Abstract: In an image forming apparatus comprising a charging section, an exposure section, a developing section, a transfer section, a peeling section, a cleaning section including a cleaning blade, and a fixing section, the cleaning blade is composed by dispersing 15 parts by weight through 33 parts by weight of fluorine resin particulate and secondary particles thereof into 100 parts by weight of a synthetic resin of a base material and, on a surface of the cleaning blade 16a, and a number of the secondary particles of the fluorine resin particulate having a particle diameter of 0.5 ?m or more existing in unit area of 100 ?m2 is made to be 50 or less.

Abstract: An image forming apparatus includes a toner image forming section including a developing device having a developer tank for storing a two-component developer, a transfer section, a fixing section, a recording medium feeding section, and a discharging section. The image forming apparatus further includes a toner concentration detecting section for detecting the toner concentration in the developer tank, a printing speed switching section, a toner concentration calculating section for correcting a detection result obtained by the toner concentration detecting section according to a speed of printing to calculate the toner concentration, and a toner replenishment control section for replenishing the toner into the developer tank according to a calculation result by the toner concentration calculating section.

Abstract: An image forming apparatus of the present invention includes main control section for controlling the charging control section and the development bias control section so that a potential difference between the photoconductor potential and the development bias potential in developer discharge from the development section is smaller than that in the image forming. Therefore, even when an amount of developer in the development section decreases due to developer discharge, increase of beads-carry-over onto the photoconductor from the development section can be prevented. Accordingly, damage to the photoconductor or image errors due to incomplete cleaning that are caused by beads-carry-over can be prevented.

Abstract: The developing device according to the present invention includes a developing tank for containing two-component developer, a toner density sensor, and a toner cartridge. Further, the developing device according to the present invention includes a control section for inputting, to the toner density sensor, a control voltage (Vc) for correcting a sensor output. The control section sets the control voltage (Vc), by using a standard control voltage having been set so as to correspond to each of the stirring velocities, so that a sensor output (Vo) has a value within a range indicative of predetermined toner density. With the arrangement, it is possible to set the toner density sensor so that the toner density sensor operates in the most suitable manner so as to correspond to each of the stirring velocities, thereby realizing a developing device capable of detecting toner density with high accuracy.

Abstract: An image forming apparatus includes a toner image forming section including a developing device having a developer tank for storing a two-component developer, a transfer section, a fixing section, a recording medium feeding section, and a discharging section. The image forming apparatus further includes a toner concentration detecting section for detecting the toner concentration in the developer tank, a printing speed switching section, a toner concentration calculating section for correcting a detection result obtained by the toner concentration detecting section according to a speed of printing to calculate the toner concentration, and a toner replenishment control section for replenishing the toner into the developer tank according to a calculation result by the toner concentration calculating section.

Abstract: In an image forming apparatus comprising a charging section, an exposure section, a developing section, a transfer section, a peeling section, a cleaning section including a cleaning blade, and a fixing section, the cleaning blade is composed by dispersing 15 parts by weight through 33 parts by weight of fluorine resin particulate and secondary particles thereof into 100 parts by weight of a synthetic resin of a base material and, on a surface of the cleaning blade 16a, and a number of the secondary particles of the fluorine resin particulate having a particle diameter of 0.5 ?m or more existing in unit area of 100 ?m2 is made to be 50 or less.

Abstract: The developing device according to the present invention includes a developing tank for containing two-component developer, a toner density sensor, and a toner cartridge. Further, the developing device according to the present invention includes a control section for inputting, to the toner density sensor, a control voltage (Vc) for correcting a sensor output. The control section sets the control voltage (Vc), by using a standard control voltage having been set so as to correspond to each of the stirring velocities, so that a sensor output (Vo) has a value within a range indicative of predetermined toner density. With the arrangement, it is possible to set the toner density sensor so that the toner density sensor operates in the most suitable manner so as to correspond to each of the stirring velocities, thereby realizing a developing device capable of detecting toner density with high accuracy.

Abstract: An image forming apparatus of the present invention includes main control section for controlling the charging control section and the development bias control section so that a potential difference between the photoconductor potential and the development bias potential in developer discharge from the development section is smaller than that in the image forming. Therefore, even when an amount of developer in the development section decreases due to developer discharge, increase of beads-carry-over onto the photoconductor from the development section can be prevented. Accordingly, damage to the photoconductor or image errors due to incomplete cleaning that are caused by beads-carry-over can be prevented.

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: 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 cleaning device comprises: a first conveying member disposed further upstream in the rotating direction of a photoconductor drum than a cleaning blade, and constructed to rotate in non-contacting relationship to the photoconductor drum to convey residual toner that was removed by the cleaning blade; a second conveying member disposed parallel to the first conveying member and constructed to rotate in non-contacting relationship to the first conveying member; a first bias power supply for applying to the first conveying member a bias voltage having a polarity opposite to the proper polarity of the developer applied for development; and a second bias power supply for applying to the second conveying member a bias voltage having the same polarity as the proper polarity.

Abstract: In an image forming apparatus having a developing unit for developing an image using toner, a toner box for withholding the toner, and a toner transportation section for transporting the toner withheld in the toner box to the developing unit, the toner transportation section includes a transportation screw portion having formed a spiral blade section on its shaft, a pipe section for controlling a toner transportation route by covering the transportation screw portion of the toner transportation section, and a toner flow suppressing section for suppressing flow of the toner from a space between the transportation screw and pipe section. Consequently, a toner transportation opening formed near the transportation section can be closed, and therefore, the flowing of toner into the developing unit can be controlled or reduced by a simple and inexpensive arrangement.

Abstract: A photosensitive element is produced with a minimum amount of a conductive synthetic resin material. A draft for injection molding is formed in the inner circumferential surface as a supporting body, and a driven member provided with a gear is fixed to the end of the supporting body with a smaller inner diameter, that is, the thicker end. A driven portion in which a plurality of projections and depressions are formed alternately to be adjacent to each other in the circumferential direction is arranged on an axial end of a cylindrical supporting body made of a conductive synthetic resin, including a photosensitive layer on the outer circumferential surface. By a joint member removably engaged with the driven portion, the supporting body is rotated around the axis. In one arrangement, only the end of the supporting body is solid. In another arrangement, the supporting body is solid in the almost entire length in the axial direction.