JP2001196192A - High frequency power equipment, discharge lamp lighting equipment and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high frequency power equipment impressing high voltage repetitiously to a load at the time of a starting of a high frequency inverter and a discharge lamp lighting equipment and a lighting system using it. SOLUTION: An operation frequency sweep control means by which a sweep of the operation frequency is carried out within predetermined limit at the time of the starting of the high-frequency inverter HFI is furnished, while including at least a 1st and 2nd reactance XL and XC which constitute a load resonance circuit LRC, and supplying a high frequency to a load, for example the load circuit which is connected in parallel with a high pressure discharge lamp. While constituting the high frequency inverter with the half bridge type inverter, the drive circuit of the switching means is constituted with the synchronous winding which is magnetically coupled to the inductive reactance of the load circuit and the switching resonance circuit which is resonated by being impressed with the voltage induced in the synchronous winding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency power supply device having a high-frequency inverter, a discharge lamp lighting device and a lighting device using the same.

[0002]

2. Description of the Related Art When starting and lighting a high-pressure discharge lamp having a lamp power of 50 W or less, a high-frequency discharge lamp provided with a resonance circuit is started and lit without using an igniter. The present inventors have found that it is possible to reduce the size of the discharge lamp lighting device. As a result, a compact bulb-type high-pressure discharge lamp in which a high-pressure discharge lamp and a lighting device that is a power source for lighting the lamp are integrated has been made possible.

[0003]

However, irrespective of whether the high-pressure discharge lamp and its lighting device are integrated, the discharge lamp lighting device for lighting the high-pressure discharge lamp is small in size and compared with the fluorescent lamp. There is a demand for the development of a power supply device that can obtain a high starting voltage.

An object of the present invention is to provide a high-frequency power supply device which repeatedly generates a high voltage at the time of starting a high-frequency inverter and applies it to a load, a discharge lamp lighting device and a lighting device using the same.

Further, the present invention provides a high-frequency power supply device suitable for lighting a small high-pressure discharge lamp having a lamp power of 50 W or less provided with a translucent ceramics discharge vessel, a discharge lamp lighting device and a lighting device using the same. Another purpose is to provide

[0006]

According to a first aspect of the present invention, there is provided a high-frequency power supply device including at least a first reactance and a second reactance constituting a load resonance circuit, wherein a load is connected in parallel to one of the reactances. A DC power supply; a high-frequency inverter that includes switching means and converts DC input from the DC power supply to a high frequency and supplies the high-frequency inverter to the load circuit; Operating frequency sweep control means for sweeping within the apparatus.

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

<Regarding Load Circuit> The load circuit is provided with a load connected thereto, and functions to receive a supply of high-frequency power from a high-frequency inverter to energize and operate the load. Therefore, the load circuit includes at least a first reactance and a second reactance, and the first and second reactances are connected to a resonance circuit (hereinafter, referred to as a resonance circuit).
It is called “load resonance circuit”. ). Therefore, the first reactance and the second reactance have different electrical properties from each other. That is, if the first reactance is an inductive reactance, a capacitive reactance is selected as the second reactance. It is assumed that this mutual relationship is similarly selected even if the electrical properties of the first and second reactances are interchanged. The inductive reactance can be configured by using an inductor such as a choke coil or a leakage transformer. Then, by using a saturable inductance as the inductive reactance, the resonance frequency of the load resonance circuit changes between when the inductance is saturated and when it is not saturated. Even if it is constant, the degree of resonance of the power supply of the load resonance circuit with respect to the high frequency changes. A high voltage can be easily generated by utilizing the change in the degree of resonance. On the other hand, the capacitive reactance can be configured by using a capacitor. Further, each of the first and second reactances can be configured with one or more reactance elements.

Next, the load may be applied with a high voltage at least when the high-frequency inverter is started.
Alternatively, any type may be used as long as it has a property that requires application of a high voltage, but a discharge lamp is preferably used. The load is
It is connected in parallel to the first or second reactance of the load circuit. Therefore, the load connects the high frequency inverter via the second reactance or the first reactance in series. If the load is a discharge lamp, the second or first reactance connected in series with the load acts as a current limiting impedance. And the load
A voltage appearing across the first or second reactance is applied.

[0010] In addition to the first and second reactances and the load, additional circuits and circuit components can be connected to the load circuit as required. For example, it is permissible to connect a filament heating circuit or the like when the load is a discharge lamp having a filament electrode, or to connect an insulating transformer or a DC cut capacitor that electrically insulates between the load and the high-frequency inverter. When a DC cut capacitor is used, it is allowed to select the capacitance so that the capacitor forms a substantial part of the first or second reactance.

<Regarding DC Power Supply> The DC power supply may be any of a rectified DC power supply obtained by rectifying AC and a battery power supply. In the case of a rectified DC power supply, it is desirable to have a smoothing means. As the smoothing means, a configuration in which a smoothing capacitor is connected between the DC output terminals of the rectifier circuit, an active filter such as a chopper circuit, or a composite active filter that operates using switching means of a high-frequency inverter described later, for example, a partial smoothing means A circuit can be used.

<High Frequency Inverter> A high frequency inverter is power conversion means for converting DC to high frequency AC, and has a DC input terminal connected to a DC power supply and a high frequency output terminal connected to a load circuit. When a high-frequency inverter is configured by a stationary inverter, a high-frequency AC is obtained by performing high-frequency switching of DC using switching means.

The high frequency inverter is controlled by an operating frequency sweep control means described later so that its operating frequency can be controlled. Therefore, the high-frequency inverter according to the present invention may have any configuration as long as the operation frequency is controllable. For example, a high-frequency inverter such as a half-bridge type inverter, a full-bridge type inverter, a parallel-type inverter, and a single-type inverter can be used alone, or a high-frequency inverter can be used in combination with a switching regulator as an active filter. Also, by using the switching means of the high-frequency inverter as the switching means of the active filter, a so-called composite high-frequency inverter having an active filter can also be used. In the present invention, “high frequency” refers to a frequency of 10 kHz or more.

Further, the high-frequency inverter may be either self-excited or separately excited. In the case of self-excited oscillation, oscillation is performed by positively feeding back the output of the high-frequency inverter from an appropriate position on the circuit. Therefore, in order to regulate the operating frequency to a constant value, a resonance circuit (hereinafter referred to as a “switching resonance circuit”) is used. Is preferably provided.
Therefore, in the case of self-excited oscillation, the operating frequency of the high-frequency inverter can be easily controlled by changing the resonance frequency of the switching resonance circuit. On the other hand, in the case of separately excited oscillation, the oscillation frequency of the oscillation circuit is changed because an independent oscillation circuit is provided and the oscillation output regulates switching indirectly or directly via the drive signal generation circuit. By doing so, the operating frequency can be easily controlled. Furthermore, the high-frequency inverter can control the on-duty and the like as needed in addition to controlling the operating frequency. Or,
By making the DC output voltage of the active filter variable, control of the high-frequency output voltage of the high-frequency inverter can be realized. Furthermore, as the switching means used for the high-frequency inverter, a voltage-controlled switching means such as a MOSFET or a current-controlled switching means such as a bipolar transistor can be used.
Since FET is a voltage control type switching means,
Easy to control. In addition, the MOSFET is effective as a power switching means that is less restricted by a safe operation area. In addition, enhancement type MOSFE
T is easy as a power-on process and is suitable as a power switching means. Furthermore, N channel type M
At present, OSFET is advantageous because its product lineup is abundant. However, if necessary, the P-channel type M
OSFETs can be used.

By the way, in the case of the switching means having a drive terminal, the drive means is turned on when a drive signal of a predetermined polarity is supplied to the drive terminal. In the enhancement type MOSFET, when a gate voltage, which is a drive signal, is applied between a gate, which is a drive terminal, and a source, a channel is formed to be turned on. Therefore, the off state is maintained when no gate voltage is applied. Further, a bipolar transistor whose switching means is a current control type is turned on by supplying a base current as a drive signal to a base which is a drive terminal.

In order to form a drive signal, a drive signal generation circuit corresponding to the drive signal can be provided.

<Regarding the operating frequency sweep control means>
The operating frequency sweep control means is a control means for sweeping the operating frequency of the high frequency inverter within a predetermined range when the high frequency inverter is started. In the present invention,
“Operating frequency sweep” means that the operating frequency is sequentially changed. Also, "to change sequentially" means
It is to change continuously or stepwise. further,
The `` predetermined range '' includes at least a frequency relatively close to the resonance frequency of the load resonance circuit and an operating frequency in a steady state relatively distant from the resonance frequency, and preferably the resonance frequency is an intermediate value. Including, means a range with a certain width. Furthermore, the phrase “when the high-frequency inverter is started” means that it includes at the same time as the start of the high-frequency inverter or after a certain time delay after the start.

