TWI552646B - Low-flicker light-emitting diode lighting device having multiple driving stages - Google Patents

Description

Light-emitting diode lighting device with multi-stage driving stage and low frequency flash

The invention relates to a light-emitting diode lighting device with a multi-stage driving stage, in particular to a light-emitting diode lighting device with a multi-stage driving stage, a large operating voltage range, high uniformity and low frequency flashing.

In a lighting application in which a rectified alternating-current (AC) voltage is directly driven, since a light emitting diode (LED) is a current driving element, the luminance of the light is proportional to the magnitude of the driving current, in order to To achieve high brightness and uniform brightness requirements, it is often necessary to use a plurality of series connected LEDs to provide sufficient light source. The greater the number of series light-emitting diodes, the higher the forward bias required to turn on the light-emitting device, and the smaller the operable voltage range of the light-emitting diode illumination device. If the number of the light-emitting diodes is too small, the light-emitting diodes may have excessive driving current when the rectified AC voltage has a maximum value, thereby affecting the reliability of the light-emitting diode.

Luminous diode illumination devices modulate luminous flux and light intensity during operation. A flicker is an uneven phenomenon in which the intensity of a light source changes with time and brightness. Whether the human eye can recognize it or not, the stroboscopic light will cause different degrees of shadow on the human body. Ringing, such as headache, vertigo, eye fatigue, restlessness, or triggering epilepsy. Therefore, there is a need for a light-emitting diode lighting device capable of increasing an operable voltage range, high reliability, and capable of reducing stroboscopic light.

The invention provides a light-emitting diode lighting device with a multi-stage driving stage, which comprises a first-stage driving phase and a second-level driving phase. The first stage driving stage comprises a first illuminating device driven by a rectified AC voltage, which provides a light source according to a first current; and a second illuminating device driven by the rectified AC voltage, according to a second a current source for providing a light source; a first current controller connected in series to the first light emitting element for adjusting the first current such that the value of the first current does not exceed a first value; a second current controller connected in series The second light-emitting element is configured to adjust the second current so that the value of the second current does not exceed a second value; a first charge storage unit is connected in parallel to at least the first light-emitting device for the rectification The value of the alternating voltage is not sufficient to discharge the first light emitting device to the first light emitting device to maintain the first light emitting device to be turned on; and a first path controller for conducting a third current, the first One end is coupled between the first light emitting element and the first current controller, and the second end is coupled to the second current controller. The second stage driving stage includes a third current controller connected in series to the first stage driving stage for turning on and adjusting a fourth current such that the value of the fourth current does not exceed a third value.

101~108‧‧‧Lighting diode lighting device

110‧‧‧Power supply circuit

112‧‧‧Bridge rectifier

A ₁ ~A ₂ , B ₁ ~B ₂ ‧‧‧Lighting device

CCA ₁ ~CCA ₂ , CCA ₁ '~CCA ₂ '‧‧‧First type current controller

CCB ₁ ~CCB ₂ ‧‧‧Second type current controller

CC ₃ ‧‧‧Type 3 Current Controller

CH ₁ ~CH ₄ ‧‧‧charge storage unit

UNA ₁ ~ UNA ₂ , UNA ₁ '~UNA ₂ '‧‧‧ Current detection and control unit

UNB ₁ ~UNB ₂ ‧‧‧Voltage detection and control unit

UN ₃ ‧‧‧Detection and Control Unit

D ₁ ~D ₂ ‧‧‧path controller

ST ₁ ~ST ₃ ‧‧‧Drive phase

ISA ₁ ~ ISA ₂ , ISA ₁ '~ ISA ₂ ', ISB ₁ ~ ISB ₂ , IS ₃ ‧ ‧ tunable current source

1 to 4 are schematic views of a light-emitting diode lighting device according to an embodiment of the present invention.

5 to 9 are a plurality of driving stages in the LED lighting device according to the embodiment of the present invention. Schematic diagram of the operation of the segment.

FIG. 10 is a schematic diagram showing current-time characteristics of a light-emitting device in a light-emitting diode lighting device according to an embodiment of the present invention.

Figure 11 is a schematic view showing the overall operation of the light-emitting diode lighting device in the embodiment of the present invention.

Figure 12 is a schematic diagram of the overall operation of a light-emitting diode lighting device.

13 to 16 are schematic views of a light-emitting diode lighting device according to another embodiment of the present invention.

1 to 4 are schematic views of the light-emitting diode lighting devices 101 to 104 according to an embodiment of the present invention. Each of the light-emitting diode lighting devices 101 to 104 includes a power supply circuit 110 and (N+1)-stage driving stages ST ₁ to ST _N+1 . The power supply circuit 110 can receive an AC voltage VS with a positive and negative period, and utilize a bridge rectifier 112 to convert the output voltage of the AC voltage VS in a negative period, thereby providing a rectified AC voltage V _AC to drive (N+1) The stage drive stages ST ₁ ~ST _N+1 , wherein the value of the rectified AC voltage V _AC varies periodically with time. In other embodiments, the power supply circuit 110 can receive any AC voltage VS, utilize an AC-AC voltage converter for voltage conversion, and utilize the bridge rectifier 112 to rectify the converted AC voltage VS, thus providing The rectified AC voltage V _AC is driven to drive the (N+1) stage driving stages ST ₁ to ST _N+1 , wherein the value of the rectified AC voltage V _AC varies periodically with time. It is to be noted that the structure of the power supply circuit 110 does not limit the scope of the present invention.

