The present invention generally relates to image forming apparatuses, and more particularly to an image forming apparatus which detects whether or not a loaded maintenance unit conforms to functions of the image forming apparatus. The maintenance unit refers to units such as a photosensitive unit and a developing unit which are detachably loaded with respect to the image forming apparatus and usually need to be attended to periodically.
Conventionally, the image forming apparatus which has the detachable maintenance unit is provided with a means such as a switch and a relay for detecting whether or not the maintenance unit is correctly loaded into a predetermined position within the image forming apparatus. However, such a means detects that the maintenance unit is loaded into the predetermined position regardless of whether or not the maintenance unit is treated (authorized or approved) as a genuine part by the manufacturer of the image forming apparatus.
A non-genuine maintenance unit is often poor in quality compared to a genuine maintenance unit and the non-genuine maintenance unit cannot fully bring out the intended functions of the image forming apparatus. For example, in a case where a non-genuine developing unit is loaded into the image forming apparatus, a correct image formation cannot be guaranteed due to differences in the characteristics of toners of the non-genuine developing unit and the genuine developing unit. Therefore, the conventional image forming apparatus suffers problems in that the functions of the image forming apparatus may deteriorate and a trouble may occur when the non-genuine maintenance unit is loaded into the image forming apparatus, because the image forming apparatus only has the means for detecting whether or not the maintenance unit is correctly loaded into the predetermined position within the image forming apparatus.