JPH10125482A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device of a small size and a low cost but capable of making stabilized lighting even at the time of restart of a high pressure discharge lamp such as a metal halide lamp. SOLUTION: When a capacitor C2 is charged up to a prescribed value at the starting time of a high pressure discharge lamp LP, a semiconductor switch element W is turned on by means of a trigger element inside of a booster circuit 3. Electric load accumulated inside the capacitor C2 firstly flows in the order of capacitor C2 , primary winding Np of high potential pulse transformer PT, current limiting inductance element L, semiconductor switch element Q and capacitor C2 so as to generate a high potential pulse in a secondary winding Ns. Next, after the capacitor C2 is charged in the reverse polarity by resonance with the primary winding Np of the high potential pulse transformer PT, discharge is carried out in the order of capacitor C2 , diode D, primary winding Np of high potential pulse transformer PT and capacitor C2 .

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 stably starting a high pressure discharge lamp such as a metal halide lamp and for stably lighting it.

[0002]

2. Description of the Related Art Conventionally, a discharge lamp lighting device for lighting a high-pressure discharge lamp such as a metal halide lamp uses an igniter unit comprising a high-voltage pulse voltage generating circuit as shown in FIG. 7 (see Japanese Patent Application Laid-Open No. 6-151072). and which switch element Q such as a 3-terminal thyristor by a trigger signal from the trigger element Q _T 'by turning on the capacitor C _11, C ₁₂ switching element charges charged in Q for charging'
And discharges in a path including the primary winding Np of the high-voltage pulse transformer PT, and applies a high-voltage pulse voltage generated in the secondary winding Ns of the high-voltage pulse transformer PT to the high-pressure discharge lamp LP,
Breakdown occurred in the tube of the high-pressure discharge lamp LP, and a transition was made to arc discharge.

[0003]

However, in recent years,
Project high-pressure discharge lamps such as metal halide lamps
To be used as a light source for vehicle and headlights for vehicles.
Use high pressure discharge lamp LP for this kind of application
Power on and off in a short time.
After turning off the high-pressure discharge lamp LP once
Relight without pause (with high pressure discharge lamp hot)
It is necessary to surely start in the so-called hot start
There is. However, high-pressure discharge like metal halide lamps
To start the light LP hot,
It is necessary to apply a high voltage pulse voltage (tens of kV)
It is necessary. Here, means for increasing the high-voltage pulse voltage and
The number of turns of the secondary winding Ns of the high-voltage pulse transformer PT
Or increase the primary side charging voltage.
Had been applied. However, the charging capacitor C₁₁, C ₁₂
Used for the switching element Q 'in the discharge path for discharging the
Are generally replaced by thyristors, triacs, etc.
Since it is a semiconductor switch element represented by
Due to an increase in the inrush current immediately after switch-on
Switch Q 'to prevent destruction of the switch element Q'.
(See JP-A-3-1491).

On the other hand, a high-pressure discharge lamp such as a metal halide lamp has a sufficient current energy at the time of restart because the equivalent resistance after breakdown by applying a high-voltage pulse is larger than the equivalent resistance at the time of initial startup. However, there is a problem in that restart cannot be performed because stable arc discharge cannot be performed even if a breakdown occurs if the electric power cannot be supplied. For this reason, in order to use a high-pressure discharge lamp such as a metal halide lamp in the above application, while supplying a high-voltage pulse voltage having a sufficient magnitude and a sufficient current energy immediately after breakdown,
Although it is necessary to suppress the current stress of the semiconductor switching element, it is necessary to increase the number of turns of the secondary winding Ns of the high-voltage pulse transformer PT in order to increase the high-voltage pulse voltage. However, there has been a problem that the igniter section becomes large and the apparatus becomes large. Further, when the number of turns of the secondary winding Ns increases, the storage capacity between the lines increases, and the distributed capacity as viewed from the primary side increases. Therefore, the current rise rate di / dt immediately after the semiconductor switch element is turned on increases. As a result, the semiconductor switch element may be destroyed. As a countermeasure, increase the number of switch elements or use di
Changing to an element (thyristor, triac, or the like) having a large / dt withstand capability has a problem that the igniter section becomes large and the device becomes large.

The present invention has been made in view of the above circumstances, and has as its object to provide a compact and low-cost discharge lamp lighting device capable of stably lighting even when a high-pressure discharge lamp such as a metal halide lamp is restarted. Is to provide.

