JPH03250552A - Ceramic lamp - Google Patents

Abstract

PURPOSE:To have sufficient heat emission from a lamp by forming a multi-layer film, which admits penetration of infrared beam and reflects visible beams, over the concave surface of a concave mirror through which infrared beam penetrates. CONSTITUTION:A lamp concerned is provided with a concave mirror 7 which has a penetration zone at least in the infrared region and whose inside consists of light penetrative ceramics formed concavely, and a multi-layer film 8 reflecting visible beams and admits penetration of infrared beam is formed over the inner surface of the mirror 7. Another multi-layer film 11 admitting visible beams and reflecting the other is applied to the inner surface of a window member 10. Light is generated by the use of electric discharge due to an anode 1 and cathode 2, and visible beams directed to the film 8 are reflected while the infrared and ultra-violet beams are allowed to penetrate and go out of the lamp. The visible beams reflected by the film 8 and the ones directed directly to the film 11 from the bright point are permitted to penetrate the film 11 and window member 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a lamp that obtains parallel light, and more particularly to a ceramic lamp whose casing is made heat resistant.

[Prior art] Endoscopes such as gastrocameras include fibers that irradiate illumination light onto a subject (such as the stomach wall) and pass reflected light from the subject, lenses that are attached to the tips of these fibers, and lenses that are attached to the rear end of the fibers. It consists of a light source device and an imaging device. In this endoscope, it is necessary to uniformly irradiate the irradiation surface with light and to avoid irradiating infrared light or ultraviolet light that is unnecessary for observation. For this purpose, a small discharge lamp or light source that utilizes discharge from a pair of electrodes is used as a light source.

For example, U.S. Pat. No. 4,599,540 relates to this type of lamp.

[Invention or Problem Solving Section B] However, in the above-mentioned conventional technology, when trying to extract only visible light from the front of the lamp, the heat generated along with the light is trapped in the casing (infrared light or infrared light inside the casing). (may be absorbed by the lamp and turned into heat), which may cause the lamp to heat up. Therefore, special considerations such as providing large fins for heat dissipation are required, and the installation space becomes large.

The present invention has been made in view of the above-mentioned state of the prior art, and an object of the present invention is to provide a ceramic lamp that is miniaturized and has sufficient heat dissipation.

[Means for Solving the Problems] In order to achieve the above object, the present invention comprises a first translucent ceramic having a concave interior and having a transmission band at least in the infrared wavelength range. a concave mirror having a first dielectric multilayer film that reflects light in the visible region on its concave surface; a first metal member that airtightly covers the rear end opening of the concave mirror; and a first metal member that is supported by the metal member and passes through the opening. a first electrode extending into a space surrounded by the concave surface, and a second dielectric multilayer that transmits light in the visible region on the inner surface of a second plate-shaped transparent ceramic having a transmission band in at least the visible region. a window member provided with a membrane; a second metal member airtightly connecting the window member to the front end opening of the concave mirror; and a cavity supported by the second metal member and passed through the opening and surrounded by the concave surface. The device includes a second electrode extending from the concave mirror, and a component that emits light by discharge, which is enclosed within the concave mirror.

In addition, xenon, which easily emits visible light with a natural tone, is used as the filler gas.

[Function] According to the above means, the concave mirror reflects visible light and transmits infrared and ultraviolet light, so the concave mirror, which forms the main part of the housing, radiates heat to the outside without trapping heat. , less heating of the casing.

And because the concave mirror transmits infrared light to the outside.

Even if xenon, which easily generates infrared light, is used as the filler gas,
There is no buildup of heat caused by infrared light.

[Example] FIG. 1 is a sectional view showing one embodiment of the present invention.

A rod-shaped cathode 2, which is a second electrode, is disposed coaxially with a rod-shaped anode l, which is the first electrode.The tip of the anode l is curved, the tip of the cathode 2 is made at an acute angle, and kept at regular intervals. The anode l is held by a first metal member 3, and the cathode 2 is held by a second metal member 4.

The first metal member 3 includes a holding plate 3 holding an anode l in the center.
a and a cylindrical retaining ring 3b that is fitted onto the ring.

Further, a spacer 5 is arranged on the inner periphery of the retaining ring 3b adjacent to the retaining plate 3a.

