Abstract: A fence electrifying device supplied with AC power with a triggering circuit 23 having an input 27 connected to the common point of the resistor 4 and diodes 3 and 6, and an input 25 connected to the input terminal 1. The triggering of the conductive state in the thyristor takes place when the first terminal 1 is in the vicinity of its most negative potential in relation to the potential of the second terminal 2.

Abstract: This invention pertains to a sawtooth AC charger (10) in which an AC voltage signal applied to sawtooth blades (12) has a duty cycle greater than 50%. Duty cycles above about 70% increase the uniformity of negative charging without significantly increasing the peak voltage to the sawtooth blades.

Abstract: The invention provides a charging member for electrically charging an object by placing the member in contact with the object and applying voltage between them. The member includes a shaft and an elastic layer and a conductive layer successively formed around the shaft, and has a capacitance of up to 1.times.10.sup.-9 F. and preferably a surface roughness of up to 20 .mu.m on JIS ten point mean roughness scale. The charging member is effective for suppressing charging noise.

Abstract: Electrostatic spray coating system which accurately determines the actual value of a high voltage present on at least one high voltage electrode as coating material is electrostatically charge. A control or input voltage is measured on the input of a voltage transformer and multiplier circuit and is multiplied by the voltage multiplication factor of the voltage transformer and multiplier circuit, thereby calculating the theoretical or no load value of the voltage on the high voltage electrode. This theoretical value deviates from the actual value of the electrode voltage by the amount of the internal voltage drop across the voltage transformer and multiplier circuit when a current flows in it. The internal voltage drop is determined as a function of the electrode current and is subtracted from the theoretical value in order to generate a signal voltage corresponding to the actual value of the electrode high voltage.

Abstract: An image forming apparatus includes an image bearing device, a charger contactable to the image bearing device for effecting contact charging of the image bearing device, the charger being supplied with a voltage having a DC component and an AC component, and the charger being provided with an electrode for receiving the voltage; wherein the following is satisfied: when an electric field formed between the image bearing device and the electrode is not more than .vertline.E/d.sub.SD .vertline. (V/m), a resistance of the charger per unit area of contact between the image bearing device and the charger is larger than20E/(wCV.sub.DC) (.OMEGA.m.sup.2)and is larger than the resistance when the electric field is more than .vertline.(E+V.sub.DC)/d.sub.SD .vertline. (V/m)where E(V) is an amplitude of the AC component; w(rad) is an angular velocity of the AC component; d.sub.SD (m) is a minimum distance between the electrode and the image bearing device; C(F/m.sup.

Abstract: A charging apparatus or an electrophotographic apparatus includes an electrophotographic photosensitive member including a photosensitive layer provided on a conductive supporting member, and a charging member including magnetic particles, disposed to be in contact with the electrophotographic photosensitive member, for charging the electrophotographic photosensitive member when a voltage is applied to the charging member. The layer of the electrophotographic photosensitive member most separated from the conductive supporting member has a volume resistivity between 10.sup.8 .OMEGA..cm and 10.sup.15 .OMEGA..cm, and the magnetic particles have a hygroscopic property such that the ratio H/L of the maximum value H to the minimum value L of the amount of water contained within the particles is at least 1 and less than 4.

Abstract: The relationship between a discharge gap and a surface potential, and a relationship between a discharge gap and a surface potential variation are obtained. Then, a range of a discharge gap is obtained (approximately 5.about.10 mm) satisfying a range of the required surface potential (-600 V) and the tolerable surface potential variation (30 V). The relationship of the discharge gap with respect to the surface potential and the surface potential variation is varied by reducing the applied current. The discharge gap is converged to one value (approximately 7.5 mm) in response to the range of the discharge gap being reduced.

Abstract: An image forming apparatus having a device for moving a charging roller towards and away from a photoreceptor and a cleaning member for the charging roller. The charging roller moving device moves the charging roller to positions including a first position where the charging roller is in contact with the photoreceptor and is separated from the cleaning member for a charging operation, a second position where the charging roller is in contact with the cleaning member for cleaning the surface of the charging roller and a third position where the charging roller is separated from the photoreceptor and the cleaning member. Even if the apparatus is left unoperated for a long time, the photoreceptor is prevented from being contaminated by the charging roller by placing the charging roller in the third position.

