US Patent 11035813 Detection device and identification system

A detection device includes a light refraction structure and a resistance detection circuit. The light refraction structure includes a substrate, a conductive layer, and a refraction layer. The conductive layer and the refraction layer are formed on the substrate. The conductive layer includes a resistance. The resistance detection circuit is electrically coupled to the conductive layer and is adapted to detect the resistance of the conductive layer. The resistance detection circuit generates a detection signal according to a change in the resistance, and the detection signal represents a state of the refraction layer.