How Do Digital Copiers Work?

Benefits

Digital copiers replaced analog copiers as the standard in office equipment. This is because they are not only environmentally safer, but they are also far easier to maintain and repair. Digital copiers essentially perform the same duties as a document scanner and a laser printer. Digital copiers not only recreate images, but they can enhance those images as well. Sometimes duplicates are far superior in quality than the originals because the saturation and intensity in the original documents can be enhanced.

Function

Digital copiers function in two ways. Using both a positively charged drum and a negatively charged toner, any type of copier is able to copy images from an original source onto a new sheet of paper. A digital copier, however, has the added feature of scanning documents into its computer system. The computer stores files of the scanned documents from which these documents can be saved, reprinted or altered.

Scanning Technology

The scanning is done in three processes. The copier scans or memorizes the original document through a system called the raster image processor. After the raster image processor memorizes the document, a laser prints the image onto a sheet of paper using lenses and mirrors. After the toner is struck by the laser, it makes the image more visible on the paper.

The raster is basically a process in which vector digital images (such as a PostScript file) are turned into raster images with high resolutions. This is done in three stages: interpretation, rendering and screening. During the interpretation stage, PDLs (Page Description Languages) are given private internal translations and representations for each page. After this is done, these representations are then rendered into something called a continuous-tone bitmap. The continuous-tone bitmaps are then changed into halftones, which are basically a pattern of dots that are then screened onto the page to form the images.

Resources

• How Do Digital Copiers Work?
• Raster Image Processor