JP2002252094A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device wherein a rated electric power of the discharge lamp connected between output ends can be surely discriminated among plural kinds of discharge lamps with different rated electric powers. SOLUTION: A direct current voltage of a direct-current electric power source 1 is converted into an alternating voltage by an inverter circuit 2. A series circuit of a resonant inductor L1 and a resonant capacitor C1 is connected between the output ends of the inverter circuit 2, and a discharge lamp La is connected in parallel with the resonant capacitor C1. The rated electric power of the discharge lamp La is discriminated from a lamp voltage V1a by a lamp rating detecting part 4, and according to the discriminated result, an output voltage of the direct-current electric power source 1 is made to be changed by an electric power source voltage variable circuit 5, and an output of the inverter circuit 2 is corrected so that the discharge lamp La can be actuated by a rated output. Here, an actuating frequency of the inverter circuit 2 is controlled by an inverter control circuit 3, and the actuating frequency of the inverter circuit 2 is set up at a different frequency from a no-load resonant frequency at a time of detecting the lamp rating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a discharge lamp lighting device of this kind, even when a discharge lamp having a different rated power is mounted, the power supplied to the discharge lamp is automatically corrected so as to become a rated output, and the light output is adjusted. Has been conventionally provided for controlling the pressure to be substantially constant (see, for example, JP-A-6-140168).

FIG. 25 shows a circuit diagram of a conventional discharge lamp lighting device. The discharge lamp lighting device includes a DC power supply 1 having a variable output voltage, an inverter circuit 2 for converting a DC voltage of the DC power supply 1 into an AC voltage and supplying the AC voltage to the discharge lamp La, and an inverter for controlling an output of the inverter circuit 2. A control circuit 3, a lamp rating detector 4 for detecting the rated power of the currently connected discharge lamp La from the lamp voltage Vla, and an output of the inverter circuit 2 based on the detection result of the lamp rating detector 4, DC power supply 1 so that the rated output of La
And a power supply voltage variable circuit 5 for changing the output voltage of the power supply. In this discharge lamp lighting device, the lamp rating detector 4 performs a detection operation at the time of rated output, and the power supply voltage variable circuit 5 changes the output voltage of the DC power supply 1 based on the detection result, and is currently connected. The output of the inverter circuit 2 is corrected according to the rated power of the discharge lamp La.

The inverter circuit 2 includes switching elements Q1 and Q
2 are connected in series, and a resonance inductor L1 and a resonance capacitor C1 are connected between both ends of a low-side switching element Q2 via a DC cut capacitor C2.
Are connected in series. A discharge lamp La such as a fluorescent lamp is connected in parallel with the resonance capacitor C1.

The lamp rating detector 4 comprises a lamp voltage detecting circuit 4a for detecting the lamp voltage of the discharge lamp La, and a comparator CP1 for comparing the output Vcf of the lamp voltage detecting circuit 4a with the reference voltage E1. You. The lamp voltage detection circuit 4a includes a series circuit of resistors R1 and R2 connected between both ends of the discharge lamp La, and a capacitor Cf connected between both ends of the resistor R2 via a diode Df, and detects the lamp voltage Vla. The voltage is divided by the voltage dividing circuit of the resistors R1 and R2, rectified by the diode Df, and smoothed by the capacitor Cf, so that the voltage Vcf is proportional to the lamp voltage Vla.
Occurs. Then, the rated power of the discharge lamp La is determined by comparing the level of the voltage Vcf with the reference voltage E1 by the comparator CP1.

Then, the power supply voltage variable circuit 5 changes the output of the inverter circuit 2 based on the detection result of the lamp rating detection section 4 so that the output of the inverter circuit 2 becomes the rated output of the currently connected discharge lamp La. Since the output voltage is changed, the output of the inverter circuit 2 can be automatically corrected even when the discharge lamps La having different rated powers are connected, and the discharge lamp La can be lit at the rated output.

Here, FIG. 26 shows two types of discharge lamps La.
Of the inverter circuit 2 (hereinafter, referred to as a ballast VI characteristic). Note that the ballast VI characteristic is such that when the current is plotted on the horizontal axis and the voltage is plotted on the vertical axis, the impedance of the discharge lamp La is assumed to be resistance, and when the resistance value is changed from 0 to infinity,
The trajectory of the current Ila flowing through the resistor and the voltage Vla across the resistor are shown.

A and B in FIG. 26 indicate the lamp VI characteristics of discharge lamps LA and LB having different rated current, rated voltage and rated power, respectively, and points a and b indicate the discharge lamps LA and LB, respectively. , Respectively.
Here, the lamp voltage Va corresponding to the rated operating point a of one discharge lamp LA is lower than the lamp voltage Vb corresponding to the rated operating point b of the other discharge lamp LB. In this example, a voltage corresponding to a voltage V1 higher than the lamp voltage Va and lower than the lamp voltage Vb is set as the reference voltage E1.

In FIG. 26, W1 and W2 indicate ballast VI characteristics of the inverter circuit 2. If the ballast VI characteristic of the inverter circuit 2 is set to W1, the discharge lamp LA is turned on at the rated output. If the ballast VI characteristic is set to W2, the discharge lamp LB can be lit at the rated output.

Here, the ballast V-
When the discharge lamp LA is connected when the I-characteristics are as shown by the solid line W1 in FIG. 26, the detection voltage Vcf of the lamp voltage detection circuit 4a at the rated output is lower than the reference voltage E1. And the output of the comparator CP1 becomes H level. At this time, in the power supply voltage variable circuit 5,
Judging that the discharge lamp LA is connected, the output voltage of the DC power supply 1 is not changed, and the ballast VI characteristic of the inverter circuit 2 is kept at W1. On the other hand, when the discharge lamps LB having different rated powers are connected, the detection voltage Vcf of the lamp voltage detection circuit 4a at the time of the rated output becomes higher than the reference voltage E1, and the output of the comparator CP1 becomes L.
Level. At this time, the power supply voltage variable circuit 5 determines that the discharge lamp LB is connected, and outputs the output voltage Vdc of the DC power supply 1 until the ballast VI characteristic becomes a characteristic indicated by a broken line W2 in FIG. So that
The discharge lamp LB can be turned on near the rated power.

In the discharge lamp lighting device described above, the lamp voltage Vla at the time of rated output is detected, and this lamp voltage Vla is detected.
Although the rated power of the discharge lamp La is determined from the la, for example, the lamp current Ila is detected using a current transformer, and the lamp current Ila at the time of the rated output is compared with a predetermined reference value. A device for determining the rated power has been conventionally provided.

[0012]

In the discharge lamp lighting device having the above structure, the lamp voltage or lamp current at the time of rated output is detected, and the rated power of the discharge lamp La is determined from the detection result. When the difference between the lamp voltage and the lamp current at the time of the rated output is small among a plurality of types of discharge lamps La different from each other, there is a problem that it is difficult to determine the rated power.

FIG. 27 shows lamp VI characteristics A and B of two types of discharge lamps LA and LB having substantially equal rated voltages and different rated powers. FIG. 28 shows two lamps having substantially equal rated currents and different rated powers. Types of discharge lamps LB, LC lamp V-
I characteristics B and C are shown. Further, FIG. 29 shows the lamp VI characteristics A of the three types of discharge lamps LA, LB and LC described above.
B and C are shown.

Here, as shown in FIG. 27, since the two types of discharge lamps LA and LB have substantially the same lamp voltage Vla at the rated output, the rated power is calculated from the difference between the lamp voltages Vla at the rated output. When it is determined, there is a possibility that the rated power is erroneously determined. Also, as shown in FIG.
Since the types of discharge lamps LB and LC have substantially the same lamp current Ila at the rated output, when the rated power is determined from the difference between the lamp currents Ila at the rated output, the rated power may be erroneously determined. Was. Further, when the currently connected discharge lamp is determined from the above three types of discharge lamps LA, LB, LC, the lamp voltage Vla at the rated output is substantially equal between the two types of discharge lamps LA, LB. Since the lamp current Ila at the rated output is substantially equal between the other two types of discharge lamps LB and LC, all the discharge lamps are determined from the detection result of only the lamp voltage Vla or only the lamp current Ila. I couldn't. Therefore, it is necessary to detect both the lamp voltage Vla and the lamp current Ila to determine the discharge lamp in a stepwise manner, which complicates the circuit configuration of the lamp rating detection unit 4 and raises the cost. Was.

Further, even if the lamp voltage at the rated output is slightly different between a plurality of types of discharge lamps having different rated powers, the lamp voltage Vla varies depending on the ambient temperature as shown in FIG. However, the rated power of the discharge lamp may not be accurately determined depending on the ambient temperature because the temperature is high near normal temperature and low in a low or high temperature region.
30A and 30B show the temperature characteristics of the lamp voltage Vla of the two types of discharge lamps LA and LB, respectively.
At around room temperature, the lamp voltage Vla of the discharge lamp LA is
1 and the lamp voltage Vla of the discharge lamp LB is
Since it is lower than 1, the discharge lamp can be determined by comparing the level of the lamp voltage Vla at the time of rated output with the level of the voltage V1. Since the voltage is lower than the voltage V1, the discharge lamp LA is
Therefore, it is necessary to specify the ambient temperature when detecting the lamp rating. In addition, since the lamp current Ila also varies according to the ambient temperature, the rated power of the discharge lamp cannot be accurately determined unless the ambient temperature at the time of detecting the lamp rating is also specified.

Also, it is conceivable that the lamp voltage and the lamp current may fluctuate due to variations in the characteristics of the discharge lamp and variations in the characteristic values of various components. The rated power of the discharge lamp can be determined only when the difference between the lamp voltages or the difference between the lamp currents is sufficiently large compared to the amount of change in the lamp voltage or the lamp current caused by variations in the characteristics of the discharge lamp. Did not.

The present invention has been made in view of the above problems, and an object thereof is to reduce the rated power of a discharge lamp connected between output terminals from a plurality of types of discharge lamps having different rated powers. An object of the present invention is to provide a discharge lamp lighting device that can be reliably determined.

