Abstract: The ratio of the length of the light path between an original to be copied and a lens to the length of the light path between the lens and a photosensitive medium is changed by the copying magnification changing operation. That is, for example, the lens is brought nearer to the photosensitive medium. After this magnification changing operation, a reference light is thrown upon the photosensitive medium through the lens. The potential of the area of the photosensitive medium illuminated by the reference light is detected, and the output of photosensitive medium charging means is controlled correspondingly to that potential.

Abstract: An image forming process including a step of developing an electrostatic image by supplying a liquid developer to a surface holding said image thereon, which comprises conducting said development when a liquid developer supply member capable, upon elastic deformation thereof, of squeezing out and absorbing said liquid developer is brought into pressure contact with said image-holding surface, and, when said development is not performed, separating said supply member from said surface and maintaining said supply member in a state wetted with said liquid developer. And also an image forming apparatus which is adapted for use in such process.

Abstract: An electrophotographic apparatus is provided with a squeezer for removing unnecessary liquid from a liquid layer formed on a movable photosensitive medium between the step of developing an electrostatic latent image formed on the photosensitive drum by liquid developer and the step of fixing the toner image formed thereby on the photosensitive medium or transferring such toner image to a transfer medium. The apparatus is further provided with a non-contact squeeze power forming device such as a corona discharger or air knife for damming up the unnecessary liquid, and also provided with a liquid layer control member for contacting the liquid dammed up and bulged into a crest-like form so that the thickness of the liquid flowing down the surface of the photosensitive medium is uniform.

Abstract: In an image formation apparatus having a developer for developing a latent image on a recording medium by the use of a liquid developer, there is provided a system for determining the length of the downtime by the concentration of the developing liquid after the downtime, and a device responsive to a signal from the system for generating another signal representing the wait time till the time for starting the formation of the latent image.

Abstract: A device for regenerating developing liquid used in an electrophotographic copying machine of the liquid development type comprises a container for developing liquid. The container includes therein inlet means for admitting used liquid into the container, means for subdividing condensed toner contained in the used liquid, means for filtering the admitting used liquid to pass the subdivided toner therethrough, and outlet means for directing the filtered liquid out of the container.

Abstract: The present invention provides transferring papers for electrophotography which contain specific polymeric compounds and which are particularly useful in transferring by electrophoresis. The specific polymeric compounds are copolymers prepared from one or more monomers represented by the formula: ##EQU1## wherein A is hydrogen or CH.sub.3 ; and B is alkyl, and at least one monomer selected from the group of unsaturated carboxylic acids and acrylonitrile.