JP2005183026A - Discharge lamp lighting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device lighting a plurality of discharging lamps connected in parallel with each other, enabled to aim at cost reduction, preventing excessive current from flowing in a high-frequency inverter at the instance an inductor for the ballast is saturated at start-up and to provide a lighting system using the above lighting device. <P>SOLUTION: The discharge lamp lighting device is provided with a plurality of lighting main circuits OC connected in parallel each including a series circuit of a discharge lamp DL and an inductor L1, a high-frequency inverter HFI having at least a preheating mode and a starting mode as output characteristics and common to the plurality of lighting main circuits, and a direct current power source DC of the high-frequency inverter. At the starting mode of the high-frequency inverter HFI, the inductor L1 of either one of the plurality of lighting main circuits OC first gets saturated to light the discharge lamp of the said lighting circuit, and then the inductors L1 of the rest of the lighting main circuits get saturated in turn to light the discharge lamps of the corresponding main circuits. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device for lighting a plurality of discharge lamps in parallel, and an illumination device using the same.

  It is known to connect a plurality of discharge lamps in parallel by connecting in parallel a plurality of lighting main circuits formed by connecting discharge lamps in series with a ballast choke coil. If connected in parallel or in series to the high frequency inverter, a plurality of discharge lamps can be lit at high frequency.

  On the other hand, a high-frequency inverter type discharge lamp lighting device in which the ballast choke coil is saturated at start-up and the ballast choke coil is miniaturized is known as a discharge lamp lighting device for a bulb-type fluorescent lamp.

In addition, it is already known that the discharge lamp lighting device is configured to perform current feedback control using an unsaturated transformer separately from an inductor element that is saturated at start-up (see Patent Document 1). In this discharge lamp lighting device, the primary winding of the unsaturated transformer is inserted in series with the lighting main circuit, and a drive resonance circuit using the inductance of the secondary winding of the unsaturated transformer is formed. The drive signal for the switching element of the high-frequency inverter is formed. According to this discharge lamp lighting device, since the high voltage due to the resonance of the lighting main circuit is not applied to the unsaturated transformer, it is possible to obtain high reliability without giving the unsaturated transformer a particularly high dielectric strength. In addition, the unsaturated transformer can be made inexpensive and downsized.
JP 2001-155883 A

  However, when a plurality of lighting main circuits formed by connecting a discharge lamp in series with a ballast choke coil according to the above-described prior art are connected in parallel to a common high-frequency inverter, and when the ballast choke coil is saturated at the start, It has been found that inconvenience arises when the discharge lamps are started simultaneously. That is, when a plurality of ballast choke coils are saturated at the same time, an excessive current flows through the high-frequency inverter, so that excessive stress is applied to the circuit components, particularly the switching elements. For this reason, it is necessary to change the circuit component to one having a higher rating, which increases the cost of the discharge lamp lighting device.

  In the present invention, a plurality of discharge lamps are lit in parallel, and at the moment when the ballast inductor is saturated at the start-up, an excessive current does not flow to the high-frequency inverter so that the cost can be reduced. An object is to provide a device and an illumination device using the same.

  Another object of the present invention is to provide a discharge lamp lighting device and a lighting device using the same that effectively suppress the occurrence of instantaneous flickering of the discharge lamp when the power is turned on. .

  The discharge lamp lighting device of the invention of claim 1 includes a series circuit of a discharge lamp and an inductor that saturates at start-up, a plurality of lighting main circuits connected in parallel; and at least a preheating mode and a start-up mode in output characteristics; A common high-frequency inverter that outputs a high-frequency voltage to a plurality of lighting main circuits and energizes a discharge lamp; and a direct-current power source connected to an input terminal of the common high-frequency inverter. The inductor of any one of the plurality of lighting main circuits is saturated first and the discharge lamp of the lighting main circuit is lit, and then the remaining inductors of the lighting main circuit are saturated and the lighting main circuit is saturated. The circuit is characterized in that the discharge lamps of the circuit are sequentially turned on.

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

  <About the lighting main circuit> The lighting main circuit includes a series circuit of a discharge lamp and an inductor saturated at the time of starting. The series circuit includes a discharge lamp and an inductor that saturates at start-up as essential components, but allows other circuit components to be connected in series or in parallel as desired. Such additional circuit components include, for example, a DC cut capacitor, current feedback circuit means, such as an unsaturated transformer, that is, an unsaturated current transformer. The DC cut capacitor is used to cut a DC component that flows out from the output terminal of the high frequency inverter. The current transformer is used when the high-frequency inverter is controlled to self-oscillate by feeding back the current flowing through the lighting main circuit. However, when self-excited oscillation control of a high-frequency inverter is performed by feeding back the current flowing in the lighting main circuit, it is not always necessary to use a current transformer, and if desired, for example, a feedback winding may be magnetically coupled to an inductor that is saturated at start-up. It can also be arranged.

