Sheet feeding apparatus and image forming apparatus

A sheet feeding apparatus comprising:

• a feed roller configured to feed a sheet in a feeding direction;
• a supporting portion configured to support the sheet to be fed by the feed roller;
• a size detection portion capable of detecting a length in the feeding direction of the sheet supported on the supporting portion;
• a drive unit configured to drive the feed roller;
• a separation roller driven by the drive unit through a torque limiter in a direction against the feeding direction so that the sheet is separated from another sheet at a separation nip portion formed between the feed roller and the separation roller;
• a pair of conveyance rollers configured to convey the sheet at a conveyance nip portion formed between the pair of conveyance rollers, the conveyance nip portion being disposed downstream of the separation nip portion in the feeding direction;
• and
• a control portion configured to execute a first control mode in which a first sheet is conveyed and a second control mode in which a second sheet having a lower basis weight than that of the first sheet is conveyed, the control portion being configured to stop the drive unit with the sheet nipped at both nips of the separation nip portion and the conveyance nip portion in each of the first and second control modes, a timing when the drive unit is stopped by the control portion in the second control mode being earlier than a timing when the drive unit is stopped by the control portion in the first control mode,
• wherein the control portion is configured to change the timing when the drive unit is stopped in the first control mode based on the length in the feeding direction of the sheet detected by the size detection portion.

A sheet feeding apparatus comprising:

• a feed roller configured to feed a sheet in a feeding direction;
• a pickup roller configured to come into contact with the sheet at a contact position to convey the sheet in the feeding direction toward the feed roller;
• a drive unit configured to drive the feed roller;
• a separation roller driven by the drive unit through a torque limiter in a direction against the feeding direction so that the sheet is separated from another sheet at a separation nip portion formed between the feed roller and the separation roller;
• a pair of conveyance rollers configured to convey the sheet at a conveyance nip portion formed between the pair of conveyance rollers, the conveyance nip portion being disposed downstream of the separation nip portion in the feeding direction;
• a pair of registration rollers disposed downstream of the conveyance nip portion in the feeding direction and configured to nip and convey the sheet received from the pair of conveyance rollers;
• and
• a control portion configured to execute a first control mode in which a first sheet is conveyed and a second control mode in which a second sheet having a lower basis weight than that of the first sheet is conveyed, the control portion being configured to stop the drive unit with the sheet nipped at both nips of the separation nip portion and the conveyance nip portion in each of the first and second control modes, a timing when the drive unit is stopped by the control portion in the second control mode being earlier than a timing when the drive unit is stopped by the control portion in the first control mode,
• wherein in a case where the first sheet is longer than an interval between the pickup roller and the pair of registration rollers, the control portion stops the drive unit after a leading edge of the first sheet reaches the pair of registration rollers in the first control mode, and stops the drive unit before the leading edge of the second sheet reaches the pair of registration rollers in the second control mode.