JPH0547484A - Discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To provide a discharge lamp lighting device which can keep the lighting condition of a HID lamp even when the apparent voltage of a storage battery is not more than the rated voltage of the discharge lamp lighting device, and not less than the operation stop voltage. CONSTITUTION:A discharge lamp lighting device 1 is provided with a voltage increasing circuit 3 for increasing the voltage of an input voltage VE, an inverter circuit 4 for converting a DC voltage-increased by the voltage increasing circuit 3 into AC voltage of high frequency, an igniter circuit 5 by which pulse voltage of high voltage is applied to an HID lamp 2 at the starting time, and whereby starting the lighting thereof, and with a luminous flux starting speed control part 6. A low voltage detection part 7 is also provided, by which a signal for stopping the operation of the luminous flux starting speed control part 6 is output to the luminous flux starting speed control part 6, when the voltage value of the input voltage VE detected is not more than a fixed level.

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 such as an HID lamp.

[0002]

2. Description of the Related Art FIG. 5 shows wiring in a vehicle for lighting a HID lamp 2 of a vehicle headlight using a discharge lamp lighting device of this type. A storage battery BT is connected via a switch SW and an electric wire L. It is connected to the discharge lamp lighting device 1, the discharge lamp lighting device 1 is operated by using the storage battery BT as a power source, and the HID of the vehicle headlamp is obtained.
The lamp 2 is turned on.

By the way, in the case of mounting on such a vehicle, one electric storage battery BT operates various electric components such as the engine starter cell motor M, the in-vehicle computer CPU, and the radio RA. The voltage fluctuates. Further, the connection between the discharge lamp lighting device 1 and the storage battery BT is made by a considerably long electric wire L via a switch SW or the like, but since the electric wire diameter cannot be obtained more than necessary in terms of cost, weight, etc., the storage battery BT The internal resistance of the electric wire L between the discharge lamp lighting devices 1 is large.

On the other hand, the discharge lamp lighting device 1 is an H lamp for a vehicle headlamp.
Considering that it is used to light the ID lamp 2,
For safety, it is necessary to obtain a sufficient amount of light immediately after the switch SW is turned on. Therefore, unlike a general discharge lamp lighting device, a means for improving the luminous flux rising speed is added. Generally, the HID lamp 2 takes a long time from the start to the emission of the rated luminous flux.

By the way, as shown in FIG. 6, a means for improving the luminous flux rising speed is that the lamp voltage Vla is the rated lamp voltage (section B) immediately after the start of the HID lamp 2.
As long as it is sufficiently low, a lamp current Ila that is several times as high as that in the case of a normal discharge lamp lighting device (shown by a broken line B) is supplied, and during that time, a lamp power twice as high as the rated lamp power. Supply power.

On the other hand, the voltage of the storage battery BT fluctuates due to various factors as described above, and the rated voltage of the 12V type vehicle storage battery BT is usually 10V to 16V. However, when a heavy load such as the engine start cell motor M is operated, the voltage may drop to about 5 to 9V. On the other hand, the discharge lamp lighting device 1 uses a FET or a bipolar transistor as a switching element and uses an IC circuit or the like for its control, so that it does not operate when the power supply voltage is insufficient, and is unstable if only a part of the used element operates. It is possible that this may result in damage to the device.

From the above, the lower limit of the operating voltage of the discharge lamp lighting device 1 is determined, or in order to prevent destruction,
In some cases, a protection circuit that does not operate at a predetermined voltage or lower may be added. FIG. 7 shows the relationship between the voltage of the storage battery BT and the operating voltage of the discharge lamp lighting device 1. Under such conditions, the operation of the conventional vehicle discharge lamp lighting device 1 will be considered next.

FIG. 8 shows an equivalent circuit in which the discharge lamp lighting device 1 is connected to the storage battery BT under the above conditions. Here, the discharge lamp lighting device 1 has a booster circuit 3 that boosts the input voltage V _E to a voltage (generally several hundreds V) required to maintain lighting of the HID lamp 2, and the boosted DC voltage that is a high-frequency or rectangular-wave AC voltage. Inverter circuit 4 that converts the power to HID lamp 2 and supplies power to HID lamp 2, and several K when starting HID lamp 2.
~ A luminous flux rising control for controlling the operations of the igniter circuit 5 for generating and applying a pulse voltage of several tens of KV to the HID lamp 2 for starting and lighting and the inverter circuit 4 so as to improve the luminous flux rising speed as described above. It is composed of the raising speed control unit 6.

