JPH0997690A - Discharge lamp lighting device and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent danger leading to brakage of lamp before hand by detecting abnormal discharge caused by deformation of electrode or the like. SOLUTION: By detecting abnormal rise of lamp voltage through safe circuit means 600, power of AC power supply 1 to be supplied to an electric discharge lamp 4 can be shut out and abnormal heating in the lamp 4 caused by deformation in an electrode can be prevented before hand. This device is especially effective when it is applied to a high pressure electric discharge lamp such as a metal halide lamp used as the discharge lamp 4.

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 for detecting an abnormality in a lamp voltage waveform occurring at the end of a lamp life or the like to prevent a lamp from being damaged and a lighting device using the same.

[0002]

2. Description of the Related Art Generally, a high pressure discharge lamp (also referred to as HID lamp; HID = High Intensity Discharge) includes a high pressure sodium lamp, a metal halide lamp, a high pressure mercury lamp and the like.

A high-pressure discharge lamp is a light source utilizing arc discharge under high pressure, and is generally known to have high brightness.

Since such a high pressure discharge lamp lighting device requires a high voltage pulse for starting at the time of starting, it is provided with a pulse generating circuit.

Regarding this pulse generation circuit, as the prior art, (1) a type in which a pulse is generated from the pulse generation circuit for a certain period of time when the high pressure discharge lamp is started, and then the pulse is stopped, (2) when the high pressure discharge lamp is started There is a type in which a pulse is generated and the discharge lamp lighting is detected to automatically stop the pulse generation, or the pulse generation is automatically stopped when the discharge lamp is not lighted for a certain period of time.

Among high pressure discharge lamps, metal halide lamps are known as light sources capable of emitting light with a continuous spectrum that is closest to natural daylight. There are two types of metal halide lamps, short arc type and long arc type, depending on the shape of the arc tube. The short arc type is a round discharge tube with opposite electrodes sealed at intervals of several millimeters, and the long arc type is a long discharge tube with opposite electrodes sealed at both ends. In general, the short arc type is
The enclosed gas pressure is higher than that of the long arc type.

FIG. 3 is a block diagram showing a conventional discharge lamp lighting device. In FIG. 3, a commercial AC power source (for example, 10
One end of (0 V power supply) 1 is connected to one input end a of the ballast 2 through the power switch SW, and the other end of the AC power supply 1 is connected to the other input end b of the ballast 2. One output end c is connected to one end t1 of the pulse transformer 3, and the other end t3 of the pulse transformer 3 is connected to one end of the discharge lamp 4. The other end of the discharge lamp 4 is connected to the ballast 2 via the current detecting means 5.
Is connected to the other output end d.

The ballast 2 is, for example, a choke coil C connected in series to one terminal of the AC power source 1 as shown in FIG.
H1 and a power factor improving capacitor C1 connected in parallel to both ends of the AC power supply 1 on the input side and a discharging resistor R1 connected in parallel to the capacitor C1.

As the discharge lamp 4, for example, a short arc type metal halide lamp is used. The current detecting means 5 is composed of, for example, a current transformer.

The intermediate terminal t2 of the pulse transformer 3 and the terminal t3 are connected to the pulse circuit 6. The pulse transformer 3 and the pulse circuit 6 constitute a pulse generating means 30 for generating a high voltage pulse at the time of starting.

The pulse circuit 6 is constructed, for example, as shown in FIG. In FIG. 5, the terminal t2 of the pulse transformer 3
A pulse capacitor C2 is connected to the pulse transformer 3
The trigger element S2 is connected to the terminal t3 of the pulse capacitor C2, and the terminals of the pulse capacitor C2 and the side opposite to the pulse transformer 3 of the trigger element S2 are both connected to one end of the resistor R2, and the other end of the resistor R2 is connected via the switch 7. It is connected to the other output end d of the ballast 2.

