Plotters
Many people think that the words plotter and printer can be used interchangeably, but a plotter and a printer are two different things. A plotter is a printing device, but it works in a much different way than a typical printer. Essentially there are two types of plotters, pen plotters and electrostatic plotters.
A pen plotter is a device that uses a pen attached to a mechanical arm to create printed material. The mechanical arm holds the pen, and moves across the paper to create the desired image. Because of this, pen plotters may only produce line art as opposed to raster graphics. Raster graphics are images composed of pixels and must be printed by other types of printing devices. The pen plotter can, however, create very intricate pieces of line art, although the pen plotter does work very slowly because of the nature of the mechanical arm device. It is difficult for a pen plotter to create a large area of solid color, but they can come close by using a back and forth motion to fill in a large area with color. If you think of the motion of scribbling back and forth, this would be somewhat similar to how a pen plotter would fill in a large area with color.
These days, a pen plotter is controlled by a computer program that tells the mechanical arm what to do, or in other words what to draw. Pen plotters may be programmed using various programming languages such as Hewlett-Packard’s HPGL2 or Houston Instruments DMPL. Pen plotters are generally used with wide format output paper, so the line image produced is usually printed on some type of large format plotter paper roll.
Surprisingly pen plotters have been in existence since the year 1959 and used rudimentary technology such as ball point pens. The plotter machines of this era were very large and very slow. The pen plotter technology improved in the 1970’s and 1980’s with smaller and faster models being produced by various technology companies. Pen plotters have all but disappeared today as most people and businesses use the more common printing technology for all of their printing and imaging needs.
Pen plotters are mainly used these days in the technical drawing and computer aided design (CAD) industries. The large format plotter paper rolls that the pen plotter is able to print on is the main draw or the technical drawing and computer aided design industries to continue to make use of the pen plotter.
The electrostatic plotter is a type of plotter that uses electrostatic printing methods. This means that a positively charged toner is used as the ink in this type of plotter. The positively charged toner is attracted to the paper which is negatively charged. The paper is negatively charged by means of a line of electrodes and these electrode lines are maneuvered in a manner that produces the desired image. Electrostatic plotters also use large format plotter paper rolls and are good for printing large images such as technical drawings and floorplans.