CN102612861B - The lighting control method of light emitting diode drive device and light-emitting diode - Google Patents

Abstract

The invention provides the lighting control method of a kind of light emitting diode drive device and light-emitting diode, while can power-efficient being maintained, improve LED utilization ratio and power factor.This light emitting diode drive device possesses: rectification circuit 2, and it can be connected with AC power, for the pulsating voltage after obtaining the ac voltage rectifier of this AC power; A LED block 11 that be connected in series with the outlet side of described rectification circuit 2, that be made up of multiple light-emitting diode, the 2nd LED block 12 be made up of multiple light-emitting diode, the 3rd LED block 13 be made up of multiple light-emitting diode; First switch unit, it is based on the turn on angle of a described LED block 11, switches the ON/OFF making the first bypass path BP1 of described 2nd LED block 12 bypass; With the second switch unit, it, based on the turn on angle of a described LED block 11 and described 2nd LED block 12, switches the ON/OFF of the second bypass path BP2 for making described 3rd LED block 13 bypass.

Description

The lighting control method of light emitting diode drive device and light-emitting diode

Technical field

The present invention relates to and the drive circuit of driving and the lighting control method of light-emitting diode are lighted to light-emitting diode, particularly use AC power to carry out the lighting control method of light emitting diode drive device and the light-emitting diode driven.

Background technology

In recent years, as illuminating light source, the light-emitting diode that can carry out driving with low power consumption compared with incandescent lamp bulb or fluorescent lamp is (hereinafter also referred to " LED ".) attracted attention.The advantage of LED is: small-sized and resistance to impact is strong, need not worry that lamp body breaks.

As the power supply of this lighting apparatus, it is desirable to adopt the interchange of domestic power supply etc. as power supply.On the other hand, LED is DC driven element, only luminous under the electric current of forward.In addition, the forward voltage Vf as the LED of the current most employing of lighting use is about 3.5V.LED has following characteristic: if do not reach Vf, not luminous, if contrary to Vf, flows through excessive electric current.Therefore, can say that for LED the driving based on direct current is more suitable.

In order to tackle this contrary condition, propose the drive circuit of the LED of various employing AC power.Such as, in the drive circuit shown in Fig. 8, carry out full-wave rectification by bridge circuit 72 pairs of AC power 71, after smoothing by smmothing capacitor 73, carry out driving LED group 75 with the drive circuit 74 of constant current circuit or switching power circuit etc.In the circuit, owing to there being the characteristic requirements of high withstand voltage, high capacitance to level and smooth smmothing capacitor 73, therefore need the element that aluminium electrolytic capacitor etc. is large-scale.In addition, there is life-span short problem in general electrolytic capacitor when temperature is higher around.Further, there is the problem of the performance degradation under maximization and high temperature too for the coil used in Switching Power Supply.On the other hand, in switching power circuit, due to speed-sensitive switch big current, easily produce noise, therefore also need noise counter plan.Like this, in existing drive circuit, there are the following problems: need the configuration space guaranteeing the element used in the drive circuit that should be suitable for miniaturized LED, needing the structure for reducing temperature impact, also needing noise counter plan.

Following method is proposed for this problem, in order to improve the compatibility between LED, the smoothing of the voltage waveform after not carrying out by bridge circuit rectification, but drive with constant current circuit etc.This circuit example has been shown in Fig. 9.Drive circuit shown in this figure is identical with Fig. 8, after carrying out full-wave rectification by bridge circuit 82 pairs of AC power 81, and not smoothingization, but carry out driving LED group 85 by the constant current circuit 84 be made up of transistor and resistance.Constant current circuit 84 is made up of feedback resistance 86, current detecting transistor 87, current control transistor 88, current sense resistor 89.Because this circuit is made up of semiconductor element, therefore can say that with the operating temperature range between identical semiconductor element and LED be common, be suitable for miniaturization.

But, in not smoothingization and driving LED time, its voltage waveform becomes as shown in Figure 10, its magnitude of voltage cyclic variation and non-constant value.On the other hand, because each LED is one another in series connection as shown in Figure 9, as long as therefore apply voltage not more than the aggregate value of the forward voltage Vf of LED, LED would not light.Therefore, in the voltage waveform of time variations this shown in Figure 10, there is the limited time that LED lights, thus the problem that the utilization ratio of LED declines.At this, the utilization ratio of so-called LED is represented by (the effective power consumption of LED)/(LED power consumption when DC rated current drives).

Especially, in order to protect LED to insert in the circuit of current-limiting resistance with joining with LED strip, relative to mains fluctuations, the electric power of LED also has very great fluctuation process, sometimes also can more than LED rated current, and therefore, needing in advance must be less by current settings.Therefore, generally form constant current circuit in this case to drive.If be described in detail for problem now, such as the 100V of the source power supply of Japan is effective value, and the maximum voltage after full-wave rectification is 141V.LED is being connected to this power supply, when carrying out driving with constant current circuit, if only connect the LED of a Vf=3.5V, and constant current circuit is adopted to drive, then in the scope of supply voltage more than 3.5V, LED is in ON, and LED utilization ratio uprises.But in the voltage waveform of Figure 11 as shown in shade, the major part of electric power is consumed as heat, and is not used to luminescence, its result power-efficient reduces greatly.

On the other hand, also consider the number of connection increasing LED, multiple LED strip is joined and connects, thus the aggregate value of forward voltage Vf is close to 141V.Now, if want to guarantee that power-efficient is about 90%, then the aggregate value of Vf is needed to be about 120V.But in the scope of supply voltage more than 120V, LED just becomes ON in this design, and can not light at its following LED, and its result is only lighted in fig. 11 in the scope shown in dotted line, is about 35% as ON duty ratio.Therefore, LED utilization ratio is also about 35%, and power factor is about 77%.Like this, if reduce Vf to improve LED utilization ratio, then can be increased by the idle work of heat exhaustion, if contrary improvement power-efficient and improve Vf, then the ON duty ratio of LED shortens, and LED utilization ratio worsens, and there is the problem of this contradiction.

Moreover, propose the method (patent documentation 1) switching LED according to the mode changing the aggregate value of Vf according to the magnitude of voltage of change.In the method, as shown in the circuit diagram of Figure 12, the LED that plural serial stage connects is divided into block 61,62,63,64,65,66, switched the connection of LED block 61 ~ 66 by the switching controlling part 67 that is made up of microcomputer according to the magnitude of voltage of the input voltage of rectified waveform, thus periodically change the aggregate value of Vf.Its result, the voltage waveform as shown in the sequential chart of Figure 13, can light LED with multiple rectangular wave relative to rectified waveform, compared with the ON duty ratio under therefore this with Figure 11 only single rectangular wave, can improve the utilization ratio of LED.But, in the method, based on detecting the magnitude of voltage of input waveform and the result that obtains, using microcomputer to switch each LED block side by side, high-precision control can be carried out, but antimetrical circuit forms and becomes expensive, cannot towards the lighting device of cheapness.

As shown in the circuit diagram of Figure 14, microcomputer is not used and by Zener diode and resistance to detect the structure of voltage further, also proposed.Circuit shown in this figure is based on by the magnitude of voltage after Zener diode 94 and resistance 95 dividing potential drop, the connection of LED block 91,92,93 is switched according to the magnitude of voltage of the input voltage of rectified waveform, periodically change the aggregate value of Vf, its result, as shown in the voltage waveform of Figure 15, can light LED with multiple rectangular wave relative to rectified waveform.Circuit than Figure 12 is formed, and the advantage of this structure is to be formed in the mode of cheapness.

But, in above-mentioned any means, due to be according to rectification after input voltage switch the structure lighted between LED block, therefore need correctly to make this switched voltage value consistent with the Vf value (when setting electric current) of LED block at different levels.But generally can characteristic deviation be there is in LED element, Vf and temperature characterisitic different for each element, therefore in reality, this adjustment is correctly very difficult.Particularly as shown in figure 13, because each LED block needs multiple LED element to be one another in series connection, the therefore result that is added step by step of the deviation of the Vf of each element, the deviation of the Vf magnitude of voltage of LED block entirety can become larger.On the other hand, also consider the LED element only used to suppress deviation to be selected in advance, but the cost increase of LED element in this case, and rate of finished products also worsens.In lighting device, use multiple LED element especially, on the other hand in order to universal LED light device is strongly required cutting down cost, therefore such selection is unpractical.

Therefore, the Vf of each LED block departs from the result of desired value, if Vf value becomes higher than switched voltage value, does not then have electric current to flow through after just having switched, LED cannot be made to light, bring the generation of noise and power factor to decline.On the contrary, when the Vf of LED becomes lower than switched voltage value, its corresponding electric power is consumed without rhyme or reason by constant current circuit.Therefore, be comparatively difficult according to the action that the deviation of LED element realizes wishing, its result can produce lights the delay of switching, the decline of efficiency, lights in quality and reliability be difficult to realize in reality at LED.

Although further, LED can be made to be in ON with multiple rectangular wave by the switching of LED block in the above-mentioned methods, therefore there is the shortcoming that efficiency is still not good enough in the residual electric power be not consumed as shown in the oblique line of Figure 15.

Special in the region that voltage is the highest, existence effectively cannot utilize and LED originally can be made to carry out the problem in the region of the brightest luminescence.

Prior art document

Patent documentation

[patent documentation 1] TOHKEMY 2006-147933 publication

Summary of the invention

The present invention proposes in view of this background, its main purpose is the lighting control method providing a kind of light emitting diode drive device and light-emitting diode, higher power-efficient can be maintained, improve LED utilization ratio and power factor simultaneously, in addition the forward voltage Vf of each LED element that uses of Absorbable rod and the deviation of temperature characterisitic, stably can carry out action.

