Image forming device, identifying device, semiconductor integrated device, and identifying method

In an image forming device, a plurality of objects are detachably disposed, each of the objects having a storage area to store object-related information of the object, and configured to return, in response to an acquisition request, a signal with a voltage in a predetermined range which is distinctly different among the objects, the signal carrying the object-related information of the object. The image forming device includes a transmitting unit that transmits acquisition requests of object-related information to the objects respectively, a receiving unit that receives signals from the objects respectively, a voltage detection unit that detects a range of voltage of each of the signals received, and an identifying unit that identifies each of the objects respectively based on the ranges of voltage detected.