EP3260764A1

EP3260764A1 - Compact lighting device for vehicles

Info

Publication number: EP3260764A1
Application number: EP17176856.7A
Authority: EP
Inventors: Pablo RODRÍGUEZ ORTEGA
Original assignee: Automotive Lighting Italia SpA
Current assignee: Marelli Automotive Lighting Italy SpA
Priority date: 2016-06-20
Filing date: 2017-06-20
Publication date: 2017-12-27
Anticipated expiration: 2037-06-20
Also published as: EP3260764B1; CN107525002B; CN107525002A; ITUA20164515A1

Abstract

Lighting device (1) comprising a LED light source (2) and an optical system (3) for collecting and distributing according to a desired photometric profile a light beam produced by said LED light source; wherein the optical system comprises: a refractive lens (5) arranged in front of the LED light source and in a distal position from the LED light source; and a collimator element (6) arranged in a position close to the LED light source and designed to concentrate the light beam in a focal point (F) arranged between the collimator element and the refractive lens and lying on an optical axis (X) connecting the centre line of the collimator element with the centre line of the refractive lens.

Description

Technical field of the invention

The invention relates to a lighting device for vehicles, which, in particular, is compact and efficient and can be manufactured as one or more modules that can be combined with one another.

Prior art

The currently most requested lighting devices for vehicles are LED light devices, both because of their cost-effectiveness and because of their efficiency. However, these devices are relatively bulky and not very flexible and, therefore, users have started requesting customized devices for each desired lighting function; furthermore, known devices are very complex in their structure and often require large reflecting elements as well as other similar components.

Summary of the invention

An object of the invention is to provide a lighting device for vehicles, which that is not too bulky and is simple as well as economic to be produced. A further object of the invention is to provide a modular lighting device, which can easily be set up to so as to fulfil different lighting functions.
Therefore, according to the invention, a lighting device is provided, which has the features set forth in the appended claims.

Brief description of the Drawings

Further features and advantages of the invention will be best understood from the following description of two non-limiting embodiments thereof, done with reference to the figures of the accompanying drawings, wherein:

figure 1 shows an exploded perspective view of a lighting device according to the invention, which makes up one single module, which can be coupled to other similar or identical modules;
figure 2 shows an assembled and longitudinally sectional perspective view of the lighting device or module of figure 1;
figure 3 schematically shows the operating principle of the lighting device or module of figures 1 and 2;
figure 4 shows a front three-quarter perspective view; of a modular lighting device comprising three devices or modules like the one of figures 1 and 2;
figure 5 shows a rear three-quarter exploded view of the modular lighting device of figure 4; and
figure 6 shows, on a larger scale, a rear three-quarter perspective view of the lighting device or module of figures 1 and 2.