Next, a configuration for sweeping the operating frequency of the high-frequency inverter will be described. When the high-frequency inverter is a self-excited type, it can be realized by sequentially changing the resonance frequency by, for example, changing the reactance of the switching resonance circuit.
On the other hand, in the case of the separately excited type, for example, it can be realized by sequentially changing the oscillation frequency of the oscillation circuit that determines the frequency of the drive signal.

The operating frequency sweep can be configured to be performed once or intermittently multiple times depending on the nature of the load. For example, when a DC power supply is obtained by rectifying a low-frequency AC, an operating frequency sweep can be performed in synchronization with the low-frequency AC, that is, for example, once in one cycle of the low-frequency AC. When the load requirement is satisfied, such as when the load is started by one operation frequency sweep, the operation frequency sweep is stopped. However, when the load requirement is not satisfied, the operation frequency sweep is repeated. It can be performed.

<Other Configurations> Starting Circuit A suitable starting circuit can be additionally provided to start the high-frequency inverter. For example, a DC power supply voltage dividing circuit mainly composed of a resistor may be configured to divide the DC power supply voltage to a drive terminal of a predetermined switching means so that a predetermined drive voltage is applied. In addition, by the circuit mainly composed of the time constant circuit and the trigger element,
A predetermined drive signal may be supplied from a DC power supply to a drive terminal of the predetermined switching means. Noise filter When a rectified DC power supply is used as a DC power supply, a noise filter is connected between the low-frequency AC power supply and the rectifier circuit so that the high-frequency noise generated by the switching of the switching means of the high-frequency inverter does not flow out to the low-frequency AC power supply. It can be inserted between the ends. Oscillation Stop Circuit If the load does not start even when the operating frequency sweep is performed when the high-frequency inverter is started, the operation of the high-frequency inverter can be stopped if necessary. Thereby, the high-frequency inverter can be protected.

<Function of the Present Invention> In the present invention, since the high frequency output is supplied from the high frequency inverter to the load circuit, the load is energized and operated by the high frequency. When the high-frequency inverter is started, the operating frequency of the high-frequency inverter is swept within a predetermined range by the operating frequency sweep control means. At that time, the high-frequency frequency changes within the predetermined range. On the other hand, since the load circuit includes the load resonance circuit, the degree of resonance of the load resonance circuit with respect to the applied high frequency changes sequentially with the sweep of the operating frequency. As a result, the terminal voltages of the first and second reactances change, and in the course of the change, when the frequency of the high frequency approaches the resonance frequency of the load resonance circuit, the degree of resonance increases. The terminal voltage of the reactance increases. When the resonance frequency of the load resonance circuit is included in the sweep range of the operating frequency, the highest voltage is obtained when the resonance frequency matches the operating frequency. Since the load is connected in parallel to one of the first and second reactances, a high secondary no-load voltage is applied to the load after the start-up. Therefore, even if the load requires a high voltage for starting, the starting can be easily and reliably performed without providing a special high voltage generating circuit such as an igniter. This means that the high-frequency power supply device can be small, light, and inexpensive. Further, since the load circuit has a load resonance circuit, even if the high-frequency output of the high-frequency inverter is a rectangular wave, the high-frequency voltage applied to the load is shaped into a sine wave by the resonance action.

Further, when rectifying the low-frequency AC voltage to obtain a DC power supply, the operating frequency may be swept so that the operation is completed within a half cycle of the low-frequency AC in synchronization with the low-frequency AC voltage. For example, when the low-frequency AC voltage is near the peak value, the operating frequency passes through the resonance frequency of the load resonance circuit, and the highest voltage is generated. For this reason, when the high-frequency output voltage of the high-frequency inverter includes flicker of the low-frequency AC voltage waveform, the highest voltage is generated by the operating frequency sweep when the high-frequency output voltage is high, so that a higher voltage is applied to the load. Can be applied.

Furthermore, since the operation frequency is swept after the high-frequency inverter is started, there is no shortage of the voltage applied to the load due to the starting failure of the high-frequency inverter.

Furthermore, by configuring the operating frequency when the sweep of the operating frequency is completed to be the switching frequency in the steady state, the control circuit is simplified.

According to a second aspect of the present invention, in the high frequency power supply device according to the first aspect, the operating frequency sweep control means includes a resonance frequency of the load resonance circuit when the load circuit is not loaded, including the resonance frequency. It is characterized in that the operating frequency is swept in a frequency range.

The sweep of the operating frequency may be performed from a higher frequency to a lower frequency in the frequency range, and vice versa.

Thus, in the present invention, since the sweep range of the operating frequency includes the resonance frequency of the load resonance circuit, the highest voltage is always obtained during the sweep. Therefore, even if there is a variation in the resonance frequency of the load resonance circuit, the maximum voltage is reliably obtained as the secondary no-load voltage, so that control for obtaining a high voltage after starting the high-frequency inverter becomes easy.

According to a third aspect of the present invention, in the high-frequency power supply device according to the first or second aspect, the load circuit saturates when the inductance of the inductive reactance constituting one reactance of the load resonance circuit is not loaded. It is characterized by doing.

According to the present invention, when the inductive reactance of the load resonance circuit is not loaded when the high-frequency inverter is started, the inductance is saturated. Then, as the saturation increases, the inductance decreases, and the resonance frequency of the load resonance circuit increases. For this reason, even if the operating frequency of the high-frequency inverter is constant, the operating frequency approaches the resonance frequency of the load resonance circuit, so that when the operating frequency of the high-frequency inverter is swept, the frequency range may be narrow.
Therefore, in the present invention, the circuit configuration of the operating frequency sweep control means is simplified.

According to a fourth aspect of the present invention, in the high frequency power supply device according to the second or third aspect, the operating frequency sweep control means sweeps the operating frequency from a high frequency to a low frequency. I have.

In the present invention, the sweep of the operating frequency of the high-frequency inverter starts from a frequency higher than the resonance frequency of the load resonance circuit in a no-load state, and passes through the resonance frequency of the load resonance circuit on the way to a lower frequency. Then, when passing through the resonance point of the load circuit, the highest voltage is generated and applied to the load as a secondary no-load voltage. Therefore,
Since the sweep of the operating frequency is started from the late-phase switching, the switching loss is small, so that the switching means is hardly stressed. However, when the operating frequency sweep passes through the resonance point of the load resonance circuit, the phase shifts into the fast switching region.However, in a configuration in which the inductive reactance of the load resonance circuit saturates in a no-load state, it is delayed for the following reason. A steady operating frequency can be achieved in the phase switching region. That is, the load current starts to flow when the load is started after the highest voltage is applied during the operation frequency sweep, but at the same time, the saturation state of the inductive reactance ends, the inductance increases again, and the load resonance starts. Since the resonance frequency of the circuit decreases, the switching at this time can be configured to be located in the slow switching region of the resonance characteristic curve in the non-saturated state. For this reason, the switching in the advanced switching region is completed within a short time.

According to a fifth aspect of the present invention, in the high frequency power supply device according to the second or third aspect, the operating frequency sweep control means sweeps the operating frequency from a low frequency to a high frequency. I have.

In the present invention, the sweep of the operating frequency of the high-frequency inverter starts at a frequency lower than the resonance frequency of the load resonance circuit in the no-load state, and passes through the resonance frequency of the load resonance circuit on the way to a higher frequency. Then, when passing through the resonance point of the load circuit, the highest voltage is generated and applied to the load.

Further, since the sweep ends at a high operating frequency after passing through the resonance point of the load resonance circuit, the steady state always occurs in the slow switching region regardless of whether the inductive reactance of the load resonance circuit is saturated. . Therefore, since the switching loss is small, stress does not easily act on the switching means in the high-frequency inverter. Further, in the case of a configuration in which the inductive reactance of the load resonance circuit is saturated in a no-load state, when the high-frequency inverter is started, the inductance is saturated and becomes smaller. At the same time, the operating frequency of the high-frequency inverter is swept, and the resonance frequency of the load resonance circuit increases. That is, the operating frequency of the high-frequency inverter follows the change in the resonance frequency of the load resonance circuit and changes in the same direction. As a result, from the viewpoint of the load resonance circuit, the period during which the operating frequency stays near the resonance frequency is lengthened, so that a high secondary no-load voltage can be generated for a time period of, for example, several cycles. When the load is, for example, a discharge lamp, the time during which a high voltage is applied can be lengthened, so that glow-arc transition can be ensured at the time of starting, and the lamp can be turned on.

According to a sixth aspect of the present invention, there is provided the high frequency power supply device according to any one of the first to fifth aspects, wherein the high frequency inverters are connected in series, and a DC input voltage is applied between both ends and alternately. A half-bridge type inverter including first and second switching means for switching; a load circuit is connected in parallel to a second switching means of the high-frequency inverter.

