JP2005222893A - Discharge lamp lighting device and luminaire using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of preventing lighting of a discharge lamp from starting, by detecting a failure of filament parts connected in series. <P>SOLUTION: This discharge lamp lighting device is provided with a no load detecting circuit 109 to prevent lighting of the discharge lamp from starting when a failure in filaments F2, F3 forming the filament parts connected in series, poles 3, 4, and a connected part 7 is detected, when a power supply is applied, a filament failure detecting circuit 108 to stop supplying power for lighting when the failure of the filament parts connected in series is detected after starting the power supply for lighting to the discharge lamps FL2, FL3, and a dc voltage source 115 to start power supply for operation to the filament failure detecting circuit 108 after the power supply for lighting starts, so as to prevent the operation of the no load detecting circuit 109 from being impeded by a wrap-around current from the filament failure detecting circuit 108 to the no load detecting circuit 109. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device that emits light from a discharge lamp by supplying electric power, and a lighting fixture using the same.

  FIG. 11 is a circuit diagram showing a configuration of a discharge lamp lighting device according to the background art. In the discharge lamp lighting device shown in FIG. 11, an unillustrated power supply unit that generates a DC voltage Vdc, a series circuit including switching elements of a transistor Q1 and a transistor Q2 to which the DC voltage Vdc is applied, and transistors Q1 and Q2 are alternately arranged. A control circuit unit 201 that generates a rectangular wave voltage at a connection point between the transistors Q1 and Q2 by being turned on and off is provided. The connection point between the transistors Q1 and Q2 is connected to one pole (1) of the filament F1 of the discharge lamp FL1 through a parallel circuit of a DC component cutting capacitor C1 and a resistor R5 and a resonance transformer T1. Has been.

  The control circuit unit 201 responds to the control signals from the comparators 202 and 203, the inverter control circuit 204 that outputs a control signal to alternately turn on and off the transistors Q1 and Q2 in a predetermined cycle, and the control signal from the inverter control circuit 204. And a drive circuit 205 for turning on and off the transistors Q1 and Q2. The inverter control circuit 204 supplies power to the discharge lamps FL1 and FL2 by turning on and off the transistors Q1 and Q2 when the output signal VNL of the comparator 202 is high and the output signal VEL of the comparator 203 is low. On the other hand, when the signal VNL is at a low level or the signal VEL is at a high level, the transistors Q1 and Q2 are turned off to stop the power supply to the discharge lamps FL1 and FL2.

  Further, the DC voltage Vdc is supplied to the other pole (2) of the filament F1 through the resistor R11. The DC voltage Vdc is supplied to the ground through a series circuit of a parallel circuit of a resistor R11, a resistor R3, and a resistor R4 and a capacitor C9, and a connection point between the resistor R3 and the resistor R4 is connected via a diode D3. Connected to the non-inverting input terminal of the comparator 203.

  The connection point between the capacitor C1 and the resonance transformer T1 is connected to the ground via a resistor R1 and a series circuit of a parallel circuit of the resistor R2 and the capacitor C7, and the connection point between the resistor R1 and the resistor R2 is a diode. It is connected to the non-inverting input terminal of the comparator 203 via D1. The filament F2 on the opposite side of the filament F1 of the discharge lamp FL1 and the filament F3 of the discharge lamp FL2 are connected in series at the connection portion (7) to form a discharge lamp series circuit by the discharge lamps FL1 and FL2. The discharge lamp series circuit and the resonance capacitor C2 are connected in parallel.

  The DC voltage Vdc is connected to the ground via resistors R8, R9, and R10, a capacitor C8 is connected in parallel to the resistor R10, and the connection point between the resistors R9 and R10 is connected to the comparator 203 via the diode D2. Connected to non-inverting input terminal. A series circuit of a resistor R6 and a capacitor C4 is connected in parallel to the resistor R8. And the connection point of resistance R8, R9 and the capacitor | condenser C4 is connected with the pole (3) on the opposite side to the connection part (7) in the filament F2. Moreover, the pole (4) on the opposite side to the connection part (7) in the filament F3 is connected to the connection point of the resistors R9 and R10 via the resistor R7. The resistors R6, R7, R8, R9, R10, the capacitor C8, and the comparator 203 constitute a filament defect detection circuit 206. The filament defect detection circuit 206 is activated when any one of the pole (3), the pole (4), and the connecting portion (7) is in a defective state such as disconnection or contact failure after the discharge lamps FL1 and FL2 are turned on. This is a circuit for turning off the lights FL1 and FL2.

  The DC voltage Vdc is connected to the ground via resistors R15, R16, and R17, and the connection point between the resistors R15 and R16 is the pole (5 in the filament F4 of the discharge lamp FL2 opposite to the filament F3). ). The capacitor C11 is connected in parallel with the resistor R17, the connection point between the resistor R17 and the capacitor C11 is connected to the base of the transistor Q3, the emitter of the transistor Q3 is connected to the ground, and the collector of the transistor Q3 is connected via the resistor R18. And connected to a connection point between the resistor R13 and the diode D4.

  The pole (1) is connected to the ground via resistors R12 and R13 and a reversely connected Zener diode ZD1, and a series circuit of a diode D4 and a resistor R14 is connected in parallel with the Zener diode ZD1, and the resistor R14 A capacitor C10 is connected in parallel, and a connection point between the diode D4 and the capacitor C10 is connected to the non-inverting input terminal of the comparator 202. The resistors R11, R12, R13, R14, the diode D4, the Zener diode ZD1, the capacitor C10, and the comparator 202 constitute a no-load detection circuit 207. The no-load detection circuit 207 is a circuit for turning off the discharge lamps FL1 and FL2 when there is a connection failure of the pole (1) or the pole (2) or a failure such as disconnection of the filament F1 at the time of startup. .

  The transformer T1 includes secondary windings 208, 209, and 210. One end of the secondary winding 208 is connected to the pole (1) via the capacitor C3, and the other end is connected to the pole (2). One end of the secondary winding 209 is connected to the pole (3) via the capacitor C4, and the other end is connected to the pole (4). One end of the secondary winding 210 is connected to the pole (5), and the other end is connected to the pole (6) opposite to the pole (5) in the filament F4 via the capacitor C5.

  The pole (1) to the pole (6) and the connecting portion (7) are constituted by, for example, a connector or the like, and the user can attach and detach the discharge lamps FL1 and FL2.

Next, operations of the filament defect detection circuit 206 and the no-load detection circuit 207 configured as described above will be described. First, in a normal state, when power is supplied from the outside to a power supply unit (not shown), the no-load detection circuit 207 generates a DC voltage Vdc from the power supply unit as a resistor R11, a filament F1, resistors R12 and R13, and a diode. The voltage is applied to the capacitor C10 via D4, and the charging voltage V _C10 of the capacitor C10 increases.

The charging voltage V _C10 of the capacitor C10 is compared with the reference voltage VrefN in the comparator 202. When the charging voltage V _C10 exceeds the reference voltage VrefN, the output signal VNL of the comparator 202 is output to the inverter control circuit 204 at a high level. Then, on / off operation of the transistors Q1 and Q2 is started by the inverter control circuit 204, power supply to the discharge lamps FL1 and FL2 is started, and the discharge lamps FL1 and FL2 are turned on.

On the other hand, in the filament defect detection circuit 206, the DC voltage Vdc is divided by the parallel circuit of the resistors R6 and R7 and the resistors R8 and R9 and the resistor R10, and the capacitor C8 is charged by the voltage across the resistor R10. However, since the discharge lamp FL2 is connected in parallel with the series circuit of the resistors R9 and R10, when the discharge lamps FL1 and FL2 are turned on, the impedance of the discharge lamp FL2 is reduced, and as a result, the capacitor C8 and the resistor R10 are connected in parallel. There is almost no voltage in the circuit. Therefore, the charging voltage V _C8 capacitor C8 is compared with a reference voltage VREFE in the comparator 203, since the charging voltage V _C8 does not exceed the reference voltage VREFE, output the output signal VEL of the comparator 203 to the inverter control circuit 204 at the low level Thus, the power supply to the discharge lamps FL1, FL2 is continued without being stopped.

Next, in the state where the discharge lamps FL1 and FL2 are lit, when a connection failure such as disconnection or contact failure occurs in the pole (3), the series circuit of the resistors R9 and R10 and the discharge lamp FL2 are connected in parallel. Therefore, the capacitor C8 is charged by the voltage determined by the voltage dividing ratio of the resistors R8, R9, and R10, the charge voltage V _C8 rises, and is compared with the reference voltage VrefE by the comparator 203, and the charge voltage V _C8 becomes equal to the reference voltage VrefE. The output signal VEL of the comparator 203 is output to the inverter control circuit 204 at a high level. Then, the inverter control circuit 204 stops the power supply to the discharge lamps FL1 and FL2, and the discharge lamps FL1 and FL2 are turned off.

