Abstract: A punch assembly is provided with a positive retraction mechanism to remove the punch from the media to be punched, thereby preventing binding of the punch in the media. The punch assembly includes a driving mechanism to provide a driving force on the punch and a positive retraction mechanism disposed to provide a retraction force on the punch operative sequentially following operation of the driving mechanism. The punch assembly, which is of a smaller size and more economical to manufacture, is particularly useful with an imagesetter of a prepress printing system. The punch may be mounted in a cantilever manner to punch the opening as close to the edge of the media as possible without interfering with the laser beam of the imaging assembly. In this maimer, the area of media available for imaging may be maximized and media waste minimized. Additionally, a shaft support mechanism is provided for the shaft upon which the retraction mechanism for each punch is mounted.

Abstract: In one aspect, the invention features a system and method for displaying an image on an output device. The method includes creating an image having one or more separations with an imaging application thereby forming a description of the image in a page description language. The method includes processing the description of the image in the page description language thereby creating a raster for each color separation associated with the image. The method also includes selecting a subset of the rasters for proofing. The method includes creating a second page description language file including each of the selected subset of the rasters for proofing and imaging the second page description language file with an output device. The system includes a raster image processor for processing the description of the image in the page description language thereby creating a raster for each color separation associated with the image.

Abstract: The present invention provides an extruded external drum for an imaging system. The external drum is extruded from a light-weight and strong material such as an aluminum alloy. The external drum includes a thin outer wall, a hollow cylindrical hub, and a plurality of thin radial spokes extending between the cylindrical hub and the outer wall. The present invention provides a stiff external drum having low rotational inertia.

Abstract: A system and method for transferring and buffering sheets of media between first and second components of an imagesetting system operates by: rotating a transfer buffer having at least two storage devices, to align a first storage device with the first component while concurrently aligning a second storage device with the second component; transferring a first sheet of said media from the first component to the first storage device; rotating the transfer buffer to align the first storage device with the second component while concurrently aligning the second storage device with the first component; and transferring the first sheet of said media from the first storage device to the second component while simultaneously transferring a second sheet of said media from the first component to the second storage device.

Abstract: A media supply cassette is disclosed for use in an imaging system for processing a web of imageable media. The media supply cassette includes a first roller and a second roller for providing a nip through which the media exits the supply cassette through rotation of the first roller. The supply cassette also includes a third roller coupled to the first roller such that rotation of the third roller causes the first roller to rotate. The third roller is positioned to contact a fourth roller in the imaging system such that rotation of the fourth roller causes the third roller to rotate thereby providing rotation of the first roller which causes the media to exit the cassette and enter the imaging system.

Abstract: A method for transferring an image to a medium includes: generating a substantially uniform line of radiation; producing diffractive light from the uniform line of radiation; passing zero order diffractive light to the medium in a telecentric fashion while blocking non-zero order diffractive light; adjusting image magnification on the medium independent of image focus in response to the zero order diffractive light; and adjusting image focus on the medium independent of image magnification in response to the zero order magnification-adjusted diffractive light.

Abstract: An autofocus process for imaging optics of a scanner comprises performing multiple scan-line image captures of the document to be scanned. In the preferred embodiment, these captures are of essentially the same scan-line. A focal position of imaging optics, which forms a scan-line image, is adjusted relative to an image detector in between the multiple scan-line captures of image data. In the preferred embodiment, the imaging optics is adjusted. Relay optics or a position of the image detector could alternatively be adjusted. In any case, a focus setting for a subsequent scanning operation is then calculated based on the image data from the multiple scan-line captures. In the preferred embodiment, this calculation yields a lens position for the imaging optics. The invention thus allows autofocussing to the document to be scanned. Problems associated with loss of calibration are avoided. Moreover, the system is able to adapt to documents where the image is not at the scanner's nominal focal plane.

