Patent ID: 8796949

Claim:
An ultraviolet light irradiation device comprising an ultraviolet light source that emits ultraviolet light and a housing that holds the ultraviolet light source, wherein the ultraviolet light source comprises: an array of a plurality of thin plasma tubes arranged in parallel with each other, each of which has a ultraviolet phosphor layer formed therein, a flexible support sheet supporting the array of a plurality of the thin plasma tubes, at least one electrode pair that is provided between the flexible support sheet and the thin plasma tubes, a drive circuit that applies a pulse voltage to the electrode pair, and a control circuit that controls a factor of the pulse voltage, an irradiation intensity adjustment means that outputs an intensity adjustment signal to vary the irradiation intensity, and an irradiation range adjustment means that outputs a range select signal to vary the irradiation range, and the control circuit varies a frequency of the pulse voltage applying the electrode pair according to the intensity adjustment signal output from the irradiation intensity adjustment means, and controls the drive circuit to select the electrode pair by block to be applied the pulse voltage according to the range select signal output from the irradiation range adjustment means.