JP2003282286A - High pressure discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure discharge lamp lighting device preventing flickering and fading out in a period from the start of the lighting to reaching a stabilized lighting in the high frequency lighting of the high pressure discharge lamp. <P>SOLUTION: This high pressure discharge lamp lighting device is provided with the high pressure discharge lamp, an inverter circuit feeding an ac power of 1 kHz or more to the high pressure discharge lamp, and a control circuit controlling an output frequency of the inverter circuit. The control circuit changes the output frequency in the same nonresonant frequency band or, at least, two or more different nonresonant frequency bands in a period from starting the lighting to reaching the steady lighting of the high pressure discharge lamp. <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 high frequency lighting of a high pressure discharge lamp lighting device.

[0002]

2. Description of the Related Art FIG. 7 is a circuit block diagram of a conventional high pressure discharge lamp lighting device. In FIG. 7, 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 turned ON / O at a frequency of, for example, several tens of kHz from the control circuit 5.
FF control is performed to convert the output from the DC power supply 1 into a high frequency. The power converted to high frequency is 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 includes a lamp 10
A high voltage of several kV is applied for dielectric breakdown between the electrodes before the discharge starts, but the electrodes are disconnected after the discharge starts.

Further, when a high-pressure discharge lamp is lit at a high frequency, 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, causing a so-called acoustic resonance phenomenon which causes extinction and lamp destruction. It is known to be easy. 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: pipe 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 the frequency fr.

However, from the start of lighting to the stable lighting, the discharge arc may become unstable even within the non-resonant frequency band. The cause is that several kinds of discharge substances in the arc tube are sequentially vaporized, and the average molecular weight M in the tube is changed in the process, the sound velocity v is changed, and the non-resonance frequency band is also changed accordingly. It is thought that it is doing. That is, the vicinity of the center of the non-resonant frequency band at the time of stable lighting does not always become the non-resonant frequency band for several minutes from the start of lighting to the time when stable lighting is reached. As a result, an acoustic resonance phenomenon occurs for a few minutes until the stable lighting is reached, which causes flickering due to the swing of the discharge arc, and may cause extinction when the swing of the arc becomes large.

FIG. 8 shows that when a ceramic arc tube having a rated power of 35 W is actually used for lighting in a non-resonant frequency band near 40 to 45 kHz, the lamp voltage from the start of lighting when the lighting is performed at a frequency near the center of the lamp. FIG. 6 is a diagram that schematically represents changes in illuminance. The upper part of the vertical axis in the figure shows the lamp voltage, the lower part shows the illuminance, and the horizontal axis shows the time. In the figure, t1 shows the time when the discharge state changes, and t2 shows the time when stable lighting is reached. The times t1 and t2 have unique values depending on the constituent substances in the lamp. As shown in FIG. 8, vibration of illuminance (portion indicated by thick line and vertical line in the figure), that is, flicker, occurs near the rising t1. The illuminance here means the brightness seen from a certain point. Also, FIGS.
In addition, the lower limit of the non-resonant frequency band 40 to 45 kHz (40
FIG. 5 is a diagram simulating changes in the lamp voltage and illuminance from the start of lighting when lighting is performed at a frequency of (kHz) or an upper limit (45 kHz). Similar to FIG. 8, the vertical axis shows the lamp voltage, the lower axis shows the illuminance, and the horizontal axis shows the time. Incidentally, t1 and t2 in the figure are as described above. As shown in FIGS. 9 and 10, flicker (a portion indicated by a thick line and a vertical line in the figure) frequently occurs in a predetermined period before and after the time t1 when the discharge state changes. Therefore, if the light is turned on at a fixed frequency, flicker will occur for a certain period of time during one of the rising periods.

Therefore, in order to avoid the above problems,
A circuit block configuration shown in FIG. 11 disclosed in JP-A-60-148084 has been proposed. In addition, in FIG.
The same or corresponding parts as those in FIG. 7 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 11, 14 is a low frequency output means of a direct current or commercial frequency, 15 is a high frequency output means by an inverter, 16 is a lighting state detection means for detecting the lighting state of the lamp 10, and 17 is the low frequency output means 14. It is a relay that switches the output from the high frequency output means 15.
The low frequency output means 1 for the lamp 10 is generated by the relay 17 based on the signal from the lighting state detection means 16.
4 or the power is supplied by switching to the high frequency output means 15. After the lighting of the lamp 10 is started, the relay 17 is connected to the low frequency output means 14 side to perform lighting at a low frequency until the lighting state detection means 16 determines that the lamp 10 has reached stable lighting. Then, after the lighting state detection means 16 detects that stable lighting has been reached, the relay 17 is connected to the high frequency output means 15 side to perform high frequency lighting. Since the acoustic resonance phenomenon does not occur at low frequency lighting, the flicker and the disappearance due to the phenomenon occurring at the time of rising are avoided in this way.

