TELEVISION SOLVED.

New Zealand Herald, Volume LXIII, Issue 19292, 3 April 1926, Page 2 (Supplement)

TELEVISION SOLVED.

SCOTS INVENTOR'S CLAIM.

PICTURES BY WIRELESS. demonstration given. Iwo more scientific marvels, rivalling wireless, are rapidly being developed. A means has been devised of recording and ieproducing sound simultaneously with pictures. In this way the human voice, speeches, music, operas, etc., can be rcpro' duced both for eye and ear. Still more wonderful, however, is the realisation that i before long, by means of wireless or telephone wires, we shall be able to see people as well as hear them. Mr. J. L. Baird, a young Scottish inventor, has achieved astonishing success in tackling the problem of television, or "seeing by wireless." After two-years' research work, he has perfected apparatus which will transmit and reproduce at the receiving end the features of a person at the sending station. A striking demonstration of the efficiency of the instrument was given by Mr. Baird before the Royal Institution. The head of a doll was placed before the transmitter, and was received in perfectly recognisable form, even to pink cheeks and blue eyes. Mr. Baird then placed his own head in front of the transmitter, and his full face, profile, and every movement could be seen distinctly—not merely in black and white effect, but with gradations of light and shade and full detaiL With or Without Wires. Mr. Baird is able to transmit on to a screen the features of any individual either by means of wires or by wireless on any desired wave-length. At present his apparatus is still in a laboratory stage, the sending machine consisting of a large wooden revolving disc containing lenses, behind which is a revolving shutter and a' light sensitive cell. By manipulating the shutter and lens disc, an image of articles or persons standing, in front of the machine is made to pass over the light sensitive cell at a high speed. The current in the cell varies in proportion to the light fnlling on it, and this variation is transmitted to a receiver where it controls a light behind an optical arrangement similar to that at the sending end. By this means a point of light is caused to traverse a ground glass screen. The light is dim at the shadows, and bright at the high lights, and crosses the screen so rapidly that the whole image appears simultaneously to the ej'e. A Defect Eemaining. Reception at the present stage is marred by dark lines, which are set up by the disc not being revolved at a sufficient speed. The disc is made of three-ply wood, and it is considered dangerous to work it at more than from 200 to 300 revolutions per minute. A steel disc could be turned at from 600 to 800 ( revolutions per minute, and would eliminate the dark bands. The television attempted by Mr. Baird should not be confused with the telegraphic transmission of photography, or telephotography. The projection of the image is carried out in stereoscopic fashion, and the transmission is instantaneous. A notable feature of the method" used is that distance should offer no barrier to reception, as the electrical impulses transmitted are precisely similar to those sent out when sound is broadcast, the transmitting televisor replacing the microphone. The Postmaster-General, it is announced, has been approached in the matter of granting television permits. Already 600 television receivers are being constructed, and a complete apparatus will cost anything from £SO to £SO.