JP2003157991A - Discharge lamp lighting device and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device of which, terminal voltage of smoothing capacitors does not excessively increase before starting, and to provide a lighting device using the same. SOLUTION: The discharge lamp lighting device comprises input terminals a, b connected to a low frequency alternating current power source AS, a rectified direct current power source RDC having rectifying means D1, D2 and smoothing capacitors C6, C7, a high frequency generating means HFG generating high frequency voltage by switching the direct current output voltage, a load circuit LC having a resonance inductance L3 and a resonance inductance L9, to which, the high frequency voltage is applied, a discharge lamp DL connected to the load circuit LC, and a high frequency feedback circuit HFF feeding back high frequency electric energy from the load circuit LC so as to make the feedback quantity before the start of the discharge lamp DL smaller than that at lighting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimmable discharge lamp lighting device and a lighting device using the same.

[0002]

2. Description of the Related Art Light bulb type fluorescent lamps have a structure in which a compact fluorescent lamp and its lighting circuit means are integrated, and are compact like an incandescent light bulb for general lighting, and have a single base structure, but It is widely used because it is a light source that has both high lamp efficiency and long life, which are its characteristics, and that it can achieve significant power savings.

In general, compact fluorescent lamps that are commercially available are capable of lighting fluorescent lamps with high efficiency, and since they are required to be compact and lightweight, they are mainly used for high frequency lighting. Equipped with a high frequency inverter. The high-frequency inverter converts low-frequency alternating current into unsmoothed direct current using a rectifier circuit in order to input direct-current and converts it into high-frequency, and smoothes it from unsmoothed direct-current voltage using a smoothing capacitor. A capacitor input type that obtains direct current is used. (Prior Art 1) The bulb-type fluorescent lamp of the prior art 1 using the capacitor input method has an advantage that the circuit configuration is simple and the cost is low. However, the phase control type dimmer is used for the conduction angle for the following reasons. It is not possible to perform continuous dimming according to the change of. That is, the input current from the low-frequency AC power supply to the lighting circuit means becomes the charging current to the smoothing capacitor, but its inflow period is short and has a steep peak near the phase angle of 90 °, and the input current in other phase regions. Is the rest period.
Therefore, even if the phase control is performed in the range of the phase angle of 0 to 90 °, the charging charge of the smoothing capacitor does not substantially change. Therefore, the dimming control of the high frequency inverter can be performed in this phase angle region. Can not.

On the other hand, when the phase control dimmer is turned on during the input current rest period, the holding current cannot be secured,
In the phase control dimmer, the triac used as the phase control element is turned off, so that the on state cannot be maintained for half a cycle. As a result, the input current of the self-ballasted fluorescent lamp is increased and the life is shortened. Especially dimming upper limit (phase angle near 0 °) and dimming lower limit (phase angle around 180 °)
However, the flicker of the brightness is caused by the malfunction of the triac of the phase control dimmer.

On the other hand, recently, a light bulb type fluorescent lamp (prior art 2) capable of dimming has been developed. However, this prior art 2 employs a dedicated control IC as described in, for example, Japanese Unexamined Patent Publication No. 2001-273997, and the switching means of the inverter is optimal depending on the operation mode of the discharge lamp. The lighting circuit is configured so as to be separately excited at the operating frequency. According to the conventional technique 2,
By attaching a high-frequency feedback circuit that returns the high-frequency energy generated by the inverter to the low-frequency AC power supply, despite being a capacitor input method,
It is possible to smoothly control the light up to a dimming rate of about 10% while increasing the input power factor.

In a capacitor input type high frequency inverter, it is possible to extend a dimming range and reduce harmonic distortion by returning a part of generated high frequency to the low frequency AC power source side ( Prior art 3).

[0007]

However, the prior art 2
Can solve the drawbacks of the prior art 1,
There is a problem that the harmonic distortion cannot be improved as in the case of the related art 1.

Further, in the prior art 3, before starting, for example, when the filament electrode is preheated, the terminal voltage of the smoothing capacitor rises excessively due to the feedback of high frequency energy. That is, a part of the high-frequency feedback current also flows into the smoothing capacitor to charge the smoothing capacitor, whereas the discharge lamp discharges less and the smoothing capacitor discharges less, so the terminal voltage of the smoothing capacitor rises. . Under such circumstances, it is necessary to use a smoothing capacitor having a high withstand voltage grade, and accordingly, there is a problem that the smoothing capacitor becomes large in size and the cost increases.

An object of the present invention is to provide a discharge lamp lighting device in which the terminal voltage of the smoothing capacitor does not rise excessively before starting and a lighting device using the same.

Another object of the present invention is to provide a discharge lamp lighting device and a lighting device using the discharge lamp lighting device, in which the high frequency feedback efficiency at the time of all-light lighting is improved and the input efficiency during lighting is relatively high. To aim.

[0011]

A discharge lamp lighting device according to a first aspect of the present invention comprises an input terminal connected to a low frequency AC power source; a rectifying means and a smoothing capacitor, and rectifies an AC input from the input terminal. A rectified DC power supply for smoothing; a high frequency generation means for switching a DC output voltage of the rectified DC power supply to generate a high frequency voltage; a resonance inductance and a resonance capacitance, and a high frequency voltage generated by the high frequency generation means is applied. Load circuit;
A discharge lamp connected to the load circuit; and a high-frequency feedback circuit for returning high-frequency electric energy from the load circuit so that the amount of feedback before the discharge lamp is started is smaller than the amount of feedback during lighting. I am trying.

In the present invention and the following respective inventions, the definitions and technical meanings of terms are as follows unless otherwise specified. In the present invention, the discharge lamp lighting device is a circuit means for starting the discharge lamp and performing high frequency lighting. The circuit elements will be described below separately. In the present invention,
“High frequency” means a frequency of 10 kHz or higher, preferably a frequency of 20 to 200 kHz.

<Regarding Input Terminal> The input terminal is a circuit element located at the lowest frequency AC power source side of the discharge lamp lighting device, and the input terminal is a portion for receiving the input power source from the low frequency AC power source. It does not need to be formed of a special member, and thus the terminal fitting is not an essential requirement, and may be a simple conductive means or the like.
When the present invention is applied to a lighting device including a bulb-type fluorescent lamp, a base can be used as an input terminal.

<Regarding Rectified DC Power Supply> A rectified DC power supply is a means for converting a low-frequency AC voltage into a DC voltage, and therefore has an AC input terminal and a DC output terminal, and the AC input terminal has a low frequency. It is directly or indirectly connected to an AC power source and outputs a smoothed DC voltage or a partially smoothed DC voltage to a DC output terminal. Further, at least a rectifying means and a smoothing capacitor are provided.

