Patent ID: 6950234

Claim:
A synthetic resin protective film placed on the front face of a prism lens which includes a multiplicity of prisms formed thereon in juxtaposition at a regular interval each having a generally heaping cross section, said prism lens adapted to emit from the front end thereof light that has entered said prism lens from the side face or the back face thereof, said protective film having at least on the back thereof a rough surface including micro protrusions/recesses for suppressing Moire fringes, blur, glare, and inversion, said protective film characterized in that said recesses around the respective protrusions connect with neighboring ones, thereby forming a net-shaped contiguous recess; and the tops of said protrusion lie in a substantially single plane defined by said protective film and said front face of said prism lens, each top having a small flat/convex face of a small curvature, the extent of said face not recognizable by naked eyes; and a multiplicity of the flat ends or convex faces of the protrusions are in substantial contact with a multiplicity of prism ridges at any relative position of the prism lens along any 2-dimensional orientation in said single plane.