[0008]

However, in the circuit block configuration as described above, it is possible to avoid flickering and the like due to the acoustic resonance phenomenon at the time of rising.
In addition to the high-frequency output means, a low-frequency output means and a relay circuit for switching the output means must be provided, which causes a problem that the circuit configuration becomes large and eventually the cost increases.

The present invention has been made in order to solve the above-mentioned problems. In the high-frequency lighting of the high-pressure discharge lamp, stable lighting is started from the lighting start without providing an output means other than the high-frequency output means. An object of the present invention is to obtain a high pressure discharge lamp lighting device capable of preventing flickering and extinguishing in a period until reaching.

[0010]

A high pressure discharge lamp lighting device according to claim 1 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 the inverter circuit. And a control circuit for controlling the output frequency of the high pressure discharge lamp, wherein the control circuit is in the same non-resonance frequency band or at least two in the period from the start of lighting of the high pressure discharge lamp to the stable lighting. The output frequency is changed over the different non-resonant frequency bands.

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 an output frequency of the inverter circuit. A high-pressure discharge lamp lighting device comprising, in the case where the control circuit sets the output frequency to an arbitrary point within the non-resonant frequency band in a period from the lighting start of the high-pressure discharge lamp to stable lighting.
The output frequency is made different in the first period from the start of lighting of the high-pressure discharge lamp and the second period from the end of the first period to reaching stable lighting.

The high pressure discharge lamp lighting device according to a third aspect of the present invention is such that the output frequency of the first period is lower than the output frequency of the second period.

A high pressure discharge lamp lighting device according to a fourth aspect of the present invention includes a voltage detection circuit for detecting the voltage across the high pressure discharge lamp, and the amplitude of the voltage fluctuation of the high pressure discharge lamp detected by the voltage detection circuit. When the value exceeds a predetermined value, the first period is ended.

A high pressure discharge lamp lighting device according to a fifth aspect of the present invention includes a voltage detection circuit for detecting a voltage across the high pressure discharge lamp, and a voltage across the high pressure discharge lamp detected by the voltage detection circuit is detected. When the voltage exceeds a predetermined value, the first period is ended, and when the voltage across both ends is not changed, the second period is ended.
The period of is ended.

A high pressure discharge lamp lighting device according to a sixth aspect of the present invention includes a timer, and the first period or the first period after a predetermined time has elapsed from the start of lighting of the high pressure discharge lamp based on time information by the timer. The second period is ended.

A high pressure discharge lamp lighting device according to a seventh aspect of the present invention includes a non-volatile memory, stores the voltage across the high pressure discharge lamp immediately before extinguishing the lamp last time, and at the next lighting, a predetermined voltage for the stored voltage across the high voltage discharge lamp is stored. The ratio voltage is set as a new predetermined value, and the first period is ended when the voltage exceeds the predetermined value, and the second period is ended when there is no change in the both-end voltage.

[0017]

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. 1, FIG.
The same or corresponding parts are designated by the same reference numerals and the description thereof will be omitted. In FIG. 1, 11 is a frequency switching control circuit for switching the output frequency, 12 is a lamp voltage detection circuit for detecting, for example, an effective value of the voltage of the lamp 10, and 13 is a timer.

Next, the operation of the high pressure discharge lamp lighting device configured as described above will be described. First, at the start of lighting,
The control circuit 5 outputs a relatively low frequency f1 in the non-resonant frequency band based on the signal from the frequency switching control circuit 11. The lamp voltage detection circuit 12 detects the lamp voltage of the lamp 10 and inputs the detected value to the frequency switching control circuit 11. The frequency switching control circuit 11 calculates the amplitude of the voltage fluctuation based on the detected value of the input lamp voltage, and when the calculated amplitude exceeds a predetermined value, the frequency switching control circuit 11 relatively moves within the non-resonant frequency band. The frequency is switched to the higher frequency f2, and the control circuit 5 outputs the frequency f2 based on the signal. It is known that the fluctuation of the lamp voltage does not occur when there is no flicker, but when the flicker occurs, the lamp voltage also fluctuates in the same manner as the illuminance. After switching from the low frequency f1 to the high frequency f2, the elapsed time is counted by the timer 13, and when the predetermined time Ta elapses, the lighting at the frequency f2 is ended and the control is switched to the stable lighting control.

