KR100879947B1 - Lighting apparatus using light emitting element - Google Patents

Abstract

A light apparatus using a light emitting device is provided to increase a lifespan of the light emitting device by maintaining a heating temperature properly. At least one penetration hole(22) or more are formed in a printed circuit board(20) of the planar type. A planar heat discharging member(30) is attached to the lower part of the printed circuit board and discharge the heat of the light emitting device. The light emitting device and the heat discharging member are adhered by a thermal conductive adhesive. A constant current circuit maintains the generation of heat of the emitting device to a constant temperature. The heat sink discharges the heat generated from the light emitting device. A driving unit drives the light emitting device to control difference between the consumed power value of the emitting device and the reference power value of the light emitting device within a predetermined value. A driving unit includes a control signal generator, and a constant voltage generator and a current controller. The controller generates the control signal for controlling the size of an output current. The constant voltage generator applies an operating voltage of the control signal generator. The current controller controls the size of the voltage based on the control signal.

Description

Lighting device using light emitting device {LIGHTING APPARATUS USING LIGHT EMITTING ELEMENT}

The present invention relates to a lighting apparatus using a light emitting element. More particularly, the present invention relates to a lighting apparatus using a plurality of light emitting elements, a printed circuit connecting the light emitting elements in series and in parallel, a heat sink for cooling the light emitting elements, and a light emitting element including a constant current circuit (HIC).

Lighting devices such as luminaires have been mainly used incandescent lamps and fluorescent lamps. Incandescent bulbs have the advantage of low cost, but there is a problem that generates more heat than the amount of light, fluorescent lamps have the advantage of high luminous efficiency of converting electrical energy into light energy, but it takes a long time to light and short lifespan have. Thus, in recent years, LEDs (Light Emitting Diodes) having high merit with low power and long lifespan are used.

1 is a view showing the configuration of the invention related to the light emitting diode lamp for AC power supply, Korean Utility Model Model No. 437242, LED is mounted on a metal LED substrate (PCB) manufactured using aluminum alloy, Heat sink is integrally formed on the surface to radiate heat generated during LED lighting operation.

By the way, the design is attached to a separate LED substrate of a metal material on the LED as shown in Figure 1, because it requires a separate printed circuit board for the operation of other electrical elements difficult to miniaturize and low heat dissipation efficiency And, there is a problem that the manufacturing cost of the metal PCB substrate takes a lot.

Also, in general, power LED of 1W or more and general LED have ± 5% of voltage deviation of each LED when allowable power is supplied, and when supplying constant voltage, current deviation is bigger than driving current, so A lot of heat is generated. However, by controlling and supplying the rated current of power LEDs and ordinary LEDs, it is possible to produce heat at the proper temperature and the optimal performance of power LEDs and general LEDs, and the lifetime of the LEDs is determined by the heating temperature. Table 1 below shows the lifetime corresponding to the junction temperature of the LED. As shown in Table 1, when the temperature of the junction of the LED exceeds 25 ℃ it can be seen that the life is drastically reduced.

TABLE 1

Temperature (℃) Life time (hours) Temperature (℃) Life time (hours) 25 234,000 85 29,500 30 191,000 90 25,700 35 157,000 95 22,300 40 129,000 100 19,500 45 107,000 105 17,100 50 90,000 110 15,100 55 75,000 115 13,300 60 64,000 120 11,700 65 54,000 125 10,500 70 46,000 130 9,300 75 39,600 140 7,500 80 34,000 150 6,000

[Manufacturer Presentation]

In addition, since each LED allowable current is less than 1A and its value is low, the LED reacts sensitively to minute changes in current, resulting in low luminous efficiency. There is a problem.

Accordingly, it is an object of the present invention to provide a lighting apparatus that can be miniaturized and thinned to reduce the manufacturing cost and lower the defective rate.

In addition, the present invention provides a lighting apparatus that can maintain the heat generation temperature of the light emitting device properly to extend the life of the light emitting device.

It is also an object of the present invention to provide a lighting device having a good luminous efficiency of the light emitting device.

In addition, it is an object of the present invention to provide a lighting device that can save the amount of power used by automatically adjusting the brightness of the light emitting device according to the illuminance.

