Method of adjusting the current intensity of an electron beam in a pick-up tube and television camera system suitable therefor.

摘要

In a television camera comprising at least one pick-up tube (PT) it is desirable to generate an electron beam (ER) with a current intensity which is greater than strictly necessary for obtaining a picture signal (PS) with a nominal amplitude between a black level and a white value. This prevents comet tails from being produced on display behind brighter, moving scene portions, caused by an insufficient stabilization of a potential image scanned by the beam (ER). Instead of acting in the optical path, electronic action is taken on the beam current setting. To that end the electron beam is blanked periodically during a beam current setting period before each field period in which a field scan is effected, during at least one preceding field period and within said field period(s) during at least a line period portion of at least one plurality of consecutive line periods. Setting is effected to a maximum picture signal amplitude to be reached at a substantially minimum beam current intensity.