JPH11176586A - Discharge lamp glowing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp glowing device for lighting a discharge lamp while preventing the lowering of lamp voltage at the time of low temperature. SOLUTION: As a discharge lamp L, FL40S/36 is used. A series circuit of a temperature sensitive resistor R0 having a characteristic that resistance thereof is lowered in response to the temperature lowering and a voltage dividing resistor R1 is connected between both ends of a smoothing capacitor C1 . Switching elements Q1 , Q2 are turned on/off each other by the control signal from a drive circuit IC. A comparator CP for comparing the both ends voltage of the resistor R1 with the reference voltage Vref is provided, and the output signal of the comparator CP is input to the drive circuit IC. The both ends voltage of the resistor R0 and the reference voltage Vref are set so as to be equal to each other at -5 deg.C of the peripheral temperature. When the signal from the comparator CP becomes a high level, the drive circuit IC controls the switching elements Q1 , Q2 so that the oscillation frequency of an inverter circuit comes to close to the resonance frequency.

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 apparatus for lighting a discharge lamp by converting a DC voltage into a high frequency voltage.

[0002]

2. Description of the Related Art Conventionally, there has been provided a discharge lamp lighting apparatus in which electric power is supplied from an AC power supply such as a commercial power supply and a discharge lamp as a load is lit with a high frequency output. A general fluorescent lamp (for example, FL40S or FLR40S) used in this type of discharge lamp lighting device includes:
A rare gas such as mercury and argon is sealed in a glass tube. For this reason, the characteristics of these fluorescent lamps are mainly determined by the vapor pressure of mercury in the glass tube, and the vapor pressure of the mercury is largely dependent on the ambient temperature. Is designed to obtain

For example, in FL40S, usually 6 mg of mercury is sealed, and the vapor pressure of mercury is 0.0012 hPa at 25 ° C., whereas it is 0.00018 hPa at 0 ° C. When the temperature changes from 25 ° C. to 0 ° C., the vapor pressure drops to about one-tenth. Therefore, when the ambient temperature of the fluorescent lamp decreases,
Since the partial pressure of mercury vapor with respect to argon decreases, the luminous efficiency of ultraviolet rays decreases, and the lamp voltage decreases. FIG. 12 shows the temperature dependence of the characteristics of the FL40S / 36 as an example. The horizontal axis in FIG. 12 is the ambient temperature, and the vertical axis is the relative value for each of the lamp current, lamp voltage, lamp power, and luminous flux when the value at an ambient temperature of 25 ° C. is 100%. Here, in FIG. 12, a (●) indicates the lamp current, B (○) indicates the lamp voltage, C (□) indicates the lamp power, and d (△) indicates the luminous flux. From FIG. 12, FL40
With SS / 36, it can be seen that when the ambient temperature drops from 25 ° C. to −10 ° C., the lamp voltage drops to a value of 60%.

[0004] Such a tendency largely depends on the composition of the mixed gas when a rare gas (for example, krypton) which is heavier than argon is contained as the rare gas sealed in the glass tube. For example, a power saving fluorescent lamp FL
40SS / 36 (Matsushita Electric Industrial Co., Ltd.), TLD36W /
In No. 54 (manufactured by Philips), a mixed gas is sealed in a glass tube, and the mixed gas contains 50% or more of krypton, and the rate of decrease in lamp voltage at low temperatures is large.

FIG. 13 shows FLR40S and FLR40S /
FIG. 6 is a characteristic comparison diagram when No. 36 is lit by the same discharge lamp lighting device. Here, in the FLR40S, argon is sealed in a glass tube as a rare gas, and in the FLR40S / 36, a mixed gas of argon and krypton is sealed in a glass tube as a rare gas. Note that the horizontal axis in FIG. 13 is the ambient temperature, and the vertical axis is the relative value for each of the lamp voltage and lamp current, where the value when the ambient temperature is 25 ° C. is 100%. Here, A in FIG. 13 indicates the lamp voltage of the FLR 40S, B indicates the lamp voltage of the FLR 40S / 36, C indicates the lamp current of the FLR 40S, and D indicates the lamp voltage of the FLR 40S / 36.
Are respectively shown. From FIG. 13, FLR4
0S and FLR40S / 36 both have relatively small dependence of the lamp current on the ambient temperature, but the lamp voltage is FL
It can be seen that the lamp voltage of R40S / 36 at low temperature becomes more remarkable than that of FLR40S. In other words, it can be seen that the fluorescent lamp in which the mixed gas of argon and krypton is sealed has a larger decrease rate of the lamp voltage at a low temperature than the fluorescent lamp in which argon is sealed.

In short, a fluorescent lamp for general lighting in which a mixed gas containing 50% or more of krypton is sealed in a glass tube, such as FLR40S / 36, has an ambient temperature of -10 ° C.
When the lamp is lit in an environment where
It is reduced to about 60% as compared with that at 5 ° C. That is, the lamp output decreases. By the way, the invention which suppresses a decrease in the lamp output of a fluorescent lamp at a low temperature is disclosed in JP-A-5-144417, JP-A-8-171995, JP-A-5-89989, and JP-A-4-296.
No. 496, Japanese Unexamined Patent Publication No. 7-94288, and the like.

[0007]

However, the invention described in JP-A-5-144417 discloses a copier,
Regarding a fluorescent lamp used as a light source for illumination of an image reader or the like, it is necessary to provide a heating element that generates heat by energization separately from a filament in a tube, and suppresses a decrease in lamp voltage at a low temperature of a fluorescent lamp for general lighting. No technical problem exists, and no solution is described.

The invention described in Japanese Patent Application Laid-Open No. H8-171995 is directed to a fluorescent lamp used as a backlight of a liquid crystal display device, and converts the output of a DC power supply into a DC rectangular wave. Power supply to the inverter circuit, and feeds back the change in the output voltage of the inverter circuit to the power control unit to change the duty ratio of the output of the power control unit. There is no technical problem of suppressing a decrease in the lamp voltage at the time of low temperature of the fluorescent lamp, and no solution is described.

The invention described in Japanese Patent Application Laid-Open No. 5-89989 relates to a cold-cathode tube lighting device in which a cold-cathode tube used as a backlight of a liquid crystal display device is used as a lamp, and a voltage resonance type inverter circuit is used as an inverter circuit. The technical problem of using a Royer circuit (push-pull type inverter) to control the output voltage of the inverter circuit at a low temperature with the input voltage, and to suppress a decrease in the lamp voltage of a fluorescent lamp for general lighting at a low temperature. Does not exist and no solution is described.

