Grades 3–5 · Machines
How does an inkjet printer turn tiny drops into a picture?
An inkjet picture is built from many small deposits of liquid ink. The printer turns the image into instructions for where and when drops should land. Moving paper and controlled nozzles work together, so a pattern appears instead of one large puddle.
In the diagramA piezo inkjet squeezes ink through tiny nozzlesVoltage bends a piezo elementDot plan+ timingInk chamberNozzlePaper advancesTimed droplets build the dots of the image.One piezo design; drops and distances are enlarged.
The drawing follows a piezo inkjet design. A piezoelectric element changes shape when a voltage is applied. Its movement changes pressure in a small ink chamber, pushing a drop through a tiny opening called a nozzle. The element can move again for the next pulse. Electrical energy is being turned into a small mechanical movement.
The chamber receives more ink as the element’s movement prepares it for another ejection. Many controlled pulses and many nozzles build up areas of a picture. Color printers combine deposits of different inks, and the paper affects how those deposits spread and dry. The diagram enlarges a single chamber to make its movement visible. Some other inkjet printers use heated vapor bubbles to push ink out; that is a different mechanism from the bending element shown here.
About this explanation
Starting knowledge: Understand small volumes, electrical control and a picture made of dots.
Sources
- Epson — Micro Piezo Inkjet Technology
- Epson — Thin-Film Piezoelectric Technology