Abstract: A sheet processing apparatus capable of properly stacking sheets by detecting abnormality of a sheet stacking state during a sheet stacking operation to thereby prevent stack overflow. In the sheet processing apparatus, a conveyed sheet is stacked on a stacking tray. A sheet presence sensor detects a sheet on a sheet stacking surface of the stacking tray. A sheet height reduction sensor detects sheets within a predetermined distance downward from the uppermost surface of sheets stacked on the stacking tray. When the sheet presence sensor detects no sheet, and the sheet height reduction sensor detects a sheet during an operation for discharging a plurality of sheets onto the stacking tray, it is determined that an abnormal stacking state has occurred, and conveyance of a sheet is stopped.

Abstract: Provided is a puncher having activating/inactivating switch for post-processing function. The puncher prevents undesirable post processing even if the switch indicates activation of the post processing. When a puncher which is registered in the image forming apparatus is attached to the puncher, the puncher obtains information indicating whether or not to the post processing using a punch die is activated or not. When the obtained information indicates that the post processing using the punch die is inactivated, even if the switch indicates activation of the post processing, the post processing is not performed.

Abstract: To prevent sheets from being allowed to be delivered after activation of a system when over-stacking has been detected before the activation of the system, a post-processing apparatus includes a stacking tray configured to allow sheets subjected to predetermined processing to be stacked thereon. The post-processing apparatus determines whether or not additional sheets are allowed to be stacked onto the stacking tray based on the number of sheets stacked on the stacking tray. The determination result indicating that the additional sheets are prohibited to be stacked onto the stacking tray is stored in a nonvolatile RAM. The post-processing apparatus determines, after being activated, whether or not the determination result is stored in the nonvolatile RAM, and determines that the additional sheets are prohibited to be stacked onto the stacking tray when the determination result is stored in the nonvolatile RAM.

Abstract: An image forming apparatus includes an image forming station; a mounting portion for mounting one of fixing devices each including a first roller and a second roller which cooperate to form a nip for fixing a toner image on a sheet fed from the image forming station, a rubbing roller configured to rub a surface of the first roller, a storing portion capable of storing information; a counter for counting sheets fed to the fixing device mounted on the mounting portion and to store number indicative of the number counted by the counter in the storing portion of the fixing device; and an executing portion for effecting a rubbing treatment to the first roller of the fixing device, when the number counted by the counter on the basis of the number in the storing portion of the fixing device mounted on the mounting portion exceeds a predetermined number.

Abstract: A sheet processing apparatus that is capable of facilitating a process by eliminating waste of a result even if a translucent sheet is conveyed. A conveyance unit conveys a sheet received from an image forming apparatus. An optical sensor detects a sheet end conveyed. An alignment unit aligns sheets based on information detected by the optical sensor. A post-process unit performs a post-process to the sheets aligned. An input unit inputs sheet information about a type of the sheet to be received from the image forming apparatus. A control unit stops sheet conveyance when the sheet information indicates a first type sheet and when the optical sensor cannot detect the sheet end, and continues sheet conveyance when the sheet information indicates a second type sheet of which transmittance is higher than the first type sheet and when the optical sensor cannot detect the sheet end.

Abstract: A punching apparatus capable of performing update work for updating maintenance information, irrespective of whether or not a punch die is mounted. A puncher includes a punching unit that punches a sheet using an exchangeable punch die provided with a die memory, and a CPU that detects mounting of a punch die in the punching unit. The CPU receives an update request requesting update of maintenance information stored in the die memory of the punch die. If mounting of the punch die is detected, when the update request designating the punch die is received, the CPU updates the maintenance information of the punch die based on the update request. If mounting of the punch die is not detected, the CPU updates the maintenance information of the punch die when mounting of the punch die is detected.

