Light transmission control apparatus

摘要

An apparatus for controlling the amount of converged light having a high energy density which is transmitted through a predetermined optical path. The apparatus or light switch is disposed in the vicinity of the optical path and operable either in a stepwise manner or in a stepless manner as desired. A flat plate made of isotropic graphite serves as a light interceptor and is driven by an operation member into and out of the optical path within a plane which is perpendicular to the optical path. The plate does not reflect the light or become heated by the light due to provision of heat radiator means.