JP2009151971A - High-pressure discharge lamp lighting device and illumination apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp lighting device which can carry out safely lighting control of a high-pressure discharge lamp without making an abnormal state of a stem of the high-pressure discharge lamp continue. <P>SOLUTION: A stem abnormality detection means 26 detects discharge between stems of a high-pressure discharge lamp 12 based on a lamp current detected by a current detector 24 and a lamp voltage detected by a voltage detector 25 at the start of the high-pressure discharge lamp 12. A control circuit 27 switching controls an inverter circuit 22 when the stem discharge detection circuit 26 does not detect the stem discharge, and stops the inverter circuit 22 and a pulse voltage generating circuit 23 when the stem discharge detection circuit 26 detects the stem discharge. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a high pressure discharge lamp lighting device and a lighting fixture for lighting a high pressure discharge lamp.

  In general, a high-pressure discharge lamp has a characteristic of starting a discharge by changing from a glow discharge to an arc discharge. Therefore, it is necessary to apply a high voltage for a predetermined time for the arc discharge transition. For example, when starting a high pressure discharge lamp, a pulse voltage of 5 kV is superimposed on a 300 V rectangular wave and applied to the high pressure discharge lamp to start.

  In the high pressure discharge lamp, gas leaks from the inner tube (light emitting tube) at the end of its life, the gas accumulates in the outer tube, and abnormal discharge occurs between the metal parts that support the arc tube in the outer tube of the discharge lamp when a high pressure pulse is applied (In-tube discharge). Another abnormal discharge state predicted at the end of the life of the high-pressure discharge lamp is a half-wave discharge, which is caused by deterioration of the electrode on one side accompanying the life of the high-pressure discharge lamp. In this state, the lamp current flowing through the high-pressure discharge lamp is asymmetrical between positive and negative, and is almost short-circuited on one side and almost unloaded on the other side.

Therefore, in order to avoid continuing the discharge state in the outer tube and the half-wave discharge state predicted at the end of the life of the high pressure discharge lamp, when the discharge in the outer tube occurs at the end of the life of the high pressure discharge lamp, When abnormal lighting is determined and abnormal lighting is determined, high voltage pulses are stopped during the time required for the temperature of the metal part supporting the arc tube to cool to a temperature at which discharge in the outer tube cannot occur. In some cases, the discharge phenomenon in the outer tube is avoided (for example, see Patent Document 1).
JP-A-2005-142130

  However, in Patent Document 1, when the high-pressure discharge lamp is turned on / off, and when the high-pressure discharge lamp is turned on and then turned off, the generation of the high-voltage pulse voltage is stopped for a predetermined time. This is to prevent the outer tube discharge phenomenon from continuing, and does not detect whether or not the outer tube discharge phenomenon has occurred.

Further, since the high-pressure discharge lamp does not operate until the abnormal discharge at the end of the life is reached, the discharge state in the outer tube or the half-wave discharge state occurs intermittently.

  When an abnormal lamp is mounted on the high-pressure discharge lamp lighting device, if the inner pressure of the outer tube changes due to leakage of the outer tube of the high-pressure discharge lamp, discharge may occur between the stems of the high-pressure discharge lamp. In such a case, discharge occurs between the outer tube of the high-pressure discharge lamp and the vicinity of the connection portion of the base, and thus the heat generated by this discharge may increase the temperature of the base and its surroundings.

  An object of the present invention is to provide a high-pressure discharge lamp lighting device and a lighting fixture that can safely control lighting of the high-pressure discharge lamp without continuing the abnormal state of the stem of the high-pressure discharge lamp.

  The high pressure discharge lamp lighting device according to the invention of claim 1 is an inverter means for supplying high frequency power to the high pressure discharge lamp based on a DC voltage of a DC power supply; and a pulse voltage is generated at the start of the high pressure discharge lamp to generate the high pressure discharge lamp. Pulse voltage generation means for outputting to the current detection means; current detection means for detecting the lamp current of the high-pressure discharge lamp; or voltage detection means for detecting the lamp voltage of the high-pressure discharge lamp; A stem abnormal state detecting means for detecting an abnormal state of the stem of the high-pressure discharge lamp based on the detected lamp current or the lamp voltage detected by the voltage detecting means; and the stem abnormal state detecting means detects the abnormal state of the stem. When not detected, the inverter means is controlled to switch and the stem abnormal state detecting means Upon detection of a state control means for stopping said inverter means and said pulse voltage generating means; characterized by comprising a.

