Sheet conveyance apparatus and image forming apparatus

An image forming apparatus comprising:

• a transmission unit configured to transmit an ultrasonic wave toward a sheet being conveyed;
• a reception unit arranged opposite to the transmission unit across the sheet and configured to receive the ultrasonic wave;
• a conveyance guide unit configured to form a conveyance path through which the sheet being conveyed between the transmission unit and the reception unit passes;
• an image forming unit configured to form an image on the sheet guided by the conveyance guide unit;
• an acquisition unit configured to acquire sheet information about the sheet to be conveyed;
• a change unit configured to change a distance of the conveyance path in a thickness direction of the sheet;
• and
• a control unit configured to control the change unit to change the distance of the conveyance path according to the acquired sheet information.

A sheet conveyance apparatus comprising:

• a double sheet feed detector, including a transmitter and a receiver arranged opposite to the transmitter across the sheet, configured to detect whether double sheet feed occurs based on an output from the receiver;
• a conveyance guide unit configured to form a conveyance path through which the sheet being conveyed between the transmitter and the receiver passes;
• an acquisition unit configured to acquire grammage information about grammage of the sheet to be conveyed;
• a change unit configured to change a distance of the conveyance path in a thickness direction of the sheet;
• and
• a control unit configured to control the change unit to set the distance of the conveyance path in the thickness direction of the sheet according to the grammage information acquired by the acquisition unit,
• wherein, in a case where the grammage information indicates that grammage of the sheet is first grammage, the control unit controls the change unit to set the distance of the conveyance path in such a manner that the distance of the conveyance path in the thickness direction of the sheet becomes larger than in a case where the grammage information indicates that grammage of the sheet is second grammage which is smaller than the first grammage, and
• wherein the double sheet feed detector detects whether double sheet feed occurs in a state where the distance of the conveyance path in the thickness direction of the sheet is changed by the change unit.

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• a double sheet feed detector, including a transmitter and a receiver arranged opposite to the transmitter across the sheet, configured to detect whether double sheet feed occurs based on an output from the receiver;
• a conveyance guide unit configured to form a conveyance path through which the sheet being conveyed between the transmitter and the receiver passes;
• an acquisition unit configured to acquire grammage information about grammage of the sheet to be conveyed;
• a change unit configured to change a distance of the conveyance path in a thickness direction of the sheet;
• and
• a control unit configured to control the change unit to set the distance of the conveyance path in the thickness direction of the sheet according to the grammage information acquired by the acquisition unit,
• wherein, in a case where the grammage information indicates that grammage of the sheet is first grammage, the control unit controls the change unit to set the distance of the conveyance path in such a manner that the distance of the conveyance path in the thickness direction of the sheet becomes larger than in a case where the grammage information indicates that grammage of the sheet is second grammage which is smaller than the first grammage, and
• wherein the double sheet feed detector detects whether double sheet feed occurs in a state where the distance of the conveyance path in the thickness direction of the sheet is changed by the change unit.