Dot matrix projector, facial recognition module, and electronic device

A facial recognition module comprising:

• a dot matrix projector used to emit infrared light, the dot matrix projector comprising:
• an infrared light source used to emit infrared light;
• a collimating lens, the collimating lens used to receive the infrared light from the infrared light source and collimate the infrared light to be parallel infrared light;
• a semi-transparent and semi-reflective plate on an output side of the collimating lens, the semi-transparent and semi-reflective plate used to divide the parallel infrared light into a first part directly transmitting the semi-transparent and a second part being reflected by the semi-transparent and semi-reflective plate;
• a diffractive optical element on an output path of the semi-transparent and semi-reflective plate and configured to convert infrared light into infrared spots;
• and
• an infrared light conversion film on another output path of the semi-transparent and semi-reflective plate and configured to convert infrared light into visible light;
• and
• an infrared camera used to receive reflected infrared light.