It is also an object of the present invention to provide an illumination device having efficient diffusion and straightness of light.

The object of the present invention is a lighting device using a light emitting device, comprising: a printed circuit board having a planar shape in which at least one through hole is formed; And a planar heat dissipation member attached to the lower portion of the printed circuit board to contact the light emitting element through the through hole to dissipate the light emitting element, wherein the light emitting element and the heat dissipation member are bonded by a heat conductive adhesive. It is achieved by a lighting device characterized in that.

The heat sink may further include a heat sink attached to a lower portion of the heat radiating member to radiate heat generated from the light emitting device.

It may further include a light transmitting lens coupled to the light emitting device.

The light emitting device may include a light emitting diode (LED).

The LED may include a UVLED (UltraViolet Light Emitting Diode).

On the other hand, a lighting device using a light emitting device comprising: a printed circuit board formed with at least one through hole; A heat dissipation member having a flat plate shape in contact with the light emitting element through the through hole to radiate the light emitting element; A driving unit which drives the light emitting device such that a difference between the power value consumed by the light emitting device and the reference power value is within a preset value by adjusting the magnitude of the voltage so as to cancel a decrease in the resistance value of the light emitting device due to heat generation. The object is also achieved by a lighting device comprising a.

The difference between the consumed power value and the reference power value is preferably within 0.5% of the reference power value.

The driver may adjust the magnitude of the voltage by comparing the magnitude of the current applied to the light emitting device with the magnitude of the reference current.

The driving unit includes a control signal generator for generating a control signal for adjusting the magnitude of the output current; A constant voltage generator for applying an operating voltage of the control signal generator; It may include a current control unit for adjusting the magnitude of the voltage based on the control signal.

The driver may include a hybrid integrated circuit in which a plurality of different integrated circuits are combined.

The light emitting device and the heat dissipation member may be bonded by a heat transfer adhesive.

The heat sink may further include a heat sink attached to a lower portion of the heat radiating member to radiate heat generated from the light emitting device.

The apparatus may further include a temperature sensor for sensing a temperature of the lighting device, and the driving unit may adjust the magnitude of the voltage based on the temperature detected by the temperature sensor.

The apparatus may further include an illuminance sensor for sensing illuminance, and the driving unit may adjust the magnitude of the voltage according to the illuminance sensed by the illuminance sensor.

The light emitting devices are preferably arranged in a matrix form.

The light emitting device may include a light emitting diode (LED).

The LED may include a UVLED (UltraViolet Light Emitting Diode).

According to the lighting apparatus according to the present invention it is possible to reduce the size and thin film can be reduced manufacturing cost and lower the defective rate.

In addition, according to the lighting apparatus according to the present invention, the heat generation temperature of the light emitting device can be properly maintained to extend the life of the light emitting device.

In addition, according to the lighting apparatus according to the present invention, the luminous efficiency of the light emitting device is good.

In addition, according to the lighting apparatus according to the present invention, it is possible to automatically adjust the brightness of the light emitting device to save the amount of power used.

In addition, the lighting apparatus according to the present invention has efficient diffusion and straightness of light.

Hereinafter, a lighting apparatus using a light emitting device according to the present invention with reference to the accompanying drawings will be described in detail.

2 is a block diagram showing the configuration of a lighting apparatus according to a first embodiment of the present invention. As shown in FIG. 2, the lighting apparatus 100 according to the first embodiment of the present invention includes a light emitting element 10, a printed circuit board 20, and a heat dissipation member 30. The lighting device 100 according to the present invention is preferably implemented as a street lamp or a lamp used outdoors, but its use may be variously changed as necessary.

The light emitting element 10 irradiates light to a predetermined area. The light emitting device 10 according to the present invention may be implemented as a light emitting diode (LED). In addition, the light emitting device 10 according to the present invention may be implemented as a UVLED (UltraViolet Light Emitting Diode) that emits a wavelength that is harmless to plants and animals. The light emitting device 10 according to the present invention is an example of a LED having a constant size driving current and a constant size allowable voltage. At this time, according to the power consumption of the light emitting device 10 and the quantity of the light emitting device 10 can be determined the power consumption of the entire lighting device 100, such as 24W, 36W.

