DE102008049168A1 - Projection body for headlight of motor vehicle, has primary part formed as three-axis ellipsoid body, where projection body is geometrically designed so that light exhibits collimation in collimation plane and scattering in scattering plane - Google Patents

Abstract

The body has light sources (1a, 1b) illuminating a primary part (2) of the body for light formation. The light is guided by internal total reflection in a direction of a secondary part (3) over the light sources, and uncoupled from the body over the secondary part. The primary part is formed as a three-axis ellipsoid body for light formation in the direction of the secondary part. The projection body is geometrically designed such that the light exhibits a collimation in a collimation plane (y) and a scattering in a scattering plane.

Description

The The present invention is directed to a projection body for generating a light field, in particular for a Headlight of a motor vehicle. The projection body is designed with at least one light source for Light shaping a primary part of the projection body illuminates and transmits the light through internal total reflection in the direction of a secondary part of the projection body is conductive, exercise the light from the projection body can be decoupled.

A generic-forming projection body is from the WO 2005/026790 A1 already known. The projection body is used to generate a light field, as this is emitted in a known manner by the headlight of a motor vehicle in the direction of travel. The projection body is made in one piece and has a primary part, which is illuminated by the light source and to which a secondary part adjoins to receive the light reflected in the primary part and to generate a light shaping, which leads to the formation of the light field. The light is coupled out via a decoupling surface of the secondary part, wherein the generated light field does not have a satisfactory distribution, as is required for use in traffic.

It is therefore the object of the present invention, a projection body to create, which is simple and the sending of a improved light field allows.

These Task is based on a projection body according to the The preamble of claim 1 in conjunction with the characterizing features solved. Advantageous developments of the invention are specified in the dependent claims.

The The invention includes the technical teaching that the primary part is designed as a triaxial ellipsoidal body and a Light shaping in the direction of the secondary part allows wherein the projection body is formed geometrically is that the light in at least one collimation plane is a collimation and in at least one scattering plane has a scattering.

The Invention is based on the idea of a projection body to create a form of light that forms a light field, a collimation and a scattering of the light allows, where the projection body has a compact design and can be coupled directly to the light source. The field of light, which is generated by a headlight of a motor vehicle, is present in a collimation plane and in a perpendicular to Subdivided collimation plane extending scattering plane. The collimation plane runs thereby in the vertical, whereby the light distribution within the light field at least when emitting a low beam has a cut-off line, and where the area below this border is lit and the area above the border has no or only a very small proportion of light. Under a collimation becomes a parallel alignment of light rays understood, the present form the cut-off line. That emitted Light field points in the collimation plane near the cut-off line a high intensity and owns towards the roadway of the motor vehicle a decreasing intensity.

On the other hand the spreading plane forms the transverse direction to the motor vehicle. In the Spreading plane no direct collimation of the light radiation is required because an outflow of intensity in the scattering plane is required is lit, and a significantly larger angle range becomes as it does in the collimation plane. According to the invention the projection body is therefore geometrically designed in such a way that that in the triaxial ellipsoidal body, a preforming of Light is made possible and by the subsequent secondary part the collimation and the scattering generated or supported becomes.

One particular advantage is formed by the fact that the projection body is made in one piece and of uniform material and that the light source is introduced within the ellipsoidal body is. The primary part thus passes in one piece into the secondary part, wherein the primary part forming ellipsoidal body towards the abutment not complete and finally executed, but without complete ellipsoid contour merges into the abutment. The light source is incorporated within the ellipsoidal body, so that it emits light into the ellipsoidal body. The light shaping is based on total internal reflection at the ellipsoidal body delimiting surfaces, these at least partially may also have a reflective coating, to an unwanted leakage of light from the projection body to avoid, for example, when the critical angle of total reflection is fallen short of.

It is furthermore advantageous that the ellipsoidal body has a first focal plane, wherein the light source spatially coincides within the ellipsoidal body with the first focal plane. Furthermore, the ellipsoidal body has a second focal plane arranged in the direction of the secondary part, in which the light after internal total reflection on the wall of the ellipsoidal body has a preforming in order to enter the secondary part. The preforming of the light in the second focal plane of the ellipsoidal body depends on the shape of the ellipse, the refractive index of the material of the projectile Onskörpers also has an influence on the preforming of the light, which can be indicated analytically using the Fermat principle.