As the rectifying means, various rectifying circuits can be adopted as desired. For example, a bridge type full wave rectifier circuit, a voltage doubler type full wave rectifier circuit, a center tap type full wave rectifier circuit, a half wave rectifier circuit, etc. can be used.

On the other hand, as the smoothing capacitor, it is allowed to form a known smoothing circuit such as a capacitor input system in which a smoothing capacitor is connected between the DC output terminals of the rectifying means or a partial smoothing circuit. . In any case, the smoothing capacitor is a means for relatively smoothing the non-smoothed DC voltage of the rectifying circuit, and generally one or a plurality of electrolytic capacitors are used according to the circuit system of the rectifying means. For example, in the case of a voltage doubler rectifier circuit, two smoothing capacitors are connected in parallel for charging and connected in series for discharging. By using the voltage doubler rectifier circuit, a DC output voltage higher than the input voltage can be obtained, so that boosting on the high frequency side becomes unnecessary or the boosting degree can be reduced. Further, the voltage doubler rectifier circuit is a capacitor input method because the smoothing capacitor is directly charged and smoothed by the unsmoothed DC voltage of the rectifier circuit. Further, the smoothing capacitor can be configured so as to obtain an almost completely flat smoothed DC voltage, but may be configured so as to obtain a smoothed DC voltage including an appropriate ripple if necessary. Next, in the case of a partial smoothing circuit, it is a circuit means for filling a valley portion of the non-smoothed DC voltage output from the rectifier circuit to form a partial smoothed voltage, and further includes a smoothing capacitor and a diode. In some cases, it is configured to include an inductor. The smoothing capacitor can use one or more of them. When a plurality of smoothing capacitors are used, the smoothing capacitors are connected in series and discharged in a state of being connected in parallel when charged by the unsmoothed DC voltage. Therefore, when the bulb-type fluorescent lamp is connected to a 100 V AC power source, the peak value of one smoothing capacitor is about 71 V if the partial smoothing circuit uses two smoothing capacitors. Similarly, in the case of three smoothing capacitors, the peak value is about 47V. A so-called multi-stage configuration using a plurality of smoothing capacitors, preferably a 2-stage or 3-stage partial smoothing capacitor is used. With the multi-stage configuration, the charging current of the smoothing capacitor, that is, the peak value of the input current can be reduced.
In the case of the stage configuration, the maximum input current is 0.4A. In addition, as can be understood from the name of the smoothing circuit, the smoothed DC voltage that is the output of the partial smoothing circuit is not sufficiently smoothed, and the peak waveform of the unsmoothed DC voltage remains and the peak waveform The valley between them is filled with a flat voltage.

<Regarding High-Frequency Generating Means> The high-frequency generating means includes at least one switching means, and the high-frequency AC voltage is generated by the switching. Regarding the circuit configuration of the switching means, various known inverter circuit systems can be adopted. Optimal is to use a half-bridge inverter. In this case, the switching means includes first and second switching means, which are connected in series so that the DC output voltage of the rectified DC power supply is applied to the first and second switching means. A high-frequency AC voltage is generated by the alternating switching of. Note that "connected in series so that the output DC voltage is applied" means
It means that the first and second switching means are connected in series when viewed from the rectified DC power supply, and another circuit component such as an inductor is provided between the first and second switching means and the rectified DC power supply. A resistor or the like may be interposed. Also, a circuit component may be interposed between the first and second switching means.

The switching means may be any drive type such as current drive type switching means such as a bipolar transistor, and voltage drive type switching means such as an FET. In the case of a half-bridge type inverter, the first and second switching means may be of the same polarity or complementary type. Since the FET is a voltage drive type switching means, it is easy to drive. Also,
The 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.

Further, the switching means is allowed to have a drive terminal. Then, when a drive signal of a predetermined polarity is supplied to the drive terminal, it is driven, that is, turned on. Enhancement type MOSF
In ET, 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.

Further, in the high frequency generating means, the drive of the switching means may be either of the separately excited type and the self excited type. In the case of the separately excited type, a drive signal is formed using a drive signal generation circuit having an oscillator. In the case of the self-excited type, the drive signal is formed by using the high frequency electric energy fed back from the load circuit according to the operating state of the discharge lamp.

By the way, in order to satisfactorily control the discharge lamp, the effective value of the phase-controlled low-frequency AC voltage applied between the input terminals and the conduction angle by the phase control, in other words, depending on the dimming rate. In order to light the discharge lamp with
It is desirable to configure the high frequency generating means to control the high frequency output using special means. For that purpose, for example, the effective value or conduction phase angle of the low-frequency AC voltage applied between the input terminals is detected, and the high-frequency output of the high-frequency generator is PWM-controlled or the operating frequency is controlled according to the detected value. As a result, when viewed from the discharge lamp, a high-frequency output that is almost proportional to the dimming degree is supplied to the discharge lamp.

Furthermore, by controlling the high frequency generating means,
The high-frequency voltage applied to the discharge lamp may be changed to an optimum value according to the operation mode of the discharge lamp. For example, since the discharge lamp is connected to the load circuit so as to be affected by the voltage drop that occurs in the resonance capacitance and resonance inductance of the load circuit, which will be described later, the voltage applied to the discharge lamp can be changed by changing the high frequency operation frequency. Changes according to the operating frequency. Therefore, a voltage having an optimum value can be applied between the electrodes of the discharge lamp according to the operation mode of the discharge lamp. In this case, the high frequency generating means may be of either the self-excited type or the separately excited type.

<Regarding Load Circuit> The load circuit constitutes a load when viewed from the high frequency generating means. Then, a high frequency AC voltage generated by the high frequency generating means is applied.
Further, the load circuit has a resonance inductance and a resonance capacitance to form a load resonance circuit, and is further connected to a later-described discharge lamp which is a load of the discharge lamp lighting device.

In addition, the load circuit provides a current limiting impedance that provides a ballasting action for the discharge lamp.
As the current limiting impedance, it is preferable to use a part or all of the resonance inductance. In this case, the core can be appropriately saturated in accordance with the magnitude of the current flowing through the resonance inductance.

Furthermore, when the load circuit is conductively connected to the high frequency generating means, a part of the resonance capacitance is connected in series to the discharge lamp as a DC cut capacitor so that DC current does not flow into the load circuit. Can be configured to. However, as a starting circuit of a discharge lamp, for example, a part or all of a resonance capacitance forming a series resonance circuit with a current limiting inductance is connected in parallel with the discharge lamp, and a resonance voltage appearing across the resonance capacitance is generated in the discharge lamp. Can be configured to be applied to.

Furthermore, in order to heat the pair of filament electrodes of the discharge lamp to a required temperature, an electrode heating circuit can be additionally provided. As the electrode heating circuit, a part or all of the resonance capacitance connected in parallel with the discharge lamp and either or both of the pair of filament electrodes can be connected in series. Also, by connecting a voltage induction winding to both ends of the filament electrode and magnetically coupling the winding to a current limiting inductor or an inductor provided separately from the current limiting inductor, for example, a step-up transformer, the heating voltage required for the filament electrode is increased. May be configured to be induced.

