MicrobeHunter.com Microscopy Forum

I have just discovered an interesting Zeiss patent from 1933
https://worldwide.espacenet.com/patent/ ... DGB396325A

This surely begs to be converted to LED

.... another ‘project’ for the list.

MichaelG.

That does sound good. Can you order them?

DonSchaeffer wrote: ↑

Wed Jun 24, 2020 5:13 pm

That does sound good. Can you order them?

.

I have no idea whether they were ever made, Don

MichaelG.

Of similar vintage ... but much less attractive to me:
https://worldwide.espacenet.com/patent/ ... DGB401591A

MichaelG.

Michael,
Some time ago I "followed" the first Zeiss patent without even being aware of its existence... using LEDs of course. First, a single LED, then a LED ring. They point radially and horizontally, are not tilted, and set around the obejective, with a cloth sleeve diffuser within. Primitive, but it does a decent job...
viewtopic.php?f=6&t=7504&hilit=FORAMINIFERA&start=30

Hobbyst46 wrote: ↑

Sat Jun 27, 2020 10:34 am

Michael,
Some time ago I "followed" the first Zeiss patent without even being aware of its existence... using LEDs of course. First, a single LED, then a LED ring. They point radially and horizontally, are not tilted, and set around the obejective, with a cloth sleeve diffuser within. Primitive, but it does a decent job...
viewtopic.php?f=6&t=7504&hilit=FORAMINIFERA&start=30

Thanks for the reminder of that ^^^

There is, however, one very significant difference ... The [Zeiss] use of the ball lens makes it ‘hard’ illumination, like a spotlight, rather than the softer effect that you were achieving.

There is, of course, merit in both approaches.

MichaelG.

Hi MicaelG.
If you are looking for narrow beam LED's you can get them down to 15 degrees from Conrad.
See here:-

https://www.conrad.de/de/p/thomsen-led- ... 80001.html

Roldorf wrote: ↑

Sat Jun 27, 2020 12:42 pm

Hi MicaelG.
If you are looking for narrow beam LED's you can get them down to 15 degrees from Conrad.
See here:-

https://www.conrad.de/de/p/thomsen-led- ... 80001.html

.
Thanks, but that is still a diverging beam ... the ball lens gives a converging beam.
.
.
MichaelG.

MichaelG. wrote: ↑

Sat Jun 27, 2020 1:03 pm

Thanks, but that is still a diverging beam ... the ball lens gives a converging beam.

I wonder what is the purpose of the claimed gadget - adjustable oblique illumination for low-NA objectives ?

according to the artical they say:

'This ample scope in the choice of the illumination is very advantageous, since certain structures of objects are known to be discernible only when struck bv light incident at a definite azimuthal angle and a definite inclination, which are frequently unknown at the outset.'

MichaelG. wrote: ↑

Wed Jun 24, 2020 10:12 am

I have just discovered an interesting Zeiss patent from 1933
https://worldwide.espacenet.com/patent/ ... DGB396325A

... and this appears to be the production version of it:
.
http://www.science-info.net/docs/zeiss/ ... alogue.pdf

Lots of interesting stuff in there, including the early Ultraphot.

MichaelG.

MichaelG. wrote: ↑

Sat Jun 27, 2020 5:38 pm

http://www.science-info.net/docs/zeiss/ ... alogue.pdf

The following is my favorite from that Catalogue in the link

I wonder. What is a slow motion head?

Roldorf wrote: ↑

Sun Jun 28, 2020 12:04 pm

I wonder. What is a slow motion head?

After a short laugh I realized that "slow" reads "fine" here. As one rotates the knob, the head slowly changes vertical position, since the pitch is fine...

yes those German to English translations can be a bit 'trippy'.

Spencer mwnufactured a version of this after the first w.w. I think it is in the 1917 catalogue.

https://pubs.acs.org/doi/abs/10.1021/ie50108a024


The Zeiss model , appears to be specifically an oblique illuminator.

apochronaut wrote: ↑

Sun Jun 28, 2020 6:14 pm

Spencer mwnufactured a version of this after the first w.w. I think it is in the 1917 catalogue.

https://pubs.acs.org/doi/abs/10.1021/ie50108a024


The Zeiss model , appears to be specifically an oblique illuminator.

The Silverman illuminator shown in the I&EC Journal (the link above) is based on an ordinary bulb, without lens. It yields an oblique beam.
So I again wonder, what is the advantage, if any, of the lens used in the Zeiss patent. Was it added only because Zeiss considered it a must for sufficient brightness - or was it included in the patent but omitted for the final marketed product.

Hobbyst46 wrote: ↑

Sun Jun 28, 2020 6:38 pm

.
So I again wonder, what is the advantage, if any, of the lens used in the Zeiss patent. Was it added only because Zeiss considered it a must for sufficient brightness - or was it included in the patent but omitted for the final marketed product.

.
So again I tell you ... The ball lens produces [in a very compact arrangement] a tiny focused spotlight.
As drawn in the patent it would produce approximately a 1:1 image of the lamp filament.
Ball lenses are now widely used in this mode for coupling fibre-optic cables ... but it was, I think, quite innovative in 1933.

MichaelG.
.

https://www.rp-photonics.com/ball_lenses.html

MichaelG. wrote: ↑

Sun Jun 28, 2020 7:13 pm

Hobbyst46 wrote: ↑

Sun Jun 28, 2020 6:38 pm

.
So I again wonder, what is the advantage, if any, of the lens used in the Zeiss patent. Was it added only because Zeiss considered it a must for sufficient brightness - or was it included in the patent but omitted for the final marketed product.

