The Last Lone Inventor

[indago]

I stopped by Book Baron (www.bookbaron.com) yesterday and picked up a
$7 used paperback of The Last Lone Inventor (http://www.lastlone.com).
I've been reading a few chapters of the story of Television, Philo T.
Farnsworth and David Sarnoff, which everyone should read. Right now
you are probably watching a CRT which was invented by Farnsworth.
It's truly amazing. Little did he know how much his invention would
change the world.

See my .sig below for a URL to buy this, or any used book. Also,
check www.abebooks.com.

There have been a couple of good programs on the History Channel concerning
this subject. Very interesting, and informative. Also, the programs on
Tesla, Edison, and Westinghouse...

 

[indago]

My mistake, I thought an inventor was someone who invents things and figured
Tony Blair did a lot of that.

Tony Blair is a talking head on FoxNews...

 

[Winfield Hill]

Mjolinor wrote...

Stepan wrote ...

My mistake, I thought an inventor was someone who invents things
and figured Tony Blair did a lot of that.

LOL.

Thanks,
- Win

 

[George Steber]

PBS did a special on Philo a few years ago. It shows an actual working
picture tube with $ sign on it to impress investors. Lots of nice interviews
with people/ engineers who were there at the time.

George

 

[Jeff Liebermann]

As compared to NOTHING. The original CRT's had a gun and a target
face. It was flood illuminated. Virtually useless.

Actually, there were several inventors that attached a rotating ring
of magnets around the CRT neck to create a receiver display suitable
for the original mechanical disk scanner TV cameras. The image was
kinda like a spirally rotating blob on the screen, which was excatly
what was needed for a mechanical scanner. Unfortunately, I can't find
any references or photos on the web. As always, synchronizing the
camera and display were the major challenge.

The "big leap forward" thing that Farnsworth did was to visualize
scanning lines.
Jeff

They had lots of mechanical disk scanners at the time. Most of the
from 1926 thru 1933 was an attempt by various inventors to duplicate
the mechanical scanning using electronics and tubes. They already had
the picture tube but lacked a suitable camera. What Farnsworth
contributed was the camera or "image disector tube" in 1927, which was
the first practical (and non-mechanical) camera tube.
http://www.earlytelevision.org/philofarnsworth.html
His big contribution to the technology was removing all the moving
parts from TV. (Of course CBS tried to put the mechanics back with
their giant rotating colour wheel monstrocity for color TV in 1950).
http://www.novia.net/~ereitan/Color_Sys_CBS.html
http://www.earlytelevision.org/cbscolorwheel.html
Zworkin managed to come up with the same scanning principle and ended
up paying Farnsworth royalties for the infringement.
http://inventors.about.com/library/inventors/blzworykin.htm
Note that Rosing and Zworkin had demonstrated a working CRT based TV
system in 1910. However, it used a mechanical mirror/drum scanning
"camera" of sorts that would only display geometric images.

Fell off my bookshelf: "Empire of the Air. The Men who Made Radio"
by Tom Lewis. Largely details the history and demise of RCA and
touches a bit on the politics of early TV.

 

[Clifton T. Sharp Jr.]

Fell off my bookshelf: "Empire of the Air. The Men who Made Radio"
by Tom Lewis. Largely details the history and demise of RCA and
touches a bit on the politics of early TV.

"The Farnsworth Chronicles" at
<http://park.org/Pavilions/WorldExpositions/PhiloFarnsworth/>
is great reading.

"Farnsworth was a 14 year old Mormon farm boy from Rigby Idaho with
virtually no knowledge of electronics when he first sketched his idea
for electronic video on a black board for his high-school science
teacher in 1922. 15 years later, that teacher would re-create that
sketch as part of his testimony in patent litigation between Farnsworth
and the giant Radio Corporation of America. Farnsworth eventually won
all of his extensive litigation with RCA, and became the first
Independent Inventor EVER awarded a royalty-paying patent license
from RCA."

 

[John Larkin]

They had lots of mechanical disk scanners at the time. Most of the
from 1926 thru 1933 was an attempt by various inventors to duplicate
the mechanical scanning using electronics and tubes. They already had
the picture tube but lacked a suitable camera. What Farnsworth
contributed was the camera or "image disector tube" in 1927, which was
the first practical (and non-mechanical) camera tube.

