JP5010987B2 - How to turn on the high-pressure discharge lamp - Google Patents

Description

  The present invention relates to a lighting method for a high-pressure discharge lamp having excellent durability and a large current, and more particularly to a lighting method for a high-pressure discharge lamp capable of preventing damage at the initial stage of lighting.

  High-pressure discharge lamps such as high-pressure mercury lamps form an arc discharge between an anode and a cathode located at the center of the lamp, and from there are called emission line spectra. Strong radiation limited to a certain wavelength and continuous spectrum other than emission lines Radiation is generated. Such high-pressure discharge lamps are used as discharge lamps that emit powerful ultraviolet rays required in the manufacturing process of various electronic devices such as semiconductor integrated circuits (ICs), liquid crystal display devices (LCDs), and printed circuit boards (PCBs). Has been.

  As shown in FIG. 10, a conventional high-pressure discharge lamp having a conductive foil has a light-transmitting envelope comprising an arc tube portion (111a) and sealing tube portions (111b) extending cylindrically at both ends thereof. (111) includes a pair of electrodes of a positive electrode (120) and a negative electrode (130), and an electrode lead rod (121) extending from the electrode is passed through the conductor (122), and thereafter The end is inserted into the sealing body (124). Further, at the rear end of the sealed body (124), a current collecting disk (125) to which the end of the lead-in wire (126) is fixed is disposed in contact with each other. A strip-shaped conductive foil (123) is wound around the surfaces of the conductor (122), the sealing body (124), and the current collecting disk (125), and the sealing body (124) is sealed with the sealing tube portion (111b). ) And the arc tube portion (111a) is filled with mercury and a rare gas.

  In order to light such a high-pressure discharge lamp, a dielectric current is generated in the gas existing between the electrodes due to the potential difference between the electrodes, a discharge path is formed, an inrush current is passed to shift to arc discharge, and then current supply Therefore, it is necessary to stably maintain the arc discharge. For example, when electrons are emitted from the cathode, ionization and excitation occur, an electron avalanche occurs, and discharge starts, but the voltage required for such dielectric breakdown is proportional to the product of the distance between the electrodes and the gas pressure. In an ultra-high pressure mercury lamp in which mercury is solidified before lighting, the pressure inside the bulb is low, and the voltage required for dielectric breakdown between the lamp electrodes is low. When inrush power is subsequently supplied, the inner core electrons of mercury are excited to move to a higher energy level than the ground state, the lamp starts to transition to arc discharge, and then emits when the excited mercury returns to the ground state. Then, it shifts to arc discharge. After the transition to the arc discharge, the lamp voltage rapidly decreases. However, in the region where the arc discharge is stably maintained, the lamp voltage becomes substantially constant even if the lamp current increases, and becomes a so-called specified voltage region.

  A short arc lamp with a short distance between the electrodes is a lamp that generates very high radiance, and the plasma is supported by two electrodes. A large current flows through the anode, and the current density is large.If the electrode consumption is not suppressed, the transmittance may decrease, such as blackening and devitrification, and the flickering of the arc may occur. is there. Various techniques have been developed to solve such lighting problems.

  For example, in the initial stage of lighting, the electrical polarity of the electrode is changed at a faster cycle than the mercury particles that become the starting point of discharge attached to the electrode evaporate, and this polarity change is continued until the electrode is stably discharged. There is a lighting method of a high-pressure mercury lamp characterized by lighting at a low frequency or direct current (Patent Document 1). If the mercury vapor pressure is increased to prevent the spread of the arc, the amount of mercury is large, so that the discharge state becomes unstable at the initial stage of starting the lamp and the lamp may not be lit. It is said that stable lighting can be performed by applying a high frequency with a cycle that can switch polarity to the mercury particles to form a heat spot on the electrode surface and discharging stably from the heat spot. Note that the steady power of the lamp exemplified in this publication is 150 W.

  Further, a method of lighting a high pressure discharge lamp in which a rare gas and mercury are enclosed in an arc tube, an arc length is 2 mm or less, and a cathode tungsten electrode is formed of a single mandrel with a direct current lamp current of 400 W or less. , Supplying a starting current during a predetermined period at the beginning of lamp starting, controlling with a substantially constant current during the lamp rising period, and controlling with a substantially constant power when the lamp is stably lit, and a current with a substantially constant current during the rising period of the lamp. The value is 1 to 2 times the current value at which the constant power can be supplied at the specified minimum voltage when the lamp is stably lit, and the current value of the starting initial current is 0.5 times the current value during the lamp rising period. There is a lighting method of a high-pressure discharge lamp that is 0.9 times or less (Patent Document 2). This is a high-pressure discharge lamp that is lit by DC. When a constant current is supplied at the start of the lamp and then a constant power is supplied at the time of stable lighting, it takes several minutes to stabilize, and the cathode tungsten electrode is scattered by the high lamp current immediately after starting. Tungsten adheres to the tube wall and blackening occurs. Therefore, Patent Document 2 uses a single mandrel to suppress electrode melting, and when the position of the arc spot immediately after starting is unstable, the current is set appropriately low to suppress electrode scattering, It is said that the burden can be reduced, the startability is not impaired, and the original long life of the lamp can be maintained.

