Abstract: A sensor array is positioned in the optical scanning system of a copier so as to be able to periodically provide a measurement of the degree of image degradation present in the system due to contamination of the optical system components. The sensor array is adapted to measure the modulation transfer frequency of a bar chart which is exposed in the optical system. The measured value of MTF is compared to a predetermined value of MTF representing a uncontaminated measurement at the bar chart. When the comparison indicates that the measured MTF is below a minimum acceptable threshold value, a display is activated to alert an operator that an optic system cleaning operation is required.

Abstract: The present invention is directed to optical imaging systems which utilize linear lens arrays and particularly gradient index lens arrays as the means for projecting light images onto a photosensitive image member. Exposure modulation at the image plane is reduced by oscillating the lens array during an exposure interval, the oscillating period and excursion distance being dependent upon the type of imaging environment the lens is used in. For document copying applications, the requirement for a two-row array to provide minimum exposure modulation is reduced so that a one-row lens array is enabled. For printer and RIS scanning functions, oscillation of a two-row array enables improved system efficiency and hence greater image irradiance and exposure.

Abstract: A color correction system for a color copier is enabled by means of a low resolution RIS unit attached to a light/lens scan system which creates an electronic raster image simultaneously with formation of a color latent image. The RIS output signals are used to modulate the output of a ROS unit which exposes the color latent image to a modulated color correction pattern. Color developer units are enabled to successively develop each color.

Abstract: A reproduction device forms a two-color output copy in a single pass mode. An original document, modified by the formation of a colored fluorescent material on selected portions thereof, is illuminated by a light source. The light reflected from the document is transmitted through a colored filter and is projected onto the surface of a monopolar photoreceptor. Light incident on a fluorescent material is absorbed over a specific wavelength range and is re-admitted at a higher wavelength. This light, and light reflected from the white background, are transmitted through a filter of a color associated with the re-emited wavelength. Light reaching the photoreceptor discharges charged areas thereon at two energy levels. The resulting latent image incorporates three separate discharge levels corresponding to the black image information, color fluorescent areas, and background areas. The black and color areas are developed with appropriate colored toner by developer units biased at the appropriate levels.

Abstract: A printer having a color copy capability is enabled by scanning an original document having at least two discrete colored areas onto a color-filtered photosensor array simultaneously with formation of an electrostatic image of the original on a photoconductor member. The array generates output signals corresponding to detected color areas of the original document. These signals are sent to the printer software which determines the detected color image coordinates of each portion of the output copy. Output copies are then made, using multiple imaging erase and development passes.

Abstract: An imaging system in a copier is modified so as to scan original documents at speeds differing from the image medium speed through the exposure zone so as to anamorphically reduce or enlarge the projected image. A two process scanning operation results in an output image reduced or enlarged in two dimensions. Resolution is maintained by forming an effective imaging width of approximately 1 mm by using a combination of a lens array providing a narrow irradiance profile with an optically aligned slit of smaller width. Magnification values of from 0.50 to 1.5 are thereby enabled.

Abstract: The output of a segmented filament lamp is made more uniform by placing a reflector assembly adjacent the lamp, the reflector assembly having a plurality of spherical segments formed along its length. Each spherical segment is located so as to reflect light from the filaments back to the filament plane to form a real image of each filament in interfilament space. The lamp output thus appears as a uniform and constant source. This type of filament lamp is especially useful in conjunction with an imaging system which requires a very uniform light level at a projection lens or at the surface of a document platen.

Abstract: A document imaging system is compensated for distortion caused by non-planarity in the documents by providing a positive lens with varying power at a location beneath the document platen. In a preferred embodiment, an aspheric fresnel lens is used as the compensating optical element.

Abstract: A multi-mode imaging system provides the capability of reproducing documents in a conventional COPY mode wherein a document is placed on a platen and scanned to create an exposed latent image on a photosensitive member. The system is adapted to operate in a second, print (WRITE) mode wherein an image bar, such as a light-emitting diode (LED) array or a liquid crystal shutter (LCS), is placed into optical alignment with a fixed optical system including a linear lens array. The image bar is electrically addressed to create a light output in an image-wise pattern (LCD) or to change the state of the LCS. The image output is optically coupled into the lens array which projects the image onto the photosensitive member. In one embodiment, the image bar is partially within the end portion of a movable plate.

Abstract: A short focal length lens array has a plurality of lenslets formed within the body of a photosensitive glass. The lenslets have areas which are oriented such that they tilt away from each other from the center out to the array edges. The lens array acts as a reduction or enlargement lens when reproducing objects at an object plane onto an image plane. A one or two row embodiment is disclosed suitable for incremental scanning of a document at image planes. A further full frame lens array is disclosed for providing full frame exposure of a document at various selected magnifications.