The invention described in Japanese Patent Application Laid-Open No. 4-296496 is capable of detecting the temperature of the tube wall of a fluorescent lamp and changing the power supplied from the inverter circuit to the fluorescent lamp in accordance with the tube wall temperature. Although it is described, specifically, it controls the inverter circuit so that the lamp current increases as the temperature decreases, and there is a technical problem of suppressing a decrease in the lamp voltage at a low temperature of the fluorescent lamp. No solution is described.

In the invention described in Japanese Patent Application Laid-Open No. 7-94288, a lighting system having a controller for dimming control is provided with a temperature detecting means for detecting an ambient temperature. The duty ratio of the dimming signal is changed depending on the setting state, and there is no description of a means for suppressing a decrease in lamp voltage at a low temperature.

The above publications do not disclose a technique for suppressing a decrease in the lamp voltage of a fluorescent lamp, such as a fluorescent lamp containing krypton as a rare gas, whose light output significantly decreases at low temperatures. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a discharge lamp lighting device capable of preventing a decrease in lamp voltage at a low temperature.

[0013]

According to a first aspect of the present invention, there is provided a DC power supply comprising: a DC power supply; and a DC power supply including an LC resonance circuit and a switching element. And a discharge lamp to which the output of the inverter circuit is supplied through the LC resonance circuit, wherein the discharge lamp has an ambient temperature of −10 ° C. with respect to the lamp voltage when the ambient temperature is 25 ° C. When the lamp voltage is 65
% And a temperature detecting means for detecting the ambient temperature of the discharge lamp, and an output correcting means for suppressing a decrease in the lamp voltage at a low temperature based on the ambient temperature detected by the temperature detecting means. It is characterized by,
Even when a discharge lamp having a lamp voltage value of 65% or less when the ambient temperature is −10 ° C. with respect to the lamp voltage when the ambient temperature is 25 ° C. is used, the lamp voltage at a low temperature can be reduced. Can be suppressed.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a control circuit for controlling the oscillation frequency of the inverter circuit by turning on / off the switching element by a control signal, and the output correction means comprises an output of the temperature detection means. , At least one of the cycle of the control signal and the on-duty is changed so that the lamp voltage increases at a low temperature. Therefore, the operation of the control circuit is changed at a low temperature to increase the lamp voltage.

According to a third aspect of the present invention, in the first aspect of the present invention, there is provided a control circuit for controlling an oscillation frequency of an inverter circuit by turning on / off a switching element by a control signal, and a CR circuit for setting a cycle of the control signal. And the CR circuit operates such that the oscillation frequency approaches the resonance frequency of the LC resonance circuit in response to a decrease in ambient temperature.
Since the temperature detecting means and the output correcting means are formed by components having a temperature characteristic in which the R time constant changes, the cycle of the control signal changes as the ambient temperature decreases, and the oscillation frequency of the inverter circuit becomes equal to the LC frequency. Since the resonance frequency approaches the resonance frequency of the resonance circuit, it is possible to suppress a decrease in the lamp voltage at a low temperature.

According to a fourth aspect of the present invention, in the first aspect of the invention, the LC resonance circuit is formed of a component having a temperature characteristic in which a resonance frequency changes so that a lamp voltage increases in accordance with a decrease in ambient temperature. Since the temperature detecting means and the output correcting means are configured, as the ambient temperature decreases, the resonance frequency of the LC resonance circuit changes and the lamp voltage increases.

According to a fifth aspect of the present invention, in the first aspect of the invention, the output correction means includes a switching means for switching a resonance frequency of the LC resonance circuit, and the lamp is controlled at a low temperature based on the ambient temperature detected by the temperature detection means. Since the switching means is controlled to increase the voltage, the LC
The resonance frequency of the resonance circuit switches and the lamp voltage increases.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the output correction means includes a heating means for heating the periphery of the discharge lamp, and the heating means operates at a low temperature based on the ambient temperature detected by the temperature detecting means. Since the operation is performed, at low temperatures, the ambient temperature of the discharge lamp increases due to heating by the heating means, and the lamp voltage increases. According to a seventh aspect of the present invention, in the first aspect of the invention, a fluorescent lamp in which a rare gas mixed with 50% or more of krypton is sealed is used as a discharge lamp, so that only argon is sealed as a rare gas. The lighting start voltage can be reduced as compared with the fluorescent lamp, and power can be saved.

The invention of claim 8 is characterized in that, in the invention of claim 7, a straight tube fluorescent lamp having a tube length of 1198 mm and a lamp rating of 36 W ± 4 W is used as the discharge lamp. According to a ninth aspect of the present invention, in the first aspect of the present invention, there is provided a control circuit for controlling ON / OFF of the switching element, wherein the output correction means adjusts the oscillation frequency of the inverter circuit at a low temperature based on the temperature detected by the temperature detection means. Since the operation of the control circuit is controlled so as to approach the resonance frequency of the LC resonance circuit, at a low temperature, the oscillation frequency of the inverter circuit approaches the resonance frequency of the LC resonance circuit, and the lamp voltage increases.

According to a tenth aspect of the present invention, in the first aspect, the inverter circuit includes a pair of switching elements connected between the output terminals of the DC power supply and an LC resonance element connected between both ends of one of the switching elements. A control circuit that alternately turns on and off both switching elements at a high frequency. The output correction means controls the on-duty of the switching elements to approach 50% when the temperature is low based on the ambient temperature detected by the temperature detection means. Since the control circuit is controlled, it is possible to suppress a decrease in the lamp voltage at a low temperature.

According to an eleventh aspect of the present invention, in the first aspect, the output correction means increases the power supply voltage of the inverter circuit at a low temperature based on the ambient temperature detected by the temperature detecting means. Can be suppressed. According to a twelfth aspect of the present invention, in the first aspect of the present invention, the output correction means is constituted by the LC resonance circuit, wherein a component having a negative temperature coefficient is used as a capacitor of the LC resonance circuit, and the capacitor is Since the temperature detecting means is formed, as the ambient temperature decreases, the resonance frequency of the LC resonance circuit changes and the lamp voltage increases.

