JP2003173890A - Discharge lamp lighting device and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device with simple circuit construction, which is easy to mount, suitable for miniaturization by using a small wiring board, and controlling the discharge lamp in optimum operating state corresponding to the temperature affected by the lighting of the discharge lamp, and to provide a luminaire using the same. <P>SOLUTION: The discharge lamp lighting device comprises switching means Q1, Q2; a load circuit LC having a resonance inductance L2 and a resonance capacitor C4 connected in parallel with the discharge lamp; a drive resonance circuit DRC composed of a feed-back winding s feeding back a current flowing through the load circuit LC, and a drive resonance inductance and a drive resonance static capacitor C5, constructed so that at least either the drive resonance inductance or the drive resonance static capacitor changes its constant corresponding with the change of temperature due to the lighting of the discharge lamp, and resonating to a feed-back voltage generated at the feed-back winding s; and a feed-back type driving signal generating circuit DSG alternately turning on the switching means Q1, Q2 depending on the resonance voltage of the drive resonance circuit DRC. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device having a half-bridge type inverter and a lighting device using the same.

[0002]

2. Description of the Related Art In a discharge lamp lighting device having a half-bridge type inverter, it has already been performed to feed back a current flowing in a load circuit to form a drive signal for a switching element by self-excited oscillation. This discharge lamp lighting device has an advantage that the circuit configuration is relatively simple and can be easily miniaturized, and is also used for a compact fluorescent lamp that is strongly required to be miniaturized.

Japanese Patent No. 3126265 discloses a holder having a recess, a double U-shaped fluorescent tube having both ends fixed to the holder, a lighting circuit having a current transformer, a case accommodating the lighting circuit, and the fluorescent light. The lighting circuit includes a globe that houses a tube and forms an envelope with the case, and the lighting circuit has a characteristic that the input power to the fluorescent tube decreases as the temperature of the core of the current transformer rises. A compact fluorescent lamp (prior art 1) is characterized in that a bent portion adjacent to the holder is fixedly held on the holder and the current transformer is provided adjacent to the recess. Have been described.

In Japanese Patent Laid-Open No. 2001-338790, a DC power supply; first switching means and second switching means connected in series between the DC power supplies; at least resonance inductance and resonance capacitance A load circuit that includes: a discharge circuit that is operated by high-frequency alternating current generated by alternate switching of the first and second switching means, and that a discharge lamp is connected in parallel to at least a part of the resonance capacitance; A feedback winding that returns the flowing current, a drive resonance circuit that resonates with the feedback voltage generated in the feedback winding, and a temperature-sensitive resistor that continuously changes the resonance frequency of the drive resonance circuit at least when the power is turned on by connecting to the drive resonance circuit. And switching the first and second switching means based on the resonance voltage of the drive resonance circuit. A feedback type drive signal generating circuit that turns on control; discharge lamp lighting apparatus, characterized in that it comprises a (prior art 2) is described.

[0005]

In prior art 1, it is necessary to give saturable characteristics to the current transformer in order to switch the base drive current for the transistor when the load current is fed back, so that the current transformer is saturable. The thing provided with the ring core which has a characteristic is used.
In the case of such a current lance, not only is it extremely difficult to wind the winding, but also the variation in the characteristics is large, which makes the design difficult and increases the cost, and the current transformer becomes large in size. There is a problem.

Next, in the prior art 2, in order to equivalently reduce the electrostatic capacitance of the drive resonance circuit of the feedback type drive signal generating circuit, a temperature sensitive resistor is connected to the resonance circuit.
Along with this, it is necessary to divide the electrostatic capacitance of the drive resonance circuit into a plurality of pieces so as to have a parallel or series connection relationship. Therefore, the temperature sensitive resistor is also added to increase the number of constituent circuit components, and the mounting thereof becomes troublesome. Further, since the wiring board becomes large, there is a problem that the discharge lamp lighting device becomes large in size.

The present invention has a simple circuit configuration, is easy to mount, and is suitable for downsizing of the device by using a small wiring board. Moreover, the optimum operating state is obtained in response to the temperature accompanying the lighting of the discharge lamp. An object of the present invention is to provide a controlled discharge lamp lighting device and a lighting device using the same.

[0008]

According to another aspect of the present invention, there is provided a discharge lamp lighting device including: a DC power supply; first switching means and second switching means connected in series between the DC power supplies; at least resonance. A load including an inductance and a resonance capacitance, operated by a high-frequency alternating current generated by alternating switching of the first and second switching means, and a discharge lamp connected in parallel to at least a part of the resonance capacitance. A circuit; a feedback winding that feeds back a current flowing in a load circuit, and a drive resonance inductance and a drive resonance capacitance, at least one of which changes its constant in response to a temperature change associated with lighting of a discharge lamp of the load circuit. And a drive resonance circuit that resonates with the feedback voltage generated in the feedback winding. A feedback type drive signal generation circuit for turning on controlling the first and second switching means on the basis of the resonance voltage of the drive resonant circuit alternately; is characterized in that it comprises a.

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

<About DC Power Supply> The DC power supply may be either a rectified DC power supply that rectifies AC or 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,
You may use the active filter which operates using the 1st and 2nd switching means mentioned later, for example, a partial smoothing circuit.

<Regarding First and Second Switching Means> The first and second switching means are MO
Voltage control type switching means such as SFET or current control type switching means such as bipolar transistor can be used.

Since the FET is a voltage control type switching means, it is easy to control. Also MOSFET
Is effective as a switching means for electric power, which is less restricted by the safe operation area. Further, the enhancement type MOSFET is easy to process when the power is turned on and is suitable as a switching means for electric power. Furthermore, N
Channel type MOSFETs are advantageous because they currently have a rich product lineup. However, if necessary, P
A channel type MOSFET can be used. Also, one of them is an N-channel MOSFET,
The other may be a P-channel MOSFET.

By the way, the switching means has a drive terminal and is driven, that is, turned on, when a drive signal having 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 and turned on. Therefore, the OFF state is maintained in the state where the gate voltage is not applied.

"Connecting the first and second switching means in series between the DC power supplies" means that the first and second switching means are in a series connection relationship when viewed from the DC power supply. Other circuit components such as a resistor may be interposed between the first and second switching means and the DC power supply. Also, a circuit component may be interposed between the first and second switching means.

<Regarding Load Circuit> The load circuit has at least a resonance inductance and a resonance capacitance. And it operates by the alternating current generated by the alternating switching of the first and second switching means. The discharge lamp of the load is connected in parallel to at least a part of the capacitance of the load circuit.

