JP2551929C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to two flat long side surfaces and two short side surfaces extending in a direction directly opposite to a central region surrounding a discharge volume. A long glass tube with two end regions formed as a squeeze seal having: a pair of electrodes disposed in the discharge volume and coupled to a current supply line extending to the outside through the squeeze seal; , Ionizable packing,
And a high-pressure discharge lamp comprising the same. [0002] High-pressure discharge lamps of this type include high-pressure discharge lamps having both ends squeezed and provided with an outer tube, and high-pressure discharge lamps having both ends squeezed and having no outer tube. These high-pressure discharge lamps generally have a discharge tube made of quartz glass, in particular with a metal halide filling. High-pressure discharge lamps are preferably used in optical systems such as floodlights, floodlights and illuminators for stage, cinema and television. In that case, the typical lamp power is between 400W and 4000W. Low power types are used in show window lighting or general lighting (eg, 150 W). [0003] US Pat. No. 4,396,857 and EP-A-2668.
According to Japanese Patent Publication No. 21, a small high-power (35 W) high-pressure lamp having a discharge volume of 1 cm <3> or less and having outer tubes squeezed at both ends is known. In order to avoid the accumulation of excess metal halide at the lowest temperature point in the space behind the electrode and to assure precise electrode adjustment, the lamp has a squeeze seal, Has a cylindrical transition region in the direction of the discharge tube. In the plane of the squeeze seal, this transition area is reduced and enlarged with respect to the short side of the squeeze seal. Compared to the discharge tube, the transition region has a wall thickness reinforced by a stack of glass materials. A relatively good heat transfer and heat dissipation, which is inherently undesired, to the squeeze seal, and a relatively good heat radiation due to the large radiating surface of the cylindrical transition region. Thus, overall, the heat storage effect in this lamp is not completely satisfactory. further,
The manufacture of this type of lamp is relatively complicated since the transition area is manufactured in two manufacturing steps. The original squeezing process is performed using two squeezing jaws. [0004] Furthermore, German Utility Model No. 8912495 discloses a high-power (1000-2000 W) metal halide lamp operated without an outer tube and squeezed at both ends. The heat storage properties play a particularly critical role in this lamp, since the halide vapor pressure and the color temperature do not achieve their best desired values. Therefore, a thermal storage coating must be used in part, but this thermal storage coating increases the chromatic dispersion of the lamp and also causes shading. Another disadvantage of this type of lamp without an outer bulb is that the end area at the transition to the central area is mounted directly on the base, so that the end area is relatively easily broken. is there. Therefore, an object of the present invention is to further improve the heat storage effect at the end of the discharge tube and increase the temperature thereat in a high-pressure discharge lamp. According to the present invention, in order to solve the above-mentioned problems, according to the present invention, a central region surrounding a discharge volume is directly connected to a central region extending in the opposite direction. A long glass tube with two end regions formed as a squeeze seal with two flat long sides and two short sides, and disposed outside the squeeze seal in the discharge volume In a high-pressure discharge lamp composed of an electrode pair coupled to an extending current supply line and an ionizable filling, each squeeze seal is provided at the lateral end of its central region and on the longitudinal side, with a squeeze seal. Without changing the thickness, the width of the longitudinal side of the squeeze seal is less than or equal to the maximum width of the discharge vessel , and each squeeze seal has a cross section
Has a double T-shape, the edges of which the legs of both T-shaped are joined to enlarge the short side
A flat longitudinal side with a bulge is formed, the edge bulge towards the central area
Enlarge to form a reinforcement. [0007] Particularly advantageous embodiments of the invention are set out in the dependent claims. [0008] The high-pressure discharge lamp according to the invention can omit a special transition region, instead a reduced part is formed during the pressing process in a single manufacturing step as part of the pressing seal. Therefore, it can be manufactured particularly easily. The end regions formed as squeeze seals are thickened only in the plane of the squeeze, not in the cross direction, ie with respect to the short sides. In this way, the glass material present in this region is significantly reduced. The emitting surface is likewise smaller. A very good heat storage effect is thus obtained, which increases the burner end temperature. Typically, the temperature rises, for example, by 50-100 ° C. As a result, it is possible to omit a heat storage film that reduces chromatic dispersion, increases the amount of light (5 to 10%), and improves color reproducibility. A particularly important advantage of the present invention is that the consistency of the color temperature starting from a clearly lower initial value is significantly improved. Generally, in metal halide discharge lamps, the color temperature drops significantly during the first 500 hours of operation. This is due to the gradual formation of a metal halide reservoir in the capillary present along the electrode rod between the foil and the discharge volume by diffusion. This is because the coefficient of thermal expansion of the tungsten electrode rod is significantly different from the coefficient of thermal expansion of the quartz glass tube. This reservoir can no longer contribute to the vapor pressure in the discharge volume. [0011] The use of a cylindrical transition region necessitates in the prior art this capillary to be lengthened and thus the color temperature to be disturbed significantly. In contrast, in the present invention, the length of the capillary is kept extremely short irrespective of the formation of the reduced portion, so that the decrease in the color temperature is significantly limited. The length of the capillary is up to about 1 of the length of the discharge volume.
