KR20170009455A - Lighting apparatus - Google Patents

Abstract

The present invention relates to a lighting device using a lighting emitting diode as a light source. The lighting device includes a monitoring unit for monitoring rectified voltage from entering overvoltage at a predetermined level and providing a monitoring result and a regulator for performing current limitation on a current path by the monitoring result corresponding to the rectified voltage which has entered the overvoltage.

Description

LIGHTING APPARATUS

The present invention relates to a lighting apparatus, and more particularly, to a lighting apparatus using a light emitting diode as a light source.

An illumination device is being developed to utilize a light source having a high luminous efficiency with a small amount of energy for energy saving. [0002] Recently, light emitting diodes (LEDs) have been used as typical light sources for lighting devices. Light emitting diodes have the advantage of being differentiated from other light sources in various factors such as energy consumption, lifetime and light quality.

The light emitting diode has characteristics driven by a current. Therefore, an illumination device using a light emitting diode as a light source has a problem that a lot of additional circuits for current driving are required. In order to solve the above problems, the lighting device has been developed to provide an AC power source to the light emitting diodes in an AC direct type.

The AC direct lighting device is configured to convert an AC power source to a rectified voltage and to cause the light emitting diode to emit light by current driving using a rectified voltage. The AC direct lighting system uses a rectified voltage without using an inductor and a capacitor, and thus has a good power factor. The rectified voltage means a full-wave rectified voltage of the AC voltage.

The direct lighting type illumination device includes at least one light emitting diode group, and the light emitting diode group is configured to include at least one light emitting diode and emits light corresponding to a change in the rectified voltage.

An AC direct lighting apparatus needs to ensure the normal light emission of the light emitting diode group and protect the internal circuit even when the rectified voltage is an overvoltage.

It is an object of the present invention to provide a lighting apparatus for protecting an internal circuit by restricting a current of a light emitting diode group when a rectified voltage is an overvoltage to ensure normal light emission.

An illumination device in which at least one light emitting diode group emits light using the rectified voltage of the present invention includes a driving circuit for providing a current path for light emission of the light emitting diode group and performing regulation for the current path; A monitoring unit monitoring the rectified voltage and providing monitoring results; And a regulator for limiting an amount of the current in the current path to be current-regulated by the driving circuit in accordance with the rectified voltage, which is an over-voltage higher than a predetermined level, with reference to the monitoring result.

In addition, an illumination device in which at least one light emitting diode group emits light using the rectified voltage of the present invention includes: a driving circuit for providing a current path for light emission of the light emitting diode group and performing regulation on the current path; A monitoring unit monitoring the rectified voltage and providing monitoring results; And a regulator for limiting the amount of the current in the rectification path determined by the current regulation in accordance with the change in the rectified voltage, which is an overvoltage higher than a predetermined level, with reference to the monitoring result.

In addition, the illuminating device in which at least one light emitting diode group emits light by using the rectified voltage of the present invention includes a first driving circuit for providing a current path for light emission of the light emitting diode group, ; And a second driving circuit that monitors the rectified voltage and limits the amount of current flowing through the current path in response to a change in the rectified voltage that is an overvoltage of a level that is higher than a predetermined level according to a monitoring result .

According to the present invention, when a rectifying voltage of an overvoltage is supplied to a lighting apparatus using a light emitting diode, the current of the light emitting diode group can be limited in response to the overvoltage. Therefore, the lighting apparatus according to the present invention can ensure normal light emission and protect the internal circuit from overvoltage.

1 is a block diagram showing a preferred embodiment of a lighting apparatus according to the present invention;
FIG. 2 is a detailed circuit diagram showing an example of the lighting device of FIG. 1; FIG.
3 is a block diagram showing another embodiment of the lighting apparatus of the present invention.
Fig. 4 is a detailed circuit diagram showing an example of the illumination device of Fig. 3; Fig.
5 is a detailed circuit diagram of a driving circuit;
FIG. 6 is a waveform diagram for explaining the operation of the embodiment of FIG. 3; FIG.
7 is a block diagram showing still another embodiment of the lighting apparatus of the present invention.
FIG. 8 is a detailed circuit diagram showing an example of the lighting apparatus of FIG. 7; FIG.
FIG. 9 is a waveform diagram for explaining the operation of the embodiment of FIG. 7; FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. It is to be understood that the terminology used herein is for the purpose of description and should not be interpreted as limiting the scope of the present invention.

The embodiments described in the present specification and the configurations shown in the drawings are preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention and thus various equivalents and modifications Can be.

1 and 2, an embodiment of the present invention may include a power supply unit 10, an illumination unit 20, a driving circuit 30, a monitoring unit 40, and a regulator 50.