Next, in the state where the discharge lamps FL1 and FL2 are lit, when a connection failure such as disconnection or contact failure occurs in the connection portion (7), the current flowing through the discharge lamps FL1 and FL2 changes and the pole (3 ), A lamp current flows between the discharge lamps FL1 and FL2 via the capacitor C4, the secondary winding 209, and the pole (4). In this case, since the low-impedance discharge lamp FL2 is not connected in parallel to the series circuit of the resistor R9 and the resistor R10, the capacitor C8 is charged by the voltage determined by the voltage division ratio of the resistors R8, R9, R10, and the charging voltage V _C8 Is compared with the reference voltage VrefE in the comparator 203, the charging voltage V _C8 exceeds the reference voltage VrefE, and the output signal VEL of the comparator 203 is output to the inverter control circuit 204 at a high level. Then, the inverter control circuit 204 stops the power supply to the discharge lamps FL1 and FL2, and the discharge lamps FL1 and FL2 are turned off.

Next, in the state where the discharge lamps FL1 and FL2 are turned on, when a connection failure such as disconnection or contact failure occurs in the connection portion (4), the series circuit of the resistors R7 and R10 and the discharge lamp FL2 are connected in parallel. Since the resistor R10 is not connected, the capacitor C8 is charged by the voltage determined by the voltage dividing ratio of the resistors R6, R7, and R10, the charge voltage V _C8 rises, and is compared with the reference voltage VrefE by the comparator 203. _C8 exceeds the reference voltage VrefE, and the output signal VEL of the comparator 203 is output to the inverter control circuit 204 at a high level. Then, the inverter control circuit 204 stops the power supply to the discharge lamps FL1 and FL2, and the discharge lamps FL1 and FL2 are turned off.

As described above, in the series circuit of the filament F2 and the filament F3 connected in series, the pole (3) which is the pole on the high voltage side, the pole (4) which is the pole on the low voltage side, the filament F2 and the filament F3 Is detected, and the discharge lamps FL1 and FL2 are turned off (see, for example, Patent Document 1).
JP 11-354286 A

By the way, in the above-described discharge lamp lighting device, when the user attaches the discharge lamps FL1 and FL2 to the discharge lamp lighting device when the power is turned on or when the discharge lamp is detached from the discharge lamp lighting device, the pole (3 ), The pole (4), and the connecting portion (7) are not connected, but if the poles (1) and (2) are connected, the DC voltage Vdc is applied to the resistor R11, the filament. F1 is applied to the capacitor C10 through the resistors R12 and R13 and the diode D4, and the charging voltage V _C10 of the capacitor C10 rises in the same manner as normal, and the charging voltage V _C10 exceeds the reference voltage VrefN. (3) Connection failure in the pole (4) and the connection part (7) cannot be detected. As a result, the output signal VNL of the comparator 202 is output to the inverter control circuit 204 at a high level. As a result, the inverter control circuit 204 starts the on / off operation of the transistors Q1 and Q2, and starts supplying power to the discharge lamps FL1 and FL2. Since a high voltage is generated to turn on the discharge lamps FL1 and FL2, there is a disadvantage that the voltage stress on each part of the circuit such as the transistors Q1 and Q2 is increased.

  In addition, while the user is installing the discharge lamps FL1 and FL2, the poles (1) and (2) are connected, and the connection of the pole (3), the pole (4), and the connection portion (7) has not yet been completed. In this state, the discharge lamp lighting device tries to start lighting of the discharge lamps FL1 and FL2, which causes inconvenience to the user.

  The present invention has been made in view of such a problem, and provides a discharge lamp lighting device capable of detecting a defect in a filament portion connected in series and not starting lighting of the discharge lamp. The purpose is to provide.

  In order to achieve the above-mentioned object, a discharge lamp lighting device according to the first means of the present invention is a series of discharge lamps by connecting a plurality of discharge lamps having lighting filaments at both ends in series. A plurality of discharge lamps configured to emit light by supplying a lighting voltage to a series circuit of the discharge lamps based on power received from the reception unit configured to receive power from the outside configured as a circuit; A discharge lamp lighting device comprising: a power supply unit; and an abnormality detection unit that detects a failure of the filament unit connected in series, wherein the abnormality detection unit supplies power from the outside by the reception unit The no-load detection unit for detecting a defect of the filament unit connected in series when the acceptance of the lighting is started, and the lighting voltage is supplied by the power supply unit A filament defect detection unit for detecting a defect of the filament unit connected in series when the voltage is on, and the no-load detection unit is connected to the high potential side pole in the filament series circuit. , A first capacitor charged by a current derived from a low potential side pole in the filament series circuit, and a charging voltage of the first capacitor set in advance Power supply from the power supply unit to the series circuit of the discharge lamp when the reference voltage exceeds the reference voltage, and the power supply when the charging voltage of the first capacitor is equal to or lower than the first reference voltage. A first control unit that stops power supply by the unit, the filament defect detection unit, a detection voltage source that outputs a detection voltage for detecting the defect, A series circuit composed of second, third, and fourth resistors for dividing the detection voltage, a second capacitor connected in parallel with the fourth resistor, and a connection between the third and fourth resistors A fifth resistor connecting the point and the low potential side pole, and the connection point between the second and third resistors and the high potential side pole are connected, and the third and A second control unit that stops power supply by the power supply unit when a voltage generated at a connection point between the fourth resistors exceeds a preset second reference voltage; The detection voltage source starts output of the detection voltage after power supply by the power supply unit is started.

  In the above-described discharge lamp lighting device, the power supply unit includes a DC voltage source that outputs a DC voltage, a first switching element to which a DC voltage output from the DC voltage source is applied, and a second switching element. And a rectangular wave voltage output from a connection point between the first and second switching elements by alternately turning on and off the first and second switching elements. Supplying as a lighting voltage to a series circuit of electric lamps, the detection voltage source outputs the rectangular wave voltage as the detection voltage.

  The discharge lamp lighting device includes a series circuit including a third capacitor, a first transformer, and a third switching element, which are connected in parallel with the second switching element. A secondary winding of the transformer is connected to the high-potential side pole and the low-potential side pole via a fourth capacitor, and the third switching element is turned on before the discharge lamp starts to emit light. And a preheating control unit for outputting a preheating current from the secondary winding of the transformer to the series circuit of the filaments and for turning off the third switching element after starting the light emission of the discharge lamp. It is said.

  Further, in the above-described discharge lamp lighting device, the detection voltage source outputs a voltage between the third capacitor and the first transformer as the detection voltage.

  Further, in the above-described discharge lamp lighting device, the power supply unit includes a DC voltage source that outputs a DC voltage between the positive terminal and the negative terminal, a first switching element connected between the positive terminal and the negative terminal, A rectangular circuit voltage output from a connection point between the first and second switching elements by alternately turning on and off the first and second switching elements. , And supplied as a lighting voltage to the series circuit of the discharge lamp via a fifth capacitor and a second transformer, and the first secondary winding of the second transformer is a sixth voltage The detection voltage source is connected to the high-potential side pole and the low-potential side pole via a capacitor, and the detection voltage source outputs the voltage output from the second secondary winding in the second transformer. As voltage It is characterized in that the force.

In the above-described discharge lamp lighting device, the power supply unit includes a DC voltage source that outputs a DC voltage between the positive terminal and the negative terminal, a first switching element connected between the positive terminal and the negative terminal, and a first switching element. A rectangular circuit voltage output from a connection point between the first and second switching elements by alternately turning on and off the first and second switching elements. , And supplied as electric power to the series circuit of the discharge lamp via a fifth capacitor and a second transformer, and the first secondary winding of the second transformer is connected via the sixth capacitor. Connected to the high potential side pole and the low potential side pole,
Instead of providing the fifth resistor, the voltage output from the third secondary winding in the second transformer is rectified, and the first capacitor is charged with this voltage.

  Furthermore, in the above-described discharge lamp lighting device, the second control unit in the filament defect detection unit may receive the second reference voltage within a preset period after the supply of power is received by the reception unit. The power supply is not stopped even when the value exceeds.

  In order to achieve the above-mentioned object, a lighting fixture according to the second means of the present invention is a lighting fixture including a discharge lamp and a discharge lamp lighting device for lighting the discharge lamp, wherein the discharge lamp lighting device is the above-mentioned It is a discharge lamp lighting device.