[0006]

According to a first aspect of the present invention, there is provided a ballast unit having a ballast unit connected to a power supply for controlling power supplied to a discharge lamp, and a charging capacitor. An igniter unit including a high-voltage pulse generating unit that applies a high-voltage pulse to the discharge lamp when the electric lamp is started and a charging circuit unit that receives an output voltage of the ballast unit and stores energy for generating a high-voltage pulse in the charging capacitor; Wherein the high-voltage pulse generator has a high-voltage pulse transformer with a secondary winding connected in series to the discharge lamp, the charging capacitor, the primary winding of the high-voltage pulse transformer, a current-limiting impedance element, A first closed circuit in which a charge of the charging capacitor is discharged through a path of a semiconductor switch element triggered when a voltage of the charging capacitor rises to a predetermined voltage; An electric capacitor, a diode, and a second closed circuit in which the charge of the charging capacitor is discharged through a path of the primary winding, wherein the charging is performed in the first closed circuit. A high-voltage pulse generated in the secondary winding due to discharge of the charge of the discharge capacitor is applied to the discharge lamp to cause breakdown of the discharge lamp, and thereafter the second pulse is not passed through the current limiting impedance element. Since the high-voltage pulse is generated in the secondary winding by discharging the charge of the charging capacitor in the closed circuit, the starting probability at the time of hot start is improved, and sufficient current energy immediately after the breakdown is increased. A high-voltage pulse voltage large enough to cause the discharge lamp to transition from a glow discharge to a stable arc discharge because it can be supplied to the discharge lamp The current energy can be supplied without increasing the size of the semiconductor switching element, as a result, it is possible to realize a discharge lamp lighting device of small size and low cost.

According to a second aspect of the present invention, in the first aspect of the present invention, the ballast section includes a DC converter section for raising and lowering the DC voltage to supply power to the discharge lamp, and an output voltage of the DC converter section. Since it is configured with an inverter unit that converts the voltage into an AC voltage and supplies the AC voltage to the discharge lamp, desired power supply can be easily performed. According to a third aspect of the present invention, in the first or second aspect of the present invention, a saturable inductance element is used as the current-limiting impedance element. Can be suppressed, and destruction of the semiconductor switch element can be prevented without increasing the size of the semiconductor switch element.

[0008] The invention of claim 4 is the first to third aspects of the present invention.
In the invention of the above, since an insulated gate bipolar transistor is used as the semiconductor switch element, the resistance of the current rise rate immediately after the ON is larger than that of the three-terminal thyristor. Therefore, even if the capacitance component of the secondary winding, which has a large effect on the rise time, is increased, the size of the current limiting impedance element does not need to be increased, and the startability can be improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows a circuit configuration diagram of a discharge lamp lighting device of the present embodiment. The discharge lamp lighting device includes a DC power supply E, a high-pressure discharge lamp LP such as a metal halide lamp, a ballast unit 1, and an igniter unit 2.

The ballast unit 1 controls the power supplied to the high-pressure discharge lamp LP, and reduces or boosts the voltage of the DC power supply E to a voltage required for starting and lighting the high-pressure discharge lamp LP. It comprises a unit 4 (for example, a chopper circuit, a forward circuit, and the like) and an inverter unit 5 that converts a DC voltage output from the DC converter unit 4 into an AC voltage and supplies the AC voltage to the high-pressure discharge lamp LP.

The igniter unit 2 is a starting device that generates a high-voltage pulse when starting the high-pressure discharge lamp LP, applies the high-voltage pulse to the high-pressure discharge lamp L, and shifts to arc discharge. Capacitor C for charging the energy for generating the high-voltage pulse by boosting the output voltage of
_And a high-frequency bypass capacitor C connected in parallel to the output terminal of the inverter unit 5 to prevent application of a high-voltage pulse to the inverter unit 5.
₁ , a high-voltage pulse transformer PT, a saturable current-limiting inductance element L connected to one end of the primary winding Np of the high-voltage pulse transformer PT for suppressing an inrush current to a semiconductor switch element described later, A semiconductor switch element Q such as a three-terminal thyristor connected in series to the inductance element L;
And a diode D connected in parallel to a series circuit of the semiconductor switching element Q and the semiconductor switching element Q. Here, the semiconductor switch element Q is turned on by a trigger signal (gate signal) from the booster circuit 3 when the voltage V _C2 across the capacitor C ₂ reaches a predetermined value. As the semiconductor switching element Q, an insulated gate bipolar transistor (Insulated-Gate Bip) having a control terminal instead of a three-terminal thyristor is used.
olar Transistor: IGBT), MOS control thyristor (MO
S Controlled Thyristor: MCT), MGT (MOS-Asis)
A power semiconductor switching element such as a ted Gate-triggered Thyristor) may be used.

