JP2011150936A - Led lighting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED lighting device capable of securing a stable voltage without specially providing a power supply for a cooling-means drive part driving a cooling means, and a lighting system using the LED lighting device. <P>SOLUTION: The LED lighting device includes a DC power supply 2, a series circuit 5 connected between output terminals of the DC power supply 2 and having a plurality of connected LEDs 4 , and a cooling means drive part 6 branched from the series circuit 5 and connected between at least two LEDs 42 to cool heat generated by the LEDs. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an LED lighting device and an illuminating device including a driving circuit for a cooling unit that cools an LED as a light source.

  Recently, LEDs have been used as light sources for lighting devices. As the temperature of the LED increases, the light output decreases and the useful life is shortened. For this reason, it is important for an illuminating device using an LED as a light source to suppress an increase in the temperature of the LED in order to extend the service life or improve the characteristics of light emission efficiency.

  In particular, as the output of LEDs increases, further temperature rise needs to be suppressed. For this reason, for example, an LED bulb has been proposed that incorporates means used in the form of a fan that causes forced air cooling in the bulb (see, for example, Patent Document 1).

Japanese Patent No. 4290887

  However, what is disclosed in the above-mentioned Patent Document 1 is only abstractly described as a form of a fan that causes forced air cooling. For example, there is no specific description about securing a drive power source for driving the fan. Disclosure is not made.

  The present invention has been made in view of the above problems, and an LED lighting device capable of securing a stable voltage and a lighting device using the LED lighting device without specially providing a power source for a cooling means driving unit that drives the cooling means. The purpose is to provide.

The LED lighting device according to claim 1 includes: a DC power source; a series circuit connected between output terminals of the DC power source, and a plurality of LEDs connected; and at least one or more branched from the series circuit A cooling means driving unit that is connected between the LEDs and cools the heat generated by the LEDs.
The DC power source includes a case where a commercial AC power source is received to generate a DC power source and a case where a battery is applied.

  For example, when a fan is used as the cooling means, the cooling means driving unit drives a fan motor, and when a semiconductor element such as a Peltier element is used, a driving circuit for driving the fan motor is applied. The drive unit can be constituted by a power supply unit that supplies power to a fan or the like, a control unit that controls the operation of the fan or the like, various sensors, and the like, but the present invention is not limited to this, and various types are allowed. . The driving unit can also be configured using an IC.

The LED lighting device according to claim 2 is the LED lighting device according to claim 1, wherein the plurality of LEDs are mounted on a substrate, and the plurality of LEDs are configured such that a bare chip of the LED is directly mounted on the substrate. The cooling unit driving unit is connected to both ends of at least one LED of the surface-mounted LED packaged with the LED bare chip. It is characterized by being.
With this configuration, it is possible to dispose the LED mounted in a desired position on the surface mounting method in which the luminance decreases.
An illumination device according to a third aspect includes an apparatus main body; and the LED lighting device according to the first or second aspect, which is disposed in the apparatus main body.
The lighting device includes a light source, a lighting fixture used indoors or outdoors, a display device, and the like.

  According to the first aspect of the present invention, there is provided an LED lighting device that can effectively suppress the temperature rise of the LED and that can secure a stable voltage without providing a special power source in the cooling means driving unit. can do.

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, since the LED whose luminance is reduced is mounted by the surface mounting method, the degree of freedom of arrangement is high, and the LED is placed at a desired position. It becomes possible to arrange.
According to the invention described in claim 3, it is possible to provide an illuminating device that exhibits the effects of the invention of the above-mentioned claim.

It is a circuit block diagram which shows the LED lighting device which concerns on the 1st Embodiment of this invention. It is a front view which shows the lightbulb-type LED lamp as the illumination device. It is a front view which shows the principal part of the bulb-type LED lamp in a cross section. It is a top view which shows the light source part of the bulb-type LED lamp. It is a circuit block diagram which shows the LED lighting device which concerns on 2nd Embodiment of this invention. It is a top view which shows the light source part of the bulb-type LED lamp.

