5-Segment Display

Back around 1973 - A proposal that challenges the traditional 7-segment display in common use today. This alternative uses less segments. Cheaper, no? It’s not too late to change.

I was trying to improve upon the 7-segment display which was fairly new at that time – found in such novel devices as digital wristwatches and electronic test instruments.

I reasoned that 7 segments were too many because 2^7 yields 128 permutations. We only require 10 to represent the digits. Since log(2)10 is about 3.3 it follows that at minimum we require 4 segments.

Everyone could save a lot of money with fewer segments – I had to hurry before the current design got entrenched…

Early rough sketches.

It was found that at least 5 segments are required for legible digits. 
This would still be nearly a 30% improvement.

My thought was to eventually build a giant clock using this design. The segments’ shape would be cut from black plexiglass. The holes would then be backed with red translucent plexiglass – rear illuminated with conventional incandescent bulbs. The front would be covered with a third sheet of smoked plexiglass to conceal the cut-out shapes until lit.

Here are some final designs. Also shown is a truth table for the digits (segments) and some experimental circuits for the segment drivers.

I never did build a clock based on my 5-segment display design. However I did build a JavaScript proof-of-concept simulator version in January 2015.


Revised 30 Mar 2015