发明名称 Time base corrector
摘要 A time base corrector for retiming the chrominance and luminance components of a non-phased television picture signal from a PAL video tape recorder to local reference syncs. The time base corrector comprises digital storage means and an analogue-to-digital converter connected to an input of the storage means. A digital-to-analogue converter is connected to the output of the storage means. "Read" clock pulse generating means are connected with the digital-to-analogue converter and the storage means to trigger the same. A first phase comparator means is operative to compare local horizontal reference signals with horizontal pulses from a divider connected to the "Read" clock pulse means for controlling the output frequency of the same. Horizontal synchronizing pulse addition means are connected with the output of the digital-to-analogue converter for receiving the analogue signal from the digital-to-analogue converter and imparting thereto a horizontal synchronizing pulse in exact time relationship with the line frequency. Heterodyning means are connected between the input to the corrector and the analogue-to-digital converter. A second phase comparator means is operative to compare the color burst output of the digital-to-analogue converter with a local sub carrier reference signal and to control the heterodyning means. The heterodyning means imparts to said analogue-to-digital converter a chrominace component signal having a frequency controlled with reference both to the off tape horizontal synchronizing pulses and to the required sub carrier reference frequency.
申请公布号 US3996605(A) 申请公布日期 1976.12.07
申请号 US19750582967 申请日期 1975.06.02
申请人 QUANTEL LIMITED 发明人 COFFEY, JOHN ALBERT
分类号 H04N9/896;H04N9/898;(IPC1-7):H04N9/02;H04N5/76 主分类号 H04N9/896
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