JPH07142181A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To provide a simplified discharge lamp lighting device making protection against an abnormality, capable of improving startability, and easy to design without increasing the output of an inverter circuit or without increasing, decreasing, or stopping the output of a chopper circuit. CONSTITUTION:This discharge lamp lighting device is provided with a rectifying means DB, the first power circuit DN1, a smoothing means C0, the second power circuit DN2, a lamp lighting circuit TN,, a discharge lamp DL1, a detecting circuit KN1, the first and second judging circuits HN3, HN4, and the first and second control circuits SE1, SE.2 The output of the first power circuit DN1 is controlled by the first control circuit SE1 in response to the output of the first judging circuit HN3 so that the discharge lamp DL1 is sufficiently preheated. The output of the second power circuit DN2 is controlled by the second control circuit SE2 in response to the output of the second judging circuit HN4 to suppress the lighting power to the discharge lamp DL1.

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 lighting a discharge lamp with a filament such as a fluorescent lamp, and more particularly to a discharge lamp lighting device which guarantees a start and protects against abnormal conditions. .

[0002]

2. Description of the Related Art Conventionally, a discharge lamp lighting device using a chopper circuit and an inverter circuit is well known as a device for starting and lighting a discharge lamp. FIG. 6 shows a configuration example of the first conventional example. As shown in FIG. 6, this discharge lamp lighting device rectifies an AC power supply AC by a rectifying means DB composed of a diode bridge, and the resulting pulsating current DC voltage is supplied to a first power supply circuit DN ₁ , a so-called chopper circuit and a rectifier. The DC-DC converter circuit is composed of a DC-DC converter circuit that converts the DC voltage into a certain set value, and further smoothes it with a smoothing means C ₀ that is a capacitor provided at the output of the first power supply circuit DN ₁ The second power supply circuit DN ₂ , which is a so-called inverter circuit, is operated by using the voltage (charging voltage of the capacitor as the smoothing means C ₀ ) as a power supply, and the high frequency output of the _second power supply circuit DN ₂ is passed through the lamp lighting circuit TN ₁ . discharge lamp is supplied to the DL _1, and starting to light the discharge lamp DL ₁ Te.

The first power supply circuit DN ₁ is provided with a _first control circuit SE ₁ for controlling its operation, and the second power supply circuit DN ₂ is provided with a second control circuit SE ₂ for controlling its operation. It is provided. In addition, the discharge lamp DL is connected to the lamp lighting circuit TN ₁ which is a load circuit of the second power supply circuit DN _2.
The detection circuit KN ₁ for detecting the state of ₁ is built in,
For example, the voltage (lamp voltage) applied to both ends of the discharge lamp DL ₁ is detected.

Further, the decision circuit HN₁Is the detection circuit KN₁
The discharge lamp DL with the output signal of₁The state of
Separately, the second control circuit SE₂Change the behavior of the second
Power supply circuit DN₂The output of is suppressed. This second control
Circuit SE₂Is the second power supply circuit DN₂Switching element
The decision circuit HN controls the on / off operation of the child. ₁
According to the output signal of the discharge lamp DL₁Detected anomalies in
Second power supply circuit DN₂The inverter circuit is abnormal
State, that is, when half-wave discharge or no load occurs,
The resonance circuit of the output circuit is out of the resonance condition, resulting in abnormal voltage or abnormal
The current is the switching element of the inverter circuit, or
Prevent it from flowing into the arc coil or resonance capacitor
It protects these elements.

The first control circuit SE ₁ controls switching of the chopper circuit of the _first power supply circuit DN ₁ . In the first conventional example of FIG. 6 as described above, when the discharge lamp DL ₁ is abnormal, the output of the inverter circuit which is the second power supply circuit DN ₂ is suppressed to reduce the stress of the elements forming the inverter circuit. However, on the contrary, the discharge lamp DL ₁ may be placed at a low temperature, or the characteristics of the discharge lamp DL ₁ may vary, or the like.
_{When a} high lamp voltage of ₁ is added, it is necessary to increase the output of the inverter circuit. In other words, assuming a higher output in advance than the design of a predetermined output, a component with a high grade rating is required, and the cost increases, and the inverter operation also controls the switching element by, for example, on-duty control. In such a case, there is a drawback that the stress of the switching element is increased in order to control the width to be wider than a predetermined ON width. The same can be said for other control methods.