In the LED illumination devices 101-103, each of the first to Nth stages of the driving stages ST ₁ to ST _N includes a plurality of illumination devices, a path controller, and a first type of current controller. A second type of current controller, and M charge storage units CH ₁ -CH _M , where N is an integer greater than 1, and M is a positive integer no greater than 2N. The (N+1)th stage drive stage ST _N+1 includes a third type of current controller.

In the light emitting diode lighting apparatus 104, the first driving phase stage ST ₁ comprises a plurality of light-emitting device, and the second-stage through N-th driving stage ST ₂ ~ ST _N stages each stage comprising a plurality of driving a light emitting device, a a path controller, a first type current controller, a second type current controller, and M charge storage units CH ₁ -CH _M , where N is an integer greater than 1, and M is a positive integer not greater than 2N. The (N+1)th stage drive stage ST _N+1 includes a third type of current controller.

Each first type of current controller includes an adjustable current source and a current sense a measurement and control unit, each of the second type of current controller includes an adjustable current source and a voltage detection and control unit, and each of the third type of current controller includes an adjustable current source and a detection and control unit .

In order to clearly illustrate the present invention, the following symbols are used throughout the specification and the drawings to indicate the components of the light-emitting diode lighting devices 101-104. A ₁ ~A _N and B ₁ ~B _N represent the corresponding light-emitting devices in the driving stages ST ₁ to ST _N , respectively. D ₁ ~ D _N represent the corresponding path controllers in the driving stages ST ₁ ~ ST _N , respectively. CCA ₁ ~CCA _N represent the corresponding first type of current controllers in the driving stages ST ₁ ~ST _N , respectively. CCB ₁ ~ CCB _N represent the corresponding second type of current controllers in the driving stages ST ₁ ~ST _N , respectively. CC _N+1 represents the third type of current controller in the drive phase ST _N+1 . ISA ₁ ~ ISA _N represent the corresponding adjustable current sources in the first type of current controllers CCA ₁ ~ CCA _N , respectively. ISB ₁ ~ISB _N represent the corresponding adjustable current sources of the second type current controllers CCB ₁ ~CCB _N , respectively. IS _N+1 represents the adjustable current source in the third type of current controller CC _N+1 . UNA ₁ ~ UNA _N represent the corresponding current detection and control unit of the first type current controllers CCA ₁ ~ CCA _N respectively. UNB ₁ ~ UNB _N represent the corresponding voltage detection and control unit of the second type current controllers CCB ₁ ~ CCB _N respectively. UN _N+1 represents the detection and control unit in the (N+1)th stage of the drive phase ST _N+1 .

In order to clearly illustrate the present invention, the following symbols are used throughout the specification and the drawings to indicate the relevant current and voltage in the light-emitting diode lighting devices 101-104. V _IN1 ~ V _INN represent the voltage across the first to Nth stages of the driving stages ST ₁ to ST _N , respectively. V _AK1 ~V _AKN represent the voltage across the corresponding first type current controllers CCA ₁ ~ CCA _N , respectively. V _BK1 ~V _BKN represent the cross-pressure of the corresponding second type current controllers CCB ₁ ~CCB _N , respectively. V _CK represents the voltage across the third type of current controller CC _N+1 . I _AK1 ~I _AKN represent the current flowing through the corresponding first type current controllers CCA ₁ ~ CCA _N , respectively. I _BK1 ~I _BKN represent the current flowing through the corresponding second type current controllers CCB ₁ ~CCB _N , respectively. I _A1 ~ I _AN represent the currents flowing through the corresponding light-emitting devices A ₁ -A _N , respectively. I _B1 ~I _BN represent the currents flowing through the corresponding light-emitting devices B ₁ -B _N , respectively. I _D1 ~I _DN represent the currents flowing through the corresponding path controllers D ₁ -D _N , respectively. I _SUM1 ~I _SUMN represent the currents flowing through the corresponding driving stages ST ₁ ~ST _N , respectively. The total current flowing through the LED illumination devices 101-104 can be represented by I _SUM(N+1) .

In the first to Nth stage driving stages ST ₁ to ST _N of the LED illuminating devices 101 to 103, the current detecting and controlling units UNA ₁ to UNA _N are respectively connected in series to the corresponding illuminating units A ₁ to A _N And the corresponding adjustable current sources ISA ₁ ~ ISA _N , and the voltage detection and control unit UNB ₁ ~ UNB _N are respectively connected in series to the corresponding illuminating devices B ₁ ~ B _N and respectively connected to the corresponding adjustable current source ISB ₁ ~ ISB _N. The current detection and control unit UNA ₁ ~ UNA _N can adjust the values of the adjustable current sources ISA ₁ ~ ISA _N respectively according to the currents I _AK1 ~ I _AKN . The voltage detection and control unit UNB ₁ ~UNB _N can adjust the values of the adjustable current sources ISB ₁ ~ISB _N according to the voltages V _BK1 ~V _BKN , respectively.

In the second to Nth stage driving stages ST ₂ to ST _N of the LED illuminating device 104, the current detecting and controlling units UNA ₂ to UNA _N are respectively connected in series to the corresponding illuminating units A ₂ to A _N and phases Corresponding to the adjustable current sources ISA ₂ ~ ISA _N , the voltage detection and control units UNB ₂ ~ UNB _N are respectively connected in series to the corresponding illuminators B ₂ ~ B _N and respectively connected in parallel to the corresponding adjustable current sources ISB ₂ ~ ISB _N . The current detection and control unit UNA ₂ ~UNA _N can adjust the values of the adjustable current sources ISA ₂ ~ISA _N respectively according to the current I _AK2 ~I _AKN . The voltage detection and control unit UNB ₂ ~UNB _N can adjust the values of the adjustable current source ISB ₂ ~ISB _N according to the voltage V _BK2 ~V _BKN , respectively.

