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: 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 photoreceptor having a marking area whose optical reflection property differs from that of a non-marking area is formed in a portion of a surface of an electrically conductive substrate. The average line of a vertical section of the non-marking area cut across the border line with the marking area is M.sub.0 and the average line of a vertical section of the marking area cut across the border line is N.sub.0 and that straight lines touching the average lines M.sub.0 and N.sub.0 at the intersection of M.sub.0 and N.sub.0 are tangent lines M.sub.1 and N.sub.1, respectively, the acute angle .theta. between M.sub.1 and N.sub.1 is within the range of 0.degree..ltoreq..theta..ltoreq.30.degree.. Setting the angle .theta. within this range enables a photoconductive layer of a uniform characteristic to be laminated on the electrically conductive substrate even when the marking area is formed on the surface of the substrate.

Abstract: A box-shaped container (10) has an opening (12) and the opening is sealed tightly and doubly by a sealing material (13). The sealing material is hot-glued to a peripheral portion of the opening of the cartridge body to such an extent that the sealing material can be peeled from the peripheral part. The end portion (13a) of the sealing material is bonded at an adequate length from the free end to the face 11a of a side of the peripheral portion, and the free end portion is turned down for 180 degree angle to the outer side of the opening. Furthermore, the sealing material is bonded to the face (11b) of a opposite side of the peripheral portion side at which the free end portion (13a) is adhered and turned down to cover the opening in double covering. The sealing material also covers the turned-down end portion. The other end portion (13b) of the sealing material is attached to a roller (16), and as the user turns a handle (18) of the roller, the sealing material can be peeled off easily.

Abstract: Electrophotographic apparatus according to this invention are controlled in different ways such that quality of produced images is not affected by deterioration of the developing agent or the condition of the photoreceptor. A timer may be provided to detect the duration of a rest period to adjust the speed of development accordingly as well as by the number of copies produced. Similar control may be effected by measuring the surface voltage of the photoreceptor by a voltage detector and by adjusting the output level of the principal charger used for uniformly charging the photoreceptor prior to a development process.

Abstract: An image formation apparatus having a cleaning process for removing defective toner from the developing unit during a non-image formation rotation of the photoreceptor drum. The image formation apparatus includes a reverse polarity charger for charging the photoreceptor drum to an opposite polarity from the polarity that is used for forming an electrostatic latent image. The reverse polarity charger allows defective toner to be removed from the surface of the photoreceptor during a warming-up process of the apparatus or after a predetermined number of image forming processes have been performed.

Abstract: A long life cleaning blade for image forming apparatus is formed of a rubber elastomer which contains, or has adhered on the surface thereof, an antistatic agent in an amount effective to prevent electrification.

Abstract: A developing device for a copier is controlled such that if the rate at which toner is supplied into its developing tank is detected to exceed a preset reference value, stirring rollers for stirring the toner inside the developing tank are caused to rotate at a slower rate than if the toner supply rate is detected to be less than the reference value such that toner can be charged sufficiently in spite of its increased rate of supply and an image of good quality can be obtained.

Abstract: Before a photoreceptor for an electrophotographic image forming apparatus is uniformly charged at the beginning of a process for forming a latent electrostatic image thereon, the photoreceptor is exposed to charge-removing light for stabilizing the surface potential such that a high-quality image can be obtained. The level of exposure is modified in view of the fatigue and recovery characteristics of the photoreceptor. During a continuous operation of the photoreceptor, the level is logarithmically reduced. When the photoreceptor is started again after a rest period, the initial level of exposure is adjusted by logarithmically increasing it according to the length of the rest period as well as in view of the level of exposure prior to the rest period.

Abstract: An image transfer device has a screening plate attached to and protruding from a paper guide so as to partially block the corona ion current from its transfer charger such that only the forward portion of an incoming transfer paper sheet already in contact with the surface of a photosensitive drum is exposed to the current. An elastic guide plate separated from the drum surface by only about 1 mm serves to allow transfer paper sheet of different stiffness to come into contact with the drum surfaces at a predetermined position.

Abstract: A discharging apparatus for use in a copying machine for discharging the photoreceptor layer laminated on a drum includes a short wavelength light source for producing a light having a wavelength shorter than 6000 angstrom, and a long wavelength light source for producing a light having a wavelength longer than 6200 angstrom. A control circuit is provided for controlling both light sources such that both light sources are turned on during at least one complete rotation of the drum before an exposure of a light image on the photoreceptor layer.

Abstract: A copying machine with a multiple transport function having a separation charger for separating from the photoreceptor surface copy paper with an image transferred thereon and a circulating transport passage formed from the paper discharge block to the paper feed block so that it is possible to select the single-sided copy mode for allowing the copy paper to be discharged outside the copying machine after the copying process, the duplex copy mode for allowing the copy paper undergoing one copying process to be led through the circulating transport passage to the copying process block as reversed, or the composite copy mode for allowing the copy paper undergoing one copying process to be led through the circulating transport passage to the copying process block without being reversed.

Abstract: Disclosed is a useful method of removing a charge from an electrophotographic photoreceptor provided with insulation layers on its surface by radiating light containing a minimum of 6,000 angstroms of peak wave length onto said photoreceptor simultaneously with a corona discharge. To realize this, a filter is applied so that light containing a minimum of 6,000 angstroms of peak wave length can be generated.

Abstract: Image intensity adjustment in a copying machine is performed by simultaneously adjusting both a bias voltage to be applied to a developer unit of the copying machine and the intensity of light to be projected at an exposure section onto a photosensitive medium of the copying machine. Adjustment is facilitated by operatively connected variable resistors.

Abstract: An electrophotographic copying machine comprises a developing device for visualizing an electrostatic latent image as a toner image by delaying applying a developing bias voltage between a magnet roller and a photoreceptor to prevent carriers of a developer from being transferred onto the photoreceptor.

Abstract: An electrophotographic copying machine is of the type which starts, in response to the actuation of a copy start switch, its copying operation after a pre-copy process is conducted to stabilize the property of a photoreceptor. The copying machine comprises a selection circuit and a timer. The selection circuit is operated to start the timer upon the termination of a previous copying operation. During a time as set for the timer, the pre-copy process is carried out following the termination of the previous copying operation. In response to the actuation of the copy start switch, the following copying operation is started just following the termination of the previous copying operation.

Abstract: An electrophotographic apparatus employs an alternating current corona discharge apparatus for the purpose of forming an electrostatic image on a photosensitive member. The alternating current corona discharge apparatus has a transformer for transforming or stepping up the alternating current source voltage, the secondary winding of which is connected to the ground at one end. The secondary winding is shunted by a series connection of a first plurality of varistors. A smaller second plurality of series connected varistors selected from the first plurality of series connected varistors are shunted by a first diode-resistor series connection of a diode with the cathode on the ground side and a variable resistor and a smaller and third plurality of different series connected varistors selected from the first plurality of series connected varistors are shunted by a second diode-resistor series connection of a diode with the anode on the ground side and a variable resistor.

Abstract: An electrophotographic copying machine is disclosed comprising an image formation section for forming an electrostatic latent image on a photosensitive drum, and a magnet brush developing unit for developing the electrostatic latent image through the use of toner. A bias voltage is applied between the photosensitive drum and the magnet brush developing unit. A humidity sensor is disposed in the electrophotographic copying machine to develop an output signal indicative of the humidity in the electrophotographic copying machine. A bias voltage control circuit is associated with the humidity sensor for selectively determining the bias voltage at a higher value when the humidity exceeds a preselected threshold value. When the humidity is below the preselected threshold value, the bias voltage is held at a lower value.