Abstract: There is a provided method for use with a printing system in which a second halftone pattern is selectively substituted for a first halftone pattern. The printing system preferably buffers one or more of print jobs and places each of the one or more print jobs in a print ready format. The printing system further includes a processing system in which the placing of the one or more print job into the print ready format is performed, as well as a halftone substitution subsystem for selectively operating on one or more halftone patterns which reside in one of the one or more print jobs.

Abstract: In an image input terminal for deriving an electronic representation of the image, including a platen for supporting a document to be scanned, a scanning system including an illumination source for illuminating a document supported on the platen, an array of photosensitive elements which produce an electrical response to sensed reflected light, an arrangement for directing light reflected from a document to the linear array, and an arrangement for providing relative motion in a slow scan direction between the linear array of photosensitive elements and the document, there is provided an arrangement for rotating the scanning system of photosensitive elements and an illumination source about a rotational axis, by an amount corresponding to detected skew of the image, so that, upon relative movement of the linear array of photosensitive elements and the document, the effects of skew in the slow scan direction are removed from the electronic representation of the image.

Abstract: An illumination output from a fluorescent lamp used in a RIS type scanner is maintained at optimum by monitoring the lamp's on/off state and turning the lamp on for a time period following a specified cumulative off time. In one example, the lamp is turned on for a two minute interval following a one hour off time. Following the two minute on period, a diagnostic test is automatically performed to determine whether variations in the lamp output have resulted in an out of specification condition requiring that the lamp be recalibrated to the photosensor array. The calibration is automatically enabled by adjusting the gain of the photosensor array until the photosensor response is within the nominal percentage range. The scanner is then returned to a standby mode. All of the tests are performed automatically and normal operations can be accomplished while the lamp is in warm up phase.

Abstract: A fluorescent lamp utilized in a document scanning system is environmentally and thermally stabilized by means of a bifurcated heater control assembly. A heater blanket is wrapped around the entire surface of the lamp including the end areas surrounding the filaments but exclusive of the aperture through which light is emitted. The size and temperature of the lamp cold spot are selected emperically to maximize output power and minimize illumination transients during power on. The heater jacket has thermostat control set points, which, in both the lamp standby and energized states, maintain the blanket and lamp assembly at a constant elevated temperature which is above that achieved by lamp heat alone. Since the temperature distribution is always determined by the blanket and never by the lamp, changes in temperature or temperature distribution (and hence illumination distribution) as the lamp transitions from standby to full on are minimized.

Abstract: A laser configuration is disclosed wherein the active region is of annular cylindrical form. Zero mode azimuth coupling which produces an output beam of low obscuration ratio in the near field, thereby providing a single lobe in the far field, is achieved by the use of an unstable optical resonator characterized by an annular mirror defining one end of the resonator and a two stage axiconic reflector disposed optically between the opposite ends of the resonator.