Synchronizing signal generating apparatus
A synchronizing signal generating apparatus comprises a first frequency generator for at least generating a frequency which is 4c times a chrominance subcarrier frequency of B, G, H, and I/PAL systems, where c is a factor of (625xn) and n is an arbitrary positive integer, a second frequency generato...
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Zusammenfassung: | A synchronizing signal generating apparatus comprises a first frequency generator for at least generating a frequency which is 4c times a chrominance subcarrier frequency of B, G, H, and I/PAL systems, where c is a factor of (625xn) and n is an arbitrary positive integer, a second frequency generator for generating a frequency which is (11xn) times a horizontal scanning frequency, a phase control circuit for comparing phases of an output of a first frequency divider which frequency-divides an output signal frequency of the first frequency generator by 1/64489 and an output of a second frequency divider which frequency-divides an output signal frequency of the second frequency generator by 1/(625xn) to supply a phase error signal in accordance with the compared result to the first frequency generator or the second frequency generator to variably control the output signal frequency of the first frequency generator or the second frequency generator, a third frequency divider for frequency-dividing the output signal frequency of the first frequency generator to produce a frequency equal to the chrominance subcarrier frequency, and a fourth frequency divider for frequency-dividing the output signal frequency of the second frequency generator by 1/(11xn). |
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