An Overview of Digital Printing Systems - Control of Color Imaging Systems: Analysis and Design - page 10

FIGURE 1.7 Schematic side view of a TISP parallel printing system.

the iGen3 press and doubles the effective print speed to 220 images per minute to
produce 110 cut-sheet duplex pages per minute. Print engine 1 prints side 1 and print
engine 2 prints side 2, both at regular iGen3 speeds. For simplex jobs, the speed will
be 110 pages per minute, but with duplex jobs 110 pages per minute. With the
ConceptColor 220, users can achieve greater printing economics by getting twice the
speed and twice the productivity with a single operator, which saves time and labor.
By integrating two iGen3 engines in-line, it can approach a monthly print volume of
up to 7 million color pages. The ConceptColor 220 builds on the tandem architecture
technology of the Xerox Nuvera 288 Digital Perfecting System.
As increasing numbers of press systems within the print shop become parallel,
as in TIPP, TISP, or cluster printing, with similar print engines or with loosely
connected heterogeneous print engines, there will be enhanced need for distributed
optimization of interconnected work ows and outputs to ensure print quality con-

sistency. Realization of enterprise-wide optimization will require substantial pro-
gress in a number of key technical areas. They are (1) automation of the entire
publishing, production, and decision processes via feedback control using real-time
functional press models, real-time scheduling policy decisions based on sampling
the current state of the press; (2) optimization of work ow layouts; (3) the use of

sensors to measure, control, and export color to proo ng, prepress, and creation

stages and hence standardization of the color interfaces between heterogeneous press
modules; and (4) the management of sensor to sensor variabilities throughout the
press, which becomes signi

cant when distributed color optimization is required.
A single topic is not enough to cover all of the science and technology that have gone
into developing these systems. Hence, in this topic, we concentrate on the most
important imaging and control technology. These are the technologies that show
promise for making the printed images appear like offset and consistent in a single
job, job to job, and between multiple machines whether intended for use in an of ce

or an enterprise-wise production printing and publishing systems.

1.5 EVOLUTION OF CONTROLS TECHNOLOGY FOR DIGITAL
PRINTERS — COLOR CONTROLS VIEW
Xerographic printing process used for copying and printing has evolved over many
years starting from Xerox 914 era. A brief review of the history of the evolution of

controls in EP products can shed some light on why controls technology is con-
sidered important in this process. This can later help us to understand the complexity
of advances involved in designing digital production color printers.

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