JP5227112B2 - Electrodeless discharge lamp lighting device and lighting apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting device capable of securing substantial startup voltage by restraining drop of output voltage of a direct-current power supply circuit at startup without giving stress on components constituting a circuit, and further, preventing occurrence of spark at re-startup after instantaneous voltage drop, and to provide a lighting fixture using the same. <P>SOLUTION: The lighting device is provided with a first startup preparation period T1 started at least before an output voltage Vdc of a direct-current power supply circuit 1 reaches a given value, during which time, a high-frequency power supply circuit 2 impresses on an induction coil 3 a high-frequency voltage Vx of a level giving a load on the direct-current power supply circuit 1 so that an output voltage Vdc of the direct-current power supply circuit 1 does not exceed a given value, and a second startup preparation period T2 in which the high-frequency power supply circuit 2 impresses on the induction coil 3 a high-frequency voltage Vx larger than in the first startup preparation period T1, and that, a high-frequency voltage Vx as large as possible within a range in which the electrodeless discharge lamp 4 does not start up. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an electrodeless discharge lamp lighting device and a lighting fixture using the same.

  Conventionally, a transparent spherical glass bulb or a spherical glass bulb coated with a phosphor on the inner wall surface has been filled with a discharge gas (for example, mercury vapor or rare gas) such as inert gas or metal vapor. An induction coil is arranged in the vicinity of the discharge lamp, and a high frequency current of several tens of kHz to several hundreds of MHz is passed through the induction coil, thereby generating a high frequency electromagnetic field in the induction coil and supplying high frequency power to the electrodeless discharge lamp. There is known an electrodeless discharge lamp lighting device that generates high-frequency plasma current in a glass bulb of an electrodeless discharge lamp to generate ultraviolet light or visible light. An example of such an electrodeless discharge lamp lighting device is disclosed in Patent Document 1.

  This electrodeless discharge lamp lighting device includes a DC power supply circuit that creates a predetermined DC output from an AC output supplied from an AC power supply, and converts the DC output of the DC power supply circuit into a high-frequency output in the vicinity of the electrodeless discharge lamp. A high-frequency power supply circuit that supplies the arranged induction coil, and a detection circuit detects a starting voltage at the time of starting, and a control circuit performs feedback so that a desired starting voltage is applied to the induction coil. Therefore, the drive circuit of the high frequency power supply circuit changes the operating frequency in accordance with the control output obtained by adding the first control output output from the starting circuit and the second control output output from the control circuit. As a result, the electrodeless discharge lamp can be stably started and lit by the starting circuit, and after the lighting, feedback control is performed by the control circuit, so that the high frequency power applied to the induction coil is excessively increased or It can be prevented from decreasing.

  By the way, since an electrodeless discharge lamp does not have an electrode inside, it is necessary to apply a starting voltage higher than that of a fluorescent lamp or the like to the induction coil when starting the electrodeless discharge lamp. For this reason, an electrodeless discharge lamp lighting device capable of applying a high starting voltage with low loss by sharpening resonance at the time of starting the electrodeless discharge lamp (that is, setting the Q value of the resonance circuit high) is provided. Need to design. Here, the sharp resonance means that the starting voltage greatly fluctuates with respect to fluctuations of minute frequencies and parameters of elements constituting the circuit.

  In addition, the electrodeless discharge lamp at the start is an inductor load, and compared with other discharge lamps having electrodes such as a fluorescent lamp, a large amount of power is consumed in a state where the lamp is not particularly lit (starting or no load). There is a problem of need. For example, the power consumption of the high frequency power supply circuit that receives the output of the DC power supply circuit and outputs the high frequency output at no load may reach twice or more the power consumption during normal lighting. However, the DC power supply circuit in the electrodeless discharge lamp lighting device is generally designed based on the load state during normal lighting in consideration of the size and cost of the device. Therefore, at the time of start-up, particularly when the lighting is performed in a dark place or when there is no load, the voltage regulation of the DC power supply circuit is not sufficient due to the heavy load, and the output voltage of the DC power supply circuit is lowered. As a result, a sufficient starting voltage cannot be ensured, and there is a possibility that problems such as the electrodeless discharge lamp not lighting up may occur.

In order to solve the above problems, the high frequency voltage is not suddenly applied to the induction coil at the start, but a predetermined output high frequency voltage is set as a preliminary output before the start (hereinafter, this period is referred to as “start preparation period”). A configuration to be applied to the induction coil is disclosed in Patent Document 2. This configuration suppresses steep load fluctuations at the start by giving an appropriate load to the high frequency power supply circuit, and obtains an effect of preventing an overshoot of the high frequency voltage applied to the induction coil at the start. At the same time, since the control of the DC power supply circuit can easily follow the load fluctuation, it is possible to obtain the effect of stably supplying the DC voltage to the high-frequency power supply circuit by suppressing the decrease in the output voltage of the DC power supply circuit.
JP 2005-158464 A Japanese Patent Laid-Open No. 2005-158459

  However, in order to sufficiently obtain the effect of suppressing the decrease in the output voltage of the DC power supply circuit in the latter conventional example, the voltage applied to the induction coil during the start-up preparation period is as large as possible within the range where the electrodeless discharge lamp is not lit. There is a need to. For example, as shown in FIG. 11, when the voltage applied to the induction coil in the start preparation period is small, a steep load change occurs at the start as in the case where the start preparation period is not provided. This is because there is a possibility that the output voltage of the LED lamp will decrease, and a sufficient starting voltage cannot be ensured and the electrodeless discharge lamp will not light. On the other hand, as shown in FIG. 12, when the voltage applied to the induction coil in the start preparation period is increased, the output voltage of the DC power supply circuit is reduced at the start because no sharp load fluctuation occurs at the start. It is possible to obtain the effect of suppressing the above and ensuring a sufficient starting voltage.

