JP4721720B2 - Discharge lamp - Google Patents

Description

  The present invention relates to a discharge lamp having a pair of electrodes in a translucent envelope.

  As shown in FIG. 4, a conventional discharge lamp having a conductive foil includes a light-transmitting envelope 111 composed of a light-emitting tube portion 111a and a cylindrical sealing tube portion 111b extending from both ends of the light-emitting tube portion 111a. A pair of electrodes (positive electrode 120, negative electrode 130) arranged inside the tube portion 111a, an electrode lead rod 121 extending to the rear end side of the electrode, and fixed to the rear end side of the electrode lead rod 121 Disposed on the rear end side of the sealing body 124, the strip-shaped conductive foil 123 having one end fixed to the conductor 122, the sealing body 124 in contact with the rear end side of the conductor 122, In addition, it has a current collecting disk 125 to which one end of the conductor 123 is fixed, and an introduction line 126 fixed to the rear end side of the current collecting disk 125. Since the expansion coefficient of the conductor 122 and the sealing body 124 are greatly different, they are not welded or fixed, and the conductor 122 is supported by the conductive foil 123.

Since the expansion rate of the conductor 122 is larger than that of the sealing tube portion 111b, the conductor 122 is prevented from expanding and damaging the sealing tube portion 111b due to a temperature rise when the lamp is turned on. A minute space S is provided between 122 and the sealing tube portion 111b.
Such a discharge lamp 110 is applied with a force to tilt the conductor 122 due to the weight of the electrode (positive electrode 120 or negative electrode 130), the electrode lead rod 121, and the conductor 122 even in a stationary state. . Since the minute space S is provided between the conductor 122 and the sealing tube portion 111b, the conductor 122 tends to tilt in the minute space S by such a force, and supports the conductor 122. A tensile force is applied to the conductive foil 123. However, since the tensile force applied to the conductive foil 123 does not exceed the yield stress in the stationary state, the conductive foil 123 is not stretched or cut.
However, when vibration is applied to the discharge lamp 110 by transportation or the like, a force for further tilting the conductor 122 is applied by the vibration, and a tensile force is further applied to the conductive foil 123. As a result, as shown in FIG. 5, there is a problem that the conductive foil 123 is stretched and eventually cut.

  In order to solve this problem, a method of reducing the inclination of the conductor 122 by increasing the thickness of the conductor 122 in the axial direction has been proposed (for example, see Patent Document 1). According to such a method, as a result of the inclination of the conductor 122 being reduced, the distance by which the conductive foil 123 is pulled is shortened, so that although the conductive foil 123 is stretched, it is not cut.

Japanese Examined Patent Publication No. 4-67297

Recently, there has been a demand for an increase in the amount of radiated light in a discharge lamp. In order to increase the amount of radiation, the input current may be increased. However, when the input current is increased, the electron flow flowing between the electrodes also increases. For this reason, it is necessary to enlarge the electrode so as to withstand the increased electron current, and accordingly, it is necessary to enlarge the entire discharge lamp.
When the discharge lamp is increased in size, not only the weight of the electrode increases, but also the distance from the center of gravity of the electrode to the conductor 122 increases. For this reason, when vibration is applied to the discharge lamp, the force to incline the conductor 122 also increases, and a larger pulling force is applied to the conductive foil 123 than the conventional discharge lamp. In addition, the conductive foil 123 has a property that, when a large tensile force is applied, the conductive foil 123 can be cut slightly without being extended. For this reason, even if it is designed so that the inclination of the conductor 122 is reduced to the same extent as that of a conventional relatively small discharge lamp, when the vibration is applied to the enlarged discharge lamp, a large tensile force is applied to the conductive foil 123. Therefore, there is a problem that the conductive foil 123 can extend only slightly and is cut.

  On the other hand, when the discharge lamp is enlarged, it is necessary to increase the inner diameter of the sealing tube portion 111b with the increase in the size of the electrode. Therefore, the diameter of the conductor 122 loosely fitted in the minute space S with the sealing tube portion 111b is also increased. It needs to be bigger. As described above, the conductor 122 has a larger expansion coefficient than the sealed tube portion 111b. Therefore, when the diameter of the conductor 122 is increased, the conductor 122 is interposed between the conductor 122 and the sealed tube portion 111b. It is necessary to enlarge the micro space S provided. As the minute space S increases, the angle at which the conductor 122 tilts also increases, so the distance that the conductive foil 123 is pulled becomes longer.

