Abstract: An image forming apparatus includes a corona charger including a discharging wire and a grid electrode for charging a photosensitive drum at a charging position and an exposure device for exposing the drum charged by the charger at an exposure position which is at a downstream side of the charger (in a rotational direction of the drum) at the charging position. The grid electrode includes a first portion having openings and a second portion having only a non-opening portion in a charging region for charging the drum in a longitudinal direction of the charger, and the second portion includes a downstream side peripheral portion at a downstream end of the grid electrode with respect to the rotational direction. In a cross-section orthogonal to the longitudinal direction and including the charging region, the downstream side peripheral portion is intersected by a straight line passing through the exposure position and the wire.

Abstract: An exposure device forms an electrostatic latent image on a photoconductor drum. A charging device charges the photoconductor drum with a charging bias. A development roller holds toner with a development bias and attaches the toner to the electrostatic latent image. A toner image is obtained by attaching the toner to the electrostatic latent image and primarily transferred onto an intermediate transfer member. A determining unit primarily transfers to the intermediate transfer member non-image toner attached on the photoconductor drum while the charging bias and the development bias are increased before image forming and/or while the charging bias and the development bias are decreased after image forming, and determines an amount of the non-image toner on the basis of an output of a sensor. A managing unit determines a toner consumption amount or a toner residual amount with taking the determined amount of the non-image toner into account.

Abstract: A parameter detection unit detects a first factor parameter that corresponds to change in layer thickness of an organic photosensitive layer in a photoreceptor drum and a second factor parameter other than the first factor parameter. A discharge voltage applying unit and a grid voltage applying unit are controlled by a first charging control unit and a second charging control unit. The first charging control unit determines a charging current for a discharge wire of the discharge voltage applying unit in accordance with a detection value of the first factor parameter, which has been detected by the parameter detection unit. On the other hand, the second charging control unit determines an output voltage that corresponds to a grid electrode of the grid voltage applying unit in accordance with a detection value of the second factor parameter, which has been detected by the second charging control unit.

Abstract: A fixing device includes a heating body, a pressuring body, a heating source, a guiding part, a temperature sensing part and a charging part. The heating source supplies the heating body heat used for heating the medium. The guiding part guides the medium to a nip between the heating body and the pressuring body, at an upstream side from the nip in a conveying direction of the medium. The temperature sensing part senses a temperature of the heating body. The charging part electrically discharges to electrically charge the heating body with the same polarity as toner, at an opposite side to the guiding part across the temperature sensing part. The charging part includes a discharging electrode electrically discharging toward the heating body facing to the discharging electrode and an enclosure wall supporting the discharging electrode, enclosing the discharging electrode and producing an electric field in cooperation with the discharging electrode.

Abstract: A fixing device includes a fixing member, a pressing member, a charger, and adjusting part. The fixing member heats toner images on media. The pressing member forms nips with the fixing member and presses the media. The charger uses a corona discharge that occurs in an electric field generated around a discharging electrode so as to charge the fixing member to a same polarity of toner in the toner images. The adjusting part increases a bias applied to the discharging electrode in accordance with increase of a cumulative number calculated by accumulating a number of the media on which the toner images are fixed or increase of a cumulative printing amount calculated by multiplying a printing rate that indicates a ratio of an area of the toner images to an area of the media by the cumulative number.

Abstract: An image forming apparatus includes an image bearer, an image forming device to form a toner image on the image bearer with toner, a power source to output a bias to transfer the toner image onto a recording medium, and control circuitry. The circuitry controls the power source to decrease a peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when a time-averaged voltage of the bias is on a transfer side of transferring the toner to the recording medium, from a median value of maximum and minimum voltages of the bias. The circuitry controls the power source to increase the peak-to-peak voltage of the bias in response to increase in at least one of temperature and humidity, when the time-averaged voltage of the bias is on a return side of returning the toner to the image bearer, from the median value.