Abstract: A recording media for phase change ink recording comprising: a support; 30-200 mg/dm2 of a receptive layer coated on the support wherein the receptive layer comprises: a binder comprising: a water soluble polymer; and a water insoluble polymer; wherein the combined weight of the water soluble polymer and the water insoluble polymer comprises at least 50%, by weight, and no more than 95%, by weight, water insoluble binder; and an optional inorganic particulate material. The media has an island size of no more than 15 &mgr;m and an asperity of 5.0 to 6.2 &mgr;m which is formed by controlling the drying rate.

Abstract: A method and apparatus for collecting and removing chaff from an internal drum imaging system. The chaff collection apparatus includes a chaff tray coupled to the internal drum below the side punches. The chaff tray includes a cover comprising a plurality of evenly spaced frangible fingers. A specific set of the fingers is removed from the cover according to the locations of the side punches on the internal drum. In this manner, only the portions of the cover below the side punches are open to the interior of the chaff tray. The chaff produced by each punch passes into the chaff tray through a respective opening in the cover, and is captured within the chaff tray. The areas of the cover of the chaff tray that are not located below the side punches remain covered by the remaining frangible fingers, thereby preventing chaff from escaping the chaff tray.

Abstract: A flat-bed scanner for scanning an original document, comprising a scanner housing and a scan carriage movably disposed for motion relative to the scanner housing. A sensing system is mounted to the scan carriage for scanning the original document. A media holder supports the original document for scanning along a scan line such that the original document is positioned at an object focal plane of the sensing system. The media holder support system dynamically maintains a portion of the original document proximate to the scan line coincident with the object focal plane during scanning. The support system includes a first mounting device pivotally attaching a first end of the media holder to the housing for allowing a pivot motion of the media holder with respect to the scanner housing and a second and a third mounting device are affixed and movable with the scan carriage for movably supporting the media holder during the motion of the carriage.

Abstract: Methods and apparatus for rapidly removing stored energy from (i.e., erasing) a reusable photostimulable storage phosphor screen use a first source of electromagnetic radiation which primarily outputs a wavelength or wavelengths of about 577 nanometers to about 597 nanometers, and a second source of electromagnetic radiation which primarily outputs a wavelength or wavelengths in the infrared region. Exposure to the second source of radiation may occur either after, or simultaneously with, exposure to the first source of radiation. During exposure to the first source of electromagnetic energy, ultraviolet radiation is filtered out so that none reaches the phosphor screen, or a first source is selected which does not output substantially any ultraviolet radiation. The first source of electromagnetic radiation erases the phosphor screen to a homogenized quasi-erased state.

Abstract: A vacuum system can remove ablated particles from an internal drum platesetter which has a drum for supporting a photosensitive medium, a carriage moveable in a direction parallel to a longitudinal axis of the drum, and a laser mounted onto the moveable carriage for generating a beam to create an image on the medium during movement of the carriage, the beam ablating particles of the medium during creation of the image. The vacuum system includes: a vacuum head fixedly attached to the moveable carriage, and having at least one chamber for receiving the ablated particles through a slot located proximate to a periphery of the vacuum head; and an exhaust system connected to the vacuum head and including ductwork, at least one fan and at least one filter, for extracting the ablated particles from the at least one chamber of the vacuum head.

Abstract: An imagesetting or platesetting system and method for transporting one or more sheets of media having varying stiffness and thickness includes the steps of: transporting the sheets through the system in a first direction (A); recording an image onto the sheets; and redirecting one or more of the sheets in a transverse direction (B) relative to the first direction (A). Preferably, this is accomplished using: a transport mechanism for transporting the sheets of media through the system in the first direction (A); an imager for recording the image onto the sheets; and a jogging mechanism for redirecting the sheets in the transverse direction (B). The jogging mechanism can be integrated or modular to the system. Moreover, the jogging mechanism can be used in both internal and external drum imagers.

