Lighting Unit for a Motor Vehicle Headlight for Generating a Light Distribution Having a Light-Dark Boundary

Patent metadata

Field	Value
Publication number	US-2022010938-A1
Application number	US-201917295506-A
Country	US
Kind code	A1
Filing date	Nov 21, 2019
Priority date	Nov 22, 2018
Publication date	Jan 13, 2022
Grant date	—

Abstract

The invention relates to a lighting unit for a motor vehicle headlight for generating a light distribution having a light-dark boundary, wherein the lighting unit ( 1 ) comprises a light source ( 2 ), a first reflector (R 1 ) having at least one focal point (F 1R1 ) in which the light source ( 2 ) is arranged, a second reflector (R 2 ) having at least one focal point (F 1R2 ), wherein the second reflector (R 2 ) is arranged downstream of the first reflector (R 1 ) in the beam path (S), and an aperture (B) arranged between the first reflector (R 1 ) and the second reflector (R 2 ). The first reflector (R 1 ) has a first reflector portion (R 11 ) and at least one second reflector portion (R 12 ), the aperture (B) being arranged in such a way that it is associated with the first reflector portion (R 11 ) of the first reflector (R 1 ) and is arranged at a small distance (D 1 ) near the beam (S 11 ) emitted from the first reflector portion (R 11 ), and clips the intermediate light image generated in the first reflector portion (R 11 ) to form a light-dark boundary, and the intermediate light image generated in the second reflector portion (R 12 ) is substantially free of influence of shadowing of the aperture arrangement.

First claim

1 . A lighting unit for a motor vehicle headlight for generating a light distribution with a light-dark boundary, the lighting unit ( 1 ) comprising:
at least one light source ( 2 ); at least one first reflector (R 1 ) having at least one focal point (F 1R1 ), wherein the at least one light source ( 2 ) is arranged in the at least one focal point (F 1R1 ); at least one second reflector (R 2 ) having at least one focal point (F 1R2 ), wherein the at least one first reflector (R 1 ) is configured to emit and forward light to the at least one second reflector (R 2 ) and wherein the at least one second reflector (R 2 ) is arranged downstream of the at least one first reflector (R 1 ) in a beam path (S) and is configured to display an intermediate light image generated by the first reflector (R 1 ); and at least one aperture (B) which is arranged in the beam path (S) between the at least one first reflector (R 1 ) and the at least second reflector (R 2 ), wherein: the first reflector (R 1 ) is constructed in at least two parts (R 11 , R 12 ) and has a first reflector portion (R 11 ) and at least one separate second reflector portion (R 12 ), each reflector portion (R 11 , R 12 ) having at least one focal point (F 1R11 , F 1R12 ) in each case, and at least one focal point (F 1R11 , F 1R12 ) of the first and the at least second reflector portion (R 11 , R 12 ) is arranged in each case congruently at the location of the at least one light source ( 2 ), the at least two part first reflector (R 11 , R 12 ) splitting is configured to split the beam (S 1 ) exiting from the at least one light source ( 2 ) into at least two separate beams (S 11 , S 12 ), the at least one aperture (B) is arranged in such a way that it is associated with the first reflector portion (R 11 ) of the first reflector (R 1 ) and is arranged at a small distance (D 1 ) near the beam (S 11 ) emitted from the first reflector portion (R 11 ), and clips the intermediate light image generated in the first reflector portion (R 11 ) to form a light-dark boundary, and the at least one aperture (B) is arranged at a greater distance (D 2 ) away from the beam (S 12 ) emitted from the at least second reflector portion (R 12 ) and the intermediate light image generated in the second reflector portion (R 12 ) is substantially free of influence of shadowing of the aperture arrangement.

2 . The lighting unit ( 1 ) according to claim 1 , wherein:
the first reflector (R 1 ) is constructed in a plurality of parts and has a plurality of reflector portions (R 11 , R 12 , R 1N ) having at least one focal point (F 1R11 , F 1R12 , F 1R1N ), the at least one light source ( 2 ) being arranged in each case in the at least one focal point (F 1R11 , F 1R12 , F 1R1N ), the at least one aperture (B) being arranged in such a way that it is exclusively associated with the first reflector portion (R 11 ) of the first reflector (R 1 ) and is arranged at a small distance (D 1 ) near the beam (S 11 ) emitted from the first reflector portion (R 11 ), and clips the intermediate light image generated in the first reflector portion (R 11 ) to form a light-dark boundary, and the at least one aperture (B) being arranged at a greater distance (D 2 , D N ) away from the beams (S 12 , S 1N ) emitted from the second (R 12 ) and optionally from the further reflector portions (R 1N ) of the first reflector (R 1 ) at a distance and the intermediate light images generated in the second and optionally the further reflector portions (R 12 , R 1N ) being substantially free of influence of shadowing of the aperture arrangement.