  Further, the pair of electrodes is a high-pressure discharge lamp in which tip portions thereof are disposed so as to face each other in the arc tube, and an axial unit is provided at a tip of at least one electrode shaft of the pair of electrodes. There is a high-pressure discharge lamp in which an electrode portion having a volume per length larger than the axial portion of the electrode shaft is formed and a protrusion is provided in a portion facing the electrode tip of the other electrode (patent) Reference 3). Conventional short arc type ultra-high pressure mercury lamps used a tungsten electrode with a coil at the tip of the same structure as the conventional long arm type high pressure discharge lamp, but the arc tube is blackened only by heat radiation from the coil. It cannot be prevented. In particular, in the case of a short arc type lamp having a distance between electrodes of 2.0 to 5.0 mm, an arc jump phenomenon occurs in which the electrode bright spot moves in a disorderly manner without being stabilized as the lamp lighting time elapses. The brightness on the screen fluctuates. Therefore, in Patent Document 3, by providing a protrusion at the portion facing the electrode tip, the heat capacity of the electrode tip is made larger than before, making it difficult to be deformed and consumed by heat, and suppressing the occurrence of arc jumps. Is to do.

  Furthermore, during a period of less than 5 seconds after starting the lamp, it is started by supplying a direct current, and then the supply current is switched to an alternating current and controlled with a substantially stable current. The value of AC current at the time of approximately constant current control shall be 1 to 2 times the current value at which constant power can be supplied at the specified minimum voltage for stable lighting, and the DC current value after starting the lamp will be AC at the time of approximately constant current control. There is also a lighting method for a high-pressure discharge lamp in which the current value is 0.5 to 0.9 times (Patent Document 4). When starting the lamp with a high-voltage pulse voltage, in the case of a rectangular wave AC lamp current, the current is temporarily interrupted at the moment when the polarity of the rectangular wave switches, and a commutation error occurs at the beginning of the cold start when the electrode temperature is low. On the other hand, the transition from glow to arc becomes difficult and causes blackening of the lamp. On the other hand, starting with DC output places a heavy burden on the lamp electrode on the positive electrode side and affects the lamp life. Therefore, in Patent Document 4, the DC current value at the start of startup and the subsequent AC current value controlled by a substantially constant current are appropriately set separately to prevent dissolution of the electrode due to the DC current, and with sufficient AC current. It aims to get up early.

Furthermore, a lighting method of a high-pressure discharge lamp provided with a pair of electrodes facing each other inside the arc tube and sealed with mercury, a rare gas and a halogen, and after the start of discharge, the transient until mercury has finished evaporating In a predetermined time in the state, after the discharge state between the pair of electrodes shifts to arc discharge, when an increase in the lamp voltage until exceeding a predetermined voltage is detected, control to reduce the lamp current is performed. There is also a lighting method of a high-pressure discharge lamp (Patent Document 5). In an ultra-high pressure mercury lamp with a rated power of 150 W, an abnormal arc tube blackening phenomenon occurs within 500 hours of aging, and ionized ions attack the electrode base, and this impact causes tungsten as the material for the electrode base. It is found that an abnormal arc tube blackening phenomenon occurs during the initial stage after the start of lighting, and in Patent Document 5, the lamp is used within a predetermined time in a transient state until the mercury has completely evaporated after the start of discharge. When the voltage rise is detected, the lamp current is reduced.
JP 2000-133206 A JP 2001-307896 A JP 2001-312997 A JP 2001-273984 A JP 2003-297594 A

  Currently, in order to secure a large amount of light, the size of the lamp is increased, a lamp with a power exceeding 1 kW is frequently used, and a large current of 100 A or more is flowing. Due to this large current, a large amount of Joule heat is generated at the electrode, and the heat generated by arc discharge causes the ultrahigh pressure lamp to be heated to a high temperature during lighting, and thermal breakdown is likely to occur. For example, as shown in FIG. 10, the arc tube portion (111a) and a sealing tube portion (111b) extending in a cylindrical shape at both ends thereof, the arc tube portion (111a), the conductor (122), Quartz constituting the sealed body (124) and a conductor (122) such as molybdenum are greatly different in thermal expansion coefficient. Therefore, in a high-current high-pressure discharge lamp, the lamp is easily damaged by rapid heating. In particular, such a thermal shock is likely to occur at the beginning of lighting when the temperature changes drastically. In addition, the ultra-high pressure mercury lamp cannot be turned on instantaneously and is turned on continuously after being turned on once, but it is often difficult to turn it on again when it is turned on. Under such circumstances, development of a stable lighting method capable of avoiding lamp destruction in a high-current high-pressure discharge lamp is desired.

  However, the method described in Patent Document 1 applies a frequency having a cycle in which the polarity of the electrode can be switched, and is originally intended for lighting with a small lamp of about 150 W. Therefore, a high-pressure discharge lamp that supplies direct current, particularly a large-sized one, is difficult to discharge by switching the polarity of the electrode because the size of the anode is clearly larger than that of the cathode. It cannot be applied. Patent Document 4 also has the same effect as Patent Document 1 in that a direct current and an alternating current are applied, and is difficult to apply to a large-sized high-pressure discharge lamp.

