The invention relates to a lighting device for a motor vehicle headlight for generating a light pattern, in particular an adaptive light pattern, e.g. an adaptive dipped headlight and main beam light pattern, or a part of such a light pattern, wherein the lighting device comprises a number N of projection modules, with N=2, 3, 4 or greater than 4, wherein each of the projection modules is configured to generate a segment light pattern, wherein a segment light pattern of several light segments is formed, and wherein the light segments of the segment light pattern lie in two or more substantially horizontal lines and in two or more columns, wherein the light segments lie in such a way that on activation of all light segments of the segment light pattern between the lines and the columns substantially no dark or light strips are formed, and wherein each light segment of the segment light pattern can be activated or deactivated independently of the other segments of the segment light pattern, and wherein in each line several segments, the so-called main segments, have identical main segment width, BR, and wherein all the projection modules are configured identically from an optical point of view.
The invention further relates to a motor vehicle headlight with at least one such lighting device.
The term “segment light pattern” is to be understood to mean a segmented light pattern, as is known from the prior art, in which the light pattern is to be understood of several light segments, which are arranged over one another, in columns, and adjacent to one another, in lines. The individual light segments can be switched on or off independently of the other light segments of the light pattern; provision can also be made that the individual light segments are dimmable, in particular are dimmable independently of the other light segments.
If the concern here is with light segments or light patterns which can be switched on or off or dimmed, then it is to be understood for the specialist in the art that for this, as a general rule, the respective light source(s) which is or respectively are used for the generation of the respective light segment (or of the light pattern), are switched on or off or dimmed.
The higher the number of light segments in horizontal direction, therefore within the lines, the higher the resolution is in horizontal direction. The same applies for the number of light segments in vertical direction, therefore in the columns, and the resolution in vertical direction.
An “arrangement in columns” is understood to mean that light segments of a column of a segment light pattern lie directly one over another in the sense that they are not offset laterally (horizontally) to one another, and all the light segments of a column have identical width. Equally, all the light segments of a line of a segment light pattern have the same height and lie directly adjacent to one another in the sense that they are not offset with respect to one another in vertical direction.
Projection modules for the generation of segmented light patterns are known from the prior art, in which the light segments are spaced apart from one another in the lines, i.e. two light segments of a line are respectively separated from one another by a non-illuminated region.
In the present invention, on the other hand, projection modules come into use in which the light segments which are generated with the projection module lie adjacent to one another or slightly overlap one another, both within the lines, therefore also between the lines. Frequently in such projection modules narrow, dark, more rarely light, strips occur between the individual light segments, which strips form a grid-like structure in the light image of a projection module. This can be desired, but is generally undesired, thus also in the present invention. The specialist in the art knows solutions in order to prevent such a grid structure in a segmented light image.
In currently used projection modules, which generate such a segmented light pattern, which serve for example for the generation of a fully-fledged adaptive dipped headlight and/or main beam and/or motorway light, or generally an adaptive light pattern which can switch over between main beam and dipped headlight depending on the situation, if applicable can also generate a motorway light, and/or according to the situation can block out regions in front of the vehicle to prevent the dazzling of vehicles which are driving ahead or vehicles in the oncoming traffic despite the operation of the main beam, the desired performance with respect to resolution, light flux and maximum of the light pattern can meet the requirements of the customers. However, the projection modules which are used for this are comparatively large, for example the projection lenses of such projection modules have dimensions of ca. 80 mm×50 mm.
However, modern headlight designs increasingly require smaller, in particular flat projection modules with overall heights of <25 mm or frequently even <20 mm.
In addition, from the customers' side, different requirements and wishes frequently exist for the light output and with regard to the resolution of such motor vehicle headlights.
It is an object of the invention to indicate a solution as to how segmented light patterns can be generated, in particular for the generation of an adaptive light pattern, in particular by means of flat projection modules.