  In the present invention and the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified. The inverter means supplies high-frequency power to the high-pressure discharge lamp based on the DC voltage of the DC power supply. For example, the inverter means has two switch elements, and the DC voltage is input to the two switch elements alternately by the control means. The high-frequency power is supplied to a high-pressure discharge lamp that is configured as a half-bridge type that performs on / off control and outputs an AC voltage to the output side and is connected to the output side of the inverter means. In addition to the half-bridge type, a constant current push-pull type, one-stone type, full-bridge type inverter means may be used.

  The pulse voltage generating means generates a pulse voltage when starting the high pressure discharge lamp and outputs it to the high pressure discharge lamp. For example, a pulse of 5 kV is applied to a 300 V rectangular wave supplied from the inverter means when starting the high pressure discharge lamp. The voltage is superimposed and applied to the high pressure discharge lamp.

  The stem abnormal state detecting means detects the abnormal state of the stem of the high pressure discharge lamp based on the lamp current detected by the current detecting means or the lamp voltage detected by the voltage detecting means at the start of the high pressure discharge lamp. It is.

  The abnormal state of the stem is, for example, an abnormal state of current path formation on the stem due to inter-stem discharge or stem melting. Inter-stem discharge refers to discharge that occurs between conductor pins from a base formed in a stem inside an outer tube of a high-pressure discharge lamp.

  The control means stops the inverter means when the stem abnormal state detecting means detects the abnormal state of the stem. This avoids starting the high pressure discharge lamp in an abnormal state of the stem.

  A high pressure discharge lamp lighting device according to a second aspect of the present invention is the high pressure discharge lamp lighting device according to the first aspect, wherein the stem abnormal state detecting means detects a lamp current before a pulse voltage is applied to the high pressure discharge lamp, or When the lamp voltage of the high-pressure discharge lamp decreases before the pulse voltage is applied to the high-pressure discharge lamp, it is determined that an abnormal state of the stem has occurred in the high-pressure discharge lamp.

  If the abnormal state of the stem does not occur in the high-pressure discharge lamp and it is normal, the lamp current will not flow until the discharge is started even if a voltage is applied to the base of the high-pressure discharge lamp. The voltage also maintains the open circuit voltage.

  Therefore, the stem abnormal state detection means detects the lamp current before the pulse voltage that may cause the high-pressure discharge lamp to start discharging, or the lamp voltage of the high-pressure discharge lamp maintains the open voltage. When not, it is determined that an abnormal state of the stem has occurred.

  A high pressure discharge lamp lighting device according to a third aspect of the invention is the high pressure discharge lamp lighting device according to the first aspect, wherein the stem abnormal state detecting means monitors a lamp current or a lamp voltage when the high pressure discharge lamp is restarted, and When the lamp current starts to flow within a predetermined time after the lamp is turned off, or when the lamp voltage of the high-pressure discharge lamp decreases, it is detected that the abnormal state of the stem is detected.

  Once the high pressure discharge lamp is extinguished, it takes time to restart. In other words, it has a characteristic that the starting voltage is low and easily lit when it is turned off for a long time, but on the contrary, the starting voltage is high and it is difficult to turn on in the state immediately after turning off. The present invention uses the characteristics of the high-pressure discharge lamp to monitor the lamp current or lamp voltage when the high-pressure discharge lamp is restarted, and when the lamp current starts to flow within a certain time after the high-pressure discharge lamp is extinguished. Alternatively, when the lamp voltage of the high-pressure discharge lamp decreases, it is detected that the stem is in an abnormal state.

  According to a fourth aspect of the present invention, there is provided a high pressure discharge lamp lighting device comprising: inverter means for supplying high frequency power to the high pressure discharge lamp based on a direct current voltage of a direct current power source; and generating a pulse voltage when starting the high pressure discharge lamp; Pulse voltage generation means for outputting to the current; current detection means for detecting the lamp current of the high-pressure discharge lamp; or voltage detection means for detecting the lamp voltage of the high-pressure discharge lamp; and the voltage at the start of dimming control of the high-pressure discharge lamp A stem abnormal state detecting means for determining that an abnormal state of the stem has occurred when the lamp voltage detected by the detecting means falls once without increasing; and the stem abnormal state detecting means detects an abnormal state of the stem. If not, the inverter means and the pulse voltage generating means are controlled so that the stem abnormal state detecting means When detecting a is a control means for stopping said inverter means and said pulse voltage generating means; characterized by comprising a.

