Abstract: An image forming apparatus includes an image carrier, a developing device, a voltage applier, a current detector, a cleaning blade, and a control device. The control device acts as a measurer and an estimator. The measurer changes the DC bias to a first value and a second value, and acquires a first magnitude of the developing current corresponding to the first value, and a second magnitude of the developing current corresponding to the second value, from the current detector. The estimator calculates a current ratio between the first magnitude and the second magnitude, and estimates deterioration status of the cleaning blade, according to the value of the current ratio.
Abstract: Provided is a developing device having a first transport member and a second transport member that are disposed in a first transport path and a second transport path provided at an upper side and a lower side in a gravitational direction. The transport members transport a developer so as to cause the developer to circulate between the first transport path and the second transport path. A partition wall that separates the first transport path and the second transport path from each other and has an opening including an open-close member that opens and closes the opening.
Abstract: A fuser having a heater, a holder, and a connector, is provided. The heater is in a form of a planar plate. The heater has a metal-made base plate having a recessed portion, a heating pattern having a resistance-heating element arranged on the base plate, and a plurality of power-supplying terminals conductive to the heating pattern. The plurality of power-supplying terminals are located in an end area in the heater on one side in a lengthwise direction of the heater. The holder supports the heater and has a projecting portion configured to contact the recessed portion in the lengthwise direction. The connector has electrodes connectable with the plurality of power-supplying terminals. The recessed portion is located between the heating pattern and one of the plurality of power-supplying terminals closest to the heating pattern in the lengthwise direction.
Abstract: An image forming apparatus includes: a development device which develops an electrostatic latent image formed on a photosensitive drum into a toner image; a charger which charges the photosensitive drum; a development power supply which applies a prescribed bias voltage to the development device; and a calculating section which calculates a surface potential of the photosensitive drum based on a development current flowing in the development device. The calculating section calculates, as the surface potential, a bias voltage at which a non-charging development current that flows in the development device in an uncharged state in which the charger has not charged the photosensitive drum is equal to a charging development current that flows in the development device in a charged state in which the charger has charged the photosensitive drum.
Abstract: An image forming apparatus includes a control unit that controls a conveyance velocity of conveying a recording medium by a fixing unit, to form a loop in the recording medium between a transfer nip portion and a fixing nip portion, in which the control unit controls the conveyance velocity to decrease the loop when a rear end of the recording medium reaches a first position that is apart upstream, in the conveyance direction, from a conveying nip portion of a conveying unit, by a distance that corresponds to a circumference length of a pressure-applying rotating member multiplied by an integer.
Abstract: A developing device includes a storage portion storing a developer, a conveying portion stirring and conveying the developer in the storage portion, a sensor, an acquisition processing portion, and a correction processing portion. The sensor outputs an electrical signal in accordance with magnetic permeability at a predetermined detection position in a conveyance path of the developer. The acquisition processing portion acquires a specific value based on the electrical signal outputted during a rotation period of the conveying portion. The correction processing portion corrects the specific value based on a rotation speed of the conveying portion when a fluctuation width of the electrical signal outputted during the rotation period of the conveying portion is less than a predetermined threshold, and corrects the specific value based on the rotation speed of the conveying portion and the fluctuation width when the fluctuation width is equal to or greater than the threshold.
Abstract: A heater includes a base, a resistor pattern, and a circuit breaker. The resistor pattern includes a plurality of rows of resistors extending in a longitudinal direction of the base. The plurality of rows of resistors are spaced away from each other in a short-side direction orthogonal to the longitudinal direction of the base, coupled in parallel, and configured to generate heat by energization. The circuit breaker is disposed across the plurality of rows of resistors in the short-side direction and configured to cut off power supply to the resistor pattern when a temperature of any one of the plurality of rows of resistors reaches a high temperature threshold.
Abstract: A heating device includes a cylindrical film a heater disposed inside the cylindrical film on an inner surface of the cylindrical film. The heater has a plurality of heating elements on a first surface that are spaced from each other at intervals along an axial direction. A heat transfer member contacts a second surface of the heater. The heat transfer member is arranged such that, in a first region of the heater that includes just a single one of the heating elements, contact between the heater and heat transfer member is greater than in a second region of the heater that includes an interval between a pair of adjacent heating elements.
Abstract: An example image forming apparatus includes a photoconductor, a driving unit to rotate the photoconductor, a charging device, a power unit to apply a charging voltage to the charging device, a current measuring unit to measure a current flowing through the charging device and the photoconductor, and a processor. The processor may determine a charging voltage by controlling the driving unit to rotate the photoconductor at a plurality of different rotational speeds, controlling the power unit to apply at least one test charging voltage to the charging device at each of the plurality of different rotational speeds, and determining a charging voltage based on a current measured at each of the at least one test charging voltage through the current measuring unit, and control the charging voltage according to states of the photoconductor and the charging device, based on a result of the performing of the charging voltage determination process.
March 18, 2020
Date of Patent:
December 6, 2022
Hewlett-Packard Development Company, L.P.
Abstract: A developing device includes: a housing in which a developer is contained; a cover member configured to cover an upper opening of the housing; a developer holder that is supported by the housing and holds the developer on an outer surface and rotates; and a regulating member that faces the developer holder and is configured to regulate an amount of the developer on the outer surface. The device also includes a first exit path inclined toward an inside of the housing which is configured to exit air from the inside of the housing to an outside of the cover member. A second exit path connects the first exit path and a filter member provided on the cover member, in which the filter member prevents passage of the developer and allows for passage of air.
