JP2007087821A - High-pressure discharge lamp lighting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp lighting device capable of properly controlling lamp power and the operating frequency to avoid an acoustic resonance phenomenon, when a lamp is in transit state after it is started and it is stably lighted. <P>SOLUTION: This high-pressure discharge lamp lighting device has a dc power supply means 12, an inverter means 16, a high-pressure discharge lamp HID, a lamp voltage detecting means 19, a lamp power detecting means 15, 18, and a control means 20. The control means 20 is to control the dc voltage from the dc power supply means 12 and the operating frequency of the inverter means 16. Under a transient state after the lamp is started, the control means controls the lamp power by controlling the operating frequency of the inverter means 16 until the lamp voltage reaches a prescribed lamp voltage, and controls the lamp power by controlling the dc voltage from the dc power supply means 12 after the lamp voltage has reached the prescribed voltage. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a high-pressure discharge lamp lighting device for lighting a high-pressure discharge lamp at a high frequency, and power control of an illumination device.

  In general, in a discharge lamp lighting device, high-frequency lighting using a switching power supply circuit is performed in order to reduce the size and weight of components and to perform stable lighting without flicker. On the other hand, it is also known that when a discharge lamp is lit at a high frequency, an acoustic resonance phenomenon easily occurs and the lighting state becomes unstable.

  There are various types of switching power supply circuits used for high-frequency lighting. Here, a chopper-type switching power supply circuit and its output voltage are converted to high-frequency AC voltage using an inverter circuit, and a high-voltage discharge that is a load. A high pressure discharge lamp lighting device supplied to the lamp will be described.

  In general, a high-pressure discharge lamp lighting device having an inverter circuit for lighting a high-pressure discharge lamp prevents the high-pressure discharge lamp from causing an acoustic resonance phenomenon, so that the switching frequency of the switching element of the inverter circuit (hereinafter referred to as the operating frequency). ) To the non-resonant frequency band, the operating frequency is made substantially constant, and the lamp output is controlled in that state.

  For example, in a high pressure discharge lamp lighting device in which a boost chopper circuit is connected to a power source, an inverter circuit is connected to the boost chopper circuit, and a high pressure discharge lamp is lit by the inverter circuit, the operating frequency of the inverter circuit is not changed much. The lamp power is controlled by controlling the DC voltage from the step-up chopper circuit.

  For example, Patent Document 1 discloses control that does not simultaneously perform frequency control for avoiding acoustic resonance and direct-current voltage control for controlling lamp power.

For example, Patent Document 2 discloses that the operating frequency of the high-frequency inverter is moved (changed) in a direction in which the lamp current (tube current) decreases when acoustic resonance occurs and the lamp voltage (tube voltage) increases. Has been. Here, when the inductive ballast is used, when the lamp voltage increases, the operating frequency of the inverter is increased to decrease the lamp current. Thereby, lamp electric power is reduced and excessive input of electric power can be suppressed.
JP 2004-235033 A JP-A-60-235396

   By the way, if the lamp power is controlled by the DC voltage control from the DC power supply means including the step-up chopper circuit in the entire period from the transient state after the lamp start to the stable lighting state by the high pressure discharge lamp, the DC power from the DC power supply means is obtained. There is a problem that the voltage fluctuation range becomes too large, and a component having a high withstand voltage or the like is required in response to this change.

  On the other hand, in order to cope with the acoustic resonance phenomenon, when the operating frequency is controlled, it is necessary to limit the control range of the operating frequency to a predetermined range for the convenience of changing the lamp power. Incidentally, a non-resonant frequency band (stable region) where no acoustic resonance phenomenon occurs exists on the operating frequency axis as shown in FIG. It is known that this non-resonant frequency band (stable region) moves on the frequency axis in a transient state in the middle of rising after starting the lamp. When the operating frequency is gradually increased and controlled to avoid acoustic resonance in a transient state, and the operating frequency has moved to the end (upper limit) of the predetermined range, no further acoustic resonance will occur. It cannot be avoided. Here, if the operating frequency is once again lowered to the lower limit side of the predetermined range, if the frequency is simply lowered, the lamp power increases as can be seen from the operating frequency versus lamp power characteristics shown in FIG. Therefore, there is a problem that excessive power is input and it is dangerous.

  Therefore, in view of the above problems, the present invention provides a high pressure discharge lamp lighting device capable of appropriately controlling lamp power without relying solely on DC voltage control in the process from the start of the lamp to the stable lighting state. It is for the purpose. Another object is to control the limited frequency while controlling the operating frequency of the inverter in order to avoid the acoustic resonance phenomenon when the high-pressure discharge lamp is turned on at a high frequency. By providing a high pressure discharge lamp lighting device and an illuminating device that can suppress a rapid increase in lamp power that occurs when the frequency is lowered again to the lower limit side of the predetermined range when the frequency rises to the upper limit of the range. is there.