Hereinafter, an LED lighting device and a lighting device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a circuit configuration diagram showing an outline of an LED lighting device, and FIGS. 2 to 4 show a light bulb-shaped LED lamp as a lighting device incorporating the LED lighting device.
As shown in FIG. 1, the LED lighting device 1 includes a DC power source 2 and a lighting circuit 3 that receives an output from the DC power source 2 and lights an LED.

  The DC power source 2 is connected to a commercial AC power source AC, and receives the AC power source AC to generate a DC output. The commercial AC power supply AC is connected to the input terminal of the full-wave rectifier circuit 21, and a smoothing capacitor 22 is connected between the output terminals of the full-wave rectifier circuit 21. Instead of the smoothing capacitor 22, a power factor correction circuit mainly including a boost chopper may be used. A DC voltage conversion circuit 23 and current detection means 24 are connected to the smoothing capacitor 22. The DC power supply 2 has a control function of feeding back a current control signal to the DC voltage conversion circuit 23 according to the detection result of the current detection means 24 in order to make the output current constant.

  The DC voltage conversion circuit 23 can be composed of a step-down chopper, a step-up chopper, a DC-DC converter, and the like. In this case, the ON period and the ON / OFF frequency of a switching element such as a chopper are controlled by the feedback control. Thus, a constant current can be achieved. The DC power supply may be a constant voltage or a constant power, or may be an output that is intermittently generated as in PWM control.

  A lighting circuit 3 is connected to such a DC power supply 2. The lighting circuit 3 includes a series circuit 5 connected between output terminals of the DC power source 2 and a plurality of LEDs 4 connected in series, and a cooling means driving unit 6.

  As described later, the LED 4 has a plurality of LED bare chips mounted directly on the substrate, that is, the LED 41 mounted in a chip-on-board manner, and the LED bare chips are packaged and surface-mounted, that is, It consists of LED42 mounted by the surface mounting system, these are connected in series as a whole, and the series circuit 5 is comprised.

  The LED 41 mounted in a chip-on-board system is configured by connecting a plurality of series circuits each having a plurality of LEDs 41 connected in series, in parallel. On the other hand, two LEDs 42 mounted by the surface mounting method are connected, for example, one end side is connected to the LED 41 and the other end side is connected to the DC power source 2.

  The cooling means driving unit 6 is branched and connected from the series circuit 5 of the LED 41 and the LED 42. Specifically, one end side of the cooling means driving unit 6 is connected to a connection point between the LED 41 and the LED 42, and the other end side is connected to the DC power source 2. The cooling means driving unit 6 is composed of an IC or the like, and is connected to a fan motor 7 constituting the cooling means, and has a function of supplying DC power to the fan motor 7 and driving and controlling the fan motor 7. ing.

  The cooling means driving unit 6 is connected to a temperature detecting means 8 composed of a temperature detecting element such as a thermistor. The temperature detection means 8 detects the temperature of the LED 4 and outputs a detection signal to the cooling means drive unit 6. The cooling means driving unit 6 receives the detection signal and controls driving of the fan motor 7.

Meanwhile, the forward voltage V _F of a single LED is about 3 to 4V, the forward voltage V _F is known to be substantially constant with respect to the input-side voltage fluctuation of. In LED4 in this embodiment, the forward voltage _{V F} is using of about 3V.
On the other hand, the cooling means driving unit 6 requires a DC voltage of about 6 V as a DC power source for driving the fan motor 7.

As described above, the cooling unit drive unit 6, because it is connected is branched from the series circuit 5 of the LED41 and the LEDs 42, 2 pieces of the sum of the forward voltage _{V F} of the LEDs 42 to the cooling means driving section 6, That is, a stable DC voltage of about 6V is supplied. Therefore, specially separately without providing the power, the stable DC voltage using the forward voltage V _F of the LED4 can be supplied to the cooling means driving unit 6.

  Operation | movement of the LED lighting device 1 comprised as mentioned above is demonstrated. When the power is turned on, a direct current output is supplied from the direct current power source 2 to the lighting circuit 3, and the LEDs 4 are turned on all at once. The fan motor 7 is driven by the output of the cooling means driving unit 6 when the temperature detecting means 8 detects a temperature rise of the LED 4 above a certain level. Therefore, when the temperature of the LED 4 rises above a certain level, the fan motor 7 is driven, and the LED 4 is cooled by the air blowing, and the temperature rise is suppressed.

