Abstract: An image forming apparatus includes a sheet transport channel including a registration roller for supplying a sheet that is fed from a tray to an image recording section at predetermined timing. A brake forcibly stops rotation of the registration roller. A sensor senses the occurrence of an abnormality in the paper transport channel during transport of the sheet. A controller activates the brake when the sensor has detected the abnormality. Therefore, when a POP jam occurs, sheet rushing into the cleaner due to an overrun can be reliably prevented. Also, in the case of feeding a sheet to prevent a guillotine jam, sheet rushing into the image recording section due to idle rotation of the registration roller can be prevented reliably.

Abstract: In an image forming apparatus, a plurality of paper sensors are arranged along a preselected paper transport path. A jam detecting section detects jams location by location in response to the output signals of the paper sensors. A plurality of jam alarm counters are each assigned to the respective location. Each jam alarm counter counts jam information representative of jams occurred at the respective location. When the jam alarm counter counts a preselected number of jam information, jam alarm information is generated and sent to a remote control unit via a transmitting section. However, when the count of a copy counter increases to a preselected standard jam value stored in an alarm level memory, the existing count of the jam alarm counter is reset.

Abstract: An image forming apparatus is provided with a document feeder for feeding a document to an image scanning portion for scanning an image of the document, a document jam detector for detecting a jam of the document in the document feeder, and a controller for, when the document jam detector detects the jam of the document, stopping an entire image forming operation after completing a specified operation. Since the specified operation is completed upon detection of the document jam, the document to be copied when the image forming operation is resumed after removal of the jammed document can be clearly distinguished from the other. The image forming apparatus can be more rapidly resumed.

Abstract: An image forming apparatus includes an image carrier for forming an image thereon; a sheet feeding device for feeding a recording sheet to the image carrier to transfer the image onto the recording sheet; a reversing device for reversing the recording sheet on one side of which the image has been transferred and then which has been fixed, at a conveyance path in the reversing device and for feeding the recording sheet onto the image carrier to form another image on a rear side of the recording sheet; a detection device provided between the conveyance path and the image carrier for optically detecting an amount of skew or an mount of shift of the recording sheet. The apparatus further includes controller for judging the amount of skew or the amount of shift to be malfunctional when the amount of skew or the amount of shift exceeds a predetermined value, and for modifying image forming conditions thereafter.

Abstract: A method and apparatus for controlling a multiple motor drive arranged to drive printing cylinders of a printing machine sychronously decelerates each of the drives upon a failure or defect occurring in one or more of the components of the drive system such that the individual printing cylinders are decelerated in a manner synchronized with one another with respect to rotation angle. The apparatus includes a main control device which detects a failure in one of the drive system components and controls the drive units to decelerate the drive units to a standstill in accordance with a time function. The time function is determined by the rotation of the drive unit which contains the component that failed.

Abstract: A broad swing arm having a finger at its swinging end extends from an axis near a fixing unit to a tractor, overtop and next to a continuous form transport path. Any bulge or buckle caused by a paper jam and forming in the continuous form at any position between the fixing unit and tractor, and across the width of the form, is detected as the swing arm is pushed up at some point along its length, moving the finger away from a sensor monitored by a controller. Printing in the printer is stopped when the sensor detects that the finger has been moved.

Abstract: A digital copying apparatus having an image data memory and an automatic document feeder (ADF). The digital copying apparatus reads an image of an original document placed on a document platen and generates image data to be stored in the memory. When a copy sheet jam occurs during operation of an image forming section, it is determined whether or not the uncopied image data which have been generated but have not yet been copied are stored in the memory based on the detection of discharge of copy sheets from the apparatus. When all uncopied image data are stored in the memory, the copy operation is restarted using the image data stored in the memory. When all uncopied image data are not stored in the memory, the original document is discharged from a document transport path of the ADF to a discharge tray and the number of original documents to be returned to a feed tray is displayed on a display.

