JP2016004602A - Lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting device which achieves high efficiency.SOLUTION: A lighting device includes: a substrate on which multiple LEDs are placed; and a heat sink having a case to which the substrate is fixed and multiple heat radiation fins formed on an outer surface of the case. Each heat radiation fin has a protruding part which is a portion protruding relative to a lower end of the case.

Description

  The present invention relates to a lighting device.

  Currently, there is a demand for a lighting device that has a large amount of light and is highly efficient. In order to achieve high efficiency, it is important to improve heat dissipation. Further, improving the heat dissipation contributes to a longer life.

  In Patent Document 1, a disk-shaped substrate on which an LED is mounted and a reflector disposed below the substrate are accommodated in a sealed case, and the reflector is attached to the opening on the lower surface of the sealed case so as to be supported from below. A lighting device is described in which a plurality of heat dissipating fins that are closed with a disk-shaped cover and are not projected from the lower end of the case toward the lower surface are arranged on the outer surface of the case in a longitudinal sectional view.

Japanese Patent No. 5417085

  As described above, in order to achieve high efficiency, it is important to improve heat dissipation. In the illuminating device described in Patent Document 1, there is a risk that the improvement in heat dissipation is limited.

  In view of the above circumstances, an object of the present invention is to provide a highly efficient lighting device with improved heat dissipation.

  In order to solve the above-described problem, an illumination device of the present invention includes a substrate on which a plurality of LEDs are mounted, a heat sink having a case to which the substrate is fixed, and a plurality of heat radiation fins formed on an outer surface of the case. The radiating fin has a protruding portion that is a portion protruding from the lower edge of the case.

  ADVANTAGE OF THE INVENTION According to this invention, the highly efficient illuminating device which improved heat dissipation can be provided.

(a) is a perspective view which shows the lighting fixture which attached the illuminating device which concerns on embodiment of this invention, (b) is a perspective view which shows the state which attaches a luminaire to the hanging tool in the reflective shade of a lighting fixture. The A direction arrow directional view of FIG.1 (b). The longitudinal cross-sectional view of an illuminating device. The perspective view which looked at the illuminating device of FIG. 2 from diagonally upward. The perspective view which looked at the illuminating device of FIG. 2 from diagonally downward. The bottom view which looked at the illuminating device of FIG. 2 from the downward direction. The perspective view containing the partial cross section which looked at the illuminating device from diagonally downward. (a) is a diagram showing a state in which the lighting device is mounted sideways, (b) is a schematic diagram of the strength fin portion when the lighting device is mounted sideways, and (c) is a diagram showing the lighting device mounted sideways. The schematic diagram at the time of setting the pitch of the strength fin at the time of 45 degrees. The schematic diagram showing a light distribution angle. The exploded view of an illuminating device. The figure which shows the temperature rise of the LED module with respect to the pitch of the fin in the heat sink for thermal radiation, and its weight.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

  FIG. 1 (a) shows a lighting fixture to which a lighting device according to an embodiment of the present invention is attached, and FIG. 1 (b) shows a state in which the lighting device is attached to a hanger in a reflective shade of the lighting fixture.

  Further, FIG. 2 shows a side view of the lighting device in the direction of arrow A in FIG. 1B, and FIG. 3 shows a longitudinal sectional view of the lighting device.

  The lighting device S of the embodiment (see FIG. 1B) is a lighting device that uses an LED (Light Emitting Diode), and is characterized by improved heat dissipation and improved efficiency.

  As shown to Fig.1 (a), the illuminating device S is attached and used for the hanging tool k2 in the reflective shade k1.

  Specifically, the illuminating device S is electrically connected to a power supply device k3 that is separate from the illuminating device S and is turned on by screwing and attaching the base 5a to the hanger k2 in the reflective shade k1.

  As described above, the lighting fixture K includes the hanging tool k2, the reflective shade k1, the power supply device k3, and the lighting device S. The lighting fixture K is often installed at a high place such as a factory, and weight reduction is important. Moreover, as for the lighting fixture K, efficiency and brightness are naturally important.