The resonant inductance and the resonant capacitance can resonate with the alternating current generated by the alternating switching of the first and second switching means. The resonance inductance and the resonance capacitance are at least 1 each.
Each of them is connected to the load circuit, and one or both of them are allowed to be composed of a plurality, if necessary.

Further, the resonance inductance acts so as to compensate for the negative characteristic of the discharge lamp of the load.

Further, when the resonance capacitance is composed of a plurality of capacitors, a part of them can act as a DC cut capacitor, and at least a part of the rest can act as a resonance voltage extracting capacitor. . The discharge lamps can be connected in parallel so that the resonance voltage appearing across the resonance voltage extracting capacitor is applied to the discharge lamp.

When the discharge lamp is a low-pressure discharge lamp such as a fluorescent lamp and the filament electrode is used, and when the discharge lamp is started by using the filament electrode as a hot cathode, a method of heating the filament electrode at the time of starting is as follows. There are two types shown below.

The first is to connect a resonance capacitance in parallel with the discharge lamp via at least one filament electrode at the time of starting. Then, at the time of start-up, a current flows through the resonance inductance and the resonance capacitance to the filament of the electrode, so that the filament is heated. At the same time, the resonance inductance and the resonance electrostatic capacitance properly resonate in series, and the terminal voltage of the resonance electrostatic capacitance increases, so that the starting of the discharge lamp is promoted.

The second method is to heat the filament electrode using a filament heating transformer. The filament heating transformer may be provided separately from the resonance inductance, but if necessary, the filament heating winding can be magnetically coupled to the resonance inductance. Then, the increase in the number of circuit components can be suppressed.

<Feedback type drive signal generating circuit>
The feedback drive signal generation circuit is configured to include a feedback winding and a drive resonance circuit. The feedback winding is
It is a circuit that feeds back a current flowing in a load circuit to generate and supply a drive signal to the first and second switching means. Therefore, the discharge lamp lighting device of the present invention constitutes a self-excited half-bridge inverter.
The drive resonance circuit has a drive resonance inductance and a drive resonance capacitance, and one or both of the drive resonance inductance and the drive resonance capacitance are sensitive to a temperature change caused by lighting of a discharge lamp of the load circuit. The constant is changed. In addition to the above configuration, the feedback drive signal generating circuit includes a supply circuit for alternately supplying drive signals to the first and second switching means, and the first and second switching circuits. A drive protection circuit can be added to prevent the device from being destroyed by being supplied with an excessive drive signal. The configuration of each part of the feedback drive signal generating circuit will be described in more detail below.

(Feedback Winding) In order to feed back the current flowing in the load circuit, the feedback winding is magnetically coupled to the resonance inductance of the load circuit or has an independent feedback transformer inserted in series with the resonance inductance. Or it can be arranged. When magnetically coupling the feedback winding to the resonance inductance, it is common to provide an air gap in the magnetic circuit. Care must be taken in the winding position of the feedback winding on the magnetic circuit to obtain the desired characteristics. When an independent feedback transformer is inserted, its secondary winding constitutes a feedback winding. The feedback transformer may have a saturable configuration or an unsaturated configuration. However, it should be noted that the saturable structure is difficult to wind and has a large variation in characteristics, resulting in a large size. On the other hand, the unsaturated configuration is superior to the other configurations and will be described in detail below.

If a feedback transformer with an unsaturated configuration is used, this transformer comprises at least a primary winding and a secondary or feedback winding, and the current flowing in the load circuit in order to drive the switching means. To induce a voltage in the secondary winding that is proportional to Therefore, the number of turns on the primary winding side is relatively small, and therefore the inductance of the primary winding is small and does not substantially contribute as a resonance inductance. The "unsaturated configuration" means a configuration in which a core configured to substantially prevent magnetic saturation is used or a configuration formed without using the core.
Furthermore, "the core is configured so as not to be saturated" means that the core has a substantially infinite void length, such as a drum core or a rod core.
A core having such characteristics can be realized by a drum core or a rod core.

The relationship between the primary winding and the secondary winding is
Not only the primary winding may be superposed on the secondary winding, but on the contrary, the secondary winding may be superposed on the primary winding. Further, the primary winding and the secondary winding of the feedback transformer having the unsaturated configuration may be wound not only in the lap winding but also adjacently.
In this case, a reel can be used. Furthermore, the secondary winding allows for single or multiple windings. For example, one secondary winding may be allocated to each of the first and second switching means, and a drive resonance circuit and a drive protection circuit may be further arranged. However, even when a pair of secondary windings are arranged, if a drive resonance circuit is formed by connecting a capacitance to only one of the secondary windings, the other secondary winding can be formed. Also induces resonance output, so drive resonance circuit etc.
It is not necessary to provide one.

(About Drive Resonance Circuit) The drive resonance circuit is composed of a drive resonance inductance and a drive resonance capacitance. When the secondary winding of the unsaturated transformer is used as the feedback winding, the inductance seen from the secondary winding side can be used as the drive resonance inductance. When a feedback winding is magnetically coupled to the resonance inductance of the load circuit to form a feedback transformer, the inductance seen from the secondary winding side can be used in the same way as above, but a choke coil type is provided separately. Inductance such as may be used as the drive resonance inductance. The resonance circuit may be connected in either a parallel resonance circuit or a series resonance circuit.

When the drive resonance inductance is used so that the constant, that is, the inductance changes in response to the temperature change accompanying the lighting of the discharge lamp of the load circuit, when the temperature reaches a predetermined temperature as the core of the inductance, the magnetic It is possible to use a temperature-sensitive inductor whose characteristics change and, as a result, the inductance decreases.

The drive resonance capacitance can use a capacitor or the capacitance of the switching means, for example, the gate-source capacitance of the MOSFET. However, when the drive resonance capacitance is configured so that the constant, that is, the inductance changes in response to the temperature change accompanying the lighting of the discharge lamp of the load circuit, when the capacitance reaches a predetermined temperature, the dielectric It is possible to use a temperature-sensitive capacitor whose characteristics change and, as a result, the capacitance decreases.

(Regarding Temperature Sensitive Characteristics) The predetermined temperature when the temperature sensitive inductor or the temperature sensitive capacitor is used is set according to the operation mode to be optimized for the discharge lamp. The operation modes to be optimized include, for example, abnormal discharge protection, improvement of luminous flux rise in the initial lighting,
Also, it is possible to deal with the ambient temperature during lighting, compensation of power supply voltage fluctuation, and the like, and it is only necessary to set a predetermined temperature suitable for each.