Further, in the first conventional example of FIG. 6, the second power supply circuit DN ₂ is composed of a starter circuit and a drive circuit of an inverter circuit in order to simplify the circuit structure.
Power supply circuit DN ₁ does not operate for a predetermined time when the power is turned on,
When the discharge voltage of the smoothing means C ₀ is lower than the predetermined voltage and the output of the inverter circuit is also low, the starting voltage of the discharge lamp DL ₁ is not reached and only the filament is preheated. The power supply circuit DN ₁ operates and the smoothing means C
_When the charging voltage of ₀ becomes a predetermined voltage, the discharge lamp DL
_It has a simple circuit configuration in which ₁ is started and turned on, that is, a so-called preheating operation is performed by utilizing the operating time of the first power supply circuit DN ₁ . However, there is a problem as described above, and by taking this measure, there is a drawback that the above-described simplified and cost-reduced circuit increases the cost.

[0007]

[Problems to be Solved by the Invention]
What was considered was the second conventional example shown in FIG. this
In the discharge lamp lighting device of FIG. 7, the difference from FIG. 6 is discharge.
Lamp DL₁Abnormality judgment circuit HN₂Judgment with
Power supply circuit DN₁Trying to control a so-called chopper circuit
It is something. The operation of this circuit will be
Source circuit DN₂The output of the inverter circuit is
In order to reduce the output voltage of the chopper circuit,
is there. Alternatively, the chopper circuit may be stopped and the inverter
This is to reduce the power supply voltage of the data circuit.
For this purpose, the first control circuit SE₃Judgment circuit HN₂of
The output signal is supplied to the second control circuit SE_FourJudgment circuit
HN ₂The output signal of is not supplied. Other
Is the same as that of FIG.

With this structure, the inverter circuit is protected. However, the operation of lowering the output voltage of the chopper circuit or stopping the chopper circuit is the original purpose of the chopper circuit. -DC
Contrary to the conversion and the purpose of improving the distortion of the input current of this discharge lamp lighting device and providing a power supply circuit with a power factor close to 1, by lowering the output voltage of the chopper circuit, the input distortion becomes worse, Even if it is abnormal, by stopping it, the original purpose of the chopper circuit is not achieved while the suppression lighting is on. On the other hand, when trying to increase the output of the inverter circuit, increasing the chopper output voltage can be considered immediately, but this increases the stress on the inverter circuit components and requires high-rated components, which reduces the cost. As a result, the problem described in FIG. 6 remains.

Therefore, the first one as shown in FIG. 6 and FIG.
In the discharge lamp lighting device having the power supply circuit DN ₁ and the second power supply circuit DN ₂ , abnormal protection due to the end of life of the discharge lamp DL ₁ or no load, and at the same time when the ambient temperature of the discharge lamp DL ₁ is low, A measure for improving the startability of the discharge lamp due to variations in the discharge of the lamp DL is taken without causing the above-mentioned problem, that is, the output of the inverter circuit is increased, or the output of the chopper circuit is increased. Alternatively, it is desired to perform abnormal protection and improve startability without reducing or stopping.

An object of the present invention is to provide a first power supply circuit and a second power supply circuit.
Clarify the division of the function of the power supply circuit, protect the abnormalities without increasing the output of the inverter circuit or increasing, decreasing, or stopping the output of the chopper circuit, and startability. An object of the present invention is to provide a discharge lamp lighting device that can be improved, is easy in design, and is simplified.

[0011]

According to a first aspect of the present invention, there is provided a discharge lamp lighting device comprising: rectifying means for converting an AC power supply into a pulsating direct current voltage; and a pulsating direct current voltage supplied from the rectifying means. A first power supply circuit for stepping down, a first control circuit for controlling the first power supply circuit, a smoothing means provided at an output portion of the first power supply circuit, and a first power supply circuit A second power supply circuit that generates a high frequency output by using the smoothed DC voltage as a power supply input, a second control circuit that controls the second power supply circuit, and a filament that receives power supply from the second power supply circuit. Lamp lighting circuit that lights the discharge lamp, a detection circuit that is provided in this lamp lighting circuit to detect the voltage between both electrodes of the discharge lamp, and the voltage detected by this detection circuit is used for preheating the discharge lamp. Sufficient first reference voltage A first determination circuit that determines a lower voltage, and a second determination circuit that determines that the voltage detected by the detection circuit is higher than a first reference voltage is higher than a second reference voltage with which a discharge lamp can be stably lit. And a determination circuit of
In response to the output of the first determination circuit, the first control circuit controls the output of the first power supply circuit so that the discharge lamp is preheated sufficiently, and in response to the output of the second determination circuit. The output of the second power supply circuit is controlled by the second control circuit so as to suppress the electric power for lighting the discharge lamp.

