Abstract: An image forming apparatus includes a transfer unit including a transfer nip portion, a fixing unit including a fixing nip portion, a suction belt conveyance unit arranged between the transfer unit and the fixing unit and conveying the sheet toward the fixing nip, a first casing, a second casing connected to the first casing and supporting the fixing unit, a first positioning portion, and, a second positioning portion. The first positioning portion is disposed in the first casing and performs positioning of the suction belt conveyance unit in a predetermined direction along a surface perpendicular to a width direction of the sheet. The second positioning portion is disposed in the second casing and performs positioning of the suction belt conveyance unit in the predetermined direction.

Abstract: An image forming apparatus includes an image forming unit configured to form an image by using a toner based on image data; a detector configured to detect the toner in the image forming unit; a mount portion to which a container containing the toner is mounted; and a controller configured to perform a supply control for supplying the toner from the container mounted to the mount portion, based on a detection result of the detector; determine a usage condition of the container mounted to the mount portion; determine an amount of the toner supplied from the container in the supply control, based on a determination result of the usage condition and the image data; cumulate the amount of the toner supplied from the container in the supply control; and determine a remaining amount of the toner in the container mounted to the mount, based on a cumulated amount.

Abstract: A developing apparatus includes a developing mechanism and a heating mechanism, and the heating mechanism includes a plurality of heating units. The plurality of heating units are provided above or below the developing mechanism, and each heating unit of the plurality of heating units is disposed independently.

Abstract: A heating member of a fixing unit is situated in a fixing portion, and a commercial power source applies an alternating-current voltage to the heating member so that the heating member heats a transfer medium held in the fixing portion. In a case of transferring the toner image from an image bearing member onto the transfer medium in a transfer portion, a control unit controls a transfer power source based on a result of a comparison between a frequency obtained from a first detection result input from a detection unit with a predetermined frequency range including the frequency of the alternating-current voltage.

Abstract: An image forming apparatus includes a detecting unit detecting a value of a current flowing to a photosensitive member when a voltage is supplied to a voltage applying member or a value of a voltage applied to the photosensitive member when a current is supplied to the voltage applying member, an acquiring unit acquiring information concerning a difference between potentials of the unexposed portion and the exposed portion, based on detection results of the detecting unit at times when the voltage is applied by the voltage applying member to each of an unexposed portion formed in a region chargeable by a charging member in a rotation axis direction of the photosensitive member and an exposed portion formed in a region exposable by the exposure device in the rotation axis direction of the photosensitive member, and a control unit controlling an image forming condition based on the information concerning the difference.

Abstract: An image forming apparatus includes an intermediate transferor, a plurality of image bearers, a plurality of developing devices, a plurality of developer containers, a plurality of conveyance paths, and a plurality of sub-hoppers. At least one set of an image bearer, a developing device, and a sub-hopper is disposed at a height different from other sets. The arrangement of the plurality of developing devices and the plurality of sub-hoppers in the rotation direction of the intermediate transferor is changed while satisfying the following. The arrangement of the plurality of developer containers is not changed and the connections between the plurality of developing devices and the plurality of sub-hoppers are not change, while the layout of the plurality of tubes as the plurality of conveyance paths is changed so that the connections between the plurality of tubes and the plurality of sub-hoppers are not changed.

Abstract: An intermediate transfer member includes a resin substrate layer and a surface layer containing a cured product of a composition including a specific polyfunctional (meth)acrylic monomer and a specific fine particle of metal oxide.

Abstract: The present invention performs inplane uneven density correction that suppresses a number of tone correction properties and has few correction residuals. Accordingly, a correction unit corrects pixel data D based on a plurality of tone correction properties respectively corresponding to a plurality of spot diameters of a light to expose on a surface of a photoreceptor, and to generate a plurality of pieces of correction data D1 and D2. A setting unit sets a ratio Rb based on a spot diameter on the photoreceptor of a pixel corresponding to the pixel data D. A blending unit generates tone correction data Dc by blending the plurality of pieces of correction data D1 and D2 based on the ratio Rb.

Abstract: The present invention provides an image forming apparatus including: a first moving member pressed and moved by an openable/closable member when the openable/closable member is opened, and switching a cartridge from a state where the cartridge is positioned in an image forming position to a state where the positioning is released; and a second moving member pressed and moved by the openable/closable member when the openable/closable member is opened, and moving the exposure member from an exposure position to a retracted position, wherein when the positioning of the cartridge is released, a reaction force applied from the first moving member to the openable/closable member reaches a first peak, when the exposure member is moved to the retracted position, a reaction force applied from the second moving member to the openable/closable member reaches a second peak, and timing of the first peak is different from timing of the second peak.

