JPH04253182A - discharge lamp lighting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 that is capable of lighting a discharge lamp and other lamps such as incandescent lamps with one device.

0002

2. Description of the Related Art Hitherto, lighting fixtures using discharge lamps have been widely used. Generally, in order to light a discharge lamp,
A lighting device is required between the power source and the discharge lamp as a stabilizing element to limit the current supplied to the discharge lamp. This lighting device corresponds one-to-one to the combination of power supply and discharge lamp, and depends on the voltage and frequency of the power supply, the wattage and type of discharge lamp (for example, the difference between metal halide, sodium lamp, and mercury lamp). Correspondingly and individually designed. Therefore, if a different discharge lamp is connected to a lighting device designed for a certain combination of power source and discharge lamp, it may not light up or
Even if the lamp is turned on, it may not emit proper light, or it may become overloaded, causing problems such as damage to the discharge lamp. In addition, in such a discharge lamp lighting device, even if an incandescent lamp is used instead of a discharge lamp, there are problems such as insufficient light being emitted or overload causing the filament to break.

By the way, discharge lamps also have a limited lifespan. Even when a discharge lamp stops lighting due to the end of its life, there is a desire to use another lamp as an emergency lighting fixture. Also,
It is also conceivable to light up another lamp instead of the discharge lamp to change the emitted light color and change the lighting effect. Most common lamps are standard screw-type Edison base sockets, and both discharge lamps and incandescent lamps have the same shape. In addition, if you configure the discharge lamp socket in the same socket format as the H4 halogen bulb (incandescent lamp) that is popular in automobile headlights, you can use the H4 bulb in the same lamp body with a discharge lamp type headlight. can be attached.

0004

[Problems to be Solved by the Invention] As mentioned above, even if you want to replace another lamp with a discharge lamp that has the same socket standard and can be installed in the same lighting equipment, the lighting device of the discharge lamp is Since the lamp is located between the lamp and the socket, other lamps cannot be used easily.

The present invention has been made in view of the above-mentioned points, and its object is to provide a discharge lamp lighting device for use with other lamps such as incandescent lamps having a socket portion of the same standard as the discharge lamp. The purpose is to enable even a lamp to be lit almost normally.

[0006]

[Means for Solving the Problems] In order to solve the above problems, in the discharge lamp lighting device of the present invention, as shown in FIG. 1, a first lighting means 1 for lighting the discharge lamp,
Second lighting means 2 for lighting lamps other than discharge lamps
a lamp discriminating means 3 for discriminating the type of lamp RL by applying a predetermined low voltage to the lamp RL and detecting the presence or absence of lamp current before performing an operation of lighting the discharge lamp; and the lamp discriminating means 3. switching means Ry1, which lights the discharge lamp using the first lighting means 1 if it is a suitable discharge lamp according to the discrimination result by the judgment result; It is characterized by having Ry2.

[0007]

[Operation] The operation of the present invention will be explained below based on FIG. When the power switch SW is turned on, power is supplied from the power supply V1 to the lamp RL via the first lighting means 1 for lighting the discharge lamp, and the type of the lamp RL is determined by the lamp discrimination means 3. If the type of lamp RL is not compatible with the first lighting means 1, it is switched to the second lighting means 2,
Turn on the lamp RL. Note that by changing a part of the operation of the same lighting circuit according to the determination result of the lamp discriminating means 3, the first lighting means 1 and the second lighting means 2 may be used together. Further, in place of the lamp discriminating means 3, the characteristics of the lighting device may be changed after a certain period of time after the power is turned on so that other lamps can be lit at their rated ratings.

[0008]

Embodiment FIG. 2 is a circuit diagram of a first embodiment of the present invention. The power source V1 is a DC power source consisting of a battery such as DC12V. Circuit A is a boost chopper circuit, and DC
A low power supply voltage of several tens of volts is boosted to a high voltage of several 100 volts (Vdc) required to keep the discharge lamp lit. Circuit B
is a full-bridge square wave inverter circuit, which supplies a low frequency square wave voltage to the discharge lamp.

