Abstract: A mode controller outputs a characteristic value according to a DC component of a developing current measured by an ammeter at a predetermined measurement timing. The measurement timing is defined as a timing at which a non-image forming region of a surface of a photosensitive drum is located opposite to a developing roller in the entirety of an axial direction and an electric field in a direction in which a toner moves from the photosensitive drum toward the developing roller by a potential difference between a surface potential of the photosensitive drum and the DC component of a developing bias is formed in a developing nip part. A determining section determines an execution timing for a charge amount acquisition operation according to the characteristic value output by the mode controller.

Abstract: An image forming apparatus includes an acquisition section, a dividing section, and a data generator. The acquisition section acquires image data on a cord image representing an identification code containing specific information. The dividing section divides the image data into first image data representing a first image and second image data representing a second image so that an image to be formed on a recording medium according to the code image is divided into the first image and the second image. The data generator generates printing data containing: the first image data on the first image to be formed on a first side or a second side of a recording medium; and the second image data on the second image to be formed on the second side or the first side of the recording medium.

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and a density change amount of the measurement toner image based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires the charging amount of the toner based on the acquired tilt of the measurement straight line and the reference information in the storage unit.

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit performs a charging amount acquisition operation for forming a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias with a potential difference in a direct current voltage between the developing roller and the image carrier being kept constant, acquiring a tilt of a measurement straight line representing a relationship between the change amount of the frequency and a density change amount of the measurement toner image, and acquiring the charging amount of the toner based on the acquired tilt of the measurement straight line and the reference information in the storage unit.

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias with the potential difference in the direct current voltage between the developing roller and the image carrier being kept constant, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and the density change amount of the measurement toner image, based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires a charging amount of the toner included in the measurement toner image formed on the image carrier based on the acquired tilt of the measurement straight line and the reference information in the storage unit according to the toner density detected by the toner density detecting unit.

Abstract: A mode controller outputs a characteristic value according to a DC component of a developing current measured by an ammeter at a predetermined measurement timing. The measurement timing is defined as a timing at which a non-image forming region of a surface of a photosensitive drum is located opposite to a developing roller in the entirety of an axial direction and an electric field in a direction in which a toner moves from the photosensitive drum toward the developing roller by a potential difference between a surface potential of the photosensitive drum and the DC component of a developing bias is formed in a developing nip part. A determining section determines an execution timing for a charge amount acquisition operation according to the characteristic value output by the mode controller.

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit performs a charging amount acquisition operation for forming a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias with a potential difference in a direct current voltage between the developing roller and the image carrier being kept constant, acquiring a tilt of a measurement straight line representing a relationship between the change amount of the frequency and a density change amount of the measurement toner image, and acquiring the charging amount of the toner based on the acquired tilt of the measurement straight line and the reference information in the storage unit.

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias with the potential difference in the direct current voltage between the developing roller and the image carrier being kept constant, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and the density change amount of the measurement toner image, based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires a charging amount of the toner included in the measurement toner image formed on the image carrier based on the acquired tilt of the measurement straight line and the reference information in the storage unit according to the toner density detected by the toner density detecting unit.

Abstract: An image forming apparatus includes a storage unit and a charging amount acquisition unit. The charging amount acquisition unit forms a measurement toner image on the image carrier while changing the frequency of the alternating current voltage of the development bias, acquires a tilt of a measurement straight line representing a relationship between the change amount of the frequency and a density change amount of the measurement toner image based on the change amount of the frequency and a result of detecting density of the measurement toner image in the density detecting unit, and acquires the charging amount of the toner based on the acquired tilt of the measurement straight line and the reference information in the storage unit.

Abstract: A developing device includes a developing roller, a conveyor roller, a developer stirring unit and a development bias applying unit. The developing roller is arranged to face a photoconductive drum at a predetermined developing position and supplies the toner. The conveyor roller is arranged to face the developing roller at a predetermined facing position and supplies the developer to the developing roller. The development bias applying unit applies development biases to the first sleeve of the developing roller and the second sleeve of the conveyor roller during a developing operation of developing the electrostatic latent image on the photoconductive drum with the toner. The development bias applying unit applies the development biases such that a shifting electric field to move the toner on the first sleeve of the developing roller toward the second sleeve of the conveyor roller is formed at the facing position during the developing operation.

Abstract: A developing device includes a developing roller, a conveyor roller, a developer stirring unit and a development bias applying unit. The developing roller is arranged to face a photoconductive drum at a predetermined developing position and supplies the toner. The conveyor roller is arranged to face the developing roller at a predetermined facing position and supplies the developer to the developing roller. The development bias applying unit applies development biases to the first sleeve of the developing roller and the second sleeve of the conveyor roller during a developing operation of developing the electrostatic latent image on the photoconductive drum with the toner. The development bias applying unit applies the development biases such that a shifting electric field to move the toner on the first sleeve of the developing roller toward the second sleeve of the conveyor roller is formed at the facing position during the developing operation.

Abstract: An image forming apparatus uses a developer containing toner particles. The image forming apparatus includes a toner-particle bearing member for bearing the toner particles. Each toner particle includes a toner core containing a binder resin and a shell layer coating a surface of the toner core. The toner-particle bearing member includes a substrate and a surface layer coating a surface of the substrate. The surface layer and the shell layer are each formed from a resin containing a thermosetting resin.

Abstract: An image forming apparatus uses a developer containing toner particles. The image forming apparatus includes a toner-particle bearing member for bearing the toner particles. Each toner particle includes a toner core containing a binder resin and a shell layer coating a surface of the toner core. The toner-particle bearing member includes a substrate and a surface layer coating a surface of the substrate. The surface layer and the shell layer are each formed from a resin containing a thermosetting resin.