Optische Anordnung zur Beseitigung der Zeilen-struktur bei Fernsehempfaengern

摘要

978,551. Television. SABA SCHWARZWALDER APPARATE - BAU ANSTALT AUGUST SCHWER SOHNE G.m.b.H. Dec. 21, 1960 [Dec. 21, 1959; March 31, 1960; Sept. 3, 1960; Oct. 12, 1960], No. 43942/60. Drawings to Specification. Heading H4F. [Also in Divisions G2 and H1] An optical device for eliminating the line structure of a television picture raster produced by a cathode-ray tube comprises a transparent member disposed between the view and fluorescent screen of the tube and formed with a plurality of grooves extending parallel to the line structure and spaced closer than the spacing between raster lines, the grooves being arranged that each spot of the picture is magnified so that the luminous densities of adjacent raster lines as magnified overlap. The device may be: (1) a separate plate adhered to the front face of the cathode-ray tube, e.g. by " Canada balsam," (2) a plate also functioning as a protective plate which is mounted in front of the cathode-ray tube, (3) the front face of the cathode-ray tube itself, or (4) in the form of spectacles to be worn by the viewer. Reference is made to the use of colour additives to improve contrast. Where the device is used close to the fluorescent screen, the grooves are given a spacing of 1/ 5 -1/ 20 of the raster line spacing and a depth of about 1/ 10 of the spacing. Grooves of 1/ 10 mm. spacing are mentioned in connection with a device for use with 17-inch- 24-inch cathode-ray tubes. The device may be formed of glass or plastic. The device may also be formed with grooves extending transverse the line direction so as to form a " lattice " plate, the vertical grooves having a depth different from that of the horizontal grooves. It is stated that the grooves may be of any configuration, description being given of arrangements formed with cylindrical surfaces, parabolic surfaces and sinusoidal surfaces composed of one, two or three sine waves of a different wavelength. The surfaces may also be given a random characteristic by cutting the grooves with sandpaper or by a tool controlled to effect variable depth and/or lateral position modulation of parabolic grooves in response to a noise signal. The device may be formed so that the grooved surface is formed at the boundary between two materials of different refractive index. In order to manufacture such a device, one material is selected to have a higher softening point than the other and is used as master pattern on which the other material is pressed or cast. Such arrangements are referred so in connection with spectacles. Specifications 744,648 and 886,439 are referred to.