JP2008293934A - High pressure discharge lamp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure discharge lamp which prevents bending of an electrode portion of the high pressure discharge lamp and has a long lamp life. <P>SOLUTION: The high pressure discharge lamp apparatus is provided with a high pressure discharge lamp 1 in which mercury of 0.20/mm3 or more and halogen in a range of 10<SP>-6</SP>μmol/mm<SP>3</SP>to 10<SP>-2</SP>μmol/mm<SP>3</SP>are sealed and a pair of electrodes are arranged facing each other in a distance of 2.0 mm or less and a power supplying unit 8 for supplying an AC current to the high pressure discharge lamp 1. An electrode of the high pressure discharge lamp 1 is made of high purity tungsten of a purity 5N(99.999%) or higher and the power supplying unit 8 has a small power mode for supplying a lower power than a rated power, and the high pressure discharge lamp 1 is switched off after the lamp is lit in the small power mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a high-pressure discharge lamp device, and more particularly to a high-pressure discharge lamp device using a high-pressure discharge lamp in which mercury is enclosed in an amount of 0.2 mg / mm ³ or more and the lighting pressure is 200 atmospheres or more.

  In general, there are a projector apparatus using a liquid crystal panel and a DLP system. There are 1 type and 3 type using the liquid crystal panel, but in either method, the radiated light from the light source is separated into 3 colors (RGB) to correspond to the image information in the liquid crystal panel The light is transmitted and adjusted, and then the three colors transmitted through the liquid crystal panel are combined and projected onto the screen.

On the other hand, the method using DLP is a spatial modulation element (also referred to as a light modulation device, specifically a DMD element, etc.) through a rotary filter in which radiated light from a light source is divided into three color (RGB) regions. ) Etc. in a time-sharing manner, and this DMD element reflects specific light to irradiate the screen. A DMD element is a device in which millions of small mirrors are laid out for each pixel, and light projection is controlled by controlling the direction of each small mirror. Compared with the liquid crystal system, the DLP system has a merit that the entire system is small and simple because the optical system is simple and it is not necessary to use three liquid crystal panels.
Japanese Patent No. 2829339

  Generally, a lamp unit in which a high-pressure discharge lamp having a high mercury vapor pressure is attached to a concave reflecting mirror is used as a light source of a projector apparatus. This is because by increasing the mercury vapor pressure, light in the visible wavelength region can be obtained with high output. In addition, the light source of the projector device is required to have a high light output as described above, and is also required to have a dimming function that adjusts the screen illuminance according to the environment and situation in which the image is projected. In response to this requirement, the emitted light from the lamp unit can be dimmed using a dimming means, but the intensity of the emitted light from the light source itself is adjusted in consideration of the demand for miniaturization of the projector device. Therefore, there is a demand for a method of dimming in the most realistic sense. For example, for bright rooms and large screens, the power applied to the high-pressure discharge lamp is increased to increase the radiation intensity of the high-pressure discharge lamps. For relatively dark rooms and small screens, the high-pressure discharge lamps are charged. It is to use with lower power.

  In addition, reducing the input power to the high-pressure discharge lamp has the effect of extending the life of the high-pressure discharge lamp and also has the effect of saving power consumption. Therefore, such lighting that reduces the input power is called an eco mode. In this application, a mode used in a state where power is reduced including this eco mode will be referred to as a “low power mode”.

  Furthermore, in recent years, the demand for longer life of high-pressure discharge lamps has been increasing further from the projector market. For this reason, there is a demand for higher purity of the material in the lamp discharge space. Of 5N (99.999%) tungsten must be used. However, it is known that tungsten is easily recrystallized and the grain size is likely to become coarser as the use temperature is increased and the purity of the material is increased. At the same time, the continuity of defects previously possessed at the grain boundaries is increased, and the strength of the crystal grain boundaries and the strength is in a contradictory relationship, so there is a problem that the strength of the high-purity material is lower than that of the conventional material. .

