Method and apparatus for forming image

An image forming apparatus that prints an image on a sheet with a recording head of an ink jet system, the image forming apparatus comprising:

• means for conveying the sheet in a predetermined direction;
• means for moving the recording head in a direction orthogonal to the conveying direction of the sheet;
• means for ejecting an ink from the recording head to the sheet to form an image on the sheet;
• means for stacking the sheet before printing and storing the sheet in a sheet stacking unit;
• means for conveying the sheet from the sheet stacking unit via a first conveying path below the recording head;
• means for conveying the sheet from the first conveying path to the recording head side via a second conveying path while reversing the sheet;
• means for conveying the sheet from the first conveying path to a temporary storing unit via a third conveying path in a state in which a front-to-rear direction of the sheet is maintained;
• means for conveying the sheet from the temporary storing unit to the recording head side via a fourth conveying path in a state in which the front-to-rear direction of the sheet is maintained;
• means for switching a conveying direction of the sheet fed from the first conveying path between the second conveying path and the third conveying path;
• and
• means for guiding the sheet fed from the second conveying path or the third conveying path to the fourth conveying path side.

An image forming method of printing an image on a sheet with a recording head of an ink jet system, the image forming method comprising:

• conveying the sheet in a predetermined direction;
• moving the recording head in a direction orthogonal to the conveying direction of the sheet;
• ejecting an ink from the recording head to the sheet to form an image on the sheet;
• stacking the sheet before printing and storing the sheet in a sheet stacking unit;
• conveying the sheet from the sheet stacking unit via a first conveying path below the recording head;
• conveying the sheet from the first conveying path to the recording head side via a second conveying path while reversing the sheet;
• conveying the sheet from the first conveying path to a temporary storing unit via a third conveying path in a state in which a front-to-rear direction of the sheet is maintained;
• conveying the sheet from the temporary storing unit to the recording head side via a fourth conveying path in a state in which the front-to-rear direction of the sheet is maintained;
• switching a conveying direction of the sheet fed from the first conveying path between the second conveying path and the third conveying path;
• and
• guiding the sheet fed from the second conveying path or the third conveying path to the fourth conveying path side.