  However, if a high high-frequency voltage is applied to the induction coil when starting the start-up preparation period, the start-up of the DC power supply circuit is delayed, and a high high-frequency voltage is applied for a certain period in the start-up preparation period until the output voltage of the DC power supply circuit stabilizes. Therefore, there is a problem in that a great deal of stress is applied to the components constituting the circuit. Further, since the Q value of the resonance circuit is large, there is a problem in that overshoot occurs when a high frequency voltage is applied to the induction coil in order to start the start preparation period, and stress is applied to the components constituting the circuit. . In order to avoid this, as shown in FIG. 13, if the start-up preparation period is provided after starting the apparatus after a certain period, the rise of the DC power supply circuit is improved, but the high-frequency power supply circuit and the induction coil are used. Since no power is consumed, the load becomes light and the output voltage of the DC power supply circuit becomes higher than a predetermined voltage. Thereafter, until the start preparation period starts, the output voltage of the DC power supply circuit is maintained at a high level, and there is a problem that stress is applied to the components constituting the circuit.

  In addition, an AC power supply that supplies an AC voltage to a DC power supply circuit may have an output that is reduced for a short period of time that is less than several hundred ms, that is, an instantaneous power reduction. In this case, restart is started after the momentary power failure, but since the control circuit is not reset because it is performed immediately after the lighting operation before the momentary power failure, the high frequency applied to the induction coil at the time of restart. The voltage may rise from a high voltage and spark may occur.

  The present invention has been made in view of the above points, and it is possible to suppress a decrease in the output voltage of the DC power supply circuit at the start-up and ensure a sufficient start-up voltage without applying stress to the components constituting the circuit. Another object of the present invention is to provide an electrodeless discharge lamp lighting device capable of preventing the occurrence of sparks upon restart after instantaneous power failure and a lighting fixture using the same.

In order to achieve the above object, the invention of claim 1 includes a DC power supply circuit that converts an AC voltage from an AC power supply into a DC voltage and outputs it, and one or more switching elements and a resonance circuit that are switched at a high frequency. A high-frequency power supply circuit that converts the output voltage of the DC power supply circuit into a high-frequency voltage and supplies the high-frequency voltage to an induction coil disposed close to the electrodeless discharge lamp; a drive circuit that outputs a drive signal for switching the switching element; and a drive circuit And a starting circuit for starting the electrodeless discharge lamp by gradually increasing the voltage applied to the induction coil by changing the frequency of the drive signal, and the starting circuit is of a size that does not start the electrodeless discharge lamp. After a start preparation period in which a high frequency voltage is applied to the induction coil, and a start period in which a high frequency voltage having a magnitude capable of starting the electrodeless discharge lamp is applied to the induction coil. The polar discharge lamp is started, and the start preparation period includes at least a first start preparation period and a second start preparation period provided after the first start preparation period, and the first start preparation period is at least DC. It starts until the output voltage of the power supply circuit reaches a predetermined value, and during this period, the high frequency power supply circuit induces a high frequency voltage that gives a load to the DC power supply circuit so that the output voltage of the DC power supply circuit does not exceed the predetermined value. In the second start-up preparation period, the high-frequency power supply circuit applies a high-frequency voltage that is greater than the high-frequency voltage in the first start-up preparation period and as large as possible to the extent that the electrodeless discharge lamp does not start up. , Detecting an abnormality in power supply from the high-frequency power supply circuit to the induction coil, and at the time of abnormality, at least a first start preparation period, a second start preparation period, a start period The a protection circuit that sequentially repeated in the protection circuit is characterized in that the output voltage of the DC power supply circuit decreased after the abnormality detection to start first starting time to prepare to rise to at least a predetermined value again.

According to a second aspect of the present invention, in the first aspect of the invention, the starting circuit applies a high-frequency field discharge voltage for generating a high-frequency field discharge in the second start preparation period to the induction coil until the high-frequency field discharge is generated. The drive circuit is controlled as described above, and the drive circuit is controlled to apply a high-frequency electromagnetic field discharge voltage for generating a high-frequency electromagnetic field discharge to the induction coil during the starting period.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the start circuit gradually increases the voltage applied to the induction coil during the transition from the first start preparation period to the second start preparation period. The drive circuit is controlled.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the starting circuit gradually increases the voltage applied to the induction coil during the transition from the second starting preparation period to the starting period. And controlling the drive circuit.

The invention of claim 5, at least a fixture main body for holding an electrodeless discharge lamp, an induction coil disposed close to the electrodeless discharge lamp, according to claim 1 or any one of 4 for supplying high frequency power to the induction coil And an electrodeless discharge lamp lighting device as described above.

According to the first aspect of the present invention, since the steep load fluctuation at the time of shifting to the start period can be suppressed by providing the second start preparation period, the decrease in the output voltage of the DC power supply circuit at the start can be suppressed. And a sufficient starting voltage can be secured. In addition, by providing the first start preparation period, it is possible to prevent the output voltage of the DC power supply circuit from overshooting and to prevent stress from being applied to the components constituting the circuit. Further, even when the control circuit or the like is not reset at the time of restart after the AC power supply is instantaneously reduced, the first start preparation period, the second start preparation period, and the high frequency voltage applied to the induction coil Is increased stepwise from the low voltage, so that it is possible to prevent the occurrence of sparks at the time of restart after an instantaneous low power . Furthermore, in situations where it is difficult to turn on the electrodeless discharge lamp, such as in the dark or at low temperatures, it is possible to prevent a high voltage from being applied to the induction coil for a long time without turning on the electrodeless discharge lamp. In this case, it is possible to prevent the output voltage of the DC power supply circuit from becoming high, so that it is possible to prevent stress from being applied to the components constituting the circuit .

