WO2014027387A1 - Led lighting fixture - Google Patents

Description

LED lighting fixtures

The present invention relates to an LED lighting apparatus using an LED (light emitting diode) as a light source.

Currently, many lighting fixtures using LEDs as light sources have been provided in the market for the purpose of energy saving and long life. Even in a general LED lighting apparatus, how to efficiently dissipate the heat generated from the LED is a problem.
When dissipating heat from the LED, a flat fin-shaped heat radiation fin is often used in order to increase the heat radiation area.

As conventional examples in which heat is radiated from the LED using heat radiating fins, for example, Patent Documents 1 to 3 shown below can be cited.

JP 2006-40727 A JP 2010-733337 A JP 2011-14306 A

In these Patent Documents 1 to 3, heat dissipating fins are provided radially at predetermined intervals on the outer peripheral surface of a substantially cylindrical case in which a lighting circuit for driving and lighting the LED is mounted. The heat from is dissipated.

In the above-mentioned Patent Document 1, radiation fins having a knurled peripheral surface are continuously provided from the lower part of the flat fin-shaped radiation fins. There is a problem that the heat dissipation area cannot be increased and heat dissipation cannot be performed efficiently.

Also, in each of the above Patent Documents 2 and 3, a hemispherical glove is integrally provided below the flat fin-shaped heat dissipating fins to form a light bulb-type lighting fixture.

In each of the above Patent Documents 1 to 3, since the bottom surface of the space formed between the radiating fins and the radiating fins provided radially at predetermined intervals on the outer peripheral surface of the case is closed, air circulation However, it is not smooth, air tends to accumulate, and it is difficult to effectively dissipate the heat radiation fins.
With such a radiating fin, heat problems are likely to occur even in a small luminaire, and in particular, when a large-sized LED illumination is intended, a large number of LEDs are used as a light source. The issue is how to dissipate heat.

The present invention has been provided in view of the above-described problems, and improves air circulation in the space between the radiation fin and the radiation fin even when a flat fin-shaped radiation fin is used. Thus, an LED lighting apparatus intended to efficiently and effectively dissipate heat radiation fins is provided.

In the first aspect of the present invention, a plurality of light emitting diodes 42 for a light source, a substrate 40 on which the plurality of light emitting diodes 42 are mounted, a casing 20 in which the substrate 40 is disposed on the lower surface side, In the LED lighting apparatus provided with a plurality of flat plate-like heat radiation fins 23 provided radially at predetermined intervals on the outer peripheral surface,
The outer diameter of the lower portion of the outer edge portion in the radial direction of the radiating fin 23 is formed larger than the outer diameter of the lower portion of the casing 20,
A passage 63 is formed outside the outer peripheral surface of the lower portion of the casing 20 so that air for heat dissipation can be circulated.

The second aspect of the present invention is characterized in that the through-hole 63 is formed outside the bottom of the space 62 formed between the adjacent radiating fins 23 and 23.

In the third aspect of the present invention, the outer edge portion of the lower end portion of each of the radiating fins 23 and the ring-shaped ring 24 are connected to each other, and the inner edge side of the ring 24 is used as the opening 63. It is a feature.

In the fourth aspect of the present invention, the heat sink 50 is brought into close contact with the upper surface of the substrate 40, and the upper surface of the heat sink 50 and the lower surface of the casing 20 are brought into contact with each other.

The fifth aspect of the present invention is characterized in that the case body 19 composed of the casing 20 and the heat radiating fins 23 is made of magnesium.

According to the first aspect of the present invention, since the through holes 63 that allow the heat radiation air to flow are formed outside the outer peripheral surface of the lower portion of the casing 20, the heat radiating fins 23 are formed through the through holes 63. Since air flows upward to the side, air stagnation and accumulation in the space 62 between the radiating fins 23 can be eliminated, and the air flow can be made smooth. Thereby, compared with the case where there is no through-hole 63, it is possible to efficiently and effectively dissipate heat with the radiation fins 23.

