JP2007258085A - Short-arc mercury lamp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a short-arc mercury lamp device which reduces heat distortion generated at flash-up lighting to prevent breakage of an airtight container. <P>SOLUTION: The short-arc mercury lamp device includes a short-arc mercury lamp SHL and a lighting circuit OC. The lamp SHL includes the ultraviolet transmissive airtight container 1 equipped with an envelope part 1a and a pair of sealing parts 1b; a cathode 2K whose basal end is connected with a sealed metal foil 1c and whose tip end is protruded in the envelope part; an anode 2A whose basal end is connected with a sealed metal foil 1c and whose tip end is protruded in the envelope part and separately opposed to the cathode with a small gap therefrom; discharge media containing mercury and a rare gas; and a thermal insulation film formed on the outer surface of portions, whose temperature is low during lighting, of the airtight container. The circuit OC lights the lamp by a relatively low first lamp power during the ordinary lighting time, and lights the lamp by a relatively high lamp power, in which a second lamp power is added to the first lamp power, during the intermittent enhanced lighting time. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a short arc type mercury lamp device suitable as a light source device for an ultraviolet irradiation device.

  An ultraviolet light permeable hermetic container having an encircling part surrounding the discharge space and a pair of sealing parts extending from both ends of the encircling part; and being sealed in the hermetic container and projecting into the enveloping part along the tube axis direction A short arc type mercury lamp is known which includes a cathode and an anode which are spaced apart from each other at a small interval, and a discharge medium containing mercury and a rare gas sealed in the hermetic container (see, for example, Patent Document 1). This type of short arc mercury lamp is mainly used as a light source of an ultraviolet irradiation device. In order to improve the performance of the ultraviolet irradiation device, it is necessary to improve the lamp characteristics and reliability of this type of light source.

Japanese Patent Laid-Open No. 07-226187

  When the above short arc mercury lamp is normally lit, it is lit with relatively low lamp power. When the second lamp power is intermittently added to the first lamp power and lit with relatively large lamp power, Brightening lighting (hereinafter referred to as “flash-up lighting” for convenience) in which the ultraviolet illuminance increases instantaneously can be performed, and the ultraviolet irradiation ability is increased as compared with the case where lighting is continuously performed with a constant lamp power.

  Then, since the UV illuminance increases when the flash is turned on, synchronize the workpiece index so that the workpiece is irradiated with ultraviolet rays, or synchronize the workpiece index and switch to flash-up lighting. Thus, irradiation with high ultraviolet illuminance can be performed. For this reason, since the enlargement of the short arc type mercury lamp and the lighting circuit can be suppressed, the cost can be reduced.

  However, it has been found that conventional short arc mercury lamps do not have a structure suitable for performing flash-up lighting. That is, since the first lamp power is generally small enough to maintain arc discharge, the first lamp power is continuously set to a smaller value than the case of a constant rated lamp power. Further, the second lamp power at the time of flash-up is set to a value larger than the rated lamp power. For this reason, the electrode temperature at the time of flash-up lighting rises, the thermal distortion of the hermetic container increases, and the hermetic container is easily damaged.

  It is an object of the present invention to provide a short arc type mercury lamp apparatus that reduces thermal distortion generated during flash-up lighting and prevents damage to an airtight container.

  The short arc type mercury lamp apparatus of the present invention includes an enclosing portion that forms a discharge space therein and a pair of sealing portions that extend integrally from both ends of the enclosing portion and in which a sealing metal foil is hermetically embedded. An ultraviolet-permeable hermetic container having a base end connected to a sealing metal foil embedded in the sealing part of the hermetic container, a tip protruding into the enclosure, and a base end of the hermetic container An anode connected to a sealing metal foil embedded in the sealing portion and having a tip projecting into the surrounding portion and facing the cathode at a small interval, a discharge medium containing mercury and a rare gas sealed in the hermetic vessel, And a short arc type mercury lamp provided with a heat insulating film formed on the outer surface of the part that becomes low temperature during lighting of the airtight container; and the short arc type mercury lamp is lit with a relatively small first lamp power during normal lighting. Leave it intermittent It is characterized in that comprises a; a lighting circuit for lighting the second lamp power a relatively large lamp power added to the first lamp power during lighting.