For this reason, when vibration is applied to the enlarged discharge lamp, there is a problem that the conductive foil 123 cannot be extended by the longer distance, and thus is cut. For this reason, it is necessary to shorten the distance by which the conductive foil 123 is pulled. However, if the method of increasing the thickness of the conductor 122 in the axial direction as proposed in the conventional technique is used, the thickness of the conductor 122 is increased. The discharge lamp becomes larger than necessary by the amount of increase. Then, there is a problem that the entire apparatus (for example, an exposure apparatus in a liquid crystal color filter manufacturing process) incorporating a discharge lamp is increased in size. Furthermore, when the thickness of the conductor 122 is increased in the axial direction, the weight of the conductor 122 also increases. For this reason, when vibration is applied to such a discharge lamp, the pulling force applied to the conductive foil 123 also increases, so that there is a problem that the conductive foil 123 is likely to be cut.
For this reason, when the discharge lamp is increased in size, there is a problem that the conductive foil 123 cannot be prevented from being cut.
Accordingly, an object of the present invention is to provide a durable discharge lamp.

Accordingly, an invention according to claim 1 is a discharge lamp having a pair of electrodes in a translucent envelope, and an electrode lead bar extending on the rear end side of the electrode, and a back of the electrode lead bar. In the discharge lamp, comprising: a conductor that is fixedly attached to an end and is loosely fitted with an end portion of the light-transmitting envelope with a minute interval W ₁ ; and a conductive foil having one end fixed to the conductor. The conductive sealing body has a convex portion, and a concave portion that fits into the convex portion with a gap is provided on the outer periphery of the conductor, and the convex portion is composed of two side portions and a flat portion formed therebetween. Meanwhile, the recess is constituted by two sides and a flat portion formed therebetween, the spacing W ₂ between the side and the concave side of the convex portion is smaller than the small gap W ₁ Features.

  A second aspect of the present invention is the discharge lamp according to the first aspect, wherein the concave portion is provided over the entire circumference.

  A third aspect of the present invention is the discharge lamp according to the first aspect, wherein the concave portion is provided on the outer periphery of the conductor on the positive electrode side.

The invention according to claim 4 is the discharge lamp according to claim 1, wherein the minute interval W ₁ and the interval W ₂ are configured such that W ₁ > 2W _2. .

  A fifth aspect of the present invention is the discharge lamp according to the first aspect, wherein the concave portion is provided near the rear end of the conductor.

According to the first aspect of the present invention, the translucent envelope is provided with a convex portion, and a concave portion that fits into the convex portion with an interval is provided on the outer periphery of the conductor, and the convex portion has two sides. while being constituted by parts and a flat portion formed therebetween, the recess is constituted by two sides and a flat portion formed therebetween, the sides of the side and the concave portion of the convex portion Since the interval W ₂ is smaller than the minute interval W ₁ , even if the conductor is inclined due to vibration or the like, the depression of the conductor stops when the concave portion hits the convex portion, so that the conductive foil is pulled. The distance remains at a distance approximately equal to W ₂ (ie, a distance smaller than W ₁ ). Therefore, since the distance that the conductive foil is pulled can be reduced without increasing the weight of the conductor, a discharge lamp that can prevent the conductive foil from being cut even when the discharge lamp is enlarged is provided. be able to. That is, it is possible to provide a durable discharge lamp, particularly a discharge lamp that is durable against vibration.

  According to invention of Claim 2, since the recessed part is provided over the perimeter, it can process more simply.

  According to the third aspect of the present invention, since the concave portion is provided on the outer periphery of the positive electrode-side conductor, it is possible to prevent cutting of the positive electrode-side conductive foil which is heavy and applies a larger tensile force. it can.

According to the invention of claim 4, since the small gap W ₁ and spacing W ₂ is configured such that W _1> 2W _2, can be prevented more effectively cut of the conductive foil .

