JP2010044980A - Lighting device for discharge lamp, and illumination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid an incorrect detection and an incorrect operation due to the effect of switching noises in a taking-in operation of a plurality of detection data according to the operating state of a discharge lamp. <P>SOLUTION: The discharge lamp lighting device is provided with a lighting means 3 including switching means 3 Q2-Q6 to control lighting of a discharge lamp DL, a plurality of detection means to detect a plurality of factors (Vt, Vla etc.) relating to the operating state of the discharge lamp DL which is lighting controlled by the lighting means 3, a taking-in means (A/D conversion etc.) to convert the detected signal from each detection means into digital detection data and take in them, a signal processing means (averaging processing etc.) to carry out a prescribed calculation processing to the detection data collected, and a change control means which changes at least one of the taking-in operation of the detected signal by the taking-in means or the calculation processing by the signal processing means according to the operating state of the discharge lamp DL. The detected signal is collected by the taking-in means in a timing excluding the moment when the switching means Q2-Q6 are turned on and off. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a discharge lamp lighting device and a lighting fixture using the same.

In Patent Document 1 (Japanese Patent Laid-Open No. 2002-175992), a plurality of detection means for detecting a plurality of elements related to the operating state of a discharge lamp controlled by a discharge lamp lighting circuit and detection from each detection means are disclosed. A capturing means for converting a signal into digital detection data, a signal processing means for obtaining calculation data from the acquired detection data in accordance with a predetermined processing method, and a discharge from the discharge lamp lighting circuit from the calculation data. Calculating means for obtaining control data for controlling the output supplied to the electric lamp; at least one of the detection signal capturing operation in the capturing means and the processing method in the signal processing means in accordance with the operating state of the discharge lamp; A discharge lamp lighting device that enables removal of noise as much as possible and high-speed processing of discharge lamp control by providing a change control means for changing .
Japanese Patent Application Laid-Open No. 2002-175992

  In the conventional technique, since the detection timing also includes the ON / OFF moment of the switching element that is said to generate the most noise in the discharge lamp lighting circuit, it is difficult to say that the malfunction does not occur reliably.

  The present invention has been made in view of the above-described points, and is capable of reliably preventing malfunctions by linking a plurality of detection data fetching operations according to the operating state of the discharge lamp with on / off of the switching elements. An object of the present invention is to provide an accurate discharge lamp lighting device.

  In order to solve the above problems, the invention of claim 1 is controlled by the lighting means 3 including switching means Q2 to Q6 for controlling the lighting of the discharge lamp DL, and the lighting means 3 as shown in FIG. A plurality of detecting means for detecting a plurality of elements (Vt, Vla, etc.) related to the operating state of the discharge lamp DL, and a capturing means for converting the detection signal from each detecting means into digital detection data (A / D conversion, etc.), signal processing means (such as an averaging process) for performing predetermined arithmetic processing on the captured detection data, and the detection signal at the capture means according to the operating state of the discharge lamp DL Change control means for changing at least one of the capture operation or the arithmetic processing in the signal processing means, and at a timing excluding the moment when the switching means is turned on or off, It is characterized in that the capturing detection signal by write means.

  According to a second aspect of the present invention, in the first aspect of the invention, the timing excluding the moment when the switching means is turned on or off is, as shown in FIG. 4, FIG. 5 or FIG. It is characterized by being on or off.

  According to a third aspect of the present invention, in the first aspect of the invention, the timing excluding the moment when the switching means is turned on or off is when all of the switching means Q2 to Q6 are off as shown in FIG. It is characterized by being.

  According to a fourth aspect of the present invention, in the first to third aspects of the present invention, as shown in FIGS. 9 to 12, the change control means switches the switching means that changes with the discharge lamp voltage after the discharge lamp is turned on. The period of capturing by the capturing unit is changed according to the frequency or duty.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the invention, the change control means switches the switching means that changes with the discharge lamp voltage after the discharge lamp is turned on, as shown in FIGS. The number of times of capturing by the capturing means is changed according to frequency or duty.

  According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, as shown in FIG. 10, the signal processing means performs a simple average process or a weighted average process on the detection data captured by the capture means. Or simple average processing of data obtained by removing some read data.

  The invention of claim 7 is the invention of claims 1 to 6, wherein the signal processing means has an abnormal state determination means as shown in FIG. The output of the lighting means is reduced or stopped.