  According to the present invention, by flashing up a short arc type mercury lamp provided with a heat insulating film formed on the outer surface of a portion that becomes low temperature during lighting of the hermetic container, thermal distortion of the hermetic container that occurs at the time of flashing up lighting is achieved. It is possible to provide a short arc type mercury lamp device that is reduced to prevent damage to the hermetic container.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1 to 4 show a first embodiment for carrying out the short arc type mercury lamp apparatus of the present invention, FIG. 1 is a front view of the entire short arc type mercury lamp apparatus, and FIG. 2 is an enlarged view of a cathode. FIG. 3 is an enlarged front view and side view showing the anode, and FIG. 4 is a waveform diagram of lamp power for explaining the flash-up lighting.

  The short arc type mercury lamp apparatus of the present invention includes a short arc type mercury lamp SHL and a lighting circuit OC.

  First, the short arc type mercury lamp SHL will be described. The short arc type mercury lamp SHL is of a direct current lighting type including an airtight container 1, a cathode 2K, an anode 2A, a discharge medium, external lead conductors 3 and 4, and heat insulating films 5 and 6.

  The hermetic container 1 has at least a main part that is UV transmissive and is made of, for example, quartz glass. And the surrounding part 1a and the pair of sealing parts 1b and 1b are provided. A discharge space is formed in the enclosure 1a.

  The surrounding portion 1a is allowed to have an appropriate shape, but has, for example, a spindle shape that is long in the tube axis direction. Further, an exhaust tip off portion Ex is formed on a part of the side surface of the surrounding portion 1a. This exhaust tip-off portion Ex projects from the surrounding portion 1a to the outside in a umbilical shape, and is pre-welded when the short arc type mercury lamp SHL is manufactured in order to exhaust the inside of the surrounding portion 1a and enclose the discharge medium. It is formed after the exhaust pipe previously sealed is sealed.

  The pair of sealing portions 1b and 1b extend from both ends of the surrounding portion 1a in the tube axis direction in the tube axis direction, hermetically seal the hermetic container 1, and support a cathode 2K and an anode 2A described later. And it contributes to sealing in the discharge space 1c.

  More specifically, when the airtight container 1 is made of quartz glass, the sealing portion 1b has, for example, a sealing metal foil 1c embedded therein in an airtight manner. The sealing metal foil 1c is preferably made of molybdenum foil, and one or a plurality of, for example, two in a parallel state are welded to the base end portion of the electrode in order to obtain a required current capacity.

  The cathode 2K and the anode 2A are formed mainly of a refractory and conductive metal such as tungsten (W), rhenium (Re), or a tungsten-rhenium alloy. Further, the cathode 2K and the anode 2A are opposed to each other on the tube axis so that the distance between the electrodes is smaller than the inner diameter of the surrounding portion 1a, for example, 2 mm, so that a short arc type discharge occurs between the electrodes. Are arranged.

  As shown in FIGS. 2A and 2B, the cathode 2K includes a cathode main portion K1, an intermediate portion K2, a base end portion K3, and a coil portion Ck in this embodiment. The cathode main portion K1 has a relatively small diameter, as is well known, since the ion current flowing during the lamp operation is small. In order to stabilize the position of the cathode spot during stable lighting, the tip is tapered as is well known. The intermediate portion K2 is a shaft portion and integrally supports the cathode main portion K1 at the tip. The base end portion K3 is flatly ground and is easily welded to the sealing metal foil 1c.

  The coil portion Ck is a means added as desired, and is wound around the intermediate portion K2 at a position retracted by an appropriate distance from the tip of the cathode main portion K1. Then, it is formed of a fine wire of a refractory metal having electron emission properties, for example, thorium tungsten by doping an electron emission material. By providing this coil part Ck, it is possible to form a cathode spot on the coil part Ck only at the time of start-up and transfer to the end of the cathode main part K1 after an appropriate time delay. As a result, wear of the cathode 2K can be reduced. In addition, as a constituent metal of the cathode main part K1 and the coil part Ck, the said refractory metal doped with electron radioactive substances, such as a tria, an alumina, a magnesia, a zirconia, can be used, for example.

  On the other hand, as shown in FIGS. 3A and 3B, the anode 2A includes an anode main part A1, an intermediate part A2, and a base end part A3 in the case of this embodiment. The anode main portion A1 is configured to have a large diameter and a large surface area as is well known in the art in order to promote heat dissipation since the electron current flowing during the lamp operation is large. The intermediate portion A2 is a shaft portion, and integrally supports the anode main portion A1 at the tip. The base end A3 is ground flat and is easily welded to the sealing metal foil 1c.

