Paper conveying mechanism in image forming apparatus

A paper conveying mechanism in an image forming apparatus, comprising:

• an image forming body section of a front operating type provided with a forward conveying path for conveying a discharged sheet of recording paper having an image formed thereon toward a direction of front and rear sides of the image forming apparatus;
• after-treatment means for after-treating the sheet of recording paper and arranged in parallel to a side portion of the image forming body section;
• a perpendicular conveying path connected with the forward conveying path for conveying the sheet of recording paper discharged from the forward conveying path toward a direction approximately perpendicular to the forward conveying path in a horizontal face of the sheet of recorded paper, thereby to feed the sheet of recording paper to said after-treatment means;
• first feeding means for feeding the sheet of recording paper in said forward conveying path;
• second feeding means for feeding the sheet of recording paper in said perpendicular conveying path;
• and
• a switching means connected with both of said first feeding means and said second feeding means for switching selectively an operation and a stop of feeding of the sheet of recording paper by said first feeding means or said second feeding means,
• said first feeding means including means for selecting either a paper conveying speed V.sub.1 equal to said image forming process speed or a paper conveying speed V.sub.2 set to be higher than said image forming process speed by providing a constant relation therebetween.

A paper conveying mechanism in an image forming apparatus, comprising:

• an image forming body section of a front operating type provided with a forward conveying path for conveying a discharged sheet of recording paper toward a direction of front and rear sides of the image forming apparatus at a predetermined feed speed, said sheet of recording paper having an image thereon formed at a predetermined image forming process speed;
• after-treatment means for after-treating the sheet of recording paper and arranged in parallel to a side portion of the image forming body section;
• a perpendicular conveying path connected with the forward conveying path for conveying the sheet of recording paper discharged from said forward conveying path toward a direction approximately perpendicular to the forward conveying path in a horizontal face of the sheet of recording paper, thereby to feed the sheet of recording paper to said after-treatment means;
• first feeding means for feeding the sheet of recording paper in said forward conveying path;
• means for selecting either a paper conveying speed V.sub.1 equal to said image forming process speed or a paper-conveying speed V.sub.2 set to be higher than said image forming process speed by providing a constant relation therebetween, said selecting means being disposed in the first feeding means in the forward conveying path;
• and
• means for setting the paper conveying speed by using, as a reference, the sheet of recording paper having a largest value with respect to a difference (h-i) between a width h of the sheet of recording paper with respect to a conveying direction thereof and a distance i between sheets of recording paper, said setting means being disposed in the first feeding means in the forward conveying path.

A paper conveying mechanism in an image forming apparatus, comprising:

• a conveying-circulating path for conveying and circulating a sheet of recording paper in a conveying direction set from a front side to a rear side with respect to an operation face of a copying machine;
• discharging ports for discharging the sheet of recording paper and respectively disposed on an upper side of said copying machine in said conveying-circulating path and on one side of the copying machine corresponding to a direction perpendicular to said conveying direction in a horizontal face of the sheet of recording paper;
• a first switch back conveying path for a small paper size located just behind the fixing device on a downstream side thereof in said conveying direction in said conveying-circulating path, said first switch back conveying path being separated from said discharging port on the upper side of the copying machine and setting a conveying path toward a paper resupplying device for a two-sided copy;
• a second switch back conveying path for a large paper size located on a downstream side of the first switch back conveying path in said conveying-circulating path, said second switch back conveying path being branched from a discharging path toward the discharging port on the upper side of the copying machine and setting a conveying path toward said paper resupplying device for a two-sided copy;
• a synthesis conveying path for a synthetic copy branched from the discharging path toward the discharging port on the upper side of the copying machine and setting a conveying path toward said paper resupplying device for a two-sided copy;
• and
• a perpendicular conveying path branched from the second switch back conveying path and synthesis conveying path, for changing the conveying direction of the sheet of recording paper in a direction perpendicular to said conveying direction in a position different from that of the paper resupplying device for a two-sided copy in a horizontal face of the sheet of recording paper.

A paper conveying mechanism in an image forming apparatus, comprising:

• a conveying circulating path for conveying and circulating a sheet of recording paper in a conveying direction set from a front side to a rear side with respect to an operation face of a copying machine;
• discharging ports for discharging the sheet of recording paper and respectively disposed on an upper side of said copying machine in said conveying-circulating path and on one side of the copying machine corresponding to a direction perpendicular to said conveying direction in a horizontal face of the sheet of recording paper to said conveying direction;
• a first switch back conveying path for a small paper size located just behind the fixing device on a downstream side thereof in said conveying direction in said conveying-circulating path, said switch back conveying path for a small paper size being separated from said discharging port on the upper side of the copying machine and setting a conveying path toward a paper resupplying device for a two-sided copy;
• a second switch back conveying path for a larger paper size located on a downstream side of the first switch back conveying path in said conveying-circulating path, said second switch back conveying path being branched from a discharging path toward the discharging port on the upper side of the copying machine and setting a conveying path toward said paper resupplying device for a two-sided copy;
• a synthesis conveying path for a synthetic copy branched from the discharging path toward the discharging port on the upper side of the copying machine and setting a conveying path toward said paper resupplying device for a two-sided copy;
• and
• a perpendicular conveying path branched from the second switching back conveying path and synthesis conveying path, for changing the conveying direction of the sheet of recording paper in a direction perpendicular to said conveying direction in a position different from that of the paper resupplying device for a two-sided copy in a horizontal face of the sheet of recording paper,
• a conveying speed V.sub.1 of the sheet of recording paper at the time of an image transfer processing on a photosensitive body for forming an image thereon in the conveying path from the front side to the rear side with respect to said operation face is set to be less than a conveying speed V.sub.2 of the sheet of recording paper at the time of a copying processing except for the image transfer processing.