The fact that the first and second switching means are connected in series means that the first and second switching means are connected in series as viewed from the DC voltage source, and the first and second switching means are connected in series. Means that another circuit component, such as a resistor, may be interposed between the switching means and the DC voltage source, and that a circuit component may be interposed between the first and second switching means. I do.

Further, in order to alternately switch the first and second switching means, a drive circuit can be added to each of the first and second switching means. In the present invention, the half-bridge type inverter may be either a self-excited type or a separately-excited type. Therefore, the drive circuit can adopt each known circuit configuration according to the excitation type of the high-frequency inverter.

The operating frequency sweep control means can sweep the operating frequency by acting on the drive circuits of the respective switching means and sequentially changing the frequency of the drive signal.

In the present invention, since the high-frequency inverter is a half-bridge type inverter, the circuit configuration is simple and the number of circuit components is small, so that the size, weight and cost are reduced.

According to a seventh aspect of the present invention, in the high frequency power supply device according to any one of the first to sixth aspects, the high frequency inverter includes an inductive reactance among the first and second reactances of the load circuit. It is characterized by including a synchronous winding that is magnetically coupled, and a switching resonance circuit that determines the switching frequency of the switching means by exhibiting resonance when a voltage induced in the synchronous winding is applied.

The present invention specifies the configuration of a drive circuit suitable for a self-excited high-frequency inverter. The synchronous winding is
The high frequency output of the high frequency inverter is fed back from the load circuit. When the high-frequency inverter includes a plurality of switching means, a single synchronous winding may be provided in common for each switching means, but if necessary, a synchronous winding is provided for each switching means. You can also.

The switching resonance circuit includes first and second switching resonance circuits.
It is preferable to synchronize the pair of switching resonance circuits by disposing the inductive reactances with each other and magnetically coupling the inductive reactances to each other. However, if necessary, a single switching resonance circuit is used, and a drive signal is alternately distributed to both drive terminals of the first and second switching means by using a transformer. It may be configured as follows. Note that the transformer may be provided separately from the switching resonance circuit,
The transformer may be configured by magnetically coupling the inductive reactances of the switching resonance circuit directly to each other.

Also, the switching resonance circuit determines the switching frequency of the switching means and hence the operating frequency of the high-frequency inverter by applying a feedback voltage induced to the synchronous winding to resonate with the resonance frequency of the switching resonance circuit. The switching resonance circuit is constituted by an inductive reactance and a capacitive reactance. In at least one of the switching resonance circuits, a MOSFET is used as a switching means.
Is used, capacitive reactance can be obtained by utilizing the input capacitance generated between the gate and the source. In order to make the inductive reactance as small as possible, it is preferable to use a core having an air gap or to make it in the air core. This makes it difficult for the inductor to be magnetically saturated even if it is small.

In order to regulate the drive signal to a voltage having a predetermined value, a voltage clamp circuit can be used as a drive protection circuit if necessary. The drive protection circuit is the first
In order to prevent an excessive voltage from being applied to the drive terminal of the second switching means, any specific circuit configuration may be used. For example, a drive protection circuit can be configured by connecting at least two or more zener diodes in series with opposite polarities. By connecting a switching resonance circuit to this drive protection circuit in parallel, it is possible to perform a protection function against positive and negative bipolar resonance voltages. Further, the gate protection circuit can be configured by various similar circuit configurations as long as it is a constant voltage element, without using a Zener diode. Further, the number of constant voltage elements to be used may be determined according to the relationship between the constant voltage and the drive voltage. Then, the voltage component that becomes overvoltage with respect to the drive terminal is short-circuited and absorbed by the drive protection circuit, so that only a voltage of an appropriate value is applied to each drive terminal of the first and second switching means. . When an overvoltage is applied to the switching means, the switching means may be destroyed. Therefore, it is preferable to add a drive protection means.

Further, a capacitor having a relatively large capacity can be interposed between the switching resonance circuit and the drive terminal of the switching means electrically connected to the switching resonance circuit.

The discharge lamp lighting device according to the eighth aspect of the present invention
A high-frequency power supply according to any one of claims 1 to 7, and a discharge lamp connected as a load to a load circuit of the high-frequency power supply.

In the present invention, in the discharge lamp, since a part or all of one of the first and second reactances of the load resonance circuit acts as a current limiting impedance, the discharge lamp compensates for the negative characteristics of the discharge lamp and is stable. Lights up. At this time, part or all of the other reactance acts to determine the voltage applied to the discharge lamp.

The discharge lamp may be any of a low-pressure discharge lamp such as a fluorescent lamp and a high-pressure discharge lamp such as a metal halide lamp.

When the discharge lamp is a low-pressure discharge lamp such as a fluorescent lamp, uses a filament electrode, and starts the discharge lamp using the filament electrode as a hot cathode, a method of heating the filament electrode at the start is as follows. There are the following two types. The first is to connect the reactance which is connected in parallel with the load in parallel with the discharge lamp via at least one filament electrode at the time of starting. Then, at start-up, the current flows through the one reactance in series with the load and the other reactance in parallel to the filament of the electrode, so that the filament is heated. At the same time, the first and second reactances appropriately resonate in series, and the terminal voltage of the reactance connected in parallel to the discharge lamp increases, so that the starting of the discharge lamp is promoted. The second is to heat the filament electrode using a filament heating transformer. The filament heating transformer may be provided separately from the reactance acting as the current limiting impedance, but if necessary, the filament heating winding can be magnetically coupled to the reactance. that way,
An increase in the number of circuit components can be suppressed. Further, an instant start in which the discharge lamp is started by applying a high voltage between the pair of electrodes without preheating may be performed.

Next, when the discharge lamp is a high-pressure discharge lamp, there is no need to heat the filament as in a fluorescent lamp. Therefore, it is necessary to start directly using a high voltage generated by sweeping the operating frequency of the high-frequency inverter. General. In order to reduce the starting voltage as much as possible, it is effective to provide a starting auxiliary conductor in the high-pressure discharge lamp.

Also, the present invention sweeps the operating frequency of the high-frequency inverter when starting the high-pressure discharge lamp. Since a high-frequency power supply that can generate a high secondary no-load voltage is used,
It is very suitable for starting and operating a high-pressure discharge lamp having a lamp power of 50 W or less, preferably about 10 to 30 W, without using an igniter.

According to a ninth aspect of the present invention, there is provided a discharge lamp lighting device comprising:
The discharge lamp lighting device according to claim 8, wherein the discharge lamp is a high-pressure discharge lamp. In recent years, small metal halide lamps having a lamp power of about 10 to 30 W have been developed as light sources for optical fibers and light sources replacing halogen lamps. Such a metal halide lamp has a lamp efficiency of about 3 times as compared with a halogen bulb.
It is up to four times, and significantly smaller than a bulb-type fluorescent lamp, so that it can be treated as a point light source. Therefore, it can be said that the above-mentioned small metal halide lamp is a light source having advantages of the halogen bulb and the bulb-shaped fluorescent lamp. According to the present invention, the small high-pressure discharge lamp as described above can be lighted by using the high-frequency power supply device, and the entire discharge lamp lighting device constituted thereby can be significantly reduced in size. Become. Hereinafter, a configuration example of this type of high-pressure discharge lamp will be described. That is, a high-pressure discharge lamp suitable for use in the present invention includes at least a translucent ceramics discharge vessel, a pair of electrodes, an introduction conductor, and a discharge medium.

<About the translucent ceramics discharge vessel>
The term “translucent” refers to light transmissivity to the extent that light generated by discharge can be transmitted to the outside, and may be not only transparent but also light diffusive. When the translucent ceramics discharge vessel has a small-diameter cylindrical portion, it is sufficient that at least the surrounding portion has a light-transmitting property with respect to the radiation to be used. May not be mainly derived.

Accordingly, the “translucent ceramics discharge vessel” is defined as a single-crystal metal oxide such as sapphire having at least a surrounding portion, a polycrystalline metal oxide such as a translucent hermetic aluminum oxide (alumina ceramic), Yttrium-aluminum-garnet (YA
G) means a discharge vessel made of a material having light transmittance and heat resistance such as yttrium oxide (YOX) and a polycrystalline non-oxide such as aluminum nitride (AlN).

In order to manufacture a translucent ceramics discharge vessel, a central surrounding portion and a small-diameter cylindrical portion at both ends or one end of the surrounding portion can be integrally formed from the beginning. However, for example, the hollow spherical portion forming the surrounding portion and the small-diameter cylindrical members connected to both ends of the spherical portion to form the small-diameter cylindrical portion are separately pre-sintered and then joined as required, and By sintering, an integral translucent ceramics discharge vessel can be formed. Furthermore, for example, a cylinder forming an enclosing portion, a pair of end plates that are fitted and closed at both end surfaces of the cylinder, and a small-diameter tubular body that is fitted into a center hole of the end plate to form a small-diameter tubular portion, An integral discharge vessel can also be formed by separately sintering and fitting each other as required and sintering the whole.

