An auto-adjusting separation mechanism, comprising: a bracket with at least one side arm, a sensor module arranged on the side arm, a rotary shaft arranged at the front end of the bracket; a separation roller set pivotally arranged on the rotary shaft, a sensor wheel arranged to couple with the sensor module, and a torque limiter arranged at the front end of the bracket; wherein, by monitoring the rotation of the sensor wheel with the sensor module, the separating force of the separation roller set is adjustable via a microcontrollers which is capable to adjust the transmission gear set.

An example print medium supplying apparatus includes a print medium transporting device to pick up a print medium loaded in a loading portion and transport the picked-up print medium, a print medium alignment portion to align a leading end of the transported print medium, a first sensor to sense the print medium that passes through a feed roller of the print medium transporting device, and a processor to, based on a measured value with respect to the print medium sensed by the first sensor and a multi-feeding determination reference value corresponding to a sheet of the print medium, detect multi-feeding of the print medium and process the detected multi-feeding by controlling the print medium transporting device and the print medium alignment portion.

An example print medium supplying apparatus includes a print medium transporting device to pick up a print medium loaded in a loading portion and transport the picked-up print medium, a print medium alignment portion to align a leading end of the transported print medium, a first sensor to sense the print medium that passes through a feed roller of the print medium transporting device, and a processor to, based on a measured value with respect to the print medium sensed by the first sensor and a multi-feeding determination reference value corresponding to a sheet of the print medium, detect multi-feeding of the print medium and process the detected multi-feeding by controlling the print medium transporting device and the print medium alignment portion.

A sheet feeding device includes a sheet feeding roller, a following roller, a rotational speed detection part, and a control part. The rotational speed detection part is configured to detect a rotational speed of the following roller. The control part is configured to accelerate a rotation of the sheet feeding roller and to adjust a sheet interval. The control part obtains a rotational rate of the following roller to the sheet feeding roller based on the rotational speed of the following roller, obtains an actual linear velocity of the sheet based on the rotational rate of the following roller and a theoretical linear velocity of the sheet after accelerating the rotation of the sheet feeding roller, and then adjusts the sheet interval based on the actual linear velocity of the sheet.

A sheet feeding device includes a sheet feeding roller, a following roller, a rotational speed detection part, and a control part. The rotational speed detection part is configured to detect a rotational speed of the following roller. The control part is configured to accelerate a rotation of the sheet feeding roller and to adjust a sheet interval. The control part obtains a rotational rate of the following roller to the sheet feeding roller based on the rotational speed of the following roller, obtains an actual linear velocity of the sheet based on the rotational rate of the following roller and a theoretical linear velocity of the sheet after accelerating the rotation of the sheet feeding roller, and then adjusts the sheet interval based on the actual linear velocity of the sheet.

The medium transporting device is arranged so as to face the feeder for feeding the medium in the transporting direction and the surface of the medium transported in the transporting direction, and detects the motion of the medium in the two-dimensional coordinate system including the first axis and the second axis. The two-dimensional sensor is provided in a state in which the first axis and the second axis are inclined with respect to the transporting direction.

A reading apparatus to convey a document set on a document tray and to read an image of the conveyed document includes a control unit and a determining unit. The control unit performs lifting control for lifting the document tray in a case where a first condition is satisfied and performs lowering control for lowering the document tray in a case where a second condition is satisfied. The determining unit determines whether a predetermined period elapses after the lifting control of previous time is started. The control unit does not perform the lowering control even if the second condition is satisfied in a case where the determining unit determines that the predetermined period does not elapse.

A reading apparatus to convey a document set on a document tray and to read an image of the conveyed document includes a control unit and a determining unit. The control unit performs lifting control for lifting the document tray in a case where a first condition is satisfied and performs lowering control for lowering the document tray in a case where a second condition is satisfied. The determining unit determines whether a predetermined period elapses after the lifting control of previous time is started. The control unit does not perform the lowering control even if the second condition is satisfied in a case where the determining unit determines that the predetermined period does not elapse.

A medium conveying apparatus includes a conveyance roller to convey a medium, an imaging device to image the medium, a DC motor to drive the conveyance roller, a processor to detect that a front end of the medium reaches between the conveyance roller and the imaging device, set a current limit value of the DC motor to a first limit value until the front end of the medium reaches between the conveyance roller and the imaging device, and change the current limit value to a second limit value larger than the first limit value after the front end of the medium has reached between the conveyance roller and the imaging device, and drive the conveyance roller by rotating the DC motor based on the second limit value when the imaging device performs imaging.

A document conveying device includes a document tray, a first rotary member, a first motor, a second rotary member, a second motor, a document feed sensor, and a controller. The controller counts a counted time from the time point that the first motor starts to rotate until the leading end of a document reaches the document feed sensor. When the time resulting from subtracting the counted time from a required sheet-to-sheet time interval is longer than the required speed change time, the controller performs deceleration and post-deceleration acceleration for the first motor. The required speed change time is the time required for speed change from the first rotation speed to the second rotation speed.