JP4627350B2 - light source - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lamp having a discharge tube such as a deuterium lamp or a xenon flash lamp.
[0002]
[Prior art]
A lamp using a microwave is described in Japanese Patent Laid-Open No. 7-182910. The lamp described in the publication encloses a gas in a container and irradiates the gas with microwaves, thereby exciting the gas and generating light. The gas contains a fluorine-based gas. The fluorine-based gas etches the inner surface of the quartz glass container, and Si impurities generated by the etching adhere to the inner surface of the container. Therefore, in the lamp described in the publication, a cooling pipe is passed through the container to adsorb impurities generated by etching with fluorine gas.
[0003]
[Problems to be solved by the invention]
On the other hand, a discharge tube using arc discharge between electrodes has been known. Such discharge tubes are known. Deuterium lamps, xenon flash lamps, and the like are known as side-on type discharge tubes. A side-on type discharge tube encloses a gas such as deuterium or xenon in a container having a cylindrical side wall, and emits light emitted from the gas between the electrodes by a discharge between a pair of electrodes arranged inside the container. Output to the outside through the light exit window on the side wall.
[0004]
Since this type of discharge tube uses the discharge between the electrodes, it is not necessary to use a fluorine-based gas. Therefore, etching of the container does not occur, and it is not considered that impurities adhere to the inner surface of the container. It was.
[0005]
However, even in a discharge tube such as a deuterium lamp or a xenon flash lamp, the output light intensity decreases due to long-term use. This was initially thought to be due to the deterioration of the cathode. Of course, although the cathode deteriorates after long-term use, the present inventors have found that the main cause of the decrease in light output is not the deterioration of the cathode. In other words, it has been found that the decrease in the light output is caused by the substance released into the container adhering to the light emission window portion of the container due to sputtering of the cathode or the like accompanying the interelectrode discharge in the discharge tube. Obtained. The present invention is based on such knowledge, and an object thereof is to provide a light source capable of extending the life of a discharge tube.
[0006]
[Means for Solving the Problems]
The present invention has been made in view of the above problems, a light source according to the present invention includes a cylindrical side wall provided with the hole, the container having a protrusion communicating with the bore, heavy in said container enclosing a gas containing hydrogen, the light emission output from the gas between the electrodes by the discharge between a pair of electrodes disposed within said container, located at the top of the projecting portion communicating with said hole of said container It has a discharge tube that outputs to the outside through a light exit window, and a radiator is brought into contact with a peripheral area of the hole in the cylindrical side wall, and the radiator has a radiation block having a through hole, The protrusion is inserted into the through hole of the heat dissipating block, and includes a heat dissipating box that accommodates the discharge tube and the heat dissipating body, and the protrusion protrudes from an opening provided in the heat dissipating box. The block is the inner surface of the side wall of the heat dissipation box. Characterized in that it is fixed.
The light source includes an outer box that houses the heat radiating box, an air cooling fan that circulates air between an outer surface of the heat radiating box and the outer box, and a vent formed on a side wall of the outer box. It is characterized by providing.
[0007]
According to the present light source, light emission is output to the outside through the light emission window portion located at the tip of the protrusion extending from the predetermined portion, but the peripheral region of the predetermined portion or the surface of the protrusion other than the light emission window portion The peripheral area is cooled by the heat radiating body in contact with. Therefore, a large amount of the substance generated by sputtering or the like of the pair of electrodes constituting the cathode or the anode adheres to the peripheral region of the side wall, and the amount of the substance attached to the light exit window portion is reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the light source according to the embodiment will be described. Note that the same reference numerals are used for the same elements, and redundant description is omitted.
[0009]
FIG. 1 is a longitudinal sectional view of a light source according to the embodiment, FIG. 2 is a sectional view taken along the line II-II of the light source shown in FIG. 1, and FIG. 3 is a perspective view of the main part of the light source shown in FIG.
