JPH06163163A - High pressure discharge lamp lighting device - Google Patents

Abstract

PURPOSE:To provide a high pressure discharge lamp lighting device whereby a high pressure discharge lamp, placed in all conditions from that it is a new product to that in the last period of life, can be stably lighted by high frequency without generating an acoustic resonance phenomenon. CONSTITUTION:DC power supplied from a power supply circuit part 1 is converted into high frequency power in an inverter circuit part 2, and the high frequency power is applied to a high pressure discharge lamp 6 lighted by a high frequency. A timer circuit 3 is additionally provided, associated with the power supply circuit part 1, and an oscillating frequency of the inverter circuit part 2 is increased in proportion to an output signal of the timer circuit part 3 increased in proportion to a power supply closing time ( lighting time of high pressure discharge lamp). In this way, the oscillating frequency of the inverter circuit part 2 can be held always to a condition higher than a maximum frequency where generated an acoustic resonance phenomenon in the high pressure discharge lamp 6.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art FIG. 10 shows a block diagram of a conventional high pressure discharge lamp lighting device. As shown in FIG. 10, this high-pressure discharge lamp lighting device converts the direct-current power supplied from the power supply circuit unit 1 into high-frequency power in the inverter circuit unit 2 and supplies the high-frequency discharge lamp 6 with the high-pressure discharge lamp 6 to generate a high-pressure discharge lamp. 6 is lit at high frequency. At this time, the lighting frequency f ₁ of the high-pressure discharge lamp 6 is set to a value exceeding the highest frequency f _AR that causes the acoustic resonance phenomenon.

As is well known, when a high pressure discharge lamp is lit at a high frequency, an acoustic resonance phenomenon occurs, and its frequency band varies depending on the type and shape of the discharge lamp.
The range is approximately several kHz to several hundreds kHz. Therefore,
Stable lighting of the high-pressure discharge lamp can be realized by setting the lighting frequency f ₁ to a certain frequency or higher according to the target high-pressure discharge lamp, but with the present technology, the circuit efficiency increases as the lighting frequency increases. F ₁ >
If the f _AR a and f ₁ ≒ f _AR is common.

[0004]

In the above conventional example, f
_{Although 1} > f _AR and f ₁ ≈f _AR , recent research has shown that the highest frequency f _{AR at which} the acoustic resonance phenomenon occurs tends to increase as the lighting time of the high-pressure discharge lamp increases. It becomes clear that there is a problem that an acoustic resonance phenomenon occurs as the lighting time of the high pressure discharge lamp increases.

An object of the present invention is to solve the above problems and to stably turn on a high-frequency discharge lamp at a high frequency without causing an acoustic resonance phenomenon in all states from a new state to the end of life. It is to provide a high pressure discharge lamp lighting device capable of performing the above.

[0006]

A high pressure discharge lamp lighting device for lighting a high pressure discharge lamp at high frequency according to claim 1, wherein the high pressure discharge lamp generates a sound resonance phenomenon by detecting a lighting time of the high pressure discharge lamp. A control means is provided for increasing the lighting frequency of the high pressure discharge lamp in accordance with the increase of the lighting time so that the highest frequency is always lower than the lighting frequency of the high pressure discharge lamp.

A high pressure discharge lamp lighting device according to a second aspect of the present invention is the high pressure discharge lamp lighting device according to the first aspect, wherein the lamp characteristic that changes according to an increase in the lighting time of the high pressure discharge lamp is replaced with the lighting time of the high pressure discharge lamp. I try to detect it.
The high-pressure discharge lamp lighting device according to claim 3 is for high-frequency discharge lighting of the high-pressure discharge lamp, and the highest frequency at which the high-pressure discharge lamp causes an acoustic resonance phenomenon by detecting the lighting time of the high-pressure discharge lamp is always the high-pressure discharge lamp. The control means is provided to change the physical state of the high-pressure discharge lamp in accordance with the increase of the lighting time so as to be less than the lighting frequency, and to suppress the maximum frequency increase that causes the acoustic resonance phenomenon of the high-pressure discharge lamp.

In the high pressure discharge lamp lighting device according to a fourth aspect of the present invention, the physical state of the high pressure discharge lamp in the high pressure discharge lamp lighting device according to the third aspect is the electric power supplied to the high pressure discharge lamp, and the control means controls the lighting time. The power supplied to the high-pressure discharge lamp is reduced according to the increase. In the high pressure discharge lamp lighting device according to claim 5, the physical state of the high pressure discharge lamp in the high pressure discharge lamp lighting device according to claim 3 is the lamp voltage of the high pressure discharge lamp, and the steady lighting state of the high pressure discharge lamp by the control means. The lamp voltage at is controlled to be constant.

