Detective Comics
Detective Comics is an American comic book series published by DC Comics. The first volume, published from 1937 to 2011 (and later continued in 2016), is best known for introducing the superhero Batman in "Detective Comics" #27 (cover dated May 1939).
Bat-Signal
The Bat-Signal first appeared in "Detective Comics" #60 (February 1942). The signal has several different origins in comics featuring post-Crisis continuity. It is introduced as a new tool after the Batman's first encounter with the Joker in the 2005 series "", and also during the 1990 "" storyline in "Legends of the Dark Knight".