JP2002016290A - Led light source device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED light source device where color control and light quantity control of an LED can be realized, using a simple circuit constitution and comfortable light adjustment can be made. SOLUTION: An LED load 1 is formed by combining plural LEDs having two or more different luminescent colors and connecting them in reverse parallel. From an AC power source part 2, AC power, having a prescribed lighting frequency, is supplied to the LED load 1 via a switching element 3 performing on/off control at a prescribed frequency and a diode 4 connected in reverse parallel. By the on/off control of the switching element 3, a load current in a forward LED row is controlled, so that the quantity of light and the luminescent color are controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED light source device using an LED as a light emitting element.

[0002]

2. Description of the Related Art In recent years, the luminous efficiency of LEDs has increased, and their application to light sources of illuminating lamps has been studied. In order to replace the current lighting lamp, a configuration that can be connected to a commercial power supply is desired. Generally, commercial power is 50-60Hz
And the voltage is also 100V to 242V. Therefore, when lighting an LED with a commercial power supply, a lighting circuit using a resistor or a reactance element as a current limiting element is used.

[0003] Further, an LED that obtains a light color close to white by combining two or more types of LEDs having different main wavelengths.
Light sources are known. Considering color rendering and efficiency,
Three combinations of red, green and blue are excellent. Since the energizing current and the optical output almost correspond, it is possible to adjust the optical output (dimming) by adjusting the current value.

In order to control the amount of light or blinking of such an LED light source, for example, as shown in Japanese Patent Application Laid-Open No. 10-144126, a large number of LEDs of different emission colors are arranged, and The current of the road is individually controlled.

[0005]

However, one switch element is required for each branch, and the control means tends to be complicated. When a resistor is used as the current limiting element, the power loss in the resistor is large.When a capacitor is used as the current limiting element, the power loss problem is solved but the current is still stable. Sex cannot be improved.

To solve this problem, Japanese Unexamined Patent Publication No. 11-67471 discloses a circuit in which two circuits each having a plurality of LEDs connected in series are connected in parallel to a smoothing capacitor of a step-up chopper circuit, and the smoothing capacitor voltage is applied to the peak of the input voltage. Higher than the value, equal to the sum of the forward voltage of the LED to reduce the harmonics of the input current and to reduce the power loss of the current limiting element to almost zero. As a result, the number of LED strings connected in series becomes considerably large.

In the case of an incandescent light bulb, as the dimming is deepened (dimmed), the operating temperature of the filament is reduced and the filament becomes reddish. It is almost the same (chromaticity) regardless of the difference. Therefore, the user feels strange. Also, from psychological research results, it is said that at high illuminance, the color temperature is high, and at low illuminance, the lower the color temperature, the more comfortable it is.

SUMMARY OF THE INVENTION An object of the present invention is to realize a color control and a light quantity control of an LED with a simple circuit configuration, and to provide a comfortable light control.
An object of the present invention is to provide an ED light source device.

[0009]

According to the first aspect of the present invention, there is provided an LED light source device comprising: an LED load formed by combining and connecting a plurality of LEDs having at least two different colors to each other in antiparallel; An AC power supply unit for supplying AC power of a predetermined lighting frequency to the load; a switch element connected in series to the LED load and controlling ON / OFF of the AC power supplied to the LED load at a predetermined control frequency;
A diode connected in antiparallel with the switch element;
It is characterized by having.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

The LED load is an LED circuit formed as an illumination lamp, and the LED emits light when the power is turned on. The LED load is an LE connected by combining a plurality of LEDs having different emission colors of at least two colors and connected in anti-parallel.
D is formed by an anti-parallel circuit. As the emission color, for example,
It is a combination of three kinds of red, green, and blue, and the combination of red, green, and blue of one LED row of the LED antiparallel circuit and the other LED
Make the combination with the column the same or different,
The number of LEDs in the ED row includes both the same or different numbers. Further, the light amount is adjusted by adjusting the light emission time of one LED row and the other LED row.

The AC power supply unit is a power supply for supplying AC power to the LED load and an adjustment unit thereof, and is, for example, a high-frequency AC power supply.

The switch element is an LED connected in anti-parallel.
One element is connected in series to the anti-parallel circuit, and turns on and off the AC power supplied to one LED row of the LED anti-parallel circuit at a predetermined control frequency. For example, a field effect transistor (FET) is used as the switch element.

The diode is connected in anti-parallel with the switch element, and supplies AC power from the AC power supply unit to the other LED row of the LED anti-parallel circuit. Therefore, AC power is supplied from the AC power supply unit to the other LED string of the LED anti-parallel circuit regardless of whether the switch element is on or off.

The switch element is controlled on and off by a control circuit to adjust the on / off duty ratio. If the switch element is on and the AC power supply is in the forward direction, a current flows through the LED string connected in the forward direction. If the switch element is off and the AC power supply is in the reverse direction, the LED on the reverse side through the diode connected in reverse parallel to the switch element
Current flows through the columns. Since the current flowing through each LED array can be varied by controlling the duty ratio, it is possible to control the amount of light and the emission color.

