JPS638007Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a microwave discharge light source device for lighting an electrodeless lamp using microwaves.

Conventionally, as a microwave discharge light source device, microwave energy is absorbed by an electrodeless lamp within a microwave resonant cavity, and a portion of the light output from the lamp is reflected by the wall of the cavity resonator body, which also serves as a reflective surface. It was designed so that

In such a structure, the wall surface of the cavity resonator body is usually finished as a specular reflective surface for the purpose of efficient use of light energy and control of light distribution. However, in the structure of the cavity resonator body in which the wall surface is finished with a specular reflection surface (mirror surface) in this way, as shown in FIG. Since the part of the power feed port 9 that guides the waves into the microwave cavity 4 cannot reflect the light beam 10 from the electrodeless lamp 8, a shadow 12 is formed on the irradiated surface 11, and uniform illuminance is not achieved in the photolithography field. Problems have arisen in the application of microwave discharge light source devices in demanding fields.

This invention aims to eliminate the above-mentioned drawbacks and provide a microwave discharge light source device that can obtain a uniform illuminance distribution and can be used in fields such as photolithography that require uniform illuminance.

In order to achieve the above object, this invention uses the wall surface of the bowl-shaped cavity resonator body with one side open as an optical reflecting surface, and also rotates the wall surface of the cavity resonator body at least including the power supply port. It is characterized in that the symmetrical surface is a diffuse reflection surface, and the non-reflective portion of the power feed port does not cast a shadow on the irradiated surface.

An embodiment of this invention will be described below with reference to the drawings. FIG. 2 is a longitudinal sectional view of a microwave discharge light source device showing an embodiment of this invention. In FIG. 2, the same reference numerals as in FIG. 1 represent the same or corresponding parts as in FIG. In the figure, reference numeral 5 denotes a bowl-shaped cavity resonator body having a rotationally symmetrical shape with one side open. A net 7 is provided which is fixed by means not shown. This net 7 forms a microwave cavity 4 together with the cavity resonator 5, and directs the microwave energy extracted from the power supply port 9 to an electrodeless lamp 8 fixed by means not shown. It absorbs light and transmits the emitted light.
The wall surface 6, which occupies a considerable solid angle around the electrodeless lamp 8, has a diffuse reflection surface 6A formed on a rotationally symmetrical surface including the power supply port 9, and a specular reflection surface 6B formed on other parts. In such a configuration, the main part of the required light distribution is obtained by the light ray 13 hitting the specular reflection surface 6B, thereby increasing the overall reflection efficiency, while reducing the amount of reflected light reflected from the diffuse reflection surface 6A. Since the light 14 becomes diffusely reflected light, the shadow of the non-reflective portion of the power supply port 8 is not cast on the irradiated surface 11. Therefore, it is possible to perform irradiation with less unevenness without reducing the overall reflection efficiency.

Here, as an example, on the mesh body 7 side of the wall surface 6, the rotationally symmetrical surface including the power feed port 9 is made a diffuse reflection surface, and the other part is made a specular reflection surface. However, if the position of the power feed port 9 is different, In some cases, the net body 7 side becomes a specular reflection surface, or depending on the purpose, the entire surface can be used as a diffuse reflection surface to obtain a uniform irradiated surface with little unevenness without projecting the shadow of the power supply port 9. Needless to say, it can be done.

According to this invention, since the rotation target surface including at least the power supply port on the wall surface of the cavity resonator body is made into a diffuse reflection surface, it is possible to prevent the shadow of the power supply port from forming on the irradiated surface, and to reduce unevenness. It is possible to provide a microwave discharge light source device that can be applied to fields such as photolithography that require a uniform irradiation surface.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the main parts of an example of a conventional microwave discharge light source device, FIG. 5 is the cavity resonator body;
6 is a wall surface, 6A is a diffuse reflection surface, 6B is a specular reflection surface,
7 is a mesh body, 8 is an electrodeless lamp, and 9 is a power supply port. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] The micro-resonator is composed of a bowl-shaped cavity resonator body with one side open, a power supply port opening on the wall of the body, and a mesh body disposed to cover the opening of the cavity resonator body. In a microwave discharge light source device equipped with a wave cavity and an electrodeless lamp provided in the microwave cavity, a rotationally symmetrical surface of the wall surface of the cavity resonator main body that includes at least the power supply port is used as a diffuse reflection surface. A microwave discharge light source device characterized by: