Abstract: Disclosed is a developing device including a conveying screw and an inductance sensor. The inductance sensor includes a detector detecting magnetic permeability of the developer accommodated in a developing container and has such detection sensitivity that the detection sensitivity with which the detector detects magnetic permeability when a magnetic material is disposed at a position 1 mm away from the detector in a vertical direction is 10% or more of that when magnetic material is disposed at a position which is in contact with the detector. The conveying screw includes a rotary shaft; a blade which is spirally formed on an outer circumference of the rotary shaft; and a rib formed as to protrude outwardly from the outer circumference of the rotary shaft. The rib is disposed opposite the detector with respect to a conveying direction of the conveying screw. The rib is provided with a magnet.

Abstract: An image formation apparatus includes an image-bearing member, an exposure device, an electro-conductive member, a bias application unit and a development device having a development roller and a toner supply roller. The bias application unit configured to apply biases to the toner supply roller, the development roller, and the electro-conductive member during image formation so that a first potential difference between the toner supply roller and the development roller and a second potential difference between the electro-conductive member and the development roller cause normally charged toner to travel respectively from the toner supply roller and the electro-conductive member to the development roller, and a third potential difference between the electro-conductive member and the toner supply roller causes normally charged toner to travel from the electro-conductive member to the toner supply roller.

Abstract: An image formation apparatus includes an image-bearing member, an exposure device, an electro-conductive member, a bias application unit and a development device having a development roller and a toner supply roller. The bias application unit configured to apply biases to the toner supply roller, the development roller, and the electro-conductive member during image formation so that a first potential difference between the toner supply roller and the development roller and a second potential difference between the electro-conductive member and the development roller cause normally charged toner to travel respectively from the toner supply roller and the electro-conductive member to the development roller, and a third potential difference between the electro-conductive member and the toner supply roller causes normally charged toner to travel from the electro-conductive member to the toner supply roller.

Abstract: A third communicating portion is disposed downstream of the first communicating portion and upstream of the second communicating portion in the first direction. The third communicating portion is disposed above a rotational axis of a first conveyance screw and a rotational axis of a second conveyance screw in a vertical direction. The third communicating portion is configured to allow air inside the developing container to move between the first chamber and the second chamber. An opening portion for discharging the air inside the developing container outside the developing container is disposed above the second chamber in the vertical direction.

Abstract: An image forming apparatus includes a permeability sensor configured to detect information on magnetic permeability of developer contained in a developer container for detecting toner density of the developer, and a controller configured to control a control voltage applied to the permeability sensor so that (i) a value of the control voltage that is applied to the permeability sensor in a case where a predetermined condition including a condition that the toner density of the developer contained in the developer container is a predetermined density is satisfied and an amount of the developer contained in the developer container is a first amount is greater than (ii) a value of the control voltage applied to the permeability sensor in a case where the predetermined condition is satisfied and the amount of the developer contained in the developer container is a second amount greater than the first amount.

Abstract: An image forming apparatus includes a control portion, and in a first period from when use of a developing apparatus is started until when an amount of developer in a developing device reaches a predetermined amount larger than an amount of initial developer, when an amount of developer supplied from a supplying portion through a single supplying operation in an image forming operation is larger than a predetermined supplied amount, the control portion interrupts the image forming operation and drives a conveyance portion for a predetermined time. In a second period after the amount of the developer reaches the predetermined amount, when an amount of the supplying developer supplied through a single supplying operation in the image forming operation is larger than the predetermined supplied amount, the control portion continues the image forming operation without interruption.

Abstract: An image forming apparatus includes a density detecting portion configured to detect a density of a control toner image being formed every time when an image is formed on a predetermined number of sheets in successively forming the image on sheets, and a control portion configured to control an amount of supplying developer. The control portion controls forming of the control toner image so that the predetermined number of image-formed sheets is a first number in a period of time from when the use of a developing apparatus is started, until when an amount of developer of the developing apparatus reaches a set value which is larger than an amount of initial developer, and the predetermined number of image-formed sheets is a second number which is larger than the first number of image-formed images, after the amount of developer of the developing apparatus reaches the set value.