The power supply unit 10 is configured to provide a rectified voltage Vrec, and may include an AC power source VAC and a rectifier 12 for this purpose. AC power (VAC) can be configured as a commercial AC power source and provides an AC voltage. The rectifier 12 outputs a rectified voltage Vrec obtained by full-wave rectification of an AC voltage of the AC power source VAC. The rectifier 12 may be configured to have a conventional bridge diode structure.

The rectified voltage Vrec provided by the power supply unit 10 has a ripple component corresponding to a half period of the AC voltage. In the embodiment of the present invention, the change of the rectified voltage Vrec is defined as the increase or decrease of the ripple.

The illumination unit 20 emits light corresponding to the rectified voltage Vrec and includes light emitting diodes. The light emitting diodes included in the illumination unit 20 may be divided into a plurality of light emitting diode groups. The embodiment of FIG. 1 includes an illumination unit 20 including four light emitting diode groups (LED1, LED2, LED3, LED4) . The number of light emitting diode groups can be varied according to the manufacturer's intention.

Each of the light emitting diode groups LED1, LED2, LED3, and LED4 may include at least one light emitting diode or a plurality of light emitting diodes connected in series, parallel, or series-parallel. The embodiment of FIGS. 1 and 2 can be exemplified as including eight light emitting diodes connected in series to each light emitting diode group (LED1, LED2, LED3, LED4).

Each light emitting diode has a light emitting voltage, and the light emitting diode groups have a light emitting voltage level proportional to the number including the light emitting diode. The light emitting diode groups connected in series have a light emitting voltage of a sum of the light emitting voltages of the light emitting diode groups.

More specifically, assuming that the light emitting voltage of each of the light emitting diode groups (LED1, LED2, LED3, LED4) connected in series is 60V, the light emitting diode group LED1 emits light at 60V and the light emitting diode groups LED1, The light emitting diode groups LED1, LED2 and LED3 emit light at 180V and the light emitting diode groups LED1, LED2, LED3 and LED4 emit light at 240V.

Herein, 60V emitted by the light emitting diode group LED1 can be defined as the light emitting voltage V1 of the light emitting diode group LED1, and 120V emitted by the light emitting diode groups LED1 and LED2 can be defined as the light emitting diode group LED2. And 180V at which the light emitting diode groups LED1, LED2 and LED3 emit light can be defined as the light emitting voltage V3 of the light emitting diode group LED3, and the light emitting diode groups LED1, LED2 , LED3, LED4) can be defined as the light emission voltage V4 of the light emitting diode group (LED4). The driving circuit 30 performs current regulation to provide a current path for sequential light emission.

More specifically, the driving circuit 30 provides a current path to the light emitting diode groups (LED1, LED2, LED3, LED4) corresponding to the light emission of the illumination unit 20 by the change of the rectified voltage Vrec, And to perform current regulation for the < / RTI >

To this end, the driving circuit 30 includes terminals C1, C2, C3 and C4 connected to the respective output terminals of the light emitting diode groups LED1, LED2, LED3 and LED4 included in the lighting unit 20, And is connected to a sensing resistor Rs for forming a current path. The voltage applied to the sensing resistor Rs is referred to as a sensing voltage, and the current flowing through the sensing resistor Rs is referred to as a sensing current. The driving circuit 30 may be fabricated as a single chip and has a sensing resistor Riset connected to the ground GND and the sensing resistor Rs.

The driving circuit 30 uses the sensing voltage of the sensing resistor Rs to provide a current path. The driving circuit 30 compares the sensing voltage corresponding to the sensing current flowing through the sensing resistor Rs with the reference voltages provided internally corresponding to the respective light emitting diode groups LED1, LED2, LED3, and LED4. The driving circuit 30 may provide a current path connecting the sensing resistor Rs and the terminals C1, C2, C3, and C4 according to the result of comparing the sensing voltage and the reference voltages, respectively.

The rectified voltage Vrec provided to the illumination unit 20 has a ripple component that is periodically increased or decreased. When the rectified voltage Vrec rises above the light emission voltage V1, the light emitting diode group LED1 emits light. When the rectified voltage Vrec rises above the light emission voltage V2, the light emitting diode groups LED1 and LED2 emit light and the rectified voltage Vrec becomes the light emission voltage V3 The light emitting diode groups LED1, LED2, and LED3 emit light. When the rectified voltage Vrec rises above the light emitting voltage V4, the light emitting diode groups LED1, LED2, LED3, and LED4 emit light.