[0018]

In order to achieve the above object, according to the first aspect of the present invention, a DC power supply unit whose output voltage is variable, and a DC voltage of the DC power supply unit is switched by a switching element to thereby obtain an AC voltage. An inverter circuit, a control circuit for controlling on / off of a switching element, a series circuit of a resonance capacitor and a resonance inductor connected between output terminals of the inverter circuit, and a parallel connection to the resonance capacitor. A load circuit section including at least one connected discharge lamp, and lamp rating detection for detecting a rated power of the discharge lamp included in the load circuit section by detecting at least one of a lamp voltage and a lamp current. By changing the output voltage of the DC power supply unit according to the detection result of the lamp rating detection unit,
In a discharge lamp lighting device for lighting a plurality of types of discharge lamps having different rated powers, the control circuit sets an operating frequency of the inverter circuit to a no-load resonance frequency at a rated output and an inverter circuit at a lamp rated detection. The operating frequency of the inverter circuit section is set to a frequency different from the no-load resonance frequency. Is set to a frequency different from the no-load resonance frequency, between a plurality of discharge lamps having substantially the same rated voltage and different rated powers, or a plurality of discharge lamps having substantially the same rated current and different rated powers. The difference between the lamp voltage and the lamp current can be increased, and the rated power can be easily determined.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a DC power supply having a variable output voltage, and an inverter circuit for switching a DC voltage of the DC power supply by a switching element to convert the DC voltage into an AC voltage. A control circuit for controlling on / off of a switching element, a series circuit of a first resonance capacitor and a first resonance inductor connected between output terminals of the inverter circuit, and a first resonance capacitor A series circuit of a second resonance capacitor and a second resonance inductor connected between both ends of the first circuit, a load circuit section including at least one discharge lamp connected in parallel to the second resonance capacitor, and a lamp A lamp rating detector for detecting the rated power of the discharge lamp included in the load circuit by detecting at least one of the voltage and the lamp current In a discharge lamp lighting device for lighting a plurality of types of discharge lamps having different rated powers by changing an output voltage of a DC power supply according to a detection result of a lamp rating detection unit, the control circuit unit starts the lamp. At the same time, the operating frequency of the inverter circuit unit is set to a frequency different from the two no-load resonance frequencies, and the operating frequency is set to one of the two no-load resonance frequencies at the time of rated output, and when the lamp rating is detected. The operating frequency is set to be substantially the same as the operating frequency at the time of starting the lamp.The operating frequency of the inverter circuit is set to the no-load resonance frequency at the time of rated output. Since the operating frequency is set to a frequency different from the no-load resonance frequency, the rated voltage is approximately equal and the rated power Between different discharge lamps, or, it can increase the difference in the lamp voltage or the lamp current between the different discharge lamps of almost equal and the rated power rated current, it is possible to easily determine the rated power. In addition, the control circuit sets the operating frequency of the inverter circuit to substantially the same frequency when detecting the lamp rating and when starting the lamp, and sets the no-load resonance frequency when the lamp is turned on. The light output of the discharge lamp does not darken once before the lamp is turned on, and the difference between the light output at the time of starting the lamp and when the lamp is turned on and at the time of the rated detection is reduced so that the user feels uncomfortable. Can be prevented.

According to a third aspect of the present invention, in the first or second aspect of the invention, the output voltage of the DC power supply at the time of detecting the lamp rating and the output voltage of the DC power supply at the time of the rated output are set to substantially the same voltage. In addition to the function of the invention of claim 1 or 2, the output voltage of the DC power supply unit is set to a voltage substantially equal to the output voltage at the rated output when the lamp rating is detected. Can be prevented from lowering, and the difference between the light output at the time of starting and lighting the lamp and at the time of rating detection can be reduced to prevent the user from feeling uncomfortable.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the output voltage of the DC power supply unit at the time of detecting the lamp rating is a minimum voltage value at which the discharge lamp can maintain the lighting state. In addition to the operation of the invention of claim 1 or 2, the output voltage of the DC power supply unit is set to the minimum voltage value at which the discharge lamp can maintain the lighting state when the lamp rating is detected. The difference between the lamp voltage and the lamp current between the lamps increases, and the rated power can be easily determined.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the load circuit is configured by connecting a plurality of discharge lamps of the same type in series or in parallel. In addition to the effects of the fourth to fourth aspects, since a plurality of discharge lamps are connected in series or in parallel, a difference in lamp voltage or lamp current between a plurality of discharge lamps having different rated powers increases, and Can be easily determined.

According to a sixth aspect of the present invention, in the first to fifth aspects, the inverter circuit section has a series circuit of first and second switching elements connected between output terminals of the DC power supply section. The control circuit unit sets the on-duty of the first and second switching elements to approximately 50% at the time of detecting the lamp rating and at the time of rated output, and sets the on-duty of the first and second switching elements at the time of starting the lamp. The on-duty is set to a value different from the on-duty at the time of detecting the lamp rating. Is set to approximately 50%, but when the lamp is started, the on-duty is set to a value different from that when the lamp rating is detected. Can increase the output of the inverter circuit unit than that in the lamp starting at the time of detection and during lamp operation,
Therefore, the light output of the discharge lamp does not temporarily decrease between the time the lamp is started and the time the lamp is turned on. Can be prevented from being felt.

In the invention of claim 7, according to claims 1, 2, 3,
In the invention of 5 or 6, the output voltage of the DC power supply unit at the time of starting the lamp is set to a voltage lower than the output voltage at the time of rated output, and the output voltage of the DC power supply unit at the time of lamp rating detection is set to the output at the rated output. The voltage is set to substantially the same voltage as the voltage,
In addition to the effects of the invention of 3, 5, or 6, when the lamp is started, the output voltage of the DC power supply unit is set to a voltage lower than the rated output,
At the time of lamp rating detection, the voltage is set to approximately the same as at the time of rated output, so that when detecting the rated power of the discharge lamp after starting, it is possible to suppress a decrease in the light output of the discharge lamp. The difference in light output from that at the time of rating detection can be reduced, and the user can be prevented from feeling uncomfortable.

According to an eighth aspect of the present invention, in any of the first to seventh aspects, the level of at least one of the lamp voltage or the lamp current and a predetermined threshold value determined by the rated power of the discharge lamp is increased. By comparing
A lamp abnormality detector for detecting an abnormal state of the discharge lamp;
A threshold setting unit configured to set the threshold to a value corresponding to the rated power of the discharge lamp included in the load circuit unit based on a detection result of the lamp rating detection unit, In addition to the effects of the first to seventh aspects, the lamp abnormality detecting unit detects an abnormal state of the discharge lamp by comparing at least one of the lamp voltage and the lamp current with a threshold. In the threshold setting section, the threshold value is changed according to the detection result of the lamp rating detection section. Therefore, the threshold value can be automatically set according to the rated power of the connected discharge lamp. Thus, abnormality of the discharge lamp can be reliably detected.

According to a ninth aspect of the present invention, in the first to eighth aspects of the present invention, the power supply voltage varying section for changing the output voltage of the DC power supply section and the lamp rating detecting section are constituted by a one-chip microcomputer. In addition to the functions of the first to eighth aspects of the present invention, it is not necessary to largely change the circuit configuration when changing or increasing the types of discharge lamps that can be distinguished, and the mounting area of circuit components is also reduced. Can be smaller.

According to a tenth aspect of the present invention, in the first to ninth aspects of the present invention, the discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 24 W or a high-frequency dedicated fluorescent lamp with a rated power of 32 W. 10. The compact fluorescent lamp according to claim 1, wherein the lamp rating detection unit performs a detection operation in a temperature range where the ambient temperature of the discharge lamp is approximately 0 ° C. or more and approximately 50 ° C. or less. The same operation as that of the invention is achieved.

According to an eleventh aspect of the present invention, in the first to ninth aspects of the present invention, the discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 32 W or a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 42 W. Wherein the lamp rating detection unit performs a detection operation in a temperature range where the ambient temperature of the discharge lamp is approximately (−10) ° C. or more and approximately 50 ° C. or less. The same effects as those of the inventions 1 to 9 can be obtained.

According to a twelfth aspect of the present invention, in the first to ninth aspects of the present invention, the discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 24 W, and a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 32 W. A high-frequency lighting-only compact fluorescent lamp having a rated power of 42 W, comprising at least one discharge lamp. The detection operation is performed in a temperature range of about 50 ° C. or lower, and the same effects as those of the first to ninth aspects are achieved.

[0030]

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

(Embodiment 1) FIG. 1 is a circuit block diagram of a discharge lamp lighting device according to this embodiment, and FIG. 2 is a specific circuit diagram thereof. The discharge lamp lighting device includes a DC power supply 1 having a variable output voltage, and an inverter circuit 2 for converting a DC voltage of the DC power supply 1 into an AC voltage and supplying the AC voltage to a load circuit unit including a discharge lamp La such as a fluorescent lamp. An inverter control circuit 3 for controlling the output of the inverter circuit 2, a lamp rating detection unit 4 for detecting the rated power of the discharge lamp La included in the load circuit unit by detecting the lamp voltage, and a lamp rating detection unit 4. Inverter circuit 2
And a power supply voltage variable circuit 5 for changing the output voltage of the DC power supply 1 so that the output of the DC power supply 1 becomes the rated output of the discharge lamp La. In this discharge lamp lighting device, after the inverter control circuit 3 controls the output of the inverter circuit 2 to preheat and start the discharge lamp La, the lamp rating detector 4 detects the rated power of the discharge lamp La. Then, the power supply voltage variable circuit 5 changes the output voltage of the DC power supply 1 based on the detection result of the lamp rating detection unit 4, corrects the output of the inverter circuit 2 in accordance with the rated power of the discharge lamp La, and Is lit.

The inverter circuit 2 includes switching elements Q1 and Q
2 are connected in series, and the switching elements Q1,
One end of a resonance inductor L1 is connected to a connection point of Q2 via a DC cut capacitor C2, and a resonance capacitor C1 is connected between the other end of the resonance inductor L1 and a negative electrode of the DC power supply 1. . The discharge lamp La is connected in parallel with the resonance capacitor C1. The inverter control circuit 3 is constituted by, for example, a one-chip PWM control IC, and alternately turns on / off the switching elements Q1 and Q2 at a high frequency.
2 can be changed.

