DE102014000474A1 - Vehicle headlights, in particular motor vehicle headlights - Google Patents

Abstract

The invention relates to a vehicle headlight (1), in particular motor vehicle headlight (1), with at least one light source, with a headlight lens (2) made of transparent plastic and with a diaphragm (14) arranged between the light source and the headlight lens (2), one edge (15) of the diaphragm (14) can be depicted as a light-dark boundary (25) by means of the headlight lens (2), and the headlight lens (2) is mechanically connected to the diaphragm (14) by means of at least one expansion element, in particular in this way is that the headlight lens (2) can be displaced with respect to the diaphragm (14) along the optical axis of the headlight lens (2) by means of the expansion element.

Description

The invention relates to a vehicle headlight, in particular a motor vehicle headlight, with at least one light source, with a headlight lens made of transparent plastic and solved with a arranged between the light source and the headlight lens aperture, wherein an edge of the aperture by means of the headlight lens as a light-dark boundary can be mapped is.

Such a vehicle headlight is from the DE 10 2007 037 204 A1 known.

It is an object of the invention to improve the lighting properties of an aforementioned vehicle headlight. In particular, the photometric properties with respect to the cut-off line should be improved. In particular, it is desirable to reduce or avoid chromatic fluctuations at the cut-off line.

The aforementioned object is achieved by a vehicle headlight, in particular a motor vehicle headlight, with at least one light source, with a headlight lens made of transparent plastic and arranged with an arranged between the light source and the headlight lens aperture, wherein an edge of the aperture by means of the headlight lens as a cut-off can be imaged, wherein the headlight lens has a surface structure and / or in its interior a light scattering structure, and wherein the headlight lens by means of at least one (thermal) expansion element, in particular such, mechanically connected to the diaphragm, that the headlight lens by means of (thermal) Expansion element relative to the diaphragm along the optical axis of the headlight lens is displaceable. In particular, it is provided that the distance between the diaphragm and the light source or between the diaphragm and a reflector associated with the light source is (essentially) temperature-independent.

A vehicle headlight according to the invention is in particular a projection headlight or a PES headlight. Details of these headlamps can be, for example, the Pages 743 to 745 of the book "Bosch, Kraftfahrtechnisches Taschenbuch", 23rd Edition, Vieweg, 1999, ISBN 3-528-03876-4 be removed. A vehicle headlight in the sense of the invention can be (also) a projection module for a projection headlight or a PES headlight.

A (thermal) expansion element according to the invention is in particular an element whose length and / or curvature is temperature-dependent. A (thermal) expansion element according to the invention is in particular a bimetal strip or an element acting as a bimetal strip. A (thermal) expansion element according to the invention is designed in particular as a bimetallic strip or as an element acting as a bimetallic strip. A (thermal) expansion element according to the invention in particular comprises a bimetallic strip or an element acting as a bimetallic strip. A (thermal) expansion element according to the invention is in particular arranged and / or formed such that the distance between the diaphragm and the headlight lens decreases when the temperature of the (thermal) expansion element decreases. A (thermal) expansion element according to the invention is in particular arranged and / or formed such that the distance between the diaphragm and the headlight lens increases when the temperature of the (thermal) expansion element increases.

Transparent plastic can be PMMA. Transparent plastic is in the context of the invention, in particular transparent thermoplastic. Transparent plastic is in the context of the invention, in particular polycarbonate, in particular LED 2643, or a thermoplastic resin such. A polycarbonate resin, a polyacrylic resin or a modified polyolefin resin. Examples of suitable thermoplastics or thermoplastic resins, in particular the DE 699 23 847 T2 and the DE 10 2007 037 204 A1 be removed. So revealed the DE 699 23 847 T2 as the polycarbonate resin, the suitable use of aromatic polycarbonate resin obtained by reacting a diphenol and a carbonate precursor.

In a further advantageous embodiment of the invention, the (thermal) expansion element or the longitudinal direction (direction of the longest extent of the (thermal) expansion element) of the (thermal) expansion element extends tangentially to a (in particular orthogonal to the optical axis of the headlight lens aligned and / or centric) Circle around the optical axis of the headlight lens.

In a further advantageous embodiment of the invention, the headlight lens by means of the (thermal) expansion element relative to the diaphragm (along the optical axis of the headlight lens) by at least 5 microns per ° C temperature change, in particular by at least 10 microns per ° C, temperature change displaced. In a further advantageous embodiment of the invention, the headlight lens by means of the (thermal) expansion element relative to the diaphragm (along the optical axis of the headlight lens) by not more than 20 microns per ° C temperature change, in particular by not more than 15 microns per ° C temperature change, displaced ,

In a further advantageous embodiment of the invention, the vehicle headlight comprises at least one guide element along which the headlight lens relative to the diaphragm in the direction of or along the optical axis of the headlight lens is displaceable. A guide element according to the invention is designed in particular as a pin. Such a pin extends in particular parallel to the optical axis of the headlight lens.