  A plurality of the lighting main circuits are connected in parallel to a high-frequency inverter described later. Therefore, the plurality of discharge lamps are energized from a high-frequency inverter described later and are lit in parallel.

  Any discharge lamp may be used, but a low-pressure discharge lamp such as a fluorescent lamp is suitable. Further, when a low pressure discharge lamp is provided with a hot cathode electrode, a preheating mode is provided in the output characteristics of a high frequency inverter described later, and in order to preheat the hot cathode electrode during the preheating mode, in parallel with the discharge lamp, that is, A resonant capacitor can be connected between one power supply side terminal of the pair of hot cathode electrodes and the other power supply terminal or power supply terminal of the same electrode. As a result, the resonant capacitor is connected to the lighting main circuit via at least one non-power supply side terminal of the pair of hot cathode electrodes in the discharge lamp. Then, a series resonance circuit that performs moderate resonance by connecting in series to an inductor that is saturated at the time of starting is formed. Thus, in the preheating mode before starting, an appropriate preheating current can be supplied to the hot cathode electrode via the resonance capacitor to preheat the electrode as required. In the starting mode, the voltage increased by the series resonance between the resonant capacitor and the inductor saturated at the time of starting can be applied as the starting voltage between both ends of the discharge lamp to promote the starting. In the case of a discharge lamp provided with a cold cathode electrode, a high resonance voltage can be applied to the discharge lamp at the start only by connecting a resonance capacitor in parallel with the discharge lamp.

  An inductor that saturates at start-up is a circuit element means having a required inductance even at the time of saturation in order to exert a ballast action on the discharge lamp, and allows the form of a choke coil, a transformer, or the like. . In addition, the inductor is designed so that the winding design and the frequency setting for the inductor are designed so as not to be saturated before starting, for example, during preheating, and when the output characteristics are changed by frequency control, the saturation threshold is The frequency is preferably between the preheating frequency and the starting frequency. Note that it is preferable that the starting frequency be in the slow phase region and be as close to the threshold frequency as possible.

  <About a high frequency inverter> A high frequency inverter is a power supply means which applies a required voltage to a lighting main circuit according to each operation mode of the output characteristic, and supplies the electric power required for lighting of a discharge lamp. The high-frequency inverter may be of any circuit type as long as it converts a DC voltage into an AC voltage. However, a half-bridge type inverter is preferable in that the circuit configuration is simple and can be obtained at low cost.

  In the present invention, regardless of the circuit system of the high-frequency inverter, the excitation system of the main switching element provided therein may basically be either self-excited oscillation or separately-excited oscillation. When the high-frequency inverter is a self-excited oscillation system, the current flowing through the lighting main circuit can be fed back as described above to drive the main switching element. On the other hand, in the case of the separately excited oscillation method, an oscillation circuit is provided, and a drive signal can be formed according to the oscillation signal output from the oscillation circuit to drive the main switching element. An oscillation signal can be generated using a microcomputer or an oscillation circuit in an IC together with the control of a high frequency output described later.

  Further, the high-frequency inverter generally sets the output characteristics so that the high-frequency voltage that is the output changes according to the stage of operation of the discharge lamp. In the present invention, at least a preheating mode and a starting mode are selectively provided as output characteristics of the high frequency inverter. The “preheating mode” is an output characteristic in which the hot cathode electrode is preheated to thermionic emission state in the pre-starting stage, and the starting voltage is set so that the discharge lamp does not start undesirably during preheating. A lower voltage is configured to be applied to the discharge lamp. The “start mode” is an output characteristic of the high-frequency inverter when starting the discharge lamp, and generates an output that promotes the start of the discharge lamp by applying a high voltage between a pair of electrodes of the discharge lamp. After the discharge lamp is started and lit, the start mode may be maintained, or a lighting mode may be set separately. For example, when performing dimming lighting, the control circuit is simplified by maintaining the start mode state. When the lighting mode is set separately from the start mode, for example, it is suitable for the case where the light is turned on in the all-light lighting state, and it is preferable that a high frequency voltage lower than that in the start mode is output. “All-light lighting” means that the discharge lamp is lit at 100% brightness preset as a discharge lamp lighting device. Therefore, the brightness at the time of rating inherent to the discharge lamp does not uniquely mean. In general, a voltage lower than the starting voltage is applied to the discharge lamp when all the lights are on. “Dimming lighting” means lighting with a brightness of less than 100%.