[0010]
The light source of the present embodiment includes an outer box 100, an inner box (heat radiating box) 101bx housed in the outer box 100, and a discharge tube 10 arranged in the inner box 101bx. The discharge tube 10 is attached to a socket SC fixed to the bottom plate of the inner box 101bx, and the outer surface of the inner box 101bx is cooled by an air cooling fan 102 provided at the top of the outer box 100. The air taken in from the air cooling fan 102 flows to the outside through the vent 100bld formed on the side wall of the outer box 100.
[0011]
In the deuterium lamp, the stability of the light output is reduced due to fluctuations in the outside air temperature. However, as in this embodiment, air is circulated between the inner box 101bx and the outer box 100 and directly flows to the deuterium lamp. Does not impair the output stability.
[0012]
The discharge tube 10 includes an airtight container (glass bulb) 1 having a cylindrical side wall 1w. A gas such as deuterium is sealed in the container 1 so as to emit ultraviolet light as output light, and the gas between the electrodes 2c and 2a is discharged by a discharge between the pair of electrodes 2c and 2a disposed inside the container 1. The emitted light is output to the outside through the light exit window 1ww.
[0013]
That is, a protruding portion 1pr extends from a predetermined portion of the side wall 1w of the container in a direction perpendicular to the tube axis of the valve, and the tip of the protruding portion 1pr forms a light emission window portion 1ww. The protrusion 1pr has a hole in the side wall 1w, and is connected to the glass tube 1pi through the glass seal ring S1 so as to communicate therewith. It is sealed with a window material 1w. Light generated inside the discharge tube is output to the outside using the window material 1ww as a light exit window.
[0014]
A heat radiating body made up of the heat radiating block 101bl and the heat radiating spring member 101sp is in contact with the surface of the peripheral region 1ws of the predetermined portion. The peripheral region 1ws is a surface region of the side wall 1w located at the base portion of the protruding portion 1pr. The discharge tube 10 is disposed in the heat radiating box 101bx and the outer box 100 for stable light emission, but since the heat radiating box 101bx and the heat radiating bodies 101sp and 101bl are thermally connected, the heat radiating box 101bx is connected to the heat radiating body 101sp. , 101bl, the heat absorbed from the discharge tube 10 is efficiently radiated to the outside, and the cooling efficiency of the peripheral region 1ws is high.
[0015]
The heat dissipation spring member 101sp will be described in detail. The spring member 101sp has a cylindrical surface that is recessed inward, and this is in contact with the surface of the peripheral region 1ws that forms the cylindrical surface that protrudes outward. The radius of curvature of the cylindrical surface of the spring member 101sp is larger than the radius of curvature of the discharge tube side wall 1w in an unloaded state, and when the spring member 101sp is pressed against the side wall 1w, the radius of curvature of the spring member 101sp becomes smaller. Elastically deforms. In an elastically deformed state, both ends in the direction along the curvature of the spring member 101sp sandwich the side surface 1w, and the central portion of the curvature urges the side surface 1w in a direction perpendicular to the tube axis of the discharge tube 10. To do. Since the bottom portion of the discharge tube 10 is fixed to the socket SC and any part of the spring member 101sp urges the side surface 1w, the degree of adhesion between the spring member 101sp and the cylindrical side wall peripheral region 1ws is improved.
[0016]
Further, the spring member 101sp has an opening 101spo through which light emitted from the discharge tube 10 propagating in the projecting part 1pr passes and the projecting part 1pr is inserted. The heat dissipating block 101bl has two parallel parallel planes, and has a through hole 101blt for inserting a protruding portion that penetrates the block 101bl so as to communicate between the openings 101blo formed in these two planes. Therefore, the heat dissipation block 101bl has an annular shape surrounding the through hole 101blt. Further, the inner box 101bx has an opening 101bxo for light emission on the side wall.
[0017]
The spring member 101sp and the annular heat dissipation block 101bl are fixed by bolts B1 and B2 so that the openings 101spo and 101blo overlap each other. The heat radiation block 101bl and the inner surface of the side wall of the inner box 101bx are fixed by bolts B11, B12, and B13 so that the respective openings 101blo and 101bxo overlap. These openings 101blo and 101bxo overlap with the opening 100op provided on the side wall of the outer box 100.
