JP2003308989A - Lighting device for high pressure discharge lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting device for a high pressure discharge lamp, which can extract a proper lighting frequency in high-frequency lighting of the high pressure discharge lamp to surely prevent flicker or fading-out by an acoustic resonance phenomenon even when lamp characteristics vary. <P>SOLUTION: For the lighting device for a high pressure discharge lamp, which is equipped with the high pressure discharge lamp, an inverter circuit for supplying AC power of at least 1 kHz to the high pressure discharge lamp and a control circuit for controlling an output frequency of the inverter circuit, the control circuit is adapted to detect an upper end frequency or lower end frequency in a non-resonance frequency band to select an output frequency to a frequency within the non-resonance frequency band that is calculated out from the upper end frequency or lower end frequency. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art FIG. 9 is a circuit block diagram of a conventional high pressure discharge lamp lighting device. In FIG. 9, 1 is a DC power supply, 2 is an inverter circuit composed of switching elements 3 and 4 of MOS-FET, 5 is a control circuit for driving and controlling the switching elements 3 and 4 of the inverter circuit 2, and 6 is a choke. A load circuit 10 including a coil 7, a DC cut capacitor 8 and a starting circuit 9 is a high pressure discharge lamp (hereinafter referred to as a lamp).

Next, the operation of the high pressure discharge lamp lighting device configured as described above will be described. The inverter circuit 2
The switching elements 3 and 4 are alternately ON / OFF controlled by a frequency of several tens of kHz from the control circuit 5, and convert the output of the DC power supply 1 into a high frequency. The power converted into the high frequency is reduced by the choke coil 7, and the lamp 10 is turned on by the current resonance action with the DC cut capacitor 8. The starting circuit 9 applies a high voltage of several kV before the discharge of the lamp 10 is started in order to cause a dielectric breakdown between the electrodes, but is disconnected after the start of the discharge.

Further, when a high-pressure discharge lamp is lit at a high frequency, a so-called acoustic resonance phenomenon is generated in which the discharge arc is bent due to the interference effect of the traveling wave and the reflected wave of the sound wave in the lamp, which causes extinction and lamp destruction. It is known to occur easily. In particular, during high frequency lighting of 1 kHz or more, it is common to select a non-resonant frequency band in which an acoustic resonance phenomenon does not occur and lighting. If fr is the frequency that causes the acoustic resonance phenomenon, fr becomes a function that depends on the sound velocity v in the arc tube and the shape of the arc tube.
Is represented by v = (γRT / M) ^1/2 . Where γ:
Specific heat ratio, R: gas constant, T: tube temperature, M: average molecular weight Therefore, the control circuit 5 is configured to drive the inverter circuit 2 at a fixed frequency in the non-resonant frequency band that avoids this frequency fr. .

However, it is known that the non-resonant frequency band is not always constant. For example, the non-resonant frequency band may differ depending on the installation direction of the lamp. This is because the effect of geomagnetism and convection in the lamp tube on the discharge arc is different between when the lamp is lit vertically and when it is lit horizontally, so the frequency that causes the acoustic resonance phenomenon is slightly different, that is, , The non-resonant frequency bands are different. It is also known that the average molecular weight M changes due to the deterioration of the discharge substance in the tube due to the temporal change of the lamp, and the non-resonant frequency band moves due to the change of the sound velocity v. Therefore, the conventional high-pressure discharge lamp lighting device is lit at a constant frequency regardless of the state of the lamp, so if the non-resonance frequency band is moved due to some disturbance as described above to the lamp,
There is a problem that the acoustic resonance phenomenon cannot be avoided.

In order to avoid the above problems, Japanese Unexamined Patent Application Publication No. Hei 8-21
What is shown in 3183 is proposed. The above-mentioned JP-A-8-213183 moves the lighting frequency during lighting,
For example, the voltage across the lamp is detected, and control is performed so that the frequency at which the lamp voltage is minimized is selected. The relationship between the lamp voltage and the occurrence of the acoustic resonance phenomenon with respect to the lighting frequency is actually shown in FIG. 10, and it is found that the lamp voltage is high in the resonance frequency band and is low and stable in the non-resonance frequency band. ing. Therefore, it seems that there is no problem if the lamp is lit at a frequency that minimizes the lamp voltage.

