Abstract: The present invention provides an electrical conductor for an optical system (M13) adapted to be stuck to a unit body (M11) for supporting a fluorescent lamp (M12). The electrical conductor (M13) includes: a base portion (M131) which is disposed in proximity to an outer peripheral surface of a glass tube (M121) of the fluorescent lamp (M12) such that mercury in the glass tube (M121) is diffusible, and which is opposite to the glass tube (M121) throughout the length thereof; and reflection portions (M132, M133) integrally formed with the base portion (M131).

Abstract: A fixing temperature control device according to the present invention is applied to a copying machine. A control section has a warm-up control mode and a normal control mode. In the warm-up control mode, energization to a heater is started in response to the start of copying, while being stopped at the time point where a temperature detected by a heat roller temperature detecting sensor reaches a first off temperature. In the normal control mode, on-off control of the energization to the heater is carried out utilizing a predetermined control temperature as a target subsequently to the termination of the warm-up control mode. The predetermined control temperature is corrected by adding a prescribed correction amount to a reference control temperature.

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 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 device for detecting the life of a process unit which is detachably mounted in an image forming apparatus includes a sensor for detecting the density of the toner in the developing device and a signal detector receiving an output from the sensor and operable to determine whether the output exceeds or is less than a predetermined value during a predetermined time period which starts after a developing roller of the process unit starts rotating. A control is connected to the signal detector and is operable to effect different operating conditions depending on whether the output exceeds or is below the predetermined value, one of the operating conditions being an indication that the life of the process unit has expired and another of the operating conditions being an indication that the life of the process unit is unexpired.

Abstract: A paper sheet material conveying device has a feed roller assembly and a temporary hampering assembly disposed downstream thereof. The sheet material conveying device includes a driven shaft to be rotated by a driving source and a driven roller mounted thereon. The driven roller has an inside diameter larger than the outside diameter of the driven shaft and is mounted rotatably on the driven shaft. When the forward movement of the sheet material fed by the feed roller assembly is hampered by the temporary hampering assembly, the rotation of the driven roller is stopped by the resistance of the sheet material exerted on the driven roller in spite of the rotation of the driven shaft.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of scanning.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of scanning.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of scanning.

Abstract: An electrostatic copying process and apparatus capable of forming copies in at least two different ratios. The formation of a copied image involves exposure scanning of the image of an original document and projecting it on a photosensitive member through an optical device. The change of the ratio of copying is achieved by changing the ratio of projection of the image of the document onto the photosensitive member by the optical device, and also changing the speed of the scanning.