JP2005183067A - Discharge lamp lighting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely prevent a cataphoresis phenomenon in a discharge lamp. <P>SOLUTION: This discharge lamp lighting device comprises: an inverter circuit 4 for converting a D.C. power voltage to a high frequency voltage by driving the turning on/off of a pair of MOS type FETs 5 and 6 by a driving circuit 13; a resonance load circuit part supplied with the high frequency voltage from the inverter circuit 4 and having an inductor 8, a capacitor 8 and the discharge lamp 9; a D.C. component detection circuit 14 for detecting a D.C. component of the voltage applied to the discharge lamp 9; and a duty ratio control circuit 15 for controlling a duty ration when the driving circuit 13 drives the turning-on/off of the MOS type FETs 5 and 6 so that the D.C. component detection value detected by the D.C. component detection circuit 14 is set at a preset value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a discharge lamp lighting device for high-frequency lighting of a discharge lamp and an illumination device using the discharge lamp lighting device.

Conventionally, a light guide made of a resin plate, a fluorescent tube disposed in the vicinity of the side surface of the light guide, a light reflector that reflects the light emitted from the fluorescent tube, and a lighting circuit that drives the fluorescent tube are provided. In a lighting device, when a leakage current occurs due to the capacitance interposed between the fluorescent tube and the light reflector, mercury in the fluorescent tube is drawn to the anode side, which causes a catalysis phenomenon called pink discharge on the cathode side. For this reason, a noise filter is connected between the light reflector and the common terminal of the lighting circuit to suppress the leakage current from the anode side portion and prevent the occurrence of the catalysis phenomenon (for example, patent document) 1).
JP 2001-338513 A

  However, in the conventional case, even if the leakage current from the anode side portion can be suppressed and the occurrence of catalysis phenomenon can be prevented, when the fluorescent lamp is turned on at high frequency by the inverter circuit, the on / off duty of the switch element of the inverter circuit Is unbalanced and a direct current component is superimposed on the lamp voltage or lamp current, causing the mercury in the fluorescent lamp to be biased toward the cathode on the opposite side, or the mercury in the fluorescent lamp is biased toward the cathode when the fluorescent lamp is exposed to cold air from the outside. In such a case, the cataphoresis phenomenon could not be prevented.

  Therefore, the present invention provides a discharge lamp lighting device and an illumination device that can reliably prevent the occurrence of a cataphoresis phenomenon in a discharge lamp.

  In addition, the present invention further provides a discharge lamp lighting device and an illumination device that can prevent the occurrence of striations in which a striped pattern occurs in the discharge lamp.

  The present invention includes an inverter circuit that drives a switch element on and off by a drive circuit to convert a DC power supply voltage into a high-frequency voltage, and an inductor, a capacitor, and a discharge lamp that are supplied with the high-frequency voltage from the inverter circuit. The resonant load circuit unit, the DC component detection circuit for detecting the DC component of the voltage applied to the discharge lamp or the current flowing through the discharge lamp, and the DC component detection value detected by the DC component detection circuit are set in advance. And a duty ratio control circuit for controlling a duty ratio when the drive circuit drives the switch element on and off.

  According to a second aspect of the present invention, there is provided a discharge lamp lighting device provided with a time counter unit for performing duty ratio control by a duty ratio control circuit at a constant cycle.

  According to a third aspect of the present invention, the switching element is turned on / off to convert the DC power supply voltage into a high frequency voltage, and the switching element is turned on so that the on / off duty of the switching element is biased to one side. A drive circuit for driving off, a resonant load circuit unit including an inductor, a capacitor, and a discharge lamp to which a high-frequency voltage is supplied from an inverter circuit, and a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp. A DC component detection circuit to detect, and a duty ratio control circuit to variably control the duty ratio so that the ON / OFF duty of the switch element by the drive circuit is biased to the other according to the DC component detection value detected by the DC component detection circuit; A discharge lamp having a time counter for performing duty ratio control by the duty ratio control circuit at a constant cycle In the light apparatus.

  According to a fourth aspect of the present invention, there is provided an inverter circuit for driving a switch element on and off to convert a DC power supply voltage into a high frequency voltage, and turning on the switch element so that the on / off duty of the switch element is biased to one side. A drive circuit for driving off, a resonant load circuit unit including an inductor, a capacitor, and a discharge lamp to which a high-frequency voltage is supplied from an inverter circuit, and a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp. When the DC component detection circuit to detect and the DC component detection value detected by the DC component detection circuit in the direction in which the on / off duty is biased to one side exceed a predetermined value, the on / off duty of the switch element by the drive circuit is switched to the other DC component detection value in the direction in which the on / off duty is deviated to the other, with the duty ratio variably controlled so that it is biased It exceeds a predetermined value in the discharge lamp lighting apparatus and a duty ratio control circuit for stopping the variable control of the duty ratio.

