Abstract: An image forming apparatus for executing image forming process on a page by page basis including: a toner image forming section for producing a visible image formed of toner as a toner image on an image carrier; a transfer section which performs a transfer process for transferring the formed toner image onto a recording medium; a cleaning section which removes toner remaining on the image carrier after the transfer process; a waste toner storing section in which the removed toner is accumulated; and a waste toner amount detecting section which detects an amount of the toner accumulated in the waste toner storing section on the basis of at least three detection levels.

Abstract: A sheet P on which an image of a developer is unfixed is recovered from a transfer unit 6 to a sheet recovery portion 64, the sheet P is bent with the surface of the sheet P on which the image of the developer has been transferred facing inward and, while remaining bent, the sheet P drops downward between an outer guide plate 72 and a transfer convey belt 51, then an openable cover 74 is opened to remove the sheet P.

Abstract: Cleaning performance of a cleaning pad for cleaning a charging wire is maintained so that the charging voltage of an image carrier by a charging wire is stabilized. A charging wire cleaning apparatus is provided with a cleaning pad for cleaning a charging wire which charges an image carrier, a slider which is a supporting body for supporting the cleaning pad, and a screw shaft which is a moving mechanism for reciprocating the slider in parallel to the charging wire. When the slider is at a predetermined position of the reciprocation range, the cleaning pad and the charging wire are separated, and the cleaning pad is adapted to be shifted with respect to the charging wire in this state.

Abstract: An image forming apparatus is provided in which an electrostatic latent image formed on a surface of a photoreceptor is developed into a toner image with a developing device, and in which a printing paper transported on a transport belt is brought into contact with the surface of the photoreceptor and an electric field is applied to the printing paper from a rear surface of the transport belt by a transfer roller so as to transfer the toner image onto the printing paper, the transfer roller capable of applying different levels of electric field to the printing paper, so that a predetermined transfer electric field is applied to a region other than a leading edge of the printing paper being transported, and that a weak electric field weaker than the predetermined transfer electric field is applied to the leading edge of the printing paper being transported.

Abstract: An image forming apparatus includes a history storage portion for storing the usage history involving the number of prints of the image forming apparatus, and a processing time controller for changing the time of the pre-processing operation before or the time of the post-processing operation after a printing process of the printing portion, based on the stored usage history so as to exclude the influence of the unfixed developer on the printing process.

Abstract: A sheet conveying device that facilitates solution of a jam of a sheet and which is capable of inhibiting shortening of life due to a jam is provided. A sheet having a bent leading end that is very likely to jam is positively made to jam at a blocking portion formed on an upstream side of an image forming station in a sheet conveying direction thereof. Consequently, it is possible to more easily perform an operation of solving a jam than in a case where a jam of the sheet occurs in the image forming station. Moreover, it is possible to prevent deterioration of the image forming station due to a jam, and inhibit shortening of the life of the image forming station resulting from a jam.

Abstract: In one embodiment of the present invention, an image forming apparatus is presumed that develops an electrostatic latent image on the surface of a photoreceptor, thus forming a visible image on the surface of the photoreceptor, transfers the visible image from the surface of the photoreceptor to recording paper, separates the recording paper from the surface of the photoreceptor with a separation claw, and cleans the surface of the photoreceptor with a cleaning blade. The cleaning blade is in sliding contact with the surface of the photoreceptor, and smoothes damage that has been formed on the surface of the photoreceptor by contact of the separation claw.

Abstract: An image forming apparatus of the present invention predicts the occurrence of an image elongation, in other words, predicts that an image transferred is lengthened on a sheet due to slipping of the sheet with respect to a photoreceptor at a transfer nip portion. If the occurrence of the image elongation is predicted, the amount of a rear edge portion to be deleted from an electrostatic latent image is obtained on the basis of a sheet rear edge void setting change table, the amount of the rear edge portion to be deleted is added to the default amount of a rear edge void, a portion corresponding to the rear edge portion of an image of image information is deleted, and a printing process is carried out. In this way, even if a slip phenomenon occurs, in other words, the sheet slips with respect to the photoreceptor, it is possible to surely secure a blank space at a rear edge portion of the sheet.

Abstract: A transfer mechanism includes: a transfer unit having a transfer belt; and a belt contact and separation assembly for bringing the transfer belt into, and separating it away from, an electrostatic latent image support by shifting the position of the transfer unit. The belt contact and separation assembly includes:a multiple number of transfer unit shifters that abut the transfer unit and shift the position of the transfer unit; a multiple number of linkage members that link with the plural transfer unit shifters, correspondingly; an elastic member for coupling the plural linkage members; and a driver for actuating the transfer unit shifters through the linkage members.

Abstract: An image recording apparatus includes a first pullout unit, a second pullout unit, and a first lock mechanism. The first unit is movable along a first axis between a first retracted position where the first unit is fully retracted in the apparatus, and a first exposed position where at least one side surface thereof is fully exposed to the front of the apparatus. The second unit is movable along a second axis, which is perpendicular to the first axis, between a second retracted position where the second unit is fully retracted in the first unit, and a second exposed position where the second unit is exposed to a side of the side surface of the first unit. The first lock mechanism prevents movement of the second unit from the second retracted position to the second exposed position when the first unit is not in the first exposed position.

