Patent ID: 8543014

Claim:
An image forming apparatus, comprising: a photoconductive drum on which an electrostatic latent image is formed; a container having a first chamber that contains a developer made of toner and a carrier, and a receive port in communication with the first chamber; a developing roller configured to develop the electrostatic latent image on the photoconductive drum with toner from the container; a toner cartridge having a second chamber that contains a supply of toner, and a discharge port in communication with the second chamber, the toner cartridge configured to transport toner from the discharge port to the receive port in the container; a rewritable storage medium fixed to the toner cartridge and configured to store specific data therein, the specific data uniquely identifying the toner cartridge and indicating whether the toner cartridge is old or new; a sensor configured to detect a toner amount in the toner cartridge; and a controller configured to determine whether the toner cartridge is indicated as old or new according to the specific data, and to store random data as the specific data in the rewritable storage medium if the controller determines that the toner cartridge is indicated as new.