[0022]

(Embodiment 1) In this embodiment,
It adopts a circuit configuration shown in FIG. 1, the AC power source AC to connect the rectifier DB consisting diode bridge, is connected to the smoothing capacitor C ₁ between the DC output ends of the rectifier DB. Further, a series circuit of a temperature-sensitive resistor R ₀ and a voltage dividing resistor R ₁ having a characteristic that the resistance value decreases as the temperature decreases is connected between both ends of the smoothing capacitor C _1. pair of switching elements Q ₁ is in, Q are connected in series circuit ₂ is, in the one switching element Q _1, the series circuit of the coupling capacitor C ₂ for the inductor L ₁ for resonance and the discharge lamp La DC cut There are connected, to the non-power supply side end of the discharge lamp La capacitor C ₃ for resonance of an LC resonance circuit together with the inductor L ₁ is connected. Here, as the temperature-sensitive resistor R ₀ , for example, ERS (trade name) manufactured by Matsushita Electric Industrial Co., Ltd. having the temperature characteristics shown in FIG.
A series may be used. The switching elements Q ₁ and Q ₂ have diodes D ₁ ,
D ₂ is connected in antiparallel. In the present embodiment, FL40SS / 36 is used as the discharge lamp La. Here, FL40SS / 36 has a tube in which a mixed gas of argon and krypton is sealed as a rare gas and the
It is a straight tube type fluorescent lamp having a tube length of 1198 mm (4 feet) and a lamp rating of 36 W ± 4 W. The fluorescent lamp used as the discharge lamp La is:
The fluorescent lamp is not limited to FL40SS / 36, but may be any fluorescent lamp in which a rare gas having a mass number larger than argon by 50% is abnormally contained in the tube.

The switching elements Q ₁ and Q ₂ are turned on and off alternately by a control signal from the drive circuit IC.
Incidentally, in the present embodiment, the comparator CP is provided to compare the voltage across the resistor R ₁ and the reference voltage Vref, the
The output signal of the comparator CP is a drive circuit IC (control circuit)
To be entered. The switching elements Q ₁ and Q ₂ , the drive circuit IC, the inductor L ₁ , the capacitor C ₃ and the capacitor C ₂ constitute a half-bridge type inverter circuit.

Hereinafter, the steady state of the discharge lamp lighting device having the configuration shown in FIG.
The operation will be described. The discharge lamp lighting device according to the present embodiment includes a switch.
Switching element Q₁, Q_TwoFrom the drive circuit IC
Discharge by turning on and off alternately at high speed by signal
The lamp La is turned on at a high frequency. Switching element
Child Q₁Is off, switching element Q_TwoIs on
Is a smoothing capacitor C₁With the voltage of
Capacitor C₁→ Inductor L₁→ Capacitor C_Three→ Ko
Capacitor C_Two→ Switching element Q_Two→ Smoothing capacitor
C ₁Current flows in the path of_TwoIs charged
You. At this time, the capacitor C _TwoIs the discharge lamp La
Is applied between the filaments.

[0025] When the switching element Q ₂ is turned off, a regenerative current flows due to the accumulation energy in the inductor L _1.
At this time, the inductor L ₁ → capacitor C ₃ → regenerative current flows through a path of the capacitor C ₂ → switching element to Q ₁ for regenerative diode D ₁ → inductor L _1. The switching element Q ₁ when the switching element Q ₂ is turned off is turned on.

[0026] regeneration by the inductor L ₁ current does not flow, the capacitor C ₂ as a power supply, a capacitor C ₂
→ charge of the capacitor C ₃ → inductor L ₁ → switching element Q ₁ → capacitor C ₂ and a current flows through a path of the capacitor C ₂ is discharged. At this time, the capacitor C
The polarity of the voltage generated at both ends of ₂ is inverted, and the direction of the current flowing through the discharge lamp La is inverted.

Thereafter, when the switching element Q ₁ is turned off, the state returns to a state in which a current flows using the smoothing capacitor C ₁ as a power supply, and the above-described operation is repeated in a steady state. Therefore, by alternately turning on and off the switching elements Q ₁ and Q ₂ at a high frequency, an alternating current flows through the discharge lamp La. By the way, the effective value of the lamp voltage of the FL40SS / 36 used as the discharge lamp La in this embodiment is about 100 V at the time of lighting when the ambient temperature is 25 ° C. as shown in FIG. However, when the ambient temperature reaches about −10 ° C., the voltage drops to about 60V. On the other hand, the light output (luminous flux) of the lamp is substantially proportional to the power consumption of the lamp, and the power consumption of the lamp is substantially equal to the product of the lamp current and the lamp voltage. Here, the discharge lamp La
Lamp current does not change much with changes in ambient temperature, but since the lamp voltage changes at a large rate with changes in ambient temperature, the light output is greatly affected by the dependence of the lamp voltage on the ambient temperature. 23).

However, in this embodiment, the ambient temperature
Resistance R decreases as resistance decreases₀And
Anti-R₁And the ambient temperature drops.
And the thermal resistance R₀Of the resistance R₁Of both ends
Voltage, that is, the voltage input to the non-inverting terminal of the comparator CP
Rises. Where the resistance R₁Is the reference voltage V
ref, the output signal of comparator CP is low level
Change to high level. The output signal of comparator CP is
The drive circuit IC is input to the
That the output signal of the comparator CP has changed to high level
Then, the oscillation frequency of the inverter circuit is shown in FIG.
F to f−Δf (arrow A in FIG. 3).₁Direction
Change the oscillation frequency at the same time), so the lamp voltage increases
And suppresses a decrease in lamp voltage due to a decrease in ambient temperature.
be able to. Also, as the lamp voltage increases,
The lamp output (illuminance) also increases in proportion to the pump voltage
The lamp output at low temperatures can be suppressed.
You. Here, the temperature-sensitive resistance R₀And resistance R₁Series circuit with
Of the comparator CP, the reference voltage Vref,
Live circuit IC lowers lamp voltage at low temperatures
This constitutes output correction means for suppressing the above. This implementation
In the configuration, when the ambient temperature is about −5 ° C., the resistance R ₁Both
A constant is set so that the terminal voltage and the reference voltage Vref are equal.
It has been set.

(Embodiment 2) In this embodiment, the configuration shown in FIG. 4 is adopted, and the basic configuration and basic operation are substantially the same as those in Embodiment 1, so that the same components are denoted by the same reference numerals. The differences will be described. In the first embodiment, a series circuit of the temperature-sensitive resistors R ₀ and R ₁ whose resistance value decreases as the ambient temperature decreases is connected between both ends of the smoothing capacitor C _1. across capacitor C ₁ resistor R ₁ and a negative characteristic thermistor Th
Is connected to the series circuit. In the circuit configuration of the present embodiment, when the ambient temperature of the discharge lamp La decreases, the resistance value of the negative characteristic thermistor Th increases, and the voltage input to the non-inverting terminal of the comparator CP increases. Here, when the voltage across the negative characteristic thermistor Th exceeds the reference voltage Vref, the comparator C
The output signal of P changes from low level to high level.
Therefore, an effect similar to that of the circuit configuration of FIG. 1 described in the first embodiment can be obtained. Here, a series circuit of a resistor R ₁ and a negative characteristic thermistor Th constitutes a temperature detecting means, the comparator CP, the reference voltage Vref, the drive circuit IC (control circuit)
Constitute the output correction means.