  The invention of claim 8 is characterized in that, in the invention of claim 7, as shown in FIG. 10, the abnormal state is a high temperature abnormality.

  According to a ninth aspect of the present invention, in the first to eighth aspects of the present invention, as shown in FIG. 1, at least one switching that converts the output of the DC power source 2 into a predetermined power to be supplied to the discharge lamp DL of the load is used. A power conversion circuit 6 having means Q2, and a polarity inversion circuit 7 having at least one switching means Q3 to Q6 for converting the output of the power conversion circuit 6 into a predetermined rectangular wave AC power and applying it to the discharge lamp DL; In a discharge lamp lighting device comprising a start pulse generation circuit 8 for applying a start high voltage pulse voltage to the discharge lamp DL, a plurality of elements (Vt, Vla, etc.) relating to the operating state of the discharge lamp DL are detected. A plurality of detection means, a capture means (A / D conversion or the like) for converting the detection signal from each detection means into digital detection data and taking in the signal, and a signal for performing predetermined arithmetic processing on the taken detection data And a change control means for changing at least one of the detection signal capturing operation in the capturing means or the arithmetic processing in the signal processing means in accordance with the operating state of the discharge lamp DL. The detection signal is captured by the capture means at a timing excluding the moment when the switching means is turned on or off.

  The invention of claim 10 is a lighting fixture comprising the discharge lamp lighting device according to any one of claims 1 to 9 (FIG. 13).

  According to the present invention, since the detection signal is captured by the capture means at timings other than the moment when the switching means is turned on or off, the detection data can be captured without being affected by the switching noise. It is possible to realize a discharge lamp lighting device that can prevent malfunction due to detection and can be stably lit.

(Embodiment 1)
FIG. 1 shows a circuit diagram of a lighting device according to Embodiment 1 of the present invention. In the figure, 1 is an AC power supply, 2 is a DC power supply circuit, and 3 is a power conversion circuit. The DC power supply circuit 2 includes a rectifier DB for full-wave rectification of the AC power supply 1, a step-up chopper circuit including an inductor L 1, a switching element Q 1, a diode D 1, and a capacitor C 1, and a control circuit 5 thereof. Is converted into a DC output and supplied to the power conversion circuit 3, and power factor improvement control is performed so that the circuit has resistance so that the phase of the input current and the input voltage is not shifted. For example, it is realizable by using a commercially available integrated circuit (MC33262 etc.) as the control circuit 5 of the switching element Q1.

  The power conversion circuit 3 includes a step-down chopper circuit 6, an inverter circuit 7, an igniter circuit 8, and a control circuit 9. The step-down chopper circuit 6 includes a switching element Q2, a diode D2, an inductor L2, and a capacitor C2. The step-down chopper circuit 6 is a circuit that outputs a DC voltage obtained by stepping down the input voltage. The step-down chopper circuit 6 controls the on / off state of the switching element Q2. It is used as a ballast that adjusts the power supplied to the DL.

  The step-down chopper circuit 6 controls on / off of the switching element Q2 by the PWM signal from the control circuit 9. Specifically, when the switching element Q2 is turned on by a command from the control circuit 9, a current starts to flow through the inductor L2. When the current detection value Ip of the switching element Q2 detected from the resistor R2 reaches the current target value, the switching element Q2 is turned OFF. Thereafter, when it is detected that the zero cross signal ZCS becomes zero by the secondary winding of the inductor L2, the ON signal of the switching element Q2 is output, and thereafter the same operation as described above is repeated.

  The inverter circuit 7 constitutes a full bridge circuit composed of switching elements Q3 to Q6. This inverter circuit 7 has a pair of switching elements Q3 and Q6 and a pair of Q4 and Q5 that are alternately turned on at a low frequency of several tens to several hundreds of Hz by a control signal from the control circuit 9, thereby Supply square wave AC power.

  The igniter circuit 8 includes a pulse transformer PT connected between one end of the high pressure discharge lamp DL and a connection point between the switching elements Q3 and Q4, a capacitor C3 inserted between an intermediate tap of the pulse transformer PT and the ground, and a resistor R1. It is comprised by the resonant booster circuit which consists of a serial circuit.

