KR101357861B1 - Led lighting apparatus - Google Patents

Abstract

An LED lighting device is disclosed. LED lighting device according to the present invention is a base, an LED chip mounted on one side of the base, the forced circulation portion and the base, LED chip and forced circulation portion installed on the opposite side mounted on the LED chip of the base to radiate air toward the base It includes a housing surrounding the base, the LED chip and the forced circulation to block the outside air, inside the housing through the forced convection to transfer the heat generated from the LED chip to the surface of the housing, the natural convection is induced outside the surface of the housing Cool the heat on the housing surface.

Description

LED lighting device {LED LIGHTING APPARATUS}

The present invention relates to an LED lighting device.

A light emitting diode (LED) is a semiconductor device that emits light when a voltage is applied in a forward direction. The principle of light emission is electroluminescence, which injects electrons and holes by an electric field and emits light upon recombination.

Compared to other lighting devices such as fluorescent lamps, halogen lamps and incandescent lamps, the LED lighting device consumes low power, has a fast response speed, and is environmentally friendly and has high efficiency. The trend is active.

However, LEDs need to be provided with heat dissipation means to generate a lot of heat when high power is required, and to dissipate this heat to the outside of the LED lighting device. The disadvantage is that performance is greatly reduced.

As a heat dissipation structure of an LED lighting device that is generally applied, a structure in which heat generated from an LED is emitted to the outside through heat conduction using a heat conduction medium having a large heat dissipation area such as a heat sink.

However, in the heat dissipation structure through such heat conduction, heat resistance is generated in the heat conduction medium. Thermal resistance is a property that interferes with the thermal conductivity. In the case of a uniform object, the thermal resistance is inversely related to the thermal conductivity, but in practice, the thermal resistance often means a property of an interface or a contact surface.

Therefore, as the heat conduction medium in the heat conduction process increases, the overall heat resistance increases, which may lower the heat radiation efficiency of the LED lighting device.

Meanwhile, as shown in FIG. 1, the heat dissipation structure of the conventional LED lighting device uses a heat dissipation structure that emits heat generated from the LED to the outside through air circulation inside and outside the LED lighting device, in order to compensate for heat dissipation through heat conduction. Doing.

By the way, in the case of the heat dissipation structure through the air circulation inside and outside the LED lighting device may be higher heat dissipation efficiency than the heat dissipation structure only through the heat conduction, foreign matters such as dust contained in the outside air is introduced into the LED lighting device, Its life and performance may be impaired.

Republic of Korea Patent Publication No. 10-1070523 (2011.10.05.)

The present invention can block the inside of the LED lighting device to the outside air to prevent foreign substances such as dust contained in the outside into the LED lighting device, and at the same time smoothly heat generated from the LED through the convection heat transfer It is to provide an LED lighting device that can be cooled.

According to an aspect of the present invention, the base, the LED chip mounted on one surface of the base, the forced circulation portion and the base, LED chip and the forced circulation portion which is installed on the opposite side on which the LED chip of the base is mounted to emit air in the base direction It includes a housing surrounding the base, the LED chip and the forced circulation to block the outside air, inside the housing through the forced convection to transfer the heat generated from the LED chip to the surface of the housing, the natural convection is induced outside the surface of the housing An LED lighting device is provided which cools the heat of the housing surface.

Here, the LED lighting device further includes a cover that surrounds the base, the LED chip and the forced circulation and allows air circulation between the inside and the outside, the housing surrounds the cover so that the cover is blocked from outside air, and the forced convection inside the housing is the air between the inside and outside of the cover. This can be done through circulation.

The forced circulation may comprise a fan.

The forced circulation may comprise a piezo actuator.

The LED lighting device may further include a guide part for guiding air circulated in the housing such that air emitted from the forced circulation part is re-absorbed into the forced circulation part along the outer portion of the housing.

The LED lighting apparatus may further include a power supply unit installed in the housing to supply power to the LED chip.

