Method for making a holographic linear position encoder
patents.google.com
patents.google.com
How would this be better for mass manufacture compared to a vernier pattern capacitive encoder as seen in cheap calipers such as [1] ? I'm pretty sure photodetectors would be more expensive than capacitive sensors.
AFAIK these are also based on an expired patent which i believe to be US4743902 [2], that was mainly used by Mitutoyo.
I don't know...
But... possibly!
I just thought that the title sounded extremely cool: "holographic linear position encoder", what's not cool or interesting about that?
I did not know what a Vernier Pattern was prior to reading your post (and subsequently researching it!), so let me summarize that endeavor:
Google, when queried with "Vernier Pattern" returns as its first entry a Wikipedia page about "Vernier Scale":
https://en.wikipedia.org/wiki/Vernier_scale
I asked Perplexity.ai if "Vernier Scale and Vernier Pattern" -- are the same thing...
Perplexity tells me that they are related -- but they are not exactly the same thing... Apparently (again, according to Perplexity) a Vernier Scale is a secondary measurement on a measuring device, and a Vernier Pattern refers to the physical pattern used to implement it...
Nonetheless, here is what should be a self-explanatory animated GIF showing how a Vernier Scale operates (from the previously mentioned Wikipedia page, above):
https://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Ve...
But, that's not the reason I'm posting the link to this GIF...
The reason I'm posting the link to this GIF is because the idea behind the Vernier Pattern / Vernier Scale -- might seem to potentially have some applications in other areas of Physics as well...
In other words, let's suppose we had two superimposed waves going in the same diretion of only the slightest difference in wavelength (much like the Vernier Pattern unit of measure is either slightly shorter or slightly longer than an adjacent measuring pattern...) OK, if that's the case, then note that the wave crests and troughs (much like the red marker at the point of intersection in the GIF) is moving faster -- than either of the two waves are, relative to one another...
An interesting effect, to be sure!
What are the potential future uses?
Well, we as-of-yet don't know! :-) <g> :-)
Anyway, great point about Vernier Patterns.
I learned something new!
https://en.wikipedia.org/wiki/Linear_encoder
>"A linear encoder is a sensor, transducer or readhead paired with a scale [measuring device] that encodes [retrieves, gets, fetches] position [from a physical system]."
(Patent (now expired) is one method of making an Optical Linear Encoder based on Holographic principles... a Holographic Optical Linear Encoder -- or perhaps just Holographic Linear Encoder -- for short...)