  The control circuit 9 detects the lamp voltage Vla of the discharge lamp DL, the lamp current Ila, the peak current Ip of the switching element Q2, and the zero cross signal (ZCS) of the current flowing through the inductor L2, and the switching element Q2 according to these detection results. The switching element Q2 of the step-down chopper circuit 6 and the switching elements Q3 to Q6 of the inverter circuit 7 are controlled so as to supply a desired current or power to the discharge lamp DL. The control circuit 9 includes, for example, a microcomputer ST72215 (manufactured by ST).

  The control circuit 9 may be constituted by a one-chip microcomputer, but an operational amplifier for detecting the lamp current Ila and the chopper current Ip, a voltage dividing resistor circuit for detecting the lamp voltage Vla, or each switching element Q2. An input / output circuit such as a driving circuit of .about.Q6 may be externally attached to the microcomputer.

  The discharge lamp DL is a high-intensity high-pressure discharge lamp (HID lamp) such as a metal halide lamp or a high-pressure mercury lamp.

  By using this circuit, the lighting device goes through the following three processes until the high pressure discharge lamp reaches the stable lighting state from the no-load (non-point) state.

  No-load mode: The discharge lamp DL is in an astigmatic state and is generated by alternately turning on / off the switching elements Q3 and Q4 in the vicinity of the LC resonance frequency of the primary winding N1 of the transformer PT and the capacitor C3 constituting the resonance circuit. The resonant pulse voltage is boosted by the turns ratio (N2 / N1) of the transformer PT and applied between the lamp electrodes, thereby causing the discharge lamp DL to break down and shift to the starting mode.

  Start-up mode: When the discharge lamp DL breaks down due to the resonance pulse voltage, an arc discharge occurs through a glow discharge. In the process from the start of the arc discharge until the temperature in the arc tube is uniformized and stabilized, the lamp voltage Vla gradually increases from several V to a stable voltage over several minutes.

  Stable lighting mode: A few minutes after the lighting of the discharge lamp DL, the temperature in the arc tube of the discharge lamp DL rises to a stable state, and the lamp voltage Vla becomes substantially constant.

  The control circuit 9 periodically reads the output data Vt of the temperature sensor IC 10 for abnormal temperature protection (for example, LM50 (manufactured by NS)) 10 at least in the stable lighting mode, and the average value of the data acquired a plurality of times is When the threshold value is exceeded, it is determined that the temperature is abnormally high, and the operation of the power conversion circuit 3 is stopped or reduced.

  The difference from the prior art is that the control circuit 9 controls the capture timing of detection elements (such as temperature detection data Vt) related to the operating state according to the switching state of the switching elements Q2 to Q6 in the step-down chopper circuit 6 and the inverter circuit 7. I am doing it. Hereinafter, the operation of the power conversion circuit 3 (however, the no-load mode and the start mode are omitted, and only the stable lighting mode) will be described in detail.

  When shifting to the stable lighting mode, as shown in FIG. 2, a period T21 in which the switching elements Q3 and Q6 are ON and the switching elements Q4 and Q5 are OFF, and a period in which the switching elements Q4 and Q5 are ON and the switching elements Q3 and Q6 are OFF T22 is provided, and these periods T21 and T22 alternate with a period of a low frequency of several hundred Hz.

  With the above operation, as shown in FIG. 2, a low-frequency rectangular wave lamp current Ila is stably supplied to the discharge lamp DL, and the discharge lamp DL is lit with desired power controlled by the step-down chopper circuit 6.

  As shown in FIG. 2, the microcomputer in the control circuit 9 detects that all of the switching elements Q2 to Q6 are turned off, and immediately after the turning off, for example, a temperature sensor for abnormal temperature protection shown in FIG. The data Vt output from the IC 10 is read at least once. When all the switching elements Q2 to Q6 are turned off next time, the microcomputer in the control circuit 9 reads the data Vt at least once in the same manner as described above. A plurality of detection data is read by repeating the above operation a plurality of times. This prevents the microcomputer receiving the output of the temperature sensor IC 10 from recognizing an abnormal temperature at a temperature lower than a predetermined temperature due to the influence of noise.

  Further, not only the temperature but also a plurality of detection elements such as the lamp voltage Vla and the lamp current Ila can be similarly applied. In addition, a control circuit that brings about the same effect can be configured with an analog circuit instead of a microcomputer.

