Abstract: A charging device includes: a casing provided with an opening opposing a member-to-be-charged; a discharging wire provided in the casing; a grid electrode provided in the opening; a shutter for opening and closing the opening; a cleaning member for cleaning the grid electrode; and a moving mechanism for reciprocating the shutter and the cleaning member along a longitudinal direction of the opening. The moving mechanism includes a driving member for being rotationally driven, a first moving member, held by the driving member, for moving the shutter with rotational drive of the driving member, and a second moving member, held by the driving member, for moving the cleaning member with the rotational drive of the driving member.

Abstract: An image forming apparatus includes a photosensitive member (drum); a rotatable charging member for electrically charging the drum; a bias applying device for applying a charging bias to the charging member in the form of a DC voltage biased with an AC voltage; a current detector for detecting an AC current passing between the charging member and the drum; a temperature and humidity detector; a setting device for setting a condition of the charging bias on the basis of a plurality of detected AC currents passing between the charging member and the drum when a plurality of AC voltages depending on an output of the temperature and humidity detector are applied to the charging member; and a corrector for correcting the set condition of the charging bias on the basis of an output of the current detector when a predetermined AC voltage is applied to the charging member.

Abstract: An image forming apparatus of a representative configuration of the present invention includes a photosensitive drum, which carries an electrostatic latent image, and a developing sleeve, which carries a two-component developer and develops the electrostatic latent image on the photosensitive drum into a toner image. Moving directions of the photosensitive drum and the developing sleeve are opposite at an opposing portion in a developing device having a speed changing portion, which changes the driving speed of the developing sleeve, and a controller, which switches a target speed of the developing sleeve so that it is driven at a second velocity, before it is driven at the first velocity set in a lower speed mode, when the lower speed mode is executed in which the photosensitive drum is driven at a lower speed than in the normal image forming.

Abstract: An image forming apparatus including a movable image bearing member, a sensor arranged so as to oppose the image bearing member, a shutter member movable between an opened position and a closed position, a vibration mechanism configured to apply vibration to the shutter member, and an executing portion configured to execute a vibrating action which applies vibrations to the shutter member by the vibration device based on image formation history information.

Abstract: A grid of a charging device is cleaned without causing the grid to contact a member to be charged. In this structure, to suppress non-uniform charging due to wear of the grid, which is pulled toward a discharge electrode, for a long time, first and second protective layers are provided. The first protective layer is provided on a surface of a base member of the grid that faces the cleaning member. The second protective layer is provided on a surface of the base member that faces the pressing member. The second protective layer is thicker than the first protective layer.

Abstract: An image forming apparatus includes a charger having a case surrounding a discharge electrode, an opening on the photosensitive member side and a grid disposed in the opening and having a mesh area, a shutter that covers the opening, and first and second contact members. The contact members are disposed on a downstream side of the charger and an upstream side of a cleaning blade in a rotational direction of the photosensitive member and come in contact with areas of the photosensitive member corresponding to both longitudinal ends of the mesh area of the grid.

Abstract: A shutter that suppresses accumulation of discharge products on a photosensitive member is disposed between a grid and the photosensitive member. In this structure, to suppress corrosion of the grid due to the discharge products for a long time, first and second protective layers are provided. The first protective layer is provided on a surface of a base member of the grid that faces the discharge electrode. The second protective layer is provided on a surface of the base member that faces the shutter. The second protective layer is thicker than the first protective layer.

Abstract: A first mode in which a toner image is formed on a surface of a photoconductor by forming an electrostatic latent image with exposure means and a second mode in which a toner image used to adjust a tilt of a corona charger relative to the surface of the photoconductor in a longitudinal direction of the corona charger is output substantially without forming an electrostatic latent image with the exposure means are executable. An oscillating voltage superimposed in a developing bias in the second mode is set such that an amount of change in density of the toner image relative to an amount of change in developing contrast within a predetermined range of the density of the toner image becomes larger for the developing bias used in the second mode than for the developing bias used in the first mode.

Abstract: A charging device includes: a discharging electrode; a casing surrounding the discharging electrode and being provided with an opening in a member-to-be-charged side; a grid electrode provided in the opening and provided with a mesh portion having a plurality of through holes; a cleaning brush, including a base material and a plurality of fibers held on the base material, for cleaning the grid electrode by entrance of a part of the fibers into the through holes while contacting a surface of the grid electrode in the discharging electrode side; a shutter capable of shielding between the member-to-be-charged and the grid electrode; and a moving mechanism for moving the cleaning brush and the shutter along a longitudinal direction of the grid electrode. When the shutter is moved in a closing direction, the cleaning brush moves in advance of a leading end portion of the shutter with respect to the closing direction by a predetermined interval or more.

Abstract: A charging device includes: a casing provided with an opening opposing a member-to-be-charged; a discharging wire provided in the casing; a grid electrode provided in the opening; a shutter for opening and closing the opening; a cleaning member for cleaning the grid electrode; and a moving mechanism for reciprocating the shutter and the cleaning member along a longitudinal direction of the opening. The moving mechanism includes a driving member for being rotationally driven, a first moving member, held by the driving member, for moving the shutter with rotational drive of the driving member, and a second moving member, held by the driving member, for moving the cleaning member with the rotational drive of the driving member.