As the negative characteristic thermistor Th, for example, an N type manufactured by Matsushita Electric Industrial Co., Ltd. having a temperature characteristic shown in FIG.
The TC series may be used. Here, numerals 1 to 16 given to each straight line in FIG. 5 correspond to each part number of the NTC series. (Embodiment 3) The basic configuration and basic operation of this embodiment are substantially the same as those in FIG.
₀ and the series circuit of the resistor R _1, the instead of providing the comparator CP, and remembering temperature characteristic oscillation frequency of the drive circuit IC (control circuit), the point to suppress the decrease of the lamp output at low temperature are different. In the present embodiment, the drive circuit I
As C, for example, IR (International Rectifier)
Corporation) IR2155 may be used. In this case, the oscillation frequency f of the driver circuit IC is determined by the resistance RT connected between the second and third pins of the IR 2155 and the capacitor CT connected between the third and fourth pins shown in FIG. And f = 1 / (1.
4 × RT × CT). Here, in order to increase the lamp voltage at a low temperature, the oscillation frequency may be decreased as shown in FIG. 3 described above. To decrease the oscillation frequency, the resistance value of the resistor RT is increased or the capacitance of the capacitor CT is decreased. You just need to increase it. Therefore, the above-mentioned negative characteristic thermistor Th is used as the resistor RT, or
A film capacitor ECQP manufactured by Matsushita Electric Industrial Co., Ltd. having a characteristic of increasing the capacitance at low temperatures as shown in FIG.
By using a series, it is possible to suppress a decrease in the lamp voltage at a low temperature and also to suppress a decrease in the lamp output (illuminance). In this embodiment, the output correction means is constituted by the drive circuit IC, the resistor RT, and the capacitor CT.

(Embodiment 4) In the present embodiment, the configuration shown in FIG. 8 is employed, and the basic configuration and basic operation are substantially the same as those of the first embodiment. The differences will be described. In the first embodiment, a series circuit of the temperature-sensitive resistors R ₀ and R ₁ whose resistance value decreases as the ambient temperature decreases is connected between both ends of the smoothing capacitor C _1. resistor R ₁ and the silicon diode D across the capacitor C ₁
A series circuit of _three connected, and input the voltage across the silicon diode D ₃ to the non-inverting terminal of the amplifier to the comparator CP by the amplifier OP. Since the ON voltage of a silicon diode generally has a temperature coefficient of −2 mV / ° C., when the ambient temperature drops from 25 ° C. to −10 ° C.,
The forward voltage increases by 70 mV (= 2 × 35). Thus, for example, by setting the reference voltage Vref so that the reference voltage Vref and the output of the amplifier OP (a value obtained by amplifying the voltage across the silicon diode D ₃₎ when the ambient temperature is about -5 ° C. equal When the ambient temperature falls below −5 ° C., the output signal of comparator CP changes to a high level. When the signal input from the comparator CP becomes high level, the drive circuit IC lowers the oscillation frequency as in the first embodiment, so that the lamp voltage and light output of the discharge lamp La increase, and the lamp voltage and light output of the discharge lamp La increase. Reduction is suppressed.

In this embodiment, a series circuit of the resistor R ₁ and the silicon diode D ₃ constitutes a temperature detecting means, and an amplifier OP, a comparator CP, and a drive circuit IC (control circuit) constitute an output correcting means. doing. (Embodiment 5) In this embodiment, the configuration shown in FIG. 9 is adopted, and a high-frequency blocking filter NF is connected to the AC power supply AC.
A rectifier DB consisting of a diode bridge is connected via a rectifier, a high-frequency bypass capacitor C ₄ is connected between the DC output terminals of the rectifier DB, and an inductor L ₂ , a switching element Q ₃ and a diode D are connected to both ends of the capacitor C _{4. 13} ,
It is connected to step-up chopper circuit composed of the smoothing capacitor C _1. Here, the switching element Q ₃ are turned on and off by a control signal from the chopper control circuit IC _2. Further, between both ends of the smoothing capacitor C ₁ of the step-up chopper circuit, is connected to a series circuit of a resistor R ₁ of the temperature-sensitive resistor R ₀ which reduces the resistance value as the ambient temperature becomes lower dividing, the series circuit Is connected to a series circuit of a pair of switching elements Q ₁ and Q _2. One switching element Q ₁ includes a resonance inductor L ₁ , a discharge lamp La, and a DC cutting coupling capacitor C ₂ . A series circuit is connected, and the inductor L ₁ is connected to the non-power supply side end of the discharge lamp La.
Together with a resonance capacitor C which constitutes an LC resonance circuit.
₃ is connected. The switching elements Q ₁ , Q
₂ , diodes D ₁ and D ₂ for supplying a regenerative current are connected in anti-parallel.

The switching elements Q ₁ and Q ₂ are turned on and off alternately by a control signal from a drive circuit IC (control circuit). Further, the voltage across the resistor R ₁ and the reference voltage Vre
comparator CP is provided for comparing the f, the chopper control circuit IC ₂ is capable of controlling the ON time of the switching element Q ₃ based on the output of the comparator CP. In this embodiment, as in the first embodiment, a half-bridge type inverter circuit is configured by the switching elements Q ₁ and Q ₂ , the drive circuit IC, the inductor L ₁ , the capacitor C ₃ , and the capacitor C _2. I have.

The voltage across V _C1 of the smoothing capacitor C ₁ which is a power supply voltage of the inverter circuit, ton the on time of the switching element Q _3, the off-time of the switching element Q ₃ t
off, when the voltage across the capacitor C ₄ and V _C4, V _C1
= {(Ton + toff) / toff} × V _C4 .
Therefore, increasing the on-time ton of the switching element Q _3, the voltage across V _C1 of the smoothing capacitor C _1, that is, the power supply voltage of the inverter circuit increases. In the present embodiment, for example, when the ambient temperature is about −5 ° C., the resistance R ₁
If the reference voltage Vref is set so that the voltage between both ends becomes equal to the reference voltage Vref, the output signal of the comparator CP changes to a high level when the ambient temperature falls below -5 ° C. In the present embodiment, when the signal input from the comparator CP goes high, the chopper control circuit IC ₂
Because are so as to extend the on-time ton of the switching element Q _3, the voltage across V _C1 of the smoothing capacitor C ₁ is increased, the characteristics of the i of the lamp voltage of the discharge lamp La is 10 as a result b to characteristics of changes (characteristic changes to the arrow a ₂ direction), decrease in lamp voltage and the light output (luminance) is suppressed.

