Apparatus for processing sheets

1. A sheet processing apparatus, which is arranged in a space between an image reading section for reading an image and an image formation section for forming an image on a sheet, the image formation section being arranged under the image reading section and the space, the sheet processing apparatus allocating a sheet transported in a predetermined transport direction to collect in a first collection tray or a second collection tray, comprising:

a carry-in path adapted to guide a sheet from a carry-in entrance;

a relay roller provided in the carry-in path to relay and transport the sheet;

a first transport path, positioned on a downstream side of the relay roller, including a carry-in roller to transport the sheet from the carry-in path to the first collection tray; and

a second transport path, branched off from the carry-in path, including a branch roller to transport the transported sheet to the second collection tray,

wherein the relay roller shifts the sheet in a direction crossing the transport direction, and a shift by the relay roller is performed for a period during which a front end of the sheet enters the first transport path or the second transport path, and arrives at the carry-in roller or the branch roller.

2. The sheet processing apparatus according to claim 1 , wherein in a position branched off from the carry-in path, an allocating member for allocating the sheet to one of the first transport path and the second transport path is disposed immediately after the relay roller, and the shift of the sheet by the relay roller is started, after the front end of the sheet passes through the allocating member.

3. The sheet processing apparatus according to claim 2 , wherein the relay roller includes a receiving position for receiving a sheet transported from the carry-in entrance, shifts the sheet to a shift position on a front side or a rear side in a crossing direction from the receiving position after receiving the sheet, and returns to the receiving position after the sheet subjected to the shift passes through the relay roller.

4. The sheet processing apparatus according to claim 3 , wherein the relay roller performs the shift of the sheet, in transporting the sheet shorter than a length from the carry-in entrance to the carry-in roller or the branch roller.

5. The sheet processing apparatus according to claim 4 , wherein a position in which the shift of the sheet by the relay roller is completed is substantially the same position in sheets with different sheet lengths.

6. The sheet processing apparatus according to claim 4 , wherein the carry-in path guides a sheet fed to the first transport path or the second transport path, and further guides a switchback sheet that arrives at the second transport path from the carry-in entrance and that is then fed backward to return to the carry-in entrance side, and the relay roller shifts the sheet fed to the first transport path or the second transport path.

7. The sheet processing apparatus according to claim 4 , further comprising:

a processing tray adapted to temporarily place a transported sheet and discharge to the first collection tray, between the carry-in roller in the first transport path and the first collection tray; and

a position shift member adapted to vary a collection position of the sheet in the processing tray before discharging to the first collection tray,

wherein in a case of shifting a sheet with a length longer than a length to transport from the carry-in entrance to the carry-in roller or the branch roller, the sheet is shifted by the position shift member provided in the processing tray.

8. The sheet processing apparatus according to claim 7 , wherein the shift member is a pair of alignment plates that performs reciprocating motion in the processing tray in the direction crossing the transport direction of the sheet.

9. The sheet processing apparatus according to claim 8 , wherein a bind unit for binding sheets as a bunch is disposed in an end of the processing tray, on the side opposite to a discharge direction to the first collection tray.

10. A sheet processing apparatus, which is arranged in a space between an image reading section for reading an image and an image formation section for forming an image on a sheet, the image formation section being arranged under the image reading section and the space, the sheet processing apparatus collecting a sheet transported in a predetermined transport direction, comprising:

a carry-in path adapted to guide a sheet from a carry-in entrance;

a relay roller provided in the carry-in path to relay and capable of shifting the sheet in a direction crossing the transport direction;

a transport path positioned on a downstream side of the relay roller and transporting the sheet from the carry-in path in a direction downstream of the transport direction;

a collection tray collecting a sheet transported in the transport direction; and

an alignment section positioned on the collection tray and aligning the sheet in a sheet width direction orthogonal to the sheet transport direction,

wherein the relay roller shifts the sheet in the direction crossing the transport direction, and a shift by the relay roller is performed by arriving at the carry-in roller or the branch roller, and

the alignment section is located in an area overlapping with the relay roller in a height direction orthogonal to the transport direction.

11. The sheet processing apparatus according to claim 10 , wherein the transport path extends substantially in a horizontal direction.

12. The sheet processing apparatus according to claim 11 , wherein the transport path is arranged substantially in the sheet transport direction.

13. A sheet processing apparatus, comprising:

a carry-in path adapted to guide a sheet from a carry-in entrance;

a relay roller provided in the carry-in path to relay and capable of shifting the sheet in a direction crossing the transport direction;

a transport path arranged substantially in a horizontal direction, positioned on a downstream side of the relay roller, and transporting the sheet from the carry-in path in a direction downstream of the transport direction;

a collection tray collecting a sheet transported in the transport direction; and

an alignment section positioned on the collection tray and aligning the sheet in a sheet width direction orthogonal to the sheet transport direction,

wherein the relay roller shifts the sheet in the direction crossing the transport direction, and a shift by the relay roller is performed by arriving at the carry-in roller or the branch roller, and

the alignment section is located in an area overlapping with the relay roller in a height direction orthogonal to the transport direction.