According to the invention of claim 2 , since the high frequency electromagnetic field discharge is generated in the start period after the high frequency field discharge is generated in the second start preparation period, the electrodeless discharge lamp is started without providing the start preparation period. The startability can be improved as compared with the case. In addition, since the transition to the start period after generating the high frequency electric field discharge, the high frequency electromagnetic field discharge can be generated immediately and the start period during which the high voltage is applied to the induction coil can be shortened. It is possible to reduce stress on the parts to be performed .
According to the third aspect of the present invention, it is possible to prevent an overshoot from occurring in the voltage applied to the induction coil due to a steep load variation, and it is possible to reduce stress on the components constituting the circuit.

According to the fourth aspect of the present invention, it is possible to prevent an overshoot from occurring in the voltage applied to the induction coil due to a steep load variation, and it is possible to reduce stress on the components constituting the circuit.

According to the invention of claim 5 , it is possible to realize a lighting fixture having the effect of the invention of any one of claims 1 to 4 .

(Embodiment 1)
Hereinafter, Embodiment 1 of the electrodeless discharge lamp lighting device according to the present invention will be described with reference to the drawings. In the present embodiment, as shown in FIG. 1, a DC power supply circuit 1 that creates a desired DC output from an AC output of a commercial power supply AC that is an AC power supply, and a DC output of the DC power supply circuit 1 are converted into a high-frequency output. The high frequency power supply circuit 2 supplied to the induction coil 3 disposed in the vicinity of the electrodeless discharge lamp 4 and the output voltage (applied voltage to the induction coil 3) Vx of the high frequency power supply circuit 2 when the electrodeless discharge lamp 4 is started are gradually increased. A starting circuit 5 for starting the electrodeless discharge lamp 4, a voltage detection circuit 7 for detecting the output voltage Vx of the high frequency power supply circuit 2, a current detection circuit for detecting a resonance current flowing in a resonance circuit 21 described later, With reference to the detection current of the detection circuit, the drive circuit 20 to be described later is controlled so that the output voltage Vx of the high frequency power supply circuit 2 becomes a desired level, and the frequencies (operation frequencies) finv of the drive signals VDH and VDL are changed. And a control circuit 6.

  The DC power supply circuit 1 includes a rectifier circuit 10 that rectifies an AC output of a commercial power supply AC, a well-known booster that includes a drive circuit 11 that drives an inductor L1, a diode D1, a switching element Q1, a smoothing capacitor C1, and a switching element Q1. It consists of a chopper circuit and outputs a DC voltage Vdc.

  The high-frequency power supply circuit 2 includes a pair of switching elements Q2 and Q3 connected in series between the output terminals of the DC power supply circuit 1, and a resonance circuit 21 including an inductor Ls and capacitors Cp and Cs is connected to the low-side switching element Q3. By switching the pair of switching elements Q2 and Q3 composed of field effect transistors alternately by the drive signals VDH and VDL of the rectangular wave pulse output from the drive circuit 20, the so-called half-bridge type inverter circuit is formed. A high frequency output is supplied to the induction coil 3 via the resonance circuit 21. The driving signal VDH for driving the switching element Q2 and the driving signal VDL for driving the switching element Q3 have a phase difference of about 180 degrees.

  Capacitors Ccp and Cinv are inserted between the drive circuits 11 and 20 of the DC power supply circuit 1 and the high-frequency power supply circuit 2 and the circuit ground, respectively. The capacitors Ccp and Cinv supply power from the commercial power supply AC. The time from the start of power supply to the start of the drive circuits 11 and 20 is set.

  An induction coil 3 formed by winding a plurality of conductive wires is connected to the output end of the resonance circuit 21, and the electrodeless discharge lamp 4 is disposed close to the induction coil 3. As shown in FIG. 8A, the electrodeless discharge lamp 4 includes a transparent substantially spherical bulb 40 in which a discharge gas (for example, mercury and a rare gas) such as an inert gas or a metal vapor is sealed, and a bulb 40. And a substantially cylindrical cavity 41 protruding inward of the valve 40, and a coupler 8 that holds the valve 40 and positions the induction coil 3 with respect to the valve 40 is inserted into the cavity 41. .

  As illustrated in FIG. 8B, the coupler 8 includes a bobbin 80 that holds the induction coil 3, and a substantially cylindrical core 81 that is housed inside the bobbin 80. The core 81 is made of, for example, Mn—Zn ferrite having good high-frequency magnetic characteristics, and is held by a radiator (not shown) formed of a metal material such as aluminum. The heat generated by the core 81 is thrown away to the pedestal portion 82 via the heat radiating body. As shown in the figure, both the present embodiment and each of the embodiments described later are housed in a case 83 and electrically connected to the induction coil 3 via the output line 84 to thereby generate a high frequency output. 3 is supplied.

  The voltage detection circuit 7 includes a rectifying diode, a voltage dividing resistor, a smoothing capacitor, and the like, and outputs a detection voltage Vxs that is a DC voltage corresponding to the output voltage Vx of the high-frequency power supply circuit 2 to the starting circuit 5. The current detection circuit includes a detection resistor Rd connected between the low-side switching element Q3 constituting the high-frequency power supply circuit 2 and the circuit ground, and the high-frequency current flowing through the switching element Q3 (resonance current flowing through the resonance circuit 21). Is output to the control circuit 6.