<Discharge Lamp> The type of the discharge lamp is not limited, but a low pressure discharge lamp such as a fluorescent lamp is preferable. Further, the discharge lamp may include either a hot cathode or a cold cathode.

<High-frequency feedback circuit> The high-frequency feedback circuit is a circuit for returning a part of the high-frequency energy from the load circuit to the low-frequency AC power supply side. In the present invention, the amount of feedback before starting the discharge lamp is on. It is controlled to be less than that. The above control may be performed by any circuit configuration. For example, when the high frequency generating means is configured to change the oscillation frequency according to the operation mode of the discharge lamp, the above conditions can be satisfied by configuring the high frequency feedback circuit to include a resonance circuit. become. Alternatively, a variable conduction means such as a transistor whose conduction is controlled according to the operation mode of the discharge lamp may be used. Further, “before starting” means, in the case of a fluorescent lamp or the like, a time when the filament electrode is preheated and a time when a secondary voltage is generated, both of which are in a light load state when viewed from the high frequency generation means.

Regarding the connection position of the high frequency feedback circuit to the load circuit, various suitable positions can be connected. It is possible to make the required return at any position. For example, a part or all of the voltage drop appearing in the resonance inductance, the resonance capacitance, or the like can be used for feedback.

<Regarding Other Configurations> Although not an essential component of the present invention, the performance of the discharge lamp lighting device is improved or a function is added by selectively adding the following configurations as needed. You can

1. Start-up circuit The start-up circuit is a means for starting the high-frequency generation means, and various known start-up circuit methods can be adopted.

2 Noise Filter The noise filter is provided between the input terminal and the rectified DC power supply in the circuit to prevent high frequency noise from the high frequency generation means from flowing out to the low frequency AC power supply side. Of course, a dimmer may be interposed between the low frequency AC power supply and the noise filter, and the phase-controlled low frequency AC voltage may be applied to the input terminal of the noise filter. The noise filter is generally composed of an inductor connected in series between a low frequency AC power supply and a rectifier circuit, and a capacitor connected in parallel with the low frequency AC power supply.

3. Snubber circuit The snubber circuit is composed of a series circuit of current limiting means such as a capacitor and a resistor, and can be connected between input terminals when the discharge lamp lighting device is configured to be capable of dimming. . Then, when the triac of the phase control dimmer, which will be described later, is turned on, it is configured to instantaneously flow a current equal to or larger than the holding current of the triac, thereby preventing malfunction of the triac.

4 Regarding Phase Control Type Dimmer A phase control type dimmer (hereinafter, simply referred to as "dimmer" unless otherwise necessary) is used for dimming a discharge lamp. Generally, it is not a circuit element that constitutes a light bulb type fluorescent lamp, but is embedded in a wall surface in a room or built in a lighting fixture. However, in the present invention, it can be incorporated as a part of the discharge lamp lighting device if necessary.

Further, the dimmer mainly includes a phase control element and an operation circuit for controlling the ON phase of the phase control element. The phase control element is a contactless switch element such as a triac or thyristor. The operation circuit is a circuit that supplies a conduction signal of a desired phase to the control terminal of the phase control element, and is provided with a phase shift circuit in which a variable resistor and a capacitor are connected in series and a trigger element such as a diac. A capacitor is connected in parallel to the phase control element so as to absorb noise generated by switching of the phase control element.

<Regarding Operation of the Present Invention> When the low frequency AC voltage is switched on between the input terminals, the DC output voltage smoothed by the operation of the rectified DC power supply is applied to the input terminal of the high frequency generating means. Then, the high-frequency generation means is activated and the switching means switches to output the high-frequency voltage to the output terminal. As a result of the high frequency voltage being applied to the discharge lamp via the load circuit, the discharge lamp will eventually start and light up. It should be noted that upon lighting, required preheating and generation of a starting voltage are sequentially performed.

On the other hand, when the high frequency generating means starts operating, a part of the high frequency electric energy is fed back to the AC input terminal of the rectified DC power source via the load circuit and the high frequency feedback circuit. Normally, since a noise filter is interposed between the input terminal and the rectified DC power supply, the high frequency component of the returned high frequency electric energy is filtered by the noise filter, and as a result, only the low frequency component is further low frequency AC power supply. Return to. Since this high-frequency feedback action is performed during almost the entire half cycle of the low-frequency AC voltage, the low-frequency AC power supply controls the low-frequency AC power regardless of the conduction angle of the phase control by the dimmer, and whether or not dimming is performed. It means that a frequency alternating current can continuously flow into the discharge lamp lighting device. As a result, the input power factor becomes relatively high and the harmonic distortion is also reduced. Note that the input power factor becomes “relatively high” means that the input power factor becomes higher than that when the harmonic feedback is not performed.
It does not necessarily mean only a high power factor.

Further, as a result of the above, when light control is performed, a current larger than the holding current flows when the triac of the dimmer is turned on, so malfunctions can be prevented and good light control is possible. It should be noted that a part of the returned high frequency electric energy flows into the rectified DC power source, is rectified and is charged in the smoothing capacitor.

Furthermore, in the present invention, there is a difference in the feedback amount of the high-frequency feedback circuit before starting and during lighting of the discharge lamp, and the feedback amount before starting is smaller than that during lighting. There is. On the other hand, before starting the discharge lamp, the high frequency output power supplied to the discharge lamp from the high frequency generating means is small because it is in a no-load state. Along with this, the power supplied from the smoothing capacitor to the input terminal of the high frequency generating means is small. The high-frequency electric energy fed back under such a situation is partially charged in the smoothing capacitor as described above.
Although the voltage at the terminal of the smoothing capacitor rises excessively, the amount of feedback is small in the present invention, so that it becomes possible to maintain the terminal voltage of the smoothing capacitor within an appropriate value range. On the other hand, during the lighting of the discharge lamp, the high frequency feedback amount is relatively increased, so that the above-described operation is appropriately performed.

Next, the circuit operation when dimming will be described. When the input terminal is connected to the low-frequency AC power source via the dimmer and the dimmer is operated, the phase-controlled low-frequency AC voltage is applied between the input terminals. If the high-frequency generator is configured to generate a high-frequency output that is substantially proportional to the effective value of the low-frequency AC voltage input from the input terminal, the discharge lamp is dimmed according to the dimming degree. In addition,
Even when the dimming degree is large, the high-frequency output of the high-frequency generating means becomes small, so that the high-frequency feedback circuit acts so as to make the amount of feedback relatively small. Then, even when the dimming degree is high, it is possible to prevent the terminal voltage of the smoothing capacitor from rising excessively.