  As an output characteristic of the high-frequency inverter, in addition to the preheating mode and the start mode, a start mode can be added as desired. “Start-up mode” is an output characteristic when the high-frequency inverter is turned on, and is sufficiently low so that the discharge lamp does not cause undesired operation due to a transient phenomenon caused by turning on the power, for example, the discharge lamp does not flicker instantaneously. It is preferable to be configured to output a voltage. In addition, the output voltage at the time of starting can be set so that it may change in steps or continuously.

  Furthermore, in order to change the output characteristics of the high-frequency inverter, a frequency control method for changing the output frequency, a PWM control method for changing the on-duty of the output voltage, a peak value control method for changing the peak value of the output voltage, and one of these methods. Any of eclectic parts may be used. In the first control method, by changing the output frequency, the operating point with respect to the resonance characteristic of the lighting main circuit changes, so the voltage applied to the discharge lamp changes. Therefore, in this method, it is not necessary to change the output voltage.

  <Regarding the DC Power Supply> The DC power supply is a power supply for applying a DC voltage to the input terminal of the high-frequency inverter, and may have any circuit configuration as long as it outputs a DC voltage of a required value. As the DC power source, for example, a battery power source or a rectified DC power source that rectifies an AC voltage can be used. However, if there is a difference between the input voltage of the high frequency inverter and the output voltage of the battery power supply or rectified DC power supply, a switching power supply can be added so as to be interposed between the high frequency inverter and the power supply. . As the switching power supply, a step-up chopper is preferably used when boosting is required, and a step-down chopper is preferable when stepping down is required. Further, the above switching power supply can be configured to operate effectively when controlling the output characteristics of the high-frequency inverter as desired. That is, in the case of a high-frequency inverter whose output voltage is proportional to the input voltage, such as a half-bridge type inverter or a full-bridge type inverter, the output voltage of the high-frequency inverter is changed by changing the input voltage to the high-frequency inverter with a switching power supply as desired. Can be controlled.

  <Sequential lighting of a plurality of discharge lamps> A plurality of discharge lamps can be sequentially started to light up by changing saturation characteristics between inductors in a plurality of lighting main circuits in advance. The difference in saturation characteristics may be relatively small. Therefore, it is only necessary to give appropriate characteristic variations to a plurality of inductors in advance and select the characteristic variations.

  <About the operation of the present invention> In the present invention, when a plurality of lighting main circuits connected in parallel are applied with a relatively high high-frequency voltage from the high-frequency inverter in the start mode, the plurality of discharge lamps are reduced in time by the following operation. It starts and lights up sequentially. That is, when a high-frequency voltage in the start mode is applied from the high-frequency inverter, the inductor of the lighting main circuit having the inductor that is most saturated among the plurality of lighting main circuits at that time is instantaneously saturated first. The discharge lamp belonging to the lamp lights up. At this time, the inductors belonging to the remaining lighting main circuits are not saturated because they do not reach the saturation condition. Therefore, the remaining discharge lamp does not light up. The inductor does not saturate during the preheating mode.

  However, following the first lighting, the inductor of the lighting main circuit having an inductor that is likely to be saturated next among the remaining lighting main circuits is saturated, and the discharge lamp belonging thereto is lighted next. Note that the drop in the DC power supply voltage due to the saturation of the first inductor is instantaneous and then returns to the original value, so that the inductor that is likely to be saturated next becomes more saturated. Thereafter, the above operation is repeated, and the remaining discharge lamps are sequentially turned on in a short time. There may be two or more lighting main circuits.

  It should be noted that only when the first inductor is saturated, a large current flows through the lighting main circuit, and accordingly, the DC power supply voltage decreases, and accordingly, the high-frequency voltage output from the high-frequency inverter decreases. For this reason, the remaining inductors of the lighting main circuit are less likely to be saturated at the same time. In addition, in the case of frequency control, when the inductor that is most likely to be saturated is saturated, the output frequency increases momentarily. As a result, the high-frequency voltage applied to the discharge lamp decreases, and the remaining discharge lamp is less likely to be saturated at the same time.

  In the above circuit operation, when the inductor of one lighting main circuit is saturated, a large current flows in the lighting main circuit. However, when viewed from a high-frequency inverter in which a plurality of lighting main circuits are connected in parallel, the current is so large. It will not be. Therefore, the current flowing through the high-frequency inverter when the discharge lamp is sequentially started within a relatively short time does not become an excessive value that causes a problem. This prevents excessive stress from being applied to the high-frequency circuit components, particularly the switching elements. For this reason, it is not necessary to change a circuit component to a thing with a high rating, and it does not cause the cost increase of a discharge lamp lighting device.

