JP6350139B2 - Discharge lamp lighting device, lighting device, and control method of discharge lamp lighting device - Google Patents

Description

  The present invention relates to a discharge lamp lighting device, an illumination device using the same, and a control method for the discharge lamp lighting device.

  Patent Document 1 discloses a high pressure discharge lamp lighting device that can detect the occurrence of an abnormality at an early stage and quickly shift to a protection operation. This high pressure discharge lamp lighting device includes a lighting circuit for supplying power to the high pressure discharge lamp, a starting circuit for applying high voltage to the high pressure discharge lamp to start, and a lighting circuit current measurement for measuring a lighting circuit current flowing through the lighting circuit. Provide circuit. Further, the high pressure discharge lamp lighting device generates a voltage in the starting circuit before starting the high pressure discharge lamp, and when the lighting circuit current value is out of a preset current value range, a predetermined protective operation is performed. The control means which performs is provided.

Japanese Patent No. 5035748

  According to the configuration of Patent Document 1, it is possible to perform a quick protection operation when an abnormality occurs. In this configuration, if the abnormality occurrence location is specified, such as whether the abnormality occurs on the discharge lamp side or the discharge lamp lighting device side, it is advantageous in maintenance management. . For example, when it is determined that an abnormality has occurred on the discharge lamp side, the discharge lamp and its peripheral wiring may be replaced, and the discharge lamp lighting device can be used continuously. On the other hand, if it is determined that an abnormality has occurred on the discharge lamp lighting device side, the discharge lamp lighting device may be replaced, and the discharge lamp can be used continuously. Furthermore, if an abnormality occurrence location is identified in the discharge lamp lighting device, the part at that location can be replaced and the remaining parts can be used continuously, or information on the abnormality occurrence location can be used for future quality control. It can be used for. In addition, since any abnormality or failure does not occur frequently in any case, it is not preferable in terms of cost to provide a separate detection circuit on the hardware in order to identify the abnormality occurrence location. .

  Accordingly, the present invention provides a discharge lamp lighting device capable of specifying an abnormality occurrence location without requiring an additional detection circuit component, an illumination device using the discharge lamp lighting device, and a control method for the discharge lamp lighting device. And

  A discharge lamp lighting device according to a first aspect of the present invention includes a DC power supply circuit that outputs a DC output voltage, first to fourth switching elements, a series circuit of first and second switching elements, and A series circuit of the third and fourth switching elements is connected to the output side of the DC power supply circuit, the connection point of the first switching element and the second switching element, and the connection of the third switching element and the fourth switching element. A full bridge circuit whose points are connected via the discharge lamp, a current detection circuit for detecting the output current of the DC power supply circuit, a set of the first and third switching elements when the discharge lamp is not lit, Applying a one-side on mode in which one of the fourth switching element sets is turned on and the other set is turned off, the output current detected by the current detection circuit is If it exceeds a value, and a control section for determining that there is an abnormality in the discharge lamp lighting in the device.

  According to the above-described discharge lamp lighting device, when the one-side on mode in which only one set of either the high-side switching element or the low-side switching element in the full bridge circuit is applied, the output current of the DC power supply circuit is When the threshold value is exceeded, it is specified that there is an abnormality in the discharge lamp lighting device. This makes it possible to distinguish an abnormality in the discharge lamp lighting device from an abnormality on the discharge lamp side. In other words, it is possible to identify an abnormality occurrence location without requiring an additional detection circuit component.

  A discharge lamp lighting device according to a second aspect of the present invention includes a DC power supply circuit that outputs a DC output voltage, and first to fourth switching elements, and includes a series circuit of first and second switching elements. A first arm and a second arm composed of a series circuit of third and fourth switching elements are connected to the output side of the DC power supply circuit, and a connection point between the first switching element and the second switching element A full bridge circuit in which the connection point of the switching element 3 and the fourth switching element are connected via the discharge lamp, a current detection circuit that detects the output current of the DC power supply circuit, and the first when the discharge lamp is not lit A single on mode in which one of the fourth switching elements is turned on and the remaining switching elements are turned off is applied by the current detection circuit. When the output current is issued exceeds the threshold value, and a control section for determining that there is an abnormality in the discharge lamp lighting in the device.

  According to the discharge lamp lighting device described above, when the output current of the DC power supply circuit exceeds the threshold when applying the single on mode in which one switching element in the full bridge circuit is turned on and the remaining switching elements are turned off. It is specified that there is an abnormality in the discharge lamp lighting device. This makes it possible to distinguish an abnormality in the discharge lamp lighting device from an abnormality on the discharge lamp side. In other words, it is possible to identify an abnormality occurrence location without requiring an additional detection circuit component.

  Further, the control unit is configured to determine that there is an abnormality in the other switching element included in the same arm as the switching element that is turned on when the output current exceeds the threshold value. As a result, it is possible to identify an abnormality in the discharge lamp lighting device by identifying a switching element having an abnormality. That is, it is possible to more specifically identify the location where an abnormality has occurred without requiring additional detection circuit components.

  A discharge lamp lighting device according to a third aspect of the present invention includes a DC power supply circuit that outputs a DC output voltage, and first to fourth switching elements, and includes a series circuit of first and second switching elements. A first arm and a second arm composed of a series circuit of third and fourth switching elements are connected to the output side of the DC power supply circuit, and a connection point between the first switching element and the second switching element A full bridge circuit in which the connection point of the switching element 3 and the fourth switching element are connected via the discharge lamp, a current detection circuit that detects the output current of the DC power supply circuit, and the first when the discharge lamp is not lit A one-side on mode in which one of the third switching element group and the second and fourth switching element groups is turned on and the other group is turned off; and Itaru and a fourth one of the applicable control unit alone on mode for the remainder of the switching element in an off state with the ON state of the switching element of the switching element. The control unit further applies a single on mode in which one of the switching elements is turned off when the output current detected by the current detection circuit exceeds the threshold in the one side on mode. When the output current detected by the current detection circuit exceeds the threshold value, it is configured to determine that there is an abnormality in the other switching element included in the same arm as the switching element that is turned on.