According to an embodiment of the present invention, the interior of the LED lighting device is blocked from the outside by the housing to prevent foreign matters such as dust contained in the outside into the interior of the LED lighting device, forced convection in the interior of the housing Through heat transfer from the LED chip to the surface of the housing and natural convection is induced outside the surface of the housing to cool the heat of the housing surface, the heat generated from the LED chip can be smoothly cooled through the convection heat transfer.

1 is a view showing a heat dissipation structure of a conventional LED lighting device.
2 is a view showing an LED lighting apparatus according to a first embodiment of the present invention.
3 is a view showing the relationship between the area A and the surface temperature T2 at which convective heat transfer takes place in the LED lighting apparatus according to the first embodiment of the present invention.
4 is a view showing an LED lighting apparatus according to a second embodiment of the present invention.
5 is a view showing an LED lighting apparatus according to a third embodiment of the present invention.
6 and 7 are views showing in detail the piezoelectric actuator in the LED lighting apparatus according to the third embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, an embodiment of the LED lighting apparatus according to the present invention will be described in detail with reference to the accompanying drawings, in the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and duplicated thereto The description will be omitted.

2 is a view showing an LED lighting apparatus according to a first embodiment of the present invention. 3 is a view showing a relationship between the area A and the surface temperature T1 where convective heat transfer takes place in the LED lighting apparatus according to the first embodiment of the present invention.

As shown in FIG. 2, the LED lighting apparatus 1000 according to the first embodiment of the present invention includes a base 100, an LED chip 200, a forced circulation unit 300, and a housing 400. The guide unit 600 and the power supply 700 may further include.

In this case, the heat generated from the LED chip 200 is transferred to the surface of the housing 400 through the forced convection inside the housing 400, and natural convection is induced outside the surface of the housing 400 so that the housing 400 is introduced. ) It can cool the surface heat.

The base 100 is a portion in which the LED chip 200 is mounted on one surface, and air is emitted by the forced circulation part 300 on the opposite surface. In this case, the base 100 may be formed of a printed circuit board (PCB) formed with a printed circuit pattern, which is a passage for transmitting an electrical signal, and the LED chip 200 may be formed based on the printed circuit pattern. Can be implemented in various forms.

In this case, the base 100 may be made of a material having excellent light transmittance so as to transmit light emitted from the LED chip 200, and may be made of a material having excellent insulation.

The LED chip 200 is mounted on one surface of the base 100 to emit light using electrical energy. The base 100 may be configured as an LED package mounted and packaged on a package substrate as needed. The number and arrangement of the LED chips 200 mounted on may be variously selected as necessary.

The forced circulation part 300 is installed on the opposite side on which the LED chip 200 of the base 100 is mounted and emits air in the direction of the base 100, and may cause forced convection inside the housing 400. have.

Here, the forced circulation unit 300 may include a fan 310 to suck or divert air through a wing or the like. Specifically, the air is discharged from one side of the fan 310 toward the base 100, and the released air circulates inside the housing 400, and forced convection is carried out through the process of being sucked to the other side of the fan 310. Can happen.

In addition, the forced circulation unit 300 may include a piezoelectric actuator (320 of FIG. 5). The piezoelectric actuator 320 (FIG. 5) will be described in detail later.

Meanwhile, in the present exemplary embodiment, the forced circulation unit 300 discloses a configuration including a fan 310 or a piezoelectric actuator (320 of FIG. 5), but is not necessarily limited thereto, and is installed inside the housing 400. 400 may include any device capable of causing forced convection through the process of inhaling and releasing air therein.

The housing 400 is a part surrounding the base 100, the LED chip 200, and the forced circulation part 300 to block the base 100, the LED chip 200, and the forced circulation part 300 from outside air, and the LED By blocking the inside of the lighting device 1000 with the outside air, foreign matters such as dust included in the outside air may be prevented from entering the inside of the LED lighting device 1000.

In this case, the housing 400 may be made of a material having sufficient strength to protect the base 100, the LED chip 200, and the forced circulation part 300, and may include all or part of the housing 400. May be made of a material that can transmit light emitted from the LED chip 200. In addition, the housing 400 may be made of a material capable of diffusing light emitted from the LED chip 200, including a diffusion lens.