Abstract: A sheet feeding apparatus includes a containing unit, a lifting and lowering unit, a loosening unit, a feed unit, a sheet-surface detection unit, an aligning member, a trailing-edge detection unit, a double-feed detection unit, and a control unit. Sheets, of a sheet bundle contained in the containing unit and lifted and lowered, are loosened by blowing air into the sheet bundle and fed. An end face of the contained sheet bundle is aligned on a trailing-edge side. The trailing-edge detection unit moves with the aligning member and detects a sheet surface of a top of the sheet bundle on the trailing-edge side. Where double feed from the containing unit is detected, a detection operation detects, in consideration of a trailing-edge detection unit result, whether the aligning member is located at a position at which the end face of the sheet bundle on the trailing-edge side is aligned.

Abstract: A sheet processing apparatus that is capable of properly performing fold line processing at a position depending on a sheet bundle. In a sheet processing apparatus, sheets sequentially received from an image forming apparatus are stacked on a bookbinding processing tray to form a sheet bundle. The sheet bundle is folded at the center thereof, and is conveyed to a processing position. A press unit moves along a fold line portion of the sheet bundle to thereby perform flattening processing for flattening the fold line portion by pressing the fold line portion from a direction orthogonal to a thickness direction. A first pressing strength set by a user using the image forming apparatus and the second pressing strength acquired information on the sheet bundle are compared with each other, and the processing position is determined based on a result of the comparison.

Abstract: A sheet conveying apparatus that restricts conveyance of sheets to a post-processing apparatus which has become incapable of continuing a post-processing operation. The sheet conveying apparatus is communicably connected to the post-processing apparatus that performs post-processing on a sheet bundle formed by sheets. The sheet conveying apparatus includes a conveying unit for conveying sheets and an escape tray for receiving conveyed sheets which are not conveyed to the post-processing apparatus. A value corresponding to the number of sheet bundles formed by conveyed sheets is counted. A CPU circuit section determines based on communication with the post-processing apparatus whether or not the post-processing operation can be continued thereby. When it is determined that the post-processing operation cannot be continued, the CPU circuit section switches the sheet conveying destination from the post-processing apparatus to the escape tray, based on the counted value.

Abstract: A sheet feeding apparatus includes a containing unit, a lifting and lowering unit, a loosening unit, a feed unit, a sheet-surface detection unit, an aligning member, a trailing-edge detection unit, a double-feed detection unit, and a control unit. Sheets, of a sheet bundle contained in the containing unit and lifted and lowered, are loosened by blowing air into the sheet bundle and fed. An end face of the contained sheet bundle is aligned on a trailing-edge side. The trailing-edge detection unit moves with the aligning member and detects a sheet surface of a top of the sheet bundle on the trailing-edge side. Where double feed from the containing unit is detected, a detection operation detects, in consideration of a trailing-edge detection unit result, whether the aligning member is located at a position at which the end face of the sheet bundle on the trailing-edge side is aligned.

Abstract: An image forming apparatus capable of improving productivity in a print job mixedly involving single-sided printing and double-sided printing. Sheets are fed one by one to an image forming section. When double-sided printing is to be performed, a sheet having an image formed on the first side thereof by the image forming section is re-fed thereto so as to have an image formed on the second side thereof. When a sheet for double-sided printing exists, which is posterior in page order to a sheet for single-sided printing, an image forming order is changed such that the first side of the sheet for double-sided printing is subjected to image formation prior to the sheet for single-sided printing. When it is predicted that a state will occur in which the sheet for single-sided printing cannot be fed, the image forming order is not changed.

Abstract: An image forming apparatus capable of improving productivity in a print job mixedly involving single-sided printing and double-sided printing. Sheets are fed one by one to an image forming section. When double-sided printing is to be performed, a sheet having an image formed on the first side thereof by the image forming section is re-fed thereto so as to have an image formed on the second side thereof. When a sheet for double-sided printing exists, which is posterior in page order to a sheet for single-sided printing, an image forming order is changed such that the first side of the sheet for double-sided printing is subjected to image formation prior to the sheet for single-sided printing. When it is predicted that a state will occur in which the sheet for single-sided printing cannot be fed, the image forming order is not changed.

Abstract: An image forming system having: a sheet feeding unit which cuts a roll sheet and feeds cut sheets; a stack unit which stacks and stores the sheets fed by the sheet feeding unit and feeds the stored sheets; an image forming portion which forms an image on the sheets fed from the stack unit; and a controlling unit configured to control the feeding unit and the stack unit so that the stack unit feeds a sheet stored in the stack unit to the image forming portion when the sheet feeding unit feeds a sheet to the stack unit so as to stack the sheet from the sheet feeding unit into the stack unit.