  The starter circuit 5 connects an input resistor and a feedback resistor to the operational amplifier OP1 and a capacitor C2 that is charged via the temperature-sensitive resistor R1 by the operating voltage Vd obtained by stepping down and stabilizing the output voltage Vdc of the DC power supply circuit 1. An error amplifier that amplifies the difference between the voltage Vc across the capacitor C2 and the detection voltage Vxs of the voltage detection circuit 7, a voltage dividing resistor R2 connected in parallel with the capacitor C2, and a resistor connected in parallel with the capacitor C2. A series circuit of R3 and a discharge switch SW1 and a series circuit of a resistor R4 and a discharge switch SW2 are provided, and the output voltage Vf gradually increases according to the time constant of the charging circuit composed of the resistor R1 and the capacitor C2. To do. The output voltage Vf of the starting circuit 5 is input to the drive circuit 20. In this embodiment, the on / off switching of the switches SW1 and SW2 is controlled by a switch control circuit (not shown) made of, for example, a microcomputer, and is turned on / off every predetermined time after the apparatus is activated. It is preset to switch.

  The control circuit 6 is configured by connecting an input resistor or the like to the operational amplifier OP2, and an error amplifier (differential amplifier) that amplifies the difference between the reference voltage Vref and the detection voltage VRd of the current detection circuit, and the output of the operational amplifier OP2 via the resistor. And a diode D3 having a cathode connected to the terminal. In the operational amplifier OP2, the reference voltage Vref is input to the non-inverting input terminal, and a delay circuit including a parallel circuit of a resistor R5 and a capacitor C3 is connected between the inverting input terminal and the output terminal. Further, the cathode of the diode D2 is connected to the output terminal of the operational amplifier OP1 constituting the error amplifier of the starting circuit 5 through a resistor, and the anodes of these two diodes D2 and D3 are parallel to the input terminal of the drive circuit 20. It is connected. Here, a constant voltage (input terminal voltage) is applied to the input terminal of the drive circuit 20, and the output voltage of the error amplifier of the starting circuit 5 (the output voltage Vf of the operational amplifier OP 1) is greater than the input terminal voltage of the drive circuit 20. Is smaller, the first control current Isw corresponding to the potential difference flows and the output voltage of the error amplifier of the control circuit 6 (the output voltage Vn of the operational amplifier OP2) is the input terminal voltage of the drive circuit 20. When it is smaller, the diode D3 becomes conductive, and the second control current Ifb corresponding to the potential difference flows. Therefore, the magnitude of the control current Io flowing out from the input terminal of the drive circuit 20 is the sum of the first and second control currents Isw and Ifb.

  On the other hand, the drive circuit 20 includes an oscillator, and changes the oscillation frequency of the oscillator in accordance with the control current Io flowing from the input terminal to the output terminal of the start circuit 5 and the control circuit 6, and is driven in proportion to the control current Io. The frequency (operating frequency) finv of the signals VDH and VDL is increased or decreased. Therefore, the operating frequency finv of the drive circuit 20 decreases as the output voltages Vf and Vn of the error amplifiers of the starting circuit 5 and the control circuit 6 increase.

  Hereinafter, the operation of the present embodiment will be described with reference to FIGS. FIG. 2 shows the output characteristics of the high frequency power supply circuit 2 with the horizontal axis representing the operating frequency finv of the drive circuit 20 and the vertical axis representing the output voltage Vx of the high frequency power supply circuit 2. The curve (b) represents the characteristics when the electrodeless discharge lamp 4 is lit (during lighting). FIG. 3 shows a time chart in which the horizontal axis represents time, and the vertical axis represents the operating frequency finv of the drive circuit 20, the output voltage Vx of the high frequency power supply circuit 2, and the output voltage Vdc of the DC power supply circuit 1 from the top. .

  When power supply from the commercial power supply AC to the DC power supply circuit 1 is started and the switches SW1 and SW2 are turned on (time t1), the output voltage Vdc of the DC power supply circuit 1 rises and the output voltage Vf of the starter circuit 5 operates. A voltage value obtained by dividing the voltage Vd by the resistors R1, R2, R3, and R4 is obtained. The frequencies of the drive signals VDH and VDL output from the drive circuit 20 at this time (the operating frequency of the high-frequency power supply circuit 2) finv are initial values (starting start frequencies) f2 (see FIG. 3), and the starting start frequency f2 is As shown in FIG. 2, the frequency is set sufficiently higher than the resonance frequency f0 at no load, and the output voltage Vx of the high-frequency power supply circuit 2 when the operating frequency finv = f2 is suppressed to a low voltage (see FIG. 3). ). The period in which both the switches SW1 and SW2 are on continues until time t2, and this period becomes the first start preparation period T1.

  The first start preparation period T1 is started until the output voltage Vdc of the DC power supply circuit 1 reaches a predetermined voltage (a stable voltage when the electrodeless discharge lamp 4 is lit). In this period, the DC power supply circuit 1 The high frequency voltage Vx of a magnitude that gives a load to the DC power supply circuit 1 is applied to the induction coil 3 so that the output voltage Vdc does not exceed a predetermined voltage.

  Next, at time t2, the switch SW2 is turned off, and the output voltage Vf becomes a voltage value obtained by dividing the operating voltage Vd by the resistors R1, R2, and R3. Since the output voltage Vf at this time is larger than the output voltage Vf in the first start preparation period T1, the operating frequency finv is smaller than the start start frequency f2 as the output voltage Vf increases as shown in FIG. f3, and the output voltage Vx of the high-frequency power supply circuit 2 is larger than the output voltage Vx in the first start preparation period T1 and is as high as possible within a range where the electrodeless discharge lamp 4 does not start (see FIG. 3). The period in which the switch SW2 is off and the switch SW1 is on continues until time t3, and this period is the second start preparation period T2.

