Original reading apparatus

An original reading apparatus comprising:

• a plurality of image pick-up means disposed in the primary scanning direction of an original;
• and
• a compound-eye optical system for forming an image of the original on said image pick-up means, said compound-eye optical system including end surfaces, a plurality of plastic effective lens portions arranged in a staggered fashion along said primary scanning direction and a plastic protective portion provided around and formed integrally with said effective lens portions to protect said effective lens portions against moisture entry from side surfaces of said effective lens portions, said protective portion separating said effective lens portions from said end surfaces of said compound-eye optical system by more than a predetermined length, said compound-eye optical system being divided into a plurality of lens blocks, each of said lens blocks including a plurality of said effective lens portions, the boundary surface defined between adjacent ones of said lens blocks being defined in said protective portion and being inclined at an oblique angle with respect to a plane perpendicular to said primary scanning direction so as to make the distance between said effective lens portion and said boundary surface greater than if said boundary surface were perpendicular to said primary scanning direction.