AT8253U1 - LENS FOR A VEHICLE HEADLAMP - Google Patents

Abstract

A lens for a headlamp for vehicles with a projection module (MOD) comprising a cup-shaped reflector (REF), a reflector (REF) associated with light source (LIQ), and the lens (LIN) and between the lens (LIN) and reflector (REF) arranged aperture (BLE), wherein the diaphragm (BLE) a light-dark boundary (HDG) of a light beam of the headlamp images, the lens (LIN) has a facing away from the reflector (REF) convex front side (VOS), an optical element (OPE) is provided on the convex front side (VOS) of the lens (LIN), and the light beams (LBU 'LBU') emerging from the optical element (OPE) are placed on a region (BDG) above the cut-off line (HDG) of the light beam (LBU) of the headlight. According to the invention, the surface (OOE) of the optical element (OPE) has elongated depressions (VE1-VE6) and / or elongated elevations (EH1-EH6) which lie laterally next to each other at least in regions, wherein the depressions (VE1-VE6) and / or elevations (EH1 - EH6) have along the surface (OOE) of the optical element (OPE) substantially from top to bottom longitudinal extent.

Description

2 AT 008 253 U1

The invention relates to a lens for a headlamp for vehicles with a projection module having a cup-shaped reflector, a reflector associated with the bulb, and the lens and an arranged between the lens and reflector aperture, wherein the aperture a light-dark boundary of a light beam of the headlamp, the lens has a 5 facing away from the reflector convex front surface, an optical element on the convex front of the lens is provided and the light rays emerging from the optical element are directed to an area above the cut-off of the light beam of the headlamp , In addition, the invention relates to a vehicle headlight with a corresponding lens.

Statutory regulations require that, for example, in the case of dipped-beam headlights or fog lamps, which have a light image with a principally clearly defined light-dark boundary, certain light values 15 are achieved in certain areas above this cut-off line.

With an aforementioned headlight - a corresponding fog light is known for example from DE-U-90 00 395 and a low beam headlight from DE 103 09 434 A1 - is through the optical element light at a certain angle through the 20 light-dark boundary distracted.

The optical element is generally a modification of the "original" lens surface, and generally, a variety of modifications are possible to deflect light into a region above the cut-off line. 25

A fundamental problem that occurs with all known lenses with such optical elements (modifications) is that the deflected beams are concentrated in a relatively small area, so that on the one hand in this area too much light passes, and on the other hand have other areas too low light levels , To remedy this negative effect, it is often provided that the lens in the region of the optical element have a matting. As a result of this matting, the light emerging from the optical element is scattered not only in the vertical direction but also horizontally so that light is radiated into a wider range beyond the cut-off line into the legally prescribed range. In this way, the legally prescribed light levels above the cut-off line can be achieved.

However, such mattings have a number of disadvantages. For example, matting reduces the transmissivity of the lens in this area, so that, correspondingly, the optical area on the lens from which light is emitted across the cut-off line must be relatively high to obtain sufficiently high levels of light. This increases the manufacturing costs, but is particularly visually disadvantageous. Furthermore, it comes in the manufacturing process with increasing number of matting produced to a wear of the tool for attaching the matting as a result of Auswaschungsprozessen in the tool, whereby the matting in the course of production weaker and correspondingly the corresponding Eigen-45 shafts of the lens are worse.

Another disadvantage of matting is that it scatters light in all directions, including vertical components, making it difficult to optimally match the lens to the desired light image. 50

It is an object of the invention to modify a lens mentioned above in such a way that an optimal adaptation of the photograph to the legal prescribed values is possible. 55 Another object of the invention is to provide the legally prescribed light values without the 3 AT 008 253 U1

Use of a matting or at least with a weaker matting than previously used to achieve.

