JP2008251327A - Discharge lamp lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption in a controlled power supply circuit while securing current which is necessary for the operation of a microcomputer controlling the operation of an inverter circuit. <P>SOLUTION: The first control power supply circuit 160 generates a first control power supply voltage from an undulating voltage generated by a rectifier circuit 110. The second control power supply circuit 170 generates a second control power supply voltage from a rectangular-wave voltage (alternating voltage) output from the inverter circuit 130. An available clock generating circuit 152 generates an operation clock with a high frequency (first frequency), when the inverter circuit 130 generates the rectangular-wave voltage, or generates an operation clock with a low frequency (second frequency), when the inverter circuit 130 generates no rectangular-wave voltage, to supply it to the microcomputer 151. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

In an inverter type discharge lamp lighting device, the oscillation of an inverter circuit is controlled using a microcomputer.
In order to operate the microcomputer, for example, a constant voltage of DC 5V is required, and the discharge lamp lighting device has a control power supply circuit for generating it.
JP-A-4-269500 Japanese Patent Laid-Open No. 7-57887

While efforts are being made to reduce the power consumption of the discharge lamp lighting device, it is desirable to reduce the power consumption in the control power circuit as much as possible.
On the other hand, the current required for the microcomputer to operate tends to increase due to the higher functionality of the microcomputer and the adoption of flash memory.
The present invention has been made, for example, to solve the above-described problems, and has an object to secure a current necessary for operating a microcomputer while suppressing power consumption in a control power supply circuit. .

The discharge lamp lighting device according to this invention is
A rectifier circuit that rectifies an AC voltage to generate a pulsating voltage;
A DC power supply circuit that generates a DC voltage from the pulsating voltage generated by the rectifier circuit;
An inverter circuit for generating an AC voltage applied to the discharge lamp from the DC voltage generated by the DC power supply circuit;
A microcomputer for controlling the operation of the inverter circuit;
A first control power supply circuit that generates a first control power supply voltage from any one of the AC voltage and the pulsating voltage generated by the rectifier circuit, and supplies the first control power supply voltage to the microcomputer;
A second control power supply circuit that generates a second control power supply voltage from the AC voltage generated by the inverter circuit and supplies the second control power supply voltage to the microcomputer;
When the inverter circuit generates an AC voltage, an operation clock having a first frequency is generated. When the inverter circuit does not generate an AC voltage, a second frequency lower than the first frequency is generated. And an operation clock generation circuit that generates an operation clock and supplies the operation clock to the microcomputer.

  According to the discharge lamp lighting device according to this embodiment, when the second control power supply circuit can generate the control power supply voltage by the operation of the inverter circuit, the operation clock of the microcomputer is set to a high frequency and the inverter circuit is stopped. When the second control power supply circuit cannot generate the control power supply voltage, the microcomputer operating clock is set to a low frequency. Therefore, the first control power supply circuit requires a current required when the microcomputer operates at a low frequency. If it has the ability to supply. For this reason, the first control power circuit can be reduced in size, reduced in power consumption, and reduced in cost.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

  FIG. 1 is a circuit configuration diagram showing a circuit configuration of a discharge lamp lighting device 100 which is a main part of a lighting fixture 800 in this embodiment.

The discharge lamp lighting device 100 receives an AC voltage from a commercial power source AC or the like, and generates an AC voltage to be applied to the discharge lamp LA.
The discharge lamp lighting device 100 includes a rectifier circuit 110, a DC power supply circuit 120, an inverter circuit 130, a choke coil L41, a starting capacitor C42, a coupling capacitor C43, a one-chip microcomputer 150, a first control power supply circuit 160, and a second control power supply. A circuit 170 and a constant voltage circuit 180 are included.

The rectifier circuit 110 receives an AC voltage from a commercial power source AC or the like, and rectifies the input AC voltage to generate a pulsating voltage.
The rectifier circuit 110 is configured by, for example, a diode bridge DB.

The DC power supply circuit 120 receives the pulsating voltage generated by the rectifier circuit 110 and boosts or steps down to generate a stable DC voltage.
The DC power supply circuit 120 is constituted by, for example, a boost chopper circuit including a power supply control circuit 121 (control IC), a choke coil L22, an FET Q23, a diode D24, and a capacitor C25.

The inverter circuit 130 receives the DC voltage generated by the DC power supply circuit 120 and generates a rectangular wave voltage (AC voltage) to be applied to a load circuit including the choke coil L41, the starting capacitor C42, the discharge lamp LA, and the coupling capacitor C43. .
The inverter circuit 130 includes an FET Q31, an FET Q32, and a drive circuit 133. The drive circuit 133 alternately turns on and off the FET Q31 and the FET Q32 to generate a rectangular wave voltage.

