JPH0799090A - Discharge lamp lighting device and lighting device - Google Patents

Abstract

(57) [Summary] [Purpose] Even if a plurality of discharge lamps are provided and half-wave discharge is performed in opposite directions, the end of life of the discharge lamp can be reliably detected even if the temperature of the discharge lamp rises. A discharge lamp lighting device is provided. [Configuration] Due to the high frequency generated by the inverter circuit 21,
The fluorescent lamps FL1 and FL2 are lit at high frequency. Fluorescent lamp
When one of FL1 and FL2 reaches the end of its life and half-wave discharges, current flows through the resistor R11 to charge the capacitor C15 and the voltage of the capacitor C15 rises, turning on the Zener diode ZD11 and outputting the inverter circuit 21. To stop. When the fluorescent lamps FL1 and FL2 are half-wave discharged in the opposite directions, the lamp current due to the half-wave discharge flows through the circulation path 22 and the current flows through the resistor R11. Therefore, the capacitor C15 is charged and the voltage of the capacitor C15 rises. By doing so, the Zener diode ZD11 is turned on, and the output of the inverter circuit 21 is stopped.

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 and a lighting device for lighting a plurality of discharge lamps connected in parallel.

[0002]

2. Description of the Related Art Conventionally, there is an inverter circuit as a discharge lamp lighting means for connecting a plurality of fluorescent lamps for lighting.

When the fluorescent lamp reaches the end of its life,
There is known a configuration in which the end of the life of the fluorescent lamp is detected and the output of the inverter circuit is reduced or stopped when the end of the life of the fluorescent lamp is detected in order to cause a large stress in the switching element of the inverter circuit.

As a structure for detecting the end of life, for example, a discharge lamp lighting device shown in FIG. 6 is known.

In the discharge lamp lighting device shown in FIG. 6, an inverter circuit 1 for high frequency conversion is connected to a DC power source E, and a DC cut capacitor C1 is connected to the inverter circuit 1. A choke coil L1, a series circuit of filaments FL1a and FL1b of the fluorescent lamp FL1, and a choke coil L2 and a filament of the fluorescent lamp FL2 are connected to both ends of the inverter circuit 1 via a capacitor C1.
A series circuit of FL2a and FL2b is connected in parallel. Also,
A starting capacitor C2 is connected between the filaments FL1a and FL1b of the fluorescent lamp FL1, and a starting capacitor C3 is connected between the filaments FL2a and FL2b of the fluorescent lamp FL2.

Further, the filament of each fluorescent lamp FL1
Filament FL between FL1a and FL1b and fluorescent lamp FL2
The lamp voltage detection circuit 2 is connected between 2a and FL2b,
The lamp voltage detection circuit 2 is connected to the inverter circuit 1 via the control circuit 3.

Then, the voltage of the DC power source E is converted into high frequency alternating current by the inverter circuit 1, and the fluorescent lamps FL1 and FL2 are lit at high frequency. Further, when the lamp voltage detected by the lamp voltage detection circuit 2 exceeds a predetermined value, it is judged that one of the fluorescent lamps FL1, FL2 is at the end of its life, the control circuit 3 is operated, and the output of the inverter circuit 1 is stopped. Let

However, when the temperature of the fluorescent lamps FL1 and FL2 becomes high, the lamp voltage of the fluorescent lamps FL1 and FL2 becomes low, so that even if the lamp voltage rises at the end of life,
As the lamp voltage decreases with increasing temperature, fluorescent lamps
The end of life of FL1 and FL2 cannot be detected.

As another conventional example, for example, a discharge lamp lighting device shown in FIG. 7 is known.

In the conventional example shown in FIG. 7, two fluorescent lamps FL1 and FL2 are connected in parallel as in the configuration shown in FIG. 6, and instead of the lamp voltage detecting circuit 2, a capacitor C1 is used. In parallel, the resistor R1 and the input terminal of the full-wave rectifier 4 are connected, and between the output terminals of this full-wave rectifier 4,
The capacitor C4 and the control circuit 5 including a series circuit of the Zener diode ZD1 and the light emitting diode LED1 are connected.

Any one of the fluorescent lamps FL1, FL2
At the end of its life, half-wave discharge occurs and a direct current flows, so this direct current component is detected by resistor R1, and full-wave rectifier 4 charges capacitor C4 regardless of the polarity of the direct current component, and capacitor C4 When the voltage rises, the Zener diode ZD1 turns on, the light emitting diode LED1 lights up, and the output of the inverter circuit 1 is stopped.

