Solid state color imaging apparatus

Claim 1

In a solid state color imaging apparatus comprising: a plurality of photo sensitive elements arranged horizontally and vertically in an array; a signal read-out circuit scanning the plurality of photo sensitive elements of said array with parallel scanning of the photo sensitive elements arranged in sets of two horizontal lines and delivering photo signals from the photo sensitive elements to first and second output circuits associated with the two horizontal lines of the respective sets; a mosaic color filter having luminance filtering counterparts which alternate horizontally and vertically one after the other with one of first and second filtering counterparts which are arranged at the remaining positions of the mosaic on alternate horizontal lines, each of the filtering counterparts being in register with each of the photo sensitive elements; and a signal processing circuit for converting the signals developed by the first and second output circuits into a composite color signal combined with a chrominance subcarrier; the improvement wherein said signal read-out circuit includes means for scanning the plurality of photo sensitive elements of said array at a horizontal clock frequency which is twice the chrominance subcarrier frequency, whereby a first color difference signal between a first chrominance signal corresponding to the first filtering counterpart and a luminance signal is delivered to the first output circuit whereas a second color difference signal between a second chrominance signal corresponding to the second filtering counterpart and the luminance signal is delivered to the second output circuit, said first and second color difference signals varying at the same frequency as the chrominance subcarrier frequency; and wherein said signal processing circuit includes bandpass filters respectively connected to the first and second output circuits, first means for shifting by π/2 the phase of the output signal from one of the bandpass filters and for adding the phase-shifted signal to the output signal from the other bandpass filter, second means for obtaining a luminance signal component from the first and second output circuits, and third means for forming a composite color signal from the outputs of the first and second means and a synchronizing signal.