Abstract: In a Ni-base alloy, an area-equivalent diameter D is calculated. D is defined by D=A1/2 from an area A of a largest nitride in a field of view when an observation area S0 is observed. This process is repeated in n fields of view for measurement, where n is the number of the fields of view for measurement, so as to acquire n pieces of data on D, and the pieces are arranged in ascending order D1, D2, . . . , Dn to obtain a reduced variate yj. The obtained values are plotted on X-Y axis coordinates, where an X axis corresponds to D and a Y axis corresponds to yj. In a regression line yj=a×D+b, yj is obtained when a target cross-sectional area S is set to 100 mm2. When the obtained yj is substituted into the regression line, the estimated nitride maximum size is ?25 ?m in diameter.

Abstract: An image forming apparatus includes an image forming portion for forming an image on a recording material, a sensor to detect a toner image formed by the image forming portion, and a correcting portion to correct an image forming condition of the image forming portion on the basis of a result of detection, by the sensor, of a first control toner image formed by the image forming portion. In addition, a supply controller controls a developer supplying operation on the basis of a result of detection, by the sensor, of a second control toner image formed by the image forming portion. A controller controls an image forming condition such that the first control toner image is formed at the image forming speed of a second image forming mode, and the second control toner image is formed after the image forming speed is changed to a third image forming speed which is higher than the second image forming speed.

Abstract: An image forming apparatus having a photosensitive member, a charging member that charges the photosensitive member to form a charged surface on a surface of the photosensitive member, an applying unit that applies to the charging member a charging bias composed of a direct voltage superimposed with an alternating voltage, and a toner image forming unit that forms a toner image on the charged surface. A current flowing through the charging member when the charging bias is applied to the charging member is detected by a current detection unit, and currents of different predetermined frequency components are respectively extracted from the detected current by extraction units. Based on the extracted currents, the alternating voltage of the charging bias is adjusted by an adjustment unit.

Abstract: The present invention provides an image forming apparatus including a charger that includes a case surrounding the discharge electrode and having an opening on the photosensitive member side and a grid disposed in the opening and having a mesh area, a shutter that includes the fiber opening and closing the opening, and first and second contact members that are disposed on a downstream of the charger and an upstream of the cleaning blade in a rotational direction of the photosensitive member and come in contact with areas of the photosensitive member corresponding to both longitudinal ends of the mesh area of the grid.

Abstract: A shutter that suppresses accumulation of discharge products on a photosensitive member is disposed between a grid and the photosensitive member. In this structure, to suppress corrosion of the grid due to the discharge products for a long time, first and second protective layers are provided. The first protective layer is provided on a surface of a base member of the grid that faces the discharge electrode. The second protective layer is provided on a surface of the base member that faces the shutter. The second protective layer is thicker than the first protective layer.

Abstract: A grid of a charging device is cleaned without causing the grid to contact a member to be charged. In this structure, to suppress non-uniform charging due to wear of the grid, which is pulled toward a discharge electrode, for a long time, first and second protective layers are provided. The first protective layer is provided on a surface of a base member of the grid that faces the cleaning member. The second protective layer is provided on a surface of the base member that faces the pressing member. The second protective layer is thicker than the first protective layer.

Abstract: An image forming apparatus of a representative configuration of the present invention includes a photosensitive drum, which carries an electrostatic latent image, and a developing sleeve, which carries a two-component developer and develops the electrostatic latent image on the photosensitive drum into a toner image. Moving directions of the photosensitive drum and the developing sleeve are opposite at an opposing portion in a developing device having a speed changing portion, which changes the driving speed of the developing sleeve, and a controller, which switches a target speed of the developing sleeve so that it is driven at a second velocity, before it is driven at the first velocity set in a lower speed mode, when the lower speed mode is executed in which the photosensitive drum is driven at a lower speed than in the normal image forming.

Abstract: An image forming apparatus includes a developing device including a developer bearing member for bearing and conveying a developer and configured to develop a latent image formed on an image bearing member using the developer, a bias application unit configured to apply at least an AC bias to the developer bearing member, an integration unit configured to integrate an application time of the AC bias applied by the bias application unit, and a determination unit configured to determine a replacement timing of the developing device based on an integrated value by the integration unit.

Abstract: A copying apparatus detects a non glossy portion (K, M, C, or Y) and a glossy portion (T) of a document based on image data output from a reader unit. The copying apparatus forms an image of the detected non glossy portion (K, M, C, or Y) with a colored toner and an image of the detected glossy portion (T) with a transparent toner, on a sheet, based on the image data output from the reader unit.

Abstract: A control unit decreases the potential difference according to an increase in the drive amounts of the image bearing member and the developer bearing member, based on a first information about a drive amount of the image bearing member and second information about a drive amount of the developer bearing member, in a case that an integrated value of the first information and the second information from initial installation or replacement of the developing device is greater than a predetermined value.