  Further, the short arc type mercury discharge lamp SHL of the present invention is lit in a vertical state in which the cathode 2K is positioned on the upper side and the anode 2A is positioned on the lower side of the cathode 2B. In the case of this embodiment, in addition to the above configuration, in order to improve the balance of the temperature distribution of the hermetic container 1, the center P of the interelectrode distance G is on the anode 2A side from the center position of the length in the tube axis direction of the surrounding portion 1a. It is configured to be displaced within a predetermined distance range.

  The discharge medium is mainly composed of mercury and a rare gas. In addition, mercury exhibits an ultra-high pressure mercury vapor state that evaporates to, for example, several tens of atmospheres at the time of lighting. The rare gas is made of, for example, argon gas, and acts as a starting gas and a buffer gas.

  The external lead conductors 3 and 4 are connection means for receiving the power by connecting the cathode 2K and the anode 2A to the lighting circuit OC, and are connected to the cathode 2K and the anode 2A through the sealing metal foil 1c. Further, when the short arc mercury lamp SHL is mounted inside the ultraviolet irradiation device, the external lead structures 3 and 4 can be used as mounting means. In this case, the external lead structures 3 and 4 are not shown, but can adopt a base structure. The short arc type mercury lamp SHL can be mounted inside an embedded device such as an ultraviolet irradiation device by mounting the base structure portion on a lamp socket (not shown) placed at a predetermined position.

  The heat insulating film 5 is made of a coating film such as platinum or gold, and is formed on the outer surface of the hermetic container 1 so that the lower part of the hermetic container 1 in which the anode 2A is arranged as shown in FIG. More specifically, as shown in FIG. 1, the heat insulating film 5 is formed on the outer surface of the hermetic container 1 from the position facing the portion somewhat below the tip of the anode 2A to the upper portion of the lower sealing portion 1b. ing.

  The heat insulating film 6 is formed on the outer surface of the exhaust tip off portion Ex. The exhaust tip-off portion Ex projects from the surrounding portion 1a to the outside in a umbilical shape. For this reason, the exhaust tip-off portion is easily cooled and causes the temperature of the surrounding portion 1a to decrease, so the heat-retaining film 6 keeps the exhaust tip-off portion Ex warm. The heat insulating film 6 can be formed of a coating film such as platinum or gold.

  In addition to the basic structure described above, the short arc type mercury lamp SHL can be provided with a cathode heat insulating film (not shown) as desired. The cathode insulation film is a means for keeping the cathode 2K warm in order to prevent mercury from adhering to the cathode 2K. For example, it consists of a coating film such as platinum formed mainly on the outer surface of the sealing portion on the cathode 2K side. In addition, when mercury adheres to the cathode 2K, it becomes easy to cause an excessive start-up voltage and a lighting failure.

  Moreover, a trigger wire can be arrange | positioned if desired. The trigger wire is a means for increasing the potential gradient in the vicinity of the electrode at the time of starting to improve the startability of the short arc type mercury lamp SHL. For example, the base end is connected to the external lead assembly 3 on the cathode 2K side, the middle extends close to the outer surface of the surrounding portion 1a, and the tip is adjacent to the surrounding portion 1a of the sealing portion 1b on the anode 2A side. Wound around the site.

  Next, the lighting circuit OC will be described. The lighting circuit OC alternately and intermittently supplies the first lamp power Wa and the second lamp power Wb to the cathode 2K and the anode 2A of the short arc type mercury lamp SHL as shown in FIG. To do.

  The first lamp power Wa is normally supplied and is a relatively small value. For example, 700 W is assumed. The normal lighting is generally a standby time zone, and is a period for maintaining arc discharge during the standby time until ultraviolet irradiation is performed. In the present invention, the first lamp power Wa can be set within a range of 200 to 10,000 W.

  The second lamp power Wb is supplied in addition to the first lamp power Wa at the time of flash-up lighting. Therefore, the sum Wa + Wb of the first and second lamp power becomes a relatively large value. As an example, if the second lamp power Wb is 300 W, the sum Wa + Wb of the first and second lamp power is 1000 W. That is, the flash-up lighting is generally in the ultraviolet irradiation time zone, and is a period for performing high-power lighting in order to increase the ultraviolet output during the time of performing the ultraviolet irradiation work. In the present invention, the second lamp power Wb is smaller than the first lamp power Wa, and can be set within a range of 100 to 5000 W.

