A medium feeding device includes a medium placing portion, a feeding roller that feeds paper, a medium movement detecting portion that is positioned on a placing region of the paper of the medium placing portion in a medium feeding direction and is capable of detecting movement of the paper being fed in a width direction intersecting the medium feeding direction, and a controller that stops feeding of the paper in a case in which a physical quantity relating to movement of paper in the width direction exceeds a predetermined threshold based on a detected result by the medium movement detecting portion.

A recording medium conveyance device includes a storage, a conveyer that conveys a conveyed object, an ultrasonic sensor that outputs a value indicating an attenuation amount of an ultrasonic wave caused by the conveyed object, and a hardware processor. The hardware processor executes a type detection process of detecting a type of the conveyed object based on output of the ultrasonic sensor and storing the type in the storage and an overlay detection process of detecting whether the conveyed object is in an overlay state in which a gap is present based on output of the ultrasonic sensor, and switches to either one of the type detection process and the overlay detection process. The hardware processor executes the type detection process when the type is not stored in the storage and executes the overlay detection process when the type is stored in the storage.

A conveying device includes a first pair of nipping rollers, a second pair of nipping rollers, a position corrector configured to correct a position of a recording medium in a width direction of the recording medium, an end position detector configured to detect an end position of the recording medium in the width direction, and circuitry configured to, in adjustment of the end position detector, stop conveying the recording medium in response to arrival of a leading end of the recording medium at the end position detector, cause the position corrector to move the recording medium toward an outside of the conveyance passage in the width direction to a position at which the end position detector is covered by the recording medium, adjust the output of the end position detector, and cause the end position detector to detect the recording medium.

A detection unit includes a first contact member that comes into contact with a surface of a recording material and a second contact member that comes into contact with the other surface of the recording material, and the first contact member and the second contact member face each other and are capable of nipping the recording material. The first contact member and the second contact member are movable in a direction in which the first contact member and the second contact member nip the recording material. The first contact member and the second contact member are rotatable about an axial line that extends in a direction in which the recording material is conveyed.

A sheet detecting device usable with a sheet feeding device for feeding a sheet, the sheet detecting device includes a common light emitter; a first light receptor and a second light receptor for receiving the light emitted by the common light emitter and output a signal in response to the reception of the light; a first detector configured to detect presence or absence of the sheet by switching the signal outputted by light receptor, in response to the sheet blocking or reflecting the light emitted by the common light emitter; a movable portion capable of being moved by the sheet which is moving; and a second detector configured to detect presence or absence of the sheet by switching the signal outputted by the second light receptor, in response to the movable portion forming or blocking a optical path for the light emitted by the common light emitter.

A sheet conveying device, which is included in an image forming apparatus, includes a pair of rollers configured to convey a sheet in a sheet conveyance passage, a detector configured to optically detect an attitude of the sheet, one of a rotation device to rotate the pair of rollers in a direction parallel to a plane of the sheet and a moving device to move the pair of rollers in a width direction, and a controller configured to correct the attitude of the pair of rollers at a time interval, based on a detection result obtained by the detector. The controller performs the correcting operation by setting, according to reflectance of the sheet, at least one of a light emission time of the detector, the time interval of the correcting operation, light emission intensity of the detector and a conveying speed of the sheet.

A sheet conveyance device includes a shape detecting portion, and a switch control portion. The shape detecting portion detects a shape of a sheet at a detection position located between a first conveyance member and an image forming position in a sheet conveyance path. The switch control portion, when the first conveyance member is determined to be in an accelerated state where it is accelerated from a stopped state to a driven state, switches an detection interval at which the shape of the sheet is detected by the shape detecting portion, to a first interval that corresponds to a rotation speed of the first conveyance member, and when the first conveyance member is determined to be in a decelerated state where it is decelerated from the driven state to the stopped state, switches the detection interval to a predetermined second interval.

An edge detection device that detects an edge position in a width direction orthogonal to a conveying direction of a conveyance object, and includes: a photoelectric converter that is arranged in a conveyance path of the object and includes photoelectric conversion elements aligned along the width direction; a binarizer that binarizes an output from each of the photoelectric conversion elements by threshold comparison; a detector that detects a position of the photoelectric converter at which a binarized value is switched; a storage that stores therein a detection range as a range used for edge detection among the photoelectric conversion elements for each size of the object; and a determiner that reads out the detection range corresponding to the size of the object from the storage and determines a position detected by the detector within the detection range to be an edge position in the width direction of the object.

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.

Provided are a medium ejection apparatus, a control method, and a control program to enable precise determination of whether abnormal ejection of a medium has occurred. A medium ejection apparatus includes an ejection roller to eject a medium, a tray to stack the medium ejected by the ejection roller, a first optical sensor located above the ejection roller and including a first light emitter to emit light toward the tray and a first light receiver to generate a first optical signal based on received light, a second optical sensor located above the ejection roller and including a second light emitter to emit light toward a downstream side of the tray in a medium ejecting direction and a second light receiver to generate a second optical signal based on received light, a determination module to determine whether abnormal ejection of the medium has occurred based on the first optical signal and the second optical signal, and a control module to execute abnormality processing when it is determined that abnormal ejection of the medium has occurred.