This object is achieved with an aforementioned lens or a corresponding drive-5 zeugscheinwerfer characterized in that according to the invention the surface of the optical element at least partially laterally adjacent, elongated recesses and / or elongated elevations, wherein the depressions and / or elevations along a have the surface of the optical element substantially from top to bottom longitudinal extent. 10

By placing adjacent ribs in the area of the optical element on the convex surface of the lens, a horizontal dispersion of the light emerging from this area is achieved in addition to the vertical deflection of the light by the shape of the optical element. In this way, the light values 15 above the cut-off line can be adapted to the legal requirements, without the necessity of matting in the region of the optical element.

In fact, the optical element may be an element separate from the lens and applied to the lens in a manufacturing process. In practice, however, the convex surface of the lens is modified in a certain range in such a way, for example by a corresponding prismatic modification, that light emerging from this region now representing the "optical element" is deflected vertically beyond the cut-off line. A number of such possible modifications of the lens surface for a corresponding vertical deflection of the light are known from the prior art, and it is rather incidental to the invention how the underlying structure of the optical element is designed for vertical deflection of the light. In order to obtain a uniform horizontal spread of the light emerging from the optical element, it is favorable if adjacent depressions and / or elevations directly adjoin one another.

If one starts from the unmodified surface of the optical element as a reference surface 35, then in principle the effects of the invention can be obtained by providing only depressions in this reference surface, or by providing exclusively corresponding elevations on this reference surface.

However, it is particularly advantageous if adjacent recesses / elevations are separated from each other by an increase / depression.

Since the alternating arrangement of elevations and depressions differs less strongly from the original contour than merely elevations or depressions, this variant is the simplest in terms of design. 45

In order to prevent scattering of light in the vertical direction as a result of the elevations and depressions as well as possible, it is provided in a concrete embodiment that the depressions and / or elevations extend in planes which are normal to a horizontal plane through the lens. 50

The vertical deflection of the light is thus achieved by the "basic structure" of the optical element, and the horizontal dispersion by the elevations / depressions. This separation of the effects makes it possible to optimally design the lens for the desired photograph. 55 4 AT 008 253 U1

As a rule, a relatively homogeneous scattering of the light in the horizontal direction is desired. This is achieved in that the minima or maxima of the depressions or elevations follow each other at periodic intervals laterally. Under "homogeneous" In this context, it should be understood that the light values decrease towards the edge of the area illuminated above the bright-5 dark boundary, but so-called "hot spots", ie especially bright areas, are avoided.

The surface of the optical element is formed in the region of the depressions / elevations by a multiplicity of contours which extend laterally outward in planes lying one above the other.

It is further provided that the planes are substantially parallel to each other, and further that the planes extend through the lens substantially parallel to a horizontal plane. 15

In a simple way, a periodic structure can be achieved on the optical element if the contours have a cosine or sine curve.

With regard to lighting, even better results with regard to scattering can be achieved if the individual contours have a triangular course. However, such a structure is much more difficult to manufacture than a cosine or sine curve.

In order to produce such a triangular shape of the contours easier, it is further provided that the tips of the triangles are rounded. 25

Certain advantageous embodiments for headlights for cornering light have a lens which are pivotable about a vertical axis to the left and right. In this way, the light can be directed even when cornering in the desired direction of the vehicle. 30

However, the use of a lens described above in this context has the disadvantage that when the lens is swiveled, the width of the light spot above the cut-off line decreases with increasing tilt angle and the light intensity in this area accordingly increases. The entire ausst-35 tende light from the optical element is thus concentrated with a pivoted lens in a small area, which can lead to dazzling effects of oncoming traffic or pedestrians, and thus the legal light levels can no longer be met.

In order to eliminate this negative effect and to be able to use a corresponding lens also for a curved light spotlight, it is further provided that the individual contours have a subdued progression laterally outwards.

The contour can be linearly damped. With a linear attenuation, however, the light abruptly breaks off. Accordingly, it is provided that the attenuation has an exponential decreasing course after 45, whereby it is achieved that the light runs off homogeneously.

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

1 shows a known projection headlight, 50 FIG. 2 shows the light image in front of a vehicle generated by a headlight from FIG. 1, FIG.