As the rectified voltage Vrec increases, the number of light emitting diode groups that sequentially emit light increases, and when the rectified voltage Vrec decreases, the number of light emitting diode groups that sequentially emit light decreases. The driving circuit 30 provides a changed current path in response to a change in the progressive light emitting state of the illumination unit 20, and the current on the current path for successive light emission changes stepwise.

1 and 2, the monitoring unit 40 monitors whether the rectified voltage Vrec is an overvoltage, divides the input voltage for monitoring by using resistors Rm1 and Rm2 connected in series, and divides the divided voltage Monitoring results.

The overvoltage means that the rectified voltage Vrec is equal to or higher than a preset level, and the level for judging whether the rectified voltage Vrec is the overvoltage may be variously set by the manufacturer. In the embodiment of the present invention, Is set to be higher than the light emission voltage V4 of the light emitting diode (LED4). That is, the embodiment of the present invention monitors that the rectified voltage Vrec rises excessively to the overvoltage after the light emitting diode group LED4 emits light.

More specifically, the monitoring unit 40 receives the rectified voltage Vrec applied to the input terminal SO of the illumination unit 20. That is, the monitoring unit 40 receives the rectified voltage Vrec applied to the light emitting diode groups LED1 to LED4 of the illumination unit 20, and rectifies the divided voltage applied to the node between the resistors Rm1 and Rm2, As a monitoring result corresponding to the level of the voltage Vrec.

The regulator 50 is configured to perform a current limitation on the current path of the driving circuit 30 according to a monitoring result when the rectified voltage Vrec is an overvoltage. More specifically, the regulator 50 is configured to limit the sensing current of the sensing resistor Rs in response to the monitoring result corresponding to the overvoltage.

To this end, the regulator 50 includes a regulating element M1 for regulating the regulation control signal in response to the monitoring result, a regulating element M2 for limiting the sensing current flowing through the sensing resistor Rs in response to the change of the regulation control signal, . ≪ / RTI >

Here, the regulating element M1 may be composed of an NPN bipolar transistor, and the regulating element M1 may be configured such that the monitoring result, which is the divided voltage of the monitoring part 40, is applied to the base, the emitter is grounded, The constant voltage Vcc is applied through the resistor Rg1. The regulation element M2 may be constituted by an NMOS transistor and the regulation element M2 may be configured such that the collector voltage of the regulation element M1 is applied to the gate and the source is grounded and the drain is connected to the sensing resistor Rs do. The regulation element M2 is connected to the sensing resistor Rs in parallel with the resistor Rg2.

According to the above configuration, the operation of the regulation device M1 is controlled by the monitoring result applied to the base, and the voltage applied to the collector is varied according to the monitoring result. That is, the regulation device M1 changes the constant voltage Vcc applied to the collector in accordance with the monitoring result applied to the base, and as a result, the voltage applied to the gate of the regulation device M2 changes. The voltage applied to the collector of the regulation device M1, that is, the gate of the regulation device M2, can be defined as a regulation control signal.

The regulation element M2 is turned on or off in response to a change in the regulation control signal applied to the gate.

When the rectified voltage Vrec is not an overvoltage, the regulation element M1 maintains the turn-off by the application of a low voltage to the base, and the regulation element M2 applies a high level voltage to the gate due to the constant voltage Vcc It keeps turning on.

When the rectified voltage Vrec is an overvoltage, the regulation element M1 is turned on by applying a high voltage to the base, and the regulation element M2 is turned off due to the drop of the voltage of the gate.

That is, when the regulation element M2 is turned on, the current on the current path of the driving circuit 30 can normally flow to the ground through the sensing resistor Rs and the regulation element M2. However, when the regulation element M2 is turned off, the current on the current path of the driving circuit 30 can not flow through the regulation element M2. That is, the sensing current flowing through the sensing resistor Rs is limited by the resistor Rg2.

1 and 2, the monitoring unit 40 receives the rectified voltage Vrec applied to the input terminal SO of the illumination unit 20, that is, the rectified voltage Vrec applied to the light-emitting diode groups LED1 to LED4 .

The present invention is not limited thereto, and the monitoring unit 40 may be configured as another embodiment as shown in FIG. 3 and FIG. The monitoring unit 40 shown in FIGS. 3 and 4 receives the output voltage of the selected one of the output stages S1 to S4 of the at least one light emitting diode group included in the illumination unit 20, To provide a monitoring result corresponding to < / RTI > 3 and 4 illustratively illustrate that the monitoring unit 40 is configured to receive the output voltage of the output stage S3 of the light emitting diode group LED3.