  As described above, the detection data can be read without being affected by the switching noise, so that it is possible to realize a high pressure discharge lamp lighting device that can prevent malfunction due to erroneous detection and can be stably lit.

(Embodiment 2)
FIG. 3 is a circuit diagram of Embodiment 2 of the present invention, and FIGS. 4 and 5 are operation waveform diagrams thereof. In the present embodiment, the full bridge inverter circuit 7 is used as the power conversion circuit, and the functions of the step-down chopper circuit 6, the inverter circuit 7, and the igniter circuit 8 of the first embodiment are controlled by skillfully controlling the switching elements Q3 to Q6. Are shared by one circuit. That is, when no load is applied, the switching elements Q3 and Q4 are alternately turned on and off at a high frequency, so that the resonant booster circuit including the transformer PT and the intermediate tap of the transformer PT and the capacitor C3 inserted between the ground generates a high voltage. And the dielectric breakdown of the discharge lamp DL. During start-up to stable lighting, the switching elements Q3 and Q4 are alternately turned on and off at a low frequency so that the resonant booster circuit stops generating a high voltage. The operation of turning on and off at a high frequency and the operation of turning on and off the switching element Q6 at a high frequency in a period T22 during which the switching element Q3 is on are alternated at a low frequency, thereby generating a low-frequency rectangular wave voltage at the discharge lamp DL. To supply. At this time, the inductor L2 and the capacitor C2 function as a low-pass filter of the step-down chopper circuit.

  The control circuit 9 detects the lamp voltage Vla from the lamp both-end voltages Vla1 and Vla2, and detects the instantaneous value Ip of the chopper current flowing through the switching elements Q5 and Q6 by the current detection resistor R2. Further, the detection circuit 11 detects the zero cross signal ZCS of the current flowing through the inductor L2, and controls the switching elements Q3 to Q6 so as to supply a desired current or power determined from these detection results to the lamp.

  When the high-pressure discharge lamp reaches from the no-load (unstable) state to the stable lighting state using the above circuit, the lighting device is roughly divided into the following three processes.

  No-load mode: The discharge lamp DL is in an astigmatic state, and is generated by alternately turning on / off the switching elements Q3 and Q4 in the vicinity of the LC resonant frequency of the primary winding of the transformer PT and the capacitor C3 constituting the resonant booster circuit. The resonant pulse voltage is boosted at the turn ratio of the transformer PT and applied between the lamp electrodes, whereby the lamp is dielectrically broken to shift to the starting mode.

  Start-up mode: When the discharge lamp DL breaks down due to the resonance pulse voltage, an arc discharge occurs through a glow discharge. In the process from the start of the arc discharge until the temperature in the arc tube is uniformized and stabilized, the lamp voltage Vla gradually increases from several V to a stable voltage over several minutes.

  Stable lighting mode: A few minutes after the lighting of the discharge lamp DL, the temperature in the arc tube of the discharge lamp DL rises to a stable state, and the lamp voltage Vla becomes substantially constant.

  At least in the stable lighting mode, the control circuit 9 periodically reads the output data Vt of the temperature sensor IC 10 (for example, LM50 (manufactured by NS)) 10 for protecting the abnormal temperature, and the average value of the data acquired a plurality of times is When the threshold value is exceeded, it is determined that the temperature is abnormally high, and the output of the inverter circuit 7 is stopped or lowered.

  The difference from the prior art is that the control circuit 9 controls the timing of fetching data related to the operating state in accordance with the switching state of the switching elements Q3 to Q6 in the inverter circuit 7.

Hereinafter, the operation of the inverter circuit 7 (only in the stable lighting mode) will be described in detail.
When shifting to the stable lighting mode, as shown in FIG. 4 or 5, the switching element Q4 is ON, the switching elements Q3 and Q6 are OFF, and the switching element Q5 is ON / OFF operation at a high frequency of several tens to several hundreds kHz. Period T21 during which the switching element Q3 is ON and the switching elements Q4 and Q5 are OFF, and the switching element Q6 is ON / OFF operated at a high frequency of several tens to several hundreds kHz, and these periods T21 are provided. T22 alternates with a low frequency period of several tens to several hundreds of Hz.

  With the above operation, a low-frequency rectangular wave lamp current Ila as shown in FIG. 4 or FIG. 5 is stably supplied to the discharge lamp DL, and the discharge lamp DL is lit with desired power.