Note that the retaining plate 3a and the retaining ring 3b can also be formed by integral processing instead of being made as separate bodies. Furthermore, a metal exhaust pipe remainder 6 is provided on the holding plate 3a.

The neck of a first concave mirror 7 made of translucent salamic material and having a cross-sectional or parabolic reflecting mirror formed on its inner surface is coupled to the tip of the retaining ring 3b.

An anode 1 passes through the center, and this penetrating portion is hollow, and the tip of the electrode is exposed within the mirror surface. A dielectric multilayer film 8 is formed on the inner surface of the concave mirror 7 using a material that reflects visible light (wavelength: 0.41 to 0°8 gm) and transmits infrared light (wavelength: 0.8 gm to 6 μm). ing.

On the other hand, the second metal member 4 has a cylindrical shape, and has a holding ring 4a fixed to the rear end or the edge of the concave mirror 7, and a plate-like metal member, which is vertically disposed and fixed within the holding ring 4a. and a holding plate 4b for holding the cathode 2.

A cushion ring 9 having a cross-sectional shape or a U-shape is fitted into the inner periphery of the tip of the retaining ring 4a. A window member 1O is fitted into this cushion ring 9. Furthermore, window member I
A dielectric multilayer film 11 that transmits visible light and reflects non-visible light is applied to the inner surface of O.

In the lamp made as described above, the concave mirror 7
A sealed space (i.e., a discharge space) is formed inside the exhaust pipe, and in this space, an inert gas (such as xenon gas is filled at a pressure of 17 atmospheres, for example) is filled with the remaining part of the exhaust pipe for the purpose of improving discharge characteristics such as stabilizing brightness. 6.

The materials used for each member in the above configuration are, for example, as follows. Basically, the thermal expansion coefficients of adjacent members are selected to be the same or similar to each other to avoid mechanical deformation.

Anode 1: Tungsten (expansion coefficient C8
10-"C-') Retaining ring 4a: Alloy of iron, nickel, and copper (for example, trade name Kovar, expansion coefficient 4.4-5.2 Xl0-6°C-I) Retaining plate 4b = Molybdenum spacer 5: Copper Remaining part of exhaust pipe 6: Nickel concave mirror 7: Ceramic (translucent alumina molded to a thickness of 3.1 mm) Multilayer film 8: T+02+5i02 Cushion ring 9/Kovar window member lO: Sapphire (thickness: 31 mm, expansion coefficient: 5.1 mm) 7
xto-'℃-1) Multilayer film 11: TiO□+5i02+Al2O:s Also, a ceramic seal 12 is placed at the joint between the retaining ring 3b and the concave mirror 7, a ceramic seal 13 is placed between the concave mirror 7 and the retaining ring 4a, and a ceramic seal 13 is installed between the concave mirror 7 and the retaining ring 4a. A ceramic seal 14 and a ceramic seal 15 are provided on the outer periphery and the inner periphery, respectively. This is a concave mirror 7 and a window member lO, which is a metal layer formed by metallization using the Mo-Mn (molybdenum-manganese) method and nickel plated on top of the metal layer.
This metal layer is coated with a metal brazing material (e.g.
C, , C, /A, , A, etc.) to achieve sealing.

FIG. 2 shows the reflectance characteristics of the mirror surface by the multilayer film 8, and it can be seen that only visible light can be effectively reflected. The layer structure in this case uses a plurality of alternating layers of TiO2 with a high refractive index and 5iOz with a low refractive index.

Further, FIG. 3 shows the light transmission characteristics of the multilayer film 11.

The multilayer structure in this case consists of the following layer configurations. As is clear from Figure 3, it transmits visible light,
Reflects infrared light.

First layer: 5in2 (window member IO side) Second layer: Al2O□ Third layer: TiO□ Fourth layer: 5if2 Next, the operation of the embodiment with the above configuration will be described.

When a DC power source (for example, DC 20V) is applied to the anode 1 and the cathode 2, a discharge occurs between the electrodes, and some of the light from the bright spot goes directly to the window member 10, while the rest goes to the multilayer! ! Head to 8. The visible light directed toward the multilayer film 8 is reflected by the front surface of the mirror, and the infrared and ultraviolet light passes through the multilayer film 8 and the concave mirror 7 and exits out of the lamp.

