| 摘要 |
PURPOSE:To irradiate only a visible ray without generating a color shade by surrounding the vicinity of the periphery of a straight tubular lamp with a cylindrical filter having a dichroic film, on the same axis. CONSTITUTION:A straight tubular light source lamp 1 is provided with a reflecting mirror 2 of a certain shape of cross section, along the axis. A hot-wire breaking filter 3 having a dichroic film on its surface is arranged on the periphery of the light source lamp 1. The hot-wire breaking filter 3 is not less than 20mm thicker, for example, than the outer diameter of the light source lamp 1, and the length is defined such that the entire light source lamp 1 except a socket portion is covered therewith, thin films of quartz and titanium oxide being deposited alternately on the external wall surface. Through a slit 3a, the air in the hot-wire breaking filter 3 is substituted. As the filter 3 and the light source 1 are situated close to one another on the same axis, color separation hardly occurs and few color shades are generated. |
