TELEVISION IN COLOUR SOON

Manawatu Times, Volume 63, Issue 48, 26 February 1938, Page 12

TELEVISION IN COLOUR SOON

Delicate Apparatus

JN A FEW MONTHS television in colour is to be shown in London. The system is the invention of Mr. J. L. Baird, who told the television correspondent of the London Observer that it is already out of the laboratory stage. Coloured pictures are being sent out almost daily from the South Tower at the Crystal Palace, and are being picked up by the receivers in the Dominion Theatre.

This is not the first attempt that Mr. Baird has made on the problems that must be solved before television is complete. As long ago as 1928 he showed colour television in London and at the Glasgow meeting of the British Association. The old thirty-line, low definition system was used, and the pictures were crude and very flickery; but the colours were vivid.

“We should laugh at those pictures if we saw them now,” said Mr. Baird. “We thought them very wonderful, then. Yes, I was definitely the first to show television in colour.”

The apparatus that Mr. Baird is now using is mechanical as opposed to the electronic methods used in the 8.8. C. transmitter. His system is a development from his original experimental work done nearly ten years ago. “It Is something like the three-colour method of printing,” Mr. Baird told me. “I am using blue, green and red, and the picture on the receiver screen is traced out in alternating lines of these three colours. There are 120 lines to a picture, which just brings it within the high definition category. When the results of these experiments are shown to the public a big screen will be used.” Asked as to the possibility of putting colour into the ordinary home screen, Mr. Baird would say nothing definite, except that this is a development which must come. He thought that ; t would

be many years before monochromati# reception was replaced by colour in th# cathode ray tube methods of transmission now in use.

“We are actually experimenting In this direction now,” he told me. “You see, what we are doing with mechanical scanning is only a step towards other methods. No, I am afraid that J cannot tell you how I expect this fresh wonder is to be achieved, but ” Mr. Baird outlined the difficulties that have been already overcome in th# mechanical system that is soon to be demonstrated.

1 gathered that one of these difficulties was to transmit the coloured pictures on one wireless carrier wave. This has been done. The transmitted signal and the impulses which lock the picture in position on the receiving screen sirs sent out on one channel, and only one tuning is necessary to receive them all* just as in an ordinary broadcast or television receiver. As in a home television receiver, the sound part of the programme is sent out on a separate channel.

The Baird system uses three separate light sources, and three differently coloured lights are necessary in the receiver. These lights must only be in operation when the lir- they are illuminating on the picture is being transmitted. Very delicate triggering apparatus is necessary to ensure this.

The cathode ray tube, such as is used in the home receiver, is now only responsive to one colour. The screen might be made in the form of a mosaio of particles, each responsive to a particular colour. This is not very difficult; but. there are other very great problems to be solved before our home screens show a coloured in place of a black and white picture^