JP2005174723A - High-pressure mercury lamp and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lamp in which heating temperature at a pair of sealing tubes is made equal and deterioration of the right and left electrode is made nearly the same level, thereby improves the lamp lifetime, and its manufacturing method. <P>SOLUTION: This is the manufacturing method of a high pressure mercury lamp which comprises a high pressure mercury arc tube 10 and a reflector 20 and in which the high pressure mercury arc tube 10 comprises a light emitting part 11 with a nearly spherical shape, a pair of sealing tubes 12A, 13A extended from the both ends to the outside direction, and a pair of electrodes 16, 17 which are insertion arranged in the sealing tubes and of which respective tips are arranged opposed to each other in the arc tube, and in which one sealing tube 13A is fixed to the reflector 20. The outer diameter of the sealing tube 13A on the fixed side is made smaller than that of the other and the effective calorific value at the sealing tubes 12A, 13A is made equal. Therefore, the difference of temperature between the pair of sealing tubes and the electrodes become small, deterioration of both electrodes become equivalent, and the lamp failure due to deviation of electrodes is suppressed and the lamp has a longer life. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high-pressure mercury lamp, and more particularly to a technique for extending the life of a high-pressure mercury lamp assembled on a reflector.

  In recent years, high-pressure mercury lamps (hereinafter abbreviated as “lamps”) have been used as light sources for video devices such as liquid crystal projectors and DLP projectors. As shown schematically in FIG. 3, this type of lamp 1 includes an arc tube 10 and a reflector 20, and the light emission point of the arc tube 10 is located at a substantially focal position of the reflector 20. The light emitted from the light emitting point of the arc tube 10 is condensed on the illumination optical system 2 by the reflector 20 and collimated in the illumination optical system 2 to illuminate the display unit 3 such as liquid crystal. The illuminated light from the display unit 3 is configured to be projected onto a screen (not shown) by the projection optical system 4.

As shown in the example of an AC lamp in FIG. 4, a conventional arc tube 10 has a light emitting part 11 whose outer shape is spherical or elliptical, and a cylinder that protrudes linearly from both ends of the light emitting part 11 to both sides. The pair of sealing tube portions 12 and 13 are entirely made of glass, and conductive stems 14 and 15 are inserted into the respective sealing tube portions 12 and 13, respectively. Electrodes 16 and 17 are disposed in the light emitting portion 11 at the inner end of the light source 15, respectively. Further, both outer ends of the conductive stems 14 and 15 are configured as lead-out ends 14a and 15a. One of the pair of sealing tube portions 12 and 13 of the arc tube 10 is inserted or penetrated into an opening 21 provided at the apex position of the reflector 20 and fixed to the reflector 20 by a fixing material 22 such as cement. It is supported. Further, a base 18 is disposed at the lead-out end 15 </ b> A of the sealing tube portion 13 on the side fixed to the reflector 20. As this type of lamp, for example, there are technologies described in Patent Document 1 and Patent Document 2.
JP 2003-132840 A JP-A-5-283040

  In such a conventional lamp in which the arc tube 10 and the reflector 20 are integrally assembled, one sealing tube portion 13 is integrally fixed to the reflector, and the other sealing tube portion 12 is formed in the inner region of the reflector. It is in a free state. Therefore, heat generated by light emission from the light emitting unit 10 is transmitted from the light emitting unit 10 to the sealing tube portions 12 and 13 on both sides, and is radiated from the sealing tube portions 12 and 13. Since the heat of the reflector 20 heated by the heat from the light emitting unit 10 is also transmitted to the fixed sealing tube portion 13, the sealing tube portion 13 is a free-state sealing tube portion. The heat capacity is larger than 12, the temperature distribution of the lamp across both sealing tube portions 12, 13 is such that the temperature of the fixed-side sealing tube portion 13 is higher than the free-side sealing tube portion 12, and the lamp is sealed. When the extending direction of the pipe parts 12 and 13 is the left-right direction, the temperature distribution is asymmetrical. In such a mercury lamp, when discharge light emission between the electrodes 16 and 17 on both sides (hereinafter referred to as the left and right electrodes), that is, light emission due to electron collision, tungsten, which is the material of the electrode, may jump into the lamp. The probability of this phenomenon increases as the temperature rises. Therefore, if the temperature distributions of the left and right sealing tube portions 12 and 13 are different, the deformation amount of the left and right electrodes 16 and 17 held by them, in other words, the electrode The degree of deterioration is also different, and this causes a problem that the life of the lamp is reduced. In Patent Documents 1 and 2, techniques for prolonging the lifetime are proposed, but since both of them change the structure of the light emitting portion, there remains a problem that the manufacture becomes difficult.

