| 摘要 |
The invention is to provide a lamp that efficiently emits ultraviolet rays within a wavelength range of 300 to 380 nm necessary for polymerizing monomers, in order to provide the optimum light source for PSA (Polymer Sustained Alignment). The invention is a lamp which comprises a discharge vessel having discharge gas including krypton gas and iodine gas sealed in the same, and a pair of electrodes arranged face to face and formed inside the discharge space of the discharge vessel in the way of pinch, for emitting ultraviolet rays of the wavelength 342 nm by forming excited iodine molecules. The features are the concentration of the iodine gas contained in the discharge gas is 0.04% to 0.9% and when the electric field intensity applied on the discharge space is E (kV/cm), a partial pressure of the above-mentioned rare gas is p1 (kPa), and a partial pressure of the iodine gas is p2 (kPa), the equation E/p1≥(6.6×p2+124)×exp(-0.0093×p1) is established. |
