Abstract: An electrophotographic apparatus comprising a photosensitive drum applied with a main transfer bias voltage which is adjustable and a transfer roller applied with an auxiliary transfer bias voltage which is also adjustable.

Abstract: An electrophotographing method for use in a copying apparatus employing a sensitizing screen having a great number of fine apertures, made in a drum shape, and a transferring means having a conductive base plate and a charge storage layer formed on the base plate. The transferring means is constructed in the form of a drum. During the process of obtaining a great number of copies from a primary electrostatic latent image which has been stored on the sensitizing means, a secondary electrostatic latent image is formed and regenerated on the transferring means from the stored primary latent image.

Abstract: The recording device has a heating unit operated and controlled to a predetermined operating temperature, the start of the recording device is governed so as not to operate the heating unit before its temperature reaches a predetermined operating value, the starting of the recording device is permitted prior to a certain time before the temperature of the heating unit reaches the predetermined operating value after the power supply is energized source for the recording device.

Abstract: An electrophotographic apparatus comprising a corona charger, a photosensitive and electrostatic-charge retentive drum including an electrically conductive substrate and a photosensitive layer having a narrower width than that of a record paper, and a screening member inserted between the corona charger and a peripheral part of the photosensitive and electrostatic-charge-retentive member for gradually decreasing a quantity of electrostatic charge charged at side edge portions of the photosensitive layer in a direction toward the side edges of the photosensitive layer, whereby black line and stripe can be prevented from appearing along the side edges of the record paper.

Abstract: An electrophotographic apparatus which makes use of a circuit arrangement connected and arranged such that unless a manuscript to be copied passes through a manuscript detector, a gate circuit functions to prevent a copy starting pulse from passing therethrough, thereby preventing initiation of a new copying operation.

Abstract: Charged neutralizer apparatus including a charge neutralizing brush which is formed thin conductive wires brought into proximity with a charged body to cause a discharge thereof is disclosed herein. A spacer member is provided to prevent direct contact between the thin conductive wires and the charged body and defines a narrow clearance therebetween. The brush is disposed in a movable manner and adapted to move under its own weight or by biasing means, in following relationship with the changed body to thus enable an elimination of charge at any position of the charged body.

Abstract: An electrographic apparatus comprising a main body, a manuscript discharge tray, a slit light exposure portion, a manuscript feed mechanism including upper and lower feed mechanisms, the upper feed mechanism being arranged movably with respect to the lower feed mechanism, a photosensitive body, a sheet manuscript edge guide, a thick manuscript edge guide and means for automatically changing the two edge guides in response to a movement of the upper feed mechanism with respect to the lower feed mechanism; the apparatus being constructed and arranged such that in the case of obtaining copies of a sheet manuscript the sheet manuscript is fed by the manuscript feed mechanism under a condition that the upper feed mechanism is mounted on the lower feed mechanism and scanned by exposed light by one time and in the case of obtaining copies of a thick manuscript a thick manuscript carriage on which is disposed the thick manuscript is fed by the lower feed mechanism under a condition that the upper feed mechanism is mo

Abstract: An electrophotographic process comprising uniformly charging a composite photosensitive body with a charging polarity exhibiting a response property to a visible light, said composite photosensitive body being composed of a photoconductive semiconductor for producing carrier when illuminated by the visible light and a light transmitting organic photosemiconductor superimposed one upon the other, illuminating the charged composite photosensitive body with a light image by the visible light and producing thereon a first electrostatic latent image and producing thereon a second electrostatic latent image based on said first electrostatic latent image, said second electrostatic latent image having a polarity which is opposite to said charging polarity.

Abstract: A filter assembly for use in an electrophotographic copying machine to collect used toner which is swept off a member carrying an electrostatic latent image, by means of a rotating brush comprises a filter unit having a toner receiver and a filter holder which are integrally formed together. The filter holder carries a filter element or elements therein, and the toner receiver allows the toner which falls down in front of the filter element to form a pile thereon. The unit is detachably mounted on the copying machine. A labyrinth seal is formed between the unit and the machine when the unit is mounted in place.

Abstract: An electrographic apparatus comprising a photosensitive screen composed of an insulating layer, two electrically conductive layers coated on opposite sides of the insulating layer and a photosensitive layer coated on one of said electrically conductive layers, and a bias electric source connected between the two electrically conductive layers and producing, on a dielectric coated record sheet, an electrostatic latent image corresponding to an image to be reproduced is disclosed. The apparatus comprises means for adjusting a bias voltage supplied from the bias electric source and applied between the two electrically conductive layers.

Abstract: A corona charger for improving efficiency of utilizing the corona charging current and being able to effect high speed and uniform charging by providing an additional grid electrode applied with a bias voltage between the other grid electrode so as to accelerate the passing of the corona ion stream through openings of the grid electrodes.