  Further, the ratio Wa / Wb between the first lamp power Wa and the second lamp power Wb, the time ratio T1 / T2 between the normal lighting time T1 and the flash-up lighting time T2, and the normal lighting time T1 and the flash-up lighting time T2 are: Although it depends on the application of ultraviolet irradiation and the mode of work, the following is a rough guide. The ratio Wa / Wb between the first lamp power Wa and the second lamp power Wb is generally in the range of 1.8 to 4.0, preferably in the range of 2.0 to 3.0. The time ratio T1 / T2 between the normal lighting time T1 and the flash-up lighting time T2 is not particularly limited in the present invention, but is generally 0.1 to 10, and preferably 0.15 to 7.0. The flash-up lighting time T2 is generally 0.1 second to 2 minutes, preferably 0.1 to 10 seconds. As an example, the normal lighting time T1 is 2 seconds and the flash-up lighting time T2 is 10 seconds. As another embodiment, both the normal lighting time T1 and the flash-up lighting time T2 are 2 seconds.

  Furthermore, as the circuit configuration of the lighting circuit OC, a known circuit configuration such as a constant power control type can be appropriately employed.

  Next, the operation of the short arc type mercury lamp apparatus of the present invention will be described. When the short arc mercury lamp SHL described above is lit, an ultrahigh pressure mercury vapor discharge is generated inside the light-transmitting hermetic vessel 1 to mainly generate ultraviolet rays having a wavelength of 365 nm.

  Further, the short arc mercury lamp SHL is intermittently flashed up by the lighting circuit OC as shown in FIG. That is, in the time zone in which the first lamp power Wa is supplied from the lighting circuit OC, the short arc type mercury lamp SHL is supplied with the first lamp power and the arc discharge is continued, but its light output is small. However, at this time, there is no problem if the light irradiation operation is not performed and a standby state is set. Next, when the lamp power supplied from the lighting circuit OC is switched, the second lamp power Wb is added to the first lamp power, and the increased lamp power Wa + Wb is supplied, the short arc type mercury lamp SHL instantaneously Shifts to brightening lighting. As a result, the ultraviolet output increases, which is convenient for performing the light irradiation operation.

  In the present invention, since the heat insulating films 5 and 6 are formed on the outer surface of the portion that becomes low temperature during lighting of the hermetic container 1 of the short arc type mercury lamp SHL, the temperature distribution of the hermetic container 1 is improved. Although heat distortion occurs when flashing up, it becomes relatively small and the hermetic container 1 is less likely to be damaged. For this reason, the short arc type mercury lamp SHL and the lighting circuit OC can be miniaturized by flash-up lighting, and a highly reliable short arc type mercury lamp apparatus can be obtained.

  Hereinafter, other embodiments for carrying out the present invention will be described.

The second embodiment for implementing the short arc type mercury lamp apparatus of the present invention is as follows. That is, in the short arc type mercury lamp SHL of the second mode, in addition to the configuration in the first mode, the length of the portion extending from the sealing metal foil 1c of the cathode 2K as shown in FIG. (Mm), the length of the portion extending from the sealing metal foil 1c of the anode 2A is D2 (mm), the first lamp power during normal lighting is Wa (W), and is added during flash-up lighting. When the second power is Wb (W),
Formula 1: Wa / 60 <D1 <(Wa + Wb) / 5
Formula 2: Wa / 50 <D2 <(Wa + Wb) / 4
Are configured to satisfy each of them simultaneously.

  The second embodiment is preferably applied in the range where the first lamp power Wa of the short arc mercury lamp SHL is 200 to 10000 W and the first lamp power Wb is 100 to 5000 W. In addition, D1 and D2 shall not include the part welded so as to overlap the sealing metal foil 1c in the present embodiment and the embodiment described below.

