Abstract: A sheet transport device is provided with a sheet inverting mechanism for retracting a sheet transported along a main transport route into a switchback route to invert the sheet transport direction and returning the sheet into the main transport route to turn the side of the sheet. The sheet transport device has a pair of sheet guides adapted in contact with respective opposite ends of the sheet set on a sheet setting portion to prevent a skew transport of the sheet. The sheet temporarily brought onto the sheet setting portion during a switchback operation from the switchback route is guided between of the sheet guides on the sheet setting portion. During the temporal appearance on the sheet setting portion, the opposite ends of the sheet are aligned by the respective sheet guides. Thereby, securely prevented is an occurrence of a skew transport state of the sheet during the switchback operation.

Abstract: In a paper transport device, a first roller serving as a separation roller is situated underneath a second roller serving as a document feed roller, together forming a roller pair. A rotary shaft of the separation roller is biased upward toward the document feed roller by means of an elastic element. One end of the rotary shaft is connected to a drive shaft via a coupler while a connecting bar is joined to the other end of the rotary shaft obliquely from above. An extreme end of the connecting bar opposite to the rotary shaft is attached to a support plate fixed to a main body of the paper transport device in such a way that the connecting bar can swing about pivot pin fixed to the support plate. In the paper transport device thus constructed, one end of the rotary shaft fitted to the coupler acts as a point of support, allowing the other end of the rotary shaft to move downward overwhelming an upward-lifting force of the elastic element when forced downward by the connecting bar.

Abstract: A sheet transport device is provided with a sheet inverting mechanism for performing a switchback operation in which a sheet transported along a main transport route enters a switchback route, and the sheet transport direction is inverted in the switchback route to return the sheet to the main transport route so as to turn the side of the sheet. A registration roller pair is disposed near the junction between the main transport route and the switchback route. The sheet inverting mechanism is operated in such a manner that the sheet transport is temporarily suspended until a skew correctable portion that enables correction of a skew transport state of the sheet is formed at a lead end of the sheet in the exiting direction from the switchback route after the lead end of the sheet comes into contact with the registration roller pair. Thus, the skew transport state of the sheet which is liable to occur during the switchback operation is corrected.

Abstract: An automatic document conveyer comprising a moving frame turnably mounted on a machine housing via a hinge mechanism and a conveyer belt mechanism mounted on the moving frame. The conveyer belt mechanism includes a support frame, a drive roller and a driven roller arranged in the support frame, and a conveyer belt wrapped round the drive roller and the driven roller. The support frame of the conveyer belt mechanism is so supported as to be moved by a predetermined amount toward the side opposite to the hinge mechanism while the end of the conveyer belt on the side of the hinge mechanism reaches to the closed position after having come in contact with the transparent plate at the time when the moving frame is turned toward the closed position.

Abstract: A document fed from a document tray to a first transport path is guided to a document inverting unit to invert a transport direction of the document. Subsequently, the document is transported to an image reader unit along a second transport path for image data reading on the opposite side of the document opposite to a side facing upward when set on the document tray. Then, the document is guided to the document inverting unit again via a fourth transport path intersecting a third transport path at a first intersecting point to invert the transport direction of the document again. Thereafter, the document is transported to the image reading unit again via the second transport path for image data reading on the one side of the document. The document is discharged onto a discharge tray via the third transport path with the one side facing downward.

Abstract: A recycle document feeder includes a partitioning unit (17) and action plates (19, 20). The partitioning unit (17) includes a partitioning bar (18). When the partitioning bar (18) is lowered, the leading edges of discharged document originals are stopped by the partitioning bar (18). The action plates (19, 20) guide the discharged document originals toward an upper side of the trailing edges of document originals yet to be fed, and push the trailing edges of the discharged document originals to transport the document originals for re-feeding thereof. The partitioning unit (17) and the action plates (19, 20) are driven by a common motor (47). Further, a partitioning unit driving mechanism (110) and an action plate driving mechanism (111) are provided for driving the partitioning unit (17) and the action plates (19, 20), respectively.

Abstract: An automatic document feeder 1 automatically operates a tray depending on the operating conditions of the automatic document feeder. The automatic document feeder 1 has a set surface 7 on which originals to be conveyed are to be set. An original receiving tray 11 for receiving discharged originals is provided in the vicinity of an original discharge port 10. A lower end of the original receiving tray 11 is rotatable, and a tray driving device is connected to the back of the original receiving tray 11. The tray driving device rotates and displaces the original receiving tray 11 around the lower end depending on the operating conditions of the automatic document feeder 1. The original receiving tray 11 is raised almost perpendicularly until the originals are set on the set surface 7 (see FIGS. 4A and 4D). When the originals are conveyed, the original receiving tray 11 is rotated to an obliquely laid state (see FIGS. 4B and 4C) in order to receive the paper sheets discharged from the discharge port 10.

Abstract: An image forming apparatus transfers a toner image formed on a photoconductive member onto transfer paper by passing the photoconductive member consecutively beside a main charger, exposure unit, developer unit, pre-transfer charger, transfer charger, and charge remover. During image formation under conditions with temperature or humidity lower than a predetermined level, the pre-transfer charger is deactivated.