  The present invention detects whether or not an abnormal state of the stem has occurred at the start of dimming control of the high-pressure discharge lamp. When the dimming control of the high-pressure discharge lamp is started, the high-pressure discharge lamp has a characteristic that the lamp voltage rises once and then decreases. When the lamp voltage detected by the detecting means falls once without increasing, it is determined that an abnormal state of the stem has occurred.

  A high pressure discharge lamp lighting device according to a fifth aspect of the invention is the high pressure discharge lamp lighting device according to the fourth aspect of the invention, wherein the stem abnormal state detecting means is configured to detect the voltage when the control means causes the high pressure discharge lamp to be extinguished by dimming control. When the lamp voltage detected by the detecting means is smaller than a predetermined value, it is determined that an abnormal state of the stem has occurred.

  The high-pressure discharge lamp eventually disappears when the lamp current is reduced, but in the case of a normal high-pressure discharge lamp, when the lamp is extinguished, the lamp voltage maintains a predetermined open-circuit voltage. The present invention utilizes this characteristic of the high-pressure discharge lamp, and the stem abnormal state detecting means detects that the lamp voltage detected by the voltage detecting means is a predetermined value (predetermined open voltage) when the lamp current is reduced. When it is smaller, it is determined that an abnormal state of the stem has occurred.

  According to a sixth aspect of the present invention, there is provided a high pressure discharge lamp lighting device comprising: inverter means for supplying electric power to the high pressure discharge lamp based on a direct current voltage of a direct current power supply; and generating a pulse voltage when starting the high pressure discharge lamp; Pulse voltage generating means for outputting; circuit state detecting means for detecting electrical operation of the inverter means; illuminance detecting means for detecting illuminance of the high pressure discharge lamp; and circuit state detecting means when the high pressure discharge lamp is turned on A stem abnormal state detecting means for detecting an abnormal state of the stem of the high-pressure discharge lamp based on the electrical operation of the inverter means detected in step 1 and the illuminance detected by the illuminance detecting means; When an abnormal state is not detected, the inverter means is controlled to switch the stem abnormal state detection means. When detecting the abnormal condition and control means for stopping said inverter means and said pulse voltage generating means; characterized by comprising a.

  According to the present invention, in contrast to the invention according to claim 1, the stem abnormal state detecting means replaces the lamp current detected by the current detecting means or the lamp voltage detected by the voltage detecting means with a circuit state when the high pressure discharge lamp is turned on. The abnormal state of the stem of the high pressure discharge lamp is detected based on the electrical operation of the inverter means detected by the detection means and the illuminance detected by the illuminance detection means.

  A high pressure discharge lamp lighting device according to a seventh aspect of the present invention is the high pressure discharge lamp lighting device according to the sixth aspect, wherein the stem abnormal state detecting means is configured to detect the circuit state detecting means when the illuminance detected by the illuminance detecting means is less than or equal to a predetermined illuminance. When the electrical operation of the inverter means detected in (2) continues the same operation as the lighting operation of the high pressure discharge lamp, it is determined that an abnormal state of the stem has occurred in the high pressure discharge lamp. To do.

  When the abnormal state of the stem does not occur in the high-pressure discharge lamp and it is normal, when the electrical operation of the inverter means performs the lighting operation of the high-pressure discharge lamp, the high-pressure discharge lamp is lit at a predetermined illuminance. Yes.

  Therefore, in the present invention, the stem abnormal state detecting means causes an abnormal state of the stem when the electrical operation of the inverter means performs the lighting operation of the high pressure discharge lamp and the illuminance of the lamp is less than the predetermined illuminance. It is determined that it is.

  A lighting fixture according to an invention of claim 8 is a high-pressure discharge lamp lighting device according to any one of claims 1 to 7; a high-pressure discharge lamp lit by the high-pressure discharge lamp lighting device; An instrument body to be mounted; and

  According to the first and second aspects of the invention, since the abnormal state of the stem can be detected when the high pressure discharge lamp is started, the stem is in an abnormal state before the lighting of the pressure discharge lamp. The life of the high-pressure discharge lamp can be detected, and abnormal heat generation of the outer tube and base of the high-pressure discharge lamp can be prevented.

  According to the invention of claim 3, since it is detected whether or not the stem is in an abnormal state in the time zone in which the high pressure discharge lamp is not extinguished after the lamp is temporarily turned off, the restart of the high pressure discharge lamp is affected. The abnormal state of the stem can be detected.