  Further, when the inductor of the lighting main circuit is configured to saturate at the time of starting, the inductor can be reduced in size and reduced in cost, so that it is easy to reduce the size and cost of the discharge lamp lighting device.

  <Other Configurations of the Present Invention> Although not an essential component of the above-described invention, the utility of the discharge lamp lighting device is enhanced by including the following configuration.

  (Configuration for Startup Mode) A preferable configuration for startup mode is as follows.

A lighting main circuit including a series resonant circuit of an inductor and a resonant capacitor that saturates at start-up and having a discharge lamp connected in series to the inductor;
Outputs a high-frequency voltage whose frequency changes according to each operation mode of the output characteristics, applies it to the lighting main circuit to energize the discharge lamp, and has start-up mode, preheating mode and start-up mode as output characteristics, and start-up A high-frequency inverter configured to output a high-frequency voltage having a frequency separated from the resonance point of the series resonance circuit of the lighting main circuit in the preheating mode;
A DC power source connected to the input end of the high-frequency inverter;
A discharge lamp lighting device comprising:

In the above configuration, the frequency of activation mode and f0, the frequency of the preheat mode and f _PH, when the frequency during startup mode and f _ST, when arranging the respective frequencies in the order of height, as follows It is good to do. The output characteristics are preferably set so as to use the resonance in the slow phase region.

f0> _fPH > _fST
By using a half-bridge inverter, the high-frequency inverter is simplified and downsized, and is inexpensive. In this case, the frequency in the start mode can be set as a fixed frequency, and the high frequency voltage of the frequency can be generated without switching the constants of the drive resonance circuit included in the drive signal generation circuit. In addition, it is possible to generate high-frequency voltages of other frequencies by switching the constants of the resonance circuit of the drive signal generation circuit. The main switched device using MOSFET in and the internal capacitance C _ISS the MOSFET is better to use as the capacitance of the kick drive the resonant circuit to a fixed frequency of the. In addition, it is preferable to insert an unsaturated transformer, that is, a current transformer, into the lighting main circuit for feedback, and to use the inductance of the secondary winding as the inductance of the drive resonance circuit.

  In addition, the high-frequency inverter is preferably started in the start-up mode by providing a drive resonance circuit on the low side in the half-bridge inverter and starting the inverter operation by resonance of the drive resonance circuit.

  Thus, according to the above configuration, the high frequency voltage at the time of start-up can be made lower than that at the time of preheating even though it is a simple circuit configuration. Therefore, the moment of brightness of the discharge lamp due to the transient phenomenon at the start-up It is possible to reliably and reliably suppress the occurrence of flicker.

    A lighting device according to a second aspect of the present invention includes: a lighting device main body; and the discharge lamp lighting device according to the first aspect disposed in the lighting device main body.

  In the present invention, the “illuminating device” is a broad concept including all the devices that utilize the light emission of the discharge lamp of the discharge lamp lighting device as defined in claim 1, and includes, for example, a luminaire, a marker lamp, an indicator lamp, This includes advertising lights. The “illuminating device main body” refers to the remaining part of the lighting device excluding the discharge lamp lighting device. The lighting device allows the fluorescent lamp to be lit in a space closed by a member such as a translucent glove or a shade. However, it may be configured to light up while being open to the outside. Furthermore, among the discharge lamp lighting devices, the discharge lamp is preferably arranged in the illuminating device main body, but the other components are arranged at positions separated from the illuminating device main body, and they are connected by wiring. Can be configured.

  And according to this invention, the illuminating device which has an effect | action and effect of the discharge lamp lighting device prescribed | regulated to Claim 1 can be obtained.

    According to the first aspect of the present invention, since the plurality of discharge lamps are sequentially started and lit by sequentially saturating the inductor, an excessive current does not flow to the high-frequency inverter at the time of starting. Therefore, there is no need to change the rating of the circuit component to a higher one, and therefore a discharge lamp lighting device capable of reducing the cost can be provided.

    According to invention of Claim 2, the illuminating device which has the effect of Claim 1 can be provided.

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

1 to 3 show a first embodiment for carrying out a discharge lamp lighting device according to the present invention. FIG. 1 is a circuit diagram, FIG. 2 is a waveform diagram of each part, and FIG. 3 is a resonance characteristic of a drive resonance circuit DRC. 4 is a graph showing the relationship between the frequency f _{PH in} the preheating mode, the frequency f _{ST in} the start mode, and the frequency threshold f _SV when the inductor L1 is saturated. In this embodiment, the discharge lamp lighting device includes a plurality of lighting main circuits OC, a high-frequency inverter HFI, and a DC power source DC, and an input terminal is connected to a commercial AC power source AC.