  On the other hand, high-pressure discharge lamps for projectors are mainly AC high-pressure discharge lamps, and there is a problem that the temperature of the electrodes is higher than that of direct-current high-pressure discharge lamps. The reason why the electrode temperature of AC high-pressure discharge lamps is high is that each pair of electrodes must also serve as a cathode that emits thermoelectrons, so each electrode is extremely large like a DC high-pressure discharge lamp. This is because it is not possible to secure a sufficient heat capacity that can withstand operation as an anode.

  Furthermore, along with the downsizing of the light source and the increase in the amount of light, high pressure discharge lamps are required to be designed to withstand high power and high operating pressure, increasing the heat capacity of the electrode head and reducing the electrode core rod diameter of the sealing part. Has been promoted. However, this reveals a weight imbalance between the electrode head and the core rod diameter, increases the moment of the electrode at the quartz opening, and loses the concentric uniform contact of the electrode core rod with the quartz glass inner wall, There is a problem that stress between tungsten and quartz glass at the time of heat shrinkage becomes large. In the projector market, the number of uses for education and the like is increasing, and therefore, the usage mode in which the light source frequently blinks is increasing, and an electrode having high blinking resistance is required.

When such a high-pressure discharge lamp for alternating current is used and the lamp is repeatedly turned on and off with rated power, the electrode shaft of the high-pressure discharge lamp bends, and as a result, the position of the discharge arc deviates from the optical axis of the concave mirror. A problem arises in that the light output from the lamp unit decreases.
FIG. 13 is a partial front view of the high-pressure discharge lamp in which the electrode shaft portion is bent.
Here, the bending of the electrode shaft portion means that, as shown in the figure, a pair of electrodes 101 and 102 disposed inside the high-pressure discharge lamp 100 are exposed to an opening portion 103 of quartz glass exposed in the discharge space, In the vicinity of 104, the center of the electrode heads 105 and 106 is bent so as to be separated from the longitudinal axis of the electrode core rods 109 and 110 embedded in the sealing portions 107 and 108. The bending of the electrode shaft, that is, the separation distance of the center position of the electrode heads 105 and 106 with respect to the longitudinal axis of the electrode core rods 107 and 108 is, for example, from the center position of the electrode heads 105 and 106 In a high-pressure discharge lamp with a distance of 5 mm from the openings 103 and 104, the distance reaches 1.5 mm or more, which is a serious problem corresponding to the life failure level of the product.

  An object of the present invention is to provide a high-pressure discharge lamp device that solves the bending of the electrode shaft portion of the high-pressure discharge lamp and has a long lamp life.

The present invention employs the following means in order to solve the above problems.
The first means is that mercury of 0.20 mg / mm ³ or more and halogen in the range of 10 ⁻⁶ μmol / mm ³ to 10 ⁻² μmol / mm ³ are enclosed, and the pair of electrodes are spaced at intervals of 2.0 mm or less. In the high-pressure discharge lamp device comprising a high-pressure discharge lamp disposed opposite to the high-pressure discharge lamp and a power supply device that supplies AC power to the high-pressure discharge lamp, the electrode of the high-pressure discharge lamp has a purity of 5N (99.999%). Made of the above high purity tungsten, the power supply device has a low power mode for supplying power lower than rated power, and when the high pressure discharge lamp is turned off, the high pressure discharge lamp is turned on in the low power mode. A high-pressure discharge lamp device that is extinguished.
A second means is the high-pressure discharge according to the first means, wherein the low power mode is such that the lamp lighting power is 55% or more and 90% or less of the rated power and the period is one second or more. It is a lamp device.
The third means is the first means, wherein the low power mode is such that the lamp lighting power decreases at a rate of 55% or less of the rated power per second and the period is 1 second or more and 55% or more of the rated power. A high-pressure discharge lamp device that passes through a range of 90% or less.

  According to the high-pressure discharge lamp device of the present invention, even in a high-pressure discharge lamp using high-purity tungsten having a purity of 5N (99.999%) or more as an electrode material, it is lit in the low-power mode at least for a certain time immediately before turning off. Thereby, generation | occurrence | production of the bending of an electrode shaft part can be prevented.