3 . The lighting unit ( 1 ) according to claim 1 , wherein the second reflector (R 2 ) is divided into two or more reflector segments (R 21 , R 22 , R 2N ) in a facet-like manner, a first reflector segment (R 21 ) of the second reflector (R 2 ) being associated with the intermediate light image generated in the first reflector portion (R 2 ) of the first reflector (R 1 ).

4 . The lighting unit ( 1 ) according to claim 1 , wherein the second reflector (R 2 ) is divided into two or more reflector segments (R 21 , R 22 , R 2N ) in a facet-like manner, precisely the first reflector segment (R 21 ) of the second reflector (R 2 ) being associated with the intermediate light image generated in the first reflector portion (R 11 ) of the first reflector (R 1 ).

5 . The lighting unit ( 1 ) according to claim 1 , wherein the at least one aperture (B) is attached directly to or at least near the first reflector portion (R 12 ) of the first reflector (R 1 ).

6 . The lighting unit ( 1 ) according to claim 1 , wherein the at least one aperture (B) is attached directly to or at least near the first reflector segment (R 21 ) of the second reflector (R 2 ).

7 . The lighting unit ( 1 ) according to claim 1 , wherein an aperture plane (BE) of the at least one aperture (B) corresponds to a focal plane (FE) of the at least one focal point (F 1R21 ) of the first reflector segment (R 21 ) of the second reflector (R 2 ).

8 . The lighting unit ( 1 ) according to claim 1 , wherein at least the first reflector portion (R 11 ) of the first reflector (R 1 ) is an ellipsoidal reflector which has a second focal point (F 2R11 ), the at least one aperture (B) being arranged so that it is spaced at a short distance (D 1 ) from the second focal point (F 2R11 ) of the first reflector portion (R 11 ).

9 . The lighting unit ( 1 ) according to claim 1 , wherein the two or more reflector portions (R 11 , R 12 , R 1N ) of the first reflector (R 1 ) are ellipsoidal reflectors in each case, each having a second focal point (F 2R11 , F 2R12 , F 2R1N ), the at least one aperture (B) being arranged such that it is arranged at a small distance (D 1 ) near the second focal point (F 2R11 ) of the first reflector portion (R 11 ) and the aperture (B) being arranged at a greater distance (D 2 , D N ) away from the second focal points (F 2R12 , F 2R1N ) of all further reflector portions (R 12 , R 1N ) of the first reflector (R 1 ).

10 . The lighting unit ( 1 ) according to claim 1 , wherein the small distance (D 1 ) from the beam (S 11 ) and/or from the second focal point (F 2R11 ) of the first reflector portion (R 11 ) of the first reflector (R 1 ) to an aperture edge (BK 1 ) of the aperture (B) is then defined as near the aperture (B) if the distance (D 1 ) is less than 1.7 times the value of a reference length (L), and the intermediate light image generated in the first reflector portion (R 11 ) is clipped to form a light-dark boundary, the reference length (L) being selected as the smallest distance from the distances of the maximum illuminance (E MAX ) of all reflector portions (R 11 , R 12 , R 1N ) of the first reflector (R 1 ) to the aperture edge (BK 1 ) of the aperture (B).

11 . The lighting unit ( 1 ) according to claim 1 , wherein the greater distance (D 2 , D N ) from the beam (S 12 , S 1N ) and/or from the second focal point (F 2R12 , F 2R1N ) of the second reflector portion (R 12 ) and possibly the further reflector portions (R 1N ) of the first reflector (R 1 ) to an aperture edge (BK 1 ) of the aperture (B) is then defined as away from the aperture (B), if by introducing the aperture (B) in the beam path (S) the luminous flux of the intermediate light image generated in the second and optionally the further reflector portions (R 12 , R 1N ) is reduced by at most 10%.

12 . The lighting unit ( 1 ) according to claim 1 , wherein the at least one aperture (B) has a first aperture edge (BK 1 ) for generating a first light-dark boundary and a second aperture edge (BK 2 ) for generating a second light-dark boundary and/or is adjustably arranged in the beam path (S) between the at least o

Assignees

• Zkw Group Gmbh
• Bayerische Motoren Werke Ag

Inventors

• Arlinghaus Stephan
• Erdl Helmut

Classifications

• F21W2102/165

  the borderlines between emitted regions and dark regions other than cut-off lines being variable · CPC title

• F21S41/336 Primary

  with discontinuity at the junction between adjacent areas · CPC title

• F21S41/147 Primary

  the main emission direction of the LED being angled to the optical axis of the illuminating device · CPC title

• F21S41/365

  successively reflecting the light · CPC title

• F21S41/43

  characterised by the shape thereof · CPC title