PROCESS OF TRANSMISSION AND RECEPTION OF WIDE-SCREEN TV IMAGE Russian patent published in 1997 - IPC

FIELD: television. SUBSTANCE: in compliance with proposed process of transmission and reception of wide-screen color image (system SECAM-plus) there are conducted two decreasing conversions of line standard of initial wide-format image at transmission side. One of conversions decreases number of lines to 3/4 of initial one. Produced basic signal is coded by SECAM standard and forms on screens of traditional TV receivers SECAM wide-format color image with decreased number of active lines. Second conversion forms auxiliary signal carrying information on high-frequency vertical components of initial image and carrying 1/4 of initial number of lines. Auxiliary signal modulates color SECAM subcarriers by amplitude and is transmitted in upper and lower parts of raster. This signal is not reconstructed on screen of standard SECAM TV receiver (in brightness channel color subcarriers are suppressed by rejection filter, in chromaticity channel amplitude modulation is cut by limiters and as subcarriers are not modulated by frequency no parasitic coloration is obtained). Sections of raster where auxiliary signal is transmitted have appearance of black stripes. Auxiliary signal does not create interference on the screen of black-and-white TV receiver owing to commutation of phase of subcarriers. In special wide-format SECAM-plus TV receiver basic and auxiliary signals are demodulated and increasing conversion of line standard takes place. After this - auxiliary signal is matched with brightness component of basic one. As result of it wide-format color image with complete vertical definition is generated on screen of TV receiver. EFFECT: enhanced reliability and stability of process. 2 cl, 4 dwg