PUNCHING DEVICE, POST-PROCESSING DEVICE AND IMAGE FORMING DEVICE USING IT

摘要

PROBLEM TO BE SOLVED: To provide a punching device and an image forming device using it capable of improving positional accuracy of a punch hole, and to automatically staple and punch in forms desired by a user in a post-processing device provided with both a stapling device and the punching device. SOLUTION: The punching device is provided with a belt 62 composing a stacking means and a punching device body 64 opening punch holes in rear ends of sheets S accumulated on the belt 62. A height of the sheets S accumulated on the belt 62 is detected, and the number of the sheets S to be accumulated on the belt 62 is determined in response to the height of the sheets S. The sheets S accumulated on the belt 62 are punched as a bundle by the punching device body 64, and they are ejected by the belt 62. The number of sheets changes in accordance with punching ability of the punching device body 64, and compatibility between productivity and positional accuracy can be provided.