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 first power supply circuit is a boost type, and the first power supply circuit is turned on for a predetermined time after the AC power is turned on. In a non-operating state, the low-voltage pulsating current DC voltage supplied from the rectifying means is supplied to the second power supply circuit via the smoothing means to keep the output voltage of the second power supply circuit at a voltage lower than the starting voltage of the discharge lamp. The discharge lamp is preheated in advance, and after a lapse of a predetermined time, the first power supply circuit is put into an operating state and the high-voltage DC voltage output from the first power supply circuit is set to the second value.
Is supplied to the power supply circuit of the second power supply circuit to increase the output voltage of the second power supply circuit to start the discharge lamp and raise the lighting, and in response to the output of the first determination circuit, the first control circuit controls the AC power supply. The non-operation time of the first power supply circuit after being turned on is extended.

A discharge lamp lighting device according to a third aspect of the present invention is the discharge lamp lighting device according to the first aspect, wherein control power is supplied from the first power supply circuit to the second control circuit. The second power supply circuit is operated in response to the operation of, and the output of the first power supply circuit is limited for a predetermined time after the AC power is turned on to supply a low-voltage DC voltage to the second power supply circuit. The output voltage of the second power supply circuit is kept lower than the starting voltage of the discharge lamp to preheat the discharge lamp, and after the elapse of a predetermined time, the output of the first power supply circuit is increased to increase the second power supply circuit. A high-voltage DC voltage to increase the output voltage of the second power supply circuit to start and light the discharge lamp, and in response to the output of the first determination circuit,
The control circuit described above extends the output suppression time of the first power supply circuit after the AC power is turned on.

[0014]

According to the structure of claim 1, when the voltage applied to both ends of the discharge lamp is lower than the first reference voltage sufficient for preheating the discharge lamp before starting, the first control circuit controls the discharge lamp. The output of the first power supply circuit is controlled so that the preheating is sufficiently performed. Further, after lighting, when the voltage applied to both ends of the discharge lamp is higher than the second reference voltage with which the discharge lamp can be stably lit, the second control circuit suppresses lighting power to the discharge lamp. Second
The output of the power supply circuit is controlled.

According to the second aspect of the present invention, the output voltage of the second power supply circuit is set to a voltage lower than the starting voltage of the discharge lamp for a predetermined time after the AC power supply is turned on and the first power supply circuit is in the inoperative state. Keep the discharge lamp at a high level and preheat the discharge lamp. After the elapse of a predetermined time, the first power supply circuit is activated and the high-voltage DC voltage output from the first power supply circuit is supplied to the second power supply circuit to increase the output voltage of the second power supply circuit. To start and turn on the discharge lamp. Before starting, the voltage applied across the discharge lamp is sufficient to preheat the discharge lamp.
When the voltage is lower than the reference voltage of
Extend the down time of the power supply circuit.