  The high-pressure discharge lamp lighting device according to the first aspect of the present invention comprises a DC power supply means for inputting a power supply voltage from an AC power supply and generating a DC voltage; and converting the DC voltage from the DC power supply means into a high-frequency voltage; Inverter means for lighting a high pressure discharge lamp including a resonance circuit; lamp voltage detection means for detecting a lamp voltage of the high pressure discharge lamp; lamp power detection means for detecting lamp power of the high pressure discharge lamp; and DC power supply means Control means for controlling the DC voltage from the inverter and the operating frequency of the inverter means, in the transient state after starting the lamp, controlling the operating frequency of the inverter means until the lamp voltage reaches a predetermined value. The lamp power is controlled by the control, and after the lamp voltage reaches the predetermined value, the DC voltage from the DC power supply means is controlled. It is obtained by including a; and control means for controlling the lamp power by.

In the present invention and the following description, the definitions and technical meanings of terms are as follows unless otherwise specified.
The high-pressure discharge lamp includes a mercury lamp, a metal halide lamp, a high-pressure sodium lamp, and the like. Also included is a ceramic discharge lamp using an alumina tube as the arc tube.

  The DC power supply means is composed of, for example, a full-wave rectifier circuit that rectifies an AC power supply voltage and a boost chopper circuit that generates a DC voltage that is boosted by inputting the rectified voltage.

  The inverter means is composed of, for example, a half-bridge type high-frequency inverter having two switching elements that are alternately turned on and off and an LC resonance circuit, and the switching frequency (operating frequency) is controlled by the control means, and the high-frequency output is a high-voltage discharge. Applied to both ends of the lamp, the high pressure discharge lamp is turned on at high frequency.

  The predetermined value of the lamp voltage for switching between the control of the operating frequency of the inverter means and the control of the DC voltage from the DC power supply means, which is performed when the control means performs power control, is, for example, 50 to 50 of the lamp saturation voltage at the time of stable lamp lighting. The voltage value is 60%. After starting the lamp, the operation frequency is controlled, and when the lamp voltage reaches a voltage value of 50 to 60%, the control is switched to the DC voltage control.

  The lamp voltage detection means includes, for example, a detection circuit that detects a high-frequency voltage at both ends of the high-pressure discharge lamp, and a voltage doubler rectifier circuit that rectifies and smoothes the high-frequency voltage using two sets of diodes and capacitors. This lamp voltage detection means is used to detect the predetermined value of the lamp voltage when the control is switched by the control means, and when the acoustic resonance phenomenon occurs, the lamp voltage fluctuates and rises. It is also used to detect the occurrence of acoustic resonance (acoustic resonance determination) by detecting.

  The lamp power detection means includes, for example, detection means for detecting a DC voltage from the DC power supply means and detection means for detecting a switching element current of the inverter means, and calculates the detected voltage and current to calculate the lamp power. A signal corresponding to power is obtained.

  The high-pressure discharge lamp lighting device according to claim 2 is the high-pressure discharge lamp lighting device according to claim 1, wherein the DC voltage from the DC power supply means until the lamp voltage reaches a predetermined value is a predetermined value. The operating frequency of the inverter means after being held and after the lamp voltage reaches a predetermined value is controlled to a non-acoustic resonance frequency.

  The high-pressure discharge lamp lighting device according to claim 3 is the high-pressure discharge lamp lighting device according to claim 1 or 2, wherein the lamp power detection means includes a DC voltage detection means from the DC power supply means, and the inverter means. Switching element current detection means.

  The high pressure discharge lamp lighting device according to claim 4 is the high pressure discharge lamp lighting device according to any one of claims 1 to 3, wherein the lamp voltage detection means detects a high frequency voltage across the high pressure discharge lamp. A first circuit for rectifying and smoothing a half-wave voltage of an AC half cycle of the high-frequency voltage detected by the detection circuit, and a next AC half-cycle of the first circuit after the rectified and smoothed voltage of the first circuit. And a second circuit for rectifying and smoothing a voltage obtained by adding the half-wave voltage.

  According to a fifth aspect of the present invention, there is provided a high pressure discharge lamp lighting device comprising: a DC power supply means for inputting a power supply voltage from an AC power supply and generating a DC voltage; and converting the DC voltage from the DC power supply means into a high frequency voltage, Inverter means for lighting the discharge lamp; lamp voltage detection means for detecting the lamp voltage of the high pressure discharge lamp; lamp power detection means for detecting lamp power of the high pressure discharge lamp; The lamp has a function of controlling a DC voltage and an operating frequency of the inverter means, and the lamp is operated while moving the operating frequency of the inverter means by a predetermined value in a high direction at the time of acoustic resonance determination due to a rise in lamp voltage after starting the lamp. The control for checking the change in voltage is to find a stable lighting state and to avoid the occurrence of an acoustic resonance phenomenon. The lamp power is controlled to a predetermined value by controlling the DC voltage from the source means, and when the operating frequency of the inverter means reaches the end of the predetermined range (maximum value), Control means for performing a first control for reducing the lamp power by controlling a DC voltage from a DC power supply means and a second control for reducing the operating frequency of the inverter means thereafter. It is.

