JP2005209580A - High pressure discharge lamp lighting device and automobile headlamp - Google Patents

Abstract

【Task】
A high-pressure discharge lamp lighting device capable of discharging the charge of the capacitive element, returning the lighting circuit to the reset state, and immediately re-lighting the high-pressure discharge lamp when the DC power supply is cut off, and an automobile using the same Provide headlamps.
[Solution]
The high-pressure discharge lamp lighting device includes a high-pressure discharge lamp HPL; a lighting circuit OC including a switching regulator DC / DC having a capacitive element C1 equivalently connected to an input end and an input end connected to a DC power source DC; A pulse generation circuit IG; a lighting detection means LD, a high voltage pulse stopping means PS for stopping and holding the high voltage pulse application when the high pressure discharge lamp does not start even if the application of the high voltage pulse is continued for a predetermined time, and a switching regulator A control circuit CC including a switching regulator stop control means SS for stopping the operation after the operation of the switching regulator is continued for a predetermined time when discharging the capacitive element to discharge the capacitive element.
[Selection]
FIG.

Description

  The present invention relates to a high-pressure discharge lamp lighting device for lighting a high-pressure discharge lamp and an automobile headlamp using the same.

  As light sources for automobile headlamps, halogen bulbs and high-pressure discharge lamps are frequently used. The halogen lamp has an advantage that the rated lamp power is 55 to 60 W, the luminous flux rises quickly, and the lighting device is inexpensive, but there is a problem that the power consumption is large.

  On the other hand, the high-pressure discharge lamp has a rated power consumption of 35 W and has the advantage that the luminous flux is large and has a long life while the power consumption is small, while the luminous flux rises slowly. For this reason, it becomes a big obstacle for the vehicle headlamp which requires a quick luminous flux rise. Therefore, it has become possible to make up for the above-mentioned drawbacks by configuring the lamp power to be greater than the rated power immediately after starting the high-pressure discharge lamp. As a result, the above-mentioned advantages are large and attractive, and despite the fact that both the lamp and the lighting device are expensive, there are strong demands for ensuring safe driving of vehicles and energy savings. Discharge lamps are rapidly spreading as a light source for automobile headlamps.

  On the other hand, high-pressure discharge lamps for automobile headlamps include metal halide lamps containing mercury as a discharge medium (hereinafter referred to as “mercury-containing lamps” for convenience) and metal halide lamps not containing mercury (hereinafter referred to as “mercury-free lamps” for convenience). ") Is known. The former is configured to obtain a required lamp power by enclosing mercury as a buffer substance in addition to a luminescent metal halide. In order to turn on this mercury-containing lamp for automotive headlamps, immediately after starting, a large lamp power of about twice the rated power is continuously turned on for about 1 second, and then it is sequentially turned on toward the stable lamp power. Control to reduce power.

  On the other hand, the latter uses a metal having a high vapor pressure instead of mercury and relatively low light emission in the visible range, such as Zn or / and In as a buffer substance and / or luminescent substance in the form of a halide. Enclosed. To turn on this mercury-free lamp for automobile headlamps, immediately after starting, a large lamp power of about 2 to 2.5 times the rated power is continuously applied for about 4 seconds, and then the lamp power at the time of stable Control is performed so that the input power is gradually reduced toward the.

  Further, a high-pressure discharge lamp for an automobile headlamp is required to be instantly restarted regardless of whether it is a mercury-containing lamp or a mercury-free lamp. For this purpose, the high-pressure discharge lamp lighting device includes a high voltage pulse generation circuit called an igniter, and is configured so that a high voltage pulse is applied between a pair of electrodes at the time of start, and the start is instantaneously performed. ing.

  Furthermore, since a lighting device for lighting a high-pressure discharge lamp for an automobile headlamp needs to perform fine control as described above for a predetermined time immediately after starting, it is electronically equipped with an arithmetic device such as a microcomputer ( For example, see Patent Document 1). This kind of electronic lighting device is driven by a direct current power source such as a battery, and is used for switching a chopper circuit or the like in order to adjust input power or supply power to a high voltage pulse generation circuit. A DC voltage level is made variable using a regulator. Also, if the high pressure discharge lamp is extinguished for some reason while the high pressure discharge lamp is lit, a high voltage pulse is generated by operating a no-load voltage of several hundred volts and a high voltage pulse generation circuit. In order to prevent dielectric breakdown of a device or the like, the operation of the switching regulator is stopped. Once stopped, the state is maintained until the DC power is turned on again or the start signal is input again.

  In addition, a capacitive element such as an electrolytic capacitor is generally equivalent to the input terminal of the switching regulator in order to prevent high frequency noise from leaking to the DC power supply side or to absorb surge coming from the DC power supply side. Connected. Therefore, when the input voltage of the switching regulator is cut off, the input voltage of the switching regulator decreases over a certain period of time due to the action of the capacitive element. When the input voltage falls below the specified voltage, power supply to the high-pressure discharge lamp becomes impossible, and the high-pressure discharge lamp is turned off, or power supply to the high-pressure discharge lamp is detected by detecting a drop in the power supply voltage. Equipped with a function to stop.

  On the other hand, a conventional lighting device for lighting a high-pressure discharge lamp for an automotive headlamp described above operates at a high pressure regardless of the ambient brightness regardless of the ambient brightness. At the time of start-up from a state where the discharge lamp is cooled, it is configured to always be performed.

On the other hand, in the case of a high pressure discharge lamp lighting device for automobile headlamps, a wiring board mounted with a circuit portion mainly composed of a lighting circuit and a control circuit excluding the high pressure discharge lamp is housed in a metal case, and further inside the case Insulating filler is filled almost throughout. As the filler, hard synthetic resin such as silicone, polyurethane and epoxy is used.
JP 2003-151787 A

  However, if the lighting device for lighting a high-pressure discharge lamp for an automobile headlamp has the above-described configuration, if the switching regulator is immediately stopped when the high-pressure discharge lamp goes out for some reason, the turn-off goes off. Regardless of the reason, the light-off state is maintained, which may impair the convenience of the user.

  For example, in an automobile headlamp, when the vibration inherent to the high-pressure discharge lamp is applied from the automobile, a phenomenon may occur in which the discharge goes off. In such a case, there is a possibility that the two right and left high-pressure discharge lamps may be turned off at the same time. In short, functioning to keep the lights off immediately can lead to a very dangerous situation.

  Further, in a high pressure discharge lamp lighting device configured to perform negative feedback control of output power or output current, when the power supply voltage rapidly decreases, the output of the switching regulator may decrease due to the phase delay of the negative feedback. In this case, the high-pressure discharge lamp may turn off due to a decrease in output power. At this time, if the extinguished state is maintained, not only the convenience of the user is impaired, but also the above-mentioned dangerous state can be caused.

  When the power supply of the high-pressure discharge lamp lighting device is shut off, if the high-voltage discharge lamp goes out in the process of discharging the capacitive element connected to the input terminal and the switching regulator stops immediately, the current consumption as the lighting circuit Is extremely reduced, which causes a state in which it takes a very long time for the electric charge of the capacitive element to be discharged. For example, in an automobile headlamp, it is necessary to react and turn on immediately even when the light is turned off for a short time, such as passing. There are cases where it cannot be lit. In other words, even when the power supply is shut off, the high-pressure discharge lamp has been extinguished when the power supply voltage is in the proper range, so the lighting circuit needs to hold the operation stop to suppress the occurrence of dangerous voltage. There is. However, since the power was turned on again, it was necessary to reset it and start the operation again. It is in a state where it is not possible to recognize that the re-input has been performed. Therefore, it is an indispensable operation for restart after short-time extinction to surely discharge the excess charge of the capacitive element.

