This nonprovisional application claims priority under 35 U.S.C. § 119(a) on German Patent Application No. DE 103 09 434.2 filed in Germany on Mar. 5, 2003, which is herein incorporated by reference.
1. Field of the Invention
The present invention relates to a headlight for vehicles with a projection module including a bowl-shaped reflector, an illumination unit that is provided for the bowl-shaped reflector, a lens, and a shutter arranged between the lens and the reflector, whereby the shutter forms a light-dark-border of a light bundle of the headlight, the lens has a convex front side that faces away from the bowl-shaped reflector, an optical element on the convex front side of the lens is arranged in a lower middle margin area, and light beams emerging from the optical element are directed to an area above the light-dark border of the light bundle of the headlight.
2. Description of the Background Art
From DE-U-90 00 395 a headlight for vehicles is known, whereby a projection module for a fog light is arranged in a housing behind a closure pane. To manipulate the light distribution of the light bundle, the closure pane is provided with a cylinder optic, and the lens, in its middle lower margin area on a convex front side, is provided with an optical element, which has a cylinder optic extending in a horizontal direction. The cylinder optic borders, in a downward direction, a convex segment of the front of the lens that is receded in the direction of the optical axis to the reflector. The cylinder optic of the lens deflects a part of the light in a certain angle area upwards. Thus, the light values above the light-dark-border increase so that the legal rules for fog lights are followed. Because the horizontal cylinder optic of the lens has a relatively great distance from the lower margin of the lens, the driver's vision field is inhomogeneously (non-uniformly) illuminated. Furthermore, the width of the band of light created by the horizontal cylinder optic above the light-dark-border is variable in height only by an arrangement of the horizontal cylinder optic. The higher that the cylinder optic is arranged, the more distracting the resulting inhomogeneous light distribution is.
It is therefore an object of the present invention to provide a headlight for vehicles so that an optical element of a lens creates neither an inhomogeneous light distribution for a shuttered light bundle nor an irritating elevation on a convex front side of the lens. According to the invention, this is accomplished in that continuously or in sections staggered in relation to each other, the surface of the optical element is concave-shaped in vertical second planar sections, to which the optical axis of the projection module extends perpendicular, and is convex-shaped in vertical first planar sections extending parallel to the optical axis.
With a lens with an original full-surface convex front side, the light beams emerging from the optical element would illuminate a very limited area in front of the vehicle, which for the driver would be hidden by the body of the vehicle. With segments of the surface of the lens staggered in relation to each other, e.g., the segments being arranged stepwise to one another, the light beams would illuminate a larger area, thereby providing an increased illumination area for the driver.
Additionally, it is beneficial if the concave-shaped, that is, the convex-shaped surface of the optical element extends all the way to the convex front side of the lens and is bordered towards the convex front side of the lens by an edge, and the surface of the lens, which is convex-shaped in the first planar sections, is bordered by a bent first line section, which in its course has a respective bent third line section, which is located on the original lens on the original full-surface convex front side in a middle vertical planar section in the lower margin area. This provides a light distribution above the light-dark-border with precise borders towards the top and to the sides, and no transitional surfaces between the convex front side of the lens and the optical element are needed.
A particular advantage of the invention is that the bent third line section on the original full-surface convex front side of the lens and the bent first line section of the optical element have a mutual center of rotation above the optical element, whereby the first line section of the optical element opposite the line section of the original full-surface convex front side of the lens is pivoted around the center of rotation towards the reflector by an angle. The angle determines the amount of the deflection of the upwardly-directed light beams.
The band of light created by the optical element and light figure of the light-dark-border intertwine one another, when there is an angle of between 5 degrees and 8 degrees preferably 6.5 degrees, between the bent third line section of the original full-surface convex front side of the lens and the bent first line section of the optical element.
In a preferred embodiment, the convex-shaped surface of the lens in the, horizontal planar sections is bordered by bent second line sections of a circular line. The larger the circle, the smaller the light deflection to the sides is.
A high-powered illumination unit, for example, a xenon lamp, requires a smaller optical element than a low-powered illumination unit like, for example, a halogen lamp. In both cases, the size of the light band created by the light beams is approximately the same.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limited of the present invention, and wherein:
A headlight for a vehicle has a projection module 1, which includes an elliptical reflector 2, an illumination unit 3 that is dedicated to the reflector 2, a lens 4, and a shutter 5 arranged between the lens 4 and the reflector 2. The shutter 5, together with a shutter edge, forms a light-dark-border 20 of an asymmetrical light bundle 19. In
The lens 4 features a planar back side 21 facing towards the reflector 2, and a convex front side 6. On the convex front side 6, in the lower middle margin area of lens 4, an optical element 7 is provided. The optical element 7 has a surface 10, which is symmetrical with a vertical middle planar section 25 of the lens 4, into which an optical axis 23 extends.
In all vertical first planar sections 12, which extend parallel to the optical axis 23, the surface 10 of the optical element 7 features convex first line sections 14, which are identical to a third line section 22, which is located on the convex front side 6 of the lens 4 and in the vertical middle planar section 25 of the lens 4 in the lower margin area of lens 4. The third line section 22 is pivoted by an angle α of, for example, 6.5 degrees towards the rear of the lens 4 and thus creates the first line section 14 of the surface 10 of the optical element 7 and extends in the vertical middle section of the lens 4.
In all vertical second planar sections 11 extending substantially parallel to the planar backside 21 of the lens 4, the surface 10 of the optical element 7 is concave-shaped and features second line sections 16 in all second planar sections 11. The second line sections 16 lie on a circular line 17, the radius 18 of which is smaller than that of lens 4. The surface 10 of the optical element 7 is bordered towards the convex front side 6 of the lens 4 by a sharp edge 13. Light beams 8, which are reflected by the reflector 8 and pass through the optical element 7, are directed towards an area 9, which, for at least most of its area, is arranged above the light-dark-border of the light bundle 19. In
Referring to
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations and not to be, regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.
Number | Date | Country | Kind |
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103 09 434 | Mar 2003 | DE | national |
Number | Name | Date | Kind |
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4180849 | Parkin | Dec 1979 | A |
4796171 | Lindae et al. | Jan 1989 | A |
5014173 | Lindae et al. | May 1991 | A |
5036438 | Nakata | Jul 1991 | A |
Number | Date | Country |
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3602262 | May 1987 | DE |
90 00 395.0 | Jun 1991 | DE |
4031352 | Apr 1992 | DE |
Number | Date | Country | |
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20040174714 A1 | Sep 2004 | US |