How does a scanner work?


Scanners might be an integral part of your workplace, whether in the office or at home. They make the digitisation of documents easy with their functions, but have you ever considered how a scanner works? 

First, you might be thinking why do we use scanners in the first place? 

Well, in a digital world like ours, it’s important that we have access to and can save and share a plethora of documents both at home and in the workplace. Through scanning we can digitise and archive documents, allowing us to copy, save and store them through scanning. 

How does a scanner work? 

Scanners work through a light source and a sensor, together they capture an image of the item being scanned. 

When you place a document on a scanning machine, the scanner’s light will illuminate it. An image of the document is reflected back onto a sensor. This sensor reads the reflected light and it is converted into electronic data. 

This electronic data can then be saved via your computer in a number of different types of files, depending on both your scanner and the settings that you choose. 

This file format can be easily shared or edited on a computer, or simply stored away for future reference. 

How does a document scanner work? 

A document scanner is specifically designed to scan documents, with most modern models incorporating CIS sensor technology. Whereas a flatbed scanner incorporates CCD optical technology, providing a greater depth of field, ideal for scanning photographs, artwork and documents at higher resolutions (dpi). Examples of A4 desktop document scanners would be the Canon DR-C240 and the Kodak alaris E1030. Both excellent A4 desktop scanners suitable for small office and home office working environments. For a limited time only Canon and Kodak are offering extended 3-year warraties with these scanners.

A document scanner will often use software called optical character recognition (OCR), this software recognises the text on the document and allows it to become editable text that can be copied and pasted into other documents. 

Document scanners feature additional extras like automatic document feeders (ADF), allowing you to stack numerous documents which are automatically fed into the scanner, thus saving valuable time. There are also duplex scanners that give you the ability to scan both sides of a document in a single pass. The market leading ScanSnap iX1600 incorporates all of the attributes mentioned above and currently ships with a FREE 3-year warranty.

The difference between a document scanner and a flatbed scanner 

The main difference between a document scanner and a flatbed scanner is how they intend to be used. A flatbed scanner is designed to scan a variety of things, like photographs, documents and artwork. Whereas a document scanner is designed to specifically scan documents and typically works a lot quicker than a flatbed scanner. 

Scanner bed size - a flatbed scanner will typically have a larger scanning bed than a document scanner. This is because they must accommodate for a variety of different items. Document scanners are designed for scanning all document sizes up to A4, although some larger production scanners will scan up to A3 documents.

Scanning speed - Document scanners are designed to scan at a quicker pace and scan multiple pages quickly. Flatbed scanners will typically take longer to scan, especially when it comes to scanning larger items at higher resolutions. 

Resolution - Flatbed scanners will typically have a better resolution than document scanners, which are designed for simple text documents. As flatbed scanners are often used to scan images and artwork, which will typically contain more detail, higher resolutions need to be set. 

Different types of scanners 

Flatbed Scanners 

As mentioned above A4 and A3 Flatbed scanners are predominantly used to scan photographs, graphic art, x-rays and in some instances film. Flatbed scanners are larger than A4 desktop scanners and rely on a large glass flatbed for scanning 2D objects (although smaller 3D artworks can also be scanned e.g., pens). The glass flatbed is accessible by lifting a hinged lid that protects the glass flatbed and once closed, cuts down on reflections. Epson lead the way in A4 and A3 flatbed scanners. At the low end of the market is the Epson Perfection V39 A4 flatbed scanner (CIS sensor) which is a great entry level option, for those wanting to try flatbed scanning for the first time. A more accomplished A4 flatbed option would be the Epson Perfection V600 A4 flatbed scanner which incorporates CCD optical technology and can scan artworks, photographs and 35mm, 120mm film. For professionals that need high quality scanning up to A3 in size, there is no better A3 flatbed scanner on the market than the Epson Expression 12000XL Pro.

A4 Desktop Scanners

Compact, A4 desktop scanners are ideal for home or small office use and are perfect for new hybrid work styles.

Portable Scanners 

A4 mini scanners are similar to A4 desktop scanners in terms of technology but they are a lot more compact and small enough to carry in a bag - ideal if you are regularly on the move. Typically, these scanners don’t incorporate an automatic document feeder (ADF) therefore documents need to be scanned singularly. but a great portable option, nonetheless. All the major desktop scanner manufacturers provide excellent choices within this category, here are some great examples - Brother DS-940DW portable wireless scanner, ScanSnap iX100 portable wireless scanner and the Canon imageFORMULA R10 which incorporates a 20 sheet automatic document feeder (ADF).

3D scanners 

These work completely differently to traditional scanners. Instead, the technology collects distance point measurements, which helps to translate the product into a 3D object.

Published June 2023.