Abstract: The cell wall removal ratio of an elastic foam body is set such that developer or other fouling material adhering to a rotatable member can be continuously absorbed through the cells of the elastic foam body during a single maintenance cycle of an image forming apparatus. For example, the cell wall removal ratio of the elastic foam body is set to at least 60% or at least 80%. When the cell wall removal ratio of the elastic foam body is set to at least 60%, good image quality can be maintained reliably until the number of sheets recorded by the image forming apparatus reaches 20000. Furthermore, when the cell wall removal ratio of the elastic foam body is set to at least 80%, good image quality can be maintained reliably until the number of sheets recorded by the image forming apparatus reaches 30000.

Abstract: A cleaning apparatus for a rotatable brush that contacts upon or slides along a carrier of electrostatic latent images in order to apply an electric potential to the carrier of the electrostatic latent images, includes, an elastic foam body pressed by the bristles of the rotating brush provided downstream in a direction of a rotation of the rotating brush from a position of contact with the carrier of the electrostatic latent images, and a slide member pressed by the bristles of the rotating brush downstream in the direction of the rotation of the rotating brush from the elastic foam body, wherein the elastic foam body has a contact face that presses the rotatable brush, a discharge face that discharges developer or the like that enters the elastic foam body, and all faces other than the contact face and the discharge face are sealed.

Abstract: The cell wall removal ratio of an elastic foam body is set such that developer or other fouling material adhering to a rotatable member can be continuously absorbed through the cells of the elastic foam body during a single maintenance cycle of an image forming apparatus. For example, the cell wall removal ratio of the elastic foam body is set to at least 60% or at least 80%. When the cell wall removal ratio of the elastic foam body is set to at least 60%, good image quality can be maintained reliably until the number of sheets recorded by the image forming apparatus reaches 20000. Furthermore, when the cell wall removal ratio of the elastic foam body is set to at least 80%, good image quality can be maintained reliably until the number of sheets recorded by the image forming apparatus reaches 30000.

Abstract: The periphery of a metal rotating shaft is covered with elastic foam material and the peripheral surface of the elastic foam material is coated with conductive adhesive. Before the layer of conductive adhesive hardens, a plurality of bristles is embedded vertically into the smooth material made of a layer of conductive adhesive, thus forming a bristle-embedded layer upon the periphery of the smooth material. Thereafter, the conductive adhesive to become the smooth material is hardened. Alternately, a metal shaft with an outside diameter slightly smaller than the inside diameter of the tube is inserted into the interior of the conductive tube, the tube is heated to cause heat shrinkage, thus tightly adhering the tube to the metal shaft, so that the metal shaft maintains the cylindrical shape of the tube. After the tube is coated with conductive adhesive, it is spirally wrapped with conductive brush cloth cut into strips.

Abstract: It is an object of the invention to inspect defects of a film formed on a relatively rough surface of a substrate by the light interference method. A substrate on which a film is formed is irradiated with light of a longer wavelength than the surface roughness Rmax or Rz of the substrate to obtain interference fringes to inspect defects of the film formed on the substrate. Especially, it is preferable that when the surface roughness Rmax or Rz is 0.5 &mgr;m or more, the substrate is irradiated with light of a wavelength beyond a little longer wavelength than the surface roughness Rmax or Rz. The surface of the substrate is subjected to a cutting process. Specifically, it is possible to inspect defects of the electric charge generation layer, electric charge transport layer, or undercoat layer of an electrophotographic photoreceptor. This photoreceptor is mounted in a digital copier or printer. Further, monochromatic light is preferably applied.

Abstract: It is an object of the invention to inspect defects of a film formed on a relatively rough surface of a substrate by the light interference method. A substrate on which a film is formed is irradiated with light of a longer wavelength than the surface roughness Rmax or Rz of the substrate to obtain interference fringes to inspect defects of the film formed on the substrate. Especially, it is preferable that when the surface roughness Rmax or Rz is 0.5 &mgr;m or more, the substrate is irradiated with light of a wavelength beyond a little longer wavelength than the surface roughness Rmax or Rz. The surface of the substrate is subjected to a cutting process. Specifically, it is possible to inspect defects of the electric charge generation layer, electric charge transport layer, or undercoat layer of an electrophotographic photoreceptor. This photoreceptor is mounted in a digital copier or printer. Further, monochromatic light is preferably applied.