According to the third aspect of the present invention, the output of the first power supply circuit is limited and the low-voltage DC voltage is supplied to the second power supply circuit for a predetermined time after the AC power supply is turned on. The output voltage of the power supply circuit is maintained at a voltage lower than the starting voltage of the discharge lamp to preheat the discharge lamp. After the elapse of a predetermined time, the output of the first power supply circuit is increased and a high-voltage DC voltage is supplied to the second power supply circuit to increase the output voltage of the second power supply circuit to start and light the discharge lamp. Before starting, when the voltage applied to both ends of the discharge lamp is lower than the first reference voltage sufficient for preheating the discharge lamp, the output suppression time of the first power supply circuit after the AC power is turned on is extended.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.
It will be explained with reference to FIG. This discharge lamp lighting device is shown in FIG.
As shown, the AC power supply AC is converted into a pulsating DC voltage.
A flow means DB is provided, and the pulse supplied from this rectification means DB
First power supply circuit DN for stepping up or stepping down a flowing DC voltage₁
And the first power supply circuit DN₁Control to control
Circuit SE_FiveThe first power supply circuit DN₁To the output of
Smoothing means C consisting of a capacitor₀The first power supply
Road DN₁Input smoothed DC voltage supplied from
Second power supply circuit DN for generating high frequency output as₂Set up
This second power supply circuit DN₂Second control time to control the
Road SE₆And a second power supply circuit DN₂Power supply from
Discharge lamp DL with filament such as fluorescent lamp
₁Lamp lighting circuit TN for lighting₁And set this
Pump lighting circuit TN ₁Discharge lamp DL₁Between both electrodes of
Detection circuit KN for detecting voltage₁Is provided, and this detection circuit K
N₁The voltage detected by the discharge lamp DL₁To preheat
Sufficient first reference voltage V₁First to determine lower
Judgment circuit HN₃Is provided with a detection circuit KN₁Detected by
Voltage is the first reference voltage V₁Higher discharge lamp D
L₁The second reference voltage V that can stably light up₂Higher
Second judgment time HN for judging _FourIs provided. That
The first determination circuit HN₃Control in response to the output of
Circuit SE_FiveDischarge lamp DL₁Preheated well
As shown in FIG.₁Control the output of the second
Judgment circuit HN_FourThe second control circuit SE in response to the output of
₆Discharge lamp DL₁To reduce the lighting power to
Sea urchin second power supply circuit DN₂Control the output of.

In this case, the first power supply circuit DN₁Boost type
Second power supply circuit DN₂Inver
Circuit for a predetermined time after the AC power supply AC is turned on.
Power supply circuit DN₁From the rectification means DB as a non-operating state
The supplied low-voltage pulsating DC voltage is smoothed by the smoothing means C.₀Through the
2 power supply circuit DN₂Supply to the second power supply circuit DN₂of
Output voltage DL discharge lamp₁Lower than the starting voltage of
Maintenance discharge lamp DL₁The pre-heating of the
After the lapse of time, the first power supply circuit DN₁As the operating state
First power circuit DN₁High voltage DC voltage output from
Second power supply circuit DN₂Supply to the second power supply circuit DN₂
The output voltage of the discharge lamp DL ₁Start, turn on
The first determination circuit HN₃The output of
Answer the first control circuit SE_FiveAC power supply is turned on by
The first power circuit DN later₁To extend the dead time of
I have to.

In the discharge lamp lighting device having the above-described structure, when the voltage applied to both ends of the discharge lamp DL ₁ before starting is lower than the first reference voltage V ₁ sufficient for preheating the discharge lamp DL ₁ , the first The control circuit SE ₅ of the first power supply circuit D ensures that the discharge lamp DL ₁ is sufficiently preheated.
The output of N ₁ is controlled. Further, after the lighting, when the voltage applied to both ends of the discharge lamp DL ₁ is higher than the discharge lamp DL ₁ the reference voltage V ₂ second stable possible lighting,
The output of the second power supply circuit DN ₂ is controlled by the second control circuit SE ₆ so that the lighting power to the discharge lamp DL ₁ is suppressed.

[0020] More specifically, in this discharge lamp lighting device includes an AC power supply AC of a predetermined time after turned on, the second output voltage of the power supply circuit DN ₂ first power circuit DN ₁ as inoperative a voltage lower than the starting voltage of the discharge lamp DL ₁ keep performing the preheating of the discharge lamp DL _1. After the elapse of a predetermined time, the first power supply circuit DN ₁ is operated and the high-voltage DC voltage output from the first power supply circuit DN ₁ is supplied to the second power supply circuit DN ₂ to supply the second power supply circuit. The output voltage of DN ₂ is increased to start and light the discharge lamp DL ₁ . The voltage applied to both ends of the discharge lamp DL ₁ before starting is the first reference voltage V sufficient for preheating the discharge lamp DL _1.
When less than _1, to extend the AC power source AC after the turned first of dead time of the power supply circuit DN _1.