3 and 4 are different in the voltage received by the monitoring unit 40, and the remaining components are the same as those in FIG. 1 and FIG. 2. Therefore, a duplicate description thereof will be omitted. Here, the resistance value and the resistance ratio of the resistors Rm1 and Rm2 included in the monitoring unit 40 may be determined according to the variable range of the input voltage.

The drive circuit 30 of Figs. 1 to 4 described above can be described with reference to Fig.

The driving circuit 30 includes a plurality of switching circuits 31, 32, 33 and 34 for providing a current path to the light emitting diode groups LED1, LED2, LED3 and LED4 and reference voltages VREF1, VREF2, VREF3 and VREF4 And a reference voltage supply unit 36 for supplying the reference voltage.

The reference voltage supply unit 36 may be implemented by providing reference voltages VREF1, VREF2, VREF3, and VREF4 at different levels according to the manufacturer's intention.

The reference voltage supply unit 36 includes a plurality of resistors serially connected in series, and a plurality of resistors connected in series are connected to a ground terminal GND to which a constant voltage is applied. The reference voltage supply unit 36 may be configured to output reference voltages VREF1, VREF2, VREF3, and VREF4 of different levels for each node between the resistors. Also, the reference voltage supply unit 36 may be configured to include independent voltage sources that provide different levels of reference voltages VREF1, VREF2, VREF3, and VREF4.

The reference voltages VREF1, VREF2, VREF3, and VREF4 at different levels have the lowest voltage level of the reference voltage VREF1, the reference voltage VREF4 has the highest voltage level, and the reference voltages VREF1, VREF2, VREF3, The voltage level can be provided to be high.

Here, the reference voltage VREF1 has a level for turning off the switching circuit 31 at the time when the light emitting diode group LED2 emits light. More specifically, the reference voltage VREF1 may be set to a level lower than the sensing voltage formed at the sensing resistor Rs at the time of light emission of the light emitting diode group LED2.

The reference voltage VREF2 has a level for turning off the switching circuit 32 at the time when the light emitting diode group LED3 emits light. More specifically, the reference voltage VREF2 may be set to a level lower than the sensing voltage formed at the sensing resistor Rs at the sequential light emission time of the light emitting diode group LED3.

The reference voltage VREF3 has a level for turning off the switching circuit 33 at the time when the light emitting diode group LED4 emits light. More specifically, the reference voltage VREF3 may be set to a level lower than the sensing voltage formed at the sensing resistor Rs at the time of light emission of the light emitting diode group LED4.

It is preferable that the reference voltage VREF4 is set such that the current flowing in the sensing resistor Rs in the upper limit level region of the rectified voltage Vrec is a predetermined constant current type.

On the other hand, the switching circuits 31, 32, 33, and 34 are commonly connected to a sensing resistor Rs that provides a sensing voltage for current regulation and current path formation.

The switching circuits 31, 32, 33 and 34 compare the sensing voltage of the sensing resistor Rs with the reference voltages VREF1, VREF2, VREF3 and VREF4 of the reference voltage generating circuit 30, Lt; / RTI >

The switching circuits 31, 32, 33, and 34 are provided with a higher level reference voltage as they are connected to the light emitting diode groups LED1, LED2, LED3, and LED4 far from the position where the rectified voltage Vrec is applied.

It is preferable that each of the switching circuits 31, 32, 33 and 34 includes comparators 38a, 38b, 38c and 38d and a switching element and the switching element is composed of NMOS transistors 39a, 39b, 39c and 39d.

The comparators 38a, 38b, 38c and 38d of the respective switching circuits 31, 32, 33 and 34 apply a reference voltage to the positive input terminal (+), a sensing voltage to the negative input terminal And a result of comparison of the sensing voltage.

The NMOS transistors 39a, 39b, 39c and 39d of the respective switching circuits 31, 32, 33 and 34 perform a switching operation in accordance with the outputs of the comparators 38a, 38b, 38c and 38d applied to the gates do. The drains of the NMOS transistors 39a, 39b, 39c and 39d and the negative input terminals (-) of the respective comparators 38a, 38b, 38c and 38d are connected in common to the current sensing resistor Rs.

The sensing resistor Rs applies the sensing voltage to the input terminals of the comparators 38a, 38b, 38c and 38d while the NMOS transistors of the switching circuits 31, 32, 33 and 34 39a, 39b, 39c, 39d.

The light emitting diode groups LED1, LED2, LED3 and LED4 sequentially emit light in response to the change of the rectified voltage Vrec in the embodiment of the lighting apparatus of the present invention and the light emitting diode groups LED1, LED2, LED3, LED4 ) May be provided through the driving circuit 30 in response to the sequential emission of light.