[0007]

However, there are the following three problems in lighting by selecting the frequency that minimizes the lamp voltage. First, if the resonance frequency band is entered during the searching operation by frequency shift, the acoustic resonance phenomenon is unavoidable and eventually causes flicker and disappearance. Secondly, depending on variations in the lamp characteristics, the point where the lamp voltage becomes the minimum may be near the upper end or near the lower end of the non-resonant frequency band.
As a result, there will be a difference in the lamp current, that is, the brightness, and a separate output adjustment means will be required. Thirdly, when the width of the searching is large, the searching operation itself may affect the light output, which may cause the user to feel uncomfortable.

The present invention has been made to solve the above problems, and in high frequency lighting of a high pressure discharge lamp, the frequency shift when extracting an appropriate lighting frequency is minimized, and the lamp characteristics are improved. An object of the present invention is to provide a high pressure discharge lamp lighting device capable of maintaining a constant lamp current without adding new control means even if there is a variation, and reliably preventing flickering and extinction due to an acoustic resonance phenomenon.

[0009]

According to a first aspect of the present invention, there is provided a high pressure discharge lamp lighting device, a high pressure discharge lamp, an inverter circuit for supplying alternating current power of 1 KHz or more to the high pressure discharge lamp, and the inverter circuit. And a control circuit for controlling the output frequency of the high pressure discharge lamp, wherein the control circuit detects the upper end frequency or the lower end frequency of one non-resonant frequency band, and is calculated from the upper end frequency or the lower end frequency. The output frequency is selected as one frequency within the non-resonant frequency band.

A high-pressure discharge lamp lighting device according to a second aspect of the present invention is a high-pressure discharge lamp, an inverter circuit for supplying alternating-current power of 1 KHz or more to the high-pressure discharge lamp, and a control circuit for controlling the output frequency of the inverter circuit. And a high-voltage discharge lamp lighting device comprising a discharge lamp voltage detection circuit for detecting the voltage across the high-pressure discharge lamp, at least starting lighting at a predetermined initial output frequency included in the non-resonant frequency band, The discharge lamp voltage of the high-pressure discharge lamp detected by the discharge lamp voltage detection circuit at the initial output frequency is recorded, and when the output frequency is increased or decreased by the control circuit, the discharge lamp voltage is recorded as the recorded discharge voltage. A frequency higher than the electric lamp voltage by a predetermined value is recorded, and the control circuit outputs the output frequency to the center side of the non-resonant frequency band by a predetermined frequency Δf from the recorded frequency. It is obtained so as to move the.

Further, in the high pressure discharge lamp lighting device according to a third aspect of the present invention, the control circuit detects the lower end frequency of the non-resonant frequency band and outputs a frequency higher than the lower end frequency by a predetermined frequency Δf. It is possible to switch between control to detect the upper end frequency of the non-resonant frequency band and output a frequency lower than the upper end frequency by a predetermined frequency Δf.

A high pressure discharge lamp lighting device according to a fourth aspect of the present invention includes an output mode switching circuit for switching between a high output mode and a low output mode, and when the high output mode is selected, the control circuit causes non-resonance. The lower end frequency of the frequency band is detected and a frequency higher than the lower end frequency by a predetermined frequency Δf is output. In the low output mode, the upper end frequency of the non-resonant frequency band is detected and the predetermined upper limit frequency is detected. A frequency lower by the frequency Δf is output.

According to a fifth aspect of the present invention, there is provided a high pressure discharge lamp lighting device including a current detection circuit for detecting a current flowing through the high pressure discharge lamp, wherein the value of Δf is variable based on the detected current, and the control is performed. The circuit is adapted to feed back the current flowing through the high pressure discharge lamp.

Further, in the high pressure discharge lamp lighting device according to the sixth aspect of the present invention, the control circuit repeats the movement of the output frequency continuously or at predetermined intervals.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to Embodiment 1 of the present invention. Incidentally, in FIG.
The same or corresponding parts are designated by the same reference numerals and the description thereof will be omitted. 11 is a frequency control circuit for controlling the output frequency, 12
Is a lamp voltage detection circuit for detecting, for example, an effective value of the voltage across the lamp 10.

