JP2021118082A - Hot cathode lamp - Google Patents

Abstract

To provide a hot cathode lamp in which the breakage of an end of a filament can be suppressed when the end of a filament is pinched with wells.SOLUTION: A hot cathode lamp according to an embodiment includes a cylindrical tube and an electrode provided at each of ends on both sides of the tube. The electrode includes: a filament which is provided in the infernal space of the tube, and has a coil and a leg that is provided at each of ends on both sides of the coil, the leg having a spirally wound wire; a pair of wells each having a bent part sandwiching the leg; and a relaxation part which is provided between the bent part and the leg and is easier in elastic deformation or plastic deformation than the leg.SELECTED DRAWING: Figure 6

Description

Embodiments of the present invention relate to hot cathode lamps.

There is a hot cathode lamp provided with a tubular tube made of glass or the like and electrodes provided at the ends on both sides of the tube. The electrode is provided with a filament and linear wells that hold the ends on both sides of the filament. When holding the ends on both sides of the filament, the vicinity of the ends of the wells is bent so as to sandwich the ends on both sides of the filament.

Here, some filaments have a so-called double coil structure, triple coil structure, quadruple coil structure, or the like. The end of the filament having these structures has a structure in which a wire rod is spirally wound. Therefore, the portion in which the wire rod is spirally wound is sandwiched between the wells and held. Since the portion where the wire is spirally wound is easily damaged by an external force, it is necessary to strictly control the force received by the end of the filament when the end of the filament is sandwiched by the wells. As a result, productivity has decreased, yield has decreased, and manufacturing costs have increased.
Therefore, it has been desired to develop a hot cathode lamp capable of suppressing damage to the end of the filament when the end of the filament is sandwiched by wells.

Japanese Unexamined Patent Publication No. 2011-44421

An object to be solved by the present invention is to provide a hot cathode lamp capable of suppressing damage to the end portion of the filament when the end portion of the filament is sandwiched by wells.

The hot cathode lamp according to the embodiment includes a tube having a tubular shape; and electrodes provided at both end portions of the tube. The electrode is provided in the internal space of the tube and is provided with a coil and a filament having a leg provided at each of both end portions of the coil and having a spirally wound wire; It has a pair of wells having a bent portion; and a relaxing portion provided between the bent portion and the leg and which is more easily elastically deformed or plastically deformed than the leg.

According to an embodiment of the present invention, it is possible to provide a hot cathode lamp capable of suppressing damage to the end portion of the filament when the end portion of the filament is sandwiched by wells.

It is a schematic partial cross-sectional view for exemplifying the hot cathode lamp which concerns on this embodiment. It is a schematic side view which looked at the hot cathode lamp in FIG. 1 from the A direction. It is a schematic enlarged view of the part B in FIG. (A) is a schematic front view for exemplifying the holding structure of the filament according to the comparative example. (B) is a schematic side view for exemplifying the holding structure of the filament according to the comparative example. (A) is a schematic front view for exemplifying a state before formation of a bent portion. (B) is a schematic side view for exemplifying the state before the formation of the bent portion. (A) is a schematic front view for exemplifying the state after the formation of the bent portion. (B) is a schematic side view for exemplifying the state after the formation of the bent portion. It is a schematic side view for exemplifying the relaxation part which concerns on other embodiment. (A) to (d) are schematic cross-sectional views for exemplifying the contact relationship between the relaxation portion, the leg, and the bending portion.

Hereinafter, embodiments will be illustrated with reference to the drawings. In each drawing, similar components are designated by the same reference numerals and detailed description thereof will be omitted as appropriate.
In the following, as an example, a hot cathode lamp having a tube (straight tube) extending in a straight line is illustrated, but the appearance of the tube is not limited to this. For example, the appearance of the tube may be annular (for example, annular), U-shaped, spiral, or a plurality of tubes joined by a bridge.

FIG. 1 is a schematic partial cross-sectional view for exemplifying the hot cathode lamp 1 according to the present embodiment.
FIG. 2 is a schematic side view of the hot cathode lamp 1 in FIG. 1 as viewed from the A direction.
FIG. 3 is a schematic enlarged view of part B in FIG.