3 shows a known projection headlamp with an optical element for the vertical dispersion of light,

4 shows the light image in front of a vehicle generated by a headlight from FIG. 3, FIG.

5 shows the front view of a lens according to the invention with a groove structure in the region of the optical element. FIG. 5 AT 008 253 U1

6 is a schematic representation of the lens of FIG. 5,

7 shows a detailed view of the structure of the lens from FIGS. 5 and 6 in a region of the optical element,

8 is a section along the plane A-A through the lens of FIG. 5 with a schematic 5 course of Kontor the front of the lens in this section,

9 is a detailed representation of the contour curve of FIG. 8,

FIG. 10 shows a photograph with a lens modified in accordance with FIGS. 5 to 9, FIG.

11 shows a section along the plane A-A through the lens from FIG. 5 with a schematic progression of a further contour of the front side of the lens in this section, FIG. 12 shows a detailed representation of the contour curve from FIG. 11, FIG.

13 -15 show vertical sections through the lens of FIG. 5 along the plane B-B for illustrating various arrangements of planes for constructing a contour of the lens according to the invention, FIG.

16 shows a horizontal section through a lens according to FIG. 5 according to FIGS. 8 and 11 for the purpose of illustration;

17 shows a vertical section through a lens according to the invention in the region of the optical element,

FIG. 18 shows a section through a lens from FIG. 3 along the plane A '- A' and FIG. 19 shows a section through a lens from FIG. 5 along the plane A-A and a corresponding beam path.

FIG. 1 shows the projection module MOD of a vehicle headlight, the projection module MOD consisting of a dish-shaped reflector REF, a light source LIQ associated with the reflector REF, and a lens LIN and a baffle BLE arranged between the lens LIN and the reflector REF. The light emerging from the module MOD generates a specific light image in the area in front of the vehicle, wherein the light bundle designated LBU is imaged via the diaphragm BLE as a light-dark boundary HDG, as shown in FIG. As shown, the lens LIN has a convex front side VOS facing away from the reflector REF, the back side being flat in this illustration. 30

In FIG. 2, the area illuminated essentially with a module MOD from FIG. 1 is shown hatched. As can be clearly seen, this photograph has no significant light values above the cut-off line HDG, which means that the legally prescribed light values can not be achieved. 35

FIG. 3 now shows a projection module MOD according to FIG. 1, wherein, however, the lens LIN has an optical element OPE on its convex front side VOS, which is configured in such a way that the light beams LBU emerging from the optical element OPE reach a region BDG above the light DRL-Limit HDG of light beam LBU of 40 spotlight are addressed.

As already mentioned, such modified lenses are well known and it should therefore be explained in detail at this point such an optical element. Below, however, will be discussed in more detail on a related used optical 45 element.

FIG. 4 shows the photograph obtained with a module MOD from FIG. As can be clearly seen, light is now also illuminated via the optical element OPE in a region BDG above the bright-dark boundary HDG. However, this region BDG, which is illuminated above the cut-off line, has too narrow a width, as a result of which the legal light values can again only be achieved insufficiently.

Accordingly, matting is provided in such lenses in order to also scatter the light from the optical element OPE horizontally, with the disadvantages described above. 6 AT 008 253 U1

Figure 5 now shows a lens LIN according to the invention in a front view, which instead of the e.g. can be used in Fig. 1 or Fig. 3 used lens.

In this lens LIN, the surface OOE of the optical element OPE has at least 5 laterally adjacent elongated depressions VE1-VE6 and elongated elevations EH1-EH6, the depressions VE1-VE6 and elevations EH1-EH6 being along the surface OOE of the optical element OPE directed substantially from top to bottom in length. Such a variant is structurally simpler than if the optical element OPE had only depressions or only elevations.