[0018]
According to this light source, light emission is output to the outside of the discharge tube through the light exit window 1ww, and light emission in the discharge tube 10 is output to the outside of the outer box 100 through the openings 101spo, 101blo, 101bxo, 100op. Is done. Since the radiator is in contact with the surface of the peripheral region 1ws, the peripheral region 1ws is cooled. Therefore, a large amount of the substance generated by sputtering of the cathode electrode 2c or the anode electrode 2a adheres to the peripheral region 1ws of the side wall 1w, and the amount of the substance attached to the light exit window 1ww decreases. That is, since the light exit window 1ww is not soiled for a long time, the life of the discharge tube can be extended.
[0019]
The radiator may be brought into contact with the glass tube 1pi, that is, the region other than the light exit window 1ww of the protruding portion 1pr.
[0020]
The discharge tube 10 is conventionally known, and this will be briefly described with reference to FIG. In the container 1 having the side wall 1w, the two electrodes 2c and 2a are arranged as described above. One of the electrodes is a cathode 2c made of a filament, and the other electrode is generated by energizing the filament 2c. It is the anode 2a which collects the thermoelectrons which did. The filament 2c is arranged in a metallic shield body 3 surrounding the filament 2c, and the thermoelectrons generated in the filament 2c are emitted toward the convergence electrode 4 through the opening of the shield body 3, and the shield body 3 and the convergence body 3 are converged. The track is bent by the electrode 4 and enters the anode 2a. The shield body 3 is attached to the light emitting side of the insulating member 5, the anode 2a is attached to the light incident side of the insulating member 5, and the shield body 3 and the anode 2a, and the shield body 3 and the filament 2c are insulated. .
[0021]
When the gas sealed in the container 1 contains deuterium, the discharge tube 10 functions as a deuterium lamp. Unlike a xenon lamp in which a high pressure xenon is enclosed, the deuterium lamp has a low temperature rise on the lamp surface. In such a lamp, the temperature difference between the cooling region 1ws and the non-cooling region 1ww due to the radiator is smaller than that of the xenon lamp, so that the deterioration of the side wall 1w due to the temperature difference is suppressed.
[0022]
The present invention can also be applied to a xenon flash lamp or a mercury xenon lamp in which xenon is enclosed in the container 1, and the electrode 2c may not be a filament.
[0023]
As described above, a large amount of the substance generated by sputtering of the cathode electrode 2c or the anode electrode 2a adheres to the peripheral region 1ws of the side wall 1w or the glass tube 1pr, so that the light exit window 1ww is long. The life of the discharge tube can be prolonged without being polluted for a period. The protrusion 1pr may be provided on the top of the container 1.
[0024]
【The invention's effect】
According to the light source of the present invention, the life of the discharge tube can be extended.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a light source according to an embodiment.
2 is a cross-sectional view of the light source shown in FIG. 1 along arrows II-II.
3 is a perspective view of a main part of the light source shown in FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Discharge tube, 101sp, 101bl ... Radiator, 101bx ... Radiation box, 1w ... Side wall, 1w ... Light emission window part, 1ws ... Peripheral area, 1pr ... Projection part.

Claims (2)

Discharge between a pair of electrodes provided inside a container, comprising a container having a cylindrical side wall provided with a hole and a projecting portion communicating with the hole, enclosing a gas containing deuterium in the container the luminescence output from the gas between the electrodes, with a discharge tube to be output to the outside through the light exit window located at the top of the projecting portion communicating with the hole of the container by,
A radiator is brought into contact with a peripheral region of the hole in the cylindrical side wall ;
The radiator has a heat dissipation block having a through hole,
The protrusion is inserted into the through hole of the heat dissipation block,
Comprising a heat dissipation box for accommodating the discharge tube and the radiator;
From the opening provided in the heat dissipation box, the protruding portion protrudes,
The heat dissipation block is fixed to the inner surface of the side wall of the heat dissipation box.
A light source characterized by that.   An outer box that houses the heat dissipation box;
  An air cooling fan for circulating air between the outer surface of the heat radiating box and the outer box;
  A vent formed in the side wall of the outer box;
The light source according to claim 1, comprising:

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