Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
128 words
A circuit for detecting odd and even fields of a video signal input, comprising: first counter means for counting a clock pulse input to detect a vertical synchronous pulse interval of the video signal; second counter means for counting the clock pulse upon detection of the vertical synchronous pulse interval to generate a window signal and a counting signal having a predetermined pulse width; and output means for, in response to horizontal synchronous pulses and the window signal, generating a first logic state remaining for a next vertical synchronous pulse interval, and for generating a second logic state remaining for the next vertical synchronous pulse interval; whereby the output means maintains the first logic state for the odd field and the second logic state for the even field.
Claim 2
Dependent Claim
128 words
A circuit for detecting odd and even fields of a video signal input, comprising: first counter means for counting a clock pulse input to detect a vertical synchronous pulse interval of the video signal; second counter means for counting the clock pulse upon detection of the vertical synchronous pulse interval to generate a window signal and a counting signal having a predetermined pulse width; and output means for, in response to horizontal synchronous pulses and the window signal, generating a first logic state remaining for a next vertical synchronous pulse interval, and for generating a second logic state remaining for the next vertical synchronous pulse interval; whereby the output means maintains the first logic state for the odd field and the second logic state for the even field.
Claim 3
Dependent Claim
79 words
The circuit as claimed in claim 1, wherein said first counter means comprises: a first AND gate for receiving composite synchronous pulses and a reset pulse; a synchronous counter, coupled to receive an output of said first AND gate, and for counting the clock pulse; a second AND gate for receiving the output of the synchronous counter to detect therefrom the vertical synchronous pulse interval; and a first JK flip-flop responsive to the output of the second AND gate.
Claim 4
Dependent Claim
92 words
The circuit as claimed in claim 1, wherein said second counter means comprises: first and second 4-bit synchronous counters connected in parallel to form an 8-bit counter, for counting the clock pulse upon receiving the output of a first JK flip-flop; an AND gate for receiving the output of the 8-bit synchronous center; an OR gate for receiving the output of the second 4-bit synchronous counter to generate the counting signal; and a second JK flip-flop for receiving the outputs of the second and third AND gates to generate the window signal.
Claim 5
Dependent Claim
55 words
The circuit as claimed in claim 1, wherein said output means comprises: a fourth AND gate for receiving the window signal and the vertical synchronous pulses to generate a subclock pulse; and a D flip-flop for receiving the counting signal to maintain the logic state of the counting signal in response to the subclock pulse.
Claim 6
Dependent Claim
93 words
The circuit as claimed in claim 2, wherein said second counter means comprises: first and second 4-bit synchronous counters connected in parallel to form a 8-bit counter, for counting the clock pulse upon receiving the output of the first JK flip-flop; a third AND gate for receiving the output of the 8-bit synchronous counter; an OR gate for receiving the output of the second 4-bit synchronous counter to generate the counting signal; and a second JK flip-flop for receiving the outputs of the second and third AND gates to generate the window signal.