  In addition, Patent Document 3 and Patent Document 5 have an electrode portion having a convex curved shape at the tip portion that is larger in diameter than the electrode shaft in order to prevent the occurrence of an arc jump phenomenon. This technique is characterized by the use of an electrode having a protrusion formed in the vicinity of the center, and has a conventional electrode configuration, which is not a technique that can be widely applied to large-sized high-pressure discharge lamps.

  Furthermore, the technique described in Patent Document 2 is limited to a high-pressure discharge lamp of 400 W or less, and when applied to a high-pressure discharge lamp with an output of 1 kW or more, the lamp breaks due to thermal shock due to high temperature. There is.

  Further, when the high-pressure discharge lamp is increased in size, the lamp input becomes wider as the lamp input becomes larger, and the possibility that the arc is stabilized outside the electrodes also increases. In particular, large high-pressure discharge lamps, unlike small lamps, are stable in abnormal discharge, causing sudden thermal distortion to the light emitting bulb, which increases the possibility of lamp breakage. There is a higher need to effectively prevent. As described above, Patent Documents 1 to 5 cannot solve the problem of breakage and abnormal discharge in a large-sized high-pressure discharge lamp.

  Accordingly, an object of the present invention is to provide a discharge lamp lighting method that can cope with an increase in the size of the lamp and a large current.

  The inventors of the present invention have a high-voltage rated output of 5 to 50 kW, which has a pair of electrodes with an inter-electrode distance of 4 to 50 mm facing each other, has an arc tube filled with mercury, and is lit by a DC lamp current. As a result of a detailed examination of the method of lighting the discharge lamp, if an inrush current is supplied to discharge and the initial current and rising current are supplied while increasing the supply current amount after a current drop, the voltage is gradually increased and then rated. Since it can be shifted to the output, rapid increase in lamp voltage and increase in lamp temperature can be suppressed, heat shock to the lamp can be avoided, and even when a pair of electrodes having an interelectrode distance of 4 to 50 mm is used. Abnormal discharge is easy to detect, and even if an abnormal rise in lamp voltage linked to abnormal discharge is detected, if the amount of supplied current is reduced, the error due to abnormal discharge is detected. It found that may avoid up breaking, and completed the present invention.

That is, the present invention is a high voltage with a rated output of 5 to 50 kW, in which a pair of electrodes with an interelectrode distance of 4 to 50 mm are arranged to face each other, has an arc tube filled with mercury, and is lit by a direct current lamp current. A method for lighting a discharge lamp, which supplies and discharges an inrush current, and supplies an initial current, a rising current, and a stable current after a current drop, and the supply amount of the initial current is the rated output current and 70 to 95%, followed by the initial current supplied to the rising current while increasing the amount of current to the rated output current from and then a high-pressure discharge lamp lighting method for supplying a rated output current as the stable state current, after the start of the supply of the rush current, supply when the lamp voltage exceeds a predetermined value or voltage regulation, the supply amount of the lamp current is stopped, then the inrush current after a predetermined time has elapsed Characterized Rukoto, there is provided a high-pressure discharge lamp lighting method.

  Further, according to the present invention, when the lamp voltage exceeds a predetermined value or the voltage fluctuation rate after the start of the supply of the initial current, the supply amount of the lamp current is reduced and then supplied while increasing to the rated output current. A method for lighting the high-pressure discharge lamp is provided.

In addition, the present invention provides a high pressure with a rated output of 5 to 50 kW, in which a pair of electrodes having an interelectrode distance of 4 to 50 mm are arranged to face each other, has an arc tube filled with mercury, and is lit by a DC lamp current. A method for lighting a discharge lamp, which supplies and discharges an inrush current, and supplies an initial current, a rising current, and a stable current after a current drop, and the supply amount of the initial current is the rated output current 70 to 95%, and then, as a rising current, a rising early current that is 60% or more and less than 100% of the initial current and a rising late current that increases to a rated output current thereafter are supplied, and then the stable current as a high-pressure discharge lamp lighting method for supplying a rated output current, after the start of supply of the rush current, when the lamp voltage exceeds a predetermined value or voltage regulation, La The supply amount of up current is stopped, then, and supplying the rush current after a predetermined time has elapsed, there is provided a high-pressure discharge lamp lighting method.

  The present invention also provides a method for lighting the high-pressure discharge lamp, wherein the initial current supply time is 1 to 20 minutes.

  The present invention also provides a method for lighting the high-pressure discharge lamp, wherein the period from the start of the rising current supply to the start of supply of the stable current is 13 to 70 minutes.

  According to the lighting method of the high-pressure discharge lamp of the present invention, it is possible to avoid breakage during lighting of the high-pressure discharge lamp having a rated output of 5 to 50 kW.

  According to the lighting method of the high-pressure discharge lamp of the present invention, even if an abnormal discharge or the like occurs, this can be easily detected, and the lamp breakage due to the abnormal discharge can be prevented.

