Patent ID: 7970293

Claim:
An image forming apparatus comprising: a cartridge configured to be removably attached to a main body, wherein the cartridge is configured to be in one of a new state or a used state, the cartridge comprising: a rotational body positioned within the cartridge, and comprising an extension portion which is positioned offset from a center of the rotational body and configured to protrude outward from the rotational body in an axial direction, wherein the rotational body and the extension portion are configured to selectively be positioned in one of a first state and a second state; an engagement gear positioned within the cartridge, the engagement gear comprises a first engaging portion and a center axis aligned with a center axis of the rotational body, and is configured to selectively rotate, and the rotational body further comprises a second engaging portion, and wherein the engagement gear and the rotational body are configured to selectively be positioned in one of a first gear state in which the second engaging portion and the first engaging portion are separated from each other, and a second gear state in which the second engaging portion engages the first engaging portion; a transmission gear configured to transmit a rotational force to the engagement gear, wherein the engagement gear further comprises: a toothed portion positioned at a first portion of a peripheral surface of the engagement gear; and a toothless portion positioned at a second portion of the peripheral surface of the engagement gear; and a regulating member configured to maintain the toothless portion and the transmission gear in a position in which they face each other, until a predetermined amount of force is applied to the engagement gear, the regulating member comprising: an engaging portion positioned on a shaft portion which is configured to rotatably support the engagement gear, wherein the engaging portion is deformable in a diameter direction of the shaft portion; and an engaging groove formed in the engagement gear, wherein the engaging portion is configured to engage the engaging groove; and a device body comprising the main body, the main body comprising: a driving member configured to rotate the rotational body; a detecting unit configured to detect a movement of the extension portion between the first state to the second state; and a determining unit configured to receive a signal from the detecting unit when the extension portion moves between the first state and the second state, wherein the determining unit calculates an elapsed time between when the driving member starts driving and when the determining unit receives the signal from the detecting unit, wherein the determining unit is configured to determine whether the cartridge is in the new state or the used state, and to determine a type of the cartridge, based on the elapsed time.