Farnsworth accomplished much in his lifetime, despite seemingly endless fights in patent court. (In his lifetime, he was granted around 165 patents.) The whole story is beyond the scope of this article (but is readily available). Here, I will focus on a few interesting points.
A stack of popular science magazines in the attic of their new home helped Philo learn more about electricity and electro-mechanical devices. Primitive “tele-vision” – distant transmission/viewing of images – was one of the fascinating topics of the day.
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| Farnsworth, right, with his former high school teacher. Philo T. Farnsworth Archives. |
By the time he entered Rigby High School, Philo had already exhibited a firm grasp of practical physics, especially electrical phenomena. As the story goes, he devised a better way to record images for transmission while plowing a field in regular back-and-forth rows (lines). However, the complete account involves rather more than that simple idea.
His science teacher at Rigby High School, Justin Tolman, soon recognized the young man’s aptitude and encouraged his pursuit of knowledge. It was he who first learned of Philo’s new approach.
Back then, typical television “cameras” employed a mechanically rotating disk to focus snippets of an image onto a photocell, which converts photons (light) into flowing electrons … electricity. Without going into all the physics, the electrical response shows how bright the light is. The electrical signal is then transmitted through some distance to a display system. Since Philo’s innovation involved the recorder, not the display, we’ll simply take the viewer as a given.
By the time Philo was ready to reduce his ideas to practice, around 1926, mechanical television systems had been demonstrated in this country and in England. But mechanical cameras are bulky and require a high degree of precision in their manufacture. In operation, they tend to be noisy, and dust, wear, or mechanical malfunctions hopelessly cripple the synchronization between recorder and display.
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| Farnsworth’s conceptual sketch. Philo T. Farnsworth Archives. |
Farnsworth’s accomplishment was to devise a way to electronically record the picture. His innovation combined several crucial features. Instead of directing snippets of light onto a small photocell, the camera captured the entire picture on a plate coated with photosensitive material. He placed this photosensor inside a vacuum-sealed cylinder, so the electrons generated flew off (were emitted) into empty space.
Philo's device then focused the electrons emitted from a small region – we now call it a pixel – onto an electrode that measured the electrical signal. A simple controller selected pixels one after another to form a line of dots crossing the photosensor horizontally. As in the plowed-field analogy, a series of parallel dot-lines growing from top to bottom covered the entire screen.
Because the device operated electromagnetically – no moving parts at all – the entire picture could be recorded many times each second … and practical “electronic” television was born. In 1927, Farnsworth filed for a patent on his device, and then demonstrated it publicly for the first time.
Ideas similar to Farnsworth’s design had been considered by others, but he was the one who put all the pieces together, and made it work. He passed away in March 1971. Today, the city of Rigby bills itself as the “birthplace of television,” and sponsors the Farnsworth TV & Pioneer Museum.
| References: [Brit] |
| Richard J. Beck, Famous Idahoans, Williams Printing, (© Richard J. Beck, 1989). |
| Donald G. Godfrey, Philo T. Farnsworth: the Father of Television, University of Utah Press (2001). |
A great article that gets it right, with no reservations! (for once!)
ReplyDeleteThank you. (I note that Philo was your Great Uncle, making your comment particularly gratifying.)
ReplyDeleteAccounts that focus just on the field plowing bit always annoyed me -- in my mind that basically trivializes his accomplishment. I did some extra research to better understand the technical context OF HIS TIME to see what he had to work with. (I have a physical science degree.) Paring that down to the fundamentals, without getting too long or too "techie," took some work. I'm glad you think I succeeded.
Yes, (Sorry to take so long getting back) Uncle Philo, as he was simply known around my house, was my grandmother's brother. I'm aware of the way he dropped to "Phil" in the Navy, and that's what Pem (his wife and our Auntie) called him, but Grandma always talked about him as Philo so that's how we knew him.
ReplyDeleteI thought you did a great job of describing the process without losing anybody, but more important I thought you "got it right" because you didn't hold back on where the credit lies. So many articles of this kind come through as puff pieces that are willing to say something nice about him nowadays, but still launch into "but lets not forget the many contributions . . ." yada yada yada.
As you so rightly pointed out, there were many scientists working along the same lines as Philo, all over the world in fact. That's how he was inspired to start. (Those science magazines, again.) But the great and extraordinary difference between him and them--the important and same spark that put him in a class with Bell and Edison--was that he saw how to make it work.
Unfortunately, he did not have the business genius of Bell and Edison, or we would today be talking about Farnsworth Television in the way we still speak of AT&T and Edison Power.
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ReplyDeleteFascinating story about an amazing and gifted man whose inventions contributed greatly to the development of television.
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