Abstract: A film photoconductor holding mechanism includes a substantially-cylindrical support having an opening which is shaped so as to have a notch at a part of a circumferential portion of the support in a longitudinal direction thereof. A bar-like photoconductor cap which is operative to engage with the opening of the support is provided. A film assembly is provided and has a peripheral length larger than an outer peripheral length of the support and is installed into the support in a state where the bar-like photoconductor cap is opened and is held in the support by the bar-like photoconductor cap. A guide bar and elastic member is disposed on the film assembly for guiding and tensioning the installation of the film assembly in the support, and a guide groove is defined in the bar-like photoconductor cap and is operative to be engaged with the guide bar.

Abstract: An image forming apparatus includes a base machine; and a mounting device for interchangeably mounting any one of a plurality of different types of photoreceptor units to the base machine. The mounting device includes a print section module detachably mounted on the base machine, with the plural types of photoreceptor units being removably set to the print section module via an interface. The different types of photoreceptor units are different in a mounting structure for mounting a photoconductive layer on base.

Abstract: A cleaning device for a dry electrophotographic device includes a cleaning brush brought into resilient contact with an object to be cleaned such as a photosensitive drum. A cleaning roll rotates while constantly being brought into contact with the cleaning brush and a cleaning blade is pressed against the cleaning roll to clean the cleaning roll. A rotation direction switching mechanism switches the rotation direction of the cleaning brush such that the rotation direction of the cleaning brush when cleaning the object, for example, during the formation of an image, is different from that when the brush is not cleaning the object.

Abstract: A cleaning unit for a xerographic printing machine, or the like. A system for mechanically or electrostatically removing objects, such a toner or paper particles in a printing machine from a photoreceptor or other member to be cleaned, includes a cleaning brush rotating in contact with the member to be cleaned, a cleaning roll brought into contact with the cleaning brush to electrostatically or magnetically remove toner from the cleaning brush, and a cleaning blade supported at the base by a blade holder. The cleaning blade is pressed against the cleaning roll, to remove toner deposited on the surface of the cleaning roll. The cleaning blade is a resilient, thin metal plate.

Abstract: An electrophotographic printing apparatus with a pivotable paper buffer and a pivotable guide member which together, depending on their position in relation to each other, form either a loading configuration or a printing configuration. In the loading configuration, the pivoting end of the buffer is adjacent to the pivoting end of the pivotable guide member to form a horizontal path for the paper to travel between the photosensitive member and the fixing portion. In the printing configuration, the buffer pivots upward away from the guide member so that it is in a position to receive a paper sheet as it is fed by a tractor after being contacted by the photosensitive member.

Abstract: A method of operating an electrographic printing apparatus which employs a reversal development system with a two components developer wherein the bias voltage and the surface voltage are varied in synchronism with each other.

Abstract: An electrophotographic printer in which toner is printed and fused and the paper thereafter folded and stacked. To avoid toner stick a blower blows cooling air between adjacent folded sheets. The blower may be mounted on a horizotnally slidable paper guide. The stacker table may be lowered so that the top of the stack is maintained at the same height or the blower may be moved vertically in response to the output of a sensor detecting the top of the folded stack.

Abstract: In a printing sheet conveying device in which a sheet bearing a toner image is passed through a heating roll and a pressure roll, and which has means for changing the right and left contact pressures of these rolls to correct the meandering movement of the sheet when conveyance of the sheet is started; in which when conveyance of the sheet is started, the contact pressure of the rolls is made higher on one of the right and left sides than on the other side, and in a predetermined period of time the contact pressures on both sides are made equal to each other.

Abstract: A laser printer with a thermal fixing unit comprises: a pair of heat and pressure rolls for pressing a sheet with a developed toner image therebetween to fix the toner image on the sheet; a web immersable with an oil; an oil coater for supplying the oil to the web and pressing the web against the heat roll at at least one point to make the web contact with the heat roll so that the oil is applied from the oil coater onto the surface of the heat roll through the web to thereby prevent occurrence of offset of the toner image; and at least one pressing member provided separately from the oil coater for locally urging the web against the heat roll, the pressing member being located on at least one of before and behind the oil coater.

Abstract: An electrophotographic device has a photosensitive element, an electrifier that forms a uniform electrostatic potential on the photosensitive element, and a light source for irradiating the photosensitive element to obtain an electrostatic latent image that has a reduced potential. A bias potential is applied to the photosensitive element after the latent image is formed, but before it is developed, so that the reduced potential of the latent image can be maintained at a constant level. With constant potentials existing on the photosensitive element, a printed image of high quality is obtained.