  An object of the present invention is to provide a lamp capable of improving the lamp life by making the heating temperatures in the left and right sealing tube portions uniform, and making the deterioration of the left and right electrodes comparable, and a method for manufacturing the same. It is.

  The present invention comprises a high-pressure mercury arc tube and a reflector for fixing and supporting the high-pressure mercury arc tube, the high-pressure mercury arc tube extending substantially outwardly from both ends of the light-emitting unit and a substantially spherical light-emitting unit. A pair of sealing tube portions, and a pair of electrodes that are inserted in the respective sealing tube portions and have respective tips opposed to each other in the light emitting portion, and one of the pair of sealing tube portions is the above-mentioned In the high-pressure mercury lamp fixed to the reflector, the effective heat capacities of the pair of sealed tube portions are configured to be equal. That is, the heat capacity of one sealing tube portion fixed to the reflector is made smaller than the heat capacity of the other sealing tube portion, and the heat capacity obtained by adding the heat capacity of the reflector to the heat capacity of the one sealing tube portion is the other. It is configured so as to be approximately equal to the heat capacity of the sealed tube portion.

  The manufacturing method of the present invention includes a substantially spherical glass light emitting part, and a pair of glass sealing tubes each having an electrode inserted therein and joined to the light emitting part by thermal welding to seal the inside. Glass for forming the other sealing tube portion in the glass tube for forming one sealing tube portion of the pair of sealing tube portions. A glass tube having a smaller diameter than that of the tube is used. Alternatively, in the sealing step, the other sealing tube portion is formed with a heating time or a heating temperature when welding a glass tube for forming one sealing tube portion of the pair of sealing tube portions. Therefore, the heating time or the heating temperature is longer than that when the glass tube is welded.

  According to the present invention, since the effective heat capacities of the pair of sealing tube portions are equal, the temperature difference between the pair of electrodes inserted in the lamp is reduced, and the deterioration of the pair of electrodes is equalized. Thereby, the lamp failure due to the bias of electrode deterioration can be suppressed, and the life of the lamp can be extended.

  As the best mode for carrying out the present invention, the outer diameter of one sealing tube is made smaller than the outer diameter of the other sealing tube. Or the thickness dimension of one sealing pipe part is made smaller than the thickness dimension of the other sealing pipe part.

  Next, Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a first embodiment in which the present invention is applied to an AC type lamp. Parts equivalent to those of the lamp having the conventional structure shown in FIG. The basic configuration includes an arc tube 10 and a reflector 20 as in the conventional lamp. The arc tube 10 is entirely composed of a light emitting portion 11 whose outer shape is spherical or elliptical, and a pair of cylindrical sealing tube portions 12A, 13A linearly projecting outward from both ends of the light emitting portion 11. Is made of glass, and conductive stems 14 and 15 are provided inside the sealed tube portions 12A and 13A, respectively, and are arranged in the light emitting portion 11 at the inner ends of the conductive stems 14 and 15, respectively. Electrodes 16 and 17 are connected. Further, both outer ends of the conductive stems 14 and 15 are configured as lead-out ends 14a and 14a. And the pair of sealing tube portions 12A and 13A of the arc tube 10, that is, the right side sealing tube portion in the figure among the left and right sealing tube portions when the extending direction of these sealing tube portions is the left-right direction. 13A is inserted or penetrated into an opening 21 provided at the apex position of the reflector 20, and is fixedly supported on the reflector 20 by a fixing material 22 such as cement. Here, the left and right sealing tube portions 12A and 13A of the arc tube 10 have different outer diameters, and the outer diameter Rr of the right sealing tube portion 13A fixed to the reflector 20 is shown in FIG. Is formed in a smaller diameter than the outer diameter R1 of the sealing tube portion 12A on the left side of the figure in a free state. A base 18 connected to the lead-out end 15a of the conductive stem 15 is disposed at the end of the right sealing tube portion 12A.

  In the arc tube 10 fixed in the reflector 20 in this way, the light emitting point between the electrodes 16 and 17 in the light emitting section 11 is located at the focal point of the reflector 20. Further, in the first embodiment, as shown in FIG. 3, the emitted light emitted from the light emitting point of the arc tube 10 is condensed on the illumination optical system 2 by the reflector 20 and collimated in the illumination optical system 2 to be liquid crystal. The display unit 3 is illuminated, and the projection optical system 4 projects an image on the screen. However, this configuration is not shown in FIG.

  When manufacturing the lamp having the above-described configuration, the following method can be employed particularly when manufacturing the sealing tube portions 12A and 13A having different left and right outer diameters. As a first method, in the case of manufacturing an arc tube, usually, a light emitting portion made of glass spheres formed as separate members and conductive stems 14 and 15 having electrodes 16 and 17 in advance are interpolated to form a subassembly. It forms by the sealing process which joins the sealing pipe part which consists of a pair of glass tube which carried out by heat welding. At this time, sealing tubes 12A having different outer diameters are formed by heat-welding to the light emitting portion 11 using glass tubes having different diameters as the material of the left and right sealed tube portions 12A, 13A that are sub-assembled. , 13A.