The operation of the high pressure discharge lamp lighting device configured as described above will be described. The frequency control circuit 11 uses the lamp 1 detected by the lamp voltage detection circuit 12.
The output frequency is determined based on the voltage between both ends of 0 (hereinafter referred to as the lamp voltage), and the control circuit 5 outputs the output frequency to the inverter circuit 2 based on the information. FIG. 2 shows a flowchart of a method of determining the output frequency in the frequency control circuit 11. First, in S1, the control circuit 5 outputs the output frequency fL to the inverter circuit 2 as an initial frequency of, for example, the frequency fL = f0 that may be included in the non-resonant frequency band, and starts lighting. In S2, the lamp voltage V0 detected by the lamp voltage detection circuit 12 at the initial frequency f0 is recorded. Next, in S3, the output frequency fL
From the initial frequency f0, the lamp voltage Vx is Vx> V0
It descends to the point where it becomes + ΔV. Then, in S4,
Lamp voltage V detected by the lamp voltage detection circuit 12
It is determined whether x is Vx> V0 + ΔV, and if No, S
Return to 3. If Yes, in S5, Vx> V0 +
The frequency f1 when ΔV is recorded is recorded, and in S6,
Move the output frequency fL to the point where fL = f1 + Δf,
Lights at a frequency of fL = f1 + Δf. Then, after a predetermined interval is set in S7, the process returns to S2 and the above operation is repeated.

Although Δf is a fixed value in the above, Δf may be set to Δf = α × f1, (α is a constant), or the like.

FIG. 3 shows the relationship between the lighting frequency and the lamp voltage in the above operation. The horizontal axis represents the lighting frequency, and the vertical axis represents the lamp voltage. Note that FIG. 3 shows 40 to 45 kHz in a 35 W metal halide lamp with a rated power of a ceramic arc tube.
The figure shows the non-resonant frequency band in the vicinity as an example.
As shown in the example of FIG. 3, the lower end of the non-resonant frequency band and the constant frequency width Δf are always maintained for lighting.

As described above, since the frequency is moved so that the frequency width with the lower end frequency of the non-resonance frequency band is kept constant, an appropriate output frequency that avoids the acoustic resonance frequency band is extracted. In addition, it is possible to avoid flickering and disappearance due to the acoustic resonance phenomenon. Further, the width of frequency shift can be reduced, and the change in optical output due to frequency shift can be minimized.

Further, even if the lamp characteristic (the slope of the lamp voltage with respect to the frequency) varies a little, the lamp can always be turned on near the lower end of the non-resonant frequency band, and as a result, the variation in the light output can be suppressed.

In the above embodiment, the frequency width with the lower end frequency of the non-resonant frequency band is kept constant, but the frequency width with the upper end frequency is kept constant on the upper end side of the non-resonant frequency band. Even if it is kept, the same effect can be obtained. Further, it is desirable to select the side of the two resonance frequency bands sandwiching the non-resonance frequency band that is in contact with the weaker resonance degree.

Further, during the transient period when the lamp is turned on, the relative relationship between the upper and lower sides of the non-resonant frequency band changes in the degree of resonance. The control on the side may be switched on the way.

Further, the selection of the optimum switching timing, such as whether to switch between the upper end side and the lower end side before reaching stable lighting or after reaching stable lighting, depends on the lamp manufacturer and variations in lamp solids. Because they are different
It is desirable to set the control according to each characteristic.

Embodiment 2. FIG. 4 is a circuit configuration block diagram of the high pressure discharge lamp lighting device according to the second embodiment. 4, parts that are the same as or correspond to those in FIG. 1 of Embodiment 1 above are given the same reference numerals, and descriptions thereof will be omitted. Thirteen
Is an output mode switching circuit that switches between, for example, the rated lighting mode and the low output mode in response to a command from the outside.
With the output mode switching circuit 13, the frequency control circuit 11 selects a frequency near the lower end of the non-resonant frequency band in the rated lighting mode, and selects a frequency near the upper end of the non-resonant frequency band in the low output mode. is there. At the frequency near the upper end, the impedance of the choke coil 7 becomes higher than that at the frequency near the lower end, so that the load current (lamp current) is narrowed and dimmed, and the power consumption is also reduced accordingly.

In the first embodiment described above, in a lamp with a non-resonant frequency band that is not very wide, the frequency is moved to either the lower end or the upper end of the non-resonant frequency band to extract an appropriate output frequency and turn it on. However, in the present embodiment, in a lamp having a wide non-resonance frequency band, the frequency is moved at the lower end or the upper end of the non-resonance frequency band to extract an appropriate output frequency and turn it on. Is to do.

Next, the operation of the high pressure discharge lamp lighting device configured as described above will be described. Frequency control circuit 11
Determines the output frequency based on the lamp voltage of the lamp 10 detected by the lamp voltage detection circuit 12 based on the switching information between the rated lighting mode and the low output mode in the output mode switching circuit 13, The control circuit 5 outputs the information to the inverter circuit 2 based on the information. FIG. 5 shows a method of determining the output frequency fL near the lower end of the non-resonant frequency band or the output frequency fH near the upper end of the non-resonance frequency band based on the switching information between the rated lighting mode and the low output mode by the output mode switching circuit 13 in the frequency control circuit 11. The flowchart of is shown.

