VEHICULAR HEADLAMP UNIT

• US 20090103323A1
• Filed: 10/09/2008
• Published: 04/23/2009
• Est. Priority Date: 10/17/2007
• Status: Active Grant

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Ishida, Hiroyuki
• Granted Patent: US 8,038,334 B2
• Time in Patent Office: Days
• US Class Current: 362/538
• CPC Class Codes: F21S 41/147 the main emission direction of the LED being angled to the optical axis of the illuminating device
• CPC Class Codes: F21S 41/148 the main emission direction of the LED being perpendicular to the optical axis
• CPC Class Codes: F21S 41/36 Combinations of two or more separate reflectors
• CPC Class Codes: F21S 41/365 successively reflecting the light
• CPC Class Codes: F21S 41/40 characterised by screens, non-reflecting members, light-shielding members or fixed shades
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A vehicular headlamp unit using a light-emitting element as a light source includes a projection lens arranged on an optical axis that extends in a vehicle longitudinal direction, and first and second light source units arranged rearward of the projection lens. The first light source unit includes a first light-emitting element arranged in a vicinity of the optical axis further rearward than a rear-side focal point of the projection lens, a first reflector arranged so as to cover the first light-emitting element from above and structured so as to reflect light from the first light-emitting element forward toward the optical axis, and a first mirror component having an upward-facing reflective surface that extends rearward generally along the optical axis from a vicinity of the rear-side focal point so as to reflect a portion of the reflected light from the first reflector upward. The second light source unit includes a second mirror component including a downward-facing reflective surface that extends diagonally downward toward a lamp rear side from a front end edge of the upward-facing reflective surface, a second light-emitting element arranged on the second mirror component facing forward and diagonally downward below the optical axis, a second reflector structured so as to reflect light from the second light-emitting element upward and generally converge such light at a region in a vicinity of the rear-side focal point on the downward-facing reflective surface, and a third reflector arranged downward of the second light-emitting element which reflects light from the second light-emitting element forward so that such light passes through a lower space of the projection lens.

Claims

1. A vehicular headlamp unit using a light-emitting element as a light source comprising:

a projection lens arranged on an optical axis that extends in a vehicle longitudinal direction, and first and second light source units arranged rearward of the projection lens,

wherein the first light source unit comprises;

a first light-emitting element arranged in a vicinity of the optical axis further rearward than a rear-side focal point of the projection lens,

a first reflector arranged so as to cover the first light-emitting element from above and structured so as to reflect light from the first light-emitting element forward toward the optical axis, and

a first mirror component having an upward-facing reflective surface that extends rearward generally along the optical axis from a vicinity of the rear-side focal point so as to reflect a portion of the reflected light from the first reflector upward, and

wherein the second light source unit comprises;

a second mirror component comprising a downward-facing reflective surface that extends diagonally downward toward a lamp rear side from a front end edge of the upward-facing reflective surface,

a second light-emitting element arranged on the second mirror component facing forward and diagonally downward below the optical axis,

a second reflector structured so as to reflect light from the second light-emitting element upward and generally converge such light at a region in a vicinity of the rear-side focal point on the downward-facing reflective surface, and

a third reflector arranged downward of the second light-emitting element which reflects light from the second light-emitting element forward so that such light passes through a lower space of the projection lens.

2. The vehicular headlamp unit according to claim 1, wherein the first mirror component and the second mirror component are integrally formed.

3. The vehicular headlamp unit according to claim 1, wherein a rear end portion of the second reflector is formed with a notched portion, and

the third reflector is arranged such that light from the second light-emitting element passing through the notched portion of the second reflector is incident to a reflective surface of the third reflector.

4. The vehicular headlamp unit according to claim 1, wherein the third reflector comprises:

a reflective surface having a focal point that is a point in a vicinity of the second light-emitting element, and a vertical cross-sectional shape formed by a parabola whose axis is an axis line that extends generally parallel to the optical axis.

5. The vehicular headlamp unit according to claim 1, wherein the third reflector includes a reflective surface having a vertical cross-sectional shape formed by an ellipse whose first focal point is a point in a vicinity of the second light-emitting element and whose second focal point is a predetermined point between the second light-emitting element and the projection lens, the vehicular headlamp unit further comprising:

an additional projection lens is arranged in a downward vicinity of the projection lens, the additional projection lens having an additional optical axis that extends generally parallel to the optical axis and also having a rear-side focal point that is a point in a vicinity of the second focal point.

6. The vehicular headlamp unit according to claim 2, wherein a rear end portion of the second reflector is formed with a notched portion, and

the third reflector is arranged such that light from the second light-emitting element passing through the notched portion of the second reflector is incident to a reflective surface of the third reflector.

7. The vehicular headlamp unit according to claim 2, wherein the third reflector includes a reflective surface having a focal point that is a point in a vicinity of the second light-emitting element, and a vertical cross-sectional shape formed by a parabola whose axis is an axis line that extends generally parallel to the optical axis.

8. The vehicular headlamp unit according to claim 3, wherein the third reflector includes a reflective surface having a focal point that is a point in a vicinity of the second light-emitting element and a vertical cross-sectional shape formed by a parabola whose axis is an axis line that extends generally parallel to the optical axis.

9. The vehicular headlamp unit according to claim 2, wherein the third reflector includes a reflective surface having a vertical cross-sectional shape formed by an ellipse whose first focal point is a point in a vicinity of the second light-emitting element and whose second focal point is a predetermined point between the second light-emitting element and the projection lens, the vehicular headlamp unit further comprising:

an additional projection lens is arranged in a downward vicinity of the projection lens, the additional projection lens having an additional optical axis that extends generally parallel to the optical axis and also having a rear-side focal point that is a point in a vicinity of the second focal point.

10. The vehicular headlamp unit according to claim 3, wherein the third reflector includes a reflective surface having a vertical cross-sectional shape formed by an ellipse whose first focal point is a point in a vicinity of the second light-emitting element and whose second focal point is a predetermined point between the second light-emitting element and the projection lens, the vehicular headlamp unit further comprising:

an additional projection lens is arranged in a downward vicinity of the projection lens, the additional projection lens having an additional optical axis that extends generally parallel to the optical axis and also having a rear-side focal point that is a point in a vicinity of the second focal point.