An image forming apparatus includes an intermediate transfer member bearing a toner image and image forming units arranged side by side, with each image forming unit having a developing device forming the toner image, a magnetic permeability sensor detecting a toner density of a developer in the developing device, and a cleaning unit having a cleaning member which removes toner remaining on an image bearing member and a conductive support member which supports the cleaning member. The apparatus further includes a conductive member facing the magnetic permeability sensor of the most upstream image forming unit and arranged upstream of that image forming unit. The developing device of one of adjacent image forming units is opposed to the cleaning unit of another unit which is arranged downstream and is next to the developing device of the one of the adjacent image forming units.

An image forming apparatus includes a calculation portion calculates an image ratio of the electrostatic image to be formed. A controller controls the developer supply from a developer supplier to the developing unit based on the toner density output of the inductance sensor. An adjustment portion adjusts the density of the toner output from the toner density detection portion to a higher value in a case where the image ratio calculated by the calculation portion is higher than a predetermined image ratio.

A carrier is provided including a core particle and a resin layer coating the surface of the core particle. The resin layer includes fine metal particles, and a detected metal element amount A obtained by X-ray photoelectron spectrometry of the surface of the carrier is in a range of 4.0 atomic %A20.0 atomic % and an average major-axis length B of the fine metal particle exposing from the resin layer is in a range of 100 nmB800 nm.

A developing device includes a developing container, first and second stirring-conveyance members, a developer carrier, a toner concentration sensor, a scraper, and a scraper attachment unit. The second stirring-conveyance member includes a rotation shaft, a first spiral blade to convey developer in an axial direction, and a second spiral blade to overlap a region where the first spiral blade is formed, which is opposite to the first spiral blade in phase, and lower than the first spiral blade in height in a radial direction. An absent region, where the second spiral blade does not exist, is formed in one pitch of the first spiral blade, the one pitch facing the toner concentration sensor. The scraper attachment unit is formed to extend, along a straight line passing through intersection points of the first and second spiral blades and parallel to the rotation shaft, into the absent region.

An image forming apparatus includes first and second image forming portions. A first conveying pipe conveys a first developer discharged from a first developing unit to a collection portion, and a second conveying pipe conveys a second developer discharged from a second developing unit to the collection portion. A first detection unit detects a toner content of the first developer in the first conveying pipe, and a second detection unit detects a toner content of the second developer in the second conveying pipe. The first developing unit can be removed from the image forming apparatus in a state that the first conveying pipe and the first detection unit remain in the image forming apparatus, and the second developing unit can be removed from the image forming apparatus in a state that the second conveying pipe and the second detection unit remain in the image forming apparatus.

A developing device includes a developer bearing member, a developing container which accommodates developer, a conveying screw which conveys the developer accommodated in the developing container, and an inductance sensor which includes a detecting portion which detects magnetic permeability of the developer accommodated in the developing container. The conveying screw includes a rotary shaft, a blade which is spirally formed on an outer circumference of the rotary shaft, and a rib formed to protrude outwardly from the outer circumference of the rotary shaft. The rib is disposed opposite the detection portion with respect to a conveying direction of the conveying screw and is provided with a magnet, with magnetic flux density of the magnet being in the range of 20 mT to 60 mT.

The technology described herein relates to double-stranded ribonucleic acid (dsRNA) compositions targeting the Serpina1 gene, and methods of using such dsRNA compositions to inhibit expression of Serpina1.

An image forming apparatus includes a processing unit, a sensor, and a processor. The processing unit has a developing device using a developer containing two components of a toner and a carrier. The sensor outputs a detection value corresponding to a toner concentration of the developer during operation of the processing unit. The processor performs a process of determining whether a service call to a service person is necessary based on the detection value of the sensor. The processor operates the processing unit at either a high process speed or a low process speed to acquire the detection value of the sensor, before determining whether the service call is necessary. The processor determines the process speed at which the processing unit is to be operated based on the detection value. The processor operates the processing unit at the determined process speed to determine whether the service call is necessary.

An image forming apparatus includes an image bearing member, a developing device configured to develop an electrostatic image formed on the image bearing member into a toner image, and an exchangeable developer container configured to supply the developer into the developing device. A content sensor detects information relating to a toner content in the developing device, and an exchange detecting portion detects an exchanging operation of the developer container. A controller controls a supplying operation for supplying the developer from the developer container to the developing device on the basis of a detection result of the content sensor and executes a developer supplying mode for supplying developer prohibiting an image forming operation. The controller controls the supplying operation so as to permit the image forming operation without executing the developer supplying mode until an amount of formed images reaches a predetermined level.

A developing apparatus includes a developer container, a conveyance portion, a density detection unit, and a projected portion. The conveyance portion includes a shaft portion and a conveying blade. The projected portion is projected from the shaft portion in a radial direction of the shaft portion such that a position of the projected portion overlaps with a detection surface of the density detection unit in an axial direction of the shaft portion. The projected portion is shaped such that a part between both end portions of the projected portion in the axial direction is positioned upstream in a direction of rotation of the conveyance portion than the both end portions.