CN203279308U

CN203279308U - Heat radiation type LED

Info

Publication number: CN203279308U
Application number: CN2013203111384U
Authority: CN
Inventors: 郑汉武; 林英辉
Original assignee: SHENZHEN SUIJING OPTOELECTRONICS TECHNOLOGY Co Ltd
Current assignee: Shenzhen Suijing Optoelectronics Co ltd
Priority date: 2013-05-31
Filing date: 2013-05-31
Publication date: 2013-11-06
Anticipated expiration: 2023-05-31

Abstract

The utility model provides a heat radiation type LED. The heat radiation type LED includes an LED illuminant and an LED driving circuit. The LED illuminant 1 and the LED driving circuit are disposed on a heat radiation substrate, which is provided with a plurality of heat radiation teeth at the lower surface. The length of each heat radiation tooth tends to decrease gradually from the center part to the two sides. The LED driving circuit includes: a boundary-type voltage-boosting power factor correction circuit, an active-clamping forward converter, and a high-low-limit constant current pulse width modulation driving light modulation circuit, which are connected in sequence. Luminescence characteristics of a light emitting diode (LED) are analyzed and current control is pointed out to be an optimal method for LED brightness modulation, taking a liquid crystal display (LCD) backlight module as an application background. An LED driving light modulation circuit with a three level structure is designed to obtain a higher luminescence efficiency and a better light modulation effect. It is shows by experiments that, by utilizing the designed LED driving circuit, a power factor of a system is increased, and drifts of LED main wavelength and color coordinate are reduced, so that luminance of the LED can be controlled effectively.

Description

A kind of heat dissipation LED

Technical field

The utility model relates to Display Technique field, LED-backlit source, more specifically, relates to a kind of heat dissipation LED equipment.

Background technology

At present traditional along with the progress of society and the development of technology, the display device that the characteristics such as the display device of LED (light-emittingdiode Light Emitting Diode) backlight is high with its reliability, long service life, adaptive capacity to environment is strong, cost performance is reasonable, use cost is low substitute traditional C CFL (cathode fluorescent tube Cold CathodeFluorescent Lamp) backlight gradually becomes rapidly the main product that large flat shows, is widely used in field of information display.The huge market demand impels liquid crystal panel manufacturer and national governments activity investments to set up the LED product line of a new generation, in this case, satisfies 55 inches and following liquid crystal panel 8.5 generation production line and builds like the mushrooms after rain.When various countries actively build 8.5 generation lines, with leading panel vendors such as Korea S's Samsung and Japanese Sharps, especially actively to higher line generation---can satisfy the 10 generations line investment that 65 inches and above HDTV (High-Definition Television), exhibition room display and billboard etc. are used.

The backing structure of 55 inches of traditional LED-backlit source and following display device generally has following two kinds:

1, downward back photo structure

Although on principle, LED array can be made infinity, but the existence due to air layer d, increased undoubtedly the thickness of whole display, because needing a large number of LED, this class display does support simultaneously, also increased from another point of view the energy consumption of display, be unfavorable for the reduction of display use cost, therefore this backing structure can't be made superhuge display device.

2, side entrance back structure

But because present LED brightness range is limit, the light guide plate width also must be restricted, and be positioned at the periphery of display due to this type of design LED luminescence unit, therefore be difficult to fundamentally improve the dynamic contrast of whole display, thereby make this backing structure can't make superhuge display device equally.

Thus, need a kind of LED of design can accomplish 65 inches even larger display devices as backlight, size, and if this display device satisfy the performance requirement of low cost, low energy consumption, high brightness and contrast.

The utility model content

For the problems referred to above, the utility model provides a kind of heat dissipation LED, it is characterized in that: described LED comprises the LED luminous element, LED drive circuit, described LED luminous element 1 and LED drive circuit 3 are positioned on heat-radiating substrate 4, have a plurality of radiation tooths 2 on the lower surface of heat-radiating substrate 4, the length of radiation tooth 2 is the trend of successively decreasing gradually from the centre to both sides.Described LED drive circuit comprises connection in turn: Boundary-Type step-up type power factor correction circuit, active clamping forward converter, the spacing constant current pulse-width modulation of height drive light adjusting circuit.

The technique scheme of utilizing the utility model to provide, display device can be accomplished infinity, ultra-thin in theory, and high according to the LED-backlit source display device brightness that the utility model is made, cost is low, dynamic contrast to, energy-conservation, the utility model adopts LED as backlight, go for 65 inches and above liquid crystal display, can be widely used in HDTV (High-Definition Television), show that Room display and billboard etc. need the display device of high definition, large-screen.

Description of drawings

Describe in more detail exemplary embodiment of the present utility model by the reference accompanying drawing, above and other aspect of the present utility model and advantage will become and more be readily clear of, in the accompanying drawings:

Fig. 1 is a kind of heat dissipation LED cross-sectional view of the present utility model.

Fig. 2 is a kind of heat dissipation LED driving circuit principle block diagram of the present utility model;

Fig. 3 is the circuit theory diagrams of Boundary-Type step-up type power factor correction circuit in a kind of heat dissipation LED drive circuit of the present utility model;

Fig. 4 is the circuit theory diagrams of active clamping forward converter in a kind of heat dissipation LED drive circuit of the present utility model;

Fig. 5 is the circuit theory diagrams that in a kind of heat dissipation LED drive circuit of the present utility model, the spacing constant current pulse-width modulation of height drives light adjusting circuit.