Note that the DC power supply E may be obtained by rectifying and smoothing a commercial power supply. In the case of lighting with a commercial power supply, a high-pressure discharge lamp LP is connected to the commercial power supply via a copper-iron type ballast (a so-called copper ballast).
The igniter unit 2 may be connected to P. Hereinafter, the operation of the present embodiment will be described.

First, when starting the high pressure discharge lamp LP,
When the DC power source E is turned on, the voltage voltage boosted via a DC converter 4 and the inverter section 5 to the DC power source E is applied to both ends of the capacitor C _1. Here, the voltage V _C1 across the capacitor C ₁ is equal to the no-load secondary voltage V _{C1 (0)} required to start the high-pressure discharge lamp LP (steady lighting to supply sufficient energy to shift to arc discharge _). (The voltage higher than the voltage at the time). When the voltage across the capacitor C ₁ is boosted up to a no-load secondary voltage V _{C1 (0),} the no-load secondary voltage V _{C1 (0)} is a high pressure discharge through the secondary winding Ns of the high-voltage pulse transformer PT The voltage is applied to both ends of the lamp LP, and at the same time, the capacitor C ₂ is charged via the booster circuit 3. Here, when the high-pressure discharge lamp LP is a metal halide lamp of about 35 W to 250 W, it is desirable that the no-load secondary voltage V _{C1 (0) be} about 280 V to 380 V.

When the capacitor C ₂ is charged to a predetermined value, the semiconductor switch element Q is turned on by a trigger element in the booster circuit 3. That is, a gate signal is given from the trigger element to the gate of the thyristor which is the semiconductor switching element Q, and the semiconductor switching element Q is turned on. Then
Charges accumulated in the capacitor C ₂ is first flows through a path of the capacitor C ₂ → primary winding Np → limit of the high-voltage pulse transformer PT diverted inductance element L → the semiconductor switching element Q → capacitor C _2. At this time, a high-voltage pulse is generated in the secondary winding Ns of the high-voltage pulse transformer PT, and this high-voltage pulse is superimposed on the output voltage of the inverter unit 5 and connected in series to the secondary winding Ns of the high-voltage pulse transformer PT. Is applied to both ends of the high-pressure discharge lamp LP. High pressure discharge lamp LP
Breaks down by the application of this high voltage pulse and starts discharging.

Next, after the capacitor C ₂ is charged to the opposite polarity by resonance with the primary winding Np of the high-voltage pulse transformer PT, the capacitor C ₂ → diode D → primary winding Np of the high-voltage pulse transformer PT → capacitor C Discharge is performed in path ₂ . By the way, in the present discharge lamp lighting device, the diode D is connected in parallel to the series circuit of the current limiting inductance element and the semiconductor switch element as described above.
As the diode D, a diode having a high current rise rate di / dt is used, and there is no need to connect a current limiting element. Therefore, in the present discharge lamp lighting device, since the diode D is connected, after the breakdown, a current is supplied to the primary winding Np of the high-voltage pulse transformer PT via the diode D without passing through the current-limiting inductance element L. Since the current can flow, sufficient current energy can be supplied immediately after the breakdown. Further, the peak value of the high voltage pulse generated in the secondary winding Ns by the current flowing through the primary winding Np of the high voltage pulse transformer PT via the diode D can be increased.

