Abstract: A cleaning blade is described which hardly suffers from cut surface abrasion at the edge having a chamfered portion. A flat chamfered portion 60a is formed at the edge of the cleaning blade 60 where the chamfer angle thereof closer to the surface of an intermediate transfer belt 41 is set within a range of 20° to 65°. The chamfered portion 60a in a rubbing contact during printing is therefore prevented from being dragged in the moving direction ‘a’ of the surface of the intermediate transfer belt 41 to increase the rubbing contact width, and cut surface abrasion can be avoided.

Abstract: An image forming apparatus includes a transfer belt, a pressure receiving roller, a suspension roller, a secondary transfer roller, and an endless support belt. The support belt is stretched over at least one of the pressure receiving roller and the suspension roller. When pressing the transfer belt between the pressure receiving roller and the secondary transfer roller, and nipping paper between the transfer belt and the secondary transfer roller, an angle defined by the portion, upstream from the secondary transfer roller, of the transfer belt and an imaginary line connecting the pressure-receiving-roller axis with the secondary-transfer-roller axis is less than 90 degrees. A part of the support belt is held between the transfer belt and at least one of the two rollers over which the support belt is stretched.

Abstract: An image forming apparatus includes a transfer belt, a pressure receiving roller, a secondary transfer roller, and a belt movement restricting section. The belt movement restricting section is disposed close to the back of the belt. When pressing the belt between the pressure receiving roller and the secondary transfer roller, and nipping paper between the belt and the secondary transfer roller, an angle defined by the portion, upstream from the secondary transfer roller, of the belt and an imaginary line connecting the pressure-receiving-roller axis with the secondary-transfer-roller axis is less than 90 degrees. During non-secondary-transfer mode, the belt movement restricting section is separated from the belt. During secondary transfer, the belt movement restricting section holds the belt not to let the belt pushed by the paper move toward the pressure receiving roller.

Abstract: An image forming apparatus including a transfer section for transferring a toner image formed on an image bearing member onto a sheet by pressure contact of the sheet against the image bearing member with a transfer member; a cleaning section having a cleaning blade to remove residual toner on the image bearing member; and a control section for controlling a rotation of the image bearing member so as to carry out a return action of a blade configuration which stops or reverses the rotation of the image bearing member, when the rotation amount reaches a predetermined value, wherein the control section additionally carries out the return action when the rotation amount reaches a value smaller than the predetermined value, in a case where a size of a sheet in a current job is larger than a size a sheet having been passed through in a previous job.

Abstract: An image forming apparatus including: an image forming section having a intermediate transfer body to carry a toner image on a photoreceptor and transfer the toner image onto a sheet of paper; a cleaning section for removing residual toner on the intermediate transfer body by bringing a cleaning blade into close contact with the intermediate transfer body; and a control section for controlling a rotation of the intermediate transfer body so as to carry out a return action of a blade configuration which stops or reverses the rotation of the intermediate transfer body, when a rotation amount reaches a predetermined value, wherein the control section carries out the return action when the rotation amount reaches a value smaller than the predetermined value, in a case where a plurality of previous printing jobs is determined to be intermittent printing.

Abstract: A cleaning device for cleaning a belt member, includes a cleaning blade; a removing member coming in contact with the surface of the belt member so as to remove foreign matter adhering on the surface of the belt member; and a contact pressure changing section to change a contact pressure between the removing member to the belt member, wherein, when the contact pressure between the removing member and a region of the belt member corresponding in position to a toner image to be not transferred to a paper sheet is made P1, and the contact pressure between the removing member and a region of the belt member corresponding in position to a toner image to be transferred to a paper sheet is made P2, the contact pressure changing section changes the contact pressure to satisfy the conditional formula: (P1<P2).

Abstract: An image forming device that transfers a plurality of toner images of different colors in layers, onto an intermediate transfer member by controlling a timing of forming each of the plurality of toner images, based on a reference position on a surface of the intermediate transfer member, the image forming device comprising: an uneven part detecting unit operable to detect at least one uneven part that is any of a depression and a projection, on the surface of the intermediate transfer member; and a reference uneven part setting unit operable to set a reference uneven part that defines the reference position, from among the at least one uneven part detected by the uneven part detecting unit.

Abstract: An image forming apparatus includes: a cleaning blade provided on an intermediate transfer member to which a toner image formed on at least one image forming section is primary transferred and on a secondary transfer section which transfers the toner image transferred on the intermediate transfer member onto a transfer material, respectively, which cleans the toner image remained thereon, respectively; a bias power source which is electrically connected to the secondary transfer section; and a controller which causes the image forming section to form a patch toner image onto a non-image area on the image carrier corresponding to an area between adjoining two transfer materials, and causes the bias power source to conduct a power control in synchronization with a positional movement timing of the patch toner image, to supply selectively the patch toner image to the intermediate transfer member and the secondary transfer section.

Abstract: An image forming apparatus capable of appropriately cleaning an image carrier is provided. An image forming apparatus 1 including toner cartridges 11Y, 11M, 11C, and 11K, a developing section which forms toner images, an image carrier 4 which carries the toner images formed by the developing section, a transfer member 5 which transfers toner images from the image carrier 4 to a recording sheet S, and a cleaner 14 which is operable for press and release operation to/from the image carrier 4 and which is pressed to the image carrier 4 to scrape off the toner remaining on the image carrier 4 is provided with a control means 23 which decreases the number of press and release operations of the cleaner 14 when the cumulated value of the number of images formed since the first use of the brand-new toner cartridges 11Y, 11M, 11C, and 11K is large.

