Abstract: To provide an image forming apparatus improving discharging of a developer from charge providing member for providing charge to the developer remaining on an image bearing member to the image bearing member, the developer is charged from the charge providing member to the image bearing member. When a developer discharging region of the image bearing member is disposed at a charging position, charging member is applied with a voltage having a direct current component of an absolute value equal to or smaller than an absolute value of voltage applied to the charge providing member without an alternating current component.

Abstract: An image forming apparatus includes a developing device including a developing receptacle for accommodating a developer including a toner and a carrier, and a detector for outputting a signal corresponding to a toner density of the developer within the developer receptacle, a replenishing member for replenishing the toner to the developing receptacle in accordance with an output value from the detector, a first storage unit having a storage region storing information relating to characteristics of the developer, and a controller for controlling a replenishing operation by the replenishing member based on the output value from the detector and the information relating to characteristics of the developer.

Abstract: The image forming apparatus includes: a plurality of image forming units each having an image bearing member and a developing unit; and a transfer member provided to be able to contact the plurality of image bearing members. The toner used in at least one of the plurality of developing units contains a toner particle group with a particle size of 12.7 &mgr;m or more, a ratio of the toner particle group to the entire toner being 1.0% or less. Accordingly, incomplete transfer can be prevented.

Abstract: An image forming apparatus includes a photosensitive drum, a charge roller for charging the photosensitive drum, a developing device for developing an electrostatic latent image formed on the charged photosensitive drum with a developer, a first auxiliary charging brush which is located upstream from the charge roller in a movement direction of a surface of the photosensitive drum and applies a voltage of a polarity opposite to a normal polarity of a polarity opposite to a normal polarity of the developer, and a second auxiliary charging brush which is located downstream from the first auxiliary charging brush and upstream from the charge roller and applies a voltage of a polarity identical to the normal polarity of the developer. In the image forming apparatus, the first auxiliary charging brush is supplied with an AC voltage to be improved in recovery performance of a transfer residual developer, and contamination of charging means can be prevented.

Abstract: A process cartridge adapted to be detachably attached to a body of an image forming apparatus comprises an image bearing member, developing means for developing an electrostatic image formed on the image bearing member by using developer to form a developer image on the image bearing member and developer charging means for charging residual developer on the image bearing member disposed downstream of a transferring position at which said developer image is transferred onto a transfer destination member and upstream of a position at which the electrostatic image is formed on said image bearing member with respect to the moving direction of said image bearing member. The developer charging means can be in contact with the image bearing member and is movable in a direction substantially the same as a longitudinal direction of the image bearing member upon charging the residual developer.

Abstract: Provided is an image forming apparatus, which includes a photosensitive drum, a charging roller, a transfer roller, and a toner charging brush, reciprocates the toner charging brush in a longitudinal direction of the photosensitive drum. In the image forming apparatus, when a number of rotations per a unit time of the image bearing member is assumed to be “a” and a number of times of reciprocation per unit time of the toner charging brush is assumed to be “b”, assuming that R=b/a, R is set to be in a range of {fraction (1/25)}≦R≦3. However, R=m/n (m and n are integers of 5 or less) is excluded. Consequently, generation of a periodic attachment pattern appearing on the photosensitive drum is eliminated.

Abstract: An object of the present invention is to provide a developing apparatus capable of reducing unevenness of density of an image in a longitudinal direction of a photosensitive member. For this purpose, in the present invention, a developing apparatus includes a developer bearing member, and a developer carrying screw placed adjacently to the developer bearing member in parallel with the developer bearing member, and an inclination angle of “a carrying surface facing in a developer carrying direction of a spiral blade of the developer carrying screw” to a shaft of the developer carrying screw is equal to or less than 60 degrees.

Abstract: To provide an image forming apparatus improving discharging of a developer from charge providing means for providing charge to the developer remaining on an image bearing member to the image bearing member, the developer is charged from the charge providing means to the image bearing member. When a developer discharging region of the image bearing member is disposed at a charging position, charging means is applied with a voltage having a direct current component of an absolute value equal to or smaller than an absolute value of voltage applied to the charge providing means without an alternating current component.

Abstract: An image forming apparatus using a two-component developer including a toner and a carrier as a developer, and provided with a toner replenishing device for replenishing with the toner has remaining amount detecting means for detecting the remaining amount of toner in a toner container, and informing means for generating a signal indicative of a small remaining amount of toner when the remaining amount of toner in the toner container becomes equal to or less than a predetermined amount, and a limit value is made effective only in a state in which the signal indicative of a small remaining amount of toner is being outputted. Also, by the density of the developer in a developing container becoming smaller than a predetermined limit value, a state in which a developing device is not being replenished with the toner from the toner replenishing device is judged. The limit value has a plurality of standards, and a value is selected and used in conformity with the remaining amount of toner in the toner container.

Abstract: The developer agitating member has a shaft portion, a spiral rib and an inclined rib protruding from the outer peripheral surface of the shaft portion and provided in the spiral rib in the axial direction of the shaft portion. Thereby, in a developing apparatus, a process cartridge and an image forming apparatus, the developer agitating member can efficiently agitate and convey a developer.