As shown in FIGS. 1 to 3, the hot cathode lamp 1 may be provided with a tube 10, a base 20, and an electrode 30.
The tube 10 has a tubular shape and can be formed of a material having heat resistance and translucency. The material of the tube 10 can be, for example, quartz, glass, or the like. The glass can be, for example, soda lime glass containing sodium oxide, hard glass, or the like. By using soda lime glass, it is possible to reduce the cost and obtain a transmittance of 80% or more in light having a wavelength near 340 nm. If hard glass is used, the transmittance of light having a wavelength near 340 nm can be further improved.

The dimensions of the tube 10 are not particularly limited. For example, the outer diameter of the tube 10 can be about 14 mm to 38 mm. For example, the wall thickness of the tube 10 can be about 0.4 mm to 1.0 mm. For example, the length of the tube 10 can be about 135 mm to 2400 mm.

Further, a discharge medium can be sealed in the internal space of the tube 10. The discharge medium can be, for example, a noble gas and mercury. The rare gas can be, for example, argon gas, mixed rare gas, or the like. The gas pressure (filling pressure of the noble gas) at 25 ° C. in the internal space of the tube 10 can be, for example, about 1 Torr (133.322 Pa) to 10 Torr (1333.22 Pa). The pressure of the gas at 25 ° C. in the internal space of the tube 10 can be determined from the standard state of gas (SATP (Standard Ambient Temperature and Pressure): temperature 25 ° C., 1 bar). The amount of mercury enclosed can be, for example, about 1 mg to 10 mg.

Further, a protective film can be provided on the inner wall of the tube 10. The protective film can be provided, for example, to prevent mercury from reaching the inner wall of the tube 10. If mercury can be suppressed from reaching the inner wall of the tube 10, it is possible to suppress a decrease in the transmittance of the tube 10. Therefore, it is possible to suppress the decrease in illuminance over time. The protective film can be, for example, a film containing aluminum oxide or silicon dioxide. The thickness of the protective film can be, for example, about 0.5 μm to 5 μm.

The phosphor film can be provided on the surface of the protective film opposite to the inner wall side of the tube 10. The thickness of the phosphor film can be, for example, about 5 μm to 30 μm.

Here, when an electric current is passed through one of the electrodes 30 (cathode), the coil 33a of the filament 33 is heated. Then, thermions are emitted from the emitter 34 held by the coil 33a having a temperature of about 600 ° C. to 1100 ° C. The emitted electrons move to the other electrode 30 (anode) side, so that a discharge occurs. The emitted electrons collide with the enclosed mercury atom in the internal space of the tube 10. When an electron collides with a mercury atom, the mercury atom receives the energy of the electron and emits ultraviolet rays having a peak wavelength of about 253.7 nm. If the phosphor film is not provided, the generated ultraviolet rays are irradiated to the outside of the tube 10. If the phosphor film is provided, the generated ultraviolet rays are incident on the phosphor film, and the fluorescence (for example, visible light) generated in the phosphor film is irradiated to the outside of the tube 10. Further, if the phosphor film contains an ultraviolet light emitting phosphor, the illuminance of the ultraviolet rays emitted from the hot cathode lamp 1 can be increased.

Therefore, the phosphor film can be appropriately provided depending on the application of the hot cathode lamp 1. Further, the wavelength of fluorescence generated in the phosphor film can be appropriately changed depending on the type of phosphor. Since a known phosphor can be used as the phosphor that generates visible light, detailed description thereof will be omitted. The ultraviolet emitting phosphor can be, for example, YPO ₄ : Ce, SrB ₄ O ₇ : Eu, or the like.

Further, in order to improve the film strength of the phosphor film, a binder may be further included in the phosphor film. The binder may be, for example, a borate-based binder, a calcium-based binder, an aluminum oxide-based binder, or the like. One type of binder may be used, or a plurality of types of binders may be used. In addition, aluminum oxide can be added to the phosphor film in order to improve the discharge delay in the dark.