The guide part 600 is a part for guiding air circulated in the housing 400 such that the air emanated from the forced circulation part 300 is re-sucked into the forced circulation part 300 along the outer portion of the housing 400. The heat generated from the LED chip 200 is to facilitate the forced convection to the surface of the housing 400 more smoothly.

In this case, the guide part 600 may be made of a material having excellent light transmittance so as to transmit light emitted from the LED chip 200.

Meanwhile, in FIG. 2, the guide part 600 surrounds the LED chip 200 and shows a radial shape. However, the guide part 600 is not limited thereto and may guide air circulated in the housing 400 as necessary. It can be applied in various shapes.

The power supply 700 is installed in the housing 400 to supply power to the LED chip 200, and may be applied to the LED lighting device 1000 such as a switching mode power supply (SMPS). It may include a power supply.

The LED lighting apparatus 1000 according to the present exemplary embodiment may smoothly cool the heat generated from the LED chip 200 through the convection heat transfer. Hereinafter, a process of cooling the heat generated from the LED chip 200 by the LED lighting apparatus 1000 according to the present embodiment will be described in more detail with reference to Equation 1, Table 1, and FIG. 3.

Representative methods for heat dissipation in the LED lighting apparatus 1000 include a method of dissipating heat generated from the LED to the outside through heat conduction using a heat conducting medium having a large heat dissipation area such as a heat sink and a fluid ( Air may be released to the outside through convection of air).

In the case of the method through the heat conduction, it is necessary to minimize the number of the heat conduction medium in the heat conduction process in order to increase the heat radiation efficiency by reducing the heat resistance as described above. To this end, it is possible to assume the LED lighting device 1000 that has simplified the heat dissipation structure by removing the heat sink.

In this case, heat generated from the LED chip 200 is conducted to the base 100, but considering the heat dissipation area can be said that the heat dissipation effect through this is insignificant. Therefore, it is necessary to actively utilize a method of dissipating heat to the outside by using convection of a fluid (air) as a heat dissipation method of the LED lighting apparatus 1000 from which the heat sink is removed.

On the other hand, by using the convection of the fluid (air) to emit heat to the outside air to circulate the air inside and outside the LED lighting device 1000 to directly discharge the heat generated from the LED chip 200 to the outside air Although the method may be considered, such a method also has a problem in that foreign matters such as dust included in the outside air are introduced into the LED lighting apparatus 1000 and the lifespan and performance of the LED lighting apparatus 1000 may be reduced. .

Accordingly, the present invention is to overcome the above problems, the LED lighting device 1000 that can emit heat to the outside by using the convection of the fluid (air) while blocking the outside air through the housing 400 to provide.

Equation 1

Q = h · A · (T2-T1)

Q: Calories

h: convective heat transfer coefficient

A: Area where convective heat transfer takes place

T1: fluid temperature

T2: surface temperature

Equation 1 is Newton's law of cooling: heat in convective heat transfer (Q), convective heat transfer coefficient (h), area where convective heat transfer occurs (A), surface temperature (T2), and fluid The relationship between temperature T1 is prescribed | regulated.

Here, two methods may be considered in order to increase the amount of heat Q transmitted convection. The first is to increase the convective heat transfer coefficient h, for example to increase the velocity of the fluid via forced circulation means. The second is to increase the area A in which convective heat transfer occurs.

In the case of the LED lighting apparatus 1000 according to the present exemplary embodiment, forced convection of air occurs by the forced circulation unit 300 inside the housing 400, and in this process, heat generated by the LED chip 200 is generated. It may be delivered to the surface of the housing 400.

Here, as the power consumption W of the LED chip 200 increases, the amount of heat Q to be transmitted to the surface of the housing 400 also increases through forced convective heat transfer. In this case, the LED lighting apparatus 1000 according to the present exemplary embodiment increases the speed of forced air convection in the housing 400 by using the forced circulation part 300 to thereby generate heat generated by the LED chip 200. It can be smoothly transferred to the surface of the housing 400.

Meanwhile, natural convection of air is induced outside the surface of the housing 400 according to the temperature difference between the surface of the housing 400 and the outside air, and in this process, heat of the surface of the housing 400 may be cooled.