  Further, as shown in FIG. 4, in response to the switching elements Q4 and Q5 being turned on in the period T21, the microcomputer in the control circuit 9 immediately after the switching element Q5 is turned on, for example, for abnormal temperature protection shown in FIG. The data Vt output from the temperature sensor IC 10 is read at least once. When the switching element Q5 is turned on again, the microcomputer in the control circuit 9 reads the data Vt at least once in the same manner as described above. By repeating the above operation a plurality of times, a plurality of detection data are read. Alternatively, the switching element Q5 can be turned ON / OFF by reading the output data Vt at a period t (every several microseconds) equal to the period of the switching element Q5 starting immediately after the switching element Q5 is turned ON for the first time in the T21 period. It is possible to avoid reading at the timing when switching noise occurs at the moment.

In contrast to the above, it goes without saying that the output data Vt can be read in response to the switching element Q5 being turned off as shown in FIG.
Needless to say, the same can be done in the T22 period.

  This prevents the control circuit receiving the output of the temperature sensor IC from recognizing an abnormal temperature at a temperature lower than a predetermined temperature due to the influence of switching noise. Further, not only the temperature but also a plurality of other detection elements can be similarly applied. In addition, a control circuit that brings about the same effect can be configured with an analog circuit instead of a microcomputer.

  As described above, the detection data can be read without being affected by the switching noise, so that it is possible to realize a high pressure discharge lamp lighting device that can prevent malfunction due to erroneous detection and can be stably lit.

(Experimental data)
FIG. 6 shows the output Vt from the temperature sensor IC, the lamp current Ila, and the drain current Id of the switching element for the chopper with actual waveforms. In FIG. 2, the data of all off period A at the time of polarity reversal, the data of on period B in FIG. 4 and the data in off period C in FIG. 5 are read.

  As shown in FIG. 6, it can be seen that noise appears on the output Vt from the temperature sensor IC at the moment when the switching element for chopper is turned ON / OFF. On the other hand, in other periods, other noise elements are conceivable, but it can be seen that there is no noise that is likely to greatly affect data reading.

(Embodiment 3)
FIG. 7 is a circuit diagram of Embodiment 3 of the present invention, and FIG. 8 is an operation waveform diagram thereof. In the present embodiment, a half bridge inverter circuit is used as the power conversion circuit 3. In this half-bridge inverter circuit, a series circuit of electrolytic capacitors C1, C2 and a series circuit of switching elements Q2, Q3 are connected in parallel to the output of the DC power supply circuit 2, and a connection point between the capacitors C1, C2 and switching elements Q2, Q3 are connected. A series circuit of a capacitor C4 and an inductor L2 is connected between the connection points, and a discharge lamp DL is connected in parallel with the capacitor C4 via the secondary winding N2 of the pulse transformer PT. Embodiment 1 The function of the step-down chopper circuit 6 and the inverter circuit 7 is shared. The series circuit of the inductor L2 and the capacitor C4 constitutes a low-pass filter circuit for a step-down chopper, and a period T1 in which the switching element Q2 is turned on / off at a high frequency of several tens to several hundreds of kHz by a control signal of the control circuit 9, A low-frequency rectangular wave voltage is obtained at both ends of the capacitor C4 by alternating the period T2 when the switching element Q3 is turned on / off at a high frequency of several tens to several hundreds of kHz at a low frequency of several tens to several hundreds of Hz. ing.

  The control circuit 9 detects the lamp voltage Vla from one end of the discharge lamp DL, detects the current flowing through the switching elements Q2 and Q3 by a current transformer or the like, and the zero cross signal (ZCS) of the current flowing through the inductor L2 by the zero cross detection circuit 11 And the switching elements Q2 and Q3 are controlled based on the detection results.

  The igniter circuit 8 includes a pulse transformer PT, a capacitor C3, a switching element Q7 (for example, a voltage response element such as Sidac), and a resistor R1. The igniter circuit 8 is connected to the output of the DC power supply circuit 2 via a switch element Q8 that is controlled to be opened and closed by a control signal from the control circuit 9. When the switch element Q8 is ON, the voltage of the DC power supply circuit 2 is received, and the capacitor C3 is gradually charged by the time constant of the resistor R1 and the capacitor C3. When no voltage is applied, when the voltage Vc3 of the capacitor C3 reaches the breakover voltage Vbo of the switching element Q7, the switching element Q7 is turned on, and the charge accumulated in the capacitor C3 is changed to the primary of the capacitor C3 → the switching element Q7 → the pulse transformer PT. Discharge through winding N1. At this time, the pulse voltage generated in the primary winding N1 of the pulse transformer PT is boosted, and a high voltage pulse voltage (several KV) is generated in the secondary winding N2 of the pulse transformer PT. And the discharge lamp DL starts discharge by this high voltage | pressure pulse voltage, and transfers to a lighting state.

