摘要:
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.
摘要:
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.
摘要:
A physical unclonable function (PUF) located on a supply item for an imaging device is disclosed. The PUF has a toothed rack configured to mate with a gear. During reading operations, the gear turns and translates the PUF linearly under a magnetic sensor. This configuration is inexpensive and robust. Other devices are disclosed.
摘要:
A physical unclonable function formed by an injection molding machine is disclosed. A highly random distribution of magnetic particles is created by magnetizing magnetizable particles before feeding the particles into the injection molding machine due to turbulence within the injection molding machine. Plastic is also fed into the injection molding machine to suspend the particles. Other devices and processes are disclosed.
摘要:
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.
摘要:
An outer sleeve of a magnetic roll for a dual component development electrophotographic image forming device according to one example embodiment includes a series of grooves in an outer surface of the outer sleeve. The grooves extend along an axial length of the sleeve and are spaced circumferentially from each other around the outer sleeve. The outer sleeve has a diameter of between 15 mm and 30 mm, inclusive. The grooves are present on the outer surface of the outer sleeve at a groove density of at least 1.91 grooves/mm of the circumference of the outer surface of the outer sleeve and a total indicated runout of the outer sleeve is 0.05 mm or less.
摘要:
A developer unit for a dual component development electrophotographic image forming device according to one example embodiment includes a housing having a reservoir for storing a developer mix that includes toner and magnetic carrier beads. An auger is positioned to convey developer mix in the reservoir toward the outer surface of a magnetic roll on a front of the housing. A ledge on an inner surface of the housing extends axially with respect to the magnetic roll along a front of the reservoir. The ledge is positioned upstream from a trim bar and downstream from a pickup pole of the magnetic roll with respect to the operative rotational direction of the magnetic roll. The ledge has a concave curved inner surface that is open to the reservoir and extends from near the trim bar to near a front side of the auger.
摘要:
A method and apparatus for retracting a magnetic brush in an imaging device. The apparatus includes a housing containing carrier beads and toner particles; a magnetic structure at least partly disposed within the housing and generating at least one magnetic field; and an endless sleeve disposed around and rotatable about the magnetic structure, at least a portion of the sleeve extending from the housing. During toner development, the magnetic structure is in a first position for developing a magnetic brush of the carrier beads and toner particles along the portion of the sleeve extending from the housing which forms a developer nip with a photoconductor, and during a period of time when toner development is not to be performed, the magnetic structure is in a second position for retracting the magnetic to brush by causing the carrier beads to be positioned against the portion of the endless sleeve extending from the housing forming the developer nip.
摘要:
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.
摘要:
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.