Further, in order to operate the temperature-sensitive inductor and the temperature-sensitive capacitor in a temperature-sensitive manner, these circuit components are arranged at positions where the temperature of the discharge lamp can be directly or indirectly sensed. In order to increase the sensitivity of temperature-sensitive operation, it is desirable to place them at the position where the temperature rise is the highest in the operation mode to be optimized, but the temperature rise is always the highest in consideration of the mounting of circuit parts. It does not have to be arranged at the position.

(About Drive Circuit) The drive circuit is means for supplying the drive signal formed based on the drive resonance voltage generated in the drive resonance circuit to the first and second switching means. The drive resonance circuit can generate resonance outputs of positive and negative polarities by resonance and supply the resonance outputs to the first and second switching means. When the first and second switching means have the same polarity, the switching means are alternately turned on,
In order to turn it off, when the resonance output of the drive resonance circuit is supplied to one switching device with a certain polarity, the other switching device is supplied with the polarity inverted. For this purpose, the polarity can be easily reversed by using a transformer, for example. On the other hand, when the first and second switching means have a complementary relationship, the resonance output of the drive resonance circuit can be directly supplied to both switching means without inverting the polarities. When the first and second switching means are of the voltage drive type, the drive circuit is configured to supply the drive voltage and is connected to the control end of the switching means via the coupling capacitor. be able to. If it is a current drive type, it is configured to supply a drive current.

When the voltage drive type switching means is used, a voltage clamp circuit can be added as a drive protection circuit, if necessary, in order to regulate the drive signal to a voltage of a predetermined value. The drive protection circuit is the first
And to prevent an excessive voltage from being applied to the drive terminal of the second switching means, and any specific circuit configuration may be used. For example, a drive protection circuit can be configured by connecting at least two Zener diodes in series with opposite polarities. The drive protection circuit can protect the resonance voltage of both positive and negative polarities. Also, when using complementary switching means, one drive protection circuit is the first
Also, the gate protection action is exerted on both the second switching means. Further, the drive protection circuit can be configured by various similar circuit configurations as long as it is a constant voltage element, instead of the Zener diode. Furthermore, the number of constant voltage elements used may be determined by the relationship between the constant voltage and the gate voltage.

Thus, the voltage component that causes an overvoltage to the gate of the switching means is short-circuited and absorbed by the drive protection circuit, so that the gates of the first and second switching means have appropriate values. Only voltage is applied. If an overvoltage is applied to the switching means, it may damage the switching means, so it is preferable to add a drive protection circuit.

<Other Configurations> Although not an essential component of the present invention, a suitable starting circuit can be attached to start the half-bridge inverter. For example, a voltage dividing circuit for the DC power supply voltage, which mainly includes a resistor, may be configured to divide the DC power supply voltage at the control end of the first switching means so that a predetermined drive voltage is applied. Further, a predetermined drive voltage may be applied from the DC power supply to the control terminal of the first switching means by a circuit mainly composed of the time constant circuit and the trigger element.

When a rectified DC power supply is used as the DC power supply, a noise filter is provided in the low frequency AC power supply and the AC input of the rectifier circuit so that high frequency noise due to the switching of the first and second switching means does not flow into the low frequency AC power supply. Can be inserted between the ends.

<Regarding Operation of the Present Invention> In the present invention, a half-bridge type inverter that flows into a load circuit is configured by alternate switching of the first and second switching means, and a discharge lamp that is a load is attached by its high-frequency alternating current. While being energized, the negative characteristic is compensated by at least a part of the resonance inductance, and stable lighting is performed. Then, the high frequency alternating current flowing through the load circuit is fed back to the feedback type drive signal generating circuit. When a feedback voltage is generated in the feedback type drive signal generating circuit, the dry self-oscillates in the feedback voltage and a high frequency voltage is continuously generated. The drive resonance circuit resonates, and based on the drive resonance voltage, the first
Since the drive signals are alternately supplied to the second switching means and the second switching means, the half-bridge inverter performs the self-excited oscillation operation to continuously generate the high frequency voltage.

By the way, in the present invention, the drive resonance circuit of the feedback drive signal generating circuit is provided with the drive resonance inductance and the drive resonance electrostatic capacitance, and at least one of them is the discharge lamp of the load circuit. Since the constant is changed in response to the temperature change caused by lighting, feedback control of high-frequency power supply to the discharge lamp is performed according to the temperature of the discharge lamp in a desired operation mode of the discharge lamp. The operation mode of the discharge lamp includes, for example, abnormal discharge protection,
It is possible to select the improvement of the rising of the luminous flux at the initial stage of lighting and compensation for fluctuations in ambient temperature and power supply voltage during lighting.
The temperature feedback control in each operation mode will be described below.

(Abnormal discharge protection operation) When the discharge lamp has a half-wave discharge at the end of its life or an abnormal discharge such as abnormal heating of the filament electrode, the discharge lamp is
Since the temperature rises to 50 ° C. or higher, the drive resonance inductance or the drive resonance capacitance of the drive resonance circuit rises in temperature in response to the above temperature, and its constant, that is, the inductance or the capacitance changes, for example, decreases. Therefore, the resonance frequency increases.

Generally, the half-bridge type inverter is designed to operate in a frequency range higher than the resonance frequency of the load circuit in order to cause the first and second switching means to perform the lag switching. Therefore, when an abnormal discharge occurs and the drive resonance frequency rises from that during normal operation, the operating point moves to a region where the resonance characteristic curve of the load circuit is lower. As a result, the high-frequency output voltage is lowered, so that the discharge lamp cannot sustain the discharge and disappears, thereby ensuring safety.

(Improving luminous flux rise at the initial stage of lighting) In order to improve the luminous flux rise at the initial stage of lighting, the drive resonance inductance or the drive resonance capacitance of the drive resonance circuit is sensitive to the temperature of the discharge lamp. , The drive resonance circuit resonates in a region relatively close to the resonance frequency of the resonance circuit of the load circuit at a low temperature in the initial stage of lighting, for example, when the discharge lamp transitions from glow discharge to arc discharge, and the drive resonance frequency increases due to temperature rise. Design to be high. By doing so, high-power operation is performed at the initial stage of lighting to accelerate the rise of the luminous flux, and when the normal lighting state is achieved, the rated load operation is started.

(Compensation for ambient temperature and power supply voltage fluctuation during lighting) When compensating for ambient temperature and power supply voltage fluctuation during lighting, the drive resonance inductance of the drive resonance circuit and / or the drive resonance electrostatic capacity of the discharge lamp By sensing the temperature, when the ambient temperature or the power supply voltage fluctuates excessively, the drive resonance frequency or the constant of the drive resonance capacitance changes and the drive resonance frequency changes. It is configured so that feedback control is performed. Then, the light output is reduced and maintained substantially constant.