Abstract: The image forming apparatus has a developer container containing a developer therein, a developer toner density detecting portion for detecting the permeability of the developer in the developer container to thereby detect toner density, and an engine controller for detecting whether the image forming apparatus has gone wrong, on the basis of the toner density detected by the developer toner density detecting portion. Thereby, it becomes possible to detect the failure of a developing apparatus reliably and early by an inexpensive construction.

Abstract: An image forming apparatus using a two-component developer including a toner and a carrier as a developer, and provided with a toner replenishing device for replenishing with the toner has remaining amount detecting means for detecting the remaining amount of toner in a toner container, and informing means for generating a signal indicative of a small remaining amount of toner when the remaining amount of toner in the toner container becomes equal to or less than a predetermined amount, and a limit value is made effective only in a state in which the signal indicative of a small remaining amount of toner is being outputted. Also, by the density of the developer in a developing container becoming smaller than a predetermined limit value, a state in which a developing device is not being replenished with the toner from the toner replenishing device is judged. The limit value has a plurality of standards, and a value is selected and used in conformity with the remaining amount of toner in the toner container.

Abstract: A cartridge detachably mountable to a main body of an image forming apparatus which has a developing device for developing an electrostatic image formed on an image bearing member with two-component developer includes a toner and a carrier. The developing device has a density detecting portion for detecting toner density of a start agent of the developer and the main body of the apparatus performs a setting operation for setting a control value for controlling the density detecting portion on the basis of a detection result of the density detecting portion and storing device for storing information that the setting operation is performed.

Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic image; a developing unit for developing the electrostatic image on the image bearing member with toner electrically charged to a predetermined polarity; a transfer unit for transferring the toner image from the image bearing member to a transfer material; a toner charging unit for electrically charging residual toner remaining on the image bearing member to the same polarity as the predetermined polarity; and an image bearing member charging unit for contacting to the image bearing member carrying the toner charged by the toner charging unit to electrically charge the image bearing member to the same polarity as the predetermined polarity, the image bearing member charging unit being effective to reduce a charge amount of the toner.

Abstract: An image forming apparatus includes an image bearing member for bearing an electrostatic image; developing means for developing the electrostatic image on the image bearing member with toner electrically charged to a predetermined polarity; transfer means for transferring the toner image from the image bearing member to a transfer material; toner charging means for electrically charging residual toner remaining on the image bearing member to the same polarity as the predetermined polarity; and an image bearing member charging means for contacting to the image bearing member carrying the toner charged by the toner charging means to electrically charge the image bearing member to the same polarity as the predetermined polarity, the image bearing member charging means being effective to reduce a charge amount of the toner.

Abstract: A latent electrostatic image developing device for use in developing a latent electrostatic image to a toner image in an image forming machine. The device includes a developing roller within a development housing for holding a developer on its surface in a developer holding zone and conveying the developer, which is held to a developing zone, in order to apply it to a latent electrostatic image. A restricting portion has a blade which includes a rigid part for acting on the surface of the developing roller in a developer restricting zone located between the developer holding zone and the developing zone in order to restrict the amount of the developer held on the surface. The blade is caused to protrude to the upstream side as viewed in the direction of movement of the developing roller, and that border of its protrusion facing the developing roller is provided with a C 0.1 to 0.6 mm chamfer (C being the JIS designation for a 45 degree chamfer).

Abstract: An apparatus for developing an electrostatic latent image includes a developing agent application device which holds the developing agent on the surface thereof in the developing agent-holding zone, and conveys the thus held developing agent into a developing zone to apply it onto the electrostatic latent image. A limiting device is included for limiting the amount of the developing agent held on the surface of the developing agent application device in a developing agent limiting zone located between the developing agent holding zone and the developing zone. The limiting device includes a blade made of a rigid member that is brought into forced contact with the surface of the developing agent application device, a blade support device for supporting the blade in a manner such that a first surface thereof is forced into contact with the surface of the developing agent application device, and a resilient urging device which is disposed on a side of a second surface of the blade.

Abstract: An image forming apparatus includes a charge removing device for removing the residual charge on a photosensitive film. The light emitted from an optical source of the charge removing device is selected from the range between the wavelengths which correspond to half of the maximum absorbance in a light absorbance characteristic of the photosensitive film. Since carrier generation does not occur by the light emitted by the charge removing device, the charging ability and the charge retaining ability of the photosensitive film are improved, and the image quality is significantly improved.

Abstract: An apparatus for developing an electrostatic latent image which includes a developing agent application assembly and a limiting device for limiting the amount of the developing agent held on the surface of the developing agent application assembly. The limiting device is made of a rigid member such as a sheet glass and its one surface is brought into forced contact with the surface of the developing agent application assembly.

Abstract: A developing device constructed such that a rotational axis of a transmission gear which is engaged with a gear attached to the photosensitive drum of an image forming apparatus is fixed in relation the photosensitive drum gear in order to transmit the rotational force of the photosensitive drum to the developing roller via gears, and at the same time the transmission gear axis is rockably suspended and supported as a supporting axis of the developing unit, the developing roller gear is linked with a transmission gear by means of a plurality of gears, and a force which acts to keep the developing unit away from the photosensitive drum is decreased.