An automatic detection method for a paper size is disclosed. a plurality of mark points is set on a paperweight along a paperweight direction that is different from a feeding direction. The disclosure senses a plurality of row images combining into a scan image during a paper passing between the paperweight and an image sensor, determines an edge length of the paper based on a range of the mark points covered by the paper, and determines a paper size based on the edge length. The disclosure can effectively detect the paper size without any additional sensors.

A control device of an image forming system including an image former that forms an image on a recording medium formed of a continuous sheet or a long sheet includes a hardware processor that calculates a width of the recording medium on a downstream side of a fixer included in the image former in a transport direction of the recording medium and outputs a shrinkage amount or a shrinkage rate of the recording medium in the transport direction due to the fixer based on the width of the recording medium and shrinkage characteristic information of the recording medium.

A post-processing device includes an output unit that outputs a medium; a stacking unit on which the medium that is output is stacked; and a blow-out unit that is disposed below the output unit and that blows gas toward the medium that is output, wherein an amount of the gas blown is adjusted in accordance with a type of the medium.

A transport device includes: a first transport body; a second transport body that is movable between a contact position and a separate position with respect to the first transport body and that nips a transported material with the first transport body at the contact position; and a transport section that includes a holder to hold a leading end portion of the transported material and that transports the transported material toward a nip region where the first transport body and the second transport body nip the transported material in a state in which the second transport body is located at the separate position. After holding of the leading end portion by the holder for the transported material transported by the transport section has been released, the second transport body nips the transported material with the first transport body and transports the transported material.

An image forming apparatus includes an image forming portion, a belt, a plurality of stretching rollers including an inner roller and an upstream roller, an outer member, an urging member, a first position changing mechanism, a storing portion, a controller, and an operating portion. The controller controls the first position changing mechanism on the basis of a kind of a recording material on which an image is formed, first set information stored in the storing portion, and first input information for changing setting of a position of the urging member inputted to the controller through the operating portion.

A fixing device includes a separator disposed downstream from a nip former in a recording medium conveyance direction and isolated from a pressure rotator via a fixing belt. The separator stretches the fixing belt. A presser is interposed between a fixing nip formed between the living belt and the pressure rotator and an upstream end of the separator in a rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator. A pressure adjuster, contacting the pressure rotator, changes a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt. A presser position adjuster, contacting the presser, changes a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator.

An image forming apparatus includes an image forming unit configured to form an image on a recording material based on first image data; a controller configured to control an image forming operation by the image forming unit; an acquisition unit configured to acquire property information related to a property of the recording material; a setting unit configured to set a control value to be used in the image forming operation; a reader configured to read an image formed on the recording material by the image forming unit and to output second image data; and a comparison unit configured to compare the first image data to the second image data, wherein the setting unit is further configured to set the control value based on a comparison result from the comparison unit and the property information.

A recording material determination apparatus includes a transmission unit, a reception unit, and a determination unit. The transmission unit transmits an ultrasonic wave to a recording material. The reception unit vibrates when the reception unit receives the ultrasonic wave having been transmitted from the transmission unit and having passed through the recording material, and outputs a signal corresponding to a vibration state. The determination unit determines a basis weight of the recording material in accordance with the signal output from the reception unit. A resonance frequency of the reception unit differs from a resonance frequency of the transmission unit, and the reception unit is capable of receiving a sound wave in an ultrasonic range and a sound wave in an audible range.

A post-processing device includes an output unit that outputs a medium; a stacking unit on which the medium that is output is stacked; and a blow-out unit that is disposed below the output unit and that blows gas toward the medium that is output, wherein an amount of the gas blown is adjusted in accordance with a type of the medium.

An image forming apparatus includes a heating rotary member, a pressure rotary member, a nip portion formed by the rotary members, a temperature adjustment control section controlling a temperature of the heating rotary member to a target temperature, a cleaning web removing toner adhering to the heating rotary member, and a controller selectively executing one of a cleaning mode and a non-cleaning mode. A first basis weight and a second basis weight greater than the first predetermined basis weight are set, in a job that mixedly uses recording media with the first and second basis weights. When the controller executes the non-cleaning mode, the temperature adjustment control section sets a target temperature of a recording medium with a basis weight less than or equal to the first basis weight to a temperature lower than a target temperature of the recording medium in the cleaning mode.