[0009]

According to the structure of the first aspect, the lighting frequency of the high-pressure discharge lamp rises as the lighting time of the high-pressure discharge lamp increases, and the high-frequency discharge lamp has the highest frequency at which an acoustic resonance phenomenon occurs. Can always be less than the lighting frequency of the high-pressure discharge lamp. According to the configuration of claim 2, the lighting frequency of the high-pressure discharge lamp increases in accordance with the change in the lamp characteristics that changes in accordance with the increase in the lighting time of the high-pressure discharge lamp, and the high-pressure discharge lamp causes acoustic resonance. The highest frequency that causes a phenomenon can always be less than the lighting frequency of the high-pressure discharge lamp.

According to the third aspect of the present invention, the physical state of the high-pressure discharge lamp changes in accordance with the increase in the lighting time of the high-pressure discharge lamp, and the high-frequency discharge lamp causes the acoustic resonance phenomenon. Therefore, the highest frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon can always be set to be less than the lighting frequency of the high-pressure discharge lamp. According to the configuration of claim 4, the electric power supplied to the high-pressure discharge lamp decreases as the lighting time increases, and the increase in the maximum frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon is suppressed. Therefore, the highest frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon can always be lower than the lighting frequency of the high-pressure discharge lamp.

According to the fifth aspect of the present invention, the lamp voltage in the steady lighting state of the high pressure discharge lamp is controlled to be constant by increasing or decreasing the lamp power, and as a result, the lamp voltage will rise as the lighting time increases. And when
The lamp power will be reduced to suppress it,
As a result, the increase in the maximum frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon is suppressed, and the maximum frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon can always be lower than the lighting frequency of the high-pressure discharge lamp. .

[0012]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a block diagram of a high pressure discharge lamp lighting device according to a first embodiment of the present invention. This high-pressure discharge lamp lighting device is provided with a timer circuit section 3 interlocking with the power supply circuit section 1 as a control means in the configuration of FIG. 10, and increases in proportion to the power-on time (≈high-pressure discharge lamp lighting time). The inverter circuit unit 2 is proportional to the output signal of the timer circuit unit 3.
The oscillation frequency is continuously increased, and other configurations are similar to those of the conventional example of FIG.

By doing so, the oscillation frequency of the inverter circuit section 2, that is, the lighting frequency f ₁ of the high-pressure discharge lamp 6 is always higher than the highest frequency f _{AR at} which the high-pressure discharge lamp 6 causes an acoustic resonance phenomenon. It is possible to keep FIG. 2 shows a specific circuit diagram of the timer circuit unit 3. The timer circuit section 3 is composed of transistors Tr ₁ and Tr ₂ forming a current mirror circuit, a variable resistor VR ₁ , a diode D ₁ , a capacitor C ₁ and an operational amplifier OP ₁ . The timer circuit section 3 has a control power supply voltage V _CC.
A current equivalent to the current I _C1 determined by the variable resistor VR ₁ and the transistor Tr ₁ forming the current mirror circuit,
Through tr ₂ and the diode D _1, flows into the capacitor C _1, the capacitor C ₁ is charged. Then, the output voltage of the operational amplifier OP _{1 which} operates as a voltage follower and to which the voltage of the capacitor C ₁ is applied increases in proportion to the lighting time of the high pressure discharge lamp 6.

In the high pressure discharge lamp lighting device of this embodiment, the oscillation frequency of the inverter circuit section 2 is increased in accordance with the increase in the lighting time of the high pressure discharge lamp 6, so that the lighting frequency f ₁ of the high pressure discharge lamp 6 is increased. Can be maintained at a frequency higher than the highest frequency f _{AR at} which the high-pressure discharge lamp 6 produces an acoustic resonance phenomenon, and the high-pressure discharge lamp 6 can produce an acoustic resonance phenomenon in any state from a new state to the end of life. It is possible to stably turn on the high frequency without generating the light.

[Second Embodiment] FIG. 3 is a block diagram of a high pressure discharge lamp lighting device according to a second embodiment of the present invention. This high-pressure discharge lamp lighting device has the configuration of FIG. 10 and has a lamp voltage (a kind of lamp characteristic) of the high-pressure discharge lamp 6 as a control means.
A lamp voltage detection circuit unit 4 for detecting the voltage is attached, and the oscillation frequency of the inverter circuit unit 2 is continuously increased in proportion to the output signal of the lamp voltage detection circuit unit 4 which rises in proportion to the rise of the lamp voltage. Other configurations are similar to those of the conventional example of FIG.