  The lighting device according to claim 6 is equipped with the high-pressure discharge lamp lighting device according to any one of claims 1 to 5; the high-pressure discharge lamp lit by the high-pressure discharge lamp lighting device; and the high-pressure discharge lamp mounted An instrument body to be provided.

  According to the first aspect of the present invention, in a transient state after starting the lamp, the acoustic resonance phenomenon hardly occurs in the first section (A in FIG. 2) from when the lamp starts until the lamp voltage reaches a predetermined value. Therefore, it is not necessary to use the operating frequency control of the inverter means to avoid the acoustic resonance phenomenon. Therefore, the operating frequency control of the inverter means can be used only for power control that matches the target power characteristic curve (see the lamp power curve in FIG. 3). Accordingly, it is not necessary to control the lamp power by direct current voltage control from the direct current power supply means in the first section, and the direct current is not reached in the second section (B in FIG. 2) until the lamp voltage reaches a predetermined value. Since lamp power control based on voltage control is used, the fluctuation range of the DC voltage from the DC power supply means does not become too large, and it is not necessary to prepare components with high breakdown voltage. In other words, in a transient state after starting the lamp, it is possible to appropriately control the lamp power by appropriately changing the way of lamp power control according to the lamp voltage.

According to the invention of claim 2, the same effect as that of claim 1 can be obtained, the first section holds the DC voltage from the DC power supply means at a constant value, and the second section is the operating frequency of the inverter means. Can be maintained at non-acoustic resonance frequencies. Therefore, it is possible to control the lamp power while avoiding acoustic resonance.
According to the invention of claim 3, a signal corresponding to the lamp power can be obtained.
According to the invention of claim 4, the change of the lamp high-frequency voltage can be detected by rectifying and smoothing.

According to the invention of claim 5, in order to avoid the acoustic resonance phenomenon when the high-pressure discharge lamp is turned on at a high frequency, when controlling the operating frequency of the inverter, the limited frequency Thus, it is possible to suppress a rapid increase in lamp power that occurs when the frequency is lowered again after the frequency has risen to the upper limit of the control range, and the stress applied to the components can be reduced.
Furthermore, according to invention of Claim 6, the illuminating device which has an effect in any one of Claims 1-5 is obtained.

Embodiments of the invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a circuit diagram showing a high pressure discharge lamp lighting device according to a first embodiment of the present invention.
In FIG. 1, a high pressure discharge lamp lighting device 10 includes an AC power source AC, a noise filter circuit 11 including capacitors C1, C2 and a transformer T1, a full-wave rectifier circuit 13 including diodes D1 to D4, and a high-frequency component removing unit. A capacitor C3, a coil L1, a switching element Q1, a diode D5, and an output capacitor C4, a rectified voltage from the full-wave rectifier circuit 13 and a DC voltage VDC, and a step-up chopper circuit 14 for generating a DC voltage VDC; The voltage detection line 15 and the DC voltage VDC from the step-up chopper circuit 14 are input to both ends of two switching elements Q2 and Q3 that are connected in series and alternately turned on and off, and a high-frequency AC voltage (hereinafter simply referred to as a high-frequency voltage). An inverter circuit which is an inverter means including the LC resonance circuit 17 for converting to a high pressure discharge lamp HID 16, a current detection circuit 18 that is a switching element current detection means of the inverter circuit 16, a high-pressure discharge lamp HID, and a lamp voltage detection circuit 19 as lamp voltage detection means that detects the lamp voltage of the high-pressure discharge lamp HID, The DC voltage VDC output from the boost chopper circuit 14 is controlled by controlling one or both of the switching frequency and the duty ratio of the switching element Q1 of the boost chopper circuit 14, or the two switching elements Q2, Q3 of the inverter circuit 16 are controlled. And a control circuit 20 which is a control means for controlling the lighting frequency of the high-pressure discharge lamp HID by controlling the switching frequency (operating frequency).

  The diode D8 and the capacitor C10 are circuits for detecting the current flowing in the primary coil L1 of the transformer T2 provided on the input side of the step-up chopper circuit 14 with the secondary coil, rectifying and smoothing it, and transmitting it to the control circuit 20. It is. A resistor R6 provided between the source of the switching element Q1 of the boost chopper circuit 14 and the reference potential point is a resistor for detecting and transmitting the current flowing through the switching element Q1 to the control circuit 20.