The high-voltage pulse voltage Vp generated in the secondary winding Ns of the high-voltage pulse transformer P is shown in FIG. 2A, the current IQ flowing in the semiconductor switching element _Q is shown in FIG. _ID has a waveform (actually measured waveform) as shown in FIG. Here, in the present embodiment, since the diode D is connected, FIG.
As shown in (a), the secondary winding N of the pulse transformer PT
Assuming that the peak value of the high-voltage pulse generated in the first half cycle is V _LP1 and the peak value of the second half cycle is V _LP2 , V
_LP1 ≦ V _LP2 can be _satisfied . For this reason, in the conventional example, the magnitude of the pulse after the first half cycle is attenuated, but in the present discharge lamp lighting device, the breakdown probability of the high pressure discharge lamp LP is increased by setting V _LP1 ≦ V _LP2. Become. Moreover, since there is no need to connect a current limiting element in the path of current I _D, the peak value of the current I _D also made large, the igniter portion after the high-pressure discharge lamp LP is broken down near the peak value of the first half cycle 2, since the transition from glow discharge to arc discharge immediately after breakdown can be performed smoothly, and the probability of successful start-up is greatly improved as compared with the conventional example. is there. In the present embodiment, a saturable inductance element L is used as a current limiting impedance element.
Since the impedance of the inductance element L is large, the current rise rate di / dt immediately after the semiconductor switch element Q is turned on can be suppressed, and the semiconductor switch element can be switched without increasing the size of the semiconductor switch element Q. The destruction of the element Q can be prevented.

Thus, in the present discharge lamp lighting device, it is possible to realize the igniter section 2 which can instantaneously restart the high-pressure discharge lamp LP such as a metal halide lamp without increasing the size of the semiconductor switch element Q. Thus, a compact and low-cost discharge lamp lighting device can be realized. (Embodiment 2) FIG. 3 shows a circuit configuration diagram of the igniter section 2 of the discharge lamp lighting device of the present embodiment. Since other circuit configurations are the same as those of the first embodiment, illustration and description are omitted.

The igniter 2 comprises a booster 21, a trigger 22, and a discharger 23. This discharge lamp lighting device, the discharge unit 23, in order to increase the voltage applied to the primary winding Np of the high-voltage pulse transformer PT, a triggerable semiconductor switching element Q _6, such as 3-terminal thyristor, for example the series circuit of the voltage response type switching element Q ₇ as SIDAC the inductance element L ₃ saturable type as current limiting impedance elements are connected in series. In the present embodiment, by connecting the switching element Q _7, it is to increase the charging voltage of the capacitor C _3.

The booster 21 is composed of a flyback converter, and off the switching element Q ₉ which is connected between the primary winding and the inverter section of the flyback transformer T 5 (see FIG. 1) at a predetermined cycle and has, switching element to accumulate energy through the primary winding in the flyback transformer T during on of Q _9, of the flyback transformer T when the off switch element Q ₉ secondary winding and the diode D ₂
Energy through the release into the capacitor C _3.

The trigger portion 22 is charged capacitor C _3, the trigger element Q ₈ When the voltage across V _C3 of the capacitor C ₃ has reached the predetermined value is turned on. Then, in the discharge unit 23,
Since the semiconductor switching element Q ₆ is turned on, and break down voltage across the switching element Q ₇ rises sharply, also on switch element Q _7. By the way, in this discharge lamp lighting device, a high pressure discharge lamp LP such as a metal halide lamp is used.
When no load is applied (non-lighting state), the polarity of the DC bias voltage V _C2 applied to the high-pressure discharge lamp LP is opposite to the polarity of the peak value of the first cycle of the high-voltage pulse voltage.
When the direction of the DC bias matches the direction of the current _ID flowing through the diode D, it is easy to make the pushing current after the breakdown near the peak value sufficiently large.

In the present embodiment, the booster 21 is constituted by a flyback converter, but may be a separately excited type or a self-excited type (RCC). (Embodiment 3) FIG. 4 shows a circuit configuration diagram of a discharge lamp lighting device of the present embodiment. This discharge lamp lighting device includes a DC power supply E,
DC converter unit 4, inverter unit 5, igniter unit 2, and high-pressure discharge lamp LP such as a metal halide lamp
When, and a control unit 10 that drives and controls the switching element Q ₂ to Q ₅ of the switch element Q ₁ and the inverter section 5 of the DC converter 4. Incidentally, d ₂ to d ₄ is the parasitic diode of the switching element Q ₂ to Q _5.