  According to the invention of claim 4, since the high-pressure discharge lamp is put into the dimming control mode to notice the behavior of the high-pressure discharge lamp and detect whether or not the stem is in an abnormal state. The abnormal state of the stem can be detected. Further, according to the invention of claim 5, not only the behavior of the high pressure discharge lamp becomes remarkable by setting the high pressure discharge lamp to the dimming control mode, but also whether or not the abnormal state of the stem is caused by turning off the high pressure discharge lamp. Therefore, the abnormal state of the stem can be detected more reliably. Thereby, it is possible to detect an abnormality in the high-pressure discharge lamp before reaching the end of the life of the discharge state in the outer tube or the half-wave discharge state.

  According to the sixth and seventh aspects of the invention, since the abnormal state of the stem of the high pressure discharge lamp can be detected based on the electrical operation of the inverter means and the illuminance of the high pressure discharge lamp when the high pressure discharge lamp is turned on, The inverter means can be safely stopped without continuing the state, the life of the high-pressure discharge lamp due to the abnormal state of the stem can be detected, and abnormal heat generation of the outer tube and base of the high-pressure discharge lamp can be prevented. According to invention of Claim 8, the lighting fixture which has an effect of any one of Claims 1 thru | or 7 can be provided.

  FIG. 1 is a block diagram showing an example of a high-pressure discharge lamp lighting device 11 according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of an example of a high-pressure discharge lamp 12 used in the embodiment of the present invention. In FIG. 2, the high-pressure discharge lamp 12 is a ceramic discharge lamp using an alumina tube as the arc tube 13, and the arc tube 13 is made of translucent alumina. The arc tube 13 of the ceramic discharge lamp is chemically and thermally more stable with respect to the metal halide as the enclosure than the quartz glass used in the arc tube of the general high-pressure discharge lamp 12. The arc tube 13 is housed in an outer tube 14 whose inside is kept in vacuum, and a base 15 is provided at one end of the outer tube 14. An AC voltage is applied from the high pressure discharge lamp lighting device 11 between the tip portion 15a of the base 15 and the screw portion 15b.

  A stem 16 is built in the base 15, and the stem 16 is provided with connection pins 17 a and 17 b respectively connected to the tip portion 15 a and the screw portion 15 b of the base 15. The connection pins 17a and 17b are connected to the electrodes of the arc tube 13 by connection conductors 18a and 18b, respectively.

  In such a high-pressure discharge lamp 12, an abnormal state of the stem may occur between the connection pins 17a and 17b of the stem 16 and between the connection conductors 18a and 18b. The high pressure discharge lamp lighting device 11 according to the embodiment of the present invention has a function capable of detecting the abnormal state of the stem.

  In FIG. 1, an example of a high-pressure discharge lamp lighting device 11 according to an embodiment of the present invention includes a DC power source 21 that converts AC from an AC power source 19 into DC and obtains a DC voltage by a rectifier circuit 20. A DC voltage from the DC power source 21 is input to the inverter means 22 and converted into an AC voltage by turning on and off the switch element of the inverter means 22. Further, the pulse voltage generating means 23 generates a pulse voltage when starting the high-pressure discharge lamp 12 and superimposes the pulse voltage on the AC voltage from the inverter means 22. Then, after the high pressure discharge lamp 12 is turned on, the generation of the pulse voltage is stopped.

  The lamp current of the high pressure discharge lamp 12 is detected by the current detection means 24, the lamp voltage of the high pressure discharge lamp 12 is detected by the voltage detection means 25, and is input to the stem abnormal state detection means 26 and the control means 27.

  The stem abnormal state detection means 26 detects a stem abnormality in the high pressure discharge lamp 12 based on the lamp current detected by the current detection means 24 or the lamp voltage detected by the voltage detection means 25 when the high pressure discharge lamp 12 is started. Detects whether a condition has occurred. When the stem abnormal state detection unit 26 does not detect the abnormal state of the stem, the control unit 27 performs switching control on the inverter unit 22 to generate an AC voltage, and generates a pulse voltage from the pulse voltage generation unit 23 to generate a high voltage discharge. The start control of the lamp 12 is continued. Then, when the high-pressure discharge lamp 12 is lit, the process proceeds to lighting control.

  On the other hand, when the stem abnormal state detecting means 26 detects the abnormal state of the stem, the inverter means 22 and the pulse voltage generating means 23 are stopped, and the start control of the high pressure discharge lamp 12 is stopped. As a result, the inverter means can be safely stopped without continuing the abnormal state of the stem, and even if the discharge between the stems occurs without reaching the discharge state in the outer tube or the half-wave discharge state, the abnormality of the high-pressure discharge lamp is prevented. It can be detected.

