JP2002134294A - High-pressure electric discharge lamp lighting equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-pressure electric discharge lamp lighting equipment, in which discontinuation of a high-voltage electric discharge lamp cannot take place easily, when decreasing the light output of the high-pressure electric discharge lamp DL. SOLUTION: As for the time of starting of the high-pressure electric discharge lamp DL, and the time of rated lighting, switching elements Q7 and Q8 of a dimmer switch 21 are connected to contact-points b and b' side, respectively, and the high- pressure electric discharge lamp DL is made lighting on by a 1st lighting means 10. At the time of dimmer of the high-pressure electric discharge lamp DL, the switching elements Q7 and Q8 of the dimmer switch 21 that is a changing means are connected to contact-points a and a', respectively, and it is lit up by a 2nd lighting means 20. The 1st lighting means 10 is equipped with a polar reversing circuit 6, which impresses rectangle-wave shape alternate voltage to the high-pressure electric discharge lamp DL by using an electric power conversion circuit 4 as a power supply. As for the 2nd lighting means 20, the control circuit 15 carries out ON-OFF control of the switching element Q22 of the electric power conversion circuit 14 so that the high- pressure electric discharge lamp DL can be carried out direct-current lighting with the electric power set up by a dimmer device 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Hitherto, as a high-pressure discharge lamp lighting device for lighting a high-pressure discharge lamp, those having the structure shown in FIGS. 12 and 13 have been known. Here, the high pressure discharge lamp lighting device having the configuration shown in FIG. 13 shows a specific circuit of the high pressure discharge lamp lighting device having the configuration shown in FIG. 12, and is a diode bridge for full-wave rectifying an AC power supply Vs composed of a commercial power supply. A power supply circuit 2 comprising a boost chopper circuit for converting an output voltage of the rectification circuit 1 into a predetermined DC voltage and outputting the DC voltage; a control circuit 3 for controlling a switching element Q1 of the power supply circuit 2; A power conversion circuit 4 comprising a step-down chopper circuit for supplying desired power to the high-pressure discharge lamp DL using an output of the circuit 2 as a power supply; a control circuit 5 for controlling a switching element Q2 of the power conversion circuit 4; A polarity inversion circuit 6 for converting the output voltage into a low-frequency rectangular wave voltage (alternating voltage having a rectangular waveform) whose polarity is alternately inverted, and outputting the voltage;
A drive circuit 7 for controlling and driving each of the switching elements Q3 to Q6 of the polarity reversing circuit 6 and an igniter circuit 8 for generating a high-voltage pulse necessary for starting the high-pressure discharge lamp DL are provided.

The power supply circuit 2 is a well-known boost chopper circuit. A series circuit of an inductor L1 and a switching element Q1 composed of a MOSFET is connected between the DC output terminals of the rectifier circuit 1, and an anode is connected to the inductor L1 and the switching element. A series circuit of a diode D1 and a smoothing capacitor C1 connected to a connection point with Q1 forms a switching element Q1.
Are connected in parallel. Here, the switching element Q1
Is relatively high frequency (for example, several tens k
Hz to 100kHz) (on / off control)
As shown in FIG. 14 (a), energy is accumulated in the inductor L1 during the ON period of the switching element Q1, and a voltage induced across the inductor L1 and rectified by the energy during the OFF period of the switching element Q1. The configuration is such that a voltage added to the voltage between the DC output terminals of the circuit 1 is applied to the power conversion circuit 4 through the diode D1. Therefore, the voltage V1 across the smoothing capacitor C1
Is higher than the voltage between the DC output terminals of the rectifier circuit 1.

The power conversion circuit 4 is a well-known step-down chopper circuit, and includes a switching element Q
2 and an inductor L2 and a capacitor C2 in a series circuit,
Connected across the smoothing capacitor C1 of the power supply circuit 2;
A diode D2 having an anode connected to the negative electrode of the power supply circuit 2
Is connected to a connection point between the switching element Q2 and the inductor L2. Here, the switching element Q2 has a relatively high frequency (for example,
Switching (on / off control) is performed at several tens of kHz to 100 kHz) (see FIG. 14B). As is well known, the smoothing capacitor C2 is charged through the inductor L2 during the on-period of the switching element Q2, and is turned on during the on-period of the switching element Q2. It functions to discharge the energy accumulated in the inductor L2 to the smoothing capacitor C2 through a path passing through the diode D2 during the off period of the switching element Q2. Therefore, the on-off frequency and the ratio (duty) of the switching element Q2 are controlled based on the voltage detected by the voltage detection circuit 9 for detecting the voltage V2 across the smoothing capacitor C2, thereby controlling the voltage V2 across the smoothing capacitor C2.
Can be controlled. Of course, the smoothing capacitor C
The voltage V2 across the smoothing capacitor C2 also changes depending on the load state of the polarity inversion circuit 6 using the power supply 2 as a power source, and the frequency and duty for switching the switching element Q2 are adjusted according to the load state.

The polarity inversion circuits 6 are each composed of a MOSFET.
And four switching elements Q3 to Q6 are bridge-connected, and two switching elements Q3 and Q4 and two switching elements Q5 and Q6 constituting each arm of the bridge circuit are respectively connected in parallel to the smoothing capacitor C2. Thus, each arm of the bridge circuit is configured. The connection point between the two switching elements Q3 and Q4 forming one arm of the bridge circuit and the connection point between the two switching elements Q5 and Q6 forming the other arm are output from the polarity inversion circuit 6. Be at the end. That is, a circuit on the load side including the high-pressure discharge lamp DL is connected between both connection points. The switching elements Q3 to Q6 are turned on and off at a relatively low frequency (several tens Hz to several hundreds Hz) by the drive circuit 7 (see FIGS. 14C to 14F). Here, the polarity inversion circuit 6 operates such that the switching element Q3 and the switching element Q6 are turned on at the same time and the switching element Q4 and the switching element Q5 are turned on at the same time alternately.
By switching from 3 to Q6, a rectangular alternating voltage is applied to the circuit on the load side.

The igniter circuit 8 has a secondary winding n between one output terminal of the polarity inversion circuit 6 and one end of the high-pressure discharge lamp DL.
2 is inserted, and a high voltage is applied to the secondary winding n2 of the pulse transformer PT by applying the pulse voltage output from the pulse voltage generating circuit PG to the primary winding n1 of the pulse transformer PT. It is configured to generate a pulse. Pulse voltage generation circuit PG
Superimposes a high-voltage pulse on the rectangular-wave alternating voltage output from the polarity inversion circuit 6 until the high-pressure discharge lamp DL starts, and applies this voltage to the high-pressure discharge lamp DL. Note that a resonance capacitor C3 is connected in parallel to a series circuit of the secondary winding n2 of the pulse transformer PT and the high-pressure discharge lamp DL.

In the above-described conventional high pressure discharge lamp lighting device,
When the power is turned on by operating a power switch (not shown) or the like, the switching element Q1 of the power circuit 2 is turned on / off at several tens kHz to 100 kHz by the control circuit 3, and the voltage obtained by boosting the DC output voltage of the rectifier circuit 1 to a predetermined voltage is obtained. It becomes the voltage V1 across the smoothing capacitor C1. In the power conversion circuit 4, the voltage V1 across the smoothing capacitor C1 is used as a power supply, and the switching element Q2 is
The power supply circuit 2 which is turned on and off at 0 kHz to several 100 kHz
Of the output voltage (the voltage V1 across the smoothing capacitor C1) to a predetermined voltage becomes the voltage V2 (0 <V2 <V1) across the smoothing capacitor C2.

Here, since both ends of the high-pressure discharge lamp DL are open immediately after the power is turned on (the high-pressure discharge lamp DL is not lit), there is almost no power consumption in the circuit on the load side (substantially). And the voltage V2 across the smoothing capacitor C2 of the power conversion circuit 4 becomes relatively high. If the step-down chopper circuit constituting the power conversion circuit 4 is appropriately designed, the voltage of the smoothing capacitor C2 can be reduced. Voltage V at both ends
2 is a voltage close to the output voltage of the power supply circuit 2 (the voltage V1 across the smoothing capacitor C1).