  When there is a defect in the filament portion connected in series, the discharge lamp lighting device having such a configuration and the lighting fixture using the same are connected to the first resistor via the series circuit of the filament from the first resistor. The first capacitor is prevented from being charged from the current path to the capacitor, and the output of the detection voltage by the detection voltage source is started after the power supply by the power supply unit is started. The first capacitor is charged from the detection voltage source through the second, third, and fifth resistors and the low potential side pole in the series circuit of the filament before the power supply by the unit is started. There is no. Accordingly, since the charging voltage of the first capacitor is made lower than the first reference voltage, the power supply by the power supply unit is stopped and the lighting of the discharge lamp is not started. Thereby, the defect of the filament part connected in series can be detected, and it can be made not to start lighting of a discharge lamp.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

  FIG. 1 is a perspective view showing an example of the appearance of a lighting fixture according to the first embodiment of the present invention. The luminaire 1 shown in FIG. 1 includes a luminaire main body 2 and connectors 4 a, 4 b, 4 c, and 4 d that are erected on the luminaire main body 2 and attach the discharge lamps FL 1 and FL 2 to the luminaire 1. A discharge lamp lighting device 5 is stored inside the luminaire body 2.

  FIG. 2 is a circuit diagram showing an example of the configuration of the discharge lamp lighting device 5 shown in FIG. The discharge lamp lighting device 5 shown in FIG. 2 generates a DC voltage Vdc from a power supply connector 101 that receives an input of the commercial power supply Vac, and the commercial power supply Vac supplied through the power supply connector 101, and passes through the DC power supply line L. The power supply 102 supplied to each part of the discharge lamp lighting device 5, the series circuit composed of the switching elements of the transistors Q1 and Q2 interposed between the DC power supply line L and the ground, and the transistors Q1 and Q2 are alternately turned on. The control circuit unit 103 that generates a high-frequency rectangular wave voltage at the connection point of the transistors Q1 and Q2 by turning them off to function as an inverter and supplies light for light emission to the discharge lamps FL1 and FL2, and starts the inverter operation That is, after the power supply for causing the discharge lamps FL1 and FL2 to emit light is started, And a DC voltage source 115 to start output of the E.

  The connection point between the transistors Q1 and Q2 is connected to one pole (1) of the filament F1 of the discharge lamp FL1 through a parallel circuit of a DC component cutting capacitor C1 and a resistor R5 and a resonance transformer T1. ing. The discharge lamps FL1 and FL2 are connected in series to form a discharge lamp series circuit, and the discharge lamp series circuit and the resonance capacitor C2 are connected in parallel. Furthermore, a resonant load circuit is configured by the transformer T1, the capacitor C2, and the discharge lamps FL1 and FL2.

  The control circuit unit 103 responds to the control signal from the inverter control circuit 106 and the inverter control circuit 106 that outputs a control signal to alternately turn on and off the comparators 104 and 105, and the transistors Q1 and Q2 in a predetermined cycle. And a drive circuit 107 for turning on and off the transistors Q1 and Q2. The inverter control circuit 106 is configured by using, for example, a CPU (Central Processing Unit) and a timer circuit, and is a control unit for controlling the frequency for turning on and off the transistors Q1 and Q2 to operate as an inverter. When the output signal VNL of 104 is at a high level and the output signal VEL of the comparator 105 is at a low level, the inverter operation is started by alternately turning on and off the transistors Q1 and Q2, and power is supplied to the discharge lamps FL1 and FL2. On the other hand, when the signal VNL is at a low level or the signal VEL is at a high level, the transistors Q1 and Q2 are turned off to stop the power supply to the discharge lamps FL1 and FL2. Further, the control circuit unit 103 has a mask period in which the power supply to the discharge lamps FL1 and FL2 is not stopped even when the output signal VEL of the comparator 105 becomes high level for a certain time after the power is turned on. ing.

  The filament F2 on the opposite side of the filament F1 in the discharge lamp FL1 and the filament F3 of the discharge lamp FL2 are connected in series at the connecting portion (7) to form a discharge lamp series circuit by the discharge lamps FL1 and FL2. The discharge lamp series circuit and the resonance capacitor C2 are connected in parallel. That is, the filaments F2 and F3, the connecting portion (7), the high potential side pole (3) of the filament F2, and the low potential side pole (4) of the filament F3 are in the “filament portion connected in series”. Equivalent to.

  A connection point between the capacitor C1 and the resonance transformer T1 is connected to the ground via resistors R1 and R2, and a capacitor C7 is connected in parallel with the resistor R2. Further, the connection point between the capacitor C7 and the resistor R1 is connected to the non-inverting input terminal of the comparator 105 via the diode D1. The resistors R1 and R2 and the capacitor C7 constitute a DC detection circuit 114 that detects a direct current component of the load.

  The pole (2) opposite to the pole (1) in the filament F1 is connected to the DC power supply line L via the resistor R11. The pole (2) is connected to the ground through a series circuit of a resistor R3 and a parallel circuit of a resistor R4 and a capacitor C9, and the connection point of the resistor R3 and the resistor R4 is connected to the non-contact of the comparator 105 via the diode D3. It is connected to the inverting input terminal. The resistors R3 and R4 and the capacitor C7 constitute a DC detection circuit 116 that detects a DC component of the load.

  The DC voltage source 115 is connected to the ground via resistors R8, R9, R10, a capacitor C8 is connected in parallel with the resistor R10, and the connection point of the resistors R9, R10 is connected to the non-contact of the comparator 105 via the diode D2. It is connected to the inverting input terminal. A series circuit of a resistor R6 and a capacitor C4 is connected in parallel to the resistor R8. And the connection point of resistance R8, R9 and the capacitor | condenser C4 is connected with the pole (3) on the opposite side to the connection part (7) in the filament F2. Moreover, the pole (4) on the opposite side to the connection part (7) in the filament F3 is connected to the connection point of the resistors R9 and R10 via the resistor R7. The resistors R6, R7, R8, R9, R10, the capacitor C8, and the comparator 105 constitute a filament defect detection circuit 108. The filament defect detection circuit 108 is activated when any one of the pole (3), the pole (4), and the connecting portion (7) is in a faulty state such as disconnection or contact failure after the discharge lamps FL1 and FL2 are turned on. This is a circuit for turning off the lights FL1 and FL2.

  The pole (1) is connected to the pole (3) via the resistor R12. The pole (4) is connected to the ground via a resistor R13 and a reversely connected Zener diode ZD1, and a series circuit of a diode D4 and a resistor R14 is connected in parallel with the Zener diode ZD1, and in parallel with the resistor R14. The capacitor C10 is connected, and the connection point between the diode D4 and the capacitor C10 is connected to the non-inverting input terminal of the comparator 104. The resistors R11, R12, R13, R14, the diode D4, the Zener diode ZD1, the capacitor C10, and the comparator 104 constitute a no-load detection circuit 109. The no-load detection circuit 109 detects the connection failure of the poles (1), (2), (3), (4), the disconnection of the filaments F1, F2, F3, etc. when the power is turned on, and discharge lamps FL1, FL2 Is a circuit for turning off (not turning on).

  The DC power supply line L is connected to the ground via resistors R15, R16, and R17, and the connection point of the resistors R15 and R16 is the pole (5) in the filament F4 on the opposite side of the filament F3 of the discharge lamp FL2. Connected with. The capacitor C11 is connected in parallel with the resistor R17, the connection point between the resistor R17 and the capacitor C11 is connected to the base of the transistor Q3, the emitter of the transistor Q3 is connected to the ground, and the emitter of the transistor Q3 is connected via the resistor R18. It is connected to a connection point between the resistor R13 and the anode of the diode D4. The no-load detection circuit 113 is configured by the resistors R15, R16, R17, R18, C11, and the transistor Q3. The no-load detection circuit 113 is a circuit for turning off the discharge lamps FL1 and FL2 when any of the pole (5), the pole (6), and the filament F4 is in a defective state such as disconnection or contact failure. is there.

  The transformer T1 includes secondary windings 110, 111, and 112. One end of the secondary winding 110 is connected to the pole (1) via the capacitor C3, and the other end is connected to the pole (2). One end of the secondary winding 111 is connected to the pole (3) via the capacitor C4, and the other end is connected to the pole (4). One end of the secondary winding 112 is connected to the pole (5) in the filament F4, and the other end is connected to the pole (6) opposite to the pole (5) via the capacitor C5.

  The pole (1) and the pole (2) are connected between the discharge lamp lighting device 5 and the discharge lamp FL1, for example, by a connector 4a, and the pole (3) is connected to the discharge lamp lighting device 5, for example, by a connector 4b. The pole (4) is connected between the discharge lamp lighting device 5 and the discharge lamp FL2, for example, by the connector 4c, and the pole (5) and the pole (6) are, for example, by the connector 4d. The discharge lamp lighting device 5 and the discharge lamp FL2 are connected, and the connecting portion (7) is connected between the discharge lamp FL1 and the discharge lamp FL2 by the connector 4b and the connector 4c. The connectors 4a, 4b, 4c, and 4d are configured such that the user can attach and detach the discharge lamps FL1 and FL2.