FIG. 3 is a configuration diagram showing another example of the high-pressure discharge lamp lighting device 11 according to the embodiment of the present invention. In another example, in contrast to the example shown in FIG.
Based on the illuminance detected by the illuminance detection means 32 and the electrical operation of the inverter means detected by the circuit state prefecture means 33, the abnormal state of the stem of the high-pressure discharge lamp is detected. The same elements as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  The lamp current of the high pressure discharge lamp 12 is detected by the current detection means 24, and the lamp voltage of the high pressure discharge lamp 12 is detected by the voltage detection means 25 and input to the control means 27. The stem abnormal state detection means 26 inputs the illuminance of the high-pressure discharge lamp 12 detected by the illuminance detection means 32 when the high-pressure discharge lamp 12 is lit, and the electric power of the inverter means 22 detected by the circuit state detection means 33. The target action.

  The abnormal stem state detection means 26 detects whether or not an abnormal stem state has occurred in the high pressure discharge lamp 12 based on the illuminance of the high pressure discharge lamp 12 and the electrical operation of the inverter means 22. For example, when the illuminance detected by the illuminance detection means 32 is less than or equal to a predetermined illuminance, the stem abnormal state detection means 26 determines that the electrical operation of the inverter means 22 detected by the circuit state detection means 33 is the lighting operation of the high-pressure discharge lamp 12. When the similar operation is continued, it is determined that the abnormal state of the stem has occurred in the high-pressure discharge lamp 26.

  When the stem abnormal state detecting unit 26 does not detect the abnormal state of the stem, the control unit 27 performs switching control of the inverter unit 22 to generate an AC voltage and controls the lighting of the high-pressure discharge lamp 12. On the other hand, when the stem abnormal state detecting means 26 detects the abnormal state of the stem, the inverter means 22 is stopped and the lighting control of the high pressure discharge lamp 12 is stopped. As a result, the inverter means can be safely stopped without continuing the abnormal state of the stem, and even if the abnormal state of the high pressure discharge lamp occurs even if the abnormal state of the stem occurs without reaching the discharge state in the outer tube or the half-wave discharge state. It can be detected.

  FIG. 4 is a waveform diagram of the lamp voltage and lamp current in the starting characteristics of a normal high-pressure discharge lamp 12. At the time of starting the high-pressure discharge lamp 12, for example, a voltage obtained by superimposing a 5 kV pulse voltage V2 on an AC voltage V1 of 300 V is repeatedly applied to the high-pressure discharge lamp 12. If the high-pressure discharge lamp 12 is turned on at time t0, a lamp current I1 flows. In other words, in the case of the normal high-pressure discharge lamp 12, it is not lit when only the AC voltage V1 is applied, but is lit when the pulse voltage V2 is applied.

  FIG. 5 is a waveform diagram of the lamp voltage and lamp current when starting the high-pressure discharge lamp 12 in which the abnormal state of the stem has occurred. In the case of the high-pressure discharge lamp 12 in which an abnormal state of the stem occurs, when an AC voltage V1 of 300 V is applied to the high-pressure discharge lamp 12, the abnormal state of the stem, for example, on the stem due to inter-stem discharge or stem melting. When an abnormal state of current path formation occurs, the lamp current I1 flows. In addition, the lamp voltage V1 'decreases as the lamp current I1 flows. This lamp current I1 is detected by the current detection means 24, and the lamp voltage V1 'is detected by the voltage detection means 25 and input to the stem abnormal state detection means 26.

  Therefore, the abnormal stem state detecting means 26 detects the lamp current I1 before the pulse voltage V2 is applied to the high-pressure discharge lamp 12, or before the pulse voltage V2 is applied to the high-pressure discharge lamp 12. When the lamp voltage V1 ′ of 12 decreases, it is determined that the abnormal state of the stem has occurred in the high-pressure discharge lamp 12. Then, the abnormal stem state detection means 26 notifies the control means 27 that the abnormal stem state has occurred. When the control means 27 is notified that the abnormal state of the stem has occurred in the high-pressure discharge lamp 12, the control means 27 stops the operation of the inverter means 22 and the pulse voltage generation means 23 and starts the operation of the high-pressure discharge lamp 12. To stop. Thereby, the AC voltage V1 and the pulse voltage V2 are not applied to the high-pressure discharge lamp 12.

  In the above description, when the high-pressure discharge lamp 12 is started, the stem abnormal state detection means 26 detects whether or not the abnormal state of the stem has occurred in the high-pressure discharge lamp 12. An abnormal state of the stem may be detected at the start.