First, in S11, the control circuit 5 outputs the output frequency to the inverter circuit 2, for example, the initial frequency f0 which may be included in the non-resonant frequency band, and starts lighting. In S12, the lamp voltage V0 detected by the lamp voltage detection circuit 12 at the initial frequency f0 is recorded. Then, in S13, it is determined whether or not the output mode of the output mode switching circuit 13 is the low output mode, and if No, that is, in the rated lighting mode for extracting the frequency near the lower end of the non-resonant frequency band, S14. At, the output frequency fL is decreased from the initial frequency f0 to the point where the lamp voltage Vx is Vx> V0 + ΔV. Then, in S15, it is determined whether or not the lamp voltage Vx detected by the lamp voltage detection circuit 12 is Vx> V0 + ΔV, and if No, the process returns to S14. If yes, S1
6, the frequency f1 when Vx> V0 + ΔV
Is recorded, and the output frequency fL is set to fL = f in S17.
It moves to the point of 1 + Δf and lights up at fL = f1 + Δf.

If Yes in S13, that is, in the low output mode for extracting the frequency near the upper end of the non-resonant frequency band, in S18, the output frequency fH is changed from the initial frequency f0 to the lamp voltage Vx where Vx> V0 + ΔV. Rise to the point. The lamp voltage Vx detected by the lamp voltage detection circuit 12 in S19 is Vx>
It is determined whether or not V0 + ΔV, and if No, the process returns to S18. If Yes, in S20, Vx> V0 + ΔV
The frequency f2 at the time of becomes f is recorded, and in S21, the output frequency fH is moved to a point where fH = f2-Δf, and f
It lights at a frequency of H = f2-Δf. Then, in S22, after a predetermined interval, the process returns to S12 and the above operation is repeated.

FIG. 6 shows the relationship between the lighting frequency and the lamp voltage in the above operation. The horizontal axis represents the lighting frequency, and the vertical axis represents the lamp voltage. As shown in FIG. 6, depending on the switching information of the rated lighting mode or the low output mode in the output mode switching circuit 13, the lighting is performed while keeping a constant frequency width Δf with the lower end side or the upper end side of the non-resonant frequency band. Will be done.

As described above, according to the switching information in the output mode switching circuit, the frequency is moved at the lower end or the upper end of the non-resonance frequency band to extract an appropriate output frequency that avoids the acoustic resonance frequency band. Therefore, as in the first embodiment, it is possible to reliably prevent flickering and disappearance due to the acoustic resonance phenomenon, and it is possible to reduce the frequency shift width and minimize the change in the optical output due to the frequency shift. it can. Further, for example, the step-dimming operation can be performed using the frequency near the lower end and the frequency near the upper end of the non-resonant frequency band.

Embodiment 3. FIG. 7 is a circuit configuration block diagram of the high pressure discharge lamp lighting device according to the third embodiment. In FIG. 7, parts that are the same as or correspond to those in FIG. 1 of Embodiment 1 above are assigned the same reference numerals and explanations thereof are omitted.
In FIG. 7, 14 is a load current detection circuit that detects the load current flowing through the lamp 10, and 15 is a load current detection resistor.

In the present embodiment, the frequency control circuit 11 fetches the detection value of the load current detection circuit 14 and varies the value of Δf based on the detection value to feed back the load current. , Is designed to keep the brightness constant.

Next, the operation of the high pressure discharge lamp lighting device configured as described above will be described. FIG. 8 shows a flowchart of a method of determining the output frequency in the frequency control circuit 11. First, in S21, the control circuit 5 starts the lighting by outputting the output frequency fL to the inverter circuit 2 as an initial frequency of, for example, the frequency fL = f0 that will be included in the non-resonant frequency band. In S22, the initial frequency f0
The lamp voltage V0 detected by the lamp voltage detection circuit 12 and the load current i0 detected by the load current detection circuit 14 are recorded. Next, in S23, the output frequency fL is changed from the initial frequency f0 to the lamp voltage Vx.
Falls to the point where Vx> V0 + ΔV. And S
At 24, it is determined whether or not the lamp voltage Vx detected by the lamp voltage detection circuit 12 is Vx> V0 + ΔV. If No, the process returns to S23. If Yes, S
Frequency f when Vx> V0 + ΔV at 25
Record 1. Next, in S26, the load current i0 recorded in S22 is compared with the target value i1, and the value of Δf is calculated according to the difference, for example, Δf = a × (i0-i1) +
Determine to be b. In addition, a and b are constants. Then, in S27, the output frequency fL is set to fL = f1 +
It moves to a point where Δf is reached, and lights at a frequency of fL = f1 + Δf.

