Patent ID: 9567174
Date: 2017-02-14
CPC Classifications: B65H,H04N

Claim:
1. A sheet feeder for feeding a sheet toward a predetermined processing position, comprising: a sheet supply tray for placing the sheet; a delivery roller adapted to contact the sheet on the sheet supply tray to deliver the sheet; a first detection sensor disposed upstream of the delivery roller and adapted to detect the sheet while the sheet is placed on the sheet supply tray; a second detection sensor disposed downstream of the delivery roller and adapted to detect a leading end portion of the sheet while the sheet is placed on the sheet supply tray; a stopper disposed adjacent to the sheet supply tray and adapted to abut against the leading end portion of the sheet to regulate the leading end portion of the sheet while the sheet is placed on the sheet supply tray before the delivery roller is actuated; and a controller activating the delivery roller in a state where the first detection sensor detects the sheet and the second detection sensor does not detect the leading end portion of the sheet while the sheet is placed on the sheet supply tray, wherein the second detection sensor detects the leading end portion of the sheet while the leading end portion of the sheet is located adjacent to the stopper, the first detection sensor is a size sensor adapted to detect a size of the sheet while the sheet is placed on the sheet supply tray, the second detection sensor is a set sensor adapted to detect the leading end portion of the sheet while the sheet placed is on the sheet supply tray, the first detection sensor includes a small-size sensor adapted to detect a sheet having a predetermined size and a large-size sensor adapted to detect a sheet having a size larger than the predetermined size, the first detection sensor is structured so that when only the small-size sensor detects the sheet, the size of the sheet is determined to be the predetermined size, and when the small-size sensor and the large-size sensor detect the sheet, the size of the document is determined to be larger than the predetermined size, and when the second detection sensor detects the leading end portion of the sheet and the first detection sensor does not detect the sheet while the sheet is placed on the sheet supply tray, the controller controls the delivery roller to contact and deliver the sheet toward the predetermined processing position.