CN203375305U - LED for automobile meter - Google Patents

Abstract

The utility model provides an LED for an automobile meter. The LED comprises an LED light-emitting body, an LED driving circuit and a reflection cover, wherein the LED light-emitting body is located on the LED driving circuit, the LED driving circuit is located on the reflection cover, and an automobile instrument panel is illuminated through light of the LED light-emitting body. The LED driving circuit comprises a boundary type boosting power factor correction circuit, an active clamping forward converter and a high-low limiting constant current pulse width modulation driving dimming circuit, wherein the boundary type boosting power factor correction circuit, the active clamping positive converter and the high-low limiting constant current pulse width modulation driving dimming circuit are sequentially connected. An LCD backlight module is used as an application background, the light-emitting characteristics of the LED are analyzed, and the fact that current control is the best luminance control is indicated. In order to obtain high light-emitting efficiency and the good dimming effect, the LED driving dimming circuit of a three-stage structure is designed. Tests show that the designed LED driving circuit is used, therefore, the power factors of a system can be improved, drifting of the dominant wavelength and the color coordinates of the LED can be reduced, and the brightness of the LED is effectively controlled.

Description

Automobile instrument LED

Technical field

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

Background technology

At present traditional along with social progress 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, in field of information display, is widely used.The huge market demand impels liquid crystal panel manufacturer and national governments' activity investment to set up LED product line of new generation, in this case, meets 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 meet the 10 generations line investment of 65 inches and above application such as HDTV, exhibition room display and billboard.

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 current LED brightness range is limit, the LGP width also must be restricted, and because this type of designs the periphery that the LED luminescence unit is positioned at display, 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 meet 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 automobile instrument LED, it is characterized in that: described LED comprises LED illuminator 1, LED drive circuit 3, reflector 4, described LED illuminator 1 is positioned on LED drive circuit 3, and drive circuit 3 is positioned on reflector 4, the light illumination automobile instrument panel 2 of LED illuminator 1.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 pulsewidth modulation of height drive light adjusting circuit.

The technique scheme of utilizing the utility model to provide, display device can be accomplished to infinity, ultra-thin in theory, and the LED-backlit source display device brightness of manufacturing according to the utility model is high, 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 the display device that HDTV, showroom display and billboard etc. need fine definition, giant-screen.

The accompanying drawing explanation

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 automobile instrument of the present utility model LED cross-sectional view.

Fig. 2 is automobile instrument of the present utility model LED drive circuit functional-block diagram;

Fig. 3 is the circuit theory diagrams of automobile instrument of the present utility model with Boundary-Type step-up type power factor correction circuit in LED drive circuit;

Fig. 4 is the circuit theory diagrams of automobile instrument of the present utility model with active clamping forward converter in LED drive circuit;

Fig. 5 is that automobile instrument of the present utility model drives the circuit theory diagrams of light adjusting circuit with the spacing constant current pulsewidth modulation of height in LED drive circuit.

The specific 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 automobile instrument of the present utility model LED cross-sectional view, described LED comprises LED illuminator 1, LED drive circuit 3, reflector 4, described LED illuminator 1 is positioned on LED drive circuit 3, and drive circuit 3 is positioned on reflector 4, the light illumination automobile instrument panel 2 of LED illuminator 1.As Fig. 2 be automobile instrument of the present utility model with as shown in the LED drive circuit functional-block diagram, described LED drive circuit comprises and connecting in turn: Boundary-Type step-up type power factor correction circuit, active clamping forward converter, the spacing constant current pulsewidth modulation of height drive light adjusting circuit.

Fig. 3 is the circuit theory diagrams of automobile instrument of the present utility model with Boundary-Type step-up type power factor correction circuit in LED drive circuit; The electric main of input, after the full bridge rectifier rectification, obtains and inputs the sine voltage signal of synchronizeing with the form of electric resistance partial pressure; The feedback signal of output voltage after error amplifier therewith sine wave signal in multiplier, multiply each other, 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 of acquisition with sinusoidal wave reference voltage, switch cut-off when inductor current signal equals sinusoidal reference signal; After the switch cut-off, inductance starts to release energy, and now the auxiliary winding of inductance starts the zero current detecting, and when inductive current reduces to zero, the zero current circuit for detecting triggers flip-flop, and switch is conducting again, starts next cycle.

Fig. 4 is the circuit theory diagrams of automobile instrument of the present utility model with active clamping forward converter in LED drive circuit; 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 that automobile instrument of the present utility model drives the circuit theory diagrams of light adjusting circuit with the spacing constant current pulsewidth modulation of height in LED drive circuit.This circuit drives control integration circuit and light adjusting circuit to form by main switch, current transformer, current-limiting resistance, fly-wheel diode, energy storage inductor, light emitting diode module, output capacitance, flow control resistance, PWM.

The foregoing is only embodiment of the present utility model, be 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 domain of the present utility model within spirit of the present utility model and principle.

Claims (3)

1. automobile instrument LED is characterized in that:

Described LED comprises the LED illuminator, LED drive circuit, reflector, described LED luminous body position is on LED drive circuit, drive circuit is positioned on reflector, the light illumination automobile instrument panel of LED illuminator, 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 pulsewidth modulation of height drive light adjusting circuit.

2. automobile instrument 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.

3. automobile instrument LED as described as claim 1-2 any one is characterized in that:

The spacing constant current pulsewidth modulation of described height drives light adjusting circuit to drive control integration circuit and light adjusting circuit to form by main switch, current transformer, current-limiting resistance, fly-wheel diode, energy storage inductor, light emitting diode module, output capacitance, flow control resistance, PWM.

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