  <Multiple Lighting Main Circuits OC> Each of the plurality of lighting main circuits OC includes a series circuit of a discharge lamp DL, an inductor L1, a DC cut capacitor C1, and a primary winding wp of a current transformer CT, and further includes a discharge lamp DL. And a resonance capacitor C2 connected in parallel. The plurality of lighting main circuits OC are connected in parallel to each other between output terminals of a high-frequency inverter HFI described later.

  The discharge lamp DL is a fluorescent lamp provided with a pair of hot cathode electrodes E, E. The power supply side terminals of the pair of hot cathode electrodes E and E are connected in series to the lighting main circuit OC.

  The inductor L1 is composed of a choke coil and is configured to saturate at the start. In the plurality of lighting main circuits OC, the inductors L1 may vary in the degree of saturation, and in such cases, the degree of saturation is different.

  The DC cut capacitor C1 is a capacitor having a relatively large capacitance, and prevents the DC component from flowing into the lighting main circuit OC from the high frequency inverter HFI.

  The current transformer CT is a feedback means for controlling the output of the high-frequency voltage of the high-frequency inverter HFI described later by feeding back the current flowing through the lighting main circuit OC. A single primary winding wp and first and second secondary windings ws1, ws2 are provided. The primary winding wp is inserted in series with the lighting main circuit OC.

  The resonant capacitor C2 is connected between the non-power supply side terminals of the pair of hot cathode electrodes E, E of the discharge lamp DL, and forms a series resonant circuit with the inductor L1. For this reason, the series resonant circuit includes a pair of hot cathode electrodes E, E connected in series. Therefore, the hot cathode electrode E is sufficiently heated by the voltage increased by resonance during preheating.

  <High-frequency inverter HFI> The high-frequency inverter HFI includes an inverter main circuit INV and a control circuit CC.

  The inverter main circuit INV is a half-bridge inverter, and includes a pair of switching elements Q1 and Q2, first and second drive circuits DC1 and DC2, a drive resonance circuit DRC, and a starting circuit ST. The pair of switching elements Q1 and Q2 are connected in series to a DC power source DC described later. Each of the pair of switching elements Q1 and Q2 is made of an N-type MOSFET.

  The first drive circuit DC1 includes resistors R1 and R2 and a gate protection circuit GP1, and applies a gate drive signal between the gate and source of the switching element Q1. That is, the series circuit of the resistors R1 and R2 and the gate protection circuit GP1 are connected in parallel and connected between the gate and source of the switching element Q1. The gate protection circuit GP1 includes an anti-series circuit of a plurality of Zener diodes ZD1 and ZD2, absorbs a voltage exceeding a required drive voltage, and protects the gate from the switching elements Q1 and Q2 from being overvoltaged.

  The second drive circuit DC2 includes resistors R3 and R4 and a gate protection circuit GP2 similarly to the first drive circuit DC1. Similarly to the gate protection circuit GP1, the gate protection circuit GP2 includes an anti-series circuit of a plurality of zener diodes ZD3 and ZD4.

Drive resonant circuit DRC consists respective internal capacitances of the pair of switching elements Q1, Q2 C _ISS and first and second secondary winding ws1 current current transformer CT, ws2, and coupling capacitors C3, C4 . The first secondary winding ws1 and the coupling capacitor C3 of the current transformer CT are connected in series and in parallel with the resistor R2 of the first drive circuit DC1. Similarly, the second secondary winding ws2 and the coupling capacitor C4 of the current transformer CT are connected to the second drive circuit DC2.

  The start-up circuit ST is constituted by a series circuit composed of a parallel circuit of resistors R5 and R6, and a series circuit of the gate protection circuit GP1 and resistors R1 and R2, and is connected between output terminals of a DC power source DC described later. ing.

  The control circuit CC is means for controlling the output characteristics of the high-frequency inverter HFI so as to be switched in accordance with the operating state of the discharge lamp DL. The control circuit CC includes first and second control circuits CC1 and CC2, and includes a drive resonance circuit DRC. And the drive resonance frequency is controlled to be a predetermined value. Then, it selectively operates when the operation of the discharge lamp DL is switched to either the preheating mode or the start mode. In addition, switching between the preheating mode and the start mode by the control circuit CC is automatically performed according to a predetermined sequence by a timer not shown.