The discharge lamp lighting device according to the invention of claim 2 is
An input terminal connected to a low-frequency AC power supply; a rectified DC power supply that is equipped with a rectifying means and a smoothing capacitor, and that rectifies and smoothes the AC input from the input terminal; and switches the DC output voltage of the rectified DC power supply. A high frequency generating means for generating a high frequency voltage; a load circuit having a resonance inductance and a resonance capacitance, to which the high frequency voltage generated by the high frequency generating means is applied; a discharge lamp connected to the load circuit; A circuit for providing high-frequency electric energy from the load circuit, which has resonance characteristics in the vicinity of the operating frequency of the high-frequency generating means at the time of lighting the light or its triple frequency.

The present invention differs from the invention of claim 1 in the configuration of the high-frequency feedback circuit. That is, the high-frequency feedback circuit has resonance characteristics, and the resonance characteristics of the operating frequency of the high-frequency generating means at the time of full-lighting of the discharge lamp or its triple frequency (third harmonic component of the basic operating frequency). It has a resonant frequency in the vicinity. In addition,
The term “near” with respect to a frequency is meant to include the frequency band and a frequency band in the range in which similar effects before and after the frequency are obtained. In a discharge lamp lighting device used for a light bulb type fluorescent lamp or the like, in order to appropriately perform preheating before starting, the high frequency generating means is often operated at an operating frequency different from the frequency at the time of lighting, for example, a high frequency. .
The present invention is suitable for such a case. That is, since the high-frequency feedback circuit has the resonance characteristic as described above, the impedance thereof becomes small at the time of lighting and the high-frequency feedback efficiency becomes high. As a result, the input power factor is increased and harmonic distortion is reduced.

On the other hand, before starting, the impedance of the high frequency feedback circuit is relatively large. For this reason,
At the time of starting, the amount of high-frequency feedback is reduced, and the excessive rise of the smoothing capacitor is suppressed.

By the way, the high frequency feedback circuit can be formed by connecting the load circuit and the input end side of the rectified DC power supply through an appropriate circuit element. As the circuit element, a capacitor, an inductor or a capacitor and an inductor can be mainly selected.
However, the high-frequency feedback circuit is not formed only by the additional portion connecting the load circuit and the input end side of the rectified DC power supply, but is inserted in the input end side of the load circuit and the rectified DC power supply. It is generally configured to include a part of the noise filter that is included. Therefore, it should be noted that the resonance characteristic of the high-frequency feedback circuit is not determined only by the additional circuit element described above, and the capacitors and inductors in the relevant portions of the load circuit and the noise filter may also have an influence. is there.

The discharge lamp lighting device according to the invention of claim 3 is
An input terminal connected to a low-frequency AC power supply; a rectified DC power supply that is equipped with a rectifying means and a smoothing capacitor, and that rectifies and smoothes the AC input from the input terminal; and switches the DC output voltage of the rectified DC power supply. High-frequency generating means for generating high-frequency voltage; load circuit having resonance inductance and resonance capacitance, to which high-frequency voltage generated by the high-frequency generating means is applied; discharge lamp connected to the load circuit; high-frequency resonance frequency before starting And a high-frequency feedback circuit for returning high-frequency electric energy from the load circuit, the resonance circuit having a resonance characteristic not near the operating frequency of the generating means.

The present invention is different in that the high frequency feedback circuit is configured to have a specific resonance characteristic. That is, since the high-frequency feedback circuit is configured as described above, the impedance of the high-frequency feedback circuit before starting is relatively high, and the amount of high-frequency feedback is reduced. As a result, the excessive rise of the smoothing capacitor before starting is suppressed.

In the above configuration, when the resonance characteristic of the high frequency feedback circuit is configured to be relatively close to the operating frequency of the high frequency generating means at the time of lighting, the high frequency becomes high at the time of lighting the discharge lamp. Since the resonance characteristic of the feedback circuit relatively approaches the resonance state, the amount of high-frequency electric energy fed back increases. However, during lighting, the load of the high-frequency generator increases and discharge of the smoothing capacitor increases. Therefore, even if the amount of charge to the smoothing capacitor increases as the amount of high-frequency electrical energy fed back increases, the smoothing capacitor becomes excessive. The rise does not occur. In addition, the input power factor becomes a high value and harmonic distortion is reduced.

The discharge lamp lighting device according to the invention of claim 4 is
An input terminal connected to a low-frequency AC power supply; a rectified DC power supply comprising a voltage doubler rectifier circuit; a DC output voltage of the rectified DC power supply alternately switched to generate a high-frequency voltage Separately-excited high-frequency generation means having a second switching means and a drive signal generation circuit for supplying a drive signal to these switching means; and detecting a conduction angle of an input voltage applied between input terminals. A conduction angle detecting circuit for controlling the drive signal generating circuit; a load circuit having a resonance inductance and a resonance capacitance, to which a high frequency voltage generated by the high frequency generating means is applied; a discharge lamp connected to the load circuit;
The resonance frequency is not near the operating frequency of the high-frequency generating means before starting, and the resonance frequency is near the operating frequency of the high-frequency generating means when the discharge lamp is fully lit or at a frequency three times as high as the operating frequency. And a high-frequency feedback circuit for returning energy.

The present invention defines the optimum configuration of the discharge lamp lighting device capable of dimming. That is, since the rectified DC power supply is composed of a voltage doubler rectifier circuit, it is possible to generate a high secondary voltage required at the time of start-up without adding boosting means to the load circuit. Therefore, the circuit configuration is simplified, the cost is reduced, and the size and weight can be reduced.

Since the high-frequency generating means constitutes a so-called half-bridge type inverter, it can be obtained at a low cost with few circuit components. Further, since the switching means of the high frequency generating means is of the separately excited type, it becomes possible to previously incorporate an operating frequency control program in accordance with a desired time schedule into the drive signal generating circuit, so that the operating mode of the discharge lamp can be adjusted. It is possible to surely perform optimum control. By integrating the drive signal generation circuit into an IC, the circuit can be downsized and the above control can be performed easily and accurately.

Since the conduction angle detection circuit is provided, the high frequency output of the high frequency generation means is reliably controlled to a value according to the conduction angle of the dimmer, the dimming characteristic is improved, and a wide range is obtained. Allows for dimming over light. Note that the conduction angle detection circuit may have any specific circuit configuration.

Since the high-frequency feedback circuit has the above-mentioned structure, the amount of high-frequency electric energy fed back is reduced before starting and suppresses the excessive rise of the smoothing capacitor. Further, during lighting, the amount of high-frequency electrical energy returned increases, the high-frequency feedback efficiency improves, the input power factor increases, and high-frequency distortion can be reduced. This tendency becomes stronger as it approaches full-light lighting, but it continues even during dimming lighting.

