Abstract: A print density adjusting device of print image information includes a print image information acquirer configured to acquire the print image information. A forming information acquirer is configured to acquire forming information of a medium on which an inkjet printer prints and which is to be bent. A vertex detector is configured to detect a vertex of a bent part which is to be bent based on the forming information. A bending angle detector is configured to detect a bending angle of the bent part based on the forming information. A print density adjuster is configured to adjust a print density of the print image information acquired by the print image information acquirer based on the vertex detected by the vertex detector and based on the bending angle detected by the bending angle detector.

Abstract: An image forming apparatus includes an image carrier, a developer carrier arranged to face the image carrier to form a developing nip portion, which carries developer containing toner for developing a latent image formed on the image carrier, a developing unit having a developer regulating member that regulates a thickness of a layer of the carried developer, an air sending duct having an air sending path provided on the developing unit, which sends air to the developer carrier and a suction duct having a suction path provided on the developing unit, which sucks air from the developer carrier. The developer regulating member is arranged on an air sending duct side, and the air sending and suction paths are arranged to be connected by forming a space surrounded by a surface of the developer carrier, the developer regulating member and a wall forming the suction path.

Abstract: An image forming apparatus having an image carrier for forming an electrostatic latent image and a developing unit for developing the electrostatic latent image with a two-component developing agent, the developing unit includes: a developing agent carrier for developing the electrostatic latent image to form a visible image, having inside thereof a development main magnetic pole for forming a bristle of a magnetic brush; and a plurality of magnetic poles for conveying the developing agent, wherein the developing unit performs a counter type contact developing method, and wherein, a development area is formed so that, a contact width of the bristle of the magnetic brush is 70% or less with respect to a development width, and a center position of the contact width is positioned on an upstream side with respect to a center position of the development width in a rotation direction of the image carrier.

Abstract: A print density adjusting device of print image information includes a print image information acquirer configured to acquire the print image information. A forming information acquirer is configured to acquire forming information of a medium on which an inkjet printer prints and which is to be bent. A vertex detector is configured to detect a vertex of a bent part which is to be bent based on the forming information. A bending angle detector is configured to detect a bending angle of the bent part based on the forming information. A print density adjuster is configured to adjust a print density of the print image information acquired by the print image information acquirer based on the vertex detected by the vertex detector and based on the bending angle detected by the bending angle detector.

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: High quality images are provided by controlling development conditions based on the proportion of the toner layer potential difference, which a difference between the toner layer potential and electrostatic latent image potential, to the development contrast potential difference, which is a difference between the development bias potential and electrostatic latent image potential. The control section for controlling a development power supply controls the voltage supplied by the development power supply, based on the toner layer potential difference and development contrast potential difference in the development section. This arrangement ensures formation of high-quality images free from concentration of toner.

Abstract: There is described an image forming apparatus, which makes it possible to suppress quality degradation of an image on the basis of a developing electric current profile without optically detecting density of a patch image. The image forming apparatus includes: a developing current detecting sensor to detect a developing current; and a control section that conducts consecutive operations of: creating a detecting-use image pattern for detecting a developing characteristic, by aligning a plurality of image patterns, which are different from each other in density; forming a latent image of the detecting-use image pattern onto the photoreceptor element; finding a developing electric current profile, which represents a transition of the developing electric current flowing during an operation of developing the detecting-use image pattern, from an outputted signal of the developing current; and changing an image forming condition, based on the developing electric current profile found by the finding operation.

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: High quality images are provided by controlling development conditions based on the proportion of the toner layer potential difference, which a difference between the toner layer potential and electrostatic latent image potential, to the development contrast potential difference, which is a difference between the development bias potential and electrostatic latent image potential. The control section for controlling a development power supply controls the voltage supplied by the development power supply, based on the toner layer potential difference and development contrast potential difference in the development section. This arrangement ensures formation of high-quality images free from concentration of toner.

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 includes an image carrier, a developer carrier arranged to face the image carrier to form a developing nip portion, which carries developer containing toner for developing a latent image formed on the image carrier, a developing unit having a developer regulating member that regulates a thickness of a layer of the carried developer, an air sending duct having an air sending path provided on the developing unit, which sends air to the developer carrier and a suction duct having a suction path provided on the developing unit, which sucks air from the developer carrier. The developer regulating member is arranged on an air sending duct side, and the air sending and suction paths are arranged to be connected by forming a space surrounded by a surface of the developer carrier, the developer regulating member and a wall forming the suction path.

