Flat illumination light having a fluorescent layer and a sealed pressurized vessel

摘要

A plurality of discharge electrodes (23), (24) are formed on a first substrate (22) at an interval between the adjacent electrodes set to 50 mu m or smaller. A fluorescent layer (26) is formed on a second substrate (25 opposed to the first substrate (22). A sealed vessel (28) is formed by locating the first and second substrates (22) and (25) so that the electrodes (23) and (24) and the fluorescent layer (26) should be located on their inner sides. A predetermined gas is introduced in the sealed vessel (28) so that a pressure of the introduced gas should be within the range from 0.8 to 3.0 atmospheric pressure. Ultraviolet rays are produced by plasma discharge and make the fluorescent layer (26) emit light which is employed as illumination light.