Light sensing film and light sensor circuit using the same

Abstract

A light sensing film including lamination of transparent/translucent material, an upper transparent electrode, a photosensitive dielectric layer including photosensitive dielectric material, a lower dielectric layer, and a lower electrode formed from conductive material such as carbon, a silver coating, a metallic plate, or a conductive coating, wherein: a capacitor is composed between the two electrodes; as the dielectric constant of the photosensitive dielectric layer between the two electrodes changes when light enters, capacitance of the capacitor changes; and accordingly light intensity can be detected. Zinc sulfide may be used as the photosensitive dielectric material, for sensitivity exclusively to ultraviolet rays. Titanium dioxide also may be used for longer life of the dielectric material. To regulate capacitance, an additional dielectric layer may be provided between the photosensitive dielectric layer and the lower electrode. The underside of the electrode may be laminated with protective material. A light sensing circuit wherein: said light sensing film is used as a capacitor for a CR or LC oscillator; change in capacitance C of the capacitor of the light sensing film is detected by counting oscillation frequency of said oscillator; and accordingly light intensity can be calculated.

Dependencies are inferred from the claim text.