  According to another aspect of the present invention, there is provided an inverter circuit that converts a DC power supply voltage into a high frequency voltage by driving a switch element on and off by a drive circuit, and an inductor and a capacitor that are supplied with the high frequency voltage from the inverter circuit And a resonant load circuit section having a discharge lamp, a DC component detection circuit for detecting a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp, and a DC component detection value detected by the DC component detection circuit The discharge lamp lighting device includes switching means for switching the connecting direction of the discharge lamp in the resonant load circuit section when the set value is reached.

  Furthermore, the present invention of claim 6 resides in an illuminating device comprising the discharge lamp lighting device according to any one of claims 1 to 4 and a lighting fixture that houses the discharge lamp lighting device.

ADVANTAGE OF THE INVENTION According to this invention, the discharge lamp lighting device and illuminating device which can prevent reliably the generation | occurrence | production of the catholysis phenomenon of a discharge lamp can be provided.
In addition, according to the present invention, it is possible to provide a discharge lamp lighting device and an illumination device that can also prevent the occurrence of a striation phenomenon in which a striped pattern occurs in the discharge lamp.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIG. 1, a commercial power supply 1 is connected to an input terminal of a full-wave rectifier circuit 2 composed of a diode bridge, and a smoothing capacitor 3 is connected to the output terminal of the full-wave rectifier circuit 2 to form a DC voltage source. ing.

  An inverter circuit 4 is connected to the smoothing capacitor 3. The inverter circuit 4 includes a pair of MOS type FETs (field effect transistors) 5 and 6 as switch elements, and a series circuit of the FETs 5 and 6 is connected to the smoothing capacitor 3. The drain terminal of the FET 6 is connected to one end of one filament electrode 9a of the discharge lamp 9 through a first capacitor 7 and an inductor 8 in series, and the source terminal is connected to one end of the other filament electrode 9b of the discharge lamp 9. Connected.

  Between the other ends of the filament electrodes 9a and 9b of the discharge lamp 9, a second capacitor 10 for flowing a preheating current is connected. The inductor 7, the discharge lamp 9, and the second capacitor 10 constitute a resonant load circuit section including an LC series resonant circuit. The first capacitor 7 is a direct current cut capacitor. Diodes 11 and 12 are connected in parallel to the MOS FETs 5 and 6, respectively.

  The MOS FETs 5 and 6 are alternately turned on and off at a desired on / off duty ratio by a drive circuit 13. A lamp voltage applied to the discharge lamp 9 is detected by a DC component detection circuit 14, and a DC component is detected from the detected lamp voltage. The direct current component may be detected by detecting the lamp current flowing through the discharge lamp 9.

  The DC component detection circuit 14 supplies the detected DC component detection value to the duty ratio control circuit 15. The duty ratio control circuit 15 has a duty when the drive circuit 13 drives the MOS FETs 5 and 6 on and off so that the DC component detection value detected by the DC component detection circuit 14 becomes a preset value. For example, the duty ratio is controlled so that the detected DC component value is approximately 0V.

  For example, a fluorescent lamp is used as the discharge lamp 9, and when the direct current component is 1.1 V as a result of lighting the fluorescent lamp against the wind at an ambient temperature of −5 ° C., the lighting starts from the second day. Cataphorus phenomenon due to mercury bias occurred. However, when the DC component was approximately 0V, the cataphorus phenomenon did not occur even after one week had passed since the lighting. By controlling the direct current component to be approximately 0 V in this way, it is possible to prevent the occurrence of the cataphoris phenomenon.

  Specifically, the drive circuit 13 alternately turns on and off the MOS FETs 5 and 6 at a desired on / off duty ratio, whereby high frequency power is output from the inverter circuit 4. This high frequency power is supplied to the resonant load circuit section. As a result, the discharge lamp 9 operates at a high frequency. During this lighting operation, the DC component detection circuit 14 detects a DC component from the lamp voltage and supplies the detected value to the duty ratio control circuit 15.