However, for example, when the fluorescent lamp FL1 is half-wave discharged from the filament FL1a side to the filament FL1b side and the fluorescent lamp FL2 is half-wave discharged from the filament FL2b side to the filament FL2a side, the respective half-wave discharges cancel each other out. The end of life of the fluorescent lamps FL1 and FL2 may not be detected.

[0013]

As described above, in the discharge lamp lighting device shown in FIG. 6, when the temperature of the fluorescent lamps FL1 and FL2 rises, the lamp voltage of the fluorescent lamps FL1 and FL2 lowers. There is a problem that the end of life of FL1 and FL2 may not be detected.

In the discharge lamp lighting device shown in FIG. 7, when the half-wave discharge directions of the fluorescent lamps FL1 and FL2 are opposite to each other, the lamp currents cancel each other and the half-wave discharge cannot be detected. I have a problem.

The present invention has been made in view of the above problems, and reliably discharges even if a plurality of discharge lamps are provided and half-wave discharge is performed in opposite directions, or if the temperature of the discharge lamp changes. An object of the present invention is to provide a discharge lamp lighting device and a lighting device capable of detecting the end of life of a lamp.

[0016]

A discharge lamp lighting device according to claim 1, wherein discharge lamp lighting means for lighting a plurality of discharge lamps connected in parallel, and a circulation path circulating between the plurality of discharge lamps. Current detecting means provided in the circulation path for detecting the lamp current of the discharge lamp, and at least one of decreasing and stopping the output of the discharge lamp lighting means when the current detected by the current detecting means is equal to or more than a predetermined value. And a control means for controlling one of the states.

A discharge lamp lighting device according to a second aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein the current detecting means is formed of an impedance element, and detects based on the voltage across the impedance element. is there.

A discharge lamp lighting device according to a third aspect of the present invention is the discharge lamp lighting device according to the first or second aspect, wherein the plurality of discharge lamps are three, and the impedance element is Δ-connected and Y.
It is one of the connections.

According to a fourth aspect of the present invention, there is provided an illuminating device in a fixture body,
The discharge lamp lighting device according to any one of claims 1 to 3 is provided.

[0020]

In the discharge lamp lighting device according to the first aspect, the current detecting means in the circulation path circulating between the plurality of discharge lamps connected in parallel detects the lamp current of the discharge lamp, and the current is equal to or more than the predetermined value. When the control means controls the output of the discharge lamp lighting means to at least one of the states of lowering and stopping, even if the half-wave discharge directions of the respective discharge lamps are reversed, the half-wave discharge can be detected, The end of life of the discharge lamp can be detected with a simple configuration.

A discharge lamp lighting device according to a second aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein the current detecting means detects the voltage based on the voltage across the impedance element.
The lamp current of the discharge lamp can be detected with a simple configuration.

A discharge lamp lighting device according to a third aspect of the present invention is the discharge lamp lighting device according to the second aspect, wherein the plurality of discharge lamps are three and the impedance elements are Δ-connected or Y-connected, so that the structure is simple. Lamp current can be detected.

The illuminating device according to claim 4 is a fixture main body,
Since the discharge lamp lighting device according to any one of claims 1 to 3 is provided, the end of life of the discharge lamp can be detected with a simple configuration.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the illumination device of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, the luminaire main body 11 is provided with lamp sockets 12, 12 at both ends of the lower surface, and a fluorescent lamp FL as a discharge lamp is provided between the lamp sockets 12, 12.
1 and FL2 are sandwiched and connected. A reflecting surface 13 is formed optically corresponding to the fluorescent lamps FL1 and FL2, and a discharge lamp lighting device 14 is provided on the inner surface side of the reflecting surface 13.

In this discharge lamp lighting device 14, as shown in FIG. 1, for example, an inverter circuit 21 as a discharge lamp lighting means is connected to a DC power source E constituted by a rectifying and smoothing commercial AC power source or a battery. There is.

Between the output terminals of the inverter circuit 21, there are a DC cut capacitor C11, a choke coil L11, a series circuit of filaments FL1a and FL1b of the fluorescent lamp FL1, and a DC cut capacitor C12 and a choke coil. L12, filament FL2a of fluorescent lamp FL2,
The FL2b series circuit is connected in parallel. A starting capacitor C13 is connected between the filaments FL1a and FL1b of the fluorescent lamp FL1, and a starting capacitor C14 is connected between the filaments FL2a and FL2b of the fluorescent lamp FL2.