[0035] Here, in the case of using the MC34262 which is as a chopper control circuit IC ₂ for example Motorola general purpose IC is external resistor connected to the third pin connected to the MC34262 inside the multipliers shown in FIG. 11 R ₃₀ (see FIG. 12) and capacitor C ₃₀ (see FIG. 12)
Since the oscillation frequency is determined by the above value, the on-time ton can be controlled by changing at least one of the resistance R ₃₀ and the capacitor C ₃₀ .

[0036] In the present embodiment, to constitute a series circuit temperature detecting means and the temperature-sensitive resistor R ₀ of the resistance value decreases and the resistance R ₁ of dividing as the ambient temperature decreases, the comparator C
P, constitute an output correction unit by the chopper control circuit IC _2. In (Embodiment 6) In this embodiment, relatively small between the rectifier rectifier DC output ends of the smoothing capacitor C ₁ of the DB of the DB adopts a configuration shown in FIG. 13, the AC power source AC full-wave rectifier Yes inserting a parallel circuit of a capacitor C ₅ and the diode D ₅ volume, it is connected to a pair of the series circuit of the switching elements Q _1, Q ₂ across the smoothing capacitor C _1. Diode D ₅ is inserted in the direction of flow a charging current to the smoothing capacitor C ₁ from the rectifier DB, a cathode is connected to the negative pole of the DC output ends of the rectifier DB. Also,
An inductor L is connected to the connection point between the two switching elements Q ₁ and Q _2.
2 Connect one end to connect the series circuit of the discharge lamp La and the coupling capacitor C ₂ of the DC blocking between the cathode of the other end and the diode D ₅ of the inductor L _2, the more the discharge lamp La capacitor the C ₃ are connected in parallel. here,
The switching elements Q ₁ and Q ₂ are turned on and off alternately by a control signal from a drive circuit (control circuit) (not shown). In this embodiment, the switching elements Q ₁ and Q ₂ , the drive circuit, the inductor L ₂ , and the discharge lamp L
a, capacitor C ₃ , capacitor C ₅ , diode D ₅
Thus, a so-called charge pump type inverter circuit is formed.

In this configuration, both switching elements Q ₁ ,
When Q ₂ is controlled to alternately turned on and off, by the relationship of the voltage between both ends of the smoothing capacitor C ₁ and the voltage across the output voltage and Konden'na C ₅ of the rectifier DB, flowing a high frequency pulsed current from the rectifier DB AC power supply A
If a filter for blocking high frequency is provided between C and the rectifier DB, the input current waveform from the AC power supply AC can be made substantially continuous. That is, an increase in input current distortion can be suppressed.

In this circuit configuration, the condenser C_FiveCharge and discharge
Greatly contributes to increase of input current distortion from AC power supply AC
Therefore, this operation will be described in more detail. Steady
In operation, the switching element Q₁, Q_TwoOn-off one
The following six operations (1) to (6) during the cycle
There is a state. (1) Switching element Q₁Is on, switching element
Q_TwoIs off, the smoothing capacitor C₁Voltage across
Is higher than the output voltage of the rectifier DB and the capacitor C
_FiveIs smoothing capacitor C₁And output of rectifier DB
Voltage, the smoothing capacitor C₁The power
As a smoothing capacitor C₁→ Switching element Q₁→
Inductor L_Two→ Discharge lamp La, condenser C_Three→ Conde
Sensor C_Two→ Capacitor C_Five→ Smoothing capacitor C₁Path
, The resonance current flows, and the capacitor C _FiveIs charged.

[0039] (2) When the sum of the voltage across the capacitor C ₅ and the output voltage of the rectifier DB is higher than the voltage of the smoothing capacitor C _1, the rectifier DB → switching element Q ₁ → inductor L ₂ → discharge lamp La, the capacitor A current flows through a path of C ₃ → capacitor C ₂ → rectifier DB. This state continues until the switching element Q ₁ is turned off. (3) When the switching element device Q ₁ is turned off, a regenerative current flows due to the accumulation energy in the inductor L _2. That is, a regenerative current flows through a route of the rectifier DB → the smoothing capacitor C ₁ → the switching element Q ₂ → the inductor L ₂ → the discharge lamp La, the capacitor C ₃ → the capacitor C ₂ → the rectifier DB. Current flowing through the switching element Q ₂ is, through the fact diode for regenerative provided in parallel to the switching element Q ₂ (not shown). In this state, the input current from the AC power supply AC flows. The switching element Q ₂ When the switching element Q ₁ is turned off is turned on.

(4) Inductor L_TwoRegenerative current flows
No longer, the capacitor C_ThreeAs the power supply,
Sa C_Two→ Discharge lamp La, condenser C_Three→ Inductor L_Two
→ Switching element Q_Two→ Capacitor C_Five→ Capacitor
C_TwoCurrent flows in the path_FiveCharging power
The load is discharged. (5) Capacitor C_FiveAfter discharging the capacitor C_Two→ release
Light La, condenser C_Three→ Inductor L_Two→ Switch
Element Q_Two→ Diode D_Five→ Capacitor C _TwoThat
Current flows through the path.

[0041] (6) Thereafter, when the switching element Q ₂ is turned off, regeneration by the energy stored in the inductor L ₂ current, the capacitor C ₂ → discharge lamp La, the capacitor C ₃
→ Inductor L ₂ → Switching element Q ₁ → Smoothing capacitor C ₁ → Diode D ₅ → Capacitor C ₂ Current flowing through the switching element Q ₁ is, through the fact diode for regenerative provided in parallel to the switching element Q ₁ (not shown). The switching element Q ₁ is turned on when the switching element Q ₂ is turned off.