Returning to FIG. 3, the output terminal c of the ballast 2 is
A control means 80 is connected to d in parallel therewith.
The control means 80 is composed of the control power supply 8 and the pulse stop circuit 9. The control power source 8 is a DC voltage generating means (not shown) for converting the AC voltage from the ballast 2 into a DC voltage, and a timer circuit (not shown) that operates using this DC voltage as a power source.
Is provided. The DC voltage generated by the DC voltage generating means of the control power supply 8 is also supplied to the pulse stop circuit 9 as a power supply. The pulse stop circuit 9 turns on / off the switch 7 by using the voltage input from the current detection means 5 as a trigger.
Off is controlled.

In the above structure, when the power switch SW is turned on at the time of starting, the power voltage is supplied to the control means 80 through the ballast 2, and the control means 80 turns on the switch 7. At this time, the timer circuit in the control power supply 8 also starts operating. When the switch 7 is turned on, the output terminal c of the ballast 2, the terminal t2 of the pulse transformer 3, the pulse circuit 6
Current flows through the series circuit of the pulse capacitor C2, the resistor R2, the switch 7, and the output terminal d of the ballast 2, and the pulse capacitor C2 (see FIG. 5) is charged. When the voltage between the terminals (between the electrodes) of the pulse capacitor C2 reaches a predetermined value, the trigger element S2 is turned on and the pulse capacitor C2 is instantaneously discharged, and between the terminals t2 and t3 of the pulse transformer 3. A high voltage is induced, a start pulse voltage is applied to both ends of the discharge lamp 4, and the discharge lamp 4 lights up.

Then, the pulse stop circuit 9 of the control means 80
When the discharge lamp 4 is turned on, this is detected by the current detection means 5 and is controlled so as to turn off the switch 7, thereby stopping the high-voltage pulse generation in the pulse generation means 30. Alternatively, the control means 80, if the lighting of the discharge lamp 4 by the current detection means 5 is not detected even after a lapse of a certain time after the AC power switch SW is turned on, the timer circuit in the control power supply 8 times up. Thus, the pulse stop circuit 9 controls the switch 7 to be turned off, thereby stopping the high-voltage pulse generation in the pulse generation means 30.

[0015]

By the way, when a short arc type metal halide lamp as shown in FIGS. 6 (a) and 6 (b) is used as the discharge lamp 4, when the discharge lamp 4 is used as shown in FIG. At the end of the lamp life, the electrodes 41 and 42 as shown in a) are consumed and the electrodes are deformed as shown in FIG. 6B, and the arc length becomes long. That is, the electrodes 41, 42 in the initial stage of use
For the arc length LA between them, the arc length becomes LA '(LA'> LA) due to electrode deformation at the end of life.

The waveforms of the lamp voltage VL at the beginning of use and at the end of life of the lamp are generally as shown in FIGS. 7 (a) and 7 (b). That is, the initial voltage waveform of the lamp voltage VL is as shown in FIG. 7 (a), but when the electrode is deformed as shown in FIG. 6 (b) at the end of life,
The ramp voltage waveform is a waveform in which a shaded portion is added to the waveform of FIG. 7 (a) as shown in FIG. 7 (b) (that is, o-a-e).
-D-b-c waveform), and the lamp voltage rises.
Note that the voltage waveform in FIG. 7 shows only a half-cycle waveform on the positive electrode side of the commercial power supply frequency. The half-cycle waveform on the negative electrode side has the same waveform except that the polarities are different.

By the way, in the prior art, it is not possible to detect a lamp voltage abnormality due to electrode deformation of a high pressure discharge lamp such as a short arc type metal halide lamp,
For this reason, when the lamp voltage rises, there is a problem that lighting is maintained even though the sealing portion of the lamp electrode portion has reached an abnormal temperature, causing a risk of lamp damage or the like.

Therefore, an object of the present invention is to provide a discharge lamp lighting device and a lighting device capable of detecting abnormal discharge such as electrode deformation and preventing the risk of damage to the lamp. Is.