The DC converter section 4 connects the switching element Q ₁ to the DC power supply E via the primary winding N ₁ of the flyback transformer T, and connects the secondary winding N of the flyback transformer T
₂ is connected with a capacitor C ₁ through a diode D ₁ ,
The connection point of the capacitor C ₁ and the secondary winding N ₂ is connected to the negative electrode side of the DC power source E through the resistor R ₁ for detecting the output current. The series circuit of the capacitor C ₁ and resistor R _1, and connected to the resistor R ₂ the resistance R ₃ Metropolitan voltage dividing circuit composed of,
The output voltage of the DC converter unit 4 is input to the control unit 10 by the voltage dividing circuit. Here, the DC converter 4, since the DC power source E is about 12V voltage V _E of the DC power source E when a battery for a motor vehicle, the switching element Q ₁ high frequency (e.g., several tens of kHz
By turning on and off at a frequency of about 300 kHz, the voltage is raised to a voltage (for example, 300 V, 120 V) necessary for starting and lighting the high-pressure discharge lamp LP.

[0023] In this described embodiment, the DC converter unit 4 in a so-called flyback converter, in accordance with the value of the voltage V _E of the DC power source E, the step-up chopper circuit,
A forward converter, a push-pull converter, or the like may be used. The inverter unit 5 is formed of a so-called full-bridge type inverter, and includes four switch elements Q _{2 to} Q _2.
5 is connected to the high-pressure discharge lamp LP via the igniter unit 2 by a bridge connection. The inverter unit 5 includes a switch element Q
_2, Q ₅ and the switching element Q _3, Q ₄ is off is on, the switch element Q _2, Q ₅ is the switch element Q ₃ off, Q ₄ is turned on and a low alternating frequency (e.g. ,
This is repeated at several tens Hz to several hundred Hz), and outputs a low-frequency substantially rectangular wave voltage.

The igniter unit 2 is a switch of the inverter unit 5.
Switch Q_TwoAnd switch element Q_ThreeConnection point and switch
H element Q_FourAnd switch element Q_FiveBetween the connection point
Inductor L for noise filter₁, L_TwoConnected via
Bypass capacitor C_TwoConnected in parallel to
Specifically, the capacitor C_TwoOccur at both ends of
For example, a diode D with a positive half-wave of the alternating voltage_Two, Resistance R_Five
Through the capacitor C _ThreeCharge the condensate with a negative half-wave
Sa C_FourTo diode D_Three, Resistance R₆Charge via both
Capacitor C_Three, C_FourDouble voltage charging circuit that adds the voltage of
And both capacitors C_Three, C_FourFrom IGBT to series circuit
Semiconductor switch element Q₆And current limiting inductance
Element L_ThreeTo the primary winding Np, and the secondary winding Ns
To the condenser C via the high-pressure discharge lamp LP_TwoConnect to both ends of
High-voltage pulse transformer PT and both capacitors C_Three, C
_FourR connected in parallel to the series circuit of₇And capacitors
C _FourAnd a resistor R₇And capacitor C_FourContact with
Connection point and semiconductor switch element Q₆Connected between the gate
Trigger element Q such as SBS₇And semiconductors
Switch element Q₆R connected between the gate and source of the
₈And the current limiting inductance element L_ThreeAnd semiconductor switches
H element Q₆Regenerative diode connected in parallel to the series circuit of
Code D_FourIt is composed of Here, the igniter unit 2
Is the trigger element Q₇Semiconductor switch element when
Q₆Turns on and the capacitor C_Three, C_FourThe charge of the high-pressure pal
Discharge through the primary winding Np of the
Generates a high-voltage pulse in the secondary winding Ns of the pulse transformer PT
It is supposed to.

The control unit 10 includes a voltage proportional to the output voltage of the DC converter 4 detected by the voltage dividing circuit and a voltage across the resistor R ₁ generated in proportion to the output current flowing through the resistor R ₁ . controlling the switching frequency or the on-duty turning on and off the switching element Q ₁ on the basis of and. The control unit 10 is also connected to the gates of the switching element Q ₂ to Q ₅ of the inverter section 5, and controls on and off of switching element Q ₂ to Q ₅ as described above.

The operation of the discharge lamp lighting device will be briefly described below.
I will tell. When the lamp is not loaded (in the non-lighting state), the invar
The output voltage of the high-pressure discharge lamp L
As shown in the left part of FIG.
Square wave voltage (V_LP) Is applied. At this time, Igna
Capacitor C of iter part 2 _Three, C_FourOf the double voltage charging circuit
Charged as a capacitor. That is, the capacitor C
_TwoVoltage V_C2Is the direction of the arrow in the figure
Is the capacitor C _Two→ Diode D_Two→ resistance R_Five→ Con
Densa C_Three→ resistance R_Four→ Capacitor C_TwoCharging on the route
The capacitor C_TwoVoltage V_C2Polarity in the figure
If the direction is opposite to the arrow, the capacitor C_Two→ resistance R_Four→
Capacitor C_Four→ resistance R₆→ Diode D_Three→ Conden
Sa C_TwoThe charging is performed through the route.

