| 摘要 |
456,810. Recording sound. EGYESULT IZZOLAMPA ES VILLAMOSSAGI RESZVENYTARSASAG, Ujpest, near Budapest. March 23, 1936, No. 8605. Convention date, March 22, 1935. Addition to 449,824. [Class 40 (ii)] [See also Group XL] Sounds are recorded by controlling a beam of ions to produce electric charges on an insulating surface which is then dusted with powder to render the record visible. The insulating surface.is given a uniform positive charge. The source of ions comprises an incandescent filament coated with emissive material and co-operates with a control electrode to which the control potentials are applied and consisting of a bad conductor 57, e.g. silicon carbide, biassed by a source 59 applied between electrodes 58, 58<1> so that a drop in potential occurs along the electrode. The aperture may be of varying cross-section, Fig. 17 (not shown). |
