Television via a disc: how a metal disc, light and wires led to television

The history of television is one of my favorite subjects.  I have written several posts on this blog about mechanical television and color television.  I thought it might be interesting to go back even more, to the very beginning of television. 

Television, as we know it today, pretty much began in 1946 with the DuMont Network in the United States.  The late 1940’s and early 1950’s saw the rise of state and commercial television around the planet.  I’m not considering anything prior to 1946 as the start of television as we know it because it was still mostly experimental.  Indeed, the BBC had television service going back to the 1920’s.   NBC and RCA had a ‘network’ of transmitters in the 1930’s, but, again, it was experimental.  But, this is not the subject of this post.  No, I want to go back even further than John Logie Baird’s mechanical sets and Philo Farnsworth’s electronic sets. 

pantelograph The earliest recorded mentions of distance vision-the pre-television term-go back to the 1800’s.  Indeed, the earliest known transmission, over wires, of a picture occurred in 1862.  Abbe Giovanna Caselli invented a device called the pantelegraph.  The pantelegraph transmits still images over wires. The device, something akin to the modern fax machine, used a special ink on an electroplated object-a document-and transmitted it over telegraph wires. The device was pendulum, which from the point of origin read the electroplated document with a stylus on each swing.  The receiver, a duplicate device with a printing device to reproduce the image.  Both pendulums had to be in sync or it would not work.  The synchronization was accomplished by an electrical pulse that adjusted by electromagnets at both ends.  The device was employed by the French government in 1865 and discontinued in 1870.  While the images were still, this device is the very crude beginning of television: it employed a scanning device on the transmitting side and a similar device on the receiving side that reproduced the image.  Remarkable, considering the technology employed.  There were other devices invented during the period, but this one was the first that was employed commercially.  It is actually a modified version of a similar device that was invented nearly twenty years prior, in 1843 by Alexander Bain.  For more on the early fax machines, you can go here.  It’s pretty fascinating stuff and is all a precursor to television.

The 1870’s saw many discoveries and advancements that would lead to television.  Many famous people, such as Thomas Edison and Alexander Graham Bell, had grandiose visions of developing practical ‘distance vision’.  The term ‘television’ was not coined for another thirty years.  Bell proposed the photophone, a device that used light to transmit sound, be used to transmit images.  A scientist named George Carey built a simple system that used light-sensitive cells.  Sheldon Bidwell experimented with the photophone.  The real advancement, however, came in 1884.

1884 was the year that Paul Nipkow sent images over wires with his rotating disk.  nipkow_disk The disk contained a spiral pattern of holes, with each hole containing a lens.  As the disc spun, light would pass through the holes, striking one of the light-sensitive cells that Carey had performed his experiments.  The cells would send out an electrical pulse. On the receiving end, another disc, spinning in sync, would have a light that flickered in sync with the electrical pulse.  As the light flickered through holes, an image would form on a screen on the other side of the disk.  A crude, 18 line picture at that. But, it worked. He called the device an ‘electric telescope.’

The term ‘television’ was first used in the year 1900 by a Russian scientist named Constantin Perskyi.  Huh…I guess the Russians really did invent television.

In 1906, American Lee DeForest invented the Audion tube, which was an amplifier tube, it would become a key component in television development.  Also in 1906, another Russian was experimenting with a television system that combined the Nipkow disc and the cathode ray tube.  The system would use a mechanical camera to scan the image.  The CRT would then display the scanned image.  Boris Rosing filed a patent for his system-in Germany-in 1907.  He also patented an improved system in 1911.  That system was demonstrated the same year.  Sadly, Mr. Rosing was died of a brain hemorrhage in 1933. He had been exiled two years earlier.

Another more widely known Russian, Vladimir Zworykin, invented tube called the iconoscope.  The iconoscope was the electronic equivalent of the Nipkow disc.  While no moving parts were involved, the principle is similar.  Zworykin had emigrated to the United States and went to work for RCA, where he led the development of RCA’s all electronic television.

baird Mechanical television development continued into the 1930’s.  John Logie Baird of Scotland, and Charles Jenkins of the United States, each independently developed mechanical television systems. Baird was first to transmit moving images using the mechanical system.  This happened in 1925.  The following year, Baird achieved a resolution of thirty lines at five frames per second-hardly the high definition we enjoy today.

Color television remained elusive until the 1950’s.  Zworykin patented a color television system in 1925, but it never worked well.  Other color television systems were developed-as early as 1904-but none were successful.  John Logie Baird, however, did have a real, working color television system, but it was all mechanical.  While Baird eventually gave up on his mechanical television, his color system did not die.  CBS television used Baird’s system as the basis for its color standard.  That standard became THE standard in October of 1950.  The system employed a color wheel that synced to a signal that was broadcast over the air. The system worked very well, but it was not compatible with the black and white standard of the day.  Resolution was also less: 405 lines versus the 525 line system in use at the time.  The standard was short lived and, eventually, a modified version of the RCA standard was used.

No history of television would be complete without mention of Philo Farnsworth.  Farnsworth held many patents on electronic television in the United States.  He fought the behemoth named RCA and won.  Sadly, his contributions to television are often overlooked due to exaggerated histories put forth by RCA, Zworykin and others.  Also, I would be remiss if I did not acknowledge that television development was taking place all over the planet at the same time.  Japan, Germany and Russia, in addition the United States and Great Britain, were all developing television.  Germany was probably further along in the late 1930’s.  The German government employed public television to spread it’s word.  They used projection television so that many citizens could view the pictures.  Like the development of the computer, many of the early contributors are often overlooked.  Television is no different.  There were many Japanese scientists, German inventors and Russian scientists who contributed greatly to the advancement of television. 

I can only imagine the excitement that Caselli or Nipkow must have felt.  That they were able to do as much as they did during what was, essentially, the caveman era of technology is remarkable.  Imagine an image that was broken down, mechanically, sent over a distance and reassembled by another mechanical means…in the 1800’s..amazing.  Just amazing.

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