  The high-pressure discharge lamp 12 has a characteristic that the starting voltage is low and easily lit when it is turned off for a long time, but on the contrary, the starting voltage is high and it is difficult to turn on immediately after it is turned off. That is, normally, the high-pressure discharge lamp 12 is not restarted for a certain time after the high-pressure discharge lamp 12 is once extinguished. It is detected whether or not the stem is in an abnormal state in the time zone during which the restart is not performed.

  When the high-pressure discharge lamp 12 is normal, the high-pressure discharge lamp 12 is not lit even if it is restarted for a fixed time after the high-pressure discharge lamp 12 is once turned off.

On the other hand, if there is an abnormal state of the stem of the high-pressure discharge lamp, current starts to flow even immediately after the lamp is turned off. Therefore, it is detected whether or not the stem is in an abnormal state in a time zone in which the high-pressure discharge lamp 12 is not essentially restarted.

  That is, the stem abnormal state detection means 26 monitors the lamp current or the lamp voltage when the high pressure discharge lamp 12 is restarted, and when the lamp current starts to flow within a certain time after the high pressure discharge lamp 12 is turned off, Alternatively, when the lamp voltage of the high-pressure discharge lamp 12 decreases, it is detected that the stem is in an abnormal state. When the abnormal state of the stem is detected, the operation of the inverter means 22 and the pulse voltage generation means 23 is stopped. Thereby, it is possible to prevent the abnormal state of the stem from continuing, to prevent abnormal heat generation of the outer tube and the base of the high pressure discharge lamp 12, and to know that the high pressure discharge lamp is at the end of its life.

  Further, instead of at the time of starting or restarting the high pressure discharge lamp 12, an abnormal state of the stem may be detected at the time of dimming control of the high pressure discharge lamp 12. FIG. 6 is a waveform diagram showing the characteristics of the lamp voltage and lamp current at the start of dimming control of the high-pressure discharge lamp. FIG. 6A is a waveform diagram in the case of a normal high-pressure discharge lamp, and FIG. It is a wave form diagram in the case of the high pressure discharge lamp in which the stem is in an abnormal state.

  As shown in FIG. 6A, it is assumed that dimming control of the high-pressure discharge lamp 12 is started at time t1. That is, when the lamp current IL is decreased from the normal lighting current I0 at the time point t1, in the case of a normal high-pressure discharge lamp 12, the lamp voltage VL once increases from the normal lighting voltage V0 at the start of the dimming control, and then decreases. It has the characteristic. On the other hand, in the case of the high-pressure discharge lamp 12 in which the stem is in an abnormal state, as shown in FIG. 6B, the lamp voltage VL decreases immediately from the time t1 without once increasing from the normal lighting voltage V0. . Using this characteristic, it is determined whether or not an abnormal state of the stem has occurred in the high-pressure discharge lamp 12 when shifting to the dimming control mode. That is, when the lamp voltage detected by the voltage detection means 25 is once lowered without increasing once when the dimming control of the high-pressure discharge lamp 12 is started, the stem abnormal condition detecting means 26 indicates that a stem abnormal condition has occurred. judge.

  In this way, by setting the high-pressure discharge lamp 12 to the dimming control mode, the behavior of the high-pressure discharge lamp 12 is made remarkable to detect whether the stem is in an abnormal state. Therefore, the abnormal state of the stem can be detected even while the high pressure discharge lamp 12 is lit.

  Next, the high pressure discharge lamp 12 is set to the dimming control mode, not only making the behavior of the high pressure discharge lamp 12 remarkable, but also increasing the depth of dimming to turn off the high pressure discharge lamp 12 to determine whether or not the stem is in an abnormal state. It is also possible to do. FIG. 7 is a waveform diagram showing the characteristics of the lamp voltage and lamp current when the high-pressure discharge lamp is extinguished, FIG. 7A is a waveform diagram in the case of a normal high-pressure discharge lamp, and FIG. It is a wave form diagram in the case of the high-pressure discharge lamp in the abnormal state.

  As shown in FIG. 7A, when the dimming control of the high-pressure discharge lamp 12 is started at the time t1, and the lamp current IL is decreased from the normal lighting current I0, the dimming is performed in the case of the normal high-pressure discharge lamp 12. At the start of control, the lamp voltage VL once rises from the normal lighting voltage V0 and then falls. Further, when the lamp current IL is decreased at time t2 to increase the depth of dimming and disappear at time t3, the lamp voltage of the high-pressure discharge lamp 12 becomes a predetermined open-circuit voltage Va of the high-pressure discharge lamp 12 and the lamp current. IL becomes zero.