  According to the above discharge lamp lighting device, when the one-side on mode is applied and an abnormality is determined, the single on-state obtained by turning off one of the two switching elements that are turned on in the same mode The abnormality for each switching element is determined by the mode. As a result, it is possible to distinguish an abnormality in the discharge lamp lighting device from an abnormality on the discharge lamp side, identify an abnormal switching element, and perform a determination process with a small number of processes. That is, it is possible to more specifically and quickly identify the location where an abnormality has occurred without requiring additional detection circuit components.

  In each of the discharge lamp lighting devices described above, the output voltage of the DC power supply circuit when the one-side on mode or the single-on mode is applied is preferably lower than the output voltage of the DC power supply circuit when the discharge lamp is started or turned on. . This achieves power saving and further prevention of failure (when there is an abnormality).

  Moreover, it is preferable that each said discharge lamp lighting device is further provided with the output means which outputs the determination result by a control part. Accordingly, the user can grasp the location where the abnormality has occurred, and can continue to use the discharge lamp lighting device by exchanging or repairing only the failed location, which is advantageous in maintenance management. Further, by managing information on the location where an abnormality has occurred, it is possible to utilize such information for subsequent quality control and the like.

  In addition, this invention also includes an illuminating device provided with one of the said discharge lamp lighting devices and a discharge lamp. Furthermore, the present invention includes a control method for the discharge lamp lighting device executed in each of the discharge lamp lighting devices described above.

It is a circuit diagram which shows the discharge lamp lighting device by each embodiment of this invention. It is a flowchart which shows the control method of the discharge lamp lighting device by the 1st Embodiment of this invention. It is a flowchart which shows the control method of the discharge lamp lighting device by the 2nd Embodiment of this invention. It is a flowchart which shows the control method of the discharge lamp lighting device by the 3rd Embodiment of this invention.

<Basic configuration of discharge lamp lighting device>
FIG. 1 shows a discharge lamp lighting device 1 (hereinafter referred to as “lighting device 1”) according to each embodiment of the present invention. The lighting device 1 and the discharge lamp 9 constitute the lighting device 10. Input power from an AC power source AC such as commercial power is input to the lighting device 1, and output power from the lighting device 1 is supplied to the discharge lamp 9. In each embodiment described below, it is assumed that the lighting device 1 of FIG. 1 is used.

  The lighting device 1 includes a rectifier circuit 2, a step-up converter 3, a step-down converter 4, a full bridge circuit 5, a detection circuit 6, a start circuit 7, and a control unit 8. In the present embodiment, the discharge lamp 9 is a high-pressure discharge lamp. The rectifier circuit 2 is composed of a diode bridge, and full-wave rectifies the input voltage from the AC power supply AC. The rectifier circuit 2, the step-up converter 3 and the step-down converter 4 constitute a DC power supply circuit. However, the rectifier circuit 2 is not required when a DC power supply is input as an input power supply instead of an AC power supply.

  Boost converter 3 includes switching element 31, coil 32, diode 33, and smoothing capacitor 34, and boosts the rectified output of rectifier circuit 2 to direct current. Boost converter 3 also functions as a power factor correction circuit. When the switching element 31 is turned on, current flows from the coil 32 to the switching element 31, and energy is stored in the coil 32. When the switching element 31 is turned off, the current stored in the coil 32 causes a current to flow from the coil 32 to the diode 33 to the smoothing capacitor 34, and the smoothing capacitor 34 is charged. The switching element 31 is driven by a driver circuit included in the control unit 8 to be described later, and the ON width (on duty) of the switching element 31 is determined by the control unit 8. That is, the control unit 8 performs PWM control of the switching element 31 and determines the output voltage of the boost converter 3 (hereinafter referred to as “output voltage Vdc”).

  The step-down converter 4 includes a switching element 41, a coil 42, a diode 43, and a capacitor 44, and outputs a limited voltage and current from the step-up output of the step-up converter 3. When the switching element 41 is turned on, a current flows through the switching element 41 → the coil 42 → the load (for example, the full bridge circuit 5 and the discharge lamp 9), and energy is stored in the coil 42. When the switching element 41 is turned off, current flows from the coil 42 to the load to the diode 43 due to the energy stored in the coil 42. Capacitor 44 smoothes the output of step-down converter 4. The switching element 41 is driven by a driver circuit included in the control unit 8, and the ON width (on duty) of the switching element 41 is determined by the control unit 8. That is, the switching element 41 is PWM-controlled by the control unit 8 to determine the output voltage (hereinafter referred to as “output voltage Vout”) and the output current (hereinafter referred to as “output current Iout”) of the step-down converter 4.

  The full bridge circuit 5 includes switching elements (SW) 51, 52, 53 and 54. In this specification, the switching element generally represents a bipolar transistor such as an IGBT, a MOSFET, or the like. In other words, each switching element in this specification may be any of IGBT, MOSFET, and the like. A first arm composed of a series circuit of switching elements 51 and 52 and a second arm composed of a series circuit of switching elements 53 and 54 are connected to the output side of the step-down converter 4, and a connection point between the switching elements 51 and 52. The connection point of the switching element 53 and the switching element 54 is connected via the discharge lamp 9. In the following description, as shown in FIG. 1, the line to which the common terminals (collector terminal, drain terminal) of the switching elements 51 and 53 are connected is referred to as a high potential line L1, and the common terminal (emitter) of the switching elements 52 and 54 is connected. A line to which a terminal and a source terminal are connected is referred to as a low potential line L2.

  Each of the switching elements 51 to 54 is turned on and off by a driver included in the control unit 8. As will be described in detail later, the control unit 8 can individually turn on or off one or two of the switching elements 51 to 54. For example, at the time of normal lamp starting and lighting, the group of switching elements 51 and 54 and the group of switching elements 52 and 53 are alternately turned on and off at a frequency of about 50 Hz to 1 kHz, and the DC output of the step-down converter 4 Is converted into an alternating current, and an alternating current output is supplied to the discharge lamp 9. As a result, a rectangular wave voltage having the above frequency is applied to the discharge lamp 9, and a current corresponding thereto is supplied to the discharge lamp 9 during normal lighting.