  Next, at time t3, the switch SW1 is also turned off, and the output voltage Vf becomes a voltage value obtained by dividing the operating voltage Vd by the resistors R1 and R2. Since the output voltage Vf at this time becomes larger than the output voltage Vf in the second preparation period T2, the operating frequency finv becomes f1 smaller than f3 as the output voltage Vf increases as shown in FIG. The output voltage Vx of the power supply circuit 2 is higher than the output voltage Vx in the second start preparation period T2 (see FIG. 3). The period after time t3 is the starting period T3. During this period, the output voltage Vx of the high-frequency power supply circuit 2 reaches the starting voltage, and at time t4, the electrodeless discharge lamp 4 is turned on and the characteristics change from curve A to curve B. As a result, the output voltage Vx decreases and the lighting period T4 starts (see FIG. 3).

  On the other hand, in the control circuit 6, the output current (resonance current) of the high-frequency power supply circuit 2 is substantially zero at time t1, so that the detection voltage VRd is also substantially zero, and the operational amplifier OP2 constituting the error amplifier of the control circuit 6 The output voltage Vn becomes an initial value (maximum value) corresponding to the reference voltage Vref. As the time elapses, the output current of the high-frequency power supply circuit 2 increases and the detection voltage VRd also increases. However, the output voltage Vn of the operational amplifier OP2 does not decrease from the initial value due to the function of the delay circuit including the resistor R5 and the capacitor C3. The second control current Ifb of the control circuit 6 is also substantially zero. Therefore, while the output voltage Vn of the operational amplifier OP2 is higher than the input terminal voltage of the drive circuit 20, the second control current Ifb is substantially zero, and the control output Io substantially coincides with the first control output Isw. The feedback control of the operating frequency finv by the control circuit 6 is not performed, and only the control for gradually decreasing the operating frequency finv by the first control current Isw output from the starting circuit 5 is performed.

  Here, the delay time of the delay circuit in the control circuit 6 is set to the time required for the electrodeless discharge lamp 4 to start and light (elapsed time from time t1 to t3), and after time t3, the operational amplifier OP2 Since the second control current Ifb flows in accordance with the potential difference between the output voltage Vn of the drive circuit 20 and the input terminal voltage of the drive circuit 20, the operating frequency finv increases as the control current Io increases, and the output voltage Vx of the high-frequency power supply circuit 2 decreases. Will do. Note that the operating frequency finv of the drive circuit 20 is the frequency when the resonance current matches the desired level when the electrodeless discharge lamp 4 is rated lighting, that is, the frequency when the detection voltage VRd matches the reference voltage Vref (rated lighting). Frequency). Thereafter, the control circuit 6 feedback-controls the operating frequency finv of the drive circuit 20 so that the resonance current (output current of the high-frequency power supply circuit 2) matches a desired level determined by the reference voltage Vref. Make it light stably.

  As described above, since the second start preparation period T2 that is as large as possible within the range in which the output voltage Vx of the high-frequency power supply circuit 2 does not start is provided before the start period T3, the process proceeds to the start period T3. A steep load fluctuation at the time of starting can be suppressed, and a sufficient starting voltage can be secured by suppressing a decrease in the output voltage Vdc of the DC power supply circuit 1 at the time of starting. Also, the high-frequency voltage of a magnitude that starts until the output voltage Vdc of the DC power supply circuit 1 reaches a predetermined voltage and gives a load to the DC power supply circuit 1 so that the output voltage Vdc of the DC power supply circuit 1 does not exceed a predetermined value. Since the first start preparation period T1 for applying Vx to the induction coil 3 is provided, the output voltage Vdc of the DC power supply circuit 1 can be prevented from overshooting, and stress is applied to the components constituting the circuit. Can be prevented.

  Temporarily, no voltage is applied to the induction coil 3 until the time t2 after the power supply from the commercial power supply AC to the DC power supply circuit 1 is started, that is, the second start without providing the first start preparation period T1. If only the preparation period T2 is provided, the voltage applied to the induction coil 3 is substantially zero between the time t1 and the time t2, so that the load is light and the output voltage Vdc of the DC power supply circuit 1 is not consumed. For this reason, the output voltage Vdc of the DC power supply circuit 1 exceeds a predetermined value when the electrodeless discharge lamp 4 is turned on, resulting in an overshoot, and a great deal of stress is applied to the components constituting the circuit. On the other hand, in the present embodiment, since the first start preparation period T1 is provided as described above, the voltage supply to the DC power supply circuit 1 is started until the second start preparation period T2 is started. The output voltage Vdc of the DC power supply circuit 1 can be prevented from overshooting in the meantime, and no stress is applied to the components constituting the circuit.

  Furthermore, in the present embodiment, even when the control circuit 6 or the like is not reset at the time of restart after the commercial power supply AC is instantaneously low, the first start preparation period T1 and the second start preparation period Since the high-frequency voltage Vx applied to T2 and the induction coil 3 is increased stepwise from a low voltage, it is possible to prevent the occurrence of sparks at the time of restart after an instantaneous low power.

  In addition, at the time of transition from the first start preparation period T1 to the second start preparation period T2 and at the time of transition from the second start preparation period T2 to the start period T3, the output voltage is increased by charging the capacitor C2. Vf gradually increases, and the operating frequency finv gradually decreases along with this, so that the output voltage Vx of the high-frequency power supply circuit 2 gradually increases. For this reason, it is possible to prevent an overshoot from occurring in the output voltage Vx of the high-frequency power supply circuit 2 due to a steep load change at the time of transition, and it is possible to reduce stress on the components constituting the circuit.

