Abstract: An image forming apparatus has a charge roller, a charge erasing device and a preliminary voltage-applying member disposed around a rotationally movable photosensitive member. The charge roller subjects a surface of the photosensitive member to a charge process while contacting the surface of the photosensitive member. The charge erasing device is on an upstream side of the photosensitive member relative to the charge roller and erases the charged area in the photosensitive member. The preliminary voltage-applying member is on an upstream side of photosensitive member relative to the charge erasing device and applies to the surface of the photosensitive member a voltage of the same polarity as the voltage applied from the charge roller to the surface, while contacting the surface. The preliminary voltage-applying member is reciprocated along the surface of the photosensitive member and in a direction orthogonal to the movement direction of the surface.

Abstract: An image forming apparatus has a charge roller, a charge erasing device and a preliminary voltage-applying member disposed around a rotationally movable photosensitive member. The charge roller subjects a surface of the photosensitive member to a charge process while contacting the surface of the photosensitive member. The charge erasing device is on an upstream side of the photosensitive member relative to the charge roller and erases the charged area in the photosensitive member. The preliminary voltage-applying member is on an upstream side of photosensitive member relative to the charge erasing device and applies to the surface of the photosensitive member a voltage of the same polarity as the voltage applied from the charge roller to the surface, while contacting the surface. The preliminary voltage-applying member is reciprocated along the surface of the photosensitive member and in a direction orthogonal to the movement direction of the surface.

Abstract: A driving mechanism for use in an image forming apparatus has a rotary shaft, a driving joint, a drum gear, a cleaning roller gear, and a transfer roller gear. The rotary shaft extends through a photosensitive member along an axis of rotation of the photosensitive member. The rotary shaft is rotatably supported at the opposite axial end parts thereof by bearings, respectively. The rotary shaft is un-rotatably jointed to the photosensitive member relative thereto at a lateral side part of a rear end part of the rotary shaft corresponding to the rear side of the image forming apparatus. The driving joint is jointed to the rear end part of the rotary shaft protruding from the photosensitive member at the rear side of the image forming apparatus to input a rotating force of a drum motor to the photosensitive drum. The drum gear is provided at the rear side of the photosensitive member. The cleaning roller gear and the transfer roller gear are in mesh with the drum gear.

Abstract: A driving mechanism for use in an image forming apparatus has a rotary shaft, a driving joint, a drum gear, a cleaning roller gear, and a transfer roller gear. The rotary shaft extends through a photosensitive member along an axis of rotation of the photosensitive member. The rotary shaft is rotatably supported at the opposite axial end parts thereof by bearings, respectively. The rotary shaft is un-rotatably jointed to the photosensitive member relative thereto at a lateral side part of a rear end part of the rotary shaft corresponding to the rear side of the image forming apparatus. The driving joint is jointed to the rear end part of the rotary shaft protruding from the photosensitive member at the rear side of the image forming apparatus to input a rotating force of a drum motor to the photosensitive drum. The drum gear is provided at the rear side of the photosensitive member. The cleaning roller gear and the transfer roller gear are in mesh with the drum gear.

Abstract: An image-forming apparatus for forming an image by electrically charging a photosensitive material, forming an electrostatic image through the exposure to light and developing the electrostatic image, wherein the main charged potential, Vo, of the photosensitive material, the potential, Vr, of the exposed portion of the photosensitive material and the developing bias potential DB are so set as to satisfy the following formulas, V1≦|DB−Vr|≦V2  (1) V3≦|Vo−DB|≦300  (2). V1, V2 and V3 are parameters calculated from a developing characteristics curve obtained by plotting the image densities to a potential difference between the developing bias potential and the surface potential, 0 V, of the photosensitive material when the image is formed by changing the developing bias potential with the exposure amount being zero in a state where the potential on the surface of the photosensitive material is maintained at zero.

