HP Innovation Journal Issue 07: Summer 2017 | Page 20

INNOVATION SPOTLIGHT
3Decades of Inkjet
Building on a history of innovation
by K
 eith Moore, HP Fellow, Head of the Print Adjacencies and 3D Lab, HP Labs, HP
W
hen I was at college in 1985, we had
an HP 7475A plotter in the computer
room. It was by far the coolest thing
I had ever seen. Have you ever watched one?
It’s like watching an artist draw right in front of
The HP 7475A plotter,
circa 1985
you. To get it to draw, you had to write code.
You could get color if you swapped pens. I still
find plotters fascinating.
When I interviewed at HP, I plotted my re-
sume. My interviewing manager laughed when
he saw it and said, “Now that must have taken
hours.” (It did). “If you like plotters, you’ll love
this.” He handed me a copy of the 1985 HP
Journal article on the ThinkJet printer with the
The May 1985 issue of the HP Journal and the
disposable ThinkJet printhead cartridge—easily
replaceable and enough ink to print 500 pages
of normal text
20 Innovation Journal · Issue 7 · Summer 2017
simple statement that “this will change the
world.” He was right.
From ThinkJet
to PageWide
Array
The ThinkJet print-
er could print 120
characters per min-
ute at a resolution of The HP T200 InkJet Press, (pictured above), is able
to print 19 pages/second.
96x96 dots per inch. It
couldn’t do color, it couldn’t do graphics. In fact, Record for speed. All of this is protected with
it only had one font. “That will come,” he said. thousands of patents and inventors who have
I was hooked. HP didn’t just see a future, it created extraordinary things.
invented the future.
As I look back, I realize that where we are
It is truly incredible how much has changed. in 3D is exactly where we were in 2D nearly 30
Today, the HP T200 InkJet press is able to print years ago.
at 19 pages per second and the Niagara T3500
Poster printer can print 32 x 48 inch posters in HP 3D printing builds
3–4 seconds. Many people are familiar with on 2D InkJet
Moore’s law at Intel (no relation) where he ob-
served and predicted that the number of tran- The HP 3D printer just won the 2017 Invention
sistors per square inch on integrated circuits of the Year award. It is fun to watch, too. You
had doubled every year since their invention. only see one layer at a time though, and each
What we have seen is that the performance layer is printed in the blink of an eye. It is like
of InkJet in drops per sec- seeing sheets of paper, each with an image, all
ond has doubled every stacked together. Where the image is printed,
~18 months since the powder melts or fuses together causing a
1985. If you do the 3D object to be created layer by layer.
math, this is going
The original plotters and Inkjet printers had
from ~6K drops per invention in advancing a sheet of paper (using
second in 1985 to grit wheels), HP Jet Fusion printers have “pow-
almost ~10B drops der handling” inventions — the powder is spread
per second today.
so it looks like a blank sheet of paper and the
O u r d e s k t o p print heads can then add the design of the next
printers won the layer by placing very small drops of liquid onto
Guinness World the powder bed.