  The detection circuit 6 includes a voltage detection circuit composed of a series circuit of resistors 61 and 62 and a current detection circuit 63. The resistors 61 and 62 are connected in parallel to the output terminal of the step-down converter 4 and detect the output voltage Vout. A voltage generated in the resistor 62 shown at the node A is output to the control unit 8 as a detection voltage. The current detection circuit 63 is composed of a shunt resistor or a low resistance element of about 0.1 to 1Ω for current measurement, and is inserted in the current path between the step-down converter 4 and the full bridge circuit 5 to detect the output current Iout. A voltage generated in the current detection circuit 63 shown in the node B is output to the control unit 8 as a detection current. In the following description, the detection voltage and the detection current are either a voltage generated in the resistor 62 of the voltage detection circuit and the current detection circuit 63, respectively, or an output voltage Vout and an output current Iout represented by these voltages. It shall be said.

  The start circuit 7 includes a resistor 71, a capacitor 72, a discharge gap 73, and a pulse transformer 74, and is configured to apply a start pulse to the discharge lamp 9 when the discharge lamp 9 is started. When the step-down converter 4 is activated, the output voltage is charged to the capacitor 72 via the resistor 71. When the charging voltage of the capacitor 72 exceeds the breakdown voltage of the discharge gap 73, the discharge gap 73 is conducted and the voltage of the capacitor 72 is applied to the primary winding of the pulse transformer 74. In response to this, a pulse voltage corresponding to the turn ratio of the pulse transformer 74 is generated in the secondary winding connected in series with the discharge lamp 9, and this pulse voltage is superimposed on the output voltage of the full bridge circuit 5 and released. Applied to the lamp 9. With this pulse superimposed voltage, the discharge lamp 9 breaks down and starts discharging. Since the starting circuit 7 is stopped before and after the starting operation of the discharge lamp 9, it does not substantially affect the lighting operation of the discharge lamp.

  As described above, the detection voltage of the node A and the detection current of the node B are input to the control unit 8. It is assumed that the control power supply of the control unit 8 is appropriately supplied with power (for example, from a predetermined location of the step-up converter 3 or the step-down converter 4). The control unit 8 drives the switching element 31 of the step-up converter 3, the switching element 41 of the step-down converter 4, and the switching elements 51 to 54 of the full bridge circuit 5.

  Specifically, for control of the switching element 31, the control unit 8 performs PWM control on the switching element 31 so that the output voltage Vdc becomes a predetermined value. For example, in the boost converter 3 and the control unit 8, the output voltage Vdc may be feedforward controlled, or the output voltage Vdc detected by an output voltage detection circuit (not shown) is matched with the voltage target value. Vdc may be feedback controlled. It is assumed that the output voltage Vdc is appropriately set according to each operation described later.

  Regarding the control of the switching element 41, the control unit 8 also performs PWM control of the switching element 41 of the step-down converter 4 so that the detected voltage or the detected current matches the voltage target value or the current target value. That is, in the step-down converter 4 and the control unit 8, the output voltage Vout or the output current Iout is feedback controlled. Alternatively, the control unit 8 may perform PWM control of the switching element 41 of the step-down converter 4 so that the product of the detection current and the detection voltage matches the power target value. In this case, in the step-down converter 4 and the control unit 8, the output power is feedback-controlled.

  Regarding the control of the switching elements 51 to 54, the controller 8 starts the lighting circuit 1 and before starting the discharge lamp 9, that is, after starting the boost converter 3 and the step-down converter 4 and starting circuit 7. Before is activated, switching for abnormality determination operation is performed. As will be described in detail later, in the abnormality determination operation, a predetermined switching element among the switching elements 51 to 54 of the full bridge circuit 5 is turned on, and an abnormality (failure) is caused by the value of the output current Iout in that state. The presence or absence and / or the location is determined. That is, in the abnormality determination operation, the presence / absence of abnormality inside the lighting device 1 (particularly, the full bridge circuit 5) and the presence / absence of abnormality between the output end of the lighting device 1 and the discharge lamp 9 are determined and identified. For convenience of explanation, regarding the location where an abnormality has occurred, the inside of the lighting device 1 is referred to as “circuit side”, and the portion from the output end of the lighting device 1 to the discharge lamp 9 (including the discharge lamp 9) is referred to as “lamp”. "Side". Further, in this specification, unless otherwise specified, abnormality and failure are substantially synonymous.

  When it is determined that there is an abnormality on the circuit side or the lamp side, the control unit 8 stops the operation of the step-down converter 4, the full bridge circuit 5, or both, and latches this stop state. When the abnormality is on the circuit side, it is desirable to stop at least the step-down converter 4, preferably the step-down converter 4 and the full bridge circuit 5, for the subsequent repair or replacement of the lighting device 1. On the other hand, if the abnormality is on the lamp side, at least the full bridge circuit 5 is stopped, preferably the step-down converter 4 and the full bridge circuit 5 are stopped, in order to replace the discharge lamp 9 or its peripheral wiring. desirable. In any case, it is desirable that boost converter 3 is also stopped by control unit 8 (in the case of a circuit that can be stopped from control unit 8).

  In the abnormality determination operation in which the discharge lamp 9 is in a non-lighting state, the control unit 8 performs feedback control of the output voltage Vout on the premise of a no-load state caused by a normal state on the circuit side and the lamp side. It is assumed that the output voltage Vout during the abnormality determination operation is set to a predetermined voltage V1. Since this voltage V1 is not a voltage intended for starting or lighting the discharge lamp 9, an output voltage for starting the discharge lamp 9 is used from the viewpoint of power saving and prevention of further failure (when there is an abnormality). The voltage is preferably lower than Vout (V2) and the output voltage Vout for lighting (V3 (V2> V3)).

  The control unit 8 is preferably connected to an output unit 80 that outputs a determination result (for example, notifies the user). The output means 80 is an LED indicator that visually outputs the result of determination by the control unit 8 according to the light emission mode (the presence or absence of light emission, the light emission period, the change in light emission color, the change in light emission intensity, etc.), characters, figures, etc. Any liquid crystal display screen may be used. Further, the output unit 80 may be a speaker or the like that outputs the determination result by a buzzer sound, voice guidance, or the like. Alternatively, the output unit 80 may be a monitor screen of a computer that can communicate with the control unit 8. The output unit 80 is configured to output whether the abnormality is on the circuit side or the lamp side when the abnormality is determined. Further, the output unit 80 may output a determination result indicating normality together with or instead of the determination result indicating abnormality. The output unit 80 may be integrated with the control unit 8 or may be provided separately. Further, the connection between the control unit 8 and the output means 80 may be wired or wireless. Furthermore, the output means 80 may be provided with a storage means for recording the determination result.

