Abstract: A method of making a physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other methods are disclosed.

Abstract: A system for use in authentication processes is described comprising a physical unclonable function (“PUF”), a substrate, a plurality of magnetized particles randomly dispersed in the substrate, a PUF reader constructed using multiple discrete magnetometer chips that have magnetic field sensors, placed on a circuit card in an array with a sufficient center to center spacing between sensing elements of adjacent magnetometer chips, wherein the PUF reader measures the magnetic field data at multiple locations in close proximity to the magnetized particles. The measured magnetic field data may be compared to previously enrolled data to assess authenticity.

Abstract: A toner level detection assembly for an electrophotographic image forming device according to one example embodiment includes a magnet connected to a rotatable shaft and rotatable with the shaft around an axis of rotation of the shaft. The magnet is pivotable independent of the shaft about a pivot axis that is spaced radially from the axis of rotation. A magnetic sensor is positioned to sense a magnetic field of the magnet at a point in a rotational path of the magnet and is configured to measure an orientation of the magnetic field of the magnet at the point in the rotational path of the magnet. Processing circuitry in communication with the magnetic sensor is configured to determine an estimate of an amount of toner in a toner reservoir correlating with the measured orientation of the magnetic field of the magnet at the point in the rotational path of the magnet.

Abstract: A toner level detection assembly for an electrophotographic image forming device according to one example embodiment includes a magnet connected to a rotatable shaft and rotatable with the shaft around an axis of rotation of the shaft. The magnet is pivotable independent of the shaft about a pivot axis that is spaced radially from the axis of rotation. A magnetic sensor is positioned to sense a magnetic field of the magnet at a point in a rotational path of the magnet and is configured to measure an orientation of the magnetic field of the magnet at the point in the rotational path of the magnet. Processing circuitry in communication with the magnetic sensor is configured to determine an estimate of an amount of toner in a toner reservoir correlating with the measured orientation of the magnetic field of the magnet at the point in the rotational path of the magnet.

Abstract: A method of making a physical unclonable function (PUF) having magnetic and non-magnetic particles is disclosed. Measuring both magnetic field and image view makes the PUF difficult to counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other methods are disclosed.

Abstract: A physical unclonable function (PUF) apparatus having magnetic particles is disclosed. The magnetic field data and the image view of the magnetic particles in the PUF apparatus are difficult to counterfeit. A PUF apparatus may be incorporated into a user-replaceable supply item for an imaging device. Further, a PUF reader may be incorporated into an imaging device to read the PUF. Other systems are disclosed.

Abstract: A method of manufacturing a physical unclonable function is disclosed. A highly random distribution of magnetic particles within a thermoplastic polymer is created by magnetizing magnetizable particles in solid pellet feed material before feeding the solid pellets into an injection molding machine. Other devices and processes are disclosed.

Abstract: A physical unclonable function is disclosed. A highly random distribution of magnetic particles within a thermoplastic polymer is created by magnetizing magnetizable particles in solid pellet feed material before feeding the solid pellets into an injection molding machine. Other devices and processes are disclosed.

Abstract: Magnetic keys having a plurality of magnetic plates are disclosed. The location and orientation of the magnetic plates are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Abstract: Magnetic keys having a plurality of magnetic layers having holes are disclosed. The location and orientation of the holes are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Abstract: Magnetic keys having a plurality of magnetic layers having holes are disclosed. The location and orientation of the holes are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Abstract: Magnetic keys having a plurality of magnetic plates are disclosed. The location and orientation of the magnetic plates are controlled to generate magnetic fields that are of sufficient strength to be reliably read and sufficient complexity to be difficult to counterfeit. The magnetic keys are located on imaging-device supply items along with non-volatile memory devices containing measurements of the magnetic fields that are digitally signed. These supply items are difficult to counterfeit. Other devices are disclosed.

Abstract: A rotating magnetic physical unclonable function (PUF) is disclosed. Rotating the PUF enables robust low cost PUF readers. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

Abstract: A physical unclonable function (PUF) imaged through two faces is disclosed. The PUF is difficult to counterfeit because the view through both faces must be duplicated for a successful counterfeit. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

Abstract: A physical unclonable function (PUF) apparatus having magnetic particles is disclosed. The magnetic field data and the image view of the magnetic particles in the PUF apparatus are difficult to counterfeit. A PUF apparatus may be incorporated into a user-replaceable supply item for an imaging device. Further, a PUF reader may be incorporated into an imaging device to read the PUF. Other systems are disclosed.

Abstract: A developer roll according to one example embodiment includes a core including at least one permanent magnet forming a magnetized portion of the core. A cylindrical sleeve positioned around the core is rotatable relative to the core about an axis of rotation in an operative rotational direction. A release pole of the permanent magnet is positioned to magnetically attract developer mix to an outer circumferential surface of the sleeve to transport developer mix on the surface of the sleeve in the operative rotational direction when the sleeve rotates relative to the core to a release point where a magnetic field of the permanent magnet is insufficient to retain developer mix against the surface of the sleeve. An axial length of the magnetized portion of the core decreases at both axial ends of the core as the magnetized portion of the core approaches the release point in the operative rotational direction.

Abstract: A developer roll according to one example embodiment includes a core including at least one permanent magnet forming a magnetized portion of the core. A cylindrical sleeve positioned around the core is rotatable relative to the core about an axis of rotation in an operative rotational direction. A release pole of the permanent magnet is positioned to magnetically attract developer mix to an outer circumferential surface of the sleeve to transport developer mix on the surface of the sleeve in the operative rotational direction when the sleeve rotates relative to the core to a release point where a magnetic field of the permanent magnet is insufficient to retain developer mix against the surface of the sleeve. An axial length of the magnetized portion of the core decreases at both axial ends of the core as the magnetized portion of the core approaches the release point in the operative rotational direction.

Abstract: An elongate physical unclonable function (PUF) is disclosed. The PUF has a longitudinal axis and contains a plurality of small magnetic particles. A much larger magnet is positioned on the longitudinal axis to indicate a home position. A low-cost linear translation mechanism may be used to read the PUF by referencing position information to the home position. Other devices are disclosed.

Abstract: A rotating magnetic physical unclonable function (PUF) is disclosed. Rotating the PUF enables robust low cost PUF readers. PUF may be incorporated into a user-replaceable supply item for an imaging device. A PUF reader may be incorporated into an imaging device to read the PUF. Other systems and methods are disclosed.

Abstract: A physical unclonable function (PUF) located on a supply item for an imaging device is disclosed. The PUF is advantageously located on the back side of the supply item opposite a handle. This configuration enables a PUF reader to be located at the end of the insertion path of the supply item where it is protected from damage. Other devices are disclosed.