Abstract: An image forming apparatus includes the following elements. Plural developing units supply charged developers to electrostatic latent images formed on plural associated image carriers disposed along a direction in which an intermediate transfer body is transported. Plural first transfer units transfer the associated developers onto the intermediate transfer body when the intermediate transfer body passes the associated image carriers while being transported so as to superpose the developers on each other. A second transfer unit transfers the superposed developers transferred onto the intermediate transfer body by the plural first transfer units onto a recording medium. A charge-amount adjusting unit decreases an amount of electric charge of a developer which forms a lower layer developer among the superposed developers transferred onto the intermediate transfer body.

Abstract: A charger positioning adjuster, which is included in an image forming apparatus and disposed facing a charger uniformly charging a surface of an image carrier using corona discharging, includes a mounting part provided at a position on which the charger is detachably attached, a positioning member attached to the mounting part and positioning the charger by contacting thereto, and a spacer disposed between the mounting part and the positioning member and adjusting a distance between the surface of the image carrier and the charger.

Abstract: An image forming apparatus includes an image carrier whose surface is moved in a specific direction, a charging device to charge the image carrier, an exposure device to form an electrostatic latent image by exposing a surface of the charged image carrier, a developing device to supply a developer to the image carrier on which the electrostatic latent image is formed, a transfer device to transfer a developer image formed on the surface of the image carrier onto an image forming medium, and a dielectric member that extends from the charging device to the vicinity of the image carrier and is disposed between the charging device and the image carrier surface part exposed by the exposure device, in which the charging device, the exposure device, the developing device and the transfer device are sequentially arranged around the image carrier along the movement direction of the surface of the image carrier.

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: A grid electrode that is substantially thin-plate-shaped includes an opening section in which plural openings are formed and a frame section that surrounds the opening section. The grid electrode is curved along a short-side direction thereof and includes portions having different thicknesses, the portions being arranged in the short-side direction.

Abstract: A charging device for electrically charging a photosensitive member, includes: a discharging electrode; a casing provided with an opening; a grid provided at the opening; a sheet-shaped shutter; a moving portion; a connecting portion; a winding-up portion; an urging portion; a first supporting portion; a second supporting portion; and an operating portion. The winding-up portion is configured to wind up, when the shutter is closed, the shutter so that a surface of the shutter opposing the photosensitive member is an outermost surface. When movement of the shutter in the opening direction is completed, the operating portion is covered with the shutter. When the connecting portion is separated from the moving portion, a leading end portion of the shutter with respect to the closing direction is movable toward a downstream side of the operating portion with respect to the opening direction by a winding-up force by the urging portion.

Abstract: An image reading apparatus includes: a housing; a cover pivotable with respect to the housing about a first pivot axis extending in first directions that are opposite each other; a first electric component provided in the housing; a second electric component provided in the cover; and an electric wire configured to connect the first electric component and the second electric component to each other. The electric wire includes: a first extending portion retained by the cover and extending in the first directions; and a second extending portion movable relative to the cover and extending from the first extending portion toward the housing.

Abstract: Embodiments pertain to a novel imaging member, namely, an electrostatic latent image generating member, and methods for using the same, that can generate an electrostatic latent image through charge acceptance control and without the need for conventional post charging photodischarge, eliminating process steps and avoiding limitations in system speed due to the transit time of charge carriers after light exposure.

Abstract: An image forming apparatus includes: a photosensitive drum configured to rotate about a rotational axis extending in an axial direction; and a charger that charges the photosensitive drum. The charger includes: a wire electrode; a grid electrode having a grid surface that faces the photosensitive drum between the wire electrode and the photosensitive drum; and a pair of shield electrodes, which faces each other with interposing the wire electrode therebetween, and which extends in a substantially orthogonal direction to the grid electrode. The grid surface is inclined to a second plane such that the grid electrode and the shield electrode come close to the photosensitive drum at a more downstream side in a rotating direction of the photosensitive drum than a first plane, wherein the first plane includes the wire electrode and the rotational axis of the photosensitive drum, and the second plane is orthogonal to the first plane.

Abstract: A charging device includes a discharging electrode, grid electrode, pair of shielding electrodes, frame, airflow-generating electrode, and impurity-removing member. The discharging electrode produces a corona discharge to charge a surface of photosensitive member. A first voltage is applied to the grid electrode. The discharging electrode is positioned between the shielding electrodes. The frame includes a pair of side walls confronting with each other in the moving direction. The discharging electrode and the pair of shielding electrodes are positioned between the side walls. The airflow-generating electrode is disposed at a position opposite to the discharging electrode with respect to the grid electrode. The airflow-generating electrode is applied with a second voltage lower than the first voltage. The impurity-removing member is provided on an inner surface of the frame.