(Embodiment 2)
Hereinafter, Embodiment 2 of the electrodeless discharge lamp lighting device according to the present invention will be described with reference to the drawings. However, since the basic configuration of this embodiment is the same as that of the first embodiment, common portions are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, as shown in FIG. 4, an abnormality in power supply from the high-frequency power supply circuit 2 to the induction coil 3 is detected, and the first start preparation period T1, the second start preparation period T2, The protection circuit 9 is characterized in that it includes a period T3 and a protection period T5 in which the operation of the DC power supply circuit 1 and the high frequency power supply circuit 2 is stopped in order.

  In this embodiment, the start timing control circuit 50 is used to switch the switches SW1 and SW2 in the start circuit 5. The start timing control circuit 50 is connected to the drive circuit 11 of the DC power supply circuit 1 and the drive circuit 20 of the high-frequency power supply circuit 2, and when power is supplied to the drive circuits 11 and 20, the switches SW1 and SW1 are switched after a certain period of time. A control signal for switching off SW2 is applied to each of the switches SW1 and SW2. Here, a control signal is directly given to the switch SW1, but a control signal is given to the switch SW2 via a delay circuit including a diode D4, a resistor R7, and a capacitor C5. Therefore, the switch SW2 is controlled to be turned off after a predetermined time has elapsed after the switch SW1 is turned off, and the constants of the resistor R7 and the capacitor C5 are appropriately set so that the first start preparation period T1, the second The start preparation period T2 and the start period T3 can be set.

  In the protective circuit 9, the detection voltage Vxs of the voltage detection circuit 7 is input to the non-inverting input terminal and the reference voltage Vb is input to the inverting input terminal, and the resistor R6 connected to the output terminal of the operational amplifier OP3. And a delay circuit composed of a capacitor C4, and a stop circuit 90 that receives the voltage across the capacitor C4 and stops the operation of the DC power supply circuit 1 and the high-frequency power supply circuit 2 according to the voltage. The reference voltage Vb is set according to the high-frequency voltage Vx in the start period T3, and is set so that the output voltage of the operational amplifier OP3 becomes high level when the start period T3 is entered. The stop circuit 90 gives a control signal to the drive circuit 11 of the DC power supply circuit 1 and the drive circuit 20 of the high-frequency power supply circuit 2 when the voltage across the input capacitor C4 exceeds a predetermined voltage, and operates each circuit for a certain period. Stop. The control signal is also supplied to the start timing control circuit 50, and the start timing control circuit 50 is reset when the control signal is supplied.

  Hereinafter, the operation of the present embodiment will be described with reference to FIG. First, when the power supply from the commercial power supply AC to the DC power supply circuit 1 is started, the electrodeless discharge is performed through the first start preparation period T1, the second start preparation period T2, and the start period T3 as in the first embodiment. Control for starting the electric lamp 4 is performed. In the present embodiment, since the detection voltage Vxs of the voltage detection circuit 7 is applied to the start circuit 5 and feedback control is performed, even if the output voltage Vdc of the DC power supply circuit 1 decreases during the start period T3, the operating frequency By reducing finv from f1 to f4, it is possible to prevent the high-frequency voltage Vx from being lowered and to keep it constant (see FIGS. 2 and 5).

  Here, when there is an abnormality such as no load in which the electrodeless discharge lamp 4 is not mounted, a high voltage is continuously applied without the electrodeless discharge lamp 4 being lit, and the circuit is adversely affected. It is desirable to stop the operation of the DC power supply circuit 1 and the high frequency power supply circuit 2 after a certain period of time elapses. Therefore, in the present embodiment, charging of the capacitor C4 of the protection circuit 9 starts when the start period T3 starts, and when the voltage across the capacitor C4 exceeds a predetermined voltage after a certain period, the stop circuit 90 is connected to each drive circuit 11, 20, the control signal is given to the start timing control circuit 50 to stop the operation of the DC power supply circuit 1 and the high frequency power supply circuit 2, and the protection period T5 is started. After the transition to the protection period T5, the operation of the DC power supply circuit 1 and the high-frequency power supply circuit 2 is started again after a certain period determined by the stop circuit 90, and the above-described series of operations is repeated. Here, in the protection period T5, since the operation of the DC power supply circuit 1 is stopped, the output voltage Vdc decreases. In this embodiment, the first start preparation is performed before the output voltage Vdc rises to at least a predetermined voltage. The period T1 is started again. In the present embodiment, when the above-described series of operations is repeated three times, the function of the stop circuit 90 determines that there is no load, and the operations of the DC power supply circuit 1 and the high-frequency power supply circuit 2 are completely stopped to protect the circuit. Is done.

  As described above, an abnormality in power supply from the high-frequency power supply circuit 2 to the induction coil 3 is detected, and the DC power supply circuit 1 and the high-frequency power supply circuit 2 are stopped at the time of abnormality, and then the first start preparation period T1 and second Since the protection circuit 9 for repeating the start preparation period T2 and the start period T3 is provided again, in the situation where it is difficult to turn on the electrodeless discharge lamp 4 such as in a dark place or at a low temperature, the induction coil remains unlit. 3 can be prevented from being applied with a high voltage for a long time, and stress can be prevented from being applied to the components constituting the circuit. Further, since the first start preparation period T1 is started again until the output voltage Vdc of the DC power supply circuit 1 rises to at least a predetermined voltage at the time of restart, the output voltage Vdc of the DC power supply circuit 1 becomes high. Therefore, it is possible to prevent stress from being applied to the components constituting the circuit.