Abstract: A combined resistance R1=Vt1/I1 (MO) of a transfer belt (61) and a recording sheet obtained when a transfer current I1 (?A) passes through the transfer belt (61) and the recording sheet upon application of a first transfer bias voltage Vt1 (V) to a transfer roller (6b) from a high-voltage power source (6f) and a combined resistance R2=Vt2/I2 (MO) of the transfer belt (61) and the recording sheet obtained when a transfer current I2 (?A) passes through the transfer belt (61) and the recording sheet upon application of a second transfer bias voltage Vt2 (V) to the transfer roller (6b) from the high-voltage power source (6f), are established to have the relationship: R2/R1=7 ?(I2)?0.5 therebetween.

Abstract: A charging device includes a long electrode, a cleaning member, a timing device, a drive source, a load measuring device, and a control device. The drive source moves the cleaning member in the outward direction for a first time period after the outward passage time and then reverses the cleaning member in the homeward position. The load measuring device measures driving load imposed on the drive source while the cleaning member is being moved. The control device controls motion of the drive source to turn the cleaning member from the outward direction to the homeward direction at a predetermined objective point near the second end, based on sum of driving loads imposed on the drive source while the cleaning member is being moved from the first point to a second point located along the outward direction.

Abstract: In an image forming method, an electrostatic latent image formed on a surface of a photoreceptor is developed into a developer image with a developer, and a printing paper transported on a transfer belt is brought into contact with the surface of the photoreceptor so as to transfer the developer image onto the printing paper. The printing paper is transported in a proper transport direction, in which a projection generated in one direction on the printing paper as a result of cutting the printing paper in a printing paper manufacturing process does not face a surface of the transfer belt at a leading edge of the printing paper being transported on the transfer belt. In this way, even in the presence of the projection generated when the printing paper is cut, the printing paper naturally strips off from the surface of the photoreceptor, thereby preventing toner contamination caused by a striping claw in contact with the leading edge of the printing paper.

Abstract: A loop belt of an image forming apparatus is formed by splicing belt members made of different materials in a width direction of the loop belt.

Abstract: A feed roller assembly includes a shaft, a plurality of rollers, and a plurality of covers. The rollers are fixed to the shaft at intervals along it. The covers are positioned at both ends of the rollers and surround the shaft, without being fixed to it. Paper dust falls from the outer cylindrical surfaces of the rollers and accumulates on the covers, without coming into direct contact with the cylindrical surface of the shaft. Because the covers are not fixed to the cylindrical surface of the shaft, they rotate at a lower speed than the shaft.

Abstract: A charging device includes a rotatable screw gear, a motor, a support, and a protruding member. The screw gear is positioned along length of a linear electrode. The motor rotates the screw gear in forward and reverse directions. The support holds the cleaning member mounted so as to be in contact with the electrode, and is mounted unrotatably but reciprocably between a first end and a second end of the electrode. The member extends perpendicular to the length of the electrode from the support, and has a projection for being elastically fitted into a thread groove of the screw gear along a radial direction of the screw gear. The member is configured in such a manner that a distance between a starting point of elastic deformation of the member and a contact point between the projection and a thread of the screw gear differs according to whether the support is moved forward or backward.

Abstract: An image transfer device includes an image transfer electrode roller which is disposed face to face with a photosensitive drum with a printing sheet passing between the image transfer electrode roller and the photosensitive drum. The image transfer device is structured such that the image transfer electrode roller can be shifted back and forth along a transport direction of the printing sheet. A voltage is applied to the image transfer electrode roller to create an image transfer electric field between the image transfer electrode roller and the photosensitive drum for transferring a toner image formed on the photosensitive drum onto the printing sheet. The image transfer electrode roller is brought to one of different positions along a transport direction of the printing sheet selected according to information on properties of the printing sheet and transfers the toner image onto the printing sheet at that position.

Abstract: Transfer roller(s) is/are such that either end thereof is formed from fibrous electrically conductive component(s) and such that cylindrical portion(s) in central region(s) is/are, for example, formed from metal roller-like structure(s), either fibrous electrically conductive component outer end being arranged so as to extend somewhat beyond either transfer/transport belt side. Furthermore, outside diameter(s) approximated by tips of respective individual fiber(s) of fibrous electrically conductive component(s) is/are somewhat larger than diameter(s) of metal roller-like structure(s). This makes it possible for electric field(s) to be applied, and for charging to occur, along the full width(s) of transfer/transport belt(s).

Abstract: An image forming apparatus and a maintenance method thereof are provided to enable rotation and replacement of a peeling claw at a suitable timing before the peeling claw is deformed or damaged. Several peeling members are disposed in a width direction of a drum-shaped photoreceptor. Each peeling member is disposed with a peeling claw and a collision sensor detecting that the peeling claw collides with a sheet. A collision history value of each peeling claw is stored and managed based on a collision detection signal from the collision sensor; if the peeling claw reaching a preset rotation request value exists in the read collision history values of the peeling claws, a rotation request of the relevant peeling claw is reported; the collision history value of the rotated peeling claw is rewritten; and if the peeling claw reaching the rotation request value does not exist, a print process is performed.

Abstract: In an image forming apparatus of the present invention, a scorotron charging device has a meshed grid electrode which is meshed more coarsely in a high-speed apparatus than a meshed grid electrode in a low-speed apparatus according to a circumferential velocity of a photoreceptor. With this arrangement, it is possible to charge the photoreceptor at a predetermined potential in the high-speed apparatus, without increase of the amount of ozone generation and upsizing of the image forming apparatus.