First, the configuration and operation of circuit A will be explained. DC power supply V1 has power switch SW and relay contact R
The voltage is input to the chopper circuit A via y1, and this voltage is applied to the series circuit of the inductor L1 and the transistor Q3. A smoothing capacitor C1 is connected to both ends of the transistor Q3 via a backflow blocking diode D1.
is connected. When the power is turned on, the control circuit 4
starts operating, and transistor Q3 turns on at high frequency.
/Turned off. When transistor Q3 is turned on, current flows from the power supply to inductor L1, and electromagnetic energy is accumulated. Then, when the transistor Q3 is turned off, a voltage is induced across the inductor L1 due to the electromagnetic energy accumulated in the inductor L1.
1 is charged. The DC voltage Vdc obtained at the smoothing capacitor C1 is fed back to the control circuit 4 and adjusted to an appropriate voltage by controlling the switching frequency and ON duty of the transistor Q3.

Next, the configuration and operation of circuit B will be explained. The DC voltage Vdc charged in the smoothing capacitor C1 is connected to a series circuit of transistors Q4 and Q5, and
It is applied to a series circuit of transistors Q6 and Q7. Each transistor Q4, Q5, Q6, Q7 has
Each diode is connected in antiparallel. Connection point between transistors Q4 and Q5 and transistors Q6 and Q
A series circuit of a capacitor C2 and an inductor L2 is connected between the connection points of the capacitor C2 and the inductor L2. Capacitor C2
A lamp RL is connected to both ends of the lamp via relay contacts Ry2 and Ry3 and a lamp current detection circuit IDT. The inverter control circuit 5 includes transistors Q4,
Switch Q5, Q6, and Q7.

First, in the first period, the transistor Q4
, Q7 are turned on and off in high frequency synchronization, and transistors Q5 and Q6 are turned off. When transistors Q4 and Q7 are turned on, current flows through transistor Q4, capacitor C2, lamp RL, inductor L2, and transistor Q7 due to DC voltage Vdc, and when transistors Q4 and Q7 are turned off, a current flows through the inductor L2 and anti-parallel diode of transistor Q6. , the capacitor C1, the anti-parallel diode of the transistor Q5, the capacitor C2, and the lamp RL. Since the high frequency component of this current is bypassed by the capacitor C2, a direct current flows in one direction through the lamp RL.

Next, in the second period, transistor Q4
, Q7 are turned off, and transistors Q5, Q6 are turned off.
are turned ON/OFF in high frequency synchronization. When transistors Q5 and Q6 are turned on, transistor Q6, inductor L2, and capacitor C are turned on by DC voltage Vdc.
2, lamp RL, and transistor Q5, and when transistors Q5 and Q6 are turned off, inductor L2, capacitor C2, lamp RL, anti-parallel diode of transistor Q4, capacitor C1,
Current flows through the anti-parallel diode of transistor Q7. Since the high frequency component of this current is bypassed by the capacitor C2, a direct current flows through the lamp RL in the opposite direction to the above. Therefore, the lamp RL is supplied with a low frequency rectangular wave current whose polarity alternates between the first period and the second period.

The current I flowing through the lamp RL is detected by a lamp current detection circuit IDT. This circuit IDT is
It is configured to detect the presence or absence of a current I flowing through the lamp RL, and output a high level signal if the current I is flowing, and this signal is used as one input of the AND circuit AND. The other input of the logical product circuit AND is
The output signal of the monostable multivibrator MMV is input. The trigger input of this monostable multivibrator MMV is connected to a DC power supply V1 via a power switch SW. The monostable multivibrator MMV outputs a pulse with a constant width when the trigger input rises to a high level. This output signal is also input to the base of a transistor Q1 via a resistor R1, and this transistor Q1 is connected between the base and emitter of a transistor Q3 so as to clamp the output of the control circuit 4.

The TFF is a flip-flop, which is reset when the power is turned on, and its output Q becomes a low level, and when the clock input becomes a high level, the output Q becomes a high level.
This is to maintain it at a high level. The clock input of the flip-flop TFF is connected to the output of the AND circuit AND, and the output Q of the flip-flop TFF is connected to the base of the transistor Q2 via the resistor R2. The series circuit of the transistor Q2 and the relay coil Ry constitutes a closed circuit together with the series circuit of the DC power supply V1 and the power switch SW.

Ry1, Ry2, Ry3 are the contacts of the relay coil Ry, which are a normally closed contact NC and a normally open contact NO.
Each is equipped with When the relay coil Ry is not excited, the relay contacts Ry1, Ry2, Ry
3 is connected to the normally closed contact NC, and the relay coil R
When y is excited, relay contacts Ry1, Ry2, R
y3 is connected to normally open contact NO.

