Scanners are devices for scanning the original, which is most often a document or an image, and then converting it into digital form. You can then continue working on the scanned document, send by e-mail, or post it on a website. The most common are flatbed scanners that work in sync with a computer. The paper is placed on a glass window and the scanner then scans it using its image sensor. Scanner differ mostly in their scanning resolution, speed, and features.
Desktop flatbed scanners
A popular and widely used scanner type. You place a sheet of paper, whether with text or images, on the glass window and it gets scanned by the scanning mechanism beneath it. These scanners are notable for their excellent scanning quality. They are mostly designed for A4 format sheets, though select models can accommodate A3 as well. They take up more space than sheetfed scanners.
Desktop sheetfed scanners with a document feeder
They work on a similar principle as fax machines. You put a paper sheet in the tray and the sheet then passes through the scanner mechanism. Sheetfed scanners take up less space on your desk than flatbed scanners, but they rarely support documents larger than A4. This type is suitable for scanning large volumes of documents, because they are faster than flatbed scanners. On the other hand, they are not suitable for scanning books and magazines, since you can only insert a single sheet.
Scanners for film strips. They are more expensive than flatbed scanners, but offer higher colour depth and better resolution.
Small scanners for occasional scanning in the office or on the go. They are powered via a USB connector and are suitable for business travellers, for example. The downside is that their small and compact size requires some compromises, so they provide lower quality scanning than other scanner types.
Handheld and ergonomic, they are commonly used in shops, warehouses, etc.
|Flatbed scanners||Sheetfed scanners||Film scanners||Portable scanners||Barcode scanners|
Listed in DPI (dots per inch, i.e. the number of pixels per inch). The higher resolution the scanner has, the better and more detailed the scanning results. Most modern scanners offer a resolution of at least 1200 × 2400DPI. This is generally enough for normal home or office use, since common text and image documents rarely require top-notch scanner resolution. For more advanced users who work with detailed graphic design, we recommend a scanner with a higher resolution. Some models support scanning at 4800 x 9600DPI, for example.
Tip: Higher resolution always means better quality, but it also creates a larger document size and places higher demands on your PC hardware. If you want to work with high-resolution scans without any hassle, you should have a PC with an Intel Core i5 or i7 processor and an NVIDIA GeForce GTX or Quadro graphics card.
Most scanners scan the original in 20-30 seconds; faster models can even do in 10 seconds. However, the scanning speed is also affected by the set scanning resolution and the overall performance of your computer. If you have a powerful PC and set a lower resolution (quality), your documents will get scanned faster.
Today's scanners feature the standard USB interface that supports high-speed communication between the scanner and the computer. Almost all today's computers support USB. Sometimes you can also encounter the SCSI connector. Some models are equipped with WiFi technology that aloo’s you to send scans wirelessly to a computer, smartphone, or tablet.
Tip: Always make sure that your computer has the same connectors as your chosen scanner before buying. Otherwise, you would have to use adapters.
The amount of pixels per inch in scanned documents. The scanned document data size increases with the DPI count.
Single-sided scanning. The device can scan only one side of the inserted document. To scan the other side, you have to flip and reinsert the page.
Two-sided scanning. These scanners can automatically scan a sheet of paper on both sides without the need to flip the sheet.Glossary