On the other hand, when the power is turned on, the switching elements Q3 to Q6 of the polarity inversion circuit 6 are turned on and off at several tens Hz to several hundreds Hz, and the igniter circuit 8 is also started. Therefore, as shown in FIG. The voltage obtained by superimposing the high voltage pulse Vp generated from the igniter circuit 8 on the alternating voltage output from the polarity inversion circuit 6 becomes the voltage Vla applied to the high pressure discharge lamp DL. As described above, during the non-lighting period before the high pressure discharge lamp DL is started, the voltage V2 across the smoothing capacitor C2 is relatively high, and the igniter circuit 8
Is applied to the high-pressure discharge lamp DL, the high-pressure discharge lamp DL starts discharging (starts). When the high-pressure discharge lamp DL starts, the power conversion circuit 4 outputs a predetermined voltage and a predetermined current to the high-pressure discharge lamp D.
The high-pressure discharge lamp DL is controlled by the control circuit 5 so as to be supplied to L, and is stably lit at a low-frequency rectangular wave alternating voltage. Here, the control circuit 5 controls the frequency and the duty for switching the switching element Q2 so that the voltage detected by the voltage detection circuit 9 for detecting the potential at the connection point between the inductor L2 and the capacitor C2 becomes a predetermined voltage.

When the high pressure discharge lamp DL is turned on and the lighting period is reached, the load on the smoothing capacitor C2 increases and the voltage V2 across the smoothing capacitor C2 decreases. Also, since the high voltage pulse from the igniter circuit 8 becomes unnecessary,
The operation of the igniter circuit 8 stops. In the lighting period, the power conversion circuit 4 is controlled by the control circuit 5 so that the high-pressure discharge lamp DL is stably lit.
As shown in FIG. 14 (h), a lamp current Ila consisting of a low-frequency rectangular wave-shaped alternating current flows through the lamp.

After the high-pressure discharge lamp DL is stably turned on, the light output of the high-pressure discharge lamp DL is reduced by decreasing the amplitude of the voltage Vla applied to the high-pressure discharge lamp DL (the high-pressure discharge lamp DL is turned off). Dimmed lighting).

[0012]

However, in the high pressure discharge lamp lighting apparatus having the above-mentioned conventional configuration, when the high pressure discharge lamp DL is lit and lit, the amplitude of the voltage Vla applied to the high pressure discharge lamp DL is reduced to increase the high voltage. Since the light output of the discharge lamp DL is adjusted, as the light output of the high-pressure discharge lamp DL is reduced by decreasing the amplitude of the applied voltage Vla (the dimming is deepened), as shown in FIG. Applied voltage Vla
Becomes small, and a pause section T (see FIG. 15B) occurs when the polarity of the lamp current Ila is inverted. When such a pause T occurs, re-ignition is required, and a re-ignition voltage appears in the applied voltage Vla. When the light output of the high-pressure discharge lamp DL is further reduced (the dimming is deepened), the rest period T of the lamp current Ila becomes longer and the voltage required for re-ignition increases, but the output voltage of the polarity inversion circuit 6 increases. (That is, the output voltage of the ballast), there was a problem that the high-pressure discharge lamp DL finally extinguished without being re-ignited.
In short, if the ratio of the light output at the time of dimming light to the light output at the time of rated lighting is used as the dimming ratio and the lower limit of the dimming ratio is used to represent the width of the dimming range, the dimming range cannot be widened. There was a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-pressure discharge lamp lighting device in which the high-pressure discharge lamp does not easily extinguish during dimming operation of the high-pressure discharge lamp DL. .

[0014]

According to a first aspect of the present invention, there is provided a first lighting means for lighting a high-pressure discharge lamp with a rectangular alternating voltage, and the high-pressure discharge lamp with a DC voltage. A high-pressure discharge lamp is lit by the first lighting means during rated lighting of the high-pressure discharge lamp, and the high-pressure discharge lamp is turned on by the second lighting means during dimming lighting of the high-pressure discharge lamp. And switching means for switching the lamp to be lit by the polarity of the lamp current flowing through the high-pressure discharge lamp when the high-pressure discharge lamp is lit by a DC voltage during dimming lighting of the high-pressure discharge lamp. Does not reverse, the lamp current flowing through the high-pressure discharge lamp does not have an idle period as in the case where the high-pressure discharge lamp is dimmed and lit by a rectangular wave alternating voltage, and deep dimming is performed. Not unstable discharge also, since extinction is unlikely to occur in the high pressure discharge lamp, allows deeper dimming.

According to a second aspect of the present invention, there is provided a first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and the high-pressure discharge lamp. In a dimming range where the voltage applied to the lamp does not extinguish with a rectangular wave alternating voltage, the high pressure discharge lamp is turned on by the first lighting means, and the applied voltage to the high pressure discharge lamp extinguishes with a rectangular wave alternating voltage. Switching means for switching the high-pressure discharge lamp to be lit by the second lighting means within a dimming range that causes the high-pressure discharge lamp to be turned on by a rectangular wave alternating voltage. Since the high-pressure discharge lamp is lit by a DC voltage within a dimming range that causes the light to go out,
The lamp current flowing through the high-pressure discharge lamp does not have an idle period, so that the discharge does not become unstable and the high-pressure discharge lamp does not easily go out, so that deeper dimming is possible, and During the dimming operation of the high-pressure discharge lamp, a rectangular wave-like alternating voltage is applied to the high-pressure discharge lamp within a dimming range in which the applied voltage to the high-pressure discharge lamp does not extinguish at a rectangular wave-like alternating voltage. As compared with a case where the high-pressure discharge lamp is lit by a DC voltage over the entire dimming range, it is possible to prevent the deterioration of one of the two electrodes in the arc tube of the high-pressure discharge lamp from being biased, and the high-pressure discharge lamp can be prevented. The life of the electric lamp can be extended.

According to a third aspect of the present invention, there is provided a first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and the high-pressure discharge lamp. When the power consumption of the high-pressure discharge lamp is larger than a predetermined value, the high-pressure discharge lamp is turned on by the first lighting means. When the power consumption of the high-pressure discharge lamp is equal to or less than the predetermined value, the high-pressure discharge lamp is turned on by the second lighting means. Switching means for switching the high-pressure discharge lamp when the power consumption of the high-pressure discharge lamp is equal to or less than the predetermined value. By setting the value to an electric power that does not cause the high-pressure discharge lamp to extinguish, the discharge does not become unstable during dimming lighting, and the high-pressure discharge lamp hardly extinguishes. Therefore, deeper dimming becomes possible, and when the power consumption of the high-pressure discharge lamp is larger than a predetermined value during dimming lighting of the high-pressure discharge lamp, a rectangular wave alternating voltage is applied to the high-pressure discharge lamp. Therefore, it is possible to prevent the deterioration of the high-pressure discharge lamp from being biased toward one of the two electrodes in the arc tube of the high-pressure discharge lamp as compared with a case where the high-pressure discharge lamp is lit by a DC voltage over the entire dimming range. The life of the high pressure discharge lamp can be extended.

According to a fourth aspect of the present invention, there is provided a first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and the high-pressure discharge lamp. Voltage detecting means for detecting a voltage applied to the high-pressure discharge lamp, and when the voltage detected by the voltage detecting means reaches a predetermined value or more in a state where the high-pressure discharge lamp is lit by the first lighting means, Switching means for switching to be lit by the lighting means, wherein the high-pressure discharge lamp is lit by a DC voltage when a voltage detected by the voltage detecting means becomes a predetermined value or more. Therefore, by setting the predetermined value to a voltage that does not cause the high-pressure discharge lamp to extinguish, the discharge does not become unstable at the time of dimming lighting,
Since it is difficult for the high pressure discharge lamp to extinguish, deeper dimming becomes possible.When the voltage detected by the voltage detecting means is smaller than the predetermined value at the time of dimming lighting of the high pressure discharge lamp, the high pressure discharge is performed. Since the rectangular wave alternating voltage is applied to the electric lamp, it is biased toward one of the two electrodes in the arc tube of the high-pressure discharge lamp as compared with a case where the high-pressure discharge lamp is turned on by a DC voltage over the entire dimming range. Deterioration can be prevented, and the life of the high-pressure discharge lamp can be extended.