Abstract: Image processing parameters for gradation correction of a digital image from a scene, which includes specular reflections may be seriously influenced by the presence of those specular reflections. Therefore, a method is developed to detect the presence of specular reflections in a scene, to modify the exposure time of the photo-sensitive means, which converts a luminous image to electronic image signals and to apply a gradation correction to the image data thus acquired. In one embodiment a digital camera is used to capture the image data, a cumulative histogram is built and two characteristic cumulative frequencies are used to determine via the histogram specular densities and highlight densities. The relative position of these density values indicates whether specular reflections are present, and give suitable parameters for setting an optimal exposure time and for computing a gradation correction curve.

Abstract: A laser beam intensity modulation system has a variable delay circuit that is used to control the relative delay in the delivery of a video signal between two cascaded AOM's. This delay circuit is controlled by a delay controller that monitors the intensity modulation of the laser beam to provide feedback control. This system maximizes the rise and fall times of the beam to generate precise beam modulation required for high speed image setters.

Abstract: An apparatus (11) for conditioning media, for example a moving web (12) of receptor material in an electrostatographic printer (10), is described. The apparatus (11) comprises a heating system, such as a heated drum (55), to adjust the moisture content of the media and a cooling system (65) for cooling the heated media. A moisture sensor such as an electrometer (74) determines the moisture content e.g. by an electrical condition of the media before it leaves the apparatus (11). The moisture sensor (74) controls the heating system (55). A temperature sensor (81) determines the temperature of the media after cooling. This sensor (81) may control the cooling system (65) or other parameters of the system. By conditioning a receptor material in an electrostatographic printer, a higher yield of toner transfer can be obtained. Optionally two electrometers (74a, 74b) are used to thereby detect the charge decay on an earthed metal drum (72).

Abstract: A font compression method and apparatus operates by: compressing different components of a font file with separate compressors having varying compression schemes to produce a plurality of intermediate compressed data sets; separating compressed glyph table components of the font file into different ones of the intermediate compressed data sets; and further compressing the intermediate compressed data sets to produce corresponding compressed output data sets. A corresponding decompression method and apparatus is used to decompress fonts which have been compressed using the above method.

Abstract: An imagesetting system includes: an imagesetter for photographically recording an image onto media; a wet chemical processor, proximately positioned adjacent to the imagesetter, for receiving and processing the imaged media, and a light-tight control wedge box containing a test strip to be processed by the wet chemical processor, without physically separating the imagesetter and the processor, to indicate whether chemicals in the wet chemical processor are depleted below a level of effectiveness. The imagesetting system operates in a test mode to determine whether chemicals in the processor are depleted below the level of effectiveness.

Abstract: A system and method for calibrating a printer includes the steps or functions of: printing a predetermined color test pattern with the printer by transforming data, representing said predetermined color test pattern, from a device-independent color space to a device-dependent color space associated with the printer by use of a color transform, said predetermined color test pattern including a set of color patches with one of said color patches representing a preferred mid-gray hue; providing a predetermined reference gray surface; comparing said reference gray surface to said set of colored patches of the printed test pattern to find a closest matching one of said patches, if the closest matching one of said patches is the patch representing the preferred mid-gray hue, then ending the method; otherwise determining, for each color channel of the printer, a solution set of correction values as a function of believed gray versus actual gray, said solution set derived from and including a white point, a black poi

Abstract: A laser diode driver system automatically tracks the difference between the steady state operating point of a feedback signal in response to a laser diode driver circuit operation and the steady state operating point of the same feedback signal in response to a dummy driver circuit operation. That difference is used to compensate the dummy driver circuit operation such that its operating point correlates with the laser diode driver circuit operation. Further, in accordance with a second aspect of the present invention, a laser diode driver system automatically tracks the difference between the steady state operating point of a feedback signal in response to the quiescent laser diode driver circuit operation and the steady state operating point of the same feedback signal in response to the output of a high frequency oscillator. That difference is used to adjust a variable current source such that a dummy driver circuit is not disabled until the laser diode turn-on time delay has expired.