JP2003257687A - High pressure discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of high frequency lighting a high pressure discharge lamp. <P>SOLUTION: When starting the operation (Step S100), the high pressure discharge lamp 7 is lighted so as to be identical to the non-resonance frequency (Step S101). Then the lighting frequency is lowered (Step S102), and determination is made whether the tube voltage has risen approximately 1 V (Step S103). If yes, the lighting frequency is raised from that point (Step S104), and determination is made whether the tube voltage has risen approximately 1 V (step S105). If yes, the lighting frequency is sunk (Step S102). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art FIG. 14 is a circuit diagram of a conventional high pressure discharge lamp lighting device. In FIG. 14, 1 is a DC power supply, 2 is an inverter circuit composed of a first switching element 2a and a second switching element 2b for converting the DC voltage of the DC power supply 1 into a high frequency voltage, and 3 is an inverter circuit 2
Is a control circuit for controlling the drive frequency of each switching element constituting the above, 4 is a load circuit including the resonance capacitor 5 and the choke coil 6, and 7 is a high pressure discharge lamp which is lit at a high frequency by the output voltage from the load circuit 4.

In the high pressure discharge lamp lighting device having such a structure, the control circuit 3 drives and controls each switching element so that a high frequency voltage having a frequency of 10 kHz or more is supplied to the high pressure discharge lamp 7 through the load circuit 4. . Further, the control circuit 3 controls the lighting frequency of the high pressure discharge lamp 7 in order to prevent the occurrence of an acoustic resonance phenomenon of "extinguishing" or "fluctuation" due to the curve of the discharge arc in the arc tube of the high pressure discharge lamp 7, which is generally known. Decide on the non-resonant frequency that the high-pressure discharge lamp has,
Drive and control each switching element.

As a conventional example, Japanese Patent Laid-Open No. 30359/1991.
The high-pressure discharge lamp lighting device disclosed in Japanese Patent No. 2 is cited. This is provided with an FM modulation circuit that monotonically increases the lighting frequency according to the magnitude of the DC voltage of the DC power supply. As a result, the lighting frequency is set within the non-resonant frequency band to stably light the high pressure discharge lamp, and even when there is a voltage change, the power supplied to the high pressure discharge lamp is always kept constant to maintain a predetermined brightness. Is configured as follows.

[0005]

The conventional high pressure discharge lamp lighting device is configured to light the high pressure discharge lamp by previously determining the lighting frequency to the non-resonant frequency of the high pressure discharge lamp as described above. However, in general, high-pressure discharge lamps change the speed of sound waves in the arc tube according to the cumulative lighting time,
Alternatively, it is known that the non-resonant frequency band also changes due to wear of the electrodes. Therefore, an acoustic resonance phenomenon occurs due to the lighting frequency entering the resonance frequency band due to various factors, and the lighting state of the high-pressure discharge lamp cannot be kept stable.

The present invention has been made in order to solve the above-mentioned problems, and even if the non-resonant frequency band changes due to various factors, the lighting frequency is always set within the frequency band. However, it does not cause "disappearance" or "fluctuation" of the discharge arc in the arc tube.
A high pressure discharge lamp lighting device for stably lighting a high pressure discharge lamp at a high frequency.

[0007]

A high pressure discharge lamp lighting device according to the present invention controls a high pressure discharge lamp, a high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, and an output frequency of the high frequency power supply circuit. In a high-pressure discharge lamp lighting device including a control circuit, the control circuit sets the output frequency of the high-frequency power supply circuit to a non-resonant frequency band of the high-pressure discharge lamp, and repeatedly changes up and down within the frequency band. It was done.

Further, the high pressure discharge lamp, the high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, the control circuit for controlling the output frequency of the high frequency power supply circuit, and the voltage detection for detecting the tube voltage of the high pressure discharge lamp. In the high pressure discharge lamp lighting device including means, the control circuit repeatedly changes the output frequency of the high frequency power supply circuit up and down so that the tube voltage of the high pressure discharge lamp does not exceed a predetermined fluctuation range, and the tube voltage is applied. When rising above the fluctuation range, the direction of change is reversed and changed.

Further, the high-pressure discharge lamp, the high-frequency power supply circuit for supplying high-frequency power to the high-pressure discharge lamp, the control circuit for controlling the output frequency of the high-frequency power supply circuit, and the voltage detection for detecting the tube voltage of the high-pressure discharge lamp. In the high pressure discharge lamp lighting device including the means, the control circuit repeatedly changes the output frequency of the high frequency power supply circuit up and down so that the tube voltage of the high pressure discharge lamp does not exceed a predetermined value.

