Light exposure apparatus

Claim 1

A COMPACT SOURCE OF UNIFORM INTENSE WIDE-AREA ILLUMINATION ADAPTED FOR EXPOSURE OF LIGHT-SENSITIVE SHEET MATERIAL IN CONTACT WITH A GRAPHIC ORIGINAL AT AN EXPOSURE AREA COMPRISING: A LINE SOURCE OF HIGH INTENSITY LIGHT EXTENDING BETWEEN TWO OPPOSED REFLECTORS ADJACENT THE ENDS OF SAID EXPOSURE AREA, SAID LINE SOURCE BEING CENTRALLY DISPOSED BENEATH THE EXPOSURE AREA AT A SHORT DISTANCE SUCH THAT THE ANGLE OF DIRECT ILLUMINATION IS NOT GREATER THAN ABOUT 140 DEGREES; AN AT LEAST PARTIALLY LIGHT-TRANSMISSIVE SHIELD CLOSELY OVERLYING SAID LINE SOURCE AND SPACED THEREFROM TO PROVIDE A NARROW SPACE AROUND SAID LAMP FOR CONTROLLED PASSAGE OF AIR; AND A PAIR OF GENERALLY ARCUATE REFLECTORS EACH EXTENDING FROM JUST BENEATH SAID LINE SOURCE TO THE CORRESPONDING SIDE EDGE OF SAID EXPOSURE AREA AND EACH BEING GENERALLY CENTERED ON A POINT LYING ON THE PERPENDICULAR BISECTOR OF A LINE CONNECTING SAID LINE SOURCE AND SAID SIDE EDGE; THE SAID EXPOSURE SOURCE BEING FURTHER CHARACTERIZED AS SUBSTANTIALLY FULFILLING THE REQUIREMENT INDICATED BY THE EQUATION ED+EI=K, WHERE ED AND EI REPRESENT INTENSITY OF ILLUMINATION BY DIRECT RAYS AND INDIRECT OR REFLECTED RAYS RESPECTIVELY, AND K IS A CONSTANT.