By attaching side by side grooves VE1 - VE6 or ribs EH1 - EH6 in the region of the optical element OPE on the convex surface VOS of the lens LIN is a horizontal dispersion of the light emerging from this area LBU, LBU 'lend-lent to the achieved by the shape of the optical element vertical deflection of the light. In this way, the light values above the cut-off line HDG can be adapted to the legal requirements, without it necessarily being necessary to achieve matting in the area of the optical element OPE. In principle, however, can also be provided to optimize the horizontal scattering effect also a matting, but this may then be less strong and thus less unwanted or uncontrollable vertical scattered light occurs, and also errors or tolerances in the production of matting then less significant.

FIG. 7 shows a detailed view of such a structure from elevations EH1-EH6 and vertices VE1-VE6. The region D shown in FIG. 7 corresponds to the region D shown in FIG. 6. FIG. 7 shows the deflection AMP of the resulting surface OOE as a function of a coordinate x. The relationship of the coordinate x with the lens surface is shown in FIG. 8, which shows a horizontal section through the lens of FIG. 5 in the region of the plane A-A. The coordinate x thus follows the lens curvature at the front side in the respective horizontal section, the coordinate x lying on the unmodified surface of the optical element OPE.

The surface OOE shown in FIG. 7 now results from the sum of superimposed contours KON, of which such a contour is shown schematically in FIG. 8 and in detail 35 in FIG. 9 (the coordinate x being "straightened" here) is.

The surface OOE of the optical element OPE shown in FIG. 7 is thus formed in the region of the depressions and elevations VE1-VE6, EH1-EH6 by a multiplicity of contours KON, which extend laterally outwards in superimposed planes ee. In the embodiment shown, the planes ee are substantially parallel to each other, as shown in FIG. 13, and the planes ee are further extended substantially parallel to a horizontal plane Eho through the lens LIN.

Likewise, the planes ee could be parallel to each other, but inclined to the plane EHO, as shown in Fig. 45, 45, or the planes ee are generally at a certain angle to each other, as shown in Fig. 15. Usually, an arrangement according to FIG. 13 is selected. In this case, starting from a lens LIN with an aspherical front side VOS, VOS 'for generating the optical element OPE the area VOS' is rotated about a horizontal, passing through the point Pkt axis, so that the resulting surface OOE results, as shown in FIG 17 is shown.

The optical element OPE can, however, also be realized as an open area, in that the corresponding modification on the front of the lens is calculated directly from the desired light image.

Another possibility for determining such an optical element is described for example in DE 103 09 434 A1. Lens having a surface as described in this document are e.g. known from the Audi A4 convertibles from the year of construction 2002.

On the basis of such an optical element OPE, depressions VE1-VE6 and elevations EH1-EH6 corresponding to FIG. 7 with contours KON, which run in planes ee in accordance with FIG. 11, are then applied. 10

In this procedure, it can be easily differentiated between the vertical dispersion of the light by the optical element OPE per se and the horizontal dispersion, resulting in a comparatively simple calculation of the surface OOE. Using pits and ridges resulting from contours lying in planes ee as shown in Fig. 14 or Fig. 15, it is not absolutely necessary to first calculate the vertical spread and to modify the lens accordingly, but the lens surface can be similarly designed to yield an optical element OPE for vertical scattering with a corresponding additional horizontal scattering structure.

It can be seen from FIG. 9 and further from FIG. 16 that the depressions VE1-VE6 and elevations EH1-EH6 run in planes ev which are normal to a horizontal plane Eho through the lens LIN. The mutually associated superimposed maxima MA1 - MA6 of the 25 individual elevations EH1 - EH6 and the mutually associated superimposed minima MI1 - MI6 of the contours KON are thus in common vertical planes ev, which run parallel to the plane Eve. This can be seen particularly well from the horizontal section of FIG. 16 through the lens LIN, but the planes ev are also indicated in FIGS. 7 and 9. In this way, with the structure of ridges and depressions mainly a horizontal deflection is achieved, whereby an optimal and easy adaptation of the lens surface OOE to the desired light image can be achieved.

The vertical deflection of the light is thus achieved by the "basic structure" of the optical element OPE, and the horizontal dispersion by the elevations and depressions. Through this separation of the effects, an optimal design of the lens LIN on the desired photograph is possible.