In the (N+1)th driving stage ST _N+1 of the LED illumination devices 101-104, the adjustable current source IS _{N+1 is} connected in series to the first to Nth stage driving stages ST ₁ to ST _N . In a first configuration, the detection and control unit UN _{N+1 of the} third type current controller CC _N+1 can be connected in series to the adjustable current source IS _N+1 for adjusting the adjustment according to the current I _SUMN The value of the current source IS _N+1 . In a second configuration, the detection and control unit UN _{N+1 of the} third type current controller CC _N+1 can be connected in parallel to the adjustable current source IS _N+1 for adjusting the adjustable voltage V _CK The value of the current source IS _N+1 . The embodiment shown in Figures 1 to 4 employs a first configuration, but does not limit the scope of the invention.

In the embodiment of the present invention, each of the light-emitting devices A ₁ -A _N and B ₁ -B _N may comprise one light-emitting diode, or a plurality of light-emitting diodes connected in series, in parallel or in an array. Figures 1 through 4 show an architecture using a plurality of series-connected light-emitting diodes, which may include a plurality of single-junction LEDs and a plurality of multi-interface high-voltage light-emitting diodes (multi -junction high-voltage LED), or any combination of different types of light-emitting diodes. However, the type or configuration of the light-emitting diode employed in the light-emitting devices A ₁ to A _N and B ₁ to B _N does not limit the scope of the present invention. In a particular drive phase, the dropout voltage V _DROP required to turn on a particular current controller is less than the cut-in voltage V _CUT required to turn on the corresponding illuminator. When the voltage across a particular illuminating device is greater than its cut-in voltage V _CUT , the particular illuminating device will be in an ON state; when the voltage across a particular illuminating device is less than its cut-in voltage V _CUT , the particular illuminating device will be non- The OFF state of the conduction. The value of the cut-in voltage V _CUT is related to the number and type of light-emitting diodes used in the corresponding light-emitting device, and may have different values in different applications, but does not limit the scope of the present invention.

In the embodiment of the present invention, each of the M charge storage units CH ₁ -CH _M may use a capacitor or other one or more components having similar functions. However, the kind and configuration of the charge storage units CH ₁ to CH _M do not limit the scope of the present invention.

In the embodiment of the present invention, each path controller in the path controllers D ₁ -D _N may include a diode-type, diode-connected field effect transistor (FET). A bipolar junction transistor (BJT) in the form of a diode, or one or more components having similar functions. However, the type or configuration of the path controllers D ₁ to D _M does not limit the scope of the present invention. When the path voltage of a path controller is greater than its turn-on voltage, the particular path controller is forward-biased and operates like a short-circuit element; when the cross-voltage of a path controller is not greater than its turn-on voltage This particular path controller is reverse-biased and operates like an open circuit component.

Fig. 5 to Fig. 8 are views showing the operation of the first to Nth stages of the driving stages ST ₁ to ST _{N in the} light-emitting diode lighting apparatuses 101 to 103. Since the first stage to the Nth stage driving stages ST ₁ to ST _N operate in the same manner, the first stage driving stage ST _{1 is} illustrated in FIGS. 5 to 8 , wherein the fifth type illustrates the first type of current control. Current-voltage (IV) characteristics of the CCA ₁ , Figure 6 illustrates the current-voltage characteristics of the second type of current controller CCB ₁ , and Figure 7 illustrates the operation of the first stage of the driving stage ST ₁ during different periods the equivalent circuit, and FIG. 8 illustrates a first stage of the driving current stage ST _1-- voltage characteristics. Fig. 9 is a view showing the operation of the current controller CC _{N+1 in} the (N+1)th stage of the driving stage ST _N+1 . V _DROPA , V _{DROPB ,} and V _DROPC represent the differential voltages required to turn on the first type current controller CCA ₁ , the second type current controller CCB _{1 ,} and the third type current controller CC _N+1 , respectively. V _OFFA , V _OFFB and V _ONB represent the threshold voltage of the first type current controller CCA ₁ or the second type current controller CCB ₁ for judging whether to switch the operation mode. I _SETA1 , V _SETB1 and V _SETC are constants representing the current limit values of the first type current controller CCA ₁ , the second type current controller CCB ₁ and the third type current controller CC _N+1 , respectively. The arrow R indicates the rising period of the voltage V _AK1 , V _BK1 or V _CK , and the arrow F indicates the falling period of the voltage V _AK1 , V _BK1 or V _CK .

As shown in Figure 5, when the voltage V _AK1 rises and falls during 0 < V _AK1 < V _DROPA , the first type current controller CCA _{1 is} not fully turned on, which is like a voltage control element in a linear Operating in mode, the current I _AK1 will vary with voltage V _AK1 . For example, if the first type of current controller CCA ₁ is fabricated by a metal-oxide-semiconductor (MOS) transistor, the relationship between current I _AK1 and voltage V _AK1 is related to the linearity of the MOS transistor. The current-voltage characteristics of the zone during operation.