According to the invention of claim 5, since the recess is provided in the rear end of the conductor, it is possible to further reduce the distance W _2, to prevent more effectively cut of the conductive foil Can do.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view of the discharge lamp of the present invention, and FIG. 2 is an enlarged view of the vicinity of the conductor 22 in FIG.
The discharge lamp 10 includes a light-transmitting envelope 11 including a hollow, substantially spherical arc tube portion 11a, and a cylindrical sealing tube portion 11b extending from both ends of the arc tube portion 11a, and an inside of the arc tube portion 11a. A set of electrodes composed of the positive electrode 20 and the negative electrode 30 arranged, an electrode lead bar 21 extending to the rear end side of the electrode, and the transparent electrode fixed to the rear end side of the electrode lead bar 21. A conductor 22 that loosely fits at a small interval W ₁ with the sealing tube portion 11b that is an end of the optical sealing body 11, a sealing body 24 that contacts the rear end side of the conductor 22, and a rear end of the sealing body 24 Current collector disk 25 arranged on the side, lead wire 26 fixed to the rear end side of current collector disk 25, and the periphery of sealing body 24, both ends of conductor 22 and collector And a conductive foil 23 fixed to the electric disk 25.

The positive electrode 20 and the negative electrode 30 are formed in a shape in which a cone or a part of a cone cut perpendicularly to an axis and a cylinder are combined.
The electrode lead bar 21 is formed in a round bar shape. The external terminal 27 may have an arbitrary shape depending on the mounting shape of the device. As the lead-in wire 26 for connecting the current collecting disk 25 and the external terminal 27, a round bar or a flexible conductive lead wire is used. The external terminal 27 and the sealing tube portion 11b are fixed using a conventionally known technique such as cement.
The electrode lead rod 21 and the lead-in wire 26 are attached to holes provided at the centers of the positive electrode 20, the negative electrode 30, the conductor 22, and the current collecting disk 25, respectively, and are electrically conductive by means such as welding. It is fixed. The external terminal 27 and the lead-in wire 26 are also conductively fixed by means such as welding.
The external terminal 27 is formed in a metal cap shape. The inner diameter of the external terminal 27 and the outer diameter of the sealing tube portion 11b are configured such that the inner diameter of the external terminal 27 is larger. A through hole for penetrating the lead-in wire 26 is formed at the center of the external terminal 27. Note that the gap between the lead-in wire 26 and the through hole of the external terminal 27 is sealed in a conductive state by welding.
A plurality of strip-like conductive foils 23 extending in the axial direction along the peripheral surface are disposed on the peripheral surface of the sealing body 24. The plurality of conductive foils 23 are arranged over substantially the entire circumference of the sealing body 24 at intervals of usually about 1 mm. The number of conductive foils 23 to be disposed is usually about three. The conductive foil 23, the conductor 22, and the current collecting disk 25 are each conductively fixed by welding or the like.

The width and length of the conductive foil 23 may be appropriately set according to the shape of the conductor 22, etc., but the width is usually about 8 mm to 30 mm, and the length is usually about 25 mm to 150 mm. The thickness of the conductive foil 23 is usually about 20 μm to 60 μm.
The sealing body 24 and the sealing tube portion 11b are fitted through the conductive foil 23 therebetween, and the discharge lamp 10 is sealed by welding the sealing body 24 and the sealing tube portion 11b. Although it is (sealed), the conductive foil 23 enables conduction. The discharge lamp 10 has such a foil seal structure.
The conductor 22 has a larger expansion coefficient than the sealed tube portion 11b. Therefore, in order to prevent the conductor 22 from expanding and damaging the sealing tube portion 11b due to a temperature rise when the lamp is turned on, a minute gap W ₁ is provided between the conductor 22 and the sealing tube portion 11b. Is provided.
The conductor 22 and the sealing body 24 are not welded or fixed because of their large expansion coefficients.
The conductor 22 is supported by a conductive foil 23.