Abstract: A reduction/enlargement gradient index lens array is provided which comprises several groups of square-ended fibers, the fibers within a particular group being of the same length. Group fiber length decreases generally from center to the ends of the array. The group are assembled in a characteristic fan-like fashion to form a reduction/enlargement lens array.

Abstract: An exemplary two-row design for a reduction/enlargement gradient index lens is provided. The gradient index fibers of each row are aligned in the length direction so that the fiber axis lies along respective symmetrical planes. These planes are tilted with respect to each other and with respect to a plane normal to the object and image planes by some small angle. The array images objects in an object plane onto an image parallel plane of a magnification dependent on the system parameter. In this configuration, the center fiber of one row is aligned such that a plane extending through the axis of the center fiber in the width direction of the lens makes a right angle with the object and image planes. A further characteristic of the two-row array is that adjacent fibers in adjoining rows are offset to provide the required contiguous image at the image plane and to optimize the exposure uniformly.

Abstract: A two-dimensional full-frame illumination assembly is formed, in a preferred embodiment, by coupling light into the edges of a document platen which has been modified by applying a white segment pattern to the bottom platen surface. The coupled light is totally internally reflected within the platen body except for the area covered by the segment pattern. Light encountering the segments is reflected upward towards the document support surface to provide the required document illumination. The light reflected by the document passes back through the screen segment pattern and is projected by a conventional lens or a full-frame, two-dimensional, short focal length lens array onto a photosensitive surface such as a photoreceptor belt.

Abstract: A compact, two-dimensional full-frame document illumination and imaging device is formed by combining a short focal length imaging area array, such as a gradient index fiber lens area array, with a light source formed in the fiber interstitial areas of the array. The light source is addressed to provide a uniform illumination level at a document platen interface. The full document image is reflected back to the array and projected onto a photosensitive image plane.

Abstract: A full-frame flash illumination and imaging system wherein an illumination mechanism compensates for unwanted charge variations on a photoreceptor belt caused by reflections of the lens from the document platen. The area of the belt upon which the negative lens image is formed is predetermined and a controlled quantity of light is directed towards this area, either before, after, or during exposure, to reduce the charge level of the area, to the degree necessary to compensate for the negative lens image. Several illumination mechanisms are disclosed including a programmable LED array and various mask configurations.

Abstract: A compact, full-frame flash illumination system is disclosed. In a unity mode of operation, a lens, mounted within a light housing, projects an image of a document onto a photoreceptor belt. In a reduction mode of operation, the lens is translated towards the photoreceptor along a non-linear path which maintains document registration at the image plane. Simultaneously, the platen is translated upward by a mechanical drive arrangement to maintain conjugate requirements.

Abstract: A document reproduction system is disclosed which employs an imaging array assembly positioned to transmit reflected images from a document in an object plane onto an imaging plane. The imaging assembly includes a 1X lens array and at least one reduction/enlargement lens array. The overall dimensions of the total imaging area of the reproduction system are reduced from conventional fixed lens or fixed document system by providing means for moving the document, imaging assembly and imaging plane in certain prescribed relationships. These means include a pulley/cable/clutch arrangement which enables changes in velocity relationships which are required for a unity magnification mode of operation as well as those for a reduction or enlargement modes of operation.

Abstract: A reduction/enlargement gradient index lens array is modified to improve image quality and exposure at an imaging plane. In one embodiment, a masking element is placed in the optical path so as to permit minimum light transmitted through optical fibers located at the array ends and maximum light transmitted through the array center. In a second embodiment, a field stop is formed within the body of each fiber to accomplish the same end.

Abstract: An imaging system is disclosed which employs a lens array positioned to transmit reflected images from a document in an object plane onto an imaging plane at a reduction or enlargement value. The document, lens array and imaging plane are moved with respect to each other within certain prescribed and preferred velocity ratios.

Abstract: .[.A symmetrical light intensity distribution profile is achieved by placing a pair of similar asymmetrical linear DC gas discharge lamps in parallel position but opposed in polarity. The individual asymmetrical distributions of the lamps combine in a symmetrical total intensity distribution. A desired "butterfly" or other intensity distribution profile can be achieved..]. .Iadd.The invention relates to an illumination system which provides nonuniform illumination along an object plane in the dimension of an illumination source which includes two linear lamps. The lamps have their anodes and cathodes connected in reverse fashion relative to each other; each lamp provides its own asymmetrical light output distribution pattern but the resultant output of both lamps is a symmetrical pattern which provides the characteristic nonuniform illumination on the object plane. .Iaddend.