The operation of the circuit shown in FIG. 2 will be explained below. When the power switch SW is turned on, the output of the monostable multivibrator MMV becomes High level and the transistor Q1 is turned on, so that the base and emitter of the switching transistor Q3 of the chopper circuit A are short-circuited. Therefore, chopper circuit A does not operate,
The DC voltage Vdc of the capacitor C1 is the DC voltage V1 of the DC power supply V1.
It is about several tens of volts, which is equivalent to . Also, inverter circuit B
performs low frequency square wave operation.

Here, if the lamp RL is a discharge lamp, the discharge lamp cannot start discharging because the output voltage of the inverter circuit B is low. Therefore, the lamp current I becomes zero, and the output of the lamp current detection circuit IDT becomes Low level. Therefore, the output of the AND circuit AND becomes a Low level, and the output of the flip-flop TFF maintains a Low level. Since transistor Q2 is not turned on, relay coil Ry is not excited, and each relay contact Ry1, Ry
2 and Ry3 remain connected to the normally closed contact NC side.

After the monostable multivibrator MMV generates a pulse for a predetermined time (substantially several tens of microseconds to several seconds), the output becomes Low level. After that, the monostable multivibrator MMV maintains a low level output. Therefore, the output of the AND circuit AND remains at a low level, and the output Q of the flip-flop TFF also remains at a low level.
remains at the level. Therefore, the relay coil Ry is not excited and each relay contact Ry1, Ry2, Ry3
remains connected to the normally closed contact NC side.

When the output of the monostable multivibrator MMV becomes Low level, the transistor Q1 is turned off and the chopper circuit A starts operating. As a result, the voltage Vdc of the capacitor C1 reaches a predetermined high voltage, and a voltage for lighting the discharge lamp is generated at the output terminal of the inverter circuit B, and lighting of the discharge lamp starts. The above operation is shown in FIG.

If the lamp RL is an incandescent lamp, the output of the monostable multivibrator MMV will be Hi after the power is turned on.
During the period when the voltage is at gh level, the chopper circuit B generates a low voltage Vdc, but since the lamp current I flows through the incandescent lamp, the output of the lamp current detection circuit IDT becomes high level, and the output of the AND circuit AND also becomes high. level,
The output Q of flip-flop TFF becomes High level, transistor Q2 turns on, and relay coil R
y is excited, relay contacts Ry1, Ry2, Ry3
All the contacts are switched to the normally closed NO side, the lamp RL and the DC power supply V1 are directly connected, the voltage V of the incandescent lamp increases, and normal lighting (= rated lighting) starts. Thereafter, even if the output of the monostable multivibrator MMV becomes Low level, the output Q of the flip-flop TFF cannot be reversed, so this rated lighting state is continued. The above operation is shown in Figure 4.
Shown below.

According to this embodiment, even if the discharge lamp is compatible with this lighting device, it is also an incandescent lamp that has a socket of the same shape and standard as the discharge lamp and can be lit with the DC power source V1. Both can be lit normally at their respective rated outputs. Note that a configuration may also be adopted in which a commercial AC power source is connected instead of the DC power source V1 and a rectifier and smoother is added to the input side of the chopper circuit A.

FIG. 5 is a circuit diagram of a second embodiment of the present invention. AC is a commercial alternating current power supply, and DB1 is a full-wave rectifier. A boost chopper circuit A, a buck chopper circuit B1, and a low frequency full bridge circuit B2 are connected to the output side of the full-wave rectifier DB1. First, circuit A is a step-up chopper circuit similar to the first embodiment, and has the function of generating voltage Vdc for maintaining lighting of the discharge lamp and reducing input current distortion. Next, the circuit B1 is a step-down chopper circuit, and the control circuit 6 turns on/off the transistor Q8 at high frequency.
It is turned off, and the smoothing capacitor C3 is charged with a voltage V lower than the voltage Vdc via the inductor L3. The energy stored in inductor L3 circulates through diode D2. By controlling the switching frequency and ON duty of the transistor Q8 by the control circuit 6, the voltage V of the capacitor C3 is controlled, and the power supplied to the lamp is controlled. Furthermore, circuit B2
is a low frequency full bridge circuit. Transistor Q4
, Q7 are ON, transistors Q6 and Q5 are OFF
The first state is F, and the transistors Q4 and Q7 are O.
The second state in which the FF and transistors Q6 and Q5 are turned on is switched at a low frequency (several 100 Hz). These circuits B1 and B2 provide a low frequency rectangular wave voltage to the lamp RL.