Therefore, when the load current i0 is small, the frequency width Δf is reduced, and the frequency fL is lowered to increase the lamp current. When the load current i0 is large, Δf is increased to increase the frequency fL. By controlling so that the lamp current is reduced by increasing it, the lamp current is maintained at a predetermined value and the brightness is kept constant. And S28
After a predetermined interval has been set, the process returns to S22 and the above operation is repeated.

As described above, since the current detection circuit for detecting the current flowing through the lamp makes Δf variable based on the detected current and feeds back the load current, the acoustic resonance phenomenon can be avoided. It is possible to prevent the fluctuation of the optical output due to the movement of the frequency and to keep the brightness constant.

Although a predetermined interval is provided in the output frequency determining operation flow of the first to third embodiments, the operation may be continuously performed without providing the interval.

[0037]

As described above, the high pressure discharge lamp lighting device according to the first aspect of the present invention comprises a high pressure discharge lamp, an inverter circuit for supplying the high pressure discharge lamp with AC power of 1 KHz or more,
A high pressure discharge lamp lighting device comprising a control circuit for controlling an output frequency of the inverter circuit, wherein the control circuit detects an upper end frequency or a lower end frequency of one non-resonant frequency band, and the upper end frequency or the lower end frequency. Since the output frequency is selected to be one frequency in the non-resonance frequency band calculated from the output frequency that avoids the acoustic resonance frequency band, it is possible to reliably avoid flickering and disappearance due to the acoustic resonance phenomenon. You can

The high pressure discharge lamp lighting device according to claim 2 is
High-pressure discharge lamp, an inverter circuit that supplies alternating-current power of 1 KHz or more to the high-pressure discharge lamp, a control circuit that controls the output frequency of the inverter circuit, and a discharge lamp voltage detection that detects the voltage across the high-pressure discharge lamp. A high pressure discharge lamp lighting device comprising a circuit, at least starting lighting at a predetermined initial output frequency of the non-resonance frequency band, of the high pressure discharge lamp detected by the discharge lamp voltage detection circuit at the initial output frequency The discharge lamp voltage is recorded, and when the output frequency is increased or decreased by the control circuit, the frequency at which the discharge lamp voltage becomes higher than the recorded discharge lamp voltage by a predetermined value is recorded. The output frequency is moved to the center side of the non-resonance frequency band from the specified frequency by a predetermined frequency Δf so that the output frequency avoids the acoustic resonance frequency band. Since, it is possible to reliably avoid the flicker and the fading due to acoustic resonance phenomenon. In addition, the frequency shift width can be reduced, and the change in optical output due to the frequency shift can be minimized.

The high pressure discharge lamp lighting device according to claim 3 is
The control circuit detects a lower end frequency of the non-resonant frequency band and outputs a frequency higher than the lower end frequency by a predetermined frequency Δf, and detects an upper end frequency of the non-resonant frequency band, and determines a predetermined value from the upper end frequency. Since the control for outputting the frequency lower by the frequency Δf can be switched, it is possible to reliably avoid the acoustic resonance phenomenon even during the transitional period at the start of lighting.

The high pressure discharge lamp lighting device according to claim 4 is
An output mode switching circuit for switching between a high output mode and a low output mode is provided, and in the high output mode,
The control circuit detects the lower end frequency of the non-resonant frequency band, outputs a frequency higher than the lower end frequency by a predetermined frequency Δf, and detects the upper end frequency of the non-resonant frequency band during the low output mode, Since the output frequency is lower than the upper end frequency by the predetermined frequency Δf, the output can be switched using the upper end frequency or the lower end frequency of the non-resonant frequency band with a simple structure, and the acoustic resonance phenomenon can be avoided. You can

The high pressure discharge lamp lighting device according to claim 5 is
Since the current detection circuit for detecting the current flowing through the high pressure discharge lamp is provided, the value of Δf is made variable based on the detected current, and the control circuit feeds back the current flowing through the high pressure discharge lamp. The acoustic resonance phenomenon can be avoided and the current flowing through the high pressure discharge lamp can be kept at a predetermined value, that is, the brightness can be kept constant, and it is not necessary to provide a separate output adjusting means, and the device can be made compact. Can be converted.