As described above, the discharge lamp point of this embodiment
In the lighting device, the difference from the conventional example is that the detection circuit K
N₁The voltage V detected by_XBut one point in Figure 2
As indicated by the chain line, the second reference voltage V₂Is exceeded,
2 decision circuit HN_FourIt is judged by the second control time
Road SE₆At the second power supply circuit DN₂, So-called INVA
The output of the data circuit is suppressed, and in FIG.
As indicated by the line, the first reference voltage V₁When it goes down,
1 decision circuit HN₃It is judged by the first control time
Road SE_FiveAt the first power supply circuit DN₁Change the behavior of
That is the point. That is, the discharge lamp DL₁In case of abnormalities
Mamoru is the second power supply circuit DN₂In the inverter circuit that is
Discharge lamp DL₁When the ambient temperature is low, the characteristics
Discharge lamp DL due to variations in₁Is difficult to light
If not, the first power supply circuit DN ₁Is a chopper circuit
Change the control operation of and take measures against it.
And are characterized.

FIG. 3 shows a concrete example of the discharge lamp lighting device shown in FIG.
3 shows a typical circuit configuration, and FIG. 4 shows the voltage of each part in FIG.
In FIG. 3, the first power supply circuit DN₁Is a chalk carp
Le L ₁And switching element Q₁And diode D₁, D
₉, Resistance R₁~ R_FourA step-up chopper circuit is configured with
Smoothing means C at its output end.₀The action of V_DCof
A smoothed DC voltage appears.

The control of the first power supply circuit DN ₁ is performed by the first control circuit SE ₅ . That is, the switching control integrated circuit IC ₁ controls ON / OFF of the switching element (MOSFET) Q ₁ via the resistor R ₁₁ . Operation of the switching control integrated circuit IC ₁ 'detects a source current of the switching element Q ₁ at resistor R _2, and determines the timing of the on or off switching elements Q _1, when the resistor R ₁₂ and capacitor C ₉ The ON / OFF section is determined by a feedback circuit composed of a constant circuit and resistors R ₃ , R ₄ , R ₁₃ and a capacitor C ₁₀ .

Further, a switching control integrated circuit IC ₁
The capacitor C ₇ is charged with a charging current determined by the resistor R ₁ , and the charging voltage is the starting voltage (here, V ₀₎ of the switching control integrated circuit IC ₁ .
When (a) is reached, the switching control integrated circuit IC ₁ starts operating. Once the operation is started,
The charging voltage V _CC of the capacitor C ₇ is supplied through the diode D ₉ by the excitation voltage of the secondary winding n ₂ of the choke coil L ₁ .

That is, during the time until the capacitor C ₇ is charged and the charged voltage reaches the voltage V ₀ , the output voltage V _DC of the first power supply circuit DN ₁ simply rectifies and smoothes the voltage of the AC power supply AC. Is a low voltage, and when the switching control integrated circuit IC ₁ starts to operate, the voltage V _DC is set to a predetermined boosted voltage (see FIGS. 4A and 4B). This operation is the so-called discharge lamp DL described above.
_It is a pre-heating operation to preheat filament ₁ .

Next, the second power supply circuit DN₂The description of
U This circuit is a switching element Q ₂, Q₃(here
A bipolar transistor) series inverter,
Switching element Q₂, Q₃In reverse parallel for reverse current
Iodo D₂, D₃Is connected, and the resonance circuit is
Coil L₂Primary winding n₁And lamp lighting circuit TN
₁Trance of₁Secondary winding n₂Connected in parallel to
Indexer C_FiveIt is a series resonance with. C₃Is the coupling
It is a capacitor. Switching element Q₂, Q ₃Driving
Is the switching element Q₂Is the choke coil L₂Return of
Winding n₂Resistance R due to the voltage induced in₈Control through
Controlled self-exciting operation, switching element Q ₃Is the second control
Circuit SE₆Integrated circuit IC for switching control₂By
This is a separately-excited operation controlled by. The operation is resistance R₆，
R₇By the diode D₃Is detected and the switch
Holding element Q₃Determine when to turn on
Time is resistance R_{twenty one}And capacitor C₁₁Determined by the time constant of
To be done.

This second control circuit SE₆Is the power of
Cucoil L₂Winding n wound around₃Powered by
Diode D_Five, Resistance R₉, Capacitor C₆By electricity
Pressure V _C0It constitutes the control power supply of. This control power supply
2 power supply circuit DN₂Inverter circuit switch that is
Element Q₃Is resistance R_Five, Capacitor C₂, Switching
Element Q_FourImmediately after starting by the starting circuit consisting of
stand up. That is, when the AC power supply AC is turned on,
2 power supply circuit DN₂The inverter circuit is a starter circuit
(R_Five, C₂, Q_Four) Starts operation immediately
Of.