Increasing the oscillation frequency of the inverter circuit unit 2 in proportion to the rise of the lamp voltage in this manner means that the oscillation frequency of the inverter circuit unit 2 is proportional to the lighting time of the high pressure discharge lamp 6, that is, the high pressure discharge lamp. It is equivalent to increasing the lighting frequency f ₁ of _No. 6 of FIG. That is, this embodiment generally utilizes the characteristic that the lamp voltage of the high-pressure discharge lamp rises in proportion to the lighting time, so that the high-pressure discharge lamp can be directly measured without directly measuring the lighting time. The oscillation frequency of the inverter circuit unit 2 can be increased in proportion to the increase in lighting time.

By doing so, the high-pressure discharge lamp 6
It is possible to always keep the lighting frequency f ₁ of higher than the highest frequency f _{AR at} which the high-pressure discharge lamp 6 causes the acoustic resonance phenomenon. FIG. 4 shows a specific circuit diagram of the lamp voltage detection circuit unit 4. The lamp voltage detection circuit unit 4 detects the lamp voltage appearing across the high-pressure discharge lamp 6 by a resistor R ₁ ,
It is divided by R ₂ , and this divided voltage is divided by diode D ₂ and resistor R ₂ .
It is configured to rectify and smooth by an integrating circuit composed of ₃ , R ₄ and capacitor C ₂ . Therefore,
The output will increase in proportion to the increase in the lamp voltage, that is, in proportion to the increase in the operating time of the high pressure discharge lamp.

In the high pressure discharge lamp lighting device of this embodiment, the oscillation frequency of the inverter circuit section 2 is raised in accordance with the rise of the lamp voltage of the high pressure discharge lamp 6, so the lighting frequency f ₁ of the high pressure discharge lamp 6 is increased. Always high pressure discharge lamp 6
Can maintain a state higher than the highest frequency f _{AR at} which an acoustic resonance phenomenon occurs, and the high-pressure discharge lamp 6 can be stably maintained in all states from a new state to the end of life without causing an acoustic resonance phenomenon. Can be turned on at high frequency.

[Third Embodiment] FIG. 5 is a block diagram of a high pressure discharge lamp lighting device according to a third embodiment of the present invention. This high pressure discharge lamp lighting device is provided with a light output detection circuit section 5 for detecting the light output (a kind of lamp characteristic) of the high pressure discharge lamp 6 as a control means in the configuration of FIG. The oscillation frequency of the inverter circuit unit 2 is continuously increased in proportion to the output signal of the optical output detection circuit unit 5 which rises as a result, and other configurations are similar to those of the conventional example of FIG.

Increasing the oscillating frequency of the inverter circuit unit 2 in response to the decrease in the light output in this manner means that the oscillating frequency of the inverter circuit unit 2 is proportional to the lighting time of the high-pressure discharge lamp 6, that is, the high-pressure discharge lamp. Lighting frequency f _{1 of} 6
Is equivalent to raising. That is, this embodiment generally utilizes the characteristic that the light output of the high-pressure discharge lamp decreases in proportion to the lighting time, so that the lighting time of the high-pressure discharge lamp can be directly measured without directly measuring the lighting time. The oscillation frequency of the inverter circuit unit 2 can be increased in proportion to the increase in lighting time.

By doing so, the high pressure discharge lamp 6
Lighting frequency f₁The high-pressure discharge lamp 6 is always acoustically resonant
The highest frequency f that causes a phenomenon_ARKeep higher
Is possible. FIG. 6 shows a specific circuit of the optical output detection circuit unit 5.
The road map is shown. This optical output detection circuit unit 5 has a control power source V_CC
Resistance R_FiveAnd a series circuit of phototransistor PT
Continuing, connect the phototransistor PT to the high-pressure discharge lamp 6.
The configuration is fixed at a certain distance. This light output detection
In the circuit section 5, the light of the high pressure discharge lamp 6 is a phototransistor.
By irradiating the PT, the light output of the high pressure discharge lamp 6
Proportional collector current I _C2Flows. Therefore, the light output
The collector current I is output to the output of the force detection circuit unit 5._C2Proportional to
Collector voltage V_CWill appear. This collector
Pressure V_CIs proportional to the decrease in the light output of the high pressure discharge lamp 6.
In other words, in proportion to the increase in the lighting time of the high pressure discharge lamp 6,
Will increase.

