Patent ID: 11878886
Assignee: RICOH COMPANY, LTD.
Field: Handling (Mechanical engineering)
Classification: CPC B  G | IPC B

Claim 0:
1. A sheet feeding device comprising:
a support configured to detachably support a roll formed of a continuous sheet wound around a spool;
a rotation driver configured to rotate the spool supported by the support in a feeding direction and a winding direction of the continuous sheet;
a guide including:
a facing portion configured to face an outer circumferential surface of the roll; and
a guide portion extending downstream from the facing portion in the feeding direction;

a support shaft configured to swingably support the guide around a downstream end of the guide in the feeding direction, in a direction in which the facing portion contacts and separates from the roll;
a biasing member configured to press the guide in a direction in which the facing portion approaches the roll;
a leading end sensor configured to:
retractably project from the facing portion toward the roll to contact the roll; and
output a detection signal having a signal level in response to an amount of projection of the leading end sensor;

a roller supported by the facing portion, the roller configured to contact the outer circumferential surface of the roll at a different position from the leading end sensor in a circumferential direction of the roll;
an outer diameter sensor configured to detect an outer diameter of the roll; and
circuitry configured to:
control the rotation driver based on a signal change rate that is an amount of change in the signal level of the detection signal per unit time and a detection result of the outer diameter sensor;
cause the rotation driver to rotate the spool in the winding direction to determine a timing at which the signal change rate of the leading end sensor exceeds a change rate threshold as a passing time at which a leading end of the continuous sheet passes through the leading end sensor;
cause the rotation driver to rotate the spool by a rotation angle in the winding direction, from the passing time, to position the leading end at a feeding start position that is upstream from the leading end sensor and the roller in the winding direction and facing the guide portion;
cause the rotation driver to rotate the spool in the feeding direction to feed the continuous sheet from the feeding start position along the guide portion; and
change the change rate threshold based on the outer diameter of the roll detected by the outer diameter sensor.