On the other hand, the light that goes directly to the multilayer film 11 from the bright spot either contains light other than visible light, or because the multilayer film 11 has the characteristics shown in FIG. 3, only visible light is transmitted. Others are reflective. In addition, since the light reflected by the multilayer film 8 contains almost no infrared light or ultraviolet light, the light reflected by the multilayer film 8 is directly reflected by the multilayer film 8.
1, then pass the window member 10 and go straight.

Next, the heat dissipation effect obtained from the structure of the present invention will be explained.

For example, if the power consumption of a lamp is so low, approximately 275 W is lost due to light and 225 W is lost due to heat conduction and convection. Furthermore, the breakdown of 275W is 60W of visible light from the arc, 215W of infrared light and ultraviolet light from the arc, and radiation from the electrodes.

If only the visible light that is desired to be used is prevented from exiting the lamp, in addition to the 135 W of infrared and ultraviolet light, the loss of 80 W due to radiation from the electrodes becomes a heat source for the lamp housing. If any of this remains inside the lamp, it will become extremely hot and dangerous. So, 135W+ 80w-21
It is necessary to release 5W to the outside of the lamp by some method. In the cathode 2, 75% of the heat is transferred via the first metal member 4 to heat radiation fins (not shown), and the heat is radiated to the atmosphere from the heat radiation fins. Heat is also dissipated from the anode l by similar means.

However, according to the present invention, as described above, the multilayer IJ
Concave mirror 7 has the property of transmitting infrared light and ultraviolet light.
are made of a translucent material and similarly transmit infrared and ultraviolet light, so no heat is retained within these members and no heating occurs. Furthermore, since the multilayer film 11 prevents the irradiated surface (such as the stomach wall) from being irradiated with infrared light, the irradiated surface will not be heated.

In addition, in the above embodiment, multi-Jii FM8 and multi-layer 1
1111 was made from Tie and 5in2, but
ZrO2 or Ta205 may be used instead of Tie2.

[Effects of the Invention] Since the present invention is configured as described above, it produces the following effects.

In the ceramic lamp according to claim (1), the inner or concave first portion has a transmission band in at least an infrared wavelength region.
a concave mirror made of translucent ceramic, having a first dielectric multilayer film applied to the concave surface of the translucent ceramic to reflect light in the visible range, and a first metal hermetically sealing the rear end opening of the concave mirror. a first electrode supported by the metal member and extending through the opening into a cavity surrounded by the concave surface;
A window member is provided with a second dielectric multilayer film that transmits the visible region on the inner surface of a plate-like second translucent ceramic having a transmission band in at least the visible region, and the window member is provided in the front end opening of the concave mirror. a second metal member connected in an airtight manner;
The second electrode is supported by a metal member and extends through the opening into the space surrounded by the concave surface, and a component that emits light by discharge sealed in the concave mirror.
Since the lamp is made smaller, unnecessary light is not applied to the irradiated object, and heat is not trapped in the casing.

In the ceramic lamp of claim (2), since xenon gas is sealed within the concave mirror surface, discharge performance can be improved and stable light can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a reflectance characteristic diagram showing the reflection characteristics of the multilayer film 8, and FIG. 3 is a reflectance characteristic diagram showing the reflection characteristics of the multilayer film 11. . In the figure. 1: Anode 2: Cathode 3: First metal member 4: Second metal member 3a, 4b: Holding plate, 3b, 4a: Holding ring 7: Concave mirror 8.11: Multilayer film 9: Cussimin ring 10, window Element

Claims (2)

[Claims] (1) It is made of a first translucent ceramic having a concave interior and having a transmission band in at least the infrared wavelength range, and a first dielectric multilayer film that reflects light in the visible region is provided on the concave surface of the translucent ceramic. a first metal member that airtightly covers a rear end opening of the concave mirror; a first electrode that is supported by the metal member and extends through the opening into a space surrounded by the concave surface; a window member in which a second dielectric multilayer film that transmits the visible region is applied to the inner surface of a plate-shaped second translucent ceramic having a transmission band in the visible region; and the window member is placed in the front end opening of the concave mirror. a second metal member airtightly connected; a second electrode supported by the second metal member and extending through the opening into a space surrounded by the concave surface; What is claimed is: 1. A ceramic lamp characterized in that the concave mirror has a cavity within the concave mirror as a discharge cavity. (2) Claim (1) characterized in that the discharge space contains xenon as a component that emits light due to discharge.
The ceramic lamp described in .