  As a result of intensive studies, the present inventors have found that bending of the electrode shaft portion is caused by a rapid temperature change (temperature decrease) of the electrode shaft portion when the high-pressure discharge lamp is extinguished. . The relationship between the rapid temperature change of the electrode shaft portion and the bending will be described later. Here, the experimental results leading to the investigation of the bending of the electrode shaft portion will be described.

In order to find out the cause of the phenomenon of bending of the electrode shaft portion, a high-pressure discharge lamp with a rated power of 200 W was lit for 600 hours for 10 lamps in the following four modes, respectively, and then the presence or absence of bending of the electrode shaft portion was observed.
FIG. 1 to FIG. 4 are diagrams showing lighting modes A to D which were used for experiments, respectively.
FIG. 1 (lighting mode A) is a lighting mode in which a cycle of turning off for 30 minutes after lighting for 2 hours at a rated power of 200 W was repeated. FIG. 2 (lighting mode B) is a lighting mode of continuous lighting at a rating of 200W. FIG. 3 (lighting mode C) is a lighting mode in which the lamp lighting power is a low power of 160 W and the cycle of turning off for 30 minutes is repeated after lighting for 2 hours. FIG. 4 (lighting mode D) is a lighting mode in which a cycle of turning off for 30 minutes is repeated after lighting for 2 hours at a rated power of 200 W, and the lamp lighting power is turned off after lighting in the low power mode of 160 W for 2 seconds when turned off.
Here, since the first about 1 minute in the low power (160 W) lighting in FIG. 3 (lighting mode C) is turned on at the rated power (200 W), the initial lighting conditions are the same as those in FIG. 1 (lighting mode A). FIG. 2 (lighting mode B) and FIG. 4 (lighting mode D) are the same.

  Regarding the above-mentioned four lighting modes A to D, the bending of the electrode shaft portion was observed. As a result of observation, the electrode shaft portion was bent in the lighting mode of the rated lighting / extinguishing cycle of FIG. 1 (lighting mode A). Further, in the lighting mode of rated lighting / continuous lighting shown in FIG. 2 (lighting mode B), the electrode shaft portion was not bent. Therefore, comparing FIG. 1 (lighting mode A) and FIG. 2 (lighting mode B), it can be said that a problem is caused in the process of blinking of the high-pressure discharge lamp, that is, starting and extinguishing. Further, in the lighting mode of the low power lighting / extinguishing cycle in FIG. 3 (lighting mode C), the electrode shaft portion was not bent. Therefore, when FIG. 1 (lighting mode A) is compared with FIG. 3 (lighting mode C), it can be said that the power at the time of stable lighting or immediately before extinguishing affects the presence or absence of bending of the electrode shaft portion. Further, in the lighting mode in which the rated power lighting / extinguishing cycle shown in FIG. 4 (lighting mode D) is turned off after the small power is turned on for a certain period immediately before the light is turned off, the electrode shaft portion is not bent. Therefore, when FIG. 1 (lighting mode A), FIG. 3 (lighting mode C), and FIG. 4 (lighting mode D) are compared, the input power immediately before turning off and the behavior at the time of turning off influence the presence or absence of bending of the electrode shaft. It can be said that it has given.

  More specifically, in the case of FIG. 1 (lighting mode A), bending of the electrode shaft portion occurred in 5 out of 10 high-pressure discharge lamps, but FIG. 2 (lighting mode B) to FIG. 4 (lighting mode D). In the three lighting modes, no bending of the electrode axis was observed. From these results, it was found that the bending of the electrode shaft portion occurred in the process of extinguishing and was dependent on the condition at the time of extinguishing. This is because, in comparison between FIG. 1 (lighting mode A) and FIG. 2 (lighting mode B), the electrode shaft portion is not bent in FIG. Moreover, it is because it turns out from the comparison of FIG. 3 (lighting mode C) and FIG. 4 (lighting mode D) that the bending of an electrode shaft part does not depend on lamp lighting power, but depends on the conditions just before a light extinction. Furthermore, as described above, the initial lighting conditions including those in FIG. 3 (lighting mode C) are the same in the four lighting modes, so it can be seen that the conditions in the starting process are not related to the bending of the electrode shaft portion.

