Semi-transparent semi-retroreflective film and air display device

An air display device, comprising:

• a light source;
• a first polarizer, disposed adjacent to the light source and located in a light-emitting direction of the light source;
• a semi-transparent semi-retroreflective film and a reflective polarizer, sequentially disposed at a side of the first polarizer away from the light source;
• a first ¼ wave plate disposed at a side of the air display device adjacent to the first polarizer;
• and
• a second ¼ wave plate disposed between the reflective polarizer and the semi-transparent semi-retroreflective film, wherein
• the air display device is configured such that polarized light emitted from the light source and incident from the first polarizer, upon being processed by an internal optical path of the air display device, exits from the reflective polarizer to form an air image at a side of the air display device away from the first polarizer, and wherein
• the semi-transparent semi-retroreflective film comprises:
• a retroreflective layer having a microstructure;
• and
• a semi-transparent semi-reflective layer and a planarization layer sequentially disposed at a light exiting side of the retroreflective layer, wherein
• the semi-transparent semi-retroreflective film is configured such that a part of incident light reaching a light incident side of the retroreflective layer is retroreflected in an incident direction, and another part of the incident light passing through the retroreflective layer, the semi-transparent semi-reflective layer and the planarization layer exits in the incident direction.