  The first control circuit CC1 includes a series circuit of an inductor L1, a first switch SW1, and a coupling capacitor C5, and is connected in parallel to the second secondary winding ws2 of the drive resonance circuit DRC. The second control circuit CC2 includes a series circuit of a capacitor C6 and a second switch SW1, and is connected in parallel to a series circuit of the coupling capacitor C4 and the second secondary winding ws2 of the drive resonance circuit DRC. The first and second switches SW1 and SW2 are both connected to the timer via a comparator not shown.

  <DC power supply DC> The DC power supply DC includes a full-wave rectifier circuit FBR and a boost chopper BUT.

  The full-wave rectifier circuit FBR has its AC input terminal constituting the input terminal of the discharge lamp lighting device and is connected to the commercial AC power supply AC. Note that the negative electrode at the DC output end is grounded in terms of high frequency.

  The step-up chopper BUT includes an inductor L3, a switching element Q3, a chopper control circuit CCC, a diode D1, and a smoothing capacitor C7. One end of the inductor L3 is connected to the positive electrode of the DC output end of the full-wave rectifier circuit FBR, and the other end is connected to the switching element Q3. The switching element Q3 is made of a MOSFET and is connected in series with the inductor L3 and then connected between the DC output terminals of the full-wave rectifier circuit FBR. The chopper control circuit CCC generates a gate drive signal for the switching element Q3 and applies it between the gate and the source of the switching element Q3, and a power supply voltage wave induced in the detection winding wa that is magnetically coupled to the inductor L3. The power factor is improved by automatically controlling the oscillation frequency of the gate drive signal according to the high value. The diode D1 and the smoothing capacitor C7 are connected in series and then connected in parallel between the drain and source of the switching element Q3. Then, a DC voltage boosted and smoothed across the smoothing capacitor C7 is output from the boosting chopper BUT.

  Next, circuit operation will be described. That is, when the power switch (not shown) of the discharge lamp lighting device is turned on, the low-frequency AC voltage obtained from the commercial AC power source AC is rectified by the full-wave rectifier circuit FBR of the DC power source DC, boosted by the boost chopper BUT, and smoothed Applied to the high frequency inverter HFI. The high-frequency inverter HFI starts up, operates according to a predetermined time interval in the order of the preheating mode and the start mode, and sequentially outputs a high-frequency voltage corresponding to each operation mode.

In the preheating mode, the first switch SW1 of the control circuit CC is turned on and the second SW2 is turned off. As a result, since it moves away from the resonance point of the drive resonance circuit DRC in the slow phase region of the combined impedance, the oscillation frequency _fPH increases and the high-frequency voltage applied to the discharge lamp DL decreases. Therefore, the hot cathode electrode E is heated to be in a thermoelectron emission state. A timer (not shown) is activated to wait for this, and then shifts to the start mode.

In the start mode, the first and second switches SW1 and SW2 are turned on. For this reason, the inductor L2 of the first control circuit CC1 and the capacitor C6 of the second control circuit CC2 are added to the drive resonance circuit DRC. That is, the inductor L2 is connected in parallel to the inductance viewed from the first and second secondary windings ws1, ws2 of the current transformer CT. The capacitor C6 is connected in parallel to the drive resonance circuit DRC. As a result, since it moves in the direction approaching the resonance point of the drive resonance circuit DRC in the slow phase region of the combined impedance, the oscillation frequency _fST is lowered and the high-frequency voltage applied to the discharge lamp DL is increased. Therefore, the discharge lamp DL starts and lights up.

The lighting main circuit OC is connected in parallel to the output terminal of the high-frequency inverter HFI. Therefore, when the high-frequency inverter HFI outputs a starting voltage, the lighting main circuit OC having the inductor L1 that is most likely to be saturated is associated with the lighting main circuit OC. The inductor L1 is first saturated and the discharge lamp DL belonging to the lighting main circuit OC is turned on. At the moment when the inductor L1 is saturated, as shown in FIG. 2 (a), the DC voltage _VDC instantaneously decreases. As a result, as shown in FIG. 2 (b), the terminal voltage V of the inductor L1 is reduced. _B increases instantaneously, but when the discharge lamp DL is lit, the voltage drops from the time of starting. Subsequently, the inductor L1 of the other lighting main circuit OC is saturated, and the discharge lamp DL connected in series therewith lights up. The voltage change in the inductor L1 at this time is the same as that in FIG. 2B as shown in FIG. 2C, but is delayed for a short time. In this embodiment, lighting of the discharge lamp DL is dimming lighting.

