A light irradiation apparatus for irradiating an object with light, includes a plurality of line-shaped light blockers arranged at a predetermined center-to-center interval, and configured to at least partially block light, and a plurality of line-shaped light irradiators arranged to overlap some of the plurality of light blockers so as to irradiate the object with light. The plurality of light irradiators are arranged to form a period not less than twice as large as the center-to-center interval of the plurality of light blockers.

A light irradiation apparatus for irradiating an object with light, includes a plurality of line-shaped light blockers arranged at a predetermined center-to-center interval, and configured to at least partially block light, and a plurality of line-shaped light irradiators arranged to overlap some of the plurality of light blockers so as to irradiate the object with light. The plurality of light irradiators are arranged to form a period not less than twice as large as the center-to-center interval of the plurality of light blockers.

A lamp lighting device is used to light a discharge lamp provided as a light source in a fluorescence detector. The discharge lamp has a configuration in which an anode and a cathode are arranged to be opposite to each other in a discharge container. The lamp lighting device includes a lamp driver, a lamp-voltage detector and a deterioration determiner. The lamp driver drives the discharge lamp. The lamp-voltage detector detects a lamp voltage in a monitoring period until a discharge state reaches a predetermined stable state after a discharge lamp in an unlit state is lit due to electrical breakdown. The deterioration determiner determines a deterioration state of the discharge lamp based on a detected lamp voltage.