  The first of the present invention has a rated output of 5 to 50 kW, which is provided with a pair of electrodes facing each other with a distance of 4 to 50 mm facing each other, has an arc tube filled with mercury, and is lit by a DC lamp current. A method of lighting a high-pressure discharge lamp, which supplies and discharges an inrush current, and supplies an initial current, a rising current, and a stable current after a current drop, and the supply amount of the initial current is a rated output current 70% to 95%, and then a rising current is supplied while increasing the amount of current from the initial current to the rated output current, and then the rated output current is supplied as the stable current. Is the lighting method. When the lamp voltage exceeds a predetermined value or voltage fluctuation rate after the start of the supply of the initial current, the supply amount of the lamp current may be reduced to the initial current and then supplied while increasing to the rated output current. .

  When a current is supplied to the high-pressure discharge lamp, dielectric breakdown occurs between the electrodes, and discharge occurs due to the supply of the inrush current. When the current is supplied after the lamp current drops after the discharge, the output finally shifts to the rated output. Conventionally, it has been common to supply a rated output current or a current higher than the rated output current as an initial current immediately after a current drop after discharging due to an inrush current. As an example of such a mode, 170 A is supplied as an initial current (I) to a high-pressure discharge lamp having a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW, and a current amount up to the rated output current as a rising current (II). FIG. 6 shows changes over time in the lamp voltage and the lamp current when the voltage is gradually decreased and the current is shifted to the rated output as the stable current (III) after about 10 minutes. According to this lighting method, since the initial current value is high, there is an advantage that the lighting time can be shortened, but the lamp breakage due to the heat shock cannot be avoided.

  Therefore, in the present invention, after the current drop after the discharge due to the inrush current, a current of 70 to 95% of the rated output current is supplied as the initial current, then the current is increased to the rated output current, and then the rated output current is supplied to discharge. We decided to keep it stable. If the lamp voltage exceeds a predetermined value or voltage fluctuation rate after the start of the supply of the initial current, the supply amount of the lamp current may be reduced and then supplied while increasing to the rated output current. As a result, even when the discharge is stable except between the electrodes, abnormal discharge can be avoided and stable lighting can be achieved. Hereinafter, the present invention will be described in detail.

  In the present invention, a high-pressure discharge lamp having a rated output of 5 to 50 kW, which has a pair of electrodes with a distance of 4 to 50 m facing each other, has an arc tube filled with mercury, and is lit by a DC lamp current. Is targeted. The distance between the electrodes is 4 to 50 m, more preferably 10 to 35 mm. When the lamp is enlarged and the distance between the electrodes is increased, abnormal discharge that is sustained even after the discharge is likely to occur, but according to the lighting method of the present invention, abnormal discharge is avoided or efficiently performed. By detecting, destruction of the high-pressure discharge lamp can be avoided and stable lighting can be achieved.

  In the present invention, a high-pressure discharge lamp having a rated output of 5 to 50 kW, more preferably 5 to 35 kW is targeted. The rated output current is 70 to 250A, more preferably 100 to 200A. A lamp that energizes such a large current has a large amount of heat generation, and thus a lamp breakage is likely to occur due to a rapid temperature change at the time of lighting. However, according to the lighting method of the present invention, such a lamp breakage is avoided. Can be lit safely.

  In the high-pressure discharge lamp, mercury is enclosed in an arc tube and light is emitted by arc discharge. In addition to mercury, a rare gas such as xenon or argon is enclosed in the arc tube in order to assist dielectric breakdown. May be. The amount of mercury or rare gas enclosed can be appropriately selected according to the emission line spectrum, the optical characteristics of the lamp, and the like.

  The present invention is characterized in that an inrush current is supplied and discharged at the time of lighting, and an initial current (I), a rising current (II), and a stable current (III) are supplied after a current drop. The initial current (I) is a current that is first supplied in a state in which discharge is generated by supplying an inrush current and then the discharge is unstable. The stable current (III) is the current when the rated output is output, and the rising current (II) is the current supplied to shift from the initial current (I) to the stable current (III). is there.

  As an example of a preferred embodiment of the present invention, 120 A is supplied as an initial current (I) to a high-pressure discharge lamp having a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW, and then a rising current (II) of 4 to the rated output current. FIG. 1 shows changes over time in lamp voltage and lamp current when the voltage is increased in stages and the rated output (III) is shifted to after about 54 minutes. In the present invention, the initial current supply is started when the lamp current shows the minimum value immediately after the inrush current supply. Further, the “rated output current” in the present invention means a current value at which constant power can be supplied at a specified minimum voltage when the lamp is stably lit.

  In the present invention, 70 to 95%, more preferably 75 to 90% of the rated output current is supplied as the initial current. When the ratio is less than 70%, abnormal discharge that occurs outside the electrodes increases. On the other hand, when it exceeds 95%, lamp breakage may occur due to rapid heat generation. The initial current supply time is generally 1 to 20 minutes, although it varies depending on the electrode size, the amount of enclosed mercury, and the like. The lamp voltage at the time of supplying the initial current is generally 5 to 30% of the voltage at the rated output.