The operation of the embodiment of Figs. 3 to 5 according to the illumination apparatus of the present invention will be described with reference to Fig. The embodiment of FIGS. 1 and 2 differs from the embodiment of FIGS. 3 to 5 in the overvoltage section, but the remaining operations are the same. Therefore, the operation of the embodiment of Figs. 1 and 2 can be understood with reference to the operation of the embodiment of Figs.

The illumination unit 20 is supplied with a current corresponding to the rectified voltage Vrec. The currents of the light emitting diode groups LED1, LED2, LED3, and LED4 may be divided into i1, i2, i3, and i4.

The regulation element M2 of the regulator 50 maintains the turn-on state until the light emitting diode group LED3 emits light. More specifically, the output voltage of the output terminal S3 of the light emitting diode group LED3 is maintained at a low level until the light emitting diode group LED3 emits light. Therefore, the regulation element M1 of the regulator 50 maintains the turn-off so that the regulation control signal of the constant voltage (Vcc) level, that is, the high level, is applied to the gate of the regulation element M2, Maintains turn-on.

On the other hand, when the rectified voltage Vrec is in the initial state, the reference voltages VREF1, VREF2, VREF3, and VREF4 applied to the positive input terminal (+) are applied to the negative input terminals Is higher than the sensing voltage across the resistor Rs. When the rectified voltage Vrec is in the initial state as described above, the light emitting diode groups LED1, LED2, LED3, and LED4 do not emit light.

Thereafter, when the rectified voltage Vrec rises and reaches the light emission voltage V1, the light emitting diode group LED1 emits light. When the light emitting diode group LED1 of the illumination unit 20 emits light, the switching circuit 31 connected to the light emitting diode group LED1 provides a current path for light emission.

When the rectified voltage Vrec reaches the light emitting voltage V1 and the light emitting diode group LED1 emits light and a current path is formed through the switching circuit 31, a current i1 increased to a constant level is supplied to the light emitting diode group LED1.

The current i1 flows through the light emitting diode group LED1, the switching circuit 31 of the driving circuit 30 and the sensing resistor Rs and the regulation element M2 in response to the light emission of the light emitting diode group LED1 described above Flows to the path.

Thereafter, when the rectified voltage Vrec continues to rise and reaches the light emission voltage V2, the light emitting diode group LED2 emits light. When the light emitting diode group LED2 of the illumination unit 20 emits light, the switching circuit 32 connected to the light emitting diode group LED2 provides a current path for light emission.

When the rectified voltage Vrec reaches the light emission voltage V2 and the light emitting diode group LED2 emits light and a current path is formed through the switching circuit 32, the sensing voltage of the sensing resistor Rs rises. The level of the sensing voltage at this time is higher than the reference voltage VREF1. Therefore, the NMOS transistor 39a of the switching circuit 31 is turned off by the output of the comparator 38a. That is, the switching circuit 31 is turned off, and the switching circuit 32 provides a current path corresponding to the light emission of the light emitting diode group LED2. At this time, the light emitting diode group LED1 also maintains the light emitting state, and the levels of the currents i1 and i2 of the light emitting diode group LED1 and the light emitting diode group LED2 rise to a level regulated by the switching circuit 32.

Thereafter, when the rectified voltage Vrec continues to rise and reaches the light emission voltage V3, the light emitting diode group LED3 emits light. When the light emitting diode group (LED3) emits light, the switching circuit (33) connected to the light emitting diode group (LED3) provides a current path for light emission.

When the rectified voltage Vrec reaches the emission voltage V3 and the light emitting diode group LED3 sequentially emits light and the current path through the switching circuit 33 is formed, the level of the sensing voltage of the sensing resistor Rs rises. The level of the sensing voltage at this time is higher than the reference voltage VREF2. Therefore, the NMOS transistor 39b of the switching circuit 32 is turned off by the output of the comparator 38b. That is, the switching circuit 32 is turned off, and the switching circuit 33 provides a current path corresponding to the sequential light emission of the light emitting diode group LED3. At this time, the light emitting diode groups LED1 and LED2 also maintain the light emitting state, and the levels of the currents i1 to i3 of the light emitting diode groups LED1, LED2 and LED3 rise to a level regulated by the switching circuit 33 .

At this time, the monitoring unit 40 receives the output voltage V30 of the output terminal S3 of the light emitting diode group LED3 rising after the light emitting diode group LED3 emits light. The monitoring section 40 divides the output voltage of the light emitting diode group LED3 and supplies the divided voltage to the base of the regulation element M1 of the regulator 50. [ However, at this time, the voltage provided by the monitoring unit 40 maintains a level not enough to turn on the regulation element M1. The level of the voltage supplied to the regulation element Ml in the monitoring unit 40 can be adjusted by the voltage division ratio of the resistor. Therefore, the regulation element M1 of the regulator 50 maintains the turn-off so that the regulation control signal of the constant voltage (Vcc) level, that is, the high level, is applied to the gate of the regulation element M2, Maintains turn-on.

