Abstract: An image forming apparatus having components which are secured and supported by a resin apparatus body. The body if formed of mutually separable upper and lower casings, which are coupled in shiplap style. At least the upper casing is formed of a monocoque construction, and the lower casing may be formed of a monocoque construction as well.

Abstract: A paper feeding device of an image forming apparatus having a paper feeding roller for feeding, one by one, paper pieces stacked in a paper feeding tray. Disposed at the main body of the image forming apparatus are (i) a placing member on which the stacked paper pieces are placed such that the tips thereof are ready for feeding, (ii) a biasing member for upwardly biasing the placing member, (iii) a pair of pawl members for separating, one by one, the stacked paper pieces, and (iv) a pushing-down member for pushing down the placing member as necessary. Against the biasing member, the pushing-down member pushes down the placing member, thus forming a space for setting the paper pieces between the placing member and the pawl members. The stacked paper pieces are inserted into the space through a paper feeding opening. When the pushing-down operation of the pushing-down member is released, the biasing member causes the placing member to be pushed up.

Abstract: A sheet delivery mechanism includes a pair of delivery rollers which deliver a sheet along a sheet delivery passage of a sheet treatment apparatus for predeterminately treating the sheet, a sheet halting member for halting the sheet, and a pinching force adjusting member. The pinching force adjusting member adjusts the delivery rollers to place them into a first state where the sheet pinching force of the delivery rollers is relatively small so that the delivery rollers can slip on the halted sheet and into a second state where the sheet pinching force is relatively great so that the sheet can be delivered in the case where a sheet halt is released for delivery.

Abstract: An image forming apparatus includes an image forming unit for forming and transferring an image of a document to a copy sheet, fixing unit including a fixing roller for fixing the document image to a copy sheet while transporting it, a heater for heating the fixing roller, and heater control unit for turning on and off the heater at specified timings so as to increase and maintain temperature of the fixing roller to and in a predetermined steady-state temperature range whose upper limit is a fixing temperature, the copy sheet being heated by the fixing roller having temperature of about the predetermined fixing temperature while transported, whereby the document image transferred to the copy sheet is fixed thereto, and control unit for controlling the heater control unit to control the heater within a copying period during which a copying operation is completed. The heater control unit on-off controls the heater only during the copying operation.

Abstract: An image forming apparatus comprises a photoreceptor, a developing roller for forming a layer of developer on a surface thereof to supply toner to the photoreceptor at a developing position, a bias supply for applying bias voltage between the developing roller and a ground, a conductive line for electrically connecting the developer layer with the ground, a detector for detecting toner density of the developer layer based on an amount of electric current flowing through the conductive line, and a voltage controller for preventing surface voltage of the developer layer from falling below a predetermined level despite the electric current flowing into the conductive line at least during a developing operation. Accordingly, there can be reliably prevented formation of fog on a copy because the surface voltage of the developer layer is maintained above the specified level at least during the developing operation.

Abstract: An image forming apparatus includes a main body having an image forming device, a document table for holding the document, the table being movable reciprocatingly to the left and right sides of the apparatus when viewed from front over an upper surface of the main body, a drive device for moving the document table, and a movement control device for mechanically executing at least one operation of switching a moving direction of the document table and locking the document table in a predetermined position. Accordingly, there can be obviated the need for providing expensive electronic parts for switching the moving direction of the document table, stopping and locking the document table. Therefore, the image forming apparatus can be manufactured at lower costs.

Abstract: A paper pressing device for an image forming apparatus including an intermediate tray for temporarily holding a sheet of copy paper in the course of conveying the sheet of copy paper from a discharging side of the image forming apparatus to a feeding side of the image forming apparatus, a conveying path changer pivotably provided above the intermediate tray for changeably providing a first position of permitting a sheet of copy paper smaller than a predetermined size to move over the conveying path changer, and a second position of permitting a sheet of copy paper larger than the predetermined size to move under the conveying path changer, a pressing device attached to the conveying path changer and made of resilient material, the pressing means being pressable on a surface of the intermediate tray when the conveying path changer is set in the second position.

Abstract: An apparatus for electrostatic latent image development having two or more units for multicolor development provided around a photoreceptor. Each unit has a developer feed controller for feeding developer to the developing section having a developing roller facing the photoreceptor drum and for shutting off the feeding and has a doctor blade in the feed up-stream in turning direction of the developing roller. Developer is applied to the developing section when development is performed by displacement of the developer feed controller and is shut off when the developing unit is not used for development.