Plotter

A plotter (of English. Plot = draw ), referred to in German as a plotter is an output device that represents function graphs, technical drawings and other vector graphics on various materials. They are among the few devices that reflect directly Illustrations, without converting them before in a raster graphics. Their predecessors were the XY recorder used in metrology. Since the 1990s, plotters were in most areas replaced with large-format printer, but which are still referred to predominantly as Plotters.

Pen plotter

The pen plotter is for representations on paper, usually A3 to A0, is designed. He uses an ink pen which is mounted on a trolley. This carriage slides on a rail which may be moved either over the entire paper width ( flat bed ), but is fixed or mounted while the paper is moved over a roll ( roll cutters ). Most plotter work with ink pens of different line widths, which are housed in a magazine and are automatically installed when required to the car. Both mechanisms allow for fast display of vector graphics such as simple lines and circles as well, however, quite unadorned lettering.

Pen plotters found only rarely used. They have been replaced by laser or inkjet appropriate size that convert vector graphic into a raster graphic before printing.

Some pen plotter can be converted into a cutter.

Cutting plotter

The cutter plotter is a plotter, in which a knife is used instead of the pins. The contours of vector graphics are cut into a label sheet without damaging the backing paper. There are primarily two kinds of devices with different concepts of the cutting head: drag knife and tangential. In a drag knife, the cutting tip is not in the axis center. To the desired contour plots then the knife will be pulled along ( towed ), or the cutter head is lowered and the film is moved. The control of the plotter now has to ensure a clean cut result, take into account the offset of the knife tip at the Plotbahnberechnung with. The advantage of drag-knife technique is the simpler design of the cutting head and the lower unit prices associated, as well as in the higher plotting speed, as the blade does not have to be raised at acute angles. Cutting plotter with tangential controlled diameters have a much more elaborate cutting head. A separate motor carries the knife in each curve with the corresponding angle. In acute angles the blade is lifted, rotated and set down again. While this takes only a few tenths of a second, but in the sum is extended by the Plotzeit. The great advantage of Tangentialmessers lies in diverse fields. The blades allow more leeway in terms of cutting edge geometry, so that stronger and thicker materials can be processed much more accurately than is the case with drag knives.

However, here is another effect come into play, which drag-knife technique plays no role in plotters: the running accuracy. Objects are often calculated by plotting software so that the film must be moved as little as possible in front and back. The film is not as exact transport ( slippage ), as is the case with the cutting head. As a consequence, are often subject forms " cut ", run (especially with a series repetition of the same subject ) and not as a cut. Since Tangentialplotter anyway to lift the blade at an acute angle, the control software optimizes mostly right here in the film transport. At the later return to the cut line of the touchdown point can often not be met optimally again.

Cutting plotters are used to depict logos or lettering. After manual removal of the excess foil parts ( weeding ) these logos or fonts can be applied to the flexible foil on other items.

With a cutting plotters pen holder can be used in a rule also, so that this can be used as single-color pen plotter.

Cutting plotter especially for the field of outdoor advertising ( vehicle graphics, advertising signs labeling, etc. ) are used.

Laser plotter

The laser plotter is an extension of the cutting plotter. The diameter of the cutting plotter is replaced by an optical system, which directs a laser beam onto the material to be processed. The laser beam itself is generally produced on the back of the device. Advantage of the laser cutter is that the interface is free of load carried out for the material, and thus very fine contours can be cut. In addition, the laser plotter allows the laser engraving of materials such as wood, leather or anodized aluminum. The advantage of laser engraving is the permanence and durability. CO2 lasers typically used in these systems, with some versions of YAG lasers are available.

Photoplotter

The Photoplotter, even light warning device includes a light head, is drawn using the on film. They are designed as a flatbed or as Trommelplotter. After developing the film can be used as a template. An application example is the production of circuit boards, which is the most common use area of ​​photoplotter.

When Trommelplotter the film is on a rotating roller, the drum is fixed, while it rests on a flat surface at the flat bed plotter.

Operation and application of HP -GL and HP -GL / 2

A plotter is controlled mostly by special CAD software. To control the plotter initially developed by Hewlett Packard printer language HP -GL has prevailed in other manufacturers. Today, modern appliances HP-GL / 2 is used as a development of the HP-GL. An important innovation here is the ability to set line thicknesses (and other line attributes ) by the software. Since HP -GL is designed for pen plotters, there was no commands to the weights to define, for these were determined by the pins. The user had to assemble according to his wishes, the pen carousel.

Although it was not designed to be HP- GL developed because of its simplicity for data exchange format for vector graphics. Most CAD programs allow you to export in HP-GL format. The import of HP -GL files as graphics is possible in OpenOffice.org.

Other variants

For some years there are also plotters, which are constructed according to the principle of the laser printer, but mostly use LED technology and are therefore also called LED plotter. Pioneer of this technology, which currently allows print speeds of up to 15 meters per minute (monochrome), in addition to the inventor Xerox company primarily the company Océ and KIP. Recently introduced KIP before the first large-format color plotter on LED technology.