Next, a problem when the high pressure discharge lamp in the conventional high pressure discharge lamp lighting device is turned off will be described with reference to FIG. FIG. 11 is a waveform diagram showing changes in the power supply voltage when the high pressure discharge lamp in the prior art is extinguished together with changes in the lamp current and the operation signal of the switching regulator. When the power switch is turned off at time t1, FIG. When the terminal voltage _VIN of the capacitive element equivalently connected to the input terminal decreases, the lamp current _IL becomes 0 at time t2 and the high-pressure discharge lamp is extinguished, the switching regulator operates at time t3. The command signal V _SG becomes 0, and the switching regulator stops operating. However, the terminal voltage _VIN of the capacitive element remains to be maintained because the charge remains without being discharged.

  On the other hand, when starting from a state in which the high-pressure discharge lamp is cooled, the lighting device for lighting the high-pressure discharge lamp for an automobile headlamp always supplies twice or more lamp power to the high-pressure discharge lamp during stable lighting. By operating in this manner, a high load is applied to the high-pressure discharge lamp and its lighting circuit, which affects the life of the high-pressure discharge lamp and its lighting circuit. Therefore, it is necessary to enhance the durability of the high-pressure discharge lamp and the lighting circuit, and as a result, the high-pressure discharge lamp and the lighting circuit become expensive. As a result of the study by the present inventor on this point, it has been found that when the surroundings are somewhat bright, it is not necessary to make the rise of the luminous flux extremely rapid as in the dark state.

  On the other hand, in the conventional high pressure discharge lamp lighting device for automobile headlamps, the filler disposed in the case is hard, and the temperature difference of the filler is related to being mounted in an automobile having a large temperature difference. Failure of circuit components may occur due to repeated expansion and contraction. For this reason, the circuit components to be used are limited, and as a result, there is a problem that costs increase. Moreover, filling the filling material almost entirely inside the case in order to withstand humidity and the like increases the cost and increases the stress acting on the circuit components due to the filling material, thereby increasing the probability of component failure. Furthermore, when surface-mounted circuit components that are unlikely to cause component failures are employed, the area of the wiring board increases, and the case, and thus the high-pressure discharge lamp lighting device, also increases in size.

  The present invention relates to a high pressure discharge lamp lighting device capable of discharging a charge of a capacitive element to return a lighting circuit to a reset state when a direct current power supply is shut off, and to immediately relight the high pressure discharge lamp. An object of the present invention is to provide an automotive headlamp using the above.

  In addition, the present invention reduces the load on the high-pressure discharge lamp and the lighting circuit by controlling the degree of input of lamp power larger than the rated power performed immediately after starting according to the ambient brightness, thereby extending the life of these lamps. Another object of the present invention is to provide a high pressure discharge lamp lighting device and an automobile headlamp using the same.

  Furthermore, the present invention provides a high-pressure discharge lamp lighting device and a method for reducing the cost and reducing the probability of failure by improving the housing structure of a circuit component mainly composed of a lighting circuit and a control circuit. Another purpose is to provide automobile headlamps that had been.

    The high-pressure discharge lamp lighting device according to the first aspect of the invention includes a high-pressure discharge lamp; and a lighting device that lights the high-pressure discharge lamp including a switching regulator in which a capacitive element is equivalently connected to the input end and the input end is connected to a DC power source. A high voltage pulse generating circuit for generating a high voltage pulse at the start and applying the high voltage pulse to the high pressure discharge lamp; lighting detection means for detecting start and lighting of the high pressure discharge lamp; and application of the high voltage pulse to the high pressure discharge lamp When the high-voltage discharge lamp is not started even if it continues for a predetermined time, the application of the high-voltage pulse to the high-pressure discharge lamp is stopped and the high-voltage pulse stop means for holding the stop and the operation of the switching regulator are stopped. Switching that stops the operation after discharging the capacitive element charge by continuing the operation of the time switching regulator It is characterized in that it comprises a; and a control circuit including a regulator stop control means.

  In the present invention and each of the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

  <Regarding the high-pressure discharge lamp> The high-pressure discharge lamp that is turned on according to the present invention may basically have any configuration. However, as a high-pressure discharge lamp for an automobile headlamp, a lamp that emits a light beam and white light defined in Japan Electric Bulb Industry Association Standard JEL-215-1998 is used. Hereinafter, the configuration of a high-pressure discharge lamp suitable for an automobile headlamp will be described with respect to the discharge medium, hermetic container, a pair of electrodes, and rated lamp power, which are the main components.

    (Discharge Medium) The discharge medium is composed of a light emitting metal halide, a rare gas, and a buffer substance, and is enclosed in an airtight container described later. As the luminescent metal, sodium (Na) and scandium (Sc) are preferable, and a rare earth metal such as dysprosium (Dy) can be added as desired. By encapsulating these luminescent metals as halides, white light that satisfies the above-mentioned standards can be emitted with high efficiency. As the rare gas, xenon (Xe) is generally 2 atm or more, regardless of the buffer material, preferably 2 to 5 atm in the case of a mercury-containing lamp that encloses mercury as a buffer material, as described later. In the case of a mercury-free lamp in which a second halide to be described later is sealed, it is preferably sealed at a pressure of 6 to 18 atm, preferably 8 to 12 atm. Within the above range, it is possible to easily obtain the luminous intensity of 8000 cd at the representative point on the front surface necessary for the automobile headlamp by accelerating the rise of the light beam up to 4 seconds immediately after lighting. Xenon acts as a starting gas at the time of start-up, acts as a luminescent substance immediately after lighting, and also acts as a buffer gas together with the vapor of mercury constituting the mercury or the second halide during lighting.

  As the buffer substance, mercury may be enclosed, or a metal having a high vapor pressure and low visible light emission, for example, a halide such as zinc (Zn) can be enclosed. In the present specification, in the latter case, a halide as a buffer substance is referred to as a second halide, and a luminescent metal halide is referred to as a first halide. As the metal constituting the second halide, in addition to zinc (Zn), for example, magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), nickel (Ni), manganese ( Mn), aluminum (Al), antimony (Sb), beryllium (Be), rhenium (Re), gallium (Ga), titanium (Ti), zirconium (Zr) and hafnium (Hf) One or more metal halides can also be used.

  As described above, the high-pressure discharge lamp used in the present invention encloses a metal halide instead of the conventional mercury, and therefore, when lighting starts with a lamp power greater than twice the rated lamp power. After a while, the metal halide rapidly evaporates. In this case, if no special control is performed, the light output is remarkably large and increases rapidly.

    (Regarding the airtight container) The airtight container has a discharge space formed therein, and a portion surrounding the discharge space has a relatively large thickness, is fireproof, and is a light-transmitting material such as quartz glass, It consists of translucent ceramics. The discharge space preferably has a substantially cylindrical shape, and the thickness of the central portion in the axial direction is larger than the thickness of both sides thereof.

    (About a pair of electrode) A pair of electrode is sealed so that it may oppose inside the both ends of an airtight container, and the distance between electrodes is set to 6 mm or less, Preferably it is set to 4.25 mm.