Further, the tube voltage of the high-pressure discharge lamp is sampled at every predetermined time to calculate an average voltage, and the operation of the high frequency power supply circuit is stopped when the average voltage reaches a predetermined value or more. Is.

Further, the control circuit is such that the changing rate of the decrease and increase of the output frequency of the high frequency power supply circuit is made different.

Further, the control circuit changes the output frequency of the high frequency power supply circuit in correlation with the tube voltage of the high pressure discharge lamp.

Further, the control circuit changes the output frequency of the high frequency power supply circuit repeatedly up and down and changes it in correlation with the output frequency so that the load current or the supplied power flowing through the high pressure discharge lamp becomes constant. It is the one.

Further, the control circuit changes the output frequency of the high frequency power supply circuit after a predetermined elapsed time from the start of lighting.
Alternatively, it is started when the tube voltage of the high pressure discharge lamp reaches a predetermined value or more.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a circuit configuration diagram showing a high pressure discharge lamp lighting device according to a first embodiment. In FIG. 1, the difference from the conventional example is that a voltage detector 8 for detecting the tube voltage of the high pressure discharge lamp 7 having a rating of 35 W is provided. Then, the control circuit 9 controls the drive frequency of the inverter circuit 2 so as to preset the lighting frequency within the non-resonant frequency band of 40 KHz to 45 KHz in which the acoustic resonance phenomenon does not occur. FIG. 2 is a characteristic diagram showing the relationship between the lighting frequency and the tube voltage. It can be seen that the tube voltage is high in the resonance frequency band where the acoustic resonance phenomenon occurs, and the tube voltage is low and shows a constant state in the non-resonance frequency band.

Next, the lighting operation of the high pressure discharge lamp lighting device having such a structure will be described with reference to the flow charts shown in FIGS. 1 and 3. When the operation of the lighting device is started (step S100), the control circuit 9 controls the drive frequency of the inverter circuit 2 so that the initial lighting frequency matches the non-resonant frequency, and the high pressure discharge lamp 7 is lit (step S100). S101). Thereafter, the drive frequency of the inverter circuit 2 is changed to decrease the lighting frequency (step S102), and the tube voltage of the high pressure discharge lamp 7 is detected by the voltage detector 8 in this process. Next, the control circuit 9 determines whether or not the detected voltage of the voltage detector 8 has risen by, for example, about 1 V (step S103), and if NO here, continues to lower the lighting frequency. If YES, it is determined that the tube voltage has approached the resonance frequency band.

Next, the driving frequency of the inverter circuit 2 is changed so as to raise the lighting frequency from that point (step S104), and in this process, it is judged whether the tube voltage has risen by, for example, about 1 V as described above. Yes (Step S
105). Here, in the case of NO, the increase of the lighting frequency is continued, and in the case of YES, it is determined that the tube voltage has approached the resonance frequency band, and the lighting frequency is lowered again from that point (step S102). By repeating such a series of steps, even if the non-resonant frequency band changes due to the change over time of the high pressure discharge lamp 7, the high frequency discharge lamp 7 can be turned on by always setting the lighting frequency within that frequency band. Further, the control circuit 9 determines whether or not the lighting end signal is received when the lighting frequency is lowered and moved upward (step S106), and in the case of NO, the high pressure discharge lamp 7 is kept lighting. In the case of YES, the high pressure discharge lamp 7 is turned off and the operation of the lighting device is ended (step S107).

In the process of the flow chart of FIG. 3, the detected voltage from the voltage detector 8 is sampled every predetermined time to calculate an average value, and when the average value is equal to or more than the predetermined value, May determine that the high pressure discharge lamp 7 has reached the end of its life and incorporate means for stopping the operation of the lighting device. The same applies to the second embodiment.

Further, in the process shown in the flow chart of FIG. 3, the control circuit 9 performs the operation of changing the driving frequency of the inverter circuit 2 to change the lighting frequency after a predetermined elapsed time from the start of lighting or at a high voltage. A starting means to be executed when the tube voltage of the discharge lamp 7 reaches or exceeds a predetermined value may be incorporated. The same applies to the second embodiment.