Detailed description

With reference to figures 1 to 3 and 6, number 1 indicates, as a whole, a lighting device for vehicles comprising at least a LED light source 2 and an optical system 3 for collecting and distributing according to a desired photometric profile, which is known and not shown for the sake of simplicity, a light beam 4 produced by the LED light source 2.
According to the main aspect of the invention, the optical system 3 is especially compact and innovative and it comprises a refractive lens 5 arranged in front of the LED light source 2 and in a distal position from the LED light source 2; and a collimator element 6 arranged in a position close to, and substantially at, the LED light source 2. The collimator element, as it will be explained more in detail hereinafter, is designed to collect the entire light beam 4 (figure 3) emitted by the light source 2 in order to then concentrate the light beam 4 in a focal point F arranged between the collimator element 6 and the refractive lens 5, said focal point F lying on an optical axis X connecting the centre line of the collimator element 6 (i.e. the geometric centre of the collimator 6) with the centre line of the refractive lens 5 (i.e. the geometric centre of the refractive lens 5).
The lighting device 1 preferably comprises, furthermore, a relief 7, an upper edge 8 of which is arranged immediately under the optical axis X connecting the centre line of the collimator element 6 with the centre line of the refractive lens 5 and is further arranged at the focal point F, in particular in the same axial position as the focal point F and immediately under the latter. The edge 8 is spaced apart from the focal point F by a very small gap, for example two order of magnitude smaller than the distance between the lens 5 and the collimator element 6 measured along the axis X, and is designed to define, when necessary, a light and dark cut-off line of the desired photometric profile, which is known and not shown for the sake of simplicity.
The collimator element 6 is defined by a solid block of light-pervious material, for example a block of transparent polymer material, and is laterally delimited, namely all around the axis X, by a lateral wall 9 thereof, for example with a parabolic shape, delimiting a total internal reflection surface 10 towards the light source 2.
The solid block of light-pervious material defining the collimator element 6 is further frontally delimited, at a first end 11 directed towards the LED light source, by a first lens 12 (figure 3) arranged on the optical axis X and which faces an internal cavity 13 of the block of light-pervious material, said cavity 13 being obtained in the end 11 and surrounding the LED light source 2; in particular, the lens 12 defines a bottom wall of internal cavity 13, which has for the rest, for example, a substantially cylindrical shape.
The solid block of light-pervious material defining the collimator element 6 is further frontally delimited, at a second end 14 thereof opposite the first end 11, by a second lens 15 arranged on the optical axis X, coaxial with the first lens 12 and aimed towards, as well as facing to, the refractive lens 5.
The first lens 12 is convex towards the light source 2 and extends/projects inside the cavity 13, while the second lens 15 can be either concave or convex towards the refractive lens 5. In this way, the light emitted by the light source 2, up to a given angle, is collected by the lens 12, causing a diffraction. For greater angles, the light is transmitted through the surface 13, thus reaching the surface 10. The light collected with the lens 12 and the one obtained from a total reflection due to the surface 10 are directed towards the lens 14 and focused by the lens 14 in the focal point F; from the focal point F the light beam 4 widens and is collected by the refractive lens 5.
The refractive lens 5 is delimited by a first frontal surface 16, through which the optical axis X passes and directed towards the opposite side to the LED light source 2, said first frontal surface 16 defining an aesthetic profile of the refractive lens 5, and by a second frontal surface 17 through which the optical axis X passes and directed towards the LED light source.
The second frontal surface 17 defines a continuous paraboloid calculated as a function of the profile of the first frontal surface 16 and of the desired photometric profile.
According to the preferred - though non-limiting - embodiment shown, the lighting device 1 described herein structurally comprises a printed circuit board 18 that carries at least a LED 19 making up the light source 2; the LED 19 is carried, in an integral fashion, by a first face 20 of the printed circuit board 18 facing the cavity 13; on the other hand, a second face 21 of the printed circuit board 18, opposite the face 20, carries, in an integral and cantilever fashion, a heat disperser 22 and a block of respective electrical contacts 23, for example pin electrical contacts, arranged beside one another.
The collimator element 6 already described above is provided with at least two opposite lateral flanges 24 (figure 1) by means of which it is fixed integral to the first face 20 of the printed circuit board 18, in front of the at least a LED 19; in this way, the collimator element 6 and the light source 2 make up an independent self-supporting unit.
The refractive lens 5, which is obviously made of a light-pervious material, preferably a synthetic plastic material, is provided at the rear, towards the collimator element 6, with at least a pair of arms 25 that extend parallel to the optical axis X and towards the printed circuit board 18, thus defining a fork element with the refractive lens 5.