0%. For a lamp with a cylindrical transition region, the corresponding value is about 28% in U.S. Pat. No. 4,396,857 and about 54% in EP-A-266821. (!). This advantage is particularly important in high power lamps without an outer bulb. In a preferred embodiment of the invention, the end regions are shaped in a double T-shape. This means that the short side of the squeeze seal is enlarged and an edge bulge is formed with respect to the plane of the squeeze seal. In a particularly advantageous embodiment of the invention, the edge bulge is enlarged as a supplementary reinforcement towards the central region, in particular over the entire length of the reduction. In this way, the squeeze seal at the joint to the central region is additionally mechanically stabilized. Breakage of the end region is reliably prevented. The reduction and reinforcement are particularly important in the case of lamps without an outer bulb. Since the glass material saved in the reduction during the squeezing process can be distributed to the reinforcement, the combination of the two measures (reduction and reinforcement) provides a particularly advantageous co-operation during production. The precise centering of the electrode system is particularly ensured if at least one centering ridge is provided on at least the longitudinal side of the squeeze seal. The production of the centering ridge is carried out once during the squeezing process without additional cost, by having at least one of the squeezing jaws has at least one hole in the squeezing surface. In a particularly advantageous manner, the area immediately following the end area of the central area is subsequently formed by a pressing jaw during the pressing operation. At the end of the central region, a tangential slope is formed at its end, which reduces the discharge volume behind the electrode. The method of manufacturing a high-pressure discharge lamp according to the invention is characterized by time savings and maximum simplification. The shaping of the contraction and the centering of the reinforcement and the electrode system can be carried out in a single production step in a pressing process using four pressing jaws. Important are two main squeeze jaws which form the longitudinal side of the squeeze seal, of which at least one squeeze jaw has a hole for the centering ridge and a ramp for the reinforcement. In addition, two side squeezing jaws with a roof-shaped protruding nose at the end of the central region are used, which form the reduction and the reinforcement. Particularly good shaping of the squeeze seal is obtained by a short delay in the side squeezing process compared to the main squeezing process. Next, the present invention will be described based on examples. FIGS. 1 and 2 show a 2000 W high-pressure discharge lamp 1 having a length of about 190 mm and requiring no outer tube. This high-pressure discharge lamp 1 is intended for mounting in a reflector, not shown, and is mounted axially in the reflector. The high-pressure discharge lamp 1 has a tube 2 consisting of a central region and two end regions extending in opposite directions. Approximately 2 mm (or 2.5 mm
In a very good approximation made of quartz glass having a wall thickness of 3), the isothermal discharge tube 3 is embodied as a barrel, so that an arc with a radius of curvature of 38.25 mm is formed. The barrel has a maximum outer diameter of 36 mm and an axial length of about 51 mm.
The outer diameter of the barrel end 4 is about 16 mm and therefore the discharge volume is about 22 cm3. The barrel end portions 4 are each formed with an end region portion 5 that forms a compression seal. The tip of the rod-shaped tungsten electrode 6 has an interval of 30 mm,
Each is axially held in an end region 5 and has a two-layer filament 7 near the tip of the electrode. The end region 5 has a length of about 40 mm and a width of about 16 mm. The electrode 6 is connected to a current supply line (not shown) via a molybdenum foil 8 hermetically sealed in a squeeze seal. This current supply line contacts the strands 9 of the two bases. The molybdenum foil 8 has a length of about 30 mm and a width of 8 mm. At the end of the squeezed sealing portion 5 remote from the base, both ceramic bases 10 each including a cylindrical holding member 11 having a slit and a flat socket-side end member 12 are joined with a bonding agent. Has been fixed by. The foil 8 is arranged inside the compression-sealing portion such that the distance between the foil end and the end of the compression-sealing portion 5 is about 4 mm on the discharge side. Only over this short section is a capillary formed in the squeeze seal 5 along the tungsten electrode 6, which collects the metal halide reservoir. The longitudinal side 13 of the squeeze seal 5 has a bulge 14 at the edge towards the short side 15, so that the squeeze seal 5 has a generally double T-shaped cross section (ie, Two "Ts" form a butt joint at their leg sides). The thickness of the compressed sealing portion 5 is about 4 mm, and the thickness of the edge bulging portion 14 at the short side surface 15 is about 7 mm (see FIG. 3). The longitudinal side 13 towards the central region has a reduced section 1 in the form of two ramps over an axial length of about 5.5 mm.