[0019]

According to another aspect of the present invention, there is provided a discharge lamp lighting device including an AC power supply; a discharge lamp to which the AC power is supplied; and an interposing between the AC power supply and the discharge lamp. A ballast having an inductance that limits the current at the time of starting and lighting the discharge lamp; and a discharge lamp that is provided between the discharge lamp and the ballast and generates a high-voltage pulse by a pulse transformer at the start of the discharge lamp. Lighting circuit means for detecting this when the lamp is lit and stopping the generation of the high voltage pulse, or detecting it when the discharge lamp has not been lit for a certain time and stopping the generation of the high voltage pulse; A safety circuit means for detecting the lamp voltage waveform of the discharge lamp at the time, determining whether the voltage waveform is abnormal, and cutting off the power supply from the AC power source when it is determined to be abnormal;
It is provided with. As the discharge lamp, a high pressure discharge lamp,
For example, high pressure sodium lamps, metal halide lamps and high pressure mercury lamps are allowed.

According to a second aspect of the present invention, in the discharge lamp lighting device according to the first aspect, the lighting circuit means is provided between the ballast and the discharge lamp, and when the discharge lamp is started, a high voltage pulse is generated by a pulse transformer. Generating means for generating and supplying the discharge lamp to the discharge lamp; first detecting means for detecting a lighting state of the discharge lamp; operating based on a power supply voltage between the ballast and the pulse generating means And a control means for controlling ON / OFF of the high-voltage pulse generation of the pulse generation means by using the detection signal from the first detection means. The first detecting means may be any means that detects the lighting by detecting the lamp current of the discharge lamp, and for example, a current transformer is used. As the control means, when the first detection means detects the lighting of the discharge lamp, the high voltage pulse generation is stopped (turned off), and when it is not lit for a certain period of time, this is detected by a timer to stop the high voltage pulse generation ( Off).

According to a third aspect of the present invention, in the discharge lamp lighting device according to the first aspect, the safety circuit means detects a voltage obtained by rectifying and smoothing the voltage waveform of the AC power source when the discharge lamp is lit, and detects the lamp voltage waveform. Second detecting means for detecting a voltage corresponding to an invariant portion; third detecting means provided between the ballast and the pulse generating means for detecting a voltage obtained by rectifying and smoothing the lamp voltage waveform of the discharge lamp. Comparing means for obtaining the changed portion of the ramp voltage waveform by taking the difference between the output voltage of the third detecting means and the output voltage of the second detecting means; and the difference amount obtained from the comparing means has a predetermined value. And a switch means that operates when the voltage exceeds the limit and cuts off the power supply from the AC power supply.

According to a fourth aspect of the present invention, the safety circuit means in the discharge lamp lighting device according to the third aspect is characterized in that after the discharge lamp is started,
It is further characterized by further comprising timer means for causing the second detecting means to start the operation of detecting the voltage waveform of the AC power supply when it is detected that a predetermined time has elapsed. The timer means is composed of a timer as a time limiter and a switch for turning on the power supply to the second detecting means when the timer has passed a certain time.

According to a fifth aspect of the present invention, there is provided a detecting means for detecting whether or not the switch means in the discharge lamp lighting device according to the third aspect has exceeded a predetermined value from the comparing means; and this detecting means. Means for generating a drive signal when it is detected that the predetermined value is exceeded, and a relay for disconnecting the power supply from the AC power source based on the drive signal.
Is provided.

According to a sixth aspect of the present invention, the safety circuit means in the discharge lamp lighting device according to the first aspect detects an increase in the lamp voltage due to electrode deformation at the end of life with respect to the initial lamp voltage waveform of the discharge lamp, When the amount of increase exceeds a predetermined range, power supply from the AC power supply is cut off.

According to a seventh aspect of the present invention, in the discharge lamp lighting device according to any one of the first to sixth aspects,
It is a short arc type metal halide lamp.

An illuminating device according to the invention of claim 8 is a luminaire main body; and the luminaire main body is housed in the luminaire main body.
And a discharge lamp lighting device according to any one of the above. The lighting device may be an indoor lighting device or an outdoor lighting device such as a street light.

According to the present invention, the abnormality of the lamp voltage waveform can be detected and the AC power supply to the discharge lamp can be cut off, and the abnormality of the discharge lamp due to the abnormality of the lamp voltage can be detected. Can be prevented.