.
So again I tell you ... The ball lens produces [in a very compact arrangement] a tiny focused spotlight.
As drawn in the patent it would produce approximately a 1:1 image of the lamp filament.
Ball lenses are now widely used in this mode for coupling fibre-optic cables ... but it was, I think, quite innovative in 1933.

MichaelG.

In fact, in the past I illuminated a strew diatom slide with a 0.6mm diameter silica fiber optic "from the side", but the fiber, though flexible, could not be rotated around the objective as in the patent... a rotating stage is needed, and owing to the kind help from 75RR, I now have one; perhaps a future job. But without a ball lens...so still divergent.

The Silverman illuminator used an annular tungsten filament, similar in principal to those G.E. Lumiline bulbs which were quite common along either side of vanity mirrors at one time. The filament covered about 300° . The concept was for even illumination and it's application would be most valuable for moderate magnifications in metallurgy.

I would think that the principle of the Zeiss illuminator leads it's application to a spot illumination for higher magnifications. With the Silverman design, when using a high magnification, it might be difficult for the light to penetrate under objectives with close working distances; 4mm f.l. and lower. The literature does make note of using different voltages in order to increase output.

With it's focusing optic the Zeiss unit, seems ideally designed to focus a small intense spot into a small w.d. Oblique, yes but if not required , I am sure 2 or 3 vould be used.

apochronaut wrote: ↑

Sun Jun 28, 2020 7:42 pm

The Silverman illuminator used an annular tungsten filament, similar in principal to those G.E. Lumiline bulbs which were quite common along either side of vanity mirrors at one time. The filament covered about 300° . The concept was for even illumination and it's application would be most valuable for moderate magnifications in metallurgy.

.

Found it ... here: https://ia902806.us.archive.org/3/items ... 735mbp.pdf
[ fabulous book from 1944 ]

. .
The notes about its heat output must make us grateful for our LEDs

MichaelG.

it was used with metals mostly.

apochronaut wrote: ↑

Sun Jun 28, 2020 10:26 pm

it was used with metals mostly.

The note is actually about choice of objective [appropriate price range]

MichaelG.

MichaelG. wrote: ↑

Sun Jun 28, 2020 9:14 pm

apochronaut wrote: ↑

Sun Jun 28, 2020 7:42 pm

The Silverman illuminator used an annular tungsten filament, similar in principal to those G.E. Lumiline bulbs which were quite common along either side of vanity mirrors at one time. The filament covered about 300° . The concept was for even illumination and it's application would be most valuable for moderate magnifications in metallurgy.

Found it ... here: https://ia902806.us.archive.org/3/items ... 735mbp.pdf
[ fabulous book from 1944 ]
The notes about its heat output must make us grateful for our LEDs
MichaelG.

Indeed, the book does not mention the Zeiss patent from 1937; strongly supports your hypothesis that the latter was never on the market.

MichaelG. wrote: ↑

Wed Jun 24, 2020 10:12 am

I have just discovered an interesting Zeiss patent from 1933
https://worldwide.espacenet.com/patent/ ... DGB396325A

This surely begs to be converted to LED

.... another ‘project’ for the list.

Yes, and yes !

I have LEDs but no optical marbles !
Other than calling up van Leeuwenhoek's spirit,, any ideas ?
Do you think a short focus plano lens (ex laser) might suffice ?

Academic in this age : Have you the main body of the patent, the abstract is not clear on the claim(s) to novelty.

Mraster2 wrote: ↑

Mon Jun 29, 2020 6:31 pm

.
Yes, and yes !

I have LEDs but no optical marbles !
Other than calling up van Leeuwenhoek's spirit,, any ideas ?
Do you think a short focus plano lens (ex laser) might suffice ?

Academic in this age : Have you the main body of the patent, the abstract is not clear on the claim(s) to novelty.

.

Welcome to the adventure !!

l will return to ‘optical marbles’ when I have tested something ... but meanwhile:
The full document is available from the link that I provided
Click the three vertical dots near the top-right of the page and follow your nose.

If you have difficulty, I can put a copy in my dropbox

MichaelG.

MichaelG. wrote: ↑

Mon Jun 29, 2020 7:26 pm

three vertical dots near the top-right of the page and follow your nose.

Well done, got it now thanks, I followed your trail of white pebbles

For info.

Scaling from the patent drawing, the ball lens looks like 8mm diameter.

MichaelG.

On an initial quick read** through it didnt seem to me that the ball lens was a big claim ?
More to do with the mobility of the direction of the (converging) light, or lights if more than one are [s]required[/s] to be experimented with.

I put converging in brackets cos they dont seem to be specifically requiring that as part of the novel claim, the emphasis is more on the novelty of being able to conveniently adjust the direction, 360*. The convergence is mentioned 'en passant' and not quantitatively ?? So there is scope for experiment not only with a filament, aka led, at the conjugate focus of the ball from the specimen , but somewhere else at up to infinity of lens ? ha, that should occupy a few more months of lockdown !

** and then would you adam&eve it - the lights went out, a power cut in southern England in 2020 !pah.

MichaelG. wrote: ↑

Mon Jun 29, 2020 11:02 pm

For info.

Scaling from the patent drawing, the ball lens looks like 8mm diameter.

MichaelG.

Edmunds has 8mm ball lenses for $35. A bit pricey. Maybe two hemispheres could be found on the surplus shed and joined.