In addition, the light emitting device 10 according to the present invention may further be combined with a light transmitting lens (not shown) to improve the illuminance.

The printed circuit board 20 includes electrical elements necessary for the operation of the lighting apparatus 100, and a wiring (not shown) for supplying power to the light emitting element 10 is formed. In the printed circuit board 20 according to the present invention, at least one through hole 22 is formed such that the light emitting device 10 contacts the heat radiating member 30 to be described later.

On the other hand, the printed circuit board 20 according to the present invention, unlike the conventional printed circuit board of the conventional lighting device that requires a separate substrate for each LED is provided with only one printed circuit board in the lighting device itself and has a very thin thickness Have

Here, the through hole 22 is provided at a position corresponding to the position of the heat dissipation member 30 of the light emitting element 10, and when the plurality of light emitting elements 10 are provided, the number of the through holes 22 is light emission. It is formed corresponding to the number of elements 10, a thermally conductive adhesive is inserted into the formed through-holes 22 to bond the light emitting element 10 and the heat radiating member 30.

The heat radiating member 30 contacts the light emitting element 10 through the through hole 22 to radiate the light emitting element 10. The heat dissipation member 30 according to the present invention is implemented as a flat plate attached to the lower portion of the printed circuit board 20, it is preferable to be manufactured using a high thermal conductivity material such as aluminum.

In addition, the heat dissipation member 30 according to the present invention may further include a cooling fin (not shown) in order to increase the cooling efficiency, it is also possible to wrinkle the surface of the heat dissipation member 30.

Here, the light emitting element 10 and the heat dissipation member 30 are bonded by a heat transfer adhesive having a high thermal conductivity. The heat transfer adhesive may include an electrically insulating epoxy, silicone, grease, or the like. The lower the heat conduction resistance of the heat transfer adhesive, the better the heat generation of the light emitting device 10 is transferred to the heat radiation member or the heat sink. Experimental results show that heat transfer adhesives have a lower resistance value than tapes.

In the lighting apparatus 300 according to the first embodiment of the present invention, the light emitting device 10 contacts the heat radiating member 30 through the through hole 22 of the printed circuit board 20 without a separate LED substrate. As a result, the heat dissipation efficiency is high, miniaturization and thinning are possible, and the cost is low, compared to the conventional lighting apparatus 1 having an LED substrate implemented as a metal PCB.

On the other hand, Figure 3 is a cross-sectional view showing the configuration of the lighting apparatus 100 according to a second embodiment of the present invention.

In addition, the lighting apparatus 200 according to the second embodiment of the present invention further includes a driving unit 40 as compared to the lighting apparatus 100 according to the first embodiment of the present invention.

The driver 40 adjusts the magnitude of the voltage so that the lowering of the resistance value of the light emitting device 10 due to heat generation is offset so that the difference between the power value consumed by the light emitting device 10 and the reference power value is within a preset value. The light emitting element 10 is driven as much as possible.

Here, the reference power value may be determined by the user in consideration of the brightness and the life of the light emitting device 10. For example, when the allowable voltage is 3.3 V and the allowable current is 350 mA, the reference power value is 1.16 W, and may be defined differently according to the type of the light emitting device 10.

As described above, when the light emitting device 10 according to the present invention is implemented as an LED, when a current larger than the allowable current required for driving the LED is applied, a lot of heat is generated in the LED itself, and reacts sensitively to the surrounding temperature. Therefore, the driving unit 40 according to the present invention supplies a constant current to the light emitting device 10 and uses a PWM (Pulse Width Modulation) method to more efficiently use the power of a switch mode power supply (SMPS) used as a constant current power source. It is preferable to drive the light emitting element 10.

On the other hand, the driving unit 40 according to the present invention is preferably implemented as a hybrid integrated circuit (hereinafter referred to as "HIC") in which a plurality of different integrated circuits are combined. Integrated circuits may be classified into hybrid integrated circuits and monolithic integrated circuits, which may perform a variety of functions by electrically connecting a plurality of different circuit boards.

