JPH08273881A - Lighting device for discharge lamp, discharge lamp lighting device, and illumination unit - Google Patents

Abstract

PURPOSE: To prevent the occurrence of the flicker of a discharge lamp even if a DC voltage contains a ripple component by detecting the value of the DC voltage at a slower response speed than a voltage stabilizing response speed in a general DC current by means of a voltage detection circuit in an inverter circuit. CONSTITUTION: A voltage detection circuit 24 is connected to a DC voltage line by means of input terminals 21. In the circuit 24, a time constant circuit 25 controlling the operation of a transistor Q3 is formed. The time constant of the circuit 25 is set so as to be slow comparing to the voltage stabilizing response speed of a general DC current power source 3 side. This time constant regulates the response speed concerning voltage-frequency conversion as an inverter circuit 6, and the oscillation frequency of the circuit 6 is also variably controlled so that the dimming level of a discharge lamp 8 is varied. Since, in the circuit 24, the time constant of the time constant circuit 25 is rather slowly controlled in the case of such operation control of the circuit 6 side, a dimming control is not allowed to be conducted at the cycle of a ripple component.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device, a discharge lamp lighting device and a lighting system for dimming and lighting a discharge lamp using a collective DC power supply.

[0002]

2. Description of the Related Art In recent years, some lighting devices for lighting a discharge lamp are provided with a dimming function in order to enhance their commercial value. There are various methods for dimming the discharge lamp, but in any case,
A dedicated dimming line for sending a dimming level signal is wired to an inverter circuit for dimming the discharge lamp. The dimming level is set for each discharge lamp (each inverter circuit) and the dimming lighting is performed.

However, when considering the facility lighting in a store or the like, since a large number of discharge lamps are handled, it is not preferable that a dedicated dimming line is required for each discharge lamp because it is wasteful on wiring and it is not preferable. The operation of the light lighting control becomes troublesome.
In particular, for dimming lighting in stores, etc., use dark light (deep dimming level) for rows on the window side that are bright due to outside light, and light dimming (shallow dimming level) for rows on the back side. Considering good points, it is troublesome to perform a dimming operation for each individual discharge lamp.

In consideration of such a point, by using a collective DC power source and outputting a DC voltage corresponding to the dimming level to the DC output line, the inverter of the discharge lamp lighting device connected to the DC output line. A lighting system has been proposed in which a DC voltage is detected in a circuit and dimming control is performed according to the DC voltage to turn on a discharge lamp. That is,
Seen from the inverter circuit side, the value of the supplied DC voltage itself includes the dimming level information. In the case of the above-mentioned store example, collective DC power supplies are prepared for the window side row, the back side row, and the middle row. According to this, it suffices to connect the discharge lamp lighting device for lighting at the same dimming level to the DC output line of the common collective DC power source, and the dedicated dimming line can be eliminated.

[0005]

However, even though the collective DC power source outputs a DC voltage, it is necessary to provide a smoothing element such as an electrolytic capacitor to smooth the AC voltage which is switched at high speed by the switching element with the smoothing element. As a result, a DC voltage is obtained, so that it must have a ripple component due to the smoothing action. Here, the value of the DC voltage output from the collective DC power supply indicates the dimming level,
If this DC voltage has a ripple component, the inverter circuit in each discharge lamp lighting device also follows this and performs voltage-frequency conversion or the like to perform dimming control. Therefore, the brightness of the dimming lighting periodically fluctuates according to the ripple component, resulting in flicker illuminating.

Therefore, the present invention is for a discharge lamp capable of performing a dimming lighting in which the flicker does not occur in the discharge lamp even if the DC voltage indicating the dimming level output from the collective DC power source includes a ripple component associated with the smoothing action. An object of the present invention is to provide a lighting device, a discharge lamp lighting device, and a lighting device or lighting system using the lighting device.