  Next, the lighting operation of the discharge lamp lighting device 5 configured as described above will be described. 3 and 4 are diagrams for explaining the operation of the discharge lamp lighting device 5. First, the operation of the discharge lamps FL1 and FL2 when the filament state and the connection of the pole (1) to the pole (6), the connection portion (7), etc. are normal will be described. First, when power is turned on by the user, the commercial power supply Vac is received by the power connector 101, and the DC voltage Vdc is supplied to each part of the discharge lamp lighting device 5 by the power supply unit 102 via the DC power supply line L.

  When the DC voltage Vdc is supplied, the inverter control circuit 106 alternately turns on and off the transistors Q1 and Q2 at a frequency fph higher than the no-load resonance frequency fo determined by the inductance of the transformer T1 and the capacitance of the capacitor C2. Start the inverter oscillation. As a result, a low resonance voltage that does not start lighting is applied to the series circuit of the discharge lamps FL1 and FL2. At this time, the preheating current for heating the filament F1, the filaments F2, F3, and the filament F4 flows from the secondary windings 110, 111, and 112 of the transformer T1 through C3, C4, and C5, respectively (preceding preheating mode). ).

  The inverter control circuit 106 changes the operating frequency of the inverter from the frequency fph to the frequency fst so that the discharge lamps FL1 and FL2 are turned on after a preset preheating time has elapsed. The applied resonance voltage rises and the discharge lamps FL1 and FL2 are turned on (starting mode).

  Thereafter, the on / off frequency of the inverter by the inverter control circuit 106 is changed to a frequency ft of a lower frequency and shifts to a normal lighting state, and the discharge lamps FL1 and FL2 are caused to emit light stably. The discharge lamps FL1 and FL2 are turned on by the above sequence operation.

  By the way, if the filaments of the discharge lamps FL1 and FL2 are disconnected, or the connection of the pole (1) to the pole (6), the connection portion (7) is disconnected or is poorly connected, the discharge lamp is assumed to be as it is. When FL1 and FL2 are turned on, the non-resonant resonance characteristics shown in FIG. 4 are approached, so that the voltage applied to the discharge lamps FL1 and FL2 rises, and the voltage stress in each circuit section in the discharge lamp lighting device 5 is increased. There is an inconvenience that an increase in arc or an arc occurs in a defective part.

  Therefore, the discharge lamp lighting device 5 shown in FIG. 2 includes the filament defect detection circuit 108, the no-load detection circuit 109, the no-load detection circuit 113, the DC detection circuit 114, and the DC detection circuit 116, so that the discharge lamps FL1 and FL2 are provided. The voltage stress is reduced by detecting the disconnection of the filament and the connection failure of the pole (1) to the pole (6), the connection portion (7), etc., and preventing the discharge lamps FL1 and FL2 from being turned on at the time of failure. I am doing so.

  Next, operations of the filament defect detection circuit 108, the no-load detection circuit 109, the no-load detection circuit 113, the DC detection circuit 114, and the DC detection circuit 116 will be described. First, the operation of the discharge lamps FL1 and FL2 when the filament state and the connection of the pole (1) to the pole (6), the connection portion (7), etc. are normal will be described.

  First, when power is turned on by the user, the commercial power supply Vac is received by the power connector 101, and the DC voltage Vdc is supplied to each part of the discharge lamp lighting device 5 by the power supply unit 102 via the DC power supply line L.

  When the DC voltage Vdc is supplied, the inverter control circuit 106 applies a DC bias voltage from the DC voltage Vdc to the base of the resistor R17, the capacitor C11, and the transistor Q3 via R15 and R16 in the no-load detection circuit 113. Is done. At the same time, a bias voltage is applied to the filament F4 through the path of R15, the pole (5), the filament F4, and the pole (6). However, the filament resistance value is approximately several Ω to several tens Ω, and the resistors R15, R16, and R17 are configured with relatively large resistance values (approximately several tens kΩ to several MΩ) that do not affect the resonant load circuit. Yes. Therefore, since the voltage generated between the poles (5) and (6) is very small, the voltage applied to the resistor R16 and the resistor R17 connected in parallel is very low, and almost no current is supplied to the base of the transistor Q3. No. Therefore, the transistor Q3 is turned off.

In the no-load detection circuit 109, the capacitor C10 and the resistor R14 are charged from the DC voltage Vdc through the resistors R11, R12, R13, and the diode D4, and the charging voltage V _C10 exceeds the reference voltage VrefN. Then, the output signal signal VNL of the comparator 104 becomes high level. As a result, the inverter control circuit 106 turns on and off the transistors Q1 and Q2 to start the inverter operation, outputs a high-frequency rectangular wave voltage, and supplies power to the discharge lamps FL1 and FL2.

When power supply to the discharge lamps FL1 and FL2 is started, a high-frequency voltage is generated at both ends of the discharge lamps FL1 and FL2, and the high-frequency voltage is half-wave rectified in the Zener diode ZD1, and a peak portion is formed by the Zener diode ZD1. A clamped voltage waveform is generated. This voltage waveform is filtered by the diode D4, the capacitor C10, and the resistor R14, and the voltage of the charging voltage V _C10 is maintained at a level exceeding the reference voltage VrefN even after the inverter is operated.

In the DC detection circuit 114, the capacitor C7 is charged to a predetermined voltage value from the DC voltage Vdc through the resistor R11, the filament F1, the transformer T1, and the resistor R1, and is output to the comparator 105 as the charging voltage V _C8 . The charging voltage V _C8 may exceed the reference voltage VrefE due to the resistance voltage of the transient voltage at the start of power supply to the discharge lamps FL1 and FL2. In this case, since the inverter control circuit 106 has a mask period, the voltage of the charging voltage V _C8 output from the DC detection circuit 114 exceeds the reference voltage VrefE, and the signal VEL is output from the comparator 105 at a high level. Even in this case, the inverter control circuit 106 does not stop the power supply to the discharge lamps FL1 and FL2. For this purpose, the mask period is determined according to the transient response time at the start of power supply.

  Next, when electric power is supplied to the discharge lamps FL1 and FL2 and the discharge lamps FL1 and FL2 are turned on, the impedance of the discharge lamps FL1 and FL2 decreases. The impedance at the time of lighting varies depending on the ratings of the discharge lamps FL1 and FL2, but is generally several hundred Ω to several kΩ. The resistors R1 and R2 constituting the DC detection circuit 114 are constituted by several tens kΩ to several hundreds kΩ so as not to affect the resonance load circuit. Therefore, when the discharge lamps FL1 and FL2 are lit, almost no voltage is generated in the resistor R2 and the capacitor C7 under the condition that no DC voltage is generated in the discharge lamps FL1 and FL2, so that the lighting state of the lamps FL1 and FL2 is maintained. Is done.

In the DC detection circuit 116, the capacitor C9 is charged from the direct-current voltage Vdc through the resistors R11 and R3 to a predetermined voltage value. As in the case of the DC detection circuit 114, this charging potential value may exceed the reference voltage VrefE due to a transient voltage at the start of power supply to the discharge lamps FL1 and FL2. However, since the inverter control circuit 106 has a mask period, the charging voltage V _C8 output from the DC detection circuit 114 exceeds the reference voltage VrefE, and the signal VEL is output from the comparator 105 at a high level. Even in this case, the inverter control circuit 106 does not stop the power supply to the discharge lamps FL1 and FL2.

  Next, when electric power is supplied to the discharge lamps FL1 and FL2 and the discharge lamps FL1 and FL2 are turned on, the impedance of the discharge lamps FL1 and FL2 decreases. In the DC detection circuit 116 as well, like the DC detection circuit 114, the resistors R3 and R4 constituting the DC detection circuit 116 are configured with several tens kΩ to several hundreds kΩ so as not to affect the resonance load circuit. Therefore, when the discharge lamps FL1 and FL2 are turned on, no voltage is generated in the resistor R4 and the capacitor C9 under the condition that no DC voltage is applied to the discharge lamps FL1 and FL2, so that the lighting state of the lamps FL1 and FL2 is maintained. .

In the filament defect detection circuit 108, the DC voltage source 115 charges the capacitor C8 to a predetermined voltage value via the resistors R6 and R7 and the resistors R8 and R9. In this case, the DC voltage source 115 generates almost no output voltage before the start of the inverter operation and outputs the DC voltage E after the start of the inverter operation. Therefore, the capacitor C8 is charged before the start of the inverter operation. There is nothing. In the mask period after the power is turned on, the charging voltage V _C8 output from the filament defect detection circuit 108 exceeds the reference voltage VrefE, and the signal VEL is output from the comparator 105 at a high level. However, the inverter control circuit 106 does not stop the power supply to the discharge lamps FL1 and FL2.

