Question

what is light pen????

Answer 1

A handheld pen like photosensitive device held to the display screen of a computer terminal for passing information to the computer . THANKYOU

Answer 2

A light pen is used to draw lines or images on the screen. Light pens do not generate any light, instead they contain photocell to detect the presence of light. When a light pen touches the monitor, light is detected from the screen enabling the computer to identify the location of the pen on the screen..
Hope it will help you friend....