The base 20 can be provided at each of the ends on both sides of the tube 10. The base 20 can be fixed to the end of the tube 10 with a bonding agent. As shown in FIG. 2, inside the base 20, a connecting portion 21 for electrically connecting the wells 32 of the electrode 30 and an external device is provided. The number of connections 21 can be the same as the number of wells 32. The connecting portion 21 can be formed from a conductive material such as metal. Wells 32 of the electrode 30 can be electrically connected to the end of the connecting portion 21 on the tube 10 side.

The connecting portion 21 illustrated in FIG. 2 has a tubular shape. Inside the tubular connection portion 21, a pin-shaped terminal provided in an external device can be inserted. The connecting portion 21 may have a pin shape, and one end side may protrude from the end surface of the base 20. In this case, the pin-shaped connecting portion 21 can be inserted into the tubular terminal provided in the external device.

Electrodes 30 can be provided at each of the ends on both sides of the tube 10.
As shown in FIG. 3, the electrode 30 can have a base 31, wells 32, filament 33, emitter 34, ribbon 35, and relaxation section 36.

The base 31 may have a flare portion 31a and a sealing portion 31b. The flare portion 31a and the sealing portion 31b can be integrally formed. For example, the material of the flare portion 31a and the sealing portion 31b can be the same as the material of the tube 10.

The flare portion 31a may have a funnel shape. The enlarged diameter end of the flare portion 31a can be joined to the end of the tube 10. By joining the flare portion 31a to the end portion of the tube 10, the internal space of the tube 10 can be made airtight.

The sealing portion 31b can be provided at the end portion of the flare portion 31a on the side opposite to the diameter-expanded side. For example, the sealing portion 31b can be formed by inserting a pair of wells 32 inside a tubular member and crushing the heated tubular member together with the pair of wells 32 (sealing wells 32b). For example, the sealing portion 31b can be formed by using a pinch sealing method or the like.

A pair of wells 32 can be provided at one electrode 30. Wells 32 can have outer wells 32a, sealed wells 32b, and inner wells 32c.

Outer Wells 32a has a linear shape. The wire diameter of the outer wells 32a can be, for example, about 0.5 mm. One end of the outer wells 32a can be joined to one end of the sealing wells 32b. The other end of the outer wells 32a can be electrically connected to the connecting portion 21 of the base 20. Outer Wells 32a can be, for example, a wire rod containing iron plated with copper and tin.

The sealing wells 32b are linear. The wire diameter of the sealing wells 32b can be, for example, about 0.4 mm. The sealing wells 32b can be provided inside the sealing portion 31b. As described above, when forming the sealing portion 31b, the heated tubular member is crushed together with the pair of sealing wells 32b. Therefore, it is preferable that the coefficient of linear expansion of the material of the sealing wells 32b is close to the coefficient of linear expansion of the material of the sealing portion 31b. The sealing wells 32b can be made, for example, obtained by subjecting a wire rod containing an iron-nickel alloy to copper plating and nickel plating to form a suboxide film on the outer surface thereof.

The inner wells 32c has a linear shape. The wire diameter of the inner wells 32c can be, for example, about 0.8 mm. As shown in FIGS. 8 (c) and 8 (d) described later, the inner wells 32c may be crushed so as to have a flat cross section. In this case, the thickness of the inner wells 32c can be about 0.6 mm. One end of the inner wells 32c can be joined to the other end of the sealing wells 32b. As will be described later, a bent portion 32c1 is provided in the vicinity of the other end portion of the inner wells 32c. The bent portion 32c1 can be formed by bending the vicinity of the other end portion of the inner wells 32c. The relaxation portion 36 and the filament 33 (leg 33b) are held by the wells 32 by being sandwiched by the bent portion 32c1. Has been done.

The filament 33 is provided in the internal space of the tube 10. The filament 33 can have a coil 33a and a leg 33b. The coil 33a and the leg 33b can be integrally formed. Legs 33b can be provided at each of the ends on both sides of the coil 33a. The leg 33b can be formed by winding a wire rod in a spiral shape. The coil 33a can be a spirally wound wire rod further spirally wound. The wire rod may contain, for example, tungsten, a renium-tungsten alloy, or the like. The wire diameter of the wire rod can be, for example, about 15 μm to 95 μm.

