Automatic original feeding apparatus

An image forming apparatus provided with an automatic original feeding apparatus for automatically feeding both first and second faces of an original to an image reading position for image reading, comprising:

• an image bearing member;
• reading means provided at the reading position;
• image forming means for forming, on said image bearing member, an image corresponding to an image of the original read by said reading means;
• a transfer unit for transferring the image formed on said image bearing member by said image forming means onto a sheet;
• original supporting means for supporting sheet originals thereon;
• separation feed means for separating the originals supported by said supporting means one by one to send out a thus separated original;
• a sheet feeding path for leading the original sent out from said separation feed means while inverting the original;
• conveying means for conveying the original led by said sheet path to the reading position and thereafter discharging the original therefrom in a direction opposite to the direction in which the original was led thereto;
• a sheet inverting path for leading the original discharged from the reading position to said conveying means, while inverting said original, from the same side of said apparatus as that through which the original has been discharged such that said discharged end thereof becomes a leading end;
• means for guiding the sheet to said transfer unit in such a manner that the image formed on said image bearing member by said image forming means corresponding to the first face of the original is transferred onto a first face of the sheet, and thereafter the image corresponding to the second face of the original is transferred onto a second face of the sheet;
• wherein the original is once transported through said sheet feeding path, said conveying means and said sheet inverting path without having been read, such that the original is led to the reading position and the first face thereof is read at the reading position;
• and thereafter, the original is inverted through said conveying means and said sheet inverting path such that the original is led to the reading position and the second face thereof is read at the reading position, without returning said original to said supporting means until both faces are presented for reading.

A sheet-original reading apparatus comprising:

• original supporting means for supporting sheet originals thereon;
• separation feed means for separating the originals supported by said supporting means one by one to send out a thus separated original;
• a first sheet path for leading the original sent out from said separation feed means while inverting the original;
• conveying means for conveying the original led by said first sheet path to a predetermined reading position and thereafter discharging the original therefrom in a direction opposite to the direction in which the original was led thereto;
• a second sheet path for effecting a first stitch-back of the original discharged from the predetermined reading position;
• and
• a third sheet path for effecting a second switch-back of the original led by said second sheet path after the first switch-back to lead the thus inverted original to said conveying means,
• wherein the original is once transported through said first sheet path, said conveying means, said second sheet path and said third sheet path without having been read, such that the original is led to the predetermined reading position and a first face of the original is then read at the predetermined reading position;
• and thereafter, the original is inverted through said conveying means, said second sheet path and said third sheet path such that the original is led to the predetermined reading position, and a second face of the original is read at the predetermined reading position.

An image forming apparatus provided with an automatic original feeding apparatus for automatically feeding both first and second faces of an original to a predetermined image reading position for image reading, comprising:

• a image bearing member;
• reading means provided at the predetermined image reading position;
• image forming means for forming, on said image bearing member, am image corresponding to an image of the original read by said reading means;
• a transfer unit for transferring the image formed on said image bearing member by said image forming means onto a sheet;
• original supporting means for supporting sheet originals thereon;
• separation feed means for separating the originals supported by said supporting means one by one to send out a thus separated original;
• a first sheet path for leading the original sent out from said separation feed means while inverting the original;
• conveying means for conveying the original led by said first sheet path to the reading position and thereafter discharging the original therefrom in a direction opposite to the direction in which the original was led thereto;
• a second sheet path for effecting a first switch-back of the original discharged from the reading position;
• a third sheet path for effecting a second switch-back of the original led by said second sheet path after the first switch-back to lead the thus inverted original to said coveying means;
• and
• means for guiding the sheet to said transfer unit in such a manner that the image formed on said image bearing member by said image forming means corresponding to the first face of the original is transferred onto a first face of the sheet, and thereafter the image corresponding to the second face of the original is transferred onto a second face of the sheet,
• wherein the original is once transported through said first sheet path, said conveying means, said second sheet path and said third sheet path without having been read, such that the original is led to the reading position, and a first face thereof is read at the reading position;
• and thereafter, the original is inverted through said conveying means, said second sheet path and said third sheet path such that the original is led to the reading position and a second face thereof is read at the reading position.