Abstract: A document registration system is disclosed which enables documents of various sizes to be registered at different corner registration positions on a platen and to be projected onto a photoreceptor so that the projected images have one side aligned along a common edge parallel to the edge of the photoreceptor. A lens drive and control circuit is provided for determining lens position, comparing it with a home position and moving the lens to a new position associated with the particular registration and magnification.

Abstract: An illumination housing includes a glass platen for supporting a document, the platen having at least one surface area uniformly roughened. In one embodiment, both surfaces are uniformly roughened by an etching process. The surface of the platen are thus rendered diffusely reflective to specular hot or cold light spots formed by light reflected from optical components within the illumination system and compensates for platen-derived specular reflections into the projection lens.

Abstract: An electrophotographic printing system incorporates two sets of moving optical components, one on each side of a projection lens. A document on a platen is scanned by a first set of moving mirrors with the scanned image projected by a lens towards a photoreceptor. A second set of moving mirrors precesses the image onto the photoreceptor. In one embodiment, a drive system commonly drives both the object side and the image side mirrors to provide the required document scan and precess motions. In a second embodiment, the image side system is driven as a function of the photoreceptor (process) speed.

Abstract: A two-dimensional full frame illumination and imaging assembly is formed, in a preferred embodiment, by joining, in combination, a platen, platen housing extension and full frame lens array. The combined assembly is converted into a higly efficient, light directing cavity by making the sides of the platen and platen housing diffusely reflective. The top surface of the lens array, excluding the lenslet entrance aperture, is also made reflective. Light is then coupled into the housing through an aperture formed in at least one of the sides. The light undergoes multiple reflections from all sides of the assembly, providing illumination of the document whose relfection is transmitted by the lens array onto a photosensitive image plane.

Abstract: A flash exposure optical imaging system is provided which includes a light housing having a movable top and bottom surface. The top surface contains a document platen, the bottom surface a fixed, wide-angle projection lens. These surfaces are vertically translated past a fixed, central housing wall to vary the system conjugate in response to changes in magnification. In a preferred embodiment, a pair of football shaped cams are rotated in response to position signals from a controller initiated by a magnification change. A pair of T-bars and linkage mechanisms are associated with these cams and their motion provides simultaneous vertical motions to the top and bottom housing surfaces, respectively.

Abstract: The present invention is directed to a precession scanning system wherein a platen moving in a first direction is scanned by a scan illumination assembly and lens moving in the opposite direction. The projected image is precessed onto a moving photoreceptor belt in a direction opposite the belt motion. The velocity relationship between platen, lens, scan illumination assembly and photoreceptor, as well as scan distance, are governed by a unique set of relationships.

Abstract: The invention discloses the use of a corrector element placed in an imaging system to selectively vignette energy emanating from the exit pupil of a lens as a function of the field angle of the lens. Several imaging systems are disclosed which illustrate the technique used in determining optimum design and location of the corrector elements.

Abstract: An optical system is provided for a copying apparatus which includes a plurality of components whose displacements relative to each other can be made to yield differing magnification at an imaging plane. In particular, during a magnification mode a dual rate scanning mirror pair is displaced a fixed distance and a catadioptric lens is displaced an identical distance, from their normal 1x positions. A third mirror, located at the photoreceptor plane is displaced a second distance. The displacements are a function of the magnification, the lens focal length and the angular displacement of the lens. All displacements are parallel to the document plane, resulting in a compact scanning system.

Abstract: A pair of lenses, side by side, create twin optical paths for image projection from a single object station to twin photoreceptor drums, rotating in opposite directions. The lens pair, as it moves back and forth, is scanning in both directions and alternately projecting onto one and the other of the two photoreceptors.

Abstract: A folded optical system for scanning an object and projecting its image in four modes of operation. In one mode, a stationary object is scanned by moving mirrors and its conjugate image projected at unity magnification onto a moving image surface. In a second mode, conjugate distances are varied to project an image at other than unity magnification. In a third mode, the optical system remains stationary and the object is moved relative to it to enable imaging of objects larger than the scan travel of the optics. In a fourth mode, the optics again remain stationary and an add-reflector is introduced to create a reflection cavity to increase the object conjugate for minified imaging of large moving objects. Mirrors and lens are movable to effect magnification changes.

Abstract: A reproducing apparatus having a plurality of modes of operation. The apparatus includes a moving imaging surface. In a first mode of operation a stationary document is viewed and an image thereof is projected onto the imaging surface. In a second mode a document moving at a first speed synchronized to the speed of the moving imaging surface is viewed, and an image thereof is projected onto the imaging surface at a desired magnification. In a third mode a document moving at a second speed synchronized to the speed of the moving imaging surface is viewed and an image thereof is projected onto the surface at a reduced magnification. An arrangement for selecting the desired mode of operation is provided.