Sheet processing apparatus and sheet processing method

摘要

A sheet processing apparatus includes 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, and a hole punching section provided downstream at a predetermined distance from the first detecting unit and arranged orthogonally to the conveying path of the sheet. The quantity of skew of the sheet is detected 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. Position information of the sheet with respect to the hole punching section is calculated 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.