  Next, a current is supplied while increasing to the rated output current as the rising current (II). Conventionally, for example, as shown in FIG. 6, an initial current higher than the rated output current is supplied, and then the output is shifted to the rated output in about 12 minutes from the start of supply of the initial current. However, high-pressure discharge lamps with a distance between electrodes of 4 to 50 mm and a rated power of 5 to 50 kW have a low arc tube pressure of 0.65 to 2 atm. It's easy to do. As shown in FIG. 7, such an abnormal discharge is not only the destruction of the electrode, but also the heat generated by the discharge is transferred to the arc tube portion, and the entire lamp is easily destroyed. Therefore, in the present invention, an initial current lower than the rated output current is supplied, and then gradually increased to the rated output current while detecting the lamp voltage.

  In the present invention, a stable current (III) is supplied while increasing the voltage by supplying a rising current (II) within the range of the rated output current from the initial current without supplying a high current exceeding the rated output current at the time of lighting. It is characterized in that it shifts to the rated output. At the beginning of lighting of the high-pressure mercury lamp, the mercury inside the lamp is not evaporated, so it is a low value of 5 to 30% of the voltage at the rated output, and even if the initial current (I) is supplied, the voltage value The rise is slight. Therefore, as shown in FIG. 1, after the initial current (I) is supplied, the rising current (II) is supplied to increase both the voltage and the current, and finally the rated output is supplied to supply the stable current (III). Let Note that the rising current (II) does not necessarily exceed the initial current (I). As shown in FIG. 1, 120 A, which is the same as the initial current (I), is supplied, and the supply current is stepwise while detecting a voltage rise. The amount can be increased.

  In the present invention, the supply time of the rising current (II) is 13 to 70 minutes, more preferably 25 to 60 minutes, and particularly preferably 40 to 60 minutes. In this way, by increasing the voltage over time, the rapid voltage increase is suppressed to suppress the thermal destruction of the lamp, and the abnormal discharge is detected by detecting the voltage increase, and the amount of current is controlled. Thus, the lamp can be prevented from being destroyed.

  In the present invention, the “increase” means that the supply amount is increased at each stage even in the “gradual increase” type in which the supply current amount is gradually increased over time as long as it increases from the initial current amount to the rated output current amount. A “step” type may be used. The number of steps in the case of the step type can also be appropriately selected according to the rated output. For example, in the case of 5 or more and 25 kW or less, three or more steps are preferable, and in the case of more than 25 kW and 50 kW, four or more steps are preferable.

  In the present invention, the voltage value is gradually increased by supplying the rising current (II), but there is no particular limitation on the method for increasing the current amount, and the increase amount per unit time is determined and mechanically increased. Alternatively, the amount of current may be increased according to the lamp, such as increasing the amount of current after detecting the lamp voltage and reaching a predetermined voltage. Further, when increasing the lamp current supply amount in the step type, the current increase amount and the required time may be the same or different for each step.

  In the present invention, after the start of the supply of the initial current (I), when the lamp voltage exceeds a predetermined value or the voltage fluctuation rate, the supply amount of the lamp current is reduced and then increased to the rated output current. It may be supplied while. As described above, a high-pressure discharge lamp having a distance between electrodes of 4 to 50 mm and a rated power of 5 to 50 kW is likely to have a stable discharge even between the electrodes. When such abnormal discharge occurs, the voltage rises and the amount of heat generation increases, so that the lamp is likely to be thermally destroyed.However, while the lamp voltage is detected, the lamp voltage is set to a predetermined value or while the initial current is supplied. By detecting an abnormality when the voltage fluctuation rate is exceeded, reducing the lamp current supply amount, and then increasing the current supply amount to the rated output after a predetermined time has elapsed, avoiding the thermal destruction of the lamp due to abnormal discharge Can do.

  As the predetermined value for detecting such an abnormality, a predetermined numerical value may be set in advance based on the rated output of the lamp, the supply current at the time of lighting, etc. It may be specified as a case of exceeding, or may be set in association with any element related to abnormal discharge or the like. For example, 2 to 4 times the voltage at the time of initial current supply when the lamp is normally lit (for example, in the case of a high-pressure discharge lamp with a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW, usually 15 to 40 V), more preferably Can be specified as 2 to 3 times. In addition, the rising current in the present invention is to increase the current stepwise or gradually while increasing the voltage, and is characterized in that rapid thermal destruction is prevented by gradually increasing the voltage. Therefore, instead of the predetermined value of the lamp voltage, for example, the voltage variation rate may be specified as 5 V / second or more, more preferably 10 V / second or more. Further, the lamp current supply amount may be reduced by “stopping” the lamp current supply. In this case, the lamp current may be re-lit by the above method. In the present invention, when an abnormality of the lamp voltage is detected during the supply of the initial current (I), the supply of the current can be reduced to avoid the lamp destruction. What is necessary is just to reduce until it becomes the voltage at the time of the normal current supply at the time of normal lighting (for example, in the case of a high-pressure discharge lamp with a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW, normally 15 to 40 V). FIG. 2 shows the change in voltage and current after the start of the initial current supply when the lamp with the rated output of 35 kW is lit with the initial current of 110 A, and when the lamp is normally lit, FIG. The current and voltage states at the time of an abnormal voltage exhibiting a substantially constant high value are shown, and FIG. 4 shows the current and voltage states at the time of an abnormal voltage in which the voltage fluctuates greatly.

