Facts about Fax

-Karthik Gurumurthy

Happy New Year 2003.

On this New Year day, I would like share about the Fax machine. 

Let me give you my take on the whole fax machine story:

So fax machines were basically these awesome devices that could zap documents anywhere in the world in seconds. Think of them as the OG document sharing before email attachments! You could send anything – typed letters, handwritten notes, photos, maps, even fingerprints – all through regular phone lines.

The way these things worked was pretty clever. You’d stick your document in the feeder tray, punch in the receiving fax number, and once the other machine answered, a roller would start pulling your document through. As it moved through, a super bright light would shine on it line by line, with 1,728 tiny sensors scanning each line (which was just 0.005 inch tall!). The scanner would divide each line into hundreds of tiny squares and measure how much light bounced back from each one – white areas reflected lots of light (weak electrical signal), dark areas absorbed light (strong signal).

These signals traveled through phone lines to the receiving machine, where a printing head would recreate the pattern. Every time it got a strong signal, it would make a dark spot on the paper. The higher the concentration of these spots (or resolution), the clearer the final image.

Fax machines came in three main flavors: ones with thermal printing heads using heat-sensitive paper (these had 2,000 heated wire tips that turned paper black where they touched), ones with photosensitive drums and toner like photocopiers, and the fancy ones with laser printers that made the sharpest copies.

The history of this tech goes way back! Scottish clockmaker Alexander Bain first proposed the principles in 1843, suggesting a pendulum-driven scanner to read metal plates. Then in 1847, Frederick Collier Bakewell built a simple fax using a rotating drum that transmitted images painted with shellac. He patented it in 1848, but it was never sold commercially.

Giovanni Caselli improved things in 1863 with his “pantelegraph” that used synchronized pendulums to scan ink drawings on metal plates. This system actually worked commercially between Paris and Lyon from 1865 to 1870!

Modern fax machines first showed up in America in 1924, sending photographs from Cleveland to New York. Newspapers became huge users, sending photos, articles, and weather maps. But the real explosion happened in the mid-1980s when businesses and regular people started using them.

By the mid-1990s, there were 2 million fax machines in U.S. homes, businesses, and government agencies, plus thousands in public places like shopping malls and office buildings where anyone could use them for a small fee. Millions more were used throughout Europe and Asia.

Faxing was cheaper and faster than sending letters or telegrams, or even having a phone call in many cases. Pretty revolutionary for its time – even though it seems ancient to us now!  I remember sending my first acceptance to Grad school via FAX from my best friend Susi’s dad Mr. CN Raman Uncle’s office  (Simplex Concrete Piles India )and it was fascinating or should I say Faxcinating?