  As a second method, glass tubes having the same diameter are used as the material of the left and right sealing tube portions 12A and 13A. In the sealing process, the glass tubes are welded while being melted by a burner or the like. When welding the right sealing tube portion 13A having a small outer diameter, the heating power of the burner is increased from the left side to increase the heating temperature, or the heating time for applying the burner to the glass tube is set to be longer than the left side. This is a method in which the thermal contraction of the glass tube is advanced to reduce the diameter of the right sealing tube portion 13A.

  The third method is a method in which the first method and the second method are combined, and the time during which the burner is applied to the left and right sealing tube portions when the sealing tube portions 12A and 13A having different diameters are welded. It is a method of making different. That is, when forming the right side sealing tube part 13A, a small-diameter glass tube is adopted, and the temperature of the burner applied to the glass part is set higher than that on the left side, or the time for applying the burner is set on the left side sealing. By making the tube portion 12A longer than the glass tube, the right sealing tube portion can be manufactured with a smaller diameter than the left side.

  In this way, in the lamp structure in which the outer diameter dimensions of the left and right sealing tube portions 12A and 13A are different and the right-side sealing tube portion 13A on the small-diameter side is fixed to the reflector 20, the right-side small-diameter sealing is performed. The stop tube portion 13A is smaller in volume and volume than the large-diameter left-side sealing tube portion 12A, and the heat capacity is reduced. Therefore, even if the heat capacity of the reflector 20 is added to the heat capacity of the sealing tube portion 13A in a state where the right sealing tube portion 13A is fixed to the reflector 20, the left sealing tube portion 12A in a free state. It can be suppressed to a capacity close to the heat capacity. That is, the effective heat capacities in the left and right sealing tube portions 12A and 13A are made substantially equal. Therefore, heat generated by light emission from the light emitting unit 11 when the lamp is turned on is transmitted from the light emitting unit 11 to the sealing tube units 12A and 13A on both sides, and the right sealed tube unit fixed to the reflector 20 Although the heat of the reflector 20 heated by the heat in the light emitting unit 11 is also transmitted to 13A, the right sealing tube portion 13A is formed in a small diameter, and as a result, the left and right sealing tube portions 12A, The temperature distribution due to the heating of 13A is substantially uniform. Therefore, discharge light emission is caused by collision of electrons between the left and right electrodes 16 and 17 disposed in the light emitting section 10, and tungsten, which is an electrode material, jumps out into the lamp and the electrodes 16 and 17 are gradually deformed. Even when a state occurs, since the temperature distribution of the left and right sealing tube portions 12A and 13A is uniform, there is no bias in the deformation or deterioration of the left and right electrodes 16 and 17, and the life of the lamp is improved. It becomes possible to do.

  Here, when considering the heat capacity values Ql and Qr of the left and right sealed tube portions 12A and 13A and the heat capacity value Qx by the reflector 20, the left and right each of the left and right so that the effective heat capacity of both is Ql = Qr + Qz. The outer diameter dimensions Rl and Rr of the sealing tube portions 12A and 13A are set. In general, since the heat capacity Qz of the reflector 20 is larger than the heat capacities Ql and Qr of the sealed tube portions 12A and 13A, the ratio Rr / Rl is preferably made as large as possible. When the heat capacity by the reflector 20 can be considered as a finite value with respect to the ratio Rr / Rl, the outer diameter dimensions Rl and Rr of the left and right sealing tube portions 12A and 13A are set so as to satisfy the above formula. Set. In FIG. 1, the thicknesses of both the sealing tube portions 12A and 13A are different from each other, but the thicknesses of both the sealing tube portions 12A and 13A are equalized. Needless to say, the outer diameter may be different.

  FIG. 2 is a cross-sectional view of Embodiment 2 of the present invention. Parts equivalent to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In the second embodiment, the glass tubes constituting the left and right sealing tube portions 12B and 13B of the arc tube 10 have the same outer diameter, but have different wall thicknesses. That is, the heat capacity of the right sealing tube portion 13B fixed to the reflector 20 is made smaller than the heat capacity of the left sealing tube portion 12B in the free state, and as a result, the heat capacities of the left and right sealing tube portions 12B and 13B are reduced. The equalization is the same as in the first embodiment, but here the thickness of the right sealing tube portion 13B is made thinner and the thickness of the left sealing tube portion 12B is made thicker. In the second embodiment, the outer diameters of both the sealing tube portions 12B and 13B are made equal, but the outer diameter size of the right sealing tube portion 13B is made smaller than that on the left side as in the first embodiment. You may combine a structure.