The one-chip microcomputer 150 controls the operation of the inverter circuit 130 (for example, preheating / starting / lighting / extinguishing the discharge lamp LA, etc.) by outputting a control signal for controlling the drive circuit 133.
The one-chip microcomputer 150 includes a microcomputer 151 and an operation clock generation circuit 152.
The microcomputer 151 is the heart of the one-chip microcomputer 150, and outputs a control signal for controlling the drive circuit 133 by executing a program stored in a memory (not shown).

The operation clock generation circuit 152 generates an operation clock for operating the microcomputer 151.
The frequency of the operation clock generated by the operation clock generation circuit 152 can be changed by an instruction from the microcomputer 151.
If the frequency of the operation clock is high, the microcomputer 151 can perform processing at that high speed, but the power consumption of the microcomputer 151 increases.
If the frequency of the operation clock is low, the processing of the microcomputer 151 is delayed, but the power consumption of the microcomputer 151 can be suppressed instead.

The first control power circuit 160 receives the pulsating voltage generated by the rectifier circuit 110 and generates a first control power voltage from the input pulsating voltage.
The first control power supply voltage generated by the first control power supply circuit 160 is supplied to the one-chip microcomputer 150 via the constant voltage circuit 180 and becomes an operation power supply for the microcomputer 151.
The first control power circuit 160 includes, for example, a diode D61 and a resistor R62.
The function of the diode D61 prevents a current from flowing backward from the output side of the first control power supply circuit 160. In addition, the voltage level of the first control power supply circuit 160 output from the first control power supply circuit 160 is lowered to a level that can be supplied to the one-chip microcomputer 150 due to the voltage drop in the resistor R62.
The first control power supply circuit 160 may be configured to generate the first control power supply voltage from the AC voltage input from the rectifier circuit 110 instead of the pulsating voltage generated by the rectifier circuit 110.

The constant voltage circuit 180 sets the first control power supply voltage generated by the first control power supply circuit 160 to a constant voltage and supplies it to the one-chip microcomputer 150. .
The constant voltage circuit 180 includes, for example, a Zener diode Z81 (constant voltage element) and a capacitor C82. When the diode D61 of the first control power circuit 160 is on, the current passing through the first control power circuit 160 charges the capacitor C82 to the breakdown voltage of the Zener diode Z81.

  The first control power supply circuit 160 and the constant voltage circuit 180 have a general regulator circuit configuration, and may have other configurations.

The second control power supply circuit 170 receives the rectangular wave voltage (AC voltage) generated by the inverter circuit 130 and generates a second control power supply voltage from the input rectangular wave voltage.
Similar to the first control power supply voltage generated by the first control power supply circuit 160, the second control power supply voltage generated by the second control power supply circuit 170 is supplied to the one-chip microcomputer 150 via the constant voltage circuit 180. Supplied and serves as an operating power source for the microcomputer 151.
The second control power supply circuit 170 is, for example, a snubber circuit, and includes a capacitor C71, a diode D72, and a diode D73.
When the rectangular wave voltage generated by the inverter circuit 130 rises, a current for charging the capacitor C71 flows. This current becomes a current for charging the capacitor C82 of the constant voltage circuit 180 by the action of the diode D72 and the diode D73. When the rectangular wave voltage generated by the inverter circuit 130 falls, a current that discharges the capacitor C71 flows. However, since this current is supplied from the diode D72, the capacitor C82 of the constant voltage circuit 180 is not discharged.

  Although the output of the first control power supply circuit 160 and the output of the second control power supply circuit 170 are simply connected, both output currents are controlled by the constant voltage circuit 180 due to the functions of the diode D61 and the diode D73. And charge capacitor C82. Therefore, even when only one of the first control power supply circuit 160 and the second control power supply circuit 170 generates the control power supply voltage, the operation power can be supplied to the one-chip microcomputer 150.

  Immediately after the power supply of the discharge lamp lighting device 100 is turned on, the microcomputer 151 does not operate, so that a control signal for controlling the drive circuit 133 is not output. Therefore, the inverter circuit 130 does not operate and a rectangular wave voltage is not generated. Therefore, the second control power supply circuit 170 does not generate a control power supply voltage.

On the other hand, the first control power circuit 160 generates a control power voltage from the pulsating voltage generated by the rectifier circuit 110 regardless of whether the microcomputer 151 is operating.
As a result, operating power is supplied to the microcomputer 151, and the microcomputer 151 starts operating.

