JPS5810363A - Short-arc-type high presssure electric-discharge lamp - Google Patents

Abstract

PURPOSE:To enable a short-arc-type high pressure electric-discharge lamp to be used in various form by combining the lamp with a lens system, a reflecting mirror or the like by projecting produced light through the optical windows of a sealed body toward opposite directions. CONSTITUTION:Metallic terminal rings 4 and 5 are fused to both ends of a cylindrical sealed body 1 both ends of which are opened. Metallic window-supporting members 6 and 7, respectively, are fused to the terminal rings 4 and 5. The window-supporting members 6 and 7 have ring-like shapes, and optical windows 8 and 9 are fused to the central openings of the members 6 and 7. A short arc is produced between both electrodes 13 and 14 by supplying electric power from the terminal rings 4 and 5, and light obtained by the arc discharge is transmitted by the optical windows 8 and 9 and projected toward opposite direction. As a result, since there are no electrodes or electrode-supporting members located on the light path, there is no possibility that any shade develops on the surface upon which light is projected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high pressure discharge lamp such as a short arc type xenon lamp or a metal halide lamp.

In place of the well-known xenon lamp, which has a pair of electrodes enclosed in a long and narrow quartz tube, a short arc high pressure discharge lamp, which is small and lightweight and can stably produce high output, was developed, for example, in the 1970s.
This is known as seen in Japanese Patent No. 37436.

This discharge lamp has an anode supported in a ceramic enclosure with a bowl-shaped reflective surface, an opening in the enclosure sealed with an optical window, and a plurality of metal strips adjacent to the inside of the optical window. It has a structure in which supports are provided and a cathode is supported on these metal supports.

Therefore, in this discharge lamp, the light from the arc discharge is reflected by the bowl-shaped reflective surface and emitted from the optical window, but since there are multiple supports and cathodes on the optical path inside the envelope, the light emitted from the arc discharge is There is a risk of creating shadows on the surface. Furthermore, since this discharge lamp has a built-in reflective surface, there is a problem that the reflective surface limits the direction and form of light projection to unique ones.

The present invention was proposed under the above circumstances, and its purpose is to provide illumination without creating a shadow on the surface to be illuminated, and to ensure a simple structure and versatility in usage. An object of the present invention is to provide a short arc type high-pressure discharge lamp that can be used.

That is, in the present invention, terminal rings are sealed to both ends of a cylindrical envelope formed by opening both ends, and the openings at both ends of the envelope are respectively sealed by window support members each having an optical window. At the same time, each window support member supports the anode and cathode separately along the radial direction of the enclosure with a short arc gap between them, thereby achieving the above object of the present invention. This is a short arc type high pressure discharge lamp.

The present invention will be described below with reference to an embodiment shown in FIGS. 1 to 5.

In the figure, reference numeral 1 denotes a cylindrical enclosure with both ends open, and a pair of insulating positioning walls 2 and 3 are integrally formed on the inner peripheral surface of the enclosure 1 with their positions shifted in the axial direction. It is installed protrudingly. The enclosure 1 is made of a ceramic material such as forsterite, alumina, zircon, steatite, or a composite material of these materials (alumina is used in this embodiment). Metal terminal rings 4 and 5 are provided at both ends of the enclosure 1, respectively.
is completely sealed. Each terminal ring 4, 5 is formed by cutting one end of a cylindrical sealing part A and folding it inward, and sealing the sealing part A to the outer periphery of the end of the sealing body 1 by brazing or bonding. It is attached and installed. These terminal rings 4.5
are titanium, molybdenum, and tungsten.