Lighting circuit TN₁Is a transformer T₁And con
Densa C_Five, Trance again₁Detection winding n provided in
_FiveDetection circuit KN that detects the voltage of₁Composed by
There is. Detection circuit KN₁Is the diode D₆, Resistance R_Ten，
Capacitor C_Four, Resistance R₁₅Consists of. This transformer T₁
Of the output voltage (lamp voltage) of the first and second
Power supply circuit DN₁, DN₂The first and second control circuits S
E_Five, SE₆It is to control with. Its detection
The voltage is the first determination circuit HN₃And the second determination circuit HN_FourWhen
Is judged by no load or end of life, etc.
The abnormal voltage is generated, the second determination circuit HN_FourResistance R
₁₈, R₁₉Second reference voltage V determined by ₂More than
And comparator IC₃Output goes high and the switch
Integrated circuit IC for switching control₂Resistor R that determines the ON period of_{twenty one}
Diode D in parallel with₇Through the resistor R₂₀Is added,
Capacitor C₁₁The charging curve of the
Integrated circuit IC₂ON period of output out of
The second power supply circuit DN₂The operation of the inverter circuit
Suppress.

Further, the first judgment circuit HN₃Then at low temperature
When the power is turned on, the discharge lamp DL ₁Join between both ends of
If the voltage is lower than the specified voltage, that is, the discharge lamp
DL ₁The voltage applied across both ends of the resistor R₁₆, R₁₇Determined by
First reference voltage V₁When it goes down, the comparator IC_Four
Output becomes high and the resistance R₁₄Via the first control circuit
SE_FiveTransistor Q_Five(Diode D₈Anti-parallel connection
Continue). This makes the conden
SA C₇In parallel with capacitor C₈Power supply voltage V_CC
Rises slowly. This is shown in a time chart
This is shown in FIG. As shown in FIG. 4 (a), the power source
Voltage V_CCThe rising curve of is from the solid line to the alternate long and short dash line
Integrated circuit IC for switching control
₁Operation start time is time t₁From time t₂I'm late
Of. In other words, lengthen the pre-heating time to ensure sufficient discharge.
Lamp DL₁Pre-heat the filament of the discharge lamp
DL₁Is the one that makes it easier to start and light up. Figure 4
(B) is the corresponding first power supply circuit DN₁Output voltage V_DC
The discharge lamp DL is shown in FIG.₁Joined between both ends of
Voltage V_DL(Lamp voltage) is shown.

According to the discharge lamp lighting device of this embodiment, when the voltage applied to both ends of the discharge lamp DL ₁ before starting is lower than the first reference voltage V ₁ sufficient for preheating the discharge lamp DL ₁ , Discharge lamp D by control circuit SE ₅ of 1
The first power supply circuit DN so that L ₁ is sufficiently preheated.
The output of ₁ is controlled, that is, the first power supply circuit DN ₁ is kept inactive for a predetermined time after the AC power supply AC is turned on,
Of performed preheating of the power supply circuit discharges the output voltage of the DN ₂ lamp DL ₁ starting voltage maintained at a voltage lower than the discharge lamp DL _1, the voltage applied to both ends of the discharge lamp before starting sufficient to preheat the discharge lamp When the voltage is lower than the reference voltage of 1, the non-operation time of the first power supply circuit after the AC power is turned on is extended, and the voltage applied to both ends of the discharge lamp DL ₁ becomes stable in the discharge lamp DL ₁ after lighting. When the voltage is higher than the lightable _second reference voltage V ₂ , the second control circuit SE ₆ controls the output of the second power supply circuit DN ₂ so as to suppress the power for lighting to the discharge lamp DL ₁ . That is, after the elapse of a predetermined time, the first power supply circuit DN ₁ is activated and the high-voltage DC voltage output from the first power supply circuit DN ₁ is supplied to the second power supply circuit DN ₂ to supply the second power supply circuit DN ₂ . increasing the output voltage of the power supply circuit DN ₂ Starting the discharge lamp DL ₁ by, since the lighting, the discharge lamp lighting device having a first power supply circuit DN ₁ the second power supply circuit DN _2, error protection by the end of life and the discharge lamp DL ₁ unloaded etc. simultaneously Toka when the discharge lamp ambient temperature of DL ₁ is low, the discharge lamp measures for starting-improving the discharge lamp due to variations in the discharge of DL _1, the first power supply circuit DN ₁ second power supply circuit DN It is possible to provide a discharge lamp lighting device that is easy in design and has a simplified function, since the function allocation in the discharge lamp lighting device of ₂ is clarified.