When the microcomputer 151 starts to operate and starts outputting a control signal for controlling the drive circuit 133 and the inverter circuit 130 starts to operate, the second control power supply circuit 170 starts to generate the control power supply voltage.
As a result, the microcomputer 151 receives the operation power from both the first control power circuit 160 and the second control power circuit 170 and continues the operation.

  Next, the operation will be described.

  FIG. 2 is a flowchart showing a flow of a lighting start process in which the discharge lamp lighting device 100 according to this embodiment starts lighting the discharge lamp LA.

  In the power-on process S11, the power is turned on, and an AC voltage from the commercial power source AC or the like is supplied to the discharge lamp lighting device 100.

  In the first control power supply step S <b> 12, the first control power supply circuit 160 supplies operating power to the one-chip microcomputer 150.

  In the low frequency clock generation step S13, the operation clock generation circuit 152 generates an operation clock. The clock frequency at this time is a low frequency (second frequency), and the operation of the microcomputer 151 is slow, but power consumption is suppressed.

In the initialization step S14, the microcomputer 151 starts operation with the operation power from the first control power supply circuit 160 and the operation clock from the operation clock generation circuit 152, and performs initialization processing by power-on reset. To do.
During the initialization process, the frequency of the operation clock generated by the operation clock generation circuit 152 may be reset to a low frequency to ensure the operation in the low speed mode.

After the initialization process, in the inverter operation step S15, the microcomputer 151 starts the operation of the inverter circuit 130. That is, the microcomputer 151 generates and outputs a control signal for operating the inverter circuit 130.
Thereby, the inverter circuit 130 starts operation and outputs a rectangular wave voltage.

  In the second control power supply step S <b> 16, the second control power supply circuit 170 generates a second control power supply voltage and supplies operation power to the one-chip microcomputer 150.

In the high frequency clock generation step S17, the operation clock generation circuit 152 increases the frequency of the operation clock to be generated, and generates an operation clock having a high frequency (first frequency).
For example, after the microcomputer 151 outputs a control signal for operating the inverter circuit 130, the operation clock generation circuit 152 is instructed to change the operation clock, and the operation clock generation circuit 152 increases the frequency of the operation clock.
Thereby, the microcomputer 151 is in a high-speed mode with high power consumption but fast operation.

  FIG. 3 is a timing chart showing the operation of the discharge lamp lighting device 100 in this embodiment.

When an AC voltage is supplied from the commercial power supply AC or the like by turning on the power, the first control power supply circuit 160 generates a first control power supply voltage.
When the first control power supply voltage reaches a predetermined operable voltage, the operation clock generation circuit 152 generates an operation clock (low frequency), and the microcomputer 151 starts operation.
The microcomputer 151 outputs a control signal for operating the inverter circuit 130 after the power-on reset and initialization processing, and the inverter circuit 130 operates. As a result, the second control power supply circuit 170 generates the second control power supply voltage.
The microcomputer 151 changes the clock frequency, and the operation clock generation circuit 152 generates an operation clock (high frequency).

As a result, the power consumption of the microcomputer 151 increases, so that the operating current increases.
The operating current of the microcomputer 151 is supplied from the first control power circuit 160 and the second control power circuit 170.
The dotted line indicates the total current supply capability of the first control power supply circuit 160 and the second control power supply circuit 170.
The first control power supply circuit 160 has an ability to supply a current required when the microcomputer 151 operates at a low speed, but does not have an ability to supply a necessary current when the microcomputer 151 operates at a high speed alone. Together with the supply capability of the power supply circuit 170, a current necessary for high-speed operation of the microcomputer 151 is supplied.
Since the microcomputer 151 shifts to a high-speed operation after the second control power supply circuit 170 starts operation, a necessary current is always secured.

  The reason why the current supply capability is suppressed to a low level without allowing the first control power supply circuit 160 to supply a necessary current during high-speed operation alone is as follows.

By reducing the current supply capability of the first control power supply circuit 160, the components can be reduced in size.
The first control power supply circuit 160 adjusts the difference between the pulsating voltage and the control power supply voltage due to the voltage drop across the resistor R62. Therefore, increasing the current supply capability of the first control power supply circuit 160 increases the power consumption in the resistor R62. By reducing the current supply capability of the first control power supply circuit 160, the power consumption can be reduced.
The power supply voltage of the commercial power supply AC connected to the discharge lamp lighting device 100 varies from 100 V to 254 V, and the discharge lamp lighting device 100 operates with any power supply voltage (so-called power supply voltage free). ) Is often designed.
When the first control power supply circuit 160 is designed so that a necessary current can be secured when the power supply voltage of the commercial power supply AC is the minimum value (for example, 100 V) of the design range, wasteful power consumption occurs when the power supply voltage is high. Becomes larger.
Further, in recent years, a flash microcomputer may be used as the one-chip microcomputer 150. Since the flash microcomputer is capable of writing operation, it is superior to the conventional mask ROM microcomputer in terms of manufacturing process, production management, and functions.
On the other hand, the flash microcomputer consumes more power than the mask ROM microcomputer and requires more current. Therefore, if a sufficient current is not secured, there is a possibility that a problem such as a microcomputer not operating at all due to a current shortage may occur.

