Abstract: A variable magnification optical apparatus in which an image of an original can be formed on a photosensitive surface at selectively different magnifications. The amount of movement of a lens for changing the imaging magnification is corrected in accordance with the difference between the actual value and the nominal value of the focal length of the lens, namely, the error of the focal length of the lens.

Abstract: A projection device for projecting a first surface onto a second surface comprises a device for forming an image of the first surface on the second surface, a slit provided near the image forming device for making the quantity of light of the light beam on the second surface equal in each portion of the image, a device for moving the image forming device to vary the imaging magnification of the image of the first surface on the second surface, and a device for moving the slit, with movement of the image forming device, to a distance substantially equal to the distance by which the slit has been spaced apart from the image forming device before the image forming device is moved.

Abstract: An apparatus for releasing a sheet-registration mechanism, including primary and secondary register members which cooperates with each other for registering a projected image of an original with a sheet being fed, and an openable cover member located at such a position that is spaced laterally from an apparatus for cooperating with the secondary register member to release the nip between the primary and secondary register members.

Abstract: An electrophotographic copying apparatus includes original supporting device for supporting thereon an original to be copied, illuminating device for illuminating the original, an electrophotographic photosensitive medium movable through a charging station, a developing station and an image transfer station, the photosensitive medium having an image bearing area and a non-image bearing area set thereon, the non-image bearing area being set on the side edge portion of the photosensitive medium, charging device for charging both of the two areas of the photosensitive medium at the charging station, a projection optical system for projecting the optical image of the original upon the image bearing area of the photosensitive medium between the charging station and the developing station to form an electrostatic latent image, developing device for developing the electrostatic latent image into a visible image, image transfer device for transferring the visible image from the photosensitive medium to a transfer med

Abstract: A cleaning device for an image forming apparatus, wherein a magnetic developer image formed on the surface of an endlessly moving image bearing member is transferred onto an image transfer member, which comprises: a cleaning device to remove the magnetic developer remaining on the surface of the image bearing member; a magnetic field forming source situated in the vicinity of the cleaning device to confine the magnetic developer; a magnetic developer absorbing device having a surface to lead the confined magnetic developer from the surface of the image bearing member to a position away from it; a separating and guiding device which separates the magnetic developer from the magnetic developer adsorbing device, and guides the same outside the confining magnetic field; and a developer conveying device which conveys the removed toner in the direction substantially orthogonal to the moving direction of the image bearing member at a position where the confining magnetic field does not extend substantially.

Abstract: A developing device has a rotatable developer holding cylinder and a developing device box for supporting the developer holding cylinder. The developing device box is freely suspended by a holding device, and pressure is resiliently applied to the cylinder so that the cylinder is maintained at a predetermined close distance with respect to a rotatable image bearing member. The position at which the developing device box is suspended is set to a position at which a force component of the driving force transmitting the rotational movement of the image bearing member to the developer holding cylinder acts in a direction in which the cylinder moves away from the image bearing member.

Abstract: An auxiliary exposure device for use in an electrophotographic apparatus is utilized for eliminating unnecessary electrostatic charge from the end portions of the photosensitive member and includes a light reflecting member and light source for auxiliary exposure, wherein the light reflecting member is positioned to maintain the light source and the plane of the original in mutually conjugate relationship, and/or the end portion of the light reflecting member is shaped to match the form of the light beam reflected from the original.

Abstract: A device for supporting and fixing at a predetermined position an optical member such as a lens barrel supporting therewithin a lens or a mirror which takes part in projecting the image of an original to be copied upon a photosensitive medium. The device has a plate member formed with a supporting surface for supporting the optical member by press cutting and an element for pressing the optical member against said supporting surface of the plate member.

Abstract: A lens is fixed in a molded lens tube by a molded fastening ring. The fastening ring has a projection and the lens tube has a notch. The projection is elastically engaged in the notch so that the fastening ring is secured to the lens tube.

Abstract: Apparatus for fixing toner image on a toner image supporting member in electrophotographic copying machine is disclosed. The fixing apparatus includes three rotary rollers which are in contact with each other under the action of pressing means. One of the three rollers has a smaller diameter than the other two rollers. Two rollers with which the toner image supporting member comes into contact are disposed in such a manner that the axes of the two rollers intersect each other and the portion at which the two rollers contact each other or are closest to each other forms a straight line relative to the direction of roller axis. According to one embodiment of the invention, the remaining one roller with which the supporting member does not contact, is formed as a crown roller, that is, a roller which has its largest diameter at the middle portion of the roller.