Abstract: A device has a process cartridge that includes a main cartridge accommodating a photosensitive body and a toner cartridge for use in replenis`hing toner as a precondition, is to precisely judge the service life of a photosensitive body and replacement timing of a main cartridge. Whether a predetermined condition is satisfied or not is judged with reference to a recording sheets count value G, a total operation time Tt1 and a toner cartridge related operation time Tx of the photosensitive drum, and a toner replenishing time Ts. In cases where a predetermined condition is satisfied, a message is displayed to urge the user to replace the process cartridge or the toner cartridge. When the toner is used up, the recording operation is inhibited, and an instruction to replace the process cartridge or the toner cartridge is displayed. Consequently, it is possible to accurately replace the photosensitive drum and toner cartridge at their respective adequate replacement timings.

Abstract: The object of the present invention, employing a process cartridge that includes a main cartridge accommodating a photosensitive body and a toner cartridge for use in replenishing toner as a precondition, is to precisely judge the service life of a photosensitive body and replacement timing of a main cartridge. Whether a predetermined condition is satisfied or not is judged with reference to a recording sheets count value G, a total operation time Tt1 and a toner cartridge related operation time Tx of the photosensitive drum, and a toner replenishing time Ts. In cases where a predetermined condition is satisfied, a message is displayed to urge the user to replace the process cartridge or the toner cartridge. When the toner is used up, the recording operation is inhibited, and an instruction to replace the process cartridge or the toner cartridge is displayed.

Abstract: In an image-forming section, a communication device is attached to the top surface of a developing cartridge that is detachably attached to a developing device, and a main body side communication device is attached to a copying machine main body in a manner so as to face the top portion of the communication device. When a loading operation of the developing cartridge to the copying machine main body is carried out, the main body side communication device detects this operation, and sends an electric wave for an electrical supply to the developing cartridge. The communication device transmits individual information of the developing cartridge by means of radio waves, and the main body side communication device receives, demodulates and reads this information. Based upon the results thereof, it makes a judgment as to conformity and suitability of the developing cartridge, and displays the results of the judgement or gives a warning as to the results.

Abstract: An image-forming apparatus is provided with: a rotatable photoreceptor; a charging device for charging the surface of the photoreceptor to a predetermined electric potential. A device for corona discharging, the charging device has a control electrode for controlling the quantity of corona ions that are allowed to reach the photoreceptor. A latent image forming device for forming an electrostatic latent image on the photoreceptor that has been charged by the charging device by use of light irradiation. There is a developing device for developing the electrostatic latent image by using a developer; and a control voltage supply device for supplying a control voltage to the control electrode and for switching the control voltage to a plurality of stages from a low-voltage side to a high-voltage side until the surface electric potential of the photoreceptor has risen to a predetermined electric potential.

Abstract: To solve problems that the amount of reuse toner increases with time recovery of reuse toner is efficiently achieved while forming an image of high quality. In a toner replenishing apparatus, toner recovered by a cleaning unit is conveyed via conveying device and contained in a recovery toner container. When an amount of the recovery toner exceeds a predetermined capacity of the recovery toner container, the recovery toner flows into a fresh toner container over an upper edge of a partition wall. Fresh toner and recovery toner are replenished to a developing unit via a fresh toner replenishing roller and a recovery toner replenishing roller, respectively, and the ratio between fresh toner and recovery toner is selected so that the fresh toner occupies a larger part than the recovery toner. This ratio is controlled on the basis of the cumulative rotation time of a photoconductor drum counted by a counting device.

Abstract: A developing unit and an image forming apparatus includes drive and control mechanisms for the conveyance of collected toner and fresh toner in an uncomplicated structure and an uncomplicated toner supplying roller structure for the reduction in manufacturing cost. Fresh toner and collected toner stored in housing parts of a toner housing are discharged from an outlet via openings formed in a partitioning member for forwarding to a developing section by a toner supplying roller disposed to confront the outlet. The toner supplying roller is provided in common to fresh toner and collected toner. The toner supplying roller includes a single rotary shaft and a plurality of composite members which are fit into the rotary shaft. Each of the composite members has a cylindrical hollow body and a cylindrical elastic body which is fit onto the outer peripheral surface of the hollow body. The composite members are disposed correspondingly to the housing parts.