According to a second aspect of the present invention, in the LED light source device according to the first aspect, the lighting frequency is 10 k.
In the case of a high frequency exceeding Hz, the control frequency is lower than the lighting frequency, and when the lighting frequency is 1 kHz or less, the control frequency is higher than the lighting frequency.

When the lighting frequency of the AC power supply from the AC power supply unit is a high frequency exceeding 10 kHz, the control frequency for turning on and off the switch element controlled by the control circuit is set to 1 kHz or less, which is lower than the lighting frequency. On the other hand, when the lighting frequency of the AC power supply from the AC power supply unit is 1 kHz or less, the control frequency for turning on and off the switch element controlled by the control circuit is set to about 10 kHz, which is higher than the lighting frequency. In any case, since the current flowing through the LED array has a high frequency, the change does not visually perceive flicker, and the adjustment of the emission color and the light amount becomes smooth.

An LED light source device according to a third aspect of the present invention is an LE light source device in which one or more LEDs are connected in anti-parallel.
An LED load formed by connecting one or more D anti-parallel circuits in parallel; an AC power supply unit for supplying AC power to the LED load; and one L forming the LED anti-parallel circuit
A switch element connected in series with an ED string and controlling on / off of AC power supplied to the LED load;
And a capacitor connected in series to the anti-parallel circuit to limit the current from the AC power supply unit.

In the present invention, the LED load is an LED circuit formed as an illuminating lamp.
D emits light. LED load is one or more LE
D is formed by connecting one or two or more LED anti-parallel circuits connected in anti-parallel. As the emission color of LED,
For example, it is a combination of at least one of three kinds of red, green, and blue, and the combination of red, green, and blue of one LED row of the LED antiparallel circuit and the combination of the other LED row are the same or the same. The number of LEDs in each LED row may be the same or different.

The AC power supply is a power supply for supplying AC power to the LED load and an adjustment unit thereof, and is, for example, a single-phase AC power supply.

The switch element is an LED connected in anti-parallel.
One element is connected in series to one LED row of the anti-parallel circuit, and turns on / off AC power supplied to one LED row of the LED anti-parallel circuit. For example, a field effect transistor (FET) is used as the switch element. The capacitor is connected in series to the LED anti-parallel circuit and limits the current from the AC power supply.

When the switch element is on, a forward current flows through one LED row and a reverse current flows through the other LED row, so that an alternating current continues to flow and the LED load continues to light. On the other hand, when the switch element is turned off, current flows in the reverse direction but does not flow in the forward direction. The capacitor is charged by the reverse current, and the reverse current is cut off soon, and the LED load is turned off. When the switch element is turned on after the LED load is turned off, current flows again in the forward direction, and the LED load is turned on. That is, the on / off of one switch element can control the blinking of the LED antiparallel circuit.

According to a fourth aspect of the present invention, there is provided an LED light source device comprising: a first LED anti-parallel circuit formed by connecting a plurality of LEDs having long main wavelengths in anti-parallel; An LED load formed by connecting, in parallel, a second LED anti-parallel circuit having an LED having a main wavelength shorter than that of the LED connected in anti-parallel and having a high forward voltage;
And an AC power supply unit for supplying AC power to the load.

The LED load according to the present invention is a first LED formed by connecting a plurality of LEDs having long main wavelengths in anti-parallel.
A second anti-parallel circuit formed by connecting an anti-parallel circuit and an LED having a main wavelength shorter than that of the LED of the first LED anti-parallel circuit in anti-parallel.
LED anti-parallel circuits are connected in parallel. In this case, the forward voltage of the LED string of the second LED anti-parallel circuit is set higher than the forward voltage of the first LED anti-parallel circuit. The forward voltage of the LED string is a minimum voltage required for the LED string to operate, and is a so-called LED forward voltage.

The AC power supply section is a power supply for supplying AC power to the LED load and an adjustment section thereof, and is, for example, a single-phase AC power supply.

When an AC power is applied to the LED load from the AC power supply, the LED forward voltage of the second LED anti-parallel circuit is higher than the LED forward voltage of the first LED anti-parallel circuit, so that the The current fluctuations are large, which will reduce the emission of light with a short dominant wavelength from the second LED anti-parallel circuit relatively when the AC power supply voltage drops. Therefore, as the dimming is deepened, the light component of a short wavelength decreases, and a reddish emission color is obtained.

According to a fifth aspect of the present invention, there is provided an LED light source device comprising a first LED series circuit formed by connecting a plurality of LEDs having a long main wavelength in series, and an LED of the first LED series circuit. An LED load formed by connecting in series a short-wavelength LED and a second LED series circuit having a high forward voltage and having a high forward voltage; a DC power supply for supplying DC power to the LED load; A first current regulator that adjusts a DC current supplied to the first LED series circuit to a reference value proportional to a DC voltage from the DC power supply unit; and a DC current supplied to the second LED series circuit. And a second current regulator that adjusts the reference voltage to a reference value proportional to a value obtained by subtracting a predetermined value from the DC voltage from the DC power supply unit.

