Abstract: The present invention relates to image forming device such as copying machines and laser printers, which use an electrophotographic (xerognaphic) process. A simple control method without using any additional complex means can equalize a surface potentional of a light-sensitive drum to keep a light-quality of an image formed even for the first rotation of the light-sensitive drum. A charge-removal prohibiting means, a charge-potentional changing means and a developing bias-potentional changing means are controlled in accordance with an extent of a change of a surface potential of a light-sensitive body, which depends upon a light fatigue and an ambient temperature of the light-sensitive body and/or a pause after a preceding image process.

Abstract: An electrophotographic photoreceptor comprising a cylindrical electrically conductive substrate having thereon at least a photoconductive layer, the conductive substrate having a marking portion in which the light reflectance of the surface of the conductor substrate has been changed by a laser light treatment, a method for producing the photoreceptor, and an image correcting method using the photoreceptor.

Abstract: An electrophotographic photoreceptor comprising a cylindrical electrically conductive substrate having thereon at least a photoconductive layer, the conductive substrate having a marking portion in which the light reflectance of the surface of the conductor substrate has been changed by a laser light treatment, a method for producing the photoreceptor, and an image correcting method using the photoreceptor.

Abstract: A process control apparatus of electrophotographic apparatus has an optical sensor for optically detecting the density of toner patches formed on a photoreceptor drum. The present apparatus is further provided with a control device for controlling lamps for the copying process, chargers and other elements. A toner patch is formed on the photoreceptor so as to be located between every two toner images for a copying operation. The control device controls the lamps, chargers and other elements in accordance with the result of the toner patches detected by the optical sensor so as to stabilize the copying picture quality. With the arrangement, it is avoided that the job efficiency during the copying operation deteriorates, and the control data obtained from the toner patches is soon used for the toner image formation for the copying operation, thereby ensuring that the process control improves in accuracy.

Abstract: An apparatus includes a system controller which calculates a ratio of a first signal to a second signal and adjusts a control parameter of an electrophotographic reproduction process so that the density of fog indicated by the ratio is within a predetermined range. A first optical sensor outputs the first signal by detecting a reflectance of a non-image area on the photoreceptor between a developing unit and a transfer charger. A second optical sensor outputs the second signal by detecting a reflectance of a surface of the photoreceptor between a cleaning unit and a charger. The system controller controls developer including toner and carrier to be agitated when the ratio obtained after adjusting the control parameter is still outside the predetermined range. Since the density of fog is detected with accuracy by calculating the ratio, copy quality is stabilized even when temperature changes.

Abstract: The present invention provides a process control stabilizing system including a cleaning device for the corona wires which allows the process control to be carried out optimally based on exact information which is obtained by certain sensors while a discharge from the main charger unit is kept uniform. The system is constructed so that an electrode cleaner is activated before the detection of the surface potential and/or the detection of the optical density, and in addition, the cleaning operation will be operated until the detection result falls within a predetermined range. Alternatively, the system causes detection of the surface potential and/or detection of the optical both before and after a cleaning operation by the electrode cleaner. The cleaning operation will be repeated until the difference between the first and second detections falls within a predetermined range.

Abstract: A water-absorbing sheet assembly comprises two sheets, at least one of which is a water-permeable sheet, and a polymeric absorbent inserted between said two sheets, wherein at least a part of said two sheets are pressed and bonded to each other.

Abstract: A porous sheet is disclosed that comprises a thin, flexible sheet made of thermoplastic resin having solid particles distributed therein. Small spaces are formed around the particles, such that abrasion or buffing of the opposite surfaces of the sheet causes the formation of a multitude of fine pores that extend through the sheet, making the sheet vapor-permeable but liquid-impermeable.