Next, with reference to FIG. 3, illustrating the relationship between the threshold value f _SV saturation frequency of the inductor L1 of the frequency f _PH and during starting mode f _ST and lighting main circuit OC preheat mode. That is, in FIG. 3, the horizontal axis indicates the frequency, the vertical axis indicates the voltage, the frequency f _PH is in the preheating mode, the frequency f _ST is in the start mode, and the frequency f _SV is the frequency at which the inductor L1 is saturated. It is a threshold value. As can be understood from this figure, the frequency threshold f _SV when the inductor L1 is saturated is as close as possible to the frequency f _ST in the start mode between the frequency f _{PH in} the preheating mode and the f _ST in the start mode. It is preferable. In the figure, the frequency f _R is the resonance frequency of the drive resonance circuit DRC.

4 to 6 show a second embodiment for carrying out the discharge lamp lighting device of the present invention, FIG. 4 is a circuit diagram, FIG. 5 is a waveform diagram of an output high-frequency voltage, and FIG. 6 is a diagram of the drive resonance circuit DRC. frequency f _PH resonance characteristics and preheat _mode, the frequency f _ST during startup mode _is a graph showing the relationship between the threshold f _SV of frequency at which the saturation of the frequency f _tO and inductor L1 at startup. In this embodiment, the output characteristics of the high-frequency inverter HFI are different. In the figure, the same parts as those in FIGS. 1 to 3 are denoted by the same reference numerals and description thereof is omitted.

  That is, as shown in FIG. 4, the control circuit CC of the high frequency inverter HFI includes a third control circuit CC3 in addition to the first and second control circuits CC1 and CC2. The third control circuit CC3 is composed of a series circuit of a capacitor C8 and a third switch SW3, and is connected in parallel to the second control circuit CC2. In the figure, symbol TM is a timer. Although a comparator is interposed between the timer TM and the first to third switches SW1, SW2, and SW3, the illustration is omitted.

  The high frequency inverter HFI has output characteristics of a start mode, a preheat mode, and a start mode. These operation modes are performed according to a predetermined time interval in the above order by being controlled by the timer TM. The high frequency inverter HFI sequentially outputs a high frequency voltage corresponding to each operation mode.

In the start-up mode, the first switch SW1 in the first control circuit CC1 in the control circuit CC is turned on, and the second and third switches SW2 and SW3 in the second and third control circuits CC2 and CC3 are Is off. As a result, the inductor L2 is connected in parallel to the inductance viewed from the first and second secondary windings ws1, ws2 of the current transformer CT, and is added to the drive resonance circuit DRC. As a result, the frequency of the resonant output drive resonant circuit DRC, therefore the frequency f _TO startup mode becomes highest in the slow area of the combined impedance of the drive resonant circuit DRC.

Thus, the output high frequency voltage V _TO from the high-frequency inverter HF is significantly lower than the output RF voltage V _PH preheating mode as shown in FIG. This prevents the discharge lamp DL from flickering momentarily. Then, when the start-up is stabilized, the timer TM is controlled to shift to the preheating mode.

In the preheating mode, the first and second control circuits CC1, CC2 of the control circuit CC, the first and second switches SW1, SW2 of the CC2 are turned on, and the third switch SW3 of the third control circuit CC3 is turned off. ing. For this reason, the inductor L2 of the first control circuit CC1 and the capacitor C6 of the second control circuit CC2 are added to the drive resonance circuit DRC. That is, the inductor L2 is connected in parallel to relative inductance L _CT viewed from the first and second secondary winding ws1, ws2 current current transformer CT. The capacitor C8 is connected in parallel to the respective internal capacitances C _ISS of the switching elements Q1, Q2. As a result, apart from the resonance point of the drive resonant circuit DRC in a slow region of combined impedance, since than the frequency f _TO activation mode moves to the position of the resonance point side, is lower oscillation frequency f _PH is, the discharge lamp The high-frequency voltage applied to DL is higher than that in the start-up mode. Therefore, the hot cathode electrode E is heated to be in a thermoelectron emission state. A timer (not shown) is activated to wait for this, and then shifts to the start mode.

In the start mode, the first to third switches SW1, SW2, and SW3 are all turned on. Accordingly, inductor L2 and capacitors C6 and C8 are added to drive resonance circuit DRC. As a result, since it moves in the direction closer to the resonance point of the drive resonance circuit DRC in the slow phase region of the combined impedance of the drive resonance circuit DRC, the oscillation frequency f _ST is lowered and the high frequency voltage applied to the discharge lamp DL is reduced. Get higher. Therefore, the discharge lamp DL starts and lights up.

  The sequential saturation action of the inductor L1 in the plurality of lighting main circuits OC is the same as that in the first embodiment shown in FIG.

