Laser printer is a computer-driven printer that uses lasers to produce output on paper. A tiny, pinpoint laser electrically charges a light-sensitive drum in the image of the computer screen. Dry ink called toner is electrically charged and dusted onto the drum. The toner is given an electrical charge opposite to the charge on the parts of the drum where text and images are represented, so the toner sticks only to those parts of the drum. A sheet of paper is given an electrical charge matching but stronger than the drum's. When the paper is pressed against the drum, the oppositely charged toner transfers to the paper. The paper then passes through rollers that heat the paper for an instant, causing the toner to stick permanently to the paper. The result is a copy of the screen image on the paper. This technology was adapted from copying machines.