For method and the invention effect of technical solution problem

In order to realize the above object, according to the light emitting diode drive device involved by the 1st side, it possesses: rectification circuit 2, and it can be connected with AC power, for obtaining the pulsating voltage carrying out after rectification to the alternating voltage of this AC power; The LED block 11 be connected in series with the outlet side of described rectification circuit 2, be made up of multiple light-emitting diode, the 2nd LED block 12 be made up of multiple light-emitting diode, the 3rd LED block 13 be made up of multiple light-emitting diode; First switch unit, it switches based on the turn on angle of a described LED block 11 ON/OFF making described 2nd LED block 12 become the first bypass path BP1 of bypass; With the second switch unit, it, based on the turn on angle of a described LED block 11 and described 2nd LED block 12, switches the ON/OFF making described 3rd LED block 13 become the second bypass path BP2 of bypass.Thus, because based on the turn on angle switched the turn on angle of LED block each LED block, therefore electric power can be effectively utilized with the change of pulsating voltage is irrelevant, thus improve LED utilization ratio and power factor.

In addition, according to the light emitting diode drive device involved by the 2nd side, described first switch unit has: the first current control unit 21, and itself and described 2nd LED block 12 are connected in parallel, for limiting the turn on angle to a described LED block 11; First current detecting control unit 31, it is for controlling by the energising limit amount of described first current control unit 21 to a described LED block 11; With the first current detecting unit 4B, itself and a described LED block 11 are connected in series, detect the turn on angle of a described LED block 11, described second switch unit has: the second current control unit 22, itself and described 3rd LED block 13 are connected in parallel, for limiting the turn on angle to a described LED block 11 and described 2nd LED block 12; Second current detecting control unit 32, it is for controlling by the energising limit amount of described second current control unit 22 to a described LED block 11 and the 2nd LED block 12; With the second current detecting unit 4C, itself and described 2nd LED block 12 are connected in series, and detect the turn on angle of described 2nd LED block 12.Thus, turn on angle to LED block can be switched by current control unit and current detecting control unit, namely light/extinguish, therefore, it is possible to independently effectively utilize electric power with the change of pulsating voltage, thus improve LED utilization ratio and power factor.

Further, the light emitting diode drive device involved by the 3rd side, described first current detecting unit 4B and the second current detecting unit 4C is shared.Thus, because first, second current detecting control unit controls the turn on angle to LED block or current control unit respectively based on common turn on angle, so do not need to arrange separately special current detecting unit, circuit can be simplified and form.

In addition, according to the light emitting diode drive device involved by the 4th side, it possesses: rectification circuit 2, and it can be connected with AC power, for the pulsating voltage after obtaining the ac voltage rectifier of this AC power; One LED block 11, its multiple light-emitting diodes be connected in series by the outlet side with described rectification circuit 2 are formed; 2nd LED block 12, it is made up of the multiple light-emitting diodes be connected in series with a described LED block 11; 3rd LED block 13, it is made up of the multiple light-emitting diodes be connected in series with described 2nd LED block 12; Flow-restriction 3, itself and described 3rd LED block 13 are connected in series; First current control unit 21, itself and described 2nd LED block 12 are connected in parallel, for limiting the turn on angle to a described LED block 11; Second current control unit 22, itself and described 3rd LED block 13 are connected in parallel, for limiting the turn on angle to a described LED block 11 and described 2nd LED block 12; 3rd current control unit 23, itself and described flow-restriction 3 are connected in parallel, for limiting the turn on angle to a described LED block 11, the 2nd LED block 12 and described 3rd LED block 13; First current detecting control unit 31, it is for controlling by the energising limit amount of described first current control unit 21 to a described LED block 11; Second current detecting control unit 32, it is for controlling by the energising limit amount of described second current control unit 22 to a described LED block 11 and the 2nd LED block 12; With the 3rd current detecting control unit 33, it is for controlling by the energising limit amount of described 3rd current control unit 23 to a described LED block 11, the 2nd LED block 12 and the 3rd LED block 13.Thus because based on the turn on angle switched the turn on angle of LED block each LED block, namely light/extinguish, so independently effectively electric power can be utilized with the change of pulsating voltage, thus LED utilization ratio and power factor can be improved.In addition, due to lighting by Current Control control LED, therefore, it is possible to realize the most suitable action not relying on the forward voltage Vf of each LED element and the deviation of temperature characterisitic.Form further, do not need complicated control can simplify circuit, can cheapness be obtained and the high LED drive device of reliability.In addition, the effect that restraint speckle produces can also be obtained.

In addition, according to the light emitting diode drive device involved by the 5th side, can be set as being less than by the energising limit amount of described second current control unit 22 to a described LED block 11 and the 2nd LED block 12 by the energising limit amount of described first current control unit 21 to a described LED block 11, be less than by the energising limit amount of described 3rd current control unit 23 to a described LED block 11, the 2nd LED block 12 and the 3rd LED block 13 by the energising limit amount of described second current control unit 22 to a described LED block 11 and the 2nd LED block 12.Thus, after a LED block becomes ON, the 2nd LED block is first switched to ON, then the 3rd LED block is switched to ON, can lighting according to this order successively conversion LED block.In addition, for the current value flow through in LED block, its current value then suppresses lower by the LED block longer due to lighting time, therefore, it is possible to suppress caloric value, thus improves the life characteristic of light-emitting diode.

In addition, according to the light emitting diode drive device involved by the 6th side, described light emitting diode drive device also possesses at described flow-restriction 3 and the current detecting unit 4 be connected between ground wire, described first current detecting control unit 31, second current detecting control unit 32, the 3rd current detecting control unit 33, based on the turn on angle of described current detecting unit 4, limit the turn on angle to a described LED block 11, the 2nd LED block 12, the 3rd LED block 13 respectively.Thus, because each current detecting control unit controls the turn on angle to LED block or current control unit respectively based on common turn on angle, so do not need to arrange separately special current detecting unit, circuit can be simplified and form.

Further, the light emitting diode drive device involved by the 7th side, also possess at the outlet side of described rectification circuit and the capacitor be connected between ground wire.Thereby, it is possible to avoid the so-called stroboscopic phenomenon that light-emitting diode in the region that pulsating voltage is lower all extinguishes.

In addition, the lighting control method of the light-emitting diode involved by the 8th side, it comprises: obtain the pulsating voltage carrying out after rectification to AC power; This pulsating voltage is put on mutually be connected in series, be one another in series multiple light-emitting diode the LED block, the 2nd LED block, the 3rd LED block that connect; Can switch and to be connected in parallel with described 2nd LED block thus to make the 2nd LED block become first current control unit of the ON/OFF of the first bypass path of bypass, based on the turn on angle of a described LED block, when this turn on angle is below setting, the first bypass path is switched to ON, when this turn on angle exceedes setting, the first bypass path is switched to OFF; Under the state that described first bypass path is switched to OFF thus described 2nd LED block is energized, can switch and to be connected in parallel with described 3rd LED block thus to make the 3rd LED block become second current control unit of the ON/OFF of the second bypass path of bypass, based on the turn on angle of described 2nd LED block, when this turn on angle is below setting, the second bypass path is switched to ON, when this turn on angle exceedes setting, the second bypass path is switched to OFF.Thus because based on the turn on angle switched the turn on angle of LED block each LED block, namely light/extinguish, so independently effectively electric power can be utilized with the change of pulsating voltage, thus LED utilization ratio and power factor can be improved.In addition, due to lighting by Current Control control LED, therefore, it is possible to realize the most suitable action not relying on the forward voltage Vf of each LED element and the deviation of temperature characterisitic.Form further, do not need complicated control can simplify circuit, can cheapness be obtained and the high LED drive device of reliability.In addition, the effect that restraint speckle produces can also be obtained.

In addition.The lighting control method of the light-emitting diode involved by the 9th side, also comprise the steps: under the state that described second bypass path is switched to OFF thus described 3rd LED block is energized, can switch and to be connected in parallel with the flow-restriction being connected in series in described 3rd LED block thus to make this flow-restriction become the 3rd current control unit of the ON/OFF of the 3rd bypass path of bypass, based on the turn on angle of described 3rd LED block, when this turn on angle is below setting, the 3rd bypass path is switched to ON, when this turn on angle exceedes setting, the 3rd bypass path is switched to OFF.

Accompanying drawing explanation

Fig. 1 is the block diagram of the light emitting diode drive device represented involved by execution mode 1.

Fig. 2 is the circuit diagram of the light emitting diode drive device represented involved by embodiment 1.

Fig. 3 be represent pulsating voltage is inputed to Fig. 2 circuit in time the curve of current waveform.

Fig. 4 is the curve of the current waveform of the light emitting diode drive device represented involved by embodiment 2.

Fig. 5 is the circuit diagram of the light emitting diode drive device represented involved by embodiment 3.

Fig. 6 is the block diagram of the light emitting diode drive device represented involved by embodiment 4.

Fig. 7 is the circuit diagram of the light emitting diode drive device represented involved by embodiment 5.

Fig. 8 is the circuit diagram representing existing LED drive circuit.

Fig. 9 is the circuit diagram representing other LED drive circuits existing.

Figure 10 be represent ac voltage rectifier after the curve of waveform of pulsating voltage.

Figure 11 is the curve of the LED driving voltage represented based on full-wave rectifier power supply.

Figure 12 is the circuit diagram representing the LED lighting circuit example using microcomputer.

Figure 13 is the sequential chart of the action of the LED lighting circuit representing Figure 12.

Figure 14 is the circuit diagram representing the LED lighting circuit example not using microcomputer.

Figure 15 is the sequential chart of the action of the LED lighting circuit representing Figure 14.

Figure 16 is the circuit diagram representing the light emitting diode drive device using film capacitor.