An illumination device according to a fifth aspect of the present invention comprises an illumination device main body; and the discharge lamp lighting device according to any one of the first to fourth aspects, which is disposed in the illumination device main body. It has a feature.

The lighting device is a broad concept including all devices that utilize the light emission of a discharge lamp, and thus includes, for example, a compact fluorescent lamp, a lighting fixture, a marker lamp, an indicating lamp, a signal lamp, an advertising lamp and various ultraviolet lamps. . Further, the “illuminating device main body” means the remaining portion of the illuminating device excluding the discharge lamp lighting device.

[0055]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a first embodiment of a discharge lamp lighting device of the present invention, FIG. 1 is a circuit diagram shown together with a dimmer, and FIG. 2 is a circuit diagram showing an internal circuit of the dimmer. 3 is a circuit diagram showing an internal circuit of the conduction angle detection circuit. In each figure, AS is a low frequency AC power supply, DM is a dimmer, L
OC is a discharge lamp lighting device. The discharge lamp lighting device LOC is connected to the low-frequency AC power supply AS via the dimmer DM. The discharge lamp DL is dimmed and lit by the phase control by the dimmer DM. Hereinafter, each of the above circuit elements will be divided.

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

<Regarding Dimmer DM> As shown in FIG. 2, the dimmer DM is a two-wire type (the other power source line is 11) inserted in series in one of a pair of power source lines, and has terminals. t
1, t2, triac TRIAC, operating circuit OC and capacitor C1. The terminal t1 is connected to the upper pole of the low-frequency AC power supply AS in FIG. Similarly, the terminal t2 is shared with the input terminal a of the discharge lamp lighting device OC. Further, a triac TRIAC and a capacitor C1 are connected in parallel between the terminals t1 and t2. The operation circuit OC includes a phase shift circuit PSC and a diac DIAC. Phase shift circuit PSC
Consists of a series circuit of a variable resistor R1 and a capacitor C2, and is connected in parallel to the triac TRIAC, and a diac DIAC is connected between the phase shift output terminal and the trigger terminal of the triac TRIAC.

<Regarding Discharge Lamp Lighting Device LOC> As shown in FIG. 1, the discharge lamp lighting device LOC includes input terminals a and b, a snubber circuit SN, a noise filter NF, a rectified DC power supply RDC, a high frequency generator HFG, and The load circuit LC, the discharge lamp DL, the high frequency feedback circuit HFF, the lamp current detection circuit CD, the lamp voltage detection circuit VD, and the conduction angle detection circuit CAD. Hereinafter, each component will be described.

(Regarding Input Terminals a and b) Input Terminal a,
b constitutes an input end of the discharge lamp lighting device.

(About Snubber Circuit SN) The snubber circuit SN is composed of a series circuit of a capacitor C3 and a resistor R2, and both ends thereof are connected between the input terminals a and b.

(Noise Filter NF) The noise filter NF is a rectifier circuit with an inductor L1 and a dimmer DM that are inserted in series in a line between a low-frequency AC power supply AS and an inductor L2 of a high-frequency feedback circuit HFF, which will be described later. It is composed of capacitors C4 and C5 connected in parallel between the lines with respect to the FBR. In addition, inductor L
1. The capacitors C4 and C5 are connected in a π shape.

(Regarding Rectified DC Power Supply RDC) The rectified DC power supply RDC constitutes a voltage doubler rectifier circuit with a pair of diodes D1 and D2 and a pair of smoothing capacitors C6 and C7. That is, a series circuit of the diode D1 and the smoothing capacitor C6 and a series circuit of the diode D2 and the smoothing capacitor C7 are connected in antiparallel between the input terminals a and b through the inductors L2 and L1. 2 between the connection point of C6 and the connection point of the diode D2 and the smoothing capacitor C7, that is, between the DC output terminals and the low frequency AC voltage.
Double DC output voltage can be obtained. In addition, the diode D1,
A low-frequency AC voltage is applied between the connection point of D2 and the connection points of the smoothing capacitors C6 and C7, that is, between the AC input terminals.

(Regarding High-Frequency Generating Means HFG) The high-frequency generating means HFG comprises a half-bridge type inverter having first and second switching means Q1 and Q2 and a drive signal generating circuit DSG.

The first and second switching means Q1,
Q2 is an N-channel MOSFET. The drain of the first switching means Q1 is connected to the positive output terminal of the rectified DC power supply RDC, and the source is connected to the drain of the second switching means Q2. The source of the second switching means Q2 is a rectified DC power supply RDC via a lamp current detection circuit CD described later.
It is connected to the negative output terminal of.

The drive signal generation circuit DSG comprises a fluorescent lamp inverter control driver IC, and outputs a drive signal for the first and second switching means Q1 and Q2 to alternately switch to each switching means Q1 and Q1.
Supply to Q2. In addition, the drive signal generation circuit DSG
Is configured such that the oscillation frequency of the drive signal is controlled according to the respective detection outputs by the control inputs of the detection outputs of the lamp current detection circuit CD, the lamp voltage detection circuit VD, and the conduction angle detection circuit CAD described later. Has been done. Further, the drive signal generation circuit DSG is configured so that the oscillation frequency of the drive signal changes according to a predetermined time schedule according to the operation mode of the discharge lamp.

(Regarding Load Circuit LC) Load Circuit LC
Is a DC cut capacitor C8 and a resonance inductance L
3 and the resonance capacitance C9 in a series circuit, one end on the DC cut capacitor C8 side is connected to the connection point of the first and second switching means Q1 and Q2, and the other end on the resonance capacitance C9 side is the lamp current. It is connected to the source of the second switching means Q2 via the detection circuit CD.

(Regarding Discharge Lamp DL> Discharge Lamp D
L is a fluorescent lamp, which is connected in parallel to the resonance capacitance C9 and has filament electrodes E1 and E.
Windings w1 and w2 are connected to both ends of the wire 2. The windings w1 and w2 are magnetically coupled to the resonance inductance L3 to form a filament heating circuit.

(Regarding High Frequency Feedback Circuit HFF) The high frequency feedback circuit HFF is mainly composed of inductors L2 and L4 and a capacitor C10 and has resonance characteristics. The inductor L2 is connected in series between the noise filter NF and the rectified DC power supply RDC so as to connect them. Inductor L4 and capacitor C
10 is connected in series and is connected between the connection point of the inductor L2 and the rectified DC power supply RDC and the connection point of the DC cut capacitor C8 and the resonance inductance of the load circuit LC. The resonance characteristic is set near the operating frequency of the high frequency generating means HFG when the discharge lamp DL is fully illuminated. The resonance characteristic of the high frequency feedback circuit HFF is influenced by the DC cut capacitor C8 of the load circuit LC and the capacitor C5 of the noise filter NF which are located near the circuit at the connection position, but in the case of the present embodiment, the DC cut capacitor is used. Increasing the capacitance of C8 makes it negligible.