According to a fifth aspect of the present invention, in the first to fourth aspects, the first lighting means includes a DC power supply and a power conversion means for converting an output voltage of the DC power supply to a predetermined voltage and outputting the predetermined voltage. And a polarity inversion means for applying a rectangular wave alternating voltage to the high-pressure discharge lamp using an output of the power conversion means as a power supply, wherein the second lighting means is provided in the first lighting means from the polarity inversion means. Since the operation of the polarity inversion means is changed so that a DC voltage is applied to the high-pressure discharge lamp, the number of circuit elements is reduced as compared with a case where the second lighting means and the first lighting means are separately provided. Can be reduced,
The size and cost can be reduced.

According to a sixth aspect of the present invention, in the fifth aspect of the invention, the polarity inverting means has a configuration in which four switching elements are bridge-connected, and the two switching elements constituting one arm of a bridge circuit. The high-pressure discharge lamp is inserted between a connection point of the first arm and a connection point of two switching elements forming the other arm, and the second lighting means includes the four switching elements in the polarity inversion means. The DC voltage is applied to the high-pressure discharge lamp by maintaining one of the two sets of switching elements located at the diagonal of the bridge in the ON state and maintaining the other in the OFF state. By controlling the switching element, the voltage applied to the high-pressure discharge lamp can be shifted from the rectangular-wave alternating voltage to the DC voltage.

According to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, when the light output of the high pressure discharge lamp is reduced, the second lighting means reduces the power consumption of the high pressure discharge lamp to a target. Since the supply power to the high-pressure discharge lamp is gradually reduced until the power is reached, it is possible to avoid a sudden change in the state of the high-pressure discharge lamp when shifting from rated lighting to dimming lighting, and to achieve more stable adjustment. Can light.

According to an eighth aspect of the present invention, in the first to seventh aspects of the present invention, the second lighting means sets a target power consumption of the high pressure discharge lamp when increasing the light output of the high pressure discharge lamp. Since the power is immediately increased, the time required for the light output of the high-pressure discharge lamp to reach a desired light output can be reduced.

According to a ninth aspect of the present invention, in accordance with the first to eighth aspects of the present invention, there is provided a dimmer for setting the light output of the high-pressure discharge lamp, and the second lighting means sets the dimmer. Since the light output of the high-pressure discharge lamp is adjusted according to the following conditions, the light output of the high-pressure discharge lamp is adjusted to a desired light output during dimming operation by setting a desired light output in the dimmer in advance. can do.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, there is provided a dimming switch for instructing a start of adjustment of the light output of the high-pressure discharge lamp, and the second lighting means is controlled by the dimming switch. Since the light output of the high-pressure discharge lamp is adjusted according to the setting of the dimmer when the instruction to start the light output adjustment is issued, the start of the dimming lighting can be instructed by the dimming switch.

[0024]

(Embodiment 1) As shown in FIG. 2, a high pressure discharge lamp lighting device according to the present embodiment includes a first lighting means 10 for lighting a high pressure discharge lamp DL with a rectangular wave alternating voltage. A second lighting means 20 for lighting the high-pressure discharge lamp DL with a DC voltage; and a dimming switch 21 for switching between the first lighting means 10 and the second lighting means 20. Here, the dimming switch 21 is connected to the high-pressure discharge lamp D
During the rated lighting of L, the high pressure discharge lamp DL
The high-pressure discharge lamp D
A switching means for switching so that L is lit by the second lighting means 20 is provided.

Hereinafter, a specific circuit of the high pressure discharge lamp lighting device of the present embodiment will be described with reference to FIG.

The first lighting means 10 has a configuration similar to that of a conventional high pressure discharge lamp lighting device. As shown in FIG. 1, a rectifier comprising a diode bridge for full-wave rectifying an AC power supply Vs composed of a commercial power supply. A power supply circuit 2 including a booster chopper circuit for converting an output voltage of the rectifier circuit 1 into a predetermined DC voltage and outputting the DC voltage; a control circuit 3 for controlling a switching element Q1 of the power supply circuit 2; A power conversion circuit 4 composed of a step-down chopper circuit for supplying desired power to the high-pressure discharge lamp DL using an output as a power supply, a control circuit 5 for controlling a switching element Q2 of the power conversion circuit 4, and an output voltage of the power conversion circuit 4 A polarity inverting circuit 6 that converts and outputs a low-frequency rectangular wave voltage (alternating voltage having a rectangular wave shape) whose polarity is alternately inverted, and controls the switching elements Q3 to Q6 of the polarity inverting circuit 6 A drive circuit 7 for driving, and a igniter circuit 8 for generating a high voltage pulse required to start the high-pressure discharge lamp DL. Note that the same components as those in the conventional configuration are denoted by the same reference numerals.

The power supply circuit 2 is a step-up chopper circuit in which a series circuit of an inductor L1 and a switching element Q1 composed of a MOSFET is connected between the DC output terminals of the rectifier circuit 1, and an anode is connected to the inductor L1 and the switching element Q1. The series circuit of the diode D1 and the smoothing capacitor C1 connected to the connection point is connected in parallel to the switching element Q1. Here, the switching element Q1 is controlled by the control circuit 3 at a relatively high frequency (for example, several tens kHz).
(On / off control) at the switching element Q1 during the on period of the switching element Q1.
And the added voltage of the voltage induced across the inductor L1 and the voltage between the DC output terminals of the rectifier circuit 1 during the off-period of the switching element Q1 by the energy is supplied to the power conversion circuit 4 through the diode D1. It is configured to apply. Therefore, the smoothing capacitor C
1 is higher than the voltage between the DC output terminals of the rectifier circuit 1.

The power conversion circuit 4 is a step-down chopper circuit in which a series circuit of a switching element Q2 composed of a MOSFET, an inductor L2 and a capacitor C2 is connected between both ends of a smoothing capacitor C1 of the power supply circuit 2. The cathode of a diode D2 whose anode is connected to the negative electrode of the switching element Q2 is connected to the connection point between the switching element Q2 and the inductor L2. Here, switching element Q2
Is switched (on / off controlled) at a relatively high frequency (for example, several tens of kHz to 100 kHz) by the control circuit 5, and charges the smoothing capacitor C2 through the inductor L2 during the on period of the switching element Q2, thereby turning on the switching element Q2. The energy accumulated in the inductor L2 is discharged to the smoothing capacitor C2 through a path passing through the diode D2 during the off period of the switching element Q2. Therefore, the voltage V2 across the smoothing capacitor C2 can be controlled by controlling the on / off frequency and the ratio (duty) of the switching element Q2. Of course, depending on the load state of the polarity inversion circuit 6 using the smoothing capacitor C2 as a power source, the smoothing capacitor C
2, the voltage V2 changes, and the frequency and duty for switching the switching element Q2 are adjusted according to the load state. Here, the first lighting means 10 includes a voltage detection circuit 9 for detecting the voltage V2 across the smoothing capacitor C2 as a lamp voltage of the high-pressure discharge lamp DL,
The control circuit 5 controls the switching element Q2 based on the voltage detected by the voltage detection circuit 9.

The polarity inversion circuits 6 are each composed of a MOSFET.
And four switching elements Q3 to Q6 are bridge-connected, and two switching elements Q3 and Q4 and two switching elements Q5 and Q6 constituting each arm of the bridge circuit are respectively connected in parallel to the smoothing capacitor C2. Thus, each arm of the bridge circuit is configured. The connection point between the two switching elements Q3 and Q4 forming one arm of the bridge circuit and the connection point between the two switching elements Q5 and Q6 forming the other arm are output from the polarity inversion circuit 6. Be at the end. That is, a circuit on the load side including the high-pressure discharge lamp DL is connected between both connection points. The switching elements Q3 to Q6 are turned on and off by the drive circuit 7 at a relatively low frequency (several tens Hz to several hundreds Hz). Here, the polarity inversion circuit 6 includes a switching element Q
3 and Q6 are simultaneously turned on and the switching element Q
The switching elements Q3 to Q6 are switched so that a period in which the switching elements Q4 and Q5 are simultaneously turned on is alternately applied, thereby applying a rectangular wave alternating voltage to the circuit on the load side.

The igniter circuit 8 has a secondary winding n between one output terminal of the polarity inversion circuit 6 and one end of the high-pressure discharge lamp DL.
2 is inserted, and a high voltage is applied to the secondary winding n2 of the pulse transformer PT by applying the pulse voltage output from the pulse voltage generating circuit PG to the primary winding n1 of the pulse transformer PT. It is configured to generate a pulse. Pulse voltage generation circuit PG
Superimposes a high-voltage pulse on the rectangular-wave alternating voltage output from the polarity inversion circuit 6 until the high-pressure discharge lamp DL starts, and applies this voltage to the high-pressure discharge lamp DL. Note that a resonance capacitor C3 is connected in parallel to a series circuit of the secondary winding n2 of the pulse transformer PT and the high-pressure discharge lamp DL.

