Abstract: An image forming apparatus includes an image carrier, a charging device to be applied with a charging voltage, an exposure device, a developer carrier to be applied with a development voltage, a developer supplying member to be applied with a supply voltage, a developer regulation member to be applied with a regulation voltage, and a voltage controller. The developer carrier has thereon a developer having a charge amount Q/M. The charge amount Q/M satisfies 25 [?C/g]?|Q/M|?40 [?C/g]. The image carrier has a surface potential Vopc, the development voltage is expressed as Vdb, and the developer carrier has a developer layer potential Vtnr thereon. The developer layer potential Vtnr relative to a difference between the surface potential Vopc and the development voltage Vdb is expressed by a ratio ?. The ratio ? satisfies 0.1???0.2.

Abstract: An image forming apparatus includes a developer bearing body for supplying developer to a surface of the image bearing body, on which an electrostatic latent image is formed by a latent image forming unit; a driving unit for rotating the developer bearing body; a speed control unit for determining a rotation speed of the developer bearing body; a drive control unit for controlling the driving unit so that the developer bearing body rotates at the determined rotation speed; and a control unit for determining the amount of developer to be disposed of on the basis of the determined rotation speed and controlling disposal of the determined amount of developer on the surface of the developer bearing body.

Abstract: A image forming apparatus includes a rotatable image bearing body, an exposing unit that irradiates the image bearing body to form a latent image, a developer bearing body that develops the latent image to form a developer image, a transfer unit that transfers the developer image to a recording medium, a feeding unit that feeds the recording medium, a density detecting unit that detects a developer density of the developer image transferred to the recording medium, and a speed difference control unit that controls a difference of a circumferential speed of the image bearing body and a feeding speed of the recording medium fed by the feeding unit. The speed difference is controlled based on a density of a thin line pattern transferred to the recording medium detected by the density detecting unit.

Abstract: An image forming apparatus includes an image forming unit having image forming elements and a fixing unit. The image forming elements includes an image carrier, a charging unit, a developer carrier, and a developer supplier. The image forming apparatus further includes a post unoperated period image formation preparation processor operable to, when the unoperated period, which is a time period from an end of an image forming operation to a start of a subsequent image forming operation is equal to or greater than a threshold, perform an idling operation to rotate the image carrier while applying a post unoperated period image formation preparation voltage, which is different from a normal image formation voltage, to a given one or more of the image forming elements.

Abstract: An image forming apparatus forms images. A developer bearing body receives a first voltage and supplies developer to the electrostatic latent image formed on an image bearing body. A supplying member receives a second voltage and supplies the developer to said developer bearing body. A detector detects at least one of an environmental condition, e.g., temperature and humidity outside of an apparatus and an environmental condition e.g., temperature inside of the apparatus. A controller controls the difference between the first voltage and the second voltage in accordance the environmental conditions. The controller makes a decision to determine whether the outside temperature is not lower than a first reference, whether outside humidity is not higher than a second reference, and whether inside temperature is not lower than a third reference. If the above criteria are met, the controller decreases the absolute value of the difference.

Abstract: An image forming apparatus includes an image supporting member; a developer supporting member for attaching developer to the image supporting member to form a developer image; a regulation member for forming a thin layer of the developer on the developer supporting member; a charge adjustment member for receiving a charge adjustment voltage and contacting with the thin layer of the developer formed on the developer supporting member to adjust a charge amount of the developer; and a charge adjustment voltage switching unit for switching the charge adjustment voltage applied to the charge adjustment member between an image forming voltage upon forming an image and a non-image forming voltage during a preparation operation.

Abstract: An image forming apparatus includes a plurality of image forming units each having an image supporting member, a developer supporting member, and a cleaning member for cleaning developer on the image supporting member. The image forming apparatus further includes a transfer device for transferring a developer image to a medium; a fixing device for fixing the developer image to the medium; a first detection unit for detecting a first physical value of an external environment of the image forming apparatus; a second detection unit for detecting a second physical value of an internal environment of the image forming apparatus; and a control unit for determining whether at least one of the image forming units performs a developer discard mode in which developer is discarded according to the first physical value, the second physical value, and a distance between the one of the image forming units and the fixing device.

Abstract: An electrostatic recording head includes a plurality of elongated head chips fixed on a head base in a linear alignment along their longitudinal direction. The head chip has a dielectric layer, a plurality of line electrodes provided on one surface of the dielectric layer and extending at predetermined intervals in the longitudinal direction, and a plurality of finger electrodes provided on one surface of the dielectric layer and arranged to cross the line electrodes to together form a matrix. A control electrode or electrodes are provided to face the finger electrodes through an insulator layer. The finger electrodes extend parallel to an end face of the head chip.

Abstract: An electric charge generator for use in an apparatus for producing an electrostatic latent image includes a plurality of charge generation controlling devices, each charge generation controlling device including: an insulating substrate; a line electrode formed on the insulating substrate; a solid dielectric film formed on the surface of the line electrode; a finger electrode having a hole for generating an electric charge, the hole being formed in the central part of the finger electrode, the finger electrode being formed on the solid dielectric film; a solid insulating film having a hole for passing the electric charge, the hole being formed in the central part of the solid insulating film, the solid insulating film being formed on the finger electrode; and a screen electrode having a hole for ejecting the electric charge, the hole being formed in the central part of the screen electrode, the screen electrode being formed on the surface of the finger electrode via the solid insulating film; wherein the plur

Abstract: An original conveying apparatus includes a follower roller unit which is moved to its deployed position to define an extension of an original conveying path over the upper surface of the copying machine when a book carrier is used in order to convey an original having substantial thickness. A follower roller holding member is disposed within the unit and moves in interlocked relationship with the movement of the unit to its deployed position so as to maintain the follower roller in its position projecting above an original guide surface when the unit is moved to its deployed position.

Abstract: In a collator for use in combination with an electrophotographic copying machine which discharges copies of originals in succession at the same time interval, deflection claws for delivering successive copies of a manuscript into successive bins are provided at inlets of respective bins and two endless belts each having an actuator for driving the deflection claws are provided movably along the successive bins. The two endless belts are driven by two different controlling circuits, respectively in an independent manner. During the copy delivering operation by the first endless belt for a plurality of copies of a certain document, it is possible to initiate the copy delivering operation by the second endless belt for a plurality of copies of the next document.

Abstract: A collator includes a series of twenty bins arranged in parallel with each other. A copy feeding member feeds copies supplied from a copying machine along inlets of the successive bins. First and second deflecting devices are arranged at uppermost two bins for delivering the copies into the uppermost two bins. A distributor is movable between the third bin and the twentieth bin for delivering the copies into the bins. An extra tray is provided separately from the bins. The collator further comprises a collate mode selecting member, a job separation mode selecting member and a non-collate mode selecting member.

Abstract: A collator includes a series of twenty bins arranged in parallel with each other, a copy feeding member for feeding copies supplied from a copying machine along inlets of the successive bins, first and second deflecting devices arranged at the uppermost two bins for delivering the copies into the uppermost two bins and a distributor movable between the third bin and the twentieth bin for delivering the copies into the bins. The collator can treat the copies in a job separation mode in which all copies of each documents are delivered into respective bins in succession, while the distributor is advanced bin by bin in response to a distributor advance signal produced by a variable timer which is actuated upon detection of the rear edge of the last copy of an Nth original by an entrance switch to set a time period represented by b+(N-1).times.a/V.sub.1, wherein a is a pitch between successive bins, b is a distance from the entrance switch to the first bin and V.sub.1 is a copy feed speed in the collator.