From Longman Dictionary of Contemporary Englishlight penˈlight pen noun [countable] TDa piece of equipment like a pen, used to draw or write on a computer screen
Examples from the Corpus
light pen• And when the program is ready, the student enters it simply by moving a light pen across the bar codes.• When the light pen is moved over the code, it triggers the chips to make sound through the loudspeaker.From Longman Business Dictionarylight penˈlight pen noun [countable]COMPUTING a special piece of equipment shaped like a pen, used to read printed computer codes on product labelsThe TX-2 uses a light pen to enter data straight on to the system. 