Figure 17 is the curve of the input voltage waveform represented in the circuit of Figure 16.

Figure 18 is the curve of the time variations of the light beam of the circuit represented based on Figure 16.

Figure 19 is the circuit diagram of the light emitting diode drive device represented involved by embodiment 6.

Figure 20 is the curve of the input voltage waveform represented in the circuit of Figure 19.

Figure 21 is the curve of the time variations of the light beam of the circuit represented based on Figure 19.

Embodiment

Below, based on accompanying drawing, embodiments of the present invention are described.But, execution mode shown below has illustrated for specializing the light emitting diode drive device of technological thought of the present invention and the lighting control method of light-emitting diode, and the lighting control method of light emitting diode drive device and light-emitting diode is defined as following content by the present invention.In addition, this specification is not the parts parts shown in claim being defined as execution mode.The size, material, shape, its relative configuration etc. of the component parts particularly recorded in execution mode, as long as no specific record, are not just meanings scope of the present invention being defined in this, and are only illustrative examples.Moreover in order to be described clearly, the size of the parts shown in each drawing and position relationship etc. are exaggerated sometimes.Further, in the following description, for same title, symbol, represent parts that are identical or homogeneity, suitably description is omitted.Further, for formation each key element of the present invention, also can be form multiple key element by same parts thus by the mode of a multiple key element of parts dual-purpose, on the contrary, the function also can sharing parts by multiple parts realizes.In addition, the content illustrated in the embodiment, execution mode of a part also can be used in other embodiment, execution mode etc. sometimes.

Fig. 1 represents the block diagram of the light emitting diode drive device involved by execution mode.Light emitting diode drive device 100 shown in this figure is connected with AC power AP, the rectification circuit 2 of the pulsating voltage (pulsatingcurrentvoltage) after being used for obtaining to ac voltage rectifier, the LED block group 1 be made up of multiple LED block, flow-restriction 3, current detecting unit 4 is connected in series respectively.At this, use three LED blocks, a LED block 11, the 2nd LED block 12, the 3rd LED block 13 are connected in series and form LED block group 1.Moreover, in this manual, so-called key element " series connection " to be connected, as long as no special provision, just do not consider the order that connects is how, in addition to the form therebetween inserting additional key element, as long as maintain in the type of attachment of connecting is also included within.Such as, except connecting according to the order of a LED block 11, the 2nd LED block 12, the 3rd LED block 13, flow-restriction 3, current detecting unit 4, can also connect according to the order of a LED block 11, the 2nd LED block 12, current detecting unit 4, the 3rd LED block 13, flow-restriction 3.

In addition, at the two ends that the 2nd LED block 12, the 3rd LED block 13, flow-restriction 3 are respective, the current control unit for limiting turn on angle is connected.Because each current control unit is arranged side by side relative to LED block or flow-restriction 3 respectively, therefore form bypass path.That is, owing to can adjust by the magnitude of current of each current control unit bypass, therefore result can limit the turn on angle of each LED block.In the example in fig 1, be connected the first current control unit 21 in parallel with the 2nd LED block 12, form the first bypass path BP1.In addition, be connected the second current control unit 22 in parallel with the 3rd LED block 13, form the second bypass path BP2.Further, be connected the 3rd current control unit 23 in parallel with flow-restriction 3, form the 3rd bypass path BP3.

Moreover in the example in fig 1, flow-restriction 3 is used as the LED current-limiting resistance of resistor, and the protective resistance as LED plays a role.In addition, current detecting unit 4 also can use resistor, to be detected and is connected in series by LED block and the electric current that flows through in the LED block group 1 that obtains, carry out the constant current driven of the LED element forming LED block by this current detecting unit 4 based on voltage degradation.In addition, in order to carry out constant current driven, current detecting control unit is set, for controlling constant current circuit.In this circuit example, form a kind of constant current circuit by current control unit and current detecting control unit.

Current detecting control unit is connected with current control unit, controls the ON/OFF of current control unit and this action of magnitude of current continuous variable.Specifically, the 3rd current detecting control unit 33 of the second current detecting control unit 32 of the first current detecting control unit 31 being provided with the action of control first current control unit 21, the action controlling the second current control unit 22, the action of control the 3rd current control unit 23.Each current detecting control unit monitors the magnitude of current of LED, based on the controlled quentity controlled variable of its value switch current control unit.

The block that LED block is series connection and/or is connected in parallel multiple LED element and obtains.LED element suitably can utilize the LED of surface installing type (SMD) and ball-type.In addition, the packaging appearance of the LED element of SMD type can be selected according to purposes, the type of overlooking as rectangular shape can be utilized.Further, series connection in encapsulation and/or the LED being connected in parallel multiple LED element and obtaining can certainly be used as LED block.

Namely the additive value of the forward voltage of the LED element comprised in each LED block amounts to forward voltage, determines according to the number of the LED element be connected in series.Such as, total forward voltage when using the LED element of 8 forward voltage 3.6V is 3.6 × 8=28.8V.But, because each individuality of LED element exists characteristic deviation, the total forward voltage therefore as its additive value generally neither be constant.Therefore, also there is deviation in the total forward voltage of each LED block.

The current value that this light emitting diode drive device 100 detects based on current detecting unit 4, switches the ON/ constant current control/OFF of the energising for each LED block.In other words, owing to being the Current Control based on the magnitude of current passed through in reality, instead of the Current Control of magnitude of voltage based on commutating voltage, therefore the impact of the forward voltage deviation of LED element can not be subject to, the switching of correct LED block can be realized according to suitable timing, the stable action that reliability is high can be expected.

Specifically, in the example in fig 1, the first current detecting control unit 31, based on the turn on angle of a LED block 11, controls the energising limit amount of the first current control unit 21 to a LED block 11.Specifically, when turn on angle is higher than the first reference current value preset, the 2nd LED block 12 is switched to ON, enters constant current action, switching to OFF lower than during the first reference current value.Have again, second current detecting control unit 32 is based on the turn on angle of the 2nd LED block 12, the ON/ constant current control/OFF of the 2nd LED block 12 is switched, to control the energising limit amount of the second current control unit 22 to the 2nd LED block 12 according to the second reference current value preset.Equally, 3rd current detecting control unit 33 is also based on the turn on angle of the 3rd LED block 13, the energising ON/ constant current control/OFF to the 3rd LED block 13 is switched, to control the energising limit amount of the 3rd current control unit 23 to the 3rd LED block 13 according to the 3rd reference current value preset.

At this, by being set as the first reference current value < second reference current value < the 3rd reference current value, ON/ constant current control/OFF can be switched successively according to the order of the 2nd LED block 12 from a LED block 11, the 3rd LED block 13, flow-restriction 3.

As above-mentioned, light emitting diode drive device possesses multiple constant current circuit, the plurality of constant current circuit is configured to: the AC power utilizing domestic power supply etc., with exchanged carry out full-wave rectification after the periodically variable pulsating voltage that obtains matchingly, light the LED element of the configured in series of suitable number, make multiple LED current testing circuit carry out action to make the mode of each constant current circuit suitably action respectively.

Like this, light emitting diode drive device makes 1LED block 11 be energized with the 1st current value, with the 2nd current value being greater than the 1st current value, 1LED block 11 and 2LED block 12 are energized, and then with the 3rd current value being greater than the 2nd current value, 1LED block 11,2LED block 12,3LED block 13 are energized.Especially, control to limit the turn on angle to each LED block by constant current, the ON/ constant current control/OFF of LED block can be switched according to the magnitude of current, effectively can light driving LED for pulsating voltage.

Moreover LED block can be configured to multiple light-emitting diode to be one another in series connection respectively.Thereby, it is possible to effectively carry out dividing potential drop with multiple light-emitting diode to pulsating voltage, the forward voltage Vf of each light-emitting diode and the deviation of temperature characterisitic can be absorbed to a certain extent, the control homogenization in units of block can be made.But, for LED block quantity or form the light-emitting diode number etc. of each LED block, can according to the setting arbitrarily such as required brightness and input voltage, such as both can form LED block by a light-emitting diode, increase the quantity of LED block thus carry out more careful control, or LED block being set as only 2 thus simplify and control on the contrary.

(embodiment 1)

Next, as embodiment 1, figure 2 illustrates the concrete circuit configuration example adopting semiconductor element to realize the structure of Fig. 1.In the light emitting diode drive device 200 shown in this figure, adopt diode bridge as the rectification circuit 2 be connected with AC power AP.In addition, protective resistance 17 is set between AC power AP and rectification circuit 2.Further, connect by-pass capacitor 19 at the outlet side of rectification circuit 2.

(AC power AP)

AC power AP suitably can utilize the source power supply of 100V.The 100V of this source power supply is effective value, is about 141V by the maximum voltage of the rectified waveform after full-wave rectification.

(LED block)

Each LED block is connected in series mutually, and is divided into multiple pieces, from block border leading-out terminal each other, is connected with current control unit.In the example in figure 2, LED block group 1 is formed by three groups of a LED block 11, the 2nd LED block 12, the 3rd LED block 13.Moreover, represent each LED block with a LED in fig. 2, but each LED block is connected in series multiple light-emitting diode and forms.The light-emitting diode number of connection of each LED block or the number of connection of LED block, the sum of the LED element be namely connected in series by the additive value of forward voltage and the supply voltage used decide.Such as when using source power supply, namely the total of the Vf of each LED block adds up to forward voltage Vfall to be set to about 141V or below it.

Moreover in the example in figure 2, the Vf being designed to three LED blocks is identical.But, be not limited to this example, also LED block number can be set as more than 2 or 4.Further, the Vf of each LED block also can not be identical.