According to the second aspect of the present invention, if a high-voltage pulse necessary for starting the discharge lamp is generated and lit, the high-voltage pulse is detected and the high-voltage pulse is stopped, or after the high-voltage pulse is generated, no lighting is performed for a certain period of time. Then, this is detected and the generation of the high voltage pulse is stopped, so that a safe and energy-saving lighting circuit at the time of starting can be configured.

In the invention of claim 4, at the time of starting the discharge lamp, a lamp current 1.2 to 1.7 times as high as that at the time of stable lighting flows for several minutes. During this start-up period, the power supply voltage may drop significantly, so the detection by the second detection means should not be performed for several minutes until the discharge lamp reaches stable lighting.
This prevents voltage waveform comparisons during unstable time zones.

According to the sixth aspect of the invention, the abnormality of the lamp voltage waveform due to the deformation of the electrode at the end of its life is detected and the supply of the AC power supply is cut off. Therefore, the abnormal heating of the electrode is prevented and the safety is improved. be able to.

According to the invention of claim 7, when it is used as a discharge lamp lighting device for a short arc type metal halide lamp having a narrow gap between opposed electrodes, abnormal heating due to electrode deformation can be prevented in advance, which is particularly useful.

In the invention of claim 8, claims 1 to 7 are provided.
Since the discharge lamp lighting device according to any one of the above 1 is provided in the main body of the lighting fixture, even if an abnormality occurs in the discharge lamp, the safety of the lighting device can always be ensured.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described with reference to the drawings. FIG. 1 shows a block diagram of a discharge lamp lighting device according to an embodiment of the present invention. The same parts as those in FIG. 2 will be described with the same reference numerals.

In FIG. 1, the discharge lamp lighting device 200 is
The AC power source 1, the discharge lamp 4 to which the power from the AC power source 1 is supplied, and the inductance which is interposed between the AC power source 1 and the discharge lamp 4 and which limits the current at the time of starting and lighting the discharge lamp It is composed of a ballast 2, a lighting circuit means 400, and a safety circuit means 600.

The lighting circuit means 400 is provided between the discharge lamp 4 and the ballast 2, and when the discharge lamp is started, the pulse transformer 3 is provided.
While generating the high-voltage pulse for starting at, the discharge lamp 4 is detected when it is turned on to stop the high-voltage pulse generation, or when the discharge lamp 4 is not turned on for a certain period of time, this is detected. It has a function of stopping the generation of the high-voltage pulse.

The safety circuit means 600 detects the lamp voltage waveform of the discharge lamp 4 when the discharge lamp is lit, determines whether or not the voltage waveform is abnormal, and when it is determined to be abnormal, the AC power supply 1 It has the function of shutting off the power supply.

The details of the above configuration will be described below. First, the configurations of the AC power supply 1, the discharge lamp 4, the ballast 2, and the lighting circuit means 400 will be described.

Commercial AC power supply (for example, 100V power supply) 1
Is connected to one input end a of the ballast 2 via the power switch SW, the other end of the AC power supply 1 is connected to the other input end b of the ballast 2, and one output end of the ballast 2 is connected. c is connected to one end t1 of the pulse transformer 3, and the other end t3 of the pulse transformer 3 is connected to one end of the discharge lamp 4. The other end of the discharge lamp 4 is connected to the other output end d of the ballast 2 with the current detecting means 5 interposed.

The ballast 2 is a choke coil CH connected in series to one terminal of the AC power source 1 as shown in FIG.
1 and a power factor improving capacitor C1 connected in parallel to both ends of the AC power source 1 and a discharging resistor R1 of the capacitor C1.

As the discharge lamp 4, for example, a short arc type metal halide lamp is used. The current detection means 5 is composed of, for example, a current transformer, and detects the lamp current flowing while the discharge lamp is lit to detect the discharge lamp 4
Detects whether or not is lit, and outputs a detection signal indicating the presence or absence of a lamp current.