Abstract: A first amount of developer is sealed in a container of a developing unit in an initial state where the developing unit is not yet used. A discharge portion is configured to discharge the developer from the container in a case where the developer contained in the container exceeds a predetermined amount greater than the first amount. A permeability sensor is configured to output a detection signal correlated with a magnetic permeability of the developer within the container. A controller is configured to use different values of a control signal, for adjusting an input-output relationship between the magnetic permeability of the developer in the container and the detection signal output from the permeability sensor, in a state where a second amount greater than the first amount of the developer is contained in the container and in a state where the first amount of the developer is contained in the container.

Abstract: A developer conveying apparatus for conveying a developer that develops an electrostatic latent image includes a rotation unit which rotates around a rotation shaft extending in an axial direction and parallel to a developer conveying direction, a first developer conveying portion which is provided in the rotation unit and which has an opening configured to convey the developer in a first axial direction of the rotation shaft, and a second developer conveying portion which is provided in the rotation unit and which has an opening configured to convey the developer in a second axial direction opposite to the first axial direction. A distance from the rotation shaft to the opening in the first developer conveying portion is different than a distance from the rotation shaft to the opening in the second developer conveying portion.

Abstract: A developer conveying apparatus for conveying a developer that develops an electrostatic latent image includes a rotation unit which rotates around rotation shaft pallalel to a developer conveying direction, a first developer conveying portion which is provided in the rotation unit and which conveys the developer in an axial direction of the rotation shaft, and a second developer conveying portion which is provided in the rotation unit at a position where a distance from the rotation shaft is different from that of the first developer conveying portion, and which conveys the developer in a direction opposite to that of the first developer conveying portion.

Abstract: An image forming apparatus includes an image bearing member, a charging device which charges the image bearing member, an exposure device which exposes the charged image bearing member to light, a developing device having a developer carrying member, and developing the electrostatic latent image by supplying the developer from the developer carrying member, and an instructing portion which generates an instruction signal for instructing to perform a developer install mode for installing developer in the developing device at a time of non-image formation. In the developer install mode a control portion sets an absolute value of a potential on the image bearing member charged by the charging device to a value which is smaller than an absolute value of a potential of the developer carrying member caused by a direct current component of the bias to be applied to the developing device and larger than an absolute value of an image dark section potential on the image bearing member at the time of image formation.

Abstract: An image forming apparatus including a control portion which controls a bias to be applied to a charging roller for charging a photosensitive member to a predetermined potential or a developing roller for supplying toner to the photosensitive member, in which the control portion performs a developer install mode for controlling the bias to be applied to the charging roller or the developing roller during replenishment of toner to a developing container to be used for the first time, and at a time of the developer install mode, controls the bias to be applied to the charging roller or the developing roller so as to obtain a developing electric field (Vcont2) for developing toner having an excessive charge amount onto the photosensitive member, which is smaller than a developing electric field (Vcont1) for developing toner onto the photosensitive member at a time of image formation.

Abstract: According to one embodiment, a storage apparatus includes: a reader configured to read a sector recorded in a storage medium; a detector configured to detect a sync mark in the sector; a determiner configured to determine the position of the data region of the sector based on the sync mark detected by the detector; a data generator configured to generate data of the data region based on the data region, the position of the data region being determined by the determiner; a first judging module configured to judge whether the data generated by the data generator is normal; and a data compartment recorder configured to record a data compartment in the storage medium distinguishably from other data compartments, the recorded data compartment comprising a data region from which, among the data generated by the data generator, data judged as abnormal is generated.

Abstract: A stepping motor is provided with a plate spring for pressing a housing and a rotor against each other. One of the housing and the rotor is provided with a projection. Variations in position, which is inherent in position control by a related art stepping motor, due to lack of a retaining force subsequent to an initial position setting or due to variations in rotating speed of the motor, are eliminated. Thus the motor is suitably used for controlling of the position of, for example, an HID lamp unit.

Abstract: A check valve has a valve element 12 integral with a metallic bushing 11 and made of a substantially annular rubber material. A hole is provided in the center of the valve element, and a shaft 13 passes through the hole. A spring 2 is mounted around the shaft, and a back face of the valve element is supported at one end of the spring through the metallic bushing. A truncated conical stopper 4 includes a recess at an intermediate portion, and is mounted downstream of the valve element to restrict the amount of movement and deformation of the valve element. The stopper is fixed at one end 13b of the shaft. It is thereby possible to provide a reliable check valve in which flow resistance can significantly be reduced, and sufficient safety can be established against counter flow pressure.