scanners

Scanners are devices that convert physical documents, images, or objects into digital data for storage, display, or processing. They range from simple hand-held units to high-end industrial scanners and 3D scanners. Common categories include document scanners (flatbed, sheet-fed, portable); image or photo scanners designed for photographs or film; barcode scanners used in retail and logistics; and three-dimensional scanners that capture shape and texture of objects.

Most scanners use a light source and an imaging sensor such as a charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CIS) array to capture light reflected from the target. The sensor produces a two-dimensional image, with resolution specified as dots per inch (dpi) in optical terms. Color depth and grayscale levels determine image fidelity. Optical resolution is the true resolution; interpolated resolution may be higher and not increase real detail.

Scanners connect via USB, and higher-end models may use Ethernet or wireless links. They typically include software that performs image correction, color management, and may run optical character recognition (OCR) to convert text into editable content. Many devices conform to standards such as TWAIN or WIA to enable interoperability with various applications.

Use cases include digitizing paper archives, creating digital photos, scanning QR or barcodes, and, in manufacturing or healthcare, capturing 3D shapes or patient data. 3D scanners use structured light, laser triangulation, or computed tomography to model geometry and texture.