Abstract: An image forming apparatus includes an transfer section including a transfer roller and a rotatable member and performing transfer processing in which it transfers a developer to a recording medium; a power source controller that applies a voltage to the transfer roller and measures a current value of a current that flows through the transfer roller and the rotatable member; and a main controller that calculates a first electrical resistance value between the transfer roller and the rotatable member in if the recording medium is absent between the transfer roller and the rotatable member and a second electrical resistance value between the transfer roller and the rotatable member if the recording medium is present between the transfer roller and the rotatable member on the basis of the current value measured by the power source controller, and determines a transfer voltage value for the transfer processing.

Abstract: A CPU of a printing apparatus selects one of a plurality of setting permission information items based on sheet property information in a case in which printing processing is performed employing a specific sheet type. Subsequently, the CPU of the printing apparatus performs a setting regarding each of a plurality of printing setting items so as to obtain a setting permitted in the selected setting permission information item in a case in which printing processing is performed employing a specific sheet type. Thus, a printing apparatus capable of executing the printing settings of a plurality of printing setting items appropriately is provided.

Abstract: An image forming apparatus is provided in which, during a continuous sheet passing, in the case where a between-sheets time is short, none of a cleaning mode and a drive OFF mode is performed; in the case where the between-sheets time is of a medium length of time, the cleaning mode is performed but the drive OFF mode is not performed; and in the case where the between-sheets time is long, both the cleaning mode and the drive OFF mode are performed. As a result, degradation of an image bearer due to the cleaning bias is alleviated, decreased productivity due to the cleaning mode is alleviated, a problem is alleviated in which a back surface of a recording medium gets dirty due to toner adhered to a transfer rotation body, and another problem is alleviated in which the service life of a driven member is shortened.

Abstract: An image forming apparatus includes an image forming section, a fixing device, a sheet conveyance path, a conveyance guide member, a blower, and a control section. The conveyance guide member constitutes one of a pair of sheet conveyance surface portions of the sheet conveyance path. The blower is disposed on an opposite side of the sheet conveyance surface portion constituted by the conveyance guide member to the sheet conveyance path and blows air at a sheet passing through the sheet conveyance path. A ventilation port and an air passage recess are located in the sheet conveyance surface portion constituted by the conveyance guide member. The ventilation port allows air from the blower to flow into the sheet conveyance path. The air passage recess extends in a sheet width direction. The air passage recess allows air that has passed through the ventilation port to flow through the air passage recess.

Abstract: An image forming apparatus includes a driving device, a transfer body, a toner detector, an error notification device, and a controller. The toner detector detects, at a preparation running and while the driving device drives a latent image bearer, one of a toner adhesion amount at a background portion of the latent image bearer and a toner adhesion amount at a background corresponding region of a transfer body. The error notification device notifies a user of an error with the toner adhesion being equal to or greater than a predetermined threshold value. The driving device stops only a developer bearer after driving both the latent image bearer and the developer bearer at the preparation running, but before a trailing edge of a detection target region of one of the background portion of the latent image bearer and the background corresponding region advances to an opposite position to the toner detector.

Abstract: A method of thermally developing an image from a latent image recorded in an image formation layer of a photothermgraphic imaging media. The method includes heating the imaging media to a development temperature as the imaging media is transported along a surface of a first heated drum, the first heated drum having a diameter providing the imaging media with a radius of curvature that provides the imaging media with cross-web stiffness sufficient to prevent wrinkling of the imaging media when being heated to the development temperature. The method further includes maintaining the imaging media at the development temperature for a first portion of a development duration of the imaging media, transferring the imaging media to at least one second heated drum at the development temperature, and maintaining the imaging media at the development temperature for a remaining portion of the development duration as the imaging media is transported along a surface of the at least one second heated drum.

Abstract: An image forming apparatus includes an image forming unit that forms a toner image on a transported medium using a developer containing toner and non-volatile oil, a heating unit that is arranged on a downstream of the image forming unit in a transport direction of the medium and heats the toner image on the medium to a melting temperature of the toner or higher, and a fixing unit that is arranged on a downstream of the heating unit in the transport direction, wherein the fixing unit includes a heat supply section that supplies heat to the developer on the medium, a removal section that removes the non-volatile oil from the developer to which heat is supplied by the heat supply section, and a fixing section that fixes the toner image, which is formed of the developer from which the non-volatile oil is removed by the removal section, on the medium.

