Patent ID: 8144362

Claim:
An image forming apparatus comprising: an apparatus main body; at least one first replaceable unit mounted on the apparatus main body so as to be replaced by another unit; a first information storing unit provided in the first replaceable unit and having specific information written; a second information storing unit provided in the apparatus main body in which specific information can be written; a receiving unit that receives the specific information from the first replaceable unit; a writing unit that writes the specific information received by the receiving unit to the second information storing unit; a comparing unit that compares the specific information written in the second information storing unit by the writing unit with information obtained from a second replaceable unit to replace the first replaceable unit; and a deciding unit that decides whether the second replaceable unit is a perfect product or a product other than the perfect product in accordance with the compared result of the comparing unit, wherein the second replaceable unit has toner with an electrifying capacity, the electrifying capacity being modified based on a decision of whether the second replaceable unit is the perfect product or the product other than the perfect product.