When the switch SW is turned on, the circuit current I _B = immediately before the discharge lamp lighting device 1 starts operating.
Since it is 0, the input voltage V _E is equal to the voltage V _{B of the} storage battery BT, and V _E = V _B. When the discharge lamp lighting device 1 starts the lighting operation, I _B > 0, and a voltage drop occurs due to the internal resistance r of the wire L, so that V _E = V _B −V _D. V _D : Falling voltage Here, if the luminous flux rising speed control unit 6 operates for a certain period from the time when the switch SW is turned on, the HID lamp 2 is supplied with excessive power, and therefore the input power of the discharge lamp lighting device 1 is increased. Also increases.

If the input power of the discharge lamp lighting device 1 at the time of rated lighting of the HID lamp 2 is W _ES and the maximum input power in the starting process is W _EM , then W _EM > W _{ES, and} therefore the discharge lamp of each discharge lamp. If the input currents of the lighting device 1 are I _BS and I _BM , I
_BM > I _BS , and in the starting process, I _BX = I _BM −I _BS
Input current is required.

FIG. 9 shows an example of the relationship between the voltage V _{B of the} storage battery BT and the input voltage V _E of the discharge lamp lighting device 1. When the input current I _B is large, the voltage drop V of the internal resistance r is shown. _{Since D} also becomes large, the input voltage _E and the voltage V of the storage battery BT
The difference with _B widens. When V _B = V _B1 or more, the input voltage V _E greatly drops immediately after the start, for example, at the point A, but since it is the operation stop voltage V _ESTP or more, the operation of the discharge lamp lighting device 1 does not stop.

If V _B = V _B1 or less, however, the input voltage V _E drops to the operation stop voltage V _ESTP or less immediately after the start, as at the point B, so the operation of the discharge lamp lighting device 1 stops. Then, since the input current I _B = 0, V _E = V _B1 , and the discharge lamp lighting device 1 operates again, and V _E <V _ESTP again.
Then, the operation of the discharge lamp lighting device 1 is stopped.

[0013]

As described above, in the conventional vehicle-mounted discharge lamp lighting device 1, the operation and the operation stop are alternately repeated when the voltage V _B across the storage battery BT becomes a certain value or less. There was a problem that the HID lamp 2 blinks repeatedly and flickers. The present invention has been made in view of the above problems, and an object thereof is to provide an HID lamp even if the apparent voltage of the storage battery is equal to or lower than the rated voltage of the discharge lamp lighting device and equal to or higher than the operation stop voltage. An object of the present invention is to provide a discharge lamp lighting device capable of maintaining the lighting.

[0014]

In order to achieve the above-mentioned object, the present invention uses a storage battery as a power source, raises the storage battery voltage, converts it into an AC voltage, and lighting means for lighting an HID lamp. , H for a certain period from the time of device startup
In a discharge lamp lighting device provided with a luminous flux rising speed control means for controlling the output of the lighting means so as to rapidly raise the light quantity of the ID lamp to a predetermined value, the luminous flux rising means is turned off when the power supply voltage is below a certain value. It is provided with a low voltage detecting means for operating.

The range of the constant value of the power supply voltage is set to be lower than the lower limit value of the rated operating voltage range of the lighting means and higher than the power supply voltage value at which the lighting means does not operate.

[0016]

According to the discharge lamp lighting device of the present invention, the lighting means is provided with the low voltage detecting means for bringing the luminous flux rising speed control means into the inoperative state when the power supply voltage is equal to or lower than a constant value. Since the luminous flux rising speed control means is not operated with a low power supply voltage that drops to a non-operating voltage, it is possible to keep the HID lamp lit without a malfunction of the lighting means even with a low power supply voltage.

