Abstract: A developing device (100) according to the present invention is provided with a housing (102) for holding toner, conveying screws (104, 105) arranged in the housing (2) and each including a rotary shaft (107) and a blade (106) arranged on the rotary shaft (107) for conveying the toner from one end of the rotary shaft (107) toward the other end thereof by the rotation of the rotary shaft (107), and a developing roller (103) provided in the housing with a part of the developing roller (103) being exposed from the housing, and rotatable to obtain the toner conveyed by the conveying screws (104, 105). The conveying screws (104, 105) are constructed, for the efficient agitation of the toner, such that toner pressing forces of the blades (106) differ depending the angle of rotation of the rotary shaft (107).

Abstract: A developing device using a magnetic mono-component developing agent includes a rotary sleeve that accommodates a stationary magnet, and a toner layer thickness regulating member that regulates a thickness of a toner layer formed on the rotary sleeve. The toner layer thickness regulating member includes a blade formed of a plate-like member made of a magnetic material and a magnet attached to the blade on a side upstream in a rotation direction of the rotary sleeve. The magnet is disposed in such a manner that a direction of a magnetic field generated in a portion of the magnet on a side of the rotary sleeve is almost in parallel with the rotation direction of the rotary sleeve.

Abstract: The image forming device of the present invention is able to be configured such that it has an image carrier that carries electrostatic latent image, a rotary type developing unit having a plurality of developing machines that stores toner in the interior thereof and is able to develop the electrostatic latent image by providing toner on the image carrier, and a control unit that is configured to execute a toner discharge process that discharges a portion of toner in the interior of a developing machine mentioned after rotating the developing unit, during a time that an image is not being formed and after a single color image formation using only a developing machine out of the plurality of developing machines.

Abstract: A developing device supplies developer to an electrostatic latent image bearing body of an image forming apparatus. The developing device includes a container housing with an opening in a position opposite to the electrostatic latent image bearing body and stores developer to be supplied to the electrostatic latent image bearing body. A developing roller is rotatably disposed so that a part of the developing roller is exposed from the opening. A regulator is disposed along an axial direction of the developing roller and has a leading end facing the developing roller to regulate the thickness of developer layer on the developing roller. Two holders support the developing roller and the regulator on the container housing. Each holder includes a developing roller support for supporting an end part of the developing roller and a regulator retainer for retaining the regulator on the container housing.

Abstract: An image forming apparatus for forming a color image has developing devices with different color toners. Each developing device has a toner carrier and a layer thickness-controller facing the carrier. Circularity of toner in a particular color is smaller than that of toners in other colors. The layer thickness-controllers of the developing devices containing toners in other colors contact the carrier at a particular linear pressure. Additionally, the coefficient of variance (CV value) of the particle diameter distribution of toner in a particular color may be defined by the formula CV ? ? VALUE = ( STANDARD ? ? DEVIATION ? ? OF ? ? VOLUME - AVERAGE ? ? PARTICLE ? ? DIAMETER ? ? DISTRIBUTION ) ( ARITHMETIC ? ? VOLUME ? - AVERAGE ? ? PARTICLE ? ? DIAMETER ) × 100 and may exceed the CV value of the toners in other colors.

Abstract: A developing device includes a casing, a first mixing conveying screw, and a developer removing unit. The casing is able to store toner. The first mixing conveying screw has a shaft arranged to be able to rotate freely in the interior of the casing, and a spiral in a spiral shape formed on the outer circumference portion of the shaft. The developer removing unit has a plurality of spring members arranged to be lined up in the axial direction corresponding to the spiral pitch of the spiral and are able to contact the spiral, and a retaining member that is retained in the casing and retains the plurality of the spring members.

Abstract: An imaging apparatus includes a toner ejection mode whereby toner stored in a black developing container is completely removed from the developing container by rotating a rotary developing unit at a specific timing and using gravity and the centrifugal force that acts on the toner stored in the black developing container due to this rotation, or using the vibration that acts on the black developing container when the rotation is stopped. In this toner ejection mode, the toner is ejected from the developing container of the rotary developing unit, an image for a single sheet of recording paper is formed on the surface of a photoreceptor drum, and the toner constituting the image transferred onto the surface of an intermediate transfer belt by the photoreceptor drum is then recovered by a belt-cleaning unit.

Abstract: A developing device includes a developing sleeve for supplying toner particles to a latent image area on a peripheral surface of a photoconductive drum while rotating about an axis. The developing sleeve has a permanent magnet therein. Two magnetic members are provided in the developing device and face opposite ends of a peripheral surface of the developing sleeve at a predetermined distance from the developing sleeve. The magnetic members have arc-shaped inner surfaces. A blade is spaced a predetermined distance from a central portion of the peripheral surface of the developing sleeve. The blade adjusts the amount of toner particles supplied to the photoconductive drum. The gap between the arc-shaped inner surface of the magnetic member and the peripheral surface of the developing sleeve gradually increases from upstream to downstream in a rotational direction of the developing sleeve.

Abstract: A developing device (50) includes a developing sleeve (53) for supplying toner particles (T) to a latent image area (22) on a peripheral surface of a photoconductive drum (20) while rotating about a central shaft (534). The developing sleeve (53) has an immovable sleeve magnet (533) therein. Two magnetic members (82) are disposed in opposite end portions of the developing sleeve (53) and are spaced a predetermined distance from the peripheral surface of the developing sleeve. Each magnet member (82) has an arc shape. A magnetic member magnet (83) is mounted in the magnet member (82) and faces a sleeve magnet (533) so that opposite facing portions of the magnetic member magnet (83) and the sleeve magnet (533) have the same polarity. With this construction, toner particles are prevented from leaking from the end portions of the developing sleeve (53).

Abstract: A developing device includes a container for containing toner, a rotatable shaft provided in the container, a spiral shaped blade formed on an outer circumference of the shaft, and a first spiral member for conveying the toner in the longitudinal direction of the shaft by means of rotation. In addition, a toner removing member is provided for removing the toner attached to the first spiral member. Then, by rotation of the first spiral member, the toner removing member is moved in the longitudinal direction of the shaft and the direction that is orthogonal to the longitudinal direction of the shaft so as to be in contact with the surface of the first spiral member. Accordingly, it is possible to adequately scrape the toner off the spiral shaped blade and the shaft, thereby effectively prevent an aggregation of toner from occurring.

Abstract: A developing device (100) according to the present invention is provided with a housing (102) for holding toner, conveying screws (104, 105) arranged in the housing (2) and each including a rotary shaft (107) and a blade (106) arranged on the rotary shaft (107) for conveying the toner from one end of the rotary shaft (107) toward the other end thereof by the rotation of the rotary shaft (107), and a developing roller (103) provided in the housing with a part of the developing roller (103) being exposed from the housing, and rotatable to obtain the toner conveyed by the conveying screws (104, 105). The conveying screws (104, 105) are constructed, for the efficient agitation of the toner, such that toner pressing forces of the blades (106) differ depending the angle of rotation of the rotary shaft (107).