EP2386792A1 - LED light module - Google Patents

Abstract

The module (1) has a diffusion disk (3) arranged between LED-light sources (8, 9) and a lens (2). The disk has an opening (10) for direct passage of portion of light that is emitted from the light sources, where the direct portion of light that is discharged via the opening is projected via the lens for generating light function e.g. drive light function, in an area in front of a motor vehicle. The LED-light sources are designed as primary light sources i.e. infrared LED-light sources. Other LED-light sources (6, 7) are designed as secondary light sources i.e. high-power LED-light sources.

Description

The invention relates to an LED light module for a motor vehicle or for a headlight for a motor vehicle, wherein the light module comprises a lens and an LED light source.

Such an LED light source may be constructed of one or more light emitting diodes (LEDs) arranged to form a "common" light beam.

An initially mentioned light module consists essentially of one (or more) LED light source (s), e.g. in the form of a high-power light-emitting diode, and a lens, can be used to generate a light distribution which contains light components above the HD line in the generated light image. The thus realized light function (example: high beam, object lighting, ...) can be activated only in special driving situations, just then, if an object for illumination in front of the vehicle is present or the situation allows the switching on of the high beam.

Accordingly, such a light module is only rarely active, depending on the type (high beam, object lighting, ...) of the light module often only a few minutes per hour. Such a light module can therefore not be included in the design of the night design of the vehicle or the vehicle headlamp, i. E. the visible to the outside of the light module area appears at night, when the light module is not activated, dark, which is often perceived as unpleasant.

Due to the necessary for the realization of the light function design of the light module (high maximum illuminance, eg about 150 lux) and the corresponding limited possibility of reducing the LED light output, it is also not possible to operate the light function in a dimmed state, without the legally prescribed To exceed scattered light values.

It is an object of the invention to provide a solution to the above problem.

This object is achieved with a light module mentioned in the introduction, that according to the invention in the light exit direction between the LED light source and the lens a lens is arranged, wherein the lens at least one opening for the direct passage of at least a portion of the emitted light from the LED light source and wherein the direct component emerging through the opening of the lens the light emitted by the LED light source is projected via the lens to produce a light function in the area in front of the motor vehicle.

By providing a lens, the lens can be homogeneously illuminated, whereby the light from the primary light source can pass unhindered through the opening in the lens, so that the main light function is not affected.

It is possible in this way to incorporate the light module in the headlight design even when the light function is not activated by the lens is illuminated and accordingly, for example in the dark, the light module appears visually and does not appear dark.

In a specific embodiment of the LED light module according to the invention, it is provided that the LED light source is embodied as a primary light source whose substantially entire emitted, relevant luminous flux exits through the opening of the lens to produce the light function.

"Relevant" luminous flux is to be understood as the luminous flux which can enter via the light entry surface of the lens; This luminous flux thus includes those light rays which are emitted within the aperture angle of the lens from the LED light source. Depending on the embodiment, a light-emitting diode has a specific emission behavior, so that usually a portion of the light rays - unless it is deflected - is emitted in directions at angles which are greater than the opening angle of the lens, so that this light does not enter the lens and thus is basically usable for the light function. Light from the LED light source, which is radiated at a larger angle than the opening angle, no longer represents "relevant" luminous flux.

In a particularly advantageous embodiment of the invention, at least one further LED light source is provided as a secondary light source, which is arranged with respect to the opening of the lens so that the light emitted by the secondary light source is emitted substantially to the lens so that substantially no Luminous flux of the secondary light source exits through the opening of the lens.

Such an LED light source can be constructed from one or more light-emitting diodes (LEDs), which form a "common" light beam. The secondary light source can then - see below - be constructed from one or more such LED light sources.

In order to produce a homogeneously luminous surface, a diffusing screen (diffuse disk) is used which is illuminated by one or more additional LED light sources.

It can be provided that an axis by the LED light source of the primary light source and the opening of the lens forms the optical axis and that the at least one LED light source of the secondary light source is outside the optical axis.

In this way it can already be prevented in a simple manner that light exits the secondary light source through the opening of the lens, which would produce unwanted interference.

In order to achieve an optimum, as homogeneous as possible illumination of the lens or a homogeneous appearance as possible of the lens and thus the light module, may further be provided that the at least one LED light source of the secondary light source against the light exit direction, with respect to the primary Light source is arranged offset to the rear.

With increasing distance of the LED light source (s) of the secondary light source, a more homogeneous illumination of the lens is achieved.

In the sense of a homogeneous illumination of the lens, it is further if, as provided in an advantageous variant, the secondary light source comprises two or more LED light sources.