Further, in the present invention, the inner volume of the translucent ceramics discharge vessel is not limited, but in order to obtain a small high-pressure discharge lamp, the translucent ceramics discharge vessel must be 0.05 cc or less. Preferably 0.04cc
It is better to do the following. In this case, the translucent ceramics discharge vessel has a total length of 35 mm or less, preferably 10 to 30 mm.
mm.

<Regarding a Pair of Electrodes> The pair of electrodes is sealed in a translucent ceramic discharge vessel, and uses tungsten or doped tungsten as a material.
In addition, the electrode is inserted into the small-diameter cylindrical portion of the translucent ceramics discharge vessel, and further the tip is located in the surrounding portion,
Alternatively, the tip is also located in the small-diameter cylindrical portion, but may be located at a position where the surrounding portion is desired and formed so as to form a discharge in the surrounding portion.

Further, the electrode has a small gap called a capillary between the electrode and the inner surface of the small-diameter cylindrical portion in a state of being inserted into the elongated small-diameter cylindrical portion. In this case, it is desirable that the intermediate portion of the electrode has a constant thickness in order to form as small a gap as possible as uniform as possible with the inner surface of the small-diameter cylindrical portion of the translucent ceramics discharge vessel.

Further, a tungsten coil can be wound around the tip of the electrode as necessary to increase the surface area and improve heat dissipation. In addition, the base end of the electrode is fixed at a required position with respect to the translucent ceramics discharge vessel and functions to introduce a current from the outside. Furthermore, the base end of the electrode can be electrically and mechanically supported by being fixed to the front end of the power supply conductor by welding or the like. In this case, if necessary, the power supply conductor may be provided with a member such as molybdenum, cermet, or the like interposed between the base end of the electrode and the base end of the electrode as a refractory portion.

<Introduction Conductor> The introduction conductor is used to support the electrodes, supply power to the electrodes, and seal the translucent ceramic discharge vessel. That is, the introductory conductor is a conductor that supports the electrodes, applies a voltage between the electrodes, supplies a discharge current to the electrodes, and functions to seal the translucent ceramic discharge vessel. The electrode is connected to the base end of the electrode through a refractory part provided, and the base end is led out of the translucent ceramics discharge vessel. In addition, the phrase “leaded out of the translucent ceramics discharge vessel” may or may not protrude from the translucent ceramics discharge vessel to the outside. It means that you are facing the outside enough to be able to supply power from outside.

Also, the introduction conductor may be used to support the entire high-pressure discharge lamp by supporting it.

Further, the introduction conductor is niobium, tantalum,
Sealing metals such as titanium, zirconium, hafnium and vanadium can be used. When alumina ceramics is used as the material of the translucent ceramics discharge vessel, niobium and tantalum are suitable for the introduction conductor since the average thermal expansion coefficient is almost the same as that of alumina ceramics. Also, there is little difference between yttrium oxide and YAG. When aluminum nitride is used for the translucent ceramics discharge vessel, zirconium is preferably used for the introduction conductor.

Further, the introduction conductor can be constituted by a rod-like body, a pipe-like body, a coil-like body or the like of the above-mentioned metal. In this case, niobium is an oxidizing metal,
If the high-pressure discharge lamp is to be lit while exposed to the atmosphere, it is necessary to further connect an oxidation-resistant external lead wire to the power supply conductor and cover the whole with a seal, for example, so that the introduction conductor does not come into contact with the atmosphere. There is.

Further, as described above, a refractory portion made of a refractory metal can be added to the tip of the introduction conductor. Molybdenum, tungsten, cermet, or the like can be used for the refractory portion. However, if necessary, the base end of the electrode may be directly connected to the front end of the sealing portion of the power supply conductor. This means that the refractory portion can be used as an electrode if at least the tip portion of the refractory portion added to the introduction conductor is made of tungsten. Conversely, the base end of the electrode can be used as a refractory part, and both are substantially the same.

<Discharge Medium> The discharge medium contains at least a rare gas as a starting gas and a buffer gas, and is sealed in a translucent ceramic discharge vessel so as to exhibit a pressure of about 1 atm or more during lighting. The discharge medium contains a luminescent substance or a compound thereof, such as a metal halide or amalgam. Further, the discharge medium can include mercury as a buffer vapor.

On the other hand, the rare gas is not essentially limited to a specific gas. However, it is necessary to reduce the glow current at the time of transition from the normal glow discharge to the abnormal glow discharge or to reduce the discharge starting voltage. At times, neon and argon can be mixed and encapsulated. In this case,
Argon can be mixed with neon in a partial pressure range of 0.1 to 15%, preferably up to 10%. Also, neon and argon are generally 80 to 500 t
orr, preferably at a fill pressure of 100 to 200 torr. If the filling pressure is less than 80 torr, the glow-arc transition time becomes long, and blackening due to sputtering or evaporation of tungsten of the electrode material increases. On the other hand, when the filling pressure exceeds 500 torr, the starting voltage of the high-pressure discharge lamp increases, and the glow power increases. Further, in addition to neon and argon, other rare gases can be filled as required.

In the case where the high-pressure discharge lamp is a metal halide lamp, when a metal halide of a luminescent metal is used as a discharge medium, the halogen constituting the metal halide may be any one of iodine, bromine, chlorine or fluorine, or A plurality of types can be used. The metal halide of the luminescent metal, the emission color, the average color rendering index Ra and luminous efficiency, etc., in order to obtain radiation with desired luminescence characteristics, furthermore, depending on the size and lamp power of the translucent ceramics discharge vessel, Any desired selection can be made from known metal halides. For example, one or more halides selected from the group consisting of sodium Na, lithium Li, scandium Sc and rare earth metals can be used.

Further, instead of an appropriate amount of mercury as the buffer vapor, a metal having a relatively high vapor pressure and low luminescence in the visible light region, or a non-luminous metal such as aluminum or a halide such as aluminum can be sealed.

<Other Configurations> (1) Outer tube The high-pressure discharge lamp suitable for use in the present invention can be configured to be lit when the translucent discharge vessel is exposed to the atmosphere. . However, if necessary, the translucent discharge container can be hermetically stored in the outer tube. In addition, a high-pressure discharge lamp having directivity can be obtained by forming the inner surface of the outer tube as a reflection surface having a light-emitting portion of the high-pressure discharge lamp as a focal point.

(2) Reflecting Mirror The high-pressure discharge lamp suitable for use in the present invention has a light-emitting portion that can be reduced in size, so that it is easy to collect light and is optically advantageous. It can be used integrally with a reflecting mirror. In this case, a reflecting mirror may be formed on the inner surface of the outer tube accommodating the translucent discharge vessel therein, or the high-pressure discharge lamp may be assembled to a separate reflecting mirror.

Thus, in the present invention, the operating frequency of the high-frequency inverter is determined by the resonance frequency of the switching resonance circuit, so that the high-pressure discharge lamp of the load can be lit at a constant frequency while it is lit. For this reason, the load is a high-pressure discharge lamp provided with a translucent ceramics discharge vessel, and even if a short circuit occurs, an extremely large short-circuit current does not flow, so that the high-pressure discharge lamp does not break. On the other hand, when the high-pressure discharge lamp is short-circuited without using the present invention, the terminal voltage of the inductive reactance acting as a current-limiting impedance at that time decreases, so that the switching of the high-frequency inverter fails. As a result, the device operates at a load resonance frequency lower than the normal operation frequency. For this reason, a larger short-circuit current flows, and if the high-pressure discharge lamp is provided with a translucent ceramics discharge vessel, it will be destroyed.

Therefore, the present invention is particularly effective when the high-pressure discharge lamp includes a translucent ceramic discharge vessel.

A lighting device according to a tenth aspect of the present invention is characterized by comprising a lighting device main body; and a discharge lamp lighting device according to the eighth or ninth aspect supported by the lighting device main body.

In the present invention, the term “illumination device” is a broad concept including any device utilizing the light emission of a discharge lamp, and is, for example, a lighting device, a backlight device such as a liquid crystal device, a personal computer or a television incorporating the same. It includes various information devices such as a receiver and a GPS device, an image reading device and an OA device such as a copying machine, a facsimile, and a scanner incorporating the image reading device, and a bulb-type high-pressure discharge lamp.

In particular, in the present invention, since the discharge lamp lighting device can be remarkably miniaturized, it is suitable for a small compact fluorescent lamp. The "bulb-shaped high-pressure discharge lamp"
A high-pressure discharge lamp and a lighting device thereof are mechanically connected to each other and a base is attached to the lighting device. The lighting device is configured to be mounted in a lamp socket and lighted in the same manner as an incandescent lamp. In addition, a lighting device provided with a bulb-type high-pressure discharge lamp also constitutes the lighting device according to the present invention.