Further, in the present invention, in the drive resonance circuit, at least one of the drive resonance inductance and the drive resonance electrostatic capacitance changes the constant in response to the temperature change accompanying the lighting of the discharge lamp. It is not necessary to connect a temperature-sensitive resistance element in addition to the above-mentioned essential circuit element or to divide the above-mentioned resonance circuit element essential for drive resonance into a divided structure. Therefore, the circuit configuration of the drive resonance circuit is simplified and the number of constituent circuit components is small, so that the drive resonance circuit is easy to mount and a small wiring board is sufficient, which is suitable for downsizing the discharge lamp lighting device.
In particular, when the present invention is applied to an electric bulb type fluorescent lamp whose downsizing is strictly pursued, it is extremely effective.

The discharge lamp lighting device according to the invention of claim 2 is
In the discharge lamp lighting device according to claim 1, the feedback winding is formed by a secondary winding of an unsaturated transformer in which the primary winding is connected in series to the load circuit.

According to the present invention, since the primary winding of the unsaturated transformer is provided separately from the resonance inductance of the load circuit, a high voltage due to the resonance of the load circuit is not applied. High reliability can be obtained without applying high dielectric strength. Further, the winding can be formed easily, the cost can be reduced, and the variation in characteristics is small, and the design is relatively easy. Further, the unsaturated transformer is relatively easy to miniaturize.

The discharge lamp lighting device according to the invention of claim 3 is
The discharge lamp lighting device according to claim 1, wherein the feedback winding is magnetically coupled to at least a part of the resonance inductance of the load circuit.

Since the present invention has the above structure, the circuit structure is simplified.

The discharge lamp lighting device according to the invention of claim 4 is
The discharge lamp lighting device according to any one of claims 1 to 3, wherein the feedback-type drive generation circuit comprises a temperature-sensitive inductor in which the drive resonance inductance of the drive resonance circuit changes in response to a temperature change. It has a feature.

The inductance of the temperature sensitive inductor changes in response to a temperature change caused by lighting of the discharge lamp. The temperature-sensitive inductor has an inductance due to a change in magnetic permeability of the winding core depending on temperature, and may be a secondary winding of a transformer or a choke coil type inductor. . The sensitive temperature is appropriately selected in consideration of the temperature at which the discharge lamp is mainly controlled and the temperature difference between the temperature at which the drive resonance inductance senses the temperature and the above temperature.

The discharge lamp lighting device according to the invention of claim 5 is
The discharge lamp lighting device according to any one of claims 1 to 3, wherein the feedback drive generation circuit has a temperature-sensitive capacitor whose capacitance changes in response to a change in drive resonance capacitance of the drive resonance circuit. It is characterized by that.

The capacitance of the temperature-sensitive capacitor changes in response to the temperature change caused by lighting of the discharge lamp. Further, the temperature-sensitive capacitor can be obtained by a ceramic-type capacitor in which the dielectric body is made of ceramics whose dielectric constant changes with temperature. The sensitive temperature is appropriately selected in consideration of the temperature at which the discharge lamp is mainly controlled and the temperature difference between the temperature at the portion sensed by the drive resonance capacitor and the above temperature.

The discharge lamp lighting device according to the invention of claim 6 is:
The discharge lamp lighting device according to any one of claims 1 to 5, wherein at least one of a drive resonance inductance and a drive resonance capacitance of the drive resonance circuit is sensitive to a temperature change during abnormal discharge of the discharge lamp. Thus, the operation is performed so that the resonance frequency becomes higher.

The present invention defines a structure suitable for performing a protective operation when the discharge lamp is abnormally discharged. That is, at the time of abnormal discharge such as half-wave discharge, the temperature of the discharge lamp becomes higher than that at the normal time, so that the drive resonance inductance or the drive resonance electrostatic capacitance becomes small in response to the increased temperature. Therefore, the resonance frequency of the drive resonance circuit increases, and as a result, the oscillation frequency of the half-bridge inverter changes, and the frequency of the high frequency output also increases. When the discharge lamp is operating normally, the half-bridge inverter is set to operate in the slow phase region of the resonance characteristics of the load circuit. Since the operating point moves to a smaller portion, the high frequency output voltage becomes smaller. As a result, the discharge of the discharge lamp disappears. Therefore, the protection operation is performed against the abnormal discharge due to the abnormality.

The discharge lamp lighting device according to the invention of claim 7 is
The discharge lamp lighting device according to any one of claims 1 to 5, wherein at least one of a drive resonance inductance and a drive resonance capacitance of the drive resonance circuit is sensitive to a temperature change from the initial lighting of the discharge lamp. And operates so that the resonance frequency becomes higher.

The present invention defines a configuration suitable for accelerating the rise of luminous flux when the discharge lamp is lit. That is, the resonance frequency of the drive resonance circuit is relatively lowered when the discharge lamp is lower than a predetermined temperature, and
The temperature of the discharge lamp is set to be relatively high with respect to the temperature during steady lighting. Along with this, the drive resonance inductance or the drive resonance electrostatic capacitance has a large constant at the low temperature of the discharge lamp.
Also, during steady lighting, the constant changes and becomes smaller. As a result, the half-bridge inverter
When the temperature is low at the beginning of lighting, the operating point is relatively close to the resonance point of the resonance characteristic curve of the load circuit, so the high frequency output voltage becomes higher than that during rated lighting, and the discharge lamp performs high output lighting. . Therefore, the light flux rises quickly. After that, when the temperature of the discharge lamp rises with the passage of time, the operating point moves to a position relatively distant from the resonance point of the resonance characteristic curve of the load circuit. And the discharge lamp lights up in the steady state of rated lighting.

An illumination device according to an eighth aspect of the present invention comprises: an illumination device main body; and the discharge lamp lighting device according to any one of claims 1 to 7, which is supported by the illumination device main body. Oki.

In the present invention, the "lighting device" is a broad concept including all devices that utilize the light emission of a discharge lamp, for example, a lighting device, a backlight device such as a liquid crystal display, and a personal computer or a television set incorporating the same. The information receiver includes various information devices such as a GPS device, an image reading device and a copier incorporating the image reading device, an OA device such as a facsimile and a scanner, and a light bulb type fluorescent lamp.

Particularly, in the present invention, the discharge lamp lighting device can be remarkably miniaturized, so that it is suitable for a compact compact fluorescent lamp. It should be noted that a lighting fixture or the like provided with a bulb-type fluorescent lamp also constitutes the lighting device according to the present invention.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION 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 a discharge lamp lighting device of the present invention. In the figure, AS is a low frequency AC power supply, f is an overcurrent fuse, AS is a surge absorbing element, NF is a noise filter, RD is a rectified DC power supply, Q1 is a first switching means, Q2 is a second switching means, LC is a load circuit, NST is an unsaturated transformer, DRC is a drive resonance circuit, DC is a drive circuit,
ST is a starting circuit.

