Abstract: A multiple print engine configuration allows a plurality of workstations (10) to create individual print jobs and then transfer them to a distributing processor (14). The distributing processor (14) is operable to spool the jobs in a print spooler (20) and then perform a software RIP on the print jobs. The RIP process divides the jobs into multiple individual jobs which are stored in the page buffer (24). An image task manager (26) in conjunction with an engine manager (28) are then operable to selectively distribute the pages to multiple print engines (16). They are distributed in such a manner that they are placed in the output bins (40) in the order that the pages were received in the print jobs.

Abstract: A method and apparatus for routing page data of a print job to the printers in a multi-print engine based on print job parameters associated with the page data of the print job is disclosed. One or more virtual printers are configured, each with a plurality of individual print engines, each having associated printing characteristics. Page data of the print job, downloaded from a print file and having the print job parameters associated therewith, is rasterized and stored as bit-mapped images in print buffers associated with the multi-engined printing system. The bit-mapped images are distributed to select ones of the print engines based upon matching the print job parameters of each bit-mapped images with the printing characteristics of the print engine to be selected.

Abstract: The toner in the toner cartridge is determined by taking each of the rasterized images output by the RIP and evaluating the pixel levels over the surface thereof. The average value is determined as a percentage of the maximum toner that can be applied to the page. This is then subtracted from a toner value and a remaining toner level determined. Further, all pages of the rasterized document can be evaluated to predetermine the toner level after printing. If this falls below a predetermined minimum, printing is inhibited for that document.

Abstract: A method for providing color correction to a color marking engine for halftone and contone images includes the step of first generating a test pattern. This test pattern has a plurality of discrete images disposed thereon with the discrete images having characteristics that are correlated with parameters of the print job. In one mode, they relate to halftone images that have differing densities of dots, each less than 100% density. The images are correlated to different bit values for the same densities such that the maximum density value for the pixel is offset for different images. A user then views the different images and determine which one is closest to a true gray and then selects the offset bit value for that image as the marking engine offset. This can then be applied to that particular marking engine. This can be utilized for a plurality of marking engines (651) with a single RIP operation (649 and 651).

Abstract: A method for providing color correction to a color marking engine for halftone and contone images includes the step of first generating a test pattern. This test pattern has a plurality of discrete images disposed thereon with the discrete images having characteristics that are correlated with parameters of the print job. In one mode, they relate to halftone images that have differing densities of dots, each less than 100% density. The images are correlated to different bit values for the same densities such that the maximum density value for the pixel is offset for different images. A user then views the different images and determine which one is closest to a true gray and then selects the offset bit value for that image as the marking engine offset. This can then be applied to that particular marking engine. This can be utilized for a plurality of marking engines (651) with a single RIP (650).

Abstract: A method for providing color correction to a color marking engine for halftone and contone images includes the step of first generating a test pattern. This test pattern has a plurality of discrete images disposed thereon with the discrete images having characteristics that are correlated with parameters of the print job. In one mode, they relate to halftone images that have differing densities of dots, each less than 100% density. The images are correlated to different bit values for the same densities such that the maximum density value for the pixel is offset for different images. A user then views the different images and determine which one is closest to a true gray and then selects the offset bit value for that image as the marking engine offset. This can then be applied to that particular marking engine. This can be utilized for a plurality of marking engines (651) with a single RIP (650).

Abstract: A multiple print engine configuration allows a plurality of workstations (10) to create individual print jobs and then transfer them to a distributing processor (14). The distributing processor (14) is operable to spool the jobs in a print spooler (20) and then perform a software RIP on the print jobs. The RIP process divides the jobs into multiple individual jobs which are stored in the page buffer (24). An image task manager (26) in conjunction with an engine manager (28) are then operable to selectively distribute the pages to multiple print engines (16). They are distributed in such a manner that they are placed in the output bins (40) in the order that the pages were received in the print jobs.

Abstract: A print engine is provided for electrophotographically transferring an image from an image source to an image-support member. The print engine includes a photoconductive member having a photoconductive surface for storing a latent, electrostatic image. A photoconductive drum charger and an image transfer device generate the latent, electrostatic image on the photoconductive surface. A developer station supplies developer to the latent, electrostatic image as it is being carried by the photoconductive surface to provide a developed image. A carrier member includes an electrically charged support surface for supporting an image-support member which is passed through an image transfer nip. The image transfer nip extends between the photoconductive member and the carrier member. The image-support member and the developed image are simultaneously passed through the image transfer nip so that the developed image is transferred to the image-support member.

Abstract: A dual mode electrophotographic print engine. A voltage controller (25) provides operating voltage to a scorotron (27), which applies a charge to a photoreceptive medium. In a first mode a screen (40) is placed in a first position, out of the optical path between the image focusing device and the photoreceptive medium (45). This produces full exposure of the photoreceptive medium (45) to the focused image. This produces a latent image on the photoreceptive medium. Toner is then applied to the latent image to produce a developed image. In the second mode of operation, for producing half-tone copies, the screen (40) is inserted into the optical path. This reduces the exposure of the photoreceptive medium (45). To compensate for the reduced exposure the voltage controller (25) provides a second, lower voltage to the scorotron. This lower voltage compensates for the reduced exposure time so as to produce a high quality latent image. Toner is then applied to the latent image to produce a developed image.

Abstract: A belt conditioning system for a flexible belt electrophotographic print engine includes a cleaning blade (144) which is operable to clean a transfer belt (20) on a per page basis. A roller (152) is operable to be disposed in contact with the belt (20) on a page intermittent basis to more aggressively condition the belt (20). A controller (39) is operable to activate the roller (152) on a page intermittent basis and, during activation of the roller (152), transfer of images to the transfer belt (20) from a PC belt (30) is inhibited to prevent any registration problems from occurring during the conditioning cycle.

Abstract: A transfer mechanism for a full color double transfer electrophotographic print engine. Relatively conductive developer materials having successively increasing triboelectric charge characteristics are used to develop sequential images. Conductive plates displaced away from the transfer station along the direction of travel of the transfer belt are used as one electrode for applying an electrostatic field at each transfer station. A parameter of the transfer mechanism is a bulk resistivity of the transfer belt in the range of 10.sup.7 to 10.sup.10 ohm-centimeters and a surface resistivity for the belt in the range of 10.sup.7 to 10.sup.10 ohms per square. A selectively operable compression roller, compressing paper and transfer belt against a rubberized idling roller at one of the transfer stations increase dwell time in the transfer station. The compression roller automatically falls to a cleaning station where it is rotated by another rotary member to clean it between transfers.

Abstract: An improved color correction apparatus for improved color printing in a subtractive color printing system is disclosed. The disclosed apparatus utilizes an optimized three-dimensional look up table of pigment density values addressed by primary color values. The look up table is created by printing a plurality of pigment bars in response to known input density signals to a laser beam for each of three color pigments used in the system. Each of these sets of bars is subsequently scanned by the input scanner to determine the spectral content of the resultant bars and thus create a plurality of color pigment values corresponding to the spectral content of each bar for each color which is a complementary color of one of the pigments. These characteristics are used to calculate the spectral content of an actual printed image generated in response to an image generated by an input triplet to the system.

Abstract: Improved dual belt synchronization for a print engine for color electrophotography using a photoreceptor belt and a seamless transfer belt on which a composite image is built up. Improved synchronization of the two belt drives enhances image registration. A tension mechanism used in conjunction with the belts prevents rapid changes in the belt dimensions. An improved transfer belt cleaner system is synchronized with the belt drives such that excess toner is not left in the imaging area of the transfer belt.