A medium transporting apparatus includes a feeding roller that rotates to transport a medium along a transportation path, an electrode installed downstream of the feeding roller on the transportation path and having conductivity, and an electric charge detecting circuit that outputs a signal having a magnitude corresponding to an amount of an electric charge, which moves from the medium to the electrode after the medium being transported along the transportation path comes into contact with the electrode.

A medium transporting apparatus includes a feeding roller that rotates to transport a medium along a transportation path, an electrode installed downstream of the feeding roller on the transportation path and having conductivity, and an electric charge detecting circuit that outputs a signal having a magnitude corresponding to an amount of an electric charge, which moves from the medium to the electrode after the medium being transported along the transportation path comes into contact with the electrode.

A medium conveying apparatus includes a plurality of feed rollers, each feed roller rotating independently at a respective speed to feed a medium, a first sensor located on a downstream side of the plurality of feed rollers in a medium conveying direction and also in a central part in a direction perpendicular to the medium conveying direction, to detect the medium, a second sensor and a third sensor located on both sides of the first sensor in the direction perpendicular to the medium conveying direction, to respectively detect the medium, and a processor to change the speed of one of the plurality of feed rollers at least until the first sensor detects the medium when any of the second sensor or the third sensor detects the medium and the first sensor does not detect the medium within a predetermined time.

A medium conveying apparatus includes a plurality of feed rollers, each feed roller rotating independently at a respective speed to feed a medium, a first sensor located on a downstream side of the plurality of feed rollers in a medium conveying direction and also in a central part in a direction perpendicular to the medium conveying direction, to detect the medium, a second sensor and a third sensor located on both sides of the first sensor in the direction perpendicular to the medium conveying direction, to respectively detect the medium, and a processor to change the speed of one of the plurality of feed rollers at least until the first sensor detects the medium when any of the second sensor or the third sensor detects the medium and the first sensor does not detect the medium within a predetermined time.

A sheet feeding device includes a sheet feeding roller, a following roller, a rotational speed detection part, and a control part. The rotational speed detection part is configured to detect a rotational speed of the following roller. The control part is configured to accelerate a rotation of the sheet feeding roller and to adjust a sheet interval. The control part obtains a rotational rate of the following roller to the sheet feeding roller based on the rotational speed of the following roller, obtains an actual linear velocity of the sheet based on the rotational rate of the following roller and a theoretical linear velocity of the sheet after accelerating the rotation of the sheet feeding roller, and then adjusts the sheet interval based on the actual linear velocity of the sheet.

An image forming apparatus includes a feeding unit, a detection unit provided downstream of the feeding unit, a measurement unit that measures a measured time from the start of conveyance of a recording material to the detection of the recording material, and a determination unit that performs renewal determination for determining whether the feeding unit has been replaced with a new feeding unit. Thus, replacement of the feeding unit with a new feeding unit can automatically be detected.

An image forming apparatus includes a feeding unit, a detection unit provided downstream of the feeding unit, a measurement unit that measures a measured time from the start of conveyance of a recording material to the detection of the recording material, and a determination unit that performs renewal determination for determining whether the feeding unit has been replaced with a new feeding unit. Thus, replacement of the feeding unit with a new feeding unit can automatically be detected.

A sheet processing apparatus comprises a roller disposed in a sheet conveyance path; a sheet sensor disposed in the sheet conveyance path and configured to detect conveyance of sheets and generate sensor information indicative of detection; and a controller. The controller is configured to, for each sheet of a predetermined number of sheets of a plurality of sheets conveyed by the roller, use the sensor information to generate an individual sheet-conveyance dataset indicating a sheet passage interval; and store the individual sheet-conveyance dataset in data storage. The controller is further configured to, after the roller conveys the predetermined number of sheets, calculate a summary sheet-conveyance dataset including sheet passage interval statistics for the predetermined number of sheets; store the summary sheet-conveyance dataset in the data storage; discard the individual sheet-conveyance datasets from the data storage; and evaluate the sheet passage interval statistics to determine whether to modify the predetermined number of sheets.

Provided is an image forming device including: an image heating portion which includes a heater including a plurality of heating blocks divided in a direction orthogonal to a conveying direction of a recording material and heats an image formed on the recording material; a temperature sensing element which senses a temperature of each of the heating blocks; and a control portion which controls electric power supplied to each of the heating blocks on the basis of the temperature sensed by the temperature sensing element, wherein the control portion determines whether or not the recording material is in a skewed state in which the recording material is conveyed in an obliquely inclined state with respect to the conveying direction on the basis of a variation of the electric power supplied to end heating blocks for heating end portions of the recording material among the plurality of the heating blocks.

Provided is an image forming device including: an image heating portion which includes a heater including a plurality of heating blocks divided in a direction orthogonal to a conveying direction of a recording material and heats an image formed on the recording material; a temperature sensing element which senses a temperature of each of the heating blocks; and a control portion which controls electric power supplied to each of the heating blocks on the basis of the temperature sensed by the temperature sensing element, wherein the control portion determines whether or not the recording material is in a skewed state in which the recording material is conveyed in an obliquely inclined state with respect to the conveying direction on the basis of a variation of the electric power supplied to end heating blocks for heating end portions of the recording material among the plurality of the heating blocks.