(current control unit)

Current control unit corresponds to each LED block for carrying out the parts of constant current driven.As this current control unit, be made up of the switch element of transistor etc.Especially, due to FET source drain between saturation voltage be roughly zero, therefore can not hinder the turn on angle to LED block, preferably be made up of FET.But, current control unit is not limited to FET, certainly also can be made up of bipolar transistor or comparator, operational amplifier, variable resistor etc.

In the example in figure 2, control transistor as the LED current forming current control unit, use FET.In this FET, between gate terminal with source terminal, be connected gate protection Zener diode respectively.Specifically; first grid protection Zener diode 24 is connected between the gate-to-source of the first LED current control transistor 21A; between the gate-to-source of the second LED current control transistor 22A, connect second grid protection Zener diode 25, between the gate-to-source of the 3rd LED current control transistor 23A, connect the 3rd gate protection Zener diode 26.

In addition, resistance is connected respectively at the gate terminal of each LED current control transistor.Specifically, the gate terminal controlling transistor 21A in the first LED current connects first grid resistance 27, the gate terminal controlling transistor 22A in the second LED current connects second grid resistance 28, and the gate terminal controlling transistor 23A in the 3rd LED current connects the 3rd resistance 29.These each LED current control transistor and are controlled by the collector voltage of the current detecting transistor combined separately.

Moreover; control transistor 21A utilizing the first LED current, the second LED current controls transistor 22A; in the structure of the switching of control ON/OFF in units of LED block; the control semiconductor element controlling the FET of transistor etc. owing to forming LED current at different levels is connected to the two ends of LED block, and therefore the withstand voltage total forward voltage by LED block of control semiconductor element is protected.Therefore, there is the advantage that can use the resistance to small-sized semiconductor element forced down.

(current detecting control unit)

Current detecting control unit carries out according to the current control unit corresponding with LED block the parts that control in the mode that constant current driven is carried out in suitable timing.As current detecting control unit, the switch element of transistor etc. also can be utilized.Particularly bipolar transistor is applicable to the detection being applied to the magnitude of current.In this embodiment, first current detecting control unit 31 is made up of the first current detecting transistor 31A, second current detecting control unit 32 is made up of the second current detecting transistor 32A, and the 3rd current detecting control unit 33 is made up of the 3rd current detecting transistor 33A.Moreover current detecting control unit is also not limited to bipolar transistor, certainly also can be made up of MOSFET, comparator, operational amplifier, variable resistor etc.

In the example in figure 2, current detecting control unit is formed by current detecting transistor.Each current detecting transistor controls the action that LED current controls transistor respectively.That is, each current detecting transistor is in ON/ constant current control/OFF, thus LED current is controlled transistors switch to OFF/ constant current control/ON.

On the other hand, the LED current forming current detecting unit 4 detects resistance 4A, is connected to the base terminal of each current detecting transistor via base resistance.Specifically, the first base resistance 41 is connected at the base terminal of the first current detecting transistor 31A, the second base resistance 42 is connected at the base terminal of the second current detecting transistor 32A, connect the 3rd base resistance 43 at the base terminal of the 3rd current detecting transistor 33A, each base resistance is connected to each base terminal and LED current detects between resistance 4A.

In addition, between the base terminal and ground wire of the second current detecting transistor 32A, connect the second base bleederresistance 34, and then between the base terminal and ground wire of the 3rd current detecting transistor 33A, connect the 3rd base bleederresistance 35.The action of these second, third current detecting transistors is set by base current and base resistance and base bleederresistance.Moreover ground wire is in this manual not limited to what is called and is connected to the earth, certainly also comprises imaginary earth point.Such as, the metallic casing of lighting device can be used as imaginary earth point.

The resistance value that each base resistance, base bleederresistance and LED current detect resistance 4A specifies that timing according to which electric current is to carry out the ON/OFF of each current detecting transistor.At this, be set to the mode of ON according to the order of the first current detecting transistor 31A, the second current detecting transistor 32A, the 3rd current detecting transistor 33A, set the resistance value of each base resistance and base bleederresistance.

(reference current value)

At this, first reference current value is set lower than the second reference current value, wherein the first reference current value is that the first current detecting transistor 31A makes the first LED current control transistor 21A switch to the reference current value of OFF from ON, and the second reference current value is that the second current detecting transistor 32A makes the second LED current control transistor 22A switch to the reference current value of OFF from ON.In addition, the 3rd reference current value being made by the 3rd current detecting transistor 33A the 3rd LED current control transistor 23A switch to OFF from ON sets higher than the second reference current value.Like this, by being set as the first reference current value < second reference current value < the 3rd reference current value, can as described above according to a LED block 11, the 2nd LED block 12, the 3rd LED block 13, the flow-restriction 3 i.e. order of LED current-limiting resistance 3A, switch to ON from OFF, and when switching to OFF from ON, order is contrary.

Moreover in this embodiment, because each LED block and flow-restriction 3 are connected in series, the magnitude of current flowing through them is consistent.Thus, detect the turn on angle of resistance 4A based on the current detecting unit 4 i.e. LED current be connected in series with them, perform the ON/OFF that LED current at different levels controls transistor and switch.

Further, connect transistor load resistance respectively at the collector terminal of each current detecting transistor.Specifically, at the collector terminal sub-connection the first transistor load resistance 36 of the first current detecting transistor 31A, at the collector terminal sub-connection transistor seconds load resistance 37 of the second current detecting transistor 32A, at the collector terminal sub-connection third transistor load resistance 38 of the 3rd current detecting transistor 33A.According to the total forward voltage V rising to a LED block 11 at pulsating voltage _fB1near before, each LED current controls the mode that transistor 21A, 22A, 23A become ON, set these transistor load resistance 36,37,38 respective resistance values.

(action specification)

This light emitting diode drive device 200 can maintain the power-efficient of more than 90%, improve LED utilization ratio and power factor simultaneously, and be made up of the circuit based on semiconductor element, therefore can realize the device of excellence in small-sized, thermal endurance under LED utilizes environment.Below, with reference to the current waveform of Fig. 3, the action of current detecting control unit when to input the pulsating voltage of Figure 10 in the circuit example of Fig. 2 and current control unit is described.Putting on the input voltage of LED block group 1, is the pulsating voltage utilizing the interchange of rectification circuit 2 pairs of source power supplies to carry out the Figure 10 after rectification.At this, study the action of 1 cycle portions.First, the total forward voltage V of a LED block 11 is risen at voltage from 0V _fB1during, stop electric current by a LED block 11.Therefore, as shown in Figure 3, the interval not having electric current to flow through is produced.When the LED element of the above-mentioned forward voltage 3.6V of use 8, owing to amounting to forward voltage V _fB1being 3.6 × 8=28.8V, is therefore no power between 0V ~ 28.8V at pulsating voltage.

Next, when pulsating voltage rises to the total forward voltage V of a LED block 11 _fB1time neighbouring, due to the first LED current in the circuit diagram of Fig. 2 control transistor 21A, the second LED current controls transistor 22A, the 3rd LED current controls transistor 23A and all becomes ON, therefore the first bypass path BP1, the second bypass path BP2, the 3rd bypass path BP3 are all open-minded.Its result, electric current controls transistor 21A → the second LED current in LED block 11 → the first LED current and controls to begin to flow through in the path of transistor 22A → the 3rd LED current control transistor 23A → current sense resistor 4A.Along with the rising of pulsating voltage, because the electric current flowing through a LED block 11 also increases, therefore the magnitude of current increases gradually as shown in Figure 3.And then along with the increase of the magnitude of current, the magnitude of current flowing to LED current detection resistance 4A by the first bypass path BP1, the second bypass path BP2, the 3rd bypass path BP3 from a LED block 11 also rises.

And then when pulsating voltage rises the electric current reaching and set by LED current detection resistance 4A, the first current detecting transistor 31A be connected with base terminal by the first base resistance 41 becomes ON, starts energising.Along with the rising of pulsating voltage, the collector current of the first current detecting transistor 31A increases gradually, and the voltage drop of its result the first transistor load resistance 36 becomes large, and the collector voltage of the first current detecting transistor declines.Therefore, the grid voltage that the first LED current controls transistor 21A declines, and switches to OFF from ON.Its result, the first bypass path BP1 is cut off, and starts to be energized to the 2nd LED block 12.Now, to switch to the transfer of OFF from ON at the first current control transistor 21A during, namely pulsating voltage reach the total forward voltage V of a LED block 11 and the 2nd LED block 12 _fB1+ V _fB2before, the 2nd LED block 12 can not be lighted, and a LED block 11 is by constant current driven.Its result, becomes the level of the I-1 in Fig. 3.

In this condition, the total forward voltage V of a LED block 11 and the 2nd LED block 12 is reached when pulsating voltage continues to rise _fB1+ V _fB2time, the 2nd LED block 12 starts to be lit, and current value starts to rise again as shown in Figure 3.Further, electric current increases gradually, and LED current detects the magnitude of current flow through in resistance 4A and also rises, and when its result reaches the current value set by the second base resistance 42 and the second base bleederresistance 34, the second current detecting transistor 32A starts action.Like this, the collector current of the second current detecting transistor 32A increases gradually, causes the voltage drop of transistor seconds load resistance 37 to increase.Thus, the grid voltage that the second LED current controls transistor 22A declines, and switches to OFF from ON, and cut-off beginning of the second bypass path BP2 is energized to the 3rd LED block 13.Now, the total forward voltage V of LED block the 11 ~ three LED block 13 is reached at pulsating voltage _fB1+ V _fB2+ V _fB3before, the 3rd LED block 13 is not lit, and the 2nd LED block 12 is by constant current driven.Its result, becomes the level of the I-2 in Fig. 3.