During the rising and falling periods of the voltage V _AK1 , when V _AK1 >V _DROPA , the current I _AK1 rises to the current limit value I _{SETA1 of the} first stage driving stage ST ₁ , at which time the first type current controller CCA ₁ switches to The current mode operates like a current limiter, and the current detection and control unit UNA ₁ clamps the value of current I _AK1 to I _SETA1 . For example, if the current I _D1 becomes larger, the current detection and control unit UNA ₁ will correspondingly reduce the value of the adjustable current source ISA ₁ ; similarly, if the current I _D1 becomes smaller, the current detection and control unit UNA ₁ will correspondingly increase the value of the adjustable current source ISA ₁ . Therefore, the total current I _AK1 (= I _D1 + ISA ₁ ) flowing through the first-stage driving phase ST ₁ can be maintained at a fixed value I _SETA1 instead of changing with the voltage V _AK1 .

The current detection and control unit UNA ₁ turns on the adjustable current source ISA ₁ during the rising period of the voltage V _AK1 until the current I _D1 rises to I _SETA1 . At this time, the first type current controller CCA ₁ will be in the constant current mode. _Operates so that the current I _AK1 (=I _D1 +ISA ₁ ) can be maintained at a fixed value I _SETA1 . When the current I _D1 rises to I _SETA1 , the current detection and control unit UNA ₁ turns off the adjustable current source ISA ₁ , at which time the first type current controller CCA ₁ switches to a cut-off mode, so that the current I _AK1 follows The current I _D1 increases.

The current detection and control unit UNA ₁ turns off the adjustable current source ISA ₁ during the falling period of the voltage V _AK1 until the current I _D1 drops to I _SETA1 . At this time, the first type current controller CCA ₁ operates in the cut-off mode. So that the current I _AK1 decreases with the current I _D1 . When the current I _D1 drops to I _SETA1 , the current detection and control unit UNA ₁ will turn on the adjustable current source ISA ₁ . At this time, the first type current controller CCA ₁ will operate in the constant current mode, so that the current I _AK1 can Maintain at a fixed value of I _SETA1 .

As shown in Fig. 6, when the voltage V _BK1 rises and falls during 0 < V _BK1 < V _DROPB , the second type current controller CCB _{1 is} not fully turned on, and in this case, it is in linear mode like the voltage control element. The operation is such that the current I _BK1 varies with the voltage V _BK1 . For example, if the second type current controller CCB ₁ is fabricated in a MOS transistor, the relationship between the current I _BK1 and the voltage V _BK1 is related to the current-voltage characteristic of the MOS transistor operating in the linear region.

During the rising period of voltage V _BK1 when V _BK1 >V _DROPB , current I _BK1 rises to I _SETB1 , at which time the second type current controller CCB ₁ switches to constant current mode and operates like a current limiter , and voltage detection The measuring and control unit UNB ₁ clamps the value of the current I _BK1 at I _SETB1 .

During the rising period of the voltage V _BK1 , when V _BK1 >V _OFFB , the voltage detection and control unit UNB ₁ turns off the adjustable current source ISB ₁ , at which time the second type current controller CCB ₁ switches to the cut-off mode, ie It's like an open circuit component. During the falling period of the voltage V _BK1 when V _BK1 <V _ONB , the voltage detection and control unit UNB ₁ turns on the adjustable current source ISB ₁ , and the second type current controller CCB ₁ switches to the constant current mode. So that the current I _BK1 can be maintained at a fixed value I _SETB1 . The value of the threshold voltage V _ONB may be greater than or equal to the threshold voltage _V OFFB. In one embodiment, the present invention can provide a hysteresis-band (hysteresis band), bandwidth _{(V ONB} -V OFFB) is not zero, so the controller can prevent the second type CCB ₁ current due to voltage fluctuations too V _BK1 Switch modes of operation frequently.

As shown in the left in FIG. 7, when the first stage in the driving stage ST ₁ V1 <V _IN1 <V2 when operating within one of the first period of time, the light emitting device A ₁ will be connected in parallel to the light emitting device B _1. As shown in FIG. 7, right, when operating within one of _a first stage during the second driving V3 stage ST in V _IN1>, the light emitting device A ₁ are concatenated to the light emitting device B _1.

As shown in Fig. 8, when the voltage V _{IN1 is} still low during the rising period, the light-emitting device A ₁ , the light-emitting device B ₁ and the path controller D _{1 are} still turned off. During the rising period, the value of the voltage V _IN1 rises to a turn-on voltage V _A1 , and the turn-on voltage V _A1 is the cut-in voltage required to turn on the light-emitting device A _{1 and} the cut-in voltage required to turn on the first-type current controller CCA ₁ . In the summation, the first type of current controller CCA ₁ and the illumination device A ₁ are turned on, so that the current I _A1 gradually increases with the voltage V _IN1 until it rises to I _SETA1 . During the rising period, the value of the voltage V _IN1 rises to a turn-on voltage V _B1 , and the turn-on voltage V _B1 is the cut-in voltage required to turn on the light-emitting device B _{1 and} the cut-in voltage required to turn on the second-type current controller CCB ₁ . In the summation, the second type current controller CCB ₁ and the light-emitting device B ₁ are turned on, so that the current I _B1 gradually increases with the voltage V _IN1 until it rises to I _SETB1 . Since path controller D ₁ is still off, the value of current I _{SUM1 is the} sum of current I _A1 and current I _B1 , where current I _{A1 is} regulated by first type current controller CCA ₁ and current I _B1 is second Type current controller CCB ₁ to adjust. The turn-on voltage V _A1 and the turn-on voltage V _B1 may be the same value or different values. In other words, when the value of the voltage V _IN1 rises to the voltage V1, the current I _SUM1 starts to increase, wherein the voltage V1 is the smaller of the turn-on voltage V _A1 and the turn-on voltage V _B1 .