As shown in FIG. 1, the second lighting means 20 includes a rectifier circuit 11 composed of a diode bridge for full-wave rectifying an AC power supply Vs composed of a commercial power supply and a predetermined output voltage of the rectifier circuit 11. A power supply circuit 12 comprising a boost chopper circuit for converting the output to a DC voltage and outputting the DC voltage;
A control circuit 13 for controlling the switching element Q12 of
A power conversion circuit 14 including a step-down chopper circuit for supplying desired power to the high-pressure discharge lamp DL using an output of the power supply circuit 12 as a power supply; and a switching element Q22 of the power conversion circuit 14
And a control circuit 15 for controlling

The power supply circuit 12 is a step-up chopper circuit in which a series circuit of an inductor L12 and a switching element Q12 made of a MOSFET is connected between the DC output terminals of the rectifier circuit 11, and an anode is connected to the inductor L12 and the switching element Q12. D connected to the connection point
12 and a series circuit of a smoothing capacitor C13 are connected in parallel to the switching element Q12. Here, the switching element Q12 is switched (on / off control) at a relatively high frequency (for example, several tens of kHz to 100 kHz) by the control circuit 13, and energy is accumulated in the inductor L12 during the on-period of the switching element Q12. The addition voltage of the voltage induced across the inductor L12 and the voltage between the DC output terminals of the rectifier circuit 11 during the off period of the switching element Q12 is applied to a diode D12.
Through the power conversion circuit 14. Therefore, the voltage V3 across the smoothing capacitor C13
Is higher than the voltage between the DC output terminals of the rectifier circuit 11.

The power conversion circuit 14 is a step-down chopper circuit, and includes a switching element Q22 composed of a MOSFET.
A series circuit of an inductor L22 and a capacitor C14 is connected between both ends of a smoothing capacitor C13 of the power supply circuit 12, and a cathode of a diode D22 having an anode connected to a negative electrode of the power supply circuit 12 is connected to a switching element Q22 and an inductor L22. Connected to a point. here,
The switching element Q22 is switched (on / off controlled) at a relatively high frequency (for example, several tens kHz to 100 kHz) by the control circuit 15, and the switching element Q22 is switched.
During the ON period of the switching element Q22, the smoothing capacitor C14 is charged through the inductor L22, and the energy accumulated in the inductor L22 during the ON period of the switching element Q22 is released to the smoothing capacitor C14 via a path passing through the diode D22 during the OFF period of the switching element Q22. To work.
Therefore, the voltage V4 across the smoothing capacitor C14 can be controlled by controlling the on / off frequency and the ratio (duty) of the switching element Q22. Of course, depending on the load condition, the smoothing capacitor C1
The voltage V4 across the terminal 4 changes, and the frequency and duty for switching the switching element Q22 are adjusted according to the load state. Here, the second lighting means 20 is
The control circuit 15 includes a voltage detection circuit 19 that detects a voltage between both ends of the smoothing capacitor C14 as a lamp voltage of the high-pressure discharge lamp DL. The control circuit 15 lights the high-pressure discharge lamp DL with a light output preset by the dimmer 16. As described above, the switching element Q22 is controlled based on the voltage detected by the voltage detection circuit 19 (the voltage V4 across the smoothing capacitor C14).

As shown in FIG. 1, the dimming switch 21 includes a pair of interlocking switching elements Q7 and Q8. One of the first lighting means 10 and the second lighting means 20 is provided. The switching elements Q7 and Q8 are switched in conjunction with each other so that only the high-pressure discharge lamp DL is connected. Here, the switching elements Q7 and Q8 are connected to the high-pressure discharge lamp DL. The switching elements Q7 and Q8 are connected to the contacts b and b 'at the time of rated lighting and the switching elements at the time of dimming lighting. Q7, Q8
Are connected to the contacts a and a ′. The switching element Q7 has a contact a that is connected to the inductor L22 of the power conversion circuit 14.
The contact b is connected to one end of the secondary winding n2 of the pulse transformer PT. The switching element Q8 has a contact a ′ connected to a connection point between the capacitor 14 of the power conversion circuit 14 and the diode D22, and a contact b ′ connected to a connection point between the switching elements Q5 and Q6 of the polarity inversion circuit 6. I have. Here, the dimming switch 21 may be constituted by a manual switch having an operation unit operated manually, or may be constituted by an electromagnetic switch or the like.

The operation of the high pressure discharge lamp lighting device according to the present embodiment will be described below.

When the high-pressure discharge lamp DL is started and at the time of rated lighting, the switching elements Q7 and Q8 of the dimmer switch 21 are connected to the contacts b and b ', respectively.
Is turned on by the lighting means 10. Here, the first
Since the configuration and operation of the lighting means 10 are the same as those of the conventional high pressure discharge lamp lighting apparatus, the operations at the time of starting and at the time of rated lighting are omitted.

On the other hand, when the high-pressure discharge lamp DL is dimmed, the switching elements Q7 and Q8 of the dimming switch 21 are connected to the contacts a and a ', respectively, and the high-pressure discharge lamp DL is set in advance by the dimmer 15. Lighting is performed by the second lighting means 20 at the target power.

In short, when the dimming switch 21 is switched in a state where the high-pressure discharge lamp DL is rated at the applied voltage Vla consisting of a rectangular alternating voltage as shown in the left half of FIG. The DL is dimmed and lit with an applied voltage Vla consisting of a DC voltage as shown in the right half of FIG. Therefore, the lamp current Ila becomes a rectangular wave alternating current as shown in the left half of FIG. 3B when the high-pressure discharge lamp DL is rated, and when the dimming switch 21 is switched, the lamp current Ila becomes the right half of FIG. As shown in FIG.

Thus, in the high pressure discharge lamp lighting device of the present embodiment, during dimming lighting, the high pressure discharge lamp DL is lit by a DC voltage using the power conversion circuit 14 of the second lighting means 20 as a DC power supply. Therefore, the polarity of the applied voltage Vla and the lamp current Ila to the high-pressure discharge lamp DL is not inverted, there is no need to re-ignite, and there is no pause in the lamp current Ila. It is less likely to be unstable, and it is less likely to be extinguished than in the case where dimming lighting is performed by a rectangular wave alternating voltage, so that deeper dimming becomes possible.

(Embodiment 2) The basic configuration of the high pressure discharge lamp lighting device according to the present embodiment is substantially the same as the conventional configuration, and as shown in FIG. Dimming switch 2 for instructing the start of dimming to switch
1 and a control circuit such that when the start of dimming lighting is instructed by the dimming switch 21, the light output of the high-pressure discharge lamp DL becomes a light output corresponding to a preset target power (target lamp power). 5 and a dimmer 16 for giving an instruction to the drive circuit 7. Note that the same components as those in the conventional configuration are denoted by the same reference numerals, and description thereof is omitted.

When the start of dimming lighting is instructed by the dimmer switch 21, the dimmer 16 outputs a signal for giving a set value of the target power to the control circuit 5 and inverts the polarity to the drive circuit 7. Outputs a signal to stop operation. Here, when a signal giving a set value of the target power is input from the dimmer 16, the control circuit 5 switches the switching element Q2 so that the output voltage of the power conversion circuit 4 becomes a voltage value corresponding to the set value. Control. When a signal for stopping the polarity inversion operation is input from the dimmer 16 to the drive circuit 7, the four switching elements Q3
Of the two switching elements Q at the diagonal positions
One set of the set of switching elements Q3 and Q6 and the set of switching elements Q4 and Q5 is maintained in the on state, and the other set is maintained in the off state. Therefore, the connection point of the two switching elements Q3 and Q4 forming one arm of the bridge circuit and the two switching elements Q3 forming the other arm
A DC voltage is applied to a circuit on the load side including the discharge lamp DL connected between the connection points of the terminals 5 and Q6.

Hereinafter, the operation of the discharge lamp lighting device according to the present embodiment will be described.