As a rule, a relatively homogeneous scattering of the light in the horizontal direction is desired. This is achieved by the minima MI1-MI6 and maxima MA1-MA6 of the 40 wells VE1-VE6 and elevations EH1-EH6, respectively, following one another at periodic intervals PEL. By "homogeneous" in this context is to be understood that the light values to the edge of the illuminated above the light-dark boundary area BDG decreases, but that so-called "hot spots", ie particularly bright areas are avoided. In a simple way, a periodic structure can be achieved on the optical element if the contours KON have a cosine or sine curve. In the illustrated surface OOE, a cosine shape was chosen because it shows a symmetrical behavior when the projections and depressions extend on both sides of the longitudinal center plane Eve of the lens LIN, as shown in FIG. 50

The adaptation of the horizontal spread is done by adjusting the values for the period length PEL and the amplitude AMP of the contours KON. The intensity horizontal of scattering of the light depends on the slope of the course of the contour KON. The smaller the period length PEL, the stronger the scattering. Likewise, the larger the amplification AMP is, the greater the spread. δ ΑΤ 008 253 U1

An exemplary value for a period length is PEL = 3.5 mm.

FIGS. 18 and 19 show the effects of the elevations and depressions on the light passing through the lens LIN in this region in each case in a horizontal section through the lens. The lens LIN of Fig. 18 has no structure according to the invention, the light rays of the light beam LBU 'passing through the lens in this section do not undergo horizontal deflection.

As a result of the described surface structure according to the invention, as in FIG. 19, in addition to the unrecognizable vertical deflection, there is additionally a horizontal deflection of the beams of the light bundle LBU '. This leads to a light image as shown in Fig. 10. Due to the structure of elevations and depressions, the area above the light-dark boundary HDG, into which light is scattered from the optical element OPE, is broadened, as a result of which the legal light values can be achieved. 15

A cosine progression as shown can be relatively easily applied to the lens surface. Lighting technically even better is a jagged course as shown in Figures 11 and 12. However, such is much more expensive to produce. A compromise can be achieved if the tips in the course of FIGS. 11 and 12 are rounded; such a structure is somewhat simpler to produce and provides approximately the same technical advantages as non-rounded tips.

In principle, the elevations and depressions can all have approximately the same amplitude AMP 25 in the maximum / minimum. Certain embodiments of headlights for cornering lights (see, for example, EP 1 234 716 A2) now have a lens which can be pivoted to the left and right about a vertical axis VAC. Such an axis VAC is shown in FIG. 1 and FIG. 3, respectively. 30 In this way, the light can be directed in cornering in the desired direction of the vehicle.

The use of a lens LIN with elevations and depressions having the same maximum amplitude AMP, however, has the disadvantage in this context that, with a pivoting of the lens, the width of the light spot above the cut-off line decreases with increasing tilt angle and the light intensity in this area increases accordingly. The entire light emerging from the optical element OPE light is thus concentrated in the swivel lens in a small area, which can lead to dazzling effects of oncoming traffic or pedestrians, and thus the legal Lichtwer-40 te can not be met.

In order to eliminate this negative effect and to be able to use a corresponding lens LIN for a bend headlight, it is further provided that the individual contours KON have laterally outward a damped course. 45

This is shown correspondingly in FIGS. 7 to 9 as well as FIGS. 11, 12 and 19. The contour KON can be linearly damped.

