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EP-4735793-A1 - LIGHT MODULE AND LIGHTING DEVICE FOR A MOTOR VEHICLE

EP4735793A1EP 4735793 A1EP4735793 A1EP 4735793A1EP-4735793-A1

Abstract

The invention relates to a light module (100), in particular for a motor vehicle head-light, comprising: - a light source (1) capable of emitting light rays (10) around a main emission direction (X), said main emission direction (X) being oriented substantially horizontally in a mounting position of the light module (100), - a reflector (2) with a concave reflective surface configured to collect and reflect the light rays (10) emitted by the light source (1) into a light beam along an optical axis (OA) of the light module (100), said optical axis (OA) being oriented substantially horizontally in a mounting position of the light module (100), wherein the reflector (2) features: • a front edge (21) running for the most part in a plane substantially perpendicular to the optical axis (OA), • a lateral edge (22) running for the most part in a plane substantially perpendicular to the main emission direction (X), and • a horizontal edge (23a, 23b, 23c) featuring two horizontal segments (23a, 23b) running for the most part in distant planes substantially parallel to both the main emission direction (X) and the optical axis (OA), said horizontal segments (23a, 23b) being connected by a kink segment (23c), and - an optical system (3) configured to project the light beam and to form an image of the reflective surface of the reflector (2), wherein said front edge (21) delimits a lower portion of the light image formed and said horizontal edge (23a, 23b, 23c) delimits an upper portion of the light image forming a kinked horizontal cut-off line.

Inventors

  • JEZERSEK, Nejc

Assignees

  • HELLA Saturnus Slovenija d.o.o.

Dates

Publication Date
20260506
Application Date
20230629

Claims (10)

  1. 1 . Light module (100), in particular for a motor vehicle headlight, comprising: - a light source (1 ) capable of emitting light rays (10) around a main emission direction (X), said main emission direction (X) being oriented substantially horizontally in a mounting position of the light module (100), - a reflector (2) with a concave reflective surface configured to collect and reflect the light rays (10) emitted by the light source (1 ) into a light beam along an optical axis (OA) of the light module (100), said optical axis (OA) being oriented substantially horizontally in a mounting position of the light module (100), wherein the reflector (2) features: • a front edge (21 ) running for the most part in a plane substantially perpendicular to the optical axis (OA), • a lateral edge (22) running for the most part in a plane substantially perpendicular to the main emission direction (X), and • a horizontal edge (23a, 23b, 23c) featuring two horizontal segments (23a, 23b) running for the most part in distant planes substantially parallel to both the main emission direction (X) and the optical axis (OA), said horizontal segments (23a, 23b) being connected by a kink segment (23c), and - an optical system (3) configured to project the light beam and to form an image of the reflective surface of the reflector (2), wherein said front edge (21 ) delimits a lower portion of the light image formed and said horizontal edge (23a, 23b, 23c) delimits an upper portion of the light image forming a kinked horizontal cut-off line.
  2. 2. Light module (100) according to claim 1 , characterised in that the main emission direction (X) forms an angle with the optical axis (OA) in the range of 45° to 135°, preferably 80° to 110°.
  3. 3. Light module (100) according to claim 1 or 2, characterised in that the front edge (21 ) of the reflector (2) sweeps an angular range about an axis parallel to the optical axis (OA) through a focal point (F1 , F2) of the reflector (2) of 70° to 110°, preferably 80° to 100°.
  4. 4. Light module (100) according to one of the previous claims, characterised in that the reflective surface of the reflector (2) represents a segment of a paraboloid or a segment of an ellipsoid or a free-form shape, wherein the light source (1 ) is positioned in or close to the focal point (F1 ) of said paraboloid, ellipsoid or free-form.
  5. 5. Light module (100) according to one of the previous claims, characterised in that the reflector (2) is configured and positioned relative to the light source (1 ) so that the light rays (10) reflected from the reflective surface are parallel to the optical axis (OA) or have an angle of inclination (a) with respect to the optical axis (OA) smaller than or equal to 25°, preferably smaller than or equal to 10°.
  6. 6. Light module (100) according to one of the previous claims, characterised in that the kink segment (23c) of the reflector (2) is positioned in the focal plane (F) of the optical system (3).
  7. 7. Light module (100) according to one of the previous claims, characterised in that the distance along the optical axis (OA) between the front edge (21 ) of the reflector (2) and the optical system (3) is in the range of 5 mm to 200 mm, preferably 30 mm to 50 mm.
  8. 8. Light module (100) according to one of the previous claims, characterised in that the optical system (3) features a projection lens, especially a thin lens.
  9. 9. Lighting device for a motor vehicle, in particular a headlight, comprising at least one light module (100) according to one of the previous claims, wherein in a mounting position of the lighting device the main emission direction (X) of the light source (1 ) and the optical axis (OA) are oriented substantially horizontally.
  10. 10. Headlight according to claim 9, characterised in that the light module (100) is configured to generate a low beam function.

