Short arc type discharge lamp

Abstract

The utility model provides a short arc discharge lamp which is easy to manufacture and can properly control the flow of gas generated in a bulb when the lamp is lightened. The anode (4) has a tapered section (41) and a skirt section (48), the outer periphery of which expands linearly in the radial direction toward the rear. The skirt section (48) has a first guide surface (48) and a second guide surface (48b) that guide the gas flowing along the tapered section (41) in the direction of the bulb (2). The angles alpha and beta between the tangent from the first guide surface (48) and the second guide surface (48b) and the tangent at the intersection point of the bulb (2) are both 100 degrees or less. The outer diameter P2 of the skirt (48) is equal to the maximum outer diameter P1. Therefore, the reduction of the sealing tube part of the bulb (2) during manufacturing can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a short-arc discharge lamp, and in particular to a short-arc discharge lamp that prevents the arc from shaking. BACKGROUND

[0002] In Japanese Patent Application Publication No. 2006-12672, an anode is disclosed in which a blade-like protrusion is provided at the end of the root portion, thereby controlling the flow of gas.

[0003] However, a lamp in which such an anode provided with a blade-like protrusion is formed is almost impossible in reality. Generally, in the manufacture of a discharge lamp, the following manufacturing process is performed: a bulb is manufactured in which the sealed tube portion is larger than the maximum outer diameter portion of the anode, the anode is positioned inside the bulb via the sealed tube portion, and then the diameter is reduced by baking with a burner. This is because, if the diameter of the sealed tube portion is large, the operation of reducing the diameter from the large diameter is required. SUMMARY

[0004] The present utility model aims at solving the above problems and providing a short-arc discharge lamp that is easy to manufacture and can appropriately control the flow of gas generated inside the bulb at the time of lighting.

[0005] (1) The short-arc discharge lamp of the present utility model is a vertically arranged short-arc discharge lamp, which has: a bulb having a light emitting tube portion and a sealed tube portion arranged to extend outward from both ends of the light emitting tube portion; a cathode arranged inside the light emitting tube portion; a conical anode having a main body portion and a front end portion continuously arranged with the main body portion and tapering toward the front end, the anode being arranged opposite to the cathode, the diameter of the rear end side of the main body portion being smaller than the diameter of the front end side of the main body portion; and an anode core rod supporting the anode, the anode being arranged on the upper side and lit, wherein the main body portion has a protrusion portion expanding in the radial direction with the outer circumference toward the rear of the anode at the rear end portion, the maximum diameter of the protrusion portion being substantially the same as the maximum diameter in the main body portion, or the maximum diameter of the protrusion portion being equal to or less than the maximum diameter in the main body portion.

[0006] Therefore, in the vertically arranged short-arc discharge lamp, the gas flow can be controlled by the protrusion portion without providing an unnecessary protrusion on the anode.

[0007] (2) In the short-arc discharge lamp of the present utility model, the conical shape is a straight conical shape or a streamline shape. Therefore, the gas flow can be controlled.

[0008] (3) In the short-arc discharge lamp of the present application, the protruding portion has a first guide surface that controls the flow of gas moving along the side surface of the anode in the direction of the bulb, and a second guide surface that is opposite to the first guide surface and controls the convection of the base surface of the stem of the anode in the direction of the bulb. In the case where a tangent line in the first guide surface is defined as a first tangent line, and a tangent line at the intersection of the first tangent line and the inner side surface of the sealing body is defined as a first inner side surface tangent line of the sealing body, the angle of the anode front end side in the intersection angle of the first tangent line and the anode front end side of the first inner side surface tangent line of the sealing body is 100 degrees or less. In the case where a tangent line in the second guide surface is defined as a second tangent line, and a tangent line at the intersection of the second tangent line and the inner side surface of the sealing body is defined as a second inner side surface tangent line of the sealing body, the angle of the anode front end side in the intersection angle of the second tangent line and the anode front end side of the second inner side surface tangent line of the sealing body is 100 degrees or less.

[0009] Therefore, the gas flow can be controlled more efficiently.

[0010] (4) In the short-arc discharge lamp of the present application, in the tapered shape, the taper angle defined by a straight line connecting the maximum diameter portion of the main body portion and the minimum diameter portion of the main body portion is 10 degrees or less. Thus, more gas flow can be guided to the protruding portion along the anode.

