Transformation optics assembly

A transformation optic arrangement for vehicles to convert a planar light distribution into an angular light distribution with a plurality of light sources arranged in one level like a matrix to generate the planar light distribution and with an optic unit arranged in front of the light sources in a primary direction of emission to deflect the light, with the optic unit comprising at least one first lens, with at least one additional lens being provided between the first lens and the light sources, arranged coaxially in reference to the z-axis extending in the primary direction of emission and distanced from the first lens, and that the first lens and at least one additional lens each show non-spherically shaped coupling surfaces and decoupling surfaces as flat sides.

CROSS REFERENCE

TECHNICAL FIELD OF THE INVENTION

The invention relates to a transformation optic arrangement for vehicles to convert a planar light distribution into an angular light distribution with a plurality of light sources arranged in one level like a matrix to generate a planar light distribution and with an optic unit arranged in front of the light sources in the primary direction of emission to deflect the light, with the optic unit comprising at least one first lens.

BACKGROUND OF THE INVENTION

In order to realize a dynamic light distribution, particularly a controllable high beam for vehicles via a matrix headlight preferably realized in LED technology, a targeted and precise impingement of the used and/or removed angular ranges is required. For example, the demand is known for a channel separation of 1°. For this purpose, a highly precise transformation optic is required, which converts the distribution of the light intensity in a reference level (planar light distribution) into an angular light distribution. This conversion must be of high quality for the entire light source matrix field so that particularly for light source matrix fields with large dimensions (for example 60 mm +/−20 mm) no solutions are known from prior art. This particularly applies if in addition to the above-mentioned high requirements for the channel separation restrictive conditions regarding structural length must be complied with.

SUMMARY OF THE INVENTION

The objective of the present invention is therefore to provide a transformation optic arrangement fulfilling the above-described requirements.

In order to attain the objective the invention is characterized in connection with the preamble of claim1such that at least one additional lens is provided between the first lens and the light sources, which is arranged coaxial in reference to the z-axis extending in the primary direction of emission of the light and distanced from the first lens, and that the first lens and at least one additional lens each show non-spherically shaped coupling areas and decoupling areas as flat sides.

The particular advantage of the invention comprises that using two lenses, each comprising non-spherically shaped coupling and decoupling areas, achieves the above-mentioned requirements with regard to channel separation (1°) for an array of light sources up to a size of 60 mm at a structural length of the transformation optic arrangement of up to 120 mm. This transformation optic arrangement here precisely converts the planar light distribution into an angular light distribution.

In particular, the first lens may comprise a front flat side (decoupling area) seen in the primary direction of emission and a rear flat side (coupling area) facing at least one other lens, with the geometry of the flat sides being determined by the non-spherical draw equivalent

z=cr21+1-(1+K)⁢c2⁢r2+∑k=15⁢α2⁢k⁢r2⁢k
to the formula. Here, z represents the z-coordinate on the respective flat side, r the lateral distance of the point on the flat side (coupling area, decoupling area) from the z-axis, c the apex curvature of the flat side, i.e. the inverse value of the radius of the lens curvature R, K the conical constant and α2k the coefficients of the 2k-th order of a polynomial development. The parameters particularly assume the following values:

Permissible deviations (tolerances) for the decoupling areas are within the following ranges:

With regard to the coupling area of the first lens the parameters preferably assume the following values:

Permissible deviations for the coupling area are discernible from the following table:

In a similar manner, depending on the above-stated formula, the non-spheric draw is also determined for the coupling area and the decoupling area of a second and only additional lens. The parameters for the decoupling area preferably result from:

Permissible deviations for the decoupling area between the second lens are defined by the following table:

The coupling area of the second lens is preferably defined by the following parameters:

Permissible deviations result as follows:

According to a further development of the invention at least 30 light sources are provided to generate the planar light distribution. The light sources are allocated in two, three, or four lines. Advantageously a plurality of different settings to reduce blinding can be achieved in the high-beam function by providing 30 light sources or more. Here, a high dynamic light function develops adjusted to the individual traffic situation. Due to the precise channel separation angular ranges with reduced blinding can be formed with sharp contours. For example, 80 or more light sources can be arranged like a matrix in three lines.