Abstract: A sheet feeding unit includes a sheet forwarding unit for forwarding sheets from a sheet storing unit, a key input portion, a sheet detection gate, and a control unit. In one embodiment, the sheet forwarding unit repetitively performs its function after an operation start instruction until either the sheet detection gate detects a sheet from the feeding cassette or until the number of repetitions of the sheet forwarding unit reaches a predetermined number. An error process is performed when the number of repetition reaches the predetermined number without the gate detecting a sheet. Also, the sheet feeding unit compares the number of times a sheet is fed from the sheet feeding unit with the number of times the sheet if forwarding to determine the status of the feeding roller.

Abstract: An encoder is connected to the drive system of the optical system of an image forming apparatus including an optical system for exposing a document image to a light and scanning the document image, a home position switch for detecting the optical system when it comes to the vicinity of the starting position, and a resist roller for setting the feeding start timing of a transfer sheet to the transfer section, and, on reproducing the above document image on a transfer sheet, when the pulse signals coming from the encoder, which are counted from the time when the optical system passes through the home position switch, reach the appointed value, the above resist roller operates.

Abstract: It is a major object of the present invention to break down and level a heap-up of toner built in the hopper through dropping from the cartridge when feeding toner into the hopper and to prevent toner from leakage from the cartridge due to erroneous operation with a remarkably simple and cheap construction. Namely, the leveling member moves a plurality of number of times in line with engaging and disengaging operation of the cartridge for the hopper and opening and closing operation of the cartridge in the same direction of the shutter, thereby causing a heap-up of toner built in the hopper housing of the hopper to be effectively broken down and leveled. Furthermore, only when the shutter is in its closed status for the cartridge, the cartridge can be removed from the opening of the hopper.

Abstract: The present invention relates to a system for making discriminations between cartridges for housing toners to be equipped on image forming apparatus such as electrostatic copiers, laser beam printers, facsimiles, etc. in which while a cartridge indicating means is provided on a part of a toner housing cartridge, an indication detecting means for detecting the aforementioned cartridge indicating means is provided on the image forming apparatus proper side, so that the suitability of the type or position of the cartridge inserted is detected by detecting the cartridge indicating means by the aforementioned detecting means, when the cartridge has been inserted into the cartridge inserting part of the image forming apparatus proper.

Abstract: The present invention relates to a system for making discriminations between cartridges for housing toners to be equipped on image forming apparatus such as electrostatic copiers, laser beam printers, facsimiles, etc. in which while a cartridge indicating means is provided on a part of a toner housing cartridge, an indication detecting means for detecting the aforementioned cartridge indicating means is provided on the image forming apparatus proper side, so that the suitability of the type or position of the cartridge inserted is detected by detecting the cartridge indicating means by the aforementioned detecting means, when the cartridge has been inserted into the cartridge inserting part of the image forming apparatus proper.

Abstract: An image forming apparatus having a potential sensor for measuring a potential at the surface of a photoreceptor drum; a voltage generation circuit for generating a voltage lower than a voltage to be actually induced at the surface of the photoreceptor drum in the course of image formation; switching means for switching a condition so that the photoreceptor is connected to the voltage generation circuit or earthed; and charger-output control means for obtaining a value of a surface potential of the photoreceptor measured by the potential sensor at the time when a voltage form the voltage generation circuit is applied to the photoreceptor by operating the switching means, estimating by arithmetic operation, on the basis of the measured value thus obtained, a value to be measured by the potential sensor when a high voltage is actually induced at the photoreceptor surface in the course of the image formation, and controlling an output from the charger based on the value estimated by the above arithmetic operatio

Abstract: In an automatic exposure device for a copying machine in which the density of an original is detected by irradiating an original by light from a lamp and detecting of the reflecting light with an optical sensor, and in accordance with the detected signal, the exposure amount of the lamp is adjusted by means of an automatic voltage adjusting circuit, and which is equipped with a heater control unit for controlling the energization of a fixing heater for fixing a toner sensible image which has been transferred on paper and a processing circuit for controlling the automatic voltage controlling circuit and heater control section, the processing circuit controlling the heater control section and being operable to maintain the energizing state of the fixing heater in a definite state, while the operation of detecting the original's density occurs with a lamp lit.

Abstract: A display device for a copying machine, wherein when a special mode such as copying with reduction and duplex copying (copying on both surfaces of a copying paper) is selected, it is judged whether the paper feed cassette set for copying is proper for the mode selected and if so, the paper feed cassette set for copying is displayed, while if not, the applicable paper feed cassettes are displayed successively, and furthermore, the paper size stacked in the paper feed cassette is displayed regardless of whether it is in the metric size system or the inch size system.

Abstract: A photoconductive drum device for electrostatic copying machines or the like includes a temperature maintaining heater bent to a cylindrical form and accommodated in the main body of a photoconductive drum. The heater is constructed with a base plate and a heat generator attached to the base plate. The base plate has a parallelogrammatic form substantially corresponding to a shape which is obtained by cutting a hollow cylinder, having a diameter approximate to the inside diameter of the drum main body, along a helical cut line and unbending the cylinder.

Abstract: An automatic document feeder, comprising a document supply section for supplying documents one by one toward a document platen, a belt feed section for transferring a supplied document to a predetermined position on the document platen to enable an image forming operation, and a document discharge section for discharging onto a document discharge tray a document fed from the belt feed section upon completion of the image forming operation, is attached so that it is upwardly turnable with respect to the document platen so as to enable manual and automatic document settings to be made selectively. Further, the automatic document feeder is designed to discriminate between manual and automatic document setting modes and to detect the presence or absence of a document at a predetermined position in the automatic document feeder when the automatic document setting mode is selected. The automatic document feeder is driven with a predetermined timing for the setting of documents.