  Next, when electric power is supplied to the discharge lamps FL1 and FL2 and the discharge lamps FL1 and FL2 are turned on, the impedance of the discharge lamps FL1 and FL2 decreases. The resistors R6, R7, R8, R9, and R10 that constitute the filament defect detection circuit 108 are configured with several tens of kΩ to several hundreds of kΩ so that the resonance load circuit is not affected. Therefore, when the discharge lamps FL1 and FL2 are turned on, the voltage dividing ratio of the resistors R7, R9 and R10 is remarkably reduced, and almost no voltage is generated in the capacitor C8, so that the lighting state of the lamps FL1 and FL2 is maintained.

  Next, the operation when the filament F1 is disconnected or the connection between the pole (1) and the pole (2) is poor when the power is turned on will be described.

In this case, in the no-load detection circuit 109, the DC bias path for supplying the DC voltage Vdc from the power supply unit 102 to the capacitor C10 is interrupted, so that the capacitor C10 is not charged, and therefore the charging voltage V _C10 is equal to or lower than VrefN. . Then, the signal VNL is output at a low level from the comparator 104, the on / off operation of the transistors Q1, Q2 by the inverter control circuit 106 is not started, and the discharge lamps FL1, FL2 are not lit.

  Next, the operation when the filament F4 is disconnected or the connection between the pole (5) and the pole (6) is poor when the power is turned on will be described.

In this case, in the no-load detection circuit 113, since the resistance values at the pole (5), the filament F4, and the pole (6) connected in parallel with the resistors R16 and R17 increase, the DC voltage output from the power supply unit 102 is increased. Vdc sufficiently supplies the base current to the transistor Q3 via the resistors R15 and R16, and Q3 is turned on. Then, since the resistor R18 is set to a resistance value that significantly reduces the voltage dividing ratio of the resistor R14 connected in parallel with the series circuit of the transistor Q3 and the resistor R18, the charging voltage V _C10 of the capacitor C10 is set to the reference voltage VrefN. It becomes as follows. Then, the signal VNL is output at a low level from the comparator 104, the on / off operation of the transistors Q1, Q2 by the inverter control circuit 106 is not started, and the discharge lamps FL1, FL2 are not lit.

  Next, the operation in the case where the filaments F2 and F3 are disconnected or the pole (3), the pole (4), and the connection portion (7) are poorly connected when the power is turned on will be described.

In this case, in the no-load detection circuit 109, the DC bias path for supplying the DC voltage Vdc from the power supply unit 102 to the capacitor C10 is interrupted, so that the capacitor C10 is not charged, and therefore the charging voltage V _C10 becomes VrefN or less. Then, the signal VNL is output at a low level from the comparator 104, the on / off operation of the transistors Q1, Q2 by the inverter control circuit 106 is not started, and the discharge lamps FL1, FL2 are not lit.

In this case, in the filament defect detection circuit 108, the capacitor C8 is charged to a predetermined voltage value via the resistors R6 and R7 and the resistors R8 and R9 by the DC voltage Vdc from the power supply unit 102 instead of the DC voltage source 115. In the case of the configuration, in the no-load detection circuit 109, the path from the power supply unit 102 through the resistors R8, R9, R7, R13, and the diode D4, the secondary winding 111, the resistor R13, Capacitor C10 is charged through the path via diode D4, charging voltage V _C10 exceeds VrefN, signal VNL is output at high level from comparator 104, and ON / OFF operation of transistors Q1 and Q2 by inverter control circuit 106 starts. As a result of starting the lighting operation of the discharge lamps FL1, FL2, the non-negative resonance shown in FIG. In order to approach the characteristics, it is conceivable that the voltage applied to the discharge lamps FL1 and FL2 increases, and the voltage stress in each circuit section in the discharge lamp lighting device 5 increases.

  However, in the filament defect detection circuit 108, before starting the inverter operation, the capacitor C8 is connected via the resistors R6 and R7 and the resistors R8 and R9 by the DC voltage E from the DC voltage source 115 that hardly generates an output voltage. It is configured to be charged up to a predetermined voltage value. Therefore, the capacitor C10 is charged from the path from the DC voltage source 115 through the resistors R8, R9, R7, R13, and the diode D4, and from the path from the resistor R6 through the secondary winding 111, the resistor R13, and the diode D4. The discharge lamps FL1 and FL2 are not lit.

  As described above, when the power is turned on, the connection points in the discharge lamps FL1, FL2 including the filaments F2, F3 connected in series, the pole (3), the pole (4), and the connection part (7) are defective. , And filament breakage can be detected at all locations so that lighting of the discharge lamps FL1, FL2 is not started.

  Next, an operation when the pole (1) becomes defective in connection during normal lighting (after the mask period has elapsed) will be described.

In this case, the lamp current flowing through the resonant load circuit is from the transformer T1 to the capacitor C3, the secondary winding 110, the pole (2), the filament F1, the discharge lamp FL1, the filament F2, the connection part (7), the filament F3, the discharge lamp. It flows along the path to the ground via FL2, the filament F4, and the pole (6). In this case, since a high-frequency voltage is continuously generated at the connection portion between R12 and the capacitor C2 in the no-load detection circuit 109, the capacitor C10 maintains the potential at the time of normal lighting. Accordingly, since the charging voltage V _C10 exceeds the reference voltage VrefN and the output signal signal VNL of the comparator 104 is at a high level, the connection failure of the pole (1) is not detected by the no-load detection circuit 109.

On the other hand, in the DC detection circuit 114, in this case, the DC detection circuit 114 and the no-load detection circuit 109 are configured in parallel with the series circuit component of the capacitor C3 and the discharge lamps FL1 and FL2 (R11). Is excluded). If this combined impedance is Z1, the capacitor C1 and the capacitor C3 share the voltage obtained by dividing the DC component voltage of the capacitor C1 by the resistor R5 and the impedance Z1, respectively. As a result, a direct current component voltage is generated in the series component portion of the capacitor C3 and the discharge lamps FL1 and FL2, and thus a direct current component voltage is also generated in the DC detection circuit 114. Accordingly, the charging voltage V _C8 of the capacitor C7 exceeds the reference voltage VrefE, the inverter operation is stopped by the comparator 105 and the inverter control circuit 106, the power supply to the discharge lamps FL1, FL2 is stopped, and the discharge lamps FL1, FL2 Turns off.

  Next, the operation when the pole (2) becomes poorly connected during normal lighting (after the mask period) will be described.

The lamp current path that flows through the resonant load circuit when the pole (2) is poorly connected is the same as the lamp current path (transformer T1, pole (1), discharge lamps FL1, FL2) during normal operation, but is normal. , The discharge lamps FL1 and FL2 connected in parallel with the resistors R3 and R4 in the DC detection circuit 116 are separated by the pole (2), and are discharged from the connection point of the resistors R11 and R3 through the secondary winding 110. Since the current path to the electric lamps FL1 and FL2 is DC-isolated by the capacitor C3, the voltage dividing ratio of the resistors R11, R3 and R4 is not affected by the impedance of the discharge lamps FL1 and FL2. Accordingly, the capacitor C9 is charged by the voltage determined by the voltage dividing ratio of the resistors R11, R3, and R4, and the charging voltage V _C8 of the capacitor C9 exceeds the reference voltage VrefE. Therefore, the inverter operation is oscillated by the comparator 105 and the inverter control circuit 106. The power supply to the discharge lamps FL1 and FL2 is stopped, and the discharge lamps FL1 and FL2 are turned off.

  Next, when the filament F1 is disconnected during normal lighting (after the mask period), a detection function similar to that in the above-described connection failure mode of the pole (1) or the connection failure mode of the pole (2) works, and the inverter Control circuit 106 stops oscillation of the inverter operation, power supply to discharge lamps FL1 and FL2 is stopped, and discharge lamps FL1 and FL2 are turned off.

  Next, when the filament F4 is disconnected during normal lighting (after the mask period), or when the pole (5) or pole (6) is poorly connected, the filament F4 is disconnected or the pole (5) or pole when the power is turned on. In the same manner as in the case of connection failure (6), the disconnection or connection failure is detected by the no-load detection circuit 113, the inverter operation is stopped, and the discharge lamps FL1 and FL2 are turned off.

Next, the operation when the pole (3) or the pole (7) is poorly connected during normal lighting (after the mask period) will be described. When the pole (3) is poorly connected, the path of the lamp current flowing through the discharge lamps FL1 and FL2 does not change and flows through the connection (7). Then, in the filament defect detection circuit 108, in the current path from the DC voltage source 115 through the resistor R6, the secondary winding 111, and the resistor R7 to the parallel circuit of the resistor R10 and the capacitor C8, the resistors R7 and R10 Since the discharge lamp FL2 exists in parallel with the series configuration, the charging voltage of the capacitor C8 hardly occurs. On the other hand, in the current path from the DC voltage source 115 via the resistors R8 and R9 to the parallel circuit of the resistor R10 and the capacitor C8, the discharge lamp is not connected in parallel to the series configuration of the resistors R9 and R10 (capacitor C4 Thus, the series circuit of the resistors R9 and R10 is separated from the discharge lamp). Therefore, the capacitor C8 is charged with a DC voltage obtained by dividing the DC voltage E by the resistors R8, R9, and R10. Since the charging voltage V _C8 of the capacitor C8 exceeds the reference voltage VrefE, the comparator 105 and the inverter control circuit 106 Inverter operation is stopped, power is not supplied to the discharge lamps FL1 and FL2, and the discharge lamps FL1 and FL2 are turned off.

