JP2000106291A - Discharge lamp lighting device and luminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of lighting a discharge lamp without preheating, when a commercial AC power supply is shut off instantaneously, and to provide a luminaire. SOLUTION: This device includes a control circuit 6, designed so as to be capable of continuously controlling the action of switching elements FET1, FET2 and that after the electrodes 5a, 5b of a discharge lamp 5 are preheated, a discharge is brought about by varying the oscillating frequency of an oscillating circuit IC1 at the input of a commercial AC power supply Vs and a resetting circuit 7, which when the input of the commercial AC power supply Vs is shut off during the oscillating action of an inverter circuit 3, maintains the oscillating frequency of the oscillating circuit IC1 until the discharge of the discharge lamp 5 is extinguished and which at the application of the input after the extinction, operates the control circuit 5 so that continuous control is triggered.

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 apparatus and a lighting apparatus of a type in which a filament electrode of a discharge lamp is preheated and then a high voltage is applied to start and light the lamp.

[0002]

2. Description of the Related Art If a high voltage for starting lighting is applied without preheating a filament electrode of a discharge lamp, the discharge lamp deteriorates and its life is shortened. For this reason,
A discharge lamp lighting device is used in which a filament electrode is surely preheated and then a high voltage is applied to start and light the filament electrode. This type of discharge lamp lighting device is disclosed, for example, in Japanese Patent Application Laid-Open No. 7-272873 (prior art). This prior art discharge lamp lighting device 20 is shown in FIG.
As shown in the figure, the alternating current (A
C) A power supply 21, a DC circuit 22 including a bridge rectifier Rec1 and a smoothing electrolytic capacitor C18 for converting an alternating current into a direct current (DC), and a self-excited type for converting a direct current output from the direct current circuit 22 to a high frequency and outputting it. Inverter 23
And a resistor R24 and a capacitor C19 for starting the oscillation of the inverter 23 are connected in series between the output terminals of the DC circuit 22. Further, a discharge lamp 24 which is lit by the high frequency output from the inverter 23 and has a starting capacitor C20 connected in parallel, a timer circuit 25 for applying a high starting voltage after preheating the filament electrode of the discharge lamp 24, A reset circuit 26 for resetting the timer circuit 25 when the power is turned on, a detection circuit 27 for outputting a DC voltage based on a high-frequency voltage applied to the discharge lamp 24, and an inverter 23 based on the detection voltage from the detection circuit 27. Output control circuit 2 for controlling high-frequency output from
8 are provided.

When the power switch SW is turned on, the DC voltage is rectified and smoothed by the DC circuit 22 to form a DC voltage. The DC voltage is supplied to the capacitor C via a resistor R24.
Charge 19 When the voltage between both ends of the capacitor C19 rises, the voltage becomes the transistor Tr of the reset circuit 26.
2 and the transistor Tr2 is turned on (conducting). When the transistor Tr2 is turned on, the capacitor C21 of the timer circuit 25 is grounded, and its voltage becomes zero.
V. When the inverter 23 starts oscillating, the voltage across the capacitor C19 becomes 0 V, and at the same time, the transistor Tr2 of the reset circuit 26 is turned off. Thereafter, a preheating operation and a high-voltage high-frequency output are applied as a starting voltage to the discharge lamp 24 to perform a lighting operation.

[0004]

The prior art discharge lamp lighting device 20 is capable of controlling the capacitor C21 of the timer circuit 25 even when the power switch SW is turned on / off in a short time or when the AC power supply 21 is momentarily interrupted. The reset for discharging the residual charge secures the charging / discharging time of the time constant of the resistor R25 and the capacitor C21 and the preheating time determined by the set voltage of the Zener diode ZD2, and ensures the preheating of the filament electrode of the discharge lamp 24. After that, a high starting voltage is applied. However, even when the power switch SW is turned on / off in a short time or when the AC power supply 21 is momentarily interrupted, returning to the initial preheating and re-lighting the discharge lamp 24 means that the discharge lamp 24 is turned off during this time. As a result, the illumination is hindered, and the filament electrode is wasted even though it is already heated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a discharge lamp lighting device and a lighting fixture capable of lighting a discharge lamp without preheating when a commercial AC power supply is momentarily interrupted. I do.

