JP2012134032A - Discharge lamp lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device which can prevent or suppress wear of an electrode of a discharge lamp and occurrence of a flicker when the discharge lamp is lighted up by a low power lighting mode.SOLUTION: A discharge lamp lighting device comprises a discharge lamp and a power supply device which supplies AC power to the discharge lamp. The power supply device has a function of lighting up the discharge lamp by switching between a rated power lighting mode for supplying rated power to the discharge lamp and a low power lighting mode for supplying lower power than the rated power to the discharge lamp. In the low power lighting mode, the power supply device continuously supplies basic AC power of a predetermined power value to the discharge lamp while periodically supplying superimposed power which is superimposed on the basic AC power, and controls supply timing, a power value, or supply time of the superimposed power in accordance with a measured value of lighting voltage of the discharge lamp.

Description

  The present invention relates to a discharge lamp lighting device that can be suitably used as a light source of a projector device.

In the projection type projector device, it is required to project a uniform and sufficient color rendering image onto a rectangular screen. For this reason, as a light source, mercury vapor pressure during lighting is required. For example, a short arc type discharge lamp having a pressure of 150 atm or higher is employed.
Thus, recently, a projector device having a dimming function capable of adjusting the screen brightness according to the brightness of the use environment and the type of image to be projected has been developed, and the discharge used in such a projector device is developed. As the lamp lighting device, the discharge lamp is switched between a rated power lighting mode for supplying rated power to the discharge lamp and a low power lighting mode for supplying power lower than the rated power to the discharge lamp, for example, 80% of the rated power. There is known a device including a power feeding device that lights up (see Patent Document 1).

However, in such a discharge lamp lighting device, there is a problem in that the tip of each electrode is worn and flicker occurs in the low power lighting mode.
The reason why the tip of the electrode is worn and flickered in the discharge lamp in the low power lighting mode is considered as follows.

While the discharge lamp is lit, the electrode material evaporates from the electrode by generating heat at a high temperature, but the electrode material evaporated by the halogen cycle is deposited on the surface of the electrode. When the discharge lamp is lit in the rated power lighting mode, the evaporation of the electrode material from the electrode and the deposition of the evaporated electrode material on the electrode are in an equilibrium state, so that electrode wear is suppressed.
However, when the discharge lamp is turned on in the low power lighting mode, the amount of the electrode material evaporated around the electrode is significantly reduced, so that the electrode material is not sufficiently deposited on the electrode. As the electrode material evaporates, the tip of the electrode is worn and flicker occurs.

Japanese Patent No. 4274053

  The present invention has been made on the basis of the above circumstances, and its purpose is to discharge a discharge lamp when the discharge lamp is lit in a low-power lighting mode that supplies AC power lower than the rated power of the discharge lamp. It is an object of the present invention to provide a discharge lamp lighting device capable of preventing or suppressing lamp electrode wear and flicker.

The discharge lamp lighting device of the present invention is a discharge lamp lighting device comprising a discharge lamp and a power feeding device for supplying AC power to the discharge lamp.
The power supply device has a function of switching on a rated power lighting mode for supplying rated power to the discharge lamp and a low power lighting mode for supplying power lower than rated power to the discharge lamp to light the discharge lamp. In the low power lighting mode, the basic AC power of a predetermined power value is continuously supplied to the discharge lamp, and the superimposed power superimposed on the basic AC power is periodically supplied, and According to the measurement value of the lighting voltage of the discharge lamp, the supply time of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power is controlled.

In the discharge lamp lighting device according to the present invention, when the measured value of the lighting voltage of the discharge lamp is higher than a predetermined reference value in the low power lighting mode, the power supply device is lower than the predetermined reference value. It is preferable that the supply timing of the superimposed power is controlled so that the superimposed power is supplied to the discharge lamp at a time interval shorter than the time.
Discharge lamp lighting device.
In the low power lighting mode, when the measured value of the lighting voltage of the discharge lamp is higher than a predetermined reference value, the power feeding device has a higher power value than when the measured value is lower than the predetermined reference value. It is preferable that the power value of the superimposed power is controlled so that the superimposed power is supplied to the discharge lamp.
In the low power lighting mode, when the measured value of the discharge lamp lighting voltage is higher than a predetermined reference value, the power supply apparatus performs the superimposition in a longer time than when the measured value is lower than the predetermined reference value. The supply time of the superimposed power is preferably controlled so that power is supplied to the discharge lamp.
Further, even if the measured value of the lighting voltage of the discharge lamp is measured when the superimposed power is not supplied, or measured when the superimposed power is supplied Good.