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

<Regarding Overcurrent Fuse f> The overcurrent fuse f is composed of a pattern fuse integrally formed on the wiring board on which the circuit parts of the power supply device and the discharge lamp lighting device are mounted. When it becomes, protect it from being burnt out by melting.

<Regarding Surge Absorbing Element AS> The surge absorbing element AS is connected in parallel between the low frequency AC power supply lines and absorbs a surge coming from the low frequency AC power supply AS to insulate the discharge lamp lighting device. Protect from destruction.

<Regarding Noise Filter NF> The noise filter NF includes a first portion serially interposed between the low-frequency AC power supply AS and the rectified DC power supply RD, and a rectified DC power supply RD and a first switching device described later. Means Q
It is divided into a second part which is interposed between the two in series.
Then, the first and second switching means Q1, Q2
The high-frequency noise generated by the alternating switching is prevented from flowing out to the low-frequency AC power supply AS side. The noise filter NF includes a capacitor C1 connected in parallel between the low frequency AC power supply lines. The second portion is composed of the inductor L1.

<Regarding Rectified DC Power Supply RD> The rectified DC power supply RD is composed of a bridge type full-wave rectifier circuit BRC and a smoothing capacitor C2. The bridge-type full-wave rectifier circuit BRC has its AC input terminal connected to the low-frequency AC power supply AS and its DC output terminal connected to both ends of the smoothing capacitor C2. The smoothing capacitor C2 is connected between the DC output terminals of the bridge-type full-wave rectifier circuit BRC via the inductor L1 which is the second part of the noise filter NF.

<First and Second Switching Means Q
1. Regarding Q2> First switching means Q1
Is an enhancement type N-channel MOSFET
And its drain is connected to the positive electrode of the rectified DC power supply RD. The second switching means Q2 is also composed of an enhancement P-channel MOSFET, the source thereof is connected to the source of the first switching means Q1, and the drain thereof is connected to the negative electrode of the rectified DC power supply RD. That is, the first and second switching means Q1 and Q2 are connected complementarily to the rectified DC power supply RD. Then, the first and second switching means Q1 and Q2 form a switching circuit of a half-bridge inverter, and are alternately turned on and off to generate high-frequency alternating current.

<Regarding Load Circuit LC> Load Circuit L
In C, a discharge lamp is connected as a load DL to a series circuit of a resonance inductance L2, a DC cut capacitor C3, and a resonance capacitor C4. The DC cut capacitor C3 and the resonance capacitor C4 form the resonance capacitance referred to in the present invention. However, since the capacitance of the DC cut capacitor C3 is relatively large, the resonance capacitor C4 acts predominantly as the resonance capacitance. The resonance inductance L2 has one end connected to one end of the primary winding p of the unsaturated transformer NST and the other end connected to one end of the DC cut capacitor C3.
It provides a current limiting impedance to the discharge lamps that make up the load DL. The other end of the DC cut capacitor C3 is connected to one end of the discharge lamp DL.

In this embodiment, a fluorescent lamp is used as the discharge lamp that constitutes the load DL. The power supply side terminal of one filament electrode E1 of the discharge lamp which is the load DL is connected to the other end of the DC cut capacitor C3, and the power supply side terminal of the other filament electrode E2 is the drain of the second switching means Q2. Connected to.

The resonance capacitor C4 is connected between the non-power supply side terminals of the pair of filament electrodes E1 and E2 of the discharge lamp DL. Then, the load circuit LC forms a series resonance circuit including the resonance inductance L2, the DC cut capacitor C3, and the resonance capacitor C4.

<About feedback type drive signal generating circuit DSG> is composed of an unsaturated transformer NST, a drive resonance circuit DRC, a drive circuit DC and a drive circuit DC.

(Unsaturated Transformer NST) The unsaturated transformer NST is composed of a core CO, a secondary winding, that is, a feedback winding s.
And a primary winding p. The core CO is composed of a drum-shaped ferrite core, and is not saturated because the magnetic path is open. Secondary winding s
Is formed by winding, for example, 270 turns of an insulating coated conductor on the core CO. One end is connected to the sources of the first and second switching means Q1 and Q2. The inductance of the feedback winding s is Ln2. The primary winding p is formed by winding, for example, 10 turns of an insulating coated conductor on the feedback winding s. And
One end is connected to one end of the feedback winding s, that is, the sources of the first and second switching means Q1 and Q2, and the other end is connected to one end of the resonance inductance L1. Therefore,
The primary winding p is inserted in series with the load circuit LC.

(Drive Resonance Circuit DRC) The drive resonance circuit DRC is a feedback winding s of the unsaturated transformer NST.
And a capacitor C5 are connected in parallel to form a series resonance circuit formed by the drive resonance inductance Ln2 of the feedback winding s and the drive resonance capacitance C5. Although the feedback winding s of the unsaturated transformer NST and the drive resonance capacitance C5 are connected in parallel, when the induced voltage of the feedback winding s is viewed as a power source, the equivalent inductance Ln2δ of the feedback winding s There is a series relationship with the drive resonance capacitance C5, and these act as a series resonance circuit.

The drive resonance circuit DRC is so constructed that its drive resonance inductance Ln2 decreases when the temperature accompanying the lighting of the discharge lamp becomes 150 ° C. or higher. The drive resonance inductance Ln2 is 15 when the discharge lamp DL is abnormally discharged.
It is located at a temperature above 0 ° C.

(Drive circuit DC) Drive circuit D
C is composed of a capacitor C6 and a gate protection circuit GP. The capacitance of the capacitor C6 is relatively large, and one end of the capacitor C6 is between the connection point of the secondary winding s of the drive resonance circuit DRC and the capacitor C5 and the gates of the first and second switching means Q1 and Q2. Are inserted in series. The gate protection circuit GP comprises an anti-series circuit of a pair of Zener diodes ZD1 and ZD2, and is connected between the gates of the first and second switching means Q1 and Q2.

<Regarding Start Circuit ST> Start Circuit S
T consists of resistors R1, R2 and R3. Resistor R
1, one end of which is connected to the positive electrode of the rectified DC power supply RD,
The other end is connected to the connection point of the gate of the first switching means Q1 and the capacitor C6 of the drive circuit DC. The resistor R2 is connected in parallel with the capacitor C6. The resistor R3 is connected in parallel between the drain and source of the second switching means Q2. The resistor R
A capacitor C7 is connected in parallel with 3. Therefore, the resistors R1, R2 and R3 are connected to the rectified DC power supply R
It is connected to D in series.