In the high pressure discharge lamp lighting device of this embodiment, the oscillating frequency of the inverter circuit section 2 is increased in accordance with the decrease in the optical output of the high pressure discharge lamp 6, so the lighting frequency f ₁ of the high pressure discharge lamp 6 is increased. Can be maintained at a frequency higher than the highest frequency f _{AR at} which the high-pressure discharge lamp 6 produces an acoustic resonance phenomenon, and the high-pressure discharge lamp 6 can produce an acoustic resonance phenomenon in any state from a new state to the end of life. It is possible to stably turn on the high frequency without generating the light.

In the first, second and third embodiments, the output signal of the timer circuit unit 3, the output signal of the lamp voltage detection circuit unit 4 or the output signal of the optical output detection circuit unit 5 is proportional to the output signal. Although the oscillation frequency of the inverter circuit unit 2 is continuously increased, the oscillation frequency may be increased stepwise rather than continuously. In short, the oscillation frequency of the inverter circuit unit 2 is always high-voltage discharged. It may be changed so that the lamp 6 can maintain a state higher than the highest frequency f _AR that causes the acoustic resonance phenomenon.

[Fourth Embodiment] FIG. 7 is a block diagram of a high pressure discharge lamp lighting device according to a fourth embodiment of the present invention. This high pressure discharge lamp lighting device is provided with a timer circuit section 7 interlocking with the power supply circuit section 1 as a control means in the configuration of FIG. 10, and increases in proportion to the power-on time (≈high pressure discharge lamp lighting time). The DC output of the power supply circuit unit 1 is reduced in proportion to the output signal of the timer circuit unit 7, and other configurations are the same as those of the conventional example of FIG.

As described above, when the DC output of the power supply circuit section 1 is reduced, the high-voltage discharge lamp 6 is removed from the inverter circuit section 2.
The high frequency power supplied to the lamp, that is, the lamp power (the physical state of the high pressure discharge lamp 6) is reduced. In this way reduce the lamp power, it will be the highest frequency f _AR the acoustic resonance phenomenon occurs decreases, the highest frequency f _AR cause acoustic resonance phenomenon with increasing the lighting time of the high pressure discharge lamp The rise can be suppressed.

As described above, by reducing the DC output of the power supply circuit unit 1, the oscillation frequency of the inverter circuit unit 2, that is, the lighting frequency f ₁ of the high pressure discharge lamp 6 is always caused by the high pressure discharge lamp 6 to cause an acoustic resonance phenomenon. It is possible to keep above the highest frequency f _{AR that} occurs. The specific circuit configuration of the timer circuit unit 7 is the circuit configuration of the timer circuit unit 3 (see FIG.
Since the same as that of the reference), the illustration is omitted.

In the high pressure discharge lamp lighting device of this embodiment, the DC output of the power supply circuit unit 1 is decreased in accordance with the increase of the lighting time of the high pressure discharge lamp 6 to raise the maximum frequency f _AR at which the acoustic resonance phenomenon occurs. Since the lighting frequency f ₁ of the high-pressure discharge lamp 6 can be always kept higher than the highest frequency f _{AR at} which the high-pressure discharge lamp 6 causes an acoustic resonance phenomenon, the high-pressure discharge lamp 6 can be kept in a new state. It is possible to stably turn on the high-frequency light in all states from the state to the end of life without causing an acoustic resonance phenomenon.

[Fifth Embodiment] FIG. 8 shows a block diagram of a high pressure discharge lamp lighting device according to a fifth embodiment of the present invention. This high-pressure discharge lamp lighting device is provided with a lamp voltage monitoring circuit section 8 for monitoring the voltage of the high-pressure discharge lamp 6 as a control means in the configuration of FIG. 10, and outputs the output signal of the lamp voltage monitoring circuit section 8 to a power supply circuit section. 1, the DC output voltage of the power supply circuit unit 1 is controlled so that the lamp voltage of the high-pressure discharge lamp 6 (physical state of the high-pressure discharge lamp 6) is always constant. The configuration is similar to that of the conventional example of FIG.