<First Embodiment>
In the first embodiment, in the above-described abnormality determination operation, a high-side on mode in which only the high-side switching element of the full bridge circuit 5 is turned on, a low-side on mode in which only the low-side switching element is turned on, and normal operation A diagonal on mode is used in which the switching elements are turned on in the same combination as the time. Note that the high-side on mode and the low-side on mode are collectively referred to as a one-side on mode or a part of them.

  The high side on mode refers to a mode in which the pair of switching elements 51 and 53 is turned on and the pair of switching elements 52 and 54 is turned off. An abnormality such as a short circuit failure of the switching element 52 or 54 can be detected by the high side on mode. Specifically, even when the switching elements 51 and 53 are in the on state when the switching elements 52 and 54 are normal, the discharge lamp 9 is before starting (open state before dielectric breakdown), so the high potential line There is no conduction between L1 and the low potential line L2. Therefore, the output current Iout does not flow through the current detection circuit 63. On the other hand, when at least one of the switching elements 52 and 54 is short-circuited, when the switching elements 51 and 53 are turned on, the high potential line L1 and the low potential line L2 are electrically connected, and the current detection circuit 63 is connected. An output current Iout flows. The relationship between the presence / absence of a short circuit failure of the switching element 52 or 54 and the output current Iout is obtained regardless of the presence / absence of a short circuit failure on the lamp side.

  Therefore, in the high-side on mode, the control unit 8 determines that at least one of the switching elements 52 and 54 is abnormal when the current Iout exceeds the threshold value Ith, and otherwise the switching elements 52 and 54 are It can be determined that it is normal.

  The low side on mode refers to a mode in which the pair of switching elements 52 and 54 is turned on and the pair of switching elements 51 and 53 is turned off. An abnormality such as a short circuit failure of the switching element 51 or 53 can be detected by the low side on mode. Specifically, even when the switching elements 51 and 53 are normal and the switching elements 52 and 54 are turned on, the discharge lamp 9 is in an open state, and therefore, between the high potential line L1 and the low potential line L2. Does not conduct. Therefore, the output current Iout does not flow through the current detection circuit 63. On the other hand, when at least one of the switching elements 51 and 53 is short-circuited, when the switching elements 52 and 54 are turned on, the high potential line L1 and the low potential line L2 are electrically connected, and the current detection circuit 63 is connected. An output current Iout flows. As in the case of the high-side on mode, the relationship between the presence / absence of the short-circuit failure of the switching element 51 or 53 and the output current Iout is obtained regardless of the presence / absence of the short-circuit failure on the lamp side.

  Therefore, in the low-side on mode, the control unit 8 determines that at least one of the switching elements 51 and 53 is abnormal when the current Iout exceeds the threshold value Ith, and the switching elements 51 and 53 are normal in other cases. Can be determined.

  The diagonal on mode is a first direction in which the pair of switching elements 51 and 54 is turned on and the pair of switching elements 52 and 53 is turned off as in the case of starting or lighting the discharge lamp 9. Mode or a second direction mode in which the pair of switching elements 52 and 53 is turned on and the pair of switching elements 51 and 54 is turned off. In the combined use of the high side on mode and the low side on mode, an abnormality such as a short circuit failure on the lamp side can be detected by the diagonal on mode. Specifically, for example, in the first direction mode, even if the switching elements 52 and 53 are normal and there is no short-circuit failure on the lamp side, the discharge lamp 9 remains open even if the switching elements 51 and 54 are turned on. Therefore, there is no conduction between the high potential line L1 and the low potential line L2. Therefore, the output current Iout does not flow through the current detection circuit 63. On the other hand, when there is a short circuit failure on the lamp side, when the switching elements 51 and 54 are turned on, the high potential line L1 and the low potential line L2 are conducted, and the output current Iout flows through the current detection circuit 63. The detection principle is the same in the second direction mode. Therefore, as for the diagonal on mode, one of the first direction mode and the second direction mode may be performed.

  As described above, in the diagonal on mode, the control unit 8 determines that the lamp side is abnormal when the current Iout exceeds the threshold value Ith in the combined use of the high side on mode and the low side on mode. It can be determined that the lamp side is normal.

  As described above, the control unit 8 can identify and discriminate between the abnormality on the circuit side and the abnormality on the lamp side by applying the high side on mode, the low side on mode, and the diagonal on mode. Further, when an abnormality is determined in the high-side on mode or the low-side on mode, the output means 80 outputs a circuit-side abnormality, and when an abnormality is determined in the diagonal-on mode, the lamp-side abnormality is output. Can be output. Further, the output means 80 outputs an abnormality of the switching elements 52 and 54 when an abnormality is determined in the high side on mode, and outputs an abnormality of the switching elements 51 and 53 when an abnormality is determined in the low side on mode. An abnormality may be output.

FIG. 2 shows a flowchart of the control method of this embodiment.
When AC power supply AC is turned on to lighting device 1, output voltage Vout of step-down converter 4 is set to a predetermined voltage V1 in step S100. At this time, the switching elements 51 to 54 are all in the off state.

  In step S101, the control unit 8 determines whether or not the output current Iout of the step-down converter 4 exceeds a threshold value Ith. If the output current Iout exceeds the threshold value Ith in step S101 (step S101, YES), the control unit 8 determines that there is an abnormality on the circuit side, and the process proceeds to step S115. This event may occur, for example, in the full bridge circuit 5 when at least one of the first arm and the second arm is short-circuited as a whole. In step S101, when the output current Iout does not exceed the threshold value Ith (step S101, NO), the process proceeds to step S110.