Here too, as the power consumption W of the LED chip 200 increases, the amount of heat Q to be cooled through natural convective transmission also increases. In this case, the LED lighting apparatus 1000 according to the present embodiment increases the area A where natural convection heat transfer occurs by appropriately selecting the surface area of the housing 400, thereby smoothly cooling the heat on the surface of the housing 400. You can.

Area (A) Surface temperature (T2) 420㎡ 83.5 DEG C 540㎡ 70.6 ℃ 820㎡ 55.4 ℃ 1,000 mm2 50.1 ℃ 1,500㎡ 40.6 ℃ 2,000 mm2 35.5 DEG C

Table 1 is an experimental result of measuring the relationship between the area (A) and the surface temperature (T2) in which convective heat transfer occurs in the LED lighting apparatus 1000 according to the present embodiment. And this result is shown in FIG.

In this case, the LED chip 200 used a power consumption (W) of 125W, the experiment was performed with the temperature of the outside air of the fluid temperature (T1) is set to 24 ℃.

As shown in Table 1 and FIG. 3, it can be seen that the surface temperature T2 of the housing 400 decreases as the area A in which convective heat transfer occurs increases.

Based on the experimental results, since the LED lighting apparatus 1000 generally does not change the power consumption (W) of the LED 200 applied at the time of initial manufacture, it is possible to properly select the surface area of the housing 400. It can be seen that the surface temperature T2 of the housing 400 can be adjusted within an acceptable range.

In particular, considering that the heat generated from the LED chip 200 is about 150 ° C., even if the surface area of the housing 400 in which convective heat transfer occurs is about 420 mm 2, the life and performance of the LED lighting device 1000 are problematic. It can be seen that there is no.

4 is a view showing an LED lighting apparatus according to a second embodiment of the present invention.

As shown in FIG. 4, the LED lighting device 2000 according to the second embodiment of the present invention may further include a cover 500.

In this case, the housing 400 surrounds the cover 500 such that the cover 500 is blocked from outside air, and forced convection inside the housing 400 may be achieved through air circulation between the inside and the outside of the cover 500.

Cover 500 is a portion surrounding the base 100, the LED chip 200 and the forced circulation unit 300 and the air circulation between the inside and the outside, may be to primarily protect the interior of the LED lighting device (1000). . In addition, the cover 500 is circulated in the housing 400 such that the air discharged from the forced circulation unit 300, like the guide unit 600, is re-suctioned into the forced circulation unit 300 along the outer portion of the housing 400. It may also serve to guide the air being released.

In this case, the cover 500 may be made of a material having sufficient strength to protect the base 100, the LED chip 200, and the forced circulation part 300, and may cover all or part of the cover 500. May be made of a material that can transmit light emitted from the LED chip 200. In addition, the cover 500 may be formed of a material capable of diffusing light emitted from the LED chip 200, including a diffusion lens.

Meanwhile, FIG. 4 illustrates an example in which a hole for air circulation is formed in the cover 500, but is not necessarily limited thereto, and may be applied in various shapes to enable air circulation between the inside and the outside of the cover 500 as necessary. Can be.

In the LED lighting device 2000 according to the present embodiment, the housing 400 may be separated into at least two parts, and a coupling part 410 may be formed to allow the respective parts to be combined to be hermetically sealed. In addition, a socket 420 connected to the power supply unit 700 may be formed in any one portion of the housing 400.

The LED lighting apparatus 2000 according to the second exemplary embodiment of the present invention has the same configuration as the LED lighting apparatus 1000 according to the first exemplary embodiment of the present invention except for the configuration further including the cover 500 described above. Therefore, detailed description thereof will be omitted.

5 is a view showing an LED lighting apparatus according to a third embodiment of the present invention. 6 and 7 are diagrams showing in detail a piezoelectric actuator in the LED lighting apparatus according to the third embodiment of the present invention.

5 to 7, in the LED lighting apparatus 3000 according to the third exemplary embodiment of the present invention, the forced circulation part 300 may include a piezoelectric actuator 320.