The intermediate terminal t2 of the pulse transformer 3 and the terminal t3 are connected to the pulse circuit 6. The pulse transformer 3 and the pulse circuit 6 constitute a pulse generating means 30 for generating a high voltage pulse for starting and supplying it to the discharge lamp 4 at the time of starting the discharge lamp.

The pulse circuit 6 has the same structure as that shown in FIG. That is, the pulse capacitor C2 is connected to the terminal t2 of the pulse transformer 3, the trigger element S2 is connected to the terminal t3 of the pulse transformer 3, and the terminals of the pulse capacitor C2 and the trigger element S2 opposite to the pulse transformer 3 are Both are connected to one end of the resistor R2, and the other end of the resistor R2 is connected to the other output end d of the ballast 2 via the switch 7.

A control means 80 is connected in parallel with the output terminals c and d of the ballast 2. Control means 80
Is composed of a control power supply 8 and a pulse stop circuit 9. The control power supply 8 includes a DC voltage generating means (not shown) for converting the AC power supply voltage from the ballast 2 into a DC voltage, and a timer circuit (not shown) for operating the DC voltage as a power supply. The DC voltage generated by the DC voltage generating means of the control power supply 8 is also supplied to the pulse stop circuit 9 as a power supply.
The pulse stop circuit 9 controls the ON / OFF of the switch 7 by using the detection signal output from the current detection means 5 as a trigger input. That is, the control means 80
In the case where the switch 7 is turned off by using the detection signal indicating the presence of the lamp current from the current detection means 5, while the internal timer circuit is activated after the power is turned on and the discharge lamp 4 does not light up even after a lapse of a certain time, Based on the time-up output from the timer circuit, the pulse stop circuit 9 turns off the switch 7,
Control is performed so as to stop the high-voltage pulse generation of the pulse generation means 30.

Next, the structure of the safety circuit means 600, which is a feature of the embodiment of the present invention, will be described.

A timer 10 is connected in parallel to both ends of the AC power supply 1, and a switch 11 is connected in series with one end of the AC power supply 1. The output of the timer 10 turns on the switch 11.
It is designed to be turned off. The timer means 100 is configured by the timer 10 and the switch 11, and the timer 10 starts operating when the voltage of the AC power supply 1 is turned on by the power switch SW, and when the preset time has elapsed, the timer 10 is started. A time-up signal is output from 10, and the switch 11 is turned on by the signal. The AC power supply voltage that has passed through the timer means 100 is supplied to the voltage detection means 12 after a lapse of a certain time after the power is turned on. Voltage detection means 1
2 detects a voltage obtained by rectifying and smoothing the voltage waveform of the AC power supply 1 when the discharge lamp 4 is lit, and thereby, even if the power supply voltage of the AC power supply 1 fluctuates, a constant voltage serving as a reference is always detected. It can be output. Therefore, the voltage detecting means 12 is also called a power supply fluctuation compensating circuit. The voltage generated by the voltage detecting means 12 is a voltage corresponding to the invariant portion of the lamp voltage waveform of o-adbc, in the case of the lamp voltage waveform of FIG. 7 (b).

In the power supply line between the AC power supply 1 and the ballast 2, a switch 1 for cutting off the power supply to the discharge lamp 4 is provided.
6a is provided. The switch 16a is a switch portion of the relay 16 described later.

Voltage detecting means 13 is connected in parallel with the output terminals c and d of the ballast 2. The voltage detecting means 13 is provided between the ballast 2 and the pulse generating means 30 and detects a voltage obtained by rectifying and smoothing the lamp voltage waveform of the discharge lamp 4. The voltage generated by the voltage detecting means 13 is o-a-e-, in terms of the lamp voltage waveform of FIG. 7 (b).
It is a voltage corresponding to the lamp voltage waveform including the fluctuation part of dbc.