Abstract: A recording apparatus has a pair of bearings 38 having: two surfaces 38a and 38b which support both edge portions of a conveying roller 40; driven rollers 42 which press the conveying roller 40 in the direction where extension lines of the two surfaces 38a and 38b cross; and further, an intermediate bearing 47 which presses the conveying roller 40 in the direction of a point where the extension lines of the two surfaces 38a and 38b cross.

Abstract: An inkjet offset printer includes an image receiving drum assembly having a hollow drum with an external surface and an internal surface defining an internal cavity. A heating and a cooling system located in the internal cavity provides distributed heating and cooling to the internal surface of the drum. Heating and cooling can be provided to individual regions of the internal drum surface to maintain a substantially uniform external drum surface temperature.

Abstract: A printing device includes a developer for developing a latent image with toner particles; an imaging plate comprising a plurality of pixel plates; and a plurality of voltage generators connected respectively to the pixel plates. The voltage generators positively bias selected pixel plates to form a latent image that is developed with toner from the developer. Another printing device includes a developer for developing a latent image with toner particles; an imaging plate comprising a plurality of pixel plates for selectively receiving toner particles from the developer; a plurality of voltage generators for biasing respective to pixel plates; and a background grid in the imaging plate for preventing toner particles from being deposited in areas between the pixel plates, wherein the background grid is connected to a voltage generator for applying a range of biases, positive and negative to the background grid.

Abstract: A developer cartridge provided in an image-forming device has a developer side casing that includes a toner-accommodating chamber and a developing chamber; and a plate wall disposed in the developing chamber for partitioning a thickness-regulating blade from the toner-accommodating chamber. When a thickness-regulating blade scrapes excess charged toner off the developing roller, the plate wall prevents this charged toner from returning to the toner-accommodating chamber. A flexible wiper for cleaning toner detection windows is attached to an agitator for stirring toner in the toner-accommodating chamber via a fixing member. The fixing member includes a support plate and a gripping plate disposed opposite each other with a slit formed therebetween. The wiper is inserted into the slit and is fixed to the fixing member when a boss protruding from a restricting plate becomes inserted into a through-hole formed in the wiper.

Abstract: An image forming apparatus includes a main body storage part, a determination part, and an initial adjustment part. The first image forming unit includes a first storage part storing first information indicative of whether or not an initial adjustment of the first image forming unit has been completed. The determination part determines whether or not the first information stored in the first storage part and the second information stored in the main body storage part satisfy respective prescribed conditions. The initial adjustment part causes the first and second image forming units to perform the initial adjustment when the first information indicates that the initial adjustment of the first image forming unit has not been completed and the second information indicates that the second image forming unit corresponds to an unused state.

Abstract: An electronic apparatus includes a main body; a maintenance member operated by an operator for maintenance; and a hand touch member disposed on the maintenance member. The hand touch member is formed of a conductive material, and is connected to a ground portion disposed in the main body.

Abstract: Consumable reduction is achieved for a printing device by utilizing a processor (32), memory (34) and software for receiving input information representative of an image to be printed and generating output information representative of a reduced consumable image in response to consumable smear, spatial relationship between adjacent dots and an image quality degradation. Factors such as print medium characteristics, heat or humidity and composure of the consumable are considered in performing the consumable reduction.

Abstract: A container includes: a container body that is to be inserted into the device, and that has a port; and a pair of support members arranged so that the support members face each other across the port, that supports a cover for covering the port, the cover including: a covering portion that covers the port; a pair of supported members that are supported by the support members; and a pair of connecting portions arranged so that the connecting portions face each other, that connects the covering portion and the supported members, and at least one of the connecting members being configured so that the connecting member becomes narrow as an outside surface of the connecting member tapers towards its inside surface at an end of the container body inserted into the device.

Abstract: In a copier having an image data converter that sets the C density, the M density and the Y density to a density obtained by multiplying the density of black in the RGB system by a CMY mixture ratio and sets the K density to a density obtained by multiplying the density of black by a K mixture ratio when black in the RGB system is converted into the CMYK system, the image data converter sets the K mixture ratio to a K reference mixture ratio when TK<PHK, and sets the K mixture ratio to a K high mixture ratio that is higher than the K reference mixture ratio when TK?PHK. Here, TK is a K toner amount of consumption insufficiency which is a K toner amount to be consumed to prevent toner deterioration at the driving amount of the developing unit, and PHK is a K high predetermined value.