The lighting device 1 is structurally completed by a supporting body 26 formed by a first and a second half-shell, indicated with 27 and 28 respectively, having respective concavities 29 facing one another and coupled so as to be on top of one another on the side of the concavities 29.
The half- shells 27 and 28, by being coupled to one another, for example in an interlocking manner and/or by means of screws or other removable connection means, clamp together the printed circuit board 18 with the collimator element 6 at a first cup-shaped rear end 30 of the half-shells, and the arms 25 of the refractive 5 lens at a second front end 31 of the half-shells, which has a disc shape and, because of the presence of the concavity 29, is substantially shaped like a pan.
In particular, the printed circuit board 18 with the collimator element 6 and the arms 25 are arranged inside the concavities 29 of the respective ends 30 and 31 and then the half- shells 27 and 28 are coupled on top of one another, thus locking the printed circuit plate 18, the collimator element 6 and the arms 25 with the lens 5 in the respective requested relative positions in a precise manner; furthermore, when the half- shells 27, 28 are coupled, the refractive lens 5 is supported in a cantilever fashion by the front ends 31, immediately in front of them and axially separated from the ends 31.
Finally, the two pan-shaped front ends 31 of the half- shells 27, 28 define between them, with their concavities 29 coupled, a protected propagation channel 32 (figure 2) for the light beam 4 between the collimator element 6 and the refractive lens 5, containing the focal point F and coaxial with the optical axis X. The channel 32 is further open towards the refractive lens 5, which is spaced apart from its outlet in the area of the front edge of the ends 31.
The first lower half-shell 27 is internally provided, when needed, in the concavity 29 and on the pan-shaped front end 31, with a transverse relief 7, which is arranged between the arms 25 of the refractive lens 5, immediately under the optical axis X and at the focal point F, so as to define, with its upper edge 8, a light and dark cut-off line of the desired photometric profile.
In this way, the lighting device 1 described herein makes up, once the half- shells 27, 28 are assembled, an independent self-supporting module, which is provided with the contacts and all the necessary operating components.
Since, in order to obtain the desired photometric profile, in particular in order to carry out optical functions, such as the ones of a low beam, one single LED 19 cannot be enough, or in case users want to obtain different optical functions together, for example daytime running light, position light, etcetera, the invention also relates to a modular lighting device 37 for vehicles, shown in figures 4 and 5, comprising a plurality of, in the example three, independent and self-supporting modules 1, each of which consists of a lighting device 1 described above, is identical to the others or is provided with one or more LEDs 18, the lens 5 and the collimator element 6 so as to be different from the others, and is provided with or lacks the relief 7. The modules 1 are mutually arranged with their optical axes parallel and are grouped together in a single functional unit by means of a first frame element 33 and a second frame element 34, which are mechanically coupled to each other in a direction parallel to the optical axis X of each device or module 1, so as to form a box-like support 35, from which the modules 1 axially project in a cantilever fashion.
In particular, the frame elements 33 and 34 clamp together, in the direction of the optical axis X, respective rear ends of each module 1 defined by the ends 30 of the half- shells 27, 28, allowing respective front ends of the modules 1, defined by the ends 31 of the half- shells 27, 28 and each provided, in turn, in a cantilevered fashion with a refractive lens 5, to project frontally in a cantilever fashion from the first front frame element 33.
The second rear frame element 34 is provided, on the opposite side to the first frame element 33, with a plurality of tubular projections 36, within each of which a block of adjacent contacts 23 is coupled through insertion, the contacts projecting at the rear in a cantilever fashion from the printed circuit board 18 of each module 1; the contact block 33 inserted inside a respective tubular projection 36 forms a standard electrical connector to connect the lighting devices or modules 1, namely the modular lighting device 37 to the control circuit of a vehicle.
Furthermore, figure 4 schematically shows a vehicle headlight or lamp 38 comprising at least a lighting device or module 1 or a modular lighting device 37 consisting of different modules 1 housed inside a cup-shaped casing 39 and designed to be mounted on a vehicle, and a transparent cover 40 that closes at the front the cup-shaped casing 39 and through which the lighting device 1 or 33 is visible from the outside.
Owing to the above, one can obtain a lighting device that is not too bulky and uses all the light generated by the light source, also in case of photometric profiles including a cut-off, thus enabling an improvement of the optical performances with the same energy consumptions; as a matter of fact, the relief 7 with its edge 8 is only used to define the shape of the light and dark cut-off line, but it does not intercept the light beam 5, which, therefore, is entirely used. Furthermore, by coupling different modules 1 in a single modular device 37, one can easily obtain numerous optical configurations, at the same time ensuring a high standardization of shapes and structural parts, with consequent remarkable savings in terms of costs and simplification of the production.
Therefore, all the objects of the invention are reached.