On the other hand, when the pole (7) is poorly connected, the lamp current path from the discharge lamp FL1 via the pole (7) to the discharge lamp FL2 is interrupted, so the lamp current path changes and the discharge lamp It becomes a current path that reaches the discharge lamp FL2 via FL1, the pole (3), the capacitor C4, the secondary winding 111, and the pole (4). In this case, since the discharge lamp is not connected in parallel to the series configuration portion of the resistors R9 and R10 in the filament defect detection circuit 108 and there is no connection of a low impedance element, the capacitor C8 applies the DC voltage E to the resistors R8, R9, and R10. Since the charging voltage V _C8 of the capacitor C8 exceeds the reference voltage VrefE, the inverter operation is stopped by the comparator 105 and the inverter control circuit 106, and power to the discharge lamps FL1 and FL2 is charged. Supply is lost and the discharge lamps FL1, FL2 are turned off.

Next, the operation when the pole (4) is poorly connected during normal lighting (after the mask period) will be described. When the pole (4) is poorly connected, the lamp current path in the discharge lamps FL1 and FL2 does not change and flows through the connection (7). In this case, in the filament defect detection circuit 108, since the discharge lamp FL2 exists in parallel with the series configuration of the resistors R9 and R10, the charging voltage of the capacitor C8 hardly occurs. On the other hand, since the discharge lamp is not connected in parallel to the series configuration of the resistors R7 and R10, there is no connection of a low impedance element (the capacitor C4 separates the series circuit of the resistors R7 and R10 from the discharge lamp). The capacitor C8 is charged with a DC voltage obtained by dividing the DC voltage E by the resistors R6, R7, and R10. Since the charging voltage V _C8 of the capacitor C8 exceeds the reference voltage VrefE, the comparator 105 and the inverter control circuit 106 The inverter operation stops oscillating, power supply to the discharge lamps FL1 and FL2 is stopped, and the discharge lamps FL1 and FL2 are turned off.

  Next, when the filament F2 or the filament F3 is disconnected at the time of normal lighting (after the mask period), the connection failure mode of the pole (3) or the pole (7) or the connection failure mode of the pole (4) described above. Similarly, the filament defect detection circuit 108 operates, the inverter operation stops oscillating, and the discharge lamps FL1 and FL2 are turned off.

  As described above, the discharge lamp lighting device 5 and the luminaire 1 using the discharge lamp lighting device 5 shown in FIG. 2 have filaments F2, F3 and poles (3) connected in series, for example, when the power is turned on or when the load is remounted. , Including the failure of the pole (4) and the connection portion (7), the failure of the connection locations of the electrodes (1) to (6) and the connection portion (7) and the breakage of the filaments F1 to F4 in the discharge lamps FL1 and FL2. Detecting at all points, it is possible not to start lighting the discharge lamps FL1 and FL2 when the power is turned on, and to stop the power supply to the discharge lamps FL1 and FL2 when the load is remounted. . In addition, even during normal lighting, it is possible to detect connection failures such as terminals and wiring connected to the discharge lamps FL1 and FL2, and failures such as filament breakage, so these failures can be prevented without reaching the arc generation mode. The discharge lamps FL1 and FL2 can be extinguished.

  This reduces the increase in voltage stress on each part of the circuit, such as the transistors Q1 and Q2, in order to turn on the discharge lamps FL1 and FL2 when the connection location such as the terminal is defective or the filament is disconnected. In addition, while the user is installing the discharge lamps FL1 and FL2, the poles (1) and (2) are connected, and the connection of the pole (3), the pole (4), and the connection portion (7) has not yet been completed. In the state, since the lighting of the discharge lamps FL1 and FL2 is not started, giving anxiety to the user is reduced.

  Compared with the discharge lamp lighting device according to the background art shown in FIG. 11, the discharge lamp lighting device 5 according to the present invention shown in FIG. 2 requires almost no additional parts, thereby suppressing an increase in cost. The problem of the discharge lamp lighting device shown in FIG. 11 can be solved.

Further, the voltage applied transiently to the discharge lamps FL1 and FL2 rises when the power is turned on, and the charging voltage V _C8 output from any one of the filament defect detection circuit 108 and the detection circuits 114 and 116 is Although it is conceivable that the reference voltage VrefE is exceeded, the control circuit unit 103 has a mask period, so that the discharge lamps FL1 and FL2 are not turned on by such a transient voltage rise when the power is turned on. Can be reduced.

  Although the case where two discharge lamps are connected in series has been described as an example, three or more discharge lamps may be connected in series. In this case, a circuit similar to the filament defect detection circuit 108 and the no-load detection circuit 109 may be provided in the connection portion where the discharge lamps are connected in series.

(Second Embodiment)
Next, a discharge lamp lighting device according to a second embodiment of the present invention will be described. FIG. 5 is a circuit diagram showing an example of the configuration of the discharge lamp lighting device according to the second embodiment of the present invention.

  The discharge lamp lighting device 5a shown in FIG. 5 is different from the discharge lamp lighting device 5 shown in FIG. 1 in the following points. That is, in the discharge lamp lighting device 5a shown in FIG. 5, instead of the resistor R5 in the discharge lamp lighting device 5, a series circuit of a resistor R5 and a diode D5 is connected in parallel with the capacitor C1. The connection point of the drain of the transistor Q2, the resistor R5, and the capacitor C1 is connected to the resistors R6 and R8 in the filament defect detection circuit 108. The transistor Q2, the resistor R5, the diode D5, and the capacitor C1 constitute a DC voltage source 115a. That is, the voltage generated at the connection point between the drain of the transistor Q2, the resistor R5, and the capacitor C1 is used as the DC voltage E.

  Since the other configuration is the same as that of the discharge lamp lighting device 5 shown in FIG. 1, the description thereof will be omitted, and the operation of the present embodiment will be described below.

  First, the operation of turning on the discharge lamps FL1 and FL2 in the discharge lamp lighting device 5a and the operation of not detecting or turning off the discharge lamp by detecting a failure such as a connection failure are the same as those of the discharge lamp lighting device 5 shown in FIG. Since it is the same, the description is omitted.

  Next, the operation of the DC voltage source 115a will be described. First, in a state before the inverter operation by the transistors Q1 and Q2 is started by the inverter control circuit 106, the transistors Q1 and Q2 are both off, and equivalently, both hold a minute capacitance component, The voltage across the transistor Q2 is almost 0V. Most of the DC voltage Vdc is applied to the transistor Q1. Therefore, before the inverter operation by the transistors Q1 and Q2 is started, that is, before the power supply for causing the discharge lamps FL1 and FL2 to be emitted is started, the DC voltage E output from the DC voltage source 115a is almost equal to 0V.

  FIG. 6 is a diagram showing a DC equivalent circuit of the discharge lamp lighting device 5a before the inverter operation by the transistors Q1 and Q2 is started. In FIG. 6, the combined impedance for each detection circuit is indicated by a block. The transformer T1 ideally has a DC resistance of 0Ω, and the capacitor C2 is ideally omitted because the DC resistance is ideally infinite. It is assumed that the wiring to each discharge lamp FL1, FL2 is normally connected. In this case, the impedance of the DC detection circuit 114 is connected in parallel to the transistor Q2, and further, the filament defect detection circuit 108, the no-load detection circuit 109, the no-load detection circuit 113, and the DC detection are connected via the resistor R5 and the diode D5. A parallel circuit of the circuit 116 is connected.

  On the other hand, for the transistor Q1, the resistor R11 is disconnected in a DC manner by the diode D5, and the impedance is not connected. Accordingly, almost all of the capacitance sharing ratio between the transistors Q1 and Q2 is distributed to the transistor Q1. Therefore, the drain terminal of the transistor Q2 is approximately 0V.

  Further, during normal operation, a voltage is applied to the capacitor C1 in the direction of the arrow 117 shown in FIG. The resistor R5 is set to several tens kΩ to several hundreds kΩ. For this reason, almost no current flows through the diode D5 during normal operation, no reverse bias is applied, and no transient resonance voltage is applied, so that the diode D5 does not require a diode having a high recovery characteristic. Further, since the filament defect detection circuit 108 does not require a large current to detect a defect, the current capacity of the diode D5 can be reduced, and therefore an inexpensive diode can be used as the diode D5.

  As a result, the DC voltage source 115a functions in the same manner as the DC voltage source 115 shown in FIG. 2. Therefore, the discharge lamp lighting device 5a shown in FIG. 5 and the lighting fixture using the same are the discharge lamp lighting device shown in FIG. 5 can be produced.