For the reasons described above, the first control power supply circuit 160 alone is not allowed to supply a current necessary for high-speed operation, and only a current necessary for low-speed operation is ensured.
Since the initialization process and the like are sufficient in the low-speed mode, the microcomputer 151 operates in the low-speed mode immediately after the operation starts. Thereafter, after the second control power supply circuit 170 starts operating and secures a current necessary for high-speed operation, the microcomputer 151 shifts to the high-speed mode and obtains a necessary processing speed.

  According to the discharge lamp lighting device 100 in this embodiment, when the second control power supply circuit 170 can generate the control power supply voltage by the operation of the inverter circuit 130, the operation clock of the microcomputer 151 is set to a high frequency, and the inverter circuit 130 When the second control power supply circuit 170 cannot generate the control power supply voltage, the operation clock of the microcomputer 151 is set to a low frequency. Therefore, the first control power supply circuit 160 is connected to the microcomputer 151 with a low frequency. It suffices if it has the ability to supply the necessary current when operating on. Therefore, the first control power supply circuit 160 can be reduced in size, reduced in power consumption, and reduced in cost.

  According to the discharge lamp lighting device 100 in this embodiment, after the microcomputer 151 starts the operation of the inverter circuit 130 and the second control power supply circuit 170 starts to generate the control power supply voltage, the operation clock generation circuit Since the frequency of the operation clock generated by 152 is switched to a high frequency, the current necessary for the operation of the microcomputer 151 can be always secured.

  Note that the microcomputer 151 may start the operation of the inverter circuit 130, wait for a predetermined time, and then switch the frequency of the operation clock generated by the operation clock generation circuit 152 to a high frequency. By doing so, even when the startup of the second control power supply circuit 170 or the like takes time, it is possible to reliably secure a current necessary for the operation of the microcomputer 151.

  When the lighting fixture 800 includes the discharge lamp lighting device 100 according to this embodiment, the lighting fixture 800 as a whole can be reduced in size, power consumption, and cost.

  In addition, a flash microcomputer having a large current required for operation can be used as the microcomputer 151, which is advantageous in the manufacturing process.

  Note that not only the power supply of the microcomputer 151 but also the power supply of the power supply control circuit 121 and the drive circuit 133 may be obtained from the second control power supply circuit 170.

Embodiment 2. FIG.
The second embodiment will be described with reference to FIGS.

FIG. 4 is a circuit configuration diagram showing a circuit configuration of the discharge lamp lighting device 100 which is a main part of the lighting fixture 800 in this embodiment.
Note that portions common to the lighting fixture 800 described in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted here.

The first control power circuit 160 further includes a switching element Q63.
The switching element Q63 is turned on / off by an instruction from the microcomputer 151. The switching element Q63 is turned on when the microcomputer 151 is stopped, and turned off when the instruction signal from the microcomputer 151 is input.

When the switching element Q63 is on, the first control power circuit 160 generates a first control power voltage from the pulsating voltage generated by the rectifier circuit 110.
When the switching element Q63 is off, the first control power supply circuit 160 does not generate the first control power supply voltage.

FIG. 5 is a flowchart showing a flow of a lighting start process in which the discharge lamp lighting device 100 according to this embodiment starts lighting the discharge lamp LA.
In addition, the same code | symbol is attached | subjected to the process which is common in the lighting start process demonstrated in Embodiment 1, and description is abbreviate | omitted here.

In the first control power supply stop step S <b> 18, the first control power supply circuit 160 stops generating the first control power supply voltage and stops supplying operating power to the one-chip microcomputer 150.
For example, when the microcomputer 151 outputs an instruction signal for turning off the switching element Q63 and the switching element Q63 is turned off, the first control power supply circuit 160 stops generating the first control power supply voltage.

Note that the switching element Q63 may be configured to detect an output voltage of the inverter circuit 130 instead of an instruction from the microcomputer 151 and to turn off.
The first control power supply circuit 160 may be stopped before the clock frequency is changed as long as the inverter circuit 130 is activated.

  FIG. 6 is a timing chart showing the operation of the discharge lamp lighting device 100 in this embodiment.

