| US 7,578,498 B2 | ||
| Sheet processing apparatus and sheet processing method | ||
| Ken Iguchi, Sunto-gun (Japan); Hiroyuki Tsuchihashi, Mishima (Japan); and Tetsuhiro Morita, Mishima (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan); and Toshiba Tec Kabushiki Kaisha, Tokyo (Japan) | ||
| Filed on Mar. 07, 2008, as Appl. No. 12/44,077. | ||
| Claims priority of provisional application 60/943596, filed on Jun. 13, 2007. | ||
| Claims priority of provisional application 60/944935, filed on Jun. 19, 2007. | ||
| Claims priority of provisional application 60/944936, filed on Jun. 19, 2007. | ||
| Claims priority of provisional application 60/944943, filed on Jun. 19, 2007. | ||
| Prior Publication US 2008/0309006 A1, Dec. 18, 2008 | ||
| Int. Cl. B65H 39/00 (2006.01) | ||
| U.S. Cl. 270—58.07 | 11 Claims |
| 8. A sheet processing method comprising:
arranging a hole punching section configured to perform punching processing to a sheet that is conveyed, orthogonally to a
conveying path of the sheet and having a tilt angle changeable with respect to the conveying direction of the sheet;
detecting a quantity of skew at a forward edge and a quantity of skew at a rear edge of the sheet conveyed along the conveying
path, upstream from the hole punching section;
changing the tilt angle of the hole punching section in accordance with each of the quantity of skew at the forward edge and
the quantity of skew at the rear edge, carrying out skew correction at the forward edge within a first correction range w1, and enabling skew correction at the rear edge within a second correction range w2 (where w1>w2≧w1/2) that is narrower than the first correction range;
carrying out skew correction at the forward edge in accordance with the quantity of skew at the forward edge and carrying
out skew correction at the rear edge in accordance with the quantity of skew at the rear edge, in the case where the detected
quantity of skew at the forward edge is a tilt angle within the second correction range w2; and
carrying out skew correction at the forward edge by tilting the hole punching section within the second correction range,
in the case where the detected quantity of skew at the forward edge is a tilt angle exceeding the second correction range
w2, and then carrying out skew correction at the forward edge by tilting the hole punching section in accordance with a difference
between the quantity of skew at the forward edge after the correction and the quantity of skew at the rear edge.
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