[0042] When the regeneration by the inductor L ₂ current does not flow, returns to the state where a current flows to the smoothing capacitor C ₁ as a power source, it means that the above-mentioned operation is repeated in a steady state, the current to the discharge lamp La that alternating is flow, also, since the period to flow the input current from the AC power source AC in each cycle of turning on and off of the switching element Q _1, Q ₂ occurs by turning on and off the switching elements Q _1, Q ₂ at a high frequency, high-frequency input current It can be washed away. Here, the rectifier crests of the output voltage waveform of the DB (the vicinity of the peak value) In the above (1), since the time of operation mode (4) is shortened, LC resonant circuit is only the capacitor C ₃ and the inductor L ₂ (Hereinafter referred to as a first resonance system), and has resonance characteristics as shown in FIG. Conversely, troughs of the output voltage waveform of the rectifier DB (zero volts vicinity) In the above (1), since the time of operation mode (4) becomes longer, LC resonant circuit capacitor C ₃ and the capacitor C ₅ and the inductor L _{A second} resonance system (hereinafter, referred to as a second resonance system) has resonance characteristics as shown in FIG. That is, the resonance characteristics are different between the peak and the valley of the output voltage waveform of the rectifier DB. Therefore, when the oscillation frequency of the inverter circuit is f = constant (see FIG. 14), the current flowing through the discharge lamp La differs between the peak and the valley of the output voltage waveform of the rectifier DB. Further, the ratio of the first resonance system and the second resonance system operating in one cycle of ON / OFF of the switching elements Q ₁ and Q ₂ varies depending on the voltage level of the output voltage of the rectifier DB. Figure 1
A high-frequency current having an envelope as shown in FIG. Here, a “valley” portion in FIG. 15 indicates a lamp current when the output voltage waveform of the rectifier DB is a valley, and a “peak” in FIG.
Indicates a lamp current when the output voltage waveform of the rectifier DB is a peak. That is, the lamp current flowing through the discharge lamp La has a rippled waveform as shown in FIG.

Therefore, even when the fluorescent lamp (FL40SS / 36) in each of the above embodiments is used as the discharge lamp La, it is possible to prevent the occurrence of moving stripes and the flicker at low temperatures. By the way, in the present embodiment, IR2111 manufactured by IR is used as a drive circuit (control circuit) for turning on and off the switching elements Q ₁ and Q ₂ alternately. As a control integrated circuit for generating a pulse voltage to be input to the IR2111, AN6768K manufactured by Matsushita Electronics Corporation shown in FIG. 16 is used. Here, the oscillation frequency of the inverter circuit is determined by the magnitude of the charging and discharging current flowing through the capacitor C ₁₅ which is externally connected to pin 5 of AN6768K shown in FIG. 16 (Cosc). That is, when the capacitance of the capacitor C ₁₅ is increased, AN
6768K internal resistance (not shown) and the constant is long when the CR circuit constituted by the capacitor C _15, the period of the pulse voltage outputted from the 22 pin (PLSOUT) becomes long, the oscillation frequency decreases. Therefore, as the capacitor C ₁₅ externally connected to the fifth pin, for example, an E capacitor manufactured by Matsushita Electric Industrial Co., Ltd. having a temperature characteristic as shown in FIG.
CQP series film capacitors (for example, 50V
Breakdown voltage, by using a 470 pF), the capacitance of the capacitor C ₁₅ is increased with a decrease in ambient temperature, decreases as the oscillation frequency of the inverter circuit is the lamp voltage as shown in FIG. 3 increases (the arrow down in the direction of a _1), reduction of the lamp output at low temperatures is suppressed.

In this embodiment, the capacitor C ₁₅ constitutes a temperature detecting means, and the control integrated circuit and the capacitor C ₁₅
Constitute the output correction means. (Embodiment 7) The basic configuration of this embodiment shown in FIG. 17 is the same as that of Embodiment 1, and in this embodiment, a drive circuit I for turning on and off the switching elements Q ₁ and Q ₂ is used.
C (control circuit) controls the oscillation frequency of the inverter circuit and the on-duty of both switching elements Q ₁ and Q ₂ . The same components as those in FIG. 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

By the way, both switching elements Q ₁ , Q ₂
When the circuit constants are set so that the light output of the discharge lamp La becomes 100% (rated) when the on-duty of is 50%,
Since the fine adjustment cannot be performed when the optical output is 100% or less or 100% or more due to the variation of components, the on-duty of the switching elements Q ₁ and Q ₂ is designed to be unbalanced (for example, the on-duty of the switching element Q ₁ is the addition to greater than 50%, smaller than 50% on-duty of the switching element Q ₂₎ often. Further, in order to improve the power supply fluctuation characteristics, the on-duty at the time of normal lighting is set to be unbalanced, and the on-duty may be designed to be 50% when the output of the AC power supply AC is 90%. . With this design, the voltage of the AC power supply AC becomes 10
Even when the switching element Q drops from 0% to 90%, the switching element Q
By increasing the on-duty of No. ₂ , it is possible to secure a desired lamp output.

In the present embodiment, the function of the drive circuit IC to control the on-duty of both switching elements Q ₁ and Q ₂ to be 50% when the output signal of the comparator CP becomes high level. , It is possible to suppress a decrease in the lamp voltage at a low temperature. In this embodiment, AN6768K manufactured by Matsushita Electronics Corporation shown in FIG. 16 is used as the drive circuit IC.
The on-duty can be varied by varying the voltage applied to the 0th pin (Feed3).

In this embodiment, a series circuit of a temperature-sensitive resistor R ₀ and a voltage dividing resistor R ₁ whose resistance value decreases as the ambient temperature decreases constitutes a temperature detecting means, and a comparator C
The output correction means is constituted by P and the drive circuit IC. (Eighth Embodiment) The basic configuration of the present embodiment shown in FIG. 18 is the same as that of the first embodiment. In this embodiment, the temperature-sensitive resistor R ₀ and the voltage dividing resistor in the configuration of FIG. instead provided a series circuit of the R _1, as a capacitor C ₃ for resonance, the capacitor capacitance increases according to the temperature drop (e.g., manufactured by Matsushita Electric Industrial Co., Ltd. with the characteristics shown in FIG film capacitor ECQP or ECWH ) Is used. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

[0048] Thus, in the present embodiment, when the resonance characteristics b of the lamp voltage at 25 ° C. as shown in FIG. 19 is the ambient temperature is lowered, since the shift to the high frequency side (the direction of arrow A ₃ in FIG. 19), Low temperature (for example, -5 ° C.) in FIG.
If the resonance characteristic at this time is set, the lamp voltage increases while the oscillation frequency is kept constant at f, and a decrease in the lamp output (illuminance) is suppressed. Further, to suppress the capacity of the capacitor C ₃ for resonance is increased, so also increases the preheating current to the filaments of the discharge lamp La, it is possible to suppress the reduction of the lamp temperature of the discharge lamp La, a decrease of lamp voltage be able to.

In this embodiment, the resonance capacitor is used.
Sa C_ThreeConstitute temperature detecting means and output correcting means.
You. (Embodiment 9) The basic configuration of this embodiment shown in FIG.
This is almost the same as FIG. 1 of the first embodiment, and
Capacitor C_ThreeIn parallel with the switching element Q_Four 
And capacitor C₇ In that a series circuit with
You. Here, switching element Q _FourIs the output of the comparator CP
It turns on and off based on the signal, and the comparator
ON when the output signal of CP is at a high level.
Turns off when the output signal is low. The implementation
The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
Abbreviate.