During the rising period, when the value of the voltage V _IN1 rises to V2 such that V _BK1 =V _OFFB , the second type current controller CCB ₁ switches to the cutoff mode, so the current I _B1 is directed to the path controller D ₁ , thereby opening the path. Controller D ₁ . At this time, current I _SUM1 and currents I _A1, I _B1 of the same value of the current, where the current I _A1 and I _B1 rests with a first current type current controller CCA ₁ is adjusted. As the current I _B1 flows through the path controller D ₁ , the current I _D1 gradually increases with the voltage V _IN1 , at which time the first type current controller CCA ₁ correspondingly lowers the value of the adjustable current source ISA ₁ , so that The total current I _{SUM1 is} still maintained at a fixed value I _SETA1 . When V _IN1 =V3, the value of the adjustable current source ISA ₁ drops to 0, and the first type current controller CCA ₁ switches to the cutoff mode, at which time the current I _SUM1 is adjusted by the next stage of the drive phase.

As shown in Figure 9, when the voltage V _CK rises and falls during 0 < V _CK1 < V _DROPC , the third type current controller CC _{N+1 is} not fully turned on, and it will be online like a voltage control element. Operating in the sexual mode, the current I _CK will vary with the voltage V _CK1 . For example, if the third type current controller CC _N+1 is fabricated in a MOS transistor, the relationship between the current I _CK1 and the voltage V _CK1 is related to the current-voltage characteristic of the MOS transistor operating in the linear region. When V _CK >V _DROPC in the rising period of voltage V _CK , current I _CK1 rises to I _SETC1 , at which time the third type current controller CC _N+1 switches to constant current mode and operates like a current limiter.

Similarly, the operation of the second to Nth stage driving stages ST ₂ to ST _{N in} the LED illumination device 104 can also be illustrated by the fifth to eighth figures, and the (N+1)th stage of the driving stage ST _{N + 1} in the current operation of the controller CC _{N + 1} is also illustrated by FIG. 9.

In the embodiment of the present invention, the charge storage units CH ₁ -CH _M may be respectively connected in parallel to one or more of the light-emitting devices A ₁ -A _N and B ₁ -B _N . The charge storage units CH ₁ ~CH _M can improve the stroboscopic illumination of the LED illumination devices 101-104, where M can be less than or equal to 2N.

In the embodiment of M=2N, each of the light-emitting devices A ₁ to A _N and B ₁ to B _N is connected in parallel to a corresponding charge storage unit. For illustrative purposes, FIG. 1 shows an embodiment in which N=2 and M=4, wherein the light-emitting diode illumination device 101 includes four light-emitting devices A ₁ to A ₂ and B ₁ to B ₂ , and is respectively connected in parallel to Charge storage unit CH ₁ ~CH ₄ . However, the number or configuration of charge storage units does not limit the scope of the invention.

In Example M <2N, the light emitting device in each light emitting device B ₁ ~ B _N are connected in parallel to corresponding one of the charge storage unit. For illustrative purposes, FIG. 2 shows an embodiment in which N=2 and M=2, wherein the light-emitting diode illumination device 102 includes four light-emitting devices A ₁ to A ₂ and B ₁ to B ₂ , wherein the light-emitting device B ₁ ~ B are respectively connected in parallel to the charge storage unit CH ₁ ~ CH ₂ . However, the number or configuration of charge storage units does not limit the scope of the invention.

In the embodiment of M<2N, the M charge storage units CH ₁ to CH _M may be connected in parallel to the light-emitting devices having the longest on-time among the light-emitting devices A ₁ to A _N and B ₁ to B _N . For the purpose of explanation, FIG. 3 shows an embodiment in which N=2 and M=2, wherein the light-emitting diode illumination device 103 includes four light-emitting devices A ₁ to A ₂ and B ₁ to B ₂ , wherein the light-emitting device A ₁ and B ₁ are respectively connected in parallel to the charge storage units CH ₁ to CH ₂ . However, the number or configuration of charge storage units does not limit the scope of the invention.

M = In Example 1 <2N, the charge storage unit CH ₁ may be connected in parallel to the light emitting device A ₁ ~ A _N B and the longest on-time multiple light emitting devices in the ₁ ~ B _N. For illustrative purposes, FIG. 4 shows an embodiment where N=2 and M=1, wherein the light-emitting diode illumination device 104 includes three light-emitting devices A ₂ and B ₁ to B ₂ , wherein the light-emitting devices B ₁ to B _{2 is} connected in parallel to the charge storage unit CH ₁ . However, the number or configuration of charge storage units does not limit the scope of the invention.