  By using this circuit, the lighting device is roughly divided into the following three processes until the high pressure discharge lamp reaches a stable lighting state from a no-load (non-point) state.

  No-load mode: The discharge lamp DL is in an astigmatic state, and the pulse voltage generated by the igniter circuit 8 is boosted from the primary winding N1 to the secondary winding N2 of the transformer PT and superimposed on the rectangular wave voltage. By applying the voltage between the lamp electrodes, the dielectric breakdown of the discharge lamp DL is performed to shift to the start mode.

  Start mode: When the discharge lamp DL breaks down due to the pulse voltage, the arc discharge is caused through glow discharge. In the process from the start of the arc discharge until the temperature in the arc tube is uniformized and stabilized, the lamp voltage Vla gradually increases from several V to a stable voltage over several minutes.

  Stable lighting mode: A few minutes after the lighting of the discharge lamp DL, the temperature in the arc tube of the discharge lamp DL rises to a stable state, and the lamp voltage Vla becomes almost constant.

  At least in the stable lighting mode, the control circuit 9 periodically reads the output data Vt of the temperature sensor IC 10 (for example, LM50 (manufactured by NS)) 10 for protecting the abnormal temperature, and the average value of the data acquired a plurality of times is When the threshold value is exceeded, it is determined that the temperature is abnormally high, and the output of the inverter circuit 7 is stopped or lowered.

  The difference from the prior art is that the control circuit 9 controls the timing of fetching data related to the operating state in accordance with the switching state of the switching elements Q2 and Q3.

Hereinafter, the operation of the power conversion circuit 3 (only in the stable lighting mode) will be described in detail.
When shifting to the stable lighting mode, as shown in FIG. 8, the negative DC current Ila is supplied to the discharge lamp DL by turning on / off the switching element Q2 at a high frequency while the switching element Q3 remains OFF during the operation period T1. The Further, in the operation period T2, the switching element Q3 is turned on / off at a high frequency while the switching element Q2 is turned off, so that a positive DC current Ila is supplied to the discharge lamp DL. With the above operation, the low-frequency rectangular wave lamp current Ila shown in FIG. 8 is stably supplied to the discharge lamp DL, and the discharge lamp DL is lit with desired power.

  Further, as shown in FIG. 8, in response to the switching element Q2 being turned on during the period T1, the microcomputer in the control circuit 9 immediately after the switching element Q2 is turned on, for example, the temperature for abnormal temperature protection shown in FIG. The data Vt output from the sensor IC 10 is read at least once. Even when the switching element Q2 is turned off, the microcomputer in the control circuit 9 reads the data Vt output from the temperature sensor IC 10 for protecting the abnormal temperature immediately after the switching element Q2 is turned off at least once. When the switching element Q2 is turned on again and turned off, the microcomputer in the control circuit 9 reads the data Vt at least once in the same manner as described above. A plurality of detection data is read by repeating the above operation a plurality of times. Alternatively, the switching noise at the ON / OFF instant can be read by reading the output data Vt at a cycle (every several microseconds) equivalent to the half cycle of the switching device Q2 starting from immediately after the switching device Q2 is turned on for the first time in the T1 period. It is possible to avoid reading at the timing when appears.

Needless to say, the same can be done during the period T2.
In addition, a control circuit that provides the same effect can be configured with an analog circuit instead of a microcomputer.

  This prevents the control circuit receiving the output of the temperature sensor IC from recognizing an abnormal temperature at a temperature lower than a predetermined temperature due to the influence of noise. Further, not only the temperature but also a plurality of other detection elements can be similarly applied.

  As described above, the detection data can be read without being affected by the switching noise, so that it is possible to realize a high pressure discharge lamp lighting device that can prevent malfunction due to erroneous detection and can be stably lit.