These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings.

DETAILED DESCRIPTION

A transformation optic arrangement for vehicles according toFIG. 1essentially comprises a first front lens2seen in the primary direction of light emission1and a second lens3arranged between the first lens2and the light sources, not shown. The light sources, not shown, provide a planar light distribution, which is schematically shown by the reference level4. The first lens2and the second lens3as well as the level4are aligned coaxially in reference to a z-axis5of the transformation optic arrangement extending in the primary direction of emission1.

The first lens2and the second lens3are preferably embodied rotary symmetrical in reference to the z-axis5. The level4is realized by a light source matrix arrangement, for example, which shows 30 or more light sources in preferably three lines.

The first lens2comprises a front decoupling area6in the primary direction of emission1and a coupling area7facing the second lens3. The decoupling area6and the coupling area7are embodied as flat sides of the first lens2. The second lens3comprises a coupling area8facing one of the levels4and a decoupling area9facing a first lens2. The coupling area8and the decoupling area9of the second lens3are also embodied as flat sides of the second lens3.

The decoupling area6of the first lens2is embodied curved convexly. The coupling area7of the first lens2as well as the two flat sides8,9of the second lens3are each embodied curved concavely.

The first lens2and the second lens3each show a distance10from 35 to 50 mm, preferably amounting to 43 mm. The first lens2shows a thickness11from 50 to 60 mm, preferably amounting to 56 mm, and is formed from N-BK10. The second lens3shows a thickness12from 15 to 25 mm, preferably amounting to 20 mm. It is also embodied from N-BK10. A structural length13of the transformation optic arrangement preferably amounts to 120 mm. The focal width of the transformation optic arrangement is preferably implemented for 105 mm. The lateral dimension18of the reference level4amounts to 60 mm, for example.

In order to visualize the function of the transformation optic arrangement the light path is shown for two selected points14,15of the reference level4and in order to illustrate the principle the coupling area8of the second lens3and the decoupling area6of the first lens2are shown. The first point14of the level4is located on the z-axis5of the transformation optic arrangement. The partial light beam conically emitted from the first point14is linearized by the transformation optic arrangement and emitted parallel and coaxially in reference to the primary direction of emission1.

Light emitted by the second point15is also emitted conically, with the cone being embodied symmetrical in reference to a straight19connecting the second point15and an optic center16of the transformation optic arrangement. The transformation optic arrangement renders parallel the light emitted by the second point15and sends it as a parallel partial light beam at an angle17in reference to the z-axis.

To this regard, the transformation optic arrangement provides for each arbitrary point14,15of the level4an at least visually parallel partial light beam, which is provided at a corresponding angle.

FIG. 3shows the light beam for a total of six points of the level4and the light distribution generated thereby.

The flat sides6,7of the first lens2and the flat sides8,9of the second lens3are embodied non-spherically. The geometry of the flat sides6,7,8,9is determined by the non-spherical draw, according

z=cr21+1-(1+K)⁢c2⁢r2+∑k=15⁢α2⁢k⁢r2⁢k
to the formula. Here, z represents the z-coordinate on the flat side6,7,8,9, r the lateral distance of a point on the flat side6,7,8,9, from the z-axis5, c the apex curvature of the flat side6,7,8,9, i.e. the inverted value of the radius of the lens curvature R, K the conical constant and α2kthe coefficients of the 2k-th order of a polynomial development to illustrate the non-spherical draw. The non-spherical draw formed for the exemplary embodiment according toFIGS. 1 and 3is defined by the preferred parameters in the value tables.

For selected light sources of a matrix vehicle headlight realized on an LED basis the light distribution provided is shown inFIG. 4. Here, a plurality of light sources is arranged evenly in a total of three lines. It shows that for the light sources illustrated a channel separation of 1° can be cleanly realized up to a range of approx. 12°.

FIG. 4shows the light distribution only for selected light sources. The matrix arrangement is embodied, for example, symmetrical in reference to a horizontal and vertical 0°-axis. Between the light distributions shown, additional light distributions, not shown, are realized additionally by LED not illustrated in the simulation.

LIST OF REFERENCE CHARACTERS