Light projection method and light projection device

A light projection device, comprising:

• a light source;
• a diffractive optical element configured to modulate light emitted from the light source so as to project a pattern onto a target surface;
• an image acquisition unit configured to acquire the pattern;
• a processing unit coupled to the image acquisition unit and determining whether the pattern is normal, and if the pattern is normal, turning on the light source at a rated power level.

An electronic device, comprising:

• a body;
• and
• a light projection device;
• wherein the light projection device comprises:
• a light source;
• a diffractive optical element configured to modulate light emitted from the light source so as to project a pattern onto a target surface;
• an image acquisition unit configured to acquire the pattern;
• a processing unit coupled to the image acquisition unit and determining whether the pattern is normal, and if the pattern is normal, turning on the light source at a rated power level.