<Regarding Circuit Operation> When the low-frequency AC power supply AS is turned on, the DC voltage smoothed by the rectification DC power supply RD appears across the smoothing capacitor C2. Then, a DC voltage is applied between the drain and source of the first and second switching means Q1 and Q2 connected in series. However, the first and second switching means Q
No gate voltage is applied to 1 and Q2, so that they remain in the off state.

The DC voltage of the rectified DC power supply RD is
At the same time, it is applied to the series circuit of the resistors R1, R2 and R3, and a voltage drop corresponding to each resistance value is generated. As a result, the voltage drop across resistor R2 causes capacitor C6 to
Is charged, and the first and second switching means Q1, through the primary winding p of the unsaturated transformer NST,
It is applied between the gate and source of Q2.

The first switching means Q1 is a resistor R
Since a voltage drop of 2 is applied in the forward direction, a channel is formed and turned on. At this time, the electric charge of the capacitor C6 flows into the gate-source capacitance of the second switching means Q1 and charges it, thereby backing up the ON operation of the first switching means Q1. On the other hand, the second switching means Q2 maintains the OFF state because the voltage drop across the resistor R2 is in the opposite direction.

When the first switching means Q1 is turned on, the drain / source of the first switching means Q1 and the primary winding p of the unsaturated transformer NST are connected in series from the positive electrode of the rectified DC power supply RD. A current flows through the load circuit LC, that is, the resonance inductance L2, the DC cut capacitor C3, the resonance capacitor C4, and the negative electrode path of the rectified DC power supply RD. At this time, the resonance inductance L2 of the load circuit LC, the DC resonance capacitor C3, and the series resonance circuit of the resonance capacitor C4 resonate, and the terminal voltage of the resonance capacitor C4 increases and is charged.

The primary winding p of the unsaturated transformer NST
A current having a waveform proportional to the current waveform is induced in the feedback winding s due to the current flowing through the feedback coil s. This induced voltage is
The terminal without the polarity symbol attached to is high. In addition, the voltage drop of the primary winding p becomes higher at the terminal to which the polarity symbol in the figure is not attached.

On the other hand, the feedback winding s of the unsaturated transformer NST
, The drive resonance inductance Ln2 forms the drive resonance advertising capacitance C5 and the drive resonance circuit DRC, so that the induced voltage in the feedback winding s resonates. Then, as the resonance voltage, a forward voltage is continuously applied between the gate and source of the first switching means Q1 via the capacitor C6 of the drive circuit DC, and the ON state is maintained.

On the other hand, since the resonance voltage is applied in the opposite direction between the gate and the source of the second switching means Q2, the second switching means Q2 remains in the off state. However, the polarity of the resonance voltage of the drive resonance circuit DRC is inverted next due to the vibration due to resonance, and at that time, the first switching means Q is used.
The gate-source voltage of 1 becomes a reverse voltage and turns off, and conversely, the gate-source voltage of the second switching means Q2 becomes a drive direction polarity and turns on.

Therefore, it is determined by the drive resonance capacitance C5 and the drive resonance inductance Ln2.

When the first switching means Q1 is turned off, the electromagnetic energy stored in the resonance inductance L2 is released, and the resonance inductance L2 parasitically acts on the DC cut capacitor C3, the resonance capacitor C4, and the second switching means Q2. Although the current continues to flow through the path of the diode, the primary winding p of the unsaturated transformer NST and the resonance inductance L2, when the current becomes 0, the charged electric charge of the resonance capacitor C4 becomes the DC cut capacitor C3 and the resonance. An inductance L2, a primary winding p of the unsaturated transformer NST, a second switching means Q2,
The path of the resonance capacitor C4 is discharged, and the current flows in the opposite direction. At this time, the voltage induced in the feedback winding s of the unsaturated transformer NST is higher at the terminal marked with the polarity symbol in the figure and lower at the other terminal. The first switching means Q1 which is resonated in the circuit DRC and the resonance voltage of which is applied via the drive circuit DC maintains the off state, and the second switching means Q2 maintains the on state.

However, when the resonance voltage of the drive resonance circuit DRC oscillates and the polarity is inverted, the first switching means Q1 is turned on again and the second switching means Q2 is turned off.

As a result, after the electromagnetic energy stored in the resonance inductance L2 is released, a current again flows from the positive electrode of the rectified DC power supply RD to the load circuit LC as described above. Hereinafter, the operation described above is repeated to operate as a half-bridge type inverter.
When the resonance voltage of the drive resonance circuit DRC is applied between the gate and the source of the switching means Q1 and Q2, the overvoltage portion is absorbed by the gate protection circuit GP, so that the gate is protected from the overvoltage.

In the load circuit LC, when a current flows through the resonance capacitor C4 during the above operation, the current flows into the filaments of the pair of electrodes E1 and E2 of the discharge lamp DL to heat the filaments electrically. Since the electrode E2 is in a thermoelectron emission state and a high voltage due to resonance is applied between the electrodes E1 and E2, the load D is eventually applied.
The L discharge lamp starts and lights up like an instant start.

When the discharge lamp of the load DL is turned on, the voltage between the electrodes E1 and E2 of the load DL becomes a lamp voltage that is as low as half the DC voltage. Therefore, the resonance of the resonance capacitor C4 is relaxed, but the unsaturated transformer is used. Voltage induction proportional to the lamp current is continued in the primary winding p of the NST.

Next, the protection operation when the discharge lamp DL becomes an abnormal discharge such as a half-wave discharge at the end of its life will be described. That is, when the discharge lamp DL has an abnormal discharge, the tube end portion of the discharge lamp DL in the discharge lamp has an abnormally high temperature of 150 ° C. or higher. This abnormally high temperature heats the drive resonance inductance, lowers the inductance, and raises the drive resonance frequency. As a result, the high frequency output voltage is lowered and the discharge of the discharge lamp DL is extinguished.

Hereinafter, second to fourth embodiments of the present invention will be described with reference to FIGS. 2 and 3. In each figure, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

FIG. 2 is a circuit diagram showing a second embodiment of the discharge lamp lighting device of the present invention. This embodiment differs from the first embodiment shown in FIG. 1 in the following points. 1. The feedback type drive resonance circuit DRC is composed of a series resonance circuit of a drive resonance inductance L _RD composed of a temperature-sensitive choke coil and a capacitor C5. 2. The feedback winding s is connected between both ends of the series resonance circuit.