(Regarding Lamp Current Detection Circuit CD) The lamp current detection circuit CD has a second
The lamp current is detected by detecting the source current of the switching means Q2, and the detection output is controlled and input to the drive signal generation circuit DSG.

(Regarding Lamp Voltage Detection Circuit VD) The lamp voltage detection circuit VD has its detection end connected in parallel to the discharge lamp DL and outputs a detection output to the drive signal generation circuit DSG.
Control input to. The internal circuit of the lamp voltage detection circuit VD is known.

(Conduction Angle Detection Circuit CAD) The conduction angle detection circuit CAD has its detection end connected between the input terminals a and b via the noise filter NF, and the detection output is controlled and input to the drive signal generation circuit DSG. . The conduction angle detection circuit CAD is composed of a resistor, a capacitor and a diode as shown in FIG.

<Regarding Circuit Operation> First, the high frequency generating operation in the non-dimming lighting to which the dimmer DM is not connected will be described. When the low-frequency AC power supply AS is switched on, the DC voltage that has been double-voltage rectified and smoothed by the rectified DC power supply RDC is applied to the input terminal of the high-frequency generation means HFG connected in series.

The high frequency generating means HFG is operated by a start-up circuit (not shown), and the drive signal generating circuit D
Since the SG starts to alternately supply the drive signal having the predetermined frequency to the first and second switching means Q1 and Q2, the SG is activated to supply the high frequency voltage to the load circuit LC. The drive signal generation circuit DSG changes the oscillation frequency of the drive signal as follows with the passage of time according to the time schedule of the built-in program. That is, when the switch is turned on, the oscillating operation is started at a frequency 2.5 times as high as the frequency during lighting (hereinafter referred to as "lighting frequency"), but the oscillating frequency is rapidly lowered and the frequency during preheating ( Hereinafter, it will be referred to as "preheating frequency".) For example, at 88 kHz, preheating is performed, and at the time of starting, the preheating frequency is sequentially reduced to the lighting frequency, for example, 50 kHz.

When a high frequency voltage is applied to the load circuit LC, its resonance inductance L3 and resonance capacitance C9 exhibit a resonance action in accordance with the operating frequency of the high frequency generation means HFG. Then, the terminal voltage of the resonance capacitance C9 is applied to the discharge lamp DL. The voltage applied to the discharge lamp DL during preheating is relatively low because the resonance effect is relatively weak.

On the other hand, the resonance inductance L3 has a winding w.
Since 1, w2 are magnetically coupled, the terminal voltage of the resonance inductance L3 is stepped down according to the turn ratio, and the winding w1,
Induced by w2. The induced voltage heats the filament electrodes E1 and E2. At this time, the discharge lamp DL
Since the voltage applied to the discharge lamp DL is low, the discharge lamp DL cannot be started and only preheating is performed. However, since the terminal voltage of the resonance inductance L3 during preheating is higher than that during lighting, preheating of the filament electrodes E1 and E2 is sufficiently performed.

At the time of starting, the operating frequency of the high frequency generating means HFG continuously changes from the preheating frequency to the lighting frequency. In the process of changing the operating frequency, the resonance inductance L3 of the load circuit LC and the resonance capacitance C9 relatively approach the resonance point, so that the terminal voltage of the resonance capacitance C9 increases. As a result, the discharge lamp DL starts and lights up. When the discharge lamp DL is turned on, the terminal voltage of the resonance inductance L3 drops, so the voltages of the windings w1 and w2 also drop, and the heating amount of the filament electrodes E1 and E2 is reduced as required.

The lamp current detection circuit CD and the lamp voltage detection circuit VD respectively monitor the lamp current and the lamp voltage during lighting of the discharge lamp DL and control-input their detection outputs to the drive signal generation circuit DSG. As a result, the operating frequency of the high frequency generating means HFG changes according to the changes in the lamp current and the lamp voltage, and acts to suppress the changes in the lamp current and the lamp voltage.

In the high frequency feedback circuit HFF, when the high frequency generating means HFG generates a high frequency, a part of the high frequency electric energy passes through the noise filter NF and the low frequency AC power supply A is supplied.
Return to S. Therefore, the input current continuously flows into the discharge lamp lighting device LOC during each half cycle of the low-frequency AC voltage. Further, the resonance characteristic of the high-frequency feedback circuit HFF is such that the high-frequency generating means HFG when the discharge lamp DL is in the full light state.
Since it is set near the operating frequency of the discharge lamp D
Since the impedance of the high frequency feedback circuit HFF becomes small due to resonance during the lighting of L, a sufficient feedback amount can be efficiently obtained, and as shown in FIGS. 4 and 5, a continuous input current during a half cycle is supplied from the low frequency AC power supply AS. Inflow. On the other hand, since the distance from the resonance point is further increased during lighting before starting, the impedance of the high-frequency feedback circuit HFF increases and the amount of high-frequency feedback decreases.

FIGS. 4 and 5 show different waveforms of the input current flowing from the input terminal when the discharge lamp lighting device according to the first embodiment of the present invention is lit up with all light, and FIG. 4 shows the input power factor. Is about 1, and FIG. 5 is a case where the input current waveform is about 0.65.

FIGS. 6 and 7 show waveforms of the terminal voltage V _DC of the smoothing capacitor before starting the discharge lamp. FIG. 6 shows the first embodiment of the discharge lamp lighting device of the present invention, and FIG. 7 shows the prior art. Is the case. By comparing the two figures, it can be seen that according to the present invention, an excessive increase in the terminal voltage _VDC of the smoothing capacitor does not occur before starting.

FIGS. 8 and 9 are graphs showing changes in the input power factor and the terminal voltage of the smoothing capacitor with respect to the resonance frequency of the high frequency feedback circuit in the discharge lamp lighting device of the present invention shown in FIGS. 8 shows the input power factor, and FIG. 9 shows the terminal voltage of the smoothing capacitor. In each figure, the horizontal axis indicates the resonance frequency f _X , and the vertical axis indicates the input power factor in FIG. 8 and the terminal voltage _{VDC in} the smoothing capacitor.

In FIG. 8, if the input power factor is 0.65 or more, malfunction of the dimmer can be prevented. Further, a high input power factor can be obtained when the resonance frequency f _X is in the vicinity of the lighting frequency at the time of full-light lighting or its triple frequency. According to FIG. 9, the terminal voltage V _DC of the smoothing capacitor becomes low when the resonance frequency f _X is in the vicinity of the lighting frequency at the time of all-light lighting or its triple frequency. Further, when the resonance frequency f _X is near the preheating frequency, the terminal voltage _VDC of the smoothing capacitor becomes extremely high.

