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Unformatted text preview: d graphic output on large sheets. The various types of
printers discussed above are, not suitable for meeting this output requirement of such
applications. A special type of output device called plotters is used for this purpose.
Plotters are an ideal output device for architects, engineers, city planners, and others who
need to routinely generate high-precision, hard-copy graphic output of widely varying
The two commonly used types of plotters are drum plotter and flatbed plotter. They are
briefly described below.
In a drum plotter, the paper on which the design has to be made is placed over a drum
that can rotate in both clockwise and anti-clockwise directions to produce vertical
motion. The mechanism also consists of one or more pen holders mounted perpendicular
to the drum's surface. The pen(s) clamped in the holder(s) can move left to right or right
to left to produce horizontal motion. The movements of the drum and the pen(s) are
controlled by the graph plotting program. That is, under computer control, the drurn and
the pen(s) move simultaneously to draw the designs and graphs on the sheet placed on the
drum. The plotter can also annotate the designs and graphs so drawn by using the pen to
draw characters of various sizes. Since each pen is program selectable, pens having ink of
different colors can be mounted in different holders to produce multi-colored designs. A
drum plotter is shown in Figure 9.34. Flatbed Plotter
A flatbed plotter plots a design or graph on a sheet of paper that is spread and fixed over
a rectangular flatbed table. In this type of plotter, normally the paper does not move and
the pen holding mechanism is designed to provide all types of motions necessary to draw
complex designs and graphs. That is, under computer control, the pen(s) move in the
required manner to draw the designs and graphs on the sheet placed on the flatbed table.
The plotter can also annotate the designs and graphs so drawn by using the pen to draw
characters of various sizes. Here also provision is there to mount mor...
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This document was uploaded on 04/07/2014.
- Spring '14