The lighting operation of the lighting device will be described with reference to the timing chart shown in FIG. In FIG. 4, at the time T0 of starting the lighting of the high pressure discharge lamp 7, the lighting frequency is set to a predetermined frequency f0 in the non-resonant frequency band, and the tube voltage at that time indicates V0. Then, the lighting frequency is changed from f0 to f
It is lowered to 1, and the tube voltage shows V1 at the point of the lighting frequency f1, that is, at time T1. Next, the lighting frequency is increased to f2 with f1 as the base point, and the tube voltage shows V1 at the lighting frequency f2, that is, at the time T2. in this way,
By the control sequence of moving the lighting frequency down / up at the point where the tube voltage indicates V1, the lighting frequency can always be set within the non-resonant frequency band, and the high-pressure discharge lamp 7 can be lit stably.

As described above, the high-pressure discharge lamp 7 is devised so that the lighting frequency is always set within the non-resonant frequency band even if the non-resonant frequency band changes with the aging of the high-pressure discharge lamp 7. Due to the configuration in which the light is turned on stably, the acoustic resonance phenomenon can be avoided. Further, the end of life of the high pressure discharge lamp 7 can be detected by a simple method, and the operation of the lighting device can be stopped to protect the device itself.

Embodiment 2. FIG. 5 is a flow chart showing the operation flow of the high pressure discharge lamp lighting device according to the second embodiment. The circuit configuration diagram of the high pressure discharge lamp lighting device is the same as that of the first embodiment. In the flowchart shown in FIG. 5, when the operation of the lighting device is started (step S200), the control circuit 9 controls the drive frequency of the inverter circuit 2 so that the initial lighting frequency matches the non-resonant frequency, and the high voltage is applied. The discharge lamp 7 is turned on (step S20)
1). Thereafter, the lighting frequency is lowered (step S202), and it is determined whether or not the detection voltage of the voltage detector 8, that is, the tube voltage has reached the threshold value V1 in this process (step S203).

The reason why the threshold value V1 is set is that, for example, as shown in the tube voltage characteristic diagram of FIG. 6, when the high pressure discharge lamp 7 having the characteristic that the tube voltage has a hollow shape in the non-resonant frequency band is turned on. This is because the lighting frequency is changed as widely as possible from the initial lighting frequency f0 until the tube voltage V1 corresponding to the lower limit value f1 and the upper limit value f2 of the non-resonance frequency band is reached.

Next, in the case of NO in the above process, that is, when the tube voltage has not reached the threshold value V1, the lighting frequency is continuously decreased. If YES, the tube voltage is the threshold value V
Since it can be determined that the frequency reaches 1 and approaches the resonance frequency band, the drive frequency of the inverter circuit 2 is changed so as to increase the lighting frequency from that point, and it is determined whether the tube voltage has reached the threshold V1 in this process. Yes (Step S
205). Here, in the case of NO, since the tube voltage has not reached the threshold value V1, the lighting frequency is continuously increased, and Y
In the case of ES, it is determined that the tube voltage has approached the resonance frequency band because it has reached the threshold value V1, and the lighting frequency is again lowered from that point (step S202). By repeating such a series of steps, it is possible to always set the lighting frequency within the non-resonant frequency band and light the high-pressure discharge lamp 7.

The lighting operation of the lighting device will be described with reference to the timing chart shown in FIG. In FIG. 7, at the start of lighting T0, the lighting frequency is set to the initial lighting frequency f.
The tube voltage at that time indicates V0. And
The lighting frequency is decreased and the tube voltage reaches the threshold value V1 at the lighting frequency f1, that is, at the time T1. Therefore, the lighting frequency is increased to f2 with f1 as the base point. Next, since the tube voltage reaches the threshold value V1 at the point of the lighting frequency f2, that is, at the time T2, the lighting frequency is f2 with f2 as the base point.
Lower to 1. In this way, the lighting frequency is constantly set within the non-resonant frequency band by the control sequence in which the lighting frequency repeatedly decreases and rises when the tube voltage reaches the threshold value V1, and the high-pressure discharge lamp 7 is stably lit. You can

As described above, even if the non-resonance frequency band changes due to the aging of the high-pressure discharge lamp 7, the high-pressure discharge lamp 7 is lit by devising such that the lighting frequency is always set to the non-resonance frequency band. With this configuration, the acoustic resonance phenomenon can be avoided.