  From the above experimental results, it can be seen that bending of the electrode shaft portion does not occur if the light is turned on in the low power mode for a certain period immediately before turning off.

FIG. 5 is a table showing the rate (%) of bending of the electrode shaft portion obtained as a result of the experiment conducted to determine the condition of the lighting mode D in FIG. Here, it was determined that the electrode shaft was bent as follows: “The experiment was conducted with a high-pressure discharge lamp whose distance from the center position of the electrode head to the opening of the quartz glass was 5 mm, and the electrode at the center position of the electrode head The separation distance with respect to the longitudinal direction of the shaft portion exceeds 1.5 mm ”.
In the table, the left column shows the small power W1 immediately before turning off by the ratio k (%) to the rated power W0, and the upper column shows the shift period T (seconds) from the small power W1 immediately before turning off to the turning off. Is shown. The number of high-pressure discharge lamps with a rated power of 200 W used in this experiment is 10, and the number of repetitions of lighting 30 minutes / lighting off 30 minutes is 250 times, both of which have the same power load from the start to the stable time. did.
As is clear from these experimental results, the occurrence rate of bending of the electrode shaft portion reaches 50% when the low power immediately before the light is turned off is the rated power and the light is turned on / off repeatedly in the shift period of 0 seconds. On the other hand, the bending rate of the electrode shaft portion is 0% when the light is turned on / off repeatedly within a range of 90% to 55% of the rated power before turning off and the shift period is 1 second or longer.

FIG. 6 is a graphical representation of the table shown in FIG.
According to the experimental results obtained in the table of FIG. 5, the power is instantaneously lowered from the rated power to 55% of the rated power and held for 1 second, and then the electrode shaft is bent by turning off the high-pressure discharge lamp. As shown in FIG. 6, the lamp lighting power is reduced at a rate of 55% or less / second, and the lamp lighting power is 55% or more and 90% after 1 second or more, as shown in FIG. The same effect can be obtained when the lamp is turned off after being lowered to below. That is, the same effect can be obtained also in the low power mode in which the lamp operating power passes through the range surrounded by the rated power of 90% to 55% and 1 second or more in FIG. In other words, if the lamp lighting power changes to extinguishing, if it passes through this range, it is not only a two-stage power change, but also a three-stage power change or a continuous power change. The same effect can be obtained.

FIG. 7 is a view showing a high-pressure discharge lamp 1 used in the high-pressure discharge lamp apparatus of the present invention.
As shown in the figure, the high-pressure discharge lamp 1 has a substantially spherical light emitting portion 2 formed by a discharge vessel made of quartz glass. In the light emitting unit 2, a pair of electrodes 4 are arranged to face each other with an interval of 2 mm or less. Further, sealing portions 3 are formed at both ends of the light emitting portion 2. A conductive metal foil 5 made of molybdenum is embedded in the sealing portion 3 in an airtight manner, for example, by a shrink seal. The shaft portion 41 of the electrode 4 is joined to one end of the metal foil 5, and the external lead 6 is joined to the other end of the metal foil 5 to supply power from an external power supply device (not shown).

The light emitting unit 2 is filled with mercury, rare gas, and halogen gas. Mercury is used to obtain a required visible light wavelength, for example, radiation having a wavelength of 360 to 780 nm, and is enclosed in an amount of 0.2 mg / mm ³ or more. Although the amount of sealing varies depending on the temperature condition, the vapor pressure becomes extremely high at 200 atm or more at the time of lighting. In addition, by enclosing more mercury, a high-pressure discharge lamp with a high mercury vapor pressure of 250 atm or more and 300 atm or more can be produced when the lamp is turned on. The higher the mercury vapor pressure, the more suitable the light source for the projector device. Can be realized.