  On the other hand, in the case of the high-pressure discharge lamp 12 in which the stem is in an abnormal state, as shown in FIG. 7B, the lamp voltage VL does not rise immediately from the normal lighting voltage V0 but immediately drops from the time point t1. Further, the lamp current IL is decreased at time t2 to increase the depth of dimming, and at time t3, the current continues to flow because the current path is formed between the stems. Then, the lamp voltage of the high-pressure discharge lamp 12 becomes only a voltage Va ′ that is smaller than the predetermined open-circuit voltage Va of the high-pressure discharge lamp 12.

  Accordingly, when an abnormal state of the stem occurs, since current flows when viewed from the circuit side, apparently no disappearance occurs.

  Using this characteristic, when the high-voltage discharge lamp 12 is extinguished and the lamp voltage detected by the voltage detecting means is smaller than a predetermined value (predetermined open voltage), it is determined that an abnormal state of the stem has occurred.

  As described above, not only the behavior of the high-pressure discharge lamp becomes noticeable by setting the high-pressure discharge lamp 12 to the dimming control mode, but also whether or not the abnormal state of the stem is determined by turning off the high-pressure discharge lamp 12, The abnormal state of the stem can be detected more reliably. Thereby, it is possible to detect an abnormality in the high-pressure discharge lamp before reaching the end of the life of the discharge state in the outer tube or the half-wave discharge state.

  In the above description, the stem abnormal state detecting means 26 detects whether or not the abnormal state of the stem has occurred based on the lamp current or the lamp voltage of the high pressure discharge lamp 12. The wavelength of light emitted from the outer tube of the lamp 12 may be measured to detect whether an abnormal state of the stem has occurred. That is, the stem abnormal state detection means 26 stores in advance the spectrum of light emitted when the normal high-pressure discharge lamp 12 is lit and the spectrum of light emitted when the stem is in an abnormal state. When the spectrum of the light emitted from the light source is the spectrum of the light emitted when the stem is in an abnormal state, the inverter means 22 and the pulse voltage generating means 23 are stopped.

  Thereby, since it is possible to easily detect that the high pressure discharge lamp 12 is in an abnormal state of the stem, the inverter means can be safely stopped without continuing the abnormal state of the stem.

  FIG. 8 is an explanatory diagram of a lighting fixture according to the embodiment of the present invention. The high pressure discharge lamp lighting device 11 according to the embodiment of the present invention constitutes a lighting fixture together with a fixture main body 28 to which the high pressure discharge lamp 12 is mounted. As shown in FIG. 8, the high-pressure discharge lamp 12 is mounted on the socket 29 of the instrument body 28 and is lit by the high-pressure discharge lamp lighting device 11. Light from the lit high-pressure discharge lamp 12 is reflected by the front reflector 30 and irradiated through the front glass 31. According to this lighting fixture, the lighting fixture which has the effect of the high pressure discharge lamp lighting device 11 in embodiment of this invention is obtained.

The block diagram which shows an example of the high pressure discharge lamp lighting device which concerns on embodiment of this invention. Explanatory drawing of an example of the high pressure discharge lamp used by embodiment of this invention. The block diagram which shows another example of the high pressure discharge lamp lighting device concerning embodiment of this invention The wave form diagram of the lamp voltage and lamp current of the starting characteristic of a normal high-pressure discharge lamp. The wave form diagram of the lamp voltage at the time of start-up of the high pressure discharge lamp 12 in which the abnormal state of the stem occurred. The wave form diagram which shows the characteristic of the lamp voltage at the time of the dimming control start of a high pressure discharge lamp, and a lamp current. The wave form diagram which shows the characteristic of a lamp voltage when a high pressure discharge lamp is made to go out, and a lamp current. Explanatory drawing of the lighting fixture concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... High pressure discharge lamp lighting device, 12 ... High pressure discharge lamp, 13 ... Light emission tube, 14 ... Outer tube, 15 ... Base, 16 ... Stem, 17 ... Connection pin, 18 ... Connection conductor, 19 ... AC power supply, 20 ... Rectifier circuit, 21 ... DC power source, 22 ... inverter means, 23 ... pulse voltage generating means, 24 ... current detecting means, 25 ... voltage detecting means, 26 ... stem abnormal state detecting means, 27 ... control means, 28 ... tool body, DESCRIPTION OF SYMBOLS 29 ... Socket, 30 ... Reflector, 31 ... Front glass, 32 ... Illuminance detection means, 33 ... Circuit state detection means