FIG. 2 is a diagram schematically showing changes in the lamp voltage, the illuminance and the lighting frequency in the elapsed time from the start of lighting. The upper side of the vertical axis is the lamp voltage, the middle side is the illuminance,
The lower side shows the lighting frequency, and the horizontal axis is time. In the figure, t1 is the time when the discharge state changes, and t2 is the time when stable lighting is reached. As described above, these times t1 and t2.
Has a unique value depending on the constituent materials in the lamp. Since it starts at a low frequency f1 at the start of lighting,
Up to t1 in FIG. 2, the flicker phenomenon does not occur as in FIG. 9 of the conventional example. If the lamp continues to be lit at the frequency f1 as it is, the flicker phenomenon occurs in the time period after t1 as shown in FIG. 9, but the lamp voltage detection circuit 12 causes the lamp to start flicker after t1. When the voltage is detected and the amplitude of the voltage fluctuation calculated by the frequency switching control circuit 11 based on the detected information is equal to or larger than a predetermined value, the frequency is switched to the higher frequency f2.

In order to switch to the frequency f2 based on the detection information after detecting the lamp voltage, the time difference Δt between the time t1 and the time to switch to the frequency f2.
However, since Δt is very short, even if flicker occurs, it is short enough not to give the user a feeling of strangeness.

After switching from the frequency f1 to the frequency f2, the same condition as that after t1 in FIG. 10 is obtained, and the flicker phenomenon does not occur. Further, since the time required to reach stable lighting is several tens of seconds, the elapsed time after switching is counted by the timer 13 and the lighting at the frequency f2 is finished after the predetermined time Ta shown in FIG. Control.

Although t2 and the frequency f2 do not always match at the end, the flicker or the like caused by this deviation does not occur because the frequency and the time zone do not cause the acoustic resonance phenomenon.

As described above, the lighting frequency is switched from the relatively low frequency f1 in the non-resonance frequency band to the high frequency f2 based on the lamp voltage detection information by the lamp voltage detection circuit at the start of the lamp lighting, and the timer is used. Since the control is switched to stable lighting after a lapse of a predetermined time after switching the frequency f2 to avoid the acoustic resonance phenomenon, flicker and extinction in the period from the start of lighting to the stable lighting are avoided. can do.

Further, in the above-described embodiment, the frequency switching control is performed by setting the predetermined value (threshold value) for the amplitude of the lamp voltage fluctuation. Therefore, when the lamp is turned on due to variations in lamp characteristics or differences in lamp manufacturers. Even if the time t1 in which the discharge state changes is varied, the frequency can be reliably switched and flicker can be avoided.

In the above embodiment, the elapsed time after switching from the frequency f1 to f2 by the timer 13 is counted, the lighting at the frequency f2 is finished after a predetermined time Ta, and the control is shifted to stable lighting. However, the elapsed time from the start of lighting the lamp is counted,
For example, after the elapse of the predetermined time Tb, the lamp voltage detection circuit 1
The control for stable lighting may be performed regardless of the detected value of the lamp voltage of 2. That is, depending on the lamp, there is a case where the lamp voltage does not fluctuate due to the acoustic resonance phenomenon. In that case, the control is shifted to stable lighting control after a predetermined time has elapsed from the start of lamp lighting.

In the above embodiment, the frequency f1 is switched to the frequency f2 based on the lamp voltage detection information. However, the present invention is not limited to this. Originally frequency f1
May be switched to the frequency f2.

Embodiment 2. FIG. 3 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to Embodiment 2 of the present invention. In FIG. 3, parts that are the same as or correspond to those in FIG. 1 of Embodiment 1 above are given the same reference numerals and description thereof is omitted. In the first embodiment, the frequency f1 is switched to the frequency f2 based on the lamp voltage detection information by the lamp voltage detection circuit 12 at the start of the lamp lighting, and the stable lighting is performed after a predetermined time has elapsed after the frequency f2 is switched by the timer 13. However, in the present embodiment, only the lamp voltage detection circuit 12 is used to perform switching from the frequency switching to the control switching for stable lighting based on the lamp voltage detection information. It was done. It should be noted that in the present embodiment, the selection of the frequencies f1 and f2 at the start of lamp lighting, and the times t1 and t
The definition of 2 is the same as that of the first embodiment.