  In the present embodiment, the control circuit 20 controls the DC voltage VDC output from the DC power supply circuit 12 and controls the operating frequency of the inverter circuit 16, but in a transient state after starting the lamp, The lamp power is controlled by controlling the operating frequency of the inverter circuit 16 until the voltage reaches a predetermined value. After the lamp voltage reaches the predetermined value, the direct-current voltage VDC from the DC power supply circuit 12 is controlled. It has a function to control lamp power.

  A predetermined value (corresponding to D in FIG. 2) of the lamp voltage for switching between the control of the operating frequency of the inverter circuit 16 and the control of the DC voltage from the DC power supply circuit 12 performed when the control circuit 20 performs power control. The voltage value is, for example, 50 to 60% of the lamp saturation voltage when the lamp is stably lit. This predetermined value is, for example, a predetermined voltage value of, for example, 50 to 60% in which the lamp voltage reaches a saturation voltage immediately after starting (that is, immediately after lighting) in a transient state where the lamp voltage of the high-pressure discharge lamp HID gradually increases after starting. In the first section A until reaching, the acoustic resonance phenomenon hardly occurs, and the second section B in which the lamp voltage reaches the predetermined voltage value of, for example, 50 to 60% at which the lamp voltage reaches the saturation voltage and becomes higher. Then, it is based on becoming easy to generate | occur | produce an acoustic resonance phenomenon.

  A DC power supply circuit 12 as a DC power supply means includes diodes D1 to D4, receives an AC power supply voltage from the AC power supply AC, and performs full-wave rectification, a full-wave rectifier circuit 13, a primary coil L1 of the transformer T2, and a switching element Q1. , A diode D5 and an output capacitor C4, and a boost chopper circuit 14 for inputting a full-wave rectified voltage from the full-wave rectifier circuit 13 and generating a predetermined DC voltage VDC by boosting the full-wave rectified voltage.

  The step-up chopper circuit 14 stores energy in the primary coil L1 of the transformer T2 when the switching element Q1 is on, and the diode D5 conducts when Q1 is off, and outputs the energy stored in the primary coil L1. Discharge to capacitor C4. At this time, the voltage generated in the primary coil L1 of T2 is added in series to the input voltage (rectified voltage from the rectifier circuit 13), so that the output voltage is higher than the input (boosted voltage). The DC voltage VDC output from the step-up chopper circuit 14 is controlled by controlling one or both of the switching frequency and the duty ratio of the switching element Q1.

The inverter circuit 16 receives the DC voltage VDC from the step-up chopper circuit 14 and receives two switching circuits connected in series that are alternately turned on and off by two types of switching pulses having the same switching frequency and a duty ratio of 50% and inversion relationship with each other. It is composed of a half-bridge type high-frequency inverter having elements Q1, Q2, a DC cut capacitor C5, and an LC resonance circuit 17 comprising a coil L2 and a capacitor C6, and inputs a DC voltage from the DC power supply circuit 12. It converts into a high frequency voltage and supplies it to the high pressure discharge lamp HID.
The lighting frequency of the high-pressure discharge lamp HID is controlled by controlling the switching frequency (operating frequency) of the two switching elements Q2 and Q3 of the inverter circuit 16.

The high frequency output from the inverter circuit 16 is applied to both ends of the high pressure discharge lamp HID, and the high pressure discharge lamp HID is turned on at high frequency.
The inverter circuit 16 includes, for example, drains of two N-channel FETs as switching elements Q2 and Q3 between the positive output terminal and the negative output terminal (reference potential point) of the output capacitor C4 of the boost chopper circuit 14, A source is connected in series, and a parasitic diode (not shown) is connected in parallel with the switching element Q2 so that the current flows in a direction opposite to the switching current of the switching element Q2. Similarly, the switching current of the switching element Q3 A parasitic diode (not shown) is connected in parallel with the switching element Q3 so that the current flows in the opposite direction, and a capacitor C5 is interposed between the connection point of the switching elements Q2 and Q3 and the reference potential point. Is connected to a resonance circuit 17 comprising a coil L2 and a capacitor C6, and in parallel with the capacitor C6 of the resonance circuit 17, a high-pressure discharge lamp HID. Are connected to the gates of the switching elements Q2 and Q3. The control circuit 20 supplies switching pulses for alternately turning on and off the two switching elements Q2 and Q3 at a desired operating frequency.