[0011] (5) In the short-arc discharge lamp of the present application, the angle of the anode front end side in the intersection angle of the first tangent line and the anode front end side of the first inner side surface tangent line of the sealing body and the angle of the anode front end side in the intersection angle of the second tangent line and the anode front end side of the second inner side surface tangent line of the sealing body are substantially equal or the former is smaller. Thus, the turbulence around the protruding portion can be further reduced.

[0012] (6) In the short-arc discharge lamp of the present application, the main body portion is composed of a main body main body and a hollow cylindrical portion located outside the main body main body, and the hollow cylindrical portion has the protruding portion. Thus, by being composed of a plurality of components, the main body main body and the hollow cylindrical portion can be formed respectively. Thus, for example, the material of the main body main body and the hollow cylindrical portion can be changed, and the entire lamp can be made lightweight.

[0013] The terms used in the claims are explained. In the embodiment, the "projection" corresponds to the skirt 48. In the embodiment, the "first tangent line" corresponds to the first imaginary extension line. In addition, in the case where the first guide surface 48a is constituted by a straight line, the "first tangent line" corresponds to the straight line itself, and in the case where the first guide surface 48a is constituted by a curved line, the "first tangent line" corresponds to the tangent line at the end portion. In the case where the front end of the skirt 48 is subjected to R processing or C surface processing, the tangent line at the end portion is the end portion at which the R processing or the C surface processing starts.

[0014] As in the first embodiment, the "straight line conical shape" or the "streamline shape" includes a shape in which the width gradually decreases as the body portion 40 goes toward the electrode rear end surface side, and also includes a case where the shape changes in steps. In addition, as shown in Figure 8A , a case where a bulging portion 61 having a smaller diameter than the above-described largest diameter portion is provided midway is also included. In addition, in the embodiment shown in Figures 1A-1C , the "second guide surface" is a concept including a circular arc-shaped recess of the anode 4 bottom surface, but as shown in Figure 9E , it is a concept including a case other than the circular arc shape, and further as shown in Figure 9D , it is a concept further including a case where the recess of the anode 4 bottom surface is not present. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figures 1A-1C is a main part cross-sectional view of the short arc discharge lamp 1 of the present application.

[0016] Figures 2A-2B is an enlarged cross-sectional view of the skirt 48.

[0017] Figures 3A-3B is a diagram for explaining the gas flow control based on the skirt 48.

[0018] Figures 4A-4B is a diagram showing a comparative example.

[0019] Figure 5 is a diagram showing the variation of the voltage.

[0020] Figures 6A-6B is a diagram showing a case where the condition is satisfied and a case where the condition is not satisfied.

[0021] Figures 7A-7C is a diagram showing another embodiment.

[0022] Figures 8A-8F is a diagram showing a modified example.

[0023] Figures 9A-9F is a diagram showing a modified example.

[0024] REFERENCE NUMERALS

[0025] 2: Bulb; 3: Cathode; 4: Anode; 7: Core rod; 9: Bead; 40: Main body; 41: Conical part; 42: Straight part; 46: Front end; 48: Skirt; 48a: First guide surface; 48b: Second guide surface; 48k: Bottom surface; Q1: First intersection point; Q2: Second intersection point; L1: First imaginary extension line; L11: Tangent line on the inner surface of the first sealing body; L2: Second imaginary extension line; L21: Tangent line on the inner surface of the second sealing body. Detailed Implementation

[0026] (1. First Implementation Method)

[0027] The short-arc discharge lamp of this utility model will be described with reference to the accompanying drawings. Figures 1A-1C As shown, the short-arc discharge lamp 1 is a 13.5kW mercury lamp. Inside the bulb 2, there is an anode 4, a cathode 3 opposite to the anode 4, and a core rod 7. A bead 9 is placed between the bulb 2 and the core rod 7. Furthermore, the cross-sectional lines of the core rod 7 are omitted in the figures.

[0028] The anode 4 has a main body 40 and a front end 46. The main body 40 has a straight section 42, a tapered section 41, and a skirt section 48 from the front end to the rear end. The diameter of the straight section 42 is P1, and the front end 46 is machined to taper from the straight section 42.

[0029] In this embodiment, the diameter P1 = 40 mm, but it is not limited to this. In addition, the straight portion 42 tapers to a tapered angle θ towards the skirt portion 48.

[0030] In this embodiment, θ = 5 degrees. The outer periphery of the skirt portion 48 provided at the rear end of the anode 4 expands linearly in the radial direction as it moves toward the rear of the anode 4. In addition, an R-shaped machining portion is provided between the skirt portion 48 and the end of the tapered portion 41 to allow for smooth airflow.