The high pressure discharge lamp lighting device according to claim 6 is:
Since the control circuit is configured to continuously or repeatedly move the output frequency at predetermined intervals, it is possible to reliably avoid the acoustic resonance phenomenon even when the non-resonant frequency band moves due to a change with time of the high pressure discharge lamp or the like.

[Brief description of drawings]

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

FIG. 2 is a flowchart diagram according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a lighting frequency and a lamp voltage according to the first embodiment of the present invention.

FIG. 4 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 5 is a flow chart according to the second embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a lighting frequency and a lamp voltage according to the second embodiment of the present invention.

FIG. 7 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to a third embodiment of the present invention.

FIG. 8 is a flowchart diagram according to the third embodiment of the present invention.

FIG. 9 is a circuit configuration block diagram of a conventional high pressure discharge lamp lighting device.

FIG. 10 is a diagram showing a relationship between a lamp voltage and an acoustic resonance phenomenon occurrence with respect to a lighting frequency.

[Explanation of symbols]

1 DC power supply, 2 inverter circuit, 5 control circuit, 6 load circuit, 10 high pressure discharge lamp, 11 frequency control circuit, 12 lamp voltage detection circuit, 13 output mode switching circuit, 14 load current detection circuit, 15
resistance.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3K072 AA01 AC11 BA03 CA03 CA07                       DD03 DE02 DE04 GB12 GC04                       HA06                 3K098 CC22 CC43 CC58 DD09 DD22                       DD37 DD43 EE11 EE12 EE14                       EE40 FF03 FF04

Claims (6)

[Claims] 1. A high pressure discharge lamp and 1 KH for the high pressure discharge lamp.
What is claimed is: 1. A high pressure discharge lamp lighting device, comprising: an inverter circuit for supplying AC power of z or more; and a control circuit for controlling an output frequency of the inverter circuit, wherein the control circuit is an upper end frequency of one non-resonant frequency band or A high pressure discharge lamp lighting device, which detects a lower end frequency and selects an output frequency as one frequency in the resonance frequency band calculated from the upper end frequency or the lower end frequency. 2. A high pressure discharge lamp and 1 KH for the high pressure discharge lamp.
High pressure discharge lamp lighting device including an inverter circuit for supplying AC power of z or more, a control circuit for controlling an output frequency of the inverter circuit, and a discharge lamp voltage detection circuit for detecting a voltage across the high pressure discharge lamp. It is to start lighting at a predetermined initial output frequency included in at least the non-resonance frequency band, and record the discharge lamp voltage of the high-pressure discharge lamp detected by the discharge lamp voltage detection circuit at the initial output frequency, When the output frequency is increased or decreased by the control circuit, the frequency at which the discharge lamp voltage becomes higher than the recorded discharge lamp voltage by a predetermined value is recorded, and the control circuit records the frequency by a predetermined frequency Δf from the recorded frequency. A high pressure discharge lamp lighting device characterized in that the output frequency is moved only to the center side of the non-resonant frequency band. 3. The control circuit detects the lower end frequency of the non-resonant frequency band and outputs a frequency higher than the lower end frequency by a predetermined frequency Δf, and detects the upper end frequency of the non-resonant frequency band. , A predetermined frequency Δf from the upper end frequency
3. The high pressure discharge lamp lighting device according to claim 2, wherein control for outputting a frequency that is low by a certain amount can be switched. 4. An output mode switching circuit for switching between a high output mode and a low output mode, wherein during the high output mode, the control circuit detects a lower end frequency of a non-resonant frequency band, and the lower end is detected. Predetermined frequency Δf from frequency
4. The high frequency is output, and in the low output mode, the upper end frequency of the non-resonant frequency band is detected, and the frequency lower than the upper end frequency by a predetermined frequency Δf is output. High pressure discharge lamp lighting device. 5. A current detection circuit for detecting a current flowing through the high pressure discharge lamp is provided, the value of Δf is made variable based on the detected current, and the control circuit feeds back the current flowing through the high pressure discharge lamp. The high pressure discharge lamp lighting device according to any one of claims 2 to 4, wherein. 6. The high pressure discharge lamp lighting device according to claim 1, wherein the control circuit continuously or repeatedly shifts the output frequency at predetermined intervals.