A optical projector device less vulnerable to deformation of projected light by generated heat includes a printed circuit board, a light source, and an optical module. The heat-generating light source emits a laser beam, the optical module being mounted on the printed circuit board and surrounding the light source. The optical module comprises a lens holder, a collimating optical element received in the lens holder, and a diffractive optical element away from the light source. The lens holder comprises an outer lens holder and an inner lens holder fixed in the outer lens holder, and the diffractive optical element is received in the inner lens holder, this arrangement enables the dissipation of any heat-expansion force away from these elements.