An image forming apparatus includes: an image former that forms an image on a continuous paper; a fixing unit that includes a pair of rotatable members and that nips the continuous paper between the rotatable members to convey the paper and fix the image formed on the paper by the image former; a conveying member different from the rotatable members; and a hardware processor. The image forming apparatus performs a paper conveying mode in which the image former does not form an image and at least the conveying member conveys the continuous paper. In the paper conveying mode, the hardware processor determines to press the rotatable members against each other or to separate the rotatable members from each other according to a predetermined criterion and, based on the determination, conveys the continuous paper while keeping the rotatable members pressed against each other or separated from each other.

A device for detecting a travel distance of a sheet is provided. The device includes a light source for irradiating the sheet surface; an imaging sensor for capturing an image of a pattern of the sheet surface by light reflected from the sheet; a discrete Fourier transformation portion for performing discrete Fourier transformation on two patterns obtained by image capturing at a time interval by the imaging sensor; a high wave number component removal portion for using a threshold determined based on a cycle of concave-convex of the sheet surface to remove a high wave number component from the two patterns having been subjected to the discrete Fourier transformation; and a travel distance calculation portion for determining a travel distance of the sheet based on a phase relationship between the two patterns from which the high wave number component removal portion has removed the high wave number component.

An image forming apparatus includes: a first rotatable member; a second rotatable member that presses against the first rotatable member in a pressed state and separates from the first rotatable member in a separated state; and a hardware processor that sets a target speed of the second rotatable member based on a change in speed of the second rotatable member between a first speed in the separated state and a second speed in the pressed state.

An image forming apparatus includes: a first rotatable member; a second rotatable member that presses against the first rotatable member in a pressed state and separates from the first rotatable member in a separated state; and a hardware processor that sets a target speed of the second rotatable member based on a change in speed of the second rotatable member between a first speed in the separated state and a second speed in the pressed state.

A system for an electrophotographic image forming device includes a toner container having a reservoir for storing toner and an impact member configured to selectively impart an impulse force on the toner container to cause vibration of the toner container. A sensor is configured to sense the vibration of the toner container upon the impact member imparting the impulse force on the toner container. Processing circuitry in communication with the sensor is configured to determine an estimate of an amount of toner in the reservoir based on the sensed vibration of the toner container.

An image formation apparatus includes a conveyor configured to convey a moving element on which an image is formed, a generator configured to generate a first image and a second image by shooting the conveyed moving element at different timing, a detector configured to sense a first distance between the generator and the moving element at the time of shooting of the first image and sense a second distance between the generator and the moving element at the time of shooting of the second image, and a hardware processor configured to calculate a speed of conveyance of the moving element based on the first image, the second image, the first distance, and the second distance, and output the speed of conveyance.

A sheet feeder includes a roller, a reflector, a sensor, and a rotating speed detector. The reflector is integrally attached to the roller, the reflector including first reflecting surfaces and second reflecting surfaces arranged alternately along a circumference direction of the roller. The sensor includes a light emitter and a light receiver. The rotating speed detector is configured to detect a rotating speed of the roller based on a result of the detection by the sensor. Each of the first reflecting surfaces reflects the inspection light at a first reflection ratio, and provides a first reflection light path along which the inspection light is directed to the light receiver. Each of the second reflecting surfaces reflects the inspection light at a second reflection ratio smaller than the first reflection ratio, and provides a second reflection light path along which the inspection light is directed outside the light receiver.

An image forming apparatus includes: a plurality of photoreceptors; a plurality of exposure heads provided so as to correspond to the plurality of photoreceptors, respectively, each of the plurality of exposure heads including a plurality of light emitting units configured to emit light for exposing the corresponding photoreceptor, the plurality of light emitting units being arranged along a rotation axis line of the corresponding photoreceptor; and a generation unit configured to generate a line synchronization signal for each of the plurality of exposure heads to control a light emission timing in a rotating direction of the corresponding photoreceptor, the generation unit being configured to adjust a cycle of the line synchronization signal in accordance with each of the plurality of exposure heads.

An image forming apparatus includes a first sensor to detect at least one of a position of an image on a sheet or a length of the sheet; a first conveyor upstream or downstream of the first sensor in a conveyance direction; a fixing device; and circuitry. The first conveyor includes: a rubber belt; a driving roller within the rubber belt to rotate the rubber belt; a driven roller outside the rubber belt and driven by the rubber belt to convey the sheet in the conveyance direction; and a second sensor to measure a rotational speed of the driven roller. The fixing device is upstream of the first conveyor in the conveyance direction. The fixing device fixes toner onto the sheet. The circuitry is configured to control the first conveyor to convey the sheet at a target linear speed based on the rotational speed measured by the second sensor.

A sheet feeder includes a roller, a reflector, a sensor, and a rotating speed detector. The reflector is integrally attached to the roller, the reflector including first reflecting surfaces and second reflecting surfaces arranged alternately along a circumference direction of the roller. The sensor includes a light emitter and a light receiver. The rotating speed detector is configured to detect a rotating speed of the roller based on a result of the detection by the sensor. Each of the first reflecting surfaces reflects the inspection light at a first reflection ratio, and provides a first reflection light path along which the inspection light is directed to the light receiver. Each of the second reflecting surfaces reflects the inspection light at a second reflection ratio smaller than the first reflection ratio, and provides a second reflection light path along which the inspection light is directed outside the light receiver.