The output voltage of the voltage detection means 12 and the output voltage of the voltage detection means 13 are input to the comparison means 14 and the difference between them is output. That is, the output corresponding to the fluctuation of the lamp voltage waveform is obtained from the comparison means 14. As the comparison means 14, for example, a differential amplifier is used. The output of the comparison means 14 is input to the drive circuit 15. The drive circuit 15 detects a detection unit (not shown) for detecting whether the difference value from the comparison unit 14 exceeds a predetermined value and a relay drive signal when the detection unit detects that the difference value exceeds the predetermined value. And means (not shown) for generating. The relay 16 operates by the relay drive signal output from the drive circuit 15 and operates so as to turn off the switch portion 16a thereof, thereby cutting off the power supply from the AC power supply 1 to the discharge lamp 4. To do. That is, the relay 16 operates so as to cut off the AC power supply to the discharge lamp 4 when the variation of the lamp voltage waveform exceeds the threshold and becomes abnormally high.

In the above configuration, when the power switch SW is turned on at the time of starting, the power supply voltage from the AC power supply 1 is supplied to the control means 80 through the ballast 2, and the control means 80 is supplied.
Turns on the switch 7. This allows ballast 2
A current flows through a series circuit of the output terminal c of the pulse transformer 3, the terminal t2 of the pulse transformer 3, the pulse capacitor C2 of the pulse circuit 6, the resistor R2, the switch 7, and the output terminal d of the ballast 2, and the pulse capacitor C2 is charged. When the voltage between the terminals (between the electrodes) of the pulse capacitor C2 reaches a predetermined value,
The trigger element S2 is turned on, the pulse capacitor C2 is discharged instantaneously, and the terminals t2, t of the pulse transformer 3 are discharged.
A high voltage is induced during 3 and a start pulse voltage is applied to both ends of the discharge lamp 4 to light the discharge lamp 4.

When the discharge lamp 4 is turned on, the current detecting means 5 detects it and transmits it to the pulse stop circuit 9 of the control means 80. The pulse stopping circuit 9 turns off the switch 7 based on the detection signal from the current detecting means 5 to stop the high-voltage pulse generation by the pulse generating means 30. Alternatively, the control means 80 turns off the switch 7 based on the operation of the timer circuit in the control power supply 8 even when the lighting of the discharge lamp 4 is not confirmed even after a lapse of a certain time after the AC power is input. Then, the high voltage pulse generation is stopped.

When, for example, a short arc type metal halide lamp is used as the discharge lamp 4, the waveform of the lamp voltage VL when the discharge lamp 4 is lit is shown in FIG. It becomes as shown. However, when the discharge lamp 4 reaches the end of its life, the electrodes are worn out as shown in Fig. 6 (b), the electrodes are deformed, and the arc length becomes L.
It becomes long like A '. The lamp voltage waveform at the time of lighting the discharge lamp in this case is as shown in FIG. 7 (b).

When the power switch SW is turned on at the time of starting,
The lighting circuit means 400 operates as described above to light the discharge lamp 4, but at the same time, the power supply voltage from the AC power supply 1 is also supplied to the safety circuit means 600. Safety circuit means 600
Then, when the power is turned on, the timer-10 operates. The timer-10 outputs a time-up signal after a lapse of a fixed time (several minutes), and turns on the switch 11 by the signal. The set time of the timer 10 is the lighting circuit means 400.
By this, the discharge lamp 4 is started and lit, and the discharge lamp 4 is set for several minutes required to reach a stable lighting state. The input current at the time of starting the discharge lamp 4 is 1.2 to 1.7 when it is stable.
A double current flows for several minutes, and the power supply voltage may drop significantly during this period. Therefore, the timer means 100 delays the supply of the power supply voltage to the voltage detection means 12 at the next stage after the lighting until the power supply voltage stabilizes.

The voltage detecting means 12 inputs the power supply voltage at the time of stable lighting, rectifies and smoothes this, makes it a constant voltage, and outputs it.

On the other hand, as the lamp voltage at the time of lighting, the voltages from the output terminals c and d of the ballast 2 are taken out and supplied to the voltage detecting means 13. The voltage detection means 13 inputs the lamp voltage obtained at the output terminal of the ballast, rectifies and smoothes this, and outputs it.

