Abstract: A region of an image bearing member that comes into contact with a recording material at a nip in a state in which the recording material is held by the nip is a first region, and a region of the image bearing member that does not come into contact with the recording material at the nip in a state in which the recording material is not held by the nip is a second region. A controller controls to apply a first developing voltage to a developer bearing member when the first region in which a first surface potential has been formed faces a developer bearing member and apply a second developing voltage lower than an absolute value of the first developing voltage to the developer bearing member when the second region in which a second surface potential has been formed faces the developer bearing member.

Abstract: A developing device includes a housing, a developing roller, and a blade. The housing includes a developer chamber and an opening. The developing roller is disposed in the developer chamber, such that a part of the developing roller in a rotational direction thereof is exposed to an outside of the opening. The developer roller includes a sleeve rotatable around a shaft and a magnetic element. The magnetic element has a magnetic polarity opposite to that of a developer and is disposed at an entrance rotational position of the developer roller at which a sleeve region of the sleeve goes into the developer chamber from the outside of the opening. The blade is positioned near a surface of the sleeve to regulate a thickness of the developer on the surface of the sleeve. The thickness of the developer regulated on the sleeve region at the entrance rotational position by the blade is equal to or greater than 0.6 mm and equal to or less than 1.4 mm.

Abstract: An image forming apparatus includes an image carrier for carrying an electrostatic latent image, a developer carrier for developing the electrostatic latent image of the image carrier with a developer, a developer regulating member that regulates a thickness of a layer of the developer held by the developer carrier, and a supply member that supplies the developer to the developer carrier. An absolute value of a voltage applied to the developer regulating member is larger than an absolute value of a voltage applied to the supply member.

Abstract: A developing unit includes a developer bearer to bear developer on a surface thereof, first and second developer conveyors each having a spiral blade mounted on a rotary shaft thereof parallel to a rotary axis of the developer bearer to convey developer in opposite directions to each other. A developer drain hole is provided at a given height in a side wall of a second developer conveyance channel to face a communication opening across the second developer conveyor. The first developer conveyor rotates in a direction with its spiral blade rising between the rotary shaft of the first developer conveyor and the communication opening. Rotational phases of the first developer conveyor and the second developer conveyor are fixed and synchronized with each other to weaken momentum of developer flow generated by the first developer conveyor toward the developer drain hole via the second developer conveyor.

Abstract: A development apparatus includes a developer carrier to develop an electrostatic latent image using a developer, a first and second developer supply members each to supply the developer to the developer carrier. Hs1, ?1, t1, Hs2, ?2, and t2 satisfy a following formula below, 10?Hs1×(?1/t1)+Hs2×(?2/t2)?50 Herein, Hs1 is a hardness of the outer peripheral surface of the first developer supply member, t1 is a layer thickness of an elastic layer of the first developer supply member, ?1 is an NIP amount that is determined when the first developer supply member is in press-contact with the developer carrier, Hs2 is a hardness of the outer peripheral surface of the second developer supply member, t2 is a layer thickness of an elastic layer of the second developer supply member, and ?2 is an NIP amount that is determined when the second developer supply member is in press-contact with the developer carrier.

Abstract: An image forming apparatus includes a main body; at least one developer including an image carrier unit having an image carrier and a charged body charging the image carrier, a developing unit installed to swing at a predetermined angle with respect to the image carrier unit and having a developing roller, and a pressing member pressing the developing unit so that the developing roller comes in contact with the image carrier, and separably installed in the main body; a nip separation unit installed in the main body on one side of the developer to swing the developing unit so that the developing unit is in a position that is separated from the image carrier; and a control unit controlling the developer and the nip separation unit according to a print command.

Abstract: According to one embodiment, a method for erasing an image includes erasing an image formed using a toner containing at least a binder resin, an electron donating color developable agent, and an electron accepting color developing agent by heating for 10 seconds or less. A color difference ?E between a region where the image is erased and a paper is 5 or less.

Abstract: An image forming apparatus includes: an image carrier; a latent-image forming device; a developing device; a latent-image forming device contacting/separating mechanism; and a developing device contacting/separating mechanism, and the latent-image forming device contacting/separating mechanism allows the latent-image forming device to be movable to the latent-image forming device contacting position in a state where the developing device is moved to the developing device contacting position.

Abstract: An image forming method, includes a charging step of charging an image carrier; an image writing step of writing image data onto the image carrier; a developing step of developing a latent image area written by the image writing step on the image carrier; a transferring step of transferring a toner image developed by the developing step to a transferring member; an image writing position adjusting step of detecting a position of the image carrier where the image is written in a case where designated conditions are satisfied, and of adjusting an image writing position; and a voltage output control step of controlling voltages applied for charging, developing, and transferring in the charging step, the developing step, and the transferring step, respectively.