Fig. 10 is a schematic view showing the current-time characteristics of the light-emitting device in the light-emitting diode lighting devices 101 to 104 in the embodiment of the present invention. The relationship between the output current I _AC and the time of the rectified AC voltage V _AC is shown at the top of Figure 10. The middle of Figure 10 shows the current-time characteristics of the illuminator when using the first configuration, while the figure below shows the first The current-time characteristic of the illuminating device during the second configuration. In Fig. 10, the I _LED represents the current flowing through the illumination device in the first configuration, and the I _LED ' represents the current flowing through the illumination device in the second configuration. In the first configuration, a light-emitting device is connected in parallel to a corresponding charge storage unit, such as the light-emitting device A ₁ , A ₂ , B ₁ or B ₂ in the light-emitting diode lighting device 101, and the light-emitting diode illumination the light emitting device 102 B B light emitting device ₁ or B _2, the light emitting device illumination device 103 a light emitting diode ₁ or B _1, or a light emitting diode lighting device 104 ₁ or B _2. In the second configuration, a light-emitting device is not connected in parallel to any charge storage unit, such as light-emitting device A ₁ or A ₂ in light-emitting diode illumination device 102, and light-emitting device A in light-emitting diode illumination device 103. ₂ or B ₂ , or the illuminating device A ₂ in the illuminating diode device 104.

At the beginning of the rising period, the value of the rectified AC voltage V _AC is not enough to turn on the illuminating device. At this time, the illuminating device of the second configuration is maintained in the OFF state, and the illuminating device adopting the first configuration can be stored by the corresponding electric charge. The charge of the cell discharge is maintained in the ON state. The corresponding path control unit can prevent the charge storage unit from discharging to the corresponding current control unit.

When the value of the rectified AC voltage V _AC is sufficient to conduct the illuminating device during the rising period and the falling period, the illuminating devices adopting the first configuration and the second configuration are maintained in the ON state by the rectified AC voltage V _AC , and the rectification AC is performed at this time. The voltage V _AC also charges the corresponding charge storage unit.

At the end of the falling cycle, the value of the rectified AC voltage V _AC is reduced to be insufficient to conduct the illuminating device. At this time, the illuminating device of the second configuration is maintained in the OFF state, and the illuminating device adopting the first configuration can be correspondingly charged. The charge of the discharge of the storage unit is maintained in the ON state. The corresponding path control unit can prevent the charge storage unit from discharging to the corresponding current control unit.

As shown in FIG. 10, the light-emitting diode lighting device of the present invention uses charge storage The unit is such that the on-time of the illumination device using the second configuration is longer than the on-time of the illumination device using the first configuration.

11 is a schematic view showing the overall operation of the LED illumination device 103 in the embodiment of the present invention, wherein two of the four illumination devices A ₁ to A ₄ (N=M=2) are respectively connected in parallel. Corresponding charge storage units CH ₁ ~CH _{2 are} also connected in parallel to a charge storage unit CH ₁ . Fig. 12 is a view showing the overall operation of the light-emitting diode illuminating device 103 when the charge storage unit is not used. E ₁ to E ₃ represent the overall light intensity/light flux of the light-emitting diode lighting device 103 of the present invention. It should be noted that Fig. 12 is only for explaining how the present invention uses the charge storage unit to improve stroboscopic sound in Fig. 11, and is not an embodiment of the light emitting diode lighting device of the present invention.

Since the voltages V _AK1 VV _AK2 and V _BK1 VV _{BK2 are} related to the rectified AC voltage V _AC , and the value of the rectified AC voltage V _AC changes periodically with time, it is included in a cycle including time points t0 to t7. For example, the time point t0~t3 is included in the rising period of the rectified AC voltage V _AC , and the time point t4~t7 is included in the falling period of the rectified AC voltage V _AC . The following chart 1 shows the operation modes of the light-emitting devices A ₁ to A ₂ and B ₁ to B _{2 of} the present invention under the structure shown in Fig. 11, and the following chart 2 shows the light-emitting devices A ₁ to A ₂ and B of the present invention. ₁ ~ B ₂ operates in the architecture shown in Figure 12.

In Fig. 12 and Fig. 2, the value of the rectified AC voltage V _{AC at} the beginning of the rising period is not sufficient to turn on the light-emitting devices A ₁ to A ₂ and B ₁ to B ₂ . In the case where the charge storage unit is not used, the light-emitting devices A ₁ to A ₂ and B ₁ to B ₂ are maintained in the OFF state between time points t0 to t1 and t6 to t7. Between time points t1 and t6, the light-emitting devices A ₁ -A ₂ and B ₁ -B ₂ are turned on by the rectified AC voltage V _AC , so that the first-stage driving phase ST ₁ and the second-stage driving phase ST ₂ can be in the first Operates during a period or a second period. As previously explained for the left side of Figure 7, when the particular drive phase is operating during the first period, the two conducting illuminators are connected in parallel with each other (indicated by "P" in Figure 1 and Figure 2); 7 shows on the right, when the specific driving phase is operating in the second period, the two conducting light-emitting devices are connected in series with each other (indicated by "S" in Figure 1 and Figure 2). More specifically, the overall light intensity/light flux of the light-emitting diode illumination device 103 is increased in stages, and reaches E ₃ after the light-emitting devices A ₁ to A ₃ enter the ON state between time points t3 and t4.

In Fig. 11 and Fig. 1, the value of the rectified AC voltage V _{AC at} the beginning of the rising period is not enough to turn on the light-emitting devices A ₁ -A ₂ and B ₁ -B ₂ . With the charge storage unit of the present invention, the light-emitting devices A ₁ and B ₁ can be maintained in an ON state between time points t0 and t7 regardless of the magnitude of the rectified AC voltage V _AC . More specifically, when the value of the rectified AC voltage V _AC is small between the time points t0 to t1 and t6 to t7, the overall light intensity/light flux of the LED illumination device 103 can be maintained at E ₁ .