  The duty ratio control circuit 15 maintains the on / off duty ratio of each of the MOS type FETs 5 and 6 by the drive circuit 13 if the detected value of the DC component is substantially 0V, but when the detected value of the DC component is other than 0V. The on / off duty ratios of the MOS type FETs 5 and 6 by the drive circuit 13 are variably controlled so that the detected value of the DC component becomes substantially 0V. Since the MOS FETs 5 and 6 are alternately turned on and off, the on / off duty ratio of the MOS FET 5 and the on / off duty ratio of the MOS FET 6 are reversed. That is, when the on-duty ratio of the MOS FET 5 is controlled to increase, the on-duty ratio of the MOS FET 6 is controlled to decrease conversely.

  In this way, by controlling the discharge lamp 7 so that the direct current component of the lamp voltage is approximately 0 V, the mercury bias in the discharge lamp 7 is reliably eliminated, and the occurrence of the cataphorus phenomenon can be reliably prevented.

  In this device, if the duty ratio control circuit 15 is set so that the ON / OFF duty ratio variable control of the MOS FETs 5 and 6 is executed after the discharge lamp 9 starts lighting, the duty ratio is set at the start. The ratio control circuit 15 will not operate. Therefore, the direct current voltage is smoothly superimposed on the discharge lamp 9 at the start, and the start-up is improved.

  In this apparatus, if the duty ratio control circuit 15 is set so that the on / off duty ratio variable control of the MOS FETs 5 and 6 is executed only when the temperature around the discharge lamp is 20 ° C. or less, Since the operation of the duty ratio control circuit 15 can be stopped when the ambient temperature is high and the cataphoris phenomenon is unlikely to occur, loss due to variable control of the ON / OFF duty ratio of the MOS type FETs 5 and 6 can be prevented.

  Further, in this apparatus, when the discharge lamp 9 is used in an environment where it is close to the air conditioner and is always exposed to cold air, for example, when the discharge lamp 9 is lit by switching or the like, the duty ratio control circuit 15 always If variable control of the on / off duty ratios of the MOS type FETs 5 and 6 can be executed, the occurrence of the cataholith phenomenon can be surely prevented even when the apparatus is used in a place where the cataphorus phenomenon easily occurs.

(Second Embodiment)
In addition, the same code | symbol is attached | subjected to the part same as embodiment mentioned above, and detailed description is abbreviate | omitted.
As shown in FIG. 2, a time counter unit 16 is provided, and the duty ratio control circuit 15 is operated at a constant period by a signal from the time counter unit 16.

  In such a configuration, when the discharge lamp 9 is lit, the duty ratio control circuit 15 causes the detected value to be approximately 0V if the detected value of the DC component from the DC component detecting circuit 14 is other than approximately 0V. The on / off duty ratio of each of the MOSFETs 5 and 6 by the drive circuit 13 is variably controlled to prevent the occurrence of the cataphoris phenomenon.

  When a predetermined time has elapsed, the duty ratio control circuit 15 stops the variable control of the on / off duty ratios of the MOS type FETs 5 and 6 by a signal from the time counter unit 16. When this state continues for a certain time, the duty ratio control circuit 15 starts variable control of the ON / OFF duty ratio of the MOS FETs 5 and 6 again by a signal from the time counter unit 16.

By the way, in the state where there is no direct current component of the lamp voltage and the lamp current, the cataphorus phenomenon does not occur, but the striation phenomenon in which a striped pattern occurs in the discharge lamp 9 occurs.
On the other hand, since the variable control of the ON / OFF duty ratio of the MOS type FETs 5 and 6 by the duty ratio control circuit 15 is stopped for a certain period of time, the control for setting the DC component to approximately 0 V is stopped during that time. Accordingly, during this time, the direct current component becomes other than approximately 0 V, thereby preventing the occurrence of the striation phenomenon.

  In this way, it operates so as to prevent the occurrence of the cataholith phenomenon for a certain period of time, and operates so as to prevent the occurrence of the next striation phenomenon for a certain period of time. It is possible to prevent the occurrence of a striation phenomenon as well as to prevent the occurrence.

In the case where the duty ratio control circuit 15 is operated at a constant period in this way, for example, the on-state of the MOS type FETs 5 and 6 is turned on while the variable control of the off-duty ratio is stopped by the duty ratio control circuit 15. The drive circuit 13 controls the on / off duty ratio of the MOS type FETs 5 and 6 so that a DC component biased to one side is generated in the discharge lamp 9 by the off drive, and the on / off duty ratio is variable by the duty ratio control circuit 15. When the control is started, the drive circuit 13 controls the on / off duty ratios of the MOS type FETs 5 and 6 so that a biased DC component is generated in the discharge lamp 9 by the on / off driving of the MOS type FETs 5 and 6. To do.
By performing such control, variable control of the on / off duty ratio by the duty ratio control circuit 15 may be only one direction of increasing or decreasing the on-duty in the case of the MOS type FET 5. Variable control of the ratio is facilitated. Then, in one direction of increasing or decreasing the on-duty, mercury in the discharge lamp is biased in one direction during a certain period of time when the variable control of the on / off duty ratio by the duty ratio control circuit 15 is stopped. This is the direction in which a direct current component is generated in the direction of returning the current to the other direction.