Abstract: There is described an image forming apparatus, which makes it possible to suppress quality degradation of an image on the basis of a developing electric current profile without optically detecting density of a patch image. The image forming apparatus includes: a developing current detecting sensor to detect a developing current; and a control section that conducts consecutive operations of: creating a detecting-use image pattern for detecting a developing characteristic, by aligning a plurality of image patterns, which are different from each other in density; forming a latent image of the detecting-use image pattern onto the photoreceptor element; finding a developing electric current profile, which represents a transition of the developing electric current flowing during an operation of developing the detecting-use image pattern, from an outputted signal of the developing current; and changing an image forming condition, based on the developing electric current profile found by the finding operation.

Abstract: An image forming apparatus having an image carrier for forming an electrostatic latent image and a developing unit for developing the electrostatic latent image with a two-component developing agent, the developing unit includes: a developing agent carrier for developing the electrostatic latent image to form a visible image, having inside thereof a development main magnetic pole for forming a bristle of a magnetic brush; and a plurality of magnetic poles for conveying the developing agent, wherein the developing unit performs a counter type contact developing method, and wherein, the development area is formed so that, a contact width of the bristle of the magnetic brush is 70% or less with respect to a development width, and a center position of the contact width is positioned on an upstream side with respect to a center position of the development width in a rotation direction of said image carrier.

Abstract: An image forming apparatus incorporating: an image forming body; and a developing unit having a developer carrier, a magnetic field generator, a developer restriction member, a first conveyer, and a second conveyer, wherein the magnetic field generator has: a main magnetic pole; pickup magnetic pole; and a strip-off magnetic pole, wherein the developing unit satisfies following conditions: (a) the second conveyer is a screw conveyer having an outer diameter within 24 mm-30 mm, rotating speed of 300-500 rpm, (b) the pickup magnetic pole is arranged at an angle of 25°-60° downstream with a line connecting a rotation centers of the developer carrier and the second conveyer, (c) the strip-off magnetic pole is arranged at 60°-80° upward with the line,(d) a transporting capability of the first conveyer is larger than that of the second conveyer.

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: An image forming apparatus incorporating: an image forming body; and a developing unit having a developer carrier, a magnetic field generator, a developer restriction member, a first conveyer, and a second conveyer, wherein the magnetic field generator has: a main magnetic pole; pickup magnetic pole; and a strip-off magnetic pole, wherein the developing unit satisfies following conditions: (a) the second conveyer is a screw conveyer having an outer diameter within 24 mm-30 mm, rotating speed of 300-500 rpm, (b) the pickup magnetic pole is arranged at an angle of 25°-60° downstream with a line connecting a rotation centers of the developer carrier and the second conveyer, (c) the strip-off magnetic pole is arranged at 60°-80° upward with the line,(d) a transporting capability of the first conveyer is larger than that of the second conveyer.

Abstract: This invention relates to an image forming apparatus including a developing unit which develops an electrostatic latent image formed on an image carrier by using a two-component developing agent containing polymerized toner. The developing unit includes a supply/convey member which conveys the two-component developing agent in the axial direction while agitating it and a toner density sensor which detects the toner density of the two-component developing agent. The toner density sensor is placed to be in a non-contact state with respect to the supply/convey member and oppose it with a gap of 0.8 mm or less. The diameter of the supply/convey member is set to 23 mm or more.

Abstract: A color image forming apparatus including: a plurality of developing devices for forming a black toner image and a color toner image; an image carrier for carrying toner images; a density detecting device for detecting densities of the black toner image and the color toner image each on the image carrier, the density detecting device having a light emitting element and a light sensitive element; and a controller for the density detecting device; wherein, when detecting a density of the black toner image, the controller controls a drive voltage of the light emitting element so that an amount of received light from a non-image area becomes a first predetermined value; and when detecting a density of the color toner image, the controller controls the drive voltage so that an amount of received light from a non-image area becomes a second predetermined value.