Abstract: An image forming apparatus has a latent image forming portion that includes a latent image supporting body, and a supporting member disposed at both ends of the latent image supporting body, a charging unit that includes a discharge electrode supplying electric charge to the latent image supporting body, and a control electrode controlling a potential of the latent image supporting body, a cleaning member that makes one end of the control electrode located at a stand-by position and is reciprocally moved so as to clean the control electrode, and a movement portion that moves the charging unit to a first position when charging the latent image supporting body, and moves the charging unit to a second position which is further spaced from the latent image forming portion than the first position when the control electrode is cleaned by the cleaning member.

Abstract: An image forming device, comprising: at least one photosensitive body; scorotron chargers that charge the at least one photosensitive body; a charge voltage applying circuit to which the scorotron chargers are commonly connected, the charge voltage applying circuit being configured to apply a voltage to the scorotron chargers; wires respectively provided for the scorotron chargers; grid electrodes respectively provided for the scorotron chargers; a current detection unit configured to detect a grid current of each of the grid electrodes; and a grid current control unit configured to execute a constant-current control for a maximum grid current which is a maximum of grid currents flowing through the grid electrodes so that the maximum grid current is kept at a first threshold larger than or equal to a reference value by adjusting an output of the charge voltage applying circuit.

Abstract: An electrophotographic imaging device includes a charging device, a cleaning device, and a fuser member that each include hydrophobic carbon nanotubes. The use of hydrophobic carbon nanotubes can increases the charging device's, the cleaning device's, and the fuser member's durability, conductivity, and contaminants deposition.

Abstract: An image forming apparatus of the present invention includes: a developing section which includes a developer bearing member which bears toner to be supplied to an image bearing member on which an electrostatic latent image is formed; and a developer regulating section which regulates a layer thickness of the toner borne by the developer bearing member, the developer regulating section being electrically connected to the charger case, the developer regulating section being at least partially electroconductive.

Abstract: To provide a structure in which, even when the space between a grid and a photosensitive member is narrowed so as to improve charging efficiency, wear of a shutter due to rubbing against the grid during movement of the shutter is suppressed. There is provided a mechanism that withdraws the grid to the discharge electrode side when the opening is covered with the shutter.

Abstract: A charging device includes a corona charger including a grid electrode, a cleaning member configured to clean the grid electrode, a sheet-type shutter configured to open/close an opening of the corona charger, a drive source configured to drive both the cleaning member and the shutter in a longitudinal direction of the corona charger, and a control unit configured to control drive of the drive source such that, when the shutter is moved in a closing direction of the opening of the corona charger after image formation is finished, the cleaning member and the shutter are driven at a first speed, and when the shutter is moved in an opening direction of the opening of the corona charger at least from when power is turned on until image formation is started, the cleaning member and the shutter are driven at a second speed higher than the first speed.

Abstract: An image forming apparatus includes an image carrier whose surface is moved in a specific direction, a charging device to charge the image carrier, an exposure device to form an electrostatic latent image by exposing a surface of the charged image carrier, a developing device to supply a developer to the image carrier on which the electrostatic latent image is formed, a transfer device to transfer a developer image formed on the surface of the image carrier onto an image forming medium, and a dielectric member that extends from the charging device to the vicinity of the image carrier and is disposed between the charging device and the image carrier surface part exposed by the exposure device, in which the charging device, the exposure device, the developing device and the transfer device are sequentially arranged around the image carrier along the movement direction of the surface of the image carrier.

Abstract: A charging and/or discharging unit for an image formation device may include a discharge wire extending in a lateral direction (a second direction) perpendicular to a first direction, the first direction corresponding to a moving direction of the surface of a photosensitive drum and parallel to the surface of the photosensitive drum. The discharge wire may be distanced from the surface of the photosensitive drum. Shield electrodes and a grid electrode are opposed to the discharge wire, with a distance therefrom and extending along the lateral direction. The shield electrodes and the grid electrode may include ribs extending in the lateral direction, respectively. In one or more examples, the ribs may correspond to recessed portions in a surface of the corresponding electrodes and may be located out of a specified circular area.

