Abstract:
An apparatus and method for transferring xerographically printed information on a piece of paper (102) to an ultraviolet sensitive medium (101). The paper (102) can be optionally treated with a chemical (207) to enhance ultraviolet light transmission through the paper (102). The paper (102)/medium (101) assembly may be advanced via nip rollers (432, 433) at a predetermined rate so as to optimize time of exposure to the ultraviolet light source (410).
Abstract:
Transition-encoded font image information--being a form of information flagging all pixel displacement locations upon a scan line of a raster scanning image generator, nominally a laser printer, whereat a marker, nominally a laser beam, transits from marking white to marking black, and from marking black to marking white, during the generation of the one scan line of a font image--is stored in two random access memories (RAMs) each having a nominal 10,320+ address corresponding to the 1200 pixel positions per inch across an 8.6" scan line. The two RAMs are sequentially read in parallel from the start-of-scan of the scanning marker, or laser beam. The successively read transition-encoded information is used to decrement a counter upon each black-to-white transition and to increment the same counter upon each white-to-black transition. The sign bit of the count within the counter is used to control the on/off, black/white condition of the laser beam marker so that white is imaged upon the scan line when the counter is negative, and so that black is imaged when the counter is positive, at pixel rates to 35 MHz.
Abstract:
An imaging apparatus modulates or gates pluralities of light beams through individual light valves, thereby providing a greater number and finer resolution of modulated light beams without increasing the number of light valves or decreasing the spacing between adjacent light valves. A two-step modulation process is used, the first step being performed by a light generator incorporating a polygon mirror that selectively illuminates selected bundles of fiber optic strands. One strand from each bundle is routed to illuminate one of the cells in a light valve array, such that when a bundle is illuminated, every cell is illuminated by a strand from the illuminated bundle. The second step of the modulation process involves controlling the light valve array to modulate the light beams formed by the illuminated strands at each cell. Further, by ganging together multiple light valve arrays, a composite scan line may be created which spans across the width of several scan lines generated by the individual light valve arrays. The result is finer resolution and greater imaging speed utilizing far fewer light valves.
Abstract:
An electro-optic imager, used for exposing photosensitive media, wherein a moving drum or mirror(s) are used to obtain a scanning action, and a plurality of scanning beams is preferably used. An encoder, preferably a radial optical ruling and two or more optical interrupters, is attached to a shaft connected to the moving drum or mirrors which cause the optical scanning action. The output from the interrupters is processed in circuitry which interpolates position, generating clocks much faster than the rate of signals received by the interrupters, and responding quickly to any speed changes which might occur.
Abstract:
Transition-encoded font image information is a form of information flagging all pixel displacement locations upon a scan line of a raster scan image generator, nominally a laser printer, whereat black to white, and white to black, transitions occur during generation of the one scan line of a font image. Transition-encoded information for plural, superimposed, font images may be combined prior to generation of a synthesis image. In this combination of transition-encoded information for generating superimposed font images the flags representing transitions must not be overwritten, there being a limit that a single scan line pixel position must either transit black to white, transit white to black, or maintain the state of the previous pixel. The combining of transition encoded information encodes transitions for these one or ones of addresses (pixels) wherein two flags would otherwise overlap so that the total transitions within the combined font information are preserved. This is accomplished by ripple shifting the position(s) of the transition(s) flag(s) within the second font image information which have identical positional correspondence with transition(s) flag(s) within the first font image information so that the flag(s) are slightly relocated within the combined font image information.
Abstract:
Integrations of the historical numbers of times that a light beam scanned in an oscillatory course by a self-resonant galvanometer scanner does traverse so far in a first direction so as to impinge upon a Beginning-of-Trace (BOT) sensor, and does traverse so far in the opposite direction so as to impinge upon an End-of-Trace (EOT) sensor, are each used to separately control the voltage level developed in a first, BOT, electrical tank circuit and in a second, EOT, electrical tank circuit. Voltage from each tank circuit is amplified and applied to drive the self-resonant scanner, at a polarity to induce continued oscillation, during one-half of each oscillatory cycle. Amplitude and centering control thereby obtained of the sinusoidal oscillation of the self-resonant scanner is repeatable to better than one part in ten thousand between cycles.
Abstract:
Data clocking circuitry providing data clocking signals usable to control the output of a laser directed to a self-resonant mirror of a scanning apparatus. The circuitry selects clock signals from the output of a stable clock in accordance with a program stored in a memory and with the output of a voltage controlled oscillator (VCO) used to provide the data clocking signals with the VCO provided with a control signal based on the difference in the accumulated count between the selected clock signals and data clocking signals.
Abstract:
An electro-optic imager, used for exposing photosensitive media, wherein a modulator, e.g. an array of PLZT light valves, is used to modulate one or more light beams. Temperature control is applied to the modulator to reduce or eliminate variations in response characteristics which would otherwise change the color balance of the final print from the desired color balance.
Abstract:
An electro-optic imager, used for exposing photosensitive media imagewise, wherein an array, e.g. two or more linear arrays, of light sources are imaged onto a rotating drum, to produce images in bands. Apertures are used to shape the beam energies. The use of two or more linear arrays with interlaced imaging allows aperture shapes to be used which precisely control the region of overlapping exposures. With properly shaped apertures, scanning artifacts (e.g. aliasing) can be nearly eliminated.
Abstract:
An electro-optic imager, used for exposing photosensitive media imagewise, wherein a linear array of scanning elements is scanned across a portion of the image, to produce a first region or band of image or information, and then translated in a direction parallel to the linear axis of the scanning elements for another scanning operation to produce a subsequent band, slightly overlapping the previous band. The translation, relative to the photoreceptor, of the scanning array is made very reproducible by establishing the position of a moving member by reference to that of a stationary notched or indented member or members, and the resultant image is made very uniform by adjusting the data controlling the imager within the region of redundant imaging to compensate for minor but known imperfections in this stationary member.