  As shown to Fig.1 (a), the illuminating device S and the power supply device k3 in this embodiment are installed separately. The illumination device S is attached to the hanging tool k2 as described above, and the power supply device k3 is placed on the ceiling or the like. In other words, the illumination device S does not have the power supply device k3 between the base 5b and the LED substrate assembly 2. In other words, the illuminating device S is input with the DC power converted by the separately installed power supply device k3. By providing the power supply device k3 separately from the lighting device S, the lighting device S can be reduced in weight.

  FIG. 4 is a perspective view of the illuminating device of FIG. 2 as viewed obliquely from above (viewed in the direction of arrow B in FIG. 2), and FIG. 5 is a perspective view of the illuminating device of FIG. Direction arrow view).

  6 shows a bottom view (viewed in the direction of arrow D in FIG. 2) of the lighting device of FIG. 2 from below, and FIG. 7 shows a perspective view including a partial cross section of the lighting device seen from diagonally below. .

  The illumination device S includes a heat sink 1 for heat dissipation, an LED board assembly 2 (see FIG. 5), a main body support case 3 and a base 5.

  As shown in FIGS. 3 and 7, the translucent cover 4 is fixed to the lower part of the truncated cone-shaped case 1 a of the heat sink 1 for heat dissipation by sandwiching the sealing packing 7 with six screws n <b> 1. Has been. The sealing packing 7 is a component made of rubber or the like and having a large-diameter ring shape (see FIG. 10).

  The main body support case 3 and the heat sink 1 for heat dissipation are fixed by screws n2 with a sealing packing 8 (see FIG. 7) interposed therebetween.

<Heat dissipation heat sink 1>
The heat sink 1 for heat dissipation is formed, for example, by aluminum die casting using aluminum as a material. As the material for the heat sink 1 for heat dissipation, a material having heat dissipation and light weight is used. The heat sink 1 for heat dissipation is anodized or painted on the surface.

  As shown in FIGS. 5 and 6, the heat sink 1 for heat dissipation is a member that dissipates heat generated from the LED module 2 a while the LED board assembly 2 is installed.

  The heat sink 1 for heat dissipation has a case 1a on which the LED board assembly 2 (see FIG. 5) is placed, a plurality of fins 1b, and three strength fins 1c (see FIG. 4).

  The fins 1b are formed on the side and upper outer surfaces of the case 1a, and the heat generated in the LED board assembly 2 is transmitted to dissipate heat.

  The strength fins 1c are formed on the outer surface of the side portion and the upper portion of the case 1a. The strength fins 1c are strength members of the heat sink for heat dissipation 1 and transmit heat generated by the LED board assembly 2 to dissipate heat.

<Case 1a>
As shown in FIGS. 2 and 4, the case 1a has a truncated cone shape with a low height. That is, the case 1a has a disk-shaped top plate 1a1 and a conical plate 1a2 that spreads downward in a conical shape.

  An LED substrate assembly 2 (see FIG. 3) described later is installed on the inner surface of the disk-shaped top plate 1a1. The conical plate 1a2 that forms an inclined conical plate has an inclination of about 20 degrees with respect to the vertical direction.

  On the inner surface of the conical plate 1a2, a reflector 1ar that reflects light emitted from the LED module 2a constituting the LED board assembly 2 and collects it at the center is formed. The reflector 1ar is formed by applying a reflective material having a high reflectance to the inner surface of the conical plate 1a2. Note that the reflector 1ar is not limited to the application of the reflecting material, but may have a function of reflecting the light emitted from the LED module 2a. A highly reflective film may be used.

<Fin 1b>
The plurality of fins 1b shown in FIGS. 4 and 5 are erected from the center (center axis O) of the lighting device S radially outward from the outer surface of the case 1a toward the side, lower (see FIG. 2), and upper. ing. The plurality of fins 1b are formed with a pitch θ1 of 10 degrees.

  Since the fin 1b is erected from the outer surface of the case 1a to the side part from the side edge 1s toward the outside, the heat transmitted to the heat sink 1 for heat dissipation is transferred to the side of the case 1a via the fin 1b. Heat can be efficiently radiated to the external space.

  Further, since the fin 1b is erected outward from the outer surface of the case 1a, heat transmitted to the heat sink 1 for heat dissipation is efficiently transferred to the external space above the case 1a via the fin 1b. Heat can be released.

