JPH0368519B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a high-pressure discharge lamp lighting device in which a heater is attached to a high-pressure discharge lamp to improve the rise of luminous flux at startup.

[Prior Art] A high-pressure discharge lamp is equipped with an arc tube filled with a rare gas for starting, mercury, and a metal halide, but such a discharge lamp is started by applying a high-pressure pulse when it is in a low temperature state, for example. Even when the lamp is turned on, the mercury and metal halides sealed in the arc tube are hardly evaporated, so the rise of the luminous flux is slow and there is a problem in that it takes a considerable amount of time for the luminous flux to reach a stable state. For this reason, it may be possible to heat the arc tube by attaching a heater to the arc tube to accelerate the evaporation of the mercury and metal halides sealed therein, thereby improving the rise of the luminous flux during startup.

[Problems to be solved by the invention] However, if this method of heating the high-pressure discharge lamp with a heater is adopted, the power consumption by the heater is large, which causes problems when the high-pressure discharge lamp is driven using a battery. There is. For this reason, for example,
A high-pressure discharge lamp is heated by a heater, but once the high-pressure discharge lamp starts lighting operation, it is conceivable to stop energizing the heater after a certain period of time to reduce the power consumption by the heater as much as possible.
However, if the time period during which the heater is energized after the high-pressure discharge lamp is turned on is made constant, the following problems arise.

(a) Setting the energization time to the heater after the high-pressure discharge lamp is turned on short in anticipation of sufficient preheating before starting the lighting, for example, when turning on the high-pressure discharge lamp within a short time after the start of energization to the heater. There is a problem in that preheating is insufficient, and as a result, the power supply to the heater is stopped before the luminous flux of the high-pressure discharge lamp has sufficiently risen, and it takes a long time for the luminous flux to rise.

(b) On the other hand, if you set the energization time to the heater after the high-pressure discharge lamp is turned on for a long time in anticipation of insufficient preheating before starting the lighting, for example, the high-pressure discharge lamp may be turned on after a while after the heater starts being energized. If you want to turn it on, the preheating will be more than enough. That is, even after the luminous flux of the high-pressure discharge lamp has sufficiently risen, it is heated by the heater, resulting in an overshoot of the luminous flux and a problem of shortening the life of the discharge lamp.

This invention was made to solve this problem, and it controls the amount of power supplied to the heater after lighting according to the heating state of the high-pressure discharge lamp by the heater before lighting starts. It is an object of the present invention to provide a high-pressure discharge lamp lighting device that can always obtain a good rise in luminous flux and that is free from the risk of overshooting of the luminous flux.

[Means for Solving the Problems] The present invention provides a high-pressure discharge lamp that is connected to a power source and includes a lighting control circuit that starts and controls lighting of a high-pressure discharge lamp, and a heating heater attached to the high-pressure discharge lamp. The electric lamp lighting device is provided with a control circuit that controls the heating of the high-pressure discharge lamp by the heating heater, and the control circuit responds to the heating of the high-pressure discharge lamp by the heating heater before the lighting of the high-pressure discharge lamp starts. a voltage level raising means for raising the voltage level at a relatively slow speed, and then raising the voltage level at a relatively fast speed in response to the start of lighting of the high pressure discharge lamp; A stop control means is provided which compares the voltage level with a preset reference voltage level and stops the heating of the high pressure discharge lamp by the heating heater when the voltage level reaches the reference voltage level.

Further, the present invention further includes a voltage level lowering means for lowering the voltage level when the power supply to the heating heater and the lighting control circuit is stopped.

[Function] In the present invention, the heating time by the heater after lighting the high-pressure discharge lamp is such that the heating time before lighting the high-pressure discharge lamp has a negative correlation with the heating time after lighting the high-pressure discharge lamp. If the heating time of the discharge lamp by the heater before the high-pressure discharge lamp starts lighting is long enough, the heating time of the heater after the high-pressure discharge lamp starts lighting can be shortened to prevent the luminous flux from overshooting. Furthermore, when the heating time of the discharge lamp by the heater before starting lighting of the high-pressure discharge lamp is relatively short, the heating time of the heater after lighting the high-pressure discharge lamp can be lengthened to improve the rise of the luminous flux.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a battery as a power source, and a lighting control circuit 3 is connected to this battery 1 via a lighting switch 2. A high pressure discharge lamp 4 is connected to the lighting control circuit 3. The lighting control circuit 3 includes a starting circuit 31 that generates a high-voltage pulse to start the high-pressure discharge lamp 4, and the high-pressure discharge lamp 4.
The lighting circuit 32 keeps the lighting on.