According to the second aspect of the present invention, the through-hole 63 is formed by forming the through-hole 63 on the outside of the bottom of the space 62 formed between the adjacent radiating fins 23, 23. As a result, air flows upward into the bottom of the space portion 62, so that air stagnation and accumulation in the space portion 62 between the radiating fins 23 can be eliminated, and the air flow can be made smooth. Thereby, it is possible to efficiently and effectively dissipate heat with the radiation fins 23.

According to the third aspect of the present invention, the outer edge portion of the lower end portion of each of the radiating fins 23 is connected to the ring-shaped ring 24, and the inner edge side of the ring 24 is used as the opening 63. Thus, it is possible to improve the heat radiation effect by the heat radiation fins 23 and to maintain the rigidity of each heat radiation fin 23.

According to the fourth aspect of the present invention, the heat sink 50 is brought into close contact with the upper surface of the substrate 40, and the upper surface of the heat sink 50 and the lower surface of the casing 20 are brought into contact with each other. The heat transferred through the heat sink 50 and the casing 20 can be efficiently and effectively radiated by the heat radiating fins 23.

According to the fifth aspect of the present invention, the case body 19 composed of the casing 20 and the heat dissipating fins 23 is made of magnesium, so that heat can be radiated efficiently and at the same time weight reduction can be realized. be able to. It is a suitable example especially in a large luminaire.

It is sectional drawing of the lighting fixture main body in embodiment of this invention. It is a bottom view of the lighting fixture main body in the embodiment of the present invention. It is a top view of the case main body in embodiment of this invention. FIG. 4 is a cross-sectional view taken along the line AA in FIG. 3 in the embodiment of the present invention. It is a bottom view of the case body in the embodiment of the present invention. It is a bottom view of the LED aluminum substrate in embodiment of this invention. (A) and (b) are the top views and sectional drawings of a heat sink in an embodiment of the invention. (A) and (b) are the bottom view and sectional drawing of the lens main body in embodiment of this invention. FIG. 9A is a plan view of a lens presser according to an embodiment of the present invention, and FIG. 9B is a cross-sectional view taken along the line AA in FIG. It is a bottom view of the lens holder in an embodiment of the invention. (A) to (c) are cross-sectional views of the lens body when the aperture angle in the embodiment of the present invention is changed. It is a block diagram of the power supply unit in the embodiment of the present invention. It is a specific circuit diagram of the AC input unit in the embodiment of the present invention. It is a specific circuit diagram of the DC converter circuit in the embodiment of the present invention. It is a specific circuit diagram of an output current control circuit, a feedback circuit, and an ambient temperature detection circuit in an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a cross-sectional view of a luminaire main body 1 using a number of LEDs as a light source, and FIG. 2 shows a bottom view of the luminaire main body 1.
As shown in FIG. 1, the outer shell of the luminaire main body 1 has a substantially cylindrical tubular body 10 having a base 11 provided at the upper end, and a substantially cylindrical casing connected and fixed to the lower portion of the tubular body 10. The case main body 19 is provided with a plurality of heat dissipating fins 23 on the outer peripheral surface 20. The cylinder body 10 is opened at the lower surface and is slightly expanded toward the lower side, and is made of resin.

The casing 20 of the case body 19 is open at the upper and lower surfaces and slightly expands toward the lower portion. A connecting portion 21 is integrally formed on the inner side of the upper portion of the casing 20. Hole 22 is threaded. On the other hand, a mounting piece 12 is integrally formed on the outer side of the lower part of the cylindrical body 10, and the cylindrical body 10 is inserted from the lower side to the upper side of the casing 20 and attached to the lower surface of the connecting portion 21 via the O-ring 2. The upper surface of the piece 12 is brought into contact. And the screw | thread 3 is inserted through the hole drilled in the attachment piece 12 of the cylinder 10, and this casing 3 is screwed by the screw hole 22 of the said connection part 21, The casing 20 is the lower end side of the cylinder 10. It is fixed to the link.