[0006]

According to the present invention, there is provided a discharge lamp lighting device, comprising: a DC power supply circuit for rectifying or rectifying and smoothing a commercial AC power supply; An inverter circuit including oscillating means for converting to high frequency; energized by high frequency;
A discharge lamp with a preheating electrode; when the commercial AC power is turned on, by changing the oscillation frequency of the oscillating means, the operation of the switch element can be controlled so that discharge occurs after preheating the electrode of the discharge lamp When the input of the commercial AC power supply is interrupted during the oscillating operation of the inverter circuit, the oscillation frequency of the oscillating means is maintained until the discharge of the discharge lamp extinguishes; Means for operating the control means so as to start the continuous control when is input.

When the commercial AC power is turned on, the control means changes the oscillation frequency of the oscillating means to the preheating, starting and lighting frequencies. The inverter circuit outputs an output in accordance with the oscillation frequency to preheat the preheating electrode of the discharge lamp, and then applies a starting voltage so as to generate a discharge in the discharge lamp and turns on the discharge lamp. When the input of the commercial AC power supply is cut off during the oscillating operation of the inverter circuit, the oscillation frequency of the oscillating means is maintained until the discharge of the discharge lamp extinguishes. To turn on the discharge lamp. When the input of the commercial AC power is turned on after the occurrence of the discharge lamp extinguishment, the control means operates the control means to control the oscillating means of the inverter circuit so that the discharge lamp is continuously preheated, started, and lit. Control the oscillation frequency.

When the input of the commercial AC power supply is cut off during the oscillation operation of the inverter circuit, and when the input of the commercial AC power supply is turned on until the discharge of the discharge lamp disappears, the discharge lamp is continuously operated. Since the lamp is turned on, turning off of the discharge lamp is prevented. In addition, when the input of the commercial AC power is turned on after the discharge lamp has extinguished, the preheating electrode of the discharge lamp is preheated to start lighting, thereby preventing the deterioration and short life of the discharge lamp.

According to a second aspect of the present invention, there is provided a lighting apparatus comprising: the discharge lamp lighting device according to the first aspect; and a lighting fixture main body accommodating the discharge lamp lighting device.

When the input of the commercial AC power supply is interrupted during the oscillation operation of the inverter circuit, or when the input of the commercial AC power supply is applied before the discharge of the discharge lamp stops, the discharge lamp is continuously operated. Since the discharge lamp lighting device for lighting is provided, it is possible to provide a lighting fixture that can prevent the discharge lamp from being turned off due to the preheating operation when the commercial AC power supply stops momentarily.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram of a discharge lamp lighting device according to a first embodiment of the present invention. In the figure, 1 is a discharge lamp lighting device, 2 is a DC power supply circuit, 3 is an inverter circuit,
4 is a power supply circuit, 5 is a discharge lamp, 6 is a control circuit, and 7 is a reset circuit.

The DC power supply circuit 2 includes a series connection of electrolytic capacitors C1 and C2 for smoothing and diodes D1 and D2 connected in series.
AC power supply Vs is connected between the connection point a of the capacitor C1 and the connection point b of the electrolytic capacitors C1 and C2 by the fuse F1
1, a varistor VA1 and a transformer T1 are connected via a filter circuit. Both ends of the series circuit of the electrolytic capacitors C1 and C2 are the output side of the DC power supply circuit 2, and the commercial AC power supply Vs is voltage-rectified and smoothed and output to the inverter circuit 3. Electrolytic capacitor C2
Negative side (the anode side of diode D2) c is ground E
It is connected to the. The ground E is connected to the power supply line m of the control circuit 6.