Next, the configuration for controlling these circuits will be explained. EA1 is an error amplifier for detecting the lamp voltage V, and E1 is a reference voltage for determining the target lamp voltage. EA2 is an error amplifier for detecting the lamp current I, and E2 is a reference voltage for determining the target lamp current. Error amplifier EA2 is a low resistor for detecting lamp current I as a voltage signal. The output of error amplifier EA1 is connected to resistor R4 and diode D3.
The output of the error amplifier EA2 is input to the PWM oscillator 8 via a resistor R5 and a diode D4. These diodes D3 and D4 constitute a wired OR circuit. The PWM oscillator 8 is connected to a transistor Q8 according to the output of the error amplifier EA1 or EA2 via a wired OR circuit.
ON/OFF control.

Next, the lamp current detection circuit IDT is composed of a comparator CMP and a reference voltage E3, and compares the voltage of the low resistor R3 for detecting the lamp current I with the reference voltage E3 by the comparator CMP. This circuit IDT detects the presence or absence of a current I flowing through the lamp RL, and if the current I is flowing, it outputs a high level signal, and this signal is used as one input of the AND circuit AND. There is. The output signal of the monostable multivibrator MMV is input to the other input of the AND circuit AND. This monostable multivibrator MMV
The trigger input is connected to the control power supply.

Here, the control power source includes a step-down transformer T connected to a commercial AC power source AC via a power switch SW, a full-wave rectifier DB2 that rectifies the step-down output, and a capacitor C4 that smoothes the rectified output. When the power switch SW is turned on, a low DC voltage is obtained at the capacitor C4.

The monostable multivibrator MMV outputs a pulse with a constant width when the trigger input rises to a high level. This output signal is also input to the base of a transistor Q1 via a resistor R1, and this transistor Q1 is connected between the base and emitter of a transistor Q3 in order to clamp the output of the chopper control circuit 4.

[0027] TFF is a flip-flop, which is reset when the power is turned on, and when its output Q goes to Low level, and when the clock input goes to High level, output Q goes to High level.
This is to maintain it at a high level. The clock input of the flip-flop TFF is connected to the output of the AND circuit AND, and the inverting output and non-inverting output of the flip-flop TFF are connected to the bases of transistors Q9 and Q10, respectively. The transistors Q9 and Q10 respectively connect the anode sides of the diodes D3 and D4 to the ground line.

The operation of this embodiment will be explained below. When the power switch SW is turned on, the transformer T generates a control power supply voltage. This triggers the monostable multivibrator MMV and its output Q becomes High.
level, transistor Q1 turns on,
The boost chopper circuit A becomes inoperative. Further, the step-down chopper circuit B1 and the low frequency full bridge circuit B2 operate. At this time, the non-inverted output Q of the flip-flop TFF is reset to Low level, the inverted output to High level, transistor Q9 is turned on, and transistor Q10 is turned off.

Here, if the lamp RL is a discharge lamp, discharge will not start due to insufficient voltage across the lamp. Therefore, the lamp current I is zero, and the lamp current detection circuit I
Since DT is at a low level, the output of the AND circuit AND is at a low level, and the flip-flop TFF is not triggered. When the output Q of the monostable multivibrator MMV becomes a low level after a certain period of time has passed, the output of the AND circuit AND is held at a low level. Therefore, the output of the flip-flop TFF does not change, and the transistor Q9 is turned on and the transistor Q10 is turned off. Therefore, the PWM oscillator 8 includes an error amplifier E.
The output of A2 is input. Furthermore, by turning off the transistor Q1, the boost chopper circuit A starts operating, the discharge lamp lights up, and the lamp current I flows. As a result, the comparator CM of the lamp current detection circuit IDT
The output of P becomes High level, but since the output Q of monostable multivibrator MMV is already Low level, the output of the AND circuit AND maintains Low level. Here, if the reference voltage E2 of the error amplifier EA2 is set to the lamp current value, the discharge lamp will be in a normal lighting state. The above operation is shown in FIG.