[0031] The first guide surface 48a of the skirt 48 guides the gas flowing along the tapered portion 41 towards the bulb 2. Figure 2A The relationship between the first guide surface 48a and the bulb 2 will be explained. In this embodiment, the first guide surface 48a is composed of a straight line La. When the angle of intersection between the imaginary extension L1 (obtained by extending this straight line) and the tangent to the inner surface of the bulb 2 at point Q1 (where the tangent intersects the bulb 2) is set to α (the angle at the center of the bulb), α is set to 100° or less. This is because if the angle α is less than 90°, the gas colliding with the bulb 2 should be guided towards the bead 9 (upwards). Here, the gas exhibits a rising effect based on buoyancy. Therefore, if the angle is approximately +10°, it will be guided towards the bead 9 (upwards).

[0032] Further, as shown in Figure 1B The skirt 48 has a second guide surface 48b on the electrode bottom surface 48k. Figure 1C is a view of the anode 4 as viewed from the bottom surface side. The second guide surface 48b is formed in a circular ring shape in a manner of surrounding the core rod 7. As shown in Figure 1B The cross-sectional shape of the second guide surface 48b is in a circular arc shape. In a case where an intersecting angle of an imaginary extension line L2 (a tangent line extending from the end portion) of the circular arc and a tangent line of the inner surface of the bulb 2 at a point Q2 where the tangent line intersects the bulb 2 is set to β, β is set to 100° or less. This is because if the angle β is less than 90°, the gas colliding with the bulb 2 should be guided to the bead 9 side (to the upper portion). Here, the above gas has an ascending effect of the gas based on the buoyancy. Therefore, if it is about +10°, it will be guided to the bead 9 side (to the upper portion).

[0033] In the present embodiment, a tungsten column having a diameter of 40 mm is cut, the outer diameter of the skirt 48 is increased, and the gas flow is effectively controlled, and thus PI = P2. However, it is not limited thereto, and PI > P2 can also be possible.

[0034] The control of the gas flow based on the skirt 48 will be described. Figures 3A-3B When the arc discharge occurs, the arc is pinched due to the Lorentz force acting on the arc, and as a result, a pressure gradient is generated from the vicinity of the cathode to the center portion of the arc, which becomes a driving force, and the gas flow flows along the tapered portion 41 of the anode 4.

[0035] In the anode 4, the tapered portion 41 is formed in a direction in which it narrows in a direction away from the cathode (in a direction toward the root portion of the anode 4). In the present embodiment, the taper angle θ is set to 5 degrees. Therefore, the gas flow flowing from the cathode 3 toward the anode 4 does not peel off from the surface of the anode 4, and the gas easily flows to the bead side of the anode 4. This is because the gas wants to flow along the anode 4, but the resistance at that time becomes small.

[0036] Further, if the flow of the gas is controlled only inward, it can also be considered that the above taper angle is greater than 10 degrees. However, when the taper angle is increased, the cross-sectional area perpendicular to the axial direction of the rear end of the anode becomes small. As a result, it is difficult to efficiently transport the heat of the front end of the anode to the rear portion of the anode. In the present embodiment, in order to secure the cross-sectional area perpendicular to the axial direction in the region having the smallest diameter connected to the skirt 48, the taper angle is set to be a taper angle θ and to be 10 degrees or less. Thereby, both the transport of the heat and the control of the gas flow can be satisfied.

[0037] The gas reaching the skirt 48 is decelerated by the first guide surface 48a and changes the flow direction toward the bulb 2, like the gas flow F11 (refer to

[0038] Figure 3A ​In this way, it moves towards bulb 2 and collides with the inner wall of bulb 2. Here, since the angle α of the collision part is less than 100°, more gas is guided towards bead 9. Thus, the speed and direction of the collision with bulb 2, as well as the flow of air, are controlled by skirt 48.

[0039] Without the first guide surface 48a of the skirt 48, the airflow is throttled and directed along the core rod 7 toward the bead 9 (see reference). Figures 1A-1C The flow near the bead increases the thermal density of bead 9, thus increasing the heat load in the vicinity of bead 9. As a result, strain is generated in the glass near bead 9, which, in the worst case, could lead to breakage.

[0040] In contrast, with the first guiding surface 48a, the airflow is dispersed radially, thereby reducing the thermal density of the airflow and lowering the thermal load on the bulb. As a result, the bulb is less susceptible to thermal strain and will not break even after prolonged use.