Thus, this embodiment is basically the same as the first embodiment.

FIG. 3 is a circuit diagram showing a third embodiment of the discharge lamp lighting device of the present invention. This embodiment differs from the embodiment shown in FIG. 1 in the following points. 1. The feedback winding s is the resonance inductance L of the load circuit LC.
Magnetically coupled to 3. 2. Drive resonance capacitance C of drive resonance circuit DRC
Reference numeral 5'is composed of a temperature-sensitive ceramic capacitor, and is arranged at a position to detect a temperature rise when the discharge lamp DL is turned on. Further, the drive resonance inductance L _DR is a general one that does not have temperature sensitivity. 3. The noise filter NF includes a capacitor C1 and an inductor L _F. 4. The rectified DC power supply RD is a bridge type rectifier circuit BR.
C, resistor R4 and smoothing capacitor C2.

Thus, in this embodiment, when the discharge lamp DL has an abnormal discharge, the drive resonance capacitance C
Since 5 has a smaller capacity, the drive resonance frequency becomes higher, and basically the same protection operation as in FIG. 1 is performed.

The circuit of the fourth embodiment of the discharge lamp lighting device of the present invention is apparently the same as that of FIG. However, the drive resonance electrostatic capacitance C5 'formed of a temperature-sensitive ceramic capacitor has temperature characteristics such that the electrostatic capacitance decreases from the temperature at which the glow discharge of the discharge lamp DL transitions to the arc discharge.

FIG. 4 is a partially sectional front view showing a light bulb shaped fluorescent lamp as a first embodiment of the lighting apparatus of the present invention. In the figure, 1 is a fluorescent lamp, 2 is a lighting circuit means,
3 is a cover, 4 is a base, 5 is a glove, and 6 is a partition plate.

[Regarding Fluorescent Lamp 1] The fluorescent lamp 1 includes a translucent discharge vessel 1a and an electrode 1b. In the translucent discharge vessel 1a, four U-shaped glass tubes 1a1 having an outer diameter of 10 mm are connected by three connecting tubes 1a2, and each U-shaped glass tube 1a1 is evenly arranged on the circumference. Is formed in. Each U-shaped glass tube 1a1
Seal portions 1a3 are formed on both ends of the seal,
Each one thin tube 1a4 is projected to the outside from one seal part 1a3. The thin tube 1a4 is a translucent discharge vessel 1
It communicates with the inside of a. The thin tube 1a4 is used for exhausting the inside of the translucent discharge vessel 1, storing a main amalgam (not shown), and sealing a rare gas.

The connecting pipe 1a2 is formed by a blowout method. A phosphor layer is provided on the inner surface of each U-shaped glass tube 1a1. The phosphor layer is mainly composed of a three-wavelength light emitting phosphor, and the translucent discharge container 1
It is formed on the inner surface side of a through a protective film mainly composed of alumina fine particles (not shown).

The electrode 1b is composed of a filament electrode. The electrode 1b is formed by coating a double coil made of a tungsten wire with an oxide of an electron emitting substance made of an alkaline earth metal. The main amalgam is housed in the thin tube 1 a 4 of the translucent discharge vessel 1. And
The main amalgam is made of Bi-In-Hg having Hg of 6% by weight, and encloses three particles having a particle diameter of about 2.5 mm.
The auxiliary amalgam (not shown) is made by plating a thin plate of stainless steel with indium In, and is welded to the lead-in wire so as to be located in the vicinity of the main amalgam.

[Regarding Lighting Circuit Means 2] The lighting circuit means 2 employs any one of the circuit configurations of the discharge lamp lighting device shown in FIG. 1 to FIG. 3, and mainly comprises a half-bridge inverter. It is configured. The fluorescent lamp 1 is energized and turned on, and is housed in a cover 3 described later. The high-frequency output end is connected to the fluorescent lamp 1 as required, as will be described later. Further, the lighting circuit means 2 includes the wiring board 2a.
And the circuit component 2b mounted thereon. The main circuit component 2b is mounted on the lower surface of the wiring board 2a in the figure. On the other hand, the circuit component 2b includes the cover 3
Since the inner cavity has an inverted truncated cone shape, it is mounted on the wiring board 2a so that the outline thereof has a substantially inverted conical shape with the apex of a circuit component such as a tall capacitor. Also, a pair of switching means Q1, Q2
Is a drain exposed mold package MOSFET with a DIP terminal.

[Cover 3] The cover 3 is formed by molding a white light-blocking heat-resistant synthetic resin into a cup-shaped cylindrical body. Then, the base end 3a is narrowed down, the front end 3b is opened, and the inside forms a cavity for housing the circuit component.

[About the base 4] The base 4 is E26.
The cover 3 is formed of a shaped screw cap and is attached to the base end 3a of the cover 3 by caulking with a punch. The input end of the lighting circuit means 2 is connected to the center contact of the base 4 and the base shell.

[About Grove 5] Grove 5
Has a milky white light diffusing property by coating light diffusing fine particles on the inner surface of the transparent glass bulb, has an A shape, and surrounds the fluorescent lamp 1. The base end of the globe 5 is connected to the opening at the tip of the cover 3, and the globe 5 and the cover 3 form an envelope AJ.

[Regarding Partition Plate 6] Partition Plate 6
Supports the fluorescent lamp 1 and the wiring board 2a, and divides the inside of the envelope AJ into a light emitting chamber A and a lighting circuit housing chamber B. Further, the partition plate 6 has the following structure for supporting the fluorescent lamp 1 and the lighting circuit means 2 and fixing it to the cover 3 together with the globe 5. That is, the partition plate 6 is provided with a tubular portion 6a having a closed top portion that is open downward in the figure, and a flange portion 6b that projects to the outside of the tubular portion 6a. An insertion hole 6 is formed in the top surface 6a1 of the tubular portion 6a for inserting the vicinity of the seal portions at both ends of the U-shaped glass tube 1a1 of the translucent discharge vessel 1a of the fluorescent lamp 1.
a2 is formed, the vicinity of the seal portion of the U-shaped glass tube 1a1 is inserted, and the fluorescent lamp 1 is supported and fixed to the partition plate 6 by being bonded with a silicone adhesive (not shown). Further, the wiring board 2a is inserted and supported inside the lower end of the cylindrical portion 6a of the partition plate 6. Further, the partition plate 6 is inserted into the cover 3 so that the collar portion 6b of the partition plate 6 abuts on the inner surface of the cover 3 in the vicinity of the opening, and the open end of the globe 5 is inserted into the open end of the cover 3 from above. In this state, they are fixed by a silicone adhesive (not shown).