Equally, also ON/OFF switching and constant current driven is carried out for the 3rd LED block 13.That is, when pulsating voltage reaches the total forward voltage V of LED block the 11 ~ three LED block 13 _fB1+ V _fB2+ V _fB3time, the 3rd LED block 13 starts to light, and current value starts to rise again as shown in Figure 3.Further, LED current detects the magnitude of current flow through in resistance 4A and rises, and when reaching the current value set by the 3rd base resistance 43 and the 3rd base bleederresistance 35, the 3rd current detecting transistor 33A starts action.Further, the collector current of the 3rd current detecting transistor 33A increases gradually, and the voltage drop of third transistor load resistance 38 increases.Thus, the grid voltage that the 3rd LED current controls transistor 23A declines, and switches to OFF from ON, and the 3rd bypass path BP3 is cut off thus starts to be energized to LED current-limiting resistance 3A.Now, the voltage V of LED block 11 ~ LED current-limiting resistance 3A is reached at pulsating voltage _fB1+ V _fB2+ V _fB3+ V _f3Abefore, LED current-limiting resistance 3A is not energized, and the 3rd LED block 13 is by constant current driven.Its result, achieves the level of the I-3 in Fig. 3.

In addition, become near maximum voltage at pulsating voltage, all LED current control transistor 21A, 22A, 23A and become OFF completely, detect resistance 4A flow through electric current by LED current-limiting resistance 3A and LED current in all LED.Thereby, it is possible to effectively utilize the electric power near maximum voltage.But, the current control unit for final level may not make it be in OFF, even if such as make LED current control the state of transistor 23A maintenance ON, also can flow through electric current in all LED.In this case, make LED current control transistor 23A and be not in OFF, also can implement constant current with the peak fractions of input voltage and control Limited Current value.

Moreover when pulsating voltage reaches maximum voltage 141V, magnitude of voltage changes minimizing into, represents pattern contrary to the above.Further, after pulsating voltage reaches the OV as minimum voltage, be again converted to rising, therefore above-mentioned action repeatedly.

Like this, detected the setting of the base bleederresistance of resistance 4A and current detecting transistor by LED current, the level of constant current driven can be carried out by free setting.In addition, in foregoing circuit example, do not use coil and bulky capacitor capacitor, small-sized, cheap, light weight, high performance LED drive device can be realized.And then do not use HF switch, this can expect to suppress high order harmonic component noise.

In addition, due to the control that the magnitude of current carried out in the methods described above to reality flows through in LED block etc. is corresponding, therefore, it is possible to do not rely on the individual difference of characteristic deviation, the particularly Vf of each LED element, carry out correct lighting control.Further, can realize with open-and-shut circuit structure owing to controlling itself, therefore do not need the control element of this high price of microcomputer, can only be made up of semiconductor element, also can obtain the advantage suppressing lower by cost.

According in measured value when becoming the mode forming circuit constant of the LED current waveform shown in Fig. 3, power-efficient=90%, LED utilization ratio=50%, power factor are 98%, can confirm to improve LED utilization ratio and power factor relative to constant current circuit.

Moreover in said structure, the utilization ratio of 3 LED blocks is different.The power ratio of an each LED block when LED block the highest for utilization ratio being set to 100 is a LED block: the 2nd LED block: the 3rd LED block=100: 95: 74.But, even if produce illumination difference between LED block, with the visual level that can clearly identify, by making an effort in the configuration of LED element, thus the level can avoiding affecting neither can be reached, no problem in practical application.

In said structure, compared with the circuit of the Figure 14 as conventional example, its advantage is to realize action that can be corresponding with the temperature characterisitic deviation of the Vf deviation of light-emitting diode and Vf.That is, in the circuit example of Figure 14, lighting of each LED block is switched with input voltage.Therefore, need to make the switched voltage value lighted of switching LED block correctly consistent with the Vf value of the LED element forming each LED block.But because LED element exists individual difference, there is deviation in each interelement Vf and temperature characterisitic, it is very difficult for therefore making switched voltage correctly consistent with the Vf of LED element in reality.

In contrast, in the above-described embodiments, carry out the switching of each LED block based on electric current, instead of carry out based on voltage.That is, constant current control is carried out to each LED block, change its current value switched for each LED block simultaneously, thus switch lighting of LED block successively.In other words, relative to being controlled to be set as identical current value by the constant current of each LED block in fig. 14, the current value making the constant current of each LED block control in the present embodiment is different.If this method, its result controls the Vds voltage broadening of the FET of transistor as LED current, to making other LED BOB(beginning of block)s of current bypass be energized while carrying out constant current control with FET.Like this, according to the present embodiment, due to the action of the deviation absorbing Vf and temperature characterisitic easily can be realized, therefore, it is possible to provide and practical and useful circuit formation.

In addition, be constant relative to the turn on angle of LED block in the circuit example of Figure 14, by different constant current control break current values in said structure.Thus, the magnitude of current of the LED block suppressing lighting time long, realizes long lifetime.Specifically, the constant current controlled quentity controlled variable of the LED block the making lighting time the longest controlled quentity controlled variable that is namely energized is minimum, and the energising controlled quentity controlled variable of the 3rd LED block making lighting time the shortest is maximum.Its result, because current value when lighting a LED block when the 3rd LED block extinguishes diminishes, therefore can also suppress its caloric value (current value × lighting time).That is, the deterioration of LED block when contrasting with the 3rd LED block can be suppressed.Same situation with the relation of the 2nd LED block in also can realize.Like this, the magnitude of current not making constant current control is constant, but change according to the mode that the LED block that lighting time is longer is lower, can relax the uneven homogenize of life-span (life) characteristic of light-emitting diode thus, what can realize the light-emitting diode of stable use in more long-term process lights control.

In addition, as the circuit example like that power factor deterioration when making current value constant of Figure 14, but by making current waveform close to input voltage waveform thus the effect of the power factor that can be improved as shown in Fig. 3 etc.

(embodiment 2)

Above action is the control considering power factor.Special in the circuit example of Fig. 2, owing to being structure LED block group 1 be serially connected in single line, therefore by carrying out constant current control with different current values respectively to each LED block, make current waveform become stepped thus as illustrated in the graph of fig. 3 like that.On the other hand, the circuit of Fig. 2 is utilized to carry out the example of the control more paying attention to utilization ratio compared with power factor as representing in the current waveform of embodiment 2, Fig. 4.In this control example, compared with the example of Fig. 3, according to making the constant current of each LED block control approximating mode to set resistance value etc., improving output by increasing the overall magnitude of current, obtaining brighter illumination light.As the LED current waveform shown in Fig. 4, measured value during forming circuit constant is power-efficient=90%, LED utilization ratio=53%, power factor 95%, compared with embodiment 1, although power factor has a little decline, can confirm to improve LED utilization ratio.Like this, even if circuit forms identical, by selection circuit constant, the lighting device corresponding to required specification can be formed.

(embodiment 3)

In the example above, it is common for making LED current detect resistance in each LED block etc.That is, each current detecting control unit controls based on the magnitude of current of common current detecting unit, can simplify circuit and form.But, the structure that LED current detection resistance is individually set for each LED block etc. can also be adopted.As embodiment 3, in the circuit diagram of Fig. 5, represent such example.In the light emitting diode drive device 300 shown in this figure, basic structure is roughly the same with embodiment 1 with action, arranges LED current respectively detect resistance for 3 LED blocks.Specifically, the current detecting that resistance 4B carries out a LED block 11 is detected by the first LED current, detect by the second LED current the current detecting that resistance 4C carries out a LED block 11 and the 2nd LED block 12, detect by the 3rd LED current the current detecting that resistance 4D carries out a LED block 11, the 2nd LED block 12, the 3rd LED block 13.In addition, in this embodiment, control transistor as the LED current forming current control unit, use FET but use bipolar transistor, further, make the Darlington transistor that 2 bipolar transistors formation Darlingtons connect.

In the circuit of Fig. 5, can control according to the mode making its current waveform become Fig. 3 or Fig. 4.At this, illustrate use the circuit of Fig. 5 to carry out the example controlling the current waveform making to become Fig. 3 time, the pulsating voltage this point that the protected resistance of alternating voltage 17 of source power supply, rectification circuit 2 carry out rectification and become Figure 10 is identical with embodiment 1.Moreover, in the circuit example of Fig. 5, do not use by-pass capacitor.The total forward voltage V of a LED block 11 is risen to from 0V at voltage _fB1during, stop electric current by a LED block 11, do not have electric current to flow through.Forward voltage V is amounted to when pulsating voltage rises to _fB1time neighbouring, because the first LED current in the circuit diagram of Fig. 5 controls transistor 21B, second LED current controls transistor 22B, 3rd LED current controls transistor 23B and all becomes ON, therefore the first bypass path BP1, second bypass path BP2, 3rd bypass path BP3 is all switched on, the path that electric current detects resistance 4B → the second LED current control transistor 22B → the second LED current detection resistance 4C → the 3rd LED current control transistor 23B → the 3rd LED current detection resistance 4D according to LED block 11 → the first LED current control transistor 21B → the first LED current begins to flow through.Along with the rising of pulsating voltage, the electric current flowing through a LED block 11 increases, and the first LED current detects the magnitude of current flow through in resistance 4B and also rises.

Further, when pulsating voltage raises the electric current reaching and set by the first LED current detection resistance 4B, the first current detecting transistor 31B be connected with base terminal by the first base resistance 41B becomes ON, starts energising.Along with the rising of pulsating voltage, the collector current of the first current detecting transistor 31B increases gradually, and the base current that its result flow to the first current control transistor 21B from the first transistor load resistance 36B reduces, and switches to OFF from ON.Its result first bypass path BP1 is cut off, and starts to be energized to the 2nd LED block 12.Now, the total forward voltage V of a LED block 11 and the 2nd LED block 12 is reached at pulsating voltage _fB1+ V _fB2before, the 2nd LED block 12 is not lit, and a LED block 11 is by constant current driven.