Next, the configuration of the case body 19 will be described. 3 is a plan view of the case main body 19, FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3, and FIG. On the outer peripheral surface of the substantially cylindrical casing 20 constituting the case main body 19, a plurality of radiating fins 23 are formed integrally with the casing 20 radially at regular intervals. Further, a ring 24 is formed so as to be integrally connected to the outer edge portion of the lower end portion of each radiating fin 23, and each ring 24 and the lower end outer edge portion of each radiating fin 23 are connected to each other. The rigidity of the radiating fins 23 is maintained.
In the present embodiment, the number of radiating fins 23 is 16. However, the number of radiating fins 23 can be set to an arbitrary number.

As shown in FIG. 1, a power supply unit 25 made of a substrate for turning on an LED is disposed in the upper part of the casing 20, and a pair of power supply lines is provided between the input side of the power supply unit 25 and the base 11. 26 is connected, and commercial power is supplied from the base 11 to the power supply unit 25 through the power line 26. Further, a lead wire 27 connected to the LED side is led out from the power supply unit 25.

Further, as shown in FIGS. 1 and 4, a ring-shaped flange 30 is integrally formed on the lower edge of the casing 20 so as to extend outward, and an LED (described later) is formed on the lower surface side of the flange 30. An LED aluminum substrate 40 mounted with a light emitting diode (42), a heat sink (heat sink) 50, a cover 60, a lens body 70, and the like are attached.

FIG. 6 shows a bottom view of the LED aluminum substrate 40. The LED aluminum substrate 40 is made of aluminum as a substrate material in order to improve heat dissipation of the LED, and is substantially spirally wound on the lower surface of the aluminum substrate via an insulating layer. A shaped electrode pattern 41 is formed.
A plurality of LEDs 42 are mounted on the electrode pattern 41, and each LED 42 is connected in series in terms of electrical circuit. In the present embodiment, the number of LEDs 42 is 30, but can be arbitrarily set according to the application and capacity.

Further, a recess 43 for positioning when the LED aluminum substrate 40 is attached to the lower surface opening of the casing 20 is formed at one position on the edge of the LED aluminum substrate 40. As shown in FIG. 5, positioning ribs 31 corresponding to the positioning recesses 43 project inward from the lower surface side of the flange portion 30 of the casing 20.
Further, a hole 44 is formed in the central portion of the LED aluminum substrate 40 so that the leading end portion of the lead wire 27 from the power supply unit 25 is inserted and connected to the electrode pattern 41.

In addition, the notch 45 is formed in the peripheral portion of the LED aluminum substrate 40 by notching at regular intervals. The cutout 45 is open to the outside and is formed in a substantially U shape. The cutout 45 is for inserting a screw 46 (see FIG. 1) for attaching the LED aluminum substrate 40 to the lower surface of the casing 20.

7 shows an aluminum heat sink 50, FIG. 7A shows a plan view of the heat sink 50, and FIG. 7B shows a cross-sectional view of the heat sink 50. The heat sink 50 is for diffusing the heat of the LED aluminum substrate 40, and as shown in FIG. 1, the heat sink 50 is brought into close contact with the upper surface of the LED aluminum substrate 40 to dissipate heat.

The heat sink 50 is formed in the same shape as the LED aluminum substrate 40, and a positioning recess 51 is formed at the edge of the heat sink 50 in the same manner as the recess 43 of the LED aluminum substrate 40. .
Further, a hole 52 through which the lead wire 27 is inserted is formed in the central portion of the heat sink 50, and a screw 46 having the same function as the cutout portion 45 of the LED aluminum substrate 40 is inserted in the peripheral portion of the heat sink 50. A cutout 53 is formed in the cutout.