(Embodiment 3)
Hereinafter, Embodiment 3 of the electrodeless discharge lamp lighting device according to the present invention will be described with reference to the drawings. However, since the basic configuration of the present embodiment is the same as that of the second embodiment, common portions are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 6, this embodiment is characterized in that a control signal is given only from the protection circuit 9 to the start timing control circuit 50. The protection circuit 9 may have the same configuration as that of the second embodiment, or may have another configuration as long as it performs the same function as that of the protection circuit 9 of the second embodiment.

  Hereinafter, the operation of the present embodiment will be described with reference to FIG. First, when voltage supply from the commercial power supply AC to the DC power supply circuit 1 is started, the electrodeless discharge is performed through the first start preparation period T1, the second start preparation period T2, and the start period T3 as in the first embodiment. Control for starting the electric lamp 4 is performed. In addition, when a certain period of time has elapsed without the electrodeless discharge lamp 4 being lit during the starting period T3, the protection circuit 9 operates as in the second embodiment. Here, in this embodiment, since the control signal from the protection circuit 9 is given only to the start timing control circuit 50, the operations of the DC power supply circuit 1 and the high frequency power supply circuit 2 are not stopped, and the protection period starts from the start period T3. The process proceeds to the first start preparation period T1 without passing through T5. Then, the above-described series of operations is repeated as in the second embodiment, and when it is repeated three times, it is determined that there is no load by the function of the stop circuit 90, and the operations of the DC power supply circuit 1 and the high-frequency power supply circuit 2 are completely stopped. Circuit is protected.

  As described above, since the start period T3 is shifted to the first start preparation period T1 without passing through the protection period T5, the high frequency power supply circuit 2 does not operate intermittently as in the second embodiment, and is intermittent. Noise caused by a normal operation can be reduced.

  By the way, the start of the electrodeless discharge lamp 4 needs to consider the bulb 40 and the induction coil 3 as a whole unlike the general electrode discharge lamp, and there are the following two modes of discharge. As a discharge sequence, when a high frequency voltage is applied to the induction coil 3, the gas in the bulb 40 is excited through the induction coil 3 and the lamp tube wall of the electrodeless discharge lamp 4, and a high frequency electric field discharge (hereinafter “ E discharge) is generated, and a discharge seed is created, resulting in a glow discharge state. Thereafter, when a higher high-frequency voltage is further applied to the induction coil 3, high-frequency electromagnetic field discharge (hereinafter referred to as “H discharge”) is generated, and the electrodeless discharge lamp 4 is turned on to be in a stable arc discharge state.

  First, the E discharge will be described. The E discharge is a discharge current that flows through the capacitance of the lamp tube wall of the electrodeless discharge lamp 4. When a high frequency voltage is applied to the induction coil 3, the induction coil 3 and the electrodeless discharge lamp are discharged. The gas in the bulb 40 is excited through the capacitance of the lamp tube wall 4 to emit light. This discharge becomes a slight discharge (glow discharge state), and shifts to the main discharge when the high-frequency voltage applied to the induction coil 3 is increased.

  Next, the H discharge will be described. The H discharge is to cause an induction current to flow by electromagnetic induction of the induction coil 3, and the induction coil 3 is a primary winding of a plurality of turns, and the plasma ring generated in the bulb 40 is a secondary winding of one turn. Can be understood as a transformer. Here, the H discharge is a main discharge (arc discharge state) that contributes to the light emission of the electrodeless discharge lamp 4.

  In each of the above-described embodiments, E discharge is generated by applying a high-frequency voltage having such a magnitude that E discharge occurs in the induction coil 3 and no H discharge occurs in the second start preparation period T2, and the start period T3 In FIG. 2, an H discharge is generated by applying a high-frequency voltage large enough to generate an H discharge in the induction coil 3, and the electrodeless discharge lamp 4 is turned on. For this reason, in the second start preparation period T2, E discharge can be generated even if there is some variation depending on surrounding conditions such as dark places and low temperatures. In addition, since the process proceeds to the start period T3 after the E discharge is generated, the H discharge can be generated immediately and the start period T3 in which the high voltage is applied to the induction coil 3 can be shortened. Thus, the startability of the electrodeless discharge lamp 4 can be improved as compared with the case where the electrodeless discharge lamp 4 is started without providing a start preparation period, and the stress on the parts constituting the circuit is reduced. be able to.

  In addition, each said embodiment is mounted and used for the fixture main body of lighting fixtures, such as a street light and a crime prevention light, with the electrodeless discharge lamp 4. FIG. For example, as shown in FIG. 9A, a crime prevention light in which an instrument main body 100 in which an electrodeless discharge lamp 4 is housed is attached to a support pole 101 such as a utility pole provided on a road, or a security light shown in FIG. 9B. As shown in the figure, the lamp-shaped appliance main body 200, the prism 201 constituting the reflecting portion, the lamp socket portion 202 provided at the base portion of the prism 201, the crime prevention light comprising the circuit storage portion 203 provided below the lamp socket portion 202, etc. Used.

  Further, as shown in FIGS. 10A to 10C, any one of the above-described tunnel lamps including a flat box-shaped instrument main body 300 and a reflection plate 301 that reflects light from the electrodeless discharge lamp 4 is provided. The electrodeless discharge lamp lighting device A of the embodiment may be mounted. In addition, the electrodeless discharge lamp 4 has an advantage that it has a long life and requires less frequent maintenance, and has a great advantage of being adopted for a tunnel lamp that is troublesome to maintain. Moreover, in order to improve the safety in the tunnel, it is desired that the tunnel light be restored and re-lighted as soon as possible after a power failure. Here, if the electrodeless discharge lamp lighting device of each of the above embodiments is employed, it is possible to prevent a spark at the time of re-lighting after a power failure, and thus it is possible to provide a more reliable tunnel lamp.