For example, the filament 33 may have a so-called double coil structure, triple coil structure, or quadruple coil structure. However, the filament 33 is not limited to those having a double coil structure, a triple coil structure, or a quadruple coil structure. The filament 33 may be provided with a leg 33b having a wire rod wound in a spiral shape.

For example, in the case of a filament 33 having a double coil structure, a portion to be a leg 33b is formed by spirally winding a wire rod, and a spirally wound wire rod is further spirally wound to form a coil 33a. Part can be formed. In the case of a filament having a triple coil structure or a filament having a quadruple coil structure, the number of windings can be further increased.

The emitter 34 can be provided on the coil 33a. The emitter 34 can be formed by applying a mixture of BaO, SrO, and CaO having a low work function to the coil 33a. _{Further, ZrO 2 and the} like can be further added to the mixture in order to suppress the evaporation of the material of the emitter 34. If the emitter 34 is provided, the starting voltage and the tube voltage can be reduced.

Further, since the coil 33a is a spirally wound wire rod further spirally wound, the amount of material retained by the emitter 34 can be increased. Therefore, the life of the emitter 34 can be extended, and the life of the hot cathode lamp 1 can be extended.

The ribbon 35 can be a foil having a rectangular planar shape. One end of the ribbon 35 can be joined to one of the pair of bent portions 32c1. The other end of the ribbon 35 can be joined to the other of the pair of bent portions 32c1. The ribbon 35 is a source of mercury emission. The ribbon 35 may contain, for example, a mercury alloy (for example, a mercury-titanium alloy), zirconium, aluminum, or the like.

Here, before explaining the relaxation unit 36, the holding structure of the filament 33 according to the comparative example will be described.
FIG. 4A is a schematic front view for exemplifying the holding structure of the filament according to the comparative example.
FIG. 4B is a schematic side view for exemplifying the holding structure of the filament according to the comparative example.
As shown in FIGS. 4A and 4B, the relaxation portion 36 is not provided in the holding structure of the filament 33 according to the comparative example. Therefore, the leg 33b is directly sandwiched between the bent portions 32c1. As described above, the leg 33b has a spirally wound wire rod. When a spirally wound wire is sandwiched, damage is more likely to occur than when a simple wire is sandwiched. Therefore, it is necessary to strictly control the force received by the leg 33b when the leg 33b is sandwiched by the bent portion 32c1. As a result, productivity may decrease, yield may decrease, and manufacturing cost may increase.

Therefore, the hot cathode lamp 1 according to the present embodiment is provided with a relaxation unit 36.
FIG. 5A is a schematic front view for exemplifying a state before the formation of the bent portion 32c1. FIG. 5B is a schematic side view for exemplifying the state before the formation of the bent portion 32c1.
FIG. 6A is a schematic front view for exemplifying the state after the formation of the bent portion 32c1. FIG. 6B is a schematic side view for exemplifying the state after the formation of the bent portion 32c1.
As shown in FIGS. 5A and 5B, the relaxation portion 36 can be provided on the inner wells 32c. Then, as shown in FIGS. 6A and 6B, when the bending portion 32c1 is formed by bending the vicinity of the tip of the inner wells 32c, the relaxation portion 36 and the leg 33b can be sandwiched by the bending portion 32c1.

Here, the relaxation portion 36 can be made easier to be elastically deformed or plastically deformed than the leg 33b. For example, the material of the relaxation portion 36 can be a conductive material having a hardness lower than that of the leg 33b and having a melting point of 1000 ° C. or higher. For example, the material of the relaxation portion 36 can be nickel, platinum, copper, molybdenum, platinum-plated molybdenum, iron-nickel alloy, or the like. However, the material of the relaxation unit 36 is not limited to the one provided as an example.

