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AssigneeLexmark International, Inc.
InventorsStephen Porter Bush, Timothy John Rademacher, Christopher Alan Adkins, Jennifer Topmiller Williams, Gregory Scott Woods
Estimating the term…
A supply item has toner for use in an imaging device. A chip has memory storing quanta indicating allowed usage of the supply item over its lifetime and a multiplier correlating the quanta to toner mass. The imaging device requires quanta to conduct imaging operations and loads the quanta and multiplier by way of a certificate stored in the memory. The imaging device retrieves quanta from the chip over time and both devices keep tally. Initialization between the supply item and imaging device includes providing encrypted and unencrypted instances of firmware versions and certificates from the supply item that the imaging device can compare for security. Alternatively, the supply item defines a fuser assembly, imaging unit, intermediate transfer member, or other component installed for use in the imaging device.
A chip for installation with a supply item cartridge having imaging toner that is installed in an imaging device and configured for communication with a controller of the imaging device on a slave node of an I2C communications bus while the controller is configured on a master node of the I2C communications bus, comprising a memory storing a device unique public key signed by a global key, a certificate having quanta indicating allowed usage of the imaging toner over a lifetime thereof, and a multiplier correlating the quanta to mass of the imaging toner, wherein the certificate is configured to be read by the imaging device upon a command requesting loading of the certificate in the imaging device, and further wherein the certificate further includes types of imaging devices suitable for use with the chip.
Dependencies are inferred from the claim text.