A second embodiment of the present invention will be described with reference to FIG. This discharge lamp lighting device, as shown in FIG.
The control power supply for the second control circuit SE ₈ is set to the first power supply circuit DN.
The first difference from the first embodiment is that the choke coil L ₁ of the chopper circuit of ₃ is used. That is, in this circuit, the inverter circuit, which is the second power supply circuit DN ₂ , does not operate unless the chopper circuit operates. In particular,
In the first power supply circuit DN _3, the winding n ₃ of the choke coil L ₁ diode D _21, via a resistor R ₃₁ and capacitor C ₂₂ to the second control circuit SE ₈ supplies the control power supply, a first Control power is supplied from the resistor R ₁ and the diode D ₉ to the control circuit SE ₇ through the capacitor C ₂₁ . The second difference is that, in this circuit, the first control circuit SE ₅ has a timer circuit, the output voltage of the chopper circuit is lowered for a predetermined time after the power is turned on, and the predetermined output voltage ( The discharge lamp DL ₁ is set to a voltage at which it can be started and lit, and the same effect as that of the first embodiment can be achieved by changing the timer setting time.

[0032] That is, the second control circuit a second power supply circuit to the SE ₈ so as to supply the control power from the first power supply circuit DN ₃ in response to operation of the first power supply circuit DN ₃ DN ₂
For a predetermined time after the AC power supply AC is turned on, the output of the _first power supply circuit DN ₁ is limited, and a low-voltage DC voltage is supplied to the second power supply circuit DN ₂ to supply the second power supply circuit. the output voltage of the DN ₂ to perform preheating of the discharge lamp DL ₁ starting voltage maintained at a voltage lower than the discharge lamp DL _1, after a predetermined time second increases the output of the first power supply circuit DN ₁ power circuit DN ₂ start the discharge lamp DL ₁ increases the second output voltage of the power supply circuit DN ₂ supplies a high DC voltage to, and so as to light up. Also,
In response to the output of the first decision circuit HN _3, that is, before the start, when the voltage applied to both ends of the discharge lamp DL ₁ is lower than the discharge lamp DL first reference voltages V ₁ preheated enough of _1, AC power supply A is controlled by the first control circuit SE _7.
The output suppression time of the first power supply circuit DN ₃ after C is turned on is extended.

Although the chopper circuit is used as the first power supply circuit and the inverter circuit is used as the second power supply circuit in the above embodiment, the present invention is not limited to this, and the first and second power supply circuits are used.
The power supply circuit may be configured by a chopper circuit, and both the first and second discharge lamp lighting devices may be configured by inverter circuits.

[0034]

According to the discharge lamp lighting device of the present invention, when the voltage applied to both ends of the discharge lamp is lower than the first reference voltage sufficient for preheating the discharge lamp before starting,
The control circuit controls the output of the first power supply circuit so that the discharge lamp is sufficiently preheated.
When the voltage applied to both ends of the discharge lamp is higher than the second reference voltage with which the discharge lamp can be stably lit, the second control circuit suppresses the lighting power to the discharge lamp. Since the output is controlled, in the discharge lamp lighting device having the first power supply circuit and the second power supply circuit, abnormal protection due to the end of life of the discharge lamp or no load, and at the same time when the ambient temperature of the discharge lamp is low, As a measure for improving the startability of the discharge lamp due to variations in the discharge of the lamp, clarify the sharing of the functions of the discharge lamp lighting device of the first power supply circuit and the second power supply circuit, and increase the output of the inverter circuit. It is possible to perform abnormal protection and improve startability without increasing or decreasing the output of the chopper circuit or stopping it, and it is easy to design, It is possible to provide a Ryakuka been discharge lamp lighting device.

[Brief description of drawings]

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

FIG. 2 is a diagram illustrating a detection voltage and a first value in the discharge lamp lighting device of FIG.
3 is a time chart showing the relationship between the second reference voltage and the second reference voltage.

