Web register mechanism

Claim 1

IN A MACHINE FOR EXPOSING A LIGHT IMAGE ONTO A MOVING PHOTOCONDUCTIVE WEB DURING PASSAGE OF SAID WEB ALONG A PATH THROUGH SAID MACHINE, MEANS FOR MAINTAINING A SECTION OF SAID WEB IN A PREDETERMINED, RELATIVELY FLAT PLANE DURING EXPOSURE, AN IMAGE-BEARING TRANSPARENCY HAVING REGISTER MARK MEANS THEREON, A HOLDER FOR MOUNTING SAID TRANSPARENCY FOR EXPOSURE TO SAID WEB, MEANS LOCATED ON THE SIDE OF SAID HOLDER REMOTE FROM SAID WEB FOR PROJECTING AN IMAGE ON TO SAID WEB, MEANS FOR DETECTING THE POSITION OF THE SIDE EDGE OF SAID WEB AND SENSING ANY LATERAL DEVIATION OF SAID SIDE EDGE FROM A NORMAL POSITION, MEANS RESPONSIVE TO THE MOVEMENT OF SAID DETECTING MEANS FOR LATERALLY SHIFTING SAID PROJECTED IMAGE IN ACCORDANCE WITH THE LATERAL DEVIATION OF SAID WEB FROM A NORMAL POSITION, MACHINE REGISTER MARK INDICIA IN THE APPROXIMATE PLANE OF SAID WEB, MEANS FOR ADJUSTABLY POSITIONING THE REGISTER MARK MEANS OF SAID TRANSPARENCY WITH RESPECT TO SAID REGISTER MARK INDICIA, AND SAID REGISTER MARK INDICIA HAVING A PREDETERMINED RELATIONSHIP WITH RESPECT TO THE DETECTING MEANS WHEN IN POSITION TO DETECT THE SIDE EDGE OF THE WEB IN ITS NORMAL PATH AND WITH RESPECT TO SAID PROJECTION MEANS.