(Embodiment 4)
FIG. 9 is a waveform diagram for explaining the operation of the fourth embodiment of the present invention, and FIG. 10 is a flowchart showing the operation of the main part. The circuit configuration is the same as in the first embodiment. In the present embodiment, in the stable lighting mode, the lamp voltage Vla is detected after polarity inversion, and the sampling period or the number of samplings is determined by the table of FIG. 11 or FIG. When it is detected that the switching element Q2 of the step-down chopper circuit 6 is turned off, the data Vt of the temperature sensor IC is read every several microseconds. The reading period and the number of readings are the period and the number of times determined by the table of FIG. 11 or FIG. When a plurality of data Vt is acquired in this way, an averaged temperature detection data Vt is obtained by performing an averaging process. The average value is compared with a predetermined threshold value, and if the temperature is abnormally high, the output of the power conversion circuit 3 is reduced or stopped to protect the circuit. If the temperature is not abnormal, continue normal operation.

  The difference from the prior art is that the control circuit 9 controls the timing of fetching data related to the operating state in accordance with the switching state of the switching elements Q2 to Q6 of the power conversion circuit 3. Hereinafter, the operation of the power conversion circuit 3 (only in the stable lighting mode) will be described in detail.

  When shifting to the stable lighting mode, as shown in FIG. 9, a period T21 in which switching elements Q3 and Q6 are ON and switching elements Q4 and Q5 are OFF, and a period in which switching elements Q4 and Q5 are ON and switching elements Q3 and Q6 are OFF T22 is provided, and these periods T21 and T22 alternate with a period of a low frequency of several hundred Hz.

  With the above operation, the low-frequency rectangular wave lamp current Ila shown in FIG. 2 is stably supplied to the high-pressure discharge lamp DL, and the high-pressure discharge lamp DL is lit with desired power controlled by the step-down chopper circuit 6.

  Further, as shown in FIG. 9, the microcomputer in the control circuit 9 detects that the switching elements Q4 and Q5 are ON and the switching elements Q3 and Q6 are OFF during the period T22, and at that time, the step-down chopper circuit 6 Output voltage (= Vla) is detected and read by the microcomputer. Then, a sampling period (or sampling) for reading detection data from the detected ramp voltage Vla based on a table of the ramp voltage Vla and the sampling period (or sampling number) as shown in FIG. 11 or FIG. 12 pre-programmed in the microcomputer. Number of times).

  Thereafter, immediately after the switching element Q2 is turned OFF, the data Vt output from, for example, a temperature sensor IC (for example, LM50 (manufactured by NS)) shown in FIG. 1 is read according to the sampling period (or the number of times of sampling). Specifically, an analog voltage corresponding to the detected temperature output from the temperature sensor IC is read as digital data using the A / D conversion function of the microcomputer.

  A plurality of read data Vt may be subjected to a simple average process, may be subjected to a weighted average process, or may be subjected to a simple average process on data obtained by removing a part of the read data. As a specific example of removing a part of the read data, the maximum value or the minimum value may be removed, or data that is extremely different from other data may be removed as noise. These signal processes may be changed according to the lamp voltage Vla, the lamp current Ila, the lamp power, the elapsed time after lighting, and the like.

  The table of the lamp voltage Vla and the sampling period (or the number of sampling times) is effective when the switching frequency and the duty of the switching element Q2 are designed to be different depending on the lamp voltage Vla of the high pressure discharge lamp lighting device. In the example of FIG. 9, the switching frequency is set to be different for each lamp voltage Vla.

  Needless to say, the same can be done in the T21 period.

  This prevents the microcomputer receiving the output of the temperature sensor IC from recognizing an abnormal temperature at a temperature lower than a predetermined temperature due to the influence of switching noise. Further, not only the temperature but also a plurality of detection elements can be similarly applied. In addition, a control circuit that brings about the same effect can be configured with an analog circuit instead of a microcomputer.

  As described above, the detection data can be read without being affected by the switching noise, so that it is possible to realize a high pressure discharge lamp lighting device that can prevent malfunction due to erroneous detection and can be stably lit.

(Embodiment 5)
FIG. 13 shows a configuration example of a lighting fixture using the high pressure discharge lamp lighting device of the present invention. (A), (b) is an example using an HID lamp as a spotlight, and (c) is an example using an HID lamp as a downlight. In the figure, DL is a high pressure discharge lamp, 81 is a high pressure discharge lamp. A mounted lamp body, 82 is a wiring, and 83 is a ballast storing a circuit of a lighting device. A lighting system may be constructed by combining a plurality of these lighting fixtures.