[0017]

EXAMPLES The present invention will be described below with reference to examples. (Embodiment 1) FIG. 1 shows the overall configuration of this embodiment.
Similarly to the conventional example, the lighting means boosts the input voltage V _E by a booster circuit 3, an inverter circuit 4 that converts the direct current boosted by the booster circuit 3 into a high-frequency AC voltage, and an HID lamp 2
It is the same in that it is configured with an igniter circuit 5 that applies a high-voltage pulse voltage at the time of starting and starts and lights up, and a light flux rising speed control unit 6 is further provided.
_{If E} is detected and the voltage value is equal to or lower than a certain value, a low voltage detection unit 7 that outputs a signal for stopping the operation of the light flux rising speed control unit 6 to the light flux rising speed control unit 6 is provided. Different from the conventional example.

FIG. 2 shows a specific circuit of this embodiment.
Boosting circuit 3 turns on / off the switching element Q ₁ in the drive circuit 13, stored energy in the choke L ₁ at the time of on, the capacitor C ₁ by flowing in the capacitor C ₁ through the diode D ₁ and the energy at off charge is composed of the step-up chopper circuit for obtaining a high DC voltage V _DC than the input voltage V _E, the DC voltage V _DC to output monitored by constant voltage controller 8, so that the DC voltage V _DC is constant In the drive circuit 13, the switching element Q ₁ is turned on /
A signal for controlling the off period is given.

The inverter circuit 4 has two switching elements Q ₂ and Q ₃ connected in series, and is alternately turned on and off by the gate signals from the drive circuits 9 ₁ and 9 _2, and the HID lamp 2 via the igniter circuit 5. It is composed of a well-known Hafu bridge type circuit in which an alternating current is passed through. On the other hand, the light flux rising speed control unit 6 changes the operating frequency of the inverter circuit 4 by changing the cycle of the gate signal supplied from the drive circuits 9 ₁ , 9 ₂ of the inverter circuit 4 to the switching elements Q ₁ , Q ₃ . A V-F conversion oscillator 10 is provided which gives a frequency signal corresponding to the lamp voltage Vla input through the normally closed side of the relay contact rs to the drive circuits 9 ₁ and 9 ₂ . The V-F conversion oscillator 10 lowers the operating voltage of the inverter circuit 4 to increase the output of the inverter circuit 4 while the lamp voltage Vla immediately after the start is low, thereby increasing the output of the inverter circuit 4 and driving the low-frequency signal that makes the luminous flux rising speed rapid. 9 ₁ and 9 _2, and by giving a high frequency signal to the drive circuits 9 ₁ and 9 ₂ as the lamp voltage Vla rises, the operating frequency of the inverter circuit 4 is increased so that the output of the inverter circuit 4 approaches the rating. It has become.

The knot gate NT is for inverting the frequency signal and supplying it to the drive circuit 9 ₂ . On the other hand, the low voltage detector 7 is provided with a comparator 11 which compares the input voltage V _E with the reference voltage Vref and sets the output to “H” when the input voltage V _E falls below the reference voltage Vref. An exciting current is passed through the coil of the relay RY of the luminous flux rising speed controller 6 by the output of "H" 11 to reverse the relay contact rs to the normally open side.

That is, when the relay contact rs is inverted to the normally open side, the input voltage of the VF conversion oscillator 10 is a constant value V.
₁ and the constant value V ₁ is used as the rated lighting lamp voltage Vl.
By setting the same as “a”, when the input voltage V _E is lower than the reference voltage V ref, the luminous flux rising speed control unit 6
Does not perform the operation of increasing the rising speed of the luminous flux, but keeps lighting until the rated lighting.

Therefore, the reference voltage Vref is V shown in FIG.
By setting to _E1 , the operation stop voltage V _ESTP <V _E <
In the range of V _E1 , since the operation of the luminous flux rising speed control unit 6 is stopped as described above, the drop voltage V _D of the internal resistance r of the electric wire L from the storage battery BT to the discharge lamp lighting device 1 is small, and V _E < Since it does not fall to V _ESTP , the lighting can be maintained until the rated lighting. Point A in FIG.
At the point B, when the input voltage V _E is equal to or higher than the reference voltage V ref, the luminous flux rising speed control unit 6 performs an operation for increasing the rising speed of the luminous flux to reach the rated lighting.
_{Since ESTP} <V _E <V _E1 , the operation of the luminous flux rising speed controller 6 is stopped, and the lighting is maintained until the rated lighting as described above.