[0076]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

In the figure, AS is a low-frequency AC power supply, NF
Denotes a noise filter, RDC denotes a rectified DC power supply, HFI denotes a high-frequency inverter, LC denotes a load circuit, FSC denotes operating frequency sweep control means, and OSC denotes oscillation stop means.

<Regarding Low Frequency AC Power Supply AS> The low frequency AC power supply AS is a commercial 100 V AC power supply.

<Regarding Noise Filter NF> The noise filter NF is composed of a low-frequency AC power supply AS and a rectified DC power supply R.
D in series to prevent high-frequency noise generated by the alternate switching of the first and second switching means Q1, Q2 of the high-frequency inverter HFI from flowing out to the low-frequency AC power supply AS. is there. Then, the inductor L1 and a capacitor C1 connected in parallel to the low-frequency AC power supply AS on the low-frequency AC power supply AS side of the inductor L1 and forming an inverted L-shaped circuit together with the inductor L1.

<Regarding Rectified DC Power Supply RDC> The rectified DC power supply RDC includes a bridge type full-wave rectifier circuit BRC, an inrush current suppressing resistor R1, and a smoothing capacitor C2. The AC input terminal of the bridge-type full-wave rectifier circuit BRC is connected to the low-frequency AC power supply AS via a noise filter NF. The inrush current suppressing resistor R1 is connected in series between the positive electrode of the bridge type full-wave rectifier circuit BRC and the smoothing capacitor C2. The both ends of the smoothing capacitor C2 are connected between the DC output terminals of the bridge type full-wave rectifier circuit BRC via a rush current suppressing resistor R1 in series.

<Regarding High Frequency Inverter HFI> The high frequency inverter HFI is composed of a half-bridge type inverter and has first and second switching means Q1, Q2.
2. It is configured to include a start circuit ST and first and second drive circuits DC1 and DC2.

(First and Second Switching Means Q
The first and second switching means Q1 and Q2 each comprise an enhancement-type N-channel MOSFET and are connected in series. The drain of the first switching means Q1 is connected to the positive electrode of the rectified DC power supply RDC, the source is connected to the drain of the second switching means Q2, respectively, and the source of the second switching means Q2 is connected to the rectified DC power supply RDC. Is connected to the negative electrode. Note that a capacitor C3 is connected between the drain and source of the second switching means Q2 to suppress noise appearing between the drain and source of the second switching means and improve switching.

(Regarding Startup Circuit ST) Startup circuit ST
Comprises a series circuit of a resistor R2, a first drive protection circuit DP1, and a load circuit LC. One end of the resistor R2 has a noise filter NF and a rectified DC power supply RDC.
And the other end is connected to the gate of the first switching means Q1. The first drive protection circuit DP1 includes a pair of zener diodes ZD11 and ZD21 connected in series with opposite polarities, and is connected between the gate and source of the first switching means Q1.

(First Drive Circuit DC1) The first drive circuit DC1 includes a synchronous winding SW1, a first switching resonance circuit SRC1, a capacitor C4, and a first drive protection circuit DP1. Synchronous winding SW1
, Together are magnetically coupled to the inductive reactance X _L will be described later load circuit LC, one end is connected to the source of the first switching means Q1. First switching resonant circuit SRC1 is formed by the capacitive reactance constituted by the input capacity of the inductive reactance X _L1 and the first switching means Q1. Then, the resonance output of the first switching resonance circuit SRC1 is applied between the gate and the source of the first switching means Q1 via the capacitor C4. First drive protection circuit G
P1 is connected as described above, and clamps an excessive part of the resonance output of the first switching resonance circuit SRC1 applied between the gate and source of the first switching means Q1.

(About the Second Drive Circuit DC2) The second drive circuit DC2 includes a synchronous winding SW2, a second switching resonance circuit SRC2, a capacitor C5, and a second drive protection circuit DP2. Synchronous winding SW2
, Together we are magnetically coupled to the inductive reactance X _L of the load circuit LC which will be described later with synchronized winding SW1, one end is connected to a source of the second switching means Q2. The second switching resonance circuit SRC2 includes an inductive reactance X _L2 , a capacitor C6 and a second
Are formed by constituted capacitive reactance X _C2 of the input capacitance of the switching means Q2. The capacitor C6 is provided with an operating frequency sweep means FS described later.
The effective capacitance is controlled by the conduction control means CC of C. Also synchronization is achieved by the inductive reactance X _L2 and the inductive reactance X _L1 is magnetically coupled to each other. The resonance output of the second switching resonance circuit SRC2 is applied between the gate and the source of the second switching means Q2 via the capacitor C5. The second drive protection circuit GP2 includes a pair of zener diodes ZD12 and ZD22 connected in series with opposite polarities, and is connected between the gate and source of the second switching means Q2. Thus, an excessive part of the resonance output of the second switching resonance circuit SRC2 applied between the gate and the source of the second switching means Q2 is clamped.

(Other Configurations) A resistor R3 and a second drive protection circuit DP2 are connected in parallel with the load circuit LC.
Are connected in series. That is, the resistor R3
Is connected between the drain and the gate of the second switching means Q2.

<About Load Circuit LC> Load Circuit LC
Comprises a load resonance circuit LRC, a DC cut capacitor C7, and a load DL.

The load resonance circuit LRC includes a first reactor
X_LAnd the second reactance X _CSeries resonance circuit
Has formed. First reactance X_LAt no load
Is it a saturable inductor whose inductance saturates?
Become. Second reactance X_CIs from capacitor C8
Become.

The DC cut capacitor C7 is connected in series with the load resonance circuit LRC and prevents DC from flowing through the load circuit LC. It should be noted that the DC cut capacitor C7 hardly contributes to the load resonance circuit LRC because of its large capacitance. Load DL is made from the high-pressure discharge lamp is connected in parallel with the second reactance X _C. Load DL
Will be described later in detail.

<Regarding the Operating Frequency Sweep Means FSC> The operating frequency sweep means FSC includes the conduction control means CC.
And a time constant circuit TC.

The conduction control means CC is composed of a MOSFET connected in series with the capacitor C6 in the second switching resonance circuit SRC2, and the degree of conduction is made variable by controlling the potential of its gate.

The time constant circuit TC comprises a series circuit of a resistor R4 and a capacitor C9. One end of the resistor R4 is
The second drive protection circuit DP2 is connected to a connection point between the Zener diodes ZD1 and ZD2 in the second drive protection circuit DP2, and the other end is connected to the gate of the conductivity control means CC. Capacitor C
9 is connected between the gate and the source of the conductivity control means CC. A resistor R5 is connected to both ends of the capacitor C9 so that the capacitor C9 is not charged when charging is not performed.
9 are discharged.

<Regarding Oscillation Stopping Means OSC> The oscillation stopping means OSC mainly includes a switching means Q3, a voltage divider VD, a reference voltage element ZD3, and a capacitor C10. The switch means Q3 is composed of a MOSFET, and its drain and source are connected to both ends of the Zener diode ZD22 of the second drive protection circuit DP2. The voltage divider VD includes a series circuit of resistors R6 and R7 connected between both ends of the load DL and resistors R6 and R7.
The diode D1 has an anode connected to a connection point of the resistor R7, and a divided voltage appearing across the resistor R7 is extracted through the diode D1. The reference voltage element ZD3 is composed of a Zener diode, and conducts when the output of the voltage divider VD exceeds its reference voltage to charge the capacitor C10. When the voltage of the capacitor C10 exceeds the threshold voltage of the switch Q3, the switch Q3 turns on.

When the switching means Q3 is turned on, the Zener diode ZD21 conducts, and the gate and source of the switching means Q2 are short-circuited.

<Regarding Circuit Operation> (Regarding Operation of Half-Bridge Inverter) When the low-frequency AC power supply AS is turned on, a DC voltage smoothed by the rectified DC power supply RDC appears at both ends of the smoothing capacitor C2. Then, a DC voltage is applied between the drain and the source of the first and second switching means Q1, Q2 connected in series of the high-frequency inverter HFI. However, the first and second switching means Q1, Q2 remain off because no drive voltage is applied.

In the figure of the low-frequency AC power supply AS, the half-wave voltage of the low-frequency AC voltage is changed to the resistance R2, the first drive protection circuit DP1,
First reactance X _L of the load _circuit, is applied to the series circuit of the DC cut capacitor C7 and the second reactance X _C charges the second reactance X _C and. At this time, a voltage drop occurs in the first drive protection circuit DP1, and when this voltage is applied between the gate and the source of the first switching means Q1, the first switching means Q1
Since the threshold voltage is exceeded, a channel is formed and turns on. At the same time as the above, the resistor R2 and the first
Is applied also to the series circuit of the drive protection circuit DP1, the resistor R3 and the second drive protection circuit DP2, but in this state, the second drive protection circuit DP2 does not conduct. Accordingly, the second switching means Q2 remains off because no voltage is applied to its gate.

