Vertical focal plane shutter with constant curtain gap - set before actual release so that high speeds can be attained using constant driving force

摘要

A metal-bladed focal plane shutter keeps the slit width constant for a given exposure. The shutter has a mechanism for setting the closing blades behind the opening blades before they are released together. After exposure, the blades are returned to their cocked position across the film plane without exposing the film. The constant width feature permits high shutter speeds up to 1/2000 sec. Opening and closing blades are moved by hinged plates and coupled by tensioned actuating levers set in motion by the shutter release.