Further, between the two LED42 ends of a stable DC voltage of about 6V by each of the forward voltage V _F has occurred, the DC voltage is supplied to both ends of the cooling means driving unit 6. Therefore, the fan motor 7 is driven stably.

In the above configuration, the LED 4 is described as being configured by the LED 41 mounted by the chip-on-board method and the LED 42 mounted by the surface-mount method. However, the LED 4 is mounted by the chip-on-board method. You may comprise only LED41. In this case, similarly to the above, the cooling means driving unit 6 may be connected by branching from the series circuit of the LEDs 41 so that a predetermined DC voltage can be secured. Further, the branch point of the series circuit 5 to which the cooling means driving unit 6 is connected may be appropriately selected according to the voltage required by the cooling means driving unit 6.
Next, a bulb-type LED lamp 10 incorporating the LED lighting device 1 will be described with reference to FIGS.

  As shown in FIGS. 2 and 3, the LED lamp 10 includes a substantially cylindrical main body case 11, a light source unit 12 disposed in the main body case 11, a fan motor 7 constituting the cooling means, and the lighting device 1. The cover member 13 is connected to one end of the main body case 11, the base 14 is attached to the cover member 13, and the globe 15 is attached to the main body case 11 so as to cover the light source unit 12.

The main body case 11 is made of, for example, a metal material such as aluminum having good thermal conductivity, and has a substantially cylindrical shape that is gradually expanded in diameter from one end side toward the other end side. A plurality of exhaust ports 11b are formed on the other end side of the port 11a. The intake port 11a and the exhaust port 11b pass through the inside and outside of the main body case 11, have a vertically long elliptical shape, and are formed at substantially equal intervals in the circumferential direction. The formation positions of the intake port 11a and the exhaust port 11b are shifted from each other so that the flow of outside air from the intake port 11a to the exhaust port 11b can be diffused.

A plurality of mounting ribs 11c are formed on the other end side of the main body case 11 from the outer peripheral side to the inner peripheral side, and a heat radiating plate 16 made of a metal material such as a circular plate-like aluminum is mounted on the mounting rib 11c. Is installed and installed.
The light source unit 12 includes a substrate 17, a plurality of LEDs 4 (LEDs 41 and 42) mounted on the substrate 17, a frame member 12a, and a sealing member 12b.

  The substrate 17 is formed in a substantially circular shape and is attached so as to be in close contact with the heat radiating plate 16. In order to improve the heat dissipation of each LED 4, it is preferable to apply a metal material having good heat conductivity such as aluminum and excellent heat dissipation to the substrate 17 as the base plate. In the present embodiment, a metal base substrate in which an insulating layer is laminated on one surface of an aluminum base plate is used as such a substrate 17. When the base plate is made of an insulating material, a ceramic material or a synthetic resin material having relatively good heat dissipation characteristics and excellent durability can be used.

  A plurality of LEDs 41 are mounted on the insulating layer of the substrate 17 by a chip-on-board method. The plurality of LEDs 41 are LED bare chips. For example, an LED bare chip that emits blue light in order to cause white light to be emitted from the light emitting unit is used. This LED bare chip is bonded onto the substrate 17 using a silicone resin adhesive. The plurality of LEDs 41 are arranged in a matrix to form a plurality of columns, for example, six columns.

  An LED bare chip is, for example, an InGaN-based element, in which a light-emitting layer is stacked on a light-transmitting sapphire element substrate, and the light-emitting layer includes an n-type nitride semiconductor layer, an InGaN light-emitting layer, and a p-type nitride layer. A physical semiconductor layer is sequentially stacked. And the electrode for sending an electric current through a light emitting layer was formed with the p-type electrode pad on the p-type nitride semiconductor layer, and the n-type electrode pad on the n-type nitride semiconductor layer. It consists of a negative electrode. These electrodes are electrically connected by bonding wires. The bonding wires are made of fine gold (Au) wires and are connected via bumps mainly composed of gold (Au) in order to improve mounting strength and reduce damage to bare LED chips.

