JPS63237303A - Electrode-free discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an electrodeless discharge lamp used in a microwave discharge light source device, and particularly relates to improvement of its lifespan.

[Conventional technology]

FIG. 2 is a sectional view of a microwave discharge light source device disclosed in, for example, Japanese Unexamined Patent Publication No. 61-99264.

In the figure, (1) is a magnetron that oscillates microwaves with a frequency of 24 SOMHz, (2) is a magnetron antenna, (3) is a waveguide with this magnetron installed at the end, and (5) is a microwave resonant cavity. It is formed of a cavity wall (6) connected to the other end of the waveguide (3) and a light-transmitting member (7) made of a cylindrical metal mesh with a height of 90 m and a diameter of 80 cm. Reference numeral (8) denotes a power feeding port provided in the cavity wall (6), which supplies microwaves from the waveguide (3) into the microwave resonant cavity (5). (9) is a spherical electrodeless lamp placed in a microwave resonant cavity, which is filled with a rare gas, mercury, etc., and is made of a transparent material such as quartz glass.

(91) is a lamp support extending from the outer wall of the lamp (9), which is also made of a dielectric material such as quartz glass, and the lamp (9) is fixed to the cavity wall (6) with a lamp clamp 10). ing. (11) is a light reflection plate that reflects the light emitted from the microwave resonant cavity (5), (12) is a cooling fan that cools the magnetron (1) and lamp (9);
) is a ventilation hole that guides cooling air into the waveguide, and (13) is a box that covers the entire structure.

The operation of this device is as follows. Magnetron [1]
The microwave oscillated by the magneto antenna (2)
is excited as a propagation mode from the waveguide (3). This microwave is transmitted through the power supply port (8) to the microwave resonant cavity (5) whose cavity wall (6) is surrounded by a light-transmitting member (7).
Power is supplied to the The rare gas in the lamp (9) is discharged by this microwave, and this energy heats the lamp wall, and the enclosed mercury is evaporated and gasified, and the discharge is mainly a discharge of metal gas such as mercury. It emits light with a spectrum depending on its type.

The light-transmitting member (7) acts to reflect microwaves like metal, and the light is transmitted through the mesh openings. In other words, it acts as an opaque body to microwaves. Therefore, the light from the lamp is radiated out from the microwave resonant cavity (5) and the light reflecting plate (11
) is reflected. The light reflecting plate (11) is designed in various shapes depending on the purpose.

On the other hand, the magnetron (1) and the lamp (9) need to be cooled during operation of the device, and this cooling is done by cooling the magnetron (1) with cooling air from the cooling fan (12), and then using the cooling air to guide the magnetron (1). The ventilation hole (4) provided in the wave tube (3)
) is guided into the waveguide (3) and, after cooling the lamp (9) through the power supply port (8), is discharged to the outside of the device through the metal mesh (7). Note that some of the cooling air is guided directly into the waveguide through the ventilation opening (4) without cooling the magnetron (11).

[Problem that the invention seeks to solve]

In the conventional microwave discharge light source device as described above, in the diagrams in which the electromagnetic field mode (cylindrical TEIII mode) shown in FIGS. 3 and 4 is formed in the microwave resonant cavity, the actual NsE is The lines of force or electric field are shown, and the dashed line H is the line of force or the magnetic field. In addition, the circle shown in Fig. 4 indicates the lamp (9), and the shaded area inside is the lamp (9).
) shows the shape of the arc discharge part formed inside.

As is clear from this figure, the air discharge part inside the lamp (9) has an elliptical shape that is flattened in the direction of the electric field. Therefore, the lamp wall temperature at the parts indicated by A and B in the figure is When the lamp input is increased, the temperature of parts A and B reaches the softening point of the quartz glass, and the lamp bulges from these parts, leading to damage. On the other hand, when providing cooling air nozzles facing the A and B portions, there is a problem that the structure becomes complicated and at the same time it becomes an obstacle to light distribution.

[Means for solving problems]

This invention was made to solve the above-mentioned problems, and includes providing a protrusion on the lamp wall in a direction parallel to the microwave electric field formed within the microwave cavity resonator.

[Effect]

According to the present invention, the lamp cooling air flows along the lamp wall surface, and at the same time cools the lamp wall surface, it also cools the convex portion of the lamp wall surface. Therefore, this convex portion acts as a cooling fan, and the heat of the above-mentioned portions A and B is transferred from the above-mentioned portions A and B. It is released from the convex part, and the temperature of parts A and B decreases.

〔Example〕

FIG. 1 shows a microwave resonant cavity portion when an electrodeless discharge lamp according to an embodiment of the present invention is installed in the microwave discharge light source device shown in the conventional example, and in the figure, (1
4) and (14') are convex parts made of hollow quartz glass that protrude from the outer wall of the lamp (9), the above-mentioned parts A and B,
Its outer diameter is 6mm, inner diameter is 3IllI, and length is 10m.

The operation of the device in which the lamp of this embodiment is installed is basically the same as that of the conventional example, but in the case of this embodiment, the maximum temperature of the lamp wall is 1
While the temperature was 150°C, it was possible to lower the temperature by about 40°C.

In the above embodiment, a cylindrical convex portion is provided on the lamp wall, but the shape is not particularly limited, and the point is that the lamp wall A and B portions have a cylindrical convex portion as described above. It goes without saying that the object of the present invention can be achieved by providing a corresponding convex portion.

〔Effect of the invention〕

As explained above, by simply changing the shape of the lamp by providing a convex portion on the wall surface A18 of the electrodeless lamp, the maximum temperature of the lamp wall can be lowered, and a lamp with a long life can be obtained even in the case of high output lighting.

[Brief explanation of drawings]

Figure 1 shows a microwave discharge light source device equipped with an electrodeless discharge lamp according to the present invention, Figure 2 shows a microwave discharge light source device equipped with a conventional lamp, and Figures 3 and 4 show a microwave discharge light source device equipped with an electrodeless discharge lamp according to the present invention. The distribution of the microwave electromagnetic field formed within the cavity resonator is shown. In the figure, (3) is a waveguide, (4) is a ventilation hole, and (5)
is a microwave resonant cavity, (8) is a power supply port, (9) is a lamp, (12) is a cooling fan, and (14) and (14') are convex portions provided on the lamp wall. Note that the same reference numerals in each figure indicate the same or corresponding parts. 3rd r! ! J 184 Illustration procedure amendment (method) 3. Person making the amendment6, Subject of amendment (1) Drawings. 7. Contents of the amendment (Among the 11 drawings, Figures 1 to 4 will be inscribed on separate sheets. (No change in content) 8. List of attached documents (1) Engraved drawings... ...Song...-
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Claims (1)

[Claims] A microwave resonant cavity, comprising an electrodeless lamp disposed in a position where the direction of the microwave electric field formed within the cavity is approximately parallel to the central axis of the lamp, and perpendicular to the central axis of the lamp. In an electrodeless discharge lamp disposed in a microwave discharge light source device in which lamp cooling air is blown from a direction in which lamp cooling air is blown, the lamp is characterized in that a convex portion is protruded from a wall surface of the lamp in a direction parallel to the microwave electric field. electrodeless discharge lamp.