In this way, when the lamp voltage is monitored and the DC output voltage of the power supply circuit unit 1 is controlled so that the lamp voltage of the high-pressure discharge lamp 6 is always constant, the lamp voltage rises due to an increase in lighting time. Can be compensated. This indirectly reduces the lamp power supplied to the high-pressure discharge lamp 6 as the lighting time increases, and
As in the case of the above embodiment, the increase in the maximum frequency f _AR at which the acoustic resonance phenomenon occurs is suppressed.

By doing so, the high-pressure discharge lamp 6
It is possible to always keep the lighting frequency f ₁ of higher than the highest frequency f _{AR at} which the high-pressure discharge lamp 6 causes the acoustic resonance phenomenon. That is, in this embodiment, the lamp voltage of the high-pressure discharge lamp generally increases in proportion to the lighting time, and the lamp voltage is controlled to be constant, so that the lighting time of the high-pressure discharge lamp is directly controlled. It is possible to suppress an increase in the maximum frequency f _AR at which an acoustic resonance phenomenon occurs due to an increase in lighting time of the high-pressure discharge lamp, without performing measurement.

FIG. 9 shows a specific circuit diagram of the lamp voltage monitoring circuit section 4. The lamp voltage detection circuit unit 4 detects the lamp voltage appearing across the high-pressure discharge lamp 6 by resistors R ₆ and R
_The voltage is divided by ₇ , and the divided voltage is rectified and smoothed by an integrating circuit composed of a diode D ₃ , resistors R ₈ , R ₉ and a capacitor C ₃ , and the obtained voltage is obtained by an operational amplifier OP.
₂ is input to the non-inverting input terminal of the operational amplifier OP ₂ and the reference voltage E ₁ is input to the inverting input terminal of the operational amplifier OP ₂ .
The output of the operational amplifier OP ₂ is fed back to the power supply circuit section 1.

With such a configuration, the operational amplifier OP ₂
The input voltage to the non-inverting input terminal of is always the operational amplifier OP ₂
It operates so as to coincide with the reference voltage E ₁ of the inverting input terminal, that is, the lamp voltage is always constant. Since there is a period in which the light output is small in the initial stage of lighting of the high-pressure discharge lamp 6, in practice, there is a circuit that does not perform the above lamp voltage constant control in the initial stage of lighting of the high-pressure discharge lamp 6. Will be needed.

The high pressure discharge lamp lighting device of this embodiment monitors the lamp voltage and controls the DC output voltage of the power supply circuit unit 1 so that the lamp voltage of the high pressure discharge lamp 6 is always constant. It is possible to suppress an increase in the maximum frequency f _{AR at which} the high-pressure discharge lamp 6 causes an acoustic resonance phenomenon due to an increase in the lamp voltage with an increase in the lighting time of the lamp 6, and thus, the lighting frequency f ₁ of the high-pressure discharge lamp 6 is always high. The discharge lamp 6 can be kept in a state higher than the highest frequency f _AR that causes the acoustic resonance phenomenon, and the high-pressure discharge lamp 6 does not cause the acoustic resonance phenomenon in any state from a new state to the end of life. High-frequency lighting can be stably performed.

[0034]

According to the high pressure discharge lamp lighting device of the first aspect of the present invention, the maximum frequency at which the lighting time of the high pressure discharge lamp is detected and the acoustic resonance phenomenon of the high pressure discharge lamp occurs is always less than the lighting frequency of the high pressure discharge lamp. Since the control means for increasing the lighting frequency of the high pressure discharge lamp according to the increase of the lighting time is provided, the lighting frequency of the high pressure discharge lamp can be increased according to the increase of the lighting time of the high pressure discharge lamp. . Therefore, the lighting frequency of the high-pressure discharge lamp can always be kept higher than the highest frequency at which the high-pressure discharge lamp produces an acoustic resonance phenomenon, and the high-pressure discharge lamp can be operated in any state from a new state to the end of life. It is possible to stably turn on the high frequency without causing a dynamic resonance phenomenon.

According to the high pressure discharge lamp lighting device of the second aspect of the present invention, the lamp characteristic that changes according to the increase of the lighting time of the high pressure discharge lamp is detected instead of the lighting time of the high pressure discharge lamp. The lighting frequency of the high-pressure discharge lamp can be increased in accordance with changes in the lamp characteristics that change as the lighting time of the discharge lamp increases. Therefore, the lighting frequency of the high-pressure discharge lamp can always be kept higher than the highest frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon, and the same effect as that of claim 1 can be achieved.