The lamp rating detecting section 4 includes a lamp voltage detecting circuit 4a for detecting a lamp voltage Vla of the discharge lamp La,
The detection voltage Vcf of the lamp voltage detection circuit 4a and the reference voltage E1
And a comparator CP1 that compares the levels of the two. The lamp voltage detecting circuit 4a includes a series circuit of resistors R1 and R2 connected between both ends of the discharge lamp La;
A diode D2 whose cathode is connected to the connection point of the DC power supply 1 and the anode of the DC power supply 1;
A diode D1 having an anode connected to a connection point of the resistors R1 and R2, a capacitor Cf connected between a cathode of the diode D1 and a negative electrode of the DC power supply 1, and a resistor R3 connected in parallel to the capacitor Cf. The voltage Vla of the discharge lamp La is divided by the resistors R1 and R2, rectified by the diode D1, and then smoothed by the capacitor Cf to generate a voltage Vcf proportional to the lamp voltage Vla. Then, the level of the detected voltage Vcf and the reference voltage E1 are compared by the comparator CP1 to determine the rated power of the discharge lamp La.

The output of the lamp rating detector 4 is a switch SW.
The output of the inverter circuit 2 is output to the rated output of the currently mounted discharge lamp La based on the detection result of the lamp rating detection unit 4. Thus, the output voltage of the DC power supply 1 is changed. Note that the switch SW is turned on /
The turning off is controlled by the inverter control circuit 3. In the inverter control circuit 3, the operating frequency of the inverter circuit 2 at the time of detecting the lamp rating is set to a frequency different from the operating frequency at the time of preheating, starting, or at the time of rated output. Since the switch SW is turned on only during the period in which the operation is performed, the output voltage of the DC power supply 1 does not change during periods other than when the lamp rating is detected.

Next, the operation of the discharge lamp lighting device will be described with reference to FIGS. W1 in FIG. 3 indicates the initial ballast VI characteristic of the inverter circuit 2. At this time, the inverter control circuit 3 sets the operating frequency of the inverter circuit 2 to substantially the same as the no-load resonance frequency of the resonance circuit including the resonance inductor L1 and the resonance capacitor C1, so that the current value is constant. , The ballast VI characteristics such that the voltage value changes. A and B in FIG. 3 indicate the lamp VI characteristics of two types of discharge lamps LA and LB having substantially the same rated voltage and different rated power, respectively, and points a and b indicate the discharge lamps LA and LB, respectively. The rated operating point of LB is shown. Since the rated operating point a of the discharge lamp LA coincides with the intersection of the lamp VI characteristic (A) and the ballast VI characteristic (W1) of the discharge lamp LA, the inverter circuit 2 indicates W1. If the discharge lamp LA operates at the ballast VI characteristics, the discharge lamp LA operates at the rated output. Here, the lamp voltage Vla at the point where the lamp VI characteristic and the ballast VI characteristic of the discharge lamp LA intersect, and the lamp voltage Vla at the point where the lamp VI characteristic and the ballast VI characteristic of the discharge lamp LB intersect. Since the lamp voltage Vla is set to substantially the same voltage, it is difficult to determine the rated power of the discharge lamp from the lamp voltage Vla at the time of rated output.

Therefore, in the discharge lamp lighting device of the present embodiment, the inverter control circuit 3 sets the operating frequency of the inverter circuit 2 at the time of detecting the lamp rating to a frequency different from the no-load resonance frequency. The ballast VI characteristic is changed to the characteristic indicated by W2 in FIG. 4 to perform the operation of determining the rated power.

In this case, the points a 'and b' where the lamp VI characteristics (A and B in FIG. 4) and the ballast VI characteristics (W2 in FIG. 4) of the discharge lamps LA and LB intersect, respectively. Is the operating point of the discharge lamps LA and LB when the lamp rating is detected, and the difference between the lamp voltage Vla at the operating point a 'and the lamp voltage Vla at the operating point b' becomes large. Can be easily performed. That is, the lamp rating detection unit 4 uses a voltage corresponding to a voltage V1 lower than the lamp voltage Vla of the discharge lamp LA at the operating point a 'and higher than the lamp voltage Vla of the discharge lamp LB at the operating point b' as a reference. The rated power of the discharge lamp La is determined by comparing the reference voltage E1 with the output Vcf of the lamp voltage detection circuit 4a.

Here, the operation of each part from the start of the lamp to the rated output will be briefly described. Inverter control circuit 3
Controls the operating frequency of the inverter circuit 2. After the discharge lamp La is preheated and started, the switch SW is turned on while the operating frequency of the inverter circuit 2 is changed to a frequency higher than the no-load resonance frequency. , The detection operation is performed by the lamp rating detection unit 4. When the operating frequency at the time of starting the lamp is higher than the no-load resonance frequency, the difference between the operating frequency of the inverter circuit 2 and the no-load resonance frequency is increased. Is changed to a higher frequency, the switch SW is turned on, and the detection operation is performed by the lamp rating detection unit 4.

At this time, in the lamp rating detecting section 4, the comparator CP1 detects the detection result Vcf of the lamp voltage detecting circuit 4a.
And the reference voltage E1 are compared to determine the rated power of the discharge lamp La. Lamp voltage detection circuit 4a
Is higher than the reference voltage E1, the output of the comparator CP1 goes low, and if the detection result Vcf of the lamp voltage detection circuit 4a is lower than the reference voltage E1, the output of the comparator CP1 goes high. become.

If the output of the lamp rating detector 4 is at the L level, the power supply voltage variable circuit 5 determines that the discharge lamp LA is mounted, and the output voltage Vdc of the DC power supply 1 is not changed. The operating frequency of the inverter circuit 2 is returned to the no-load resonance frequency. On the other hand, if the output of the lamp rating detector 4 is at the H level, the power supply voltage
B, the operating frequency of the inverter circuit 2 is returned to the no-load resonance frequency, and then, as shown in FIG. Lower. At this time, the ballast VI characteristic of the inverter circuit 2 is as shown by W3 in FIG. When the operation of detecting the lamp rating is completed, the inverter control circuit 3 turns off the switch SW.

As described above, in the inverter control circuit 3,
When the lamp rating is detected, the operating frequency of the inverter circuit 2 is changed to a frequency higher than the no-load resonance frequency. By operating the inverter circuit 2 at an operation frequency higher than the no-load resonance frequency, the rated voltages are substantially equal and Since the difference in lamp voltage is increased between a plurality of types of discharge lamps having different rated powers, it is possible to easily determine the discharge lamp.

In this embodiment, the operating frequency of the inverter circuit 2 is changed to a frequency higher than the no-load resonance frequency when the lamp rating is detected. It is needless to say that the operating frequency of No. 2 may be changed to a frequency lower than the no-load resonance frequency.

(Embodiment 2) FIG. 6 is a circuit diagram of a discharge lamp lighting device according to this embodiment. In the discharge lamp lighting device of the first embodiment, the lamp voltage detection circuit 4 for detecting the lamp voltage Vla
a, the lamp rating detection unit 4 determines the rated power of the discharge lamp La from the detection result of the lamp voltage detection circuit 4a, whereas in the present embodiment, the lamp current I
A lamp current detection circuit 4b for detecting la is provided, and the lamp rating detection unit 4 determines the rated power of the discharge lamp La from the detection result of the lamp current detection circuit 4b. Note that the configuration other than the lamp rating detection unit 4 is the same as that of the first embodiment.
The same components are denoted by the same reference numerals, and description thereof will be omitted.

In the present embodiment, the current transformer CT is provided in the path through which the lamp current Ila flows. R1,
A diode D2 having a cathode connected to a connection point of R2 and an anode connected to a negative electrode of the DC power supply 1;
A lamp current detection circuit includes a diode D1 having an anode connected to a connection point between the resistors R1 and R2, a capacitor Cf connected between both ends of the resistor R2 via the diode D1, and a resistor R3 connected in parallel to the capacitor Cf. The lamp current detection circuit 4b converts the lamp current Ila detected using the current transformer CT into a voltage value and outputs the voltage value. Then, in the lamp rating detection section 4, the comparator CP1 compares the output Vcf of the lamp current detection circuit 4b with the reference voltage E1 to determine the rated power of the discharge lamp La.

Next, the operation of the discharge lamp lighting device will be described with reference to FIG. W1 in FIG. 7 indicates the initial ballast VI characteristic of the inverter circuit 2. At this time, the inverter control circuit 3 sets the operating frequency of the inverter circuit 2 to
The frequency is set to be substantially the same as the no-load resonance frequency of the resonance circuit including the resonance inductor L1 and the resonance capacitor C1, and has a ballast VI characteristic in which the current value is constant and the voltage value changes. . Also, A, B in FIG.
Indicates lamp VI characteristics of two types of discharge lamps LA and LB having substantially equal rated currents and different rated powers. Here, the lamp V of one discharge lamp LA
The lamp current at point a where the -I characteristic (A) and the ballast VI characteristic (W1) intersect, the lamp VI characteristic (B) and the ballast VI characteristic (W1) of the other discharge lamp LB. Is substantially the same as the lamp current at the point b at which the intersection occurs, it is difficult to determine the rated power of the discharge lamp from the lamp current Ila.

Therefore, in the discharge lamp lighting device of the present embodiment, the inverter control circuit 3 sets the operating frequency of the inverter circuit 2 when detecting the lamp rating to a frequency different from the no-load resonance frequency. Is changed to a characteristic as shown by W2 in FIG. In this case, points a 'and b' where the lamp VI characteristics (A and B in FIG. 7) and the ballast VI characteristics (W2 in FIG. 7) of the discharge lamps LA and LB intersect respectively are the lamp ratings. It becomes the operating point of the discharge lamps LA and LB at the time of detection, and the difference between the lamp current Ila of the discharge lamp LA at the operating point a 'and the lamp current Ila of the discharge lamp LB at the operating point b' becomes large. Thus, the rated power of the discharge lamp can be easily determined. That is, the lamp rating detection unit 4 uses a voltage corresponding to a current I1 which is larger than the lamp current Ila of the discharge lamp LA at the operating point a 'and smaller than the lamp current Ila of the discharge lamp LB at the operating point b' as a reference. The reference voltage E1 and the lamp current detection circuit 4
The rated power of the discharge lamp La is determined by comparing the level of the output Vcf with the level b.