As is known in the relevant fields, the stroboscopic phenomenon has periodic changes. The definition can be defined by the amplitude, the average level, the periodic frequency, the shape, and/or the amount of change in the duty cycle of the waveform. The strobe is generally quantized using a strobe ratio (Percent Flicker) and a strobe index (Flicker Index), as shown in the following equations (1) and (2).

In formula (1), MAX represents the highest of the light-emitting diode lighting devices 101-104. The large light intensity/light flux, and MIN represents the minimum light intensity/light flux of the light-emitting diode illumination devices 101-104. In formula (2), AREA1 represents the cumulative value of light intensity/light flux over a period of time when the light intensity/light flux of the light-emitting diode illumination devices 101-104 is higher than the average value, and AREA2 represents the illumination of the light-emitting diode. The light intensity/light flux accumulation value over a period of time when the light intensity/light flux of the devices 101-104 is lower than the average value.

As shown in FIG. 11, the charge storage unit of the present invention can increase the formula (1) MIN and AREA2 in formula (2), thereby reducing the illumination of the LED illumination devices 101~104 Strobe ratio and strobe index.

13 to 16 are schematic views of the light-emitting diode lighting devices 105 to 108 according to another embodiment of the present invention. Compared with the LED lighting devices 101 to 104 shown in FIGS. 1 to 4, the LED lighting devices 105 to 108 each include a power supply circuit 110 and an (N+1)-stage driving stage ST. ₁ ~ST _N+1 , where N is a positive integer. The difference is that each of the driving stages ST ₁ to ST _N of the first to Nth stages of the LED illumination devices 105 to 107 includes a plurality of illumination devices, a path controller, and two first a type current controller, and each of the second to Nth stage driving stages ST ₂ to ST _N of the light emitting diode lighting device 108 includes a plurality of light emitting devices, a path controller, and two first types Current controller.

Each of the first type current controllers of the LED illumination devices 105-108 includes an adjustable current source and a current detection and control unit, and the current-voltage characteristics of the operation are also shown in FIG. In the first type of current controller represented by CCA ₁ ~ CCA _N , the current detecting and controlling units UNA ₁ ~ UNA _N are respectively connected in series to the corresponding illuminating devices A ₁ -A _N and the corresponding adjustable current source ISA ₁ ~ ISA _N can adjust the values of the adjustable current sources ISA ₁ ~ISA _N according to the current I _AK1 ~I _AKN respectively. In the first type of current controller represented by CCA ₁ '~CCA _N ', the current detection and control unit UNA ₁ '~UNA _N ' is connected in series to the corresponding illuminating device B ₁ ~B _N and the corresponding adjustable current The source ISA ₁ '~ISA _N ' can adjust the value of the adjustable current source ISA ₁ '~ISA _N ' according to the current I _BK1 ~I _BKN respectively.

Through the above-mentioned multi-stage driving stage architecture, the present invention can simultaneously turn on the light-emitting diode All lighting devices in the body lighting device and using one or more corresponding current controllers Elastically adjust the overall current. The present invention reduces the light intensity/light flux variation of the light-emitting diode illumination device through the above-described charge storage unit. Therefore, the present invention can increase the operable voltage range of the light-emitting diode illumination device without causing flicker or uneven light. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

105‧‧‧Lighting diode lighting device

110‧‧‧Power supply circuit

112‧‧‧Bridge rectifier

A ₁ ~A ₂ , B ₁ ~B ₂ ‧‧‧Lighting device

CCA ₁ ~CCA ₂ , CCA ₁ '~CCA ₂ '‧‧‧First type current controller

CC ₃ ‧‧‧Type 3 Current Controller

CH ₁ ~CH ₄ ‧‧‧charge storage unit

UNA ₁ ~ UNA ₂ , UNA ₁ '~UNA ₂ '‧‧‧ Current detection and control unit

UN ₃ ‧‧‧Detection and Control Unit

D ₁ ~D ₂ ‧‧‧path controller

ST ₁ ~ST ₃ ‧‧‧Drive phase

ISA ₁ ~ ISA ₂ , ISA ₁ '~ ISA ₂ ', IS ₃ ‧‧‧ adjustable current source

Claims (18)

