RCA VideoDisc's Legacy: Scanning Capacitance Microscope

Interestingly CD/DVD/BluRay optical pickup units can be used to build fluorescence [0]/laser [1] scanning microscopes, atomic force microscopes [2], nanoscale 3D printers [3], interferometers [4] etc, due to their high precision, low cost and high availability.

  [0] https://www.sciencedirect.com/science/article/pii/S2950435X24000283
  [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC6066758/
  [2] https://hackaday.io/project/186604-low-cost-and-high-speed-nanoscale-imaging-tool
  [3] https://www.nature.com/articles/s42005-021-00532-4
  [4] https://opg.optica.org/ol/abstract.cfm?uri=ol-24-10-670

There is a lovely youtube video series on the RCA video disc first episode here: https://www.youtube.com/watch?v=PnpX8d8zRIA

I got the CED collecting bug in 2010 when I came across a player. I keep it to show as a curiosity, a reminder that you can do things (video) in weird ways (a vinyl disc).

I have one memory of renting the SelectaVision player when I was very young.

This article on the SCM was new for me, and will be part of what I tell incredulous visitors in future!

I wrote an article about growing up with CED:

https://paleotronic.com/2024/01/27/the-horrors-of-capacitanc...

I had a friend who had one of those capacitive video disc players when I was a kid. Those got front of mind for me a few years ago when I noticed that a local fleas market had a lot of the discs but no players. I found out you could probably get a deadstock player on EBay but the belts would need replacing and when the stylus needed replacing… well they don’t make them anymore.

Required background music for reading the article: https://www.youtube.com/watch?v=Azsk21MpbUk

> The VideoDisc is sometimes confused with the LaserDisc, a home video technology of that era that used an optical laser.

I didn’t know this existed in 1964. It’s almost vinyl for video.