  The switching element Q63 of the first control power supply circuit 160 is turned off by the signal output from the microcomputer 151, and the first control power supply circuit 160 stops generating the control power supply voltage. As a result, only the second control power supply circuit 170 supplies operating power to the microcomputer 151, so that the current that can be supplied is reduced.

  The second control power supply circuit 170 in this embodiment is capable of supplying the necessary current when the microcomputer 151 operates at high speed alone. Therefore, even if the first control power circuit 160 is stopped after the inverter circuit 130 is operated, a current necessary for the operation of the microcomputer 151 can be secured.

  When the switching element Q63 is on, current continues to flow through the first control power supply circuit 160, and thus there is power consumption in the resistor R62. By turning off the switching element Q63, useless power consumption can be reduced.

  The second control power supply circuit 170 adjusts the output control power supply voltage based on the voltage division ratio between the capacitor C71 and the capacitor C82, not the voltage drop due to the resistance. Therefore, even if the current supply capability of the second control power supply circuit 170 is increased, unlike the first control power supply circuit 160, useless power consumption does not occur.

Further, the voltage value of the rectangular wave voltage output from the inverter circuit 130 is determined by the DC voltage output from the DC power supply circuit 120, and is therefore constant regardless of the power supply voltage from the commercial power supply AC or the like.
Therefore, even when the discharge lamp lighting device 100 is free of the power supply voltage, the power consumption in the second control power supply circuit 170 is not changed, and unnecessary power is not consumed.

On the other hand, the first control power supply circuit 160 is designed in accordance with the case where the power supply voltage of the commercial power supply AC is the minimum value in the design range. Consumes a lot of power.
However, since the switching element Q63 is turned off after the operation of the inverter circuit 130, the first control power supply circuit 160 does not consume power and can suppress wasteful power consumption.

  According to the discharge lamp lighting device 100 and the lighting fixture 800 in this embodiment, when the second control power supply circuit 170 generates the control power supply voltage, the first control power supply circuit 160 reduces the control power supply voltage. Since it does not generate | occur | produce, there exists an effect that wasteful power consumption can be suppressed.

Embodiment 3 FIG.
The third embodiment will be described with reference to FIGS.

FIG. 7 is a circuit configuration diagram showing a circuit configuration of the discharge lamp lighting device 100 which is a main part of the lighting fixture 800 in this embodiment.
Note that portions common to the lighting fixture 800 described in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted here.

The discharge lamp lighting device 100 further includes a voltage detection circuit 190.
The voltage detection circuit 190 detects the rectangular wave voltage output from the inverter circuit 130.
The voltage detection circuit 190 includes, for example, a resistor R91 and a capacitor C92, the capacitor C92 is charged with a part of the current charging the capacitor C71, and the microcomputer 151 measures the voltage charged in the capacitor C92. , Detect square wave voltage.

FIG. 8 is a flowchart showing a flow of a lighting start process in which the discharge lamp lighting device 100 according to this embodiment starts lighting the discharge lamp LA.
In addition, the same code | symbol is attached | subjected to the process which is common in the lighting start process demonstrated in Embodiment 1, and description is abbreviate | omitted here.

  In the standby step S21, the microcomputer 151 determines whether the rectangular wave voltage generated by the inverter circuit 130 is higher than a predetermined voltage based on the voltage detected by the voltage detection circuit 190, and the rectangular wave voltage is higher than the predetermined voltage. Wait until it gets high.

  Thereafter, after the rectangular wave voltage becomes higher than a predetermined voltage, the frequency of the operation clock is switched to a high frequency.

In the first embodiment, when the microcomputer 151 outputs a control signal for operating the inverter circuit 130, it is determined that the inverter circuit 130 has generated a rectangular wave voltage, and the operation clock frequency is increased.
However, the inverter circuit 130 may not operate due to a failure or the like. In addition, there is a variation in the time required to start the operation due to variations in components.
In this embodiment, when the rectangular wave voltage generated by the inverter circuit 130 is detected and becomes higher than a predetermined voltage, the operation clock frequency is increased, so that the current necessary for high-speed operation of the microcomputer 151 is ensured. It can be secured.

  According to the discharge lamp lighting device 100 and the lighting fixture 800 in this embodiment, after the voltage detection circuit 190 detects the AC voltage generated by the inverter circuit 130, the frequency of the operation clock generated by the operation clock generation circuit 152 is set. Since the height is increased, the current required by the microcomputer 151 can be reliably obtained.

