Abstract: Writing boards such as electric blackboards which can erase all information written thereon without wiping the board by hand. On a front surface of an endless recording medium provided in the electric black board letters, characters, etc. are written with a writing tool. The writing tool uses an ink which is easily erasable with a cleaning liquid stored in a container. At the back surface of the recording medium, there is provided a cleaning instrument which faces the back surface of the recording medium. When all the writing is to be erased, an erasing switch is pushed. A pump is operated to move the recording medium, relative to the cleaning instrument. Thus, the cleaning liquid stored in the container circulates through tubes and the cleaning instrument and squeezes the cleaning liquid through an opening of the cleaning instrument to the recording medium.

Abstract: In a wet-type electrophotographic image formation method using an organic electrophotographic photoconductor constituted of an electroconductive support and a photoconductive layer formed thereon, the steps of (1) forming a latent electrostatic image on the photoconductive layer, and (2) developing the latent electrostatic image to a visible toner image with a developer comprising toner particles and a carrier liquid constituted of or including a silicone oil in which the toner particles are dispersed.

Abstract: A wet-type image formation apparatus comprising a latent electrostatic image formation unit capable of forming on a latent-electrostatic-image-bearable photoconductive member a latent electrostatic image corresponding to an original image; and a wet-type development unit capable of developing the latent electrostatic image into a visible toner image with a liquid developer composed of (i) a carrier liquid comprising a petroleum aliphatic hydrocarbon and a silicone oil with a siloxane structure, and (ii) toner particles comprising a coloring agent and a binder resin, which are dispersed in the above-mentioned carrier liquid.

Abstract: A liquid developer for developing latent electrostatic images comprises (i) a carrier liquid comprising at least one component selected from the group consisting of a phenylmethyl silicone oil and a cyclic dimethyl polysiloxane, and (ii) toner particles dispersed in said carrier liquid, and images are formed by a wet-type electrophotographic image formation method using the liquid developer and thermally fixed to a transfer sheet.

Abstract: An image forming apparatus which uses a liquid developer to produce a visible image from an image carrier is provided with a movable cleaning unit. This movable cleaning unit is moved in and out of contact with the image carrier. A tank stores the liquid developer which is fed to both the developing unit and to the cleaning unit and is provided with a mechanism for feeding the developing unit and the cleaning unit with the liquid developer which is so stored.

Abstract: A fixing device applicable to image forming equipment and cable of controlling the amount of silicone oil to be applied to a heat roller. Silicone oil is applied to the heat roller via applicator felt, a second application roller and a first application roller. An upper and a lower scraper blade contact the surface of the second application roller to regulate the silicone oil on the second application roller to a predetermined small amount. While one of the scraper blades so regulates the amount of silicone oil on the second application roller, the other scrapes offset toner particles, paper dust and other impurities off the application roller.

Abstract: A wet-type image formation apparatus comprising (i) a belt-shaped photoconductor prepared by depositing a photoconductive material on the outer surface of a belt-shaped substrate; (ii) a plurality of pulleys which support and drive the belt-shaped photoconductor; (iii) a charging unit; (iv) an exposure unit; (v) a development unit; (vi) an image transfer unit; (vii) a squeeze roller unit, comprising a pair of roller-supporting members and a co-axial roller; (viii) a cleaning means; (ix) a liquid developer removing unit which is provided inside the belt-shaped photoconductor, capable of removing the liquid developer dropping onto the inner surface of the belt-shaped photoconductor and recovering it in a liquid developer reservoir or a development unit.

Abstract: An image fixing unit for a wet-type electrophotographic copying machine capable of forming a latent electrostatic image on a photoconductor element, developing the latent electrostatic image to a visible toner image by a developer comprising a carrier liquid and toner particles and transferring the visible toner image to a transfer sheet, is disclosed, which comprises (a) a non-thermal carrier liquid content reduction device for reducing the content of the carrier liquid in the developer deposited imagewise on the transfer sheet without application of heat thereto; and (b) a thermal image fixing device for fixing the toner image to the transfer sheet by directly heating the toner image formed on the transfer sheet after the reduction of the content of the carrier liquid in the imagewise deposited developer by the non-thermal carrier liquid content reduction device.

Abstract: An image fixing method for use in a wet-type electrophotographic copying machine is disclosed, which comprises the steps of: (1) developing a latent electrostatic image formed on an electrophotographic photoconductor element to a visible toner image by use of a developer comprising a thermal cross-linking toner and a carrier liquid, (2) transferring the visible toner image to a transfer sheet having an oil absorption coefficient .alpha. of 1.0.times.10.sup.-2 cm/sec or more, which is assessed by dividing the thickness of the transfer sheet by the time required for a drop of the carrier liquid placed on the front side of the transfer sheet to spread to a diameter of 1 cm on the back side of the transfer sheet, to form a transferred image on the transfer sheet, and (3) fixing the transferred image to the transfer sheet by bringing a heat application means into direct contact with the transferred image.

Abstract: A wet type image forming apparatus which comprises: at least one rotary photoconductor drum having a surface on which an electrostatic latent image is formed; a development unit for forming a visual image from the latent image by supplying the photoconductor with a liquid developer; a transferring portion under the photoconductor drum where the developed visual image is transferred to a paper; a cleaning unit for removing the liquid developer which remains on the surface of the photoconductor after the visual image is transferred to the paper. The apparatus further comprises a drip prevention plate which is arranged to come in contact with the photoconductor surface to prevent the liquid developer from dripping through the photoconductor surface. The developer is prevented from dripping onto the transferring portion so that the paper is not stained by the dripped liquid developer.

