How Does a Plotter Printer Work?
Computer plotters are a type of output device commonly used for computer-aided design applications, to output large vector designs such as architectural blueprints. By moving a pen mechanically, plotters draw line art onto the surface of the paper to reproduce vector graphics drawn on a computer. Although ideal for printing large line art graphics, plotters could not reproduce raster graphics, and the introduction of wide format inkjet and laser printers have rendered them largely obsolete.
There are two main types of plotters for printing: flatbed plotters and drum plotters. Flatbed plotters use a system where the paper is fixed, and the plotter moves a pen up and down, and left and right to draw the required marks on the paper. Drum plotters move the pen up and down, and the paper left and right by rotating the drum. This enables drum plotters to have a footprint smaller than the final paper size. Plotters can use more than one pen, allowing different colors to be drawn.
Plotters work in conjunction with CAD software on the computer, to output line drawings for plans, blueprints and other technical drawings. Due to the mechanical actions involved in moving the pen, compared to other types of printers such as ink jet and laser printers, early plotters were slow to produce their output. Only a small number of pen plotters are still in use commercially, with many refurbished models available at low prices in online auctions.
Another type of plotter is the cutting plotter, which replaces the pen with a sharp blade. This allows the plotter to cut vinyl and other thin materials to produce graphics for signs, vehicles and advertising. Smaller cutting plotters that can fit on a desktop are available for the home market, for crafts and other hobbyist applications. Although cutting plotters are still widely used, laser cutters are starting to replace them as units fall in price, which are faster and can cut through a wider range of materials.
Pen plotters, with their slow speeds and complex mechanisms became redundant with the advances in printing technologies. Inkjet technology was the ideal replacement, with a small self-contained print head that moves across the paper, allowing manufacturers to produce wide format plotters that can print on large paper sizes. Microchip and memory advances enable plotters to perform more processing onboard, allowing for faster printing at high resolutions, with high levels of accuracy. Unlike pen plotters that can only print line art, one big advantage with inkjet technology is the ability to print photo quality graphics, increasing the versatility of the plotter.