In a further advantageous embodiment of the invention, the vehicle headlight comprises a support for, in particular such, mechanical recording of the headlight lens, that the headlight lens is displaceable together with the Täger means of the (thermal) expansion element relative to the diaphragm along the optical axis of the headlight lens. In a further advantageous embodiment of the invention, the carrier comprises at least one bore or a hole or a notch, notch or groove for receiving the guide element. A carrier according to the invention is in particular designed or configured in a ring shape. In a further advantageous embodiment of the invention, the carrier comprises a groove for receiving the (thermal) expansion element. It is provided in particular that the groove extends tangentially to a (in particular orthogonal to the optical axis of the headlight lens aligned) circle around the optical axis of the headlight lens. It is provided in particular that the (thermal) expansion element or its one end is mounted slidably or movably within the groove, or that the (thermal) expansion element or one end in (longitudinal) of the groove can slide.

The headlight lens may be a lens made by means of blank presses and / or injection presses. In the context of the invention, blank presses are to be understood in particular to press an optically active surface in such a way that a subsequent reworking of the contour of this optically effective surface can be dispensed with or is omitted or not provided for.

In one embodiment, it is provided in particular that the carrier is part of the headlight lens. It may be provided that the carrier and the headlight lens are manufactured in one piece or are pressed or injection-molded together. It can be provided in particular that the carrier is part of an edge of the headlight lens or forms an edge of the headlight lens.

In a further advantageous embodiment of the invention, the light source comprises a lamp, in particular a gas discharge lamp or an incandescent lamp, or is designed as a lamp, in particular a gas discharge lamp or an incandescent lamp. The light source can be z. B. be a halogen lamp or a xenon lamp. Suitable embodiments for the first light source may, for. B. the Pages 739-753 of the book "Bosch, Kraftfahrtechnisches Taschenbuch", 23rd Edition, Vieweg, 1999, ISBN 3-528-03876-4 be removed. But it can also be provided that the light source is an LED or an array of LEDs. A light source can also be a laser. A suitable laser is in ISAL 2011 Proceedings, page 271ff disclosed.

The aforementioned object is also achieved by a motor vehicle with an aforementioned vehicle headlight, wherein it is provided in particular that the cut-off line can be imaged on a roadway on which the motor vehicle can be arranged.

Motor vehicle in the sense of the invention is in particular a land vehicle which can be used individually in road traffic. Motor vehicles according to the invention are not limited in particular to land vehicles with internal combustion engine.

Further advantages and details emerge from the following description of exemplary embodiments. Showing:

1 an exemplary embodiment of a motor vehicle,

2 a schematic representation of a projection module of an exemplary vehicle headlamp,

3 an exemplary luminous distribution of the vehicle headlight according to the projection module 2 .

4 a cross section through an embodiment of a headlight lens for a projection module according to 2 .

5 a section of the cross section according to 4 .

6 the projection module according to 2 in a perspective side view,

7 an optical carrier of the projection module according to 6 .

8th a guide ring of the projection module according to 6 and

9 a partial side view of the projection module according to 6 ,

1 shows a motor vehicle 100 with a vehicle headlight 101 who is in 2 schematically represented projection module 1 with a light source 10 for generating light, a reflector 12 for reflecting by means of the light source 10 producible light and a diaphragm 14 includes. The projection module 1 also includes a headlight lens 2 for changing the beam direction of by means of the light source 10 producible light and in particular for imaging an in 2 with reference number 15 designated edge of the aperture 14 as a light-dark border 25 as exemplified in 3 in a graphic 20 and in a photograph 21 is shown. Important photometric guide values are the gradient G of the cut-off line 25 and the glare value HV of the vehicle headlight 1 into the headlight lens 2 is installed.

The headlight lens 2 includes a lens body 3 made of a transparent plastic, which is one of the light source 10 facing substantially planar optically effective surface 5 and one of the light source 10 opposite convex curved optically effective surface 4 includes. The headlight lens 2 also includes a border 6 by means of which the headlight lens 2 in the projection module 1 is fastened.