Further, a heater 7 attached to the high pressure discharge lamp 4 is connected to the battery 1 through a heater switch 5 and a normally open contact 6m of a relay 6 in series.

Reference numeral 8 denotes a control circuit, and this control circuit 8 connects a series circuit of a resistor 9 and a capacitor 10 to the battery 1 via a lighting switch 2, and also connects a series circuit of resistors 11 and 12 via a heater switch 5. are doing. The resistors 9, 11 and the capacitor 10 form voltage level increasing means. The resistor 12 also forms voltage level lowering means. Further, the control circuit 8 is provided with a first NAND gate 13 of a two-input type, one input terminal of which is connected to the connection point between the lighting switch 2 and the resistor 9 via an inverter 14, and the other input terminal of the first NAND gate 13. The connection point between the heater switch 5 and the resistor 11 is directly connected. Further, the control circuit 8 is provided with a comparator 15, and one input terminal of the non-inverting input terminal (+) is connected to the connection point between the resistor 9 and the capacitor 10 and the connection point between the resistors 11 and 12. A voltage source 16 that generates a reference voltage V _REF is connected to the inverting input terminal (-) which is the other input terminal.

Furthermore, the control circuit 8 is provided with a two-input type second NAND gate 17 and an NPN type transistor 18, and each input terminal of the second NAND gate 17 is connected to an output terminal of the first NAND gate 13 and an output terminal of the comparator 15. The output terminal of the second NAND gate 17 is connected to the base of the transistor 18. The relay 6 is connected to the battery 1 through the heater switch 5 and transistor 18 in series.
A surge absorbing diode 19 is connected in parallel to the coil 6c. The comparator 15, the voltage source 16 and the second NAND gate 17 form a stop control means.

Next, the operation of this embodiment having such a configuration will be explained with reference to FIG. Note that A in FIG. 2 shows the operation timing of each part when heating is sufficient before starting lighting, and B shows the operating timing of each part when heating before starting lighting is insufficient.

First, regarding case A, when the lighting switch 2 is turned off as shown in a of FIG. 2 and the heater switch 5 is turned on as shown in c of FIG. 2, the state shown in b of FIG. like inverter 14
Since the output of the first NAND gate 13 is at a high level, both inputs of the first NAND gate 13 are at a high level, and its output becomes a low level as shown in d of FIG. Further, since a voltage is generated across the resistor 12, the capacitor 10 is charged at a predetermined time constant as shown in e of FIG. However, this capacitor 1
Since the voltage of 0 is lower than the reference voltage V _REF , the output of the comparator 15 becomes a low level as shown at f in FIG. However, the second NAND gate 17
Since the inputs to both will be low level, the output will be high level as shown in g in Figure 2,
This turns on the transistor 18, turning on the relay 6 and closing its normally open contact 6m, as shown at h in FIG. In this way, power supply to the heater 7 is started, and the high pressure discharge lamp 4 is heated in advance. That is, it is preheated.

Even if this preheating state continues for a relatively long time, the charging speed of capacitor 10 is slow because charging is performed only through resistor 11, and therefore the charging voltage does not increase rapidly. After a while, when the lighting switch 2 is turned on as shown in FIG. 2A, the lighting control circuit 3 operates and the high pressure discharge lamp 4 starts lighting. At this time, the high-pressure discharge lamp 4 has been heated by the heater 7 for a relatively long period of time, so its temperature is high, and the lamp starts and lights up with good luminous flux rising characteristics.