Further, between the connection point of the DC cut capacitor C11 and the choke coil L11 and the connection point of the DC cut capacitor C12 and the choke coil L12, a resistor R11 which is an impedance element as current detection means is provided. Connected with choke coil L11, fluorescent lamp
FL1, fluorescent lamp FL2, choke coil L12, resistor R11
A circulation path 22 is formed by the choke coil L11.

An input terminal of the full-wave rectifier 23 is connected between both terminals of the resistor R11, and a smoothing capacitor C15 is connected to an output terminal of the full-wave rectifier 23. Both ends of the capacitor C15 are connected to each other. Between the terminals is a control means 24 consisting of a series circuit of a Zener diode ZD11 and a light emitting diode LED11.
Are connected.

Next, the operation of the above embodiment will be described.

First, the voltage of the DC power source E is converted into an inverter circuit.
The high-frequency alternating current is converted at 21 and the fluorescent lamps FL1, FL2 are lit at high frequency by the high-frequency generated by the inverter circuit 21.

When neither of the fluorescent lamps FL1 and FL2 is at the end of life, the fluorescent lamps FL1 and FL2 are also discharged bidirectionally, so that the capacitor C11 for cutting the direct current is used.
Since there is almost no potential difference between the connection point of the choke coil L11 and the connection point of the DC cut capacitor C12 and the choke coil L12, no current flows through the resistor R11 and the capacitor C15 is not charged. Therefore, the Zener diode ZD11 remains off, and the inverter circuit 21 oscillates normally to turn on the fluorescent lamps FL1 and FL2 normally.

On the other hand, the fluorescent lamp FL1 or the fluorescent lamp FL
If either one of 2 is at the end of its life and half-wave discharges, there is a potential difference between the connection point of DC cut capacitor C11 and choke coil L11 and the connection point of DC cut capacitor C12 and choke coil L12. Occurs, a current flows through the resistor R11 and charges the capacitor C15. When the voltage of the capacitor C15 rises, the Zener diode ZD11 is turned on, and the output of the inverter circuit 21 is reduced or stopped to reduce or stop the lighting state of the fluorescent lamps FL1 and FL2, causing stress in the inverter circuit 21. Prevent that.

Further, for example, the fluorescent lamp FL1 is half-wave discharged from the filament FL1a side to the filament FL1b side, and the fluorescent lamp FL2 is discharged from the filament FL2b side to the filament FL2a side.
In the case of half-wave discharge to the side, the lamp current due to the half-wave discharge flows in the circulation path 22 of the fluorescent lamp FL1, the fluorescent lamp FL2, the choke coil L12, the resistor R11, the choke coil L11, and the fluorescent lamp FL1, and the resistor R11 current Will flow, so charge the capacitor C15. And capacitor C1
When the voltage of 5 rises, the Zener diode ZD11 is turned on, and the output of the inverter circuit 21 is reduced or stopped to reduce or stop the lighting state of the fluorescent lamps FL1, FL2 and prevent the inverter circuit 21 from being stressed. To do.

Furthermore, the fluorescent lamp FL1 is a filament FL.
Half-wave discharge from 1a side to filament FL1b side, fluorescent lamp
When FL2 is half-wave discharged from filament FL2b side to filament FL2a side, fluorescent lamp FL2, fluorescent lamp FL1
, Choke coil L11, resistor R11, choke coil L12
Since the lamp current due to the half-wave discharge flows through the circulation path 22 of the fluorescent lamp FL2 and the current flows through the resistor R11, the capacitor C15 is charged and the same operation is performed.

Next, another embodiment will be described with reference to FIG.

In the embodiment shown in FIG. 3, the resistor R11 is divided into two resistors R11a and R11b in the embodiment shown in FIG. 1, and the connection point of the resistors R11a and R11b is connected to the capacitor C15.
Connected to one end of the resistor R11a and the other end of the resistor R11b instead of the full-wave rectifier 23 diode D11 or diode D1
It is connected to the other end of capacitor C15 via 2.

Even with such a connection, the operation is similar to that shown in FIG.

Further, another embodiment will be described with reference to FIG.

The embodiment shown in FIG. 4 is different from the embodiment shown in FIG. 4 in that the positive electrode of the inverter circuit 21 and the resistors R11a and R11b are connected.
A resistor R12 is connected between the diode D13 and the positive electrode of the inverter circuit 21, and a diode D13 is connected between the connection point of the diode D11 and the diode D12.

