| 摘要 |
<p>PURPOSE:To make arc approach a rotational symmetrical body with the curving of the arc corrected and substantially improve ununiform lightness and color over the height direction of the light receiving by installing a spherical mirror on the outside of a condensing cold mirror. CONSTITUTION:A light beam having a wave-length chiefly in the infrared region, which has passed through a condensing cold mirror 9 in the form of a parabolic surface, is reflected by a spherical mirror 10 installed outside of the cold mirror 9 and converged near the coldest point of a light emission tube 1 of quartz glass of a metal halide lamp 8 situated within the mirror 9. As a result, the temp. of the coldest point of the lamp rises, and ununiformity in the temp. in the upper part and lower part of the lamp 8 is improved. That is, the temp. of the lower part is raised by the light condensed by the mirror 10 to bring about more uniform temp. distribution over the whole lamp 8, compared with the previous condition according to the conventional techniques where the upper part of the lamp 8 has a high temp. while the lower part has a low, Thereby the arcs are level substantially and become linear in the rotational symmetricity, which leads to a great improvement of lightness and color ununiformity over the height direction of the light receiving surface.</p> |