In The focal plane may be provided a diaphragm device, wherein the light emitted from the projection body becomes a has a substantially horizontally extending cut-off line, the divisible by means of the aperture device or in the geometry the light intensity distribution can be influenced. The aperture device can be in the form of a static aperture in the projection body can be used, wherein the aperture formed geometrically is that the proportion of light rays that is above the cut-off line emitted, is hidden by the aperture. Illuminates, for example, the Light source only the upper half-space of Ellipsoidkörpers out, so the light emitted into the upper half space at the Wall reflects and enters the secondary part of the projection body a, wherein only the lower portion of the secondary part illuminated will, resulting in the emission of light below the cut-off line leads. The use of an aperture becomes the cut-off point aufgesteilt or sharpened, with a small residual share of Light may also be desired above the cut-off line can, by occurring scattering in the vertical direction of collimation can be formed.

The light provided by the light source is transmitted through a Decoupling surface coupled out of the projection body, the the termination surface of the abutment in the direction forms the optical axis. The decoupling surface can be a Own focal plane that within the projection body lies and spatially with the second focal plane of the ellipsoidal body coincides. The light distribution in the second focal plane of the ellipsoidal body is therefore characterized by the following Secondary part taken and through the refractive interface collimated in a plane passing through the decoupling surface is formed. The decoupling surface can be from a part of a Be derived elliptical shape, wherein the decoupling surface may have other aspheric forms.

advantageously, the three-axis ellipsoidal body has a first half-axis and one opposite the spatial extent the first half-axis rotated by 90 ° second semi-axis larger spatial Extension. The third half-axis of the ellipsoidal body becomes through the optical axis of the projection body itself educated. The smaller, first half-axis may extend parallel to the collimation plane, so that the second half-axis extends parallel to the scattering plane.

The Setting the desired spread of light distribution may extend differently with an ellipsoidal body Semi-axles are made by that from the direction of the area the first half-axis reflected light in the second focal plane which is from the direction of the region of the second half-axis reflected light lies behind the second diaphragm plane. The way resulting, preformed light distribution is now through the secondary part mapped to infinity, wherein the decoupling surface is rotationally symmetric formed around the optical axis.

alternative a desired scattering effect can be achieved or be strengthened that the secondary part with the Decoupling surface in the manner of an elliptical cylinder part is formed, which extends in the vertical direction and through two parallel axes or opposite the optical axis Employed side surfaces is limited by the scattering effect is adjustable in scatter direction. The elliptical cylinder part becomes by an ellipsoidal or ellipsoidal, refractive surface by parallel displacement along the Vertical continued. The resulting elliptical cylinder can be employed by the axis-parallel or against an optical axis Level are cropped. So lies in cuts parallel to the emission level an ellipsoidal shape of the interface that breaking acts. By contrast, with the parallel side surfaces leaves due to occurring total reflection of the scatter angle set specifically.

Farther it is advantageous that in the area of the first focal plane of the ellipsoidal body two light sources are introduced, wherein a first light source an upper and a second light source a lower half-space the ellipsoidal body illuminates or wherein the light sources along the optical axis are arranged offset from each other and radiate into the same half-space. To realize a bifunction, d. H. the high beam function and the dipped beam function to introduce additional light sources in the region of the first focal plane. The subdivision of the upper and lower half space takes place in the direction to the collimation axis, and thus towards the spatial axis Extension of the first half axis.

The at least one light source can be designed as a light-emitting diode, wherein the light source is accommodated in a receiving space within the projection body. Newer light sources for headlights of motor vehicles are formed by high-performance light-emitting diodes, wherein the emission body of the light-emitting diode can be optically coupled to the projection body by means of a fluid adapted in the refractive index. If two light-emitting diodes are provided for introduction into the projection body, they can be coupled into the projection body in pairs by the index-adapted fluid. This arises from the emission of light from the emissive body of the light emitting diode to the emission of light from the projection body, a minimal loss of luminosity, wherein further mechanical stresses are avoided, which can form between the emission body of the light emitting diode and the projection body. For cooling the light-emitting body, a heat sink may be introduced into the receiving space, to which the light-emitting diodes is coupled. The heat sink can in particular act as an active heat sink by flowing through it with a coolant.

Of the Recording space extends from the direction of the optical axis back into the projection body, so that this one kind Channel forms, through the further the electrical supply of the light sources can run. The length of the projection body in the direction of the optical axis can be a value of 30 mm to 80 mm, preferably a value of 40 mm to 70 mm, and particularly preferably one Value of 60 mm, with the projection body off a polycarbonate or a polymethylmethacrylate formed can be.