Pulsating voltage rises in this condition, when reaching the total forward voltage V of a LED block 11 and 2LED block 12 _fB1+ V _fB2time, the 2nd LED block 12 starts to light.Also gradually rise further, the second LED current detects the magnitude of current flow through in resistance 4C, when its result reaches the current value set by the second base resistance 42B, the second current detecting transistor 32B starts action.And, the collector current of the second current detecting transistor 32B increases gradually, its result controls transistor 22B side branch electric current from transistor seconds load resistance 37B to the second LED current from reduces, the base current that second LED current controls transistor 22B declines, OFF is switched to from ON, second bypass path BP2 is cut off, thus starts to be energized to the 3rd LED block 13.Now, the total forward voltage V of LED block the 11 ~ three LED block 13 is reached at pulsating voltage _fB1+ V _fB2+ V _fB3before, the 3rd LED block 13 is not lit, and the 2nd LED block 12 is by constant current driven.

Equally, when pulsating voltage reaches the total forward voltage V of LED block the 11 ~ three LED block 13 _fB1+ V _fB2+ V _fB3time, the 3rd LED block 13 starts to light, and current value starts to rise again.Further, the 3rd LED current detects the magnitude of current flow through in resistance 4D and rises, and when reaching the current value set by the 3rd base resistance 43B, the 3rd current detecting transistor 33B starts action.Have again, the collector current of the 3rd current detecting transistor 33B increases gradually, flow to the 3rd LED current from third transistor load resistance 38B and control the electric current of transistor 23B to the 3rd current detecting transistor 33B side branch, the base current that 3rd LED current controls transistor 23B reduces, OFF is switched to from ON, 3rd bypass path BP3 is cut off, thus starts to be energized to LED current-limiting resistance 3B.

Become near maximum voltage at pulsating voltage, all LED current control transistor 21B, 22B, 23B and are in OFF completely, detect resistance 4B by LED current-limiting resistance 3B and the first LED current, the second LED current detects resistance 4C, the 3rd LED current detects resistance 4D, in all LED, flow through electric current.Thereby, it is possible to effectively utilize the power near maximum voltage.In addition, when pulsating voltage reaches maximum voltage 141V, magnitude of voltage changes minimizing into, occurs action contrary to the above.

In this circuit example, easily can detect resistance by each LED current and adjust separately the current value making each LED block and flow-restriction 3 action.On the contrary, its shortcoming is, use multiple LED current to detect resistance, thus the thermal losses caused by these resistance increases, and LED block is cut off into module.On the other hand, as advantage, such as have different from Fig. 2 etc. do not have to connect up intersect, do not need three-dimensional wiring thus circuit forms and becomes easy.Moreover, in above circuit, by the first current control unit 21, first current detecting control unit 31, first current detecting unit 4B, form the first switch unit switching the ON/OFF of the first bypass path BP1 based on the turn on angle of a LED block 11, in addition, second switch unit of the ON/OFF of the second bypass path BP2 is switched by the second current control unit 22, second current detecting control unit 32, second current detecting unit 4C turn on angle formed based on a LED block 11 and the 2nd LED block 12.

In above embodiment 1 ~ 3, be all switch to ON according to the order from LED BOB(beginning of block) a 2nd LED block, the 3rd LED block, and then switch to OFF according to the order from the 3rd LED BOB(beginning of block) the 2nd LED block, a LED block.Therefore, the lighting time of each LED block is different.Like this, in order to avoid long the 3rd LED block etc. during extinguishing becomes eye-catching, for the configuration of LED element, preferably make it disperse to be configured, instead of each LED block become a pile.Such as, in the lighting device of Fig. 6 described later, often row configuration belong to a LED block LED element, belong to the 2nd LED block LED element, belong to the 3rd LED block LED element so that first, second, third,, alternately configure LED element.Or, not with behavior unit, but in units of point, from upper left right side configuration belong to a LED block LED element, belong to the 2nd LED block LED element, belong to the 3rd LED block LED element so that first, second, third,, the different LED element of LED block belonging to a next ground configuration to the right successively.In addition, be not limited to configure singly, also can every 2 or every more than 3 be unit or be not periodic arrangement but the structure etc. of arrangement at random, suitably make LED block disperse to configure LED element, the difference of lighting time can be made to become not obvious.Thus, even if repeatedly light with the 60Hz cycle of source power supply, user also not can be appreciated that flicker, utilizes in the same manner as can lighting continuously with LED element.In addition, even if use inverter circuit etc. in addition, accelerate ignition period, also can obtain same effect.

Moreover in said structure, the service time of each LED element is different in each LED block.Specifically, the lighting time of a LED block is the longest, and the lighting time of the 3rd LED block is the shortest.Therefore, the deviation of the component life that suppression causes because of usage frequency can be considered.In foregoing circuit is formed, because LED block is one another in series connection, therefore the voltage control of each LED block is comparatively difficult.Therefore, for the LED block that usage frequency is high, increase the LED element quantity connected, be not only connected in series and be also connected in parallel, to reduce the magnitude of current of each element, suppress thermal losses.

In addition, in said structure, LED block number is set as 3, but LED block number also can be set as more than 2 or 4 as mentioned above.Such as, in the light emitting diode drive device of Fig. 1, also possess: at the 3rd LED block and the 4th LED block be made up of multiple light-emitting diode be connected between flow-restriction; The 4th current control unit for limiting the turn on angle to a LED block, the 2nd LED block, the 3rd LED block and the 4th LED block be connected in parallel with flow-restriction; For controlling the 4th current detecting control unit of the energising limit amount to a LED block, the 2nd LED block, the 3rd LED block and the 4th LED block of being undertaken by the 4th current control unit.At this, the 3rd current control unit replaces flow-restriction and the 4th LED block to be connected in parallel.Thus, increase LED block quantity thus can carry out more careful LED interblock light switching controls, improve LED utilization ratio further.In addition, LED block number also can be increased to more than 5, can carry out thus more careful lighting switching controls.

(embodiment 4)

The light emitting diode drive device 400 being 4 using this LED block number represents its circuit diagram in embodiment 4, Fig. 6.Light emitting diode drive device shown in this figure is different from Fig. 1 etc., arranges the 4th LED block 14 between the 3rd LED block 13 and flow-restriction 3.In addition, its result the 3rd current control unit 23 replaces flow-restriction 3 and the 4th LED block 14 is connected in parallel.In addition, be connected in parallel the 4th new current control unit 15 at flow-restriction 3, and then connect the 4th current detecting control unit 16 at the 4th current control unit 15.4th current control unit 15 limits the turn on angle to a LED block 11, the 2nd LED block 12, the 3rd LED block 13 and the 4th LED block 14.In addition, the 4th current detecting control unit 16 controls by the energising limit amount of the 4th current control unit 15 to a LED block 11, the 2nd LED block, the 3rd LED block 13 and the 4th LED block 14.Like this, by increasing LED block number, add the quantity that constant current controls, thus can carry out more careful LED interblock light switching controls.

(embodiment 5)

Further, as representing in embodiment 5, Fig. 7 by the light emitting diode drive device improved in multi-level pmultistage circuit for the purpose of wave height rate (crestfactor).Except capacitor 18, the light emitting diode drive device 500 of Fig. 7 adopts the structure roughly the same with the circuit example of Fig. 2, therefore, give identical symbol, and description is omitted for identical parts.

Light emitting diode drive device 500 shown in Fig. 7 can be avoided all extinguishing this so-called stroboscopic (strobo) phenomenon at the region light-emitting diode that pulsating voltage is low.So-called stroboscopic phenomenon, refer to that exchanging the pulsating voltage driven be near 0V, the forward voltage step-down of LED element can be put on, there is the interval of finally even extinguishing, to when will carry out throwing light on the object of the action of this extinguishing cycle synchronisation, seem that moment is static or seem the phenomenon that stops.Such as, when the middle punching die devices moved up and down used such as workshop being thrown light on by the LED light device carrying out exchanging driving, when the extinguishing cycle of cycle and the LED illumination of the diel moved up and down is synchronous once in a while, diel looks like and stops.In addition, except this situation, also exist in illumination and feel that flicker can make eye fatigue or seem to carry out artificially the problem of action etc.

In addition, as the numerical evaluation index relevant to stroboscopic phenomenon, wave height rate (wave height value) is listed.Wave height rate defines according to (peak value of light beam) ÷ (effective value of light beam).This wave height rate is more stable good value close to 1.0.When carrying out action with direct current, wave height rate is 1.0, but represents the value of more than 1 in this periodically variable situation of the application.According to JIS specification, in fluorescent lamp etc., be defined as less than 1.2.In other words, wave height rate is close to 1.0, then raw all the more stroboscopic phenomenon, can be described as the light source that versatility is high.In addition, in reality, although not relevant to LED light device special provision, think if below 1.3, actual use can be withstood.When realizing the current waveform shown in above-mentioned Fig. 3 with multi-level pmultistage circuit, wave height rate is 1.4 ~ 1.6.On the other hand, when making the current waveform shown in Fig. 4 be advanced into border, judge wave height rate to be reduced to about 1.34.

Like this, also can tackle even wave height rate about 1.3 by above-mentioned multi-level pmultistage circuit, become in the middle of the field of problem, purposes in wave height rate, can fully tackle.

At this, in order to make wave height rate further close to 1.0, be also need in the interval near 0 to light LED at electric current in the diagram.But input voltage self can decline originally in this interval, sufficient voltage cannot be provided to LED element.Therefore, need to change circuit in the structure that sufficient voltage can be provided, on this, need other the parts of element etc. additional, create circuit and form complicated, power consumption increase, circuit maximizes and manufacturing cost improves problem.