  In the above formulas 1 and 2, when the value is lower than the lower limit value, the electrode temperature at the time of flash-up lighting is excessively increased, and the thermal distortion of the glass of the sealing portion 1b increases and the hermetic container 1 is likely to be damaged. If the upper limit is exceeded, the electrode 2K or 2A becomes too long, leading to an increase in the size of the short arc mercury lamp SHL. Within the range of the above formulas 1 and 2, even when flash-up lighting is performed, the temperature during the lighting of the cathode 2K and the anode 2A is within the allowable range, and consumption of the electrode 2K or 2A is suppressed. Is prevented, the short arc type mercury lamp SHL has a long life, and the airtight container 1 is prevented from being damaged.

A third mode for carrying out the short arc type mercury lamp apparatus of the present invention is as follows. That is, in the short arc type mercury lamp SHL of this embodiment, the length of the portion extending from the sealing metal foil 1c of the cathode 2K is D1 (mm) in addition to the configuration in the first embodiment in FIG. When the anode length is D2 (mm), the first lamp power during normal lighting is Wa, and the second power added during flash-up lighting is Wb,
Formula 1: Wa / 60 <D1 <(Wa + Wb) / 12
Formula 2: Wa / 50 <D2 <(Wa + Wb) / 10
Formula 3: 200 ≦ Wa ≦ 1000
Formula 4: 100 ≦ Wb ≦ 500
Are configured to satisfy each of them simultaneously.

  In the above formulas 1 and 2, when the value is lower than the lower limit value, the electrode temperature at the time of flash-up lighting is excessively increased, and the thermal distortion of the glass of the sealing portion 1b increases and the hermetic container 1 is likely to be damaged. If the upper limit is exceeded, the electrode 2K or 2A becomes too long, leading to an increase in the size of the short arc mercury lamp SHL. In the case of flash-up lighting with a relatively small lamp power defined in Equations 3 and 4, if the flash-up lighting is performed within the range of the above Equations 1 and 2, the temperature during lighting of the cathode 2K and the anode 2A can be maintained. Within the allowable range, consumption of the electrode 2K or 2A is suppressed, blackening of the airtight container 1 is prevented, the short arc type mercury lamp SHL has a long life, and damage to the airtight container 1 is prevented.

  Accordingly, the third embodiment flashes up a relatively small short arc mercury lamp in which the first and second lamp power Wa of the short arc mercury lamp SHL is used in the range of Equations 3 and 4. This is a generally applicable range of cases.

The 4th form for implementing the short arc type mercury lamp device of the present invention is as follows. That is, in the short arc type mercury lamp SHL of this embodiment, the length of the cathode 2K is set to D1 (mm) and the length of the anode 2A is set to D2 (mm) in addition to the configuration in the first embodiment in FIG. When the first lamp power during normal lighting is Wa and the second power added during flash-up lighting is Wb,
Formula 1: Wa / 70 <D1 <(Wa + Wb) / 20
Formula 2: Wa / 65 <D2 <(Wa + Wb) / 16
Formula 3: 1000 ≦ Wa ≦ 4000
Formula 4: 500 ≦ Wb ≦ 2000
Are configured to satisfy each of them simultaneously.

  In the above formulas 1 and 2, when the value is lower than the lower limit value, the electrode temperature at the time of flash-up lighting is excessively increased, and the thermal distortion of the glass of the sealing portion 1b increases and the hermetic container 1 is likely to be damaged. If the upper limit is exceeded, the electrode 2K or 2A becomes too long, leading to an increase in the size of the short arc mercury lamp SHL. In the case where flash-up lighting is performed with the medium lamp power defined in Equations 3 and 4, the temperature during lighting of the cathode 2K and the anode 2AQ remains within the range of Equations 1 and 2 above even if flash-up lighting is performed. Within the allowable range, consumption of the electrode 2K or 2A is suppressed, blackening of the airtight container 1 is prevented, the short arc type mercury lamp SHL has a long life, and damage to the airtight container 1 is prevented.

  Therefore, in the fourth embodiment, when the first and second lamp electric power Wa of the short arc type mercury lamp SHL is flashed up for the medium type short arc type mercury lamp SHL used in the range of Equations 3 and 4. This is a generally applicable range.

A fifth mode for carrying out the short arc type mercury lamp apparatus of the present invention is as follows. That is, in the short arc type mercury lamp SHL of this embodiment, in addition to the configuration of the first embodiment in FIG. 1, the cathode length is D1 (mm), the anode length is D2 (mm), When the first lamp power during normal lighting is Wa and the second power is Wb,
Formula 1: Wa / 120 <D1 <(Wa + Wb) / 30
Formula 2: Wa / 100 <D2 <(Wa + Wb) / 25
Formula 3: 4000 ≦ Wa ≦ 10000
Formula 4: 2000 ≦ Wb ≦ 5000
Are configured to satisfy each of them simultaneously.