6 so that at the junction of the end region to the central region the longitudinal side 1
3 is reduced to about 12 mm without changing the thickness of the compressed sealing portion 5. At the same time, the thickness of the edge bulges 14 is increased towards the central region, whereby a reinforcement 17 is formed, especially in the region of the slope. The thickness of the edge bulging portion 14 is about 7 m.
m, it gradually increases to about 8 mm at the bending point 18 of the inclined portion, and further reaches about 10 mm at the joining point of the reinforcing member 17 to the central region. The longitudinal side surface 13 of the squeeze seal is provided with a corrugated groove (not shown),
Further, the centering ridge 1 long at the height of the electrode 6 and the height of the external current supply line 9 is provided.
9a and 19b. In the area of the central area which follows the end area, a total of four zones in the direction of the long side 13 and the short side 15 of each squeeze seal are formed as flat surfaces 20 of approximately square dimensions. The flat surface 20 is close to the curved surface in the central region as a substantially tangential surface. This flat surface 20 forms an obtuse angle with the surfaces of the long side surface 13 and the short side surface 15, particularly about 150 ° and 130 °. In this way, the discharge volume behind the electrodes is further reduced, which increases the cold spot temperature. The discharge tube 3 contains a rare gas (argon) as an ignition gas and a main component (about 220 mg).
As the rare earth gas DyBr3 (1 μmol
), TmBr3 (0.5 μmol), 1 μmol TlBr, 2 μmol
Of CsBr and 0.5 .mu.mol of ThI4. Thorium can be replaced by hafnium. Overall this filling allows 92 (
A color reproduction index of 90 (conventionally 90) is produced, and about 5700K (59 conventionally).
00K) is produced. The given rare earth filling has the values x = 0.333 and y = 0.346 as color spots. At a supply voltage of 380 V and a lamp current of 10.3 A, a combustion voltage of 225 V is obtained. An advantageous overall concept of a 2000 W lamp is that the total light quantity is between 100 lm / W and 105 lm
/ W, and an extremely long life of about 2000 hours can be obtained. The specific arc power is 67 W / mm. An isothermally formed discharge tube has a maximum tube temperature of about 1030 ° C. (hot spot), which is 1000 ° C. at the cold spot (at the tube end and behind the electrode).
Conventionally, it drops to about 940 ° C.). At the end of the foil, the temperature drops to 230 ° C. (conventionally 250 °) (free burning). For a floodlight this is 330 ° C (conventionally 35 ° C).
0 ° C). It should be noted that the concept of "conventional" means a structurally identical lamp without a reduction section. The special design of the compression seal results in a significant improvement in the operating data of this lamp, based on the heat storage of the reduction section, compared to a conventional compression seal. further,
The tangential surface at the end of the central region increases the temperature in the volume behind the electrode (cold spot region). The luminous flux is kept almost constant over the operating life (maintenance) at an initial value of 205000 lm. The reduction is only about 5% (conventionally about 15%). Color temperature (Fig. 4)
Indicates an initial value (solid line) of 5700K, which is 20 times smaller than the conventional value (dashed line).
It means a descent of 0 °. At the same time, the temperature during the lifetime (ΔT = 500K)
Is significantly smaller than in the past (ΔT = 900K after a running time of 1500 hours). Other advantages are improved combustion voltage (5-10% higher with the present invention),
Good stabilization of the re-ignition peak voltage (340 V) at the beginning of the lamp operating life. The heat storage effect of the reduced compressed seal will be described with reference to FIGS. 5 and 6. FIG.
