Optical system for camera tube

摘要: A spatial frequency filter apparatus for suppressing spurious signals generated in an optical system a television camera incorporating color encoding includes two elements (1 and 2) filtering natural light introduced through lens (11) both horizontal vertical directions plate such as quarter wavelength (3) or rotatory polarization (13) interposed between the 2). By causing to transmit (3 13) before being (12), are suppressed, whereby false which may otherwise make appearance at contours of image picked up by tube can be significantly reduced.