Abstract: An apparatus includes a fuser assembly including a heater member. The heater member includes at least one heating element and at least one temperature sensor to sense a temperature of the heating element. A first power control unit is coupled to the at least one temperature sensor and operative to calculate at least one power level for the at least one heating element based upon at least one set-point temperature therefor and the temperature sensed by the at least one temperature sensor. A second power control unit is coupled to the first power control unit, receives the calculated at least one power level and selects, based upon the calculated power level, at least one actual power level from a stored plurality of predetermined power levels. The second power control unit controls a power for the at least one heating element based upon the selected at least one actual power level.

Abstract: An image forming apparatus includes a plurality of developing devices, each of which includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with a developer, and a developer regulating member for regulating the developer carried on the developer carrying member; a common voltage applying device for applying voltages to the developer regulating members, wherein the voltages are applied to the developer carrying members are variable independently from each other, and when at least one of the voltages varies, the voltage applied by the voltage applying device is capable of being changed.

Abstract: An image forming apparatus includes a main body, an image carrier provided in the main body and configured to retain electrostatic latent images on its surface, and a developing unit including a holding unit holding plural developing devices, rotatably supported by the main body. Further, a driving source is configured to rotate the developing unit and move a desired developing device to a developing position opposed to the image carrier. A stopping member is configured to be moved to an unstopping position unengaged with the holding unit and to a stopping position to stop a one-way direction rotation of the developing unit at an exchanging position for exchanging the developing devices. A backstop member is configured to be moved to a removing position unengaged with the holding unit and to an engaged position engaged with the holding unit to prevent a rotation of the developing unit in a direction opposite the one-way direction rotation.

Abstract: A color image forming apparatus includes a plurality of chargers each provided in a periphery of an image forming body for charging the image forming body; at least two of a plurality of imagewise exposure devices each equally spaced with respect to the image forming body, for imagewise exposing a charged image forming body to form a latent image; and a plurality of developing devices each provided in the periphery of the image forming body to develop the latent image to form a toner image.

Abstract: An endless belt which stays separated from a photoreceptor and is made to press the photoreceptor as required is wound around driving and driven rollers with some slack. When a front sheet-end sensor detects a front end of a sheet, the detection signal activates the driving roller to rotate in a forward or sheet conveying direction while the driven roller is kept in the stopped mode. By this rotation, the slack is canceled so that the endless belt presses the photoreceptor, setting up a sheet conveying mode. When a rear sheet-end sensor detects a rear end of the sheet, the driving roller is turned in the reversed direction. By this operation, the endless belt is loosened to separate from the photoreceptor.

Abstract: A toner replenishing device for a developing device included in an image forming apparatus is disclosed. An engaging member, used to transfer a driving force from an external drive source to the shaft of an agitating member disposed in a toner container, is prevented from being damaged when, for example, the toner container is let fall by accident. The agitating member for agitating toner stored in the toner container is protected from damage when an excessive load acts on the shaft. The toner stored in the toner container is prevented from solidifying and exerting an excessive load on the shaft of the agitating member.