  Further, the fin 1b is erected from the outer surface of the case 1a downward from the lower edge 1u (see FIGS. 2 and 3), so that the heat transmitted to the heat sink 1 can be transferred via the fin 1b. Heat can be efficiently radiated to the lower external space.

  As shown in FIG. 2, the fin 1b gradually increases in thickness as it goes downward from the top, and gradually decreases as it goes downward from a certain height. In other words, the fin 1b gradually increases in thickness from the center lower part to the upper part, and gradually decreases in thickness from the center lower part to the lower part.

  As the fin 1b gradually decreases in thickness from the center lower part to the upper part, air including heat transmitted from the fin 1b can smoothly escape upward from between the fins 1b. Further, since the fins 1b gradually become thinner from the center lower part to the lower part, the cold air in the external space can smoothly enter between the fins 1b from below the heat sink 1 for heat dissipation.

  Due to such a shape of the fin 1b, when the heat sink 1 for heat dissipation is molded, it is possible to perform die cutting from above and below satisfactorily.

  The center side of the fin 1b is an inclined surface 1b1 (see FIG. 2) that is inclined outward. The inclination angle of the inclined surface 1b1 with respect to the vertical direction is larger than the inclination angle of the reflector 1ar (see FIG. 7) described later so as not to prevent the light from traveling from the LED module 2a.

<Strength fin 1c>
The three strength fins 1c shown in FIGS. 2 to 4 are strength members of the heat sink 1 for heat dissipation and also serve for heat dissipation as fins.

  The strength fins 1c are formed on the upper surface and the outer surface of the case 1a radially outward from the center (center axis O) of the lighting device S from the center to the outside.

  The strength fin 1c has a larger shape than the fin 1b. Specifically, the strength fin 1c has a shape larger than that of the fin 1b on the upper surface of the case 1a (see FIG. 4).

  Since the strength fins 1c are erected outward from the outer surface of the case 1a toward the side, the heat of the heat sink 1 for heat dissipation is efficiently transferred to the outer space on the side of the case 1a via the strength fins 1c. Can dissipate heat.

  Further, the strength fins 1c are erected outward from the outer surface of the case 1a so that the heat of the heat sink 1 can be efficiently transferred to the external space above the case 1a via the strength fins 1c. Can dissipate heat.

  In addition, since the strength fins 1c are formed radially from the center (center axis O) of the heat sink 1 for heat dissipation at an interval (pitch) of about 120 degrees, the LED module 2a is installed when the lighting device S is installed obliquely. The air warmed by this heat has an effect that it easily escapes above the lighting device S and has excellent heat dissipation.

  FIG. 8A shows a state in which the lighting device is mounted sideways, FIG. 8B shows a schematic diagram of the strength fin portion when the lighting device is mounted sideways, and FIG. The schematic diagram at the time of setting the pitch of the intensity | strength fin to 45 degree | times at the time of attaching an illuminating device in the horizontal direction to c) is shown.

  As shown in FIG. 8 (a), when the lighting device S is mounted in a lateral direction or tilted, as shown by the arrow in FIG. 8 (b), air heated by the heat generated by the LED module 2a (hot air) ) Does not stay between the strength fins 1c and can be released to the upper external space.

  Thus, when the three strength fins 1c are formed at a pitch of approximately 120 degrees, there is an effect of diverting warm air, and an effect of diverting and escaping the flow of warm air.

  Incidentally, as shown in FIG. 8 (c), in the case of the strength fins 11c formed at a pitch of 45 degrees, when the lighting device S is mounted sideways or obliquely, hot air stays between the strength fins 11c. .

  As described above, in the heat sink 1 for heat dissipation, the heat dissipation efficiency of the heat sink 1 for heat dissipation can be effectively improved by the three large strength fins 1c having a length to the center and the small fins 1b therebetween.

<LED board assembly 2>
As shown in FIGS. 5 and 7, the LED board assembly 2 is fixed to the inner surface of the top plate 1a1 of the case 1a by screws n3.

  The LED board assembly 2 includes a large number of LED modules 2a and an LED base board 2b on which the LED modules 2a are mounted.

<LED module 2a>
The LED module 2a is a light source of the lighting device S of the lighting fixture K, and is mounted on the LED base substrate 2b in a band shape as shown in FIG.