As the rare gas, for example, argon gas is sealed at about 13 kPa. Its function is to improve the lighting startability. As for halogen, iodine, bromine, chlorine and the like are enclosed in the form of mercury or other metal and a compound. The amount of halogen encapsulated is selected from the range of 10 ⁻⁶ μmol / mm ³ to 10 ⁻² μmol / mm ³ . The function of the halogen is to extend the life using a so-called halogen cycle. However, the high pressure discharge lamp 1 such as the high pressure discharge lamp 1 of this embodiment has an action of preventing devitrification of the discharge vessel. is there.

A numerical example of the high-pressure discharge lamp 1 to which the present invention is applied is, for example, the maximum outer diameter of the light emitting part 2 is 9.5 mm, the distance between the electrodes is 1.0 mm, the arc tube inner volume is 75 mm ³ , the rated voltage is 70V, AC lighting is performed with electric power of 200W. In addition, this type of high-pressure discharge lamp 1 is built in a projector apparatus to be reduced in size, and requires a large amount of light emission while requiring an extremely small overall size. For this reason, the thermal influence in the light emission part 2 becomes very severe. The lamp wall load value of the lamp is 0.8 to 2.0 W / mm ² , specifically 1.5 W / mm ² . When such a high-pressure discharge lamp 1 having a high mercury vapor pressure and a tube wall load value is mounted on a presentation device such as a projector device or an overhead projector, light with good color rendering properties can be emitted. In addition, if the tube wall load value of the lamp is in the range of 0.8 to 2.0 W / mm ² , a high pressure discharge lamp of 200 W or more or 200 W or less can be used.

FIG. 8 is an enlarged view of the electrode 4 shown in FIG.
As shown in the figure, each of the pair of electrodes 4 includes a block portion 41 and a shaft portion 42. The lump portion 41 may be formed by winding a tungsten wire in a coil shape around the shaft portion 42 and melting it. Alternatively, the lump portion 41 and the shaft portion 42 may be formed by cutting a tungsten rod having a diameter of the lump portion 41. It may be formed. In the high-pressure discharge lamp 1 used in this embodiment, the distance between the electrodes is as short as 2 mm or less, and the thermal load on the electrode tip is large, so that the tip portion has a block 41 and a high pressure of 200 atm or more. It is necessary to make the shaft portion 42 thinner in order to form the sealing portion 3 that can withstand this. As an example, the diameter of the massive portion 41 of the high-pressure discharge lamp 1 of the 200 W lamp is 1.5 mm, and the diameter of the shaft portion 42 is 0.4 mm. The structure of the electrode 4 with the large lump portion 41 at the tip end portion and the thin shaft portion 42 is one factor that tends to cause the shaft portion 42 to be bent.

FIG. 9 is a diagram illustrating a part of the high-pressure discharge lamp 1 in which the electrode shaft portion 42 has been bent in the previous experiment.
In the same figure, 7 is the deposit which generate | occur | produced with lighting. Such deposits 7 were also found in the high-pressure discharge lamp 1 in which the electrode shaft portion 42 did not bend. Therefore, the electrode shaft portion 42 was bent only by the generation of the deposit 7. is not. In addition, as a result of analyzing such a deposit 7, it was a compound containing silicon. Therefore, it is considered that it was transported and deposited by the chemical action between the enclosed halogen and the discharge vessel. Regarding the bending of the electrode shaft portion 42, the distance from the center of the tip of the lump portion 41 to the opening 21 of the light emitting portion 2 is about 5 mm.

Next, in view of the previous experimental results and observation results of deposits and the like, the bending mechanism of the electrode shaft portion 42 will be considered.
As shown in FIG. 9, the electrode shaft portion 42 is bent in the opposite direction (downward in FIG. 9) with respect to the position of the deposit 7 (upper side of the electrode shaft portion 42 in FIG. 9). From this fact and the fact that the bending of the electrode shaft portion found by the previous experiment occurs in the extinguishing process, it is considered that the bending of the electrode shaft portion is generated by the following mechanism.

