Sheet conveyance apparatus, image reading apparatus and image forming apparatus

An image reading apparatus comprising:

• a supporting portion configured to support a sheet;
• a detection unit configured to detect a sheet supported on the supporting portion;
• a feeding unit disposed above the supporting portion and configured to feed a sheet supported on the supporting portion;
• a lifting unit configured to lift and lower the supporting portion between a first position at which a sheet supported on the supporting portion abuts on the feeding unit and a second position below the first position;
• a control unit configured to control lifting and lowering of the supporting portion by the lifting unit;
• and
• a reading portion configured to read image information from a sheet fed by the feeding unit,
• wherein the control unit is configured to cause the lifting unit to move the supporting portion from the second position to a third position between the first position and the second position based on a detection of a sheet by the detection unit and to move the supporting portion from the third position to the first position based on an instruction to start sheet feeding.

An image forming apparatus comprising:

• a supporting portion configured to support a sheet;
• a detection unit configured to detect a sheet supported on the supporting portion;
• a feeding unit disposed above the supporting portion and configured to feed a sheet supported on the supporting portion;
• a lifting unit configured to lift and lower the supporting portion between a first position at which a sheet supported on the supporting portion abuts on the feeding unit and a second position below the first position;
• a control unit configured to control lifting and lowering of the supporting portion by the lifting unit;
• a reading portion configured to read image information from a sheet fed by the feeding unit;
• and
• an image forming portion configured to form an image on a recording material based on the image information read by the reading portion,
• wherein the control unit is configured to cause the lifting unit to move the supporting portion from the second position to a third position between the first position and the second position based on a detection of a sheet by the detection unit and to move the supporting portion from the third position to the first position based on an instruction to start sheet feeding.