Next, the operation will be described. At the start of lighting, the frequency switching control circuit 11 starts at the frequency f1, and when the lamp voltage of the lamp 10 detected by the lamp voltage detection circuit 12 exceeds a predetermined value V1, the frequency f1 is switched to f2. When the lamp voltage does not change after switching to f2, that is, when the flat state is detected, it is assumed that the stable lighting is reached, and thereafter, the control for the stable lighting is performed.

FIG. 4 is a diagram schematically showing changes in the lamp voltage, the illuminance and the lighting frequency in the elapsed time from the start of lighting the lamp. The upper side of the vertical axis shows the lamp voltage, the middle side shows the illuminance, the lower side shows the lighting frequency, and the horizontal axis shows the time. The lighting is started at the frequency f1, and if the lighting is continued at the frequency f1 as it is, it is t1 as shown in FIG.
Flickering occurs in the time period after, but if the voltage of the lamp 10 detected by the lamp voltage detection circuit 12 exceeds a predetermined value V1 shown in FIG. 4 (time t1 in the figure).
And the frequency f1 is switched to f2. Frequency f2
After switching to, as a result, the same conditions as after t1 shown in FIG. 10 are obtained, so that flicker does not occur. And f
When there is no change in the lamp voltage detected by the lamp voltage detection circuit 12 after switching to 2, it is considered that stable lighting has been reached at that time (near time t2 in the figure), and then control for stable lighting is performed.

As shown in FIG. 4, the time when the lamp voltage exceeds the predetermined value V1 and t1 do not always coincide with each other in reality, but they substantially coincide with each other. for example,
Even if there is a slight deviation between the time when the lamp voltage exceeds V1 and t1, the time when the acoustic resonance phenomenon occurs and the flicker occurs is short enough not to make the user feel uncomfortable.

As described above, in the present embodiment,
When the lamp voltage rises, the frequency f1 is switched to f2 when the lamp voltage exceeds a predetermined value based on the lamp voltage detection information by the lamp voltage detection circuit, and when the lamp voltage no longer changes, stable lighting is reached. Since the control for stable lighting is performed thereafter, it is possible to avoid flickering and extinguishing due to the acoustic resonance phenomenon at the time of start-up by simple control based on the lamp voltage detection information.

In the above embodiment, the predetermined value V1 of the lamp voltage is set to a fixed value. However, since the lamp voltage generally rises as the lamp ages, the predetermined value V1
Instead of a fixed value, for example, the frequency switching control circuit 11 is provided with a non-volatile memory to store the lamp voltage (for example, V2) at the time of the previous extinction, and V1 at the start of the next lighting is set to the stored lamp voltage. It is calculated based on V2. For example, V1 may be set to a value that is a predetermined ratio with respect to the lamp voltage V2.

In the above embodiment, the frequency is switched based on the lamp voltage detection information. However, the present invention is not limited to this, and the frequency is switched based on the detection information such as lamp current and illuminance. May be switched.

Embodiment 3. FIG. 5 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to Embodiment 3 of the present invention. In FIG. 5, parts that are the same as or correspond to those in FIG. 1 of Embodiment 1 above are given the same reference numerals and description thereof is omitted. In the second embodiment, the switching of the frequency at the start of lighting to the control shift for stable lighting is performed based on the lamp voltage detection information by the lamp voltage detection circuit 12. However, in the present embodiment, By using only the timer, the switching of the frequency to the control transition for stable lighting is performed based on the timing information from the start of lighting. In the present embodiment, the frequency f1
The selection of f and f2 and the definition of times t1 and t2 are the same as those in the first embodiment.

Next, the operation will be described. At the start of lighting, the frequency switching control circuit 11 starts at the frequency f1, and the timer 13 switches from the frequency f1 to the frequency f2 when a first predetermined time has elapsed from the start of lighting, based on the timing information from the start of lighting. The control for stable lighting is performed after the second predetermined time has elapsed.

FIG. 6 is a diagram schematically showing changes in the lamp voltage, the illuminance and the lighting frequency in the elapsed time from the start of lighting. The upper side of the vertical axis is the lamp voltage, the middle side is the illuminance,
The lower side shows the lighting frequency, and the horizontal axis is time. In the figure, t11 is, for example, the first predetermined time from the start of lighting that is the estimated time of t1 when the discharge state changes, and t12 is the second predetermined time that is the estimated time of t2 that reaches stable lighting, for example. Are shown respectively. The lighting starts at the frequency f1, and if the lighting continues at the frequency f1 as it is,
As shown in FIG. 9 of the above-mentioned conventional example, flicker occurs in a time zone after t1, but when the first predetermined time t11 (time t1 in the figure) has elapsed from the start of lighting by the timer 13, the frequency f2 is switched to. To do so. After the frequency f2 is switched, as a result, as shown in FIG.
Flicker does not occur because the condition is the same as that after t1 shown in FIG. Then, when the second predetermined time t12 (time t2 in the drawing) further elapses, control for stable lighting is performed.