Abstract: An method and apparatus for eliminating residual charge potential in a multicolor electrostatographic system is disclosed, wherein a transparent conductive solution is applied to a developed image for neutralizing any charge potential therein prior to subsequent development of a superimposed electrostatic latent image. An apparatus for applying a thin layer of charge neutralizing material to the developed image is provided. In addition, various solutions have been described which may be advantageously utilized to provide a charge neutralizing material in the context of the present invention.

Abstract: A contact charging system uniformly charges a photoconductive surface by the use of a resistive belt surrounding and moved by two rollers and in contact with the photoconductive surface. The roller at the pre-nip area is grounded while that at the post-nip area is kept at a desired high potential. Alternatively, a pair of shoes are used for contact charging a photoconductive surface with one of the shoes being grounded and the other being biased to a desired DC potential by a biasing source. A resistive film is in contact with the pair of shoes with both the film and shoes being in contact with the photoconductive surface. Also, a blade is used to uniformly charge a photoconductive surface with one portion of the blade being grounded and another portion being biased to a desired DC potential. The blade is in direct contact with the photoconductive surface. This charging system tailors the electric field so that air breakdown only occurs at the post-nip area.

Abstract: Since the first cleaning member 24g scrapes off the foreign materials adhered to the corona charging electrode, and following that, the second cleaning member 24h wipes off the scraped foreign materials, the layered foreign materials firmly adhered on the corona charging electrode 22 is removed. Accordingly, image formation in electrophotographic apparatus or the like is suitably carried out, and image quality deterioration of the recorded image is suppressed.

Abstract: A web or film is electrostatically charged by sequentially subjecting the web or film to a series of electric fields such that adjacent electric fields have substantially opposite polarities. Both a method and apparatus are disclosed for charging the web or film.

Abstract: In a conductive plate of an upper electrode of an electric gathering apparatus for manufacturing a poppet valve used in an internal combustion engine, there is formed a polygonal bore in which a drive shaft is engaged. An annular cut-away portion which is larger than the engagement bore in diameter is formed, thereby preventing a burr and increasing durability of the electrode.

Abstract: The present invention comprises a photosensitive member supported for rotation within a unit case and a charger for uniformly charging the photosensitive member. The charger includes a conductive member in the form of a sheet held in contact with the photosensitive member and a supporting member having a non-flat cross section for supporting the conductive member, in which the charger applies a voltage formed of a direct-current voltage with an alternating-current voltage added thereto to the conductive member to thereby uniformly charge the photosensitive member. The charger is kept in place by having the supporting member fixed to vertical planes of the unit case at positions off vertical planes crossing the photosensitive member.

Abstract: Pyroelectric materials are used to create net charge/surface potentials for use in xerographic charge and transfer steps. Heating and cooling a pyroelectric film, such as, polyvinylidene fluoride induces thermal expansion or contraction which create surface charge density changes that can be used to charge a photoconductive surface and/or transfer an image from a photoconductive surface to a copy sheet.

Abstract: A charging apparatus includes a charging surface for charging a member to be charged, wherein a voltage is applied between the charging apparatus and the member to be charged; and projections for contacting the charging apparatus substantially at three positions to the member to be charged to closely face a charging surface to the member to be charged.

Abstract: An image forming apparatus includes a charging member to be contacted with a rotating photosensitive body so as to charge the photosensitive body, a temperature detection device for detecting temperature of the charging member, and a voltage control device for controlling a voltage to be supplied to the charging member in accordance with a temperature value detected by the temperature detection device.

Abstract: A charging member for electrophotography comprising a surface layer, wherein the surface layer comprises a resin and an alkali metal salt contained therein.

Abstract: A charging member for charging a member to be charged, includes a magnet member and a surface electroconductive layer for supporting electroconductive magnetic particles, the layer being supported by the magnet member and rotating together with the magnet member in a region supporting the magnetic particles.

