Analog copiers constitute a dwindling percentage of the business equipment sold and in service. Especially at the high end of the performance scale, digital copiers offer workgroup-class reliability and speed coupled with convenient output features. The fundamental difference between these two categories of machine lies in their reliance on mechanical or computerized output processes. The implications of that difference affect far more than the quality of the copies you can make on either type of equipment.
Color or monochrome, an analog copier uses a system of lights, lenses and mirrors to recreate source material, transferring a page image onto the photosensitive belt or drum that applies toner onto blank paper for heat-fused output. As the name of the equipment category points out, the entire process remains reliant on optical components and processes. By contrast, digital copiers rely on embedded computers to transform originals into pixel-based images, the same way a desktop scanner digitizes a document and holds that scan in memory. Although most copiers -- analog or digital -- use toner-based printing processes, some relatively inexpensive desktop multifunction devices use inkjet rather than laser printing to create their output.
The fidelity with which a copier recreates a source material image depends on the precision of its optical components or the resolution of its digital equipment. A good analog copier can produce crisp output throughout a range of reduction or enlargement percentages from half scale to double original size, although as the percentages rise, the fidelity of the output may drop. Because digital copiers use pixel-based scanning equipment to acquire original documents, the resolution of their hardware determines both the precision of their output and the clarity of their enlargements. A copier that scans at 600 dots per inch halves that resolution to create a 200 percent enlargement.
By definition, analog copiers can't retain the material they process. They contain no equipment capable of storing a page image for further output or manipulation. Digital copiers leverage the nature of their output processes to add numerous capabilities, including hard drive storage of often-reproduced pages, fax and email transmission of copied material, networkable operation as printing devices, and even editing features that can insert new material onto digitized sources. For example, a digital copier can store the image of a sheet of letterhead and automatically combine it with the text of a correspondence or a presentation.
The reproduce-and-forget performance of analog copiers helps reduce their ability to create security risks. Although either an analog or a digital copier can duplicate personally identifiable information, copyrighted or proprietary material in violation of the law or as an intrusion into company secrets. Only a digital device holds on to content after it transfers originals to outgoing sheets of paper. A would-be data thief can access a digital copier's hard drive and obtain sensitive documents from its contents, or harvest the residual data on the drive inside a discarded piece of equipment. As a result, digital copiers raise privacy issues and security concerns that don't apply to analog copiers.