Abstract: An image forming apparatus includes a fog controller to control a fogging level of a toner image carrier by adjusting a fog control parameter on the basis of the fogging level detected by a fogging level detection section and the target fogging level stored in a memory section. While varying a value of the fog control parameter, the fog controller makes a detection pattern forming section to form a series of detection patterns between toner images for each page on the toner image carrier, makes the fogging level detection section to detect each of fogging levels of the series of detection patterns, determines a target fog control parameter value on the basis of each fogging level of the series of detection patterns detected and the target fogging level stored, and adjusts the fog control parameter on the basis of the target fog control parameter value.

Abstract: An image forming apparatus includes: a toner image carrier which carries a toner image thereon; a recording medium selection information input section to which recording medium selection information is inputted to select a recording medium to which the toner image carried on the toner image carrier is transferred; a fog controller which sets a fog control parameter value to control a fogging level of the toner image carrier; and an image forming section which forms the toner image to be carried on the toner image carrier based on the fog control parameter set by the fog controller. The fog controller sets the fog control parameter value so that the fogging level of the toner image carrier when the recording medium selection information inputted corresponds to a coated sheet, is lower than that when the recording medium selection information inputted corresponds to a normal sheet.

Abstract: An image forming apparatus may include a first transfer section for transferring a toner image, formed on an image carrier by utilizing a charging section, an exposing section and a developing section, onto a belt shaped intermediate transfer member; and a second transfer section for transferring the toner image on the intermediate transfer member onto a recording material by applying an electric field between a second transfer roller being provided outside the intermediate transfer member and a backup roller being provided inside the intermediate transfer member, the second transfer roller and the backup roller sandwiching the intermediate recording member and the recording material. The second transfer roller may be grounded and a bias voltage may be applied to the backup roller, and a second charging section for charging a surface of the second transfer roller with a predetermined polarity may be included.

Abstract: An image forming apparatus having: an image forming section to form a toner image on an image carrier; a transfer section to transfer onto a transfer medium the toner image formed on the image carrier; and a pair of opposing transfer guide members to guide the transfer medium into the transfer section, wherein a front edge of one transfer guide member, arranged on a side of the image carrier out of the pair of the transfer guide members, is disposed separately from the other transfer guide member, and one side portion of the front edge of the transfer guide member is more protruded than the other side portion into a conveying direction of the transfer medium.

Abstract: An image forming apparatus includes: a moving speed ratio change section which changes a circumferential speed ratio between a surface of a developer bearing member and a surface of an image carrier; and a memory section which stores a target value of fog toner. After the circumferential speed ratio has been changed by the moving speed ratio change section, a controller determines a fog control parameter based on comparing the value detected by the fog toner detection section with the target value stored in the memory section. After then, and the controller controls the moving speed ratio change section to return the circumferential speed ratio to the circumferential speed ratio prior to the change.

Abstract: An image forming apparatus having: an image forming section to form a toner image on an image carrier; a transfer section to transfer onto a transfer medium the tone image formed on the image carrier; and a pair of opposing transfer guide members to guide the transfer medium into the transfer section, wherein a front edge of one transfer guide member, arranged on a side of the image carrier out of the pair of the transfer guide members, is disposed separately from the other transfer guide member, and one side portion of the front edge of the transfer guide member is more protruded than the other side portion into a conveying direction of the transfer medium.

Abstract: An image forming apparatus includes: a toner image carrier which carries a toner image thereon; a recording medium selection information input section to which recording medium selection information is inputted to select a recording medium to which the toner image carried on the toner image carrier is transferred; a fog controller which sets a fog control parameter value to control a fogging level of the toner image carrier; and an image forming section which forms the toner image to be carried on the toner image carrier based on the fog control parameter set by the fog controller. The fog controller sets the fog control parameter value so that the fogging level of the toner image carrier when the recording medium selection information inputted corresponds to a coated sheet, is lower than that when the recording medium selection information inputted corresponds to a normal sheet.

Abstract: An image forming apparatus includes a fog controller to control a fogging level of a toner image carrier by adjusting a fog control parameter on the basis of the fogging level detected by a fogging level detection section and the target fogging level stored in a memory section. While varying a value of the fog control parameter, the fog controller makes a detection pattern forming section to form a series of detection patterns between toner images for each page on the toner image carrier, makes the fogging level detection section to detect each of fogging levels of the series of detection patterns, determines a target fog control parameter value on the basis of each fogging level of the series of detection patterns detected and the target fogging level stored, and adjusts the fog control parameter on the basis of the target fog control parameter value.

Abstract: An image forming apparatus includes: a moving speed ratio change section which changes a circumferential speed ratio between a surface of a developer bearing member and a surface of an image carrier; and a memory section which stores a target value of fog toner. After the circumferential speed ratio has been changed by the moving speed ratio change section, a controller determines a fog control parameter based on comparing the value detected by the fog toner detection section with the target value stored in the memory section. After then, and the controller controls the moving speed ratio change section to return the circumferential speed ratio to the circumferential speed ratio prior to the change.

