GB1144207A - Electrostatic printer - Google Patents

Abstract

1,144,207. Feeding sheets. SCM CORP. 8 June, 1966 [11 June, 1965], No. 25533/66. Heading B6B. [Also in Division G2] An electrophotographic apparatus (Division G2-G3) has means for feeding photo-conductive copy sheets individually from a supply into an exposure station where an image of the whole of an original to be reproduced is projected on to the copy sheet. The copy sheet, in moving into the exposure station, causes the energization of means which illuminate the original under the control of timing means. Feeding copy sheets.-Removable paper supply trays 24a, 24b comprise sheet metal plates (74), Fig. 22 (not shown), and paper guides (78) slidable to accommodate different widths of paper. One guide (78) may bo releasably fixed in one of two positions to provide correct lateral registration with a projected image as described with reference to Fig. 25 (not shown). Each guide (78) has an arm (100) pivotally mounted on a shaft (102), Fig. 22 (not shown); a turned over portion (104) acts as a front stop. Fingers (106) prevent double feed by rollers 28a and 28b, Fig. 6. Spring biased buttons (111), Fig. 23 (not shown), prevent bowing of a stack of copy sheets. Separately driven rollers 28a, 28b, Fig. 6, are mounted on square shafts 29a, 29b to permit lateral movements of the rollers on the shafts. Feeler arms 118 sense the depletion of the stack and actuate a switch 116A or 116B to operate a visible " Add paper " signal and stop the particular drive until the supply is replenished. Rollers 120, 122, and 124 feed copy sheets through corona charging unit 26 to perforated conveyer belts 30 passing around a vacuum platen 140. The copy sheet on the belts 30 is held to the belts by vacuum. The belts 30 have tensioning and guiding arrangements, Figs. 3, 4 and 5 (not shown). - A registering and trip lever 162, Fig. 6, is actuated by a copy sheet on the belts 30 to stop the belts during exposure of the copy sheet. A brake band (174), Fig. 3 (not shown), arrests belts (30) upon de-energization of a solenoid (194). After exposure, the belts are restarted to feed the copy sheet to developer station 32, Fig. 6, and a conveyer belt 34. Electrical control circuit.-The copy sheet tray to be used is selected by a switch (512), Fig. 29 (not shown), having buttons (512A) and (512(b)). If print lamp (514) is lit energization of switch (510) energizes solenoid 518 which rotates wipers on wafer switches (520A, 520B, 520C and 520D) from position 1 to position 2. Each successive pulse rotates the wipers one step. Switch (520A) energizes a paper feed clutch (108A), (108B) in position 2. A trip lever, 128, Fig. 6, actuates a switch (130), Fig. 29 (not shown). Switch (520D) controls the drive to conveyer 30, Fig. 6, and the conveyer brake. Switch (164), Fig. 29 (not shown), actuated by trip lever 162, Fig. 6, de-energizes the corona charging unit 26 and conveyer drive to stop the belts 30 and starts a timing motor (402), Fig. 29 (not shown), for exposure lamp 7. The lamp (7) remains lighted until motor (402) causes a relay (530) to be de-energized. To produce multiple copies a 22 position rotary stepper switch 441 is set to the required number of copies. When set to position " S " single copies are produced.