    (Regarding Rated Lamp Power) The rated lamp power is generally 60 W or less, and optimally about 35 W.

  <About a lighting circuit> A lighting circuit is a means to light a high pressure discharge lamp, and supplies the electric energy required to maintain a lighting state to a high pressure discharge lamp, controlling as needed. The lighting circuit includes at least a switching regulator. A capacitive element is equivalently connected to the input terminal of the switching regulator.

  Further, the lighting circuit may be configured so that the high-pressure discharge lamp is lit by either AC lighting or DC lighting. In the case of AC lighting, a DC-AC converter for converting the DC output of the switching regulator into AC, for example, an inverter such as a full bridge inverter can be provided. The AC voltage applied to the high-pressure discharge lamp can have a rectangular waveform. In the case of direct current lighting, the direct current output of the switching regulator can be directly supplied to the high pressure discharge lamp. Further, if necessary, for example, by turning on the opposing pair of four switching elements connected to the bridge of the full bridge type inverter and turning off the remaining pair, the required time from the start of the DC-AC converter is reduced. It is also possible to switch to AC lighting by switching to DC operation and then switching the full-bridge inverter to inverter operation.

  By the way, by using a switching regulator in the lighting circuit, it becomes easy to make the DC output variable, so that it is possible to contribute to controlling the voltage applied to the high-pressure discharge lamp as desired. Even if the lighting mode is either AC or DC lighting, the lighting circuit is excellent in terms of ease of control, accuracy, and responsiveness if it is configured electronically. This is preferable. Furthermore, it is preferable to perform constant power control during stable lighting of the high-pressure discharge lamp.

  Next, a capacitive element connected equivalently to the input terminal of the switching regulator will be described. By disposing such a capacitive element, the following operation can be performed. That is, (1) smooth the DC power supply voltage, (2) absorb the current surge coming from the DC power supply side, or (3) leak high frequency noise generated by switching from the switching regulator side to the DC power supply side Absorbs so that there is no such as. The capacitive element can be preferably constituted by an electrolytic capacitor. Note that “capacitance element is equivalently connected to the input terminal” of the switching regulator is not only a mode in which the capacitive element is directly connected to the input terminal, but the capacitive element is connected to the input terminal of the switching regulator. Although it is not connected, it means that an aspect of connection that allows almost the same circuit operation as that directly connected to the input terminal is allowed. For example, this includes a mode in which a capacitive element is connected to the input terminal via a noise prevention circuit.

  Further, the lighting circuit is configured to change the lamp power supplied to the high-pressure discharge lamp according to the control of the switching regulator or the like by the control circuit, and to steadily light the high-pressure discharge lamp by limiting the lamp current. . The current limiting means of the high-pressure discharge lamp must have an appropriate impedance depending on the mode of voltage applied to the high-pressure discharge lamp. However, in the present invention, since a switching regulator is used, an inductor that is a part of the component also takes charge of a current limiting action by switching, so that an apparent current limiting element can be omitted.

  Moreover, it is necessary to consider the frequency at the time of AC lighting so that the high-pressure discharge lamp does not cause an acoustic resonance phenomenon. In the case where the high-pressure discharge lamp is provided with a discharge vessel having a relatively small size as used in an automobile headlamp device, there is no practical problem if the frequency is about 2 kHz or less.

  Furthermore, the lighting circuit can set the no-load output voltage to about 200 to 600V.

  <Regarding High Voltage Pulse Generation Circuit> The high voltage pulse generation circuit may have any circuit configuration as long as it can generate a high voltage pulse at the start and apply it to the high pressure discharge lamp. Therefore, a known circuit configuration is allowed.

  <Regarding the Control Circuit> The control circuit includes at least (1) a lighting detection means for detecting start and lighting of the high pressure discharge lamp, and (2) a high pressure discharge lamp even after a predetermined time of application of a high voltage pulse to the high pressure discharge lamp has elapsed. Stops the application of high voltage pulses to the high pressure discharge lamp when it does not start, and (3) turns off when the high pressure discharge lamp is detected to be off by the lighting detection means. After that, the switching regulator stop control means for stopping the switching regulator after continuing the operation for a predetermined time is included. Hereinafter, the above means will be described.

    (Regarding Lighting Detection Unit) The lighting detection unit may have any configuration as long as it can detect the start and lighting of the high-pressure discharge lamp. For example, a circuit means for detecting a lamp voltage of a high-pressure discharge lamp or a voltage proportional thereto, a circuit means for detecting a lamp current or a current proportional thereto, and a high-pressure discharge lamp based on a detection output by these circuit means The lighting detection means can be constituted by the determination means for determining the starting and lighting of the lamp. Note that an output voltage detection circuit for detecting the output voltage of the switching regulator can be used as the circuit means for detecting a voltage proportional to the lamp voltage. Further, as a circuit means for detecting a current proportional to the lamp current, an output current detection circuit for detecting the output current of the switching regulator can be used. Furthermore, as the determination means, a calculation means such as a microcomputer can be used.

    (About high voltage pulse stop means) The high voltage pulse stop means is a high voltage pulse high pressure discharge lamp when the high voltage discharge lamp does not start even after a predetermined time has elapsed after the start of application of the high voltage pulse to the high pressure discharge lamp. Any configuration may be used as long as the application to can be stopped and the stop can be maintained. For example, a timer that measures the elapsed time from the application of a high voltage pulse to the high-pressure discharge lamp, and an arithmetic means that determines whether a start detection signal obtained from the lighting detection means when the elapsed time is within a predetermined time And high voltage pulse generation operation stop means for stopping the operation of the high voltage pulse generation circuit when the calculation means determines that the start detection signal obtained from the lighting detection means does not arrive when the elapsed time is within the predetermined time. The high voltage pulse stopping means can be configured by the stop holding means for holding the high voltage pulse generation operation stop. For example, when the high voltage pulse generation circuit is configured to obtain the power supply of the high voltage pulse generation circuit from the output of the switching regulator, the input of the high voltage pulse generation circuit is blocked by stopping the operation of the switching regulator. Therefore, it can be configured such that the high voltage pulse generation operation is stopped. The high voltage pulse generation operation stop means can also be configured by inserting a switch in the power supply circuit of the circuit high voltage pulse generation circuit. When the switch is turned off, the application of the high voltage pulse to the high pressure discharge lamp is stopped. can do. Therefore, if the switch is maintained in the off state, the application stop state can be maintained. Common components such as a single microcomputer can be used as the timer and calculation means. In this case, the microcomputer of the lighting detection means can be shared.

    (Regarding the switching regulator stop control means) The switching regulator stop control means is a control means that acts to stop the operation of the switching regulator for a predetermined time when stopping the operation of the switching regulator. Can be configured. During this operation, the capacitive element connected equivalently to the input terminal of the switching regulator is discharged and consumed by the switching regulator. Therefore, the predetermined time may be a level necessary for discharging the capacitive element to a required level. For example, it can be set within a range of several to several tens of milliseconds.

  When stopping the operation of the switching regulator, for example, (1) when the lighting detection means detects that the high-pressure discharge lamp is extinguished, (2) when the DC power supply voltage falls below an appropriate range, (3) DC power supply voltage If the high pressure discharge lamp is extinguished when the lamp is within the proper range, but the arc is extinguished, the DC power supply may be shut off to stop the operation of the switching regulator. it can. Therefore, the high-pressure discharge lamp lighting device can be configured to stop the switching regulator when any one or more of the plurality of cases described above are satisfied.

