In early 1907, M. Dickman designed, manufactured and conducted laboratory studies of semi-electronic TV. The transmitter was an electromechanical system in which contact scanning of flat metal stencils in the form of letters, numbers and other geometric shapes intended for transmission was carried out. For this purpose, a metal Nipkov disk was used, which made 10 revolutions per second. On the disk were fixed 20 spirally arranged contact brushes (in place of the holes of the disk).
The stencil was installed parallel to the disk, during the rotation of which the brushes slid on the stencil and provided a galvanic connection with it, creating a video signal. Thus, contact scanning of stencils was carried out, the image of which was transmitted. The receiver was a Brown tube with a 3×3 inch screen, the scan, respectively, was 10 frames per second vertically and 20 lines horizontally. With the help of this semi-electronic TV, still images were transmitted.
There was no public demonstration of the developed TV, because at that time in the scientific circles of Germany television was associated with a successful focus or perpetual motion machine, that is, beyond all scientific laws. Ferdinand Braun was categorically against the use of his oscillographic tube “not for its intended purpose”, that is, “science only for the sake of science”. Even in 1913, when M. Dickman tried to read a report on his achievements on television, the University Senate did not give consent.
On September 31, 1910, scientist Borys Rozing received a patent № 18076 with priority from July 25, 1907 for “Method of electrical transmission of images at a distance”. According to the patent, the transmitter used an electromechanical scheme of contactless image scanning using a system of moving mirrors. To create a video signal, a highly sensitive photocell developed by the author was used. A Brown tube modified by the author was used in the receiver, and signals formed synchronously and in-phase with the movement of mirrors in the transmitter were used for scanning.
On May 9, 1911, at a meeting of the scientific society, B. Rozing demonstrated a classical system of semi-electronic TV and transmitted an image of four white stripes on a black background. The number of lines is 12. The connection of the transmitter with the receiver was wired. Due to the inertia of the electromechanical transmission path, it was possible to transmit only still images. In the scientific laboratory of B. Rozing worked his student and assistant, V. Zvorykin, who was interested in the development of TV systems, and Rozing, as a true scientist, did not hide anything from his student. In 1919, V. Zvorykin emigrated to America, where he continued to work on television, and B. Rozing was fabricated a court case by the Bolshevik regime and died in exile.
Subsequently, a number of researchers offered their own TV systems that used moving mirrors and other methods for scanning in the transmission path: 1917 American R. Nicholson, 1922 Frenchman J. Valancy, 1924 German M. Dickman, 1929 American V. Zvorykin and others.
