Optical light spot scanning device for a photosensitive web material in optical photocomposing machines

摘要

Photocomposition apparatus comprises a modulated laser for generating a modulated laser beam; a holder for the photosensitive material, with the holder having the shape of a segment of a cylinder whereby the photosensitive material in the holder adopts a partially cylindrical shape; an optical image forming system and a rotatable mirror arrangement mounted on a carriage, by means of which the rotatable mirror arrangement can be displaced with its axis of rotation coaxial to the cylinder axis of the holder along this cylinder axis. The laser beam which falls on the rotatable mirror arrangement via the optical image forming system, and which is substantially radially directed towards the photosensitive material in the holder after reflection at the rotatable mirror scans the photosensitive material linewise as a result of rotation of the rotatable mirror and displacement of the carriage along the cylinder axis of the holder, and thereby generates a desired latent pattern in the photosensitive material. The laser is arranged on the carriage and the carriage, the laser, the optical image forming system, the rotatable mirror arrangement and also any other light deflecting parts which are present are preferably arranged essentially in a plane which extends parallel to a plane containing the two ends of the holder.