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 developer unit of the present invention has an agitating paddle which agitates a developer containing a magnetic carrier and a non-magnetic toner, and a toner is supplied from the toner hopper according to an output of a toner concentration sensor. After an agitation is finished which is performed when the power is turned on, the agitating paddle is periodically operated to agitate the developer. During the agitation, a toner concentration controller shifts a reference level with which the output of the toner concentration sensor is compared from a predetermined level to a higher level and then stepwisely returns it to the predetermined level.

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: An image forming apparatus is disclosed having a main body made of resin formed in a monocoque structure. The main body incorporates the functional components and is formed from separable upper and lower casings. The functional components of the apparatus are held by the casings. A document delivery device is located on the upper part of the upper casing. This delivery device includes a pair of delivery rollers for delivering a document along the top surface of the upper casing with the document held by and between the delivery rollers. The image forming apparatus further includes electrical connections which prevent the upper and lower casings from being separated from one another while electrical power is being supplied to the apparatus.

Abstract: An original-holding cover for use in association with an image formation device comprising an upper unit and a lower unit, the upper unit being rotatably mounted on the lower unit so as to be opened and closed, which comprises a base part rotatably connected to an original platen of the upper unit and an original-holding part which is rotatably connected to the base part. When a thick original is duplicated, the entire surface of the original can be uniformly pressed irrespective of the thickness of the original with the original holding part held in a horizontal position by rotating both the base part and the original-holding part. Furthermore, the base part is removable from the original platen and there is provided a stopper means for preventing disconnection of the base part from the original platen due to the impact of opening the upper unit when dealing with a jam or other trouble.

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.