Abstract: A semi-automatic exit window cleaner which includes a wiper for contacting an exit window. The wiper attaches to a wiper operation mechanism which swipes the wiper across the exit window when an operator accessed compartment or drawer is moved. Beneficially, the wiper mechanism is comprised of a cable which is spaced between two pulleys, one of which also connects to a gear or other rotation train.

Abstract: An apparatus and method for reliably monitoring the position of a radiant energy beam, for example, a scanning laser beam such as that produced by a raster output scanning system to expose a photoresponsive member, where the beam traverses the surface of a photoreceptive member at a high rate of speed. The apparatus, which includes a lateral-effect photodiode, is also capable of signaling when the radiant energy beam traverses a specific location. The apparatus may also be used to determine the relative intensity of the radiant energy beam, thereby significantly reducing the space and expense necessary to monitor the radiant energy beam by combining multiple sensing operation in a single apparatus.

Abstract: An imaging system is provided for transverse registration of image exposures on photoreceptive belts subject to lateral deviation from linear travel in which a narrow rectangular slit in cooperation with a linear position sensor is used for the detection of lateral belt displacement and circuitry means are provided to generate corrective steering signals to either return the belt to a laterally registered position or to modify the drive input to the particular imager being used to re-register the start-of-scan of the image exposure frames.

Abstract: An apparatus and method for reliably monitoring the position of a radiant energy beam, for example, a scanning laser beam such as that produced by a raster output scanning system to expose a photoresponsive member, where the beam traverses the surface of a photoreceptive member at a high rate of speed. The apparatus, which includes a lateral-effect photodiode, is also capable of signaling when the radiant energy beam traverses a specific location. The apparatus may also be used to determine the relative intensity of the radiant energy beam, thereby significantly reducing the space and expense necessary to monitor the radiant energy beam by combining multiple sensing operation in a single apparatus.

Abstract: The velocity of a photoreceptor belt is measured by sensing the passing of illuminated slits in the belt, as the belt moves in a process direction. Two linear position sensors are positioned so as to view the passing of the illuminated slits. The sensors are aligned in a staggered configuration so that there is an overlap region. The slits are positioned so that as one slit is moving off of a downstream sensor, a second slit is moving over the upstream sensor. The output from an illuminated sensor is alternately switched to the second sensor. The sensor outputs are differentiated to provide an output signal representing a belt velocity. The velocity is compared to said velocity in the belt drive system and error signals generated to compensate for detected changes in the belt velocity.

Abstract: A Raster Output Scanner (ROS) color printer is formed by providing several ROS imagers adjacent image exposure locations of a photoreceptor belt. Each ROS imager forms a separate color image in response to video input signals with each color image superimposed in registration over the previously formed images. Registration in the process direction is enabled by a quad cell photosensor whose output is continually compared to determine whether process registration deviations from a previously established position are necessary. Correction signals are generated in an iterative fashion until a preselected process registration position is re-established. The quad cell detector is also used for a second function; to produce the start and end of scan signals which enable image registration in the cross-process direction.

Abstract: An optical sensing array is adapted to filter incident light so as to generate two output electrical signals from two different portions of the array. The sensing array, which can be a linear CCD array, is assembled with a glass filter overlying the array, the filter being coated with a material which transmits light over a selected wavelength. One portion of the glass filter is uncoated. Thus, a light source incident on the array will activate two separate areas of the array; one underlying the open window and the other underlying the overcoated portion. The results in two different responses over different portions of the wavelength and results in generation of two electrical signals of different levels, representing different detected wavelengths of light. These electrical signals are useful to represent different functions; for example, various characteristics of said background density and size of a document being copied on a xerographic copier.

Abstract: Flash lamp intensity control in which a small preflash lamp first exposes each document on the platen of an electrostatographic machine, a photosensor generates a signal representative of the intensity of the light reflected from the platen, and a controller increases power to the main flash exposure lamps in response to the signal where the measured intensity is less than the normal exposure intensity of the main flash lamps.

Abstract: A ten-element wide angle lens is optimized for projecting full frame images of a document at an object plane onto a photosensitive image plane. The lens has a semi-field angle greater than 38.degree., a relative aperture of f/10, and a magnification range of 0.65 to 1.55. The lens is characterized by improved relative illumination, improved pupil coma, and partial cos.sup.4 illumination falloff compensation.

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: A document handling system in which an air permeable belt advances documents to an imaging station of a copying machine. The belt reflects light rays transmitted thereto except in grooved areas which have been rendered at least partially transmissive to light. These grooved areas contain vacuum apertures in the belt. Semi-circular air channels in the vacuum plenum in concert with the belt apertures provide a means to hold the document to the belt. Light rays transmitted through the partially transmissive grooved areas are reflected from the air channel to back-illuminate the aperture/groove area thereby reducing background shadows associated with these aperture areas. A vacuum system is in communication with the belt for retaining the documents thereon. The vacuum system is arranged to receive the light rays transmitted through the belt and diffusely reflect the light rays incident thereon back through the belt.