Abstract: A unit-type copying machine comprising an upper unit having an optical system for exposing a document to light by scanning, and a lower unit provided independently of the upper unit and having a photoconductive drum to be exposed to an image of the document projected thereon from the optical system. The upper and lower units are provided with connecting portions for detachably connecting the two units together and positioning portions for positioning the optical path of projection of the document image from the optical system in coincidence with an exposure station for the drum. The upper or lower unit is usable with selected one of different types of lower units or of different types of upper units in a suitable combination.

Abstract: A cleaning device in an electrostatic copying apparatus, for removing residual toner particles from the surface of a photosensitive member adapted to move through an endless conveying passage, includes a blade holding mechanism mounted pivotally around an axis extending substantially parallel to the surface of the photosensitive member and substantially perpendicular to the moving direction of the photosensitive member, and a cleaning blade mounted on the blade holding mechanism. The cleaning device further includes a first spring elastically biasing the blade holding mechanism to a non-operating position in which the cleaning blade is away from the surface of the photosensitive member and an operating mechanism selectively positioning the blade holding mechanism against the elastic biasing action of the first spring to an operating position in which the cleaning blade is pressed against the surface of the photosensitive member.

Abstract: A variable magnification electrostatic copying apparatus comprising a transparent plate on which to place a document to be copied, an optical system for projecting the image of the document onto an electrostatographic photosensitive member at any desired projecting ratio selected from a plurality of projecting ratios in an exposure zone located along the moving path of the photosensitive member, and a driving means for moving at least a part of the optical system and the transparent plate relative to each other. The optical system includes at least one position-variable optical element assembly adapted to be held at any of a plurality of positions corresponding to the aforesaid plurality of projecting ratios. The variable magnification electrostatic copying apparatus includes a unique improved means for varying the projecting ratio of the optical system by moving the position-variable optical element assembly.

Abstract: An electrostatic copying apparatus including a support frame having a front support wall and a rear support frame. The support frame is mounted on a housing slidably in the front and rear direction between an operating position within the housing and a pull-out position outside of the housing. A rotating drum and a developing device are mounted on the support frame. Each of the rear surface of the front support wall and the front surface of the rear support wall has a semicircular receiving portion with an open top, and each end of the rotating drum has a shaft bearing member with a circular peripheral surface. By inserting each bearing member into the associated receiving portion, the drum is rotatably mounted. The developing device has a front wall and a rear wall, with a projecting portion formed at the end of each. An abutting lower edge is defined on each projecting portion, and an abutting front edge is defined on each of the front wall and the rear wall, below the projecting portion.

Abstract: An optical device in a variable magnification electrostatic copying apparatus includes a first reflecting mirror assembly mounted for reciprocal movement, a second reflecting mirror assembly mounted for reciprocal movement substantially parallel to the reciprocating direction of the first reflecting mirror assembly, and a speed-reduction interlocking mechanism for moving the second reflecting mirror assembly at a speed equal to one-half of the moving speed of the first reflecting mirror assembly, upon movement of the first reflecting mirror assembly. The optical device further includes a magnification setting mechanism for changing the relative position of the second reflecting mirror assembly with respect to the first reflecting mirror assembly according to a desired copying magnification.