  In the second aspect of the present invention, a pair of electrodes having a distance between electrodes of 4 to 50 mm are arranged to face each other, have an arc tube filled with mercury, and are lit by a DC lamp current, and have a rated output of 5 to 50 kW. A method of lighting a high-pressure discharge lamp, which supplies and discharges an inrush current, and supplies an initial current, a rising current, and a stable current after a current drop, and the supply amount of the initial current is a rated output current Then, as the rising current, a rising early current of 60% or more and less than 100% of the initial current and a rising late current that increases to the rated output current are supplied, and then the stable time A method for lighting a high-pressure discharge lamp, wherein a rated output current is supplied as a current.

  The difference from the first invention is that the rising current (II) is divided into a first period and a second period, and after the initial current (I) is supplied, the first current (I) Current of 60% or more and less than 100% of the current, and then gradually increases to the rated output current as the late rising current (II "). As an example of such a mode, FIG. A high-pressure discharge lamp having a current of 157 A and a rated power of 35 kW is supplied with 140 A as an initial current (I) for 10 minutes, then with 130 A as a rising initial current (II ′) for 10 minutes, and then with a late rising current (II ″) As a result, the lamp voltage and the lamp current change with time when the rated output current is supplied in four stages and is shifted to the rated output after about 54 minutes. It was found that when the initial current (I) is set within the above range, the occurrence of abnormal discharge can be suppressed, and then the voltage of the voltage is reduced by supplying a current lower than the initial current (I) as the initial rising current (II ′). The generation of heat is suppressed by gradually increasing the voltage, and then the applied voltage is increased while the amount of current is increased to shift to the rated output.

  The initial current (I) in the lighting method of the second invention is 70 to 95%, more preferably 80 to 95% of the rated output current. The supply time of the initial current (I) is 1 to 20 minutes, preferably 5 to 15 minutes, more preferably 7 to 12 minutes.

  Next, a current of 60% or more and less than 100%, more preferably 70 to 90% of the initial current (I) is supplied as the initial rising current (II ') to avoid excessive heat generation. Since the initial current (I) is high, lamp breakdown can be suppressed by supplying a reduced amount of current as the initial rising current (II '). Next, the current is supplied while increasing to the rated output current as the rising late current (II ″). That is, the rising early current (II ′) is supplied for 3 to 20 minutes, more preferably 5 to 15 minutes. Further, the supply time of the rising late current (II ″) is 10 to 50 minutes, more preferably 20 to 45 minutes. In order to increase the amount of current by supplying the late-stage current, the “gradual increase” type or the “step” type in which the supply amount is increased at each stage may be used. Therefore, the rising current supply period is 13 to 70 minutes, more preferably 25 to 60 minutes, and particularly preferably 40 to 60 minutes. Thermal shock can be avoided by increasing the amount of current over a sufficient time. If the rated output current is supplied after the elapsed time, the lamp can be lit stably.

  In the first and second inventions, when the lamp voltage exceeds a predetermined value or voltage fluctuation rate after the start of the inrush current supply, the supply amount of the lamp current is stopped, and then a predetermined time has elapsed. An inrush current may be supplied later. If it is not possible to avoid thermal destruction of the lamp only by reducing the supply amount of the lamp current, the supply of current is stopped and the lamp is turned on again after being left for a predetermined time. As described above, a high-pressure discharge lamp having a distance between electrodes of 4 to 50 mm and a rated power of 5 to 50 kW is likely to have a stable discharge even between the electrodes. When such abnormal discharge occurs, the voltage rises and the amount of heat generation increases, so that the lamp is likely to be thermally destroyed.However, while the lamp voltage is detected, the lamp voltage is set to a predetermined value or while the initial current is supplied. An abnormality is detected when the voltage fluctuation rate is exceeded, the lamp is turned off, and the lamp is turned on again. Relighting is performed by the method described above. The abnormal voltage includes a wide range of cases where it is different from the normal voltage, such as a case where the voltage value fluctuates greatly in addition to a case where the abnormal voltage is constant at a high value as described above.

  The abnormal voltage value of the lamp for detecting such an abnormality may be determined in advance based on the rated output of the lamp, the supply current during normal lighting, etc. It may be specified as a case where the amount of change in time is exceeded, or may be set in association with any other element related to abnormal discharge. For example, 1.5 to 5 times the minimum lamp voltage value after supply of inrush current (for example, in the case of a high-pressure discharge lamp having a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW), more preferably 1.5 to 5 times. Can be specified as 2 to 3 times. Further, instead of the abnormal voltage value of the lamp, for example, the voltage at the time of initial current supply when the lamp is normally lit (for example, in the case of a high-pressure discharge lamp with a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW, Can be specified as 2 to 4 times, more preferably 2 to 3 times of 15 to 40 V).

  In addition, after stopping supply of a lamp current, the predetermined time in the case of supplying an inrush current again and relighting can be made into the predetermined time until a lamp cools down.

