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.

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.

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 sheet feeding device includes a sheet loading portion which is capable of elevating operation and on which a sheet is loaded, a feeding member for feeding the sheet loaded on the sheet loading portion, the feeding member being capable of elevating movement between a contacting position in contact with the sheet and a distanced position distanced upward from the sheet, and a control portion that controls the elevating operation of the sheet loading portion and the elevating movement of the feeding member. When the feeding member at the contacting position moves to the distanced position, the feeding member is distanced upward from the sheet loaded on the sheet loading portion after the sheet loading portion starts a descending operation.

A sheet feeding device includes a sheet loading portion which is capable of elevating operation and on which a sheet is loaded, a feeding member for feeding the sheet loaded on the sheet loading portion, the feeding member being capable of elevating movement between a contacting position in contact with the sheet and a distanced position distanced upward from the sheet, and a control portion that controls the elevating operation of the sheet loading portion and the elevating movement of the feeding member. When the feeding member at the contacting position moves to the distanced position, the feeding member is distanced upward from the sheet loaded on the sheet loading portion after the sheet loading portion starts a descending operation.

A sheet feeding apparatus includes: a storage part that stores a sheet, and a feeding part that has a feeding roller for feeding the sheet. The storage part and the feeding part are configured to be integrally inserted/withdrawn into/from an apparatus enclosure. The feeding roller is moved from a feeding position to a retracting position before the storage part and the feeding part are withdrawn from the enclosure.

A sheet feeding apparatus includes: a storage part that stores a sheet, and a feeding part that has a feeding roller for feeding the sheet. The storage part and the feeding part are configured to be integrally inserted/withdrawn into/from an apparatus enclosure. The feeding roller is moved from a feeding position to a retracting position before the storage part and the feeding part are withdrawn from the enclosure.

An index tab forming system sequentially forms index tabs to a plurality of sheets without replacing a blade die. The index tab forming system includes a rotary die cutter 5 on which a long blade die that can form an index tab at any position of the sheet in the conveyance direction is mounted. Furthermore, the index tab forming system includes a rotational speed calculation unit configured to calculate the rotational speed of a conveyance roller pair 37 based on the rotational position of a die cut roller 50, a sheet position detection signal provided by a sheet detection sensor 40, the number of times of sheet conveyance, and a shift distance between respective index tabs and a conveyance roller control unit configured to control the rotational speed of the conveyance roller pair 37 based on the calculated rotational speed.

An index tab forming system sequentially forms index tabs to a plurality of sheets without replacing a blade die. The index tab forming system includes a rotary die cutter 5 on which a long blade die that can form an index tab at any position of the sheet in the conveyance direction is mounted. Furthermore, the index tab forming system includes a rotational speed calculation unit configured to calculate the rotational speed of a conveyance roller pair 37 based on the rotational position of a die cut roller 50, a sheet position detection signal provided by a sheet detection sensor 40, the number of times of sheet conveyance, and a shift distance between respective index tabs and a conveyance roller control unit configured to control the rotational speed of the conveyance roller pair 37 based on the calculated rotational speed.