Abstract: A copying apparatus capable of copying and printing an image of a document on one side or on either side of a printing sheet including a plurality of image recording units each including an image recording member and a variety of devices associated with the image recording member for performing image copying. The adjacent two image recording units are connected together by a printing sheet transporting path provided with printing sheet reversing means having a switch member. Printing sheets each having an image of a document copied and printed on one side thereof by the image recording member of the first image recording unit have their posture reversed by the printing sheet reversing means so that an opposite side thereof will face the image recording member of the second image recording unit, whereby the image of the document can be printed on the opposite side of the printing sheets.

Abstract: A plurality of copying machines (12), (13), (14) are connected to a computer (39). Each copying machine (12), (13), (14) comprises sensor means (16), (17), (18), (19), (21), (22), (23), (24) for sensing various operating parameters thereof such as a total number of copies produced, machine malfunctions, amounts of remaining copy sheets and toner, etc. These parameters are all transmitted to the computer (39) which processes and prints them out. In response to a copying machine malfunction the computer (39) feeds back to the malfunctioning copying machine instructions for correction. The instructions are displayed at the copying machine. The computer (39) further computes the degree of degeneration of the photoconductive element of each copying machine (12), (13), (14) and controls the imaging exposure intensity and developing bias voltage in accordance therewith.

Abstract: The vertical and horizontal lengths of an original document (28) are automatically sensed and compared with the vertical and horizontal lengths of a copy sheet (38) and the reduction ratio of a variable magnification optical system (33) is automatically adjusted in accordance therewith so that the maximum length of the image of the document (28) is equal to the corresponding vertical or horizontal length of the copy sheet (38). The image may be selectively parallel to the vertical length or the horizontal length of the copy sheet (38) regardless of whether the image is parallel to the vertical or horizontal length of the document (28). In one form (21) of the invention the document (28) is placed on a platen (27) so that the image is parallel to the vertical length of the platen (27) regardless of whether the image is parallel to the vertical or horizontal length of the document (28).

Abstract: First and second original documents are copied on the opposite sides of a copy sheet in superposition in such a manner that the centers of the two copied images on the opposite sides of the copy sheet are coincident with each other. The two copied images are offset from the center of the copy sheet, leaving a blank area at one edge of the copy sheet for binding a number of copy sheets together in book form. The present copying machine is further provided with two sheet cassettes containing copy sheets of different sizes, a device for selecting the desired copy sheet size and intermediate sheet holder for temporarily holding the selected copy sheet between the copy operations of the first and second original documents.

Abstract: The auto document feeder is for use with duplex copying machines, and is capable of inverting duplex sheet originals, having images on both surfaces, automatically and feeding the originals to an exposure station automatically. The feeder comprises trays for stacking a plurality of sheet originals to be copied, sheet feeding devices for feeding the sheet originals individually from the trays to the exposure station, a platen belt mounted on the exposure station and operable to transport a sheet original across the exposure station and to maintain each sheet original in close contact with the exposure station during exposure of the sheet original, from either side of the exposure station, sheet inverting devices for inverting sheet originals received from the exposure station, and a sheet transport device for transporting inverted sheet originals to the exposure station for completing the duplex copy.

Abstract: A duplex copying machine has an auto document feeder and is capable of duplex copying from originals having images on one side, originals having images on both sides and combinations of the aforementioned two types. In a preferred embodiment of the duplex copying machine, whether an original has images on one side only or on both sides is detected so as to obtain a duplex copy from a duplex original and a one-side copy from a one-side original.

Abstract: In successively copying a plurality of continuous pages of a book original by means of a copying apparatus adapted to print images of the pages on opposite surfaces of each copy sheet, a printing operation is controlled in such a manner that a series of processes including, illumination of the pages, charging and exposing of a photosensitive drum, developing, fixing and transfer printing of visible images, and ejection of printed copy sheets is automatically performed, if the book original is opened at desired pages and placed on an original placing glass plate of the copying apparatus in a normal condition in which the top of the book original is remote from the operator.

Abstract: First and second original documents are copied on the opposite sides of a copy sheet in superposition in such a manner that the centers of the two copied images on the opposite sides of the copy sheet are coincident with each other. The two copied images are offset from the center of the copy sheet, leaving a blank area at one edge of the copy sheet for binding a number of copy sheets together in book form. The present copying machine is further provided with two sheet cassettes containing copy sheets of different sizes, means for selecting the desired copy sheet size and intermediate sheet holder means for temporarily holding the selected copy sheet between the copy operations of the first and second original documents.

Abstract: In the method, two originals are placed side-by-side on the contact glass of an electrophotographic duplex copying machine and are scanned successively, in a single scanning operation, by the exposure optical system of the machine to form respective successive images on a photoconductive drum rotated past an image transfer device. Two transfer sheets are fed successively, with a short interval therebetween, from a primary supply device for transfer sheets, past the image transfer device in synchronism with the image formation on the drum, to provide duplex copies, having images in the same relation as that of the two originals, in a single copying cycle or process. By utilizing a secondary sheet supply device and a suitable switching device, images can be provided on both sides or surfaces of a transfer sheet or sheets. The duplex copying apparatus includes a novel sheet feed device effective to stack transfer sheets neatly.

Abstract: A plurality of electrostatic copying machines (12), (13), (14), (16) are interconnected by bus lines (19), (21), (22). Each copying machine (12), (13), (14), (16) is provided with a sensor unit (23) for sensing various status parameters of the copying machine (12), (13), (14), (16) such as whether the copying machine (12), (13), (14), (16) is available for use, the copy sheet size, the number of copies made, the number of copy sheets remaining, etc. Each copying machine (12), (13), (14), (16) is further provided with a display unit (17) for displaying the status parameters of all of the copying machines (12), (13), (14), (16). A microcomputer (31) is provided at one of the copying machines (12) for storing and processing the status parameters and producing a hard copy.