The LED load according to the present invention includes a first LED series circuit formed by connecting a plurality of LEDs having a long main wavelength in series, and an LED having a main wavelength shorter than the LEDs of the first LED series circuit. LED formed by serially connecting
It is formed by connecting a series circuit in parallel. In this case, the second
The forward voltage of the LED string of the LED series circuit of FIG.
It is set higher than the forward voltage of the D series circuit. LED
The column forward voltage is the minimum voltage required for the LED column to operate, and is a so-called LED forward voltage.

The DC power supply is a power supply for supplying DC power to the LED load, and includes a full-wave rectifier circuit for performing full-wave rectification on a single-phase AC power supply. The case where a DC power supply is used instead of the single-phase AC power supply and the full-wave rectifier circuit is also included.

The first current regulator includes a first LED
The DC current supplied to the series circuit is adjusted to be a reference value proportional to the DC voltage from the DC power supply unit,
The DC current supplied to the first LED series circuit is adjusted to a reference value obtained by simply dividing the DC voltage. On the other hand, the second regulator adjusts the DC current supplied to the second LED series circuit to a reference value proportional to a value obtained by subtracting a predetermined value from the DC voltage from the DC power supply unit. Therefore, the second L
The DC current supplied to the ED series circuit has a large variation in the LED current with respect to the DC voltage from the DC power supply unit.

As a result, the emission of light having a short main wavelength from the second LED anti-parallel circuit is relatively reduced when the DC power supply voltage decreases. Therefore, as the dimming is deepened, the light component of a short wavelength decreases, and a reddish emission color is obtained.

An LED light source device according to a sixth aspect of the present invention is formed by connecting two or more LED anti-parallel circuits in which a plurality of LEDs are connected in anti-parallel in an LED anti-parallel circuit and having different numbers of LED columns in parallel. An LED load; and an AC power supply unit for supplying AC power to the LED load.

In the present invention, the LED load is a plurality of LEDs.
Is an LED anti-parallel circuit connected in anti-parallel,
It is formed by connecting two or more LED antiparallel circuits having different numbers of ED columns in parallel. Since each LED anti-parallel circuit has a different number of LED columns, the forward voltage at which the LED columns operate differs. An impedance element or a constant current element as a current limiting element is connected in series to each LED anti-parallel circuit.

The AC power supply is a power supply for supplying AC power to the LED load and an adjustment unit thereof, and is, for example, a single-phase AC power supply.

When the AC power from the AC power supply is applied to the LED load, the forward voltage of each LED anti-parallel circuit is different, so that the instantaneous value of the input voltage of the AC power is low in the LED anti-parallel circuit having a low forward voltage. When the input voltage increases, the number of LED anti-parallel circuits through which current flows increases. Therefore, the current flowing through the entire LED load has a waveform similar to the waveform of the input voltage. Thereby, the harmonic current can be suppressed and the efficiency can be increased.

According to a seventh aspect of the present invention, there is provided an LED light source device comprising an LED load formed by connecting two or more LED series circuits having different numbers of LED columns in an LED series circuit in which a plurality of LEDs are connected in series. A DC power supply unit for supplying DC power to the LED load.

The LED load according to the present invention comprises a plurality of LEDs.
Is an LED series circuit connected in series, and the LED
It is formed by connecting two or more LED series circuits having different numbers of columns in parallel. Since each LED series circuit has a different number of LED columns, the forward voltage at which the LED columns operate differs. A constant current element is connected in series to each LED series circuit.

The DC power supply is a power supply for supplying DC power to the LED load, and includes a full-wave rectifier circuit for performing full-wave rectification on a single-phase AC power supply. The case where a DC power supply is used instead of the single-phase AC power supply and the full-wave rectifier circuit is also included.

When a DC power supply from the DC power supply is applied to the LED load, the forward voltage of each LED series circuit is different. When the magnitude of the voltage is changed, the number of LED series circuits through which current flows increases or decreases. Therefore, the LED series circuit that is turned on by changing the input voltage can be adjusted, and the light amount can be adjusted. In addition,
The current flowing in one LED series circuit is adjusted by a constant current element connected in series to each LED series circuit.

The LED light source device according to the invention of claim 8 is formed by connecting in parallel two or more LED anti-parallel circuits having different numbers of LED columns in an LED anti-parallel circuit in which a plurality of LEDs are connected in anti-parallel. An LED power supply; an AC power supply unit for supplying AC power to the LED load; and a switch element connected in series to the LED anti-parallel circuit of the LED anti-parallel circuit having a maximum number of LED columns. Features.