The heat sink 50 is placed on the upper surface of the LED aluminum substrate 40, the upper and lower recesses 43, 51 and the notches 45, 53 are aligned, and the LED aluminum substrate 40 and the heat sink 50 are placed on the lower surface of the flange portion 30 of the casing 20. The ribs 31 for positioning the casing 20 are inserted into the upper and lower recesses 43 and 51.
Then, the screw 46 is screwed into the screw hole 32 formed on the lower surface of the flange portion 30 through the upper and lower cutout portions 45 and 53 from below, so that the LED aluminum substrate 40 and the heat sink 50 are attached to the flange portion 30 of the casing 20. It is attached and fixed to the lower surface.

By the way, in order to increase the size of the LED illumination, in order to use a large number of LEDs as the light source, how to dissipate heat generated from the LEDs becomes a problem. Conventionally, the heat dissipation structure is formed of aluminum or an aluminum alloy, but the weight and volume hinder the increase in size.
Therefore, in the present embodiment, aluminum having good thermal conductivity is used for the constituent material (LED aluminum substrate 40) in the periphery of the LED 42, and the case main body 19 serving as a heat radiating member connected to the aluminum is heat-transmitting / heat-transmitting. The structure uses good magnesium.

That is, an LED aluminum substrate 40 is used as a substrate on which the LEDs 42 are mounted, and an aluminum heat sink 50 is provided on the upper surface of the LED aluminum substrate 40 to promote the heat dissipation action. Further, the case body 19 made of the casing 20 and the heat radiating fins 23 is made of magnesium, and heat diffusion is performed between the casing 20 and the heat radiating fins 23. Moreover, weight reduction can be realized, which is a preferable example particularly in a large luminaire.
As described above, by providing the plurality of heat radiation fins 23 on the outer peripheral surface of the casing 20, it is possible to increase the heat radiation area, and therefore it is possible to increase the size by using a large number of LEDs 42.

Here, in the present embodiment, the configuration of the heat dissipating fins 23 is as follows, so that the heat dissipated by the heat dissipating fins 23 can be dissipated more efficiently and effectively.
As shown in FIGS. 1 and 2, the dimension of the radially outer lower portion of each radiating fin 23 formed flat and fin-shaped is larger than the outer diameter of the casing 20 and the outer diameter of a lens retainer 80 described later. Forming. That is, the outer diameter of the lower portion of the outer edge portion in the radial direction of the radiating fin 23 is formed larger than the outer diameter of the lower portion of the casing 20. In addition, the lower end surface of the heat radiating fin 23 and the lower surface of the lens retainer 80 and a lens body 70 described later are substantially at the same position.

Here, a space 62 is formed between the adjacent heat radiating fins 23 and the heat radiating fins 23, and the space 62 is communicated with a space below the space 62 and the radiating fins 23 at a lower portion outside the space 62. A through hole 63 is formed.
In the present embodiment, since the upper surface of the ring 24 and the lower edge of the radiating fin 23 are connected to each other, a substantially arc-shaped through hole 63 is formed between the inner edge of the ring 24 and the outer edge of the lower portion of the casing 20. Will be.

Here, as shown in FIG. 2 and FIG. 3, through holes 63 are respectively formed on the outer sides of the bottom portions of the space portions 62 between the adjacent radiating fins 23. The through-hole 63 is a horizontally long rectangle and has an arc shape. Further, as shown in FIG. 1, the portion of the luminaire main body 1 is opened below the opening 63 without being present, and the air smoothly flows into the space 62 between the radiating fins 23 through the opening 63. To flow into.

Thus, as shown by the arrow a in FIG. 1, air flows upward into the bottom portion of the space portion 62 through the through-hole 63, so that air stagnation and accumulation in the space portion 62 between the radiation fins 23. The flow of air can be made smooth. Thereby, the heat transmitted from the LED aluminum substrate 40 via the heat sink 50 and the casing 20 can be efficiently and effectively radiated by the heat radiating fins 23.
In addition, when there is no through-hole 63, it becomes easy to produce the stagnation and accumulation | storage of the air in the space part 62 similarly to the case of a prior art example, and it is difficult to radiate the radiation fin 23 efficiently.