[0007]

According to another aspect of the present invention, there is provided a lighting device for a discharge lamp, wherein a value of a DC voltage indicating a dimming level supplied by a DC output line of the collective DC power supply is a constant voltage in the collective DC power supply. An inverter circuit for dimming and lighting a discharge lamp, which has a voltage detection circuit for detecting the response speed slower than the conversion response speed.

A second aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein the inverter circuit variably controls the oscillation frequency according to the value of the DC voltage indicating the dimming level. Is a high frequency inverter circuit for dimming and lighting.

According to a third aspect of the present invention, in the discharge lamp lighting device according to the second aspect, the slow response speed of the inverter circuit converts the value of the DC voltage supplied from the collective DC power supply into the oscillation frequency. Is the conversion response speed for.

The invention according to claim 4 is the invention according to claims 1 to 3.
In the lighting device for a discharge lamp according to any one of items 1, the slow response speed of the inverter circuit is included in the voltage detection circuit,
It is set by the time constant of the time constant circuit consisting of a resistor and a capacitor connected between the DC output lines. Specifically, the time constant of the time constant circuit is set to be slower, for example, 100 Hz or less, which is twice the input AC power supply frequency.

A discharge lamp lighting device according to a fifth aspect of the invention is
The discharge lamp lighting device according to any one of claims 1 to 4, and a discharge lamp that is energized by the discharge lamp lighting device.

A lighting system according to a sixth aspect of the present invention comprises a collective DC power supply which has a constant voltage converting means including a smoothing element and outputs a DC voltage indicating a dimming level to a DC output line; The discharge lamp lighting device according to claim 5, which is connected to a DC output line.

According to a seventh aspect of the present invention, there is provided a lighting system including a plurality of batch DC power supplies, each of which has a constant voltage converting means including a smoothing element and outputs a DC voltage indicating a dimming level to a DC output line. The discharge lamp lighting device according to claim 5, wherein a plurality of DC output lines of the DC power supply are connected.

In the inventions according to claims 6 and 7, the collective DC power source may be any one as long as it has a constant voltage converting means including a smoothing element and outputs a DC voltage according to a dimming level. For example, a step-up chopper method including a high-speed switching element that performs high-speed switching according to the voltage value and a step-up transformer may be configured. An electrolytic capacitor or the like is used as the smoothing element.

[0015]

According to the present invention, the voltage detection circuit in the inverter circuit detects the value of the DC voltage at a response speed slower than the constant voltage response speed of the batch DC power supply. Even if a ripple component is included in the dimming control, the dimming control of the inverter circuit does not follow the ripple component, and the flicker does not occur in the dimmed discharge lamp.

According to the second aspect of the invention, the inverter circuit is a frequency variable control type high frequency inverter circuit, and the influence of ripple components in the DC voltage used for frequency conversion is eliminated.

According to the third aspect of the invention, such a slow response speed is the conversion response speed of the voltage-frequency conversion, and even if the DC voltage from the collective DC power supply contains the ripple component, the ripple component is included in the ripple component. Since conversion processing that does not follow is performed and dimming control is performed, flicker does not occur in the discharge lamp that is dimmed.

In the invention according to claim 4, since the slow response speed is set by the time constant of the time constant circuit in the voltage detection circuit, the ripple component contained in the DC voltage by the collective DC power supply is simple in structure. The adverse effect due to is prevented.

According to the invention of claim 5, claim 1
Since the discharge lamp lighting device according to any one of 1 to 4 is used, the flicker of the discharge lamp that is dimmed and lit by the DC voltage supplied from the collective DC power supply is prevented.

In the invention of claim 6, claim 5
Since the discharge lamp lighting device described is used, even if the DC voltage supplied by the batch DC power supply contains a ripple component,
Flicker-free illumination is provided for discharge lamps that are commonly dimmed according to the value of the DC voltage.

