Patent ID: 7845626
Filing Date: 2010-12-07
Classification: B26D,B26F,B65H,G03G,Y10T

Abstract:
1. A sheet processing apparatus comprising: a first detecting unit including a first sensor and a second sensor arranged at a predetermined spacing from each other on a line orthogonal to a conveying path through which a sheet is conveyed; a hole punching section provided downstream from the first detecting unit and at a predetermined distance from the first detecting unit, and arranged orthogonally to the conveying path of the sheet, and configured to perform punching processing to the sheet conveyed thereto; a skew detecting unit configured to detect a quantity of skew of the sheet in accordance with a difference between time when a forward edge or a rear edge of the sheet passing through the conveying path passes the first sensor and time when the forward edge or rear edge passes the second sensor; a position calculating unit configured to calculate position information in a conveying direction of the sheet with respect to the hole punching section, the position calculating unit calculates a time (L/V+X/2) taken for the sheet to reach the hole punching section from the first detecting unit, where (X) represents a time difference between time when the forward edge or rear edge of the sheet passes the first sensor and time when the forward edge or rear edge of the sheet passes the second sensor, (L) represents a distance between the first detecting unit and the hole punching section, and (V) represents a conveying speed of the sheet in accordance with information of timing when the first sensor and the second sensor detect the passage of the sheet edge, and the conveying speed of the sheet; an attitude control unit configured to carry out skew correction by changing tilt angle of the hole punching section in accordance with the quantity of skew detected by the skew detecting unit; and a control unit configured to control punching processing to the sheet in accordance with the position information of the sheet calculated by the position calculating unit.