In the present invention, the LED load is a plurality of LEDs.
Is an LED anti-parallel circuit connected in anti-parallel,
It is formed by connecting two or more LED anti-parallel circuits having different numbers of columns in parallel. Since each LED anti-parallel circuit has a different number of LED columns, the forward voltage at which the LED columns operate differs.

The AC power supply unit is a power supply for supplying AC power to the LED load and its adjusting unit, and is, for example, a single-phase AC power supply.

The switch element is an element that is connected in series to the LED antiparallel circuit of the LED antiparallel circuit in which the number of LED columns is not the maximum, and turns on and off the AC power supplied to the LED antiparallel circuit. For example, a field effect transistor (FET) is used as the switch element.

When AC power from the AC power supply is applied to the LED load while the switch element is off, a current flows through the LED antiparallel circuit having the maximum number of LED rows. In this case, the current becomes small because the number of LED rows is the maximum and the forward voltage is large.

Next, when the switch element of the LED anti-parallel circuit having the next largest number of LED columns among the LED anti-parallel circuits is turned on, the LED anti-parallel circuit having the second largest number of LED columns having the small forward voltage is turned on. The current flows after switching. In this case, the forward voltage decreases, and the flowing current increases. Similarly, LEs with a smaller number of LED rows in sequence
D When the switch element of the anti-parallel circuit is turned on, LED
The current is sequentially switched to the LED antiparallel circuit having a small number of columns, and the current increases.

According to a ninth aspect of the present invention, there is provided an LED light source device comprising: an LED load formed by connecting in parallel two or more LED series circuits having different numbers of LED columns in an LED series circuit in which a plurality of LEDs are connected in series; A DC power supply unit for supplying DC power to the LED load; and a switch element connected in series to the LED series circuit having a maximum number of LED columns in the LED series circuit.

In the present invention, the LED load is a plurality of LEDs.
Is an LED series circuit connected in series, and is formed by connecting two or more LED series circuits having different numbers of LED columns in parallel. Since each LED series circuit has a different number of LED columns, the forward voltage at which the LED columns operate differs.

The DC power supply unit is a power supply for supplying DC power to the LED load and an adjustment unit thereof, and includes, for example, a full-wave rectifier circuit connected to a single-phase AC power supply, and a constant current regulator for adjusting and controlling the output current. Is done. Also, a case where a DC power supply is used instead of the single-phase AC power supply and the full-wave rectifier circuit is included. The constant current regulator outputs an adjustable constant current.

The switch element is an L in the LED series circuit.
This is an element that is connected in series to the LED antiparallel circuit in which the number of ED columns is not the maximum, and turns on and off the DC power supplied to the LED series circuit. For example, a field effect transistor (FET) is used as the switch element.

When the DC power from the DC power supply is applied to the LED load while the switch element is off, a current flows through the LED series circuit having the maximum number of LED rows. In this case, since the number of LED rows is the maximum and the current is constant, the amount of light becomes the largest.

Next, when the switch element of the LED series circuit having the next largest number of LED strings in the LED series circuit is turned on, the LED series circuit having the largest number of LED strings is changed to the LED series.
A current flows by switching to the LED series circuit having the next largest number of columns. In this case, since the number of LED rows is not the maximum at a constant current, the amount of light decreases. Similarly, when the switch elements of the LED series circuit with a small number of LED columns are sequentially turned on,
The current is sequentially switched to an LED series circuit having a small number of LED rows, and the light amount decreases.

[0052]

Embodiments of the present invention will be described below. FIG. 1 shows an LED according to a first embodiment of the present invention.
It is a block diagram of a light source device.

The LED load 1 is formed of an LED anti-parallel circuit in which a plurality of LEDs having at least two different colors are combined and connected in anti-parallel. In FIG. 1, two red (R) LEDs and one blue (B) LE
D shows an LED antiparallel circuit in which two green (G) LEDs and one blue (B) LED are connected in series in the reverse direction.

The LED load 1 is supplied with AC power of a predetermined lighting frequency from an AC power supply unit 2 via a switch element 3 and a diode 4 connected in anti-parallel to the switch element. The ON / OFF duty ratio of the switch element 3 is controlled by the control circuit 5 at a predetermined control frequency, and adjusts the current flowing in the forward LED array of the LED load 1.

When the switch element 3 is turned on and the AC power of the AC power supply unit 2 is in the forward direction, a current flows through the LED string connected in the forward direction. If the switch element 3 is off and the AC power supply is in the opposite direction, a current flows through the diode 4 connected in anti-parallel to the switch element 3 to the LED row on the opposite side. The current flowing through the forward LED array can be varied by controlling the duty ratio of the switch element 3, so that the amount of light and the emission color can be controlled.

FIG. 2 shows the characteristics of the load current I when the lighting frequency of the AC power supply from the AC power supply section 2 is a high frequency exceeding 10 kHz. Lighting frequency of AC power supply is 10k
In the case of a high frequency exceeding HZ, the control circuit 5 controls the switching element 3 by setting the on / off control frequency to 1 kHz or lower, which is lower than the lighting frequency.