Besides the operation shown in FIG. 3, for example, the fluorescent lamp FL1 is half-wave discharged from the filament FL1a side to the filament FL1b side, and the fluorescent lamp FL1 is also similarly discharged.
When 2 is half-wave discharged from the filament FL2a side to the filament FL2b side, the direct current contained in the output from the inverter circuit 21 flows through the resistor R12 and charges the capacitor C15. Then, the Zener diode ZD11 is turned on when the voltage of the capacitor C15 rises, and the output of the inverter circuit 21 is lowered or stopped, and the fluorescent lamp FL1,
The lighting state of FL2 is lowered or stopped to prevent the inverter circuit 21 from being stressed.

Further, the fluorescent lamp FL1 is a filament FL1b.
Side from the side to the filament FL1a side, and similarly, when the fluorescent lamp FL2 also performs a half-wave discharge from the filament FL2b side to the filament FL2a side, the same operation is performed.

Still another embodiment will be described with reference to FIG.

The embodiment shown in FIG. 5 is different from the embodiment shown in FIG. 3 in that the DC cut capacitor C11, the choke coil L11, and the filaments FL1a and FL1b of the fluorescent lamp FL1.
Series circuit and capacitor C12 for DC cut,
Choke coil L12, filament FL of fluorescent lamp FL2
The series circuit of 2a and FL2b is further connected with a series circuit of a capacitor C16 for cutting direct current, a choke coil L13, and filaments FL3a and FL3b of a fluorescent lamp FL3 as a discharge lamp. Also, a DC cut capacitor
Resistor R11c is connected to the connection point of C16 and choke coil L13.
This resistor R11c is connected to the resistor R11a and the resistor R11b.
At the same time, Δ is connected. These resistors R11a,
You may make Y connection by resistance R11b and resistance R11c.

By connecting in this manner, three fluorescent lamps FL1, FL2, FL3 can be used.

[0046]

According to the discharge lamp lighting device of the first aspect of the invention, the lamp current of the discharge lamp is detected by the current detecting means in the circulation path circulating between the plurality of discharge lamps connected in parallel. Since the control means controls the output of the discharge lamp lighting means to at least one of the state of lowering and stopping when the value is equal to or more than the predetermined value, even if the half-wave discharge direction of each discharge lamp is reversed, the half-wave discharge Can be detected, and the end of life of the discharge lamp can be detected with a simple configuration.

According to the discharge lamp lighting device of the second aspect,
In addition to the discharge lamp lighting device according to the first aspect, since the current detection means detects based on the voltage across the impedance element, the lamp current of the discharge lamp can be detected with a simple configuration.

According to the discharge lamp lighting device of the third aspect,
In addition to the discharge lamp lighting device according to the second aspect, the plurality of discharge lamps are three lamps, and the impedance elements are Δ-connected or Y-connected, so that the lamp current can be detected with a simple configuration.

According to the lighting device of the fourth aspect, since the discharge lamp lighting device according to any one of the first to third aspects is provided in the fixture body, the end of life of the discharge lamp can be detected with a simple structure.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a discharge lamp lighting device of the present invention.

FIG. 2 is a perspective view showing the outer appearance of the above lighting device.

FIG. 3 is a circuit diagram showing another embodiment of the same as above.

FIG. 4 is a circuit diagram showing another embodiment of the above.

FIG. 5 is a circuit diagram showing still another embodiment of the same.

FIG. 6 is a circuit diagram showing a conventional discharge lamp lighting device.

FIG. 7 is a circuit diagram showing another conventional discharge lamp lighting device.

[Explanation of symbols]

11 Lighting fixture body 14 Discharge lamp lighting device 21 Inverter circuit as discharge lamp lighting means 22 Circulation path 24 Control means FL1, FL2, FL3 Fluorescent lamp as discharge lamp R11, R11a, R11b, R11c Impedance element as current detection means Some resistance

Claims (4)

[Claims] 1. A discharge lamp lighting means for lighting a plurality of discharge lamps connected in parallel, a circulation path circulating between the plurality of discharge lamps, and a lamp current of the discharge lamp provided in the circulation path. And a control means for controlling the output of the discharge lamp lighting means to at least one of a reduced state and a stopped state when the current detected by the current detection means is a predetermined value or more. Characteristic discharge lamp lighting device. 2. The discharge lamp lighting device according to claim 1, wherein the current detecting means is formed of an impedance element and detects the voltage based on the voltage across the impedance element. 3. The discharge lamp lighting device according to claim 2, wherein the plurality of discharge lamps are three lamps, and the impedance element is one of Δ connection and Y connection. 4. An illuminating device comprising a fixture main body provided with the discharge lamp lighting device according to claim 1.