Abstract: An image forming apparatus includes a latent-image forming member including a latent-image carrier and support portions, a charging member including a discharge electrode and a control electrode, restraining portions that restrain both ends of the control electrode in a width direction, and abutting portions that are provided on the support portions, that include curved surfaces, and that are abutted against the control electrode. The curved surfaces have a center of curvature that coincides with a rotational center of the latent-image carrier, and are at a position where a distance from the latent-image carrier in a radial direction is equal to a distance between the latent-image carrier and the control electrode. When the charging member is attached to the latent-image forming member, the control electrode is abutted against the curved surfaces by the restraining portions and is deformed along the curved surfaces.

Abstract: An image forming apparatus includes: a first photosensitive member; a second photosensitive member; a third photosensitive member; a first scorotron-type charger that is configured to charge the first photosensitive member; a second scorotron-type charger that is configured to charge the second photosensitive member; a third scorotron-type charger that is configured to charge the third photosensitive member; a first voltage applying circuit, which is connected to the first scorotron-type charger, and which is configured to apply a voltage to the first scorotron-type charger; and a second voltage applying circuit, which is commonly connected to the second scorotron-type charger and the third scorotron-type charger, and which is configured to apply a voltage to the second scorotron-type charger and the third scorotron-type charger.

Abstract: An image forming apparatus includes an image carrier whose surface is moved in a specific direction, a charging device to charge the image carrier, an exposure device to form an electrostatic latent image by exposing a surface of the charged image carrier, a developing device to supply a developer to the image carrier on which the electrostatic latent image is formed, a transfer device to transfer a developer image formed on the surface of the image carrier onto an image forming medium, and a dielectric member that extends from the charging device to the vicinity of the image carrier and is disposed between the charging device and the image carrier surface part exposed by the exposure device, in which the charging device, the exposure device, the developing device and the transfer device are sequentially arranged around the image carrier along the movement direction of the surface of the image carrier.

Abstract: A charging device includes a discharging electrode, grid electrode, pair of shielding electrodes, frame, airflow-generating electrode, and impurity-removing member. The discharging electrode produces a corona discharge to charge a surface of photosensitive member. A first voltage is applied to the grid electrode. The discharging electrode is positioned between the shielding electrodes. The frame includes a pair of side walls confronting with each other in the moving direction. The discharging electrode and the pair of shielding electrodes are positioned between the side walls. The airflow-generating electrode is disposed at a position opposite to the discharging electrode with respect to the grid electrode. The airflow-generating electrode is applied with a second voltage lower than the first voltage. The impurity-removing member is provided on an inner surface of the frame.

Abstract: An image forming apparatus has a latent image forming portion that includes a latent image carrier having a cylindrical shape, and a supporting member disposed at both ends of the latent image carrier and rotatably supporting the latent image carrier, a charging unit that includes a discharge electrode supplying electric charge to the latent image carrier, and a grid electrode having a shape curved around the latent image carrier, a first supporting portion that supports the curved grid electrode from the latent image carrier side, a second supporting portion that supports the curved grid electrode from the discharge electrode side, and a pinching unit that pinches the grid electrode between the first supporting portion and the second supporting portion in a contact state.

Abstract: A charging device includes a discharge electrode that is attached to a base member and discharges electricity to supply an electric charge to a latent-image carrier that carries an electrostatic latent image, a control electrode that is located on the latent-image-carrier side of the discharge electrode attached to the base member, that is curved along the latent-image carrier, and that controls a potential of the latent-image carrier, a support member that is fixed to the base member by a fixing member and includes a curved support surface that supports both ends of the control electrode in a longitudinal direction at a side at which the discharge electrode is provided, and first and second pressing members that are provided at respective ends of the control electrode in the longitudinal direction and that press the control electrode against the support surface.