  According to the discharge lamp lighting device of the present invention, in the low power lighting mode in which the power feeding device supplies power lower than the rated power to the discharge lamp, the superposition superimposed on the basic AC power of a predetermined power value for the discharge lamp. The power is periodically supplied, and the superimposing power supply timing, superimposing power power value or superimposing power supply time is controlled according to the measured value of the lighting voltage of the discharge lamp. The amount of evaporated electrode material present increases, thereby facilitating the deposition of evaporated electrode material on the electrodes of the discharge lamp, so that the wear and flickering of the discharge lamp electrodes can be prevented or suppressed. .

It is sectional drawing for description which shows the structure in an example of the discharge lamp used for the discharge lamp lighting device of this invention. It is explanatory drawing which shows an example of the current waveform of the alternating current power supplied to a discharge lamp. It is a figure which shows the change of the electric power value supplied to a discharge lamp with the change of the lighting voltage of a discharge lamp in the low electric power lighting mode in an example of an electric power feeder. It is a figure which shows the change of the electric power value supplied to a discharge lamp with the change of the lighting voltage of a discharge lamp in the low electric power lighting mode in the other example of an electric power feeder. It is a figure which shows the change of the electric power value supplied to a discharge lamp with the change of the lighting voltage of a discharge lamp in the low electric power lighting mode in the further another example of an electric power feeder.

Hereinafter, embodiments of the discharge lamp lighting device of the present invention will be described.
The discharge lamp lighting device of the present invention is built in, for example, a projector device having a dimming function, and includes a discharge lamp and a power feeding device that supplies AC power to the discharge lamp.

FIG. 1 is an explanatory cross-sectional view showing the configuration of an example of a discharge lamp used in the discharge lamp lighting device of the present invention.
The arc tube 11 of the discharge lamp 10 has a light emitting part 12 having a substantially elliptical outer shape that forms a discharge space S therein, and a tube axis integrally connected to both ends of the light emitting part 12. A rod-shaped sealing portion 13 extending outward is provided, and a pair of electrodes 14 and 15 made of tungsten are disposed in the light emitting portion 12 of the arc tube 11 so as to face each other. More specifically, each of the pair of electrodes 14 and 15 is continuous with rod-shaped shaft portions 14b and 15b extending along the tube axis direction of the arc tube 11 and the tips of the shaft portions 14b and 15b. The substantially spherical heads 14a and 15a formed with protrusions p1 at the tips, and the coil portions 14c and 15c wound around the rear ends of the heads 14a and 15a and the tips of the shafts 14b and 15b. The head portions 14a and 15a are arranged so as to face each other, and the base end portions of the shaft portions 14b and 15b are held by being embedded in the sealing portions 13 respectively. Yes.
Metal foils 16 and 17 made of molybdenum are hermetically embedded in each of the sealing portions 13 in the arc tube 11, and one end of each of the metal foils 16 and 17 is in each of the pair of electrodes 14 and 15. The base ends of the shaft portions 14b and 15b are welded and electrically connected. On the other hand, the other ends of the metal foils 16 and 17 are external leads 18 projecting outward from the outer end of the sealing portion 13. 19 is welded and electrically connected.

The arc tube 11 is made of quartz glass, and mercury, a rare gas, and halogen are sealed in the light emitting portion 12 of the arc tube 11, for example.
The mercury sealed in the light emitting unit 12 is for obtaining a radiated light having a necessary visible light wavelength, for example, a wavelength of 360 to 780 nm, and in order to ensure a high mercury vapor pressure of, for example, 150 atm or higher when lighting, The enclosed amount is set to 0.15 mg / mm ³ or more. By increasing the enclosed amount of mercury, a high mercury vapor pressure of 200 atmospheres or more, or 300 atmospheres or more can be obtained at the time of lighting. Can be realized.
The rare gas sealed in the light emitting unit 12 is for improving the lighting startability, and the sealed pressure is, for example, 10 to 26 kPa as a static pressure. Moreover, argon gas can be used suitably as a noble gas.
The halogen encapsulated in the light emitting unit 12 forms a halogen cycle in the light emitting unit 12, thereby suppressing tungsten as an electrode material from adhering to the inner wall of the light emitting unit 12. Encapsulated in the form of a compound with mercury or other metals. The amount of halogen enclosed is, for example, 1 × 10 ⁻⁶ to 1 × 10 ⁻² μmol / mm ³ . As halogen, iodine, bromine, chlorine and the like can be used.
In addition, a metal halide can be encapsulated in the light emitting unit 12 as another discharge medium.