Description

Light module and lighting device for a motor vehicle Description The present invention relates to a light module and a related lighting device for a motor vehicle, especially a headlight. PRIOR ART The document US 11 ,280,464 B2 discloses a concept for a light module based on a reflector forming a light beam by collecting and reflecting the light emitted from a light source positioned in a focal point of the reflector and a subsequent optical projection system configured to project said light beam, i.e., to project an image of the reflective surface of the reflector. The reflector features the form of a circular or elliptical half-paraboloid covering the upper half space above the light source in the mounting position of the light module. The front edge of the reflector with respect to the general direction of propagation of the light beam delimits the lower portion of the projected image, and the rear edge of the reflector being the edge closest to the light source delimits the upper portion of the projected image. When the light module is used to form the low beam function of a motor vehicle headlight, the rear edge of the reflector thus essentially determines the detailed course of the cut-off line of the light distribution projected onto the street in front of the motor vehicle. A disadvantage of this concept is the very short distance between the light source and the rear edge of the reflector shaping the cut-off line, since even slight deviations of the position of the light source from a nominal position lead to strong changes in the light intensity distribution around the cut-off line. Furthermore, the spatial arrangement of the light source below the reflector in the mounting position of the light module requires the printed-circuit board (PCB) supplying the light source to be positioned horizontally below the light source. Such positioning leads to difficult thermal management of the light module, as the air heated by the operation of the light source accumulates in the space enclosed between the PCB and the concave reflector and cannot be effectively dissipated. DISCLOSURE OF THE INVENTION It is an object of the present invention to propose a light module based on the above concept, that avoids the aforementioned disadvantages of the prior art. This object is achieved by a light module and a related lighting device as taught by claims 1 and 8 of the present invention. Advantageous embodiments are defined in the subclaims. The invention discloses a light module, in particular for a motor vehicle headlight, comprising: - a light source capable of emitting light rays around a main emission direction, said main emission direction being oriented substantially horizontally in a mounting position of the light module, - a reflector with a concave reflective surface configured to collect and reflect the light rays emitted by the light source into a light beam along an optical axis of the light module, said optical axis being oriented substantially horizontally in a mounting position of the light module, wherein the reflector features: • a front edge running for the most part in a plane substantially perpendicular to the optical axis, • a lateral edge running for the most part in a plane substantially perpendicular to the main emission direction, and • a horizontal edge featuring two segments running for the most part in distant planes substantially parallel to both the main emission direction and the optical axis, said segments being connected by a kink segment, and - an optical system configured to project the light beam and to form an image of the reflective surface of the reflector, wherein said front edge delimits a lower portion of the light image formed and said horizontal edge delimits an upper portion of the light image forming a kinked horizontal cut-off line. The basic idea of the invention is to reduce the solid angle covered by the reflector, which allows greater freedom in positioning the light source and the supplying PCB relative to the reflector. The horizontal edge of the reflector, which determines the cutoff line of the light image projected by the optical system, is adapted accordingly and features a kinked course extending from the rearmost section of the reflector to the front edge. The light source is oriented to emit light rays around a main emission direction that is substantially horizontal in the mounting position of the light module, i.e., in the position and orientation which the light module occupies in intended use, in particular when used in a lighting device of a motor vehicle. Accordingly, the PCB that is positioned on the backside of the light source takes up an upright position, which is more convenient and more efficient for the dissipation of operational heat from the light source compared to the case of a horizontal PCB orientation. Such a positioning of the light source relative to the horizontal edge of the reflector allows a larger distance between the light