Assuming that a lamp at the end of its life is used as the discharge lamp 4, the voltage generated by the voltage detecting means 12 is set by rectifying and smoothing the power supply voltage during stable lighting to make it a constant voltage. The voltage is a voltage that is set so as to correspond to the invariant part o-ad-bc of the ramp voltage waveform of FIG. 7B. The voltage generated by the voltage detecting means 13 is the ramp voltage waveform o-a-e-d-b- of FIG. 7 (b).
It is a voltage corresponding to what is obtained by rectifying and smoothing c.

In the comparing means 14, the difference between the voltage of the voltage detecting means 13 and the voltage of the voltage detecting means 12 is obtained. This difference voltage corresponds to a voltage obtained by integrating (rectifying and smoothing) the varying part of aed in FIG. 7B. The difference voltage from the comparison means 14 is supplied to the drive circuit 15, where it is compared with a threshold value. When the difference voltage is exceeded, a drive signal is output to the drive winding of the relay 16, Switch 16a
Turn off. That is, the drive circuit 15 of the switch means 150 detects that the variation of the lamp voltage is abnormally high, and at that time, the relay 16 is driven to turn off the power supply to the discharge lamp 4 and turn off the discharge lamp 4. . As a result, the discharge lamp 4 is automatically turned off when the lamp voltage abnormally rises due to electrode deformation that occurs at the end of life or the like, so that the abnormal heating state does not last for a long time, and after-effects such as lamp damage are prevented. be able to.

FIG. 2 shows an example of an illuminating device using the discharge lamp lighting device of FIG. FIG. 2 shows an example of a case where the above-mentioned discharge lamp lighting device is housed in a lighting fixture body to form a lighting device 40. A discharge lamp lighting device including a discharge lamp lighting device 42 and the discharge lamp 4 is housed in the lighting fixture body 41.

[0058]

According to the present invention, the abnormality of the lamp voltage waveform can be detected, and the AC power supply to the discharge lamp can be shut off. It is possible to realize a safe and highly reliable discharge lamp lighting device.

According to the second aspect of the present invention, when the high-voltage pulse necessary for starting the discharge lamp is generated and lit, the high-voltage pulse is detected and the high-voltage pulse generation is stopped, or after the high-voltage pulse is generated, there is no fixed time. If it is lighting, this is detected and the generation of the high-voltage pulse is stopped, so that a safe and energy-saving lighting circuit at the time of starting can be configured.

According to the invention of claim 4, at the time of starting the discharge lamp, 1.2 to 1.7 times as much lamp current as that at the time of stable lighting flows for several minutes. During this start-up period, the power supply voltage may drop significantly, so the detection by the second detection means should not be performed for several minutes until the discharge lamp reaches stable lighting.
As a result, the voltage waveforms are not compared in an unstable time zone, so that an abnormality can be detected in a stable period and a reliable lamp abnormality can be detected.

According to the invention of claim 6, the abnormality of the lamp voltage waveform due to the deformation of the electrode at the end of the life is detected and the supply of the AC power supply is cut off. Therefore, the abnormal heating of the electrode is prevented, and the life of the discharge lamp is prevented. It is possible to improve the end-stage safety.

According to the invention of claim 7, when it is used as a discharge lamp lighting device for a short arc type metal halide lamp with a narrow gap between opposed electrodes, abnormal heating due to electrode deformation can be prevented in advance, which is particularly useful.

According to the invention of claim 8, since the discharge lamp lighting device according to any one of claims 1 to 7 is provided in the main body of the lighting fixture, even if an abnormality occurs in the discharge lamp, the lighting device can be used as a lighting device. The safety of can be always ensured, and a highly reliable lighting device can be realized.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an example of a lighting device using the discharge lamp lighting device of FIG.

FIG. 3 is a block diagram showing a conventional discharge lamp lighting device.

FIG. 4 is a circuit diagram showing a configuration example of a ballast.

FIG. 5 is a circuit diagram showing a configuration example of a pulse circuit.

FIG. 6 is a view showing electrode states in a short arc type metal halide lamp at the beginning of use and at the end of life.