[0104]

According to each of the first to seventh aspects of the present invention, the DC power supply, the first switching means and the second switching means, and at least the resonance inductance and the resonance capacitance are provided. Of a load circuit that operates by high-frequency alternating current generated by the alternating switching of the switching means of (1), and that a discharge lamp is connected in parallel to at least a part of the resonance capacitance, and a feedback winding that feeds back the current flowing in the load circuit. , And a drive resonance inductance and a drive resonance capacitance, at least one of which is configured to change its constant in response to a temperature change accompanying the lighting of a discharge lamp of a load circuit A drive resonance circuit that resonates with the feedback voltage is included, and the first and By being provided with a feedback type drive signal generating circuit for on control alternately the second switching means, it has a simple circuit configuration of the drive resonant circuit,
Since the number of constituent circuit parts is small, it is easy to mount and a small wiring board is required, so it is suitable for downsizing of the device, and moreover, it is sensitive to the temperature accompanying the lighting of the discharge lamp and controlled to the optimum operating state. It is possible to provide a discharge lamp lighting device provided with a half-bridge type inverter capable of operating.

According to the second aspect of the present invention, in addition, the feedback winding includes the secondary winding of the unsaturated transformer in which the primary winding is connected in series with the load circuit. Since the primary winding of the unsaturated type transformer is installed separately,
Since high voltage due to resonance of load circuit is not applied, high reliability can be obtained without applying exceptionally high dielectric strength, winding formation is easy, cost can be reduced, and variation in characteristics is small. It is relatively easy to provide a discharge lamp lighting device that is easy to downsize an unsaturated transformer.

According to the invention of claim 3, the feedback winding is magnetically coupled to at least a part of the resonance inductance of the load circuit, so that a discharge lamp lighting device having a simple circuit configuration is provided. You can

According to the fourth aspect of the present invention, in addition, the feedback drive generation circuit is a discharge lamp lighting device comprising a temperature sensitive inductor in which the drive resonance inductance of the drive resonance circuit changes in response to a temperature change. Can be provided.

According to the fifth aspect of the present invention, in addition, the feedback drive generation circuit is a discharge lamp including a temperature-sensitive capacitor in which the drive capacitance of the drive resonance circuit changes in response to a change in temperature. A lighting device can be provided.

According to the sixth aspect of the present invention, in addition, in the drive resonance circuit, at least one of the drive resonance inductance and the drive resonance electrostatic capacitance is sensitive to the temperature change during abnormal discharge of the discharge lamp. By operating so that the resonance frequency becomes high, it is possible to provide a discharge lamp lighting device suitable for performing a protection operation at the time of abnormal discharge of the discharge lamp.

According to the seventh aspect of the present invention, in addition, in the drive resonance circuit, at least one of the drive resonance inductance and the drive resonance electrostatic capacitance is sensitive to the temperature change from the initial lighting of the discharge lamp, By operating so that the resonance frequency becomes high, it is possible to provide a discharge lamp lighting device suitable for accelerating the luminous flux rising at the time of lighting the discharge lamp.

According to the invention of claim 8, the discharge lamp lighting device according to any one of claims 1 to 7 supported by the lighting device main body is provided, so that the effects of claims 1 to 7 are achieved. A lighting device having the same can be provided.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of a discharge lamp lighting device of the present invention.

FIG. 2 is a circuit diagram showing a second embodiment of a discharge lamp lighting device of the present invention.

FIG. 3 is a circuit diagram showing a third embodiment of the discharge lamp lighting device of the present invention.

FIG. 4 is a partial cross-sectional front view showing a light bulb shaped fluorescent lamp as one embodiment of a lighting device of the present invention.

[Explanation of symbols]

C3 ... DC cut capacitor, C4 ... Resonance capacitor,
C5 ... Drive resonance capacitance, DL ... Discharge lamp, DR
C ... Drive resonance circuit, DSG ... Feedback type drive signal generation circuit, L2 ... Resonance inductance, LC ... Load circuit,
Q1 ... First switching means, Q2 ... Second switching means, RD ... Rectified DC power supply, s ... Feedback winding

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsutomu Araki             4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo             Itec Co., Ltd. F term (reference) 3K072 AA02 AA06 AC02 AC11 BA03                       BB01 BC01 CB06 DB03 DC07                       DD03 DD04 EA01 EA03 EB04                       EB09 GA03 GB12 GC02 HA03                       HA04 HA05

Claims (8)

[Claims] 1. A direct current power supply; first switching means and second switching means connected in series between the direct current power supplies; at least resonance inductance and resonance capacitance, and first and second switching means. A load circuit that operates by high-frequency alternating current generated by alternate switching of the means, and a discharge lamp is connected in parallel to at least a part of the resonance capacitance; a feedback winding that feeds back the current flowing in the load circuit; A feedback voltage generated in the feedback winding, with at least one of the drive resonance inductance and the drive resonance capacitance configured to change the constant in response to the temperature change accompanying the lighting of the discharge lamp of the load circuit. A drive resonance circuit that resonates with the first and second drive resonance circuits based on a resonance voltage of the drive resonance circuit. Discharge lamp lighting apparatus, characterized in that it comprises a; and feedback type drive signal generating circuit that turns on control switching means alternately. 2. The discharge lamp lighting device according to claim 1, wherein the feedback winding comprises a secondary winding of an unsaturated transformer in which the primary winding is connected in series to the load circuit. 3. The discharge lamp lighting device according to claim 1, wherein the feedback winding is magnetically coupled to at least a part of the resonance inductance of the load circuit. 4. The feedback type drive generation circuit comprises a temperature sensitive inductor whose drive resonance inductance of the drive resonance circuit changes in response to temperature change. The discharge lamp lighting device described. 5. A feedback type drive generation circuit comprising a temperature-sensitive capacitor whose drive resonance electrostatic capacitance of the drive resonance circuit changes in response to a temperature change. The discharge lamp lighting device according to any one of 1. 6. The drive resonance circuit operates so that the resonance frequency becomes high when at least one of the drive resonance inductance and the drive resonance capacitance is sensitive to a temperature change during abnormal discharge of the discharge lamp. The discharge lamp lighting device according to any one of claims 1 to 5, characterized in that: 7. The drive resonance circuit operates so that at least one of the drive resonance inductance and the drive resonance electrostatic capacitance is sensitive to a temperature change from the initial lighting of the discharge lamp and the resonance frequency becomes high. The discharge lamp lighting device according to any one of claims 1 to 5, characterized in that: 8. A lighting device comprising: a lighting device main body; and a discharge lamp lighting device according to claim 1, which is supported by the lighting device main body.