It is expedient if the LED light source of the primary light source and the at least one LED light source of the secondary light source can be controlled separately, so that the primary light source and the secondary light source can be switched on and off independently.

Furthermore, it is advantageous if - in the installed state of the light module in a vehicle headlight - the secondary light source of the light module in the vertical direction below a horizontal plane, which runs for example by the LED light source of the primary light source, n LED light sources and above the Horizontal plane has m LED light sources, where m <n.

Since the lens of the light module is mostly viewed from angles above this horizontal, it is advantageous if the number of LEDs in the lower area is increased, since this area is imaged in the angular range above the horizontal and so a more visually appealing illumination of the lens can be achieved.

Just as the optical axis of the lens does not necessarily have to pass through the LED or, in the case of several LEDs, through its geometric center, the horizontal plane does not necessarily have to pass through the primary LED light source, but can also be defined by the lens Direction may be shifted, which also changes the position of the image (angle).

Basically optimal would be a high number of LED light sources for the secondary light source, but this is limited by costs and available space of the spotlight. In a simple, favorable variant of the invention, with which appealing results can be achieved in the illumination of the lens / lens, m = 0.

In terms of the most uniform possible illumination, it is further, when the LED light source (s) above / below the horizontal plane are each arranged symmetrically in the horizontal direction with respect to a vertical plane through the optical axis / are.

In addition, it may be provided in this connection that further LED light sources of the secondary light source are arranged laterally next to the LED light source of the primary light source.

In order to make optimum use of the luminous flux from the LED light source of the primary light source, it is further provided with advantage that the dimensions of the opening in the lens, such as diameter, side dimensions, etc. and / or the arrangement of the LED light source Primary light source with respect to the opening of the lens and / or the distance of the LED light source of the primary light source to the lens are selected such that of the LED light source, which forms the primary light source, all emitted light rays, which within an opening angle of the lens can pass through the opening.

The size of the opening in the lens is dependent on the distance of the disc to the LED light source of the primary light source and can be derived from the opening angle of the lens. Since the aperture of the lens is imaged directly over the lens, it is advantageous to make this aperture as small as possible. In addition, the shape of the opening is preferably adapted to the shape of the lens trimming.

To minimize the size of the aperture, the lens is positioned as close as possible to the LED light source of the primary light source.

If the shape of the lens trimming is mentioned here, then it is of particular importance which shape the light entry surface of the lens has. This has a flat or curved surface with an example circular, (four-, right-) square, or depending on the application arbitrary shape, which shape is referred to here as "shape of the lens trimming". The shape of the opening is preferably identical in terms of proportions to the lens trimming.

The shape of the lens is preferably designed so that it is visible through the projection lens, viewed from the outside, from all viewing angles, so that a homogeneous appearance of the lens can be generated.

Furthermore, it is advantageous if the dimensions of the opening in the lens, such as diameter, side dimensions, etc. and / or the arrangement of the at least one LED light source of the secondary light source with respect to the opening of the lens and / or the distance the at least one LED light source of the secondary light source is selected to the lens so that emitted from the at least one LED light source, which forms the secondary light source, light rays only in areas of the lens, which have no opening.

In this way, no passage of secondary light through the opening of the lens can take place, which would cause undesirable effects.

In particular, it is advantageous if the dimensions of the opening in the lens, such as diameter, side dimensions, etc. and / or the arrangement of the at least one LED light source of the secondary light source with respect to the opening of the lens and / or the distance the at least one LED light source of the secondary light source to the lens are selected such that from the at least one LED light source, which forms the secondary light source, light rays are emitted to the edge of the opening of the lens.

The uniform illumination of the lens is essentially defined by 3 parameters: distance of the secondary LED light source (s) to the lens, number of light sources and arrangement of the light source about the optical axis of the lens, preferably in one or more planes behind the lens, to achieve the necessary distance of the secondary LED light sources to the lens.

In general, the homogeneity of the lens is directly proportional to the number of secondary LED light sources and the distance of the secondary LED light sources to the lens, wherein a uniform distribution of the secondary LED light sources is advantageous.

The limiting factor for these parameters is the space available for the light module. This results in certain optimized variants.

Furthermore, it can also be provided that the edge of the opening of the lens to the rear, directed in the direction of the primary light source, is tapered, e.g. trapezoidal in order to be optimally adapted to the beam path of the boundary rays of the primary light source (boundary rays are those light rays which impinge on the latter at the opening angle of the lens).

For example, the LED light source of the primary light source may be an infrared light source.