FIG. 7 is a waveform diagram showing lamp voltage waveforms corresponding to the initial use and the end of life of FIG.

[Explanation of symbols]

 1 ... AC power supply 2 ... Ballast 3 ... Pulse transformer 4 ... Discharge lamp 5 ... Current detection means (first detection means) 6 ... Pulse circuit 7 ... Switch 8 ... Control power supply 9 ... Pulse stop circuit 10 ... Timer 11 ... Switch 12 ... Voltage detecting means (second detecting means) 13 ... Voltage detecting means (third detecting means) 14 ... Comparison means 15 ... Drive circuit 16 ... Relay 30 ... Pulse generating means 80 ... Control means 100 ... Timer means 150 ... Switch means 400 ... Lighting circuit means 600 ... Safety circuit means

Claims (8)

[Claims] 1. An AC power supply; a discharge lamp to which this AC power supply is supplied; a stable lamp having an inductance interposed between the AC power supply and the discharge lamp to limit a current at the time of starting and lighting the discharge lamp. A high voltage pulse is generated between the discharge lamp and the ballast by the pulse transformer when the discharge lamp is started, and when the discharge lamp is lit, this is detected and the generation of the high voltage pulse is stopped. Lighting circuit means for stopping the generation of the high-voltage pulse by detecting this when the discharge lamp has not been lit for a certain period of time; and detecting the lamp voltage waveform of the discharge lamp when the discharge lamp is lit. A discharge lamp lighting device, comprising: safety circuit means for judging whether or not there is an abnormality, and shutting off power supply from the AC power source when it is judged to be abnormal. 2. The lighting circuit means is provided between the ballast and the discharge lamp, and when the discharge lamp is started, pulse generating means for generating a high-voltage pulse by a pulse transformer and supplying the high-voltage pulse to the discharge lamp. First detecting means for detecting a lighting state of the discharge lamp; operating based on a power supply voltage between the ballast and the pulse generating means, using a detection signal from the first detecting means 2. The discharge lamp lighting device according to claim 1, further comprising: control means for controlling ON / OFF of the high-voltage pulse generation of the pulse generation means. 3. The safety circuit means detects a voltage obtained by rectifying and smoothing a voltage waveform of the AC power supply when a discharge lamp is lit, and detects a voltage corresponding to an invariable portion of the lamp voltage waveform. Third detecting means provided between the ballast and the pulse generating means for detecting a voltage obtained by rectifying and smoothing the lamp voltage waveform of the discharge lamp;
Comparing means for obtaining the changed portion of the ramp voltage waveform by taking the difference between the output voltage of the third detecting means and the output voltage of the second detecting means; and the difference amount obtained from this comparing means exceeds a predetermined value. 2. The discharge lamp lighting device according to claim 1, further comprising: a switch unit that operates at the time of turning off to cut off the power supply from the AC power supply. 4. The safety circuit means, when it is detected that a certain time has passed after the discharge lamp was started,
The discharge lamp lighting device according to claim 3, further comprising timer means for causing the second detecting means to start an operation of detecting a voltage waveform of the AC power supply. 5. The switch means includes a detecting means for detecting whether or not the difference amount from the comparing means exceeds a predetermined value; a drive signal when the detecting means detects that the difference amount exceeds the predetermined value. 4. The discharge lamp lighting device according to claim 3, further comprising: a means for generating a power supply; and a relay for disconnecting power supply from the AC power supply based on the drive signal. 6. The safety circuit means detects an increase in the lamp voltage due to electrode deformation at the end of life of the lamp voltage waveform in the initial stage of the discharge lamp, and when the increase exceeds a predetermined range, the safety circuit means outputs the voltage from the AC power source. The discharge lamp lighting device according to claim 1, wherein the power supply of the device is cut off. 7. The discharge lamp lighting device according to claim 1, wherein the discharge lamp is a short arc type metal halide lamp. 8. A lighting device comprising: a lighting device main body; and the discharge lamp lighting device according to claim 1, which is housed in the lighting device main body.