发明名称 DERIVING FRAME INTERVAL SIGNALS
摘要 14 Deriving frame internal signals. Serial data from a C-MAC, D-MAC or D2-MAC television signal is applied over line (1) to a serial data to error conversion unit (2) which produces a 3-bit error signal when the applied data is compared with a W1 sync. word. The error signal is applied to comparators (6 and 7) whose other inputs receive a maximum or minimum error dependent signal to produce an output when the number of errors lies within certain requirements. These outputs are latched in a 2-bit latch (8) to produce line pulses on receipt of an acceptable sync word at an appropriate time, the outputs of the latch (8) being applied to two shift registers (9 and 10). The shift registers (9 and 10) produce outputs P1, P2, P3 and P4 over four line periods with the P3, P4 outputs of shift register (10) and the P1, P2 outputs of shift register (9) being applied to respective inputs of a first AND-gate (11) whilst the remaining outputs are applied to respective inputs of a second AND-gate (12) which gates produce an output when there is coincidence alternately at the end of each frame period. The outputs are applied to respective inputs of an OR-gate (13) to derive a frame flywheel and sync. acquisition unit (14) at frame frequency.
申请公布号 CA1260135(A) 申请公布日期 1989.09.26
申请号 CA19860507483 申请日期 1986.04.24
申请人 N.V.PHILIPS'GLOEILAMPENFABRIEKEN 发明人 KIRKLAND, ROBERT N.
分类号 H04N7/00;H04N7/083;H04N7/20 主分类号 H04N7/00
代理机构 代理人
主权项
地址