Here, the operation of each section from the start of the lamp to the rated output will be briefly described. Inverter control circuit 3
Controls the operating frequency of the inverter circuit 2. After the discharge lamp La is preheated and started, the switch SW is turned on while the operating frequency of the inverter circuit 2 is changed to a frequency higher than the no-load resonance frequency. , The detection operation is performed by the lamp rating detection unit 4. When the operating frequency at the time of starting the lamp is higher than the no-load resonance frequency, the difference between the operating frequency of the inverter circuit 2 and the no-load resonance frequency is increased. Is changed to a higher frequency, the switch SW is turned on, and the detection operation is performed by the lamp rating detection unit 4.

At this time, in the lamp rating detecting section 4, the comparator CP1 detects the detection result Vcf of the lamp current detecting circuit 4b.
And the reference voltage E1 are compared to determine the rated power of the discharge lamp La. When the detection operation of the lamp rating is completed, the output voltage of the DC power supply 1 is changed in the power supply voltage variable circuit 5 according to the detection result of the lamp rating detection unit 4, and the DC voltage is changed so that the discharge lamp performs the rated output operation. The output voltage of the power supply 1 is corrected. Further, the inverter control circuit 3 returns the operating frequency of the inverter circuit 2 to the no-load resonance frequency and turns off the switch SW.

In this embodiment, the operating frequency of the inverter circuit 2 is changed to a frequency higher than the no-load resonance frequency at the time of detecting the lamp rating. It is needless to say that the operating frequency of No. 2 may be changed to a frequency lower than the no-load resonance frequency.

(Embodiment 3) Embodiment 3 of the present invention is shown in FIG.
This will be described with reference to FIGS. In the present embodiment, in the discharge lamp lighting device shown in FIG.
A rectifier circuit DB for rectifying the DC power supply 1 to the AC power supply VS;
A buck-boost chopper circuit 6 for converting a rectified voltage of the rectifier circuit DB into a substantially constant DC voltage, and a power supply voltage variable for controlling an output of the buck-boost chopper circuit 6 based on an output of the dimmer 8 or the lamp rating detection unit 4. And a chopper control circuit 7 as a unit. Since the configuration other than the DC power supply 1 is the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

The step-up / step-down chopper circuit 6 includes a switching element Q3 having one end connected to the high-voltage side terminal of the rectifier circuit DB.
A diode D3 having a cathode connected to the other end of the switching element Q3 and an anode connected to the low-voltage terminal of the rectifier circuit DB, and an inductor L2 and a switching element Q4 connected between both ends of the diode D3. Circuit, inductor L2 and switching element Q4
And a smoothing capacitor C3 connected between the cathode of the diode D4 and the low-voltage side terminal of the rectifier circuit DB.

The switching elements Q3 and Q4 are, for example, MO
SFET, which is turned on / off by the chopper control circuit 7
Off is controlled. The chopper control circuit 7 includes, for example, a one-chip PWM control IC, and includes a switching element Q
3, By changing the on duty of Q4,
A DC voltage Vdc is generated by increasing or decreasing the power supply voltage of the AC power supply VS.

Next, the operation of the discharge lamp lighting device will be briefly described with reference to FIGS. W1, W2 in FIG.
9 shows the ballast VI characteristic of the inverter circuit 2 described above.
The characteristics are as shown in FIG. In addition, A in FIG.
B indicates the lamp VI characteristics of two types of discharge lamps LA and LB having substantially equal rated voltages and different rated powers, respectively, and points a and b indicate discharge lamps LA and L, respectively.
B shows the rated operating point. Since the rated operating point a of the discharge lamp LA coincides with the intersection of the lamp VI characteristic (A) and the ballast VI characteristic (W1) of the discharge lamp LA, the inverter circuit 2 indicates W1. Ballast V-
If the discharge lamp LA operates at the I characteristic, the discharge lamp LA operates at the rated output.

Here, the lamp voltage Vla and the lamp current Ila at the intersection of the lamp VI characteristic (A) and the ballast VI characteristic (W1) of the discharge lamp LA, and the discharge lamp L
B lamp VI characteristics (B) and ballast VI characteristics (W
Lamp voltage Vla and lamp current Ila at the point where 1) intersects
It is very difficult to determine the rated power of the discharge lamp from the difference between the lamp voltage Vla or the lamp current Ila during rated lighting, as in the discharge lamp lighting device described in the conventional example. Also, as in the discharge lamp lighting device described in the first or second embodiment, the operating frequency of the inverter circuit 2 is made different from the no-load resonance frequency, and the ballast VI characteristic changes to the characteristic indicated by W2 in FIG. Even so, the difference in the lamp voltage Vla or the difference in the lamp current Ila between the two discharge lamps LA and LB is small, and it is difficult to determine the rated power of the discharge lamp.

Therefore, in the discharge lamp lighting device of the present embodiment, the operating frequency of the inverter circuit 2 is changed to a frequency different from the no-load resonance frequency when the lamp rating is detected, and the output of the DC power supply 1 is reduced. The output of the inverter circuit 2 is set to the minimum output that allows the discharge lamp La to maintain the lighting state, and the lamp rating detection operation is performed in this state.

In FIG. 10, W4 is the output voltage Vdc of the DC power supply 1.
, The operating frequency of the inverter circuit 2 is increased, and the output of the inverter circuit 2 is
Shows the ballast VI characteristic when the minimum output capable of maintaining the lighting state (that is, the output at the lower limit of dimming) is shown, and near the lower limit of dimming, the inclination of the ballast VI characteristic increases. I have. Therefore, this ballast VI characteristic (W3) and the lamp VI characteristic (A) of the discharge lamp LA
Voltage Vla or lamp current I at point a 'where
Since the difference between la and the lamp voltage Vla or the lamp current Ila at the point b 'where the ballast VI characteristic (W3) and the lamp VI characteristic (B) of the discharge lamp LB intersect increases, the lamp voltage Vla Alternatively, it is possible to easily determine the rated power by detecting the lamp current Ila.

Here, the operation of each section from the start of the lamp to the rated output will be briefly described. In this discharge lamp lighting device, after the discharge lamp La is preheated and started, the chopper control circuit 7 gradually reduces the output voltage Vdc of the DC power supply 1, and at the dimming lower limit, the inverter control circuit 3 The operating frequency is set to a frequency higher than the no-load resonance frequency, and in this state, the switch SW is turned on,
The detection operation is performed by the lamp rating detection unit 4. In addition,
When the operation frequency at the time of starting the lamp is higher than the no-load resonance frequency, the inverter control circuit 3 further increases the operation frequency of the inverter circuit 2 in order to further increase the difference between the operation frequency of the inverter circuit 2 and the no-load resonance frequency. In a state where the frequency is changed to a high frequency, the switch SW is turned on, and the detection operation is performed by the lamp rating detection unit 4.

At this time, the lamp rating detector 4 compares the detection result Vcf of the lamp voltage detection circuit 4a with a reference voltage E1 corresponding to a predetermined threshold voltage V1 by a comparator C.
The rated power of the discharge lamp La is determined by comparison at P1.

That is, when the detection result Vcf of the lamp voltage detection circuit 4a is higher than the reference voltage E1, the output of the comparator CP1 goes to the L level. From this detection result, the chopper control circuit 7 determines that the discharge lamp LA is mounted. Is determined, the output voltage Vdc of the DC power supply 1 is returned to a value before the detection operation is started (that is, a value near the rated output of the discharge lamp LA), and the inverter control circuit 3 sets the operating frequency f of the inverter circuit 2 to f. Is returned to the no-load resonance frequency f0, and the switch SW is turned off.

On the other hand, when the detection result Vcf of the lamp voltage detection circuit 4a is lower than the reference voltage E1, the comparator C
Since the output of P1 goes to the H level, the chopper control circuit 7 determines from this detection result that the discharge lamp LB is mounted, and changes the output voltage Vdc of the DC power supply 1 so that the discharge lamp LB performs the rated output operation. At the same time, the inverter control circuit 3 returns the operating frequency f of the inverter circuit 2 to the no-load resonance frequency f0 to turn off the switch SW.

FIG. 23 shows a compact fluorescent lamp (hereinafter, referred to as 42 W) having a rated power of 42 W dedicated to high frequency lighting.
It is called a W lamp. ), A compact fluorescent lamp dedicated to high frequency lighting with a rated power of 32 W (hereinafter referred to as 32 W lamp), and a compact fluorescent lamp dedicated to high frequency lighting with a rated power of 24 W (hereinafter referred to as 24 W lamp). 3) shows the relationship between the lamp voltage Vla and the ambient temperature at the time of rated output.

Here, when discriminating between the 42W lamp and the 32W lamp, the detection of the lamp voltage Vla at the rated output of each lamp is only required to detect the rated power in the temperature range of (−10) ° C. or more and 45 ° C. or less. No discrimination could be made. In this case, the reference voltage E1 of the comparator CP1
Is set to a voltage corresponding to the voltage V1 in FIG. 23. However, when the ambient temperature reaches 50 ° C., the lamp voltage Vla of the 42W lamp falls below the voltage V1, so that
There is a risk of false detection as a W lamp.

For the 32W lamp and the 24W lamp,
Only in the temperature range of 10 ° C. or more and 35 ° C. or less, the discharge lamp could be determined. In this case, the reference voltage E1 of the comparator CP1 is set to a voltage corresponding to the voltage V2 in FIG. 23. However, since the difference between the lamp voltage of the 24W lamp or the 32W lamp and the voltage V2 is small, variations in lamp characteristics and In addition, a lamp may be erroneously detected due to a change in the lamp voltage Vla due to a variation in component constants.