In the present embodiment, however, the ambient temperature decreases, the resistance value of the temperature-sensitive resistor R ₀ decreases, and the voltage across the resistor R ₁ input to the non-inverting terminal of the comparator CP is higher than the reference voltage Vref. When also increases, the output signal of the comparator CP becomes high level, because the switching element Q ₄ is turned on, the capacitor C ₇ to the capacitor C ₃ are connected in parallel. Accordingly, when the ambient temperature of the discharge lamp La falls below a predetermined temperature, the capacitance of the capacitor constituting the LC resonance circuit increases, and the resonance characteristic of the lamp voltage of the discharge lamp La shifts to the high frequency side as in the eighth embodiment. (See FIG. 19)
However, the lamp voltage increases while maintaining the same oscillation frequency, and a decrease in the lamp output (illuminance) of the discharge lamp La is suppressed. In the present embodiment, the LC resonance circuit constitutes the temperature detecting means and the output correcting means.

(Embodiment 10) The basic configuration of the present embodiment shown in FIG.
, A heater H ₁ (heating means) for heating the ambient temperature of the discharge lamp La is provided, and on / off control of the heater H ₁ is performed based on an output signal of the comparator CP. the output signal of the comparator CP is characterized in that performing the heating by the look heater H ₁ when the high level. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. Further, it is desirable the heater H ₁ is that the shape and disposed so as not minimize block the light emitted from the discharge lamp La.

[0052] In this embodiment, than the non-inverting voltage across the reference voltage Vref of the resistor R ₁ which is input to the terminal of the comparator CP resistance of the temperature-sensitive resistor ₀ ambient temperature is lowered is reduced the discharge lamp La When also increases, the output signal of the comparator CP becomes a high level, since the start of heating by the heater H ₁ ambient temperature of the discharge lamp La rises, the lamp voltage increases. Therefore, it is possible to suppress a decrease in lamp voltage and lamp output (illuminance) at a low temperature.

In this embodiment, a series circuit of a temperature-sensitive resistor R ₀ and a voltage dividing resistor R ₁ whose resistance value decreases as the ambient temperature decreases constitutes a temperature detecting means, and a comparator C
P, constitute an output correction unit by the heater H _1. Meanwhile, as shown in FIG. 22, advance discharge lamp by disposing the cold means B ₁ consisting of the cover or the cylinder of the cold weather of cold weather around La, suppresses so a reduction in the temperature of the discharge lamp La near It may be. In the configuration of FIG. 22, it is possible that the temperature of the outer cold means B ₁ is to suppress the reduction of the lamp voltage even when dropped. Here, it is necessary to use, as the cold protection means B1, _one having a shape that does not block the light radiated from the discharge lamp La, or one formed of a material having high translucency.

[0054]

According to the first aspect of the present invention, there is provided an inverter circuit that includes a DC power supply, an LC resonance circuit and a switching element, and converts a DC voltage of the DC power supply into a high-frequency voltage by turning the switching element on and off at a high frequency. A discharge lamp to which the output of the inverter circuit is supplied through a resonance circuit, wherein the discharge lamp has a lamp voltage of 65% or less when the ambient temperature is −10 ° C. with respect to the lamp voltage when the ambient temperature is 25 ° C. Since the discharge lamp is provided with temperature detecting means for detecting the ambient temperature of the discharge lamp and output correction means for suppressing a decrease in the lamp voltage at a low temperature based on the ambient temperature detected by the temperature detecting means, The lamp voltage was 65% or less when the ambient temperature was −10 ° C. with respect to the lamp voltage when the temperature was 25 ° C. Even if there is an effect that it is possible to suppress a decrease in lamp voltage at low temperature.

According to a second aspect of the present invention, in the first aspect of the present invention, there is provided a control circuit for controlling the oscillation frequency of the inverter circuit by turning on / off the switching element by a control signal, and the output correction means comprises an output of the temperature detection means. At least one of the cycle of the control signal and the on-duty is changed so that the lamp voltage increases at a low temperature based on the above, so that the effect of increasing the lamp voltage by changing the operation of the control circuit at a low temperature is obtained. is there.

According to a third aspect of the present invention, in the first aspect of the present invention, there is provided a control circuit for controlling an oscillation frequency of an inverter circuit by turning on / off a switching element by a control signal, and a CR circuit for setting a cycle of the control signal. And the CR circuit operates such that the oscillation frequency approaches the resonance frequency of the LC resonance circuit in response to a decrease in ambient temperature.
Since the temperature detecting means and the output correcting means are formed by components having a temperature characteristic in which the R time constant changes, the cycle of the control signal changes as the ambient temperature decreases, and the oscillation frequency of the inverter circuit becomes equal to the LC frequency. Since the resonance frequency approaches the resonance frequency of the resonance circuit, it is possible to suppress a decrease in the lamp voltage at a low temperature.

According to a fourth aspect of the present invention, in the first aspect of the invention, the LC resonance circuit is formed of a component having a temperature characteristic in which a resonance frequency changes so that a lamp voltage increases in accordance with a decrease in ambient temperature. Since the temperature detecting means and the output correcting means are configured, there is an effect that as the ambient temperature decreases, the resonance frequency of the LC resonance circuit changes and the lamp voltage increases.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the output correction means includes a switching means for switching a resonance frequency of the LC resonance circuit, and the lamp is controlled at a low temperature based on the ambient temperature detected by the temperature detection means. Since the switching means is controlled to increase the voltage, the LC
There is an effect that the resonance frequency of the resonance circuit switches and the lamp voltage increases.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the output correction means includes a heating means for heating the periphery of the discharge lamp, and the heating means operates at a low temperature based on the ambient temperature detected by the temperature detecting means. Since the operation is performed, at the time of low temperature, there is an effect that the ambient temperature of the discharge lamp increases due to heating by the heating means, and the lamp voltage increases. According to a seventh aspect of the present invention, in the first aspect of the present invention, a fluorescent lamp in which a rare gas mixed with 50% or more of krypton is sealed is used as a discharge lamp, so that only argon is sealed as a rare gas. There is an effect that the lighting start voltage can be reduced as compared with the fluorescent lamp, and power can be saved.

According to a ninth aspect of the present invention, in the first aspect of the present invention, there is provided a control circuit for controlling ON / OFF of the switching element, and the output correction means operates the inverter circuit when the temperature is low based on the temperature detected by the temperature detection means. Since the operation of the control circuit is controlled so that the oscillation frequency approaches the resonance frequency of the LC resonance circuit, at a low temperature, the oscillation frequency of the inverter circuit approaches the resonance frequency of the LC resonance circuit, and the lamp voltage increases. .

