Image signal average picture level detecting apparatus.

摘要

The present invention relates to an image signal average picture level detecting apparatus for detecting the average picture level of the image brilliance signal, wherein the output of a first current mirroring circuit (6) used as the load of differential amplifying circuit (5), is fed into a smoothing circuit (8) by a second current mirroring circuit (7), so that the direct current voltage of the output and the detection voltage amplitude may be set optionally without causing the offset voltage of the output average picture level voltage with the current flowing through the second current mirroring circuit being made zero at the time of APL = 0%. <IMAGE>