• Fig. 1 ein erfindungsgemäßes Lichtmodul in einem Vertikalschnitt entlang der optischen Achse des Moduls,
• Fig. 2 eine schematische Vorderansicht des Lichtmoduls in einer ersten Variante, und
• Fig. 3 eine weitere Variante eines Lichtmoduls nach der Erfindung in einer schematischen Vorderansicht.

In the following the invention is discussed in more detail with reference to the drawing. In this shows

• Fig. 1 a light module according to the invention in a vertical section along the optical axis of the module,
• Fig. 2 a schematic front view of the light module in a first variant, and
• Fig. 3 a further variant of a light module according to the invention in a schematic front view.

The Figures 1 and 2 show a first light module 1 according to the invention for a motor vehicle or for a headlight for a motor vehicle. The LED light module 1 comprises a lens 2 and an LED light source 8, 9, this LED light source consisting of a print 8 and a light-emitting diode 9. This LED light source can be a high-performance light-emitting diode, or it can also be an infrared light-emitting diode.

Between this LED light source 8, 9 and the lens 2, a lens 3 is arranged, wherein the lens 3 has an opening 10 for the direct passage of at least a portion of the light emitted from the LED light source 8, 9. This exiting through the opening 10 of the lens 3 direct share emitted by the LED light source 8, 9 Light is projected via the lens 2 to generate a light function in the area in front of the motor vehicle.

The LED light source 8, 9 is designed as a primary light source, the substantially entire emitted, relevant luminous flux through the opening 10 of the lens 3) exits to produce the light function. The light function is e.g. for high beam or for object lighting (e.g. pedestrian), which light function is accordingly activated only in special driving situations.

"Relevant" luminous flux is to be understood as the luminous flux which can enter via the light entry surface of the lens; This luminous flux thus includes those light rays which are emitted within the aperture angle of the lens from the LED light source. Depending on the embodiment, a light-emitting diode has a specific emission behavior, so that usually a portion of the light rays - unless it is deflected - is emitted in directions at angles which are greater than the opening angle of the lens, so that this light does not enter the lens and thus is basically usable for the light function. Light from the LED light source, which is radiated at a larger angle than the opening angle, no longer represents "relevant" luminous flux.

In addition, other LED light source 6, 7; 6 ', 7' (the reference numerals 6, 6 'denote the respective light-emitting diode, the reference numerals 7, 7 the associated LED prints), which together form a secondary light source which is arranged with respect to the opening (10) of the lens 3 such in that the light emitted by the secondary light source is emitted substantially onto the diffusing screen 3, so that essentially no, preferably no light flux of the secondary light source exits through the opening 10 of the diffusing screen 3.

With these additional LED light sources, the lens 3 can be illuminated, through which the lens can be homogeneously illuminated, through the opening in the lens, the light from the primary light source can pass unhindered, so that the main light function is not affected.

It is possible in this way to incorporate the light module in the headlight design even when the light function is not activated by the lens is illuminated and accordingly, for example in the dark, the light module appears visually and does not appear dark.

Due to the necessary for the realization of the light function design of the light module (high maximum illuminance, eg about 150 lux) and the corresponding limited possibility of reducing the LED light output, it is also not possible to operate the light function in a dimmed state, without the legally prescribed To exceed scattered light values.

Both the LED light source 8, 9 of the primary light source and the LED light sources 6, 7; 6 ', 7' of the secondary light source are mounted on a heat sink 4 with cooling fins 5. On the special shape of the heat sink will be discussed in more detail below.

As FIG. 1 can be seen, forms an axis through the LED light source 8, 9 of the primary light source and through the opening 10 of the lens 3, the optical axis 100. The additional LED light sources 6, 7; 6 ', 7' of the secondary light source are outside the optical axis 100.

In this way it can already be prevented in a simple manner that light exits the secondary light source through the opening of the lens, which would produce unwanted interference.

In order to achieve an optimal, homogeneous illumination of the lens or homogeneous as possible appearance of the lens and thus the light module is also provided that the LED light sources 6, 7; 6 ', 7' of the secondary light source opposite to the light exit direction, with respect to the primary light source 8, 9 is arranged offset to the rear. With increasing distance of the LED light source (s) of the secondary light source, a more homogeneous illumination of the lens is achieved.

Accordingly, the heat sink 4 has a front plane to which the primary LED light source 8, 9 is mounted and another, recessed plane for the secondary LED light sources 6, 7; 6 ', 7'. In the variant shown, only one such plane is provided for the secondary LED light sources, but in principle two or more such planes may also be provided.

From the level for the secondary LED light sources there is a quasi dome on which the plane for the primary LED light source is located. Of course, this dome also affects the light emitted by the secondary LED light sources, as discussed below.