If the lamp is an incandescent lamp, the output Q of the monostable multivibrator MMV becomes H immediately after the power is turned on.
The lamp current I begins to flow during a period of high level,
Comparator CMP in lamp current detection circuit IDT
The output of the logical product circuit AND becomes High level, and the output of the AND circuit AND becomes High level. Therefore, the flip-flop TFF is triggered and its non-inverting output Q becomes High.
level, and transistor Q10 is turned on. Therefore, the output of the error amplifier EA2 is not input to the PWM oscillator 8. On the other hand, the inverted output of flip-flop TFF is Lo
Since the level is W, the transistor Q9 is turned off. Therefore, the output of the error amplifier EA1 becomes the input of the PWM oscillator 8. After that, when a certain period of time has passed and the output Q of the monostable multivibrator MMV becomes Low level, the boost chopper circuit A starts operating and the lamp current I
increases. If the reference voltage E1 of the error amplifier EA1 is set to the rated voltage value of the incandescent lamp, the incandescent lamp will be in a normal lighting state. The above operation is shown in FIG.

This second embodiment has the same effect as the first embodiment. In addition, in the first embodiment, the DC power supply V1
Although compensation for fluctuations in the DC power source V1 is limited to when the discharge lamp is lit, in the second embodiment, compensation for fluctuations in the DC power supply V1 is possible not only when the discharge lamp is lit, but also when the incandescent lamp is lit. Therefore, incandescent lamps can be used even if they are not for commercial AC power supply. For example, the incandescent lamp may be 100V, and the commercial power supply AC may be 200V. In the circuit shown in Fig. 5, the input of the error amplifier EA2 is the lamp current I, which is suitable for constant current lighting of a metal halide lamp, but if the input of the error amplifier EA2 is the lamp voltage V, then the constant voltage lighting of a sodium lamp is suitable. It is suitable for In addition, commercial power supply A
C may be a DC power source such as a DC12V battery, and in this case, the diode bridge DB1 can be omitted.

FIG. 8 is a circuit diagram of a third embodiment of the present invention. The configuration is almost the same as the second embodiment. The detection values of lamp voltage V and lamp current I are multiplied by multiplier MLT, and the multiplication result is input to error amplifier EA. Also, the reference value of the error amplifier EA is the reference voltage E1 and the resistor R6.
, R7, R8 and the transistor Q2.

The method for distinguishing between discharge lamps and incandescent lamps is the same as in the second embodiment. For discharge lamps, flip-flop TF
The inverted output of F becomes High level, so transistor Q2 turns on, and the reference value of error amplifier EA becomes V.
x=R7·E1/(R6+R7). If it is an incandescent lamp, the inverted output of the flip-flop TFF is Lo.
Therefore, the transistor Q2 turns off, and the reference value of the error amplifier EA becomes Vx = (R7 + R8
)・E1/(R6 +R7 +R8). Therefore, the reference value Vx of the error amplifier EA is higher for incandescent lamps. In this third embodiment, since the lamp voltage V and the lamp current I are multiplied, the input of the error amplifier EA corresponds to the lamp power. In this embodiment, the lamp is operated with constant lamp power, but since the reference value Vx for incandescent lamps is higher than that for discharge lamps, more power is supplied to incandescent lamps. In the first or second embodiment, for example, if a 35W metal halide lamp is used, a light output of about 2800 lm can be obtained. To obtain the same light output with an incandescent lamp, a halogen lamp of approximately 110 W would be required. In this example, if the lamp power output of the incandescent lamp is set to 110W, a 110W halogen lamp will naturally have the same light output as a 35W metal halide lamp, but even a 55W halogen lamp is forced to operate at 110W, so Equivalent light output. For this reason, although there is a problem of a short lifespan, there is no problem with temporary use for a short period of time until the car headlight arrives at a repair shop, and the headlight can be used without reducing the light output.