The operation of the high pressure discharge lamp DL at the time of starting and at the time of rated lighting is the same as the operation of the conventional high pressure discharge lamp lighting device, and the switching elements Q3 to Q6 of the polarity inversion circuit 6 are used.
Are turned on and off at a relatively low frequency (several tens Hz to several hundreds Hz) by the drive circuit 7 (see the left half of FIGS. 5A to 5D), and a period during which the switching elements Q3 and Q6 are simultaneously turned on. The switching elements Q3 and Q5 are turned on at the same time so that the switching elements Q3 and Q5 are alternately turned on.
Since Q6 is switched, a rectangular wave alternating voltage is applied to the high-pressure discharge lamp DL as the applied voltage Vla as shown in the left half of FIG.

On the other hand, when the high-pressure discharge lamp DL is lit, the switching elements Q4 and Q5 are kept on and the switching elements Q3 and Q6 are kept off. A DC voltage is applied as shown in the right half of e). Here, this DC voltage is obtained by controlling the switching element Q2 by the control circuit 5 so that the high-pressure discharge lamp DL is turned on with the power set by the dimmer 16 in advance.

In short, when the dimming switch 21 is switched in a state where the high-pressure discharge lamp DL is rated at the applied voltage Vla composed of a rectangular alternating voltage as shown in the left half of FIG. The DL is dimmed and lit with an applied voltage Vla composed of a DC voltage as shown in the right half of FIG. Therefore, the lamp current Ila becomes a rectangular wave alternating current as shown in the left half of FIG. 5 (f) when the high pressure discharge lamp DL is rated, and when the dimming switch 21 is switched, the lamp current Ila becomes the right half of FIG. 5 (f). As shown in FIG.

In the high pressure discharge lamp lighting device of this embodiment, the high pressure discharge lamp DL is lit by a rectangular wave alternating voltage at the time of starting and rated lighting, and the high pressure discharge lamp DL is lit by a DC voltage at the time of dimming lighting. Therefore, the polarity of the applied voltage Vla and the lamp current Ila to the high-pressure discharge lamp DL is not inverted, there is no need to perform re-ignition, and there is no pause in the lamp current Ila. Discharge of the electric light DL is less likely to be unstable, and it is less likely that the light will be extinguished than when dimming and lighting is performed by using a rectangular wave alternating voltage, thereby enabling deeper dimming.

In the present embodiment, the rectifier circuit 1,
The power supply circuit 2, the power conversion circuit 4, the polarity inversion circuit 6, the control circuits 3 and 5, the drive circuit 7, and the voltage detection circuit 9 constitute first lighting means for lighting the high-pressure discharge lamp DL with a rectangular alternating voltage. Then, by appropriately changing the operation of the control circuit 5 and the drive circuit 7 in the first lighting means, a second lighting means for lighting the high-pressure discharge lamp DL with a DC voltage is constituted. The light output of the high-pressure discharge lamp DL is adjusted according to the setting of the optical device 16. Further, the high-pressure discharge lamp DL is turned on by the first lighting means by the dimming switch 21 at the time of rated lighting of the high-pressure discharge lamp DL.
A switching means for switching the high-pressure discharge lamp DL so as to be lit by the second lighting means when the dimming lighting of L is performed. The rectifier circuit 1 and the power supply circuit 2 constitute a DC power supply, the power conversion circuit 4 constitutes a power conversion means, and the polarity inversion circuit 6 constitutes a polarity inversion means. Therefore, in the present embodiment, there is no need to separately provide the second lighting means 20 as described in the first embodiment, and the control circuit 5 controls the output voltage of the power conversion circuit 4 and the driving circuit 7 controls the switching element. Since both the rated lighting and the dimming lighting can be handled by the control of Q3 to Q6, the number of circuit elements can be reduced as compared with the first embodiment, and the size and cost of the entire device can be reduced.

The dimming switch 21 may be constituted by a manual switch having an operation section operated manually.
Or you may comprise with an electromagnetic switch etc.

(Embodiment 3) The basic structure of the high pressure discharge lamp lighting device according to the present embodiment is substantially the same as that of the embodiment 2;
As shown in (1), a lamp power detection circuit 26 for detecting the lamp power when the high-pressure discharge lamp DL is turned on is added, and the operation of the drive circuit 7 is appropriately changed based on the output of the lamp power detection circuit 26 as described later. There is a feature in the point. Note that the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof is omitted.

The dimmer 16 in the present embodiment outputs only a signal of the target lamp power set value at the time of dimming lighting when dimming lighting is instructed by the dimming switch 21. The lamp power detection circuit 26 detects the current detected by the current sensor 25 that detects the current flowing through the high-pressure discharge lamp DL, the potential at the connection point between the inductor L2 and the capacitor C2 (that is, the output voltage of the power conversion circuit 4). And outputs a signal for stopping the polarity inversion operation to the drive circuit 7 only when the detected power is equal to or less than a predetermined value. When a signal for stopping the polarity inversion operation is input from the lamp power detection circuit 26, the drive circuit 7 switches two diagonally located switching elements Q3 and Q3 of the four bridge-connected switching elements Q3 to Q6. The switching elements Q3 to Q6 are controlled such that one set of the set of Q6 and the set of switching elements Q4 and Q5 is maintained in the on state, and the other set is maintained in the off state. Therefore, a connection point between the two switching elements Q3 and Q4 forming one arm of the bridge circuit;
The two switching elements Q5 and
A DC voltage is applied to a circuit on the load side including the discharge lamp DL connected to the connection point of Q6.

Hereinafter, the operation of the high pressure discharge lamp lighting device of the present embodiment will be described.

The operation of the high pressure discharge lamp DL at the time of starting and at the time of rated lighting is the same as that of the conventional configuration.
As shown in the left part of FIG. 7B, a rectangular alternating voltage is applied to L.

On the other hand, even during the dimming operation of the high pressure discharge lamp DL, the detected power Wla by the lamp power detection circuit 26 is detected.
(See FIG. 7A) is a threshold value Wth set in advance.
7B, a rectangular wave-like alternating voltage is applied to the high-pressure discharge lamp DL as shown in the middle of FIG. 7B (however, in this case, the amplitude of the applied voltage Vla is larger than that at the time of rated lighting). Smaller). On the other hand, when the dimming of the high-pressure discharge lamp DL is deepened and the detected power Wla by the lamp power detection circuit 26 becomes equal to or less than the threshold value Wth, the lamp power detection circuit 26 outputs a signal for stopping the polarity inversion operation to the drive circuit. 7 and the switching elements Q3 to Q6 are controlled by the drive circuit 7 so that the switching elements Q4 and Q5 are kept on and the switching elements Q3 and Q6 are kept off. Is applied with a DC voltage as shown in the right part of FIG. Here, this DC voltage is obtained by controlling the switching element Q2 by the control circuit 5 so that the high-pressure discharge lamp DL is turned on with the power set by the dimmer 16 in advance.

In short, when the detected power Wla changes as shown in FIG. 7A, the detected power Wla
When the detected power Wla is equal to or less than the threshold value Wth, the high-pressure discharge lamp DL is lit at an applied voltage Vla formed of a DC voltage when the detected power Wla is equal to or less than the threshold value Wth. . Therefore, as shown in FIG. 7C, the lamp current Ila becomes a rectangular wave alternating current while the detected power Wla by the lamp power detection circuit 26 is larger than the threshold value Wth, and the detected power Wla is equal to or smaller than the threshold value Wth. The interval is a direct current.

In the high pressure discharge lamp lighting device of the present embodiment, the detected power Wla by the lamp power detection circuit 26 for detecting the power consumption of the high pressure discharge lamp DL is equal to the threshold value Wth.
During the lighting period, the high-pressure discharge lamp DL is lit by the rectangular alternating voltage regardless of the rated lighting and the dimming lighting, and the detected power Wla by the lamp power detection circuit 26 during the dimming lighting is equal to or less than the threshold Wth. Is turned on by a DC voltage. By setting the threshold value Wth to a value at which the high-pressure discharge lamp DL does not extinguish,
When deepening the dimming, the voltage Vl applied to the high-pressure discharge lamp DL
a and the lamp current Ila are not inverted, there is no need for re-ignition, and there is no pause in the lamp current Ila. Therefore, the discharge of the high-pressure discharge lamp DL is unlikely to be unstable, and the rectangular alternating current As compared with the case where dimming lighting is performed by a voltage, darkening hardly occurs, and deeper dimming becomes possible. Further, in the present embodiment, even when the dimming operation is performed, when the detected power Wla by the lamp power detection circuit 26 is larger than the threshold value Wth, the high-pressure discharge lamp DL is lit by the rectangular wave alternating voltage. As compared with the case where the high-pressure discharge lamp DL is lit by the DC voltage over the entire light control range, it is possible to suppress the deterioration of the high-pressure discharge lamp DL from being biased to one of the two electrodes in the arc tube.