Abstract: A cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes an image bearing member; a frame; process means contactable to and actable on the image bearing member; a covering member detachably mounted to the frame to protect a surface of the image bearing member; and a spacing portion provided on the covering member and inserted between the image bearing member and the process means to space the image bearing member and the process means from each other, the spacing portion being movable relative to the covering member while being interposed between the image bearing member and the process means when the covering member is removed from the frame.

Abstract: An image forming apparatus includes: an image carrier; a latent-image forming device; a developing device; a latent-image forming device contacting/separating mechanism; and a developing device contacting/separating mechanism, and the latent-image forming device contacting/separating mechanism allows the latent-image forming device to be movable to the latent-image forming device contacting position in a state where the developing device is moved to the developing device contacting position.

Abstract: An image forming unit includes an image supporting member; a developer supporting member for attaching developer to a static latent image formed on the image supporting member to form a developer image; and a protective sheet disposed between the image supporting member and the developer supporting member when the image forming unit is stored. The protective sheet has a surface resistivity between 1.0×108?/? and 8.0×1012?/? when a voltage between 10 V and 250 V is applied thereto.

Abstract: An electrophotographic image forming apparatus detachably mountable to a main assembly of the apparatus, includes a rotatable image bearing member on which a latent image is to be formed; charging means for contacting said image bearing member to charge a surface of said image bearing member; a frame supporting said image bearing member and said charging means; a covering member, demountably mounted to said frame, for protecting the surface of said image bearing member; and a spacer member including a spacing portion, movably provided on said covering member, for entering between said image bearing member and said charging means to space them therebetween, and a retaining portion, contacting said covering member when said spacing portion is not between said image bearing member and said charging means, for preventing said spacer member from disengaging from said covering member.

Abstract: A housing of a developing apparatus is provided with a conveying member in a developer supplying and recovering portion, and two agitating members rotating in the same direction respectively as viewing rotating shafts from a near side in an axial direction, in a developer agitating portion. A guide is provided in an inner bottom surface of the housing between two agitating members. A braking portion suppressing a discharge of a developer is provided in a downstream side of the developer agitating portion in a developer conveying direction of the second agitating member, and a discharge portion is provided in a downstream side of a disc of the braking portion.

Abstract: An image forming unit includes an image supporting member; a developer supporting member for attaching developer to a static latent image formed on the image supporting member to form a developer image; and a protective sheet disposed between the image supporting member and the developer supporting member when the image forming unit is stored. The protective sheet has a surface resistivity between 1.0×108?/? and 8.0×1012?/? when a voltage between 10 V and 250 V is applied thereto.

Abstract: An image forming apparatus and a method of detecting a home position error are provided. The image forming apparatus includes a plurality of developing units, a cam shaft, and a plurality of cams that are formed on the cam shaft to correspond to the respective developing units. A power transmitting element is installed between the plurality of developing units and the plurality of cams and selectively transmits a rotational force of a driving source to the plurality of developing units according to a rotational phase of the cam shaft. An indicating element is installed on the cam shaft and includes a plurality of indicating units. A sensor senses the plurality of indicating units. A home position error is detected each time when the indicating units pass through the sensor.

Abstract: In a device and method for inking of a charge image with toner material in a printer or copier, the charge image corresponding to a print image to be generated is generated on a surface of a photoconductor element comprising a photoconductive layer. At least one layer made up of toner particles is applied on a region of a surface of an applicator element. The surface of the photoconductor element is contacted by at least one part of the toner particles applied on the surface of the applicator element.

Abstract: A developing device which can stably supply a developer to a latent image carrier by preventing the scattered developer from being discharged and thereby preventing the developer from being discharged despite that the amount of developer within the developing device does not increase, and an image forming apparatus using the developing device. A block member serving as a scattered developer discharge prevention member is provided so as to block a path through which the developer scattered as a result of a conveyance operation of a supply screw serving as a developer conveying member moves toward a developer discharge port. Accordingly, the scattered developer is prevented from reaching the developer discharge port and being discharged therefrom.

Abstract: A developing device includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with a developer, wherein an oscillating electric field is formed between the developer carrying member and the image bearing member; a jumping developer blocking member, provided between the image bearing member and the developer carrying member, for blocking a part of a region in which the developer jumps from the developer carrying member to the image bearing member, the jumping developer blocking member including an insulative portion and an electrically floating electroconductive portion opposed to the developer carrying member.

Abstract: An image forming apparatus includes a main body; a photosensitive member on which a latent image is formed; a cartridge detachably attached to the main body and accommodates a developing agent therein; a developing roller provided at the cartridge, the developing roller being movable between a first position where the latent image is developed and a second position where development is not performed; a support shaft that rotatably supports the developing roller; and a separation member that moves the developing roller from the first position to the second position by engagement with the support shaft.

Abstract: A developing apparatus having a resilient developing roller for developing an image with a single-component toner includes a contacting mechanism for moving the developing roller into contact with a surface of an image carrier for developing the image and moving the developing roller in a forward direction at substantially the same speed as the image carrier. The width of a developing nip and a depth of bite between the image carrier and developing roller is set such that the traveling speed of the local portion of the developing roller that contacts the image carrier gradually decreases from a point at which contact starts and then gradually returns to the original speed. The width of the developing nip is at least 4 mm, the hardness of the developing roller is 20-40 degrees, the diameter of the developing roller is 40-100 mm, and the bite depth is equal to or greater than {fraction (1/100)} the radius of the developing roller.