(Embodiment 2) By the way, in order to speed up the luminous flux rising speed and quickly operate the inverter circuit 4 and the igniter circuit 5, the booster circuit 3 is rapidly operated from the switch-on to generate the DC voltage V _DC . There is also a method of obtaining it immediately, but at this time, the constant voltage controller 8 turns on the switching element Q ₁ with a wide on-duty, so that the circuit current I _B becomes much larger than that at the rated time. Therefore, the drop voltage V _D of the internal resistance r of the electric wire L may cause the discharge lamp lighting device 1 to malfunction.

Therefore, in the present embodiment, the switch of the booster circuit 3
Element Q₁Switching with resistor Rx connected in series to
Element Q₁Current is detected and this detected value is the reference value Vref₀To
Inverts the output of comparator 12 to "H" when it falls below
I am doing it. And the reference voltage of the low voltage detection unit 7
Vref is the input voltage V_EFalls below the output of comparator 11.
When the force becomes “H”, both comparators 11 and 12
NAND gate ND to input the output of₁Output of "L"
Input with the output of the constant voltage controller 8.
NAND gate AD₁Switching the output of "L" to "L"
Element Q ₁Stop the operation of. Switching by this
Element Q₁Current is limited and the circuit current I_BIs smaller
As a result, the voltage output from the booster circuit 3 reaches a predetermined value.
Takes time, but circuit current I_BDrop voltage V_Dso
Since the discharge lamp lighting device 1 does not malfunction.
It

That is, in this embodiment, the luminous flux rising speed controller 6 is composed of an AND gate AD ₁ , a NAND gate ND, a comparator 12, and a resistor Rx.

[0026]

The present invention is provided with the low voltage detecting means which is constructed as described above and which makes the luminous flux rising speed control means inoperative when the power supply voltage is below a certain value.
Even when the light flux rising means is operated, the light flux rising speed control means is not operated at such a low power supply voltage that the power supply voltage drops to a voltage at which the lighting means is inoperative. The HID lamp can be kept lit without malfunction of the lighting means.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment of the present invention.

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

FIG. 3 is an operation explanatory diagram of the first embodiment of the present invention.

FIG. 4 is a circuit configuration diagram of a second embodiment of the present invention.

FIG. 5 is a circuit configuration diagram showing an example of use of a discharge lamp lighting device mounted on a vehicle.

FIG. 6 is an explanatory diagram of a lamp voltage-a lamp current of a discharge lamp lighting device mounted on a vehicle.

FIG. 7 is an explanatory diagram of the relationship between the operation of the discharge lamp lighting device mounted on the vehicle and the storage battery.

FIG. 8 is a circuit configuration diagram of a conventional example.

FIG. 9 is an operation explanatory diagram of a conventional example.

[Explanation of symbols]

 1 Discharge lamp lighting device 2 HID lamp 3 Booster circuit 4 Inverter circuit 5 Igniter circuit 6 Luminous flux rising speed control unit 7 Low voltage detection unit

Claims (2)

[Claims] 1. A storage battery is used as a power source, the power supply voltage from this storage battery is raised, and at the same time converted into an AC voltage,
A discharge lamp lighting device comprising: a lighting means for lighting the D lamp; and a light flux rising control means for controlling the output of the lighting means so as to rapidly raise the light quantity of the HID lamp to a predetermined value from a time when the device is started. A discharge lamp lighting device, comprising: a low-voltage detecting unit that brings the luminous flux rising speed control unit into a non-operating state when the power supply voltage is equal to or lower than a certain value. 2. A constant value range of the power supply voltage is set to a value lower than a lower limit value of a rated operating voltage range of the lighting means and higher than a power supply voltage value at which the lighting means does not operate. The discharge lamp lighting device according to claim 1.