Abstract: An image forming apparatus includes a image bearing member having a photosensitive layer, a surface protection layer having fluorine resin material; a charging member contactable to the image bearing member to electrically charge the image bearing member, the charging member is capable of being supplied with an oscillation voltage, and wherein a peak-to-peak voltage of the oscillating voltage applied across a gap between a surface of the charging member and the surface of the image bearing member, is not less than twice a charge starting voltage of the image bearing member in the gap and not more than 1600 volt.

Abstract: A corona-discharging type charging device for charging a photoreceptor includes saw tooth-shaped electrodes facing the photoreceptor; side plates applied with a DC bias voltage Vs and provided on both sides of the saw tooth-shaped electrodes; and a control grid applied with a DC bias voltage Vg and provided between the saw tooth-shaped electrodes and the photoreceptor.

Abstract: The image forming method comprises, electrostatically charging an image bearing member using a contact charging assembly, forming an electrostatic latent image on the image bearing member thus charged, developing the electrostatic latent image with a magnetic toner to form a toner image and transferring the toner image to a transfer medium, wherein the charging assembly comprises a magnetic brush formed from conductive magnetic particles magnetically bound, and the charging assembly comes into contact with the image bearing member to charge the surface of the image bearing member by directly injecting charges into the electron level present on the surface of the image bearing member and the magnetic toner has a value of .sigma..D..delta. of 150 or less, where the value is obtained by multiplying i) a magnetization quantity .sigma. (Am.sup.2 /kg) in a magnetic field of 1K oersted as measured by a vibration magnetometer, ii) a weight average particle diameter (D.sub.4) D (.mu.

Abstract: A method of electrically charging a material to be charged by bringing a charging member impressed with a voltage into physical contact with the material to be charged, wherein the charging member is constituted by a flexible and electrically conducting endless sheet and a rotary insulating brush which supports the endless sheet at a position where the endless sheet and the material to be charged are in contact with each other and gives a pushing force to the endless sheet, and the endless sheet is driven actively or passively together with the insulating brush at a speed substantially in synchronism with the material to be charged while applying a charging voltage to the endless sheet. This method makes it possible to uniformly and stably charge the surface of the photosensitive material even when defects such as pinholes or the like exist in the surface of the photosensitive material, without causing the life of the photosensitive material to be shortened.

Abstract: A charging device includes a substantially cylindrical charging electrode formed by rolling a flexible, semiconductive film, an electrode support member inserted in the substantially cylindrical charging electrode to support the charging electrode so as to be in contact with the turning surface of a charge acceptor, and a voltage applying means for applying a charging voltage to the charging electrode. The electrode support member is held with a gap between the electrode support member and the charge acceptor so that the charging electrode can be turned by an electrostatic force acting between the charging electrode and the charge acceptor. When a charging voltage is applied to the charging electrode, the charging electrode is pulled toward the charge acceptor by an electrostatic force acting between the charging electrode and the charge acceptor.

Abstract: An image forming apparatus includes an opening portion that opens toward a photosensitive body and has a stagnant portion in which discharge products produced by a discharging means stagnate. A partition member is disposed in the vicinity of an opening of the opening portion, the opening opposing a photosensitive body, the partition member preventing discharge products that fall from the stagnant portion from falling directly into contact with the photosensitive body.

Abstract: The present invention releases anion out of a main body of an end product, driven by convection caused by heat from heating parts inside the main body. According to this apparatus, anions are released out of the main body by circulating convective air flow caused by heat from heating parts at the lowest part inside the main body. Thus an extra fan and the related circuits are unnecessary.

Abstract: A charging device includes a member to be charged; a charging member for charging the member to be charged, the charging member being contactable to the member to be charged and being supplied with a voltage; and wherein upon switching of the voltage from a DC component mode to a superimposing component mode of a DC component and an oscillation component, the DC component is decreased, and a peak-to-peak voltage of the oscillation component is increased in a period, and wherein the peak-to-peak voltage is changed from a first voltage which is smaller than twice a charge starting voltage of the member to be charged to a second voltage which is twice the charge starting voltage, while the peak-to-peak voltage is increasing.