According to a tenth aspect of the present invention, in the first aspect, the inverter circuit includes a pair of switching elements connected between the output terminals of the DC power supply, and an LC resonance element connected between both ends of one of the switching elements. A control circuit that alternately turns on and off both switching elements at a high frequency. The output correction means controls the on-duty of the switching elements to approach 50% when the temperature is low based on the ambient temperature detected by the temperature detection means. Since the control circuit is controlled, there is an effect that the lamp voltage can be prevented from lowering at a low temperature.

According to an eleventh aspect of the present invention, in the first aspect of the present invention, the output correction means increases the power supply voltage of the inverter circuit at a low temperature based on the ambient temperature detected by the temperature detecting means. There is an effect that the decrease in the amount can be suppressed. According to a twelfth aspect of the present invention, in the first aspect of the present invention, the output correction means is constituted by the LC resonance circuit, wherein a component having a negative temperature coefficient is used as a capacitor of the LC resonance circuit, and the capacitor is Since the temperature detecting means is configured, there is an effect that as the ambient temperature decreases, the resonance frequency of the LC resonance circuit changes and the lamp voltage increases.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a first embodiment.

FIG. 2 is a temperature characteristic diagram of a temperature-sensitive resistor used in the first embodiment.

FIG. 3 is an operation explanatory diagram of the above.

FIG. 4 is a circuit diagram showing a second embodiment.

FIG. 5 is a temperature characteristic diagram of the negative characteristic thermistor used in the first embodiment.

FIG. 6 is an explanatory diagram of a main part of a third embodiment.

FIG. 7 is an explanatory view of a main part of FIG. 6;

FIG. 8 is a circuit diagram showing a fourth embodiment.

FIG. 9 is a circuit diagram showing a fifth embodiment.

FIG. 10 is an operation explanatory view of the above.

FIG. 11 is an explanatory diagram of a main part of the above.

FIG. 12 is an explanatory diagram of a main part of the above.

FIG. 13 is a circuit diagram showing a sixth embodiment.

FIG. 14 is an operation explanatory view of the above.

FIG. 15 is an explanatory diagram of the operation of the above.

FIG. 16 is an explanatory diagram of a main part of the above.

FIG. 17 is a circuit diagram showing a seventh embodiment.

FIG. 18 is a circuit diagram showing an eighth embodiment.

FIG. 19 is a diagram illustrating the operation of the above.

FIG. 20 is a circuit diagram showing a ninth embodiment;

FIG. 21 is a circuit diagram showing a tenth embodiment.

FIG. 22 is a circuit diagram of another configuration example of the embodiment.

FIG. 23 is a temperature characteristic diagram of a fluorescent lamp.

FIG. 24 is a characteristic comparison diagram between FL40S and FL40S / 36.

[EXPLANATION OF SYMBOLS] AC AC source DB rectifier C ₁ smoothing capacitor C ₂ coupling capacitor C ₃ capacitors R ₀ temperature sensing resistor R ₁ resistor Q _1, Q ₂ switching elements La discharge lamp IC drive circuit CP comparator

Claims (12)

[Claims] 1. An inverter circuit including a DC power supply, an LC resonance circuit, and a switching element for converting a DC voltage of the DC power supply to a high frequency voltage by turning on and off a switching element at a high frequency, and an output of the inverter circuit through the LC resonance circuit. And a discharge lamp having a lamp voltage of 65% or less when the ambient temperature is −10 ° C. with respect to the lamp voltage when the ambient temperature is 25 ° C. A discharge lamp lighting device comprising: a temperature detecting means for detecting a temperature; and an output correcting means for suppressing a decrease in a lamp voltage at a low temperature based on an ambient temperature detected by the temperature detecting means. 2. A control circuit for controlling an oscillation frequency of an inverter circuit by turning on / off a switching element by a control signal, wherein the output correction means increases a lamp voltage at a low temperature based on an output of the temperature detection means. The discharge lamp lighting device according to claim 1, wherein at least one of the cycle of the control signal and the on-duty is changed. 3. A control circuit for controlling an oscillation frequency of an inverter circuit by turning on / off a switching element by a control signal, and a control circuit for setting a cycle of the control signal.
An R circuit, wherein the CR circuit is formed of a component having a temperature characteristic in which a CR time constant changes so that the oscillation frequency approaches the resonance frequency of the LC resonance circuit in accordance with a decrease in ambient temperature. 2. The discharge lamp lighting device according to claim 1, wherein said output correction means is constituted. 4. The LC resonance circuit is formed of a component having a temperature characteristic in which a resonance frequency changes so that a lamp voltage increases in accordance with a decrease in ambient temperature, and constitutes the temperature detection means and the output correction means. The discharge lamp lighting device according to claim 1, wherein: 5. The output correction means includes switching means for switching a resonance frequency of the LC resonance circuit, and controls the switching means so as to increase the lamp voltage at a low temperature based on the ambient temperature detected by the temperature detection means. The discharge lamp lighting device according to claim 1, wherein: 6. The output correction means according to claim 1, further comprising a heating means for heating the periphery of the discharge lamp, and operating the heating means at a low temperature based on the ambient temperature detected by the temperature detecting means. Discharge lamp lighting device. 7. The discharge lamp lighting device according to claim 1, wherein the discharge lamp is a fluorescent lamp filled with a rare gas mixed with 50% or more of krypton. 8. The discharge lamp lighting device according to claim 7, wherein the discharge lamp is a straight tube fluorescent lamp having a tube length of 1198 mm and a lamp rating of 36 W ± 4 W. 9. A control circuit for controlling on / off of the switching element, wherein the output correction means causes the oscillation frequency of the inverter circuit to approach the resonance frequency of the LC resonance circuit at a low temperature based on the temperature detected by the temperature detection means. The operation of the control circuit is controlled as described above.
The discharge lamp lighting device as described in the above. 10. An inverter circuit comprising: a pair of switching elements connected between output terminals of a DC power supply; an LC resonance circuit connected between both ends of one switching element; The output correction means controls the control circuit based on the ambient temperature detected by the temperature detection means so that the on-duty of the switching element approaches 50% at low temperatures. 2. The discharge lamp lighting device according to 1. 11. The discharge lamp lighting device according to claim 1, wherein the output correction means increases the power supply voltage of the inverter circuit at a low temperature based on the ambient temperature detected by the temperature detection means. 12. The output correction means is constituted by the LC resonance circuit, and as a capacitor of the LC resonance circuit,
2. The discharge lamp lighting device according to claim 1, wherein a component having a negative temperature coefficient is used, and said capacitor constitutes said temperature detecting means.