Next, the circuit operation during dimming will be described. When the low frequency AC voltage whose phase is controlled by operating the dimmer DM is applied between the input terminals a and b, the conduction angle detection circuit CAD detects the conduction angle at that time, and the drive signal generation circuit DSG. To control. As a result, the oscillation frequency of the drive signal from the drive signal generation circuit DSG increases according to the conduction angle, and the lighting frequency of the high frequency generation means HFG also increases. Then, the lighting frequency changes to the resonance inductance L3 and the resonance capacitance C9 of the load circuit LC.
Since it goes away from the resonance point of, the terminal voltage of the resonance capacitance C9 decreases. Therefore, in the discharge lamp DL, the voltage applied between the electrodes E1 and E2 decreases, so that the dimming lighting is performed according to the dimming degree. In summary, when the dimmer DM is operated, the output of the high frequency generator HFG is controlled according to the dimming degree, and the discharge lamp DL is dimmed and turned on.

FIG. 10 is a circuit diagram showing a second embodiment of the discharge lamp lighting device of the present invention. In the figure,
The same parts as those of the above are given the same reference numerals and the description thereof will be omitted. In this embodiment, the high frequency generator HF of the load circuit LC is used.
The connection position for G is different. That is, the load circuit LC
Is a pair of switching means Q of the high frequency generating means HFG
It is connected in parallel to the first switching means Q1 which is the high side of the Q1 and Q2. Along with this, the current detection circuit CD is connected in series with the first switching means Q1.

11 to 13 show a bulb-type fluorescent lamp as an embodiment of the lighting device of the present invention.
Is a partially sectional front view, FIG. 12 is a plan view, and 13 is an exploded perspective view of a main part. In each figure, 1 is a fluorescent lamp, 2 is a lighting circuit, 3 is a cover, 4 is a base, 5 is a globe, and 6 is a partition plate.

[Regarding Fluorescent Lamp 1] Fluorescent Lamp 1
1 is a discharge lamp DL in FIGS. 1 to 3 and includes a translucent discharge vessel 1a, a phosphor layer, an ionization medium and an electrode 1b.

The translucent discharge vessel 1a has four outer diameters of 10 m.
The U-shaped glass tubes 1a1 of m are connected by three connecting tubes 1a2, and each U-shaped glass tube 1a1 is formed so as to be equally distributed on the circumference. Each U-shaped glass tube 1a1
Has a seal portion 1a3 formed at both ends thereof, and each thin tube 1a4 has one seal portion 1a3.
From the outside. The thin tube 1a4 communicates with the inside of the translucent discharge vessel 1a. Then, the inside of the translucent discharge vessel 1 is evacuated, and is used when accommodating a main amalgam (not shown) or enclosing a rare gas. The connecting pipe 1a2 is
It is formed by the blowing method.

Although not shown, the phosphor layer is mainly composed of a three-wavelength emission type phosphor, and mainly contains alumina fine particles (not shown) on the inner surface side of the translucent discharge vessel 1a. Is formed via a protective film.

The ionizing medium consists of amalgam and argon. Amalgam consists of a main amalgam and an auxiliary amalgam. Main amalgam is translucent discharge vessel 1
It is stored in the thin tube 1a4. The main amalgam is composed of Bi-In-Hg with Hg of 6% by mass, 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.

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.

[Regarding Lighting Circuit 2] The lighting circuit 2 is the discharge lamp lighting device LOC having the circuit configuration shown in FIGS. 1 to 3. Therefore, although the details of the circuit configuration are as described above, the fluorescent lamp 1 is energized and turned on, and is housed in the cover 3 described later. The high-frequency output end is connected to the fluorescent lamp 1 as required, as will be described later. Also, the lighting circuit means 2
Is the wiring board 2a and the circuit component 2b mounted thereon.
Consists of. The main circuit component 2b is mounted on the lower surface of the wiring board 2a in the figure. On the other hand, circuit component 2
In b, since the cavity inside the cover 3 has an inverted frusto-conical shape, the wiring board 2a has a substantially conical shape with the apex of a circuit component such as a tall capacitor. It is implemented. Further, the pair of switching means Q1 and Q2 are drain exposed mold package type MOSFETs having a DIP terminal.

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

[About the mouthpiece 4] The mouthpiece 4 is composed of an E26 type screw mouthpiece, and is attached to the base end 3a of the cover 3 by caulking with a punch. The input end of the lighting circuit 2 is connected to the center contact of the base 4 and the base shell.

[Regarding Globe 5] The globe 5 has a milky white light diffusing property by coating light diffusing fine particles on the inner surface of the transparent glass bulb, and has an A shape, and the fluorescent lamp 1
Surrounds. In addition, in each figure, the inside is seen through for convenience. Then, 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 are
It forms the envelope AJ.

[Regarding Partition Plate 6] The 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 storage 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 cylindrical portion 6a whose top is closed downward in the figure and a flange portion 6b which projects to the outside of the cylindrical portion 6a. And the cylindrical portion 6a
The top surface 6a1 of the U-shaped glass tube 1a is formed with insertion holes 6a2 into which 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 is inserted.
1 is inserted in the vicinity of the seal portion and adhered by a silicone adhesive (not shown) to support and fix the fluorescent lamp 1 on the partition plate 6.

The wiring board 2a is inserted and supported inside the lower end of the cylindrical portion 6a of the partition plate 6.

Further, the collar portion 6b of the partition plate 6 covers the cover 3
The partition plate 6 is inserted into the cover 3 so as to come into contact with the inner surface near the opening of the cover 3, and is fixed by a silicone adhesive (not shown) in a state where the opening end of the globe 5 is inserted into the opening end of the cover 3 from above. Has been done.

[0101]

According to the first aspect of the present invention, an input terminal connected to a low frequency AC power supply, a rectified DC power supply provided with a rectifying means and a smoothing capacitor, and a DC output voltage thereof are switched to generate a high frequency voltage. High frequency generating means for generating,
A load circuit with resonance inductance and resonance capacitance, to which a high frequency voltage is applied, a discharge lamp connected to the load circuit, and the amount of feedback from the load circuit so that the amount of feedback before starting the discharge lamp is less than the amount of feedback during lighting. By including the high frequency feedback circuit for feeding back energy, it is possible to provide a discharge lamp lighting device in which the terminal voltage of the smoothing capacitor does not rise excessively before starting.

According to the second aspect of the invention, in addition, the high frequency feedback circuit is provided with a resonance characteristic in which the resonance frequency is in the vicinity of the operating frequency of the high frequency generating means or the triple frequency thereof when all the light of the discharge lamp is lit. This is suitable for operating the high-frequency generator at an operating frequency different from the lighting frequency in order to appropriately perform preheating at the time of starting, and it is possible to sufficiently increase the input power factor during full-light lighting. A discharge lamp lighting device capable of being provided can be provided.