  The operation of the inverter circuit 16 will be briefly described. When AC power AC is input, DC voltage VDC output from DC power supply circuit 12 is supplied to both ends of a series circuit of switching elements Q2 and Q3 in inverter circuit 16. The switching elements Q2, Q3 are alternately turned on and off by switching pulses of a predetermined frequency from the control circuit 20. When switching element Q2 is on and switching element Q3 is off, current flows along the path from the positive output terminal of output capacitor C4 to switching element Q2, capacitor C5, coil L2, capacitor C6, and negative output terminal of output capacitor C4. Then, when switching element Q2 is turned off and switching element Q3 is turned on, coil L2 → capacitor C6 → parasitic diode of switching element Q3 (not shown) → capacitor C5 based on the energy stored in coil L2. Current flows. As a result, the capacitor C6 is charged, and a current flows through the path of the capacitor C6 → the coil L2 → the capacitor C5 → the switching element Q3 → the capacitor C6 based on the charging voltage of the capacitor C6 while the switching element Q3 is on. Next, when switching element Q2 is turned on and switching element Q3 is turned off, based on the energy stored in coil L2, current first flows through the path of capacitor C6 → coil L2 → capacitor C5 → parasitic diode (not shown). Thereafter, the current flows again through the path of the positive output side of the output capacitor C4 → the switching element Q2 → the capacitor C5 → the coil L2 → the capacitor C6 → the negative output side of the output capacitor C. That is, a resonance current flows through the coil L2 and the capacitor C6 of the LC resonance circuit 17. Then, the high-pressure discharge lamp HID starts to discharge by the resonance voltage generated at this time and lights up. After the high-pressure discharge lamp HID is lit, a discharge current flows through the capacitor C5, coil L2, and the high-pressure discharge lamp HID as the main current paths, and the capacitor C5 is charged and discharged along with the on / off operation of the switching elements Q2 and Q3. Then, energy is stored and released in the coil L2, and a high-frequency current according to the switching frequency (operating frequency) of the control circuit 20 flows through the discharge lamp HID to maintain high-frequency lighting.

  The lamp power detection means detects the current Idet flowing through the switching element Q3 of the inverter circuit 16 and the voltage detection means including the detection line 15 for detecting the DC voltage VDCdet output from the DC power supply circuit 12. The resistors R1, R2 And a current detection means comprising a capacitor C7, and the control circuit 20 calculates the detected voltage VDCdet and current Idet to obtain a signal corresponding to the lamp power.

  The lamp voltage detection circuit 19 includes a detection circuit that detects a high-frequency voltage at both ends of the high-pressure discharge lamp HID by dividing it with a series circuit of resistors R3 and R4, a diode D6, and a capacitor C8. A first circuit for rectifying and smoothing a wave voltage, a diode D7 and a capacitor C9, and rectifying and smoothing a voltage obtained by adding a half-wave voltage of an AC half cycle next to the high-frequency voltage to the rectified and smoothed voltage of the first circuit. The second circuit is composed of a voltage doubler rectifier circuit using two circuits. The direct-current lamp detection voltage detected by the lamp voltage detection circuit 19 is used for switching the control method for detecting the predetermined value of the lamp voltage by the control circuit 20 and controlling the lamp power, and acoustic resonance. When a phenomenon occurs, the lamp voltage rises compared to that during non-acoustic resonance. Therefore, it is also used to detect the occurrence of the acoustic resonance phenomenon (that is, to determine acoustic resonance) by detecting the rise in the lamp voltage.

2 and 3 show an example of the transient characteristics after starting the lamp. FIG. 2 shows lamp voltage characteristics, and FIG. 3 shows lamp power characteristics.
The lamp voltage characteristic shown in FIG. 2 is a characteristic unique to each lamp. On the other hand, the lamp power characteristic shown in FIG. 3 is a power characteristic curve after starting the lamp, which is an ideal target power curve in power control. It matches.

  As shown in FIG. 2, the lamp voltage gradually increases after starting the lamp. This transient voltage increase period is a period during which the temperature of the arc tube is increasing. As a result of the experiment, the acoustic resonance phenomenon hardly occurs in the initial period A during the transient state period. Therefore, the lamp power control in the initial period A (in this period, 0 ≦ lamp voltage <D) during the transition period in which no acoustic resonance phenomenon occurs is performed by operating frequency control of the inverter circuit 16, so that the entire period is The control range of the DC voltage VDC can be made smaller than when the boost chopper circuit 14 is controlled by the DC voltage VDC, and component selection from the viewpoint of component breakdown voltage is facilitated.

FIG. 4 shows the waveform of the double voltage rectified voltage in the lamp voltage detection circuit, that is, the waveform of the output signal of the capacitor C9 at the point g of the lamp voltage detection circuit 19.
Here, the operation of the voltage doubler rectifier circuit using two circuits of the diode D6 and capacitor C8 circuit and the diode D7 and capacitor C9 circuit in the lamp voltage detection circuit 19 will be described. A high-frequency voltage is applied to both ends a and b of the high-pressure discharge lamp HID, and a high voltage is applied to the one end a of the high-pressure discharge lamp HID and a positive voltage to the other end b (that is, between e and b). ) Is applied to the anode of the diode D6 and charged to the capacitor C8, the point f becomes the + voltage and the point e becomes the -voltage. In this state, when the polarity of the voltage at both ends of the high-pressure discharge lamp HID is inverted and the point b becomes a negative voltage (that is, a positive voltage is applied between the positive and negative electrodes), the positive voltage at the point e is charged to the capacitor C8. 4 is added to the capacitor C9 through the diode D7, and the envelope C of the high-frequency voltage waveform j in FIG. A voltage corresponding to the waveform smoothed by C9) is output to the control circuit 20 as the lamp detection voltage VLdet. The lamp detection voltage VLdet is approximately twice the voltage (double voltage) of the voltage across the resistor R4.