FIG. 6 shows the longitudinal side of a squeeze seal of a conventional lamp without a reduced part, and FIG. 6 shows the longitudinal side of a squeeze seal of the lamp of the present invention with a reduced part. The temperature distribution is indicated by isothermal lines, in which case isothermal line a indicates the highest temperature and isothermal line g indicates the lowest temperature. The temperature d absolutely corresponds to 350 ° C. A conventional squeeze seal (FIG. 5) has a relatively steep slope over its length and has a relatively high temperature d at its end. Due to the provision of the constriction (FIG. 6), the squeeze seal as a whole is subjected to a relatively low temperature load (e), and this temperature load extends over the length of the squeeze seal, in particular for the foil encapsulation. It is remarkably evenly distributed over the area. That is, the overall temperature drops at the base end, the sealing effect of the foil encapsulation is improved, and the foil encapsulation bears only a small burden. 5 and 6, the discharge side edge zone of the squeeze seal is not detected for measurement technology reasons. The squeeze seal no longer breaks due to the reinforcement. In the case of a lamp having a structure almost identical to that for a rated power of 1000 W in which a heat storage film made of ZrO 2 is provided at the end of a conventional discharge tube, this film is replaced in the present invention. It is not omitted because it is omitted. The light output is thereby improved by 5 to 10%, similar to a 2000 W lamp. In another embodiment of a metal halide lamp having a rated power of 400 W, the shape of the lamp tube is substantially the same as the shape of the lamp tube in FIGS.
The lamp tube, however, is housed within the outer tube and is generally smaller. If the total length is 36 mm, the squeeze seals each have a length of about 20 mm, of which 4 mm is the area of the reduced part. A foil having a length of 13 mm is enclosed approximately in the center of the squeeze seal, so that the electrode rods and the external current supply lines are each embedded about 3.3 mm in the squeeze seal. The 16 mm width of the squeeze seal is reduced to 9 mm at the reduced part. The thickness of the squeeze seal is about 2 mm, increasing to 4 mm in the region of the edge bulge. The edge bulge itself is enlarged to 6 mm over the length of the contraction under the formation of a reinforcement facing the central region. Another embodiment of a metal halide lamp is shown in FIGS. 7 and 8. The metal halide lamp has a hard glass cylindrical outer tube 21 having a screw base 22 at one end and a round head 23 at the other end.
Is provided. Coaxially with the outer tube 21, a quartz glass tube 24 having two axially opposed electrodes is disposed in the outer tube as a discharge tube, and the quartz glass tube 24 has two current supply lines. 26 are held by the gantry 25 and are hermetically sealed in the outer tube 21. The discharge tube has a tubular central body 27, the ends of which are sealed by box-shaped squeezed parts 28, i.e. without edge bulges. The width of the pressing portion is the same as the outer diameter of the central base 27. The squeezed portion has a reduced portion 29 as in the first embodiment, and the reduced portion 29 has a width of 16 mm to 9 mm.
mm. The thickness of the pressed part is about 2 mm. The short side surface of the squeezed portion is enlarged to a reinforcing body 30, and the reinforcing body 30 has a thickness of 4 mm at the joint in the central region. The manufacture of the lamp starts with a blank for a quartz glass tube, for example, having a barrel-shaped central region (see FIG. 1) and two tubular end regions. A pump is first connected to this material at the center. The electrode system is composed of an electrode, a molybdenum foil and an external current supply line, in which case the electrode and the external current supply line are welded to the molybdenum foil, respectively, and the electrode system is inserted from below into the tubular end region, Attached there with the AC input. After a cleaning step with argon gas, the end region is brought to a squeezing temperature (about 1700 ° C.) by means of two gas burners. In doing so, the tube section located in the deformation region should likewise reach the squeezing temperature. Under argon flush,
The end area is finally squeezed by a four-jaw squeezer. Both main pressing jaws 31 (
FIG. 9) shapes the longitudinal side of the squeeze seal. The squeezing surface 32 of both main squeezing jaws has a depression 33 for the centering of the electrode system, which depression appears as a centering ridge in the compression seal. At the upper end 34 of the main pressing jaw on the side of the central area, two side inclined portions 35 are provided on the pressing surface, whereby two side pressing jaws 36 (FIG. 10) are provided.