Embodiment 3. The third embodiment shows an example of a specific method for lowering and raising the lighting frequency within the non-resonant frequency band. The circuit configuration diagram of the high pressure discharge lamp lighting device is the same as that of the first embodiment. In the case of the high pressure discharge lamp 7 having a tube voltage characteristic in which the voltage gradient on the upper limit side of the non-resonance frequency band is significantly larger than that on the lower limit side as shown in FIG. When the response of the detector 8 is slow, the lighting frequency may overshoot and enter the resonance frequency band. In general, it is desirable that the changing rate of the lighting frequency is fast so that the change in brightness cannot be visually recognized. Therefore, as shown in the timing chart of FIG. 8, the control circuit 9 uses the inverter so that the time t1 when increasing the lighting frequency f1 to f2 is longer than the moving time t2 when decreasing the lighting frequency f2 to f1. As a result of controlling the drive frequency of the circuit 2, it is possible to prevent the overshoot by slowing down the rate of change when increasing the lighting frequency. On the other hand, the rate of change of the lighting frequency when it falls may be increased in the same manner as described above to increase the overall average speed.

As another example of the method of preventing the overshoot of the lighting frequency, the lighting frequency may be monotonically decreased based on the magnitude of the tube voltage as shown in the timing chart of FIG. . That is, when the lighting frequency falls and rises, the control circuit 9 increases the moving speed until the tube voltage reaches a predetermined value, and approaches the resonance frequency band when the tube voltage reaches the predetermined value. It is also possible to control the drive frequency of the inverter circuit 2 so as to slow down the moving speed when it judges that the above.

As described above, since the changing rate of the lighting frequency is appropriately adjusted, the high frequency discharge lamp 7 is reliably lit in the non-resonant frequency band without causing the lighting frequency to overshoot, and the acoustic Resonance phenomenon can be avoided.

Fourth Embodiment FIG. 10 is a circuit configuration diagram showing the high pressure discharge lamp lighting device of the fourth embodiment. In FIG. 10, a difference from the first embodiment is that a current detector 11 that detects a load current flowing in a high pressure discharge lamp 7 having a rating of 35 W through a resistor 10 connected to an inverter circuit 2 is provided. is there. Then, the control circuit 9 is always based on the current detected by the current detector 11 even when the load current changes due to variations in the characteristics of the high-pressure discharge lamp 7 or the choke coil 6 which is a circuit component, and changes over time in the high-pressure discharge lamp 7. The moving speed of the lighting frequency is changed so that the load current flowing through the high-pressure discharge lamp 7 reaches the target current value.

Next, the manner in which the lighting frequency falls and rises in the non-resonant frequency band will be described with reference to the interrupt flowchart shown in FIG. The operation contents of the entire lighting device are the same as those in the first or second embodiment. In FIG. 11, the control circuit 9 sets the rate of change of the lighting frequency to the initial value v0 (step S300), and lowers and increases the lighting frequency. In this process, the detected current of the current detector 11, that is, the load current is sampled several times (step S301), and the average load current is obtained.

Then, the control circuit 9 calculates the difference A between the target current value and the average load current value (step S302), and thereafter judges whether 0 <A (step S3).
03). Here, if YES, that is, if the average load current value is smaller than the target current value, the rate of change is monotonically increased in correlation with the absolute value of the lighting frequency (step S30).
4) If NO, that is, if the average load current value is larger than the target current value, the rate of change is monotonically reduced in correlation with the absolute value of the lighting frequency (step S305). Next, the timer circuit stored in the control circuit 9 is operated so that the rate of change of the lighting frequency monotonically increases or decreases monotonically for a predetermined time (step S306). After this, the load current is sampled again several times (step S301), and the average load current is obtained. After this,
The same steps as described above are repeated.

FIG. 12 is a timing chart showing a monotonic increase in the above 0 <A, that is, when the load current flowing through the high pressure discharge lamp 7 is smaller than the target current.
The average value fh of the lighting frequency is smaller than the average value fx of the lighting frequency at v0 when the speed of change is constant. As a result, the load current increases, so the power supplied to the high-pressure discharge lamp 7 increases and the brightness increases. On the other hand, FIG. 13 is a timing chart showing a monotonous decrease when A <0, that is, when the load current is larger than the target current, and the average value fh of the lighting frequency is the average value fx of the lighting frequency at the moving speed v0. It is increasing in comparison. As a result, the load current becomes smaller, so the power supplied to the high-pressure discharge lamp 7 decreases and the brightness decreases.