Claims

Lighting device (1;33) for vehicles, comprising at least a LED light source (2) and an optical system (3) for collecting and distributing according to a desired photometric profile a light beam (4) produced by said LED light source; characterised in that the optical system comprises:
- a refractive lens (5) arranged in front of the LED light source and in a distal position from the LED light source (2);

- a collimator element (6) arranged in a position close to, and substantially at, the LED light source (2) and designed to concentrate the light beam (4) in a focal point (F) arranged between the collimator element and the refractive lens and lying on an optical axis (X) connecting the centre line of the collimator element (6) with the centre line of the refractive lens (5).
Lighting device according to claim 1, characterised in that it also comprises a relief (7), an upper edge (8) of which is arranged immediately under the optical axis (X) connecting the centre line of the collimator element with the centre line of the refractive lens and at the focal point (F) and is designed to define a light and dark cut-off line of the desired photometric profile.
Lighting device according to claim 1 or 2, characterised in that the collimator element (6) is defined by a block of light-pervious material delimited laterally by a total internal reflection surface (10) and frontally, at a first end (11) directed towards the LED light source, by a first lens (12) arranged on the optical axis and which faces an internal cavity (13) of the block of light-pervious material, said cavity surrounding the LED light source; and, at a second end (14) opposite the first, by a second lens (15) arranged on the optical axis, coaxial with the first lens (12), the second lens (15) being aimed towards and facing the refractive lens (5).
Lighting device according to claim 3, characterised in that the first lens (12) is convex towards the light source and extends inside said cavity (13) of the block of light-pervious material, while the second lens (15) is either concave or convex towards the refractive lens (5).
Lighting device according to claim 4, characterised in that the refractive lens (5) is delimited by a first frontal surface (16), through which the optical axis passes and directed towards the opposite side to the LED light source, said first frontal surface defining an aesthetic profile of the refractive lens, and by a second frontal surface (17) through which the optical axis passes and directed towards the LED light source, the second frontal surface (17) defining a continuous paraboloid calculated as a function of the profile of the first frontal surface (16) and of the desired photometric profile.
Lighting device according to any one of the preceding claims, characterised in that it comprises: a printed circuit board (18) that carries at least a LED (19) on a first face (20) thereof and a heat disperser (22) and respective electrical contacts (23) on a second face (21) thereof, opposite the first; said collimator element (6), which is provided with at least two opposite lateral flanges (24) by means of which it is fixed integral to the first face (20) of the printed circuit board, in front of the at least a LED; said refractive lens (5), which is made of a light-pervious material, preferably a synthetic plastic material, and is provided at the rear, towards the collimator element, with at least a pair of arms (25) that extend parallel to the optical axis and towards the printed circuit board (18); and a supporting body (26) formed by a pair of half-shells (27,28) having respective concavities (29) mutually facing and coupled superimposed on each other so as to clamp together the printed circuit board (18) with the collimator element (6) at a first cup-shaped rear end (30) of the half-shells, and the arms (25) of the refractive lens at a second pan-shaped front end (31) of the half-shells and that supports in a cantilever fashion, immediately in front of the front end (31), the refractive lens (5); the two front ends (31) of the pan-shaped half-shells defining between them, with their concavities (29) coupled, a protected propagation channel (32) for the light beam (4) between the collimator element and the refractive lens, containing the focal point (F), the channel being coaxial with the optical axis (X) and open towards the refractive lens.
Lighting device according to claim 6, characterised in that a first lower half-shell (27) is provided internally, on the pan-shaped front end (31), with a transverse relief (7) arranged between the arms (25) of the refractive lens, immediately under the optical axis (X) and at the focal point (F), to define a light and dark cut-off line of the desired photometric profile.
Modular lighting device (37) for vehicles comprising a plurality of independent and self-supporting modules (1), each consisting of a lighting device according to any one of the preceding claims, the modules (1) being mutually arranged with their optical axes parallel, characterised by comprising a first (33) and a second (34) frame element mechanically coupled to each other in a direction parallel to the optical axis to form a box-like support (35) and that clamp together, in the direction of the optical axis, respective rear ends (30) of each module (1) allowing respective front ends (30) of the modules, each provided in a cantilevered fashion with a said refractive lens (5), to project frontally in a cantilever fashion from the first front frame element (33).
Modular lighting device according to claim 8, characterised in that the second rear frame element (34) is provided on the opposite side to the first frame element (33) with a plurality of tubular projections (36) within each of which a block of adjacent contacts (23) couple by insertion, the contacts projecting at the rear in a cantilever fashion from a printed circuit board (18) of a respective module (1) that carries on the opposite side the at least a LED light source (2), the block of contacts (23) inserted inside the tubular projection (36) forming an electrical connector.
Vehicle headlight or lamp (38) characterised in that it comprises at least a lighting device (1) according one of claims 1 to 7 or a modular lighting device (37) according to claim 8 or 9, housed inside a cup-shaped casing (39) and designed to be mounted on a vehicle and a transparent cover (40) that closes at the front the cup-shaped casing and through which said lighting device is visible from the outside.
Vehicle comprising a headlight or lamp according to claim 10.