Patent GB-1094188-A (GB)
Title: Document re-producing apparatus
IPC: G03G15/00
Filed: 1964-12-22
Abstract: 1,094,188. Electro-photographic apparatus. RANK XEROX Ltd. Dec. 22, 1964 [Jan. 2, 1964], No. 51998/64. Heading G2H. [Also in Division F2] A xerographic copier contains an optical assembly, mounted for vertical movement on a column, for forming an image of a document on a photo-conductive surface. A rotating drum (252) Fig.7 (not shown) is electro-statically charged, imagewise exposed using the optical assembly described below, developed by cascading powder over the drum, the toner used being replenished from a dispenser (296), brought into contact with a copy sheet to which the developed image is transferred under the influence of an electrostatic field, and cleaned by recharging, brushing and uniform illumination, the toner removed being extracted from the air-cooled copier by a fan (336). The copy sheet on to which the developed image is transferred, is manually fed into the copier at station (306) where a gripper (304) on a conveyer chain (302) transports it into contact with the drum (252) for the transfer, past heat-fixing elements (R1)-(R3), to a discharge shoot (322). In the optical assembly, light from the illuminated document is reflected, via mirrors 98 and 102 and a lens assembly 104 on to xerographic drum (252). Different magnifications or reductions of the image formed on the drum may be produced by varying the height of the optical assembly above the drum and the position of the lens between the mirrors 98 and 102. The optical assembly is mounted in a frame 106 which in turn is mounted for vertical movement on a column 112, which movement is effected by a drive motor MOT-7 via a pulley system Figs. 2, 8 and 11 (not shown) and a pair of magnetic clutches (SC-3), (SC-4), Figs. 14 - 16 (not shown); the frame may be selectively arrested by switches (21LS)-(26LS) in any of four positions depending on the reduction in image size required. The lens assembly is mounted on a shaft 148 and is automatically moved horizontally by a motor MOT-1 via a magnetic clutch SC-2 Figs. 5 and 6 (not shown), when frame 106 is moved vertically, and is arrested by one of switches 15LS-20LS depending on the position of frame 106; shaft 148 is mounted at an angle of 26' to the vertical plane joining the centres of mirrors 98 and 102 to maintain the position of the image of the document on the copy sheet approximately constant. The system for conveying the document to be carried through the apparatus is described in Specification 1, 094, 189 and consists of a parallel series of conveyer belts Figs. 2, 3 and 11 (not shown), above which are mounted a series of, rollers consisting of polyurethane discs (30) mounted on floating (32) and fixed shafts (33) in a staggered arrangement, the inserted document is held on the conveyer belts (18) by the rollers (30) and transported on to a platen (34) at an exposure station 20, and then discharged through either the front or back of the copier depending on the position of a deflector 75; fingers 56 and 62 and mis-feed switches 5LS and 6LS are provided to ensure the documents are conveyed correctly. Electrical control means Figs. 17 and 18 (not shown) are provided for automatically synchronizing the speed of the xerographic drum, copy sheet and document, for controlling the warming up and shutting down of the copier, for effecting the movement of the optical and lens assemblies and preventing the copier malfunctioning. Reference has been directed by the Comptroller to Specifications 997, 417 and 950, 313.