Color imaging apparatus with lost carrier compensation.

摘要

In a color imaging apparatus, an optical image is focused on a photoelectrical conversion target (6) of a color image pickup tube (1) through a color stripe filter having a plurality of successively arranged recurrent groups of different color stripes and converted to an electrostatic image which is scanned in rectangular raster form by an electron beam to generate a color-multiplexed video signal. First and second index stripe bands (41, 40, 48) are located adjacent to edges of the rectangular raster scan area to generate first and second index signals. Prior to normal imaging, the target is illuminated uniformly with light of a predetermined color to generate a reference "carrier" which is stored in a field memory (22; 91; 126) together with the index signals. During read mode, a carrier is generated having a component modulated in phase with the stripes of each recurrent group and a component modulated in amplitude with the intensity of the picture elements of the image. The memory is read to generate a reference carrier and first and second reference index signals. These index signals are compared by comparators (23, 24; 80; 110, 111) in frequency and phase with the corresponding index signals from the target and stored in sample-and-hold circuits (25, 26; 81, 82; 112, 113) to control the frequency and phase relationships between the modulated and reference carriers.