein among the heat generating components mounted on the at least two power supply circuit boards, the heat generating components having the largest heat generation amount are arranged so as not to face each other.   The lighting device according to claim 1, wherein the at least two power supply circuit boards have the same configuration.   2. The at least two power circuit boards have one end attached to a board mounting plate, and an air flow gap is formed between the one end of the board and the board mounting plate. The lighting device according to claim 3.

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