Patent ID: 8071933
Filing Date: 2011-12-06
Classification: A47K,G01F

Abstract:
1. A removable and replaceable keying component which is required for operation of a mechanism, the keying component including an electromagnetic radiation waveguide, the waveguide having an inlet for electromagnetic radiation and an outlet electromagnetic radiation, the waveguide providing a path for transmission of electromagnetic radiation from the inlet to the outlet, the waveguide includes a photochromic portion which contains a photochromic dye which has an inherent unactivated state and an activated state, on radiating with a dose of activation electromagnetic radiation in a range of activation wavelengths the photochromic dye changing from the unactivated to the activated state, with the photochromic dye in the unactivated state the photochromic portion having an inherent first transmission characteristic of electromagnetic radiation in a range of test wavelengths, and with the photochromic dye in the activated state the photochromic portion having a second transmission characteristic of electromagnetic radiation in the range of test wavelengths different than the first transmission characteristic, the keying component serving a function in the operation of the mechanism in addition to the function of providing the waveguide.