Abstract: A sheet conveying system which is capable of preventing a jammed sheet from being mixed with processed sheets, reducing waste in sheets and toners, and further alleviating the user's operations, when jamming has occurred during passing of a sheet between respective sheet conveying devices of upstream and downstream apparatuses. A puncher control section of a puncher as an upstream apparatus of the system issues a passing completion notification as to the passing of a sheet to a staple stacker control section of a staple stacker as a downstream apparatus of the system. Upon reception of the notification, when the staple stacker control section determines that the parameter of auxiliary information of the notification indicates an abnormal discharge of the sheet from the puncher, the staple stacker stops the conveyance of the sheet.

Abstract: An image forming system comprises a selection unit for selecting a post-processing apparatus that executes post-processing to a recording medium on which an image is formed from among a plurality of post-processing apparatuses, and a selection limitation unit for determining an insertion apparatus whose supply of the insertion medium to be limited for a selected post-processing apparatus and limiting selection of the insertion apparatus.

Abstract: A configuration of an image forming system that includes an image forming apparatus and at least one of a paper feed apparatus and a post-process apparatus is defined based on system configuration information including a combination of identification information for the apparatuses and setting information for the order of arrangement of the apparatuses corresponding to the identification information without using a dedicated line connection.

Abstract: When image forming is to be successively performed on recording sheets having different sizes, an image forming apparatus suitably executes adjustment processing on a fixing apparatus or the like used in the image forming, and maintains image quality as well as suppresses a drop in productivity. To accomplish this, the image forming apparatus specifies the size of a printing material onto which an image is to be performed, and with use of the specified printing material size and the size of printing materials on which images have been formed immediately previously, determines whether it is necessary to execute adjustment processing for maintaining image quality. Specifically, adjustment processing is executed only if the size of the printing material on which an image is to be formed is greater than the size of the printing materials on which images were formed immediately previously.

Abstract: An image forming apparatus/method transports a sheet to an image forming unit that can form images on both sheet sides. The sheet is fed to the image forming unit at a predetermined image formation start timing for the first side image formation, thereafter is reversed, and re-fed to the image forming unit for the second side image formation while the first side image-formed sheet waits at least one of sheet waiting positions. A full state, where all the sheet waiting positions are full of the first side image-formed sheets, is detected. The number of sheets transported is controlled so that it is greater than the number of the sheet waiting positions. When the full state is detected, the sheet re-feeding is controlled so that a head sheet among the first side image-formed sheets waiting at the sheet waiting positions is fed in advance of the predetermined image formation start timing.

Abstract: An image forming apparatus capable of reducing damage in a fixing section and printing a high-quality image on a sheet at low cost without reducing productivity. A sheet shifting mechanism is arranged upstream of a transfer roller and moves the sheet in a sheet lateral direction orthogonal to the sheet conveying direction. In order to change a position at which a sheet passes through a fixing roller, the sheet shifting mechanism is controlled for every conveyance of a predetermined number of sheets, whereby sheet movement in the sheet lateral direction is controlled. A correction amount for an error due to sheet shifting by the sheet shifting mechanism is stored for each of sheet shift positions. An image forming position in the sheet lateral direction of a photosensitive drum is shifted on the basis of the sheet shift position and the stored correction amount.

Abstract: When image forming is to be successively performed on recording sheets having different sizes, an image forming apparatus suitably executes adjustment processing on a fixing apparatus or the like used in the image forming, and maintains image quality as well as suppresses a drop in productivity. To accomplish this, the image forming apparatus specifies the size of a printing material onto which an image is to be performed, and with use of the specified printing material size and the size of printing materials on which images have been formed immediately previously, determines whether it is necessary to execute adjustment processing for maintaining image quality. Specifically, adjustment processing is executed only if the size of the printing material on which an image is to be formed is greater than the size of the printing materials on which images were formed immediately previously.