In step S110, the control unit 8 applies the high side on mode.
In step S111, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. If the output current Iout exceeds the threshold value Ith in step S111 (step S111, YES), the control unit 8 determines that there is an abnormality on the circuit side, and the process proceeds to step S115. As described above, this event occurs when at least one of the low-side switching elements 52 and 54 is short-circuited. On the other hand, if the output current Iout does not exceed the threshold value Ith in step S111 (step S111, NO), it is determined that the switching elements 52 and 54 are normal, and the process proceeds to step S112.

In step S112, the control unit 8 applies the low side on mode.
In step S113, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S113, when the output current Iout exceeds the threshold value Ith (step S113, YES), the control unit 8 determines that there is an abnormality on the circuit side, and the process proceeds to step S115. As described above, this event occurs when at least one of the high-side switching elements 51 and 53 is short-circuited. On the other hand, if the output current Iout does not exceed the threshold value Ith in step S113 (NO in step S113), it is determined that the switching elements 51 and 53 are normal, and the process proceeds to step S140.

  In step S115, the control unit 8 identifies an abnormality on the circuit side and stops the operation of the step-down converter 4, the full bridge circuit 5, or both. At this time, the output unit 80 may output whether an abnormality has occurred on the circuit side or whether the abnormality has occurred on the high side or the low side of the full bridge circuit 5.

In step S140, the control unit 8 applies the diagonal on mode.
In step S141, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S141, when the output current Iout exceeds the threshold value Ith (step S141, YES), the control unit 8 determines that the lamp side is abnormal, and the process proceeds to step S145. On the other hand, when the output current Iout does not exceed the threshold value Ith in step S141 (NO in step S141), the control unit 8 determines that there is no abnormality on the circuit side and the lamp side, and the process proceeds to step S200.

  In step S145, the control unit 8 identifies an abnormality on the lamp side, and stops the operation of the step-down converter 4, the full bridge circuit 5, or both. At this time, the output unit 80 may output that an abnormality has occurred on the lamp side.

  In the above flow, the execution order of the processing related to the high side on mode (S110 and S111) and the processing related to the low side on mode (S112 and S113) may be reversed. Moreover, the process (S140-S145) regarding diagonal on mode may be performed before the process regarding high side on mode and low side on mode. In this case, no abnormality is detected in the high side on mode and the low side on mode after it is detected that there is an abnormality on the circuit side or the lamp side in the diagonal on mode (in a state where either is not discriminated). On the other hand, an abnormality on the lamp side is identified inductively.

In step S200, the control unit 8 controls the step-up converter 3 and the step-down converter 4 so that the output voltage Vout becomes a voltage V2 suitable for starting. Thereby, the starting operation of the discharge lamp 9 is performed by the operation of the starting circuit 7 or the like.
When the discharge lamp 9 is broken down in step S200, in step S250, the control unit 8 controls the step-up converter 3 and the step-down converter 4 so that the output voltage Vout becomes a voltage V3 suitable for lighting. Normal lighting operation is performed.

  As described above, according to the lighting device 1 of the present embodiment, when the discharge lamp 9 is not lit, only one of the high-side switching elements 51 and 53 and the low-side switching elements 52 and 54 is turned on. One side on mode is applied. Then, when the detected output current Iout exceeds the threshold value Ith, an abnormality on the circuit side is determined. As a result, it is possible to distinguish the abnormality on the circuit side from the abnormality on the lamp side (regardless of the presence or absence of abnormality on the lamp side). Therefore, in the lighting device 1, it is possible to specify an abnormality occurrence place without requiring an additional detection circuit component. Even if an abnormality occurs in the lighting device 10, the user can continue to use the lighting device 10 by replacing only the failed member (circuit-side member or lamp-side member). This is advantageous in maintenance management. In addition, it is possible to record whether an abnormality has occurred in the high-side switching element and the low-side switching element, and to use the recorded information for subsequent quality control and the like.

<Second Embodiment>
In the first embodiment, the configuration in which the one-side on mode is used in the abnormality determination operation has been described. However, in the present embodiment, the single switching element is turned on instead of the one-side on mode. Indicates the configuration in which the mode is used.

  The single on mode is a mode in which one of the switching elements 51 to 54 is turned on and the remaining three switching elements are turned off. By the single on mode, it is possible to detect a short-circuit fault of the other switching element in the same arm as the switching element in the on state. For example, even when the switching element 52 is normal and the switching element 51 is turned on, the high potential line L1 and the low potential line L2 are not conducted, and the output current Iout does not flow through the current detection circuit 63. . On the other hand, when the switching element 51 is turned on when the switching element 52 is short-circuited, the high potential line L1 and the low potential line L2 are brought into conduction, and the output current Iout flows through the current detection circuit 63. The relationship between the presence / absence of the short-circuit failure of the switching element 52 and the output current Iout is obtained regardless of the presence / absence of the short-circuit failure on the lamp side.

  Therefore, when the current Iout exceeds the threshold value Ith, the control unit 8 determines that the other switching element in the same arm as the switching element in the on state is abnormal, and when the current Iout does not exceed the threshold value Ith It can be determined that the other switching element is normal.

  More specifically, regarding the first arm, in the single on mode in which the switching element 51 is turned on (hereinafter referred to as “SW51 on mode”), whether or not the switching element 52 is abnormal is determined as described above. In the single on mode in which the switching element 52 is turned on (hereinafter referred to as “SW52 on mode”), it is determined whether or not the switching element 51 is abnormal. Similarly, regarding the second arm, in the single on mode in which the switching element 53 is turned on (hereinafter referred to as “SW53 on mode”), whether or not the switching element 54 is abnormal is determined, and the switching element 54 is turned on. In the single on mode (hereinafter referred to as “SW54 on mode”), it is determined whether or not the switching element 53 is abnormal.

  Also in this embodiment, the diagonal on mode is used together with the single on mode. Since the diagonal on mode is the same as that described in the first embodiment, the description thereof is omitted.

  As described above, the control unit 8 can identify and discriminate between the abnormality on the circuit side or the abnormality of each switching element and the abnormality on the lamp side by applying the single on mode and the diagonal on mode. Further, the output means 80 outputs a switching element determined to be abnormal or abnormal on the circuit side when an abnormality is determined in the single on mode, and when an abnormality is determined in the diagonal on mode, A lamp-side abnormality can be output.