  A part of the LED module 2a is radially arranged with an interval (pitch) of about 10 degrees from the central axis O of the lighting device S in the along-straight direction. It arrange | positions so that it may overlap with 1b.

  Thereby, the heat generated in the LED module 2a arranged so as to overlap the fin 1b is favorably transmitted to the fin 1b having a short distance, and is efficiently radiated to the external space through the fin 1b.

  Further, more than half of the LED modules 2a other than the LED module 2a arranged so as to overlap the fins 1b are on the outer peripheral side of the line C1 (see FIG. 6) at the substantially middle portion of the ring shape, that is, outside the line C1. Is arranged. That is, it is arranged outside the line C1 which is an intermediate line between the inner edge 2a1 and the outer edge 2a2 of the band of the LED modules 2a forming an annular shape.

  Thereby, the light of the LED module 2a arranged outside the line C1 is reflected by the reflector 1ar (see FIGS. 5 and 7) on the inner surface of the case 1a of the heat sink 1 for heat dissipation and collected on the center side (center axis O side). It is done.

  Therefore, the light distribution angle can be set to 80 degrees to 100 degrees, and the illuminance can be increased.

  FIG. 9 is a schematic diagram showing the light distribution angle.

  As shown in FIG. 9, the light distribution angle is a point where the intensity of the light intensity peak value of the illumination device S is a center line, and a portion having a half intensity of the light intensity peak value is connected. This is the angle θ3 between the lines.

  Here, as shown in FIG. 3, the vertical dimension L1 from the mounting surface 2b1 of the LED module 2a of the LED base substrate 2b to the lower edge of the reflector 1ar, and the center of the band of the annular band-shaped LED modules 2a The distance L2 between the line C1 and the outer edge of the annular LED module 2a (the outermost portion of the annular LED module 2a) preferably has a relationship of L2 ≦ L1.

  By having this relationship, the light of the LED module 2a arranged on the outer peripheral side from the line C1 at the middle portion of the belt-like annular shape is reflected by the reflector 1ar (see FIGS. 5 and 7), and is collected well. Can be light.

  Thereby, the improvement of the light distribution performance of the light irradiation to the downward direction of the illuminating device S can be aimed at.

<LED base substrate 2b>
The LED base substrate 2b shown in FIGS. 5 to 7 is formed with a wiring pattern for supplying current (voltage) to the mounted LED module 2a. The LED base substrate 2b has a substantially disk shape.

  The LED base substrate 2b has a positioning configuration for arranging a part of the LED module 2a so as to overlap the fins 1b in the vertical direction.

  Specifically, as shown in FIG. 6, four positioning projections 2b1 project outwardly from the outer periphery of the LED base substrate 2b. On the other hand, four positioning concave portions 1o into which four positioning convex portions 2b1 are fitted are formed on the inner surface of the case 1a of the heat sink 1 for heat radiation.

  Further, a cutout portion 2b2 for determining a position in the rotation direction is formed in a cutout shape on the outer peripheral portion of the LED base substrate 2b inward.

  The four positioning protrusions 2b1 of the LED base substrate 2b are fitted into the four positioning recesses 1o of the case 1a, and screws 5 are fastened to the notches 2b2. Thereby, the base substrate 2b for LED can be positioned with respect to the case 1a, and a part of LED module 2a can be arrange | positioned and overlapped with the fin 1b in the perpendicular direction.

  The LED base substrate 2b has an insertion hole through which the fixing screw n3 is inserted.

<Main body support case 3>
The main body support case 3 shown in FIGS. 2 and 3 is a cylindrical resin member. The material of the main body support case 3 is preferably a resin having good heat resistance, high strength, and glossy surface. For example, polycarbonate is used as the material of the main body support case 3. The main body support case 3 also serves as an insulating material between the base 5a and the LED module 2a.

  As shown in FIG. 3, the main body support case 3 has a conical cone portion 3a formed from the lower edge portion to the central upper portion, and a cylindrical cylindrical portion 3b is formed above the conical portion 3a. A base attaching portion 3c into which a male screw is threaded is formed on the upper portion of the cylindrical portion 3b.