  That is, the electrode shaft portion 42 contracts as the temperature of the electrode 4 decreases after the light is extinguished, but the contraction of the shaft side surface (upper side in FIG. 9) where the deposit 7 is present is hindered by the deposit 7. It is thought that it will bend toward the unhindered (downward in FIG. 9). In other words, it can be said that the electrode shaft portion 42 is deformed due to the difference in thermal shrinkage. Here, when the high-pressure discharge lamp 1 is turned off from the rated power on, rapid deformation of the electrode shaft portion 42 occurs due to the difference in thermal contraction, and the inertial motion (downward motion in FIG. 9) of the heavy tip lump portion 41 occurs. This induces a large deformation of the electrode shaft portion 42. It is considered that when this deformation exceeds the elastic limit of the tungsten material and plastic deformation occurs, the deformation accumulates each time the light is extinguished and the electrode shaft portion 42 is bent.

  As described above, considering the mechanism in which the thermal contraction due to the temperature change causes the stress of the electrode shaft portion 42, if the change in the absolute value of the temperature is made smaller, it is natural that the stress is alleviated. In consideration of the fact that it is necessary for the effect of suppressing the bending of the electrode shaft part to reduce the lamp lighting power for a certain period of time before the lamp is turned off, as shown in the experimental results shown in FIG. In order to prevent this, both elements of limiting the temperature change width and securing the holding time are necessary, and it can be said that it is effective to moderate the temperature change / time.

  In view of the above points, when turning off from low power lighting, the temperature of the electrode shaft portion 42 at the time of lighting is relatively low, and the difference in heat shrinkage is also relatively small, so that the electrode shaft portion 42 is bent. The rapid deformation of does not occur. Further, when the low power is turned on for a certain time from the rated lighting, the light is turned off in the same manner as the case where the low power is turned off from the point of temperature decrease of the electrode shaft 42 in the light turning off process. Bending is prevented as well.

  The fixed time is preferably 1 second or longer. In the case of less than this, even if switching from the rated lighting to the low power lighting, since the light is turned off before the temperature of the electrode shaft portion 42 is sufficiently lowered, the effect of preventing the electrode shaft portion 42 from being bent is small. The lamp lighting power in the low power mode is preferably 55% or more and 90% or less of the rated power. When it is larger than 90%, the temperature of the electrode shaft portion 42 is not so different from that when the rated power is turned on, and when it is smaller than 55%, the temperature change of the electrode shaft portion 42 is too large.

  In addition, as described above, in the process of turning off the lamp, the lamp lighting power is not switched to the low power mode at a time, but slowly at a rate of 55% or less of the rated power per second for 1 second or more. The same effect can be obtained even if the lamp is turned off after the lamp lighting power is reduced to 55% or more and 90% or less. This is because the temperature of the electrode shaft portion 42 follows the decrease in the lamp lighting power if the lamp lighting power is gradually lowered in this way.

FIG. 10 is a diagram illustrating a circuit configuration of a power feeding device 8 that supplies AC power to the high-pressure discharge lamp 1.
As shown in the figure, the power feeding device 8 is connected to a step-down chopper circuit 9 to which a DC voltage is supplied, and is connected to the output side of the step-down chopper circuit 9 to change the DC voltage to an AC voltage and supply it to the high-pressure discharge lamp 1. A full-bridge inverter circuit 10 (hereinafter also referred to as “full-bridge circuit”), a coil L 1 connected in series to the high-pressure discharge lamp 1, a capacitor C 1, and a starter circuit 11. The step-down chopper circuit 9, the full bridge circuit 10, and the starter circuit 11 constitute a power supply device 8, which includes the high-pressure discharge lamp 1 and is called a high-pressure discharge lamp device.

