Almost every office is centred around a photocopier, and this will be the case even in supposed paper-free offices for as long as the office as we know it exists.
Businesses rely on a well-maintained copier that is reliable, long-lasting, easy to use, full of useful features and capable of meeting the printing, faxing, scanning and duplication needs of a business by itself.
Whilst modern photocopiers operate as multi-function printers and take a smartphone-like approach of combining as many different devices into one unit as possible, the underlying technology at the centre of the vast majority of business copiers has remained the same for half a century.
Here is an explanation of xerography, how it works and why it became the standard for offices, schools, libraries and professional use.
What Is Xerography?
Also known as laser printing or laser photocopying, xerography (Greek for “dry writing”) is a process that uses a carefully controlled electrostatic process to attract toner particles onto an application surface before transferring and fusing them to a piece of paper.
Whilst there are variations to the process, the general principle of xerographic copying and printing tends to follow these seven steps:
- Charging the copying drum to ensure that toner is attracted or repelled as required.
- Creating an exposure by passing the document to be copied over a scanning lens, typically a moving lens and light, in order to provide a uniform image.
- Developing the imaging by attracting toner powder to the relevant parts of the drum.
- Transferring the powder onto a piece of paper through a mix of electrostatic charge and pressure.
- Separate the paper from the belt or drum surface.
- Using a heat process to fuse the toner image to the paper.
- Cleaning the drum or belt using either a suction brush or a cleaning blade.
There are several variations to this system to allow for more economical use of toner, colour printing or smaller machines, but this is the most common process that is seen in every photocopier that uses the xerography process.
How Did It Become The Standard?
Xerography, which would provide the name for the company Xerox, was invented in 1938 by Chester Carlson, but it would take over 20 years from then until it became the universal standard for copiers.
At the time, duplication machines were complex and relied on somewhat expensive materials to create an initial duplication medium. These included systems such as the stencils in mimeographs, the special ink used in rolling copiers, and the carbon paper used in carbon copying.
As late as the 1950s, the most commonly used type of duplication system was Verifax, a patented process by Kodak that was simpler, but still required a somewhat expensive wet chemical process to expose and develop the duplicate.
By the 1960s, however, a fully-automated photocopier machine had been developed using xerography, and every other copying system had been reduced to a relative niche concern in office settings.
The only other major photocopying system used today relies on a combination of a digital scanner and inkjet printer, which tends to provide slower, lower-quality results.
Why Was Xerography Better Than Any Other System?
The biggest advantage xerography had over any other type of copier is that, whilst the initial price of machines was more expensive, the cost per print was a fifth of the cost of Verifax.
Between the relatively long-lasting toner cartridges and the ability to use standard office paper without extensive treatment, documents could be copied significantly faster and with far less effort.
This also allowed for the implementation of duplex printing, something that was impossible with earlier wet chemical processes and allowed for the production of booklets and even magazines to be printed with ease on a single machine.
As photocopies became more advanced following the Xerox 914 in 1960, increasingly sophisticated and labour-saving features began to be added.
The same technology that brought the world xerography was also used in laser printing, which would eventually lead to more advanced digital printing systems, print servers and the rise of word processing and desktop publishing.
The ability to use an automatic document feeder rather than a flat scanning surface meant that entire booklets could be scanned and photocopied, making it easier for schools and education centres to create large workbooks and reference texts.
Eventually, the addition of automatic sorting and stapling technology made this even easier, and offices could develop and print a wide range of document bundles without the sometimes-lengthy process of organising documents manually.
It is unlikely that xerography will stop being the dominant form of photocopying and printing technology, given the levels of refinement and sophistication the system has seen in the half-century since it became the standard.