A light-sensitive device that converts the printed text, drawing, or other images into digital form is called -

Optical scanner/Scanner, a computer input device that uses a light beam to scan codes, text, or graphic images directly into a computer or computer system.
Bar-code scanners are used widely at point-of-sale terminals in retail stores.
A handheld scanner or bar-code pen is moved across the code, or the code itself is moved by hand across a scanner built into a checkout counter or other surface, and the computer stores or immediately processes the data in the bar code.
Source: www.britannica.com