FIG. 24 shows the relationship between the lamp voltage Vla and the ambient temperature when the 42 W lamp, the 32 W lamp, and the 24 W lamp are lit at the dimming lower limit. In the present embodiment, the rated power of the discharge lamp is detected with the output of the inverter circuit 2 being the minimum output capable of maintaining the lighting state of the discharge lamp. Since the difference between the lamp voltage and the lamp is increased, the temperature range in which the lamp rating can be determined can be expanded.

That is, between the 42W lamp and the 32W lamp, the reference voltage E1 of the comparator CP1 is changed to the level shown in FIG.
It is set to a voltage corresponding to the middle voltage V3,
Both can be discriminated in the temperature range of 50 ° C. or less. Further, between the 32W lamp and the 24W lamp, the reference voltage E1 of the comparator CP1 is changed to the voltage V4 in FIG.
, And both can be determined in a temperature range of 0 ° C. or more and 50 ° C. or less. Also, 42W
Between the lamp, the 32W lamp and the 24W lamp, a comparator for comparing the level of a reference voltage corresponding to the voltage V3 with the output Vcf of the lamp voltage detection circuit 4, and a reference voltage corresponding to the voltage V4 and the lamp voltage detection circuit 4 By providing a comparator for comparing the level of the output Vcf with the output Vcf,
Both can be determined in a temperature range of 0 ° C. or more and 50 ° C. or less. Therefore, as compared with the case where the lamp rating is determined at the time of rated output, the difference in lamp voltage between the discharge lamps can be increased, the lamp rating of the discharge lamp can be determined over a wider temperature range, and the lamp characteristics can be determined. Even if the lamp voltage fluctuates to some extent due to variations in the lamp design or component design values, the rated power of the discharge lamp can be reliably determined.

In this embodiment, the lamp voltage is detected and
Although the rated power of the discharge lamp is determined from the detection result, the lamp current is detected as described in the second embodiment.
The rated power of the discharge lamp may be determined from the detection result.

(Embodiment 4) FIG. 1 shows Embodiment 4 of the present invention.
This will be described with reference to FIGS. In the discharge lamp lighting device of the third embodiment, one discharge lamp La is connected between both ends of the resonance capacitor C1, but in the present embodiment, the same type of discharge lamp La is connected between both ends of the resonance capacitor C1.
1 and La2 are connected in series with a plurality of lamps (for example, two lamps in the present embodiment) to form a load circuit unit. Since the configuration other than the discharge lamps La1 and La2 is the same as that of the third embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

As described above, in the present embodiment, since two discharge lamps La1 and La2 of the same type are connected in series to constitute a load circuit section, the discharge lamps La1 and La2
Is about twice the lamp voltage Vla for one lamp.

FIG. 12 shows the ballast VI characteristics and the lamp VI characteristics when one discharge lamp is used. FIG. 13 shows the ballast VI characteristics and the lamp VI characteristics when two discharge lamps are used. Is shown. A and B in FIG. 12 and FIG.
Are the lamp VI characteristics of the discharge lamps LA and LB, respectively, and points a2 and b2 are the operating points when the discharge lamps LA and LB are operated near the lower limit of dimming, respectively. Here, when two discharge lamps LA or LB are connected in series, the lamp voltage Vla2 is about twice as large as that of one lamp, and therefore, the lamp voltage Vla2 of the discharge lamp LB at the operating point a2 and the lamp voltage Vla2 at the operating point b2 Since the difference from the lamp voltage Vla2 of the discharge lamp LB increases, the rated power of the discharge lamp can be reliably determined without being affected by the temperature characteristics, the lamp characteristics, and the variations of the components of the lamp voltage Vla2.

In this embodiment, the resonance capacitor C1 is used.
Although two discharge lamps La1 and La2 are connected in series between both ends of the discharge lamp, three or more discharge lamps may be connected in series, and by increasing the number of discharge lamps, different types of discharge lamps The difference in lamp voltage near the lower limit of dimming can be increased, and the rated power of the discharge lamp can be reliably determined.

(Embodiment 5) FIG. 1 shows Embodiment 5 of the present invention.
4 and FIG. In the discharge lamp lighting device according to the fourth embodiment, two discharge lamps La1 and La2 are connected in series between both ends of the resonance capacitor C1 to form a load circuit unit. A plurality of discharge lamps La1 and La2 of the same type are connected in parallel between both ends of C1 (for example, two in this embodiment) to form a load circuit section. Further, in the circuit of the present embodiment, a current transformer CT is provided in a path where the lamp current Ila2 flows, and a lamp current detection circuit 4b that converts the lamp current Ila2 into a voltage using the current transformer CT, and an output of the lamp current detection circuit 4b. The lamp rating detector 4 is composed of the comparator CP1 that compares the level of Vcf with the reference voltage E1. The configuration other than the discharge lamps La1 and La2 and the lamp rating detector 4 is the same as that of the fourth embodiment, and the configuration of the lamp rating detector 4 is the same as that of the second embodiment. And the description thereof is omitted.

As described above, in the present embodiment, since two discharge lamps La1 and La2 of the same type are connected in parallel, the sum Ila2 of the lamp currents flowing through the discharge lamps La1 and La2 is equal to one. Is about twice the lamp current Ila.

FIG. 15 shows the ballast VI characteristics and the lamp VI characteristics of this circuit. The discharge lamp lighting device of the present embodiment is used by connecting any one of two types of discharge lamps LA and LB having substantially equal rated currents and different rated powers. B indicates the lamp VI characteristics of the discharge lamps LA and LB, respectively, and points a1 and b1
Are rated operating points of the discharge lamps LA and LB, respectively.

Further, W1 in FIG. 15 is the ballast VI characteristic immediately after the lamp is started, and W2 in FIG. 15 is the ballast VI characteristic at the lower limit of dimming of the discharge lamp. Here, in this embodiment, two discharge lamps La of the same type are used.
1 and La2 are connected in parallel, and the lamp current Ila2 in the case of two lamps is about twice as large as the lamp current Ila in the case of one lamp. Therefore, there are two types of lamp currents near the rated output. Does not change much between the discharge lamps LA and LB,
Since the difference between the lamp currents near the lower limit of dimming is large, it is easy to determine the rated power, and the rated power of the discharge lamp can be reliably determined without being affected by the temperature characteristics of the lamp current, lamp characteristics, and variations in parts. Can be determined.

In this embodiment, the resonance capacitor C1 is used.
Although two discharge lamps La1 and La2 are connected in parallel between both ends of the lamp, three or more discharge lamps may be connected in parallel, and by increasing the number of discharge lamps, different types of discharge lamps can be used. The difference in lamp current near the lower limit of dimming can be increased, and the rated power of the discharge lamp can be reliably determined.

(Embodiment 6) FIG. 16 is a circuit diagram of a discharge lamp lighting device according to this embodiment. In the discharge lamp lighting device according to the third embodiment, the resonance inductor L is connected between both ends of the low-side switching element Q2 via the DC cut capacitor C2.
1 and a series circuit of the resonance capacitor C1 are connected, and the discharge lamp La is connected in parallel with the resonance capacitor C1. First
Resonance inductor L3 and first resonance capacitor C
4 is connected, a series circuit of the second resonance inductor L1 and the second resonance capacitor C1 is connected between both ends of the first resonance capacitor C4, and the second resonance capacitor C1 is further connected. And a discharge lamp La is connected in parallel. That is, in this circuit, the inverter circuit 2
Is connected to a double resonance circuit composed of the resonance inductors L1 and L3 and the resonance capacitors C1 and C4, so that there are two no-load resonance frequencies.
Note that the configuration other than the double resonance circuit including the resonance inductors L1 and L3 and the resonance capacitors C1 and C4 is the same as that of the third embodiment. Is omitted.

FIG. 18 shows the frequency characteristic (Vf characteristic) of the lamp voltage Vla with respect to the operating frequency of the inverter circuit 2 of the discharge lamp lighting device described in the first to fifth embodiments.
18 shows frequency characteristics (W-f characteristics) of the lamp power Wla, F in FIG. 18 shows Vf characteristics and W-f characteristics at no load, and G in FIG. V-
The f characteristic and the Wf characteristic are shown.

Here, the operation of the inverter circuit 2 at the time of starting lighting will be described with reference to FIG. First, the inverter control circuit 3 sets the operating frequency f of the inverter circuit 2 to a frequency f1 sufficiently higher than the no-load resonance frequency f0 to preheat the filament, and then the lamp voltage Vla is necessary to start the discharge lamp La. The operating frequency f of the inverter circuit 2 is reduced until the voltage becomes
Point b). When the discharge lamp La starts, the lamp impedance decreases, the lamp voltage Vla decreases, and the Wf characteristic becomes G in FIG. 18 (point b → point c). Discharge lamp L
After lighting of a, in order to detect the rated power of the discharge lamp La, the inverter control circuit 3 raises the operating frequency f of the inverter circuit 2 to f2 (from point c to point d). , The operating frequency f is reduced to the operating frequency at the rated output, that is, the no-load resonance frequency f0 (point d → point e).

As described above, in the discharge lamp lighting devices of the first to fifth embodiments, the operating frequency f of the inverter circuit 2 is changed to f to detect the rated power of the discharge lamp La after the lamp is started.
2, the lamp power Wla was reduced during this period, and the light output was reduced. That is, at each stage of preheating, starting, lighting, dimming (lamp rating detection), and lighting, the light output of the discharge lamp La is changed from high to low to high, and once decreased, the user feels discomfort. was there.

In order to eliminate such a problem, a double resonance circuit is connected to the output terminal of the inverter circuit 2 in this embodiment. FIG. 17 shows the frequency characteristic (V
-F characteristic) and the frequency characteristic of the lamp power Wla (Wf characteristic). Further, F in FIG. 17 indicates Vf characteristics and Wf characteristics at no load, and FIG.
G in 7 indicates the Vf characteristic and the Wf characteristic after the lamp is turned on.

In the discharge lamp lighting device according to the present embodiment, since the double resonance circuit is connected to the output terminal of the inverter circuit 2, there are two no-load resonance frequencies f0 and f0 '(f0 <F0 ′), the lower no-load resonance frequency f0 is the operating frequency at the time of rated output.