  In the case of (1), it can be configured to command the stop of the switching regulator in conjunction with the stop of the high voltage pulse. In the case of (2), the voltage of the DC power supply can be grasped by monitoring it. In order to monitor the DC power supply voltage, power supply voltage monitoring means can be provided. Furthermore, in the case of (3), when the lighting detection means detects the extinction of the high-pressure discharge lamp, the DC power supply can be cut off in conjunction with this.

(Regarding other control means of control circuit) In the control circuit, other control means shown below can be appropriately added to the above-described configuration as desired. For example, as a configuration for control suitable for lighting a mercury-free lamp for an automobile headlamp, a control circuit relating to lamp power control for the lighting circuit includes (1) control at startup, and (2) metal halide. It is possible to perform the control when the lamp evaporates rapidly, and (3) the control for calming the rated lamp power and performing the stable lighting. Further, (4) a method for controlling the lamp power and (5) a configuration for high temperature start can be added. Hereinafter, the configuration of these controls will be described.
(1) (Control at start-up) The control at start-up is literally control performed at the start of the high-pressure discharge lamp, that is, at the start of lighting. is there. For this reason, it is preferable that a lamp power having an appropriate value is supplied to the high-pressure discharge lamp in a range of more than twice and less than 3 times the rated lamp power, preferably 2.5 times or less. That is, when the rated lamp power is 35 W, the high pressure discharge lamp should be lit in the range of about 75 to 110 W, preferably 88 W or less. At start-up, discharge due mainly to xenon occurs, and the gas pressure is almost constant or gradually rises. Therefore, in the case of constant current lighting, the lamp power to be applied is substantially constant. In addition, the high-pressure discharge lamp generates a light output of about 50% of the light output at the rated lighting by the discharge of xenon by the control at the start. It should be noted that the time for starting control is generally about 1 to 5 seconds, and preferably about 2 to 4 seconds.
(2) (Regarding the control when the metal halide rapidly evaporates) The control when the metal halide rapidly evaporates is when the light output is stable when the metal halide is rapidly evaporated by reducing the lamp power. It is important that it is not significantly larger than that of the above, and that it does not increase rapidly. However, if the timing of narrowing down the lamp power is too early, and the light output is greatly reduced before the metal halide vaporizes rapidly, the light output will be significantly lower than that at the time of stabilization. Must be done appropriately. In addition, when the metal halide rapidly evaporates, “the light output is not significantly larger than that at the time of stability” refers to a range not exceeding 1.5 times the light output at the time of stability.

  In other words, when good control is to be performed by appropriately performing the narrowing-down timing, it is possible to detect when the metal halide has rapidly evaporated and to narrow down the lamp power to be quickly applied at the time of detection. You can do it. By doing so, even if there is a variation in characteristics among individual high-pressure discharge lamps, it is possible to control so as to obtain a desired light output without reflecting the influence. In the case of this control, the lamp power can be sufficiently reduced to a required level.

On the other hand, in the case of performing good control by appropriately performing the degree of narrowing down, it is necessary to include a timing at which the metal halide rapidly evaporates in consideration of variations in characteristics of individual high-pressure discharge lamps. It is only necessary to set a time width in a narrow range as much as possible in advance, and to attenuate the lamp power input at the start-up with an appropriate attenuation factor carefully considered during the time width. . As an attenuation rate of the lamp power applied during this period, an intermediate value smaller than the attenuation rate in (3) described later is applied. The time width is generally about 0.4 to 4 seconds (about 1.4 to 10 seconds after starting), preferably about 1 to 2 seconds (about 3 to 6 seconds after starting). Then, even if the lamp power is narrowed down slightly before the timing when the metal halide rapidly evaporates, the light output does not increase or decrease excessively beyond the required range, that is, it falls within the allowable range. Will be able to. Further, the “allowable range” of the light output means a range of 50 to 200% of that at the stable time.
(3) (Control for calming down to the rated lamp power) Control to settle down to the rated lamp power is stable lighting for about 1 minute after starting, in other words, control for shifting to the stable light output state. It is. The control of this period can be changed according to the mode of control when the metal halide (2) evaporates rapidly.

In other words, when detecting when the metal halide has rapidly evaporated and narrowing down the lamp power to be quickly applied at the time of detection, the rated lamp power is determined by the continuous decay rate. Can be attenuated. On the other hand, in order to perform control when the metal halide rapidly evaporates with appropriate timing of narrowing down, the attenuation rate is gradually decreased starting from an attenuation rate larger than the attenuation rate in (2). It is good to go. Note that “about 1 minute after starting” means 40 to 70 seconds after starting. In the controls (2) and (3), the lamp power to be input may be attenuated either continuously or stepwise.
(4) (Method for controlling lamp power) The lamp power can be controlled by changing the reference power in the feedback type constant power control system. In the case of the high-pressure discharge lamp of the present invention, the lamp voltage is determined by the vapor pressure of the metal halide, so that constant lamp power control can be performed by dividing the target power by the actual lamp voltage.
(5) (High temperature start) The present invention may have any configuration when the high pressure discharge lamp is started at a high temperature, but preferably the following configuration is adopted. The “high temperature start” means a start at a temperature higher than about room temperature, for example, a temperature close to the stable temperature of the high-pressure discharge lamp, and so-called hot restart corresponds to this.

  In other words, lamp power close to the rated lamp power is supplied at high temperature start. Note that “close to the rated lamp power” is a range from the rated lamp power to less than the maximum power. Further, the discrimination between the low temperature start and the high temperature start can be made according to the temperature of the high-pressure discharge lamp, the turn-off time that is the elapsed time since the turn-off, or the magnitude of the lamp current that flows during the turn-on. Furthermore, the control of the lamp power supplied to the high pressure discharge lamp can be easily performed by changing the voltage applied to the high pressure discharge lamp, for example. Further, if necessary, the supply lamp power can be continuously controlled according to the turn-off time of the high-pressure discharge lamp. Furthermore, how much lamp power is supplied to the high-pressure discharge lamp at the time of high temperature start can be determined in advance by experiment or simulation. Then, the relationship between the low temperature and the high temperature degree and the lamp power time is stored in advance in the memory as table data, and necessary data is read from the memory based on the calculation, and the lighting means is automatically controlled. can do.

  <Regarding the Action of the Present Invention> In the present invention, when the power supply to the high pressure discharge lamp lighting device is turned on, the switching regulator is activated to apply a no-load voltage between the pair of electrodes of the high pressure discharge lamp. Since a high voltage pulse is generated from the pulse generation circuit and applied between the electrodes, the high pressure discharge lamp is started and lit. At this time, the lighting detection means detects the start and lighting of the high pressure discharge lamp. However, when the high-pressure discharge lamp does not start and does not light for some reason, the high-voltage pulse stop means stops the application of the high-voltage pulse to the high-pressure discharge lamp by stopping the operation of the switching regulator, for example, Hold the stop. In this way, when the high-pressure discharge lamp does not start and does not light, the application of the high voltage pulse to the high-pressure discharge lamp is maintained, so that safety can be achieved.