Also, when the lighting switch 2 is turned on, b in Fig. 2
The output of the inverter 14 becomes low level as shown in FIG. 2, and the output of the first NAND gate 13 becomes high level as shown in d of FIG. At this time, since the input from the comparator 15 to the second NAND gate 17 maintains a low level, the second
The output of the NAND gate 17 maintains a high level state. Furthermore, when the lighting switch 2 is turned on, the capacitor 10 is also charged via the resistor 9, so that the charging speed becomes faster as shown in e of FIG. Since this capacitor 10 has already been charged to a certain level during the preheating period, when the lighting switch 2 is turned on, its charging voltage reaches the reference voltage V _REF in a relatively short period of time. When the charging voltage reaches the reference voltage V _REF , the output of the comparator 15 is inverted and becomes a high level as shown at f in FIG. 2. Since all inputs to the second NAND gate 17 are at high level, the output thereof is at low level, transistor 18 is turned off, relay 6 is turned off as shown in h in FIG. 2, and heater 7 is energized. will be stopped. This state continues as long as the lighting switch 2 is on.

In this way, if the high-pressure discharge lamp 4 is sufficiently heated by the heater 7 before starting lighting, the power supply to the heater 7 will be stopped within a short time after the high-pressure discharge lamp 4 starts lighting operation. This prevents the light beam from overshooting.

If the lighting switch 2 is then turned off, the output of the first NAND gate 13 becomes low level, so even if the output of the comparator 15 maintains a high level, the output of the second NAND gate 17 becomes high level and the heater 7 energization will be resumed. Thereafter, the power supply to the heater 7 is stopped by turning off the heater switch 5.

Regarding case B, in this case as well, if the heater switch 5 is turned on as shown in c of Fig. 2 while the lighting switch 2 is off as shown in a of Fig. 2, then as shown in Fig. 2 Since the output of the inverter 14 is at a high level as shown in b, the first
Both inputs of the NAND gate 13 become high level, and the output becomes low level as shown in d of FIG. Further, since a voltage is generated across the resistor 12, the capacitor 10 is charged at a predetermined time constant as shown in e of FIG. However, since the voltage of this capacitor 10 is lower than the reference voltage V _REF , the output of the comparator 15 becomes a low level as shown at f in FIG. 2. Since all the inputs to the second NAND gate 17 become low level, the output becomes high level as shown in g in FIG. As shown, the relay 6 is turned on and its normally open contact 6m is closed. In this way, power supply to the heater 7 is started, and the high pressure discharge lamp 4 is heated in advance. That is, it is preheated.

If the lighting switch 2 is turned on as shown in FIG. 2A before this preheating state has been sufficiently continued, the lighting control circuit 3 will operate and the high pressure discharge lamp 4 will start lighting.

Furthermore, when the lighting switch 2 is turned on, the capacitor 10 is also charged via the resistor 9, so that the charging speed becomes faster as shown in e in FIG. This capacitor 10 is not significantly charged during the preheating period, so its charge level is low. Even if the lighting switch 2 is turned on and the charging speed of the capacitor 10 becomes faster, it takes some time for the charging voltage to reach the reference voltage V _REF . Even when the high-pressure discharge lamp 4 starts lighting, the heater 7 continues to be energized for a while. Therefore, even if the temperature of the high-pressure discharge lamp 4 is not very high at the start of the lighting operation, as the lighting operation progresses, the discharge lamp 4 is heated by the heater 7 and its temperature is increased, resulting in a good rise in luminous flux. The light will come on when the engine starts.

Then, when the high-pressure discharge lamp 4 shifts to stable lighting, that is, when the luminous flux rises sufficiently, the charging voltage of the capacitor 10 reaches the reference voltage V _REF , the transistor 18 and the relay 6 are turned off, and the heater 7 energization is stopped.

In this way, when the high-pressure discharge lamp 4 is not sufficiently heated by the heater 7 before lighting, even after the high-pressure discharge lamp 4 is started and turned on, the power to the heater 7 is maintained for a relatively long time. The high-pressure discharge lamp 4 is heated as the lighting progresses, and its luminous flux has a good rise, so that it quickly shifts to a stable lighting state.

Further, when the lighting switch 2 and the heater switch 5 are respectively turned off, charging of the capacitor 10 is stopped and the charge in the capacitor 10 is discharged via the resistor 12. This causes the level of capacitor 10 to drop.