  By forming the cylindrical cylindrical portion 3b in the main body support case 3, when the main body support case 3 and the lighting device S are chucked by an automatic machine, the cylindrical cylindrical portion 3b can be reliably gripped. Further, the cylindrical portion 3b is easily grasped when the worker holds the main body support case 3 or the lighting device S.

  A case mounting flange 3a1 is formed on the lower edge portion of the conical portion 3a so as to protrude outward in a disk shape. A packing attachment flange 3a2 is formed on the upper side of the case attachment flange 3a1 so as to protrude outward in a disk shape.

<Base assembly 5>
In FIG. 10, the exploded view of the illuminating device S is shown.

  The base assembly 5 (see FIGS. 2 and 3) includes a cylindrical base 5a in which a screw is formed and an insulating plate 5b (see FIG. 10). The base 5a is made of aluminum or brass. The insulating plate 5b insulates the plus side and the minus side of the lighting device S.

  The lighting device S includes a protection circuit board 6 that protects the LED module 2a from overcurrent.

<Relationship between heat sink 1 for heat dissipation and pitch (interval) between fins 1b>
Next, the relationship between the heat sink 1 for heat dissipation and the pitch (interval) between the fins 1b will be described.

  FIG. 11 shows the relationship between the temperature rise of the LED module and its weight with respect to the fin pitch in the heat sink for heat dissipation. In FIG. 11, the horizontal axis represents the fin pitch (°), the left vertical axis represents the temperature rise value (° C.) of the LED module, and the right vertical axis represents the weight (g) of the heat sink 1 for heat radiation. The solid line in FIG. 11 shows the temperature rise value of the LED module with respect to the pitch of the fins 1b, and the broken line in FIG. 11 shows the weight of the heat sink 1 for heat dissipation with respect to the pitch of the fins 1b.

  The analysis conditions are the amount of heat generated by the entire LED module 2a 110w, the heat conductivity of the heat sink 96W / M · K, the emissivity 0.85 of the heat sink 1 for anodized heat treatment, the pitch of the fins 1b 5 °, 10 ° and 15 °. , 20 ° and 30 °.

  As shown by the solid line in FIG. 11, the temperature rise value of the LED module 2a decreases as the pitch of the fins 1b decreases. On the other hand, as shown by the broken line in FIG. 11, the heat sink 1 increases in weight as the pitch of the fins 1b decreases. In particular, when the pitch of the fins 1b is 10 ° or less, the weight of the heat sink 1 for heat dissipation is remarkably increased.

  Therefore, considering both weight reduction and heat dissipation capability of the heat sink 1 for heat dissipation, the pitch of the fins 1b is desirably around 8 to 15 °. Therefore, in this embodiment, a pitch of 10 ° between the fins 1b is selected.

<Assembly and installation of lighting device S>
Next, assembly of the lighting device S will be described.

  As shown in FIG. 10, the base assembly 5 to which the base 5a and the insulating plate 5b are fixed is formed.

  After the base assembly 5 is screwed to the base attachment portion 3 c of the main body support case 3, the crimping portion 5 a 1 (see FIGS. 2 and 5) of the base 5 a is crimped and fixed to the concave portion of the main body support case 3.

  On the other hand, the LED base substrate 2b on which the LED module 2 is mounted has four positioning protrusions 2b1 on the LED base substrate 2b on the inner surface of the top plate 1a1 of the case 1a of the heat sink 1. The LED base substrate 2b is positioned with respect to the case 1a by inserting the LED base substrate 2b into the notch portion 2b2 and screwing n5 into the notch portions 2b2.

  Then, the screw n3 is screwed into the case 1a of the heat sink 1 through the insertion hole of the LED base board 2b, and the LED base board 2b is fixed to the inner surface of the top plate 1a1 of the case 1a of the heat sink 1. .

  As shown in FIG. 7, the heat sink 1 for heat dissipation to which the LED base substrate 2b is fixed is fixed by the main body support case 3 and the screw n2 with the sealing packing 8 interposed therebetween.

  Thereafter, the translucent cover 4 is fixed to the lower end portion of the case 1a of the heat sink 1 for heat radiation by fastening the screws n1 at six places. Thereby, the illuminating device S shown in FIG. 2, FIG. 5 is assembled.