Hereinafter, the configuration of the driving unit 40 according to the present invention will be described in detail with reference to FIGS. 4 and 5.

4 is a block diagram showing the configuration of the drive unit 40 according to the present invention, Figure 5 is a detailed circuit diagram showing the configuration of the drive unit 40 according to the present invention. 4 and 5, the driving unit 40 according to the present invention includes a control signal generator 42, a constant voltage generator 44, and a current controller 46.

The control signal generator 42 generates a control signal for adjusting the magnitude of the output current to the light emitting element 10. The control signal generator 42 according to the present invention includes a DC-DC converter IC2 and a comparator IC3 and is connected to resistors and capacitors so that a bias voltage necessary for their operation is applied.

The constant voltage generator 44 applies an operating voltage of the control signal generator 42. The constant voltage generator 44 according to the present invention constantly generates the output voltage regardless of the variation of the input voltage. As an example, even if the input voltage of the SMPS is supplied to 11 ~ 14.5V to the constant voltage generator 44, the operating voltage of the control signal generator 42 is supplied with a constant magnitude.

When the DC-DC converter IC2 of the control signal generator 42 and the operating voltage of the comparator IC3 are applied by the constant voltage generator 44, the DC-DC converter IC2 generates a gate voltage and the comparator (IC3) compares the voltage across the resistor included in the current sensing unit connected in series with the FET with the reference voltage set across the variable resistor 110 to generate an amplified output for the difference voltage, and Q1 and Q2. The power is amplified and summed with the gate voltage generated by IC1 and applied to the FET gate. When the FET is turned on, a voltage having a predetermined magnitude is applied to the light emitting device 10 so that a current flows.

The amount of current is automatically controlled according to the set reference voltage. When the temperature of the light emitting device 10 rises and the resistance of the light emitting device 10 falls, the current value increases despite the same voltage, thereby increasing the power value. It is a major cause of the heat generation in (10). Such a phenomenon serves to continuously increase the current by dropping the resistance value of the light emitting device 10 in series, but even if the voltage is kept the same, this cannot be prevented.

Therefore, in the present invention, in order to prevent the heat generation of the light emitting device 10, the voltage value is automatically lowered to offset the portion of the resistor 110 in which the resistance value of the light emitting device 10 according to the light emission falls. It keeps a constant role. That is, when it is detected that the current increases by more than the value set by the resistor 110, the comparator IC3 amplifies it and controls the gate voltage in the direction of decreasing current. If it is detected that the current decreases below the set value, the gate voltage is controlled in a direction in which the current increases.

The current controller 46 controls the output current output to the light emitting element 10 based on the control signal generated by the control signal generator 42. The current controller 46 according to the present invention may be implemented as an FET to which a control signal is applied through the conductive wire, and the control signal generator 42 amplifies the voltage drop of the resistor connected in series with the current controller 46 and is referred to. Adjust the magnitude of the output current compared to the voltage.

In the current control unit 46, the reference current may vary according to the size of the variable resistor, and the current fluctuations may be serially generated due to the change in the voltage or the temperature rise due to the heat generation of the light emitting element 10 or the printed circuit board 20. This occurs at the connected resistor and senses and amplifies this change in current and regulates the current by controlling the gate voltage.

As a result, a voltage having a constant magnitude is supplied to the light emitting device 10 even when the output varies from 11 to 14.5V. The voltage supplied to the FET gate is set to a constant reference voltage, and the voltage supplied to the FET gate is always maintained even if the input voltage fluctuates. When the current increases or decreases based on the preset current value, the increment is detected and the value detected by the comparator IC3 is compared with the reference value by Q1, Q2, and TR, and the voltage is changed by increasing or decreasing the voltage at the Q2 emitter voltage. By controlling the gate voltage of Q3, the current flows at a constant current value.

By this operation, the HIC, which is the driving unit 40 according to the present invention, adjusts the magnitude of the current to the light emitting device 10 according to the voltage, current, etc. of the light emitting device 10 to consume power in the light emitting device 10. Can be reduced from ± 5% to ± 0.1%, thereby extending the life of the light emitting device 10 and increasing the luminous efficiency.