  Next, a lighting circuit that implements the lighting method and a high-pressure discharge device that includes a high-pressure discharge lamp and a lighting circuit will be described. FIG. 8 shows a lighting circuit of a high-pressure discharge lamp without a starter. A current is supplied from a DC lighting power source through a starter, and the lamp is started.

  In the present invention, in such a high-pressure discharge lamp apparatus including the high-pressure discharge lamp, a lamp voltage detecting means, a lamp current detecting means, and a lamp temperature detecting means as necessary are arranged in the circuit, and the current according to the above conditions is provided. It can be implemented by controlling the amount. For example, when the rising current is increased stepwise, the current value and the amount of electric power are controlled by using relay contacts in parallel or in series as many as the desired number of steps, and by turning the relay contacts on and off. Resistors can be added or deleted to adjust to the specified current value or power value.

  When such a lighting circuit is used and, for example, the start time of a step is defined by elapsed time, a timer relay contact may be used.

  Further, in order to switch by lamp voltage, for example, a variable resistor is provided in the lighting circuit to divide the voltage, and the relay contact to be used is operated with the divided voltage, and the relay contact operating pressure and the set switching pressure are set. Therefore, the resistance may be adjusted by a variable resistor so that the operating voltage of the relay contact matches the voltage at the time of voltage division, and the amount of current may be changed when the lamp voltage reaches a specified value. Also, the amount of current can be controlled so that the rated output is output when the voltage is detected by the above method and the voltage reaches a specified value.

  Next, a method for lighting the high-pressure discharge lamp device according to the lighting method of the present invention will be described.

  First, a current is supplied from a power supply current to the high-pressure discharge lamp. A voltage is applied to the high-pressure discharge lamp to cause dielectric breakdown between the electrodes, and then discharge is started by supplying an inrush current. Dielectric breakdown and discharge can be performed by a conventionally known method.

  In this embodiment, an inrush current is supplied to start discharge between the lamp electrodes, and then an initial current, a rising current, and a stable current are sequentially supplied after the lamp current rapidly decreases.

  As the initial current, 70 to 95% of the rated output current is supplied in the range of 1 to 20 minutes, more preferably 5 to 15 minutes. Next, a rising current is supplied in response to the time when the voltage reaches the specified voltage value or the elapsed time.

  Next, the current supply amount is increased while the voltage is detected by the lamp voltage detection means, and the rated output is shifted to 25 to 60 minutes. In the case of increasing in the step type, the current amount is adjusted by increasing / decreasing the resistance arranged in parallel or in series by ON / OFF operation of the relay contact described above, and finally the rated output is obtained.

  On the other hand, if the voltage exceeds a predetermined value after the initial current is supplied, the amount of supplied current is reduced according to the detected voltage, or the amount of supplied current is stopped, and the current is supplied again after a predetermined period of time, causing dielectric breakdown. Alternatively, an initial current, a rising current, and a stable current may be supplied by causing discharge. Such a system flow is shown in FIG. In FIG. 9, the initial current supply start time is the minimum current after the inrush current supply.

  Even when the lamp voltage exceeds a predetermined value after the inrush current is supplied, the lamp current amount is reduced, and when the lamp voltage is reduced to the lamp voltage at the time of normal lighting, the initial current is supplied. On the other hand, when the lamp voltage is not reduced to the lamp voltage at normal lighting, or when the voltage rises and exceeds the specified abnormal voltage, the output is stopped, and then the inrush current is supplied and insulated after the predetermined time has elapsed. An initial current, a rising current, or a stable current may be supplied by causing breakdown or discharge. The output stop when such an abnormal voltage is detected can be easily implemented by including a voltage limiter circuit in the circuit, for example. Although FIG. 9 shows the case where the lamp voltage exceeds the predetermined value, the same applies to the case where the lamp voltage fluctuation rate exceeds the predetermined value.

  As such an abnormal voltage, for example, a voltage at the time of initial current supply when the lamp is normally lit (for example, in the case of a high-pressure discharge lamp having a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW, is usually 15 to 40 V. 2) to 4 times, more preferably 2 to 3 times. Further, instead of the abnormal voltage value of the lamp, for example, the voltage fluctuation rate may be specified as 5 V / second or more, more preferably 10 V / second or more.

  Then, after the lamp is sufficiently cooled, the lighting operation is started again. In the conventional lighting method, if the usage time of the high-pressure discharge lamp becomes long, re-lighting may become difficult, or the lamp may be thermally destroyed due to abnormal discharge or the like. However, according to the lighting method of the present invention, even during such relighting, the voltage is gradually increased to reach the rated output, so that damage due to heat can be efficiently suppressed. Furthermore, even when the thermal breakdown is likely to occur due to a sudden rise in voltage, the abnormality can be avoided early by detecting the lamp voltage.

  On the other hand, if an abnormal voltage is not detected when the rising current (II) is supplied, the amount of current is gradually increased to reach the rated output. Thereby, stable lighting can be performed.