An example of the specific specification of such a discharge lamp 10 is as follows. The maximum outer diameter of the light emitting part 12 in the arc tube 11 is 10 mm, the distance between the electrodes is 1.0 mm, and the internal volume of the light emitting part 12 in the arc tube 11 is 60 mm ³ , rated voltage is 75V, and rated power is 200W.
Further, in the discharge lamp 10, the mercury vapor pressure in the light emitting portion 12 in the arc tube 11 is, for example, 150 atm or more during lighting, and the projector apparatus incorporating the discharge lamp lighting device is small in size as a whole. However, since a high amount of light is required, the thermal conditions in the light emitting portion 12 of the arc tube 11 of the discharge lamp 10 are extremely severe. For example, the lamp wall load value of the lamp is 0.8 to 3.0 W / mm ² , more specifically 2.0 W / mm ² .
By having such a high mercury vapor pressure and tube wall load value, it is possible to obtain radiant light with good color rendering when used as a light source of a projector apparatus.

In the discharge lamp lighting device of the present invention, the power feeding device switches between a rated power lighting mode for supplying rated power to the discharge lamp 10 and a low power lighting mode for supplying power lower than the rated power to the discharge lamp 10. Superimposed power superposed on the basic AC power, having a function of lighting the discharge lamp 10 and continuously supplying the basic AC power of a predetermined power value to the discharge lamp 10 in the low power lighting mode. Is supplied periodically.
Here, the power value of the basic AC power in the low power lighting mode is not particularly limited as long as it is lower than the value of the rated power, but is usually selected in the range of 40 to 80% of the rated power.

The current waveform of the AC power supplied to the discharge lamp 10 is preferably in a form in which low frequency components having a frequency lower than the fundamental frequency component are periodically inserted into the fundamental frequency component.
An example of a current waveform of AC power supplied to the discharge lamp 10 is shown in FIG. In this figure, the vertical axis represents the current value of the electric power supplied to the discharge lamp 10, and the horizontal axis represents the lighting time of the discharge lamp 10. In this current waveform, a low frequency component F2 having a frequency lower than the fundamental frequency component is periodically included in the fundamental frequency component F1.
The frequency of the fundamental frequency component F1 is selected from a range of 60 to 1000 Hz, for example. On the other hand, the frequency of the low frequency component F2 is lower than the frequency of the fundamental frequency component F1, and is selected from a range of, for example, 5 to 200 Hz.
In addition, the low frequency component may be a half cycle length, and the insertion interval of the low frequency component (the time from when a certain low frequency component is inserted until the next low frequency component is inserted) The interval) is preferably 120 seconds or less, more preferably 0.01 to 120 seconds.
The specific frequencies of the fundamental frequency component F1 and the low frequency component F2, the insertion interval of the low frequency component F2, and the amplitude of the low frequency component F2 depend on the design of the discharge lamp 10 used, particularly the thermal design of the electrodes 14 and 15. In consideration of the above relationship and the value of power in each lighting mode, etc. are selected as appropriate.

Further, the fundamental frequency component of the basic alternating current power in the low power lighting mode is preferably higher than the fundamental frequency component of the alternating current in the rated power lighting mode, for example, the fundamental frequency component of the alternating current in the rated power lighting mode. It is preferably 1.1 to 10 times the frequency.
The low frequency component of the superimposed power in the low power lighting mode is preferably lower than the low frequency component of the rated power lighting mode, for example, 10 to 95% of the frequency of the low frequency component of the rated power. Is preferred.
As a specific example, when the rated power of the discharge lamp 10 is 230 W and the basic AC power in the low power lighting mode is 75% of the rated power, the fundamental frequency component of the AC current in the rated voltage lighting mode is 370 Hz. The low frequency component is 46.25 Hz, the basic frequency component of the basic AC power in the low power lighting mode is 518 Hz, and the low frequency component of the superimposed power is 37 Hz.

  Then, the supply time of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power is controlled by the power feeding device in accordance with the measured value of the lighting voltage of the discharge lamp 10. Here, even if the measured value of the lighting voltage of the discharge lamp 10 is a value measured when the superimposed power is supplied (hereinafter referred to as “when power is superimposed”), the superimposed power is not supplied. It may be a value measured at times (hereinafter referred to as “when power is not superimposed”).

