Abstract: An optical scanner assembly exposes an image on photosensitive media positioned on the internal surface of a drum platen. The assembly includes: a laser assembly for producing a laser beam representative of the image to be exposed on photosensitive media; a semi-circular flexible lens curved to the shape of the photosensitive media positioned on the internal surface of the drum platen, the lens having a plano-convex cylinder lens having a convex side facing the media; a laser beam scanner positioned between the laser assembly and the lens to scan the laser beam through the lens across the media in an image-wide pattern; and a baffle located between the scanner and the lens for extinguishing laser beam reflections from the convex side of the lens.