Abstract: An electrophotographic sensitizing screen having a great number of apertures, wherein at least an insulating layer and a conductive layer are successively formed on a conductive mesh, is disclosed. These apertures are regularly arranged at such an angle as not to produce moire fringes with respect to a light image projected on the screen.

Abstract: A photosensitive screen for an electrographic apparatus adapted to modulate a flow of corona ions by an electrostatic latent image produced thereon is disclosed. The photosensitive screen is composed of an electrically conductive mesh which is coated on one side with an insulating layer and an electrically conductive layer superimposed one upon the other in the order as mentioned and coated on the other side with a photosensitive layer.The photosensitive screen comprises further an insulating thin film layer which covers at least the electrically conductive layer for the purpose of protecting it against surrounding atmosphere and hence improving durability thereof.

Abstract: A method for printing a great number of duplicated copies of an original with the aid of the same and single master comprises(1) a step for forming on a photoconductive member such as a zinc oxide paper a primary electostatic charge latent image corresponding to an image of the original by subjecting the member to a uniform charging and an imagewise exposure;(2) a step for developing the primary latent image with dry toner particles such as a two component developer having high resistance to form a primary toner image;(3) a step for fixing the primary toner image by flash light having visible light removed therefrom or solvent gas in such a manner that the photoconductive property of the member can be retained to form the master;(4) a step for subjecting the master to a uniform charging and a uniform exposure in succession to form a secondary electrostatic charge latent image on the master;(5) a step for developing the secondary latent image with toner particles to form a secondary toner image on the master;(

Abstract: An electrophotographic sensitizing screen having a great number of apertures, wherein at least an insulating layer and a conductive layer are successively formed on a conductive mesh, is disclosed. These apertures are regularly arranged at such an angle as not to produce moire fringes with respect to a light image projected on the screen.

Abstract: In the electrophotographic apparatus for printing one or more copies of a document, a photoconductive drum rotates at a constant velocity while being charged; a document feeding device advances a document through a light exposure portion at a constant speed and, an optical device projects an image of the exposed document onto the drum to form an electrostatic charge latent image thereon. A latent image is developed to form a toner image after which the toner image is transferred onto a record paper and the toner image is fixed on the record paper to form a final copy. Clock pulses in synchronism with the rotation of the photosensitive drum are produced, whereby master and slave timing pulse generators receive the clock pulses to produce timing pulses. Then a control device receives the timing pulses and produces control signals necessary to control the operation of the apparatus.

Abstract: An electrographic apparatus which can obtain any desired number of copies of a manuscript by scanning it only one time by exposed light and which comprises a manuscript feed mechanism including upper and lower side feed mechanisms arranged above and below a manuscript feed path defined by a slit light exposure portion which projects a manuscript image therethrough, said upper side feed mechanism being movable with respect to said slit light exposure portion to define thin and thick manuscript feed paths, respectively.

Abstract: A toner cleaning apparatus for use in an electrophotographic apparatus having a rotatable photosensitive drum, a corona charger for uniformly charging or electrifying the photosensitive drum, an optical system for projecting an image of a document to be duplicated to form an electrostatic latent image, a biased magnet roller type developing device for developing the latent image with a dry toner to form a toned image, a rotatable transfer roller for transferring the toner image onto a record paper which is synchronously fed between the drum and the roller, and a fixing device for fixing the toner image onto the record paper. A first exclusive cleaning device such as brush type and blade type cleaners are arranged between the transfer roller and the corona charger and a switching device for changing a bias voltage applied to the developing device cooperates therewith such that the developing device is selectively operated as a developing device and a second cleaning device.

Abstract: An ozone removing device for electrographic apparatus comprising a photosensitive screen and a corona discharge device for producing a harmful ozone is disclosed. The device comprises a casing substantially hermetically surrounding said photosensitive screen, an air circulating device for circulating an air stream through said corona discharge device in said casing and a catalyst device arranged in said air circulating device and for decomposing ozone produced from said corona discharge device, whereby said ozone is sucked into the outside of said casing by means of said air circulating device and decomposed and then flowed back into said casing again.

Abstract: A cleaning device for an electrophotographic apparatus including a cleaning brush for cleaning unnecessary residual toner particles adhered to an electrostatic latent image retentive member, a cleaning fan for obtaining an air flow to suck the toner particles scraped by the brush and a filter for collecting the sucked toner particles is disclosed. The cleaning device comprises a path of the air flow for sucking the toner particles being made thick at the vicinity of the filter thereby to slow down a speed of the air flow, to easily catch the toner particles by the filter and to drop down the toner particles in front of the filter, and a toner reservoir being provided for collecting the toner particles dropped in front of the filter.