Abstract: A developer cartridge provided in an image-forming device has a developer side casing that includes a toner-accommodating chamber and a developing chamber; and a plate wall disposed in the developing chamber for partitioning a thickness-regulating blade from the toner-accommodating chamber. When a thickness-regulating blade scrapes excess charged toner off the developing roller, the plate wall prevents this charged toner from returning to the toner-accommodating chamber. A flexible wiper for cleaning toner detection windows is attached to an agitator for stirring toner in the toner-accommodating chamber via a fixing member. The fixing member includes a support plate and a gripping plate disposed opposite each other with a slit formed therebetween. The wiper is inserted into the slit and is fixed to the fixing member when a boss protruding from a restricting plate becomes inserted into a through-hole formed in the wiper.

Abstract: An image forming apparatus, which reduces toner spatter and produces a good quality image when forming a toner image using the direct recording method. An image forming part includes: a toner carrier for carrying toner; and toner controlling means, which is disposed between the toner carrier and recording paper on which the toner is made to adhere, and which has a plurality of toner passage holes, the toner controlling means having a control electrode for controlling the passage of toner on the toner carrier side surface in the area around the toner passage hole, and forming a toner image by causing the toner to fly to the recording paper, and the image forming apparatus having liquid applying/humidifying means for either applying a liquid to or humidifying the imaging surface of the recording paper prior to forming a toner image.

Abstract: A direct image-recording device in which a predetermined gap set between an image carrier and a hole forming member can be maintained, and an image forming apparatus provided with the direct image-recording device.

Abstract: Provided are a toner supply roller and an image forming apparatus using the toner supply roller. The image forming apparatus employs a direct image developing technique, and includes the toner supply roller having a plurality of electrodes formed on an outer surface thereof to selectively supply toner to an image forming unit.

Abstract: Imaging methods and imaging devices are described according to some aspects. According to one aspect, an imaging method includes defining a plurality of first portions of a layer of a marking agent corresponding to an image to be formed, removing the second portions of the marking agent after the defining, increasing a charge density of the first portions of the marking agent after the removing, and transferring the first portions of the marking agent after the increasing.

Abstract: An electrostatic latent image is formed by controlling the amount of light, the emission time, and the like, considering the spot diameters of a laser, without changing the charging bias, the developing bias, and the like so as to obtain a plurality of correlations between density patches and development contrasts faithfully representing the developing characteristics of an image forming apparatus in a short time.

Abstract: A method and system for monitoring a print drum maintenance system of an image producing machine is disclosed herein in various embodiments. A test pattern is printed on the print drum, and imaged with an image-on-drum detector to determine a printed pattern response. The print drum is then cleaned again imaged with the image-on-drum detector to determine a cleaned print drum response. A cleaning efficiency is computed by comparing the imaged test pattern response to the imaged cleaned print drum response and determining if a failure condition exists by comparing the computed cleaning efficiency to predetermined limits. A corrective process is performed if the failure condition does exist, the corrective process including changing parameters of the drum maintenance system according to the computed cleaning efficiency. The changed parameters are compared to predetermined thresholds and, if not exceeding the thresholds, the cleaning is repeated after the parameters are changed.

Abstract: A toner supply arrangement for use in an integrated printing system which includes at least one toner container wherein the at least one toner container adapted for supplying toner to at least two image marking engines. The arrangement further includes a distribution mechanism adapted to transport the toner from the at least one toner container to the at least two image marking engines.

Abstract: Systems and methods of a multiple dispensing system may include an image carrier, and may include a plurality of substantially aligned developing units positioned to develop image information on the image carrier. Each developing unit may include only one ink container and only one developer housing. The systems and method may also include a first dispensing system positioned upstream in a sheet feed direction of the plurality of substantially aligned developing units. The first dispensing system may include a first ink container and a first developer housing. The first developer housing may be configured to receive first imaging media from the first ink container and second imaging media from at least one other ink supply source.