This problem is solved with a lighting device mentioned in the introduction in that according to the invention the projection modules are arranged with respect to one another in such a manner that, proceeding from a first projection module, the so-called starting projection module, which generates a so-called starting segment light pattern, the segment light patterns of the further projection modules are displaced laterally in a, particularly in a common, horizontal direction, with the extent of the displacement, VSh, of the nth segment light pattern of the nth projection module (20) in said horizontal direction being proportional to (n−1)/N times the main segment width, BR, where n=2, . . . , N, and with at least one of the nth segment light patterns, n=2, . . . , N being displaced upwards or downwards vertically in respect of the starting segment light pattern.
The term “optically identical” in the present context is preferably understood to mean that two modules, in particular projection modules, which are “optically identical”, with arrangement at identical position and with identical alignment, form identical light patterns, wherein in particular also the individual light segments of the projection modules are configured identically, lie at identical location in the light pattern and have the same light values (light pattern, brightness, etc.).
This can be achieved in particular in that the modules are configured identically, preferably identically in construction.
With the solution according to the invention, in which two or more projection modules are used for the generation of the light pattern, smaller projection modules can be used, which together deliver the necessary amount of light, can be flexibly arranged, and through the overlaying, according to the invention, of the segment light patterns, an adaptive light pattern with desired resolution can be provided, which depending on the projection modules which are used can also jointly generate various light patterns (dipped headlight, main beam, motorway light, partial main beam).
The greater the number of installed projection modules in a lighting device here, the higher the achievable resolution, the achievable maximum illumination intensity [lx] or respectively the light intensity [cd] and the generated light flux can be.
Advantageous embodiments of the invention are presented more closely below.
In practice, provision can be made e.g. that the nth segment light pattern is displaced in the horizontal direction by a value VSh(n)=(n−1)/N×BR, n=2, . . . , N.
Provision can also be made that the nth segment light pattern is displaced in horizontal direction by a value VSh(n)=m×BR+(n−1)/N×BR, n=2, . . . , N, m=0, 1, or 2, or 3, or greater than 3.
Whereas in the former case the segment light patterns are only slightly displaced, so that a high resolution results over approximately the entire width of the thus generated total light pattern (wherein the resolution naturally further depends additionally on the number N), in the second case each displaced light pattern, compared to the first case, is additionally displaced by an entire main segment width, or by 2 main segment widths, etc. In this way, the total width of the light pattern can be increased.
Furthermore, provision can be made that all the nth segment light patterns, n=2, . . . , N, are displaced in vertical direction in respect of the starting segment light pattern by the same amount and in the same direction, preferably vertically upwards.
Whereas therefore in horizontal direction all the segment light patterns are displaced by different values, in vertical direction all the displaced segment light patterns can be displaced by the same amount.
Provision can be made that in vertical direction at least one of the segment light patterns is arranged in such a way that light segments at least of a line beginning at a straight line lying beneath in the H-H line in the light image extend downwards, and the light segments at least of a line of the light segments from the straight line extend upwards, wherein the straight line lies preferably 0.57° beneath the line H-H.
With the line lying beneath 0.57° accordingly a dipped headlight light pattern or a region lying at the light-dark threshold of the dipped headlight light pattern are illuminated.
The other segment light patterns can be displaced in vertical direction in such a way that a separation line lies between two lines of light segments of the other light patterns above the straight line, wherein preferably the separation line lies beneath the H-H line, preferably 0.23° beneath the H-H line.
In this way e.g. a motorway light light pattern can be generated. For example, for this, all light segments of the segment light patterns under from 0.57° and beneath 0.23° are activated, so that compared to a dipped headlight light pattern, the light-dark threshold is raised to −0.23°. If applicable, (in the case of right-hand traffic) for the right edge of the carriageway also some main beam light segments, i.e. light segments which lie above these threshold lines of −0.57° and −0.23°, can be activated.
For example, the light segments of a segment light pattern are configured to be substantially square or preferably substantially rectangular.
