Image forming apparatus including a sheet refeeding unit

An electrophotographic image forming apparatus comprising:

• a frame;
• image forming means for forming an image on a sheet, the image forming means being fixed on the frame;
• a refeeding unit comprising an intermediate tray for temporarily containing image-formed sheets as a pile thereon and refeeding means for feeding the sheets from the intermediate tray toward the image forming means;
• adjusting means for adjusting a position of the sheets to be fed by said refeeding unit in a direction perpendicular to a sheet transporting direction by shifting said refeeding unit;
• locking means which can be engaged with the frame to regulate the position of the refeeding unit in the direction perpendicular to the sheet transporting direction, wherein the refeeding unit can be pushed into and pulled out of the frame in the direction perpendicular to the sheet transporting direction;
• and
• urging means for urging the refeeding unit elastically in the direction of pulling the refeeding unit out of the frame while the locking means is engaged with the frame.

An electrophotographic image forming apparatus comprising:

• an intermediate tray for temporarily containing image-formed sheets as a substantially horizontal pile thereon;
• transporting means for transporting the image-formed sheets to the intermediate tray, the transporting means being provided adjacent to an upper portion of the intermediate tray;
• refeeding means for feeding the sheets contained on the intermediate tray one by one from a most bottom sheet to subject the sheets to an image forming operation;
• an front end aligning member for aligning front ends, in a view of the refeeding direction, of the sheets on the intermediate tray;
• a rear end aligning member for aligning rear ends, in a view of the refeeding direction, of the sheets on the intermediate tray;
• a sheet pressing member for pressing each sheet which is transported to the intermediate tray by the transporting means toward the refeeding means;
• and
• controlling means for starting an operation of the pressing member when the rear end of each sheet passes through the transporting means so that the sheet will be aligned with sheets already contained on the intermediate tray.

An electrophotographic image forming apparatus comprising:

• an intermediate tray for temporarily containing image-formed sheets as a substantially horizontal pile thereon;
• refeeding means for feeding the sheets contained on the intermediate tray one by one from a most bottom sheet to subject the sheets to an image forming operation;
• a sheet pressing member for pressing each sheet transported to the intermediate tray toward the refeeding means, the sheet pressing member being movable between a retreating position and a pressing position where the sheet pressing member can supply a suitable pressure for sheet feeding;
• and
• controlling means for controlling the sheet pressing member to move to the retreating position when each sheet is coming to the intermediate tray, to move to the pressing position when each sheet is refed from the intermediate tray and to move to an intermediate position between the retreating position and the pressing position when a refeeding of each sheet is finished.

An electrophotographic image forming apparatus comprising:

• an intermediate tray for temporarily containing image-formed sheets as a substantially horizontal pile thereon;
• refeeding means for feeding the sheets contained on the intermediate tray one by one from a most bottom sheet to subject the sheets to an image forming operation;
• separating means for separating the most bottom sheet from the other sheets when the refeeding means starts refeeding;
• a separating plate for positioning the most bottom sheet to be closer to the separating means than the other sheets;
• a rear end aligning member for aligning rear ends, in a view of a refeeding direction, of the sheets on the intermediate tray;
• and
• driving means for moving the rear end aligning member in the refeeding direction so that front ends, in a view of the refeeding direction, of the sheets on the intermediate tray will come in contact with the separating plate.

An electrophotographic image forming apparatus comprising:

• an intermediate tray for temporarily containing image-formed sheets as a substantially horizontal pile thereon;
• transporting means for transporting the image-formed sheets to the intermediate tray;
• refeeding means for feeding the sheets contained on the intermediate tray one by one to subject the sheets to an image forming operation;
• a side aligning member for aligning both sides, in a view of the refeeding direction, of the sheets on the intermediate tray, the side aligning member being movable in a direction perpendicular to the refeeding direction to align the sides of the sheets;
• and
• a guiding member for guiding each sheet to the intermediate tray, the guiding member being set above the intermediate tray and configured to form a space between the guiding member and the intermediate tray, said space being narrowest at the center of the guiding member in the refeeding direction and becoming wider gradually in the refeeding direction to decrease friction between the guiding member and the leading end of the sheet.

An electrophotographic image forming apparatus comprising:

• an intermediate tray for temporarily containing image-formed sheets as a substantially horizontal pile thereon;
• transporting means for transporting the image-formed sheets to the intermediate tray;
• refeeding means for feeding the sheets contained on the intermediate tray one by one to subject the sheets to an image forming operation;
• a sheet pressing member for pressing each sheet transported to the intermediate tray, the sheet pressing member being movable between a retreating position where the sheet pressing plate does not interrupt the sheet transportation to the intermediate tray and a pressing position where the sheet pressing plate presses the sheet;
• position detecting means for detecting a position of the sheet pressing member;
• driving means for moving the sheet pressing member from the retreating position to the pressing position every time a rear end of a sheet passes through the transporting means;
• and
• checking means for, when the sheet pressing means is supposed to reach the pressing position, checking whether the position detecting means indicates that the sheet pressing means is in the pressing position.