(Third embodiment)
Next, a discharge lamp lighting device according to a third embodiment of the present invention will be described. FIG. 7 is a circuit diagram showing an example of the configuration of the discharge lamp lighting device according to the third embodiment of the present invention.

  The discharge lamp lighting device 5b shown in FIG. 7 differs from the discharge lamp lighting device 5a shown in FIG. 5 in the following points. That is, in the discharge lamp lighting device 5b shown in FIG. 7, a preheating cut circuit 118 including a series circuit of a DC component cutting capacitor C6, a preheating transformer T2, and a transistor Q4 is connected in parallel with the transistor Q2. Further, the transformer T1 does not include the secondary windings 110, 111, and 112, and the transformer T2 includes the secondary windings 110, 111, and 112. Inverter control circuit 106a controls on / off of transistor Q4 in addition to transistors Q1 and Q2. Drive circuit 107a turns on / off transistors Q1, Q2, and Q4 in response to a control signal from inverter control circuit 106a.

  Since the other configuration is the same as that of the discharge lamp lighting device 5a shown in FIG. 5, the description thereof will be omitted, and the operation of the present embodiment will be described below.

  First, the operation of turning on the discharge lamps FL1 and FL2 in the discharge lamp lighting device 5b and the operation of not turning on or turning off the discharge lamp by detecting a defect such as a connection failure are the same as those of the discharge lamp lighting device 5a shown in FIG. Since it is the same, the description is omitted.

  The discharge lamp lighting device 5b shown in FIG. 7 differs in preheating operation of the filaments F1, F2, F3, and F4. First, the inverter control circuit 106a turns on the transistor Q4 during the period from when the power is turned on to when the preceding preheating starts and during the preceding preheating mode. As a result, a current flows through the preheating cut circuit 118 to heat the filament F1, the filaments F2, F3, and the filament F4 from the secondary windings 110, 111, and 112 of the transformer T2 via C3, C4, and C5, respectively. A pre-heating current flows and the filaments F1, F2, F3, F4 are pre-heated.

  In the start mode and in the normal lighting state, the inverter control circuit 106a turns off the transistor Q4 so that no current flows through the preheating cut circuit 118, and the constant preheating current of the filaments F1, F2, F3, and F4 is cut. The Thereby, the power loss in the discharge lamp lighting device 5b can be reduced.

(Fourth embodiment)
Next, a discharge lamp lighting device according to a fourth embodiment of the present invention will be described. FIG. 8 is a circuit diagram showing an example of the configuration of a discharge lamp lighting device according to the fourth embodiment of the present invention.

  The discharge lamp lighting device 5c shown in FIG. 8 is different from the discharge lamp lighting device 5b shown in FIG. 7 in the following points. That is, in the discharge lamp lighting device 5c shown in FIG. 8, instead of the connection point between the drain of the transistor Q2, the resistor R5, and the capacitor C1, the connection point between the capacitor C6 and the transformer T2 is It is connected to resistors R6 and R8. The transistor Q2 and the preheating cut circuit 118 function as the DC voltage source 115b, and the voltage generated at the connection point between the capacitor C6 and the transformer T2 is used as the DC voltage E. Further, the discharge lamp lighting device 5c does not include the diode D5.

  Since the other configuration is the same as that of the discharge lamp lighting device 5b shown in FIG. 7, the description thereof will be omitted, and the operation of the present embodiment will be described below.

  First, the operation of turning on the discharge lamps FL1 and FL2 in the discharge lamp lighting device 5c, the operation of not detecting or turning off the discharge lamp by detecting a failure such as a connection failure, and the preheating operation of the filament are shown in FIG. Since it is the same as that of the discharge lamp lighting device 5b, the description thereof is omitted.

  Next, the operation of the DC voltage source 115b will be described. First, when the power is turned on, since the transistor Q4 is turned on by the inverter control circuit 106a, the DC voltage E is set to the ground potential via the transistor Q4 and the transformer T2, and becomes approximately 0V. Further, during normal operation, the transistor Q4 is turned off by the inverter control circuit 106a, so that the voltage across the transistor Q2 is applied as the DC voltage E (pulse voltage with the DC voltage Vdc as a peak). Therefore, the DC voltage source 115b starts output of the DC voltage E after the inverter control circuit 106a starts the inverter operation of the transistors Q1 and Q2 and starts supplying power for lighting the discharge lamps FL1 and FL2.

  As a result, the DC voltage source 115b functions in the same manner as the DC voltage source 115a shown in FIG. 7. Therefore, the discharge lamp lighting device 5c shown in FIG. 8 and the lighting fixture using the same are the discharge lamp lighting device shown in FIG. 5 can be produced. Further, the diode D5 can be eliminated as compared with the discharge lamp lighting device 5 shown in FIG. 7, and the circuit can be simplified and the cost can be reduced. The DC voltage source 115b can obtain the same effect even when it is configured to supply the voltage generated at the connection point between the transformer T2 and the transistor Q4 as the DC voltage E.

(Fifth embodiment)
Next, a discharge lamp lighting device according to a fifth embodiment of the present invention will be described. FIG. 9 is a circuit diagram showing an example of the configuration of a discharge lamp lighting device according to the fifth embodiment of the present invention.

  The discharge lamp lighting device 5d shown in FIG. 9 is different from the discharge lamp lighting device 5 shown in FIG. 1 in the following points. That is, in the discharge lamp lighting device 5d shown in FIG. 9, the transformer T1 includes a secondary winding 119 for supplying a DC voltage E in addition to the secondary windings 110, 111, and 112. One end of the secondary winding 119 is connected to the ground, and the other end is connected to the resistors R6 and R8 in the filament defect detection circuit 108 via the rectifying diode D6 and the resistor R19. The secondary winding 119, the diode D6, and the resistor R19 constitute a DC voltage source 115c. That is, the voltage generated at the output voltage of the secondary winding 119 at the connection point between the drain of the transistor Q2 and the resistor R5 and the capacitor C1 is used as the DC voltage E via the diode D6 and the resistor R19.

  Since the other configuration is the same as that of the discharge lamp lighting device 5 shown in FIG. 1, the description thereof will be omitted, and the operation of the present embodiment will be described below.

  First, the operation of turning on the discharge lamps FL1 and FL2 in the discharge lamp lighting device 5d and the operation of not turning on or turning off the discharge lamp by detecting a defect such as a connection failure are the same as those of the discharge lamp lighting device 5 shown in FIG. Since it is the same, the description is omitted.

  Next, the operation of the DC voltage source 115c will be described. First, since the inverter operation of the transistors Q1 and Q2 is started by the inverter control circuit 106a and the power supply for lighting the discharge lamps FL1 and FL2 is started, no current flows through the transformer T1, so the secondary winding 119. No voltage is generated. Then, the DC voltage E is output after the inverter operation is started. Accordingly, the DC voltage source 115c functions in the same manner as the DC voltage source 115 shown in FIG. 2, and therefore the discharge lamp lighting device 5d shown in FIG. 9 and the lighting fixture using the same are the discharge lamp lighting device shown in FIG. 5 can be produced.

(Sixth embodiment)
Next, a discharge lamp lighting device according to a sixth embodiment of the present invention will be described. FIG. 10 is a circuit diagram showing an example of the configuration of a discharge lamp lighting device according to the sixth embodiment of the present invention.

  The discharge lamp lighting device 5e shown in FIG. 10 is different from the discharge lamp lighting device 5a shown in FIG. 5 in the following points. That is, in the discharge lamp lighting device 5e shown in FIG. 10, the resistors R7 and R10 of the filament defect detection circuit 108 and the resistance R13 of the no-load detection circuit 109 are partially shared in the discharge lamp lighting device 5a shown in FIG. This is an example. In the discharge lamp lighting device 5e shown in FIG. 10, the transformer T1 includes a secondary winding 120 in addition to the secondary windings 110, 111, and 112.

  One end of the secondary winding 120 is connected to the ground, and the other end is connected to the connection point between the cathode of the diode D4 and the resistor R4 in the no-load detection circuit 109a via the diode D7 and the resistor R20. ing. The no-load detection circuit 109a includes a capacitor C12 instead of the Zener diode ZD1, and a connection point between the resistor R13 and the capacitor C12 is connected to the comparator 105 via the diode D8.

  Since the other configuration is the same as that of the discharge lamp lighting device 5a shown in FIG. 5, the description thereof will be omitted, and the operation of the present embodiment will be described below.

  First, the operation of turning on the discharge lamps FL1 and FL2 in the discharge lamp lighting device 5e and the operation of not turning on or turning off the discharge lamp by detecting a failure such as a connection failure are the same as those of the discharge lamp lighting device 5a shown in FIG. Since it is the same, the description is omitted.