Then, and has a recess G on the outer periphery of the conductor 22, the translucent sealing member 11 has a convex portion P, which mates with an interval W ₂ in the recess G.
The concave portion G provided on the outer periphery of the conductor 22 can be processed by a conventionally known method such as a lathe method.
The convex portion P provided on the translucent envelope 11 can be processed by the same method as the step of heating and sealing the sealing tube portion 11b of the translucent envelope 11, and usually an oxyhydrogen burner is used. Processed by using and heating. Thus, the shape of the convex portion P provided on the translucent sealing member 11 is determined according to the shape of the concave portion G provided on the outer periphery of the conductor 22 that mates with this and spacing W _2.

The recess G provided on the outer periphery of the conductor 22 is provided over the entire periphery. The recess G may be provided at least at a part of the outer periphery of the conductor 22, and when provided at a part of the outer periphery of the conductor 22, a plurality of the recesses G are preferably provided at equal intervals in the circumferential direction. It is more preferable to provide four or more at equal intervals in the direction. Further, since the recess G is provided over the entire circumference, it is easy to process, and it is easy to process to provide the projecting portion P that fits the translucent envelope 11 with the recess G with a distance W _2. The translucent envelope 11 is preferable in that it is difficult to break.
The recess G is provided near the rear end of the conductor 22. The concave portion G is preferably provided from the rear end in order to reduce the interval W ₂ to suppress the inclination of the conductor 22 and to prevent the conductive foil 23 from being cut.

  The concave portion G is provided on the outer periphery of the conductor 22 on the positive electrode 20 side. The concave portion G may be provided on the outer periphery of either the conductor 22 on the positive electrode 20 side or the conductor 22 on the negative electrode 30 side, or may be provided on the conductor 22 on the positive electrode 20 side and the conductivity on the negative electrode 30 side. You may provide in the outer periphery of both of the body 22. FIG. Since the positive electrode 20 is heavier than the negative electrode 30, a larger tensile force is applied to the positive electrode side conductive foil 23, so that the positive electrode side conductive foil 23 is more easily cut. Therefore, the concave portion G is preferably provided on the outer periphery of the conductor 22 on the positive electrode 20 side.

The translucent envelope 11 including the arc tube portion 11a and the sealing tube portion 11b is made of a conventionally known material such as quartz glass.
The positive electrode 20 and the negative electrode 30 are made of a material suitable for discharge, and are usually made of a high melting point metal such as tungsten.
The electrode lead bar 21 is made of a conductive material and is usually made of tungsten.
The conductor 22 is made of a conductive material and is usually made of molybdenum.
The conductive foil 23 is made of a conductive material and is usually made of molybdenum.
The sealing body 24 is formed of a material having an expansion coefficient close to that of the translucent sealing body 11 and suitable for sealing, and is usually formed of quartz glass.
The current collecting disk 25 is made of a conductive material and is usually made of molybdenum.
The lead-in wire 26 is made of a conventionally known conductive material.

Examples of the discharge lamp of the present invention include a discharge lamp having a foil seal structure, and includes an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, and the like. Of these, an ultrahigh pressure mercury lamp and a high pressure mercury lamp are preferable. Moreover, it is preferable that it is a short arc type discharge lamp.
The configurations of the discharge lamp 10 of the present invention other than the conductor 22 and the translucent envelope 11 can be configured in the same manner as a conventionally known discharge lamp.

In FIG. 2, the symbol A represents the thickness of the conductor 22. A symbol B represents a distance from the rear end portion of the conductor 22 to the recess G. Reference symbol C represents the width of the bottom of the recess G provided in the conductor 22. A symbol D represents the diameter of the conductor 22. Reference symbol E is the depth of the recess G provided in the conductor 22. The symbols α ₁ and α ₂ represent the angles of the side surfaces of the recess G provided in the conductor 22.
The symbol W ₁ is provided between the conductor 22 and the sealing tube portion 11b in order to prevent the conductor 22 from expanding and damaging the sealing tube portion 12 due to a temperature rise when the lamp is turned on. Represents a minute interval .
A symbol W ₂ represents an interval provided between the concave portion G provided on the outer periphery of the conductor 22 and the convex portion P provided on the translucent seal 11.