By the way, in this embodiment, as in the second embodiment, the rectifier circuit 1, the power supply circuit 2, the power conversion circuit 4, the polarity inversion circuit 6, the control circuits 3, 5, the drive circuit 7, and the voltage detection circuit 9 Constitutes a first lighting means for lighting the high-pressure discharge lamp DL with a rectangular wave alternating voltage, and appropriately changes the operations of the control circuit 5 and the drive circuit 7 in the first lighting means to thereby provide a high-pressure discharge lamp with a DC voltage. DL
Is constituted, and the second lighting means adjusts the light output of the high pressure discharge lamp DL according to the setting of the dimmer 16. When the power consumption of the high-pressure discharge lamp DL is larger than a predetermined value (the threshold value Wth), the dimming switch 21 and the lamp power detection circuit 26 provide the high-pressure discharge lamp DL.
Are turned on by the first lighting means, and constitute switching means for switching the high pressure discharge lamp DL to be lighted by the second lighting means when the power consumption of the high pressure discharge lamp DL is equal to or less than the predetermined value. Therefore, in the present embodiment, there is no need to separately provide the second lighting means 20 as described in the first embodiment, and the control circuit 5 controls the output voltage of the power conversion circuit 4 and the driving circuit 7 controls the switching element. Q3 ~
Since both rated lighting and dimming lighting can be handled by the control of Q6, the number of circuit elements can be reduced as compared with the first embodiment,
The size and cost of the entire device can be reduced. The dimming switch 21 may be constituted by a manual switch having an operation unit operated manually, or may be constituted by an electromagnetic switch or the like.

The ratio of the detected power Wla of the lamp power detection circuit 26 at the time of dimming lighting to the detected power Wla of the lamp power detection circuit 26 at the time of rated lighting is defined as a power ratio, and is used for mercury lamps, high-pressure sodium lamps, metal halide lamps, and the like. Table 1 below shows the measurement results of the lower limit of the power ratio when the extinction occurs when various high-pressure discharge lamps are dimmed and lit by a high-voltage discharge lamp lighting device having a conventional configuration using a rectangular alternating voltage.

[0058]

[Table 1]

From Table 1, it can be seen that the maximum value of the power ratio at which the various high-pressure discharge lamps that have been measured extinguishes is 30%, so that the threshold value Wth should have some margin.
For example, a lamp power of approximately 50% of the lamp power at the time of rated lighting may be set.

(Embodiment 4) The basic structure of the high pressure discharge lamp lighting device of the present embodiment is substantially the same as that of Embodiment 3, and FIG.
As shown in the figure, the output signal of the voltage detection circuit 9 is
Is also configured to be input. Here, when the detected voltage becomes equal to or higher than the predetermined value Vth, the voltage detection circuit 9 outputs a signal for stopping the polarity inversion operation of the polarity inversion circuit 6 to the drive circuit 7, and the drive circuit 7 outputs the polarity inversion signal from the voltage detection circuit 9. When a signal for stopping the polarity inversion operation of the circuit 6 is input, the four switching elements Q3 to Q3
Two switching elements Q at diagonal positions of Q6
The switching elements Q3 to Q6 are driven such that one set of the set of Q3 and Q6 and the set of switching elements Q4 and Q5 is kept on and the other set is kept off. Therefore, the connection point between the two switching elements Q3 and Q4 forming one arm of the bridge circuit and the two switching elements Q5 and Q6 forming the other arm
A DC voltage is applied to a circuit on the load side including the discharge lamp DL connected between the connection point and the connection point.

The lamp power detection circuit 26 stores the detected power Wla when the detected power Wla becomes equal to or more than a predetermined value Wth ′ (see FIG. 9B described later) as the lamp power. When the lamp power exceeds the previously stored lamp power, a signal for starting the polarity inversion operation is output to the drive circuit 7. On the other hand, when a signal for starting the polarity inversion operation is input from the lamp power detection circuit 26 to the drive circuit 7, the switching elements Q3 to Q6 are driven by the drive circuit 7 to have a relatively low frequency (several tens to several hundreds Hz). The switching is performed such that a period in which the switching elements Q3 and Q6 are simultaneously turned on and a period in which the switching elements Q4 and Q5 are simultaneously turned on are alternately generated. Therefore, a rectangular wave alternating voltage is applied to the load-side circuit of the polarity inversion circuit 6.

Hereinafter, the operation of the high pressure discharge lamp lighting device of the present embodiment will be described.

The operation of the high pressure discharge lamp DL at the time of starting and at the time of rated lighting is the same as that of the conventional configuration.
A rectangular wave-like alternating voltage is applied to L.

On the other hand, when the dimming operation of the high-pressure discharge lamp DL is started by operating the dimming switch 21, the preset value of the target power preset in the dimmer 16 is output. Control is performed so that the output voltage of the power conversion circuit 4 becomes a predetermined value corresponding to the target power. As the detected power Wla by the lamp power detection circuit 26 gradually decreases with time as shown in FIG. 9B (that is, the dimming progresses and the dimming deepens).
As shown in FIG. 9D, the quiescent period T of the lamp current Ila
And the high-pressure discharge lamp D shown in FIG.
The re-ignition voltage at the voltage Vla applied to L rises.
At this time, when the voltage detected by the voltage detection circuit 9 becomes equal to or more than a predetermined threshold value Vth, a signal for stopping the polarity inversion operation is output from the voltage detection circuit 9 to the drive circuit 7, and the drive circuit 7
As a result, the switching elements Q4 and Q5 are held in the ON state, and the switching elements Q3 and Q6 are held in the OFF state.
The DC voltage is as shown in FIG. Here, in the lamp power detection circuit 26, the detected power Wla when the voltage detected by the voltage detection circuit 9 is detected to be equal to or higher than the threshold Vth is stored as a threshold (lamp power) Wth ′, and the detected power Wla Is greater than or equal to the previously stored threshold value Wth ', the driving circuit 7 outputs a signal to start the polarity inversion operation. When a signal for starting the polarity inversion operation is input from the lamp power detection circuit 26, the drive circuit 7 switches the switching elements Q3 to Q6 to a relatively low frequency (several tens Hz to
On and off at several hundred Hz), and the switching elements Q3, Q
6 and the switching elements Q4, Q
Since the switching elements Q3 to Q6 are switched so that the periods during which the LEDs 5 are simultaneously turned on alternately occur, a rectangular wave alternating voltage as shown in FIG. 9C is applied to the high-pressure discharge lamp DL as the applied voltage Vla. Applied.

However, in the high pressure discharge lamp lighting device of this embodiment, when the re-ignition voltage of the high pressure discharge lamp DL becomes equal to or higher than the predetermined value Vth at the time of dimming lighting, the lighting (rectangular wave lighting) using the rectangular wave alternating voltage is performed. ) To lighting by DC voltage (DC lighting), the dimming ratio changes, and the detected power Wla by the lamp power detection circuit 26 exceeds the threshold value Wth ′ at the time of shifting from rectangular wave lighting to DC lighting. In this case, there is a shift from DC lighting to rectangular wave lighting. In short, the high-pressure discharge lamp DL is lit in a rectangular wave in the dimming range where the high-pressure discharge lamp DL does not extinguish. Therefore, deeper dimming can be performed as compared with the conventional configuration, and the high-pressure discharge lamp DL can be compared with a case where DC lighting is performed over the entire dimming range.
It is possible to suppress the occurrence of the deterioration in one of the electrodes in the arc tube.