It is molded from a metal material such as Copal (trade name) (in this example, Copal is used) and has substantially the same coefficient of thermal expansion as the enclosure 1. Metal rear window support members 6 and 7 are sealed to each terminal ring 4 and 5, respectively. Window support members 6, 7
has a ring shape, and an optical window 8 or 9 is sealed in the central opening. That is, the openings at both ends of the enclosure 1 are hermetically sealed by the window support members 6 and 7 provided with the optical windows 8 and 9, respectively. The window support member 6°7 is connected to the terminal ring 4.
, 5 are sealed by brazing or joining to the inner sealing portion B. The optical window 8.9 is made of a transparent and highly heat-resistant material such as sapphire, lithium fluoride, or magnesium fluoride (sapphire is used in this embodiment). A gas is sealed at a predetermined pressure in the sealed body 1 having the above-described structure. The sealed gas may be an inert gas such as xenon, argon or krypton, or a selected inert gas may contain water, cesium, sodium, potassium,
A sealed gas containing metal vapor such as lithium or rubidium is used. In this example, xenon gas is sealed at a pressure of 2 atmospheres or more, and 10 in the figure indicates a sealed exhaust tube. The exhaust tube 10 is used to seal in gas, and in this embodiment, for example, the window support member 6
The figure shows the case where it is installed. This exhaust tube 10 is used as a guide for the polarity of the terminal ring 4.6, and in this embodiment, for example, the terminal ring 4 is made to be an electrode and the terminal ring 5 is made to be one pole. Furthermore, a metal electrode support shaft 11 or 12 is attached to the window support member 6.7 separately by brazing or joining. These five electrode support shafts 11, 12 are disposed within the enclosure 1 along the axial direction of the enclosure 1, and at least their tips are fitted into the insulating positioning walls 2 or 3, respectively. Positioned. The tip of the electrode support shaft 11.12 is connected to the envelope 1.
are opposed to each other along the radial direction, and an anode 13 or a cathode 14 is separately attached to each tip. This embodiment shows a case where an anode 13 is attached to an electrode support shaft 11 and a cathode 14 is attached to an electrode support shaft 12. The anode 13 and the cathode 14 are made of tungsten and thorium tungsten.

It is molded from heat-resistant metal such as molybdenum, and
The two poles 13 and 14 are arranged along the radial direction of the enclosure 1 and face each other with a short arc gap g of, for example, 2 cm or less between their tips. Such polarities13.14
In this embodiment, due to the arrangement, the high brightness point formed near the tip of the cathode 14 coincides with a point on the central axis at exactly 1/2 of the axial length of the envelope 1. There is.

In addition, in the above configuration, in this embodiment, the terminal ring 4,
5, the window support members 6 and 7, and the optical windows 8 and 9 have the same shape and structure.

In this embodiment, by supplying power from the terminal ring 4.5, the anode 3 is energized via the terminal ring 4 → window support member 6 → electrode support shaft 11, and the terminal ring 5 → window support Since the cathode 14 is energized via the member 7 and the electrode support shaft 12, a short arc is generated between the two electrodes 13 and 14. Therefore, the light obtained by this arc discharge passes through the left and right optical windows 8 and 9 and is projected in opposite directions. If the short arc type high pressure discharge lamp according to the present invention is used with such light projection performance, for example, the 6th
The usage pattern shown in FIG. 7 or 8 is possible. In addition, in the lamp according to the present invention shown in FIGS. 6 to 8, C is a lens system, and D is a spherical reflecting mirror. The focal point of the body reflecting mirror is aligned with the focal point of the mirror. 6th
The figure shows an example of use in which light emitted from both sides of a rung L is condensed by a lens system C, and the light-receiving end of an optical fiber bundle E of an endoscope, for example, is arranged in the condensing portion. Note that when used as this endoscope light source device, the incident angle θ of the optical fiber bundle E is set to 40° in accordance with the angular characteristics of the light transmission rate of the optical fiber.
Set within °. FIG. 7 shows an example of use in which the light emitted from both sides of the rung L is projected by the lens system C as a parallel light beam.

Furthermore, FIG. 8 shows an example of use in which the light emitted from both sides of the rung L is made into parallel light beams by separate lens systems C and C, respectively, and projected in opposite directions. Even in these usage examples, since no electrode or electrode supporting member is located on the optical path within the lamp L, there is no risk of shadows being generated on the light projected surface unlike in the conventional case.

Further, in this embodiment, since the insulating positioning walls 2 and 3 are provided, the positioning of the anode 13 and the cathode 14 is easy and reliable, and the assembly is convenient.