Thereafter, when the rectified voltage Vrec continues to rise and reaches the light emission voltage V4, the light emitting diode group LED4 emits light. When the light emitting diode group LED4 emits light, the switching circuit 34 connected to the light emitting diode group LED4 provides a current path for light emission.

When the rectified voltage Vrec reaches the light emission voltage V4 and the light emitting diode group LED4 sequentially emits light and the current path through the switching circuit 34 is formed, the sensing voltage of the sensing resistor Rs rises. The level of the sensing voltage at this time is higher than the reference voltage VREF3. Therefore, the NMOS transistor 39c of the switching circuit 33 is turned off by the output of the comparator 38c. That is, the switching circuit 33 is turned off, and the switching circuit 34 provides a current path corresponding to the sequential light emission of the light emitting diode group LED4. At this time, the light emitting diode groups LED1, LED2, and LED3 also maintain the light emitting state, and the levels of the currents i1 to i4 of the light emitting diode groups LED1 to LED4 rise to a level regulated by the switching circuit 34 .

When the rectified voltage Vrec rises after the light emitting diode group LED 4 emits light, it may become an overvoltage. The output voltage of the light-emitting diode group LED3 also rises corresponding to the rise of the rectified voltage Vrec.

The monitoring unit 40 receives the output voltage V30 of the output terminal S3 of the light emitting diode group LED3 rising after the light emitting diode group LED4 emits light. The monitoring section 40 divides the output voltage V30 of the light emitting diode group LED3 and supplies the divided voltage to the base of the regulation element M1 of the regulator 50. [

If the rectified voltage Vrec is an overvoltage, the voltage provided by the monitoring unit 40 may have a level at which the regulation element Ml can be turned on. Therefore, the regulation element M1 of the regulator 50 is turned on when the rectified voltage Vrec corresponds to the overvoltage, whereby the voltage of the gate of the regulation element M2 is lowered, and the regulation element M2 is turned off.

When the regulation element M2 of the regulator 50 is turned off as described above, the current on the current path of the driving circuit 30 flows through the sensing resistors Rs and Rg2, Is limited. Therefore, as shown in Fig. 5, the voltage Vrg is applied to the drain of the regulation element M2, and the current irg flows through the resistor Rg2. At this time, the amounts of the currents i1 to i4 of the light emitting diode groups LED1 to LED4 are limited corresponding to the current irg flowing to the resistor Rg2.

Thereafter, when the rectified voltage Vrec is reduced, the current limitation due to the turning off of the regulation element M2 of the regulator 50 is released and the switching circuits 34, 34 connected to the light emitting diode groups LED4, LED3, LED2, 33, 32, and 31 are sequentially turned off, and the light emitting diode groups LED4 to LED1 are sequentially extinguished.

In the embodiment of the present invention described above, when the rectified voltage Vrec is an overvoltage, the current for light emission is limited by the operation of the regulator 50. Therefore, the illumination device can suppress the abnormal light emission corresponding to the overvoltage, thereby ensuring normal light emission and protecting the internal circuit from the overvoltage.

The sensing resistor Rs is not connected to the ground terminal GND of the driving circuit 30 and the regulator 50 generates the constant voltage Vcc according to the change of the rectified voltage Vrec And controls the operation on the regulation element M2 to limit the sensing current of the sensing resistor Rs. Therefore, the embodiment of Figs. 1 to 6 keeps the amount of the current flowing through the sensing resistor Rs constant even when the rectified voltage Vrec, which is an overvoltage, changes.

The present invention can be implemented as shown in FIGS. 7 and 8. FIG.

7 and 8 have a configuration in which the sensing resistor Rs is connected to the ground terminal (GND) of the driving circuit 30. The collector of the first regulation element M1 of the regulator 50 is connected to the sensing resistor Riset of the driving circuit 30 through the resistor Rg1. With the above configuration, the regulator 50 controls the amount of current flowing through the sensing resistor Rs to change when the rectified voltage Vrec, which is an overvoltage, changes.

7 and 8 are different from the sensing resistor Rs and the regulator 50 in that the sensing resistor Rs and the regulator 50 are the same as those of FIG. 3 and FIG. 4, and the remaining components are the same. The operation of the embodiment of FIGS. 7 and 8 can be described with reference to FIG.

