Frequency discriminating circuit
AssigneeSony Corporation
InventorsTetsuya Suzuki, Hideo Hatada
Life of this patent
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Abstract
A frequency discriminating circuit suitable for use with a display capable of displaying image data of a plurality of signal formats and which has an oscillator for generating an oscillation frequency corresponding to a horizontal synchronizing frequency of an input signal which can be displayed. This frequency discriminating circuit includes a counter for frequency-dividing the oscillation frequency of the oscillator which is reset by a horizontal synchronizing signal, to thereby discriminate the horizontal synchronizing frequency of the input signal.
Claims4
A frequency discriminating circuit suitable for use with a display capable of displaying a plurality of signal formats respectively employing horizontal synchronizing signals of different frequencies, the frequency discriminating circuit comprising:
- an oscillator having an oscillation frequency higher than the frequencies of said horizontal synchronizing signals;
- a counter for frequency-dividing the oscillation frequency of said oscillator to produce a frequency-divided signal;
- and
- a terminal to which a selected one of said horizontal synchronizing signals is applied, in which said counter is reset by said selected horizontal synchronizing signal;
- said frequency-divided signal having a frequency intermediate the frequencies of said horizontal synchronizing signals to thereby discriminate between said horizontal synchronizing signals.
Dependencies are inferred from the claim text.