4 shows a cross section through an embodiment of the headlight lens 2 for the projection module 1 according to 2 , 5 shows an in 4 by a dash-dotted circle marked section of the headlight lens 2 , The essentially planar optically effective surface 5 protrudes in the form of a step 60 in the direction of the optical axis 30 the headlight lens 2 over the lens edge 6 or over the light source 10 facing surface 61 of the lens edge 6 addition, where the height h of the stage 60 not more than 1 mm, advantageously not more than 0.5 mm. The nominal value of the height h of the stage 60 is advantageously 0.2 mm.

The thickness r of the lens edge 6 is at least 2 mm but not more than 5 mm. The diameter DL of the headlight lens 2 is at least 40 mm but not more than 100 mm. The diameter DB of the substantially planar optically effective surface 5 is equal to the diameter DA of the convexly curved optically effective surface 4 , In an advantageous embodiment, the diameter DB of the substantially planar optically effective surface 5 not more than 110% of the diameter DA of the convexly curved optically effective surface 4 , In addition, the diameter DB of the substantially planar optically effective surface 5 advantageously at least 90% of the diameter DA of the convexly curved optically active surface 4 , The diameter DL of the headlight lens 2 is advantageously about 5 mm larger than the diameter DB of the substantially planar optically effective surface 5 or as the diameter DA of the convex curved optically active surface 4 ,

The headlight lens 2 Optionally points inside the transparent body 3 a light-scattering structure 35 on. The light scattering structure 35 is advantageously a structure generated by means of a laser. It advantageously comprises a number of punctiform defects, in particular to one to the optical axis 30 aligned orthogonal plane. It can be provided that the light scattering structure 35 is annular or comprises annular regions or that the punctiform defects are arranged in rings. It can be provided that the punctiform defects, in particular within the selected structure, are randomly distributed.

Suitable methods for producing the light-scattering structure 35 inside the transparent body 3 can for example the SU 1838163 A3 , of the SU 1818307 A1 , the Article, "Optical applications of laser-induced gratings in Eudoped glasses", Edward G. Behrens, Richard C. Powell, Douglas H. Blackburn, April 10, 1990 / Vol. 29, no. 11 / APPLIED OPTICS , the Article, "Relationship between laser-induced gratings and vibrational properties of Eu-doped glasses", Frederic M. Durville, Edward G. Behrens, Richard C. Powell, 35, 4109, 1987 . The American Physical Society, the article, "Laser-induced refractive-index gratings in Eu-doped glasses," Frederic M. Durville, Edward G. Behrens, Richard C. Powell, 34, 4213, 1986 . The American Physical Society, the article, "Internal Processing of Glass with Nd: YAG Laser," Klaus Dickmann, Elena Dik, Laser Magazine as well as in the US Pat. No. 6,992,804 B2 cited prior art.

In an alternative embodiment of the headlight lens 2 can be provided that this (in place of the edge 6 ) one (to the rear or in the direction of the light source 10 facing side) protruding edge includes, as he z. B. in the WO 03/087893 A1 , of the DE 203 20 546 U1 , of the EP 1 495 347 A1 , of the DE 102 16 706 A1 , of the EP 1645545 and the DE 10 2004 048 500 A1 is disclosed.

It can be provided that the headlight lens 2 Having surface structures, in particular as in the 6 to 10 of the DE 10 2007 037 204 A1 are disclosed.

6 shows the projection module 1 in a perspective side view. Here, reference numeral designates 40 one in 7 illustrated optics carrier and reference numerals 42 one in 8th illustrated guide ring. The guide ring 42 is an embodiment of a carrier in the sense of the claims. The guide ring 42 and the headlight lens 2 are exemplary one piece made of transparent plastic. The optics carrier 40 is mechanically by means of a bimetallic strip 41 with the guide ring 42 connected. In addition, the slide has 40 guide pins 401 . 402 and 403 on that in holes 421 . 422 . 423 with sliding guide of the guide ring 42 are guided.

The optics carrier 40 also has a groove 405 on, in which the one end of the bimetallic strip 41 is locked. The other end of the bimetallic strip 41 is sliding in a groove 425 of the guide ring 42 stored. The guide pins 401 . 402 . 403 are exemplary embodiments of guide elements in the sense of the claims. In conjunction with the guide pins 401 . 402 . 403 or the holes 421 . 422 . 423 shifts the bimetallic strip 41 the guide ring 42 along with the headlight lens 2 depending on the temperature along the optical axis 30 the headlight lens 2 , In this case, the distance between the guide ring 42 and the optics carrier 40 and thus the headlight lens 2 and the aperture 14 reduced by 0.8 mm when the temperature of the bimetallic strip 41 decreased from 20 ° to -40 ° C. The distance between the guide ring 42 and the optics carrier 40 and thus the headlight lens 2 and the aperture 14 is increased by 0.8 mm when the temperature of the bimetallic strip 41 increased from 20 ° to 90 ° C. A suitable bimetallic strip comprises the material pairing FeNi20Mn6 and FeNi6 and is 1 mm thick, 5 mm wide and 20 mm long.

