Abstract: An electrophotographic copier selectively operable with various kinds of toner automatically sets up optimum copy process conditions for any particular characteristic of toner to be used when a toner cartridge is replaced. The copy process conditions are changed upon the lapse of a predetermined delay time after the replacement of a toner cartridge. When an old toner cartridge mounted on the copier is replaced with a new toner cartridge which stores toner of a kind that should not be mixed with toner stored in the former, the copier identifies the new toner cartridge and produces an alarm to inhibit the replacement.

Abstract: A machine has a control panel with a plurality of keys controlling various functions. A display exhibits prompts as to the proper operation of the machine. An operator can learn the functions of the keys by manipulating them and observing the resulting prompts. The display additionally exhibits maintenance and (in a diagnostic mode) diagnostic prompts. Sensors respond to various maintenance or diagnostic conditions. Signals from the sensors cause a storage means to supply corresponding prompts to the display to prompt the needed maintenance or diagnostic procedure. When the appropriate procedure has been performed, additional prompts for subsequent procedures will be displayed if appropriate.

Abstract: A power supply control device for a copier of the type having a timer therein is disclosed. The device allows a power supply of the copier to be turned on and off at any desired time which is set through ten keys. Data entered through the ten keys are loaded in a store. The data read out of the store and present time data output from the timer are compared and, as they compare equal, a power supply driver turns on the power supply. Guidance displays are referenced in the event of entering data.

Abstract: A copier with an image editing function which extracts desired areas of a plurality of documents in an analog fashion and allows them to be edited on a single transfer sheet. The copier includes an erasing device for selectively erasing an image provided on a photoconductive element, a detaining device for temporarily detaining a transfer sheet, an image inputting device for inputting an image of an original document, and a display device for displaying an input condition. Desired areas of documents are specified and edited with the aid of displays and then copied. Where the specified areas of the documents overlap each other, one of them having priority over the other or a selected one of them is copied. The number of areas to be edited is open to choice. The specified areas are entered through editing keys and usual ten keys. The erasing device is driven by a controller which is responsive to digital signals which are derived from position setting knobs associated with two perpendicular scales.

Abstract: After a photosensitive drum is cleaned of residual toner by a scraper blade, a lubricant film is applied to the drum to maintain the coefficient of friction between the drum and blade constant and thereby ensure efficient cleaning and printing density without damage to the drum. The film forming material is in the form of a block and is applied to the drum by a rotary brush. The brush is selectively moved into and out of engagement with the drum to control the amount of film application. The engagement of the brush with the drum is controlled in accordance with a sensed parameter such as a number of copies produced, the coefficient of friction between the drum and a sensor blade, etc.

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 auto-bias developing process for developing an electrostatic latent image formed on a photosensitive member which includes the step of storing a detected potential in order to apply a fixed bias potential to a developing electrode plate wherein the surface potential of a photosensitive member is detected through a developing solution by a sensor electrode, and is stored in a memory circuit for subsequent conversion to a fixed bias potential which corresponds to the detected potential and is applied to the developing electrode. The process also includes the step of removing any toner which attaches to the developing electrode plate, by the application of a reverse bias potential thereto when the developing process is not taking place and the step of rendering the developing electrode plate electrically floating for removing toner from the plate and preventing deposition of toner onto the surface of the photosensitive member.

Abstract: A spongy roller is rotated so that the surface thereof is pressed against the surface of a photoconductive drum and moves in the opposite direction therefrom. A resilient blade is also pressed against the photoconductive drum downstream of the roller so as to define a trough therebetween into which is supplied a cleaning liquid. The roller and blade remove all residual toner substance from the drum which remains after development and transfer operations. The cleaning liquid is supplied only while the drum is being operatively rotated in a quantity sufficient to wash away substantially all removed toner substance from between the blade and the drum. The roller is large enough to absorb enough cleaning liquid to remain moist and prevent solidification of removed toner substance between the roller and the drum between copying operations and when the apparatus is shut down.

Abstract: A developing process for electrophotography and an apparatus for carrying out the process in which a developing electrode is arranged in opposing relationship with a photoconductive member having an electrostatic latent image formed thereon such that a potential corresponding to an average potential of the latent image is produced on the electrode by either induction or resistor chain. The potential on the electrode is, however, controlling so as to be maintained, through a constant voltage element such as a varistor, above a given voltage slightly higher than, or equal to, the lowest potential on at least a portion of the member which is assumable in forming any type of latent images on the member so as to reproduce copies of good quality even from a very light or low density image on an original document to be copied.

Abstract: The electrophotographic copying machines are of the type in which a photosensitive drum is removable from the machine, for inspection or other purposes, through an opening formed in a sidewall, which opening is normally covered by a coverplate. Plural cleaning devices which are normally maintained in pressing engagement with the peripheral drum surface, are automatically released from such engagement once the coverplate has been dismounted from the sidewall and also returned to the original position as the coverplate is remounted, thereby preventing damage of the drum as well as a wrong usage of the machine which may be caused by inadvertently failing to reset each cleaning device.