Process for obtaining an increased light electrical effect in light electrical cellswith alkali metal cathodes and other cells of a similar nature

摘要

169,008. Larsen, A. Sinding-. June 15, 1920. Copying-telegraphs.-In apparatus employing photo-electric cells, current is supplied to the cell at a voltage high enough to maintain but not sufficient to start a discharge in the dark, the current being alternating or interrupted. In the application of the invention to the long-distance transmission of pictures, light from the picture is transmitted to the photo-electric cell C by way of the lens L, oscillating mirrors S', S2, and hole in the screen B. The supply of current to the cell C from the source E takes place through the rotating disc H and contact K1, the contact being preferably bad. The interrupter is also arranged to shut off intermittently the light from the hole in the screen B and to short circuit the electrodes of the cell during the periods of darkness. Impulses are received by an electromagnet M between the poles of which is a magnetized rod F whose natural period is the same as that of the current interruptions, and which interrupts light from the lamp N. The light then passes by way of the lens L2 and the oscillating mirrors S1, S2 in known manner to a screen. ,