Nova Patents
EP1978440B1

Image forming apparatus, erasing method

Abstract

This record has no abstract on file.

EP1978440B1, drawing sheet 1
Sheet 1 of 60

Term

Term ended

Expired 31 August 2024, 2.1 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

2 claims: 2 independent, 0 dependent

  1. 1
    An image forming apparatus (1) including hardware resources to use for an image forming process, at least one program for conducting a process concerning an image formation, and a hard disk (38) for recording information including an image, said image forming apparatus (1) including:an erase information generating part (S101) generating erase information for erasing the information recorded in the hard disk;and an erase information overwriting part (S105) overwriting the erase information on the information at a sector unit or a cluster unit;characterized in that the image forming apparatus (1) is configured to overwrite a sector unit or cluster unit only if the hard disk is not used by another process;and the erase information generating part and the erase information overwriting part are adapted to perform the steps of a) generating a random number, b) determining whether or not a calculation based on the random number is to be conducted, wherein the calculation is mapping of the random number into a new random number, c) performing the calculation if it is to be conducted, d) overwriting the sector unit or cluster unit with the random number, e) determining if all sector units or cluster units have been overwritten, f) if not all sector units or cluster units have been overwritten, determining whether or not a random number is to be generated for each sector unit or cluster unit, and proceeding to step a) if this is the case and to step d) if this is not the case, g) if all sector units or cluster units have been overwritten, determining whether or not the overwriting process has been completed for a second time and proceeding to step a) if this is not the case, h) if the overwriting process has been completed for the second time, checking whether or not an operator sets a value to overwrite, i) if the operator sets a value to overwrite, overwriting all sector units or cluster units with the value to overwrite, and j) if the operator does not set a value to overwrite, overwriting all sector units or cluster units with zero.
  2. 2
    An erasing method for erasing information recorded in a hard disk (38) in an image forming apparatus (1) including hardware resources to use for an image forming process, at least one program for conducting a process concerning an image formation, and the hard disk (38) for recording information including an image, said erasing method involving:generating erase information for erasing the information recorded in the hard disk (38);and overwriting the erase information on the information at a sector unit or a cluster unit;characterized by overwriting a sector unit or cluster unit only if the hard disk is not used by another process, and generating erase information and overwriting the erase information including the steps of: a) generating a random number, b) determining whether or not a calculation based on the random number is to be conducted, wherein the calculation is mapping of the random number into a new random number, c) performing the calculation if it is to be conducted, d) overwriting the sector unit or cluster unit with the random number, e) determining if all sector units or cluster units have been overwritten, f) if not all sector units or cluster units have been overwritten, determining whether or not a random number is to be generated for each sector unit or cluster unit, and proceeding to step a) if this is the case and to step d) if this is not the case, g) if all sector units or cluster units have been overwritten, determining whether or not the overwriting process has been completed for a second time and proceeding to step a) if this is not the case, h) if the overwriting process has been completed for the second time, checking whether or not an operator sets a value to overwrite, i) if the operator sets a value to overwrite, overwriting all sector units or cluster units with the value to overwrite, and j) if the operator does not set a value to overwrite, overwriting all sector units or cluster units with zero.