H - Electricity – 04 – N
Patent
H - Electricity
04
N
352/18.4
H04N 5/92 (2006.01) H03C 3/09 (2006.01)
Patent
CA 2038425
An FM modulator includes a base clock generating circuit (7) receiving an incoming video signal for generating an AFC reference frequency signal having a frequency corresponding to tip of a horizontal synchronizing signal of negative polarity of the incoming video signal and phase synchronized with the incoming horizontal synchronizing signal, a first carrier reset pulse having the same frequency as that of the horizontal synchronizing signal and a second carrier reset pulse whose frequency is an integer multiple of that of the horizontal synchronizing signal. The first carrier reset pulse is generated to have a negative polarity in a prescribed period at a leading edge portion of the horizontal synchronizing signal. The second reset pulse is generated at a timing lagged behind that first reset pulse. The FM modulator further includes an adder (3) for adding the first reset pulse to the incoming video signal for lowering DC level at the leading edge portion of the horizontal synchronizing signal of the incoming video signal, and an oscillator (9, 9a, 9b, 10, 10a, 10b) whose oscillation frequency is changed dependent on the DC level of the output signal from the adder. An FM carrier FM modulated by video signal is output from the oscillator. The FM modulator further includes a circuit (9c, 10c) -43- responsive to the second reset pulse for resetting the oscillating circuit. FM carrier includes, in the horizontal synchronizing signal region, an oscillation stop region where the instantaneous frequency is approximately 0 and a reset region whose frequency and phase are corresponding to the second reset pulse. By using the reset region of the FM carrier as a reference signal for jitter detection during reproduction, a stable jitter detecting signal can be provided.
Iwamura Soichi
Nogami Hiroaki
G. Ronald Bell & Associates
Sharp Kabushiki Kaisha
LandOfFree
Carrier reset fm modulator and method of frequency... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Carrier reset fm modulator and method of frequency..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carrier reset fm modulator and method of frequency... will most certainly appreciate the feedback.
Profile ID: LFCA-PAI-O-1510507