The inverter circuit 3 includes field effect transistors FET1 and FE as switch elements connected in series.
T2 and an integrated circuit IC1 as an oscillating means. Field effect transistors FET1, FE
The connection point d of T2 is connected to the seventh terminal of the integrated circuit IC1. Then, the field effect transistors FET1 and F
Each gate of ET2 is connected to the sixth and eighth terminals of the integrated circuit IC1 via gate resistors R1 and R2, respectively. Field effect transistors FET1, FET2
Are connected between resistors R3 and R4, respectively. The resistors R3 and R4 form the gate voltages of the field effect transistors FET1 and FET2. Further, a capacitor C for preventing noise is provided between each drain and source of the field effect transistors FET1 and FET2.
4 and C5 are connected.

A diode D3 is connected between the first and fifth terminals of the integrated circuit IC1, and a capacitor C6 is connected between the fifth and seventh terminals to constitute a switch power supply on the high side. I have. The capacitor C7 is connected between the first and fourth terminals, and the fourth terminal is connected to the source (earth E) of the field effect transistor FET2. Terminal 2 and power line m of control circuit 6 (Earth E)
A series circuit of the resistors R5 and R6, the variable resistor R7, and the capacitor C15 of the control circuit 6 is connected between them. The third terminal is connected to a connection point e between the variable resistor R7 and the capacitor C15. Note that, in parallel with the capacitor C15, a series circuit of the capacitor C16 and the diode D6,
A series circuit of a capacitor C17 and a diode D7 is connected.

The integrated circuit IC1 turns on and off the field effect transistors FET1 and FET2 as switching elements, and sets the oscillation frequency at which the on and off operations are performed by a resistor R
5, R6, R7 and the capacitor C1 in the control circuit 6.
5, is changed by the time constant of C16 and C17.
That is, the oscillation frequency is changed when the discharge lamp 4 is preheated, started, or turned on. When the integrated circuit IC1 turns on and off the field effect transistors FET1 and FET2, the output of the DC power supply circuit 2 is converted to a high frequency.

The power supply circuit 4 has an output side of the inverter circuit 3,
That is, it is connected to both ends of the field effect transistor FET2. At both ends of the field effect transistor FET2,
R connected in parallel with the capacitor C8 and the diode D4
8 and R9 are connected, a connection point f between the capacitor C8 and the diode D4, and a field effect transistor FE.
A series circuit of a diode D5 and a smoothing electrolytic capacitor C9 is connected between the source (earth E) of T2. And a connection point g between the diode D5 and the electrolytic capacitor C9.
Are connected to the power supply line l of the control circuit 6.

When the inverter circuit 3 operates, the power supply circuit 4 causes a current to flow through the path of the capacitor C8, the diode D5 and the electrolytic capacitor C9, and charges the electrolytic capacitor C9 to generate a voltage at the connection point g. This voltage is supplied to the control circuit 6.

The output side of the inverter circuit 3 is connected to a discharge lamp 5 via a DC cut capacitor C10 and an inductor L1 as a current limiting element. The filament electrodes 5a and 5b of the discharge lamp 5
10, R11 are connected to the filament windings L1a, L1b of the inductor L1. The starting capacitor C11 is connected in parallel with the discharge lamp 5.

The discharge lamp 5 is, for example, a 25 W fluorescent lamp provided with a preheating electrode, and is energized by the high frequency power output from the inverter circuit 3. The filament electrodes 5a and 5b of the discharge lamp 5 are always preheated as long as a high-frequency current flows through the inductor L1. The starting capacitor C11 resonates with the inductor L1 and starts the discharge lamp 5 with the resonance voltage at the time of starting.

A Zener diode ZD1, an electrolytic capacitor C12, a series circuit of resistors R11, R12 and R13, a series circuit of a resistor R14 and an electrolytic capacitor C13, and a capacitor C14 are provided between the power supply lines 1 and m of the control circuit 6 and the reset circuit 7. And a series circuit of a resistor R15. The power line l is connected to the resistors R16, R17,
A resistor R19 is connected in parallel with the connection point b of the DC power supply circuit 2 through the series circuit of R18 and in parallel with the electrolytic capacitor C1 of the DC power supply circuit 2, and the connection point b side is connected to the resistor R20.
Connected through. Further, the power supply line 1 is connected to a connection point g between the diode D5 of the power supply circuit 4 and the capacitor C9.
It is connected to the. The power line m is connected to the ground E. Between the power supply lines l and m, resistors R11 and R1
2, among the AC voltages input via R13, a DC voltage higher than the set voltage is input by the Zener diode ZD1, and the output voltage of the DC power supply circuit 2 is input via the resistor R20. The output voltage of the inverter circuit 3 is input via the connection point g of the power supply circuit 4.