According to the invention of claim 7, claim 5
Since the system is configured with a plurality of collective DC power supplies by using the plurality of discharge lamp lighting devices described, flicker-free dimming lighting is performed throughout the facility.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. 1 is a schematic wiring diagram showing a lighting system, FIG. 2 is a block diagram showing a collective DC power supply, and FIG. 3 is a circuit diagram showing a discharge lamp lighting device and a discharge lamp lighting device.

First, the system configuration will be described with reference to FIG. In the lighting system 1 of the present embodiment, a collective DC power supply 3 is connected to a commercial AC power supply 2, and a plurality of discharge lamp lighting devices 5a and 5b are connected to a DC output line 4 of the collective DC power supply 3. , 5c, ... Are sequentially connected in parallel. Here, the collective DC power supply 3 is connected to each of the discharge lamp lighting devices 5a, 5b, 5 via the DC output line 4.
It has a function of changing the value of the DC voltage supplied to c, ... According to the dimming level. In addition, each discharge lamp lighting device 5a,
5b, 5c, ... Inverter circuits 6a, 6b,
6c, ... Discharge lamp lighting devices 7a, 7b, 7
, and discharge lamps 8a, 8b, 8c, ..., which are energized by the discharge lamp lighting devices 7a, 7b, 7c ,. Each inverter circuit 6a, 6
are provided with a voltage detection circuit for detecting the value of the DC voltage supplied from the DC output line 4, which will be described later, and have a dimming level corresponding to the detected value of the DC voltage. It has a dimming function for dimming and lighting each of the discharge lamps 8a, 8b, 8c, ....

Therefore, when the collective DC power supply 3 outputs a DC voltage according to the dimming level on the DC output line 4,
The discharge lamp lighting device 7a connected to the DC output line 4,
7b, 7c, ... Detects the value of the DC voltage = dimming level by the voltage detection circuit and controls the operation of the inverter circuits 6a, 6b, 6c ,. Discharge lamp 8 connected to the collective DC power supply 3
The dimming lighting at the same level of a, 8b, 8c, ... Is executed.

Next, a configuration example of the collective DC power supply 3 will be described with reference to FIG. This collective DC power supply 3 is of a step-up chopper type, for example, and has a full-wave rectifier circuit 11 for full-wave rectifying the AC voltage from the commercial AC power supply 2 to DC and an output stage of the full-wave rectifier circuit 11. Connected boost chopper circuit 12
It is composed of This boost chopper circuit 12
Is composed of a step-up transformer 13, a switching transistor 14, a rectifying diode 15, and a smoothing element 16 for smoothing the output. As the smoothing element 16, for example, an electrolytic capacitor is used. For such a boost chopper circuit 12, a transistor 1 is provided.
4 for controlling the switching operation of No. 4 to maintain the voltage generated across the smoothing element 16 at a constant voltage.
Is connected. This voltage-regulating means 17 is a smoothing element 1
6, which functions as a chopper control circuit for controlling the switching speed of the transistor 14 by receiving the feedback of the value of the DC voltage generated at the both ends of 6, and thus the output terminal side. For example, SG3561 manufactured by Silicon General Co., Ltd. IC is used. Here, a dimming signal which is set from the outside and which indicates a dimming level is given to the constant voltage converting means 17, and the voltage is boosted so as to maintain the constant voltage at a value of a DC voltage according to the dimming signal. It controls the operation of the chopper circuit 12. The output stage of the boost chopper circuit 12 is connected to the DC output line 4. As a result, the collective DC power supply 3 has a certain constant voltage response speed for performing the switching operation of the transistor 14 when converting the AC voltage into the DC voltage and outputting it on the DC output line 4. The smoothing effect is exhibited at a speed corresponding to the constant voltage response speed of the smoothing element 16.

Further, a concrete configuration example of the discharge lamp lighting device or the discharge lamp lighting device connected to the DC output line 4 will be described with reference to FIG. FIG. 3 shows the discharge lamp lighting device 7 or the discharge lamp lighting device 5 extracted and shown, and the discharge lamp lighting devices 7a, 7b, 7 described above are shown.
.. or the discharge lamp lighting devices 5a, 5b, 5c ,.

