Patent ID: 7846356

Claim:
A method for producing fine convex and concave shapes on a surface of a material, which comprises: disposing a mask member having light transmitting sections and non-light transmitting sections over and spaced by a first distance from one side of a photosensitive film consisting of a photosensitive resin composition; exposing the photosensitive film to light from a light source disposed on the side of the mask member, through the light transmitting sections of the mask member; and removing exposed portions or unexposed portions of the photosensitive film by development to produce the convex and concave shapes on the photosensitive film, the shapes being determined by shapes of the exposed portions or unexposed portions; wherein, in exposing the photosensitive film to light, light exposure conditions are controlled so as to control the shapes of the exposed portions or unexposed portions; wherein the controlled light exposure conditions include a second distance, between the light source and a light shielding surface of the mask member, and size of the light source; and wherein the light exposure conditions are controlled so that, when distance between a point at which a normal of the light source passing the center of the light source crosses the light shielding surface of the mask member and the center of the light source is the second distance and is represented by L, and size of the light source is represented by D (length unit), and an angle θ, defined as θ=2 tan −1 (D/2L), is not smaller than 10° and not larger than 30°.