Patent ID: 7733516

Claim:
An image forming apparatus comprising: a hard disk configured to store data relating to forming images, the hard disk including: an image data storage area configured to store image data on a page-by-page basis, an image data management data storage area configured to store management information on the image data stored in the image data storage area on a page-by-page basis, and an other data storage area configured to store data related to other information on image formation processes; an overwrite-block specifying device configured to specify equal size blocks so that a disk memory area is divided into consecutive equal size blocks to be overwritten with overwrite data; an overwrite-data specifying device configured to specify the value of the overwrite data whose size is smaller than that of the equal size block; and a data erase control device operable to overwrite the equal size blocks of the hard disk specified by the overwrite-block specifying device with the value of the overwrite data specified by the overwrite-data specifying device, on a block-by-block basis, wherein the data erase control device is operable to overwrite the image data storage area, starting from the top of each page of the image data stored in the image data storage area, with the value of the overwrite data.