| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure capable of restricting peeling of a reflection film from a luminous tube without substantially reducing a taking-out efficiency of light from a long arc type discharge lamp in a light irradiation device comprising a long arc type discharge lamp having a pair of electrodes within a luminous tube and filled with metal as luminescent material and a trough-like reflection mirror enclosing the discharge lamp and having a top opening and a band-like reflection film which extends in an axial direction and is formed on an outer surface at the top opening of the reflection mirror at the luminous tube of the discharge lamp.SOLUTION: This invention is constituted in such a way that an outer surface of a front opening side of a reflection mirror at a luminous tube of a long arc type discharge lamp is formed with a pair of band-like sub-reflection films extending in an axial direction and a translucent opening is formed at a position oppositely facing against the reflection film between the pair of sub reflection films.SELECTED DRAWING: Figure 1 |
