Filter for a low-pressure mercury vapor lamp.

摘要

A filter for absorbing radiation of a selected wave length emitted from low-pressure mercury lamp means is disclosed. The filter comprises means for providing an ozone-containing gas layer positioned between the low-pressure mercury lamp menas and an object to be illuminated, which may be formed by providing a transparent space filled with the ozone-containing gas between the lamp means and the object. By this means, a relatively large sized filter which has a simple construction may be obtained.