FIG. 3 shows the characteristics of the load current I when the lighting frequency of the AC power supply from the AC power supply unit 2 is 1 kHz or less. When the lighting frequency of the AC power supply is 1 kHz or less, the control circuit 5 sets the on / off control frequency of the switch element 3 to about 10 kHz, which is higher than the lighting frequency.

As described above, when the lighting frequency is higher than 10 kHz, the control frequency of the switch element 3 is set lower than the lighting frequency, and when the lighting frequency is 1 kHz or lower, the control frequency is set higher than the lighting frequency. . As a result, the current flowing through the LED array has a high frequency, so that the change does not visually perceive flicker, and the adjustment of the emission color and the light amount becomes smooth.

Next, a second embodiment will be described. FIG.
FIG. 4 is a configuration diagram of an LED light source device according to a second embodiment of the present invention. The LED load 1 has one or more L
1 or 2 LED anti-parallel circuit with ED connected in anti-parallel
It is formed by connecting in parallel or more. FIG. 4 shows an LED load 1 in which an LED anti-parallel circuit configured by connecting an LED row having the simplest one LED in anti-parallel is connected in parallel. When a plurality of LEDs are connected to the LED array, as shown in FIG. 1, for example, three types of LEDs of red, green, and blue are combined to configure the LED load 1.

The switch element 3 is connected in series to one of the LED strings connected in anti-parallel, and is controlled by the control circuit 5 to turn on and off the AC power supplied to the LED load 1. To the LED load 1, AC power that is turned on and off by the switch element 3 is applied from the single-phase AC power supply unit 6 via the capacitor C as a current limiting element. By this on / off control, the current flowing to the LED load 1 is controlled to perform blinking control.

FIG. 5 shows an LED according to the second embodiment.
FIG. 5 is an explanatory diagram of the operation of the light source device. As shown in FIG. 5A, when the switch element 3 is turned on, the forward direction LE is set.
A forward current I1 flows through the D column, and a reverse current I2 flows through the reverse LED column. Therefore, the alternating current continues to flow and the LED load 1 continues to light.

On the other hand, when the switch element 3 is turned off,
As shown in (b), the current I2 flows in the reverse direction, but does not flow in the forward direction. The capacitor C is charged by the reverse current I2, and the reverse current I2
2, and the LED load 1 is turned off. When the switch element 3 is turned on after the LED load 1 is turned off, the current I1 flows in the forward direction again, and the LED load 1 is turned on. That is, the on / off of one switch element 3 can control the blinking of the LED antiparallel circuit.

FIG. 6 shows an LED light source device having an LED load 1 composed of two parallel LED antiparallel circuits.
The provision of the two-parallel LED anti-parallel circuit makes it possible to adjust the amount of light and the emission color of the LED load 1 by shifting the timing of blinking.

Next, a third embodiment of the present invention will be described. FIG. 7 is a configuration diagram of an LED light source device according to the third embodiment of the present invention. The LED load 1 includes a first LE formed by connecting a plurality of LEDs having long main wavelengths in anti-parallel.
D anti-parallel circuit 7 and L of this first LED anti-parallel circuit 7
A second LED anti-parallel circuit 8 formed by connecting LEDs having a shorter main wavelength than the ED in anti-parallel is connected in parallel. The LED load 1 is supplied with AC power from a single-phase AC power supply unit 6 via a capacitor C as a current limiting element.

The forward voltage (LED forward voltage) of the LED array of the second LED anti-parallel circuit 8 is set higher than the forward voltage (LED forward voltage) of the first LED anti-parallel circuit 7. Therefore, as shown in FIG.
As the input voltage of the load 1 rises, first, the first LED
The LED current I1 of the anti-parallel circuit 7 increases. That is, the first
LED anti-parallel circuit 7 is turned on to increase the amount of light.
Then, the LED current I of the second LED antiparallel circuit 8 is
2 rises, the second LED anti-parallel circuit 8 turns on, and the light amount increases. Conversely, as the power supply voltage decreases, the second LED anti-parallel circuit 8 first turns off while reducing the light amount, and then turns off the first LED anti-parallel circuit 7 while decreasing the light amount.

As described above, the LED forward voltage of the second LED antiparallel circuit 8 is
Since the LED current is higher than the ED forward voltage, the fluctuation of the LED current with respect to the power supply voltage fluctuation is large, thereby reducing the emission of light having a short main wavelength from the second LED anti-parallel circuit 8 when the AC power supply voltage is lowered. become. Therefore,
As the dimming is deepened, the light component of a short wavelength decreases, and a reddish emission color is obtained. Thus, similarly to the incandescent lamp, the emission color can be adjusted so that the light becomes reddish when dimming is deepened.