When the first switching means Q1 turns on, the high-frequency inverter HFI starts. Then, the load circuit LC is connected from the positive electrode of the rectified DC power supply RDC via the drain / source of the first switching means Q1.
That first reactance X _L, the DC cut capacitor C7, the path of the negative electrode current flows through the second reactance X _C and rectified DC power supply RDC. First reactance X _L and in this case the load circuit LC, the terminal voltage of the second reactance X _C becomes high load resonance circuit LRC second reactance X _C resonates.

[0099] On the other hand, when a current flows through the first reactance X _L, synchronization windings are magnetically coupled to SW
1. A voltage having a polarity that causes the terminal without the polarity symbol attached in the figure to be higher is induced in SW2. Voltage towards terminal no polarity symbols in voltage drop illustrations in this case first reactance X _L becomes higher.

When the voltage induced in the synchronous winding SW1 is applied to the first switching resonance circuit SRC1, the first switching resonance circuit SRC1 and the second switching resonance circuit SRC2 have their inductive reactance X _L1 ,
Since _XL2 is electromagnetically coupled, it resonates in synchronization. This resonance is performed by the second switching resonance circuit. Then, the gate voltage of the first switching means Q1 rises due to the resonance, and the first switching means Q1 is continuously in the ON state.

However, the second switching resonance circuit SR
Since the voltage applied from C2 to the second switching means Q2 is opposite in polarity and lower than the source, the second switching means Q2 remains in the off state.

However, since the resonance operations are synchronized,
Next, the polarity is simultaneously reversed by the vibration due to the resonance. At that time, the gate of the first switching means Q1 is turned off by the reverse voltage, and conversely, the second switching means Q1 is turned off.
The second drive voltage in the forward direction is applied to the gate of No. 2 to turn it on.

Therefore, the first switching means Q1
The on-time of the inductive reactance X of the second switching resonance circuit SRC1 of the second drive circuit GDC2
It is determined by the effective capacitance of the capacitor C6 of the inductance and the capacitive reactance X _C2 of _L2.
The capacitances of the capacitors C4 and C5 are selected to be large enough not to affect the values and phases of the positive and negative gate voltages.

[0104] When the first switching means Q1 is turned off, is electromagnetic energy emitted accumulated in the inductive reactance X _L, DC from the inductive reactance X _L cut capacitor C7, the capacitive reactance X _C, the second
The While the path of the parasitic diode and an inductive reactance X _L of the switching means Q2 continues subsequently passing a current, if the current becomes zero, this time a DC electric charge of the capacitor C8 is cut capacitor C7, the inductive reactance X _L, the 2 to discharge the path of the switching means Q2 and capacitive reactance X _C, current flows in a direction opposite to the above. At this time, the voltage induced in the synchronous winding SW1, SW2 for magnetic coupling to the inductive reactance X _L, high terminal of the person who polarity symbols in the figure attached to the contrary, since the other terminal becomes lower, First switching resonance circuit SRC1
The first switching means Q1 to which the resonance voltage is applied via the second switching circuit SRC2 maintains the off state, and the second switching means Q2 to which the resonance voltage is applied via the second switching resonance circuit SRC2 maintains the on state. .

However, the first and second switching resonance circuits SRC 1 and SR C 1 of the first drive circuit GDC 1
When the resonance voltage of C2 oscillates synchronously and the polarity is inverted,
Again, the first switching means Q1 turns on and the second switching means Q2 turns off.

[0106] As a result, after the electromagnetic energy accumulated in the inductive reactance X _L is released, again flow from the positive electrode of the rectification DC source RDC, the first current as described load circuit LC. Hereinafter, by repeating the above-described operation, the high-frequency inverter HFI operates as a half-bridge inverter.

(Regarding the Operating Frequency Sweep) By the way, when the high-frequency inverter HFI is activated and the first switching means Q1 is turned on, the second drive protection circuit DP2 is connected via the first switching means Q1 and the resistor R3. Since the DC voltage is applied, the operating frequency sweep circuit FSC starts operating. That is, since the time constant circuit TC responds to the voltage drop of the Zener diode ZD22, the terminal voltage of the capacitor C9 starts increasing.
For this reason, the conduction control means CC sequentially conducts, and the capacitive reactance X _{C2 of} the second switching resonance circuit SRC2.
, The effective capacitance increases, so that the resonance frequency decreases. As a result, when the high-frequency inverter HFI is activated, the operating frequency of the high-frequency inverter HFI changes from a high frequency every one cycle of the power supply voltage of the low-frequency AC power supply AS with a rise in the voltage of the time constant circuit TC during the half cycle. Swept towards lower frequencies.

FIG. 2 is a waveform diagram for explaining changes in voltage and frequency of each part in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

In the figure, (a) is the low-frequency AC power supply voltage, (b) is the voltage of the drive signal of the second switching means, (c) is the output voltage of the time constant circuit of the operating frequency sweep control means, (d) ) Indicates the operating frequency.
That is, as shown in (a), when the low-frequency AC power supply AS is turned on at time t0 and the high-frequency inverter HFI is started at time t1, the drive circuit CD as shown in (b)
1. The supply of the drive signal to CD2 is started. At the same time, the time constant circuit TC starts operating, and the voltage starts to rise. When the charging voltage of the time constant circuit TC exceeds the reference voltage of the reference voltage element ZD3 at the time point t2, the operating frequency sweep control means FSC starts to operate, and the operating frequency of the high-frequency inverter HFI changes from a high frequency to a low frequency. Since the sweep starts, the operating frequency gradually decreases as shown in (d), and the operating frequency at the end of the sweep becomes the frequency at the steady state as it is. Note that t from the start of the high-frequency inverter HFI to the start of the operating frequency sweep is t.
In the period between 1 and t2, the resonance frequency of the first switching resonance circuit SRC2 becomes constant as the operating frequency.

FIG. 3 is a graph showing a resonance characteristic curve of the load resonance circuit at the time of no load in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

In the figure, the horizontal axis indicates the operating frequency, and the vertical axis indicates the voltage. f0 is the resonance frequency, f1 is the frequency at the start of the sweep, f2 is the frequency at the end of the sweep,
Are respectively shown. That is, the sweep range of the operating frequency is performed between the frequencies f1 and f2. The resonance point is included in the middle of the sweep, so that the highest voltage can be generated. Hereinafter, with reference to FIGS. 4 to 6, the drain current flowing through the secondary open-circuit voltage V ₂₀ and the second switching element Q2 in the soup operating frequency I _Q2
Will be described.

FIG. 4 shows the high-frequency power supply device and the discharge lamp lighting device according to the first embodiment of the present invention at the time of no load and at the start of the operating frequency sweep, and flows through the secondary open-circuit voltage and the second switching means. FIG. 4 is a waveform diagram showing a drain current.

[0113] The operating frequency is 300kHz, 2-order open-circuit voltage _{V 20} obtained is 300 vp-p.

FIG. 5 shows the secondary open-circuit voltage and the second switching means at the time of no load and at the resonance frequency of the load resonance circuit in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention. It is a waveform diagram which shows the drain current which flows.

[0115] The operating frequency is 225 kHz, 2-order open-circuit voltage _{V 20} obtained is 4kVp-p.

FIG. 6 shows the secondary open-circuit voltage and the drain flowing through the second switching means at the time of no load and at the end of the operating frequency sweep in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention. FIG. 4 is a waveform diagram showing a current.

[0117] The operating frequency is 150 kHz, 2-order open-circuit voltage _{V 20} obtained is 400Vp-p.

[0118] Incidentally, in this embodiment, the inductive reactance X _L of the load circuit LC, the inductance at the time of no load is saturable shaped saturated. Therefore, in the state in which the high frequency inverter HFI is not started load DL when starting, because the inductive reactance X _L is saturated, the inductance thus reactance decreases, it resonance frequency of the load resonance circuit LRC is under load It is higher in comparison. Since the resonance frequency of the load resonance circuit LRC at the time of no load is set within the sweep range of the operating frequency, a high voltage is applied to the load DL near the resonance frequency, and the load DL
Starts easily.

[0119] When the load DL is started, the inductance of the inductive reactance X _L is increased back to the original,
The resonance characteristic of the load resonance circuit LRC changes to a lower operating frequency.

FIG. 7 is a graph showing the resonance characteristic curves of the load resonance circuit in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention when there is no load and when there is a load.

In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted. That is, the resonance characteristics of the load resonance circuit differ between when no load is applied and when the load is applied, and the frequency shifts to a lower value when the load is applied. In the drawing, a curve A indicates a resonance characteristic curve when no load is applied, and B indicates a resonance characteristic curve when load is applied.

