G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
G03B27/00—Photographic printing apparatus
G03B27/02—Exposure apparatus for contact printing
G03B27/14—Details
G03B27/18—Maintaining or producing contact pressure between original and light-sensitive material
G03B27/22—Maintaining or producing contact pressure between original and light-sensitive material by stretching over a curved surface