Apparatus and method for detecting the state of a consumable product such as a replaceable toner cartridge

An apparatus for detecting the state of a consumable for a printer, comprising:

• a consumable cartridge having a rotatable member carried by the cartridge;
• a drive motor configured to rotate the rotatable member;
• a current measuring device associated with the motor and operative to measure current flow through the motor;
• memory configured to store a predetermined value corresponding to current flow through the motor and indicative of a change in state of the rotatable member;
• processing circuitry coupled with the current measuring device and the memory and operative to determine when the measured current flow corresponds to the predetermined value of current flow;
• and
• at least one drive gear coupled between the rotatable member and the drive motor, the drive gear communicating with a mechanical resistance element such that, during initial use, measured current flow through the motor is caused to be elevated,
• wherein the processing circuitry further identifies a state of the consumable cartridge.

An apparatus for detecting the operating state of a toner cartridge, comprising:

• a drive motor configured to communicate with a developer roll of a toner cartridge engaged for co-rotation with a photoconductive drum, the drive motor operative to rotate the developer roll;
• a torque detection device coupled with the motor and operative to measure torque generated by the motor;
• a data storage device operative to store at least one target value representative of torque generated by the motor when rotating the developer roll and indicative of a change in operating state of the developer roll;
• and
• processing circuitry communicating with the torque detection device and the data storage device and operative to compare the measured torque and the target value of torque to determine when a change in operating state of the developer roll has occurred.

An apparatus for detecting the operating state of a toner cartridge, comprising:

• a drive motor configured to communicate with a rotatable member of a toner cartridge, the drive motor operative to rotate the rotatable member;
• a mechanical resistance element associated with the rotatable member, communicating with the drive motor, and operative to generate an initial increase in torque generated by the drive motor when the toner cartridge is in a new use state;
• a torque detection device coupled with the motor and operative to measure torque generated by the motor;
• a data storage device operative to store at least one target value representative of torque generated by the motor when rotating the rotatable member and indicative of a change in operating state of the rotatable member;
• and
• processing circuitry communicating with the torque detection device and the data storage device and operative to compare the measured torque and the target value of torque to determine when a change in operating state of the rotatable member has occurred.

A method of determining the operating state of a replaceable cartridge, comprising the steps of:

• providing a drive motor configured to drive in rotation a rotatable member of the cartridge, wherein the rotatable member is engaged in co-rotation with a photoconductive drum, and a current measuring device configured to detect current flow through the drive motor when driving the rotatable member;
• detecting current flow through the drive motor with the current measuring device;
• comparing the detected current flow with a predetermined value of current flow indicative of a change of operating state for the cartridge, wherein the predetermined value of current flow is indicative of surface condition of the photoconductive drum;
• and
• determining surface condition of the photoconductive drum based upon the compared detected current flow and predetermined value of current flow.