Abstract: In a vertical type developing device in which plurality of screws are arranged up and down, developer transported by an upper developer transporting screw and developer transported by lower developer transporting screw are properly dispersed. Thereby, developer flows smoothly and further stirs and mixes. As means of it, the followings are included: (1) between the upper screw and the lower screw, properly adjusting developer transporting capabilities and dispersing pressures; (2) arrangement of dispersing members between the upper and lower developer transporting screws; (3) arrangement of openings at a partition wall; (4) arrangement of a developer reservoir portions to a developer accommodating unit; or the like.

Abstract: The present invention is to provide a developing apparatus having a supply screw and a recovery screw both of which are arranged vertically to circulate developer, wherein a component in a normal direction of pressure generated by the recovery screw is made larger than that of pressure generated by the supply screw. Thereby, lowering and raising of developer is suppressed and occurrence of fog on the image and the smoke of toner are prevented. Alternatively, a radial member and a centrifugal member are applied to the supply screw and the recovery screw, respectively. Thereby, developer is prevented from moving between screws in the midst of the transportation. Still alternatively, a preliminary stirring portion is provided on extension of a stirring screw at upperstream side. The preliminary stirring portion has a cylindrical body with inlets and outlets. Both inside and outside of the cylindrical body, screws are provided and inclines of screw blades are reversed to each other.

Abstract: An image forming apparatus, such as a printer or photocopier, has a cleaning device for cleaning an image carrier. The efficiency with which the cleaning device cleans the image carrier is varied in dependence upon the image forming conditions, to thereby reduce wear on both the cleaning device and the image carrier. In one embodiment, cleaning efficiency is varied by changing the contact pressure between a cleaning blade and the image carrier. In a color apparatus with multiple image-forming units, the image forming conditions relate to whether the image to be formed is monochrome, composite color or simul-color.

Abstract: An image forming apparatus includes a movable recording medium bearing member, an image forming device for forming an image on the image bearing member with a developer having an additive and a cleaning device having a cleaning member which makes a contact with the image bearing member for cleaning thereof at a cleaning station. The apparatus further includes a transferring device for transferring the image from the image bearing member to a recording medium. A processing device is mounted between the transfer station and the cleaning station for processing the additive that has not been transferred but still remains on the image bearing member such that one component of the additive remains on the image bearing member and another component of the additive is removed.

Abstract: A supply screw 10 and a collection screw 20 for a developing device equip with screw blades having different forms at particular sections so as to make conveying force of developer different depending on sections. Screw blades for big conveying force are attached within sections where developer distribution is dense while screw blades for small conveying force are attached within sections where developer distribution is sparse. In other words, conveying force is made to be greater at sparse-distribution section while smaller at dense-distribution section. Developer delivery is also promoted by providing different conveying force area within carry-up area where developer is carried up from a supply screw 10 to a collection screw 20 or vice versa. By making conveying force of each section different, developer is uniformly delivered to a developing roll 87 whether in width direction or in axial direction. Furthermore, developer circulation in a developing device becomes smooth.

Abstract: A developing device capable of preventing a reduction of image quality due to disparities in image density or fogging and the like that result from an nonuniform toner concentration or static charge status due to inadequate mixing of a developer. The developing device is provided with a mixing screw for mixing a developer separately from a supply screw for supplying a developer to a developing roller and a collection screw for collecting a developer from the developing roller, the transport direction of the mixing screw being opposite to the transport direction of the supply screw and collection screw.

Abstract: An image forming apparatus having a photosensitive unit including a film disposed thereon. The film wears over time causing its thickness to decrease, which causes non-uniformity in line image data produced by the apparatus. The invention counteracts changes in the film thickness by adjusting the intensity of the edges of the image in response to the amount of wear the apparatus has undergone. The amount of wear can be gauged by detecting the number of rotations made by the photosensitive unit or the number of sheets processed by the photosensitive unit. The invention has the particular advantage of ensuring consistency in the thickness of line images. A method for controlling exposure is also described.

Abstract: This invention relates to a developer for electrophotography comprising:a domain resin phase containing specified additives,a matrix resin phase containing specified additives anda dispersion assistant,the matrix resin having a low compatibility with the domain resin, and the dispersion assistant having a compatibility with both of the domain resin and matrix resin and an Izod impact value higher than the matrix resin.

Abstract: The present invention relates to plural color toners for use in image-forming method of forming images cyclically with the toners, developers comprising the toners and image-forming method by use of the toners or developers and image-forming system therefor, and is characterized in that use is made of toners which have their surfaces in a substantially identical state.

Abstract: A toner for electrophotography obtained by melting and kneading a kneaded material prepared by melting and kneading a domain resin and a coloring agent, a matrix resin having a low compatibility with the domain resin, and a dispersion assistant having a compatibility with both of the domain resin and matrix resin and a Izod impact value higher than the matrix resin to obtain a colored composition, followed by pulverizing and classifying the colored composition.

Abstract: The disclosure relates to a developing apparatus having a developing sleeve for making a latent image visible and a bucket roller for supplying developer to the developing sleeve including a plurality of buckets provided on the circumferential surface of the bucket roller at a predetermined spacing and base portions for supporting the buckets respectively.Each of the buckets are loosely provided at the base portions respectively so as to pivot with respect to the base portions. This construction effectively prevents the aggregation and accumulation of developer at the bucket portion, as well as gives sufficient flowability to the developer.