(Regarding Oscillation Stopping Operation) When the high-frequency inverter HFI is started, the operating frequency is swept and the load D
The no-load secondary voltage applied to both ends of L rises,
Accordingly, when the output of the voltage divider VD of the oscillation stop circuit OSC rises and exceeds the reference voltage of the reference voltage element ZD3, the capacitor C9 starts charging, and the terminal voltage exceeds the threshold voltage of the switch means Q3. Then, the switch means Q3 is turned on. As a result, the Zener diode ZD21 becomes conductive, the gate and source of the second switching means Q2 are short-circuited, and the second switching means Q2 is turned on.
2 turns off. Therefore, the high-frequency inverter HFI stops operating, and the application of the high secondary no-load voltage to the load DL is stopped.

<Regarding the Load DL> FIG. 8 is a sectional view showing the arc tube of the high-pressure discharge lamp in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

FIG. 9 is a sectional front view of a main part showing a bulb-type high-pressure discharge lamp as one embodiment of the lighting device of the present invention.

In each of the figures, the high-pressure discharge lamp 12 includes an arc tube IB, a first connection conductor CC1, and a second connection conductor CC1.
2. It comprises a metal coil CO, an outer tube OB and a pair of external connection terminals OCT1 and OCT2.

The bulb-type high-pressure discharge lamp includes a high-pressure discharge lamp 12, a pedestal 13, a reflecting mirror 14, and a lighting circuit means 1.
5, a base 16 and a base 17 are provided.

Hereinafter, the high-pressure discharge lamp 12 and the bulb-type high-pressure discharge lamp will be described for each component.

<Regarding the High Pressure Discharge Lamp 12> (Regarding the Arc Tube IB) The arc tube IB is composed of a transparent ceramic discharge vessel 1, first and second electrodes 2A and 2B, an introduction conductor 3 and a seal 4 Symmetrical structure,
A discharge medium is sealed in the translucent ceramics discharge vessel 1.

The translucent ceramics discharge vessel 1 has an enclosing portion 1a and a pair of diameter cylindrical portions 1b and 1b. The surrounding portion 1a has both ends narrowed by a continuous curved surface,
It is almost spherical. The small-diameter cylindrical portion 1b is connected to the surrounding portion 1a by a continuous curved surface to form the translucent ceramics discharge vessel 1 by integral molding. Each of the first and second electrodes 2A and 2B is made of doped tungsten, has a rod shape, and has a tip protruding into the surrounding portion 1a and being inserted into the small-diameter cylindrical portion 1b.
And a slight gap g between the first and second electrodes 2A and 2B. The introduction conductor 3 is made of niobium, has a rod shape, and has electrodes 2A, 2A at its tip.
B is discharge-welded to the base end portion, and the base end protrudes outside the translucent ceramics discharge vessel 1.

The seal 4 is formed by melting and solidifying the ceramic sealing compound so as to be interposed between the small-diameter cylindrical portion 1b of the translucent ceramic discharge vessel 1 and the introduction body 3, And the introduction conductor 3 is made of a transparent ceramic discharge vessel 1
Is covered so as not to be exposed inside. Further, the electrodes 2A and 2B are fixed at predetermined positions by this sealing. To form the seal 4, the translucent ceramics discharge vessel 1 is set in a vertical position, and a ceramic sealing compound is applied to the end face of the small-diameter cylindrical portion 1 b around a portion protruding outside the introduction conductor 3. And heat and melt to enter the gap between the introducing conductor 3 and the inner surface of the small-diameter cylindrical portion 1b to cover the entirety of the introducing conductor 3 inserted into the small-diameter cylindrical portion 1b. The part is also covered and solidified by cooling.

The discharge medium is composed of a starting gas and a buffer gas containing neon and argon, a metal halide as a luminescent metal, and mercury as a buffer vapor, and is enclosed in a translucent ceramic discharge vessel 1. In addition, since the metal halide and mercury are sealed more than the amount that evaporates, a part 5 of the metal halide and the mercury remain in a small gap g in a liquid state during stable lighting. The interface of the discharge medium forms the coolest part.

(First and second connection conductors CC1, CC
2) As shown in FIG. 9, the first connection conductor CC1
Is formed of a molybdenum wire, the tip of which is connected to the introduction conductor 3 on the electrode 2A side, and the middle extends substantially parallel to and apart from the axial direction of the translucent ceramics discharge vessel 1. The second connection conductor CC2 is made of molybdenum,
The tip is connected to the introduction conductor 3 on the electrode 2B side.

(Regarding Metal Coil CO) The metal coil CO is wound around the outer periphery of the small-diameter cylindrical portion 1b through which the second electrode 2B is inserted, and the coil on the introduction conductor 3 side. The terminal ends extend in a direction perpendicular to the axis of the translucent ceramics discharge vessel 1, and the first connection conductor C
Connected to C1.

(Regarding Outer Tube OB) The outer tube OB is made of a T-shaped bulb made of hard glass and has a pinch seal portion p at the base end.
s is distal to the exhaust tip-off portion t is formed respectively, inside is evacuated 10 ^- it has a low vacuum of about ⁴ torr. The pinch seal portion ps is formed by heating the open end of the T-shaped valve and pinching it in a softened state. The exhaust tip-off portion t is a mark obtained by exhausting the inside of the outer tube OB after sealing the outer tube OB and completely closing the exhaust tube (not shown).

(A pair of external connection terminals OCT1, OCT2)
About) a pair of external connection terminals OCT1 and OCT2
The first and second connection conductors CC1 and CC2 are formed integrally with the first and second connection conductors by extending them, and protrude outward from the outer tube OB as they are before the base B, which is a power receiving means, is attached.

<Regarding Light Bulb-Type High-Pressure Discharge Lamp> (Regarding High-Pressure Discharge Lamp 12)
Is as described above.

(Regarding the pedestal 13) The pedestal 13 is formed by molding a heat-resistant synthetic resin.
In the figure, a mounting portion 13b is provided on an upper outer peripheral edge, and a hollow cup-shaped skirt portion 13c is provided on a lower outer peripheral edge. The mounting hole 13a is for mounting the high-pressure discharge lamp 12 and the reflecting mirror 14, and the pinch seal portion ps of the high-pressure discharge lamp 12 inserted therein and the reflecting mirror 14 to be described later.
Are fixed via an inorganic adhesive BC with the edge 14a of the same being concentric. The mounting portion 13b is fixed to an opening end of the base 16 described later. The skirt portion 13c surrounds and protects the periphery of the reflecting mirror 14, and has an external appearance.

(Reflection Mirror 14) The reflection mirror 14 is disposed around the high-pressure discharge lamp 12, and at least the light emitting portion, that is, the surrounding portion 1 of the high-pressure discharge lamp 12 is provided.
a. The reflecting mirror 14 is fixed to the base 13. In the present embodiment, as described above, it is fixed together with the high-pressure discharge lamp 12.

The reflecting mirror 14 is formed into a cup-like shape by glass molding, and at the same time, a cylindrical edge 14a at the top is integrally formed, and a reflecting surface 14b made of an aluminum vapor-deposited film is formed on the inner surface. are doing. The edge portion 14a is inserted into the mounting hole 13a of the pedestal 13, and is fixed to the pedestal 13 with the inorganic adhesive BC. Further, a front glass 14c is provided in the opening of the reflecting mirror 13.
The front surface 14b is manufactured by molding transparent glass, and is hermetically sealed to the reflecting mirror 14 with a low melting point frit glass 18. Further, nitrogen is sealed as an inert gas in an internal space formed by the reflecting mirror 14 and the front glass 14b.

(Regarding Lighting Circuit Means 15) The lighting circuit means 15 is mounted mainly on the upper side of the wiring board 15a in FIG. 9, and receives the external connection terminals OCT1 and OCT2 of the high pressure discharge lamp 12 from the lower surface of the wiring board 15a. And the wiring board 15a as required. The lighting circuit means 15 has the same circuit configuration as in FIG.

(Regarding the Substrate 16) The substrate 16 has a cup shape, and a base 17 to be described later is attached to the base thereof.
A peripheral step 16a is formed at the opening edge. The lighting circuit means 15 is housed inside the base 16. Further, the peripheral step 13c of the pedestal 13 is fitted to the peripheral step 16a of the opening edge, and is fixed by an adhesive. A hole for venting air or radiating heat is formed at an appropriate position of the base 16 or at a fitting portion with the pedestal as necessary.

(About the base 17) The base 17 is E26
The base 16 is mounted on the base of the base 16.

FIG. 10 is a circuit diagram showing a high-frequency power supply device and a discharge lamp lighting device according to a second embodiment of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the present embodiment, an overcurrent fuse f is provided, and the second switching resonance circuit SRC2, the operating frequency sweep circuit SFC, and the oscillation stop circuit OSC are modified.