Abstract: A charging device includes a discharge electrode that extends along an axial direction of a member to be charged; and a potential control plate disposed between the member to be charged and the discharge electrode and curved along a peripheral surface of the member to be charged. The potential control plate includes three or more structural lines that are arranged in a circumferential direction of the member to be charged and that linearly extend along the axial direction, and connecting portions arranged in the axial direction, each connecting portion connecting two or more of the three or more structural lines to each other, the two or more structural lines being next to each other in the circumferential direction. The structural lines connected by one of the connecting portions and those connected by another one of the connecting portions are at least partly different from each other.

Abstract: A charged particle generator includes a first electrode, a second electrode, and an insulating material that is provided between the first electrode and the second electrode. Charged particles are generated by discharge that occurs between the first and the second electrodes. The first electrode, the insulating material, and the second electrode are arranged in a first direction. The second electrode has a shape that does not intersect a path along which the charged particles move in a second direction perpendicular to the first direction.

Abstract: A charging device for electrically charging a photosensitive member, includes: a discharging electrode; a casing provided with an opening; a grid provided at the opening; a sheet-shaped shutter; a moving portion; a connecting portion; a winding-up portion; an urging portion; a first supporting portion; a second supporting portion; and an operating portion. The winding-up portion is configured to wind up, when the shutter is closed, the shutter so that a surface of the shutter opposing the photosensitive member is an outermost surface. When movement of the shutter in the opening direction is completed, the operating portion is covered with the shutter. When the connecting portion is separated from the moving portion, a leading end portion of the shutter with respect to the closing direction is movable toward a downstream side of the operating portion with respect to the opening direction by a winding-up force by the urging portion.

Abstract: A coronode charging device that is photo-etched with titanium which slows the erosion rate of the coronode and thereby enhances uniformity over a larger number of copies.

Abstract: A charging device includes a charging member that charges an outer peripheral surface of a cylindrical image carrier; an electrode member that has the shape of a plate having a longitudinal direction in an axial direction of the image carrier and that is disposed above the charging member; an attachment member that has a curved surface which is curved along the outer peripheral surface of the image carrier, the electrode member being attached thereon; and a pushing member disposed between the electrode member and the image carrier, the pushing member pushing the electrode member toward the curved surface so that the electrode member is curved to follow the curved surface.

Abstract: A discharger includes a discharging member that faces a member to be charged and discharges electricity by applying voltage; and a grid member that is disposed between the discharging member and the member to be charged and regulates electric discharge from the discharging member. The grid member has holes with a predetermined shape and extending through the grid member from the discharging member toward the member to be charged, and has a first region with the holes arranged at a first inclination angle, a second region with the holes arranged at a second inclination angle, and a boundary between the first and second regions and extending in the extending direction of the discharging member. When the first region is symmetrically projected onto the second region with respect to the boundary, an arrangement pattern of the holes in the first region and an arrangement pattern of the holes in the second region are positionally displaced relative to each other.

Abstract: A charging device includes a discharge electrode that extends along a rotational axis direction of a member to be charged that rotates and has an arc-shaped outer peripheral surface, the discharge electrode being arranged to face the outer peripheral surface; a potential control plate arranged between the outer peripheral surface of the member to be charged and the discharge electrode and extending in the rotational axis direction of the member to be charged, the potential control plate being plastically deformed so as to independently maintain the shape of the potential control plate; and a support member that supports the potential control plate only at both end portions of the potential control plate in a long-side direction of the potential control plate.

Abstract: An image forming apparatus includes: a photoconductor; a charger configured to charge the photoconductor, the charger including a discharge wire and a grid; a voltage applying circuit configured to generate charge voltage and apply the charge voltage to the discharge wire of the charger; a grid-current detector configured to detect a grid current passing through the grid; a controller configured to control the voltage applying circuit on the basis of a detection value detected by the grid-current detector so that the grid current is constant; an abnormal-discharge detector configured to detect an abnormal discharge occurring in the charger; and a suppression resistor configured to suppress abnormal discharge energy. The suppression resistor includes a first terminal and a second terminal. The first terminal is connected to the grid. The second terminal is connected to at least one of the grid-current detector and the abnormal-discharge detector.

