Abstract: The present invention has been made to provide an image forming apparatus capable of suppressing reverse charging caused by a transfer electric field to thereby suppressing memory image level to a lower level without providing a charge eliminating unit. In am image forming apparatus according to the present invention, a controller 191 increases and decreases a transfer current from a transfer roller 23 in accordance with the rise and fall of setting values to be set of the background potential of a photoconductor drum 10 and developing bias potential of a developing unit 18. By increasing and decreasing the setting value of the transfer current as described above, it is possible to suppress memory image level (residual image level) that can be caused when the setting values of the background potential of the photoconductor drum 10 and developing bias potential are decreased.

Abstract: A cleaning device in an image forming apparatus, which performs cleaning, includes a roll-shaped electrically conductive brush grounded via a varistor (non-linear resistor element), a flicker metal rod which is put in pressure contact with the electrically conductive brush and connected to have a potential equal to a potential of the electrically conductive brush, and a cleaning blade formed of an elastic material.

Abstract: A microcomputer processes count data counted by a CPU counter, and accumulates it in a RAM. The microcomputer always accesses the count data accumulated in the RAM and compares it with preset count data. Based on the comparison result, the microcomputer controls the rotation speed of a drive motor for a transfer belt.

Abstract: A cleaning device in an image forming apparatus, which performs cleaning, comprises a roll-shaped electrically conductive brush grounded via a varistor (non-linear resistor element), a flicker metal rod which is put in pressure contact with the electrically conductive brush and connected to have a potential equal to a potential of the electrically conductive brush, and a cleaning blade formed of an elastic material.

Abstract: A microcomputer processes count data counted by a CPU counter, and accumulates it in a RAM. The microcomputer always accesses the count data accumulated in the RAM and compares it with preset count data. Based on the comparison result, the microcomputer controls the rotation speed of a drive motor for a transfer belt.

Abstract: An image forming apparatus includes an image carrier on which surface a developer image is formed, a charger to transfer a developer image on an image receiving medium from the image carrier and after transferring the developer image, give corona electric charge to a second surface of the image receiving medium being conveyed with its first surface brought in contact with the developer image on the developer image on the image carrier so as to separate the image receiving medium from the image carrier, a counter to count the number of the image receiving medium on which the developer image is transferred and formed thereon, and a voltage applying unit to apply a voltage to the charger. Further, the image forming apparatus includes a controller for increasing voltage being applied to the charger by the voltage applying unit corresponding to the increase in the number of the image receiving medium counted by the counter.

Abstract: As a peeling device for peeling off a paper from a photosensitive drum after completing the transfer of an image, a peeling charger and a sucking fan are used jointly and the sucking wind velocity level of the sucking fan can be controlled by switching it with a controller. With the increase in thickness of a paper, the sucking fan is switched and controlled for reducing a wind velocity level of the sucking fan. Further, in the continuous copying, the sucking fan is switched and controlled so as to reduce a sucking wind velocity level until the peeling of the leading edge of a succeeding paper is started after peeling the leading edge of a current paper. Thus, a sucking wind velocity of the sucking fan is minimized when peeling a paper from the photosensitive drum.

Abstract: An image forming apparatus includes a developing device to form a developer image by developing an electrostatic latent image formed on an image carrier by developing using a developer, a transfer device to transfer a developer image formed on an image carrier, a fixing device to fix a developer image transferred on an image receiving medium, and a conveyor guide 7 arranged so that the image receiving medium with a developer image transferred thereon to guide from the transfer device toward the fixing device. The conveyor guide has contact portions made of a material that is charged to the same polarity as the developer on the image receiving medium as a result of the friction with the image receiving medium.

Abstract: An image forming apparatus includes a developing device for developing an electrostatic latent image formed in a prescribed region on an image carrier corresponding to an original document with a charged developer to form a developer image on the image carrier, a transfer charger for transferring the developer image onto an image receiving medium from the image carrier, and a pre-transfer charger for applying an electric charge having the same polarity as that of the charged developer to the image carrier before transferring the developer image onto the image receiving medium. The apparatus further includes a controller for controlling the pre-transfer charger so that the electric charge is applied only to a given area extending from a front end of the prescribed region on the image carrier on which the developer image is formed, the given area smaller than the prescribed region.

Abstract: An image forming apparatus includes a transfer charger for electrostatically transferring a developing agent image formed on a photoconductive drum onto a paper sheet at a transfer position, and a separation charger for electrostatically separating the paper sheet from the drum. A convey guide is fixed to the separation charger so as to guide the paper sheet separated form the drum in a predetermined direction. The convey guide is formed of a material which is to be charged in a polarity opposite to a charge polarity of the developing agent on the paper sheet upon triboelectric charging between the convey guide and the paper sheet.

Abstract: A lubricant for reducing friction produced between a cleaning device and a photoconductor both assembled in a copying apparatus includes an abrasive agent having an average grain diameter of 0.5 .mu.m to 9.0 .mu.m. The abrasive agent comprises a main chemical component of material which does not change the developing characteristics of a developer used in an electrostatic copying process and which refines the scratches produced on the surface of the photoconductor due to the contact between the developer and the photoconductor during a long period of time.

Abstract: A toner density detecting device is provided with a coil buried in a housing and a cover member provided on one end of the coil to prevent the developing agent from touching the coil. The cover member has a front end portion provided near the surface of the housing and extending along the developing agent flowing direction and an apex portion at the back of the front end portion with respect to the direction. The apex portion projects deeper into the developing agent than the front end portion. An edge connecting the front end portion and the apex portion extends in the direction to cross the central axis of the coil. A pair of faces extending in the direction on either side of the edge are gradually declined from the edge toward the surface of the housing.