THE COMING OF TELEVISION HOW IT WORKS

Radio Record, Volume I, Issue 41, 27 April 1928, Page 15

THE COMING OF TELEVISION HOW IT WORKS

The miracle of sight by wireless has | been achieved. The famous Rell Telephone Company, which operates a huge network of thousands of miles of telephone lines in the United States, has one of the most remarkable research laboratories in the world. About a hundred of its men have been busy solving the problem of seeing by wircless. ‘the same Jaboratory has iustalled over a thousand instruments for telegraphing photographs, and so perfect are the results that it is almost impossible for an expert photographer to distinguish between the original picture and a copy of it sent 5000 miles by wire. tue Pencil of Ligiit. The Bell ‘Lelephone Company decided a few years ago to attack the gigantic problem of television, and they have now perfected a system by which it is possible tor the whole audience of a theatre to watch on a screcn about two fect square the movements or features of a person hnndreds of miles away. So complete bas been their work that in the view of experts there is no doubt that in a short time television will become as commen a ting as the telegraphed picture. This is the method by winch the jikeness of a face can be scen five bundred miles away. A uarrow pelrcil of fight is directed by means of a rapidly-moving piece of apparatus on to eaeh tiny part in succession of the face of the person whose mage is to be seen at the distant spot. As this pencil of light fails on cach little bit of the face it passes over dark hair, light skin, dark eyes, white tecth, and so on, and from these various perts of the face the light is reflected on to three giant photo-clectric cells, the biggest ever made. Lamp Like a Chessboara. These ceils getcrate an electne current which changes in strength with cach change of the light reflected from the face. The varying cleetric current is sent on a wireless carrier wave to the distant station. ere it is picked up and passed into a remarkable kind of electric latip, consisting of a huge grid about two feet square, which can be illuminated in anv one of its 2500 tiny perts. It is like a large chessboard; and as the penvil of light at the sending instrument is focussed on each bit of the ‘face so the electric current received by wireless from the photo-clectric cell causes the corresponding titty portion of this neon Jamp grid to glow with corresponding brightuess. i8 Times a Second. The point of this pencil of light traces over the whole of the face in a fraction of a second, repeating its performance 18 times in a second. The result is that those watching the grid of the neon lamp see what amounts to a kinematograph picture of the sitter, whose face can be clearly scen many iniles away. Although at present only simple subjects, such as the head or shoulders, can be seen by wireless, so complete has been the work of the Bell ‘Telephone Company that it can be a matter of time only before television becomes common and far more elaborate subjects are dealt with.