Scanning light exposure apparatus

A scanning light exposure apparatus comprising:

• a plurality of illumination optical systems for irradiating light beams to a corresponding plurality of sub-areas in a pattern area of a mask;
• a plurality of projection optical systems arranged along a predetermined direction for projecting erected images of unity magnification of the sub-areas by respective light beams transmitted through the mask onto a photo-sensitive substrate;
• each illumination optical system having a diaphragm member arranged at a substantially conjugate position to the photo-sensitive substrate in said illumination optical system for limiting a projection area of the sub-area to the photo-sensitive substrate;
• scanning means for synchronously scanning said mask and said photo-sensitive substrate substantially transversely to the predetermined direction relative to said projection optical system;
• and
• diaphragm control means for changing a width of an aperture of each diaphragm member along a direction transverse to the predetermined direction.