According to the third aspect of the present invention, in addition, since the high frequency feedback circuit has the resonance characteristic that the resonance frequency is not in the vicinity of the operating frequency of the high frequency generating means before starting, the smoothing capacitor before starting is excessive. It is possible to provide a discharge lamp lighting device that suppresses excessive rise.

According to the invention of claim 4, in addition, the rectified DC power supply is composed of a voltage doubler rectification circuit, and the high frequency generation means constitutes a separately excited half bridge type inverter having a drive signal generation circuit, It is equipped with a conduction angle detection circuit that detects the conduction angle of the voltage and controls the drive signal generation circuit.
The high-frequency feedback circuit is provided with resonance characteristics in which the resonance frequency is not near the operating frequency of the high-frequency generating means before starting, and is near the operating frequency of the high-frequency generating means when all the light of the discharge lamp is lit or a triple frequency thereof. As a result, it is possible to provide a small and lightweight discharge lamp lighting device having a relatively simple circuit configuration.

According to the invention of claim 5, the lighting device main body and the discharge lamp lighting device according to any one of claims 1 to 4 provided in the lighting device main body are provided. An illumination device having the effects of items 1 to 4 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 together with a dimmer.

FIG. 2 is a circuit diagram showing an internal circuit of the dimmer.

FIG. 3 is a circuit diagram showing an internal circuit of a conduction angle detection circuit.

FIG. 4 is a waveform chart showing an input current waveform flowing from an input terminal when the discharge lamp lighting device according to the first embodiment of the present invention has an input power factor of approximately 1 when the discharge lamp is fully lit.

FIG. 5 is a waveform diagram when the input power factor is 0.65.

FIG. 6 is a waveform chart showing a terminal voltage V _DC waveform of the smoothing capacitor before starting the discharge lamp in the first embodiment of the discharge lamp lighting device of the present invention.

FIG. 7 is a waveform diagram showing a terminal voltage _VDC waveform of a smoothing capacitor before starting a discharge lamp in a conventional technique.

FIG. 8 is a graph showing changes in the input power factor with respect to the resonance frequency of the high frequency feedback circuit in the discharge lamp lighting device of the present invention shown in FIGS. 1 to 3.

FIG. 9 is a graph showing changes in the terminal voltage of the smoothing capacitor with respect to the resonance frequency of the high frequency feedback circuit.

FIG. 10 is a circuit diagram showing a second embodiment of the discharge lamp lighting device of the present invention.

FIG. 11 is a partial sectional front view showing a bulb-type fluorescent lamp as an embodiment of the lighting device of the present invention.

FIG. 12 is a plan view of the same.

FIG. 13 is an exploded perspective view of the same main part.

[Explanation of symbols]

a ... Input terminal AS: Low frequency AC power supply b ... Input terminal C6 ... Smoothing capacitor C7 ... Smoothing capacitor C8 ... DC cut capacitor C9 ... Resonance capacitance CAD ... Conduction angle detection circuit CD: Current detection circuit DL ... Discharge lamp DM: Phase control dimmer HFF ... High frequency feedback circuit HFG ... High frequency generator L3 ... Resonance inductance LC: Load circuit LOC ... Discharge lamp lighting device NF ... Noise filter Q1 ... First switching means Q2 ... Second switching means RDC: rectified DC power supply SN ... Snubber circuit VD: Lamp voltage detection circuit

Continued front page    F term (reference) 3K072 AA02 AA05 AA06 AC02 AC11                       CA03 CA11 DB03 DD03 DD04                       DE02 DE04 DE05 FA01 FA05                       GA03 GA05 GB12 HA05 HA06                       HA10 HB09 HB10                 3K098 CC22 CC41 CC56 CC57 DD20                       DD44 EE03 EE12 EE14 EE17                       EE20 EE28 EE33 EE35 FF03                       FF04 FF14 GG10

Claims (5)

[Claims] 1. An input terminal connected to a low-frequency AC power supply; a rectified DC power supply, comprising rectifying means and a smoothing capacitor, for rectifying and smoothing AC input from the input terminal; DC output of the rectified DC power supply A high frequency generating means for switching a voltage to generate a high frequency voltage; a load circuit including a resonance inductance and a resonance capacitance, to which the high frequency voltage generated by the high frequency generating means is applied; a discharge lamp connected to the load circuit; a discharge lamp A high-frequency feedback circuit for feeding back high-frequency electrical energy from a load circuit so that the amount of feedback before starting is smaller than that during lighting. 2. An input terminal connected to a low-frequency AC power supply; a rectified DC power supply, comprising rectifying means and a smoothing capacitor, for rectifying and smoothing the AC input from the input terminal; DC output of the rectified DC power supply. A high frequency generating means for switching a voltage to generate a high frequency voltage; a load circuit including a resonance inductance and a resonance capacitance, to which the high frequency voltage generated by the high frequency generating means is applied; a discharge lamp connected to the load circuit; a resonance frequency Is provided with a resonance characteristic in the vicinity of an operating frequency of the high frequency generating means or a triple frequency thereof when the discharge lamp is fully lit, and a high frequency feedback circuit for returning high frequency electric energy from the load circuit. A discharge lamp lighting device characterized by the above. 3. An input terminal connected to a low-frequency AC power supply; a rectified DC power supply which comprises rectifying means and a smoothing capacitor and rectifies and smoothes AC input from the input terminal; DC output of the rectified DC power supply. A high frequency generating means for switching a voltage to generate a high frequency voltage; a load circuit including a resonance inductance and a resonance capacitance, to which the high frequency voltage generated by the high frequency generating means is applied; a discharge lamp connected to the load circuit; a resonance frequency And a high-frequency feedback circuit for returning high-frequency electric energy from a load circuit with a resonance characteristic that is not near the operating frequency of the high-frequency generating means before starting. 4. An input terminal connected to a low frequency AC power supply; a rectified DC power supply comprising a voltage doubler rectifier circuit; a DC output voltage of the rectified DC power supply is alternately switched to generate a high frequency voltage in series. Separately-excited high-frequency generating means having first and second switching means connected thereto and a drive signal generating circuit for supplying a drive signal to these switching means; and continuity of an input voltage applied between input terminals. A conduction angle detection circuit for detecting an angle and controlling a drive signal generation circuit; a load circuit having a resonance inductance and a resonance capacitance, to which a high frequency voltage generated by a high frequency generation means is applied; a discharge lamp connected to the load circuit When the resonance frequency is not near the operating frequency of the high-frequency generating means before starting, and when the discharge lamp is fully illuminated A high frequency feedback circuit for feeding back the high frequency electric energy from the load circuit comprises a resonance characteristic in the vicinity of the operating frequency or a frequency tripled the frequency generation means;
A discharge lamp lighting device comprising: 5. A lighting device comprising: a lighting device main body; and the discharge lamp lighting device according to claim 1, which is provided in the lighting device main body.