[0041] Furthermore, the airflow flowing towards bead 9 descends along the core rod 7 as a downward airflow, reaching the second guide surface 48b (F1~F2). This airflow flows along the second guide surface 48b, and is therefore directed towards… Figures 1A-1C The imaginary extension line L2 shown guides the airflow in the direction of (F3~F4). The direction of this return airflow is roughly the same as that of the airflow that is guided by the first guide surface 48a and collides with the bulb 2, making it less likely to generate turbulence.

[0042] In contrast, such as Figure 3B As shown, in the absence of the second guide surface 48b, although the return airflow can be slowed down by utilizing the bottom surface of the anode, this return airflow flows directly in a direction perpendicular to the core rod 7, colliding with the airflow guided by the first guide surface 48a. This results in turbulence. This turbulence prevents the airflow guided by the first guide surface 48a from flowing towards the bead 9. Consequently, the airflow guided by the first guide surface 48a descends directly along the bulb 2 without decreasing in speed, traveling towards the cathode tip, potentially causing arc flickering.

[0043] By utilizing the two guide surfaces in the skirt 48 to control the speed and direction of airflow, the airflow is dispersed radially, reducing the thermal density of the airflow and the thermal load on the bulb. As a result, the bulb is less susceptible to thermal strain and will not break even after prolonged use.

[0044] In addition, to more effectively prevent the aforementioned turbulence, the imaginary extensions L1 and L2 are preferably approximately parallel or β > α.

[0045] In addition, the gas guided from the first guide surface 48a to collide with the bulb 2 and flow in the lower direction is sufficiently decelerated, and further decelerated to flow to the lower portion of the bulb 2 due to the resistance by the buoyancy. The gas flowing to the lower portion of the bulb 2 ascends again toward the arc region, but since it is sufficiently decelerated, the disturbance of the arc and the gas around the arc can be suppressed. As a result, the swing of the arc at the cathode tip end can be suppressed. Thus, the temperature distribution of the cathode tip end surface becomes more uniform, and thus the wear of the cathode tip end becomes flat. As a result, the stable arc can be maintained for a long time.

[0046] As shown in the table shown below, the inventors further manufactured four discharge lamps of the conventional shape of the anode (without the skirt portion 48, without the tapered portion 41) with the angles of α and β changed, and compared the wear state of the cathode after lighting. In the case where α and β are 100° or less, the tip end of the cathode is not so damaged even after a long time of lighting. Figure 4A is a photograph of No. 1 electrode after lighting for 2500 hours, Figure 4B is a photograph of No. 4 electrode after lighting for 1250 hours. In this way, the former has less consumption of the tip end than the latter, although the lighting time is about twice.

[0047]

[0048] Figure 5 The voltage waveform at the time of lighting after lighting for 1250 hours is shown. In this figure, the upper waveform is the waveform of No. 4 electrode, and the lower waveform is the waveform of No. 1 electrode. In this way, in the case where the skirt portion 48 is present, the variation of the voltage is smaller than in the case where the skirt portion 48 is not present. From such a measurement result, it is known that the arc is stable in the embodiment of the present application.

[0049] Figure 6A is a mercury lamp in which α is within the range of the present application, Figure 6B is a mercury lamp in which α is outside the range. Both of the anodes 4 are of the same shape. In this way, α is outside the range due to the shape of the bulb 2. In this way, even if the anodes 4 are the same, the control of the gas flow as in the present application cannot be performed due to the shape of the bulb 2. In this way, according to the shape of the bulb 2, even the anodes of the same shape, not only the values of the angles α and β, but also the gap described later are changed.

[0050] In addition, when the tip end of the skirt portion 48 is close to the bulb 2, there is a problem that the space between the electrode and the bulb becomes small and the gas flow is difficult to flow to the upper portion of the bulb.

[0051] The area of a hollow disc formed when a line segment in the first imaginary extension line Ll from the anode 4 to the inner wall of the bulb 2 at a distance dl is axially rotated about the center line of the stem 7 is defined as S I.

[0052] In addition, a hollow disc is defined when a line segment in the first imaginary extension line Ll from the front end of the skirt 48 to the first intersection point Ql is axially rotated about the center line of the stem 7. The area of this hollow disc is defined as S2.

[0053] In the present embodiment, the distances dl and d2 are set to satisfy 0.1 < (S2 / S1) < 1. This is because, when (S2 / S1) becomes 1 or more, the air flow in the lower portion of the bulb easily becomes turbulent, and as a result, the air flow in the entire bulb easily becomes turbulent. In addition, when (S2 / S1) becomes less than 0.1, the shape of the upper and lower portions of the skirt changes too much, and vortices and the like are generated, and the air flow easily becomes turbulent, and as a result, the air flow in the entire bulb becomes turbulent.