As described above, the rate of change of the lighting frequency is monotonically increased or decreased according to the magnitude of the load current flowing through the high-pressure discharge lamp 7, and the average value of the lighting frequency is appropriately adjusted, whereby the high-pressure discharge lamp is adjusted. The brightness of 7 becomes the target level, and the acoustic resonance phenomenon can be avoided.

In the first to fourth embodiments,
In the initial stage, the high-pressure discharge lamp 7 rated at 35 W is operated at 40 kHz.
Although the example of lighting in the non-resonant frequency band of up to 45 kHz has been described, it may be configured to light in the other non-resonant frequency band. Furthermore, high pressure discharge lamps 7 with other rated capacity
May be configured to illuminate within these non-resonant frequency bands.

[0036]

Since the present invention is constructed as described above, it has the following effects.

The high pressure discharge lamp lighting device according to the present invention comprises a high pressure discharge lamp, a high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, and a control circuit for controlling the output frequency of the high frequency power supply circuit. In the high-pressure discharge lamp lighting device, the control circuit sets the output frequency of the high-frequency power supply circuit to the non-resonant frequency band of the high-pressure discharge lamp, and since it is repeatedly changed up and down within the frequency band,
Even if the non-resonant frequency band changes due to aging of the high-pressure discharge lamp, the lighting frequency can always be set within the non-resonant frequency band to ensure stable lighting of the high-pressure discharge lamp and avoid the effects of the acoustic resonance phenomenon. it can.

Further, the high pressure discharge lamp, the high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, the control circuit for controlling the output frequency of the high frequency power supply circuit, and the voltage detection for detecting the tube voltage of the high pressure discharge lamp. In the high pressure discharge lamp lighting device including means, the control circuit repeatedly changes the output frequency of the high frequency power supply circuit up and down so that the tube voltage of the high pressure discharge lamp does not exceed a predetermined fluctuation range, and the tube voltage is applied. When the voltage rises beyond the fluctuation range, the direction of change is reversed and changed, so even if the non-resonance frequency band changes due to the aging of the high-pressure discharge lamp, the lighting frequency is always set to the non-resonance frequency band. It can be set inside to avoid the influence of the acoustic resonance phenomenon.

Further, the high pressure discharge lamp, the high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, the control circuit for controlling the output frequency of the high frequency power supply circuit, and the voltage detection for detecting the tube voltage of the high pressure discharge lamp. In the high pressure discharge lamp lighting device provided with means, the control circuit repeatedly changes the output frequency of the high frequency power supply circuit up and down so that the tube voltage of the high pressure discharge lamp does not exceed a predetermined value. It is possible to avoid the influence of the acoustic resonance phenomenon by always setting the lighting frequency within the non-resonant frequency band without being restricted by the tube voltage characteristic of No.

Further, the tube voltage of the high-pressure discharge lamp is sampled at every predetermined time to calculate an average voltage, and when the average voltage exceeds a predetermined value, the operation of the high frequency power supply circuit is stopped. The end of life of the high pressure discharge lamp can be detected by a simple method, and the operation of the lighting device can be stopped to protect the device itself.

Further, since the control circuit makes the output frequency of the high-frequency power supply circuit decrease and rise at different speeds, the frequency overshoot at the time of movement is suppressed and the output frequency is surely kept within the non-resonant frequency band. The high pressure discharge lamp can be lit stably.

Further, since the control circuit changes the changing rate of the output frequency of the high-frequency power supply circuit in correlation with the tube voltage of the high-pressure discharge lamp, the frequency overshoot when the lighting frequency falls or rises. Therefore, the high pressure discharge lamp can be reliably turned on in the non-resonant frequency band.

In addition, the control circuit changes the rate at which the output frequency of the high frequency power supply circuit repeatedly changes up and down so as to correlate with the output frequency so that the load current or the supplied power flowing through the high pressure discharge lamp becomes constant. Therefore, the load current value flowing through the high-pressure discharge lamp can always be set to the target current value, and the brightness of the high-pressure discharge lamp can be maintained at the target level.

Further, the control circuit changes the output frequency of the high frequency power supply circuit after a predetermined elapsed time from the start of lighting.
Alternatively, since it is started when the tube voltage of the high-pressure discharge lamp reaches a predetermined value or more, the lighting frequency can be moved when the high-pressure discharge lamp reaches the stable region, and the non-resonance frequency band can be reliably generated. The high pressure discharge lamp can be lit inside.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a first embodiment according to a high pressure discharge lamp lighting device of the present invention.