The step-down chopper circuit 9 is connected to a DC power supply _VDC (not shown), and includes a switching element Qx, a diode Dx, a coil Lx, a smoothing capacitor Cx, and a driving circuit Gx for the switching element Qx. The switching element Qx is turned on / off by the drive circuit Gx. By this driving, the duty ratio of the switching element Qx is adjusted, and the current or power supplied to the high-pressure discharge lamp 1 is controlled. That is, the control circuit 12 feedback-controls the switching element Qx via the drive circuit Gx based on the voltage signal Sv detected by the resistors R1 and R2, the current signal Si detected by R3 and the power signal Sw from the outside. . Thus, constant power control is performed in which the lamp lighting power of the high-pressure discharge lamp 1 is set to a constant value.

  The full bridge circuit 10 includes switching elements Q1 to Q4 such as transistors and FETs connected in a bridge shape, and driving circuits G1 to G4 for the switching elements Q1 to Q4. Note that a diode may be connected in antiparallel to each of the switching elements Q1 to Q4, but the diode is omitted in this embodiment. The switching elements Q1 to Q4 are driven by drive circuits G1 to G4 via a control unit (not shown). The operation of the full bridge circuit 10 is performed by alternately switching on and off the switching elements Q1 and Q4 and the switching elements Q2 and Q3. When the switching elements Q1 and Q4 are turned on, a current flows through the step-down chopper circuit 9 → the switching element Q1 → the coil L1 → the high-pressure discharge lamp 1 → the switching element Q4 → the step-down chopper circuit 9. On the other hand, when the switching elements Q2 and Q3 are turned on, an AC rectangular wave current is applied to the discharge lamp 1 through the path of the step-down chopper circuit 9 → the switching element Q3 → the high-pressure discharge lamp 1 → the coil L1 → the switching element Q2 → the step-down chopper circuit 9. Supply.

  The starter circuit 11 includes a switch element Q5, a drive circuit G5, a resistor R1, a capacitor C2, and a transformer T2. The energy stored in the capacitor C2 at the time of starting the high-pressure discharge lamp 1 is applied to the transformer T2 by turning on the switch element Q5 to increase the voltage, and a high voltage is applied to the high-pressure discharge lamp 1 to start the high-pressure discharge lamp 1. Here, a so-called external trigger method in which a high voltage applying conductor is piped on the outer surface of the high pressure discharge lamp 1 is shown.

FIG. 11 is a diagram showing an internal configuration of the control circuit 12 shown in FIG.
The constant power control will be described with reference to FIGS. 10 and 11. The lamp voltage signal Sv and the power signal Sw from the signal generator 13 are input to the control circuit 12 to the arithmetic circuit 121 to calculate the reference current value. This reference current value is input to the comparator 122 as a signal Si-ref. The current signal Si is input to the other terminal of the comparator 122. The comparator 122 compares the reference current signal Si-ref with the current signal Si, and the pulse width control circuit ( PWM) 123 and the switching element Qx are controlled via the drive circuit Gx. In this way, the lamp lighting power of the high-pressure discharge lamp 1 is kept at the power corresponding to the power signal Sw.

Next, the operation in the process from turning on and off the constant-power 200 W rated high-pressure discharge lamp 1 will be described.
When the high-pressure discharge lamp 1 is turned on, when a lighting signal Ss is supplied from the outside of the power supply device 8 to the signal generator 13, a power signal Sw corresponding to the lighting power 200 W is input from the signal generator 13 to the control circuit 12. The discharge lamp 1 is lighted at a constant power with a rated power of 200 W. In order to turn off the high-pressure discharge lamp 1, first, when a turn-off signal Ss is given to the signal generator 13 from the outside of the power supply device 8, the power signal generator 131 generates a power signal Ss of, for example, 160 W (80% of the rated power). ) And is output to the control circuit 12 as a power signal Sw corresponding to the low power mode. As a result, the high-pressure discharge lamp 1 is lit at a power 160W lower than the rated power. After a predetermined time elapses after the power signal Ss is changed to the signal corresponding to the low power mode, for example, 2 seconds later, the turn-off signal Ss is delayed by the delay circuit 132 of the signal generator 13 for a predetermined time and is sent to the control circuit 12. Entered. When the extinction signal Ss is input to the control circuit 12, the pulse width control circuit (PWM) 123 stops the drive circuit Gx, the switching element Qx is fixed to OFF, and the supply of current to the high-pressure discharge lamp 1 is stopped. Turns off when In this way, the high-pressure discharge lamp 1 is turned off a predetermined time after the lamp lighting power of the high-pressure discharge lamp 1 is changed to the low power mode.

