TWO-WAY TELEVISION

Greymouth Evening Star, 26 July 1930, Page 3

TWO-WAY TELEVISION

COMPLEXITY AND HIGH COST

It is now technically possible for two persons who are thousands of miles apart to hold a telephone conversation, at the same time seeing each other, or at least moving images of each other in recognisable size and clearness. This invention, the latest advance in television, is, however, not yet in the commercial state, chiefly on account, of complexity and high cost.. Further improvements arc regarded as certain. Says the New York, “Times” in an account of a recent demonstration in that city: “Two-way television in which the speakers at both ends of a telephone line or radio circuit, see (he image of each other as they talk was demonstrated recently by the American Telephone and Telegraph Company. Distance is no obstacle to the new system. It is just as easy to let. a person in San Francisco see a person at the other end of the line in New York as it is to send the images over a short distance. The system is applicable to radio, but. with less certaintj' than when wires link the two points. Telephone wires were used in the demonstration.

“Special television booths have been developed about the same size as an ordinary telephone booth. Upon entering the booth the person to be “televised” sits in a swivel chair and faces a frame in which he will see the person at the other end of the line to whom he will speak. The face is illuminated by a mild glow of blue light, which is reflected from the face to the photoelectric cells known as ‘radio eyes.’ This causes the current to flow which transmits the image to the distant booth. There is no glare or flood of brilliant lights as in early television systems. At. first, as one enters the booth, one notices a dim ordnge light, which is too weak to affect the photelectric.cells. The usual telephone is missing. Special television transmitters and receivers are hidden from view. It was necessary to dispense with the ordinary ’phone, because it would hide part of the speaker’s face from the distant observer. “When the speaker turns in the chair and faces the apparatus he sees on the glass screen the words Ikonophone —watch this space for the television image.’ Then this sign lifts like a. magic curtain and in its place the animated picture appears of the person at the other terminal. The two converse in ordinary tone as over the telephone. The images are about a foot square and they are very clear. The 1930 television image is greatly improved over that shown by the’Bell Laboratories in 1927,-and it is double the size, with more clarity and detail. Both parties to the conversation see each other with sufficient detail to recognise facial expression. It is like an instantaneous motion picture in black and white, on a pinkish background, caused by the colour of tube utilised in the receiving set. No part of the system is annoying to the eye.”