  When the acoustic resonance phenomenon occurs, the lamp detection voltage VLdet increases as compared with the time of non-acoustic resonance. Therefore, the control circuit 20 sets the lamp detection voltage at that time to the reference voltage V1 (the voltage at the time of non-acoustic resonance). Generation of the acoustic resonance phenomenon can be detected (acoustic resonance determination).

  In the high-pressure discharge lamp lighting device of FIG. 1 configured as described above, the lamp power control after starting the lamp is performed by the control circuit 20 using the inverter circuit 16 so as to follow the rising curve of the target power curve (see FIG. 3). This is done by controlling the operating frequency.

  The lamp power control when the lamp is stable or after the rise (50 to 60% rise) after starting the lamp is controlled by the control circuit 20 switching from the operation frequency control of the inverter circuit 16 to the DC voltage control of the boost chopper circuit 14.

  The switching timing is performed when the detected value of the lamp voltage reaches a predetermined value D (see FIG. 2) of the above-described rising. That is, the present embodiment is characterized in that the lamp power control is performed by the operation frequency control of the inverter circuit 16 at the time of starting (at the time of rising).

  In the transient state after the lamp start, the acoustic resonance phenomenon hardly occurs in the first section A (see FIG. 2) from the start of the lamp until the lamp voltage reaches the predetermined value D. Therefore, the operating frequency of the inverter circuit 16 Control need not be used to avoid acoustic resonance phenomena. Therefore, in the first section A, the operating frequency control of the inverter circuit 16 can be used only for power control that matches the target power characteristic (see the lamp power curve in FIG. 3).

  Therefore, in the first section A, it is not necessary to control the lamp power by the DC voltage control from the DC power supply circuit 12, and the lamp power is controlled by the operating frequency control of the inverter circuit 16, while the lamp voltage is a predetermined value. Since the lamp power control by the DC voltage control of the DC power supply circuit 12 can be used in the second section B (see FIG. 2) after reaching D, only at the time of power control in the second section B The fluctuation range of the direct current voltage VDC from the direct current power supply circuit 12 does not become too large, and it is not necessary to select a part having a high withstand voltage.

  According to the first embodiment, in a transient state after starting the lamp, it is possible to appropriately control the lamp power by appropriately changing the way of lamp power control according to the lamp voltage.

[Second Embodiment]
The configuration of the high pressure discharge lamp lighting device used in the second embodiment of the present invention is the same as that of the first embodiment in FIG. The difference from the first embodiment is the function of the control circuit 20 as control means.

  FIG. 5 is a diagram showing whether or not an acoustic resonance phenomenon occurs. The horizontal axis represents the operating frequency of the inverter circuit 16. A frequency band surrounded by a square indicates a non-resonant frequency band (stable region) in which no acoustic resonance phenomenon occurs, and other frequency bands indicate acoustic resonance frequency bands (unstable regions). It is known that the non-resonant frequency band (stable region) moves on the frequency axis due to lamp variation, aging, lamp voltage fluctuation, and the like.

  FIG. 6 is a characteristic diagram showing the relationship between the output voltage (lamp voltage VL) of the inverter circuit 16 and the lamp power during lighting and the operating frequency in the second embodiment of the present invention. The lamp power at the time of lighting has a characteristic of decreasing monotonously as the operating frequency of the inverter circuit 16 is increased from a low frequency to a high frequency.

  As shown in FIG. 6, when starting the high-pressure discharge lamp, the inverter circuit 16 is controlled to oscillate at a frequency f1 that is 1/3 or more and 1/2 or less of the no-load resonance frequency f0. By setting the starting frequency within this range, it is possible to suppress the phase advance oscillation of the LC resonance circuit 17. Furthermore, even after the lamp is lit, power is supplied to the lamp so that the discharge can be maintained, so that the discharge can be maintained without the lamp going off.

  Then, the high pressure discharge lamp HID is turned on. After the high-pressure discharge lamp HID is lit, the frequency is controlled to be constant at a frequency f2 within a stable region where acoustic resonance does not occur within a range of 1/5 to 1/4 of the no-load resonance frequency f0. In this way, when the high-pressure discharge lamp is steadily lit, the vicinity of the highest point of the load power of the high-pressure discharge lamp can be set as the operating point of the high-pressure discharge lamp, and the high-pressure discharge lamp is extinguished due to extinction or the like during stable lighting. Even in this case, the phase advance oscillation can be suppressed and the switching loss can be suppressed low.