Abstract: An image-forming apparatus for forming an image by electrically charging a photosensitive material, forming an electrostatic image through the exposure to light and developing the electrostatic image, wherein the main charged potential (Vo) of the photosensitive material, the potential (Vr) of the exposed portion of the photosensitive material and the developing bias potential DB are so set as to satisfy the following formulas (1) and (2),

Abstract: A developing roller and a developing device are provided to enable a satisfactory developing operation. In order to accomplish this object, a roller main body of the developing roller is made of a roller base material containing acrylonitrile-butadiene rubber as a main component, and an adherence preventing coating layer is formed on the outer circumferential surface of the roller main body, thereby preventing the adherence of developer to the roller main body. Particularly, by setting the friction coefficient of the coating layer within a range of 0.5 to 0.95 inclusive and/or the glossiness thereof within a range of 4.5 to 8 inclusive, an occurrence of any of negative ghost, positive ghost and background fogging is prevented or suppressed to a level where no problem is presented in practical use.

Abstract: The developing process of this invention comprises supplying a charged toner to a development roller disposed against a photosensitive drum, forming a thin layer of the charged toner on the development roller by a blade press-contacted with the development roller, and contacting this thin layer of the charged toner on the surface of the photosensitive drum on which an electrostatic latent image is formed. The process further comprises using a non-magnetic toner which has a circularity degree of more than 0.94 and which has a falling amount of at least 10 g/5 minutes as measured by a tester for measuring the amount of falling. By using such a toner, it is possible to prevent the collection of the toner on the bottom of a development housing which includes various members for practicing the above process, and it is also possible to prevent the rising of a driving torque of the rollers.

Abstract: The photosensitive material of the present invention is provided in contact with a developing roller and has a surface potential decay characteristic in which when the photosensitive material is charged to a surface potential of 800 V and is contacted with the developing roller to which a voltage (VR) is applied, the surface potential (VD) of the photosensitive material after contacting is represented by the formula (1):VD.gtoreq.800.times.EXP (0.00235.times.VR).By using this photosensitive material, a transverse black stripe in the tip of the transfer paper is prevented and it is possible to form an image having excellent image quality and image density.

Abstract: An image-forming machine includes a photosensitive drum rotatably disposed; a charger for electrically charging the peripheral surface of the photosensitive drum to a predetermined polarity; a developer for developing an electrostatic latent image formed on the peripheral surface of the photosensitive drum into a toner image; a transfer device for transferring the toner image formed on the peripheral surface of the photosensitive drum onto a transfer paper; a fixing roller for heat-fixing the toner image transferred onto the transfer paper by the transfer device; and a cooling fan for blowing cooling air to the surrounding area of the fixing roller. A guide plate having a plurality of openings formed along its length, guides the transfer paper onto which the toner image has been transferred by the transfer device, to the fixing roller.

Abstract: The present invention provides a novel naphthylenediamine derivative which is superior in electric charge transferring capability, compatibility with binding resin and stability, and an electrophotosensitive material which has a higher sensitivity and an excellent durability. The above naphthylenediamine derivative is represented by the following general formula (1), and the electrophotosensitive material is formed by providing a photosensitive layer having this naphthylenediamine derivative as an electric charge transferring material on a conductive substrate. ##STR1## wherein R.sup.1 to R.sup.4, R.sup.5a to R.sup.5f and a to d are as defined.

Abstract: An electrophotographic method in which an electrostatic latent image on a single-layer organic photosensitive material is developed while applying a developing bias voltage of the same polarity as the polarity of the charge of the photosensitive material. The developing bias voltage is set to be higher than a potential that corresponds to a point where a curve approximating the zone of a large amount of exposure to light and a curve approximating the zone of a small amount of exposure to light in a light decay characteristics curve intersect each other.

Abstract: A process unit comprising a photoconductor unit and a developing unit supported pivotably via a support shaft. The photoconductor unit and the developing unit each have a pair of support side walls having support holes formed on the same axis. One pair of the support side walls define a pair of inner support side walls having an outside width smaller than the inside width of the other pair of the support side walls, while the other pair of the support side walls define a pair of outer support side walls. The pair of outer support side walls and the pair of inner support side walls are supported via the support shaft passing through the respective support holes. One end of the support shaft is supported by one of the outer support side walls via a bearing member detachably mounted in the support hole of the one of the outer support side walls.