In the discharge lamp lighting device 5e, since the series circuit of the resistor R13 and the capacitor C12 of the no-load detection circuit 109 is connected in parallel with the discharge lamp FL2, it is applied to the capacitor C12 after the discharge lamps FL1 and FL2 are turned on. There is no DC component in the applied voltage, and the charging voltage of the capacitor C12 is almost 0V. On the other hand, when the inverter control circuit 106 starts the inverter operation of the transistors Q1 and Q2 and a current flows through the transformer T1, the voltage output from the secondary winding 120 is rectified by the diode D7 and the capacitor C10 is charged. Thereby, the charging voltage V _C10 applied to the comparator 104 is maintained at a level exceeding the reference voltage VrefN, and the inverter operation is continued.

Next, when the contact (4) is poorly connected, current flows from the DC voltage source 115a to the path to the ground via the resistor R6, the secondary winding 111, the resistor R13, the diode D4, and the resistor R14. Thus, the DC voltage E is divided by the resistors R6, R13, and R14. The capacitor C12 is charged by the divided voltage, and as a result of the charge voltage V _C8 exceeding VrefE, the output signal VEL of the comparator 105 is output to the inverter control circuit 106 at a high level. Then, the inverter operation is stopped by the inverter control circuit 106, the power supply to the discharge lamps FL1, FL2 is stopped, and the discharge lamps FL1, FL2 are turned off.

  Thereby, the discharge lamp lighting device 5e shown in FIG. 10 and the lighting fixture using the same can exhibit the same effect as the discharge lamp lighting device 5 shown in FIG.

It is a perspective view which shows an example of the external appearance of the lighting fixture which concerns on the 1st Embodiment of this invention. It is a circuit diagram which shows an example of a structure of the discharge lamp lighting device shown in FIG. It is a figure for demonstrating operation | movement of the discharge lamp lighting device shown in FIG. It is a figure for demonstrating operation | movement of the discharge lamp lighting device shown in FIG. It is a circuit diagram which shows an example of a structure of the discharge lamp lighting device which concerns on the 2nd Embodiment of this invention. It is a figure which shows the direct current | flow equivalent circuit of the discharge lamp lighting device before an inverter operation | movement is started. It is a circuit diagram which shows an example of a structure of the discharge lamp lighting device by the 3rd Embodiment of this invention. It is a circuit diagram which shows an example of a structure of the discharge lamp lighting device by the 4th Embodiment of this invention. It is a circuit diagram which shows an example of a structure of the discharge lamp lighting device by the 5th Embodiment of this invention. It is a circuit diagram which shows an example of a structure of the discharge lamp lighting device by the 6th Embodiment of this invention. It is a circuit diagram which shows the structure of the discharge lamp lighting device which concerns on background art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Lighting fixture main body 4a, 4b, 4c, 4d Connector 5, 5a, 5b, 5c, 5d, 5e Discharge lamp lighting device 101 Power supply connector 102 Power supply part (DC voltage source)
103 control circuit unit 104, 105 comparator 106, 106a inverter control circuit (first and second control units, preheating control unit)
107, 107a Drive circuit 108 Filament defect detection circuit 109, 109a No-load detection circuit (no-load detection unit)
110 Secondary winding 111 Secondary winding (first secondary winding)
112 Secondary winding 113 No-load detection circuit 114, 116 DC detection circuit 115, 115a, 115b, 115c DC voltage source (voltage source for detection)
118 Preheating cut circuit 119 Secondary winding (second secondary winding)
120 Secondary winding (third secondary winding)
C1 capacitor (fifth capacitor)
C10 capacitor (first capacitor)
C4 capacitor (4th and 6th capacitors)
C6 capacitor (third capacitor)
C8 capacitor (second capacitor)
D1, D2, D3, D4, D5, D6, D7, D8 Diode F1, F2, F3, F4 Filament FL1, FL2 Discharge lamp Q1 Transistor (first switching element)
Q2 transistor (second switching element)
Q3 transistor Q4 transistor (third switching element)
R12 resistor (first resistor)
R7 resistance (fifth resistance)
R8 resistance (second resistance)
R9 resistance (third resistance)
R10 resistor (fourth resistor)
T1 transformer (second transformer)
T2 transformer (first transformer)
ZD1 Zener diode

Claims (8)

A plurality of discharge lamps having a filament for lighting at both ends are configured as a series circuit of discharge lamps by connecting the filaments in series, and a reception unit that receives power supply from the outside, and power received by the reception unit A power supply unit that emits light from the plurality of discharge lamps by supplying a lighting voltage to a series circuit of the discharge lamps, and an abnormality detection unit that detects defects in the filament units connected in series. A discharge lamp lighting device comprising:
The abnormality detection unit includes a no-load detection unit for detecting a defect of the filament unit connected in series when the reception unit starts receiving power from the outside, and the power supply unit A filament defect detection unit for detecting a defect of the filament unit connected in series when the lighting voltage is supplied by,
The no-load detection unit is charged by a first resistor that applies the lighting voltage to a high potential side pole in the filament series circuit and a current derived from a low potential side pole in the filament series circuit. The first capacitor to be performed, and when the charging voltage of the first capacitor exceeds a preset first reference voltage, power is supplied from the power supply unit to the series circuit of the discharge lamp, A first control unit that stops power supply by the power supply unit when a charging voltage of the first capacitor is equal to or lower than the first reference voltage;
The filament defect detection unit includes a detection voltage source that outputs a detection voltage for detecting the defect, a series circuit including second, third, and fourth resistors that divides the detection voltage, A second capacitor connected in parallel with a fourth resistor; and a fifth resistor connecting a connection point between the third and fourth resistors and the pole on the low potential side. The connection point between the third resistors and the high potential side pole are connected, and the voltage generated at the connection point between the third and fourth resistors is the second reference voltage set in advance. A second control unit for stopping the power supply by the power supply unit when exceeding,
The discharge lamp lighting device, wherein the detection voltage source starts output of the detection voltage after power supply by the power supply unit is started. The power supply unit includes a DC voltage source that outputs a DC voltage, and a series circuit including a first switching element and a second switching element to which the DC voltage output from the DC voltage source is applied, A rectangular wave voltage output from a connection point between the first and second switching elements by alternately turning on and off the first and second switching elements is used as a lighting voltage to the series circuit of the discharge lamp. To supply,
The discharge lamp lighting device according to claim 1, wherein the detection voltage source outputs the rectangular wave voltage as the detection voltage. A series circuit including a third capacitor, a first transformer, and a third switching element connected in parallel with the second switching element;
A secondary winding of the first transformer is connected to the high potential side pole and the low potential side pole via a fourth capacitor;
By turning on the third switching element before starting the light emission of the discharge lamp, a preheating current is output from the secondary winding of the transformer to the series circuit of the filament, and after the light emission of the discharge lamp is started. The discharge lamp lighting device according to claim 1, further comprising a preheating control unit that turns off the third switching element.   4. The discharge lamp lighting device according to claim 3, wherein the detection voltage source outputs a voltage between the third capacitor and the first transformer as the detection voltage. The power supply unit includes a DC voltage source that outputs a DC voltage between a positive terminal and a negative terminal, and a series circuit including a first switching element and a second switching element connected between the positive terminal and the negative terminal. By alternately turning on and off the first and second switching elements, a rectangular wave voltage output from a connection point between the first and second switching elements is converted into a fifth capacitor and a second transformer. And is supplied as a lighting voltage to the series circuit of the discharge lamp through
The first secondary winding of the second transformer is connected to the high potential side pole and the low potential side pole via a sixth capacitor,
2. The discharge lamp lighting according to claim 1, wherein the detection voltage source outputs a voltage output from a second secondary winding in the second transformer as the detection voltage. apparatus. The power supply unit includes a DC voltage source that outputs a DC voltage between a positive terminal and a negative terminal, and a series circuit including a first switching element and a second switching element connected between the positive terminal and the negative terminal. By alternately turning on and off the first and second switching elements, a rectangular wave voltage output from a connection point between the first and second switching elements is converted into a fifth capacitor and a second transformer. And is supplied as electric power to the series circuit of the discharge lamp through
The first secondary winding of the second transformer is connected to the high potential side pole and the low potential side pole via a sixth capacitor,
The voltage output from the third secondary winding in the second transformer is rectified instead of including the fifth resistor, and the first capacitor is charged with this voltage. The discharge lamp lighting device according to 1.   The second control unit in the filament defect detection unit may receive the power even when the second reference voltage is exceeded within a preset period after the supply of power is received by the reception unit. The discharge lamp lighting device according to any one of claims 1 to 6, wherein the supply is not stopped.   A lighting fixture comprising a discharge lamp and a discharge lamp lighting device for lighting the discharge lamp, wherein the discharge lamp lighting device is the discharge lamp lighting device according to any one of claims 1 to 7. .

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