FIG. 3 is a circuit diagram showing an example of a specific circuit configuration of the discharge lamp lighting device of FIG.

FIG. 4 is a time chart showing the operation of the discharge lamp lighting device of FIG.

FIG. 5 is a circuit diagram showing a configuration of a discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a first conventional example of a discharge lamp lighting device.

FIG. 7 is a block diagram showing a configuration of a second conventional example of the discharge lamp lighting device.

[Explanation of symbols]

AC AC power supply DB Rectification means DN ₁ First power supply circuit C ₀ Smoothing means DN ₂ Second power supply circuit TN ₁ Lamp lighting circuit KN ₁ Detection circuit DL ₁ Discharge lamp SE ₅ First control circuit SE ₆ Second Control circuit HN ₃ First judgment circuit HN ₄ Second judgment circuit

Claims (6)

[Claims] 1. A rectifying means for converting an AC power supply into a pulsating direct current voltage, a first power supply circuit for stepping up or stepping down the pulsating direct current voltage supplied from the rectifying means, and a control for the first power supply circuit. A first control circuit, a smoothing means provided at an output section of the first power supply circuit, and a high-frequency output using the smoothed DC voltage supplied from the first power supply circuit as a power supply input. No. 2 power supply circuit, a second control circuit for controlling this second power supply circuit, a lamp lighting circuit for receiving electric power from the second power supply circuit and lighting a filament-equipped discharge lamp, and this lamp. A detection circuit provided in the lighting circuit for detecting a voltage between both electrodes of the discharge lamp, and determining that the voltage detected by the detection circuit is lower than a first reference voltage sufficient for preheating the discharge lamp First decision to A circuit and a second determination circuit that determines that the voltage detected by the detection circuit is higher than the first reference voltage and is higher than a second reference voltage with which the discharge lamp can be stably lit, In response to the output of the first determination circuit, the output of the first power supply circuit is controlled by the first control circuit so that the discharge lamp is sufficiently preheated, and the second determination circuit A discharge lamp lighting device characterized in that, in response to the output, the second control circuit controls the output of the second power supply circuit so as to suppress the lighting power to the discharge lamp. 2. The first power supply circuit is a step-up type, and the low-voltage pulsating DC voltage supplied from the rectifying means is smoothed by leaving the first power supply circuit inactive for a predetermined time after the AC power is turned on. To the second power circuit via the second power circuit
The output voltage of the power supply circuit is maintained at a voltage lower than the starting voltage of the discharge lamp so that the preheating of the discharge lamp is performed, and after the elapse of the predetermined time, the first power supply circuit is set to the operating state and the first power supply circuit is operated. The high-voltage DC voltage output from the power supply circuit is supplied to the second power supply circuit to increase the output voltage of the second power supply circuit to start and light the discharge lamp, and the first determination is made. The discharge lamp lighting device according to claim 1, wherein the first control circuit is configured to extend a non-operation time of the first power supply circuit after the AC power supply is turned on in response to an output of the circuit. 3. A control circuit power is supplied from the first power supply circuit to the second control circuit so that the second power supply circuit operates in response to the operation of the first power supply circuit. For a predetermined time after the power is turned on, the output of the first power supply circuit is limited, a low-voltage DC voltage is supplied to the second power supply circuit, and the output voltage of the second power supply circuit is set lower than the starting voltage of the discharge lamp. The discharge lamp is kept pre-heated at a low voltage, and after the lapse of the predetermined time, the output of the first power supply circuit is increased to supply a high DC voltage to the second power supply circuit to supply the high voltage. The output voltage of the second power supply circuit is increased to start and light the discharge lamp, and in response to the output of the first determination circuit, the first control circuit causes the first control circuit to turn on the AC power supply. The output suppression time of power supply circuit 1 is extended. The discharge lamp lighting device according to claim 1. 4. The first power supply circuit is a chopper circuit,
The discharge lamp lighting device according to claim 1, wherein the second power supply circuit is an inverter circuit. 5. The discharge lamp lighting device according to claim 1, wherein both the first power supply circuit and the second power supply circuit are chopper circuits. 6. The discharge lamp lighting device according to claim 1, wherein both the first power supply circuit and the second power supply circuit are inverter circuits.