Building materials such as glass will block the ultraviolet light of the sunlight when the user moves from the outdoor environment into the indoor environment, so the amount of the ultraviolet light in the room is very low, which is not enough to excite the organic photochromic material. In this case, the color shifting layer 350 is in an unexcited state. In this state, the color shifting layer 350 is transparent and colorless, has good light transmittance, and hardly reflects the light incident on it. Moreover, the color shifting layer also will not block the light emitted by the optical sensor used as the fingerprint collection component 370, such that the light emitted by the optical sensor can act on the fingerprint of the user without being blocked when fingerprint information needs to be collected, thus improving the accuracy and efficiency of fingerprint collection.

Certainly, it is understandable that the color shifting layer 280 of this embodiment may also be made of a photochromic material excited by an infrared light, rather than the photochromic material excited by the ultraviolet light, that is, an infrared photosensitive material in the photochromic materials, such as diarylethene photochromic compounds.