DIGITAL CONVERSION SYSTEM FOR A COLOR VIDEO SIGNAL THAT IS CAPABLE OF CONVERTING AN ANALOG COMPOSITE AND AN ANALOG COMPONENT VIDEO SIGNAL INTO DIGITAL COMPOSITE SIGNAL AND A DIGITAL COMPONENT COLOR SIGNAL

摘要

ABSTRACT OF THE DISCLOSUREA digital conversion system for a color videosignal comprising a system which selectively converts ananalog composite color video signal and analog primary colorvideo signals to digital signals includes: a matrixcircuit (17) which forms a luminance signal and first andsecond color difference signals from the input analog primarycolor video signals, and a switching circuit (18) whichconverts the first and second color difference signals to asequential color difference signal. A switch (28) selectsthe luminance signal from the matrix circuit (17) or theinput NTSC analog composite color video signal. A firstanalog to digital converter (411 receives an output from theswitch (28); and a second analog to digital converter (42)receives the sequential color difference signal. A digitalcomposite color video signal or a digital luminance signalis obtained from the first analog to digital converter (41),and a digital line sequential color difference signal isobtained from the second analog to digital converter (42).The line sequential chrominance signal can be digitized by asingle inexpensive A/D converter which has a slow processingspeed, so as to produce an inexpensive digital conversionsystem which is small.