Moreover, the outer edge part of the lower end part of each radiation fin 23 and the ring-shaped ring 24 are connected, respectively, and the heat radiation effect by the radiation fin 23 is improved by using the inner edge side of the ring 24 as the opening 63. At the same time, the rigidity of each radiating fin 23 can be maintained.

In addition, in order to enlarge the area of the through-hole 63, by eliminating the ring 24, it is possible to flow more air from below to the radiation fins 23 and to further dissipate the radiation fins 23.
However, from the viewpoint of maintaining the rigidity of each radiation fin 23, it is preferable to provide the ring 24.

The lower surface of the lower portion of the flange portion 30 of the casing 20 is used as a mounting surface 33 (see FIG. 4). As shown in FIG. 1, the mounting surface 33 has a light-transmitting, for example, transparent, disc-shaped cover 60. It is bonded and fixed through. By disposing the cover 60 on the attachment surface 33 on the lower surface of the flange portion 30 of the casing 20, the LED aluminum substrate 40 is placed and sealed, and functions of moisture and dust can be imparted. The cover 60 can prevent the LED 42 on the LED aluminum substrate 40 from coming into direct contact, and can prevent damage to the LED 42 caused by the contact.

In addition, by arranging the cover 60, it is possible to use the LED lighting fixture without the lens body 70 as it is without using the lens body 70 described later.

By the way, although many LED lighting fixtures are simply using several LED for a light source, it may want to narrow down and use the light beam from a light source by the use of an LED lighting fixture.
When narrowing light rays from a luminaire that uses multiple LEDs as light sources, a lens is generally used to narrow down the light rays or diffuse the light rays. However, in conventional products, the lens and the LED light source are integrated. It was commercialized.

And, when changing the aperture angle of the light beam, conventionally, the part where the lens and the LED light source are integrated is replaced as a replacement part. Therefore, it becomes complicated when replacing the replacement part, and an LED light source is required in addition to the lens according to the type of the aperture angle of the light beam, and the cost of the replacement part is increased by the amount of the LED light source. is there.

Therefore, the lens main body 70 in which the aperture angle of the light beam from the LED 42 can be easily changed will be described. FIG. 8 shows a lens body 70 that is transparent and formed of an acrylic resin, FIG. 8A shows a bottom view of the lens body 70, and FIG. 8B shows a cross-sectional view of the lens body 70.
A substantially hemispherical lens portion 71 is formed on the lower surface of the lens body 70 corresponding to the position of the LED 42 on the LED aluminum substrate 40 by the number of LEDs 42. In addition, positioning ribs 72 are integrally formed outward at the edge of the lens body 70.

As shown in FIG. 1, the lens body 70 is disposed in contact with the lower surface of the cover 60, and the lens body 70 is attached to the casing 20 by the lens holder 80 shown in FIGS. 1, 9, and 10. It is attached to the lower surface of the part 30.
9A is a plan view of the lens retainer 80, FIG. 9B is a cross-sectional view taken along the line AA of FIG. 9A, and FIG. 10 is a bottom view of the lens retainer 80.

As shown in FIG. 9, the lens presser 80 is formed in a substantially ring shape, and has a large opening 81 for exposing each lens portion 71 of the lens body 70. A ring-shaped portion below the lens presser 80 serves as a support portion 84 that supports and fixes the lens body 70.
Further, the periphery of the lens retainer 80 has a substantially U-shaped cross section, and screw holes 82 are threaded at a constant interval. Further, a positioning recess 83 into which the rib 72 of the lens body 70 is fitted is formed on the inner side of the peripheral edge of the lens presser 80.

As shown in FIGS. 1 and 5, a hole 34 through which the screw 5 to be screwed into the screw hole 82 is inserted is formed at a position corresponding to the screw hole 82 in the flange portion 30 of the casing 20.

Accordingly, the lens portion 71 of the lens body 70 is inserted into the opening 81 of the lens holder 80, the peripheral portion of the lens body 70 is supported on the upper surface of the support portion 84 of the lens holder 80, and the flange portion 30 of the casing 20 is supported. The lens body 70 can be easily attached to the lower surface side of the casing 20 by screwing the screw 5 from above into the screw hole 82 of the lens holder 80 through the hole 34.

