What is provided is an image forming apparatus in which longitudinal end portions of a developer bearing region or longitudinal end portions of an opening are respectively located outside longitudinal end portions of a transfer bias applicable region.

An image forming apparatus includes: a photosensitive drum; a magnetic roller; a transfer belt; a drum cleaning roller for collecting toner on the photosensitive drum and discharging collected toner to the photosensitive drum; a belt cleaner; a waste toner accommodating unit; and a controller configured to perform a printing operation for forming an image on a sheet and a cleaning operation for cleaning the drum cleaning roller. The controller is configured to perform: when performing the printing operation, collecting toner on the photosensitive drum using the drum cleaning roller; and when performing the cleaning operation, discharging the toner on the drum cleaning roller collected in the collecting to the photosensitive drum; transferring the toner on the photosensitive drum onto the transfer belt; and collecting the toner on the transfer belt using the belt cleaner so that the collected toner is accommodated in the waste toner accommodating unit.

An image forming device includes a communication device that communicates with a wireless tag, and an image former that forms a developer image on a surface of a photoreceptor via a transfer belt. The image former includes a transferor that transfers the developer image from the transfer belt to a medium, and a transmitter configured to transmit the medium to the transferor. The image forming device includes a controller communicably coupled to the image former. The controller includes a processor that controls an operation of the transmitter. When communication with the wireless tag by the communication device is not ended, the controller controls the transmitter to stop the medium, and after the developer image has been transferred to the transfer belt by the image former and passes a transfer position of the transferor, transmit the medium preventing the developer image on the transfer belt from being transferred to the medium.

A developing device includes a developer carrying member, a first chamber for feeding developer to the developer carrying member, a second chamber for collecting developer from the developer carrying member, and a feeding member provided rotatably in the first chamber for feeding the developer. The feeding member includes a rotation shaft and a spiral blade wound helically in a developer feeding direction. The feeding member includes a first region corresponding to a developer coating region of the developer carrying member, a second region provided downstream of the first region with respect to a feeding direction of the feeding member, and a third region provided upstream of the first region. An average feeding power per unit driving time of the feeding member is set at a smaller value in the first region than in the second region and in the third region.

An image forming apparatus includes a second acquisition processing portion and a third acquisition processing portion. The second acquisition processing portion acquires a first toner image forming condition of a toner image forming portion. The third acquisition processing portion acquires, based on the first toner image forming condition acquired by the second acquisition processing portion, a relational expression that indicates a relationship between a second toner image forming condition of the toner image forming portion and a toner concentration of a specific toner image that is formed by the toner image forming portion. Further, the third acquisition processing portion uses specific expressions that respectively correspond to a plurality of coefficients included in the relational expression to calculate the plurality of coefficients corresponding to the first toner image forming condition acquired by the second acquisition processing portion.

A developing device includes a storing unit that stores an electrostatic charge image developing toner, and a developer holding member that is provided to have a gap with an image holding member and holds the toner on a surface, wherein the developing device develops an electrostatic charge image formed on a surface of the image holding member by the toner on the developer holding member through a non-contact development to form a toner image, and wherein the toner has a sea and island structure of a sea portion containing a binder resin and an island portion containing a release agent, a maximum frequent value in distribution of the eccentricity B of the island portion is from 0.75 to 0.95, and a skewness in the distribution of the eccentricity B is from 1.10 to 0.50, and the eccentricity B is defined in the specification.

An image forming apparatus includes: an electrophotographic photoreceptor; a charging device that charges a surface of the electrophotographic photoreceptor; an electrostatic charge image-forming device that forms an electrostatic charge image on the charged surface of the electrophotographic photoreceptor; a developing device that stores a developer containing a toner, and supplies the developer to develop the electrostatic charge image on the surface of the electrophotographic photoreceptor into a toner image, wherein the developing device has: a first developing member that is disposed to face the electrophotographic photoreceptor, holds the developer, and transports the developer to a development region; a second developing member that is disposed downstream of the first developing member in a rotation direction of the electrophotographic photoreceptor so as to face the electrophotographic photoreceptor, holds the developer, and transports the developer to a development region; a first power source that applies, to the first developing member, a developing voltage obtained by superimposing an AC voltage on a DC voltage; and a second power source that applies, to the second developing member, a developing voltage obtained by superimposing an AC voltage on a DC voltage; a transfer device that transfers the toner image on the surface of the electrophotographic photoreceptor to a surface of a recording medium; a fixing device that fixes the toner image to the surface of the recording medium; and a control device that acquires image information regarding the toner image, and controls at least one of the first power source and the second power source according to the image information such that the AC voltage of the developing voltage applied to the second developing member has a lower frequency than the AC voltage of the developing voltage applied to the first developing member.

An image forming apparatus incudes a first conveyance guide portion having a first roller, a first engagement portion, and a second engagement portion, and includes a second conveyance guide portion having a second roller, a first engaged portion, and a second engaged portion. The first and second conveyance guide portions form a conveyance path where the first and second rollers convey a sheet. The second conveyance guide portion moves so that engagement between the second engagement portion and the second engaged portion is released and relative positioning between the second and first conveyance guide portions is released. When the first engagement portion and the first engaged portion engage each other and the relative positioning between the second and first conveyance guide portions is released, the second conveyance guide portion pivots in an opening direction relative to the first conveyance guide portion so that the conveyance path is opened.

An image forming apparatus includes: an electrophotographic photoreceptor; a charging device that charges a surface of the electrophotographic photoreceptor; an electrostatic charge image-forming device that forms an electrostatic charge image on the charged surface of the electrophotographic photoreceptor; a developing device that stores a developer containing a toner, and supplies the developer to develop the electrostatic charge image on the surface of the electrophotographic photoreceptor into a toner image, wherein the developing device has: a first developing member that is disposed to face the electrophotographic photoreceptor, holds the developer, and transports the developer to a development region; a second developing member that is disposed downstream of the first developing member in a rotation direction of the electrophotographic photoreceptor so as to face the electrophotographic photoreceptor, holds the developer, and transports the developer to a development region; a first power source that applies, to the first developing member, a developing voltage obtained by superimposing an AC voltage on a DC voltage; and a second power source that applies, to the second developing member, a developing voltage obtained by superimposing an AC voltage on a DC voltage; a transfer device that transfers the toner image on the surface of the electrophotographic photoreceptor to a surface of a recording medium; a fixing device that fixes the toner image to the surface of the recording medium; and a control device that acquires image information regarding the toner image, and controls at least one of the first power source and the second power source according to the image information such that the AC voltage of the developing voltage applied to the second developing member has a lower frequency than the AC voltage of the developing voltage applied to the first developing member.

An image forming apparatus includes a developing device including a developing roller, a supply roller, and a conductive roller. During image formation, a bias is applied to each of the supplying roller, the developing roller, and the conductive roller in a state in which each of the supplying roller, the developing roller, and the conductive roller is rotationally driven. During the image formation, a polarity of a first potential obtained by subtracting a DC potential of the developing roller from a DC potential of the supplying roller is the same as a normal charge polarity of the toner, and a polarity of a second potential obtained by subtracting the DC potential of the developing roller from a DC potential of the conductive roller is the same as the normal charge polarity of the toner.