At both ends of the electrolytic capacitor C12 of the control circuit 6, an integrated circuit I incorporating error amplifiers OP1 and OP2 is provided.
C2 is connected, and the integrated circuit IC2 is an electrolytic capacitor C1.
2 power. The reference terminal of the error amplifier OP1 is connected to a connection point h between the resistors R12 and R13, and the reference terminal of the error amplifier OP2 is connected to a connection point k between the resistors R11 and R12. And error amplifiers OP1 and O
The comparison terminal of P2 is connected to the connection point n of the resistor R14 and the electrolytic capacitor C13 via the resistors R21 and R22, respectively. The resistor R13 is connected to the reference terminal of the error amplifier OP1.
Is input to the reference terminal of the error amplifier OP2, and the voltage across the series circuit of the resistor R12 and the resistor R13 is input. Then, the voltage between both ends of the electrolytic capacitor C13 is input to the comparison terminals of the error amplifiers OP1 and OP2 via the resistors R21 and R22, respectively.

The output terminal of the error amplifier OP1 is connected to the connection point o between the capacitor C17 and the diode D7, and the output terminal of the error amplifier OP2 is connected to the reverse-connected diode D
8 is connected to a connection point p between the capacitor C16 and the diode D6. A resistor R23 for preventing hunting is connected between the reference terminal and the output terminal of the error amplifier OP2. The output terminals of the error amplifiers OP1 and OP2 are
When the voltage difference between the voltage input to the reference terminal and the voltage input to the comparison terminal reaches a predetermined value, the power supply line m (ground E) is connected in the integrated circuit IC2. That is, when the reference voltage of the error amplifier OP1 (the voltage across the resistor R13) and the voltage across the capacitor C13 input to the comparison terminal have a predetermined voltage difference, the output terminal is connected to the power supply line m, and the capacitor C17 is connected to the capacitor C15. Are connected in parallel. Further, the reference voltage of the error amplifier OP2 (the resistor R12
When the voltage across the capacitor C13 input to the comparison terminal has a predetermined voltage difference, the output terminal is connected to the power supply line m (earth E), and the capacitor C16 is connected to the capacitors C15 and C15. It is connected in parallel with the capacitor C16.

The connection point q between the capacitor C14 and the resistor R15 of the reset circuit 7 is connected to the base of the transistor Tr1, and the emitter of the transistor Tr1 is connected to the power supply line m.
(Earth E), the collector is connected to a connection point n between the resistor R14 of the control circuit 6 and the electrolytic capacitor C13. When the transistor Tr1 is turned on, the electrolytic capacitor C13
Are short-circuited, and the electric charge stored in the electrolytic capacitor C13 is discharged to the ground E.