The image dissector has a serious disadvantage compared to the
iconoscope and later tubes: it threw away most of the signal, whereas
the later tubes integrated charge over the entire scan period.

Farnsworth did interesting stuff with secondary emission, but I don't
know if he invented it... does anybody know the history here? He did
discover the multipactor effect, a very interesting resonant secondary
emission phenom that has caused grief in some satellite RF systems.

He did a lot of his work in a little cottage at 202 Green Street here
in San Francisco. The cottage is still there, with a small plaque
identifying its history. Russell Varian, inventor of the klystron and
co-founder of Varian Associates, worked for him for a while.

Oh, incidentally, Nipkow patented a scanning television system in
1884, and Zworykin patented the precursor to the iconoscope camera
tube in 1923, when Farnsworth was still in high school.

John

 

[Tim Williams]

Give him a few more months and Tony Blair will have invented it.

Don't you mean Al Gore?

Tim

 

[Mike]

I stopped by Book Baron (www.bookbaron.com) yesterday and picked up a
$7 used paperback of The Last Lone Inventor (http://www.lastlone.com).
I've been reading a few chapters of the story of Television, Philo T.
Farnsworth and David Sarnoff, which everyone should read. Right now
you are probably watching a CRT which was invented by Farnsworth.
It's truly amazing. Little did he know how much his invention would
change the world.

Hmmm... I thumbed through that very copy at Book Baron a week or so ago. I
didn't buy that one, but I did buy "Discontinuous Automatic Control," by
Irmgard Flugge-Lotz (apparently the first full analysis of switched
feedback systems with restoring forces), and "Theory of Servomechanisms,"
one of the RadLab series, with a section by Hurewicz that was the first
exposition of what became the z transform. A few months ago, I found
Viterbi's book, "Principles of Coherent Communication," on their shelves.

BookBaron has their own web site (appropriately enough: www.bookbaron.com).
The web site is okay, but the stores in Anaheim and Long Beach are worth
going to just to browse for an afternoon.

-- Mike --

 

[John Larkin]

BookBaron has their own web site (appropriately enough: www.bookbaron.com).
The web site is okay, but the stores in Anaheim and Long Beach are worth
going to just to browse for an afternoon.

-- Mike --

In Portland, Powell's is worth an extra day.

John

 

[Hagstar]

Farnsworth eventually won
all of his extensive litigation with RCA, and became the first
Independent Inventor EVER awarded a royalty-paying patent license
from RCA.

Courts must have been very casual in those days, and I'm sure Sarnoff
had slackers for lawyers (look how Armstrong rolled right over him, for
example). That MUST be true, because look at all the smart people here
who have mentioned a dozen others who had a whole television system all
ready to go when "Farnsworth was still in high school". Yup, Vladdie and
Braun had electronic TV all bug free, but somehow this farm boy guy
hoodwinked the entire court system and ends up with RCA paying him. Dave
Sarnoff sure was loose with his money- and loved to honor patents, oh
yeah. Musta' had a soft spot for old Philo.....

John H.

 

[kenneth scharf]

The image dissector has a serious disadvantage compared to the
iconoscope and later tubes: it threw away most of the signal, whereas
the later tubes integrated charge over the entire scan period.

The image dissector is a little bit like a newtonian telescope in that the
collector is located in the light path partly blocking the target. I don't
know why a shadow isn't cast on the target. I think some image dissectors
were built in which the back side of the target has the image focused on it
and the image is read off the other side, these tubes would have looked
like normal crt's. Iconoscopes were built that way as well.

 

[[email protected]]

RCA battled long and hard, but Philo had some basic scanning principles
locked up and RCA eventually had to pay.

Mrs. Farnsworth writes that, at the meeting where the licensing agreement
was signed, RCA's lawyer had tears in his eyes as he inked the document.
(Probably knew he would be canned the next day.)

It was a pyrrhic victory, though, commercial television was put on hold
during WWII and, as the war ended, the patents were running out.

Philo never made what he should have from his invention.

Norm Lehfeldt

 

[[email protected]]

The lens focuses the image on the front of the target, a discrete electron
image is emitted by the rear of the target. It streams, in straight lines,
toward an aperture in a plate at the rear of the tube. The deflection coils
cause the entire electron image to be moved, so that only a small portion
of it (what we would now call a pixel, I guess) passes through the aperture
at any given time. You can see that not many electrons get through. This is
why the Dissector is relatively insensitive.