  Note that, as described in Embodiment 2, the first control power supply circuit 160 may be stopped to reduce power consumption. In that case, after confirming that the rectangular wave voltage generated by the inverter circuit 130 becomes higher than a predetermined voltage, the first control power supply circuit 160 is stopped.

Embodiment 4 FIG.
The fourth embodiment will be described with reference to FIGS.

FIG. 9 is a circuit configuration diagram showing a circuit configuration of the discharge lamp lighting device 100 which is a main part of the lighting fixture 800 in this embodiment.
In addition, about the part which is common in the lighting fixture 800 demonstrated in Embodiment 1- Embodiment 3, the same code | symbol is attached | subjected and description is abbreviate | omitted here.

The discharge lamp lighting device 100 further includes an abnormality detection circuit 210.
The abnormality detection circuit 210 detects an abnormality of the discharge lamp LA such as the end of life by detecting a voltage applied to the discharge lamp LA.
The abnormality detection circuit 210 includes, for example, a resistor R11 and a resistor R12. The microcomputer 151 measures a voltage divided by the resistor R11 and the resistor R12, thereby detecting an abnormality in the discharge lamp LA.
Note that the abnormality detection circuit 210 may be a circuit that detects other abnormality that should stop the inverter circuit 130 such as disconnection of a discharge lamp.

  FIG. 10 is a flowchart showing the flow of a lighting stop process for stopping the lighting of the discharge lamp LA when the abnormality detection circuit 210 in this embodiment detects an abnormality of the discharge lamp LA.

  In the abnormality detection step S31, the abnormality detection circuit 210 detects an abnormality in the discharge lamp LA. 210 outputs an abnormality detection signal indicating that an abnormality of the discharge lamp LA has been detected, for example.

In the clock switching step S32, the frequency of the operation clock generated by the operation clock generation circuit 152 is switched to a low frequency to generate a low frequency operation clock.
For example, after the microcomputer 151 inputs the abnormality detection signal from the abnormality detection circuit 210, the microcomputer 151 outputs a signal instructing the operation clock generation circuit 152 to switch the operation clock, and the operation clock generation circuit 152 outputs the operation clock. Reduce the frequency.

In the inverter stop step S33, the microcomputer 151 generates and outputs a control signal for stopping the operation of the inverter circuit 130, and the inverter circuit 130 stops the operation.
As a result, the discharge lamp LA is turned off.

If the operation of the inverter circuit 130 is stopped to turn off the discharge lamp LA due to the abnormality detection, the second control power supply circuit 170 cannot generate the control power supply voltage.
Therefore, before the operation of the inverter circuit 130 is stopped, the microcomputer 151 is switched to the low speed mode to reduce the necessary current.
Thereby, even when the discharge lamp LA is turned off due to abnormality detection, the current required by the microcomputer 151 can be secured.

  According to the discharge lamp lighting device 100 and the lighting fixture 800 in this embodiment, when the discharge lamp LA is extinguished, the frequency of the operation clock generated by the operation clock generation circuit 152 is switched to a low frequency, and the microcomputer 151 Since the inverter circuit 130 is stopped after reducing the current necessary for the operation, the current necessary for the operation of the microcomputer 151 can be always secured.

  According to the discharge lamp lighting device 100 and the lighting fixture 800 in this embodiment, the frequency of the operation clock generated by the operation clock generation circuit 152 when the discharge lamp LA is extinguished because the abnormality detection circuit 210 detects an abnormality. Is switched to a low frequency to reduce the current required for the operation of the microcomputer 151 and then the inverter circuit 130 is stopped. Therefore, even if an abnormality occurs in the discharge lamp LA, the current required for the operation of the microcomputer 151 There is an effect that can be secured.

  Note that, as described in Embodiment 2, after the operation of the inverter circuit 130 is started, the first control power supply circuit 160 may be stopped to reduce power consumption. In that case, before the inverter circuit 130 is stopped, the operation of the first control power supply circuit 160 is restarted to secure the control power supply voltage, and then the inverter circuit 130 is stopped.

Embodiment 5. FIG.
The fifth embodiment will be described with reference to FIG.

FIG. 11 is a circuit configuration diagram showing a circuit configuration of the discharge lamp lighting device 100 which is a main part of the lighting fixture 800 in this embodiment.
Note that portions common to the lighting fixture 800 described in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted here.

The discharge lamp lighting device 100 inputs a command signal.
The command signal is a signal for instructing lighting / extinguishing / dimming of the discharge lamp LA.
For example, the command signal is a rectangular wave signal having a predetermined frequency, and is a PWM (Pulse Width Modulated) signal (dimming signal) that indicates the dimming level by the duty ratio of the pulse. Alternatively, the command signal may be a signal instructing only lighting / extinguishing of the discharge lamp LA.
The command signal is generated and output by, for example, a human sensor or a remote control receiver installed outside the discharge lamp lighting device 100. Note that the discharge lamp lighting device 100 may incorporate a remote control receiver or the like to generate a command signal.