FIG. 9 is a circuit diagram of a fourth embodiment of the present invention. V1 is a DC power supply, which is connected to a series circuit of switching elements Q11 and Q12 via a power switch SW. Switching elements Q11 and Q12 are MOSF
ET, each with a built-in anti-parallel diode. An inductor L is connected to both ends of the switching element Q12.
A parallel circuit of a capacitor C6 and a lamp RL is connected via a capacitor C5 and a capacitor C5. A series circuit of resistors R9 and R10 is connected in parallel to both ends of the lamp RL. The detection voltage Vdt obtained across the resistor R10 is amplified by the amplifier circuit 11. The amplifier circuit 11 includes an operational amplifier OP and resistors R11, R12,
R13, R14, R15 and transistors Q13, Q14
and a reference voltage E4. Transistor Q13
, Q14 are OFF for a certain period of time T from when the power switch SW is turned on, as shown in FIG. 10, and are both turned ON after this time T has elapsed. Transistors Q13 and Q14 are OFF
FIG. 11 shows the relationship between the current Ix of the operational amplifier OP and the voltage V across the lamp RL when it is F and when it is ON.

A triangular wave oscillator 10 is connected to the output side of the amplifier circuit 11. This oscillator 10 includes a current mirror circuit made up of transistors Q15 and Q16. Transistor Q1 of this current mirror circuit
The current Ic flowing through the amplifier circuit 1 is the current (Vcc/R16) determined by the control power supply voltage Vcc and the resistor R16.
The current is the sum of the current Ix of 1. The same current as the current Ic flowing through the transistor Q15 is the same as the current Ic flowing through the transistor Q15.
16 and charges capacitor C7. When the voltage of capacitor C7 exceeds reference voltage E5, the output of Schmitt trigger circuit ST becomes High level,
Transistor Q17 is turned on. As a result, capacitor C7 is discharged. Therefore, capacitor C7
A sawtooth wave voltage Vc is generated at both ends of the voltage Vc. This sawtooth wave voltage Vc is compared with the reference voltage E6 of the comparator CP and converted into a rectangular wave voltage of frequency f, and the drive circuit 9
The frequency of the signal is divided by , and input to the control terminals of switching elements Q11 and Q12. As a result, switching elements Q11 and Q12 are alternately turned on and off.

When the power switch SW is turned on, the timer 12 is started. The output of the timer 12 is at a low level when the power is turned on, and becomes a high level after a certain period of time T has elapsed, as shown in FIG. timer 1
The output of timer 12 is input to the control terminals of transistors Q13 and Q14, and when the output of timer 12 becomes High level, transistors Q13 and Q14 are turned on. When the lamp voltage V is low, as shown in FIG. 11, the magnitude of the current Ix of the operational amplifier OP is different depending on whether the transistors Q13 and Q14 are on or off. As a result, the current Ic flowing through the current mirror circuit
Since the magnitude of C7 changes and the charging speed of capacitor C7 changes, the oscillation frequency f of the oscillator 10 changes. Conversely, when the lamp voltage V is high, the output of the operational amplifier OP is saturated, so the oscillation frequency f of the oscillator 10 does not change.

Now, switching elements Q11 and Q12 are alternately turned on and off at the oscillation frequency f of the oscillator 10, thereby supplying high frequency power to the lamp RL. First, when the switching element Q11 is ON and the switching element Q12 is OFF, the DC power supply V1 is connected to the power switch SW, the switching element Q11, and the inductor L.
4, capacitor C5, lamp RL and capacitor C6
Current flows through. Next, switching element Q1
When Q1 is OFF and switching element Q12 is ON, capacitor C5 is used as a power source, and capacitor C5,
Inductor L4, switching element Q12, lamp R
Current flows through L and capacitor C6. Note that capacitor C5 is a coupling capacitor for cutting DC components, and capacitor C6 and inductor L4 constitute an LC series resonant circuit. The feedback current due to resonance is
It flows through anti-parallel diodes of switching elements Q11 and Q12.

[0038] Here, the starting operation will be explained in the case where the lamp RL is a high pressure discharge lamp. Immediately after the power is turned on, the output of the timer 12 becomes Low level, and the transistors Q13 and Q14 are turned off. For this reason, Figure 1
1, when the voltage V across the lamp RL increases, the output of the amplifier circuit 11 decreases, the current Ix increases, and the current Ic also increases, so that the oscillation frequency f of the oscillator 10 increases. As a result, immediately after the power is turned on, the relationship between the lamp current I and the lamp voltage V becomes as shown in characteristic (2) in FIG. When the amplifier circuit 11 is saturated before the fixed time T elapses, the relationship between the lamp current I and the lamp voltage V becomes as shown in characteristic (2) in FIG. Further, if the amplifier circuit 11 is not saturated even after the predetermined time T has elapsed, the characteristic (2) shifts to the characteristic (2). Lamp R
If L is a high-pressure discharge lamp, it starts discharging at point P1 and moves to point P2. Characteristic (2) allows a larger lamp current I to flow than characteristic (2) in order to quickly stabilize the discharge lamp. When the discharge lamp becomes stable, it gradually moves from point P2 to point P3. The timer time T is set to the time required for the discharge lamp to shift from characteristic (2) to characteristic (2). As a result, the discharge lamp performs rated operation with characteristic (2).

