Color copying apparatus

Claim 1

A copying apparatus comprising: a housing fixedly supporting an image bearing master; a carriage on said housing displaceable at a scanning speed past said master and carrying a plurality of relatively fixed slot shutters spaced apart in the direction of displacement of said carriage; scanning means on said carriage at each of said shutters for directing therethrough a respective beam of a respective color component of the image on said master; a rotatable image drum on said housing; means for rotating said drum in a predetermined rotational sense at a peripheral velocity substantially equal to said scanning speed; a set of mirrors having an even number of mirrors aligned with each of said shutters for reflecting the respective beam along a respective path originating at said master and terminating at a respective location on said drum, the distance on said drum between said locations being equal to the distance on said master between the corresponding path origins, each path defining at its origin with the master an angle that is substantially equal to the angle it defines at its terminus with the respective location on said drum; means for displacing one of said mirrors of each of said sets synchronously with said carriage so that said paths maintain constant length between their origins on said master and their termini on said drum during displacement of said carriage; at least one lens in said paths equidistant between the origins and termini thereof; means for charging said drum immediately upstream of each of said locations and for applying an image former thereto immediately downstream of the respective location; and means for applying a copy sheet to said drum downstream of the respective location and for transferring the image defined on said drum by said formers to said sheet.