FIG. 3 is a diagram illustrating a change in the power value supplied to the discharge lamp together with a change in the lighting voltage of the discharge lamp in the low power lighting mode in the example of the power supply apparatus.
The power supply apparatus of this example controls the supply timing of superimposed power according to the measured value of the lighting voltage of the discharge lamp 10 in the low power lighting mode. More specifically, when the measured value of the lighting voltage of the discharge lamp 10 is lower than a predetermined reference value V ₀ , the discharge lamp 10 is supplied with the basic AC power of the power value P ₁ and the power value P _{The two} superimposed powers are periodically superimposed on the basic AC power at a predetermined supply time T and a predetermined time interval t ₁ . When the measured value of the lighting voltage of the discharge lamp 10 becomes higher than the reference value V ₀ , the superimposed power of the power value P _{2 on} the discharge lamp 10 is a predetermined time interval shorter than the predetermined supply time T and the time interval t _1. At t ₂ , the basic AC power is periodically superimposed and supplied, that is, the time interval of the superimposed power is changed from t ₁ to a shorter t ₂ . When the measured value of the lighting voltage of the discharge lamp 10 becomes lower than the predetermined reference value V ₀ again, the superimposed power of the power value P ₂ is applied to the discharge lamp 10 at the predetermined supply time T and the predetermined time interval t ₁ . The basic AC power is periodically superimposed and supplied, that is, the time interval of the superimposed power is changed from t ₂ to t ₁ .

In the above, the reference value V ₀ of the lighting voltage is the specification of the discharge lamp 10, the power value P ₁ of the basic AC power supplied to the discharge lamp 10 in the low power lighting mode, the power value P _{2 of} the superimposed power, and the superimposed power The time is set appropriately in consideration of the supply time T, the time intervals t ₁ and t _{2 of} the superimposed power, and the like. For example, it is preferable to increase the setting of the reference value V ₀ of the lighting voltage as the setting of the time intervals t ₁ and t ₂ of the superimposed power is increased.
Further, the time interval t ₁ of the superimposed power when the lighting voltage is lower than the reference value V ₀ depends on the basic AC power P ₁ , the voltage value P _{2 of} the superimposed power, the supply time T of the superimposed power, etc., for example, 1 It is preferably set in a range of ˜60 minutes.
Further, the time interval t ₂ of the superimposed power when the lighting voltage is higher than the reference value V _{0 only} needs to be shorter than the time interval t _1. The power value P ₁ of the basic AC power, the power value P _{2 of} the superimposed power, and the superimposed power Is appropriately set in consideration of the supply time T, the reference value V ₀ of the lighting voltage, and the like. For example, it is preferable to shorten the setting of the superimposed power time interval t _{2 as} the setting value of the lighting voltage reference value V ₀ is increased.
The superimposing power supply time T depends on the power value P ₁ of the basic AC power, the power value P _{2 of} the superimposing power, the time interval t ₁ of the superimposing power, etc., but is selected in the range of 1 to 10 minutes, for example. It is preferable.
Further, the power value P ₂ of the superimposed power depends on the power value P ₁ of the basic AC power, the supply time T of the superimposed power, the time interval t ₁ of the superimposed power, and the like, for example, a range of 65 to 120% of the rated power. It is preferable that
More specific examples are as follows.
Superimposed power 173 W is supplied to the supplied power 230 W in the rated power lighting mode and the supplied power 138 W in the low power lighting mode, and the parameters of the supplied power and the superimposed power in the low power lighting mode are set according to the lamp voltage in any mode.
When the lamp voltage is lower than the reference value of the lighting voltage, the time interval of the superimposed power is lengthened, and when the lamp voltage is higher than the reference value, the time interval of the superimposed power is shortened. For example,
When the lamp voltage is less than the reference value 100V, the time interval of the superimposed power is 15 minutes,
When the lamp voltage is equal to or higher than the reference value 100V, the time interval of the superimposed power is set to 5 minutes.
In both cases, the supply time of the superimposed power is 2 minutes.
Alternatively, the supply time of the superimposed power is shortened when the lamp voltage is lower than the reference value of the lighting voltage, and the supply time of the superimposed power is lengthened when the lamp voltage is higher than the reference value. For example,
When the lamp voltage is less than the reference value 100V, the superimposing power supply time is 2 minutes,
When the lamp voltage is equal to or higher than the reference value 100V, the supply time of the superimposed power is set to 4 minutes.
In any case, the time interval of the superimposed power is 15 minutes.

