Television – Image signal processing circuitry specific to television – Color encoder or chrominance signal modulator
Patent
1996-04-04
1997-06-10
Hsia, Sherrie
Television
Image signal processing circuitry specific to television
Color encoder or chrominance signal modulator
348660, 348724, H04N 965
Patent
active
056381352
ABSTRACT:
A digital encoder includes a matrix circuit for synthesizing chrominance signals R-Y and B-Y based on RGB signals sampled at a predetermined sampling frequency which is an integral multiple of a chrominance subcarrier; low-pass filters; a delay circuit; a switch circuit for reducing a frequency of an output from the low-pass filters; a digital modulator for subjecting a chrominance subcarrier to quadrature two-phase balanced modulation using an output signal from the switch circuit so as to output a chrominance signal having a sampling frequency 1/m that of the predetermined sampling frequency; a sampling frequency conversion circuit for multiplying the sampling frequency of the chrominance signal by a factor of m so as to output a chrominance signal having the predetermined sampling frequency; and an adder for computing a sum of the luminance signal delayed by the delay circuit, the chrominance signals output by the sampling frequency conversion circuit and a composite synchronizing signal so as to synthesize a composite video signal. In another construction, a digital color encoder of the present invention includes a matrix circuit for producing a luminance signal and chrominance signals by blending RGB signals using a predetermined ratio assigned to each color component; a trap filter for rejecting transmission of luminance signal components that correspond to a chrominance subcarrier frequency; a modulator for producing a chrominance signal having an arbitrary phase, based on the chrominance signals; an adder for producing a composite color signal by computing a sum of the luminance signal processed by the trap filter and the chrominance signal produced by the modulator.
REFERENCES:
patent: 4982179 (1991-01-01), Ogawa
Hsia Sherrie
Ricoh & Company, Ltd.
LandOfFree
Digital color encoder with improved circuitry does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Digital color encoder with improved circuitry, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Digital color encoder with improved circuitry will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-768811