| 摘要 |
In a cooling liquid recirculation system, walls of transparent jacket tubes for cooling a mercury-vapor lamp, which jacket tubes are provided separately from the mercury-vapor in accordance with the prior art are formed in optical filters to thereby decrease the temperature of an object to be illuminated. A recirculation unit of cooling liquid for recirculation of the jacket tubes is connected through an elastic duct to a light source unit such as a mercury-vapor lamp. These components are movable for practical use. |