Embodiment

Hereinafter, now with reference to accompanying drawing, the utility model is described more fully, various embodiment shown in the drawings.Yet the utility model can be implemented in many different forms, and should not be interpreted as being confined to embodiment set forth herein.On the contrary, it will be thorough with completely providing these embodiment to make the disclosure, and scope of the present utility model is conveyed to those skilled in the art fully.

Hereinafter, exemplary embodiment of the present utility model is described with reference to the accompanying drawings in more detail.

With reference to accompanying drawing 1, Fig. 1 is a kind of heat dissipation LED cross-sectional view of the present utility model, described LED comprises LED luminous element 1, LED drive circuit 3, described LED luminous element 1 and LED drive circuit 3 are positioned on heat-radiating substrate 4, have a plurality of radiation tooths 2 on the lower surface of heat-radiating substrate 4, the length of radiation tooth 2 is the trend of successively decreasing gradually from the centre to both sides.Be as shown in a kind of heat dissipation LED driving circuit principle block diagram of the present utility model as Fig. 2, described LED drive circuit comprises in turn and to connect: Boundary-Type step-up type power factor correction circuit, active clamping forward converter, the spacing constant current pulse-width modulation of height drive light adjusting circuit.

Fig. 3 is the circuit theory diagrams of Boundary-Type step-up type power factor correction circuit in a kind of heat dissipation LED drive circuit of the present utility model; The electric main of input obtains and inputs the sine voltage signal of synchronizeing with the form of electric resistance partial pressure after the full bridge rectifier rectification; The feedback signal of output voltage through after error amplifier therewith sine wave signal multiply each other in multiplier, obtain sinusoidal reference signal, as the foundation of switch deadline; During switch conduction, inductive current rises, and current sense resistance is compared the inductor current signal that obtains with sinusoidal wave reference voltage, switch cut-off when inductor current signal equals sinusoidal reference signal; After the switch cut-off, inductance begins to release energy, and this moment, the auxiliary winding of inductance began the zero current detecting, and when inductive current reduced to zero, the zero current circuit for detecting triggered flip-flop, and switch is conducting again, starts next cycle.

Fig. 4 is the circuit theory diagrams of active clamping forward converter in a kind of heat dissipation LED drive circuit of the present utility model; In transformer one side, main switch, auxiliary switch, clamping capacitance, resonant inductance are arranged, formed by two diodes, outputting inductance, output capacitance, loads in Circuit Fault on Secondary Transformer.Wherein main switch and auxiliary switch are MOSFETS, and resonant inductance equals outer coilloading and transformer primary side leakage inductance sum.

Fig. 5 is the circuit theory diagrams that in a kind of heat dissipation LED drive circuit of the present utility model, the spacing constant current pulse-width modulation of height drives light adjusting circuit.This circuit drives the control integration circuit by main switch, current transformer, current-limiting resistance, fly-wheel diode, energy storage inductor, light emitting diode module, output capacitance, flow control resistance, PWM and light adjusting circuit forms.

The above is only embodiment of the present utility model, is not limited to the utility model.The utility model can have various suitable changes and variation.All any modifications of doing, be equal to replacement, improvement etc., within all should being included in protection range of the present utility model within spirit of the present utility model and principle.

Claims

1. heat dissipation LED is characterized in that:

Described LED comprises the LED luminous element, LED drive circuit, described LED luminous element and LED drive circuit are positioned on heat-radiating substrate, have a plurality of radiation tooths on the lower surface of heat-radiating substrate, the length of radiation tooth is the trend of successively decreasing gradually from the centre to both sides, described LED drive circuit comprises in turn and to connect: Boundary-Type step-up type power factor correction circuit, active clamping forward converter, the spacing constant current pulse-width modulation of height drive light adjusting circuit.

2. a kind of heat dissipation LED as claimed in claim 1 is characterized in that:

In described Boundary-Type step-up type power factor correction circuit, the electric main of input obtains and inputs the sine voltage signal of synchronizeing with the form of electric resistance partial pressure after the full bridge rectifier rectification; The feedback signal of output voltage through after error amplifier therewith sine wave signal multiply each other in multiplier, obtain sinusoidal reference signal, as the foundation of switch deadline; During switch conduction, inductive current rises, and current sense resistance is compared the inductor current signal that obtains with sinusoidal wave reference voltage, switch cut-off when inductor current signal equals sinusoidal reference signal; After the switch cut-off, inductance begins to release energy, and this moment, the auxiliary winding of inductance began the zero current detecting, and when inductive current reduced to zero, the zero current circuit for detecting triggered flip-flop, and switch is conducting again, starts next cycle.

3. a kind of heat dissipation LED as claimed in claim 1 is characterized in that:

Described active clamping forward converter structure is as follows: in transformer one side, main switch, auxiliary switch, clamping capacitance, resonant inductance are arranged, be comprised of two diodes, outputting inductance, output capacitance, loads in Circuit Fault on Secondary Transformer; Wherein main switch and auxiliary switch are MOSFETS, and resonant inductance equals outer coilloading and transformer primary side leakage inductance sum.

4. a kind of heat dissipation LED as described in claim 1-3 any one is characterized in that:

The spacing constant current pulse-width modulation of described height drives light adjusting circuit and is comprised of main switch, current transformer, current-limiting resistance, fly-wheel diode, energy storage inductor, light emitting diode module, output capacitance, flow control resistance, PWM driving control integration circuit and light adjusting circuit.