  The frame member 12a is bonded onto the substrate 17 by, for example, applying uncured silicone resin having a predetermined viscosity on the substrate 17 in a frame shape using a dispenser and then heat-curing it. The frame member 12a is applied in a square shape, and the LEDs 41 are disposed inside the frame member 12a surrounded by the inner peripheral surface. That is, the mounting area of the LED 41 is surrounded by the frame member 12a.

  The sealing member 12b is made of a translucent synthetic resin, for example, a transparent silicone resin, is filled on the inner side of the frame member 12a, is provided on the substrate 17, and seals the mounting area of the LED 41.

The sealing member 12b contains an appropriate amount of phosphor. The phosphor is excited by the light emitted from the LED 41 and emits light of a color different from the color of the light emitted from the LED 41. In the present embodiment in which the LED 41 emits blue light, a yellow phosphor that emits yellow light that is complementary to the blue light is used as the phosphor so that white light can be emitted. Yes. The sealing member 12b is provided by being heat-cured after being injected into the frame member 12a in a predetermined amount in an uncured state. Therefore, the sealing area of the sealing member 12a is defined by the frame member 12b.

As shown in FIG. 4, the LEDs 42 are mounted by soldering on the periphery of the mounting area of the LEDs 41, that is, on both sides by a surface mounting method. The LED 42 is a surface-mount type, and a bare chip of the LED is packaged. The body is roughly formed of ceramics, the bare chip of the LED mounted on the body, and the bare chip of the LED is sealed. It is comprised from the translucent resin for molds, such as an epoxy-type resin and a silicone resin. Further, a pair of lead terminals connected to the bare chip of the LED protrude from the main body in the horizontal direction. On the substrate 17, the temperature detection means 8 is disposed around the mounting area of the LED 41.

The cooling means includes a fan motor 7 and a fan 71 attached to the fan motor 7. The fan motor 7 is an axial gap type brushless DC motor, and is attached to the back side of the heat sink 16. The fan motor 7 includes a coil 7a attached to the stator 72 and a rotor 73 to which a permanent magnet 7b is attached so as to face the coil 7a. A rotating shaft 7c is provided at the center of the rotor 73. It is fixed. One end side of the rotating shaft 7c is rotatably supported by a bearing portion protruding in the axial direction from the stator 72 side, and a fan 71 is attached to the other end side. The fan 71 is an axial fan, and when the fan 71 is rotated, outside air is forced to flow in from the intake port 11a of the main body case 11 and out of the exhaust port 11b.

  The cover member 13 is formed in a two-stage substantially cylindrical shape with an insulating material such as PBT resin. Therefore, when the cover member 13 is interposed between the main body case 11 and the base 14, insulation between the main body case 11 and the base 14 can be secured.

  The base 14 is of an E type, is electrically connected to the lighting device 1 by wiring, and has a cylindrical shell 14a with a screw thread that is screwed into a lamp socket of a lighting fixture (not shown), and the shell 14a. And an eyelet 14b provided via an insulating part.

In the housing space formed by the main body case 11, the cover member 13, and the base 14, there is a circuit board (not shown) on which the DC power source 2 constituting the lighting device 1 and the electronic components of the cooling means driving unit 6 are mounted. It is arranged.
The globe 15 is formed in a spherical shape from light-diffusing glass or synthetic resin, and has a shape that is continuous with the other end side of the main body case 11.

When the bulb-type LED lamp 10 configured as described above is energized by the lighting device 1, the LEDs 41 and the LEDs 42 are turned on all at once, and the light source unit 12 functions as a planar light source that emits white light. This light is emitted to the outside through the globe 15. In this case, the cooling means driving unit 6 is branched from the series circuit 5, since it is connected to both ends of the LEDs 42, the forward current I _F flowing through the series circuit 5 is shunted, so that the current flowing through the LEDs 42 is reduced .

Therefore, although the brightness of the LED 42 is slightly lowered, since the LED 42 is disposed around the mounting area of the LED 41, it is possible to reduce the occurrence of a sense of incongruity without causing a noticeable drop in brightness. . Further, since the LEDs 42 are mounted by the surface mounting method, the degree of freedom of arrangement is higher than that of the LEDs 41 mounted by the chip-on-board method, and can be disposed at a desired position. Furthermore, there is an advantage that the cooling means driving unit 6 can be easily branched.