  As shown in FIG.1 (b), in order to attach the illuminating device S to the hanging tool k2 in the reflective shade k1, an operator puts a finger between the fins 1b protruding below the case 1a of the illuminating device S. Insert and hold the lighting device S. Then, the base 5a of the lighting device S is screwed to the hanging tool k2 in the reflection shade k1.

  Thereby, as shown to Fig.1 (a), the illuminating device S is attached to the hanging tool k2 in the reflective shade k1, is electrically connected with the power supply device k3, and functions as the luminaire K.

  According to the above configuration, a part of the plurality of LED modules 2a is arranged at a position overlapping the fin 1b, which is a heat radiating fin in plan view, so that the heat of the LED module 2a is transmitted to the fin 1b at a position where it overlaps well. Can dissipate heat.

  Further, more than half of the other LED modules 2a are not overlapped with the fins 1b of the heat radiating fins in a plan view, and are from the inner edge to the middle of the outer edge (line C1) (line C1) (see FIG. 6), the light from the LED module 2a can be efficiently reflected by the reflector 1ar to enhance the light distribution.

  Therefore, it is possible to improve the efficiency (= light flux (lm) / power consumption (W)) by setting the light distribution angle to 80 degrees to 100 degrees.

  Moreover, as shown in FIG. 2, the fin 1b which is a radiation fin is formed below the lower edge 1u of the case 1a. Therefore, the heat generated in the plurality of LED modules 2a can be radiated to the external space below by the fins 1b.

  In addition, as shown in FIG. 1 (b), when attaching and removing the lighting device S, an operator is formed below the lower edge 1u (see FIG. 2) of the case 1a and puts a finger between the fins 1b. The illumination device S can be easily attached and detached by holding the illumination device S easily and smoothly.

  Further, as shown in FIG. 4 and FIG. 5, the fin 1b, which is a heat radiating fin, is formed from the side edge 1s of the case 1a of the heat radiating heat sink 1 to the outside of the side. Heat can be radiated to the outside space on the side by the fins 1b.

  In addition, the case 1a of the heat sink 1 for heat dissipation has a reflector 1ar of a reflecting member outside the region where the LED module 2a of the LED base substrate 2b is disposed. The reflector 1ar is formed to be inclined from the inside toward the outside in the direction away from the LED module 2a in the direction of the central axis O of the lighting device S, and reflects the light of the LED module 2a toward the central axis O.

  Then, the dimension L1 from the LED mounting surface of the LED base substrate 2b in the central axis O direction to the edge of the farthest reflecting member, and the middle of the region where the plurality of LED modules 2a are arranged (line C1) ( There is a relationship of L1 ≧ L2 between the dimension L2 from the outer edge to the outer edge (see FIG. 6).

  Therefore, the light of the LED module 2a arranged outside the middle (line C1) (see FIG. 6) from the inner edge to the outer edge of the region where the plurality of LED modules 2a are arranged is efficiently reflected by the reflector 1ar and the central axis Can be collected in the O direction. Therefore, it is possible to further increase the illuminance.

  Further, between the plurality of fins 1b, three strength fins 1c of the strength member combined radiating fin formed from the center side to the fin 1b and formed above the fin 1b are formed at an interval of approximately 120 °. .

  By forming the three strength fins 1c at intervals of approximately 120 ° in this way, air containing heat generated by the LED module 2a is retained even when the lighting device S is installed directly beside or obliquely. It can escape smoothly and well upward.

  A plurality of fins 1b are formed on the heat sink 1 for heat dissipation, and the fin 1b has a protruding portion 1b2 that is a portion protruding below the lower edge 1u of the case 1a of the heat sink 1 for heat dissipation. The air around the illuminating device S is between the fin 1b and the adjacent fin 1b or between the fin 1b and the strength fin 1c adjacent to the fin 1b from the protruding portion 1b2 which is a portion protruding to the lower side of the lower edge 1u. Enters, is heated while exchanging heat with the fins 1b and the strength fins 1c, and flows upward. The air temperature in the vicinity of the outer surface of the heat sink 1 for heat radiation is lowest in the vicinity of the protruding portion 1b2, which is a portion protruding to the lower side of the lower edge 1u. Since the efficiency of heat exchange is high when the temperature difference between the outer surface of the heat sink 1 for heat dissipation and the air in the vicinity of the outer surface is large, by forming the protruding portion 1b2 that is a portion protruding below the lower edge 1u, Heat can be transferred to a portion where the air temperature in the vicinity of the outer surface of the heat sink 1 for heat dissipation is low and the efficiency of heat exchange is high, and heat dissipation can be improved. The inclined surface 1b1 is a part of the protruding portion 1b2.