In this embodiment, as in the second embodiment, the rectifier circuit 1, the power supply circuit 2, the power conversion circuit 4, the polarity inversion circuit 6, the control circuits 3, 5, the drive circuit 7, and the voltage detection circuit 9 are also provided. Constitutes a first lighting means for lighting the high-pressure discharge lamp DL with a rectangular wave alternating voltage, and appropriately changes the operations of the control circuit 5 and the drive circuit 7 in the first lighting means to thereby provide a high-pressure discharge lamp with a DC voltage. DL
Is constituted, and the second lighting means adjusts the light output of the high pressure discharge lamp DL according to the setting of the dimmer 16. In addition, the dimming switch 21 and the lamp power detection circuit 26 allow the high pressure discharge lamp DL to be turned on by the first lighting means when the voltage detected by the voltage detection circuit 9 becomes higher than the predetermined value Vth. A switching means for switching the electric light DL to be lit by the second lighting means is provided. Therefore, in the present embodiment, there is no need to separately provide the second lighting means 20 as described in the first embodiment, and the control circuit 5 controls the output voltage of the power conversion circuit 4 and the driving circuit 7 controls the switching element. Q
Since both rated lighting and dimming lighting can be handled by the control of 3 to Q6, the number of circuit elements can be reduced as compared with the first embodiment, and the size and cost of the entire device can be reduced. The dimming switch 21 may be constituted by a manual switch having an operation unit operated manually, or may be constituted by an electromagnetic switch or the like.

In this embodiment, the voltage detected by the voltage detection circuit 9 is compared with the threshold value Vth in order to detect a rise in the re-ignition voltage as a precursor to the disappearance of the high-pressure discharge lamp DL. The means for detecting the sign of the disappearance of the DL is not limited to the means for comparing the detection voltage of the voltage detection circuit 9 with the threshold value Vth, but may be any means capable of detecting the sign of the disappearance of the high-pressure discharge lamp DL.

(Embodiment 5) The basic configuration of a high pressure discharge lamp lighting device according to the present embodiment is substantially the same as that of Embodiment 4, and FIG.
As shown in FIG. 5, between the dimmer 16 and the control circuit 5, the control circuit 5 changes the set value linearly with the passage of time to a set value corresponding to the target power set by the dimmer 16. It is characterized by the addition of a linear circuit 17 for supplying the power to the motor. Note that the same components as those in the fourth embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the high pressure discharge lamp lighting device of the present embodiment, when the start of dimming is instructed by the dimming switch 21, the set value of the target power is output from the dimmer 16, and the control circuit 5 17, the lamp power of the high-pressure discharge lamp DL (that is, the power Wla detected by the lamp power detection circuit 26 and the power consumption of the high-pressure discharge lamp DL) gradually decreases over time (FIG. 11).
(Refer to (a)), the switching element Q2 of the power conversion circuit 4 is controlled as described above, and when the increase of the light output is instructed by the dimming switch 21, the switching of the power conversion circuit 4 is performed so that the lamp power immediately reaches the target value. The element Q2 is controlled.

Hereinafter, the operation of the high pressure discharge lamp lighting device of the present embodiment will be described.

The operation of the high pressure discharge lamp DL at the time of starting and at the time of rated lighting is the same as that of the conventional configuration.
A rectangular wave-like alternating voltage is applied to L.

On the other hand, when the dimming operation of the high-pressure discharge lamp DL is started by operating the dimming switch 21, the preset value of the target power set in the dimmer 16 is output. Control is performed so that the output voltage of the power conversion circuit 4 becomes a predetermined value corresponding to the target power. The power Wla detected by the lamp power detection circuit 26 gradually decreases with time as shown in FIG. 11A, and the re-ignition voltage at the voltage Vla applied to the high-pressure discharge lamp DL increases. At this time, when the voltage detected by the voltage detection circuit 9 becomes equal to or higher than a predetermined threshold value Vth (see FIG. 11B), a signal for stopping the polarity inversion operation is output from the voltage detection circuit 9 to the drive circuit 7, and the drive circuit 7 As a result, the switching elements Q4 and Q5 are held in the on state, and the switching elements Q3 and Q6 are held in the off state, so that the voltage Vla applied to the high-pressure discharge lamp DL becomes a DC voltage as shown in FIG. . The lamp power detection circuit 26
Stores the detected power Wla when the voltage detected by the voltage detection circuit 9 is equal to or higher than the threshold Vth as a threshold (lamp power) Wth.

In the high pressure discharge lamp lighting device according to the present embodiment, however, it is possible to avoid a sudden change in the lamp state of the high pressure discharge lamp DL particularly at the time of transition to dimming lighting in which discharge tends to be unstable (ie, during dimming). Light control can be performed more stably. Note that the lamp power may gradually change to the target value as time elapses as in the case of dimming, but it is desirable to immediately obtain the desired illuminance before performing dimming lighting. Because it is often
By increasing the lamp power immediately at the time of brightening, in which the extinction does not easily occur as in the present embodiment, the time required to obtain the desired illuminance can be reduced.

[0074]

According to the first aspect of the present invention, a first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and Switching means for switching the high-pressure discharge lamp so that the high-pressure discharge lamp is lit by the first lighting means during rated lighting of the discharge lamp and the second lighting means is lit when the high-pressure discharge lamp is dimmed. When the high-pressure discharge lamp is dimmed, the high-pressure discharge lamp is lit by a DC voltage and the polarity of the lamp current flowing through the high-pressure discharge lamp does not reverse. Therefore, the high-pressure discharge lamp is adjusted by a rectangular wave alternating voltage. There is no pause period in the lamp current flowing through the high-pressure discharge lamp as in the case of light lighting, and the discharge does not become unstable even when deep dimming is performed, and the high-pressure discharge lamp does not go out. Since Rinikui, there is an effect that the deeper the dimming is possible.

According to a second aspect of the present invention, there is provided a first lighting means for lighting a high-pressure discharge lamp with a rectangular alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and the high-pressure discharge lamp. In a dimming range where the voltage applied to the lamp does not extinguish with a rectangular wave alternating voltage, the high pressure discharge lamp is turned on by the first lighting means, and the applied voltage to the high pressure discharge lamp extinguishes with a rectangular wave alternating voltage. Switching means for switching the high-pressure discharge lamp to be lit by the second lighting means within a dimming range that causes the high-pressure discharge lamp to extinguish at a rectangular wave alternating voltage. Since the high-pressure discharge lamp is lit by the DC voltage within the dimming range, the discharge becomes unstable because the lamp current flowing through the high-pressure discharge lamp does not have an idle period. Therefore, the high-pressure discharge lamp is less likely to extinguish, so that there is an effect that deeper dimming can be performed, and the voltage applied to the high-pressure discharge lamp during the dimming lighting of the high-pressure discharge lamp has a rectangular waveform. In the dimming range where the light does not extinguish at the alternating voltage, a rectangular wave alternating voltage is applied to the high-pressure discharge lamp, so that the high-voltage discharge lamp is illuminated with a DC voltage over the entire dimming range. Deterioration can be prevented from occurring in one of the two electrodes in the arc tube of the discharge lamp, and the life of the high-pressure discharge lamp can be extended.

According to a third aspect of the present invention, there is provided a first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and the high-pressure discharge lamp. When the power consumption of the high-pressure discharge lamp is larger than a predetermined value, the high-pressure discharge lamp is turned on by the first lighting means. When the power consumption of the high-pressure discharge lamp is equal to or less than the predetermined value, the high-pressure discharge lamp is turned on by the second lighting means. Switching means for switching the high-pressure discharge lamp to a predetermined voltage when the power consumption of the high-pressure discharge lamp is equal to or less than the predetermined value. By setting the power so that the electric lamp does not extinguish, the discharge does not become unstable at the time of dimming lighting, and the high-pressure discharge lamp hardly extinguishes. This has the effect of enabling dimming, and when the power consumption of the high-pressure discharge lamp is greater than a predetermined value during dimming lighting of the high-pressure discharge lamp, a rectangular wave alternating voltage is applied to the high-pressure discharge lamp. Therefore, compared to a case where the high-pressure discharge lamp is turned on by a DC voltage over the entire dimming range, it is possible to prevent the deterioration from being biased to one of the two electrodes in the arc tube of the high-pressure discharge lamp, There is an effect that the life of the high pressure discharge lamp can be extended.