It did have better gray-scale and sharper focus than the first storage
tubes--so-called because electrons accumulate on the target between passes
of the scanning beam, so more of them are knocked off the target into the
amplifiers.

Zworykin's 1923 patent was purely speculative. No device constructed
according to its principles was ever demonstrated to work.

There is said to have been some kind of VZ demonstration in 1925. But it
was not documented and witnesses were always unclear on what they had seen.
One would think that, if the Zworkyin device worked, Sarnoff would have
made sure that it was properly recorded and trumpeted.

Philo's progress, on the other hand, was meticulously documented. No one
has ever proved that they had an entire, working electronic system before
that famous experiment on Green Street in 1927.

Norm Lehfeldt

 

[John Larkin]

The image dissector is a little bit like a newtonian telescope in that the
collector is located in the light path partly blocking the target. I don't
know why a shadow isn't cast on the target.

Actually, no. The optical image is focussed on a flat glass faceplate
which has a photocathode deposited on its back (vacuum) side. A single
photomultiplier is the pickup, way on the other side of the tube. A
sweeping magnetic field steers the electron image into the
photomultiplier, and at any instant most of the electrons miss. If the
image has effectively N pixels, only 1/N of the photoelectrons are
used - actually a bit less - and the rest are wasted.

John

 

[Alan R. Betz]

Actually, no. The optical image is focussed on a flat glass faceplate
which has a photocathode deposited on its back (vacuum) side. A single
photomultiplier is the pickup, way on the other side of the tube. A
sweeping magnetic field steers the electron image into the
photomultiplier, and at any instant most of the electrons miss. If the
image has effectively N pixels, only 1/N of the photoelectrons are
used - actually a bit less - and the rest are wasted.

John

The Farnsworth image dissector that I have (1948 vintage) requires
that a long focal length lens focuses its image on the photocathode at
the
REAR end of the tube. The electron multiplier structure is near the
front and offset to one side, but it DOES obstruct part of the image.
The clear faceplate has a wire grid attached to the inside and is
connected to the positive terminal of the accelerating voltage. It
collects all of the otherwise unused electrons.

 

[John Larkin]

The Farnsworth image dissector that I have (1948 vintage) requires
that a long focal length lens focuses its image on the photocathode at
the
REAR end of the tube. The electron multiplier structure is near the
front and offset to one side, but it DOES obstruct part of the image.
The clear faceplate has a wire grid attached to the inside and is
connected to the positive terminal of the accelerating voltage. It
collects all of the otherwise unused electrons.

Oh, I hadn't seen that one... interesting. I guess the obstruction is
out of focus enough that it doesn't cause a big problem.

John

 

[Mike]

In Portland, Powell's is worth an extra day.

John

I've shopped at Powell's (on-line, not in person). Bought my copy of
"Noise," by Van Der Ziel there. In Cleveland, there's Zubal books. I
haven't been there in person, but they claim to have 5 million volumes.

-- Mike --

 

[Tom Del Rosso]

It was a pyrrhic victory, though, commercial television was put on
hold during WWII and, as the war ended, the patents were running out.

But did he get back royalties?

 

[Clifton T. Sharp Jr.]

I thought it was the Russian born Vladimir Kosma Zworykin who developed
the first working camera and picture tube at Westinghouse or was it RCA?

From <http://park.org/Pavilions/WorldExpositions/PhiloFarnsworth/part6.html>:

"The competition began intensifying early in 1934, when RCA began
demonstrating their own new electronic television system which Zworykin
succeeded in producing three years after his visit to Farnsworth's lab.

"RCA's praise of Zworykin's contribution was extensive, although parts
of his camera device can be traced to work done in Europe by Kalman
Tihanyi, J.D. McGee and others. RCA went on to claim that this new
camera tube, dubbed the ''Iconoscope" was essentially the same device
that Zworykin tried to patent in 1923. RCA stood by this assertion
despite the fact that Zworykin worked with spinning discs and mirrors
all through the late 20's--right up until the time he visited 202 Green
Street."


All indications I've seen suggest that Zworykin "invented" television
by visiting Farnsworth's labs and finding out how Farnsworth's equipment
worked. He had a general idea of the general concept before that, but
nothing practical for implementation. Others before him had as much.
What Zworykin had that they didn't was David Sarnoff and RCA, who wanted
more than anything to own the patents that would control television.