The microcomputer 151 inputs a command signal.
The microcomputer 151 decodes the input command signal and controls the lighting state of the discharge lamp LA according to the instruction of the command signal.
For example, when the command signal is the above-described PWM signal, the duty ratio of the input command signal is measured, and the instruction content of the command signal is decoded. For example, if the on-duty is 5%, the discharge lamp LA is lit with a dimming degree of 100%, and the dimming degree of the discharge lamp LA decreases as the on-duty increases, and if the on-duty is 90%, the discharge lamp LA With a dimming degree of 25%. Further, when the on-duty of the command signal is 100% (that is, direct current), the discharge lamp LA is turned off.

The microcomputer 151 generates and outputs a control signal for controlling the inverter circuit 130 according to the decoded instruction content. For example, when the on-duty of the command signal is 5%, the microcomputer 151 generates a control signal for operating the inverter circuit 130 at 100 kHz in order to light the discharge lamp LA with a dimming degree of 100%. When the on-duty of the command signal is 90%, the microcomputer 151 generates a control signal for operating the inverter circuit 130 at 50 kHz in order to light the discharge lamp LA with a dimming degree of 25%. When the command signal is DC, the microcomputer 151 generates a control signal for stopping the inverter circuit 130 in order to extinguish the discharge lamp LA.
In addition, the numerical value described here is an example, Comprising: It does not restrict to this. Further, the command signal is not limited to the PWM signal, and may represent the instruction content by other methods.

When the instruction signal instructs the extinction of the discharge lamp LA, the microcomputer 151 does not stop the inverter circuit 130 immediately, but before that, the operation clock generation circuit 152 sets the operation clock frequency to a low frequency. A signal instructing switching is output.
The operation clock generation circuit 152 receives this signal and switches the frequency of the generated operation clock to a low frequency. As a result, the microcomputer 151 enters the low speed mode, and the required maximum current is reduced.

Thereafter, the microcomputer 151 outputs a control signal for stopping the operation of the inverter circuit 130. The inverter circuit 130 stops operating, and the discharge lamp LA is turned off.
As a result, the second control power supply circuit 170 does not generate the control power supply voltage, and the microcomputer 151 receives the control power supply voltage only from the first control power supply circuit 160. Since the microcomputer 151 is in the low speed mode and the required maximum current is small, it falls within the range of the current supply capability of the first control power supply circuit 160.

  When it takes time to change the operation clock, the microcomputer 151 outputs a signal for instructing the operation clock generation circuit 152 to change the operation clock, waits for a predetermined time, and then operates the inverter circuit 130. A control signal for stopping the control may be output. However, the delay time is preferably within 300 milliseconds at the maximum. This is because, for example, if the time taken to turn off the discharge lamp LA is within 300 milliseconds, the user who has instructed to turn it off by remote control operation does not feel that the reaction is slow.

  According to the discharge lamp lighting device 100 and the lighting fixture 800 in this embodiment, when the discharge lamp LA is turned off by an instruction of the command signal, the frequency of the operation clock generated by the operation clock generation circuit 152 is switched to a low frequency. Since the inverter circuit 130 is stopped after reducing the current necessary for the operation of the microcomputer 151, the current necessary for the operation of the microcomputer 151 can be ensured even when the microcomputer 151 is turned off by the command signal. Play.

  Note that, as described in Embodiment 2, after the operation of the inverter circuit 130 is started, the first control power supply circuit 160 may be stopped to reduce power consumption. In that case, before the inverter circuit 130 is stopped, the operation of the first control power supply circuit 160 is restarted to secure the control power supply voltage, and then the inverter circuit 130 is stopped.