The piezoelectric actuator 320 uses piezoelectric characteristics of a ceramic material, and is an electric actuator that outputs displacement or generating force using electricity as input energy. That is, when the electric field is applied to the piezoelectric film 321 constituting the piezoelectric actuator 320, it can be said to use the property of stretching or contracting.

Specifically, in the piezoelectric film 321, positive and negative ions are elastically connected to form a crystal lattice. When an electric field is applied, positive ions are pulled in the electric field direction and negative ions are reversed. As such, when the electric field is applied to the piezoelectric film 321, stress is generated to deform the crystal lattice.

In other words, in the initial state of the piezoelectric film 321 which is a polycrystalline body, each grain interior is generally divided into several polarizations having different polarization directions. In this state, the polarization to the whole cancels out and is not expressed externally. At this time, when the electric field is applied to the piezoelectric film 321, the polarization direction inside the crystal is polarized along the electric field direction, and at the same time, the length of the crystal grains increases in the electric field direction. When the electric field is removed, the entire state is almost polarized without returning to the initial state.

Displacement due to polarization is called residual deflection, and a series of treatments is called polarization treatment, as mentioned above. After the polarization treatment, each crystal is added or removed in the same direction to reciprocate the stretched and reduced states, and the whole piezoelectric film 321 is moved.

The piezoelectric actuator 320 shown in FIG. 6 is a curved displacement type, and when an electric field is applied to the piezoelectric film 321, the piezoelectric film 321 vibrates in a curved shape through the above-described process. At this time, the flow of air is generated according to the vibration of the piezoelectric film 321 and the air flow rate can be increased as the air exits through the fluid acceleration pipe 323. As a result, the forced circulation part 300 can emit air toward the base 100.

The piezoelectric actuator 320 illustrated in FIG. 7 is stacked, and when the plurality of piezoelectric films 321 are stacked and an electric field is applied, the volume of the piezoelectric films 321 stacked through the above-described process increases. At this time, the flow of air is generated in accordance with the volume change of the piezoelectric film 321 and the air flow rate can be increased as the air exits through the fluid acceleration pipe 323. As a result, the forced circulation part 300 can emit air toward the base 100.

The LED lighting apparatus 3000 according to the third embodiment of the present invention is the LED lighting apparatus according to the first embodiment of the present invention except for the configuration in which the above-described forced circulation unit 300 includes the piezoelectric actuator 320. Since the configuration is the same as 1000, a detailed description thereof will be omitted. All.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit of the invention as set forth in the appended claims. The present invention can be variously modified and changed by those skilled in the art, and it is also within the scope of the present invention.

100: Base
200: LED chip
300: forced circulation
310: fan
320: piezo actuator
321: piezoelectric film
323: fluid acceleration tube
400: housing
410: coupling part
420: socket
500: cover
600: guide part
700: power supply
1000, 2000, 3000: LED lighting device

Claims (6)

Base;
An LED chip mounted on one surface of the base;
A forced circulation unit installed at an opposite side on which the LED chip of the base is mounted, and for discharging air toward the base;
A cover for enclosing the base, the LED chip, and the forced circulation part and allowing air circulation between the inside and the outside; And
A housing that covers the cover to block the outside air, and is separated into at least two parts, and a housing having a coupling part formed therein so that the respective parts are combined and hermetically sealed;
/ RTI >
Inside the housing, the heat generated from the LED chip is transferred to the surface of the housing through forced convection between the inside and the outside of the cover, and natural convection is induced outside the surface of the housing to cool the heat on the surface of the housing. LED lighting device.
delete The method of claim 1,
The forced circulation unit comprises a fan (fan).
The method of claim 1,
The forced circulation portion LED lighting device, characterized in that it comprises a piezo actuator.
The method of claim 1,
A guide unit for guiding air circulated in the housing such that the air emanated from the forced circulation part is re-sucked into the forced circulation part along an outer portion of the housing;
LED lighting device further comprising.
The method of claim 5,
A power supply unit installed in the housing to supply power to the LED chip;
LED lighting device further comprising.

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