TELEVISION

Wairarapa Times-Age, 27 April 1942, Page 4

TELEVISION

PROGRESS IN BRITAIN. PICTURES IN STEREOSCOPIC RELIEF. Mr John L. Baird, pioneer of television in Great Britain, has achieved a television picture in steroscopic relief. This he says, is the final step. Television had height and width, but depth was necessary to give the appearance of solid reality. A year ago Mr Baird displayed television in colour, and said a stereoscopic picture was the only thing left to give a true picture. This had been achieved in the laboratory and only requires development to make it a commercial proposition. At present, the picture can be seen on the screen only by a person directly in front of it. A very small 'deviation of the eyes to either side renders it invisible.

In the apparatus demonstrated, the frame frequency has been increased from one-fiftieth of a second to one one hundred and fiftieth of a second. Thus the scanning is altered to a field of 100 lines interlaced five times to give a 500-line picture, the successive 100-line frames being coloured red, green and blue.

At the transmitter, a cathode ray tube is used in conjunction with photoelectric cells to project the moving light spot on the scene to be transmitted. In front of the lens a device consisting of four mirrors set at right angles splits the emerging light beam into two paths separated by a space equal to that between the two eyes. A revolving shutter causes the scene to be scanned by each beam alternately, so that images corresponding to the right and left eye are transmitted in rapid sequence. The light beam passes through the shutter after passing through a rotating disc with red, blue and green filters. Thus superimposed, red, blue and green pictures blend to give a full colour picture for the right and left eye alternately. At the receiving end, the alternate halves of the projecting lens are exposed by a rotating shutter, the image of the shutter being projected on the viewer’s eye so the left and right eyes are presented alternately with the left and right images. The combined effect is a stereoscopic picture in full natural colour..