[0054] In addition, from the viewpoint of the heat load on the bulb, it is also preferable to satisfy 5 < d2 [mm].

[0055] In the case where the shape of the first guide surface 48a of the skirt 48 is composed of a straight line, a straight line obtained by extending this straight line is defined as the imaginary extension line, but it is not limited thereto, and as shown in FIG. 6, in the case where the first guide surface 48a is composed of a curved line, a tangent line of the curved line Ra at the end portion Q41 can be defined as the first imaginary extension line Ll. Figure 2B

[0056] In the present embodiment, a straight line portion 42 that becomes a clamping region at the time of cutting is provided for easy processing, but this is not essential. In addition, the tapered portion 41 can be formed in a streamlined shape. As a combination, only the tapered portion 41 can be formed in a streamlined shape, the tapered portion 41 and the straight line portion 42 can be combined to be formed in a streamlined shape, or the tapered portion 41, the straight line portion 42, and the front end portion 46 can be combined to be formed in one streamlined shape.

[0057] In the case of a streamlined shape, an imaginary line connecting the maximum diameter portion and the minimum diameter portion is defined, and the taper angle θ is defined as the angle of this imaginary line with respect to a straight line parallel to the center line.

[0058] In addition, the taper angle θ is 5 degrees in the embodiment, but is most preferably 3 to 7 degrees, and the upper limit can also be 8 to 10 degrees. This is because, when it is greater than 10 degrees, as already explained, the cross-sectional area perpendicular to the axial direction of the rear end of the anode becomes small, and a problem such as a decrease in heat dissipation occurs. In addition, the lower limit can also be less than 3 degrees, and for example, can be about 1 degree or 2 degrees.

[0059] ​In the present embodiment, the outer shape P2 of the skirt portion 48 is made the same as the diameter PI of the largest outer diameter portion of the anode 4. Therefore, the manufacturing can be performed without increasing the amount of reduction of the sealing tube portion at the time of manufacturing. In addition, the outer shape P2 of the skirt portion 48 can also be substantially the same as the largest diameter of the main body portion 40, and can also be smaller than the largest diameter.

[0060] In the present embodiment, the short arc discharge lamp of 13.5 kW is described as an example. The effect is particularly significant in the lamp of 2 kW or more, but the range of the utility model is not limited thereto.

[0061] (2. Other Embodiments)

[0062] In the present embodiment, as shown in Figure 1B , the cross-sectional shape of the second guide surface 48b is in a circular arc shape, but can also be a shape connecting a straight line and an R shape.

[0063] In addition, the second guide surface 48b is formed as a recess in a circular ring shape on the entire surface of the bottom surface 48k. In this case, when the bottom surface of the electrode 4 is observed from the bead 9, the recess recognizes the end portions of two circles. In contrast, a plurality of recesses in a cross-sectional circular arc shape can also be provided in Figure 1C In this case, when the bottom surface of the electrode 4 is observed from the bead 9, a plurality of circles are recognized to be located on the above bottom surface.

[0064] In addition, as a modification example of the streamline shape, a large diameter portion 61 can also be provided halfway through the tapered portion 41 as shown in Figure 8A In this case, the large diameter portion 61 is provided in a convex streamline shape, but is not limited thereto, and can also be composed of a straight line. In this case, it is only necessary to make the diameter of the large diameter portion 61 the same as or smaller than the largest diameter of the main body portion 40.

[0065] In addition, as shown in Figure 8B , the tapered portion 41 can also be provided in a concave streamline shape 64.

[0066] Figure 8C An example in which the tapered portion 41 is provided in a two-stage tapered shape is shown. In the present embodiment, the taper angles are different in regions 67, 68. In this way, the tapered portion 41 can also be provided in a shape of a plurality of straight lines, curves, or a combination of both.

[0067] In addition, the connection portion of the largest diameter portion and the tapered portion can also not be smoothly connected, but can be provided with a step 77 to reduce the diameter of the electrode in stages as shown in Figure 8D Figure 8E is an example in which the front end 79 of the step is C-face machined.

[0068] In addition, as shown in​Figure 9A As shown, the tapered portion 41 can also be formed by combining the curved portion 81 and the curved portion 82.