Light rays from the respective LEDs 42 are irradiated downward through the respective lens portions 71 of the lens body 70, and the diffusion angle in this irradiation is appropriately reduced according to the curvature of the lens portion 71 and irradiated. It will be.

FIG. 11 shows the lens body 70 when the aperture angle of the light beam is changed. FIG. 11A is the same as that in FIG. 8B. In this lens body 70, the curvature of each lens portion 71 is large. The angle is set narrower. FIG. 11B shows a case where the curvature of the lens unit 71 is made smaller than in FIG. 11A and the irradiation angle is made wider than in the case of FIG. (C) is a case where the curvature is further reduced and the irradiation angle of the light beam from the LED 42 is increased.

In the case of FIG. 11, although three types of aperture angles are used, a large number of lens bodies 70 may be prepared in advance in order to obtain a larger aperture angle. In such a case, it is only necessary to loosen the screw 5 and remove the lens retainer 80 and the lens body 70 from the casing 20 and replace only the lens body 70 having the lens portion 71 having a different aperture angle. The corner can be changed.

By the way, the LED lighting fixture is equipped with a function of shutting down the power supply by stopping energization of the LED in order to prevent damage to electronic components when the ambient temperature rises abnormally, for example, abnormally. Was the way.
In such a case, the user of the LED lighting apparatus does not know what caused the LED to be turned off, and gives the user anxiety.

Thus, in the present embodiment, the temperature detection function for detecting the temperature of the atmosphere in the power supply unit 25 and the control to gradually power down without stopping the energization to the LED 42 as in the conventional case when an abnormal temperature rise is detected. By installing the function, the minimum illuminance is provided even in an abnormal environment, and the user of the LED lighting apparatus is prevented from feeling uneasy.

FIG. 12 is a block diagram of the power supply unit 25, in which AC 100V power is supplied to the input side terminals T1 and T2 via the base 11, and the LED aluminum substrate 40 is supplied with power from the output side terminals T3 and T4. The LED 42 mounted on is driven to turn on.
Here, the LED 42 mounted on the LED aluminum substrate 40 and connected in series is referred to as an LED unit 47 for convenience of explanation. That is, the LED unit 47 is a circuit portion in which a plurality (30 in this embodiment) of LEDs 42 are connected in series in terms of electrical circuit.

As shown in FIG. 12, the power supply unit 25 includes an AC input unit 90 to which commercial power is input, a DC converter circuit 91 driven by the power from the AC input unit 90, and an output from the DC converter circuit 91. Accordingly, the LED unit 47 is driven at a constant current in a normal state, and an output current control circuit 92 that limits a current flowing in the LED unit 47 in an abnormal state, an ambient temperature detection circuit 93 that detects an ambient temperature in the power supply unit 25, and this atmosphere When an abnormal rise in ambient temperature is detected by the temperature detection circuit 93, a feedback circuit 94 is provided that feeds back the signal to the DC converter circuit 91 to power down the output power of the output current control circuit 92.

FIG. 13 shows a specific circuit diagram of the AC input unit 90. The applied AC 100V is full-wave rectified by the diode bridge DB, smoothed by the capacitor C1, and a DC voltage is output from the terminals a and b.
FIG. 14 shows a specific circuit diagram of the DC converter circuit 91, which includes an oscillation transformer L1, a switching element Q1, and an IC 1 that adjusts (feeds back) power using a 1-pin signal as a control terminal. The terminals a and b in FIG. 13 and the terminals a and b in FIG. 14 mean that the same symbols are connected to each other.

FIG. 15 is a specific circuit diagram of the output current control circuit 92, the ambient temperature detection circuit 93, and the feedback circuit 94, and the symbols c to g are connected in the same manner as described above. The output current control circuit 92 includes IC2, a transformer L2, and the like, and a constant current flows from the output side of the transformer L2 to the LED unit 47 via terminals T3 and T4.
The ambient temperature detection circuit 93 includes a transistor Q3, a thermistor TH that detects the ambient temperature, and the feedback circuit 94 includes a photocoupler PC1.