FIG. 3 is a circuit configuration diagram showing a circuit configuration of a discharge lamp lighting device 100 that is a main part of the lighting fixture 800 in the first embodiment. The flowchart figure which shows the flow of the lighting start process in which the discharge lamp lighting device 100 in Embodiment 1 starts lighting of the discharge lamp LA. FIG. 3 is a timing chart showing the operation of the discharge lamp lighting device 100 in the first embodiment. The circuit block diagram which shows the circuit structure of the discharge lamp lighting device 100 which is the principal part of the lighting fixture 800 in Embodiment 2. FIG. The flowchart figure which shows the flow of the lighting start process in which the discharge lamp lighting device 100 in Embodiment 2 starts lighting of the discharge lamp LA. FIG. 6 is a timing chart illustrating an operation of the discharge lamp lighting device 100 according to the second embodiment. FIG. 6 is a circuit configuration diagram showing a circuit configuration of a discharge lamp lighting device 100 that is a main part of a lighting fixture 800 in a third embodiment. The flowchart figure which shows the flow of the lighting start process in which the discharge lamp lighting device 100 in Embodiment 3 starts lighting of the discharge lamp LA. FIG. 6 is a circuit configuration diagram showing a circuit configuration of a discharge lamp lighting device 100 that is a main part of a lighting fixture 800 in a fourth embodiment. The flowchart figure which shows the flow of the lighting stop process which stops lighting of the discharge lamp LA, when the abnormality detection circuit 210 in Embodiment 4 detects the abnormality of the discharge lamp LA. FIG. 6 is a circuit configuration diagram showing a circuit configuration of a discharge lamp lighting device 100 that is a main part of a lighting fixture 800 in a fifth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Discharge lamp lighting device, 110 Rectifier circuit, 120 DC power supply circuit, 121 Power supply control circuit, 130 Inverter circuit, 133 Drive circuit, 150 One-chip microcomputer, 151 Microcomputer, 152 Operation clock generation circuit, 160 1st control power supply circuit , 170 Second control power supply circuit, 180 constant voltage circuit, 190 voltage detection circuit, 210 abnormality detection circuit, 800 lighting fixture, AC commercial power supply, C25, C71, C82, C92 capacitor, C42 starting capacitor, C43 coupling capacitor, D24 , D61, D72, D73 Diode, DB diode bridge, LA discharge lamp, L22, L41 choke coil, Q23, Q31, Q32 FET, Q63 switching element, R62, R91, R11, R12 resistor, Z81 E zener diode.

Claims (7)

A rectifier circuit that rectifies an AC voltage to generate a pulsating voltage;
A DC power supply circuit that generates a DC voltage from the pulsating voltage generated by the rectifier circuit;
An inverter circuit that generates an AC voltage applied to the discharge lamp from a DC voltage generated by the DC power supply circuit;
A microcomputer for controlling the operation of the inverter circuit;
A first control power supply circuit that generates a first control power supply voltage from any of the AC voltage and the pulsating voltage generated by the rectifier circuit, and supplies the first control power supply voltage to the microcomputer;
A second control power supply circuit that generates a second control power supply voltage from the AC voltage generated by the inverter circuit and supplies the second control power supply voltage to the microcomputer;
When the inverter circuit generates an AC voltage, an operation clock having a first frequency is generated. When the inverter circuit does not generate an AC voltage, a second frequency lower than the first frequency is generated. A discharge lamp lighting device comprising: an operation clock generation circuit that generates an operation clock and supplies the operation clock to the microcomputer. The first control power circuit is
The discharge lamp lighting device according to claim 1, wherein the first control power supply voltage is not generated when the second control power supply circuit generates the second control power supply voltage. The operation clock generation circuit generates an operation clock having the first frequency when the AC voltage generated by the inverter circuit is higher than a predetermined voltage, and the AC voltage generated by the inverter circuit is lower than the predetermined voltage. 2. The discharge lamp lighting device according to claim 1, wherein an operation clock having the second frequency is generated. The discharge lamp according to claim 1, wherein the operation clock generation circuit switches the frequency of the operation clock to be generated to the first frequency after the microcomputer starts the operation of the inverter circuit. Lighting device. The operation clock generation circuit switches the frequency of the operation clock to be generated to the second frequency when the discharge lamp is turned off,
2. The discharge lamp according to claim 1, wherein the microcomputer stops the operation of the inverter circuit after switching the frequency of the operation clock generated by the operation clock generation circuit to the second frequency. Lighting device. The discharge lamp lighting device further includes an abnormality detection circuit that detects an abnormality of the discharge lamp,
The operation clock generation circuit switches the frequency of the operation clock to be generated to the second frequency when the abnormality detection circuit detects an abnormality of the discharge lamp,
6. The discharge lamp according to claim 5, wherein the microcomputer stops the operation of the inverter circuit after switching the frequency of the operation clock generated by the operation clock generation circuit to the second frequency. Lighting device. The discharge lamp lighting device further inputs a command signal instructing the lighting state of the discharge lamp,
The operation clock generation circuit switches the frequency of the operation clock to be generated to the second frequency when the command signal instructs to turn off the discharge lamp,
6. The discharge lamp according to claim 5, wherein the microcomputer stops the operation of the inverter circuit after switching the frequency of the operation clock generated by the operation clock generation circuit to the second frequency. Lighting device.

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