FIG. 9 is a configuration diagram of an LED light source device according to the fourth embodiment of the present invention. This fourth embodiment is different from the third embodiment shown in FIG. 7 in that a single-phase AC power supply unit 6 is replaced with a DC power supply unit 9,
The load 1 is formed by connecting in series a first LED series circuit 9 formed by connecting a plurality of LEDs having long main wavelengths in series and an LED having a main wavelength shorter than the LEDs of the first LED series circuit 10. And a second LED series circuit 11 having a high forward voltage (LED forward voltage) is connected in parallel,
DC power is supplied to the first LED series circuit 10 of the LED load 1 via the first current regulator 12, and DC power is supplied to the second LED series circuit 11 via the second current regulator 13. It is something to do.

The DC power supply section 9 rectifies the power supply voltage of the single-phase AC power supply section 6 with a rectifier 14 to obtain a DC power supply, and the DC current adjusted by the first constant current regulator 12 is supplied to the first constant current regulator 12. The DC current applied to the LED series circuit 10 and adjusted by the second constant current regulator 13 is the first L
It is applied to the ED series circuit 11.

The first current regulator 12 has a first L
The DC current supplied to the ED series circuit is adjusted so as to be a reference value proportional to the DC voltage from the DC power supply unit 9. The DC voltage from the DC power supply unit 9 is divided by resistors R1 and R2. The first LE using the divided voltage of R2 as a reference value
The current supplied to the D series circuit 10 is adjusted.

On the other hand, the second regulator 13 divides the DC voltage from the DC power supply unit 9 by the resistors R3 and R4 via the constant voltage diode 15, and uses the divided voltage of the resistor R4 as a reference value to generate a second LED. The current supplied to the series circuit 11 is adjusted. Therefore, the second LE is set to a reference value proportional to a value obtained by subtracting a predetermined value from the DC voltage from the DC power supply unit 9.
The current supplied to the D series circuit 11 is adjusted.

As a result, the emission of light having a short main wavelength from the second LED series circuit 11 is relatively reduced when the DC power supply voltage decreases. Therefore, as the dimming is deepened, the light component of a short wavelength decreases, and a reddish emission color is obtained.

FIG. 10 is a configuration diagram of an LED light source device according to a fifth embodiment of the present invention. LED load 1 is
It is formed by connecting two or more LED antiparallel circuits having different numbers of LED columns in parallel, and is connected to the single-phase AC power supply unit 6 via the current limiting element 16. AC power is supplied to the LED load 1 from a single-phase AC power supply unit 6.

In FIG. 10, the first column LED anti-parallel circuit 17
The number of LED columns in a is n1, and the second column LED anti-parallel circuit 17
b, the number of LED columns is n2, and the third column LED anti-parallel circuit 17
When the number of LED rows of c is n3 (n1)>n2> n
3) is shown.

When the AC power from the AC power supply unit 6 is applied to the LED load 1, each of the LED anti-parallel circuits 17a to 17a
7c are different, the instantaneous value of the input voltage of the AC power supply is lower than the third column LE having the lowest forward voltage.
The operation starts from the D anti-parallel circuit 17c. When the input voltage rises, the second column LED anti-parallel circuit 17b also operates, and the first column anti-parallel circuit 17a also operates.

FIG. 11 is a characteristic diagram of the load current when an AC power supply is applied to the LED load 1 to which the five parallel LED antiparallel circuits are connected. The instantaneous value of the input voltage of the AC power supply operates from the LED anti-parallel circuit having a low forward voltage, and when the input voltage increases, the LED anti-parallel circuit through which the current flows increases. Is obtained. Thereby, the harmonic current can be suppressed and the efficiency can be increased.

FIG. 12 is a configuration diagram of an LED light source device according to the sixth embodiment of the present invention. This sixth embodiment is different from the fourth embodiment shown in FIG. 10 in that a DC power supply unit 9 is used instead of the single-phase AC power supply unit 6, and L
The ED load 1 is formed by connecting two or more LED series circuits 18a to 18c having different numbers of LED columns in parallel. DC power is supplied from the DC power supply 9 to the LED load 1.

When the DC power from the DC power supply unit 9 is applied to the LED load 1, each of the LED series circuits 18a to 18
c, the third column LED series circuit 1 having a low forward voltage depending on the magnitude of the DC voltage.
8c, the second column LED series circuit 18b operates when the input voltage increases, and the first column series circuit 18a also operates.

FIG. 13 shows the characteristics of the load current when a DC voltage that increases in a ramp shape, maintains a constant value, and then decreases in a ramp shape is applied to the LED load 1 to which five parallel LED series circuits are connected. FIG. It operates from the LED series circuit having a low forward voltage as the DC voltage increases. That is, when the input voltage increases, the number of LED series circuits through which the current flows increases, so that the load current flowing through the entire LED load 1 has a waveform similar to the waveform of the input voltage. Thereby, the harmonic current can be suppressed and the efficiency can be increased.