  Next, for example, (1) when the lighting detection means detects that the high-pressure discharge lamp is extinguished, (2) when the DC power supply voltage falls below the proper range, or (3) the DC power supply voltage is within the proper range. However, when the high-pressure discharge lamp is extinguished when it is close to the lower limit, the DC power supply can be shut off to stop the operation of the switching regulator. The operation is stopped after continuing for a predetermined time. By the operation of the switching regulator for a predetermined time before the stop, the charge of the capacitive element equivalently connected to the input terminal of the switching regulator is consumed via the switching regulator. Discharge to the required level. As a result, the high pressure discharge lamp lighting device can return to the reset state. For this reason, according to the high pressure discharge lamp lighting device of the present invention, even if the DC power supply is immediately turned on again, it can be quickly detected and the high pressure discharge lamp can be started and lit.

  Further, according to the present invention, as can be understood from the above operation, since the charge of the capacitive element is discharged by the above circuit operation, a discharge circuit including a resistance element for extracting unnecessary charge is added. Since there is no need, it is possible to prevent a reduction in circuit efficiency, and to obtain a high-pressure discharge lamp lighting device that is small, low-cost, and highly reliable.

<Other Configurations of the Present Invention> Although it is not an essential component of the present invention, by adding the following configurations, performance is improved as a high pressure discharge lamp lighting device for an automobile headlamp, or a function is added. Or
(1) (Control according to ambient brightness) “Control according to ambient brightness” refers to controlling the degree of lamp power input that is greater than the rated power immediately after startup according to ambient brightness. To do. A high-pressure discharge lamp lighting device for performing such control is configured as follows.

  That is, the high-pressure discharge lamp lighting device has a high-pressure discharge lamp, a lighting circuit for energizing the high-pressure discharge lamp, and a high-pressure discharge lamp having a first lamp power that is at least twice the rated lamp power when the surroundings are dark. And a control circuit that controls the lighting means to start by supplying a second lamp power smaller than the first lamp power when the surroundings are bright.

  In order to detect ambient brightness, it is preferable to provide brightness detection means or a clock (timer). The brightness detection means directly detects the actual brightness of the surroundings. On the other hand, a clock (timer) indirectly detects a change in brightness over time. The brightness detection means is suitable for detecting brightness in a plurality of stages or continuously. The degree of lamp power input can be changed in a plurality of steps or continuously according to the brightness detection value. However, it can be configured to control in two stages as desired. On the other hand, a clock (timer) is suitable for detecting the brightness in two steps and changing the degree of lamp power input in two steps according to the detected value.

Thus, by adopting the above-described control according to the ambient brightness described above, it is not necessary to always supply a large amount of lamp power when starting the high-pressure discharge lamp, so the length of the high-pressure discharge lamp and its lighting device can be reduced. Life expectancy can be realized.
(2) (About the mounting structure of a lighting circuit and a control circuit) The mounting structure of a lighting circuit and a control circuit is comprised as follows.

  That is, the high-pressure discharge lamp lighting device includes a high-pressure discharge lamp; a lighting circuit that energizes the high-pressure discharge lamp; and a control circuit that controls the lighting circuit. The lighting circuit and the control circuit include a wiring board and a wiring. Circuit components mounted on the board, input connectors and output connectors mounted on the wiring board, a case for storing the wiring boards, circuit components, input connectors and output connectors, and wiring filled in the case The entire board is embedded, and a filling material made of a synthetic resin filled to a depth at which only the base end portion on the wiring board side of the input connector and the output connector is embedded is provided.

  There may be a single wiring board or a plurality of wiring boards. However, the structure can be simplified by using a single wiring board. The circuit component may include a high voltage pulse generation circuit. When a lead component is used as a circuit component, by causing a spacer to be interposed between the component and the lead, it is possible to avoid a failure caused by a flexible filler having a hardness of 25 or less as will be described later. The case is preferably made of metal, but can be made of a hard synthetic resin if desired. The entire wiring board is embedded in the filling material, but the filling depth is embedded only in the base end of the input connector and output connector on the wiring board side, and therefore the wiring in the input connector and output connector Portions other than the base end on the substrate side are exposed to the outside from the filler. The filler is preferably made of a synthetic resin having flexibility. In this case, the filler may have a hardness of 25 or less, preferably 5 or more. For example, a silicone resin or a urethane resin having a hardness of 25 or less can be used. The silicone resin is preferably a gel.

  By adopting the mounting structure of the lighting circuit and the control circuit described above, the stress on the circuit components is reduced even when used in an environment where the temperature changes severely. As a result, the amount of filler used is reduced, and it is not necessary to use circuit components having a structure that is unlikely to break down. Therefore, a high-pressure discharge lamp lighting device can be obtained that reduces costs.

    An automobile headlamp device according to a second aspect of the invention comprises an automobile headlamp device body; and the high-pressure discharge lamp lighting device according to claim 1 disposed in the vehicle headlight device body. It is characterized by.

  “Automobile headlamp device main body” refers to the remaining part of the vehicle headlamp device excluding the high-pressure discharge lamp lighting device. Among the high-pressure discharge lamp lighting devices, the high-pressure discharge lamp is mounted in the automobile headlight device body, but the circuit portion mainly composed of the lighting circuit and the control circuit is attached to the back side of the vehicle headlight device body. Alternatively, it may be disposed at a position away from the automobile headlamp main body.

  Thus, according to the present invention, the high pressure discharge lamp lighting device according to claim 1 is provided, so that when the switching regulator is turned off for some reason during lighting, the switching regulator continuously operates for a predetermined time and then stops operating. Thus, the electric charge of the capacitive element connected to the input terminal is discharged, so that an automobile headlamp device that can be instantly restarted by turning on the power again is obtained.

    According to the first aspect of the present invention, the operation of the switching regulator is continued for a predetermined time and then stopped, so that the charge of the capacitive element is discharged and the lighting circuit can be returned to the reset state. Even if the DC power supply is turned on, the high-pressure discharge lamp can be turned on again, and there is no need to add a discharge circuit including a resistance element for extracting the charge remaining in the capacitive element, thus reducing the efficiency. Therefore, it is possible to provide a high-pressure discharge lamp lighting device that is small, low-cost, and highly reliable.

    According to invention of Claim 2, the motor vehicle headlamp apparatus which has the effect of Claim 1 can be provided.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

    1 to 4 show a first embodiment for implementing a high pressure discharge lamp lighting device of the present invention, FIG. 1 is a block circuit diagram, FIG. 2 is a front view of the high pressure discharge lamp, and FIG. 4 is a conceptual cross-sectional view showing a mounting state of circuit parts such as a control circuit, and FIG. 4 is a graph showing voltage and current waveforms of each part. This embodiment is a high-pressure discharge lamp lighting device used for an automobile headlamp device. In FIG. 1, DC is a DC power supply, SW1 is a power switch, C1 is an electrolytic capacitor as a capacitive element, OC is a lighting circuit, CC is a control circuit, IG is a high voltage generation circuit, and HPL is a high pressure discharge lamp. Hereinafter, each component will be described.

  The DC power source DC is a battery having a DC voltage of 12V.

  The power switch SW1 is connected in series between the DC power source DC and a lighting means OC described later, and controls the blinking of the high-pressure discharge lamp HDL.

  The electrolytic capacitor C1 is connected in parallel with the DC power source DC via the power switch SW.

  <Lighting Circuit OC> The lighting circuit OC is composed of a switching regulator DC / DC and an inverter DC / AC.

