Image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorTomonori Kitan
Life of this patent
Estimating the term…
Abstract
An image forming apparatus adjusts a size of the loop of the sheet between the fixing unit and the transfer unit, according to a signal from a loop detection unit provided in a sheet conveyance path between a transfer unit and a fixing unit and configured to detect a loop of a sheet. The loop detection unit includes a detecting lever that is provided protrudably and retractably from and into the sheet conveyance path and abuts against the sheet, and a loop detection sensor that is turned on or off by the detecting lever. If the sheet is to be conveyed only by the transfer unit, the detecting lever moves to a retracting position from the sheet conveyance path.
Claims8
An image forming apparatus comprising:
- a transfer unit configured to transfer a toner image that has been formed by an image forming unit to a sheet;
- a fixing unit configured to fix the toner image that has been transferred by the transfer unit to the sheet;
- a sheet conveyance path, provided between the transfer unit and the fixing unit, guiding the sheet onto which toner image has been transferred by the transfer unit to the fixing unit;
- and
- a loop detection unit configured to detect a loop formed on the sheet in the sheet conveyance path,
- wherein a difference of sheet conveyance speeds between the transfer unit and the fixing unit is adjusted according to a signal from the loop detection unit, and the loop detection unit includes:
- a detecting member, provided protrudably and retractably in the sheet conveyance path, configured to movable by pressure received from the sheet to be conveyed;
- a detection sensor configured to detect the detecting member;
- a movement mechanism configured to move the detecting member protrudably and retractably into and from the sheet conveyance path;
- and
- a control unit configured to control an operation of the movement mechanism,
- wherein the control unit controls, until a leading edge of the sheet conveyed by the transfer unit reaches the fixing unit, the movement mechanism to move the detecting member to a retracting position from the sheet conveyance path.
An image forming apparatus comprising:
- a transfer unit configured to transfer a toner image that has been formed by an image forming unit to a sheet;
- a fixing unit configured to fix the toner image that has been transferred by the transfer unit to the sheet;
- a sheet conveyance path, provided between the transfer unit and the fixing unit, guiding the sheet onto which toner image has been transferred by the transfer unit to the fixing unit;
- and
- a loop detection unit configured to detect a loop formed on the sheet in the sheet conveyance path,
- wherein a difference of sheet conveyance speeds between the transfer unit and the fixing unit is adjusted according to a signal from the loop detection unit, and the loop detection unit includes:
- a detecting member, provided protrudably and retractably in the sheet conveyance path, configured to movable by pressure received from the sheet to be conveyed;
- a detection sensor configured to detect the detecting member;
- a movement mechanism configured to move the detecting member protrudably and retractably into and from the sheet conveyance path;
- and
- a control unit configured to control an operation of the movement mechanism,
- wherein the control unit controls, when a sheet is conveyed only by the fixing unit, the movement mechanism to move the detecting member to a retracting position from the sheet conveyance path.
Dependencies are inferred from the claim text.