Abstract: A carrier removing apparatus, including: an electrode, having a plurality of openings through which a carrier passes, disposed to oppose an image carrier, and a power source to apply a voltage onto the electrode so as to separate the carrier on the image carrier from the image carrier, wherein the electrode has a surface along a surface of the image carrier.

Abstract: A cleaning device includes a cleaning member provided at a first side of a curved grid electrode plate that is curved in a short-side direction, the cleaning member being pressed against the curved grid electrode plate to clean the first side thereof; a receiving member provided at a second side of the curved grid electrode plate, the receiving member receiving a pressing load applied by the cleaning member; and a moving unit that moves the cleaning member and the receiving member in a long-side direction of the curved grid electrode plate. The cleaning member and the receiving member are formed such that a pressure based on the load that is applied to an end portion of the curved grid electrode plate in the short-side direction is higher than that applied to a central portion of the curved grid electrode plate in the short-side direction.

Abstract: A cleaning device includes a device body, a cleaning member, and a support member. The device body is moved in a longitudinal direction of a plate-like grid member of a charging device. The cleaning member is disposed in the device body and cleans a first face of the grid member while pressing against the first face when the device body is moved. The support member is provided in the device body and has a support surface that is in contact with and supports a second face opposite to the first face of the grid member pressed by the cleaning member. The support surface is in contact with a mesh portion and a non-mesh portion of the grid member.

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: 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 charging device has a corona charger including a grid, the corona charger being configured to charge a photosensitive member. The device also has a sheet-like shutter configured to open and close an opening of the corona charger in the longitudinal direction, a winding member configured to wind the shutter while holding one end of the shutter, a holding member configured to hold the other end of the shutter and move in the longitudinal direction of the opening, and a protective member configured to protect a portion of a surface of the shutter facing the grid, the portion being adjacent to the holding member.

Abstract: A scorotron charging device includes a titanium grid in order to achieve improved resistance to corona byproducts.

Abstract: A charging device includes a corona charger for electrically charging a photosensitive member; a sheet-like member for covering and uncovering an opening of the corona charger; a regulating member for regulating a shape of the sheet-like member so that the sheet-like member is convex toward the corona charger with respect to a circumferential direction of the photosensitive member; and a winding-up member, including a winding-up shaft around which the sheet-like member is to be wound up, for winding up the sheet-like member so that a surface of the sheet-like member opposing the corona charger is directed toward a winding-up center of the winding-up shaft when the sheet-like member is wound up by the winding-up shaft.

Abstract: A charging device includes a charging member that charges an outer peripheral surface of a cylindrical latent-image carrier; an electrode member including a curved portion that is formed by press working so as to extend along the outer peripheral surface of the latent-image carrier, the curved portion having an electrode to which a voltage is applied, the electrode being disposed between the charging member and the latent-image carrier; a cleaning member that is movable along the curved portion in an axial direction of the latent-image carrier and that cleans the electrode; and a receiving portion formed in the curved portion at a position outside the electrode, the receiving portion receiving the cleaning member to release a contact pressure between the curved portion and the cleaning member.

Abstract: A grid electrode that is substantially thin-plate-shaped includes an opening section in which plural openings are formed and a frame section that surrounds the opening section. The grid electrode is curved along a short-side direction thereof and includes portions having different thicknesses, the portions being arranged in the short-side direction.

Abstract: To provide a structure in which, even when the space between a grid and a photosensitive member is narrowed so as to improve charging efficiency, wear of a shutter due to rubbing against the grid during movement of the shutter is suppressed. There is provided a mechanism that withdraws the grid to the discharge electrode side when the opening is covered with the shutter.

Abstract: An image forming apparatus includes an image carrier whose surface is moved in a specific direction, a charging device to charge the image carrier, an exposure device to form an electrostatic latent image by exposing a surface of the charged image carrier in accordance with an image signal, a developing device to supply a developer to the surface of the image carrier on which the electrostatic latent image is formed, a transfer device to transfer a developer image formed on the surface of the image carrier onto an image forming medium, and a dielectric member that has a dielectric constant of 5 or less and is disposed near the image carrier and between the charging device and the exposure device, in which the charging device, the exposure device, the developing device and the transfer device are sequentially arranged around the image carrier along the movement direction of the surface of the image carrier.