What Is a Scanner?
A scanner is a device that reads information by scanning an object with light.
Types of Scanners
There are two types of scanners: those that scan two-dimensional information and those that scan three-dimensional information.
Scanners that scan two-dimensional information generally refer to image scanners that scan printed materials as image data. Typical examples are flathead scanners and sheet-fed scanners (ADF scanners, auto-feed scanners), which are widely used to store and manage documents, photographs, and graphics.
Other types of scanners specialize in reading specific image information. These include passport scanners, business card scanners, film scanners that digitize negative and positive photo film, overhead scanners (book scanners, stand scanners) that scan books without cutting them (non-destructive self-catering), and pen scanners that convert text in books into text data. Barcode scanners (barcode readers) that read barcode information such as QR codes are also a type of image scanner.
Scanners that scan three-dimensional information are broadly defined as 3D scanners, and are used to read the physical shape of three-dimensional objects. Non-contact 3D scanners, which are widely used in industry, can be broadly classified into optical scanners and CT scanners.
Optical scanners are suitable for capturing data on the geometry of parts that are clearly visible from the outside. They are used for designing, dimensioning, and inspecting parts in the automotive, aerospace, defense, and manufacturing industries, as well as for surveying topography and large structures in the civil and construction industries. During optical scanning, the light that is irradiated onto the object can be either laser or patterned light.
CT scanners can nondestructively read the internal shape of an object based on the amount of radiation transmitted, and are widely used in the medical field as well as for the inspection of defective parts inside products.
Storage and Management of Scan Data
Conventionally, scanner data has been stored and managed on a PC connected to the scanner. Today, however, network scanners are widely used to store and distribute data without the need to operate a PC by connecting the scanner itself directly to a network.