1920s

1923 - VLADMIR  ZWORYKIN AND TELEVISION.  Vladmir Zworykin patented the television picture tube in 1923.  He also developed a cathode-ray tube receiver and built console television cabinets to house his test mechanisms.  In 1929, Zworykin broadcast the first electronic image through the air from the KDKA radio transmitter at the Westinghouse Recreation Center on Greensburg Pike, Pittsburgh, PA.  The images Zworykin sent were received on a cabinet television at his home in Swissvale, PA.  Zworykin called his picture tube the "Iconoscope."  This round tube contained the first photoelectric mosaic made from metal particles applied to both sides of a sheet of mica. The Iconoscope allowed pictures to be electronically broken down into hundreds of thousands of elements (picture elements, or pixels).   The electron beam received a photoelectric charge from the mosaic.  Zworykin presented the Iconoscope at New York in 1929 for an engineer's meeting.  It was built by RCA in 1933 and scanned 120 lines at 24 frames per second.  In 1924, Zworykin filed a patent application for his kinescope that later was to be called a television receiver, or just TV.
 

   Iconoscope Camera                  Vladmir Zworykin                  1929 Television

Additional information concerning Vladmir Zworykin and television can be found at:

http://www.northstar.k12.ak.us/schools/ryn/projects/inventors/index.html
http://www.cedmagic.com/history/
http://chem.ch.huji.ac.il/~eugeniik/history/zworykin.htm
http://share4.esd105.wednet.edu/wachtelg/development.htm

 
 

Visit http://www.aade.com/tubepedia/1collection/tubepedia.htm to view many unusal camera tubes (image pick-up tubes) and other interesting tubes used in early television broadcasting.

RADIO PHOTOGRAPH - 1924.  RCA transmitted the first radio photograph, a precursor to the facsimile machine, across the Atlantic Ocean.  http://www.rca.com/content/viewdetail/1,2811,EI98-CI263,00.html?

 
FIRST 35MM CAMERA - 1924.   Leica cameras began when Oskar Barnack developed the world's first 35mm camera, the Leica I. The Leica I camera was presented to the public for the first time at the 1924 spring fair in Leipzig, Germany.
http://www.leicacamera.com/unternehmen/international/usa/index_e.html

FIRST VIDEO PHONE- 1926.   Dr. Herbert Ives, an American, proposed in January of 1925 speeding up an AT&T facsimile system "to the point where the product would be television." By December 1925, he had devised an electromechanical system that could transmit images from one laboratory bench to the next. Dr. Frank Gray contributed a mechanical television camera based on the flying spot system, which illuminated the subject with a rapidly moving, narrow beam of light. Harry Stoller contributed a system for keeping the transmitter and receiver synchronized. Ives first demonstrated this apparatus to AT&T executives on March 10th, 1926. The executives talked to one another via "video telephone". The picture was low-definition with 50 lines of resolution at 16 frames per second, but the image of a human face was recognizable, seen via a 2-inch-by-2½-inch window.

http://www.bairdtelevision.com/Ives.html

KODAK CARTRIDGE HAWK-EYE NO. 2 MODEL C - 1926. Early model box cameras are plentiful and can often be pruchased in good to excellent condition at very modest prices. Every camera collection should have at least one box camera. The above camera was purchased for only $9.95.

KODAK 1A POCKET CAMERA - 1926-29 (Black model).   Eastman Kodak produced a number of variations of this very popular camera thereby helping to promote the photography hobby in the U.S. The folding Pocket No. 1 (2 1/4" x 3 1/4" on 120 film) and No. 1A (2 1/2" x 4 1/4" on #116 obsolete film) came in various series and types. These cameras were mass produced with inexpensive optics. F/6.3 - F/45, 127mm lens (not same on all cameras). Kodex No 1 shutter (T,B.25,50). T he 1A Pocket Kodak was constructed of leatherette covered metal. The entire camera back was removed in order to load the film. It is one of the first cameras to incorporate an adjustable range finder. As the bellows is withdrawn from the body it extends on a chrome rail until it meets a stop. The supporting rail is then moved forward and back by means of a small thumb screw located on the right side. Distances were shown on a small scale on the left side. The stop is adjustable in order to calibrate the rangefinder.

www.nwmangum.com/ Kodak/No1APK-1.html

www.clickondavid.com/ no1ap.html

FIRST TELEVISION TRANSMISSION IN THE U.S. - 1927.  On 8 April 1927, Bell Laboratories performed the first mechanical television transmission in the U.S.  For additional information see: http://www.mztv.com/how.html
 

THE FLASHBULB - 1927.  In 1927, General Electric invented the modern flashbulb.  In the early 1930's, flashbulbs replaced dangerous flash powder techniques of illumination.  The first commercially available bulb in the U.S., GE's Sashalite, was very large and contained aluminum foil surrounded by an oxygen atmosphere to increase burning of the foil.  The Sashalite had a tremendous light output, nearly 180,000 lumen-seconds, necessary for the rather slow speed films of the time.

                  Early Advertisement for G.E. Sashalite Photo Flash Bulb

        Flash Bulb Size Variation                 G.E. Mazda Photoflash Type 75
 
 

THE JOHN LOGIE BAIRD PHONODISC AND TV- 1928.  The first videodisc, the Phonodisc, was developed by Scottish inventor John Logie Baird.  It was a 250 mm, 78 rpm record, similar to the discs being produced for sound recording at that time.   A 30-line television signal was recorded on the Phonodisc.  The earliest known consumer recording of a TV broadcast (1933) was onto a Baird Phonodisc.  The Phonodisc was not a commercial success and was abandoned in 1936.

      Baird Silvatone Disc          John Logie Baird          Baird with Early Television Set

BAIRD TV - 1928.  John Logie Baird first publicly demonstrated television on 26 January 1926, in his small laboratory in the Soho district of London.  Although large companies with great financial support were also working on the problem of television, Baird managed to surpass them all with very little money, a handful of unpaid helpers, and equipment pieced together using rather unconventional materials.  For example, Baird's choice of mechanical scanning as the most effective way of achieving true television required the use of spinning discs - which of financial necessity were made of hatboxes and mounted on a coffin lid!  In 1928 Baird transmitted a facial image across the Atlantic Ocean. Additional information concerning John Logie Baird and his TV system can be found at:

http://www.tvdawn.com/tvhist1.htm#Lecture
http://www.dfm.dircon.co.uk/silvaton.HTM
http://www.gizmohighway.com/people/john_logie_baird.htm

1920s