FIG. 2 shows a tube voltage characteristic diagram of a high pressure discharge lamp.

FIG. 3 is a flowchart showing a flow of a lighting operation according to the first embodiment.

FIG. 4 shows a timing chart of the lighting operation of the first embodiment.

FIG. 5 is a flowchart showing a flow of a lighting operation according to the second embodiment.

FIG. 6 is a tube voltage characteristic diagram of another high pressure discharge lamp.

FIG. 7 shows a timing chart of a lighting operation according to the second embodiment.

FIG. 8 shows a timing chart of a lighting operation according to the third embodiment.

FIG. 9 shows a timing chart of another lighting operation according to the third embodiment.

FIG. 10 shows a circuit configuration diagram of a high pressure discharge lamp lighting device according to a fourth embodiment.

FIG. 11 is a flowchart showing a flow of a lighting operation according to the fourth embodiment.

FIG. 12 shows a timing chart of a lighting operation according to the fourth embodiment.

FIG. 13 shows a timing chart of another lighting operation according to the fourth embodiment.

FIG. 14 is a circuit configuration diagram showing a conventional high pressure discharge lamp lighting device.

[Explanation of symbols]

1 DC power supply, 2 inverter circuit, 3 control circuit, 4
Load circuit, 5 resonance capacitor, 6 choke coil, 7 high pressure discharge lamp, 8 voltage detector, 9 control circuit,
10 resistance, 11 current detector.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K072 AA11 AC02 AC11 BA03 BC01                       BC03 CA03 CA04 CA07 DD03                       DD04 DE02 DE04 DE06 GB12                       HA05 HA06

Claims (8)

[Claims] 1. A high pressure discharge lamp lighting device comprising: a high pressure discharge lamp; a high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp; and a control circuit for controlling an output frequency of the high frequency power supply circuit. The high-pressure discharge lamp lighting device, wherein the control circuit sets the output frequency of the high-frequency power supply circuit to a non-resonant frequency band of the high-pressure discharge lamp and repeatedly changes the output frequency up and down within the frequency band. 2. A high pressure discharge lamp, a high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, a control circuit for controlling an output frequency of the high frequency power supply circuit, and a tube voltage of the high pressure discharge lamp. In the high pressure discharge lamp lighting device having a voltage detecting means for controlling the output voltage of the high frequency power supply circuit, the control circuit repeatedly changes the output frequency up and down so that the tube voltage of the high pressure discharge lamp does not exceed a predetermined fluctuation range. , When the tube voltage rises beyond the fluctuation range,
A high pressure discharge lamp lighting device characterized in that the direction of change is reversed and changed. 3. A high pressure discharge lamp, a high frequency power supply circuit for supplying high frequency power to the high pressure discharge lamp, a control circuit for controlling an output frequency of the high frequency power supply circuit, and a tube voltage of the high pressure discharge lamp. In the high pressure discharge lamp lighting device provided with a voltage detecting means, the control circuit repeatedly changes the output frequency of the high frequency power supply circuit up and down so that the tube voltage of the high pressure discharge lamp does not exceed a predetermined value. A high pressure discharge lamp lighting device characterized by the above. 4. The tube voltage of the high-pressure discharge lamp is sampled every predetermined time to calculate an average voltage, and when the average voltage reaches a predetermined value or more, the operation of the high frequency power supply circuit is stopped. The high pressure discharge lamp lighting device according to any one of claims 1 to 3, characterized in that. 5. The high voltage according to any one of claims 1 to 3, wherein the control circuit is configured to make the changing speed of the decrease and increase of the output frequency of the high frequency power supply circuit different. Discharge lamp lighting device. 6. The control circuit is configured to change the rate of change of the output frequency of the high frequency power supply circuit in correlation with the tube voltage of the high pressure discharge lamp.
~ The high pressure discharge lamp lighting device according to claim 3. 7. The control circuit repeatedly changes the output frequency of the high frequency power supply circuit up and down so that the load current or the supplied power flowing through the high pressure discharge lamp becomes constant.
The high pressure discharge lamp lighting device according to any one of claims 1 to 3, wherein the high pressure discharge lamp lighting device is configured to change in correlation with an output frequency. 8. The control circuit starts changing the output frequency of the high-frequency power supply circuit after a predetermined elapsed time from the start of lighting or when the tube voltage of the high-pressure discharge lamp reaches a predetermined value or more. The method according to claim 1, wherein
~ The high pressure discharge lamp lighting device according to claim 7.