Patent ID: 6154619
Filing Date: 2000-11-28
Classification: G03G

Abstract:
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 including a look-up table configured to store at least one predetermined set of characteristic values of rotatable member torque versus motor current flow for a characteristic consumable cartridge, wherein the at least one characteristic value of current flow corresponds to current flow through the motor and wherein the at least one characteristic value of rotatable member torque is indicative of a change in state of the rotatable member; andprocessing circuitry coupled with the current measuring device and the memory and operative to determine when the measured current flow corresponds to the predetermined at least one characteristic value of current flow;wherein the processing circuitry further identifies a state of the consumable cartridge.