An image forming apparatus including: a sheet feeding roller which feeds a sheet accumulated on a tray; and a hardware processor which: detects a movement speed of the sheet currently fed by the sheet feeding roller; and calculates a difference amount between the movement speed and a first reference speed, and determines a life of the sheet feeding roller based on the difference amount, wherein the hardware processor determines whether or not to use the movement speed of a first sheet for life determination based on a relationship between the movement speed of the first sheet and the movement speed of a sheet fed before the first sheet, and if the hardware processor determines not to use the movement speed of the first sheet for the life determination, the hardware processor calculates the difference amount by excluding the movement speed of the first sheet.

A transmitter transmits ultrasonic wave of a predetermined volume. A reflected ultrasonic wave receiver receives reflected ultrasonic wave, transmitted from the transmitter and reflected by a sheet. A permeated ultrasonic wave receiver receives permeated ultrasonic wave, transmitted by the transmitter and permeated through the sheet. A volume detector detects reflected volume of the reflected ultrasonic wave, and permeated volume of the permeated ultrasonic wave. The decider identifies a thickness of the sheet being transported by a transport device, and decides whether multifeed of the sheets is occurring, on a basis of a comparison result between the detected reflected volume and a reference reflected volume, and a comparison result between the detected permeated volume and a reference permeated volume.

A sheet conveyance apparatus including a transmission unit that transmits an ultrasonic wave toward a sheet and a reception unit that receives the ultrasonic wave includes a change unit that changes a distance of a conveyance path of the sheet according to sheet information about the sheet to be conveyed.

There is a need to provide an image generator and an image generation method capable of avoiding wasting a normal printed matter if any in sheets of paper output after an occurrence of waste paper. When paper contains an abnormal image, the paper is detected as waste paper based on a read result from an image read sensor. Detection of the waste paper allows an image generator to perform reprint from a print job for the waste paper. Normal-image paper may be contained in sheets of paper output between detection of the waste paper and the reprint to be performed. In this case, the normal-image paper is used as a normal printed matter and is avoided from being consumed wastefully.

The present invention is to provide a sheet conveying apparatus capable of reliably detecting a full-load state of a storage section for storing sheets discharged from a sheet conveyance path when an abnormality such as multi feed is detected, a sheet feed apparatus is provided with a multi feed sheet storage section disposed below a common conveyance path to store multi-fed sheets with multi feed detected, and a flap member rotating between a first rotation position for supporting a sheet in the common conveyance path to be able to convey to the downstream side in a conveyance direction, and a second rotation position for guiding to the multi feed sheet storage section, and determines that the multi feed sheet storage section is in a full-load state in detecting that the flap member does not return to the first rotation position.

The present invention is to provide a sheet conveying apparatus capable of reliably detecting a full-load state of a storage section for storing sheets discharged from a sheet conveyance path when an abnormality such as multi feed is detected, a sheet feed apparatus is provided with a multi feed sheet storage section disposed below a common conveyance path to store multi-fed sheets with multi feed detected, and a flap member rotating between a first rotation position for supporting a sheet in the common conveyance path to be able to convey to the downstream side in a conveyance direction, and a second rotation position for guiding to the multi feed sheet storage section, and determines that the multi feed sheet storage section is in a full-load state in detecting that the flap member does not return to the first rotation position.

There is a need to provide an image generator and an image generation method capable of avoiding wasting a normal printed matter if any in sheets of paper output after an occurrence of waste paper. When paper contains an abnormal image, the paper is detected as waste paper based on a read result from an image read sensor. Detection of the waste paper allows an image generator to perform reprint from a print job for the waste paper. Normal-image paper may be contained in sheets of paper output between detection of the waste paper and the reprint to be performed. In this case, the normal-image paper is used as a normal printed matter and is avoided from being consumed wastefully.

A transmitter transmits ultrasonic wave of a predetermined volume. A reflected ultrasonic wave receiver receives reflected ultrasonic wave, transmitted from the transmitter and reflected by a sheet. A permeated ultrasonic wave receiver receives permeated ultrasonic wave, transmitted by the transmitter and permeated through the sheet. A volume detector detects reflected volume of the reflected ultrasonic wave, and permeated volume of the permeated ultrasonic wave. The decider identifies a thickness of the sheet being transported by a transport device, and decides whether multifeed of the sheets is occurring, on a basis of a comparison result between the detected reflected volume and a reference reflected volume, and a comparison result between the detected permeated volume and a reference permeated volume.

A sheet processing apparatus is described. The sheet processing apparatus includes a housing section, a conveyance mechanism and a controller. The housing section accommodates a sheet. The conveyance mechanism conveys the sheet accommodated in the housing section to a predetermined position at the downstream side in a sheet conveyance direction. The controller controls the conveyance mechanism to remove a needle-free binding section of a sheet bundle if a conveyance jam of the sheet occurs.

A maintenance guide generation method includes: detecting occurrences of a plurality of errors; determining, on a basis of the detecting, whether the plurality of errors have occurred; when the determining determines that the plurality of errors have occurred, reading, for each of the plurality of errors, a maintenance guide corresponding to the error and including a plurality of maintenance steps; and generating a combined maintenance guide by combining the maintenance guides in a predetermined order while removing a duplicate maintenance step of the maintenance steps of the maintenance guides.