Abstract: A printing device includes a developer for developing a latent image with toner particles; an imaging plate comprising a plurality of pixel plates; and a plurality of voltage generators connected respectively to the pixel plates. The voltage generators positively bias selected pixel plates to form a latent image that is developed with toner from the developer. Another printing device includes a developer for developing a latent image with toner particles; an imaging plate comprising a plurality of pixel plates for selectively receiving toner particles from the developer; a plurality of voltage generators for biasing respective to pixel plates; and a background grid in the imaging plate for preventing toner particles from being deposited in areas between the pixel plates, wherein the background grid is connected to a voltage generator for applying a range of biases, positive and negative to the background grid.

Abstract: A thermal developing apparatus for thermally developing a latent image formed on a thermal developing recording material by a thermal developing portion, the apparatus comprising: a heating unit that heats the thermal developing recording material carried to the thermal developing portion, the heating unit comprising a plurality of heating portions that are aligned in a direction that intersects orthogonally with a carrying direction of the thermal developing recording material; and a plurality of temperature measuring portions that measure temperatures of the plurality of heating portions respectively, each of said plurality of temperature measuring portions being arranged to measure a center portion of a temperature distribution in each of said plurality of heating portions.

Abstract: A thermal processor for thermally developing an image in an imaging material. The processor includes an oven, at least one rotatable member positioned within oven, and a sleeve adapted to slideably fit over and selectively couple to at least a portion of the rotatable member. The sleeve has an exterior surface coated with a layer of polymer material and is positioned such that the layer of polymer material contacts and transports the imaging material through the oven as the at least one rotatable member rotates.

Abstract: Image development methods, hard imaging devices, and image members are described. According to one embodiment, an image development method includes providing an image member comprising a surface having different portions of different electrical conductivities, wherein one of the portions defines an imaging pattern of an image, providing a development agent comprising a plurality of electrically charged image particles and a plurality of electrically charged charge directors over the image member, providing an electrical field proximate the image member having the development agent over the image member, and using the electrically charged charge directors and the electric field, directing the electrically charged image particles to the one of the portions of the surface of the image member to develop the image.

Abstract: This heat developing method includes a step of forming a latent image on a heat developing photosensitive film sheet and a step of developing the film sheet, while the film sheet on which a latent image is formed is being conveyed, by heating with segmented heaters which are formed by dividing the total heating area into plural segments in the direction perpendicular to the conveyance direction, and which are independently temperature controllable, wherein the film sheet is so conveyed that no film sheets of different sizes are simultaneously in contact with any segmented heater.

Abstract: An image forming apparatus, includes: a developer which is attachable to and detachable from an apparatus main body and which holds toner; an image forming section which forms a toner image using the toner held inside the developer; and a controller which executes a density control operation of forming a patch image using the toner held inside the developer and controlling an image forming condition for the image forming section based on a density detection result of the patch image, wherein the developer includes a memory which stores specific information regarding an attribute which is specific to the developer, and the controller determines a mode of the density control operation based on the specific information read out from the memory.

Abstract: Provided is an intermediate transfer member, a method of producing the same, and an image forming method and an image forming apparatus thereof having excellent effects such that neither crack nor rupture is generated upon repetitive use, no transferring ratio drops during secondary transfer, and neither white patch of an text image nor white patch of a solid image is generated. Also disclosed is an intermediate transfer member used for an image forming apparatus, wherein a surface of the intermediate transfer member has a hardness of 1.5-3.0 GPa, measured by a nano indentation method, and a hardness of 0.15-0.45 GPa, specified by a universal hardness method.

Abstract: A thermal development apparatus is provided with: a thermal development section for heating a photosensitive thermal developable recording material to elicit a latent image recorded on an image-forming layer on both faces of the photosensitive thermal developable recording material by a heating unit, a cassette holder section for holding a cassette that houses the photosensitive thermal developable recording material therein, a conveyor unit for taking the photosensitive thermal developable recording material out of the cassette held in the cassette holder section and conveying the photosensitive thermal developable recording material to the thermal development section, and a control unit for controlling at least one of a heating temperature and a conveyance speed in the heating unit in the thermal development section, wherein the control unit is provided with a moisture correction information of the photosensitive thermal developable recording material and the control unit suitably corrects and controls the

Abstract: A photo-thermographic recording apparatus, comprises a film loading device capable of loading a sheet type photo-thermographic film, a conveyance device for conveying the photo-thermographic film from the film loading device, an exposing device for forming a latent image corresponding to an image signal onto the sheet type photo-thermographic film conveyed by the conveyance device, and a thermal developing device for visualizing the latent image formed onto the sheet type photo-thermographic film while heating the sheet type photo-thermographic, the thermal developing device including a heating device therein and a plurality of opposed rollers arranged opposite to the heating device so as to press the sheet type photo-thermographic film onto the thermal developing device, herein the plurality of opposed rollers is structured so that a foreign matter originating from an edge portion of the sheet type photo-thermographic film does not affect an image formed on the sheet type photo-thermographic film.