  In the above formulas 1 and 2, when the value is lower than the lower limit value, the electrode temperature at the time of flash-up lighting is excessively increased, and the thermal distortion of the glass of the sealing portion 1b increases and the hermetic container 1 is likely to be damaged. If the upper limit is exceeded, the electrode 2K or 2A becomes too long, leading to an increase in the size of the short arc mercury lamp SHL. When flash-up lighting is performed with a large lamp power as defined in Equations 3 and 4, within the range of Equations 1 and 2 above, the cathode 2K] and anode 2A lighting temperatures are acceptable even if flash-up lighting is performed. Within the range, consumption of the electrode 2K or 2A is suppressed, blackening of the airtight container 1 is prevented, the short arc type mercury lamp SHL has a long life, and damage to the airtight container 1 is prevented.

  Therefore, the fifth embodiment is generally used in the case of a large short arc type mercury lamp SHL in which the first and second lamp powers Wa of the short arc type mercury lamp SHL are used in the ranges of the mathematical expressions 3 and 4. This is the range to be applied.

A sixth mode for carrying out the short arc type mercury lamp apparatus of the present invention is as follows. That is, the short arc type mercury lamp SHL of this embodiment has a first lamp power Wa during normal lighting in addition to the configuration in any one of the first to fifth embodiments in FIG. When the electric power of Wb is Wb and the cross-sectional area of the welded portion of the cathode 2K and the anode 2A is S (mm ² ),
Formula 1: 0.001 <S / (Wa + Wb) <0.45
Formula 2: 200 ≦ Wa ≦ 2000
Formula 3: 100 ≦ Wb ≦ 1000
Are configured to satisfy each of them simultaneously.

In the sixth embodiment, in FIG. 1, not only welding one sealing metal foil 1c by welding to the base end portions of the cathode 2K and the anode 2A, but also sealing two sheets across the base end portion. You may weld the metal foil 1c from both surfaces of a base end part. In order to obtain the weld cross-sectional area S (mm ² ) of the cathode 2K and the anode 2A, the cross-sectional area is measured at a substantially central position in the direction of the axis of the joint between the sealing metal foil 1c and the sealing metal foil 1c. To do.

  In the above mathematical formula 1, when the value is lower than the lower limit value, the temperature of the welded portion of the electrode 2K or 2A with the sealing metal foil 1c becomes excessive during flash-up lighting, and the hermetic container 1 is likely to be damaged. On the other hand, when the upper limit is exceeded, the thermal distortion of the glass of the sealing portion 1b at the welded portion of the electrode 2K or 2A and the sealing metal foil 1c becomes large during flash-up lighting, and the hermetic container 1 is likely to be damaged. If it is within the range of the above formula 1, even if flash-up lighting is performed, the temperature during lighting at the welded portion between the cathode 2K and the sealed metal foil c of the anode 2A is within the allowable range, and the electrodes 2K and 2A Consumption is suppressed, blackening of the airtight container 1 caused by scattering of the electrode material and its compound is prevented, the short arc type mercury lamp SHL has a long life, and damage to the airtight container 1 is prevented.

A seventh embodiment for implementing the short arc type mercury lamp apparatus of the present invention is as follows. That is, the short arc type mercury lamp SHL of the present embodiment has a first lamp power Wa during normal lighting in addition to the configuration in any one of the first to sixth forms in FIG. Power of Wb, the surface area of the cathode 2K is Sa (mm ² ), and the surface area of the anode 2A is Sb (mm ² ),
Formula 1: 0.5 <(Wa + Wb) / Sa <10
Formula 2: 0.08 <(Wa + Wb) / Sb <5
Formula 3: 200 ≦ Wa ≦ 2000
Formula 4: 100 ≦ Wb ≦ 1000
Are configured to satisfy each of them simultaneously.

  In the seventh embodiment, the surface areas of the cathode 2K and the anode 2A refer to the entire surface area of the electrode.