Here, the operation of the inverter circuit 2 at the time of starting lighting will be described with reference to FIG. First, the inverter control circuit 3 sets the operating frequency f of the inverter circuit 2 to a frequency f1 sufficiently higher than the no-load resonance frequency f0 to preheat the filament, and then the lamp voltage Vla is necessary to start the discharge lamp La. The operating frequency f of the inverter circuit 2 is reduced until the voltage becomes
Point b). When the discharge lamp La starts, the lamp impedance decreases, the lamp voltage Vla decreases, and the Wf characteristic becomes G in FIG. 17 (point b → point c). At this time, since the operating frequency f of the inverter circuit 2 is sufficiently higher than the operating frequency f0 at the time of rated output, the rated power of the discharge lamp La is detected in this state. After the detection of the rated power, the operating frequency f is reduced to the operating frequency at the time of the rated output, that is, the no-load resonance frequency f0 (point c → point d). Therefore, at each stage of preheating, starting, lighting, dimming (lamp rating detection), and lighting, the discharge lamp La
The light output becomes low → high.

As described above, in the present embodiment, the double resonance circuit is connected to the output terminal of the inverter circuit 2, and when the discharge lamp La starts, the operating frequency f of the inverter circuit 2 becomes the operation at the rated output. Since the frequency is sufficiently higher than the frequency f0, the detection operation of the lamp rating can be performed in this state. By increasing the operating frequency after the start as in the discharge lamp lighting devices of Embodiments 1 to 5, ,
The light output of the discharge lamp La does not decrease temporarily, and it is possible to prevent the user from feeling uncomfortable.

In this embodiment, the lamp voltage is detected and
Although the rated power of the discharge lamp is determined from the detection result, the lamp current is detected as described in the second embodiment.
The rated power of the discharge lamp may be determined from the detection result.

(Embodiment 7) Embodiment 7 of the present invention is shown in FIG.
This will be described with reference to FIG. Since the circuit configuration of the discharge lamp lighting device of the present embodiment is the same as that of the discharge lamp lighting device of the first embodiment, illustration and description are omitted.

FIG. 19 shows the frequency characteristic (Vf characteristic) of the lamp voltage Vla with respect to the operating frequency of the inverter circuit 2, and
19 shows the frequency characteristics (Wf characteristics) of the lamp power Wla, where F in FIG. 19 is the Vf characteristics and Wf characteristics at no load, and G in FIG. 19 is V after the lamp rating is detected. −f
The characteristics and the Wf characteristics, and H in FIG. 19 indicate the Vf characteristics and the Wf characteristics when the lamp rating is detected, respectively. In the present embodiment, the switching elements Q1, Q
Since the on-duty of No. 2 is unbalanced and the on-duty is set to approximately 50% at the time of lamp rating detection and at the time of rated output, the lamp power Wla decreases at the time of lamp starting as compared with the lamp rating detection, and the discharge lamp La Although lit, the light output is low. The operating frequency f of the inverter circuit 2 at the time of rated output is the no-load resonance frequency f0.

Here, the operation of the inverter circuit 2 at the time of starting lighting will be described with reference to FIG. First, the inverter control circuit 3 sets the operating frequency f of the inverter circuit 2 to a frequency f1 sufficiently higher than the no-load resonance frequency f0 to preheat the filament, and then the lamp voltage Vla is necessary to start the discharge lamp La. The operating frequency f of the inverter circuit 2 is reduced until the voltage becomes
Point b). When the discharge lamp La starts, the lamp impedance decreases, the lamp voltage Vla decreases, and the Wf characteristic becomes H in FIG. 19 (point b → point c). Here, when starting the lamp, the lamp power Wla is reduced by setting the on-duty of the switching elements Q1 and Q2 to be unbalanced, so that the light output of the discharge lamp La is small.

Thereafter, in order to detect the rated power of the discharge lamp La, the inverter control circuit 3 raises the operating frequency f of the inverter circuit 2 to f2 and changes the on-duty of the switching elements Q1 and Q2 from the unbalanced state to the approximate state. 50% and the V of inverter circuit 2
The −f characteristic and the Wf characteristic become G in FIG. 19, and the operating frequency f of the inverter circuit 2 can be increased to f2 without changing the lamp power Wla (that is, the light output) (from the point c to the point d). ). After the detection of the rated power, the inverter control circuit 3 lowers the operating frequency f to the operating frequency at the rated output, that is, the no-load resonance frequency f0 (point d → point e).

As described above, in the present embodiment, when the lamp rating is detected, the operating frequency f of the inverter circuit 2 is increased to f2, so that the discharge lamps having substantially the same rated voltage and different rated power, or The difference in lamp voltage or lamp current between discharge lamps having substantially the same rated current and different rated power can be increased, and the rated power can be easily determined. In addition, when the lamp rating is detected, the operating frequency f of the inverter circuit 2 is increased to f2, and the on-duty of the switching elements Q1 and Q2 is changed from an unbalanced state to approximately 50%, so that the light output of the discharge lamp La is substantially constant. , The light output does not darken once, and the user does not feel uncomfortable.

In the present embodiment, the on-duty of the switching elements Q1 and Q2 is imbalanced immediately after the lamp is started, and the on-duty is reduced by approximately 50% when the lamp rating is detected.
And the operating frequency f of the inverter circuit 2 is increased to prevent the light output from lowering. However, the output voltage V
By keeping dc low and increasing the output voltage Vdc of the DC power supply 1 when the lamp rating is detected and setting it to be substantially the same as the voltage at the rated output, the lamp power Wla (that is, the light output) is kept substantially constant. You may do it.

In this embodiment, the lamp voltage is detected, and the rated power of the discharge lamp is determined from the detection result. However, as described in the second embodiment, the lamp current is detected, and the discharge current is detected from the detection result. The rated power of the lamp may be determined.

(Embodiment 8) Embodiment 8 of the present invention is shown in FIG.
This will be described with reference to FIG. In the present embodiment, in the discharge lamp lighting device of the third embodiment, a latch circuit 9 for latching the output of the lamp rating detection unit 4 input via the switch SW, and the output of the lamp voltage detection circuit 4a and a predetermined threshold value A lamp abnormality detection circuit (lamp abnormality detection unit) 10 for detecting an abnormal state such as end of life, overvoltage or Emiless by comparing the level with the value voltage Vth, and a threshold voltage Vth And a threshold setting circuit (threshold setting unit) 12 for changing the threshold voltage. Since the configuration other than the latch circuit 9, the lamp abnormality detection circuit 10, and the threshold value setting circuit 12 is the same as that of the third embodiment, the same components are denoted by the same reference numerals, and description thereof will be omitted. .

The lamp abnormality detection circuit 10 has a comparator CP2 in which the output voltage of the lamp voltage detection circuit 4a is input to the minus terminal and the threshold voltage Vth is input to the plus terminal. The comparator C determines the level of the output voltage and the threshold voltage Vth of the comparator 4a.
By comparing at P2, abnormality detection such as end-of-life detection, overvoltage detection, and Emiless detection is performed.

The threshold value setting circuit 12 includes a reference power supply E2 having a variable output voltage, a series circuit of resistors R4, R5 and R6 connected between both ends of the reference power supply E2, and a collector and a resistor connected between both ends of the resistor R6. A transistor Tr1 whose emitter is connected and whose base is connected to the output terminal of the latch circuit 9
And outputs the voltage at the connection point between the resistors R4 and R5 to the lamp abnormality detection circuit 10 as the threshold voltage Vth.
Here, in a plurality of types of discharge lamps La having different rated powers, the abnormality detection level is different for each lamp.
In the present embodiment, the threshold setting circuit 12 automatically changes the threshold voltage Vth in accordance with the detection result of the lamp rating detector 4, so that abnormality detection is performed for a plurality of discharge lamps La having different rated powers. It can be performed.

FIG. 21 shows the lamp VI characteristics of two types of discharge lamps LA and LB having different rated powers, and the ballast VI.
And characteristics. Note that A and B in FIG. 21 indicate the lamp VI characteristics of the discharge lamps LA and LB, respectively, and points a1 and b1 indicate the rated operating points of the discharge lamps LA and LB, respectively. Here, it is assumed that the threshold voltage for detecting the end-of-life state of the discharge lamp LA is V1, and the threshold voltage for detecting the end-of-life state of the discharge lamp LB is V2 (V1> V2). ).

Further, W1 in FIG. 21 indicates a ballast VI characteristic when the lamp is turned on, and W2 in FIG. 21 indicates a ballast VI characteristic when the lamp rating is detected. Each discharge lamp LA, LB Points a2 and b2 where the lamp VI characteristics (A, B) and the ballast VI characteristics (W2) at the time of lamp rating detection indicate operating points at the time of lamp rating detection of the discharge lamps LA and LB, respectively. ing. Here, in the lamp rating detecting section 4, a voltage V lower than the lamp voltage at the point a2 and higher than the lamp voltage at the point a3 is used.
3 is set as the reference voltage E1.

In the discharge lamp lighting device of the present embodiment, the operation of detecting the lamp rating is performed with the output of the inverter circuit 2 adjusted to the minimum output capable of maintaining the lighting state, and the discharge lamp LA is connected. Then, the output of the lamp voltage detection circuit 4a becomes higher than the reference voltage E1, so that the output of the comparator CP1 becomes L level. On the other hand, if the discharge lamp LB is connected, the lamp voltage detection circuit 4a
Is lower than the reference voltage E1, the output of the comparator CP1 becomes H level.

In the lamp abnormality detection circuit 10, the comparator CP2 compares the output of the lamp voltage detection circuit 4a with the threshold voltage Vth. Here, when the output of the latch circuit 9 is at the L level, the transistor Tr1 is turned off, and the threshold voltage Vth becomes E2 × (R5 + R6).
/ (R4 + R5 + R6). On the other hand, when the output of the latch circuit 9 is at the H level, the transistor Tr1 is turned on, and both ends of the resistor R6 are short-circuited. The output is lower than when the output of the circuit 9 is at the L level. Therefore, the threshold voltage Vth when the output of the latch circuit 9 is at the L level is the voltage V1 in FIG. 21, and the threshold voltage Vth when the output of the latch circuit 9 is the H level is the voltage V2 in FIG. The resistance values of the resistors R4 to R6 and the reference power source E2
Of the discharge lamps LA, L
The threshold voltage Vth corresponding to B can be set.

