Types of Scanners
Digital scanners come in all forms and sizes depending on the main application. For business uses, generally scanners are needed for documents and graphics, so appropriate types of scanners are most often combined with copiers and printers into a single unit to be more productive, economical and environmentally-friendly.
The traditional type of digital scanner is the Flatbed, which is the mechanism found in the common, original photocopiers. By raising a lid, the document can be placed on a clear glass plate, with a moving light beneath to start the process of projecting and copying the image from the original once the lid is placed down and the scanning/copying is initiated by the user.
The two main disadvantages of flatbed scanners are the limited area of the glass plate, and that only one side can be scanned at a time, making it a manual process for a double-sided document. However, the advantage of the traditional flatbed scanner is that the document is given a completely flat surface and straight edges to align the document in as original form as possible. Flatbed lids also allow you to keep the scanning component unexposed and clean.
Sheet-Feed Scanners
Sheet-Feed scanners are essentially for fast scanning of single sheets of paper representing a document or image. The mechanism is simply for the original sheet of paper to be inserted into a paper feed tray – often a vertically angled stand that allows the paper to slot into the machine.
With the paper inserted in the right direction, the user initiates the scanning process and the scanner machine will pull the paper in to pass it through an internal scanning component.
The scanning component is not dissimilar to the flatbed type of scanner, but instead of manually placing the original onto a clear glass plate for light to pass and reflect the image, the paper is fed passed an area that light can be projected onto the paper and reflected onto internal sensors.
Older sheet-feed scanners were manual, so that when the user manually inserts a sheet into the open slot of the machine, the machines knows to begin the scanning process. Now automatic sheet-feed scanners are designed to use a paper feed component, which upon the user initiating the scanning process, collects the topmost sheet of paper from the paper tray, and continues to collect any further sheets if there is a stack.
For a more practical design, automatic sheet-feed scanners (and scanner copiers) are build with an inclined horizontal paper feed tray – instead of the traditional vertical design – so that it is easier to stack papers and the automatic collection of each sheet of paper is quicker and more efficient.
The advantages of sheet-feed scanners (and thus also scanner copiers) mostly benefit environments in which a large number of single sheets of documents require fast scanning or photocopying, particularly in high volume. However, sheet-feed scanners can often be restrictive in size
Duplex Scanners
Duplex scanners have a specific function of scanning both sides of a document sheet. They essentially take the form of sheet-feed scanners, but the internal mechanism is to transport the paper through the scanning system so that each side is exposed one after another to the light reflecting the current side of the document.
Duplex scanners are now readily available as integrated into a copier, so that there is scope for duplex photocopying. It makes scanning and photocopier even faster and efficient where double-sided document information is required to be copied or electronically stored.
As it is typically a sheet-feed mechanism using a paper feed tray, many double-sided sheets can be stacked and automatically copied or scanned. However, this limits the original document to being single, independent sheets of paper, and usually restricted in size.
Wide Format Scanners
Wide Format refers to the larger sizes demanded by graphics media, such as for banners, posters and other large size applications for copy, scanning and printing.
Wide format scanners accept original documents from small to large sizes through a sheet-feed system, and stored digitally on a computer or server. This is particularly useful for large size arts and graphics, especially as flatbed scanners and regular sheet-feed scanners are extremely limited on the size they can scan.
When integrated with a copier, wide format scanner copiers can take small and regular size documents for large size copy production; but also the ability to copy large size documents to rescale.