According to the high pressure discharge lamp lighting device of the third aspect, the highest frequency at which the lighting time of the high pressure discharge lamp is detected and the high pressure discharge lamp causes the acoustic resonance phenomenon is always less than the lighting frequency of the high pressure discharge lamp. Since the control means is provided to suppress the increase in the maximum frequency at which the high-pressure discharge lamp causes an acoustic resonance phenomenon by changing the physical state of the high-pressure discharge lamp according to the increase in the lighting time, It is possible to change the physical state of the high-pressure discharge lamp according to the increase of the time, and suppress the increase of the maximum frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon. Therefore,
The lighting frequency of the high-pressure discharge lamp can always be kept higher than the highest frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon, and the same effect as in claim 1 can be achieved.

According to the high pressure discharge lamp lighting device of the fourth aspect, the control means reduces the power supplied to the high pressure discharge lamp as the lighting time increases. By reducing the power supplied to the discharge lamp, it is possible to suppress the increase in the maximum frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon. Therefore, the lighting frequency of the high-pressure discharge lamp can always be kept higher than the highest frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon, and the same effect as that of claim 1 can be achieved.

In the high pressure discharge lamp lighting device according to the fifth aspect of the present invention, the control means controls the lamp voltage in a steady lighting state of the high pressure discharge lamp so that the lamp voltage is increased as the lighting time increases. When it is going to rise, the lamp power can be reduced so as to suppress it, and the highest frequency rise that causes the acoustic resonance phenomenon of the high pressure discharge lamp can be suppressed. Therefore, the lighting frequency of the high-pressure discharge lamp can always be kept higher than the highest frequency at which the high-pressure discharge lamp causes the acoustic resonance phenomenon, and the same effect as that of claim 1 can be achieved.

[Brief description of drawings]

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

FIG. 2 is a specific circuit diagram of a timer circuit unit in the high pressure discharge lamp lighting device of FIG.

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

FIG. 4 is a specific circuit diagram of a lamp voltage detection circuit unit in the high pressure discharge lamp lighting device of FIG.

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

6 is a specific circuit diagram of a light output detection circuit unit in the high pressure discharge lamp lighting device of FIG.

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

FIG. 8 is a block diagram showing the configuration of a high pressure discharge lamp lighting device according to a fifth embodiment of the present invention.

9 is a specific circuit diagram of a timer circuit unit in the high pressure discharge lamp lighting device of FIG.

FIG. 10 is a block diagram showing a configuration of an example of a conventional high pressure discharge lamp lighting device.

[Explanation of symbols]

 1 Power Supply Circuit Section 2 Inverter Circuit Section 3 Timer Circuit Section 4 Lamp Voltage Detection Circuit Section 5 Light Output Detection Circuit Section 6 High Voltage Discharge Lamp 7 Timer Circuit Section 8 Lamp Voltage Monitoring Circuit Section

Claims (5)

[Claims] 1. A high pressure discharge lamp lighting device for lighting a high pressure discharge lamp at a high frequency, wherein a maximum frequency at which the lighting time of the high pressure discharge lamp is detected and the high pressure discharge lamp causes an acoustic resonance phenomenon is always A high pressure discharge lamp lighting device, comprising: a control means for increasing a lighting frequency of the high pressure discharge lamp in accordance with an increase in the lighting time so that the lighting frequency is lower than the lighting frequency. 2. The high pressure discharge lamp lighting device according to claim 1, wherein a lamp characteristic that changes according to an increase in lighting time of the high pressure discharge lamp is detected instead of the lighting time of the high pressure discharge lamp. 3. A high-pressure discharge lamp lighting device for lighting a high-pressure discharge lamp at a high frequency, wherein the highest frequency at which the lighting time of the high-pressure discharge lamp is detected and the high-pressure discharge lamp causes an acoustic resonance phenomenon is always A control means is provided for changing the physical state of the high-pressure discharge lamp according to the increase of the lighting time so as to be less than the lighting frequency, and suppressing an increase in the maximum frequency at which the high-pressure discharge lamp causes an acoustic resonance phenomenon. A high-pressure discharge lamp lighting device characterized in that 4. The physical condition of the high-pressure discharge lamp is electric power supplied to the high-pressure discharge lamp, and the electric power supplied to the high-pressure discharge lamp is decreased by the control means in accordance with an increase in lighting time. Item 3. The high pressure discharge lamp lighting device according to Item 3. 5. The physical condition of the high-pressure discharge lamp is the lamp voltage of the high-pressure discharge lamp, and the control unit controls the lamp voltage in a steady lighting state of the high-pressure discharge lamp to be constant. High pressure discharge lamp lighting device.