Headlight module and headlight device

A headlight module comprising:

• a light source to emit light;
• and
• a light guide projection optical element including
• an incidence surface to condense the light, thereby forming a first light,
• a first reflecting surface to reflect partial light as part of the first light, thereby forming light in a first light distribution pattern having a cutoff line from light other than the partial light, and
• a second reflecting surface inclined with respect to an optical axis of the light source so as to be farther from the optical axis as a distance from the light source along the optical axis increases,
• wherein the second reflecting surface forms light in a second light distribution pattern by reflecting second light formed of the partial light reflected by the first reflecting surface and adds the light in the second light distribution pattern to the light in the first light distribution pattern,
• the first reflecting surface includes a cutoff line formation part that forms the cutoff line by not reflecting the light other than the partial light, and
• the partial light is reflected at a position on the first reflecting surface different from the cutoff line formation part.