Abstract: An image forming apparatus includes a plurality of photoreceptor drums, a plurality of developing devices, a plurality of polishing members, an endless intermediate transfer component, a primary transfer unit, a secondary transfer unit, a secondary transfer unit, a development refresh unit, and a photoreceptor refresh unit. The photoreceptor refresh unit is configured such that, in executing the photoreceptor-refresh control process, if the development refresh unit detects a toner-deteriorated developing device, the circumferential surface of the deteriorated photoreceptor drum is polished, by the polishing member provided for the deteriorated photoreceptor drum, using the polishing-agent contained in the toner discharged from the toner-deteriorated developing device by the development refresh unit executing the development-refresh control process.

Abstract: An image forming apparatus includes a plurality of photoreceptor drums, a plurality of developing devices, a plurality of polishing members, an endless intermediate transfer component, a primary transfer unit, a secondary transfer unit, a secondary transfer unit, a development refresh unit, and a photoreceptor refresh unit. The photoreceptor refresh unit is configured such that, in executing the photoreceptor-refresh control process, if the development refresh unit detects a toner-deteriorated developing device, the circumferential surface of the deteriorated photoreceptor drum is polished, by the polishing member provided for the deteriorated photoreceptor drum, using the polishing-agent contained in the toner discharged from the toner-deteriorated developing device by the development refresh unit executing the development-refresh control process.

Abstract: A plurality of separation needles are arranged downstream from a transfer roller in the sheet transport direction along a direction which is orthogonal to the sheet transport direction, and when a separation voltage is applied to the separation needles, an electrical discharge occurs between the photosensitive drum and the separation needles, and a sheet which has been charged by the transfer roller has static charge eliminated and is separated from the photosensitive drum. Furthermore, a transport unit established downstream from the separation needles in the sheet transport direction has a plurality of transport plates which guide the transport of the sheet, and a grounding plate which is located between these transport plates, and the grounding plate is connected to the grounding unit of the device body such that the grounding plate can be seen without interference from the tip end of the separation needles.

Abstract: Separation means 16, which are located downstream from a transfer roller in the sheet transport direction, apply a separation voltage to a plurality of separation needles 17 disposed in an alignment orthogonal to the direction of transport of the sheet, so as to produce a discharge between a photosensitive drum 2 and the separation needles 17 and remove the charge on the sheet that was charged by a transfer roller, so as to separate the sheet from the photosensitive drum 2, the separation means 16 comprising an upstream wall 27 and a downstream wall 28, and a ground electrode 33 being disposed on the back side of the downstream wall 28, which is the side not facing the separation needles 17, and protruding towards the photosensitive drum 2, beyond the line that connects the tips of the separation needles 17 and the end of the downstream wall 28.

Abstract: A separation device 16, which is located downstream from a transfer roller in the sheet transport direction, applies a separation voltage to a plurality of separation needles 17 disposed in an alignment orthogonal to the direction of transport of the sheet, so as to produce a discharge between a photosensitive drum 2 and the separation needles 17 and to remove the charge on the sheet that was charged by a transfer roller, so as to separate the sheet from the photosensitive drum 2, the separation device 16 having an upstream wall 27 and a downstream wall 28, and a ground electrode 33 being disposed on the back side of the downstream wall 28, which is the side not facing the separation needles 17, and protruding towards the photosensitive drum 2, beyond the line that connects the tips of the separation needles 17 and the end of the downstream wall 28.

Abstract: Separation means 16, which are located downstream from a transfer roller in the sheet transport direction, apply a separation voltage to a plurality of separation needles 17 disposed in an alignment orthogonal to the direction of transport of the sheet, so as to produce a discharge between a photosensitive drum 2 and the separation needles 17 and remove the charge on the sheet that was charged by a transfer roller, so as to separate the sheet from the photosensitive drum 2, the separation means 16 comprising an upstream wall 27 and a downstream wall 28, and a ground electrode 33 being disposed on the back side of the downstream wall 28, which is the side not facing the separation needles 17, and protruding towards the photosensitive drum 2, beyond the line that connects the tips of the separation needles 17 and the end of the downstream wall 28.

Abstract: A plurality of separation needles are arranged downstream from a transfer roller in the sheet transport direction along a direction which is orthogonal to the sheet transport direction, and when a separation voltage is applied to the separation needles, an electrical discharge occurs between the photosensitive drum and the separation needles, and a sheet which has been charged by the transfer roller has static charge eliminated and is separated from the photosensitive drum. Furthermore, a transport unit established downstream from the separation needles in the sheet transport direction has a plurality of transport plates which guide the transport of the sheet, and a grounding plate which is located between these transport plates, and the grounding plate is connected to the grounding unit of the device body such that the grounding plate can be seen without interference from the tip end of the separation needles.

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: 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: 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: The electrophotosensitive material in accordance with the present invention containing a layer which contains polycarbonate as a binding resin and of which glass transition temperature is not lower than 62.degree. C. This layer is excellent in adhesion to the foundation. This layer may be a photosensitive layer containing a m-phenylenediamine compound as a charge transferring material, or a photosensitive layer containing a m-phenylenediamine compound and a perylene compound as a charge generating material. The present invention also provides a photosensitive layer of which the amount of residual tetrahydrofuran is adjusted to a predetermined value or less, thereby to prevent the photosensitive layer from being decreased in sensitivity due to ultraviolet rays or visible ray.

Abstract: Disclosed is an organic laminated photosensitive material of the positive charging type comprising an electroconductive substrate, a charge-transporting layer formed on the substrate and a charge-generating and transporting layer formed on the charge-transporting layer. The charge-transporting layer is composed of a binder resin containing a hole-transporting substance, and the charge-generating and transporting layer is composed of a binder resin containing a charge-generating substance and a hole-transporting substance. In this laminated photosensitive material, an excellent sensitiveity is maintained even if the topmost charge-generating layer has a large thickness, and therefore, a high surface saturation charge voltage and an excellent printing resistance can be maintained in addition to an increased sensitivity.