Capacitor C_Three, C_FourIs the predetermined value
(For example, 100 V), the trigger element Q
₇Is turned on, and as a result, the semiconductor switching element Q₆No
Voltage is supplied to the semiconductor switching element Q₆Also on
I do. At this time, first, the capacitor C_Three→ High pressure pulse
Primary winding Np of lance PT → inductance element for current limiting
L_Three→ Semiconductor switch element Q₆→ Capacitor C_FourPath
Causes a high-current pulse A as shown in FIG.
(Peak value V_LP1) Is applied to the high pressure discharge lamp LP. What
Contact, semiconductor switch element Q₆Semiconductor switch immediately after
H element Q₆The inrush current flowing between the main terminals of the
Ductance element L _ThreeSemiconductor semiconductor
Switch element Q₆To large elements with large di / dt resistance
Semiconductor switch element Q without change₆Prevent the destruction of
Can be

Next, the igniter unit 2, through current limiting inductance element L ₃ directly to the primary winding Np of the high-voltage pulse transformer PT without passing through the path, that is, the capacitor C
₄ → diode D ₄ → primary winding Np of high voltage pulse transformer PT → capacitor C ₃ → current flows through the path of capacitor C ₄ , so that the same effects as in the first and second embodiments can be obtained.

Further, in the present embodiment, as the semiconductor switching element Q _6, immediately after the on-compared to 3-terminal thyristor d
Since an IGBT having a large i / dt resistance is used, even if the capacitance component of the secondary winding Ns, which has a large effect on the rise time of the high-voltage pulse, is increased in order to moderate the rise of the high-voltage pulse, the current-limiting inductance can be increased. the value does not need to increase the element L _3, it is to improve the startability.

Accordingly, the high-pressure discharge lamp LP is discharged by the first high-pressure pulse A, and thereafter shifts to arc discharge and is stably lit. Therefore, the lamp current I _L flowing through the high-pressure discharge lamp LP
As shown in FIG. 5B, a substantially constant current flows after a pulse-like change. (Embodiment 4) The basic configuration of the present embodiment is substantially the same as that of Embodiment 3, and the feature thereof lies in the circuit configuration of the igniter unit 2. Therefore, only the igniter unit 2 will be described. The description of the operation is omitted.

By the way, in the discharge lamp lighting device of the third embodiment,
Indicates the function of the discharge start switch in the igniter unit 2.
Semiconductor switching element Q₆Use IGBT as
The semiconductor switching element Q₆Flow between the main terminals
The peak value of the pulse current is determined based on the gate voltage.
You. The igniter unit 2 in the present embodiment is shown in FIG.
So, the resistance R₁₂And resistance R ₁₃And a resistor R₁₃
C connected to both ends of₆Bird consisting of
The timer circuit for the battery_FiveAnd trigger element Q₉When
Between the trigger timer circuit
Densa C₆When the voltage across the
Child Q₉Turns on. Trigger element Q₉Then switch element
Child Q₈Turns on, and then the switching element Q₇Is on
And capacitor C_FiveDrive voltage charged to IGB
Semiconductor switching element Q made of T₆Applied to the gate
And the semiconductor switching element Q₆Turns on immediately.

[0032] Here, the voltage across V _C5 of the capacitor C _5, when the voltage across the capacitor C ₆ and V _C6, V _C5
> For a V _C6, in the embodiment 3 can increase the gate voltage of the semiconductor switching element Q ₆ compared to (see FIG. 4), since the upper limit of the peak current of the semiconductor switching element Q _6, can be increased, Current limiting inductance element L ₃
And the high-voltage pulse transformer PT can be reduced in size,
The device can be reduced in size.