Preferably, provision is made that light segments of a segment light pattern which lie entirely beneath the H-H line, in particular beneath one of the straight lines, have a smaller height, therefore a smaller extent in vertical direction, than light segments lying thereabove.
The vertically “short” light segments lie at the bottom in the light image, whereas the “longer” light segments, especially in the middle of the light pattern (i.e. around the region HV) realize a desired run-out of the main beam light pattern upwards.
In an embodiment, provision is made that all the light segments of a segment light pattern have identical width, namely the main segment width, BR.
In another embodiment, provision is made that the light segments of a line of a segment light pattern have different width, wherein preferably light segments which lie centrally in the region of the line V-V have a first width BR, and light segments which, viewed laterally, lie in horizontal direction, have a second width BR′.
For example, this central region extends horizontally towards the left and right from the line V-V (which lies horizontally at 0°) over a range of −30° to +30°, or over a range of −20° to +20°, or over a range of −15° to +15°.
In particular, provision is made that a width of a light segment which jointly with one or more light segments of a segment light pattern lies centrally adjacent to one another approximately in the region of the line V-V, defines the main segment width, BR.
Usually, the central region of the light pattern around the point HV is more important than the edge regions, so that preferably this region is also used for the determining of the displacement of the segment light patterns.
Preferably, provision is made that the second width for the edge regions is greater than the first width in the central region.
In particular, provision can be made that the light segments of a segment light pattern lie symmetrically in respect of the V-V axis in the light image. The light segments of a segment light pattern of a half of a line are in this case mirrored about the axis V-V.
Preferably, provision is made that the projection modules respectively have an optical axis, and wherein a displacement of a segment light pattern in respect of the starting segment light pattern is produced in that the optical axis of the projection module generating the displaced segment light pattern is inclined both about a horizontal angle and also about a vertical angle against the optical axis of the starting projection module.
Each of the projection modules which generates a displaced segment light pattern is turned accordingly about a corresponding horizontal and vertical angle.
The lighting device according to the invention can be configured as a motor vehicle headlight, or one or more lighting devices according to the invention are arranged in a motor vehicle headlight.
The invention is discussed more closely below with the aid of the drawings. In these there are shown
The projection module 10 shown in
According to the invention, the optical axis OA2 of the second projection module 20 is inclined both about a horizontal angle φ0 and about a vertical angle γ against the optical axis OA1 of the first, so-called starting projection module 10, whereby the segment light pattern of the second projection module 20 is displaced with respect to that of the first projection module 10, as described more closely further below. The arrangement of the projection modules 10, 20 adjacent to one another is purely by way of example. In a distance of e.g. 25 metres on an aiming screen, i.e. in the far field, the practical position of the individual projection modules, therefore a local offset of the modules with respect to one another is negligible, the alignment of the optical axis OA1, OA2 is crucial.
The segment light pattern LV10 consists of several rectangular light segments SEG10, which in this example are arranged in two lines Z101, Z102 and thirteen columns S1001 . . . S1013. These numbers are selected purely by way of example to explain the invention, more or fewer columns and lines can also be used, wherein, however, preferably at least 2 lines and at least 2 columns are provided.
All light segments have the same width (extent in horizontal direction) BR, the so-called main segment width BR, for example the width can be 2.4°, preferably also 1.2°.
Furthermore, a straight line G1 can be seen, which separates the two lines Z101, Z102 from one another. The straight lint G1 preferably leads 0.57° beneath the line H-H.
The general correlation for the value of the displacement of the nth segment light pattern results at VSh(n)=m×BR+(n−1)/N×BR, n=2, . . . , N, m=0, 1, or 2, or 3, or greater than 3, is displaced in horizontal direction. The second segment light pattern (which represents the first displaced segment light pattern) carries the number n=2, the starting segment light pattern is the first light pattern.