The LED light source 8, 9 of the primary light source and the LED light sources 6, 7; 6 ', 7' of the secondary light source can be controlled separately, so that the primary light source and the secondary light source can be switched on and off independently of each other.

In the installed state of the light module in a vehicle headlight, the secondary light source of the light module in the vertical direction below a horizontal plane 101 by the LED light source of the primary light source n LED light sources 6 ', 7' and above the horizontal plane m LED light sources 6, 7, where m <n.

This is in FIG. 2 to recognize where n = 3 and m = 1, and further in FIG. 2 , with m = 0 and n = 3.

The LED light source (s) above and below the horizontal plane 101 are each arranged symmetrically in the horizontal direction with respect to a vertical plane through the optical axis 100.

In addition, further LED light sources 6 ', 7' of the secondary light source are arranged laterally next to the LED light source 8, 9 of the primary light source, namely in the concrete example in FIG FIG. 2 respectively. FIG. 3 one to each side.

In order to optimally use the luminous flux from the LED light source 8, 9 of the primary light source, it is provided that the dimensions of the opening 10 in the lens 3, such as diameter, side dimensions, etc., and the distance of the LED light source 8, 9 of the primary light source are selected to the lens 3 such that of the LED light source 8, 9, which forms the primary light source, all emitted light rays, which are within an opening angle of the lens 2, pass through the opening 10 can. The rays emitted by the primary LED light source, which just reach the aperture angle of the lens, ie which are just left through by the aperture 10, are denoted by S1 ( FIG. 1 ).

The size of the opening in the lens is dependent on the distance of the disc to the LED light source of the primary light source and can be derived from the opening angle of the lens. Since the aperture of the lens is imaged directly over the lens, it is advantageous to make this aperture as small as possible. In addition, the shape of the opening is preferably adapted to the shape of the lens trimming.

To minimize the size of the aperture, the lens is positioned as close as possible to the LED light source of the primary light source.

The shape of the lens is preferably designed so that it is visible through the projection lens, viewed from the outside, from all viewing angles, so that a homogeneous appearance of the lens can be generated.

In addition, it is provided that the dimensions of the opening 10 in the lens 3, such as diameter, side dimensions, etc. and / or the arrangement of the LED light sources 6, 7; 6 ', 7' of the secondary light source with respect to the opening 10 of the lens 3 and / or the distance of the LED light sources 6, 7; 6 ', 7' of the secondary light source are selected to the lens 3 such that of the LED light sources 6, 7; 6 ', 7', which form the secondary light source, light beams only in areas of the lens 3, which have no opening 10, are emitted.

In this way, no passage of secondary light through the opening of the lens can take place, which would cause undesirable effects.

As in FIG. 1 it is particularly useful if the dimensions of the opening 10 in the lens 3, such as diameter, side dimensions, etc. and / or the arrangement of the LED light sources 6, 7; 6 ', 7' of the secondary light source with respect to the opening 10 of the lens 3 and / or the distance of the LED light sources 6, 7; 6 ', 7' of the secondary light source are selected to the lens 3 such that of the LED light sources 6, 7; 6 ', 7', which form the secondary light source, light rays are emitted to the edge of the opening 10 of the lens 3.

FIG. 1 shows those rays S2 of the secondary LED light sources 6, 7; 6 ', 7', which just reach the edge of the opening 10, rays which are radiated at an even greater angle and could escape through the opening 10 are already through the heat sink, ie through the dome, on which the primary light source sits, depending on the surface texture of the heat sink or its dome absorbed or (diffused) reflected.

The distance between the secondary LED light sources to the dome of the heat sink 4 must be in direct proportion to the distance of the secondary LED light sources to the lens, otherwise too large shading effects occur through the dome. Slight shading by the dome can be compensated by the light guide effect in the lens.

The tuning, such as the secondary LED light sources 6, 7; 6 ', 7' are to be arranged on the heat sink, on the one hand to achieve a maximum and uniform illumination of the lens 3 without light passes through the opening 10, of course, also depends on the geometry of the heat sink 4.

The uniform illumination of the lens is essentially defined by 3 parameters: distance of the secondary LED light source (s) to the lens, number of light sources and arrangement of the light source about the optical axis of the lens, preferably in one or more planes behind the lens, to achieve the necessary distance of the secondary LED light sources to the lens.

In general, the homogeneity of the lens is directly proportional to the number of secondary LED light sources and the distance of the secondary LED light sources to the lens, wherein a uniform distribution of the secondary LED light sources is advantageous.