In such a power supply device, a specific example of the set value of the supplied power in the low power lighting mode is given. When the rated power of the discharge lamp 10 is 230 W, the power value P ₁ of the basic AC power is 138 W. (60% of rated power), superimposed power value P ₂ is 35 W, superimposed power supply time is 2 minutes, superimposed power time interval t ₁ is 15 minutes and time interval t ₂ is 5 minutes, when power is superimposed The reference value V _{0 of the} lighting voltage to be measured is 80V.

FIG. 4 is a diagram illustrating a change in the power value supplied to the discharge lamp together with a change in the lighting voltage of the discharge lamp in the low power lighting mode in another example of the power feeding apparatus.
The power supply device of this example controls the power value of the superimposed power in accordance with the measured value of the lighting voltage of the discharge lamp 10 in the low power lighting mode. More specifically, when the measured value of the lighting voltage of the discharge lamp 10 is lower than a predetermined reference value V ₀ , the discharge lamp 10 is supplied with the basic AC power of the power value P ₁ and the power value P _{The two} superimposed powers are periodically superimposed on the basic AC power at a predetermined supply time T and a predetermined time interval t. When the measured value of the lighting voltage of the discharge lamp 10 becomes higher than the predetermined reference value V ₀ , the superimposed power of the predetermined power value P ₃ higher than the power value P ₂ is given to the discharge lamp 10 by the predetermined supply time T and The basic AC power is periodically superimposed and supplied at the time interval t, that is, the power value of the superimposed power is changed from P ₂ to P ₃ higher than that. When the measured value of the lighting voltage of the discharge lamp 10 becomes lower than the predetermined reference value V ₀ again, the superimposed power of the predetermined power value P ₂ is basically applied to the discharge lamp 10 at the predetermined supply time T and time interval t. The AC power is periodically superimposed and supplied, that is, the power value of the superimposed power is changed from P ₃ to P ₂ .

In such a power supply device, a specific example of the set value of the supplied power in the low power lighting mode is given. When the rated power of the discharge lamp 10 is 230 W, the power value P ₁ of the basic AC power is 138 W. (60% of rated power), power value P _{2 of} superimposed power is 35 W, power value P ₃ is 92 W, supply time T of superimposed power is 2 minutes, time interval t of superimposed power is 15 minutes, and when power is not superimposed The reference value V _{0 of the} lighting voltage to be measured is 70V.

FIG. 5 is a diagram illustrating a change in the power value supplied to the discharge lamp together with a change in the lighting voltage of the discharge lamp in a low power lighting mode in still another example of the power supply apparatus.
The power supply apparatus of this example controls the supply time of superimposed power according to the measured value of the lighting voltage of the discharge lamp 10 in the low power lighting mode. More specifically, when the measured value of the lighting voltage of the discharge lamp 10 is lower than a predetermined reference value V ₀ , the discharge lamp 10 is supplied with the basic AC power of the power value P ₁ and the power value P _{The two} superimposed powers are periodically superimposed on the basic AC power at a predetermined supply time T ₁ and a predetermined time interval t. When the measured value of the lighting voltage of the discharge lamp 10 becomes higher than a predetermined reference value V _{0, a} predetermined supply time T ₂ and a time when the superimposed power of the power value P ₂ is longer than the supply time T _{1 in} the discharge lamp 10. The basic AC power is periodically superimposed and supplied at an interval t, that is, the supply time of the superimposed power is changed from T ₁ to T ₂ longer than that. Further, when the measured value of the lighting voltage of the discharge lamp 10 becomes lower than the predetermined reference value V ₀ again, the superimposed power of the predetermined power value P ₂ is applied to the discharge lamp 10 at the predetermined supply time T ₁ and time interval t. The basic AC power is periodically superimposed and supplied, that is, the supply time of the superimposed power is changed from T ₂ to T ₁ .

In such a power supply device, a specific example of the set value of the supplied power in the low power lighting mode is given. When the rated power of the discharge lamp 10 is 230 W, the power value P ₁ of the basic AC power is 138 W. (60% of the rated power), power value P ₂ of superimposed power is 35 W, supply time T _{1 of} superimposed power is 2 minutes, supply time T ₂ is 4 minutes, time interval t of superimposed power is 15 minutes, and power is not superimposed The reference value V _{0 of the} lighting voltage measured at the time is 70V.

