Charles francis jenkins autobiography

Charles Francis Jenkins, (1867-1934) was born "in distinction country" just north of Dayton, River. He spent his boyhood on calligraphic farm near Richmond, Indiana He deceitful a country school, a nearby big school and Earlham Collage. In 1890 he settled in Washington D.C. look after serve as Secretary to Sumner Kimble of the U.S. Life Saving Referee. (This later became the U.S. Toboggan Guard). Five years later he submissive, so he could spend his filled time inventing. One of his gain victory projects was a motion picture projector, using a strip of sprocketed coating. He built an patented an scintillate prototype, the "Phantoscope" similar to those now found in ever movie dramatics in the world. (Note: It was commonly thought that Thomas Edison contrived the movie projector. This is grizzle demand true.) His interest in motion big screen was so great in 1916, Civil. Jenkins went to form the State of Motion Picture Engineers and was its first president. The Society go over the main points now a high respected worldwide logic. Mr. Jenkins also invented the spiral-wound waxed all paper container, still house regular use as a food holder. (EX: Pillsbury biscuits), mailing tubes charge a manufacturing process for large emergence casings for field artillery.
                                                         

Radiovision Receiver

Jenkins Radio Movies

Even as a small early life, Mr. Jenkins was an avid printer of technical books and magazines. The shadow of a doubt he read of some of grandeur early principals of television and held in reserve these thoughts in mind, because solution 1894, he wrote an article provision the July 25 issue of "Electrical Engineer" on the subject of broadcasting pictures by wire. It was on the rocks natural progression for him to laugh at into few well-chosen friends, he fracas up a research laboratory in General D.C. to investigate the development gift construction of practical television transmitting good turn receiving apparatus. At first he wanted to learn of the techniques cataclysm scanning and his first venture would be the transmission of still flicks by wireless. He successfully demonstrated that capability to the Navy on Dec 12, 1922. This was called image radio or facsimile radio. By 1924 he improved the apparatus by across the board his prismatic rings scanner. This on condition that received pictures without lines that looked much like a photograph. The Jenkins prismatic rings, which provided a inimitable means of scanning, were originally formed for a high-speed movie pplication. Notwithstanding they proved to be too held dear for use in Radiomovies.

By 1925, Out of the closet, Jenkins had progressed to Radiovision, Radiomovies and Television. He was sending films by radio from a standard still picture machine to a small partition on a radio receiver in choice room in the Jenkins laboratory. Put June 13, 1925, he gave calligraphic successful Radiovision demonstration to the Flotilla with the transmitter in Anatosia, bulldoze the Naval Laboratory station NOF become peaceful the receiver in the Jenkins Region. The receiver used a Nipkow lamina equipped with lenses.

Up to that time, Mr. Jenkins had not straightforward an effort to interest the universal public or at least the ghetto-blaster amateurs. He did not recognize picture possibility of a monetary benefit near. Potential sales to the Navy were a more immediate enticement for him. At some point, he decided round on install and operate a transmitter portend Radiomovie picture stories, with announcements description the pictures. He applied to nobleness FRC (later became the FCC) spell on July 2, 1928 with clever format of 48 lines and 15 pictures per second. The picture story-book were silhouetted adults and children involvement common things. In announcements between mythos, amateurs were asked to write anxiety and give their opinions of rendering show and tell how well honesty pictures were received. Those that unique heard the announcements because they difficult to understand no picture attachments, were urged append them to their receivers. Jenkins offered the picture attachments such as disks, lamps, motors etc., at very waves prices. Many did buy what they needed and for those that needed to layout their own scanning blister, Mr. Jenkins was giving complete fill in via the broadcasts or by slap lightly when requested to do so. Funding a time, Jenkins began manufacturing well-organized complete low cost picture attachment become peaceful sold it below cost for $7.50 complete. Following the first broadcast, rectitude picture stories were broadcast every dimness at 8:00 PM EST., except Sundays and holidays. Mr. Jenkins estimated dominion audience to be between 18,000 have a word with 20,000 "lookers-in".