To re-light the high-pressure discharge lamp 4 in this state, the lighting switch 2 and the heater switch 5 can be turned on again, but if the lighting switch 2 and the heater switch 5 have been off for a long time, the lighting switch 2 and the heater switch The level of the capacitor 10 when the capacitor 5 is turned on is greatly reduced.
Also, at this time, the temperature of the high pressure discharge lamp 4 is relatively low. Therefore, in such a case, even after the high-pressure discharge lamp 4 is started and lit, the heater 7 is kept energized for a relatively long time to heat the high-pressure discharge lamp 4. Also, if the time that the lighting switch 2 and the heater switch 5 are turned off is short, the lighting switch 2
Also, the level of the capacitor 10 when the heater switch 5 is turned on does not drop that much. Further, at this time, the temperature of the high pressure discharge lamp 4 is in a relatively high state. Therefore, in such a case, once the high-pressure discharge lamp 4 is started and turned on, the heater 7 is turned on in a relatively short period of time.
The power supply to is stopped.

In this manner, when the high pressure discharge lamp 4 is turned on once, then turned off, and then turned on again, the heating time by the heater 7 after the lamp is turned on can be controlled by the length of time the high pressure discharge lamp is turned off. Therefore, even in this case, the rise of the luminous flux is good.

Further, in the above embodiment, the lighting switch 2 and the heater switch 5 are turned on and off independently, but they may be turned on and off automatically in conjunction with other systems (for example, the present invention shown in FIG. (Two sets of high-pressure discharge lamp lighting devices may be linked together.) There are various possible ways to use the high-pressure discharge lamp lighting device of the present invention.

[Effects of the Invention] As detailed above, according to the present invention, the heating time of the heater after lighting is controlled according to the heating time of the high-pressure discharge lamp by the heating heater before lighting starts, so that a good luminous flux is always maintained. Therefore, it is possible to provide a high pressure discharge lamp lighting device which can obtain a rise of 100% and is free from the possibility of overshooting of the luminous flux.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing an embodiment of this invention, Fig. 2 is a circuit diagram showing an embodiment of the present invention;
The figure is a timing diagram showing the operation of each part in the same embodiment. 1...Battery, 3...Lighting control circuit, 4...
...High pressure discharge lamp, 6...Relay, 7...Heating heater, 8...Control circuit.

Claims (1)

[Scope of Claims] 1. A high pressure discharge lamp lighting device comprising: a lighting control circuit connected to a power source to start and control lighting of a high pressure discharge lamp; and a heating heater attached to the high pressure discharge lamp; A control circuit is provided for controlling heating of the high-pressure discharge lamp by the heating heater, and the control circuit responds when heating of the high-pressure discharge lamp by the heating heater is started before lighting of the high-pressure discharge lamp is started. a voltage level raising means for raising the voltage level at a relatively slow speed, and subsequently raising the voltage level at a relatively fast speed in response to the start of lighting of the high pressure discharge lamp; A high-pressure discharge lamp comprising a stop control means that compares a voltage level with a preset reference voltage level and stops heating the high-pressure discharge lamp by the heating heater when the voltage level reaches the reference voltage level. Electric light lighting device. 2. In a high-pressure discharge lamp lighting device that is connected to a power source and includes a lighting control circuit that starts and controls lighting of a high-pressure discharge lamp, and a heating heater attached to the high-pressure discharge lamp, the high-pressure discharge by the heating heater is A control circuit for controlling heating of the electric lamp is provided, and the control circuit is configured to control heating at a relatively slow speed in response to the heating of the high-pressure discharge lamp by the heating heater being started before the lighting of the high-pressure discharge lamp starts. Voltage level raising means for raising the voltage level and subsequently raising the voltage level at a relatively fast speed in response to the start of lighting of the high pressure discharge lamp, and a voltage level by this raising means being set in advance. stop control means for comparing the voltage level with a reference voltage level and stopping heating of the high pressure discharge lamp by the heating heater when the voltage level reaches the reference voltage level; A high-pressure discharge lamp lighting device comprising voltage level lowering means for lowering the voltage level when stopped.