Next, a description will be given of a control operation for gradually powering down the LED 42 without stopping energization when an abnormal temperature rise is detected. First, in FIG. 15, when the ambient temperature rises, the resistance value of the thermistor TH decreases, and as a result, the transistor Q3 is turned on. When the transistor Q3 is turned on, the value of current flowing through the light emitting diode of the photocoupler PC1 increases. As a result, the impedance of the phototransistor on the light receiving side of the photocoupler PC1 is lowered.

When the impedance of the phototransistor of the photocoupler PC1 decreases, the collector current of the transistor Q2 shown in FIG. 14 decreases. As a result, the collector potential of the transistor Q2 rises and the intermediate potential between the resistor R1 and the resistor R2 rises. As a result, the voltage at the 1st pin of the IC1 increases.
When the voltage at pin 1 of IC1 rises, a signal is output from pin 7 that is the output terminal of IC1 in a direction that reduces the on-time of switching element Q1. As a result, the voltage between the diode D3 and the resistor R3 shown in FIG. 15 drops.

Then, the output voltage of the terminal T3 decreases via the transformer L2. As a result, the output current that is output from the terminal T3 and drives the LED unit 47 also decreases, and the power is reduced. As a result, even if the ambient temperature rises, the output current is reduced without stopping energization of the LED unit 47, and the minimum illuminance is maintained even in an abnormal environment.

That is, when the ambient temperature in the power supply unit 25 increases and the resistance value of the thermistor TH decreases, the output power supplied to the LED unit 47 decreases. When the output is reduced, the amount of heat generation is reduced and the ambient temperature is lowered, so that the resistance value of the thermistor TH is increased and the output is increased by a control operation opposite to the above operation.

In this way, when an abnormal temperature rise is detected by the power supply unit 25, the control is performed to gradually power down the LED 42 without stopping the energization as in the conventional case. Provides a minimum illuminance and does not give anxiety to users of LED lighting fixtures. At the same time, damage to electronic components can be prevented.

In addition, as an example of illustration, AC100V is used as the power supply voltage supplied to the LED lighting apparatus, but the present invention is also applicable to AC200V and AC220V in addition to AC100V.

19 Case body 20 Casing 23 Radiation fin 24 Ring 40 Substrate (LED aluminum substrate)
42 Light Emitting Diode (LED)
50 heat sink 62 space 63 opening

Claims (5)

A plurality of light emitting diodes (42) for a light source, a substrate (40) on which the plurality of light emitting diodes (42) are mounted, a casing (20) having the substrate (40) disposed on the lower surface side, and the casing ( 20) In the LED lighting apparatus provided with a plurality of flat plate-like heat radiation fins (23) provided radially at predetermined intervals on the outer peripheral surface,
The outer diameter of the lower portion of the outer edge portion in the radial direction of the radiating fin (23) is formed larger than the outer diameter of the lower portion of the casing (20),
An LED lighting apparatus, wherein a through hole (63) through which heat-dissipating air can flow is formed outside an outer peripheral surface of a lower portion of the casing (20). The said opening (63) is formed in the outer side of the bottom part of the space part (62) formed between the said adjacent radiation fins (23) (23), The feature of Claim 1 characterized by the above-mentioned. LED lighting fixtures. The outer edge part of the lower end part of each said radiation fin (23) and the ring-shaped ring (24) are each connected, The inner edge side of the said ring (24) is used as the said opening (63). The LED lighting apparatus according to claim 1. The LED according to claim 1, wherein a heat sink (50) is closely attached to an upper surface of the substrate (40), and an upper surface of the heat sink (50) and a lower surface of the casing (20) are brought into contact with each other. lighting equipment. The LED lighting device according to claim 1, wherein a case main body (19) comprising the casing (20) and the radiation fin (23) is formed of magnesium.

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