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

When the commercial AC power supply Vs is turned on, the DC power supply circuit 2 generates a DC voltage and inputs it to the inverter circuit 3. In addition, the resistors R16 to
Power is supplied between the power supply lines 1 and m of the control circuit 6 and the reset circuit 7 from the output side via the resistor R20 via R18. Then, the electrolytic capacitor C12 is charged, and the charged voltage is supplied to the integrated circuit IC2 as drive power,
The integrated circuit IC2 operates. Further, current flows through the resistor R15 and the base and the emitter of the transistor Tr1 via the capacitor C14 of the reset circuit 7, and the transistor Tr1 is turned on. When the transistor Tr1 turns on,
The electrolytic capacitor C13 of the control circuit 6 is short-circuited and the resistance R
The connection point n between 14 and the electrolytic capacitor C13 is connected to the ground E. As a result, a zero voltage is input to the comparison terminals of the error amplifiers OP1 and OP2. The DC voltage supplied between the power lines l and m is divided by the resistors R11, R12 and R13, and the voltage across the resistor R13 is changed to the error amplifier OP.
1 and is supplied to the reference terminals of the resistors R12 and R13.
Is input to the reference terminal of the error amplifier OP2. The integrated circuit IC of the inverter circuit 3
A series circuit of resistors R6, R7, R8 and a capacitor C15 is connected between the second terminal 1 and the power supply line 1 (earth E). The integrated circuit IC1 changes the oscillation frequency according to the time constant of the series circuit to the preheating frequency (for example, 80 KH).
z), the field-effect transistors FET1 and FET2 are turned on and off during a preheating period (for example, 0.6 to 0.8 seconds). The inverter circuit 3 applies a high-frequency voltage generated by chopping according to the preheating frequency to the discharge lamp 5 via the DC cut capacitor C10 and the inductor L1. The filament electrodes 5a and 5b of the discharge lamp 5 are preheated by preheating voltages generated at both ends of the filament windings L1a and L1b.

Thereafter, the capacitor C1 of the reset circuit 7
When 4 is charged, no current flows to the base of the transistor Tr1, and the transistor Tr1 is turned off. When the transistor Tr1 is turned off, the electrolytic capacitor C13 is connected between the power supply lines 1 and m via the resistor R14, charged, and the voltage at both ends gradually increases. When the voltage difference between the voltage across the resistor R13 and the voltage across the electrolytic capacitor C13 reaches a predetermined value, the error amplifier OP1 connects its output terminal and the power supply line m within the integrated circuit IC2. as a result,
Capacitor C17 is connected in parallel with capacitor C15. The integrated circuit IC1 of the inverter circuit 3 includes resistors R6, R7, R8 and a capacitor C connected in parallel.
The oscillation frequency is set to a starting frequency (for example, 65 to 70 KHz) by the time constant of the series circuit with the C15 and C17, and the field-effect transistors FET1 and FET2 are turned on and off for a starting period (for example, 0.2 seconds). The inverter circuit 3 outputs a high-frequency voltage generated by chopping according to the starting frequency to the discharge lamp 5 via the DC cut capacitor C10 and the inductor L1. Discharge lamp 5
Is applied with a resonance voltage by the inductor L1 and the starting capacitor C11, and the discharge lamp 5 is started.

When the voltage across the electrolytic capacitor C13 further rises and the voltage difference between the voltage across the series circuit of the resistor R12 and the resistor R13 reaches a predetermined value, the error amplifier OP2 integrates its output terminal and the power supply line m. The connection is made in the circuit IC2. As a result, the capacitor C16 becomes the capacitor C1.
5 and the capacitor C17. And
The integrated circuit IC1 of the inverter circuit 3 includes resistors R6, R
7, R8 and capacitors C15, C1 connected in parallel
6, the oscillation frequency is set to the lighting frequency (for example, 23 KHz) by the time constant of the series circuit with C17, and the field effect transistors FET1 and FET2 are turned on and off.
The inverter circuit 3 converts a high frequency voltage generated by chopping according to the lighting frequency into a DC cut capacitor C10.
And the output to the discharge lamp 5 via the inductor L1,
The discharge lamp 5 continues lighting. When the inverter circuit 3 operates, the output voltage of the inverter circuit 3 changes to the connection point g of the power supply circuit 4.
The power is supplied between the power supply lines 1 and m.

When the input of the commercial AC power supply Vs is interrupted while the discharge lamp 5 is lit, that is, during the oscillating operation of the inverter circuit 3, the output voltage of the DC power supply circuit 2 discharges the electrolytic capacitors C1 and C2. Decreases gradually. Further, the electrolytic capacitor C12 of the control circuit 6 is also discharged by the operation of the integrated circuit IC2, and the voltage between both ends gradually decreases. Further, the capacitor C14 of the reset circuit 7 is connected to the resistor R15.
Discharges the charge. If the output voltage of the DC power supply circuit 2 continues to decrease, the output voltage of the inverter circuit 3 also decreases, and the lighting of the discharge lamp 5 cannot be maintained.
Turns off after seconds. Then, the oscillation operation of the integrated circuit IC1 also stops, for example, 0.8 seconds after the interruption of the commercial AC power supply Vs, and the voltage across the electrolytic capacitor C12 also drops, so that the integrated circuit IC2 cannot be driven. When the discharge lamp 5 is turned off, the capacitor C14 and the resistor R15 are set in advance so that the capacitor C14 is discharged to such an extent that a current can flow between the base and the emitter of the transistor Tr1 of the reset circuit 7.