It is a circuit diagram of Embodiment 1 of the present invention. It is a wave form diagram for operation | movement description of Embodiment 1 of this invention. It is a circuit diagram of Embodiment 2 of the present invention. It is a wave form diagram for explanation of operation of Embodiment 2 of the present invention. It is a wave form diagram for explanation of operation of Embodiment 2 of the present invention. It is a wave form diagram for operation check of Embodiment 1 and Embodiment 2 of the present invention. It is a circuit diagram of Embodiment 3 of the present invention. It is a wave form diagram for description of operation | movement of Embodiment 3 of this invention. It is a wave form diagram for operation | movement description of Embodiment 4 of this invention. It is a flowchart which shows operation | movement of Embodiment 4 of this invention. It is operation | movement explanatory drawing of Embodiment 4 of this invention. It is operation | movement explanatory drawing of Embodiment 4 of this invention. It is a perspective view which shows the lighting fixture of Embodiment 5 of this invention.

Explanation of symbols

2 DC power supply circuit 3 Power conversion circuit 6 Step-down chopper circuit 7 Inverter circuit 8 Igniter circuit 9 Control circuit 10 Temperature sensor IC
DL discharge lamp

Claims (10)

Lighting means including switching means for controlling lighting of the discharge lamp;
A plurality of detection means for detecting a plurality of elements related to the operating state of the discharge lamp controlled to be turned on by the lighting means;
Capture means for converting the detection signal from each detection means into digital detection data and taking it in;
Signal processing means for performing predetermined arithmetic processing on the captured detection data;
Change control means for changing at least one of the detection signal capture operation in the capture means or the arithmetic processing in the signal processing means according to the operating state of the discharge lamp,
A discharge lamp lighting device characterized in that a detection signal is captured by the capture means at a timing excluding the moment when the switching means is turned on or off. The discharge lamp lighting device according to claim 1, wherein the timing excluding the moment when the switching means is turned on or off is when at least one of the switching means is turned on or off. 2. The discharge lamp lighting device according to claim 1, wherein the timing excluding the moment when the switching means is turned on or off is when all the switching means are turned off. The said change control means changes the period taken in by the said taking-in means according to the switching frequency or duty of the said switching means which changes with the discharge lamp voltage after lighting a discharge lamp, The 1st thru | or characterized by the above-mentioned. 4. The discharge lamp lighting device according to any one of 3. The change control means changes the number of times of taking-in by the taking-in means according to the switching frequency or duty of the switching means that changes with the discharge lamp voltage after the discharge lamp is turned on. 5. The discharge lamp lighting device according to any one of 4 above. The signal processing means performs a simple average process or a weighted average process on detection data captured by the capture means, or a simple average process on data obtained by removing a part of read data. The discharge lamp lighting device according to any one of 1 to 5. 7. The signal processing unit according to claim 1, further comprising: an abnormal state determination unit that reduces or stops the output of the lighting unit when the abnormal state determination unit determines that there is an abnormality. The discharge lamp lighting device described. The discharge lamp lighting device according to claim 7, wherein the abnormal state is a high temperature abnormality. A power conversion circuit comprising at least one switching means for converting the output of a direct current power source into a predetermined power to be supplied to a discharge lamp of a load;
A polarity inversion circuit comprising at least one switching means for converting the output of the power conversion circuit into a predetermined rectangular wave AC power and applying it to the discharge lamp;
In a discharge lamp lighting device comprising a start pulse generating circuit for applying a high voltage pulse voltage for start to a discharge lamp,
A plurality of detection means for detecting a plurality of elements related to the operating state of the discharge lamp;
Capture means for converting the detection signal from each detection means into digital detection data and taking it in;
Signal processing means for performing predetermined arithmetic processing on the captured detection data;
Change control means for changing at least one of the detection signal capture operation in the capture means or the arithmetic processing in the signal processing means according to the operating state of the discharge lamp,
The discharge lamp lighting device according to any one of claims 1 to 8, wherein a detection signal is captured by the capturing unit at a timing excluding a moment when the switching unit is turned on or off. A lighting fixture comprising the discharge lamp lighting device according to any one of claims 1 to 9.

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