Vehicular headlamp having improved low-beam illumination

• US 6,402,355 B1
• Filed: 08/08/2000
• Issued: 06/11/2002
• Est. Priority Date: 08/19/1999
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Kinouchi, Toshiyuki
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Ton, Anabel
• Application Number:
  US09/635,474
• Time in Patent Office: 672 Days
• Field of Search: 362/538, 362/539, 362/305, 362/516-518, 362/303, 362/512, 362/513
• US Class Current: 362/514
• CPC Class Codes: F21S 41/336 with discontinuity at the junction between adjacent areas
• CPC Class Codes: F21S 41/435 Hoods or cap-shaped

Abstract

A vehicular headlamp for low-beam illumination with a light distribution pattern having a horizontal cutoff line and a diagonal cutoff line so as to improve long distance visibility on the road on which the vehicle is traveling. An upward deflecting reflecting element for irradiating a beam onto a space in an area above a diagonal cutoff line is formed at the outer peripheral edge of the diagonal cutoff line forming area on a reflecting surface of a reflector. As a result, a small light distribution pattern P1 exhibiting high luminous intensity is formed in a space in the area above the diagonal cutoff line.

Claims

1. A vehicular headlamp having a reference axis extending in a longitudinal direction of a vehicle on which said headlamp is mounted, comprising:

a light source;

a reflector for reflecting light from said light source forward and providing low-beam illumination in a light distribution pattern having a horizontal cutoff line and a diagonal cutoff line that slopes upwards at an angle of about 15°

from said horizontal cutoff line; and

an upward deflecting reflecting element for irradiating a beam towards a space in an area adjacent to said reference axis and above said diagonal cutoff line, said upward deflecting element being disposed on an outer peripheral edge of a reflecting surface of said reflector.

2. The vehicular headlamp according to claim 1, wherein the beam irradiation towards said space in said area above said diagonal line provides a luminance of at least 0.8 lux at a distance 25 meters to the front of said headlamp at 0.5°

above said reference axis of said headlamp and 1°

towards the road on which the vehicle is traveling.

3. The vehicular headlamp according to claim 1, wherein said upward deflecting reflecting element is disposed within an angular range of not more than 30°

around said reference axis of said headlamp.

4. The vehicular headlamp according to claim 2, wherein said upward deflecting reflecting element is disposed within an angular range of not more than 30°

around said reference axis of said headlamp.

5. The vehicular headlamp according to claim 1, further comprising a shade for shading incident light from said light source onto said upward deflecting reflecting element.

6. The vehicular headlamp according to claim 1, further comprising a shade, said shade comprising a cap-shaped portion surrounding a front end portion of said light source and shading direct light to the front of said headlamp from said light source, a support portion for supporting said cap portion, a rear end portion of said support portion being fixed to said reflector, and a protruding portion disposed at a position on a side of a rear edge of said cap portion slightly above an optical axis of said reflector for shielding direct light from said light source onto said upward deflecting element.

7. The vehicular headlamp according to claim 6, wherein the beam irradiation towards said space in said area above said diagonal line provides a luminance of at least 0.8 lux at a distance 25 meters to the front of said headlamp at 0.5°

above said reference axis of said headlamp and 1°

towards the road on which the vehicle is traveling.

8. The vehicular headlamp according to claim 6, wherein said upward deflecting reflecting element is disposed within an angular range of not more than 30°

around said reference axis of said headlamp.

9. The vehicular headlamp according to claim 5, wherein said upward deflecting reflecting element is disposed within an angular range of not more than 30°

around said reference axis of said headlamp.

10. The vehicular headlamp according to claim 5, wherein said shade surrounds said light source at an angle of 165°

around an optical axis of said reflector.

11. The vehicular headlamp according to claim 1, wherein said light source is disposed substantially coaxial with an optical axis of said reflector.

12. A vehicular headlamp comprising:

a light source;

a reflector for reflecting light from said light source forward and providing low-beam illumination in a light distribution pattern having a horizontal cutoff line and a diagonal cutoff line that slopes upwards at an angle of about 15°

from said horizontal cutoff line;

an upward deflecting reflecting element for irradiating a beam towards a space in an area above said diagonal cutoff line, said upward deflecting element being disposed on an outer peripheral edge of a reflecting surface of said reflector; and

a shade for shading incident light from said light source onto said upward deflecting reflecting element,

wherein said upward deflecting reflecting element is disposed within an angular range of not more than 30°

around a reference axis of said headlamp.

13. The vehicular headlamp according to claim 12, said shade comprising a cap-shaped portion surrounding a front end portion of said light source and shading direct light to the front of said headlamp from said light source, a support portion for supporting said cap portion, a rear end portion of said support portion being fixed to said reflector, and a protruding portion disposed at a position on a side of a rear edge of said cap portion slightly above an optical axis of said reflector for shielding direct light from said light source onto said upward deflecting element.

14. The vehicular headlamp according to claim 12, wherein said shade surrounds said light source at an angle of 165°

around an optical axis of said reflector.

15. The vehicular headlamp according to claim 12, wherein said light source is disposed substantially coaxial with an optical axis of said reflector.

16. A vehicular headlamp comprising:

a light source;

a reflector for reflecting light from said light source forward and providing low-beam illumination in a light distribution pattern having a horizontal cutoff line and a diagonal cutoff line that slopes upwards at an angle of about 15°

from said horizontal cutoff line;

an upward deflecting reflecting element for irradiating a beam towards a space in an area above said diagonal cutoff line, said upward deflecting element being disposed on an outer peripheral edge of a reflecting surface of said reflector; and

a shade for shading incident light from said light source onto said upward deflecting reflecting element,

wherein the beam irradiation towards said space in said area above said diagonal line provides a luminance of at least 0.8 lux at a distance 25 meters to the front of said headlamp at 0.5°

above said reference axis of said headlamp and 1°

towards the road on which the vehicle is traveling.

17. The vehicular headlamp according to claim 16, said shade comprising a cap-shaped portion surrounding a front end portion of said light source and shading direct light to the front of said headlamp from said light source, a support portion for supporting said cap portion, a rear end portion of said support portion being fixed to said reflector, and a protruding portion provided at a position on a side of a rear edge of said cap portion slightly above an optical axis of said reflector for shielding direct light from said light source onto said upward deflecting element.

18. The vehicular headlamp according to claim 16, wherein said shade surrounds said light source at an angle of 165°

around an optical axis of said reflector.

19. The vehicular headlamp according to claim 16, wherein said light source is disposed substantially coaxial with an optical axis of said reflector.