In the example according to
N=2, (therefore n=2)
m=0
In horizontal direction, according to the invention, the second segment light pattern LV20 is displaced towards the right by a value VSh, which corresponds to half the main segment width BR, with respect to the starting segment light pattern LV10: VSh(n=2)=BR/2. In vertical direction, the second segment light pattern LV20 is likewise displaced, and namely by value VSv upwards. The vertical displacement VSv is preferably selected here in such a way that a second straight line G2, which separates the two lines Z201, Z202 from one another, is 0.23° beneath the line H-H.
At this point, it is to be noted that the straight lines G1 and G2 differ from one another only with segment light patterns which are displaced with respect to one another. With identical alignment of the projection modules 10, 20, the straight lines G1, G2 would coincide.
In the example according to
N=3, (therefore n=2, 3)
m=1
Proceeding from the starting segment light pattern LV10, accordingly the second (n=2) segment light pattern LV20 (=the first displaced segment light pattern) is displaced by 1*BR/3 horizontally towards the right, the third (n=3) segment light pattern LV30 (=the second displaced segment light pattern) is displaced by 2*BR/3 horizontally towards the right.
Optionally, as shown, provision can further be made that in addition each of the two displaced segment light patterns LV20, LV30 is displaced by a fixed amount of e.g. a main segment width BR, corresponding to the value m=1, so that the segment light patterns LV20, LV30 in this example in total are displaced by VSh (n=2)=BR+BR/2 and VSh (n=3)=BR+2*BR/3 horizontally towards the right.
With respect to the displacement VSv in vertical direction, reference is to be made to the statements concerning
As can be readily seen in the overlayings of
The light pattern for the area ahead VFL preferably adjoins the (adaptive) light pattern LV approximately beneath the straight line G1.
In the above figures, all the light segments have identical width BR. However, provision can also be made that adjoining a central region about the line V-V, in which the light segments SEG all have a first, identical width BR, adjoining to left and right further light segments SEG′, SEG″ are provided, which have a second width BR′. Typically, the second width BR′ is greater than the first width.
The first width BR defines the main segment width, and two or more identical such segment light patterns SLV as shown in
The left-hand region with the light segments SEG′ is illustrated in dotted lines, the right-hand region with the light segments SEG″ is illustrated in dashed lines. Thereby, it is to be indicated that, deviating from the above paragraphs, a first segment light pattern SLV has wider light segments SEG′ e.g. only on the left-hand side, alongside the central region of the light segments SEG. A further segment light pattern SLV, to be displaced according to the invention, has, alongside the central region, wider segments SEG″ only on the right-hand side.
In this case, the term “optically identical” is to be understood to mean that two modules, in particular projection modules, which are “optically identical”, with arrangement at identical position and with identical alignment, form identical light patterns only in the central region (as is discussed by way of example in the introduction to the description), wherein in particular also the individual light segments in the central region of the projection modules are configured in an identical manner, lie at an identical location in the light image and have the same light values (light pattern, brightness, etc.). To the left and right of the central region, “optically identical” modules can, on the other hand, generate different light segment patterns, e.g. as described above, a first and, if applicable, third, fifth, etc. module can have wider light segments only on the left of the central region, and the second and, if applicable, fourth, sixth etc. module can have wider light segments only on the right-hand side. Preferably here, a light pattern on the left of the central region (e.g. of the first segment light pattern) is mirrored about the V-V axis, in order to form the light pattern on the right of the central region (e.g. of the second segment light pattern).
Such “optically identical” light patterns can be generated either with identical projection modules, in particular identical in construction, wherein each light module certain light sources, which would generate light segments which are not used, are not operated, or the projection nodules are respectively adapted accordingly, so that for the odd-numbered segment light patterns a first type of projection modules of identical construction and for the even-numbered segment light patterns a second type of projection modules of identical construction is used.
Number | Date | Country | Kind |
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18213493.2 | Dec 2018 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2019/085400 | 12/16/2019 | WO | 00 |