Vehicle headlamp

1. A vehicle headlamp configured to form a light distribution pattern by light radiation from at least one lamp unit comprising:

at least one semiconductor light-emitting element as a light-source;

a projection lens disposed on an optical axis extending in a longitudinal direction of a vehicle; and

a first light-source unit and a second light-source unit each disposed rearward of the projection lens, wherein,

the first light-source unit comprises:

a first semiconductor light-emitting element facing substantially upward on a first reference axis extending substantially in the longitudinal direction;

a first reflector configured to reflect light from the first semiconductor light-emitting element forward and substantially near the first reference axis to substantially converge the reflected light substantially near a rear focal point of the projection lens; and

a forward travel blocking member extending rearward from substantially near the rear focal point to prevent the light reflected by the first reflector from traveling forward,

the second light-source unit comprises:

a second semiconductor light-emitting element facing substantially downward on a second reference axis extending substantially in the longitudinal directions; and

a second reflector configured to reflect light from the second semiconductor light-emitting element forward and substantially near the second reference axis to substantially converge the reflected light substantially near the rear focal point, and

when the first light-source unit is illuminated a low-beam light distribution pattern having cut-off lines at an upper end portion as reverse projection images of a front edge of the forward travel blocking member is formed, and a high-beam light distribution pattern spreading upward from the cut-off line is formed upon illumination of the second light-source unit.

2. The vehicle headlamp according to claim 1 , wherein a surface of the forward travel blocking member is a reflecting surface.

3. The vehicle headlamp according to claim 1 , wherein the second light-source unit comprises a reflecting member having a surface shape and extending rearward from the vicinity of the projection lens to reflect a part of light reflected from the second reflector.

4. The vehicle headlamp according to claim 3 , wherein the forward travel blocking member and the reflecting member are integral with respect to each other.

5. The vehicle headlamp according to claim 3 , wherein the second reflector and the reflecting member are a second translucent block.

6. The vehicle headlamp according to claim 1 , wherein the first reflector and the forward travel blocking member are a first translucent block.

7. The vehicle headlamp according to claim 1 , wherein the first semiconductor light-emitting element and the second semiconductor light-emitting element are deviated in a longitudinal direction.

8. The vehicle headlamp according to claim 1 , wherein the first semiconductor light-emitting element is arranged such that light emitted from the first semiconductor light-emitting element is not reflected by the second reflector.

9. The vehicle headlamp according to claim 1 , wherein the first reference axis and the second reference axis are not parallel to the optical axis.

10. A vehicle headlamp that forms a light distribution pattern by light radiation from at least one lamp unit that comprises:

at least one semiconductor light-emitting element as a light-source;

a projection lens disposed on an optical axis extending in a longitudinal direction of a vehicle;

a first light-source unit comprising:

a first semiconductor light-emitting element facing substantially upward on a first reference axis extending substantially in the longitudinal direction; and

a first reflector configured to reflect light from the first semiconductor light-emitting element forward and substantially near the first reference axis to substantially converge the reflected light substantially near a rear focal point of the projection lens;

a second light-source unit comprising:

a second semiconductor light-emitting element facing substantially downward on a second reference axis extending substantially in the longitudinal direction; and

a second reflector configured to reflect light from the second semiconductor light-emitting element forward and substantially near the second reference axis to substantially converge the reflected light substantially near the rear focal point; and

means for preventing light reflected by said first reflector from traveling forward;

wherein the first light-source unit and the second light-source unit are disposed rearward of the projection lens, and when the first light-source unit is illuminated a low-beam light distribution pattern having cut-off lines at an upper end portion as reverse projection images of a front edge of the means for preventing is formed, and a high-beam light distribution pattern spreading upward from the cut-off line is formed upon illumination of the second light-source unit.

11. The vehicle headlamp of claim 10 , wherein said means for preventing comprises one of a blocking member and a translucent block.

12. The vehicle headlamp according to claim 11 , wherein a surface of the blocking member is reflective.

13. The vehicle headlamp according to claim 10 , wherein the means for preventing and the reflecting member are integral with respect to each other.

14. The vehicle headlamp according to claim 10 , wherein the first reflector and the means for preventing are a first translucent block.

15. The vehicle headlamp according to claim 10 , wherein the second reflector and the reflecting member are a second translucent block.

16. The vehicle headlamp according to claim 10 , wherein the first semiconductor light-emitting element and the second semiconductor light-emitting element are deviated in a longitudinal direction.

17. A vehicle headlamp comprising:

a projection lens disposed on an optical axis extending in a longitudinal direction of a vehicle; and

a first light-source unit and a second light-source unit each disposed rearward of the projection lens;

wherein the first light-source unit comprises:

a first semiconductor light-emitting element facing substantially upward on a first reference axis extending substantially in the longitudinal direction;

a first reflector configured to reflect light from the first semiconductor light-emitting element forward and substantially near the first reference axis to substantially converge the reflected light substantially near a rear focal point of the projection lens; and

a forward travel blocking member to prevent the light reflected by the first reflector from traveling forward,

wherein the second light-source unit comprises:

a second semiconductor light-emitting element facing substantially downward on a second reference axis extending substantially in the longitudinal direction; and

a second reflector configured to reflect light from the second semiconductor light-emitting element forward and substantially near the second reference axis to substantially converge the reflected light substantially near the rear focal point;

wherein when the first light-source unit is illuminated a low-beam light distribution pattern having cut-off lines at an upper end portion as reverse projection images of a front edge of the forward travel blocking member is formed; and

wherein when the second light-source unit is illuminated a high-beam light distribution pattern spreading upward from the cut-off line is formed.