  As described above, it has been experimentally found that the acoustic resonance phenomenon hardly occurs in the predetermined period A (see FIG. 2) at the time of starting the lamp (at the time of rising). Therefore, in the period A at the time of starting (at the time of rising), it is not necessary to perform the operation frequency control of the inverter circuit 16 according to the lamp voltage fluctuation based on the acoustic resonance, and the power control that matches the target power characteristic (see FIG. 3). The operating frequency is controlled to perform the above. In a period B (see FIG. 2) from the latter half of the ramp rise to the lamp stabilization time, the operation frequency control of the inverter circuit 16 is performed according to the lamp voltage fluctuation based on the acoustic resonance to control the lamp voltage fluctuation based on the acoustic resonance. On the other hand, as a result of the operating frequency control, the power is adjusted by controlling the DC voltage VDC of the DC power supply circuit 12 as much as the lamp power does not meet the target power characteristics.

  Regarding the control in period B, if the operating frequency of the inverter circuit 16 is changed (increased) so that stable lighting without the lamp voltage fluctuation based on the acoustic resonance phenomenon occurs, the lamp power does not match the target power characteristic. As a result, lamp power control by DC voltage control of the boost chopper circuit 14 is performed, and the lamp power is controlled to a desired value (target power value).

  On the other hand, in order to avoid the above-described acoustic resonance phenomenon, that is, to eliminate the lamp voltage fluctuation, when the operating frequency of the inverter circuit 16 is increased to obtain a stable region without the acoustic resonance phenomenon, the operating frequency adjustment range is also included. Because there is a restriction (predetermined range), when the upper limit of the operating frequency is reached, the operating frequency is returned to the lower frequency side and then raised again, and there is no acoustic resonance phenomenon (ie, there is no lamp voltage fluctuation). The operating frequency is controlled so as to search the frequency domain. At that time, when the operating frequency is switched from a high (upper limit) to a low one at a time (abruptly), the lamp power changes from a low to a suddenly increasing direction (see FIG. 6). As a result, sudden power input may cause a problem due to the breakdown voltage of the components.

For this reason, in the second embodiment, the control circuit 20 as the control means performs the following control.
That is, the control circuit 20 has a function of controlling the DC voltage from the DC power supply circuit 12 and the operating frequency of the inverter circuit 16, and at the time of acoustic resonance determination due to the increase in lamp voltage after starting the lamp (see FIG. 4). In addition, a stable lighting state is found by control for checking the lamp detection voltage from the lamp power detection circuit 19 while moving the operating frequency of the inverter circuit 16 by a predetermined value in the higher direction so as to avoid the occurrence of the acoustic resonance phenomenon. At the same time, the lamp power is controlled to be a predetermined value (target power value) by controlling the DC voltage from the DC power supply circuit 12, and the operating frequency of the inverter circuit 16 reaches the end of the predetermined range (maximum value). ), The lamp power is reduced by a predetermined amount by controlling the DC voltage from the DC power supply circuit 12 as shown in FIG. Control (indicated by reference symbol E) and then second control (indicated by reference symbol F) for lowering the operating frequency of the inverter circuit 16 to the beginning (minimum value) of the predetermined range or close thereto It is.

  When returning the operating frequency of the inverter circuit 16 from high to low, first, as (1) the first control, after the lamp power is once controlled to a low level by the DC voltage control of the inverter circuit 16 (this is the lamp power Changing the lamp to the higher one at a time hinders the viewpoint of component pressure resistance, etc., but changing the lamp power to the lower one at once does not cause any trouble), then (2) As the second control, The operating frequency is switched to a lower speed at a high speed (at a stroke) so as to return the operating frequency of the inverter circuit 16 to a lower frequency. Due to this (2), even if the operating frequency is switched to a lower one, the absolute value of the switchable lamp power is low, so that there is no problem due to component pressure resistance or the like. In addition, in (2), by switching the operating frequency of the inverter circuit 16 from high to low at once, the acoustic resonance region (unstable region) existing in the operating frequency band is instantaneously returned to a low frequency. be able to.

[Third Embodiment]
FIG. 7 is an explanatory diagram of a lighting apparatus according to the third embodiment of the present invention. The high-pressure discharge lamp lighting device 10 according to the first embodiment constitutes an illuminating device 21 together with an appliance main body 23 to which the high-pressure discharge lamp HID is attached. As shown in FIG. 7, the high-pressure discharge lamp HID is mounted on the socket 24 of the instrument body 23 and is lit by the high-pressure discharge lamp lighting device 10. Light from the lit high-pressure discharge lamp HID is reflected by the front reflector 25 and irradiated through the front glass 26. According to the illumination device of this embodiment, an illumination device having the effect of the high-pressure discharge lamp lighting device 10 in the first embodiment can be obtained.