The overcurrent fuse f is formed by a pattern fuse integrally formed on a wiring board on which circuit components of the discharge lamp lighting device are mounted. When the low-frequency AC input current becomes overcurrent, the circuit is blown and the circuit is blown. Protect from burning.

The second switching resonance circuit SRC2 is
A capacitor C11 is connected in parallel with a series circuit of the capacitor C6 and the conduction control means CC. Capacitor C1
1 is always connected to the inductive reactance XL2 together with the input capacitance of the second switching means Q2, and adjusts the resonance frequency of the second switching resonance circuit SRC2 when the capacitor C6 is open, as required. .

The operating frequency sweep circuit SFC operates so that the terminal voltage of the resistor R4 of the time constant circuit TC composed of a series circuit of the diode D2, the resistor R4 and the capacitor C9 is applied between the gate and the source of the conduction control means CC. Is configured. Therefore, when the high-frequency inverter HFI is activated, the operating frequency is swept from a low frequency to a high frequency.

The oscillation stop circuit OSC has a capacitor C12 charged by the divided output of the diode D1. As a result, the divided output voltage can be satisfactorily smoothed, and the start time and the duration of the oscillation stop can be further lengthened.

[0149]

According to the first to seventh aspects of the present invention, the load circuit includes at least the first and second reactances constituting the load resonance circuit, and connects the load to one of the reactances in parallel. A high frequency is supplied from the high frequency inverter, and operating frequency sweep control means for sweeping the operating frequency within a predetermined range when the high frequency inverter is started is provided, so that the high frequency inverter is applied to the load as the operating frequency is swept. Since the applied high-frequency voltage changes and a secondary open-circuit voltage that is higher than the voltage applied in a steady state is applied, it is possible to provide a high-frequency power supply device that can easily start the load.

According to the second aspect of the present invention, in addition, the operating frequency control means sweeps the operating frequency in a frequency range including and including the resonance frequency of the load resonance circuit, thereby enabling a simple circuit configuration. It is possible to provide a high-frequency power supply device in which the highest voltage can be generated and applied to the load when the resonance frequency of the load resonance circuit matches the operating frequency during the sweep, and the secondary open-circuit voltage can be easily controlled. it can.

According to the third aspect of the invention, in addition, the inductance of the inductive reactance of the load resonance circuit saturates when there is no load, so that the sweep range of the operating frequency can be narrow to generate a desired high voltage. Therefore, it is possible to provide a high-frequency power supply device whose circuit configuration can be simplified.

According to the fourth aspect of the present invention, the operating frequency sweep control means sweeps the operating frequency from a higher frequency to a lower frequency. The maximum voltage can be generated and applied to the load when
With the configuration in which the inductance of the inductive reactance of the load resonance circuit saturates when there is no load, it is possible to provide a high-frequency power supply that transitions to a steady state in the slow switching region at the end of the frequency sweep.

According to the fifth aspect of the present invention, the operating frequency sweep control means sweeps the operating frequency from a low frequency to a high frequency, so that the resonance frequency and the operating frequency of the load resonance circuit are not changed during the sweep. The maximum voltage can be generated and applied to the load when
Since the inductance of the inductive reactance of the load resonance circuit saturates when there is no load, the resonance frequency and the operation frequency of the load resonance circuit change in the same direction to generate a high voltage for a relatively long time. Can be provided.

According to the sixth aspect of the present invention, since the high-frequency inverter is a half-bridge type inverter, the circuit configuration is simple and the number of circuit components is small. Can be provided.

According to the seventh aspect of the present invention, in addition to the above, the synchronous winding in which the high frequency inverter is magnetically coupled to the inductive reactance of the load resonance circuit, and the voltage induced in the synchronous winding resonates to switch the switching means of the inverter. By providing the switching resonance circuit that determines the frequency, it is possible to provide a high-frequency power supply device including a self-excited high-frequency inverter with a simple circuit configuration and easy switching control.

According to the invention of claim 8, a discharge lamp lighting device having the effects of claims 1 to 7 can be provided.

According to the ninth aspect of the present invention, it is possible to provide a discharge lamp lighting device including a discharge lamp including a high-pressure discharge lamp.

According to the tenth aspect, it is possible to provide a lighting device having the effects of the first to seventh aspects.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a high-frequency power supply device and a discharge lamp lighting device of the present invention.

FIG. 2 is a waveform diagram illustrating changes in voltage and frequency of each part in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

FIG. 3 is a graph showing a resonance characteristic curve of the load resonance circuit at the time of no load in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

FIG. 4 is a graph showing the relationship between the secondary open-circuit voltage and the drain current flowing through the second switching means at the time of starting the sweep of the operating frequency under no load in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention. Waveform diagram shown

FIG. 5 is a diagram showing the secondary open-circuit voltage and the drain current flowing through the second switching means at the time of no load and at the resonance frequency of the load resonance circuit in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention. Waveform diagram showing

FIG. 6 shows the secondary open-circuit voltage and the drain current flowing through the second switching means at the time of no load and at the end of the operating frequency sweep in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention. Waveform diagram shown

FIG. 7 is a graph showing resonance characteristics curves of the load resonance circuit in the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention when no load is applied and when a load is applied

FIG. 8 is a sectional view showing an arc tube of a high-pressure discharge lamp according to the first embodiment of the high-frequency power supply device and the discharge lamp lighting device of the present invention.

FIG. 9 is a cross-sectional front view of a main part showing a bulb-type fluorescent lamp as one embodiment of the lighting device of the present invention.

FIG. 10 is a circuit diagram showing a high-frequency power supply device and a discharge lamp lighting device according to a second embodiment of the present invention.

[Explanation of symbols]

AS: Low frequency AC power supply NF: Noise filter L1: Inductor C1: Capacitor RDC: Rectified DC power supply BRC: Bridge type full-wave rectifier circuit R1: Rush current suppression resistor C2: Smoothing capacitor HFI: High frequency inverter Q1: First Switching means Q2 Second switching means ST Starting circuit DC1 First drive circuit SW1 Synchronous winding SRC1 First switching resonance circuit X _L1 Inductive reactance DP1 First drive protection circuit DC2 First 2 drive circuit SW2 ... synchronous winding SRC2 ... second switching resonant circuit X _{L2 ...} inductive reactance DP2 ... second drive protection circuit LC ... load circuit LRC ... load resonance circuit X L _... first reactance X _C ... Second reactance C7: DC cut capacitor DL Load FSC ... operating frequency control means CC ... conduction control unit TC ... time constant circuit OSC ... oscillation control unit Q3 ... switching means VD ... voltage divider ZD3 ... reference voltage element

Claims (10)

[Claims] 1. A load circuit including at least a first reactance and a second reactance constituting a load resonance circuit, and connecting a load in parallel to one of the reactances; a DC power supply; and switching means. A high frequency inverter that converts a direct current input from a direct current power supply into a high frequency and supplies the high frequency inverter to a load circuit; and an operating frequency sweep control unit that sweeps the operating frequency of the high frequency inverter within a predetermined range when the high frequency inverter is started. A high-frequency power supply device. 2. The high frequency device according to claim 1, wherein the operating frequency sweep control means sweeps the operating frequency in a frequency range including and including the resonance frequency of the load resonance circuit when the load circuit is not loaded. Power supply. 3. The high-frequency power supply device according to claim 1, wherein the inductance of the inductive reactance constituting one reactance of the load resonance circuit saturates when there is no load. 4. The high frequency power supply according to claim 2, wherein the operating frequency sweep control means sweeps the operating frequency from a high frequency to a low frequency. 5. The high-frequency power supply according to claim 2, wherein the operating frequency sweep control means sweeps the operating frequency from a low frequency to a high frequency. 6. The high-frequency inverter is a half-bridge type inverter including first and second switching means connected in series and alternately switched by applying a DC input voltage between both ends; the load circuit includes a high-frequency inverter. The high-frequency power supply device according to any one of claims 1 to 5, wherein the high-frequency power supply device is connected in parallel to the second switching means. 7. A high-frequency inverter, wherein a synchronous winding magnetically coupled to an inductive reactance of the first and second reactances of the load circuit, and a voltage induced in the synchronous winding is applied to exhibit resonance. 7. The high-frequency power supply device according to claim 1, further comprising a switching resonance circuit that determines a switching frequency of the switching means. 8. A discharge lamp lighting device comprising: the high-frequency power supply device according to claim 1; and a discharge lamp connected as a load to a load circuit of the high-frequency power supply device. apparatus. 9. The discharge lamp lighting device according to claim 8, wherein the discharge lamp is a high pressure discharge lamp. 10. A lighting device, comprising: a lighting device main body; and the discharge lamp lighting device according to claim 8 supported by the lighting device main body.