[0069] exist Figure 1A In the anode 4, the front end of the skirt 48 is set to an acute angle shape, but it can also be like... Figure 9B As shown, the front end 85 is R-machined so that a portion of the airflow flows in the direction of arrow 86. Similarly, the front end of the skirt 48, which serves as a protrusion, can also be R-machined or C-machined. Furthermore, the front end of the second guide surface 48b of the skirt 48 can also be R-machined or C-machined.

[0070] The skirt 48 can also be composed of multiple straight or curved sections. Figure 9C An example is shown where the skirt 48 is composed of multiple straight sections 87 and 88.

[0071] exist Figure 1A In the anode 4, a second guide surface 48b with a concave shape is provided on the bottom surface 48k of the electrode, but if Figure 9D As shown, the recess on the bottom surface 48k of the electrode may not be provided, and instead it may be formed by a straight portion 92a that becomes the second guide surface 48b. In this case, the skirt portion 48 has the first guide surface 48a in a straight line shape 92b. Additionally, a cutting portion 92c is provided at the front end of the skirt portion 48, but this is not mandatory. Furthermore, as... Figure 9E As shown, the concave portion on the bottom surface 48k of the electrode may not be a circular arc in cross-section, but may be composed of a concave portion 93 on a straight line.

[0072] In this embodiment, the skirt 48 is integrally machined, but it can also be a separate structure. Specifically, as... Figure 9F As shown, the anode 4 can be formed by the main body 96 and the ring 97 including the skirt 48. To improve sealing, threads are cut on both the mating surfaces of the ring 97 and the main body 96 to screw the ring 97 into the main body 96. Thus, the anode can be formed by the main body 96 and a hollow cylindrical portion located outside the main body 96, with a protrusion provided in this hollow cylindrical portion.

Claims

1. A short-arc discharge lamp which is a vertically arranged short-arc discharge lamp, the short-arc discharge lamp comprising: a bulb having a light emitting tube portion and a sealing tube portion arranged to extend outward from both ends of the light emitting tube portion; a cathode arranged inside the light emitting tube portion; a conically shaped anode having a main body portion and a front end portion tapering toward a front end, the anode being arranged opposite the cathode, a diameter of a rear end side of the main body portion being smaller than a diameter of a front end side of the main body portion; and an anode stem supporting the anode, the anode being arranged on an upper side to be lit, characterized in that the main body portion has a protruding portion expanding in a radial direction outward with a periphery toward a rear of the anode at a rear end portion, a maximum diameter of the protruding portion being substantially the same as a maximum diameter in the main body portion, or the maximum diameter of the protruding portion being equal to or smaller than the maximum diameter in the main body portion.

2. The short-arc discharge lamp according to claim 1, characterized in that the conical shape is a straight conical shape or a streamline shape.

3. The short-arc discharge lamp according to claim 1, characterized in that the protruding portion has: a first guide surface controlling a flow of gas moving along a side surface of the anode toward a bulb direction; and a second guide surface opposite the first guide surface for controlling a convection of a stem side base surface of the anode toward the bulb direction, in a case where a tangent line in the first guide surface is defined as a first tangent line, and a tangent line at an intersection of the first tangent line and an inner side surface of a sealing body is defined as a first sealing body inner side surface tangent line, an angle of the anode front end side in an intersection angle of the anode front end side between the first tangent line and the first sealing body inner side surface tangent line is 100 degrees or less, in a case where a tangent line in the second guide surface is defined as a second tangent line, and a tangent line at an intersection of the second tangent line and an inner side surface of a sealing body is defined as a second sealing body inner side surface tangent line, an angle of the anode front end side in an intersection angle of the anode front end side between the second tangent line and the second sealing body inner side surface tangent line is 100 degrees or less.

4. The short-arc discharge lamp according to claim 1, characterized in that, in the conical shape, a taper angle defined by a straight line connecting a maximum diameter portion of the main body portion and a minimum diameter portion of the main body portion is 10 degrees or less.

5. The short-arc discharge lamp according to claim 3, characterized in that the angle of the anode front end side in the intersection angle of the anode front end side between the first tangent line and the first sealing body inner side surface tangent line and the angle of the anode front end side in the intersection angle of the anode front end side between the second tangent line and the second sealing body inner side surface tangent line are substantially equal or the former is smaller.

6. The short-arc discharge lamp according to any one of claims 1 to 4, characterized in that the main body portion is composed of a main body main body and a hollow cylindrical portion located outside the main body main body, the hollow cylindrical portion having the protruding portion. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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