Here, in this embodiment, the ballast VI characteristics of the inverter circuit 2 after starting the lamp are shown by W in FIG.
In the state where the characteristic is switched to the characteristic shown in FIG. 2, the operation of detecting the lamp rating is performed, and when the discharge lamp LA is mounted, the output of the lamp rating detecting unit 4 becomes L level. The output of the lamp rating detection unit 4 is input to the chopper control circuit 7, and the operating frequency f of the inverter circuit 2 is switched to f0 so that the discharge lamp LA operates at the rated operating point a1, and the output voltage Vdc of the DC power source 1 is changed. Lower.
Further, since the output of the lamp rating detector 4 is latched by the latch circuit 9, even after the switch SW is turned off, the L-level signal is continuously input to the base of the transistor Tr1, and the transistor Tr1 keeps the off state. I do.

When the transistor Tr1 is turned off, the threshold voltage Vth increases and is set to the above-described voltage V1. When the output of the ramp voltage detection circuit 4a exceeds the threshold voltage Vth, the output of the comparator CP1 goes low, and the chopper control circuit 7 sets the switching element Q
3, since the on / off of Q4 is stopped and the output of the DC power supply 1 is stopped, the discharge lamp LA is turned off.

As described above, in the threshold value setting circuit 12,
Since the value of the threshold voltage Vth is switched according to the output of the lamp rating detector 4, the threshold voltage Vth according to the rated power of the discharge lamp can be set, and an abnormal state of the lamp can be detected. .

(Embodiment 9) Embodiment 9 of the present invention is shown in FIG.
This will be described with reference to FIG. In the present embodiment, in the discharge lamp lighting device according to the third embodiment described above, the lamp rating detection unit 4
The chopper control circuit 7 comprises a one-chip microcomputer (hereinafter referred to as a microcomputer) 11.
Note that the configuration other than the microcomputer 11 is the same as that of the third embodiment.

In the present embodiment, the above-described lamp rating detector 4 and chopper control circuit 7 are constituted by the microcomputer 11. A reference voltage for determining a plurality of types of discharge lamps having different rated powers is set in the microcomputer 11, and the microcomputer 11 compares the lamp voltage Vla with a pre-stored reference voltage, thereby obtaining a plurality of types of discharge lamps. Since the discharge lamp is determined, various types of discharge lamps La can be determined without increasing the number of comparators. Therefore, the number of circuit components and the mounting area of the circuit components do not increase, and the dispersion of the components is small.
Even when the difference in lamp voltage or lamp current between discharge lamps having different rated powers is small, the rated power of the discharge lamp can be determined more accurately.

In the discharge lamp lighting device of each of the above-described embodiments, the power supply voltage varying section for changing the output of the DC power supply 1 and the lamp rating detecting section 4 may be constituted by the microcomputer 11, which is the same as described above. The effect is obtained.

[0105]

As described above, according to the first aspect of the present invention, a DC power supply having a variable output voltage and an inverter circuit for switching a DC voltage of the DC power supply by a switching element and converting the DC voltage to an AC voltage are provided. , Switching element on /
A load circuit including a control circuit unit for controlling turning off, a series circuit of a resonance capacitor and a resonance inductor connected between output terminals of the inverter circuit unit, and at least one discharge lamp connected in parallel to the resonance capacitor. Unit, and a lamp rating detection unit that detects the rated power of the discharge lamp included in the load circuit unit by detecting at least one of the lamp voltage or the lamp current, the detection result of the lamp rating detection unit In a discharge lamp lighting device that lights a plurality of types of discharge lamps having different rated powers by changing the output voltage of the DC power supply in accordance with the control circuit, the control circuit unit changes the operating frequency of the inverter circuit at the rated output to the no-load resonance. Frequency is set, and the operating frequency of the inverter circuit is different from the no-load resonance frequency when the lamp rating is detected. It is characterized by setting to the wave number.At rated output, the operating frequency of the inverter circuit is set to the no-load resonance frequency, but when the lamp rating is detected, the operating frequency of the inverter circuit is set to a frequency different from the no-load resonance frequency. Setting, the difference in lamp voltage or lamp current between a plurality of discharge lamps having substantially the same rated voltage and different rated power or between a plurality of discharge lamps having substantially the same rated current and different rated power. This has the effect that the rated power can be easily determined.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a DC power supply having a variable output voltage, and an inverter circuit for switching a DC voltage of the DC power supply by a switching element and converting the DC voltage into an AC voltage. A control circuit for controlling on / off of a switching element, a series circuit of a first resonance capacitor and a first resonance inductor connected between output terminals of the inverter circuit, and a first resonance capacitor A series circuit of a second resonance capacitor and a second resonance inductor connected between both ends of the first circuit, a load circuit section including at least one discharge lamp connected in parallel to the second resonance capacitor, and a lamp A lamp rating detector for detecting the rated power of the discharge lamp included in the load circuit by detecting at least one of the voltage and the lamp current; In a discharge lamp lighting device for lighting a plurality of types of discharge lamps having different rated powers by changing an output voltage of a DC power supply unit according to a detection result of a lamp rating detection unit, a control circuit unit includes: , The operating frequency of the inverter circuit section is set to a frequency different from the two no-load resonance frequencies, and the operating frequency is set to one of the two no-load resonance frequencies at the rated output, and the operation at the time of lamp rating detection is performed. The frequency is set to be almost the same as the operating frequency at the time of starting the lamp.The operating frequency of the inverter circuit is set to the no-load resonance frequency at the rated output, but the operation of the inverter circuit at the time of lamp rating is detected. Since the frequency is set to a frequency different from the no-load resonance frequency, the rated voltage is The difference in lamp voltage or lamp current can be increased between a plurality of discharge lamps or between a plurality of discharge lamps having substantially equal rated currents and different rated powers, so that the rated power can be easily determined. . In addition, the control circuit sets the operating frequency of the inverter circuit to substantially the same frequency when detecting the lamp rating and when starting the lamp, and sets the no-load resonance frequency when the lamp is turned on. The light output of the discharge lamp does not darken once before the lamp is turned on, and the difference between the light output at the time of starting the lamp and at the time of lighting and at the time of the rated detection is reduced so that the user does not feel discomfort. There is an effect that it can be prevented.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the output voltage of the DC power supply unit when the lamp rating is detected and the output voltage of the DC power supply unit at the time of rated output are set to substantially the same voltage. In addition to the effect of the invention of claim 1 or 2, the output voltage of the DC power supply unit is set to a voltage substantially equal to the output voltage at the rated output when detecting the lamp rating. This reduces the difference in light output between when the lamp is started and when it is turned on and when the rating is detected, thereby preventing the user from feeling uncomfortable.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the output voltage of the DC power supply unit at the time of detecting the lamp rating is set to a minimum voltage value at which the discharge lamp can maintain the lighting state. In addition to the effects of the first and second aspects of the present invention, the output voltage of the DC power supply unit is set to the minimum voltage value at which the discharge lamp can maintain the lighting state when the lamp rating is detected. The difference between the lamp voltage and the lamp current between the lamps is increased, so that the rated power can be easily determined.

According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the load circuit section is configured by connecting a plurality of discharge lamps of the same type in series or in parallel.
In addition to the effects of the first to fourth aspects of the present invention, since a plurality of discharge lamps are connected in series or in parallel, a difference in lamp voltage or lamp current between a plurality of discharge lamps having different rated powers increases. Thus, there is an effect that the rated power can be easily determined.

According to a sixth aspect of the present invention, in the first to fifth aspects, the inverter circuit section has a series circuit of first and second switching elements connected between output terminals of the DC power supply section. The control circuit unit sets the on-duty of the first and second switching elements to approximately 50% at the time of detecting the lamp rating and at the time of rated output, and sets the on-duty of the first and second switching elements at the time of starting the lamp. The on-duty is set to a value different from the on-duty at the time of detecting the lamp rating. Is set to approximately 50%, but when the lamp is started, the on-duty is set to a value different from that when the lamp rating is detected. The output of the inverter circuit can be increased when the lamp is started and when the lamp is lit, compared to when the lamp is started.Therefore, the light output of the discharge lamp does not temporarily decrease from the time the lamp is started until the lamp is lit. There is an effect that the difference in light output between the time and the time of the rated detection is reduced, so that the user can be prevented from feeling uncomfortable.

[0111] The invention of claim 7 is the invention of claims 1, 2, 3, 5
In the invention according to the sixth aspect, the output voltage of the DC power supply unit at the time of starting the lamp is set to a voltage lower than the output voltage at the time of rated output, and the output voltage of the DC power supply unit at the time of lamp rating detection is set to the output voltage at the rated output. The voltage is set to be substantially the same as
In addition to the effects of the invention of 3, 5 or 6, the output voltage of the DC power supply unit at the time of starting the lamp is set to a voltage lower than the rated output,
At the time of lamp rating detection, the voltage is set to approximately the same as at the time of rated output, so that when detecting the rated power of the discharge lamp after starting, it is possible to suppress a decrease in the light output of the discharge lamp. There is an effect that the difference in light output from that at the time of rating detection can be reduced to prevent the user from feeling uncomfortable.

The invention of claim 8 is the invention according to claims 1 to 7, wherein at least one of the lamp voltage or the lamp current and a predetermined threshold value determined by the rated power of the discharge lamp. By comparing the threshold value with the rated power of the discharge lamp included in the load circuit unit based on the detection result of the lamp abnormality detection unit that detects the abnormal state of the discharge lamp and the lamp rating detection unit. A threshold setting unit for setting a value, wherein in addition to the effects of the inventions of claims 1 to 7, the lamp abnormality detection unit sets at least one of a lamp voltage and a lamp current. The abnormal state of the discharge lamp is detected by comparing the level with the threshold value, and the threshold value setting section changes the threshold value according to the detection result of the lamp rating detection section. , It is possible to automatically set a threshold value depending on the rated power of the connected discharge lamp, there is an effect that can be reliably detected an abnormality of the discharge lamp.