  According to the discharge lamp lighting device of the present invention, in the low power lighting mode in which the power supply device supplies power lower than the rated power to the discharge lamp 10, the discharge lamp 10 is superimposed on the basic AC power having a predetermined power value. Superimposing power is periodically supplied, and according to the measured value of the lighting voltage of the discharge lamp 10, the superimposing power supply time, superimposing power value or superimposing power supply time is controlled, Since the amount of the evaporated electrode material existing around the electrodes 14 and 15 of the discharge lamp 10 is increased, thereby promoting the deposition of the evaporated electrode material on the electrodes 14 and 15 of the discharge lamp 10, the discharge lamp 10 The wear and flickering of the electrodes 14 and 15 can be prevented or suppressed.

The discharge lamp lighting device of the present invention is not limited to the above embodiment, and various changes can be made.
Each of the power supply apparatuses in the above-described embodiments controls one of the supply time of the superimposed power, the power value of the superimposed power, and the supply time of the superimposed power according to the measured value of the lighting voltage of the discharge lamp 10. However, even if it controls two of the superimposed power supply timing, the superimposed power power value, and the superimposed power supply time, the superimposed power supply timing, the superimposed power power value, and the superimposed power supply It may control all of the time.
In addition, the power supply apparatus sets two or more reference values of the lighting voltage of the discharge lamp 10, and controls the supply time of the superimposed power, the power value of the superimposed power, or the supply time of the superimposed power based on each reference value. It may be a thing.
In addition, when the measured value of the lighting voltage of the discharge lamp is lower than a predetermined reference value, the power feeding device may be one in which the supply of superimposed power is set to 0 (a state in which the superimposed power is not supplied). Moreover, the form of the electrode of the discharge lamp is not limited to that shown in FIG. 1, and may have, for example, a truncated cone-shaped head.

[Production of discharge lamp]
A discharge lamp (A) having the following specifications was produced according to the configuration shown in FIG.

Discharge lamp (A):
The arc tube is made of quartz glass, the maximum outer diameter of the light emitting part is 10 mm, and the inner volume of the light emitting part is 65 mm ³ .
Each of the electrodes is made of tungsten, and the distance between the electrodes is 1.0 mm.
In the arc tube, 0.3 mg / mm ³ mercury, 13 kPa argon gas at static pressure, and 4.0 × 10 ⁻⁴ μmol / mm ³ halogen (Br) are sealed.
The rated power of the discharge lamp (A) is 230 W, the rated voltage is 80 V, and the tube wall load value is 2.5 W / mm ² .

<Experimental example 1>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
-Superimposed power value: 35 W (the total of basic AC power and superimposed power is 173 W)
・ Supply time: 2 minutes ・ Time interval:
When the measured value of the lighting voltage when the superimposed power is supplied is 80 V or less; 15 minutes When the measured value of the lighting voltage when the superimposed power is supplied exceeds 80 V; 5 minutes

<Experimental example 2>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
-Superimposed power value: 35 W (the total of basic AC power and superimposed power is 173 W)
・ Supply time: 2 minutes ・ Time interval:
When the measured value of the lighting voltage when the superimposed power is supplied is less than 80 V; 15 minutes When the measured value of the lighting voltage when the superimposed power is supplied is 80 V or more and less than 100 V; When the measured value of lighting voltage when supplied is 100V or higher; 5 minutes

<Experimental example 3>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
-Superimposed power value: 35 W (the total of basic AC power and superimposed power is 173 W)
·Time interval:
When the measured value of the lighting voltage when the superimposed power is not supplied is less than 75 V; 5 minutes When the measured value of the lighting voltage when the superimposed power is not supplied is 75 V or more; 15 minutes ・ Supply time: 2 minutes

<Experimental example 4>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
-Superimposed power value: 35 W (the total of basic AC power and superimposed power is 173 W)
・ Supply time:
When the measured value of the lighting voltage when the superimposed power is not supplied is less than 70 V; 2 minutes When the measured value of the lighting voltage when the superimposed power is not supplied is 70 V or more; 4 minutes and time interval: 15 minutes