On the other hand, the light emitting diode drive device 500 involved by embodiment 5 adds capacitor 18 at the outlet side of rectification circuit 2 as shown in Figure 7 between ground wire.By being connected in parallel capacitor 18 at the outlet side of rectification circuit 2 like this, during owing to falling under voltage, electric current can be provided from capacitor 18, therefore also can power to the LED element of a LED block 11 in this interval, making it light.Its result, lights, therefore, it is possible to avoid stroboscopic phenomenon all the time owing to can make the LED element of a LED block 11.According to the experiment that present inventor carries out, find, by inserting the electrolytic capacitor that electrostatic capacitance is 10 μ F, wave height rate to be suppressed about 1.2.Wherein, use the capacitor that electrostatic capacitance is less, also wave height rate can be suppressed in 1.2 levels.

General constant current circuit or be only the capacitor used in the circuit of resistance electrostatic capacitance need 100 ~ 300 μ about F.This bulky capacitor only can be realized by electrolytic capacitor in reality, becomes larger-size capacitor.When being arranged on the substrate identical with LED element by larger-size capacitor, capacitor likely hinders the luminous intensity distribution from LED element, and significantly hinders the design of compact.In addition, electrolytic capacitor has certain life-span, and this life-span is much smaller relative to the life-span of LED element, and therefore, electrolytic capacitor determines life of product, loses LED element original long-life this advantage.

In contrast, due in this multi-level pmultistage circuit of embodiment 5, electrostatic capacitance be 10 μ about F just enough, therefore, it is possible to the parts extremely grown by the life-span of film capacitor etc. are formed.The reason that can reduce electrostatic capacitance is like this, according to original in multi-level pmultistage circuit for lower input voltage time, the part of the LED element group be connected in series will be made to light this conception to form.In other words, its reason is, because to a certain extent also can driving LED element with lower voltage, so can reduce the voltage needing to be maintained by capacitor.

Like this, the light emitting diode drive device 500 of embodiment 5 relates to the LED light device exchanging and drive, and can realize good wave height rate.In addition, its life of product is not determined by capacitor, can realize the optimization of wave height rate.

(embodiment 6)

Further, Figure 19 represents the light emitting diode drive device 600 involved by embodiment 6.Light emitting diode drive device 600 shown in this figure possesses smoothing circuit 50, and this smoothing circuit 50 can not start electric discharge before the capacitor discharge that input voltage drops to regulation starts voltage.In the general region lower at pulsating voltage, light-emitting diode all extinguishes this so-called stroboscopic phenomenon, connects the smmothing capacitor to input voltage smoothingization after full-wave rectification at the outlet side of rectification circuit 2.But, need the capacity of smmothing capacitor larger.Such as, when obtaining the light source exporting 10W, the capacitor of 9.4 μ F be adopted.When using electrolytic capacitor as jumbo capacitor, durability aspect goes wrong.In addition, when being connected in parallel multiple film capacitor to make electric capacity work as smmothing capacitor 73 as shown in Figure 16, there is the problem of cost and space increase.Therefore, in the circuit of the embodiment 6 shown in Figure 19, adopt the electric charge stored in smmothing capacitor during input voltage is lower, start this structure of discharging.

Compared with forming with the circuit shown in Figure 16, above-mentioned action is described.Figure 17 represent in the circuit of Figure 16 by the input voltage waveform after capacitor smoothing.As shown in the drawing, from the rectified waveform (dotted line) after the full-wave rectification as input voltage exceedes the time point of peak value, the electric discharge of smmothing capacitor starts naturally.Its result, interdischarge interval is elongated as shown by the solid line, needs jumbo capacitor.In addition, also requirement to withstand the height of crest voltage withstand voltage.In order to the LED block of this multilevel hierarchy making Figure 16 is lighted all the time, namely in order to also not make a LED block 11 extinguish in the region that input voltage is lower, the minimum forward voltage of LED block minimum to the minimum voltage that LED is lighted, i.e. forward voltage is needed (in the circuit example of Figure 16, to belong to a LED block 11, be set to 80V) voltage of more than 80V is maintained by smmothing capacitor 73, make to be not less than input voltage.Thus, Figure 18 is become like that (power consumption 9.5W, light beam 768lm, wave height rate 1.17, power factor 58%) by the beam shape lighting generation of LED block.

In contrast, by increasing the smoothing circuit 50 shown in Figure 19 at the outlet side of rectification circuit 2, can the capacity of smoothing capacitor be suppressed lower.Smoothing circuit 50 possess smoothing capacitor 51, be connected with smoothing capacitor 51 for the charge path that charges to it and the discharge path for discharging.The resistance 52 that charge path inserts by connecting between this rectification circuit 2 and smoothing capacitor 51 (+side) and electric discharge stop diode 53 to form.In addition, discharge path to be formed with transistor 55 (being FET in the example of Figure 19) and electric discharge diode 56, bypass transistor 54 (be bipolar transistor at the example of Figure 19) by discharging, electric discharge with transistor 55 and electric discharge diode 56 relative to tie point CP, with above-mentioned resistance 52 and discharge and stop diode 53 to be connected in parallel, bypass transistor 54, relative to smoothing capacitor 51 and upper note resistance 52 and the tie point CP stoped between diode 53 that discharges, is connected in parallel with smoothing capacitor 51.This bypass action of transistor 54 controlled discharge transistor 55.Such as, when input voltage is more than 80V, bypass transistor 54 is in ON, and electric discharge transistor 55 is in OFF.On the other hand, when input voltage is below 80V, bypass transistor 54 is in OFF, and electric discharge transistor 55 is in ON, thus starts electric discharge.In addition, the base terminal of bypass transistor 54 is connected to input voltage side via Zener diode and resistance.When input voltage reaches puncture voltage more than 80V, this Zener diode flows through reverse current, namely in bypass transistor 54, flows through base current, makes bypass transistor 54 be in ON.

Figure 20 represents the situation of the smoothing of the input voltage using this smoothing circuit 50.As shown in the drawing, from the lower state of input voltage to crest voltage, diode 53 is stoped to charge to smoothing capacitor 51 by the resistance 52 and electric discharge forming charge path.This resistance 52 flows through electric current sharp for relaxing when power supply is connected in smoothing capacitor 51, impulse current relaxes resistance.

Start to decline even if input voltage exceedes near crest voltage, smoothing capacitor 51 also can be discharged and stop diode 53 to stop electric discharge, can not discharge before electric discharge transistor 55 becomes ON.And, when input voltage declines further and the capacitor discharge reaching regulation starts voltage, if electric discharge transistor 55 is in ON, then the discharge path by being made up of electric discharge transistor 55 and electric discharge diode 56, starts the electric discharge of smoothing capacitor 51.During electric discharge, input voltage rises again, until exceed the forward voltage (minimum forward voltage) of the minimum LED block of forward voltage.Thus, make any one LED block (being a LED block 11 in the circuit example of Figure 19) light all the time, can stroboscopic phenomenon be suppressed.

By this smoothing circuit 50, capacitor discharge can be made to start the peak value (141V) of voltage lower than the input voltage of Figure 16, therefore, it is possible to as Figure 17 and shorten interdischarge interval as shown in Figure 20.In addition, shortening interdischarge interval contributes to the electrostatic capacitance needed for reduction, therefore can cut down the capacity of smoothing capacitor, can use the capacitor that the capacity such as film capacitor are little, and required number can be cut down thus reduce the space that occupies of capacitor, contributing to the miniaturization of device.

Capacitor discharge starts voltage sets must be identical with minimum forward voltage or higher than this voltage.Thus, during being configured to eliminate the extinguishing of LED block, there iing the LED block of any one to light all the time, thus can stroboscopic phenomenon be reduced.In the circuit example of Figure 19, setting capacitor discharge starts voltage, make as shown in Figure 20, the timing that smmothing capacitor starts to discharge is not and then after crest voltage, but input voltage is lower than the time point lighting required voltage (80V) of a LED block.In addition, it is such that the beam shape of the LED obtained thus becomes Figure 21, even if create the region (part in Figure 21, trough between) of a part of voltage lower than 80V, but owing to being can confirm between the short-term of pole can eliminate stroboscopic phenomenon in visual identity.Further, obtain power consumption 9.5W (LED power 8W), power-efficient 84%, power factor 82%, average light beam 745lm, luminous efficiency 78lm/W, LED utilance 55%, wave height rate 1.23, the light beam of degree roughly the same with Figure 16.Although further, wave height rate is a little less than the example of Figure 16, the capacity of smmothing capacitor required during circuit is formed can be realized by the half of Figure 16, has superiority in manufacturing cost, installation space etc.

(lighting device)

Because light emitting diode drive device this above possesses LED element, by by LED element and drive circuitry arrangement thereof at same circuit board, thus lighting device that accessible home-use AC power make it light or ligthing paraphernalia can be used as.

Above, various execution mode of the present invention is illustrated, but the present invention is not limited to particular implementation disclosed herein, these execution modes are only used for the simple illustration that technological thought of the present invention is described, should be understood to scope of the present invention to be to those skilled in the art not limited thereto, various change can be carried out in the invention scope of the claim defined added.

Utilizability in industry

The lighting control method of light emitting diode drive device of the present invention and light-emitting diode can suitably be applied to lighting device, light-emitting diode display, laser writer etc.The present invention is particularly suitable for the driving of power LED and semiconductor laser.

