The average picture level (APL) of a video luminance signal is detected, wherein the output of a first current mirror circuit used as the load of a differential amplifying circuit is fed into a smoothing circuit via a second current mirror circuit. The direct current voltage of the output and the detection...http://www.google.fr/patents/US5223927?utm_source=gb-gplus-shareBrevet US5223927 - Image signal average picture level detecting apparatus
Image signal average picture level detecting apparatus