The minute interval W ₁ and the interval W ₂ are configured to satisfy W ₁ > W ₂ . W ₁ > 2W ₂ is preferable in order to prevent the conductive foil 23 from being cut by suppressing the inclination of the conductor 22 and shortening the distance by which the conductive foil 23 is pulled.
The minute interval W ₁ provided between the conductor 22 and the sealing tube portion 11b is appropriately set according to the difference in the expansion coefficient between the conductor 22 and the sealing tube portion 11b, the diameter of the conductor portion 22, and the like. However, when the diameter of the conductor portion 22 is 20 mm, it is usually about 200 μm, and when the diameter of the conductor portion 22 is 50 mm, it is usually about 500 μm. That is, it is provided at an interval considering the temperature during operation.
The interval W ₂ provided between the concave portion G provided on the outer periphery of the conductor 22 and the convex portion P provided on the translucent envelope 11 is preferably 20 μm or more and 100 μm or less, and is usually about 50 μm. is there.

The thickness A of the conductor 22 is preferably equal to or greater than the diameter D of the conductor 22 in that the moment applied to the conductive foil 23 during processing is reduced. Furthermore, if the thickness A of the conductor 22 is too long during processing with the oxyhydrogen burner, it becomes difficult to control the temperature when the temperature of the conductor 22 is increased as a whole when setting the interval W1. Therefore, it is desirable that the thickness A of the conductor 22 is not more than 5 times the distance B from the rear end portion of the conductor 22 to the recess G.
The distance B from the rear end of the conductor 22 to the recess G is preferably 3 mm or more and 20 mm or less. If it is less than 3 mm, there is a problem that it is difficult to fix the conductive foil 23. If it exceeds 20 mm, an increase in the distance B from the rear end portion of the conductor 22 to the recess G due to the expansion of the conductor 22 due to the temperature rise when the discharge lamp 10 is lit increases, so the interval W ₂ needs to be increased. Arise. As a result, the inclination of the conductor 22 when vibration is applied to the discharge lamp 10 is increased, and therefore the distance that the conductive foil 23 is pulled becomes longer, so that the cutting of the conductive foil 23 cannot be effectively prevented. There's a problem.

The width C of the bottom of the recess G provided in the conductor 22 is preferably 3 mm or more and 10 mm or less. If the thickness is less than 3 mm, there is a problem that it becomes difficult to provide the translucent sealing body 11 with the convex portion P that fits in the concave portion G with the interval W ₂ .
The diameter D of the conductor 22 is substantially determined by the lighting current value of the discharge lamp and may be set as appropriate, but is usually 14 mm or more and 50 mm or less.
The depth E of the recess G provided in the conductor 22 is preferably 0.5 mm or more and 1 mm or less. If the thickness is less than 0.5 mm, the concave portion G provided on the outer periphery of the conductor 22 and the convex portion P provided on the translucent seal 11 cannot be fitted sufficiently, and the inclination of the conductor 22 There is a problem that it becomes difficult to prevent the conductive foil 23 from being cut. When it is larger than 1 mm, there is a problem that it becomes difficult to provide the translucent envelope 11 with the convex portion P that fits into the concave portion G with a gap W ₂ .

The angles α ₁ and α ₂ of the side surfaces of the recesses G provided in the conductor 22 are preferably greater than 55 ° and smaller than 75 °. If the angle is 55 ° or less, the concave portion G provided on the outer periphery of the conductor 22 and the convex portion P provided on the translucent seal 11 cannot be fitted sufficiently, and the inclination of the conductor 22 can be reduced. There is a problem that it becomes difficult to suppress and it becomes difficult to prevent the conductive foil 23 from being cut after all. When it is 75 ° or more, not only is it difficult to process the convex portion P that fits the concave portion G with the interval W ₂ in the translucent envelope 11, but also the convex portion P provided in the translucent envelope 11. There is a problem that cracks are likely to occur at the base of the substrate.

