Color television camera with test image projector and precompensation means for correcting for imaging errors caused by oblique angles of incidence of test images on pickup elements

摘要

A color television camera has an optical color separation system provided in an optical path for scene light so as to produce pictures of different colors on pickup areas of pickup elements. The scene light extends along optical axes in the system which are central axes of the pickup areas. To synchronize picture signals so that picture coverage is optimized on the joint display thereof, the camera comprises a test image projector and an adjusting circuit. So as to obtain a compact optical system without using a movable reflecting surface for the test image, which surface would be moved in and out of the optical path, the light of the test image is projected at an oblique angle with respect to the optical axes into the color separation system and strikes the pickup areas at an oblique angle. Optical imaging errors produced thereby are precompensated. Optical precompensation means are provided in the form of an obliquely arranged test image slide and a cylindrical plano- convex correction lens. Electrical precompensation means include potentiometers or other adjustable memory circuits.