  Of course, the lighting fixture on which each of the above embodiments is mounted is not limited to the above-described one, and at least a fixture main body (not shown) that holds the electrodeless discharge lamp 4 and the electrodeless discharge lamp 4 are disposed in proximity to each other. The lighting fixture provided with the induction coil 3 to be used may be used. In addition, since each of the above embodiments can reduce the stress on the circuit components during the start-up preparation period, for example, a lighting system that turns on when a person approaches the sensor and turns off when the person leaves the sensor, etc. / It can also be suitably used for lighting devices that are frequently turned off.

It is a circuit diagram which shows Embodiment 1 of the electrodeless discharge lamp lighting device which concerns on this invention. It is operation | movement explanatory drawing which shows the frequency characteristic of a high frequency voltage same as the above. It is a time chart which shows operation | movement same as the above. It is a circuit diagram which shows Embodiment 2 of the electrodeless discharge lamp lighting device which concerns on this invention. It is a time chart which shows operation | movement same as the above. It is a circuit diagram which shows Embodiment 3 of the electrodeless discharge lamp lighting device which concerns on this invention. It is a time chart which shows operation | movement same as the above. It is explanatory drawing of the site | part relevant to the electrodeless discharge lamp lighting device of this invention, (a) is sectional drawing of an electrodeless discharge lamp, (b) is a perspective view of a coupler. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the lighting fixture using the electrodeless discharge lamp lighting device of this invention, (a) is a side view of a crime prevention light, (b) is the partially broken front view of the crime prevention light different from (a). . It is a figure which shows a tunnel light same as the above, (a) is a front view, (b) is a side view, (c) is a side view seen from the direction different from (b). It is a figure which shows the conventional electrodeless discharge lamp lighting device, and is a time chart which shows the operation | movement at the time of applying a low high frequency voltage in a starting preparation period. It is a time chart which shows operation | movement at the time of applying a high frequency voltage in the starting preparation period same as the above. It is a time chart which shows operation | movement at the time of providing a starting preparation period after starting a device same as the above and having passed a fixed period.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 DC power supply circuit 2 High frequency power supply circuit 20 Drive circuit 21 Resonance circuit 3 Inductive coil 4 Electrode discharge lamp 5 Starting circuit Q2, Q3 Switching element

Claims (5)

A DC power supply circuit that converts an AC voltage from an AC power supply into a DC voltage and outputs the DC voltage, and one or more switching elements that are switched at a high frequency and a resonance circuit, and converts the output voltage of the DC power supply circuit to a high frequency voltage. A high frequency power supply circuit for supplying to an induction coil arranged close to the electrodeless discharge lamp, a drive circuit for outputting a drive signal for switching the switching element, and an induction coil by controlling the drive circuit to change the frequency of the drive signal A start circuit for starting the electrodeless discharge lamp by gradually increasing the voltage applied to the starter, the starter circuit applying a high-frequency voltage of a magnitude that does not start the electrodeless discharge lamp to the induction coil, and an electrodeless The electrodeless discharge lamp is started after a start period in which a high-frequency voltage large enough to start the discharge lamp is applied to the induction coil, and the start preparation period is small. Is also composed of a first start preparation period and a second start preparation period provided after the first start preparation period. At least the output voltage of the DC power supply circuit reaches a predetermined value during the first start preparation period. In this period, the high frequency power supply circuit applies a high frequency voltage of a magnitude that gives a load to the DC power supply circuit so that the output voltage of the DC power supply circuit does not exceed a predetermined value, and in the second start preparation period, The high-frequency power supply circuit applies a high-frequency voltage that is larger than the high-frequency voltage in the first start-up preparation period and as large as possible within a range in which the electrodeless discharge lamp does not start ,
The protection circuit includes a protection circuit that detects an abnormality in power supply from the high-frequency power supply circuit to the induction coil, and that repeats at least a first start preparation period, a second start preparation period, and a start period in order in the event of an abnormality. The electrodeless discharge lamp lighting device is characterized in that the first start preparation period is restarted until the output voltage of the DC power supply circuit, which has decreased after the abnormality is detected, rises to at least a predetermined value . The start circuit controls the drive circuit to apply a high frequency field discharge voltage for generating a high frequency field discharge in the second start preparation period to the induction coil until the high frequency field discharge is generated, and the high frequency field discharge is generated in the start period. 2. The electrodeless discharge lamp lighting device according to claim 1 , wherein the driving circuit is controlled to apply a high-frequency electromagnetic field discharge voltage for generating an electromagnetic field discharge to the induction coil . The start circuit controls the drive circuit so as to gradually increase the voltage applied to the induction coil at the time of transition from the first start preparation period to the second start preparation period. The electrodeless discharge lamp lighting device according to 1. 4. The drive circuit according to claim 1, wherein the start circuit controls the drive circuit so as to gradually increase the voltage applied to the induction coil when the second start preparation period shifts to the start period. The electrodeless discharge lamp lighting device according to the item. The electrodeless discharge lamp according to any one of claims 1 to 4, wherein at least an appliance main body for holding the electrodeless discharge lamp, an induction coil disposed close to the electrodeless discharge lamp, and high-frequency power is supplied to the induction coil. A lighting apparatus comprising a lighting device.

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