Thereafter, when the commercial AC power supply Vs is turned on, the discharge lamp 5 is preheated, started and lit again as described above. FIG. 2 shows a flowchart of the operation. In the figure, Vc
c is the voltage between the power supply lines 1 and m, Il is the lamp current, I
d is the drain current of the switching elements FET1 and FET2,
Vdc is the output voltage of the DC power supply circuit 2, F is the oscillation frequency,
T1 is a period from the interruption of the commercial AC power supply Vs to the disappearance of the discharge lamp 5, and T2 is a period from the interruption of the commercial AC power supply Vs to the stop of the oscillation of the integrated circuit IC1. The restart of the commercial AC power supply Vs is within the period T2,
It is the same flow figure even after a T2 period passes. The voltages of Vdc and Vcc gradually decrease after the interruption of the commercial AC power supply Vs, but return immediately after the commercial AC power supply Vs is turned on again. The lamp current Il flows when a discharge occurs between the filament electrodes 5a and 5b of the discharge lamp 5. The oscillating frequency F is maintained until the period T2, and the respective oscillating frequencies are set to the integrated circuit IC1 during preheating, starting and lighting.
Oscillated by The drain current Id flows during the period T2 after the interruption of the commercial AC power supply Vs, stops flowing when the oscillation of the integrated circuit IC1 is stopped, and flows in accordance with the respective oscillation frequencies during preheating, starting, and lighting.

After the input of the commercial AC power supply Vs is cut off,
Before the discharge lamp 5 extinguished, the capacitor C14 was not discharged to the extent that current could flow between the base and the emitter of the transistor Tr1 of the reset circuit 7, so the input of the commercial AC power supply Vs was turned on again. At this time, the transistor Tr1 is kept off. If the transistor Tr1 is off, the capacitors C15 and C1
6 and C17 are connected in parallel, the integrated circuit IC1 of the inverter circuit 3 sets the oscillation frequency to the lighting frequency (for example, 23 KHz) and sets the field effect transistor FET
1, FET2 is turned on and off. That is, the discharge lamp 5 does not go out and continues lighting. FIG.
2 shows a flowchart when the input of the commercial AC power supply Vs is turned on again before the discharge lamp 5 goes out in the same manner as FIG. Before the discharge lamp 5 goes out, the commercial AC power supply V
When the input of s is turned on again, there is an instantaneous interruption of the commercial AC power supply Vs. The voltages of Vdc and Vcc gradually decrease after the interruption of the commercial AC power supply Vs, but return immediately after the commercial AC power supply Vs is turned on again. Also, the lamp current Il
The drain current Id gradually decreases after the commercial AC power supply Vs is cut off, but recovers immediately after the commercial AC power supply Vs is turned on again.

As described above, the energization of the discharge lamp 5 of the inverter circuit 3 differs depending on whether the transistor Tr1 of the reset circuit 7 is turned on or off when the commercial AC power supply Vs is turned on. That is, when the commercial AC power supply Vs is turned on and the transistor Tr1 is turned on, the discharge lamp 5 is started and lit by preheating the filament electrodes 5a and 5b. If the transistor Tr1 is off when the commercial AC power supply Vs is turned on, the discharge lamp 5 lights up without preheating the filament electrodes 5a and 5b. Thus, the reset circuit 7
When the input of the commercial AC power supply Vs is cut off during the oscillation operation of the inverter circuit 3, the oscillation frequency of the integrated circuit IC1 as the oscillating means is maintained until the discharge of the discharge lamp 5 stops. Is a means for operating the control circuit 6 as a control means so as to start the continuous control, that is, the preheating, starting, and lighting.