The thickness of the relaxation portion 36 can be, for example, 0.01 mm or more and 0.2 mm or less.
If a relaxation portion 36 that is more easily elastically deformed or plastically deformed than the leg 33b is provided between the bent portion 32c1 and the leg 33b, the stress applied to the leg 33b including the spirally wound wire rod is applied. It can be relaxed. Therefore, it is possible to prevent the leg 33b from being damaged when the leg 33b is sandwiched by the bent portion 32c1, and it is possible to improve the yield. For example, in the case of the holding structure of the filament 33 according to the comparative example, the leg 33b was damaged at a ratio of 3/2000, but by providing the relaxation portion 36, the damage of the leg 33b is reduced to 0/2000. I was able to.

The relaxation unit 36 can be a cylinder, for example, as illustrated in FIGS. 5 (a) to 6 (b). Further, the relaxation portion 36 may be a cylinder having a C-shaped cross section, a cylinder having a slit (cut) extending in the axial direction, or the like. If a cylinder having a C-shaped cross section, a cylinder having a slit (cut) extending in the axial direction, or the like is used, elastic deformation or plastic deformation of the relaxation portion 36 becomes easy. Further, the sheet-shaped relaxation portion 36 may be used. If the sheet-shaped relaxation portion 36 is used, elastic deformation or plastic deformation of the relaxation portion 36 becomes easier.

If a cylinder, a cylinder having a C-shaped cross section, a cylinder having a slit (cut) extending in the axial direction, or the like is used, the inner wells 32c can be inserted inside the relaxation portion 36, so that the bent portion 32c1 is formed. At that time, it is possible to prevent the relaxation unit 36 from falling off. When the sheet-shaped relaxation portion 36 is used, the sheet-shaped relaxation portion 36 can be joined in the vicinity of the tip of the inner wells 32c.

FIG. 7 is a schematic side view for exemplifying the relaxation unit 36a according to another embodiment.
The relaxation portion 36 illustrated in FIGS. 5A to 6B is provided between one side of the leg 33b and the bending portion 32c1. On the other hand, the relaxation portion 36a illustrated in FIG. 7 is provided between one side of the leg 33b and the bending portion 32c1 and between the other side of the leg 33b and the bending portion 32c1. .. For example, the axial length of the relaxation portion 36a can be longer than the axial length of the relaxation portion 36. If the relaxation portion 36a is used, it becomes easier to relax the stress applied to the leg 33b.

8 (a) to 8 (d) are schematic cross-sectional views for exemplifying the contact relationship between the relaxation portions 36, 36a, the leg 33b, and the bent portion 32c1.

As shown in FIGS. 8A and 8B, the cross-sectional shape of the bent portion 32c1 can be a circle. Further, as shown in FIGS. 8C and 8D, the surface of the bent portion 32c1a on the leg 33b side can be a flat surface. As described above, the bent portion 32c1a can be formed by crushing the inner wells 32c having a circular cross-sectional shape. If the surface on the leg 33b side is a flat surface, the contact area between the relaxation portions 36, 36a and the leg 33b can be increased. Therefore, the stress applied to the leg 33b can be further relaxed. In addition, the reliability of the electrical connection between the bent portion 32c1 and the leg 33b can be improved.

Although some embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof. Moreover, each of the above-described embodiments can be implemented in combination with each other.

1 Hot Cathode Lamp, 10 Tubes, 30 Electrodes, 31 Bases, 32 Wells, 32a Outer Wells, 32b Encapsulation Wells, 32c Inner Wells, 32c1 Bends, 32c1a Bends, 33 Filaments, 33a Coil, 33b Legs, 34 Emitters, 36 relaxation part, 36a relaxation part,

Claims (3)

With a tubular tube;
With electrodes provided at each of the ends on both sides of the tube;
Equipped with
The electrode is
A filament having a coil provided in the internal space of the tube and a leg provided at each of the ends on both sides of the coil and having a spirally wound wire;
With a pair of wells having bends that sandwich the leg;
A relaxation portion provided between the bent portion and the leg, which is more easily elastically deformed or plastically deformed than the leg;
A hot cathode lamp with. The hot cathode lamp according to claim 1, wherein the material of the relaxation portion has a hardness lower than that of the material of the leg. The hot cathode lamp according to claim 1 or 2, wherein the surface of the bent portion on the leg side is a flat surface.

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