<Experimental example 5>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
・ Superimposed power value:
When the measured value of the lighting voltage when the superimposed power is not supplied is 70 V or less; 35 V (the total of the basic AC power and the superimposed power is 173 W)
When the measured value of the lighting voltage when superimposing power is not supplied exceeds 70 V; 92 V (the total of basic AC power and superimposing power is 230 W)
・ Time interval: 15 minutes ・ Supply time: 2 minutes

<Experimental example 6>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
・ Superimposed power value:
When the measured value of the lighting voltage when the superimposed power is not supplied is 70 V or less; 35 V (the total of the basic AC power and the superimposed power is 173 W)
When the measured value of the lighting voltage when superimposing power is not supplied exceeds 70 V; 92 V (the total of basic AC power and superimposing power is 230 W)
・ Time interval: 15 minutes ・ Supply time: 2 minutes When the measured value of the lighting voltage when the superimposed power is not supplied is 70 V or less; for 3 minutes, the measured value of the lighting voltage when the superimposed power is not supplied is 70 V Over 4 minutes

<Experimental example 7>
By supplying basic AC power and superimposed power to the discharge lamp (A) according to the following conditions, the discharge lamp (A) is lit for 200 hours, and then the light emitted from the discharge lamp (A) is visually observed. When observed, the generation of flicker was not recognized, and when the electrode of the discharge lamp (A) was observed, no abnormality was observed.

[Basic AC power]
・ Current frequency: 740Hz
・ Power value: 138W (60% of rated power value)
[Superimposed power]
・ Current frequency: 518Hz
・ Superimposed power value: 35V
・ Time interval: 5 minutes at minimum ・ Supply time:
When the measured value of the lighting voltage when the superimposed power is not supplied is 70 V or less; 0 minute When the measured value of the lighting voltage when the superimposed power is not supplied exceeds 70 V; 2 minutes

<Comparative Experiment Example 1>
After supplying the discharge lamp (A) with AC power having a current frequency of 740 Hz and a power value of 138 W (60% of the rated power value), the discharge lamp (A) is lit for 200 hours, and then the discharge lamp ( When the light emitted from A) was visually observed, the occurrence of flicker was observed. Moreover, when the electrode of the discharge lamp (A) was observed, it was found that the tip was worn.

DESCRIPTION OF SYMBOLS 10 Discharge lamp 11 Light emission tube 12 Light emission part 13 Sealing part 14,15 Electrode 14a, 15a Head part 14b, 15b Shaft part 14c, 15c Coil part 16,17 Metal foil 18,19 External lead p1 Protrusion S Discharge space

Claims (6)

In a discharge lamp lighting device comprising a discharge lamp and a power supply device for supplying AC power to the discharge lamp,
The power supply device has a function of switching on a rated power lighting mode for supplying rated power to the discharge lamp and a low power lighting mode for supplying power lower than rated power to the discharge lamp to light the discharge lamp. In the low power lighting mode, the basic AC power of a predetermined power value is continuously supplied to the discharge lamp, and the superimposed power superimposed on the basic AC power is periodically supplied, and A discharge lamp lighting device that controls a supply time of superimposed power, a power value of superimposed power, or a supply time of superimposed power according to a measured value of a lighting voltage of the discharge lamp.   In the low power lighting mode, when the measured value of the lighting voltage of the discharge lamp is higher than a predetermined reference value, the power feeding device has the superimposed power at a shorter time interval than when the measured value is lower than the predetermined reference value. 2. The discharge lamp lighting device according to claim 1, wherein a supply timing of the superimposed power is controlled so as to be supplied to the discharge lamp. 3.   In the low power lighting mode, when the measured value of the lighting voltage of the discharge lamp is higher than a predetermined reference value, the power feeding device has a higher power value than that when the measured value is lower than the predetermined reference value. 3. The discharge lamp lighting device according to claim 1, wherein a power value of the superimposed power is controlled so as to be supplied to the discharge lamp. 4.   In the low power lighting mode, when the measured value of the lighting voltage of the discharge lamp is higher than a predetermined reference value, the power feeding device supplies the superimposed power in a longer time than when the measured value is lower than the predetermined reference value. The discharge lamp lighting device according to any one of claims 1 to 3, wherein a supply time of the superimposed power is controlled so as to be supplied to the discharge lamp.   The discharge lamp lighting device according to any one of claims 1 to 4, wherein the measured value of the lighting voltage of the discharge lamp is measured when the superimposed power is not supplied.   The discharge lamp lighting device according to any one of claims 1 to 4, wherein a measured value of a lighting voltage of the discharge lamp is measured when the superimposed power is supplied.

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