According to a ninth aspect of the present invention, in the first to eighth aspects of the present invention, the power supply voltage varying section for changing the output voltage of the DC power supply section and the lamp rating detecting section are constituted by a one-chip microcomputer. In addition to the effects of the first to eighth aspects of the present invention, the circuit configuration does not need to be significantly changed even when the type of the discharge lamp that can be distinguished is changed or increased, and the mounting area of the circuit components is reduced. There is an effect that it can be made smaller.

According to a tenth aspect of the present invention, in the first to ninth aspects of the present invention, the discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting having a rated power of 24 W or a high-frequency dedicated fluorescent lamp having a rated power of 32 W. 10. The compact fluorescent lamp according to claim 1, wherein the lamp rating detecting unit performs the detecting operation in a temperature range where the ambient temperature of the discharge lamp is approximately 0 ° C. or more and approximately 50 ° C. or less. The same effect as that of the invention of FIG.

According to an eleventh aspect of the present invention, in the first to ninth aspects of the present invention, the discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting having a rated power of 32 W or a high-frequency lighting dedicated type having a rated power of 42 W. Wherein the lamp rating detection unit performs a detection operation in a temperature range where the ambient temperature of the discharge lamp is approximately (−10) ° C. or more and approximately 50 ° C. or less. The same effects as those of the inventions 1 to 9 can be obtained.

According to a twelfth aspect of the present invention, in the first to ninth aspects of the present invention, the discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting having a rated power of 24 W, and a compact fluorescent lamp dedicated to high-frequency lighting having a rated power of 32 W. Shaped fluorescent lamp,
Alternatively, the lamp comprises a discharge lamp of at least one of compact fluorescent lamps exclusively used for high-frequency lighting with a rated power of 42 W, and the lamp rating detection unit has an ambient temperature of the discharge lamp of about 10 ° C. or more and about 50 ° C. or less. The detection operation is performed in the above temperature range, and the same effects as those of the first to ninth inventions are obtained.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram of a discharge lamp lighting device according to a first embodiment.

FIG. 2 is a circuit diagram of the same.

FIG. 3 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 4 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 5 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 6 is a circuit diagram of a discharge lamp lighting device according to a second embodiment.

FIG. 7 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 8 is a circuit diagram of a discharge lamp lighting device according to a third embodiment.

FIG. 9 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 10 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 11 is a circuit diagram of a discharge lamp lighting device according to a fourth embodiment.

FIG. 12 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 13 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 14 is a circuit diagram of a discharge lamp lighting device according to a fifth embodiment.

FIG. 15 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 16 is a circuit diagram of a discharge lamp lighting device according to a sixth embodiment.

FIG. 17 is an explanatory diagram illustrating frequency characteristics of a lamp voltage and a lamp power according to the embodiment.

FIG. 18 is an explanatory diagram illustrating frequency characteristics of lamp voltage and lamp power of the discharge lamp lighting devices according to the first to fifth embodiments.

FIG. 19 is an explanatory diagram illustrating frequency characteristics of lamp voltage and lamp power of the discharge lamp lighting device according to the seventh embodiment.

FIG. 20 is a circuit diagram of a discharge lamp lighting device according to an eighth embodiment.

FIG. 21 is an explanatory diagram showing a relationship between a lamp VI characteristic and a ballast VI characteristic of the discharge lamp used in the above.

FIG. 22 is a circuit diagram of a discharge lamp lighting device according to a ninth embodiment.

FIG. 23 is an explanatory diagram showing a relationship between a lamp voltage and an ambient temperature when a lamp rating of a conventional discharge lamp lighting device is detected.

FIG. 24 is an explanatory diagram illustrating a relationship between a lamp voltage and an ambient temperature when a lamp rating is detected in the discharge lamp lighting device according to the third embodiment.

FIG. 25 is a circuit diagram of a conventional discharge lamp lighting device.

FIG. 26 shows a ballast VI characteristic and a lamp VI of the above.
FIG. 4 is an explanatory diagram showing characteristics.

FIG. 27 is an explanatory diagram showing lamp VI characteristics of the discharge lamp used in the above.

FIG. 28 is an explanatory diagram showing lamp VI characteristics of the discharge lamp used in the above.

FIG. 29 is an explanatory diagram showing lamp VI characteristics of the discharge lamp used in the above.

FIG. 30 is a diagram showing the relationship between the lamp voltage and the ambient temperature of the discharge lamp used in the above.

[Explanation of symbols]

 Reference Signs List 1 DC power supply 2 Inverter circuit 3 Inverter control circuit 4 Lamp rating detection unit 5 Power supply voltage variable circuit C1 Resonant capacitor L1 Resonant inductor La Discharge lamp Vla Lamp voltage

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Minoru Yamamoto 1048 Kazuma, Kadoma, Osaka Prefecture F-term in Matsushita Electric Works, Ltd. GC04 HA06 HA09 HA10

Claims (12)

[Claims] 1. A DC power supply having a variable output voltage, an inverter circuit for switching a DC voltage of the DC power supply by a switching element to convert the DC voltage into an AC voltage, and a control circuit for controlling on / off of the switching element. Unit, a series circuit of a resonance capacitor and a resonance inductor connected between output terminals of the inverter circuit unit, a load circuit unit including at least one discharge lamp connected in parallel to the resonance capacitor, and a lamp voltage or A lamp rating detection unit that detects the rated power of the discharge lamp included in the load circuit unit by detecting at least one of the lamp currents, and a DC power supply unit according to the detection result of the lamp rating detection unit. In a discharge lamp lighting device that lights a plurality of types of discharge lamps having different rated powers by changing an output voltage, a control circuit is used. The operating frequency of the inverter circuit is set to a no-load resonance frequency at the time of rated output, and the operating frequency of the inverter circuit is set to a frequency different from the no-load resonance frequency at the time of detecting the lamp rating. Lighting device. 2. A DC power supply having a variable output voltage, an inverter circuit for switching a DC voltage of the DC power supply by a switching element to convert the DC voltage into an AC voltage, and a control circuit for controlling on / off of the switching element. And a series circuit of a first resonance capacitor and a first resonance inductor connected between output terminals of the inverter circuit unit;
A series circuit of a second resonance capacitor and a second resonance inductor connected between both ends of the resonance capacitor of
At least one capacitor connected in parallel to the second resonance capacitor
A load circuit unit including a discharge lamp of the lamp, and a lamp rating detection unit that detects the rated power of the discharge lamp included in the load circuit unit by detecting at least one of the lamp voltage or the lamp current, In a discharge lamp lighting device that lights a plurality of types of discharge lamps having different rated powers by changing an output voltage of a DC power supply according to a detection result of a lamp rating detector, a control circuit includes an inverter when starting the lamp. While setting the operating frequency of the circuit unit to a frequency different from the two no-load resonance frequencies,
A discharge lamp having an operating frequency set to one of two no-load resonance frequencies at a rated output, and an operating frequency set at the time of detecting a lamp rating set to substantially the same as an operating frequency at the time of starting the lamp. Lighting device. 3. The discharge lamp according to claim 1, wherein an output voltage of the DC power supply unit at the time of detecting the lamp rating and an output voltage of the DC power supply unit at the time of the rated output are set to substantially equal voltages. Lighting device. 4. The discharge lamp lighting device according to claim 1, wherein the output voltage of the DC power supply unit at the time of lamp rating detection is a minimum voltage value at which the discharge lamp can maintain a lighting state. 5. The discharge lamp lighting device according to claim 1, wherein the load circuit section is configured by connecting a plurality of discharge lamps of the same type in series or in parallel. 6. The inverter circuit section has a series circuit of first and second switching elements connected between output terminals of a DC power supply section, and the control circuit section detects when a lamp rating is detected and at a rated output. The on-duty of the first and second switching elements is set to approximately 50%, and the on-duty of the first and second switching elements at the time of starting the lamp is set to a value different from the on-duty at the time of detecting the lamp rating. The discharge lamp lighting device according to claim 1, wherein: 7. The output voltage of the DC power supply at the time of starting the lamp is set to a voltage lower than the output voltage at the time of rated output, and the output voltage of the DC power supply at the time of lamp rating detection is set to the output voltage at the time of rated output. The voltage is set to substantially the same voltage.
The discharge lamp lighting device according to any one of the above. 8. Comparing the level of at least one of the lamp voltage and the lamp current with a predetermined threshold value determined by the rated power of the discharge lamp,
A lamp abnormality detector for detecting an abnormal state of the discharge lamp;
A threshold setting unit configured to set the threshold to a value corresponding to a rated power of the discharge lamp included in the load circuit unit based on a detection result of the lamp rating detection unit. The discharge lamp lighting device according to any one of claims 1 to 7. 9. A discharge lamp lighting device according to claim 1, wherein a power supply voltage variable section for changing an output voltage of said DC power supply section and a lamp rating detection section are constituted by a one-chip microcomputer. . 10. The discharge lamp is one of a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 24 W and a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 32 W. The discharge lamp lighting device according to claim 1, wherein the unit performs the detection operation in a temperature range where the ambient temperature of the discharge lamp is approximately 0 ° C. or more and approximately 50 ° C. or less. 11. The discharge lamp is one of a compact fluorescent lamp exclusively for high-frequency lighting with a rated power of 32 W and a compact fluorescent lamp exclusively for high-frequency lighting with a rated power of 42 W. The discharge lamp lighting device according to claim 1, wherein the unit performs the detection operation in a temperature range where the ambient temperature of the discharge lamp is approximately (−10) ° C. or more and approximately 50 ° C. or less. 12. The discharge lamp is a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 24 W, a compact fluorescent lamp dedicated to high-frequency lighting with a rated power of 32 W, or a high-frequency lighting dedicated to high-frequency lighting with a rated power of 42 W. One of the compact fluorescent lamps, and the lamp rating detector detects that the ambient temperature of the discharge lamp is approximately 10 ° C. or more and approximately 5 ° C.
The discharge lamp lighting device according to claim 1, wherein the detection operation is performed in a temperature range of 0 ° C. or less.