Symbol description:

100,200,300,400,500,600 ... light emitting diode drive device

1 ... LED block group

2 ... rectification circuit

3 ... flow-restriction

3A, 3B ... LED current-limiting resistance

4 ... current detecting unit

4A ... LED current detects resistance

4B ... first LED current detects resistance

4C ... second LED current detects resistance

4D ... 3rd LED current detects resistance

11 ... one LED block

12 ... 2nd LED block

13 ... 3rd LED block

14 ... 4th LED block

15 ... 4th current control unit

16 ... 4th current detecting control unit

17 ... protective resistance

18 ... capacitor

19 ... by-pass capacitor

21 ... first current control unit

21A, 21B, 21C ... first LED current controls transistor

22 ... second current control unit

22A, 22B, 22C ... second LED current controls transistor

23 ... 3rd current control unit

23A, 23B, 23C ... 3rd LED current controls transistor

24 ... first grid protection Zener diode

25 ... second grid protection Zener diode

26 ... 3rd gate protection Zener diode

27 ... first grid resistance

28 ... second grid resistance

29 ... 3rd resistance

31 ... first current detecting control unit

31A, 31B ... first current detecting transistor

32 ... second current detecting control unit

32A, 32B ... second current detecting transistor

33 ... 3rd current detecting control unit

33A, 33B ... 3rd current detecting transistor

34 ... second base bleederresistance

35 ... 3rd base bleederresistance

36,36B ... the first transistor load resistance

37,37B ... transistor seconds load resistance

38,38B ... third transistor load resistance

41,41B ... first base resistance

42,42B ... second base resistance

43,43B ... 3rd base resistance

50 ... smoothing circuit

51 ... smoothing capacitor

52 ... resistance

53 ... electric discharge stops diode

54 ... bypass transistor

55 ... electric discharge transistor

56 ... electric discharge diode

61,62,63,64,65,66 ... LED block

67 ... switching controlling part

71 ... AC power

72 ... bridge circuit

73 ... smmothing capacitor

74 ... drive circuit

75 ... LED group

81 ... AC power

82 ... bridge circuit

84 ... constant current circuit

85 ... LED group

86 ... feedback resistance

87 ... current detecting transistor

88 ... current control transistor

89 ... current sense resistor

91,92,93 ... LED block

94 ... Zener diode

95 ... resistance

AP ... AC power

BP1 ... first bypass path

BP2 ... second bypass path

BP3 ... 3rd bypass path

Claims (9)

1. a light emitting diode drive device, it possesses:

Rectification circuit (2), it can be connected with AC power, for obtaining the pulsating voltage carrying out after rectification to the alternating voltage of this AC power;

A LED block (11) that be connected in series with the outlet side of described rectification circuit (2), that be made up of multiple light-emitting diode, the 2nd LED block (12) be made up of multiple light-emitting diode and the 3rd LED block (13) be made up of multiple light-emitting diode;

First switch unit, it is based on the turn on angle of a described LED block (11), switches and makes described 2nd LED block (12) become the ON/OFF of first bypass path (BP1) of bypass; With

Second switch unit, it is based on the turn on angle of described 2nd LED block (12), switches and makes described 3rd LED block (13) become the ON/OFF of second bypass path (BP2) of bypass,

When the turn on angle of a described LED block (11) is higher than predetermined fiducial value, described first bypass path (BP1) is switched to OFF, then when the turn on angle of described 2nd LED block (12) is higher than predetermined fiducial value, described second bypass path (BP2) is switched to OFF, and when the turn on angle of described 2nd LED block (12) is below predetermined fiducial value, described second bypass path (BP2) is switched to ON, then when the turn on angle of a described LED block (11) is below predetermined fiducial value, described first bypass path (BP1) is switched to ON, thus allow a small amount of LED light at current value hour, and allow more LED light when current value is large.

2. light emitting diode drive device according to claim 1, is characterized in that,

Described first switch unit has:

First current control unit (21), itself and described 2nd LED block (12) are connected in parallel, for the turn on angle of restriction to a described LED block (11);

First current detecting control unit (31), it is for controlling by the energising limit amount of described first current control unit (21) to a described LED block (11); With

First current detecting unit (4B), itself and a described LED block (11) are connected in series, and detect the turn on angle of a described LED block (11),

Described second switch unit has:

Second current control unit (22), itself and described 3rd LED block (13) are connected in parallel, for limiting the turn on angle to a described LED block (11) and described 2nd LED block (12);

Second current detecting control unit (32), it is for controlling by the energising limit amount of described second current control unit (22) to a described LED block (11) and the 2nd LED block (12); With

Second current detecting unit (4C), itself and described 2nd LED block (12) are connected in series, and detect the turn on angle of described 2nd LED block (12).

3. light emitting diode drive device according to claim 2, is characterized in that,

Described first current detecting unit (4B) and the second current detecting unit (4C) are shared.

4. a light emitting diode drive device, it possesses:

Rectification circuit (2), it can be connected with AC power, for obtaining the pulsating voltage carrying out after rectification to the alternating voltage of this AC power;

One LED block (11), its multiple light-emitting diodes be connected in series by the outlet side with described rectification circuit (2) are formed;

2nd LED block (12), it is made up of the multiple light-emitting diodes be connected in series with a described LED block (11);

3rd LED block (13), it is made up of the multiple light-emitting diodes be connected in series with described 2nd LED block (12);

Flow-restriction (3), itself and described 3rd LED block (13) are connected in series;

First current control unit (21), itself and described 2nd LED block (12) are connected in parallel, for the turn on angle of restriction to a described LED block (11);

Second current control unit (22), itself and described 3rd LED block (13) are connected in parallel, for limiting the turn on angle to a described LED block (11) and described 2nd LED block (12);

3rd current control unit (23), itself and described flow-restriction (3) are connected in parallel, for the turn on angle of restriction to a described LED block (11), the 2nd LED block (12) and described 3rd LED block (13);

First current detecting control unit (31), it is for controlling by the energising limit amount of described first current control unit (21) to a described LED block (11);

Second current detecting control unit (32), it is for controlling by the energising limit amount of described second current control unit (22) to a described LED block (11) and the 2nd LED block (12); With

3rd current detecting control unit (33), it is for controlling by the energising limit amount of described 3rd current control unit (23) to a described LED block (11), the 2nd LED block (12) and the 3rd LED block (13)

When the turn on angle of a described LED block (11) is higher than predetermined fiducial value, described first current control unit (21) is switched to OFF, when the turn on angle of described 2nd LED block (12) is higher than predetermined fiducial value, described second current control unit (22) is switched to OFF, when the turn on angle of described 3rd LED block (13) is higher than predetermined fiducial value, described 3rd current control unit (23) is switched to OFF

When the turn on angle of described 3rd LED block (13) is below predetermined fiducial value, described 3rd current control unit (23) is switched to ON, when the turn on angle of described 2nd LED block (12) is below predetermined fiducial value, described second current control unit (22) is switched to ON, when the turn on angle of a described LED block (11) is below predetermined fiducial value, described first current control unit (21) is switched to ON, thus allow a small amount of LED light at current value hour, and more LED is allowed to light when current value is large.

5. light emitting diode drive device according to claim 4, is characterized in that,

By the energising limit amount of described first current control unit (21) to a described LED block (11), be less than by the energising limit amount of described second current control unit (22) to a described LED block (11) and the 2nd LED block (12)

By the energising limit amount of described second current control unit (22) to a described LED block (11) and the 2nd LED block (12), be less than by the energising limit amount of described 3rd current control unit (23) to a described LED block (11), the 2nd LED block (12) and the 3rd LED block (13).

6. the light emitting diode drive device according to claim 4 or 5, is characterized in that,

Described light emitting diode drive device also possesses in described flow-restriction (3) and the current detecting unit be connected between ground wire (4),

Described first current detecting control unit (31), the second current detecting control unit (32), the 3rd current detecting control unit (33), based on the turn on angle of described current detecting unit (4), limit the turn on angle to a described LED block (11), the 2nd LED block (12), the 3rd LED block (13) respectively.

7. the light emitting diode drive device according to any one of claim 1 to 5, is characterized in that,

Described light emitting diode drive device also possesses at the outlet side of described rectification circuit (2) and the capacitor be connected between ground wire.

8. a lighting control method for light-emitting diode, it comprises the steps:

Acquisition carries out the pulsating voltage after rectification to AC power;

This pulsating voltage is put on mutually be connected in series, be one another in series multiple light-emitting diode the LED block (11), the 2nd LED block (12) and the 3rd LED block (13) that connect;

Can switch and to be connected in parallel with described 2nd LED block (12) thus to make the 2nd LED block (12) become first current control unit (21) of the ON/OFF of first bypass path (BP1) of bypass, based on the turn on angle of a described LED block (11), when this turn on angle is below setting, the first bypass path (BP1) is switched to ON, when this turn on angle exceedes setting, the first bypass path (BP1) is switched to OFF; And

Under the state that described first bypass path (BP1) is switched to OFF thus described 2nd LED block (12) is energized, can switch and to be connected in parallel with described 3rd LED block (13) thus to make the 3rd LED block (13) become second current control unit (22) of the ON/OFF of second bypass path (BP2) of bypass, based on the turn on angle of described 2nd LED block (12), when this turn on angle is below setting, the second bypass path (BP2) is switched to ON, when this turn on angle exceedes setting, the second bypass path (BP2) is switched to OFF.

9. the lighting control method of light-emitting diode according to claim 8, also possesses following steps:

Under the state that described second bypass path (BP2) is switched to OFF thus described 3rd LED block (13) is energized, can switch and to be connected in parallel with the flow-restriction (3) being connected in series in described 3rd LED block (13) thus to make this flow-restriction (3) become the 3rd current control unit (23) of the ON/OFF of the 3rd bypass path (BP3) of bypass, based on the turn on angle of described 3rd LED block (13), when this turn on angle is below setting, the 3rd bypass path (BP3) is switched to ON, when this turn on angle exceedes setting, the 3rd bypass path (BP3) is switched to OFF.