Abstract: An image forming apparatus includes: an annular transfer belt having an outer surface on which an image is transferred; a nip portion that forms a nip region for nipping a recording medium with an outer surface of the transfer belt; a facing portion that faces the nip region from an inner side of the transfer belt and transfers the image from the transfer belt to the recording medium in the nip region by charging the transfer belt; and a transport unit including a holding portion that holds the recording medium, transports the recording medium by moving the holding portion, and causes the recording medium together with the holding portion to pass the nip region while holding the recording medium at the holding portion.
Abstract: A fixing apparatus includes a rotatable belt, a rotatable pressurizing member, a steering roller, a contact portion, a detected portion, a sensor, and a guiding portion. The contact portion comes into contact with an end portion, in the width direction, of the belt. A position of the detected portion is changed on a basis of a position of the contact portion. The sensor detects the position of the detected portion. An inclination of the steering roller is controlled on a basis of a detection result of the sensor. The guiding portion is provided by connecting with the contact portion. The lubricant is guided from the contact portion to the guiding portion. The guiding portion is provided in a region below the contact portion in a vertical direction, inside of the belt, and overlapped with the belt in the width direction.
Abstract: A developing apparatus includes a developer carrying member configured to carry developer, and a developer supply member configured to supply the developer to the developer carrying member, the developer supply member including a shaft, first and second driving members disposed at a first end and a second end of the shaft, respectively, and a toner supply unit disposed between the first end and the second end of the shaft, wherein the first driving member receives a driving force for rotating the developer supply member, and the second driving member outputs the driving force, and wherein the second driving member is mounted to the shaft without play in a rotational direction of the developer supply member with respect to the shaft.
Abstract: A heating device includes a heater and a feeding member. The heater includes a base and an electrode mounted on an electrode mounting face of the base. The feeding member includes a connector terminal and a restrictor. The connector terminal contacts the electrode. The restrictor engages the heater and restricts displacement of the feeding member relative to the heater.
Abstract: A toner conveying device includes a case that can store therein toner to be conveyed, a conveyance member rotatably supported at both ends thereof by the case and configured to rotate to convey the toner inside the case in a conveying direction set in advance, and a pushing member pushed against the conveyance member and configured to slide on an outer peripheral portion of the conveyance member as the conveyance member rotates. The pushing member includes a first sheet member having flexibility and abutting on the outer peripheral portion in a first direction intersecting with a rotational axis direction of the conveyance member to push the conveyance member and a second sheet member having flexibility and abutting on the outer peripheral portion in a second direction, which is different from the first direction, intersecting with the rotational axis direction to push the conveyance member.
Abstract: An image forming apparatus includes an image forming unit configured to form a toner image on an image bearing member, a first unit including an intermediate transfer belt on which the toner image is transferred from the image bearing member and a first roller disposed in contact with an inner surface of the intermediate transfer belt to stretch the intermediate transfer belt, the first unit being drawable from a main body of the image forming apparatus, a second unit including a second roller configured to form, with the first roller, a transfer nip portion in which the toner image is transferred from the intermediate transfer belt to a recording material, the second unit being drawable from the main body, and a high-voltage circuit board disposed in the second unit and configured to apply a voltage to the first roller.
Abstract: Provided is an image forming apparatus including: an annular transfer belt having an outer surface on which an image is transferred; a transferring unit including a transfer cylinder having a transfer area that sandwiches a recording medium with the outer surface of the transfer belt to transfer the image from the outer surface of the transfer belt to the recording medium, and a pair of first rotating bodies disposed on both axial end sides of the transfer cylinder; a pair of circulating members each being wound around the first rotating body and being circulated by rotation of the first rotating bodies; and a holding unit attached to the circulating members, the holding unit configured to hold the recording medium, transport the recording medium with circulation of the circulating members, and pass the recording medium through the transfer area.
Abstract: An image forming apparatus includes an image carrier, a charging device, a developing device, a developing power source, a current measuring device, and a processor. On a surface of the image carrier, an electrostatic latent image is formed. The charging device electrically charges the image carrier. The developing device forms a toner image, by supplying toner to the image carrier and developing the electrostatic latent image formed on the image carrier. The developing power source applies a predetermined bias voltage to the developing device. The current measuring device measures a developing current flowing in the developing device. The processor acts, by executing a control program, as a calculator that calculates a surface potential of the image carrier, on a basis of the developing current measured by the measuring device.
Abstract: An image formation apparatus according to an embodiment includes a fixation device and a controller. The fixation device includes: a fixation member that includes a first region and a second region located closer to a center in a longitudinal direction of the fixation member than the first region; a pressurizing member that forms a nip portion between the fixation member and the pressurizing member; first and second heat generating portions that heat the first and second regions, respectively; a first sensor that detects a first temperature of one of the pressurizing member and the fixation member at a position corresponding to the first heat generating portion; and a second sensor that detects a second temperature of the one at a position corresponding to the second heat generating portion. The controller controls a drive speed of the pressurizing member or the fixation member based on the first and second temperatures.
Abstract: A control circuit executes voltage adjustment processing of adjusting a voltage output from a transfer power source so that a current detected by a detection circuit becomes a predetermined current value. The voltage adjustment processing is executed before a toner image is transferred from at least one of a first image bearing member and a second image bearing member to an intermediate transfer belt. A processor determines whether the second transfer member is in a state of contact or is in a state of separation on the basis of behavior of the current detected by the detection circuit in a period in which the control circuit is executing the voltage adjustment processing.