Sheet feeding device and image forming apparatus

A sheet feeding device comprising:

• a feeding roller pair configured to feed a sheet in a sheet feeding direction;
• a reference member provided downstream of said feeding roller pair with respect to the sheet feeding direction and extending along the sheet feeding direction;
• an obliquely feeding roller pair provided downstream of said feeding roller pair with respect to the sheet feeding direction and configured to feed the sheet in the sheet feeding direction while abutting a side end of the sheet against said reference member with respect to a sheet widthwise direction perpendicular to the sheet feeding direction;
• detecting means provided upstream of said obliquely feeding roller pair and configured to detect a position of the side end of the sheet with respect to the sheet widthwise direction;
• first changing means configured to change a state of said feeding roller pair between a nipping state in which the sheet is nipped and fed and a non-nipping state in which nipping of the sheet is released;
• second changing means configured to change a state of said obliquely feeding roller pair between the nipping state and the non-nipping state;
• and
• a controller configured to control said first changing means and said second changing means, wherein said controller causes said feeding roller pair to be in the nipping state and to start a first feeding operation for feeding the sheet toward said obliquely feeding roller and then, said controller causes said obliquely feeding roller pair to be in the nipping state and to start a second feeding operation for feeding the sheet for abutting the side end against said reference member,
• wherein said controller changes, after the first feeding operation is started and before the second feeding operation is started, a start timing of the second feeding operation on the basis of a detection result of the position of the side end of the sheet detected by said detecting means.