First, it has an input terminal 21 connected to the DC output line 4. A discharge lamp 8 is connected between the DC voltage lines of the input terminal 21 via an inverter circuit 6. As the inverter circuit 6, for example, a half-bridge type high frequency inverter circuit is used. As a pair of switching elements forming the main part of the inverter circuit 6, for example, FETs Q ₁ and Q ₂ are provided. An inductive ballast L ₁ and a DC cut capacitor C ₁ are connected to the output line at the midpoint of connection between these FETs Q ₁ and Q _2.
One end of the discharge lamp 8 is connected via the LC resonance circuit according to. A capacitor C ₂ for preheating is provided between both ends of the discharge lamp 8.
Is connected. A resistor R ₁ for controlling the drain current is connected to the drain side of the FET Q ₂ . Further, a driving IC 22 for controlling on / off operation is connected to the gate side of these FETs Q ₁ and Q ₂ . The output of the inverter circuit 6 is variable by variably controlling the oscillation frequency, and a control IC 23 that controls the operation of the drive IC 22 is provided.

On the other hand, a voltage detection circuit 24 for detecting the value of the DC voltage input via the input terminal 21 is connected to the DC voltage line from the input terminal 21. The voltage detection circuit 24 includes a voltage dividing circuit formed by resistors R _{2 to} R ₅ connected between DC voltage lines and resistors R ₄ and R 5.
A capacitor C ₃ and a resistor R connected in parallel to ₅
A transistor Q ₃ whose base is connected between ₃ and R ₄ ,
It is composed of resistors R ₆ and R ₇ connected to the emitter and collector of the transistor Q ₃ , respectively. Here, the transistor Q is connected by the resistors R ₂ and R ₃ and the capacitor C _3.
A time constant circuit 25 for controlling the operation of ₃ is formed.
The time constant of the time constant circuit 25 is set to be slower than the constant voltage response speed on the side of the collective DC power supply 3. For example, it is set as a slow time constant of 100 Hz or less, and this time constant regulates the response speed regarding the voltage-frequency conversion as the inverter circuit 6. In such a voltage detection circuit 24, the collector current corresponding to the value of the DC voltage applied between the DC voltage lines flows through the transistor Q ₃ , so that the value of this DC voltage is determined by the control IC 23 and the DC voltage Driving IC2 so that the dimming level is equivalent to the value
The oscillation frequency of the inverter circuit 6 is variably controlled via 2. As a result, if the value of the DC voltage supplied from the collective DC power supply 3 changes, the oscillation frequency of the inverter circuit 6 is also variably controlled according to the value, and the dimming level of the discharge lamp 8 is changed. Become. The dimming control in this case is performed, for example, in the range of DC voltage 165V = 50% dimming to DC voltage 220V = 100% dimming (all lights).

In such operation control of the inverter circuit 6 side, in the voltage detection circuit 24 for detecting the value of the DC voltage supplied from the collective DC power supply 3, the time constant of the time constant circuit 25 is set to be late. Since the smoothing element 16 does not follow the ripple component cycle even if a DC voltage including a ripple component with a cycle corresponding to the constant voltage response speed is supplied by the smoothing action of the smoothing element 16, dimming control (voltage-frequency conversion) is performed. It does not occur in the cycle of the ripple component. Therefore,
There is no flicker of the period corresponding to the ripple component in the discharge lamp 8 that is dimmed and turned on according to the value of the DC voltage.

[0030]

According to the invention of claim 1, the voltage detecting circuit in the inverter circuit detects the value of the DC voltage at a response speed slower than the constant voltage response speed in the collective DC power supply. Even if the DC voltage from the collective DC power supply contains a ripple component, it is possible to control the dimming of the inverter circuit that does not follow the ripple component. Flicker corresponding to the ripple component can be prevented.