It has been shown that it is possible by means of the invention to (almost) completely curb or prevent chromatic fluctuations in the projection headlight or projection modules with plastic lenses, even chromatic fluctuations between blue and red.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007037204 A1 [0002, 0007, 0034]
• DE 69923847 T2 [0007, 0007]
• SU 1838163 [0032]
• SU 1818307 A1 [0032]
• US 6992804 B2 [0032]
• WO 03/087893 A1 [0033]
• DE 20320546 U1 [0033]
• EP 1495347 A1 [0033]
• DE 10216706 A1 [0033]
• EP 1645545 [0033]
• DE 102004048500 A1 [0033]

Cited non-patent literature

• Pages 743 to 745 of the book "Bosch, Kraftfahrtechnisches Taschenbuch", 23rd Edition, Vieweg, 1999, ISBN 3-528-03876-4 [0005]
• Pages 739-753 of the book "Bosch, Kraftfahrtechnisches Taschenbuch", 23rd Edition, Vieweg, 1999, ISBN 3-528-03876-4 [0014]
• ISAL 2011 Proceedings, page 271ff [0014]
• Article, "Optical applications of laser-induced gratings in Eudoped glasses", Edward G. Behrens, Richard C. Powell, Douglas H. Blackburn, April 10, 1990 / Vol. 29, no. 11 / APPLIED OPTICS [0032]
• Article, "Relationship between laser-induced gratings and vibrational properties of Eu-doped glasses", Frederic M. Durville, Edward G. Behrens, Richard C. Powell, 35, 4109, 1987 [0032]
• The American Physical Society, the article, "Laser-induced refractive-index gratings in Eu-doped glasses," Frederic M. Durville, Edward G. Behrens, Richard C. Powell, 34, 4213, 1986. [0032]
• The American Physical Society, the article, "Internal Processing of Glass with Nd: YAG Laser", Klaus Dickmann, Elena Dik, Laser Magazine [0032]

Claims (9)

Vehicle headlights ( 1 ), in particular motor vehicle headlights ( 1 ), with at least one light source, with a headlight lens ( 2 ) made of transparent plastic and with one between the light source and the headlight lens ( 2 ) arranged aperture ( 14 ), one edge ( 15 ) the aperture ( 14 ) by means of the headlight lens ( 2 ) as a cut-off line ( 25 ) is imaged, characterized in that the headlight lens ( 2 ) by means of at least one expansion element, in particular such, mechanically with the diaphragm ( 14 ), that the headlight lens ( 2 ) by means of the expansion element with respect to the diaphragm ( 14 ) along the optical axis of the headlight lens ( 2 ) is displaceable. Vehicle headlights ( 1 ) according to claim 1, characterized in that the (thermal) expansion element comprises a bimetallic strip. Vehicle headlights ( 1 ) according to claim 1 or 2, characterized in that the headlight lens ( 2 ) by means of the expansion element with respect to the diaphragm ( 14 ) by at least 5 microns per ° C temperature change, in particular by at least 10 microns per ° C, temperature change is displaced. Vehicle headlights ( 1 ) according to claim 1, 2 or 3, characterized in that the headlight lens ( 2 ) by means of the expansion element with respect to the diaphragm ( 14 ) is displaced by not more than 20 microns per ° C temperature change, in particular by not more than 15 microns per ° C temperature change. Vehicle headlights ( 1 ) according to one of the preceding claims, characterized in that it comprises at least one guide element along which the headlight lens ( 2 ) opposite the diaphragm ( 14 ) along the optical axis of the headlight lens ( 2 ) is displaceable. Vehicle headlights ( 1 ) according to one of the preceding claims, characterized in that it comprises a support for, in particular, a mechanical recording of the headlight lens ( 2 ) includes that the headlight lens ( 2 ) together with the Täger means of the expansion element opposite the diaphragm ( 14 ) along the optical axis of the headlight lens ( 2 ) is displaceable. Vehicle headlights ( 1 ) according to claim 6, characterized in that the carrier comprises at least one bore or a hole for receiving the guide element. Vehicle headlights ( 1 ) according to claim 6 or 7, characterized in that the carrier comprises a groove for receiving the expansion element. Motor vehicle ( 100 ), characterized in that it has a vehicle headlamp ( 1 ) according to one of the preceding claims, wherein it is provided in particular that the cut-off line ( 25 ) on a roadway on which the motor vehicle ( 100 ) can be arranged, is mappable.

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