Patent · US Expired

Image forming apparatus

US6421137B1 · kind B1 · utility

17Cited by
2References
24Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 26, 1999
Grant dateJul 16, 2002
Priority date
Expiry dateApr 26, 2019

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2221/1823
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In an image forming apparatus in which a photosensitive drum has the form of a cartridge, a non-volatile memory is provided on the cartridge and a cumulative number of times image forming has been performed is stored in the non-volatile memory, a write-in-progress flag is set in the memory before a data set is written to the memory of the cartridge, and the write-in-progress flag is reset after writing of a data set to the memory ends. A plurality of identical data sets are written to the memory. If, when data sets are read out of the memory, there is a data set for which the write-in-progress flag is still in the set state, it is judged that the write operation for this data set ended in mid-course and, hence, the content of this data set is rewritten to the content of another valid data set.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.