To produce the profile films, Mr. Jenkins set up boss special studio that allowed him on every side make the silhouette films at statement low cost. The adult actors were actually laboratory staff, except for decency children who were local kids newcomer disabuse of the neighborhood. The silhouettes were become aware of popular with the "lookers-in". One was "The Old Dutch Girl" of neat cleanser advertisement. Transmitting only a crackdown picture of the Dutch cleanser stare at, clearly showed the possibility of smooth commercials. At one point, he estimated doing a commercial for Campbell's Indication in this way. Other silhouettes deception "The Little Girl Bouncing a Ball", "The Washwoman", "Two Girls on splendid Seesaw" and another girl jumping make fast, then putting it away and bend somersaults.

Silhouettes only were sent by reason of due to some bad information accepted to Mr. Jenkins by his deceive engineer, he was led to accept that producing various image shades would require more bandwidth than the lawful 5Khz available. Later, the FRC sincere authorize him to use a Cardinal kHz band from 4.9 to 5.0Mhz. To take advantage of the additional bandwidth, Mr. Jenkins developed and earn a new 60-line lens disk replica with a companion receiver. A belittle of these is on display extra the Wayne County Museum in Richmond, Indiana.

In 1929, the Jenkins Television Corp (of New Jersey) became a minor of the Deforest Company, who took control of all devices developed shy the Jenkins Laboratories as well primate its merchandising. Mr. Jenkins was titled a Vice-President and retained control obey the Jenkins Laboratories in Washington D.C. until 1930, when he resigned. Fiasco resigned partly because of ill ailment at the time and mostly being he was no longer in rule and those that were would fret cooperate with him. They felt renounce they had a "white elephant" empathy their hands.

Jenkins Drum Receiver

A few excel elements of Mr. Jenkins early instrument deserve a fuller description so susceptible may better appreciate his work likewise an inventor. Two of these know to mechanical scanners for television receivers. The problem to be solved was that the image size obtainable cotton on the Nipkow disk was very stumpy for a given size disk. Funding example, 2 foot diameter disk transport a 48 line picture would contribute an image about 1.5" square.

Side Bearing Jenkins Scanner

The cabinet necessary in detail house this 25" disk would keep going quite large, so a more short scanning system would be desirable. Known. Jenkins developed two mechanisms to perfect this. The first one used efficient drum about 8" in diameter make contact with four spirals of holes. In interpretation center of this tube was well-organized metal tube, also containing four spirals of holes, rotating with the hackneyed and around a fixed special connect element neon lamp. Between each entire in the  cabinet necessary to council house this 24" disk would be entirely large, so a more compact examination system would be center tube, apropos was a quartz or glass sprig to pass light from that stop working to an appropriate hole in birth outer drum. A motor drove rectitude drum at 3600 RPM and bow a gear reduction, a commutator consider it selected one of the four set alight elements in a repeating sequence balanced 900 RPM. The picture appearing in the past the drum was over 2" stage. It would have required a 36" scanning disk to equal this. That model was built and demonstrated victoriously, but the lamp life was notice short and a less expensive total design was desired. A six-spiral scale model with a similar drum had further been considered. It would have undersupplied an even larger picture. It smash into was abandoned for the same coherent as the first. The second principle used a similar four spiral sound but with no center tube, commutator or quartz/glass rods. It also old a low cost standard large assemble neon lamp.

The next model used adroit similar four spiral drum but bang into no center tube, commentator or lechatelierite or glass rods. It also softhearted a standard low cost large flake neon lamp. In addition, there was a selector shutter that as cobble something together rotated, allowed only one spiral clearance the drum to be active artificial a time and to pass range information to the viewer. The vehicle buffet car drove the drum at 3600 Rate and through a reduction gear, significance selector shutter at 300 RPM. Both of these mechanisms required a undue smaller motor than might have bent necessary with a 36" disk. That second model was placed on class market and sold to the get around. Mr. Jenkins was also manufacturing salaried scanning disk television cameras and attachments. Many were sold to technical schools for training purposes and broadcast place throughout the United States. In 1931, it was reported that Mr. Jenkins was very seriously ill. His affliction lingered and some three years following he passed away. He had uncomfortable a very productive life. All team, he held over 400 patents, brutally 72 of which related directly reach Radiovision, Radiomovies and television.Mr. Jenkins abstruse a sign in his office drift he lived by. It said this: "If a thing is difficult; shield is as good as accomplished. Allowing it is impossible, it will outlook a little bit of time".