Abstract: The invention is characterized by efficiently and quickly loosening an aggregation of toner material formed in a toner cartridge. A toner cartridge has an L-shaped toner agitating member disposed in a main body thereof having a discharge port for feeding toner at the front surface of the main body. Since the toner agitating member is supported so as to pivot like a conical pendulum, a support pin fixed to a bottom surface of the main body passes through a through hole having a greater diameter than that of the support pin. The support pin has an engagement portion attached thereto for prevention of disengagement of the toner agitating member therefrom. A plate-like portion of the toner agitating member defines an agitating plate, a distal end of which extends toward the discharge port of the main body.

Abstract: An image forming apparatus has a developer container, a development device for developing a latent image formed on a surface of a photoreceptor drum by supplying toner to the latent image, and an agitation roller for supplying toner to the development device and agitating the toner in the developer container. The development device and the agitation roller are installed in the developer container. Moreover, the image forming apparatus includes a flying toner detecting device for detecting an amount of toner flying from the development device, and a control unit for controlling various developer operations such as the toner related agitating operation of the agitation roller, toner supply amount, etc. in response to a result of a detection performed by the flying toner detecting device. This structure prevents the toner from flying from the development device.

Abstract: An image forming apparatus has an arrangement wherein a main charger includes a charger line corresponding to a region within a reference range on a surface of a photoreceptor and second charger lines corresponding to regions outside the reference range, and the first charger line within the reference range and the second charger lines outside the reference range are driven independently. The reference range is set on the surface of the photoreceptor as a width of a transported sheet which is most frequently used. In a processing control, in the case where toner patch density within the reference range becomes higher than toner patch density outside the reference range, an applied voltage with respect to the charger line within the reference range is increased relatively higher than an applied voltage with respect to the charger lines outside the reference range, thus uniformalizing the toner density with respect to the entire surface of the photoreceptor drum.

Abstract: The image forming apparatus of the invention controls the toner density by any one of the following configurations: by correcting the toner density of the developer in association with the agitation total; by controlling a process parameter so that the density of a toner patch formed on the photoreceptor corresponds to a prescribed density value and determining that developing performance of the developer is improved and canceling the toner density correction when the process parameter reaches the prescribed value; by changing the toner density reference value when the variation as to the charger output is equal to or greater than a first predetermined value and maintaining the changed toner density reference value until the variation of the charger output again becomes equal to or greater than the first predetermined value; or by prohibiting toner supply for a constant duration to prevent excessive toner supply if time from the end of the last operation of the developing unit to the start of a next operation

Abstract: CPU is designed to create toner patches on the surface of the photoreceptor drum and pick up the detected data of the density of the toner patches by a photosensor. CPU calculates a correcting value .DELTA.Vg of the charger output in accordance with the picked up detected data, and compared the corrected charger output Vg with (Vgs+.alpha.) and (Vgs-.alpha.). If the corrections in the same direction are repeated in a row, k.beta. (where 0<k<1) is added to or subtracted from the toner density reference value. When the direction of the correction for the toner concentration reference value to be made is opposite that of the previous one, the absolute value of the correcting value for the current correction is set to be the absolute value of the previous one.

Abstract: In order to effectively perform image stabilization by control of retaining initial characteristics of a photosensitive body, if correlation between initial and aged values corresponding to bright and dark part signals of the photosensitive body is such that a variation between the initial and aged values of the dark part signal (dark .DELTA.) is greater than a variation between the initial and aged values of the bright part signal (bright .DELTA.), an image stabilizer, first, controls a charging characteristic of the aged values by changing a charging output to the photosensitive body so that the bright .DELTA. and the dark .DELTA. are equal to each other. Next, the image stabilizer makes the aged characteristics of the photosensitive body virtually identical to the initial characteristics by changing an exposure output so that the aged and initial values of the dark part signal become equal to each other.