Next, if the lamp RL is an incandescent lamp, after turning on the power switch SW, it operates at point X of characteristic (2). This operating point X provides less power than the incandescent lamp is rated for. When the timer 12 measures a certain period of time T, the characteristic ■ changes to the characteristic ■, so the operating point changes from the X point to the Y point. This operating point Y is set to the rated output of the incandescent lamp. As a result, the incandescent lamp performs its rated operation with characteristic (■). In this embodiment, for example, the lamp voltage of the discharge lamp is 90V.
It is particularly effective when the lamp voltage of an incandescent lamp is about 12V. In this way, the drooping characteristics of the lighting device (
If the output characteristics (output characteristics) are changed over time, there is no need to separately provide a lamp discrimination means as in the above-mentioned embodiments, and the circuit configuration becomes simple.

[0040]

Effects of the Invention In the discharge lamp lighting device according to claim 1, when another type of lamp such as an incandescent lamp having a common socket is connected in place of the discharge lamp lit by the first lighting means. However, the type of lamp can be determined by the lamp discrimination means,
There is an effect that the second lighting means can cause normal lighting.

[0041] In the discharge lamp lighting device according to the second aspect of the invention, in the lighting device which shifts the discharge lamp to the rated lighting state after a certain period of time has elapsed since the power is turned on, the incandescent lamp can be turned on at the rated lighting state after the certain period of time has elapsed. Since the output characteristics of the lighting device are switched, there is an effect that both discharge lamps and incandescent lamps can be lit at their rated values without providing lamp discrimination means.

Furthermore, when the discharge lamp lighting device of the present invention is used in a vehicle headlamp, even if the discharge lamp goes out of operation, a halogen bulb that is highly available on the market can be used as an emergency, ensuring safety. It has the advantage of being possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the present invention.

FIG. 2 is a circuit diagram of a first embodiment of the present invention.

FIG. 3 is an operation waveform diagram showing the lighting operation of the discharge lamp according to the first embodiment of the present invention.

FIG. 4 is an operation waveform diagram showing the lighting operation of the incandescent lamp according to the first embodiment of the present invention.

FIG. 5 is a circuit diagram of a second embodiment of the present invention.

FIG. 6 is an operation waveform diagram showing a lighting operation of a discharge lamp according to a second embodiment of the present invention.

FIG. 7 is an operation waveform diagram showing a lighting operation of an incandescent lamp according to a second embodiment of the present invention.

FIG. 8 is a circuit diagram of a third embodiment of the present invention.

FIG. 9 is a circuit diagram of a fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram of the operation of a timer used in the fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram of the operation of the amplifier circuit used in the fourth embodiment of the present invention.

FIG. 12 is a characteristic diagram showing the output characteristics of the fourth embodiment of the present invention.

[Explanation of symbols]

1 First lighting means 2 Second lighting means 3 Lamp discrimination means RL lamp SW Power switch V1 Power supply

Claims (2)

[Claims] 1. A first lighting means for lighting a discharge lamp, a second lighting means for lighting a lamp other than a discharge lamp,
a lamp discriminating means for discriminating the type of lamp by applying a constant low voltage to the lamp and detecting the presence or absence of a lamp current before an operation of lighting the discharge lamp; Discharge lamp lighting characterized by having a switching means for lighting the discharge lamp using the first lighting means if it is a compatible discharge lamp, and lighting the lamp using the second lighting means for other lamps. Device. 2. A discharge lamp lighting device configured to start and light a discharge lamp that transitions to a rated state after a predetermined period of time after power is turned on, wherein the incandescent lamp is lit at a lower than the rated state before the elapse of the predetermined period of time. . A discharge lamp lighting device, comprising means for changing the output characteristics of the lighting device so that the incandescent lamp is lit at the rated value after the predetermined period of time has elapsed.