Abstract: At least a photosensitive drum 2 and charge roller 9 are attached to a unit 8 so that the photosensitive drum 2 and charge roller 9 can be freely attached to and detached from an apparatus body 1 in unison with the unit case 8, and the charge roller 9 can be freely brought into and out of contact with the surface of the photosensitive drum 2. The apparatus body 1 is provided with pressure cams 5a and 5b adapted to cause the charge roller 9 to be brought into and out of contact with the surface of the photosensitive drum 2.

Abstract: An electrostatic support system for applying posters and the like in a removable fashion on wall surfaces using a thin film or foam layer of dielectric backing and a hand-held high voltage charger suitable for creating corona charged particles. The system and method provide a practical, simple and inexpensive manner of mounting displays which may be easily removed and repositioned without damage to the wall surface.

Abstract: A brush contact charger charges a photosensitive drum of an image forming apparatus adopting an electrostatic recording system, and has a body having a brush for contacting a photosensitive drum and then charging the photosensitive drum, a reciprocating portion for reciprocating the body perpendicularly with respect to the proceeding direction of the photosensitive drum, and a guide member for supporting the body while guiding the reciprocal movement of the body. The charger charges the surface of the photosensitive drum while moving at a right angle with respect to the proceeding direction of the photosensitive drum and charges the surface of the photosensitive drum to an electrical potential having a nearly uniform distribution.

Abstract: In the roller charging apparatus according to the present invention, the charging roller includes a layer of an epichlorohydrin rubber, so that it is possible to eliminate electric nonuniformity of a conductive elastic layer and to be charged by loading only a DC voltage. The charging roller also may have a surface layer formed of polyamide resin or fluorine resin. In addition durability can be improved by setting the roller hardness of the charging roller to 42 (measured by a JISA hardness meter) or more. Further, a roller diameter D.sub.r of the charging roller and drum diameter D.sub.d of the photosensitive drum may satisfy the relation of D.sub.d /D.sub.r .gtoreq.4. A cleaner can also be provided for removing foreign materials, such as toner, from the charging roller, and the cleaner may have a rubber hardness less than that of the charging roller.

Abstract: Printing machines and systems which incorporate recharging stations comprised of two corona generating devices which act together to recharge a previously developed photoreceptor to a predetermined potential. The first corona generating device recharges the photoreceptor's surface to a greater absolute potential than a predetermined potential which the surface is to have after being recharged. The second corona generating device reduces the photoreceptor's surface to the potential that it is to have. The second corona generating device is comprised of a plurality of spaced apart coronodes which each can impress charges on the photoreceptor's surface. The second corona generating device receives electrical inputs and applies DC potentials to the coronodes such that adjacent coronodes have opposite polarities.

Abstract: An image forming apparatus includes a contact charging member which contacts a surface of an image carrier member in order to charge the surface of the image carrier member, and a cleaning member which contacts and slides on a surface of the contact charging member in order to clean the surface of the contact charging member. The image forming apparatus performs a function in such a way that after an electrostatic latent image is produced on the image carrier member which is in a charged state, toner powder is supplied to the image carrier member by a developing device in order to make the electrostatic latent image visible and then a visualized image is transferred to a transfer member. In the image forming apparatus, a maximum height of concavities and convexities formed on the surface of the contact charging member is equal to or less than an average particle diameter of the toner powder supplied by the developing device.

Abstract: An apparatus and method for depositing a surface charge on a dielectric medium moving at a predetermine velocity in a direction of movement, including an endless web having an exterior layer comprising piezoelectric material, position adjacent to the dielectric medium, for generating and laying down the surface charge on the dielectric medium in response to the endless web being deformed.

Abstract: A contact charging member is used in a charging device for charging an image carrier by contacting the contact charging member to which a voltage is impressed with the image carrier. The contact charging member has at least a supporting member and a coating member. The coating member is a seamless tube consisting of a resin blend of a flexible resin and a heat resistant resin.