The limiting factor for these parameters is the space available for the light module. This results in certain optimized variants, such as those in FIG. 1 graduated arrangement of LED light sources.

The secondary LED light sources could also be positioned in a plane with the primary LED light source. As a result, a homogeneous luminous impression can be realized even with a small number of LEDs. In this case, however, the lens should be curved forward or obliquely forward.

Claims (15)

LED light module (1) for a motor vehicle or for a headlight for a motor vehicle, wherein the light module (1) comprises a lens (2) and an LED light source (8, 9),
characterized in that
Seen in the light exit direction between the LED light source (8, 9) and the lens (2) a lens (3) is arranged, wherein the lens (3) at least one opening (10) for the direct passage of at least a portion of the LED Light source (8, 9) emitted light, and wherein the through the opening (10) of the lens (3) emerging direct component of the light emitted from the LED light source via the lens (2) for generating a light function in the area before Motor vehicle is projected. LED light module according to claim 1, characterized in that the LED light source (8, 9) is designed as a primary light source whose substantially total emitted, relevant luminous flux through the opening (10) of the lens (3) for generating the light function exit. LED light module according to claim 1 or 2, characterized in that at least one further LED light source (6, 7; 6 ', 7') is provided as a secondary light source, which with respect to the opening (10) of the lens (3) arranged that the light emitted from the secondary light source is substantially emitted to the lens (3), so that substantially no luminous flux of the secondary light source through the opening (10) of the lens (3) emerges. LED light module according to claim 3, characterized in that an axis through the LED light source (8, 9) of the primary light source and the opening (10) of the lens (3) forms the optical axis (100) and that the at least one LED light source (6, 7; 6 ', 7') of the secondary light source is outside the optical axis (100). LED light module according to claim 3 or 4, characterized in that the at least one LED light source (6, 7; 6 ', 7') of the secondary light source opposite to the light exit direction, with respect to the primary light source is arranged offset to the rear , LED light module according to one of claims 3 to 5, characterized in that the secondary light source comprises two or more LED light sources. LED light module according to one of claims 3 to 6, characterized in that the LED light source (8, 9) of the primary light source and the at least one LED light source (6, 7; 6 ', 7') of the secondary light source are controlled separately. LED light module according to one of claims 3 to 7, characterized in that - in the installed state of the light module in a vehicle headlight - the secondary light source of the light module in the vertical direction below a horizontal plane, which extends for example by the LED light source of the primary light source , n LED light sources (6 ', 7') and above the horizontal plane m LED light sources (6, 7), where m <n holds. LED light module according to claim 8, characterized by m = 0. LED light module according to claim 8 or 9, characterized in that the LED light source (s) above or below the horizontal plane is in each case arranged symmetrically in the horizontal direction with respect to a vertical plane through the optical axis (100) / are. LED light module according to one of claims 8 to 10, characterized in that laterally next to the LED light source (8, 9) of the primary light source further LED light sources (6 ', 7') of the secondary light source are arranged. Light module according to one of claims 1 to 11, characterized in that the dimensions of the opening (10) in the lens (3), such as diameter, side dimensions, etc. and / or the arrangement of the LED light source (8, 9) of Primary light source with respect to the opening (10) of the lens (3) and / or the distance of the LED light source (8, 9) of the primary light source to the lens (3) are selected such that of the LED light source (8, 9), which forms the primary light source, all emitted light rays which are within an opening angle of the lens (2) can pass through the opening (10). Light module according to one of claims 3 to 13, characterized in that the dimensions of the opening (10) in the lens (3), such as diameter, side dimensions, etc. and / or the arrangement of the at least one LED light source (6, 7 6 ', 7') of the secondary light source with respect to the opening (10) of the lens (3) and / or the distance of the at least one LED light source (6,7; 6 ', 7') of the secondary light source to the lens (3) are selected such that of the at least one LED light source (6, 7; 6 ', 7'), which forms the secondary light source, light rays only in areas of the lens (3), which no opening (10) are emitted. Light module according to claim 13, characterized in that the dimensions of the opening (10) in the lens (3), such as diameter, side dimensions, etc. and / or the arrangement of the at least one LED light source (6, 7, 6 ', 7 ') of the secondary light source with respect to the opening (10) of the lens (3) and / or the distance of the at least one LED light source (6, 7; 6', 7 ') of the secondary light source to the lens ( 3) are selected such that from the at least one LED light source (6, 7, 6 ', 7'), which forms the secondary light source, light rays are emitted to the edge of the opening (10) of the lens (3) , Light module according to one of claims 1 to 14, characterized in that the LED light source (8, 9) of the primary light source is an infrared light source.

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