Xerox 721P87491 manual Printer imaging characteristics

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To preserve image quality when printing on 300 dpi printers, regenerate the bitmaps at 300 dpi. The 600 dpi printers can accept jobs with resources in either 300 or 600 dpi. See “Maintaining image quality” in the “PCL5e” chapter for information about the recommended attribute settings to use when generating a document on your system.

Some manufacturers have added hardware imaging enhancements to 300 by 300 dpi printers that effectively boost the apparent dpi by micro-controlling the laser beam. The function is called post- enhancement because it is performed by the hardware after the PostScript interpreter has imaged into the frame buffer. The frame buffer is still only 300 by 300 dpi, but the hardware is controlling the laser beam to produce smoother edges.

Other manufacturers have added pre-enhancements that involve the PostScript interpreter. In these printers, the frame buffer is actually larger because the PostScript interpreter is effectively rendering at a higher resolution. The hardware performs some of the halftoning function to provide finer halftoning, resulting in picture output that looks smoother.

You can only accurately compare two different printers if both are using the same enhancement techniques or if all enhancement techniques are turned off.

Printer imaging characteristics

Most xerographic printers do not image perfect circular dots with even dry ink distribution. The dry ink “spread” is typically Gaussian, with dry ink density being the greatest at the center of the dot and fading off toward the edges.

The terms “write-white” and “write-black” are broad generalizations. The specific print imaging characteristics of some products may not represent other products with the same write-white or write-black classification. For example, the HewlettPackard (HP) LaserJet and the LaserWriter II NTX use a write-black laser printer engine that uses the laser beam to “write” where dry ink should go. Therefore, single pixel dry ink dots are approximately round and are visible on an HP LaserJet. In contrast, write-white laser printer engines “write” the dry ink free areas, which can create single dots that have four concave sides.

It is important to distinguish the fast scan direction, which is the direction the laser beam moves across the page before jumping back to do the next line. Remember that a laser printer scans a page in a raster method, just like a television set. Fast scan directions are not the same for a LaserWriter and the Xerox engine.

In general, when turning on the same pixels, the write-white engine produces output that appears lighter than output produced by a write- black engine. Xerox device-parameterized PostScript interpreters are able to partially compensate for this by rendering thicker strokes and fonts. Device-dependent PostScript cannot be compensated for because it is sending user-created bit images instead of mathematical descriptions of the desired output.

•User-defined PostScript fonts—Some user-defined fonts use bitmaps that are tuned to write-black engines. These fonts appear light on certain write-white printers.

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XEROX DOCUPRINT NPS GUIDE TO USING PAGE DESCRIPTION LANGUAGES

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Contents Version 7.1 August 2000 721P87491 Page Ozone information Laser safetyOperation safety Conductor may result in risk of electrical shock. grounding Table of contents PostScript Vipp IndexViii Conventions ContentsAbout this guide Introduction PostScript publications Related publicationsRelated information HP PCL 5 publications Vipp publicationPCL Maintaining image qualityOFF PCL 5 media support PCL 5 font supportPCL 5 fonts installed with NPS software PCL Copy command PCL command supportPJL commands PCL Copy command example Duplex PCL Copy command examplePCL Duplex commands PCL Duplex commands DocuPrint NPS Collated HP LaserJet 4siPCL Job Separation command PCL Paper Source command tray assignment PCL media selectionPrecedence in selecting media PCL Output Bin command PCL Offset Registration commandsPCL 5c support PCL 5 coding recommendationsPCL 5c coding recommendations PCL 5c functions not applicable to DocuPrint NPSDriver recommendations for PCL 5c Limitations for custom PCL 5c driversFloating-point arithmetic and math operators Coordinate system default matrixImplementation-dependent operations Font Typeface FontsAdobe Type1 PostScript fonts Loading fonts User-defined fontsUsing Adobe Type 1 fonts Type 1 fontsUsing a Type 1 font in a document Producing Type 1 fonts for use with DocuPrintSystem Dict PostScript with embedded PJL commandsPostScript language extensions User Dict Server DictDfltkIdleArry needflush Status DictIdleTime Dictionary Nonstandard definitions Examples of nonstandard definitions Printer resolution and resolution enhancementAppearance consistency Statusdict UserdictDpi image Printed on a 300 dpi printer Printer imaging characteristics Font consistency Proprietary PostScript extensionsControl-Z and superfluous errors Control-D as binary data and end-of-jobSolution to control-Z and control-D problems Multiple jobs in one input file DocuPrint NPS implementation of PostScript Level Simulated mixed plexStroke Printer Controller operationsScan conversion details Fill ShapesImages Zero-width lines strokesCurved shapes Image quality Rendering of color and gray values transfer function PostScript printer description PPD files Implementation limitsQuantity Limit Description File operators and standard devicesImplementation limits SetCacheDevice Path limitsPostScript VM limits Device orientation and setscreen operatorArc to Bezier conversion-pathforall PostScript storage object size limitsObsolete operators-banddevice, framedevice, renderbands Scan order and rotation Creating the necessary PostScript Ccitt Group 3Print performance related to image printing Purpose Image orientation mismatch aImage orientation mismatch B 10.Image pixel sequence example Considerations SummaryScan resolution and scaling 11.Scaling and resolution example12.PostScript with embedded image normal scan order MaxX exch def /minY exch def /minX exch def 14.Actual PostScript print Page Vipp Functionality Operating environmentVipp line mode extension XGFNub Page Symbols CcittIndex PCL PPD Index

721P87491 specifications

The Xerox 721P87491 is a remarkable printing device that showcases advanced technology tailored for professional environments, ensuring high-quality output and efficiency. Aimed at meeting the demands of busy offices, this model is recognized for its reliability and innovative features.

At the core of the Xerox 721P87491's appeal is its robust printing capabilities. It offers an impressive resolution, enabling the production of crisp and clear documents, whether in black and white or color. This high-resolution output is particularly essential for businesses that require detailed graphics, intricate charts, or professional-grade presentations.

One of the standout features of the Xerox 721P87491 is its impressive speed. It is designed to handle high-volume printing, significantly enhancing productivity in fast-paced work environments. With a rapid print speed per minute, users can expect swift processing of print jobs, ensuring that document delivery times are minimized.

The device also boasts advanced connectivity options. It supports both wired and wireless connections, allowing for seamless integration into a variety of office networks. This flexibility facilitates printing from multiple devices, including desktop computers, laptops, and mobile devices, enhancing overall workflow and collaboration within teams.

Additionally, the Xerox 721P87491 incorporates user-friendly interface options. With an intuitive touchscreen display, navigating the printer's functions becomes simpler. Users can easily access common features, adjust settings, and manage print jobs efficiently.

Another notable characteristic is its advanced security features. Given today's emphasis on data protection, the Xerox 721P87491 is equipped with robust security protocols to safeguard sensitive documents. It includes features like secure print, which holds documents until the authorized user enters a PIN, ensuring confidentiality in high-stakes environments.

Moreover, the Xerox 721P87491 demonstrates an emphasis on environmental sustainability. It is designed to be energy efficient, reducing power consumption during both idle and active states. The printer also supports duplex printing, which helps decrease paper use, contributing to a more sustainable office practice.

In summary, the Xerox 721P87491 is a versatile printing solution that merges efficiency, quality, and advanced technology. With high-speed printing, intuitive controls, robust security features, and a commitment to sustainability, it stands out as an excellent choice for businesses aiming to boost productivity while maintaining high standards. Its capabilities make it a worthy investment for any modern office environment.
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