In the embodiments of FIGS. 7 and 8, the regulation element M2 of the regulator 50 maintains the turn-on state until the light-emitting diode group LED3 emits light, as in the embodiment of FIGS.

7 and 8, the monitoring unit 40 receives the output voltage V30 of the output terminal S3 of the light emitting diode group LED3 rising after the light emitting diode group LED4 emits light. The monitoring section 40 divides the output voltage V30 of the light emitting diode group LED3 and supplies the divided voltage to the base of the regulation element M1 of the regulator 50. [

When the rectified voltage Vrec rises after the light emitting diode group LED 4 emits light, it may become an overvoltage. The output voltage of the light-emitting diode group LED3 also rises corresponding to the rise of the rectified voltage Vrec.

If the rectified voltage Vrec is an overvoltage, the voltage provided by the monitoring unit 40 may have a level at which the regulation element Ml can be turned on. Therefore, the regulation element Ml of the regulator 50 is turned on when the rectified voltage Vrec corresponds to the overvoltage.

At this time, the voltage Vm1c applied to the gate of the regulating element M2 is changed in level corresponding to the current im1c flowing to the regulating element M1. The voltage Vm1c applied to the gate of the regulation element M2 decreases when the rectified voltage Vrec, which is an overvoltage, increases and increases when the rectified voltage Vrec, which is an overvoltage, decreases. Accordingly, the regulation element M2 limits the amount of current flowing through the sensing resistor Rs in response to the change in the voltage Vm1c applied to the gate. At this time, the voltage applied to the drain of the regulation element M2 may be represented by Vm2d.

The limited current flows through the sensing resistor Rs and the resistor Rg2 by the operation of the regulating device M2 of the regulator 50 as a result of which the sensing current of the sensing resistor Rs is limited.

As described above, the regulator 50 reduces the amount of current flowing through the driving circuit 30 when the rectified voltage Vrec, which is an overvoltage, increases, and the amount of current flowing through the driving circuit 30 when the rectified voltage Vrec, . Therefore, the waveforms of the currents i1 to i4 of the respective LED groups LED1 to LED4 have a concave curve corresponding to the rectified voltage, which is an overvoltage.

As described above, the current flowing to the light-emitting diode groups (LED1 to LED4) is limited in accordance with the rectified voltage Vrec which is the overvoltage due to the current limitation of the regulator 50. [

The embodiments described above with reference to Figs. 1 to 9 include a first driving circuit and a second driving circuit for emitting light to at least one light emitting diode group (LED1 to LED4) using a rectified voltage Vrec and for controlling light emission ≪ / RTI >

Here, the first driving circuit can be described as corresponding to the above-described driving circuit 30, and provides a current path for light emission of one or more light emitting diode groups (LED1 to LED4), and current regulation .

The second driving circuit may be described as including the monitoring unit 40 and the regulator 50. The second driving circuit may monitor the rectified voltage Vrec and may detect a change in the rectified voltage Vrec, To limit the amount of current flowing through the current path.

Here, as in the embodiment described with reference to Figs. 1 to 6, the second driving circuit includes a first current detecting circuit for detecting a current path that is current-regulated in the first driving circuit in correspondence with the rectified voltage Vrec, May be configured to limit the amount of current.

7 to 9, the second drive circuit controls the amount of current in the rectification path determined by the current regulation based on the monitoring result to a change in the rectified voltage Vrec, which is an overvoltage of a predetermined level or higher As shown in FIG.

Therefore, embodiments of the present invention can ensure normal light emission and protect the internal circuit from overvoltage in response to the change of the rectified voltage Vrec.

On the other hand, the lighting apparatus of the present invention can be implemented by including the driving circuit 30 and the current sensing means.

Here, the driving circuit 30 provides a current path for light emission of the light emitting diode groups (LED1 to LED4), and performs current regulation for the current path.

As a result of monitoring the rectified voltage Vrec provided to the illumination unit 20, the current sensing means regulates the output current of the drive circuit 30 to a first predetermined current level when the rectified voltage Vrec is in the first state. And regulates the output current of the drive circuit 30 to a second current level set to be lower than the first current level when the rectified voltage Vrec is in the second state.

Here, the first state may be determined when the rectified voltage Vrec is equal to or lower than a predetermined voltage, and the second state may be determined when the rectified voltage is equal to or higher than a predetermined voltage.

The current sensing means can be understood to include a monitoring unit 40 and a regulator 50 disclosed in the embodiments of Figs. 1, 3 and 7.

Therefore, the monitoring unit 40 monitors the rectified voltage Vrec and provides the monitoring result, and the regulator regulates the output current of the driving circuit 30 to the first predetermined current level when the rectified voltage Vrec is in the first state Regulates the output current of the drive circuit 30 to a second current level set to be lower than the first current level when the rectified voltage Vrec is in the second state.