Next, a seventh embodiment of the present invention will be described. FIG. 14 shows an LED according to a seventh embodiment of the present invention.
It is a block diagram of a light source device.

The LED load 1 is formed by connecting two or more LED series circuits 18a to 18c having different numbers of LED columns in parallel. Then, among the LED serial circuits 18a to 18c, the LED serial circuits 18b and 18c in which the number of LED columns is not the maximum.
The switch element 3 is connected in series. The switch element 3 is controlled to be turned off by the control circuit 5. Since the LED series circuits 18a to 18c have different numbers of LED columns, the forward voltages at which the LED columns operate differ.

A constant current adjusted from the DC power supply unit 9 via the constant current regulator 19 is applied to the LED load 1. Now, when the DC power from the DC power supply unit 9 is applied to the LED load 1 with the switch element 3 turned off, a current flows through the LED series circuit 18a having the maximum number of LED rows. In this case, since the number of LED rows is the maximum and the current is constant, the amount of light becomes the largest.

Next, when the switch element 3 of the LED series circuit 18b having the next largest number of LED columns among the LED series circuits 18a to 18c is turned on, the LE having the largest number of LED columns is turned on.
From the D series circuit 18a, the LED having the next largest LED row number L
The current flows by switching to the ED series circuit 18b. In this case, since the number of LED rows is not the maximum at a constant current, the amount of light decreases. Similarly, an LED series circuit 1 having a small number of LED columns
When the switch element 8c is turned on, the current is switched to the LED series circuit 18c having a small number of LED rows, and the light amount decreases.

As described above, by turning on the switch element 3, the LED series circuits having a large number of LED rows are sequentially turned to L.
Since it is possible to switch to the LED series circuit with a small number of ED rows and change the light quantity, it is possible to perform dimming by turning on and off the switch element 3.

FIG. 15 is a configuration diagram of an LED light source device according to the eighth embodiment of the present invention. This eighth embodiment is different from the seventh embodiment shown in FIG. 14 in that a single-phase AC power supply unit 6 is used instead of the DC power supply unit 9, and
As the LED load 1, a plurality of LED anti-parallel circuits 17a to
17c. The current limiting element 16 is connected to the single-phase AC power supply 6 in series.

The LED load 1 is formed by connecting two or more LED anti-parallel circuits having different numbers of LED columns in parallel.
The switch element 3 is connected in series to the LED anti-parallel circuits 17b and 17c having the maximum number of columns. The switch element 3 is controlled to be turned off by the control circuit 5.

When the AC power from the AC power supply unit 6 is applied to the LED load with the switch element 3 turned off, a current flows through the LED anti-parallel circuit 17a to which the switch element 3 is not connected. In this case, the current becomes small because the number of LED rows is the maximum and the forward voltage is large.

Next, when the switch element 3 of the LED anti-parallel circuit 17b having the next largest number of LED columns among the LED anti-parallel circuits is turned on, the current is switched to the LED anti-parallel circuit 17b and the current flows. In this case, the forward voltage decreases, and the flowing current increases. Similarly, when the switch element 3 of the LED anti-parallel circuit 17c with a small number of LED columns is turned on, the current is switched to the LED anti-parallel circuit 17c, and the current increases. Therefore, dimming becomes possible.

[0088]

As described above, according to the present invention, the power loss can be suppressed to a minimum, and the load current can be stably supplied to the LED. Further, the color control and the light quantity control of the LED can be realized with a simple circuit configuration, and a comfortable dimming can be performed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an LED light source device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram of a load current when a lighting frequency of an AC power supply from an AC power supply unit is a high frequency exceeding 10 kHz in the first embodiment of the present invention.

FIG. 3 is a characteristic diagram of a load current when a lighting frequency of an AC power supply from an AC power supply unit is 1 kHz or less according to the first embodiment of the present invention.

FIG. 4 is a configuration diagram of an LED light source device according to a second embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of the LED light source device according to the second embodiment of the present invention.

FIG. 6 shows two parallel Ls according to the second embodiment of the present invention.
The block diagram of the LED light source device which has the LED load which consists of an ED antiparallel circuit.

FIG. 7 is a configuration diagram of an LED light source device according to a third embodiment of the present invention.

FIG. 8 is a characteristic diagram of an input voltage and an LED current of the LED light source device according to the third embodiment of the present invention.

FIG. 9 is a configuration diagram of an LED light source device according to a fourth embodiment of the present invention.

FIG. 10 is a configuration diagram of an LED light source device according to a fifth embodiment of the present invention.

FIG. 11 is a characteristic diagram of a load current when an AC power supply is applied when a 5-parallel LED antiparallel circuit is connected as an LED load according to the fifth embodiment of the present invention.

FIG. 12 is a configuration diagram of an LED light source device according to a sixth embodiment of the present invention.

FIG. 13 is a characteristic diagram of a load current when a DC power supply is applied when a 5-parallel LED series circuit is connected as an LED load according to the fifth embodiment of the present invention.

