Optel - Predecessor of the e-ink display?

[fronzelneekburm]

Found this article interesting, it is from Popular Electronics (january 1973). The Optel "REFLICON" tube sounded interesting, the principle reminded me of modern e-ink displays somehow...

optel.jpg

[peachykeen]

Interesting concept, but e-Ink paper works totally different.

[AlmightyTallest]

I had found some evidence that Optel had created some Electrochromic displays. There's a few patents from the same time period as your info for the Reflicon, around 1973 .

Unfortunately, I cannot find any other evidence other than this photo:



In the photo of the watch, below the display is says "Electrochromic"

[vpn]

Interesting article, thank you for sharing it, Stefan! Although I think that if such a display would've been put in production, it would be very unlikely that there would be a working specimen nowadays. (The electrochromic Seiko LCD comes in my mind)

[fronzelneekburm]

Very interesting finding regarding electrochromic displays!

I reminded the Doensen Book i have in the basement, i recently read about DSM watches in it and also caught the electrochromic term.

And - surprise or not - Optel had its fingers in it of course. They had a prototype displayed at the legendary Basle fair in 1972. To quote from Doensen:

L.3 Electrochromic LCD

The dull grey background of the field effect LCDs forced the industry to develop a high contrast display: the electrochromic display. The first electrochromic LCDs applied in watch- displays, were manufactured in 1982 by the Japanese company Sharp for Seiko Japan.

1 The only watch with this display ever produced in commercial quantities, was the ECD F623A by Seiko. The function is based on an electro-chemical process of the deposition (oxidation-reduction) of tungstentrioxide on the electrodes when the electrical current is flowing in one direction, and the removing of this material when the current is flowing in the opposite way. This process is comparable to the process of plating / deplating. In contrast with the field effect display, this display has a higher power dissipation and shows greater unreliability in the long term. The advantage is that the digits stay visible, even when no voltage is applied. The production stopped after two years. ETA manufactured a prototype with an electrochromic display in its 'Swissonic 2000' line, which was displayed at the Basle Fair of 1972. The research had been conducted by CEH and Optel and had been based on preceeding American Cyanamid patents.

Source:

http://doensen.home.xs4all.nl/l3.html



OK, maybe not exactlt what we call e-ink today... But the principle is the same. Apply power once to display something and it stays there even without electricity... Optel sure did a lot back in the days...

[AlmightyTallest]

It's pretty facinating stuff when you look into it, just a shame that none of the displays could survive like the Dynamic Scattering displays have.

ETA manufactured a prototype with an electrochromic display in its 'Swissonic 2000' line, which was displayed at the Basle Fair of 1972.

Now I wonder if the photo I had above is the example from the Basle fair from 1972, or is this a completely different watch, which no one seems to have a photo of. Would be neat to see if it was a differnt watch with Electrochromic display.

[azimuth_pl]

The only Swissonic 2000 watch mentioned in archives from 1972 is the one below.
It appears to have a DSM module.
On the other hand something that appears to be electrochromic with the very same layout is known as Texas Instruments watch developed for Longines LCD.
This one was also shown in Basle and awarded a design prize but it does not appear to have reached production quantities.

[AlmightyTallest]

Wow, neat photos and articles azimuth!!

The one with the Texas Instruments module with the bright white background with the digits could be the electrochromic prototype.

[azimuth_pl]

Forgot to post the earlier page of the book by Tom Hyltin.
It clearly says LCD so the electrochromic version appears to be mystery.
Unless people used to confuse electrochromic with LCD...as the difference is not that easy to notice.
Hyltin should now better than Pieter Doensen 30 years later considering that Hyltin did great research and published the book in 1975.
Anyways both pictures in the Popular Science article and the book...are poor quality drawings or enhanced images.