  In this embodiment, the duty ratio control circuit 15 is operated at a constant period. However, the present invention is not necessarily limited to this. For example, when the DC component detected by the DC component detection circuit 14 is a DC component that biases mercury in one direction and its value exceeds a predetermined value A, the duty ratio control circuit 15 starts variable control of the on / off duty ratio. Thus, the direct current component of the discharge lamp 9 is changed to a direct current component in which mercury is biased in the other direction, and the direct current component detected by the direct current component detection circuit 14 is a direct current component in which mercury is biased in the other direction. When exceeding, the variable control of the on / off duty ratio by the duty ratio control circuit 15 may be stopped to change the direct current component of the discharge lamp 9 to a direct current component in which mercury is biased in one direction. In this case, the predetermined value A may be set to a value immediately before the occurrence of the cataholith phenomenon when the mercury is biased in one direction, and the predetermined value B may be set to a value immediately before the occurrence of the cataphorism phenomenon due to the bias of mercury in the other direction. .

(Third embodiment)
In addition, the same code | symbol is attached | subjected to the part same as embodiment mentioned above, and detailed description is abbreviate | omitted.
As shown in FIG. 3, the duty ratio control circuit is not used and a switching means 17 is provided instead. That is, the switching means 17 is connected between the inductor 8 and the discharge lamp 9.

  The switching means 17 is controlled to be switched by the DC component detection means 141. The DC component detection means 141 detects a DC component from the lamp voltage applied to the discharge lamp 9, and the detected value of the detected DC component is detected. Is set to a preset value, the connection direction of the discharge lamp 9 is switched. That is, the inductor 8 connected to one end of one filament electrode 9a of the discharge lamp 9 is switched to one end of the other filament electrode 9b, and the source terminal of the MOS FET 6 is the other filament electrode of the discharge lamp 9 The one connected to one end of 9b is switched to one end of one filament electrode 9a. This switching may be switching by a mechanical contact or switching by a semiconductor switch.

  When the switching means 17 switches the connection of the discharge lamp 9, the discharge of the discharge lamp 9 is stopped. That is, when the detected value of the DC component detected by the DC component detecting means 141 becomes a set value, the drive circuit 131 controls the switching of the MOS FETs 5 and 6 of the inverter circuit 4 by the detection signal S1 from the DC component detecting means 141. Is stopped, and the discharge of the discharge lamp 9 is stopped.

  When the detection signal S1 is input, the switching means 17 switches the connection of the discharge lamp 9 with a predetermined delay time. When this switching is completed, the DC component detecting means 141 is notified of the end. When the DC component detecting means 141 is notified of the end of switching, it outputs a relighting signal S2 to the drive circuit 131. When the re-lighting signal S2 is input, the drive circuit 131 resumes the switching control of the MOS type FETs 5 and 6 of the inverter circuit 4 to preheat the discharge lamp 9 and start lighting.

  When the discharge lamp 9 is lit with the connection of the discharge lamp 9 switched, the DC component detecting means 141 detects a DC component from the lamp voltage applied to the discharge lamp 9. When the detected value of the detected direct current component reaches a preset value, the drive circuit 131 stops the operation of the inverter circuit 4 to stop the discharge lamp 9, and in this state, the switching means 17 causes the switching means 17 to discharge the discharge lamp 9. Switch the connection of to the initial state.

  In this way, the DC component detection unit 141 detects the DC component from the lamp voltage applied to the discharge lamp 9, and the switching unit 17 sets the detected value of the detected DC component to a preset value. Therefore, the direction of the direct current component applied to the discharge lamp 9 is reversed before the mercury in the discharge lamp 9 is biased and the cataphoris phenomenon occurs, thereby preventing the occurrence of the cataphoris phenomenon. Can do. Moreover, since the connection of the discharge lamp 9 is switched while the lighting of the discharge lamp is stopped, the switching can be performed smoothly without any trouble.