  According to this configuration, since the heat capacity of the right sealing tube portion 13B is smaller than that of the left sealing tube portion 12B by the thickness, the right sealing tube portion 13B is fixed to the reflector 20. Even when the heat capacity is increased, the heat capacities of the left and right sealing tube portions 12B and 13B can be made uniform. As a result, the temperature distribution of the left and right sealing tube portions 12B and 13B becomes uniform, so that there is no bias in the deformation or deterioration of the left and right electrodes 16 and 17, and the life of the lamp can be improved. Become.

  Although not shown, in the case of a lamp that is not restricted by the length of the arc tube, the lamp is inserted into the glass tube constituting the left and right sealing tube portions of the arc tube and the inside thereof. The lengths of the conductive stems may be different. That is, in order to make the heat capacity of the right sealing tube portion fixed to the reflector smaller than the heat capacity of the left sealing tube portion in the free state, the length of the right sealing tube portion is shortened, You may form the length of a sealing pipe | tube part longer than it.

  According to this, since the heat capacity of the right sealing tube portion is smaller than that of the left sealing tube portion by the length, the heat capacity is increased by fixing the right sealing tube portion to the reflector. Even in such a case, the heat capacities in the left and right sealing tube portions can be made uniform. Thereby, since the temperature distribution of the left and right sealing tube portions is uniform, there is no bias in the deformation or deterioration of the left and right electrodes, and the life of the lamp can be improved.

  Here, the present invention is not limited to the first to third embodiments as long as the heat capacity of the sealing tube portion fixed to the reflector is smaller than the heat capacity of the opposite sealing tube portion. You may make it select the material from which specific heat and heat conductivity differ for the glass tube which comprises each sealing tube part. The present invention can also be applied to a DC type high-pressure mercury lamp.

It is sectional drawing of Example 1 of this invention. It is sectional drawing of Example 2 of this invention. It is a schematic block diagram of the apparatus for an image | video to which the lamp | ramp of this invention is applied. It is sectional drawing which shows schematic structure of the conventional lamp | ramp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High pressure mercury lamp 2 Illumination optical system 3 Display part 4 Projection optical system 10 Light emission tube 11 Light emission part 12A Sealing tube part 13A with a small outer diameter Sealing tube part 12B with a large outer diameter Sealing tube part 13B with a small thickness Sealing tube portions 14 and 15 having a large thickness Conductive stems 16 and 17 Electrode 18 Base 19 Insulator 20 Reflector 21 Opening 22 Cement

Claims (6)

  A high-pressure mercury arc tube, and a reflector for fixing and supporting the high-pressure mercury arc tube. The high-pressure mercury arc tube includes a substantially spherical light emitting portion and a pair of outwardly extending from both ends of the light emitting portion. A sealing tube portion, and a pair of electrodes that are inserted in the respective sealing tube portions and have respective tips opposed to each other in the light emitting portion, and one of the pair of sealing tube portions is fixed to the reflector. A high-pressure mercury lamp, wherein the effective heat capacities of the pair of sealed tube portions are equal to each other.   The heat capacity of one sealing tube fixed to the reflector is made smaller than the heat capacity of the other sealing tube, and the heat capacity of the one sealing tube is added to the heat capacity of the reflector. 2. The high-pressure mercury lamp according to claim 1, wherein the high-pressure mercury lamp is configured to be substantially equal to a heat capacity of the stop tube portion.   3. The high-pressure mercury lamp according to claim 2, wherein an outer diameter of the one sealing tube portion is smaller than an outer diameter of the other sealing tube portion.   The high-pressure mercury lamp according to claim 2, wherein a thickness dimension of the one sealing tube portion is smaller than a thickness dimension of the other sealing tube portion.   High pressure composed of a substantially spherical glass light emitting portion and a pair of glass sealing tube portions each having an electrode inserted therein and joined to the light emitting portion by heat welding to seal the inside. When manufacturing a mercury arc tube, a glass tube having a smaller diameter than the glass tube for forming the other sealing tube portion in the glass tube for forming one sealing tube portion of the pair of sealing tube portions. A method for producing a high-pressure mercury lamp characterized by using High pressure composed of a substantially spherical glass light emitting portion and a pair of glass sealing tube portions each having an electrode inserted therein and joined to the light emitting portion by heat welding to seal the inside. When manufacturing the mercury arc tube, in the sealing step, the heating time or heating temperature for welding the glass tube for forming one sealing tube portion of the pair of sealing tube portions is set to the other sealing tube. A method for producing a high-pressure mercury lamp, characterized in that the heating time or the heating temperature is longer than when a glass tube for forming a stop tube portion is welded.

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