Lighting unit for a motor vehicle

Abstract

A lighting unit for a motor vehicle having at least one light guide and at least one circuit board having at least one light-emitting diode. The circuit board and the light guide are attached to one another. The lighting unit is elongate and curved in the manner of a crescent with a light guide extending over the length of the lighting unit and with multiple elongated, rigid circuit boards that are each equipped with multiple light-emitting diodes, wherein the circuit boards are identically constructed and lined up in their longitudinal direction along the light guide in such a manner that the light of the light-emitting diodes can be coupled into the light guide perpendicularly to the longitudinal extent thereof, and wherein the circuit boards are connected to one another electrically and in terms of signaling by cables.

Claims

1. A lighting unit for a motor vehicle, the lighting unit comprising: at least one light guide; and circuit boards each having light-emitting diodes, wherein the circuit boards and the at least one light guide are attached to one another, wherein the lighting unit is designed to be elongate and curved in a manner of a crescent with the at least one light guide extending over a length of the lighting unit and with the circuit boards that are each rigid and elongated, wherein the circuit boards are each substantially identically constructed and are lined up in their longitudinal direction along the at least one light guide such that light of the light-emitting diodes is adapted to be coupled into the at least one light guide substantially perpendicularly to the longitudinal extent thereof, wherein the circuit boards are connected to one another electrically and in terms of signaling by cables, and wherein each of the circuit boards have a curved shape in outline with a radius of curvature.

2. The lighting unit according to claim 1, wherein the circuit boards are connected in a region of their opposite ends by the cables, wherein the opposite ends abut one another or at most face one another at a distance so slight as to be many times smaller than a length of a circuit board.

3. The lighting unit according to claim 1, wherein each of the circuit boards has at least two driver units, wherein a portion of the light-emitting diodes of each of the circuit boards is associated with each driver unit for control of the light-emitting diodes.

4. The lighting unit according to claim 3, wherein three circuit boards are present, wherein eighteen light-emitting diodes and three driver units are arranged on each of the three circuit boards, and wherein six light-emitting diodes are associated with each of the three driver units.

5. The lighting unit according to claim 1, wherein each circuit board has one driver unit, wherein all light-emitting diodes of the circuit board are associated with the driver unit for control.

6. The lighting unit according to claim 5, wherein nine circuit boards are present, and six light-emitting diodes that are associated with the driver unit for control are arranged on each of the nine circuit boards.

7. A motor vehicle comprising the lighting unit according to claim 1.

8. The lighting unit according to claim 1, wherein each of the circuit boards have a same radius of curvature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIGS. 1a and 1b show exemplary lighting units with different radii of curvature;

(3) FIGS. 2a and 2b show a representation of a different orientation of rigid, lined-up circuit boards in keeping with different radii of the lighting units; and

(4) FIG. 3 shows a section along section line I from FIG. 1a.

DETAILED DESCRIPTION

(5) FIG. 1a shows a first exemplary embodiment for a lighting unit 1, wherein the lighting unit 1 is arranged below a cover-like component 10.

(6) The cover-like component 10 is arranged in the region of a windshield W, of which only the shape of the visible surface is indicated.

(7) The lighting unit 1 extends over the entire length l of the cover-like component 10. The length l can run along a substantial portion of an instrument panel (not shown) in the region of the windshield W, for example.

(8) The lighting unit 1 has a long light guide 2 that likewise is curved in a crescent shape (see FIG. 2), to which three circuit boards 4 are attached, preferably snap-fitted.

(9) The circuit boards 4 are each placed together in the region of their ends such that they collectively follow the radius r1 of the lighting unit 1 or the curved shape of the light guide 2.

(10) Each of the circuit boards 4 is designed as a rigid circuit board, wherein all three circuit boards 4 have an identical radius r1.

(11) The circuit boards 4 abut one another at their opposite ends E and thus collectively form the desired radius r1.

(12) In the exemplary embodiment, each circuit board 4 has three driver modules T for control of light-emitting diodes 40 arranged on the circuit boards 4. In this design, one driver unit T controls exactly six light-emitting diodes 40 in each case. Consequently, a total of 54 light-emitting diodes can be controlled by the three circuit boards 4 that are lined up together and arranged in a crescent shape under a light input surface of the light guide 2.

(13) An angular offset a of light-emitting diodes 40, 40′ following one another successively in the longitudinal direction l (see FIG. 2) caused by different angular positions of the circuit boards 4 relative to one another can be compensated at the given points by a suitable change in thickness Δd of a body 20 of the light guide 2 in the region of the light input surface 21. In this regard, a light-emitting diode 40 in the section plane and a subsequent light-emitting diode 40′ with an angular offset a are shown in FIG. 3.

(14) In FIG. 2b, a line-up of the three circuit boards 4 in a somewhat tighter radius of curvature r2 is shown, such as is necessary for a more sharply curved lighting unit 1′ in a cover-like component 10′.

(15) As can be seen from FIG. 2b, the opposite ends E of two lined-up circuit boards 4 stand somewhat apart in order to achieve the radius of curvature r2. However, the distance is only slight and is many times smaller than a length of each individual circuit board 4.

(16) Departing from the exemplary embodiment, it is also possible that not just three rigid circuit boards 4, but instead even shorter, likewise rigid circuit boards are lined up with the light guide 2, to be precise preferably snap-fitted thereto (as shown in FIG. 2), and connected to one another, likewise by cables 3 (not shown in detail). Preferably it is possible in this design that nine circuit boards are joined together, and each circuit board has just one driver module T, with only six LEDs 40 associated with each of these for control.

(17) The advantage in the case of this solution resides in an increased flexibility of the arrangement, whereas the advantage of the line-up of only three circuit boards 4 resides in easier handling.

(18) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.