According to the second aspect of the invention, since the inverter circuit is a frequency variable control type high frequency inverter circuit, it is possible to prevent the influence of ripple components in the DC voltage used for frequency conversion.

According to the third aspect of the invention, such a slow response speed is the conversion response speed of the voltage-frequency conversion, and even if the DC voltage from the collective DC power supply includes the ripple component, the ripple component is included. Since the dimming control is performed by performing the conversion process that does not follow the above, it is possible to prevent the discharge lamp to be dimmed from flicker with simple control.

According to the invention as set forth in claim 4, since the slow response speed is set by the time constant of the time constant circuit in the voltage detection circuit, it is included in the DC voltage by the collective DC power supply with a simple structure. Flickering due to ripple components can be prevented.

According to the fifth aspect of the invention, since the discharge lamp lighting device according to any one of the first to fourth aspects is used, the dimming lighting is performed by the DC voltage supplied from the collective DC power source. A discharge lamp lighting device capable of preventing flickering of an electric lamp can be provided.

According to the sixth aspect of the invention, since the discharge lamp lighting device according to the fifth aspect is used, even if the DC voltage supplied by the collective DC power source includes a ripple component, the value of the DC voltage varies. Accordingly, it is possible to provide a lighting system capable of performing flicker-free lighting for discharge lamps that are commonly dimmed.

According to the invention described in claim 7, since the system is configured with a plurality of collective DC power sources using the plurality of discharge lamp lighting devices according to the fifth aspect, a flicker-free adjustment is provided throughout the facility. An illumination system capable of performing light illumination can be provided.

[Brief description of drawings]

FIG. 1 is a schematic wiring diagram showing a lighting system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a collective DC power supply.

FIG. 3 is a circuit diagram showing a discharge lamp lighting device and a discharge lamp lighting device.

[Explanation of symbols]

3 Collective DC power supply 4 DC output line 5 Discharge lamp lighting device 6 Inverter circuit 7 Discharge lamp lighting device 8 Discharge lamp 16 Smoothing element 17 Constant voltage conversion means 24 Voltage detection circuit 25 Time constant circuit R ₂ , R ₃ resistance C ₃ capacitor

Claims (7)

[Claims] 1. A voltage detection circuit for detecting a value of a DC voltage indicating a dimming level supplied from a DC output line of a collective DC power supply at a response speed slower than a constant voltage response speed of the collective DC power supply. A lighting device for a discharge lamp, comprising: an inverter circuit for dimming the discharge lamp. 2. The inverter circuit is a high frequency inverter circuit which variably controls the oscillation frequency according to the value of the DC voltage indicating the dimming level to dimming the discharge lamp. Lighting device for electric discharge lamp. 3. The discharge lamp according to claim 2, wherein the slow response speed of the inverter circuit is a conversion response speed for converting the value of the DC voltage supplied from the collective DC power supply into the oscillation frequency. Lighting device. 4. The slow response speed of the inverter circuit is included in the voltage detection circuit and is set by the time constant of the time constant circuit formed by the resistor and the capacitor connected between the DC output lines. The discharge lamp lighting device according to any one of claims 1 to 3. 5. A discharge lamp lighting device, comprising: the discharge lamp lighting device according to claim 1; and a discharge lamp that is energized by the discharge lamp lighting device. 6. A constant voltage converting means including a smoothing element,
6. A lighting device comprising: a collective DC power source for outputting a DC voltage indicating a dimming level to a DC output line; and a discharge lamp lighting device according to claim 5, which is connected to the DC output line of the collective DC power source. system. 7. A constant voltage converting means including a smoothing element is provided,
A plurality of collective DC power supplies that output a DC voltage indicating a dimming level to a DC output line; and a discharge lamp lighting device according to claim 5, which is connected to each of the DC output lines of each collective DC power supply. A lighting system characterized by the above.