Claims (8)

Inverter means for supplying high frequency power to the high pressure discharge lamp based on the DC voltage of the DC power supply;
Pulse voltage generating means for generating a pulse voltage at the start of the high pressure discharge lamp and outputting the pulse voltage to the high pressure discharge lamp;
Current detection means for detecting the lamp current of the high-pressure discharge lamp or voltage detection means for detecting the lamp voltage of the high-pressure discharge lamp;
A stem abnormal state detecting means for detecting an abnormal state of the stem of the high pressure discharge lamp based on a lamp current detected by the current detecting means or a lamp voltage detected by the voltage detecting means when the high pressure discharge lamp is started;
When the stem abnormal state detecting means does not detect the abnormal state of the stem, the inverter means is controlled to switch, and when the stem abnormal state detecting means detects the abnormal state of the stem, the inverter means and the pulse voltage generating means are stopped. Control means for causing;
A high-pressure discharge lamp lighting device comprising:   The stem abnormal state detecting means detects a lamp current before a pulse voltage is applied to the high-pressure discharge lamp, or a lamp voltage of the high-pressure discharge lamp is detected before a pulse voltage is applied to the high-pressure discharge lamp. 2. The high pressure discharge lamp lighting device according to claim 1, wherein when it is lowered, it is determined that an abnormal state of a stem has occurred in the high pressure discharge lamp.   The stem abnormal state detection means monitors a lamp current or a lamp voltage when the high pressure discharge lamp is restarted, and when the lamp current starts to flow within a certain time after the high pressure discharge lamp is turned off, or the high pressure 2. The high pressure discharge lamp lighting device according to claim 1, wherein when the lamp voltage of the discharge lamp decreases, it is detected that the stem is in an abnormal state. Inverter means for supplying high frequency power to the high pressure discharge lamp based on the DC voltage of the DC power supply;
Pulse voltage generating means for generating a pulse voltage at the start of the high pressure discharge lamp and outputting the pulse voltage to the high pressure discharge lamp;
Current detection means for detecting the lamp current of the high-pressure discharge lamp or voltage detection means for detecting the lamp voltage of the high-pressure discharge lamp;
A stem abnormal state detecting means for determining that an abnormal state of the stem has occurred when the lamp voltage detected by the voltage detecting means at the start of the dimming control of the high pressure discharge lamp has fallen without once increasing;
When the stem abnormal state detecting means does not detect the abnormal state of the stem, the inverter means is controlled to switch, and when the stem abnormal state detecting means detects the abnormal state of the stem, the inverter means and the pulse voltage generating means are stopped. Control means for causing;
A high-pressure discharge lamp lighting device comprising:   The stem abnormal state detection means generates a stem abnormal state when the control means causes the dimming control to extinguish the high pressure discharge lamp and the lamp voltage detected by the voltage detection means is smaller than a predetermined value. The high pressure discharge lamp lighting device according to claim 4, wherein it is determined that the high pressure discharge lamp is operating. Inverter means for supplying power to the high pressure discharge lamp based on the DC voltage of the DC power supply;
Pulse voltage generating means for generating a pulse voltage at the start of the high pressure discharge lamp and outputting the pulse voltage to the high pressure discharge lamp;
Circuit state detecting means for detecting electrical operation of the inverter means;
Illuminance detection means for detecting the illuminance of the high-pressure discharge lamp;
Stem abnormal state detection for detecting an abnormal state of the stem of the high pressure discharge lamp based on the electrical operation of the inverter means detected by the circuit state detection means and the illuminance detected by the illuminance detection means when the high pressure discharge lamp is turned on With means;
When the stem abnormal state detecting means does not detect the abnormal state of the stem, the inverter means is controlled to switch, and when the stem abnormal state detecting means detects the abnormal state of the stem, the inverter means and the pulse voltage generating means are stopped. Control means for causing;
A high-pressure discharge lamp lighting device comprising:   When the illuminance detected by the illuminance detection means is less than or equal to a predetermined illuminance, the stem abnormal state detection means has an electrical operation similar to the lighting operation of the high-pressure discharge lamp detected by the circuit state detection means. The high pressure discharge lamp lighting device according to claim 6, wherein when the operation is continued, it is determined that an abnormal state of the stem has occurred in the high pressure discharge lamp. A high pressure discharge lamp lighting device according to any one of claims 1 to 7;
A high pressure discharge lamp to be lit by the high pressure discharge lamp lighting device;
An instrument body to which the high-pressure discharge lamp is mounted;
A lighting fixture comprising:

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