FIG. 3 shows a flowchart of the control method of the present embodiment.
Steps S100, S101, and S115 are the same as the flow of the first embodiment. That is, in step S100, the output voltage Vout is set to the voltage V1, and the switching elements 51 to 54 are all turned off. In step S101, when the output current Iout exceeds the threshold value Ith (step S101, YES), the process proceeds to step S115. In other cases (step S101, NO), the process proceeds to step S120. . In step S115, an abnormality on the circuit side is specified, and a predetermined circuit operation is stopped. At this time, the output means 80 can output that an abnormality has occurred on the circuit side.

In step S120, the control unit 8 applies the SW51 on mode.
In step S121, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S121, when the output current Iout exceeds the threshold value Ith (step S121, YES), the control unit 8 determines that there is an abnormality in the switching element 52, and the process proceeds to step S122. On the other hand, when the output current Iout does not exceed the threshold value Ith in step S121 (step S121, NO), it is determined that the switching element 52 is normal, and the process proceeds to step S125.
In step S122, the control unit 8 specifies an abnormality of the switching element 52 in the same first arm as the switching element 51 in the on state, and stops the operation of the step-down converter 4, the full bridge circuit 5, or both. At this time, the output unit 80 may output that an abnormality has occurred on the circuit side or that an abnormality has occurred in the switching element 52.

In step S125, the control unit 8 applies the SW52 on mode.
In step S126, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S126, when the output current Iout exceeds the threshold value Ith (step S126, YES), the control unit 8 determines that there is an abnormality in the switching element 51, and the process proceeds to step S127. On the other hand, when the output current Iout does not exceed the threshold value Ith (step S126, NO), it is determined that the switching element 51 is normal, and the process proceeds to step S130.
In step S127, the control unit 8 identifies an abnormality of the switching element 51 in the same first arm as the switching element 52 in the on state, and stops the operation of the step-down converter 4, the full bridge circuit 5, or both. At this time, the output unit 80 may output that an abnormality has occurred on the circuit side or that an abnormality has occurred in the switching element 51.

In step S130, the control unit 8 applies the SW53 on mode.
In step S131, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S131, when the output current Iout exceeds the threshold value Ith (step S131, YES), the control unit 8 determines that there is an abnormality in the switching element 54, and the process proceeds to step S132. On the other hand, when the output current Iout does not exceed the threshold value Ith (step S131, NO), it is determined that the switching element 54 is normal, and the process proceeds to step S135.
In step S132, the control unit 8 identifies an abnormality of the switching element 54 in the same second arm as the switching element 53 in the on state, and stops the operation of the step-down converter 4, the full bridge circuit 5, or both. At this time, the output unit 80 may output that an abnormality has occurred on the circuit side or that an abnormality has occurred in the switching element 54.

In step S135, the control unit 8 applies the SW54 on mode.
In step S136, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S136, when the output current Iout exceeds the threshold Ith (step S136, YES), the control unit 8 determines that the switching element 53 is abnormal, and the process proceeds to step S137. On the other hand, when the output current Iout does not exceed the threshold value Ith (step S136, NO), it is determined that the switching element 53 is normal, and the process proceeds to step S140.
In step S137, the control unit 8 identifies an abnormality of the switching element 53 in the same second arm as the switching element 54 in the on state, and stops the operation of the step-down converter 4, the full bridge circuit 5, or both. At this time, the output unit 80 may output that an abnormality has occurred on the circuit side or that an abnormality has occurred in the switching element 53.

  Step S140 and subsequent steps are the same as the flow in the first embodiment. That is, the diagonal on mode is applied in step S140, the presence / absence of an abnormality on the circuit side is determined in step S141, and if there is an abnormality, a predetermined circuit operation is stopped and a necessary notification is output in step S145. If there is no abnormality, the starting operation of the discharge lamp 9 is performed in step S200, and the normal lighting operation of the discharge lamp 9 is performed in step S250.

  Note that the application order of the above-described SW51 on mode to SW54 on mode can be arbitrarily changed. Moreover, the process (S140 to S145) related to the diagonal on mode may be executed before the process (S120 to S137) related to the single on mode. In this case, when it is detected that there is an abnormality on the circuit side or the lamp side in the diagonal on mode (in a state where any one is not determined), and no abnormality is detected in all the single on modes, Thus, the abnormality on the lamp side is identified.

  As described above, according to the lighting device 1 of the present embodiment, the single on mode in which the single switching element is turned on when the discharge lamp 9 is not lit is applied. Then, when the detected output current Iout exceeds the threshold value Ith, an abnormality of the other switching element of the same arm as the switching element in the on state is determined. As a result, it is possible to distinguish the abnormality on the circuit side from the abnormality on the lamp side and to identify and identify the abnormal switching element. Therefore, in the lighting device 1, it is possible to more specifically identify the abnormality occurrence location without requiring an additional detection circuit component. Even when an abnormality occurs in the lighting device 10, the user continues to use the lighting device 10 by replacing only the failed member or component (for example, the switching element, the driver IC in the control unit, etc.). This is advantageous in maintenance management. In addition, it is possible to record which switching element has an abnormality, and to use the recorded information for subsequent quality control and the like.

<Third Embodiment>
The configuration in which the one-side on mode is applied in the first embodiment and the configuration in which the single-on mode is applied are shown in the second embodiment. The structure where is combined is shown.

  As described above, according to the one-side on mode, although an abnormality on the circuit side is specified by simple processing by applying the mode twice, the switching element in which the abnormality has occurred is not specified. On the other hand, according to the single on mode, although the switching element in which the abnormality has occurred is specified, it is necessary to apply the mode four times at the maximum in order to specify the switching element in which the abnormality has occurred. For example, referring to the flowchart of FIG. 3, the SW51 on mode (step S120), the SW52 on mode (step S125), and the SW53 on mode (step S130) before reaching step S137 where the abnormality of the switching element 53 is specified. And four times of application of the SW54 on mode (step S135) are required. Therefore, the present embodiment proposes a configuration that can identify the switching element in which an abnormality has occurred by applying the mode within three times.

