Headlight for a vehicle

Abstract

A headlamp (1) for a vehicle, comprising at least one light source (2), a primary optical system (3) for generating a lighting image, and an optical imaging system (4), wherein the lighting image can be projected onto the roadway as a light image by means of the optical imaging system (4), and the primary optical system (3) has a plurality of light guiding elements (5) and a support layer (6), wherein the light guiding elements (5) are arranged on a rear face (6r) of the support layer (6), and the lighting image can be generated on a front face (6v) of the support layer (6), the light guiding elements (5) are arranged adjacently to one another or in an overlapping manner in a row in an axis direction (y) and form at least one line (7), wherein each light guiding element (5) has a light inlet surface (5e) for coupling in light from at least one light source (2) and a light outlet surface (5a) for coupling out light, wherein the totality of the light guiding elements (5) of the at least one line (7) have a common border (8) which is constantly curved on at least one face oriented substantially along the axis direction (y) and together with the support layer (6) forms a section curve with a curved curve course (9, 10).

Claims

1. A headlamp (1) for a vehicle, comprising: at least one light source (2); a primary optical system (3) for generating a lighting image; and an optical imaging system (4) configured to project the lighting image onto a roadway as a light image, wherein the primary optical system (3) has a plurality of light guiding elements (5) and a support layer (6), wherein the light guiding elements (5) are arranged on a rear face (6r) of the support layer (6), and the lighting image can be generated on a front face (6v) of the support layer (6), wherein the light guiding elements (5) are arranged adjacently to one another or in an overlapping manner in a row in an axis direction (y) and form at least one line (7), wherein each light guiding element (5) has a light inlet surface (5e) for coupling in light from at least one light source (2) and a light outlet surface (5a) for coupling out light, and wherein the totality of the light guiding elements (5) of the at least one line (7) have a common border (8) which is constantly curved on at least one face oriented substantially along the axis direction (y) and together with the support layer (6) forms a section curve with a curved curve course (9, 10).

2. The headlamp (1) according to claim 1, wherein the headlamp (1) comprises a plurality of parallel lines (7, 7a, 7b).

3. The headlamp (1) according to claim 2, wherein the lines (7, 7a, 7b) are arranged horizontally or vertically oriented in an installed position in the vehicle.

4. The headlamp (1) according to claim 2, wherein all lines (7, 7a, 7b) form a common border (8a), which is constantly curved on at least one face oriented in the axis direction (y) and together with the support layer (6) forms a section curve with a curved curve course (9, 10).

5. The headlamp (1) according to claim 1, wherein the curve course (9, 10) follows a cosine function.

6. The headlamp (1) according to claim 1, wherein the curve course (9, 10) is a segment of a circle.

7. The headlamp (1) according to claim 1, wherein the curve course (9, 10) is a segment of an ellipse.

8. The headlamp (1) according to claim 1, wherein the curve course (9, 10) is a freely shaped line.

9. The headlamp (1) according to claim 1, wherein the curve course (9, 10) is a freely shaped line corresponding to a segment of a circle with increasing curvature.

10. The headlamp (1) according to claim 1, wherein the border (8, 8a) forms a curve course (9, 10) on each of two faces and both curved curve courses (9, 10), considered jointly, form a convex shape.

11. The headlamp (1) according to claim 1, wherein at least one light source (2) is assigned to each light guiding element (5) or the associated light inlet surface (5e).

Description

(1) The invention and advantages thereof will be described in greater detail hereinafter with reference to non-limiting examples, which are illustrated in the accompanying drawings, in which

(2) FIG. 1: shows a perspective exploded view of a vehicle headlamp according to the prior art,

(3) FIG. 2: shows a view of a primary optical system from below according to the prior art,

(4) FIG. 3: shows a view of a primary optical system from behind according to the prior art,

(5) FIG. 4: shows a view of the primary optical system of FIG. 3 from above,

(6) FIG. 5: shows a perspective view of the primary optical system of FIGS. 3 and 4,

(7) FIG. 6: shows an illustration of the light image of a headlamp according to the prior art,

(8) FIG. 7: shows a perspective exploded view of the vehicle headlamp according to the invention,

(9) FIG. 8: shows a view of the primary optical system according to the invention from behind,

(10) FIG. 9: shows a view of the primary optical system of FIG. 8 from above, and

(11) FIG. 10: shows an illustration of a light image that can be attained with a headlamp according to the invention.

(12) With reference to FIG. 1 an exemplary embodiment of the invention will now be explained in greater detail. In particular, the parts important for a headlamp according to the invention are illustrated, wherein it is clear that a headlamp also contains many other parts which enable an expedient use in a motor vehicle, such as a passenger car or motorbike in particular.

(13) In FIG. 1 a headlamp 101 according to the prior art for a vehicle comprising at least one light source 102, a primary optical system 103 for generating a lighting image, and an optical imaging system 104 is illustrated by way of example, wherein the lighting image can be projected in the form of a light image onto the roadway by means of the optical imaging system 104, wherein the projection is performed in the direction of the optical axis z onto the roadway and the lines are arranged horizontally or vertically oriented in the installed position in the vehicle.

(14) The primary optical system 102 according to the prior art in FIG. 2 to FIG. 5 has a plurality of light guiding elements 105, wherein each light guiding element 105 has a light inlet surface 105e for coupling in light from at least one light source 102, which light is emitted for example from an LED, and each light guiding element 105 has a light outlet surface 105a for coupling out light.

