Copying machine for copying documents in two-in-one mode

A copying machine having a two-in-one copying mode in which two document sheets are fed on a glass platen in series with respect to a document conveying direction and copied onto one copy sheet by one-time exposure scanning, the copying machine comprising:

• a document feeder means for feeding document sheets toward the glass platen one by one to stop the document sheets at a first-out position which is situated on an upstream side of the document conveying direction;
• a first conveying means for conveying the document sheets fed by the document feeder means onto the glass platen;
• a second conveying means for conveying the document sheets conveyed by the first conveying means along the glass platen until the rear end of the document sheets reach a predetermined switch-back position, conveying the document sheets in the opposite direction to retreat a predetermined distance, conveying a first of the document sheets as well as a succeeding second document sheet stopped at the first-out position such that the front end of the first document sheet situated on a downstream side of the document conveying direction may be aligned with an exposure reference, and discharging the first and second document sheets to the downstream side of the document conveying direction after exposure;
• and
• a third conveying means for conveying the document sheets discharged by the second conveying means from the glass platen to a discharge section;
• whereby the document conveying length (d3) from the exposure reference to the third conveying means is longer than the sum (d4+.DELTA.dp) of the document conveying length (d4) from the first-out position to the switch-back position and the difference length (.DELTA.dp) of the document conveying direction between a document sheet having a longest length and a document sheet having a shortest length among document sheets to be handled in the two-in-one mode.