Light irradiation device

In a light radiation device having filter films for holding a plurality of filter film plates by a frame and cross pieces thereof, the light radiation device prevents the uniformity of illumination distribution of light radiation surface from being decreased. The light reflected by a light source (H) is reflected at a first reflection mirror (3), and incident to an integral lens (4) configured with a plurality of rectangle lenses through the filter film (10). The filter film (10) is formed by the frame (holding frame) and a plurality of filter film plates formed at the cross pieces of the frame vertically and horizontally to keep rectangle. Therefore, the cross pieces shade the light from the light source (H) to form a linear shadow on the integral (4) so that the illumination distribution in the radiated surface is not uniform. Therefore, the filter film (10) is inclined, wherein the cross pieces of the filter film (10) are opposite to the side of each lens of the integral lens (4), and the filter film is no