Abstract: An object, typically photoconductor drum is electrically charged by placing a contact charger member in abutment with the object to be charged and applying voltage between the contact charger member and the object. Charging is effected by properly controlling the capacitance of the contact charger member, the capacitance of the object, and the applied voltage. A sufficient charged potential is achieved through the application of a relatively low voltage, while preventing ozone generation.

Abstract: An apparatus for applying an electrical charge to a charge retentive surface by transporting ions through an ionically conductive liquid and transferring the ions to the member to be charged across the liquid/charge retentive surface interface. The ionically conductive liquid is contacted with the charge retentive surface for depositing ions onto the charge retentive surface via a wetted donor blade supported within a conductive housing, wherein the housing is coupled to an electrical power supply for applying an electrical potential to the ionically conductive liquid. In one specific embodiment, the charging apparatus includes a support blade for urging the donor blade into contact with the charge retentive surface and a wiping blade for wiping any liquid from the surface of the charge retentive surface as may have been transferred to the surface at the donor blade/charge retentive surface interface.

Abstract: A conductive ceramic composition is disclosed which consists essentially of alumina, chromia, and magnesia, and is suitable for use as target electrodes in electrostatic fiber charging applications. Ceramics are disclosed which have exhibit volume resistivities of 10.sup.12 ohm-cm or less at 20.degree. C., and have excellent electrical stability and superior mechanical properties; and an electrostatic charging apparatus is disclosed which employs a ceramic electronic conductor having a volume resistivity of from about 1.times.10.sup.7 to 5.times.10.sup.10 ohm-cm and a hardness of at least 5 GPa.

Abstract: There is provided by the present invention an electrifying roller having a roller layer having at least two layers of an elastic layer provided on a peripheral surface of core metal and a surface layer covering the elastic layer, wherein a slope (.DELTA.I/.DELTA.V) of the V-I characteristics of the roller layer is 1 or less, the electrifying roller is rotated in contact with the light-sensing drum, a voltage is loaded from a power supply unit to the core metal of the electrifying roller, and a surface of the light-sensing drum is electrified to a surface potential (Vs).

Abstract: A charging roller for use in a xerographic copying machine includes a cylindrical roller core, and a ceramic layer formed by plasma spraying a blend of an insulating ceramic material and a semiconductive ceramic material in a ratio which is selected to control an RC circuit time constant of the ceramic layer in response to an applied voltage differential. The ceramic layer is sealed with a solid, low viscosity sealer, such as Carnauba wax, to protect the ceramic layer from moisture penetration.

Abstract: A particle charging apparatus for charging a photo-sensitive drum by magnetically holding magnetic particles in a charging zone and impressing a charging bias on the magnetic particles. Adjacent to an opposed pole which is disposed on the back side of the photo-sensitive drum on the charging zone upstream side for forming a vertical magnetic field, an opposite polarity magnet or magnetic member is disposed such that a mainly horizontal magnetic field is formed on the drum by the opposed and adjacent poles. A vertical magnetic field is formed on the charging zone downstream side by a main pole and the opposed pole. A non-magnetic sleeve with the main pole therein is rotated in the direction opposite that of the drum, thus causing magnetic particles in the vertical magnetic field to be circulated toward the charging zone upstream side.

Abstract: An image forming apparatus includes image bearing member or members for bearing an image; charging member for sequentially charging a surface of the image bearing member or members to form an image thereon; a voltage source for applying an oscillating voltage to the charging member, the oscillating voltage including a first frequency and a second frequency which is different from the first frequency during charging by the charging member.

Abstract: An accurate dielectric breakdown prediction method and a prediction method in which accurate time dependent dielectric breakdown (TDDB) characteristics can be obtained on the basis of dielectric breakdown prediction by a step stress method are provided. In this method, dielectric breakdown is predicted on the basis of a plurality of reference currents in accordance with an applied voltage, or a reference current I.sub.cr is varied as the function of the applied voltage. In the step stress TDDB prediction, a Chen-Holland-Hu model or improved Chen-Holland-Hu model is employed. Since TDDB characteristics can be obtained from only dielectric breakdown prediction, this method is advantageous for early reliability prediction.

