Photoelectric measuring device

摘要

A transparent photocell formed of two thin film layers of a semi-conductor material and an intervening thin film layer of a photoconductor material, a constant voltage being applied across the semi-conductor layers and the current through the cell being detected as a measure of the intensity of light incident on the cell. The thin film nature of the cell enables it to be combined with a lens of an optical system as a plurality of laminae coated onto a surface of said lens.