Abstract: An image forming apparatus includes a rotatable photosensitive member including a conductive base and a photosensitive layer located on a surface of the base; a charging device located in the vicinity of the photosensitive member for charging the photosensitive layer; a charge removing device located upstream with respect to the charging device in a rotation direction of the photosensitive member for radiating light toward the photosensitive layer prior to charging performed by the charging device to uniformize a surface potential of the photosensitive layer; a light radiation device for radiating light to a charging area of the photosensitive layer in the state of being charged by the charging device and for adjusting the amount of the light to be radiated; an exposing device for radiating light corresponding to an image toward the photosensitive layer in the state of being charged; a developing device located downstream with respect to the exposing device in the rotation direction of the photosensitive memb

Abstract: An image forming apparatus includes a rotatable photosensitive member including a conductive base and an organic photosensitive film located on a surface of the base and containing two charge generation materials which have different light absorbing characteristics from each other and different wavelengths showing a maximum light absorbance from each other; a charging device for charging the organic photosensitive film, the charging device being located in the vicinity of the photosensitive member; a charge removing member including a light source for radiating light toward the organic photosensitive film to uniformize the potential of a surface of the organic photosensitive film, the light having a wavelength in the range between wavelengths corresponding to half of a maximum light absorption of at least one of the two charge generation materials; an exposing device for radiating light corresponding to an image toward the organic photosensitive film charged by the charging device; and a developing device loc

Abstract: A compact electrophotographic apparatus is attained by decreasing the diameter of the photosensitive drum so that a plurality of rotations of the drum are required to produce a single sheet image. Images of excellent quality, especially with respect to the lack of stepwise density decrease across the image due to multiple drum rotations per image, are achieved by providing for discharge of the photosensitive drum so that the residual potential on the drum is 10% or less of the charged surface potential after discharge on the first rotation of the drum and the increase in the residual potential is not more than 30% after discharge on the last rotation of a sheet making cycle.

Abstract: An image forming apparatus includes a charge removing device for removing the residual charge on a photosensitive film. The light emitted from an optical source of the charge removing device is selected from the range between the wavelengths which correspond to half of the maximum absorbance in a light absorbance characteristic of the photosensitive film. Since carrier generation does not occur by the light emitted by the charge removing device, the charging ability and the charge retaining ability of the photosensitive film are improved, and the image quality is significantly improved.

Abstract: An electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer comprising a thermosetting silicone resin, and a methyl-butyl etherified melamine-formaldehyde resin in an amount of from 0.1 to 30 parts by weight per 100 parts by weight of the non-volatile solid components of the thermosetting silicone resin, an electrophotographic photosensitive element comprising a photosensitive layer and a surface protective layer on the photosensitive layer, the surface protective layer comprising a thermosetting silicone resin, and an acrylic copolymer having an average molecular weight of 6,000 or less in an amount of from 0.

Abstract: Image processing equipment featuring that image forming processing is conducted by selectively applying image density setting conditions according to the temperature of a photo-sensitive body when characteristic deterioration exceeding an appointed level is detected by detecting irreversible characteristic deterioration of the photosensitive body.

Abstract: The invention presents an electrophotographic photosensitive material possessing a surface layer excellent in wear resistance, without adversely affecting the photosensitive characteristics, wherein a photosensitive layer and a surface protective layer containing a thermoset silicone resin are laminated in this order on a substrate surface, and the silicone resin of the surface protective layer is hardened by a hardening catalyst mainly composed of a compound of the general formula (I) or an acid salt thereof which is selected from the group consisting of: a phenol salt, an octylic acid salt, a p-toluenesulfonic acid salt and a formic acid salt ##STR1##