Abstract: An non-reproducible image formation preventing apparatus has a recognition section, a storage section and a comparison/determination section. The recognition section performs recognition processing for received image data, determines whether or not the image data is an non-reproducible image, and outputs the determination result to an image formation section. The storage section stores non-reproducible image data recognized as an non-reproducible image by the recognition section. The comparison/determination section compares the non-reproducible image data stored in the storage section with an image based on input image data given through an image process section and finding a match degree therebetween. If either of the comparison/determination section and the recognition section determines that the image is an non-reproducible image, a detection signal is sent to the image formation section for stopping normal print.

Abstract: In an image forming apparatus having a reverse development system and using a two-component developer, respective potentials applied when charging an image bearing member and when applying a development bias to a developer bearing member are attenuated when the image bearing member is driven for an operation other than an image forming operation, compared to respective level of potentials applied when the image bearing member is driven for the image forming operation. Thus, an occurrence of an adhesion of a carrier to an image bearing member is reduced to produce a high quality image, when a power switch of the apparatus is turned off or when a door of the apparatus is opened while the image bearing member is driven for an operation other than the image forming operation, or when the apparatus is activated again after the power switch is turned off.

Abstract: An image forming apparatus has an image bearing member, a charger for charging the image bearing member image forming means for selectively erasing charge on the image bearing member to thereby form an electrostatic image, and a developing device for developing the electrostatic image. The developing device includes a developing roll contacting with the image bearing member and is capable of having a developing bias applied thereto and contacting and spacing device for contacting and spacing the developing roll with respect to the image bearing member. The contacting and spacing device contacts the developing roll having the developing bias applied to the area thereof charged by the charger with the image bearing member at a start of image formation.

Abstract: There is provided a potential controlling method and potential controller of an image forming apparatus, which can certainly prevent toner and carrier from adhering to the surface of an image bearing body at the time of start and stop of image formation and which can also be applied to an image forming apparatus having a high image forming speed.

Abstract: A developing device, includes; a developing roller supporting and conveying mono component toner to a photoreceptor having a static latent image; a supplying roller pressed against the developing roller and rotated so as to supply the toner to the developing roller. In order to perform beneficial supply of the toner to the developing roller, bias voltages are applied so as to generate an electric field which will cause the toner between the developing roller and the supplying roller to be attracted to the developing roller. At a predetermined time before completion of development, the bias voltage applied to the supplying roller is switched so as to create an electric field which will cause the toner to be attracted to the supplying roller. Thus the toner residing between the developing roller and supplying roller after development is removed, whereby it is possible to prevent toner from sticking to that area on the developing roller, after development.

Abstract: An optical scanning device which performs an exposing operation with respect to a photosensitive material such as a printing sheet, etc., by scanning with laser beams in respective colors modulated according to image data is arranged so as to modulate light beams in respective colors projected from respective light sources of a red LD, a green-color SHG laser unit and a blue-color SHG laser unit by AOMs according to image data. Then, the clock frequency control section adjusts an exposure scanning clock for each of the AOM drivers for driving these AOMs individually. It is therefore possible to suppress an aberration in color caused by a shift in light beams in respective colors which are to be projected onto the same target position.

Abstract: In an electrophotographic image recording apparatus of the type using a single-ingredient type developer, i.e., toner, a latent image is electrostatically formed on a photoconductive drum or similar image carrier. A developing unit has a developing roller for conveying the toner deposited thereon, and an intermediate roller for conveying the toner transferred thereto from the developing roller and depositing it on the latent image to thereby produce a corresponding toner image. An image transfer unit transfers the toner image to a cut sheet. During the development of an area of the image carrier other than a latent image area, at least one of biases assigned to the developing roller and intermediate roller, respectively, is switched over to thereby form an electric field different in direction from an electric field assigned to the formation of the toner image between the two rollers. As a result, the toner existing on the intermediate roller is collected by the developing roller.

Abstract: A method and apparatus for eliminating undesirable development of background charge potentials in a multicolor electrostatographic system is disclosed, wherein the application of a developer bias at a given development station is selectively controlled to be substantially equal to or greater than the background image voltage of the image generated by a preceding imaging station such that the voltage differential between toner particles at the development station and the background areas including the previous image areas is substantially zero and the electrostatic forces acting on the toner particles are insufficient to attract the toner particles to the residual image.

Abstract: A developing device is provided with a supporting device for removably and rotatably supporting a toner cartridge containing a toner therein and having a toner supplying opening portion and toner discharge device for discharging the toner in the toner cartridge through the opening portion, driving device for driving the toner discharge device, and cut-off device for cutting off the drive transmission of the driving device during the rotation of the toner cartridge.