Abstract: A thermal developing equipment including a conveying unit for conveying a sheet-like photosensitive material and a heating unit for thermally treating a latent image formed on an image forming layer of the photosensitive material to be conveyed by the conveying unit, thereby visualizing it, wherein the heating unit is divided into plural regions which can be independently temperature controlled in the width direction of the photosensitive material perpendicular to the conveying direction of the photosensitive material; plural position detection sensors aligned along the width direction of the photosensitive material are provided in the upstream side of the heating unit; and a temperature control unit for controlling the temperature of the heating unit controls the temperature of each of the regions of the heating unit corresponding to an output of the position detection sensor.

Abstract: A heating control method of a heat development recording device includes a heating step in which after start-up of the heat development recording device, a heat development section is heated to a target temperature by a plate heater, a temperature holding step in which after the temperature of the plate heater has reached the target temperature, the target temperature is held for a prescribed time, and a step in which after the target temperature has been held for the prescribed time, the heat development section is set up in the recordable state, wherein after start-up of the heat development recording device, operation history information from the time of the last start-up is collected; and after reaching the target temperature at the time of the present start-up, a temperature holding time is determined depending upon the operation history information.

Abstract: A heat development apparatus for heat developing a heat-developable recording material from one surface side by a heating unit, while transporting the heat-developable recording material by a transportation unit, the apparatus comprising: an inversion processing mechanism for inverting the heat-developable recording material discharged from a heating region in which the heat developing is made by the heating unit, and returning it to the heating region; and a transportation route switching unit for selectively switching a route of the heat-developable recording material discharged from the heating region to a side of the inversion processing mechanism or a discharge-side transportation route.

Abstract: An image forming apparatus includes a plurality of removable developing units each of which has an image carrier whose width is narrower than a width of a printable area of the printing paper, and a driving unit for driving the plurality of the removable developing units. The plurality of the removable developing units are disposed in different rows parallel to a main scanning direction such that one end of an image producing area of an image carrier of a first developing unit coincides with one end of an image producing area of an image carrier of a second developing unit adjoining to the first developing unit. The image forming apparatus further includes a control unit for supplying printing data to the plurality of the removable developing units in timings shifted form row to row.

Abstract: When a new process cartridge is detected, that new process cartridge is initialized. A flag that indicates initialization status of the new process cartridge is set and stored. When a new process cartridge is detected, the flag is set to indicate non-initialization, the flag is maintained in that status during the initialization of the new process cartridge is being performed by the initialization unit, and the flag is set to indicate initialization completion when the initialization of the process cartridge is completed normally.

Abstract: A image forming apparatus includes a photosensitive body as an image bearing member having a surface layer. The surface layer includes a charge transport layer having the thickness from 10 ?m to 20 ?m. An exposing unit exposes the surface layer to the light to form latent image, and has a resolution greater than 600 dpi. A developing unit develops the latent image with toner so that a toner layer is formed on the photosensitive body. The toner layer formed on the photosensitive body includes two or three layers of toner particles. The electric charge Q (?C/g) of the toner layer per unit weight, the average thickness t (?m) of the toner layer, and the gap d (?m) between the smallest dots satisfy the following relationship: 50.4/d?|Q/t|?10.0.

Abstract: Electron generating devices and LED arrays are arranged in a surrounding area of a photosensitive drum. The electron generating devices are located downstream of a cleaner and upstream of a developing unit with respect to a turning direction of the photosensitive drum with a specific gap between the electron generating devices and a surface of the photosensitive drum. The LED arrays are disposed against outer ends of the electron generating devices opposite to inner ends thereof facing the photosensitive drum. When activated by a driving circuit according to image information, individual LED elements of the LED arrays emit light, causing the electron generating devices to emit electrons in a pattern corresponding to the image information. The electrons emitted from the electron generating devices produce more electrons due to an electron avalanche phenomenon before reaching the photosensitive drum, eventually forming an electrostatic latent image on the surface of the photosensitive drum.