Talk:Image dissector

This entry should be moved to the Video camera tube page and integrated therein.

I just requested this -- it'll probably get done soon. Cheers, Rico402 (talk) 22:03, 30 July 2009 (UTC)

he was born in utah not idaho. fixed it. Arc88 19:10, 10 April 2007 (UTC)

But he was a teenage farmboy from Idaho. That is, Idaho is where he was a teenage farm boy. Is there a better way to say it? Putting his place of birth here is at least as misleading as the original. Dicklyon 19:58, 10 April 2007 (UTC)

How it worked

discussion copied to here from User talk:Dicklyon#Image Dissector for continuation, by User:Dicklyon:

You recently reverted my edit of the description of the Farnsworth Image Dissector saying that it sounded like the operation of Zworykin's design; it does, because they are fairly similar. Please consult the patent application referenced at the bottom of the page which clearly states that the primary method of scansion is detection of the surplus electrons deflected back to the electron gun. Gordon —Preceding unsigned comment added by 130.159.248.36 (talk) 13:11, 15 December 2008 (UTC)

But you didn't cite a source. It would be best to cite a secondary source that explains it, rather than give your own interpretation of the patent. Dicklyon (talk) 16:00, 15 December 2008 (UTC)

I agree, sources should be cited. I wasn't however trying to improve the article, I was trying to correct factual inaccuracies I had noticed in my research. I would write a better article if I had the time. "Interpretation" aside, the account I gave was a summary of the description contained in the patent, the current revision as reverted by you is wrong. I fail to see why citing a secondary source as you suggest would be beneficial; I would then be giving my interpretation of someone else's interpretation of the patent. I agree that my revision is not necessarily any better in terms of an acceptable article for Wikipedia, but it was at least true. Arbitrary reversion by you to a false description is bewildering. Gordon 78.105.184.134 (talk) 21:37, 15 December 2008 (UTC)

Don't be bewildered. See WP:BRD; you were bold, I reverted because I doubted the correctness based on the lack of sourcing, now we're discussing it. My revert was to get your attention to the problem of making your change verifiable, so that if it is it will stick. Now that you say it's pretty much straight from the patent, it should be easy to simply cite that. But also see Wikipedia:RS#Primary.2C_secondary.2C_and_tertiary_sources about why secondary sources are preferred. Dicklyon (talk) 23:03, 15 December 2008 (UTC)

So I've been looking in Farnsworth's patent filed in 1927, and can't find where you got this stuff. The one you were looking at was the 1933 filing, by which time he had incorporated a storage feature like Zworykin's apparently. So it is my impression that your description does not apply to the original image dissector. If we had a secondary source to help put all this into perspective, that could be very useful. Dicklyon (talk) 01:41, 16 December 2008 (UTC)

Hey there. As to the Image Dissector. I've done a lot of editing on it recently. It was being described badly, based upon the 1933 patent for a "second generation" dissector that really wasn't a dissector at all, but a storage camera (like the iconoscope) with a new feature--low velocity electrons. Nobody else, not even Zworykin, had come up with that yet. I reworked the major descriptions, added links to the original patents, and pointed out the features of this newer dissector. Playerpage (talk) 14:48, 19 November 2009 (UTC)

And what you have wrote down is wrong. You firstly wrote that the second generation image dissectors included an "electron multiplier", and then you also stated that this second generation uses a low velocity electron scanning beam. So which is the real version?, is it the "electron multiplier" version or the low velocity electron scanning beam one?

On the other hand, Farnsworth's US patent 2,087,683 is a very representative case. It is very difficult to control a low velocity electron scanning beam, because the electrons in the beam tend to "spread" when the image's borders and corners are scanned, so that one gets an image that is very well focused in the center but blurry in the borders. Iams and Rose were the first ones in solving this problem by using special scanning plates and coils. So that Farnsworth filed a patent for the low velocity electron scanning beam in 1933, but Rose designed and build the first working version of a tube that uses a low velocity electron scanning beam in 1941-1942. And this is not the first time that this situation appears: Dieckmann a Hell filed a patent for the image dissextor in 1925, but Farnsworth designed and build the first image dissector in 1927-1928. --189.216.104.69 (talk) 21:24, 16 January 2010 (UTC)

Two Historical Notes

One of the first all-electronic video camera tubes was invented in France by Edvard-Gustav Schoultz in 1921. He filed the French patent FR-539-613 on August 23, 1921. The patent was accepted on April 5, 1922, and published on June 28, 1922. You can find a copy of the original document in the web page [[1]]

The Image Dissector was also invented in Germany by Max Diekmann and Rudolf Hell in 1925. They filed the German patent DE-450-187 on April 5, 1925. The patent was accepted on September 15, 1927, and published on October 3, 1927. You can find a copy of the original document in the web page [[2]]

--134.153.204.160 (talk) 15:50, 24 July 2009 (UTC)

And nether bore more than a passing resemblance (if that) to Farnsworth's design, which actually produced an image. (Imagine that! A device that not only bore a patent, but did what it claimed to do.) Wasn't it Hell himself who said they couldn't get the thing to work because the didn't understand how to focus electron beams ("electron optics")? Cheers, Rico402 (talk) 06:57, 31 July 2009 (UTC)

