A medium transport apparatus includes a medium transport path through which a medium passes, a path state detection section configured to output a detection value corresponding to a state of the medium transport path, a control section configured to compare the detection value output by the path state detection section with a threshold value for the detection value and determine whether an abnormal condition has occurred in the medium transport path, and a storage configured to store history information including the detection value acquired in the past, in which the control section changes the threshold value based on the history information.

A medium transport apparatus includes a medium transport path through which a medium passes, a path state detection section configured to output a detection value corresponding to a state of the medium transport path, a control section configured to compare the detection value output by the path state detection section with a threshold value for the detection value and determine whether an abnormal condition has occurred in the medium transport path, and a storage configured to store history information including the detection value acquired in the past, in which the control section changes the threshold value based on the history information.

An image forming apparatus includes a conveyance unit, a detection unit, and a determination unit. The conveyance unit conveys a sheet. The detection unit detects a sound that emanates when the conveyance unit operates. The determination unit performs state determination. In a case where a volume of a sound detected by the detection unit is not higher than or equal to a predetermined sound volume, the determination unit determines that the conveyance unit is not normally operating. In a case where the detected sound volume is higher than or equal to the predetermined sound volume, the determination unit determines that the conveyance unit is normally operating.

An image forming apparatus includes a conveyance unit, a detection unit, and a determination unit. The conveyance unit conveys a sheet. The detection unit detects a sound that emanates when the conveyance unit operates. The determination unit performs state determination. In a case where a volume of a sound detected by the detection unit is not higher than or equal to a predetermined sound volume, the determination unit determines that the conveyance unit is not normally operating. In a case where the detected sound volume is higher than or equal to the predetermined sound volume, the determination unit determines that the conveyance unit is normally operating.

Provided is a sheet conveyance apparatus armored with a housing, the sheet conveyance apparatus includes: a sheet conveyor that feeds a sheet to a downstream side in a direction of conveyance; a conveyance guide that guides the sheet to be conveyed; an ultrasonic sensor that detects the sheet guided by the conveyance guide; and a shield member that is conductive, wherein the ultrasonic sensor includes: a transmitter that transmits an ultrasonic wave having a predetermined frequency; and a receiver that receives the ultrasonic wave, the transmitter and the receiver are arranged along the conveyance guide, and the shield member is disposed between the housing and the receiver in a sheet-face perpendicular direction at an ultrasonic-irradiation position of the sheet being conveyed, the shield member covering an entirety of the receiver in plan view in the sheet-face perpendicular direction.

A detection section that detects a value used for determining whether or not a jam of a paper sheet has occurred includes a sound detection unit that detects a sound and an auxiliary detection unit that detects a value different from the magnitude of a sound in the case where a jam of the paper sheet has occurred, and, in the case where the sound detection unit has detected a sound of a magnitude equal to or greater than a first threshold value, a control unit controls determines whether or not a jam of the paper sheet has occurred with reference to a detection result of the auxiliary detection unit, and controls a transport unit on the basis of a result of the determination.

A detection section that detects a value used for determining whether or not a jam of a paper sheet has occurred includes a sound detection unit that detects a sound and an auxiliary detection unit that detects a value different from the magnitude of a sound in the case where a jam of the paper sheet has occurred, and, in the case where the sound detection unit has detected a sound of a magnitude equal to or greater than a first threshold value, a control unit controls determines whether or not a jam of the paper sheet has occurred with reference to a detection result of the auxiliary detection unit, and controls a transport unit on the basis of a result of the determination.

A printer includes an apparatus body having a recording head for performing recording onto a sheet of paper. The printer also includes a unit body that is accommodated inside the apparatus body and has a path-forming surface formed at least on a portion of the periphery of the unit body. The path-forming surface forms a medium transport path. The unit body includes a plurality of openings that are in communication with a sound absorber disposed inside the unit body. The plurality of the openings are provided at least on a portion of the path-forming surface.

A sheet conveying device includes a conveyor, a sound collector, and circuitry. The conveyor conveys a sheet. The conveyor conveys a sheet in a sheet conveyance direction. The sound collector collects an operating sound generated by a conveyance of the sheet. The circuitry is to extract a feature amount of the operating sound collected by the sound collector, and determine, at different positions in the sheet conveyance direction based on the feature amount, whether an abnormal conveyance of the sheet occurs until the sheet is conveyed to a given position in the sheet conveyance direction.

Systems and methods for detecting the presence of metallic objects in media to be conveyed in a medium transport system are disclosed. One or more induction sensors are included in the medium transport system to detect the presence of metal in the transported media, with detection signals sent from the sensors to a system processing unit. An ultrasonic detector is employed in some embodiments to output another detection signal. One or more microphones may also be included, for detecting the sound created as the medium is being transported. The system processing unit analyzes various detection signals and analyzes computed sound values from the microphones, to determine the presence and location of metal in the media. A position jam detector may assist in determining jams of the media along the medium transport path.