  When the lighting device S is put in a lighting fixture such as a reflective shade, the upper side of the heat sink 1 for heat dissipation is covered with the reflective shade and obstructs convection and radiation. In comparison, heat dissipation is reduced. However, by providing a portion protruding below the lower edge 1u, the surface area near the air inlet to the heat sink 1 can be increased as compared to the case where there is no portion protruding below the lower edge 1u. Heat dissipation can be improved.

  If the heat dissipation is improved, the lifetime of the light source can be extended by suppressing the temperature rise of the light source, and the reliability of the lighting device can be improved. In addition, the luminous efficiency of the LED is temperature dependent, and when the light source temperature is lowered, the luminous efficiency of the LED is improved. Therefore, it is easy to provide an illumination device with reduced power consumption.

  The protruding portion 1b2, which is a portion protruding to the lower side of the lower edge 1u, is improved in heat dissipation as it extends longer to the lower side. However, since the optical loss due to light absorption by the protruding portion 1b2, which is a portion protruding below the lower edge 1u, increases, the heat sink 1 for heat dissipation 1 takes into account the weight reduction and the optical loss of the heat sink 1 for heat dissipation. It is desirable that the ratio of the length of the portion protruding below the lower edge 1u to the opening diameter is about 0.02 to 0.2. In order to prevent an increase in optical loss due to light absorption at the protruding portion 1b2, which is a portion protruding below the lower edge 1u, it is preferable to apply a paint having a high light reflectance. Further, by applying a paint having a high light reflectance and a high emissivity, the heat dissipation can be further improved.

  When the fin 1b has a structure having a lower edge 1u of the case 1a of the heat sink 1 for heat dissipation and a protruding portion 1b2 that protrudes below the translucent cover 4, the lighting device of the present invention is provided on a floor or a desk. When the is placed, since the protruding fins are used as a support and can be placed in a stable state, it is easy to handle and easy to construct.

  When the lighting device of the present invention is placed on a floor or a desk, the translucent cover 4 is not in direct contact with the floor, so that the translucent cover 4 is not easily damaged. Therefore, it is possible to prevent an increase in optical loss due to breakage of the translucent cover 4 or damage to the surface of the translucent cover 4.

  From the above, a highly efficient lighting device S can be realized.

  In addition, this invention is not limited to above-described embodiment, Various embodiments are included. For example, the above-described embodiment is a description of the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the configurations described. For example, a part of the configuration described may be included.

1 Heat sink for heat dissipation (heat sink)
1a case 1s side edge of case 1u lower edge of case 1ar reflector (reflective member)
1b Fin (radiating fin)
1b1 Inclined surface 1b2 Protruding part 1c Strength fin (Strength member combined heat dissipation fin)
2 LED board assembly 2a LED module (LED)
2a1 Inner edge 2a2 Outer edge 2b LED base substrate (substrate)
O Center axis c1 line (middle)
L1 Vertical dimension (dimension from the LED mounting surface of the board to the edge of the reflective member furthest away)
L2 distance (dimension from the middle of the area where a plurality of LEDs are arranged to the outer edge)
S Lighting device

Claims (4)

A heat sink having a substrate on which a plurality of LEDs are placed, a case to which the substrate is fixed, and a plurality of heat radiation fins formed on the outer surface of the case,
The said heat radiating fin has the protrusion part which is a part protruded rather than the lower edge of the said case, The illuminating device characterized by the above-mentioned. Inside the case, has a reflector having an inclined surface,
The lighting device according to claim 1, wherein the protrusion includes an inclined surface having an angle larger than an inclination angle of the reflector. The lighting device according to claim 1, wherein the heat radiation fin is formed from a side edge of the case to a side outward.   4. The lighting device according to claim 1, wherein a direct current power source is input.