  The above control mode is shown in FIG. FIG. 12 (a) shows a case where the lamp lighting power is lowered stepwise. Instead, as shown in FIG. 12 (b), the lamp lighting power is reduced to a substantially linear shape and then turned off. Good.

  In the power supply device 8 described above, a configuration in which the light-off signal Ss is supplied to the power supply device 8 from the outside is shown. However, both the power signal Sw and the light-off signal Ss are externally supplied from the power supply device 8 in FIG. It is good also as a structure given with a temporal relationship as shown in (b). In that case, the signal generator 13 may be omitted, and the power signal Sw and the turn-off signal Ss may be directly input to the control circuit 12.

FIG. 2 is a diagram showing a lighting mode A of the high-pressure discharge lamp 1. It is a figure which shows the lighting mode B of the high pressure discharge lamp. It is a figure which shows the lighting mode C of the high pressure discharge lamp. It is a figure which shows the lighting mode D of the high pressure discharge lamp. 5 is a table showing the rate of occurrence (%) of bending of the electrode shaft portion obtained as a result of an experiment conducted to determine the conditions of the lighting mode D shown in FIG. 4. FIG. 6 is a diagram showing the table shown in FIG. 5 as a graphic. It is a figure which shows the high pressure discharge lamp 1 used for the high pressure discharge lamp apparatus of this invention. It is an enlarged view of the electrode 4 shown in FIG. It is a figure which shows a part of high-pressure discharge lamp in which the bending of the electrode shaft part 42 generate | occur | produced. 2 is a diagram illustrating a circuit configuration of a power feeding device 8 that supplies AC power to a high-pressure discharge lamp 1. FIG. It is a figure which shows the internal structure of the control circuit 12 shown in FIG. It is a figure which shows the control aspect at the time of extinguishing of the high pressure discharge lamp. It is a partial front view of the high pressure discharge lamp 100 in which the electrode shaft portion is bent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure discharge lamp 2 Light emission part 21 Opening part 3 Sealing part 4 Electrode 41 Lump part 42 Shaft part 5 Conductive metal foil 6 External lead 7 Deposit 8 Feeding device 9 Step-down chopper circuit 10 Full bridge type inverter circuit (full bridge circuit) )
11 Starter circuit 12 Control circuit 121 Operation unit 122 Comparator 123 Pulse width control circuit (PWM)
13 Signal Generator 131 Power Signal Generator 132 Delay Circuit

Claims (3)

0.20 mg / mm ³ or more of mercury and 10 ⁻⁶ μmol / mm ³ to 10 ⁻² μmol / mm ³ of halogen are enclosed, and a pair of electrodes are arranged to face each other at intervals of 2.0 mm or less In a high-pressure discharge lamp device composed of a lamp and a power supply device that supplies AC power to the high-pressure discharge lamp,
The electrode of the high-pressure discharge lamp is made of high-purity tungsten having a purity of 5N (99.999%) or higher, and the power feeding device has a low power mode for supplying power lower than rated power, The high pressure discharge lamp device is characterized in that when the light is turned off, the high pressure discharge lamp is turned on after being turned on in the low power mode.   2. The high-pressure discharge lamp device according to claim 1, wherein in the low power mode, the lamp lighting power is 55% or more and 90% or less of the rated power, and the period is 1 second or more. The low power mode is characterized in that the lamp lighting power decreases at a rate of 55% or less of the rated power per second and passes through a range of 55% or more and 90% or less of the rated power in a period of 1 second or more. The high pressure discharge lamp device according to claim 1.

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