Abstract: An image forming apparatus for forming an image on a sheet, including a rotary endless latent image carrier, an image forming device for forming an electrostatic latent image on a latent image carrier, a developing device for developing the electrostatic latent image on the latent image carrier with powdery developers and collecting residual toners on the latent image carrier at the same time, a transfer device for transferring a developed image on the latent image carrier onto a sheet, a distribution roller having independent foam perforations for distributing residual toners on the latent image carrier when in contact with the latent image carrier after image transfer, and a power supply for supplying an AC voltage to the distribution member. The distribution member is made of a conductive foam member having a pore at a surface contacting with the latent image carrier and the roller rotates in a direction opposite to a rotational direction of the latent image carrier at a peripheral velocity of 1.1 to 1.

Abstract: An image forming apparatus including a plural number of paper transporting units including at least first and second paper transporting units, in-unit paper sensing mechanism located in the first paper transporting unit, unit-to-unit paper sensing mechanism located between the first and second paper transporting units, and drive control mechanism for controlling the operations of the plural number of the paper transporting units, wherein the drive control mechanism includes first mechanism operating such that when any of the in-unit paper sensing mechanism located in the first paper transporting unit detects a paper transport trouble, the first mechanism stops the paper transporting operation of the second paper transporting unit in response to a sensing signal indicative of the presence of a paper from the unit-to-unit paper sensing mechanism, and second mechanism stops the paper transporting operation of the first paper transporting unit upon the stop of the paper transporting operation of the second paper

Abstract: An image forming apparatus performs the printing in any of a copy mode, a facsimile mode and a print mode, having a sorter for sorting ejected sheets, wherein the operation is controlled suitably for each mode when the number of sheets stored in a bin of said sorter is over the upper limit. An image forming method using a plurality of bins, and a counter for counting the number of sheets stored in each bin, includes interrupting the print if the number of sheets stored in the bin is over the upper limit in the copy mode, and continuing the print and switching the bin, in the printer and facsimile mode, if the number of sheets is over the upper limit.

Abstract: A print detector for use in a sorter capable of detecting photoprints on each of a plurality of print carriers so as to prevent photoprints from being erroneously left on any print carrier. Print carriers are mounted at equal intervals on an endless belt adapted to be driven in one direction. Each print carrier has an optical path block mounted on its underside, i.e. the side that faces downward while the carrier is being fed downward. Each print is also provided with a transparent portion along an optical axis of light reflected obliquely upward by a reflecting end face provided at one end of the optical path block. A light emitter emits light to a light incoming end face of the optical path block. A light interceptor is provided on the optical axis of the light reflected by the reflecting end face, and an alarm device is adapted to be activated if the light interceptor fails to receive light emitted by the light emitter.

Abstract: In an image forming system, an image forming apparatus with an optional main box having a plurality of bins prevents the cover of each bin from being locked in its closed position unless papers output to all the bins are taken out. Hence, all the bins are empty when they are used later, and can be used by any users. This implements a mail box which can be efficiently used by many users.

Abstract: A transfer material detecting device contains a transfer material carrier that detachably carries a transfer material to transport the transfer material to a transfer region where a toner image of an image carrier is transferred to the transfer material; and transfer material sensors that are disposed in a moving path of the transfer material carrier and detect the existence of the transfer material carried by the transfer material carrier. The device contains at least two transfer material sensors arranged in a moving direction of the transfer material carrier at intervals that are shorter than the minimum size of the transfer material to be detected; and a device for outputting a transfer material detection signal when at least two of the transfer material sensors simultaneously detect the existence of the transfer material.

Abstract: Specific pattern images are transferred from respective photoreceptors onto the circumferential surface of a transfer belt. By detecting the specific pattern images with sensors, misregistration amounts on a transfer belt are calculated by a misregistration correction control section. Averages of the misregistration amounts for respective colors are calculated for each region that corresponds to a single recording medium placed on the transfer belt. The scanning timings of image writing units are controlled by an image signal output control section based on the calculated averages. As a result, toner images formed on the respective photoreceptors are transferred to proper positions of any recording medium being placed on the transfer belt.