Further, one insulating positioning wall 2 is interposed between the window support member 7 and the tip of the electrode support shaft 1, and the other insulating positioning wall 3 is interposed between the window support member 6 and the tip of the electrode support shaft 12. is mediated by.

Therefore, even though a high voltage is applied to the electrodes 13.14 at the start of discharge, it is possible to reliably prevent a short-circuit accident between the conductors that are brought close to each other by the insulating positioning wall 2.3.

Furthermore, in this embodiment, since the window support parts 6 and 7 are attached to the enclosure 1 via the terminal rings 4 and 5, respectively, the load caused by the difference in thermal expansion and the increase in internal pressure when the lamp is lit can be reduced.
This can be absorbed by elastic deformation of the portions of the terminal rings 4 and 5 outside the end surface of the seal 1. Moreover, the poles 1'3 and J4 are supported by the window support members 6 and 7 via the electrode support shafts 11 and 12, and do not penetrate the barb 1, but are inserted into the enclosure 1.
No sealing is required between the Therefore, due to these factors, it is possible to more reliably prevent the occurrence of slow leakage of the sealed gas.

Moreover, according to the above structure, there is no need for a reflective surface and many electrode supports.

9- Furthermore, both 4 and 7,? , there is no need for sealing between J4 and the envelope, and instead the required sealing location is a metal-to-metal sealing location, so the metallization process required for the envelope 1 can be done without sealing. Only the outer periphery of both ends of the body 1 is required. Therefore, the overall structure is simple and can be manufactured at low cost.

Note that in the above embodiment, the electrode 13 is connected to the window support member 7.
Alternatively, the electrode 14 may be attached to the window support member 6 via the electric support shaft 11. Furthermore, the exhaust tube 10 may be attached to the window support member 7.

In addition, the specific structures, shapes, dimensions, positions, and materials of the enclosure, terminal ring, window support member, optical window 2 anode, cathode, etc., may be described in the implementation of the present invention, unless it contradicts the gist of the invention. Of course, the present invention is not limited to the one embodiment described above, and can be implemented in various ways.

As explained above, the gist of the present invention is as set forth in the claims above. Therefore, according to the present invention, the light generated inside the enclosure can be projected in mutually opposite directions through the optical window of the window support part 10- material that seals the openings at both ends of the enclosure. Various usage patterns can be obtained by obtaining any combination with a lens system, a reflecting mirror, etc. placed on the outside. Further, since there is no object outside the optical window on the optical path inside the lamp, there is no possibility of a shadow being generated on the surface to be illuminated. Furthermore, the number of electrode supports can be reduced by not incorporating a reflective surface and supporting both poles on the window support member, and there is no need for sealing between the enclosure and the electrodes, resulting in a simple and inexpensive structure. It has various effects such as being able to

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the present invention, with Figure 1 being a front view in a vertical lighting position, Figure 2 being a side view as seen from the arrow in Figure 1, and Figure 3 being the same as Figure 1 Figure 4 is a cross-sectional view taken along line IV--■ in Figure 1, Figure 5 is a cross-sectional view taken along line v-v in Figure 3, and Figures 6 to 8 are different from each other. It is a figure showing an example of use. 1... Enclosure, 4, 5... Terminal ring, 6.7...
Window support member, 8, 9... Optical window, 11.12... Electrode support shaft, 13... Anode, 14... Cathode.

Claims (1)

[Claims] A cylindrical ceramic body formed with both ends open. Metal terminal rings covering the outer peripheries of both ends are individually sealed to both ends of the plastic sealing body, and a pair of ring-shaped rings having an optical window in the center are respectively sealed to the terminal rings. The openings at both ends of the enclosure are hermetically sealed using a metal rear window support member, and the sealed gas is contained within the sealed enclosure.
One window support member supports the anode along the radial direction of the enclosure,
The other window support member is a short arc type high pressure discharge rung in which the other window supporting member supports a cathode facing the anode with a short arc gap provided between the anode tip and the anode along the radial direction of the enclosure.