The first predetermined times t11 and t1 or the second predetermined times t12 and t2 do not necessarily coincide with each other in reality, but the first predetermined time t11 is not necessarily the same.
Since the second predetermined time t12 and the second predetermined time t12 can be set to the above t1 and t2, respectively, within a certain error range,
Even if there is some deviation, the time for which an acoustic resonance phenomenon occurs and flicker occurs is short enough not to make the user feel uncomfortable.

As described above, in the present embodiment, when the lamp is turned on, the frequency f1 is reached when the first predetermined time has elapsed from the start of lighting based on the timing information of the timer.
Since the control is switched to stable lighting after the second predetermined time elapses, it is possible to avoid flickering and disappearance due to the acoustic resonance phenomenon at startup with a simple circuit configuration using a timer. You can

In the first to third embodiments, the frequencies f1 and f2 are frequencies belonging to the same non-resonant frequency band. However, for example, when the lamp has a plurality of non-resonant frequency bands, they are different. The frequencies f1 and f2 may be set using a non-resonant frequency band.

In the first to third embodiments, the lighting frequency after the stable lighting is reached may be any frequency as long as it does not cause the acoustic resonance phenomenon.

[0041]

As described above, the high pressure discharge lamp lighting device according to claim 1 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 is within the same non-resonant frequency band in a period from the start of lighting of the high-pressure discharge lamp to stable lighting. Since the output frequency is set and changed in accordance with the discharge state at the start of lighting, it can be changed over at least two or more different non-resonant frequency bands. A high pressure discharge lamp lighting device capable of preventing flickering and extinction due to an acoustic resonance phenomenon can be obtained.

The high pressure discharge lamp lighting device according to claim 2 is
A high pressure discharge lamp lighting device comprising: a high pressure discharge lamp; an inverter circuit that supplies alternating current power of 1 kHz or higher to the high pressure discharge lamp; and a control circuit that controls an output frequency of the inverter circuit. When the output frequency is set to an arbitrary point within the non-resonance frequency band in the period from the start of lighting of the high pressure discharge lamp to the stable lighting, a first period from the start of lighting of the high pressure discharge lamp, and With the second period from the end of period 1 to reaching stable lighting,
Since the output frequencies are appropriately different according to the discharge state at the start of lighting, the flicker and extinguishing due to the acoustic resonance phenomenon during the period from the start of lighting to the stable lighting can be prevented as in the above-mentioned claim 1. A discharge lamp lighting device is obtained.

The high pressure discharge lamp lighting device according to claim 3 is
Since the output frequency in the first period is set to be lower than the output frequency in the second period, it is possible to reliably prevent flickering at the time of lighting start.

The high pressure discharge lamp lighting device according to claim 4 is
A voltage detection circuit for detecting the voltage across the high-pressure discharge lamp is provided, and the first period is ended when the amplitude of the voltage fluctuation of the high-pressure discharge lamp detected by the voltage detection circuit exceeds a predetermined value. Since it was set, with a simple circuit configuration,
The frequency switching operation can be performed at an appropriate timing for any high-pressure discharge lamp.

The high pressure discharge lamp lighting device according to claim 5 is:
A voltage detection circuit for detecting the voltage across the high-pressure discharge lamp is provided, and when the voltage across the high-pressure discharge lamp detected by the voltage detection circuit exceeds a predetermined value, the first period ends, and the voltage across the voltage further ends. Since the second period is ended when there is no change in the frequency, the frequency switching operation should be performed without erroneous detection in the period from the start of lighting to the stable lighting of any high pressure discharge lamp. You can

The high pressure discharge lamp lighting device according to claim 6 is
Since a timer is provided and the first period or the second period is terminated after a predetermined time has elapsed from the start of lighting of the high pressure discharge lamp based on the timing information by the timer, a simpler circuit configuration is provided. The frequency switching operation can be performed during the period from the start of lighting to the stable lighting.