Indeed, there's a lot to be said for getting one's invention to work. In wikipedia, it's a losing game to engage in invention priority disputes based on primary sources like patents. I think we just shouldn't allow that. It's OK to report the existence of these early patents, but statements about exactly what was invented, or who should get credit for what, definitely need to be backed up by secondary sources. Even then, there will be disagreements, in which case we should simply report who takes what sides, and avoid taking sides ourselves. Dicklyon (talk) 07:05, 31 July 2009 (UTC)

So would you support routine reverts (judiciously applied) when someone inserts a specious claim into an article based solely on a patent, without first doing a song and dance on the Talk page? (Cause I've been seeing, and doing, a lot of that. :) Cheers, Rico402 (talk) 07:35, 31 July 2009 (UTC)

Personally, I'm big on the "R" step in WP:BRD; the "D" can follow if the reverted editor wants to make a case. Especially on issues of priority and invention, we have no business making claims based on primary sources. One can say "X filed a patent application on similar device in Y year", but not "X gets credit for inventing...". But even there, if "similar device" is subject to dispute, and not verifiable in secondary sources, that should be taken out. Dicklyon (talk) 16:36, 31 July 2009 (UTC)

I think it should be noted, as well, that we at Wikipedia do not represent the sum total of all Wisdom. We may be trying to pool all knowledge, but that is a different thing. An example can be found in the Farnsworth debate. During the heady days of invention, he grabbed as many headlines as his colleagues. After the world settled into the drive to buy TV's, he was lost in the corporate siren of RCA's marketing dept. It is only in the last 25 years that he has emerged from the shadows to be taken more seriously for the contributions he made. A single thought, from a single individual, should never be the end-all of the debate. That was what happened to Farnsworth. Careful documentation, many verifiable sources, and what is the community at large--both inside and outside Wikipedia, inside and outside whatever discipline is being covered even--saying on the subject? Playerpage (talk) 15:00, 19 November 2009 (UTC)

Topic of this article

The topic is Farnsworth's image dissector, not the history of television. It would be OK to have a brief section on other inventions around the same time, but to hijack the lead to give credit for his invention to others seems inappropriate here. Agree? Dicklyon (talk) 02:58, 31 July 2009 (UTC)

I asked admin VirtualSteve to protect the article -- protection template in place til 7 Aug. Cheers, Rico402 (talk) 05:46, 31 July 2009 (UTC)

Seems like overkill at this point, but still, the anons can make their case here on the talk page if they wish. Dicklyon (talk) 06:20, 31 July 2009 (UTC)

I wouldn't call it overkill -- every article re television has been under attack; one can hardly keep up. The same specious crap has been popping up like weeds all over the place. All the time wasted on reverts could have been spent actually improving the articles.

And 134.153.204.160 posted his "Two Historical Notes" on nearly every Talk page having anything to do with television. The list of "twelve patents for an all-electronic video camera tube filed or issued before Farnsworth's" was posted nearly everywhere as well. But I don't think these guys mucked up the actual articles. Cheers, Rico402 (talk) 07:22, 31 July 2009 (UTC)

Someone has to clean this article

Someone has to clean the redaction of this article because it is horrible. It is firstly said that: second generation dissectors equipped with Electron Multipliers, as they came to be known, were in demand by RCA for their unique technology. RCA leased the technology from Farnsworth in 1939 and incorporated it into their future television systems.

As far as I know, the electron multiplier was invented by Joseph Slepian in April 1919 [[3]]; and the multi-stage electron multiplier was developed by Kubetsky in 1933 [[4]]. Thus could anyone please explain me why RCA would lease the electron multiplier technology from Farnsworth, instead of leasing it from Slepian? I wonder the author is not trying to say that Farnsworth also invented the electron multiplier.

It is later said that: Farnsworth submitted a patent application for a second-generation Image Dissector in 1933, based on what he learned working with his original designs and the multipactor. The new Image Dissector — actually a cathode-ray tube (CRT), and the first to use a low velocity electron scanning beam — would become the ancestor of the Image Orthicon tube, ...

What? Farnsworth invented the low velocity electron scanning beam in April 1933 [[5]], introduced (but did not invent) the one-stage electron multiplier in January 1928 [[6]] [[7]], invented the multicaptor multiplier in October 1933 [[8]], and used a two-stage electron multiplier (2 dynodes) in April 1937 [[9]]. A multi-stage electron multiplier (5 dynodes) was then introduced in August 1937 [[10]]. Thus what makes a second generation image dissector?, is it the electron multiplier or the low velocity electron scanning beam?, please make your mind.

Even the ITT image dissectors with modern electron multipliers (12 dynodes) were not as sensible so as to be used in outside broadcasting, they were reserved for industrial applications [[11]], [[12]], and [[13]]. The real solution for the inefficiency problem was not the electron multiplier, but the charge storage principle. By the way, Farnsworth's US patent 2,087,683 was based in Tihanyi's work from 1928 [[14]], [[15]], and [[16]]. Yes indeed, Farnsworth did have access to Tihanyi's british patents published in 1930. Finally the first practical and all-functional iconoscope was build in November 1931 and presented to the general public in June 1933, the year 1934 is just wrong.

--148.247.186.142 (talk) 01:27, 15 January 2010 (UTC)