Abstract: A developing apparatus develops a latent image formed on a latent image carrying body with a developer. The developing apparatus includes a developing unit having a means for supplying the developer to the latent image carrying body to develop the latent image on the latent image carrying body and a developer housing for accommodating the developer. A developer storage box stores the developer which is to be supplied to the developing unit. The developer storage box is detachably mounted on the developing unit and has a volume substantially the same as a volume of the developer which can be accommodated in the developer case of the developing unit. The developer in developer storage box is supplied to the developing unit.

Abstract: A developing device for developing an electrostatic latent image with a two-component developer comprises a developer container (46) including a developer-accumulating chamber (50), and a developer-agitating chamber (56) provided above the developer-accumulating chamber. A communication passage (64) is provided between the developer-agitating chamber and the developer-accumulating chamber, and is opened to the developer-agitating chamber to define an overflow opening for the developer. The device also comprises a developer-carrying body (48) provided in the developer-accumulating chamber of the developer container, and the developer-carrying body is exposed to face an electrostatic latent image carrying body, and brings the developer from the developer-accumulating chamber to a facing zone therebetween for development of an electrostatic latent image formed on the electrostatic latent image carrying body.

Abstract: An image forming apparatus including a plurality of developing units each having a developer storage portion for accommodating a developer; a plurality of feeding devices for discharging used developers from the respective developing units; and a single collecting device for collecting the used developers discharged by the respective feeding device.

Abstract: A multicolor electrostatic recording apparatus in which two or more different color toner image are superimposed by respective electrostatic recording units. Each of the electrostatic recording units includes an electrostatic latent image carrier, a developer for developing an electrostatic latent image formed on the carrier with a color toner, and a detector for detecting the density of the developed image on the basis of a detecting mark which is formed on the carrier as a part of the latent image and developed by the developer. A discriminating means compares the density data with an optional desired density value to discriminate whether the density data falls in an allowable range. A controller feed-back controls at least one of parameters for determining the density of the developed image so that the density becomes to be in the allowable range, when the density falls out of the allowable range.

Abstract: To provide a hot roller type thermal fixation device, incorporated in an electrostatic recording apparatus, particularly suitable for the thermal fixation of a multicolor toner image, said apparatus comprising a plurality of electrostatic recording units arranged in series with each other, wherein the surface smoothness of a fixed toner image is maintained at a favorable level for a long period by providing an anti-abrasive treatment onto an elastomeric covering of the heating roller. An elastomeric covering (32b) is applied on the surface of a heating roller (32) of a hot roller type thermal fixation device (22), and an anti-abrasive covering (32c) is further applied on the elastomeric covering.

Abstract: A plurality of electrostatic recording units (Y, C, M and B) are arranged in series along a recording medium moving path. Each electrostatic recording unit includes an electrostatic latent image carrier (48), a developing unit (54, 54') arranged on the upstream side of the electrostatic latent image carrier, and a cleaning unit (60) arranged on the downstream side. The developing unit includes a developer holding container (66) having a developer storage portion (70) and a developer agitating portion (76) located above the developer storage portion. The developer agitating portion is communicated with the developer storage portion via a communicating path (82). The cleaning unit (60) of one of the adjacent electrostatic recording units is disposed adjacent to the developer storage portion (70) of the developer holding container (66) composing a portion of the developing unit (54, 54') of the other electrostatic recording unit.

Abstract: Disclosed is a heat roller fixing apparatus for performing a thermal fixation onto a sheet by rotating a heat roller. This heat roller fixing apparatus comprises a heat roller including a roller body and a plurality of heating members provided in the roller body and a pressurizing member provided in a face-to-face relationship with the heat roller. This heat roller fixing apparatus has a rotation mechanism for rotating the plurality of heating members along an inner periphery of the roller body and a control unit for drive-controlling the rotation mechanism during a standby status for driving the heating members without rotating the roller body. An unevenness in preheating on the surface of the roller body of the heat roller is thereby prevented.

Abstract: A color image forming apparatus which forms a monochromatic toner image or a toner image in a plurality of colors and which can considerably reduce power consumption, while preventing an offset at the time of fixing a toner image. The color image forming apparatus includes a toner image forming device for forming a monochromatic toner image or a toner image in a plurality of colors on a recording medium; first heating device, located on a toner image side of the recording medium for fixing the toner image on the recording medium by heat; second heating device located on an opposite side to the toner image side of the recording medium; and a controller for making an amount of power supply to the second heating device constant and changing an amount of power supply to the first heating device depending on whether the toner image is monochromatic or is in a plurality of colors, while making a set temperature of the first heating device constant.