The high pressure discharge lamp lighting device according to claim 7 is
A non-volatile memory is provided, which stores the voltage across the high-pressure discharge lamp immediately before being turned off last time, and at the next lighting, a predetermined ratio of the voltage across the stored voltage is set as a new predetermined value. Since the second period is ended when the first period is ended and the voltage across the both ends is no longer changed, it is possible to appropriately cope with the voltage rise of the high pressure discharge lamp due to the aging of the high pressure discharge lamp. A frequency switching operation can be performed.

[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 diagram simulating changes in lamp voltage, illuminance, and lighting frequency in the elapsed time from the start of lighting according to the first embodiment of the present invention.

FIG. 3 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 4 is a diagram simulating changes in lamp voltage, illuminance, and lighting frequency in the elapsed time from the start of lighting according to the second embodiment of the present invention.

FIG. 5 is a circuit configuration block diagram of a high pressure discharge lamp lighting device according to a third embodiment of the present invention.

FIG. 6 is a diagram simulating changes in lamp voltage, illuminance, and lighting frequency in the elapsed time from the start of lighting according to the third embodiment of the present invention.

FIG. 7 is a circuit block diagram of a conventional high pressure discharge lamp lighting device.

FIG. 8: 40-4 using a 35 W ceramic arc tube
It is the figure which simulatedly represented the change of the lamp voltage and illuminance from the lighting start at the time of lighting at the near-center frequency of the non-resonant frequency band near 5 kHz.

FIG. 9 is a diagram simulating changes in lamp voltage and illuminance from the start of lighting when lighting is performed at a lower limit frequency of the non-resonance frequency band.

FIG. 10 is a diagram simulating changes in the lamp voltage and illuminance from the start of lighting when lighting is performed at the upper limit frequency of the non-resonance frequency band.

FIG. 11 is a block circuit diagram of another conventional discharge lamp lighting device.

[Explanation of symbols]

1 DC power supply, 2 inverter circuit, 5 control circuit, 6 load circuit, 10 high pressure discharge lamp, 11 frequency switching control circuit, 12 lamp voltage detection circuit, 13
timer.

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Claims (7)

[Claims] 1. A high pressure discharge lamp and 1 kH for the high pressure discharge lamp.
A high pressure discharge lamp lighting device comprising: an inverter circuit that supplies AC power of z or more; and a control circuit that controls an output frequency of the inverter circuit, the control circuit stably lighting the high pressure discharge lamp from the start of lighting. The high pressure discharge lamp lighting device is characterized in that the output frequency is changed in the same non-resonant frequency band or over at least two or more different non-resonant frequency bands in a period of reaching. 2. 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 that supplies AC power of z or more; and a control circuit that controls an output frequency of the inverter circuit, wherein the control circuit is stable from the start of lighting of the high pressure discharge lamp. When the output frequency is set to an arbitrary point within the non-resonant frequency band during the period when the lighting is reached, the first period from the start of lighting the high pressure discharge lamp and the end of the first period until the stable lighting is reached. The high-pressure discharge lamp lighting device characterized in that the output frequency is different from that in the second period. 3. The high pressure discharge lamp lighting device according to claim 2, wherein the output frequency of the first period is lower than the output frequency of the second period. 4. A voltage detection circuit for detecting the voltage across the high-pressure discharge lamp is provided, and when the amplitude of the voltage fluctuation of the high-pressure discharge lamp detected by the voltage detection circuit exceeds a predetermined value, the first voltage is detected. The high pressure discharge lamp lighting device according to claim 2, wherein the period is ended. 5. A voltage detection circuit for detecting the voltage across the high pressure discharge lamp is provided, and the first period ends when the voltage across the high pressure discharge lamp detected by the voltage detection circuit exceeds a predetermined value. The second period is ended when the voltage across the both ends is no longer changed.
Alternatively, the high pressure discharge lamp lighting device according to item 3. 6. A timer is provided, and the first period or the second period is ended after a lapse of a predetermined time from the start of lighting of the high pressure discharge lamp based on the time information by the timer. Item 2. A high pressure discharge lamp lighting device according to item 2 or 3. 7. A non-volatile memory is provided, which stores the voltage across the high-pressure discharge lamp immediately before being extinguished last time, and at the next lighting, a predetermined ratio of the voltage across the stored voltage is set as a new predetermined value, and the predetermined voltage is set as the new predetermined value. The high pressure discharge lamp lighting device according to claim 2 or 3, wherein the first period is ended when the value exceeds a value, and the second period is ended when the voltage across the both ends does not change.