Abstract: An image forming apparatus increases a primary-transfer pressure contact force at the times of primarily transferring black color to a first sheet and yellow and black colors to a second sheet or subsequent sheets in order to prevent misalignment of colors. The apparatus also decreases the primary-transfer pressure contact force at the times of primarily transferring yellow, magenta and cyan colors to the first sheet, and magenta and cyan colors to the second sheet or subsequent sheets in order to prevent central blurs of colors.

Abstract: An image forming apparatus capable of appropriately cleaning an image carrier is provided. An image forming apparatus 1 including toner cartridges 11Y, 11M, 11C, and 11K, a developing section which forms toner images, an image carrier 4 which carries the toner images formed by the developing section, a transfer member 5 which transfers toner images from the image carrier 4 to a recording sheet S, and a cleaner 14 which is operable for press and release operation to/from the image carrier 4 and which is pressed to the image carrier 4 to scrape off the toner remaining on the image carrier 4 is provided with a control means 23 which decreases the number of press and release operations of the cleaner 14 when the cumulated value of the number of images formed since the first use of the brand-new toner cartridges 11Y, 11M, 11C, and 11K is large.

Abstract: A secondary cleaning device has a cleaning brush, collection roller, and controller. The cleaning brush is driven by a drive mechanism and thereby rotates in a state that brush fibers thereof are contacting with a secondary transfer belt to collect toner on the secondary transfer belt. The collection roller is driven by another drive mechanism and thereby rotates in a state contacting with the cleaning brush to collect toner from the cleaning brush. The collection roller rotates in such a manner that the collection roller and the cleaning brush move in the same direction with each other at a contact area between the collection roller and the cleaning brush. The controller controls the drive mechanism such that the circumferential speed ratio of the collection roller with respect to the cleaning brush is greater than one and smaller than two.

Abstract: An image forming device that transfers a plurality of toner images of different colors in layers, onto an intermediate transfer member by controlling a timing of forming each of the plurality of toner images, based on a reference position on a surface of the intermediate transfer member, the image forming device comprising: an uneven part detecting unit operable to detect at least one uneven part that is any of a depression and a projection, on the surface of the intermediate transfer member; and a reference uneven part setting unit operable to set a reference uneven part that defines the reference position, from among the at least one uneven part detected by the uneven part detecting unit.

Abstract: An image forming apparatus increases a primary-transfer pressure contact force at the times of primarily transferring black color to a first sheet and yellow and black colors to a second sheet or subsequent sheets in order to prevent misalignment of colors. The apparatus also decreases the primary-transfer pressure contact force at the times of primarily transferring yellow, magenta and cyan colors to the first sheet, and magenta and cyan colors to the second sheet or subsequent sheets in order to prevent central blurs of colors.

Abstract: A cleaning device is provided with a conductive fur brush kept in contact with a transfer belt, a conductive brush kept in contact with the transfer belt upstream of the fur brush in the feed direction, and a single of constant-current d.c. power supply. The fur brush is connected to the constant-current d.c. power supply, and the conductive brush is grounded. A current flows from the constant-current d.c. power supply via the transfer belt to the conductive brush.

Abstract: An image forming apparatus has a control section. The control section controls a power supply for applying a bias voltage to a cleaning brush and a driving mechanism for the cleaning brush so that the cleaning brush 41 begins to rotate when a predetermined delay time has passed after the start of the application of the bias voltage to cleaning brush. Toner remaining on an image bearing body at an upstream side of a nip portion between the cleaning brush and the image bearing body is surely removed.

Abstract: A secondary cleaning device has a cleaning brush, collection roller, and controller. The cleaning brush is driven by a drive mechanism and thereby rotates in a state that brush fibers thereof are contacting with a secondary transfer belt to collect toner on the secondary transfer belt. The collection roller is driven by another drive mechanism and thereby rotates in a state contacting with the cleaning brush to collect toner from the cleaning brush. The collection roller rotates in such a manner that the collection roller and the cleaning brush move in the same direction with each other at a contact area between the collection roller and the cleaning brush. The controller controls the drive mechanism such that the circumferential speed ratio of the collection roller with respect to the cleaning brush is greater than one and smaller than two.

Abstract: A cleaning device is provided with a conductive fur brush kept in contact with a transfer belt, a conductive brush kept in contact with the transfer belt upstream of the fur brush in the feed direction, and a single of constant-current d.c. power supply. The fur brush is connected to the constant-current d.c. power supply, and the conductive brush is grounded. A current flows from the constant-current d.c. power supply via the transfer belt to the conductive brush.

Abstract: An apparatus for removing developer from a developer carrier includes a developer-charge-eliminating means including a first elastic member. The first elastic member is electrically conductive and contacts the developer carrier with an uneven surface. Preferably, the uneven surface includes exposed cells of a foamed body. The uneven surface of the first elastic member insures that sufficient contact and frictional resistance is applied to excess developer on a developer carrier. Preferably, the first elastic body is backed by a backing member which is more flexible than the first elastic member. The flexible second elastic body further insures that the charge-eliminating member sufficiently contacts the developer carried by the developer carrier even with extended use.

Abstract: An erasing device includes a sheet-like erasing member. The erasing member is supported by an electric charger in contact with the image bearing member for erasing a residual electric charge from the image bearing member. Preferably, the erasing member is supported by a supporting member which in turn is supported by the electric charger. Therefore, the erasing member can be disposed relative to the image bearing member with a greater precision without using any additional rigid member. Also, the image bearing member can be erased without any defect, which results in that the image bearing member is uniformly charged in the subsequent charging.