Abstract: A developing replenisher material or a replenisher liquid developer to be supplied to a developer tank of an electrostatic copying machine comprises 1000 parts by weight of a carrier liquid composed mainly of aliphatic hydrocarbon and 200 or 1200 parts by weight of toner particles composed mainly of a binder resin and a pigment. The toner concentration of the replenisher liquid developer is high enough to prevent an overflow from the developer tank, allow many copies to be produced by the copying machine, and prevent a solvent shock. The toner particles, when added to the carrier liquid, can immediately and well be dispersed in the carrier liquid.

Abstract: A device applicable to an electrophotographic color copier or a color ink jet printer for selectively supplying visualizing liquids of different colors, e.g. black, red, green and blue or a mixture thereof to a photoconductive drum, paper or like recording medium to form a visible image on the medium which corresponds to an image of an original document. The device includes a black liquid vessel, a red liquid vessel, a blue liquid vessel, and a cleaning liquid vessel. The liquids from the various vessels are selectively fed to the device and, after a visualizing operation or a cleaning operation, selectively returned to the respective vessels by two switching units. Residual toner particles are returned to the black liquid vessel. A purifying member for capturing toner or like visualizing agent which is contained in the black liquid is situated between an overflow port of the black liquid vessel and the other liquid vessels and cleaning liquid vessel.

Abstract: An apparatus for forming multicolor electrophotographic images through a wet-type developing process has charging, exposure, development, transfer, and cleaning devices disposed around a rotatable latent image carrier. The development device has at least one roller disposed in confronting relation to the latent image carrier, and a development housing in which the roller is rotatably disposed. During the developing process, the development device is supplied with a desired one of liquid developers of different colors stored in respective liquid developer tanks.

Abstract: A method and apparatus for making a two-dimensional copy from either a two-dimensional or three-dimensional object is provided. In making a two-dimensional copy from a three-dimensional object, the object is submerged in the liquid contained in a container having a transparent bottom portion to which the object is brought into contact by placing a cover member thereon. The object is then exposed through the transparent bottom portion thereby the projected image of the object viewed through the transparent bottom portion is reproduced on a sheet of copy paper.

Abstract: A heat-fixing device includes a heat plate along which a transfer medium bearing thereon a toner image is advanced during which the toner image becomes fixed to the transfer medium by fusing, the heat plate including a plurality of heating sections arranged along the direction of advancement of said transfer medium each of the heating sections being provided with at least one electrical heater. The device also includes a control circuit for controlling the operation of the heaters such that, under a non-steady-condition, only selected ones of the heaters are set in operation thereby only the corresponding heating sections are positively heated; whereas, under a steady-state condition, all of the heaters are operated at the same time thereby maintaining all of the heating sections at a predetermined temperature.

Abstract: Acrylamide polymers having remarkably high molecular weights can be obtained by polymerizing acrylamide or a monomer mixture comprising a preponderant quantity of acrylamide in an aqueous medium with the use of a specific redox initiator and a specific azo compound initiator. The polymerization initiator used in this porcess comprises a combination of a persulfate, formaldehyde sodium sufoxylate and 2,2'-azobis-2-amidinopropane.

Abstract: A method and apparatus for making a two-dimensional copy from either a two-dimensional or three-dimensional object is provided. In making a two-dimensional copy from a three-dimensional object, the object is submerged in the liquid contained in a container having a transparent bottom portion to which said object is brought into contact by placing a cover member thereon. The object is then exposed through the transparent bottom portion thereby the projected image of the object viewed through the transparent bottom portion is reproduced on a sheet of copy paper.

Abstract: A developing unit for use with an electrophotographic copying apparatus of the type comprising a developing electrode and at least one corona discharger includes a conductive member arranged within a shield casing of the discharger for obtaining a voltage to be applied to the developing electrode as a bias voltage thereto. In the case where an a.c. discharger for charge elimination is being used in addition to the primary discharger, conductive members are incorporated with respective dischargers and the outputs from the conductive members are superimposed on each other and applied to the developing electrode. In this instance, the output of the conductive member associated with the a.c. discharger is continuously applied to the developing electrode after the de-energization of the primary discharger, i.e., the completion of developing an electrostatic latent image to thereby prevent the deposition of toner on the developing electrode.

Abstract: An image transfer material separation apparatus for an electrophotographic copying machine, in which a leading edge of an image transfer material is curled in such a direction as to be separated from the surface of a photoconductor on which a latent electrostatic image or a visible image is formed, before the image transfer material is brought into close contact with the latent-electrostatic-image- or visible-image-bearing photoconductor, and after image transfer, an image transfer material separation member, disposed away from the surface of the photoconductor, is pushed by the curled leading edge portion of the image transfer material, whereby the image transfer material is guided in the direction different from the movement direction of the photoconductor and is separated from the surface of the photoconductor and is then transported, for instance, towards an image fixing station.

Abstract: An apparatus for forming multicolor electrophotographic images through a wet-type developing process has charging, exposure, development, transfer, and cleaning devices disposed around a rotatable latent image carrier. The development device has at least one roller disposed in confronting relation to the latent image carrier, and a development housing in which the roller is rotatably disposed. During the developing process, the development device is supplied with a desired one of liquid developers of different colors stored in respective liquid developer tanks.