[0033]

According to the first aspect of the present invention, there is provided a ballast unit which is connected to a power supply and controls power supplied to a discharge lamp, and has a charging capacitor and applies a high-voltage pulse to the discharge lamp when the discharge lamp is started. And an igniter unit including a charging circuit unit that receives the output voltage of the ballast unit and stores energy for generating a high-voltage pulse in the charging capacitor. A high-voltage pulse transformer with a secondary winding connected in series to the light,
The charge of the charging capacitor is discharged through a path of the charging capacitor, a primary winding of the high-voltage pulse transformer, a current limiting impedance element, and a semiconductor switch element triggered when the voltage of the charging capacitor rises to a predetermined voltage. A first closed circuit, and a second closed circuit in which the charge of the charging capacitor is discharged through a path of the charging capacitor, the diode, and the primary winding.
A high voltage pulse generated in the secondary winding is applied to the discharge lamp by discharging the charge of the charging capacitor in a closed circuit, causing breakdown of the discharge lamp,
Thereafter, a high-voltage pulse is generated in the secondary winding by discharging the charge of the charging capacitor in the second closed circuit without passing through the current-limiting impedance element. As a result, it becomes possible to supply sufficient current energy to the discharge lamp immediately after the breakdown, so that a high-voltage pulse voltage and a current large enough to cause the discharge lamp to transition from a glow discharge to a stable arc discharge. Energy can be supplied without increasing the size of the semiconductor switch element, and as a result, there is an effect that a compact and low-cost discharge lamp lighting device can be realized.

According to a second aspect of the present invention, in the first aspect of the present invention, the ballast section includes a DC converter section for raising and lowering a DC voltage to supply power to a discharge lamp, and an output voltage of the DC converter section. Since it is configured with the inverter unit that converts the voltage into an AC voltage and supplies the AC voltage to the discharge lamp, there is an effect that desired power supply can be easily performed. The invention according to claim 3 is the invention according to claim 1 or claim 2,
Since a saturable inductance element is used as the current limiting impedance element, the impedance of the inductance element is large, so that the current rise rate immediately after the semiconductor switch element is turned on can be suppressed, and the semiconductor switch element is enlarged. There is an effect that the destruction of the semiconductor switch element can be prevented without performing.

The invention according to claim 4 is the invention according to claims 1 to 3.
In the invention of the above, since an insulated gate bipolar transistor is used as the semiconductor switch element, the resistance of the current rise rate immediately after the ON is larger than that of the three-terminal thyristor. Even if the capacitance component of the secondary winding, which has a large effect on the rise time of the current, is increased, there is no need to increase the current-limiting impedance element, and there is an effect that the startability can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing a first embodiment.

FIG. 2 is an operation explanatory view of the above.

FIG. 3 is a circuit configuration diagram of a main part according to a second embodiment.

FIG. 4 is a circuit configuration diagram showing a third embodiment.

FIG. 5 is an operation explanatory view of the above.

FIG. 6 is a circuit configuration diagram of a main part according to a fourth embodiment.

FIG. 7 is a circuit configuration diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ballast part 2 Igniter part 3 Booster circuit 4 DC converter part 5 Inverter part E DC power supply Q Semiconductor switch element LP High pressure discharge lamp PT High voltage pulse transformer D diode L Current limiting inductance element

Claims (4)

[Claims] A ballast connected to a power supply for controlling power supplied to the discharge lamp; a high-voltage pulse generator having a charging capacitor for applying a high-voltage pulse to the discharge lamp when the discharge lamp is started; An igniter unit including a charging circuit unit to which the output voltage of the ballast unit is input and stores energy for generating a high-voltage pulse in the charging capacitor, wherein the high-voltage pulse generating unit is configured to perform secondary winding in series with the discharge lamp. A high-voltage pulse transformer to which a line is connected, the charging capacitor, a primary winding of the high-voltage pulse transformer, a current-limiting impedance element, and a semiconductor switch element that is triggered when the voltage of the charging capacitor rises to a predetermined voltage. A first closed circuit in which the charge of the charging capacitor is discharged through a path; The second when the charge of the capacitor is discharged
And a closed circuit for the discharge lamp. 2. The ballast unit comprises: a DC converter unit for increasing or decreasing a DC input voltage; and an inverter unit for converting an output DC voltage of the DC converter unit into an AC voltage and supplying the AC voltage to a discharge lamp. 2. The method according to claim 1, wherein
The discharge lamp lighting device as described in the above. 3. The discharge lamp lighting device according to claim 1, wherein a saturable inductance element is used as the current limiting impedance element. 4. The discharge lamp lighting device according to claim 1, wherein an insulated gate bipolar transistor is used as the semiconductor switch element.