Hereinafter, a lighting apparatus according to a third embodiment of the present invention will be described in detail with reference to FIG. 6.

As shown in FIG. 6, the lighting device 200 according to the third embodiment of the present invention has a heat sink 50 and a temperature sensor compared to the lighting device 200 according to the second embodiment of the present invention. 60 and the illumination sensor 70 is further included. Each of these components is not necessarily provided at the same time and may optionally be included in the lighting device (300).

The heat sink 50 removes and cools heat generated during operation of the electrical elements included in the light emitting device 10 and the printed circuit board 20. The heat sink 50 according to the present invention may also be bonded by the heat dissipation member 30 and the heat conductive adhesive, and is preferably disposed at a position corresponding to the light emitting element 10 in the heat dissipation member 30.

Then, the temperature sensor 60 detects the temperature of the lighting device (300). The driving unit 40 adjusts the magnitude of the output current to the light emitting device 10 based on the temperature sensed by the temperature sensor 60. Thus, the lighting device 300 and the light emitting device 10 according to the present invention can maintain the appropriate temperature to extend the life of the light emitting device 10.

The illuminance sensor 70 detects illuminance around the illumination device 300. The driver 40 adjusts the magnitude of the output current according to the illuminance sensed by the illuminance sensor 70. For example, when there is a change in illuminance according to the movement of an object around the lighting device 300, the output current to the light emitting device 10 is greatly adjusted, and when there is no change in illuminance, the light is output to the light emitting device 10. The brightness of the lighting device 300 can be automatically adjusted by adjusting the output current size to be small. In addition, it is also possible to variously set the time for which the magnitude of the output current is maintained.

As mentioned above, the present invention has been described in detail through preferred embodiments, but the present invention is not limited thereto and may be variously implemented within the scope of the claims.

1 is a perspective view showing the configuration of a conventional lighting device,

2 is a perspective view showing the configuration of a lighting apparatus according to a first embodiment of the present invention,

3 is a cross-sectional view showing the configuration of a lighting apparatus according to a first embodiment of the present invention,

4 is a block diagram showing the configuration of a driving unit of the lighting apparatus according to the second embodiment of the present invention,

5 is a detailed circuit diagram illustrating a configuration of a driving unit of a lighting apparatus according to a second embodiment of the present invention.

6 is a block diagram showing the configuration of a lighting apparatus according to a third embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

10: light emitting device 20: printed circuit board

22: through hole 30: heat dissipation member

40: drive unit 42: control signal generator

44: constant voltage generator 46: current controller

50: Ambient light sensor 60: Temperature sensor

70: heat sink

Claims (17)

In a lighting device using a light emitting element, A printed circuit board having a planar shape in which at least one through hole is formed; A flat heat dissipation member attached to the lower portion of the printed circuit board in contact with the light emitting element through the through hole to radiate the light emitting element; The light emitting device and the heat dissipation member are bonded by a heat conductive adhesive, A heat sink attached to a lower portion of the heat radiating member to radiate heat generated from the light emitting device; A driving unit which drives the light emitting device such that a difference between the power value consumed by the light emitting device and the reference power value is within a preset value by adjusting the magnitude of the voltage so as to cancel a decrease in the resistance value of the light emitting device due to heat generation. Include, The driving unit includes a control signal generator for generating a control signal for adjusting the magnitude of the output current; A constant voltage generator for applying an operating voltage of the control signal generator; A current control unit for adjusting the magnitude of the voltage based on the control signal, The control signal generator includes a DC-DC converter IC2 and a comparator IC3, and is connected to resistors and capacitors so that a bias voltage necessary for the operation of the DC-DC converter and the comparator is applied thereto. The lighting device includes a temperature sensor for sensing the temperature of the lighting device, the driving unit adjusts the magnitude of the voltage based on the temperature detected by the temperature sensor, The illumination device includes an illumination sensor for sensing the illumination of the illumination device, the drive unit adjusts the magnitude of the voltage according to the illumination detected by the illumination sensor, The number of the through-holes lighting apparatus using a light emitting element, characterized in that formed corresponding to the number of the light emitting element. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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