According to a fourth aspect of the present invention, the first lighting means for lighting the high-pressure discharge lamp with a rectangular wave alternating voltage, the second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and the high-pressure discharge lamp Voltage detecting means for detecting a voltage applied to the high-pressure discharge lamp, and when the voltage detected by the voltage detecting means reaches a predetermined value or more in a state where the high-pressure discharge lamp is lit by the first lighting means, Switching means for switching so as to be lit by the lighting means.When the voltage detected by the voltage detecting means becomes a predetermined value or more, the high-pressure discharge lamp is lit by a DC voltage. By setting the predetermined value to a voltage that does not cause the high-pressure discharge lamp to extinguish, discharge does not become unstable during dimming lighting, and the high-pressure discharge lamp does not extinguish. Therefore, when the voltage detected by the voltage detecting means is smaller than the predetermined value at the time of dimming lighting of the high-pressure discharge lamp, a rectangular wave is applied to the high-pressure discharge lamp. Since the alternating voltage is applied, deterioration occurs in one of the two electrodes in the arc tube of the high-pressure discharge lamp as compared with a case where the high-pressure discharge lamp is lit by a DC voltage over the entire dimming range. And the life of the high-pressure discharge lamp can be extended.

According to a fifth aspect of the present invention, in the first to fourth aspects, the first lighting means includes a DC power supply and a power conversion means for converting an output voltage of the DC power supply into a predetermined voltage and outputting the predetermined voltage. And a polarity inversion means for applying a rectangular wave alternating voltage to the high-pressure discharge lamp using an output of the power conversion means as a power supply, wherein the second lighting means is provided in the first lighting means from the polarity inversion means. Since the operation of the polarity inversion means is changed so that a DC voltage is applied to the high-pressure discharge lamp, the number of circuit elements is reduced as compared with a case where the second lighting means and the first lighting means are separately provided. Can be reduced,
There is an effect that downsizing and cost reduction can be achieved.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the polarity inverting means has a configuration in which four switching elements are bridge-connected, and two switching elements forming one arm of a bridge circuit. The high-pressure discharge lamp is inserted between a connection point of the first arm and a connection point of two switching elements forming the other arm, and the second lighting means includes the four switching elements in the polarity inversion means. The DC voltage is applied to the high-pressure discharge lamp by maintaining one of the two sets of switching elements located at the diagonal of the bridge in the ON state and maintaining the other in the OFF state. By controlling the switching element, there is an effect that the voltage applied to the high-pressure discharge lamp can be shifted from the rectangular alternating voltage to the DC voltage.

According to a seventh aspect of the present invention, in the first to sixth aspects of the present invention, when the light output of the high-pressure discharge lamp is reduced, the second lighting means reduces the power consumption of the high-pressure discharge lamp to a target. Since the supply power to the high-pressure discharge lamp is gradually reduced until the power is reached, it is possible to avoid a sudden change in the state of the high-pressure discharge lamp when shifting from rated lighting to dimming lighting, and to achieve more stable adjustment. There is an effect that light can be emitted.

According to an eighth aspect of the present invention, in the first to seventh aspects of the present invention, the second lighting means sets the target power consumption of the high pressure discharge lamp when increasing the light output of the high pressure discharge lamp. Since the power is immediately increased, the time required for the light output of the high-pressure discharge lamp to reach a desired light output can be shortened.

According to a ninth aspect of the present invention, in accordance with the first to eighth aspects of the present invention, there is provided a dimmer for setting the light output of the high-pressure discharge lamp, and the second lighting means is provided for setting the dimmer. Since the light output of the high-pressure discharge lamp is adjusted according to the following conditions, the light output of the high-pressure discharge lamp is adjusted to a desired light output during dimming operation by setting a desired light output in the dimmer in advance. There is an effect that can be.

According to a tenth aspect of the present invention, in the ninth aspect of the present invention, there is provided a dimming switch for instructing a start of the adjustment of the light output of the high-pressure discharge lamp, and the second lighting means is controlled by the dimming switch. Since the light output of the high-pressure discharge lamp is adjusted according to the setting of the dimmer when there is an instruction to start the light output adjustment, it is possible to instruct the start of dimming lighting by the dimming switch. effective.

[Brief description of the drawings]

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

FIG. 2 is a conceptual diagram of the same.

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

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

FIG. 5 is an operation explanatory view of the above.

FIG. 6 is a circuit diagram showing a third embodiment.

FIG. 7 is an operation explanatory diagram of the above.

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

FIG. 9 is an operation explanatory view of the above.

FIG. 10 is a circuit diagram showing a fifth embodiment.

FIG. 11 is an operation explanatory diagram of the above.

FIG. 12 is a circuit block diagram showing a conventional example.

FIG. 13 is a circuit diagram of the same.

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

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

[Explanation of symbols]

 Reference Signs List 4 power conversion circuit 6 polarity inversion circuit 10 first lighting means 20 second lighting means 14 power conversion circuit 15 control circuit 16 dimmer 21 dimming switch a, a 'contact b, b' contact Q7, Q8 switching element Q22 Switching element DL High pressure discharge lamp

Claims (10)

[Claims] A first lighting means for lighting the high-pressure discharge lamp with a rectangular wave alternating voltage; a second lighting means for lighting the high-pressure discharge lamp with a DC voltage; Switching means for switching the high-pressure discharge lamp so that the high-pressure discharge lamp is lit by the first lighting means and is lit by the second lighting means when the high-pressure discharge lamp is dimmed. Lighting device. 2. A first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and a voltage applied to the high-pressure discharge lamp. In a dimming range in which the extinction does not occur at the rectangular wave alternating voltage, the dimming is performed such that the high-pressure discharge lamp is lit by the first lighting means and the applied voltage to the high-pressure discharge lamp causes extinction at the rectangular wave alternating voltage. Switching means for switching the high-pressure discharge lamp to be turned on by the second lighting means within the range. 3. A first lighting means for lighting the high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and a power consumption of the high-pressure discharge lamp is predetermined. When the value is larger than the predetermined value, the high pressure discharge lamp is switched on by the first lighting means, and when the power consumption of the high pressure discharge lamp is equal to or less than the predetermined value, the high pressure discharge lamp is switched on by the second lighting means. Means for lighting a high-pressure discharge lamp. 4. A first lighting means for lighting a high-pressure discharge lamp with a rectangular wave alternating voltage, a second lighting means for lighting the high-pressure discharge lamp with a DC voltage, and a voltage applied to the high-pressure discharge lamp. A voltage detecting means for detecting, and the high pressure discharge lamp is turned on by the second lighting means when the voltage detected by the voltage detecting means becomes a predetermined value or more while the high pressure discharge lamp is turned on by the first lighting means. A high-pressure discharge lamp lighting device, comprising: switching means for performing switching. 5. The first lighting means comprises: a DC power supply; a power conversion means for converting an output voltage of the DC power supply to a predetermined voltage for output; Polarity inverting means for applying a wave-like alternating voltage, wherein the second lighting means is configured to invert the polarity in the first lighting means so that a DC voltage is applied from the polarity inversion means to the high-pressure discharge lamp. The high pressure discharge lamp lighting device according to any one of claims 1 to 4, wherein the operation of the means is changed. 6. The polarity inverting means has a configuration in which four switching elements are bridge-connected, and a connection point of two switching elements forming one arm of a bridge circuit and two nodes forming the other arm. The high pressure discharge lamp is inserted between the connection points of the switching elements, and the second lighting means includes two of the four switching elements in the polarity reversing means, each of which is located at a diagonal of a bridge. The high pressure discharge lamp lighting device according to claim 5, wherein a DC voltage is applied to the high pressure discharge lamp by maintaining one of the sets of switching elements in an on state and the other in an off state. 7. When the light output of the high-pressure discharge lamp is reduced, the second lighting means gradually reduces the power supplied to the high-pressure discharge lamp until the power consumption of the high-pressure discharge lamp reaches the target power. The high pressure discharge lamp lighting device according to any one of claims 1 to 6, wherein the lighting device is operated. 8. The apparatus according to claim 1, wherein said second lighting means immediately increases the power consumption of said high-pressure discharge lamp to a target power when increasing the light output of said high-pressure discharge lamp. Item 8. A high pressure discharge lamp lighting device according to any one of Items 7. 9. A light controller for setting a light output of the high-pressure discharge lamp, wherein the second lighting means adjusts a light output of the high-pressure discharge lamp according to a setting of the light controller. The high pressure discharge lamp lighting device according to any one of claims 1 to 8, wherein 10. A light control switch for instructing a start of light output adjustment of the high pressure discharge lamp, wherein the second lighting means is adapted to start light output adjustment by the light control switch. 10. The high pressure discharge lamp lighting device according to claim 9, wherein the light output of the high pressure discharge lamp is adjusted according to the setting of the dimmer.