Bar-code readers use ____that sweep a narrow beam back and forth across the bar code.
A) scanning LEDs
B) high-intensity lamps
C) high resolution CCDs
D) scanning lasers

Question

Quizplus · Accepted Answer

Bar-code readers use scanning lasers to sweep a narrow beam back and forth across the bar code. This allows the reader to detect and decode the information encoded in the bar code. Scanning LEDs and high-intensity lamps may be used for illumination, but the actual scanning mechanism is typically a scanning laser. High-resolution CCDs may be used to capture images of the bar code, but they still require a scanning mechanism to sweep across the bar code.

Bar-Code Readers Use ____That Sweep a Narrow Beam Back and Forth