Image-forming device having consumable component with internal fuse

An image-forming device having a consumable component and a counter that indicates cumulative usage of the consumable component by counting repetitions of a predetermined repetitive operation, the consumable component having an internal fuse, the internal fuse being blown by a flow of current when the consumable component is installed, the image-forming device comprising:

• first decision means for measuring a resistance of the internal fuse a first predetermined time after said flow of current begins, thereby determining whether the internal fuse is normal;
• second decision means for measuring the resistance of the internal fuse, thereby determining whether the internal fuse has blown within a second predetermined time following the first predetermined time;
• memory means for storing a fuse defect indication;
• setting means for setting the fuse defect indication if the internal fuse fails to blow within the second predetermined time, and clearing the fuse defect indication if the internal fuse blows within the second predetermined time;
• and
• resetting means for resetting the counter if the internal fuse is determined to be normal and blows within the second predetermined time, the resetting means also resetting the counter if the internal fuse is determined to be normal and the fuse defect indication is in a cleared state.

A method of blowing a fuse and resetting a counter in an image-forming device, the fuse being disposed in a consumable component of the image-forming device, the counter counting a repetitive operation performed when the consumable component is used in order to measure a service life of the consumable component, the method comprising:

• supplying a flow of current to the fuse;
• measuring a resistance of the fuse;
• resetting the counter and halting the supply of said current if the measured resistance exceeds a first predetermined value within a first predetermined time;
• halting the supply of said current and checking a fuse defect indication in a memory in the image-forming device if the resistance of the fuse is still below the first predetermined value after the first predetermined time, issuing an alarm if the fuse defect indication is set, and setting the fuse defect indication if the fuse defect indication is cleared;
• and
• clearing the fuse defect indication if the resistance of the fuse exceeds the first predetermined value within the first predetermined time.

A consumable component of an image-forming device, comprising:

• two points of electrical contact between the consumable component and the image-forming device;
• a fuse coupled to at least one of the two points of electrical contact, the fuse being blown by the image-forming device to indicate that the consumable component is no longer new;
• and
• a resistor coupled to at least one of the two points of electrical contact.