  In the above formulas 1 and 2, when the value is lower than the lower limit value, the electrode temperature becomes excessively high during flash-up lighting, the thermal strain increases, and the hermetic container 1 is likely to be damaged. On the other hand, if the upper limit value is exceeded, the electrode 2K or 2A becomes large and the short arc type mercury lamp SHL becomes large. Within the range of the above formulas 1 and 2, even when flash-up lighting is performed, the temperatures of the cathode 2K and the anode 2A are within the allowable range, the consumption of the electrodes 2K and 2A is suppressed, and the airtight container 1 is blackened. This prevents the short arc type mercury lamp SHL from having a long life and prevents the airtight container 1 from being damaged.

The front view which shows the whole 1st form for implementing the short arc type mercury lamp of this invention A front view and a side view showing the cathode similarly enlarged A front view and a side view showing the anode similarly enlarged Similarly, the lamp power waveform diagram explaining the flash-up lighting

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1a ... Enclosing part, 1b ... Sealing part, 1c ... Sealing metal foil, 2K ... Cathode, 2A ... Anode, 3, 4 ... External lead structure, 5, 6 ... Thermal insulation film, Ck ... Coil part Ex: Exhaust tip off part, OC ... Lighting circuit, SHL ... Short arc type mercury lamp

Claims (5)

An ultraviolet permeable hermetic container having a surrounding portion that forms a discharge space therein and a pair of sealing portions that extend integrally from both ends of the surrounding portion and in which a sealing metal foil is hermetically embedded; A sealed metal foil having an end connected to a sealed metal foil embedded in the sealed portion of the hermetic container and a distal end projecting into the enclosure, and a proximal end embedded in the sealed portion of the hermetic container An anode whose front end protrudes into the enclosure and is opposed to the cathode at a small interval, a discharge medium containing mercury and a rare gas sealed in the hermetic vessel, and a portion that becomes a low temperature during lighting of the hermetic vessel A short arc mercury lamp with a heat insulating film formed on the outer surface;
A relatively large lamp in which the short arc mercury lamp is lit with a relatively small first lamp power during normal lighting, and a second lamp power is added to the first lamp power during intermittent bright lighting. A lighting circuit for lighting with electric power;
A short arc type mercury lamp device comprising: In the short arc type mercury lamp, the length of the portion extending from the sealing metal foil of the cathode is D1 (mm), the length of the portion extending from the sealing metal foil of the anode is D2 (mm), When the first lamp power during normal lighting is set to Wa (W) and the second power added during bright lighting is set to Wb (W),
Formula 1: Wa / 60 <D1 <(Wa + Wb) / 5
Formula 2: Wa / 50 <D2 <(Wa + Wb) / 4
The short arc type mercury lamp apparatus according to claim 1, wherein both are satisfied simultaneously. In the short arc type mercury lamp, the length of the cathode is D1 (mm), the length of the anode is D2 (mm), the first lamp power during normal lighting is Wa, and the second lamp is added during bright lighting. When the power of is Wb,
Formula 1: Wa / 60 <D1 <(Wa + Wb) / 12
Formula 2: Wa / 50 <D2 <(Wa + Wb) / 10
Formula 3: 200 ≦ Wa ≦ 1000
Formula 4: 100 ≦ Wb ≦ 500
The short arc type mercury lamp apparatus according to claim 1, wherein both are satisfied simultaneously. In the short arc type mercury lamp, the length of the cathode is D1 (mm), the length of the anode is D2 (mm), the first lamp power during normal lighting is Wa, and the second lamp is added during bright lighting. When the power of is Wb,
Formula 1: Wa / 70 <D1 <(Wa + Wb) / 20
Formula 2: Wa / 65 <D2 <(Wa + Wb) / 16
Formula 3: 1000 ≦ Wa ≦ 4000
Formula 4: 500 ≦ Wb ≦ 2000
The short arc type mercury lamp apparatus according to claim 1, wherein both are satisfied simultaneously. In the short arc type mercury lamp, the length of the cathode is D1 (mm), the length of the anode is D2 (mm), the first lamp power during normal lighting is Wa, and the second lamp is added during bright lighting. When the power of is Wb,
Formula 1: Wa / 120 <D1 <(Wa + Wb) / 30
Formula 2: Wa / 100 <D2 <(Wa + Wb) / 25
Formula 3: 4000 ≦ Wa ≦ 10000
Formula 4: 2000 ≦ Wb ≦ 5000
The short arc type mercury lamp apparatus according to claim 1, wherein both are satisfied simultaneously.

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