|MLA Citation:||Bloomfield, Louis A. "Question 1356"|
How Everything Works 20 Oct 2017. 20 Oct 2017 <http://howeverythingworks.org/print1.php?QNum=1356>.
As one of my readers (Tom O.) points out, most modern color copiers are essentially scanners plus color printers. They use infrared lasers to write the images optically onto four light-sensitive drums, one drum for each of the four colors (some systems reuse the same drum four times).