Basic Types of Scanning Devices

What are scanning devices?

Scanning devices are devices that use a magnetic or photo-electric source to scan and convert images into electric signals that can be processed by an electronic apparatus, such as a computer. Images that can be scanned and converted include colored or black and white texts, graphics, and pictures.

Uses of Scanning Devices

Scanning devices are commonly used to:

  • Convert a text document into an electronic file;
  • Convert a photograph into an electronic graphic file;
  • Sense an image to be sent over a voice frequency
  • Circuit, such as a fax machine;
  • Reproduce text and images, as with a copier.

Types of Scanning Devices

Scanning devices are generally of two types:

  • flat-bed scanner
  • This type of scanner operates by placing the text or image on the scanning device and a motor-driven scanner makes a pass or several passes over the document in order to scan it.

  • manually operated scanning device
  • With this type of scanning device, a hand-held scanner is moved over a text document or an image by an operator. The scan head, located at the base of the apparatus, scans an image as the device is drawn over the document or image.

    These types of scanning devices are typically fitted with horizontal and vertical grids on the top surface of the apparatus. These marks function as reference points to direct the operator to the location of the scan head device and the document being scanned. Often, the operator must precisely maintain the horizontal and vertical grids on the image.