摘要:
In a method and apparatus for developing a latent electrostatic image formed on the surface of an image-bearing material by applying a powdery developer thereto, which includes magnetically retaining a layer of a relatively conductive one-component developer having a resistivity of not more than 10.sup.13 ohms-cm on the surface of a developer-retaining member, and bringing the developer on the surface of the developer-retaining member into contact with the surface of the image bearing material, the improvement wherein the developer-retaining member has a resistance, measured by a point-plane resistance measuring method in an environment kept at a temperature of 20.degree. C. and a humidity of 50%, of from 3.times.10.sup.7 ohms to 1.times.10.sup.10 ohms. The improved method makes possible good development without causing a background fog or a tail effect.
摘要:
An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging mechanism and the developing mechanism, and a receptor sheet conveying system for transporting a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism. A support is mounted on the housing so that it is slidable in the forward and rearward directions between its operating position within the housing and its pulled-out position ahead of the housing, and the rotary drum and the developing device are mounted on the support so that they can be separately and independently detached from the support. An electrostatic copying process can be efficiently practiced by using this apparatus.
摘要:
An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing means, and a receptor sheet conveying system for transferring a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism: A support is mounted on the housing so that it is slidable in the forward and rearward directions between its operating position within the housing and its pulled-out position ahead of the housing, and the rotary drum and the developing device are mounted on the support so that they can be separately and independently detached from the support. An electrostatic copying process can be efficiently practiced by using this apparatus.
摘要:
An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing means, and a receptor sheet conveying system for transferring a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism. A support is mounted on the housing so that it is slidable in the forward and rearward directions between its operating position within the housing and its pulled-out position ahead of the housing, and the rotary drum and the developing device are mounted on the support so that they can be separately and independently detached from the support. An electrostatic copying process can be efficiently practiced by using this apparatus.
摘要:
An electrophotograhic copying process forms an electrostatic latent image on the surface of a photosensitive member, developes the image by applying a monocomponent developer to the latent image to form a toner image, transfers the thus formed toner image by contacting a receptor sheet with the photosensitive member to transfer the toner image to the surface of the receptor sheet, fixes the toner image onto the surface of the receptor sheet, eliminates electrostatic charge from the photosensitive member by irradiating the surface of the photosensitive member with an electrostatic eliminating lamp after the toner image has been transferred to the receptor sheet, and cleans the surface of the photosensitive member by removing the developer remaining on the surface thereof. A developer-holding member holds the same kind of developer as used in the developing step on the surface of said developer-holding member by a stationary magnet disposed within the developer-holding member, and the surface of the developer-holding member is moved in a direction opposite to the direction of movement of the surface of the photosensitive member while contacting the two surfaces through the layer of the developer to mechanically brush the surface of the photosensitive member by the layer of the developer. The magnet having a plurality of poles, and the magnetic pole which is located closest to a position at which the surface of the developer-holding member is closest to the surface of the photosensitive member is downstream in the rotation direction of the developer-holding member by a certain angle with respect to the position at which the two surfaces are closest to each other.
摘要:
Disclosed is a magnetic brush development method comprising supplying a two-component type developer comprising a mixture of magnetic carrier particles with toner particles chargeable by friction with the magnetic carrier particles onto a developing sleeve consisting of a non-magnetic sleeve having a magnet installed therein to form a magnetic brush of the developer, and bringing the magnetic brush in sliding contact with the surface of a photosensitive material having an electrostatic latent image formed thereon in the state where a bias voltage is applied between the photosensitive material and the sleeve, whereby a toner image corresponding to the electrostatic latent image is formed, wherein the two-component type developer comprises a ferrite carrier and electroscopic toner particles at a weight ratio of from 4/1 to 20/1.
摘要:
The toner concentration of a two-component type developer including a mixture of a magnetic carrier and an electroscopic toner is adjusted by bringing a magnetic brush of the two-component type developer into sliding contact with a mesh screen to move the electroscopic toner toward the magnetic brush side or the opposite side through apertures of the mesh screen. Apparatus for adjusting the toner concentration in a two-component type developer includes a mechanism for forming a magnetic brush from a mixture of a magnetic carrier and an electroscopic toner and for delivering the magnetic brush. The mechanism includes a support formed of an electroconductive non-magnetic material and a magnet having a plurality of poles and being built in the interior of the support. At least one of the support and magnet is movable. A mesh screen is formed of an electroconductive material and is arranged to support the electroscopic toner on the upper surface side thereof and to have sliding contact with the magnetic brush on the lower surface side thereof. A bias voltage applying mechanism is provided for applying a bias voltage between the support and mesh screen.
摘要:
Disclosed is a development device comprising a development sleeve of a non-magnetic material, a magnet having a plurality of magnetic poles and fixed within the sleeve, a mechanism for rotating the sleeve, a mechanism for agitating a developer composed of a magnetic carrier and a chargeable toner and supplying it to the sleeve, a mechanism for adjusting a magnetic brush formed on the sleeve to a predetermined brush length and supplying it to a development zone, and a mechanism for scraping off the magnetic brush which has gone past the development zone from the sleeve, said magnetic poles consisting of a main pole for development corresponding to the development zone and poles for conveying corresponding to a conveying zone ranging from the position of supplying the developer to the position of cutting the magnetic brush, said magnetic carrier being a ferrite carrier, and each said conveying magnetic pole having a magnetic flux density 50 to 86% of that of the main pole for development.
摘要:
Disclosed is an electrophotographic process which comprises developing an electrophotographic light-sensitive layer having an electrostatic charge image of a certain polarity with a one-component type magnetic developer where positive and negative frictional charge polarities are mingled, under development bias voltage conditions capable of developing the electrostatic charge image, the background or both, and bringing the light-sensitive layer having a developer layer formed thereon into contact with a transfer sheet under a transfer charge of the same polarity as that of the electrostatic charge image when a positive image is formed or under a transfer charge of a polarity reverse to that of the electrostatic charge image when a negative image is formed, to form an image on the transfer sheet.
摘要:
A contact heat fixing device which comprises a driving heated roller having a heating mechanism disposed in the interior thereof and a surface coated with an offset preventing material, a press roller which is rotated in intimate contact under pressure with said heat roller, a vessel for containing therein an offset preventing liquid and a feed mechanism for supplying the offset preventing liquid to the heated roller from the vessel, fixation of a toner image being accomplished by the passage of a support having the toner image thereon through the nip position of the heated roller and the press roller, wherein said feed mechanism includes an applicator for applying the offset preventing liquid to the surface of the heated roller and supply means for supplying the offset preventing liquid from the vessel to the applicator, said applicator being arranged so that it can shift between a position (PI) where it has a pressing contact with said supply means and a position (P2) where it has a pressing contact with said heated roller, in such a manner that the offset preventing liquid is supplied to said applicator when it is at said position (P1), the applicator is moved from said position (P1) to the position (P2) synchronously with feeding of said support to have temporary contact with the surface of the heated roller and apply thereto the offset preventing liquid, and the applicator is then returned to the position (P2).