Electronic apparatus

An electronic apparatus, comprising:

• a housing having a light transmission portion;
• and
• a covering structure comprising at least three coating layers sequentially stacked above the light transmission portion, the coating layers respectively having reflected lights, different thicknesses, different refractive indices, different reflectivities, and different transmissivities, wherein the thickness of each of the coating layers is uniform;
• wherein the covering structure is configured to transmit most of light in a wavelength range of infrared spectrum and to reflect most of light in a wavelength length range of visible spectrum;
• wherein at least a pair of the reflected lights have a same phase so that said at least a pair of the reflected lights constructively interfere, and at least another pair of the reflected lights have a different phase so that said another pair of the reflected lights destructively interfere, such that interference fringes are formed to present a virtual image with a pattern;
• and
• wherein:
• the three coating layers comprise a first coating layer, a second coating layer, and a third coating layer;
• the reflected lights comprise a first reflected light reflected from the first coating layer and having a first phase, a second reflected light reflected from the second coating layer and having a second phase, and a third reflective light reflected from the third coating layer and having a third phase;
• the first phase is the same as the second phase, such that the first and second reflected lights constructively interfere;
• and
• the second phase is different from the third phase, such that the second and third reflected lights destructively interfere.