Black and White Photocopiers
Traditional photocopiers are otherwise known as analogue copiers, which are very different to digital copiers now more commonly in use. Initially, analogue copiers were limited to monochromatic (black and white) copy of a single sheet using certain photoelectric, electrostatic and electrochemical methods.
The common method of creating a copy is by shining a light through the original document which then generates static electricity between a rotating drum and a powdery chemical called ‘toner’ that releases the ink. To understand more about how traditional copiers work, click here.
The ink from the toner in a traditional copier is of a single dark colour, producing the black and white effect on the photo copy. To make multiple copies of an original sheet, the processes inside the machine need to be repeated over the original document. This makes the system slow for large volume photocopying and replacing the toner very costly. The drum also needs to be replaced periodically, though not as frequently as the toner, but this is also very expensive.
Colour Photocopiers
Traditional colour copiers require ink that can replicate the placement of colours on the original document. Although colour toner was available quite early, the basic mechanism of photocopying in analogue copiers was too simplistic to make sense of colour. Therefore, the original colour copiers used a process called Dye Sublimation.
Eventually, a mechanism to detect colour using light allowed electrostatic technology and colour toners to be used for colour copiers just like black and white copiers.
Functionality and Availability
The electrostatic mechanism in analogue copiers only allows a copy to be made at the same scale as the original document. This means, for example, that an A4 document will only produce a copy of the same paper size.
Traditional copiers, whether black and white or in colour, can still be purchased but are less available. As a result, not only is it difficult to find supply of consumables such as toner and the drum and thus also costly; but the operating costs to replace the toner, drum and any other moving parts prone to breakage can be expensive.
Disposing of old toner can be an environmental headache, but there are means available to recycle old toner units.