However, it is desired that the light distribution in the region BDG has a homogeneous profile above the bright-50 dark boundary HDG. In this context, however, "homogeneous" does not mean that the light values are the same everywhere in the area BDG - rather, they decrease towards the edge of the area - but that the light values change as evenly as possible, so that the light image has no "blotchiness", So there are no abrupt changes between light and dark. 55

Claims (11)

9 AT 008 253 U1 With e.g. However, in the case of a pivoting of the lens, this condition can not be fulfilled optimally or not at all by a linear damping. Accordingly, it is provided that the damping has an exponentially decreasing outward course, whereby the light is achieved in a homogeneous manner. The light intensity has a constant gradient in the area BDG, i. the light intensity is constantly less, resulting in a homogeneous expiring impression of the light intensity. In the case of an abrupt termination, a light-dark border would be seen as in the case of a low beam headlight, which, however, is generally undesirable. The exponential course can be found to be ideal for the problem described above. As a formula, the course of the amplitude AMP as a function of the coordinate x for a contour KON can be represented as follows: 15 AMP (x) = AMP0 * Cos (2π * x / PEL) * exp (-x / dl) with the attenuation length dl , Which is selected such that the light image in all pivot positions has a homogeneous as possible, uniformly decreasing profile of the light intensity as described above in all pivotal positions. The contour KON in FIG. 9 has the typical values of AMP0 = 0.35 mm, PEL = 3.5 mm and dl = 6 mm. Correspondingly, the contour KON shown in FIGS. 11 and 12 also has an exponential profile decreasing toward the outside. Claims 1. A vehicle headlamp lens comprising a projection module (MOD) comprising a dish-shaped reflector (REF), a reflector (REF) illuminant (LIQ), and the lens (LIN) and an intermediate lens (LIN ) and reflector (REF) arranged aperture (BLE), wherein the diaphragm (BLE) a light-dark boundary (HDG) of a light beam of the headlamp images, the lens (LIN) facing away from the reflector (REF) 35 convex front ( VOS), an optical element (OPE) is provided on the convex front side (VOS) of the lens (LIN), and the light beams (LBU 'LBU') emerging from the optical element (OPE) are directed to a region (BDG) above the light Dark boundary (HDG) of the light beam (LBU) of the headlamp are directed, wherein the surface (OOE) of the optical element (OPE) at least partially 40 laterally adjacent, elongated recesses (VE1 - VE6) and / or elongated heights ( EH1 - EH6) wherein the depressions (VE1 - VE6) and / or elevations (EH1 - EH6) have a longitudinal extent directed essentially along the surface (OOE) of the optical element (OPE) from top to bottom, and wherein the surface (OOE) of the optical element (OPE) in the region of the depressions / elevations (VE1-VE6, EH1-EH6) is formed by a multiplicity of contours (KON), which run laterally outwards in superimposed planes (ee), characterized that the individual contours (KON) have laterally outward a damped course. 50 2. Headlight according to claim 1, characterized in that adjacent recesses (VE1 - VE6) and / or elevations (EH1 - EH6) directly adjoin one another. 3. Headlamp according to claim 1 or 2, characterized in that adjacent depressions / elevations (VE1-VE6, EH1-EH6) in each case by an increase / depression 10 AT 008 253 U1 (VE1-VE6, EH1-EH6) from each other are separated. 4. Headlight according to one of claims 1 to 3, characterized in that the recesses (VE1 - VE6) and / or elevations (EH1 - EH6) in planes (ev) extend which 5 normal to a horizontal plane (Eho) through the lens (LIN) stand. 5. Headlight according to one of claims 1 to 4, characterized in that the minima (MI1 - MI6) and maxima (MA1 - MA6) of the recesses (VE1 - VE6) and elevations (EH1 - EH6) at periodic intervals (PEL ) follow each other laterally. 10 6. Headlight according to one of claims 1 to 5, characterized in that the damping has an exponentially decreasing towards the outside course. 7. Headlight according to one of claims 1 to 6, characterized in that the Ebe 15 NEN (ee) are substantially parallel to each other. 8. Headlight according to claim 7, characterized in that the planes extend substantially parallel to a horizontal plane (Eho) through the lens (LIN). 9. Headlight according to one of claims 1 to 8, characterized in that the Kontu Ren (KON) have a cosine or sine wave. 10. Headlight according to one of claims 1 to 8, characterized in that the individual contours (KON) have a triangular course. 25 11. Headlight according to claim 10, characterized in that the tips of the triangles are rounded. 30 of which 8 sheets drawings 35 40 45 50 55