(15) The primary optical system 102 comprises a plurality of light guiding elements 105, which are arranged adjacently to one another or in an overlapping manner in a row in an axis direction x and form a line 107, wherein the primary optical system 103 has a plurality of light guiding elements 105 and a support layer 106, wherein the light guiding elements 105 are arranged on a rear face 106r of the support layer 106 and the primary optical system 103 comprises three parallel lines 107, 107a and 107b arranged vertically one above the other, and this arrangement forms three horizontally adjacent regions 103a, 103b and 103c.

(16) The light outlet surfaces 105a of horizontally adjacent light guiding elements 105, starting from the centrally arranged region 103b, have an increasing size of the outlet surfaces 104a towards the two ends 103a and 103c.

(17) The light outlet surfaces 105a are usually larger than the corresponding light inlet surfaces 105e of the corresponding light guiding element 105.

(18) The lighting image can be produced on the front side 106v of the support layer 106, in which the Petzval plane of the optical imaging system 103 is arranged and projects the generated overall lighting image as light image in front of the vehicle.

(19) In principle, the shapes of the light inlet surfaces 105e and light outlet surfaces 105a of the light guide elements 105 are freely selectable, but are usually round or rectangular or square. The particular shape is dependent on the desired applicationfor example as main beami.e. the radiation characteristics of the light from the individual light guiding element. The longitudinal shape of the light guiding element 105 also has a number of degrees of freedom in respect of its shaping, wherein a straightfunnel-shapedor also a curved course is often used.

(20) FIG. 6 shows the light image generated by the headlamp according to the prior art, in which distortions 111a and 111ba cushion-like distortion or what is known as a wingcan be seen in the top left and top right corners respectively. The lower edge 112 of the light image also has vertical curvatures 112a and 112b (likewise a cushion-like distortion) running from the central region 103b towards the edges 103a and 103c respectively, which can be seen in the projected light image in front of the vehicle and forms an interfering effect.

(21) FIG. 7 shows an example of a headlamp 1 according to the invention for a vehicle comprising at least one light source 2, a primary optical system 3 for generating a lighting image, and an optical imaging system 4, wherein the lighting image can be projected in the form of a light image onto the roadway by means of the optical imaging system 4, and the lines are arranged horizontally or vertically oriented in the installed position in the vehicle.

(22) The primary optical system 2 according to the invention in FIG. 8 and FIG. 9 has a plurality of light guiding elements 5, wherein each light guiding element 5 has a light inlet surface 5e for coupling in light from at least one light source 2, which for example is emitted from an LED, and each light guiding element 5 has a light outlet surface 5a for coupling out light.

(23) The primary optical system 2 comprises a plurality of light guiding elements 5 which are arranged adjacently to one another or in an overlapping manner in a row in an axis direction y and form a line 7, wherein the primary optical system 3 has a plurality of light guiding elements 5 and a support layer 6, wherein the light guiding elements 5 are arranged on a rear face 6r of the support layer 6 and the primary optical system 3 comprises three parallel lines 7, 7a and 7b arranged vertically one above the other, and this arrangement forms three horizontally adjacent regions 3a, 3b and 3c.

(24) The lighting image can be produced on the front side 6v of the support layer 6, in which the Petzval plane of the optical imaging system 3 is arranged and projects the generated overall lighting image as light image in front of the vehicle.

(25) The totality of light guiding elements 5 of the lines 7, 7a and 7b additionally have a common border 8a, which is constantly curved on at least one face oriented substantially along the axis direction y and together with the support layer 6 forms a section curve with a curved curve course 9 or 10.

(26) The curvature of the curves 9 and 10 preferably follows a cosine depending on the optical imaging system used, but can also be formed as a segment of a circle or segment of an ellipse in order to facilitate the construction. More complex curve courses for reducing the distortion are not shown here, but are also conceivable if the optical imaging system generates distortions of higher order. The severity of the curvature can be dependent on the vertical distance h.sub.7 or h.sub.7b of the horizontal row from the horizontal axis.

(27) The improved light image with the practically straight lines 11 and 12 is shown in FIG. 10. The corners 11a, 12a, 11b and 12b, compared to the light image according to the prior art in FIG. 6, lie much further within the desired limits, with no manifestation of the wings.

LIST OF REFERENCE SIGNS

(28) 1, 101 headlamp 2, 102 light source 3, 103 primary optical system 3a, 103a end region of the primary optical system, front right view 3b, 103b middle region of the primary optical system 3c, 103c end region of the primary optical system, front left view 4, 104 optical imaging system 5, 105 light guiding element 5a, 105a light outlet surface of a light guiding element 5e, 105e light inlet surface of a light guiding element 6, 106 support layer 6r, 106r rear face of the support layer 6v, 106v front face of the support layer 7, 107 upper row of the light guiding elements 7a, 107a middle row of the light guiding elements 7b, 107b lower row of the light guiding elements 8 common border of a line 8a common border of all lines 9, 109 line through contour of the upper delimitation 10, 110 line through contour of the lower delimitation 11, 111 line through distortion of the upper delimitation of the light image 11a, 11b, 111a, 111b corner region of the upper distortion of the light image 12, 112 line through distortion of the lower delimitation of the light image 12a, 12b, 112a, 112b corner region of the lower distortion of the light image h.sub.7, h.sub.7b vertical distance of the horizontal row from the horizontal axis x