(Fourth embodiment)
In this embodiment, an illumination device incorporating the discharge lamp lighting device of each of the embodiments described above will be described.
FIG. 4 shows a lighting device 100. The lighting device 100 has a discharge lamp 103 attached to a socket 102 of a lighting fixture 101, and the discharge lamp lighting device 104 of any of the above-described embodiments is incorporated therein. The discharge lamp 103 is lit by the electric lamp lighting device 104.

  In this way, an illuminating device incorporating the discharge lamp lighting device of each of the embodiments described above can be realized, and even in this illuminating device, the occurrence of the catahollis phenomenon in the discharge lamp 103 can be prevented. In addition, when the discharge lamp lighting device described in the second embodiment is incorporated, it is possible to further prevent the occurrence of a striation phenomenon.

The circuit block diagram containing the one part block which shows 1st Embodiment of this invention. The circuit block diagram containing the one part block which shows 2nd Embodiment of this invention. The circuit block diagram containing the one part block which shows 3rd Embodiment of this invention. The perspective view of the illuminating device which shows 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 4 ... Inverter circuit, 5 and 6 ... MOS type FET, 8 ... Inductor, 9 ... Discharge lamp, 10 ... 2nd capacitor, 13 ... Drive circuit, 14 ... DC component detection circuit, 15 ... Duty ratio control circuit.

Claims (6)

An inverter circuit that converts the DC power supply voltage into a high-frequency voltage by driving the switch element on and off by the drive circuit;
Resonant load circuit unit including an inductor, a capacitor and a discharge lamp, to which a high-frequency voltage is supplied from the inverter circuit,
A DC component detection circuit for detecting a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp;
A duty ratio control circuit that controls a duty ratio when the drive circuit drives the switch element on and off so that the DC component detection value detected by the DC component detection circuit becomes a preset value;
A discharge lamp lighting device comprising: An inverter circuit that converts the DC power supply voltage into a high-frequency voltage by driving the switch element on and off by the drive circuit;
Resonant load circuit unit including an inductor, a capacitor and a discharge lamp, to which a high-frequency voltage is supplied from the inverter circuit,
A DC component detection circuit for detecting a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp;
A duty ratio control circuit that controls a duty ratio when the drive circuit turns on and off the switch element so that the DC component detection value detected by the DC component detection circuit becomes a preset DC value;
A time counter unit for performing duty ratio control by the duty ratio control circuit at regular intervals;
A discharge lamp lighting device comprising: An inverter circuit that drives the switch element on and off to convert the DC power supply voltage into a high-frequency voltage; and
A drive circuit that drives the switch element on and off so that the on / off duty of the switch element is biased to one side;
Resonant load circuit unit including an inductor, a capacitor, and a discharge lamp, to which a high-frequency voltage is supplied from the inverter circuit;
A DC component detection circuit for detecting a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp;
A duty ratio control circuit that variably controls the duty ratio so that the on / off duty of the switch element by the drive circuit is biased to the other according to the DC component detection value detected by the DC component detection circuit;
A time counter unit for performing duty ratio control by the duty ratio control circuit at regular intervals;
A discharge lamp lighting device comprising: An inverter circuit that drives the switch element on and off to convert the DC power supply voltage into a high-frequency voltage; and
A drive circuit that drives the switch element on and off so that the on / off duty of the switch element is biased to one side;
Resonant load circuit unit including an inductor, a capacitor, and a discharge lamp, to which a high-frequency voltage is supplied from the inverter circuit;
A DC component detection circuit for detecting a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp;
When the DC component detection value detected by the DC component detection circuit in the direction in which the on / off duty is biased to one side exceeds a predetermined value, the duty ratio is set so that the on / off duty of the switch element by the drive circuit is biased to the other side. A duty ratio control circuit that performs variable control and stops variable control of the duty ratio when a DC component detection value in a direction in which the on / off duty is biased to the other detected by the DC component detection circuit exceeds a predetermined value;
A discharge lamp lighting device comprising: An inverter circuit that converts the DC power supply voltage into a high-frequency voltage by driving the switch element on and off by the drive circuit;
Resonant load circuit unit including an inductor, a capacitor and a discharge lamp, to which a high-frequency voltage is supplied from the inverter circuit,
A DC component detection circuit for detecting a DC component of a voltage applied to the discharge lamp or a current flowing through the discharge lamp;
Switching means for switching the connecting direction of the discharge lamp in the resonant load circuit section when the DC component detection value detected by the DC component detection circuit becomes a preset value;
A discharge lamp lighting device comprising: The discharge lamp lighting device according to any one of claims 1 to 5,
A lighting fixture that houses the discharge lamp lighting device;
An illumination device comprising:

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