    (Switching Regulator DC / DC) The switching regulator DC / DC is composed mainly of an output transformer T, switching means Q1, a gate drive signal generation circuit GDCS, a diode D1, and a smoothing capacitor C2. The primary winding wp of the output transformer T and the switching means Q1 are connected in series between both ends of the electrolytic capacitor C1. The switching means Q1 is composed of a MOSFET. The resistor R1 inserted in series with the switching means Q1 is for switching current detection. The gate drive signal generation circuit GDGS generates a gate drive signal and applies it between the gate and source of the switching means Q1. Then, the gate drive signal can be PWM-controlled according to a control signal input from the outside.

  A diode D1 and a smoothing capacitor C2 are connected in series across the secondary winding ws of the output transformer T. Further, the output transformer T is provided with a tertiary winding wt as an extension of the secondary winding ws, and is configured as described later together with the secondary winding ws, whereby a high voltage pulse generating circuit IG Supply power.

  In this way, a boosted, controlled and smoothed DC output voltage of the switching regulator DC / DC is obtained across the smoothing capacitor C2.

    (Inverter DC / AC) The inverter DC / AC is a full-bridge inverter, and includes four switching means Q2 to Q5, gate drive signal generation circuits GDC1 to GDC4, a rectangular wave oscillation circuit OSC, a switching means SW2, an inverting circuit N, and It consists of a non-inverting circuit Y. The four switching means Q2 to Q5 are each composed of a MOSFET and are connected so as to constitute a bridge circuit. The input terminal of the bridge circuit is connected between the DC output terminals of the switching regulator DC / DC. The gate drive signal generation circuits GDC1 to GDC4 form gate drive signals in synchronization with the output signal or DC potential of the rectangular wave oscillation circuit OSC to be described later via the inverting circuit N or the non-inverting circuit Y, respectively, and corresponding switching means A gate drive signal is supplied between the gate and source of Q2 to Q5 to turn them on. The rectangular wave oscillation circuit OSC oscillates a rectangular wave output signal having a frequency of 100 Hz to 2 kHz. The switching means SW2 selectively connects the output signal of the rectangular wave oscillation circuit OSC and the direct current potential to the gate drive signal generation circuits GDC1 and GDC3 via the inverting circuit N, and the gate drive signal generation circuits GDC2 and GDC4. Are connected via a non-inverting circuit Y.

  Then, the output of the rectangular wave oscillation circuit OSC is applied to the gate drive signal generation circuits GDC1 to GDC4 via the switching means SW2 and the inverting circuit N or the non-inverting circuit Y, whereby Q2 of the four switching means and Q5 and Q3 and Q4 are alternately switched to perform an inverter operation. As a result, an AC output voltage is obtained from the output terminal of the bridge circuit. Further, when a DC potential is applied to the gate drive signal generating circuits GDC1 to GDC4 via the switching means SW2 and the inverting circuit N or the non-inverting circuit Y, Q2 and Q5 of the four switching means are turned on, and Q3 and Since Q4 is turned off, a DC output voltage can be obtained from the output terminal of the bridge circuit. In summary, the lighting circuit OC can perform direct current lighting or alternating current lighting of a high pressure discharge lamp HPL to be described later by selecting one of the direct current output and the alternating current output.

  <High Voltage Pulse Generation Circuit IG> The high voltage pulse generation circuit IG is interposed between the lighting circuit OC and the high pressure discharge lamp HPL, and applies a high voltage pulse to the high pressure discharge lamp HPL when starting. The high voltage pulse generation circuit IG is configured to be supplied with power from the switching regulator DC / DC. That is, a series circuit of a diode D2, a resistor R6 and a capacitor C3 is connected between the high voltage side terminal of the tertiary winding wt of the output transformer T of the switching regulator DC / DC and the low voltage side terminal of the secondary winding ws. The capacitor C3 is configured to be operated by a DC voltage obtained between both ends thereof. A secondary winding of a pulse transformer that outputs a high-voltage pulse (not shown) is inserted in series between the high-pressure discharge lamp HPL and the switching regulator DC / DC.

  <Control Circuit CC> The control circuit CC includes a lighting detection means LD, a high voltage pulse stop means PS, a switching regulator stop control means SS, and other control means such as a lamp voltage detection means LVD, a lamp current detection means LCD, and a lighting time timer. It includes an OT, a turn-off time timer LOT, a target lamp power setting circuit TLP, an actual lamp power detection means RLPD, and a lamp power adjustment means LPR. Hereinafter, these control means will be described.

    (Lighting detection means LD) The lighting detection means LD responds to a detection output of a lamp voltage detection means LVD described later. That is, when the discharge starts, the high-pressure discharge lamp HPL has a lamp voltage that is clearly lower than the no-load voltage that appears between the electrodes. Therefore, the lighting detection means LD monitors the detection output of the lamp voltage detection means section LVD, and can detect that the high-pressure discharge lamp HPL has been started and turned on, for example, when the detection output suddenly decreases.

    (High Voltage Pulse Stop Unit PS) The high voltage pulse stop unit PS includes a switch SW2 connected in series to the power supply circuit of the high voltage pulse generation circuit IG, a timer, and a calculation unit TC. Then, when the switch SW2 is turned off, the high voltage pulse stopping means PS stops its operation, so that the application of the high voltage pulse to the high pressure discharge lamp HPL is stopped. The timer and calculation means TC starts timing based on the extinction detection signal from the lighting detection means LD, and turns off the switch SW2 when the lighting detection signal does not arrive from the lighting detection means LD by the time when a predetermined time has elapsed. At the same time, the state is maintained.

    (Switching regulator stop control means SS) The switching regulator stop control means SS comprises a delay circuit, and the timer of the high voltage pulse stop means PS and the arithmetic means TC start timing based on the extinction detection signal from the lighting detection means LD. The switching regulator DC / DC is operated when it is determined that the lighting detection signal does not arrive from the lighting detection means LD before the predetermined time elapses, and the switching regulator DC / DC is stopped after the operation is continued for a predetermined time. The switching regulator stop control means SS is provided with a voltage drop detection circuit VDD. The voltage drop detection circuit VDD monitors the voltage of the DC power supply DC, operates the switching regulator stop control means SS even when the DC power supply voltage drops below a predetermined value, and continues the switching regulator DC / DC for a predetermined time. Stop after.

    (Ramp voltage detection means LVD) The lamp voltage detection means LVD is composed of a series circuit of a pair of resistors R2 and R3 connected between both ends of a smoothing capacitor C2 from which a DC output voltage of the switching regulator DC / DC is obtained. A divided voltage proportional to the lamp voltage of the high-pressure discharge lamp HPL is obtained at both ends of the resistor R3.

    (Regarding the lamp current detection means LCD) The lamp current detection means LCD is composed of a resistor R4 inserted in series between the DC output of the switching regulator DC / DC and the DC input terminal of the inverter DC / AC. The voltage drop is proportional to the lamp current.

    (On Lighting Time Timer OT) The lighting time timer OT obtains the output of the lighting detection means LD and starts a timer operation to measure the lighting time of the high-pressure discharge lamp HPL. Then, the timer output is sent to a target lamp power setting circuit TLP and switching means SW2, which will be described later.