The heat generated during the lighting of the LED 41 and the LED 42 is conducted mainly from the back surface side of the substrate 17 through the heat radiating plate 16 and the mounting rib 11 c and is transmitted to the main body case 11. At this time, when the temperature detecting means 8 on the substrate 17 detects a temperature rise above a certain level, electric power is supplied from the cooling means driving unit 6 to the fan motor 7, the fan motor 7 is driven, and the fan 71 is rotationally driven. As a result, outside air flows from the intake port 11a of the main body case 11 and acts on the back side of the heat radiating plate 16, and also acts on the inside of the main body case 11 and flows out from the exhaust port 11b.
Therefore, the heat generated from the LED 41 and the LED 42 is forcibly cooled and radiated to effectively suppress the temperature rise of the LED 41 and the LED 42.
In this case, the fan motor 7 is supplied with a stable DC voltage, so that the drive can be stabilized.

  As described above, according to this embodiment, the temperature rise of the LED 41 and the LED 42 can be effectively suppressed. Further, a stable voltage can be secured in the cooling means driving unit 6 without providing a special power source. Furthermore, since the LED 42 whose luminance is lowered is mounted by the surface mounting method, the degree of freedom of arrangement is high, and it can be arranged at a desired position.

  Next, an LED lighting device and a lighting device according to a second embodiment of the present invention will be described with reference to FIGS. 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, as shown in FIG. 5, the LEDs constituting the series circuit 5 are constituted by LEDs 42 mounted by a surface mounting method. Accordingly, the cooling means driving unit 6 is connected to branch from a desired connection point of the series circuit 5.

As shown in FIG. 6, the plurality of LEDs 42 are disposed substantially radially on the substrate 17. Like the first embodiment, the forward current I _F flowing through the series circuit 5 is shunted, the current flowing to LED42 connected to both ends of the cooling means driving section 6 is reduced brightness becomes possible to decrease the In this case, the discomfort can be reduced by arranging the LED 42 in the central part A or in the peripheral part B.

  In the present embodiment, when arranged in the central portion A, since the luminance of the central portion A is relatively large in the first place, even if the luminance of some of the LEDs connected to both ends of the cooling means driving unit 6 decreases. The influence on the overall brightness and light distribution can be reduced.

  As described above, according to the present embodiment, similarly to the first embodiment, the temperature rise of the LED 42 can be effectively suppressed, and the cooling means driving unit 6 is stably provided without providing a power source. Voltage can be secured. Furthermore, the uncomfortable feeling caused by the LED 42 whose luminance is reduced can be reduced.

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications can be made without departing from the spirit of the invention. For example, the DC power source includes a case where a commercial AC power source is received to generate a DC power source and a case where a battery is applied.

The fan motor may change the rotation speed based on the detection result of the temperature detection means. Furthermore, when the temperature detection means is not provided, the fan motor is always driven when the LED is energized.
The cooling means is not limited to a fan, and for example, a semiconductor element such as a Peltier element may be used.
In addition, the lighting device can be applied to a light source, a lighting fixture used indoors or outdoors, a display device, and the like.

DESCRIPTION OF SYMBOLS 1 ... LED lighting device, 2 ... DC power supply, 4, 41, 42 ... LED,
DESCRIPTION OF SYMBOLS 5 ... Series circuit, 6 ... Cooling means drive part, 7 ... Fan motor 10 ... Illuminating device (bulb-shaped LED lamp), 17 ... Substrate

Claims (3)

DC power supply;
A series circuit connected between the output terminals of the DC power source and connected to a plurality of LEDs;
A cooling means driving part that is branched from the series circuit and connected between at least one LED and cools heat generated by the LED;
LED lighting device characterized by comprising.   The plurality of LEDs are mounted on a substrate, and the plurality of LEDs include an LED in which an LED bare chip is directly mounted on the substrate and an LED in which the LED bare chip is packaged and surface-mounted, and the cooling 2. The LED lighting device according to claim 1, wherein the means driving unit is connected to both ends of at least one LED of the surface-mounted LED in which the bare chip of the LED is packaged. 3. The device body;
The LED lighting device according to claim 1 or 2, which is disposed in the device main body;
An illumination device comprising:

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