In the lighting method of this invention, it is a figure which shows the time-dependent change of the electric current and voltage at the time of supplying initial current (I), rising current (II), and the electric current (III) at the time of stability, It is a figure which shows transition of the electric current at the time of making it increase in a step and a voltage. In the lighting method of the present invention, for example, when a high-pressure discharge lamp with a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW is lit with an initial current of 110 A, it shows a change in voltage and current when the lamp is normally lit. is there. For example, when a high-pressure discharge lamp with a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW is lit with an initial current of 110 A, it shows the state of current and voltage when an abnormal voltage showing a high value is displayed near 65 V. is there. For example, when a high-pressure discharge lamp having a rated voltage of 220 V, a rated output current of 157 A, and a rated power of 35 kW is lit at an initial current of 110 A, the voltage changes greatly and the time-dependent change between current and voltage is shown. FIG. In the lighting method of this invention, it is a figure which shows a time-dependent change of the electric current and voltage at the time of supplying the initial current (I), the rising current (II), and the stable current (III). It is a figure which shows transition of the electric current and voltage at the time of flowing the late stage electric current after flowing an initial stage current. It is a figure which shows the time-dependent change of the electric current and voltage in the conventional lighting method. FIG. 8 is a diagram showing a discharge state between the anode and the cathode in the arc tube portion. In FIG. 7, “normal” is a diagram showing a state in which the discharge is stabilized between the anode and the cathode in the arc tube portion. “Abnormal” is a diagram showing a state in which the discharge is stabilized in the arc tube portion except between the anode and the cathode, and the discharge is in contact with the arc tube wall. It is a schematic diagram of the circuit of the high-pressure discharge lamp of the present invention. In the lighting method of this invention, when a lamp voltage exceeds predetermined value, supply of an electric current is stopped and it is a flowchart in the case of lighting again. It is a cross-sectional view explaining a high pressure discharge lamp.

Explanation of symbols

10 ... discharge lamp,
11 ... translucent envelope,
11a: arc tube section,
11b: sealing tube part,
20 ... Positive electrode,
30 ... negative electrode,
40: Sealed body,
49 ... Spring,
50 ... External terminal,
60 ... Electrode lead bar,
65 ... introduction line,
70 ... quartz plate,
73 ... spring 80 ... conductor,
81 ... through-hole,
80c ... Conductor cylindrical portion 85 ... Current collecting disk,
90, 90 '... disc-shaped current collector,
90a ... current collector disk part,
90b ... current collector plate part,
90c ... current collector cylindrical portion,
91 ... through hole,
95 ... conductive foil,
110 ... discharge lamp,
111 ... translucent envelope,
111a ... arc tube section,
111b ... sealing tube part,
120 ... Positive electrode,
121 ... Electrode lead bar,
122: Conductor,
123 ... conductive foil,
124... Sealed body,
125... Current collecting disk,
126 ... introduction line,
127 ... external terminal,
130 ... negative electrode,
s ... Space.

Claims (5)

A method for lighting a high-pressure discharge lamp with a rated output of 5 to 50 kW, which has a pair of electrodes with an electrode distance of 4 to 50 mm facing each other, has an arc tube filled with mercury, and is lit by a DC lamp current. There,
Inrush current is supplied and discharged, and after the current drops, initial current, rising current and stable current are supplied.
The supply amount of the initial current is 70 to 95% of the rated output current,
Next, the rising current is supplied while increasing the amount of current from the initial current to the rated output current,
Then a high-pressure discharge lamp lighting method for supplying a rated output current as the stable state current,
When the lamp voltage exceeds a predetermined value or a voltage fluctuation rate after the start of supplying the inrush current, the supply amount of the lamp current is stopped, and then the inrush current is supplied after a predetermined time has elapsed , How to turn on the high-pressure discharge lamp.   When the lamp voltage exceeds a predetermined value or voltage fluctuation rate after the start of the supply of the initial current, the supply amount of the lamp current is reduced and then supplied while increasing to the rated output current. The lighting method of the high-pressure discharge lamp according to claim 1. A method for lighting a high-pressure discharge lamp with a rated output of 5 to 50 kW, which has a pair of electrodes with an electrode distance of 4 to 50 mm facing each other, has an arc tube filled with mercury, and is lit by a DC lamp current. There,
Inrush current is supplied and discharged, and after the current drops, initial current, rising current and stable current are supplied.
The supply amount of the initial current is 70 to 95% of the rated output current,
Next, as a rising current, a rising early current that is 60% or more and less than 100% of the initial current, and a rising late current that increases to the rated output current thereafter are supplied,
Then a high-pressure discharge lamp lighting method for supplying a rated output current as the stable state current,
When the lamp voltage exceeds a predetermined value or a voltage fluctuation rate after the start of supplying the inrush current, the supply amount of the lamp current is stopped, and then the inrush current is supplied after a predetermined time has elapsed , How to turn on the high-pressure discharge lamp.   The lighting method of the high-pressure discharge lamp according to any one of claims 1 to 3, wherein the supply time of the initial current is 1 to 20 minutes. The lighting method of the high-pressure discharge lamp according to any one of claims 1 to 4, wherein a period from the start of the rising current supply to the start of supply of the stable current is 13 to 70 minutes.

Images