Exposure drum for a newspaper print-plate making apparatus

An exposure drum for use in a CTP type apparatus for making printing plates for newspaper printing using a process in which an image is drawn by a laser beam directly on a photosensitive printing-plate material wrapped around a cylindrical surface of the exposure drum wherein:

• a width (W) of the exposure drum is slightly greater than a vertical measurement (L.sub.1) of one page of newspaper;
• a circumference (L) of the cylindrical surface of the exposure drum is slightly greater than a vertical measurement (L.sub.2) of two pages of newspaper;
• first plate-material engaging pins (13a) and second plate-material engaging pins (13b) on the cylindrical surface of the exposure drum are spaced from each other by a circumferential distance (L.sub.5) which is equal to 1/2 the circumference (L);
• second plate-material suction apertures (14b) in the drum cylindrical surface are spaced from the first plate-material engaging pins (13a) by a circumferential distance (L.sub.7) which is slightly smaller than a horizontal measurement (L.sub.4) of two pages of newspaper;
• first plate-material suction apertures (14a) in the cylindrical surface are spaced from the first plate-material engaging pins (13a) a circumferential distance (L.sub.6) which is slightly smaller than the vertical measurement (L.sub.1) of one page of the newspaper;
• and third plate-material suction apertures (14c) in the drum cylindrical surface are spaced from the first plate-material engaging pins (13a) a circumferential distance (L.sub.8) which is slightly smaller than the vertical measurement (L.sub.2) of two pages of the newspaper.