A light-emitting diode lighting device having a multi-stage driving stage, comprising: a first-stage driving stage, comprising: a first light-emitting device driven by a rectified AC voltage, which provides a light source according to a first current a second illuminating device driven by the rectified AC voltage, which provides a light source according to a second current; a first current controller connected in series to the first illuminating device for adjusting the first current to The value of the first current does not exceed a first value; a second current controller is connected in series to the second illuminating device for adjusting the second current such that the value of the second current does not exceed a second value; a first charge storage unit coupled to the at least the first illuminating device for discharging to the first illuminating device to maintain the first illuminating device when the rectified AC voltage is insufficient to conduct the first illuminating device And a first path controller for conducting a third current, comprising: a first end coupled between the first lighting device and the first current controller; and a second end coupled Connected to a second current controller; and a second stage driving stage, comprising: a third current controller connected in series to the first stage driving stage for turning on and adjusting a fourth current to make the value of the fourth current No more than a third value. The illuminating diode lighting device of claim 1, wherein the rectifying intersection When the value of the stream voltage is sufficient to turn on the first light emitting device, the first charge storage unit stops discharging to the first light emitting device and begins to be charged by the rectified alternating voltage. The illuminating diode illuminating device of claim 1, further comprising: a second charge storage unit connected in parallel to the second illuminating device, wherein the value of the rectified AC voltage is insufficient to conduct the second illuminating The device is discharged to the second illumination device to maintain the second illumination device in conduction. The illuminating diode illuminating device of claim 1, further comprising: a third stage driving stage coupled between the rectified alternating voltage and the first stage driving stage, comprising: a third illuminating device Provided by the rectified AC voltage to provide a light source, wherein the first charge storage unit is connected in parallel to the first illuminating device and the third illuminating device, and the value of the rectified AC voltage is insufficient to conduct the first The illuminating device and the third illuminating device are discharged to the first illuminating device and the third illuminating device to maintain the first illuminating device and the third illuminating device in conduction. The illuminating diode lighting device of claim 4, wherein the first charge storage unit stops discharging to the first illuminating when the value of the rectified alternating voltage is sufficient to turn on the first illuminating device and the third illuminating device The device and the third illumination device begin to be charged by the rectified AC voltage. The illuminating diode lighting device of claim 1, wherein When the voltage of the first current controller is not greater than a first voltage in one rising period or one falling period of the rectified AC voltage, the first current controller operates in a first mode to enable the first a current varies with a voltage across the first current controller; during the rising period, when the voltage across the first current controller is greater than the first voltage but not greater than a second voltage, the first current The controller is operated in a second mode to maintain the first current at the first value; and when the voltage across the first current controller is greater than the second voltage during the rising period, the first The current controller operates in a third mode to be turned off. The illuminating diode lighting device of claim 6, wherein the first current is when the voltage across the first current controller is greater than the second voltage but not greater than a third voltage during the falling period The controller is operative in the second mode to maintain the first current at the first value; and the third voltage is greater than or equal to the second voltage. The illuminating diode illuminating device of claim 1, wherein: when the voltage of the second current controller is not greater than a fourth voltage during a rising period or a falling period of the rectified alternating voltage, the The second current controller operates in a first mode to cause the second current to change with a voltage across the second current controller; during the rising period or the falling period, the third current is not greater than the first When the value is binary, the second current controller operates in a second mode to maintain the second current at the second value; When the third current is greater than the second value during the rising period or the falling period, the second current controller operates in a third mode to be turned off. The illuminating diode illuminating device of claim 1, wherein: when the voltage of the third current controller is not greater than a sixth voltage during a rising period or a falling period of the rectifying AC voltage, the The three current controller operates in a first mode to cause the fourth current to change with a voltage across the third current controller; and during the rising period or the falling period, the third current controller When the voltage across the sixth voltage is greater than the sixth voltage, the third current controller operates in a second mode to maintain the fourth current at the third value. The illuminating diode lighting device of claim 1, wherein the first current controller comprises: a first adjustable current source for turning on a fifth current; and a first detecting and controlling unit connected in parallel The first adjustable current source is configured to adjust a value of the fifth current according to a voltage across the first current controller. The illuminating diode illuminating device of claim 1, wherein the first current controller comprises: a first adjustable current source for turning on a fifth current, comprising: a first end coupled to The first illuminating device; and a second end coupled to the second illuminating device; a first detecting and controlling unit connected in series to the first adjustable current source for The first current and the second current adjust a value of the fifth current. The illuminating diode lighting device of claim 1, wherein the second current controller comprises: a second adjustable current source for conducting a sixth current; and a second detecting and controlling unit Adjusting the value of the sixth current according to the second current or the third current, comprising: a first end coupled to the second end of the first path controller and the second adjustable current source And a second end coupled to the second illuminating device. The illuminating diode lighting device of claim 1, wherein: the first current controller comprises: a first adjustable current source for turning on a fifth current; and a first detecting and controlling unit, Parallel to the first adjustable current source for adjusting a value of the fifth current according to a voltage across the first current controller, and the second current controller comprises: a second adjustable current source for Turning on a sixth current; and a second detecting and controlling unit for adjusting the value of the sixth current according to the second current or the third current. The illuminating diode lighting device of claim 1, wherein: the first current controller comprises: a first adjustable current source for conducting a fifth current, comprising: a first end coupled to the first illumination device; and a second end coupled to the second illumination device; The first detecting and controlling unit is connected in series to the first adjustable current source for adjusting the value of the fifth current according to the first current and the second current; and the second current controller comprises: a first a second adjustable current source for conducting a sixth current; and a second detecting and controlling unit for adjusting the value of the sixth current according to the second current or the third current, comprising: a first One end coupled to the second end of the first path controller and the second adjustable current source; and a second end coupled to the second illumination device. The illuminating diode lighting device of claim 1, wherein the third current controller comprises: a third adjustable current source for turning on the fourth current; and a third detecting and controlling unit connected in series The third adjustable current source is configured to control the third adjustable current source according to the fourth current. The illuminating diode illuminating device of claim 1, wherein the path controller comprises a diode, a diode-connected field effect transistor (FET), or a A bipolar junction transistor (BJT) in the form of a diode. The illuminating diode illuminating device of claim 1, wherein: when the first path controller is closed, the first illuminating device is connected in parallel to the second illuminating device; and when the first path controller is When turned on, the first illumination device is connected in series to the second illumination device. The illuminating diode lighting device of claim 1, wherein: when the first path controller is turned off, the third current has a value of 0, and the fourth current value is the first current and the a sum of values of the second current; and when the first path controller is turned on, the first current, the second current, the third current, and the fourth current have the same value.