    FIG. 7 is a conceptual cross-sectional view showing a ceiling light as an embodiment for implementing the illumination device of the present invention. In the figure, 11 is a chassis, 12 is a reflector, 13A and 13B are annular fluorescent lamps, 14 is a shade, 15 is a high-frequency lighting device, and 16 is a hooking ceiling adapter.

  The chassis 11 is formed by press-molding a metal plate, a through hole is formed at the center, and a standing edge 11a (in the drawing, facing downward) is formed at the periphery.

  The reflector 12 is formed by molding a white synthetic resin and is disposed on the lower surface of the chassis 11.

  The annular fluorescent lamp 13A has a tube diameter of 16.5 mm, an outer ring diameter of 373 mm, an inner ring diameter of 340 mm, and a rated lamp power of 34 W / 48 W. The annular fluorescent lamp 13B has a tube diameter of 16.5 mm, an annular outer diameter of 225 mm, an annular inner diameter of 192 mm, and a rated lamp power of 20 W / 28 W. These annular fluorescent lamps 13A and 13B are integrally attached to and detached from a predetermined place of the reflector by a single lamp holder (not shown), and at the same time, required connection to the high-frequency lighting device 15 is performed. Yes.

  The shade 14 is formed of milky acrylic resin or the like in a thin dome shape to cover the chassis 11, the reflector 12, the annular fluorescent lamps 13 </ b> A and 13 </ b> B, and the opening edge 14 a is fitted inside the standing edge 11 a of the chassis 11. It is detachably fixed in the state.

  The high-frequency lighting device 15 has the circuit configuration shown in FIG. 1 or FIG. 4, energizes the annular fluorescent lamps 13 </ b> A and 13 </ b> B to light up, and is disposed in a space formed between the chassis 11 and the reflection plate 12. Has been. In addition, although the high frequency lighting device 15 seems to be divided into two in the drawing, it has an integrated configuration.

  The hook ceiling adapter 16 receives AC power from the ceiling and supplies electric energy to the ceiling light, and functions to attach the ceiling light to the ceiling. The hooking sealing cap mechanism 16a and an electrical connector and a hooking claw, which are not shown, are provided.

  The hooking sealing cap mechanism 16a is electrically and mechanically connected to the hooking sealing body by being detachably hooked to an embedded or exposed hooking sealing body (not shown) disposed on the ceiling. Is done.

  The electrical connector is connected to the hooking ceiling cap mechanism via an insulated wire, and is connected to a power receiving plug disposed on the reflecting plate 12, thereby forming a power feeding path to the ceiling light.

  The hooking claw protrudes from the side surface of the hooking ceiling adapter 16 so as to be able to advance and retreat, and is locked in a locking hole that opens on the side surface of the cylindrical hole 12a formed in the center of the reflecting plate 12.

The circuit diagram which shows the 1st form for implementing the discharge lamp lighting device of this invention Similarly, the waveform of each part Similarly, a graph showing the relationship between the resonance characteristics of the drive resonance circuit DRC, the frequency f _{PH in} the preheating mode, the frequency f _{ST in} the start mode, and the frequency threshold f _SV when the inductor L1 is saturated. The circuit diagram which shows the 2nd form for implementing the discharge lamp lighting device of this invention Similarly, output high-frequency voltage waveform diagram Similarly, a graph showing the relationship between the resonance characteristics of the drive resonance circuit DRC, the frequency f _PH during the preheating mode, the frequency f _ST during the start mode, the frequency f _TO during the start-up, and the threshold value f _SV when the inductor L1 is saturated. The conceptual sectional view showing the ceiling light as one form for carrying out the lighting device of the present invention

Explanation of symbols

  CC ... Control circuit, DC ... DC power supply, DL ... Discharge lamp, HFI ... High frequency inverter, INV ... Inverter main circuit, L1 ... Inductor saturated at start-up OC ... Lighting main circuit

Claims (2)

A plurality of lighting main circuits connected in parallel, including a series circuit of a discharge lamp and an inductor saturated at start-up;
A common high-frequency inverter having at least a preheating mode and a starting mode in output characteristics and outputting a high-frequency voltage to a plurality of lighting main circuits to energize a discharge lamp;
A DC power source connected to the input end of a common high-frequency inverter;
In the start mode of the high-frequency inverter, the inductor of one of the plurality of lighting main circuits is saturated first, and the discharge lamp of the lighting main circuit is lit, and then the remaining lighting main circuit A discharge lamp lighting device characterized in that an inductor of a circuit is saturated and a discharge lamp of the lighting main circuit is sequentially lit. A lighting device body;
The discharge lamp lighting device according to claim 1, which is disposed in the lighting device body;
An illumination device comprising:

Images