1 is a circuit diagram showing a high-pressure discharge lamp lighting device according to a first embodiment of the present invention. The figure which is an example of the transient characteristic after the start of a lamp | ramp, and shows a lamp voltage characteristic. The figure which is an example of the transient characteristic after a start of a lamp | ramp, and shows a lamp | ramp electric power characteristic (target electric power characteristic). The figure which shows the waveform of the voltage doubler rectification output signal in a lamp voltage detection circuit. The figure which shows the presence or absence of generation | occurrence | production of the acoustic resonance phenomenon. The characteristic view which shows the output voltage (lamp voltage VL) of the inverter circuit in the 2nd Embodiment of this invention, the relationship between the lamp electric power at the time of lighting, and an operating frequency. Sectional drawing which shows the illuminating device of the 3rd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... High pressure discharge lamp lighting device, 12 ... DC power supply circuit (DC power supply means), 13 ... Full wave rectifier circuit, 14 ... Boost chopper circuit, 15 ... DC voltage detection line (DC voltage detection means), 16 ... Inverter circuit ( Inverter means), 17 ... LC resonance circuit, 18 ... current detection circuit (current detection means), 19 ... lamp voltage detection circuit (lamp voltage detection means), 20 ... control circuit (control means), 21 ... lighting device, HID ... High pressure discharge lamp.

Claims (6)

DC power supply means for inputting a power supply voltage from an AC power supply and generating a DC voltage;
Inverter means for converting a DC voltage from the DC power supply means into a high-frequency voltage and lighting a high-pressure discharge lamp including an LC resonance circuit;
Lamp voltage detecting means for detecting a lamp voltage of the high-pressure discharge lamp;
Lamp power detection means for detecting lamp power of the high-pressure discharge lamp;
Control means for controlling the direct-current voltage from the direct-current power supply means and the operating frequency of the inverter means, the operating frequency of the inverter means until the lamp voltage reaches a predetermined value in a transient state after starting the lamp Controlling the lamp power by controlling the lamp power, and controlling the lamp power by controlling the DC voltage from the DC power supply means after the lamp voltage reaches the predetermined value;
A high-pressure discharge lamp lighting device comprising:   The DC voltage from the DC power supply means until the lamp voltage reaches a predetermined value is held at a predetermined value, and the operating frequency of the inverter means after the lamp voltage reaches a predetermined value is The high pressure discharge lamp lighting device according to claim 1, wherein the high pressure discharge lamp lighting device is controlled to an acoustic resonance frequency.   3. The high-voltage discharge according to claim 1, wherein the lamp power detection means includes a DC voltage detection means from the DC power supply means and a switching element current detection means of the inverter means. Lamp lighting device.   The lamp voltage detection means includes a detection circuit that detects a high-frequency voltage across the high-pressure discharge lamp, a first circuit that rectifies and smoothes a half-wave voltage of an AC half cycle of the high-frequency voltage detected by the detection circuit, 4. A second circuit for rectifying and smoothing a voltage obtained by adding a half-wave voltage of an AC half cycle next to the high-frequency voltage to the rectified and smoothed voltage of the first circuit. The high-pressure discharge lamp lighting device according to any one of the above. DC power supply means for inputting a power supply voltage from an AC power supply and generating a DC voltage;
Inverter means for converting a direct current voltage from the direct current power supply means into a high frequency voltage and applying the high voltage discharge lamp to light;
Lamp voltage detecting means for detecting a lamp voltage of the high-pressure discharge lamp;
Lamp power detection means for detecting lamp power of the high-pressure discharge lamp;
It has a function of controlling the direct current voltage from the direct current power source means and the operating frequency of the inverter means, and at the time of acoustic resonance determination due to a rise in lamp voltage after starting the lamp, the operating frequency of the inverter means is increased to a predetermined value. By detecting the change in the lamp voltage while moving each time, a stable lighting state is found to avoid the occurrence of an acoustic resonance phenomenon, and the lamp power is controlled by controlling the DC voltage from the DC power supply means. When the operating frequency of the inverter means reaches the end of the predetermined range (maximum value), the lamp power is controlled by controlling the DC voltage from the DC power supply means. Control means for performing a first control for lowering and a second control for lowering the operating frequency of the inverter means thereafter ;
A high-pressure discharge lamp lighting device comprising: A high pressure discharge lamp lighting device according to any one of claims 1 to 5;
A high pressure discharge lamp to be lit by the high pressure discharge lamp lighting device;
An instrument body to which the high-pressure discharge lamp is mounted;
An illumination device comprising:

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