    (About the extinguishing time timer LOT) The extinguishing time timer LOT starts the timer operation when the output of the lighting detecting means LD is extinguished, and measures the extinguishing time of the high-pressure discharge lamp HPL. Then, the timer output is sent to the lighting time timer OT, and the initial value of the lighting time timer OT is changed according to the turn-off time.

    (Regarding Target Lamp Power Setting Circuit TLP) The target lamp power setting circuit TLP includes a target lamp power memory LPM, a division circuit DVC, and an integration circuit ICC. The target lamp power memory LPM stores a target lamp power to be input to the high-pressure discharge lamp HPL with respect to the lighting time. And the value of the target lamp electric power according to lighting time is sent to the lamp electric power adjustment means LPR mentioned later. The target lamp power is set separately for the first to third time zones. That is, 0.0 to 3.4 seconds is the first time zone, and the first target lamp power at that time is 85 W, and the attenuation rate is 0.00 (W / second). Similarly, 3.4 to 5.0 seconds is the second time zone, and the second target lamp power at that time starts constant attenuation at 853 W with a decay rate of 3.13 (W / sec) and reaches 80 W. Further, 5.0 to 48 seconds is the third time zone, and the third target lamp power at that time starts to attenuate at the attenuation rate 9 (W / second) from 80 W first, and then the attenuation rate decreases sequentially. Is set to 35 W in 48 seconds and an attenuation factor of 0.00, that is, stable lighting.

  The division circuit DVC divides the target lamp power sent from the target lamp power memory LPM by the lamp voltage obtained from the lamp voltage detection unit LVD, and converts it into a corresponding target lamp current. The integrating circuit ICC includes a resistor R5 and a capacitor C3, and obtains a stable target lamp current.

    (Regarding actual lamp power detection means RLPD) The actual lamp power detection means RLPD is constituted by a lamp current detection means LCD. That is, the actual lamp current corresponding to the actual lamp power is detected.

    (Lamp Power Adjusting Unit LPR) The lamp power adjusting unit LPR includes a first differential amplifier circuit DFA1 and a second operational amplifier circuit DFA2. The first differential amplifier circuit DFA1 is composed of an operational amplifier, and inputs the target lamp current, that is, the target lamp power, to the inverting input terminal thereof, and inputs the actual lamp current, that is, the actual lamp power, to the non-inverting input terminal thereof. The difference between the target lamp current (target lamp power) and the actual lamp current (actual lamp power) is output to the output terminal. The output terminal is connected to the control input terminal of the gate drive signal generation circuit GDCS of the switching regulator DC / DC. The second operational amplifier circuit DFA2 is connected in parallel to the first differential amplifier circuit DFA1, the reference voltage source E is connected to the inverting input terminal thereof, and the ramp voltage detector LVD is connected to the non-inverting input terminal. The output terminal is connected. And it acts as a negative feedback control circuit of no-load voltage, and maintains the output voltage before starting the high-pressure discharge lamp HPL constant.

  <Regarding the High Pressure Discharge Lamp HPL> The high pressure discharge lamp HPL has a structure shown in FIG. That is, the high-pressure discharge lamp HPL includes the arc tube IT, the insulating tube T, the outer tube OT, and the base B.

  The arc tube IT includes an airtight container 1, a pair of electrodes 1b and 1b, a sealing metal foil 2, a pair of external lead wires 3A and 3B, and a discharge medium. The airtight container 1 includes an enclosing portion 1a and a pair of sealing portions 1a1. The surrounding portion 1a is formed in a hollow spindle shape, and is integrally provided with a pair of elongated sealing portions 1a1 at both ends thereof, and an elongated substantially cylindrical discharge space 1c is formed therein. The internal volume of the discharge space 1c is 0.05 cc or less.

  The electrode 1b is made of a doped tungsten wire, has the same diameter in the axial portion over the distal end portion, the intermediate portion, and the proximal end portion in the axial direction, and a part of the distal end portion and the intermediate portion is exposed in the discharge space 1c. ing. Further, the base end portion of the electrode 1b is welded to a sealing metal foil 2 to be described later embedded in the sealing portion 1a1, and the intermediate portion is loosely supported by the sealing portion 1a1, whereby the predetermined portion of the airtight container 1 is set. Arranged in position. In the drawing, after the left sealing portion 1a1 is formed, the sealing tube 1a2 is integrally cut from the lower portion of the sealing portion 1a1 without being cut, and extends into the base B.

  The sealing metal foil 2 is made of molybdenum foil, and is hermetically embedded in the sealing portion 1 a 1 of the hermetic container 1.

  The discharge medium is composed of first and second halides and gas and is essentially free of mercury. The first halide contains at least one metal selected from sodium (Na), scandium (Sc), and a rare earth metal. The second halide includes a halide containing at least one metal having a relatively high vapor pressure and hardly emitting light in the visible region as compared to the first halide. The gas is composed of a noble gas.

  The distal ends of the pair of external lead wires 3A and 3B are welded to the other end of the sealing metal foil 2 in the sealing portions 1a1 at both ends of the airtight container 1, and the proximal end sides are led out to the outside. In the drawing, the external lead wire 3A led to the right from the discharge vessel IT is folded back along an outer tube OT described later, introduced into a later-described base B, and disposed on the outer peripheral surface of the base B. It is connected to one base terminal t1 that forms a ring shape. The external lead wire 3B led out from the discharge vessel IT to the left extends along the tube axis and is led out into the base B so as to form a pin-like terminal disposed in the center (not shown). Connected to.

  The outer tube OT has a UV-cutting performance, accommodates the discharge vessel IT therein, and the diameter-reduced portions 4 at both ends (only one end on the right is shown in the figure) of the discharge vessel IT. Glass is welded to the sealing portion 1a1. However, the inside of the outer tube OT is not airtight but communicates with the outside air.

  The insulating tube T is made of a ceramic tube and covers the external lead wire 3A.

  The base B is standardized for automobile headlamps, supports the discharge vessel IT and the outer tube OT along the central axis, and is detachable from the back of the automobile headlamp. Installed. In addition, a ring-shaped base terminal t2 having a ring shape disposed on the outer peripheral surface of the cylindrical base body B1 made of an insulator so that it can be connected to the lamp socket LS on the power source side when mounted, and a cylindrical part base It comprises a pin terminal (not shown) on the high-voltage side that forms a pin shape and projects in the tube axis direction at the center of the recess B11 that is open at one end and is formed at the lower end of the main body B1.

Next, the circuit operation in this embodiment will be described with reference to FIG. In the figure, V _DC is a DC power supply voltage, _IL is a lamp current, V _B is a ballast voltage, V _INV is an inverter output voltage, and V _SG is an operation command signal voltage.

That is, in the period T1, when the direct-current power supply voltage _VDC greatly decreases and the high-pressure discharge lamp HPL cannot maintain lighting, since the current consumption is large in the state where the high-voltage discharge lamp HPL is still lit, the direct-current power supply voltage _VDC decreases. Become prominent. Finally, the arc of the high pressure discharge lamp HPL disappears and turns off. Incidentally, when the high pressure discharge lamp HPL is turned off, along with the lamp current I _L decreases, the ballast voltage V _B discharge becomes unstable varies its influence.

When the light is turned off, no load is applied in the period T2, and the switching regulator DC / DC continues to operate while the DC power supply voltage V _DC decreases gradually. Note that the polarity of the ballast voltage V _B is reversed at the moment of extinguishing. In addition, the output voltage _VINV of the inverter DC / AC rises rapidly because it is no load. During this period, the electric charge of the electrolytic capacitor C1, which is a capacitive element, is discharged and consumed via the switching regulator DC / DC, so that the DC power supply voltage V _DC drops to a required level.