Further, The measures improving the invention will be described below together with the description of a preferred embodiment of the invention with reference to the figures shown in more detail. It shows:

1 an embodiment of the projection body in a first section, wherein the sectional plane is formed by the optical axis and the Kollimationsebene and

2 a further view of the projection body in a second section, wherein the cutting plane is formed by the optical axis and the scattering plane.

In the 1 and 2 is a schematic view of an embodiment of a projection body for generating a light field according to the present invention shown in 90 ° to each other rotated sectional planes. The projection body can be integrated in the headlight of a motor vehicle, and extends along an optical axis 7 , The optical axis 7 and consequently the projection body can be integrated with the horizontal in a slightly forwardly inclined position in the headlight. The emitted light field has a collimation plane y, z, which extends in the vertical direction and is characterized by a light-dark boundary, for example along the optical axis shown 7 can run. The beam path shown runs below the cut-off line, so that a dipped beam is emitted from the projection body. Further shows 2 a scattering plane x, z, which runs transversely to the motor vehicle.

In the projection body, two light sources are introduced, wherein a first light source 1a opposite a second light source 1b is arranged. The beam path shown is from the first light source 1a emitted. The projection body is made in one piece and of uniform material and is in a primary part 2 and in a secondary part 3 divided, which merge into each other. The primary part 2 is a triaxial ellipsoidal body 2 formed, wherein the secondary part 3 has a funnel-like shape, and in the direction of the optical axis 7 through a decoupling surface 6 is limited. The secondary part 3 is through side surfaces 8th limited, which give this a funnel shape, which extends in scattering plane x, z, which describes the transverse direction of the motor vehicle or the headlamp, in which the projection body is received.

In 1 is recognizable that the first light source 1a in the upper half-space and the second light source 1b into the lower half-space of the ellipsoidal body 2 emitted. The beam path shown is from the first light source 1a generated and reflected on the wall of the upper half-space within the Ellipsoidkörpers 2 , This has a focal point spatially with the arrangement of the light sources 1a and 1b coincides. Furthermore, the ellipsoidal body has 2 a focal plane 4 on, in which the light after total internal reflection on the wall of the upper half-space of the ellipsoidal body 2 has a preform to enter the abutment 3 enter. Furthermore, a diaphragm device 5 shown in the focal plane 4 is arranged, wherein the aperture device 5 extends into the projection body only at a limited height. The height is limited such that the part of the light rays through the aperture device 5 can be hidden, the above the cut-off line on the decoupling surface 6 can escape from the projection body. Consequently, the aperture device shown serves 5 for the division of the light-dark boundary or for influencing the light intensity distribution of the generated light field.

The ellipsoid body 2 is a triaxial ellipsoidal body 2 executed, so that the first half-axis a has a smaller spatial extent than the second half-axis b. The first semiaxis a runs in the collimation plane y, z, the second semiaxis b extending in the scattering plane x, z. The focal plane shown 4 corresponds to the focal plane of the light, which is reflected by the upper and lower half space, as in 1 is shown. Consequently, the light coming from the direction of the region of the first half-axis becomes the focal plane 4 sharply depicted. By contrast, the light reflected from the region of the second, larger semiaxis b becomes light in the second focal plane 4 not sharp imaged, so that a scattering effect in scattering direction x is achieved. The light reflected from the region of the direction of the second semiaxis b enters the secondary body 3 one and can be at the opposite the optical axis 7 employed side surfaces 8th reflect. As a result, the desired scattering effect is formed or amplified, and there is the required light field with a substantially horizontal light-dark boundary and a scattering in the side region of the headlamp or the motor vehicle.

Will a switchable aperture device 5 provided, a Bifunktion of the projection body can be achieved to emit both a dipped beam and a high beam. Will the aperture device 5 not provided within the projection body, by the operation of both the first light source 1a as well as the second light source 1b an additional high beam function can be met. Furthermore, a radially emitting light source may be provided, so that a high beam function. can also be met with a single light source.

The Invention is limited in its execution not to the preferred embodiment given above. Rather, a number of variants is conceivable, which of the illustrated solution even with fundamentally different types Use. All from the claims, the description or drawings resulting features and / or Advantages, including design details, spatial arrangements and process steps, both for themselves as well as in a variety of combinations essential to the invention be.

