Medium feeding device and medium processing device including the same

A medium feeding device, comprising:

• a container member that accommodates sheet media;
• a discharging member located further than the media accommodated in the container member in a discharging direction in which the media are discharged, to discharge the media one by one;
• a hand-over member disposed above the container member to suck the media accommodated in the container member with air and pass the media to the discharging member;
• a floating device disposed on a side of the media accommodated in the container member to blow air to an upper area of a side end surface of the media to float the media while an upper portion of the media is separated;
• a detector that detects a separation state of the medium floated by the floating device;
• and
• a controller that controls a medium-feeding operation including a pre-feeding blowing operation and a during-feeding blowing operation, the pre-feeding blowing operation serving as an air blowing operation performed by the floating device before the medium is fed, and the during-feeding blowing operation serving as an air blowing operation performed by the floating device from a start of feeding the medium to an end of feeding the medium,
• wherein after the media are feedably accommodated in the container member and while performing the pre-feeding blowing operation and the during-feeding blowing operation, the controller performs detection with the detector, and on condition that a result of the detection fails to satisfy a preset target range, the controller changes a parameter for the medium-feeding operation including at least one of the pre-feeding blowing operation or the during-feeding blowing operation,
• wherein the detector detects a thickness of each of the media floating within a detection area,
• wherein the target range corresponds to no medium having a thickness larger than a predetermined range,
• wherein the target range is set variable with information of a type of the media,
• wherein the controller counts a number of times the controller changes the parameter, and
• wherein if the result of the detection fails to satisfy the preset target range and the number of times is less than a predetermined number of times, the controller changes the parameter for the medium-feeding operation including at least the pre-feeding blowing operation or the during-feeding blowing operation, and
• if the result of the detection fails to satisfy the preset target range and the number of times is equal to or more than the predetermined number of times, the predetermined number of times being more than one, the controller controls the medium feeding device so as to change an operation mode thereof.