FIG. 3 is a diagram showing the effect of the discharge lamp 10 of the present invention, in which the vicinity of the conductor 22 is enlarged.
When vibration is applied to the discharge lamp 10 of the present invention, since the minute interval W ₁ is provided between the conductor 22 and the sealing tube portion 11b, the electrode (positive electrode 20 or negative electrode 30), electrode lead A force for inclining the conductor 22 is applied by the weight of the rod 21 and the conductor 22, and a tensile force is applied to the conductive foil 23 supporting the conductor 22.
Even inclined the conductive member 22 by such a tensile force, which has a recess G on the outer periphery of the conductor 22, closed in the translucent sealing member 11, the convex portion P, which mates with an interval W ₂ in the concave portion G In addition, since the minute interval W ₁ and the interval W ₂ are configured to satisfy W ₁ > W ₂ , the inclination of the conductor 22 stops when the concave portion G hits the convex portion P. The distance by which the conductive foil 23 is pulled remains approximately equal to W ₂ (ie, a distance smaller than W ₁ ).
For this reason, according to the discharge lamp 10 of the present invention, even when a large tensile force is applied to the conductive foil 23, the conductive foil 23 is not cut because the pulling distance is short.

As an embodiment of the high-pressure discharge lamp 10 of the present invention, for example, a discharge lamp having a pair of electrodes composed of a positive electrode 20 and a negative electrode 30 in a translucent envelope 11, the rear end of the electrode An electrode lead bar 21 extended to the side, and a conductor 22 fixed to the rear end side of the electrode lead bar 21 and loosely fitted with an end portion of the light-transmitting envelope 11 with a minute interval W ₁ ; in the discharge lamp and a conductive foil 23 which is secured at one end to the conductor conductor 22, which has a recess G on the outer periphery of the conductor 22, the the transparent bulb 11, with an interval W ₂ in the concave portion G It has convex portions P that fit together, and is configured such that the minute interval W ₁ and the interval W ₂ satisfy W ₁ > W ₂ .
Further, the concave portion G is configured to be provided over the entire circumference.
Further, the concave portion G is configured to be provided on the outer periphery of the conductor 22 on the positive electrode 20 side.
In addition, the minute interval W ₁ and the interval W ₂ are configured to satisfy W ₁ > 2W ₂ .
In addition, the concave portion G is configured to be provided near the rear end of the conductor 22.

  In addition, this invention is not limited to the above-mentioned example.

It is sectional drawing of the discharge lamp of this invention. FIG. 2 is an enlarged view of the vicinity of a conductor of the discharge lamp of FIG. 1. It is a figure which shows the effect of the discharge lamp of this invention. It is sectional drawing of the conventional discharge lamp. It is a figure which shows the effect of the conventional discharge lamp.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Discharge lamp 11 Translucent enclosure 11a Light emission tube part 11b Sealing tube part 20 Positive electrode 21 Electrode lead rod 22 Conductor 23 Conductive foil 24 Sealing body 25 Current collecting disk 26 Lead wire 27 External terminal 30 Negative electrode A Thickness B Distance C Width D Diameter E Depth G Concave P Convex W ₁ Minute interval W ₂ Distance α ₁ , α ₂ Angle

Claims (5)

A discharge lamp having a pair of electrodes in a translucent envelope,
An electrode lead rod extending on the rear end side of the electrode, and a conductor fixedly attached to the rear end side of the electrode lead rod and loosely fitted with an end portion of the translucent envelope at a minute interval W ₁ ; In a discharge lamp comprising a conductive foil having one end fixed to the conductor,
The translucent envelope is provided with a convex portion, and a concave portion that fits into the convex portion with a gap is provided on the outer periphery of the conductor, and the convex portion is formed by two side portions and a flat portion formed therebetween. while the configuration, the recess is constituted by two sides and a flat portion formed therebetween, the spacing W ₂ between the side and the concave side of said convex portion from the small gap W ₁ A discharge lamp characterized by being small.   The discharge lamp according to claim 1, wherein the recess is provided over the entire circumference.   The discharge lamp according to claim 1, wherein the concave portion is provided on an outer periphery of the conductor on the positive electrode side. Discharge lamp according to claim 1, wherein a small gap W ₁ and the distance W ₂ is configured such that W _1> 2W ₂   The discharge lamp according to claim 1, wherein the recess is provided near a rear end of the conductor.

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