1

light source

2

Primary part / ellipsoid

3

secondary part

4

focal plane

5

aperture means

6

outcoupling

7

optical axis

8th

side surface

9

accommodation space

x

vertical direction

y

Horizontal direction

y, z

Kollimationsebene

x, z

scattering plane

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• WO 2005/026790 A1 [0002]

Claims (15)

Projection body for generating a light field, in particular for a headlight of a motor vehicle, with at least one light source ( 1a . 1b ), which for forming a primary part ( 2 ) of the projection body and via which the light is transmitted by total internal reflection in the direction of a secondary part ( 3 ) of the projection body can be guided, via which the light can be coupled out of the projection body, characterized in that the primary part ( 2 ) as a three-axis ellipsoidal body ( 2 ) is formed and a light shaping in the direction of the secondary part ( 3 ), wherein the projection body is formed geometrically such that the light has collimation in at least one collimation plane (y, z) and scattering in at least one scattering plane (x, z). Projection body according to claim 1, characterized in that the projection body is made in one piece and of uniform material and the light source ( 1a . 1b ) within the ellipsoidal body ( 2 ) is arranged. Projection body according to claim 1 or 2, characterized in that the ellipsoidal body ( 2 ) has a first focal plane, the light source ( 1a . 1b ) within the ellipsoidal body ( 2 ) spatially coincides with the first focal plane. Projection body according to one of claims 1 to 3, characterized in that the ellipsoidal body ( 2 ) a second focal plane ( 4 ), in which the light after total internal reflection on the wall of the ellipsoidal body ( 2 ) undergoes a preforming in order to move into the secondary part ( 3 ) to enter. Projection body according to one of the preceding claims, characterized in that a diaphragm device ( 5 ) provided in the second focal plane ( 4 ), wherein the light emitted from the projection body has a substantially horizontally extending cut-off line which, by means of the diaphragm device ( 5 ) can be divided or influenced in the geometry of the light intensity distribution. Projection body according to one of the preceding claims, characterized in that the secondary part ( 3 ) a decoupling surface ( 6 ), which comprises a focal plane lying in the projection body, which with the second focal plane ( 4 ) of the ellipsoidal body ( 2 ) coincides spatially. Projection body according to one of the preceding claims, characterized in that the three-axis ellipsoidal body ( 2 ) has a first half-axis (a) and a relative to the spatial extent of the first half-axis (a) by 90 ° rotated second half-axis (b) of greater spatial extent. Projection body according to one of the preceding claims, characterized in that the projection body about an optical axis ( 7 ), wherein the decoupling surface ( 6 ) one around the optical axis ( 7 Having formed around it rotationally symmetrical elliptical part shape. Projection body according to claim 8, characterized in that the partial beams of the light, which from the region of the first half-axis (a) of the ellipsoidal body ( 2 ), in the focal plane ( 4 ) are shown and through the decoupling surface ( 6 ) are collimated in the collimation plane (y, z). Projection body according to claim 8 or 9, characterized in that the partial beams of the light, which from the region of the second half-axis (b) of the Ellipsoidkörpers ( 2 ), in the focal plane ( 4 ) are not sharply imaged and through the decoupling surface ( 6 ) are scattered in the scattering plane (x, z). Projection body according to one of claims 1 to 7, characterized in that the decoupling surface ( 6 ) is formed in the manner of an elliptical cylinder part, which extends in the vertical direction (x) and by two axis-parallel or with respect to the optical axis ( 7 ) employed side surfaces ( 8th ) is limited, by which the scattering effect in the scattering plane (x, z) is adjustable. Projection body according to one of claims 3 to 11, characterized in that in the focal point of the ellipsoidal body ( 2 ) two light sources ( 1a . 1b ), wherein a first light source ( 1a ) an upper and a second light source ( 1b ) a lower half-space of the ellipsoidal body ( 2 ) illuminates. Projection body according to one of the preceding claims, characterized in that the at least one light source ( 1a . 1b ) is designed as a light-emitting diode, wherein the light source ( 1a . 1b ) in a recording room ( 9 ) is recorded. Projection body according to claim 13, characterized characterized in that the at least one light-emitting diode by means of a refractive index matched fluid to the projection body optically coupled. Projection body according to one of the preceding claims, characterized in that the length of the projection body in the direction of the optical axis ( 7 ) has a value of 30 mm to 80 mm, preferably a value of 40 mm to 70 mm and be particularly preferably has a value of 60 mm, and wherein the projection body is formed of polycarbonate or polymethylmethacrylate.