FIG. 4 shows a flowchart of the control method of this embodiment.
Steps S100, S101, and S115 are the same as the flows of the first and second embodiments (see FIGS. 2 and 3), and thus description thereof is omitted. Steps S110, S111, S112, and S113 are the same as the flow of the first embodiment (see FIG. 2), and steps S121, S122, S126, and S127 are the same as the flow of the second embodiment (see FIG. 3). Since these are the same, detailed description thereof will be omitted as appropriate.

In step S110, the control unit 8 applies the high side on mode.
In step S111, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S111, when the output current Iout exceeds the threshold value Ith (step S111, YES), the process proceeds to step S117. At this point, it is specified that the abnormality is in the low-side switching element 52 or 54. On the other hand, when the output current Iout does not exceed the threshold value Ith in step S111 (step S111, NO), the process proceeds to step S112.

In step S117, the control unit 8 turns off the switching element 53 and shifts the processing from the high side on mode to the SW51 on mode.
In step S121, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S121, when the output current Iout exceeds the threshold value Ith (step S121, YES), the process proceeds to step S122. In other cases (step S121, NO), the process proceeds to step S133.

  In step S122, the control unit 8 identifies an abnormality of the switching element 52 in the same first arm as the switching element 51 in the on state, and stops the predetermined circuit operation. At this time, the output unit 80 may output that an abnormality has occurred in the switching element 52.

  On the other hand, in step S133, the control unit 8 determines the abnormality of the switching element 54 (since it is specified that the switching element 52 or 54 is abnormal in step S111 and the abnormality of the switching element 52 is denied in step S121). Specifically, the predetermined circuit operation is stopped. At this time, the output unit 80 may output that an abnormality has occurred in the switching element 54.

In step S112, the control unit 8 applies the low side on mode.
In step S113, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S113, when the output current Iout exceeds the threshold value Ith (step S113, YES), the process proceeds to step S119. At this point, it is specified that the abnormality is in the high-side switching element 51 or 53. On the other hand, when the output current Iout does not exceed the threshold value Ith in step S113 (step S113, NO), the process proceeds to step S140.

In step S119, the control unit 8 turns off the switching element 54 and shifts the processing from the low side on mode to the SW52 on mode.
In step S126, the control unit 8 determines whether or not the output current Iout exceeds the threshold value Ith. In step S126, when the output current Iout exceeds the threshold value Ith (step S126, YES), the process proceeds to step S127. In other cases (step S126, NO), the process proceeds to step S138.

  In step S127, the control unit 8 specifies an abnormality of the switching element 51 in the same first arm as the switching element 52 in the on state, and stops a predetermined circuit operation. At this time, the output unit 80 may output that an abnormality has occurred in the switching element 51.

  On the other hand, in step S138, the control unit 8 determines the abnormality of the switching element 53 (since it is specified that the switching element 51 or 53 is abnormal in step S113 and the abnormality of the switching element 51 is denied in step S126). Specifically, the predetermined circuit operation is stopped. At this time, the output unit 80 may output that an abnormality has occurred in the switching element 53.

  Steps S140 and after are the same as the flows in the first and second embodiments. That is, the diagonal on mode is applied in step S140, the presence / absence of an abnormality on the circuit side is determined in step S141, and if there is an abnormality, a predetermined circuit operation is stopped and a necessary notification is output in step S145. If there is no abnormality, the starting operation of the discharge lamp 9 is performed in step S200, and the normal lighting operation of the discharge lamp 9 is performed in step S250.

  As described above, to reach the determination of any abnormality of the switching elements 51 to 54, it is necessary to apply only three modes at the maximum. For example, according to the flowchart of FIG. 4, only the high side on mode (S110), the low side on mode (S112), and the SW52 on mode (S119) are required to reach the determination of the abnormality of the switching element 51 or 53. That is, it is possible to identify a switching element in which an abnormality has occurred by applying a small number of modes.

  The execution order of the processing (S110, S111, S117, S121, S122, and S133) associated with the high-side on mode and the processing associated with the low-side on mode (S112, S113, S119, S126, S127, and S138) are reversed. Also good. Further, as a modification of the flow in FIG. 4, in step S117, the switching element 51 is turned off and the SW53 mode is applied. If YES in step S121, step S133 is executed, and if NO, step S122 is executed. It may be. Similarly, in step S119, the switching element 52 may be turned off and the SW54 mode may be applied, and step S138 may be executed if YES in step S126, and step S127 may be executed if NO. In other words, when there is an abnormality in the full bridge circuit 5, after the high side on mode and the low side on mode specify whether the abnormality is on the high side or the low side, only the specified side is in the single on mode. Is applied to determine whether each switching element is abnormal.

  As described above, according to the present embodiment, when the one-side on mode is applied and an abnormality is determined, one of the two switching elements turned on in the one-side on mode is turned off. Single mode is executed. As a result, it is possible to distinguish abnormalities on the circuit side from abnormalities on the lamp side, identify abnormal switching elements, and discriminate them with less processing. Therefore, in the lighting device 1, it is possible to more specifically and quickly specify the abnormality occurrence location without requiring an additional detection circuit component. Even when an abnormality occurs in the lighting device 10, the user continues to use the lighting device 10 by replacing only the failed member or component (for example, the switching element, the driver IC in the control unit, etc.). This is advantageous for maintenance management. In addition, it is possible to record which switching element has an abnormality, and to use the recorded information for subsequent quality control and the like.

<Modification>
Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described configuration, and various modifications can be made as described below.

(1) Modifications regarding types of discharge lamps In each of the above embodiments, a high pressure discharge lamp has been exemplified as the discharge lamp 9, but the present invention is not limited to a low pressure discharge lamp (mercury lamp, fluorescent lamp, etc.), It can also be applied to lighting devices for various types of discharge lamps.

(2) Modification of Voltage V1 or Threshold Ith In each of the above embodiments, the output voltage Vout is the same voltage for all modes (high side on mode, low side on mode, single on mode, diagonal on mode). Although the configuration in which the output current Iout is set to V1 and the output current Iout is compared with the same threshold value Ith is shown, the voltage V1 or the threshold value Ith may be appropriately changed according to the mode to be applied.