When the input of the commercial AC power supply Vs is interrupted during the oscillating operation of the inverter circuit 3 or when the input of the commercial AC power supply Vs is turned on until the discharge of the discharge lamp 5 disappears, the discharge lamp 5, the discharge lamp 5 is prevented from being turned off, and when the input of the commercial AC power supply Vs is turned on after the discharge lamp 5 goes out, the filament electrodes 5a and 5b of the discharge lamp 5 are preheated. As a result, the discharge lamp 5 can be prevented from deteriorating and having a short life.

FIG. 4 is an external view of a lighting fixture showing a second embodiment of the present invention.

The lighting fixture 8 shown in FIG.
Lamp sockets 10, 10 are provided at both ends of the lower surface of the
A fluorescent lamp 11 as a discharge lamp is sandwiched and connected between the lamp sockets 10. Further, a reflection surface 12 is formed so as to be optically opposed to the fluorescent lamp 11, and a discharge lamp lighting device 1 except for the discharge lamp 5 shown in FIG. Lighting equipment 8
Is directly attached to a ceiling surface (not shown) or the like.

When the input of the commercial AC power supply Vs is cut off and the input of the commercial AC power supply Vs is turned on until the discharge of the fluorescent lamp 11 stops, the fluorescent lamp 1 is turned off.
Since the discharge lamp lighting device 1 for continuously lighting the discharge lamp 1 is provided, it is possible to provide the lighting fixture 8 that can prevent the discharge lamp from being turned off due to the preheating operation when the commercial AC power supply Vs momentarily stops.

[0037]

According to the first aspect of the present invention, when the input of the commercial AC power supply is interrupted during the oscillation operation of the inverter circuit, the oscillation frequency of the oscillation means is maintained until the discharge of the discharge lamp stops. When the input is turned on after the extinguishment has occurred, the control means is operated to start the continuous control.Therefore, when the input of the commercial AC power supply is cut off, It is possible to provide a discharge lamp lighting device capable of continuously lighting the discharge lamp when the input of the commercial AC power is turned on until the discharge stops.

According to the second aspect of the present invention, when the input of the commercial AC power is cut off and the input of the commercial AC power is turned on until the discharge of the fluorescent lamp stops, the fluorescent lamp is continued. Since the discharge lamp lighting device for turning on the discharge lamp is provided, it is possible to provide a lighting fixture capable of preventing the discharge lamp from being turned off due to the preheating operation when the commercial AC power supply stops momentarily.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a discharge lamp lighting device according to a first embodiment of the present invention.

FIG. 2 is a flow chart in turning on a commercial AC power supply.

FIG. 3 is a flow chart of the instantaneous interruption of the commercial AC power supply.

FIG. 4 is an external view of a lighting device according to a second embodiment of the present invention.

FIG. 5 is a circuit diagram of a conventional discharge lamp lighting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Discharge lamp lighting device 2 ... DC power supply circuit 3 ... Inverter circuit 5 ... Discharge lamp 6 ... Control circuit as control means 7 ... Reset circuit as means for operating control means 8 ... Lighting equipment 9 Lighting fixture body

Claims (2)

[Claims] A DC power supply circuit for rectifying or rectifying and smoothing a commercial AC power supply;
An inverter circuit including an oscillating means for converting the output of the DC power supply circuit to a high frequency; a discharge lamp energized by the high frequency and having a preheating electrode; and changing an oscillating frequency of the oscillating means when a commercial AC power is turned on. Control means configured to control the operation of the switch element so that a discharge occurs after preheating the electrodes of the discharge lamp;
When the input of the commercial AC power supply is cut off during the oscillation operation of the inverter circuit, until the discharge of the discharge lamp goes out,
Means for maintaining the oscillating frequency of the oscillating means and operating the control means so as to start the continuous control when the input is turned on after the occurrence of the extinguishment. Lamp lighting device. 2. The discharge lamp lighting device according to claim 1,
A lighting fixture housing the discharge lamp lighting device;