10: power supply unit 12: rectifier
20: illumination part 30: driving circuit
40: Monitoring section 50: Regulator

Claims (19)

1. A lighting apparatus for emitting at least one light emitting diode group using a rectified voltage,
A driving circuit that provides a current path for light emission of the light emitting diode group and performs current regulation for the current path; And
A monitoring unit monitoring the rectified voltage and providing monitoring results; And
And a regulator for limiting an amount of the current in the current path to be current-regulated in the driving circuit in accordance with the rectified voltage that is an overvoltage of at least a predetermined level with reference to the monitoring result. The method according to claim 1,
Wherein the monitoring unit receives the rectified voltage applied to at least one of the light emitting diode groups and provides the monitoring result corresponding to the level of the rectified voltage. The method according to claim 1,
Wherein the monitoring unit receives the output voltage of the selected one of the output stages of the at least one light emitting diode group and provides the monitoring result corresponding to the level of the received output voltage. The method according to claim 1,
Wherein the monitoring unit divides the input voltage for monitoring and provides the divided voltage as the monitoring result. The method according to claim 1,
And a sensing resistor coupled between the driving circuit and the regulator,
Wherein the driving circuit limits the current in the current path in response to a sensing voltage that is changed by current limitation of the regulator. 6. The regulator according to claim 5,
A first regulation element for providing a regulation control signal in response to the monitoring result; And
And a second regulation element for limiting a current flowing through the sensing resistor in response to a change in the regulation control signal. The method according to claim 6,
Wherein the first regulation element uses a constant voltage and changes the constant voltage corresponding to the monitoring result to provide the regulation control signal. The method according to claim 1,
And the regulator is constituted by a current sensing load of the driving circuit. 1. A lighting apparatus for emitting at least one light emitting diode group using a rectified voltage,
A driving circuit that provides a current path for light emission of the light emitting diode group and performs current regulation for the current path; And
A monitoring unit monitoring the rectified voltage and providing monitoring results; And
And a regulator for further regulating the amount of the current in the rectification path determined by the current regulation in accordance with the change in the rectified voltage that is an overvoltage of a level higher than a predetermined level with reference to the monitoring result. 10. The method of claim 9,
Wherein the regulator is constituted by a series load for the current output from the rectification path by the driving circuit. 10. The method of claim 9,
Wherein the monitoring unit receives the rectified voltage applied to at least one of the light emitting diode groups and provides the monitoring result corresponding to the level of the rectified voltage. 10. The method of claim 9,
Wherein the monitoring unit receives the output voltage of the selected one of the output stages of the at least one light emitting diode group and provides the monitoring result corresponding to the level of the received output voltage. 10. The method of claim 9,
Wherein the monitoring unit divides the input voltage for monitoring and provides the divided voltage as the monitoring result. 10. The method of claim 9,
And a sensing resistor connected between the driving circuit and the regulator and commonly using the driving circuit and the ground,
Wherein the driving circuit performs the current regulation using a sensing voltage of the sensing resistor formed on the basis of the ground. 10. The regulator according to claim 9,
A first regulation element for providing a regulation control signal in response to the monitoring result; And
And a second regulation element for limiting a current flowing through the sensing resistor in response to a change in the regulation control signal. 16. The method of claim 15,
Wherein the second regulation element uses a current flowing through the sensing resistor and changes the current flowing to the sensing resistor in response to the monitoring result to provide the regulation control signal. 1. A lighting apparatus for emitting at least one light emitting diode group using a rectified voltage,
A driving circuit that provides a current path for light emission of the light emitting diode group and performs current regulation for the current path; And
Wherein the regulator regulates an output current of the driving circuit to a first predetermined current level when the rectified voltage is in a first state as a result of monitoring a rectified voltage provided to the illuminating unit, And a current sensing means for regulating an output current of the driving circuit to a second current level set to be equal to or lower than the first current level. 18. The method of claim 17,
Wherein the current sensing means determines the rectified voltage as the first state when the rectified voltage is equal to or less than a predetermined voltage and determines the rectified voltage as the second state when the rectified voltage is equal to or greater than the predetermined voltage. 18. The apparatus of claim 17, wherein the current sensing means comprises:
A monitoring unit monitoring the rectified voltage and providing monitoring results; And
Regulates an output current of the driving circuit to a first current level that is set in advance when the rectified voltage is in a first state and outputs the output current of the driving circuit to the first current level when the rectified voltage is in a second state, Level to a second current level set to a level lower than the first current level.

Images