(3) Modification of type of abnormality In each of the above-described embodiments, the explanation has been made assuming that a short circuit failure of the switching element of the full bridge circuit 5 is mainly assumed as an abnormality on the circuit side. Is not limited to this. For example, even if the switching element itself is normal, the state in which the switching element is short-circuited by foreign matter, moisture, etc. mixed in the lighting device 1 (particularly in the vicinity of the switching element) is also abnormal in the above embodiment. Detected as

(4) Modification of application timing of abnormality determination operation In each of the above-described embodiments, the abnormality determination operation is shown to be performed after the AC power supply AC is turned on and before the discharge lamp 9 is started. May be executed at other timings when the discharge lamp 9 is not lit. For example, on the condition that the control unit 8 includes a non-volatile memory and the capacity of the capacitor 34 is sufficiently large, the abnormality determination operation is immediately after the discharge lamp 9 is turned off (immediately after the AC power supply AC is shut off), and the control unit 8 It may be executed before the operation ends. Thereby, in preparation for the next lighting, the presence / absence of an abnormality is determined and the determination result is stored in the nonvolatile memory, and based on the stored information (particularly, information indicating normality) at the next lighting. The starting operation of the discharge lamp 9 can be started quickly. Also in this case, substantially the same control as in each of the above embodiments is performed for abnormality determination.

DESCRIPTION OF SYMBOLS 1 Discharge lamp lighting device 2 Rectifier circuit 3 Boost converter 4 Buck converter 5 Full bridge circuit 6 Detection circuit 8 Control part 9 Discharge lamp 10 Illumination devices 51-54 Switching element 63 Current detection circuit 80 Output means

Claims (9)

A discharge lamp lighting device,
A DC power supply circuit that outputs a DC output voltage;
A first arm comprising first to fourth switching elements, a first arm comprising a series circuit of the first and second switching elements, and a second arm comprising a series circuit of the third and fourth switching elements; Connected to the output side of the DC power supply circuit, the connection point of the first switching element and the second switching element, and the connection point of the third switching element and the fourth switching element via a discharge lamp A full bridge circuit to be connected;
A current detection circuit for detecting an output current of the DC power supply circuit;
When the discharge lamp is not lit, a single on mode is applied in which one of the first to fourth switching elements is turned on and the remaining switching elements are turned off, and the current detection circuit A controller that determines that there is an abnormality in the discharge lamp lighting device when the output current detected by the
Wherein the control unit is, when the output current exceeds the threshold, it release configured to determine that there is an abnormality in the other switching elements included in the same arm as the switching element, which is to the ON state lamp Lighting device. A discharge lamp lighting device,
A DC power supply circuit that outputs a DC output voltage;
A first arm comprising first to fourth switching elements, a first arm comprising a series circuit of the first and second switching elements, and a second arm comprising a series circuit of the third and fourth switching elements; Connected to the output side of the DC power supply circuit, the connection point of the first switching element and the second switching element, and the connection point of the third switching element and the fourth switching element via a discharge lamp A full bridge circuit to be connected;
A current detection circuit for detecting an output current of the DC power supply circuit;
When the discharge lamp is not lit, one of the first and third switching elements and the second and fourth switching elements are turned on and the other is turned off. And a control unit that can apply a one-side on mode and a single on mode in which one of the first to fourth switching elements is turned on and the remaining switching elements are turned off. In the one-side on mode, when the output current detected by the current detection circuit exceeds a threshold, the single on mode obtained by turning off one of the one set of the switching elements is further applied. When the output current detected by the current detection circuit exceeds a threshold value, the switching element that is turned on is The discharge lamp lighting apparatus having a configured controlled unit so as to determine that there is an abnormality in the other switching elements included in the same arm as. 3. The discharge lamp lighting device according to claim 1 , wherein an output voltage of the DC power supply circuit at the time of applying the one-side on mode or the single on mode is the DC power supply circuit at the time of starting or lighting the discharge lamp. The discharge lamp lighting device is lower than the output voltage. The discharge lamp lighting device according to any one of claims 1 or et 3, further discharge lamp lighting apparatus provided with an output means for outputting the result of determination by the control unit. Lighting device including the discharge lamp lighting device according to any one of claims 1 or et 4, and the discharge lamp. A DC power supply circuit that outputs a DC output voltage, a first arm composed of a series circuit of first and second switching elements, and a second arm composed of a series circuit of third and fourth switching elements are the DC A connection point between the first switching element and the second switching element, and a connection point between the third switching element and the fourth switching element are connected to each other via a discharge lamp. A control method of a discharge lamp lighting device having a full bridge circuit,
Applying a single on mode in which one of the first to fourth switching elements is turned on and the remaining switching elements are turned off when the discharge lamp is not lit;
Detecting an output current of the DC power supply circuit;
Determining that there is an abnormality in the discharge lamp lighting device when the detected output current exceeds a threshold ,
In the step of the determination, the output current when it exceeds the threshold, that the there is an abnormality in the other switching elements included in the same arm as the switching element is turned on is determined, the control method. A DC power supply circuit that outputs a DC output voltage, a first arm composed of a series circuit of first and second switching elements, and a second arm composed of a series circuit of third and fourth switching elements are the DC A connection point between the first switching element and the second switching element, and a connection point between the third switching element and the fourth switching element are connected to each other via a discharge lamp. A control method of a discharge lamp lighting device having a full bridge circuit,
When the discharge lamp is not lit, one of the first and third switching elements and the second and fourth switching elements are turned on and the other is turned off. Applying one side on mode to
Detecting an output current of the DC power supply circuit;
When the detected output current exceeds a threshold, applying the single on-mode obtained from the one-side on mode with one of the switching elements in the one set being in an off state; and
Detecting an output current of the DC power supply circuit;
And a step of determining that there is an abnormality in the other switching element included in the same arm as the switching element in the on state when the detected output current exceeds a threshold value. 8. The control method according to claim 6 or 7 , wherein an output voltage of the DC power supply circuit when the one-side on mode or the single on mode is applied is an output of the DC power supply circuit when the discharge lamp is started or turned on. Control method lower than voltage. The control method according to claim 6 , further comprising a step of outputting a result of the determination.

Images