Abstract: When copying is automatically started using an automatic original document feeder, an automatic start operation is prohibited after an original document jam is eliminated. When copying operations are interrupted due to an original document jam during the copying operation, an automatic original document feeder is opened and a jammed original document is removed, and the automatic original document feeder is closed again and the original document jam is eliminated, in the case that there still is an original document remaining in the automatic original document feeder after the original document jam is eliminated. An automatic start prohibiting flag is turned on. Conversely, when there is no original document remaining in such a manner, the automatic start prohibiting flag is turned off.

Abstract: In an adjustment mode, a black reference member is positioned opposite to a photosensor. Light reception data output from an A/D converter at this time is stored in a memory. In an image formation mode, based on a value obtained by subtracting output data stored in the memory from output data of the A/D converter in a state where the photosensor is opposite to an original, a copy lamp is driven. As a result, an image mode can be controlled based on an accurate detection result of an image density.

Abstract: An image forming apparatus includes a drum having a hollow polyhedron cylinder of which facets have windows. A liquid crystal cell is attached to each window of the drum for receiving image light from out side the drum on the one surface thereof to pick up a document image therein, and for receiving second light on the back surface thereof inside the drum to cause the image to be read out. The drum is rotated so that the liquid crystal cell provided on each window of the drum can sequentially receive first light reflected by the document on the one surface thereof out side the drum and second light irradiated by a second irradiating device on the back surface thereof inside the drum. A photoreceptor for receiving second light reflected by the back surface of the liquid crystal cell forms an electrostatic latent image corresponding to a document image, which is developed, transferred onto a copy paper and fixed.

Abstract: A document platen driving device is provided with an endless gear connected to a document platen, whereon a document is placed, which reciprocates. A sun gear is secured to a fixed station within a space surrounded by the endless rack, and a planetary gear meshing with the endless rack and with the sun gear is also provided within the space. The planetary gear is a double gear composed of a large gear and a small gear having different pitch circle diameters. It is arranged such that the document platen is moved forward by meshing the small gear with the endless rack, and moved backward by meshing the large gear with the endless rack. In this arrangement, the backward moving speed of the document platen can be set faster than the forward moving speed, thereby permitting a reduction of the entire time required for a copying process, especially for a successive copying process.

Abstract: A document platen on which a document is placed is movably installed on the main body of a copying machine. A motor for producing a driving force is provided. An input gear to which the driving force is transmitted is located in a fixed position. A planetary gear is positioned such that it engages with and moves around the input gear. An endless gear is connected to the document platen. The endless gear has internal teeth in the form of a closed loop which engages with the planetary gear. When the planetary gear, which engages with both the input gear and the endless gear, moves around the input gear once, one reciprocating movement of the document platen is caused. With this configuration, since there is no need to provide a switching mechanism including clutches and solenoids that is used in a conventional device, the number of components is reduced, and thereby decreasing the manufacturing costs.

Abstract: A pressure development method is achieved by passing a sheet bearing a latent image through a pair of press rollers under non-pressure, stopping the conveyance of the sheet when an area of the sheet corresponding to the forward end of the latent image thereof reaches the nip between the pair of press rollers, applying pressure to the press rollers nipping the sheet, and rotating the press rollers so as to feed the sheet.

Abstract: A copying machine using a slide projector, in which the slide projector is situated such that its light path does not coincide with that of the optical device so as to secure a smooth circulation of cooling air through the copying machine. The lack of coincidence of the optical paths is compensated by adjusting the position of a photosensitive sheet with respect to that of an exposure plate so as to effect the reliable formation of an image whether light is reflected from a document placed on a document table or projected through a slidefilm by a slide projector.

Abstract: A copying machine including a first light source for illuminating an original on an original table, a second light source for illuminating a slidefilm, a slide projector having a slidefilm support which supports a slidefilm movably and the second light source, a mirror which is movable to a reflecting position for reflecting the light reflected from the original onto the photosensitive member as well as to a retracted position for allowing the light from the slide projector to be directly projected onto the photosensitive member, a detector for detecting whether the mirror is in the reflecting position or in the retracted position, and a light regulator for regulating power supply to either one of the first light source or the second light source which is selectively put into operation on the basis of the detected result of the detector.