Double-sided image forming apparatus and method

A double-sided image forming apparatus which forms a first image supported by a first image supporting medium and a second image supported by a second image supporting medium on both sides of each of a plurality of copy sheets by reading the first image and the second image from a plurality of documents sequentially, comprising:

• a first unit performing developing of the first image and the second image on the first image supporting medium;
• a second unit performing transferring of the developed second image from the first image supporting medium to the second image supporting medium;
• a third unit performing continuously double-sided image formation for second and subsequent copy sheets among the plurality of copy sheets in which the developed first image of the first image supporting medium and the developed second image of the second image supporting medium are transferred to both sides of each copy sheet after a start of the reading of the second image of a following copy sheet;
• and
• a fourth unit performing, only for a first copy sheet, the double-sided image formation earlier than the start of the reading of the second image of a following copy sheet.

A double-sided image forming method which forms a first image supported by a first image supporting medium and a second image supported by a second image supporting medium on both sides of a copy sheet simultaneously in an image forming apparatus, the method comprising:

• developing the first image and the second image on the first image supporting medium;
• transferring the developed second image to the second image supporting medium;
• and
• controlling the developing of the second image on the first image supporting medium to be performed earlier than the developing of the first image on the first image supporting medium.

A double-sided image forming method which forms a first image supported by a first image supporting medium and a second image supported by a second image supporting medium on both sides of each of a plurality of copy sheets in an image forming apparatus by reading the first image and the second image from a plurality of documents sequentially, the method comprising:

• developing the first image and the second image on the first image supporting medium;
• transferring the developed second image from the first image supporting medium to the second image supporting medium;
• performing continuously double-sided image formation for second and subsequent copy sheets among the plurality of copy sheets in which the developed first image of the first image supporting medium and the developed second image of the second image supporting medium are transferred to both sides of each copy sheet after a start of the reading of the second image of a following copy sheet;
• and
• performing, only for a first copy sheet, the double-sided image formation earlier than the start of the reading of the second image of a following copy sheet.