A transport device includes: a medium support unit having a placement surface where a sheet-like medium is placed; a transport unit supplied with the medium placed at the placement surface and transporting the medium in a transport direction along a sheet surface of the medium; an ultrasonic transmitting unit provided at a part of the medium support unit and transmitting an ultrasonic wave; an ultrasonic receiving unit provided at another part of the medium support unit, and receiving the ultrasonic wave and outputting a received signal; and a floating detection unit determining whether a floating of the medium from the placement surface is present or not, based on the received signal.

A transport device includes: a medium support unit having a placement surface where a sheet-like medium is placed; a transport unit supplied with the medium placed at the placement surface and transporting the medium in a transport direction along a sheet surface of the medium; an ultrasonic transmitting unit provided at a part of the medium support unit and transmitting an ultrasonic wave; an ultrasonic receiving unit provided at another part of the medium support unit, and receiving the ultrasonic wave and outputting a received signal; and a floating detection unit determining whether a floating of the medium from the placement surface is present or not, based on the received signal.

A paper conveyance device includes a roller, paper feed sensor, registration sensor, and controller. At a first time point at which specified time from start of draw of paper by the roller to arrival of the paper at the registration sensor has passed, when a detection result by the registration sensor is absence of the paper and a detection result by the paper feed sensor is presence of the paper, and the detection result by the paper feed sensor is the absence at a second time point at which standby time has passed from the first time point, the controller sets a safe paper feed mode in which the draw of the paper by the roller is started at a delay time point at which delay time has passed since a switching time point at which the detection result by the registration roller is switched from the presence to absence.

The present invention is to provide a configuration facilitating removal of a sheet stopped on a conveying belt. In a sheet conveying apparatus that conveys a sheet using a conveying belt and balls, a sheet may be jammed and stopped on the conveying belt. In this case, it is difficult for a user to take out the sheet through a take-out port if the sheet is nipped by conveying roller pairs disposed upstream and downstream relative to the conveying belt in a sheet conveying direction. Thus, conveying roller pairs and the conveying belt are operated such that the sheet, which is stopped on the conveying belt and hence should be taken out through the take-out port, is brought into a state of being nipped only by the conveying belt and balls.

A medium transport device includes a feeding roller that feeds a recording medium, a transport roller that transports the recording medium toward a recording head, and a transport motor which is a common driving source for the feeding roller and the transport roller. The medium transport device includes a power transmission mechanism that transmits power of the transport motor to the feeding roller, and a control section that controls a current of the transport motor. The control section measures a current value flowing through the transport motor during driving as a measured current value, and adds a predetermined offset value to the measured current value to set a second limit value as a limit value of the current supplied to the transport motor.

A medium transport device includes a feeding roller that feeds a recording medium, a transport roller that transports the recording medium toward a recording head, and a transport motor which is a common driving source for the feeding roller and the transport roller. The medium transport device includes a power transmission mechanism that transmits power of the transport motor to the feeding roller, and a control section that controls a current of the transport motor. The control section measures a current value flowing through the transport motor during driving as a measured current value, and adds a predetermined offset value to the measured current value to set a second limit value as a limit value of the current supplied to the transport motor.

A document feeding device includes a document placement unit at which a document is placed, a feeding roller for feeding the document, and a ranging sensor for measuring a distance to the document located most upward on the document placement unit. A control unit stops feeding the document by the feeding roller based on post-processing distance data obtained by statistically processing time series data of the distance measured by the ranging sensor.

An image forming apparatus includes an image forming unit; a reverse conveying roller; a discharge unit including a reverse conveying path, an openable and closable member, an open/close sensor, a discharge tray, a sheet conveyance unit, and a failure detector; and a controller. If the controller determines that the sheet conveyance unit is in failure based on a detection result of the failure detector and determines that the openable and closable member is closed based on a detection result of the open/close sensor, the controller prohibits discharge of the sheet to the discharge tray and permits conveyance of the sheet to the reverse conveying path, and if the controller determines that the sheet conveyance unit is in failure and determines that the openable and closable member is open, the controller prohibits the conveyance of the sheet to the reverse conveying path.

An image forming apparatus includes an image forming unit; a reverse conveying roller; a discharge unit including a reverse conveying path, an openable and closable member, an open/close sensor, a discharge tray, a sheet conveyance unit, and a failure detector; and a controller. If the controller determines that the sheet conveyance unit is in failure based on a detection result of the failure detector and determines that the openable and closable member is closed based on a detection result of the open/close sensor, the controller prohibits discharge of the sheet to the discharge tray and permits conveyance of the sheet to the reverse conveying path, and if the controller determines that the sheet conveyance unit is in failure and determines that the openable and closable member is open, the controller prohibits the conveyance of the sheet to the reverse conveying path.

A method and apparatus for processing mail is provided. A feeder serially feeds envelope from a stack of mail. Two cutters at a cutting station cuts one or two edges of the envelopes. As the envelopes travel from the feeder to the cutters the envelope is jogged on two edges to justify the contents with the envelopes. Additionally, an improved feeder is provided to reduce the number of jams created when feeding the envelopes from the stack.