FIG. 14 is a configuration diagram of an LED light source device according to a seventh embodiment of the present invention.

FIG. 15 is a configuration diagram of an LED light source device according to an eighth embodiment of the present invention.

[Signature of code] 1 ... LED load, 2 ... AC power supply, 3 ...
Switch element, 4 diode, 5 control circuit, 6 single-phase AC power supply section, 7 first LED antiparallel circuit, 8 second
LED anti-parallel circuit, 9 DC power supply unit, 10 first L
ED series circuit, 11: second LED series circuit, 12: first current regulator, 13: second current regulator, 14: rectifier, 15: constant voltage diode, 16: current limiting element, 17: LED anti-parallel Circuit, 18: LED series circuit, 19: Constant current regulator

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 30, 2000 (2006.3.3)
0)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Continued on the front page (72) Inventor Toshihiko Sasai 4-3-1 Higashi-Shinagawa, Shinagawa-ku, Tokyo Toshiba Litec Co., Ltd. (72) Inventor Yuji Takahashi 4-3-1 Higashi-Shinagawa, Shinagawa-ku, Tokyo Toshiba Litec Co., Ltd. Inside the company (72) Inventor Masahiko Kamada 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation (72) Inventor Shinichiro Matsumoto 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting Corporation (72) Inventor Hideo Kozuka 3-3-1 Higashishinagawa, Shinagawa-ku, Tokyo F-term in Toshiba Lighting & Technology Corporation (reference) 3K073 AA13 AA52 CG13 CG28 CJ17 5F041 AA11 BB13 BB24 BB25 BB34 BB34

Claims (9)

[Claims] 1. An LED formed by combining and reverse-parallel connecting a plurality of LEDs having different emission colors of at least two colors.
An ED load; an AC power supply unit for supplying an AC power of a predetermined lighting frequency to the LED load; an AC power supply unit connected in series to the LED load to perform on / off control of the AC power supplied to the LED load at a predetermined control frequency. An LED light source device comprising: a switch element; and a diode connected in antiparallel with the switch element. 2. When the lighting frequency is a high frequency exceeding 10 kHz, the control frequency is lower than the lighting frequency. When the lighting frequency is 1 kHz or less, the control frequency is higher than the lighting frequency. The LED light source device according to claim 1, wherein: 3. An LED load formed by connecting one or two or more LED anti-parallel circuits in which one or more LEDs are connected in anti-parallel; and an AC power supply unit for supplying AC power to the LED load. A switch element that is connected in series to one of the LED strings forming the LED anti-parallel circuit and controls on / off of AC power supplied to the LED load;
A capacitor that is connected in series to the LED anti-parallel circuit and limits the current from the AC power supply unit. 4. A first LED anti-parallel circuit formed by connecting a plurality of LEDs having long main wavelengths in anti-parallel,
Second LED having a higher forward voltage formed by connecting LEDs having a shorter main wavelength than the LEDs of the LED anti-parallel circuit in anti-parallel.
An LED load formed by connecting an anti-parallel circuit in parallel;
An LED power supply unit for supplying AC power to the LED load. 5. A first LED series circuit formed by connecting a plurality of LEDs having long main wavelengths in series, and said first LED series circuit.
An LED load formed by connecting in parallel an LED having a main wavelength shorter than that of the LED of the ED series circuit and a second LED series circuit having a high forward voltage;
A DC power supply unit for supplying DC power to a load;
A first adjustment is made so that the DC current supplied to the ED series circuit becomes a reference value proportional to the DC voltage from the DC power supply unit.
And a second current regulator for adjusting a DC current supplied to the second LED series circuit to a reference value proportional to a value obtained by subtracting a predetermined value from a DC voltage from the DC power supply unit. An LED light source device comprising: 6. An LE in which a plurality of LEDs are connected in anti-parallel.
An LED load formed by connecting two or more LED anti-parallel circuits having different numbers of LED columns in the D anti-parallel circuit in parallel;
And an AC power supply unit for supplying AC power to the ED load. 7. An LED in which a plurality of LEDs are connected in series
An LED light source comprising: an LED load formed by connecting two or more LED series circuits having different numbers of LED strings in a series circuit in parallel; and a DC power supply unit for supplying DC power to the LED load. apparatus. 8. An LE in which a plurality of LEDs are connected in anti-parallel.
An LED load formed by connecting two or more LED anti-parallel circuits having different numbers of LED columns in the D anti-parallel circuit in parallel;
An AC power supply for supplying AC power to an ED load;
A switch element connected in series to the LED anti-parallel circuit having the largest number of LED columns in the D anti-parallel circuit. 9. An LED in which a plurality of LEDs are connected in series
An LED load formed by connecting two or more LED series circuits having different numbers of LED columns in a series circuit in parallel; a DC power supply unit for supplying DC power to the LED load; A switch element connected in series to a non-maximum LED series circuit.