Abstract: An organic silicon compound 10 is applied around vibrating electrodes 3a and 3b of a piezoelectric resonant element 1. A compound such as silane, chlorosilane, silazane, silthiane, siloxane, cyclosilane, cyclosilazane, cyclosilthiane, cyclosiloxane, silanol, or metallosilicone is used as the organic silicon compound 10. Around the piezoelectric resonant element 1 and the organic silicon compound 10, for example, an ultraviolet ray curing resin is applied, and the ultraviolet ray curing resin is cured, thereby a permeable film 11 is formed. A cavity 12 is formed around the vibrating electrodes 3a and 3b by dispersing the organic silicon compound 10 to the outside through the film 11. Around the film 11, for example, an outer coating resin is applied, and the outer coating resin is cured, thereby an outer coating material 13 is formed.

Abstract: A charging device for use in an image forming apparatus is disclosed which charges an object to be charged by contacting a conductive charging member with the surface of the object and then applying a voltage across the charging member and the object,wherein at least a contact portion of the charging member comprises a conductive material having a hygroscopic degree of 0.2% or less.

Abstract: In an magnetic brush charging apparatus, a following relation is satisfied, .rho..ltoreq.M/H.ltoreq.1.6 .rho., wherein H is a minimum gap distance (cm) between a cylinder and an image carrying member, .rho. is a density (g/cm.sup.3) of magnetic particles and M is an amount (g/cm.sup.2) of magnetic particles existing in a nip region coming in contact with the image carrying member.

Abstract: A pair of electrodes are biased to produce an electrostatic discharge while placing a thin non electron absorbing gas layer near one or both of the electrodes which are used to develop the electric field. As a result, atmospheric oxygen, water vapor and other contaminants are removed from the regions surrounding the electrodes, allowing ionization to occur more easily. This is accomplished with an electrode structure including a hollow tube for receiving a gas, a plurality of apertures extending through the hollow tube for delivering the gas to the surface of the hollow tube, and the application of a biasing voltage for producing an electrostatic discharge in the presence of the gas. The tube can take the form of a longitudinally extending structure, or a hollow shell, depending upon the configuration of the electrostatic charging apparatus with which the electrode structure is used.

Abstract: A method and apparatus are provided for supplying electric power in the form of an output d.c. voltage. An electret material emits the output d.c. voltage in response to continuously applying a high potential static field across the electret material. In a preferred embodiment, a central member is formed from the electret material and includes two spaced apart, oppositely facing contact surfaces. Two voltage input contacts are separately mounted to the two contact surfaces of the central member, each on opposite sides of an outer portion of the electret material. A static voltage source continuously applies a high static voltage potential across the two voltage input contacts to apply the high potential static field across the outer portions of the electret material. Two voltage output contacts are separately mounted to the two contact surfaces of the central member, on opposite sides of an inner portion of the electret material and spaced apart from the two high voltage contacts.

Abstract: An image forming apparatus includes an image bearing member on which a toner image is formed; transfer material carrying member for carrying thereon a transfer material; a transfer device for transferring the toner image from the image bearing member to a transfer material carried on the transfer material carrying member at a transfer position; a discharging device disposed downstream of the transfer position in a movement direction of the transfer material carrying member for acting on the transfer material on the transfer material carrying member corresponding to separation of the transfer material from the transfer material carrying member, the discharging device includes a first discharger, disposed at a transfer material carrying side of the transfer material carrying member and supplied with a voltage having a DC component of a polarity which is the same as the polarity of the toner image upon an image transfer operation.

Abstract: A charging device for contact-charging a member to be charged. A charging device for charging a movable member to be charged includes a contacting member adapted to contacting the member to be charged, and means for forming a vibratory electric field between the member to be charged and the contacting member, the vibratory electric field forming means applying between the members a vibratory voltage having a peak-to-peak value not less than twice an absolute value of a charge starting voltage to the member to be charged. The member to be charged can be uniformly charged.