Abstract: An image forming apparatus includes a casing 2 and a process cartridge 20, which is mounted removably in the casing. A powder retaining box 53 is supported pivotally by the bottom of the process cartridge 20, and supports a pinch roller 52 for contacting with a sheet of paper 3 to collect paper powder from it. The retaining box 53 has an opening through which the collected powder enters it. The pinch roller 52 substantially closes the box opening, and prevents the paper powder in the retaining box 53 from scattering out when the process cartridge 20 is dismounted from the casing 2. If the a retaining box 53 were fixed to the process cartridge 20, and the pinch roller 52 moved relative to the retaining box when the process cartridge is dismounted, paper powder might scatter out of the retaining box.

Abstract: A direct-current power source is connected, via a diode, to an electrically conductive brush, which makes contact with the surface of a photosensitive drum to remove paper dust deposited thereon. Upon application of a bias voltage by the direct-current power source to the conductive brush, the conductive brush collects paper dust physically as well as electrically. The diode prevents current flow from the conductive brush to the direct-current power source, and thus the paper dust collected by the conductive brush will not return to the photosensitive drum.

Abstract: In an image forming apparatus, a brush member is formed from a brush made from acrylic resin that has not been subjected to conductivity-enhancing processes. The brush member is attached to a conductive plate. A resistor is provided in series with the conductive plate and a fixed power source. The fixed power source applies a predetermined high voltage to the conductive plate.

Abstract: An image forming apparatus includes a casing 2 and a process cartridge 20, which is mounted removably in the casing. A powder retaining box 53 is supported pivotally by the bottom of the process cartridge 20, and supports a pinch roller 52 for contacting with a sheet of paper 3 to collect paper powder from it. The retaining box 53 has an opening through which the collected powder enters it. The pinch roller 52 substantially closes the box opening, and prevents the paper powder in the retaining box 53 from scattering out when the process cartridge 20 is dismounted from the casing 2. If the retaining box 53 were fixed to the process cartridge 20, and the pinch roller 52 moved relative to the retaining box when the process cartridge is dismounted, paper powder might scatter out of the retaining box.

Abstract: A partition wall for separating a developing chamber from a toner agitating chamber in an electrostatic developing device includes a high wall portion confronting a toner discharge opening of a toner cartridge, and low wall portions formed on either side of the high wall portion. Toner is discharged from the toner discharge opening of the toner cartridge into the agitating chamber. Toner is then sent over the partition wall and into the developing chamber by rotation of an agitator in the agitating chamber. Toner in the central portion of the agitating chamber goes over the high wall portion, and toner in the side portions of the agitating chamber goes over the low wall portions. Accordingly, a uniform amount of toner is supplied to all points along the length of a developing sleeve in the developing chamber, and hence to all points along the length of a photosensitive drum confronting the developing sleeve.

Abstract: A developing unit including a developing chamber provided with a rotatable developing sleeve and a magnet roller capable of rotating inside the developing sleeve, and a first agitator for agitating a developer, and an agitation chamber provided with a second agitator for supplying a magnetic toner to the developing chamber. A restriction member, formed of a magnetic material, is suspended between the developing chamber and the agitation chamber. A free end of the restriction member extends toward the first agitator and a toner supply slit is formed below the lower, or free, end of the restriction member so that the magnetic toner supplied by the second agitator in the agitation chamber is conducted to the first agitator without direct contact with the developing sleeve. As a result, the magnetic toner can be supplied and agitated positively and stably.

Abstract: A developing unit has an initial developer container containing an initial developer composed of toner and carrier, joined pivotally with a pin to a toner container having an initial developer inlet opening and defining a developing chamber. Provided in one wall of the developer container is an initial developer outlet opening. In an initial state, the initial developer outlet opening is closed by one wall of the toner container, so that the mixed toner contained in the initial developer container will not spill. When a toner supply cartridge is inserted in the developing unit, the toner supply cartridge turns the initial developer container downward on the pin to a position where the initial developer outlet opening of the initial developer container coincides with the initial developer inlet opening of the toner container. This allows the initial developer contained in the initial developer container to flow into the developing chamber.

Abstract: The present invention relates a particle carrying device wherein a carrying passage can be detachably installed onto a toner particle collection unit for storing wasted particles, without dropping the particles. According to the particle carrying device, when the carrying passage is attached onto a particle container, a shutter provided on the carrying passage is moved. Then, a guide member stored in the carrying passage is moved and an opening provided in the carrying passage is opened. Noteover, as a carrying auger rotatably supported in the carrying passage rotates, the waste particles are carried toward the particle container through the opening. On the other hand, when the carrying passage is detached from the particle container, the guide member is moved back into the carrying pipe, and the opening is shut. Further, the shutter moves so as to shield the opening and maintain the guide member in the closed position, so that the particles are prevented from dropping out of the opening.

Abstract: In a printer capable of developing a beautiful image even if waste toner particles are utilized repeatedly for development, residual magnetic toner particles on a photosensitive drum are collected in a cleaning device and returned to a development device by a collecting auger and a carrier auger through a toner particle carrying path. In the development device, the magnetic toner particles are carried into a development area for subsequent developing by a developing sleeve. Just before the development area, toner particles and additives on the toner surface which are not suitable for development contained in the collected waste toner particles are selectively collected by a bias applying roller which is provided between the developing sleeve and the photosensitive drum.

Abstract: One unit type processing unit to be assembled in a laser printer for facilitating replacement work. The processing unit houses therein a photosensitive drum with a part being exposed, a charging unit, a developing unit and cleaning unit. The processing unit is also provided with a flexible protective cover for covering the exposed area of the photosensitive drum when an upper frame of the laser printer is opened. The protective cover can be rolled into a compact configuration and is positioned in a dead space at a position beside the exposed area when the cover is moved away from the exposed area and when the upper frame is closed for printing operation. The rolled cover is stretchable to cover the exposed area when the upper frame is opened.

Abstract: An integral type processing unit has a photosensitive drum, a developing unit for forming a developer toner image on the photosensitive drum, and a cleaning unit for scraping off residual toners from the drum. The developing unit does not have sufficient internal volume for accumulating therein the developer toners whose amount meet with the service life of the other components. Therefore, toner containers are replaceably attached to the developing unit for supplementing the developer toners therein. In order to limit the replacement times of the toner containers, each of the toner containers are provided with a segment separable therefrom. Further, a receiving segment is provided at the developing unit engageable with the separable segment. The receiving segment has a predetermined number of receiving portions. If all receiving portions are filled with the separable segments, it becomes no longer possible to further replace the toner container with a new container.