Can mesh with each other. The third inclined portion 37 reduces the pressing surface 32 by about 6
It is guided near its upper end 34 at an angle of 0 °. This slope 37 helps the central area to perform tangential shaping. At the side edge of the squeezed surface, a step 38 for forming an edge bulge is formed. Intersecting with the main squeeze jaws, two side squeeze jaws 36 (FIG. 10) act, the squeeze surface 39 shaping the short side of the squeeze seal. At the upper end of the squeezing surface, a nose 40 protrudes like a roof, with the peak 41 extending parallel to the upper ridge of the squeezing surface. The lower roof slope 42 projecting from the squeezing surface is inclined at an angle of 30 ° from the plane of the squeezing surface 39, and the upper roof slope 43 has an inclination of 50 ° with respect to this. The lower roof slope 42 creates a reduction, while the upper roof slope 43 shapes the remaining two tangent surfaces of the central region. The upper ridge of the main pressing jaw ends at the rooftop of the side pressing jaw. The reinforcement at the edge bulge is created by the side ramp 35 of the main compression jaw having another slope (19 °) as the lower roof ramp 4 of the side compression jaw. The side squeeze jaws are slightly delayed in time with respect to the main squeeze jaws (about 0.5
Second) operation has proven to be particularly advantageous. Subsequently, the glass tube is rotated and the second end region is closed by the same technique. Evacuation, cleaning and filling of the discharge tube are performed by HAMP in a known manner.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a high-pressure discharge lamp having a 2000 W input. FIG. 2 is a side view showing the high-pressure discharge lamp shown in FIG. 1 rotated by 90 °. FIG. 3 is a cross-sectional view of the squeeze seal with the base removed. FIG. 4 is a characteristic diagram showing a color temperature of a lamp showing a function of an operating life. FIG. 5 is a schematic diagram showing a temperature distribution in a squeezed sealing portion of a conventional lamp. FIG. 6 is a schematic view showing a temperature distribution in a squeezed sealing portion of a lamp according to the present invention. FIG. 7 is a side view of a high-pressure discharge lamp having an input of 400 W; FIG. 8 is a side view showing the lamp shown in FIG. 7 rotated by 90 °. FIG. 9 is a schematic view showing a main pressing jaw for manufacturing this type of lamp, wherein a is a front view,
b is a side view. FIG. 10 is a schematic view showing a side pressing jaw for manufacturing this type of lamp, wherein a is a front view and b is a side view. [Description of Signs] 1 High-pressure discharge lamp 2 Glass tube 3 Central region 5 End region 6 Electrode 13 Long side 14 Edge bulge 15 Short side 16 Reduced portion 17 Reinforcement 19 Centering raised portion

Claims (1)

Claims 1. A central region (3) surrounding a discharge volume and two flat longitudinal sides (13) extending in opposite directions and directly connected to the central region (3). Two end regions (5) formed as squeeze seals with two short sides (15)
A long glass tube (2) comprising: a pair of electrodes (6) disposed in the discharge volume and connected to a current supply line extending to the outside through the squeeze seal; and an ionizable filling. In the constructed high-pressure discharge lamp, each of the squeezed seals (5) is provided at the side end of its central region (3) and on the longitudinal side without reducing the thickness of the squeeze seals (5). 16), wherein the width of the longitudinal side of the compression seal (5) is smaller than or equal to the maximum width of the discharge tube , and each of the compression seals (5) is cut off.
Said flat longitudinal sides (13) with enlarged edge bulges (14) are formed;
The edge bulge portion (14) expands toward the central region (3) and is reinforced.
A) a high-pressure discharge lamp, characterized in that: Wherein said reinforcing member (17) is a high pressure discharge lamp according to claim 1, characterized in that it is formed in a region of the reduction unit (16). 3. A longitudinal side (13) of the squeeze seal (5) has one or more centering ridges (19) for the electrode (6) and / or the current supply line (9).
2. The high-pressure discharge lamp according to claim 1, comprising: a, 19b). 4. An area (6 ') of an electrode embedded in said squeeze seal (5).
2. The high-pressure discharge lamp as claimed in claim 1, wherein the lamp is very short and is located completely within the area of the reduction. 5. The high-pressure discharge lamp according to claim 1, wherein the width of the flat longitudinal side surface is reduced by about 30% to 50% by the reduction portion. 6. The high-pressure discharge lamp according to claim 1, wherein the reduction portion forms an inclined portion. Wherein said shorter side (15) of the high-pressure discharge lamp according to claim 1, wherein the expanding about 30%. 8. The length of the reduction section (16) is about 10 to 10 of the total length of the squeeze seal section.
The high-pressure discharge lamp according to claim 1, wherein the discharge pressure is 25%. 9. The central area (3) is bulged, in which case a flat surface (20) is formed at the junction of the central area (3) to the squeeze seal (5), 2. The high-pressure discharge lamp according to claim 1, wherein the flat surface approximates a curved surface of the central region to a substantially tangential surface. 10. The high pressure discharge lamp according to claim 1, wherein the lamp tube is a single tube. 11. The high pressure discharge lamp according to claim 1, wherein the filling includes a metal halide.