  In the period T3, the operation command signal voltage disappears, so that the switching regulator DC / DC ends the operation for a predetermined time and enters a reset state.

  Next, the mounting structure of the circuit portion of the high pressure discharge lamp lighting device will be described with reference to FIG. In the figure, 5 is a wiring board, 6 is an input connector, 7 is an output connector, 8 is a case, and 9 is a filler. The wiring board 5 has circuit components, an input connector 6 and an output connector 7 mounted at predetermined positions, and is housed in a case 8. The circuit components are not shown.

  Case 8 is made of metal material. The inside of the case 8 is filled with a filler 9. The filling material 9 is embedded in the entire wiring board 5, but is filled only in the vicinity of the bottom inside the case 8 so that only the base end portions of the input connector 6 and the output connector 7 are embedded. ing. Moreover, the filler 9 is comprised with the gel-like silicone resin whose hardness is 25 or less.

  Hereinafter, other embodiments for carrying out the present invention will be described with reference to FIGS. In addition, in each figure, the same code | symbol is attached | subjected about the same part as FIG.

    FIG. 5 is a block circuit showing a second embodiment for carrying out the high-pressure discharge lamp lighting device of the present invention. In this embodiment, the ambient brightness is detected, and the degree of turning on the lamp power larger than the rated power performed immediately after starting is controlled based on the detected value.

  That is, in the figure, the control circuit CC includes a main control unit MC, a timer TM1, and brightness detection means BD. Main controller MC and timer TM1 have the same configuration as that of control circuit CC in the first embodiment. The timer TM1 is provided separately from the main control unit MC, and measures the passage of time after startup. The main control unit MC changes the input power immediately after starting according to the output of the timer TM1.

  The brightness detection means BD detects ambient brightness and controls and inputs the detection output to the main controller MC. The main control unit MC adjusts the electric power supplied to the high-pressure discharge lamp HPL based on the detection output of the brightness detection means BD.

    FIG. 6 is a block circuit showing a third embodiment for implementing the high pressure discharge lamp lighting device of the present invention. This embodiment is different from the second embodiment shown in FIG. 5 in that the function of the timer TM1 in the second embodiment is built in a main control unit MC ′ having a computing means such as a microcomputer.

    FIG. 7 is a block circuit showing a fourth mode for carrying out the high-pressure discharge lamp lighting device of the present invention. This embodiment differs from the second embodiment shown in FIG. 5 in that the brightness detection means BD is replaced with a timer TM2. That is, in this embodiment, the brightness is indirectly detected by the timer TM2.

    FIG. 8 is a block circuit showing a fifth mode for carrying out the high-pressure discharge lamp lighting device of the present invention. The present embodiment is different from the fourth embodiment shown in FIG. 7 in that the function of the timer TM1 is built in a main control unit MC ′ having a computing means such as a microcomputer.

    FIG. 9 is a block circuit showing a sixth mode for carrying out the high pressure discharge lamp lighting device of the present invention. This embodiment is different from the fifth embodiment shown in FIG. 8 in that the function of the timer TM2 is built in the main controller MC ″.

    FIG. 10 is a schematic view showing an embodiment for carrying out the automobile headlamp apparatus of the present invention. The vehicle headlamp includes a vehicle headlamp body 21 and a high-pressure discharge lamp lighting device 22 as a lighting device body.

  The automobile headlamp main body 21 includes a headlamp case 21a, a front transmission panel 21b, a reflector 21c, and the like. The headlamp case 21a has a front transmission panel 21b attached to the front opening thereof, and a reflector 21c disposed therein. The front lens 21b has a shape combined with the outer surface of the automobile, and includes necessary optical means such as a prism. The reflector 21c is disposed so as to enclose the high-pressure discharge lamp HPDL, and is configured to obtain a required light distribution characteristic in cooperation with the optical means.

  The high pressure discharge lamp lighting device 22 includes a high pressure discharge lamp 22a, a high voltage pulse generation circuit 22b with a lamp socket, a lighting circuit 22c, and the like. The high-pressure discharge lamp 22a is the same as that shown in FIG. The high voltage pulse generation circuit 22b with a lamp socket is disposed at the back of the reflector 21c, and a high pressure discharge lamp 22a is mounted on the lamp socket, and the high voltage pulse generation circuit 22b is internally shown in FIG. 2, FIG. 3, FIG. It contains an incandescent pulse generating circuit with a high voltage pulse transformer shown. The lighting circuit 22c is housed in a metal case and disposed on the back surface of the headlamp case 21a. The internal configuration of the lighting circuit 22c is the same as that in FIG. 1 or FIG. The cable 23 led out from the lighting circuit 22c is connected to an automobile battery, a headlight operation switch, an alarm device, a display device, and the like.

The block circuit diagram which shows the 1st form for implementing the high pressure discharge lamp lighting device of this invention Similarly, front view of high-pressure discharge lamp Similarly, a conceptual cross-sectional view showing mounting states of circuit parts such as a lighting circuit and a control circuit Similarly, a graph showing the voltage and current waveforms of each part Block circuit showing a second embodiment for implementing the high pressure discharge lamp lighting device of the present invention Block circuit showing a third embodiment for implementing the high pressure discharge lamp lighting device of the present invention Block circuit showing a fourth embodiment for implementing the high pressure discharge lamp lighting device of the present invention Block circuit showing a fifth mode for carrying out the high-pressure discharge lamp lighting device of the present invention Block circuit showing a sixth embodiment for implementing the high pressure discharge lamp lighting device of the present invention The schematic diagram which shows one form for implementing the motor vehicle headlamp apparatus of this invention Waveform diagram showing changes in power supply voltage when the high pressure discharge lamp in the prior art is turned off, together with changes in lamp current and switching regulator operation signal

Explanation of symbols

      C1 ... electrolytic capacitor, CC ... control circuit, DC / AC ... inverter, DC / DC ... switching regulator, HPL ... high pressure discharge lamp, IG ... igniter, LD ... lighting detection means, OC ... lighting circuit, PS ... high voltage pulse stop Means, SS: Switching regulator stop control means, SW1: Power switch, T: Output transformer

Claims (2)

A high-pressure discharge lamp;
A lighting circuit for lighting a high-pressure discharge lamp including a switching regulator having a capacitive element equivalently connected to the input end and connecting the input end to a DC power supply;
A high voltage pulse generating circuit for generating a high voltage pulse at the start and applying it to the high pressure discharge lamp;
Lighting detection means for detecting the start and lighting of the high-pressure discharge lamp, and applying the high-voltage pulse to the high-pressure discharge lamp when the high-voltage discharge lamp does not start even if the application of the high-voltage pulse to the high-pressure discharge lamp is continued for a predetermined time High voltage pulse stop means for stopping and holding the stop, and switching regulator stop control for stopping the operation after discharging the charge of the capacitive element by continuing the operation of the switching regulator for a predetermined time when stopping the operation of the switching regulator A control circuit including means;
A high-pressure discharge lamp lighting device comprising: An automotive headlamp device body;
The high-pressure discharge lamp lighting device according to claim 1, which is disposed in a vehicle headlamp device body;
A vehicle headlamp device comprising:

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