OPTICAL SCANNER, DISPLAY SYSTEM, MOBILE OBJECT, OPTICAL SCANNING CONTROL METHOD, AND RECORDING MEDIUM STORING PROGRAM CODE

An optical scanner and an optical scanning control method. The optical scanner includes a light source configured to emit light, a light deflector configured to deflect the light emitted from the light source to scan a scanning area two-dimensionally in a main scanning direction and a sub-scanning direction, and a photodetector configured to detect scanning light deflected by the light deflector to perform scanning on a detection field included in the scanning area. In the scanning area, a detection scanning area is formed by the scanning light so as to include an end of the detection field, and a size of the detection scanning area is changed. The optical scanning control method includes forming a detection scanning area by scanning light so as to include an end of a detection field included in a scanning area that is two-dimensionally scanned, and changing a size of the detection scanning area.